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Wyniki wyszukiwania dla: flag manifold
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Laboratoryjne badania oporu toczenia i temperatury opon do pojazdów specjalnych
PublikacjaW pracy przedstawiono wyniki laboratoryjnych badań oporu toczenia i temperatury opon do pojazdów specjalnych. Współczynnik oporu toczenia tych opon jest silnie uzależniony od ciśnienia pompowania. Po utracie nadciśnienia w oponie, gdy następuje styk wewnętrznej powierzchni bieżnika z wkładką Run-Flat, opór toczenia wzrasta około 7-8 razy w stosunku do sytuacji gdy ciśnienie pompowania jest wyregulowane do jazdy po drogach utwardzonych...
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Tribological Properties of Thermoplastic Materials Formed by 3D Printing by FDM Process
PublikacjaThe dataset entitled 3D printed ABS thermoplastic vs. steel. Dry sliding wear test in constant load & velocity ring on flat configuration. Test parameters: print layer thickness and orientation. Test symbol: 019_h_4 contains: the time base (expressed in seconds and minutes), the friction torque for sliding friction, rotational velocity of the counter – specimen (velocity of sliding), friction coefficient, load in the friction contact...
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Wykładnicze równanie Arrheniusa jako funkcja dojrzałości twardniejącego betonu
PublikacjaPoprawne określenie funkcji dojrzałości dla mieszanki betonowej warunkuje powodzenie szacowania wytrzymałości na ściskanie na bazie pomiarów temperatury in situ. W artykule omówiono zastosowanie równania Arrheniusa do opisu funkcji dojrzewania twardniejącego betonu. Szczególną uwagę zwrócono na zależności szybkości zachodzenia reakcji w odmiennych warunkach temperaturowych. Przedstawiono wyniki własnych badań na kostkach zaprawy...
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Mathematical analysis of a generalised p53-Mdm2 protein gene expression model
PublikacjaWe propose the generalisation of the p53-Mdm2 protein gene expression model introduced by Monk (2003). We investigate the stability of a unique positive steady state and formulate conditions which guarantee the occurrence of the Hopf bifurcation. We show that oscillatory behaviour can be caused not only by time lag in protein transcription process, but also can be present in the model without time delay. Moreover, we investigate...
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COMMENTS ON EXISTING ANALYTICAL SOLUTIONS TO THE WAVE-INDUCED CYCLIC RESPONSE OF A POROUS SEABED OF INFINITE THICKNESS
PublikacjaThis paper deals with the wave-induced cyclic response of a porous seabed (by means of oscillating parameters: pore-fluid pressure, soil displacement components, effective normal stress and shear stress components) due to a surface sinusoidal water-wave propagating over a seabed of infinite thickness. The main existing analytical solutions to the governing problem are critically discussed, pointing out their meaningful errors and...
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Activated Tungsten Inert Gas Weld Characteristics of P91 Joint for Advanced Ultra Supercritical Power Plant Applications
PublikacjaActivated Tungsten Inert Gas (A-TIG) welding, a variant of tungsten inert gas (TIG) welding, was used for welding P91. In Generation IV power plants, P91 welds are prone to premature failure due to the presence and formation of brittle phases and creep at high temperatures. When performing A-TIG welding, the flux composition plays a role in the reversal of the Marangoni flow in the weld pool, which ultimately determines the level...
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Effect of asymmetric fluid flow distribution on flow boiling in a microchannel heat sink – An experimental investigation
PublikacjaFlow boiling in microchannels is emerging as an exclusive cooling solution for miniaturized high-power electronic devices alongside having other high heat flux applications. Size miniaturization at microscale strangely increases heat transfer performance as well as flow boiling instabilities. Many flow boiling instabilities are interrelated and result from imperfect hydrodynamic conditions. One of such problems is flow maldistribution among...
