1. | Popławski B., Mikułowski G., Mróz A., Jankowski Ł., Decentralized semi-active damping of free structural vibrations by means of structural nodes with an on/off ability to transmit moments, MECHANICAL SYSTEMS AND SIGNAL PROCESSING, ISSN: 0888-3270, DOI: 10.1016/j.ymssp.2017.08.012, Vol.100, pp.926-939, 2018Popławski B., Mikułowski G., Mróz A., Jankowski Ł., Decentralized semi-active damping of free structural vibrations by means of structural nodes with an on/off ability to transmit moments, MECHANICAL SYSTEMS AND SIGNAL PROCESSING, ISSN: 0888-3270, DOI: 10.1016/j.ymssp.2017.08.012, Vol.100, pp.926-939, 2018Abstract: This paper proposes, tests numerically and verifies experimentally a decentralized control algorithm with local feedback for semi-active mitigation of free vibrations in frame structures. The algorithm aims at transferring the vibration energy of low-order, lightly-damped structural modes into high-frequency modes of vibration, where it is quickly damped by natural mechanisms of material damping. Such an approach to mitigation of vibrations, known as the prestress-accumulation release (PAR) strategy, has been earlier applied only in global control schemes to the fundamental vibration mode of a cantilever beam. In contrast, the decentralization and local feedback allows the approach proposed here to be applied to more complex frame structures and vibration patterns, where the global control ceases to be intuitively obvious. The actuators (truss–frame nodes with controllable ability to transmit moments) are essentially unblockable hinges that become unblocked only for very short time periods in order to trigger local modal transfer of energy. The paper proposes a computationally simple model of the controllable nodes, specifies the control performance measure, yields basic characteristics of the optimum control, proposes the control algorithm and then tests it in numerical and experimental examples. Keywords: Damping of vibrations, Smart structures, Semi-active control, Decentralized control, Truss-frame nodes | | (45p.) |
2. | Jeznach O.^{♦}, Gajc M., Korzeb K., Kłos A., Orliński K., Stępień R., Krok-Borkowicz M., Rumian Ł., Pietryga K., Reczyńska K., Pamuła E., Pawlak D.A., New calcium-free Na2O-Al2O3-P2O5 bioactive glasses with potential applications in bone tissue engineering, Journal of the American Ceramic Society, ISSN: 0002-7820, DOI: 10.1111/jace.15216, Vol.101, No.2, pp.602-611, 2018Jeznach O.^{♦}, Gajc M., Korzeb K., Kłos A., Orliński K., Stępień R., Krok-Borkowicz M., Rumian Ł., Pietryga K., Reczyńska K., Pamuła E., Pawlak D.A., New calcium-free Na2O-Al2O3-P2O5 bioactive glasses with potential applications in bone tissue engineering, Journal of the American Ceramic Society, ISSN: 0002-7820, DOI: 10.1111/jace.15216, Vol.101, No.2, pp.602-611, 2018Abstract: Sodium aluminophosphate glasses were evaluated for their bone repair ability. The glasses belonging to the system 45Na2O–xAl2O3-(55-x)P2O5, with x = (3, 5, 7, 10 mol%) were prepared by a melt-quenching method. We assessed the effect of Al2O3 content on the properties of Na2O–Al2O3–P2O5 (NAP) glasses, which were characterized by density measurements, DSC analyses, solubility, bioactivity in simulated body fluid and cytocompatibility with MG-63 cells. To the best of our knowledge, this is the first investigation of calcium-free Na2O–Al2O3–P2O5 system glasses as bioactive materials for bone tissue engineering. Keywords: alumina, bioactive glass, bone tissue engineering, calcium-free bioactive glass, phosphate glass, sodium aluminophosphate glass | | (45p.) |
3. | Kursa M., Kowalczyk-Gajewska K., Lewandowski M.J., Petryk H., Elastic-plastic properties of metal matrix composites: Validation of mean-field approaches, EUROPEAN JOURNAL OF MECHANICS A-SOLIDS, ISSN: 0997-7538, DOI: 10.1016/j.euromechsol.2017.11.001, Vol.68, pp.53-66, 2018Kursa M., Kowalczyk-Gajewska K., Lewandowski M.J., Petryk H., Elastic-plastic properties of metal matrix composites: Validation of mean-field approaches, EUROPEAN JOURNAL OF MECHANICS A-SOLIDS, ISSN: 0997-7538, DOI: 10.1016/j.euromechsol.2017.11.001, Vol.68, pp.53-66, 2018Abstract: Several micromechanical and numerical approaches to estimating the effective properties of heterogeneous media are analyzed. First, micromechanical mean-field estimates of elastic moduli for selected metal matrix composite systems are compared with the results of finite element calculations performed for two simplified unit cells: spherical and cylindrical. Advantages and deficiencies of such numerical verification of analytical homogenization schemes are indicated. Next, predictions of both approaches are compared with available experimental data for two composite systems for tension and compression tests in the elastic-plastic regime using tangent and secant linearization procedures. In the examined range of strain and ceramic volume content, both the Mori-Tanaka averaging scheme and the generalized self-consistent scheme lead to reliable predictions when combined with the tangent linearization, while the use of secant moduli results in a too stiff response. It is also found that the mean-field predictions for a small ceramic volume content are very close to the results obtained from the finite-element analysis of a spherical unit cell. Keywords: Metal-matrix composites, Effective properties, Analytical estimates, Numerical homogenization, Nonlinear analysis | | (35p.) |
4. | Kiełczyński P., Direct Sturm–Liouville problem for surface Love waves propagating in layered viscoelastic waveguides, Applied Mathematical Modelling, ISSN: 0307-904X, DOI: 10.1016/j.apm.2017.09.013, Vol.53, pp.419-432, 2018Kiełczyński P., Direct Sturm–Liouville problem for surface Love waves propagating in layered viscoelastic waveguides, Applied Mathematical Modelling, ISSN: 0307-904X, DOI: 10.1016/j.apm.2017.09.013, Vol.53, pp.419-432, 2018Abstract: This paper presents theoretical model for shear-horizontal (SH) surface acoustic waves of the Love type propagating in lossy waveguides consisting of a lossy viscoelastic layer de- posited on a lossless elastic half-space. To this end, a direct Sturm–Liouville problem that describes Love waves propagation in the considered viscoelastic waveguides was formu- lated and solved, what constitutes a novel approach to the state-of-the-art. To facilitate the solution of the complex dispersion equation, the Author employed an original ap- proach that relies on the separation of its real and imaginary part. By separating the real and imaginary parts of the resulting complex dispersion equation for a complex wave vec- tor k = k 0 + j αof the Love wave, a system of two real nonlinear transcendental algebraic equations for k 0 and αhas been derived. The resulting set of two algebraic transcenden- tal equations was then solved numerically. Phase velocity v p and coefficient of attenuation αwere calculated as a function of the wave frequency f , thickness of the surface layer h and its viscosity η44 . Dispersion curves for Love waves propagating in lossy waveguides, with a lossy surface layer deposited on a lossless substrate, were compared to those cor- responding to Love surface waves propagating in lossless waveguides, i.e., with a lossless surface layer deposited on a lossless substrate. The results obtained in this paper are orig- inal and to some extent unexpected. Namely, it was found that: 1) the phase velocity v p of Love surface waves increases as a function of viscosity η44 of the lossy surface layer, and 2) the coefficient of attenuation αhas a maximum as a function of thickness h of the lossy surface layer. The results obtained in this paper are novel and can be applied in geo- physics, seismology and in the optimal design and development of viscosity sensors, bio and chemosensors. Keywords: Sturm–Liouville problem; Complex dispersion equation; Surface acoustic love waves; Eigenvalues; Elastic waves; Viscoelastic waveguides | | (35p.) |
5. | Mróz Z., Kucharski S., Páczelt I., Anisotropic friction and wear rules with account for contact state evolution, WEAR, ISSN: 0043-1648, DOI: 10.1016/j.wear.2017.11.004, Vol.396-397, pp.1-11, 2018Mróz Z., Kucharski S., Páczelt I., Anisotropic friction and wear rules with account for contact state evolution, WEAR, ISSN: 0043-1648, DOI: 10.1016/j.wear.2017.11.004, Vol.396-397, pp.1-11, 2018Abstract: The present study is related to analysis of coupled friction and wear process in sliding along the rough surface with an anisotropic asperity pattern characterized by single or mutually orthogonal striations. Due to wear process the initial anisotropic response evolves with the variation of asperity distribution, tending to a steadystate pattern. The orthotropic friction sliding model and the related wear rule are analytically formulated assuming evolution of contact anisotropy to its steady state. The orthotropic frictional sliding model and the related wear rule are analytically formulated assuming evolution of contact anisotropy to its steady state. The experimental study is next presented for orthotropic asperity patterns induced on steel plate surface. The transient and steady states are characterized and the respective evolution parameters calibrated. The numerical finite element wear analysis aimed at validation of model-predictions and wear parameter calibration is presented at the end of paper Keywords: Anisotropic contact, Friction sliding and wear rules, Evolution of contact anisotropy, Experimental study, Numerical wear analysis | | (35p.) |
6. | Nowak M., Maj M., Determination of coupled mechanical and thermal fields using 2D digital image correlation and infrared thermography: Numerical procedures and results, ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING, ISSN: 1644-9665, DOI: 10.1016/j.acme.2017.10.005, Vol.18, pp.630-644, 2018Nowak M., Maj M., Determination of coupled mechanical and thermal fields using 2D digital image correlation and infrared thermography: Numerical procedures and results, ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING, ISSN: 1644-9665, DOI: 10.1016/j.acme.2017.10.005, Vol.18, pp.630-644, 2018Abstract: The objective of the work is to develop numerical method for determining coupled thermo-mechanical fields based on experimental data obtained from two cameras working in the visible and infrared mode. The sequence of images recorded by the first camera is used to determine the displacement field on the sample surface using the 2D digital image correlation (DIC) method. The resulting field from DIC analysis in a form of a set of discrete points with the corresponding in-plane displacement vector is used as the input for the next step of analysis, where the coupled temperature field is computed. This paper provides a detailed description of the numerical procedures, that allow, to obtain coupled thermal and mechanical fields together with the specification of experimental data needed for calculations. The presented approach was tested on an experimental data obtained during uniaxial tension of the multicrystalline aluminum. The developed numerical routine has been implemented in dedicated software, which can be used for the testing of materials on both a macro and micro scales Keywords: Digital image correlation (DIC), Infrared thermography (IRT), Coupled thermo-mechanical fields, Aluminum multicrysta | | (30p.) |
7. | Jurczak G., Dłużewski P., Finite element modelling of threading dislocation effect on polar GaN/AlN quantum dot, PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES, ISSN: 1386-9477, DOI: 10.1016/j.physe.2017.08.018, Vol.95, pp.11-15, 2018Jurczak G., Dłużewski P., Finite element modelling of threading dislocation effect on polar GaN/AlN quantum dot, PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES, ISSN: 1386-9477, DOI: 10.1016/j.physe.2017.08.018, Vol.95, pp.11-15, 2018Abstract: In this paper the effect of adjacent threading dislocation at the edge of the GaN/AlN quantum dot is analysed by use of the finite element analysis. Elastic as well electric effects related to dislocation core are taken into account. Two types of threading dislocations: edge- and screw-type, common for III-nitride epitaxial layers, are considered. Also, three different QD geometries are considered to estimate the impact of the threading dislocation on the quantum heterostructure. It is demonstrated that the local elastic and electric fields around dislocation affect local piezoelectric fields built-in the quantum dot. Local lattice deformation near the dislocation core reduce residual strains in the quantum dot. It is prominent in the case of edge-type dislocation. The presence of an electric charge along dislocation line provides significant shift of the total potential towards the negative values. However, estimated difference in band-to-band transition energy for edge- and screw-type dislocations are rather small, what suggest low sensitivity to the charge density along dislocation line. Unexpectedly, local strain field around the edge-type dislocation, slightly compensate the negative affect of the electrostatic potential. Keywords: Quantum dot, Threading dislocation, Piezoelectricity, Finite element modelling | | (20p.) |
8. | Ekiel-Jeżewska M.L., Wajnryb E., Motion of a particle with stick-slip boundary conditions towards a flat interface: hard wall or free surface, Physicochemical Problems of Mineral Processing, ISSN: 1643-1049, DOI: 10.5277/ppmp1849, Vol.54, No.1, pp.203-209, 2018Ekiel-Jeżewska M.L., Wajnryb E., Motion of a particle with stick-slip boundary conditions towards a flat interface: hard wall or free surface, Physicochemical Problems of Mineral Processing, ISSN: 1643-1049, DOI: 10.5277/ppmp1849, Vol.54, No.1, pp.203-209, 2018Abstract: Motion of a particle with stick-slip boundary conditions towards a hard wall or free surface is investigated in the range of Reynolds numbers much smaller than unity, based on the multipole expansion of the Stokes equations. The slip parameter can be interpreted as a measure of a solid particle roughness or as the effect of a surfactant on the motion of a small spherical non-deformable bubble. The particle friction coefficient is evaluated as a function of the distance from its center to the wall, based on the inverse power series expansion, and the results are used to derive explicit lubrication expressions for the friction coefficient, in a wide range of the slip parameters. It is pointed out that for a very small thickness of the fluid film, the lubrication expressions are more accurate than the series expansion. The drainage time is calculated and analyzed, and estimated in terms of explicit lubrication expressions. Keywords: particle, boundary conditions, hard wall, free surface | | (20p.) |
9. | Wiśniewski K., Turska E., Recent improvements to nine-node shell element MITC9 with drilling rotations, SSTA 2017, Shell Structures: Theory and Applications, 2017-10-11/10-13, Gdańsk (PL), Vol.4, pp.399-402, 2018Wiśniewski K., Turska E., Recent improvements to nine-node shell element MITC9 with drilling rotations, SSTA 2017, Shell Structures: Theory and Applications, 2017-10-11/10-13, Gdańsk (PL), Vol.4, pp.399-402, 2018Abstract: The paper describes our improved 9-node quadrilateral shell element MITC9i, which is derived for the Reissner-Mindlin shell kinematics, the extended potential energy functional and Green strain.
1. The MITCi technique is used to avoid locking and it is based on the improved transformations proposed in (Wisniewski & Panasz 2013) for a membrane element. Here, these transformations are extended to bending/twisting and transverse shear shell strains.
2. To reduce the shape distortion effects, the so-called corrected shape functions (CSF) of (Celia & Gray 1984) are used instead of the isoparametric ones, and we propose the method of computation the shift parameters for non-flat shell elements.
3. The drilling rotations are included via the drilling Rotation Constraint and the penalty method. This rotation is used in the multiplicative/additive update scheme valid for large (unrestricted) rotations.
The effect of the MITC9i technique and the CSF is that all three patch tests are passed, also for shifted side nodes along the straight edges and for arbitrary shifts of an interior node. The MITC9i shell element was subjected to a range of linear and non-linear numerical tests described in (Wisniewski & Turska 2017); here we provide additional examples illustrating its accurate and robust behavior. Keywords: 9-node shell element MITC9,two-level approximation of strains, corrected shape functions, node shift parameters, drilling rotations | |
10. | Marszałek A., Burczyński T., Ordered Fuzzy GARCH Model for Volatility Forecasting, Includes the proceedings of the 10th Conference of the European Society for Fuzzy Logic and Technology (EUSFLAT-2017), 2017-09-11/09-15, Warszawa (PL), No.XI, pp.480-492, 2018Marszałek A., Burczyński T., Ordered Fuzzy GARCH Model for Volatility Forecasting, Includes the proceedings of the 10th Conference of the European Society for Fuzzy Logic and Technology (EUSFLAT-2017), 2017-09-11/09-15, Warszawa (PL), No.XI, pp.480-492, 2018Abstract: A volatility forecasting comparative study between the most popular original GARCH model and the same model defined based on concepts of Ordered Fuzzy Numbers and Ordered Fuzzy Candlsticks is presented. These approaches offer a suitable tool to handle both imprecision of measurements and uncertainty associated with financial data. Therefore, they are particularly useful for volatility forecasting, since the volatility is unobservable and a proxy for it is used (realised volatility). In presented study, based on intra-daily data of theWarsaw Stock Exchange Top 20 Index (WIG 20), one showed that based on the adjusted-R squared and several prediction measurements, the fuzzy approach does perform better than the original GARCH model and forecasts more precisely in both the in-sample and out-of-sample predictions Keywords: Volatility forecasting, Realized volatility, Ordered fuzzy number, Kosinski’s fuzzy number, Ordered fuzzy candlestick, Ordered fuzzy GARCH model, Financial high-frequency data | |
11. | Kochańczyk M., Hlavacek W.S., Lipniacki T., SPATKIN: a simulator for rule-based modeling of biomolecular site dynamics on surfaces , BIOINFORMATICS, ISSN: 1367-4803, DOI: 10.1093/bioinformatics/btx456, Vol.33, No.22, pp.3667-3669, 2017Kochańczyk M., Hlavacek W.S., Lipniacki T., SPATKIN: a simulator for rule-based modeling of biomolecular site dynamics on surfaces , BIOINFORMATICS, ISSN: 1367-4803, DOI: 10.1093/bioinformatics/btx456, Vol.33, No.22, pp.3667-3669, 2017Abstract: Rule-based modeling is a powerful approach for studying biomolecular site dynamics. Here, we present SPATKIN, a general-purpose simulator for rule-based modeling in two spatial dimensions. The simulation algorithm is a lattice-based method that tracks Brownian motion of individual molecules and the stochastic firing of rule-defined reaction events. Because rules are used as event generators, the algorithm is network-free, meaning that it does not require to generate the complete reaction network implied by rules prior to simulation. In a simulation, each molecule (or complex of molecules) is taken to occupy a single lattice site that cannot be shared with another molecule (or complex). SPATKIN is capable of simulating a wide array of membrane-associated processes, including adsorption, desorption and crowding. Models are specified using an extension of the BioNetGen language, which allows to account for spatial features of the simulated process. AVAILABILITY AND IMPLEMENTATION: The C ++ source code for SPATKIN is distributed freely under the terms of the GNU GPLv3 license. The source code can be compiled for execution on popular platforms (Windows, Mac and Linux). An installer for 64-bit Windows and a macOS app are available. The source code and precompiled binaries are available at the SPATKIN Web site (http://pmbm.ippt.pan.pl/software/spatkin). | | (45p.) |
12. | Fras T., Murzyn A., Pawłowski P., Defeat mechanisms provided by slotted add-on bainitic plates against small-calibre 7.62 mm x 51 AP projectiles., INTERNATIONAL JOURNAL OF IMPACT ENGINEERING, ISSN: 0734-743X, DOI: 10.1016/j.ijimpeng.2017.01.015, Vol.103, pp.241-253, 2017Fras T., Murzyn A., Pawłowski P., Defeat mechanisms provided by slotted add-on bainitic plates against small-calibre 7.62 mm x 51 AP projectiles., INTERNATIONAL JOURNAL OF IMPACT ENGINEERING, ISSN: 0734-743X, DOI: 10.1016/j.ijimpeng.2017.01.015, Vol.103, pp.241-253, 2017Abstract: Thin steel plates with an array of holes, i.e. perforated plates, are used as a passive add-on improving protective properties of armours against small-calibre projectiles. A number of holes in such plates increases the probability of asymmetrical contact between the plate and the projectile, due to which small-calibre projectiles may be destabilized or fragmented before they reach the main-armour. The aim of the study is to analyse the defeat mechanisms provided by 4-mm-thick slotted super-bainitic plates (Pavise™ SBS 600P) against hard-core 7.62mm P80 0.30 AP×51 (0.308 Win) projectiles. To show the dependence between the hit-point and projectile failure, moments when projectiles hit the pre-armour plate were recorded by an ultra-high speed camera and their behaviour after the impact was captured by the flash X-ray radiography. The obtained results complemented by the Lagrangian FEM analysis confirm that slotted steel plates have high protection effectiveness against small-calibre projectiles. Keywords: Light-weight ballistic protectionPerforated add-on armourSuper-bainitic steelArmour-piercing (AP) projectile | | (45p.) |
13. | Wiśniewski K., Turska E., Improved nine-node shell element MITC9i with reduced distortion sensitivity, COMPUTATIONAL MECHANICS, ISSN: 0178-7675, DOI: 10.1007/s00466-017-1510-4, pp.1-25, 2017Wiśniewski K., Turska E., Improved nine-node shell element MITC9i with reduced distortion sensitivity, COMPUTATIONAL MECHANICS, ISSN: 0178-7675, DOI: 10.1007/s00466-017-1510-4, pp.1-25, 2017Abstract: The 9-node quadrilateral shell element MITC9i is developed for the Reissner-Mindlin shell inematics, the extended potential energy and Green strain. The following features of its formulation ensure an improved behavior: 1. The MITC technique is used to avoid locking, and we propose improved ransformations for bending and transverse shear strains, which render that all patch tests are passed for the regular mesh, i.e. with straight element sides and middle positions of midside nodes and a central node. 2. To reduce shape distortion effects, the so-called corrected shape functions of Celia and Gray (Int J Numer Meth Eng 20:1447–1459, 1984) are extended to shells and used instead of the standard ones. In effect, all patch tests are passed additionally for shifts of the midside nodes along straight element sides and for arbitrary shifts of the central node. 3. Several extensions of the corrected shape functions are proposed to enable computations of non-flat shells. In particular, a criterion is put forward to determine the shift parameters associated with the central node for non-flat elements. Additionally, the method is presented to construct a parabolic side for a shifted midside node, which improves accuracy for symmetric curved edges. Drilling rotations are included by using the drilling Rotation Constraint equation, in a way consistent with the additive/multiplicative rotation update scheme for large rotations. We show that the corrected shape functions reduce the sensitivity of the solution to the regularization parameter γ of the penalty method for this constraint. The MITC9i shell element is subjected to a range of linear and non-linear tests to show passing the patch tests, the absence of locking, very good accuracy and insensitivity to node shifts. It favorably compares to several other tested 9-node elements. Keywords: 9-node shell element MITC9i, Two-level approximation of strains, Patch tests, Corrected shape functions, Node shift parameters, Coarse mesh accuracy, Drilling rotations | | (45p.) |
14. | Enayati M.S., Behzad T., Sajkiewicz P.Ł., Bagheri R., Ghasemi-Mobarakeh L., Pierini F., Theoretical and experimental study of the stiffness of electrospun composites of poly(vinyl alcohol), cellulose nanofibers, and nanohydroxy apatite, CELLULOSE, ISSN: 0969-0239, DOI: 10.1007/s10570-017-1601-6, pp.1-11, 2017Enayati M.S., Behzad T., Sajkiewicz P.Ł., Bagheri R., Ghasemi-Mobarakeh L., Pierini F., Theoretical and experimental study of the stiffness of electrospun composites of poly(vinyl alcohol), cellulose nanofibers, and nanohydroxy apatite, CELLULOSE, ISSN: 0969-0239, DOI: 10.1007/s10570-017-1601-6, pp.1-11, 2017Abstract: The present study aims to theoretically model and verify the mechanical behavior of electrospun fibers of poly(vinyl alcohol) (PVA) reinforced by nanohydroxy apatite (nHAp) and cellulose nanofibers (CNF), the three composites designated as PVA/nHAp, PVA/CNF, and PVA/nHAp/CNF. Tensile tests and AFM nanoindentation studies were used to measure tensile modulus of electrospun scaffolds and single fibers respectively. Halpin–Tsai and Ouali models were applied to predict the stiffness of electrospun mats. Theoretical analysis according to the Halpin–Tsai model showed that CNF have no preferred orientation in the electrospun fibers, particularly at higher filler content. Additionally, this model provided a better prediction than Ouali model, especially at lower filler content. Theoretical models based on the geometry of an unit cell in open-cell structure such as honeycomb, tetrakaidecahedron and cube models simulate electrospun scaffolds. Among the structural models for analysis of porous scaffolds, the honeycomb model showed the best prediction, tetrakaidecahedron model—a moderate one, and cube model was the worst. In general, it was proved by both experiment and theory that the porous structure of electrospun mat caused significant modulus reduction of nanocomposites. Keywords: Nanocomposites, Cellulose nanofibers, Electrospinning, Modulus | | (45p.) |
15. | Ryś M., Skoczeń B., Coupled constitutive model of damage affected two-phase continuum, MECHANICS OF MATERIALS, ISSN: 0167-6636, DOI: 10.1016/j.mechmat.2017.08.015, Vol.115, pp.1-15, 2017Ryś M., Skoczeń B., Coupled constitutive model of damage affected two-phase continuum, MECHANICS OF MATERIALS, ISSN: 0167-6636, DOI: 10.1016/j.mechmat.2017.08.015, Vol.115, pp.1-15, 2017Abstract: A broad class of metastable materials, including selected alloys (e.g. stainless steels) used for applications in radiation environment (particle accelerators), is characterized by simultaneous occurrence of the plastic strain driven phase transformation and evolution of nano/micro damage. Plastic flow in such materials is usually accompanied by dynamic evolution of microstructure, resulting from the strain induced fcc-bcc phase transformation. Two-phase continuum is composed of austenitic matrix (fcc) and martensitic inclusions (bcc), represented by type Eshelby ellipsoidal entities embedded in ductile matrix. The matrix remains entirely plastic, and contains micro-cracks and micro-voids representing ductile damage. On the other hand, the inclusions are characterized by much higher yield stress and their behavior is generally brittle. Thus, brittle damage develops in the inclusions. The origin of damage is mechanical (manufacturing and load induced defects), and related to the source of radiation (primary or secondary particles flux). Among the lattice defects induced by radiation, the clusters of nano/micro voids are accounted for. The constitutive model takes into account the evolution of mechanically and radiation induced nano/micro damage in the presence of microstructure evolution, reflected by the plastic strain driven dynamic change of proportions between the matrix and the inclusions. The model is multiscale since the processes that occur at different scales (micro, meso, macro) are addressed, and coupled, since both phenomena: phase transformation and damage are described by coupled equations. Application to irradiated corrugated shells, components of thermo-mechanical compensation systems, are presented. | | (40p.) |
16. | Ranachowski Z., Schabowicz K., The contribution of fiber reinforcement system to the overall toughness of cellulose fiber concrete panels, CONSTRUCTION AND BUILDING MATERIALS, ISSN: 0950-0618, DOI: 10.1016/j.conbuildmat.2017.09.067, Vol.156, pp.1028-1034, 2017Ranachowski Z., Schabowicz K., The contribution of fiber reinforcement system to the overall toughness of cellulose fiber concrete panels, CONSTRUCTION AND BUILDING MATERIALS, ISSN: 0950-0618, DOI: 10.1016/j.conbuildmat.2017.09.067, Vol.156, pp.1028-1034, 2017Abstract: The paper concerns the role of cellulose reinforcements in overall mechanical toughness of fiber concrete panels applied as facade building material. The results of mechanical tests performed on specimens in as delivered state as well as on specimens which underwent the procedure of destruction of internal fiber network structure due to pyrolysis are presented. The results of mechanical tests let the authors to calculate the work of fracture for six different mechanical conditions. Moreover the analysis of registered Acoustic Emission (AE) signal had revealed that the investigated process of destruction begins with the brittle crack generation and growth while major damages of reinforcement system appears in later phase of the process. Keywords: Fiber cement panels, Cellulose fibers, Brittle crack, Acoustic Emission | | (40p.) |
17. | Piechocka I.K.^{♦}, Kurniawan N.A., Grimbergen J., Koopman J., Koenderink G.H., Recombinant fibrinogen reveals the differential roles of α- and γ-chain cross-linking and molecular heterogeneity in fibrin clot strain-stiffening, Journal of Thrombosis and Haemostasis, ISSN: 1538-7933, DOI: 10.1111/jth.13650, Vol.15, No.5, pp.938-949, 2017Piechocka I.K.^{♦}, Kurniawan N.A., Grimbergen J., Koopman J., Koenderink G.H., Recombinant fibrinogen reveals the differential roles of α- and γ-chain cross-linking and molecular heterogeneity in fibrin clot strain-stiffening, Journal of Thrombosis and Haemostasis, ISSN: 1538-7933, DOI: 10.1111/jth.13650, Vol.15, No.5, pp.938-949, 2017Abstract: Essentials Fibrinogen circulates in human plasma as a complex mixture of heterogeneous molecular variants. We measured strain-stiffening of recombinantly produced fibrinogen upon clotting. Factor XIII and molecular heterogeneity alter clot elasticity at the protofibril and fiber level. This highlights the hitherto unknown role of molecular composition in fibrin clot mechanics. Keywords: blood coagulation, elasticity, fibrin, polymers, rheology, turbidimetry | | (40p.) |
18. | Krajewski M., Magnetic-field-induced synthesis of magnetic wire-like micro- and nanostructures, NANOSCALE, ISSN: 2040-3364, DOI: 10.1039/c7nr05823c, Vol.9, No.43, pp.16511-16545, 2017Krajewski M., Magnetic-field-induced synthesis of magnetic wire-like micro- and nanostructures, NANOSCALE, ISSN: 2040-3364, DOI: 10.1039/c7nr05823c, Vol.9, No.43, pp.16511-16545, 2017Abstract: A lot of physical and chemical preparation methods of one-dimensional (1D) structures are known today. Most of them use highly advanced technology or quite complex chemical reagents. This results in their high costs and difficulties with their implementation to a large industrial scale. Hence, new, facile and inexpensive approaches are still sought. One alternative to wire-like structure production is based on the chemical reduction reactions combined with an external magnetic field, which acts as an independent synthesis parameter. This approach is commonly called magnetic-field-assisted (MFA) synthesis or magnetic-field-induced (MFI) synthesis. As usual, this manufacturing strategy comprises both drawbacks and advantages, which are introduced in this review. Moreover, this work shows that MFI synthesis depends on several synthesis parameters including the strength of the applied magnetic field, reaction temperature, pH value of the reaction environment, chemical composition of the precursor solution, reaction time, and also the presence of surfactants, complexing agents, nucleating agents, initiators as well as organic solvents. All of them have an impact on the morphology and dimensions of wire-like materials and their chemical, physical and mechanical properties. Finally, the opportunities and challenges associated with the magnetic-assisted fabrication of wire-like structures are widely discussed in this review Keywords: magnetic-field-induced synthesis, nanowire, microwire, nanochain, nanostructure, one-dimensional nanostructures | | (40p.) |
19. | Tudelska K., Markiewicz J., Kochańczyk M., Czerkies M., Prus W., Korwek Z., Abdi A., Błoński S., Kaźmierczak B., Lipniacki T., Information processing in the NF-κB pathway, Scientific Reports, ISSN: 2045-2322, DOI: 10.1038/s41598-017-16166-y, Vol.7, pp.15926-15926, 2017Tudelska K., Markiewicz J., Kochańczyk M., Czerkies M., Prus W., Korwek Z., Abdi A., Błoński S., Kaźmierczak B., Lipniacki T., Information processing in the NF-κB pathway, Scientific Reports, ISSN: 2045-2322, DOI: 10.1038/s41598-017-16166-y, Vol.7, pp.15926-15926, 2017Abstract: The NF-κB pathway is known to transmit merely 1 bit of information about stimulus level. We combined experimentation with mathematical modeling to elucidate how information about TNF concentration is turned into a binary decision. Using Kolmogorov-Smirnov distance, we quantified the cell’s ability to discern 8 TNF concentrations at each step of the NF-κB pathway, to find that input discernibility decreases as signal propagates along the pathway. Discernibility of low TNF concentrations is restricted by noise at the TNF receptor level, whereas discernibility of high TNF concentrations it is restricted by saturation/depletion of downstream signaling components. Consequently, signal discernibility is highest between 0.03 and 1 ng/ml TNF. Simultaneous exposure to TNF or LPS and a translation inhibitor, cycloheximide, leads to prolonged NF-κB activation and a marked increase of transcript levels of NF-κB inhibitors, IκBα and A20. The impact of cycloheximide becomes apparent after the first peak of nuclear NF-κB translocation, meaning that the NF-κB network not only relays 1 bit of information to coordinate the all-or-nothing expression of early genes, but also over a longer time course integrates information about other stimuli. The NF-κB system should be thus perceived as a feedback-controlled decision-making module rather than a simple information transmission channel. Keywords: cellular signaling networks, innate immunity, stress signaling | | (40p.) |
20. | Żuk P.J., Cichocki B., Szymczak P., Intrinsic viscosity of macromolecules within the generalized Rotne–Prager–Yamakawa approximation, JOURNAL OF FLUID MECHANICS, ISSN: 0022-1120, DOI: 10.1017/jfm.2017.264, Vol.822, pp.R2-1-11, 2017Żuk P.J., Cichocki B., Szymczak P., Intrinsic viscosity of macromolecules within the generalized Rotne–Prager–Yamakawa approximation, JOURNAL OF FLUID MECHANICS, ISSN: 0022-1120, DOI: 10.1017/jfm.2017.264, Vol.822, pp.R2-1-11, 2017Abstract: We develop a generalized Rotne–Prager–Yamakawa approximation for the dipolar components of the inverse friction matrix and use it for calculating the intrinsic viscosity of rigidly connected bead conglomerates. Such bead models are commonly used in the calculation of hydrodynamic properties of macromolecules. We consider both the case of non-overlapping constituent beads as well as overlapping beads of different sizes. We demonstrate the accuracy of the approximation in two test cases and show that it performs well even if the distances between the beads are small or if the beads overlap. Robust performance of this approximation in the case of overlapping beads stems from its correct limiting behaviour at a complete overlap, with one sphere fully immersed in the other. The generalized Rotne–Prager–Yamakawa approximation is thus well suited for evaluation of intrinsic viscosity, which is a key quantity in characterizing molecular conformations of biological macromolecules. Keywords: complex ﬂuids, low-Reynolds-number ﬂows, mathematical foundations | | (40p.) |
21. | Kowalewski P.K., Olszewski R., Walędziak M.S., Janik M.R., Kwiatkowski A., Gałązka-Świderek N., Cichoń K., Brągoszewski J., Paśnik K., Long-Term Outcomes of Laparoscopic Sleeve Gastrectomy—a Single-Center, Retrospective Study
, Obesity Surgery, ISSN: 0960-8923, DOI: 10.1007/s11695-017-2795-2, pp.1-5, 2017Kowalewski P.K., Olszewski R., Walędziak M.S., Janik M.R., Kwiatkowski A., Gałązka-Świderek N., Cichoń K., Brągoszewski J., Paśnik K., Long-Term Outcomes of Laparoscopic Sleeve Gastrectomy—a Single-Center, Retrospective Study
, Obesity Surgery, ISSN: 0960-8923, DOI: 10.1007/s11695-017-2795-2, pp.1-5, 2017Abstract: Introduction Sleeve gastrectomy (LSG) is one of the most
popular bariatric procedures. We present our long-term results
regarding weight loss, comorbidities, and gastric reflux
disease.
Material and Methods We identified patients who underwent
LSG in our institution between 2006 and 2009. We revised the
data, and the patients with outdated contact details were
tracked with the national health insurance database and social
media (facebook). Each of the identified patients was asked to
complete an online or telephone survey covering, among
others, their weight and comorbidities. On that basis, we calculated
the percent total weight loss (%TWL) and percent
excess weight loss (%EWL), along with changes in body mass
index (ΔBMI). Satisfactory weight loss was set at >50% EWL
(for BMI = 25 kg/m2
). We evaluated type 2 diabetes (T2DM)
and arterial hypertension (AHT) based on the pharmacological
therapy. GERD presence was evaluated by the typical
symptoms and/or proton pump inhibitor (PPI) therapy.
Results One hundred twenty-seven patients underwent LSG
between 2006 and 2009. One hundred twenty patients were
qualified for this study. Follow-up data was available for 100
participants (47 female, 53 male). Median follow-up period
reached 8.0 years (from 7.1 to 10.7). Median BMI upon qualification
for LSG was 51.6 kg/m2
. Sixteen percent of patients
required revisional surgery over the years (RS group), mainly
because of insufficient weight loss (14 Roux-Y gastric bypass—LRYGB;
one mini gastric bypass, one gastric banding).
For the LSG (LSG group n = 84), the mean %EWL was
51.1% (±22.3), median %TWL was 23.5% (IQR 17.7–
33.3%), and median ΔBMI was 12.1 kg/m2 (IQR 8.2–17.2).
Fifty percent (n = 42) of patients achieved the satisfactory
%EWL of 50%. For RS group, the mean %EWL was 57.8%
(±18.2%) and median %TWL reached 33% (IQR 27.7–
37.9%). Sixty-two percent (n = 10) achieved the satisfactory
weight loss. Fifty-nine percent of patients reported improvement
in AHT therapy, 58% in T2DM. After LSG, 60%
(n = 60) of patients reported recurring GERD symptoms and
44% were treated with proton pomp inhibitors (PPI). In 93%
of these cases, GERD has developed de novo.
