Filtry
wszystkich: 32361
-
Katalog
- Publikacje 10596 wyników po odfiltrowaniu
- Czasopisma 80 wyników po odfiltrowaniu
- Konferencje 10 wyników po odfiltrowaniu
- Osoby 158 wyników po odfiltrowaniu
- Wynalazki 15 wyników po odfiltrowaniu
- Projekty 5 wyników po odfiltrowaniu
- Laboratoria 1 wyników po odfiltrowaniu
- Kursy Online 132 wyników po odfiltrowaniu
- Wydarzenia 8 wyników po odfiltrowaniu
- Dane Badawcze 21356 wyników po odfiltrowaniu
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: BODY OF REVOLUTION (BOR), CYLINDRICAL WAVEGUIDES, FINITE-ELEMENT METHOD (FEM), GENERALIZED IMPEDANCE MATRIX (GIM), PERIODIC STRUCTURES, SCATTERING, WAVEGUIDE DISCONTINUITIES.
-
Multi-objective design optimization of antennas for reflection, size, and gain variability using kriging surrogates and generalized domain segmentation
PublikacjaCost-efficient multi-objective design optimization of antennas is presented. The framework exploits auxiliary data-driven surrogates, a multi-objective evolutionary algorithm for initial Pareto front identification, response correction techniques for design refinement, as well as generalized domain segmentation. The purpose of this last mechanism is to reduce the volume of the design space region that needs to be sampled in order...
-
Selected problems of earth fault loop impedance testing in circuits fed from UPS
PublikacjaIn the paper a principle of earth fault loop impedance testing in low voltage systems has been presented. Selected factors, influencing accuracy of the testing, are indicated. A structure of UPS of VFI-type and the problem of impedance testing in circuits with such type of UPS are discussed.
-
Linear impedance of 50(2Bi2O3-V2O5)-50SrB4O7 glass heat treated at 693 K measured with impedance spectroscopy method at low temperature region
Dane BadawczeThe linear electrcial properties of 50(2Bi2O3-V2O5)-50SrB4O7 glass heat treated at 693 K was measured by impedance spectroscopy method.
-
Linear impedance of 50(2Bi2O3-V2O5)-50SrB4O7 glass heat treated at 693 K measured with impedance spectroscopy method at high temperature region
Dane BadawczeThe linear electrcial properties of 50(2Bi2O3-V2O5)-50SrB4O7 glass heat treated at 693 K was measured by impedance spectroscopy method.
-
Analysis of circular cavity with cylindrical objects
PublikacjaArtykuł opisuje analizę rozpraszania fali elektromagnetycznej na obiektach cylindrycznych rozmieszczonych dowolnie w strukturze rezonatora. Analiza oparta jest na metodzie dopasowania rodzajów. Dokładność i poprawność metody jest zweryfikowana poprzez porównanie uzyskanych wyników z wynikami otrzymanymi z metod alternatywnych i własnych pomiarów wykonanych układów.
-
Simulation of buckling process of cylindrical metal silos with flat sheets containing bulk solids.
PublikacjaW artykule symulowano proces wyboczenia w cylindrycznych metalowych silosach z płaskich blach wypełnionych materiałem sypkim. Wykonano analizy nieliniowe stosując MES dla silosów pustych i napełnionych. Zbadano wpływ wstępnych imperfekcji geometrycznych na nośność wyboczeniowo. Wyniki porównano z wynikami doświadczalnymi w Uniwersytecie Karlsruhe.
-
Three modes of electrochemical impedance spectroscopy measurements performed on vanadium redox flow battery
PublikacjaThis article presents an innovative approach to monitor working redox flow batteries using dynamic electrochemical impedance spectroscopy, diverging from the commonly sequential impedance methods carried out under potentiostatic or galvanostatic conditions close to the open circle voltage. The authors introduce a fresh variation of dynamic impedance measurement that leverages an amplitude-modulated multi-frequency alternating current...
