Publications reported by three months

1.Graczykowski C., Faraj R., Development of control systems for fluid-based adaptive impact absorbers, MECHANICAL SYSTEMS AND SIGNAL PROCESSING, ISSN: 0888-3270, DOI: 10.1016/j.ymssp.2018.12.006, Vol.122, No.2019, pp.622-641, 2019
Graczykowski C., Faraj R., Development of control systems for fluid-based adaptive impact absorbers, MECHANICAL SYSTEMS AND SIGNAL PROCESSING, ISSN: 0888-3270, DOI: 10.1016/j.ymssp.2018.12.006, Vol.122, No.2019, pp.622-641, 2019

Abstract:
The paper presents development, evaluation and comparison of various control systems for adaptive fluid-based absorbers serving for absorption of the impact loading. The investigations concern two competitive approaches: i) standard control systems with single determination of the optimal system path based on identified impact conditions, and ii) newly-developed control systems with on-line determination and update of the system path during the process. It is revealed that low robustness of the standard control systems to imprecise impact identification and unknown disturbances results from the assumed path-determination approach and utilized simple path-tracking methods. The proposed solution to this problem is application of the innovative control systems, which utilize Automatic Path Finding and Automatic Path Update algorithms based on full kinematic feedback as well as Hybrid Path Tracking method dedicated for fluid-based absorbers. The introduced approach to absorber control is used to develop three different self-adaptive systems of increasing complexity and robustness. The favourable capabilities of proposed systems including no need for impact identification, high robustness against force disturbances and reduction of leakages influence are proved. Detailed discussion is presented using the illustrative example of single-chamber adaptive pneumatic shock-absorber mitigating impact loading.

Keywords:
Adaptive Impact Absorption, Automatic Path Finding, Automatic Path Update, Full kinematic feedback, Hybrid Path Tracking, Self-adaptive system, Pneumatic shock-absorber

2.Chikahiro Y., Ario I., Pawłowski P., Graczykowski C., Holnicki-Szulc J., Optimization of reinforcement layout of scissor-type bridge using differential evolution algorithm, Computer-Aided Civil and Infrastructure Engineering, ISSN: 1093-9687, DOI: 10.1111/mice.12432, pp.1-16, 2019
Chikahiro Y., Ario I., Pawłowski P., Graczykowski C., Holnicki-Szulc J., Optimization of reinforcement layout of scissor-type bridge using differential evolution algorithm, Computer-Aided Civil and Infrastructure Engineering, ISSN: 1093-9687, DOI: 10.1111/mice.12432, pp.1-16, 2019

Abstract:
Scissors mechanisms are commonly used in safety engineering during the construction of temporary structures, owing to their inherent advantages of foldability, transformability, and reusability.We effectively utilized these scissors mechanism features to develop a lightweight, deployable emergency Mobile Bridge (MB) based on optimization, and control of the folding structure. Here, we discuss the problems of optimal reinforcement layout for the MB by formulating and solving three optimization problems, namely: (a) the load capacity maximization problem, (b) the weight minimization problem, and (c) coupling the load capacity maximization problem and the weight minimization problem. The potential benefits resulting from the application of reinforcement were evaluated using a combination of finite element analysis and an optimization algorithm based on the differential evolution method. The results demonstrate the significant positive influence of the additional reinforcing members. In particular, the limit load was increased by over 10 times, while the weight was decreased to approximately half. The proposed methodology enabled the development of a substantially improved version of the MB characterized by a higher load capacity and lower weight in comparison to the initial bridge design.

3.von Tiedemann P., Maciol K., Preis J., Sajkiewicz P., Frey H., Rapid One-Pot Synthesis of Tapered Star Copolymers via Ultra-Fast Coupling of Polystyryllithium Chain Ends, Polymer Chemistry, ISSN: 1759-9954, DOI: 10.1039/C8PY01656A, pp.1-7, 2019
von Tiedemann P., Maciol K., Preis J., Sajkiewicz P., Frey H., Rapid One-Pot Synthesis of Tapered Star Copolymers via Ultra-Fast Coupling of Polystyryllithium Chain Ends, Polymer Chemistry, ISSN: 1759-9954, DOI: 10.1039/C8PY01656A, pp.1-7, 2019

Abstract:
Highly efficient stoichiometric coupling of sterically hindered polystyryllithium (PS-Li) chain ends was achieved using tetra[3-(chloro-dimethylsilyl)propyl]silane (TCDMSPS) as the linking agent. Based on the disparate reactivities of isoprene (I, rI = 11.0) and styrene (S, rS = 0.049) in the anionic copolymerization in nonpolar media, poly(isoprene0.5-grad-styrene0.5) (P(I0.5-grad-S0.5)) tapered 4-arm star copolymers were synthesized in only two steps. The tapered 4-arm star copolymers (Mwtargeted = 40 to 160 kg mol-1) were synthesized with high star functionalities f (Mw,star/Mw,arm = 3.68 – 3.98), low dispersity (Ð = 1.08 – 1.15) and minimal residual precursor content (2-8 wt%), avoiding fractionation or other purification methods. Coupling kinetics measurements revealed that for the synthesis of polystyrene (PS) 4-arm stars (12 kg mol-1) a coupling efficiency of 98% was already achieved within 2 minutes. All star polymers were analyzed by size exclusion chromatography (SEC) viscometry with universal calibration (UC) as well as NMR spectroscopy. Well-defined nanofibers from the tapered copolymer stars were obtained via electrospinning.

4.Madan N., Rojek J., Nosewicz S., Convergence and stability analysis of the deformable discrete element method, INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, ISSN: 0029-5981, DOI: 10.1002/nme.6014, pp.1-22, 2019
Madan N., Rojek J., Nosewicz S., Convergence and stability analysis of the deformable discrete element method, INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, ISSN: 0029-5981, DOI: 10.1002/nme.6014, pp.1-22, 2019

Abstract:
This work investigates numerical properties of the algorithm of the discrete element method employing deformable circular discs presented in an earlier authors' publication. The new formulation, called the deformable discrete element method (DDEM) enhances the standard discrete element method (DEM) by introducing an additional (global) deformation mode caused by the stresses in the particles induced by the contact forces. An accurate computation of the contact forces would require an iterative solution of the implicit relationship between the contact forces and particle displacements. In order to preserve efficiency of the DEM, the new formulation has been adapted to the explicit time integration. It has been shown that the explicit DDEM algorithm is conditionally stable and there are two restrictions on its stability. Except for the limitation of the time step as in the standard DEM, the stability in the DDEM is governed by the convergence criterion of the iterative solution of the contact forces. The convergence and stability limits have been determined analytically and numerically for selected regular and irregular configurations. It has also been found out that the critical time step in DDEM remains unchanged with respect to standard DEM.

Keywords:
discrete element method; deformable particles; iterative solution; convergence criterion;explicit scheme; stability

5.Sadowski Ł., Piechówka-Mielnik M., Widziszowski T., Gardynik A., Mackiewicz S., Hybrid ultrasonic-neural prediction of the compressive strength of environmentally friendly concrete screeds with high volume of waste quartz mineral dust, Journal of Cleaner Production, ISSN: 0959-6526, DOI: 10.1016/j.jclepro.2018.12.059, Vol.212, pp.727-740, 2019
Sadowski Ł., Piechówka-Mielnik M., Widziszowski T., Gardynik A., Mackiewicz S., Hybrid ultrasonic-neural prediction of the compressive strength of environmentally friendly concrete screeds with high volume of waste quartz mineral dust, Journal of Cleaner Production, ISSN: 0959-6526, DOI: 10.1016/j.jclepro.2018.12.059, Vol.212, pp.727-740, 2019

Abstract:
The article presents the hybrid ultrasonic-neural assessment of the compressive strength of low-strength concrete screeds modified using high volume of mineral dusts sourced from industrial wastes. Quartz and quartz-feldspar dusts were selected to replace up to the 60% of the cement mass. The principal aim of this study is to carry out a systematic investigation of the effect of the addition of selected dusts on the compressive strength of such modified concrete screeds. The ultrasonic pulse velocity (UPV) technique was used for this purpose. After UPV analysis, about 13 different compositions were tested after 28 days for their compressive strengths (ranging from about 4 to 16 MPa). The relationship between the ultrasound velocity and compressive strength of the low-strength concrete screeds was found to be not acceptable. Finally, the artificial neural networks (ANNs) were employed to predict the compressive strength based on the composition of the concrete and UPV velocity. The obtained values of linear correlation coefficient (R) equal to 0.93, 0.91 and 0.94 respectively for learning, testing and validation phase were satisfactory for reliable evaluation of the compressive strength of environmentally friendly low-strength concrete screeds modified using high volume of waste quartz mineral dusts

Keywords:
Partial replacement of ordinary cement with waste quartz dusts was studied, The utilization of waste quartz mineral dust in concrete screeds was promising, Hybrid ultrasonic-neural prediction of the compressive strength was presented, Waste quartz mineral dusts can be used in screeds for nonstructural applications, The algorithm Broyden-Fletcher-Goldfarb-Shanno (BFGS) was selected

