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Search results for: SHIPS OPERATION, SHIP RESONANT ROLLING, DANGEROUS ZONES, METACENTRIC HEIGHT (GM), ROLLING, NATURAL FREQUENCY OF ROLL, DYNAMIC STABILITY, SHIP STABILITY
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Digital processing of pulse signal from light-to-frequency converter under dynamic condition
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Problems with microprocessor voltage-to-frequency and frequency-to-voltage converters implementation
PublicationThe article presents the problems of digital voltage-to-frequency and frequency-to-voltage processing. Transducer systems implemented in microprocessor technology are presented, the timing of signals and functioning algorithms are discussed. An analysis of processing errors has been performed and the results of experimental studies of realized systems are presented.
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Preparation, morphology and properties of natural rubber composites filled with untreated short jute fibres
PublicationGreen composites were obtained by incorporation of short jute fibres in natural rubber matrix using a laboratory two-roll mill. The influence of untreated fibre content (1, 2.5, 5, 7.5 and 10 phr) on the mechanical properties, dynamic mechanical properties, swelling properties was examined. The behaviour of prepared green composites under cyclic compression was also investigated. Fibre dispersion in rubber matrix was studied by...
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A predictive estimation based control strategy for a quasi-resonant dc-link inverter
PublicationIn this paper the predictive estimation based control strategy for a quasi-resonant dc link inverter (PQRDCLI) is developed. Instead of direct measurement of dc link input inverter current – its estimation with one step prediction is applied. The PQRDCLI fed induction motor, controlled with a predictive current estimation stabilized inverter output voltage slopes independently of load. Moreover, reduction of overvoltage spikes...
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Residual Current Devices: Selection, Operation, and Testing
PublicationIn this book, the idea for residual current protection has been presented. The evolution in construction types of residual current devices, which has taken place over decades, is discussed. Types and functional properties of the contemporary residual current devices are described. The main parameters of these devices, from the point of view of their selection and application, are indicated. Special constructions of the protective...
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Determination of the dynamic critical maneuvering area in an encounter between two vessels: Operation with negligible environmental disruption
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Lubricant property and rolling contact fatigue test of oil-in-water emulsion type HFA-E and oil Total Azolla 46 as working liquids in hydraulic systems
PublicationW artykule scharakteryzowano i opisano wyniki badań własności smarnych wody destylowanej, emulsji wodno-olejowej typu HFA-E (1% oleju w wodzie) sporządzonej na bazie koncentratu Isosynth VX110BF, oleju Total Azolla 46 i samego koncentratu Isosynth VX110BF (tylko dla porównania z olejem, emulsją i wodą). W artykule pokazano wyniki badań pittingu z użyciem wody, emulsji i oleju jako środków smarnych. Ponadto w artykule przedstawiono...
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On possible lowering fuel oil consumption by differentiating loads on ship diesel engines running in parrallel.
PublicationPodano możliwości zmniejszenia zużycia paliwa przez silniki okrętowe pracujące równolegle dzieki różnicowaniu ich obciążeń eksploatacyjnych. Zaprezentowano podstawy teoretyczne oraz sposób postępowania przy pomiarach zużycia paliwa w czasie rzeczywistym.
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Conception of selecting reliability models for taking operating decisionsrelated to sea-going ship´s systems
PublicationPrzedstawiono 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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A Fuzzy Event Tree Model for Accident Scenario Analysis of Ship Stuck in Ice in Arctic Waters
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A concept of pusher - barge coupling device of two-segment ship for inland waterways and coastal service
PublicationW artykule przedstawiono założenia projektowe i koncepcję rozwiązania konstrukcyjnego oraz napędu i sterowania urządzenia sprzęgającego pchacz i barkę dwusegmentowego statku śródlądowego i przybrzeżnego. Zaprezentowane urządzenie umożliwia zarówno sztywne połączenie, jak i wzajemne kontrolowane wychylanie obu segmentów względem siebie, co w znacznym stopni zwiększa manewrowość, a tym samym bezpieczeństwo żeglugi, zwłaszcza na wąskich...
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Design concepts of propulsion and steering system for hotel unit of two-segment inland waterways ship
PublicationW artykule przedstawiono założenia projektowe i dwa rozwiązania koncepcyjne napędu i sterowania barki hotelowej, stanowiącej część dwusegmentowego statku śródlądowego i przybrzeżnego. Obydwa rozwiązania oparto na zastosowaniu dziobowego śrubosteru małej mocy, ze śrubą stałą umieszczoną w dyszy obrotowej. W jednym z rozwiązań śruba napędzana jest silnikiem hydraulicznym, zaś w drugim - silnikiem elektrycznym. Mechanizm obrotu kolumny...