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Sensorless algorithm for sustaining controllability of IPMSM drive in electric vehicle after resolver fault
PublikacjaThis paper presents a sensorless algorithm designated for the emergency control of an interior permanent magnet synchronous motor (IPMSM) drive in electric or hybrid vehicle. The algorithm is based on analysing the derivatives of motor phase currents measured over the duration of particular inverter states. The method is computationally simple and does not require additional hardware since the derivatives are measured indirectly....
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Comparative Study of the Reinforcement Type Effect on the Thermomechanical Properties and Burning of Epoxy-Based Composites
PublikacjaAramid (AF), glass (GF), carbon (CF), basalt (BF), and flax (FF) fibers in the form of fabrics were used to produce the composites by hand-lay up method. The use of fabrics of similar grammage for composites’ manufacturing allowed for a comprehensive comparison of the properties of the final products. The most important task was to prepare a complex setup of mechanical and thermomechanical properties, supplemented by fire behavior...
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How Specific Can We Be with k-NN Classifier?
PublikacjaThis paper discusses the possibility of designing a two stage classifier for large-scale hierarchical and multilabel text classification task, that will be a compromise between two common approaches to this task. First of it is called big-bang, where there is only one classifier that aims to do all the job at once. Top-down approach is the second popular option, in which at each node of categories’ hierarchy, there is a flat classifier...
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Image projection in Immersive 3D Visualization Laboratory
PublikacjaIn recent years, many centers in the world attempted to build a virtual reality laboratory. The main idea of such laboratory is to allow the user to “immerse” into and move in a computer-generated virtual world. In the paper, the underlying principles of the system of virtual reality (VR) are described. The selected implementations constructed by the research centers of the world are also presented. The cave automatic virtual environment...
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The determinants of morphology and properties of the nanohydroxyapatite coating deposited on the Ti13Zr13Nb alloy by electrophoretic techniqe
PublikacjaThe titanium and its alloys belong at present to the most preferred and commonly applied biomaterials for load- bearing implants. The surfaces of biomaterials are subjected to modification, including the hydroxyapatite coatings deposited in order to ensure corrosion resistance and better joining between an implant and a bone through the possibility of ingrowth bone into the coating. In this paper, the morphology and properties...
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Modulated crystal structures - periodicity in more than three dimensions
PublikacjaThe initial definition of a crystal was that it is an object with flat faces. When diffraction studies were developed it turned out that crystal consists of a highly ordered particles and it is possible to isolate a small unique part of their structure - a unit cell - and the definition has been changed to rely on this fact. Nowadays by a crystal we mean any solid having an essentially discrete diffraction diagram. It is because...
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ARRAY OF MINIJETS – THERMAL AND HYDRAULIC PHENOMENA IN BOUNDARY LAYER
PublikacjaPresented work considers flow and thermal phenomena occurring in the system consisting of minijets array and heated with constant heat flux surface. Numerical analyses, based on the mass, momentum and energy conservation laws, were conducted. Focus was placed on the proper model construction, in which turbulence and boundary layer modelling was crucial. Calculations were done for various mass flow rates. The main calculations were...
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Influence of Water-Induced Degradation of Polytetrafluoroethylene (PTFE)-Coated Woven Fabrics Mechanical Properties
PublikacjaThe impact of water-induced degradation on the mechanical properties of the chosen two PTFE-coated, glass threads woven fabrics is investigated in this paper. The paper begins with a survey of literature concerning the investigation and determination of coated woven fabric properties. The authors carried out the uniaxial tensile tests with an application of flat and curved grips to establish the proper values of the ultimate tensile...
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Seismic Response Analysis of Knee-Braced Steel Frames Using Ni-Ti Shape Memory Alloys (SMAs)
PublikacjaShape Memory Alloys (SMAs) are known as active materials that can be widely used for structural purposes due to their flag-shape behavior under loading and reloading. Their unique characteristics provided a potential solution for civil engi-neers especially to model buildings with the capability of dissipating seismic en-ergy. In this study, the main purpose is to explore the seismic behavior of Knee-Braced Frames (KBFs) and...
