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Wyniki wyszukiwania dla: SHIP DESIGN
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CTOD designation for WM and HAZ in butt joint made from S460 ML steel, Expertise No. WOiO/II/82/2015
PublikacjaTypical (normative) testing of materials and/or welded joints do not answer on all questions about material or welded joint properties. In ship building and off-shore sectors, many strucures requires materials and joint with higher than typical fatigue resistance. Imact tests, which are carried out during welding technology qualification, gives answer about ductility, CTOD tests results about material or welded joint ability to...
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Designate of CTOD for WM and HAZ, report no: WOiO/II/122/2014
PublikacjaTypical (normative) testing of materials and/or welded joints do not answer on all questions about material or welded joint properties. In ship building and off-shore sectors, many strucures requires materials and joint with higher than typical fatigue resistance. Imact tests, which are carried out during welding technology qualification, gives answer about ductility, CTOD tests results about material or welded joint ability to...
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Nondestructive corrosion degradation assessment based on asymmetry of guided wave propagation field
PublikacjaThe article presents the results of numerical and experimental investigation of guided wave propagation in steel plates subjected to corrosion degradation. The development of novel procedures allowing for the assessment of the corrosion degradation level is crucial in the effective diagnostics of offshore and ship structures that are especially subjected to aggressive environments. The study’s main aim is to investigate the influence...
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Analysis of Signalized Intersections in the Context of Pedestrian Traffic
PublikacjaGdynia is a city in the Pomeranian Voivod e ship of Poland with a population of about 250,000. It faces a growing motorization rate th at needs to be addressed. Car ownership in Gdynia now exceed s 500 vehicles per 1000 residents. Travel by public transport is decreasing and the rate of walking and cycling remains low. It is necessary to reverse these negative trends by implementing solu tions based...
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On the Use of Selected 4th Generation Nuclear Reactors in Marine Power Plants
PublikacjaThis article provides a review of the possibility of using different types of reactors to power ships. The analyses were carried out for three different large vessels: a container ship, a liquid gas carrier and a bulk carrier. A novelty of this work is the analysis of the proposal to adapt marine power plants to ecological requirements in shipping by replacing the conventional propulsion system based on internal combustion engines...
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EVALUATING THE INFLUENCE OF BENDING STRESS ON A 1H18N9 STEEL SHAFT WEAR PROCESS IN A WATER LUBRICATED SLIDING BEARING WITH A RUBBER BUSHING
PublikacjaThe issue of excessive wear of shaft journals co-working with a rubber bearing has been unexplained so far. Premature and sometimes very intensive wear of ship sliding bearings in water conditions is the reason for carry out very expensive and more frequent than expected repairs. The authors (E. Piątkowska, W. Litwin) made an attempt to find a case that influences the value of this wear described in the paper “Attempt at Evaluating...
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Development of a Response Assessment Tool for a Floating Dock System
PublikacjaDocking operations of ships require a response assessment to ensure structural and personnel safety. Environmental loads and improper ballast adjustments are the main threats to the docking operations. They can cause severe structural damages and stability loss to a floating dock system which includes a floating dock and a docked vessel, even if the velocities of the dock and the vessel are very low during the docking process....
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High resolution optical and acoustic remote sensing datasets of the Puck Lagoon
PublikacjaThe very shallow marine basin of Puck Lagoon in the southern Baltic Sea, on the Northern coast of Poland, hosts valuable benthic habitats and cultural heritage sites. These include, among others, protected Zostera marina meadows, one of the Baltic’s major medieval harbours, a ship graveyard, and likely other submerged features that are yet to be discovered. Prior to this project, no comprehensive high-resolution remote sensing...
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Towards a reliable method for extrapolation of propulsion performance for vessels with twin-crp-pod system
PublikacjaThe study presents power performance prediction of an Ultra Large Container Ship (ULCS) with hybrid twin-crp-pod propulsion system. Twin crp-pod propulsion system is a combination of three concepts: twin screw, contra-rotating propellers (crp) and conventional shaft propellers with pod propulsors behind. The presented study shows the current extrapolation method for crp propulsion systems and tries to point out its weaknesses....
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COMPARATIVE ANALYSIS OF RESULTS OF APPLICATION OF MARKOV AND SEMI-MARKOV PROCESSES TO RELIABILITY MODELS OF MULTI-STATE TECHNICAL OBJECTS
PublikacjaDuring rational operation of technical objects and systems various operational decisions are made and decision-making process itself should be consisted in selecting that considered most favourable out of all possible to be taken. Choice of such decision is possible after taking into account many different information items but it never be completely correct without accounting for data and indices dealing with reliability. In...
