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Wyniki wyszukiwania dla: METROPOLITALNE SLOW-PRZEDMIEŚCIE
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Effect of shallow traps on admittance spectra of the system carrying SCLC and on values of charge carrier mobility extracted from susceptance
PublikacjaThe work concerns small-signal spectra of space-charge-limited current below threshold frequency (ft) of shallow traps. It is shown that below ft the small-signal concentration of trapped charge carriers is proportional to and in phase with small-signal concentration of free charge carriers, so there is no room for “slow shallow traps”. Conductance can be reduced by the traps, however no change in the range of real capacitance...
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Nonlinear Interaction of Magnetoacoustic Modes in a Quasi-Isentropic Plasma Flow
PublikacjaThe nonlinear interaction of magnetoacoustic waves in a plasma is analytically studied. A plasma is an open system. It is affected by the straight constant equilibrium magnetic flux density forming constant angle with the wave vector which varies from 0 till . The nonlinear instantaneous equation which describes excitation of secondary wave modes in the field of intense magnetoacoustic perturbations is derived by use of projecting....
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Nonlinear Excitation of the Non-Wave Perturbations by the Magnetoacoustic Waves in the Non-Isentropic Plasma
PublikacjaNonlinear excitation of slow modes by the planar magnetosonic perturbations in a plasma is discussed. Plasma is an open system due to radiation and external heating. This may stipulate enhancement of wave perturbations and hence the acoustical activity of plasma. Plasma is assumed to be a homogeneous ideal gas with infinite electrical conductivity. The straight magnetic field is orthogonal to the velocity of fluid’s...
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Analysis and Risk Evaluation on the Case of Alteration, Revitalization and Conversion of a Historic Building in Gdańsk
PublikacjaEach investment plan, including the one concerning a building, is exposed to the consequences of various types of threats taking place. Therefore, in the case of some large-scale, atypical and complicated building ventures, some actions included in the procedure of risk management should be taken. This will allow for the risk to be eliminated or limited. While preparing a building venture, an investor does not possess full information...
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Interaction of Acoustic and Thermal Modes in the Vibrationally Relaxing Gases. Acoustic Cooling
PublikacjaThe dynamic equation which governs an excess temperature associated with the thermal mode in vibrationally relaxing gas is derived. The nonlinear transfer of acoustic energy to the energy of the thermal mode in a relaxing gas causes slow variation of temperature with time. The nal dynamic equation is instantaneous. All types of sound, including aperiodic, may be considered as an acoustic source of corresponding heating or cooling....
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Interplay of hydrogen bonding and aryl-perfluoroaryl interactions in construction of supramolecular aggregates
PublikacjaThe stacking between aryl and perfluoroaryl units is an important class of the aromatic – aromatic interactions that has attracted rapidly growing interest in recent years. Continuing interest of our group in this subject it had been prepared three new complexes of pentafluorobenzoic acid with benzyl alcohol, 4-methylbenzyl alcohol and 4-tert-butylbenzyl alcohol and in the next step investigated their self-assembly modes by...
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Properties of surface layers of duplex stainless steel after burnishing processes
PublikacjaStress corrosion cracking resistance of cold worked layers of 25 Cr duplex stainless steel grade UR52N+ has been investigated. The surface layers were performed through burnishing treatment. The residual stresses at surface layers were determined using grazing angle incidence X-ray diffraction method (g-sin2 Ψ). Corrosion tests were performed with the use of Slow Strain Rate Test technique in boiling 35% MgCl2 solution. It has...
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On description of periodic magnetosonic perturbations in a quasi-isentropic plasma with mechanical and thermal losses and electrical resistivity
PublikacjaMagnetosonic periodic perturbations in a uniform and infinite plasma model are considered. Damping due to compressional viscosity, electrical resistivity, and thermal conduction are taken into account, as well as some heating–cooling function, which may destroy the isentropicity of wave perturbations. The wave vector forms arbitrary angle h with the equilibrium straight magnetic field, and all perturbations are functions...
