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Wyniki wyszukiwania dla: MARINE AND BRIDGE STRUCTURES
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The accuracy of a marine satellite compass under terrestrial urban conditions
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The Accuracy of a Marine Satellite Compass under Terrestrial Urban Conditions
PublikacjaWhen used at sea, satellite compasses are capable of determining the course of a sailing vessel with high accuracy. It is dicult to verify the accuracy declared by the device manufacturer under such conditions, as it is dicult to define a reliable reference. This study analyses the accuracy of the satellite compass in an urban setting, with the satellite signal being obscured to various extents. It is an important point in the...
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Global defensive secure structures
PublikacjaLet S ⊂ V (G) for a given simple non-empty graph G. We define for any nonempty subset X of S the predicate SECG,S(X) = true iff |NG[X]∩S| ≥ |NG[X]\S|. Let H be a non-empty family of graphs such that for each vertex v ∈ V (G) there is a subgraph H of G containing v and isomorphic to a member of H. We introduce the concept of H-alliance extending the concept of global defensive secure structures. By an H-alliance in a graph G we...
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Pre-swirl energy saving device in marine application
PublikacjaThis paper covers topics of energy saving device (ESD) with application to marine propulsors. The form of ESD, considered in this paper, consists of fixed lifting foils mounted in front of the screw propeller (the pre-swirl stator/guide vanes). An algorithm for designing propulsion systems, consisting of guide vanes and screw propeller, is presented. The proposed method relies on hybrid lifting line (guide vanes)-lifting surface...
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Origin and fate of nanoparticles in marine water – Preliminary results
PublikacjaThe number, morphology and elemental composition of nanoparticles (<100 nm) in marine water was investigated using Variable Pressure Scanning Electron Microscopy (VP-SEM) and Energy-dispersive X-ray spectroscopy (EDS). Preliminary research conducted in the Baltic Sea showed that the number of nanoparticles in seawater varied from undetectable to 380 (x102) cm-3. Wind mixing and density barriers (thermocline) had a significant impact...
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Bacterial Community Structures in Freshwater Polar Environments of Svalbard
PublikacjaTwo thirds of Svalbard archipelago islands in the High Arctic are permanently covered with glacial ice and snow. Polar bacterial communities in the southern part of Svalbard were characterized using an amplicon sequencing approach. A total of 52,928 pyrosequencing reads were analyzed in order to reveal bacterial community structures in stream and lake surface water samples from the Fuglebekken and Revvatnet...
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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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Bridge Non-Destructive Measurements Using a Laser Scanning during Acceptance Testing: Case Study
PublikacjaOwing to the recent proliferation of inventory works on roads and railways, bridge acceptance tests have increased exponentially. These tests’ results are often misinterpreted owing to the use of various measuring equipment types, rendering integrated interpretation problematic. It is also problematic that adjusting the measurement method is difficult when the structure’s response to load is uncertain. Therefore, it is important...
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A novel sandwich footbridge - Practical application of laminated composites in bridge design and in situ measurements of static response
PublikacjaA novel sandwich composite footbridge is presented in the paper, as an example of practical application of laminated composites in civil engineering. The in situ static load tests of the footbridge before its acceptation for exploitation are shown and discussed. The results are compared with the corresponding ones from a numerical equivalent single layer model of the sandwich structure created within the framework of finite element...
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ADAPTIVE BACKSTEPPING TRACKING CONTROL FOR OVER-ACTUATED DP MARINE VESSEL WITH INERTIA UNCERTAINTIES
PublikacjaDesigning a tracking control system for an over-actuated dynamic positioning marine vessel in the case of insufficient information on environmental disturbances, hydrodynamic damping, Coriolis forces and vessel inertia characteristics is considered. The designed adaptive MIMO backstepping control law with control allocation is based on Lyapunov control theory for cascaded systems to guarantee stabilization of the marine vessel...
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Water-Lubricated Journal Bearings Marine Applications, Design, and Operational Problems and Solutions
PublikacjaWater-Lubricated Journal Bearings: Marine Applications, Design, and Operational Problems and Solutions provides cutting-edge design solutions, common problems and methods for avoiding them, and material selection considerations for the use of water-lubricated journal bearings in marine environments. These bearings have many advantages, including the absence of the potential for oil contamination. They are also sensitive, and their...