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Feasibility of combined diesel engine - steam turbine in power station operating in the maritime
PublikacjaCompression-ignition engines used in ship technology as main propulsion engines are large units reaching even to 50-60 MW. Currently, the efficiency of such engines amounts to 45-50%. With such a large power unit, exhaust gases leaving the engine contain very large quantities of heat available for further treatment. Exhaust gases from the piston engine contain about 25% of the heat supplied to the engine in the fuel. Using the...
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Understanding Fuel Saving and Clean Fuel Strategies Towards Green Maritime
PublikacjaDue to recent emission-associated regulations imposed on marine fuel, ship owners have been forced to seek alternate fuels, in order to meet the new limits. The aim of achieving low-carbon shipping by the year 2050, has meant that alternative marine fuels, as well as various technological and operational initiatives, need to be taken into account. This article evaluates and examines recent clean fuels and novel clean technologies...
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The retrofitting of ships by applying retractable bow hydrofoils: a case study
PublikacjaIncreasing environmental requirements and a relatively long ship life of 30 years mean more attention is needed to retrofit existing ships. One possibility is using hydrofoils to reduce the ship’s resistance and improve comfort and safety in rough sea conditions. This study investigates the influence of retractable bow hydrofoils on the seakeeping performance and operational conditions of a selected case study vessel (V-shaped...
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Selection of an artificial pre-training neural network for the classification of inland vessels based on their images
PublikacjaArtificial neural networks (ANN) are the most commonly used algorithms for image classification problems. An image classifier takes an image or video as input and classifies it into one of the possible categories that it was trained to identify. They are applied in various areas such as security, defense, healthcare, biology, forensics, communication, etc. There is no need to create one’s own ANN because there are several pre-trained...
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Energy Demand of Short-Range Inland Ferry with Series Hybrid Propulsion Depending on the Navigation Strategy
PublikacjaInterest in hybrid propulsion systems that can be used on small vessels has increased significantly in recent years. They can replace inefficient and environmentally burdensome conventional systems based on diesel engines. Hybrid propulsion has many advantages such as high energy efficiency and virtually noiseless operation, and therefore it fits well with the current trends of “green shipping” and “zero emission”. The aim of the...
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Application of the IMO standard manoeuvres procedure for pod-driven ships
PublikacjaInternational Maritime Organisation (IMO) in the resolution MSC.137(76) Standards for Ship manoeuvrability presents the manoeuvring criteria that has to be satisfied by majority of seagoing ships. Together with the criteria, procedures for carrying out the manoeuvring tests are also presented. They however do not correspond directly to ships with non-conventional steering-propulsion devices, like pod drives. IMO is aware of this...
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Feasibility Study on the Potential Using of Ferrocement for Constructing Floats
PublikacjaIn recent years, there has been a significant increase in interest in ferrocement as a material for various engineering constructions. Due to its ease of shaping complex forms, it has been used previously, for example, in constructing ship hulls or tank walls. Apart from the advantages associated with the ability to shape thin elements, improved mechanical properties compared to concrete, and resistance to chemical actions, ferrocement...
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The shallow sea experiment with usage of linear hydrophone array
PublikacjaPurpose of this article is to present designed and made linear hydrophone array and the results obtained during in situ trails on Gulf of Gdańsk. The measuring system allowed to localize hydrophones in the selected points and perform measurements in both the horizontal antenna positioning and vertical. Made in this way recordings allow creating accurate 3D imaging of sound intensity/propagation. During research three floating objects...
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Comparison of strain results at a laser weld notch obtained by numerical calculations and experimental measurements
PublikacjaIn the development of ship structures applying new materials and it’s purposeful placement play an important role. During the last years, especially in a construction of ro-ro type vessels, the usage of novel sandwich structures in cargo decks is profitable. Steel sandwich panel is an innovative solution which at a todays state of development can be used for the construction of any members not taking part in a global bending of...
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Application of semi-Markov processes for evaluation of diesel engines reliability with regards to diagnostics
PublikacjaThe paper presents semi-Markov models of technical state transitions for diesel engines, useful for determination of their reliability, as a result of the conducted statistical empirical studies. Interpretation of technical states provided for this sort of engines refers to ship main engines, i.e. engines employed in propulsion systems of sea-going ships. The considerations recognize diesel engine as a diagnosed system (SDN), of...
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Organotin Compounds: Environmental Fate and Analytics
PublikacjaFor more than 50 years, organotin compounds have been used in almost all sectors of industry. As a consequence, specific environmental compartments are affected by the emission of these xenobiotics. The emissions of organotin compounds into the environment from paints used in the shipbuilding industry for ship hull coating, and from the plant protection products are particularly significant.In 2001, the IMO introduced a global...
