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Wyniki wyszukiwania dla: dielectric barrier discharge
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Al-DIAMOND SCHOTTKY TUNNEL DIODES WITH BARRIER HEIGHT CONTROL
PublikacjaFew-nanometer-thick very highly boron-doped p-type layers were fabricated at metal-semiconductor interfaces of Schottky barrier diodes formed with aluminum on polycrystalline diamond. Preliminary results show that hermionically-assisted tunneling mechanism results in lower voltage drops at forward biasing of these diodes than expected for the Al-diamond metal-semiconductor potential barrier B. The effective barrier height Bpeff...
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Microstructure and Dielectric Properties of Barium-vanadate Glasses
PublikacjaThe ac and dc conductivity in barium-vanadate glasses was investigated as a function of temperature and frequency with the use of impedance spectroscopy. The topography and microstructure of glasses were investigated by the means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods. The XRD results show that all samples are amorphous but microscopy investigation reveals that glasses with greater amount of V2O5...
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High-Resolution Discharge Forecasting for Snowmelt and Rainfall Mixed Events
PublikacjaDischarge events induced by mixture of snowmelt and rainfall are strongly nonlinear due to consequences of rain-on-snow phenomena and snowmelt dependence on energy balance. However, they received relatively little attention, especially in high-resolution discharge forecasting. In this study, we use Random Forests models for 24 h discharge forecasting in 1 h resolution in a 105.9 km 2 urbanized catchment in NE Poland: Biala River....
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Reconstruction of 3D image of corona discharge streamer
PublikacjaIn this paper, the method of reconstruction of the 3D structure of streamers in DC positive corona discharge in nozzle-to-plate electrode configuration is presented. For reconstructing of 3D image of corona discharge streamer we propose a stereographical method, where streamers are observed from several directions simultaneously. The multi-directional observation enabled to obtain fine positional coordinates of streamers for a...
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Planar Microwave Bragg Reflector Resonant Dielectric Sensor
PublikacjaIn this paper, a periodic structure is used to design a microwave Bragg reflector with the help of hexagonal lattice, which provides a 5 GHz wide stopband between the low-pass band with cut-off frequency 2.6 GHz and the bandpass response with start and stop frequency 7.8 GHz and 10.5 GHz, respectively. A defect in lattice allows passing a narrowband signal at 6 GHz which is found, from the dispersion relation, to be in the region...
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Dielectric Spectroscopy Studies and Modelling of Piezoelectric Properties of Multiferroic Ceramics
PublikacjaCompounds and solid solutions of bismuth ferrite (BiFeO3)—barium titanate (BaTiO3) system are of great scientific and engineering interest as multiferroic and potential high-temperature lead-free piezoelectric materials. In the present paper, the results of research on the synthesis and characterisation of 0.67Bi1.02FeO3–0.33BaTiO3 (67BFBT) ceramics in terms of crystal structure and dielectric and piezoelectric properties are reported....
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Analysis of the impact of wastewater discharge on recipients: synergistic approach
PublikacjaThe dissertation presents the analysis of chemical and microbial composition of wastewater and examines the impact of wastewater discharge on the environment. Various case studies were analysed: from small settlements in a pristine European Arctic, to large municipal wastewater treatment plants in areas subjected to greater anthropogenic pressure. In order to comprehensively analyse the impact of wastewater discharge on the receiving...
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Modelling of dielectric properties of BiNbO4-based microwave ceramics
PublikacjaIn the present paper results of the studies devoted to computer simulations of dielectric response of electroceramics in a frequency domain as well as analysis of the experimental data are given. As an object of investigations BiNbO4-based microwave ceramics was taken. Simulations of the hypothetical impedance response of the ceramic system were performed under assumption of the brick-layer model. A strategy for analysis and modelling...
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TB11 test for short w-beam road barrier
PublikacjaFEM (Finite Element Method) is well-suited and widely used tool for simulating a range of phenomena: from these with simple and static behaviour, up to those complicated, highly nonlinear and involving many contacts. In present paper we use one of the advantages of FEM: parametric study could be easily performed and is more economical than series of in-situ tests. If recommended practices is carefully followed, results obtained...
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Effects of V2O5 Additive on Structure and Dielectric Properties of BiNbO4 Ceramics
PublikacjaGoal of the present research was to investigate the influence of V2O5 additive on the structure and dielectric properties of BiNbO4 ceramics. To fabricate BiNbO4 ceramics with V2O5 added the solid state reaction route and pressureless sintering was utilized. Thus obtained ceramics was characterized in terms of its microstructure (SEM), chemical composition (EDS), phase composition and crystalline structure (X-ray phase and structural...
