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Acoustics - new services for urban planning, research and education
PublicationThe main purpose of the presented design is twofold, namely: providing detailed information about the noise threats that occur every day in city areas and preventing the noise induced hearing loss especially among young people. An experimental system designed for the continuous monitoring of the acoustic climate of urban areas was developed and implemented within the PLGrid Plus project. The assessment of environmental threats...
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Larmor diamagnetism and Van Vleck paramagnetism in relativistic quantumtheory: the Gordon decomposition approach
PublicationWe consider a charged Dirac particle bound in a scalar potential perturbed by a classical magnetic field derivable from a vector potential A(r). Using a procedure based on the Gordon decomposition of a field-induced current, we identify diamagnetic and paramagnetic contributions to the second-order perturbationtheory correction to the particle's energy. In contradiction to earlier findings, based on the sum-over-states approach,...
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Fluctuation enhanced gas sensing with WO3-based nanoparticle gas sensors modulated by UV light at selected wavelengths
PublicationThe sensitivity and selectivity of WO3-based gas sensors can be enhanced by UV-irradiation-induced modulation, especially if different wavelengths are employed. We used fluctuation-enhanced gas sensing, based on measurements of resistance fluctuations in the gas sensor, to study the effects of such modulation on the noise intensity for ambient atmospheres of synthetic air without and with additions of small amounts of ethanol,...
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Analiza drgań kładki kompozytowej wywołanych działaniem wiatru
PublicationW pracy omówiono sposób przeprowadzenia uproszczonej, numerycznej analizy drgań kładki kompozytowej wywołanych działaniem wiatru. Rozważaniom poddano swobodnie podpartą konstrukcję o rozpiętości 16 m i przekroju w kształcie litery U. W pierwszej kolejności przeprowadzono dwuwymiarową analizę opływu niepodatnego kształtu przekroju kładki w poziomym strumieniu wiatru o prędkości 10 m/s. Obliczenia numeryczne przeprowadzono programem...
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Application and modelling of Shape-Memory Alloys for structural vibration control: State-of-the-art review
PublicationOne of the most essential components of structural design for civil engineers is to build a system that is resistant to environmental conditions such as harsh chemical environments, and catastrophic disasters like earthquakes and hurricanes. Under these circumstances and disturbances, conventional building materials such as steel and concrete may demonstrate inadequate performance in the form of corrosion, deterioration, oxidizing,...
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Method of selective fading as a educational tool to study the behaviour of prestressed concrete elements under excess loading
PublicationPrestressed structures are a key to realization of the boldest architectural ideas, characteristic feature of prestressed structure is better use of concrete material properties by insertion of internal forces. Learning about pre-stressed reinforced concrete structures is an integral part of Graduate Studies Program in construction engineering. Know-how of geometry change patterns in prestressed concrete elements under certain...
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Numerical analysis of pile installation effects in cohesive soils
PublicationIn this thesis the empirical equation for radial effective stress calculation after displacement pile installation and following consolidation phase has been proposed. The equation is based on the numerical studies performed with Updated Lagrangian, Arbitrary Lagrangian-Eulerian and Coupled Eulerian-Lagrangian formulations as well as the calibration procedure with database containing world-wide 30 pile static loading tests in cohesive...
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"Raport z wstępnych badań własności stali trudnościeralnej 460HB",. ang "Report on preliminary tests of the properties of wear-resistant steel 460HB"
PublicationMikrostrukturę badanej stali trudnościeralnej 460HB stanowi drobnoziarnisty martenzyt odpuszczony, który jest właściwy dla stali konstrukcyjnych niskowęglowych, niskostopowych ulepszonych cieplnie. W przypadku blach grubych, do których zalicza się badana stal, struktura może ulec zaburzeniu, jeżeli w hutniczym procesie wytwórczym wystąpiła niejednorodność odkształcenia plastycznego i w konsekwencji tworzenie się pasm segregacyjnych,...
