Publikacje odnotowane przez trzy miesiące

1.Kowalczyk-Gajewska K., Maździarz M., Atomistic and mean-field estimates of effective stiffness tensor of nanocrystalline copper, International Journal of Engineering Science, ISSN: 0020-7225, DOI: 10.1016/j.ijengsci.2018.04.004, Vol.129, pp.47-62, 2018
Kowalczyk-Gajewska K., Maździarz M., Atomistic and mean-field estimates of effective stiffness tensor of nanocrystalline copper, International Journal of Engineering Science, ISSN: 0020-7225, DOI: 10.1016/j.ijengsci.2018.04.004, Vol.129, pp.47-62, 2018

Abstract:
The full elasticity tensor for nano-crystalline copper is derived in molecular simulations by performing numerical tests for a set of generated samples of the polycrystalline material. The results are analysed with respect to the anisotropy degree of the overall stiffness tensor resulting from the limited number of grain orientations and their spatial distribution. The dependence of the overall bulk and shear moduli of an isotropized polycrystal on the average grain diameter is analysed. It is found that while the shear modulus decreases with grain size, the bulk modulus shows negligible dependence on the grain diameter and is close to the bulk modulus of a single crystal. A closed-form mean-field model of effective elastic properties for a bulk nano-grained polycrystal with cubic grains, i.e. made of a material with cubic symmetry, is formulated. In the model all parameters are based on the data for a single crystal and on the averaged grain size without any need for additional fitting. It is shown that the proposed model provides predictions of satisfactory qualitative and quantitative agreement with atomistic simulations.

Keywords:
Molecular statics, Elasticity, Polycrystal, Effective medium, Nano-crystalline copper

(40p.)
2.Zawidzki M., Szklarski J., Effective Multi-objective Discrete Optimization of Truss-Z Layouts Using a GPU, APPLIED SOFT COMPUTING, ISSN: 1568-4946, DOI: 10.1016/j.asoc.2018.05.042, pp.1-22, 2018
Zawidzki M., Szklarski J., Effective Multi-objective Discrete Optimization of Truss-Z Layouts Using a GPU, APPLIED SOFT COMPUTING, ISSN: 1568-4946, DOI: 10.1016/j.asoc.2018.05.042, pp.1-22, 2018

Abstract:
Truss-Z (TZ) is an Extremely Modular System for creating skeletal free-form ramps and ramp networks. The TZ structures are comprised of four variations of two types of basic unit subjected to rotation. The two types of units are: R and L being a mirror reflection of each other. This paper presents a novel method based on image processing, evolutionary algorithm and intensive parallelization of multi-objective optimization of TZ layouts.

The algorithm returns a sequence of modules. The result guarantees a TZ connection between two given points (regions) and minimizes the fitness function representing certain costs associated with setting up the TZ structure.

The fitness function depends on the cost of TZ structure as well as the variety of costs related to the environment where the it is to be placed. E.g.: the earthworks, vegetation removal, obstacles avoidance, etc. There are no restrictions on the fitness function definition. It can depend on any variable which can be represented by a two-dimensional map of any property of the environment.

The formulation of the presented method is suited for application of well-established image processing methods which efficiently evaluate candidate solutions on a GPU. As a result, the employed genetic algorithm efficiently probes the search space. The practical applicability of this approach is demonstrated with three case-studies:

1) simultaneous paving of a path with congruent units in a hilly environment with trees & bushes and finding the best location for a pier over an existing river;

2) constructing of a TZ connector spanning over a mountain valley with lakes (where supports can not be placed);

3) retrofitting of an existing railway station with a large wheelchair TZ ramp of over 10 m elevation while preserving trees and minimizing the earthworks.

Keywords:
Truss-Z, Extremely Modular System, Retrofitting, accessibility, multi-objective, discrete, combinatorial, optimization, genetic algorithm, parallel computing, GPU, GPGPU

(40p.)
3.Suchorzewski J., Korol E., Tejchman J., Mróz Z., Experimental study of shear strength and failure mechanisms in RC beams scaled along height or length, ENGINEERING STRUCTURES, ISSN: 0141-0296, DOI: 10.1016/j.engstruct.2017.12.003, Vol.157, pp.203-223, 2018
Suchorzewski J., Korol E., Tejchman J., Mróz Z., Experimental study of shear strength and failure mechanisms in RC beams scaled along height or length, ENGINEERING STRUCTURES, ISSN: 0141-0296, DOI: 10.1016/j.engstruct.2017.12.003, Vol.157, pp.203-223, 2018

Abstract:
The paper presents results of laboratory experiments carried out on longitudinally reinforced concrete beams subjected to four-point bending. Beams of separately varying height and length were analyzed to investigate the size effect on nominal strength and post-critical brittleness. Beams were scaled in the height direction in the first test series and in the length direction in the second series. Due to lack of geometrical similarity, different failure mechanisms were exhibited. Load-deflection diagrams and crack paths were registered during experiments. The digital image correlation technique was applied to visualize strain localization on the concrete surface. The crack opening and crack slip displacements were also measured. The beam response was characterized by two non-dimensional parameters ηa = a/D and ηb = b/D defined as the ratios of shear and bending spans to the beam depth D assumed as the size parameter and the reinforcement position parameter ηc = c′/D. Two major failure mechanisms were observed: flexural failure in the central beam zone combined with plastic yielding of the reinforcement and the diagonal shear crack failure in external shear zones. Two distinct modes of shear failure can be specified depending on the dominance of crack opening or crack closure contact zones. Two different effective stresses associated with failure mechanisms were defined to specify the beam strength’s dependence on ηa, ηb, ηc and D. Some analytical formulae specifying the critical shear stress dependence on ηa, ηc and strengths ratio of reinforcement and concrete were presented at the end of paper and compared with experimental data.

Keywords:
Concrete beams, Longitudinal reinforcement, Four-point bending, Failure modes, Height or length variation, Size effect

(35p.)
4.Pieczyska E.A., Maj M., Golasiński K., Staszczak M., Furuta T., Kuramoto S., Thermomechanical Studies of Yielding and Strain Localization Phenomena of Gum Metal under Tension, Materials, ISSN: 1996-1944, DOI: 10.3390/ma11040567, Vol.11, No.567, pp.1-13, 2018
Pieczyska E.A., Maj M., Golasiński K., Staszczak M., Furuta T., Kuramoto S., Thermomechanical Studies of Yielding and Strain Localization Phenomena of Gum Metal under Tension, Materials, ISSN: 1996-1944, DOI: 10.3390/ma11040567, Vol.11, No.567, pp.1-13, 2018

Abstract:
This paper presents results of investigation of multifunctional -Ti alloy Gum Metal subjected to tension at various strain rates. Digital image correlation was used to determine strain distributions and stress-strain curves, while infrared camera allowed for us to obtain the related temperature characteristics of the specimen during deformation. The mechanical curves completed by the temperature changes were applied to analyze the subsequent stages of the alloy loading. Elastic limit, recoverable strain, and development of the strain localization were studied. It was found that the maximal drop in temperature, which corresponds to the yield limit of solid materials, was referred to a significantly lower strain value in the case of Gum Metal in contrast to its large recoverable strain. The temperature increase proves a dissipative character of the process and is related to presence of w and a” phases induced during the alloy fabrication and their exothermic phase transformations activated under loading. During plastic deformation, both the strain and temperature distributions demonstrate that strain localization for higher strain rates starts nucleating just after the yield limit leading to specimen necking and rupture. Macroscopically, it is exhibited as softening of the stress-strain curve in contrast to the strain hardening observed at lower strain rates.

Keywords:
gum metal, yield limit, thermomechanical coupling, infrared thermography, digital image correlation, strain localization

(35p.)
5.Dulnik J., Kołbuk D., Denis P., Sajkiewicz P., The effect of a solvent on cellular response to PCL/gelatin and PCL/collagen electrospun nanofibres, EUROPEAN POLYMER JOURNAL, ISSN: 0014-3057, DOI: 10.1016/j.eurpolymj.2018.05.010, Vol.104, pp.147-156, 2018
Dulnik J., Kołbuk D., Denis P., Sajkiewicz P., The effect of a solvent on cellular response to PCL/gelatin and PCL/collagen electrospun nanofibres, EUROPEAN POLYMER JOURNAL, ISSN: 0014-3057, DOI: 10.1016/j.eurpolymj.2018.05.010, Vol.104, pp.147-156, 2018

Abstract:
Bicomponent polycaprolactone/gelatin and polycaprolactone/collagen fibres were formed by electrospinning using two kinds of solvents: a representative of commonly used solvents with this polymer composition, highly toxic hexafluoroisopropanol (HFIP) and alternative, less harmful one, the mixture of acetic (AA) and formic (FA) acids. Both material types were subjected to investigations of structure and in-vitro cellular activity. Viscosity and Fourier transform infrared spectroscopy (FTIR) measurements shown that the type of solvent used influences the structure of solution and conformation of polymer molecules. In-vitro quantitative tests as well as cell culture morphology observations proved that materials electrospun with the use of ‘green’ solvents can yield similar results to those obtained by made with toxic ones. Slightly better cellular response to materials electrospun from HFIP can be explained by relatively well dispersed components within the fibre and more expanded conformation of molecules, resulting in better exposition of RGD (Arg-Gly-Asp) binding sites to cells’ integrin receptors.

Keywords:
Cellular tests, Electrospinning, Biopolymers, Viscosity, Solvents

(35p.)
6.Jeznach O., Kołbuk D., Sajkiewicz P., Injectable hydrogels and nanocomposite hydrogels for cartilage regeneration, Journal of Biomedical Materials Research Part A, ISSN: 1549-3296, DOI: 10.1002/jbm.a.36449, pp.1-51, 2018
Jeznach O., Kołbuk D., Sajkiewicz P., Injectable hydrogels and nanocomposite hydrogels for cartilage regeneration, Journal of Biomedical Materials Research Part A, ISSN: 1549-3296, DOI: 10.1002/jbm.a.36449, pp.1-51, 2018

Abstract:
Cartilage loss due to age‐related degeneration and mechanical trauma is a significant and challenging problem in the field of surgical medicine. Unfortunately, cartilage tissue can be characterized by the lack of regenerative ability. Limitations of conventional treatment strategies, such as auto‐, allo‐ and xenografts or implants stimulate an increasing interest in the tissue engineering approach to cartilage repair. This review discusses the application of polymer‐based scaffolds, with an emphasis on hydrogels in cartilage tissue engineering. We highlight injectable hydrogels with various micro‐ and nanoparticles, as they constitute a novel and attractive type of scaffolds. We discuss advantages, limitations and future perspectives of injectable nanocomposite hydrogels for cartilage tissue regeneration.

Keywords:
polymers, hydrogels, injectable hydrogels, injectable nanocomposite hydrogels, cartilage repair, cartilage tissue engineering

(35p.)
7.Postek E., Sadowski T., Distributed microcracking process of WC/Co cermet under dynamic impulse compressive loading , COMPOSITE STRUCTURES, ISSN: 0263-8223, DOI: 10.1016/j.compstruct.2018.04.014, Vol.194, pp.494-508, 2018
Postek E., Sadowski T., Distributed microcracking process of WC/Co cermet under dynamic impulse compressive loading , COMPOSITE STRUCTURES, ISSN: 0263-8223, DOI: 10.1016/j.compstruct.2018.04.014, Vol.194, pp.494-508, 2018

Abstract:
Cermet Materials (CM), for example, WC/Co, have very good mechanical, thermal and wear properties. They are used for manufacturing of cutting tools. However, their behavior under dynamic loads is still not properly understood.
Experiments, e.g. Siegl and Fischmester (1988) and Ravichandran (1994), indicate that the fracture energy of
WC/Co is expended through ductile failure of the Co: (1) close to the binder/tungsten carbide interface (Liu et al., 2017) [64] or by (2) dimple rupture across the interphase (Sigl and Exner, 1987) [22]. Stress concentrations around grain boundaries lead to initiation of microcracks which are dispersed by dynamic loading.
The main goal of the paper is to investigate the previously formulated models of the two-phase composite (Sadowski et al., 2005, 2006, 2007; Dębski and Sadowski, 2014, 2017) [47–51] in the case of dynamic compressive
pulses that are common in the case of cutting tools. We have taken into account complex spatial distribution of cermet phases, grain/binder interfaces modeled by interface elements, possibility of cracks appearance within binders using interface elements as well, and rotation of brittle grains.
The obtained results show that microcracking process and stress distributions are different for quasi-static and dynamic loadings. Early development of microcracks distribution revealed by damage parameter was observed.

