Search results for: ELECTRICAL POTENTIAL
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Nonlinear Model of Synchronous Generator for Autonomous Electrical Power Systems Analysis
PublicationThis paper presents the nonlinear lookup table model for synchronous generator (SG) analysis. The saturation effects of the SG magnetic circuit have been considered. The saturated characteristic of the SG magnetic circuit are based on the open circuit saturation curve for magnetizing inductances. The model has been implemented into the Synopsys/Saber software using the MAST modelling language. To implement the no-load voltage characteristic...
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Nonlinear model of a synchronous generator for analysis of more electric aircraft power systems
PublicationA nonlinear model for studying a variable-speed synchronous generator (SG) in more electric aircraft (MEA) power system has been developed. The saturation effects of the SG magnetic circuit have been considered. The model has been implemented in the Synopys/Saber simulation environment. The modelling language MAST has been used to elaborate the SG model. The model exhibit a network with the same number of external terminals/ports...
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An experimental study of self-sensing concrete enhanced with multi-wall carbon nanotubes in wedge splitting test and DIC
PublicationConcrete is the worldwide most utilized construction material because of its very good performance, forming ability, long-term durability, and low costs. Concrete is a brittle material prone to cracking. Extensive cracking may impact durability and performance over time considerably. The addition of a small amount of carbon nanotubes (CNT) increases the concrete’s overall electrical conductivity, enabling internal structure...
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Structure and thermoelectric properties of Bi–Te alloys obtained by novel method of oxide substrates reduction
PublicationA novel method of thermoelectric materials fabrication has been developed. Oxide reagents have been melted at high temperature in air, quenched, milled to powder and reduced in hydrogen to form Bi–Te alloys. Structural and thermoelectric properties of samples have been investigated depending on initial composition and temperature of reduction process. Sample 25Bi2O3–75TeO2 reduced at 340 °C for 10 h has been found to be a p-type...
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Optimization of Graphene Oxide Synthesis and Its Reduction
PublicationIn this article, we present the review of the chemical methods of synthesis of graphene oxide and its reduction in order to obtain the so-called reduced graphene oxide (rGO) whose properties are similar to those of pure graphene. We also present our experiments and the results in this field and the comparison of the efficiency of different methods of synthesis as well as the reduction of graphene oxide. To characterize the obtained...
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Scrutiny of power grids by penetrating PV energy in wind farms: a case study of the wind corridor of Jhampir, Pakistan
PublicationThis study examines the problems caused by intermittent renewable energy sources, especially wind farms, and suggests a different solar energy penetration strategy to improve their loading capacity. The study uses real-time data from a wind farm in Jhampir, Pakistan, to analyse and assess various aspects of grid stations connected to wind farms. Electrical Transient Analyzer Program is used to validate the results by linking...
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Novel structure and design of compact UWB slot antenna
PublicationIn this paper, a novel structure of a compact UWB slot antenna is presented along with a simulation-driven design optimization algorithm for adjusting geometry parameters of the device. Our primary objective is to obtain small footprint of the structure while maintaining its acceptable electrical performance. It is achieved by introducing sufficiently large number of geometry degrees of freedom, including increased number of parameterized...
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Polynomial analysis as a new way of describing dynamic impedance spectra – Differential and relative impedance spectra
PublicationModel measurements of an equivalent electrical system were carried out using the technique of Dynamic Electrochemical Impedance Spectroscopy. The measurement took the form of potentiodynamic changes imposed on the tested system. Using the possibility of continuous impedance measurements, an attempt was made to develop an original and innovative method of analyzing impedance spectrograms, which is termed polynomial analysis. As...
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Influence of temperature and nitrogen pressure on the test without active gases for high-temperature proton exchange membrane fuel cells
PublicationHigh-Temperature Proton-Exchange Membrane Fuel Cells (HT-PEMFCs) are a candidate for electrical energy supply devices in more and more applications. Most notably in the aeronautic industry. Before any use, an HT-PEMFC is preheated and after that supplied with its active gases. Only at this state, the diagnostics can be performed. A method of testing not requiring a complete start-up would be beneficial for many reasons. This article...
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Structure and transport properties of donor-doped barium strontium cobaltites
PublicationIn this work, Nb-substituted barium strontium cobaltites Ba0.5Sr0.5Co1-xNbxO3-δ (x = 0 – 0.4) have been fabricated and studied. The structural analysis showed that the Nb content influences the lattice constant as well as the distance between the (Co, Nb) and oxygen atoms. The study of morphology of samples showed that the Nb content does not change the porosity, grain size and morphology of the ceramics. The total electrical conductivity...
