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Wyniki wyszukiwania dla: PRESSURE SIGANTURE OF SHIP
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Structural Reliability Assessment Of Corroded Tanker Ship Based On Experimentally Estimated Ultimate Strength
PublikacjaThis work deals with the reliability assessment of a tanker ship hull structure subjected to a vertical bending moment and corrosion degradation. The progressive collapse and ultimate load carrying capacity are estimated based on experimentally tested scaled box-shaped-specimens. The translation of the strength estimate of the scaled specimen to the real tanker ship hull structure is performed based on the dimensional theory developing...
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Solutions of Power Electronics Converter for the Shore - to - Ship Power Systems
PublikacjaW artykule poruszono tematykę zasilania statków zacumowanych w porcie z lądowej sieci elektroenergetycznej poprzez wykorzystanie nowoczesnych konstrukcji przekształtników energoelektronicznych. Zaproponowano budowę sieci dystrybucyjnej prądu stałego, przewoźnej platformy zasilającej oraz zastosowanie zasobników energii
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Ship Dynamic Positioning Based on Nonlinear Model Predictive Control
PublikacjaThe presented work explores the simulation test results of using nonlinear model predictive control algorithm for ship dynamic positioning. In the optimization task, a goal function with a penalty was proposed with a variable prediction step. The results of the proposed control algorithm were compared with backstepping and PID. The effect of estimation accuracy on the control quality with the implemented algorithms was investigated....
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PROBLEMS OF EXPERIMENTAL DETERMINATION OF COEFFICIENTS OF THE WEAR OF SHIP PIPING SYSTEMS
PublikacjaThe article presents series of considerations relating to experimental evaluation of the reliability of ship piping systems. The aim of this study is to attempt to answer the following questions: What should be the tested element? How to choose the diameter of the tested item? What should be the result of measurements and calculations? How to measure? How to choose the duration of the test? How to choose the sample size and elaborate...
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Ship Evolutionary Trajectory Planning Method with Application of Polynomial Interpolation
PublikacjaPaper presents the application of evolutionary algorithms and polynomial interpolation in ship evolutionary trajectory planning method. Evolutionary algorithms allows to find a coIlision free trajectory in real time, while polynomial interpolation allows to model smooth trajectory which keeps continuity of velocity and acceleration values along path. Combination of this two methods allows to find trajectory, which under some assumptions,...
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Hydrothermal synthesis of vanadium ammonium compounds – the crucial role of the pressure
PublikacjaDue to the structural diversity and chemical activity, vanadium oxides and their derivatives are continuingly in the great interest of scientist. In a large family of vanadium compounds, one of the most interesting are ammonium vanadates (with the general formula (NH4)xVyOz). They have received much attention because of their promising application as cathode material in mono- and multivalent-ion batteries [1]. Hydrothermal synthesis...
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An Experimental Investigation of Pressure Wave Celerity During the Transient Slurry Flow
PublikacjaTransportation of slurries in pressure pipelines is an example of a complex flow due to specific parameters of transported medium. For practitioners, the economy of designing and maintenance is usually the most important factor. For this reason, most of hydrotransport installations are fairly simple; however, they become more vulnerable to negative effects of the transient flow which can occur in pressure pipelines. As the consequence,...
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A methodology for ultimate strength assessment of ship hull girder accounting for enhanced corrosion degradation modelling
PublikacjaThe presented work shows a methodology for the ultimate strength assessment of a ship hull, considering enhanced corrosion modelling. The approach is based on the classical Smith method. However, the recent findings regarding the impact of corrosion degradation on ultimate strength are incorporated. To this end, the stress–strain relationships for particular elements composing ship hull cross-section are modified using a specially...
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BLOOD PRESSURE ESTIMATION BY MEANS OF A JOINT IMPEDANCE– PHOTOPLETYSMOGRAPHIC METHOD
PublikacjaThe knowledge of patient’s day to day blood pressure changes is invaluable to physicians for both diagnostics and health monitoring reasons. Constant observation of the pressure throughout a day would provide even more valuable clinical information. A convenient non-invasive methods of blood pressure estimation for monitoring purposes are widely proposed. This work shows a statistical approach to...