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Inżynieria odwrotna bazy paliw płynnych w Gdańsku
PublicationArtykuł prezentuje prace z zakresu pozyskania danych o zbiornikach bazy paliw płynnych w Gdańsku. Przedstawione rozwiązanie nie ogranicza się tylko do stworzenia (rejestracji) chmury punktów, ale jest próbą wskazania użycia naziemnego skaningu laserowego do stworzenia bazy informacji o bazie paliw – w tym głównie geometrii zbiorników. Autorzy prezentują proces inwentaryzacji, rejestrację chmury punktów oraz wskazują zasady tworzenia...
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The luminescence study of Ga1.98–xAlxO3:0.02Cr3+ coumpounds.
Open Research DataA chemical and mechanical pressure-induced photoluminescence tuning method was developed through structural evolution and hydrostatic pressure involving phase transition. A series of Ga1.98−xAlxO3:0.02Cr3+ phosphors were synthesized by collaborators from National Taiwan University. Structural evolution reveals a crystal phase change with the incorporation...
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Formation of CN (B2∑+) radicals in the vacuum-ultraviolet photodissociation of pyridine and pyrimidine molecules
PublicationFormation of the excited CN(B2∑+) free radicals in the photodissociation of pyridine (C5H5N) and pyrimidine (C4H4N2) molecules was investigated over the energy ranges 16–27 and 14.7–25 eV, respectively. Photon-induced fluorescence spectroscopy was applied to detect the vibrationally and rotationally excited CN radicals by recording the B2∑+→X2∑+ emission bands (violet system). The measured dissociation yield curves demonstrate...
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Hydrogen migration in formation of NH(A3Π) radicals via superexcited states in photodissociation of isoxazole molecules
PublicationFormation of the excited NH(A 3Π) free radicals in the photodissociation of isoxazole (C3H3NO) molecules has been studied over the 14-22 eV energy range using photon-induced fluorescence spectroscopy. The NH(A 3Π) is produced through excitation of the isoxazole molecules into higher-lying superexcited states. Observation of the NH radical, which is not a structural unit of the isoxazole molecule, corroborates the hydrogen atom...
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PHOTON LUMINESCENCE STUDIES OF TETRAHYDROFURAN FOLLOWING TRIHYDROGEN CATIONS IMPACT IN THE 20–1000 EV ENERGY RANGE
PublicationPhoton emission arising during tetrahydrofuran (C4H8O, THF) fragmentation initiated by H3 + ion impact has been studied experimentally. Luminescence fragmentation spectra and the relative emission cross-sections of the excited fragments have been measured using collision-induced emission spectroscopy in the 20–1000 eV energy range. The main features in the spectra are the H Balmer series lines, whose intensities decrease with increasing...
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Functional phase bistability in a nanocrystalline RbMn[Fe(CN)6] thin film fabricated by matrix-assisted laser evaporation
PublicationOne of the main barriers hindering applications of Prussian blue metal assemblies is their poor processability, which makes the fabrication of intact thin films very difficult. In this work, a nanocrystalline RbMn[Fe(CN)6]·xH2O film on silicon substrate was obtained for the first time via laser-stimulated deposition and investigated. Temperature-induced phase transition and bistability within broad hysteresis loop (120 K), along...
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Application of Barkhausen effect in the impact assessment of welding to internal stress distribution in steel
PublicationThe paper presents identification method of internal stresses in plane steel elements in the chase of deliverance and welding assembly. The assessment was made by means of a non-destructive experimental method based on measurements incorporating local external magnetic field and the measurement of induced voltage, including Barkhausen noise. This method allows a degradation assessment due to internal and external actions, causing...
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Application of Barkhausen effect in the impact assessment of welding to internal stress distribution in steel
PublicationThe paper presents identification method of internal stresses in plane steel elements in the chase of deliverance and welding assembly. The assessment was made by means of a non-destructive experimental method based on measurements incorporating local external magnetic field and the measurement of induced voltage, including Barkhausen noise. This method allows a degradation assessment due to internal and external actions, causing...
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Structural properties of hypothetical CeBa2Cu3O7 compound from LSDA+DMFT calculations
PublicationThe hypothetical stoichiometric CeBa2Cu3O7 (Ce123) compound, which has not been synthesized as a single phase yet, was studied by the density functional theory (DFT). We utilized a method which merges the local spin density approximation (LSDA) with the dynamical mean-field theory (DMFT) to account for the electronic correlations. The LSDA+DMFT calculations were performed in the high-temperature range. The particular emphasis was...