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Control system for contactless electrical energy transfer with varying air gap
PublikacjaInductive power transfer (IPT) is a system by which electrical energy may be transmitted without electrical connection through a large air gap between coils. Systems usually considered in the literature are the ones with a constant air gap. The paper describes the analysis of IPT, which allows for supplying an electrical load in the conditions of slow, in relation to the dynamics of power supply, changes in the dimensions of the...
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Fractional Order Dynamic Positioning Controller
PublikacjaImproving the performance of Dynamic Positioning System in such applications as station keeping, position mooring and slow speed references tracking requires improving the position and heading control precision. These goals can be achieved through the improvement of the ship control system. Fractional-order calculus is a very useful tool which extends classical, integer-order calculus and is used in contemporary modeling and control...
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Two Time-Scale Hierarchical Control of Integrated Quantity and Quality in Drinking Water Distribution Systems
PublikacjaThe paper considers a feedback optimising control of drinking water distribution systems (DWDS). Although the optimised pump and valves scheduling and disinfectant injection control attracted considerable attention over last two decades most of the contributions were limited to an open-loop optimisation repetitively performed during the DWDS operation. Also, while a strong interaction between the water quantity and quality exists...
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Miasta na prawach powiatu z rozwiniętym przemysłem jako lokalne ośrodki rozwoju na obszarach peryferyjnych polskich regionów
PublikacjaMost of the growth factors is situated in big cities, especially in metropolitan areas. Questions arise: 1) Whether and what development factors are in the peripheral areas of voivodeships (i.e. outside the functional areas of their capitals)? 2) Can the industry be the driving force of the development of these areas? These questions are related to the discussion on the reindustrialisation of the European Union and the role of...
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Corrosion Study of Ceria Protective Layer Deposited by Spray Pyrolysis on Steel Interconnects
PublikacjaSingle fuel cells and electrolysis cells are assembled into stacks using interconnects in order to increase power and gas production capacity. The most common choice for the interconnect material is stainless steel. It has good electrical and mechanical properties and is also cost effective. One of the problems when using steel is the formation of a thermally grown oxide scale during use which has a lower electrical conductivity...
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A robust design of a numerically demanding compact rat-race coupler
PublikacjaA fast and accurate design procedure of a computationally expensive microwave circuit has been presented step-by-step and experimentally validated on the basis of a compact rat-race coupler (RRC) comprising slow-wave resonant structures (SWRSs). The final compact RRC solution has been obtained by means of a sequential optimization scheme exploiting the implicit space mapping (ISM) algorithm. A well-suited surrogate optimization...
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Fading Analysis in Off-Body Channels in a Straight Metallic Corridor in a Passenger Ferry Environment
PublikacjaThis paper presents a fading analysis for Body Area Networks off-body communications at 2.45 GHz in a passenger ferry environment. The results are based on measurements performed for dynamic scenarios in a straight metallic corridor. Two components, extracted from instantaneous system loss values, have been analysed: small- and large-scales fading, separately for each scenario. Well-known probability distribution functions have...
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Standing Acoustic Waves and Relative Nonlinear Phenomena in a Vibrationally Relaxing Gas-Filled Resonator
PublikacjaStanding acoustic waves in one-dimensional resonator filled with vibrationally relaxing gas, are studied. Two regimes of excitation of molecular vibrational degrees of freedom are considered, equilibrium and nonequilibrium. The acoustic energy enlarges with time in the non-equilibrium regime and decreases otherwise before formation of discontinuity. After that, it decreases due to nonlinear absorption and tends to zero in equilibrium...
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LE STIME ECONOMICHE DELLA CIA E L’IMPREVEDIBILE FINE DELL’URSS
PublikacjaIn this article, we will analyze the debate that took place around the assessments that the CIA gave of the economic situation in the Soviet Union, a clearly decisive key to understanding the overall health of the main political-military opponent of the United States. The article will include the discussions that flared up in the American political establishment starting in 1990, after the fall of the Berlin Wall and the initial...
