Search results for: ELECTRIC DEVICES
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Photoconduction and magnetic field effect on photoconduction in hole-transporting star-burst amine (m-MTDATA) films
PublicationPhotoconduction and magnetic field effect on photoconduction have been investigated as a function of electric field strength, excitation light intensity and wavelength in vacuum evaporated films of m-MTDATA (4,4′,4″-tris(N-(3-methylphenyl)-N-phenylylamino) triphenylamine), the starburst amine commonly used as hole-transporting material in organic light-emitting diodes. The photocurrent is found to be generated by the singlet exciton...
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Yields and Time-of-Flight Spectra of Neutral High-Rydberg Fragments at the K Edges of the CO2 Molecule
PublicationWe have studied the production of neutral fragments in high-Rydberg (HR) states at the C 1s and O 1s edges of the CO2 molecule by performing two kinds of experiments. First, the yields of neutral HR fragments were measured indirectly by ionizing such fragments in a static electric field and by collecting resulting singly charged positive ions as a function of the photon energy. Such measurements reveal not only excitations below...
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Mathematical modelling of the overhead contact line for the purpose of diagnostics of pantographs
PublicationThe overhead contact line (OCL) is the most effective way for supplying railway electric vehicles. The increase of the speed of the vehicles increases power consumption and requires ensuring proper cooperation of pantographs with OCL. The paper describes the novel mathematical model of the OCL system and the simulation results. The primary objective is a more accurate analysis to increase the reliability of the evaluation of monitoring...
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Strategies for Achieving Energy Neutrality in Biological Nutrient Removal Systems – a Case Study of the Slupsk WWTP (northern Poland)
PublicationThe paper presents a model-based evaluation of technological upgrades on the energy and cost balance in a large biological nutrient removal wastewater treatment plant (WWTP) in the city of Slupsk (northern Poland). The proposed upgrades include chemically enhanced primary sludge removal and reduction of the nitrogen load in the deammonification process employed for reject water treatment. Simulations enabled to estimate the increased...
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Mixed ionic-electronic conductivity and structural properties of strontium-borate glass containing nanocrystallites of Bi2 VO5.5
PublicationSamples of strontium borate glass containing bismuth vanadate nanocrystallites were prepared. Nanocomposites containing up to 45mol% of the Bi2VO5.5 phase exhibit electrical properties closer to the strontium-borate glass than to the ferroelectric Bi2VO5.5 ceramic. The glass matrix still may contain some part of bismuth and vanadium ions even after crystallization process and there is too little of crystalline phase to observe...
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Energy recovery effectiveness in trolleybus transport
PublicationNowadays the issue of electric energy saving in public transport is becoming a key area of interest whichis connected both with a growth in environmental awareness of the society and an increase in the pricesof fuel and electricity. One of the possibilities to reduce energy consumption in urban public transport isto increase the extent of regenerative braking energy utilization. This can be achieved by its accumulationin the supercapacitors...
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Strategies for achieving energy neutrality in biological nutrient removal systems - a case study of the Slupsk WWTP (northern Poland)
PublicationThe paper presents a model-based evaluation of technological upgrades on the energy and cost balance in a large biological nutrient removal wastewater treatment plant (WWTP) in the city of Slupsk (northern Poland). The proposed upgrades include chemically enhanced primary sludge removal and reduction of the nitrogen load in the deammonification process employed for reject water treatment. Simulations enabled to estimate the increased...
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Vibro-Electrical Behavior of a Viscoelastic Piezo-Nanowire in an Elastic Substrate Considering Stress Nonlocality and Microstructural Size-Dependent Effects
PublicationThis research deals with dynamics response of a Pol/BaTiO3 nanowire including viscosity influences. The wire is also impressed by a longitudinal electric field. Hamilton's principle and Lagrangian strains are employed in conjunction with a refined higher-order beam theory in order to derive equations of motion. By combining nonlocality and small size...
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Functional Safety Analysis including Human Factors
PublicationIn this paper selected aspects of human factors are discussed that should be taken into account during the design of safety-related functions for a complex hazardous installation and its protections. The layer of protection analysis (LOPA) methodology is used for simplified risk analysis based on defined accident scenarios. To control the risk the safety instrumented functions (SIFs) are identified and their safety integrity levels...