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Polymer journal bearings behaviour research under limited lubrication and cooling conditions conducted on high torque test rig
PublikacjaPolymer journal bearings are frequently used as a water-lubricated bearings of small marine units’ propeller shafts . Choice of these bearings is based on their simple construction and relatively low purchase and maintenance costs. Although properly designed and installed water lubricated bearings may well last for over a decade, rapid wear or failure of these bearings can be observed...
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Methodology for determining the elemental composition, as well as energy and ignition properties of the low-sulfur marine fuels
PublikacjaThe key metrological issue of substance and energy balance in research engines is the precise determination of the elemental composition of the applied fuel and its net calorific value. This makes it possible to calculate the amount of heat brought with the fuel into the combustion chamber, as well as the amount and gas composition of the exhaust. However, to fully assess the energy quality of the fuel used, its ignition properties...
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A risk comparison framework for autonomous ships navigation
PublikacjaMaritime autonomous surface ships (MASS) may operate in three predefined operational modes (OM): manual, remote, or autonomous control. Determining the appropriate OM for MASS is important for operators and competent authorities that monitor and regulate maritime traffic in given areas. However, a science-based approach to this respect is currently unavailable. To assist the selection of the proper OM, this study presents a risk-based...
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Raman investigation of the patina layers on Hungarian copper ingots from a fifteenth century shipwreck
PublikacjaWe report results of the patina study of underwater archeological finding ofmedieval copper objects performed by means of the Raman and complementary spectroscopic techniques. The objects were found submerged in the sea as cargo part of the ship which sunk in the Gulf of Gdańsk in 1408. The excavated collection consists of 230 oval ingots of the size and mass up to about 60 cm and 18 kg (total of 2 tons), respectively. In the Raman...
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The experimental identification of the dynamic coefficients of two hydrodynamic journal bearings operating at constant rotational speed and under nonlinear conditions.
PublikacjaHydrodynamic bearings are commonly used in ship propulsion systems. Typically, they are calculated using numerical or experimental methods. This paper presents an experimental study through which it has been possible to estimate 24 dynamic coefficients of two hydrodynamic slide bearings operating under nonlinear conditions. During the investigation, bearing mass coefficients are identified by means of a newly developed algorithm....
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Data-driven, probabilistic model for attainable speed for ships approaching Gdańsk harbour
PublikacjaThe growing demand for maritime transportation leads to increased traffic in ports. From this arises the need to observe the consequences of the specific speed ships reach when approaching seaports. However, usually the analyzed cases refer only to the statistical evaluation of the studied phenomenon or to the empirical modelling, ignoring the mutual influence of variables such as ship type, length or weather conditions. In this...
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Experimental and numerical identification of corrosion degradation of ageing structural components
PublikacjaThe study presents experimental and numerical identification of corrosion degradation of thin-walled structural components employing guided wave propagation. The steel structural components are subjected to through-thickness varying corrosion degradation levels. The developed approach using the non-destructive guided wave-propagation quantifies the equivalent average corrosion degradation level by exploring a limited number of...
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Indoor accelerated controlled corrosion degradation test of small- and large-scale specimens
PublikacjaThe work presented here is a part of a long-term project analysing the structural behaviour of ageing marine structures. An accelerated corrosion degradation set-up was developed to reproduce corroded marine structural specimens of different degrees of degradation, controlling various natural factors, i.e., temperature, oxygen content, salinity, and flow velocity. The nine stiffened plates of 1.2 m length and 30 small scale specimens...
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A Novel Approach of Using Selected Unconventional Geodesic Methods of Estimation on VTS Areas
PublikacjaThe Vessel Traffic Service (VTS) systems belong to the fundamental tools used in ensuring a high level of safety across sea basins with heavy traffic, where the presence of navigational hazards poses a great risk of collision or a ship running aground. In order to determine the mutual location of ships, VTS systems obtain information from different facilities, such as coastal radar stations, AIS, and vision systems. Fixing a ship’s...
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Post processing and selecting data obtain with parametric sub-bottom profiler SES-2000 Standard during sounding the Gulf of Gdansk
PublikacjaThe main goal of the paper is to describe the results of sounding the Gulf of Gdansk seabed using a parametric sub-bottom profiler SES-2000 Standard. Quality of obtained during trials data depends inter alia on proper location of antenna to reduce influence of pitch, roll, heave and ship noise (bubbles from propeller and a hull flow, vibration from main engine and peripheral devices). Furthermore calibration of complementary units...
