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Search results for: FRICTIONAL HEATING
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TESTING CONTRACTION AND THERMAL EXPANSION COEFFICIENT OF CONSTRUCTION AND MOULDING POLYMER COMPOSITES
PublicationThe paper presents results of systematic tests of contraction and thermal expansion coefficients of materials based on polymer composites. The information on the above material properties is essential both at the design stage and during the use of finished products. Components for the samples were selected in such a way as to represent typical materials used for production of construction and moulding elements. The performed tests...
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On the peculiarities of anti-plane surface waves propagation for media with microstructured coating
PublicationWe discuss new type of surface waves which exist in elastic media with surface energy. Here we present the model of a coating made of polymeric brush. From the physical point of view the considered model of surface elasticity describes a highly anisotropic surface coating. Here the surface energy model could be treated as 2D reduced strain gradient continuum as surface strain energy depends on few second spatial derivatives of...
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The Method of a Two-Level Text-Meaning Similarity Approximation of the Customers’ Opinions
PublicationThe method of two-level text-meaning similarity approximation, consisting in the implementation of the classification of the stages of text opinions of customers and identifying their rank quality level was developed. Proposed and proved the significance of major hypotheses, put as the basis of the developed methodology, notably about the significance of suggestions about the existence of analogies between mathematical bases of...
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Building Project and Project Team Characteristics For Creating Hybrid Management Processes
PublicationThis paper introduces a method of building the characteristic of Software Development Project. Project characteristic is determined on the basis of several factors such as the complexity of Software Development Project and Project Team, results of historical projects and information on processes and methodologies, which are implemented in analyzed organizations. Information on project complexity can be applied to many different...
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ANALYSIS OF THE POSSIBILITIES OF HIGH SPEED SHAFT BEARING SYSTEM DURABILITY INCREASE
PublicationDuring the operation of wind turbines with a gearbox of traditional configuration, a high failure rate of high-speed shaft bearings is observed. Such a high failures frequency is not reflected in standard bearing durability calculation methods, which can be attributed to atypical failure mechanism. To avoid observed problems in the 1.5 MW wind turbine, the modification of the existing bearing system is proposed. Multiple options,...
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Low-power device simulator for micro-energy measurement methods testing
PublicationThe paper presents low-power device simulator designed for testing of micro-energy measurement methods. Such kind methods can be used for evaluation of power systems based on Energy Harvesting. The device allows to set the current consumption characteristic over the time, thus making possible playing the role of different types of low-power devices e.g. simulating sensor network node.
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Situational Awareness Network for the Electric Power System: the Architecture and Testing Metrics
PublicationThe contemporary electric power system is highly dependent on Information and Communication Technologies which results in its exposure to new types of threats, such as Advanced Persistent Threats (APT) or Distributed-Denial-of-Service (DDoS) attacks. The most exposed components are Industrial Control Systems in substations and Distributed Control Systems in power plants. Therefore, it is necessary to ensure the cyber security of...
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Non-Wave Variations in Temperature Caused by Sound in a Chemically Reacting Gas
PublicationA weakly nonlinear generation of non-acoustic modes in the field of sound in a gas is considered. An exotericchemical reaction of A->B type, which takes place in a gas, may be reversible or not. Two types of sound areconsidered, low-frequency and high-frequency as compared with the characteristic time of a chemical reaction.For both these cases, the governing equations of non-acoustic modes are derived and conclusions of the efficiencyof...
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Problems of analytical determination of journal bearing bush fatigue strength estimates
PublicationProblems connected with determination of stress distribution in sliding layer of thinwalled bearing bushes, investigated in bearing fatigue test rigs, have been presented. Using an example of plain bearings tested in the fatigue machine SMOK (built at the Gdask University of Technology) problems with obtaining a convergence of iterative procedure for determining the fatigue strength estimators of bearing alloy surface layer are...