6.Chmielewski M., Nosewicz S., Wyszkowska E., Kurpaska Ł., Strojny-Nędza A., Piątkowska A., Bazarnik P., Pietrzak K., Analysis of the micromechanical properties of copper-silicon carbide composites using nanoindentation measurements, CERAMICS INTERNATIONAL, ISSN: 0272-8842, DOI: 10.1016/j.ceramint.2019.01.257, Vol.45, No.7A, pp.9164-9173, 2019
Chmielewski M., Nosewicz S., Wyszkowska E., Kurpaska Ł., Strojny-Nędza A., Piątkowska A., Bazarnik P., Pietrzak K., Analysis of the micromechanical properties of copper-silicon carbide composites using nanoindentation measurements, CERAMICS INTERNATIONAL, ISSN: 0272-8842, DOI: 10.1016/j.ceramint.2019.01.257, Vol.45, No.7A, pp.9164-9173, 2019

Abstract:
The study presents a detailed analysis of the impact of the coating type of silicon carbide particles and its share by volume on the microstructure and micromechanical properties of Cu-SiC composites. In order to protect the carbide from decomposition during the manufacturing of the composites, the surface of SiC was modified via a plasma vapour deposition technique with a layer of metals (W, Cr, Ti and Ni). Composites with a variable share of the ceramic phase (10–50 %vol.) were obtained at a temperature of 950 °C using spark plasma sintering. An analysis of the structures of the composites, especially in the metal-ceramic boundary region, was conducted with the use of scanning and transmission electron microscopy. The mechanical properties of the composites in the Cu-interface-SiC system were studied via a nanoindentation technique. The comparison of the results of hardness and Young's modulus studies were completed in relation to the actual structures of the materials, which in turn made it possible to determine the impact of the interfacial structure on the global properties of the composite materials.

Keywords:
Copper-silicon carbide composites; Nanoindentation; SPS; Interface study

7.Postek E., Sadowski T., Impact model of WC/Co composite, COMPOSITE STRUCTURES, ISSN: 0263-8223, DOI: 10.1016/j.compstruct.2019.01.084, No.213, pp.231-242, 2019
Postek E., Sadowski T., Impact model of WC/Co composite, COMPOSITE STRUCTURES, ISSN: 0263-8223, DOI: 10.1016/j.compstruct.2019.01.084, No.213, pp.231-242, 2019

Abstract:
WC/Co composite is a standard hard material used for the production of cutting tools. It has both very good thermo-mechanical and wear properties. During the cutting, process tools are subjected to impact loading and gradual degradation due to high-stress concentrations. This loading induced deterioration is complex process still not well investigated and explained.Up till now the dynamic response of the WC/Co composite was analysed under dynamic impulse compressive loading [1]. However, the behaviour of the above two-phase composite under impacts conditions was not investigated in details. In the presented micromechanical approach the real material structure geometry of the internal structure can be performed including spatial distribution of: (1) WC grains and their dimensions, (2) volume content of plastic Co binder with their thickness, (3) system of grain/binder interfaces and (4) cracks initiated and developed during impulse loading, (5) possible brittle grains rotation.The results reveal the dependence of the microcracking processes and the stress distribution on impact velocity and presence of discontinuities in the Co binder and the interface zone between the binders and the grains. The microcracks system was evaluated by the damage parameter according to Kachanov, 1986 [62].

Keywords:
Cermet; Impact load; Microcracking; Cohesive elements; Numerical modelling;

8.Massaq A., Rusinek A., Klosak M., Bahi S., Arias A., Strain rate effect on the mechanical behavior of polyamide composites under compression loading, COMPOSITE STRUCTURES, ISSN: 0263-8223, DOI: 10.1016/j.compstruct.2019.01.101, Vol.214, pp.114-122, 2019
Massaq A., Rusinek A., Klosak M., Bahi S., Arias A., Strain rate effect on the mechanical behavior of polyamide composites under compression loading, COMPOSITE STRUCTURES, ISSN: 0263-8223, DOI: 10.1016/j.compstruct.2019.01.101, Vol.214, pp.114-122, 2019

Abstract:
This paper presents an experimental study on the effect of strain rate on the compressive behavior of polyamide composites. Contrary to thermoset woven reinforced composites, thermoplastic woven reinforced composites have always received less interest despite its excellent damage and impact resistances. In this context, this work aims to study the behavior of fiber reinforced thermoplastic composites submitted to high strain rate in compression. The tested material is a thermoplastic composite made of armor tissue of equilibrate glass fiber and the matrix is composed of Polyamide 6 (PA6/Glass). The material is prepared with the fibers woven in 0/90 direction.The compressive mechanical response of PA6/Glass composite was determined in the transverse and longitudinal fibers directions at quasi-static and high strain rates. The hydraulic machine and Split Hopkinson Pressure Bar experiments were conducted to determine the dynamic and quasi static compressive deformation and fracture of the PA6/Glass at strain rates from 10−5 s−1 to 1 s−1 and 100 s−1 to 2500 s−1, respectively.In this work, the main goals were to determine the strain rate effect on: elastic modulus, failure stress and failure energy as a function of the loading direction. The strain rate sensitivity of the failure stress level and failure energy were observed. In addition, the failure mechanism was characterized by examining the fracture surfaces using the scanning electron microscopy (SEM) method.In quasi-static conditions of loading, the material reached its capacity due to the formation of shear bands, that concerned all three tested compression directions. In dynamics, the failure took place by shearing followed by delamination. In case of dynamic loading in the direction perpendicular to fibers, the observations made by SEM showed that the failure of the composite had a fragile nature.

Keywords:
Woven composite, Dynamic behaviour, Dynamic fracture, Split Hopkinson Pressure Bar, Failure energy, Anisotropy, Strain rate

9.Grabowski F., Czyż P., Kochańczyk M., Lipniacki T., Limits to the rate of information transmission through the MAPK pathway, JOURNAL OF THE ROYAL SOCIETY INTERFACE, ISSN: 1742-5689, DOI: 10.1098/rsif.2018.0792, Vol.16, No.152, pp.20180792-1-10, 2019
Grabowski F., Czyż P., Kochańczyk M., Lipniacki T., Limits to the rate of information transmission through the MAPK pathway, JOURNAL OF THE ROYAL SOCIETY INTERFACE, ISSN: 1742-5689, DOI: 10.1098/rsif.2018.0792, Vol.16, No.152, pp.20180792-1-10, 2019

Abstract:
Two important signalling pathways of NF-κB and ERK transmit merely 1 bit of information about the level of extracellular stimulation. It is thus unclear how such systems can coordinate complex cell responses to external cues. We analyse information transmission in the MAPK/ERK pathway that converts both constant and pulsatile EGF stimulation into pulses of ERK activity. Based on an experimentally verified computational model, we demonstrate that, when input consists of sequences of EGF pulses, transmitted information increases nearly linearly with time. Thus, pulse-interval transcoding allows more information to be relayed than the amplitude–amplitude transcoding considered previously for the ERK and NF-κB pathways. Moreover, the information channel capacity C, or simply bitrate, is not limited by the bandwidth B = 1/τ, where τ ≈ 1 h is the relaxation time. Specifically, when the input is provided in the form of sequences of short binary EGF pulses separated by intervals that are multiples of τ/n (but not shorter than τ), then for n = 2, C ≈ 1.39 bit/h; and for n = 4, C ≈ 1.86 bit/h. The capability to respond to random sequences of EGF pulses enables cells to propagate spontaneous ERK activity waves across tissue.

Keywords:
cellular signal transduction, pulsatile stimulation, pulse-interval transcoding, bandwidth, representation problem

10.Ryś M., Egner H., Energy equivalence based constitutive model of austenitic stainless steel at cryogenic temperatures, INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, ISSN: 0020-7683, DOI: 10.1016/j.ijsolstr.2018.12.028, Vol.164, pp.52-65, 2019
Ryś M., Egner H., Energy equivalence based constitutive model of austenitic stainless steel at cryogenic temperatures, INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, ISSN: 0020-7683, DOI: 10.1016/j.ijsolstr.2018.12.028, Vol.164, pp.52-65, 2019

Abstract:
In the present work the constitutive model of 316L and 304 stainless steel subjected to mechanical loading at cryogenic temperatures is derived. Three main coupled dissipative phenomena taking place in the material: plastic flow, plastic strain-induced transformation from the primary phase (γ) to the secondary phase (α′), and evolution of micro-damage are considered using a thermodynamically consistent framework. The approach based on total energy equivalence, originally developed for damaged materials, is here extended to modelling not only damage but also phase transformation, in a consistent manner. The proposed model is implemented numerically and validated by means of parametric studies, and by comparison with the experimental results. Very good qualitative and quantitative results are obtained.