-
An algorithmic approach to estimating the minimal number of periodic points for smooth self-maps of simply-connected manifolds
PublikacjaFor a given self-map f of M, a closed smooth connected and simply-connected manifold of dimension m 4, we provide an algorithm for estimating the values of the topological invariant D^m_r [f], which equals the minimal number of r-periodic points in the smooth homotopy class of f. Our results are based on the combinatorial scheme for computing D^m_r [f] introduced by G. Graff and J. Jezierski [J. Fixed Point Theory Appl. 13 (2013),...
-
Time evolution of Electrochemical Impedance spectra of cathodically protected steel in artificial seawater
PublikacjaUsability of Electrochemical Impedance Spectroscopy data for better cathodic protection control was investigated. Carbon steel – S235JR2 grade specimen were exposed in artificial seawater environment. Samples were polarized and their potentials corresponded to four different cathodic protection degrees. Time evolution of Electrochemical Impedance spectra was investigated. Goodness of fit function (X2) was analysed in terms of proper...
-
TOTAL CROSS SECTIONS FOR ELECTRON SCATTERING FROM SELECTED HYDROCARBONS: THE SUBSTITUTIONAL AND ADDITIVITY EFFECTS
PublikacjaTotal cross sections (TCS) for electron scattering from selected alkyne molecules, ethylene and its derivatives are compared. All cross sections have been measured in a wide energy range, from about 1 eV up to 370 eV, with the same electrostatic electron spectrometer. The substitutional and additivity effects are indicated and discussed.
-
WIND AND STRUCTURES
Czasopisma -
Bridge Structures
Czasopisma -
Earthquakes and Structures
Czasopisma -
Small Structures
Czasopisma -
Study of Direct Methanol Fuel Cell Process Dynamics Using Dynamic Electrochemical Impedance Spectroscopy
PublikacjaA new technique, which was developed to characterize the direct methanol fuel cell under work conditions, has been presented in this paper. The impedance measurements were made using dynamic electrochemical impedance spectroscopy research technique in the galvanostatic mode, using multiple sinusoidal excitation. Obtained results show, that together with an increase of the temperature and working load, the global impedance...
-
A Direct Modulation for Matrix Converters based on the Onecycle Atomic operation developed in Verilog HDL.
PublikacjaThis paper presents a fast direct Pulse Width Modulation (PWM) algorithm for the Conventional Matrix Converters (CMC) developed in Verilog Hardware Description language (HDL). All PWM duty cycle calculations are performed in one cycle by an atomic operation designed as a digital module using FPGA basic blocks. The algorithm can be extended to any number of output phase. The improved version of the discontinuous Direct Analytic...
-
A two-scale (FEM-DEM) approach for concrete
PublikacjaArtykuł omawia dwu-skalowe podejście do betonu przy wykorzystaniu modelu Mes i DEM. Metodę elementów skończonych zastosowano na poziomie makro. Na poziomie mikro zastosowano metodę elementów dyskretnych. Macierz sztywności wyznaczono na podstawie tensora naprężeń wyznaczonego w skali mikro. Wyniki numeryczne dwusalowe porównano z wynikami dyskretnymi dla całego obszaru.
-
Body Movement and Dance in Psychotherapy
Czasopisma -
Advances in Mind-Body Medicine
Czasopisma -
Distributed NVRAM Cache – Optimization and Evaluation with Power of Adjacency Matrix
PublikacjaIn this paper we build on our previously proposed MPI I/O NVRAM distributed cache for high performance computing. In each cluster node it incorporates NVRAMs which are used as an intermediate cache layer between an application and a file for fast read/write operations supported through wrappers of MPI I/O functions. In this paper we propose optimizations of the solution including handling of write requests with a synchronous mode,...
-
Comparing Arbitrary Unrooted Phylogenetic Trees Using Generalized Matching Split Distance
PublikacjaIn the paper, we describe a method for comparing arbitrary, not necessary fully resolved, unrooted phylogenetic trees. Proposed method is based on finding a minimum weight matching in bipartite graphs and can be regarded as a generalization of well-known Robinson-Foulds distance. We present some properties and advantages of the new distance. We also investigate some properties of presented distance in a common biological problem...