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Removal and speciation of heavy metals in the constructed wetland treating landfill leachate
PublicationThe results of heavy metals removal and speciation of metals at two treatment wetlands receiving landfill are discussed. The first TW is a surface flow facility consisting of 10 ponds. The next TW is a newly constructed pilot-scale facility consisting of three beds with alternately vertical and horizontal sub-surface flow. The metals concentrations were analysed in leachate(both TWs) and bottom sediments (surface flow TW). Seasonal...
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Testing the impact of simplifications adopted in models describing wave loads on ship
PublicationThe wave-ship system in naval architecture is generally assumed to be a linear one. This allows for the computation of a transfer function of ship response to waves including wave loads on ship. The transfer function and the wave spectral density function enable the development of the stochastic process of wave loads on ship, corresponding to the irregular wave generating that loads. If the mathematical models of wave load transfer...
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Testing the impact of simplifications adopted in models describing wave loads on ship
PublicationThe wave-ship system in naval architecture is generally assumed to be a linear one. This allows for the computation of a transfer function of ship response to waves including wave loads on ship. The transfer function and the wave spectral density function enable the development of the stochastic process of wave loads on ship, corresponding to the irregular wave generating that loads. If the mathematical models of wave load transfer...
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Structure of sol-gel derived Nb2O5 films for active coating devices
PublicationW artykule przedstawiono wyniki badań struktury cienkich warstw nb2o5 otrzymywanych metodą zol-żel. wytworzone warstwy charakteryzowano pod kątem zastosowania jako materiałów na aktywne pokrycia fotoniczne.
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Budesonide treatment of professional athletes and anti-doping testing- case studies
PublicationAccording to the World Anti-Doping Agency (WADA) Prohibited List, glucocorticosteroids are prohibited in competition and only when administered by oral, intravenous, intramuscular or rectal routes. Up to now, in order to differentiate whether glucocorticosteroids were administered by one of the prohibited routes or not, a specific reporting limit for urinary concentrations of parent compounds and their metabolites was established...
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Novel Analytic-Numerical Model of Free Convection: with Leading Edge Considered
PublicationA novel solution of the free convection boundary problem is represented in analytical form for velocity and temperature for an isothermal vertical plate, as an example. These fields are built as a Taylor Series in the x coordinate with coefficients as functions of the vertical coordinate (y). We restrict ourselves by cubic approximation for both functions. The basic Navier-Stokes and Fourier-Kirchhoff equations and boundary conditions...
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Modern Platform for Parallel Algorithms Testing: Java on Intel Xeon Phi
PublicationParallel algorithms are popular method of increasing system performance. Apart from showing their properties using asymptotic analysis, proof-of-concept implementation and practical experiments are often required. In order to speed up the development and provide simple and easily accessible testing environment that enables execution of reliable experiments, the paper proposes a platform with multi-core computational accelerator:...
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Bearing capacity of working platform using distinct layout optimization method
PublicationBearing capacity of the working platforms from sandy soil resting on NC and OC clays was analyzed using LimitState GEO program. Different failure modes are considered using distinct layout optimization (DLO) method, which forms the upper bound solution of limit state analysis. Different mechanisms of failure were observed as a function of the platform thickness, angle of internal friction of the platform material and undrained...
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Use of Neural Networks in Diagnostics of Rolling-Element Bearing of the Induction Motor
PublicationBearing defect is statistically the most frequent cause of an induction motor fault. The research described in the paper utilized the phenomenon of the current change in the induction motor with bearing defect. Methods based on the analysis of the supplying current are particularly useful when it is impossible to install diagnostic devices directly on the motor. The presented method of rolling-element bearing diagnostics used indirect...
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Model-based testing for execution algorithms in the simulation of cyber-physical systems
PublicationThe understanding of simulation semantics of a hybrid system is a challenge for computational engineers as it requires expertise in computer science, engineering, numerical methods, and mathematics at once. The testing methods for the execution of a simulation are being researched but not yet applied on the industrial level. Consequently, the semantics of the simulation becomes a critical artifact in the system development process....