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High-Temperature Structural and Electrical Properties of BaLnCo2O6 Positrodes
PublicationThe application of double perovskite cobaltites BaLnCo2O6−δ (Ln = lanthanide element) in electrochemical devices for energy conversion requires control of their properties at operating conditions. This work presents a study of a series of BaLnCo2O6−δ (Ln = La, Pr, Nd) with a focus on the evolution of structural and electrical properties with temperature. Symmetry, oxygen non-stoichiometry, and cobalt valence state have been examined...
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Application analysis of a hybrid solid oxide fuel cell-gas turbine system for marine power plants
PublicationThe results of theoretical studies of the possibilities of using hybrid solid oxide fuel cell–gas turbine (SOFC-GT) systems for marine power plants are presented. A 500 kW auxiliary marine power plant scheme using stacks of SOFCs in combination with a regenerative gas turbine operating with over-expansion based on our recent patent application is proposed. The results of mathematical modelling showed the opportunity to obtain a...
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Scrutiny of power grids by penetrating PV energy in wind farms: a case study of the wind corridor of Jhampir, Pakistan
PublicationThis study examines the problems caused by intermittent renewable energy sources, especially wind farms, and suggests a different solar energy penetration strategy to improve their loading capacity. The study uses real-time data from a wind farm in Jhampir, Pakistan, to analyse and assess various aspects of grid stations connected to wind farms. Electrical Transient Analyzer Program is used to validate the results by linking these...
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Conversion of Biomass and Municipal Wastes into Syngas and Hydrogen using Highly Preheated Agent (HTAG)
PublicationGasification is considered to be one of the most promising energy recovery technologies for the widespread utilization of biomass and wastes. During this process raw feedstock is converted into a combustible gas, which can then be burnt to produce thermal energy, or to run engines for mechanical or electrical power. The studies of biomass gasification demonstrate it as a friendly alternative to fossil fuels as one of renewable...
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Modeling the impact of rotor movement on non-linearity of motor currents waveforms in high-speed PMSM drives
PublicationMotor current measurement techniques as well as predictive control algorithms for electric drives rely on an assumption of linear motor currents changes resulting from constant inverter output voltages. Recent research has reported that this assumption does not hold in motors with short electrical time constant, and in drives whose rotor position advances substantially during a control period. This paper proposes a simulation model...
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Objective relaxation algorithm for reliable simulation-driven size reduction of antenna structure
PublicationThis letter investigates reliable size reduction of antennas through electromagnetic-driven optimization. It is demonstrated that conventional formulation of the design task by direct footprint miniaturization with imposing constraints on electrical performance parameters may not lead to optimum results. The reason is that—in a typical antenna structure—only a few geometry parameters explicitly determine the antenna footprint,...
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Selecting wells for an optimal design of groundwater monitoring network based on monitoring priority map: A Kish Island case study
PublicationThis paper presents a novel approach, i.e. a combination of gamma test and monitoring priority map, for optimal design of groundwater monitoring network (GMN) by considering the cumulative effects of industries, human activities, and natural factors on the groundwater quality. The proposed method was successfully applied to design an optimal network for groundwater salinity monitoring on Kish Island, Persian Gulf. The priority...
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Electrophoretic co-deposition of Mn1.5Co1.5O4, Fe2O3 and CuO: Unravelling the effect of simultaneous addition of Cu and Fe on the microstructural, thermo-mechanical and corrosion properties of in-situ modified spinel coatings for solid oxide cell interconnects
PublicationA systematic microstructural, thermo-mechanical and electrical characterization of simultaneous Fe–Cu doped Mn–Co spinel coatings processed by electrophoretic co-deposition on Crofer 22 APU is here reported and discussed. An innovative approach for the simultaneous electrophoretic deposition of three spinel precursors is designed, conceived and optimised, with the aim of outlining time- and energy-saving spinel modification routes....
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The unstable thermoelectric effect in non-stoichiometric Cu2Se during the non-equilibrium phase transition
PublicationThe superionic α ↔ β phase transition in Cu1.96Se thermoelectric material is investigated by means of thermal analysis (DSC) and measurements of Seebeck coefficient and electrical conductivity. Results of the DSC measurements with 1–10 K/min heating and cooling rates show that the material is close to the equilibrium phase composition during the transformation. However, the kinetic limitation of the process exists, which is indicated...
