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Wyniki wyszukiwania dla: OPERATING CONDITIONS
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A Microwave Sensor with Operating Band Selection to Detect Rotation and Proximity in the Rapid Prototyping Industry
PublikacjaThis paper presents a novel sensor for detecting and measuring angular rotation and proximity, intended for rapid prototyping machines. The sensor is based on a complementary split-ring resonator (CSRR) driven by a conductor-backed coplanar waveguide. The sensor has a planar topology, which makes it simple and cost-effective to produce and accurate in measuring both physical quantities. The sensor has two components, a rotor, and...
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Challenges in operating and testing loop heat pipes in 500–700 K temperature ranges
PublikacjaThe potential applications of loop heat pipes (LHPs) are the nuclear power space systems, fuel cell thermal management systems, waste heat recovery systems, medium temperature electronic systems, medium temperature military systems, among others. Such applications usually operate in temperature ranges between 500–700 K, hence it is necessary to develop an LHP system that will meet this requirement. Such a thermal management device...
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Design of synchronous generator two inputs regulator based on hinf control theory.
PublikacjaThe power system is highly nonlinear system, its dynamics depends on system network configuration, system loading… etc. To overcome the above mentioned difficulties and fulfill the performance requirements the different control methods are considered and tested for design of synchronous generator control system. Application of the H optimization method to synchronous generator regulator based on measurement of generator voltage...
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Design of synchronous generator voltage regulator based on h control theory
PublikacjaThe power system is highly nonlinear system, which dynamics depends on system network configuration, system loading…etc. To overcome the above mentioned difficulties and to fulfill the performance requirements the different control methods are considered and tested for application to generating control unit. Application of the H optimization method to automatic voltage regulator is studied in this paper. Simulation results have...
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Multi-stage magnetic-fluid seals for operating in water - life test procedure, test stand and research results. Part II Results of life tests of multi-stage magnetic - fluid seal operating in water
PublikacjaThe edge criteria for magnetic-fluid seals durability research were described in previous article [24] and now the tests results are presented. The tests were made with three magnetic fluids using various magnets quantity in magnetic assemblies. If values obtained in the repeated test deviated by more than 10 % from results of the first test an additional control test was made for final characteristics. The characteristics are:...
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Marine propeller shaft bearings under low-speed conditions: water vs. oil lubrication
PublikacjaThe bearings used in shipbuilding, hydropower, and water pumps have undergone a metamorphosis in recent decades. Because of environmental regulations, lubrication with grease or mineral oil is prohibited. Thus, the standard solutions include water-lubricated bearings with polymer bushings or sealed systems lubricated with oil. When properly designed, assembled, and operated, bearings can operate reliably for years. However, specific...
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Rapid dimension scaling of triple-band antennas by means of inverse surrogate modeling
PublikacjaGeometry scaling of antennas, i.e., finding optimum dimensions of the structure for given operating conditions and material parameters is an important yet challenging problem. In this paper, we discuss fast dimension scaling of triple-band antennas with respect to operating frequencies. We adopt the inverse surrogate modeling approach where the surrogate model is a function of the three operating frequencies of the antenna and...
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Integrated monitoring, control and security of Critical Infrastructure Systems
PublikacjaModern societies have reached a point where everyday life relies heavily on desired operation of critical infrastructures, in spite of accidental failures and/or deliberate attacks. The issue of desired performance operation of CIS at high security level receives considerable attention worldwide. The pioneering generic methodologies and methods are presented in the paper project for designing systems capable of achieving these...
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The operating field of a hydrostatic drive system. Parameters of the energy efficiency investigations of pump and hydraulic motors
PublikacjaPrzedstawiono pole pracy układu napędu hydrostatycznego. Uzasadniono podział parametrów pracy silnika hydraulicznego i pompy na parametry niezależne i zależne od pracy tych maszyn wyporowych i układu z nich utworzonego. Zaproponowano podjęcie tematu badawczego mającego na celu opracowanie metod wyznaczania charakterystyk energetycznych pomp i silników hydraulicznych obrotowych oraz zmodyfikowanych metod wyznaczania charakterystyk...
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Assessment of Financial Security of SMEs Operating in the Renewable Energy Industry during COVID-19 Pandemic
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Modification of the operating point of residual current transformers for high frequency earth fault currents detection
PublikacjaFor protection against electric shock in low voltage systems residual current devices are commonly used. However, their proper operation can be interfered when earth fault current with high frequency components occurs. Serious hazard of electrocution exists then. One of the most important element of residual current devices is a residual current transformer with iron core. Tripping characteristic of residual current devices strictly...
