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Search results for: TRANSVERSE SURFACE WAVE
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Wear Resistance Enhancement of Al6061 Alloy Surface Layer by Laser Dispersed Carbide Powders
PublicationIn this paper, results of the experimental study on improving wear resistance in sliding friction of Al-based alloy are presented. The technique used involves the formation of a metal matrix composite (MMC) in the alloy surface layer by laser dispersion of carbide powders such as WC, TiC and SiC. For WC and TiC MMC surface coatings fabricated under conditions typical for most of the technologically relevant solid-state lasers (wavelength...
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Metamaterial-Based Series-Fed Antenna with High Gain and Wideband Performance for Millimeter Wave Spectrum Applications
PublicationThis paper presents a high-gain, wideband series-fed antenna designed for 5G millimeter-wave (MMW) applications. The structure employs a substrate-integrated waveguide (SIW)-based power splitter and metamaterials (MMs). The power divider functions effectively at 27.5 GHz, exhibiting an impedance bandwidth from 26.9–28.6 GHz. The series-fed dipole is assembled on the SIW-based power splitter, incorporating four dipoles with varying...
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EXPERIMENTAL STUDY OF SURFACE ROUGHNESS EFFECT ONTHE RHEOLOGICAL BEHAVIOR OF MR FLUID
PublicationPaper presents the results of shear stress measurements of a commercial magnetorheological fluid using a plate-plate type geometry with a modified working surface. The purpose of the study was to determine the effect of changing the roughness of the measuring plate on the obtained shear stress results. Controlled shear rate tests and Magneto Sweep measurements were carried out for three MR fluid layer heights. The tests were...
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The influence of humic substances in treated sewage on the quality of surface waters
PublicationAt present the evaluation of WWTP effectiveness is based upon organic matter and nutrients removal. Recently it was found out that sewage treatment leads to formation of resistant to biochemical degradation organic compounds, similar to humic acids. The humic acids formed during sewage treatment process play diversified functions when discharged to surface waters - for instance they can act as carriers of hydrophobic organic pollutants...
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Blade Section Prpfile Array Lifting Surface Design Method for Marine Screw Propeller Blade
PublicationThe lifting surface model is widely used in screw propeller design and analysis applications. It serves as a reliable tool for determination of the propeller blade mean line and pitch distribution. The main idea of this application was to determine the blade shape that would satisfy the kinematic boundary condition on its surface with the prescribed bound circulation distribution over it. In this paper a simplified lifting surface...
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Overflowing tests at the Polish DredgDikes research dike – stability of the dike surface against erosion
PublicationIn the project DredgDikes the different research dike embankments were tested with respect to overflowing water induced erosion. Therefore, flumes were installed on the land side embankments in which the effect of overflowing water on the vegetated surface was investigated. On the Polish DredgDikes research dike near Gdansk, Poland, two parallel flumes were installed and the surface of the dike made of different mixtures of...
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Wireless Local Area Network Technologies as Communication Solutions for Unmanned Surface Vehicles
PublicationAs the number of research activities and practical deployments of unmanned vehicles has shown a rapid growth, topics related to their communication with operator and external infrastructure became of high importance. As a result a trend of employing IP communication for this purpose is emerging and can be expected to bring significant advantages. However, its employment can be expected to be most effective using broadband communication...
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Spikes removal in surface measurement
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Phonons at the Fe(110) Surface
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Smoothing of wood surface by burnishing
PublicationW artykule zaprezentowano rozwój bezwiórowych metod obróbki wykańczającej drewna. Przedstawiono wpływ nagniatania ślizgowego na chropowatość powierzchni drewna. Badania przeprowadzono na próbkach wykonanych z drzewa sosnowego toczonych i nagniatanych ślizgowo. Nagniatanie ślizgowe przeprowadzono z wykorzystaniem nagniataka elastycznego o elemencie ślizgowym wykonanym z Karbonado. Wyniki odniesiono do głównych parametrów nagniatania...
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Surface properties of barley straw
PublicationWłaściwości powierzchniowe słomy jęczmiennej (Hordeum vulgare) odgrywają kluczową rolę w zastosowaniach przemysłowych, takich jak sorpcja rozlewów olejowych oraz oczyszczenie gleby. Zbadano niejednorodność chemiczną oraz morfologiczną liści i łodyg słomy jęczmiennej poprzez pomiar kątów zwilżania wodą oraz olejem oraz z zastosowaniem techniki FTIR, SEM oraz AFM.
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Dynamics of surface floating objects
PublicationPrezentowana praca stanowi wstępne rozeznanie w dziedzinie badań dynamiki konstrukcji pływających z zastosowaniem teorii procesu dyfuzji. W pracy rozpatrywane są modele fizyczne jednostek wielokadłubowych oraz modele matematyczne. Spośród modeli jednostek wielokadłubowych wyróżnia się modele deterministyczne oraz modele stochastyczne.
