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Wyniki wyszukiwania dla: OPERATIONAL AMPLIFIERS
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Wideband Signal Generation for Jamming Radio-Controlled Improvised Explosive Devices
PublikacjaThis paper focuses on modelling operation of a wideband jamming signal generator, considering the effects present in real device which influence the shape of transmitted signal’s spectrum. Introduction is followed by a brief overview of AEGIS project, aim of which is to develop a mobile generator of electromagnetic curtain. Next, simulation model is described which includes the factors...
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Multipulse inverter structures with low voltage distortion
PublikacjaA novel approach to the voltage source inverters (VSI) construction is presented in the paper. The invented inverter structures allow to operate several DC/AC converters in parallel resulting in lower voltage distortions at extremely low switching frequency. The research presented in the paper describes such a parallel operation of the VSI’s which is possible thanks to the use of coupled inductors. The eighteen-pulse three-level...
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Redesign of the Research Platform for Monitoring, Control and Security of Critical Infrastructure Systems
PublikacjaCritical Infrastructure Systems (CISs) play a key role in modern societies. Their sustainable operation depends heavily on the performance of dedicated structures and algorithms targeting monitoring, control and security aspects. In previous work a Research Platform (RP) for the design and simulation of such systems was presented. This works updates the information on the RP through the description of major hardware and software...
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Investigation of energy deposition and its optical imaging in polymer gel dosimeters
PublikacjaThis following chapter describes methods for verifying the absorbed dose during radiotherapy. Special attention is paid to the method using polymer-gel dosimeters, the dose reading of which is performed by means of Laser Computed Tomography. The chapter also includes considerations on alternative solutions for dosimetric measurements and various types of radiotherapy and their pros and cons. In addition, both the methods of structural...
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New Design of Axial Piston Pump with Displaced Swash Plate Axis of Rotation for Hydro-Mechanical Transmissions
PublikacjaThis paper presents a prototype design of an axial piston pump with displaced swash plate axis of rotation in two directions of discharge with electronic control intended for installation on a hydraulic-mechanical gearbox dedicated to working machines. The effect of displacement of the swash plate rotation axis on dead space volume and volumetric efficiency is presented. The construction and principle of operation of the capacity...
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The use of various species of fungi in biofiltration of air contaminated with odorous volatile organic compounds
PublikacjaAir pollution with odorous compounds is a significant social and environmental problem. This paper presents biological deodorization methods. The attention is focused on the application of biotrickling filters for air deodorization. Principles of their operation are discussed, indicating the key role of the selection of microorganisms responsible for the degradation of odorous compounds. A literature overview of the used fungal...
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Autonomous port management based AGV path planning and optimization via an ensemble reinforcement learning framework
PublikacjaThe rapid development of shipping trade pushes automated container terminals toward the direction of intelligence, safety and efficiency. In particular, the formulation of AGV scheduling tasks and the safety and stability of transportation path is an important part of port operation and management, and it is one of the basic tasks to build an intelligent port. Existing research mainly focuses on collaborative operation between...
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Should we seek further improvement of fluid film bearings - what for and how?
PublikacjaFluid film bearings have been extensively used in the industry because of their unbeatable durability and extremely low friction coefficient. Large bearings supporting shafts of huge and important rotating machines constitute a special group of fluid film bearings since the reliability of crucial systems, like for example electro-energetic system, rely on their trouble-free operation. Large thrust bearings, apart from enormous...
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The Impact of Material Selection on Durability of Exhaust Valve Faces of a Ship Engine – A Case Study
Publikacjawo alloys were used in order to extend the service life of marine engine exhaust valve head. Layers of cobalt base alloys were made of the powders with with chemical composition as follow: the layer marked L12; C-1,55%; Si-1,21%; Cr-29,7%; W-9%; Ni-2%; Mo<0,01%; Fe-1,7%; Co-54,83% and the layer marked N; C-1,45%; Co-38,9%; Cr-24,13%; Ni-10,43%; W-8,75%; Fe-7,64%; Mo-7,56%; Si-2,59%. Base metal was valve steel after heat treatment....
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Leakage detection and localisation in drinking water distributionnetworks by MultiRegional PCA
PublikacjaMonitoring is one of the most important steps in advanced control of complex dynamic systems. Precise information about systems behaviour, including faults indicating, enables for efficient control. The paper describes an approach to detection and localisation of pipe leakage in Drinking Water Distribution Systems (DWDS) representing complex and distributed dynamic system of large scale. Proposed MultiRegional Principal Component...