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All graphs with paired-domination number two less than their order
PublicationLet G=(V,E) be a graph with no isolated vertices. A set S⊆V is a paired-dominating set of G if every vertex not in S is adjacent with some vertex in S and the subgraph induced by S contains a perfect matching. The paired-domination number γp(G) of G is defined to be the minimum cardinality of a paired-dominating set of G. Let G be a graph of order n. In [Paired-domination in graphs, Networks 32 (1998), 199-206] Haynes and Slater...
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Fundamentals of Communication Networks Resilience to Disasters and Massive Disruptions
PublicationCommunication networks are exposed to a variety of massive failure events following from activities of nature, weather-induced disruptions, technology-implied problems, and malicious human activities. In this chapter, we first highlight the characteristics of these scenarios and discuss example failure events reported during the last three decades. Next, we explain the concept of network resilience and present an overview of major...
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A variational approach of homogenization of piezoelectric composites towards piezoelectric and flexoelectric effective media
PublicationThe effective piezoelectric properties of heterogeneous materials are evaluated in the context of periodic homogenization, whereby a variational formulation is developed, articulated with the extended Hill macrohomogeneity condition. The entire set of homogenized piezoelectric moduli is obtained as the volumetric averages of the microscopic properties of the individual constituents weighted by the displacement and polarization...
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Effect of bitumen characteristics obtained according to EN and Superpave specifications on asphalt mixture performance in low-temperature laboratory tests
PublicationThe paper aims to identify those characteristics of bitumen which have the greatest impact on asphalt mixture low-temperature performance. It was observed that stiffness and m-value of bitumen from BBR test were moderately related to stiffness and m-value of asphalt mixture obtained from 3 PB test. Simultaneously those rheological properties significantly impact on cryogenic stresses induced during TSRST test. The multiple regression...
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Dynamics of fault arc traveling along busbars in high voltage switchboards = Dynamika łuku zwarciowego przemieszczającego się wzdłuż szyn rozdziel-nic wysokiego napięcia
PublicationThe paper presents the results of magnetic induction and electrodynamic force calculations acting on arc column during short-circuit in medium voltage air-insulated bus-bars. The gap between the bars was 120 mm and the prospective short-circuit currents ranged from 4 kA to 8 kA. The paper also shows the measurement results of average velocity fault arc depending on currents arc diameter and arc current was established and described....
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An isogeometric finite element formulation for geometrically exact Timoshenko beams with extensible directors
PublicationAn isogeometric finite element formulation for geometrically and materially nonlinear Timoshenko beams is presented, which incorporates in-plane deformation of the cross-section described by two extensible director vectors. Since those directors belong to the space R3, a configuration can be additively updated. The developed formulation allows direct application of nonlinear three-dimensional constitutive equations without zero...
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Testing of the longest span soil-steel bridge in Europe – new quality in measurements
PublicationThe article describes interdisciplinary and comprehensive diagnostic tests of final bridge inspection and acceptance proposed for a soil – steel bridge made of corrugated sheets, being the European span length record holder (25.74 m). As an effect of an original concept a detailed and precise information about the structure response was collected. The load test design was based on the nonlinear numerical simulations performed by...
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On dynamic modeling of piezomagnetic/flexomagnetic microstructures based on Lord–Shulman thermoelastic model
PublicationWe study a time-dependent thermoelastic coupling within free vibrations of piezomagnetic (PM) microbeams considering the flexomagnetic (FM) phenomenon. The flexomagneticity relates to a magnetic field with a gradient of strains. Here, we use the generalized thermoelasticity theory of Lord–Shulman to analyze the interaction between elastic deformation and thermal conductivity. The uniform magnetic field is permeated in line with...