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Magnetoacoustic Heating of Plasma Caused by Periodic MagnetosoundPerturbations with Discontinuities in a Quasi-Isentropic Magnetic Gas
PublikacjaThe magnetoacoustic heating of plasma by harmonic or periodic saw-tooth perturbations at a trans-ducer is theoretically studied. The planar fast and slow magnetosound waves are considered. The wavevector may form an arbitrary angleθwith the equilibrium straight magnetic field. In view of variableθand plasma-β, the description of magnetosound perturbations and appropriate magnetosound heatingis fairly difficult. The scenario of...
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Sulfate‐reducing bacteria‐assisted hydrogen‐induced stress cracking of 2205 duplex stainless steels
PublikacjaThe paper presents the results of a laboratory investigation of the microbiologically assisted hydrogen‐induced stress cracking (HISC) of 2,205 duplex stainless steel (DSS). The testing of susceptibility toward HISC was performed with two different methods. Precharged in sulfate‐reducing bacteria (SRB), inoculated medium samples were subjected to slow strain‐rate testing in artificial seawater. In situ constant load tests were...
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Propagation of acoustic pulses in some fluids with yield stress
PublikacjaThis study is devoted to the derivation of approximate equations governing acoustic pulses in flows with yieldstress, including some time-dependent flows with a slow dependence on time of yield stress and apparent viscosity. Themodeling of yield stress and apparent viscosity in the vicinity of a zero deformation rate allows us to consider a thixotropicfluid as a Bingham plastic with coefficients that are dependent on time. The...
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Rapid Design Tuning of Miniaturized Rat-Race Couplers Using Regression-Based Equivalent Network Surrogates
PublikacjaA simple technique for fast design tuning of compact rat-race couplers is presented. Our approach involves equivalent circuit representation, corrected by nonlinear functions of frequency with coefficients extracted through nonlinear regression. At the same time, the tuning process connects two levels of coupler representation: EM simulation of the entire circuit and re-optimization of the coupler building blocks (slow-wave cells...
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Conditions for Multiple Acquisition of Echoes from Stationary Targets in Successive Transmissions of Active Sonars
PublikacjaIn echolocation, the highest possible number of contacts with a detected target is clearly decisive on the possibilities of echo processing to optimise the estimation of distinctive characteristics of the observed target. In hydrolocation, the slow propagation of acoustic waves in water reduces the number of contacts of echosounders and sonars with detected targets. The article considers model conditions for acquiring multiple...
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The Influence of Cement Type on Early Properties of Cold In-Place Recycled Mixtures
PublikacjaCold in-place recycling is a commonly used maintenance treatment in rehabilitation of low and medium volume roads in Poland. Typically, two types of binding agents are used—cement and bituminous emulsion (or foamed bitumen).Due to the harsh Polish climate with many freeze/thaw cycles and frequent occurrence of saturated conditions, the used amounts of cement are higher than those commonly used in warmer parts of Europe. While there...
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The potential of urban agriculture in the revitalisation of a metropolis
PublikacjaIn Poland, the topic addressing urban areas of agricultural production and gardening activity is still viewed in two main blocks: 1) a shift of the urbanized zone’s boundaries, causing dispersion of suburban buildings as well as creates conflict zone between the residential area and the production and post-production zones; 2) a socially contentious issue of restructuring the inner-city complexes of former employee allotments....
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Use of a wastewater recovery product (struvite) to enhance subtropical seagrass restoration
PublikacjaSeagrasses are in decline worldwide, and their restoration is relatively expensive and unsuccessful compared to other coastal systems. Fertilization can improve seagrass growth in restoration but can also release nutrients and pollute the surrounding ecosystem. A slow-release fertilizer may reduce excessive nutrient discharge while still providing resources to the seagrass's rhizosphere. In this study, struvite (magnesium ammonium...
