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Wyniki wyszukiwania dla: SYSTEMS OF SURFACE AND UNDERWATER OBSERVATION
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Determination of t8/5 cooling times for underwater local dry welding of steel
PublikacjaKnowledge of thermal history is the basic condition for studying the structure - properties of welded joints. The determinant of thermal history is the thermal cycle, whose in-situ measurements are still a big challenge. Water as the welding environment complicates this issue even more. The article presents a method to determine an equation for calculating t8/5 cooling times for underwater gas metal arc welding of unalloyed steels...
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Detection of ferromagnetic objects in local magnetic anomaly of the Baltic Sea
PublikacjaIn geological researches several kinds of methods are applied to discovering the natural resources. Planes, helicopters and UAVs (UnmAnned Vehicle) are used in researches in large areas. The gravity, electromagnetic and magnetic methods, which are used in geological researches, are presented in this paper. The special attention was paid to magnetic systems installed on mobile platforms. The magnetic field of the Earth obtained...
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Sustainable Chemically Modified Mater-Bi/Poly(ε-caprolactone)/Cellulose Biocomposites: Looking at the Bulk through the Surface
PublikacjaSustainable polymer composites are progressively under development in a technological paradigm shift from "just use more and more" to "convert into value-added products". The bio-based blends based on Mater-Bi bio-plastic (A) and poly(ε-caprolactone) (B), at a weight ratio of 70:30 (A:B) were developed, followed by the addition of UFC100 cellulose (C) filler to yield 70/30 (w/w) (A:B)/C sustainable biocomposites. The effects of...
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Dowodzenie w Policji – koncepcja zmian w zakresie dowodzenia formacją
PublikacjaThe dynamic development of human civilization at the turn of the 20th and 21st centuries unfortunately generates not only positive developments. So we need to constantly improve crisis management systems. The purpose of the research was to improve the police command system. Primarily, the research was based on the methods of non-standard observation and analysis and logical construction. The article presents the command in the...
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Application of gaze tracking technology to quality of experience domain
PublikacjaA new methodological approach to study subjective assessment results employing gaze tracking technology is shown. Notions of Human-Computer Interaction (HCI) and Quality of Experience (QoE) are shortly introduced in the context of their common application. Then, the gaze tracking system developed at the Multimedia Systems Department (MSD) of Gdansk University of Technology (GUT) is presented. A series of audio-visual subjective...
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Coastal zone monitoring using Sentinel-1 SAR polarymetry data
PublikacjaIn recent years the role of the surveillance and security of Polish boundaries has significantly increased. Polish coastal zone monitoring requires various approaches using various technological means in order to ensure the protection of Polish boundaries. In this paper, the authors discuss and present alternatives to underwater surveillance methods of coastal area analysis and monitoring using data retrieved from the newly developed...
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Toward Safe and Efficient Recovery of Gas Munitions Dumped at Sea
PublikacjaThe proposal of a system for the safe recovery of unexploded ordnance (UXO), chemical weapons (CW) and chemicalwarfare agents (CWA) dumped at sea mainly after WWI and WWII is described in this work. The proposed solutionaddresses the tasks required to neutralise thousands of tons of dumped material and the currently available solutionsand proposed ideas. Requirements concerning the features of a recovery system are defined and...
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THE DETERMINATION OF ABRASION RESISTANCE OF SELECTED BIOMATERIALS FOR THE FRICTION PAIRS IN THE HIP JOINT ENDOPROSTHESIS
PublikacjaThe key requirement for the modern endoprosthesis is high durability of the friction components, which results in long and trouble-free operation in the human body. The durability of currently used endoprosthesis is often limited by tribological wear processes of friction components (e.g. between the head and the acetabular component in a hip joint endoprosthesis) [8, 19, 23, 24]. In order to compare the tribological wear, tribological...
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Shallow-Water Acoustic Communications in Strong Multipath Propagation Conditions
PublikacjaA phenomenon that has a strong impact on signal transmission conditions in Underwater Acoustic Communication (UAC) systems is multipath propagation. As a result of multipath propagation, the transmitted signal undergoes time dispersion which results in inter-symbol interference observed on the receiving side. Time dispersion is large, especially in horizontal channels in shallow waters which significantly limits the transmission...