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The surface photoconductivity in molecular layers
PublicationW pracy przedstawiono rezultaty analizy fotoprądów powierzchniowych w cienkich warstwach tetracenu i pentacenu. W szczególności badano wpływ obecności defektów strukturalnych w warstwach na charakterystyki fotoprądów i transport nośników ładunku.
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Influence of the Square Wave Voltage on Dynamical Properties of a Flat Voltammetric Electrode in the Time Domain by the Electrochemical Reversible Reaction
PublicationIn this article there is a presentation of the analysis of the polarizing voltage shape influencing dynamic properties of voltammetric electrodes when on their surface reversible reaction takes place in the time domain. The electrode polarization with linearly increasing voltage and with a square component, was analyzed. The analysis that were conducted showed that the voltammetric electrode behaves like a first order transducer....
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Tyre/road noise reduction by a poroelastic road surface
PublicationLow noise road surfaces of existing types may in favourable cases and in new conditions provide up to 7 dB of noise reduction. For higher noise reductions, innovative solutions must be sought. Poroelastic road surfaces (PERS) may be such a solution, which currently is studied in the EU project PERSUADE. This paper presents results of trials with a PERS version prefabricated by one of the project partners. Tests were made in a laboratory...
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Cascading transitions toward unconventional charge density wave states in the quasi-two-dimensional monophosphate tungsten bronze P4W16O56
PublicationSingle crystals of the m = 8 member of the low-dimensional monophosphate tungsten bronzes (PO2)4(WO3)2m family were grown by chemical vapour transport technique and the high crystalline quality obtained allowed a reinvestigation of the physical and structural properties. Resistivity measurements revealed three anomalies at TC1 = 258 K, TC2 = 245 K and TC3 = 140 K, never observed until now. Parallel X-ray diffraction investigations...
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Scattering of the plane wave from a periodically perforated dielectric slab
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Longitudinal wave propagation. Part I—Comparison of rod theories
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Longitudinal wave propagation. Part II—Analysis of crack influence
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Radio wave propagation conditions for terrestrial radiocommunications in the EHF band
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WAVE AND CURRENT MODELLING OVER THE BALTIC SEA AND THE GDAŃSK BAY
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Numerical modelling of conical wave formation in multimode optical fibers
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Numerical analysis of the finite amplitude plane wave propagation problem
PublicationRozważano zagadnienie propagacji fali płaskiej o skończonej amplitudzie w środowisku wodnym. Przedstawiono model matematyczny i przykładowe wyniki obliczeń numerycznych. Model matematyczny zbudowano w oparciu o równanie akustyki nieliniowej. Do rozwiązania zagadnienia zastosowano metodę różnic skończonych. Badano wpływ wartości parametrów numerycznych na dokładność obliczeń oraz analizowano wpływ wartości parametrów fizycznych...
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Spectral Wave Energy Dissipation due to Under-Ice Turbulence
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Characteristics of the s–Wave Symmetry Superconducting State in the BaGe3 Compound
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Diagnostics of bolted lap joint using guided wave propagation
PublicationThe paper presents numerical and experimental analyses of elastic waves propagation in a bolted lap joint. In experimental investigations condition assessment of the joint was performed with the use of symmetric waves excited by a piezoactuator. Numerical calculations were conducted in commercial finite element method software Abaqus. The influence of number of bolts and the value of the initial stress on recorded signals was examined....
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Oblique Plane Wave Scattering by an Array of Dielectric and Metamaterial Cylinders.
PublicationBadanie wpływu ujemnej przenikalności elektrycznej i magnetycznej na parametry rozproszenia fali elektromagnetycznej dla cylindrów wykonanych z dielektryka i metamateriału. Wykorzystanie zmodyfikowanej procedury iteracyjnej i metody dopasowania rodzajów do analizy ukośnego padania fali elektromagnetycznej na zbiór równoległych cylindrów.
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Square-wave propagation along coupled coplanar transmission line.
PublicationW pracy przedstawiono wyniki modelowania propagacji fali prostokątnej w układzie sprzężonych linii koplanarnych z uziemionym centralnym paskiem. Przeanalizowano napięcia przesłuchów na bliskim i dalekim końcu linii sprzężonych wykazując poprawę zgodności wyników modelowania i eksperymentu przy uwzględnieniu propagacji wielomodowej.
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Wave-induced pore pressure oscillations in sandy seabed sediments
PublicationPracę poświęcono zagadnieniu wywoływania cyklicznych oscylacji ciśnieniacieczy porowej w piaszczystym gruncie dna morskiego w wyniku oddziaływania progresywnego falowania powierzchniowego. Dokonano szerokiego przeglądu i analizy istniejących teorii ciśnień cieczy porowej z punktu widzenia skom- plikowania opisu matematycznego zachowania się ośrodka wodno-gruntowego. Wyprowadzono dwuwymiarowe rozwiązanie analityczne i...