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Application of Maximum Lenght Sequence in Silent Sonar
PublikacjaSilent sonars are designed to reduce the distance over which their sounding pulses can be detected by intercept sonars. In order to meet this objective, we can use periodical sounding signals that have low power, a very long duration and wide spectrum. If used in the silent sonar's receiver, matched filtration ensures very good detection of motionless or slow moving targets. However, it is more difficult to detect echo signals...
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Hydrogen direct reduction and reoxidation behaviour of high-grade pellets
PublikacjaHigh grade pellets with basicity index close to 0.5 were directly reduced in pure hydrogen atmosphere. The reduction experiments were performed in the temperature range 800 e1000 C at the pressure of 8 bar. The pellets internal structure was analysed through micro tomography observations in the unreduced and reduced conditions. After reduction, the pellets showed a variation of porosity up to more than 15% with a remarkable change...
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Single-Slope ADC With Embedded Convolution Filter for Global-Shutter CMOS Image Sensors
PublikacjaThis brief presents an analog-to-digital converter (ADC) suitable for acquisition and processing of images in the global-shutter mode at the pixel level. The ADC consists of an analog comparator, a multi-directional shift register for the comparator states, and a 16-bit reversible binary counter with programmable step size. It works in the traditional single-slope mode. The novelty is that during each step of the reference ramp,...
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Optimization of Bread Production Using Neuro-Fuzzy Modelling
PublikacjaAutomation of food production is an actively researched domain. One of the areas, where automation is still not progressing significantly is bread making. The process still relies on expert knowledge regarding how to react to procedure changes depending on environmental conditions, quality of the ingredients, etc. In this paper, we propose an ANFIS-based model for changing the mixer speed during the kneading process. Although the...
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Low cost microwave X-band generator
PublikacjaA low cost microwave X-band generator for educational purposes was designed and built. Its simple construction and user's interface makes it suitable for a student laboratory.The generator is based on a single frequency conversion concept. It uses a digitally tunable PLL chip for intermediate frequency generation and an active frequency multiplier for frequency conversion. The generator covers 9,7 - 11 GHz part of the X frequency...
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Simulating Power Generation from Photovoltaics in the Polish Power System Based on Ground Meteorological Measurements—First Tests Based on Transmission System Operator Data
PublikacjaThe Polish power system is undergoing a slow process of transformation from coal to one that is renewables dominated. Although coal will remain a fundamental fuel in the coming years, the recent upsurge in installed capacity of photovoltaic (PV) systems should draw significant attention. Owning to the fact that the Polish Transmission System Operator recently published the PV hourly generation time series in this article, we aim...
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Hydrogen embrittlement of X2CrNiMoCuN25-6-3 super duplex stainless steel welded joints under cathodic protection
PublikacjaThe effect of cathodic polarization conditions on hydrogen degradation of X2CrNiMoCuN25-6-3 super duplex stainless steel welded joints, obtained using flux cored arc and submerged arc welding methods, was evaluated. Slow strain rate tensile tests of base material and welded specimens, ferrite content measurements, scanning electron microscopy observations, and statistical analysis were performed. It was found that hydrogenation...
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Effective configuration of a double triad planar parallel manipulator for precise positioning of heavy details during their assembling process
PublikacjaIn the paper, dynamics analysis of a parallel manipulator is presented. It is an atypical manipulator, devoted to help in assembling of heavy industrial constructions. Few atypical properties are required: small workspace; slow velocities; high loads. Initially, a short discussion about definition of the parallel manipulators is presented, as well as the sketch of the proposed structure. In parallel, some definitions, assumptions...