Conclusions Isolated LSG provides fairly good effects in a
long-term follow-up with mean %EWL at 51.1%. Sixteen
percent of patients require additional surgery due to insufficient
weight loss. More than half of the subjects observe improvement
in AHT and T2DM. Over half of the patients complain
of GERD symptoms, which in most of the cases is a de
novo complaint. Keywords: Bariatricsurgery, Sleeve, Long-termfollow-up, Comorbidities, GERD
| | (40p.) |
22. | Trots I., Nowicki A., Postema M.^{♦}, Ultrasound Image Improvement by Code Bit Elongation, IEEE SIGNAL PROCESSING LETTERS, ISSN: 1070-9908, DOI: 10.1109/LSP.2017.2776040, pp.1-5, 2017Trots I., Nowicki A., Postema M.^{♦}, Ultrasound Image Improvement by Code Bit Elongation, IEEE SIGNAL PROCESSING LETTERS, ISSN: 1070-9908, DOI: 10.1109/LSP.2017.2776040, pp.1-5, 2017Abstract: This paper analyses the influence of the transducer bandwidth on the compression and the axial resolution of an ultrasound image. The distortion of an electrical signal visible in the final image is a major problem in ultrasonography. To solve this problem, the bit length in Golay-complementary sequences was elongated, narrowing the fractional bandwidth of the coded sequences. Therefore, more energy of the burst signal could be transferred through the ultrasound transducer. The experimental results obtained for transmission of the complementary Golay-coded sequences with two different bit lengths - one-cycle and two-cycles - have been compared, and the efficiency of the pulse compression and its influence on the axial resolution for two fractional bandwidths have been discussed. The results are presented for two transducers having a fractional bandwidth of 25% and 80% and operating at a 6-MHz frequency. The results obtained show that the elongation of the Golay single bit length (doubled in our case) compensate for the limited transducer bandwidth. 2D ultrasound images of a tissue-mimicking phantom are presented and demonstrate the benefits of the use of two-cycle bit length. Keywords: Coded excitation, Golay sequences, synthetic aperture method, transducer bandwidth, ultrasound imaging | | (40p.) |
23. | Sumelka W., Nowak M., On a general numerical scheme for the fractional plastic flow rule, MECHANICS OF MATERIALS, ISSN: 0167-6636, DOI: 10.1016/j.mechmat.2017.02.005, pp.1-10, 2017Sumelka W., Nowak M., On a general numerical scheme for the fractional plastic flow rule, MECHANICS OF MATERIALS, ISSN: 0167-6636, DOI: 10.1016/j.mechmat.2017.02.005, pp.1-10, 2017Abstract: This paper presents a general numerical scheme for the fractional plastic flow rule, dedicated to a wide class of materials manifesting the non-normality of plastic flow and induced plastic anisotropy. To determine the vector of the plastic flow, a special numerical procedure has been developed, which is applicable for any smooth and convex yield function. The obtained approximation is verified based on an analytical solution. The paper also presents a set of numerical results for the generalised Drucker–Prager model Keywords: Non-normality, Plastic anisotropy, Fractional calculus, Return mapping algorithm | | (40p.) |
24. | Colabella L., Cisilino A.P., Häiat G., Kowalczyk P., Mimetization of the elastic properties of cancellous bone via a parameterized cellular material, Biomechanics and Modeling in Mechanobiology, ISSN: 1617-7959, DOI: 10.1007/s10237-017-0901-y, Vol.16, No.5, pp.1485-1502, 2017Colabella L., Cisilino A.P., Häiat G., Kowalczyk P., Mimetization of the elastic properties of cancellous bone via a parameterized cellular material, Biomechanics and Modeling in Mechanobiology, ISSN: 1617-7959, DOI: 10.1007/s10237-017-0901-y, Vol.16, No.5, pp.1485-1502, 2017Abstract: Bone tissue mechanical properties and trabecular microarchitecture are the main factors that determine the biomechanical properties of cancellous bone. Artificial cancellous microstructures, typically described by a reduced number of geometrical parameters, can be designed to obtain a mechanical behavior mimicking that of natural bone. In this work, we assess the ability of the parameterized microstructure introduced by Kowalczyk (Comput Methods Biomech Biomed Eng 9:135–147, 2006. doi:10.1080/10255840600751473) to mimic the elastic response of cancellous bone. Artificial microstructures are compared with actual bone samples in terms of elasticity matrices and their symmetry classes. The capability of the parameterized microstructure to combine the dominant isotropic, hexagonal, tetragonal and orthorhombic symmetry classes in the proportions present in the cancellous bone is shown. Based on this finding, two optimization approaches are devised to find the geometrical parameters of the artificial microstructure that better mimics the elastic response of a target natural bone specimen: a Sequential Quadratic Programming algorithm that minimizes the norm of the difference between the elasticity matrices, and a Pattern Search algorithm that minimizes the difference between the symmetry class decompositions. The pattern search approach is found to produce the best results. The performance of the method is demonstrated via analyses for 146 bone samples. Keywords: Cancellous bone, Parameterized microstructure, Elastic properties, Homogenization, Symmetry classes, Optimization | | (35p.) |
25. | Piotrzkowska-Wróblewska H., Dobruch-Sobczak K., Byra M., Nowicki A., Open access database of raw ultrasonic signals acquired from malignant and benign breast lesions, Medical Physics, ISSN: 0094-2405, DOI: 10.1002/mp.12538, Vol.44, No.9, pp.1-5, 2017Piotrzkowska-Wróblewska H., Dobruch-Sobczak K., Byra M., Nowicki A., Open access database of raw ultrasonic signals acquired from malignant and benign breast lesions, Medical Physics, ISSN: 0094-2405, DOI: 10.1002/mp.12538, Vol.44, No.9, pp.1-5, 2017Abstract: Purpose: The aim of this paper is to provide access to a database consisting of the raw radio-frequency ultrasonic echoes acquired from malignant and benign breast lesions. The database is freely available for study and signal analysis.
Acquisition and validation methods: The ultrasonic radio-frequency echoes were recorded from breast focal lesions of patients of the Institute of Oncology in Warsaw. The data were collected between 11/2013 and 10/2015. Patients were examined by a radiologist with 18 yr’ experience in the ultrasonic examination of breast lesions. The set of data includes scans from 52 malignant and 48 benign breast lesions recorded in a group of 78 women. For each lesion, two individual orthogonal scans from the pathological region were acquired with the Ultrasonix SonixTouch Research ultrasound scanner using the L14-5/38 linear array transducer. All malignant lesions were histologically assessed by core needle biopsy. In the case of benign lesions, part of them was histologically assessed and another part was observed over a 2-year period. Data format and usage notes: The radio-frequency echoes were stored in Matlab file format. For each scan, the region of interest was provided to correctly indicate the lesion area. Moreover, for each lesion, the BI-RADS category and the lesion class were included. Two code examples of data manipulation are presented. The data can be downloaded via the Zenodo repository (https://doi.org/10.5281/zenodo.545928) or the website http ://bluebox.ippt.gov.pl/~hpiotrzk.
Potential applications: The database can be used to test quantitative ultrasound techniques and ultrasound image processing algorithms, or to develop computer-aided diagno sis systems. Keywords: breast lesions, dataset, ultrasonic signals, ultrasonography | | (35p.) |
26. | Lanzi M., Salatelli E., Giorgini L., Mucci A., Pierini F., Di-Nicola F.P., Water-soluble polythiophenes as efficient charge-transport layers for the improvement of photovoltaic performance in bulk heterojunction polymeric solar cells, EUROPEAN POLYMER JOURNAL, ISSN: 0014-3057, DOI: 10.1016/j.eurpolymj.2017.10.032, Vol.97, pp.378-388, 2017Lanzi M., Salatelli E., Giorgini L., Mucci A., Pierini F., Di-Nicola F.P., Water-soluble polythiophenes as efficient charge-transport layers for the improvement of photovoltaic performance in bulk heterojunction polymeric solar cells, EUROPEAN POLYMER JOURNAL, ISSN: 0014-3057, DOI: 10.1016/j.eurpolymj.2017.10.032, Vol.97, pp.378-388, 2017Abstract: Water-soluble regioregular poly{3-[(6-sodium sulfonate)hexyl]thiophene} (PT6S) and poly{3-[(6-trimethylammoniumbromide)hexyl]thiophene} (PT6N) have been synthesized and employed both as photoactive layers for the assembling of “green” bulk-heterojunction organic solar cells and as charge-collection layers in a cell with “classic” architecture. While the photovoltaic performances obtained with the two aforementioned polymers were lower than the reference cell, their latter use allowed to notably increase the inherent J-V properties, leading to a considerable enhancement in the overall photovoltaic output. The power conversion efficiency of the optimized multilayer BHJ solar cell reached 4.78%, revealing a higher efficiency than the reference cell (3.63%). Keywords: Water-soluble polymer, Polythiophene derivative, Bulk heterojunction, Organic photovoltaic, Interfacial layer | | (35p.) |
27. | Zakrzewska K.E.^{♦}, Samluk A., Wencel A., Dudek K., Pijanowska D.G., Pluta K.D., Liver tissue fragments obtained from males are the most promising source of human hepatocytes for cell-based therapies – Flow cytometric analysis of albumin expression, PLOS ONE, ISSN: 1932-6203, DOI: 10.1371/journal.pone.0182846, Vol.12, No.8, pp.1-14, 2017Zakrzewska K.E.^{♦}, Samluk A., Wencel A., Dudek K., Pijanowska D.G., Pluta K.D., Liver tissue fragments obtained from males are the most promising source of human hepatocytes for cell-based therapies – Flow cytometric analysis of albumin expression, PLOS ONE, ISSN: 1932-6203, DOI: 10.1371/journal.pone.0182846, Vol.12, No.8, pp.1-14, 2017Abstract: Cell-based therapies that could provide an alternative treatment for the end-stage liver disease require an adequate source of functional hepatocytes. There is little scientific evidence for the influence of patient’s age, sex, and chemotherapy on the cell isolation efficiency and metabolic activity of the harvested hepatocytes. The purpose of this study was to investigate whether hepatocytes derived from different sources display differential viability and biosynthetic capacity. Liver cells were isolated from 41 different human tissue specimens. Hepatocytes were labeled using specific antibodies and analyzed using flow cytometry. Multiparametric analysis of the acquired data revealed statistically significant differences between some studied groups of patients. Generally, populations of cells isolated from the male specimens had greater percentage of biosynthetically active hepatocytes than those from the female ones regardless of age and previous chemotherapy of the patient. Based on the albumin staining (and partially on the α-1-antitrypsin labeling) after donor liver exclusion (6 out of 41 samples), our results indicated that: 1. samples obtained from males gave a greater percentage of active hepatocytes than those from females (p = 0.034), and 2. specimens from the males after chemotherapy greater than those from the treated females (p = 0.032). | | (35p.) |
28. | Pawłowska S., Nakielski P., Pierini F., Piechocka I.K., Zembrzycki K., Kowalewski T.A., Lateral migration of electrospun hydrogel nanofilaments in an oscillatory flow, PLOS ONE, ISSN: 1932-6203, DOI: 10.1371/journal.pone.0187815, Vol.12, No.11, pp.1-21, 2017Pawłowska S., Nakielski P., Pierini F., Piechocka I.K., Zembrzycki K., Kowalewski T.A., Lateral migration of electrospun hydrogel nanofilaments in an oscillatory flow, PLOS ONE, ISSN: 1932-6203, DOI: 10.1371/journal.pone.0187815, Vol.12, No.11, pp.1-21, 2017Abstract: The recent progress in bioengineering has created great interest in the dynamics and manipulation of long, deformable macromolecules interacting with fluid flow. We report experimental data on the cross-flow migration, bending, and buckling of extremely deformable hydrogel nanofilaments conveyed by an oscillatory flow into a microchannel. The changes in migration velocity and filament orientation are related to the flow velocity and the filament’s initial position, deformation, and length. The observed migration dynamics of hydrogel filaments qualitatively confirms the validity of the previously developed worm-like bead-chain hydrodynamic model. The experimental data collected may help to verify the role of hydrodynamic interactions in molecular simulations of long molecular chains dynamics. | | (35p.) |
29. | Kiełczyński P., Ptasznik S., Szalewski M., Balcerzak A., Wieja K., Rostocki A.J., Thermophysical properties of rapeseed oil methyl esters (RME) at high pressures and various temperatures evaluated by ultrasonic methods, Biomass and Bioenergy, ISSN: 0961-9534, DOI: 10.1016/j.biombioe.2017.09.015, Vol.107, pp.113-121, 2017Kiełczyński P., Ptasznik S., Szalewski M., Balcerzak A., Wieja K., Rostocki A.J., Thermophysical properties of rapeseed oil methyl esters (RME) at high pressures and various temperatures evaluated by ultrasonic methods, Biomass and Bioenergy, ISSN: 0961-9534, DOI: 10.1016/j.biombioe.2017.09.015, Vol.107, pp.113-121, 2017Abstract: Investigation of the high-pressure thermophysical properties of biofuels, e.g., bulk modulus, Surface tension, and viscosity is of paramount importance in fuel injection systems in diesel engines. Another crucial and dangerous phenomenon that may occur in biofuels at high pressures is phase transition (solidification), which can drastically increase the viscosity of the biofuel. This effect may hamper proper operation of the engine, especially under cold-start conditions. Unfortunately, the availability of highpressure thermophysical properties of biofuels is still limited. The goal of this paper is to investigate the impact of high pressures on thermophysical properties of biofuels on the example of rapeseed fatty acid methyl esters (RME) in a wide range of pressures (0:1 to 250 MPa) and temperatures (5 to 20 _C). To this end we employed innovative ultrasonic techniques, i.e., the Bleustein-Gulyaev surface acoustic waves for measuring RME viscosity, and ultrasonic bulk compressional waves for measuring sound velocity in RME and consequently evaluating RME thermophysical parameters, e.g., bulk modulus and surface tension. The viscosity of the measured RME displayed an abrupt increase at pressures: 260 MPa (t Ľ 20 _C), 230 MPa (t Ľ 15 _C), 190 MPa (t Ľ 10 _C), and 130 MPa (t Ľ 5 _C). Evidently it was a signature of the phase transition (solidification) occurring in the RME. The discovered high viscosity high-pressure phase in RME can be very detrimental for operation of modern common rail Diesel engines. Therefore, the results of research presented in this paper should be interesting for engineers and designers working with modern common rail Diesel engines using biofuels. Keywords: Biofuels; Methyl esters; Phase transitions; Viscosity; Speed of sound; Ultrasonic methods; High pressure | | (35p.) |
30. | Pietrzak K.^{♦}, Strojny-Nędza A., Olesińska W., Bańkowska A., Gładki A., Cu-rGO subsurface layer creation on copper substrate and its resistance to oxidation, APPLIED SURFACE SCIENCE, ISSN: 0169-4332, DOI: 10.1016/j.apsusc.2016.11.155, Vol.421, pp.228-233, 2017Pietrzak K.^{♦}, Strojny-Nędza A., Olesińska W., Bańkowska A., Gładki A., Cu-rGO subsurface layer creation on copper substrate and its resistance to oxidation, APPLIED SURFACE SCIENCE, ISSN: 0169-4332, DOI: 10.1016/j.apsusc.2016.11.155, Vol.421, pp.228-233, 2017Abstract: On the basis of a specially designed experiment, this paper presents a model, which is an attempt to explain the mechanism of formatting and creating oxidation resistance of Cu-rGO subsurface layers. Practically zero chemical affinity of copper to carbon is a fundamental difficulty in creating composite structures of Cu-C, properties which are theoretically possible to estimate. In order to bind the thermally reduced graphene oxide with copper surface, the effect of structural rebuilding of the copper oxide, in the process of annealing in a nitrogen atmosphere, have been used. On intentionally oxidized and anoxic copper substrates the dispersed graphene oxide (GO) and thermally reduced graphene oxide (rGO) were loaded. Annealing processes after the binding effects of both graphene oxide forms to Cu substrates were tested. The methods for high-resolution electron microscopy were found subsurface rGO-Cu layer having a substantially greater resistance to oxidation than pure copper. The mechanism for the effective resistance to oxidation of the Cu-rGO has been presented in a hypothetical form Keywords: Metal matrix composite, Copper, Graphene, Oxidation | | (35p.) |
31. | Rezaee Hajidehi M., Stupkiewicz S., Gradient-enhanced model and its micromorphic regularization for simulation of Lüders-like bands in shape memory alloys, INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, ISSN: 0020-7683, DOI: 10.1016/j.ijsolstr.2017.11.021, pp.1-11, 2017Rezaee Hajidehi M., Stupkiewicz S., Gradient-enhanced model and its micromorphic regularization for simulation of Lüders-like bands in shape memory alloys, INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, ISSN: 0020-7683, DOI: 10.1016/j.ijsolstr.2017.11.021, pp.1-11, 2017Abstract: Shape memory alloys, notably NiTi, often exhibit softening pseudoelastic response that results in formation and propagation of Lüders-like bands upon loading, for instance, in uniaxial tension. A common approach to modelling softening and strain localization is to resort to gradient-enhanced formulations that are capable of restoring well-posedness of the boundary-value problem. This approach is also followed in the present paper by introducing a gradient-enhancement into a simple one-dimensional model of pseudoelasticity. In order to facilitate computational treatment, a micromorphic-type regularization of the gradient-enhanced model is subsequently performed. The formulation employs the incremental energy minimization framework that is combined with the augmented Lagrangian treatment of the resulting non-smooth minimization problem. A thermomechanically coupled model is also formulated and implemented in a finite-element code. The effect of the loading rate on the localization pattern in a NiTi wire under tension is studied, and the features predicted by the model show a good agreement with the experimental observations. Aditionally, an analytical solution is provided for a propagating interface (macroscopic transformation front) both for the gradient-enhanced model and for its micromorphic version Keywords: martensite, phase transformation, micromorphic model, strain localization, thermomechanical coupling | | (35p.) |
32. | Jaruszewicz-Błońska J., Lipniacki T., Genetic toggle switch controlled by bacterial growth rate, BMC SYSTEMS BIOLOGY, ISSN: 1752-0509, DOI: 10.1186/s12918-017-0483-4, Vol.11, pp.117-1-11, 2017Jaruszewicz-Błońska J., Lipniacki T., Genetic toggle switch controlled by bacterial growth rate, BMC SYSTEMS BIOLOGY, ISSN: 1752-0509, DOI: 10.1186/s12918-017-0483-4, Vol.11, pp.117-1-11, 2017Abstract: Background
In favorable conditions bacterial doubling time is less than 20 min, shorter than DNA replication time. In E. coli a single round of genome replication lasts about 40 min and it must be accomplished about 20 min before cell division. To achieve such fast growth rates bacteria perform multiple replication rounds simultaneously. As a result, when the division time is as short as 20 min E. coli has about 8 copies of origin of replication (ori) and the average copy number of the genes situated close to ori can be 4 times larger than those near the terminus of replication (ter). It implies that shortening of cell cycle may influence dynamics of regulatory pathways involving genes placed at distant loci.
Results
We analyze this effect in a model of a genetic toggle switch, i.e. a system of two mutually repressing genes, one localized in the vicinity of ori and the other localized in the vicinity of ter. Using a stochastic model that accounts for cell growth and divisions we demonstrate that shortening of the cell cycle can induce switching of the toggle to the state in which expression of the gene placed near ter is suppressed. The toggle bistability causes that the ratio of expression of the competing genes changes more than two orders of magnitude for a two-fold change of the doubling time. The increasing stability of the two toggle states enhances system sensitivity but also its reaction time.
Conclusions
By fusing the competing genes with fluorescent tags this mechanism could be tested and employed to create an indicator of the doubling time. By manipulating copy numbers of the competing genes and locus of the gene situated near ter, one can obtain equal average expression of both genes for any doubling time T between 20 and 120 min. Such a toggle would accurately report departures of the doubling time from T. Keywords: Mathematical modeling, Stochastic simulations, Regulatory pathways, Bistability, DNA replication, Gene
copy number | | (35p.) |
33. | Maździarz M., Mrozek A., Kuś W., Burczyński T., First-principles study of new X-graphene and Y-graphene polymorphs generated by the two stage strategy, MATERIALS CHEMISTRY AND PHYSICS, ISSN: 0254-0584, DOI: 10.1016/j.matchemphys.2017.08.066, Vol.202, pp.7-14, 2017Maździarz M., Mrozek A., Kuś W., Burczyński T., First-principles study of new X-graphene and Y-graphene polymorphs generated by the two stage strategy, MATERIALS CHEMISTRY AND PHYSICS, ISSN: 0254-0584, DOI: 10.1016/j.matchemphys.2017.08.066, Vol.202, pp.7-14, 2017Abstract: Two potentially new, 2D-graphene-like materials have been generated by the two stage searching strategy combining molecular and ab initio approach. The two candidates obtained from the evolutionary based algorithm and molecular calculations were then in depth analysed using first-principles Density Functional Theory from the mechanical, structural, phonon and electronic properties point of view. Both proposed polymorphs of graphene (oP8-P2mm) are mechanically and dynamically stable and can be metallic-like. Keywords: Carbon; Graphene; Ab initio calculations; Mechanical properties; Elastic properties | | (30p.) |
34. | Pierini F., Lanzi M., Nakielski P., Kowalewski T.A., Electrospun Polyaniline-Based Composite Nanofibers: Tuning the Electrical Conductivity by Tailoring the Structure of Thiol-Protected Metal Nanoparticles, Journal of Nanomaterials, ISSN: 1687-4110, DOI: 10.1155/2017/6142140, Vol.2017, pp.1-10, 2017Pierini F., Lanzi M., Nakielski P., Kowalewski T.A., Electrospun Polyaniline-Based Composite Nanofibers: Tuning the Electrical Conductivity by Tailoring the Structure of Thiol-Protected Metal Nanoparticles, Journal of Nanomaterials, ISSN: 1687-4110, DOI: 10.1155/2017/6142140, Vol.2017, pp.1-10, 2017Abstract: Composite nanofibers made of a polyaniline-based polymer blend and different thiol-capped metal nanoparticles were prepared using ex situ synthesis and electrospinning technique. The effects of the nanoparticle composition and chemical structure on the electrical properties of the nanocomposites were investigated. This study confirmed that Brust’s procedure is an effective method for the synthesis of sub-10 nm silver, gold, and silver-gold alloy nanoparticles protected with different types of thiols. Electron microscopy results demonstrated that electrospinning is a valuable technique for the production of composite nanofibers with similar morphology and revealed that nanofillers are well-dispersed into the polymer matrix. X-ray diffraction tests proved the lack of a significant influence of the nanoparticle chemical structure on the polyaniline chain arrangement. However, the introduction of conductive nanofillers in the polymer matrix influences the charge transport noticeably improving electrical conductivity. The enhancement of electrical properties is mediated by the nanoparticle capping layer structure. The metal nanoparticle core composition is a key parameter, which exerted a significant influence on the conductivity of the nanocomposites. These results prove that the proposed method can be used to tune the electrical properties of nanocomposites. | | (30p.) |
35. | Pietrzak K.^{♦}, Gładki A., Frydman K., Wójcik-Grzybek D., Strojny-Nędza A., Wejrzanowski T., COPPER-CARBON NANOFORMS COMPOSITES – PROCESSING, MICROSTRUCTURE AND THERMAL PROPERTIES, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.1515/amm-2017-0198, Vol.62, No.2B, pp.1307-1310, 2017Pietrzak K.^{♦}, Gładki A., Frydman K., Wójcik-Grzybek D., Strojny-Nędza A., Wejrzanowski T., COPPER-CARBON NANOFORMS COMPOSITES – PROCESSING, MICROSTRUCTURE AND THERMAL PROPERTIES, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.1515/amm-2017-0198, Vol.62, No.2B, pp.1307-1310, 2017Abstract: The main current of publication is focused around the issues and problems associated with the formation of composite materials with Cu matrix and reinforcing phases in the various carbon nanoforms. The core of the research has been focused on thermal conductivity of these composites types. This parameter globally reflects the state of the structure, quality of raw materials and the technology used during the formation of composite materials. Vanishingly low affinity of copper for carbon, multilayered forms of graphene, the existence of critical values of graphene volume in the composite are not conducive to the classic procedures of composites designing. As a result, the expected, significant increase in thermal conductivity of composites is not greater than for pure copper matrix. Present paper especially includes: (i) data of obtaining procedure of copper/graphene mixtures, (ii) data of sintering process, (iii) the results of structure investigations and of thermal properties. Structural analysis revealed the homogenous distribution of graphene in copper matrix, the thermal analysis indicate the existence of carbon phase critical concentration, where improvement of thermal diffusivity to pure copper can occur Keywords: metal matrix composite, sintering, copper, graphene, thermal diffusivity | | (30p.) |
36. | Zybała R., Mars K., Mikuła A., Bogusławski J., Soboń G., Sotor J., Schmidt M., Kaszyca K., Chmielewski M., Ciupiński L., Pietrzak K.^{♦}, SYNTHESIS AND CHARACTERIZATION OF ANTIMONY TELLURIDE FOR THERMOELECTRIC AND OPTOELECTRONIC APPLICATIONS, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.1515/amm-2017-0155, Vol.62, No.2B, pp.1067-1070, 2017Zybała R., Mars K., Mikuła A., Bogusławski J., Soboń G., Sotor J., Schmidt M., Kaszyca K., Chmielewski M., Ciupiński L., Pietrzak K.^{♦}, SYNTHESIS AND CHARACTERIZATION OF ANTIMONY TELLURIDE FOR THERMOELECTRIC AND OPTOELECTRONIC APPLICATIONS, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.1515/amm-2017-0155, Vol.62, No.2B, pp.1067-1070, 2017Abstract: Antimony telluride (Sb2Te3) is an intermetallic compound crystallizing in a hexagonal lattice with R-3m space group. It creates a c lose packed structure of an ABCABC type. As intrinsic semiconductor characterized by excellent electrical properties, Sb2Te3 is widely used as a low-temperature thermoelectric material. At the same time, due to unusual properties (strictly connected with the structure), antimony telluride exhibits nonlinear optical properties, including saturable absorption. Nanostructurization, elemental doping and possibilities of synthesis Sb2Te3 in various forms (polycrystalline, single crystal or thin film) are the most promising methods for improving thermoelectric properties of Sb2Te3.Applications of Sb2Te3 in optical devices (e.g. nonlinear modulator, in particular saturable absorbers for ultrafast lasers) are also interesting. The antimony telluride in form of bulk polycrystals and layers for thermoelectric and optoelectronic applications respectively were used. For optical applications thin layers of the material were formed and studied. Synthesis and structural characterization of Sb2Te3 were also presented here. The anisotropy (packed structure) and its influence on thermoelectric properties have been performed. Furthermore, preparation and characterization of Sb2Te3 thin films for optical uses have been also made Keywords: antimony telluride, thermoelectric materials, thin films, PVD magnetron sputtering, topological insulator | | (30p.) |
37. | Orłowska A., Graczykowski C., Gałęzia A., The effect of prestress force magnitude on the natural bending frequencies of the eccentrically prestressed glass fibre reinforced polymer composite beams, Journal of Composite Materials, ISSN: 0021-9983, DOI: 10.1177/0021998317740202, pp.1-14, 2017Orłowska A., Graczykowski C., Gałęzia A., The effect of prestress force magnitude on the natural bending frequencies of the eccentrically prestressed glass fibre reinforced polymer composite beams, Journal of Composite Materials, ISSN: 0021-9983, DOI: 10.1177/0021998317740202, pp.1-14, 2017Abstract: This paper studies the effect of prestress force magnitude on natural frequencies and dynamic behaviour of eccentrically prestressed glass fibre reinforced polymer composite beams, including the theoretical background, numerical results and experimental verification. The term prestress indicates the initial tensile stress applied to the fibres embedded in selected external layers of the composite material. First, the paper presents the theoretical background of the finite element method modelling of prestressed composites. Then, the results of numerical simulations conducted for a five-layered glass-epoxy composite beam are presented. The natural frequencies corresponding to three initial bending modes are analyzed for different prestressing force levels and for different fibre volume content. Finally, the results are verificated by experimental modal analysis conducted on three different glass-epoxy composite specimens of various mechanical parameters. Both the numerical results obtained from finite element method and the experimental results obtained from experimental modal analysis reveal that the first bending frequency increases and the two subsequent bending frequencies decrease due to the prestressing force. The comparison of numerical and experimental data confirms the effect and allows to quantify the influence that the prestress force has on the natural frequencies of composites, which is an interesting and practically relevant phenomenon. Keywords: Prestressed structures, laminated composites, prestressed reinforced composites, glass fibre reinforced polymer composite
materials, vibrations, finite element method | | (30p.) |
38. | Gluba-Brzózka A., Franczyk B., Olszewski R., Banach M., Rysz J., Personalized Medicine: New Perspectives for the Diagnosis and the Treatment of Renal Diseases, International Journal of Molecular Sciences, ISSN: 1422-0067, DOI: 10.3390/ijms18061248, Vol.18, No.1248, pp.1-20, 2017Gluba-Brzózka A., Franczyk B., Olszewski R., Banach M., Rysz J., Personalized Medicine: New Perspectives for the Diagnosis and the Treatment of Renal Diseases, International Journal of Molecular Sciences, ISSN: 1422-0067, DOI: 10.3390/ijms18061248, Vol.18, No.1248, pp.1-20, 2017Abstract: The prevalence of renal diseases is rising and reaching 5–15% of the adult population. Renal damage is associated with disturbances of body homeostasis and the loss of equilibrium between exogenous and endogenous elements including drugs and metabolites. Studies indicate that renal diseases are inﬂuenced not only by environmental but also by genetic factors. In some cases the disease is caused by mutation in a single gene and at that time severity depends on the presence of one or two utated alleles. In other cases, renal disease is associated with the presence of alteration within a gene or genes, but environmental factors are also necessary for the development of disease. Therefore, it seems that the analysis of genetic aspects should be a natural component of clinical and xperimental studies. The goal of personalized medicine is to determine the right drug,for the right patient,at the right time. Whole-genome examinations may help to change the approach to the disease and the patient resulting in the creation of“personalized medicine”with new diagnostic and treatment strategies designed on the basis of genetic background of each individual. The identiﬁcation of high-risk patients in pharmacogenomics analyses will help to avoid many unwarranted side effects while optimizing treatment efﬁcacy for individual patients. Personalized therapies for kidney diseases are still at the preliminary stage mainly due to high costs of such analyses and the complex nature of human genome. This review will focus on several areas of interest: renal disease pathogenesis, diagnosis, treatment, rate of progression and the prediction ofprognosis. Keywords: renal diseases; personalized medicine;treatment;diagnosis;biomarkers
| | (30p.) |
39. | Egner H., Ryś M.^{♦}, Total energy equivalence in constitutive modeling of multidissipative materials, INTERNATIONAL JOURNAL OF DAMAGE MECHANICS, ISSN: 1056-7895, DOI: 10.1177/1056789516679496, Vol.26, No.3, pp.417-446, 2017Egner H., Ryś M.^{♦}, Total energy equivalence in constitutive modeling of multidissipative materials, INTERNATIONAL JOURNAL OF DAMAGE MECHANICS, ISSN: 1056-7895, DOI: 10.1177/1056789516679496, Vol.26, No.3, pp.417-446, 2017Abstract: In the present work, the total energy equivalence hypothesis was applied in constitutive modeling of engineering materials. The approach originally developed for damaged materials, was extended to modeling not only damage but also other dissipative phenomena, like phase transformation, in a consistent manner. The proposed model was examined by means of parametric studies to show its ability to reflect different experimentally observed features of real materials. Keywords: Constitutive modeling, dissipative material, plasticity, damage, phase transformation | | (25p.) |
40. | Takeda K., Matsui R., Tobushi H., Pieczyska E.A., Torsional deformation properties of SMA tapes and their application to bias-type reciprocating rotary driving actuator, ARCHIVES OF MECHANICS, ISSN: 0373-2029, Vol.69, No.4-5, pp.289-303, 2017Takeda K., Matsui R., Tobushi H., Pieczyska E.A., Torsional deformation properties of SMA tapes and their application to bias-type reciprocating rotary driving actuator, ARCHIVES OF MECHANICS, ISSN: 0373-2029, Vol.69, No.4-5, pp.289-303, 2017Abstract: In order to develop the reciprocating rotary driving actuator with a simple mechanism using shape memory alloy (SMA) tapes, the graphical method to design the actuator was proposed based on the torsional deformation properties of SMA tapes. The torsional deformation properties of the SME tape showing the shape memory effect (SME) and the SE tape showing superelasticity (SE) were obtained. The bias-type reciprocating rotary actuator was composed of the pretwisted SME tape and the flat SE tape in series. The design chart expressed by the relationship between torque and twisting angle of the SME tape and the SE tape was proposed. The rotational angle and torque, which vary depending on temperature, can be estimated based on the design chart. The rotational angle is controlled by adjusting the mounting angle of the SME tape and the heating temperature. The automatically opening and closing blind driven by sunlight was demonstrated. The blind was controlled by using the reciprocating rotary element composed of the SME tape and the SE tape. The behavior of the blind can be achieved based on the proposed design method of the reciprocating rotary driving element Keywords: shape memory alloy, tape, torsion, actuator, reciprocating rotation, design chart, bias-type | | (25p.) |
41. | Dobruch-Sobczak K., Piotrzkowska-Wróblewska H., Roszkowska-Purska K., Nowicki A., Jakubowski W., Usefulness of combined BI-RADS analysis and Nakagami statistics of ultrasound echoes in the diagnosis of breast lesions, Clinical Radiology, ISSN: 0009-9260, DOI: 10.1016/j.crad.2016.11.009, Vol.72, pp.339.e7-339.e15, 2017Dobruch-Sobczak K., Piotrzkowska-Wróblewska H., Roszkowska-Purska K., Nowicki A., Jakubowski W., Usefulness of combined BI-RADS analysis and Nakagami statistics of ultrasound echoes in the diagnosis of breast lesions, Clinical Radiology, ISSN: 0009-9260, DOI: 10.1016/j.crad.2016.11.009, Vol.72, pp.339.e7-339.e15, 2017Abstract: AIM: To develop a method combining the statistics of the ultrasound backscatter and the Breast Imaging-Reporting and Data System (BI-RADS) classification to enhance the differentiation of breast tumours.
MATERIALS AND METHODS: The Nakagami shape parameter m was used to characterise the scatter properties of breast tumours. Raw data from the radiofrequency (RF) echo-signal and Bmode images from 107 (32 malignant and 75 benign) lesions and their surrounding tissue were recorded. Three different characteristic values of the shape parameters of m (maximum [mLmax], minimum [mLmin] and average [mLavg]) and differences between m parameters (Dmmax, Dmmin, Dmavg) of the lesions and their surrounding tissues were assessed. A lesion with a BI-RADS score of 3 was considered benign, while a lesion with a score of 4 was considered malignant (a cut-off of BI-RADS 3/4 was set for all patients).
RESULTS: The area under the receiver operating characteristic (ROC) curve (AUC) was equal to 0.966 for BI-RADS, with 100% sensitivity and 54.67% specificity. All malignant lesions were diagnosed correctly, whereas 34 benign lesions were biopsied unnecessarily. In assessing the Nakagami statistics, the sum of the sensitivity and specificity was the best for mLavg (62.5% and 93.33%, respectively). Only four of 20 lesions were found over the cut-off value in BI-RADS of 4a. When comparing the differences in m parameters, Dmavg had the highest sensitivity of 90% (only three of 32 lesions were false negative). These three lesions were classified as BIRADS category 4c. The combined use of B-mode and mLmin parameter improve the AUC up to 0.978 (pĽ0.088), compared to BI-RADS alone.
CONCLUSION: The combination of the parametric imaging and the BI-RADS assessment does not significantly improve the differentiation of breast lesions, but it has the potential to better identify the group of patients with mainly benign lesions that have a low level of suspicion for malignancy with a BI-RADS score of 4a. | | (25p.) |
42. | Bajer C.I., Dyniewicz B., Shillor M., A Gao beam subjected to a moving inertial point load, Mathematics and Mechanics of Solids, ISSN: 1081-2865, DOI: 10.1177/1081286517718229, pp.1-12, 2017Bajer C.I., Dyniewicz B., Shillor M., A Gao beam subjected to a moving inertial point load, Mathematics and Mechanics of Solids, ISSN: 1081-2865, DOI: 10.1177/1081286517718229, pp.1-12, 2017Abstract: A model for the dynamics of a Gao elastic or viscoelastic nonlinear beam that is subject to a horizontally moving vertical point-force is modeled and computationally studied. In particular, the behavior and vibrations of the beam as the mass is moving on it is investigated. Such problems arise naturally in transportation systems with rails. A time-marching finite element numerical algorithm for the problem is developed and implemented. Results of representative simulations are depicted and compared to the behavior of a linear Euler beam with a moving mass. Keywords: Gao beam, moving inertial point load, Finite Element simulations, beam vibration | | (25p.) |
43. | Rojek J., Nosewicz S., Chmielewski M., MICRO-MACRO RELATIONSHIPS FROM DISCRETE ELEMENT SIMULATIONS OF SINTERING, INTERNATIONAL JOURNAL FOR MULTISCALE COMPUTATIONAL ENGINEERING, ISSN: 1543-1649, DOI: 10.1615/IntJMultCompEng.2017020322, Vol.15, No.4, pp.323-342, 2017Rojek J., Nosewicz S., Chmielewski M., MICRO-MACRO RELATIONSHIPS FROM DISCRETE ELEMENT SIMULATIONS OF SINTERING, INTERNATIONAL JOURNAL FOR MULTISCALE COMPUTATIONAL ENGINEERING, ISSN: 1543-1649, DOI: 10.1615/IntJMultCompEng.2017020322, Vol.15, No.4, pp.323-342, 2017Abstract: A two-scale modeling framework for sintering processes has been presented. Formulation of the micromechanical model of sintering developed in the discrete element method and basic relationships in the macroscopic model of sintering have been briefly reviewed. The methodology to determine macroscopic quantities–stress, strains, and constitutive viscous properties-from the discrete element simulations has been presented. This methodology has been applied to modeling of NiAl sintering. First, the discrete element model (DEM) has been calibrated by fitting the numerical densification curve to the experimental data. The DEM model with calibrated parameters has been used in simulations specially conceived to give macroscopic viscous moduli of the sintered material. Using the averaging procedures macroscopic stresses and strains have been calculated. Strain rates have been obtained differentiating the strain curves with respect to time. Finally, the viscous constitutive properties of the sintered material have been determined. The dependence of the shear and volumetric viscous moduli on the relative density (or equivalently) on the porosity has been obtained. It has been found that the numerical simulations predict a similar dependence as that assumed in the phenomenological macroscopic models. Thus, the validity of the micro-macro relationships obtained from the discrete element simulations of powder sintering has been confirmed. The proposed methodology allows us to use the discrete element model in the framework of multiscale modeling of sintering. Keywords: discrete element method, sintering, simulation, micro-macro relationships, multiscale modeling | | (25p.) |
44. | Maździarz M., Rojek J., Nosewicz S., ESTIMATION OF MICROMECHANICAL NiAl SINTERING MODEL PARAMETERS FROM THE MOLECULAR SIMULATIONS, INTERNATIONAL JOURNAL FOR MULTISCALE COMPUTATIONAL ENGINEERING, ISSN: 1543-1649, DOI: 10.1615/IntJMultCompEng.2017020289 , Vol.15, No.4, pp.343-358, 2017Maździarz M., Rojek J., Nosewicz S., ESTIMATION OF MICROMECHANICAL NiAl SINTERING MODEL PARAMETERS FROM THE MOLECULAR SIMULATIONS, INTERNATIONAL JOURNAL FOR MULTISCALE COMPUTATIONAL ENGINEERING, ISSN: 1543-1649, DOI: 10.1615/IntJMultCompEng.2017020289 , Vol.15, No.4, pp.343-358, 2017Abstract: Molecular statics/dynamics estimation of constitutive parameters for a micromechanical NiAl sintering model is reported in this paper. The parameters include temperature-dependent diffusion coefficients, surface energy, and linear thermal expansion. These parameters define material behavior during sintering and are used in the sintering particle model implemented in the discrete element model. The investigated material, the NiAl intermetallic, belongs to novel materials characterized by advantageous mechanical properties. Various machine elements are manufactured from a pure NiAl powder or from powder mixtures containing the NiAl using the sintering technology. It is well known that sintering is governed by diffusion. Therefore diffusive properties are important parameters of the micromechanical model of sintering. Numerical estimation of the model parameters by simulations at the lower scale is a powerful tool alternative to experimental methods. Molecular statics and dynamics models for NiAl have been created using the embedded atom model potential. Numerical simulations have allowed us to estimate the volume, surface, and grain-boundary diffusivity for the B2-type NiAl in the 1573 to 1673 K temperature range. Dependence of the diffusion coefficients on temperature has been determined and validity of the Arrhenius-type temperature dependency has been assessed. The parameters evaluated numerically have been compared with available experimental data as well as with theoretical predictions obtained with other methods. Many of the results presented in this paper have a pioneer character and are not known in the literature. Keywords: NiAl, sintering, diffusivity, molecular dynamics, molecular statics, nanoparticles | | (25p.) |
45. | Pęcherski R.B., Nowak M., Nowak Z., VIRTUAL METALLIC FOAMS. APPLICATION FOR DYNAMIC CRUSHING ANALYSIS, INTERNATIONAL JOURNAL FOR MULTISCALE COMPUTATIONAL ENGINEERING, ISSN: 1543-1649, Vol.15, No.5, pp.431-442, 2017Pęcherski R.B., Nowak M., Nowak Z., VIRTUAL METALLIC FOAMS. APPLICATION FOR DYNAMIC CRUSHING ANALYSIS, INTERNATIONAL JOURNAL FOR MULTISCALE COMPUTATIONAL ENGINEERING, ISSN: 1543-1649, Vol.15, No.5, pp.431-442, 2017Abstract: The subject of the study are the models based on digital microstructures, in particular open-cell metallic foams characterized with the skeleton formed of convex or re-entrant cells. Recently, the auxetic materials revealing negative Poisson’s ratio have attracted increasing attention in the context of modern materials applications. Up to date, the research of auxetics is mainly concentrating on the cell structure design and the analysis of quasi-static response. The dynamic properties of such materials are less known. Impact compressions of the two kind of foams under high-velocity are numerically analyzed. To simulate the deformation processes the finite element program ABAQUS is used. The computer tomography makes the basis for the formulation of computational model of virtual foam and the finite element discretization of the skeleton. For numerical simulations the constitutive elasto-viscoplasticity model is applied that defines the dynamic behavior of oxygen-free high conductivity (OFHC) Cu using the experimental data reported in the literature. The numerical predictions of crushing force for velocity 50 and 300 m/s are discussed Keywords: compression test, open-cell copper, convex cell, re-entrant cell, virtual cellular materials, metallic foams, numerical simulation | | (25p.) |
46. | Cichocki B., Ekiel-Jeżewska M.L., Wajnryb E., Translational and rotational Brownian displacements of colloidal particles of complex shapes, ARCHIVES OF MECHANICS, ISSN: 0373-2029, Vol.69, No.3, pp.257-267, 2017Cichocki B., Ekiel-Jeżewska M.L., Wajnryb E., Translational and rotational Brownian displacements of colloidal particles of complex shapes, ARCHIVES OF MECHANICS, ISSN: 0373-2029, Vol.69, No.3, pp.257-267, 2017Abstract: The exact analytical expressions for the time-dependent cross-correlations of the translational and rotational Brownian displacements of a particle with arbitrary shape were derived by us in [3, 4]. They are in this work applied to construct a method to analyze the Brownian motion of a particle of an arbitrary shape, and to extract accurately the self-diffusion matrix from the measurements of the crosscorrelations, which in turn allows to gain some information on the particle structure. As an example, we apply our new method to analyze the experimental results of D. J. Kraft et al. for the micrometer-sized aggregates of the beads [8]. We explicitly demonstrate that our procedure, based on the measurements of the time-dependent cross-correlations in the whole range of times, allows to determine the self-diffusion (or alternatively the friction matrix) with a much higher precision than the method based only on their initial slopes. Therefore, the analytical time-dependence of the cross-correlations serves as a useful tool to extract information about particle structure from trajectory measurements. Keywords: Brownian motion, Smoluchowski equation, hydrodynamic interactions, self-diﬀusion matrix, friction coeﬃcients, cross-correlations of translational and rotational Brownian displacements | | (25p.) |
47. | Moćko W.^{♦}, Radziejewska J., Sarzyński A., Strzelec M., Marczak J., Analysis of the plastic deformation of AISI 304 steel induced by the nanosecond laser pulse, OPTICS & LASER TECHNOLOGY, ISSN: 0030-3992, DOI: 10.1016/j.optlastec.2016.11.022, Vol.90, pp.165-173, 2017Moćko W.^{♦}, Radziejewska J., Sarzyński A., Strzelec M., Marczak J., Analysis of the plastic deformation of AISI 304 steel induced by the nanosecond laser pulse, OPTICS & LASER TECHNOLOGY, ISSN: 0030-3992, DOI: 10.1016/j.optlastec.2016.11.022, Vol.90, pp.165-173, 2017Abstract: The paper presents result of experimental and numerical tests of plastic deformation of austenitic steel generated by a nanosecond laser pulse. The shock wave generated by the laser pulse was used to induce local plastic deformation of the material. The study examined the possibility of using the process to develop a laser forming of materials under ultra-high strain rate. It has been shown that the laser pulse with intensity 2.5 GW/cm2 induces a repeatable plastic deformation of commercially available 304 steel without thermal effects on the surface Keywords: Laser pulse, Plastic deformations, Microstructure, Numerical simulations | | (25p.) |
48. | Balcerzak A., Comparison of High-Pressure Behavior of Physicochemical Properties of the Di- and Triacylglycerols Established by Ultrasonic Methods, JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY, ISSN: 0003-021X, DOI: 10.1007/s11746-017-3030-y, Vol.94, No.10, pp.1261-1268, 2017Balcerzak A., Comparison of High-Pressure Behavior of Physicochemical Properties of the Di- and Triacylglycerols Established by Ultrasonic Methods, JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY, ISSN: 0003-021X, DOI: 10.1007/s11746-017-3030-y, Vol.94, No.10, pp.1261-1268, 2017Abstract: Two samples of triacylglycerols i.e., olive oil and triolein, and one sample of diacylglycerol were investigated.
