Instytut Podstawowych Problemów Techniki
Polskiej Akademii Nauk

Najnowsze publikacje

Publikacje odnotowane przez trzy miesiące

1. Magliulo M., Lengiewicz J., Zilian A., Beex L.A.A., Frictional interactions for non‐localised beam‐to‐beam and beam‐inside‐beam contact, INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, ISSN: 0029-5981, DOI: 10.1002/nme.6596, pp.1-43, 2021

Streszczenie:
This contribution presents the extensions of beam‐to‐beam and beam‐inside‐beam contact schemes of the same authors towards frictional interactions. Since the schemes are based on the beams' true surfaces (instead of surfaces implicitly deduced from the beams' centroid lines), the presented enhancements are not only able to account for frictional sliding in the beams' axial directions, but also in the circumferential directions. Both the frictional beam‐to‐beam approach as well as the frictional beam‐inside‐beam approach are applicable to shear‐deformable and shear‐undeformable beams, as well as to beams with both circular and elliptical cross‐sections (although the cross‐sections must be rigid). A penalty formulation is used to treat unilateral and frictional contact constraints. FE implementation details are discussed, where automatic differentiation techniques are used to derive the implementations. Simulations involving large sliding displacements and large deformations are presented for both beam‐to‐beam and beam‐inside‐beam schemes. All simulation results are compared to those of the frictionless schemes.

Słowa kluczowe:
beam contact, beam-to-beam contact, beam-inside-beam contact, friction, Coulomb's law

(200p.)
2. Tauzowski P., Błachowski B., Lógó J., Topology optimization of elasto-plastic structures under reliability constraints: a first order approach, COMPUTERS AND STRUCTURES, ISSN: 0045-7949, DOI: 10.1016/j.compstruc.2020.106406, Vol.243, pp.106406-1-15, 2021

Streszczenie:
The objective of this study is to propose a relatively simple and efficient method for reliability based topology optimization for structures made of elasto-plastic material. The process of determining the optimal topology of elasto-perfectly plastic structures is associated with the removal of material from the structure. Such a process leads to weakening of structural strength and stiffness causing at the same time increase the likelihood of structural failure. An important aspect of engineering design is to track this probability during the optimization process and not allow the structure safety to exceed a certain level specified by the designer. The purpose of this work is to combine the previously developed yield-limited topology optimization method with reliability analysis using first order approach. Effectiveness of the proposed methodology is demonstrated on benchmark problems proposed by Rozvany and Maute, and the elasto-plastic topology design of L-shape structure which is frequently used in different approaches for stress constrained topology optimization.

Słowa kluczowe:
topology optimization, reliability analysis, elasto-plastic analysis

(140p.)
3. Kopeć M., Kukla D., Brodecki A., Kowalewski Z.L., Effect of high temperature exposure on the fatigue damage development of X10CrMoVNb9-1 steel for power plant pipes, International Journal of Pressure Vessels and Piping, ISSN: 0308-0161, DOI: 10.1016/j.ijpvp.2020.104282, Vol.189, pp.104282-1-16, 2021

Streszczenie:
The aim of this research was to compare the effect of 80 000 h exploitation time in high temperature on mechanical properties and microstructure of X10CrMoVNb9-1 (P91) power engineering steel for pipes. The specimens obtained from two pipes: new, as-received and after exploitation were subjected to fatigue loadings to compare their mechanical responses. Additionally, the uniaxial tensile tests on both types of P91 steel were performed. The microstructure evolution before and after deformation was monitored using optical and scanning electron microscopy. The time intensive, high temperature exposure of P91 power engineering steel led to significant phase transformation and subsequent deterioration of mechanical properties and was further described as a function of the fatigue damage measure, φ, and the fatigue damage parameter D. Further proposed methodology of power exponent approximation of the fatigue damage measure, φ, and fatigue damage parameter D, allowed to successfully determine the fatigue life of P91 steel.

Słowa kluczowe:
fatigue development, damage, P91 steel, microstructure

(140p.)
4. Ceroni F., Darban H., Caterino N., Luciano R., Efficiency of injected anchors in masonry elements: evaluation of pull-out strength, CONSTRUCTION AND BUILDING MATERIALS, ISSN: 0950-0618, DOI: 10.1016/j.conbuildmat.2020.121707, Vol.267, pp.121707-1-121707-14, 2021

Streszczenie:
Injected anchors in masonry elements represent a widespread technique for improving the 'box behavior' of masonry structures, since they contribute to avoid or delay out-of-plane mechanisms under horizontal actions. Despite of their diffusion, no clear design indications for injected anchors are available in literature and codes. This paper is aimed to propose design formulations for the maximum pull-out force in injected anchors basing on wide numerical analyses realized through a 2D Finite Element (FE) model specifically tuned to simulate pull-out tests. Thanks to the variation of several parameters, the most significant ones influencing the maximum pull-out force are identified and introduced in the strength models and several coefficients are assessed through best fitting regression analyses carried out on the numerical results. Finally, based on a 'design by testing' approach, preliminar 5% percentile provisions for the maximum pull-out force are proposed too, and the reliability of the ‘design-oriented’ formulation is assessed by means of comparisons with experimental results of some pull-out tests available in literature.

Słowa kluczowe:
injected anchors, masonry pull-out force, bond, regression analysis, design formulations

(140p.)
5. Wieczorek K., Ranachowski P., Ranachowski Z., Papliński P., Ageing tests of samples of glass-epoxy core rods in composite insulators subjected to high direct current (DC) voltage in a thermal chamber, Energies, ISSN: 1996-1073, DOI: 10.3390/en13246724, Vol.13, No.24, pp.6724-1-13, 2021

Streszczenie:
In this article, we presented the results of the tests performed on three sets of samples of glass-reinforced epoxy (GRE) core rods used in alternating current (AC) composite insulators with silicone rubber housing. The objective of this examination was to test the aging resistance of the rod material when exposed to direct current (DC) high voltage. We hypothesized that the long-term effects of the electrostatic field on the GRE core rod material would lead to a gradual degradation of its mechanical properties caused by ionic current flow. Further, we hypothesized that reducing the mechanical strength of the GRE core rod would lead to the breakage of the insulator. The first group of samples was used for reference. The samples from the second group were subjected to a temperature of about 50 °C for 6000 h. The third group of samples were aged by temperature and DC high voltage for the same time. The samples were examined using the 3-point bending test, micro-hardness measurement and microscopic analysis. No recordable degradation effects were found. Long-term temperature impact and, above all, the combined action of temperature and DC high voltage did not reduce the mechanical parameters or change the microstructure of the GRE material.

Słowa kluczowe:
DC high voltage, composite insulator, glass-reinforced epoxy core, 3-point bending test, mechanical strength, micro-hardness

(140p.)
6. Hou J., Li C., Jankowski Ł., Shi Y., Su L., Yu S., Geng T., Damage identification of suspender cables by adding virtual supports with the substructure isolation method, STRUCTURAL CONTROL AND HEALTH MONITORING, ISSN: 1545-2255, DOI: 10.1002/stc.2677, pp.e2677-1-19, 2021

Streszczenie:
Damage of bridge cables is mainly manifested as the decrease in cable forces. These forces are affected by the boundary conditions, cable length, cable stiffness, and cable appendages, making it hard to identify the cable forces. Based on the substructure isolation method, this study proposes an approach for cable force identification to judge cable damage by adding virtual supports to each cable so that the cables share the same length and boundary conditions. The cable forces can then be identified according to the relationship between the natural frequency and cable forces. The basic concept is that the boundary sensors are transformed into virtual supports by a linear combination of the convolution of measured responses to achieve the zero boundary response. A finite element model of a suspension bridge was used to validate the proposed method in a simulation. When the virtual supports were added to the cables, the relationship between the cable forces and the natural frequency was almost linear, and the cable damage could be successfully identified with 5% noise. Finally, the effectiveness of the proposed method was verified experimentally, and the natural frequency of the isolated cable substructure was confirmed to be a highly sensitive damage indicator.

Słowa kluczowe:
cable damage, cable forces, natural frequency, structural health monitoring (SHM), substructure isolation method, virtual supports

(140p.)
7. Nalepka K., Skoczeń B., Ciepielowska M., Schmidt R., Tabin J., Schmidt E., Zwolińska-Faryj W., Chulist R., Phase transformation in 316L austenitic steel induced by fracture at cryogenic temperatures: experiment and modelling, Materials, ISSN: 1996-1944, DOI: 10.3390/ma14010127, Vol.14, No.1, pp.127-1-27, 2021

Streszczenie:
Investigations by electron backscatter diffraction (EBSD) and X-ray diffraction with the use of synchrotron radiation, as well as parallel extended finite element (XFEM) simulations, reveal the evolution of the 316L stainless steel microstructure in the vicinity of a macro-crack developing at the temperature of liquid helium (4.2 K). The fracture propagation induces a dynamic, highly localized phase transformation of face-centred cubic austenite into α' martensite with a body-centred cubic structure. Synchrotron studies show that the texture of the primary phase controls the transition process. The austenite grains, tending to the stable Brass orientation, generate three mechanisms of the phase transformation. EBSD studies reveal that the secondary phase particles match the ordered austenitic matrix. Hence, interphase boundaries with the Pitsch disorientation are most often formed and α’ martensite undergoes intensive twinning. The XFEM simulations, based on the experimentally determined kinetics of the phase transformation and on the relevant constitutive relationships, reveal that the macro-crack propagates mainly in the martensitic phase. Synchrotron and EBSD studies confirm the almost 100% content of the secondary phase at the fracture surface. Moreover, they indicate that the boundaries formed then are largely random. As a result, the primary beneficial role of martensite as reinforcing particles is eliminated.

Słowa kluczowe:
austenitic steel, cryogenic temperatures, fracture process, fcc-bcc phase transformation, synchrotron radiation, electron backscatter diffraction, XFEM simulation

(140p.)
8. Jain A., Ghosh M., Krajewski M., Kurungot S., Michalska M., Biomass-derived activated carbon material from native European deciduous trees as an inexpensive and sustainable energy material for supercapacitor application, Journal of Energy Storage, ISSN: 2352-152X, DOI: 10.1016/j.est.2020.102178, Vol.34, pp.102178-1-9, 2021

Streszczenie:
Activated carbons are one of the possible electrode materials for supercapacitors (SCs), which are widely used in commercial applications. Herein, we reported the synthesis of a novel activated carbon derived through a cavitation process from the mixture of native European deciduous trees, Birch, Fagaceae, and Carpinus betulus (commonly known as European hornbeam), which was employed as the electrode material in SC. From the morphological and structural characterization, we observed that the prepared sample is a desirable carbon with good porosity and high specific surface area of about 614 m^2 g^-1. The electrochemical properties of the synthesized material were evaluated with a three-electrode configuration in 1.0 M H2SO4 electrolyte. It was found that in device mode, the carbon material delivers a specific capacitance of 24 F g^-1 at 0.25 A g^-1 with excellent cycling stability of over 10000 consecutive charge/discharge cycles. Thus, our studies demonstrate the facile synthesis of biomass-derived carbon and its application as a versatile electrode material for SC applications.

Słowa kluczowe:
biomass, carbon material, deciduous trees, electrode material, supercapacitor

(100p.)
9. Konowrocki R., Kalinowski D., Szolc T., Marczewski A., Identification of safety hazards and operating conditions of the low-floor tram with independently rotating wheels with various drive control configurations, EKSPLOATACJA I NIEZAWODNOŚĆ - MAINTENANCE AND RELIABILITY, ISSN: 1507-2711, DOI: 10.17531/ein.2021.1.3, Vol.23, No.1, pp.21-33, 2021

Streszczenie:
The aim of the article is to develop a method for the analysis of tram dynamics related to safety during operation. To achieve this, a mathematical model of the vehicle represented by a multibody simulation MBS system is used. Models of tram with a classic and innovative drive, based on a system of independently rotating wheels on crank axles are analyzed. A new configuration of an innovative drive control of the considered vehicle with the use of braking of independent wheels is proposed. A new geometry of test track is presented. During numerical investigation the values of 'Y' leading forces of tram wheels with the considered innovative drive proved to be lower than in the corresponding vehicle with standard wheelsets. It has been demonstrated that the active control systems are of key importance and should be applied in such innovative tram drives.

Słowa kluczowe:
maintenance of safety, reliability of trams, derailment of tramcar, numerical tests, drive with independently rotating wheel

(100p.)
10. Darban H., Caporale A., Luciano R., Nonlocal layerwise formulation for bending of multilayered/functionally graded nanobeams featuring weak bonding, EUROPEAN JOURNAL OF MECHANICS A-SOLIDS, ISSN: 0997-7538, DOI: 10.1016/j.euromechsol.2020.104193, Vol.86, pp.104193-1-12, 2021

Streszczenie:
The size-dependent bending of perfectly/imperfectly bonded multilayered/stepwise functionally graded nanobeams, e.g. multiwalled carbon nanotubes with weak van der Waals forces, with any arbitrary numbers of layers, exhibiting different material, geometrical, and length-scale properties, is studied through a layerwise formulation of the stress-driven nonlocal theory of elasticity and the Bernoulli-Euler beam theory. The formulation is also valid for the continuously graded nanobeams, where the through-the-thickness material gradation with any arbitrary distribution is approximated in a stepwise manner through many layers. The size-dependency of each layer is accounted for through nonlocal constitutive relationships, which define the strains at each point as the output of integral convolutions in terms of the stresses in all the points of the layer and a kernel. Linear elastic uncoupled interfacial laws are implemented to model the mechanical response of the interfaces. The size-dependent system of equilibrium equations governing the deformations of the layers are derived and subjected to the variationally consistent edge boundary conditions and the constitutive boundary conditions associated with the stress-driven integral convolution. The formulation is applied to multilayered and sandwich nanobeams and the effects of the interfacial imperfections on the displacement fields and the interfacial displacement jumps are studied. It is found that the interfacial imperfections have greater impact on the field variables of multilayered nanobeams than that of the multilayered beams with the large-scale dimensions.

Słowa kluczowe:
layered nanobeam, discrete layer approach, size-effect, imperfect interface, nonlocal elasticity

(100p.)
11. Gawlicki M., Jankowski Ł., Trajectory identification for moving loads by multicriterial optimization, SENSORS, ISSN: 1424-8220, DOI: 10.3390/s21010304, Vol.21, No.1, pp.304-1-20, 2021

Streszczenie:
Moving load is a fundamental loading pattern for many civil engineering structures and machines. This paper proposes and experimentally verifies an approach for indirect identification of 2D trajectories of moving loads. In line with the "structure as a sensor" paradigm, the identification is performed indirectly, based on the measured mechanical response of the structure. However, trivial solutions that directly fit the mechanical response tend to be erratic due to measurement and modeling errors. To achieve physically meaningful results, these solutions need to be numerically regularized with respect to expected geometric characteristics of trajectories. This paper proposes a respective multicriterial optimization framework based on two groups of criteria of a very different nature: mechanical (to fit the measured response of the structure) and geometric (to account for the geometric regularity of typical trajectories). The state-of-the-art multiobjective genetic algorithm NSGA-II is used to find the Pareto front. The proposed approach is verified experimentally using a lab setup consisting of a plate instrumented with strain gauges and a line-follower robot. Three trajectories are tested, and in each case the determined Pareto front is found to properly balance between the mechanical response fit and the geometric regularity of the trajectory.

Słowa kluczowe:
structural health monitoring (SHM), moving load, trajectory identification, geometric regularity, multicriterial optimization, load identification, inverse problems, structural mechanics

(100p.)
12. Opiela K.C., Zieliński T.G., Dvorák T., Kúdela Jr S., Perforated closed-cell aluminium foam for acoustic absorption, APPLIED ACOUSTICS, ISSN: 0003-682X, DOI: 10.1016/j.apacoust.2020.107706, Vol.174, pp.107706-1-17, 2021

Streszczenie:
Closed-cell metal foams are lightweight and durable materials resistant to high temperature and harsh conditions, but due to their fully closed porosity they are poor airborne sound absorbers. In this paper a classic method of drilling is used for a nearly closed-cell aluminium foam to open its porous interior to the penetration of acoustic waves propagating in air, thereby increasing the wave energy dissipation inside the pores of the perforated medium. The aim is to investigate whether it is possible to effectively approximate wave propagation and attenuation in industrial perforated heterogeneous materials with originally closed porosity of irregular shape by means of their simplified microstructural representation based on computer tomography scans. The applied multi-scale modelling of sound absorption in foam samples is confronted with impedance tube measurements. Moreover, the collected numerical and experimental data is compared with the corresponding results obtained for perforated solid samples to demonstrate a great benefit coming from the presence of an initially closed porous structure in the foam.

Słowa kluczowe:
closed-cell metal foams, perforation, sound absorption, microstructure effects, dissipated powers

(100p.)
13. Kopeć M., Kukla D., Yuan X., Rejmer W., Kowalewski Z.L., Senderowski C., Aluminide thermal barrier coating for high temperature performance of MAR 247 nickel based superalloy, Coatings, ISSN: 2079-6412, DOI: 10.3390/coatings11010048, Vol.11, No.1, pp.48-1-12, 2021

Streszczenie:
In this paper, mechanical properties of the as-received and aluminide layer coated MAR 247 nickel based superalloy were examined through creep and fatigue tests. The aluminide layer of 20 µm was obtained through the chemical vapor deposition (CVD) process in the hydrogen protective atmosphere for 8 h at the temperature of 1040 °C and internal pressure of 150 mbar. A microstructure of the layer was characterized using the scanning electron microscopy (SEM) and X-ray Energy Dispersive Spectroscopy (EDS). It was found that aluminide coating improve the high temperature fatigue performance of MAR247 nickel based superalloy at 900 °C significantly. The coated MAR 247 nickel based superalloy was characterized by the stress amplitude response ranging from 350 MPa to 520 MPa, which is twice as large as that for the uncoated alloy.

Słowa kluczowe:
chemical vapor deposition, nickel alloys, aluminide coatings, high temperature fatigue, creep

(100p.)
14. Pręgowska A., Signal fluctuations and the information transmission rates in binary communication channels, Entropy, ISSN: 1099-4300, DOI: 10.3390/e23010092, Vol.23, No.1, pp.92-1-12, 2021

Streszczenie:
In the nervous system, information is conveyed by sequence of action potentials, called spikes-trains. As MacKay and McCulloch suggested, spike-trains can be represented as bits sequences coming from Information Sources (IS). Previously, we studied relations between spikes' Information Transmission Rates (ITR) and their correlations, and frequencies. Now, I concentrate on the problem of how spikes fluctuations affect ITR. The IS are typically modeled as stationary stochastic processes, which I consider here as two-state Markov processes. As a spike-trains' fluctuation measure, I assume the standard deviation σ, which measures the average fluctuation of spikes around the average spike frequency. I found that the character of ITR and signal fluctuations relation strongly depends on the parameter s being a sum of transitions probabilities from a no spike state to spike state. The estimate of the Information Transmission Rate was found by expressions depending on the values of signal fluctuations and parameter s. It turned out that for smaller s<1, the quotient ITR/σ has a maximum and can tend to zero depending on transition probabilities, while for 1

Słowa kluczowe:
information source, information transmission rate, fluctuations, Shannon entropy, spike-trains, standard deviation

(100p.)
15. Golasiński K.M., Detsch R., Szklarska M., Łosiewicz B., Zubko M., Mackiewicz S., Pieczyska E.A., Boccaccini A.R., Evaluation of mechanical properties, in vitro corrosion resistance and biocompatibility of Gum Metal in the context of implant applications, Journal of the Mechanical Behavior of Biomedical Materials, ISSN: 1751-6161, DOI: 10.1016/j.jmbbm.2020.104289, Vol.115, pp.104289-1-11, 2021

Streszczenie:
In recent decades, several novel Ti alloys have been developed in order to produce improved alternatives to the conventional alloys used in the biomedical industry such as commercially pure titanium or dual phase (alpha and beta) Ti alloys. Gum Metal with the non-toxic composition Ti–36Nb–2Ta–3Zr–0.3O (wt. %) is a relatively new alloy which belongs to the group of metastable beta Ti alloys. In this work, Gum Metal has been assessed in terms of its mechanical properties, corrosion resistance and cell culture response. The performance of Gum Metal was contrasted with that of Ti–6Al–4V ELI (extra-low interstitial) which is commonly used as a material for implants. The advantageous mechanical characteristics of Gum Metal, e.g. a relatively low Young's modulus (below 70 GPa), high strength (over 1000 MPa) and a large range of reversible deformation, that are important in the context of potential implant applications, were confirmed. Moreover, the results of short- and long-term electrochemical characterization of Gum Metal showed high corrosion resistance in Ringer's solution with varied pH. The corrosion resistance of Gum Metal was best in a weak acid environment. Potentiodynamic polarization studies revealed that Gum Metal is significantly less susceptible to pitting corrosion compared to Ti–6Al–4V ELI. The oxide layer on the Gum Metal surface was stable up to 8.5 V. Prior to cell culture, the surface conditions of the samples, such as nanohardness, roughness and chemical composition, were analyzed. Evaluation of the in vitro biocompatibility of the alloys was performed by cell attachment and spreading analysis after incubation for 48 h. Increased in vitro MC3T3-E1 osteoblast viability and proliferation on the Gum Metal samples was observed. Gum Metal presented excellent properties making it a suitable candidate for biomedical applications.

