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Search results for: CABLE, FINITE ELEMENT MODELING (FEM), PARTIAL DISCHARGE (PD), SOLID DIELECTRIC, VOID
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A constitutive model for concrete based on continuum theory with non-local softening coupled with eXtended Finite Element Method. Computational Modelling of Concrete Structures,
PublicationArtykuł omawia model połączony ciągły-nieciągły do modelowania stref lokalizacji i rys w betonie niezbrojonym. Obliczenia wykonano stosując rozszerzoną metodę elementów skończonych. Wyniki numeryczne porównano z doświadczeniami.
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Dielectric strenght of the ultra - short fuse
PublicationW referacie omówiono współpracę ultraszybkiego bezpiecznika z bezstykowymhybrydowym ogranicznikiem prądów. Przeanalizowano wytrzymałość kanału połukowego bezpiecznika w zależności od długości topika oraz czasu działania tranzystora IGBT. Omówiono warunki i wyniki badań eksperymentalnych.
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Nonlinear Modeling in Time Domain Numerical Analysis of Stringed Instrument Dynamics
PublicationMusical instruments are very various in terms of sound quality with their timbre shaped by materials and geometry. Materials' impact is commonly treated as dominant one by musicians, while it is unclear whether it is true or not. The research proposed in the study focuses on determining influence of both these factors on sound quality based on their impact on harmonic composition. Numerical approach has been chosen to allowed independent...
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New Polymeric Materials for Solid Phase Extraction
PublicationSolid phase extraction (SPE) is a popular sample preparation technique, which can be applied directly in gas–solid phase and liquid–solid phase, or indirectly to solid samples by using, e.g., thermodesorption with subsequent chromatographic analysis. Although SPE can be described as a physical extraction process involving a liquid phase and a solid phase, the increased use of packed sorbent formats seems to have led to a bias toward...
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MAGNETOACOUSTIC HEATING AND STREAMING IN A PLASMA WITH FINITE ELECTRICAL CONDUCTIVITY
PublicationNonlinear effects of planar and quasi-planar magnetosound perturbations are discussed. Plasma is assumed to be an ideal gas with a finite electrical conductivity permeated by a magnetic filed orthogonal to the trajectories of gas particles. the excitation of non-wave modes in the filed of intense magnetoacoustic perturbations, i.e., magnetoaciustic heating and streaming, is discussed. The analysis includes a derivation if instantaneous...
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The effect of preparation route on structure and photocatalytic properties of bimetallic nanoparticles (Au/Pd, and Au/Pt) deposited at TiO2 surface
PublicationNoble metal nanoparticles have often been used to enhance the photocatalytic activity of TiO2 and to extend the absorption wavelength from the ultraviolet to visible region. Bimetallic nanoparticles, composed of two different metal elements, can exhibit peculiar electronic, optical, and catalytic or photocatalytic properties that are absent in the corresponding monometallic nanoparticles. In this work we show the effect kind and...
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Miniaturized solid-phase extraction techniques
PublicationMore than 80% of analysis time is spent on sample collection and sample preparation, so sample preparation is a critical part of the analytical process. Traditionally, liquid-liquid extraction was developed and employed to screen for general unknowns. However, solid-phase extraction (SPE) is becoming highly popular as an alternative, due to its simplicity and economy in terms of time and solvent. This review summarizes the current...
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On Reduced-Cost Design-Oriented Constrained Surrogate Modeling of Antenna Structures
PublicationDesign of contemporary antenna structures heavily relies on full-wave electromagnetic (EM) simulation models. Such models are essential to ensure reliability of evaluating antenna characteristics, yet, they are computationally expensive and therefore unsuitable for handling tasks that require multiple analyses, e.g., parametric optimization. The cost issue can be alleviated by using fast surrogate models. Conventional data-driven...
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Smaller Representation of Finite State Automata
PublicationThis paper is a follow-up to Jan Daciuk's experiments on space-effcient finite state automata representation that can be used directly for traversals in main memory. We investigate several techniques of reducing memory footprint of minimal automata, mainly exploiting the fact that transition labels and transition pointer offset values are not evenly distributed and so are suitable for compression. We achieve a gain of around 20-30%...
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A Novel Approach to Fully Nonlinear Mathematical Modeling of Tectonic Plates
PublicationThe motion of the Earth's layers due to internal pressures is simulated in this research with an efficient mathematical model. The Earth, which revolves around its axis of rotation and is under internal pressure, will change the shape and displacement of the internal layers and tectonic plates. Applied mathematical models are based on a new approach to shell theory involving both two and three-dimensional approaches. It is the...