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Influence of Dielectric Overlay Dimensions on Performance of Miniaturized ESPAR Antenna
PublikacjaIn this paper, the influence of dielectric overlay size on miniaturized ESPAR antenna performance has been investigated. The dielectric overlay’s main function is antenna’s size reduction but it can also be used to modify its radiation pattern. This creates the possibility of easy adopting antenna parameters to different applications by swapping used overlay. In particular, the lowering of antenna’s main beam elevation direction...
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New Complementary Resonator for Permittivity- and Thickness-Based Dielectric Characterization
PublikacjaThe design of high-performance complementary meta-resonators for microwave sensors featur-ing high sensitivity and consistent evaluation of dielectric materials is challenging. This paper presents the design and implementation of a novel complementary resonator with high sensi-tivity for dielectric substrate characterization based on permittivity and thickness. A comple-mentary crossed arrow resonator (CCAR) is proposed and integrated...
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Effective dielectric constant of two phase dielectric systems
PublikacjaW tym artykule model brick-layer ścianie został rozszerzony na dwufazowe systemy perkolacyjne. Porównano wyniki obliczeń z danymi eksperymentalnymi. Stałe dielektryczne obu faz oraz próg perkolacji pozwala na wyznaczenie efektywnej stałej dielektrycznej systemu dwufazowego.
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Three electrode configuration measurements of electrolyte-diffusion barrier-cathode interface
PublikacjaMeasurements of a system consisting of cathode/doped ceria diffusion barrier/doped zirconia electrolyte were made using two- and three-electrode configuration. Results obtained on a three-electrode measurement configuration were compared with and reflect the results obtained in two-electrode configuration. Three-electrode measurements allowed separating the impact of the symmetrical interface in the investigated system. They also...
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Influence of Sn and Pb Ions Substitutions on Dielectric Properties of Barium Titanate
PublikacjaThe results of the microstructural and dielectric measurements of (Ba1-xPbx)(Ti1-xSnx)O3 (BPTSx) (x = 0, 0.05, 0.10, 0.30) polycrystalline samples are presented. The samples were obtained by means of a high temperature synthesis and their expected stoichiometry was confirmed by energy dispersive spectroscopy (EDS) measurements. The dielectric properties of BPTSx were studied with the use of broadband dielectric spectroscopy. The...
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Experimental and numerical analysis of the modified TB32 crash tests of the cable barrier system
PublikacjaRoad restraint systems, including safety barriers, are one of the means used to improve road safety. Currently, they can be allowed to general use after passing the specific crash tests. However, it is always important and desirable to evaluate their performance under various realistic conditions, which can happen on the roads. In this study, the behaviour of the cable barrier system in impact conditions different than assumed...
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Numerical analysis of lumbar spine injury during road safety barrier collision
PublikacjaPurpose: Enhancing road safety is a critical goal worldwide, necessitating the development of clear standards for road safety systems. This study focuses on lumbar spine (L-spine) compression injuries during collisions with concrete road safety barriers (RSBs). It aims to analyze internal forces during impact to understand L-spine injury biomechanics in such accidents. Methods: The research included a literature review, analyzing...
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Spray pyrolysis of doped-ceria barrier layers for solid oxide fuel cells
PublikacjaGadolinium doped ceria (Ce0.8Gd0.2O2 − x-CGO) layer fabricated by spray pyrolysis is investigated as the diffusion barrier for solid oxide fuel cell. It is deposited between the La0.6Sr0.4FeO3 − δ cathode and the yttria stabilized zirconia electrolyte to mitigate harmful interdiffusion of elements. The parameters of the fabrication process are linked to the measured area specific resistances of the symmetrical cells and the efficiency...
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Dissociative ionization dynamics of dielectric gas C3F7CN
PublikacjaFluoronitrile C3F7CN is a promising candidate for the replacement of SF6 dielectric gas in high-voltage insulation. We present a combined experimental and theoretical study on its ionization dynamics probed in the 0-100 eV energy range. We exploited the total ion collection technique to determine the absolute ionization cross section, mass spectrometry to determine the fragment branching ratios and ab initio nonadiabatic molecular...
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Novel Complementary Resonator for Dielectric Characterization of Substrates Based on Permittivity and Thickness
PublikacjaThis paper presents a novel complementary resonator featuring high sensitivity, low fabrication cost, and improved performance. The proposed structure consists of a complementary concentric square and circular ring resonator (CCSCRR) with multiple splits to enhance the inductance of the resonator. The proposed CCSCRR is coupled to a microstrip transmission line with an impedance of fifty ohms to create a high-sensitivity sensor....