Słowa kluczowe:
Gum Metal, mechanical behavior, in vitro corrosion resistance, in vitro biocompatibility, implant applications

(100p.)
16. Janczewska M., Szkop M., Pikus G., Kopyra K., Świątkowska A., Brygoła K., Karczmarczyk U., Walczak J., Żuk M.T., Duszak J., Ciach T., PSMA targeted conjugates based on dextran, Applied Radiation and Isotopes, ISSN: 0969-8043, DOI: 10.1016/j.apradiso.2020.109439, Vol.167, pp.109439-1-9, 2021

Streszczenie:
Background: Currently, radiotherapy is one of the most popular choices in clinical practice for the treatment of cancers. While it offers a fantastic means to selectively kill cancer cells, it can come with a host of side effects. To minimize such side effects, and maximize the therapeutic effect of the treatment, we propose the use of targeted radiopharmaceuticals. In the study presented herein, we investigate two synthetic pathways of dextran-based radiocarriers and provide their key chemical and physical properties: stability of the bonding of chelating agent and tertiary structure of obtained formulations and its influence on biological properties. Additionally, PSMA small molecule inhibitor was attached and quantified using DELFIA fluorescence assay. Finally, biological properties and radiolabeling yield were studied using confocal microscopy and ITLC-SG chromatography. Results: Two types of Dex-conjugates - micelle-like nanoparticles (NPs) and non-folded conjugates - were successfully generated and shown to exhibit cellular effects. The tertiary structure of the conjugates was found to influence the selectivity of PSMA and mediate cell binding as well as cellular uptake mechanisms. NPs were shown to be internalized by other, non - PSMA mediated channels. Simultaneously, the uptake of non-folded conjugates required PSMA inhibitor to pass through cell membrane. The radiochemical yield of NHS coupled DOTA chelator was between 91.3 and 97.7% while the TCT-amine bonding showed higher stability and gave the yields of 99.8-100%. Conclusions: We obtained novel, dextran-based radioconjugates, and presented a superior method of chelator binding, resulting in exquisite radiochemical properties as well as selective cross-membrane transport.

Słowa kluczowe:
dextran, radioconjugates, nanoparticles, prostate cancer, DOTA-conjugates

(70p.)
17. Lanzi M., Pierini F., Efficient and thermally stable BHJ solar cells based on a soluble hydroxy-functionalized regioregular polydodecylthiophene, REACTIVE AND FUNCTIONAL POLYMERS, ISSN: 1381-5148, DOI: 10.1016/j.reactfunctpolym.2020.104803, Vol.158, pp.104803-1-12, 2021

Streszczenie:
A new regioregular polythiophene derivative, called poly[3-(12-hydroxydodecyl)thiophene] (PT12OH), was synthesized by post-functionalizing its ω-brominated precursor poly[3-(12-bromododecyl)thiophene] (PT12Br) prepared using the Grignard metathesis route. Thanks to the optimal balance between hydrophilic and hydrophobic groups within its structure, PT12OH was highly soluble and easily filmable from common organic solvents allowing for its complete characterization. It also showed enhanced thermal properties, crystallinity, and self-assembling capabilities by the formation of strong inter- and intrachain hydrogen bonds. Bulk heterojunction photovoltaic cells with PT12OH and PC61BM showed a PCE of 4.83% and a remarkable over-time stability, offering good photoconversion efficiency even after 120 h of accelerated aging. Indeed, the PCE decrease was 34% for the hydroxylated polymer and 65% for its brominated precursor. It should also be pointed out that the enhanced thermal stability of PT12OH was achieved without resorting to any complex post-annealing photochemical, thermal, or chemical treatment and was thus directly ascribable to the polymer chemical structure. The simple and effective synthetic procedure, photovoltaic efficiency, and enhanced stability revealed the potential of PT12OH for large-scale organic solar cell applications.

Słowa kluczowe:
bulk heterojunction solar cell, regioregular polythiophene derivatives, post-polymerization functionalization, over-time stability

(70p.)
18. Błachowski B., Świercz A., Ostrowski M., Tauzowski P., Jankowski Ł., Multi-type sensor placement for structural health monitoring of tied-arch bridges, EWSHM 2020, 10th European Workshop on Structural Health Monitoring, 2020-07-04/07-07, Palermo (IT), DOI: 10.1007/978-3-030-64594-6_29, Vol.127, pp.286-297, 2021

Streszczenie:
Performance of any Structural Health Monitoring (SHM) system strongly depends on a set of sensors which are distributed over the structure under investigation. Optimal deployment of sensors on large scale structures such as tied-arch bridges is quite a challenging problem. Moreover, deployment of a sensor network consisting of different types of sensors (accelerometers, inclinometers or strain gauges) over a large scale bridge renders the task of optimization even more demanding. In the present study, a conventional sensor placement method for distribution of a homogenous sensor network is expanded to the heterogeneous case. First, the basic equations governing the estimation error will be recalled. Then, the Fisher information matrix is assembled using normalized translational and rotational mode shapes. Finally, a computational procedure is proposed which allows optimal sensor positions to be selected among thousands candidate locations. The effectiveness of the proposed strategy is demonstrated using a realistic example of a tied-arch bridge located in Poland.

Słowa kluczowe:
optimal sensor placement, structural health monitoring, tied-arch bridges, multi-type sensor network

19. Nakielski P., Pawłowska S., Rinoldi C., Ziai Y., De Sio L., Urbanek O., Zembrzycki K., Pruchniewski M., Lanzi M., Salatelli E., Calogero A., Kowalewski T.A., Yarin A.L., Pierini F., Multifunctional platform based on electrospun nanofibers and plasmonic hydrogel: a smart nanostructured pillow for near-Infrared light-driven biomedical applications, ACS Applied Materials and Interfaces, ISSN: 1944-8244, DOI: 10.1021/acsami.0c13266, Vol.12, No.49, pp.54328-54342, 2020

Streszczenie:
Multifunctional nanomaterials with the ability torespond to near-infrared (NIR) light stimulation are vital for thedevelopment of highly efficient biomedical nanoplatforms with apolytherapeutic approach. Inspired by the mesoglea structure ofjellyfish bells, a biomimetic multifunctional nanostructured pillowwith fast photothermal responsiveness for NIR light-controlled on-demand drug delivery is developed. We fabricate a nanoplatformwith several hierarchical levels designed to generate a series ofcontrolled, rapid, and reversible cascade-like structural changesupon NIR light irradiation. The mechanical contraction of thenanostructured platform, resulting from the increase of temper-ature to 42°C due to plasmonic hydrogel−light interaction, causesa rapid expulsion of water from the inner structure, passing through an electrospun membrane anchored onto the hydrogel core. Themutual effects of the rise in temperature and waterflow stimulate the release of molecules from the nanofibers. To expand thepotential applications of the biomimetic platform, the photothermal responsiveness to reach the typical temperature level forperforming photothermal therapy (PTT) is designed. The on-demand drug model penetration into pig tissue demonstrates theefficiency of the nanostructured platform in the rapid and controlled release of molecules, while the high biocompatibility confirmsthe pillow potential for biomedical applications based on the NIR light-driven multitherapy strategy.

Słowa kluczowe:
bioinspired materials, NIR-light responsive nanomaterials, multifunctional platforms, electrospun nanofibers, plasmonic hydrogel, photothermal-based polytherapy, on-demand drug delivery

(200p.)
20. Majkut M., Kwiecińska-Piróg J., Wszelaczyńska E., Pobereżny J., Gospodarek-Komkowska E., Wojtacki K., Barczak T., Antimicrobial activity of heat-treated Polish honeys, Food Chemistry, ISSN: 0308-8146, DOI: 10.1016/j.foodchem.2020.128561, pp.1-6, 2020

Streszczenie:
Bactericidal properties of honey depend on botanical and geographical origin, where thermal treatment can have a significant affect. The aim of this study was to investigate the effect of temperature on minimum bactericidal concentration (MBC), vitamin C content, total polyphenols content and antioxidant capacity of ferric reducing antioxidant potential (FRAP) of several nectar honey varieties from northern Poland (lime, rapeseed, multifloral and buckwheat). The honeys were subjected to thermal treatment at 22 °C, 42 °C, 62 °C, 82 °C and 100 °C for two exposure times. The results showed a significant reduction of antimicrobial properties (MBC 50%) at 82 °C and 62 °C after 15 and 120 min exposure time for most samples. Short time exposure reduced vitamin C content (50 %) but increased total polyphenols content (27%) and FRAP value (106%).

Słowa kluczowe:
honey, vitamin C, polyphenols, antioxidant properties, antibacterial activity, temperature treatment

(200p.)
21. Jaskulski R., Jóźwiak-Niedźwiedzka D., Yakymechko Y., Calcined Clay as Supplementary Cementitious Material, Materials, ISSN: 1996-1944, DOI: 10.3390/ma13214734, Vol.13, No.21, pp.4734-1-36, 2020

Streszczenie:
Calcined clays are the only potential materials available in large quantities to meet the requirements of eco-efficient cement-based materials by reducing the clinker content in blended cements or reducing the cement content in concrete. More than 200 recent research papers on the idea of replacing Portland cement with large amounts of calcined clay are presented and discussed in detail. First, the fundamental information about the properties and structure of clay minerals is described. Then, the process of activation and hydration of clays is discussed, including the methods of pozzolanic activity assessment. Additionally, various testing methods of clays from different worldwide deposits are presented. The application of calcined clay in cement and concrete technology is then introduced. A separate chapter is devoted to lime calcined clay cement. Then an influence of calcined clay on durability of concrete is summarized. Finally, conclusions are formulated.

Słowa kluczowe:
calcined clay, binder, supplementary cementitious materials, cement-based materials

(140p.)
22. Rutecka A., Kursa M., Pietrzak K., Kowalczyk-Gajewska K., Makowska K., Wyszkowski M., Damage evolution in AA2124/SiC metal matrix composites under tension with consecutive unloadings, ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING, ISSN: 1644-9665, DOI: 10.1007/s43452-020-00134-x, Vol.20, No.4, pp.135-1-18, 2020

Streszczenie:
Nonlinear properties of metal matrix composites (MMCs) are studied. The research combines results of loading-unloading tensile tests, microstructural observations and numerical predictions by means of micromechanical mean-field models. AA2124/SiC metal matrix composites with SiC particles, produced by the Aerospace Metal Composites Ltd. (AMC) are investigated. The aluminum matrix is reinforced with 17% and 25% of SiC particles. The best conditions to evaluate the current elastic stiffness modulus have been assessed. Tensile tests were carried out with consecutive unloading loops to obtain actual tensile modulus and study degradation of elastic properties of the composites. The microstructure examination by scanning electron microscopy (SEM) showed a variety of phenomena occurring during composite deformation and possible sources of elastic stiffness reduction and damage evolution have been indicated. Two micromechanical approaches, the incremental Mori–Tanaka (MT) and self-consistent (SC) schemes, are applied to estimate effective properties of the composites. The standard formulations are extended to take into account elasto-plasticity and damage development in the metal phase. The method of direct linearization performed for the tangent or secant stiffness moduli is formulated. Predictions of both approaches are compared with experimental results of tensile tests in the elastic–plastic regime. The question is addressed how to perform the micromechanical modelling if the actual stress–strain curve of metal matrix is unknown.

Słowa kluczowe:
metal matrix composites, tension with unloadings, damage, microstructure, non-linear effective properties

(140p.)
23. Rezaee Hajidehi M., Stupkiewicz S., Modelling of propagating instabilities in pseudoelastic NiTi tubes under combined tension–torsion: helical bands and apparent yield locus, INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, ISSN: 0020-7683, DOI: 10.1016/j.ijsolstr.2020.09.011, pp.1-20, 2020

Streszczenie:
This paper is concerned with modelling of propagating instabilities and transformation patterns in NiTi tubes subjected to combined tension–torsion loading. A recently developed gradient-enhanced finite-strain model of pseudoelasticity is employed for this purpose, and respective finite-element computations are carried out. It is shown that the model is capable of representing a number of experimentally observed effects. The major effect, which has not been successfully modelled to date, is that the transformation is inhomogeneous under tension-dominated loading and alters towards a homogeneous transformation as the level of torsion is increased. To capture this effect, the model must deliver a non-monotonic (up-down-up) stress–strain response in tension and a monotonic one in torsion, and this can be achieved if the model includes three features: tension–compression asymmetry, transverse isotropy of the transformation strain, and deformation-dependent hardening/softening response. A detailed study is also carried out regarding the transformation yield locus. The results reveal an ambiguity in determination of the yield locus for tension-dominated loading and hence an ambiguity in determination of the tension–compression asymmetry. This aspect seems to have been overlooked in the literature despite its impact on correct interpretation of experimental results.

Słowa kluczowe:
shape memory alloys, phase transformation, strain localization, finite-element method

(140p.)
24. Stupkiewicz S., Rezaee-Hajidehi M., Petryk H., Multiscale analysis of the effect of interfacial energy on non-monotonic stress–strain response in shape memory alloys, INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, ISSN: 0020-7683, DOI: 10.1016/j.ijsolstr.2020.04.006, pp.1-15, 2020

Streszczenie:
The effect of formation and evolution of stress-induced martensitic microstructures on macroscopic mechanical properties of shape memory alloys in the pseudoelastic regime is investigated with account for size-dependent energy of interfaces. A quantitative relationship is established between the changes in free energy and dissipation on the interfaces at three microstructural scales and the overall mechanical characteristic of the material under tensile loading. The multiscale analysis carried out for a polycrystalline NiTi shape memory alloy has revealed that the interfacial energy storage and dissipation can strongly affect the shape and width of the stress–strain hysteresis loop. The predicted non-monotonic stress–strain response for the material of a selected grain size shows a remarkable similarity to the experimental one extracted from a tensile test of a laminate by Hallai and Kyriakides (2013). By the classical Maxwell construction, the non-monotonic response for a material element results in a commonly observed stress plateau for a tensile specimen, which is associated with the propagation of phase transformation fronts. This behaviour is confirmed with striking accuracy by 3D finite-element computations performed for a macroscopic tensile specimen, in which propagating instability bands are treated explicitly.

Słowa kluczowe:
microstructures, martensitic transformation, size effects, incremental energy minimization, propagating instabilities

(140p.)
25. Walczak J., Malińska D., Drabik K., Michalska B., Prill M., Johne S., Luettich K., Szymański J., Peitsch M.C., Hoeng J., Duszyński J., Więckowski M.R., van der Toorn M., Szczepanowska J., Mitochondrial network and biogenesis in response to short and long-term exposure of human BEAS-2B cells to aerosol extracts from the tobacco heating system 2.2, Cellular Physiology and Biochemistry, ISSN: 1015-8987, DOI: 10.33594/000000216, Vol.54, No.2, pp.230-251, 2020

Streszczenie:
Background/aims: Adverse effects of cigarette smoke on health are widely known. Heating rather than combusting tobacco is one of strategies to reduce the formation of toxicants. The sensitive nature of mitochondrial dynamics makes the mitochondria an early indicator of cellular stress. For this reason, we studied the morphology and dynamics of the mitochondrial network in human bronchial epithelial cells (BEAS-2B) exposed to total particulate matter (TPM) generated from 3R4F reference cigarette smoke and from aerosol from a new candidate modified risk tobacco product, the Tobacco Heating System (THS 2.2). Methods: Cells were subjected to short (1 week) and chronic (12 weeks) exposure to a low (7.5 µg/mL) concentration of 3R4F TPM and low (7.5 µg/mL), medium (37.5 µg/mL), and high (150 µg/mL) concentrations of TPM from THS 2.2. Confocal microscopy was applied to assess cellular and mitochondrial morphology. Cytosolic Ca2+ levels, mitochondrial membrane potential and mitochondrial mass were measured with appropriate fluorescent probes on laser scanning cytometer. The levels of proteins regulating mitochondrial dynamics and biogenesis were determined by Western blot. Results: In BEAS-2B cells exposed for one week to the low concentration of 3R4F TPM and the high concentration of THS 2.2 TPM we observed clear changes in cell morphology, mitochondrial network fragmentation, altered levels of mitochondrial fusion and fission proteins and decreased biogenesis markers. Also cellular proliferation was slowed down. Upon chronic exposure (12 weeks) many parameters were affected in the opposite way comparing to short exposure. We observed strong increase of NRF2 protein level, reorganization of mitochondrial network and activation of the mitochondrial biogenesis process. Conclusion: Comparison of the effects of TPMs from 3R4F and from THS 2.2 revealed, that similar extent of alterations in mitochondrial dynamics and biogenesis is observed at 7.5 µg/mL of 3R4F TPM and 150 µg/mL of THS 2.2 TPM. 7 days exposure to the investigated components of cigarette smoke evoke mitochondrial stress, while upon chronic, 12 weeks exposure the hallmarks of cellular adaptation to the stressor were visible. The results also suggest that mitochondrial stress signaling is involved in the process of cellular adaptation under conditions of chronic stress caused by 3R4F and high concentration of THS 2.2.

Słowa kluczowe:
BEAS-2B cells, candidate modified risk tobacco product, cigarette smoke, mitochondrial dynamics, tobacco heating system 2.2.

(140p.)
26. Zdioruk M., Want A., Mietelska-Porowska A., Laskowska-Kaszub K., Wojsiat J., Klejman A., Użarowska E., Koza P., Olejniczak S., Pikul S., Konopka W., Golab J., Wojda U., A new inhibitor of tubulin polymerization kills multiple cancer cell types and reveals p21-mediated mechanism determining cell death after mitotic catastrophe, Cancers, ISSN: 2072-6694, DOI: 10.3390/cancers12082161, Vol.12, No.8, pp.2161-1-21, 2020

Streszczenie:
Induction of mitotic catastrophe through the disruption of microtubules is an established target in cancer therapy. However, the molecular mechanisms determining the mitotic catastrophe and the following apoptotic or non-apoptotic cell death remain poorly understood. Moreover, many existing drugs targeting tubulin, such as vincristine, have reduced efficacy, resulting from poor solubility in physiological conditions. Here, we introduce a novel small molecule 2-aminoimidazoline derivative-OAT-449, a synthetic water-soluble tubulin inhibitor. OAT-449 in a concentration range from 6 to 30 nM causes cell death of eight different cancer cell lines in vitro, and significantly inhibits tumor development in such xenograft models as HT-29 (colorectal adenocarcinoma) and SK-N-MC (neuroepithelioma) in vivo. Mechanistic studies showed that OAT-449, like vincristine, inhibited tubulin polymerization and induced profound multi-nucleation and mitotic catastrophe in cancer cells. HeLa and HT-29 cells within 24 h of treatment arrested in G2/M cell cycle phase, presenting mitotic catastrophe features, and 24 h later died by non-apoptotic cell death. In HT-29 cells, both agents altered phosphorylation status of Cdk1 and of spindle assembly checkpoint proteins NuMa and Aurora B, while G2/M arrest and apoptosis blocking was consistent with p53-independent accumulation in the nucleus and largely in the cytoplasm of p21/waf1/cip1, a key determinant of cell fate programs. This is the first common mechanism for the two microtubule-dissociating agents, vincristine and OAT-449, determining the cell death pathway following mitotic catastrophe demonstrated in HT-29 cells.

Słowa kluczowe:
cancer, chemotherapeutic, microtubule-poison, vincristine, mitotic catastrophe, non-apoptotic cell death, p21, p53

(140p.)
27. Szymczak T., Makowska K., Kowalewski Z.L., Characteristics and fracture of the S700MC high strength steel under various types of loading, Materials, ISSN: 1996-1944, DOI: 10.3390/ma13225249, Vol.13, No.22, pp.5249-1-17, 2020

Streszczenie:
This paper focuses on the mechanical properties analysis of the high strength S700MC steel applied in welding joints. The research comprised mechanical tests for checking what the changes of tensile characteristics, mechanical parameters, resistance to impact, and fracture toughness look like in selected regions of the welding joint. Stress-strain curves have shown significant differences in the tensile characteristic shape and the values of Young's modulus, yield stress, ultimate tensile strength, and ductility due to the welding process applied. In the case of Charpy tests, the courses of the accumulated energy, force, deflection, and project velocity are presented, indicating the maximum value of absorbed energy, the same level of force during the first contact of the projectile with the specimens, and the significant variation of the velocity for the impact energy ranging from 50 J up to 300 J. On the basis of the fracture toughness tests, the distributions of the CTOD (Crack Tip Opening Displacement) values are presented for the parent material, HAZ (Heat Affected Zone) and weld. Moreover, the characteristic features of the fatigue pre-crack, transient and crack propagation zones are identified and discussed.

Słowa kluczowe:
high strength steel, weld, HAZ, tensile curve, impact, fracture toughness, CTOD, fractography, S700MC

(140p.)
28. Moreira R., Vargas Guzman H., Boopathi S., Baker J.L., Poma Bernaola A., Characterization of structural and energetic differences between conformations of the SARS-CoV-2 spike protein, Materials, ISSN: 1996-1944, DOI: 10.3390/ma13235362, Vol.13, No.23, pp.5362-1-14, 2020

Streszczenie:
The novel coronavirus disease 2019 (COVID-19) pandemic has disrupted modern societies and their economies. The resurgence in COVID-19 cases as part of the second wave is observed across Europe and the Americas. The scientific response has enabled a complete structural characterization of the Severe Acute Respiratory Syndrome—novel Coronavirus 2 (SARS-CoV-2). Among the most relevant proteins required by the novel coronavirus to facilitate the cell entry mechanism is the spike protein. This protein possesses a receptor-binding domain (RBD) that binds the cellular angiotensin-converting enzyme 2 (ACE2) and then triggers the fusion of viral and host cell membranes. In this regard, a comprehensive characterization of the structural stability of the spike protein is a crucial step to find new therapeutics to interrupt the process of recognition. On the other hand, it has been suggested that the participation of more than one RBD is a possible mechanism to enhance cell entry. Here, we discuss the protein structural stability based on the computational determination of the dynamic contact map and the energetic difference of the spike protein conformations via the mapping of the hydration free energy by the Poisson–Boltzmann method. We expect our result to foster the discussion of the number of RBD involved during recognition and the repurposing of new drugs to disable the recognition by discovering new hotspots for drug targets apart from the flexible loop in the RBD that binds the ACE2.