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INFLUENCE OF LOAD AND INFLATION PRESSURE ON THE TYRE ROLLING RESISTANCE
PublikacjaTyre load and inflation pressure are important factors controlling rolling resistance of road vehicles. The article presents results obtained in the Technical University of Gdańsk during laboratory and road measurements of different car tyres rolling on different pavements. The knowledge of rolling resistance characteristics is important for modelling car dynamics as well as fuel consumption. It is also necessary to establish proper...
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A probabilistic-driven framework for enhanced corrosion estimation of ship structural components
PublikacjaThe work proposes a probabilistic-driven framework for enhanced corrosion estimation of ship structural components using Bayesian inference and limited measurement data. The new approach for modelling measurement uncertainty is proposed based on the results of previous corrosion tests that incorporate the non-uniform character of the corroded surface of structural components. The proposed framework's basic features are outlined,...
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Hybrid Expert System for Computer-Aided Design of Ship Thruster Subsystems
PublikacjaThe article presents an expert system supporting the design of ship's power subsystems, in particular the thruster subsystem. The proposed hybrid expert system uses the results of simulation tests as the additional source of knowledge. The results of system operation are collated in a report which can be used as part of ship design description. The work oriented on developing the expert system is the continuation of the research...
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A method to assess transverse vibration energy of ship propeller shaft for diagnostic purposes
PublikacjaThe article discusses a key problem of ship propulsion system vibration diagnostics, which concerns assessing this part of mechanical energy transmitted from the main engine to the ship propeller which is dissipated due to propeller shaft vibration. A simplified calculation model is proposed which allows the total energy of the generated torsional vibration to be assessed from the shaft deflection amplitude measured at the mind-span...
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Determination of Earth Pressure and Displacement of the Retaining Structure According to the Eurocode 7-1
PublikacjaComparative analysis of standard guidelines and findings given in EC7-1 and in Polish Standard PN-83/B-03010. Discussed guidelines concerning active and passive earth pressure as well as at rest pressure state. Wall displacement causing limit states of earth pressure and resistance. Interactive assumptions concerning intermediate earth pressure and resistance values. Conclusions and final remarks.
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Evolutionary Sets of Safe Ship Trajectories: problem dedicated operators
PublikacjaThe paper presents the optimization process of the evolutionary sets of safe ship trajectories method, with a focus on its problem-dedicated operators. The method utilizes a customized evolutionary algorithm to solve a constrained optimization problem. This problem is defined as finding a set of cooperating trajectories (a set is an evolutionary individual) of all the ships involved in the encounter situation. The resulting trajectories...
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The FEM analysis of pressure installation elements after simulated accidental overheating
PublikacjaThe paper presents innovative analysis focused on the safety aspects of existing pressure installation operation after overheating accidents. Results presented here can be applied in decision-making process concerning further operation of existing pressure installation after cooling system failure. In this paper the results of FEM analysis performed for a straight pipe and 90 degrees elbow, made of super duplex stainless steel,...
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Compensation of pressure peaks in pwk-type hydraulic pumps
Publikacjahydraulic axial pumps equipped with cam-driven commutation unit (pwk pumps) proved their high efficiency up to 55 mpa and ability to work self-sucking, even at high speed. displacement of pwk pump may easily be changed by moving its control cam. full discharge from hydrostatic forces makes such control possible by direct action of a low-energy actuator like proportional electromagnet or stepping motor. that eliminates heavy and...
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The accuracy of SpaceLabs 90207 in blood pressure monitoring in patients with atrial fibrillation
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The INTERSALT Study and the complex relationship between salt intake and blood pressure
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Blood Pressure celebrates 20 years of dedication to Nordic hypertension research
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Pressure drop of HFE7000 and HFE7100 during flow condensation in minichannels
PublikacjaAttention is focused on the issues of flow resistance and pressure drop of perspective refrigeration fluids during condensation in the two-phase flow in minichannels. The case of the flow through a cylindrical single channel of 2.3 mm inner diameter was carefully analyzed. Pressure drop tests have been performed in diabatic flow conditions. The effect of heat flux, mass flux, vapour quality and saturation temperature on the two-phase...