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Adhesion of organic coatings to hot-dip galvanized steel
PublikacjaDuplex systems provide long-time corrosion protection, much longer than the sum of the lifetimes of zinc and paint used individually. However loss of adhesion between coating and zinc substrate is often found in practice. Different methods of zinc surface preparations are used in the fi eld. The aim of this study was to examine and compare coating protection when the old zinc surface, stored during long-time period (15 years) in...
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Seafloor relief reconstruction from side scan sonar data
PublikacjaSide scan sonar is one of the most widely used imaging systems in the underwater environment. It is relatively cheap and easy to deploy, in comparison with more powerful sensors. Although side scan sonar does not provide seafloor bathymetry directly, its records are directly related to seafloor images. In the paper, the method for 3D seafloor relief reconstruction from side scan sonar data is presented. The method is based on the...
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A cryptic ribosome binding site, false signals in reporter systems and avoidance of protein translation chaos
PublikacjaThe expression of reporter gene may be induced by activation of cryptic signalling sequences, as we found while constructing the mutS-lacZ fusion gene. We cloned the Escherichia coli lacZ gene encoding beta-galactosidase into a plasmid vector carrying the Thermus thermophilus mutS gene. The clones expected to produce beta-galactosidase as the C-terminal fusion were selected for the complementation of beta-galactosidase activity...
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Study of the Performance of DSSS UAC System Depending on the System Bandwidth and the Spreading Sequence
PublikacjaA signal transmitted in an Underwater Acoustic Communication (UAC) system operating in a shallow-water channel suffers from strong time dispersion due to multipath propagation. This causes the Inter-Symbol Interference (ISI) observed in the received signal, which significantly limits the communication system’s reliability and transmission rate. In such propagation conditions, the Direct-Sequence Spread Spectrum (DSSS) method is...
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Acoustic Processor of the Mine Countermeasure Sonar
PublikacjaThis paper presents the concept of an acoustic processor of the mine countermeasure sonar. Developed at the Department of Marine Electronics Systems, Gdansk University of Technology, the acoustic processor is an element of the MG-89, an underwater acoustic station. The focus of the article is on the modules of the processor. They are responsible for sampling analogue signals and implementing the algorithms controlling the measurement...
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A tool for designing water tanks for measuring hydroacoustic transducers
PublikacjaSpecial water tanks are commonly used to measure the parameters of underwater acoustic systems. They must meet specific requirements, the fulfilment of which ensures very small but acceptable measurement errors. These requirements define the size of the tank and its shape as well as the strong attenuation of reflected waves. At the design stage, it is necessary to determine the impact of the tank structure on the measurement errors...
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Adaptive Identification of Underwater Acoustic Channel with a Mix of Static and Time-Varying Parameters
PublikacjaWe consider the problem of identification of communication channels with a mix of static and time-varying parameters. Such scenarios are typical, among others, in underwater acoustics. In this paper, we further develop adaptive algorithms built on the local basis function (LBF) principle resulting in excellent performance when identifying time-varying systems. The main drawback of an LBF algorithm is its high complexity. The subsequently...
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Badania stabilności biologicznej wody w wybranych systemach wodociągowych
PublikacjaW pracy przedstawiono wyniki badań mikrobiologicznych wody powierzchniowej i wód podziemnych z rejonu Trójmiasta, które zasilają systemy dystrybucji charakteryzujące się nikim stosunkiem powierzchni kontaktu do objętości przesyłanej wody (≈0,65) w aspekcie ich stabilności biologicznej. Dokonano oceny skuteczności zastosowanych procesów uzdatniania w usuwaniu ogólnej liczby bakterii (OLB), a w badaniach laboratoryjnych określono...
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Triangular 3D Laser Scanning in Underwater Photogrammetry
PublikacjaThe use of triangular 3D laser scanning may significantly enhance the visual inspection of underwater objects. In these days of high demand for accurate information, exclusively photographic documentation is not enough, as it is geometrically flawed. The authors of this article are trying to present the rudiments of laser scanning, a modern means of measuring, which is reliable, relatively easy to use and works in accordance with...
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System for characterisation and multidimensional imaging of seafloor using multibeam sonar data
PublikacjaMultibeam sonars are widely used in applications like high resolution bathymetry measurements, underwater object detection and imaging, etc. Also, they are the promising tool in seafloor characterisation and classification, having several advantages over conventional single beam echosounders. The proposed approach to seafloor classification relies on the combined use of three different techniques. In each of them, a set of descriptors...