Keywords:
Constitutive modelling, Plasticity, Damage, Phase transformation, Cryogenic temperatures

11.Pręgowska A., Kaplan E., Szczepański J., How Far can Neural Correlations Reduce Uncertainty? Comparison of Information Transmission Rates for Markov and Bernoulli Processes, International Journal of Neural Systems, ISSN: 0129-0657, DOI: 10.1142/S0129065719500035, Vol.29, No.0, pp.1950003-1-13, 2019
Pręgowska A., Kaplan E., Szczepański J., How Far can Neural Correlations Reduce Uncertainty? Comparison of Information Transmission Rates for Markov and Bernoulli Processes, International Journal of Neural Systems, ISSN: 0129-0657, DOI: 10.1142/S0129065719500035, Vol.29, No.0, pp.1950003-1-13, 2019

Abstract:
The nature of neural codes is central to neuroscience. Do neurons encode information through relatively slow changes in the firing rates of individual spikes (rate code) or by the precise timing of every spike (temporal code)? Here we compare the loss of information due to correlations for these two possible neural codes. The essence of Shannon’s definition of information is to combine information with uncertainty: the higher the uncertainty of a given event, the more information is conveyed by that event. Correlations can reduce uncertainty or the amount of information, but by how much? In this paper we address this question by a direct comparison of the information per symbol conveyed by the words coming from a binary Markov source (temporal code) with the information per symbol coming from the corresponding Bernoulli source (uncorrelated, rate code). In a previous paper we found that a crucial role in the relation between information transmission rates (ITRs) and firing rates is played by a parameter s, which is the sum of transition probabilities from the no-spike state to the spike state and vice versa. We found that in this case too a crucial role is played by the same parameter s. We calculated the maximal and minimal bounds of the quotient of ITRs for these sources. Next, making use of the entropy grouping axiom, we determined the loss of information in a Markov source compared with the information in the corresponding Bernoulli source for a given word length. Our results show that in the case of correlated signals the loss of information is relatively small, and thus temporal codes, which are more energetically efficient, can replace rate codes effectively. These results were confirmed by experiments.

Keywords:
Shannon information theory, information source, information transmission rate, firing rate, neural coding

12.Jaskulski R., Glinicki M.A., Ranachowski Z., Kubissa W., Organic phosphorus compounds as heat release regulators in hardening shielding concrete, CONSTRUCTION AND BUILDING MATERIALS, ISSN: 0950-0618, DOI: 10.1016/j.conbuildmat.2019.03.081, Vol.209, pp.167-175, 2019
Jaskulski R., Glinicki M.A., Ranachowski Z., Kubissa W., Organic phosphorus compounds as heat release regulators in hardening shielding concrete, CONSTRUCTION AND BUILDING MATERIALS, ISSN: 0950-0618, DOI: 10.1016/j.conbuildmat.2019.03.081, Vol.209, pp.167-175, 2019

Abstract:
The paper presents the results of the study of the influence of the addition of retarding superplasticising admixture based on triisobutyl phosphate and modified phosphonates on the amount of heat generated by hardening shielding concrete. A four-point measurement of the heat generated during the hardening of concrete with an admixture dose of 0, 0.5, 1.0 and 2.0% by weight of the cement was made and the concurrent measurement of the heat released by the hardening cement paste was measured with an isothermal calorimeter. Based on the results from the calorimeter, the effect of the admixture on the temperature field in the hardening concrete mass elements was simulated for different aggregates. The results indicate that the admixture clearly lowers the temperature gradient in hardening mass concrete. In the simulations, the most clear effect was achieved in the case of concrete with barite aggregate, where the gradient value was reduced from 10C/m to 8C/m for an admixture content equal to 2.0%.  2019 Elsevier Ltd. All rights reserved.

Keywords:
Temperature gradient, Heat release, Shielding concrete, Mass concrete, Fresh concrete, Phosphorus compounds

13.Pisarski D., Myśliński A., Suboptimal distributed state-feedback control of semi-active vibrating systems, JOURNAL OF SOUND AND VIBRATION, ISSN: 0022-460X, DOI: 10.1016/j.jsv.2018.12.009, Vol.443, pp.637-651, 2019
Pisarski D., Myśliński A., Suboptimal distributed state-feedback control of semi-active vibrating systems, JOURNAL OF SOUND AND VIBRATION, ISSN: 0022-460X, DOI: 10.1016/j.jsv.2018.12.009, Vol.443, pp.637-651, 2019

Abstract:
A novel semi-active control method for mitigating structural vibration is studied. The method relies on distributed state information patterns and the solution to a suboptimal control problem that aims at replicating the switched structures of the optimal open-loop stabilizing controls. The optimality conditions and the method of solution of the suboptimal problem are discussed. The performance of this method is examined by means of numerical experiments performed for a double cantilever system equipped with a set of semi-active elastomers with controlled viscoelastic properties. The experiments were carried out for different controller architectures and a series of initial conditions. In terms of the assumed objectives, the proposed distributed control strategy significantly outperforms the passive damping strategies and is competitive with a standard centralized control. The proposed approach is general to a class of bilinear control systems concerned with smart structural elements. The practical aspects of the designed distributed controller are highlighted.

Keywords:
distributed control, optimal control, bilinear system, stabilization, semi-active structure

14.Li Z., Qu H., Chen F., Wang Y., Tan Z., Kopeć M., Wang K., Zheng K., Deformation Behavior and Microstructural Evolution during Hot Stamping of TA15 Sheets: Experimentation and Modelling, Materials, ISSN: 1996-1944, DOI: 10.3390/ma12020223, Vol.12, No.2-223, pp.1-14, 2019
Li Z., Qu H., Chen F., Wang Y., Tan Z., Kopeć M., Wang K., Zheng K., Deformation Behavior and Microstructural Evolution during Hot Stamping of TA15 Sheets: Experimentation and Modelling, Materials, ISSN: 1996-1944, DOI: 10.3390/ma12020223, Vol.12, No.2-223, pp.1-14, 2019

Abstract:
Near- α titanium alloys have extensive applications in high temperature structural components of aircrafts. To manufacture complex-shaped titanium alloy panel parts with desired microstructure and good properties, an innovative low-cost hot stamping process for titanium alloy was studied in this paper. Firstly, a series of hot tensile tests and Scanning Electron Microscope (SEM) observations were performed to investigate hot deformation characteristics and identify typical microstructural evolutions. The optimal forming temperature range is determined to be from 750 °C to 900 °C for hot stamping of TA15. In addition, a unified mechanisms-based material model for TA15 titanium alloy based on the softening mechanisms of recrystallization and damage was established, which enables to precisely predict stress-strain behaviors and potentially to be implemented into Finite Element (FE) simulations for designing the reasonable processing window of structural parts for the aerospace industry

Keywords:
TA15, hot stamping, phase evolution, deformation, modelling

15.Nosewicz S., Rojek J., Chmielewski M., Pietrzak K., Discrete Element Modeling of Intermetallic Matrix Composite Manufacturing by Powder Metallurgy, Materials, ISSN: 1996-1944, DOI: 10.3390/ma12020281, Vol.12, No.281, pp.1-18, 2019
Nosewicz S., Rojek J., Chmielewski M., Pietrzak K., Discrete Element Modeling of Intermetallic Matrix Composite Manufacturing by Powder Metallurgy, Materials, ISSN: 1996-1944, DOI: 10.3390/ma12020281, Vol.12, No.281, pp.1-18, 2019

Abstract:
This paper presents a numerical and experimental analysis of manufacturing of intermetallic ceramic composites by powder metallurgy techniques. The scope of the paper includes the formulation and development of an original numerical model of powder metallurgy of two-phase material within the framework of the discrete element method, simulations of powder metallurgy processes for different combinations of process parameters, and a verification of the numerical model based on own experimental results. Intermetallic-based composite NiAl–Al2O3 has been selected as representative material for experimental and numerical studies in this investigation. Special emphasis was given to the interactions between the intermetallic and ceramic particles by formulating the special model for adhesive contact bond. In order to properly represent a real microstructure of a two-phase sintered body, a discrete element specimen was generated using a special algorithm. Numerical validation showed the correct numerical representation of a sintered two-phase composite specimen. Finally, micromechanical analysis was performed to explain the macroscopic behavior of the sintered sample. The evolution of the coordination number, a number of equilibrium contacts, and the distribution of the cohesive neck size with respect to time are presented.