Keywords:
Cermet, Dynamic compressive impulse, Interface elements, Distributed microcracking process

(35p.)
8.Vakis A.I., Yastrebov V.A., Scheibert J., Nicola L., Dini D., Minfray C., Almqvist A., Paggi M., Lee S., Limbert G., Molinari J.F., Anciaux G., Aghababaei R., Echeverri Restrepo S., Papangelo A., Cammarata A., Nicolini P., Putignano C., Carbone G., Stupkiewicz S., Lengiewicz J., Costagliola G., Bosia F., Guarino R., Pugno N.M., Müser M.H., Ciavarella M., Modeling and simulation in tribology across scales: An overview, TRIBOLOGY INTERNATIONAL, ISSN: 0301-679X, DOI: 10.1016/j.triboint.2018.02.005, Vol.125, pp.169-199, 2018
Vakis A.I., Yastrebov V.A., Scheibert J., Nicola L., Dini D., Minfray C., Almqvist A., Paggi M., Lee S., Limbert G., Molinari J.F., Anciaux G., Aghababaei R., Echeverri Restrepo S., Papangelo A., Cammarata A., Nicolini P., Putignano C., Carbone G., Stupkiewicz S., Lengiewicz J., Costagliola G., Bosia F., Guarino R., Pugno N.M., Müser M.H., Ciavarella M., Modeling and simulation in tribology across scales: An overview, TRIBOLOGY INTERNATIONAL, ISSN: 0301-679X, DOI: 10.1016/j.triboint.2018.02.005, Vol.125, pp.169-199, 2018

Abstract:
This review summarizes recent advances in the area of tribology based on the outcome of a Lorentz Center workshop surveying various physical, chemical and mechanical phenomena across scales. Among the main themes discussed were those of rough surface representations, the breakdown of continuum theories at the nano- and microscales, as well as multiscale and multiphysics aspects for analytical and computational models relevant to applications spanning a variety of sectors, from automotive to biotribology and nanotechnology. Significant effort is still required to account for complementary nonlinear effects of plasticity, adhesion, friction, wear, lubrication and surface chemistry in tribological models. For each topic, we propose some research directions.

Keywords:
Tribology, Multiscale modeling, Multiphysics modeling, Roughness, Contact, Friction, Adhesion, Wear, Lubrication, Tribochemistry

(35p.)
9.Nowicki A., Trawiński Z., Gambin B., Secomski W., Szubielski M., Parol M., Olszewski R., 20-MHZ ULTRASOUND FOR MEASUREMENTS OFFLOW-MEDIATED DILATION AND SHEAR RATE IN THE RADIALARTERY , ULTRASOUND IN MEDICINE AND BIOLOGY, ISSN: 0301-5629, DOI: 10.1016/j.ultrasmedbio.2018.02.011, Vol.44, No.6, pp.1187-1197, 2018
Nowicki A., Trawiński Z., Gambin B., Secomski W., Szubielski M., Parol M., Olszewski R., 20-MHZ ULTRASOUND FOR MEASUREMENTS OFFLOW-MEDIATED DILATION AND SHEAR RATE IN THE RADIALARTERY , ULTRASOUND IN MEDICINE AND BIOLOGY, ISSN: 0301-5629, DOI: 10.1016/j.ultrasmedbio.2018.02.011, Vol.44, No.6, pp.1187-1197, 2018

Abstract:
A high-frequency scanning system consisting of a 20-MHz linear array transducer combined with a 20-MHz pulsed Dopplerprobe was introduced to evaluate the degree of radial artery flow-mediated dilation (FMD [%]) in two groups of patients after5 min of controlled forearm ischemia followed by reactive hyperemia. In group I, comprising 27 healthy volunteers, FMD (mean ± standard deviation) was 15.26 ± 4.90% (95% confidence interval [CI]: 13.32%–17.20%); in group II, comprising 17 patients with chronic coronary artery disease, FMD was significantly less at 4.53 ± 4.11% (95% CI: 2.42%–6.64%). Specifically, the ratio FMD/SR (mean ± standard deviation),wasequalto5.36×10−4±4.64×10−4 (95%CI:3.54×10−4 to7.18×10−4)ingroupIand1.38×10−4±0.89×10−4 (95% CI: 0.70 × 10−4 to 2.06 × 10−4) in group II. Statistically significant differences between the two groups were confirmed by a Wilcoxon–Mann–Whitney test for both FMD and FMD/SR (p < 0.01). Areas under receiver operating characteristic curves for FMD and FMD/SR were greater than 0.9. The results confirm the usefulness of the proposed measurements of radial artery FMD and SR in differentiation of normal patients from those with chronic coronary artery disease. (E-mail: Ten adres pocztowy jest chroniony przed spamowaniem. Aby go zobaczyć, konieczne jest włączenie w przeglądarce obsługi JavaScript. ) © 2018 World Federation for Ultrasound in Medicine & Biology. All rights reserved.

Keywords:
Flow-mediated vasodilation,Radial artery,Shear rate,Reactive hyperemia,Endothelium,Pulsed doppler, Ultrasonography.

(35p.)
10.Jarząbek D.M., The impact of weak interfacial bonding strength on mechanical properties of metal matrix - ceramic reinforced composites, COMPOSITE STRUCTURES, ISSN: 0263-8223, DOI: 10.1016/j.compstruct.2018.06.071, Vol.201, pp.352-362, 2018
Jarząbek D.M., The impact of weak interfacial bonding strength on mechanical properties of metal matrix - ceramic reinforced composites, COMPOSITE STRUCTURES, ISSN: 0263-8223, DOI: 10.1016/j.compstruct.2018.06.071, Vol.201, pp.352-362, 2018

Abstract:
In this work the influence of weak interface between particles and matrix on mechanical properties of metal matrix – ceramic reinforced composites is studied. Firstly, the samples made of coelectrodeposited Ni-SiC composites with 10% of SiC with poor interface bonding have been prepared. Furthermore, the tensile tests of samples have been performed. The determined Young’s modulus was equal to 67 ± 8 GPa and the ultimate tensile strength to 230 ± 15 MPa. It is assumed that the very weak interface is the reason for the poor mechanical properties of the created material. In order to confirm the assumption and get the necessary parameters for the numerical model, the measurements of the normal and shear interfacial bonding strength of the interface have been performed. The measured normal interfacial bonding strength is equal to 0.1 ± 0.03 MPa and the interfacial shear strength is equal to 4.9 ± 0.2 MPa. The experimental results have been confirmed qualitatively by the computer simulations. Representative Volume Element has been created and modelled by the Finite Element Method with cohesive zone elements. The computer simulations result in the Young’s modulus values from 119 GPa up to 126 GPa.

Keywords:
Interfacial bonding strength, Metal matrix composites, Tensile strength, Silicon carbide, Electrodeposited nickel, Cohesive elements

(35p.)
11.Kubissa W., Glinicki M.A., Dąbrowski M., Permeability testing of radiation shielding concrete manufactured at industrial scale, MATERIALS AND STRUCTURES, ISSN: 1359-5997, DOI: 10.1617/s11527-018-1213-0, Vol.51, No.83, pp.1-15, 2018
Kubissa W., Glinicki M.A., Dąbrowski M., Permeability testing of radiation shielding concrete manufactured at industrial scale, MATERIALS AND STRUCTURES, ISSN: 1359-5997, DOI: 10.1617/s11527-018-1213-0, Vol.51, No.83, pp.1-15, 2018

Abstract:
The effect of the composition of industrial concrete designed for radiation shielding structures on the air permeability and the diffusion of moisture was studied. The mix design for heavyweight concrete of bulk density 3168–3317 kg/m3 was developed using barite and magnetite aggregate and cements blended with fly ash and blastfurnace slag. Structural elements, like columns of a height of 4 m and massive blocks made of mixtures with different cements were manufactured using ready mixed concrete pumped into the formwork. Core specimens were taken from the elements at different locations. The air permeability index was tested using Autoclam device. Evaluation of the quality of concrete on the basis of API results varied from “very good” to “good”. The moisture distribution inside concrete specimens was equilibrated to RH = 60 ± 5%. Observation of RH changes allowed to determine the moisture diffusion coefficient. Significant differences of the permeability and moisture diffusion coefficient depending on the location of the core specimens drilling and mix design of concrete were found. The D coefficient provided a good reflection of the different quality of heavyweight concrete in structural elements.

Keywords:
Air permeability, Autoclam, Barite, Blended cement, Cracking, Heavyweight aggregate, Magnetite, Moisture diffusion, Radiation shielding concrete, Relative humidity

(35p.)
12.Krajewski M., Brzozka K., Tokarczyk M., Kowalski G., Lewinska S., Slawska-Waniewska A., Lin W.S., Lin H.M., Impact of thermal oxidation on chemical composition and magnetic properties of iron nanoparticles, Journal of Magnetism and Magnetic Materials, ISSN: 0304-8853, DOI: 10.1016/j.jmmm.2018.03.047, Vol.458, pp.346-354, 2018
Krajewski M., Brzozka K., Tokarczyk M., Kowalski G., Lewinska S., Slawska-Waniewska A., Lin W.S., Lin H.M., Impact of thermal oxidation on chemical composition and magnetic properties of iron nanoparticles, Journal of Magnetism and Magnetic Materials, ISSN: 0304-8853, DOI: 10.1016/j.jmmm.2018.03.047, Vol.458, pp.346-354, 2018

Abstract:
The main objective of this work is to study the influence of thermal oxidation on the chemical composition and magnetic properties of iron nanoparticles which were manufactured in a simple chemical reduction of Fe3+ ions coming from iron salt with sodium borohydride. The annealing processing was performed in an argon atmosphere containing the traces of oxygen to avoid spontaneous oxidation of iron at temperatures ranging from 200 °C to 800 °C. The chemical composition and magnetic properties of as-prepared and thermally-treated nanoparticles were determined by means of X-ray diffractometry, Raman spectroscopy, Mössbauer spectroscopy and vibrating sample magnetometry. Due to the magnetic interactions, the investigated iron nanoparticles tended to create the dense aggregates which were difficult to split even at low temperatures. This caused that there was no empty space between them, which led to their partial sintering at elevated temperatures. These features hindered their precise morphological observations using the electron microscopy techniques. The obtained results show that the annealing process up to 800 °C resulted in a progressive change in the chemical composition of as-prepared iron nanoparticles which was associated with their oxidation. As a consequence, their magnetic properties also depended on the annealing temperature. For instance, considering the values of saturation magnetization, its highest value was recorded for the as-prepared nanoparticles at 1 T and it equals 149 emu/g, while the saturation point for nanoparticles treated at 600 °C and higher temperatures was not reached even at the magnetic field of about 5 T. Moreover, a significant enhancement of coercivity was observed for the iron nanoparticles annealed over 600 °C.

Keywords:
Chemical composition, Chemical reduction, Iron nanoparticle, Magnetic properties, Oxidation

(30p.)
13.Balevičius R., Mróz Z., Modeling of combined slip and finite sliding at spherical grain contacts, GRANULAR MATTER, ISSN: 1434-5021, DOI: 10.1007/s10035-017-0778-6, Vol.10, pp.1-27, 2018
Balevičius R., Mróz Z., Modeling of combined slip and finite sliding at spherical grain contacts, GRANULAR MATTER, ISSN: 1434-5021, DOI: 10.1007/s10035-017-0778-6, Vol.10, pp.1-27, 2018

Abstract:
The present paper is aimed at developing the analytical description of the interaction of two contacting spheres for several classes of slip and sliding trajectories, typical in the experimental testing. The analysis accounts for memory effects in the slip regime and configurational effects in the sliding regime, expressed in terms of an active loading surface and memory surfaces within the space of contact forces. Analytical relations for contact response are derived for linear and piecewise-linear motion trajectories of the sphere. The problem of multiple contact interaction of the sphere moving over the regularly packed granular bed is also considered analytically. It is demonstrated that the dual contact activation-separation processes occur within the combined slip–sliding modes, essentially affecting the distribution of contact tractions. The results obtained are relevant for the class of contact problems requiring analysis of interaction of slip and sliding displacements, in particular in testing grain contact interaction aimed at specification of elastic, frictional and wear parameters.

Keywords:
Sphere–sphere contact, Memory rules, Slip and sliding, Displacement and force control, Monotonic and reciprocal sliding, Friction, Granular bed

(30p.)
14.Skłodowska K., Dębski P.R., Michalski J.A., Korczyk P.M., Dolata M., Zając M., Jakiela S., Simultaneous Measurement of Viscosity and Optical Density of Bacterial Growth and Death in a Microdroplet, Micromachines, ISSN: 2072-666X, DOI: 10.3390/mi9050251, Vol.9, No.5, pp.1-13, 2018
Skłodowska K., Dębski P.R., Michalski J.A., Korczyk P.M., Dolata M., Zając M., Jakiela S., Simultaneous Measurement of Viscosity and Optical Density of Bacterial Growth and Death in a Microdroplet, Micromachines, ISSN: 2072-666X, DOI: 10.3390/mi9050251, Vol.9, No.5, pp.1-13, 2018

Abstract:
Herein, we describe a novel method for the assessment of droplet viscosity moving inside microfluidic channels. The method allows for the monitoring of the rate of the continuous growth of bacterial culture. It is based on the analysis of the hydrodynamic resistance of a droplet that is present in a microfluidic channel, which affects its motion. As a result, we were able to observe and quantify the change in the viscosity of the dispersed phase that is caused by the increasing population of interacting bacteria inside a size-limited system. The technique allows for finding the correlation between the viscosity of the medium with a bacterial culture and its optical density. These features, together with the high precision of the measurement, make our viscometer a promising tool for various experiments in the field of analytical chemistry and microbiology, where the rigorous control of the conditions of the reaction and the monitoring of the size of bacterial culture are vital.