In the course of compression, the density of the samples was determined by measurements of the change of piston position in a pressure chamber and volume correction due to chamber expansion under pressure. The speed of sound was evaluated from the time of flight of an ultrasonic impulse between emitting and receiving transducers placed in the high pressure chamber. The adiabatic compressibility, the intermolecular free length, the molar volume, the van der Waals’ constant b and the surface tension were evaluated from the density, the speed of sound and the average molecular mass. All tested liquids undergo a high-pressure phase transition. Discontinuities in the measured isotherms of the physicochemical parameters of the investigated oils indicate the presence of high-pressure phase transitions. Moreover the time dependent change of pressure at constant volume during the phase transition was measured. The fundamental difference in the molecular structure of these acylglycerols influences their behavior significantly under high pressure.
Keywords: Acylglycerols; Physicochemical parameters; Ultrasonic measurements | | (25p.) |
49. | Wilczek M.M., Olszewski R., Krupienicz A., Trans -Fatty Acids and Cardiovascular Disease: Urgent Need for Legislation , CARDIOLOGY, ISSN: 0008-6312, DOI: 10.1159/000479956 , Vol.138, No.4, pp.254-258, 2017Wilczek M.M., Olszewski R., Krupienicz A., Trans -Fatty Acids and Cardiovascular Disease: Urgent Need for Legislation , CARDIOLOGY, ISSN: 0008-6312, DOI: 10.1159/000479956 , Vol.138, No.4, pp.254-258, 2017Abstract: Hydrogenated oils containing trans -fatty acids (TFA) are used to produce margarine and various processed foods. TFA affect serum lipid levels, fatty acid metabolism, and endothelial function. High TFA intake is linked to increased allcause mortality, coronary heart disease mortality, and cardiovascular disease (CVD) incidence. Denmark was the first country to introduce a law that limited TFA content in food; this action led to lower CVD mortality. So far 7 European countries have followed this practice, in a few others the food industry voluntarily reduced TFA use. The issue remains mostly unaddressed in the rest of the world. Legal TFA limits should be commonly established as they are the optimal solution considering both CVD prevention and the associated cost savings in public healthcare. Keywords: Trans -fatty acids, Cardiovascular disease, Nutrition policy | | (25p.) |
50. | Mrozek A., Kuś W., Burczyński T., METHOD FOR DETERMINING STRUCTURES OF NEW CARBON-BASED 2DMATERIALS WITH PREDEFINED MECHANICAL PROPERTIES, INTERNATIONAL JOURNAL FOR MULTISCALE COMPUTATIONAL ENGINEERING, ISSN: 1543-1649, Vol.15, No.5, pp.379-394, 2017Mrozek A., Kuś W., Burczyński T., METHOD FOR DETERMINING STRUCTURES OF NEW CARBON-BASED 2DMATERIALS WITH PREDEFINED MECHANICAL PROPERTIES, INTERNATIONAL JOURNAL FOR MULTISCALE COMPUTATIONAL ENGINEERING, ISSN: 1543-1649, Vol.15, No.5, pp.379-394, 2017Abstract: The following article presents the description and application of an algorithm for optimal searching for the new stable atomic arrangements of two-dimensional graphenelike carbon lattices with predefined mechanical properties. The proposed method combines the evolutionary algorithm and the conjugate-gradient optimization. The main goal of the optimization is to find stable arrangements of carbon atoms placed in the unit cell with imposed periodic boundary conditions, which reveal desired mechanical properties. Examples of the newly obtained models of the flat, carbon materials are presented. Their mechanical properties are additionally validated during the simulation of the tensile tests using molecular dynamics. Keywords: 2D atomic structures, graphenelike materials, hybrid algorithm, evolutionary algorithm, mechanical properties | | (25p.) |
51. | Roszkiewicz A., Nasalski W., Transmission and reflection properties of two-dimensional finite metal crystals, EUROPEAN PHYSICAL JOURNAL D, ISSN: 1434-6060, DOI: 10.1140/epjd/e2017-70706-9, Vol.71, No.182, pp.1-12, 2017Roszkiewicz A., Nasalski W., Transmission and reflection properties of two-dimensional finite metal crystals, EUROPEAN PHYSICAL JOURNAL D, ISSN: 1434-6060, DOI: 10.1140/epjd/e2017-70706-9, Vol.71, No.182, pp.1-12, 2017Abstract: Optical characteristics of a finite two-dimensional silver stripe photonic crystal of a square lattice are numerically analysed with use of multilayer Rigorous Coupled Wave Analysis. Qualitative changes in optical response of the crystal originated from modifications of the thickness and filling factors of each layer and the polarization direction of the incident wave are shown. The crystal manifests its various characteristics in wideband or narrowband reflection and transmission, while absorption remains low. The behaviour of the crystal is determined by its structure geometry yielding excitation of localized plasmons and collective modes together with interactions between them. The optical response of the square lattice structure is also compared with the response of a triangular lattice crystal. | | (20p.) |
52. | Colabella L., Ibarra Pino A.A., Ballarre J., Kowalczyk P., Cisilino A.P., Calculation of cancellous bone elastic properties with the polarization-based FFT iterative scheme, International Journal for Numerical Methods in Biomedical Engineering, ISSN: 2040-7939, DOI: 10.1002/cnm.2879, Vol.33, No.11, pp.e2879-1-16, 2017Colabella L., Ibarra Pino A.A., Ballarre J., Kowalczyk P., Cisilino A.P., Calculation of cancellous bone elastic properties with the polarization-based FFT iterative scheme, International Journal for Numerical Methods in Biomedical Engineering, ISSN: 2040-7939, DOI: 10.1002/cnm.2879, Vol.33, No.11, pp.e2879-1-16, 2017Abstract: The Fast Fourier Transform–based method, originally introduced by Moulinec and Suquet in 1994 has gained popularity for computing homogenized properties of composites. In this work, the method is used for the computational homogenization of the elastic properties of cancellous bone. To the authors' knowledge, this is the first study where the Fast Fourier Transform scheme is applied to bone mechanics. The performance of the method is analyzed for artificial and natural bone samples of 2 species: bovine femoral heads and implanted femurs of Hokkaido rats. Model geometries are constructed using data from X‐ray tomographies, and the bone tissue elastic properties are measured using microindentation and nanoindentation tests. Computed results are in excellent agreement with those available in the literature. The study shows the suitability of the method to accurately estimate the fully anisotropic elastic response of cancellous bone. Guidelines are provided for the construction of the models and the setting of the algorithm. Keywords: accelerated FFT method, cancellous bone, homogenized elastic properties | | (20p.) |
53. | Chudzikiewicz A., Bogacz R., Kostrzewski M., Konowrocki R., Condition monitoring of railway track systems by using acceleration signals on wheelset axle-boxes, Transport, ISSN: 1648-4142, DOI: 10.3846/16484142.2017.1342101, pp.1-12, 2017Chudzikiewicz A., Bogacz R., Kostrzewski M., Konowrocki R., Condition monitoring of railway track systems by using acceleration signals on wheelset axle-boxes, Transport, ISSN: 1648-4142, DOI: 10.3846/16484142.2017.1342101, pp.1-12, 2017Abstract: The aim of this paper is to demonstrate the possibilities of estimating the track condition using axle-boxes and car-bodies motions described by acceleration signals. In the paper, the results presented indicate the condition of tracks obtained from the preliminary investigation on the test track. Furthermore, the results from the supervised runs (on Polish Railway Lines) of electric multiple unit (EMU-ED74) with the prototype of track quality monitoring system installed on-board are described. As track quality indicator (TQI) algorithm, used in the mentioned prototype, a modified Karhunen–Loève transformation is used in preliminary preparing acceleration signals. The transformation is used to extract the principal dynamics from measurement data. Obtained results are compared to other methods of evaluating the geometrical track quality, namely methods which apply the Jsynth Synthetic Coefficient and Five Parameters of Defectiveness W5. The results from the investigation showed that track condition estimation is possible with acceptable accuracy for in-service use and for defining cost-effective maintenance strategies. Keywords: railway track monitoring, wheel–rail interaction, track quality indicator, acceleration signals, experimental investigation, track degradation. | | (15p.) |
54. | Glinicki M.A., Dąbrowski M., Skrzypczyński M., Influence of curing on the properties of air-entrained concrete in the upper layer of exposed aggregate pavement-modelling study, CEMENT, WAPNO, BETON, ISSN: 1425-8129, Vol.XXII/LXXXIV, No.4, pp.271-281, 2017Glinicki M.A., Dąbrowski M., Skrzypczyński M., Influence of curing on the properties of air-entrained concrete in the upper layer of exposed aggregate pavement-modelling study, CEMENT, WAPNO, BETON, ISSN: 1425-8129, Vol.XXII/LXXXIV, No.4, pp.271-281, 2017Abstract: Modelling studies in laboratory of the effect of curing on the mechanical properties and durability of the concrete pavement with exposed aggregate are presented. Air-entrained concrete was designed as the top layer of a motorway pavement with the use of two types of cements: CEM I and CEM III/A. The w/c increase (from 0.34 to 0.37) and change of cement type (CEM I 42.5N and CEM III/A 42.5 N) in properly air-entrained concrete did not influence significantly the internal frost resistance F200 - a decrease of the compressive strength after 200 freeze-thaw cycles was in the range from 4 to 12%. The lowest reduction of strength was observed for concrete with CEM I, w/c=0.34 and proper air entrainment. The properly air-entrained concrete layer with exposed aggregate, which was cured with a curing agent with closure capacity > 85%, was characterized by a very good resistance to surface scaling - the mass of scales m56 was equal to 0.10-0.12 kg/m2, irrespective of the type of cement and w/c ratio. However, there was a significant increase in the water absorption rate, surface scaling and chloride permeability, which caused with inadequate curing Keywords: air entrained concrete, curing, durability, exposed aggregate pavement, frost resistance, road pavement, permeability, scaling resistance | | (15p.) |
55. | Levintant Zayonts N., Kwiatkowski L., Swiatek Z., Brzozowska J., Local Pseudoelastic Behaviour and Surface Characteristics of N Ion Implanted NiTi Shape Memory Alloy, ACTA PHYSICA POLONICA A, ISSN: 0587-4246, DOI: 10.12693/APhysPolA.132.210, Vol.132, No.2, pp.210-216, 2017Levintant Zayonts N., Kwiatkowski L., Swiatek Z., Brzozowska J., Local Pseudoelastic Behaviour and Surface Characteristics of N Ion Implanted NiTi Shape Memory Alloy, ACTA PHYSICA POLONICA A, ISSN: 0587-4246, DOI: 10.12693/APhysPolA.132.210, Vol.132, No.2, pp.210-216, 2017Abstract: The main goal of the proposed paper is to present the results of the nitrogen ion implantation effects on mechanical and corrosion properties of NiTi shape memory alloy. Local pseudoelasticity phenomena of NiTi were determined using the ultra-low load applied system. The load–penetration depth curves show that lower nitrogen fluence improves mechanical properties in the near surface layer but higher ion fluence leads to degradation of pseudoelasticity properties. Corrosion resistance of NiTi in the Ringer solution was evaluated by means of electrochemical methods. The results of potentiodynamic measurements in the anodic range for implanted NiTi indicate a decrease of passive current density range in comparison with non-treated NiTi, without any signs related to Ni release. The results of impedance measurements recorded at the corrosion potential show a capacitive behaviour for all samples without clear predominance of one of them. It can be explained by the fact that this result concerns the first stage of corrosion exposition. It is shown that nitrogen ion implantation leads to formation of modified surface of improved physicochemical properties | | (15p.) |
56. | Tauzowski P., Lógó J., Pintér E., Parametric Study on the Element Size Effect for Optimal Topologies, Periodica Polytechnica Civil Engineering, ISSN: 0553-6626, DOI: 10.3311/PPci.0000, pp.1-10, 2017 | | (15p.) |
57. | Ustrzycka A., Mróz Z., Kowalewski Z.L., EXPERIMENTAL ANALYSIS AND MODELLING OF FATIGUE CRACK INITIATION MECHANISMS, JOURNAL OF THEORETICAL AND APPLIED MECHANICS, ISSN: 1429-2955, DOI: 10.15632/jtam-pl.55.4.1443, Vol.55, No.4, pp.1443-1448, 2017Ustrzycka A., Mróz Z., Kowalewski Z.L., EXPERIMENTAL ANALYSIS AND MODELLING OF FATIGUE CRACK INITIATION MECHANISMS, JOURNAL OF THEORETICAL AND APPLIED MECHANICS, ISSN: 1429-2955, DOI: 10.15632/jtam-pl.55.4.1443, Vol.55, No.4, pp.1443-1448, 2017Abstract: The present work is devoted to simulation of fatigue crack initiation for cyclic loading within the nominal elastic regime. It is assumed that damage growth occurs due to action of meanstress and its fluctuations induced by crystalline grain inhomogeneity and the free boundary effect. The macrocrack initiation corresponds to a critical value of accumulated damage. The modelling of damage growth is supported by Electronic Speckle Pattern Interferometry (ESPI) apparatus using coherent laser light. Keywords: fatigue crack initiation, damage evolution, optical methods | | (15p.) |
58. | Będkowski J., Röhling T., Hoeller F., Shulz D., Schneider F.E., Benchmark of 6D SLAM (6D Simultaneous Localisation and Mapping) Algorithms with Robotic Mobile Mapping Systems, Foundations of Computing and Decision Sciences, ISSN: 0867-6356, DOI: 10.1515/fcds-2017-0014, Vol.42, No.3, pp.275-295, 2017Będkowski J., Röhling T., Hoeller F., Shulz D., Schneider F.E., Benchmark of 6D SLAM (6D Simultaneous Localisation and Mapping) Algorithms with Robotic Mobile Mapping Systems, Foundations of Computing and Decision Sciences, ISSN: 0867-6356, DOI: 10.1515/fcds-2017-0014, Vol.42, No.3, pp.275-295, 2017Abstract: This work concerns the study of 6DSLAM algorithms with an application of robotic mobile mapping systems. The architecture of the 6DSLAM algorithm is designed for evaluation of different data registration strategies. The algorithm is composed of the iterative registration component, thus ICP (Iterative Closest Point), ICP (point to projection), ICP with semantic discrimination of points, LS3D (Least Square Surface Matching), NDT (Normal Distribution Transform) can be chosen. Loop closing is based on LUM and LS3D. The main research goal was to investigate the semantic discrimination of measured points that improve the accuracy of final map especially in demanding scenarios such as multi-level maps (e.g., climbing stairs). The parallel programming based nearest neighborhood search implementation such as point to point, point to projection, semantic discrimination of points is used. The 6DSLAM framework is based on modified 3DTK and PCL open source libraries and parallel programming techniques using NVIDIA CUDA. The paper shows experiments that are demonstrating advantages of proposed approach in relation to practical applications. The major added value of presented research is the qualitative and quantitative evaluation based on realistic scenarios including ground truth data obtained by geodetic survey. The research novelty looking from mobile robotics is the evaluation of LS3D algorithm well known in geodesy. Keywords: Mobile robot, Mobile mapping system, Iterative Closest Point, Least Square Surface Matching, Normal Distribution Transform, LUM, 6DSLAM, CUDA | | (15p.) |
59. | Będkowski J., Röhling T., Online 3D LIDAR Monte Carlo localization with GPU acceleration, Industrial Robot: An International Journal, ISSN: 0143-991X, DOI: 10.1108/IR-11-2016-0309, Vol.44, No.4, pp.442-456, 2017Będkowski J., Röhling T., Online 3D LIDAR Monte Carlo localization with GPU acceleration, Industrial Robot: An International Journal, ISSN: 0143-991X, DOI: 10.1108/IR-11-2016-0309, Vol.44, No.4, pp.442-456, 2017Abstract: *Purpose*
This paper aims to focus on real-world mobile systems, and thus propose relevant contribution to the special issue on “Real-world mobile robot systems”. This work on 3D laser semantic mobile mapping and particle filter localization dedicated for robot patrolling urban sites is elaborated with a focus on parallel computing application for semantic mapping and particle filter localization. The real robotic application of patrolling urban sites is the goal; thus, it has been shown that crucial robotic components have reach high Technology Readiness Level (TRL).
*Design/methodology/approach*
Three different robotic platforms equipped with different 3D laser measurement system were compared. Each system provides different data according to the measured distance, density of points and noise; thus, the influence of data into final semantic maps has been compared. The realistic problem is to use these semantic maps for robot localization; thus, the influence of different maps into particle filter localization has been elaborated. A new approach has been proposed for particle filter localization based on 3D semantic information, and thus, the behavior of particle filter in different realistic conditions has been elaborated. The process of using proposed robotic components for patrolling urban site, such as the robot checking geometrical changes of the environment, has been detailed.
*Findings*
The focus on real-world mobile systems requires different points of view for scientific work. This study is focused on robust and reliable solutions that could be integrated with real applications. Thus, new parallel computing approach for semantic mapping and particle filter localization has been proposed. Based on the literature, semantic 3D particle filter localization has not yet been elaborated; thus, innovative solutions for solving this issue have been proposed. Recently, a semantic mapping framework that was already published was developed. For this reason, this study claimed that the authors’ applied studies during real-world trials with such mapping system are added value relevant for this special issue.
*Research limitations/implications*
The main problem is the compromise between computer power and energy consumed by heavy calculations, thus our main focus is to use modern GPGPU, NVIDIA PASCAL parallel processor architecture. Recent advances in GPGPUs shows great potency for mobile robotic applications, thus this study is focused on increasing mapping and localization capabilities by improving the algorithms. Current limitation is related with the number of particles processed by a single processor, and thus achieved performance of 500 particles in real-time is the current limitation. The implication is that multi-GPU architectures for increasing the number of processed particle can be used. Thus, further studies are required.
*Practical implications*
The research focus is related to real-world mobile systems; thus, practical aspects of the work are crucial. The main practical application is semantic mapping that could be used for many robotic applications. The authors claim that their particle filter localization is ready to integrate with real robotic platforms using modern 3D laser measurement system. For this reason, the authors claim that their system can improve existing autonomous robotic platforms. The proposed components can be used for detection of geometrical changes in the scene; thus, many practical functionalities can be applied such as: detection of cars, detection of opened/closed gate, etc. […] These functionalities are crucial elements of the safe and security domain.
*Social implications*
Improvement of safe and security domain is a crucial aspect of modern society. Protecting critical infrastructure plays an important role, thus introducing autonomous mobile platforms capable of supporting human operators of safe and security systems could have a positive impact if viewed from many points of view.
*Originality/value*
This study elaborates the novel approach of particle filter localization based on 3D data and semantic mapping. This original work could have a great impact on the mobile robotics domain, and thus, this study claims that many algorithmic and implementation issues were solved assuming real-task experiments. The originality of this work is influenced by the use of modern advanced robotic systems being a relevant set of technologies for proper evaluation of the proposed approach. Such a combination of experimental hardware and original algorithms and implementation is definitely an added value. Keywords: 3D laser, Monte Carlo localization, Parallel computing, Particle filter localization, Semantic mapping, Unmanned ground vehicle | | (15p.) |
60. | Wencel A., Zakrzewska K.E.^{♦}, Samluk A., Noszczyk B.H., Pijanowska D.G., Pluta K.D., Dried human skin fibroblasts as a new substratum for functional culture of hepatic cells, ACTA BIOCHIMICA POLONICA, ISSN: 0001-527X, DOI: 10.18388/abp.2016_1481, Vol.64, No.2, pp.357-363, 2017Wencel A., Zakrzewska K.E.^{♦}, Samluk A., Noszczyk B.H., Pijanowska D.G., Pluta K.D., Dried human skin fibroblasts as a new substratum for functional culture of hepatic cells, ACTA BIOCHIMICA POLONICA, ISSN: 0001-527X, DOI: 10.18388/abp.2016_1481, Vol.64, No.2, pp.357-363, 2017Abstract: The primary hepatocytes culture is still one of the main challenges in toxicology studies in the drug discovery process, development of in vitro models to study liver function, and cell-based therapies. Isolated hepatocytes display a rapid decline in viability and liver-specific functions including albumin production, conversion of ammonia to urea, and activity of the drug metabolizing enzymes. A number of methods have been developed in order to maintain hepatocytes in their highly differentiated state in vitro. Optimization of culture conditions includes a variety of media formulations and supplements, growth surface coating with the components of extracellular matrix or with synthetic polymers, three-dimensional growth scaffolds and decellularized tissues, and coculture with other cell types required for the normal cell-cell interactions. Here we propose a new substratum for hepatic cells made by drying confluent human skin fibroblasts’ culture. This growth surface coating, prepared using maximally simplified procedure, combines the advantages of the use of extracellular matrices and growth factors/cytokines secreted by the feeder layer cells. In comparison to the hepatoma cells grown on a regular tissue culture plastic, cells cultured on the dried fibroblasts were able to synthesize albumin in larger quantities and to form greater number of apical vacuoles. Unlike the coculture with the living feeder layer cells, the number of cells grown on the new substratum was not reduced after fourteen days of culture. This fact could make the dried fibroblasts coating an ideal candidate for the substrate for non-dividing human hepatocytes. Keywords: cocultures, culture substratum, dried fibroblasts, human skin fibroblasts, C3A cells | | (15p.) |
61. | Jarzębski P., Wiśniewski K., Evaluation of Partial Factorization for Reduction of Finite Element Matrices, ENGINEERING TRANSACTIONS (ROZPRAWY INŻYNIERSKIE), ISSN: 0867-888X, Vol.65, No.1, pp.163-170, 2017Jarzębski P., Wiśniewski K., Evaluation of Partial Factorization for Reduction of Finite Element Matrices, ENGINEERING TRANSACTIONS (ROZPRAWY INŻYNIERSKIE), ISSN: 0867-888X, Vol.65, No.1, pp.163-170, 2017Abstract: In this paper, we present the concept of Partial Factorization [1] and discuss its possible applications to the Finite Element method. We consider: (1) reduction of the element tangent matrix, which is particularly important for mixed/enhanced elements and (2) reduction of the sub-domain matrices of the Domain Decomposition (DD) equation solvers run either sequen-tially on a single machine or in parallel on a cluster of computers. We demonstrate that Partial Factorization can be beneficial for these applications. Keywords: multi-scale models of multi-layer shells, mixed/enhanced finite elements, parallel computing, domain decomposition, solvers | | (15p.) |
62. | Konowrocki R., Walczak S., Influence of Flexibility Parameters of Wheels and Wheelset on the Railway Bogie Dynamics -Experimental and Theoretical Investigations, Machine Dynamics Research, ISSN: 2080-9948, Vol.41, No.4, pp.41-53, 2017Konowrocki R., Walczak S., Influence of Flexibility Parameters of Wheels and Wheelset on the Railway Bogie Dynamics -Experimental and Theoretical Investigations, Machine Dynamics Research, ISSN: 2080-9948, Vol.41, No.4, pp.41-53, 2017Abstract: The paper is devoted to the experimental and theoretical analysis of wheelset elastic properties on the railway vehicle-track interaction. Results of experimental measurements of stiffness components of wheelsets obtained by a new measurement method are shown. Some types of wheelsets are considered with different wheel-disk design. For the theoretical analysis of bending and torsional flexibility of the wheel and wheelset are used. To numerical modeling of the considered wheels and wheelsets models the Finite Element Method (FEM) are applied. Simulation of dynamic interaction between a railway bogie and a curved sector of track in the rigid multibody systems method (VI-Rail software) is modeled. Exemplary simulations results obtained from the bogie-track system model using flexible and rigid model of the wheel and wheelset are presented. Keywords: experimental tests, contact force, measurement, bending wheelset, torsional flexibility wheel | | (14p.) |
63. | Lejkowski W., Dobrowolski A.P., Gawron B., Olszewski R., Wieloaspektowa Analiza Spektralna Sygnałów Fonokardiograficznych , PRZEGLĄD ELEKTROTECHNICZNY, ISSN: 0033-2097, DOI: 10.15199/48.2017.10.17 , Vol.93, No.10, pp.73-76, 2017Lejkowski W., Dobrowolski A.P., Gawron B., Olszewski R., Wieloaspektowa Analiza Spektralna Sygnałów Fonokardiograficznych , PRZEGLĄD ELEKTROTECHNICZNY, ISSN: 0033-2097, DOI: 10.15199/48.2017.10.17 , Vol.93, No.10, pp.73-76, 2017Abstract: W artykule przedstawiono koncepcję analizy spektralnej sygnałów fonokardiograficznych. Zaprezentowano wyniki analizy sygnałów zawierających od kilku do kilkunastu uderzeń serca oraz sygnałów krótkich zawierających pojedyncze uderzenie serca. Przedstawiono propozycje kilkudziesięciu widmowych cech dystynktywnych oraz ocenę ich przydatności w diagnostyce schorzeń kardiologicznych. (Multifaceted Spectral Analysis of Phonocardiographic Signals) Keywords: fonokardiografia, elektrokardiografia, metrologia medyczna, tony serca, analiza spektralna | | (14p.) |
64. | Jóźwiak-Niedźwiedzka D., Gibas K., Glinicki M.A., PETROGRAPHIC IDENTIFICATION OF REACTIVE MINERALS IN DOMESTIC AGGREGATES AND THEIR CLASSIFICATION ACCORDING TO RILEM AND ASTM RECOMMENDATIONS, Roads and Bridges - Drogi i Mosty, ISSN: 1643-1618, DOI: 10.7409/rabdim.017.015, Vol.16, pp.223-239, 2017Jóźwiak-Niedźwiedzka D., Gibas K., Glinicki M.A., PETROGRAPHIC IDENTIFICATION OF REACTIVE MINERALS IN DOMESTIC AGGREGATES AND THEIR CLASSIFICATION ACCORDING TO RILEM AND ASTM RECOMMENDATIONS, Roads and Bridges - Drogi i Mosty, ISSN: 1643-1618, DOI: 10.7409/rabdim.017.015, Vol.16, pp.223-239, 2017Abstract: Considering the long-time durability of concrete in road infrastructure it is important to control the threat of expansive reaction between sodium and potassium hydroxides in the pore solution and the reactive minerals present in the aggregate. Petrographic analysis is the basis for the qualification of aggregates to appropriate classes of reactivity according to ASTM C1778 and RILEM recommendations. This paper presents the results of petrographic analyses of thin sections made from twenty different domestic aggregates. The tested crushed aggregates were obtained from bedrock and glacial deposits. The evaluation of the mineral composition of aggregates included identification of deleterious components and determination of the content of reactive forms of silica. This enabled preliminary classification of aggregate in one of the three classes of reactivity according to RILEM. Obtained results provide an initial assessment of potential reactivity of aggregates and can assist in making decisions to undertake further accelerated or long-term laboratory testing or to modify the concrete mix design. Keywords: aggregate, alkali-aggregate reaction (AAR), petrographic analysis, reactive minerals, thin sections | | (11p.) |
65. | Frąś T.^{♦}, Frąś L.J., Faderl N., RUBBER AND MAGNETORHEOLOGICAL FLUID APPLIED AS THE INTERLAYER IN COMPOSITE ARMOURS AGAINST HIGH-VELOCITY LOADINGS, DIAGNOSTYKA, ISSN: 1641-6414, Vol.18, No.3, pp.63-68, 2017Frąś T.^{♦}, Frąś L.J., Faderl N., RUBBER AND MAGNETORHEOLOGICAL FLUID APPLIED AS THE INTERLAYER IN COMPOSITE ARMOURS AGAINST HIGH-VELOCITY LOADINGS, DIAGNOSTYKA, ISSN: 1641-6414, Vol.18, No.3, pp.63-68, 2017Abstract: Monolithic, homogenous ballistic shields consisting of a single thick, high-hardness and high-strength steel plate are rarely applied in modern combat vehicles. Currently, a popular armour concept is a multilayered shield since it is expected that the kinetic energy of a threat may be dissipated by transmission through materials with different properties and also by multiple interface reflections. Searching for a maximum ballistic protection at minimum weight inspires applications of various materials which complementary behaviour provides a high protective efficiency without excessive mass. The preliminary experimental investigation presented in the paper aimed to verify behaviour of two prototyped laminated armours under impacts of small-calibre projectiles (cal. 7.62). The main interest lied in impact properties of materials proposed as the intermediate layer. The first tested concept was a laminated steel armour with the 10 mm thick rubber interlayer. In the second armour, the intermediate layer consisted of a magnetorheological fluid. Keywords: energy absorption, rubber, magnetorheological fluid, protective properties | | (11p.) |
66. | Widłaszewski J., Nowak M., Nowak Z., Kurp P., Laser-assisted forming of thin-walled profiles, Metal Forming, ISSN: 0867-2628, Vol.XXVIII, No.3, pp.183-198, 2017Widłaszewski J., Nowak M., Nowak Z., Kurp P., Laser-assisted forming of thin-walled profiles, Metal Forming, ISSN: 0867-2628, Vol.XXVIII, No.3, pp.183-198, 2017Abstract: Forming processes assisted by localised laser heating are studied in recent years. Heating is used to make it possible or facilitate forming of materials, which exhibit such adverse properties as: brittleness, effects of high work-hardening or a high elastic springback. The hereby presented investigations concern the hybrid thermo-mechanical forming of thin-walled parts using local heating of the material by the laser beam. The research is aimed at forming of parts from materials used in the aviation industry, such as the nickel-base super-alloys Inconel 625, Inconel 718, and also martensitic superalloys AISI 410 and AISI 325. Preliminary investigations are conducted using X5CrNil8-10 (1.4301) stainless steel. Experimental study and numerical simulations cover the behaviour of thin beams 1 mm thick, subjected to mechanical load in the cantilever arrangement and heated by the CO2 laser beam moving from the free end of the sample towards its fixture. The possibility of obtaining large bending deformations relatively easily due to the application of laser beam is demonstrated experimentally. Experimentally verified finite element numerical simulations show the intense plastic flow of the material layer heated by the laser beam. It is accompanied by a shift of the cross-section neutral axis of the beam. Bending of thin-walled tubes in a specially designed device is studied in the next step. It allows introducing mechanical loading in a controlled manner, heating the material by a moving laser beam and forcing the required deformation according to the kinematic scheme of the device. Keywords: laser-assisted forming, finite element method, thin-walled structure | | (10p.) |
67. | Rowiński P.M., Burczyński T., Duszyński J., Rychard A., Uniwersytet badawczy, czyli…?, NAUKA, ISSN: 1231-8515, Vol.3, pp.35-56, 2017 | | (10p.) |
68. | Kukla D., Szwed M., Roskosz M., Ocena grubości warstw chromowych na stali i staliwie z wykorzystaniem metody prądów wirowych, PRZEGLĄD SPAWALNICTWA, ISSN: 0033-2364, Vol.89, No.11, pp.1-6, 2017Kukla D., Szwed M., Roskosz M., Ocena grubości warstw chromowych na stali i staliwie z wykorzystaniem metody prądów wirowych, PRZEGLĄD SPAWALNICTWA, ISSN: 0033-2364, Vol.89, No.11, pp.1-6, 2017Abstract: W ramach niniejszej pracy opracowano procedurę nieniszczącą, ilościowej oceny grubości warstw chromowych. Do tego celu wykorzystano metodę prądów wirowych, w zakresie analizy fazoczułej, czyli oceny zmian kąta fazowego impedancji w funkcji grubości warstwy. Taka analiza stosowana jest w przypadku pomiarów grubości warstw konduktywnych w zakresie grubości od kilku do kilkuset mikrometrów, wytworzonych na podłożu konduktywnym. Celem właściwej kalibracji parametrów pomiaru, zaprojektowano i wykonano po dwa zestawy próbek referencyjnych z warstwami chromowymi o grubości 15, 30 i 45 μm na podłożu ze stali stopowej 15HM oraz na staliwie węglowym L-200. Z obydwu zestawów próbek pobrano wycinki do badań metalograficznych, które pozwoliły na bezpośredni pomiar grubości warstwy na przygotowanych zgładach. Wyniki tych pomiarów potraktowano jako wartości referencyjne do dalszych badań. Warstwy chromowe uzyskano w procesie nakładania chromu technicznego metodą galwaniczną, przy parametrach zapewniających uzyskanie założonych grubości. Otrzymane wyniki pozwoliły potwierdzić możliwość ilościowej oceny warstw chromowych z dokładnością do 5 μm, z zastosowaniem komercyjnego urządzenia defektoskopowego przeznaczonego do badań metodą prądów wirowych Keywords: warstwy chromowe, pomiar grubości, prądy wirowe | | (9p.) |
69. | Fryczowski K., Roskosz M., Kukla D., Szwed M., Wykorzystanie szumu Barkhausena w ocenie twardości warstw nawęglanych oraz hartowanych indukcyjnie na stali AMS 6414, PRZEGLĄD SPAWALNICTWA, ISSN: 0033-2364, Vol.89, No.11, pp.1-6, 2017Fryczowski K., Roskosz M., Kukla D., Szwed M., Wykorzystanie szumu Barkhausena w ocenie twardości warstw nawęglanych oraz hartowanych indukcyjnie na stali AMS 6414, PRZEGLĄD SPAWALNICTWA, ISSN: 0033-2364, Vol.89, No.11, pp.1-6, 2017Abstract: Analizowano możliwości określenia zmian twardości warstw nawęglanych i hartowanych indukcyjnie na podstawie wielkości ilościowo opisujących szum Barkhausena. Badania przeprowadzono na zestawie trzech próbek o stałej grubości warstwy nawęglanej (1,2 mm) o różnych wartościach twardości. Pomiary przeprowadzono dla trzech konfiguracji aparatury MEB-4C Mag-Lab s.c. różniących się częstotliwością prądu magnesującego. Analizowano obwiednię szumu Barkhausena i jej punkty charakterystyczne, energię, RMS, periodogramy FFT oraz rozkłady liczby zdarzeń. Uzyskano interesujące korelacje diagnostyczne mogące posłużyć w rozwiązywaniu zagadnień odwrotnych badań nieniszczących Keywords: twardość, szum Barkhausena, zagadnienie odwrotne | | (9p.) |
70. | Brzozowski Bartosz, Kawka Karol, Kaźmierczak Krzysztof, Rochala Zdzisław, Wojtowicz Konrad, Supporting the Process of Aircraft Maintenance with Mobile Devices, Transactions of the INSTITUTE of AVIATION, ISSN: 0509-6669, No.2(247), pp.7-18, 2017Brzozowski Bartosz, Kawka Karol, Kaźmierczak Krzysztof, Rochala Zdzisław, Wojtowicz Konrad, Supporting the Process of Aircraft Maintenance with Mobile Devices, Transactions of the INSTITUTE of AVIATION, ISSN: 0509-6669, No.2(247), pp.7-18, 2017Abstract: Maintenance of aircraft is a complex process and therefore, in order to optimize the process, integrated information systems are increasingly used. Rapid development and wide availability of mobile devices equipped with powerful processors and with a wide range of modern communication connections suggests their high usability for enterprise IT systems. In the Department of Avionics and Air Armament of the Military University of Technology (WAT) an ERP-class (Enterprise Resource Planning) system, intended to support aircraft maintenance [4] has been designed and developed. The main concept of the system is to store the aircraft related and maintenance information in a central repository, i.e. in databases hosted on a central database server. This solution ensures concurrent availability of the data to a large group of authorized users. The key components of the system include the database server and client applications, which ensure access to centralized information resources, according to assigned user rights. The project involves development of client applications using three technologies: web, desktop and mobile one. Developed client applications have successfully passed integration tests performed using sample maintenance data. Currently works on user authorization security and wireless data security are under way. Keywords: maintenance system, mobile application, aircraft | | (9p.) |
71. | Glinicki M.A., Brandt A.M., Dąbrowski M., Gibas K., Jaskulski R., Jóźwiak-Niedźwiedzka D., Baran T., Gryziński M., Ładyżyński K., Nowowiejski G.^{♦}, Beton osłonowy w konstrukcjach narażonych na promieniowanie jonizujące, INŻYNIERIA I BUDOWNICTWO, ISSN: 0021-0315, Vol.12, pp.637-643, 2017Glinicki M.A., Brandt A.M., Dąbrowski M., Gibas K., Jaskulski R., Jóźwiak-Niedźwiedzka D., Baran T., Gryziński M., Ładyżyński K., Nowowiejski G.^{♦}, Beton osłonowy w konstrukcjach narażonych na promieniowanie jonizujące, INŻYNIERIA I BUDOWNICTWO, ISSN: 0021-0315, Vol.12, pp.637-643, 2017Abstract: W artykule opisano podstawowe wyniki uzyskane w trakcie realizacji projektu badawczego „Trwałość i skuteczność betonowych osłon przed promieniowaniem jonizującym w obiektach energetyki jądrowej” [1]. Przedstawiono też wytyczne techniczne i kryteria oceny betonu osłonowego. Uzyskane wyniki mogą stanowić podstawę dalszych prac przy projektowaniu obiektów elektrowni jądrowych, składowisk materiałów radioaktywnych i innych miejsc powstawania, stosowania lub przechowywania materiałów wytwarzających promieniowanie jonizujące. Artykuł obejmuje zagadnienia związane z wymaganą skutecznością betonowych konstrukcji osłonowych przez zapewnienie bezpieczeństwa personelu i otoczenia przed oddziaływaniem promieniowania jonizującego. Rozpatrzono również trwałość osłon betonowych, tzn. zachowanie właściwości mechanicznych i nieprzepuszczalności w okresie przewidzianej eksploatacji pod wpływem przewidywanych oddziaływań zewnętrznych i procesów starzenia, a także przy podwyższonej temperaturze i promieniowaniu jonizującym. Artykuł nie obejmuje zagadnień integralności osłon pod obciążeniami wyjątkowymi, spowodowanymi awarią reaktora, uderzeniem samolotu, działaniami terrorystycznymi itp. | | (7p.) |
72. | Majka K., Krupienicz A., Olszewski R., Telepielęgniarstwo w ortopedii, Medycyna Ogólna i Nauki o Zdrowiu, ISSN: 2083-4543, DOI: 10.26444/monz/75509, Vol.23, No.2, pp.94-97, 2017Majka K., Krupienicz A., Olszewski R., Telepielęgniarstwo w ortopedii, Medycyna Ogólna i Nauki o Zdrowiu, ISSN: 2083-4543, DOI: 10.26444/monz/75509, Vol.23, No.2, pp.94-97, 2017Abstract: Wprowadzenie i cel pracy. Rozwój technologii informacyjno-komunikacyjnej może doprowadzić do poprawy sytuacji w służbie zdrowia. Telepielęgniarstwo pozwoli na rozszerzenie praktyki pielęgniarskiej oraz wielu funkcji takich jak: opiekuńczo-pielęgnacyjna, profilaktyczna, diagnostyczna, rehabilitacyjna i związana z promocją zdrowia. Celem pracy jest ukazanie telepielęgniarstwa w ortopedii, a także zaprezentowanie wielu korzyści, jakie niesie zarówno dla pacjenta, jak i dla personelu medycznego. Skrócony opis stanu wiedzy. Starzejące się społeczeństwo potrzebuje zarówno wykwalifikowanego personelu pielęgniarskiego, jak i możliwości uzyskania szybkiej konsultacji lekarskiej i pielęgniarskiej. Udzielanie wskazówek, porad i opieki pielęgniarskiej przez pielęgniarki specjalistki w swej profesji m.in. za pomocą wideokonferencji przysporzy znaczących korzyści zarówno pacjentom, lekarzom, pielęgniarkom, jak i rehabilitantom. Podsumowanie. Wdrożenie wirtualnych wizyt może doprowadzić do poprawy sytuacji w ochronie zdrowia. Telepielęgniarstwo rozszerzyłoby kompetencje pielęgniarki, a także podniosłoby jakość świadczonych przez nie usług. Być może zatrzymałoby również emigrację zarobkową pielęgniarek w Polsce. Keywords: telepielęgniarstwo, ortopedia, edukacja pacjenta, nowe technologie, kształcenie, niedobór personelu pielęgniarskiego
| | (6p.) |
73. | Duszyński J., Burczyński T., Rowiński P.M., Rychard A., Projekt: Uniwersytet PAN , Nauka i Szkolnictwo Wyższe, ISSN: 1231-0298, Vol.2, No.50, pp.59-76, 2017Duszyński J., Burczyński T., Rowiński P.M., Rychard A., Projekt: Uniwersytet PAN , Nauka i Szkolnictwo Wyższe, ISSN: 1231-0298, Vol.2, No.50, pp.59-76, 2017Abstract: Instytuty Polskiej Akademii Nauk mają wśród polskich instytucji naukowych czołowy
potencjał merytoryczny. W instytutach PAN w latach 2013-2016 powstało 19,7% prac afiliowanych
w polskich instytucjach i umieszczonych w najbardziej prestiżowych pismach naukowych
danych dziedzin (górne 10% z list pism danej dziedziny nauki uszeregowanych według rosnącego
współczynnika wpływu, IF). Jest to najlepszy wynik wśród polskich instytucji akademickich. Kadra
instytutów PAN zajmuje się nie tylko badaniami, ale też dydaktyką; 1607 osób (stan na 31 grudnia
2016) było na stacjonarnych studiach doktoranckich w Instytutach PAN. Stopień umiędzynarodowienia
studiów w PAN (8%) jest największy wśród polskich uczelni. W związku z tym uzasadnione
wydaje się powołanie Uniwersytetu PAN (UPAN), który mógłby stać się pierwszą w Polsce uczelnią
badawczą. Planuje się, że docelowo kształciłoby się na nim 2,5 tys. osób, w przeważającej części studentek
i studentów III stopnia. Taka liczba pozwoli na zagwarantowanie indywidualnej merytorycznej
opieki każdemu studentowi, a także na wprowadzenie i przetestowanie nowatorskich programów
dydaktycznych, właściwych erze Internetu i e-learningu, prowadzenia studiów online poprzez
courser, studiów inter- i crossdyscyplinarnych. UPAN ma realne szanse stać się wizytówką polskiej
nauki i szkolnictwa wyższego, gdyż otwarte, międzynarodowe wieloletnie programy konkursowe na
pozycje: wizytujących profesorów, stażystów podoktorskich i doktorantów mogą podnieść umiędzynarodowienie
zarówno kadry, jak i studentów UPAN do poziomu właściwego najlepszym uczelniom
świata. Z uwagi na wielkość naszego budżetu nauki i szkolnictwa wyższego osiągnięcie takiego umiędzynarodowienia
jest finansowo realne w najbliższym czasie tylko dla uczelni tak małej jak UPAN.