Keywords:
powder metallurgy; sintering; discrete element method; modeling; intermetallic matrix composites

16.Chrzanowska-Giżyńska J., Denis P., Giżyński M., Kurpaska Ł., Mihailescu I., Ristoscu C., Szymański Z., Mościcki T., Thin WBx and WyTi1−yBx films deposited by combined magnetron sputtering and pulsed laser deposition technique, APPLIED SURFACE SCIENCE, ISSN: 0169-4332, DOI: 10.1016/j.apsusc.2019.02.006, Vol.478, pp.505-513, 2019
Chrzanowska-Giżyńska J., Denis P., Giżyński M., Kurpaska Ł., Mihailescu I., Ristoscu C., Szymański Z., Mościcki T., Thin WBx and WyTi1−yBx films deposited by combined magnetron sputtering and pulsed laser deposition technique, APPLIED SURFACE SCIENCE, ISSN: 0169-4332, DOI: 10.1016/j.apsusc.2019.02.006, Vol.478, pp.505-513, 2019

Abstract:
The coatings of tungsten borides (WBx) and tungsten borides doped with titanium (WyTi1−yBx) were deposited by using combined magnetron sputtering - pulsed laser deposition technique. In the case of WBx coatings, pure tungsten target was evaporated by a laser pulse at 1064 nm wavelength and pure boron target was sputtered by a magnetron. In the case of WyTi1−yBx coatings, the W2B5 target was sputtered by the magnetron and titanium target was evaporated by the laser pulse at 1064 nm wavelength. The content of titanium dopant changed from 1.1 to 5.5 at.%. The microstructure, chemical and phase composition of deposited coatings were investigated by means of Scanning Electron Microscopy, Energy Dispersive X-Ray Spectroscopy, X-Ray Photoelectron Spectroscopy and X-Ray Diffractometry, respectively. The Vickers hardness and Young's modulus were determined by using the nanoindentation test. Nanocrystalline WB coatings with dominant WB2 phase were obtained at a substrate temperature of 520 °C. The coatings were superhard with a hardness of 47–50 GPa and the mean value of surface roughness was <6 nm. The WBx coatings doped with 5.5 at.% Ti had hardness similar to the coatings sputtered by magnetron from W2B5 target.

Keywords:
The superhard WyBx thin films was deposited with hybrid laser-magnetron technology, The MS-PLD method allows for the deposition of ternary borides such as WyTi1−yBx, The MS-PLD method enables to control the chemical and phase composition of films, The deposited films are smooth with hardness above 50 GPa, Crystalline films were deposited only on a substrate kept an elevated temperature

17.Poma Bernaola A., Guzman V.H., Li M.S., Theodorakis P.E., Mechanical and thermodynamic properties of Aβ42, Aβ40, and α-synuclein fibrils: a coarse-grained method to complement experimental studies, Beilstein Journal of Nanotechnology, ISSN: 2190-4286, DOI: 10.3762/bjnano.10.51, Vol.10, pp.500-513, 2019
Poma Bernaola A., Guzman V.H., Li M.S., Theodorakis P.E., Mechanical and thermodynamic properties of Aβ42, Aβ40, and α-synuclein fibrils: a coarse-grained method to complement experimental studies, Beilstein Journal of Nanotechnology, ISSN: 2190-4286, DOI: 10.3762/bjnano.10.51, Vol.10, pp.500-513, 2019

Abstract:
We perform molecular dynamics simulation on several relevant biological fibrils associated with neurodegenerative diseases such as Aβ40, Aβ42, and α-synuclein systems to obtain a molecular understanding and interpretation of nanomechanical characterization experiments. The computational method is versatile and addresses a new subarea within the mechanical characterization of heterogeneous soft materials. We investigate both the elastic and thermodynamic properties of the biological fibrils in order to substantiate experimental nanomechanical characterization techniques that are quickly developing and reaching dynamic imaging with video rate capabilities. The computational method qualitatively reproduces results of experiments with biological fibrils, validating its use in extrapolation to macroscopic material properties. Our computational techniques can be used for the co-design of new experiments aiming to unveil nanomechanical properties of biological fibrils from a point of view of molecular understanding. Our approach allows a comparison of diverse elastic properties based on different deformations , i.e., tensile (YL), shear (S), and indentation (YT) deformation. From our analysis, we find a significant elastic anisotropy between axial and transverse directions (i.e., YT > YL) for all systems. Interestingly, our results indicate a higher mechanostability of Aβ42 fibrils compared to Aβ40, suggesting a significant correlation between mechanical stability and aggregation propensity (rate) in amyloid systems. That is, the higher the mechanical stability the faster the fibril formation. Finally, we find that α-synuclein fibrils are thermally less stable than β-amyloid fibrils. We anticipate that our molecular-level analysis of the mechanical response under different deformation conditions for the range of fibrils considered here will provide significant insights for the experimental observations.

Keywords:
Alzheimer disease, Parkinson disease, β-amyloid, α-synuclein, molecular dynamics, AFM, indentation, elasticity, protein, fibrils, assemblies, soft matter, Young modulus

18.Yiu B.Y.S., Walczak M., Lewandowski M., Yu A.C.H., Live Ultrasound Color Encoded Speckle Imaging Platform for Real-Time Complex Flow Visualization In Vivo, IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL, ISSN: 0885-3010, DOI: 10.1109/TUFFC.2019.2892731, pp.1-13, 2019
Yiu B.Y.S., Walczak M., Lewandowski M., Yu A.C.H., Live Ultrasound Color Encoded Speckle Imaging Platform for Real-Time Complex Flow Visualization In Vivo, IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL, ISSN: 0885-3010, DOI: 10.1109/TUFFC.2019.2892731, pp.1-13, 2019

Abstract:
Complex flow patterns are prevalent in the vasculature, but they are difficult to image non-invasively in real-time. This paper presents the first real-time scanning platform for a high frame rate ultrasound technique called color encoded speckle imaging (CESI) and its use in visualizing arterial flow dynamics in-vivo. CESI works by simultaneously rendering flow speckles and color-coded flow velocity estimates on a time-resolved basis. Its live implementation was achieved by integrating a 192-channel programmable ultrasound front-end module, a 4.8 GB/s capacity data streaming link, and a series of computing kernels implemented on the graphical processing unit (GPU) for beamforming and Doppler processing. A slow-motion replay mode was also included to offer coherent visualization of CESI frames acquired at high frame rate (3,000 fps in our experiments). The live CESI scanning platform was found to be effective in facilitating real-time image guidance (at least 20 fps for live video display with 55 fps GPU processing throughout). In vivo pilot trials also showed that live CESI, when running in replay mode, can temporally resolve triphasic flow at the brachial bifurcation and can reveal flow dynamics in the brachial vein during a fist-clenching maneuver. Overall, live CESI has potential for use in routine investigations in-vivo that seek to identify complex flow dynamics in real-time and relate these dynamics to vascular physiology.

Keywords:
High frame rate ultrasound, Color encoded speckle imaging, Live scanning platform, Graphical processing units, In-vivo studies, Complex flow visualization

19.Meissner M., Wiśniewski K., Influence of room modes on low-frequency transients: Theoretical modeling and numerical predictions, JOURNAL OF SOUND AND VIBRATION, ISSN: 0022-460X, DOI: 10.1016/j.jsv.2019.02.012, Vol.448, pp.19-33, 2019
Meissner M., Wiśniewski K., Influence of room modes on low-frequency transients: Theoretical modeling and numerical predictions, JOURNAL OF SOUND AND VIBRATION, ISSN: 0022-460X, DOI: 10.1016/j.jsv.2019.02.012, Vol.448, pp.19-33, 2019

Abstract:
In the low-frequency range, a sound reproduction in enclosures is strongly influenced by excited room modes. While the spectral impact of acoustic modes on a room response is well recognized, there is no sufficient knowledge on how these modes affects transients. In the paper this issue has been examined theoretically and numerically for a room excited by a tone burst by using a modal expansion method supported by a computer implementation. To quantify a temporal accuracy of a sound reproduction, the new metrics referred to as the tone burst reproduction error was introduced. The basis for determining this quantity was a deviation between the tone burst amplitude and the amplitude of a sound pressure computed via the Hilbert transform. A numerical simulation was performed for an irregularly shaped enclosure having a form of two-room coupled system. Calculation results have proved that a high inaccuracy of a tone burst reproduction occurs at receiving points corresponding to sharp dips in a distribution of the steady-state sound pressure level. This is because in these points an amplitude of transient sound is much bigger than a tone burst amplitude. It was discovered that strong narrow peaks in the tone burst reproduction error are located at centers of vortices in the active sound intensity vector field. An influence of a sound damping in a room on a reproduction of a tone burst was also examined and it was found that a substantial increase in a wall sound absorption does not significantly improves a tone burst reproduction because it does not eliminate sharp dips in a distribution of the steady-state sound pressure level.

