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Wyniki wyszukiwania dla: energy system modelling
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Modeling and experimental investigation of the small UPQC systems
PublikacjaIn this paper the basis of analytical modelling of the UPQC arrangements (Unified Power Quality Conditioner) in d-q rotating coordinates, as well as select results of investigations conducted on the simplified small power laboratory model were talked over. In short form power balance as well as fundamental dependences and analytic model with regard of decoupling circuits were investigated. Applied method for DC link capacity selection...
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Design of power cable lines partially exposed to direct solar radiation – special aspects
PublikacjaPower cable lines are usually buried in the ground. However, in some cases, their ending sections are mounted along the supports of overhead lines. This leads to a situation where the cables are exposed to direct solar radiation and, consequentially, overheat. The paper presents the advanced computer modelling of power cables’ heating, considering their insolation as well as the effect of wind. The temperature and current-carrying...
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Modeling of performance of an AUV stealth vehicle. Design for operation.
PublikacjaIn the paper some results of research connected with modelling of performance and risk assessment of an AUV stealth vehicle are presented. A general approach to design of the stealth AUV autonomous underwater vehicle under consideration is introduced. The basic stealth characteristics of the AUV stealth vehicle are briefly described. The method of research is introduced. The AUV stealth vehicle concept is presented including the...
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Human Resource Management Digitalisation in Multidisciplinary Ship Design Companies
PublikacjaThe digitalisation in the ship design sector is currently applied to the design process itself and is well defined, partially standardised and practically implemented by both independent design companies and the design departments of shipyards. The situation is similar in other sectors of engineering. However, the requirements for the digitalisation of other processes in design and engineering companies have not previously been...
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Application of mechanistic and data-driven models for nitrogen removal in wastewater treatment systems
PublikacjaIn this dissertation, the application of mechanistic and data-driven models in nitrogen removal systems including nitrification and deammonification processes was evaluated. In particular, the influential parameters on the activity of the Nitrospira activity were assessed using response surface methodology (RSM). Various long-term biomass washout experiments were operated in two parallel sequencing batch reactor (SBR) with a different...
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Potential for ITS/ICT Solutions in Urban Freight Management
PublikacjaThe article presents a study on applying ITS solutions in planning and management of urban freight transport in Gdynia. The traffic management system Tristar which is under implementation and its related systems show a potential to assist in development of freight transport measures. Recommendations for urban freight policy development supplementing Gdynia's Sustainable Urban Mobility Plan were used as a basis for identification...
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The energy concept of money
PublikacjaPurpose: This paper aims to provide the literature review seeking an answer whether energy can be used as a universal equivalent instead of money. Methodology: The author conducted a review of available literature and data sources related to the money theory and energy concept of money. Findings: It was found that the definition of energy as a general equivalent has a contextual and dynamic nature, and this field’s consolidation...
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Expert System as a classification method for optimal Legg-Calve-Perthes Disease treatment
PublikacjaZaproponowano utworzenie systemu eksperckiego jako metody klasyfikacji w prognozowaniu dowolnej formy leczenia dzieci z chorobą Legg-Calve-Perthesa. Obecnie nie ma jednego optymalnego sposobu leczenia choroby Perhtes'a i proponowana metoda jest próbą utworzenia wymiernego i uniwersalnego narzędzia, które będzie stanowiło podstawę przy podejmowaniu decyzji o najlepszym sposobie leczenia chorego stawu biodrowego. System ekspercki,...
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Renewable Energy Sources on the Polish Electrical Energy Market
PublikacjaProduction of electricity from renewable energu sources in Poland is presented in the paper.The machanism of energy origin certifikates market and the proposal of mechanism modification are discused.
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Solar Photovoltaic Energy Optimization and Challenges
PublikacjaThe study paper focuses on solar energy optimization approaches, as well as the obstacles and concerns that come with them. This study discusses the most current advancements in solar power generation devices in order to provide a reference for decision-makers in the field of solar plant construction throughout the world. These technologies are divided into three groups: photovoltaic, thermal, and hybrid (thermal/photovoltaic)....
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LattE- first-principles lattice energy calculations
PublikacjaCrystal engineering is currently attracting much interest. Its aim is to create materials of predefined properties fulfilling the requirements imposed by the applications. There are several parameters describing crystal structures, but the most important one is probably the energy of a crystal lattice. It is the energy released by the system when crystalline solid is formed out of molecules or ions in gaseous phase. Approximate...