Opisane działania będą projakościowe także dla samych instytutów PAN i istotnie podniosą ich poziom
merytoryczny. Po kilku latach UPAN ma realne szanse na uplasowanie się w międzynarodowych
rankingach na bardzo dobrych pozycjach, w pierwszej dwusetce, a nawet w pierwszej setce
najlepszych światowych uczelni. Należy podkreślić, że warunkiem tego jest zapewnienie finansowania
badań w instytutach PAN na co najmniej takim jak obecnie poziomie, uelastycznienie ich sieci, wytworzenie mechanizmów synergii pomiędzy instytutami (wspólny cel – UPAN) oraz wsparcie tego
projektu długoletnim programem umiędzynarodowienia kadry i studentów. Keywords: research university, University of the Polish Academy of Sciences, excellence in science | | (6p.) |
74. | Makowska K., Kowalewski Z.L., Ziółkowski P., Badur J., Ocena stopnia uszkodzenia eksploatowanych łopatek turbiny z wykorzystaniem sygnału szumu Barkhausena, ENERGETYKA, PROBLEMY ENERGETYKI I GOSPODARKI PALIWOWO-ENERGETYCZNEJ, ISSN: 0013-7294, Vol.760, No.10, pp.638-641, 2017 | | (4p.) |
75. | Szymczak T., Kowalewski Z.L., WYBRANE MATERIAŁY STOSOWANE W UKŁADACH HAMULCOWYCH I ICH WŁAŚCIWOŚCI MECHANICZNE, TRANSPORT SAMOCHODOWY, ISSN: 1731-2795, Vol.2, pp.87-99, 2017Szymczak T., Kowalewski Z.L., WYBRANE MATERIAŁY STOSOWANE W UKŁADACH HAMULCOWYCH I ICH WŁAŚCIWOŚCI MECHANICZNE, TRANSPORT SAMOCHODOWY, ISSN: 1731-2795, Vol.2, pp.87-99, 2017Abstract: W pracy omówiono wybrane materiały stosowane w układach hamulcowych, jak: żeliwo szare, kompozyty ceramiczne oraz metalowe o osnowie ze stopu aluminium. Zaprezentowano ich zasadnicze właściwości mechaniczne oraz parametry fizyczne. Ponadto, omówiono zmiany granicy plastyczności i wytrzymałości doraźnej żeliwa szarego w warunkach rozciągania prowadzonego przy dziewięciu poziomach temperatury w zakresie od 20 °C do 700 °C | | (3p.) |
76. | Olaszek P., Świercz A., Wyczałek I., Kołakowski P., Szadkowski K., Moduł pomiaru i oceny odpowiedzi eksploatowanych kolejowych konstrukcji mostowych, Mosty, ISSN: 1896-7663, Vol.3-4, pp.22-26, 2017 | | (3p.) |
77. | Wasilewski M., Pisarski D., Konowrocki R., Bajer C.I., New efficient adaptive control of torsional vibrations induced by sudden nonlinear disturbances, CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), pp.1-2, 2017Wasilewski M., Pisarski D., Konowrocki R., Bajer C.I., New efficient adaptive control of torsional vibrations induced by sudden nonlinear disturbances, CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), pp.1-2, 2017Abstract: The aim of this paper is to present a novel adaptive technique of control of the vibrating drilling systems. The algorithm constitutes an adaptive linear quadratic regulator that uses direct measurements of the disturbance to synthesize its linear dynamic approximation. This approach allows generating control law that includes the impact of the friction on the system dynamics and optimally steers the system to the desired trajectory. The effectiveness of the algorithm is validated via comprehensive numerical simulations of the control of the simplified drilling model. The results are compared to these obtained with the use of the Linear Quadratic Gaussian regulator. Keywords: vibration control, drillstring, adaptive control, auto-regressive model | |
78. | Lumelskyj D., Rojek J., Banabic D., Lazarescu L., Detection of Strain Localization in Nakazima Formability Test - Experimental Research and Numerical Simulation, SHEMET17, 17th International Conference on Sheet Metal, 2017-04-10/04-12, Palermo (IT), DOI: 10.1016/j.proeng.2017.04.016, No.183, pp.89-94, 2017Lumelskyj D., Rojek J., Banabic D., Lazarescu L., Detection of Strain Localization in Nakazima Formability Test - Experimental Research and Numerical Simulation, SHEMET17, 17th International Conference on Sheet Metal, 2017-04-10/04-12, Palermo (IT), DOI: 10.1016/j.proeng.2017.04.016, No.183, pp.89-94, 2017Abstract: This paper presents the investigation on detection of strain localization in experimental research and numerical simulation of sheet metal forming. Experimental tests and numerical simulations of the Nakazima test have been performed for the DC04 grade steel sheet. The onset of localized necking has been determined using the criterion based on analysis of the major principal strain and its first and second time derivatives in the most strained zone. The strain localization has been evaluated by the maximum of strain acceleration which corresponds to the inflection point of the strain velocity vs. time. The limit strains have been calculated numerically and experimentally for specimens undergoing deformation at different strain paths. It has been shown that the numerical model predicts formability limits close to the experimental results. Analyzed criterion can be used as a potential alternative tool to determine formability in standard finite element simulations of sheet forming processes. Keywords: sheet forming, formability, forming limit curve, numerical simulation | |
79. | Jurczak G., Maździarz M., Dłużewski P., Finite element modelling of threading dislocation effect on GaN/AlN quantum dot, ICMM5, 5th International Conference on Material Modeling, 2017-06-14/06-16, Rome (IT), pp.1-1, 2017Jurczak G., Maździarz M., Dłużewski P., Finite element modelling of threading dislocation effect on GaN/AlN quantum dot, ICMM5, 5th International Conference on Material Modeling, 2017-06-14/06-16, Rome (IT), pp.1-1, 2017Keywords: Quantum dot, Threading dislocation, Piezoelectricity, Finite element modelling | |
80. | Wawrzyk K., Nosewicz S., Rojek J., Kowalczyk P., A constitutive model and numerical simulation of sintering processes at macroscopic level, CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), pp.MS02-13-MS02-14, 2017Wawrzyk K., Nosewicz S., Rojek J., Kowalczyk P., A constitutive model and numerical simulation of sintering processes at macroscopic level, CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), pp.MS02-13-MS02-14, 2017Abstract: This document presents modelling of single-phase powder sintering processes at the macroscopic level. In particular, its constitutive formulation, numerical implementation and numerical test are described. Numerical tests were carried out for a cylindrical specimen under hydrostatic and uniaxial pressure. Results of macroscopic analysis are compared against the microscopic model results. Keywords: sintering porcesses, numerical analysis, multiscale modelling | |
81. | Rojek J., Zubelewicz A., Madan N., Nosewicz S., New formulation of the discrete element method, CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), pp.MS13-27-MS13-28, 2017Rojek J., Zubelewicz A., Madan N., Nosewicz S., New formulation of the discrete element method, CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), pp.MS13-27-MS13-28, 2017Abstract: This work presents a new original formulation of the discrete element method based on the soft contact approach. The standard DEM has been enhanced by introduction of the additional (global) deformation mode caused by the stresses in the particles induced by the contact forces. Uniform stresses and strains are assumed for each particle. The stresses are calculated from the contact forces. The strains are obtained using an inverse constitutive relationship. The strains allow us to obtain deformed particle shapes. The deformed shapes (ellipses) are taken into account in contact detection and evaluation of the contact forces. The numerical example shows that a particle deformation changes the particle interaction and the distribution of forces in the discrete element assembly. Keywords: discrete element method; deformable particles; soft contact | |
82. | Mrozek A., Kuś W., Burczyński T., Modelling of molybdenum-based 2D materials , CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), pp.MS14-27-MS14-28, 2017Mrozek A., Kuś W., Burczyński T., Modelling of molybdenum-based 2D materials , CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), pp.MS14-27-MS14-28, 2017Abstract: The flat, two dimensional materials play important role in the research and industrial applications in the last 15 years. The new materials with flat atomic structures are discovered every month. The focus of the paper is on the modelling of the single layer molybdenum disulphide based material. The numerical simulations and mechanical material properties are described and discussed. Keywords: molybdenum, two dimensional materials, molecular modelling, MoS2 | |
83. | Leyva-Mendivil M.F., Lengiewicz J., Page A., Bressloff N.W., Limbert G., Implications of Multi-asperity Contact for Shear Stress Distribution in the Viable Epidermis – An Image-based Finite Element Study, BIOTRIBOLOGY, ISSN: 2352-5738, DOI: 10.1016/j.biotri.2017.04.001, Vol.11, pp.110-123, 2017Leyva-Mendivil M.F., Lengiewicz J., Page A., Bressloff N.W., Limbert G., Implications of Multi-asperity Contact for Shear Stress Distribution in the Viable Epidermis – An Image-based Finite Element Study, BIOTRIBOLOGY, ISSN: 2352-5738, DOI: 10.1016/j.biotri.2017.04.001, Vol.11, pp.110-123, 2017Abstract: Understanding load transfer mechanisms from the surface of the skin to its deeper layers is crucial in gaining a fundamental insight into damage phenomena related to skin tears, blisters and superficial/deep tissue ulcers. It is unknown how shear stresses in the viable epidermis are conditioned by the skin surface topography and internal microstructure and to which extent their propagation is conditioned by the size of a contacting asperities. In this computational study, these questions were addressed by conducting a series of contact finite element analyses simulating normal indentation of an anatomically-based two-dimensional multi-layer model of the skin by rigid indenters of various sizes and sliding of these indenters over the skin surface. Indentation depths, local (i.e. microscopic) coefficients of friction and Young's modulus of the stratum corneum were also varied. For comparison purpose and for isolating effects arising purely from the skin microstructure, a geometrically-idealised equivalent multi-layer model of the skin was also considered. The multi-asperity contact induced by the skin topographic features in combination with a non-idealised geometry of the skin layers lead to levels of shear stresses much higher than those produced in the geometrically-idealised case. These effects are also modulated by other system parameters (e.g. local coefficient of friction, indenter radius). These findings have major implications for the design and analyses of finite element studies aiming at modelling the tribology of skin, particularly if the focus is on how surface shear stress leads to damage initiation which is a process known to occur across several length scales. Keywords: Skin, Microstructure, Contact mechanics, Indentation, Sliding contact, Finite element, Image-based modelling, Material properties | |
84. | Szolc T., Konowrocki R., Pochanke A., Michajłow M., Dynamic aspects of design and maintenance of the rotating machinery applied in the mining industry, MEC-2017, MINERAL ENGINEERING CONFERENCE, 2017-09-20/09-23, Wisła (PL), No.2, pp.14-15, 2017Szolc T., Konowrocki R., Pochanke A., Michajłow M., Dynamic aspects of design and maintenance of the rotating machinery applied in the mining industry, MEC-2017, MINERAL ENGINEERING CONFERENCE, 2017-09-20/09-23, Wisła (PL), No.2, pp.14-15, 2017Abstract: In the paper a dynamic behaviour of the selected typical group of rotating machines applied in the mining industry is investigated. These are the beater mills and crushers as well as blowers and compressors, all driven by the asynchronous motors. In particular, there is considered an influence of various types of machine working tool loadings on the system lateral steady-state dynamic responses as well as a mutual torsional electromechanical interaction between the driving motor and the driven machine in transient operational conditions. The theoretical calculations have been performed by means of the advanced structural mechanical models. The conclusions drawn from computational results can be very useful during design phase of these devices as well as helpful for their users during regular maintenance. Keywords: rotating mill machinery, electric motor interaction, electromechanical model, torsion vibration | |
85. | Pisarski D., Myśliński A., Online adaptive semi-active vibration damping of slender structures subject to moving loads, ICOEV2017, International Conference on Engineering Vibration, 2017-09-04/09-07, Sofia (BG), pp.1, 2017Pisarski D., Myśliński A., Online adaptive semi-active vibration damping of slender structures subject to moving loads, ICOEV2017, International Conference on Engineering Vibration, 2017-09-04/09-07, Sofia (BG), pp.1, 2017Abstract: In this paper, the problem of the optimal control of a structure subjected to a moving load has been studied. In contrast to the previous works of the authors, focused on open-loop strategies, this paper has been devoted to an adaptive closed-loop control, where the switched damping strategy is subject to real-time adaptation according to the measured speed of the moving load.
The proposed adaptive controller has been designed based on the use of the reference optimal solutions computed for a given constant velocity and a set of functions describing the sensitivity of the system dynamics to a change in the speed and the initial state. All these data are pre-computed offline and stored in the controller's memory. As a result, the online computational algorithm, based on a simple gradient descent loop, uses a minimal calculation effort. This allows almost immediate updating of the optimal controls, even with the use of a standard PC. The method has been validated by means of numerical experiments carried out for a wide range of the velocity perturbation scenarios. The proposed scheme is general for a class of time-varying bilinear control systems and can be implemented to a wide range of problems concerned with smart structural elements. | |
86. | Mackiewicz S., PODSTAWOWE ZASADY PRZEPROWADZANIA EKSPOZYCJI RADIOGRAFICZNYCH NA PANELACH PŁASKICH, Stary Młyn 2017, KRAJOWA KONFERENCJA BADAŃ RADIOGRAFICZNYCH, 2017-09-04/09-06, Bolesławiec k/Wieruszowa (PL), pp.15-26, 2017 | |
87. | Mackiewicz S., Detektory promieniowania stosowane w cyfrowej radiografii bezpośredniej, BADANIA NIENISZCZĄCE I DIAGNOSTYKA, ISSN: 2451-4462, Vol.1-2, pp.44-51, 2017Mackiewicz S., Detektory promieniowania stosowane w cyfrowej radiografii bezpośredniej, BADANIA NIENISZCZĄCE I DIAGNOSTYKA, ISSN: 2451-4462, Vol.1-2, pp.44-51, 2017Abstract: W artykule opisano podstawy działania detektorów promieniowania stosowanych w cyfrowej radiografii bezpośredniej - DR . Scharakteryzowano rożne rodzaje paneli płaskich pod kątem ich przydatności w obszarze badań nieniszczących. W sposób bardziej szczegółowy omówiono panele płaskie z przemianą pośrednią oparte na matrycy a-Si z tranzystorami TFT, które wykazują obecnie największą przydatność do zastosowań w badaniach nieniszczących. Przeanalizowano najważniejsze parametry paneli płaskich w aspekcie ich zastosowań do badań złączy spawanych oraz innych wyrobów i elementów badanych dotychczas tradycyjną metodą radiograficzną Keywords: radiografia cyfrowa, panele płaskie, radiografia bezpośrednia DR | |
88. | Pisarski D., Szmidt T., Semi-Active Stabilization of Pipe Discharging Air With Electromagnetic Devices of Motional Type, ICAST2017, The 28th International Conference on Adaptive Structures and Technologies, 2017-10-08/10-11, Kraków (PL), pp.1-1, 2017Pisarski D., Szmidt T., Semi-Active Stabilization of Pipe Discharging Air With Electromagnetic Devices of Motional Type, ICAST2017, The 28th International Conference on Adaptive Structures and Technologies, 2017-10-08/10-11, Kraków (PL), pp.1-1, 2017Abstract: The study deals with a problem of applying electromagnetic devices of motional type to improve the dynamic stability of a pipe conveying air. When the flow velocity reaches its critical value the steady equilibrium position becomes unstable, and self-excited lateral vibrations arise. Electromagnetic devices of another – transformer – type demonstrated to have been highly effective in the passive stabilization of such system as well as active stabilization of similar non-conservative system with a follower force. In the present work, we apply a pair of motional devices made of a conducting plate which is attached to the pipe and moves together with it within the perpendicular magnetic field generated by the controlled electromagnets. This motion generates eddy currents in the plates and a drag force of a viscous character. Under this setting, we firstly investigate the possibility of designing a stabilizing control within the magnetic field’s region where every passive solution results in an unstable or conservative state. For that purpose, we constitute a practical condition justifying the existence of a stabilizing control for a given set of system parameters. Later we pose and solve an optimal control problem aiming at stabilizing the system with the optimal rates of decrease of the system’s energy. The solution is examined by means of numerical simulations performed within the three regions of the flow velocity: low subcritical where the Coriolis acceleration of the conveyed fluid generates the predominate damping force, high subcritical where the inertia of the fluid begins to dominate dynamics of the system, and low supercritical where unstable flutter vibrations start to arise. The effectiveness of the designed optimal controller is validated by comparisons with the corresponding passive solutions. | |
89. | Długosz A., Pokorska I., Glinicki M.A., Jaskulski R., Identification of thermal properties of hardening concrete by means of evolutionary algorithms, ECCOMAS - IPM 2017, 4th International Conference on Inverse Problems in Mechanics of Structures and Materials, 2017-05-31/06-02, Rzeszów - Krasiczyn (PL), pp.17-18, 2017 | |
90. | Kurtis K.E., Xi Y., Glinicki M.A., Provis J., Giannini E.R., Fu T., Can We Design Concrete to Survive Nuclear Environments?, CONCRETE INTERNATIONAL, ISSN: 0162-4075, Vol.39, No.11, pp.53-59, 2017 | |
91. | Nowak Z., Nowak M., Widłaszewski J., Kurp P., Experimental and numerical investigation on laser-assisted bending of pre-loaded metal plate, CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), No.MS13, pp.37-38, 2017Nowak Z., Nowak M., Widłaszewski J., Kurp P., Experimental and numerical investigation on laser-assisted bending of pre-loaded metal plate, CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), No.MS13, pp.37-38, 2017Abstract: The laser forming technique has an important disadvantage, which is the limitation of plastic deformation generated by a single laser beam pass. In order to increase the plastic deformation one has to repeat the process several times or use the alternative method. To increase the plastic deformation it is possible to add external forces during the laser forming process. In this paper, we investigate the influence of external pre-loads on the laser bending of steel plate. The pre-loads investigated generate bending towards the laser beam. The thermal, elastic-plastic analysis is performed using the commercial nonlinear finite element analysis package ABAQUS. The focus of the paper is to identify how this pattern of the pre-load influence the final bend angle of the plate. Keywords: laser forming, force-assisted laser bending, thermo-mechanical simulations, FEA | |
92. | Szolc T., Konowrocki R., Pochanke A., Michajłow M., Dynamic aspects of design and maintenance of the rotating machinery applied by the mining industry , MEC-2017, MINERAL ENGINEERING CONFERENCE, 2017-09-20/09-23, Wisła (PL), DOI: 10.1051/e3sconf/201712301010, No.18, 01010, pp.1-10, 2017Szolc T., Konowrocki R., Pochanke A., Michajłow M., Dynamic aspects of design and maintenance of the rotating machinery applied by the mining industry , MEC-2017, MINERAL ENGINEERING CONFERENCE, 2017-09-20/09-23, Wisła (PL), DOI: 10.1051/e3sconf/201712301010, No.18, 01010, pp.1-10, 2017Abstract: In the paper a dynamic behaviour of the selected typical group of rotating machines applied in the mining industry is investigated. These are the beater mills and crushers as well as blowers and compressors, all driven by the asynchronous motors. In particular, there is considered an influence of various types of machine working tool loadings on the system lateral steady-state dynamic responses as well as a mutual torsional electromechanical interaction between the driving motor and the driven machine in transient operational conditions. The theoretical calculations have been performed by means of the advanced structural mechanical models. The conclusions drawn from computational results can be very useful during design phase of these devices as well as helpful for their users during regular maintenance. Keywords: mining industry, electromechanic coupling, design and maintenance of mill, torsional vibrations | |
93. | Katz T., SPRAWDZANIE I WERYFIKACJA KLASYCZNYCH DEFEKTOSKOPÓW ULTRADŹWIĘKOWYCH, XXIII Seminarium NIENISZCZĄCE BADANIA MATERIAŁÓW, 2017-03-15/03-17, Zakopane (PL), pp.161-169, 2017 | |
94. | Katz T., Characterization and verification of ultrasonic flaw detector, 46. KKBN, 46. Krajowa Konferencja Badań Nieniszczących, 2017-10-17/10-19, Starachowice (PL), pp.29-32, 2017Katz T., Characterization and verification of ultrasonic flaw detector, 46. KKBN, 46. Krajowa Konferencja Badań Nieniszczących, 2017-10-17/10-19, Starachowice (PL), pp.29-32, 2017Abstract: The purpose of this article is to present the most important requirements and problems related to periodic inspection of ultrasonic flaw detectors in accordance with requirements of standard PN-EN12668-1: 2010. Particular attention has been paid to the measurement of ultrasonic flaw detector parameters and requirements concerning specialist measuring equipment. The form of ultrasonic flaw detector certificate was proposed, which specifies all tests of group 2 of PN-EN12668-1: 2010. The proposed certificate confirms the compatibility of the flaw detector with the specified standard and the test group under which the equipment was tested. Keywords: characterization, verification, calibration, flaw, detector | |
95. | Golasiński K.M., Pieczyska E., Detsch R., Boccaccini A.R., Takesue N., Evaluation of mechanical properties and biocompatibility of Gum Metal for implant applications, 7th KMM-VIN Industrial Workshop “Biomaterials: Key Technologies for Better Healthcare”, 2017-09-27/09-28, Erlangen (DE), pp.46-46, 2017Golasiński K.M., Pieczyska E., Detsch R., Boccaccini A.R., Takesue N., Evaluation of mechanical properties and biocompatibility of Gum Metal for implant applications, 7th KMM-VIN Industrial Workshop “Biomaterials: Key Technologies for Better Healthcare”, 2017-09-27/09-28, Erlangen (DE), pp.46-46, 2017Abstract: In this work, mechanical properties of a β-Ti alloy Gum Metal (Ti–23Nb–0.7Ta–2.0Zr–1.2O at.%, free of cytotoxic content), which was fabricated at Toyota Central Research&Development Laboratories, Inc., were investigated. It was confirmed that Gum Metal is characterized by a low Young's modulus (around 60 GPa), high strength (over 1000 MPa) and a large range of reversible deformation, which are important features in the context of potential implant applications. Moreover, a comprehensive assessment of biocompatibility was realized. Properties of Gum Metal were contrasted with those of Ti-6Al-4V (ELI) which was taken as reference. Surface conditions, such as topography, roughness and structural composition, were analyzed. Evaluation of biocompatibility for the alloys was performed by cell attachment and spreading analysis after predefined cell culture periods. Gum Metal presented excellent properties, what makes it a goodcandidate for implant applications. Keywords: Gum Metal, titanium alloy, biocompatibility, implant applications | |
96. | Popławski B., Mikułowski G., Mróz A., Sekuła K., Jankowski Ł., A decentralized strategy of structural reconfiguration in mitigation of vibrations, Procedia Engineering, ISSN: 1877-7058, DOI: 10.1016/j.proeng.2017.09.363, No.199, pp.1683-1688, 2017Popławski B., Mikułowski G., Mróz A., Sekuła K., Jankowski Ł., A decentralized strategy of structural reconfiguration in mitigation of vibrations, Procedia Engineering, ISSN: 1877-7058, DOI: 10.1016/j.proeng.2017.09.363, No.199, pp.1683-1688, 2017Abstract: This contribution proposes a decentralized closed-loop control algorithm for semi-active mitigation of free vibrations in frame structures. The control uses dedicated dissipative devices, which consist of two controllable structural nodes placed pairwise in both ends of selected structural beams. The nodes are capable of a controlled transition between the standard frame mode of operation (full moment-bearing ability) and the truss mode in which they do not bear any moments and constitute in fact structural hinges. Synchronous switching is equivalent to reconfiguration of the global structure by (dis)allowing the involved beams to transmit moments and to accumulate vibration energy in the form of their bending strain. Upon switching to the truss mode, the accumulated energy is released into high-frequency local vibrations, which undergo quick dissipation by standard mechanisms of material damping. The approach is illustrated in a numerical example and verified in a preliminary experimental test. Keywords: Mitigation of vibrations, Semi-active control, Decentralized control, Structural reconfiguration | |
97. | Gawlicki M., Jankowski Ł., Identification of moving loads using the l1 norm minimization, CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), pp.1-2, 2017Gawlicki M., Jankowski Ł., Identification of moving loads using the l1 norm minimization, CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), pp.1-2, 2017Abstract: This contribution deals with the inverse problem of indirect identification of moving loads. The identification is performed based on the recorded response of the loaded structure and its numerical model. A specific feature of such problems is a very large number of the degrees of freedom (DOFs) that can be excited and a limited number of available sensors. As a result, unless the solution space is significantly limited, the identification problem is underdetermined: it has an infinite number of exact, observationally indistinguishable solutions. We propose an approach based on the assumption of sparsity of the excitation, which can be expressed in the form of a requirement of a bounded l1 norm of the solution. As long as the loads are sparse, the approach allows them to be freely moving, without the usual assumption of a constant velocity. We test the approach in a numerical example with 10% rms measurement noise and describe an experimental setup that is being prepared to perform experimental verification. Keywords: inverse problems, structural mechanics, moving load identification, sparsity, l1 norm | |
98. | Popławski B., Mikułowski G., Mróz A., Jankowski Ł., Decentralized damping of vibrations in 2D frame structures using controllable nodes, SMART 2017, 8th Conference on Smart Structures and Materials, 2017-06-05/06-08, Madrid (ES), pp.94-103, 2017Popławski B., Mikułowski G., Mróz A., Jankowski Ł., Decentralized damping of vibrations in 2D frame structures using controllable nodes, SMART 2017, 8th Conference on Smart Structures and Materials, 2017-06-05/06-08, Madrid (ES), pp.94-103, 2017Abstract: Extensive research efforts have been recently devoted to semi-active structural control with its paradigms of smart self-adaptivity and low consumption of energy, which is used for local adaptation rather than to generate external control forces. Considered application areas include adaptive landing gears, seismic isolation systems, vehicle-track/span systems, power train electro-mechanical systems, damping of flexible space structures, vehicle crashworthiness, arctic engineering, wind turbines, etc. A part of the research concerns semi-active management of strain energy for damping of structural vibrations. Early works considered truss structures with stiffness-switched bars. They later evolved into either standalone one degree of freedom stiffness-switched dampers and isolators or investigations in triggering modal energy transfer to highly-damped high-order modes. The latter researches seem all to study the fundamental vibration mode of a cantilever beam with two detachable layers and differ mainly in the actuator technologies; the main idea is to employ actuators for a quick release of the vibration-related strain energy. This research extends the problem to general 2D frames. Controllable truss-frame nodes are incorporated into the structure. Thanks to their controllable ability to transmit moments, they allow for a quick transition between truss and frame modes. We propose a new, decentralized, closed-loop control strategy based on local energy measures. Vibration damping is more effective than in the previously studied control scheme based on a global energy measure, especially for higher vibration modes. Mitigation of vibrations will be presented in representative numerical examples, including a comparison to the global energy-based control strategy. Finally, results of experimental study, conducted on a structure analogous to the one from numerical simulations, will be demonstrated. Keywords: Vibration damping, Smart structures, Semi-active control, PAR strategy, Decentralized damping strategy | |
99. | Zawidzki M., Jankowski Ł., Szklarski J., Structural optimization of a five-unit single-branch Truss-Z modular structure, SMART 2017, 8th Conference on Smart Structures and Materials, 2017-06-05/06-08, Madrid (ES), pp.525-535, 2017Zawidzki M., Jankowski Ł., Szklarski J., Structural optimization of a five-unit single-branch Truss-Z modular structure, SMART 2017, 8th Conference on Smart Structures and Materials, 2017-06-05/06-08, Madrid (ES), pp.525-535, 2017Abstract: Truss-Z (TZ) is an Extremely Modular System (EMS). Such systems allow for creation of structurally sound free-form structures, are comprised of as few types of modules as possible, and are not constrained by a regular tessellation of space. Their objective is to create spatial structures in given environments connecting given terminals without self-intersections and obstacle-intersections. In an EMS, the assembly, reconfiguration and deployment difficulty is moved towards the module, which is relatively complex and whose assembly is not intuitive. As a result, an EMS requires intensive computation for assembling its desired free-form geometrical configuration, while its advantage is the economization of construction and reconfiguration by extreme modularization and mass prefabrication. TZ is a skeletal modular system for creating free-form pedestrian ramps and ramp networks among any number of terminals in space. TZ structures are composed of four variations of a single basic module (Truss-Z module, TZM) subjected to affine transformations (mirror reflection and rotation). The previous research on TZ focused on global discrete optimization of the spatial configuration of modules. This contribution reports on the first attempts at structural optimization of the TZM for a single-branch TZ. Namely, the internal topology of a TZM and sizing of its elements are subject to optimization. An important challenge is due the fact that TZM is to be universal, i.e., it must be designed for the worst case scenario. There are four variations of each module, and due to symmetries there are thus 4^4 = 256 unique 5-unit configurations. The structural performance of all of them needs to be evaluated in terms of a typical structural criterion (the maximum von Mises effective stress), and used for structural optimization at the level of a single TZM. Keywords: Extremely Modular System, Truss-Z, Structural optimization, Effective stress | |
100. | Faraj R., Popławski B., Suwała G., Jankowski Ł., Holnicki-Szulc J., Mitigation of dynamic response in frame structures by means of smart joints, SMART 2017, 8th Conference on Smart Structures and Materials, 2017-06-05/06-08, Madrid (ES), pp.138-144, 2017Faraj R., Popławski B., Suwała G., Jankowski Ł., Holnicki-Szulc J., Mitigation of dynamic response in frame structures by means of smart joints, SMART 2017, 8th Conference on Smart Structures and Materials, 2017-06-05/06-08, Madrid (ES), pp.138-144, 2017Abstract: This paper discusses passive and semi-active techniques of structural control by means of smart joints, and then it proposes a specific smart joints system for frame structures and tests its capability in mitigation of free vibrations. Basically, the proposed solution modifies frame beams by addition of truss-type hinges, and its effectiveness relies on the softening effect that occurs in compression due to geometric nonlinearities and which triggers the highly-damped high-frequency response modes of the structure. First, the finite element (FE) model of the specific frame structure with geometrical nonlinearities is derived, and the proposed passive joints are described and incorporated into the model. Then, their principle of operation and effectiveness is examined numerically for the first two natural modes of vibrations with various initial displacement amplitudes. An objective function is proposed to assess joints placement, based on the efficiency in mitigation of the excited vibrations. Keywords: Vibration Damping, Structure Response, Smart Structure, Structural Control | |
101. | Zawidzki M., Jankowski Ł., Multicriterial optimization of geometrical and structural properties of the basic module of a single-branch Truss-Z structure, WCSMO12, 12th World Congress of Structural and Multidisciplinary Optimisation, 2017-06-05/06-09, Braunschweig (DE), pp.1-9, 2017Zawidzki M., Jankowski Ł., Multicriterial optimization of geometrical and structural properties of the basic module of a single-branch Truss-Z structure, WCSMO12, 12th World Congress of Structural and Multidisciplinary Optimisation, 2017-06-05/06-09, Braunschweig (DE), pp.1-9, 2017Abstract: Truss-Z (TZ) is an Extremely Modular System (EMS). Such systems allow for creation of structurally sound free-form structures, are comprised of as few types of modules as possible, and are not constrained by a regular tessellation of space. Their objective is to create spatial structures in given environments connecting given terminals without self-intersections and obstacle-intersections. In an EMS, the assembly, reconfiguration and deployment difficulty is moved towards the module, which is relatively complex and whose assembly is not intuitive. As a result, an EMS requires intensive computation for assembling its desired free-form geometrical configuration, while its advantage is the economization of construction and reconfiguration by extreme modularization and mass prefabrication.