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A Method of Risk and Safety Assessment During the Ship Salvage Using the Hazard, Release and Consequence Analysis
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Analysis and Experimental Verification of Improving the EEDI of a Ship using a Thruster Supplied by a Hybrid Power System
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Numerical Analysis of the Unsteady Propeller Performance in the Ship Wake Modified by Different Wake Improvement Devices
PublicationThe paper presents summary of numerical analysis of the unsteady propeller forces and induced pressure pulses generated by the selected real propeller of 7000 tons product tanker, operating in five different wakefields including four inflenced by the different wake improvement devices. The results of the analysis are partly compared with experimental data and univocal conclusions about the optimum wake improvement device are presented.
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The system combined of low-speed marine diesel engine and steam turbine in ship propulsion applications
PublicationPrzedstawiono koncepcje okrętowego układu kombinowanego silnik wolnoobrotowy tłokowy- turbina parowa, wykorzystującego ciepło zawarte w spalinach wylotowych.Porównano układ kombinowany dużej mocy dla dwóch silników tłokowych porównywalnych mocy z punktu widzenia termodynamicznego.
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Computational model for simulation of lifeboat motions during its launching from ship in rough seas
PublicationW artykule przedstawiono model obliczeniowy 3 D, opisujący ruch obiektu w 6 stopniach swobody (6DoF), do symulacji ruchu jedno- lub dwuzawiesiowej łodzi ratunkowej lub ratowniczej podczas opuszczania ze statku na wzburzonej wodzie. Jest to złożony model uwzględniający warunki morskie oraz elastyczność i własności tłumiące elementów i mechanizmów żurawika, liny oraz kadłuba łodzi. Ponadto przedstawiono przykładowe wyniki obliczeń...
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An integrated hydraulic drive system of a novel device for launching lifeboats from large passenger ship
PublicationArtykuł przedstawia zintegrowany układ napędu i sterowania hydraulicznego systemu ewakuacyjnego składającego się z wyciągu łańcuchowego z zamocowanymi na nim łodziami ratunkowymi oraz furto-rampy rufowej. Zastosowana tu furto-rampa z elementem wypornościowym umożliwia zwiększenie jej funkcji do samoczynnego dostosowania kąta jej wychylenia roboczego w przypadku znacznego przegłębienia statku na dziób. Przedstawiony układ hydrauliczny...
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CAUSALITY IN MODELS OF THERMAL PROCESSES IN SHIP ENGINE ROOMS WITH THE USE OF BOND GRAPH (BG) METHOD
PublicationWith a single approach to modeling elements of different physical nature, the method of Bond Graph (BG) is particularly well suited for modeling energy systems consisting of mechanical, thermal, electrical and hydraulic elements that operate in the power system engine room. The paper refers to the earlier presented new concept of thermal process modeling using the BG method. The authors own suggestions for determining causality...
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Influence of cathodic-protection-induced hydrogenation on mechanical properties of two ship hull plate steels
PublicationPrzedstawiono wyniki próby rozciągania i udarowej Charpy V dla stali zwykłej wytrzymałości (kategorii A) i podwyższonej wytrzymałości (kat. AH32) zarówno w stanie dostawy jak i po nawodorowaniu (protektor Zn w słonej wodzie). Nawodorowanie obydwu stali zwiększyło nieco granicę plastyczności (Re) i wydłużenie (A), nie zmieniając (atal A) lub nieco zmniejszając przewężenie (Z). Wpływ nawodorowania na udarność był ewidentnie pozytywny...
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Problem of optimal load distribution between generators minimizing risk of enegretic ship system overload.
PublicationOmówiono system rozdziału mocy czynnych pomiędzy generatorami w systemie energetycznym statku. Minimalizuje się ryzyko przeciążeń systemu przy jednoczesnej minimalizacji kosztów wytwarzania energii w systemie.
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The application of an expert system for simulation investigations in yhe aided design of ship power systems automation.
PublicationPrzedstawiono strukturę i funkcje systemu wspomagającego projektowanie automatyki systemów enegretycznych statków. Dane opisujące projektowany podsystem energetyczny są wprowadzane w trybie interaktywnym do systemu ekspertowego. Reguły określaja poprawność formalną i merytoryczną wprowadzonych danych. W przypadku braku błędów system automatycznie tworzy model symulacyjny projektowanego podsystemu enegretycznego i wywołuje program...
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Slow-wave resonant structures in branch-line coupler miniaturization: a case study
PublicationA case study of novel slow-wave resonant structures dedicated to efficient microstrip branch-line coupler size reduction has been presented. A compact 3-dB branch-line coupler has been designed to mimic the performance of its conventional counterpart, simultaneously demonstrating a substantial 88% surface area reduction. The vital usefulness of the approach in the process of microstrip line abbreviation has been experimentally...