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Theoretical Model of Acoustic Wave Propagation in Shallow Water
PublikacjaThe work is devoted to the propagation of low frequency waves in a shallow sea. As a source of acoustic waves, underwater disturbances generated by ships were adopted. A specific feature of the propagation of acoustic waves in shallow water is the proximity of boundaries of the limiting media characterised by different impedance properties, which affects the acoustic field coming from a source situated in the water layer “ deformed”...
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Sensors and System for Vehicle Navigation
PublikacjaIn recent years, vehicle navigation, in particular autonomous navigation, has been at the center of several major developments, both in civilian and defense applications. New technologies, such as multisensory data fusion, big data processing, or deep learning, are changing the quality of areas of applications, improving the sensors and systems used. Recently, the influence of artificial intelligence on sensor data processing and...
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Experimental bases for the rail track surface damage detection system
PublikacjaA diagnosis of rail surface is generally based on the classical method of direct assessment and track geometry measurements. Identification and qualification of inequality and damage on the surface rails is depend on the skills and experience person who conducting inspection. In times of increasing exploitation of railways, infrastructure managers decide to use systems supporting the assessment of technical condition of the railways....
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Fluorine ions in photocatalysts’ synthesis: an obstacle or an ally? The investigation of photocatalysts in Ti-O-F system
PublikacjaTitanium(IV) oxide (TiO2) is one of the most promising photocatalysts, which is expected to be applied in the photocatalytic degradation of xenobiotics. For sustainable development and green chemistry approach recently, much effort has been paid to enhance TiO2 photocatalytic activity in UV-vis light by modifying its structure. The photocatalytic process’s complexity cannot be simply described as electron-hole pairs generations...
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Three-dimensional geographically weighted inverse regression (3GWR) model for satellite derived bathymetry using Sentinel-2 observations
PublikacjaCurrent trends of development of satellite derived bathymetry (SDB) models rely on applying calibration techniques including analytical approaches, neuro-fuzzy systems, regression optimization and others. In most of the cases, the SDB models are calibrated and verified for test sites, that provide favourable conditions for the remote derivation of bathymetry such as high water clarity, homogenous bottom type, low amount of sediment...
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Objectivity in the non-Markovian spin-boson model
PublikacjaObjectivity constitutes one of the main features of the macroscopic classical world. An important aspect of the quantum-to-classical transition issue is to explain how such a property arises from the microscopic quantum theory. Recently, within the framework of open quantum systems, there has been proposed such a mechanism in terms of the so-called spectrum broadcast structures. These are multipartite quantum states of the system...
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Mohammad Hossein Ghaemi dr inż.
OsobyMohammad Hossein Ghaemi (ur. 1967), adiunkt Wydziału Oceanotechniki i Okrętownictwa (WOiO) PG w Katedrze Automatyki i Energetyki. Jest absolwentem Uniwersytetu Teherańskiego z zakresu mechaniki ciała stałego, a także PG na kierunku Oceanotechnika. Uzyskał stopień doktora nauk technicznych na PG w 2004 roku. Od 1995 roku pracuje na WIMiO PG (do 2020 r. WOiO PG) i prowadzi zajęcia dydaktyczne i badania naukowe w zakresie automatyki...
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A model of stealth maritime object having some innovative solutions concerning the object form, structure and materials.
Dane BadawczeThe aim of the project is to work out a model of the stealth maritime object which will have innovative solutions concerning the object form, structure and materials. These solutions should enable a modification of combinations of the object features defining the object stealth characteristics (difficulty of the object detection in the water). It is...
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New Aspects of Virtual Sound Source Localization Research—Impact of Visual Angle and 3-D Video Content on Sound Perception
PublikacjaThe influence of image on virtual sound source localization, called the “image proximity effect” or the “ventriloquism effect”, is a well known phenomenon. This paper focuses on other aspects related to this effect, namely the impact of the visual angle of the presented object and 3D video content on sound perception. The research conducted confirmed that the visual angle of the presented object determines the image proximity effect...
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Biopsy needles coated with the antimicrobial coatings
PublikacjaDrug delivery systems are used to achieve higher therapeutic effects of medicaments in a specific diseased site with minimal toxicological effect. The used of biopolymers in drug delivery systems ensure the biocompatibility, biodegradability and low immunogenicity. Drug delivery systems enhance the drug delivery actively and can be used in different diseases. In this study, two types of polymer coatings were prepared and were...