-
A Dirac delta-type orthogonality relation for the on-the-cut generalized associated Legendre functions of the first kind with imaginary second upper indices
PublikacjaThe orthogonality relation for the on-the-cut generalized associated Legendre functions of the first kind with imaginary second upper indices is evaluated in a closed form. It is found to be proportional to a sum of two terms, both depending on the second upper indices and containing the Dirac delta distribution.
-
Nonlinear impedance of 50(2Bi2O3-V2O5)-50SrB4O7 glass heat treated at 693 K measured with impedance spectroscopy method at high temperature region
Dane BadawczeThe nonlinear electrcial properties of 50(2Bi2O3-V2O5)-50SrB4O7 glass heat treated at 693 K was measured by impedance spectroscopy method.
-
Nonlinear impedance of 50(2Bi2O3-V2O5)-50SrB4O7 glass heat treated two times measured with impedance spectroscopy method at high temperature region
Dane BadawczeThe nonlinear electrcial properties of 50(2Bi2O3-V2O5)-50SrB4O7 glass heat treated two times was measured by impedance spectroscopy method.
-
The use of Response Surface Methodology for reliability estimation of composite engineering structures
PublikacjaStability loss is one of the key issues in the analysis of shells made of composite materials. This paper aims at finding the variation of the critical or limit value of the load resulting from geometric imperfections. An axially compressed 16-layer cylindrical panel model is considered. The imperfections of the panel are simulated as random fields. The parameters of these fields are used as the basic variables of the reliability...
-
Biosilica from sea water diatoms algae—electrochemical impedance spectroscopy study
PublikacjaHere, we report on an electrochemical impedance study of silica of organic origin as an active electrode material. The electrode material obtained from carbonized marine biomass containing nanoporous diatoms has been characterised by means of XRD, IR, SEM and EIS. Dif- ferent kinds of crystallographic phases of silica as a result of thermal treatment have been found. The electrode is electrochemically stable during subsequent cyclic...
-
TOTAL CROSS SECTION MEASUREMENTS FOR ELECTRON SCATTERING ON METHYL FORMATE (HCOOCH3) MOLECULE: METHYLATION EFFECT
PublikacjaWe present the absolute total cross section (TCS) for electron scattering from the methyl formate (HCOOCH3) molecule measured in the 10-300 eV energy range, with electrostatic electron spectrometer working in the linear transmission mode. Comparison of TCS for the HCOOCH3 molecule with that measured earlier for the formic acid (HCOOH) compound manifests the methylation effect i.e. the response of the electron scattering dynamics...
-
The Design of Cavity Resonators and Microwave Filters Applying Shape Deformation Techniques
PublikacjaThis article introduces shape deformation as a new approach to the computer-aided design (CAD) of high-frequency components. We show that geometry deformation opens up new design possibilities and offers additional degrees of freedom in the 3-D modeling of microwave structures. Such design flexibility is highly desirable if the full potential of additive manufacturing (AM) is to be exploited in the fabrication of RF and microwave...
-
Machine-Learning-Powered EM-Based Framework for Efficient and Reliable Design of Low Scattering Metasurfaces
PublikacjaPopularity of metasurfaces has been continuously growing due to their attractive properties including the ability to effectively manipulate electromagnetic (EM) waves. Metasurfaces comprise optimized geometries of unit cells arranged as a periodic lattice to obtain a desired EM response. One of their emerging application areas is the stealth technology, in particular, realization of radar cross section (RCS) reduction. Despite...
-
Existence of periodic orbits for a perturbed vector field
PublikacjaPrzy nałożeniu pewnego warunku na odwzorowanie Poincarego, wyrażonego w języku indeksów iteracji, dowodzi się istnienia orbit periodycznych dla zaburzonego pola wektorowego.