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Hybrid all-cellulose reinforcement in polypropylene matrix biocomposites for injection moulding - influence of particle geometry and volume fraction on hybrid effect
PublicationThe presented study is focused on evaluation of influence of reinforcement volume fraction and geometry on the occurrence of positive hybrid effect by the hybridisation of man-made cellulose fibres (rayon viscose) with cellulose microparticle fillers applied in polypropylene matrix. Four volume fractions of reinforcement were used at 1:1 combination of short man-made cellulose fibres with cellulose microfillers of different aspect...
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Textile reinforced concrete members subjected to tension, bending, and in-plane loads: Experimental study and numerical analyses
PublicationTextile reinforced concrete has raised increasing research interest during the last years, mainly due to its potential to be used for freeform shell structures involving complex load situations. Yet, most experimental work has focused on test setups with primarily uniaxial loading. In the current work, such setups are complemented with a novel test setup of deep beams, including in-plane bending and shear. Further, nonlinear finite...
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Analytical predictions for the buckling of a nanoplate subjected to non-uniform compression based on the four-variable plate theory
PublicationIn the present study, the buckling analysis of the rectangular nanoplate under biaxial non-uniform compression using the modified couple stress continuum theory with various boundary conditions has been considered. The simplified first order shear deformation theory (S-FSDT) has been employed and the governing differential equations have been obtained using the Hamilton’s principle. An analytical approach has been applied to obtain...
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An isogeometric finite element formulation for frictionless contact of Cosserat rods with unconstrained directors
PublicationThis paper presents an isogeometric finite element formulation for nonlinear beams with impenetrability constraints, based on the kinematics of Cosserat rods with unconstrained directors. The beam cross-sectional deformation is represented by director vectors of an arbitrary order. For the frictionless lateral beam-to-beam contact, a surface-to-surface contact algorithm combined with an active set strategy and a penalty method...
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Effects of Surface Energy and Surface Residual Stresses on Vibro-Thermal Analysis of Chiral, Zigzag, and Armchair Types of SWCNTs Using Refined Beam Theory
PublicationIn this article, vibration characteristics of three different types of Single-Walled Carbon Nanotubes (SWCNTs) such as armchair, chiral, and zigzag carbon nanotubes have been investigated considering the effects of surface energy and surface residual stresses. The nanotubes are embedded in the elastic substrate of the Winkler type and are also exposed to low and high-temperature environments. A new refined beam theory namely, one-variable...
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Wyznaczenie obciążeń na poszycie okrętu wywołanych uderzeniem fal i uderzeniem w lód i ich wpływ na bezpieczeństwo okrętu
PublicationThe main problem is the vessels rather accurate determination of the hydrodynamic loads so-called hydroelasticity outside . This can be done by theoretical analysis , computer simulation or by experiment. This gives the hydrodynamic pressure distribution on the walls of the ship's hull and also on the walls of marine vessels .The most dangerous are the impact of extreme storm waves , the impact of the wharf and the impact zone...
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Corrosion and Cavitation Resistances of Low Alloy Steel After Frictional-Mechanical Treatment
PublicationPaper presents the results of the studies of wear, corrosion and cavitation resistances of the S355J2 low alloy medium carbon steel subjected to surface modification by friction-mechanical treatment, as tested in sea water simulated solution. To evaluate the effect of the surface treatment, the comparative studies of the corrosive properties of the steel before and after treatment have been considered. The treatment due to a severe...
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Point cloud based surface analysis of prestressed concrete element in exceeded state of serviceability
PublicationBy definition, serviceability state is characterized by the fact that despite meeting the requirements associated with carrying capacity, the object is not suitable for use. Serviceability limit state refers to factors, such as durability, overall stability, fire resistance, cracking, excessive vibration. Perfect examples of exceeded serviceability state are the improper vibration of a skyscraper, which inhabitants may suffer from...
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Investigation of the impact of ITRF2014/IGS14 on the positions of the reference stations in Europe
PublicationIn January 2017, the new realization of the International Terrestrial Reference Frame (ITRF) – ITRF2014, was released. Besides the higher accuracy and consistency of the new frame, an entirely new element – the post seismic deformation - was included. Moreover, the definition of the fundamental points has also been changed. All changes related to the new reference frame haveconsequences in the precise positioning using GNSS observations....