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Preparation and characterisation of iron substituted Mn1.7Cu1.3-xFexO4 spinel oxides (x = 0, 0.1, 0.3, 0.5)
PublicationSpinel oxides with the general formula Mn1.7Cu1.3-xFexO4 (x= 0, 0.1, 0.3, 0.5) were prepared and evaluated in this work for their properties at high temperatures. The effect of partially substituting Cu by Fe has not been studied so far for this group of materials and is thus evaluated in this work. Mn1.7Cu1.3-xFexO4 powders were synthesised by a soft chemistry process and studied in terms of crystallographic phase analysis, electrical...
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A Wind Energy Conversion System Based on a Generator with Modulated Magnetic Flux
PublicationIn this work, the concept of an energy conversion system for wind turbines based on the modified permanent magnet synchronous generator (PMSG) is presented. In the generator, a pair of three-phase windings is used, one of which is connected in a “star” and the second in a “delta” configuration. At the outputs of both windings, two six-pulse uncontrolled (diode) rectifiers are included. These rectifiers are mutually coupled by a...
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Structural and catalytic properties of ceria layers doped with transition metals for SOFCs fueled by biogas
PublicationThe aim of this paper was to investigate an influence of the nanocrystalline Ce0.8A0.2O2-δ (A = Mn, Fe, Co, Ni, Cu) materials on the direct internal reforming of biogas in SOFC. Structural analysis of fabricated compounds has been done. An in-situ analysis of a composition of outlet gases from operating SOFC was performed using FTIR spectroscopy with simultaneous electrical tests. It was found out, that type of dopant strongly...
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Values and problems analysis – Lower Sopot (Dolny Sopot) district case study, study proposal no 1, March 2021
Open Research DataThe data presents results of work within the studies of the development possibilities of the district in the context of the city, Lower Sopot (Dolny Sopot) district, study proposal no 1, from March 2021. The goal of the research process was to present the values and problems analysis of the area located in Lower Sopot (Dolny Sopot) district in the context...
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Vision of the development of transformations in the district – Lower Sopot (Dolny Sopot) district case study, study proposal no 1, April 2021
Open Research DataThe data presents results of work within the studies of the vision of the district in the context of the city, Lower Sopot (Dolny Sopot) district, study proposal no 1, from April 2021. The goal of the research process was to present the future image of the neighborhood and initial ideas of the development of transformations of the area located in Lower...
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Vision of the development of transformations in the district – Lower Sopot (Dolny Sopot) district case study, study proposal no 3, April 2021
Open Research DataThe data presents results of work within the studies of the vision of the district in the context of the city, Lower Sopot (Dolny Sopot) district, study proposal no 3, from April 2021. The goal of the research process was to present the future image of the neighborhood and initial ideas of the development of transformations of the area located in Lower...
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Values and problems analysis – Lower Sopot (Dolny Sopot) district case study, study proposal no 3, March 2021
Open Research DataThe data presents results of work within the studies of the development possibilities of the district in the context of the city, Lower Sopot (Dolny Sopot) district, study proposal no 3, from March 2021. The goal of the research process was to present the values and problems analysis of the area located in Lower Sopot (Dolny Sopot) district in the context...
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Values and problems analysis – Lower Sopot (Dolny Sopot) district case study, study proposal no 5, March 2021
Open Research DataThe data presents results of work within the studies of the development possibilities of the district in the context of the city, Lower Sopot (Dolny Sopot) district, study proposal no 5, from March 2021. The goal of the research process was to present the values and problems analysis of the area located in Lower Sopot (Dolny Sopot) district in the context...
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Values and problems analysis – Lower Sopot (Dolny Sopot) district case study, study proposal no 2, March 2021
Open Research DataThe data presents results of work within the studies of the development possibilities of the district in the context of the city, Lower Sopot (Dolny Sopot) district, study proposal no 2, from March 2021. The goal of the research process was to present the values and problems analysis of the area located in Lower Sopot (Dolny Sopot) district in the context...
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Vision of the development of transformations in the district – Lower Sopot (Dolny Sopot) district case study, study proposal no 4, April 2021
Open Research DataThe data presents results of work within the studies of the vision of the district in the context of the city, Lower Sopot (Dolny Sopot) district, study proposal no 4, from April 2021. The goal of the research process was to present the future image of the neighborhood and initial ideas of the development of transformations of the area located in Lower...