TZ is a skeletal modular system for creating free-form pedestrian ramps and ramp networks among any number of terminals in space. TZ structures are composed of four variations of a single basic module (Truss-Z module, TZM) subjected to affine transformations (mirror reflection and rotation). The previous research on TZ focused on global discrete optimization of the spatial configuration of modules. This contribution is the first attempt at structural optimization of the TZM for a single-branch TZ. The result is a multicriterial optimization, where the Pareto front provides the means to strike the optimal balance between geometric and structural assessment criteria. Keywords: multicriterial optimization, Truss-Z, effective stress, modular systems | |
102. | Gawlicki M., Jankowski Ł., Identification of moving loads via l1-constrained solutions, ECCOMAS - IPM 2017, 4th International Conference on Inverse Problems in Mechanics of Structures and Materials, 2017-05-31/06-02, Rzeszów - Krasiczyn (PL), pp.25-26, 2017Gawlicki M., Jankowski Ł., Identification of moving loads via l1-constrained solutions, ECCOMAS - IPM 2017, 4th International Conference on Inverse Problems in Mechanics of Structures and Materials, 2017-05-31/06-02, Rzeszów - Krasiczyn (PL), pp.25-26, 2017Abstract: Indirect identification of moving loads based on the measured response is one of the crucial problems in structural health monitoring. It is important in automated assessment of structures and pavements, in traffic monitoring and control, and as a prerequisite for structural control. As such, it has been intensively researched. An important difficulty is that a moving load can excite a very large number of structural Dofs, which all have to be taken into account in the identification procedure based on measurements of a much more limited number of sensors. A straightforward formulation yields thus an underdetermined problem with an infinite number of solutions. Therefore, in most of the approaches so far, the solution space is significantly limited by the assumption that the load corresponds to a single vehicle moving at a constant velocity, which excludes loads of a more general nature (e.g., multiple loads). However, instead of limiting the solution space, it can be noted that in practice moving loads are sparse in time and space, which fits the framework of compressed sensing. Such an a priori knowledge of sparsity is typically expressed by limiting the l1 norm of the solution. To our knowledge, although used in other contexts, the concept has not been applied so far for identification of moving loads. The approach is tested in a numerical example with 10% rms measurement noise. Experimental work is in progress. | |
103. | Hołobut P., Lengiewicz J., Distributed computation of forces in modular-robotic ensembles as part of reconfiguration planning, ICRA 2017, IEEE International Conference on Robotics and Automation, 2017-05-29/06-03, Marina Bay Sands (SG), DOI: 10.1109/ICRA.2017.7989242, No.7989242, pp.2103-2109, 2017Hołobut P., Lengiewicz J., Distributed computation of forces in modular-robotic ensembles as part of reconfiguration planning, ICRA 2017, IEEE International Conference on Robotics and Automation, 2017-05-29/06-03, Marina Bay Sands (SG), DOI: 10.1109/ICRA.2017.7989242, No.7989242, pp.2103-2109, 2017Abstract: We discuss selected mechanical aspects of self-reconfiguration of densely-packed modular robots. The change of connection topology and transport of modules are fundamental mechanisms for these systems, which determine their desired emergent behavior, e.g., movement, shape change or interaction with their surroundings. At the same time, reconfiguration affects the forces between modules. We present a distributed procedure by which a robot can predict if the next planned reconfiguration step will overstress intermodular connections. We use a Finite Element model of a modular robot, with one-node-per-module discretization and beam elements representing intermodular connections. The analysis is restricted to static loads and linear elasticity. We present a distributed procedure of aggregation of the stiffness matrix and iterative solution of the resulting equations of elasticity. The procedure is illustrated with numerical examples and analyzed in terms of its efficiency. © 2017 IEEE. Keywords: Finite element method, Modular robots, Stiffness matrix, Distributed computations, Iterative solutions, Reconfiguration planning | |
104. | Meissner M., Metoda zwiększająca dokładność dyskretnej transformaty Hilberta przy wyznaczaniu amplitudy i częstotliwości sygnałów wibroakustycznych, WibroTech 2017, XIX Konferencja Naukowa Wibroakustyki i Wibrotechniki, XIV Ogólnopolskie Seminarium Wibroakustyka w Systemach Technicznych, 2017-05-19/05-20, Pruszków (PL), pp.71-74, 2017Meissner M., Metoda zwiększająca dokładność dyskretnej transformaty Hilberta przy wyznaczaniu amplitudy i częstotliwości sygnałów wibroakustycznych, WibroTech 2017, XIX Konferencja Naukowa Wibroakustyki i Wibrotechniki, XIV Ogólnopolskie Seminarium Wibroakustyka w Systemach Technicznych, 2017-05-19/05-20, Pruszków (PL), pp.71-74, 2017Keywords: wibroakustyka, analiza sygnałów, dyskretna transformata Hilberta | |
105. | Błachowski B., Gutkowski W., Lagrangian dynamics based approach for 3D modelling of human gait, CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), pp.MS09-33-MS09-34, 2017Błachowski B., Gutkowski W., Lagrangian dynamics based approach for 3D modelling of human gait, CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), pp.MS09-33-MS09-34, 2017Abstract: The purpose of this study is the mechanism of the spatial movement of a human during walking. The human is considered to be a rigid body with six degrees of freedom, and its mobility is reduced by two constraints. One of the constraints is related to an assumption of constant length of the leg, foot of which is moving along given straight line. The second constraint corresponds to an assumption that human’s centre of mass can move only in vertical plane. The dynamic model of the mechanism is built under above assumptions connected to the human gait kinematics. Then, kinetic energy function is derived. In the next step of the study the muscle force in the stance leg, together with its potential, is discussed. It is assumed that this force is piecewise-linear, which can be reasonably approximated by a cubic polynomial. For that purpose a smoothing procedure is proposed and finally with the aid of the Lagrange function dynamic equations for the 3D human gait are formulated. The last part of the paper is devoted to the numerical solution of obtained nonlinear equations, arising from the Lagrange procedure. Keywords: human walking, gait analysis, lagrangian dynamics | |
106. | Jarosik P., Lewandowski M., The feasibility of deep learning algorithms integration on a GPU-based ultrasound research scanner, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), DOI: 10.1109/ULTSYM.2017.8091750, pp.1-4, 2017Jarosik P., Lewandowski M., The feasibility of deep learning algorithms integration on a GPU-based ultrasound research scanner, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), DOI: 10.1109/ULTSYM.2017.8091750, pp.1-4, 2017Abstract: Ultrasound medical diagnostics is a real-time modality based on a doctor's interpretation of images. So far, automated Computer-Aided Diagnostic tools were not widely applied to ultrasound imaging. The emerging methods in Artificial Intelligence, namely deep learning, gave rise to new applications in medical imaging modalities. The work's objective was to show the feasibility of implementing deep learning algorithms directly on a research scanner with GPU software beamforming. We have implemented and evaluated two deep neural network architectures as part of the signal processing pipeline on the ultrasound research platform USPlatform (us4us Ltd., Poland). The USPlatform is equipped with a GPU cluster, enabling full software-based channel data processing as well as the integration of open source Deep Learning frameworks. The first neural model (S-4-2) is a classical convolutional network for one-class classification of baby body parts. We propose a simple 6-layer network for this task. The model was trained and evaluated on a dataset consisting of 786 ultrasound images of a fetal training phantom. The second model (Gu-net) is a fully convolutional neural network for brachial plexus localisation. The model uses ‘U-net’-like architecture to compute the overall probability of target detection and the probability mask of possible target locations. The model was trained and evaluated on 5640 ultrasound B-mode frames. Both training and inference were performed on a multi-GPU (Nvidia Titan X) cluster integrated with the platform. As performance metrics we used: accuracy as a percentage of correct answers in classification, dice coefficient for object detection, and mean and std. dev. of a model's response time. The ‘S-4-2’ model achieved 96% classification accuracy and a response time of 3 ms (334 predictions/s). This simple model makes accurate predictions in a short time. The ‘Gu-net’ model achieved a 0.64 dice coefficient for object detection and a 76% target's presence classification accuracy with a response time of 15 ms (65 predictions/s). The brachial plexus detection task is more challenging and requires more effort to find the right solution. The results show that deep learning methods can be successfully applied to ultrasound image analysis and integrated on a single advanced research platform Keywords: Ultrasonic imaging, Neural networks, Convolution, Machine learning, Image segmentation, Kernel | |
107. | Rozbicki J., Witek B., Steifer T., Lewandowski M., Doppler-based blood pressure measurement system for patients supported by a continuous-flow rotary left ventricular assist device, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), DOI: 10.1109/ULTSYM.2017.8091990, pp.1-4, 2017Rozbicki J., Witek B., Steifer T., Lewandowski M., Doppler-based blood pressure measurement system for patients supported by a continuous-flow rotary left ventricular assist device, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), DOI: 10.1109/ULTSYM.2017.8091990, pp.1-4, 2017Abstract: The medical management of patients with continuous-flow left ventricular assist devices (LVADs) requires frequent measurement and analysis of various physiological parameters. Among the most important is blood pressure (BP), which cannot be reliably measured by the standard oscillometric method because of an impaired pulsation due to continuous flow. The objective of this work is to show the feasibility of ultrasound-based BP measurement in a portable, easy to use device for patients with LVAD in home-based rehabilitation environments, enabling long-term remote monitoring. We have implemented a BP measurement system which uses continuous wave (CW) Doppler ultrasound for blood flow detection. The system is based on a standard cuff design with custom analog CW circuitry connected to a high-performance, low-power 32-bit microcontroller (ARM Cortex-M7). The uC is responsible for system control, as well as Doppler signal acquisition and processing. A dedicated ultrasound probe equipped with an elastic strap is placed over the radial artery. In the target solution, the cuff pressure and CW signal will be analyzed in real-time to provide systolic and/or mean blood pressure. At present, we have acquired raw signals for off-line analysis. The system was tested in clinical experiments both on healthy patients and patients with three types of commercially available LVADs (HeartWare, HeartMate II and HeartMate III). The observed morphology of Doppler signals in patients with LVADs was much more variable between patients and pumps. In most cases, we were able to estimate the systolic pressure, but the measurement of diastolic pressure was not conclusive. We observed variable blood flow patterns generated by the Lavare cycle (a periodic speed modulation feature of some LVADs), which further complicates the estimation. A prototype of an automatic BP measuring device for patients with rotary LVADs has been demonstrated. In the next step, we are planning an animal validation study with invasive blood pressure monitoring Keywords: Biomedical monitoring, Doppler effect, Blood pressure, Blood, Pressure measurement, Ultrasonic variables measurement, Standards | |
108. | Ziółkowski A., Disastrous air crash and two investigations with different results, International Journal of Forensic Engineering, ISSN: 1744-9944, DOI: 10.1504/IJFE.2017.10005136, Vol.3, No.4, pp.277-302, 2017Ziółkowski A., Disastrous air crash and two investigations with different results, International Journal of Forensic Engineering, ISSN: 1744-9944, DOI: 10.1504/IJFE.2017.10005136, Vol.3, No.4, pp.277-302, 2017Abstract: The case study is analyzed of the catastrophe of Polish Air Force One, TU-154M aircraft on 10th of April 2010, near Smolensk North airfield, Russia. The catastrophe ended up in total destruction of the aircraft and death of all the passengers and crew on board. The results of the official investigations of the Russian Federation executed by the Interstate Aviation Committee and Poland executed by the Committee for Investigation of State Aviation Accidents are recalled, which found that the crash resulted due to pilot's errors. The evidence is presented showing faults in official examination proceedings and thus existence of grounds for possibility of drawing false conclusions. An academic investigation effort is undertaken to reconstruct the course of events during the last few seconds of flight of the TU-154M aircraft. The publicly available data, photographic evidence, and circumstantial information have been analyzed, which allowed pointing out a number of observations, which were not reliably explained by official reports scenarios. In view of that, execution of a new fully fledged repair investigation is recommended. Keywords: Air Force One, Polish TU-154M, Smolensk, aircraft crash, catastrophe, academic investigation, repair examination, abductive analysis, metallic fragments, airframe wreckage, blast, explosive damage, TAWS, aircraft safety engineering | |
109. | Byra M., Piotrzkowska-Wróblewska H., Dobruch-Sobczak K., Nowicki A., Combining Nakagami imaging and convolutional neural network for breast lesion classification, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), DOI: 10.1109/ULTSYM.2017.8092154, pp.1-4, 2017Byra M., Piotrzkowska-Wróblewska H., Dobruch-Sobczak K., Nowicki A., Combining Nakagami imaging and convolutional neural network for breast lesion classification, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), DOI: 10.1109/ULTSYM.2017.8092154, pp.1-4, 2017Abstract: In this paper we propose a computer-aided diagnosis system for the breast lesion classification. Our approach is based on quantitative ultrasound and deep learning. We used the Nakagami imaging to create parametric maps of breast lesions that illustrate tissue scattering properties. For this task the sliding window technique was applied. The Nakagami parameter was calculated using the maximum likelihood estimator. Next, we used the Nakagami parameter maps to train a convolutional neural network. Classification performance was evaluated by 5-fold cross-validation. We obtained the area under the receiver operating characteristic curve equal to 0.91. The results showed that our approach is useful to distinguishing between malignant and benign breast lesions. The proposed method serves as a general approach for tissue characterization and differentiation. The Nakagami parameter used in this study can be replaced with other QUS parameters and the neural network can be trained in a similar fashion. Keywords: Nakagami imaging, quantitative ultrasound, convolutional neural networks, breast lesion classification, deep learning | |
110. | Byra M., Wójcik J., Nowicki A., Ultrasound nonlinearity parameter assessment using plane wave imaging, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), DOI: 10.1109/ULTSYM.2017.8092733, pp.1-4, 2017Byra M., Wójcik J., Nowicki A., Ultrasound nonlinearity parameter assessment using plane wave imaging, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), DOI: 10.1109/ULTSYM.2017.8092733, pp.1-4, 2017Abstract: In this paper we investigate how to assess the ultrasound nonlinearity coefficient using plane wave imaging. We employ the technique based on excitation of the medium with ultrasonic pulses of increasing amplitude level. As the pulse pressure is increased, due to medium nonlinearity, higher fraction of energy is transferred from the fundamental to higher harmonics during the propagation. In this case the amplitude of the backscattered echo is not linear in respect to the initial pulse amplitude at source. This phenomenon can be used for the nonlinearity coefficient assessment and show its implementation for the plane wave imaging. The method was validated experimentally using a wire phantom immersed in water and scanned using the Verasonics scanner. We discuss the usefulness of the proposed technique and its shortcomings. In comparison to other nonlinearity coefficient assessment methods, the presented technique works in the pulse-echo mode and it doesn't require information on second harmonic or using a special wide-band transducer. The method can be implemented directly into a medical scanner. Keywords: Plane wave imaging, nonlinear ultrasound, quantitative ultrasound, coefficient of nonlinearity | |
111. | Pawłowski P., Frąś T.^{♦}, Numerical and experimental investigation of asymmetrical contact between a steel plate and armour-piercing projectiles, LS-DYNA 2017, European LS-DYNA Conference 2017, 2017-05-09/05-11, Salzburg (AT), pp.1-9, 2017Pawłowski P., Frąś T.^{♦}, Numerical and experimental investigation of asymmetrical contact between a steel plate and armour-piercing projectiles, LS-DYNA 2017, European LS-DYNA Conference 2017, 2017-05-09/05-11, Salzburg (AT), pp.1-9, 2017Abstract: Protection of combat-vehicles against impacts of small-calibre projectiles may be improved by the application of relatively thin and hard steel plates perforated by a plurality of holes. It is observed that due to the contact with a plate,the core of armour-piercing (AP) projectiles may be shattered, partially eroded or rotated, depending on the hit-position. The contact asymmetry is the strongest when a projectile hits a hole edge, its core undergoes bending and tends to fracture. The presented study discusses two methods of modelling of the contact and interactions between a bullet and a steel target. One of them is the explicit Lagrangian simulation of impacts of a fully represented AP projectile, another one is the semi-analytical model based on the integration of the motion equations of a 6 DOF rigid projectile. The results of numerical and semi-analytical approaches are compared with the ballistic impact experiment, in which the defeat mechanisms provided by 4-mm-thick slotted bainitic plates (Pavise™ SBS 600P) against hard-core 7.62 mm P80 0.30 AP x 51 (.308 Win) projectiles were verified, [1]. | |
112. | Pawłowski P., Skłodowski M., Górecka K., ZASTOSOWANIE METOD OPTYCZNYCH W DIAGNOSTYCE KSZTAŁTU I DEFORMACJI WIELKOFORMATOWYCH OBRAZÓW KRZYWOLINIOWYCH, Diagnostyka 2017, XLIV Ogólnopolskie Sympozjum DIAGNOSTYKA MASZYN, 2017-02-26/03-02, Wisła (PL), pp.1-2, 2017Pawłowski P., Skłodowski M., Górecka K., ZASTOSOWANIE METOD OPTYCZNYCH W DIAGNOSTYCE KSZTAŁTU I DEFORMACJI WIELKOFORMATOWYCH OBRAZÓW KRZYWOLINIOWYCH, Diagnostyka 2017, XLIV Ogólnopolskie Sympozjum DIAGNOSTYKA MASZYN, 2017-02-26/03-02, Wisła (PL), pp.1-2, 2017Abstract: Wśród europejskiego dziedzictwa obrazów wielkoformatowych można wyróżnić szczególną grupę płócien nieplanarnych. W trakcie prowadzonych prac badawczych i konserwatorskich należy odpowiedzieć na pytania o pierwotny kształt aktualnie zdeformowanego obrazu, stopień zniekształcenia płótna, wpływ pełzania na deformację oraz bezpieczny sposób przywrócenia właściwego kształtu i zabezpieczenia przed jego zmianą w przyszłości.
Wielkoformatowe obrazy na płótnie podlegają znaczącym deformacjom wynikającym z procesów reologicznych aktywowanych zmianami wilgotności i temperatury. Deformacje te narastają wraz z upływem czasu pod wpływem sił wynikających z ciężaru własnego i napięcia na krośnie. Efekty te mają tym większe znaczenie im większa jest powierzchnia obrazu. Ich konserwacja i prawidłowe napięcie stanowią szczególnie trudne wyzwanie konserwatorskie.
Wszystkie te problemy pojawiły się w trakcie konserwacji obrazu „Pokłon Trzech Króli” H.M. Lodera, który znajduje się w katedrze w Namur (Belgia). Obraz o wymiarach 3.70m x 4.50m zawieszony był w prezbiterium kościoła i miał wygiętą formę, zbliżoną do łuku ściany absydy. Strzałka łuku krosna wynosiła 37cm. Do najpoważniejszych problemów należały katastrofalne w skutkach deformacje osłabionego mechanicznie podobrazia. Płótno pod wpływem własnego ciężaru i zachodzących procesów reologicznych wyciągnęło się i zaczęło obwisać, tak że jego nadmiar zebrał się w części centralnej u dołu malowidła.
W trakcie prowadzonych prac opracowana została metodyka pomiaru, korekcji kształtu i napinania obrazów wielkoformatowych. Po wykonaniu zdalnych pomiarów optycznych zawieszonego na ścianie obrazu (globalny i lokalny skaning laserowy, fotogrametria) dokonano identyfikacji zdeformowanego i pierwotnego kształtu płótna. Następnie zaproponowano nowatorski sposób wzmocnienia i napinania płótna polegający na wprowadzeniu w warstwie dublażowej układu nici aramidowych poprowadzonych wzdłuż tworzących zidentyfikowanej powierzchni prostokreślnej płótna. Wielokrotnie większy moduł sprężystości nici aramidowych niż płótna dublażowego umożliwia przeniesienie dominującej części naprężeń wynikających z napięcia płótna i ciężaru własnego obrazu. W połączeniu ze znacznie mniejszą wrażliwością aramidu na zmiany wilgotności i temperatury znacząco zmniejsza się także intensywność procesów reologicznych ograniczając pełzanie, obwisanie i utrwalając krzywoliniowy kształt obrazu. | |
113. | Chikahiro Y., Ario I., Pawlowski P., Graczykowski C., Nakazawa M., Holnicki-Szulc J., Ono S., Dynamics of the scissors-type Mobile Bridge, EURODYN 2017, X International Conference on Structural Dynamics, 2017-09-10/09-13, Rome (IT), DOI: 10.1016/j.proeng.2017.09.339, No.199, pp.2919-2924, 2017Chikahiro Y., Ario I., Pawlowski P., Graczykowski C., Nakazawa M., Holnicki-Szulc J., Ono S., Dynamics of the scissors-type Mobile Bridge, EURODYN 2017, X International Conference on Structural Dynamics, 2017-09-10/09-13, Rome (IT), DOI: 10.1016/j.proeng.2017.09.339, No.199, pp.2919-2924, 2017Abstract: We have experienced many times a phenomenon in which a bridge is washed away due to a typhoon, heavy rain in the rainy season, localized torrential rain, tsunami, and other flood disasters, or in which a bridge is damaged by an earthquake or a tremor. There is accordingly increasing demand for new technology and science to restore bridges that have been washed away or damaged. The paper presents a new type of emergency bridge, called Mobile Bridge™(MB), which can be quickly constructed in case of damages after a natural disaster. The concept of the bridge is based on the application of scissor-type mechanism, which provides its rapid deployment. Up to now several experimental MBs of different size were constructed and tested. The presented research reviews fundamental numerical and experimental results for the MB version 4.0 (MB4.0). Experimental testing included strain and acceleration measurements in free and forced loading conditions. From these results, it was possible to estimate basic dynamic characteristics of the bridge. Besides, in order to provide a basis for development of new construction methods for structural reinforcement and suppression of vibrations, various numerical analyses were conducted. The conducted research allows for a better and safer design of the movable and foldable full-scale bridge, the MB. Keywords: deployable bridge, scissors-type bridge, emergency bridge, light-weight structure, temporary bridge | |
114. | Graczykowski C., Pawłowski P., Mathematical Modelling of Adaptive Skeletal Structures for Impact Absorption and Vibration Damping, EURODYN 2017, X International Conference on Structural Dynamics, 2017-09-10/09-13, Rome (IT), DOI: 10.1016/j.proeng.2017.09.093, No.199, pp.1671-1676, 2017Graczykowski C., Pawłowski P., Mathematical Modelling of Adaptive Skeletal Structures for Impact Absorption and Vibration Damping, EURODYN 2017, X International Conference on Structural Dynamics, 2017-09-10/09-13, Rome (IT), DOI: 10.1016/j.proeng.2017.09.093, No.199, pp.1671-1676, 2017Abstract: The paper describes mathematical modelling of adaptive skeletal structures, which are equipped with semi-active dissipaters based on smart fluids or fast-operating valves and utilize the paradigm of real-time adaptation to external loading. The proposed approach is based on three subsequent stages: i) exact thermodynamic modelling of a single semi-active dissipater with the use of mass, momentum and energy conservation laws, ii) global description of the entire skeletal structure considered as an assembly of semi-active dissipaters in certain geometrical configuration, iii) real-time control of the fluid flow inside semi-active dissipaters providing instantaneous adaptability to actual dynamic loading. This methodology enables accurate representation of mechanical characteristics of the skeletal structure and reliable analysis of its adaptation capabilities. Keywords: adaptive structures, skeletal structures, impact absorption, vibration damping | |
115. | Nakielski P., Pierini F., Piechocka I.K., Kowalewski T.K., Blood clotting in the contact with polymer nanofibers, Bloodsurf2017, Blood-biomaterial interface: where medicine and biology meet physical sciences and engineering, 2017-09-17/09-21, Clemson, SC (US), pp.35, 2017Nakielski P., Pierini F., Piechocka I.K., Kowalewski T.K., Blood clotting in the contact with polymer nanofibers, Bloodsurf2017, Blood-biomaterial interface: where medicine and biology meet physical sciences and engineering, 2017-09-17/09-21, Clemson, SC (US), pp.35, 2017Abstract: Electrospun nanofibers are increasingly studied thanks to their potential applications in biomedical devices that include drug delivery systems and tissue engineering scaffolds [1]. Numerous synthetic and natural polymers were used to develop nanofibrous materials. Nanostructured materials high porosity, surface-to- volume ratio together with the ease in surface functionalization and drug incorporation, make them perfect candidates for the development of hemostats. Immediate hemorrhage management becomes crucial to preventing death and serious injury in emergency situations. Severe injuries caused by e.g. traffic accidents are the third leading cause of death worldwide [2]. Research on medical incidents of soldiers stationed in Iraq in 2003-2004 showed that the main cause of death was massive hemorrhage that led to death in about 51% of the rescued soldiers [3]. There is no universal dressing and despite the development of new hemostats, they fail in many preclinical studies. Therefore, there is a need to define most important nanofibrous material characteristics that are responsible for rapid and effective bleeding arrest.
There is little research on nanostructured hemostats, regarding the impact of nanofibrous surface on blood and its components. Nonetheless, because of the wide use of nanofibres in wound dressings, artificial blood vessels as well as heart valves, there is knowledge helpful in determining material surface chemistry, wettability and other, which can affect blood coagulation. The very first findings appeared in the research where it was found that even polymers having excellent antiplatelet adhesion abilities, triggered increased platelet adhesion and activation when they were in the form of nanofibers. In several other studies, scaffold morphology, was found to have larger impact on platelet adhesion and activation than differences in the chemistry of the polymers used [4]. More specifically, it was found that materials with fiber diameter higher than 1 µm triggered higher platelet adhesion and aggregation than smaller fibers. In other research, nanofiber stiffness was assessed as more dominating than biological moieties and surface roughness of the nanofiber [5]. In spite of all, analyzed literature presents many contradictory results or findings that had low or no impact on blood clotting in research results of other groups. Hence, additional research and novel experimental methods are needed to find nano features that impact hemostat efficiency.
Acknowledgements
The authors acknowledge the support from NCN grant no. 2015/19/D/ST8/03192.
References:
[1] Nakielski P. et al., J Biomed Mater Res Part B 103B:282–291, 2015
[2] Kauvar D. et al., J of Trauma-Injury Inf &Crit Care, 60(6):3-11, 2006
[3] Kelly J.F. et al., J Trauma, 64:S21-6; 2008
[4] Milleret V. et al., Acta Biomaterialia 8(12):4349–4356, 2012
[5] Merkle V.M. et al., Appl. Mater. Interfaces, 7 (15):8302–8312, 2015
Keywords: blood-biomaterial interactions, nanofibers, clotting, | |
116. | Chmielewski M., Pietrzak K.^{♦}, Strojny-Nędza A., Kaszyca K., Nosewicz S., Jarząbek D., The effect of nickel coating on the properties of Cu-SiC composites, EUROMAT 2017, European Congress and Exhibition on Advanced Materials and Processes, 2017-09-17/09-22, Thessaloniki (GR), pp.1, 2017 | |
117. | Nosewicz S., Rojek J., Maździarz M., Kowalczyk P., Wawrzyk K., Chmielewski M., Pietrzak K.^{♦}, Multiscale modeling of pressure-assisted sintering process, EUROMAT 2017, European Congress and Exhibition on Advanced Materials and Processes, 2017-09-17/09-22, Thessaloniki (GR), pp.1, 2017 | |
118. | Chikahiro Y., Ario I., Adachi K., Shimizu S., Zenzai S., Pawłowski P., Graczykowski C., Holnicki-Szulc J., FUNDAMENTAL STUDY ON DYNAMIC PROPERTY OF SCISSORING BRIDGE FOR DISASTER RELIEF, ENOC 2017, 9th European Nonlinear Dynamics Conference, 2017-06-25/06-30, Budapest (HU), pp.1-2, 2017Chikahiro Y., Ario I., Adachi K., Shimizu S., Zenzai S., Pawłowski P., Graczykowski C., Holnicki-Szulc J., FUNDAMENTAL STUDY ON DYNAMIC PROPERTY OF SCISSORING BRIDGE FOR DISASTER RELIEF, ENOC 2017, 9th European Nonlinear Dynamics Conference, 2017-06-25/06-30, Budapest (HU), pp.1-2, 2017Abstract: The world has seen many kinds of natural disasters, which have critically influenced the residents’ lives by causing damage to infrastructure. To realize rapid rescue efforts in an emergency situation,we propose a deployable emergency bridge, called Mobile Bridge TM [1], based on the theory of foldable structures[2]and the concept of Multi-Folding Microstructures (MFM)[3]. The current research presents the fundamental,numerical and experimental results obtained for the pedestrian and vehicle Mobile Bridges. In this paper, it is considered the localized linearization problem with the fixed an angle although this bridge contains a geometrical nonlinearity of scissors structure.Additionally, a seismic response analysis is conducted for the case where the Mobile Bridge is used in the disaster area as an emergency bridge. This allows for a better and safer structural design of the Mobile Bridge, which is patented in [4],[5]. | |
119. | Faraj R., Graczykowski C., Holnicki-Szulc J., Knap L., Seńko J., Adaptable pneumatic shock-absorber, SMART 2017, 8th Conference on Smart Structures and Materials, 2017-06-05/06-08, Madrid (ES), pp.1, 2017Faraj R., Graczykowski C., Holnicki-Szulc J., Knap L., Seńko J., Adaptable pneumatic shock-absorber, SMART 2017, 8th Conference on Smart Structures and Materials, 2017-06-05/06-08, Madrid (ES), pp.1, 2017Abstract: Pneumatic dampers are still an attractive subject of research in both modelling and experimental testing. Progress in the field of sensors and actuators allows to construct more and more efficient absorbers and dampers based on active or semi-active control algorithms. However, passive and semi-passive solutions are also developed because of their lower costs and simplicity. This paper presents adaptable pneumatic shock-absorber that allows to obtain optimal impact absorption and energy dissipation by a single reconfiguration performed at the beginning of the process. The absorber is composed of two cylinders including at least one narrow rectangular slot and adequate number of outflow vents precisely shaped for certain impact scenarios. During operation of the device the air is released through overlapping slots and selected vents, which provides constant value of the generated force. As a result, the shock-absorber works as a passive device but provides minimal value of the reaction force in similar manner as semi-active system equipped with fully controllable mechanical valve. The paper presents the results of numerical simulations of adaptable shock-absorber operation and attempts of demonstrator construction aimed at conducting experimental verification of the concept. Keywords: Adaptable, Semi-passive, Impact Absorption, Pneumatic Shock-absorber. | |
120. | Faraj R., Graczykowski C., Holnicki-Szulc J., Investigations on adaptable and adaptive impact absorption, ICAST2017, The 28th International Conference on Adaptive Structures and Technologies, 2017-10-08/10-11, Kraków (PL), pp.1, 2017 | |
121. | Szymczak T., Kowalewski Z.L., ON THE CRUCIFORM SPECIMENS FOR MATERIALS TESTING, DAS 2017, 34th Danubia-Adria Symposium on Advances in Experimental Mechanics, 2017-09-19/09-22, Trieste (IT), pp.1-2, 2017 | |
122. | Libura T., Kowalewski Z.L., Kowalczyk-Gajewska K., THE BAUSCHINGER EFFECT IN THIN SHEET MAGNESIUM ALLOY USING ANTI-BUCKLING FIXTURE, DAS 2017, 34th Danubia-Adria Symposium on Advances in Experimental Mechanics, 2017-09-19/09-22, Trieste (IT), pp.1-2, 2017 | |
123. | Kukla D., Zagórski A., Miś R., Wyszkowski M., BADANIA DIAGNOSTYCZNE RUR WYMIENNIKÓW CIEPŁA Z ZASTOSOWANIEM TECHNIK NIENISZCZĄCYCH, XXIII Seminarium NIENISZCZĄCE BADANIA MATERIAŁÓW, 2017-03-15/03-17, Zakopane (PL), pp.1-18, 2017 | |
124. | Pęcherski R.B., Nowak Z., Nowak M., Natonik K.J., Potoczek M., Śliwa R.E., PROBLEMS OF VIRTUAL CELLULAR MATERIALS: REPRESENTATIVE VOLUME ELEMENT AND ENERGY-BASED ASSESSMENT OF FAILURE STRENGTH , DBM, 11th Workshop Dynamic Behaviour of Materials and its Applications in Industrial Processes, 2017-08-23/08-25, Guimarães (PT), pp.12-13, 2017Pęcherski R.B., Nowak Z., Nowak M., Natonik K.J., Potoczek M., Śliwa R.E., PROBLEMS OF VIRTUAL CELLULAR MATERIALS: REPRESENTATIVE VOLUME ELEMENT AND ENERGY-BASED ASSESSMENT OF FAILURE STRENGTH , DBM, 11th Workshop Dynamic Behaviour of Materials and its Applications in Industrial Processes, 2017-08-23/08-25, Guimarães (PT), pp.12-13, 2017Abstract: Three kinds of cellular materials are considered. Depending on geometry and physical properties of the skeleton, these are metallic cellular materials with convex or reentrant open cell structure. To the third group belong alumina foams produced by gel casting method.
Finite element computations are used to analyse mechanical properties of a material volume. Such an analysis is usually related with big computational costs. Therefore, it is important to keep the size of the considered cellular material volume as small as possible. On the other hand, the validity of the continuum model requires the proper size of the RVE. The aim of the study is to estimate the sufficient size of representative volume element (RVE) in order to assess the validity of the elastic model of the considered cellular material. An array of cubes of virtual cellular material is used to compute the particular deformation modes providing elastic moduli, Young modulus E, shear modulus G and bulk modulus K as well as the resulting Poisson’s ratio.
Also the results of the microtomography of alumina foams are used to create the „virtual cellular material” i.e. the numerical model reconstructing the structure of real foam skeleton. The numerical simulations of compression test are performed. The results are compared with experimental data of elastic moduli and failure strength. The numerical simulations of failure strength under compression for alumina foams are performed. The calculations with use of the numerical model are time consuming. Therefore, the simpliﬁed method of the assessment of failure strength is proposed. It is based on the energy-based hypothesis on the equivalence of of elastic moduli and the resulting equivalence of the values of failure strength of real alumina foam and the cellular material with regular structure (e.g. fcc type). The justiﬁcation of the hypothesis based on experimental data of compression of alumina foam are discussed and the range of validity as regards porosity values is studied. Keywords: virtual cellular materials, convex skeleton, reentrant skeleton. representative volume element, numerical simulations | |
125. | Pęcherski R.B., Nowak Z., APPLICATION OF VIRTUAL CELLULAR MATERIAL CONCEPT FOR THE SIMULATIONS OF DYNAMIC LOADING PROCESSES , MatCel’2017 & DynMatCel’2017, Cellular Materials: Structural Behaviour, Modelling and Characterisation, 2017-09-25/09-27, Aveiro (PT), pp.54, 2017Pęcherski R.B., Nowak Z., APPLICATION OF VIRTUAL CELLULAR MATERIAL CONCEPT FOR THE SIMULATIONS OF DYNAMIC LOADING PROCESSES , MatCel’2017 & DynMatCel’2017, Cellular Materials: Structural Behaviour, Modelling and Characterisation, 2017-09-25/09-27, Aveiro (PT), pp.54, 2017Abstract: The subject of the study is the models based on digital microstructure, in particular open-cell metallic materials with the skeleton of convex or re-entrant cells. Recently, the auxetic materials have attracted increasing attention in the context of modern materials applications. The dynamic properties of such materials are less known. Impact compressions of the two kind of cellular materials under high-velocity are numerically analysed, [1]. To simulate the deformation processes the ﬁnite element program ABAQUS is used. The computer tomography makes the basis for the formulation of computational model and ﬁnite element discretization of the skeleton of virtual cellular material. For numerical simulations the constitutive elasto-viscoplasticity equations are applied that describe the dynamic behaviour of OFHC Cu. The numerical predictions of compression kinematics of the skeleton and crushing force for velocity 50 and 300 m/s are discussed. The results of computations are completed with the analysis of shock wave propagation. Keywords: virtual cellular material, dynamic loading, crushing force, auxetic material, OFHC Cu, shock vaves | |
126. | Nowak Z., Nowak M., Pęcherski R.B., DYNAMIC COMPRESSION STRENGTH OF COPPER OPEN-CELL FOAMS , DBM, 11th Workshop Dynamic Behaviour of Materials and its Applications in Industrial Processes, 2017-08-23/08-25, Guimarães (PT), pp.8-9, 2017Nowak Z., Nowak M., Pęcherski R.B., DYNAMIC COMPRESSION STRENGTH OF COPPER OPEN-CELL FOAMS , DBM, 11th Workshop Dynamic Behaviour of Materials and its Applications in Industrial Processes, 2017-08-23/08-25, Guimarães (PT), pp.8-9, 2017Abstract: Metal foams in view of their structural strength and mechanical energy absorption capability under high speed impact can be utilized as energy absorbers. It is important to understand the propagation of compaction waves in the foams. Most commercially available metal foams are made of aluminium, nickel, copper, and metal alloys. Two kinds of foams exist, namely the open-cell and the closed-cell foams. Typically, the pore density of uncompressed open-cell foams varies between 5 to 100 PPI (pores per inch), while the porosity is in the range from 70% to 95%. Literature provides several examples of metal foams solutions for energy absorption applications, dealing with both experimental, numerical and analytical studies.
The subject of the study are the models based on digital micro-structures, in particular open cell metallic foams characterized with the skeleton formed of convex or re-entrant cells. The re-entrant materials revealing negative Poisson’s ratio have attracted increasing attention in the context of modern materials applications, [3]. The goal of the presented investigations is to study the impact limits and absorption energy of these two kind of open cell metallic foams. To simulate the deformation processes the finite element program ABAQUS is used. The computer tomography made the basis for the formulation of computational model of the foam and the finite element discretization of the skeleton.