Słowa kluczowe:
COVID-19, SARS-CoV-2, spike protein, RBD, structural stability, large conformational changes, protein complexes, free energy, molecular dynamics, dynamics contact analysis

(140p.)
29. Wahlen C., Blankenburg J., Tiedemann P., Ewald J., Sajkiewicz P., Müller A.H.E., Floudas G., Frey H., Tapered multiblock copolymers based on farnesene and styrene: impact of biobased polydiene architectures on material properties, Macromolecules, ISSN: 0024-9297, DOI: 10.1021/acs.macromol.0c02118, pp.1-12, 2020

Streszczenie:
The reactivity of the biobased monomer β-farnesene in the statistical anionic copolymerization with styrene and the effect of the bottlebrush-like polyfarnesene structure on the phase separation behavior were investigated. Furthermore, thermal and material properties of β-farnesene-based thermoplastic elastomers, based on tri- and pentablock copolymers with styrene, and their processing behavior were investigated. As shown by H NMR online kinetics, in analogy to both isoprene and β-myrcene, the direct (i.e., statistical) anionic copolymerization of β-farnesene and styrene in cyclohexane affords block-like, tapered copolymers because of the highly diverging reactivity ratios (rFar = 27; rS = 0.037). Algebraic expressions for both the molar and volume composition profiles were derived, which provide a mathematically accurate picture of the tapered copolymer structure. The one-pot, tapered copolymer approach was used to synthesize series of tri- (ABA) and pentablock (ABABA) copolymers of styrene (A) and β-farnesene (B), varying the polydiene volume fraction between 0.50 and 0.68, respectively. Depending on the polydiene volume fraction, the tapered multiblock copolymers showed phase separation in lamellar or hexagonally packed cylindrical structures, as determined by small-angle X-ray scattering. Well-defined tapered tri- and pentablock copolymers with molecular weights of 120 kg mol^–1 and low dispersity (Đ = 1.05–1.16) were obtained. The order of the tapered poly(farnesene-co-styrene) copolymers bears many similarities (same morphology, practically the same domain spacing, and a similar degree of segregation) to the corresponding polyisoprene copolymers with the same polydiene volume fraction. The similar domain spacing is suggestive of looped configurations mainly in the polyisoprene copolymers that are reduced in the polyterpene copolymers. The influence of the long alkenyl side chains of the polyfarnesene middle blocks on the mechanical properties of the multiblock copolymers was investigated by tensile testing. For this purpose, the respective tri- and pentablock copolymers of isoprene (C5 unit) and β-myrcene (C10) with styrene were synthesized as well, containing equal polydiene volume fractions as their β-farnesene-based (C15) analogs. The mechanical toughness of the polymers increased with decreasing length of the alkenyl side chains (from β-farnesene to isoprene). Furthermore, tapered polyfarnesene tri- and pentablock copolymers with styrene exhibit reduced solution viscosity in comparison to, for example, polyisoprene-based tapered PS-b-P(I-co-S) triblock copolymers, resulting in improved processability by electrospinning. These properties are discussed in terms of the different configurations of the polyterpene blocks and the pronounced differences of the entanglement molecular weights.

(140p.)
30. De Sio L., Ding B., Focsan M., Kogermann K., Pascoal-Faria P., Petronella F., Mitchell G., Zussmann E., Pierini F., Personalized reusable face masks with smart nano‐assisted destruction of pathogens for COVID‐19: a visionary road, Chemistry - A European Journal, ISSN: 0947-6539, DOI: 10.1002/chem.202004875, pp.1-49, 2020

Streszczenie:
The Coronavirus disease 2019 (COVID‐19) emergency has demonstrated that the utilization of face masks plays a critical role in limiting the outbreaks. Healthcare professionals utilize masks all day long without replacing them very frequently, thus representing a source of cross‐infection for patients and themselves. Nanotechnology is a powerful tool with the capability to produce nanomaterials with unique physicochemical and anti‐pathogen properties. Here, we outline how to realize non‐disposable and highly comfortable respirators with light‐triggered self‐disinfection ability by bridging bioactive nanofiber properties and stimuli‐responsive nanomaterials. The visionary road highlighted in this Concept is based on the possibility to develop a new generation of masks based on multifunctional membranes where the presence of nanoclusters and plasmonic nanoparticles arranged in a hierarchical structure enables the realization of a chemically‐driven and on‐demand anti‐pathogen activities. Multilayer electrospun membranes have the ability to dissipate humidity present within the mask, enhancing the wearability and usability. The photo‐thermal disinfected membrane is the core of these 3D printed and reusable masks with moisture pump capability. Personalized face masks with smart nano‐assisted destruction of pathogens will bring enormous advantages to the entire global community, especially for front‐line personnel, and will open up great opportunities for innovative medical applications.

Słowa kluczowe:
face masks, light-responsive nanomaterials, anti-pathogen, electrospinning, digitally personalized

(140p.)
31. Gluba-Brzózka A., Franczyk B., Olszewski R., Rysz J., The influence of inflammation on anemia in CKD patients, International Journal of Molecular Sciences, ISSN: 1422-0067, DOI: 10.3390/ijms21030725, Vol.21, No.3, pp.725-1-25, 2020

Streszczenie:
Anemia is frequently observed in the course of chronic kidney disease (CKD) and it is associated with diminishing the quality of a patient's life. It also enhances morbidity and mortality and hastens the KD progression rate. Patients with CKD frequently suffer from a chronic inflammatory state which is related to a vast range of underlying factors. The results of studies have demonstrated that persistent inflammation may contribute to the variability in Hb levels and hyporesponsiveness to erythropoietin stimulating agents (ESA), which are frequently observed in CKD patients. The understanding of the impact of inflammatory cytokines on erythropoietin production and hepcidin synthesis will enable one to unravel the net of interactions of multiple factors involved in the pathogenesis of the anemia of chronic disease. It seems that anti-cytokine and anti-oxidative treatment strategies may be the future of pharmacological interventions aiming at the treatment of inflammation-associated hyporesponsiveness to ESA. The discovery of new therapeutic approaches towards the treatment of anemia in CKD patients has become highly awaited. The treatment of anemia with erythropoietin (EPO) was associated with great benefits for some patients but not all.

Słowa kluczowe:
inflammation, chronic kidney disease, anemia, anemia of inflammation, ESA hyporesponsiveness

(140p.)
32. Rysz J., Franczyk B., Ławiński J., Olszewski R., Gluba-Brzózka A., The role of metabolic factors in renal cancers, International Journal of Molecular Sciences, ISSN: 1422-0067, DOI: 10.3390/ijms21197246, Vol.21, No.19, pp.7246-1-20, 2020

Streszczenie:
Anincreasing number of evidence indicates that metabolic factorsmayplay an important role in the evelopment and progression of certain types of cancers, including renal cell carcinoma (RCC). This tumour is the most common kidney cancer which accounts for approximately 3–5% of malignant tumours in adults. Numerous studies indicated that concomitant diseases, including diabetes mellitus (DM) and hypertension, as well as obesity, insulin resistance, and lipid disorders, may also influence the prognosis and cancer-specific overall survival. However, the results of studies concerning the impact of metabolic factors on RCC are controversial. It appears that obesity increases the risk of RCC development; however, it may be a favourable factor in terms of prognosis. Obesity is closely related to insulin resistance and the development of diabetes mellitus type 2 (DM2T) since the adipocytes in visceral tissue secrete substances responsible for insulin resistance, e.g., free fatty acids. Interactions between insulin and insulin-like growth factor (IGF) system appear to be of key importance in the development and progression of RCC; however, the exact role of insulin and IGFs in RCC pathophysiology remains elusive. Studies indicated that diabetes increased the risk of RCC, but it might not alter cancer-related survival. The risk associated with a lipid profile is most mysterious, as numerous studies provided conflicting results. Even though large studies unravelling pathomechanisms involved in cancer growth are required to finally establish the impact of metabolic factors on the development, progression, and prognosis of renal cancers, it seems that the monitoring of health conditions, such as diabetes, low body mass index (BMI), and lipid disorders is of high importance in clear-cell RCC.

Słowa kluczowe:
renal cell carcinoma, obesity, insulin resistance, diabetes mellitus, lipid disorders

(140p.)
33. Dakshinamurthy M., Kowalczyk-Gajewska K., Vadillo G., Influence of crystallographic orientation on the void growth at the grain boundaries in bi-crystals, INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, ISSN: 0020-7683, DOI: 10.1016/j.ijsolstr.2020.11.035, pp.1-39, 2020

Streszczenie:
Void growth and morphology evolution in fcc bi-crystals are investigated using crystal plasticity finite element method. For that purpose, representative volume element of bi-crystals with a void at the grain boundary are considered in the analysis. Grain boundary is assumed initially perpendicular/coaxial with the straight sides of the cell. Fully periodic boundary conditions are prescribed in the representative volume element and macroscopic stress triaxiality and Lode parameter are kept constant during the whole deformation process. Three different pairs of crystal orientations characterized as hard-hard, soft-soft and soft-hard have been employed for modelling the mechanical response of the bi-crystal. Simulations are performed to study the implications of triaxiality, Lode parameter and crystallographic orientation on slip mechanism, hardening and hence void evolution. The impact of void presence and its growth on the heterogeneity of lattice rotation and resulting grain fragmentation in neighbouring areas is also analysed and discussed.

Słowa kluczowe:
crystal plasticity, bi-crystals, void growth, stress triaxiality, Lode parameter, unit cell calculations

(140p.)
34. Radziejewska J., Strzelec M., Ostrowski R., Sarzyński A., Experimental investigation of shock wave pressure induced by a ns laser pulse under varying confined regimes, Optics and Lasers in Engineering, ISSN: 0143-8166, DOI: 10.1016/j.optlaseng.2019.105913, Vol.126, pp.105913-1-12, 2020

Streszczenie:
The article presents a study of shock waves induced by a nanosecond laser pulse in samples in the form of steel plates. Its contents include a description of the measurement system, methods of calculations and some characteristics of the measuring instruments and materials used. The quoted formulas enabled the processing of recorded measurement signals. The influence of material used as a confining layer (glass, PMMA - Plexiglass, water) and substrate (PMMA, aluminium, steel) on the amplitude and shape of recorded pressure waves was studied. Pressure behind the shock wave measurements were conducted using piezoelectric polymer PVDF (polivinylidene fluoride) sensors. Verifications of PVDF results were conducted by the measurements of velocity of back sample surface by VISAR (Velocity Interferometer System for Any Reflector). A qualitative compliance between the PVDF's pressure and VISAR's velocity rescaled to pressure was achieved. The strains (about 0.3%) and strain rates (about 3 × 10^5 1/sec) were evaluated. The obtained results will allow for a better selection of test conditions for studying material properties by using a shock wave induced by the laser pulse.

Słowa kluczowe:
laser pulse, shock wave, PVDF sensor, VISAR

(140p.)
35. Kochańczyk M., Grabowski F., Lipniacki T., Super-spreading events initiated the exponential growth phase of COVID-19 with R-0 higher than initially estimated, Royal Society Open Science, ISSN: 2054-5703, DOI: 10.1098/rsos.200786, Vol.7, No.9, pp.200786-1-9, 2020

Streszczenie:
The basic reproduction number R0 of the coronavirus disease 2019 has been estimated to range between 2 and 4. Here, we used an SEIR model that properly accounts for the distribution of the latent period and, based on empirical estimates of the doubling time in the near-exponential phases of epidemic progression in China, Italy, Spain, France, UK, Germany, Switzerland and New York State, we estimated that R0 lies in the range 4.7-11.4. We explained this discrepancy by performing stochastic simulations of model dynamics in a population with a small proportion of super-spreaders. The simulations revealed two-phase dynamics, in which an initial phase of relatively slow epidemic progression diverts to a faster phase upon appearance of infectious super-spreaders. Early estimates obtained for this initial phase may suggest lower R0.

Słowa kluczowe:
COVID-19, reproduction number

(100p.)
36. Ozen M., Lipniacki T., Levchenko A., Emamian E.S., Abdi A., Modeling and measurement of signaling outcomes affecting decision making in noisy intracellular networks using machine learning methods, Integrative Biology, ISSN: 1757-9708, DOI: 10.1093/intbio/zyaa009, Vol.12, No.5, pp.122-138, 2020

Streszczenie:
Characterization of decision-making in cells in response to received signals is of importance for understanding how cell fate is determined. The problem becomes multi-faceted and complex when we consider cellular heterogeneity and dynamics of biochemical processes. In this paper, we present a unified set of decision-theoretic, machine learning and statistical signal processing methods and metrics to model the precision of signaling decisions, in the presence of uncertainty, using single cell data. First, we introduce erroneous decisions that may result from signaling processes and identify false alarms and miss events associated with such decisions. Then, we present an optimal decision strategy which minimizes the total decision error probability. Additionally, we demonstrate how graphing receiver operating characteristic curves conveniently reveals the trade-off between false alarm and miss probabilities associated with different cell responses. Furthermore, we extend the introduced framework to incorporate the dynamics of biochemical processes and reactions in a cell, using multi-time point measurements and multi-dimensional outcome analysis and decision-making algorithms. The introduced multivariate signaling outcome modeling framework can be used to analyze several molecular species measured at the same or different time instants. We also show how the developed binary outcome analysis and decision-making approach can be extended to more than two possible outcomes. As an example and to show how the introduced methods can be used in practice, we apply them to single cell data of PTEN, an important intracellular regulatory molecule in a p53 system, in wild-type and abnormal cells. The unified signaling outcome modeling framework presented here can be applied to various organisms ranging from viruses, bacteria, yeast and lower metazoans to more complex organisms such as mammalian cells. Ultimately, this signaling outcome modeling approach can be utilized to better understand the transition from physiological to pathological conditions such as inflammation, various cancers and autoimmune diseases.

Słowa kluczowe:
Cell decision making, noise, decision theory, machine learning, signaling errors, p53 system

(100p.)
37. Starzyński G., Buczkowski R., Zyliński B., Deformation-induced roughening by contact compression in the presence of oils with different viscosity: experiment and numerical simulation, TRIBOLOGY LETTERS, ISSN: 1023-8883, DOI: 10.1007/s11249-020-01353-2, Vol.68, No.4, pp.117-1-14, 2020

Streszczenie:
The aim of the work is to show both the similarities and differences in the formation of deformation-induced roughness in contact compression in the presence of oil and the problem of free surface roughing during uniaxial stretching in a plastic area. The relationships between changes in the roughness are caused by the deformation of the sample and the viscosity of oil at the contact area. It has been shown that normal contact loading with the presence of oil initially leads to an increase in surface roughness, then to its smoothening. The results of the experimental research have been compared with numerical simulation made using FSI (Fluid Structure Interaction) and ABAQUS systems. Using finite element calculations, it was possible to explain the phenomenon of roughness formation on the surface of a smooth steel sample. The changes in the structure of the smooth surface resulting from compression in the presence of oil are caused by the rotation and deformation of surface grains. The roughness of this structure is dependent on the viscosity of oil: the more viscous the liquid is, the rougher texture is formed.

Słowa kluczowe:
deformation-induced roughening, viscosity, finite element method

(100p.)
38. Rezaee-Hajidehi M., Tůma K., Stupkiewicz S., A note on Padé approximants of tensor logarithm with application to Hencky-type hyperelasticity, COMPUTATIONAL MECHANICS, ISSN: 0178-7675, DOI: 10.1007/s00466-020-01915-0, pp.1-14, 2020

Streszczenie:
We show that the logarithmic (Hencky) strain and its derivatives can be approximated, in a straightforward manner and with a high accuracy, using Padé approximants of the tensor (matrix) logarithm. Accuracy and computational efficiency of the Padé approximants are favourably compared to an alternative approximation method employing the truncated Taylor series. As an application, Hencky-type hyperelasticity models are considered, in which the elastic strain energy is expressed in terms of the Hencky strain, and of our particular interest is the anisotropic energy quadratic in the Hencky strain. Finite-element computations are carried out to examine performance of the Padé approximants of tensor logarithm in Hencky-type hyperelasticity problems. A discussion is also provided on computation of the stress tensor conjugate to the Hencky strain in a general anisotropic case.

Słowa kluczowe:
logarithmic strain, Padé approximation method, hyperelasticity, anisotropy, finite-element method

(100p.)
39. Niemczyk-Soczyńska B., Gradys A., Sajkiewicz P., Hydrophilic surface functionalization of electrospun nanofibrous scaffolds in tissue engineering, Polymers, ISSN: 2073-4360, DOI: 10.3390/polym12112636, Vol.12, No.11, pp.2636-1-20, 2020

Streszczenie:
Electrospun polymer nanofibers have received much attention in tissue engineering due to their valuable properties such as biocompatibility, biodegradation ability, appropriate mechanical properties, and, most importantly, fibrous structure, which resembles the morphology of extracellular matrix (ECM) proteins. However, they are usually hydrophobic and suffer from a lack of bioactive molecules, which provide good cell adhesion to the scaffold surface. Post-electrospinning surface functionalization allows overcoming these limitations through polar groups covalent incorporation to the fibers surface, with subsequent functionalization with biologically active molecules or direct deposition of the biomolecule solution. Hydrophilic surface functionalization methods are classified into chemical approaches, including wet chemical functionalization and covalent grafting, a physiochemical approach with the use of a plasma treatment, and a physical approach that might be divided into physical adsorption and layer-by-layer assembly. This review discusses the state-of-the-art of hydrophilic surface functionalization strategies of electrospun nanofibers for tissue engineering applications. We highlighted the major advantages and drawbacks of each method, at the same time, pointing out future perspectives and solutions in the hydrophilic functionalization strategies.

Słowa kluczowe:
surface functionalization, electrospinning, polymers, nanofiber, immobilization, tissue engineering

(100p.)
40. Korczak I., Romowicz A., Gambin B., Palko T., Kruglenko E., Dobruch-Sobczak K., Numerical prediction of breast skin temperature based on thermographic and ultrasonographic data in healthy and cancerous breasts, Biocybernetics and Biomedical Engineering, ISSN: 0208-5216, DOI: 10.1016/j.bbe.2020.10.007, Vol.40, pp.1680-1692, 2020

Streszczenie:
Breast cancer is one of the most common women's cancers, so an available diagnostic modality, particularly non-invasive, is important. Infrared thermography (IRT) is a supporting diagnostic modality. Until now, many finite element methods (FEM) numerical models have been constructed to evaluate IRT's diagnostic value and to relate breast skin temperature characteristics with breast structural disorder presence, particularly to distinguish between cancerous types and normal structures. However, most of the models were not based on any clinical data, except for several papers based on clinical magnetic resonance imaging (MRI) data, wherein a three-dimensional (3D) breast model was studied. In our paper, we propose a very simplified numerical two-dimensional FEM model constructed based on clinical ultrasound data of breasts, which is much cheaper and available in realtime as opposed to MRI data. We show that our numerical simulations enabled us to distinguish between types of healthy breasts in agreement with the clinical classification and with thermographic results. The numerical breast models predicted the possibility of differentiation of cancerous breasts from healthy breasts by significantly different skin temperature variation ranges. The thermal variations of cancerous breasts were in the range of 0.5 8C–3.0 8C depending on the distance of the tumor from the skin surface, its size, and the cancer type. The proposed model, due to its simplicity and the fact that it was constructed based on clinical ultrasonographic data, can compete with the more sophisticated 3D models based on MRI.

Słowa kluczowe:
non-invasive cancer detection, Pennes' bioheat transfer equation, finite element method, breast thermography, ultrasonography

(100p.)
41. Pluta K.D., Samluk A., Wencel A., Zakrzewska K.E., Gora M., Burzynska B., Ciezkowska M., Motyl J., Pijanowska D.G., Genetically modified C3A cells with restored urea cycle for improved bioartificial liver, Biocybernetics and Biomedical Engineering, ISSN: 0208-5216, DOI: 10.1016/j.bbe.2019.12.006, Vol.40, No.1, pp.378-387, 2020

Streszczenie:
The bioartificial liver, a hybrid device aimed at improving the survival of patients with fulminant liver failure, requires a cell source to replicate human liver function. However, liver support systems that utilize porcine or human hepatoma-derived cells felt short of expectations in clinical trials. Here we present engineered C3A cells, with a restored function of the urea cycle, which can be used in an efficacious bioartificial liver. The genetic modification was performed using a lentiviral-mediated gene transfer which led to effective integration of the transgenes, coding for arginase I and ornithine transcarbamylase, into the target cell genomes. The engineered cells are more resistant to the oxidative/nitrosative stress induced by the presence of high concentrations of ammonia cations and produce more urea than their unmodified counterparts. Interestingly, the genetically modified cells secrete more albumin than control C3A cells and the synthesis of the protein is induced by increasing concentrations of ammonia. Although the physiological capabilities of the new cell line need to be further examined, at this stage of our study we may conclude that the genetically modified cells are able to convert ammonia to urea more effectively than regular C3A cells.

Słowa kluczowe:
bioartificial liver, genetically modified cells, lentiviral vectors, urea cycle

(100p.)
42. Wencel A., Ciezkowska M., Wisniewska M., Zakrzewska K.E., Pijanowska D.G., Pluta K.D., Effects of genetically modified human skin fibroblasts, stably overexpressing hepatocyte growth factor, on hepatic functions of cocultured C3A cells, Biotechnology & Bioengineering, ISSN: 0006-3592, DOI: 10.1002/bit.27551, pp.1-10, 2020

Streszczenie:
Diseases leading to terminal hepatic failure are among the most common causes of death worldwide. Transplant of the whole organ is the only effective method to cure liver failure. Unfortunately, this treatment option is not available universally due to the serious shortage of donors. Thus, alternative methods have been developed that are aimed at prolonging the life of patients, including hepatic cells transplantation and bridging therapy based on hybrid bioartificial liver devices. Parenchymal liver cells are highly differentiated and perform many complex functions, such as detoxification and protein synthesis. Unfortunately, isolated hepatocytes display a rapid decline in viability and liver‐specific functions. A number of methods have been developed to maintain hepatocytes in their highly differentiated state in vitro, amongst them the most promising being 3D growth scaffolds and decellularized tissues or coculture with other cell types required for the heterotypic cell‐cell interactions. Here we present a novel approach to the hepatic cells culture based on the feeder layer cells genetically modified using lentiviral vector to stably produce additional amounts of hepatocyte growth factor and show the positive influence of these coculture conditions on the preservation of the hepatic functions of the liver parenchymal cells' model—C3A cells.

