Search results for: ULTRA WIDEBAND ANTENNAS
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Expedited Globalized Antenna Optimization by Principal Components and Variable-Fidelity EM Simulations: Application to Microstrip Antenna Design
PublicationParameter optimization, also referred to as design closure, is imperative in the development of modern antennas. Theoretical considerations along with rough dimension adjustment through supervised parameter sweeping can only yield initial designs that need to be further tuned to boost the antenna performance. The major challenges include handling of multi-dimensional parameter spaces while accounting for several objectives and...
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Reliable Surrogate Modeling of Antenna Input Characteristics by Means of Domain Confinement and Principal Components
PublicationA reliable design of contemporary antenna structures necessarily involves full-wave electromagnetic (EM) analysis which is the only tool capable of accounting, for example, for element coupling or the effects of connectors. As EM simulations tend to be CPU-intensive, surrogate modeling allows for relieving the computational overhead of design tasks that require numerous analyses, for example, parametric optimization or uncertainty...
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The supramolecular organization of self-assembling chlorosomal bacteriochlorophyll c, d, or e mimics
PublicationBacteriochlorophylls (BChls) c, d, and e are the main light-harvesting pigments of green photosynthetic bacteria that self-assemble into nanostructures within the chlorosomes forming the most efficient antennas of photosynthetic organisms. All previous models of the chlorosomal antennae, which are quite controversially discussed because no single crystals could be grown so far from these organelles, involve a strong hydrogen-bonding...
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Filter-Hilbert Method for Automatic Correction of Non-Anechoic Antenna Measurements with Embedded Self-Calibration Mechanism
PublicationOne of the most important steps in the process of antenna development involves measurements of its prototype. Far-field performance of radiators is normally characterized in strictly controlled environments such as anechoic chambers which can ensure certification-grade accuracy. Unfortunately, they are also characterized by high construction costs which might not be justified for low-budget research and/or teaching-related activities....
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A Compact Basis for Reliable Fast Frequency Sweep via the Reduced-Basis Method
PublicationA reliable reduced-order model (ROM) for fast frequency sweep in time-harmonic Maxwell’s equations by means of the reduced-basis method is detailed. Taking frequency as a parameter, the electromagnetic field in microwave circuits does not arbitrarily vary as frequency changes, but evolves on a very low-dimensional manifold. Approximating this low-dimensional manifold by a low dimension subspace, namely, reduced-basis space, gives...
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Compressive Sensing Approach to Harmonics Detection in the Ship Electrical Network
PublicationThe contribution of this paper is to show the opportunities for using the compressive sensing (CS) technique for detecting harmonics in a frequency sparse signal. The signal in a ship’s electrical network, polluted by harmonic distortions, can be modeled as a superposition of a small number of sinusoids and the discrete Fourier transform (DFT) basis forms its sparse domain. According to the theory of CS, a signal may be reconstructed...
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Rapid Multi-Criterial Antenna Optimization by Means of Pareto Front Triangulation and Interpolative Design Predictors
PublicationModern antenna systems are designed to meet stringent performance requirements pertinent to both their electrical and field properties. The objectives typically stay in conflict with each other. As the simultaneous improvement of all performance parameters is rarely possible, compromise solutions have to be sought. The most comprehensive information about available design trade-offs can be obtained through multi-objective optimization...
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High frequency impulse ground penetrating radar application in assessment of interlayer connections
PublicationGround Penetrating Radar (GPR) technique is commonly used in the nondestructive evaluation of pavement structures. In particular, this method is used to estimate thicknesses of pavement layers as well as it can be utilized in advanced studies of pavement structures. The device presented in this paper comprise the high frequency impulse antennas that allow for investigating the interlayer zones in terms of their electromagnetic...
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Generalized Pareto ranking bisection for computationally feasible multi-objective antenna optimization
PublicationMulti-objective optimization (MO) allows for obtaining comprehensive information about possible design trade-offs of a given antenna structure. Yet, executing MO using the most popular class of techniques, population-based metaheuristics, may be computationally prohibitive when full-wave EM analysis is utilized for antenna evaluation. In this work, a low-cost and fully deterministic MO methodology is introduced. The proposed generalized...
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Multi-objective design optimization of antenna structures using sequential domain patching with automated patch size deter-mination
PublicationIn this paper, a simple yet efficient and reliable technique for fully automated multi-objective design optimization of antenna structures using sequential domain patching (SDP) is discussed. The optimization procedure according to SDP is a two-step process: (i) obtaining the initial set of Pareto-optimal designs representing the best possible trade-offs between considered conflicting objectives, and (ii) Pareto set refinement...
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Model Management for Low-Computational-Budget Simulation-Based Optimization of Antenna Structures Using Nature-Inspired Algorithms
PublicationThe primary objective of this study is investigation of the possibilities of accelerating nature-inspired optimization of antenna structures using multi-fidelity EM simulation models. The primary methodology developed to achieve acceleration is a model management scheme which the level of EM simulation fidelity using two criteria: the convergence status of the optimization algorithm, and relative quality of the individual designs...