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Reduced-Cost Microwave Modeling Using Constrained Domains and Dimensionality Reduction
PublicationDevelopment of modern microwave devices largely exploits full-wave electromagnetic (EM) simulations. Yet, simulation-driven design may be problematic due to the incurred CPU expenses. Addressing the high-cost issues stimulated the development of surrogate modeling methods. Among them, data-driven techniques seem to be the most widespread owing to their flexibility and accessibility. Nonetheless, applicability of approximation-based...
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LS-DYNA simulations of the impacts of a 38-ton Heavy Goods Vehicle into a road cable barrier
PublicationNowadays, more and more attention is being paid to safety on roads and motorways. It is due to the continuous development of road and motorway network and a significant increase of the number of vehicles on roads. To meet the expectations of improving road safety in Poland, the Road Innovations Development (RID) research programme was implemented in 2016. The aim of the RID 3A - Road Safety Equipment (RoSE) project is a comprehensive...
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Fundamentals of Data-Driven Surrogate Modeling
PublicationThe primary topic of the book is surrogate modeling and surrogate-based design of high-frequency structures. The purpose of the first two chapters is to provide the reader with an overview of the two most important classes of modeling methods, data-driven (or approx-imation), as well as physics-based ones. These are covered in Chap-ters 1 and 2, respectively. The remaining parts of the book give an exposition of the specific aspects...
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Magnetic properties of Co/Pd multilayered films on porous Al2O3 templates with developed cell substructure
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Spectroscopic and cytotoxic characteristics of (p-cymene)Ru(II) complexes with bidentate coumarins and density functional theory comparison with selected Pd(II) complexes
PublicationThis paper presents the synthesis of two new (p-cymene)-ruthenium(II) complexes with the bidentate coumarin ligands. Both complexes were characterized by FTIR spectroscopy, 1H NMR, 13C NMR, MS, elemental analysis and DFT calculations. The X-ray structure of complex 3a was also solved. The cytotoxic properties of both complexes were examined on human leukemia NALM-6 and HL-60 cells and melanoma WM-115 cells. The complexes possess...
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First evaluation of wastewater discharge influence on marine water contamination in the vicinity of Arctowski Station (Maritime Antarctica)
PublicationIn Antarctica,waste is generatedmainly during scientific research programmes and related logistics. In this study, the impact ofwastewater on the western shore of Admiralty Baywas investigated during austral summer in 2017 and 2019. A range of physicochemical parameters and the presence of selected trace metals, formaldehyde and different groups of surfactants were determined in wastewater coming from Arctowski Station and in nearby coastal...
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Smart Modeling of Maritime Vessels
PublicationCurrently, the market offers many visualization tools available to graphic designers, engineers, managers and academics working on maritime environments. The practice of visualization involves making and manipulating images that convey novel phenomena and ideas. Visual communication, together with virtual reality environments, is an emerging and rapidly evolving discipline. It brings great advantage over written word or voice alone,...
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Smaller representation of finite state automata
PublicationThis paper is a follow-up to Jan Daciuk's experiments on space-efficient finite state automata representation that can be used directly for traversals in main memory (Daciuk, 2000)[4]. We investigate several techniques for reducing memory footprint of minimal automata, mainly exploiting the fact that transition labels and transition pointer offset values are not evenly distributed and so are suitable for compression. We achieve...
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Dependence Modeling
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Novel Complementary Multiple Concentric Split Ring Resonator for Reliable Characterization of Dielectric Substrates with High Sensitivity
PublicationAccurate characterization of dielectric substrates with high sensitivity remains an important challenge in a variety of industrial applications. This paper proposes an innovative strategy to address this challenge by developing and optimizing a unique Complementary Multiple Concentric Split Ring Resonator (CMC-SRR). The major goal is to propose a sensor design with increased sensitivity and reliability for dielectric characterization....
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Guided Wave Propagation in Detection of Partial Circumferential Debonding in Concrete Structures
PublicationThe following article presents results of investigating the damage detection in reinforced concrete beams with artificially introduced debonding between the rod and cover, using a non-destructive method based on elastic waves propagation. The primary aim of the research was to analyze the possible use of guided waves in partial circumferential debonding detection. Guided waves were excited and registered in reinforced concrete...