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Propulsion system with a hydraulic transmision for a low draught inland vessel
PublikacjaW artykule przedstawiono założenia i uwarunkowania techniczne oraz projekt koncepcyjny dwóch wariantów układu napędowego statku śródlądowego o małym zanurzeniu. Oba warianty dotyczą systemu Diesel-hydraulicznego, przy czym pierwszy - z tradycyjną, poziomą linią wałów i śrubami stałymi w wychylnych dyszach Korta, a drugi - z pędnikami azymutalnymi. Projekt zawiera schemat systemu napędowego oraz wizualizację rozmieszczenia podstawowych...
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Generalized regression neural network and fitness dependent optimization: Application to energy harvesting of centralized TEG systems
PublikacjaThe thermoelectric generator (TEG) system has attracted extensive attention because of its applications in centralized solar heat utilization and recoverable heat energy. The operating efficiency of the TEG system is highly affected by operating conditions. In a series-parallel structure, due to diverse temperature differences, the TEG modules show non-linear performance. Due to the non-uniform temperature distribution (NUTD) condition,...
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Losses and energy efficiency of drive motors and systems
PublikacjaLosses and energy efficiency of every drive motor must be presented as functions of physical quantities independent of losses in the motor. Such quantities are speed and load required by the machine or device driven by the motor, changing in the drive operating field. Speed and load of the motor decide of the instantaneous useful power of the motor and also in a differentiated way of kinds and values of losses occurring in the...
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Losses and energy efficiency of drive motors and systems
PublikacjaLosses and energy efficiency of every drive motor must be presented as functions of physical quantities independent of losses in the motor. Such quantities are speed and load required by the machine or device driven by the motor, changing in the drive operating field. Speed and load of the motor decide of the instantaneous useful power of the motor and also in a differentiated way of kinds and values of losses occurring in the...
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Design and Performance Evaluation of the Energy Subsystem of a Hybrid Light andWave Energy Harvester
PublikacjaThe paper presents the design and performance of an energy subsystem (ES) dedicated to hybrid energy harvesters (HEHs): wave energy converters (WECs) combined with photovoltaic panels (PVPs). The considered ES is intended for compact HEHs powering autonomous end-node devices in distributed IoT networks. The designed ES was tested experimentally and evaluated in relation to the mobile and wireless distributed communication use case....
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Modification of Selected Propagation Models in Terms of Path Loss Estimation in Container Terminal
PublikacjaIt is particularly important to look for any propagation model that could be useful for designing mobile radio networks in container terminal environment. Selected propagation models have been investigated. Firstly - basing on measurements results - they have been evaluated in this scope and the analysis has shown, that the adjustment is needed. This modification improved significantly the accuracy of path loss modelling. For the...
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Electromagnetic interference frequencies prediction model of flyback converter for snubber design
PublikacjaSnubber design for flyback converters usually requires experimental prototype measurements or simulation based on accurate and complex models. In this study simplified circuit modelling of a flyback converter has been described to dimension snubbers in early stage of design process. Simulation based prediction of the transistor and diode ringing frequencies has been validated by measurements in a prototype setup. In that way obtained...
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Evolutionary Sets of Safe Ship Trajectories: Evaluation of Individuals
PublikacjaThe paper presents a description of the evaluation phase of the Evolutionary Sets of Safe Ship Trajectories method. In general, the Evolutionary Sets of Safe Ship Trajectories method combines some of the assumptions of game theory with evolutionary programming and finds an optimal set of cooperating trajectories of all ships involved in an encounter situation. While developing a new version of this method, the authors decided to...
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Impact of thermal loading into the structural performance of ships: A review
PublikacjaThe presented study reviews the recent advances done regarding the impact of thermal loading on the structural performance of ships. Firstly, the studies related to the mechanical and thermal properties of typical materials used in shipbuilding are outlined. Secondly, a brief introduction to the heat transfer analysis, Finite Element modelling and thermal stresses is provided. Finally, the review of papers dealing with the structural...