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“Shadow” vs. “Phase 3D” method within endoscopic examinations of marine engines
PublikacjaA visual investigation of surfaces creating internal, working spaces of marine combustion engines by means of specialized view-finders so called endoscopes is at present almost a basic method of technical diag-nostics. The surface structure of constructional material is visible during investigations like through the magnifying glass (usually with a precisely determined magnification), which makes possible a detection, recognition...
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Fault diagnosis of marine 4-stroke diesel engines using a one-vs-one extreme learning ensemble
PublikacjaThis paper proposes a novel approach for intelligent fault diagnosis for stroke Diesel marine engines, which are commonly used in on-road and marine transportation. The safety and reliability of a ship's work rely strongly on the performance of such an engine; therefore, early detection of any type of failure that affects the engine is of crucial importance. Automatic diagnostic systems are of special importance because they can...
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Thermal efficiency investigations on the self-ignition test engine fed with marine low sulfur diesel fuels
PublikacjaWithin the article an issues of implementing the new kinds of marine diesel fuels into ships’ operation was described taking into ac-count restrictions on the permissible sulphur content introduced by the International Maritime Organization. This is a new situation for ship owners and fuel producers, which forces the necessity to carry out laboratory research tests on especially adapted engine stands. How to elaborate the method...
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ENERGY ANALYSIS OF THE PROPULSION SHAFT FATIGUE PROCESS IN A ROTATING MECHANICAL SYSTEM PART II IDENTIFICATION STUDIES – DEVELOPING THE FATIGUE DURABILITY MODEL OF A DRIVE SHAFT
PublikacjaThe article presents a continuation of research carried out concerning identification of energy consequences of mechanical fatigue within a propeller shaft in a rotating mechanical system, while working under conditions of the loss of the required alignment of shaft lines. Experimental research was carried out on a physical model reflecting a full-sized real object: i.e., the propulsion system of the ship. It is proven, by means...
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DETERMINATION OF SEAKEEPING PERFORMANCE FOR A CASE STUDY VESSEL BY THE STRIP THEORY METHOD
PublikacjaThe increase of seakeeping performance is of particular importance for car and passenger ferries, service ships in the gas and oil extraction industry and offshore wind power farm industry, as well as for special purpose ships (including military applications). In the water areas of the Baltic Sea, North Sea, and Mediterranean Sea, which are characterised by a short and steep wave, the hull shape has a substantial impact on the...
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Research on water lubricated main shaft bearings in conditions of improper lubrication and cooling conducted on high torque real-life scale bush test rig
PublikacjaWater lubricated polymer bushes find increasingly popular use in the sliding bearings of marine propellers, water turbines and pump shafts. Such popularity is partly due to their simple construction which also means relatively affordable price. In addition, properly designed and installed water lubricated bearings may well last for over a decade. However, in practical experience one may also observe cases of rapid wear...
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A Concept for Safe and Less Expensive Acceleration of a Marine Steam Turbine Start-up
PublikacjaThis paper analyses the issue of accelerated start-up of a marine steam turbine, which is an important problem because the start-up of a steam machine involves the combustion of fuel that is not transformed into useful energy. To find novel technologies that offer improvements in this aspect is essential due to restrictions on reducing ship emissions. Thus, the shorter the start-up time, the better for the environment and economy....
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Port Cities within Port Regions: Shaping Complex Urban Environments in Gdańsk Bay, Poland
PublikacjaPort cities located within various metropolitan or functional regions face very different development scenarios. This applies not only to entire municipalities but also to particular areas that play important roles in urban development—including ports as well as their specialized parts. This refers also to the various types of maritime industries, including the processing of goods, logistics operations, shipbuilding, or ship repairing,...
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Selected Aspects of 3D Printing for Emergency Replacement of Structural Elements
PublikacjaThe paper presents a synthetic characterization of modern methods of manufacturing or regenerating machine elements. Considered methods are machining and additive methods, in particular 3D printing in the FDM/FFF technique. For the study, the authors made samples of the holder bracket using selected methods. Samples made by machining operations, 3D printing with various filling were tested. The paper contains a technical and economic...
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Corrosion damage identification based on the symmetry of propagating wavefield measured by a circular array of piezoelectric transducers: Theoretical, experimental and numerical studies
PublikacjaThe article investigates the results obtained from numerical simulations and experimental tests concerning the propagation of guided waves in corroded steel plates. Developing innovative methodologies for assessing corrosion-induced degradation is crucial for accurately diagnosing offshore and ship structures exposed to harsh environmental conditions. The main aim of the research is to analyze how surface irregularities affect...