Keywords:
droplet microfluidics, cell growth, viscosity, rheology, Escherichia coli

(30p.)
15.Zawidzki M., Jankowski Ł., Optimization of modular Truss-Z by minimum-mass design under equivalent stress constraint, SMART STRUCTURES AND SYSTEMS, ISSN: 1738-1584, DOI: 10.12989/sss.2018.21.6.715, Vol.21, No.6, pp.715-725, 2018
Zawidzki M., Jankowski Ł., Optimization of modular Truss-Z by minimum-mass design under equivalent stress constraint, SMART STRUCTURES AND SYSTEMS, ISSN: 1738-1584, DOI: 10.12989/sss.2018.21.6.715, Vol.21, No.6, pp.715-725, 2018

Abstract:
Truss-Z (TZ) is an Extremely Modular System (EMS). Such systems allow for creation of structurally sound free-form structures, are comprised of as few types of modules as possible, and are not constrained by a regular tessellation of space. Their objective is to create spatial structures in given environments connecting given terminals without self-intersections and obstacle-intersections. TZ is a skeletal modular system for creating free-form pedestrian ramps and ramp networks. The previous research on TZ focused on global discrete geometric optimization of the spatial configuration of modules. This paper reports on the first attempts at structural optimization of the module for a single-branch TZ. The internal topology and the sizing of module beams are subject to optimization. An important challenge is that the module is to be universal: it must be designed for the worst case scenario, as defined by the module position within a TZ branch and the geometric configuration of the branch itself. There are four variations of each module, and the number of unique TZ configurations grows exponentially with the branch length. The aim is to obtain minimum-mass modules with the von Mises equivalent stress constrained under certain design load. The resulting modules are further evaluated also in terms of the typical structural criterion of compliance.

Keywords:
Extremely Modular System, Truss-Z, structural optimization, modular structures, minimum mass design, frame structures

(30p.)
16.Sławianowski J.J., Kovalchuk V., Gołubowska B., Martens A., Rożko E.E., Space‐time as a structured relativistic continuum, MATHEMATICAL METHODS IN THE APPLIED SCIENCES, ISSN: 0170-4214, DOI: 10.1002/mma.5087, pp.1-19, 2018
Sławianowski J.J., Kovalchuk V., Gołubowska B., Martens A., Rożko E.E., Space‐time as a structured relativistic continuum, MATHEMATICAL METHODS IN THE APPLIED SCIENCES, ISSN: 0170-4214, DOI: 10.1002/mma.5087, pp.1-19, 2018

Abstract:
There are various models of gravitation: the metrical Hilbert‐Einstein theory, a wide class of intrinsically Lorentz‐invariant tetrad theories (generally covariant in the space‐time sense), and many gauge models based on various internal symmetry groups (Lorentz, Poincare, GL(n,R), SU(2,2), GL(4,C), etc). The gauge models are usually preferred but nevertheless it is an interesting idea to develop the class of GL(4,R)‐invariant (or rather GL(n,R)‐invariant) tetrad (n‐leg) generally covariant models. This is done below and motivated by our idea of bringing back to life the Thales of Miletus concept of affine symmetry. Formally, the obtained scheme is a generally covariant tetrad (n‐leg) model, but it turns out that generally covariant and intrinsically affinely invariant models must have a kind of nonaccidental Born‐Infeld‐like structure. Let us also mention that they, being based on tetrads (n‐legs), have many features common with continuous defect theories. It is interesting that they possess some group‐theoretical solutions and more general spherically symmetric solutions, discussion of which is the main new result presented in this paper, including the applications of the 't Hooft‐Polyakov monopoles in the generally covariant theories, which enables us to find some rigorous solutions of our strongly nonlinear equations. It is also interesting that within such a framework, the normal‐hyperbolic signature of the space‐time metric is not introduced by hand but appears as a kind of solution, rather integration constants, of differential equations. Let us mention that our Born‐Infeld scheme is more general than alternative tetrad models. It may be also used within more general schemes, including also the gauge ones.

Keywords:
micromorphic medium, modified gravity, relativistic continuum, spherically symmetric solutions, theory of fundamental interactions.

(25p.)
17.Jóźwik I., Strojny-Nędza A., Chmielewski M., Pietrzak K., Kurpaska Ł., Nosewicz S., High resolution SEM characterization of nano-precipitates in ODS steels, MICROSCOPY RESEARCH AND TECHNIQUE, ISSN: 1059-910X, DOI: 10.1002/jemt.23004, Vol.81, No.5, pp.502-508, 2018
Jóźwik I., Strojny-Nędza A., Chmielewski M., Pietrzak K., Kurpaska Ł., Nosewicz S., High resolution SEM characterization of nano-precipitates in ODS steels, MICROSCOPY RESEARCH AND TECHNIQUE, ISSN: 1059-910X, DOI: 10.1002/jemt.23004, Vol.81, No.5, pp.502-508, 2018

Abstract:
The performance of the present-day scanning electron microscopy (SEM) extends far beyond delivering electronic images of the surface topography. Oxide dispersion strengthened (ODS) steel is on of the most promising materials for the future nuclear fusion reactor because of its good radiation resistance, and higher operation temperature up to 750°C. The microstructure of ODS should not exceed tens of nm, therefore there is a strong need in a fast and reliable technique for their characterization. In this work, the results of low-kV SEM characterization of nanoprecipitates formed in the ODS matrix are presented. Application of highly sensitive photo-diode BSE detector in SEM imaging allowed for the registration of single nm-sized precipitates in the vicinity of the ODS alloys. The composition of the precipitates has been confirmed by TEM-EDS.

Keywords:
ODS steels, scanning electron microscopy, spark plasma sintering

(20p.)
18.Zaremba D., Błoński S., Jachimek M., Marijnissen M.J., Jakieła S., Korczyk P.M., Investigations of modular microfluidic geometries for passive manipulations on droplets, BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, DOI: 10.24425/119068, Vol.66, No.2, pp.139-149, 2018
Zaremba D., Błoński S., Jachimek M., Marijnissen M.J., Jakieła S., Korczyk P.M., Investigations of modular microfluidic geometries for passive manipulations on droplets, BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, DOI: 10.24425/119068, Vol.66, No.2, pp.139-149, 2018

Abstract:
Multiple pipetting is a standard laboratory procedure resulting in the compartmentalisation of a liquid sample. Microfluidics offers techniques which can replace this process by the use of tiny droplets. Passive manipulation on droplets is an interesting and promising approach for the design of microfluidic devices which on one hand are easy-to-use and on the other, execute complex laboratory procedures. We present a comprehensive study of the geometry of microfluidic components which encode different operations on droplets into the structure of the device. The understanding of hydrodynamic interactions between the continuous flow and a droplet travelling through confined space of nontrivial microfluidic geometries is crucial for a rational and efficient design of new generation of modular microfluidic processors with embedded instructions.

Keywords:
microfluidics, two-phase flows, droplets

(20p.)
19.Urbanek O., Kołbuk D., Wróbel M., Articular cartilage: New directions and barriers of scaffolds development– review, International Journal of Polymeric Materials and Polymeric Biomaterials, ISSN: 0091-4037, DOI: 10.1080/00914037.2018.1452224, pp.1-16, 2018
Urbanek O., Kołbuk D., Wróbel M., Articular cartilage: New directions and barriers of scaffolds development– review, International Journal of Polymeric Materials and Polymeric Biomaterials, ISSN: 0091-4037, DOI: 10.1080/00914037.2018.1452224, pp.1-16, 2018

Abstract:
Despite progress which has been made in recent years in the field of cell-based therapies or cell scaffolds for cartilage regeneration, a lot of work still needs to be done. Scaffolds remain a great base for tissue regeneration. However, proper implantation procedures or post-treatment still await development.

In this review we summarize paths of cartilage treatment, especially focusing on cell scaffold design and manufacture. As well as the advantages and disadvantages of available or investigated methods and materials, especially focusing on cartilage scaffold design. We show the most promising directions and barriers in the creation of healthy tissue.

Keywords:
Cartilage regeneration, medical devices, scaffold development, tissue engineering

(20p.)
20.Kruk A., Gadomska-Gajadhur A., Dulnik J., Rykaczewska I., Ruśkowski P., Sebai A., Synoradzki L., Ocena właściwości użytkowych rusztowań komórkowych o strukturze gąbczastej oraz wzrostu na nich fibroblastów, POLIMERY, ISSN: 0032-2725, DOI: 10.14314/polimery.2018.4.3, Vol.63, No.4, pp.18-22, 2018
Kruk A., Gadomska-Gajadhur A., Dulnik J., Rykaczewska I., Ruśkowski P., Sebai A., Synoradzki L., Ocena właściwości użytkowych rusztowań komórkowych o strukturze gąbczastej oraz wzrostu na nich fibroblastów, POLIMERY, ISSN: 0032-2725, DOI: 10.14314/polimery.2018.4.3, Vol.63, No.4, pp.18-22, 2018

Abstract:
Zbadano wpływ dodatku ciekłych prekursorów porów na morfologię, porowatość i właściwości mechaniczne polilaktydowych rusztowań komórkowych. Rusztowania otrzymano metodą mokrej inwersji faz w wariancie freeze extraction. Oceniono cytotoksyczność wybranych rusztowań w stosunku do fibroblastów mysich oraz ich przydatność do hodowli komórkowych. Wykazano, że dodatek prekursora porów dopolilaktydu korzystnie zmienia morfologię wytworzonych rusztowań, jednocześnie pogarszając ich wytrzymałość mechaniczną. Stwierdzono, że polilaktydowe rusztowania komórkowe z powodzeniem mogą być wykorzystywane do hodowli komórkowych.

Keywords:
usztowania komórkowe, polilaktyd, hodowle komórkowe, fibroblasty

(15p.)
21.Błachowski B., Pnevmatikos N., Neural network based vibration control of seismically excited civil structures, Periodica Polytechnica Civil Engineering, ISSN: 0553-6626, DOI: 10.3311/PPci.11601, Vol.62, No.3, pp.620-628, 2018
Błachowski B., Pnevmatikos N., Neural network based vibration control of seismically excited civil structures, Periodica Polytechnica Civil Engineering, ISSN: 0553-6626, DOI: 10.3311/PPci.11601, Vol.62, No.3, pp.620-628, 2018

Abstract:
This study proposes a neural network based vibration control system designed to attenuate structural vibrations induced by an earthquake. Classical feedback control algorithms are susceptible to parameter changes. For structures with uncertain parameters they can even cause instability problems. The proposed neural network based control system can identify the structural properties of the system and avoids the above mentioned problems. In the present study it is assumed that a full state of the structure is known, which means the at each floor horizontal displacements and rotations about the vertical axis are measured. Additionally, it is assumed the acceleration signal coming from the earthquake is also available. The proposed neural control strategy is compared with the classical linear quadratic regulator (LQR) not only in terms of displacement responses, but also required control forces. Moreover, the influence of different weighting matrices on performance of the proposed control strategy has been presented.
The effectiveness of the neuro-controller has been demonstrated on two numerical examples: a simple single degree of freedom (DOF) structure and a multi-DOF structure representing a twelve story building. Both structures under consideration have been excited with El Centro acceleration signal. The results of numerical simulations on the SDOF system indicate that using neuro-controller it would be possible to obtain smaller amplitudes as compared with the LQ regulator, but it would require higher control effort.

Keywords:
vibration control, artificial neural networks, seismic excitation

(15p.)
22.Matsui R., Takeda K., Tobushi H., Pieczyska E.A., MECHANICAL PROPERTIES AND ADVANCED SUBJECTS IN SHAPE MEMORY ALLOYS AND POLYMERS, JOURNAL OF THEORETICAL AND APPLIED MECHANICS, ISSN: 1429-2955, DOI: 10.15632/jtam-pl.56.2.447, Vol.56, No.2, pp.447-456, 2018
Matsui R., Takeda K., Tobushi H., Pieczyska E.A., MECHANICAL PROPERTIES AND ADVANCED SUBJECTS IN SHAPE MEMORY ALLOYS AND POLYMERS, JOURNAL OF THEORETICAL AND APPLIED MECHANICS, ISSN: 1429-2955, DOI: 10.15632/jtam-pl.56.2.447, Vol.56, No.2, pp.447-456, 2018

Abstract:
Advanced subjects in mechanical properties of shape memory alloys and polymers are discussed. In the subloop loading under a stress-controlled condition of the shape memory alloy, the transformation-induced stress relaxation appears due to variation in temperature. The enhancement of corrosion and corrosion fatigue life of the shape memory alloy is discussed. The development of a functionally-graded shape memory alloy and polymer is expected to obtain better performance. Three-way motion appears in the shape memory composite with the shape memory alloy and polymer.

Keywords:
shape memory alloy, shape memory polymer, functionally-graded shape memory material, shape memory composite

(15p.)
23.Meissner M., A Novel Method for Determining Optimum Dimension Ratios for Small Rectangular Rooms, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, DOI: 10.24425/122369, Vol.43, No.2, pp.217-225, 2018
Meissner M., A Novel Method for Determining Optimum Dimension Ratios for Small Rectangular Rooms, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, DOI: 10.24425/122369, Vol.43, No.2, pp.217-225, 2018

Abstract:
A new method for determining optimum dimension ratios for small rectangular rooms has been presented. In a theoretical model, an exact description of the room impulse response was used. Based on the impulse response, a frequency response of a room was calculated to find changes in the sound pressure level over the frequency range 20-200 Hz. These changes depend on the source and receiver positions, thus, a new metric equivalent to an average frequency response was introduced to quantify the overall sound pressure variation within the room for a selected source position. A numerical procedure was employed to seek a minimum value of the deviation of the sound pressure level response from a smooth fitted response determined by the quadratic polynomial regression. The most smooth frequency responses were obtained when the source was located at one of the eight corners of a room. Thus, to find the best possible dimension ratios, in the numerical procedure the optimal source position was assumed. Calculation results have shown that optimum dimension ratios depend on the room volume and the sound damping inside a room, and for small and medium volumes these ratios are roughly 1:1.48:2.12, 1:1.4:1.89 and 1:1.2:1.45. When the room volume was suitably large, the ratio 1:1.2:1.44 was found to be the best one.