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Mobile inventory system for hydrotechnical objects using data from multiple sensors operating simultaneously
PublikacjaThe knowledge of the location, shape and other characteristics of spatial objects in the coastal areas has a significant impact on the functioning of ports, shipyards, and other water-infrastructure facilities, both offshore and inland. Therefore, measurements are taken of the underwater part of the waterside zone, which means the bottom of water and other underwater objects (e.g. breakwaters, docks, etc.), and objects above the...
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Conception of selecting reliability models for taking operating decisionsrelated to sea-going ship´s systems
PublikacjaPrzedstawiono możliwości podejmowania decyzji dotyczących sytuacji, gdy decydent dysponuje informacją aprioryczną o stanie technicznym urządzeń, na przykład uzyskaną z badań niezawodności urządzeń niezbędnych do wykonania zadania, wyrażoną w formie prawdopodobieństwa. Do opracowania modelu umożliwiającego podejmowanie takich decyzji eksploatacyjnych wykorzystano elementy bayesowskiej statystycznej teorii decyzji.
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Investigation of the Combustion Processes in the Gas Turbine Module of an FPSO Operating on Associated Gas Conversion Products
PublikacjaIn this paper, we consider the issue of thermo-chemical heat recovery of waste heat from gas turbine engines for the steam conversion of associated gas for offshore vessels. Current trends in the development of offshore infrastructure are identified, and the composition of power plants for mobile offshore drilling units and FPSO vessels is analyzed. We present the results of a comparison of power-to-volume ratio, power-to-weight...
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The congruence of mental models in entrepreneurial teams – implications for performance and satisfaction in teams operating in an emerging economy
PublikacjaPurpose – The paper aims to explore the relationship between the congruence of mental models held by the members of entrepreneurial teams operating in an emerging economy (Poland) and entrepreneurial outcomes (performance and satisfaction). Design/methodology/approach – The data obtained from 18 nascent and 20 established entrepreneurial teams was analysed to answer hypotheses. The research was quantitative and was conducted using...
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Optimisation of turbine shaft heating process under steam turbine run-up conditions
PublikacjaAn important operational task for thermal turbines during run-up and run-down is to keep the stresses in the structural elements at a right level. This applies not only to their instantaneous values, but also to the impact of them on the engine lifetime. The turbine shaft is a particularly important element. The distribution of stresses depends on geometric characteristics of the shaft and its specific locations. This means a groove manufactured...
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Boundary conditions for non-residential buildings from the user’s perspective: literature review
PublikacjaBackground and objective: This paper aims to review the boundary conditions (B/C) in specific categories (energy, building use, and lighting) within non-residential buildings to pave the way to a better understanding of users’ requirements and needs of the built environment. For this paper, B/C are understood as unique preconditions, specific characteristics for use, determining specific features of buildings, enabling an accurate...
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Analysis of Investments in RES Based on the Example of Photovoltaic Panels in Conditions of Uncertainty and Risk—A Case Study
PublikacjaThe aim of this study is to examine the profitability of investment in a photovoltaic microinstallation, to analyze the impact of legal changes on its profitability, and to perform a sensitivity analysis of the investment profitability to energy price changes. The novelty of the research applies to the financial analysis of two legal systems of discount called net-metering and net-billing. The two systems and the change in energy...
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Risk factor assessment in agricultural supply chain by fuzzy logic
PublikacjaSignificant uncertainty characterizes the harvest period. This aspect is due to various risks impacting agrifood supply chains. The occurrence of risks is due to hazards: technological failures, technical breakdowns, or adverse weather conditions. Hence, the operational time of the agricultural supply chain during the harvest period increases due to such risk factors. In essence, some hazards are fuzzy, and the nature of most threats...
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Face detection algorithms evaluation for the bank client verification
PublikacjaResults of investigation of face detection algorithms in the video sequences are presented in the paper. The recordings were made with a miniature industrial USB camera in real conditions met in three bank operating rooms. The aim of the experiments was to check the practical usability of the face detection method in the biometric bank client verification system. The main assumption was to provide as much as possible user interaction...