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Hybrid Finite Element Method Development for Offshore Structures’ Calculation with the Implementation of Industry Standards
PublicationIn the design process of offshore steel structures, it is typical to employ commercial calculation codes in which simulation and evaluation of results are performed on the basis of the available standards (e.g. API, DNV, Lloyds). The modeling and solution rely on finite element methods and cover the simulation of the structure’s properties along with the influence of the marine environment – sea currents, wave and wind loading,...
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Increased cytotoxicity of an unusual DNA topoisomerase II inhibitor compound C-1305 toward HeLa cells with downregulated PARP-1 activity results from re-activation of the p53 pathway and modulation of mitotic checkpoints
PublicationOur previous studies have shown that murine fibroblast cells, in which PARP-1 gene was inactivated by gene disruption, are extremely sensitive to triazoloacridone compound C-1305, an inhibitor of DNA topoisomerase II with unusual properties. Here, we show that pharmacological inhibition of PARP-1 activity by its inhibitor compound NU1025, sensitizes human cervical carcinoma HeLa cells to compound C-1305 compared to treatment with...
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The effect of metal cluster deposition route on structure and photocatalytic activity of mono- and bimetallic nanoparticles supported on TiO2 by radiolytic method
PublicationTiO2 (P25) was modified with small and relatively monodisperse mono- and bimetallic clusters (Ag, Pd, Pt, Ag/Pd, Ag/Pt and Pd/Pt) induced by radiolysis to improve its photocatalytic activity. The as-prepared samples were characterized by X-ray fluorescence spectrometry (XRF), photoluminescence spectrometry (PL), diffuse reflectance spectroscopy (DRS), X-ray powder diffractometry (XRD), scanning transition electron microscopy (STEM)...
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New 2-[(4-Amino-6-N-substituted-1,3,5-triazin-2-yl)methylthio]-N-(imidazolidin-2-ylidene)-4-chloro-5-methylbenzenesulfonamide Derivatives, Design, Synthesis and Anticancer Evaluation
PublicationIn the search for new compounds with antitumor activity, new potential anticancer agents were designed as molecular hybrids containing the structures of a triazine ring and a sulfonamide fragment. Applying the synthesis in solution, a base of new sulfonamide derivatives 20–162 was obtained by the reaction of the corresponding esters 11–19 with appropriate biguanide hydrochlorides. The structures of the compounds were confirmed...
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Teloxantron inhibits the processivity of telomerase with preferential DNA damage on telomeres
PublicationTelomerase reactivation is one of the hallmarks of cancer, which plays an important role in cellular immortalization and the development and progression of the tumor. Chemical telomerase inhibitors have been shown to trigger replicative senescence and apoptotic cell death both in vitro and in vivo. Due to its upregulation in various cancers, telomerase is considered a potential target in cancer therapy. In this study, we identified...
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Transport deficiency is the molecular basis of Candida albicans resistance to antifungal oligopeptides
Publication(FMDP), an inhibitor of glucosamine-6-phosphate synthase, exhibited growth inhibitory activity against Candida albicans, with minimal inhibitory concentration values in the 0.05–50 mg/L range. Uptake by the peptide permeases was found to be the main factor limiting an anticandidal activity of these compounds. Di- and tripeptide containing FMDP (F2 and F3) were transported by Ptr2p/Ptr22p peptide transporters (PTR) and FMDP-containing...
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Graph classes generated by Mycielskians
PublicationIn this paper we use the classical notion of weak Mycielskian M'(G) of a graph G and the following sequence: M'_{0}(G) =G, M'_{1}(G)=M'(G), and M'_{n}(G)=M'(M'_{n−1}(G)), to show that if G is a complete graph oforder p, then the above sequence is a generator of the class of p-colorable graphs. Similarly, using Mycielskian M(G) we show that analogously defined sequence is a generator of the class consisting of graphs for which the...
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Elimination and migration of hydrogen in the vacuum-ultraviolet photodissociation of pyridine molecules
PublicationElimination of the excited hydrogen atoms H(n), n = 4–7, and hydrogen migration in formation of the excited NH(A 3Π) free radicals in the photodissociation of pyridine, C5H5N, molecules have been studied over the 17.5–70 eV photon energy range. In the measurements the photon-induced fluorescence spectroscopy technique has been applied. Both fragments are produced through excitation of pyridine molecules into higher-lying superexcited...