From each reconstructed volume, a representative cubic volume element was extracted. For numerical simulations the constitutive elasto-viscoplasticity model is applied that defines the dynamic behaviour of oxygen-free high conductivity (OFHC) Cu using the experimental data reported in the literature. The chosen material model for the numerical simulation is the Cowper-Symonds model. The model is able to predict the mechanical behaviour of the materials under different loading conditions and it is implemented in many FEM codes in order to investigate and describe problems such as ballistic impacts or problems in which the strain-rates component are relevant. In numerical simulations the bottom displacements in the impact direction are fixed and initial velocity V0 on the top surface and general contact (steel wall-Cu foam and selfcontact Cu foam) with the friction coefficient 0.35 is assumed. The numerical predictions of axial force (crushing force) within the wide range of velocity: from 50 to 300 m/s are discussed. The shock state variables derived from Hugoniot relation and the conservation laws are used for comparison with FEM simulations. Keywords: copper open-cell foams, compaction waves, shock waves, crushing force, elasto-viscoplasticity model | |
127. | Frąś L.J., Pęcherski R.B., DYNAMIC BEHAVIOUR OF MAGNETHOREOLOGICAL MATERIALS , MatCel’2017 & DynMatCel’2017, Cellular Materials: Structural Behaviour, Modelling and Characterisation, 2017-09-25/09-27, Aveiro (PT), pp.17-18, 2017Frąś L.J., Pęcherski R.B., DYNAMIC BEHAVIOUR OF MAGNETHOREOLOGICAL MATERIALS , MatCel’2017 & DynMatCel’2017, Cellular Materials: Structural Behaviour, Modelling and Characterisation, 2017-09-25/09-27, Aveiro (PT), pp.17-18, 2017Abstract: The magnethoreological material is based on the ferroparticles immersed in carrying fluid. The acting magnetic field is forcing ferroelements to connect into characteristic structure - braids. Behaviour of the magnethoreological material at the high strain rates will be described by Perzyna model. The created model will be verified with use of dedicated laboratory set up. Keywords: magnethoreological material, viscoplasticity model, dynamic behaviour, ferroelements. | |
128. | Chrzanowska J., Hoffman J., Mościcki T., Denis P., Szymański Z., Comparison of tungsten boride layers deposite by laser pulse, magnetron sputtering and combined magnetron sputtering-pulsed laser deposition, COLA 2017, International Conference on Laser Ablation, 2017-09-03/09-08, Marseille (FR), pp.202-202, 2017 | |
129. | Zawidzki M., Szklarski J., Single-branch Truss-Z Optimization Based on Image Processing and Evolution Strategy, PARENG2017, International Conference on Parallel, Distributed, Grid and Cloud Computing for Engineering, 2017-05-30/05-31, Pécs (HU), DOI: 10.4203/ccp.111.28, pp.28, 2017Zawidzki M., Szklarski J., Single-branch Truss-Z Optimization Based on Image Processing and Evolution Strategy, PARENG2017, International Conference on Parallel, Distributed, Grid and Cloud Computing for Engineering, 2017-05-30/05-31, Pécs (HU), DOI: 10.4203/ccp.111.28, pp.28, 2017Abstract: Truss-Z (TZ) is a skeletal system for creating free-form pedestrian ramps and ramp networks among any number of terminals in space. TZ structures are composed of four variations of a single basic unit subjected to affine transformations (mirror reflection, rotation and combination of both). This paper presents a new approach to the optimization of the layout of a singlebranch Truss-Z (STZ) in constrained environment (E). The problem is formulated as follows: create an STZ from a start (sP) to end point (eP) without self-intersections and collisions with two obstacles. This is a multi-criterial optimization problem where three independent objectives are subjected to minimization: the total number of modules (n), the “reaching error” to eP and the “overlapping error”. All three criteria are weighted and aggregated to a single cost function (CF). The calculation of CF is based on image processing of rendered geometry of individual STZs in E. The optimization is performed by population-based classic heuristic method - Evolution Strategy (ES). The computation of CF is the most time consuming, however, its parallelization is rather straightforward. Two parallelization methods are presented: distribution over Wolfram Lightweight Grid and application of general purpose graphical processing units (GPGPUs) with the use of CUDA platform. Keywords: Extremely Modular System, Truss-Z, discrete optimization, image processing, rasterization, GPU, CUDA, Mathematica, Wolfram Lightweight Grid. | |
130. | Zawidzki M., Szklarski J., Preliminary Optimization of Pipe-Z Reconfiguration, PARENG2017, International Conference on Parallel, Distributed, Grid and Cloud Computing for Engineering, 2017-05-30/05-31, Pécs (HU), DOI: 10.4203/ccp.111.27, pp.27, 2017Zawidzki M., Szklarski J., Preliminary Optimization of Pipe-Z Reconfiguration, PARENG2017, International Conference on Parallel, Distributed, Grid and Cloud Computing for Engineering, 2017-05-30/05-31, Pécs (HU), DOI: 10.4203/ccp.111.27, pp.27, 2017Abstract: Pipe-Z (PZ) is a parametric design system which comprised of a congruent modules (PZM) allows the creation of complex three-dimensional, single-branch structures which can be represented by mathematical knots. Once the geometrical parameters are set for the PZM, the shape of PZ is controlled solely by relative twists of the PZMs in a sequence. Therefore each PZM has one degree of freedom (1DOF). This paper presents the preliminary optimization of PZ reconfiguration from a “straight tube” to a half-torus. Here the displacement of PZMs transverse to the “bending direction” is to be minimized. In other words, it resembles “truing” of a wheel. In the considered case, the PZ is comprised of eight hexagonal PZMs. Thus every PZM can have six possible positions relative to the previous module. The initial (PZI) and target (PZT) configurations are given. Since the time-steps and relative twists are discrete, it is a discrete optimization and has combinatorial nature. The number of possible configurations grows astronomically with the assumed number of time-steps from one position to another and the number of PZMs. However, the optimization algorithm can be naturally parallelized. At first the concept of PZ is outlined, followed by the experiment. The results are illustrated and discussed. Keywords: Extremely Modular System, Pipe-Z, Arm-Z, discrete optimization, dihedral rotation, “snakebot”, reconfiguration. | |
131. | Secomski W., Wójcik J., Klimonda Z., Nowicki A., Estimation and Measurement of the Streaming Velocity in Presence of the Contrast Agents or Blood Mimicking Scatterers, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), DOI: 10.1109/ULTSYM.2017.8092858, pp.1-4, 2017Secomski W., Wójcik J., Klimonda Z., Nowicki A., Estimation and Measurement of the Streaming Velocity in Presence of the Contrast Agents or Blood Mimicking Scatterers, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), DOI: 10.1109/ULTSYM.2017.8092858, pp.1-4, 2017Abstract: Streaming velocity mainly depends on the intensity and absorption of ultrasound in the media. For high frequencies exceeding 20 MHz the speed of streaming in blood is also affected by scattering effects on the blood cells and contrast agent microbubbles. According to theoretical calculations, 12.2 % increase in streaming velocity for 1 g/l starch concentration rise should be expected. The theory has also shown the reduction of the streaming velocity by low-density scatterers, estimated decrease was -9.7 % for BR14 contrast agent. The experimental measurements of streaming velocities were done in blood mimicking fluid and Bracco BR14 microbubbles dissolved in water. The streaming was generated by a plane 20 MHz ultrasonic transducer driven by a pulsed Doppler flowmeter. For starch concentration changing from 0.01g/l (reference fluid) up to 1g/l the streaming velocity increased by 13%, very close to the theoretical prediction. For BR14, the measured velocity was 9% less than in reference fluid and remained independent on the microbubbles concentration. Keywords: streaming; radiation force; starch; contrast agent; blood | |
132. | Żołek N., Wójcik J., Optimized Acoustic Echoes Simulator in Fourier domain, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), DOI: 10.1109/ULTSYM.2017.8092654, pp.1-3, 2017Żołek N., Wójcik J., Optimized Acoustic Echoes Simulator in Fourier domain, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), DOI: 10.1109/ULTSYM.2017.8092654, pp.1-3, 2017Abstract: A new toolbox for the simulation of acoustic wave fields is described. The toolbox, USim, is designed to make an acoustic modeling of ultrasound propagation in tissues reliable and fast. The forward simulations of the wave field are based on the Born-Neumann single scattering approximation of the solution of Sturm-Liouville equation. The toolbox allows simulating the ultrasound wave propagation in non-homogeneous media containing finite size scatterers similar to those existing in a real tissues. The approach of calculations conducted in Fourier space increases the efficiency and allows taking into account the absorption and density phenomena in a simple and correct way. Keywords: acoustic propagation; numerical simulations; fourier domain | |
133. | Secomski W., POMIARY POLA AKUSTYCZNEGO, XXIII Seminarium NIENISZCZĄCE BADANIA MATERIAŁÓW, 2017-03-15/03-17, Zakopane (PL), pp.139-146, 2017 | |
134. | Kowalczyk P., Parametric Constitutive Modelling of Cancellous Bone, IAMMC 2017, Interaction of Applied Mathematics and Mechanics Conference, 2017-05-09/05-11, Paris (FR), pp.11-12, 2017 | |
135. | Burczyński T., Topology Optimization In Nano-Scale - New Graphene-Like Materials, IAMMC 2017, Interaction of Applied Mathematics and Mechanics Conference, 2017-05-09/05-11, Paris (FR), pp.13-13, 2017 | |
136. | Rojek J., Multiscale Modelling of Powder Sintering, IAMMC 2017, Interaction of Applied Mathematics and Mechanics Conference, 2017-05-09/05-11, Paris (FR), pp.21-22, 2017 | |
137. | Konowrocki R., Dąbrowski A., Wantoch-Rekowski R., Brona P., Modelling of special train dynamic for construction simulator to train drivers training , ART 2017, 6th International Scientific Conference - ADVANCED RAIL TECHNOLOGIES - , 2017-11-15/11-16, Conference venue: Hotel Boss, Żwanowiecka 20, Warsaw. (PL), pp.10-11, 2017Konowrocki R., Dąbrowski A., Wantoch-Rekowski R., Brona P., Modelling of special train dynamic for construction simulator to train drivers training , ART 2017, 6th International Scientific Conference - ADVANCED RAIL TECHNOLOGIES - , 2017-11-15/11-16, Conference venue: Hotel Boss, Żwanowiecka 20, Warsaw. (PL), pp.10-11, 2017Abstract: Due to the fact that training simulators of railway vehicles must fulfill unique requirements resulting from the specific properties of the simulated vehicles, in this article on determining the main criteria for modeling the dynamics of such systems was presented. A methodology used in the study on the selection of parameters of the modeled vehicle and its driveline based on experimental studies was described. Adaptation of parameters obtained from the experimentally test into the dynamics model of vehicle was presented. Currently used solutions in simulators as well as issues related to animation and presentation of the image was provided. The requirements for the operation of the rail vehicle simulator, as well the design requirements for visualization of the image were defined and discussed Keywords: railway vehicle simulator, railway vehicle drive system, virtual environment VBS3 | |
138. | Konowrocki R., Kukulski J., Groll W., Walczak S., Influence of material property for friction pairs of the braking systems of a high-speed train on generation hot spots
, ART 2017, 6th International Scientific Conference - ADVANCED RAIL TECHNOLOGIES - , 2017-11-15/11-16, Conference venue: Hotel Boss, Żwanowiecka 20, Warsaw. (PL), pp.48-49, 2017Konowrocki R., Kukulski J., Groll W., Walczak S., Influence of material property for friction pairs of the braking systems of a high-speed train on generation hot spots
, ART 2017, 6th International Scientific Conference - ADVANCED RAIL TECHNOLOGIES - , 2017-11-15/11-16, Conference venue: Hotel Boss, Żwanowiecka 20, Warsaw. (PL), pp.48-49, 2017Abstract: A braking systems during friction interaction convert mechanical energy into heat energy. The corresponding heating is a major design parameter as it influences the tribological and mechanical performances (wear of the materials, friction performances, risks of cracks, vibrations, etc.). During breaking process in such breaking systems, different locations of thermal overheating areas of material of friction pair may occur, usually named as hot spots or hot bands. These spot and bands are characterized by very high temperature gradients. This brake systems exposed to thermoelastic instabilities show a characteristic temperature distribution on break disc surface that can lead to local material change. The interaction of thermal energy and thermal expansion of the material of the friction braking effect on the local increase in temperature leading to a dominant impact frictional forces in this area. Often destabilization of the braking process is a consequence of such a rise in temperature. The difficulty of understanding and modeling all of these phenomena still remains due to the complex interactions of thermal, mechanical, and tribological effects. Experimental investigation is still nowadays a major instrument for detecting and understanding the physical effects. In this presentation, we propose to consider an example Keywords: braking system, hot spots, hot bands, braking tests, infrared testing | |
139. | Konowrocki R., Stability analysis of the railway vehicle drive with electromechanical coupling effects
, ART 2017, 6th International Scientific Conference - ADVANCED RAIL TECHNOLOGIES - , 2017-11-15/11-16, Conference venue: Hotel Boss, Żwanowiecka 20, Warsaw. (PL), pp.22-23, 2017Konowrocki R., Stability analysis of the railway vehicle drive with electromechanical coupling effects
, ART 2017, 6th International Scientific Conference - ADVANCED RAIL TECHNOLOGIES - , 2017-11-15/11-16, Conference venue: Hotel Boss, Żwanowiecka 20, Warsaw. (PL), pp.22-23, 2017Abstract: Aiming at the torsional vibration in the electromechanical driveline system for railway trains, this article introduces a stability analysis of the drive system with electromechanically coupling. For a reliability and security of drive system of railway vehicles drive by electric motors, the electromagnetic output traction force and torques should drive stably, otherwise the shaft train vibration caused by motor torque ripple will affect the fatigue life of the device and the operation security of the driven object. For this reason an investigation of the dynamic response and stability of a electromechanical drive train system was done. For this purpose a dynamic model integrated with an electric motor to simulate the vibration in the component parts of the drive system were created. Such an approach for modelling of the considered electrical drive systems coupled with elements of a driven vehicle is particularly important when the purpose of such modelling is to obtain an information about the transient phenomena of system operation
Keywords: electromechanical coupling, electric drive, electric motor, torsion vibrations, railway drive | |
140. | Chrzanowska J., Błoński S., Hoffman J., Małolepszy A.G., Stobiński L.A., Trykowski G., Szymański Z., Carbon nanoparticles synthesized by the laser ablation in liquid, COLA 2017, International Conference on Laser Ablation, 2017-09-03/09-08, Marseille (FR), pp.286-286, 2017 | |
141. | Mościcki T., Hoffman J., Szymański Z., Expansion of laser-ablated carbon plume to ambient argon, PLASMA-2017, International Conference on Research and Applications of Plasmas, 2017-09-18/09-22, Warszawa (PL), pp.50-50, 2017Mościcki T., Hoffman J., Szymański Z., Expansion of laser-ablated carbon plume to ambient argon, PLASMA-2017, International Conference on Research and Applications of Plasmas, 2017-09-18/09-22, Warszawa (PL), pp.50-50, 2017Keywords: laser ablation, plasma plume | |
142. | Pawłowska S., Pierini F., Nakielski P., Piechocka I., Zembrzycki K., Kowalewski T.A., Lateral Migration of Highly Deformable Nanofilaments Conveyed by Oscillatory Flow, CNM, 5th Conference on Nano- and Micromechanics, 2017-07-04/07-06, Wrocław (PL), pp.29-31, 2017Pawłowska S., Pierini F., Nakielski P., Piechocka I., Zembrzycki K., Kowalewski T.A., Lateral Migration of Highly Deformable Nanofilaments Conveyed by Oscillatory Flow, CNM, 5th Conference on Nano- and Micromechanics, 2017-07-04/07-06, Wrocław (PL), pp.29-31, 2017Keywords: thermal fluctuations, lateral migration, flexible filaments | |
143. | Pawłowska S., Kowalewski T.A., Lateral migration of solid spheroidal nanoparticles and highly deformable hydrogel nanofilaments under the influence of oscillatory flow, ExFM2017, Experiments in Fluid Mechanics, 2017-10-23/10-24, Warszawa (PL), pp.1-2, 2017 | |
144. | Pęcherski R.B., Deformacja metali z udziałem wielopoziomowej hierarchii pasm ścinania - nowe spojrzenie.
Deformation of metals accounting for multilevel hierarchy of shear bands - revisited. , OMIS'2017, XII Konferencja NAukowa ODKSZTAŁCALNOŚĆ METALI I STOPÓW, 2017-11-21/11-24, Łańcut (PL), pp.52-53, 2017Pęcherski R.B., Deformacja metali z udziałem wielopoziomowej hierarchii pasm ścinania - nowe spojrzenie.
Deformation of metals accounting for multilevel hierarchy of shear bands - revisited. , OMIS'2017, XII Konferencja NAukowa ODKSZTAŁCALNOŚĆ METALI I STOPÓW, 2017-11-21/11-24, Łańcut (PL), pp.52-53, 2017Abstract: Obserwacje doświadczalne wykazują, że deformacja plastyczna metali jest często efektem konkurujących ze sobą mechanizmów krystalograficznych poślizgów, bliźniakowania oraz mikropasm ścinania. Te ostatnie przejawiają się jako koncentracje odkształcenia postaciowego w formie cienkich transkrystalicznych warstewek o grubości rzędu 0,1 µm. Mikropasma ścinania współdziałają z aktywnymi mechanizmami krystalograficznego poślizgu lub bliźniakowania, kontrolując w różnym stopniu proces plastycznej deformacji. Na podstawie analizy aktualnego stanu badań prowadzonych na różnych poziomach obserwacji: wspomagane cyfrową korelacją obrazu badania mechaniczne – próby jedno- i dwuosiowe, badania in-situ przy użyciu mikroskopii elektronowej, badania tomografii atomowej w połączeniu z obliczeniami ab initio oraz dynamiki molekularnej, zaproponowano fizyczny obraz wielopoziomowej hierarchii oraz ewolucji pasm ścinania. Przedstawiono motywację fizykalną i heurystyczne podstawy opisu teoretycznego. Odniesiono się do znanych wyników z literatury, [2]. Przedyskutowano trudności z zastosowaniem prostego wielkoskalowego sposobu uśredniania oraz oryginalną koncepcję rozszerzenia pojęcia reprezentatywnego elementu objętości z wykorzystaniem znanej teorii propagacji powierzchni osobliwych jako fal silnej nieciągłości mikroskopowego pola prędkości. Przedstawiono nowe sformułowanie opisu prędkości odkształcenia postaciowego generowanego przez wielopoziomową hierarchię pasm ścinania z uwzględnieniem decyzyjnego procesu wyboru kluczowych efektów przepływu informacji dla poszczególnych poziomów obserwacji.
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Experimental observations show that plastic deformation of metals is often produced as an effect of competing mechanisms of crystallographic glide, twinning and micro-shear banding. The micro-shear bands are observed as concentrated shear zones in the form of trans crystalline layers of the thickness of the order 0.1 µm. They cooperate with active mechanisms of crystallographic glide and/or twinning controlling to various degrees process of plastic flow. It has been observed that the change of the mechanism of plastic deformation has strong influence on mechanical properties of material under consideration. Therefore, the identification and elucidation of physical mechanisms that are responsible for initiation, growth and evolution of micro-shear bands is of fundamental importance for understanding the macroscopic behaviour of metallic materials. Basing on the analysis of recent state of the art of the investigations carried on different levels of observations: uni-axial and bi-axial mechanical tests enhanced with digital image correlation method, in-situ tests with use of electron microscopy, atom probe tomography in relation with ab initio and molecular dynamics computational simulations, certain physical model of multilevel hierarchy and evolution of shear bands is proposed. Physical motivation and heuristic foundations of theoretical description are discussed with reference to known results in the literature, [2]. The difficulties with application of a direct multiscale integration scheme are discussed and an original idea of an extension of the representative volume element concept with use of the known theory of the propagation of the singular surfaces of microscopic velocity field is proposed. A new formulation of the description of rate of shear strain generated by multilevel hierarchy of shear bands is formulated in the workflow integration approach, in which information from molecular simulation at different levels flows into the decision process. Keywords: pasma ścinania, hierarchia pasm ścinania, powierzchnia osobliwa, cyfrowa korelacja obrazu (DIC)
shear bands, multilevel hierarchy of shear bands, singulatity surface, digital image correlation (DIC) | |
145. | Golasiński K., Pieczyska E., Staszczak M., Cristea M., EXPERIMENTAL INVESTIGATION OF THERMOMECHANICAL PROPERTIES OF MULTIFUNCTIONAL MATERIALS AT IPPT PAN, MACRO Iasi, The XXVI-th Symposium PROGRESS IN ORGANIC AND POLYMER CHEMISTRY, 2017-10-05/10-06, Romanian Academy, Iasi (RO), pp.1-1, 2017 | |
146. | Golasiński K.M., Pieczyska E.A., Maj M., Staszczak M., Takesue N., Unique mechanical performance of an innovative Ti-based superalloy Gum Metal under compression, International Scientific Conference Humboldt-Kolleg Limits of Knowledge, 2017-06-22/06-25, University of Sciences & Technology, Cracow (PL), No.P35-NS, pp.218-219, 2017 | |
147. | Brzozowski B., Kaźmierczak K.^{♦}, Magnetic field mapping as a support for UAV indoor navigation system, Proceedings of 4th IEEE International Workshop on Metrology for Aerospace, 2017-06-21/06-23, Paduna (IT), DOI: 10.1109/MetroAeroSpace.2017.7999535, pp.583-588, 2017Brzozowski B., Kaźmierczak K.^{♦}, Magnetic field mapping as a support for UAV indoor navigation system, Proceedings of 4th IEEE International Workshop on Metrology for Aerospace, 2017-06-21/06-23, Paduna (IT), DOI: 10.1109/MetroAeroSpace.2017.7999535, pp.583-588, 2017Abstract: Safe indoor flights of unmanned aerial vehicles (UAVs) requires an independent measurement systems, that will enable efficient navigation in the absence of GPS data. One of the many solutions currently being developed is the use of information about changes in the value of the local magnetic field. This paper presents ways of recording, visualizing and mapping local magnetic field changes that can be used as a support for indoor navigation systems. At the beginning we reviewed devices for acquisition of magnetic field strength and the type of data being recorded. In the next step we analyzed the possibilities of visualization of acquired data. Finally the methods used to generate magnetic field maps of enclosed areas have been presented. In each of the aspects covered in this paper, solutions developed by the authors will be described.
Keywords: Magnetic field, Position estimation, UAV, Indoor Navigation, Avionics. | |
148. | Bogacz R., Konowrocki R., Influence of track defects on railway vehicle damage - O wpływie usterek toru na uszkodzenia pojazdów szynowych, SITK207, Nowoczesne technologie i systemy zarządzania w transporcie szynowym. Część I: DROGA KOLEJOWA., 2017-11-29/12-02, Zakopane Hotel Mercure KASPROWY ZAKOPANE (PL), pp.21-28, 2017Bogacz R., Konowrocki R., Influence of track defects on railway vehicle damage - O wpływie usterek toru na uszkodzenia pojazdów szynowych, SITK207, Nowoczesne technologie i systemy zarządzania w transporcie szynowym. Część I: DROGA KOLEJOWA., 2017-11-29/12-02, Zakopane Hotel Mercure KASPROWY ZAKOPANE (PL), pp.21-28, 2017Abstract: The paper contain description of certain dynamical problems connected with the kinematic excitation of railway track. Some phenomena are given which may create high loads, track degradation and fatigue of wheelset axles. An alternative approach to measurement rail vehicle overload are given. Some examples of experimental investigations are given which pointed out that the dynamical load acting on the track can be a few times higher as the static load. In the paper the results obtained from the electromechanical drive model describing the torsion vibration of wheelset caused by passing through gaps in a single rail of track are presented. Keywords: wheel-rail dynamics, vehicle-track interaction, track and vehicle degradation | |
149. | Basista M., Micro-CT based numerical modeling of residual stresses and fracture in metal-ceramic composites, 13TH NATIONAL CONGRESS ON THEORETICAL AND APPLIED MECHANICS, 2017-09-06/09-10, Sofia, Institute of Mechanics, Bulgarian Academy of Sciences (BG), pp.1-1, 2017 | |
150. | Marijnissen M.J., Graczykowski C., Rojek J., Two-stage method for the simulation of the comminution process in a high-speed beater mill, MEC-2017, MINERAL ENGINEERING CONFERENCE, 2017-09-20/09-23, Wisła (PL), DOI: 10.1051/e3sconf/20171801011, No.18, pp.1-7, 2017Marijnissen M.J., Graczykowski C., Rojek J., Two-stage method for the simulation of the comminution process in a high-speed beater mill, MEC-2017, MINERAL ENGINEERING CONFERENCE, 2017-09-20/09-23, Wisła (PL), DOI: 10.1051/e3sconf/20171801011, No.18, pp.1-7, 2017Abstract: The paper presents a two-stage simplified method for the simulation of comminution process which takes place in a beater mill. The first stage of the proposed method is a simulation of the flow of gas and ore particles through a mill based on a two-phase continuous-discrete model. It allows to capture the interaction between the fluid flow and embedded particles, to determine trajectories of their motion and average velocities and frequencies of their collisions against the flywheel and the mill’s walls. The second stage of the proposed method is a discrete element method simulation of the process of comminution of a single ore particle. It allows to determine the size distribution of created smaller particles in terms of normal velocity and angle of impact and to estimate the global efficiency of the comminution process. The proposed simulation methodology is applied for the verification of the innovative concept of the pplication of high–speed beater mill for the comminution of the copper ore. | |
151. | Dera W., Dziekoński C., Jarząbek D.M., Lateral force calibration in atomic force microscope using MEMS microforce sensor, EUROMAT 2017 , European Congress and Exhibition on Advanced Materials and Processes, 2017-09-17/09-22, Thessaloniki (GR), pp.1, 2017 | |
152. | Dziekoński C., Jarząbek D.M., Dera W., Influence of mode of electrodeposition, grain size on mechanical propertice of electrodeposited nanocrystaline nickel coatings., EUROMAT 2017 , European Congress and Exhibition on Advanced Materials and Processes, 2017-09-17/09-22, Thessaloniki (GR), pp.38-38, 2017 | |
153. | Dera W., Dziekoński C., Jarząbek D.M., Method for lateral force calibration in atomic force microscope using MEMS microforce sensor. , 8TH International Colloquium Micro-Tribology, 2017-09-11/09-13, Warszawa (PL), pp.1, 2017 | |
154. | Jarząbek D.M., Dziekoński C., Chmielewski M., Effect of metal coatings on the interfacial bonding strength of ceramics to copper in sintered Cu-SiC composites., EUROMAT 2017 , European Congress and Exhibition on Advanced Materials and Processes, 2017-09-17/09-22, Thessaloniki (GR), pp.17-17, 2017 | |
155. | Frąś L.J., Dziekoński C., Dera W., Jarząbek D.M., The anisotrophy of viscosity of magnetorheological fluid., 8TH International Colloquium Micro-Tribology, 2017-09-11/09-13, Warszawa (PL), pp.1, 2017 | |
156. | Jarząbek D.M., Dziekoński C., Chmielewski M., Measurement of adhesion between ceramics and copper in sintered Cu-SiC composites., 8TH International Colloquium Micro-Tribology, 2017-09-11/09-13, Warszawa (PL), pp.1, 2017 | |
157. | Ekiel-Jeżewska M.L., Bukowicki M., Hydrodynamic and elastic interactions of sedimenting flexible fibers, Bulletin of the American Physical Society, ISSN: 0003-0503, Vol.62, No.14, pp.221-221, 2017 | |
158. | Szolc T., On dynamics and stability of the automotive engine turbocharger rotor supported by the electrodynamic passive magnetic bearings, SiRM - 2017, Schwingungen in rotierenden Maschinen - 2017, 2017-02-15/02-17, Graz (AT), DOI: 10.24352/UB.OVGU-2017-103, No.S16-1, pp.268-279, 2017Szolc T., On dynamics and stability of the automotive engine turbocharger rotor supported by the electrodynamic passive magnetic bearings, SiRM - 2017, Schwingungen in rotierenden Maschinen - 2017, 2017-02-15/02-17, Graz (AT), DOI: 10.24352/UB.OVGU-2017-103, No.S16-1, pp.268-279, 2017Abstract: In the paper dynamic investigations on the automotive turbocharger rotor-shaft supported on the electro-dynamic passive magnetic bearings (EDPMB) and on the traditional floating-ring journal bearings have been carried out using a computer model. The results of computations obtained for the two mutually compared kinds of suspension are demonstrated in the form of Campbell diagrams and amplitude-frequency characteristics. Here, the main attention is focused on resonant-free operation ability assured by the support on the EDPMBs. Moreover, conditions of stability for the support on the journal bearings and on the EDPMBs have been investigated by means of the eigenvalue analysis. There is studied an influence of skew-symmetrical dynamic properties of the both kinds of rotor-shaft suspensions caused by the bearing stiffness negative cross-coupling terms as well as by the gyroscopic effects which are particularly severe at turbocharger high rotational speeds. Keywords: turbocharger rotor, electrodynamic passive magnetic bearings, rotor dynamics, stability analysis | |
159. | Konowrocki R., Szolc T., An influence of electromechanical coupling effects on stability of the drive systems of machines and railway vehicles driven by electric motors, XXV French-Polish Seminar on Mechanics, 2017-05-15/05-16, Bourges (FR), pp.32-32, 2017Konowrocki R., Szolc T., An influence of electromechanical coupling effects on stability of the drive systems of machines and railway vehicles driven by electric motors, XXV French-Polish Seminar on Mechanics, 2017-05-15/05-16, Bourges (FR), pp.32-32, 2017Abstract: To ensure a reliability and unconditional security of drive system of machine and railway vehicles drive by electric motors, the electromagnetic output traction force and torques should drive stably, otherwise the shaft train vibration caused by motor torque ripple will affect the fatigue life of the device and the operation security of the driven object. For this reason an investigation of the dynamic response and stability of a electromechanical drive train system was done. The obtained results have demonstrated that the electromagnetic transient processes generated in the electric motor should be taken into account for the use of the assessing the stability of the system.
The knowledge about stability of drive transmission systems of machines and railway vehicles is of a great importance in the field of dynamics and material fatigue of the mechanical systems.
Keywords: electric motor, torsional vibrations, electromechanical coupling, wheel-rail adhesion, wheelset drivetrain dynamic | |
160. | Kiełczyński P., Szalewski M., Balcerzak A., Wieja K., Ptasznik S., Rostocki A.J., Investigation of regular and anomalous behavior of liquid media under high pressure using ultrasonic methods, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), pp.1-4, 2017Kiełczyński P., Szalewski M., Balcerzak A., Wieja K., Ptasznik S., Rostocki A.J., Investigation of regular and anomalous behavior of liquid media under high pressure using ultrasonic methods, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), pp.1-4, 2017Abstract: In many industrial technological processes, liquids are subjected to high pressures, e.g., in the high pressure food preservation. Similarly, in modern fuel injection systems for diesel engines, biofuel is subjected to a pressure up to 300 MPa. In such conditions, in liquids, high-pressure phase transitions (solidification) can occur that substantially increase the density and liquid viscosity. This solidification can result in significant problems with engine failure under cold-start conditions. This is an evident recipe for disaster, since the engine and its accessories would be very likely quickly destroyed. Thus, it is important to determine at what pressures and temperatures phase transitions occur. Conventional mechanical methods for measuring physicochemical properties of liquids at these extreme conditions do not operate. By contrast, ultrasonic techniques are very suitable for measurements of hysicochemical properties of liquids at high pressure, since they are non-destructive, can be fully automated and are characterized by the absence of moving parts. The aim of this work is to study the high-pressure hysicochemical properties of liquids (exemplified by a Camelina sativa - false flax oil) using novel ultrasonic methods. Keywords: pressure; ultrasonic methods; phase transitions; Camelina sativa | |
161. | Kiełczyński P., Szalewski M., Balcerzak A., Wieja K., The influence of rheological parameters of viscoelastic liquids on the propagation characteristics of ultrasonic
Love waves, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), pp.1-4, 2017Kiełczyński P., Szalewski M., Balcerzak A., Wieja K., The influence of rheological parameters of viscoelastic liquids on the propagation characteristics of ultrasonic
Love waves, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), pp.1-4, 2017Abstract: Progress in materials science has led to development of new materials with improved functional characteristics. One of the new types of materials introduced into industrial practice are plastics and polymers. These materials exhibit rheological (viscoelastic) properties, which combine simultaneously the properties of liquids and solids. Due to their attractive features, such as low specific weight, high resistance to chemical agents, ease of processing, cost ffectiveness etc. these materials are widely used in chemical, automotive, aviation and space industry. In addition, these materials are very common in many aspects of everyday life. Thus, it is very important, both from the theoretical and practical point of view, to develop new, robust and accurate methods to measure the rheological parameters (viscosity η, elasticity μ and density ρ) of plastics and polymers. The conventional mechanical methods used so far to this end are outdated, time consuming, and cumbersome. Ultrasonic methods do not possess these disadvantages. The first step in the formulation of the Inverse Method for evaluating the rheological parameters of viscoelastic liquids is to formulate and solve the Direct Sturm-Liouville Problem for Love waves propagating in the investigated layered elastic aveguide loaded on its surface with various types of viscoelastic materials (e.g., liquids). The aim of this study is to develop a rigorous mathematical model (Direct Sturm-Liouville Problem) of propagation of shear horizontal (SH) surface Love waves in layered viscoelastic structures, i.e., in layered elastic waveguides with a guiding surface layer covered with a viscoelastic material described by Kelvin-Voigt, Newton and Maxwell viscoelastic models respectively Keywords: Love waves; viscoelastic liquid; Sturm-Liouville problem; dispersion curves | |
162. | Witecka A., Yamamoto A., Święszkowski W.^{♦}, Basista M., Influence of polymer film concentration on cytocompatibility and corrosion suppression of ZM21 magnesium alloy, 7th KMM-VIN Industrial Workshop “Biomaterials: Key Technologies for Better Healthcare”, 2017-09-27/09-28, Erlangen (DE), pp.1-1, 2017 | |
163. | Pieczyska E.A., Kowalewski Z.L., Dunic V.Lj., Stress Relaxation Effects in TiNi SMA During Superelastic Deformation: Experiment and Constitutive Model, SHAPE MEMORY and SUPERELASTICITY, ISSN: 2199-384X, DOI: 10.1007/s40830-017-0123-2, No.40830, pp.1-11, 2017Pieczyska E.A., Kowalewski Z.L., Dunic V.Lj., Stress Relaxation Effects in TiNi SMA During Superelastic Deformation: Experiment and Constitutive Model, SHAPE MEMORY and SUPERELASTICITY, ISSN: 2199-384X, DOI: 10.1007/s40830-017-0123-2, No.40830, pp.1-11, 2017Abstract: This paper presents an investigation of thermomechanical effects related to the phenomena of stress relaxation occurring in TiNi SMA subjected to modified program of displacement-controlled tension. The deformation data were taken from testing machine, whereas the temperature changes accompanying the exothermic/endothermic martensite forward/reverse transformation were measured by infrared camera. At the advanced stages of the transformations, the strain was kept constant for a few minutes and the SMA load and temperature were recorded continuously. As a consequence, the stress and temperature changed significantly during the loading stops. A large stress drop, caused by the transformation, was observed during the relaxation stage in both courses of the SMA loading and unloading. Moreover, the non-uniform temperature distribution, reflecting macroscopically inhomogeneous transformation, lapsed while the strain was kept constant, yet restarted at the end of the relaxation stop and developed at the reloading stage. Along with the experimental results, the mechanical and thermal responses induced by the transformation were obtained by 3D coupled thermomechanical numerical analysis, realized in partitioned approach. Latent heat production was correlated with an amount of the martensitic volume fraction. The stress and temperature drops recorded during the experiment were satisfactorily reproduced by the model proposed for the SMA thermomechanical coupling Keywords: TiNi shape memory alloy, Superelasticity, Stress relaxation, Temperature change, Thermomechanical couplings, 3-D model | |
164. | Nowak Z., Pęcherski R.B., Maj P., Niestabilność plastycznego płynięcia w stopie Inconel 718. Badania doświadczalne
Serrated flow in Inconel 718 alloy. Experimental investigations
, OMIS'2017, XII Konferencja NAukowa ODKSZTAŁCALNOŚĆ METALI I STOPÓW, 2017-11-21/11-24, Łańcut (PL), pp.47-48, 2017Nowak Z., Pęcherski R.B., Maj P., Niestabilność plastycznego płynięcia w stopie Inconel 718. Badania doświadczalne
Serrated flow in Inconel 718 alloy. Experimental investigations
, OMIS'2017, XII Konferencja NAukowa ODKSZTAŁCALNOŚĆ METALI I STOPÓW, 2017-11-21/11-24, Łańcut (PL), pp.47-48, 2017Abstract: Badania doświadczalne efektu Portevin - Le Chatelier w Inconelu 718 przeprowadzono na płaskich próbkach. Do pomiarów zastosowano metodę cyfrowej korelacji obrazu (DIC), która jest efektywna i praktyczna dzięki bezkontaktowym pomiarom i dużej dokładności w ustalaniu charakterystycznych cech przestrzenno-czasowych deformacji próbki. Określenie takich cech zlokalizowanych pasm ścinania jest konieczne do zaproponowania modelu konstytutywnego dla metali wykazujących ten typ plastycznej niestabilności. Opracowany model konstytutywny pozwoli na numeryczne symulacje w pełnej skali 3D fizycznych testów z użyciem programu ABAQUS. Głównym celem pracy jest przedstawienie możliwości wykorzystania pomiarów uzyskanych techniką cyfrowej korelacji obrazu do wykrywania i charakteryzowania przestrzenno-czasowych cech efektu PLC w dostępnym komercyjnie stopie Inconel 718.