Keywords:
room acoustics, room modes, transients, tone burst, discrete Hilbert transform, sound intensity vector field

20.Ekiel-Jeżewska M.L., Adamczyk Z., Bławzdziewicz J., Streaming Current and Effective ζ-Potential for Particle-Covered Surfaces with Random Particle Distributions, The Journal of Physical Chemistry C, ISSN: 1932-7447, DOI: 10.1021/acs.jpcc.8b10068, Vol.123, No.6, pp.3517-3531, 2019
Ekiel-Jeżewska M.L., Adamczyk Z., Bławzdziewicz J., Streaming Current and Effective ζ-Potential for Particle-Covered Surfaces with Random Particle Distributions, The Journal of Physical Chemistry C, ISSN: 1932-7447, DOI: 10.1021/acs.jpcc.8b10068, Vol.123, No.6, pp.3517-3531, 2019

Abstract:
A detailed theoretical and experimental study is presented concerning the streaming current and the derivative effective ζ-potential for a planar surface covered by a monolayer of adsorbed particles. Precise simulation results are obtained for the equilibrium and random-sequential-adsorption (RSA) distributions of monodisperse spherical particles interacting via the excluded-volume potential. The streaming current is calculated in the thin-double-layer regime for all physically accessible particle area fractions. The results are expressed as a linear combination of the interface and particle contributions DI and DP weighted by the interface and particle ζ-potentials ζI and ζP. We find that in the area-fraction regime where both particle distributions exist, the equilibrium and RSA results for the streaming current are nearly indistinguishable. Our numerical data show that DI exponentially decays to zero when the particle area fraction θ is increased, whereas DP exponentially tends to a linear behavior. The results are described (with the accuracy better than 1.5% of the maximal value) by the exponential and linear plus exponential approximations, with only one fitting parameter. The numerical and theoretical predictions are in agreement with experimental data obtained for a wide range of ζ-potentials of the interface and the particles. Results obtained for a rough surface with spherical asperities indicate that the roughness can reduce the effective ζ-potential (as evaluated from the streaming current) by more than 25%; this prediction is also confirmed by experiments.

21.Kucharski S., Woźniacka S., Size Effect in Single Crystal Copper Examined with Spherical Indenters, METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, ISSN: 1073-5623, DOI: 10.1007/s11661-019-05160-w, pp.1-16, 2019
Kucharski S., Woźniacka S., Size Effect in Single Crystal Copper Examined with Spherical Indenters, METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, ISSN: 1073-5623, DOI: 10.1007/s11661-019-05160-w, pp.1-16, 2019

Abstract:
The increasing hardness with decreasing penetration depth, referred to as indentation size effect (ISE) was previously investigated experimentally and theoretically by many researchers, however the mechanisms responsible for ISE are still being discussed. Generally, ISE is related to the density of geometrically necessary dislocation stored within a small volume beneath the indenter tip. In this study ISE is investigated experimentally in a single crystal copper using spherical indenter tips of different radii. Some new aspects of ISE are shown: a qualitative change of shape of residual impression (pile-up/sink-in pattern) when tip radius or load is modified, an increase of maximum pop-in load with decrease of tip radius as well as the well-known increase of hardness when tip radius decreases are analyzed. As we observe a difference of the residual imprint morphology which depends on tip radius and load, we apply two methods of hardness estimation: true hardness and nominal hardness. The former is determined on the basis of direct measurement of the contact area while accounting for a specific pile-up pattern, while the latter is determined by measuring the contact area using residual penetration depth. We show that hardness–tip radius relationship has a linear form for the nominal hardness and bilinear form for the true hardness.

22.Hou J., Wang P., Jing T., Jankowski Ł., Experimental Study for Damage Identification of Storage Tanks by Adding Virtual Masses, SENSORS, ISSN: 1424-8220, DOI: 10.3390/s19020220, Vol.19, No.2, pp.220-1-17, 2019
Hou J., Wang P., Jing T., Jankowski Ł., Experimental Study for Damage Identification of Storage Tanks by Adding Virtual Masses, SENSORS, ISSN: 1424-8220, DOI: 10.3390/s19020220, Vol.19, No.2, pp.220-1-17, 2019

Abstract:
This research proposes a damage identification approach for storage tanks that is based on adding virtual masses. First, the frequency response function of a structure with additional virtual masses is deduced based on the Virtual Distortion Method (VDM). Subsequently, a Finite Element (FE) model of a storage tank is established to verify the proposed method; the relation between the added virtual masses and the sensitivity of the virtual structure is analyzed to determine the optimal mass and the corresponding frequency with the highest sensitivity with respect to potential damages. Thereupon, the damage can be localized and quantified by comparing the damage factors of substructures. Finally, an experimental study is conducted on a storage tank. The results confirm that the proposed method is feasible and practical, and that it can be applied for damage identification of storage tanks.

Keywords:
damage identification, storage tanks, sensitivity analysis, frequency

23.Hou J., Li Z., Zhang Q., Zhou R., Jankowski Ł., Optimal Placement of Virtual Masses for Structural Damage Identification, SENSORS, ISSN: 1424-8220, DOI: 10.3390/s19020340, Vol.19, No.2, pp.340-1-18, 2019
Hou J., Li Z., Zhang Q., Zhou R., Jankowski Ł., Optimal Placement of Virtual Masses for Structural Damage Identification, SENSORS, ISSN: 1424-8220, DOI: 10.3390/s19020340, Vol.19, No.2, pp.340-1-18, 2019

Abstract:
Adding virtual masses to a structure is an efficient way to generate a large number of natural frequencies for damage identification. The influence of a virtual mass can be expressed by Virtual Distortion Method (VDM) using the response measured by a sensor at the involved point. The proper placement of the virtual masses can improve the accuracy of damage identification, therefore the problem of their optimal placement is studied in this paper. Firstly, the damage sensitivity matrix of the structure with added virtual masses is built. The Volumetric Maximum Criterion of the sensitivity matrix is established to ensure the mutual independence of measurement points for the optimization of mass placement. Secondly, a method of sensitivity analysis and error analysis is proposed to determine the values of the virtual masses, and then an improved version of the Particle Swarm Optimization (PSO) algorithm is proposed for placement optimization of the virtual masses. Finally, the optimized placement is used to identify the damage of structures. The effectiveness of the proposed method is verified by a numerical simulation of a simply supported beam structure and a truss structure.

Keywords:
damage identification, sensor optimization, Virtual Distortion Method (VDM), Particle Swarm Optimization (PSO) algorithm, sensitivity

24.Woźniak M., Chlanda A., Oberbek P., Heljak M., Czarnecka K., Janeta M., John Ł., Binary bioactive glass composite scaffolds for bone tissue engineering—Structure and mechanical properties in micro and nano scale. A preliminary study, Micron, ISSN: 0968-4328, DOI: 10.1016/j.micron.2018.12.006, Vol.119, pp.64-71, 2019
Woźniak M., Chlanda A., Oberbek P., Heljak M., Czarnecka K., Janeta M., John Ł., Binary bioactive glass composite scaffolds for bone tissue engineering—Structure and mechanical properties in micro and nano scale. A preliminary study, Micron, ISSN: 0968-4328, DOI: 10.1016/j.micron.2018.12.006, Vol.119, pp.64-71, 2019

Abstract:
Composite scaffolds of bioactive glass (SiO 2 -CaO) and bioresorbable polyesters: poly- l -lactic acid (PLLA) and polycaprolactone (PCL) were produced by polymer coating of porous foams. Their structure and mechanical properties were investigated in micro and nanoscale, by the means of scanning electron microscopy, PeakForce Quantitative Nanomechanical Property Mapping (PF-QNM) atomic force microscopy, micro-computed tomography and contact angle measurements. This is one of the first studies in which the nanomechanical properties (elastic modulus, adhesion) were measured and mapped simultaneously with topography imaging (PF-QNM AFM) for bioactive glass and bioactive glass – polymer coated scaffolds. Our findings show that polymer coated scaffolds had higher average roughness and lower stiffness in comparison to pure bioactive glass scaffolds. Such coating-dependent scaffold properties may promote different cells-scaffold interaction.

Keywords:
Bone tissue engineering, Composite scaffold, Bioactive glass, Mechanical properties

25.Romelczyk-Baishya B., Lumelskyj D., Stępniewska M., Giżyński M., Pakieła Z., The mechanical properties at room and low temperature of p110 steel characterised by means of small punch test, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.24425/amm.2019.126232, Vol.64, No.1, pp.159-165, 2019
Romelczyk-Baishya B., Lumelskyj D., Stępniewska M., Giżyński M., Pakieła Z., The mechanical properties at room and low temperature of p110 steel characterised by means of small punch test, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.24425/amm.2019.126232, Vol.64, No.1, pp.159-165, 2019

Abstract:
In this paper, small punch test (SPT) which is one of miniaturized samples technique, was employed to characterize the mechanical properties of carbon steel P110. The tests were carried out in the range of –175°C to RT. Results obtained for SPT were compared to those calculated for tensile and Charpy impact test. Based on tensile and SPT parameters numerical model was prepared. 8 mm in diameter and 0.8 mm in height (t) discs with and without notch were employed in this research. The specimens had different depth notch (a) in the range of 0.1 to 0.4 mm. It was estimated that α factor for comparison of Tsp and DBTT for carbon steel P110 is 0.55 and the linear relation is DBTT = 0.55TSPT. The numerical model fit with force – deflection curve of SPT. If the factor of notch depth and samples thickness is higher than 0.3 the fracture mode is transformed from ductile to brittle at –150°C.