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Modeling of a Quasi-Resonant DC Link Inverter Dedicated to Common-Mode Voltage and Ground Current Reduction
PublicationIn this paper, the modeling methodology of the AC drive system with a Parallel Quasi-Resonant DC Link Inverter (PQRDCLI) is described. A presented modeling approach is an attractive tool used for the effective evaluation of a common-mode (CM) voltage and grounds current reduction methods. Designed models of inverter, induction machine (IM), and cable are simple, thus the methods for parameter extraction are not complicated. Verification...
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Existence and uniqueness of monotone and bounded solutions for a finite-difference discretization a` la Mickens of the generalized Burgers–Huxley equation.
PublicationDeparting from a generalized Burgers–Huxley partial differential equation, we provide a Mickens-type, nonlinear, finite-difference discretization of this model. The continuous system is a nonlinear regime for which the existence of travelling-wave solutions has been established previously in the literature. We prove that the method proposed also preserves many of the relevant characteristics of these solutions, such as the positivity,...
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Critical evaluation of recent achievements in low power glow discharge generated at atmospheric pressure between a flowing liquid cathode and a metallic anode for element analysis by optical emission spectrometry
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Numerical Analysis of TB32 Crash Tests for 4-cable Guardrail Barrier System Installed on the Horizontal Convex Curves of Road
PublicationHorizontal curves are one of the elements of road infrastructure where statistically a relatively high number of accidents have been reported. In the last ten years in Poland approx. 10% of all road accidents happened on horizontal curves of roads and was responsible for approx. 14% of all fatalities on Polish roads. Thus, this issue is important and requires extensive research and proper road safety treatments. One possible measure...
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TIME SERIES MODELING 2023/2024
e-Learning Coursesprowadzący: assoc. prof. Ján Dvorský, PhD
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Half-Order Modeling of Saturated Synchronous Machine
PublicationNoninteger order systems are used to model diffusion in conductive parts of electrical machines as they lead to more compact and knowledge models but also to improve their precision. In this paper a linear half-order impedance model of a ferromagnetic sheet deduced from the diffusion of magnetic field is briefly introduced. Then, from physical considerations and finite elements simulation, the nonlinear half-order impedance model...
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Oxygen partial pressure and temperature dependence of series resistance of symmetrical porous SrTi0.30Fe0.70O3 electrode on CGO substrate
Open Research DataThis dataset contains values of equivalent circuit element series resistance at different temperatures (800 °C, 700 °C, 600 °C and 500 °C) and oxygen partial pressures (100%, 80%, 50% 30%, 20%, 15%, 10%, 5%, 2.5%, 1%, and 0.3% pO2) of symmetrical SrTi0.30Fe0.70O3 electrode sintered at 800 °C. This values were obtained by fitting each measured impedance...
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Microwave Characterization of Dielectric Sheets in a Plano-Concave Fabry-Perot Open Resonator
PublicationDespite its long history, a double-concave (DC) Fabry-Perot open resonator (FPOR) has recently gained popularity in the characterization of dielectrics in the 20–110 GHz range, mainly due to such novel accomplishments as full automation of the measurement process and the development of even ore accurate and computationally efficient electromagnetic model. However, it has been discovered that such a DC resonator suffers from unwanted...
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MHD darcy-forchheimer nanofluid flow and entropy optimization in an odd-shaped enclosure filled with a (MWCNT-Fe3O4/water) using galerkin finite element analysis
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Multidiscipline Modeling in Materials and Structures
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PUBLIC SOURCES OF FINANCE FOR CULTURE AS AN ELEMENT OF CULTURAL SECURITY IN POLAND
PublicationCulture is an important element of the country, playing an important role both for its security and the economy. It cannot be only seen as a cost-creating sector, but may be a significant factor in economic development. For this to happen, it is necessary to create a system of financing this economic sector. This article’s aim is to analyze the use of funds from public sources in Poland to finance culture-related activities. The...
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Solid Earth
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Rapid EM-driven antenna dimension scaling through inverse modeling
PublicationIn this letter, a computationally feasible technique for dimension scaling of antenna structures is introduced. The proposed methodology is based on inverse surrogate modeling where the geometry parameters of the antenna structure of interest are explicitly related to the operating frequency. The surrogate model is identified based on a few antenna designs optimized for selected reference frequencies. For the sake of computational...