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Experimental and Numerical Study on Pounding of Structures in Series
PublikacjaPounding between structures in series during earthquakes may cause serious damage in the structural elements. The aim of this paper is to show the results of an experimental and numerical study that is focused on pounding between more than two structures which may be described as “structures in series”. In this study, the shaking table experiments, as well as the numerical analyses, were performed using three tower models including...
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Hybrid Finite Element Method Development for Offshore Structures’ Calculation with the Implementation of Industry Standards
PublikacjaIn the design process of offshore steel structures, it is typical to employ commercial calculation codes in which simulation and evaluation of results are performed on the basis of the available standards (e.g. API, DNV, Lloyds). The modeling and solution rely on finite element methods and cover the simulation of the structure’s properties along with the influence of the marine environment – sea currents, wave and wind loading,...
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Sources and fate of microplastics in marine and beach sediments of the Southern Baltic Sea—a preliminary study
PublikacjaMicroplastics’ sources and fate in marine bottom and beach sediments of strongly polluted Baltic Sea have been investigated.Microplastics were extracted using sodium chloride. Their qualitative identification was conducted using micro-Fourier-transform infrared spectroscopy (μFT-IR).
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Naprawa przegubów Estakady Kwiatkowskiego w Gdyni = Hinges repair og the E. Kwiatkowskiego trestle bridge in Gdynia
PublikacjaE. Kwiatkowskiego trestle bridge is one of the main parts of road infrastructure that connects sea transport (container terminal BTC) national roads A1,1,7. Every limitation of motor traffic causes many problems for Gdynia inhabitants and moreover economical loss in transport economy. In recent two years there were expertise and repair project of hinges carried out. Paper presents genesis and reasons of hinges damages, theoretical...
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Diagnosing marine turbine engines through energy characteristics of their flow section
PublikacjaThe aim of the performed research was to develop of diagnostic method of the flow section of a marine turbine combustion engine based on the level of delamination of its energy characteristics. The here adopted diagnostic model provides for a formulation of the evaluation of the technical conditions based on the measurements of the parameters of the thermodynamic medium in the characteristic control cross-sections of the engine...
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Support for argument structures review and assessment
PublikacjaArgument structures are commonly used to develop and present cases for safety, security and for other properties of systems. Such structures tend to grow excessively, which causes problems with their review and assessment. Two issues are of particular interest: (1) systematic and explicit assessment of the compelling power of an argument, and (2) communication of the result of such an assessment to relevant recipients. The paper...
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Recent steel structures in Poland - the selected projects
PublikacjaThe paper presents selected examples of recently completed steel structures in Poland. These are roofs over sport stadiums, construction of public buildings and bridges. Described examples do not exhaust the acquis in the field of steel constructions in Poland. The authors, however, may hope that the presented con-structions represents current achievements in Poland in the field of steel structures.
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Special Issue: “Non-Destructive Testing of Structures”
PublikacjaThe Special Issue “Non-Destructive Testing of Structures” has been proposed to present recent developments in the field of diagnostics of structural materials and components in civil and mechanical engineering. The papers highlighted in this editorial concern various aspects of non-invasive diagnostics, including such topics as condition assessments of civil and mechanical structures and connections of structural elements, the...
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Shaping the spatial structures of post-socialist cities
PublikacjaThis paper deals with issues and problems associated with transformation of spatial structures of post-socialist cities. The special attention is paid to the cases of Polish cities and towns and the analysis of their evolution – from the “post-communist structures” to the “cities in the age of globalization”. In the light of this the factors influencing the spatial transformation of these are analyzed. The paper is concluded with...
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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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Meander anisotropic magnetoresistance bridge geomagnetic sensors
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Laser Scanning of a Soil-Shell Bridge Structure
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Controlling nodal displacement of pantographic structures using matrix condensation and interior-point optimization: A numerical and experimental study
PublikacjaThis study presents an innovative approach for the precise control of nodal displacements in pantographic structures. The method is founded on the Matrix Condensation of Force Method, seamlessly integrated with an Interior Point Optimization algorithm. This combination offers a unique advantage by allowing users to manipulate displaced nodes within a defined coordination domain. Furthermore, this approach introduces the Interior...