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AN IMPACT OF THE EFFICIENT FUNCTIONING OF THE VENTILATION AND AIR-CONDITIONING SYSTEM ON THERMAL COMFORT OF THE MEDICAL STAFF IN THE OPERATING ROOM
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Microstrip line with short-circuited edge as a high-pass filter operating up to millimeter-wave frequencies
PublikacjaPrzedstawiono prosty planarny filtr górnoprzepustowy wykorzystujący linię mikropaskową ze zwartym brzegiem. Układy zaprojektowano w taki sposób, aby pasmo przepustowe rozpoczynało się w zakresie K lub Ka. Wykonano dwa prototypy: na podłożu w postaci warstwy dielektrycznej wykonanej z ceramiki alundowej oraz na podłożu organicznym o niskiej przenikalności elektrycznej. Wykazano dużą zgodność teoretycznych i pomierzonych charakterystyk...
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The application of checklists in the field of complex operation based on the operating experiences of a liquefied petroleum gas handling simulator.
PublikacjaOmówiono pojęcie list sprawdzających (z ang. checklists). Podano charakterystykę techniczną symulatora operacji ładunkowych gazowca typu LPG znajdującego się w laboratorium Katedry Siłowni Okrętowych Akademii Morskiej w Gdyni wraz z jego możliwościami dydaktycznymi. Przedstawiono zasady tworzenia list sprawdzających czynności obsługowe wraz z przykładem takiej listy.
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A LUMPED-CIRCUIT MODEL OF CIRCULAR PISTON TRANSDUCER FOR MODELING ITS PERFORMANCE IN DUAL FREQUENCY OPERATING MODES
PublikacjaThe paper presents novel network equivalent circuit of piezoceramic circular disc transducer that takes into account thickness and ra dial mode of vibrations. The starting point of the analysis is 4-port description of circular disc element representing the solution of wave equation set in radial and thickness directions. Th e approximate solution for harmonic case is represented in the form of 4x4 matrix, which is syn thesized...
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Derivation of motor mean phase currents in PMSM drives operating with low switching-to-fundamental frequency ratio
PublikacjaPulse width modulation (PWM) of inverter output voltage causes the waveforms of motor phase cur-rents to consist of distinctive ripples. In order to provide suitable feedback for the motor current con-trollers, the mean value must be extracted from the currents’ waveforms in every PWM cycle. A com-mon solution to derive the mean phase currents is to sample their value at the midpoint of a symmetrical PWM cycle. Using an assumption...
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A Method of Fast and Simultaneous Calibration of Many Mobile FMCW Radars Operating in a Network Anti-Drone System
PublikacjaA market for small drones is developing very fast. They are used for leisure activities and exploited in commercial applications. However, there is a growing concern for accidental or even criminal misuses of these platforms. Dangerous incidents with drones are appearing more often, and have caused many institutions to start thinking about anti-drone solutions. There are many cases when building stationary systems seems to be aimless...
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Fast geometry scaling of miniaturized microwave couplers with power split correction
PublikacjaRedesigning a microwave circuit for various operating conditions is a practically important yet challenging problem. The purpose of this article is development and presentation of a technique for fast geometry scaling of miniaturized microwave couplers with respect to operating frequency. Our approach exploits an inverse surrogate model constructed using several reference designs that are optimized for a set of operating frequencies...
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Experimental investigation into surface texture effect on journal bearings performance
PublikacjaThe aim of this study was to analyse the performance of journal bearings with specially created dimples on the sliding surface and operating under various conditions. The texture was created on the bearing surface that co-acted with the smooth journal; moreover, the variation of the textured surface of the journal mating with the smooth bearing was tested, and the results were compared to those obtained with the standard smooth...
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The impact of environmentally friendly refrigerants on heat pump efficiency
PublikacjaThis paper discusses the issue of heat pump simulation. Lower operating costs can be achieved through good equipment design and appropriate operation. Detailed technical and economic analysis inform the selection of system components with the highest possible efficiency and lower energy demand. The use of systems based on environmentally friendly refrigerants can deliver long product life, which is associated with a shorter payback...
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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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Evaluation of Face Detection Algorithms for the Bank Client Identity Verification
PublikacjaResults of investigation of face detection algorithms efficiency in the banking client visual verification system are presented. The video recordings were made in real conditions met in three bank operating outlets employing a miniature industrial USB camera. The aim of the experiments was to check the practical usability of the face detection method in the biometric bank client verification system. The main assumption was to provide...