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Algorithms for Ship Movement Prediction for Location Data Compression
PublikacjaDue to safety reasons, the movement of ships on the sea, especially near the coast should be tracked, recorded and stored. However, the amount of vessels which trajectories should be tracked by authorized institutions, often in real time, is usually huge. What is more, many sources of vessels position data (radars, AIS) produces thousands of records describing route of each tracked object, but lots of that records are correlated...
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Can we rely on the pulse transit time - pressure relationship - models comparison
PublikacjaAn unobtrusive, noninvasive and continuous pressure measurement is invaluable however, still being under research and development. There are many attempts proposing an appropriate relationship between pulse pressure velocity and pressure. Fifteen different formulas, both theoretical and experimental, describing relation between blood pressure and crosssectional area of the vessel were examined. Using these formulas the relation...
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Pressure effects on the superconductivity of the HfPd2Al Heusler compound: Experimental and theoretical study
PublikacjaPolycrystalline HfPd2Al has been synthesized using the arc-melting method and studied under ambient-pressure conditions by x-ray diffraction from room temperature up to 450 °C. High-pressure x-ray diffraction up to 23 GPa was also performed using Diacell-type membrane diamond anvil cells. The estimated linear thermal expansion coefficient was found to be α=1.40(3)×10−5K−1, and the bulk modulus derived from the fit to the third-order...
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The Impact of Sloshing Liquids on Ship Stability for Various Dimensions of Partly Filled Tanks
PublikacjaLiquid sloshing phenomenon taking place in partly filled ships' tanks directly affects the stability of a vessel. However, only static calculations are carried out onboard ships nowadays and static transfer of liquid weight is taken into account in the course of routine stability calculation. The paper is focused on a dynamic heeling moment due to liquid sloshing in tanks onboard ships. A number of numerical simulations of liquid...
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A Meta-Analysis of Pulse Arrival Time Based Blood Pressure Estimation
PublikacjaThe paper presents a preliminary meta-analysis of the sample correlation between pulse arrival time (PAT) and blood pressure (BP). The aim of the study was to verify sample correlation coefficient between PAT and BP using an affine model BP = a · P AT + b for systolic and diastolic blood pressure. The databases included in the search were the IEEE Xplore Digital Library, Springer Link and Google Scholar. Only papers from 2005 to...
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Dynamically positioned ship steering making use of backstepping method and artificial neural networks
PublikacjaThe article discusses the issue of designing a dynamic ship positioning system making use of the adaptive vectorial backstepping method and RBF type arti cial neural networks. In the article, the backstepping controller is used to determine control laws and neural network weight adaptation laws. e arti cial neural network is applied at each time instant to approximate nonlinear functions containing parametric uncertainties....
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Evolutionary Sets of Cooperating Ship Trajectories: COLREGS Compliance
PublikacjaThe paper presents a newly designed improvement to the method of solving multi-ship encounter situations. In general, the method combines some of the assumptions of game theory with evolutionary programming and aims to find optimal set of cooperating trajectories of all ships involved in an encounter situation. The improvement presented here is a new way of modelling some of the COLREGS rules. Due to this change, the method is...
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The sensitivity of bacteria to heavy metals in presence of mineral ship motor oil in coastal marine sediments and waters.
PublikacjaThe sensitivity of bacteria, isolated from coastal marine sediments and waters of Sopot beach, Gdańsk Bay (Poland), to heavy metals in the presence of mineral ship motor oil were studied. All isolated heterotrophic bacteria were resistant to the 0.1 mM lead concentration occurring in the environment. Metal resistance of bacteria isolated from coastal water was strongly related to mineral ship motor oil concentration. At 0.1% mineral...
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Analysis of the Possibilities of Applying 3D Print Methods for the Needs of Ship-Building Industry
PublikacjaArticle presents the analysis of applying additive and hybrid manufacturing methods and its impact on dynamic stiffness of prepared samples. Dynamic analysis of the handle bracket specimens consisted in plotting the resonance curves and using these curves to estimate the dynamic stiffness of elements produced with additive manufacturing technology. Authors focused especially on 3D print in Fused Deposiotion Modeling/Fused Filament...