-
Graph decomposition for improving memoryless periodic exploration
PublikacjaW ostatnich latach często badanym problem jest eksploracja anonimowych grafów z lokalnymi etykietami portów przy każdym wierzchołku. Niedawno pokazano [Czyzowicz et al., Proc. SIROCCO'09], że dla każdego grafu istnieje poetykietowanie prowadzące do eksploracji przez automat bezpamięciowy z okresem co najwyżej 13n/3. W niniejszej pracy poprawiamy to ograniczenie do 4n-2, stosując całkowicie nową technikę dekompozycji grafu.
-
Elastostatic problems in multicomponent, multilayered periodic composites
Publikacja -
Periodic Points for Sphere Maps Preserving MonopoleFoliations
PublikacjaLet S^2 be a two-dimensional sphere. We consider two types of its foliations with one singularity and maps f:S^2→S^2 preserving these foliations, more and less regular. We prove that in both cases f has at least |deg(f)| fixed points, where deg(f) is a topological degree of f. In particular, the lower growth rate of the number of fixed points of the iterations of f is at least log|deg(f)|. This confirms the Shub’s conjecture in...
-
The impedance of hydrogen oxidation reaction in a proton exchange membrane fuel cell in the presence of carbon monoxide in hydrogen stream
PublikacjaEvaluation of performance of a proton exchange membrane fuel cell, which is affected by carbon monoxide that pollutes the hydrogen stream, was presented. This influence was studied for carbon monoxide concentration of 125–325 ppb, which are close to values specified in ISO 14687:2019 standard. Performed studies provided crucial information for further development of fuel cell as an energy source for automotive application. Impedance...
-
Nonlinear Impedance as Possible Result of Ion-Polaron Interaction in Cu2O-Al2O3-SiO2 Glass
PublikacjaNonlinear a.c. impedance measurements were performed in Cu2O-Al2O3-SiO2 glass in wide frequency range. The obtained results shows that a large nonlinearity in the impedance signal is observed at moderate electric fields of an order 1V/mm. The contents of the third harmonics reaches about 10% and strongly depends on temperature and frequency. The investigated glass exhibits mixed electronic-ionic conductivity. Electronic conduction...
-
Comparison of Impedance-Source Networks for Two and Multilevel Buck–Boost Inverter Applications
Publikacjampedance-source networks are an increasingly popular solution in power converter applications, especially in single-stage buck-boost power conversion to avoid additional front-end dc-dc power converters. In the survey papers published, no analytical comparisons of different topologies have been described, which makes it difficult to choose the best option. Thus, the aim of this paper is to present a comprehensive analytical comparison...
-
Stability & Dynamics of Ship and Offshore Structures II W2021/22
Kursy OnlineLecture and Lab classes - Stability & Dynamics of Ship and Offshore Structures II W2021/22
-
Tunable Waveguide Filter with Bow-Tie Metallic Posts.
PublikacjaBadanie i synteza filtru falowodowego zawiewrającego metalowe rezonatory motylkowe (Bow-Tie). Wykorzystano zmodyfikowaną procedurę iteracyjną i metodę dopasowania rodzajów w celu rozwiązania problemu brzegowego na pojedynczej sekcji filtru i określenie pola rozproszonego od rezonatora motylkowego. Obrót i przemieszczenie opisywane struktury w złączu falowodowym umożliwia zmianę odpowiedzi częstotliwościowych układu. Efekt rotacji...
-
Automated design of waveguide filters with frequency-dependent couplings.
PublikacjaW artykule zaproponowano szybką technikę pozwalającą na automatyczne projektowanie filtrów falowodowych ze sprzężeniami zależnymi od częstotliwości. Procedura optymalizacyjna jest trójetapowa z różnymi funkcjami celu w każdym etapie.
-
Rectangular waveguide junctions with posts of negative isotropic media.
PublikacjaW pracy przedstawiono wpływ ujemnej przenikalności elektrycznej i magnetycznej rezonatorów cylindrycznych umieszczonych w czteroportowym prostokątnym złączu falowodowym na jego parametry odbicia i transmisji. Wykorzystano zmodyfikowaną procedurę iteracyjną i metodę dopasowania rodzajów w celu określenia macierzy rozproszenia w/w złącza.