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Modeling and Evaluation of Electric Treeing Phenomena in Polymeric Cable Insulation
PublicationThis paper investigates the treeing phenomenon in polymeric materials such as crosslinked polyethylene (XLPE) that is widely used in medium and high voltage power cables as primary insulation. The modeling of electrical tree growth in the insulation from its initiation to breakdown is significant research work that illustrates the discharge dynamics and its impact on aging process in polymeric insulation. This study utilizes pulse...
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Chestnut-Derived Activated Carbon as a Prospective Material for Energy Storage
PublicationIn this work, we present the preparation and characterization of biomass-derived activatedcarbon (AC) in view of its application as electrode material for electrochemical capacitors. Porouscarbons are prepared by pyrolysis of chestnut seeds and subsequent activation of the obtainedbiochar. We investigate here two activation methods, namely, physical by CO2and chemical usingKOH. Morphology, structure and specific surface area (SSA)...
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Hybrid energy storage forelectric multiple units to operate at the partially electrified line Gdynia -Hel
PublicationThe article presents calculations enabling the selection of an on-board energy storage device to replace diesel-powered trains with modern storage multiple units on the example railway line Gdynia Główna -Hel. The pioneering and currently used storage electric multiple units, mainly in Europe, were presented. The condensed results of the inventory of the line in question, including the technical condition...
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Optimization of using recuperative braking energy on a double-track railway line
PublicationIn the introduction, possible ways of reusing energy from recuperation are presented. Next, the paper investigates the possibility of using regenerative braking in the range allowed by the detailed timetable by adopting the method of transferring the recovered electric energy directly to the catenary and immediate use of this energy by another train at the same power section. In the main part of the work, it is shown, that the...
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X-Ray Diffraction, Mössbauer Spectroscopy and Magnetoelectric Effect Studies of Multiferroic Bi5Ti3FeO15 Ceramics
PublicationBi5Ti3FeO15 ceramics belongs to multiferroic class of materials. In this work it was prepared by solid-state sintering method and investigated by X-ray diffraction, Mössbauer spectroscopy, and magnetoelectric effect measurements. As it was proved by X-ray diffraction studies the single-phase Bi5Ti3FeO15 compound was obtained. The Mössbauer investigations revealed paramagnetic character of the compound at room temperature as well...
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Electrochemical behavior of a composite material containing 3D-structured diatom biosilica
Publication3D-structured diatom biosilica mixed with conducting carbon black was investigated as an active electrode material for lithium-ion batteries. Diatom biosilica was obtained by cultivation of the selected diatom species under laboratory conditions. Several instrumental techniques (XRD, FTIR, Raman, SEM-EDX, TGA) were used to characterize the physicochemical properties of applied biosilica. It was evidenced that the prepared new composite...
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Ultrasonic spectroscopy of silicon single crystal
PublicationSpecimens of Si single crystals with different crystal orientation [100] and [110] were studied by the electro-ultrasonic spectroscopy (EUS) and Resonant Ultrasonic Spectroscopy (RUS). A silicon single crystal is an anisotropic crystal, so its properties are different in different directions in the material relative to the crystal orientation. EUS is based on interaction of two signals: electric AC signal and ultrasonic signal,...
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Exfoliated graphite with spinel oxide as an effective hybrid electrocatalyst for water splitting
PublicationThe aim of the conducted research was to develop hybrid nanostructures formed from MnCo2O4 and exfoliated graphite. Carbon added during the synthesis allowed for obtaining a well-distributed MnCo2O4 particle size with exposed active sites contributing to the increased electric conductivity. The influence of the weight ratios of carbon to a catalyst for hydrogen and oxygen evolution reactions was investigated. The new bifunctional...
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Mirosław Włas dr inż.
PeopleWykształcenie : 1987-1991 – Liceum Ogólnokształcące im. Jana Bażyńskiego w Ostródzie – profil matematyczno-fizyczny 1991-1996 Politechnika Gdańska – studia na Wydziale Elektrycznym 1997-2002 Politechnika Gdańska – studia doktoranckie na Wydziale Elektrotechniki i Automatyki 1998- 1999 Politechnika Gdańska – kurs ekonomii na Wydziale Zarządzania i Ekonomii PG 1997-2000 – kurs j. angielskiego - Zespół Lektorów BEST – Gdańsk 2003...