Słowa kluczowe:
cell genetic modifications, growth surface engineering, hepatocyte growth factor, hepatocytes‐fibroblasts coculture, lentiviral vectors

(100p.)
43. Graczykowski C., Faraj R., Identification-based predictive control of semi-active shock-absorbers for adaptive dynamic excitation mitigation, MECCANICA, ISSN: 0025-6455, DOI: 10.1007/s11012-020-01239-6, Vol.55, No.12, pp.2571-2597, 2020

Streszczenie:
The paper is aimed at detailed discussion of the Identification-based Predictive Control (IPC) developed for semi-active fluid-based shock-absorbers which protect structures and machines against impact excitations. The problem addressed is the optimal impact absorption providing adaptive mitigation of dynamic response of the mechanical system. The goal of applied control is dissipation of the entire impact energy and minimization of the impacting object deceleration during the process. Three proposed implementations of the IPC are based on sequentially repeated procedures, which include identification of excitation parameters and calculation of the valve opening providing minimization of tracking error of the optimal path. The presented numerical examples concerning mitigation of the dynamic excitation acting on the double-chamber pneumatic shock-absorber reveal high efficiency and prove robustness of the proposed control methods. The developed algorithms are compared against each other in terms of path-tracking efficiency and character of required control actions. The most important challenges in practical implementation of the proposed methods are indicated.

Słowa kluczowe:
adaptive control, adaptive impact absorption, identification-based predictive control, model predictive control, self-adaptive shock-absorber, semi-active control

(100p.)
44. Zaszczyńska A., Gradys A., Sajkiewicz P., Progress in the applications of smart piezoelectric materials for medical devices, Polymers, ISSN: 2073-4360, DOI: 10.3390/polym12112754, Vol.12, No.11, pp.2754-1-19, 2020

Streszczenie:
Smart piezoelectric materials are of great interest due to their unique properties. Piezoelectric materials can transform mechanical energy into electricity and vice versa. There are mono and polycrystals (piezoceramics), polymers, and composites in the group of piezoelectric materials. Recent years show progress in the applications of piezoelectric materials in biomedical devices due to their biocompatibility and biodegradability. Medical devices such as actuators and sensors, energy harvesting devices, and active scaffolds for neural tissue engineering are continually explored. Sensors and actuators from piezoelectric materials can convert flow rate, pressure, etc., to generate energy or consume it. This paper consists of using smart materials to design medical devices and provide a greater understanding of the piezoelectric effect in the medical industry presently. A greater understanding of piezoelectricity is necessary regarding the future development and industry challenges.

Słowa kluczowe:
polymers, smart materials, piezoelectric materials, inorganic materials, organic materials, biomedical devices

(100p.)
45. Ario I., Yamashita T., Chikahiro Y., Nakazawa M., Fedor K., Graczykowski C., Pawłowski P., Structural analysis of a scissor structure, BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, DOI: 10.24425/bpasts.2020.134623, Vol.68, No.6, pp.1-14, 2020

Streszczenie:
This paper presents equilibrium mechanics and a finite element model for analysing a scissor structure that contains pivots with zero bending stiffness representing structural instability. The pivot at the centre of each structural unit, which is a feature of scissor structures, can be used to transfer the displacement between the units. It cannot, however, transfer the rotation between these units, and the angular stiffness must be considered independently for each unit. To construct a general model of the scissor structure, a scissor unit was developed using the left and right boundary connections of adjacent units to simulate a periodically symmetric structure. The proposed method allows us to obtain an accurate distribution of the internal forces and deflections without the use of special elements to account for central pivots.

Słowa kluczowe:
scissor structure, deployable structure, smart bridge, scissors finite element, equilibrium mechanics

(100p.)
46. Strojny-Nędza A., Egizabal P., Pietrzak K., Zieliński R., Kaszyca K., Piątkowska A., Chmielewski M., Corrosion and thermal shock resistance of metal (Cu, Al) matrix composites reinforced by SiC particles, BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, DOI: 10.24425/bpasts.2020.134644, Vol.68, No.5, pp.1227-1236, 2020

Streszczenie:
This paper presents the results of studies concerning the production and characterization of Al-SiC/W and Cu-SiC/W composite materials with a 30% volume fraction of reinforcing phase particles as well as the influence of corrosion and thermal shocks on the properties of selected metal matrix composites. Spark plasma sintering method (SPS) was applied for the purpose of producing these materials. In order to avoid the decomposition of SiC surface, SiC powder was coated with a thin tungsten layer using plasma vapour deposition (PVD) method. The obtained results were analysed by the effect of the corrosion and thermal shocks on materials density, hardness, bending strength, tribological and thermal properties. Qualitative X-ray analysis and observation of microstructure of sample surfaces after corrosion tests and thermal shocks were also conducted. The use of PVD technique allows us to obtain an evenly distributed layer of titanium with a constant thickness of 1.5 μm. It was found that adverse environmental conditions and increased temperature result in a change in the material behaviour in wear tests.

Słowa kluczowe:
metal-matrix composites, silicon carbide, wear resistance, corrosion, thermal shocks

(100p.)
47. Krajewski M., Świątkowski A., Skrzypczyńska K., Osawaru O., Pawluk K., Iron nanoparticles and nanowires as modifiers of carbon paste electrodes for the detection of traces of copper, lead and zinc ions in water, Desalination and Water Treatment, ISSN: 1944-3994, DOI: 10.5004/dwt.2020.26469, pp.1-8, 2020

Streszczenie:
This work describes the application of nano-iron modified carbon paste electrodes (CPEs) for the detection of copper, lead and zinc ions in aqueous solutions. The CPEs were manufactured by mixing commercial graphite powder with mineral oil and two types of iron nanomaterials, namely iron nanoparticles (Fe-NPs) and iron nanowires (Fe-NWs) whose preparation processes and properties were also presented herein. Preliminary electrochemical results showed that the CPEs modified with Fe-NWs (10% relative to the graphite) possessed a larger electrochemically active surface area in a comparison with unmodified electrodes and those modified with Fe-NPs. The current responses of investigated electrodes depended on the type of metal ion and its concentration. Contrary to previous literature reports on the modification of CPEs, higher current responses and lower detection limits were found for electrodes prepared with Fe-NWs. This indicates that the Fe-NWs constitute a promising modifier of CPEs for sensor application.

Słowa kluczowe:
carbon paste electrode, iron nanoparticles, iron nanowires, magnetic-field-induced synthesis, metal ion detection

(100p.)
48. Levintant-Zayonts N., Starzyński G., Kucharski S., On the origin of superiority in wear response of superelastic NiTi compared to conventional Ti6Al4V, TRIBOLOGY TRANSACTIONS, ISSN: 1040-2004, DOI: 10.1080/10402004.2020.1836295, pp.1-15, 2020

Streszczenie:
The difference in wear behaviour of superelastic NiTi and conventional Ti6Al4V alloys with similar elastic limits was investigated. Reciprocating dry-sliding wear tests were performed with a ball-on-plate tribometer machine at different normal loads and sliding times. Mechanical properties were also examined using different microindentation tests, and wear track morphologies and chemical compositions in the scar area were characterised by scanning electron microscopy and energy dispersive spectrometry. Superelasticity of the NiTi alloy was significantly beneficial to its tribological properties, and wear resistance of the NiTi alloy was up to forty times higher than that of the Ti6Al4V alloy. Such a significant difference cannot be attributed only to the relatively small difference in hardness (H) or H/E ratios (E - elastic modulus) of the materials but, rather, a difference in strain energy, which dissipates in the material and results from normal load of the sliding ball. To estimate this energy, spherical microindentation tests in wear scar were carried out. Understanding the difference between tribological behaviour of the NiTi shape memory alloy and the conventional Ti6Al4V material provides insight into wear progression, and an investigation of its mechanisms can effectively prevent the destruction of components, prolonging their safe service life.

Słowa kluczowe:
wear mechanisms, unlubricated friction, non-ferrous alloys, titanium

(100p.)
49. Girard G., Frydrych K., Kowalczyk-Gajewska K., Martiny M., Mercier S., Cyclic response of electrodeposited copper films. Experiments and elastic-viscoplastic mean-field modeling, Mechanics of Materials, ISSN: 0167-6636, DOI: 10.1016/j.mechmat.2020.103685, pp.1-46, 2020

Streszczenie:
The goal of the present work is to identify and model the elastic-viscoplastic behavior of electrodeposited copper films under tension-compression loadings. From the experimental point of view, as proposed in the literature, a film of copper is electrodeposited on both sides of an elastic compliant substrate. The overall specimen is next subjected to tensile loading-unloadings. As the substrate remains elastic, the elastic–plastic response of copper under cyclic loading is experimentally determined. A clear kinematic hardening behavior is captured. To model the mechanical response, a new elastic-viscoplastic self-consistent scheme for polycrystalline materials is proposed. The core of the model is the tangent additive interaction law proposed in Molinari (2002). The behavior of the single grain is rate dependent where kinematic hardening is accounted for in the model at the level of the slip system. The model parameters are optimized via an evolutionary algorithm by comparing the predictions to the experimental cyclic response. As a result, the overall response is predicted. In addition, the heterogeneity in plastic strain activity is estimated by the model during cyclic loading.

Słowa kluczowe:
electrodeposited copper, self-consistent scheme, elasto-viscoplasticity, kinematic hardening, experiments

(100p.)
50. Chernyshova M., Malinowski K., Czarski T., Demchenko I.N., Melikhov Y., Kowalska-Strzęciwilk E., Wojeński A., Krawczyk R.D., Effect of charging-up and regular usage on performance of the triple GEM detector to be employed for plasma radiation monitoring, Fusion Engineering and Design, ISSN: 0920-3796, DOI: 10.1016/j.fusengdes.2020.111755, Vol.158, pp.111755-1-6, 2020

Streszczenie:
After the problem of high-temperature plasma confinement, construction of diagnostics that is able to identify plasma contamination with impurities and to determine impurity distribution is another critically important issue. Solution of this problem would enable progress towards the success in controlled thermonuclear fusion. A new diagnostics, based on Gas Electron Multiplier (GEM) technology, has been recently developed for poloidal tomography focused on radiation of the metal impurities by monitoring in Soft X-Ray (SXR) region. GEM based detectors would undergo much less damage by neutrons than standard semiconductor diodes which results in better operational stability. This paper emphasizes the results of the latest examination of this type of detectors, showing influence of the charging-up effect on the detector performance and its physical properties for expected plasma radiation intensity. In addition, an undesired influence of aging of the detector window's material on the performance of the GEM detector is also shown: regular (moderate or active) usage could lead to changes of material's morphology as well as its composition. This study confirms the importance of further research into material’s optimization of GEM detectors used as a base for SXR tomographic diagnostics aimed to work under different plasma radiation conditions.

Słowa kluczowe:
nuclear instruments for hot plasma diagnostics, X-ray detectors, electron multipliers (gas), micropattern gaseous detectors, charging-up effect, detector window's material

(100p.)
51. Demchenko I.N., Melikhov Y., Walczak M.S., Ratajczak R., Sobczak K., Barcz A., Minikaev R., Dynowska E., Domagała J.Z., Chernyshova M., Syryanyy Y., Gavrilov N.V., Sawicki M., Effect of rapid thermal annealing on damage of silicon matrix implanted by low-energy rhenium ions, JOURNAL OF ALLOYS AND COMPOUNDS, ISSN: 0925-8388, DOI: 10.1016/j.jallcom.2020.156433, Vol.846, pp.156433-1-10, 2020

Streszczenie:
The structural, electronic, and magnetic properties of low-energy rhenium implanted c-Si are examined for the first time. The damage created by rhenium ions and the following partial reconstruction of the silicon host matrix after rapid thermal annealing (RTA) are investigated as a function of the fluence. Rutherford backscattering spectrometry (RBS) results reveal that the implanted ions are located in the near-surface region with the distribution maximum at about 23 nm below the surface. The analysis of rhenium-depth distribution using the McChasy code shows that the implanted Re-ions are located in the interstitial lattice positions. The RTA leads to a partial recovery of the silicon crystal structure. According to the RBS results, the formed inclusions are not coherent with the silicon host matrix causing an increase of the lattice distortion. Analysis of channeled RBS/c spectra carried out by the McChasy code revealed different levels of bent channels in damaged regions suggesting bimodal distribution of inclusions in the silicon. Studies of high-resolution X-ray photoelectron spectroscopy (XPS) conducted after the RTA showed the shift of Re 4f7/2 binding energy (BE) by +0.68 and + 0.85 eV with respect to metallic rhenium for the samples with lower/higher fluencies, respectively. Complex XPS, density functional theory (DFT) simulations, and transmission electron microscopy (TEM) data analysis allowed us to conclude that the near-surface layer of the sample (~10 nm) consists of nanoinclusions with cubic and/or hexagonal ReSi. In the middle area of the samples, much larger nanoinclusions (>10/20 nm for higher/lower fluencies, respectively) containing pure metallic rhenium inside are formed. The RTA increases the magnetic moment of the sample with the lower dose nearly 20-fold, whereas in the sample with the higher dose a 3-fold increment is observed only. The magnetic response of the examined systems after the RTA indicates a presence of magnetic interactions between the nanoinclusions resulting in the system exhibiting super-spin glass or super-ferromagnetism.

Słowa kluczowe:
rhenium-implanted silicon, RBS, XPS, RTA, TEM, DFT

(100p.)
52. Wang Y., Melikhov Y., Meydan T., Yang Z., Wu D., Wu B., He C., Liu X., Stress-dependent magnetic flux leakage: finite element modelling simulations versus experiments, JOURNAL OF NONDESTRUCTIVE EVALUATION, ISSN: 0195-9298, DOI: 10.1007/s10921-019-0643-0, Vol.39, pp.1-1-9, 2020

Streszczenie:
Assessing the effect of defect induced stresses on magnetic flux leakage (MFL) signals is a complicated task due to nonlinear magnetomechanical coupling. To facilitate the analysis, a multi-physics finite elemental simulation model is proposed based on magnetomechanical theory. The model works by quasi-statically computing the stress distribution in the specimen, which is then inherited to solve the nonlinear magnetic problem dynamically. The converged solution allows identification and extraction of the MFL signal induced by the defect along the sensor scanning line. Experiments are conducted on an AISI 1045 steel specimen, i.e. a dog-bone shaped rod with a cylindrical square-notch defect. The experiments confirm the validity of the proposed model that predicted a linear dependency of the peak-to-peak amplitude of the normalized MFL signal on applied stress. Besides identifying the effect of stress on the induced MFL signal, the proposed model is also suitable for solving the inverse problem of sizing the defects when stress is involved.

Słowa kluczowe:
magnetic flux leakage, magnetomechanics, Jiles–Atherton model, non-destructive testing, finite element method, multiphysics numerical simulation

(100p.)
53. Ostrowski M., Błachowski B., Bocheński M., Piernikarski D., Filipek P., Janicki W., Design of nonlinear electromagnetic energy harvester equipped with mechanical amplifier and spring bumpers, BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, DOI: 10.24425/bpasts.2020.135384, Vol.68, No.6, pp.1-11, 2020

Streszczenie:
The main drawback of vibration-based energy harvesting is its poor efficiency due to small amplitudes of vibration and low sensitivity at frequencies far from resonant frequency. The performance of electromagnetic energy harvester can be improved by using mechanical enhancements such as mechanical amplifiers or spring bumpers. The mechanical amplifiers increase range of movement and velocity, improving also significantly harvester efficiency for the same level of excitation. As a result of this amplitude of motion is much larger comparing to the size of the electromagnetic coil. This in turn imposes the need for modelling of electromagnetic circuit parameters as the function of the moving magnet displacement. Moreover, high velocities achieved by the moving magnet reveal nonlinear dynamics in the electromagnetic circuit of the energy harvester. Another source of nonlinearity is the collision effect between magnet and spring bumpers. It has been shown that this effect should be carefully considered during design process of the energy harvesting device. The present paper investigates the influence of the above-mentioned nonlinearities on power level generated by the energy harvester. A rigorous model of the electromagnetic circuit, derived with aid of the Hamilton's principle of the least action, has been proposed. It includes inductance of the electromagnetic coil as the function of the moving magnet position. Additionally, nonlinear behaviour of the overall electromagnetic device has been tested numerically for the case of energy harvester attached to the quarter car model moving on random road profiles. Such a source of excitation provides wide band of excitation frequencies, which occur in variety of real-life applications.

Słowa kluczowe:
energy harvesting, velocity amplification, nonlinear electromagnetic circuit, spring bumper, quarter car model

(100p.)
54. Chen W.C., Kaźmierczak B., Traveling waves in quadratic autocatalytic systems with complexing agent, DISCRETE AND CONTINUOUS DYNAMICAL SYSTEMS-SERIES B, ISSN: 1531-3492, DOI: 10.3934/dcdsb.2020364, pp.1-16, 2020

Streszczenie:
The quadratic autocatalytic reaction forms a key step in a number of chemical reaction systems, and traveling waves are observed in such systems. In this study, we investigate the effect of complexation reactions on traveling waves in the quadratic autocatalytic reaction system. More precisely, under the assumption that the complexation reaction is fast relative to the autocatalytic reaction, we show that the governing system is reduced to a two-component reaction-diffusion system with density-dependent diffusivity. Further, the numerical evidence suggests that for some parameter values, a traveling wave solution of this reduced two-component system is nonlinearly selected. This is contrast to that associated with the quadratic autocatalytic reaction (without complexation reactions).

Słowa kluczowe:
quadratic autocatalysis, complexing agent, fast reaction, traveling waves

(100p.)
55. Kuczera K., Jas G.S., Ekiel-Jeżewska M.L., Melikhov Y., Reorientation motions of N-acetyl-tryptophan-amide (NATA dipeptide) in aqueous solution and with co-solvents: molecular dynamics vs hydrodynamic model, PHYSICS OF FLUIDS, ISSN: 1070-6631, DOI: 10.1063/5.0031554, Vol.32, pp.127111-1-14, 2020

Streszczenie:
We present a study of peptide reorientational dynamics in solution analyzed from the perspective of fluorescence anisotropy decay (FAD) experiments, and atomistic molecular dynamics (MD) and continuum hydrodynamics modeling. Earlier, FAD measurements and MD simulations of the model dipeptide N-acetyltryptophanamide (NATA) in explicit water and in aqueous solutions of urea, guanidinium chloride, and proline co-solvents identified excellent agreement of MD results with experimental data, indicating the presence of significant effects of peptide–solvent interactions, and the overall tumbling of the peptide could be well described by contributions from individual conformers, represented by dihedral-restrained MD. Here, we extend these studies by analyzing dynamic inhomogeneity in the solutions and by developing a hydrodynamic model (HM) of the conformer dynamics. The MD simulation data indicate the presence of markedly different dynamic microenvironments for the four studied solutions, with the average water reorientations being different in all systems, partly reflecting the bulk viscosities. Additionally, the water dynamics also exhibited a marked slowdown in the vicinity of the co-solvents, especially chloride and proline. To gain further insight, we applied the HM to predict rotational correlation times of tryptophan for the individual NATA conformers identified in MD. The hydrodynamic results were in very good agreement with MD simulations for the individual structures, showing that the HM model provides a realistic description of rotational diffusion for rigid peptide structures. Overall, our study generated new microscopic insights into the complex nature of the structure and dynamics of peptide solvation shells for systems containing water and denaturing and stabilizing co-solvents.

(100p.)
56. Radziejewska J., Psiuk R., Mościcki T., Characterization and wear response of magnetron sputtered W–B and W–Ti–B coatings on WC–Co tools, Coatings, ISSN: 2079-6412, DOI: 10.3390/coatings10121231, Vol.10, No.12, pp.1231-1-13, 2020

Streszczenie:
In this work, α-WB2 and (W,Ti)B2 borides were applied as wear-resistant coatings to commercial WC–Co cutting inserts. Properties of coatings deposited by magnetron sputtering on WC–Co tools were studied. The crystal structure and chemical composition were analyzed. Vickers hardness and surface roughness were determined and wear test in semi-dry conditions was performed. The W–B and W–Ti–B coatings deposited on WC–Co substrate were smooth and very hard. However, titanium alloy W-B films with Vickers hardness of 3630 ± 260 HV0.02 were characterized by lower adhesion to the substrate, influencing the wear mechanism. Turning tests carried out on 304 stainless steel showed that the W–B film caused less wear compared to uncoated insert. Moreover, when W–B coating was applied, flank wear was reduced by 30% compared to uncoated WC–Co insert. Additionally, coating prevented chipping of the edge during cutting under test conditions. The research shows that W–B film deposited by magnetron sputtering has great potential as a coating for cutting tools for difficult-to-cut materials.

Słowa kluczowe:
PVD coatings, wear resistance, transition metal borides, cutting tools

(100p.)
57. Gadomska‐Gajadhur A., Kruk A., Dulnik J., Chwojnowski A., New polyester biodegradable scaffolds for chondrocyte culturing: preparation, properties, and biological activity, JOURNAL OF APPLIED POLYMER SCIENCE, ISSN: 0021-8995, DOI: 10.1002/app.50089, pp.e50089-1-14, 2020

Streszczenie:
An innovative modification of the wet inversion phase method, consisting in the use of a polymer nano‐nonwoven as a nonclassic pore precursor. Mechanical properties of the obtained scaffolds were determined, their hydrophilic properties (serum absorbability) were tested, and the content of residues of materials used in the scaffold preparation was determined. Nontoxicity of the developed scaffolds toward T lymphocyte cells was proved. Cultures of primary chondrocytes were obtained successfully. It was proved that an addition of a polymer nano‐nonwoven changes the properties of the scaffolds favorably in respect of their subsequent application in tissue engineering.