Keywords:
room acoustics, small rooms, optimum dimension ratios, room impulse response, frequency room response

(15p.)
24.Żurek Z.H., Dobmann G., Rockstroh B., Kukla D., Diagnostyka stanu technicznego i badania nieniszczące dla energetyki, NAPĘDY I STEROWANIE, ISSN: 1507-7764, Vol.5, pp.94-100, 2018
Żurek Z.H., Dobmann G., Rockstroh B., Kukla D., Diagnostyka stanu technicznego i badania nieniszczące dla energetyki, NAPĘDY I STEROWANIE, ISSN: 1507-7764, Vol.5, pp.94-100, 2018

Abstract:
Stal martenzytyczna P91 należy do grupy stali stosowanych w energetyce. Komponenty maszyn i wyposażenie wykorzystujące stale z tej grupy (K18 - P 265 i 13 HMF) są użytkowane w eksploatacji przy podwyższonych temperaturach. Stale te są narażone na obciążenia zmęczeniowe cieplne, przyspieszoną korozję, pełzanie dynamiczne i relaksację powodowane procesami zmęczeniowymi. Trudne warunki eksploatacji (temperatura, ciśnienie) wywierają różny wpływ na proces zmian ich parametrów fizycznych. W przypadku większości stali stosowanych w energetyce magneto-indukcyjny pomiar właściwości fizycznych jest dogodną techniką badania próbek, a nawet przy ciągłym diagnozowaniu wycinka instalacji (SHM). Artykuł prezentuje wyniki badań przeprowadzonych dla próbek stalowych P91, P265 i 13 HMF oraz proponuje niskokosztowe rozwiązanie badań nieniszczących (NDT) i monitoringu eksploatacyjnego.

Keywords:
SHM monitoring strukturalny, NDT badania nieniszczące

(5p.)
25.Dulnik J., Sajkiewicz P., Crosslinking of bicomponent nanofibres from alternative solvent system, Electrospin2018, Electrospin2018 International Conference, 2018-01-16/01-18, Stellenbosch (ZA), pp.71, 2018
26.Urbanek O., Sajkiewicz P., Pierini F., Cell response on fibres surface properties induced by process parameters and post-treatment of electrospun nonwovens, Electrospin2018, Electrospin2018 International Conference, 2018-01-16/01-18, Stellenbosch (ZA), pp.62-63, 2018
27.Sajkiewicz P., Dulnik J., Kołbuk-Konieczny D., Denis P., Structure dependent cell activity on pcl/gelatin and pcl/collagen nanofibers electrospun from various solvents, Electrospin2018, Electrospin2018 International Conference, 2018-01-16/01-18, Stellenbosch (ZA), pp.45-46, 2018
28.Pierini F., Lanzi M., Nakielski P., Pawłowska S., Urbanek O., Kowalewski T.A., Electrospinning of polythiophene with pendant fullerene nanofibers for single-material organic solar cells, Electrospin2018, Electrospin2018 International Conference, 2018-01-16/01-18, Stellenbosch (ZA), pp.19-20, 2018
29.Pawłowska S., Nakielski P., Pierini F., Electrospun polyacrylamide hydrogel nanofibers: from nanocarriers to stimuli responsive nanomaterials, Electrospin2018, Electrospin2018 International Conference, 2018-01-16/01-18, Stellenbosch (ZA), pp.39, 2018
30.Wcisło B., Pamin J., Kowalczyk-Gajewska K., Menzel A., Numerical analysis of ellipticity condition for large strain plasticity, AIP Conference Proceedings, ISSN: 0094-243X, DOI: 10.1063/1.5019150, Vol.1922, No.1, pp.140008-1-140008-8, 2018
Wcisło B., Pamin J., Kowalczyk-Gajewska K., Menzel A., Numerical analysis of ellipticity condition for large strain plasticity, AIP Conference Proceedings, ISSN: 0094-243X, DOI: 10.1063/1.5019150, Vol.1922, No.1, pp.140008-1-140008-8, 2018

Abstract:
This paper deals with the numerical investigation of ellipticity of the boundary value problem for isothermal finite strain elasto-plasticity. Ellipticity can be lost when softening occurs. A discontinuity surface then appears in the considered material body and this is associated with the ill-posedness of the boundary value problem. In the paper the condition for ellipticity loss is derived using the deformation gradient and the first Piola-Kirchhoff stress tensor. Next, the obtained condition is implemented and numerically tested within symbolic-numerical tools AceGen and AceFEM using the benchmark of an elongated rectangular plate with imperfection in plane stress and plane strain conditions.

31.Ashraf W., Glinicki M.A., Olek J., Probablistic approach for selection of composition of freeze–thaw-resistant ordinary portland cement concrete, TRB 97th Annual Meeting, 2018-01-07/01-11, Washington, D.C. (US), No.18-00237, pp.1-24, 2018
Ashraf W., Glinicki M.A., Olek J., Probablistic approach for selection of composition of freeze–thaw-resistant ordinary portland cement concrete, TRB 97th Annual Meeting, 2018-01-07/01-11, Washington, D.C. (US), No.18-00237, pp.1-24, 2018

Abstract:
This paper features the development of a probabilistic model linking freeze-thaw (F-T) performance of concrete mixtures to their composition. As part of the process of model development, a sensitivity analysis was performed on several concrete mixture parameters to identify these factors that have strong correlations with the F-T resistance of concrete. This sensitivity analysis was performed on 128 sets of experimental F-T test results collected from the literature. The F-T performance level was defined as a discrete measure of the frost resistance of concrete. Finally, a new model to predict the F-T damage of concrete incorporating the variability of the concrete mix parameters (as selected from sensitivity analysis) was developed. This model was developed using only these data sets which contained the results of the relative dynamic modulus of elasticity (RDME) testing performed according to the ASTM C 666 (AASHTO T 161) specifications. Furthermore, only mixtures containing ordinary portland cement (OPC) as a sole type of the binder (i.e., mixtures that did not contain any supplementary cementitious materials) were considered. Additional experimental test results were utilized to validate the model. The reliability of the model was further demonstrated using several examples 1 of concrete mixtures of various compositions. Furthermore, the effects of the number of F-T cycles, air content, paste content, and w/c ratio on the F-T performance of the concrete mixes were demonstrated using the developed model. Accordingly, this model provides the opportunity to optimize the concrete mix proportion for the required performance level of concrete under F-T exposure condition.

Keywords:
Freeze-thaw, durability, concrete, pavement, sensitivity analysis, probabilistic design

32.Postek E., Sadowski T., Impact modelling of cerment composite, The 7th International Conference on Advanced Materials and Structures, 2018-03-28/03-31, Timisoara (RO), pp.111, 2018
33.Postek E., Generation of a tumor model, Supercomputing Frontiers Europe wraz z XX Sesją Sprawozdawczą Użytkowników KDM, 2018-03-12/03-16, ICM UW, Warszawa (PL), pp.1-1, 2018
Postek E., Generation of a tumor model, Supercomputing Frontiers Europe wraz z XX Sesją Sprawozdawczą Użytkowników KDM, 2018-03-12/03-16, ICM UW, Warszawa (PL), pp.1-1, 2018

Abstract:
The physical environment of living cells and tissues, and more
particularly their mechanical interaction with it, plays a crucial
regulatory role in their biological behaviour such as cell
differentiation, apoptosis, proliferation, tissue growth,
remodelling, tumor growth, etc. However, the way that
mechanical forces at the cellular level (i) influence the cell
functions and (ii) govern the behaviour of cell assemblies as well
as their development, remains unclear and hard to model.
First of all, we investigate a tissue growth model. The model is
generated with PhysiCell [1, 2].

Keywords:
computational biology, tumor growth

34.Chojnacki A., Konowrocki R., Analiza numeryczna i eksperymentalna bezpieczeństwa przed wykolejeniem pojazdu szynowego w oparciu o różne metody wyznaczania kryterium oceny, XXIII Scientific Conference Railway Vehicles 2018, 2018-05-22/05-25, Szczyrk (PL), pp.8-9, 2018
Chojnacki A., Konowrocki R., Analiza numeryczna i eksperymentalna bezpieczeństwa przed wykolejeniem pojazdu szynowego w oparciu o różne metody wyznaczania kryterium oceny, XXIII Scientific Conference Railway Vehicles 2018, 2018-05-22/05-25, Szczyrk (PL), pp.8-9, 2018

Abstract:
W artykule przedstawiono wyniki badań eksperymentalnych i numerycznych dotyczących zagadnień wykolejenia wagonu towarowego. Przybliżono charakteryzację stanu wiedzy dotyczącej metod oceny bezpieczeństwa pojazdów szynowych przed wykolejeniem, w celu ich porównania. W pracy przeprowadzono teoretyczne analizy porównawcze według kilku metod, które ocenią bezpieczeństwo przed wykolejeniem porównane z badaniami eksperymentalnymi. Na potrzeby analiz teoretycznych powstał numeryczny model układu pojazd szynowy-tor. Model ten uwzględniał parametry dynamiczne elementów zastosowanych w rzeczywistym pojeździe. Wyniki analizy teoretycznej poparto badaniami eksperymentalnymi przeprowadzonymi na rzeczywistym obiekcie (wagon towarowy - tor testowy). Uzyskane wyniki pozwoliły określić stan zagrożenia bezpieczeństwa ruchu wagonu towarowego przy różnych kryteriach oceny oraz je porównać.

Keywords:
współczynnik wykolejenia, dynamiki pojazdów szynowych, bezpieczeństwo, badania eksperymentalne

35.Zbieć A., Konowrocki R., Wpływ prac konserwacyjnych na zużycie kół zestawów kołowych wagonów towarowych , XXIII Scientific Conference Railway Vehicles 2018, 2018-05-22/05-25, Szczyrk (PL), pp.12-13, 2018
Zbieć A., Konowrocki R., Wpływ prac konserwacyjnych na zużycie kół zestawów kołowych wagonów towarowych , XXIII Scientific Conference Railway Vehicles 2018, 2018-05-22/05-25, Szczyrk (PL), pp.12-13, 2018

Abstract:
Artykuł dotyczy analizy nowo zdiagnozowanej przyczyny zużycia profili kół wagonu towarowego. W pracy przybliżono możliwe przyczyny nierównomiernego zużycia kół zestawów kołowych w wagonach towarowych znane z literatury, jak również podano nową hipotezę. Nowa rozpatrywana w pracy przyczyna nadmiernego zużycia kół zestawów kołowych dotyczy nieprawidłowej ich orientacji względem ramy wózka. Sytuację taką zdiagnozowano w wagonach towarowych posadowionych na wózkach z rodziny Y25, w wyniku niepoprawnego procesu naprawy ramy wózka i regeneracji maźnic. W pracy przedstawiono wyniki pomiarów przeprowadzonych na rzeczywistym wagonie towarowym oraz identyfikację zużyć i geometrii elementów pojazdu. W celu ilościowej analizy wpływu niepoprawnie zorientowanych osi zestawów kołowych na wielkość zużycia kół powstał model numeryczny, opisujący dynamikę ww. wagonu towarowego. Obliczenia numeryczne przeprowadzono przy różnych scenariuszach prędkości i geometrii toru oraz kilku wariantach zukosowania zestawów kołowych. Otrzymane z badań numerycznych wyniki wykazały istotny wpływ nierównoległości osi zestawów kołowych na nierównomierne zużycie profili kół. Zaprezentowana w pracy teza poparta wynikami badań może w znacznym stopniu wpłynąć na poprawę technologii wykonywania napraw układu biegowego oraz warunki utrzymania towarowego taboru kolejowego. Pozwoli także na redukując kosztów napraw zestawów kołowych i wydłużenie okresu ich eksploatacji.

Keywords:
zużycie kół, dynamiki pojazdów, badania numeryczne, transport towarowy

36.Bogacz R., Konowrocki R., Uszkodzenia pojazdów szynowych wywołane usterkami toru kolejowego , XXIII Scientific Conference Railway Vehicles 2018, 2018-05-22/05-25, Szczyrk (PL), pp.80-81, 2018
Bogacz R., Konowrocki R., Uszkodzenia pojazdów szynowych wywołane usterkami toru kolejowego , XXIII Scientific Conference Railway Vehicles 2018, 2018-05-22/05-25, Szczyrk (PL), pp.80-81, 2018

Abstract:
Praca zawiera omówienie wybranych zagadnień dynamicznych związanych
z kinematycznym wymuszeniem od usterek toru wpływającym na degradację elementów pojazdów szynowych oraz rozwój uszkodzeń infrastruktury. Wskazano zjawiska, które mogą być przyczyną dużych obciążeń współdziałającego ze sobą układu pojazd-tor oraz zagrożenia wypadkami spowodowanymi zmęczeniem materiału elementów takiego układu. Podano przyczyny powstawania i rozwoju pęknięć szyn i osi zestawów kołowych. Przedstawiono przykłady badań doświadczalnych wskazujących na występowanie obciążeń dynamicznych znacznie przekraczających obciążenia statyczne spowodowane oddziaływaniem pojazdu i jego układu napędowego. Omówiono i zamieszczono w pracy wyniki badań teoretycznych uzyskanych z numerycznego modelu napędu pociągu z uwzględnieniem elektromechanicznych sprzęgnięć pomiędzy silnikiem a zestawem kołowym. Model ten pozwolił na analizę niekorzystych drgań skrętnych zestawu kołowego towarzyszących podczas przejazdu przez szczeliny w pojedynczym toku szynowym toru.
Prezentowane w pracy wyniki odniesiono do badań eksperymentalnych. W pracy przedstawiono również zagadnienia dynamiczne związane z samowzbudnością wskazujące na zjawiska, które mogą być przyczyną dużych obciążeń osi zestawów kołowych, jak również toru i ich degradacji oraz uszkodzeń zmęczeniowych tych osi. Zasygnalizowane zostały prawdopodobne przyczyny powstawania wielokrotnie większych od powszechnie uznawanych obciążeń szyn kołami kolejowymi. Podano kilka przykładów eksperymentalnego zbadania dynamicznego oddziaływania zestawów kołowych z torem będącego alternatywnym podejściem do kinematycznego wyjaśniania tego zjawiska.