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Multiscalar Control Based Airgap Flux Optimization of Induction Motor for Loss Minimization
PublikacjaBased on the induction motor model, considering the core loss resistance that accounts for magnetic characteristic saturation, a speed control approach is devised with an adaptive full-order (AFO) speed observer. The induction motor model analysis is done sincerely in a stationary reference frame. The control approach incorporates a flux reference generator designed to meet optimal operational circumstances and a nonlinear speed...
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FRP-based reinforcement coatings of steel with application prospects in ships and offshore structures: a review
PublikacjaLatest research on novel FRP-based anti-corrosion structural coatings (for enhancing structural capacity and strengthening the coating layer) is discussed with application prospects for ships and offshore structures. In the marine environment, structures constantly face corrosion and fatigue cracks. Combining this with high operational and wave loads, it might cause a structural collapse. Recently, polymer composites have been...
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An advanced synergy of partial denitrification-anammox for optimizing nitrogen removal from wastewater: A review
PublikacjaAnammox is a widely adopted process for energy-efficient removal of nitrogen from wastewater, but challenges with NOB suppression and NO3− accumulation have led to a deeper investigation of this process. To address these issues, the synergy of partial denitrification and anammox (PD-anammox) has emerged as a promising solution for sustainable nitrogen removal in wastewater. This paper presents a comprehensive review of recent developments...
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Revitalizing the Sacral Complex of the Parish of the Sacred Heart of Jesus in Gdynia: A Comprehensive Restoration Project in Alignment with Monument Conservator's Guidelines and Technical Prerequisites
PublikacjaReligiouscomplexes, due to their monumental character, belong to the group of facilities in which carrying out renovation works is difficult. Very often, construction works carried out as part of planned renovation work include not only modernization but also repair works, includingthose related to the reinforcement of structural elements. Renovation work in sacral buildings is particularly difficult when they...
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Recent advances in hydrodynamic cavitation-based pretreatments of lignocellulosic biomass for valorization
PublikacjaRecently, the hydrodynamic cavitation (HC)-based pretreatment has shown high effectiveness in laboratories and even in industrial productions for conversion of lignocellulosic biomass (LCB) into value-added products. The pretreatment capability derives from the extraordinary conditions of pressures at ∼500 bar, local hotspots with ∼5000 K, and oxidation (hydroxyl radicals) created by HC at room conditions. To promote this emerging...
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Quality Model for Integrated Security Monitoring and Control in Water Distribution Systems
PublikacjaThis article addresses the problem of drinking water distribution system (DWDS) security in the terms of water quality which in the era of terrorist threat is of high importance to the public. The contribution of this paper is the development of the so called security module to extend a multi-species water quality model. This gives an insight to the situation in DWDS not only under normal operational conditions but also in case...
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Development of trolleybus public transport in Gdynia as part of sustainable mobility strategy
PublikacjaIn many EU cities trolleybuses are experiencing a period of revitalization. New lines, new and modern trolley-buses, the use of auxiliary propulsion battery, eco-logical values and others, create great opportunities for that kind of public transport as an effective tool to shape transport policy in accordance with the principles of sustainable mobility. Gdynia is one of three cities in Poland with trolleybuses public transport...
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SDN testbed for validation of cross-layer data-centric security policies
PublikacjaSoftware-defined networks offer a promising framework for the implementation of cross-layer data-centric security policies in military systems. An important aspect of the design process for such advanced security solutions is the thorough experimental assessment and validation of proposed technical concepts prior to their deployment in operational military systems. In this paper, we describe an OpenFlow-based testbed, which was...
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EM-driven topology evolution for bandwidth enhancement of hybrid quadrature patch couplers
PublikacjaA broad operational bandwidth is one of the key performance figures of hybrid patch couplers. Due to the lack of systematic design procedures, bandwidth enhancement is normally obtained through manual modifications of the structure geometry. In this work, an optimization-based topology evolution for EM-driven design of patch couplers with enhanced bandwidth has been proposed. The method exploits a novel spline-based EM model where...
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DETERMINATION OF VERTICAL DISPLACEMENTS IN RELATIVE MONITORING NETWORKS
PublikacjaThe problem of determining displacements of objects is an important and current issue, in particular in terms of operational safety. This is a requirement that covers geodetic, periodic control measurements in order to determine horizontal and vertical displacements. The paper is focused on the analysis of vertical displacements. Geodetic measurements and their interpretation allow to reduce the risk of possible structural catastrophes....