Słowa kluczowe:
cartilage regeneration, chondrocytes, nano-nonwoven, polyvinylpyrrolidone, T lymphocytes

(70p.)
58. Chatterjee P., Glimm T., Kaźmierczak B., Mathematical modeling of chondrogenic pattern formation during limb development: recent advances in continuous models, MATHEMATICAL BIOSCIENCES, ISSN: 0025-5564, DOI: 10.1016/j.mbs.2020.108319, Vol.322, pp.108319-1-17, 2020

Streszczenie:
The phenomenon of chondrogenic pattern formation in the vertebrate limb is one of the best studied examples of organogenesis. Many different models, mathematical as well as conceptual, have been proposed for it in the last fifty years or so. In this review, we give a brief overview of the fundamental biological background, then describe in detail several models which aim to describe qualitatively and quantitatively the corresponding biological phenomena. We concentrate on several new models that have been proposed in recent years, taking into account recent experimental progress. The major mathematical tools in these approaches are ordinary and partial differential equations. Moreover, we discuss models with non-local flux terms used to account for cell-cell adhesion forces and a structured population model with diffusion. We also include a detailed list of gene products and potential morphogens which have been identified to play a role in the process of limb formation and its growth.

Słowa kluczowe:
mathematical models of chondrogenesis, reaction-diffusion equations, pattern formation, limb development

(70p.)
59. Fabbrocino F., Darban H., Luciano R., Nonlocal layerwise formulation for interfacial tractions in layered nanobeams, Mechanics Research Communications, ISSN: 0093-6413, DOI: 10.1016/j.mechrescom.2020.103595, Vol.109, pp.103595-1-5, 2020

Streszczenie:
Interfacial tractions generated at the interface in two-layered nanobeams are studied through the stress-driven nonlocal theory of elasticity and an interface model. The model uses a layerwise description of the problem and satisfies the continuity conditions at the interface. The size-dependency are incorporated into formulation through a nonlocal constitutive law which defines the strain at each point as an integral convolution in terms of the stresses in all the points and a kernel. The Bernoulli-Euler beam theory is used separately for each layer to describe kinematic field, and to derive size-dependent system of coupled governing equations. The displacement components within the layers are derived and the interfacial tractions are obtained through the interfacial constitutive relations. Results are presented for the interfacial shear and normal tractions, exhibiting a different behavior at the nano-scale compared to those of the layered beams with large-scale dimensions including different maximum interfacial tractions and the location where maxima occur. A superior resistance of nanobeams against debondings and delaminations due to the interfacial normal tractions compared to that of the beams with large-scale dimensions is observed. The formulation and the understandings presented here are expected to stimulate further researches on multilayered nanobeams, including their interfacial fracture mechanics.

Słowa kluczowe:
multilayered nanobeams, weak bonding, interfacial tractions, delamination, nonlocal elasticity

(70p.)
60. Nowicki A., Gambin B., Secomski W., Trawiński Z., Szubielski M., Olszewski R., Does flow-mediated dilation normalization for base-scaled shear rate improve its value in coronary artery disease?, ULTRASOUND IN MEDICINE AND BIOLOGY, ISSN: 0301-5629, DOI: 10.1016/j.ultrasmedbio.2020.05.018, Vol.46, No.9, pp.2551-2555, 2020

Streszczenie:
The article presents a new normalization of flow-mediated dilation (FMD) in the radial artery, taking into account the parameter BSSR being equal to the ratio of the basal shear rate (BS) measured before the cuff inflation and post occlusive shear rate (SR). The in vivo usefulness of the new normalization algorithm wasevaluated in two groups of patients. In group I, comprising 15 healthy volunteers, the normalized FMD/SR was(3.19 ± 1.4)*10^-4, while in group II, comprising 13 patients with stable coronary artery disease (CAD), it was(1.02 ± 0.76)*10^-4. We calculated almost 50% larger difference between the average values after normalizing FMD/BSSR. Specifically, the FMD/BSSR was equal to 28 ± 9.40 in group I and 6.01 ± 3.74 in group II. The prediction of CAD patients based on FMD/SR values had a sensitivity of 83.3% and a specificity of 84.6%, whereas the prediction of CAD patients based on the FMD/BSSR values revealed 100% sensitivity and specificity. These results confirm the usefulness of the novel normalization algorithm of the FMD in differentiation of normal patients from those with stable CAD.

Słowa kluczowe:
flow-mediated vasodilation, radial artery, shear rate, pulsed Doppler, ultrasonography, coronary artery disease

(70p.)
61. Bajkowski J.M., Dyniewicz B., Bajer C.I., Bajkowski J., An experimental study on granular dissipation for the vibration attenuation of skis, Proceedings of the Institution of Mechanical Engineers, ISSN: 1754-338X, DOI: 10.1177/1754337120964015, pp.1-8, 2020

Streszczenie:
Due to the continuous deformations and irregularities of the surface of snow, alpine skis exhibit dynamic excitation, leading to drastic vibrations and decreased manoeuvrability. Therefore, attenuating these unwanted vibrations, while ensuring that the ski experience is not compromised, is an important challenge. The possibility of using granular material in a damping device is studied in this paper. A container that was partially filled with loose granules was fixed at the tip of an alpine ski to suppress vibrations by dissipating energy through collisions. The performance was verified experimentally by studying the transient response of a ski mounted in a horizontal cantilever orientation. Moreover, on-snow tests were performed. Different numbers of plastic granules were used as a dissipating material. To identify the nonlinear damping characteristics of the system, a Hilbert transform was used. In the laboratory test, the displacement amplitude decay was up to 16 percentage points higher when a granular dissipator was attached to the ski than without the damper. During field testing, acceleration amplitudes were 9% lower compared to the ski without the dissipator. This solution could possibly be adapted to other boardsports on a wide variety of terrain, including ground, water and snow.

Słowa kluczowe:
vibration damping, alpine ski, granular material, Hilbert transform, bending beam

(70p.)
62. Białobrzeska W., Firganek D., Czerkies M., Lipniacki T., Skwarecka M., Dziąbowska K., Cebula Z., Malinowska N., Bigus D., Bięga E., Pyrć K., Pala K., Żołędowska S., Nidzworski D., Electrochemical immunosensors based on screen-printed gold and glassy carbon electrodes: comparison of performance for respiratory syncytial virus detection, Biosensors, ISSN: 2079-6374, DOI: 10.3390/bios10110175, Vol.10, No.11, pp.175-1-13, 2020

Streszczenie:
This paper presents the development and comparison of label-free electrochemical immunosensors based on screen-printed gold and glassy carbon (GC) disc electrodes for efficient and rapid detection of respiratory syncytial virus (RSV). Briefly, the antibody specific to the F protein of RSV was successfully immobilized on modified electrodes. Antibody coupling on the Au surface was conducted via 4-aminothiophenol (4-ATP) and glutaraldehyde (GA). The GC surface was modified with poly-L-lysine (PLL) for direct anti-RSV conjugation after EDC/NHS (1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-Hydroxysuccinimide) activation. Electrochemical characterizations of the immunosensors were carried out by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). GC-based immunosensors show a dynamic range of antigen detection from 1.0 × 10^5 PFU/mL to 1.5×10^7 PFU/mL, more than 1.0 × 10^5 PFU/mL to 1.0 × 10^7 PFU/mL for the Au-based sensor. However, the GC platform is less sensitive and shows a higher detection limit (LOD) for RSV. The limit of detection of the Au immunosensor is 1.1 × 10^3 PFU/mL, three orders of magnitude lower than 2.85 × 10^6 PFU/mL for GC. Thus, the Au-based immunosensor has better analytical performance for virus detection than a carbon-based platform due to high sensitivity and very low RSV detection, obtained with good reproducibility.

Słowa kluczowe:
respiratory syncytial virus, cyclic voltammetry, electrochemical impedance spectroscopy, sensor, gold electrode, glassy carbon

(70p.)
63. Vantadori S., Luciano R., Scorza D., Darban H., Fracture analysis of nanobeams based on the stress-driven non-local theory of elasticity, MECHANICS OF ADVANCED MATERIALS AND STRUCTURES, ISSN: 1537-6494, DOI: 10.1080/15376494.2020.1846231, pp.1-10, 2020

Streszczenie:
Mode I fracture behavior of edge- and centrally-cracked nanobeams is analyzed by employing both stress-driven non-local theory of elasticity and Bernoulli–Euler beam theory. The present formulation implements the size-dependency experimentally observed at material micro- and nanoscale, by assuming a non-local constitutive law, that relates the strain to the stress in each material point of the body, through an integral convolution and a kernel. It is observed that the energy release rate decreases by increasing the nonlocality, showing the superior fracture performance of nanobeams with respect to large-scale beams.

Słowa kluczowe:
energy release rate, nanobeam, stress-driven, non-local integral model, stress intensity factor

(70p.)
64. Koza P., Przybyś J., Klejman A., Olech-Kochańczyk G., Konopka W., Generation of transgenic rats using a lentiviral vector approach, Journal of Visualized Experiments, ISSN: 1940-087X, DOI: 10.3791/60570, Vol.159, pp.e60570-1-8, 2020

Streszczenie:
Transgenic animal models are fundamentally important for modern biomedical research. The incorporation of foreign genes into early mouse or rat embryos is an invaluable tool for gene function analysis in living organisms. The standard transgenesis method is based on microinjecting foreign DNA fragments into a pronucleus of a fertilized oocyte. This technique is widely used in mice but remains relatively inefficient and technically demanding in other animal species. The transgene can also be introduced into one-cell-stage embryos via lentiviral infection, providing an effective alternative to standard pronuclear injections, especially in species or strains with a more challenging embryo structure. In this approach, a suspension that contains lentiviral vectors is injected into the perivitelline space of a fertilized rat embryo, which is technically less demanding and has a higher success rate. Lentiviral vectors were shown to efficiently incorporate the transgene into the genome to determine the generation of stable transgenic lines. Despite some limitations (e.g., Biosafety Level 2 requirements, DNA fragment size limits), lentiviral transgenesis is a rapid and efficient transgenesis method. Additionally, using female rats that are mated with a fertile male strain with a different dominant fur color is presented as an alternative to generate pseudopregnant foster mothers.

Słowa kluczowe:
retraction, issue 159, transgenic rat, lentiviral vectors, perivitelline space, foster mothers

(70p.)
65. Kang C.Y., Krajewski M., Lin J.Y., Impact of titanium precursors on formation and electrochemical properties of Li4Ti5O12 anode materials for lithium-ion batteries, Journal of Solid State Electrochemistry, ISSN: 1432-8488, DOI: 10.1007/s10008-020-04831-8, pp.1-8, 2020

Streszczenie:
This work describes comparative study on the application of Li4Ti5O12 (LTO) as anode materials for lithium-ion batteries which were successfully prepared by sol-gel synthesis with the use of two titanium sources. One of them was anatase-type titanium dioxide (TiO2), whereas the second was tetrabutyl titanate (TBT). Both obtained LTO materials were very similar in terms of their crystallinity and purity. In turn, the sample synthetized with TBT source revealed better particle dispersibility, and its particles were slightly lower in size. These particular features resulted in higher Li+ diffusion coefficient and better kinetic of Li+ ions during charge transfer reactions for the LTO synthetized with TBT source. This reflected in specific capacitance values for both electrodes which equalled 150 mAh g^−1, 120 mAh g^−1, and 63 mAh g^−1 for TBT-LTO and 120 mAh g^−1, 80 mAh g^−1, and 58 mAh g^−1 for TiO2-LTO at C-rates of 1, 5, and 10 C, respectively.

Słowa kluczowe:
anodematerial, lithiumtitanate, lithium-ion batteries, sol-gel synthesis, tetrabutyl titanate, titaniumdioxide

(70p.)
66. Dobkowska-Chudon W., Wróbel M., Frankowska E., Zegadło A., Krupniewicz A., Nowicki A., Olszewski R., Comparison of acoustocerebrography measurement and magnetic resonance imaging methods in the assessment of white matter lesions in patients with atrial fibrillation, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, DOI: 10.24425/aoa.2020.134060, Vol.45, No.3, pp.445-452, 2020

Streszczenie:
The brain is subject to damage, due to ageing, physiological processes and/or disease. Some of the damage is acute in nature, such as strokes; some is more subtle, like white matter lesions. White matter lesions or hyperintensities (WMH) can be one of the first signs of micro brain damage. We implemented the Acoustocerebrography (ACG) as an easy to use method designed to capture differing states of human brain tissue and the respective changes. Aim: The purpose of the study is to compare the efficacy of ACG and Magnetic Resonance Imaging (MRI) to detect WMH in patients with clinically silent atrial fibrillation (AF). Methods and results: The study included 97 patients (age 66.26 ± 6.54 years) with AF. CHA2DS2- VASc score (2.5 ±1.3) and HAS BLED (1.65 ± 0.9). According to MRI data, the patients were assigned into four groups depending on the number of lesions: L0 – 0 to 4 lesions, L5 – 5 to 9 lesions, L10 – 10 to 29 lesions, and L30 – 30 or more lesions. Authors found that the ACG method clearly differentiates the groups L0 (with 0–4 lesions) and L30 (with more than 30 lesions) of WMH patients. Fisher's Exact Test shows that this correlation is highly significant (p < 0.001). Conclusion: ACG is a new, easy and cost-effective method for detecting WMH in patients with atrial fibrillation. The ACG measurement methodology should become increasingly useful for the assessment of WMH.

Słowa kluczowe:
acoustocerebrography, brain MRI, atrial fibrillation, white matter hyperintensities

(70p.)
67. Kiełczyński P., Szalewski M., Balcerzak A., Wieja K., Impact of losses on Love wave propagation in multilayered composite structures loaded with a Newtonian liquid, JOURNAL OF VIBRATION AND CONTROL, ISSN: 1077-5463, DOI: 10.1177/1077546320916041, Vol.26, No.23-24, pp.2221-2229, 2020

Streszczenie:
In this study, we analyze theoretically and numerically the properties of Love surface waves propagating in lossy multilayered composite waveguides, loaded on the upper surface with a Newtonian liquid. The propagation of Love surface waves was formulated in terms of a direct Sturm–Liouville problem. An analytical form of the complex dispersion equation of the Love surface wave was derived using the Thomson–Haskell transfer matrix method. By separating the complex dispersion equation into its real and imaginary parts, we obtained a set of two nonlinear algebraic equations, which were subsequently solved numerically. The effect of various physical parameters of the lossy viscoelastic waveguide on the velocity and attenuation of the Love surface wave was then analyzed numerically. It was found that because of the presence of losses in the analyzed waveguide, Love surface waves displayed a number of new original phenomena, such as resonant-like maxima in attenuation as a function of thicknesses h1 of the first viscoelastic surface layer and thickness h2 of the second elastic surface layer. These phenomena are completely absent in lossless waveguides.

Słowa kluczowe:
lossy waveguides, nondestructive testing of polymeric layered structures, Love surface waves, viscoelastic materials

(70p.)
68. Kiełczyński P., Szalewski M., Balcerzak A., Wieja K., Dispersion curves of Love waves in elastic waveguides loaded with a Newtonian liquid layer of finite thickness, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, DOI: 10.24425/aoa.2019.129738, Vol.45, No.1, pp.19-27, 2020

Streszczenie:
In this paper, the authors analyse the propagation of surface Love waves in an elastic layered waveguide (elastic guiding layer deposited on an elastic substrate) covered on its surface with a Newtonian liquid layer of finite thickness. By solving the equations of motion in the constituent regions (elastic substrate, elastic surface layer and Newtonian liquid) and imposing the appropriate boundary conditions, the authors established an analytical form of the complex dispersion equation for Love surface waves. Further, decomposition of the complex dispersion equation into its real and imaginary part, enabled for evaluation of the phase velocity and attenuation dispersion curves of the Love wave. Subsequently, the influence of the finite thickness of a Newtonian liquid on the dispersion curves was evaluated. Theoretical (numerical) analysis shows that when the thickness of the Newtonian liquid layer exceeds approximately four penetration depths 4δ of the wave in a Newtonian liquid, then this Newtonian liquid layer can be regarded as a semi-infinite half-space. The results obtained in this paper can be important in the design and optimization of ultrasonic Love wave sensors such as: biosensors, chemosensors and viscosity sensors. Love wave viscosity sensors can be used to assess the viscosity of various liquids, e.g. liquid polymers.

Słowa kluczowe:
Love waves, ultrasonic sensors, Newtonian liquid, penetration depth, biosensors, chemosensors, viscosity sensors

(70p.)
69. Tasinkiewicz J., Trots I., Tymkiewicz R., Theoretical analysis and experimental verification of top orthogonal to bottom arrays of conducting strips on piezoelectric slab, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, DOI: 10.24425/aoa.2020.134059, Vol.45, No.3, pp.433-444, 2020

Streszczenie:
The purpose of this work is to present a theoretical analysis of top orthogonal to bottom arrays of conducting electrodes of infinitesimal thickness (conducting strips) residing on the opposite surfaces of piezoelectric slab. The components of electric field are expanded into double periodic Bloch series with corresponding amplitudes represented by Legendre polynomials, in the proposed semi-analytical model of the considered two-dimensional (2D) array of strips. The boundary and Edge conditions are satisfied directly by field representation, as a result. The method results in a small system of linear equations for unknown expansion coefficients to be solved numerically. A simple numerical example is given to illustrate the method. Also a test transducer was designed and a pilot experiment was carried out to illustrate the acoustic-wave generating capabilities of the proposed arrangement of top orthogonal to bottom arrays of conducting strips.

Słowa kluczowe:
boundary value problem, Fourier series, Bloch series, partial differential equations, piezoelectric transducer

(70p.)
70. Feng K., Akinoglu E.M., Bozheyev F., Guo L., Jin M., Wang X., Zhou G., Naughton M.J., Giersig M., Magnetron sputtered copper bismuth oxide photocathodes for solar water reduction, JOURNAL OF PHYSICS D-APPLIED PHYSICS, ISSN: 0022-3727, DOI: 10.1088/1361-6463/abaf25, Vol.53, pp.495501-1-11, 2020

Streszczenie:
There is an urgent need for new materials that can catalyze or drive the photoelectrochemical (PEC) conversion of solar energy into chemical energy, i.e. solar fuels. Copper bismuth oxide (CBO) is a promising photocathode material for the photochemical reduction of water. Here, we systematically control the stoichiometry of CBO thin films prepared by reactive, direct-current magnetron co-sputtering from metallic Bi and Cu targets. The intrinsic photophysical and PEC material properties are investigated and evaluated in order to determine the optimum composition for hydrogen formation. Changing the stoichiometry of the films reveals a dramatic change in the optical band gap and crystal structure of CBO. The largest photocurrent density was achieved for a copper-to-bismuth ion ratio of 0.53, close to the CuBi2O4 stoichiometry, which yielded Jph = − 0.48 mA cm^−2 at 0 VRHE (RHE = reversible hydrogen electrode). This is the highest value to date for the photochemical reduction of water with CuBi2O4 without an externally applied bias. The absorbed photon-to-current efficiency and the photostability of the films in neutral and alkaline electrolytes were also investigated.

Słowa kluczowe:
CuBi2O4, copper bismuth oxide, water reduction, water splitting, photocathode, magnetron sputtering

(70p.)
71. Zegarow P., Mańczak M., Rysz J., Olszewski R., The influence of cognitive-behavioral therapy on depression in dialysis patients - meta-analysis, Archives of Medical Science , ISSN: 1734-1922, DOI: 10.5114/aoms.2019.88019, Vol.16, No.6, pp.1271-1278, 2020

Streszczenie:
Introduction: Depressive disorders are the most common mental health problem among patients undergoing dialysis. Furthermore, depression is an independent factor increasing the mortality and frequency of hospitalization in this group of patients, yet psychological intervention programs aimed at improving the mental health of dialysis patients have still not been developed. This meta-analysis aimed to assess the effects of cognitive-behavioral therapy on depressive symptoms in dialysis patients. The main hypothesis of this study is that cognitive-behavioral therapy is an effective psychological method of reducing the severity of depression symptoms among patients undergoing dialysis. Material and methods: A systematic search was conducted using Medline, PubMed, Web of Science, Scopus and Google Scholar. Data extraction was carried out by two independent researchers. The severity of depression symptoms in the included studies was measured by the Beck Depression Inventory. A random-effects model was used to estimate the pooled mean difference of these values between patients undergoing CBT and the controls. Results: Four of the 1841 search results met the inclusion criteria with data from 226 patients who had undergone dialysis therapy due to renal disorders and psychological intervention based on cognitive-behavioral therapy. This therapy significantly reduced the level of depression symptoms in all studies included in the meta-analysis (mean difference = –5.3, p = 0.001; 95% CI: –7.95 to –2.66). Conclusions: The study showed that the use of psychological intervention based on cognitive-behavioral therapy was an effective method of decreasing the severity of depressive symptoms in hemodialyzed patients. For the sake of patient well-being, it seems reasonable to extend renal replacement therapy with psychological intervention such as cognitive-behavioral therapy.

Słowa kluczowe:
depression, dialysis, cognitive-behavioral therapy, renal replacement

(70p.)
72. Buda N., Kosiak W., Wełnicki M., Skoczylas A., Olszewski R., Piotrkowski J., Skoczyński Sz., Radzikowska E., Jassem E., Grabczak E.M., Kwaśniewicz P., Mathis G., Toma T.P., Recommendations for lung ultrasound in internal medicine, Diagnostics, ISSN: 2075-4418, DOI: 10.3390/diagnostics10080597, Vol.10, No.8, pp.597-1-25, 2020

Streszczenie:
Agrowing amount of evidence prompts us to update the first version of recommendations for lung ultrasound in internal medicine (POLLUS-IM) that was published in 2018. The recommendations were established in everal stages, consisting of: literature review, assessment of literature data quality (with the application of QUADAS, QUADAS-2 and GRADE criteria) and expert evaluation carried out consistently with the modified Delphi method (three rounds of on-line discussions, followed by a secret ballot by the panel of experts after each completed discussion). Publications to be analyzed were selected from the following databases: Pubmed, Medline, OVID, and Embase. New reports published as of October 2019 were added to the existing POLLUS-IM database used for the original publication of 2018. Altogether, 528 publications were systematically reviewed, including 253 new reports published between September 2017 and October 2019. The new recommendations concern the following conditions and issues: pneumonia, heart failure, monitoring dialyzed patients' hydration status, assessment of pleural effusion, pulmonary embolism and diaphragm function assessment. POLLUS-IM 2020 recommendations were established primarily for clinicians who utilize lung ultrasound in their everyday clinical work.