Keywords:
drgania skrętne, uszkodzenia pojazdu i toru, dynamiki toru, badania numeryczne

37.Konowrocki R., Dąbrowski A., Brona P., Application of longitudinal dynamics of the train in the simulator of catenary maintenance vehicles - experimental and numerical tests , XXIII Scientific Conference Railway Vehicles 2018, 2018-05-22/05-25, Szczyrk (PL), pp.19-20, 2018
Konowrocki R., Dąbrowski A., Brona P., Application of longitudinal dynamics of the train in the simulator of catenary maintenance vehicles - experimental and numerical tests , XXIII Scientific Conference Railway Vehicles 2018, 2018-05-22/05-25, Szczyrk (PL), pp.19-20, 2018

Abstract:
The paper presents results obtained from experimental and simulation tests of trains, treated as simplified one-dimensional models of railway vehicles. This approach to train dynamics enables to assess train forces and their impact on dynamic characteristics, for example related to some problems of rapid starting or emergency braking. These works were used to implement them as a solver mechanism in the simulator of catenary maintenance trains, whose features in the article are discussed. In the paper algorithm of operating vehicles by their drivers in different driving scenarios are presents. The algorithm described simulator must meet atypical requirements resulting from the specific properties of the simulated vehicles.The paper describes also the methodology of identifying driving system of modeled vehicles and the way of adaptation of parameters obtained experimentally. Then, in brief, issues related to the image animation and presentation in the simulator are discussed. Also the most important rules of operating rail vehicle simulator, selecting proper scenarios and using effective training methods are characterised. Results of operational and numerical tests presented in the paper reflect in details processes accompanying the operation of catenary maintenance trains. The experimental test methodology to the real railway vehicles to acquire some missing work parameters was allowed. Results of the presented research indicate a large convergence of theoretical results with the experiment.The obtained result allowed to validate the work of the simulator

Keywords:
training simulator, dynamics of the train, experimental test, VBS3 environmental

38.Konowrocki R., Modeling of dynamic aspects of operation railway vehicle traction drive system including the electromechanical coupling , XXIII Scientific Conference Railway Vehicles 2018, 2018-05-22/05-25, Szczyrk (PL), pp.46-47, 2018
Konowrocki R., Modeling of dynamic aspects of operation railway vehicle traction drive system including the electromechanical coupling , XXIII Scientific Conference Railway Vehicles 2018, 2018-05-22/05-25, Szczyrk (PL), pp.46-47, 2018

Abstract:
In the paper, a dynamic electromechanical interaction between the wheelset of railway vehicle and its driving electric motors is investigated. This is the high-speed train driven by the electric motors through elastic hollow shaft with linear characteristics. In particular, there is considered an influence of negative electromagnetic damping generated by the motor on a possibility of excitation of resonant torsional vibrations. Conclusions drawn from the computational results can be very useful during a design phase of these devices as well as helpful for their users during a regular maintenance.

Keywords:
electromechanical coupling, torsion oscilation, electric motor, high speed train drive

39.Konowrocki R., Groll W., Kukulski J., Walczak S., Badania doświadczalne i symulacyjne powstawania gorących obszarów w parach ciernych hamulca kolejowego pociągów dużych prędkości , XXIII Scientific Conference Railway Vehicles 2018, 2018-05-22/05-25, Szczyrk (PL), pp.20-21, 2018
Konowrocki R., Groll W., Kukulski J., Walczak S., Badania doświadczalne i symulacyjne powstawania gorących obszarów w parach ciernych hamulca kolejowego pociągów dużych prędkości , XXIII Scientific Conference Railway Vehicles 2018, 2018-05-22/05-25, Szczyrk (PL), pp.20-21, 2018

Abstract:
Pracę poświęcono eksperymentalnym i numerycznym badaniom dotyczącym występowania gorących punktów w elementach hamulców tarczowych stosowanego w pojazdach szynowych dużej prędkości. W pracy zaprezentowano wyniki eksperymentalnych badań przeprowadzone na rzeczywistym układzie hamulcowym dedykowanym do takich pojazdów. W badaniach eksperymentalnych wykorzystano technikę termografii w podczerwieni, która pozwoliła scharakteryzować omawiane zjawiska cieplne. Uzyskane wyniki badań doświadczanych potwierdzono analizami numerycznymi, przy wykorzystaniu z walidowanego modelu układu hamulcowego. Wykorzystano w tym celu metodę elementów skończonych. Otrzymane wyniki numeryczne ilustrują zjawisko powstawania gorących obszarów na powierzchni tarczy hamulcowej wywołane przez termoelastyczne zaburzenia występujące na jej powierzchni.

Keywords:
gorące obszary, badania numeryczne, badania eksperymentalne, układ hamulcowy, pociągi dużych prędkości

40.Jóźwiak-Niedźwiedzka D., Dąbrowski M., Gibas K., Antolik A., Glinicki M.A., Alkali-silica reaction and microstructure of concrete subjected to combined chemical and physical exposure conditions, MATBUD'2018, 8th Scientific-Technical Conference on Material Problems in Civil Engineering MATBUD'2018, 2018-06-25/06-27, Kraków, Politechnika Krakowska (PL), DOI: 10.1051/matecconf/201816305009, No.163, pp.05009-1-05009-10, 2018
Jóźwiak-Niedźwiedzka D., Dąbrowski M., Gibas K., Antolik A., Glinicki M.A., Alkali-silica reaction and microstructure of concrete subjected to combined chemical and physical exposure conditions, MATBUD'2018, 8th Scientific-Technical Conference on Material Problems in Civil Engineering MATBUD'2018, 2018-06-25/06-27, Kraków, Politechnika Krakowska (PL), DOI: 10.1051/matecconf/201816305009, No.163, pp.05009-1-05009-10, 2018

Abstract:
Salt solutions are used to ensure safe driving conditions during winter. NaCl deicer is the most often used brine in Polish climatic zone. The chemical effects of this type of chloride-based deicer in wetting and drying (WD) and temperature cycles on concrete need to be better understood. This research was focus to study the microstructure of air-entrained pavement concrete after combined chemical (10% of NaCl) and physical (WD and 60°C) exposure conditions. The adopted WD and temperature regime was designed to verify the hypothesis that regularly alternating wetting and drying cycles with external alkali supply from deicer salt will provoke the Alkali-Silica Reaction (ASR). The aggregates varied their origin and mineralogical composition. The microscopic examination was carried out on concrete specimens using SEM with EDX. The microscopic analysis has shown that main reason for concrete deterioration during cyclic chemical and physical exposure conditions was both physical influence - WD cycles and the chemical influence – ASR (primarily, the fine aggregate which lead to form of alkali-silica gel). The expansive gel was shown to be capable of destroying the test specimens. Also differences in mineralogical composition of coarse aggregates influenced on the concrete prism expansion due to ASR.

41.Antolik A., Glinicki M.A., Gawlicki M., Effect of boron-containing aggregates on setting and hardening of Portland cement mortars, MATBUD'2018, 8th Scientific-Technical Conference on Material Problems in Civil Engineering MATBUD'2018, 2018-06-25/06-27, Kraków, Politechnika Krakowska (PL), DOI: 10.1051/matecconf/201816304003, No.163, pp.04003-1-04003-6, 2018
Antolik A., Glinicki M.A., Gawlicki M., Effect of boron-containing aggregates on setting and hardening of Portland cement mortars, MATBUD'2018, 8th Scientific-Technical Conference on Material Problems in Civil Engineering MATBUD'2018, 2018-06-25/06-27, Kraków, Politechnika Krakowska (PL), DOI: 10.1051/matecconf/201816304003, No.163, pp.04003-1-04003-6, 2018

Abstract:
Multicomponent cement-based composites are known as versatile structural materials for enhanced radiation shielding. The use of selected elements, like boron, cadmium, or rare earth elements, provides an increased neutron shielding capacity. Because of profusion, reasonable costs and large cross-section for neutron capture, boron containing minerals are suggested as aggregates for radiation shielding concrete. Despite many advantages, boron additives may act as cement setting retarders. Uncontrolled setting and hardening is not acceptable in radiation shielding concrete technology. In this work we present results from isothermal calorimetry measurements on cement mortars with boron-containing aggregates. Four types of boron aggregates were used in the studies: colemanite, ulexite, borax and boron carbide. Based on calorimetric curves, the beginning of setting time was determined. Additionally early mortar strength was investigated and linear relationship between the heat generated in the isothermal calorimeter and the early compressive strength has been observed. The use of isothermal calorimetry allowed us to estimate the limits for the content of boron compounds to be used cement mortar.

42.Czarny P., Kwiatkowski D., Toma M., Kubiak J., Sliwinska A., Talarowska M., Szemraj J., Maes M., Galecki P., Sliwinski T., Impact of single-nucleotide polymorphisms of base excision repair genes on DNA damage and efficiency of DNA repair in recurrent depression disorder, MOLECULAR NEUROBIOLOGY, ISSN: 0893-7648, DOI: 10.1007/s12035-016-9971-6, Vol.54, No.6, pp.4150-4159, 2017
Czarny P., Kwiatkowski D., Toma M., Kubiak J., Sliwinska A., Talarowska M., Szemraj J., Maes M., Galecki P., Sliwinski T., Impact of single-nucleotide polymorphisms of base excision repair genes on DNA damage and efficiency of DNA repair in recurrent depression disorder, MOLECULAR NEUROBIOLOGY, ISSN: 0893-7648, DOI: 10.1007/s12035-016-9971-6, Vol.54, No.6, pp.4150-4159, 2017

Abstract:
Elevated level of DNA damage was observed in patients with depression. Furthermore, single nucleotide polymorphisms (SNPs) of base excision repair (BER) genes may modulate the risk of this disease. Therefore, the aim of this study was to delineate the association between DNA damage, DNA repair, the presence of polymorphic variants of BER genes, and occurrence of depression. The study was conducted on peripheral blood mononuclear cells of 43 patients diagnosed with depression and 59 controls without mental disorders. Comet assay was used to assess endogenous (oxidative) DNA damage and efficiency of DNA damage repair (DRE). TaqMan probes were employed to genotype 12 SNPs of BER genes. Endogenous DNA damage was higher in the patients than in the controls, but none of the SNPs affected its levels. DRE was significantly higher in the controls and was modulated by BER SNPs, particularly by c.977C > G-hOGG1, c.972G > C-MUTYH, c.2285T > C-PARP1, c.580C > T-XRCC1, c.1196A > G-XRCC1, c.444T > G-APEX1, c.-468T > G-APEX1, or c.*50C > T-LIG3. Our study suggests that both oxidative stress and disorders in DNA damage repair mechanisms contribute to elevated levels of DNA lesions observed in depression. Lower DRE can be partly attributed to the presence of specific SNP variants.

Keywords:
Recurrent depression disorder, DNA damage, DNA repair, Oxidative stress, Base excision repair, Single nucleotide polymorphism

(40p.)
43.Sliwinska A., Sitarek P., Toma M., Czarny P., Synowiec E., Krupa R., Wigner P., Bialek K., Kwiatkowski D., Korycinska A., Majsterek I., Szemraj J., Galecki P., Sliwinski T., Decreased expression level of BER genes in Alzheimer’s disease patients is not derivative of their DNA methylation status, PROGRESS IN NEURO-PSYCHOPHARMACOLOGY & BIOLOGICAL PSYCHIATRY, ISSN: 0278-5846, DOI: 10.1016/j.pnpbp.2017.07.010, Vol.79, pp.311-316, 2017
Sliwinska A., Sitarek P., Toma M., Czarny P., Synowiec E., Krupa R., Wigner P., Bialek K., Kwiatkowski D., Korycinska A., Majsterek I., Szemraj J., Galecki P., Sliwinski T., Decreased expression level of BER genes in Alzheimer’s disease patients is not derivative of their DNA methylation status, PROGRESS IN NEURO-PSYCHOPHARMACOLOGY & BIOLOGICAL PSYCHIATRY, ISSN: 0278-5846, DOI: 10.1016/j.pnpbp.2017.07.010, Vol.79, pp.311-316, 2017

Abstract:
Background: Neurodegeneration in Alzheimer's disease can be caused by accumulation of oxidative DNA damage resulting from altered expression of genes involved in the base excision repair system (BER). Promoter methylation can affect the profile of BER genes expression. Decreased expression of BER genes was observed in the brains of AD patients.