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Nonlinear evolution of components of electromagnetic field of helicoidal wave in plasma
PublicationWyprowadzilismy model równań opisujących oddziaływanie pomiedzy kołowo spolaryzowanymi paczkami fal helikoidalnych w dwuwymiarowej plazmie. Dla quasi-jednowymiarowego przypadku otrzymaliśmy warunek nieliniowego rezonansu dla oddziaływania N-fal. Nowym ''osiągnięciem'' badań w kontekscie teorii solitonów, jest znalezienie rozwiązań dla przypadku asynchronizmu fal, które wydaje się być podstawowym dla paczek falowych nachylonych...
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Longitudinal wave propagation. Part II, Analysis of crack influence
PublicationW pracy analizowano wpływ pęknięć zmęczeniowych na propagacje fali wzdłużnej w prętach. Opracowano nowe typy element ów spektralnych oparte na teorii elementarnej, Love'a, Mindlina i trójpostaciowej.
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Longitudinal wave propagation. Part I - Comparison of rod theories
PublicationW pracy przedstawiono modele spektralnych elementów skończonych do analizy propagacji fali wzdłuznej w pretach. Opracowano modele wykorzystujace teorię elementarną, teorie Love'a, teorie Mindlina oraz teorię trójpostaciową.
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Radiation phenomena from pseudochiral cylinders at plane wave incidence
PublicationPrzedstawiono wpływ materiałów pseudochiralnych na charakterystyki rozproszenia fali elektromagnetycznej od obiektów cylindrycznych. W celu zbadania zjawisk rozproszenia zastosowano kombinacje iteracyjnej procedury rozproszenia i metodę dopasowania rodzajów. Wpływ zastosowania materiałów pseudochiralych w konfiguracjach obiektów cylindrycznych zaprezentowano na charakterystykach pola rozproszonego w strefie dalekiej oraz na charakterystykach...
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Characterization of wave structures containing sets of bow-tie resonators
PublicationArtykuł opisuje metodę analizy rozpraszania fali elektromagnetycznej układzie rezonatorów motylkowych w strukturach otwartych i zamkniętych. W artykule zaprezentowano przykłady aplikacji układów mikrofalowych zawierające opisywane elementy.
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Damage detection in elements of strutures by the elastic wave propagation method.
PublicationW pracy przedstawiono wyniki badań dotyczace wykorzystania fal sprężystych do detekcji uszkodzeń i jedno i dwu wymiarowych elementach konstrukcyjnych.
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Research on wave structures containing sets of metallized cylindrical objects
PublicationCel pracy obejmował opracowanie modelu matematycznego opartego na bezpośredniej interpretacji fizycznej rozpraszania fali elektromagnetycznej w zamkniętych i otwartych systemach zawierających różne konfiguracje złożonych obiektów cylindrycznych. Kolejnym celem było zastosowanie otrzymanego modelu do badania problemów otwartych i zamkniętych, oraz zaproponowanie przykładów ich aplikacji. Tezą pracy było stwierdzenie, że istnieje...
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Domain Reduction in Hybrid Technique for Electromagnetic Wave Scattering Problems
PublicationThis paper proposes a combination of the field matching technique, finite element method and generalized impedance matrix, the main idea of which is to reduce the computational domain by surrounding a scatterer with the smallest convex shape and applying the field matching technique. This approach can be applied for arbitrary shaped scatterers and types of materials and allows for the reduction of the computational domain. In order...
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Vehicle Detection and Speed Estimation Using Millimetre Wave Radar
PublicationThe dataset titled Data from 76- to 81-GHz mmWave Sensor located at S7 road contains data recorded employing an IWR1642 mmWave sensor from Texas Instruments. The data comes from two sessions lasting 24h each. The dataset provides the possibility to perform analyses related to car traffic intensity on one of the carriageways of the motorway heading to the Gdańsk metropolitan area. Based on the gathered data, it is possible to calculate...
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Multi-objective weather routing of sailboats considering wave resistance
PublicationThe article presents a method to determine the route of a sailing vessel with the aid of deterministic algorithms. The method assumes that the area in which the route is to be determined is limited and the basic input data comprise the wind vector and the speed characteristic of the vessel. Compared to previous works of the authors, the present article additionally takes into account the effect of sea waves with the resultant resistance...
