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Search results for: ISLANDING OPERATION
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ANALYSIS OF DIESEL OIL SPECIFIC HEAT IMPACT FOR OPERATION OF THE SUPPLY PUMP
PublicationThe article describes a test rig that allows the measurement of fuel oil specific heat changes based on the cooling time of liquids. After that, by analysing the test results, a research hypothesis was created and verified. The hypothesis is that the specific heat energy of fuel oil impact the operation of the circulation pump.
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Development of cooperation in localized cooperation networks: A comparative study of cluster organizations and technology parks
PublicationThe main aim of the paper is to analyze the level of development of cooperative relationships in localized cooperation networks – among enterprises associated in cluster organizations and park tenants. The author reports the findings from the quantitative study carried out in the selected cluster organizations and technology parks functioning in Poland. The basic method of data collection was a survey questionnaire. The research...
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Standing Acoustic Waves and Relative Nonlinear Phenomena in a Vibrationally Relaxing Gas-Filled Resonator
PublicationStanding acoustic waves in one-dimensional resonator filled with vibrationally relaxing gas, are studied. Two regimes of excitation of molecular vibrational degrees of freedom are considered, equilibrium and nonequilibrium. The acoustic energy enlarges with time in the non-equilibrium regime and decreases otherwise before formation of discontinuity. After that, it decreases due to nonlinear absorption and tends to zero in equilibrium...
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The geometry of free-standing titania nanotubes as a critical factor controlling their optical and photoelectrochemical performance
PublicationTitanium dioxide nanotubes are regarded as one of the most important functional materials and due to their unique electronic properties, chemical stability and photocorrosion resistance, they find applications in, for example, highly efficient photocatalysis or perovskite solar cells. Nevertheless, modification of TiO2 nanotubes is required to overcome their main drawback, i.e. large energy bandgap (>3.2 eV) limiting their ability...
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Optimization of Energetic Train Cooperation
PublicationIn the article, possible ways of using energy recovered during regenerative braking of trains are presented. It is pointed out that the return of recovered electricity directly to the catenary and its use in the energy cooperation of vehicles can be a no-cost method (without additional infrastructure). The method of energy cooperation between trains and its main assumptions, that uses the law of conservation of energy, are described...
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An analysis of ship escort and convoy operations in ice conditions
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ANALYSIS OF INTERNAL SOURCES OF HAZARDS IN CIVIL AIR OPERATIONS
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Analysis of external sources of hazards in civil air operations
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Organization of technical rescue operations in the national rescue system
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Revolutionizing SME Management: The Digital Transformation of Financial Operations
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Credibility of Business Operations via Internet: Customer Perspective
PublicationTourism plays an important role in economy of Mediterranean countries. Year after year, more and more people spend or like to spend their vacations (and money) in the Mediterranean region. Hiring private apartments or houses by individual persons for themselves and their families becomes more and more popular way of vacation arrangement and, in the result, constitutes an important factor of the countries' incomes. Versatile and...
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The spindle speed optimal control in modern milling operations.
PublicationPraca dotyczy modeli obrabiarek ze sprzężeniem zwrotnym, w przypadku których istotne znaczenie mają drgania samowzbudne typu chatter. Opis układu drgającego przedstawiono w postaci dynamiki układu sterowanego, przy czym sygnałem sterującym jest chwilowa zmiana prędkości obrotowej wrzeciona. Rozważano frezowanie czołowe smukłym frezem trzpieniowym na pionowym cent rum frezarskim. Przedstawiono rezultaty przykładów symulacji komputerowych....
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Recognition of input items to the logistic operations in accommodation services
PublicationIn this study the authors set themselves the aim to analyze the elements of the entrance to the accommodation services in terms of logistics. Therefore, providers of this type of services were examined. This allowed to carry out analyses also with including the variety of accommodation services
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Implementation of Addition and Subtraction Operations in Multiple Precision Arithmetic
PublicationIn this paper, we present a digital circuit of arithmetic unit implementing addition and subtraction operations in multiple-precision arithmetic (MPA). This adder-subtractor unit is a part of MPA coprocessor supporting and offloading the central processing unit (CPU) in computations requiring precision higher than 32/64 bits. Although addition and subtraction operations of two n-digit numbers require O(n) operations, the efficient...
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Assessment of the Reliability of Wind Farm Device on the Basis of Modeling Its Operation Process
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Turning maneuver as a potential cause of the next stability failure mode for a ship in operation
PublicationThe only formal stability-related requirement referring to a turning maneuver of a ship results from the IS Codeand its application is limited to passenger ships only. The goal of the adopted criterion is to prevent an excessiveangle of heel in turn. Likewise, the remaining prescriptive criteria, this one is simply based on the concept ofa threshold that must not be exceeded. In this case, the angle of heel...