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Application of the Optimization Methods to the Search of Marine Propulsion Shafting Global Equilibrium in Running Condition
PublikacjaFull film hydrodynamic lubrication of marine propulsion shafting journal bearings in running condition is discussed. Considerable computational difficulties in non-linear determining the quasi-static equilibrium of the shafting are highlighted. The approach using two optimization methods (the particle swarm method and the interior point method) in combination with the specially developed relaxation technique is proposed to overcome...
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Storm petrels as indicators of pelagic seabird exposure to chemical elements in the Antarctic marine ecosystem
PublikacjaData on trace element bioavailability in the south-polar marine ecosystem is still scarce, compared to that relating to temperate zones. Seabirds can be used as indicators of ecosystem health and sentinels of environmental pollution, constituting a link between marine and terrestrial environments. Here, we analysed the concentration of 17 elements (with special emphasis on mercury, Hg) in feathers of adults and chicks of two pelagic...
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Hybrid Finite Element Method Development for Offshore Structures’ Calculation with the Implementation of Industry Standards
PublikacjaIn the design process of offshore steel structures, it is typical to employ commercial calculation codes in which simulationand evaluation of results are performed on the basis of the available standards (e.g. API, DNV, Lloyds). The modelingand solution rely on finite element methods and cover the simulation of the structure’s properties along with the influenceof the marine environment – sea currents, wave...
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Space-vector pulsewidth modulation for a seven-level cascaded H-bridge inverter with the control of DC-link voltages
PublikacjaThe control strategy of DC-link voltages for a seven-level Cascaded H-Bridge inverter is proposed in this paper. The DC-link voltage balancing is accomplished by appropriate selection of H-Bridges and control of their duty cycles in Space-Vector Modulation (SVM) algorithm. The proposed SVM method allows to maintain the same voltage level on all inverter capacitors. Regardless of the balancing function, the...
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Partially Isolated Multi-Active Bridge DC-DC Converter with Bidirectional EV Charging Ports
PublikacjaThere is a growing interest in multiport converters due to their ability to interconnect various energy sources and loads using reduced number of components. Regarding electric vehicle (EV) chargers connection, existing multiport solutions either lack scalability, featuring only one isolated charging port or the operation of ports depend on each other, complicating the converter control algorithm. This article proposes a partially...
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Possibilities of the performance improvement of the aero- and marine propulsion units equipped with combustion piston engines
PublikacjaWithin the paper there have been presented the authors' opinions concerning possibilities and needs of the performance optimization of the aero- and marine units powered by piston engines both of ''classic'' and contemporary construction. There have been also discussed the reserves contained within combustion piston engines which enable its performance improvement (the power and specific fuel consumption) as well as the fulfillment...
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Generalized Taylor formula and shell structures for the analysis of the interaction between geosythetics and engineering structures of transportation lines
PublikacjaThe analysis of the interaction between geosynthetics and engineering structures (e.g. railroad bed, soil foundation, pipeline) assumes that the geosynthetic form elastic membranes or shell laid on different types of foundations. The mathematical description of that problems in continuous domain employs Laplace operator Δ or d’Alembert operator □. In this paper we demonstrate the analysis based on generalize Taylor formula, and...
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HEALTH MONITORING OF A COMPRESSION IGNITION ENGINE FED WITH DIFFERENT LOW-SULPHUR MARINE FUELS BY ENDOSCOPIC IMAGE PROCESSING AND ANALYSIS
PublikacjaThis article characterises the methodology for the endoscopic testing of a laboratory diesel engine used for testing marine fuels. The ‘Shadow’ measurement method used in the XLG3 type EVEREST digital endoscope, for quantitative and qualitative identification of detected surface defects, was approximated. Representative endoscopic images of the elements limiting the working space of the research engine are demonstrated, having...