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Variations of Ship’s Deck Elevation Due to Stochastic Process of Containers Loading
PublicationThe stochastic process of container loading is described in the paper with special emphasis to ship motion when she is lying at a quay. The 3 DOF system was applied to describe rolling, pitching and heaving of a vessel which may cause a significant variations of momentary deck elevation. The realistic range of such variations are assessed for a variety of cargo locations on-board and a phase shift between two independent gantries...
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Emulsifying blends based on natural fats for eco-design of O/W emulsions
PublicationEmulsifier blends are most often used to stabilize and modulate the properties of cosmetic and pharmaceutical emulsions, such as skin care or application-related consistency. However, the rational design of such emulsifier blends is often not well understood, especially when their ingredients are natural raw materials. This study aimed to analyze the influence of natural fatty ingredients selected as emulsifiers on the emulsion...
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Dangerous sound event recognition using Support Vector Machine classifiers
PublicationA method of recognizing events connected to danger based on their acoustic representation through Support Vector Machine classification is presented. The method proposed is particularly useful in an automatic surveillance system. The set of 28 parameters used in the classifier consists of dedicated parameters and MPEG-7 features. Methods for parameter calculation are presented, as well as a design of SVM model used for classification....
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Resonant DC link inverters for AC motor drive systems – critical evaluation
PublicationIn this survey paper, resonant and quasiresonant DC link inverters are reexamined for AC motor drive applications. Critical evaluation of representative topologies is based on simulation and waveform analysis to characterize current/voltage stress of components, control timing constraints and feasibility. A special concern over inverter common-mode voltage and voltage gradient du/dt limitation capacity is discussed for motor bearing...
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Modeling of a Quasi-Resonant DC Link Inverter Dedicated to Common-Mode Voltage and Ground Current Reduction
PublicationIn this paper, the modeling methodology of the AC drive system with a Parallel Quasi-Resonant DC Link Inverter (PQRDCLI) is described. A presented modeling approach is an attractive tool used for the effective evaluation of a common-mode (CM) voltage and grounds current reduction methods. Designed models of inverter, induction machine (IM), and cable are simple, thus the methods for parameter extraction are not complicated. Verification...
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Reliability and types of diagnosis in the process of diesel engine operation
PublicationThe article presents complexity of the problem concerning development of diagnosis with defined reliability by a diagnosing system (SDG) on technical condition of marine combustion engines, especially main engines. It was shown that development of the final diagnosis, the so-called initial operation diagnosis, on the operational usability (fDG on PEx) of a main engine in particular, is not possible without prior development of...
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Effect of power frequency on the stress state of disc actuator
PublicationThis paper presents the concept of determining the optimum frequency of coil supply in inductive-dynamic drive. As a criterion to obtain the sought frequency, the smallest value of reduced stress in the disc was assumed while maintaining the desired dynamics. The disc stress is determined on the basis of solution of vibrating thin plate equation. Magnetic pressure acting on the disc is obtained from a hybrid circumferentially-field...
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Automatic Identification System (AIS) Dynamic Data Integrity Monitoring and Trajectory Tracking Based on the Simultaneous Localization and Mapping (SLAM) Process Model
PublicationTo enhance the safety of marine navigation, one needs to consider the involvement of the automatic identification system (AIS), an existing system designed for ship-to-ship and shipto- shore communication. Previous research on the quality of AIS parameters revealed problems that the system experiences with sensor data exchange. In coastal areas, littoral AIS does not meet the expectations of operational continuity and system availability,...
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Thermal degradation of polylactic acid (PLA)/polyhydroxybutyrate (PHB) blends: A systematic review
PublicationPolylactic acid (PLA) and polyhydroxybutyrate (PHB) are two biopolyesters obtained from renewable resources like corn or sugar under bacterial fermentation. PLA is the most widely used biopolymer in diverse applications. Addition of PHB to PLA can improves the crystallinity of PLA, and thereby its mechanical strength. However, both PLA and PHB suffer from poor thermal stability, which limits their potential industrial application....
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Novel topology of compact coplanar waveguide resonant cell low-pass filter
PublicationIn this study, a novel pseudoelliptic function low-pass filter (LPF) constituted by a compact coplanar waveguide resonant cell has been designed and manufactured. The lumped-element seven-pole prototype has been adequately realized by using complementary perturbations located both in signal line and ground plane metallization. The fabricated uniplanar LPF offers a compact size of 5.6 x 9.8 mm2, return loss better than 26 dB over...