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Characteristics of silver-dopped carbon nanotube coating destined for medical applications
PublicationCarbon nanotubes are materials demonstrating outstanding mechanical, chemical, and physical properties and are considered coatings of titanium implants. The present research is aimed to characterize the microstructure and properties of the multi-wall carbon nanotubes (MWCNTs) layer decorated with silver nanoparticles (Ag NPs) on the Ti13Nb13Zr alloy destined for long-term implants. The electrophoretic deposition of coatings...
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Testing the Effect of Bathymetric Data Reduction on the Shape of the Digital Bottom Model
PublicationDepth data and the digital bottom model created from it are very important in the inland and coastal water zones studies and research. The paper undertakes the subject of bathymetric data processing using reduction methods and examines the impact of data reduction according to the resulting representations of the bottom surface in the form of numerical bottom models. Data reduction is an approach that is meant to reduce the size...
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Direct design of Controlled Modulus Columns (CMC) based on in-situ testing
PublicationIn this paper, the serviceability limit state and bearing capacity of tension screw displacement piles were analyzed using the results of static pile load tests, carried out on the test plot near the Elbląg city, and field, and laboratory tests. The paper presents the methodology of determining the pile load-settlement curve using different types of t-z transfer functions. The new method of constructing the pile load-settlement...
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Estimation of Screw Displacement Pile-Bearing Capacity Based on Drilling Resistances
PublicationThis article presents an engineering, empiricalmethod of estimating the bearing capacity and settlementcharacteristics Q-s of screw displacement piles andcolumns, based on soil resistance encountered during thedrilling to form piles/columns in the ground. The methodwas developed on the basis of correlation analyses of thetest results of 24 piles made during the “DPDT-Auger”research project (Krasiński et al., 2022a). In the proposedmethod,...
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The use of GFRP tubes as load-bearing jackets in concrete-composite columns
PublicationThe paper presents the fields of applications of polymer composites in building structures. The use of composite glass fibre tubes is discussed in more detail. The laboratory methods used to test the mechanical properties of these pipes are presented. An original research program is presented, including six concrete-filled glass fibre tubes. The cylinders and columns made in this way were tested for their axial load capacity. Conclusions...
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Global value chains and wages under different wage setting mechanisms
PublicationThis study examines whether, and how, differences in wage bargaining schemes shape the relationship between global value chains (GVCs) and the wages of workers while considering both GVC participation and position in GVC. Our dataset is derived from the European Structure of Earnings Survey (SES), containing employee–employer data from 18 European countries, merged with sectoral data from the World Input-Output Database (WIOD)....
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Exploring DAD and ADD Methods for Dealing with Urban Heat Island Effect
PublicationThe Urban Heat Island (UHI) effect in the context of climate change and temperature fluctuations is an increasing challenge for contemporary cities. Numerous activities focus on mitigation and adaptation to the UHI effect using both appropriately selected design strategies and technological solutions. However, not all of these technologies support the postulates of ecological and low-carbon cities. Their design, implementation,...
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Aplication of impedance imaging to evaluation of organic coating degradation at a local scale
PublicationZaproponowano nowe podejście do oceny lokalnych właściwości elektrycznych powłok organicznych. Wykorzystuje ono mikroskop sił atomowych pracujący w trybie kontaktowym. Pomiędzy igłę mikroskopu i podłoże metalowe pokryte powłoką przykładany jest sinusoidalny napięciowy sygnał pobudzenia o zadanej częstotliwości i mierzony jest prądowy sygnał odpowiedzi. Zalety tego podejścia zostały zaprezentowane na przykładzie powłoki akrylowej...