Aim of the study: The aim of our study was to compare the expression and methylation profiles of six genes coding for proteins involved in BER, namely: hOGG1, APE1, MUTYH, NEIL1, PARP1 and XRCC1, in the peripheral blood cells of AD patients and healthy volunteers.

Methods: The study consisted of 100 persons diagnosed with Alzheimer's disease according to DSM-IV criteria, and 110 healthy volunteers. DNA and total RNA were isolated from venous blood cells. Promoter methylation profiles were obtained by High Resolution Melting (HRM) analysis of bisulfide converted DNA samples. Real-time PCR with TaqMan probes was employed for gene expression analysis.

Results: APE1, hOGG1, MUTYH, PARP1 and NEIL1 were significantly (p < 0.001) down-regulated in the lymphocytes of AD patients, as compared to healthy volunteers. Expression of XRCC1 didn't differ significantly between both groups. We did not find any differences in the methylation pattern of any of the investigated BER genes.

Conclusions: The methylation status of promoters is not associated with downregulation of BER genes. Our results show that downregulation of BER genes detected in peripheral blood samples could reflect the changes occurring in the brain of patients with AD, and may be a useful biomarker of this disease.

Keywords:
Alzheimer's disease, DNA base excision repair genes, Gene expression, Promoter methylation

(35p.)
44.Kwiatkowski D., Czarny P., Toma M., Jurkowska N., Śliwinska A., Drzewoski J., Bachurska A., Szemraj J., Maes M., Berk M., Su K.P., Gałecki P., Śliwiński T., Associations between DNA Damage, DNA Base Excision Repair Gene Variability and Alzheimer's Disease Risk, DEMENTIA AND GERIATRIC COGNITIVE DISORDERS, ISSN: 1420-8008, DOI: 10.1159/000443953, Vol.41, No.3-4, pp.152-171, 2016
Kwiatkowski D., Czarny P., Toma M., Jurkowska N., Śliwinska A., Drzewoski J., Bachurska A., Szemraj J., Maes M., Berk M., Su K.P., Gałecki P., Śliwiński T., Associations between DNA Damage, DNA Base Excision Repair Gene Variability and Alzheimer's Disease Risk, DEMENTIA AND GERIATRIC COGNITIVE DISORDERS, ISSN: 1420-8008, DOI: 10.1159/000443953, Vol.41, No.3-4, pp.152-171, 2016

Abstract:
Background: Increased oxidative damage to DNA is one of the pathways involved in Alzheimer's disease (AD). Insufficient base excision repair (BER) is in part responsible for increased oxidative DNA damage. The aim of the present study was to assess the effect of polymorphic variants of BER-involved genes and the peripheral markers of DNA damage and repair in patients with AD. Material and Methods: Comet assays and TaqMan probes were used to assess DNA damage, BER efficiency and polymorphic variants of 12 BER genes in blood samples from 105 AD patients and 130 controls. The DNA repair efficacy (DRE) was calculated according to a specific equation. Results: The levels of endogenous and oxidative DNA damages were higher in AD patients than controls. The polymorphic variants of XRCC1 c.580C>T XRCC1 c.1196A>G and OGG1 c.977C>G are associated with increased DNA damage in AD. Conclusion: Our results show that oxidative stress and disturbances in DRE are particularly responsible for the elevated DNA lesions in AD. The results suggest that oxidative stress and disruption in DNA repair may contribute to increased DNA damage in AD patients and risk of this disease. In addition, disturbances in DRE may be associated with polymorphisms of OGG1 and XRCC1.

Keywords:
DNA damage, DNA base excision repair, Alzheimer's disease risk, Dementia, Oxidative stress

(30p.)
45.Sliwinska A., Kwiatkowski D., Czarny P., Toma M., Wigner P., Drzewoski J., Fabianowska-Majewska K., Szemraj J., Maes M., Gałecki P., Śliwiński T., The levels of 7,8-dihydrodeoxyguanosine (8-oxoG) and 8-oxoguanine DNA glycosylase 1 (OGG1) - A potential diagnostic biomarkers of Alzheimer's disease, JOURNAL OF THE NEUROLOGICAL SCIENCES, ISSN: 0022-510X, DOI: 10.1016/j.jns.2016.07.008, Vol.368, pp.155-159, 2016
Sliwinska A., Kwiatkowski D., Czarny P., Toma M., Wigner P., Drzewoski J., Fabianowska-Majewska K., Szemraj J., Maes M., Gałecki P., Śliwiński T., The levels of 7,8-dihydrodeoxyguanosine (8-oxoG) and 8-oxoguanine DNA glycosylase 1 (OGG1) - A potential diagnostic biomarkers of Alzheimer's disease, JOURNAL OF THE NEUROLOGICAL SCIENCES, ISSN: 0022-510X, DOI: 10.1016/j.jns.2016.07.008, Vol.368, pp.155-159, 2016

Abstract:
Evidence indicates that oxidative stress contributes to neuronal cell death in Alzheimer's disease (AD). Increased oxidative DNA damage I, as measured with 8-oxoguanine (8-oxoG), and reduced capacity of proteins responsible for removing of DNA damage, including 8-oxoguanine DNA glycosylase 1 (OGG1), were detected in brains of AD patients. In the present study we assessed peripheral blood biomarkers of oxidative DNA damage, i.e. 8-oxoG and OGG1, in AD diagnosis, by comparing their levels between the patients and the controls. Our study was performed on DNA and serum isolated from peripheral blood taken from 100 AD patients and 110 controls. For 8-oxoG ELISA was employed. The OGG1 level was determined using ELISA and Western blot technique. Levels of 8-oxoG were significantly higher in DNA of AD patients. Both ELISA and Western blot showed decreased levels of OGG1 in serum of AD patients. Our results show that oxidative DNA damage biomarkers detected in peripheral tissue could reflect the changes occurring in the brain of patients with AD. These results also suggest that peripheral blood samples may be useful to measure oxidative stress biomarkers in AD.

Keywords:
Alzheimer's disease, Oxidative stress, Oxidative DNA damage, 7 8-dihydrodeoxyguanosine (8-oxoG), DNA base excision repair, 8-oxoguanine DNA glycosylase 1 (OGG1)

(25p.)
46.Kwiatkowski D., Czarny P., Toma M., Korycinska A., Sowinska K., Gałecki P., Bachurska A., Bielecka-Kowalska A., Szemraj J., Maes M., Śliwiński T., Association between single nucleotide polymorphisms of hOGG1, NEIL1, APEX1, FEN1, LIG1 and LIG3 genes and Alzheimer’s disease risk, NEUROPSYCHOBIOLOGY, ISSN: 0302-282X, DOI: 10.1159/000444643, Vol.73, No.2, pp.98-107, 2016
Kwiatkowski D., Czarny P., Toma M., Korycinska A., Sowinska K., Gałecki P., Bachurska A., Bielecka-Kowalska A., Szemraj J., Maes M., Śliwiński T., Association between single nucleotide polymorphisms of hOGG1, NEIL1, APEX1, FEN1, LIG1 and LIG3 genes and Alzheimer’s disease risk, NEUROPSYCHOBIOLOGY, ISSN: 0302-282X, DOI: 10.1159/000444643, Vol.73, No.2, pp.98-107, 2016

Abstract:
Background: One of the factors that contribute to Alzheimer's disease (AD) is the DNA damage caused by oxidative stress and inflammation that occurs in nerve cells. It has been suggested that the risk of AD may be associated with an age dependent reduction of the DNA repair efficiency. Base excision repair (BER) is, among other things, a main repair system of oxidative DNA damage. One of the reasons for the reduced efficiency of this system may be single-nucleotide polymorphisms (SNP) of the genes encoding its proteins. Methods: DNA for genotyping was obtained from the peripheral blood of 281 patients and 150 controls. In the present study, we evaluated the impact of 8 polymorphisms of 6 BER genes on the AD risk. We analyzed the following SNP: c.-468T>G and c.444T>G of APEX1, c.*50C>T and c.*83A>C of LIG3, c.977C>G of OGG1, c.*283C>G of NEIL1, c.-441G>A of FEN1, and c.-7C>T of LIG1. Results: We showed that the LIG1 c.-7C>T A/A and LIG3 c.*83A>C A/C variants increased, while the APEX1 c.444T>G G/T, LIG1 c.-7C>T G/, LIG3 c.*83A>C C/C variants reduced, the AD risk. We also evaluated the relation between gene-gene interactions and the AD risk. We showed that combinations of certain BER gene variants such as c.977C>Gxc.*50C>T CC/CT, c./111T>Gxc.*50C>T GG/CT, c.-468T>Gxc.*50C>T GG/CT, c.-441G>Ac.*50C>Txc.*50C>T GG/CT, c.*83A>Cx c.*50C>T CT/AC, and c.-7C>Txc.*50C>T CT/GG can substantially positively modulate the risk of AD. Conclusions: In conclusion, we revealed that polymorphisms of BER genes may have a significant effect on the AD risk, and the presence of polymorphic variants may be an important marker for AD.

Keywords:
Alzheimer's disease, Base excision repair, Polymorphisms

(25p.)
47.Czarny P., Kwiatkowski D., Toma M., Gałecki P., Orzechowska A., Bobińska K., Bielecka-Kowalska A., Szemraj J., Berk M., Anderson G., Śliwiński T., Single-nucleotide polymorphisms of genes involved in repair of oxidative DNA damage and the risk of recurrent depressive disorder, Medical Science Monitor, ISSN: 1643-3750, DOI: 10.12659/MSM.898091, Vol.22, pp.4455-4474, 2016
Czarny P., Kwiatkowski D., Toma M., Gałecki P., Orzechowska A., Bobińska K., Bielecka-Kowalska A., Szemraj J., Berk M., Anderson G., Śliwiński T., Single-nucleotide polymorphisms of genes involved in repair of oxidative DNA damage and the risk of recurrent depressive disorder, Medical Science Monitor, ISSN: 1643-3750, DOI: 10.12659/MSM.898091, Vol.22, pp.4455-4474, 2016

Abstract:
Background: Depressive disorder, including recurrent type (rDD), is accompanied by increased oxidative stress and activation of inflammatory pathways, which may induce DNA damage. This thesis is supported by the presence of increased levels of DNA damage in depressed patients. Such DNA damage is repaired by the base excision repair (BER) pathway. BER efficiency may be influenced by polymorphisms in BER-related genes. Therefore, we genotyped nine single-nucleotide polymorphisms (SNPs) in six genes encoding BER proteins.

Material/Methods: Using TaqMan, we selected and genotyped the following SNPs: c.-441G>A (rs174538) of FEN1, c.2285T>C (rs1136410) of PARP1, c.580C>T (rs1799782) and c.1196A>G (rs25487) of XRCC1, c.*83A>C (rs4796030) and c.*50C>T (rs1052536) of LIG3, c.-7C>T (rs20579) of LIG1, and c.-468T>G (rs1760944) and c.444T>G (rs1130409) of APEX1 in 599 samples (288 rDD patients and 311 controls).

Results: We found a strong correlation between rDD and both SNPs of LIG3, their haplotypes, as well as a weaker association with the c.-468T>G of APEXI which diminished after Nyholt correction. Polymorphisms of LIG3 were also associated with early onset versus late onset depression, whereas the c.-468T>G polymorphism showed the opposite association.

Conclusions: The SNPs of genes involved in the repair of oxidative DNA damage may modulate rDD risk. Since this is an exploratory study, the results should to be treated with caution and further work needs to be done to elucidate the exact involvement of DNA damage and repair mechanisms in the development of this disease.

Keywords:
Depression, DNA Repair, Inflammation, Oxidative Stress, Polymorphism, Single Nucleotide

(15p.)
48.Kosny J., Curcija Ch., Fontanini A., Kossecka E., A New Approach for Analysis of Complex Building Envelopes in Whole Building Energy Simulations, Buildings XIII - Thermal Performance of the Exterior Envelope of Whole Buildings Conference, 2016-09-04/09-08, Clearwater Beach, FL (US), pp.1-26, 2016
Kosny J., Curcija Ch., Fontanini A., Kossecka E., A New Approach for Analysis of Complex Building Envelopes in Whole Building Energy Simulations, Buildings XIII - Thermal Performance of the Exterior Envelope of Whole Buildings Conference, 2016-09-04/09-08, Clearwater Beach, FL (US), pp.1-26, 2016

Abstract:
The ability for reduction of whole-building energy consumption depends, in large scales, from correct predictions of building thermal loads with the building’s envelope characteristics being one of the most important factors. Since most of today’s building envelopes are complex three-dimensional networks of structural, insulation, and finish materials, the potential for correct predictions of their thermal performance depends on availability of acceptable, scientifically valid, consensus procedures for accurately implementing a building’s envelope thermal characteristics into whole-building energy simulation programs.
This paper is discusses a joint LBNL and Fraunhofer CSE project, focused on the upgrade of the already existing THERM program and its integration with EnergyPlus, a whole-building energy simulation tool. It is expected that these two programs, combined together, will eliminate typical analytical limitations of most of existing whole building energy tools, capable to simulate only simplified one-dimensional envelopes. The main research challenge is the design of an easy to implement upgrade of the THERM numerical tool to allow analysis of complex building envelope structures. The new version of THERM needs to be able to modify thermal characteristics of the complex three-dimensional (3-D) wall assemblies, in a way to enable their use in whole building energy simulation programs. It will be achieved through an application of the unique theoretical procedure, which will allow a generation of the simplified one-dimensional (1-D) wall geometry and material characteristics to fully and accuratly capture the dynamic effects of thermal bridges.
At this stage of the project, the research team focuses on development of theoretical bases for necessary changes in the THERM framework. This paper explains the theoretical methodology which is used and presents some results from the series of steady-state and dynamic heat transfer simulations performed on building envelopes architectural components, to illustrate the accuracy limitations associated with thermal calculation methods recommended by building energy codes worldwide.