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Vision of the development of transformations in the district – Lower Sopot (Dolny Sopot) district case study, study proposal no 2, April 2021
Open Research DataThe data presents results of work within the studies of the vision of the district in the context of the city, Lower Sopot (Dolny Sopot) district, study proposal no 2, from April 2021. The goal of the research process was to present the future image of the neighborhood and initial ideas of the development of transformations of the area located in Lower...
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Vision of the development of transformations in the district – Lower Sopot (Dolny Sopot) district case study, study proposal no 5, April 2021
Open Research DataThe data presents results of work within the studies of the vision of the district in the context of the city, Lower Sopot (Dolny Sopot) district, study proposal no 5, from April 2021. The goal of the research process was to present the future image of the neighborhood and initial ideas of the development of transformations of the area located in Lower...
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Values and problems analysis – Lower Sopot (Dolny Sopot) district case study, study proposal no 4, March 2021
Open Research DataThe data presents results of work within the studies of the development possibilities of the district in the context of the city, Lower Sopot (Dolny Sopot) district, study proposal no 4, from March 2021. The goal of the research process was to present the values and problems analysis of the area located in Lower Sopot (Dolny Sopot) district in the context...
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Vision of the development of transformations in the district – Lower Sopot (Dolny Sopot) district case study, study proposal no 6, April 2021
Open Research DataThe data presents results of work within the studies of the vision of the district in the context of the city, Lower Sopot (Dolny Sopot) district, study proposal no 6, from April 2021. The goal of the research process was to present the future image of the neighborhood and initial ideas of the development of transformations of the area located in Lower...
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Vision of the development of transformations in the district – Gdańsk-Lower City (Dolne Miasto) district case study, study proposal no 2, April 2021
Open Research DataThe data presents results of work within the studies of the vision of the district in the context of the city, Gdańsk-Lower City (Dolne Miasto) district, study proposal no 2, from April 2021. The goal of the research process was to present the future image of the neighborhood and initial ideas of the development of transformations of the area located...
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Values and problems analysis – Gdańsk-Lower City (Dolne Miasto) district case study, study proposal no 1, March 2021
Open Research DataThe data presents results of work within the studies of the development possibilities of the district in the context of the city, Gdańsk-Lower City (Dolne Miasto) district, study proposal no 1, from March 2021. The goal of the research process was to present the values and problems analysis of the area located in Gdańsk-Lower City (Dolne Miasto) district...
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Vision of the development of transformations in the district – Gdańsk-Lower City (Dolne Miasto) district case study, study proposal no 1, April 2021
Open Research DataThe data presents results of work within the studies of the vision of the district in the context of the city, Gdańsk-Lower City (Dolne Miasto) district, study proposal no 1, from April 2021. The goal of the research process was to present the future image of the neighborhood and initial ideas of the development of transformations of the area located...
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Values and problems analysis – Lower Sopot (Dolny Sopot) district case study, study proposal no 6, March 2021
Open Research DataThe data presents results of work within the studies of the development possibilities of the district in the context of the city, Lower Sopot (Dolny Sopot) district, study proposal no 6, from March 2021. The goal of the research process was to present the values and problems analysis of the area located in Lower Sopot (Dolny Sopot) district in the context...
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Vision of the development of transformations in the district – Gdańsk-Lower City (Dolne Miasto) district case study, study proposal no 3, April 2021
Open Research DataThe data presents results of work within the studies of the vision of the district in the context of the city, Gdańsk-Lower City (Dolne Miasto) district, study proposal no 3, from April 2021. The goal of the research process was to present the future image of the neighborhood and initial ideas of the development of transformations of the area located...
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Values and problems analysis – Gdańsk-Lower City (Dolne Miasto) district case study, study proposal no 3, March 2021
Open Research DataThe data presents results of work within the studies of the development possibilities of the district in the context of the city, Gdańsk-Lower City (Dolne Miasto) district, study proposal no 3, from March 2021. The goal of the research process was to present the values and problems analysis of the area located in Gdańsk-Lower City (Dolne Miasto) district...
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Values and problems analysis – Gdańsk-Lower City (Dolne Miasto) district case study, study proposal no 2, March 2021
Open Research DataThe data presents results of work within the studies of the development possibilities of the district in the context of the city, Gdańsk-Lower City (Dolne Miasto) district, study proposal no 2, from March 2021. The goal of the research process was to present the values and problems analysis of the area located in Gdańsk-Lower City (Dolne Miasto) district...