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Topological Model of an Electromagnetic Environment Inside a Ship for Electromagnetic Compatibility (EMC) Analysis
PublikacjaThe mutual electromagnetic (EM) interactions between electrical and electronic devices in a segmented space, such as a ship's environment, ared described. Firstly, the topological structure of a ship's segmented internal environment, which consists of many electrical screening walls (shielding planes), is presented. Then, taking into account the ship's topological structure, a general description of the EM disturbance distribution,...
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Ship weather routing optimization with dynamic constraints based on reliable synchronous roll prediction
PublikacjaShip routing process taking into account weather conditions is a constrained multi-objective optimization problem and it should consider various optimization criteria and constraints. Formulation of a stability-related, dynamic route optimization constraint is presented in this paper. One of the key objectives of a cross ocean sailing is finding a compromise between ship safety and economics of operation. This compromise should...
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A ship domain-based model of collision risk for near-miss detection and Collision Alert Systems
PublikacjaThe paper presents a new model of ship collision risk, which utilises a ship domain concept and the related domain-based collision risk parameters. An encounter is here described by five variables representing: degree of domain violation (DDV), relative speed of the two vessels, combination of the vessels’ courses, arena violations and encounter complexity. As for the first three variables, their values can be directly computed...
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A multiparameter simulation-driven analysis of ship turning trajectory concerning a required number of irregular wave realizations
PublikacjaIn times of progressive automation of the marine industry, accurate modeling of ship maneuvers is of utmost importance to all parties involved in maritime transportation. Despite the existence of modern collisionavoidance algorithms using 6DOF motion models to predict ship trajectories in waves, the impact of stochastic realization of irregular waves is usually neglected and remains under-investigated. Therefore, herein, this phenomenon...
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Fatigue of the ship structure.
PublikacjaZaprezentowano wyniki prac badawczych zachowania paneli SANDWICH pod obciążeniem zginającym. Prace prowadzone były w Kat. Technol. Okrętów i Obiektów Oceanotechn. Wydz. OiO i obejmowały między innymi badania konstrukcji w skali rzeczywistej. Dokonano porównania uzyskanych rezultatów z wynikami prezentowanymi w literaturze.
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A tetragonal polymorph of SrMn2P2 made under high pressure – theory and experiment in harmony
PublikacjaFollowing the predictions of total energy calculations, a tetragonal SrMn2P2 phase is proposed and successfully formed under high pressure. At ambient pressure, SrMn2P2 adopts the primitive trigonal La2O3 structure type (space group P[3 with combining macron]m1). However, the results of total energy calculations indicate that SrMn2P2 should be more stable in the tetragonal ThCr2Si2 structure type (space group I4/mmm) than in its...
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The Conception of Decision-Making Support System for ComplexEnergetic System on Example of Ship Propulsion System
PublikacjaIn paper, the conception of decision-making support system for complex energetic system on example of ship propulsion system has been presented. Diversity of conditions, information overload and very often contradiction of decision-making criteria and time constraints result in difficulties in making right (rational) decision without using more or less expanded information processing systems (eg. database systems, expert systems,...
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Path planning algorithm for ship collisions avoidance in environment with changing strategy of dynamic obstacles
PublikacjaIn this paper a path planning algorithm for the ship collision avoidance is presented. Tested algorithm is used to determine close to optimal ship paths taking into account changing strategy of dynamic obstacles. For this purpose a path planning problem is defined. A specific structure of the individual path and fitness function is presented. Principle of operation of evolutionary algorithm and based on it dedicated application...
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Investigation method and mathematical model of pressure losses in hydraulic rotary motor
PublikacjaTis paper presents a way of determining the coefcient k of the pressure losses Δp (fow drag) in internal ducts 8 Mp of SWSB-63 hydraulic motor. Te coefcient is determined at a fow rate equal to the theoretical capacity Q of the Pt pump feeding the motor , the losses are related to the nominal pressure p in the hydraulic system. Te investigations n followed a model of energy performance of hydraulic rotary motor, proposed by...