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A CONCEPT OF DETERMINING THE RELATION BETWEEN LOAD AND WEAR OF TRIBOLOGICAL SYSTEMS OF SHIP MAIN SELF-IGNITION ENGINES BY USING PROBABILISTIC APPROACH PROBABILISTIC APPROACH
PublikacjaThis paper presents a proposal of simultaneous consideration of load and wear associated with it , of tribological systems of ship main engines (intended for ship propulsion) . Based on results of investigations it was assumed that both the load Q (i.e. a cause of wear ) and the wear Z (i.e. an effect of load occurrence) considered in a given time t(0 ≤ t ≤ t) are random variables Qt and Zt, respectively. There was characterized...
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Systems engineering approach to functional safety and cyber security of industrial critical installations
PublikacjaThis chapter addresses the systems engineering approach to integrated functional safety and cybersecurity analysis and management regarding selected references, standards and requirements concerning critical installations and their industrial automation and control system (IACS). The objective is to mitigate the vulnerability of industrial installations that include the information technology (IT) and the operational technology...
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Systems engineering approach to functional safety and cyber security of industrial critical installations
PublikacjaThis chapter addresses the systems engineering approach to integrated functional safety and cybersecurity analysis and management regarding selected references, standards and requirements concerning critical installations and their industrial automation and control system (IACS). The objective is to mitigate the vulnerability of industrial installations that include the information technology (IT) and the operational technology...
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Improvement of ships seakeeping performance by application of the full-scale cfd simulations
PublikacjaThe ship’s fuel economy is increasingly important. The paper presents the effect of redesigning a case study ship for increasing seakeeping performance. Selected wave parameters reflect very difficult operational conditions existing on the North Sea and the Baltic Sea. The analyzed variants of a case study ship represent the latest developments of modern hull forms. The concepts similar to V-shaped bulbous bow, X-bow, X-aft, B-bow...
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Zastosowanie redundancji w siłowniach okrętowych statków oceanotechnicznych
PublikacjaSystemy wytwarzania energii i napędu statków oceanotechnicznych muszą mieć bardzo wysoki poziom niezawodności. Utrata zdolności do wykonywania funkcji przez ich elementy strukturalne z reguły powoduje bardzo wysokie straty ekonomiczne. Straty te mogą być zwiększone przez niemożność wykorzystania tzw. okna pogodowego, skutkującego odłożeniem w czasie zaplanowanych operacji oceanotechnicznych. W celu zapewnienia niezawodnej realizacji...
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Instalacje fotowoltaiczne w budownictwie wielorodzinnym
PublikacjaArtykuł opisuje wpływ instalacji fotowoltaicznych na bezpieczeństwo eksploatacji budynków wielorodzinnych. W oparciu o projekty rzeczywistych obiektów przeprowadzono analizę zwiększenia ryzyka strat odgromowych, zmiany obciążenia konstrukcji dachu i wzrostu zagrożenia pożarowego na skutek montażu systemu fotowoltaicznego. Przeprowadzone obliczenia wskazują na konieczność kompleksowego podejścia do projektowania instalacji fotowoltaicznych....
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Partial inhibition of borohydride hydrolysis using porous activated carbon as an effective method to improve the electrocatalytic activity of the DBFC anode
PublikacjaCarbon materials are commonly used catalyst supports in various types of fuel cells. Due to the possibility of designing their properties, they seem to be attractive and functional additives. In Direct Borohydride Fuel Cells (DBFCs), the electrooxidation reaction of borohydride competes with the undesirable hydrolysis reaction, therefore our work aimed to modify anodes based on a multi-component hydrogen storage alloy with a small...
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CURRENT TRENDS IN RECYCLING OF PHOTOVOLTAIC SOLAR CELLS AND MODULES WASTE
PublikacjaIn comparison to other energy producing techniques, photovoltaics (PV) is one of the most promising options: no emission of any matter into the environment during operation; extremely long operation period (estimated average: 25 years), minimum maintenance, robust technique, aesthetic aspects. The use of photovoltaics is rapidly increasing, and the respective market is developing accordingly. Although PV manufacturing equipment...
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Recycling of Photovoltaic Solar Cells and Modules - Te State - Of - Art
PublikacjaIn comparison to other energy producing techniques, photovoltaics (PV) is one of the most promising options: no emission of any matter into the environment during operation; extremely long operation period (estimated average: 25 years), minimum maintenance, robust technique, aesthetic aspects. The use of photovoltaics is rapidly increasing, and the respective market is developing accordingly. Although PV manufacturing equipment...