49.Mikułowski G., Fournier M., Porchez T., Belly C., Claeyssen F., Semi-Passive Vibration Control Technique via Shunting of Amplified Piezoelectric Actuators, ACTUATOR 2016, 15th International Conference on New Actuators, 2016-06-13/06-15, Bremen (DE), pp.542-546, 2016
Mikułowski G., Fournier M., Porchez T., Belly C., Claeyssen F., Semi-Passive Vibration Control Technique via Shunting of Amplified Piezoelectric Actuators, ACTUATOR 2016, 15th International Conference on New Actuators, 2016-06-13/06-15, Bremen (DE), pp.542-546, 2016

Abstract:
The objective of this paper is to provide results of an experimental and analytical investigation of Amplified Piezoelectric Actuators (APA) as vibrational isolator in a configuration of a mechanical Single Degree of Freedom system. The investigation is aimed at assessment of the mechanical properties modification ability via shunting techniques. The investigation consist of a phenomenological modelling of the APAs considered as generators and experimental verification of the vibrational energy dissipation ability in frequency domain. The results obtained during this investigation reveal that it is feasible to receive more than 20 dB reduction of the displacement amplification in the resonant range. Moreover, three tested examples of APA reveal up to 9 % of resonant frequency shift due to proper adjustment of the electronic shunting circuit, which is an encouragement for further analyses towards application of the APAs in semi-passive vibration control applications.

Keywords:
Vibration, Dissipation, Adaptive, Piezoelectric

50.Czarny P., Kwiatkowski D., Gałecki P., Talarowska M., Orzechowska A., Bobińska K., Bielecka-Kowalska A., Szemraj J., Maes M., Su K.P., Śliwiński T., Association between single nucleotide polymorphisms of MUTYH, hOGG1 and NEIL1 genes, and depression, JOURNAL OF AFFECTIVE DISORDERS, ISSN: 0165-0327, DOI: 10.1016/j.jad.2015.05.044, Vol.184, pp.90-96, 2015
Czarny P., Kwiatkowski D., Gałecki P., Talarowska M., Orzechowska A., Bobińska K., Bielecka-Kowalska A., Szemraj J., Maes M., Su K.P., Śliwiński T., Association between single nucleotide polymorphisms of MUTYH, hOGG1 and NEIL1 genes, and depression, JOURNAL OF AFFECTIVE DISORDERS, ISSN: 0165-0327, DOI: 10.1016/j.jad.2015.05.044, Vol.184, pp.90-96, 2015

Abstract:
Background: An elevated levels oxidative modified DNA bases and a decreased efficiency of oxidative DNA damage repair were found in patients with depression disorders, including recurrent type (rDD). The glycosylases are involved in base excision repair (BER), which eliminates oxidative DNA damage. Therefore, we genotyped the single nucleotide polymorphisms (SNPs) of genes encoding three glycosylases: hOGG1, MUTYH and NEILL

Methods: We selected three polymorphisms: c.977C > G - hOGG1 (rs1052133), c.972G > C - MUTYH (rs3219489) and c.*589G > C - NEIL1 (rs4462560). A total of 555 DNA samples (257 cases and 298 controls) were genotyped using TaqMan probes.

Results: The C/C genotype and allele C of the c.*589G > C decreased the risk of rDD occurrence, while the G/G genotype and allele G of the same SNP increased the risk. This polymorphism had a stronger association with early-onset depression (patients with first episode <35 years of age) than with late onset depression (first episode >= 35 years of age). We did not find any significant differences in distribution of alleles and genotypes of other SNPs; however, the G/G genotype of the c.972G > C increased the risk of late onset rDD. We also found that combined genotype C/C-C/C of c.977C > G and c.*589G > C significantly reduced the risk of rDD.

Limitations: Limited sample size and ethnic homogeneity of the studied population.

Conclusion: This is the first study to show that SNPs of genes involved in DNA repair, particularly in BER pathway, may modulate the risk of rDD. These results further support the hypothesis on the involvement of DNA repair mechanisms in pathogenesis of depression.

Keywords:
Depression, Glycosylases, BER, DNA repair, DNA damage

(35p.)
51.Kwiatkowski D., Czarny P., Gałecki P., Bachurska A., Talarowska M., Orzechowska A., Bobińska K., Bielecka-Kowalska A., Pietras T., Szemraj J., Maes M., Śliwiński T., Variants of Base Excision Repair Genes MUTYH, PARP1 and XRCC1 in Alzheimer's Disease Risk, NEUROPSYCHOBIOLOGY, ISSN: 0302-282X, DOI: 10.1159/000381985, Vol.71, No.3, pp.176-186, 2015
Kwiatkowski D., Czarny P., Gałecki P., Bachurska A., Talarowska M., Orzechowska A., Bobińska K., Bielecka-Kowalska A., Pietras T., Szemraj J., Maes M., Śliwiński T., Variants of Base Excision Repair Genes MUTYH, PARP1 and XRCC1 in Alzheimer's Disease Risk, NEUROPSYCHOBIOLOGY, ISSN: 0302-282X, DOI: 10.1159/000381985, Vol.71, No.3, pp.176-186, 2015

Abstract:
Background: Many clinical studies have shown that oxidative stress pathways and the efficiency of the oxidative DNA damage base excision repair (BER) system are associated with the pathogenesis of Alzheimer's disease (AD). Reduced BER efficiency may result from polymorphisms of BER-related genes. In the present study, we examine whether single nucleotide polymorphisms (SNPs) of BER genes are associated with increased risk of AD. Methods: SNP genotyping was carried out on DNA isolated from peripheral blood mononuclear cells obtained from 120 patients with AD and 110 healthy volunteers. Samples were genotyped for the presence of BER-related SNPs, i.e.XRCC1-rs1799782, rs25487; MUTYH-rs3219489, and PARP1-rs1136410. Results: We found a positive association between AD risk and the presence of G/A genotype variant of the XRCC1 rs25487 polymorphism [odds ratio (OR) = 3.762,95% Cl: 1.793-7.8911. The presence of the A/A genotype of this polymorphism reduced the risk of AD (OR = 0.485,95% Cl: 0.271-0.870). In cases of the PARP1 gene rs1136410 polymorphism, we observed that the T/C variant increases (OR =4.159, 95% Cl: 1.978-8.745) while the T/T variant reduces risk (OR = 0.240,95% Cl: 0.114-0.556) of AD. Conclusions: We conclude that BER gene polymorphisms may play an important role in the etiology of AD. Diagnosing the presence or absence of particular genetic variants may be an important marker of AD. Further research on a larger population is needed. There is also a need to examine polymorphisms of other BER in the context of AD risk.

Keywords:
Alzheimer's disease, Base excision repair, Polymorphisms

(25p.)
52.Śliwińska A., Kwiatkowski D., Czarny P., Milczarek J., Toma M., Korycinska A., Szemraj J., Śliwiński T., Genotoxicity and cytotoxicity of ZnO and Al2O3 nanoparticles, TOXICOLOGY MECHANISMS AND METHODS, ISSN: 1537-6516, DOI: 10.3109/15376516.2015.1006509, Vol.25, No.3, pp.176-183, 2015
Śliwińska A., Kwiatkowski D., Czarny P., Milczarek J., Toma M., Korycinska A., Szemraj J., Śliwiński T., Genotoxicity and cytotoxicity of ZnO and Al2O3 nanoparticles, TOXICOLOGY MECHANISMS AND METHODS, ISSN: 1537-6516, DOI: 10.3109/15376516.2015.1006509, Vol.25, No.3, pp.176-183, 2015

Abstract:
Objectives: Metal oxide nanoparticles (ZnO-NPs and Al2O3-NPs) are used in many fields, including consumer products and biomedical applications. As a result, exposure to these NPs is highly frequent, however, no conclusive information on their potential cytotoxicity and genotoxicity mechanisms are available. For this reason, we studied cytotoxic and genotoxic effects of ZnO-NPs and Al2O3-NPs on human peripheral blood lymphocytes.

Materials and methods: We obtained our goals by using MTT assay, Annexin V-FITC flow cytometry, and alkaline, neural and pH 12.1 versions of comet assay.

Results: Exposure of lymphocytes to both NPs for 24 h slightly decreased viability of lymphocytes at >= 0.5 mM. For the first time, we revealed using the comet assays that both ZnO-NPs and Al2O3-NPs caused a concentration-dependent increase of DNA single-strand breaks, but not alkali-labile sites. Treatment with DNA glycosylases showed that the NPs induced oxidative DNA damage. DNA damage caused by both nanoparticles at 0.05 mM was removed within 120 min, however lymphocytes did not repair DNA damage induced by 0.5 mM NPs. Studied nanoparticles did not induce apoptosis in lymphocytes.

Conclusion: Our results suggest that ZnO-NPs and Al2O3-NPs at concentration up to 0.5 mM did not exhibit cytotoxic effect but may exert genotoxic effect on lymphocytes, at least partially by the generation of oxidative DNA damage and strand breaks.

Keywords:
DNA repair, oxidative DNA damage, single and double strand breaks

(15p.)
53.Czarny P., Kwiatkowski D., Kacperska D., Kawczyńska D., Talarowska M., Orzechowska A., Bielecka-Kowalska A., Szemraj J., Gałecki P., Śliwiński T., Elevated Level of DNA Damage and Impaired Repair of Oxidative DNA Damage in Patients with Recurrent Depressive Disorder, Medical Science Monitor, ISSN: 1643-3750, DOI: 10.12659/MSM.892317, Vol.21, pp.412-418, 2015
Czarny P., Kwiatkowski D., Kacperska D., Kawczyńska D., Talarowska M., Orzechowska A., Bielecka-Kowalska A., Szemraj J., Gałecki P., Śliwiński T., Elevated Level of DNA Damage and Impaired Repair of Oxidative DNA Damage in Patients with Recurrent Depressive Disorder, Medical Science Monitor, ISSN: 1643-3750, DOI: 10.12659/MSM.892317, Vol.21, pp.412-418, 2015

Abstract:
Background: Depressive disorder (DD), including recurrent DD (rDD), is a severe psychological disease, which affects a large percentage of the world population. Although pathogenesis of the disease is not known, a growing body of evidence shows that inflammation together with oxidative stress may contribute to development of DD. Since reactive oxygen species produced during stress may damage DNA, we wanted to evaluate the extent of DNA damage and efficiency of DNA repair in patients with depression.

Material/Methods: We measured and compared the extent of endogenous DNA damage - single- and double-strand breaks, alkali-labile sites, and oxidative damage of the pyrimidines and purines - in peripheral blood mononuclear cells isolated from rDD patients (n=40) and healthy controls (n=46) using comet assay. We also measured DNA damage evoked by hydrogen peroxide and monitored changes in DNA damage during repair incubation.

Results: We found an increased number DNA breaks, alkali-labile sites, and oxidative modification of DNA bases in the patients compared to the controls. Exposure to hydrogen peroxide evoked the same increased damage in both groups. Examination of the repair kinetics of both groups revealed that the lesions were more efficiently repaired in the controls than in the patients.

Conclusions: For the first time we showed that patients with depression, compared with non-depresses individuals, had more DNA breaks, alkali-labile sites, and oxidative DNA damage, and that those lesions may be accumulated by impairments of the DNA repair systems. More studies must be conducted to elucidate the role of DNA damage and repair in depression.

Keywords:
Depression, DNA Damage, DNA Repair, Oxidative Stress, Reactive Oxygen Species

(15p.)
54.Kwiatkowski D., Śliwiński T., Naprawa DNA przez wycinanie zasad azotowych w chorobie Alzheimera, POSTĘPY HIGIENY I MEDYCYNY DOŚWIADCZALNEJ, ISSN: 0032-5449, DOI: 10.5604/17322693.1114036, Vol.68, pp.976-986, 2014
Kwiatkowski D., Śliwiński T., Naprawa DNA przez wycinanie zasad azotowych w chorobie Alzheimera, POSTĘPY HIGIENY I MEDYCYNY DOŚWIADCZALNEJ, ISSN: 0032-5449, DOI: 10.5604/17322693.1114036, Vol.68, pp.976-986, 2014

Abstract:
Choroba Alzheimera (AD - Alzheimer Disease), jest najczęstszą chorobą neurodegeneracyjną u ludzi powyżej 65 roku życia. Szacunkowe dane podają, że na AD w Polsce choruje prawie 200 tys. osób, natomiast na świecie na ten typ schorzenia cierpi około 30 mln ludzi. Progno¬zy wskazują, że w krajach rozwiniętych liczba osób dotkniętych chorobami otępiennymi, w tym AD do 2025 r. wzrośnie od kilkudziesięciu do kilkuset procent w porównaniu do 1980 r. Patogeneza AD nadal nie została do końca wyjaśniona, a wyniki badań przeprowadzonych do tej pory sugerują jej wieloczynnikowość, w której istotną rolę odgrywają wiek oraz czyn-niki genetyczne i środowiskowe. Istnieją przesłanki wskazujące związek między oksydantami wprowadzającymi uszkodzenia do materiału genetycznego oraz zmniejszeniem aktywności enzymów odpowiedzialnych za ich naprawę, a zmianami neurodegeneracyjnymi. W pracy omówiono doniesienia literaturowe obejmujące związek między poziomem aktywności głów¬nego systemu usuwającego uszkodzenia oksydacyjne DNA, czyli systemu naprawy DNA przez wycinanie zasad azotowych (BER - Base Excision Repair) a występowaniem AD. Podkreśla się także istotną rolę zmienności w genach kodujących białka BER, w modulowaniu aktywności tego systemu naprawy DNA. Wskazuje to na możliwość poznania mechanizmu powstawania AD opartego o system BER, co w przyszłości może się przyczynić do określenia molekularnych markerów tego schorzenia.