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The effect of current delay angle on tripping of residual current devices
PublikacjaPower electronics converters applied in domestic or similar installations may utilize current delay (phase) angle control to change the level of transferred power. Due to application of such types of converters, earth fault current in the installation may be strongly distorted. The current distortion level depends on a value of current delay angle. This delay angle also influences the tripping threshold of residual current devices....
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The Effect of Protrusions on the Initiation of Partial Discharges in XLPE High Voltage Cables
PublikacjaThis paper is focusing on 3D Finite Elements Analysis (FEA) based modelling of protrusions as defects or imperfections in the XLPE high voltage cable. This study is aiming to examine the impact protrusions have on the initiation of partial discharges. Spherical and ellipsoidal protrusions with different sizes at the conductor screen of the high voltage cable is an essential content of this paper. In addition, a spherical gas-filled...
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CFGFRPT Piles with a Circular Cross-Section and their Application in Offshore Structures
PublikacjaThe possibilities of using concrete piles in a polymer composite reinforced with glass fibres in offshore facilities were shown. Laboratory tests of CFGFRPT type piles compressed axially and in eccentric compression for the analysis of CFGFRPT piles were used. Methods of analysis of dynamic systems for mathematical modelling of the displacement of the hammer in the pile driving process were applied. The possibilities of combining...
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Electromagnetic-based derivation of fractional-order circuit theory
PublikacjaIn this paper, foundations of the fractional-order circuit theory are revisited. Although many papers have been devoted to fractional-order modelling of electrical circuits, there are relatively few foundations for such an approach. Therefore, we derive fractional-order lumped-element equations for capacitors, inductors and resistors, as well as Kirchhoff’s voltage and current laws using quasi-static approximations of fractional-order...
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Development of the Polish energy sector through transformation and harmonization with the European energy and climate policy
PublikacjaThe paper presents the dilemmas of energy sector development vs European energy policy due to the way of energy transition. The identification of barriers and opportunities for the development of the power industry is presented. The possibilities of using modern energy technologies for the processes of energy transformation are described. The path useful to achieving climate and energy goals is determined. The new method of electricity...
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Technical and economic analysis of energy storage in the compressed air technology with low capacity for the production plant
PublikacjaCompressed air energy storage (CAES) system is a promising technology due to its numerous advantages, including relatively low maintenance cost, a long lifespan and high operational flexibility. This article explores the possibility of designing a CAES power plant as a source of electricity and heat for an existing industrial plant. The study involves the technical analysis of the power plant parameters and the economic analysis...
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Game theory-based virtual machine migration for energy sustainability in cloud data centers
PublikacjaAs the demand for cloud computing services increases, optimizing resource allocation and energy consumption has become a key factor in achieving sustainability in cloud environments. This paper presents a novel approach to address these challenges through an optimized virtual machine (VM) migration strategy that employs a game-theoretic approach based on particle swarm optimization (PSO) (PSO-GTA). The proposed approach leverages...
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Rational Use of Primary Energy in Single-Family Residential Houses
PublikacjaThis work presents results of the primary energy use for heating residential single-family house. Analysis includes domestic hot water system (DHW) and heating, ventilation and air condition system (HVAC). During researches the conventional and alternative energy sources (natural gas, biomass, fuel oil, bituminous coal, lignite or electric energy obtained from electric power system – EPS) were used in DHW and HVAC systems. Furthermore...
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Reliable renewable energy – application of electrochemical capacitors for electrical energy storage
PublikacjaThis paper presents electrical energy storage devices such as electrochemical capacitors, their principle of operation and electrode materials most commonly used in their manufacturing technology. Moreover, our research on development of new nanocomposite materials based on multi-walled carbon nanotubes and conducting polymer is shown. Additionally, the possibility and advantages of application of supercapacitors for accumulation...
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Deep learning for ultra-fast and high precision screening of energy materials
PublikacjaSemiconductor materials for energy storage are the core and foundation of modern information society and play important roles in photovoltaic system, integrated circuit, spacecraft technology, lighting applications, and other fields. Unfortunately, due to the long experiment period and high calculation cost, the high-precision band gap (the basic characteristic parameter) of semiconductor is difficult to obtain, which hinders the...