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Rattling-enhanced superconductivity in MV2Al20 (M = Sc, Lu, Y) intermetallic cage compounds
PublicationPolycrystalline samples of four intermetallic compounds: MV2Al20 (M=Sc, Y, La, and Lu) were synthesized using an arc-melting technique. The crystal structures were analyzed by means of powder x-ray diffraction and Rietveld analysis, and the physical properties were studied by means of heat capacity, electrical resistivity, and magnetic susceptibility measurements down to 0.4 K. For ScV2Al20, LuV2Al20, and YV2Al20, superconductivity...
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Chemical modifications of graphene and their influence on properties of polyurethane composites: a review
PublicationPolyurethane composites are materials of great interest nowadays due to their wide range of available forms and applications in industry. Controlling and achieving unique properties via matrix modifications and addition of various specific nanofillers seems be one of the key elements to success. The purpose of this work is to briefly present some examples of graphene nanoderivatives, their syntheses, properties and influence on...
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FURTHER REMARKS ON THE SURFACE VIS IMPRESSA CAUSED BY A FLUID-SOLID CONTACT
PublicationIt is well-known that, nano-mechanics should take into account not only physical phenomena occuring within the bulk but, first of all, the physical phenomena appropriate for a surface of two materials contact. The huge volume density of internal surfaces as well countours lines located within the nanomaterial results in our interest in, apart from classical form of mass, momentum and entropy transport, those modes of transportation...
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THE MODELLING OF ACCUMULATION AND DISSIPATION OF ENERGY IN MECHANICAL DRIVE SYSTEM
PublicationThis paper presents a modelling of accumulation and dissipation energy in simple drive system. The simple drive system is presented by laboratory stand designed for calculate fatigue life of material for bending and rotation tests pieces. The laboratory stand was prepared to diagnosis of fatigue life of material by use energetic methods. This idea was submitted as utility model to Polish Patent Office. This laboratory stand gives...
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Localized impedance measurements of AA2024 and AA2024-T3 performed by means of AFM in contact mode
PublicationPurpose: The purpose of this paper is to present the results of an atomic force microscopy (AFM) based approach to local impedance spectroscopy (LIS) measurement performed on AA2024 and AA2024-T3 aluminium alloys. Design/methodology/approach: AFM-LIS measurements were performed ex-situ without the electrolyte environment, so in fact the electrical not electrochemical impedance was obtained. Findings: Relative local impedance values...
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Multi-Agent Signal Filtering for Electrical Energy Demand Management
PublicationConsumers participating in electrical energy Demand Response (DR) programs may be exposed to energy-use related decisions at instants of time which are generally hard to predict. This is especially cumbersome to residential consumers who are less capable of investing in special equipment, or devoting significant time to analyze information and take decisions. To ease residential consumer participation, a multi-agent system proposed...
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Assessment of under power ed propulsion machinery in electrically driven small inland waterway passenger ships from classification society point of view
PublicationPaper presents short operat ional a nd engineering analysis of underpowered propulsion in small electrically propelled small inland passenger ships. There is evidence that in certain weather conditions the phenomena of added aerodynamic resistance of small water crafts may have seriou s influence on their speed and manoeuvrability. Existing regulations like class societies rules for ship classification and construction or EU Directive 2006/87/EC do...
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ASSESSMENT OF UNDERPOWER ED PROPULSION MACHINERY IN ELECTRICALLY DRIVEN SMALL INLAND WATERWAY PASSENGER SHIPS FROM CLASSIFICATION SOCIETY POINT OF View
PublicationPaper presents short operat ional a nd engineering analysis of underpowered propulsion in small electrically propelled small inland passenger ships. There is evidence that in certain weather conditions the phenomena of added aerodynamic resistance of small water crafts may have serious influence on their speed and manoeuvrability. Existing regulations like class societies rules for ship classification and construction or EU Directive 2006/87/EC do...
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Performance Evaluation of a 650V E-HEMT GaN Power Switch
PublicationGaN power switches have better characteristics compared to the state-of-the-art Si power transistors. These devices offer high operating temperature and current densities, fast switching and low on-resistance. However, currently only a few producers offer technology of high voltage GaN transistors. Immaturity of this technology is the reason why experimental evaluation of GaN parameters must be performed to properly exploit their...
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Determining and verifying the safety integrity level of the controland protection systems under uncertainty
PublicationThe probabilistic models of the electrical, electronic and programmable electronic (E/E/PE)systems, which are proposed in the IEC 61508 and IEC 61511 standards, do not cover the uncertainty aspectsof results obtained from these models. The proposed method takes into consideration the sensitivity analysisof probabilistic models of E/E/PE systems as well as the uncertainty of probabilistic results. It uses differentialfactors, which...