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Enviromental factors az the elements determingthe development of floating homes
PublikacjaThe popularity of Floating Homes in Western Europe and North America is noticeable. The interest in thesefacilities in Poland is also constantly growing. The popularity of Floating Homes is due to climate change, risingland prices and population density in city centers. However, environmental factors play a significant role in theirdevelopment. The publication presents the results of research on the impact of environmental factors...
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Magnetoacoustic Heating in Nonisentropic Plasma Caused by Different Kinds of Heating-Cooling Function
PublikacjaThe nonlinear phenomena which associate with magnetoacoustic waves in a plasma are analytically studied. A plasma is an open system with external inflow of energy and radiation losses. A plasma’s flow may be isentropically stable or unstable. The nonlinear phenomena occur differently in dependence on stability or instability of a plasma’s flow. The nonlinear instantaneous equation which describes dynamics of nonwave entropy mode...
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Influence of High Temperature Oxidation on Hydrogen Absorption and Degradation of Zircaloy-2 and Zr 700 Alloys
PublikacjaThe present research was aimed at determining the effects of the oxide layers on hydrogen absorption, microstructure and mechanical properties of the Zircaloy- 2 and Zr 702 alloys. The oxidation was made at 350 °C, 700 °C and 900 °C for 10 to 30 min in laboratory air, followed by hydrogen cathodic charging for 72 h and annealing at 400 °C for 4 h. The slow strain rate tests were carried out on oxidized, charged and annealed specimens. The...
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Productivity effects of trade in natural resources—comparison with mechanisms of technological specialisation
PublikacjaThis paper compares two alternative growth paths, assessing the effects on productivity of specialisation in natural resources (NR) and in technologically advanced products. The empirical analysis exploits product-level export data for 109 developing and 51 developed economies over the period 1996–2018. We document two distinct types of specialisation, based on exports either of natural resources or of technological products, and...
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CLEANING METHODS FOR DUST DEPOSITED ON THE FRONT COVER OF PHOTOVOLTAIC MODULE
PublikacjaPhotovoltaic modules are one of the renewable energy sources with great potential for application in various regions of the world as well as for different terrain. They are, however, sensitive to external factors, affecting the overall amount of energy generated, such as solar irradiance, shading effects and any form of soil build-up on the front glass cover of solar device. The latter issue happens over a course of weeks, months...
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Tyre rolling resistance and its influence on fuel consumption
PublikacjaRolling resistance of tyres is one of the major resistive forces acting on any wheeled vehicle. Unfortunately, it is also one of the forces very difficult to measure. It is estimated that in certain traffic conditions (like for example constant speed driving with slow or moderate speed) so called Rolling Resistance Impact Factor may be as high as 0.3. This means that reduction of rolling resistance by 50% would lead to 15% of energy...
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Wild oscillations in a nonlinear neuron model with resets: (I) Bursting, spike-adding and chaos
PublikacjaIn a series of two papers, we investigate the mechanisms by which complex oscillations are generated in a class of nonlinear dynamical systems with resets modeling the voltage and adaptation of neurons. This first paper presents mathematical analysis showing that the system can support bursts of any period as a function of model parameters, and that these are organized in a period-incrementing structure. In continuous dynamical...
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Graphene field-effect transistor application for flow sensing
PublikacjaMicroflow sensors offer great potential for applications in microfluidics and lab-on-a-chip systems. However, thermal-based sensors, which are commonly used in modern flow sensing technology, are mainly made of materials with positive temperature coefficients (PTC) and suffer from a self-heating effect and slow response time. Therefore, the design of novel devices and careful selection of materials are required to improve the overall...
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INWESTYCJE A ZATRUDNIENIE W POLSCE W PERSPEKTYWIE FINANSOWE 2007-2013
PublikacjaNakłady inwestycyjne przedsiębiorstw traktowane są jako jeden z głównych czynników wzrostu gospodarczego. Ich wielkość i dynamika mogą mieć wpływ na zmiany w poziomie zatrudnienia. Światowy kryzys finansowy przyczynił się do spowolnienia dynamiki wzrostu oraz gwałtownego spadku w 2009 roku PKB w większości gospodarek świata. We wspomnianym okresie w Polsce zaobserwowano spowolnienie gospodarcze, które miało wpływ na decyzje...