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Evolutionary Sets of Safe Ship Trajectories: Evaluation of Individuals
PublikacjaThe paper presents a description of the evaluation phase of the Evolutionary Sets of Safe Ship Trajectories method. In general, the Evolutionary Sets of Safe Ship Trajectories method combines some of the assumptions of game theory with evolutionary programming and finds an optimal set of cooperating trajectories of all ships involved in an encounter situation. While developing a new version of this method, the au-thors decided...
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The use of mathematical models for diagnosis of activated sludge systems in WWTP
PublikacjaIn this study diagnosis of activated sludge systems in wastewater treatment plant (WWTP) was investigated. Diagnosis of technical objects can be realized in many ways. One of the divisions of the diagnostic methods include modelling with or without a model of the object. The first of these is the analysis of the symptoms for which, based on the parameter values, the abnormality in the diagnosed objects are sought. Another way is...
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Different sources of market information and product innovativeness
PublikacjaThe purpose of this study is to identify whether the gathering of market information from different sources – i.e. from customers, competitors and other entities – is related to product innovativeness. The relationships proposed so far have not been empirically investigated but they can have important theoretical and practical implications for product innovation. To achieve the purpose of the paper data concerning 287 new products...
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Shape Optimisation of Kaplan Turbine Blades Using Genetic Algorithms
PublikacjaThis monograph is a comprehensive guide to a method of blade profile optimisation for Kaplan-type turbines. This method is based on modelling the interaction between rotor and stator blades. Additionally, the shape of the draft tube is investigated. The influence of the periodic boundary condition vs. full geometry is also discussed. Evolutionary algorithms (EA) are used as an optimisation method together with artificial neural...
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A comparative performance assessment of a hydrodynamic journal bearing lubricated with oil and magnetorheological fluid
PublikacjaThis work presents the investigation results of a journal bearing lubricated with magnetorheological fluid that is activated by a local constant magnetic field to vary both the local flow resistance and pressure. The bearing performance is assessed via Finite Element Modelling (FEM) and results are corroborated by experiments. The FEM model uses the Bingham model to describe the fluid film. A dedicated test rig is used to assess...
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The Use of Cluster Analysis to Evaluate the Impact of COVID-19 Pandemic on Daily Water Demand Patterns
PublikacjaProper determination of unitary water demand and diurnal distribution of water consumption (water consumption histogram) provides the basis for designing, dimensioning, and all analyses of water supply networks. It is important in the case of mathematical modelling of flows in the water supply network, particularly during the determination of nodal water demands in the context of Extended Period Simulation (EPS). Considering the...
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The application of nonlinear curvature sections in the turnout diverging track
PublikacjaThe paper presents the analytical method of modelling the diverging track of railway turnout with nonlinear curvature sections. These sections were used for smoothing the graph of curvature in the extreme areas of turnout. The problem of the curvature distribution was identified with the use of differential equations. The resulting solutions are of universal nature for example the ability of assuming any values of curvature at...
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Nested Kriging Surrogates for Rapid Multi-Objective Optimization of Compact Microwave Components
PublikacjaA procedure for rapid EM-based multi-objective optimization of compact microwave components is presented. Our methodology employs a recently developed nested kriging modelling to identify the search space region containing the Pareto-optimal designs, and to construct a fast surrogate model. The latter permits determination of the initial Pareto set, further refined using a separate surrogate-assisted process. As an illustration,...
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Global Optimization for Recovery of Clipped Signals Corrupted With Poisson-Gaussian Noise
PublikacjaWe study a variational formulation for reconstructing nonlinearly distorted signals corrupted with a Poisson-Gaussian noise. In this situation, the data fidelity term consists of a sum of a weighted least squares term and a logarithmic one. Both of them are precomposed by a nonlinearity, modelling a clipping effect, which is assumed to be rational. A regularization term, being a piecewise rational approximation of the ℓ0 function...
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Decision support system for design of long distance heat transportation system
PublikacjaDistrict Heating (DH) systems are commonly supplied using local heat sources. Nowadays, modern insulation materials allow for effective and economically viable heat transportation over long distances (over 20 km). The paper proposes a Decision Support System (DSS) for optimized selection of design and operating parameters of a long distance Heat Transportation System (HTS). The method allows for evaluation of feasibility and effectiveness...