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Wykorzystanie algorytmu ewolucyjnego i logiki rozmytej do kierowania statkiem
PublikacjaRozwój technik komputerowych w ostatnich latach, wpłynął na zmiany w sposobie prowadzenia nawigacji na współczesnym statku floty handlowej. Dysponując doświadczeniami związanymi z zatonięciem promu ''Estonia'', pod pokładem którego życie utraciły 852 osoby (95 ciał odnaleziono, 757 uznano za zaginione) oraz innych jednostek morskich, opracowano Konwencję STCW-95 nakładającą na oficerów nawigacyjnych i personel pokładowy, obowiązek...
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An electric ring thruster as auxiliary manoeuvring propulsion system for watercraft - construction analysis
PublikacjaThe reported project aimed at examining properties and purposefulness of use of modern electromagneticbearings for a screw propeller in a prototype version of a synchronous ring motor with rare earths magnets.Bearings of this type generate electromagnetic forces which keep the rotor in a state of levitation. Therotating machine with magnetic bearings can work in any environment which reveals diamagnetic properties(air, vacuum,...
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Operation evaluation method for marine turbine combustion engines in terms of energetics
PublikacjaAn evaluation proposal (quantitative determination) of an y combustion turbine engine operation has been presented , wherein the impact energy occurs at a given time due to Energy conversion. The fact has been taken into account that in this type of internal combustion engines the energy conversion occurs first in the combustion chambers and in the spaces between the blade of the turbine engine. It was assumed that in the combustion...
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FAILURE OF MAGNETIC FLUID SEALS OPERATING IN WATER: PRELIMINARY CONCLUSIONS
PublikacjaThe article analyses properties of magnetic fluid seals installed in rotary sealing no des which operate in the utility water environment. Seals of this type have been examined as a possible solution to the problem with ship manoeuvring propulsion sealing. The present analysis bases on laboratory durability tests of magnetic fluid seals expo sed to long - term utility water loads, at different water pressures and shaft revolutions....
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IDENTIFICATION OF DAMAGES OF TRIBOLOGICAL ASSOCIATIONS IN CRANKSHAFT AND PISTON SYSTEMS OF TWO-STROKE INTERNAL COMBUSTION ENGINES USED AS MAIN PROPULSION IN SEA-GOING VESSELS AND PROPOSAL OF PROBABILISTIC DESCRIPTION OF LOADS AS CAUSES OF THESE DAMAGES
PublikacjaThe article discusses damages of essential tribological associations in crankshaft and piston systems of large power two-stroke engines used as main engines, which take place during transport tasks performed by those ships. Difficulties are named which make preventing those damages impossible, despite the fact that the technical state of engines of this type is identified with the aid of complex diagnostic systems making use of...
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Laboratory station for research of the innovative dry method of exhaust gas desulfurization for an engine powered with residual fuel
PublikacjaContemporary methods of exhaust gas desulfurization in marine engines are all expensive methods (4-5 million euro). This is, among other reasons, due to the limited market audience, but primarily due to the monop-olized position of manufacturers offering fabrication and assembly of this type of marine ship installations. Proposed as part of a research project financed by the Regional Fund for Environmental Protection and Maritime...
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An analytical four-layer horizontal electric current dipole model for analysing underwater electric potential in shallow seawater
PublikacjaThe paper presents a new analytical four‑layer (air–water–bottom–non‑conductive layer) horizontal electric dipole model which allows an accurate approximation of ship’s Underwater Electric Potential (UEP) from a sufficient depth in shallow coastal marine waters. The numerical methods, usually Finite Element Method (FEM) or Boundary Elements Method (BEM), are typically used to estimate the electric field and the distribution of...
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Nondestructive global corrosion measurement using guided wavefield data
PublikacjaMetallic structures often face degradation, and corrosion ranks among the most prevalent forms of deterioration. Accurate quantification of corrosion is crucial, especially for structures exposed to harsh environmental conditions, such as marine vessels and offshore installations. Because the traditional measurement methods based on scanning by ultrasonic gauge are time-consuming and provide only rough information on the thickness...
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A Comparative Study of Fuzzy SMC with Adaptive Fuzzy PID for Sensorless Speed Control of Six-Phase Induction Motor
PublikacjaMulti-phase motors have recently replaced three-phase induction motors in a variety of applications due to the numerous benefits they provide, and the absence of speed sensors promotes induction motors with variable speed drives. Sensorless speed control minimizes unnecessary speed encoder cost, reduces maintenance, and improves the motor drive’s reliability. The performance comparison of the fuzzy sliding mode controller (FSMC)...