Keywords:
small punch test, carbon steel P110, small samples, low temperature, mechanical properties

26.Widłaszewski J., Nowak M., Nowak Z., Kurp P., LASER-ASSISTED THERMOMECHANICAL BENDING OF TUBE PROFILES, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.24425/amm.2019.126268, Vol.64, No.1, pp.421-430, 2019
Widłaszewski J., Nowak M., Nowak Z., Kurp P., LASER-ASSISTED THERMOMECHANICAL BENDING OF TUBE PROFILES, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.24425/amm.2019.126268, Vol.64, No.1, pp.421-430, 2019

Abstract:
The subject of the work is the analysis of thermomechanical bending process of a thin-walled tube made of X5CrNi18-10 stainless steel. The deformation is produced at elevated temperature generated with a laser beam in a specially designed experimental setup. The tube bending process consists of local heating of the tube by a moving laser beam and simultaneous kinematic enforcement of deformation with an actuator and a rotating bending arm. During experimental investigations, the resultant force of the actuator and temperature at the laser spot are recorded. In addition to experimental tests, the bending process of the tube was modelled using the finite element method in the ABAQUS program. For this purpose, the tube deformation process was divided into two sequentially coupled numerical simulations. The first one was the heat transfer analysis for a laser beam moving longitudinally over the tube surface. The second simulation described the process of mechanical bending with the time-varying temperature field obtained in the first simulation. The force and temperature recorded during experiments were used to verify the proposed numerical model. The final stress state and the deformation of the tube after the bending process were analyzed using the numerical solution. The results indicate that the proposed bending method can be successfully used in forming of the thin-walled profiles, in particular, when large bending angles and a small spring-back effect are of interest.

Keywords:
laser forming, laser-assisted bending, numerical modelling

27.Steifer T., Lewandowski M., Ultrasound tissue characterization based on the Lempel–Ziv complexity with application to breast lesion classification, Biomedical Signal Processing and Control, ISSN: 1746-8094, DOI: 10.1016/j.bspc.2019.02.020, Vol.51, pp.235-242, 2019
Steifer T., Lewandowski M., Ultrasound tissue characterization based on the Lempel–Ziv complexity with application to breast lesion classification, Biomedical Signal Processing and Control, ISSN: 1746-8094, DOI: 10.1016/j.bspc.2019.02.020, Vol.51, pp.235-242, 2019

Abstract:
Building upon the recent successes in the application of information-theoretic concepts (e.g. Shannon entropy) in quantitative ultrasound, the authors propose a novel tissue characterization method based on the Lempel–Ziv complexity. In this procedure, standard ultrasound B-Mode images are mapped onto words over finite alphabets before the corresponding Lempel–Ziv complexity of ultrasound images is calculated. Such complexity metric may be used to differentiate between types of tissues. Here, the method is utilized as a binary classifier for the malignancy of breast lesions. The method is tested on OASBUD – an open-access breast lesions image database. Images of 48 malignant and 48 benign lesions were used – two images for each lesion. The new procedure slightly outperforms the state-of-art classifier based on pixel entropy as measured in the size of area under the receiver operating curve (ROC AUC), which suggests that it may serve as a basis for computer-assisted breast cancer ultrasound diagnosis and possibly in other standard applications of the quantitative ultrasound.

Keywords:
A method based on Lempel–Ziv complexity is proposed for quantitative ultrasound tissue characterization, The method is used to classify breast lesions from an open access ultrasound image database, The method performance is compared with entropy-based classifier as entropy is related theoretically to Lempel–Ziv complexity, The new method achieves 0.87 ROC AUC as compared to 0.84 achieved by the reference method

28.Hou J., Wang S., Zhang Q., Jankowski Ł., An Improved Objective Function for Modal-Based Damage Identification Using Substructural Virtual Distortion Method, Applied Sciences, ISSN: 2076-3417, DOI: 10.3390/app9050971, Vol.9, No.5, pp.1-17, 2019
Hou J., Wang S., Zhang Q., Jankowski Ł., An Improved Objective Function for Modal-Based Damage Identification Using Substructural Virtual Distortion Method, Applied Sciences, ISSN: 2076-3417, DOI: 10.3390/app9050971, Vol.9, No.5, pp.1-17, 2019

Abstract:
Damage identification based on modal parameters is an important approach in structural health monitoring (SHM). Generally, traditional objective functions used for damage identification minimize the mismatch between measured modal parameters and the parameters obtained from the finite element (FE) model. However, during the optimization process, the repetitive calculation of structural modes is usually time-consuming and inefficient, especially for large-scale structures. In this paper, an improved objective function is proposed based on certain characteristics of the peaks of the frequency response function (FRF). Traditional objective functions contain terms that quantify modal shapes and/or natural frequencies. Here, it is proposed to replace them by the FRF of the FE model, which allows the repeated full modal analysis to be avoided and thus increases the computational efficiency. Moreover, the efficiency is further enhanced by employing the substructural virtual distortion method (SVDM), which allows the frequency response of the FE model of the damaged structure to be quickly computed without the costly re-analysis of the entire damaged structure. Finally, the effectiveness of the proposed method is verified using an eight-story frame structure model under several damage cases. The damage location and extent of each substructure can be identified accurately with 5% white Gaussian noise, and the optimization efficiency is greatly improved compared with the method using a traditional objective function.

Keywords:
structural health monitoring (SHM), damage identification, substructure, virtual distortion method (VDM), frequency response

29.Dobruch-Sobczak K., Piotrzkowska-Wróblewska H., Klimonda Z., Roszkowska-Purska K., Litniewski J., Ultrasound echogenicity reveals the response of breast cancer to chemotherapy , Clinical Imaging , ISSN: 0899-7071, DOI: 10.1016/j.clinimag.2019.01.021, Vol.55, pp.41-46, 2019
Dobruch-Sobczak K., Piotrzkowska-Wróblewska H., Klimonda Z., Roszkowska-Purska K., Litniewski J., Ultrasound echogenicity reveals the response of breast cancer to chemotherapy , Clinical Imaging , ISSN: 0899-7071, DOI: 10.1016/j.clinimag.2019.01.021, Vol.55, pp.41-46, 2019

Abstract:
Purpose: To evaluate the ultrasound (US) response in patients with breast cancer (BC) during neoadjuvant chemotherapy (NAC). Methods: Prospective US analysis was performed on 19 malignant tumors prior to NAC treatment and 7days after each first four courses of NAC in 13 patients (median age=57years). Echogenicity, size, vascularity, and sonoelastography were measured and compared with posttreatment scores of residual cancers burden. Results: Changes in the echogenicity of tumors after 3 courses of NAC had the most statistically strong correlation with the percentage of residual malignant cells used in histopathology to assess the response to treatment (odds ratio=60, p < 0.05). Changes in lesion size and elasticity were also significant (p < 0.05). Conclusions: There is a statistically significant relationship between breast tumors' echogenicity in US, neoplasm size, and stiffness and the response to NAC. In particular, our results show that the change in tumor echogenicity could predict a pathological response with satisfactory accuracy and may be considered in NAC monitoring.

Keywords:
Breast ultrasonography, Neoadjuvant chemotherapy, Clinical response, Breast cancer, Sonoelastography

30.Stasiakiewicz P., Dobrowolski A.P., Olszewski R., Gałązka-Świderek N., Targowski T., Skoczylas A., Majka K., Lejkowski W., Klasyfikacja szmerów oddechowych –badania pilotażowe, ELEKTRONIKA - KONSTRUKCJE, TECHNOLOGIE, ZASTOSOWANIA, ISSN: 0033-2089, DOI: 10.15199/13.2019.2.1, Vol.2, pp.4-12, 2019
Stasiakiewicz P., Dobrowolski A.P., Olszewski R., Gałązka-Świderek N., Targowski T., Skoczylas A., Majka K., Lejkowski W., Klasyfikacja szmerów oddechowych –badania pilotażowe, ELEKTRONIKA - KONSTRUKCJE, TECHNOLOGIE, ZASTOSOWANIA, ISSN: 0033-2089, DOI: 10.15199/13.2019.2.1, Vol.2, pp.4-12, 2019

Abstract:
Układ oddechowy pacjenta jest początkowo diagnozowany przy zastosowaniu stetoskopu. Osłuchowa interpretacja zjawisk fizycznych jest skomplikowana i wymaga od lekarza doświadczenia oraz predyspozycji. W niniejszym artykule zaprezentowano system pomiarowy i oprogramowanie badawcze, a także proces generacji cech dystynktywnych szmerów oddechowych różnicujących przypadki chorobowe od zdrowych. Wybrane reprezentacje stanowią obiecującą podstawę do opracowania systemu klasyfikującego wspierającego proces diagnostyczny

Keywords:
szmery oddechowe, klasyfikacja, cyfrowe przetwarzanie sygnałów

31.Billing U., Jetka T., Nortmann L., Wundrack N., Komorowski M., Waldherr S., Schaper F., Dittrich A., Robustness and Information Transfer within IL-6-induced JAK/STAT Signalling, Communications Biology, ISSN: 2399-3642, DOI: 10.1038/s42003-018-0259-4, Vol.2, No.27, pp.1-14, 2019
Billing U., Jetka T., Nortmann L., Wundrack N., Komorowski M., Waldherr S., Schaper F., Dittrich A., Robustness and Information Transfer within IL-6-induced JAK/STAT Signalling, Communications Biology, ISSN: 2399-3642, DOI: 10.1038/s42003-018-0259-4, Vol.2, No.27, pp.1-14, 2019

Abstract:
Cellular communication via intracellular signalling pathways is crucial. Expression and activation of signalling proteins is heterogenous between isogenic cells of the same cell-type. However, mechanisms evolved to enable sufficient communication and to ensure cellular functions. We use information theory to clarify mechanisms facilitating IL-6-induced JAK/STAT signalling despite cell-to-cell variability. We show that different mechanisms enabling robustness against variability complement each other. Early STAT3 activation is robust as long as cytokine concentrations are low. Robustness at high cytokine concentrations is ensured by high STAT3 expression or serine phosphorylation. Later the feedback-inhibitor SOCS3 increases robustness. Channel Capacity of JAK/STAT signalling is limited by cell-to-cell variability in STAT3 expression and is affected by the same mechanisms governing robustness. Increasing STAT3 amount increases Channel Capacity and robustness, whereas increasing STAT3 tyrosine phosphorylation reduces robustness but increases Channel Capacity. In summary, we elucidate mechanisms preventing dysregulated signalling by enabling reliable JAK/STAT signalling despite cell-to-cell heterogeneity.