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Proposed Amendments to Reactive Energy Billing
PublikacjaThis paper describes possible amendments to the rules of reactive energy billing in the tariffs in Poland. Modifications in the tariffs to improve their motivational function for distribution system users are identified as the most expedient. New problems arising from distributed generator operations are also indicated. A billing method that can be effectively implemented at the occurrence of distorted voltage and current waveforms...
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Directions of Energy Transition of Uzbekistan
PublikacjaThe aim of the paper is to present the changes in the Uzbekistan energy market over the past few years. Uzbekistan is self-sufficient in terms of energy resources, the exploitation of which will last for many years. In 2019, the government adopted the "Concept Note ensuring electricity supply in Uzbekistan in 2020-2030" strategy, which announced the modernization of gas and coal power plants and the construction of new energy facilities,...
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Energy efficiency of electric multiple units in suburban operation
PublikacjaThis 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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A framework to analyse the probability of accidental hull girder failure considering advanced corrosion degradation for risk-based ship design
PublikacjaShip’s hull girder failure could result from maritime accident that can cause human life loss, environmental disaster, and major economic impacts. In risk-based ship design paradigm, accounting for rare phenomena (e.g. ship-ship collision or grounding) is important to provide safe and durable structure. In-service corrosion-induced hull degradation should be considered at the design stage, as it can significantly affect structural...
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Charakterystyka eksploatacyjna pomp ciepła zainstalowanych w oczyszczalni ścieków
PublikacjaW artykule przedstawiono charakterystykę eksploatacyjną sprężarkowych pomp ciepła zainstalowanych w oczyszczalni komunalnej i wykorzystujących ścieki oczyszczone jako dolne źródło ciepła. Zastosowanie ścieków oczyszczonych jest uzasadnione ich dostępnością oraz stosunkowo wysoką temperaturą (10-25°C). Prawidłowa eksploatacja układu wymaga zastosowania pośredniego obiegu parowacza oraz regularnych zabiegów czyszczenia wymiennika...
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Ukraine’s Energy Security in Strategies
PublikacjaDuring the independence period, the Ukrainian government has published two energy security strategies. The first strategy was adopted in 2006 and the second one in 2016. Both documents provided a similar definition of energy security. The aims of the first strategy, covering the period 2006–2030, were the restructuring of the fuel and energy complex using new technologies, increase of energy efficiency and ensuring market prices...
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DFMA guidelines and a data base system in integrated development of hydraulic pumps
PublikacjaPrzedstawiono koncepcję budowy systemu decyzyjnego, dla zintegrowanego rozwoju pomp hydraulicznych oraz doboru adekwatnych technik wytworzenia komponentów i procesów montażu, z zastosowaniem metodyki SADT/IDEF0 oraz ogólnych wytycznych DFMA. Omówiono stosowane w przemyśle krajowym konstrukcje pomp zębatych z łożyskami tocznymi oraz udoskonalone rozwiązania projektowe tych pomp z łożyskami ślizgowymi (polimerowymi). Wskazano na...
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Taking advantage of the shared explicit cache system based critical sections in the shared memory parallel architectures
PublikacjaArtykuł prezentuje nową metodę implementacji sekcji krytycznych w równoległych architekturach z pamięcią współdzieloną, takich jak systemy zintegrowane wielowątkowe wieloprocesorowe. Metoda stanowi modyfikację i rozbudowanie metody zwanej Folding, dostępnej w procesorach sieciowych oraz jest w założeniach podobna do techniki zwanej cache-based locking. W porównaniu do dostępnych metod, nowa metoda usuwa problemy skalowalności i...
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The Energy of Finance in Refining of Medical Surge Capacity
PublikacjaThe availability of resources and their concentration in the place of greatest need, will not allow us to successfully overcome a medical surge without the energy required to activate these resources and activities, and increase their quantities if necessary, that is why the staff and management of healthcare institutions are forced to making ethical crisis decisions about who wins and who loses. This study highlights the versatility...
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LEGAL ASPECTS OF ELECTRIC ENERGY GENERATION IN A FLOATING POWER PLANT
PublikacjaThis paper discusses the characteristics of pollution and legal regulations governing investment projects affecting the environment. It describes a combined system of a compression ignition engine and a steam turbine, whose aim, when placed on a floating platform, is to produce electric energy in a so-called distributed generation system. Such a system involves a reciprocating internal combustion engine and a connected steam turbine...