An experimental investigation of the Portevin–Le Chatelier effect in the Inconel 718 alloy is undertaken in this study through flat specimen geometries. Measurements based on digital image correlation (DIC) is an effective and practical optical technique due to the advantages of easy operation, non-contact, full field optical measurement, high accuracy and high computational efficiency for investigating the PLC effect and its spatio-temporal characteristics. The localization band characteristics are required to develop the constitutive relations for metals exhibiting this type of plastic instability, based on available material tests. The constitutive model can be used in full-scale 3D numerical simulations of the physical tests using the explicit solver of the finite element code ABAQUS. The objective of this paper is to show how DIC techniques are readily able to detect and characterize spatio-temporal features of the PLC behaviour of a commercial available Inconel 718 alloy. Keywords: stop Inconel 718, efekt Portevin-Le Chatelier, cyfrowa korelacja obrazu,
Inconel 718 alloy, Portevin-Le Chatelier effect, Digital Image Correlation (DIC) | |
165. | Olaszek P., Świercz A., Sala D.^{♦}, Kokot M., System monitorowania łukowego wiaduktu kolejowego na linii wysokiej prędkości, WDM'17, WROCŁAWSKIE DNI MOSTOWE - Mosty. Przemiany w projektowaniu i technologiach budowy, 2017-11-28/11-29, Wrocław (PL), pp.481-488, 2017Olaszek P., Świercz A., Sala D.^{♦}, Kokot M., System monitorowania łukowego wiaduktu kolejowego na linii wysokiej prędkości, WDM'17, WROCŁAWSKIE DNI MOSTOWE - Mosty. Przemiany w projektowaniu i technologiach budowy, 2017-11-28/11-29, Wrocław (PL), pp.481-488, 2017Abstract: The article presents the railway bridge structures monitoring system, which takes advantage of the
dynamic response measurement and evaluation method. The monitoring system is focused on steel
structures with the spans exceeding 30 m. The elaboration of the method which uses inclinometers
together with an accelerometer for indirect displacement measurement under the dynamic load is the
main achievement of the project. Keywords: monitoring, railway bridges, inclinometer, accelerometer | |
166. | Węglewski W., Basista M., Bochenek K., THE INFLUENCE OF MICROSTRUCTURE ON THERMAL RESIDUAL STRESS AND FRACTURE TOUGHNESS OF NICKEL ALUMINIDE-ALUMINA COMPOSITES – EXPERIMENT AND NUMERICAL MODEL, ECerS2017, 15th Conference & Exhibition of the European Ceramic Society, Budapest, 2017-07-09/07-13, Budapest (HU), No.357, pp.1-1, 2017 | |
167. | Basista M., Micro-CT based modeling of residual stresses and crack propagation in metalceramic composites, 21. Symposium Verbundwerkstoffe und Werkstoffverbunde, 2017-07-05/07-07, Bremen (DE), pp.1-1, 2017 | |
168. | Postek E., Sadowski T., Impact Models of WC-Co Composite, CERMODEL 2017Modelling and Simulation Meet Innovation in Ceramics Technology, 2017-07-26/07-28, Trento (IT), pp.1-1, 2017 | |
169. | Bochenek K., Basista M., Morgiel J., Węglewski W., Towards the improvement of fracture toughness of NiAl intermetallics for aerospace applications, ICCE‐25, 25th Annual International Conference on Composites or Nano Engineering, 2017-07-16/07-22, Rome (IT), pp.1-2, 2017 | |
170. | Mikułowski G., Suwała G., Knap L., Holicki-Szulc J., Adaptive techniques for suppresion of forced vibrations, SMART 2017, 8th Conference on Smart Structures and Materials, 2017-06-05/06-08, Madrid (ES), pp.166-175, 2017Mikułowski G., Suwała G., Knap L., Holicki-Szulc J., Adaptive techniques for suppresion of forced vibrations, SMART 2017, 8th Conference on Smart Structures and Materials, 2017-06-05/06-08, Madrid (ES), pp.166-175, 2017Abstract: Adaptive structures, equipped with so-called structural fuses (based on fast
responding piezo-devices), able to connect/disconnect instantly selected structural interface,
allows effective protection against resonance induction via externally forced vibrations. The
presented case study demonstrates haw forced vibrations with modifiable frequencies can be
smoothly received, if structural fuses are properly activated/deactivated when the external
excitation approaches the structural eigen frequencies. Keywords: Adaptive structures, forced vibrations, avoiding resonance, structural fuses | |
171. | Chikahiro Y., Ario I., Adachi K., Shimizu S., Pawłowski P.^{♦}, Graczykowski C.^{♦}, Holnicki-Szulc J., FUNDAMENTAL STUDY ON DYNAMIC PROPERTY OF DEPLOYABLE EMERGENCY BRIDGE USING SCISSORS MECHANISM, Footbridge Berlin 2017, 6th International Footbridge Conference, 2017-09-06/09-08, TU Berlin (DE), DOI: 10.24904/footbridge2017.09352, pp.1-6, 2017Chikahiro Y., Ario I., Adachi K., Shimizu S., Pawłowski P.^{♦}, Graczykowski C.^{♦}, Holnicki-Szulc J., FUNDAMENTAL STUDY ON DYNAMIC PROPERTY OF DEPLOYABLE EMERGENCY BRIDGE USING SCISSORS MECHANISM, Footbridge Berlin 2017, 6th International Footbridge Conference, 2017-09-06/09-08, TU Berlin (DE), DOI: 10.24904/footbridge2017.09352, pp.1-6, 2017Abstract: The paper presents a new type of emergency bridge, which can be quickly constructed in case of damages
after a natural disaster. The concept of the bridge is based on the application of scissor-type mechanism,
which provides its rapid deployment. In case of deployable structures apart from static analysis of different
configurations of expansion, it is very important to investigate the dynamic behavior of the system. High compliance and flexibility of the scissors-type bridge may influence user's comfort and safety in case of heavy dynamic loads such as human induced impacts, wind gusts or earthquakes. Up to now, the authors constructed several types of the experimental MBs. The presented research reviews fundamental numerical and experimental results for the Mobile Bridge 4.0. Experimental testing included strain and acceleration measurements in free and forced loading conditions. From these results, it was possible to estimate basic mechanics characteristics, that is statics and dynamic property, of the bridge. The conducted research allows for a better and safer design of the structure of the Mobile Bridge. Keywords: Deployable Bridge; Scissors-type bridge; Emergency Bridge; Dynamic property; Natural frequency; Acceleration measurement | |
172. | Chikahiro Y., Ario I., Adachi K., Shimizu S., Pawłowski P.^{♦}, Graczykowski C.^{♦}, Holnicki-Szulc J.^{♦}, FUNDAMENTAL STUDY ON DYNAMIC PROPERTY OF
DEPLOYABLE EMERGENCY BRIDGE USING SCISSORS MECHANISM, Footbridge Berlin 2017, 6th International Footbridge Conference, 2017-09-06/09-08, TU Berlin (DE), pp.1-6, 2017Chikahiro Y., Ario I., Adachi K., Shimizu S., Pawłowski P.^{♦}, Graczykowski C.^{♦}, Holnicki-Szulc J.^{♦}, FUNDAMENTAL STUDY ON DYNAMIC PROPERTY OF
DEPLOYABLE EMERGENCY BRIDGE USING SCISSORS MECHANISM, Footbridge Berlin 2017, 6th International Footbridge Conference, 2017-09-06/09-08, TU Berlin (DE), pp.1-6, 2017Abstract: The paper presents a new type of emergency bridge, which can be quickly constructed in case of damages
after a natural disaster. The concept of the bridge is based on the application of scissor-type mechanism,
which provides its rapid deployment. In case of deployable structures apart from static analysis of different
configurations of expansion, it is very important to investigate the dynamic behavior of the system. High compliance and flexibility of the scissors-type bridge may influence user's comfort and safety in case of heavy dynamic loads such as human induced impacts, wind gusts or earthquakes. Up to now, the authors constructed several types of the experimental MBs. The presented research reviews fundamental numerical and experimental results for the Mobile Bridge 4.0. Experimental testing included strain and acceleration measurements in free and forced loading conditions. From these results, it was possible to estimate basic mechanics characteristics, that is statics and dynamic property, of the bridge. The conducted research allows for a better and safer design of the structure of the Mobile Bridge. Keywords: Deployable Bridge; Scissors-type bridge; Emergency Bridge; Dynamic property; Natural frequency; Acceleration measurement | |
173. | Orłowska A., Graczykowski C., Gałęzia A., Manufacturing and properties of pre-stressed GFRP composites, MECHCOMP3, 3rd International Conference on Mechanics of Composites, 2017-07-04/07-07, School of Engineering and Architecture, University of Bologna, Italy (IT), pp.48-48, 2017Orłowska A., Graczykowski C., Gałęzia A., Manufacturing and properties of pre-stressed GFRP composites, MECHCOMP3, 3rd International Conference on Mechanics of Composites, 2017-07-04/07-07, School of Engineering and Architecture, University of Bologna, Italy (IT), pp.48-48, 2017Abstract: The concept of increasing strength capacity of structural elements by introducing preliminary stresses, counteracting the exploitation stresses, is known for years. Large number of applications of pre-stressed materials in civil engineering proves that proper compression of material can effectively increase the strength of structural elements. Because of the rapid development of composite materials, and growing demand for light materials with particularly high stiffness and strength properties, the pre-stressed FRP composites application in industry seems to be a question of time. This assumption is confirmed by increasing number of publications concerning the problem of mechanical characteristics for such materials.
This paper presents the results of preliminary research on the pre-stressing of the FRP composite structures, while the term pre-stress indicates initial tensile stress applied to the fibres embedded in selected layers of the composite material. Manufacturing process and shape forming possibilities as well as short-term static and dynamic behaviour of the pre-stressed composites are discussed. Presented results are achieved by the use of the experimental methods (three-point bending tests and Experimental Modal Analysis) and experimentally verified Finite Element Method model of pre-stressed structure.
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174. | Chikahiro Y., Ario I., Pawlowski P., Graczykowski C., Nakazawa M., Holnicki-Szulc J., Ono S., Dynamics of the scissors-type Mobile Bridge, EURODYN 2017, X International Conference on Structural Dynamics, 2017-09-10/09-13, Rome (IT), pp.199-199, 2017 | |
175. | Graczykowski C., Pawłowski P., Mathematical Modelling of Adaptive Skeletal Structures for Impact Absorption and Vibration Damping, EURODYN 2017, X International Conference on Structural Dynamics, 2017-09-10/09-13, Rome (IT), pp.123-123, 2017 | |
176. | Popławski B., Mikułowski G., Mróz A.^{♦}, Sekuła K., Jankowski Ł., A decentralized strategy of structural reconfiguration in mitigation of vibrations, EURODYN 2017, X International Conference on Structural Dynamics, 2017-09-10/09-13, Rome (IT), pp.114-114, 2017 | |
177. | Zieliński T.G., Jankowski Ł., Opiela K., Deckers E., Modelling of poroelastic media with localised mass inclusions, SAPEM'2017, SAPEM'2017 - 5th Symposium on the Acoustics of Poro-Elastic Materials, 2017-12-06/12-08, Le Mans (FR), pp.1-2, 2017 | |
178. | Barglik J., Ducki K., Kukla D.^{♦}, Mizera J., Mrówka-Nowotnik G., Sieniawski J., Smalcerz A., Comparison of Single and Consecutive Dual Frequency Induction Surface Hardening of Gear Wheels, VIII International Scientific Colloquium Modelling for Materials Processing, 2017-09-21/09-22, Riga (LV), DOI: 10.22364/mmp2017.27, pp.185-190, 2017Barglik J., Ducki K., Kukla D.^{♦}, Mizera J., Mrówka-Nowotnik G., Sieniawski J., Smalcerz A., Comparison of Single and Consecutive Dual Frequency Induction Surface Hardening of Gear Wheels, VIII International Scientific Colloquium Modelling for Materials Processing, 2017-09-21/09-22, Riga (LV), DOI: 10.22364/mmp2017.27, pp.185-190, 2017Abstract: Mathematical modeling of single and consecutive dual - frequency induction surface hardening systems are presented and compared. The both models are solved by the 3D FEMbased professional software supported by a number of own numerical procedures. The methodology is illustrated with some examples of surface induction hardening of a gear wheel made of steel 41Cr4. The computations are in a good accordance with experiments provided on the laboratory stand | |
179. | Słowicka A.M., Stone H.A., Ekiel-Jeżewska M.L., Periodic motions of flexible fibers in shear flow, Bulletin of the American Physical Society, ISSN: 0003-0503, Vol.62, No.14, pp.221-221, 2017 | |
180. | Graczykowski C., Orłowska A., Modelling and design procedure of prestressed composite materials, MECHCOMP3, 3rd International Conference on Mechanics of Composites, 2017-07-04/07-07, School of Engineering and Architecture, University of Bologna, Italy (IT), pp.154-154, 2017Graczykowski C., Orłowska A., Modelling and design procedure of prestressed composite materials, MECHCOMP3, 3rd International Conference on Mechanics of Composites, 2017-07-04/07-07, School of Engineering and Architecture, University of Bologna, Italy (IT), pp.154-154, 2017Abstract: The paper introduces the concept of eccentrical prestressing of fiber reinforced polymer materials in order to improve their mechanical properties and global mechanical behaviour. Prestressing is here understood as application of the initial tensile stress to the fibres embedded in selected external layers of the composite material. The objective of prestressing is to increase stiffness of the composite and to obtain desired response to applied external loading. The main objective of this research work is to develop a comprehensive approach to analysis of prestressed composites, which includes analytical and numerical modelling of the static behaviour, optimal composite design, as well as, simulation of dynamic response. Initially, we derive simple and effective analytical model of prestressed composite based on models of individual prestressed plies and their homogenization. The analytical model is used to reveal beneficial influence of prestress on strain and stress distribution in particular plies and resulting increase of the composite stiffness. Further, three options for the FEM-based numerical modelling of prestressed composites are proposed and thoroughly compared with each other. Developed analytical and numerical models are used to propose methods of prestressed composite design in which optimization of prestressing forces is used to minimize required composite thickness or fiber volume fraction. Eventually, FEM simulations are applied to assess the influence of prestress force magnitude on natural frequencies and modal shapes of eccentrically prestressed composite beams of various fibre volume fraction. The final part of the paper summarizes the potential advantages of the prestressed composites and unveils their superiority in comparison to the standard ones. Potential applications of prestressed composite materials in civil engineering and aerospace industry are briefly discussed. In addition, challenges related to design and manufacturing of structures made of prestressed composite materials are presented.
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181. | Faraj R., Graczykowski C., Holnicki-Szulc J., Knap L., Seńko J., Adaptable pneumatic shock-absorber, SMART 2017, 8th Conference on Smart Structures and Materials, 2017-06-05/06-08, Madrid (ES), pp.1-8, 2017Faraj R., Graczykowski C., Holnicki-Szulc J., Knap L., Seńko J., Adaptable pneumatic shock-absorber, SMART 2017, 8th Conference on Smart Structures and Materials, 2017-06-05/06-08, Madrid (ES), pp.1-8, 2017Abstract: Pneumatic dampers are still an attractive subject of research in both modelling and experimental testing. Progress in the field of sensors and actuators allows to construct more and more efficient absorbers and dampers based on active or semi-active control algorithms. However, passive and semi-passive solutions are also developed because of their lower costs and simplicity. This paper presents adaptable pneumatic shock-absorber that allows to obtain optimal impact absorption and energy dissipation by a single reconfiguration performed at the beginning of the process. The absorber is composed of two cylinders including at least one narrow rectangular slot and adequate number of outflow vents precisely shaped for certain impact scenarios. During operation of the device the air is released through overlapping slots and selected vents, which provides constant value of the generated force. As a result, the shock-absorber works as a passive device but provides minimal value of the reaction force in similar manner as semi-active system equipped with fully controllable mechanical valve. The paper presents the results of numerical simulations of adaptable shock-absorber operation and attempts of demonstrator construction aimed at conducting experimental verification of the concept. Keywords: Adaptable, Semi-passive, Impact Absorption, Pneumatic Shock-absorber | |
182. | Pieczyska E.A., Staszczak M., Golasiński K., Maj M., Tobushi H., Kuramoto S., Furuta T., Investigation of Shape Memory Alloys, Polymers and Gum Metals for Biomedical Applications, Materials Science and Nanoscience 2-d Global Congress and Expo, 2017-09-25/09-27, Valencia (ES), pp.1-1, 2017 | |
183. | Pieczyska E.A., INVESTIGATION OF SHAPE MEMORY MATERIALS CONDUCTED IN IPPT PAN (POLAND) in COOPERATION WITH JAPAN (1990-2016), International Workshop on Advances in Shape Memory Materials, 2017-03-27/03-29, Aichi Institute of Technology, Nagoya (JP), pp.13-14, 2017 | |
184. | Kowalewski Z.L., Ustrzycka A., Szymczak T., Fatigue Damage Analysis of Power Engineering Materials Using ESPI Method, ACAM9, 9TH Australasian Congress on Applied Mechanics, 2017-11-27/11-29, UNSW Sydney (AU), pp.1-8, 2017Kowalewski Z.L., Ustrzycka A., Szymczak T., Fatigue Damage Analysis of Power Engineering Materials Using ESPI Method, ACAM9, 9TH Australasian Congress on Applied Mechanics, 2017-11-27/11-29, UNSW Sydney (AU), pp.1-8, 2017Abstract: In most cases, fatigue damage has a local character and it is based on damage development leading to generation of cracks appearing around structural defects or geometrical notches. An identification of these areas and their subsequent monitoring requires a full-field displacement measurements performed on the objects surfaces. This paper presents an attempt to use the Electronic Speckle Pattern Interferometry (ESPI) method for fatigue damage evaluation and its monitoring on specimens made of the P91 steel and aluminide coated nickel super-alloys. In this work, also a development of fatigue damage was investigated using destructive and non-destructive methods in materials commonly applied in power engineering or automotive industry. The fatigue tests for a range of different materials were interrupted for selected number of cycles in order to assess a damage degree. As destructive methods the standard tensile tests were carried out after prestraining due to fatigue. Subsequently, an evolution of the selected tensile parameters was taken into account for damage identification. The ultrasonic or magnetic techniques were used as the non-destructive methods for damage evaluation. In the final step of the experimental programme microscopic observations were performed. The results show that ultrasonic and magnetic parameters can be correlated with those coming from destructive tests. It is shown that good correlation of mechanical and selected non-destructive parameters identifying damage can be achieved for the materials tested Keywords: Fatigue, damage, optical methods, non-destructive techniques | |
185. | Bukowicki M., Ekiel-Jeżewska M.L., Symmetric pair of elongated particles settling at low Reynolds number regime, Bulletin of the American Physical Society, ISSN: 0003-0503, Vol.62, No.14, pp.250-250, 2017 | |
186. | Rojek J., Nosewicz S., Maździarz M., Kowalczyk P., Wawrzyk K., Modelling of sintering at atomistic, microscopic and macroscopic scales, Komplastech 2017, XXIV International Conference on Computer Methods in Materials Technology, 2017-01-15/01-18, Zakopane (PL), pp.126-128, 2017 | |
187. | Lumelskyj D.^{♦}, Rojek J.^{♦}, Numeryczne wyznaczenie początku lokalizacji odkształcenia w procesie tłoczenia blach na przykładzie próby tłoczności Nakazimy, FiMM 2017, X Jubileuszowa Konferencja, Fizyczne i Matematyczne Modelowanie Procesów Wytwarzania , 2017-05-21/05-23, Jabłonna (PL), pp.1-1, 2017 | |
188. | Rojek J., Nosewicz S., Chmielewski M., Coupling micro- and macroscopic levels in a sintering model, VII International Conference on Coupled Problems in Science and Engineering, 2017-06-12/06-14, Rhodes Island (GR), pp.1-1, 2017 | |
189. | Rojek J., Lumelskyj D., Nosewicz S., Romelczyk B., An elastoplastic contact model for spherical discrete elements, ICCCM 2017, International Conference on Computational Contact Mechanics, 2017-07-05/07-07, Lecce (IT), pp.1-1, 2017 | |
190. | Rojek J., Nosewicz S., Maździarz M., Kowalczyk P., Wawrzyk K., Multiscale modelling of powder sintering processes, COMPLAS 2017, XIV International Conference on Computational Plasticity. Fundamentals and Applications, 2017-09-05/09-07, Barcelona (ES), pp.1-1, 2017 | |
191. | Rojek J., Nosewicz S., Lumelskyj D., Romelczyk B., Bochenek K., Chmielewski M., Simulation of low-pressure powder compaction using an elastoplastic discrete element model, PARTICLES 2017, V International Conference on Particle-Based Methods. Fundamentals and Applications., 2017-09-26/09-28, Hannover (DE), pp.1-1, 2017 | |
192. | Gruziel M., Thyagarajan K., Dietler G., Szymczak P., Ekiel-Jeżewska M.L., Dynamics of knotted flexible loops settling under a constant force in a viscous fluid, Bulletin of the American Physical Society, ISSN: 0003-0503, Vol.62, No.14, pp.81-81, 2017 | |
193. | Trombley C., Ekiel-Jeżewska M.L., Stable Systems of Charged Sedimenting Particles, Bulletin of the American Physical Society, ISSN: 0003-0503, Vol.62, No.14, pp.575-575, 2017 | |
194. | Bławzdziewicz J., Adamczyk Z., Ekiel-Jeżewska M.L., Streaming current for particle-covered surfaces: simulations and experiments, Bulletin of the American Physical Society, ISSN: 0003-0503, Vol.62, No.14, pp.424-424, 2017 | |
195. | Pierini F., Nakielski P., Pawłowska S., Piechocka I., Zembrzycki K., Kowalewski T.A., Development and applications of atomic force microscopy combined with optical tweezers (AFM/OT), AFM BioMed, 8th AFM BioMed Conference, 2017-09-04/09-08, Kraków (PL), pp.103-103, 2017Pierini F., Nakielski P., Pawłowska S., Piechocka I., Zembrzycki K., Kowalewski T.A., Development and applications of atomic force microscopy combined with optical tweezers (AFM/OT), AFM BioMed, 8th AFM BioMed Conference, 2017-09-04/09-08, Kraków (PL), pp.103-103, 2017Abstract: Atomic force microscopy (AFM) is an evolution of scanning tunnelling microscopy that immediately gained popularity thanks to its ability to analyse nanomaterials. Initially, AFM was developed for nanomaterials imaging purposes, however the development of new features made it the most commonly used tool for studying the biophysical properties of biological samples. On the other hand, atomic force microscopy has limited use for examining sub-piconewton forces. Few techniques have been developed to measure forces below the AFM limit of detection. Among them, optical tweezers (OT) stand out for their high resolution, flexibility, and because they make it possible to accurately manipulate biological samples and carry out biophysics experiments without side effects thanks to their non-invasive properties.
The combination of AFM with other techniques in the last decades has significantly extended its capability. The improvement of the AFM force resolution by developing a hybrid double probe instrument based on the combination of AFM and OT has great potential in cell or molecular biology. [1]
We outline principles of atomic force microscopy combined with optical tweezers (AFM/OT) developed by our team underlying the techniques applied during the design, building and instrument use stages. We describe the experimental procedure for calibration of the system and we prove the achievement of a higher resolution (force: 10 fN – spatial: 0.1 nm – temporal: 10 ns) than the stand alone AFM.
We show the use of the hybrid equipment in a number of different biophysics experiments performed employing both AFM and OT probes. The presented studies include the demonstration of simultaneous high-precision nanomanipulation and imaging, the evaluation of single biomolecule mechanical properties and the single cell membrane activation and probing. Finally, we show the further potential applications of our AFM/OT.
Keywords: AFM, Optical Tweezers | |
196. | Ekiel-Jeżewska M., Jak żyli nauczyciele w II Rzeczypospolitej?, Mińskie Zeszyty Muzealne, ISSN: 2299-3827, Vol.5, pp.171-176, 2017 | |
197. | Dłużewski P., Tensor form of Vegard’s law for crystals of low symmetry
, ICMM5, 5th International Conference on Material Modeling, 2017-06-14/06-16, Rome (IT), pp.1-1, 2017 | |
198. | Kiełczyński P., Application of ultrasonic methods for the investigation of physicochemical parameters of edible oils, 25th Jubilee International Scientific Conference, Progress in Technology of Vegetable Fats, 2017-05-31/06-02, Rynia (PL), pp.37-38, 2017Kiełczyński P., Application of ultrasonic methods for the investigation of physicochemical parameters of edible oils, 25th Jubilee International Scientific Conference, Progress in Technology of Vegetable Fats, 2017-05-31/06-02, Rynia (PL), pp.37-38, 2017Abstract: The presentation includes an overview of the ultrasonic methods used to investigate the physicochemical properties of edible oils in the high pressure range.
Using ultrasonic waves we can determine (relatively easily) a number of physicochemical parameters of edible oils in the range of high pressures.
On the other hand, the determination of these high pressure parameters using classical measurement methods (e.g., calorimetry, IRF spectroscopy) is very difficult, practically impossible. The knowledge of these physicochemical parameters of oils is important due to the increasingly widespread use of high-pressure food preservation and processing methods.
The most important physicochemical parameters of oils include: 1) adiabatic and isothermal compressibility; 2) thermal expansion coefficient; 3) specific heat at constant pressure 4) surface tension; 5) viscosity and 6) thermal pressure coefficient. The knowledge of these physicochemical parameters of oils high pressures for various temperature values is essential in the design and optimization of high-pressure technological processes of food preservation and food processing.
Particularly difficult (using classical measurement methods) is to measure the viscosity of oils under high pressure. The application of the ultrasonic surface wave method of Love or Bleustein-Gulyaev type (developed at the Institute of Fundamental Technological Research of the Polish Academy of Sciences) solves this problem, allowing determination of oil viscosity for pressures above 200 MPa.
An interesting phenomenon that we can investigate by ultrasonic methods are the high-pressure phase transitions in edible oils. Using ultrasonic methods, high pressure phase transformations in many edible oils (e.g., in olive oil, in rapeseed oil, and in camelina sativa oil) and in their components, such as TAG (triacylglycerol) and DAG (diacylglycerol), were detected and investigated.
It is practically impossible to investigate these high pressure phase transformations in edible oils using classical measurement methods. Numerous documented advantages of ultrasonic methods in the high pressure range were the motivation to perform the presented study.
Keywords: Ultrasonic methods, Physicochemical properties of oils | |
199. | Kiełczyński P., Love Surface Wave Biosensors, 12th TOIN International Symposium on Biomedical Engineering, 2017-11-11/11-11, Yokohama (JP), pp.21-23, 2017Kiełczyński P., Love Surface Wave Biosensors, 12th TOIN International Symposium on Biomedical Engineering, 2017-11-11/11-11, Yokohama (JP), pp.21-23, 2017Abstract: In this presentation I will address a fascinating example of a beneficiary interdisciplinary research. To be more specific, I will consider mutual interactions between the biosensor technology and seismology, two vital domains of research with huge practical importance in the life of modern Japanese society. I would like to convey a message that developments made in one scientific (engineering) domain can be very useful in another field of research, and vice-versa. Such mutual influence of different branches of science (engineering) can significantly accelerate progress in the considered domains of R&D activities. In this presentation I will focus on one type of acoustic (ultrasonic) sensors, i.e., those employing Love surface waves, first discovered in seismology in 1911 by the British mathematician A. E. H. Love. Since the ultrasonic sensors employing Love surface waves emerged some 80 years later, in the paper published by the author in 1989, it is not surprising that many theoretical and experimental techniques were first developed in seismology and then transferred to the sensor technology. The mathematical formalism describing seismic Love waves and those used in biosensor technology is in principle the same, i.e., it uses the theory of the Sturm-Liouville problem, deeply rooted in functional analysis, in particular the spectral theory of compact operators and Hilbert space. Seismic Love waves can travel thousands of kilometers around the surface of the Earth and have the frequency range ~0.01-10 Hz. On the other hand, those used in biosensor technology are of much higher frequencies (~50-500 MHz) but travel accordingly shorter distances (~5-50 mm) in man-made waveguides. It should be noticed that seismic Love surface waves are main contributors to devastating consequences in aftermath of earthquakes. On the other hand, Love wave biosensors offer a unique possibility for measurements of a large number of very important properties of biological materials. Keywords: Love waves, Sensors, Biosensors, Chemosensors, Viscosity sensors | |
200. | Dłużewski P., Wierzbicki R., Tauzowski P., Kret S., Kaleta A., Sadowski J., 3D strain field and STEM contrast modeling of core shell nanowirers containing magnetic nanoprecipitations , EUROMAT 2017 , European Congress and Exhibition on Advanced Materials and Processes, 2017-09-17/09-22, Thessaloniki (GR), pp.1-1, 2017 | |
201. | Kiełczyński P., Szalewski M., Balcerzak A., Wieja K., The influence of rheological parameters of viscoelastic
liquids on the propagation characteristics of ultrasonic Love
waves, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), pp.415-415, 2017Kiełczyński P., Szalewski M., Balcerzak A., Wieja K., The influence of rheological parameters of viscoelastic
liquids on the propagation characteristics of ultrasonic Love
waves, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), pp.415-415, 2017Abstract: Progress in materials engineering has led to development of new materials with improved functional characteristics. One of the new types of
materials introduced into industrial practice are plastics and polymers. These materials exhibit rheological (viscoelastic) properties, which combine
simultaneously the properties of liquids and solids. Due to their attractive features, such as low specific weight, high resistance to chemical agents,
cost effectiveness etc. these materials are widely used in chemical, automotive, aviation and space industry. Thus, it is very important to develop
new, robust and accurate methods to measure the rheological parameters (viscosity η, elasticity μ and density ρ) of plastics and polymers. The
conventional mechanical methods used so far to this end are outdated, time consuming, and cumbersome. To overcome this problems, the authors
propose the use of ultrasonic methods that employ surface Love waves, what is a novelty. Keywords: Love waves, Rheological parameters, Rheological models, Polymers | |
202. | Dyniewicz B., Bajer C.I., Lightweight bridges for fast moving loads, XXV French-Polish Seminar on Mechanics, 2017-05-15/05-16, Bourges (FR), pp.14, 2017 | |
203. | Bajkowski J.M., Dyniewicz B., Bajer C.I., Experimental beam structure with magnetically controlled damping blocks, XXV French-Polish Seminar on Mechanics, 2017-05-15/05-16, Bourges (FR), pp.6, 2017 | |
204. | Kielczynski P., Ptasznik S., Szalewski M., Balcerzak A., Wieja K., Rostocki A.J., Investigation of regular and anomalous behavior of liquid media under high pressure using ultrasonic methods
, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), pp.417-417, 2017Kielczynski P., Ptasznik S., Szalewski M., Balcerzak A., Wieja K., Rostocki A.J., Investigation of regular and anomalous behavior of liquid media under high pressure using ultrasonic methods
, 2017 IEEE, 2017 IEEE International Ultrasonics Symposium, 2017-09-06/09-09, Washington, DC (US), pp.417-417, 2017Abstract: Background, Motivation and Objective
In many industrial technological processes, liquids are subjected to high pressures, e.g., in the high pressure food preservation. Similarly, in modern fuel
injection systems for diesel engines, biofuel is subjected to a pressure up to 300 MPa. In such conditions, in liquids, phase transitions can occur that
substantially increase the density and liquid viscosity. This can be very detrimental for the engine or the technological equipment. Thus, it is important to
determine at what pressures and temperatures phase transitions occur. Conventional mechanical methods for measuring physicochemical properties of
liquids at these extreme conditions do not operate. By contrast, ultrasonic techniques are very suitable for measurements of physicochemical properties of
liquids at high pressure, since they are non-destructive and can be fully automated. The aim of this work is to study the high-pressure physicochemical
properties of liquids (exemplified by a camelina sativa - false flax oil) using novel ultrasonic methods. Keywords: High pressure, Biofuels, Viscosity, Phase transitions | |
205. | Kucharski S., Stupkiewicz S., Petryk H., Size effect in indentation tests: experimental and numerical investigations, EUROMAT 2017 , European Congress and Exhibition on Advanced Materials and Processes, 2017-09-17/09-22, Thessaloniki (GR), No.D4-H-TUE-PM1, pp.1-2, 2017 | |
206. | Kucharski S., Stupkiewicz S., Petryk H., Size effect observed in spherical indentation test of single crystal copper, Nanomechanical Testing in Materials Research and Development VI, 2017-10-01/10-06, Dubrovnik (HR), pp.1-1, 2017Kucharski S., Stupkiewicz S., Petryk H., Size effect observed in spherical indentation test of single crystal copper, Nanomechanical Testing in Materials Research and Development VI, 2017-10-01/10-06, Dubrovnik (HR), pp.1-1, 2017Keywords: indentation size effect, single crystal, spherical indentation, numerical simulation | |
207. | Trawinski Z., Hilgertner L., Examinations of the Degree of Atherosclerosis by Means of Input Vascular Impedance., OSA 2017, LXIV Open Seminar on Acoustics, 2017-09-11/09-15, Piekary Śląskie (PL), Vol.42, No.3, pp.555-555, 2017Trawinski Z., Hilgertner L., Examinations of the Degree of Atherosclerosis by Means of Input Vascular Impedance., OSA 2017, LXIV Open Seminar on Acoustics, 2017-09-11/09-15, Piekary Śląskie (PL), Vol.42, No.3, pp.555-555, 2017Abstract: The input vascular impedance was determined using ultrasound continuous wave Doppler flow meter and a system for tracking arterial wall movements. The study was conducted in a control group (30 volunteers) and in four groups (10 patients in each group). Patients were grouped according to the criteria ofatherosclerotic stage, which was the degree of arterial stenosis: 20–49%, 50–69%, 70–89%, and 90–99% and occlusion, based on ultrasound or duplex tests. The results of Student’s t-test showed the statistically significance of the sparation of longitudinal resistance Ro results from the control group and sequentially four groups with a defined degree of atherosclerotic carotid artery at a 95% confidence level with significance level from p < 5.2E−3 for 20–49% - for the receiver operating curve (ROC), the area under curve (AUC) = 0.76; p < 8.6E−9 for the stenosis 50-69% - for the ROC curve AUC = 0.913, p < 6.3E−9 for the stenosis 70–89% for ROC curve AUC = 0.94, to p < 8.1E−10 for stenosis above 90% and occlusion, for ROC curve AUC = 0.97. After combining data for patients with internal carotid artery stenosis from 50–89% the results of Student’s t-test showed the statistical significance of the separation of the longitudinal resistance results Ro derived from the control group and the combined group with a confidence level of 95% at significance level p < 2.8E−10, for ROC curve AUC = 0.942. Keywords: Vascular input impedance, common carotid artery, ultrasound. | |
208. | Sajkiewicz P., Dulnik J., Kołbuk-Konieczny D., Denis P., The effect of solvent-polymer interactions on cellular response of electrospun PCL/gelatin and PCL/collagen fibers, ESB 2017, 28th European Conference on Biomaterials, 2017-09-04/09-08, Ateny (GR), pp.1, 2017 | |
209. | Nowicki A., Trawiński Z., Gambin B., Secomski W., Szubielski M., Parol M., Olszewski R., Measurements of Flow Mediated Dilation and Shear Rate in the Radial Artery Using 20 MHz Ultrasonic System in Patients with Coronary Artery Disease., XXI Międzynarodowy Kongres Polskiego Towarzystwa Kardiologicznego. , 2017-09-21/09-23, Katowice. (PL), pp.1-1, 2017Nowicki A., Trawiński Z., Gambin B., Secomski W., Szubielski M., Parol M., Olszewski R., Measurements of Flow Mediated Dilation and Shear Rate in the Radial Artery Using 20 MHz Ultrasonic System in Patients with Coronary Artery Disease., XXI Międzynarodowy Kongres Polskiego Towarzystwa Kardiologicznego. , 2017-09-21/09-23, Katowice. (PL), pp.1-1, 2017Abstract: A novel high-frequency scanning system, with a 20-MHz linear array transducer combined with 20-MHz pulsed Doppler, was introduced to evaluate the degree of radial artery flow-mediated dilation (FMD) and shear rate (SR)-normalized FMD (FMD/SR) after 5 min of reactive hyperaemia. In group I, comprising 27 healthy volunteers, FMD was 15 ± 4.8%, and in group II, comprising 17 patients with coronary artery disease, FMD was significantly smaller, being equal to 4.6 ± 4%. FMD/SR was equal to 5.365 ± 4.835·10-4 in group I and 1.3 ± 0.89·10-4 in group II. Statistically significant differences between the two groups were confirmed by Wilcoxon-Mann-Whitney test for FMD and FMD/SR (p-values < 0.01). AUCs of ROC curves for FMD and FMD/SR were greater than 0.9. The results confirm the usefulness of the proposed measurements of radial artery FMD and SR in differentiation of normal subjects from those with atherosclerotic lesions. Keywords: flow mediated vasodilation, radial artery, shear rate, reactive hyporaemia, endothelium, pulsed Doppler, ultrasonography. | |
210. | Walenta Z.A., Słowicka A.M., Structure of shock waves in noble gases under high density conditions, ISSW31, The 31st International Symposium on Shock Waves, 2017-07-09/07-14, Nagoya (JP), No.SBM000360, pp.1-6, 2017Walenta Z.A., Słowicka A.M., Structure of shock waves in noble gases under high density conditions, ISSW31, The 31st International Symposium on Shock Waves, 2017-07-09/07-14, Nagoya (JP), No.SBM000360, pp.1-6, 2017Abstract: In the present paper we show the dependence of the shock structure in a dense, noble gas on each of the three non-dimensional parameters: non-dimensional initial density, non-dimensional initial temperature and non-dimensional shock velocity. It will also be demonstrated, that the length scale, most suitable for measuring the thickness of the shock wave in a dense gas, is the sum of the mean free path (calculated the same way as for a dilute gas) and the diameter of a single gas molecule. | |
211. | Marszałek A., Burczyński T., Fuzzy Portfolio Diversification with Ordered Fuzzy Numbers, 16th International Conference, ICAISC 2017, 2017-06-11/06-15, Zakopane (PL), pp.279-291, 2017Marszałek A., Burczyński T., Fuzzy Portfolio Diversification with Ordered Fuzzy Numbers, 16th International Conference, ICAISC 2017, 2017-06-11/06-15, Zakopane (PL), pp.279-291, 2017Abstract: In this paper, we consider a multi-objective portfolio diversification problem under real constraints in fuzzy environment, where the objective is to minimize the variance of portfolio and maximize expected return rate of portfolio. The return rates of assets are modeled using concept of Ordered Fuzzy Candlesticks, which are Ordered Fuzzy Numbers. The use of them allows modeling uncertainty associated with financial data based on high-frequency data. Thanks to well-defined arithmetic of Ordered Fuzzy Numbers, the estimators of fuzzy-valued expected value and covariance can be computed in the same way as for real random variables. In an empirical study, 20 assets included in the Warsaw Stock Exchange Top 20 Index are used to compare considered fuzzy model with crisp mean-variance model Keywords: Ordered fuzzy number, Kosinski’s fuzzy number, Ordered fuzzy candlestick, Fuzzy portfolio diversification, Fuzzy returns, Multi-objective optimization, Financial high-frequency data | |
212. | Burczyński T., Mrozek A., Kuś W., Design of New Flat Nanomaterials Based on Carbon, NanoWorld Conference, 2017-04-03/04-05, Boston (US), pp.1, 2017 | |
213. | Długosz A., Pokorska I., Glinicki M.A., Jaskulski R.^{♦}, Evolutionary computation in identification of thermophysical properties of hardening concrete, CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), pp.1-2, 2017Długosz A., Pokorska I., Glinicki M.A., Jaskulski R.^{♦}, Evolutionary computation in identification of thermophysical properties of hardening concrete, CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), pp.1-2, 2017Abstract: The evolutionary computation procedures in identification of thermophysical properties of hardening concrete in massive structures are presented. Heat of cement hydration, thermal conductivity and specific heat are determined for purpose of modelling temperature evolution in massive concrete elements. The knowledge of temperature fields is very important due to a link with undesired thermal stresses, which can cause a weakening of the structure because of thermal cracking. The proposed method is based on point temperature measurements in a cylindrical mould and the numerical solution of the inverse heat transfer problem by means of finite element method and evolutionary computation Keywords: heat of cement hydration, inverse heat transfer problem, early age concrete, evolutionary algorithm, finite element method, thermophysical properties of concrete | |
214. | Mrozek A., Kuś W., Burczyński T., Molybdenum base 2D materials modelling, CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), pp.1-2, 2017Mrozek A., Kuś W., Burczyński T., Molybdenum base 2D materials modelling, CMM-2017, 22nd International Conference on Computer Methods in Mechanics, 2017-09-13/09-16, Lublin (PL), pp.1-2, 2017Abstract: The flat, two dimensional materials play important role in the research and industrial applications in the last 15 years. The new materials with flat atomic structures are discovered every month. The focus of the paper is on the modelling of the flat sheet of molybdenum based material. The numerical simulations and mechanical material properties are described and discussed. Keywords: molybdenum, two dimensional materials, molecular modelling, MoS2 | |
215. | Mrozek A., Kuś W., Burczyński T., INVERSE PROBLEM FOR DESIGN OF NEW CARBON-BASED 2D MATERIALS WITH PREDIFINED MECHANICAL PROPERTIES, ECCOMAS International Conference IPM 2017 on Inverse Problems in Mechanics of Structure and Materials, 2017-05-31/06-02, Rzeszów-Krasiczyn (PL), pp.1-2, 2017 | |
216. | Brandt A.M., Jeszcze o habilitacji, PAUZA AKADEMICKA, ISSN: 1689-488X, Vol.X, No.402, pp.1-1, 2017 | |
217. | Glinicki M.A., Exposed Aggregate Concrete for Highway Pavements - experimental Study on the Durability Performance, ISCC 2017, The 9th International Symposium on Cement and Concrete, 2017-10-31/11-03, Wuhan (CN), pp.89-89, 2017 | |
218. | Jóźwiak-Niedźwiedzka D., Gibas K., Glinicki M.A., Petrograficzna identyfikacja kruszyw podatnych na wystąpienie reakcji alkalicznej w betonie, VIII Konferencja Naukowa ENERGIA I ŚRODOWISKO, 2017-09-25/09-27, Szczyrk (PL), pp.50-50, 2017Jóźwiak-Niedźwiedzka D., Gibas K., Glinicki M.A., Petrograficzna identyfikacja kruszyw podatnych na wystąpienie reakcji alkalicznej w betonie, VIII Konferencja Naukowa ENERGIA I ŚRODOWISKO, 2017-09-25/09-27, Szczyrk (PL), pp.50-50, 2017Keywords: kruszywa łamane, reakcja AAR, analiza petrograficzna | |
219. | Piechocka I.K.^{♦}, Jansen K.A., Broedersz C.P., Kurniawan N.A., MacKintosh F.C., Koenderink G.H., Multi-scale strain-stiffening of semiflexible bundle networks, SOFT MATTER, ISSN: 1744-683X, DOI: 10.1039/c5sm01992c, Vol.12, No.7, pp.2145-2156, 2016Piechocka I.K.^{♦}, Jansen K.A., Broedersz C.P., Kurniawan N.A., MacKintosh F.C., Koenderink G.H., Multi-scale strain-stiffening of semiflexible bundle networks, SOFT MATTER, ISSN: 1744-683X, DOI: 10.1039/c5sm01992c, Vol.12, No.7, pp.2145-2156, 2016Abstract: Bundles of polymer filaments are responsible for the rich and unique mechanical behaviors of many biomaterials, including cells and extracellular matrices. In fibrin biopolymers, whose nonlinear elastic properties are crucial for normal blood clotting, protofibrils self-assemble and bundle to form networks of semiflexible fibers. Here we show that the extraordinary strain-stiffening response of fibrin networks is a direct reflection of the hierarchical architecture of the fibrin fibers. We measure the rheology of networks of unbundled protofibrils and find excellent agreement with an affine model of extensible wormlike polymers. By direct comparison with these data, we show that physiological fibrin networks composed of thick fibers can be modeled as networks of tight protofibril bundles. We demonstrate that the tightness of coupling between protofibrils in the fibers can be tuned by the degree of enzymatic intermolecular crosslinking by the coagulation factor XIII. Furthermore, at high stress, the protofibrils contribute independently to the network elasticity, which may reflect a decoupling of the tight bundle structure. The hierarchical architecture of fibrin fibers can thus account for the nonlinearity and enormous elastic resilience characteristic of blood clots. | | (40p.) |
220. | Kowalewski P.K., Olszewski R.^{♦}, Kwiatkowski A., Gałązka-Świderek N., Cichoń K., Paśnik K., Life with a Gastric Band. Long-Term Outcomes of Laparoscopic Adjustable Gastric Banding—a Retrospective Study, Obesity Surgery, ISSN: 0960-8923, DOI: 10.1007/s11695-016-2435-2, Vol.27, pp.1250-1253, 2016Kowalewski P.K., Olszewski R.^{♦}, Kwiatkowski A., Gałązka-Świderek N., Cichoń K., Paśnik K., Life with a Gastric Band. Long-Term Outcomes of Laparoscopic Adjustable Gastric Banding—a Retrospective Study, Obesity Surgery, ISSN: 0960-8923, DOI: 10.1007/s11695-016-2435-2, Vol.27, pp.1250-1253, 2016Abstract: Background: Laparoscopic adjustable gastric banding (LAGB) is the third most popular bariatric procedure worldwide. Various authors present ambivalent long-term follow up results. Methods: We revised records of the patients who underwent LAGB between 2003 and 2006 along with history of additional check-ins. Patients with outdated details were tracked with the national health insurance database and social media (Facebook). An online survey was sent. The patients who did not have their band removed were included in this study. We calculated the percent total weight loss (%TWL) and percent excess weight loss (%EWL), along with changes in body mass index (ΔBMI). Satisfactory weight loss was set at >50% EWL (for BMI = 25 kg/m(2)). Since eight patients gained weight, we decided to include negative values of %TWL, %EWL, and ΔBMI. Results: One hundred seven patients underwent LAGB from 2003 to 2006. The mean follow-up time was 11.2 (±1.2) years. Eleven percent of patients were lost to follow up (n = 12). There was one perioperative death. Fifty-four of the patients (n = 57) had their band removed. Thirty-seven patients still have the band (39%) and were included in the study. The mean %EWL was 27% (-56-112%) and %TWL was 11% (-19-53%). Twelve patients achieved %EWL > 50% (32%). Thiry-two patients still suffer from obesity, with BMI over 30 kg/m(2). Eight patients (22%) gained additional weight. Patients with %EWL > 50% suffered less from gastroesophageal reflux disease symptoms than those with EWL < 50% (p < 0.05). Conclusions: Out of 107 cases, only 11.2% of patients with gastric band (n = 12) achieved satisfactory %EWL. Twenty-two percent of patients regained their weight or even exceeded it. Overall results suggest that LAGB is not an effective bariatric procedure in long term observation.