Słowa kluczowe:
lung ultrasound, chest ultrasound, internal medicine, recommendations

(70p.)
73. Obiała J., Obiała K., Mańczak M., Owoc J., Olszewski R., COVID-19 misinformation: accuracy of articles about coronavirus prevention mostly shared on social media, Health Policy and Technology, ISSN: 2211-8837, DOI: 10.1016/j.hlpt.2020.10.007, pp.1-5, 2020

Streszczenie:
Objective: To analyze accuracy of articles about COVID-19 prevention most frequently shared through social media platforms. Methods: Identifying, using the Buzzsumo analytic tool, 30 most frequently shared articles in April 2020 about COVID-19 prevention and classifying them according to number of shares, accuracy, topic and sharing platform. Calculations were made using descriptive statistics tools and chi-square test. Results: The top 30 articles about coronavirus prevention were shared 4904 160 times over a period of one month with 96.8% of all shares through Facebook. Most of the articles (80%) was found to be accurate, however they accounted for only 64% of shares. The inaccuracies referred mostly to handwashing. The most shared articles were about medications followed by masks and hand washing. Conclusions: Articles about coronavirus prevention are usually accurate, yet relatively less likely to be shared than inaccurate ones. Facebook remains a dominant social media platform for sharing content. Buzzsumo could be considered a tool in certain situations such as pandemic for health authorities to quickly investigate different health topics popular on social media. Lay Summary: Most of the articles about COVID-19 prevention, identified as most frequently shared through social media platform during the pandemic, was found to be accurate. However, inaccurate content was more likely to be shared than by Facebook users compared with accurate content. This suggests the need for health authorities to monitor content shared on social media in extraordinary situations such as pandemics.

Słowa kluczowe:
coronavirus, COVID-19, social media, misinformation, public health

(70p.)
74. Owoc J., Mańczak M., Jabłońska M., Tombarkiewicz M., Olszewski R., Association between physician burnout and self-reported errors: meta-analysis, Journal of Patient Safety, ISSN: 1549-8417, DOI: 10.1097/PTS.0000000000000724, pp.1-9, 2020

Streszczenie:
Objectives: Burnout among physicians is an increasingly recognized phenomenon affecting different aspects of patient care and safety. This meta-analysis quantifies association of burnout and its subscales with self-reported medical errors among physicians. Methods: This meta-analysis followed the principles formulated in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Meta-analyses of Observational Studies. The MEDLINE, PubMed, Web of Science, PsycInfo, and Eric databases were searched until February 5, 2019, using various combinations of key terms without any language restrictions: burnout, physicians, error, safety, and quality. Reference lists of selected studieswere hand searched. Datawere extracted frompublished reports. All quantitative studies reporting prevalence of burnout and its association with self-reported errors among physicians were considered. The analyses of heterogeneity (Cochran Q, I^2), publication bias (Begg- Mazumdar and Egger), three subgroups, and sensitivity were performed. The effect of overall burnout and Maslach Burnout Inventory subscales on self-reported errors was calculated as odds ratios with 95% confidence interval. Results: Thirteen studies on 20,643 physicians and residents were included. The overall burnout among participants was associated with a significantly increased risk of self-reported errors (odds ratio = 2.72, 95% confidence interval = 2.19–3.37). Emotional exhaustion, depersonalization, and personal accomplishment were all independently predicting factors of self-reported errors. Cochran Q test and inconsistency index I2 were as follows: Q = 27.2; P = 0.0013, I^2 = 67% (36%–83%). Conclusions: The results provide evidence that not only overall burnout but also its subscales independently are to be associated with a significantly increased risk of self-reported errors among physicians. As self-reported errors may translate into different types of adverse events, this strong and unequivocal association should be of major concern to healthcare organizations.

Słowa kluczowe:
burnout, error, patient safety, quality of care

(70p.)
75. Obiała K., Obiała J., Jeziorski K., Owoc J., Mańczak M., Olszewski R., Improving colon cancer prevention in Poland. A long way off, Journal of Cancer Education, ISSN: 0885-8195, DOI: 10.1007/s13187-020-01860-9, pp.1-4, 2020

Streszczenie:
The aim of this study was to analyse knowledge on colon cancer prevention among patients of primary care and identify their sources of information. The questionnaire study was conducted among patients of 36 primary healthcare clinics in Poland between September 2018 and February 2019. Patients were interviewed separately by trained researchers. Over 39% of the primary health patients declared that their knowledge about colon cancer prevention is unsatisfactory. Information about colon cancer prevention varied according to sex, age and BMI. Men declared lower level of knowledge than women: 46% of men thought it was unsatisfactory compared with 36%of women (p = 0.003). Preventive recommendations weremore often provided to patients over 60 years old (p < 0.01). Overweight and obese patients were more likely to receive recommendations on diet (p < 0.001) and physical activity (p < 0.001) than patients with normal weight. Themost common source of information on colon cancer prevention was Internet (68%) and medical doctors (60%). There is a need for developing colon cancer prevention policy. Crucial aspect includes educational programs aimed at improving patient’s knowledge and involving medical staff. The policymakers should pay greater attention to cancer prevention policies and medical staff involved in prevention to quality of communication to make sure patients thoroughly understand information they are provided.

Słowa kluczowe:
colon cancer, prevention, primary healthcare, education, communication

(70p.)
76. Garlinska M., Pręgowska A., Masztalerz K., Osial M., From mirrors to free-space optical communication-historical aspects in data transmission, Future Internet, ISSN: 1999-5903, DOI: 10.3390/fi12110179, Vol.12, No.11, pp.179-1-18, 2020

Streszczenie:
Fast communication is of high importance. Recently, increased data demand and crowded radio frequency spectrum have become crucial issues. Free-Space Optical Communication (FSOC) has diametrically changed the way people exchange information. As an alternative to wire communication systems, it allows efficient voice, video, and data transmission using a medium like air. Due to its large bandwidth, FSOC can be used in various applications and has therefore become an important part of our everyday life. The main advantages of FSOC are a high speed, cost savings, compact structures, low power, energy efficiency, a maximal transfer capacity, and applicability. The rapid development of the high-speed connection technology allows one to reduce the repair downtime and gives the ability to quickly establish a backup network in an emergency. Unfortunately, FSOC is susceptible to disruption due to atmospheric conditions or direct sunlight. Here, we briefly discuss Free-Space Optical Communication from mirrors and optical telegraphs to modern wireless systems and outline the future development directions of optical communication.

Słowa kluczowe:
free-space optical communication, telecommunications, wireless communication, data transfer history, communication networks

(40p.)
77. Kochańczyk M., Grabowski F., Lipniacki T., Dynamics of COVID-19 pandemic at constant and time-dependent contact rates, MATHEMATICAL MODELLING OF NATURAL PHENOMENA, ISSN: 0973-5348, DOI: 10.1051/mmnp/2020011, Vol.15, pp.28-1-12, 2020

Streszczenie:
We constructed a simple Susceptible−Exposed–Infectious–Removed model of the spread of COVID-19. The model is parametrised only by the average incubation period, τ, and two rate parameters: contact rate, β, and exclusion rate, γ. The rates depend on nontherapeutic interventions and determine the basic reproduction number, R0 = β/γ, and, together with τ, the daily multiplication coefficient in the early exponential phase, θ. Initial R0 determines the reduction of β required to contain the spread of the epidemic. We demonstrate that introduction of a cascade of multiple exposed states enables the model to reproduce the distributions of the incubation period and the serial interval reported by epidemiologists. Using the model, we consider a hypothetical scenario in which β is modulated solely by anticipated changes of social behaviours: first, β decreases in response to a surge of daily new cases, pressuring people to self-isolate, and then, over longer time scale, β increases as people gradually accept the risk. In this scenario, initial abrupt epidemic spread is followed by a plateau and slow regression, which, although economically and socially devastating, grants time to develop and deploy vaccine or at least limit daily cases to a manageable number.

Słowa kluczowe:
basic reproduction number, novel coronavirus

(40p.)
78. Volpert V., Banerjee M., D Onofrio, Lipniacki T., Petrovskii S., Tran V.C., Coronavirus - Scientific insights and societal aspects, MATHEMATICAL MODELLING OF NATURAL PHENOMENA, ISSN: 0973-5348, DOI: 10.1051/mmnp/2020010 , Vol.15, pp.E2-1-8, 2020

Streszczenie:
In December 2019, the first case of infection with a new virus COVID-19 (SARS-CoV-2), named coronavirus, was reported in the city of Wuhan, China. At that time, almost nobody paid any attention to it. The new pathogen, however, fast proved to be extremely infectious and dangerous, resulting in about 3–5% mortality. Over the few months that followed, coronavirus has spread over entire world. At the end of March, the total number of infections is fast approaching the psychological threshold of one million, resulting so far in tens of thousands of deaths. Due to the high number of lives already lost and the virus high potential for further spread, and due to its huge overall impact on the economies and societies, it is widely admitted that coronavirus poses the biggest challenge to the humanity after the second World war. The COVID-19 epidemic is provoking numerous questions at all levels. It also shows that modern society is extremely vulnerable and unprepared to such events. A wide scientific and public discussion becomes urgent. Some possible directions of this discussion are suggested in this article.

Słowa kluczowe:
COVID-19, epidemic progression, mathematical models, crisis management, open questions

(40p.)
79. Nowicki A., Safety of ultrasonic examinations; thermal and mechanical indices, Medical Ultrasonography, ISSN: 2066-8643, DOI: 10.11152/mu-3272, Vol.22, No.2, pp.203-210, 2020

Streszczenie:
This review article combines the reports on the biophysical effects in ultrasonography and provides the rationale behind the mechanical index (MI) and thermal index (TI) complying with the Output Display Standard (ODS). Safe ultrasonic doses are determined according to specific rules, and the screen displays the associated quantities MI and TI. The introduced indices MI and TI take into account the physical mechanism of interaction between ultrasounds and biological tissue, which depends on the temporal and spatial parameters of the acoustic field generated by ultrasound transducers. The predicted temperature increase is determined using three different tissue models: homogeneous, layered and bone/tissue interface.

Słowa kluczowe:
ultrasonography, thermal index, mechanical index, cavitation, international electrotechnical commission standards

(40p.)
80. Zawidzki M., The Overview of Optimization Methods Applied to Truss-Z Modular System, COMPUTER ASSISTED METHODS IN ENGINEERING AND SCIENCE, ISSN: 2299-3649, DOI: 10.24423/cames.291, Vol.27, No.2-3, pp.155-176, 2020

Streszczenie:
Extremely Modular Systems (EMSs) are comprised of as few types of modules as possible and allow creating structurally sound free-form structures that are not constrained by a regular tessellation of space. Truss-Z is the first EMS introduced, and its purpose is to create free-form pedestrian ramps and ramp networks in any given environment. This paper presents an overview of various multi-objective optimization methods applied to Truss-Z structures.

Słowa kluczowe:
Truss-Z, extremely modular system, discrete optimization, multi-objective

(20p.)
81. Proniewska K., Pręgowska A., Walecki P., Dołęga-Dołęgowski D., Ferrari R., Dudek D., Overview of the holographic-guided cardiovascular interventions and training - a perspective, Bio-Algorithms and Med-Systems, ISSN: 1895-9091, DOI: 10.1515/bams-2020-0043, Vol.16, No.3, pp.20200043-1-9, 2020

Streszczenie:
Immersive technologies, like Virtual Reality (VR), Augmented Reality (AR) and Mixed Reality (MR) have undergone technical evolutions over the last few decades. Their rapid development and dynamic changes enable their effective applications in medicine, in fields like imaging, preprocedural planning, treatment, operations planning, medical students training, and active support during therapeutic and rehabilitation procedures. Within this paper, a comprehensive analysis of VR/AR/MR application in the medical industry and education is presented. We overview and discuss our previous experience with AR/MR and 3D visual environment and MR-based imaging systems in cardiology and interventional cardiology. Our research shows that using immersive technologies users can not only visualize the heart and its structure but also obtain quantitative feedback on their location. The MR-based imaging system proposed offers better visualization to interventionists and potentially helps users understand complex operational cases. The results obtained suggest that technology using VR/AR/MR can be successfully used in the teaching process of future doctors, both in aspects related to anatomy and clinical classes. Moreover, the system proposed provides a unique opportunity to break the boundaries, interact in the learning process, and exchange experiences inside the medical community.

Słowa kluczowe:
augmented reality, improving the education process, interaction, intraprocedural visualization, mixed reality, preprocedural planning, teaching

(20p.)
82. Ahsani S., Boukadia R.F., Droz C., Zieliński T.G., Jankowski Ł., Claeys C., Desmet W., Deckers E., On the potential of meta-poro-elastic systems with small mass inclusions to achieve broad band a near-perfect absorption coefficient, ISMA2020 / USD2020, International Conference on Noise and Vibration Engineering / International Conference on Uncertainty in Structural Dynamics, 2020-09-07/09-09, Leuven (BE), pp.2463-2472, 2020

Streszczenie:
This paper discusses the potential of meta-poro-elastic systems with small mass inclusions to create broadband sound absorption performance under the quarter-wavelength limit. A first feasibility study is done to evaluate whether embedding small mass inclusions in specific types of foam can lead to near-perfect absorption at tuned frequencies. This paper includes an optimization routine to find the material properties that maximize the losses due to the mass inclusion such that a near-perfect/perfect absorption coefficient can be achieved at specified frequencies. The near-perfect absorption is due to the mass-spring effect, which leads to an increase in the viscous loss. Therefore, it is efficient in the viscous regime. The well-known critical frequency, which depends on the porosity and flow resistivity of the material, is commonly used as a criteria to distinguish the viscous regime from the inertial regime. However, for the types of foam of interest to this work, the value of critical frequency is below the mass-spring resonance frequency. Hence, the inverse quality factor is used to provides a more accurate estimation on the frequency at which the transition from the viscous regime to the inertial regime.

83. Zieliński T.G., Venegas R., A multi-scale calculation method for sound absorbing structures with localised micro-porosity, ISMA2020 / USD2020, International Conference on Noise and Vibration Engineering / International Conference on Uncertainty in Structural Dynamics, 2020-09-07/09-09, Leuven (BE), pp.395-407, 2020

Streszczenie:
This work presents a three-scale approach to modelling sound absorbing structures with non-uniform porosity, consisting of meso-patterns of localised micro-porosity. It can also be used for structures in which voids in a solid frame are filled with micro-fibres. The method involves double-scale, i.e. micro- and meso-scale, calculations of the effective properties of an equivalent homogenised medium, as well as macro-scale calculations of sound propagation and absorption in this medium, which at the macroscopic level can replace the entire absorbing structure of complex micro-geometry. The basic idea can be explained as follows: the mesoscale areas with localised micro-porosity are treated as homogenised meso-pores saturated with an equivalent visco-thermal fluid replacing the actual gas-saturated micro-porous medium, so that the macroscopic effective properties are finally calculated based on a simplified meso-scale geometry with homogenised mesopores.

84. Meissner M., Zieliński T.G., Low-frequency prediction of steady-state room response for different configurations of designed absorbing materials on room walls, ISMA2020 / USD2020, International Conference on Noise and Vibration Engineering / International Conference on Uncertainty in Structural Dynamics, 2020-09-07/09-09, Leuven (BE), pp.463-477, 2020

Streszczenie:
A technique commonly used for improving room acoustics consists in increasing a total sound damping in a room. This objective can be achieved by using different configurations of a porous material for acoustical treatment of a room. In this work, that problem is analyzed theoretically by exploiting a modal representation of the impulse response (IR) function for steady-state sound field predictions. A formula for the IR function was obtained by solving a wave equation for an enclosure with complex-valued boundary conditions of walls. On the walls where the acoustic treatment is applied, these boundary conditions are related to the characteristic impedance, effective speed of sound and thickness of the porous material used for padding. Two different porous materials were considered in the analyses of the room with acoustic treatment, and to this end, the required effective properties were calculated for a rigid foam with a designed periodic microstructure, as well as for a poroelastic foam with specific visco-elastic properties of the skeleton.

85. Opiela K.C., Zieliński T.G., Attenborough K., Manufacturing, modeling, and experimental verification of slitted sound absorbers, ISMA2020 / USD2020, International Conference on Noise and Vibration Engineering / International Conference on Uncertainty in Structural Dynamics, 2020-09-07/09-09, Leuven (BE), pp.409-420, 2020

Streszczenie:
Designs with uniformly distributed slits normal or inclined to the incident surface exhibit a great potential because of their simplicity and good acoustical performance. However, production of materials of this sort is challenging as the required fabrication precision is very high. This paper deals with additive manufacturing, modeling, and impedance tube testing of a few slitted geometries and their variations, including cases where the dividing walls between slits are perforated. They were designed to be producible with current 3D printing technology and provide reliable measurements using standardized equipment. The normal incidence sound absorption curves predicted analytically and numerically were verified experimentally. It is observed that such simple configurations may lead to absorption properties comparable to porous acoustic treatments with more complex microstructure. The good agreement between the predictions and measurements supports the validity of the multi-scale modeling employed.

86. Bartali R., Zhang G., Tong X., Speranza G., Micheli V., Gottardi G., Fedrizzi M., Pierini F., Sun S., Laidani N., Tavares A.C., Graphene oxide/reduced graphene oxide films as protective barriers on lead against differential aeration corrosion induced by water drops, Nanoscale Advances, ISSN: 2516-0230, DOI: 10.1039/d0na00212g, Vol.2, No.11, pp.5412-5420, 2020

Streszczenie:
Graphene-based materials have demonstrated high chemical stability and are very promising for protection against the corrosion of metal surfaces. For this reason, in this work, protective layers composed of graphene oxide, reduced graphene oxide and their mixtures were investigated, respectively, against the corrosion of the surface of lead induced by water drops. The materials were deposited on a Pb surface from their suspensions using a Meyer rod. The surface chemical composition, morphology and structure of the coatings were studied by X-ray photoemission spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM) and stylus profilometry. Moreover, a specific methodology based on the evolution of the water contact angle with time was used to evaluate the reactivity of the lead surface. The results show that the graphene-based materials can form an efficient barrier layer against the degradation of the Pb surface and that the degradation process induced by water is reduced by more than 70%. Moreover, unexpectedly, the best protective performance was obtained using graphene oxide as the coating.

(20p.)
87. Byra M., Styczyński G., Szmigielski C., Kalinowski P., Michałowski Ł., Paluszkiewicz R., Ziarkiewicz-Wróblewska B., Zieniewicz K., Nowicki A., Adversarial attacks on deep learning models for fatty liver disease classification by modification of ultrasound image reconstruction method, IUS 2020, IEEE International Ultrasonics Symposium, 2020-09-07/09-11, Las Vegas (US), DOI: 10.1109/IUS46767.2020.9251568, pp.1-4, 2020

Streszczenie:
Convolutional neural networks (CNNs) have achieved remarkable success in medical image analysis tasks. In ultrasound (US) imaging, CNNs have been applied to object classification, image reconstruction and tissue characterization. However, CNNs can be vulnerable to adversarial attacks, even small perturbations applied to input data may significantly affect model performance and result in wrong output. In this work, we devise a novel adversarial attack, specific to ultrasound (US) imaging. US images are reconstructed based on radio-frequency signals. Since the appearance of US images depends on the applied image reconstruction method, we explore the possibility of fooling deep learning model by perturbing US B-mode image reconstruction method. We apply zeroth order optimization to find small perturbations of image reconstruction parameters, related to attenuation compensation and amplitude compression, which can result in wrong output. We illustrate our approach using a deep learning model developed for fatty liver disease diagnosis, where the proposed adversarial attack achieved success rate of 48%.

Słowa kluczowe:
adversarial attacks, deep learning, fatty liver, transfer learning, ultrasound imaging

88. Guzman V.H., Cooper C., Poma Bernaola A., Quantifying the disassembly of viral capsids from a multiscale molecular simulation approach, APS MARCH MEETING 2020, AMERICAN PHYSICAL SOCIETY MARCH MEETING, 2020-03-02/03-06, Denver (US), No.65, pp.4501-4501, 2020

Streszczenie:
Molecular simulation of large biological systems, such as viral capsids, remains a challenging task in soft matter research. On one hand, coarse-grained (CG) models attempt to make feasible the description of the entire viral capsids. On the other hand, novel development of molecular dynamics (MD) simulation approaches, like enhance sampling which attempt to overcome the time scales required in biophysics. Those methods have a potential for delivering molecular structures and properties of biological systems. Nonetheless, exploring the process on how a capsid disassembles by all-atom MD simulations has been rarely attempted. Here, we propose a methodology to analyze the disassembly process of viral capsids quantitatively. In particular, we look at the effect of pH and charge of the genetic material inside the capsid, and compute the free energy of a disassembly trajectory by combining CG simulatiosn to a Poisson-Boltzmann solver. We employ such multiscale approach on the triatoma virus as a test case, and find that even though an alkaline environment enhances the stability of the capsid, the resulting deprotonation of the internal solvent generates an electrostatic repulsion that triggers disassembly.

Słowa kluczowe:
Poisson Boltzmann, free energy, viral capsid, molecular dynamics, multiscale simulation, coarse graining, pH, protein assemblies

89. Lewandowski M., Jarosik P., Tasinkevych Y., Walczak M., Efficient GPU implementation of 3D spectral domain synthetic aperture imaging, IUS 2020, IEEE International Ultrasonics Symposium, 2020-09-07/09-11, Las Vegas (US), DOI: 10.1109/IUS46767.2020.9251552, pp.1-3, 2020

Streszczenie:
In this work, we considered the implementation of a 3D volume reconstruction algorithm for single plane-wave ultrasound insonification. We review the theory behind the Hybrid Spectral-Domain Imaging (HSDI) algorithm, provide details of the algorithm implementation for Nvidia CUDA GPU cards, and discuss the performance evaluation results. The average time required to reconstruct a single data volume using our GPU implementation of the HSDI algorithm was 22 ms. We also present an iso-surface extraction result using a marching cubes algorithm. Our work constitutes a preliminary research for further development and implementation of 3D volume reconstruction using GPU implementation of the spectral domain imaging algorithm.