32.Komorowski M., Tawfik D.S., The Limited Information Capacity of Cross-Reactive Sensors Drives the Evolutionary Expansion of Signaling, Cell Systems, ISSN: 2405-4712, DOI: 10.1016/j.cels.2018.12.006, Vol.8, No.1, pp.76-85.e6, 2019
Komorowski M., Tawfik D.S., The Limited Information Capacity of Cross-Reactive Sensors Drives the Evolutionary Expansion of Signaling, Cell Systems, ISSN: 2405-4712, DOI: 10.1016/j.cels.2018.12.006, Vol.8, No.1, pp.76-85.e6, 2019

Abstract:
Signaling systems expand by duplications of various components, be it receptors or downstream effectors. However, whether and how duplicated components contribute to higher signaling capacity is unclear, especially because in most cases, their specificities overlap. Using information theory, we found that augmentation of capacity by an increase in the copy number is strongly limited by logarithmic diminishing returns. Moreover, counter to conventional biochemical wisdom, refinements of the response mechanism, e.g., by cooperativity or allostery, do not increase the overall signaling capacity. However, signaling capacity nearly doubles when a promiscuous, non-cognate ligand becomes explicitly recognized via duplication and partial divergence of signaling components. Our findings suggest that expansion of signaling components via duplication and enlistment of promiscuously acting cues is virtually the only accessible evolutionary strategy to achieve overall high-signaling capacity despite overlapping specificities and molecular noise. This mode of expansion also explains the highly cross-wired architecture of signaling pathways.

Keywords:
paralog expansion, gene duplication, allostery, cooperativity, biochemical signal processing, information capacity

33.Dobruch-Sobczak K.S., Piotrzkowska-Wróblewska H., Klimonda Z., Gumowska M.E., Litniewski J., Ultrasound echogenicity reveals the response of breast cancer to chemotherapy, ECR 2019, EUROPEAN CONGRESS OF RADIOLOGY, 2019-02-27/03-03, Wiedeń (AT), DOI: 10.26044/ecr2019/C-1007, pp.1-15, 2019
34.Poma Bernaola A., Guzman V.H., Li M.S., Theodorakis P.E., Mechanical and thermodynamic properties of Aβ42 , Aβ40 and α-synuclein fibrils from molecular-scale simulation, APS March Meeting 2019, American Physical Society March meeting, 2019-03-04/03-08, Boston (US), pp.2174, 2019
Poma Bernaola A., Guzman V.H., Li M.S., Theodorakis P.E., Mechanical and thermodynamic properties of Aβ42 , Aβ40 and α-synuclein fibrils from molecular-scale simulation, APS March Meeting 2019, American Physical Society March meeting, 2019-03-04/03-08, Boston (US), pp.2174, 2019

Abstract:
Atomic force microscopy (AFM) is a versatile tool to characterise the mechanical properties of biological systems. However, AFM deformations are tiny, which makes impossible the analysis of the mechanical response by experiment. Here, we have employed a simulation protocol to determine the elastic properties of several biopolymers (i.e. biological fibrils) . For these systems, the simulation approach is sufficient to provide reliable values for three different types of elastic deformation, i.e. tensile (YL), shear (S), and indentation (YT). Our results enable the comparison of the mechanical properties of these fibrils. In particular, we find a significant elastic anisotropy between axial and transverse directions for all systems. In addition, our methodology is sensitive to molecular packing of the fibrils . Interestingly, our results suggest a significant correlation between mechanical stability and aggregation propensity (rate) in amyloid systems, that is, the higher the mechanical stability the faster the fibril formation takes place.

Keywords:
β-amyloid, α-synuclein, nanoindentation, molecular dynamics, fibril, thermodynamics, nanomechanics, coarse graining

35.Trombley C.I., Ekiel-Jeżewska M.L., Stable configurations of charged sedimenting particles, PHYSICAL REVIEW LETTERS, ISSN: 0031-9007, DOI: 10.1103/PhysRevLett.121.254502, Vol.121, pp.254502-1-254502-6, 2018
Trombley C.I., Ekiel-Jeżewska M.L., Stable configurations of charged sedimenting particles, PHYSICAL REVIEW LETTERS, ISSN: 0031-9007, DOI: 10.1103/PhysRevLett.121.254502, Vol.121, pp.254502-1-254502-6, 2018

Abstract:
The qualitative behavior of charged particles in a vacuum is given by Earnshaw’s Theorem which states that there is no steady configuration of charged particles in a vacuum which is asymptotically stable to perturbations. In a viscous fluid, examples of stationary configurations of sedimenting uncharged particles are known, but they are unstable or neutrally stable - they are not attractors. In this paper, it is shown by example that two charged particles settling in a fluid may have a configuration which is asymptotically stable to perturbations, for a wide range of charges, radii and densities. The existence of such "bound states" is essential from a fundamental point of view and it can be significant for dilute charged particulate systems in various biological, medical and industrial contexts.

36.Brzózka K., Krajewski M., Szumiata T., Górka B., Gawroński M., Kaczor T., Lin W.S., Lin H.M., Phase Evolution of Iron Nanoparticles Subjected to Thermal Treatment, ACTA PHYSICA POLONICA A, ISSN: 0587-4246, DOI: 10.12693/APhysPolA.134.1015, Vol.134, No.5, pp.1015-1020, 2018
Brzózka K., Krajewski M., Szumiata T., Górka B., Gawroński M., Kaczor T., Lin W.S., Lin H.M., Phase Evolution of Iron Nanoparticles Subjected to Thermal Treatment, ACTA PHYSICA POLONICA A, ISSN: 0587-4246, DOI: 10.12693/APhysPolA.134.1015, Vol.134, No.5, pp.1015-1020, 2018

Abstract:
Magnetic nanoparticles based on iron or iron oxides represent an excellent nanomaterial in respect of their fundamental research as well as numerous applications. This work presents a Mössbauer study of the influence of thermal treatment on the structure and phase composition of iron nanoparticles fabricated via a simple reduction reaction. Identification of iron-containing phases has been carried out for the series of samples annealed at different temperatures ranging between 200 C and 800 C. Both crystalline and amorphous iron as well as variety of iron oxides have been detected. It has been proved that the nanoparticles annealed at 500 C show superparamagnetic behavior as a result of ultrafine sizes of crystallites of iron oxides that arise in the oxidation processes.

37.Lewandowski M., Walczak M., Witek B., Rozbicki J., Steifer T., A GPU-Based Portable Phased-Array System with Full-Matrix Capture, IUS 2018, IEEE International Ultrasonics Symposium, 2018-10-22/10-25, KOBE (JP), DOI: 10.1109/ULTSYM.2018.8579964, pp.1-3, 2018
Lewandowski M., Walczak M., Witek B., Rozbicki J., Steifer T., A GPU-Based Portable Phased-Array System with Full-Matrix Capture, IUS 2018, IEEE International Ultrasonics Symposium, 2018-10-22/10-25, KOBE (JP), DOI: 10.1109/ULTSYM.2018.8579964, pp.1-3, 2018

Abstract:
The widely adopted ultrasound Phased-Array (PA) systems for nondestructive testing (NDT) use standard beamforming for line-by-line image creation. The introduction of the new full-matrix capture (FMC) technique enables the implementation of advanced processing algorithms (e.g. the total focusing method, multi-pass adaptive techniques). However, the limited availability of portable PA systems with FMC capabilities prevents widespread introduction. Our goal was to demonstrate the feasibility of a portable PA solution with FMC and advanced processing with the help of a mobile GPU. Using an OEM ultrasound front-end module (us4us Ltd., Poland), we integrated a complete PA system with an embedded Nvidia Tegra X2 module. An external probe adapter enables a direct connection to commercial Olympus-NDT PA probes with up to 128-elements (32-element active RX aperture). The system is fully programmable, both in the front-end (TX/RX schemes, acquisition parameters), as well as in the digital signal processing chain. Raw RF data is acquired and transferred to mobile GPU memory for processing. The algorithm can be conveniently implemented using a standard Nvidia CUDA toolkit. We implemented real-time B-mode imaging with the total focusing method for demonstration purposes. The presented all-in-one system is a fully flexible tool for the research and evaluation of novel Phased-Array FMC methods and complex signal processing algorithms. An extended programmability and real-time access to raw channel data allows to create custom solutions specifically dedicated to any one NDT application. Mobile GPU parallel processing provides a strong enough performance for real-time imaging. Its small size and low-power consumption make the system an ideal candidate for a portable industrial flaw detector with advanced processing.

