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Search results for: LIMIT OF POWER CONVERSION EFFICIENCY, ENERGY BAND GAP, INDOOR PHOTOVOLTAICS, PHOSPHOR-BASED LED BULB
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Determination of equivalent axle load factors with the use of strain energy of distortion
PublicationThe paper proposes a new method for calculation of equivalent axle load factors based on the analysis of strain energy of distortion induced in road pavements by traffic loads. The main advantage of the method is the more accurate calculation of the effects of multiple axles and super single versus dual tyres. The methodconsiders the location of critical points, at which strain energy of distortion reaches extreme values. When...
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Microgrid Energy Management System
PublicationIn the era of rapid development of "green energy” and storage devices, microgrids implemented in line with the concept of distributed generation can be an effective form of power management. There is a need for an efficient, optimal and reliable control of the combined infrastructure. The article presents a flexible, configurable microgrid's resources control system, which executes the task of meeting the electricity demand of...
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Multi-Option Model of Railway Traffic Organization Including the Energy Recuperation
PublicationThe article presents the issue of organization of railway traffic within the station, taking into account energy recuperation. We identified a number of factors which affect the energy efficiency of recuperation, including the issue of transfer of energy technology between a few vehicles. We presented some aspects of the decision problem of graphic train timetable construction with regard to recuperation. As an indicator of quality...
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Exploring efficiency differentials between Italian and Polish universities, 2001-2011
PublicationIn this study, data envelopment analysis (DEA) is used to evaluate the relative efficiency of a sample of 54 Italian and 30 Polish state universities over the period 2001–11. The investigation was conducted in two steps. Unbiased DEA efficiency scores were first estimated and then regressed on external variables to quantitatively assess the direction and size of the impact of potential determinants. The analysis reveals a strong...
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Gas Turbine Cycle with External Combustion Chamber for Prosumer and Distributed Energy Systems
PublicationThe use of various biofuels, usually of relatively small Lower Heating Value (LHV), affects the gas turbine efficiency. The present paper shows that applying the proposed air by-pass system of the combustor at the turbine exit causes tan increase of efficiency of the turbine cycle increased by a few points. This solution appears very promising also in combined gas/steam turbine power plants. The comparison of a turbine set operating...
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Operation of the 900 MW power plant with the ORC supplied from three heat sources
PublicationThe chapter is aimed at utilisation of waste heat in the reference supercritical power plant in the manner to produce electricity in ORC installation. The waste heat is available in the form of a stream of hot water at 90°C, recovered from the exhaust gases in the amount of 200MW. Such low enthalpy heat source is rather insufficient to produce a good quality vapour to feed the ORC turbine. Therefore an original approach to increase...
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Possible efficiency increasing of ship propulsion and marine power plant with the system combined of marine diesel engine, gas turbine and steam turbine
PublicationW rozdziale przedstawiono koncepcję układu kombinowanego okrętowego lub morskiej pływającej elektrowni dużej mocy złożonego z silnika głównego tłokowego oraz skojarzonych z nim turbiny gazowej mocy i układu turbiny parowej, wykorzystujących energię zawartą w spalinach wylotowych silnika głównego tłokowego. Rozpatrywano możliwości zastosowania takich układów w układach okrętowych z punktu widzenia sprawnościowego. Podano możliwości...
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Methods for evaluating rated power of diesel-powered generator set
PublicationBasic concepts for evaluating rated power of generator sets powered by combustion engines are presented in this article. A relation between parameters of the engine and the generator are shown. Recommendations contained in the standards and technical literature are systematized. The scheme and methodology for evaluating rated power of the generator set, based on laboratory research, are suggested. Also, the main problems which...
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The paradigms of power in the Russian Federation
PublicationThis article outlines the position of the Russian Federation in the first decade of the 21th century, seen in its political, economic and military aspects. It attempts to document the fact that Russia, the former world superpower, has turned into a regional power.
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EFFICIENCY OF HEALTHCARE SYSTEMS IN EUROPEAN COUNTRIES - THE DEA NETWORK APPROACH
PublicationHealthcare systems in Europe are constantly undergoing reforms which adapt them to social, economic and political requirements. The aim of this article is to examine the efficiency of healthcare systems in 30 European countries in 2014. The Network Data Envelopment Analysis (NDEA) model was used. The efficiency of the countries’ overall health systems and their two main components were examined: the public health system and the...