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Hydrothermal Cobalt Doping of Titanium Dioxide Nanotubes towards Photoanode Activity Enhancement
PublikacjaDoping and modification of TiO2 nanotubes were carried out using the hydrothermal method. The introduction of small amounts of cobalt (0.1 at %) into the structure of anatase caused an increase in the absorption of light in the visible spectrum, changes in the position of the flat band potential, a decrease in the threshold potential of water oxidation in the dark, and a significant increase in the anode photocurrent. The material...
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Utilization of Gaseous Carbon Dioxide and Industrial Ca-rich Waste for Calcium Carbonate Precipitation: A Review
PublikacjaTechnologies for the management of various types of waste and the production of useful products from them are currently widely studied. Both carbon dioxide and calcium-rich waste from various production processes are problematic wastes that can be used to produce calcium carbonate. Therefore, the purpose of this paper is to provide an overview about the state of the development of processes that use these two wastes...
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<i>N,N,N</i>-Trimethyl-N-(methyl 5-deoxy-2,3-<i>O</i>-isopropylidene-β-D-ribofuranosid-5- yl)ammonium 4-methylbenzenesulfonate sesquihydrate.
PublikacjaThe structure of the title compound, [C12H24NO4][C7H7O3S]·1.5H2O, contains alternating layers parallel to (001) of hydrophobic and polar character, stabilized by C-H...O hydrogen bonding. The furan ring adopts an envelope conformation with the C(OMe) atom as the flap, and the dioxolane ring is twisted about one of the O-C(methine) bonds. A comparison to related compounds is presented. The tosylate-O atoms were disordered over two...
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Method of managing drill cuttings from shale gas formations
PublikacjaProposed management method of drill cuttings involves recycling for the expanded clay production. A theoretical presentation of the possibility, choosing planning path based on similarity between the materials used in the manufacture of expanded clay and oily cuttings. Application for the main stages of manufacture of expanded clay production of drill cuttings from shale gas extraction. Introduced into circulation solid waste partly...
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Mathematical model of pennate muscle
PublikacjaThe purpose of this study is to create a new mathematical model of pennate striated skeletal muscle. This new model describes behaviour of isolated flat pennate muscle in two dimensions (2D) by taking into account that rheological properties of muscle fibres depend on their planar arrangement. A new mathematical model is implemented in two types: 1) numerical model of unipennate muscle (unipennate model); 2) numerical model of...
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THEORETICAL POTENTIAL OF HYDROGEN PRODUCTION FROM TEXTILES WASTES IN POMERANIAN REGION BY MEANS OF DARK FERMENTATION
PublikacjaModel has been developed for calculating theoretical mass of hydrogen produced from textile wastes by mean of dark fermentation. As vegetable fibres wastes were chosen two mostly used — cotton and linen (flax). As the synthethic carbohydrate rich fiber was chosen viscose. In the background there were introduced: problems of dark fermentation, characteristics of textile material structure. Additionally pathways of the process...
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Effective yttrium based coating for steel interconnects of solid oxide cells: Corrosion evaluation in steam-hydrogen atmosphere
PublikacjaThis work describes manufacture, analysis and test of a new well conducting corrosion-protection coating that can be applied on steel types with high chromium content. Electrolytic deposition of yttrium salts is used to form thin (<100 nm) coatings on both flat steel sheets (material: Crofer 22 APU) and its properties are proven on woven wire-meshes (materials from two different sources: SUS316 and SUS316L). The oxide scale on...
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Overheating of underground power cable line due to its partial exposition to solar radiation
PublikacjaCurrent-carrying capacity of underground power cable lines depends, among others, on thermal resistivity of the soil and cables layout: trefoil formation, flat formation with or without spacing. If conditions for heat transfer in the ground are favorable, the current-carrying capacity is relatively high. Therefore, it generates risk of the power cables overheating, if part of the cable line is located vertically in the air, to...