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Substrate Integrated Waveguide-Based Frequency-Tunable Self-Octaplexing Antenna
PublicationThis communication presents the first-ever substrate integrated waveguide (SIW)-based frequency-tunable self-octaplexing antenna (SOA) for wireless communication. The structure is arranged by implementing eight distinct patches with planar 50-ohm feedlines at the top of the SIW cavity, which realize eight distinct resonant frequencies. Independent tuning of each resonant frequency is achieved by incorporating appropriately allocated...
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Accurate design of pseudoelliptic inline SIW filters with frequency-dependent couplings
PublicationThis paper presents an accurate synthesis method for inline SIW (Substrate Integrated Waveguide) generalized Chebyshev bandpass filters with frequency-dependent couplings. The technique is based on the synthesis of a coupling matrix that takes into account the impedance of the frequency-dependent stub. Thus, a loading effect compensation in adjacent resonators (via resonant frequency adjustment) and coupling elements (via coupling-value...
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The semi-Markov model of energy state changes of the main marine internal combustion engine and method for evaluating its operation during ships voyage
PublicationPrzedstawiono metodę oceny działania tłokowych silników spalinowych napędu głównego statków morskich, nazywanych silnikami głównymi, działających w różnych warunkach ich eksploatacji. Metoda ta umożliwia obliczenie wartości działania w wyniku zastosowania teorii procesów semimarkowskich i statystyki matematycznej. Znamienne jest to, że działanie wspomnianych silników spalinowych zostało przyrównane do wielkości fizycznej, którą...
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Selected dynamic properties of adaptive proportional observer of induction motor state variables
PublicationThis paper presents problems related to the design and the stability of adaptive proportional observer which is used for estimation of magnetic flux and motor speed in sensorless control systems of induction motor. The gain matrix of the observer was chosen by genetic algorithm and alternatively by pole placement method. It has been shown that adaptive proportional observer is stable if the...
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Stability analysis of the internal cylindrical shell wall of a vertical double shell tank under a water test.
PublicationPrzedstawiono analizę zagrożenia stateczności lokalnej płaszcza wewnętrznego przy różnicy poziomów wody w zbiorniku wewnętrznym i przestrzeni międzypłaszczowej podczas próby wodnej zbiornika. Podano krytyczne różnice poziomów wody dla typowych zbiorników o pojemności od 10 000 do 100 000 m3.
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DSC and thermal stability investigation of novel poly(ester-ether) glycolsand poly(ester-ether)urethanes.
PublicationOtrzymano serie nowych poli(estro-etero)dioli z kwasu adypinowgo.........
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Analysis of the internal shell stability of the cylindrical vertical double-shell tank under the condition of the hydrostatic test
PublicationUtrata stateczności płaszcza wewnętrznego w pionowym stalowym zbiorniku może wystąpić jeżeli podczas próby wodnej słup wody w przestrzeni międzypłaszczowej będzie miał większą wysokość niż w zbiorniku wewnętrznym. W artykule przeprowadzono analizę jaka różnica poziomów wody podczas próby wodnej może zagrażać stateczności płaszcza wewnętrznego w zbiorniku o pojemności od 10000 m3 do 100000 m3.
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Thermal Barrier Stability and Wear Behavior of CVD Deposited Aluminide Coatings for MAR 247 Nickel Superalloy
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The effect of CeO2 on the thermal stability, structure and thermoluminescence and optically stimulated luminescence properties of barium borate glass
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The IP vs. VDE competition as a key factor determining the stability of the MgBX5 (X = F, Cl) compounds
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Numerical analysis of influence of intermediate stiffeners setting on the stability behaviour of thin-walled steel tank shell
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A facile preparation method and proof of cycle-stability of carbon-coated metal oxide and disulfide battery materials
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Tailoring the Stability of Ti-Doped Sr2Fe1.4TixMo0.6−xO6−δ Electrode Materials for Solid Oxide Fuel Cells
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Simultaneously improving the thermal stability, flame retardancy and mechanical properties of polyethylene by the combination of graphene with carbon black
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Effect of metal ions from Ginkgo biloba extracts on the oxidative stability of rapeseed oil and its triacylglycerols
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Investigating the Effect of Aluminum Diethylphosphinate on Thermal Stability, Flame Retardancy, and Mechanical Properties of Poly(butylene succinate)
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Effect of osmolytes on the thermal stability of proteins: replica exchange simulations of Trp-cage in urea and betaine solutions
PublicationAlthough osmolytes are known to modulate the folding equilibrium, the molecular mechanism of their effect on thermal denaturation of proteins is still poorly understood. Here, we simulated the thermal denaturation of a small model protein (Trp-cage) in the presence of denaturing (urea) and stabilizing (betaine) osmolytes, using the all-atom replica exchange molecular dynamics simulations. We found that urea destabilizes Trp-cage...