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AN ENERGY APPROACH TO THE FATIGUE LIFE OF SHIP PROPULSION SYSTEMS
PublicationThe conducted research investigations aimed to carry out an identification of the constructional materials fatigue state of the ship propulsions’ rotational mechanical units for diagnostic purposes. The fatigue cracks of the elements transmitting mechanical energy streams from the propulsion engines to the ship propellers or to the generators of the ship’s electric power station stand for a primary reason for the secondary, usually...
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Modelling and analysis of a synchronous generator in more electric aircraft power system using Synopsys/Saber simulator = Modelowanie i analiza generatora synchronicznego w systemie elektroenergetycznym nowoczesnego samolotu. Zastosowanie symulatora Synopsys/Saber
PublicationStreszczenie angielskie: A model for studying synchronous machine (SM) dynamic behaviour in more electric aircraft (MEA) power system is developed and implemented in the Synopys/Saber simulation environment. The modelling language MAST has been used to elaborate the SM model. The elaborated model exhibit a network with the same number of external terminals/ports as the real SM, and represents its behaviour in terms of the electrical...
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Broken Rotor Symptons in the Sensorless Control of Induction Machine
PublicationInverter fed sensorless controlled variable speed drives with induction machine are widely used in the industry applications, also in wind power generation and electric vehicles. On-line self diagnostic systems implementation is needed for early stage fault detection and avoiding a critical fault. Diagnostic algorithms in modern DSP-based controllers can operate simultaneously with control system functions. In the closed-loop controlled...
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Survey on opportunities and barriers in lighting controls
PublicationThis report summarizes a survey performed in eight countries on the status quo of daylight and electric lighting control systems. Feedback from more than 100 international experts (building / facility managers and planers) was evaluated. The aim of the survey was to identify the perception of the different possibilities of the current lighting control solutions and the expectations about the control systems. The survey aims to...
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Safety issues referred to induced sheath voltages in high-voltage power cables – case study
PublicationLoad currents and short-circuit currents in high-voltage power cable lines are sources of the induced voltages in the power cables’ concentric metallic sheaths. When power cables operate with single-point bonding, which is the simplest bonding arrangement, these induced voltages may introduce an electric shock hazard or may lead to damage of the cables’ outer non-metallic sheaths at the unearthed end of the power cable line. To...
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Energy efficiency of electric multiple units in suburban operation
PublicationThis thesis presents approach to analysis of energy efficiency of a suburban rail network, using novel models developed on the Matlab/Simulink basis. Necessary features and requirements for such models were determined thru in-depth review of the source literature in all applicable fields: electrified transportation systems, electric multiple units construction, vehicle drivetrains and finally, existing simulation methods. Existing...
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Computer-Aided Calculations of Earth Potential Rise in High Voltage Overhead Lines
PublicationHigh voltage overhead power lines with earth wires comprise towers made of conductive material. Some towers are in locations where people can be expected to be either for a long time or for a short time but very frequently. Evaluation of shock hazard near such towers requires calculation of line-to-earth short-circuit current, earth current and especially earth potential rise. Number of towers in high voltage power lines can exceed...
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Security Information Sharing for the Polish Power System
PublicationThe Polish Power System is becoming increasingly more dependent on Information and Communication Technologies which results in its exposure to cyberattacks, including the evolved and highly sophisticated threats such as Advanced Persistent Threats or Distributed Denial of Service attacks. The most exposed components are SCADA systems in substations and Distributed Control Systems in power plants. When addressing this situation...
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Reduction of Tire Rolling Resistance by Optimization of Road Surfaces and Tires
PublicationDuring interaction between tire and road surface three very important phenomena are always in effect. One of them (very desirable) is friction that is important for traction, braking and cornering. Two other phenomena are not desirable at all, that is rolling resistance and noise. This paper discusses relations between road surface and tire parameters versus tire rolling resistance. Road surface texture, porosity, impedance, strength...
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Problems in designing and operating the functional safety solutions of higher integriity levels
PublicationThe aim of this article is to identify and discuss some problems that have been encountered in designing and operating the functional safety solutions of higher safety integrity levels (SIL 3 and SIL 4) in the light of analyses outlined in a new version of the international standard IEC 61508:2010. Examples of such solutions are the electric / electronic / programmable electronic systems (E/E/PESs) and the safety instrumented systems...