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MAPPING SOUTH BALTIC NEAR-SHORE BATHYMETRY USING SENTINEL-2 OBSERVATIONS
PublikacjaOne of the most promising new applications of remote observation satellite systems (RO) is the near-shore bathymetry estimation based on spaceborn multispectral imageries. In recent years, many experiments aiming to estimate bathymetry in optically shallow water with the use of remote optical observations have been presented. In this paper, optimal models of satellite derived bathymetry (SDB) for relatively turbid waters of the...
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Microfluidic devices for photo-and spectroelectrochemical applications
PublikacjaThe review presents recent developments in electrochemical devices for photo- and spectroelectrochemical investigations, with the emphasis on miniaturization (i.e., nanointerdigitated complementary metal-oxide-semiconductor devices, micro- and nano-porous silicon membranes or microoptoelectromechanical systems), silica glass/microreactors (i.e., plasmonic, Raman spectroscopy or optical microcavities) or polymer-based devices (i.e.,...
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An Intergrated Model of Motion, Steering, Positioning and Stabilization of an Unmanned Autonomous Maritime Vehicle
PublikacjaIn the paper the aim of an interdisciplinary research is presented. The research method is introduced. An object the unmanned autonomous maritime vehicle is briefly described. The key research problem concerns a combined model of the vehicle motion including the loads of lift and hydrodynamic nature. The model takes into account the gravity and displacement forces, resistance and thrust forces, lift and other hydrodynamic forces....
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Acoustic Processor of the MCM Sonar
PublikacjaThis paper presents the concept of an acoustic processor of the mine countermeasure sonar. Developed at the Department of Marine Electronics Systems, Gdansk University of Technology, the acoustic processor is an element of the MG-89, a modernised underwater acoustic station. The focus of the article is on the modules of the processor. They are responsible for sampling analogue signals and implementing the algorithms controlling...
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Microscopic examination of the texture of paper products
Dane BadawczeAtomic force microscopy (AFM) can be used to study the state of the paper fibers with the aim of providing qualitative and semi-quantitative information on degradation and aging. The work [1] reports the results of tests of various paper products subjected to deliberate aging processes under the influence of various factors. Chemical and biological...
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The effect of laser on metal surfaces for multidisciplinary usage in material and thermal engineering
PublikacjaThe subject of heat transfer and cooling systems is still a matter of contention in many different fields of science and industry. Infrigidation is much more difficult than warming, and so, much more needed in more and more different devices, starting from massive industrial machinery and air conditioning in commercial buildings, up to micro and nano-surgery tools. In fact, the size of many cooling systems is still a problem. It...
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Probabilistic Analysis of Structure Models using Target Random Sampling (TRS)
PublikacjaThe work presents testing methods of sensitivity and reliability of mechanical or structural systems. All computations concerned the case of Zigler column, a simple model of a compressed column involving two random variables only. A conclusion was drawn that the standard Monte Carlo method, its reduction variants and the response surface method allow to assess the sensitivity of structural response to the variation of random structural...
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Józef Kotus dr hab. inż.
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Sustainable chemically modified poly(butylene adipate-co-terephthalate)/thermoplastic starch/poly(ε-caprolactone)/cellulose biocomposites: looking at the bulk through the surface
PublikacjaSustainable polymer composites (or biocomposites) based on renewable and green polymers are progressively under development in a technological paradigm shift from “just use more and more” to “convert into value-added products”. Therefore, significant efforts should focus not only on their reduced environmental impact but also on maximizing their performance and broadening their application range. Herein, the bio-based blends based...
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Silicon microcantilever with impedance sensor
Dane BadawczeThe issue of microelectromechanical systems (MEMS) [1] has been enjoying popularity and interest since the 90s of the 20th century. Microcells are one of the simplest devices of this type, but they can be widely used in sensors. There are reports on the possibility of using this type of sensors in the context of such important issues as diagnostics...
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Has EGNOS its own place in maritime navigation?
PublikacjaGNSS (in fact it usually means GPS) is at the moment the fundamental means of positioning for any variants of navigation. However some attributes of it can be not sufficient for every users or in some tasks, so there are any cases when this system needs support. From the mariner point of view pure GPS properties perfectly fulfils expectations of sailors at the open sea, however there are lot of cases, when accuracy of the system...