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Investigation of the Combustion Processes in the Gas Turbine Module of an FPSO Operating on Associated Gas Conversion Products
PublikacjaIn this paper, we consider the issue of thermo-chemical heat recovery of waste heat from gas turbine engines for the steam conversion of associated gas for offshore vessels. Current trends in the development of offshore infrastructure are identified, and the composition of power plants for mobile offshore drilling units and FPSO vessels is analyzed. We present the results of a comparison of power-to-volume ratio, power-to-weight...
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The thermal effort during marine steam turbine flooding with water
PublikacjaThe work discussed an extreme case of cooling a steam turbine. The ship's steam turbine was used as an example. In marine transport units with low-speed engines dominate, however, there are also units with steam turbines. An example of analysed marine steam turbine is shown in Fig. 1. When considering the issue of cooling steam turbines, it is necessary to estimate the extreme conditions that may occur during operation of the turbine....
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All-gather Algorithms Resilient to Imbalanced Process Arrival Patterns
PublikacjaTwo novel algorithms for the all-gather operation resilient to imbalanced process arrival patterns (PATs) are presented. The first one, Background Disseminated Ring (BDR), is based on the regular parallel ring algorithm often supplied in MPI implementations and exploits an auxiliary background thread for early data exchange from faster processes to accelerate the performed all-gather operation. The other algorithm, Background Sorted...
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Methodology of experimental research on efficiency of hydro-mechanical automatic gearbox
PublikacjaThe article shortly describes the design and principle of operation of the hydromechanical gearbox and presents the methodology and design of test stands used for testing hydromechanical proto-type gearbox developed at Technical University of Gdansk. The article presents an approach according to which, in order to obtain reliable measurement data, it is necessary to separate the tests of the hydraulic and mechanical parts of the...
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Investigation of Transmit and Receive Characteristics of Laboratory Model for the Parametric Echosounder
PublikacjaInvestigation and operation of devices based on nonlinear interaction of high-intensity waves have been carried out for several decades. However, it is still a new tool to study the properties of the water environment and especially the upper layers of the seabed. This paper describes the results of tests of the new device that is intended to be applied for sounding underwater areas. The device has been designed and built in collaboration with...
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Analysis of inductive power transfer systems for variable air gap and voltage supply frequency
PublikacjaThe paper describes an IPT system, by which electrical energy may be transmitted through a large air gap between coils without electrical connection. It presents theoretical and simulation analysis of IPT, which allows for supplying a receiver in the conditions of slow, in relation to the dynamics of power supply, changes in dimension of the air gap. The influence of frequency characteristics of the system on the possible selection...
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Evaluation of bearing and journal damage in MAN 9L40-54 engines installed on M/V STENA SCANDINAVICA ferry
PublikacjaThe following report was requested by Remontowa Shiprepair Yard (RSY) S.A. in Gdansk ´ (contract no. 4/2018/EX/U, dated 13.02.2018) and prepared based on the materials received from RSY, two on-board inspections and the participation of the contractors in three conferences with RSY representativesi. The goal of the analysis performed by the experts of Gdansk University of Technology was ´ to determine the character of the bearing...
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All Nonclassical Correlations Can Be Activated into Distillable Entanglement
PublikacjaWe devise a protocol in which general nonclassical multipartite correlations produce a physically relevant effect, leading to the creation of bipartite entanglement. In particular, we show that the relative entropy of quantumness, which measures all nonclassical correlations among subsystems of a quantum system, is equivalent to and can be operationally interpreted as the minimum distillable entanglement generated between the system...
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A quaternion-based modified feistel cipher for multimedia transmission
PublikacjaIn this paper a quaternion-based modified Feistel Cipher is proposed. The algorithm is based on the scheme proposed by Sastry and Kumar (2012). Our algorithm uses special properties of quaternions to perform rotations of data sequences in 3D space for each of the cipher rounds. The plaintext (image in gray-tone) is divided into two square matrices of equal size which consist of Lipschitz quaternions. A modular arithmetic was implemented...
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Variations of Ship’s Deck Elevation Due to Stochastic Process of Containers Loading
PublikacjaThe stochastic process of container loading is described in the paper with special emphasis to ship motion when she is lying at a quay. The 3 DOF system was applied to describe rolling, pitching and heaving of a vessel which may cause a significant variations of momentary deck elevation. The realistic range of such variations are assessed for a variety of cargo locations on-board and a phase shift between two independent gantries...