Słowa kluczowe:
ultrasound imaging, 3D ultrasound, volumetric imaging, gpu

90. Kukla D., Koper J., Methodology for quantitative assessment of basalt fibers obtained in continuous process, Composites Theory and Practice, ISSN: 2084-6096, Vol.20, No.2, pp.78-84, 2020

Streszczenie:
In 2019, the first basalt fiber production line was created in Poland. The fiber is produced in a continuous process, according to the technology developed by Polski Bazalt S.A. In order to assess the microstructure of the manufactured product, a number of tests were carried out, according to previously developed procedures. The presented results relate to the study of the basalt fiber microstructure using light microscopy, electron microscopy and atomic forces. The research was aimed at characterizing the fibers, but also developing research procedures that allow assessment of the basic fiber parameters under post-production conditions. The research was conducted in the field of quantitative and qualitative assessment of the basalt fiber microstructure, its diameter, and the size distribution of this value. In addition, attempts were made to assess the thickness of the sizing (as an impregnation layer) on the fibers obtained employing different parameters of the drawing process and various types of impregnation. Based on the obtained results, measurement and research procedures were implemented in the quality control system of the Polski Bazalt company. Tests carried out as part of these procedures confirm the repeatability in terms of the quality and diameter of the produced fiber.

Słowa kluczowe:
basalt fiber, microstructure, SEM, sizing thickness

(20p.)
91. Graczykowski C., Lewiński T., Applications of Michell's theory in designof high-rise buildings, large-scale roofs and long-span bridges, COMPUTER ASSISTED METHODS IN ENGINEERING AND SCIENCE, ISSN: 2299-3649, DOI: 10.24423/cames.288, Vol.27, No.2-3, pp.133-154, 2020

Streszczenie:
This paper analyzes the relations between the theory of Michell structures, which is one of the most important theories in structural optimization, and some remarkable engineering structures, including selected high-rise buildings, large-scale roof coverings and long-span bridges. The first part of this study briefly presents the development of Michell's theory, its basic concepts, assumptions, and examples and fundamental features of Michell structures. Then, several untypical engineering structures that make use of said concepts are presented, including skyscrapers proposed by the Polish structural designer W. Zalewski and the international architectural office of Skidmore, Owings and Merill (SOM). Next, large-scale roof coverings of "Spodek" arena in Poland as well as selected bridges are thoroughly analyzed in the context of similarity to Michell structures. The conducted study reveals that considered structural forms of the analyzed structures follow some of the concepts known from Michell's theory and thus possess many features of the optimal structural designs.

Słowa kluczowe:
topology optimization, Michell structures, high-rise buildings, large-scale roofs, long-span bridges

(20p.)
92. Kiełczyński P., Szalewski M., Balcerzak A., Wieja K., Anomalous behavior of ultrasonic Love waves propagating in two-layer waveguides loaded with a Newtonian liquid, IUS 2020, 2020 IEEE International Ultrasonics Symposium , 2020-09-08/09-11, Las Vegas (US), pp.1-1, 2020

Streszczenie:
Despite the fact that Love surface waves have been discovered initially in seismology, as the waves occurring in the wake of earthquakes, they found recently numerous application in a benign domain of biosensors and chemosensors, following the pioneering works of P. Kiełczyński et. al. (1987-1989). Regardless of the fact that Love waves have been discovered over one hundred years ago (1911), there are still many interesting, fundamental problems about Love waves theory, their connections to other wave motions, etc., which remain unsolved. In this work, we analyze theoretically the properties of Love surface waves propagating in waveguides consisting of two different surface layers (upper and lower) deposited on a semi-infinite substrate. The upper surface of the waveguide is additionally covered with a semi-infinite layer of a Newtonian liquid occupying the half-space. In fact, the configuration of the waveguide represents a typical structure of the Love wave sensor, working in a liquid environment. By varying the viscosity of the Newtonian liquid covering the upper surface the waveguide, the authors have discovered a number of new intriguing phenomena displaying abrupt changing in Love wave parameters. In particular, for some selected values of the liquid viscosity, e.g., for η=11.9 Pas we have observed: 1) a dramatic change in the Love wave attenuation (approximately 15 times) and 2) a drastic change in the distribution of the mechanical displacement as a function of depth, i.e., the distance from the upper waveguide surface. This is accompanied by a pronounced redistribution of the power flow of the Love wave, i.e., the maximum of the power flow switches from the upper surface layer to the lower surface layer. To best of our knowledge, the above phenomena have not yet been reported in the scientific literature. The obtained results can be crucial in the design of Love wave sensors, as well as in seismology.

Słowa kluczowe:
Love waves, viscoelastic liquids, layered waveguides, dispersion curves

93. Nasajpour A., Mostafavi A., Chlanda A., Rinoldi C., Sharifi S., Ji M.S., Ye M., Jonas S.J., Święszkowski W., Weiss P.S., Khademhosseini A., Tamayol A., Cholesteryl ester liquid crystal nanofibers for tissue engineering applications, ACS Materials Letters, ISSN: 2639-4979, DOI: 10.1021/acsmaterialslett.0c00224, Vol.2, No.9, pp.1067-1073, 2020

Streszczenie:
Liquid-crystal-based biomaterials provide promising platforms for the development of dynamic and responsive interfaces for tissue engineering. Cholesteryl ester liquid crystals (CLCs) are particularly well suited for these applications, due to their roles in cellular homeostasis and their intrinsic ability to organize into supramolecular helicoidal structures on the mesoscale. Here, we developed a nonwoven CLC electrospun scaffold by dispersing three cholesteryl ester-based mesogens within polycaprolactone (PCL). We tuned the ratio of our mesogens so that the CLC would be in the mesophase at the cell culture incubator temperature of 37°C. In these scaffolds, the PCL polymer provided an elastic bulk matrix while the homogeneously dispersed CLC established a viscoelastic fluidlike interface. Atomic force microscopy revealed that the 50% (w/v) cholesteryl ester liquid crystal scaffold (CLC-S) exhibited a mesophase with topographic striations typical of liquid crystals. Additionally, the CLC-S favorable wettability and ultrasoft fiber mechanics enhanced cellular attachment and proliferation. Increasing the CLC concentration within the composites enhanced myoblast adhesion strength promoted myofibril formationin vitrowith mouse myoblast cell lines.

(20p.)
94. Proniewska K., Pręgowska A., Dołęga-Dołegowski D., Chmiel J., Dudek D., Three-dimensional operating room with unlimited perspective, MCSS 2020, 10th International Conference on Multimedia Communications, Services and Security, 2020-10-08/10-09, Kraków (PL), DOI: 10.1007/978-3-030-59000-0_26, Vol.1284, pp.351-361, 2020

Streszczenie:
Apart fromoperating tables andmodern surgical instruments, themodern operating rooms are equipped with displays and video surveillance systems. The three-dimensional operating room allows users to watch medics perform surgery from different, individually chosen, points of view. For the first time, it is possible to reproduce/repeat the course of the operations and change the perspective or position, fromwhich it is observed. Here, we proposed a solution based on Microsoft HoloLens and Azure Kinect DK devices as remote support to patient management. The operating room is transferred to the digital form in real-time using Augmented Reality based technologies. Users can move around the digital place like a ghost in real space. The approach proposed allows users to see observe surgery from any point of view they want without disturbing the surgeon's workflow. They can change their positions, angle, and place of observation. All environmental restrictions disappear. The presented solution gives trainees a convenient opportunity to learn. It may make a significant contribution to improving the surgeontraining, patients' outcomes, and may allow virtual medical consultations during the surgery between specialists without them leaving their workplace.

Słowa kluczowe:
3D operating room, augmented reality, HoloLens

95. Psiuk R., Wiśniewska M., Garbiec D., Mościcki T., Spiekanie iskrowo-plazmowe SPS borków wolframu z dodatkiem cyrkonu / Spark plasma sintering of zirconium alloyed tungsten borides, III Ogólnopolskie Seminarium Spark Plasma Sintering III National Workshop on Spark Plasma Sintering, 2020-10-23/10-23, Kraków (PL), pp.25-26, 2020
96. Chojnacki A., Konowrocki R., Wysocki G., Longitudinal dynamics of freight trains - experimental and theoretical investigations, RAIL VEHICLES 2020 , The 24th scientific conference RAIL VEHICLES 2020 , 2020-10-25/10-28, Arłamów - Ustrzyki Dolne/ Poland (PL), No.1, pp.41-42, 2020

Streszczenie:
Safe operation and efficient of trains require assessment of its running behaviour. When freight rolling stock operators optimize their own costs and profits, one of many steps is to increase the number of wagons. As the freight trains become longer, the dynamics of individual freight wagons in the longitudinal direction becomes important in terms of in-service behaviour. In this case, the forces involved between the wagons have a key influence on safety against derailment. Safety against derailment is one of primary criteria for assessing the reliability of rail vehicle operation. The derailments of wagons of long freight trains frequently occurred around the world, which caused tremendous losses. Statistics from Australia, Canada, China revealed that the freight trains account for the vast majority of mainline derailments.

Słowa kluczowe:
longitudinal dynamics, freight trains, experimental and theoretical investigations, trains dynamics, wheel-rail interaction

97. Kalinowski D., Konowrocki R., Szolc T., Marczewski A., Simulation research on safety against derailment of trams with independently rotating wheels, RAIL VEHICLES 2020 , The 24th scientific conference RAIL VEHICLES 2020 , 2020-10-25/10-28, Arłamów - Ustrzyki Dolne/ Poland (PL), No.1, pp.81-82, 2020

Streszczenie:
Trams with independently rotating wheels (IRW) enable to increase a comfort of traveling by lowering the floor level along the entire length of the vehicle, in particular above the bogies. In these trams such solution imposes a different design of motor bogies. In this construction of the bogies, four independent motors mounted on the bogie frame are connected each by a gear-stage with a single running-wheel. By means of the appropriate control algorithm guiding driving torques in curved sections of the railway track can be generated. Trams must ensure a high level of safety of passengers, and one of its aspect is safety against derailment. This article presents an original simulation method to investigate a level of safety against derailment for such vehicles. Principles of this method are independent of the tram car configuration. Using this approach, structural analysis of trams was carried out, which tested drive control in the boogie equipped with independently rotating wheels. Here, numerous simulations of motion on curved tracks were performed by means of various wheel drive control algorithms.

Słowa kluczowe:
research safety, safety against derailment, derailment of trams, trams with independently rotating wheels, independently rotating wheels

98. Konowrocki R., Frischmut K., Analysis of acceleration signals measured obtained from a freight wagon in the various operation states, RAIL VEHICLES 2020 , The 24th scientific conference RAIL VEHICLES 2020 , 2020-10-25/10-28, Arłamów - Ustrzyki Dolne/ Poland (PL), No.1, pp.95-96, 2020

Streszczenie:
In the present paper, the authors try to find distinguishable characteristics based on acceleration data obtained from a railway car body. Those quantities allow constructing diagnostic maps, which in turn can be used to classify vehicles clearly as damaged or undamaged. In this approach, the assessment is based on measurements taken from both an undamaged and damaged rail vehicle. The data are compared by methods of artificial intelligence. The aim of this paper is to study aspects of a pure signal-based approach to the end of a quick recognition of damage by assessment of selected parameters of sensor data in real time.

Słowa kluczowe:
analysis of measured signals, experimental investigations, artificial intelligence, railway wagon, quick recognition of damage, damage diagnostic, neural networks

99. Szolc T., Pochanke A., Konowrocki R., Pisarski D., Suppression and control of torsional vibrations of the turbo-generator shaft-lines using rotary magneto-rheological dampers, VIRM, 12th International Conference on Vibrations in Rotating Machinery, 2020-01-14/01-15, London (GB), No.1, pp.90-90, 2020

Streszczenie:
Torsional vibrations of steam turbo-generator rotor-shaft-lines coupled with bending vibrations of exhaust blades still constitute an important operational problem for this type of rotor-machines. Therefore, this work proposes a relatively simple approach for efficient suppression and control of transient and steady-state turbo-generator-shaft torsional vibrations excited by short circuits in a generator or power-lines, faulty synchronization, negative sequence currents and by sub-synchronous resonances in the turbo-generator-electric network system. This target has been achieved by means of semi-actively controlled rotary dampers with the magneto-rheological fluid. Regular operation of such devices installed in a given turbo-generator rotor-shaft-line enables suppression of dangerous torsional oscillations.

Słowa kluczowe:
control of torsional vibrations, turbo-generator, shaft-lines vibrations, rotary magneto-rheological dampers, new rotary dampers

100. Wiszowaty R., Faraj R., Graczykowski C., Mikułowski G., Study on practical implementation of the self-adaptive impact absorber, ISMA2020 / USD2020, International Conference on Noise and Vibration Engineering / International Conference on Uncertainty in Structural Dynamics, 2020-09-07/09-09, Leuven (BE), pp.779-792, 2020

Streszczenie:
The discussed study is focused on implementation of a novel kinematics-based control technique. Presented results are based on theoretical and numerical analyses as well as on experimental investigations, which are focused on elaboration of the efficient self-adaptive energy absorption system. The developed control method has been originally dedicated to the impact mitigation problem, but it can be adjusted to other types of dynamic excitations. Superior performance of the method results from the fact that proposed system adapts automatically to unidentified dynamic excitations and compensates possible unexpected disturbances during the impact absorption process. The analyzed self-adaptive impact absorption system is based on the pneumatic shock-absorber with piezoelectric valve and real-time control system. This contribution is focused on chosen factors which can lead to undesired imperfections in practical implementation of the control method.

101. Faraj R., Popławski B., Hinc K., Preliminary study on modelling and optimization of the rescue cushion system, ISMA2020 / USD2020, International Conference on Noise and Vibration Engineering / International Conference on Uncertainty in Structural Dynamics, 2020-09-07/09-09, Leuven (BE), pp.2675-2684, 2020

Streszczenie:
The paper is aimed at modelling and optimization of a rescue cushion system, which is a device used by fire brigades for evacuation of people from buildings. The goal of the study is an improvement of the system response under various operational conditions. For faster and cheaper analysis of the system performance and further development of the complex structure of the rescue cushion system, a dedicated dynamical model is elaborated. Implemented numerical model is further applied for the parametric study in order to evaluate the influence of selected airbag parameters on the effectiveness of impact mitigation process and to determine possible improvements of the actual system design. In particular, adaptation of the rescue cushion to the mass of landing person, as well as to the initial velocity, is analyzed. Simultaneously, the necessity of meeting all the functional and operational requirements is taken into account. The most promising directions of further research are indicated.

102. Golasiński K., Pieczyska E.A., Maj M., Staszczak M., Furuta T., Kuramoto S., Takesue N., Analysis of temperature changes of a Ti-based alloy gum metal under selected loadings in the context of its unconventional deformation mechanisms, 8th Wdzydzeanum Workshop on „FLUID – SOLID INTERACTION”, 2020-08-30/09-03, Wdzydze Kiszewskie (PL), pp.1-1, 2020
103. Zaszczyńska A., Cieciuch A., Gradys A., Lewandowska-Szumieł M., Sajkiewicz P., Cellular studies on stromal cells and piezoelectric nanofibers subjected to ultrasounds stimulations for medical devices, UK-Poland Bioinspired Materials Conference, 2020-11-23/11-24, Lancaster (GB), pp.127-127, 2020
104. Graczykowski C., Faraj R., Optimal control of semi-active shock-absorbers subjected to dynamic excitation using Pontryagin's maximum principle, gradient-based methods and direct methods, EURODYN 2020, XI International Conference on Structural Dynamics, 2020-11-23/11-26, Ateny (GR), pp.1-1, 2020

Streszczenie:
The current progress in the field of sensors and actuators has triggered increasing application of semi-active shock-absorbers for mitigation of dynamic excitations in car suspensions, aircrafts landing gears and buildings seismic protection systems [1]. The problems related to design of semi-active shock-absorbers include not only their proper construction providing reliable operation, but also elaboration of control strategies ensuring optimal mitigation of dynamic excitations of various kinds [2,3]. Development of optimal control strategies is especially difficult because of limitations of applied actuators, e.g. their finite stroke and speed, which are often critical for system operation and strongly influence efficiency of the shock-absorbing device. The contribution concerns the fundamental problem of mitigation of the rigid object’s impact using fluid-based shock-absorber equipped with a controllable valve with predefined performance limitations. The problem of impact mitigation is formulated as optimal control problem aimed at dissipation of the entire impact energy and minimization of the global deviation of generated force and corresponding impacting object's deceleration from the theoretical optimal values [4]. The considered limitations of valve operation cause that solution of the control problem is no longer intuitive and sophisticated mathematical tools have to be applied. First, the application of Pontryagin's maximum principle to impact mitigation problem is analyzed and the difficulties in obtaining final solution are discussed. Secondly, the possibilities of solving the problem using gradient-based methods of variational calculus are considered and the influence of initially assumed control scenario is investigated. Eventually, the solution of impact mitigation problem is obtained using direct methods with various discretization and schemes of numerical integration. The
obtained solutions are thoroughly analyzed and compared against each other, which allows to draw general conclusions about application of optimal control methods for semi-active shock-absorbers subjected to impact loads and to evaluate the influence of valves limitations on the efficiency of impact absorption process.

105. Faraj R., Hinc K., Popławski B., Gabryel D., Kowalski T., Graczykowski C., Preliminary study on adaptive techniques for novel type of the rescue cushion, EURODYN 2020, XI International Conference on Structural Dynamics, 2020-11-23/11-26, Ateny (GR), pp.1-1, 2020

Streszczenie:
Despite the fact that airbag systems are well-known and used in safety engineering for many years the growth of research and development activities and increasing number of new applications of airbags are observed. Advances in the field includes among others: development of advanced car airbags, analyses of airbag cushioning for landing on Mars, elaboration of emergency landing system for drones. Another field of airbags application and simultaneously the main motivation for the study presented in the paper is the evacuation of people conducted by the fire brigade. When people are forced to leave the building by jump from the window or roof the rescue cushion is placed on the ground in order to mitigate the impact and safe life of evacuated people. The aim of the study is to develop the relevant adaptation strategy for the system and provide efficient operation of the airbag in case of different impact velocities and different masses of the landing person. Several approaches to the system adaptation are analyzed and they include semi-active as well as semi-passive solutions. Also possibility of implementing the concept of self-adaptive impact absorption is assessed. Technical and operational requirements for the rescue cushion are considered and based on them the final adaptation principles are selected. Evaluation of the system performance is conducted with the use of numerical models of dummies provided in the LS Dyna software environment. In Fig. 1. the overloads acting on pelvis of three different dummies dropped from assumed height are shown. The obtained mitigation of the impact loading is significant for all considered cases.

106. Pęcherski R.B., A new look at viscoplasticity generated by shear banding, 8th Wdzydzeanum Workshop on „FLUID – SOLID INTERACTION”, 2020-08-30/09-03, Wdzydze Kiszewskie (PL), pp.1-2, 2020
107. Nowak Z., Pęcherski R.B., Constitutive modelling of shear bands effect in ductile materials: formulation and computational aspects, 8th Wdzydzeanum Workshop on „FLUID – SOLID INTERACTION”, 2020-08-30/09-03, Wdzydze Kiszewskie (PL), pp.1-2, 2020
108. Hołobut P., Bordas S.P.A., Lengiewicz J., Autonomous model-based assessment of mechanical failures of reconfigurable modular robots with a conjugate gradient solver, IROS, International Conference on Intelligent Robots and Systems, 2020-10-25/10-29, Las Vegas (US), pp.11696-11702, 2020

Streszczenie:
Large-scale 3D autonomous self-reconfigurable modular robots are made of numerous interconnected robotic modules that operate in a close packing. The modules are assumed to have their own CPU and memory, and are only able to communicate with their direct neighbors. As such, the robots embody a special computing architecture: a distributed memory and distributed CPU system with a local messagepassing interface. The modules can move and rearrange themselves changing the robot's connection topology. This may potentially cause mechanical failures (e.g., overloading of some inter-modular connections), which are irreversible and need to be detected in advance. In the present contribution, we further develop the idea of performing model-based detection of mechanical failures, posed in the form of balance equations solved by the modular robot itself in a distributed manner. A special implementation of the Conjugate Gradient iterative solution method is proposed and shown to greatly reduce the required number of iterations compared with the weighted Jacobi method used previously. The algorithm is verified in a virtual test bed—the VisibleSim emulator of the modular robot. The assessments of time-, CPU-, communication- and memory complexities of the proposed scheme are provided.

109. Sadowski T., Pietras D., Postek E., Experimental testing and of modelling of gradual degradation of Al2O3/ZrO2 ceramic composite under slow and high strain rates, ICCS23, ICCS23 - 23rd International Conference on Composite Structures & MECHCOMP6 - 6th International Conference on Mechanics of Composites, 2020-09-01/09-04, Porto (PT), pp.143-143, 2020

Streszczenie:
Gradual degradation of brittle composites exhibits different mechanical response under uniaxial tension and uniaxial compression. In this paper, we analysed cracking processes and failure under quasi-static loading of 2 phase ceramic material made of Al2O3 and ZrO2 mixture, subjected to tension and compression. Constitutive modelling of two-phase ceramic composites obeys description of (1) elastic deformations of initially porous material, (2) limited plasticity and (3) cracks initiation and propagation. Modelling of polycrystalline ceramics at the mesoscopic level under mechanical loading is related to the analysis of a set of grains, i.e. Representative Volume Element (RVE). The basic elements of the defect structure inside polycrystal are micro-cracks and meso-cracks, kinked and wing cracks. To get a macroscopic response of the material one can calculate averaged values of stress and strain over the RSE with an application of the analytical approach. High strain rate degradation process was illustrated for Al2O3/ZrO2 composite, which was subjected to short compressive impulse. The pulse duration was 10-7s. In the proposed more advanced finite elements formulation it was necessary to take into account the following data and phenomena appearing inside of the RVE: (1) spatial distribution of the composite constituents, (2) system of grain boundaries/binder interfaces modelled by interface elements, (3) rotation of brittle grains. The numerical model of gradual degradation of the Al2O3//ZrO2 composite response due to pulse compressive loading presents correctness and capability of the proposed FEM approach.