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Technical evaluation of marine auxiliary diesel engine on the basis of parameters synchronous generator
PublikacjaThe article presents a method for evaluating the technical condition of selected structural elements of the reciprocating internal combustion engine driving a synchronous generator. Th results of measurements of the electric generator parameters are the diagnostic information source. On this basis it is possible to determine the instantaneous angular speed marine engine crankshaft which, in turn, is the basis for reasoning about...
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Stability evaluation of the marine propulsion unit mechanical system bymeans of vibrations measurements and their analysis.
PublikacjaIn paper selected issues concerning vibration diagnosis of the mechanical system within marine propulsion units have been given. The analysis of vibration parameters was carried out on the basis of experimental examinations of a real object in which an exceedance of the allowable vibration's level had been observed. In the beginning, the vibration apparatus being on laboratory equipment of the Department of Ship Power Plants of...
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Stability evaluation of the marine propulsion unit's mechanical system by means of vibration measurements and their analysis
PublikacjaIn this paper selected issues concerning vibration diagnosis of the mechanical system within marine propulsion units have been given. The analysis of vibration parameters was carried out on the basis of experimental examinations of a real object in which an exceedance of the allowable vibration's level had been observed. In the beginning, the vibration apparatus being on laboratory equipment of the Department of Ship Power Plants...
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Hybrid Analysis of Structures Composed of Axially Symmetric Objects
Publikacja— A hybrid method for the scattering problems in shielded and open structures is presented. The procedure is based on the combination of body-of-revolution involving finite-element methods with impedance matrix formulation and the mode-matching technique, which can be utilized for the analysis of structures with axially symmetrical scatterers. In order to confirm the validity and efficiency of the proposed approach, a few examples...
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GIS for remote sensing, analysis and visualisation of marine pollution and other marine ecosystem components
PublikacjaW artykule przedstawiono koncepcję oraz prototyp morskiego systemu GIS do zdalnego monitorowania w czasie rzeczywistym zanieczyszczeń środowiska morskiego. System pozwala na gromadzenie i integrowanie danych z różnego rodzaju sensorów, takich jak echosondy jednowiązkowe, sonary boczne i echosondy wielowiązkowe.
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VIBRATION PARAMETERS FOR DAMAGE DETECTION IN STRUCTURES
PublikacjaThe aim of this paper is to examine how damage indicators are sensitive to changing number of frequencies and mode shapes and also to number and location of measurement points. The influence of measurement errors was also analyzed for all cases. For the analysis, those damage indicators are chosen which use changes in such modal parameters as natural frequencies and mode shapes and also differences between the curvatures of the damaged...
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Performance and Emission Modelling and Simulation of Marine Diesel Engines using Publicly Available Engine Data
PublikacjaTo analyse the behaviour of marine diesel engines in unsteady states for different purposes, for example to determine the fuel consumption or emissions level, to adjust the control strategy, to manage the maintenance, etc., a goal-based mathematical model that can be easily implemented for simulation is necessary. Such a model usually requires a wide range of operating data, measured on a test stand. This is a time-consuming process...
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Minimal surfaces and conservation laws for bidimensional structures
PublikacjaWe discuss conservation laws for thin structures which could be modeled as a material minimal surface, i.e., a surface with zero mean curvatures. The models of an elastic membrane and micropolar (six-parameter) shell undergoing finite deformations are considered. We show that for a minimal surface, it is possible to formulate a conservation law similar to three-dimensional non-linear elasticity. It brings us a path-independent...
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Role of public space in designing complex urban structures
PublikacjaThe aim of this article is to present the main assumptions about design studios as held in the Faculty of Architecture at Gdańsk University of Technology (FA-GUT), Gdańsk, Poland, adapted to the development of key competencies in the urban planning of complex urban structures. One of these competencies is the design of public spaces. The main goal of the studios was to deliver knowledge of the role of public spaces in the design...
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Historic bridge modelling using laser scanning, ground penetrating radar and finite element methods in the context of structural dynamics
PublikacjaPraca dotyczy modelowania MES zabytkowej konstrukcji mostowej przy użyciu danych geometrycznych pochodzących ze skanowania laserowego oraz georadaru. Z uwagi na brak badań materiału budujcego most, przeprowadza się analize wrażliwości konstrukcji na zmiany modułu sprężystości granitu.