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Application of the Mathar method to identify internal stress variation in steel as a welding process result
PublicationThe paper deals with the method to identify internal stresses in two-dimensional steel members. Steel members were investigated in the delivery stage and after assembly, by means of electric-arc welding. In order to perform the member assessment two methods to identify the stress variation were applied. The first is a non-destructive measurement method employing local external magnetic field and to detecting the induced voltage,...
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Towards systemic functional safety and security management in hazardous plants
PublicationThe aim of this article is to identify and discuss some issues related to functional safety and security management in hazardous industrial plants. The safety functions are to be realised using the electric / electronic / programmable electronic systems (E/E/PESs) or the safety instrumented systems (SISs) that are designed and operated respectively according to IEC 61508 and IEC 61511 requirements in life cycle. Although the role...
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Local properties of organic coatings close to glass transition temperature
PublicationAcrylic coating applied on copper substrate has been investigated at different temperatures starting from the ambient one up to the level above the glass transition temperature. Its local topographic and electric properties have been examined with the atomic force microscopy (AFM) based approach including dc current mapping and local impedance spectroscopy. The local findings have been compared with the information from global...
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Analytical modeling of electric drives for vehicle traction control systems
PublicationWheel-torque control bandwidth in vehicle dynamics model is crucial in evaluating optimal tracking ability of tire slip and in analysis of control system stability. Electric drives’ control dynamics are influenced by timing of digital control events, e.g. by sampling instant of motor currents. Reflecting this timing in drive analytical models is therefore important for analysis of vehicle traction systems. The paper considers five...
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Angle Tracking Observer for Filtering Rotor Position Estimates in Sensorless Electric Drives
PublicationSensorless electric drives use measurements of electrical quantities to estimate rotor position and speed. Measurement errors deteriorate the estimation accuracy, thus additional means are necessary to remove high-frequency components from estimated signals. This paper proposes to use an Angle Tracking Observer (ATO) for reducing noise in rotor position estimates, which is related to random errors in the measurements. A simplified,...
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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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Safety Integrity Verification Issues of the Control Systems for Industrial Process Plants
PublicationThe aim of this article is to identify and discuss some issues that can be encountered in designing the industrial automation and control systems (IACS) for implementing safety functions. In a functional safety standard IEC 61511 for the process industry such systems are named the basic process control systems (BPCS) and the safety instrumented systems (SIS). In a generic functional safety standard IEC 61508 they are depicted as...
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Takagi-Sugeno Fuzzy Model of Dissolved Oxygen Concentration Dynamics in a Bioreactor at WWTP
PublicationThe importance of dissolved oxygen concentration controlinaerationtanksofabioreactoratflow-throughwastewater treatment plant (WWTP) can easily be justified by technological requirements as well as simple economics. Firstly, appropriate levels of dissolved oxygen concentration are essential for the vitality of microorganisms that comprise the bioreactor. Secondly, the costs of dissolved oxygen concentration control related to the...
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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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Multi-objective optimization of the ORC axial turbine for a waste heat recovery system working in two modes: cogeneration and condensation
PublicationDue to the demand of the district heating network and electric power grid ORC turbines can operate in the condensation and cogeneration modes. This approach requires the design of an expander which is characterized by high efficiency in each mode of operation. The paper is devoted to a multi-objective efficiency optimization of a one stage axial ORC turbine working on MM (Hexamethyldisiloxane). An Implicit Filtering algorithm (IF)...
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Polysaccharide-based electroconductive hydrogels: Structure, properties and biomedical applications
PublicationArchitecting an appropriate platform for biomedical applications requires setting a balance between simplicity and complexity. Polysaccharides (PSAs) play essential roles in our life in food resources, structural materials, and energy storage capacitors. Moreover, the diversity and abundance of PSAs have made them an indispensable part of food ingredients and cosmetics. PSA-based hydrogels have been extensively reviewed in biomedical...
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Comparative Study of Integer and Non-Integer Order Models of Synchronous Generator
PublicationThis article presents a comparison between integer and non-integer order modelling of a synchronous generator, in the frequency domain as well as in the time domain. The classical integer order model was compared to one containing half -order systems. The half-order systems are represented in a Park d-q axis equivalent circuit as impedances modelled by half-order transmittances. Using a direct method based on the approximation...