Life with a Gastric Band. Long-Term Outcomes of Laparoscopic Adjustable Gastric Banding—a Retrospective Study (PDF Download Available). Available from: https://www.researchgate.net/publication/309486095_Life_with_a_Gastric_Band_Long-Term_Outcomes_of_Laparoscopic_Adjustable_Gastric_Banding-a_Retrospective_Study [accessed Dec 05 2017]. Keywords: Laparoscopy, Bariatric surgery, LAGB, Gastric band, Long term follow-up | | (40p.) |
221. | Balta H., Będkowski J.^{♦}, Govindaraj S., Majek K., Musialik P., Serrano D., Alexis K., Siegwart R., De Cubber G., Integrated Data Management for a Fleet of Search-and-rescue Robots, Journal of Field Robotics, ISSN: 1556-4959, DOI: 10.1002/rob.21651, Vol.34, No.3, pp.539-582, 2016Balta H., Będkowski J.^{♦}, Govindaraj S., Majek K., Musialik P., Serrano D., Alexis K., Siegwart R., De Cubber G., Integrated Data Management for a Fleet of Search-and-rescue Robots, Journal of Field Robotics, ISSN: 1556-4959, DOI: 10.1002/rob.21651, Vol.34, No.3, pp.539-582, 2016Abstract: Search-and-rescue operations have recently been confronted with the introduction of robotic tools that assist the human search-and-rescue workers in their dangerous but life-saving job of searching for human survivors after major catastrophes. However, the world of search and rescue is highly reliant on strict procedures for the transfer of messages, alarms, data, and command and control over the deployed assets. The introduction of robotic tools into this world causes an important structural change in this procedural toolchain. Moreover, the introduction of search-and-rescue robots acting as data gatherers could potentially lead to an information overload toward the human search-and-rescue workers, if the data acquired by these robotic tools are not managed in an intelligent way. With that in mind, we present in this paper an integrated data combination and data management architecture that is able to accommodate real-time data gathered by a fleet of robotic vehicles on a crisis site, and we present and publish these data in a way that is easy to understand by end-users. In the scope of this paper, a fleet of unmanned ground and aerial search-and-rescue vehicles is considered, developed within the scope of the European ICARUS project. As a first step toward the integrated data-management methodology, the different robotic systems require an interoperable framework in order to pass data from one to another and toward the unified command and control station. As a second step, a data fusion methodology will be presented, combining the data acquired by the different heterogenic robotic systems. The computation needed for this process is done in a novel mobile data center and then (as a third step) published in a software as a service (SaaS) model. The SaaS model helps in providing access to robotic data over ubiquitous Ethernet connections. As a final step, we show how the presented data-management architecture allows for reusing recorded exercises with real robots and rescue teams for training purposes and teaching search-and-rescue personnel how to handle the different robotic tools. The system was validated in two experiments. First, in the controlled environment of a military testing base, a fleet of unmanned ground and aerial vehicles was deployed in an earthquake-response scenario. The data gathered by the different interoperable robotic systems were combined by a novel mobile data center and presented to the end-user public. Second, an unmanned aerial system was deployed on an actual mission with an international relief team to help with the relief operations after major flooding in Bosnia in the spring of 2014. Due to the nature of the event (floods), no ground vehicles were deployed here, but all data acquired by the aerial system (mainly three-dimensional maps) were stored in the ICARUS data center, where they were securely published for authorized personnel all over the world. This mission (which is, to our knowledge, the first recorded deployment of an unmanned aerial system by an official governmental international search-and-rescue team in another country) proved also the concept of the procedural integration of the ICARUS data management system into the existing procedural toolchain of the search and rescue workers, and this in an international context (deployment from Belgium to Bosnia). The feedback received from the search-and-rescue personnel on both validation exercises was highly positive, proving that the ICARUS data management system can efficiently increase the situational awareness of the search-and-rescue personnel. | | (35p.) |
222. | Ortwein R., Ryś M.^{♦}, Skoczeń B., Damage evolution in a stainless steel bar undergoing phase transformation under torsion at cryogenic temperatures, INTERNATIONAL JOURNAL OF DAMAGE MECHANICS, ISSN: 1056-7895, DOI: 10.1177/1056789516656746, Vol.25, No.7, pp.967-1016, 2016Ortwein R., Ryś M.^{♦}, Skoczeń B., Damage evolution in a stainless steel bar undergoing phase transformation under torsion at cryogenic temperatures, INTERNATIONAL JOURNAL OF DAMAGE MECHANICS, ISSN: 1056-7895, DOI: 10.1177/1056789516656746, Vol.25, No.7, pp.967-1016, 2016Abstract: Phase transformation driven by plastic strains is commonly observed in austenitic stainless steels. In the present paper, this phenomenon is addressed in connection with damage evolution. A three-dimensional constitutive model has been derived, and scalar variables for damage and the volume fraction of the transformed phase were used. The model was solved using Abaqus UMAT user defined procedure, as well as by means of simplified one-dimensional approach for a twisted circular bar. Large experimental campaign of tests was performed, including martensite content measurements within the cross-section and on the surface of the bar during monotonic and cyclic loading. Based on the residual angle of twist, damage variable was calculated. The global response of torque versus the angle of twist was measured as well. Comparison between the experimental results and the results obtained from the simplified one-dimensional approach and from the full three-dimensional approach are presented. It turns out that one-dimensional formulation agrees quite well with full three-dimensional model. Thus, much simpler approach can effectively be used. Moreover, experimental results agree well in terms of the martensite content evolution and relation: torque versus the angle of twist. Damage evolution is correctly predicted in terms of the maximum values. Lastly, the evolution of damage during cyclic torsion is discussed, as the experimental results indicate rather surprising effect of unloading modulus recovery after each reversion of twist direction Keywords: Cryogenic temperatures, plastic strain-induced phase transformation, torsion, damage evolution, constitutive model, martensite, austenitic stainless steels | | (25p.) |
223. | Ryś M.^{♦}, Constitutive Modelling of Damage Evolution and Martensitic Transformation in 316L Stainless Steel, ACTA MECHANICA ET AUTOMATICA, ISSN: 1898-4088, DOI: 10.1515/ama-2016-0020, Vol.10, No.2, pp.125-132, 2016Ryś M.^{♦}, Constitutive Modelling of Damage Evolution and Martensitic Transformation in 316L Stainless Steel, ACTA MECHANICA ET AUTOMATICA, ISSN: 1898-4088, DOI: 10.1515/ama-2016-0020, Vol.10, No.2, pp.125-132, 2016Abstract: n this work, the constitutive model, derived with the use of thermodynamic of irreversible processes framework is presented. The model is derived under the assumption of small strains. Plastic strain induced martensitic phase transformation is considered in the austenitic matrix where the volume fraction of the martensite is reflected by a scalar parameter. The austenitic matrix is assumed as the elastic-plastic material and martensitic phase is assumed as randomly distributed and randomly oriented inclusions. Both phases are affected by damage evolution but there is no distinction in the model between damage in austenite and martensite Keywords: Constitutive Modelling, Dissipative Materials, Phase Transformation, Damage Evolution | | (14p.) |
224. | Jeznach O., Gajc M., Kłos A., Orliński K., Pawlak D.A., Krok-Borkowicz M., Rumian Ł., Pietryga K., Reczyńska K., Pamuła E., The effect of titanium dioxide addition on physical and biological properties of Na2O-B2O3-P2O5 and CaO-Na2O-P2O5 glasses, ENGINEERING OF BIOMATERIALS / INŻYNIERIA BIOMATERIAŁÓW, ISSN: 1429-7248, Vol.19, No.134, pp.2-7, 2016Jeznach O., Gajc M., Kłos A., Orliński K., Pawlak D.A., Krok-Borkowicz M., Rumian Ł., Pietryga K., Reczyńska K., Pamuła E., The effect of titanium dioxide addition on physical and biological properties of Na2O-B2O3-P2O5 and CaO-Na2O-P2O5 glasses, ENGINEERING OF BIOMATERIALS / INŻYNIERIA BIOMATERIAŁÓW, ISSN: 1429-7248, Vol.19, No.134, pp.2-7, 2016Abstract: Two types of phosphate glasses 50Na2O-20B2O3-30P2O5 (NBP) and 30CaO-20Na2O-50P2O5 (CNP) with different content of TiO2 (0, 3 and 5 mol%) have been prepared by melt-quenching process. TiO2 was added to increase glass network stability. Physical properties of glasses were investigated by density measurements, differential scanning calorimetry and degradation in phosphate buffered saline (PBS). Biological performance of glasses in a direct contact with osteoblast-like MG-63 cells was analysed with the use of resazurin test and live-dead staining. The results show that TiO2 addition increased density, glass transition temperature (Tg) and melting temperature (Tm) of both types of glasses. In the case of NBP glasses presence of TiO2 resulted in their fast degradation in PBS and acidification of cell culture medium. As a consequence such glasses did not support cell adhesion and growth, but they can be considered for e.g. drug delivery systems. On the other hand addition of TiO2 to CNP glasses resulted in enhanced cell adhesion and viability. Particularly positive results were found for CNP glass containing 5% TiO2, so it can be a good candidate as a scaffold material for bone tissue engineering. Keywords: phosphate glasses, bioactive glasses, titanium dioxide, tissue engineering | | (7p.) |
225. | Górecka K., Skłodowski M., Pawłowski P., Osowicki G., Belgijski pacjent. Polskie prace badawczo – konserwatorskie przy wielkoformatowym krzywoliniowym obrazie z XVIII w. z katedry Saint-Aubain w Namur, , Vol.21, No.80, pp.62-71, 2016Górecka K., Skłodowski M., Pawłowski P., Osowicki G., Belgijski pacjent. Polskie prace badawczo – konserwatorskie przy wielkoformatowym krzywoliniowym obrazie z XVIII w. z katedry Saint-Aubain w Namur, , Vol.21, No.80, pp.62-71, 2016Abstract: Paper discusses a concept and conservation methodology of the XVII. century curvilinear canvas painting "Adoration of the Magi" from the Saint-Aubain Cathedral church in Namur (Belgium). Atypical form of the painting bowed in the horizontal plane, adapted to a, wall and its enormous size (3.70 x 4.50 m) required using some innovative technologies and materials. Restoration work required access to both the face and the back of the picture. But how to overturn the painting? How to strengthen its support? How to tight. it? Such problems can be solved only by the interdisciplinary collaboration of a team of professionals. In this way decisions about the conservation were discussed in the group of experts from various disciplines. The article focuses o! n the problem of curvilinear canvas stretching, which is presented fro m different points of view. In the council participated restorers, scientist and engineers. Finally, we agreed that the basic premise of the conservation process was a detailed analysis of the canvas shape and its preservation on each step of the conservation works. The concept required construction of two curved platforms: concave and convex. The new system of the canvas overturning was also designed. An innovating method of strengthening of the canvas vertical direction during lining process by using Kevlar fibres was applied. The XVII. century stretcher frame was preserved as an example of historical construction. The new stretching system was built out of the original stretcher frame. The conservation works were finished in 2014, the painting was put in the frame and fixed on the wall. The optical analysis of its shape achieved one year after showed that its state is stable. | |
226. | Dziekoński C., Dera W., Frąś L., Jarząbek D.M., Precise force sensors for micro and nanotensile tests., SOLMECH 2016, 40th Solid Mechanics Conference, 2016-08-29/10-02, Warszawa (PL), pp.1, 2016 | |
227. | Dera W., Dziekoński C., Jarząbek D.M., The measurement of viscosity of thin polymer films, SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), pp.1, 2016 | |
228. | Nowicki A., Secomski W., Trawiński Z., Olszewski R., Estimation of Radial Artery Reactive Response using 20 MHz Ultrasound., 10th EAA International Symposium on Hydroacoustics, 2016-05-17/05-16, Jastrzębia Góra (PL), No.Archives of Acoustics, v. 41, No. 2., pp.356-357, 2016Nowicki A., Secomski W., Trawiński Z., Olszewski R., Estimation of Radial Artery Reactive Response using 20 MHz Ultrasound., 10th EAA International Symposium on Hydroacoustics, 2016-05-17/05-16, Jastrzębia Góra (PL), No.Archives of Acoustics, v. 41, No. 2., pp.356-357, 2016Abstract: Preceding atherosclerosis is endothelial dysfunction. There is therefore interest in the application of non-invasive clinical tools to assess endothelial function. There are commercially available ultrasound scanners to estimate Brachial Artery Reactive Response BARR by measuring the flow-mediated vasodilatation (FMD) of the brachial artery using 10–12 MHz linear array probes; however the precision in estimating of artery dilation does not exceeds 0.2 mm, far beyond the required one. We have introduced a high frequency scanning schemes; 25–35 MHz encoded (Golay) wobbling type imaging with- out Doppler (uScan developed in our lab, thick film wide bandwidth transducer, 50 microns axial resolution). In the second approach we have used 20 MHz linear scanning with 20 MHz pulsed Doppler attached to the linear array. Instead of brachial artery we have examined the radial artery where Radial Artery Reactive Response RARR was measured. The radial artery FMD were normalized using AUC of shear rate at the radial artery wall. The precision of the radial artery diameter measurements is over two times better using 20 MHz US instead of 7.5 MHz used for brachial artery FMD. The measured initial internal radial artery diameter was in range of 1.59–2.35 mm, the maximum diameter 2.01–2.60 mm was observed 40 to 55 seconds after releasing the cuff. In a limited number (14) of examined young, healthy patients the FMDSR were in the range from 7.8
to 9.9 in arbitrary units. In older patients with minor cardiac history the normalized FMDSR was clearly lower, 6.8 to 7.6. Keywords: thick film transducers, atherosclerosis, flow mediated vasodilation. | |
229. | Kucharski S., Starzyński G., Flattening of loaded rough surfaces: normal contact versus sliding contact, CMIS 2016, Contact Mechanics International Symposium, 2016-05-11/05-13, Warszawa (PL), pp.52-53, 2016 | |
230. | Jarząbek D.M., Chmielewski M., THE MEASUREMENT OF THE ADHESION FORCE BETWEEN CERAMIC PARTICLES AND METAL MATRIX IN CERAMIC REINFORCED-METAL MATRIX COMPOSITES, SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), No.P229, pp.1-2, 2016 | |
231. | Mróz Z., Kucharski S., Anisotropic friction and wear rules with account for anisotropy evolution, CMIS 2016, Contact Mechanics International Symposium, 2016-05-11/05-13, Warszawa (PL), No.P044, pp.64-65, 2016 | |
232. | Paczelt I., Mróz Z., Kucharski S., Baksa A., Analysis of wear processes for monotonic or periodic sliding and loading conditions, SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), pp.1-2, 2016 | |
233. | Egner H., Skoczeń B., Ryś M.^{♦}, Constitutive and numerical modeling of coupled dissipative phenomena in 316L stainless steel at cryogenic temperatures, International Journal of Plasticity, ISSN: 0749-6419, DOI: 10.1016/j.ijplas.2014.08.005, Vol.64, pp.113-133, 2015Egner H., Skoczeń B., Ryś M.^{♦}, Constitutive and numerical modeling of coupled dissipative phenomena in 316L stainless steel at cryogenic temperatures, International Journal of Plasticity, ISSN: 0749-6419, DOI: 10.1016/j.ijplas.2014.08.005, Vol.64, pp.113-133, 2015Abstract: A macroscopic material model for simulation of coupled dissipative phenomena taking place in FCC metals and alloys at low temperatures is developed. Three phenomena: plastic flow, plastic strain induced transformation from the parent phase ( to the secondary phase ( and evolution of micro-damage are studied using a thermodynamically consistent framework. The experimental results indicate a correlation between decreasing damage rate and increasing martensite content. For the micro-damage evolution in the parent austenitic phase a generalization of the classical isotropic ductile damage concept to anisotropic model has been adopted. The kinetics of damage evolution is based on the accumulated plastic strain as a driving force of ductile damage. On the other hand, the deterioration of the brittle secondary phase is described by the damage evolution equation expressed in the form of tensorial function, where the damage tensor depends directly on the stresses applied. This formulation accounts both for the isotropic damage, and for the oriented damage due to different effects of the stress tensor. Total amount of damage in the representative volume element is obtained via the linear rule of mixture. The results obtained in the course of numerical simulations fit well the experimental data Keywords: B. Constitutive behavior, A. Microcracking, A. Phase transformation, Cryogenic temperature | | (45p.) |
234. | Żywczyk Ł.^{♦}, Moskal A., Gradoń L., Numerical simulation of deep-bed water filtration, SEPARATION and PURIFICATION TECHNOLOGY, ISSN: 1383-5866, DOI: 10.1016/j.seppur.2015.10.003, Vol.156, pp.51-60, 2015Żywczyk Ł.^{♦}, Moskal A., Gradoń L., Numerical simulation of deep-bed water filtration, SEPARATION and PURIFICATION TECHNOLOGY, ISSN: 1383-5866, DOI: 10.1016/j.seppur.2015.10.003, Vol.156, pp.51-60, 2015Abstract: A two-dimensional simulator based on network model has been employed to design structure of filter composed of a few layers. The complex structure of the filter was represented by system of cylindrical channels connected via nodes, which represent basic quantities of the filter structure, like porosity or permeability. Performance of monolayer, multilayer and gradient filters was compared. Results show that depending on the number of layers, their porosities, the sequence of each layer aligned in the structure and channel diameter distribution significantly influence the amount of particles collected by the particular structure. Evolution of pressure drop, collection efficiency of particles and quality factors are the aspects, which should be tackled, to design an optimal filter structure Keywords: Deep bed-water filtration, Network model, DLVO, Brownian dynamics algorithm | | (40p.) |
235. | Żywczyk Ł.^{♦}, Moskal A., Modelling of deposition of flexible fractal-like aggregates on cylindrical fibre in continuum regime, JOURNAL of AEROSOL SCIENCE, ISSN: 0021-8502, DOI: 10.1016/j.jaerosci.2014.12.002, Vol.81, pp.75-89, 2015Żywczyk Ł.^{♦}, Moskal A., Modelling of deposition of flexible fractal-like aggregates on cylindrical fibre in continuum regime, JOURNAL of AEROSOL SCIENCE, ISSN: 0021-8502, DOI: 10.1016/j.jaerosci.2014.12.002, Vol.81, pp.75-89, 2015Abstract: A new mathematical model of aggregate composed of N primary spherical particles has been created. The aggregate structure is modelled as an elastic body, capable of undergoing stretching, bending and twisting, during its movement in fluid. An aggregate is defined as a system of spherical particles joined together by springs, and the stiffness of structure is maintained by potential energy functions. Aggregate movement has been tracked in a Kuwabara cell model for three different values of velocity in continuum regime. The deposition efficiency of aggregates on a cylindrical collector has been related to the fractal dimension of aggregates, velocity of air and spring constant, which determine the magnitude of deformation of the aggregate structure. It was found that fractal dimension, velocity of air and imposed parameters of oscillations constants, strongly influence the deposition efficiency of aggregates Keywords: harmonic oscillator equation, potential energy functions, fractal-like aggregates, fractal dimension | | (35p.) |
236. | Jansen K.A., Bacabac R.G., Piechocka I.K.^{♦}, Koenderink G.H., Cells actively stiffen fibrin networks by generating contractile stress, BIOPHYSICAL JOURNAL, ISSN: 0006-3495, DOI: 10.1016/j.bpj.2013.10.008, Vol.105, No.10, pp.2240-2251, 2013Jansen K.A., Bacabac R.G., Piechocka I.K.^{♦}, Koenderink G.H., Cells actively stiffen fibrin networks by generating contractile stress, BIOPHYSICAL JOURNAL, ISSN: 0006-3495, DOI: 10.1016/j.bpj.2013.10.008, Vol.105, No.10, pp.2240-2251, 2013Abstract: During wound healing and angiogenesis, fibrin serves as a provisional extracellular matrix. We use a model system of fibroblasts embedded in fibrin gels to study how cell-mediated contraction may influence the macroscopic mechanical properties of their extracellular matrix during such processes. We demonstrate by macroscopic shear rheology that the cells increase the elastic modulus of the fibrin gels. Microscopy observations show that this stiffening sets in when the cells spread and apply traction forces on the fibrin fibers. We further show that the stiffening response mimics the effect of an external stress applied by mechanical shear. We propose that stiffening is a consequence of active myosin-driven cell contraction, which provokes a nonlinear elastic response of the fibrin matrix. Cell-induced stiffening is limited to a factor 3 even though fibrin gels can in principle stiffen much more before breaking. We discuss this observation in light of recent models of fibrin gel elasticity, and conclude that the fibroblasts pull out floppy modes, such as thermal bending undulations, from the fibrin network, but do not axially stretch the fibers. Our findings are relevant for understanding the role of matrix contraction by cells during wound healing and cancer development, and may provide design parameters for materials to guide morphogenesis in tissue engineering. | | (35p.) |
237. | Piechocka I.K.^{♦}, van Oosten A.S.G., Breuls R.G., Koenderink G.H., Rheology of Heterotypic Collagen Networks, BIOMACROMOLECULES, ISSN: 1525-7797, DOI: 10.1021/bm200553x, Vol.12, No.7, pp.2797-2805, 2011Piechocka I.K.^{♦}, van Oosten A.S.G., Breuls R.G., Koenderink G.H., Rheology of Heterotypic Collagen Networks, BIOMACROMOLECULES, ISSN: 1525-7797, DOI: 10.1021/bm200553x, Vol.12, No.7, pp.2797-2805, 2011Abstract: Collagen fibrils are the main structural element of connective tissues. In many tissues, these fibrils contain two fibrillar collagens (types I and V) in a ratio that changes during tissue development, regeneration, and various diseases. Here we investigate the influence of collagen composition on the structure and rheology of networks of purified collagen I and V, combining fluorescence and atomic force microscopy, turbidimetry, and rheometry. We demonstrate that the network stiffness strongly decreases with increasing collagen V content, even though the network structure does not substantially change. We compare the rheological data with theoretical models for rigid polymers and find that the elasticity is dominated by nonaffine deformations. There is no analytical theory describing this regime, hampering a quantitative interpretation of the influence of collagen V. Our findings are relevant for understanding molecular origins of tissue biomechanics and for guiding rational design of collagenous biomaterials for biomedical applications. | | (40p.) |
238. | Piechocka I.K.^{♦}, Bacabac R.G., Potters M., MacKintosh F.C., Koenderink G.H., Structural Hierarchy Governs Fibrin Gel Mechanics, BIOPHYSICAL JOURNAL, ISSN: 0006-3495, DOI: 10.1016/j.bpj.2010.01.040, Vol.98, No.10, pp.2281-2289, 2010Piechocka I.K.^{♦}, Bacabac R.G., Potters M., MacKintosh F.C., Koenderink G.H., Structural Hierarchy Governs Fibrin Gel Mechanics, BIOPHYSICAL JOURNAL, ISSN: 0006-3495, DOI: 10.1016/j.bpj.2010.01.040, Vol.98, No.10, pp.2281-2289, 2010Abstract: Fibrin gels are responsible for the mechanical strength of blood clots, which are among the most resilient protein materials in nature. Here we investigate the physical origin of this mechanical behavior by performing rheology measurements on reconstituted fibrin gels. We find that increasing levels of shear strain induce a succession of distinct elastic responses that reflect stretching processes on different length scales. We present a theoretical model that explains these observations in terms of the unique hierarchical architecture of the fibers. The fibers are bundles of semiflexible protofibrils that are loosely connected by flexible linker chains. This architecture makes the fibers 100-fold more flexible to bending than anticipated based on their large diameter. Moreover, in contrast with other biopolymers, fibrin fibers intrinsically stiffen when stretched. The resulting hierarchy of elastic regimes explains the incredible resilience of fibrin clots against large deformations. | | (32p.) |
239. | Meissner M., The response of Helmholtz resonator to external excitation. Part I: acoustically induced resonance, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.29, No.1, pp.107-121, 2004Meissner M., The response of Helmholtz resonator to external excitation. Part I: acoustically induced resonance, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.29, No.1, pp.107-121, 2004Abstract: The first of two companion papers theoretical and experimental results are presented for a Helmholtz resonator subject to external excitation by an acoustic plane wave. The response of the resonator was analysed in terms of the relation between the pressure induced in the interior of the resonator and the driving pressure. Equations for the resonance frequency and the quality factor were developed for the cavity that was a rectangular parallelepiped with a centered circular orifice. The flow from the cavity had a constant velocity profile. The resonator was modelled by an equivalent impedance circuit, predicted from the classic theory of sound radiation, with an additional resistive term connected with the viscous action inside the orifice. The theoretical results were compared with experimental data for a frequency chosen so as to tune the system to the lowest resonance mode. The experiment has shown that the acoustic response of resonator was changed considerably when mechanical vibrations of the resonator elements were excited. A phenomenon of flow-induced resonance in the considered system geometry will be presented in the companion paper. Keywords: Helmholtz resonator, flow-induced resonanse, acoustic response of resonator | |
240. | Meissner M., Excitation of Helmholtz resonator by grazing air flow, JOURNAL OF SOUND AND VIBRATION, ISSN: 0022-460X, DOI: 10.1006/jsvi.2001.4219, Vol.256, No.2, pp.382-388, 2002Meissner M., Excitation of Helmholtz resonator by grazing air flow, JOURNAL OF SOUND AND VIBRATION, ISSN: 0022-460X, DOI: 10.1006/jsvi.2001.4219, Vol.256, No.2, pp.382-388, 2002Keywords: cavity resonator, flow-excited sound, Strouhal number | |
241. | Meissner M., Aerodynamically excited acoustic oscillations in cavity resonator exposed to an air jet, ACTA ACUSTICA UNITED WITH ACUSTICA, ISSN: 1610-1928, Vol.88, No.2, pp.170-180, 2002Meissner M., Aerodynamically excited acoustic oscillations in cavity resonator exposed to an air jet, ACTA ACUSTICA UNITED WITH ACUSTICA, ISSN: 1610-1928, Vol.88, No.2, pp.170-180, 2002Abstract: Experimental and theoretical results are presented for a cavity resonator driven by an air jet. Cavity sound spectra have been investigated to found a dependence of sound frequency and amplitude versus jet speed. Two ranges of the jet speed were distinguished. In the stage I, identified with low speed range, the frequency increased fast with jet speed and a frequency increment was proportional to jet speed as in the edge–tones phenomenon. In a stage II, corresponding to higher jet speeds, an increase in the frequency was still observed, but a frequency growth was much smaller. A correlation of experimental data has shown that the observed oscillation amplitudes are within moderate–range. A theoretical model based on moving compact vortices was presented to describe flow–acoustic interaction in a resonator opening and find an aerodynamic force driving a resonator. A response of resonator was modelled by equivalent impedance circuit with added nonlinear term. From final equations a frequency and an amplitude of oscillation were calculated. A support for the proposed theory is provided by favourable comparison between theoretical predictions and experimental data. Keywords: cavity resonator, air jet, sound generation, vortex street | |
242. | Meissner M., Acoustic modes induced by flow in a pipe with two closed side-branches, APPLIED ACOUSTICS, ISSN: 0003-682X, Vol.63, No.10, pp.1071-1083, 2002Meissner M., Acoustic modes induced by flow in a pipe with two closed side-branches, APPLIED ACOUSTICS, ISSN: 0003-682X, Vol.63, No.10, pp.1071-1083, 2002Abstract: An air flow in a pipe with two closed side-branches can induce high pressure pulsations in a pipe system. This phenomenon has been investigated and the results are reported in this paper. A simple theoretical model based on a wave transmission was used to determine a resonance condition associated with an acoustic coupling between branches. In the model a plane wave approximation and an impedance representation of a branch were applied. The experiment was carried out in a pipe system with a relatively large distance between branches compared to branch lengths. A frequency and a pressure of pulsations were measured in a wide range of length of downstream branch. A support for the theory is provided by a favorable comparison between experimental data and calculated resonant frequencies of the system. Keywords: pipe system, closed side-branches, acoustic resonance | |
243. | Meissner M., Absorption properties of Helmholtz resonator at high amplitude incident sound, ACTA ACUSTICA UNITED WITH ACUSTICA, ISSN: 1610-1928, Vol.86, No.6, pp.985-991, 2000Meissner M., Absorption properties of Helmholtz resonator at high amplitude incident sound, ACTA ACUSTICA UNITED WITH ACUSTICA, ISSN: 1610-1928, Vol.86, No.6, pp.985-991, 2000Abstract: The sound attenuation in a Helmholtz resonator subjected to a plane incident wave is examined. The resonator closing a tube is considered. The average acoustic power absorbed by vortical field has been calculated in the low frequency range with the aid of the appropriate conservation equations. Considering this power loss and losses due to viscous damping inside the resonator orifice, the change of absorption properties of the resonator is analyzed. Results of this study indicate that the peak of the absorption coefficient occurs when the loss resistance is equal to the radiation resistance. Plots of the theoretically predicted absorption coefficient and normalized loss resistance as a function of incident pressure amplitude are in good agreement with experimental data obtained for different orifice diameters. Keywords: Helmholtz resonator, sound absorption, nonlinear resistance | |
244. | Meissner M., The influence of acoustic nonlinearity on absorption properties of Helmholtz resonators. Part II: experiment, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.25, No.2, pp.175-190, 2000Meissner M., The influence of acoustic nonlinearity on absorption properties of Helmholtz resonators. Part II: experiment, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.25, No.2, pp.175-190, 2000Abstract: An experimental study of an effect of the acoustic nonlinearity on absorption properties of Helmholtz resonators is presented in this work. By use of the classical standing wave method the changes in the absorption coefficient and the resonators impedance were investigated at moderate and high amplitudes of incident wave. As a result of nonlinearity a high absorption at resonance frequencies was observed and then a decrease in this absorption with increasing amplitude. Measurements of the total loss resistance of resonators have indicated that a change in the resistance at high amplitudes depends strongly on resonator orifice area, the smaller area - the higher increase in the resistance. The experimental results have also shown a growth in resonators reactance which causes an increase in resonance frequency. Quite a good agreement between experimental data and the theory presented in Part I was found. Keywords: Helmholtz resonator, acoustic nonlinearity, absorption coefficient | |
245. | Meissner M., The influence of acoustic nonlinearity on absorption properties of Helmholtz resonators. Part I: theory, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.24, No.2, pp.179-190, 1999Meissner M., The influence of acoustic nonlinearity on absorption properties of Helmholtz resonators. Part I: theory, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.24, No.2, pp.179-190, 1999Abstract: This is the first of two companion papers concerned with the nonlinear absorption of Helmholtz resonators at a high amplitude incident wave. The phenomenon has been examined theoretically by use of a model of the acoustic field in the neighborhood of the resonator placed at the end of cylindrical tube. The calculation results have shown that the peak of the absorption coeficient occurs when the nonlinear resistance is equal to the radiation resistance of the resonator. The full experimental investigations of this phenomenon and a comparison between theoretical and experimental data will be presented in the companion paper (Part II). Keywords: Helmholtz resonator, nonlinear sound absorption, high amplitude incident sound | |
246. | Meissner M., Flow–excited acoustic pulsations in ducts with closed side branches, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.22, No.2, pp.153-167, 1997Meissner M., Flow–excited acoustic pulsations in ducts with closed side branches, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.22, No.2, pp.153-167, 1997Abstract: In flow ducts with closed side branches strong acoustic pulsations are often induced. This was shown by test results performed for systems with a single side branch and co-axial branches with the same lengths. With growing the flow velocity an excitation of successive resonant modes was observed. Their frequencies were increased together with the flow velocity but at peaks of sound pressure there was an excellent agreement between measurements results and theoretical predictions. A conversion of fluctuating flow energy to energy of resonant acoustic field was included in theoretical consideration by means of negative resistance in impedance model of branches. Hence, it was possible to predict a stronger nonlinearity in the case of a duct with co-axial branches. It was found that a characteristic parameter of the analyzed phenomenon is Strouhal number. Its values for all modes are within the same range approximately and, in addition, it determines a change of acoustic inertance at the branch opening. Keywords: closed side branches, Strouhal number, resonant modes | |
247. | Meissner M., Czechowicz M., Experimental investigation of flow-induced acoustic oscillations in piping system with closed branches, APPLIED ACOUSTICS, ISSN: 0003-682X, Vol.45, No.4, pp.359-375, 1995Meissner M., Czechowicz M., Experimental investigation of flow-induced acoustic oscillations in piping system with closed branches, APPLIED ACOUSTICS, ISSN: 0003-682X, Vol.45, No.4, pp.359-375, 1995Abstract: An experimental study of flow-excited acoustic oscillations in piping systems with closed branches is presented in this paper. An influence of acoustic interactions between branches on a generated sound was investigated in arrangements with two and three branches. Significant changes of frequency and level of oscillation in terms of branch lengths were observed. In the system with three branches, at the specified lengths of one branch, a cancellation of oscillations was noticed. Keywords: piping system, closed side branches, flow-induced oscillations | |
248. | Meissner M., Ranachowski Z., Modelling of acoustic emission sources, ACTA ACUSTICA UNITED WITH ACUSTICA, ISSN: 1610-1928, Vol.79, No.2, pp.186-189, 1993Meissner M., Ranachowski Z., Modelling of acoustic emission sources, ACTA ACUSTICA UNITED WITH ACUSTICA, ISSN: 1610-1928, Vol.79, No.2, pp.186-189, 1993Keywords: acoustic emission, plate vibrations, frequency spectrum | |
249. | Meissner M., Discrete sound induced by low Mach number flow over side branch deep cavity in a rectangular duct, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.17, No.2, pp.287-305, 1992Meissner M., Discrete sound induced by low Mach number flow over side branch deep cavity in a rectangular duct, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.17, No.2, pp.287-305, 1992Abstract: This paper presents the model of the discrete sound induction effect due to a flow over deep cavity in the wall of a rectangular duct. Theoretical analysis applies shear layer approximation with a vortex sheet, with deflection satisfying the Kutta-Żukowski condition, and an equivalent impedance system of a deep cavity with cavity impedance change in the presence of the flow included. The applied theoreticl method makes it possible to determine the effect of resonanse modes of the cavity on disturbances of the vortex sheet and also to determine the frequency and relative value of pressure amplitude in the case of a discrete sound. Keywords: discrete sound generation, vortex sheet, deep cavity | |
250. | Meissner M., Self-sustained deep cavity oscillations induced by grazing flow, ACTA ACUSTICA UNITED WITH ACUSTICA, ISSN: 1610-1928, Vol.62, No.3, pp.220-228, 1987Meissner M., Self-sustained deep cavity oscillations induced by grazing flow, ACTA ACUSTICA UNITED WITH ACUSTICA, ISSN: 1610-1928, Vol.62, No.3, pp.220-228, 1987Abstract: This paper is concerned with a model of sound generation in a case of the deep cavity exposed to a grazing mean air flow. The problem was analyzed theoretically by means of infinitely thin shear layer assumption and the description of acoustic response of the cavity. The response was determined with the aid of the impedance model of flow excited quarter-wave resonator, including the nonlinear orifice damping. The parameters of unstable motion in the slot were found, basing on continuity conditions across the orifice plane. Calculated values were used in order to determine the acoustic pressure in far-field area. The theoretical predictions were compared to experimental results. Keywords: deep cavity, discrete sound generation, grazing flow | |