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Tensile failure study of 3D printed PLA using DIC technique and FEM analysis
PublikacjaThe paper presents the experimental and numerical study of the failure behaviour of Fused Filament Fabricated (FFF) Polylactic Acid (PLA) samples subjected to tensile load. The examined samples are printed in flat orientation with 0◦, 45◦ and 90◦ raster angles. During the experiments the deformation of the specimens is continuously scanned with the 3D Aramis measuring system utilizing the digital imaging correlation technique,...
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The elasto-plastic numerical study of crack initiation in notched PMMA specimens under uniaxial loading conditions – Tension and torsion
PublikacjaThis paper presents the results of FEM numerical calculations aimed at describing the plastic strain and stress fields under critical loading conditions: tensile force or torsional moment. The calculations were carried out with reference to the results of experimental tensile and torsional tests of flat PMMA specimens weakened with V-notches of different root radii: 0.5, 2 and 10 mm. The procedure for conducting nonlinear numerical...
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New Algorithms for Adaptive Notch Smoothing
PublikacjaThe problem of extraction/elimination of a nonstationary complex sinusoidal signal buried in noise is considered. This problem is usually solved using adaptive notch filtering (ANF)algorithms. It is shown that accuracy of signal estimation can be increased if the results obtained from ANF are further processed using a cascade of appropriately designed filters. The resulting adaptive notch smoothing (ANS) algorithms can be employed...
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On the well posedness of static boundary value problem within the linear dilatational strain gradient elasticity
PublikacjaIn this paper, it is proven an existence and uniqueness theorem for weak solutions of the equilibrium problem for linear isotropic dilatational strain gradient elasticity. Considered elastic bodies have as deformation energy the classical one due to Lamé but augmented with an additive term that depends on the norm of the gradient of dilatation: only one extra second gradient elastic coefficient is introduced. The studied class...
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Truncation of Huia versabilis Bowman-Birk inhibitor increases its selectivity, matriptase-1 inhibitory activity and proteolytic stability
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CONTROL OF THE WAVES IN A TOWING TANK WITH THE USE OF A BLACK-BOX MODEL
PublikacjaThe paper describes an adaptive control system of the waves, implemented in the Ship Design and Research Centre, CTO S.A. The purpose of generating the waves in the towing tank is the modelling of the environmental conditions during hydrodynamic model tests. The tests are performed on scale models of towed or free running ships, anchored structures like oil rigs or bottommounted structures, e.g. wind turbines. In the towing tank...
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Freehand drawing versus digital design tools in architectural teaching
PublikacjaThe oldest drawings resembling modern architectural designs date from the 22nd Century BC. Throughout history, the first drawings have evolved into the basic tool of the architect’s work. The exchange of information between the architect and the contractor began to take place through a drawing system, allowing to describe three-dimensional space using flat representations. With time, architectural drawings also began to resemble...
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Analysis of an Attenuator Artifact in an Experimental Attack by Gunn–Allison–Abbott Against the Kirchhoff-Law–Johnson-Noise (KLJN) Secure Key Exchange System
PublikacjaA recent paper by Gunn–Allison–Abbott (GAA) [L. J. Gunn et al., Scientific Reports 4 (2014) 6461] argued that the Kirchhoff-law–Johnson-noise (KLJN) secure key exchange system could experience a severe information leak. Here we refute their results and demonstrate that GAA’s arguments ensue from a serious design flaw in their system. Specifically, an attenuator broke the single Kirchhoff-loop into two coupled loops, which is an...
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Optimal shape design of multi-element trawl-doors using local surrogate models
PublikacjaTrawl-doors have a large influence on the fuel consumption of fishing vessels. Design and optimiza-tion of trawl-doors using computational models are a key factor in minimizing the fuel consump-tion. This paper presents an optimization algorithm for the shape design of trawl-door shapes using computational fluid dynamic (CFD) models. Accurate CFD models are computationally expensive. Therefore, the direct use of traditional optimization...
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Computer-aided evaluation of the railway track geometry on the basis of satellite measurements
PublikacjaIn recent years, all over the world there has been a period of intensive development of GNSS (Global Navigation Satellite Systems) measurement techniques and their extension for the purpose of their applications in the field of surveying and navigation. Moreover, in many countries a rising trend in the development of rail transportation systems has been noticed. In this paper, a method of railway track geometry assessment based...