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Volumetric and torque efficiency of pumps during start-up in low ambient temperatures
PublikacjaThe volumetric, torque and total efficiency of hydraulic pumps change during start-up in low ambient temperatures, as well as in thermal shock conditions, un-til they reach the set conditions. The time to reach steady-state conditions de-pends on many parameters: ambient temperature, flow rate, fluid temperature, design of hydraulic units. The author carried out tests of hydraulic pumps in the Hydraulics Laboratory of the Faculty...
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Mutual Clutter Suppression Techniques for FM Sonars
PublikacjaThe article presents methods that help in the elimination of mutual clutter as well as the consequences of two FM sounding signal sonars operating in the same body of water and frequency band. An in-depth analysis of mutual clutter was carried out. The effects of sounding signal differentiation were determined, as was the Doppler effect on mutual clutter suppression. One of the methods analysed is of particular interest in a situation...
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Analysis of different tillage implements with respect to reduced fuel consumption, tractor operating speed and its wheel slippage
PublikacjaNowadays the prices of agricultural farm produced products are increasing with ant-speed and the prices of input for raising crops are increasing with rocket-speed. Therefore, there is a dire need to conduct some important studies to innovate the techniques which can lower the costs of crop production. In this context, this study was conducted to evaluate the consumption of fuel at different tillage implements, tractor operating...
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Two design concepts of power plant for an inland waterways passenger ship intended for operating on Berlin-Kaliningrad route
PublikacjaArtykuł przedstawia dwa rozwiązania siłowni dwuczłonowego, śródlądowego statku pasażerskiego przeznaczonego na trasę Berlin-Kaliningrad. Przedstawiono projekty wstępne siłowni głównej umieszczonej na pchaczu oraz omówiono wymagania odnośnie siłowni pomocniczej umieszczonej w barce.
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A method for evaluating theoretical and real operation of diesel engines in energy conversion formulation taking into account their operating indices
PublikacjaPrzedstawiono propozycję wartościowania (ilościowego określenia z uwzględnieniem wskaźników) działania dowolnego silnika o zapłonie samoczynnym, na przykładzie okrętowego silnika głównego, w którym zachodzą przemiany energetyczne w określonym czasie. Działanie to rozumiane jest jako przekazywanie energii śrubie napędowej w ustalonym czasie, w którym zachodzi przetwarzanie i przenoszenie energii w formie pracy bądź ciepła. Wartościowanie...
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Multi-stage magnetic-fluid seals for operating in water - life test procedure, test stand and research results
PublikacjaThe edge criteria for magnetic-fluid seals durability research are critical for the seal'stechnological usefulness. The magnetic fluid seal technology in water is much moredifficult technological problem in comparison to gas or vacuum environment. There isalways problem with immediate contact between magnetic fluid and the environmentaluninspected liquids. In the paper are presented ways of experiments definitions carried outwith...
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Cutting power estimation of the bandsawing process of beech wood (Fagus sylvatica L.) dried in three operating modes
PublikacjaIn this paper the predicted values of cutting power for bandsawing machine (ST100R, f. Stenner), which is located at the sawmill company Complex in Dziemiany, were presented. The values of cutting power were forecasted for beech wood (Fagus sylvatica L.), from the northern part of Pomerania region in Poland, which was dried in three operating modes: BKP - air drying at 25oC, BKS - air-steam mixture drying at 80oC, BKW - steam drying...
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The performance of H2O, R134a, SES36, ethanol, and HFE7100 two-phase closed thermosyphons for varying operating parameters and geometry
PublikacjaIn this study, the influences of different parameters at performance two-phase closed thermosiphon (TPCT) was presented. It has been confirmed that the working fluid, as well as operating parameters and fill ratio, are very important factors in the performance of TPCT. The article shows characteristics of gravitational tube geometr ies, as well as the technical characteristic of the most important system components, i.e., the evaporator/condenser....
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Thermodynamic and economic analysis of nuclear power unit operating in partial cogeneration mode to produce electricity and district heat
PublikacjaThis paper presents the methodology of techno-economic analysis for a nuclear unit operating in partial cogeneration mode and its application for the case study: a nuclear power plant planned in Poland. The research objectives were: to propose EPR, AP1000 and ESBWR nuclear condensing-extraction turbine systems modifications required for operation in cogeneration, to determine optimal heat production and heat transport line (HTL)...
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INVESTIGATIONS OF THE EMISSION CHARACTERISTICS OF A DUAL-FUEL GAS TURBINE COMBUSTION CHAMBER OPERATING SIMULTANEOUSLY ON LIQUID AND GASEOUS FUELS
PublikacjaT his study is dedicated to investigations of the working process in a dual-fuel low-emission combustion chamber for a floating vessel’s gas turbine. As the object of the research, a low-emission gas turbine combustion chamber with partial premixing of fuel and air inside the outer and inner radial-axial swirls was chosen. The method of the research is based on the numerical solution of the system of differential...