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Beyond quid pro quo: good soldiers and characteristics of their helping behaviours
PublicationPurpose – Good soldiers are people who engage in citizenship behaviours “to do good” instead of “to look good”. The purpose of this article is to explore the motivations behind and the specific characteristics of behaviours of the good soldiers in the context of work using social exchange theory (SET) as a theoretical framework. Design/methodology/approach – 47 dyadic interviews with 94 individuals from three organisations...
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Can the Pandemic Be a Catalyst of Spatial Changes Leading Towards the Smart City?
PublicationThe worldwide spread of Covid‐19 infections has had a pervasive influence on cities and the lives of their residents. The current crisis has highlighted many urban problems, including those related to the functionality of urban structures, which directly affect the quality of life. Concurrently, the notion of “smart cities” is becoming a dominant trend in the discourse on urban development. At the intersection of these two phenomena,...
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Effect of electrode waterproof coating on quality of underwater wet welded joints
PublicationIn this paper, the effects of different hydrophobic coatings on the surface of covered electrodes on the quality of wet welded carbon steel joints were discussed. Commonly available hydrophobic substances used in industrial applications were selected for the research. The aim of using waterproof coatings was to check the possibility to decreasing the susceptibility of highstrength low-alloy S460N steel to cold cracking. During...
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Effect of interconnect coating procedure on solid oxide fuel cell performance
PublicationChromium (Cr) species vaporizing from chromia-forming alloy interconnects is known as a source of degradation in solid oxide fuel cell (SOFC) stacks called “cathode poisoning”. (Mn,Co)3O4 spinel coatings offer good protection against Cr evaporation during operation. In this study, Crofer 22 APU steel interconnects were electrophoretically deposited in different mediums to obtain high packing of green coating layer. The optimized...
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Testing Stability of Digital Filters Using Optimization Methods with Phase Analysis
PublicationIn this paper, novel methods for the evaluation of digital-filter stability are investigated. The methods are based on phase analysis of a complex function in the characteristic equation of a digital filter. It allows for evaluating stability when a characteristic equation is not based on a polynomial. The operation of these methods relies on sampling the unit circle on the complex plane and extracting the phase quadrant of a function...
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Creating a radiological database for automatic liver segmentation using artificial intelligence.
PublicationImaging in medicine is an irreplaceable stage in the diagnosis and treatment of cancer. The subsequent therapeutic effect depends on the quality of the imaging tests performed. In recent years we have been observing the evolution of 2D to 3D imaging for many medical fields, including oncological surgery. The aim of the study is to present a method of selection of radiological imaging tests for learning neural networks.
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Novel application of dynamic electrochemical impedance monitoring to a cataphoretic coating process
PublicationThe paper presents a novel method of on-line impedance monitoring of cataphoretic coating application process. Utilization of dynamic electrochemical impedance spectroscopy (DEIS) overcame the fundamental problem connected with non-stationarity of the aforementioned coating deposition process, which eliminates classical impedance spectroscopy technique from a real-time description of cataphoresis. The paper illustrates selected examples...
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In Vitro Biological Characterization of Silver-Doped Anodic Oxide Coating on Titanium
PublicationDespite the high biocompatibility and clinical effectiveness of Ti-based implants, surface functionalization (with complex osteointegrative/antibacterial strategies) is still required. To enhance the dental implant surface and to provide additional osteoinductive and antibacterial properties, plasma electrolytic oxidation of a pure Ti was performed using a nitrilotriacetic acid (NTA)-based Ag nanoparticles (AgNP)-loaded calcium–phosphate...
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Evaluation of expanded uncertainty of instantaneous power measurement in a bearing diagnostic system.
PublicationThe paper presents the issues concerning the estimation of the expanded uncertainty in the system for the diagnosis of rolling bearings, consisting of transducers: voltage and current voltage, which is used for diagnostic bearing motors method based on the measurement and analysis of the instantaneous power signal consumed by the induction motor. It presents the methodology for assessing the measurement uncertainty and presents...