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Evaluation of Open Source SIEM for Situation Awareness Platform in the Smart Grid Environment
PublikacjaThe smart grid as a large-scale system of systems has an exceptionally large surface exposed to cyber-attacks, including highly evolved and sophisticated threats such as Advanced Persistent Threats (APT) or Botnets. When addressing this situation the usual cyber security technologies are prerequisite, but not sufficient. The smart grid requires developing and deploying an extensive ICT infrastructure that supports significantly...
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ECHOES REDUCTION DURING DIGITAL DATA TRANSMISSION IN HYDROACOUSTIC CHANNEL – LABORATORY EXPERIMENT
PublikacjaThe possibility of using a hydroacoustic channel for digital data transmission is very limited. This is due to the effect of multipath propagation of the emitted acoustic wave and the damping of the mechanical wave in this medium, which increase with frequency. The first of these phenomena results in inter-symbol interference disturbances in data transmission systems, including even hundreds of symbols. Due to the number of reflections...
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Nanostructures fabrication with use of electrical AFM litography
Dane BadawczeIn the last 10 years, one of the nanotechnological trends has been observed, consisting in the development of new variants of computer memory systems with high capacity and speed of access, using quantum dots. One of the techniques for creating nanodots and other nanostructures is based on the use of an atomic force microscope acting as a lithographic...
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3D Object Shape Reconstruction from Underwater Multibeam Data and Over Ground Lidar Scanning
PublikacjaThe technologies of sonar and laser scanning are an efficient and widely used source of spatial information with regards to underwater and over ground environment respectively. The measurement data are usually available in the form of groups of separate points located irregularly in three-dimensional space, known as point clouds. This data model has known disadvantages, therefore in many applications a different form of representation,...
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Hyperbolic Asynchronous Method of a Radio Navigation Technique
PublikacjaHumans have always wanted to determine position in an unknown environment. At the beginning methods were simple. They were based on the observation of characteristic points, in the case of shipping additional observations of the coastline. Then came navigation based on astronomical methods (astronavigation). At the beginning of the XX-century a new way of determining the current location was developed. It has used radiowave signals....
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Integracja bezprzewodowych heterogenicznych sieci IP dla poprawy efektywności transmisji danych na morzu
PublikacjaWraz ze wzrostem istotności środowiska morskiego w naszym codziennym życiu np. w postaci zwiększonego wolumenu transportu realizowanego drogą morską. czy zintensyfikowanych prac dotyczących obserwacji i monitoringu środowiska morskiego, wzrasta również potrzeba opracowania efektywnych systemów komunikacyjnych dedykowanych dla tego środowiska. Heterogeniczne systemy łączności bezprzewodowej integrowane na poziomie warstwy sieciowej...
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Shipping Low Frequency Noise and Its Propagation in Shallow Water
PublikacjaOne of the most significant factor influencing acoustical climate of the sea is underwater noise generated by moving ships. If the considered sea area has features of the shallow water, namely the wave frequency fulfils relation f < 10c/h, where c denotes phase speed of sound, and h is depths of the sea, then in certain distance from the wave source specific image of sound pressure distribution in the mean of wave modes appears....
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Web-based 3D processing and dissemination of multibeam sonar data
PublikacjaThe continuous detailed surveys of the various water bodies over time produce a large and ever-increasing volume and density of underwater sounding data. Three-dimensional data, such as those obtained by multibeam sonar systems, are quite complex to manage, and thus their growing numbers increase the pressure on development of new solutions dedicated to processing them. This paper presents a concept system for web-based dissemination...
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Mathemathical model of radial passive magnetic bearing
PublikacjaIn the article mathematical radial model of passive magnetic bearings to ocean engineering units has been presented. The units application in underwater thrusters should increase propulsion systems durability and gives lower maintenance costs. The rotor of electric motor is hanging in magnetic field taken from radial passive magnetic bearings. However axial direction maintenance must be controlled with electromagnets and their...
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Structural and Transportation Properties of Strontium Titanate Composites with Ion Conductive Oxides
PublikacjaThis paper has been written based on the author’s doctoral dissertation “Structural and transportation properties of strontium and titanate composites with ion conductive oxides”, prepared under the supervision of Prof. Dr. Hab. Eng. Bogusław Kusz at the Department of Solid State Physics of Gdańsk University of Technology. It reports the idea of the thesis and conclusions from the study. Niobium doped strontium titanate (Sr(Ti,Nb)O3)...