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COMMUNICATIONS IN PARTIAL DIFFERENTIAL EQUATIONS
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Journal of Partial Differential Equations
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Dynamics of Partial Differential Equations
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Partial Differential Equations and Applications
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Surface finite viscoelasticity and surface anti-plane waves
PublicationWe introduce the surface viscoelasticity under finite deformations. The theory is straightforward generalization of the Gurtin–Murdoch model to materials with fading memory. Surface viscoelasticity may reflect some surface related creep/stress relaxation phenomena observed at small scales. Discussed model could also describe thin inelastic coatings or thin interfacial layers. The constitutive equations for surface stresses are...
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On the influence of shell element properties on the response of car model in crash test
PublicationIt goes without saying that numerical simulations play important role in the modern engineering practice. Contemporary CAD environments combined with FEM solvers, along with computer power of modern processors, give the engineer fast and efficient tool. Ultimately, however it is the user alone who is responsible for the correctness of the results. As long as the FEM calculations remain in the sphere of academic exercise, the inevitable...
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Perovskites in Solid Oxide Fuel Cells
PublicationPrzeglądowa publikacja dotycząca wykorzystania ceramicznych materiałów perowskitowych w tlenkowych ogniwach paliwowych.
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Finite Resolution Dynamics
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Macromodeling in Finite Differences
PublicationRozdział opisuje technikę wykorzystania procesu makromodelowania (wykorzystanie makromodelu do opisu równań różnicowych) w analizie różnic skończonych w dziedzinie czasu. Zawarte informacje pozwalają na samodzielne zaimplementowanie metody i pokazują możliwości poprawienia uzyskiwanych wyników.
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Modeling of Electrified Transportation Systems Featuring Multiple Vehicles and Complex Power Supply Layout
PublicationThe paper proposes a novel approach to modeling electrified transportation systems. The proposed solution reflects the mechanical dynamics of vehicles as well as the distribution and losses of electric supply. Moreover, energy conversion losses between the mechanical and electrical subsystems and their bilateral influences are included. Such a complete model makes it possible to replicate, e.g., the impact of voltage drops on vehicle...
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Porous nanopeapod Pd catalyst with excellent stability and efficiency
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Determination of thiocyanate (biomarkers of ETS) and other inorganic ions in human nasal discharge samples using ion chromatography
PublicationEnvironmental tobacco smoke (ETS) is a mixture of air and tobacco smoke containing more than 4000 chemical substances. In view of the health risks of many of these substances, studies are needed to determine biomarkers of exposure to ETS constituents in people who actively or passively are exposed to the toxic compounds. The methodologies for determining most biomarkers from saliva, urine and blood samples are known, but methods...
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Numerical modeling of wave-seabed-structure interaction.
PublicationPraca doktorska przedstawia propozycję nowoczesnego rozwiązania obciążeń hydraulicznych przy uwzględnieniu nieliniowych oddziaływań pomiędzy falą wodną, przepuszczalnym dnem i porowatą konstrukcją morską. Nabrzeże pionowe, falochron podwodny i falochron kompozytowy były obiektem eksperymentów numerycznych, których wyniki były weryfikowane przy użyciu wyników laboratoryjnych (niszczących i nieniszczących). Krótki przegląd bieżącej...
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Partial Molar Volumes of Tetrabutylammonium Perchlorate and Tetraphenylborate in N,N-dimethyl-acetamide, Triethylphosphate and Dimethyl Sulfoxide
PublicationThe densities of tetrabutylammonium perchlorate and tetrabutylammonium tetraphenylborate solutions in N,N-dimethylacetamide, acetonitrile, triethylphosphate, and dimethyl sulphoxide have been measured over the whole electrolyte concentration range at 20, 25, and 30°C. From these densities apparent molar volumes and partial molar volumes of the salts at infinite dilution have been evaluated and used to determine the respective...
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Fundamentals of Physics-Based Surrogate Modeling
PublicationChapter 1 was focused on data-driven (or approximation-based) modeling methods. The second major class of surrogates are physics-based models outlined in this chapter. Although they are not as popular, their importance is growing because of the challenges related to construction and handling of approximation surrogates for many real-world problems. The high cost of evaluating computational models, nonlinearity of system responses,...
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Grand Challenges on the Theory of Modeling and Simulation
PublicationModeling & Simulation (M&S) is used in many different fields and has made many significant contributions. As a field in its own right, there have been many advances in methodologies and technologies. In 2002 a workshop was held in Dagstuhl, Germany, to reflect on the grand challenges facing M&S. Ten years on, a series of M& S Grand Challenge activities are marking a decade of progress and are providing an opportunity to reflect...