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Thermal and hydraulic phenomena in boundary layer of minijets impingement on curved surfaces
PublikacjaPresented work considers flow and thermal phenomena occurring during the single minijet impingement on curved surfaces, heated with a constant heat flux, as well as the array of minijets. Numerical analyses, based on the mass, momentum and energy conservation laws, were conducted, regarding single phase and two-phase simulations. Focus was placed on the proper model construction, in which turbulence and boundary layer modeling...
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Equivalence scales for continuous distributions of expenditure
PublikacjaResearch background: In the actual sizable populations of households, the standard microeconomic concept of equivalence scales is intractable since its necessary condition of equality of household welfare levels is unlikely to be fulfilled. Purpose of the article: This paper aims to develop a concept of an equivalence scale, which can be suitable for continuous distributions of expenditures in the population. Methods: Using household...
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PV installations and the safety of residential buildings
PublikacjaThe dynamic development of the photovoltaic industry entails threats that have a direct impact on the safety of residential buildings. Appropriate design of a PV installation can be a challenge due to the multifaceted nature of this issue. The designer should take into account issues related to the selection of electrical parameters of the installation, adapting lightning and surge protection in accordance...
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Metoda f-chart w zastosowaniu do projektu instalacji solarnej w budownictwie jednorodzinnym
PublikacjaW artykule przedstawiono algorytm obliczeń cieplnych związanych z konwersją promieniowania cieplnego oraz analizę efektów pracy instalacji solarnej przy użyciu metody korelacyjnej f-chart. Zaprezentowany algorytm obliczeń cieplnych oraz omówiona w artykule podstawowa odmiana metody f-chart zostały poparte przykładem obliczeniowym dla instalacji solarnej, która wykorzystywana jest do wspomagania układu przygotowania c.w. dla potrzeb...
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STUDY OF ARRAY OF MEMS INERTIAL MEASUREMENT UNITS UNDER QUASI-STATIONARY AND DYNAMIC CONDITIONS
PublikacjaA measurement system includes all components in a chain of hardware and software that leads from a measured variable to processed data. In that context, the type and quality of the sensors or measuring devices are critical to any measurement system. MEMS/IMU sensors lag behind leading technologies in this respect, but the MEMS/IMU performance rapidly changes while is relatively inexpensive. For this reason, the paper proposes...
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Amyloid fibril formation in the presence of water structure-affecting solutes
PublikacjaThe impact of the differently hydrated non-electrolytes (protein structure destabilizers) on the fibrillation of hen egg white lysozyme (HEWL) was investigated. Two isomeric urea derivatives i.e. butylurea (BU) and N,N,N′,N′-tetramethylurea (TMU) were chosen as a tested compounds. The obtained results show that butylurea exerts greater impact on HEWL and its fibrillation than tetramethylurea. Both substances decrease the time of...
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Microstructure and Properties of Electroless Ni-P/Si3N4 Nanocomposite Coatings Deposited on the AW-7075 Aluminum Alloy
PublikacjaThe article presents the results of mechanical and tribological tests of Ni-P/Si3N4 nanocomposite coatings deposited on the AW-7075 aluminum alloy using the chemical reduction method. The influence of the chemical composition on the Vickers microhardness determined by the DSI method was examined. The nanocomposite layers were made of Si3N4 silicon nitride in a polydisperse powder with a particle size ranging from 20 to 25 nm. The...
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Standard deviation as the optimization criterion in the OptD method and its influence on the generated DTM
PublikacjaReduction of the measurement dataset is one of the current issues related to constantly developing technologies that provide large datasets, eg. laser scanning. It could seems that presence and evolution of processors computer, increase of hard drive capacity etc. is the solution for development of such large datasets. And in fact it is, however, the “lighter” datasets are easier to work with. Additionally, reduced datasets can...