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Onboard Energy Storage and Power Management Systems forAll-Electric Cargo Vessel Concept
PublicationThis paper presents an innovative approach to the design of a forthcoming, fully electric-powered cargo vessel. This work begins by defining problems that need to be solved when designingvessels of this kind. Using available literature and market research, a solution for the design of apower management system and a battery management system for a cargo vessel of up to 1504 TEUcapacity was developed. The proposed solution contains...
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Influence of Sn and Pb Ions Substitutions on Dielectric Properties of Barium Titanate
PublicationThe 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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HISTORIA ROZWOJU LAMP I OPRAW OŚWIETLENIOWYCH SŁUŻĄCYCH DO OŚWIETLANIA WNĘTRZ MIESZKALNYCH. CZĘŚĆ PIERWSZA
PublicationThis paper reflects on the history of decorative luminaire design. The development of the new sources of light within residential environment has been changing the luminaire design. Residential dwellings have been lit by a lot of light sources through the centuries form a point lamps like candle or incandescent lamps to linear florescent lamps and LED strips. A development of SSL technology introduced an idea of lit surfaces. Energy...
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Effect of pine impregnation and feed speed on sound level and cutting power in wood sawing
PublicationThe sound levels along with the cutting power registered during the sawing process of the impregnated and non-impregnated pine wood at two feed speeds are shown and compared in this paper. Statistically significant differences in the acoustic signals occurred at the lower feed rate. The differences became smaller with an increase in the feed speed. In contrast to the sound signal, the differences...
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Models of Brushless Synchronous Generator for Studying Autonomous Electrical Power System
PublicationThis is a PhD dissertation. The work presented in this monograph was carried out at the Department of Power Electronics and Electrical Machines, Faculty of Electrical and Control Engineering at the Gdansk University of Technology. Developed during the research models of brushless synchronous generator ware verified using FEM based simulations and measurements conducted on the prototype generator. The main focus of the research...
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Modular power converter with superconducting magnetic energy storage for electric power distribution system — Analysis and simulation
PublicationThis paper describes selected issues concerning realization of energy storage system (ESS) designed to operate in power distribution system. This paper presents a modular approach of 300 kVA power converter operating with superconducting magnetic energy storage (SMES), which gives high dynamics together with high power and suitable capability for instantaneous energy storage. Analysis and simulation studies of selected power converter...
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SMART GRID TECHNOLOGIES IN ELECTRIC POWER SUPPLY SYSTEMS OF PUBLIC TRANSPORT
PublicationNowadays the issue of electric energy saving in public transport is becoming a key area of interest which is connected both with a growth in environmental awareness of the society and an increase in the prices of fuel and electricity. It can be achieved by improving the usage of regenerative breaking. In 2016 the Przedsiębiorstwo Komunikacji Trolejbusowej (PKT, Trolleybus Transport Company) in Gdynia began practical implementation...
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High Efficiency Dual-Active-Bridge Converter with Triple-Phase-Shift Control for Battery Charger of Electric Vehicles
PublicationAn optimal modulation scheme with triple-phase-shift (TPS) control could increase the efficiency in the entire load range for a dual-active-bridge (DAB) converter under wide output voltage range conditions. Therefore, this study proposes a convergent approach to TPS mode selection, coupled with an optimal modulation scheme, ensuring the circuit’s efficiency over the entire range in the realm of a high-power and high-efficiency...
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Electromodulation and magnetomodulation of exciton dissociation in electron donor (starburst amine) : electron acceptor (bathocuproine) system
PublicationElectric field dependencies of electromodulated photoluminescence and photocurrents as well as the magnetic field effects on photocurrents, photovoltaic characteristics, electromodulated photoluminescence and photoluminescence have been investigated in vacuum evaporated films of m-MTDATA:BCP (4,4',4''-tris(N-(3-methylphenyl)-N-phenylamino)triphenylamine and bathocuproine) system. The electromodulation processes do remain in accordance...
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Experimental bases for the rail track surface damage detection system
PublicationA diagnosis of rail surface is generally based on the classical method of direct assessment and track geometry measurements. Identification and qualification of inequality and damage on the surface rails is depend on the skills and experience person who conducting inspection. In times of increasing exploitation of railways, infrastructure managers decide to use systems supporting the assessment of technical condition of the railways....