38.Kiełczyński P., Ptasznik S., Kalinowski A., Investigation of high-pressure thermophysical parameters of edible oils using ultrasonic methods, 26th International Scientific Conference Progress in Technology of Vegetable Fats, 2018-06-06/06-08, Smardzewice (PL), pp.31-32, 2018
Kiełczyński P., Ptasznik S., Kalinowski A., Investigation of high-pressure thermophysical parameters of edible oils using ultrasonic methods, 26th International Scientific Conference Progress in Technology of Vegetable Fats, 2018-06-06/06-08, Smardzewice (PL), pp.31-32, 2018

Abstract:
The presentation includes an overview of the ultrasonic methods used to investigate the thermophysical 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, Fourier transform infrared spectroscopy) is very difficult, practically impossible. The basic ultrasonic measurements are measurements of velocity and attenuation of the ultrasonic wave. A brief description of the properties and parameters describing ultrasonic waves will be presented. The most important thermophysical parameters of oils include: 1) adiabatic and isothermal compressibility; 2) thermal expansion coefficient; 3) specific heat at constant pressure 4) surface tension; 5) viscosity, 6) thermal pressure coefficient and 7) thermal conductivity. 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 (up to 800 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) were detected and investigated. Camelina sativa oil is a very promising raw material for the production of biofuels. It is practically impossible to investigate these high pressure phase transformations in edible oils using classical measurement methods. Application of ultrasonic measurement methods enables the investigation of the physicochemical properties of edible oils (liquids) under high pressure.

Keywords:
Thermophysical parameters, ultrasonic methods, edible oils, high-pressure

39.Konowrocki R., Motor current signature analysis for railway driving system condition monitoring, 26 Seminaire Franco-Polonais de Mecanique, 2018-05-14/05-15, Warszawa (PL), pp.50, 2018
Konowrocki R., Motor current signature analysis for railway driving system condition monitoring, 26 Seminaire Franco-Polonais de Mecanique, 2018-05-14/05-15, Warszawa (PL), pp.50, 2018

Abstract:
Drive systems are one of the key components in railway vehicles. The need of an easy and effective monitoring and diagnosis technique has led to the increasing use of motor current signature analysis. Wheelsets, bearing and toothed gear faults in the railway drive system run by an induction motor causes change in its stator current spectrum. The above-mentioned defects in the electric drives cause variations of load irregularities in the magnetic field which in turn change the mutual and self-inductance causing side bands across the line frequency. Results of this analysis presented in the paper are used in order to investigate the drive system’s sensitivity to torsional oscillations. Here, the dynamic electromechanical interaction between the electric driving motor and the rotating wheelset is considered. The main objective of this paper is shown influence such faults in the railway drive system on motor current signature. Fast Fourier Transform (FFT) is initially employed for a first comparison between a healthy and a defective system. In the next step, wavelet analysis is used. Base wavelet has been selected on the basis of wavelet selection criteria - Maximum Relative wavelet energy. Additional this investigation has proved that the torsional stiffness and damping of drivetrain system strongly affect amplitudes of the self-excited vibrations which effects on motor current signatures of induction motor. Conclusions drawn from the computational results can be very useful during a design phase of diagnostic and monitoring devices as well as helpful for their users during a regular operation and maintenance

Keywords:
drive system, condition monitoring, self-excited vibrations, railway vehicles, electromechanical interaction

40.Jarosik P., Byra M., Lewandowski M., Waveflow - Towards Integration of Ultrasound Processing with Deep Learning, IUS 2018, IEEE International Ultrasonics Symposium, 2018-10-22/10-25, KOBE (JP), pp.1-3, 2018
Jarosik P., Byra M., Lewandowski M., Waveflow - Towards Integration of Ultrasound Processing with Deep Learning, IUS 2018, IEEE International Ultrasonics Symposium, 2018-10-22/10-25, KOBE (JP), pp.1-3, 2018

Abstract:
The ultimate goal of this work is a real-time processing framework for ultrasound image reconstruction augmented with machine learning. To attain this, we have implemented WaveFlow – a set of ultrasound data acquisition and processing tools for TensorFlow. WaveFlow includes: ultrasound Environments (connection points between the input raw ultrasound data source and TensorFlow) and signal processing Operators (ops) library. Raw data can be processed in real-time using algorithms available both in TensorFlow and WaveFlow. Currently, WaveFlow provides ops for B-mode image econstruction (beamforming), signal processing and quantitative ultrasound. The ops were implemented both for the CPU and GPU, as well as for built-in automated tests and benchmarks. To demonstrate WaveFlow’s performance, ultrasound data were acquired from wire and cyst phantoms and elaborated using selected sequences of the ops. We implemented and valuated: Delay-and-Sum beamformer, synthetic transmit aperture imaging (STAI), planewave imaging (PWI), envelope detection algorithm and dynamic range clipping. The benchmarks were executed on the NVidiaR Titan X GPU integrated in the USPlatform research scanner (us4us Ltd., Poland). We achieved B-mode image reconstruction frame rates of 55 fps, 17 fps for the STAI and the PWI algorithms, respectively. The results showed the feasibility of realtime ultrasound image reconstruction using WaveFlow operatorsin the TensorFlow framework. WaveFlow source code can be found at github.com/waveflow-team/waveflow.

41.Zembrzycki K., Kowalewski T.A., Pawłowska S., Chrzanowska-Giżyńska J., Nowak M., Walczak M., Pierini F., Atomic force microscopy combined with optical tweezers (AFM/OT): characterization of micro and nanomaterial interactions, SPIE Optics + Photonics, 2018-08-21/08-23, San Diego (US), No.10723, pp.1072323-1-6, 2018
Zembrzycki K., Kowalewski T.A., Pawłowska S., Chrzanowska-Giżyńska J., Nowak M., Walczak M., Pierini F., Atomic force microscopy combined with optical tweezers (AFM/OT): characterization of micro and nanomaterial interactions, SPIE Optics + Photonics, 2018-08-21/08-23, San Diego (US), No.10723, pp.1072323-1-6, 2018

Abstract:
Materials containing suspended micro- or nanomaterials are used extensively in multiple fields of research and industry. In order to understand the behavior of nanomaterials suspended in a liquid, the knowledge of particle stability and mobility is fundamental. For this reason, it is necessary to know the nanoscale solid-solid interaction and the hydrodynamic properties of the particles. In the presented research we used a hybrid Atomic Force Microscope coupled with Optical Tweezers system to measure the femtonewton scale interaction forces acting between single particles and the walls of a microchannel at different separation distances and environmental conditions. We show an important improvement in a typical detection system that increases the signal to noise ratio for more accurate position detection at very low separation distances.

Keywords:
Optical Tweezers, Atomic Force Microscopy, particle-wall interaction, colloid stability

42.Perzyna P., Thermodynamic Theory of Viscoplasticity, Advances in Applied Mechanics, ISSN: 0065-2156, DOI: 10.1016/S0065-2156(08)70345-4, Vol.11, pp.313-354, 1971
Perzyna P., Thermodynamic Theory of Viscoplasticity, Advances in Applied Mechanics, ISSN: 0065-2156, DOI: 10.1016/S0065-2156(08)70345-4, Vol.11, pp.313-354, 1971

Abstract:
This chapter reviews the thermodynamic foundations of the theory of viscoplasticity. The essential feature of viscoplasticity is the simultaneous description of rheologic and plastic effects of a material. The necessity for simultaneous consideration of viscoelastic and plastic properties of a material is indicated by the experimental investigations of dynamic loads. The thermodynamic theory of elastic-viscoplastic materials presents for finite strains two basic difficulties. The first of these is connected with the kinematic description of plastic deformation. The second difficulty concerns the problem of choice of thermodynamic variables of state. The chapter discusses development of the thermodynamic theory of plasticity for finite strains using the rate-type theory, and generalized the inviscid theory of plasticity to nonisothermal finite deformations. The principle of material frame indifference called “invariance requirements under superposed rigid body motions,” was used and explored the thermodynamical restrictions. The chapter presents the formulation of the thermodynamic theory of a rate-sensitive plastic material within the framework of thermodynamics of a material with internal state variables. In this thermodynamic theory of an inelastic material, the deformation tensor and temperature are considered as thermodynamic state variables, while the components of the inelastic deformation tensor appear as internal state parameters.