Keywords:
choroba Alzheimera, oksydacyjne uszkodzenia DNA, naprawa DNA przez wycinanie zasad azotowych, polimorfizm genetyczny

(15p.)
55.Urban B., Engelmann P., Kossecka E., Kosny J., Arranging Insulation for Better Thermal Resistance in Concrete and Masonry Wall Systems, 9th Nordic Symposium on Building Physics – NBS 2011, 2011-05-29/06-02, Tampere (FI), No.3, pp.1-9, 2011
Urban B., Engelmann P., Kossecka E., Kosny J., Arranging Insulation for Better Thermal Resistance in Concrete and Masonry Wall Systems, 9th Nordic Symposium on Building Physics – NBS 2011, 2011-05-29/06-02, Tampere (FI), No.3, pp.1-9, 2011

Abstract:
This paper investigates how the spatial arrangement of thermal insulation influences the overall thermal resistance of concrete and masonry wall systems. Multi-dimensional finite difference modeling was used for this purpose. Concrete masonry units (CMUs) are commercially produced in various geometries and with different weight concretes. Although insulation inserts can increase a CMUs thermal performance, thermal bridging through the solid webbing of the CMUs can greatly reduce the effectiveness of the integrated insulation. Different commercially available CMU geometries and concrete weights were investigated using finite difference modeling to show the impact on overall CMU R-value and to determine the thermal efficiency of the insulation inserts.

Keywords:
thermal insulation, building envelope, masonry, concrete, thermal performance

56.Postek E., Design Sensitivity of a Tensegrity Model of a Tissue, CMM 2011, 19th International Conference on Computer Methods in Mechanics, 2011-05-09/05-12, Warszawa (PL), pp.1-6, 2011
Postek E., Design Sensitivity of a Tensegrity Model of a Tissue, CMM 2011, 19th International Conference on Computer Methods in Mechanics, 2011-05-09/05-12, Warszawa (PL), pp.1-6, 2011

Abstract:
The design sensitivity algorithm for visco-elastic tensegrity structures is presented. We adopt Updated Lagrangian formulation. We have possibility of grouping of the design variables what is particularly useful in the case of hierarchical structures. In our case, the structure is the tissue built of elementary cells. The design sensitivity procedure is implemented with parallel solver.

Keywords:
computational biology, tensegrity structures, design sensitivity

57.Postek E., Smallwood R., Hose R., Finite deformation based model of cytoskeleton, ICCB2009, IV International Congress on Computational Bioengineering including the first European Symposium on Biomedical Integrative Research , 2009-09-16/09-18, Bertinoro (IT), DOI: 10.6092/unibo/amsacta/2646, pp.53-53, 2009
Postek E., Smallwood R., Hose R., Finite deformation based model of cytoskeleton, ICCB2009, IV International Congress on Computational Bioengineering including the first European Symposium on Biomedical Integrative Research , 2009-09-16/09-18, Bertinoro (IT), DOI: 10.6092/unibo/amsacta/2646, pp.53-53, 2009

Abstract:
The cytoskeleto is modelled as a tensegrity structure. It consists of tendons and struts [Stamenovic, 2005]. The basic tensegrity structures are developed from icosahedron.
The cells undergo finite deformations behaviour and their response to loading conditions is visco-elastic,
These types of structures are sensitive to initial prestressing what it intuitively natural since without the initial stress state they would not exist, The other factors affecting the mechanical behaviour of the cell are constitutive parameters and positions of the nodes, in fact, the shape of the cell.

Keywords:
cytoskeleton, visco-elasticity, finite strains, prestressing

58.Postek E., Parallel version of a design sensitivity tensegrity code, TAM 2009, Transnational Access Meeting, HPC-Europa2 2009, 2009-10-14/10-16, Montpellier (FR), pp.1-1, 2009
Postek E., Parallel version of a design sensitivity tensegrity code, TAM 2009, Transnational Access Meeting, HPC-Europa2 2009, 2009-10-14/10-16, Montpellier (FR), pp.1-1, 2009

Abstract:
The cytoskeleton is a tensegrity structure, The mechanics is important to the cells: "change the mechanical stresses on cancer cells and they can start to behave like healthy ones" [1] . The displacements and stresses change in the biological materials due to the growth, division and death of the cells. The cells receive signals for the actions. This constitutes the agent-stress based models of the tissue. [1] C. Ainsworth. Stretvhing the examination, Nature, 456, Dec., 696-699, 2008.

Keywords:
cell mechanics, signals, design sensitivity

59.Postek E.W., Houseman G.A., Jimack P.K., Generic Models of Linear and Non-linear Visco-elastic Surface Deformation above a Fault, EGU 2008, European Geosciences Union General Assembly 2008, 2008-04-13/04-18, Vienna (AT), pp.1-1, 2008
Postek E.W., Houseman G.A., Jimack P.K., Generic Models of Linear and Non-linear Visco-elastic Surface Deformation above a Fault, EGU 2008, European Geosciences Union General Assembly 2008, 2008-04-13/04-18, Vienna (AT), pp.1-1, 2008

Abstract:
The ground displacements measured in the vicinity of a large strike-slip earthquake are
potentially important in diagnosing the state of stress on the fault and in the medium
surrounding. The co-seismic displacement is determined by the immediate elastic response
of the medium and the slip function on the fault-surface. The post-seismic
displacement is determined by a combination of post-seismic creep on the fault, viscoelastic
relaxation in the surrounding medium, and possibly poro-elastic deformation.
There are strong indications from previous earthquake studies that the visco-elastic
relaxation involves non-linear mechanisms, which produce faster deformation in the
early stages and slower deformation in the later stages than would occur with a linear
creep mechanism. In this study we examine a simplified model of a strike-slip fault
cutting a 3D block, and compute the surface displacement versus time functions for
a range of different constitutive relations. We examine linear and non-linear Maxwell
visco-elasticity, and compare with the generalized linear Maxwell visco-elasticity. The
effect of non-linearities in the elasticity (finite strain theory) is also considered.We use
the von Mises flow function in describing the non-linear Maxwell visco-elastic creep
models in which viscous creep strain-rate is proportional to the nth power of the deviatoric
stress (formulated using the 2nd invariant of the stress tensor). We describe
analytical solutions used to validate the 3D code, and then consider the effect of the
exponent n on the time histories of the surface displacement fields above the fault.
We aim here to compare these numerical models with observations from actual fault
systems obtained using InSAR and GPS data. Among the factors affecting the surface deformation patterns are near-surface layering, and lateral variation of material
properties, as well as irregularities on the fault surface. In principle, the comparison
of observations with theory should provide a better understanding of the physical response
of the sub-surface, together with a better understanding of the earthquake cycle
as it operates on specific fault systems.

Keywords:
surface deformation, seismic cycle, visco-elasticity, numerical models

60.Postek E.W., Houseman G.A., Jimack P.K., Aspects of Non-Newtonian Viscoelastic Deformation Produced by Slip on a Major Strike- slip Fault, AGU FALL MEETING 2008, American Geophysical Union Fall Meeting 2008, 2008-12-15/12-19, San Francisco (US), pp.1-1, 2008
Postek E.W., Houseman G.A., Jimack P.K., Aspects of Non-Newtonian Viscoelastic Deformation Produced by Slip on a Major Strike- slip Fault, AGU FALL MEETING 2008, American Geophysical Union Fall Meeting 2008, 2008-12-15/12-19, San Francisco (US), pp.1-1, 2008

Abstract:
Non-Newtonian flow occurs in crustal deformation processes on the long
timescales associated with large- scale continental deformation, and also
on the short time-scales associated with post-seismic deformation. The
co-seismic displacement is determined by the instantaneous elastic
response of the rocks on either side of the fault surface to the
distribution of slip on the surface of the fault. The post-seismic
deformation is determined by some combination of visco-elastic relaxation
of the medium and post-seismic creep on the fault. The response of the
crust may depend on elastic moduli, Poisson's ratio, temperature, pressure
and creep function parameters including stress exponent, activation
energy, activation volume and viscosity coefficient. We use the von Mises
function in describing the non-linear Maxwell visco-elastic creep models.
In this study we examine a model of a strike-slip fault crossing a 3D
block. The fault slips at time zero, and we solve for the viscoelastic
deformation field throughout the 3D volume using a 3D finite element
method. We perform parametric studies on the constitutive equation by
varying these parameters and the depth of the fault event. Our findings
are focused on the fact that the system is very sensitive to the above
mentioned parameters. In particular, the most important seems to be the
temperature profiles and stress exponent. The activation energy and the
pressure are of lower importance, however, they have their meaning. We
investigated the relaxation times and the deformation patterns. We took
the material properties as typical to dry quartzite and diabase. Depending
on the parameters the surface can be deformed permanently or the
deformation can decrease. We attempt to compare qualitatively the
calculated post-seismic response in terms of the post-seismic displacement
history of the earth's surface with InSAR patterns determined from recent
major strike-slip earthquakes. Quantitative comparison of the observations
with these numerical model results can in principle provide a better
understanding of the physical properties of the sub-surface and further
insight into the diagnostic properties of the earthquake cycles of major
fault systems.

Cite as: Author(s) (2008), Title, Eos Trans. AGU, 89(53), Fall Meet.
Suppl., Abstract T44B-07

Keywords:
rheology, crust, litosphere

61.Postek E.W., Houseman G.A., Jimack P.K., The effect of geometrical nonlinearity in visco-elastic deformation, EGU 2007, European Geosciences Union, General Assembly 2007, 2007-04-15/04-20, Vienna (AT), No.9, pp.03087-03087, 2007
62.Postek E., Houseman G.A., Jimack P.K., Nonlinear effects during post-seismic visco-elastic deformation, IUGG XXIV 2007, International Union of Geodesy and Geophysics General Assembly Earth, Our Changing Planet, 2007-07-02/07-13, Perugia (IT), No.JGS003, pp.207-207, 2007
Postek E., Houseman G.A., Jimack P.K., Nonlinear effects during post-seismic visco-elastic deformation, IUGG XXIV 2007, International Union of Geodesy and Geophysics General Assembly Earth, Our Changing Planet, 2007-07-02/07-13, Perugia (IT), No.JGS003, pp.207-207, 2007

Keywords:
deformation, viscosity, power law

63.Postek E., Houseman G.A., Jimack P.K., Surface deformation during earthquake cycle for a layered visco-elastic crust, Ada Lovelace Workshops on Modelling Mantle and Lithosphere Dynamics 10th International Workshop on Modeling of Mantle Convection and Lithospheric Dynamics, 2007-09-02/09-07, Carry-le-Rouet (FR), pp.1-1, 2007
Postek E., Houseman G.A., Jimack P.K., Surface deformation during earthquake cycle for a layered visco-elastic crust, Ada Lovelace Workshops on Modelling Mantle and Lithosphere Dynamics 10th International Workshop on Modeling of Mantle Convection and Lithospheric Dynamics, 2007-09-02/09-07, Carry-le-Rouet (FR), pp.1-1, 2007

Keywords:
surface deformation, viso-elasticity, seismic cycle

64.Ruterana P., Singh P., Kret S., Jurczak G., Maciejewski G., Dłużewski P., Cho H.K., Choi R.J., Lee H.J., Suh E.K., Quantitative evolution of the atomic structure of defects and composition fluctuations at the nanometer scale inside InGaN/GaN heterostructures, PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, ISSN: 0370-1972, Vol.241, No.12, pp.2643-2648, 2004
Ruterana P., Singh P., Kret S., Jurczak G., Maciejewski G., Dłużewski P., Cho H.K., Choi R.J., Lee H.J., Suh E.K., Quantitative evolution of the atomic structure of defects and composition fluctuations at the nanometer scale inside InGaN/GaN heterostructures, PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, ISSN: 0370-1972, Vol.241, No.12, pp.2643-2648, 2004

Abstract:
The cover picture of this issue depicts indium composition fluctuations in InGaN/GaN multi quantum wells. The coded color strain distribution (left) was derived from finite element method calculations of the strain relaxation process and high‐resolution transmission electron microscopy (HRTEM) image simulations, superimposed on the HRTEM image of the quantum wells. The possible corresponding shape and εxx strain profiles in the indium rich clusters (right) hint at a concentration close to pure InN in their core. The paper by Pierre Ruterana et al. [1] was presented at the 5th International Symposium on Blue Laser and Light Emitting Diodes (ISBLLED‐2004), held in Gyeongju, Korea, 15–19 March 2004.

Keywords:
HRTEM, quantum well, composition fluctuation, strain distribution