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Safe Operation of Underground Mining Vehicles Based on Cyclic Fatigue Monitoring of Powertrains
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Selected problems of determining an efficient operation standard in contemporary heat-and-flow diagnostics
PublicationW referacie wymieniono przyczyny powodujące niejednoznaczności i trudności wyznaczania wzorca sprawnej pracy turbinowych siłowni lądowych i morskich. Przeanalizowano dwie z tych przyczyn: obniżenie wartości parametrów dolotowych czynników roboczych oraz zmiany w konfiguracji połączeń pomiędzy urządzeniami składowymi obiegów cieplnych. Jako remedium na wynikające stąd trudności zaproponowano model obliczeniowy obiegu cieplnego o...
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Białowieża primeval forest as an example of transfrontier co-operation between Poland and Bielarus
PublicationThe Polish Ministry of Foreign Affairs is completing their work on the agreement on local border traffic (May 2009.) At the final stage of the works, the list of the towns and villages situated within the area covered by the so-called "local traffic" on both the Polish and the Belarusian sides of the border is being verified. The "border belt" area, whose residents will be able to move between the bordering countries under the...
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The time of the first transition of the semi-Markov process in the evaluation of diesel engine operation
PublicationW referacie przedstawiono rozwinięcie prezentowanej w literaturze metody ilościowej oceny działania na przykładzie okrętowego silnika głównego z zapłonem samoczynnym. Według tej interpretacji, działanie silnika może zostać przedstawione jako wielkość fizyczna. W tym aspekcie, na przykładzie okrętowego silnika napędu głównego dokonano oceny przydatności tej wielkości do opisu własności niezawodnościowych silnika. Precyzyjne określenie...
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Valuation method for operation of crankshaft-piston assembly in combustion engines in energy approach
PublicationPrzedstawiono propozycję wartościowania (ilościowego określenia) działania dowolnego układu korbowo-tłokowego silnika o zapłonie samoczynnym, w którym zachodzą oddziaływania energetyczne w określonym czasie. Działanie to rozumiane jest jako przekazywanie odbiornikowi energii w ustalonym czasie, w którym zachodzi przetwarzanie i przenoszenie energii w formie pracy i ciepła. Wartościowanie działania układów korbowo-tłokowych silników...
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Experiences from operation of different expansion devices for application in domestic micro CHP
PublicationW pracy opisano doświadczenia zdobyte podczas badań trzech różnych urządzeń ekspansyjnych, możliwych do zaimplementowania w mikrosiłowni CHP. Przebadano ekspander wykonany na bazie sprężarki spiralnej oraz dwojakiego rodzaju silniki pneumatyczne. Wykazano "wyższość" maszyn pneumatycznych nad ekspanderem typu scroll, uzyskując sprawności wewnętrzne w zakresie 61-82%. Dodatkowo, mniejsza objętość i masa urządzeń pneumatycznych stanowi...
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The sources of contamination and reasons of damage of the flow part of the marine turbine engine in operation
PublicationThe aim of this paperis to show particular sensitivity of the flow part of the marine turbine engine to the presence of contaminations in the intake air. The contaminations form hard-to-remove deposits in the intervene channels that result in a reduced efficiency and performance of the engine. The paper classifies the contaminants according the source of their formation and their destructive force. The performed analyses and syntheses...
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Influence of circuit breaker operation upon transformeros residual flux and inrush current
PublicationPrzedstawiono model i wyniki obliczeń prądu i strumienia magnetycznego w układzie zawierającym transformator trójfazowy i wyłącznik. Opracowano obwodowy model łącznika z łukiem elektrycznym. Model łuku zbudowano w oparciu o jego statyczną charakterystykę prądowo-napięciową z uwzględnieniem uproszczonej charakterystyki dynamicznej. Przeprowadzone symulacje wykazały, że wartość maksymalna prądu włączania transformatora zależy zarówno...
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Loads of ship main diesel engine in the aspect of practical assessment of its operation
PublicationW artykule przedstawiono koncepcję metody pozwalającej na ocenę działania silnika pracującego na obciążeniu częściowym. Do określenia istniejącego zapasu parametrów użytkowych silnika oraz związanych z degradacją jego stanu technicznego dodatkowych kosztów ponoszonych przez użytkownika wykorzystane zostało wartościujące (ilościowe) ujęcie działania interpretowanego jako pewna wielkość fizyczna.
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Concept for interpretation and assessment of slide bearings operation in Diesel enfines in probabilistic approach
PublicationW artykule zaproponowano interpretację wartościującą działania, które (podobnie jak przedstawione w mechanice klasycznej działania Hamiltona i Maupertiusa oraz działanie wynikające ze zmiany pędu ciała) jest rozpatrywane jako wielkość fizyczna o jednostce miary zwanej''dżulosekundą''. Przedstawiono propozycję ilościowej interpretacji działania dowolnego poprzecznego łożyska ślizgowego, w którym zachodzą oddziaływania energetyczne...