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SIMPLIFIED MODELING OF STRESS AND DEFLECTION LIMIT STATES OF UNDERGROUND TANKS
PublikacjaFuel tanks are designed with regard to standard actions and operating conditions. The work analyses the impact of corrosion and other means to variation of stresses and deformation of a horizontal underground tank shell. The computations are preliminary. Due to the long computational time of the entire tank the analysis is restricted to its part only. The full analysis is bound to assess structural reliability, further allowing...
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Rapid and Reliable Re-Design of Miniaturized Microwave Passives by Means of Concurrent Parameter Scaling and Intermittent Local Tuning
PublikacjaRe-design of microwave passive components for the assumed operating frequencies or substrate parameters is an important yet a tedious process. It requires simultaneous tuning of relevant circuit variables, often over broad ranges thereof, to ensure satisfactory performance of the system. If the operating conditions at the available design are distant from the intended ones, local optimization is typically insufficient, whereas...
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Performance of the Direct Sequence Spread Spectrum Underwater Acoustic Communication System with Differential Detection in Strong Multipath Propagation Conditions
PublikacjaThe underwater acoustic communication (UAC) operating in very shallow-water should ensure reliable transmission in conditions of strong multipath propagation, significantly disturbing the received signal. One of the techniques to achieve this goal is the direct sequence spread spectrum (DSSS) technique, which consists in binary phase shift keying (BPSK) according to a pseudo-random spreading sequence. This paper describes the DSSS...
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Algorithms and Tools for Intelligent Control of Critical Infrastructure Systems
PublikacjaCritical Infrastructure Systems (CIS) are spatially distributed and of a network structure. The dynamics are nonlinear, uncertain and with several time scales. There is a variety of different objectives to be reliably met under a wide range of operational conditions. The operational conditions are influenced by the disturbance inputs, operating ranges of the CIS, faults in the sensors and actuators and abnormalities occurring in...
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Probabilistic estimation of diverse soil condition impact on vertical axis tank deformation
PublikacjaThe calculations of fuel tanks should take into account the geometric imperfections of the structure as well as the variability of the material parameters of the foundation. The deformation of the tank shell can have a significant impact on the limit state of the structure and its operating conditions. The paper presents a probabilistic analysis of a vertical-axis, floating-roof cylindrical shell of a tank with a capacity of 50000...
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Impact of rotor geometry optimization on the off-design ORC turbine performance
PublikacjaThe paper describes the method of CFD based Nelder-Mead optimization of a 10 kW single-stage axial turbine operating in an ORC system working on R7100. The total-to-static isentropic efficiency is defined as an objective function. Multi-point linear regression is carried out to determine the significance of the objective function arguments and to pick up the set of particular variables and characteristic quantities (e.g. flow angles)...
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Economical analysis of selected variants of power plant for inland waterways passenger ship intended for operating on Berlin-Kaliningrad route
PublikacjaW artykule przedstawiono analizę ekonomiczną trzech wariantów siłowni śródlądowego statku pasażerskiego przeznaczonego na trasę Berlin-Królewiec. Określono koszty inwestycyjne oraz koszty zużycia paliwa przez porównywalne siłownie. Wykorzystano wskaźniki ekonomiczne: AAC oraz NPV.
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The Concept of a Methodology for Selecting the Optimal Parameters of Heat Received from a Nuclear Power Plant Operating in a Partial Cogeneration Mode
PublikacjaThe paper presents the concept of the objective function which is to allow the selection of optimal parameters of the district heating system using a nuclear power plant operating in partial cogeneration mode. The concept is based on research carried out a number of years ago. The size of annual expenses was proposed as the objective function, which allows to compare the operation of a nuclear power plant in partial cogeneration...
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Exhaust gas temperature measurements in diagnostic examination of naval gas turbine engines. Part III. Diagnostic and operating tolerances
PublikacjaThe third part of the article presents a method for detecting failures of the automatic engine control system with the aid of an exhaust gas temperature setter, specially designed and machined for this purpose. It also presents a procedure of identifying the operating tolerances and determining the diagnostic tolerances for the exhaust gas temperature recorded in the naval turbine engine during the start-up and acceleration processes....