Słowa kluczowe:
brittle composites, representative volume element, degradation, damage, peridynamics

110. Jeznach O., Kołbuk D., Sajkiewicz P., Surface modification of polymer fibers based on aminolysis and gelatin immobilization as a method of improvement of cell-scaffold interaction, UK-Poland Bioinspired Materials Conference, 2020-11-23/11-24, Lancaster (GB), pp.77, 2020
111. Parol M.A., Majka K., Trawiński Z., Gambin B., Krupienicz A., Obiala J., Nowicki A., Olszewski R., Ultrasonic imaging of radial artery reactive response in patients with hypertension with and without left ventricular hypertrophy, EuroEcho 2019, EuroEcho 2019 Congress of the European Association of Cardiovascular Imaging (EACVI). , 2019-12-04/12-07, Vienna (AT), DOI: 10.1093/ehjci/jez319.1176, Vol.21, No.Suplement 1, pp.i1239-i1239, 2020
112. Pierini F., Nakielski P., Pawłowska S., Rinoldi C., Ziai Y., Urbanek-Świderska O., De Sio L., Calogero A., Lanzi M., Zembrzycki K., Pruchniewski M., Salatelli E., Kowalewski T.A., Yarin A., Nature-inspired smart drug delivery platforms based on electrospun nanofibers and plasmonic hydrogels for near-infrared light-controlled polytherapy, Polymer Connect, Polymer Science and Composite Materials Conference, 2020-02-26/02-28, LISBON (PT), pp.7-7, 2020
113. Kopeć M., Wang K., Yuan X., Wang L., Kowalewski Z.L., Fast light alloys stamping technology (FAST) for two-phase titanium alloys, PGEM, The Sixth Postgraduate Experimental Mechanics Conference, 2020-12-03/12-04, Manchester (GB), pp.1-1, 2020
114. Kopeć M., Innowacyjna metoda formowania na gorąco stopów tytanu, wiWAT, VIII Konferencja Młodych Naukowców „Wiedza i Innowacje – wiWAT 2020”, 2020-12-01/12-03, Warszawa (PL), pp.1-1, 2020
115. Ekiel-Jeżewska M.L., Żuk P.J., Słowicka A.M., Stone H.A., Bending of elastic fibers in shear flow, BULLETIN OF THE AMERICAN PHYSICAL SOCIETY, ISSN: 0003-0503, Vol.65, pp.Y06.4, 2020
116. Trombley C.I., Ekiel-Jeżewska M.L., Mutual capture of two charged particles settling under gravity in a viscous fluid, BULLETIN OF THE AMERICAN PHYSICAL SOCIETY, ISSN: 0003-0503, Vol.65, pp.W13.9, 2020
117. Wojnar R., Helisy i piezoelektryczność, XII Interdyscyplinarna Konferencja Naukowa TYGIEL 2020. Interdyscyplinarność kluczem do rozwoju., 2020-09-24/09-27, Lublin (PL), pp.89-89, 2020
118. Wojnar R., Rozkład Bosego-Einsteina i prawo Pareta, XII Interdyscyplinarna Konferencja Naukowa TYGIEL 2020. Interdyscyplinarność kluczem do rozwoju., 2020-09-24/09-27, Lublin (PL), pp.225-225, 2020
119. Lewandowska-Gruszka B., Dane i metadane. Z zagadnień zarządzania informacją cyfrową, Zarządzanie informacją w nauce, 2020-11-27/11-27, Kraków, Uniwersytet Jagielloński (PL), pp.1-1, 2020

Streszczenie:
W obszarze badań naukowych informacja jest wykorzystywana jako źródło informacji o istniejących obiektach. Informacja ma zatem podstawowe znaczenie w zakresie powstawanie wiedzy, składając się w istotny sposób na tworzenie przekazów wiedzy – opisów doświadczeń empirycznych, narracji, pojęć, koncepcji, definicji, twierdzeń, aksjomatów. Jednocześnie problematyczne jest definiowanie informacji z powodu braku określenia specyfiki jej natury. Twórca pierwszej koncepcji naukowej z zakresu cybernetyki, Norbert Wiener, przyjmował pojęcie informacji jako trzeciego elementu, obok masy i energii, niezbędnego do opisu świata fizycznego. Zgodnie z przyjętą przeze mnie koncepcją, stosuję termin informacja w znaczeniu źródła danych o obiektach, gdzie dane te mogą być połączone w kolekcje. Dane to sposób reprezentacji informacji w sposób sformalizowany, a przez to umożliwiający jej komunikowanie, interpretowanie, przechowywanie w pamięci, jak również jej przetwarzanie. Przy wykorzystaniu danych możliwe jest zgromadzenie, przechowywanie i zarządzanie wiedzą z zakresu naszego obszaru poznawczego i przedstawienie jej również w formie informacji cyfrowej. W swej większości dane są strukturami złożonymi. Do zarządzania danymi wykorzystywane są metadane, które są sformułowane w przyjętym standardzie metadanych, i są interpretowane przez system informacyjny. Metadane mogą być również integralną częścią obiektów, które opisują. Do gromadzenia metadanych służą repozytoria metadanych. W rezultacie wprowadzonej standaryzacji metadanych, mogą one zostać wykorzystane do modelowania danych również z obszaru nauki. Standaryzacja metadanych umożliwia maszynom inteligentnym pobranie metadanych i poddanie ich przetwarzaniu – w wyniku implementacji określonej standaryzacji metadanych, również dane zasilają różne systemy informacyjne, zwiększając tym samym zakres i zasięg wykorzystania danych.

Słowa kluczowe:
informatologia, informacja, dane, metadane, zarządzanie informacją

120. Wojnar R., Moments of the Van Hove dynamic scattering law, Symposium on Statistical Physics, 2020-12-03/12-04, Kraków (PL), pp.64-64, 2020
121. Wojnar R., Kapsydy wirusów jako wielościany, XII Interdyscyplinarna Konferencja Naukowa TYGIEL 2020. Interdyscyplinarność kluczem do rozwoju., 2020-09-24/09-27, Lublin (PL), pp.60-60, 2020
122. Ekiel-Jeżewska M., Młodzież szkolna i nauczyciele z wizytą w instytucie naukowym, PAUZA AKADEMICKA, ISSN: 1689-488X, Vol.503, pp.3-3, 2020
123. Jeznach O., Kołbuk D., Sajkiewicz P., Impact of surface modification on polyester nanofibers properties and scaffold-cells interaction, WBC2020, 11th World Biomaterials Congress, 2020-12-11/12-15, online (GB), pp.1-2, 2020

Słowa kluczowe:
coatings, fibre-based biomaterials incl. electrospinning, material/tissue interfaces

124. Zieliński T.G., Galland M.-A., Analysis of wave propagation and absorption at normal and oblique incidence in poroelastic layers with active periodic inclusions, e-FA2020, e-FORUM ACUSTICUM 2020, 2020-12-07/12-11, Lyon (FR), pp.2431-2437, 2020

Streszczenie:
The paper presents numerical studies of wave propagation under normal and oblique incidence in sound-absorbing layers of poroelastic composites with active and passive inclusions embedded periodically along the composite layer surface. The purpose of active inclusions is to increase the mass-spring effect of passive inclusions attached to the viscoelastic skeleton of the poroelastic matrix of the composite in order to increase the dissipation of the energy of acoustic waves penetrating into such a layer of poroelastic composite. Finite element modelling is applied which includes the coupled models of Biot-Allard poroelasticity (for the poroelastic matrix), piezoelectricity and elastodynamics (for the active and passive inclusions, respectively), as well as the Helmholtz equation for the adjacent layer of air. The formulation based on the Floquet-Bloch theory is applied to allow for modelling of wave propagation at oblique incidence to the surface of the periodic composite layer. The actively exited piezoelectric inclusions may become additional (though secondary) sources for wave propagation. Therefore, a background pressure field in a wide adjacent air layer is used to simulate plane waves propagating from the specified direction, oblique or normal, onto the poroelastic layer surface, and a nonreflecting condition is applied on the external boundary of the air layer.

125. Opiela K.C., Zieliński T.G., Dvorák T., Kúdela Jr S., Perforated closed-cell metal foam for acoustic applications, e-FA2020, e-FORUM ACUSTICUM 2020, 2020-12-07/12-11, Lyon (FR), pp.2565-2572, 2020

Streszczenie:
Despite very good mechanical and physical properties such as lightness, rigidity and high thermal conductivity, closed-porosity metal foams alone are usually poor acoustic treatments. However, relatively low production cost weighs them in many applications in favour of their open-cell equivalents. In the present paper, this attractive and popular material is subject to consideration from the point of view of the improvement of its sound absorption characteristics. A classic method of perforation is proposed to open the porous interior of the medium to the penetration of acoustic waves and therefore enhance the dissipation of their energy. The interaction between the perforation diameter and closed-cell microstructure as well as its impact on the overall sound absorption of a similar foam were already studied in 2010 by Chevillotte, Perrot and Panneton, so these topics are not discussed much in this work. On the other hand, the objective here is to investigate if one can efficiently approximate the wave propagation phenomenon in real perforated heterogeneous materials with closed porosity of irregular shape by means of their simplified three-dimensional representation at the micro-level. The applied multi-scale modelling of sound absorption was confronted with measurements performed in an impedance tube. Moreover, as expected, numerical and experimental comparisons with relevant perforated solid samples show great benefit coming from the presence of a porous structure in the foam, although it was initially closed.

126. Koza P., Beroun A., Konopka A., Górkiewicz T., Bijoch Ł., Torres J.C., Bulska E., Knapska E., Kaczmarek L., Konopka W., Neuronal TDP-43 depletion affects activity-dependent plasticity, Neurobiology of Disease, ISSN: 0969-9961, DOI: 10.1016/j.nbd.2019.104499, Vol.130, pp.104499-1-12, 2019

Streszczenie:
TAR DNA-binding protein 43 (TDP-43) is a hallmark of some neurodegenerative disorders, such as frontotemporal lobar degeneration and amyotrophic lateral sclerosis. TDP-43-related pathology is characterized by its abnormally phosphorylated and ubiquitinated aggregates. It is involved in many aspects of RNA processing, including mRNA splicing, transport, and translation. However, its exact physiological function and role in mechanisms that lead to neuronal degeneration remain elusive. Transgenic rats that were characterized by TDP-43 depletion in neurons exhibited enhancement of the acquisition of fear memory. At the cellular level, TDP-43-depleted neurons exhibited a decrease in the short-term plasticity of intrinsic neuronal excitability. The induction of long-term potentiation in the CA3-CA1 areas of the hippocampus resulted in more stable synaptic enhancement. At the molecular level, the protein levels of an unedited (R) FLOP variant of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) GluR1 and GluR2/3 subunits decreased in the hippocampus. Alterations of FLOP/FLIP subunit composition affected AMPAR kinetics, reflected by cyclothiazide-dependent slowing of the decay time of AMPAR-mediated miniature excitatory postsynaptic currents. These findings suggest that TDP-43 may regulate activity-dependent neuronal plasticity, possibly by regulating the splicing of genes that are responsible for fast synaptic transmission and membrane potential.

Słowa kluczowe:
TDP-43, AMPA receptors, FLOP/FLIP splice variants, PTZ model

(100p.)
127. Lewandowska-Gruszka B., Lewandowski J., Organizacja informacji w środowisku cyfrowym. Przykład bibliotek cyfrowych, XV Krajowe Forum INT, XV Krajowe Forum Informacji Naukowej i Technicznej, Informacja - Wiedza - Innowacje w europejskiej przestrzeni badawczej, 2019-09-18/09-19, Kraków (PL), pp.1-1, 2019
128. Was H., Barszcz K., Czarnecka J., Kowalczyk A., Bernas T., Uzarowska E., Koza P., Klejman A., Piwocka K., Kaminska B., Sikora E., Bafilomycin A1 triggers proliferative potential of senescent cancer cells in vitro and in NOD/SCID mice, Oncotarget, ISSN: 1949-2553, DOI: 10.18632/oncotarget.14066, Vol.8, No.6, pp.9303-9322, 2017

Streszczenie:
Anticancer therapies that induce DNA damage tend to trigger senescence in cancer cells, a process known as therapy-induced senescence (TIS). Such cells may undergo atypical divisions, thus contributing to tumor re-growth. Accumulation of senescent cancer cells reduces survival of patients after chemotherapy. As senescence interplays with autophagy, a dynamic recycling process, we sought to study whether inhibition of autophagy interferes with divisions of TIS cells. We exposed human colon cancer HCT116 cells to repeated cycles of a chemotherapeutic agent - doxorubicin (doxo) and demonstrated induction of hallmarks of TIS (e.g. growth arrest, hypertrophy, poliploidization and secretory phenotype) and certain properties of cancer stem cells (increased NANOG expression, percentages of CD24+ cells and side population). Colonies of small and highly proliferative progeny appeared shortly after drug removal. Treatment with bafilomycin A1 (BAF A1), an autophagy inhibitor, postponed short term in vitro cell re-population. It was associated with reduction in the number of diploid and increase in the number of poliploid cells. In a long term, a pulse of BAF A1 resulted in reactivation of autophagy in a subpopulation of HCT116 cells and increased proliferation. Accordingly, the senescent HCT116 cells treated with BAF A1 when injected into NOD/SCID mice formed tumors, in contrast to the controls. Our results suggest that senescent cancer cells that appear during therapy, can be considered as dormant cells that contribute to cancer re-growth, when chemotherapeutic treatment is stopped. These data unveil new mechanisms of TIS-related cancer maintenance and re-population, triggered by a single pulse of BAF A1 treatment.

Słowa kluczowe:
colon cancer, chemotherapy, senescence, autophagy, angiogenesis

(40p.)
129. Stefaniuk M., Gualda E.J., Pawlowska M., Legutko D., Matryba P., Koza P., Konopka W., Owczarek D., Wawrzyniak M., Loza-Alvarez P., Kaczmarek L., Light-sheet microscopy imaging of a whole cleared rat brain with Thy1-GFP transgene, Scientific Reports, ISSN: 2045-2322, DOI: 10.1038/srep28209, Vol.6, pp.28209-1-9, 2016

Streszczenie:
Whole-brain imaging with light-sheet fluorescence microscopy and optically cleared tissue is a new, rapidly developing research field. Whereas successful attempts to clear and image mouse brain have been reported, a similar result for rats has proven difficult to achieve. Herein, we report on creating novel transgenic rat harboring fluorescent reporter GFP under control of neuronal gene promoter. We then present data on clearing the rat brain, showing that FluoClearBABB was found superior over passive CLARITY and CUBIC methods. Finally, we demonstrate efficient imaging of the rat brain using light-sheet fluorescence microscopy.

(40p.)
130. Wiera G., Szczot M., Wojtowicz T., Lebida K., Koza P., Mozrzymas J.W., Impact of matrix metalloproteinase-9 overexpression on synaptic excitatory transmission and its plasticity in rat CA3-CA1 hippocampal pathway, JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY, ISSN: 0867-5910, Vol.66, No.2, pp.309-315, 2015

Streszczenie:
Metalloproteinases (MMPs) have been shown to play a crucial role in synaptic plasticity and cognitive processes. We recently reported that in the mossy fiber - CA3 hippocampal pathway, LTP maintenance required fine-tuned MMP-9 activity, as both MMP-9 excess and absence impaired LTP. Here we used acute brain slices from transgenic (TG) rats overexpressing MMP-9 to investigate the impact of excessive MMP-9 activity on the excitatory synaptic transmission in the CA3-CA1 projection. Using field potential recordings, we have demonstrated that MMP-9 overexpression increased the strength of basal synaptic transmission but had no effect on the short-term plasticity in comparison to the wild-type (WT) group. In attempt to shed light on mechanisms underlying this observation, miniature excitatory postsynaptic potentials (mEPSCs) were recorded from pyramidal CA1 neurons. We found that mEPSCs in the TG group had a significantly slower decaying phase than in WT but amplitudes and frequencies were similar. The lack of differences in mEPSC frequency and short-term plasticity between TG and WT groups suggests that MMP-9 overexpression effect on fEPSPs was mainly postsynaptic. Additionally, we have found that excess of MMP-9 in TG rats was associated with impaired late-phase of LTP in the considered pathway. It seems thus that augmented synaptic strength in TG rats occurred in expense of impaired long-term plasticity induced by tetanization. In conclusion, overexpression of MMP-9 leads to increase in the strength of basal excitatory synaptic transmission and impairs of LTP maintenance phase in the CA3-CA1 pathway in vitro.

Słowa kluczowe:
hippocampus, metalloproteinase, high frequency stimulation, long-term potentiation, miniature excitatory postsynaptic potentials, field excitatory postsynaptic potentials, synapse

(25p.)
131. Szczytko J., Vaupotic N., Madrak K., Sznajder P., Górecka E., Magnetic moment of a single metal nanoparticle determined from the Faraday effect, PHYSICAL REVIEW E, ISSN: 1539-3755, DOI: 10.1103/PhysRevE.87.033201, Vol.87, No.3, pp.033201-1-6, 2013

Streszczenie:
Optical properties of a composite material made of ferromagnetic metal nanoparticles embedded in a dielectric host are studied. We constructed an effective dielectric tensor of the composite material taking into account the orientational distribution of nanoparticle magnetic moments in external magnetic field. A nonlinear dependence of the optical rotation on magnetic field resulting from the reorientation of nanoparticles is demonstrated. The theoretical findings were applied to the magneto-optical experimental data of cobalt ferromagnetic nanoparticles embedded in a dielectric liquid host. The dependence of the Faraday rotation on Co-based ferromagnetic nanoparticles was measured as a function of the external magnetic field, varying the size of nanoparticles and the wavelength of light. The proposed approach enables quantitative determination of the magnetic moment and the plasma frequency of a single nanoparticle, and from this the size of the nonmagnetic shell of magnetic nanoparticles.

(35p.)
132. Serafin K., Oracz J., Grzybowski M., Koperski M., Sznajder P., Zinkiewicz Ł., Wasylczyk P., Measurement of the mass of an object hanging from a spring-revisited, European Journal of Physics, ISSN: 0143-0807, DOI: 10.1088/0143-0807/33/1/011, Vol.33, pp.129-134, 2012

Streszczenie:
In an open competition, students were to determine the mass of a metal cylinder hanging on a spring inside a transparent enclosure. With the time for experiments limited to 24 h due to the unexpectedly large number of participants, a few surprisingly accurate results were submitted, the best of them differing by no more than 0.5% from the true value with a relative uncertainty of less than 1%.

(20p.)
133. Sznajder P., Piętka B., Szczytko J., Łusakowski J., Bardyszewski W., Resonant plasmon response of a periodically modulated two-dimensional electron gas, ACTA PHYSICA POLONICA A, ISSN: 0587-4246, DOI: 10.12693/APhysPolA.122.1090, Vol.122, No.6, pp.1090-1092, 2012

Streszczenie:
We report the theoretical study of the optical response of a periodically modulated two-dimensional electron gas. The density of states is calculated within the first order of the perturbation theory and the effects of the short-range disorder are explained and discussed. We demonstrate that the magnetic field values corresponding to the characteristic narrowing of the density of states width are given by the zeros of the subsequent Laguerre polynomials. The observed increase of the density of states at the edges are interpreted as van Hove singularities. The broadening effects are shown to modify and smear out the observed effects with increasing temperature above 2 K. The plasmon dispersion relation is discussed in terms of the random phase approximation. Small changes in plasmon dispersion relation related to the periodic modulation were predicted.

(15p.)
134. Ahmad R., Gethin D.T., Lewis R.W., Postek E., Design sensitivity of a sequentially coupled problem: casting, ACME 2004, 12th Association of Computational Mechanics in Engineering Annnual Conference, 2004-04-05/04-06, Cardiff (GB), pp.1-4, 2004

Streszczenie:
The presented paper deals with the design sensitivity of a sequentially coupled thermo-mechanical problem. The key finding is to provide a tool for optimisation software (analytical design sensitivity gradients) for a sequentially coupled thermal-mechanical problem.

Słowa kluczowe:
casting process, thermomechanics, parameter sensitivity analysis

135. Postek E.W., Lewis R.W., Gethin D.T., Ransing R.S., Finite element model of mould filling during squeeze forming processes, ACME 2004, 12th Association of Computational Mechanics in Engineering Annnual Conference, 2004-04-05/04-06, Cardiff (GB), pp.1-4, 2004

Streszczenie:
During mould filling due to decreasing of liquidus temperature takes place solidification pocess. The paper deals mostly with a presentation of an application of a microstructural solidification model. The Navier Stokes equation describing the flow problem is solved using Taylor Galerkin method.

Słowa kluczowe:
mould filling, microstructural solidification, thermomechanics

136. Dong L.L., Lewis R.W., Gethin D.T., Postek E.W., Simulation of deformation of ductile pharmaceutical particles with finite element method, ACME 2004, 12th Association of Computational Mechanics in Engineering Annnual Conference, 2004-04-05/04-06, Cardiff (GB), pp.1-5, 2004

Streszczenie:
In order to guarantee the strength and thus the quality of the tablets produced during the tabletting process, it is essential to understand the deforming characteristics of excipient binders. The present numerical work is motivated to provide an insight into the mechanical behaviour of the particle deformation of the excipient binder. In the present study pregelatinised starch is selected, which is known to behave in a ductile manner during compaction. An elasto-viscoplastic material model has been selected in the present study to simulate the deformation behaviour of the pregelatinised starch. Elasto-viscoplastic model 1S chosen because all the plastic deformation exhibits rate-dependency to some extent, and it is a well-developed model for simulating non-linear deformation which has been studied for four decades (Perzyna (1966), Zabaras and Arif (l992)).

Słowa kluczowe:
discrete element method, finite element method, viscoplasticity, adaptive meshing

Kategoria A Plus

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