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Requirements, modifications and methods of mechanical testing of bone cement – literature review
PublicationThe Aim of the paper is to show the basic requirements for the bone cement, its modifications in terms of physical, mechanical and biological properties and testing methods. This publication is intended to be a source of systematized basic knowledge regarding the modified bone cement.
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Pyrrole bearing diazocrowns: Selective chromoionophores for lead(II) optical sensing
PublicationDiazocrowns of 18-, 21- and 23-membered rings with pyrrole residue as a part of macrocycle were for the first time used as chromoionophores in lead(II) selective optodes. Sensing properties of optodes depend on the type of macrocycle, namely its size and the type of linker: oligoether or hydrocarbon chain. The best results were obtained for optode bearing 18-membered crown with oligoether linker showing linear response range of...
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Changes in Eating Behaviour during SARS-CoV-2 Pandemic among the Inhabitants of Five European Countries
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Centrally Pivoted Tilting Pad Thrust Bearing with Carbon-Based Coated Collar—Experimental Results of Low- and Medium-Speed Operation
PublicationExperimental results of the research on a tilting pad thrust bearing with symmetrical pad support in the conditions of high loads and low speeds are presented in the paper. As described in the literature review, experimental results of tilting pad bearings at low speed/high load regime and transient conditions are rare. Unusual material selection - steel pad against a DLC-type coating on the collar was utilized. Such material combination...
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Hydrogel Delivery System Containing Calendulae flos Lyophilized Extract with Chitosan as a Supporting Strategy for Wound Healing Applications
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The analgesic hybrid of dermorphin/substance P and analog of enkephalin improve wound healing in streptozotocin‐induced diabetic rats
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Structural evaluation of percolating, self-healing polyurethane–polycaprolactone blends doped with metallic, ferromagnetic, and modified graphene fillers
PublicationComposites with differently shaped micro- and nanofillers show various, unique thermal, and physicochemical properties when mixed with carefully chosen polymer matrix. Selected composition holds strategic value in achieving desired properties that is biodegradability, thermoelectric conductivity, and shape memory for organic coating. The main aim of this work is to briefly examine structural changes after reaching percolation...
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Autologous Platelet-Rich Plasma Reduces Healing Time of Chronic Venous Leg Ulcers: A Prospective Observational Study
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Observing its long-term effects on a short-term, multi-day evaluation of the effectiveness of hearing aid use
PublicationThe main objective of the research study was to develop a method for evaluating the effectiveness of hearing protection with hearing aids tailored to the needs and prevailing conditions in the acoustic environments where the elderly most often reside. The method was also intended to estimate the benefits of hearing aids and allow prediction of such an effect based on a short-term trial. It is noteworthy that a short-term evaluation...
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Structural evaluation of percolating, self-healing polyurethane–polycaprolactone blends doped with metallic, ferromagnetic, and modified graphene fillers
PublicationComposites with differently shaped micro- and nanofillers show various, unique thermal, and physicochemical properties when mixed with carefully chosen polymer matrix. Selected composition holds strategic value in achieving desired properties that is biodegradability, thermoelectric conductivity, and shape memory for organic coating. The main aim of this work is to briefly examine structural changes after reaching percolation threshold...
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Neotenic phenomenon in gene expression in the skin of Foxn1- deficient (nude) mice - a projection for regenerative skin wound healing
PublicationMouse fetuses up to 16 day of embryonic development and nude (Foxn1- deficient) mice are examples of animals that undergo regenerative (scar-free) skin healing. The expression of transcription factor Foxn1 in the epidermis of mouse fetuses begins at embryonic day 16.5 which coincides with the transition point from scar-free to scar-forming skin wound healing. In the present study, we tested the hypothesis that Foxn1 expression...
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Effects of surface texturing and kind of lubricant on the coefficient of friction at ambient and elevated temperatures
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Tribological and nanoscale research on model friction couples intended for hip joint prostheses
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Experimental Study of the Rolling Friction Coefficient in Highly Loaded Supports of Rotary Kilns
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