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Properties of ordered titanium templates covered with Au thin films for SERS applications
PublikacjatCurrently, roughened metal nanostructures are widely studied as highly sensitive Raman scattering sub-strates that show application potential in biochemistry, food safety or medical diagnostic. In this workthe structural properties and the enhancement effect due to surface enhanced Raman scattering (SERS) ofhighly ordered nano-patterned titanium templates covered with thin (5–20 nm) gold films are reported.The templates are formed...
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WYBRANE WŁAŚCIWOŚCI FIZYCZNO-CHEMICZNE MIKROSFER I MOŻLIWOŚĆ ICH WYKORZYSTANIA W KOMPOZYTACH CEMENTOWYCH : The selected physico-chemical properties of microspheres and possibility of their use in cement composites
PublikacjaMicrospheres are formed during the mineral transformation stage in coal combustion. Their content in fly ashes from the combustion of different types of coals varies over a rather wide range from 0.01 to 4.8 wt.%. The microspheres have three main elements, silicon, aluminum and iron, the oxides of which account for about 89.0 wt.% of the material. Mineralogical analysis using XRD shows that microspheres mainly contain mullite and...
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Heat transfer intensification by jet impingement – numerical analysis using RANS approach
PublikacjaJet impingement is a method of the heat transfer enhancement applied in the engineering systems. The idea is to generate fast-flow fluid jet which impinge on the heated (or cooled) surface, causing significantly higher heat transfer rate. Although some flat surface jet impingement cases are described in the literature, the validated data is still limited. The reason is coming from the fact, that these flows are hydrodynamically...
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Towards spectroscopic monitoring of photoelectrodes: In-situ Raman photoelectrochemistry of a TiO2/prussian blue photoanode
PublikacjaHere, novel in-situ Raman photoelectrochemical measurements are performed. The obtained results have proved that it is possible to track the progress of a photoelectrochemical reaction that takes place on a semiconducting electrode using the spectroscopic method. As an exemplary system, the Ti/TiO2/Prussian blue electrode is investigated. Since TiO2 is an n-type semiconductor, it cannot act as an efficient anode in dark conditions....
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Free-standing TiO2 nanotubes decorated with spherical nickel nanoparticles as a cost-efficient electrocatalyst for oxygen evolution reaction
PublikacjaHere, we report significant activity towards the oxygen evolution reaction (OER) of spherical nickel nanoparticles (NPs) electrodeposited onto free-standing TiO2 nanotubes (TNT) via cyclic voltammetry. It has been shown that simple manipulation of processing parameters, including scan rate and number of cycles, allows for formation of the NPs in various diameters and amounts. The polarization data with respect to transmission electron...
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Influence of meniscus shape in the cross sectional plane on the knee contact mechanics
PublikacjaWe present a three dimensional finite element analysis of stress distribution and menisci deformation in the human knee joint. The study is based on the Open Knee model with the geometry of the lateral meniscus which shows some degenerative disorders. The nonlinear analysis of the knee joint under compressive axial load is performed. We present results for intact knee, knee with partial and complete radial posterior meniscus root...
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N-doped mesoporous carbon nanosheets obtained by pyrolysis of a chitosan–melamine mixture for the oxygen reduction reaction in alkaline media.
PublikacjaBy simple thermal decomposition of low-cost precursors (chitosan, melamine) in an inert atmosphere, nitrogen-doped porous carbonaceous materials were prepared. The samples pyrolyzed at 700 C are composed of mainly mesoporous nitrogen-doped carbon nanosheets and partially graphitized carbon. The nanosheets contain a disordered area due to the strain imposed by the presence of nitrogen and/or oxygen groups in their structure. Some...
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Windowing of the Discrete Green's Function for Accurate FDTD Computations
PublikacjaThe paper presents systematic evaluation of the applicability of parametric and nonparametric window functions for truncation of the discrete Green's function (DGF). This function is directly derived from the FDTD update equations, thus the FDTD method and its integral discrete formulation can be perfectly coupled using DGF. Unfortunately, the DGF computations require processor time, hence DGF has to be truncated with appropriate...