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Modeling of hazards, consequences and risk for safety assessment of ships in damaged conditions in operation
PublicationPraca dotyczy problematyki związanej z modelowaniem zagrożeń, konsekwencji i ryzyka, w metodzie oceny bezpieczeństwa statków w stanie uszkodzonym. Metoda oparta jest na podejściu zorientowanym na ocenę zachowania się statku i ocenę ryzyka wypadku. Kolejne moduły metody dotyczą identyfikacji zagrożeń i scenariuszy wypadków oraz oceny i kontroli ryzyka. Ocenę ryzyka można przeprowadzić przy zastosowaniu elementów metodyki Przypadku...
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Probabilistic concept of defining the situations possible to occur during operation of floating docks
PublicationW artykule zasygnalizowana została możliwość oszacowania bezpieczeństwa doków pływajacych, w wyniku zastosowania teorii procesów semimarkowskich, zarówno w fazie projektowania jak też eksploatacji. Przedstawiono opis formalny sytuacji, jakie mogą zaistnieć podczas funkcjonowania (działania) doków pływających, zarówno budowlanych jak również remontowych. Wyróżniono takie sytuacje jak: normalna, skomplikowana, niebezpieczna, awaryjna...
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A concept of application of the technical state change models of devices inship operation process
PublicationPrzedstawiono warunki zastosowania modeli zmian stanu technicznego urządzeń siłowni okrętowej w trakcie eksploatacji statku, koncepcję prognozowania zasobu godzin pracy urządzeń w zmiennych warunkach pływania oraz planowania obsług profilaktycznych.
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Cascaded Buck Hybrid Interlink Converter for Multiple-Input / Multiple-Output Operation
PublicationThe provision of isolated- and non-isolated DC output voltages by Power electronics power-conditioning devices in the recent ‘green-energy-revolution’ era is on course. In this paper, a structure for multi-input multi-output(MIMO) DC–DC buck converter is proposed to generate output voltages of varying levels with fewer component-count. The DC output voltage of each of the constituting buck converters can be used independently or...
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EHV transmission lines wires location on line operation issues - case studies
PublicationTransmission lines towers construction affects the line parameters and influences on its operation in the future. Misguided design of the tower can lead to serious problems such as overvoltages, electric arc extinction difficulties, voltage asymmetry, resonance phenomena or increasing of magnetic field near the line. The paper points out those threats on example of 400 kV double circuit overhead transmission line with shunt reactors....
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THE PROBLEM OF THE CALCULATION OF THE FREQUENCY OF DIAGNOSTIC EXAMINATIONS BASED ON DEVICE’S PROPER OPERATION TIME
PublicationThe paper presents the proposal to apply the normal distribution to solve the problem of the frequency of diagnostic tests. Particular emphasis is placed on simplicity of the method. This method may be useful for the average user technical system. The method reduces the number of assumptions to a minimum. The results do not raise of serious doubts but they require verification of course.
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TEST METHOD FOR DETERMINING THE CHEMICAL EMISSIONS OF A MARINE DIESEL ENGINE EXHAUST IN OPERATION
PublicationThe article briefly describes the problem of air pollution caused by sea-going ships and the resulting restrictions on the emission of toxic and harmful chemical compounds in the exhaust of marine engines, introduced by the International Maritime Organization (IMO) under the International Convention for the Prevention of Sea Pollution from Ships (MARPOL 73/78). Such emissions provide a significant metrological problem, not only...
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Influence of Operation Conditions on Temperature Hazard of Lithium-Iron-Phosphate (LiFePO4) Cells
PublicationThe article presents and discusses the results of research on hazard, especially temperature, for selected lithium-ion-phosphate cells operated in accordance with the manufacturer’s recommendations but used under onerous mining conditions. This applies to the performance of cells in battery sets without the application of any management system (BMS). On the basis of the obtained test results, first of all, the influence of the...
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Selected information technology tools supporting for maintenance and operation management electrical grids
PublicationThe paper presents the main issues of management of electrical grids. Selected information technology tools supporting for electrical grids maintenance are presented. In electrical infrastructure maintenance of power companies the geographic information systems are increasingly used to support the management of theirs resources. Their functionalities in terms creating comprehensive databases for electrical infrastructure of power...
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Modelling of the Baumann turbine stage operation Part II. Free and kinetic vibrations
PublicationIn this paper has been presented a methodology of validation a novel mathematical model dedicated to evaluation and prediction of material degradation and demage of steam turbine elements such as blades, valves and pipes due to three mechanisms: stress-corosion, high-temperature creep and low-cyclic fatigue. The validation concept is based on an experimental setup manufactured in the Laboratory of Faculty of Mechanical and Power...