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DIRECTIONS OF THE SCIENTIFIC RESEARCH CONDUCTED IN THE DEPARTMENT OF MARINE AND POWER PLANTS OF THE FACULTY OF OCEAN ENGINEERING AND SHIP TECHNOLOGY OF THE GDANSK UNIVERSITY OF TECHNOLOGY
PublikacjaIn this article the short historical outline of the Department of Marine and Land Power Plants of the Faculty of Ocean Engineering and Ship Technology of the Gdansk University of Technology was introduced. Its activity beginnings, in the post-war history of the University, reach 1952. The leading scientific issues, which have been developed for years in three principal directions: design, manufacture and operation of machines and...
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Marine traffic risk modelling – an innovative approach and a case study
PublikacjaThis paper presents a model to analyse the risk of two common marine accidents: collision and grounding. Attention is focused on oil tankers since they pose the highest environmental risks. A case study in selected areas of the Gulf of Finland in ice-free conditions is presented. The model utilizes a formula for risk calculation that considers both the probability of an unwanted event and its consequences. The model can be decomposed...
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SIGNIFICANT GUIDELINE FOR THE DAMAGE INDICES APPLIED TO REINFORCED CONCRETE STRUCTURES
PublikacjaIn this paper, based on a deep overview and literature study, the different formulas proposed for damage indices (DIs) applied to reinforced concrete structures under monotonic or cyclic loading are classified and presented. The DIs are applied to quantify the damages to structures, ranging from zero to one. Normally, they are applied to make a decision for repairing or demolition of the structures in the post-earthquake phases. Keywords:...
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Mechanics of Micro- and Nano-Size Materials and Structures
PublikacjaNanotechnology knowledge is always looking to expand its boundaries to achieve the mostsignificant benefit to human life and meet the growing needs of today. In this case, we can refer tomicro- and nanosensors in micro/nano-electromechanical systems (MEMS/NEMS). These electricaldevices can detect minimal physical stimuli up to one nanometer in size. Today, micro/nano-sensordevices are widely used in the...
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Organotin compounds in marine sediments
PublikacjaZwiązki cynoorganiczne są szeroko wykorzystywane w różnych sektorach gospodarki. Farby zawierające czynniki przeciwporostowe (biocydy), były wykorzystywane w ochronie przeciwkorozyjnej kadłubów statków i okrętów, są głównym źródłem emisji trójbutylo- i trójfenylocyny do środowiska morskiego.Międzynarodowa Organizacja Morska (IMO) wprowadziła w roku 2001 powszechny zakaz stosowania tych związków jako biocydów w powłokach malarskich....
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Determination of tributyltin in marine sediment.
PublikacjaPrzedstawiono wyniki badań międzynarodowego porównawczego, międzylaboratoryjnego oznaczania zawartości tributylocyny w osadzie morskim. Badania były organizowane przez Comite Consultatif pour la Quantite de Matiere (CCQM) pilot study P-18 international intercomparison i była to ich pierwsza część - badania pilotażowe. W badaniach uczestniczyło 11 laboratoriów. Uzyskano zadowalająco zgodne wyniki oznaczeń tributylocyny.
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On organic coatings in marine applications
PublikacjaZnaczna liczba konstrukcji eksploatowanych w warunkach morskich ulega zniszczeniu wskutek zmęczeniowego oddziaływania cyklicznych naprężeń mechanicznych. Również w przypadku powłok organicznych chroniących wspomniane konstrukcje obserwuje się przedwczesną degradację zmęczeniową. W poniższym artykule autorzy przedstawiają metodologię oceny wpływu cyklicznych naprężeń mechanicznych na trwałość ochronnych układów powłokowych. Badaniu...
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3D porous graphene-based structures- synthesis and applications
PublikacjaPorous carbon-based materials are of the great industrial and academic interest due to their high surface area, low density, good electrical conductivity, chemical inertness and low cost of fabrication. Up to now, the main approach to obtain porous carbon structures has involved the pyrolysis of carbonaceous natural or synthetic precursors. After the isolation of graphene, the interest in 3D porous graphene-based structures (called...