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Induction Motor Multiscalar Model Based Sensorless Control Using Power Measurement
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Design Considerations of GaN Transistor Based Capacitive Wireless Power Transfer System
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Improving the performance of the 3-dB microstrip hybrid-ring based power dividers
PublicationW pracy przedstawiono wyniki teoretycznych i eksperymentalnych badań zintegrowanych układów mikropaskowych 3-dB dzielników mocy wykorzystującch strukturę pierścieniową. Zaproponowano modyfikację geometrii układu prowadzącą do poprawy jego charakterystyk transmisyjnych.
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Switched-capacitor DC-DC converters in arbitrary switching mode - topologically derived resistive models based on incremental graph approach.
PublicationIn the preceding paper we reviewed some of modeling approaches aimed at systematic formulation and solution of switched capacitor DC-DC converters. In our review, special attention was paid to computationally efficient and mathematically elegant methods. In so doing we had tried to demonstrate the virtues of unified Incremental Graph (IG) approach. Incremental Graph is, in concept, a tool originally created for analysis and synthesis...
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Dynamic model of nuclear power plant turbine
PublicationThe paper presents the dynamic multivariable model of Nuclear Power Plant steam turbine. Nature of the processes occurring in a steam turbine causes a task of modeling it very difficult, especially when this model is intended to be used for on-line optimal process control (model based) over wide range of operating conditions caused by changing power demand. Particular property of developed model is that it enables calculations...
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[ILiT, IŚGiE] Reliability-Based Optimization (RBO) - 2022/23
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[ILiT, IŚGiE] Reliability-Based Optimization (RBO) - 2023/24
e-Learning Courses -
Virtual inertia in Electric Power System
PublicationThe article presents the idea of introducing virtual inertia system to the electric power systems. The virtual inertia aim is to reduce or eliminate the effect of reducing the inertia of the power system as a result of replacing classic electricity generating units with renewable renergy sources (RES). The considerations are ilustrated by a computational example.
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Efficiency of European public higher education institutions: a two-stage multicountry approach
PublicationThe purpose of this study is to examine efficiency and its determinants in a set of higher education institutions (HEIs) from several European countries by means of non-parametric frontier techniques. Our analysis is based on a sample of 259 public HEIs from 7 European countries across the time period of 2001-2005. We conduct a two-stage DEA analysis (Simar and Wilson in J Economet 136:31-64, 2007), first evaluating DEA scores...
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POWER ENGINEER
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Power and Education
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THE INFLUENCE OF PHASE SHIFTERS ON THE VOLTAGE STABILITY OF CONNECTED POWER SYSTEMS
PublicationThe paper presents the results of simulation tests of connected power systems in which phase shifters were installed on cross-border links. The analysis was carried out in terms of assessing the impact of shifters on node voltage stability. Individual systems were characterized by different balance of active power: deficit or excess. The evaluation of voltage stability was based on the dU/dQ and dU/dP criteria.
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Optimal Multivariable Control for Modified Z-source Based IPT
PublicationThis paper describes Z-source based inductive power transfer topologies control approaches. The goal of this work is a multi-variable control approach which involves a constant voltage/constant current control along with an optimal frequency control to obtain maximum efficiency. This control is applied to the wireless power transfer system based on a modified Z-source topology. The description of the control method along with simulation...
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The efficiency and reliability of pollutant removal in a hybrid constructed wetland with giant miscanthus and Jerusalem artichoke in Poland
PublicationIn this paper, we analysed the pollutant removal efficiency and reliability of a vertical and horizontal flow hybrid constructed wetland (CW) planted with giant miscanthus and Jerusalem artichoke. The wastewater treatment plant, located in south-eastern Poland, treated domestic sewage at an average flow rate of 1.2m3·d−1. The tests were carried out during. 5-years of operation of the sewage treatment plant (2011–2016). During this...
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Mathematical modelling of gasification process of sewage sludge in reactor of negative CO2 emission power plant
PublicationSewage sludge is a residue of wastewater processing that is biologically active and consists of water,organic matter, including dead and alive pathogens, as well as organic and inorganic contaminants suchas polycyclic aromatic hydrocarbons (PAHs) and heavy metals. Due to the nature of sewage sludge and itspossible influence on human health and wellbeing, it is a subject of various regulations. Currently,sewage sludge is considered...
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Research of Emergency Modes of Wind Power Plants Using Computer Simulation
PublicationThe aim of this study is to investigate changes in the wind power plant energy production parameters under the conditions of sudden wind changes and voltage drop. To achieve these goals, a simulation of operation of wind power plants was performed. Twelve wind turbines with variable rotational speed equipped with a Fuhrländer FL 2500/104 asynchronous double-fed induction generator (DFIG) were used, each with an installed capacity...