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FEM approach to estimate the behaviour of biocomposite metal-surface coating system
PublicationA three dimensional (3D) model of biocomposite metal-surface coating system, which is influenced byknown external forces, is proposed. This model consists of the metallic substrate (Ti6Al4V) and thehydroxyapatite (HA) coating. Using FEM (finite element method), strain-stress maps of model weregenerated for investigating relations between the extreme stress of HA coating and the magnitude ofexternal force and the thickness of the...
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INFORMATION ABOUT DYNAMICS OF THE SEA SURFACE AS A MEANS TO IMPROVE SAFETY OF THE UNMANNED VESSEL AT SEA
PublicationOne of the fundamental states of the sea surface is its heave. Despite of years of the intense scientific inquiry, no clear understanding of the influence of this aspect on the dynamics of the sea environment has emerged. The separation of two nearby fluid elements which one may observed for example as a free floating of small objects on the sea surface (rescuers on the rough sea or small research vessels) is caused by the interaction...
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Measurement system for nonlinear surface spectroscopy by atomic force microscopy for corrosion processes monitoring
PublicationIn addition to traditional imaging the surface, atomic force microscopy (AFM) enables wide variety of additional measurements. One of them is higher harmonic imaging. In tapping mode the nonlinear contact between tip and specimen results in higher frequency vibrations. More information available from the higher harmonics analysis proves to be helpful for more detailed imaging. Such visualization is especially useful for heterogeneous...
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The use of Response Surface Methodology for reliability estimation of aluminum silo subjected to wind load
PublicationAn axisymmetric aluminum silo model with a single, standardized geometric imperfection of its lateral surface is considered. The silo is wind – loaded only. The paper is focused on the critical, or limit value of wind pressure, both producing a loss of stability of the silo. This value is affected by vertical coordinate (position) of the imperfection and the angular relation between the imperfection and the wind direction. Reliability...
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Decomposition of halogenated nucleobases by surface plasmon resonance excitation of gold nanoparticles
PublicationHalogenated uracil derivatives are of great interest in modern cancer therapy, either as chemotherapeutics or radiosensitisers depending on their halogen atom. This work applies UV-Vis spectroscopy to study the radiation damage of uracil, 5-bromouracil and 5- uorouracil dissolved in water in the presence of gold nanoparticles upon irradiation with an Nd:YAG ns-pulsed laser operating at 532nm at dierent uences. Gold nanoparticles...
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Analysis of the Ways to Identify Rail Running Surface Defects by Means of Vibration Signals
PublicationTh e article discusses a preliminary concept of a method enabling the identifi cation of chosen rail running surface defects, such as squats, spalling, and running surface defects, by analysing the parameters of vibration signals. It features a description of the methodology of the conducted tests, the scope thereof, and the selection of the measurement points with specifi c defect types. Th e article covers selected results of...
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Temperature influence on tyre/road noise on poroelastic road surface based on laboratory measurements
PublicationThe temperature effect on measured tyre/road noise is very important phenomena as it may lead to significant errors in measurement results due to substantial influence of this parameter on the obtained values. It depends mainly on the particular tyre-road combination. It is different for dense and porous as well as for bituminous and cement concrete pavements. It differs also depending on tested tyre. The correction procedure for...
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Research into the Movements of Surface Water Masses in the Basins Adjacent to the Port
PublicationThis paper presents the results of the practical and simulation research into determining the routes of movement of small objects moving together with surface water masses in basins adjacent to the port. The results of this research were referenced against the modelling of routes of small objects in port channel basins. The results of practical research concerning the movement of small objects in basins adjacent to the port were...
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Correlation between Fractal Dimension and Areal Surface Parameters for Fracture Analysis after Bending-Torsion Fatigue
PublicationThis paper investigates the fracture surface topography of two steel and aluminum alloys subject to bending-torsion fatigue loadings, as well as their susceptibility to fatigue performance and failure mechanisms. Using fracture surface topography data analysis, elements with different geometries were elaborated. A correlation between the fractal dimension, other selected parameters of surface topography such as areal Sx, and...
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Heterogeneous oxidation of highly boron-doped diamond electrodes and its influence on the surface distribution of electrochemical activity
PublicationThe electrochemical active surface area (EASA) of polycrystalline boron-doped diamond (BDD) electrodes is heterogeneous and can be affected by numerous factors. There is a strong need for proper consideration of BDD heterogeneity in order to improve this material's range of application in electrochemistry. Localized changes in surface termination due to the influence of oxidation agent result in increased surface resistance. The...
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Surface irregularities as a complex signal of tool representation together with uneven displacement in respect to the workpiece
PublicationIn a dynamic machining process, distortion in surface irregularity is a very complex phenomenon. Surface irregularities form a periodic representation of the tool profile with various kinds of disturbance in a broad range of changes in the height and length of the profile. To discern these irregularity disturbances, interactions of the tool in the form of changes perpendicular and parallel relative to the workpiece were analyzed...