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Unicyclic graphs with equal total and total outer-connected domination numbers
PublicationLet G = (V,E) be a graph without an isolated vertex. A set D ⊆ V (G) is a total dominating set if D is dominating and the in- duced subgraph G[D] does not contain an isolated vertex. The total domination number of G is the minimum cardinality of a total domi- nating set of G. A set D ⊆ V (G) is a total outer–connected dominating set if D is total dominating and the induced subgraph G[V (G)−D] is a connected graph. The total outer–connected...
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Kompensacja skoków ciśnienia w pompie tłoczkowej o zmiennej wydajności z rozrządem krzywkowym
PublicationPrzedmiotem rozprawy doktorskiej jest opis matematyczny, badania i symulacja mechanizmu kompensacji skoków ciśnienia w pompie tłoczkowej z rozrządem krzywkowym typu PWK. W rozprawie przedstawiono istniejące rozwiązania konstrukcyjne pomp tłokowych, kładąc szczególny nacisk na przedstawienie stosowanych w nich mechanizmów rozrządu i kompensacji skoków ciśnienia. Ponadto szczegółowo opisano budowę i zasadę działania pompy PWK będącej...
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Diagnostics of the tram track shape with the use of the global positioning satellite systems (GPS/Glonass) measurements with a 20 Hz frequency sampling
PublicationSatellite geodetic measurements used in the diagnosis of railway tracks require professional receivers and a very high frequency rate of data processing. It stems from a significant speed (10 km/h) kinematic measurements carried out during the passage of a measuring platform. The survey results (positions) of deformed railroad track have waveforms nature requiring additional processing methods and approximations. Due to the announcement...
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Fatigue Bending of V-Notched Cold-Sprayed FeCoCrNiMn Coatings
PublicationCold-spray coatings were produced by FeCoCrNiMn high-entropy alloy powders deposited on carbon steel substrate. The coatings were realized at intermediate temperature and high pressure (at 1100 °C and 7 MPa). The coating microstructure was characterized by scanning electron microscopy and X-ray diffraction, revealing a very dense deposition and high flattening ratio of the splatted particles. This had a large influence on the...
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Experimental and theoretical study on high-temperature creep of VT6 titanium alloy under multi-axial loading conditions
PublicationIn the framework of damage mechanics, we discuss a new mathematical model that describes the kinetics of the stress–strain state and damage accumulation during material degradation by the mechanism of long-term strength under complex multiaxial stress state. An experimental and theoretical technique is proposed for determination of material parameters and scalar constitutive functions for damaged media based on specially set experiments...
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Strain-dependent behaviour of cold recycled material mixtures in cyclic compression tests
PublicationThe purpose of the study is to evaluate strain-dependent behaviour of Cold Recycled Material (CRM) mixtures using three frameworks typically applied for Hot Mix Asphalt (HMA): linear viscoelastic (LVE) limits; non-linearity directions; changes in rheological model parameters. To this aim, the complex modulus of three CRM mixtures with different bitumen-to-cement ratio (0.2, 0.6 and 1.8) was measured in cyclic compression mode,...
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Degradation of implantable materials – in vivo and in vitro research
PublicationThe article concerns the biological and electrochemical degradation of metallic implants in vivo and in vitro studies. The in vivo research dealt with degradation of plates used to join bones, as well as endoprostheses. The most common damages were: metalosis, breaking in the microstructure changes, breaking in area of holes, as well as plastic deformation throughout the length of an implant. The material used for the research...
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Simulations of air and water flow in a model dike during overflow experiments
PublicationFlow in flood dikes, earth dams, and embankments occurs in variably saturated conditions, with pores of the earth material filled partly with water and partly with air. In routine engineering analysis, the influence of pore air is neglected and the air pressure is assumed equal to atmospheric. In some circumstances, for example, during overtopping of the dike by water, the effect of pore air on water flow and stability of the structure...