-
Structural Dynamics and Stability of Composite Structures
PublikacjaThis an editorial for a special Issue devoted to the application of dynamic and stability analysis of composite structures. In structural applications, past few decades have seen outstanding advances in the use of composite materials including Functionally Graded Materials (FGM). Most structures, whether they are used in civil, marine, or aerospace engineering, are subjected to dynamic loads during their operation.Therefore, dynamic...
-
Rapid determination of multiple aminoglycoside antibiotics in veterinary formulations by ion-pair chromatography coupled with evaporative light scattering detection
PublikacjaA fast and simple method for simultaneous determination of eight aminoglycoside antibiotics using ion-pairing liquid chromatography (IPLC) coupled with evaporative light scattering detection (ELSD) has been developed and validated. Separation of amikacin, apramycin, gentamicin (as a sum of gentamicin C1, C2 and C1A), kanamycin A, neomycin B, paromomycin, streptomycin and tobramycin was achieved using C18 column with H2O and MeOH/acetone,...
-
Numerical analysis of elastic wave propagation in unbounded structures
Publikacja -
Matrix solid-phase dispersion (MSPD) as simple and useful sample preparation technique for determination of polybrominated diphenyl ethers (PBDEs) in dust
PublikacjaIn the present study a novel analytical procedure for the determination of polybrominated diphenylethers in dust samples was developed.The main aim of the research was the selection of the optimum conditions of the matrix solid-phasedispersion before thefinal determination of polybrominated diphenyl ethers in dust samples. In order toassess the best usefulness of this technique, a favourable ratio of sample amount to the mass ofdispersing...
-
Design of High-Performance Scattering Metasurfaces through Optimization-Based Explicit RCS Reduction
PublikacjaThe recent advances in the development of coding metasurfaces created new opportunities in realization of radar cross section (RCS) reduction. Metasurfaces, composed of optimized geometries of meta-atoms arranged as periodic lattices, are devised to obtain desired electromagnetic (EM) scattering characteristics. Despite potential benefits, their rigorous design methodologies are still lacking, especially in the context of controlling...
-
Reliability of Structures - 3rd semester, Civil Engineering - Winter Semester 2023/24
Kursy OnlineReliability of Structures, 2nd grade studies, Civil Engineering
-
Nonlinear impedance of glass 40Bi2VO5.5-60SrB4O7 annealed at 593 K and next fully crystallized was measured with impedance spectroscopy method at high temperature region
Dane BadawczeThe nonlinear electrcial properties of glass 40Bi2VO5.5-60SrB4O7 annealed at 593 K and next fully crystallized was measured by impedance spectroscopy method.
-
A Model-Order Reduction Approach for Electromagnetic Problems With Nonaffine Frequency Dependence
PublikacjaThe aim of this paper is to present a novel model-order reduction (MOR) technique for the efcient frequency-domain nite-element method (FEM) simulation of microwave components. It is based on the standard reduced-basis method, but the subsequent expansion frequency points are selected following the so-called sparsied greedy strategy. This feature makes it especially useful to perform a fast-frequency sweep of problems that lead...
-
Durability evaluation of technical fabrics
PublikacjaA thorough examination of the influence of the conditions of use on the mechanical properties of technical fabrics is proposed. Laboratory experiments (uniaxial tensile, rheological, cyclic and biaxial tensile tests) have been conducted and the material’s parameters for Finite Element Method (FEM) simulations have been identified. Various constitutive models of technical fabrics are investigated and compared. On the basis of these...
-
User Orientation Detection in Relation to Antenna Geometry in Ultra-Wideband Wireless Body Area Networks Using Deep Learning
PublikacjaIn this paper, the issue of detecting a user’s position in relation to the antenna geometry in ultra-wideband (UWB) off-body wireless body area network (WBAN) communication using deep learning methods is presented. To measure the impulse response of the channel, a measurement stand consisting of EVB1000 devices and DW1000 radio modules was developed and indoor static measurement scenarios were performed. It was proven that for...