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Multimedia distributed system for visualization of ongoing and archival events for BG
PublikacjaThe paper presents concept of the distributed system designed to gather and provide the information about vehicles, vessels and airplanes present within the area of operations of the Border Guard supplemented with related multimedia. The part of the system related to the map data gathering, distribution and visualization has been already implemented in the preceding project. The presented system is the expansion of the previous...
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Towards Effective Processing of Large Text Collections
PublikacjaIn the article we describe the approach to parallelimplementation of elementary operations for textual data categorization.In the experiments we evaluate parallel computations ofsimilarity matrices and k-means algorithm. The test datasets havebeen prepared as graphs created from Wikipedia articles relatedwith links. When we create the clustering data packages, wecompute pairs of eigenvectors and eigenvalues for visualizationsof...
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Theoretical analysis of a new approach to order determination for a modified Prony method in swath mapping application
PublikacjaThis article presents a new approach to determine the model order (number of principal components) in the modified Prony method applied to swath acoustic mapping. Determination of the number of principal components is a crucial step in the modified Prony method. In the proposed approach the model order is chosen based on the underlying physical model of the underwater acoustic environment, and utilised signal processing operations....
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A wireless network for off-shore marine research
PublikacjaThis paper presents functionality, the most important technology developments and potential use cases of digital communication system, developed to facilitate selected tasks commonly required during off-shore operations and marine research, including: broadband information sharing between platforms isolated from an on-shore communication infrastructure, acquisition of large data-sets from variety of off-shore...
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Modern Arrangement for Reduction of Voltage Perturbations
PublikacjaThe contents of this chapter encompass general problems and the most important issues of power-supply-quality improvement in AC systems. In the context of the above, consideration is given to evaluation of bilateral interactions of receivers with an electrical power-distribution system and methods of their reduction. Also are discussed the basis of operation of the most important compensation-filtration devices and their applications...
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Computer-aided analysis of resonance risk in power system with Static Var Compensators
PublikacjaStatic Var Compensators operation in a power system may significantly improve voltage profiles in nodes and the reactive power balance, as well as ensure greater system stability in emergency conditions. However these devices may be a cause of a resonance in the system. The aim of this paper is to call attention to the need to include resonance phenomena in a compensator’s location evaluation process. The analysis performed in...
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Photovoltaic demonstration set up
PublikacjaThe use of photovoltaics is growing rapidly in the industry as well as households. Therefore, educating the public will help them understand solar cell technology, which is becoming more common in everyday life. This paper proposes a demonstrational set-up of photovoltaic panel for the purpose of science education. It was used in numerous outreach activities such as science fairs. Moreover, it proved to be a great tool for education...
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Low voltage photovoltaic power system
PublikacjaThe use of photovoltaics is growing rapidly in the industry as well as households. Therefore, educating the public will help them understand solar cell technology, which is becoming more common in everyday life. This paper proposes a demonstrational set-up of photovoltaic panel for the purpose of science education. It was used in numerous outreach activities such as science fairs. Moreover, it proved to be a great tool for education...
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Solid Oxide Fuel Cells with Ni infiltrated perovskite anode
PublikacjaNiobium-doped strontium titanate was used as the anode for a solid oxide fuel cell. Electrolyte-supported cells were prepared with pure perovskite and composite perovskite–yttria–stabilized-zirconia (YSZ) anodes. Fuel cell tests demonstrated significant improvement in power density after infiltration with a small amount of Ni. The obtained values of power densities are comparable with conventional Ni/YSZ cermet anode. In addition,...
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Determination of causes of accelerated local corrosion of austenitic steels in water supply systems
PublikacjaThis paper concerns an inspection of a water supply system, made of AISI 304 steel, which showed signs of local corrosion at the weld. Such corrosion caused material perforation after very short periods of operation. It was revealed that steel was sensitised during the welding process. It was also proven that chromium micro-segregation occurred in the alloy leading to galvanic cell formation which initialised the process of pitting...
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Relieving the Measuring System of the Trailer for Tyre/Road Rolling Resistance Measurements from the Inertia Force
PublikacjaIn the article the principle of measuring of tyre/road rolling resistance tyres in road conditions applied in a special measuring trailer is presented. This trailer was built in Faculty of Mechanical Engineering at Gdansk University of Technology. The construction of two special devices used in this trailer was discussed. These devices eliminate the influence of some chosen confounding measurements factors such as: the inertia...