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Automatic tuning of a resonant circuit in wireless power supply systems for biomedical sensors
PublicationIn this paper, a tuning method of a resonant circuit suited for wireless powering of miniature endoscopic capsules is presented and discussed. The method allows for an automatic tuning of the resonant frequency and matching impedance of a full wave rectifier loading the resonant circuit. Thereby, the receiver tunes so as to obtain the highest power efficiency under given conditions of transmission. A prototype receiver for wireless...
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Measurements of the fundamental harmonic frequency of voltages on main bars in a ship power station
Open Research DataThe presented dataset is part of research focusing on the assessment of metrological properties of the instrument, Estimator/Analyzer (E/A v.2), developed and made at the Faculty of Electrical Engineering, Department of Marine Electrical Power Engineering of Gdynia Maritime University. The attached dataset contains processed data, expressing the fundamental...
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Assessment, optimisation and working fluid comparison of organic rankine cycle combined with negative CO2 gas power plant system
PublicationThis study aims to investigate the application of the Organic Rankine Cycle (ORC) as an alternative to low-pressure expansion in the negative CO2 power plant (nCO2PP). The reason for this study is that a detailed analysis of nCO2PP indicates a certain amount of waste heat present in the exhaust gas from the high-to-intermediate pressure gas turbine. Some of this energy can be used by the application of the expansion in a low-pressure...
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Modeling energy consumption of parallel applications
PublicationThe paper presents modeling and simulation of energy consumption of two types of parallel applications: geometric Single Program Multiple Data (SPMD) and divide-and-conquer (DAC). Simulation is performed in a new MERPSYS environment. Model of an application uses the Java language with extension representing message exchange between processes working in parallel. Simulation is performed by running threads representing distinct process...
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Analiza danych biznesowych z wykorzystaniem MS Excel – Power BI i Power Query
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Graphical presentation of the power of energy losses and power developed in the elements of hydrostatic drive and control system. Part I. Rotational hydraulic motor speed series throttling control systems
PublicationZaproponowano i uzasadniono wykres przedstawiający kierunek wzrostu strumienia mocy narastającej od wału lub tłoczyska silnika hydraulicznego do wału pomopy, mocy narastającej w wyniku wymuszania przez moce strat energetycznych występujących w elementach układu i sterowania hydrostatycznego. Przedstawiono interpretację graficzną mocy strat energetycznych występujących w elementach układów, a także mocy rozwijanych przez te elementy....
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PARAMETRIC ANALYSIS OF THE EFFICIENCY OF THE COMBINED GAS-STEAM TURBINE UNIT OF A HYBRID CYCLE FOR THE FPSO VESSEL
PublicationA thermal diagram of the combined gas‒steam turbine unit of a hybrid cycle, which is an energy complex consisting of a base gas turbine engine with a steam turbine heat recovery circuit and a steam-injected gas turbine operating with overexpansion, is proposed. A mathematical model of a power plant has been developed, taking into consideration the features of thermodynamic processes of simple, binary, and steam-injected...
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Urban dew formation efficiency and chemistry in Poland
PublicationThe measurements of dew formation efficiency and chemistry were performed in Poland in September 2009, as a part of a longer, two-year sampling campaign. Pairs of sites, representing centers of major Polish cities and rural conditions in three different regions, were compared. With the aim to get more detailed landuse-oriented characteristics of dew, two additional sites were set close to Wroclaw. Collection of dew at each site...
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An Off-Body Narrowband and Ultra-Wide Band Channel Model for Body Area Networks in a Ferryboat Environment
PublicationIn the article an off-body narrowband and ultra-wide band channel model for body area networks in a ferryboat environment is described. Considering the limited number of publications there is a need to develop an off-body channel model, which will facilitate the design of radio links, both from the multimedia services provider and the security point of view, for body area networks in this atypical environment. A mobile heterogeneous...
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Influence of YARN Schedulers on Power Consumption and Processing Time for Various Big Data Benchmarks
PublicationClimate change caused by human activities can influence the lives of everybody onthe planet. The environmental concerns must be taken into consideration by all fields of studyincludingICT. Green Computing aims to reduce negative effects of IT on the environment while,at the same time, maintaining all of the possible benefits it provides. Several Big Data platformslike Apache Spark orYARNhave become widely used in analytics and...
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The Energy Potential of the Lower Vistula River in the Context of the Adaptation of Polish Inland Waterways to the Standards of Routes of International Importance
PublicationBased on new policies of the European Union, green technologies are to be mostly considered for power generation. Hydropower generation is one of the essential elements of sustainable energy production. Therefore, specific attention, both economically and technically, needs to be given to this sector of energy production. The Vistula River in Poland is considered an international waterway. The power production potential of the...