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The innovative approach for using pavement as a fire prevention measure in tunnels
PublikacjaThe paper consists of two main parts: first presents study regarding the typically used pavement structures in tunnels and the second part: the first fire trials of the poroelastic SEPOR (Safe, Eco-friendly POroelastic Road Surface) mixture which was designed to be used among other uses in tunnels. In the first part of the paper different pavement materials, such as cement concrete, asphalt concrete, stone mastic asphalt and porous...
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Phytoremediation of heavy metals by white cabbage
PublikacjaPhytoremediation is regarded as the cheapest and environmentally most friendly technology for cleaning up soil. The most widespread and most profitable technique is phytoextraction, used mainly for removing heavy metals and radioactive elements from thesoil. Over 400 plant species have been identified as natural metal hyperaccumulators representing about 0.2 % of all angiosperms. Unfortunately, most of these plants are characterised...
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Design considerations for compact microstrip resonant cells dedicated to efficient branch-line miniaturization
PublikacjaA conventional compact microstrip resonant cell (CMRC)has been thoroughly investigated to enhance its slow-wave properties and subsequently ensure an efficient miniaturization of a microstrip circuit. The geometry of a classic CMRC has been improved in terms of slowwave effect in two progressive steps: (i) a single-element topology has been replaced with a double-element one and (ii) a high-impedance section has been refined by...
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Deterministic rendezvous of asynchronous bounded-memory agents in polygonal terrains
PublikacjaTwo mobile agents, modeled as points starting at differentlocations of an unknown terrain, have to meet. The terrain is a polygon with polygonal holes. We consider two versions of this rendezvous problem: exact RV, when the points representing the agents have to coincide at some time, and epsilon-RV, when these points have to get at distance less than epsilon in the terrain. In any terrain, each agent chooses its trajectory, but...
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Preparation of Hydrogen Electrodes of Solid Oxide Cells by Infiltration: Effects of the Preparation Procedure on the Resulting Microstructure
PublikacjaIn this work, the infiltration technique was used to produce hydrogen electrodes for solid oxide cells. Different infiltration methodologies were tested in order to try to shorten the infiltration cycle time. The porous scaffolds used for infiltration were based on highly porous yttria-stabilized zirconia (YSZ) obtained by etching the reduced nickel from the Ni-YSZ cermet in HNO3 acid. The support had a complex structure which...
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Hydrogen Damage in Superaustenitic 904L Stainless Steels
Publikacjaresults on the influence of hydrogen on corrosion resistance and of hydrogen embrittlement of 904L superaustenitic stainless steel were investigated. The cracking behavior was studied by performing a slow strain rate test in synthetic seawater under varying cathodic polarization conditions. The results showed that the steel’s plasticity varied with the applied cathodic current density. Significant reductions in ductility were found,...
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Multichannel self-optimizing narrowband interference canceller
PublikacjaThe problem of cancellation of a nonstationary sinusoidal interference, acting at the output of an unknown multivariable linear stable plant, is considered. No reference signal is assumed to be available. The proposed feedback controller is a nontrivial extension of the SONIC (self-optimizing narrowband interference canceller) algorithm, developed earlier for single-input, single-output plants. The algorithm consists of two loops:...
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Magnetoacoustic heating in a quasi-isentropic magnetic gas
PublikacjaThe nonlinear heating of a plasma which associates with the transfer of energy of magnetoacoustic waves into that of the entropy mode, is analytically studied. A plasma is uniform and motionless at equilibrium. Perturbations in a plasma are described by a system of ideal magnetohydrodynamic equations. The equilibrium straight magnetic strength and the wave vector form a constant angle which varies from 0 to π/2. There exist four...