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Risk Diagnosis and Management with BBN for Civil Engineering Projects during Construction and Operation
PublicationThe authors demonstrate how expert knowledge about the construction and operation phases combined with monitoring data can be utilized for the diagnosis and management of risks typical to large civil engineering projects. The methodology chosen for estimating the probabilities of risk elements is known as Bayesian Belief Networks (BBN). Using a BBN model one can keep on updating the risk event probabilities as the new evidence...
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Five-phase Induction Motor Drive Operation During Stator Phase Fault
PublicationThe article presents the most important advantages of multi-phase electric drives. The construction of a five-phase squirrel cage induction motor together with possible stator winding distribution cases is presented, which affect the properties of such motor. Increased reliability of five-phase drives was indicated. The drive operation properties were confirmed by experimental results.
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Approach Manoeuvre During Emergency Ship-to-Ship Transfer Operation with Oil Spill
PublicationOne of the major activities during Ship to Ship (STS) transfer operation at sea is to safe approach the Ship to be Lightered (SBL) which moves on a constant heading with slow speed or drifting. In the paper described the manoeuvring problem for approaching during emergency STS transfer operation with oil spill. The approach manoeuvre is considered as a sequence of navigation manoeuvres in specific navigational environment with...
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OPERATION OF TWO-SHAFT GAS TURBINE IN THE RANGE OF OPEN ANTI-SURGE VALVE
PublicationThis paper presents experimental tests of full-scale two-shaft gas turbine in the range of open anti-surge valve (ASV). The tests were carried out in a laboratory gas- turbine test stand belonging to Department of Automation and Power Engineering , Faculty of Ocean Engineering and Ship Technology , Gdańsk University of Technology. The tests covered the start-up and low load operation of the turbine set in the range of open...
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Field Tests on Hydrodynamic and Hybrid Operation of a Bidirectional Thrust Bearing of a Pump-Turbine
PublicationIn vertical shaft pump turbines operating in pumped storage power plants an important role is played by a thrust bearing. Due to the bidirectional character of operation, thrust bearing tilting pads have to be supported symmetrically, which is known to be unfavourable from the point of view of their performance. Large thrust bearings have to be carefully designed so as to minimise excessive thermo-elastic pad deformations. The...
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A Note on Fractional Curl Operator
PublicationIn this letter, we demonstrate that the fractional curl operator, widely used in electromagnetics since 1998, is essentially a rotation operation of components of the complex Riemann–Silberstein vector representing the electromagnetic field. It occurs that after the wave decomposition into circular polarisations, the standard duality rotation with the angle depending on the fractional order is applied to the left-handed basis vector...
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Estimation of vehicle operational fuel consumption
PublicationW pracy przedstawiono metodę umożliwiającą wyznaczenie referencyjnego zużycia paliwa dla zarejestrowanych warunków eksploatacji. Warunki eksploatacji opisane są rozkładem energochłonności jednostkowej, która obejmuje zarówno wpływ warunków zewnętrznych jak również styl jazdy kierowcy. W pracy przedstawiono zestawienie wyników uzyskanych dla przejazdów wykonanych na terenie Gdańska, w regularnym ruchu miejskim. Przedstawiono także...
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Practice implementation of operational level agreement
PublicationThe paper concerns practical implementation of the Operational Level Agreement (OLA) compared to the Service Level Agreement (SLA).
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Polish- Russian Cooperation of Pomorskie Province
PublicationPolish-Russian Cooperation of Pomorskie Province commenced in 1999 and was based on the intergovernmental agreements. The new agreement, executed between the authorities of the Pomeranian Province and Kaliningrad Oblast in 2002, provided for cooperation in many areas. The contacts between the partners were dominated by economic cooperation. The Polish-Russian cooperation stopped with Polish accession to the Schengen zone. Cooperation...
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Barriers to inter-company cooperation in clusters
PublicationClusters have proved to be an important source of competitiveness for the economic development of regions within the European Union. One of the main goals of cluster development is to stimulate cooperation between companies in one or a few related sectors. The stakeholders of a cluster, as well as the local economy, can derive many benefits from such cooperation. However, there are numerous barriers, which make it difficult for...
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Towards the Development of a Risk Model for Unmanned Vessels Design and Operations
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Compact Scheduling In Open Shop With Zero-One Time Operations
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What Makes Bariatric Operations Difficult–Results of a National Survey
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Towards the Development of a Risk Model for Unmanned Vessels Design and Operations
PublicationAn unmanned merchant vessel seems to be escaping from the stage of idea exploration. Once the concept proofs its safety, it may become a part of maritime reality. Although the safety aspect of such a ship has been addressed by a handful of scholars, the problem remains open. This is mainly due to lack of knowledge regarding actual operational circumstances and design of unmanned ships, which are yet to be developed. In the...