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Simulation of ship spiral test for ballast and full load conditions
Dane BadawczeThe data show the results of the spiral test for the simplified ship model, taking into account two states of loading: ballast and full load. The data set contains the results of time simulation for sea state 10 on the Beaufort scale: changes in rudder angle delta_tab[deg]; angular velocity r_tab[deg/s]; surge velocity u_tab (m/s); sway velocity v_tab...
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Comparative analysis of thermodynamic cycles of selected nuclear ship power plants with high-temperature helium-cooled nuclear reactor
PublikacjaThis paper presents a comparative analysis of thermodynamic cycles of two ship power plant systems with a high-temperature helium- cooled nuclear reactor. The first of them is a gas system with recuperator , in which classical gas chamber is substituted for a HTGR reactor (High Temperature Gas-cooled Reactor) . The second of the considered cycles is a combined gas-steam system where working medium flux from gas turbine outlet...
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A method of determining and visualizing safe motion parameters of a ship navigating in restricted waters
PublikacjaThe paper presents a method of displaying ship collision avoidance information which is based on an unconventional Collision Threat Parameters Area (CTPA) technique. The solution presented here extends CTPA's functionality from past works by supporting navigation in restricted waters and handling ship domains analytically instead of numerically. It visualizes potential navigational threats as well as possible collision avoidance...
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Challenges in oscillometric blood pressure measurement in atrial fibrillation: looking for practical solutions
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More is Less? Optimal Combination Therapy for Adequate Blood Pressure Lowering in Hypertension
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Influence of preprocessing techniques on pulse pressure velocity determination
PublikacjaPulse Wave Velocity (PWV) is measured and utilized in many clinical applications. Recently, a wide research has been led to develop a cuff-less and continuous blood pressure method basing on PWV. However, in this application a decision on choosing an appropriate fiducial point of pulse wave (PW) waveform is necessary and substantial. It would allow to measure time parameters necessary to determine PWV. An influence of sampling...
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Some aspects of noise generated by a small ship in the shallow sea
PublikacjaThe passing and underwater moving objects produce the noises of variable intensity, which significantly increase the overall level of noise in the sea. This applies to both the sonic and ultrasonic range. The excessive levels of underwater noise adversely affects the so-called underwater acoustic climate and is the reason why this phenomenon is intensively investigated from the number of years. The results of experimental work...
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Influence of Properties of Hydraulic Fluid on Pressure Peaks in Axial Piston Pumps’ Chambers
PublikacjaThe article concentrates on the research of the pressure peaks in a working chamber of an axial piston pump. The main focus of the article is the influence of fluid properties on the pressure peaks value. Experimental and analytical methods were used to determine the impact of the fluid density, viscosity, compressibility and aeration. The article describes the pressure peak generation process and explains the theoretical basis...
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The influence of the geographic positioning system error on the quality of ship magnetic signature reproduction based on measurements in sea conditions
PublikacjaIn previous studies, the authors performed the magnetic signature reconstruction of the marine ship Zodiak as part of the measurement campaign focused on recording magnetic data and the relative position of a ship during its passage over a magnetometer immersed on the testing ground. A high degree of representation of the magnetic signature was obtained. However, the recorded measurement data revealed new patterns of the multidipole model...
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Analysis of hydrodynamic pressure fields of motorboats and pontoons in shallow water
PublikacjaThe article presents the results of calculations of the pressure fields generated by a motorboat at the bottom of a shallow sea. Calculations were made using the boundary elements method (BEM), arranged on the surface of the boat and the bottom of the sea. This method is described in [3], and applied on a free surface linearized boundary condition. Results for four different lengths of motorboats, from 2.85 m to 9.5 m, sea depth...
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Determining and visualizing safe motion parameters of a ship navigating in severe weather conditions
PublikacjaThe paper presents a method of determining, organizing and displaying ship collision avoidance information, which is based on the Collision Threat Parameters Area (CTPA) technique. The method makes it possible to visualize navigational threats as well as possible collision avoidance manoeuvres. The solution is focused on supporting navigation in severe weather conditions. Normally collision avoidance decisions are made taking into...