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Methodology for determining the elemental composition, as well as energy and ignition properties of the low-sulfur marine fuels
PublicationThe key metrological issue of substance and energy balance in research engines is the precise determination of the elemental composition of the applied fuel and its net calorific value. This makes it possible to calculate the amount of heat brought with the fuel into the combustion chamber, as well as the amount and gas composition of the exhaust. However, to fully assess the energy quality of the fuel used, its ignition properties...
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Estimation, optimization and analysis based investigation of the energy consumption in machinability of ceramic-based metal matrix composite materials
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Experimental ORC micro-power plant for CHP application Part A: power plant arrangement
PublicationThe co-generative micro-power plant with the HFE7100 applied as a working medium was designed and built for experimental investigations. The heat output of the plant was assumed equal to 20 kW, while the electric output amounted to about 3kW. Examples of the results of the preliminary experimental research on a boiler, heat exchangers, a pump and a turbine-generator set are presented and analysed.
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Evaluation of time-efficiency of disjoint paths calculation schemes
PublicationThe concept of alternate paths has been shown in the literature to provide fast response of a network to failures of its elements (nodes/links) affecting flows along the primary communication paths. Various approaches have been proposed to reduce the time necessary to redirect the respective flows onto the alternate paths. In this paper, we focus on another important objective, that so far has not received much attention, i.e.,...
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Interdependence between Power Grids and Communication Networks: A Resilience Perspective
PublicationPower network resilience is increasingly dependent on communication networks. Besides traditional generation, power networks need to accommodate increasingly high penetration levels of dispersed micro generation, mostly based on renewable sources, and increasing and challenging demand, such as electric vehicles. At the same time the deployment of enabling technologies throughout the power grid makes available new demand resources...
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A filter bank solution for active power filter control algorithms
PublicationThb paper describes the proposed active power fiIter (APF) with a new control circuit based on an algorithm using ufilter bank and a harmonic predictor. The conirol circuit was realized using the digiiaI signor processor ADSP-21065L and FPGA circuiL In the proposed circuit transient performunee of APF is improved The active power fdter circuil has been built and teste6 and some illustrative, experimental results are uIso presented...
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Linear-scaling calculation of Hartree-Fock exchange energy with Non-orthogonal Generalised Wannier Functions
PublicationWe present a method for the calculation of four-centre two-electron repulsion integrals in terms of localised non-orthogonal generalised Wannier functions (NGWFs). Our method has been imple- mented in the ONETEP program and is used to compute the Hartree-Fock exchange energy component of Hartree-Fock and Density Functional Theory (DFT) calculations with hybrid exchange-correlation functionals. As the NGWFs are optimised in situ...
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Installation of Compensators in the Power System Transmission Grid
PublicationThe article discusses issues of reactive power compensation in transmission grids, with particular focus on the selection of compensator locations and basic parameters. Attention was focused on modern power electronics systems that ensure full automatic compensator adjustment to voltage or power criteria.
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Thermal energy storage using stearic acid as PCM material
PublicationThis work presents an experimental study of thermal energy storage by use of PCM. The aim of the study was to establish the influence of different inlet temperature of heat transfer fluid (HTF) and different Reynolds number of HTF on intensity of charging process. The PCM used in this study was stearic acid and water was used as HTF. A copper helical coil mounted in cylindrical container served as a heat transfer surface.
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The luminescence study ofNaK2Li[Li3SiO4]4:Eu coumpounds.
Open Research DataNarrowband green phosphors with high quantum efficiency are required for backlighting white light-emitting diode (WLED) devices. Materials from the A[Li3SiO4]4:Eu2+ family have recently been proposed as having superior properties to industry-standard β-SiAlON green phosphors. Here, we show that a cheap, easily synthesized host NaK2Li[Li3SiO4]4 (NKLLSO)...
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Compact and Integrated High-Power Pulse Generation and Forming System
PublicationThis paper presents comprehensive analytical, numerical and experimental research of the compact and integrated high-power pulse generation and forming system based on the flux compression generator and the electro-explosive forming fuse. The paper includes the analysis of the presented solution, starting from the individual components studies, i.e., the separate flux compression generator tests in field conditions and the forming...
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The Efficiency of Post‐Communist Countries’ Health Systems
PublicationHealth‐care costs are a major financial burden for the transition economies, which have experienced rapidly increasing demand for health‐care services. The former communist countries of the Central and Eastern Europe and Central Asia needed to reform the financing of their health‐care systems and make efforts to strengthen the role of primary care while limiting the role of hospital care. The growing health needs and, consequently,...
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Enhance Color Rendering Index via Full Spectrum Employing the Important Key of Cyan Phosphor
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