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High gain/bandwidth off‑chip antenna loaded with metamaterial unit‑cell impedance matching circuit for sub‑terahertz near‑field electronic systems
PublicationAn innovative off-chip antenna (OCA) is presented that exhibits high gain and efficiency performance at the terahertz (THz) band and has a wide operational bandwidth. The proposed OCA is implemented on stacked silicon layers and consists of an open circuit meandering line. It is shown that by loading the antenna with an array of subwavelength circular dielectric slots and terminating it with a metamaterial unit cell, its impedance...
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Phototransformation of Amlodipine: Degradation Kinetics and Identification of Its Photoproducts
PublicationNowadays, monitoring focuses on the primary compounds and does not include degradation products formed during various biological and chemical processes. Transformation products may have the same effects to human health and the environment or sometimes they can be more toxic than the parent compound. Unfortunately, knowledge about the formation of degradation products is still limited, however, can be very important for the environmental...
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Fast GC as a useful tool for authenticity assessment of kiwifruit
PublicationKiwifruit is one of the healthiest fruits due to its high content of biologically active substances and nutrients. The most popular species of Actinidia (kiwifruit) are the Actinidia deliciosa fruits called kiwi and Actinidia chinensis commonly called golden kiwi, while the lesser known species is Actinidia arguta known as mini kiwi. Bioactivities and nutrients of Actinidia are influenced by species and cultivars. It is very important...
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Hyperelastic Microcantilever AFM: Efficient Detection Mechanism Based on Principal Parametric Resonance
PublicationThe impetus of writing this paper is to propose an efficient detection mechanism to scan the surface profile of a micro-sample using cantilever-based atomic force microscopy (AFM), operating in non-contact mode. In order to implement this scheme, the principal parametric resonance characteristics of the resonator are employed, benefiting from the bifurcation-based sensing mechanism. It is assumed that the microcantilever is made...
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Photocatalytic hydrogen evolution from glycerol-water mixture under visible light over zinc indium sulfide (ZnIn2S4) nanosheets grown on bismuth oxychloride (BiOCl) microplates
PublicationZnIn2S4 (ZIS) is one of the widely studied photocatalyst for photocatalytic hydrogen evolution applications due to its prominent visible light response and strong reduction ability. However, its photocatalytic glycerol reforming performance for hydrogen evolution has never been reported. Herein, the visible light driven BiOCl@ZnIn2S4 (BiOCl@ZIS) composite was synthesized by growth of ZIS nanosheets on a template-like hydrothermally...
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Enhanced-Performance Circularly Polarized MIMO Antenna with Polarization/Pattern Diversity
PublicationDesign of a compact wideband circularly polarized (CP) multiple-input multiple-output (MIMO) antenna with polarization diversity is proposed and characterized for off-body communication. The antenna is based on a simple coplanar waveguide (CPW)-fed monopole extension of the microstrip line. The orthogonal field components required by CP are induced using a simply modified right/left side ground plane. In particular, a stub extending...
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THE APPLICATION EFFECTS OF CONTINUOUS SATELLITE MEASUREMENTS OF RAILWAY LINES
PublicationThe paper presents results of satel lite surveying of the railway's rout es, which have been conducted just after starting in Poland (in 2008) the Active Geodesy Network ASG-EU POS. Afterwards it was possible to effectively utilize the GNSS survey ing results for the inventory of the (exploring) railways in service. Already at the beginning of 2009, the research team from Gdansk University of Technology and Naval Academy in Gdynia,...
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Low-cost multi-objective optimization and experimental validation of UWB MIMO antenna
PublicationPurpose–The purpose of this paper is to validate methodologies for expedited multi-objective designoptimization of complex antenna structures both numerically and experimentally.Design/methodology/approach–The task of identifying the best possible trade-offs between theantenna size and its electrical performance is formulated as multi-objective optimization problem.Algorithmic frameworks are described for finding Pareto-optimal...
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Computationally Efficient Design Optimization of Compact Microwave and Antenna Structures
PublicationMiniaturization is one of the important concerns of contemporary wireless communication systems, especially regarding their passive microwave components, such as filters, couplers, power dividers, etc., as well as antennas. It is also very challenging, because adequate performance evaluation of such components requires full-wave electromagnetic (EM) simulation, which is computationally expensive. Although high-fidelity EM analysis...
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Expedited Metaheuristic-Based Antenna Optimization Using EM Model Resolution Management
PublicationDesign of modern antenna systems heavily relies on numerical opti-mization methods. Their primary purpose is performance improvement by tun-ing of geometry and material parameters of the antenna under study. For relia-bility, the process has to be conducted using full-wave electromagnetic (EM) simulation models, which are associated with sizable computational expendi-tures. The problem is aggravated in the case of global optimization,...
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A Low-Cost System for Far-Field Non-Anechoic Measurements of Antenna Performance Figures
PublicationPrototype measurements are the key step in the development of antenna structures. Typically, their far-field characteristics are validated in expensive, dedicated facilities such as open range sites, or anechoic chambers. Despite being necessary for obtaining high-precision data (e.g., for device qualification), the use of costly infrastructure might not be fully justified when the main goal of measurements includes demonstration...
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Dual-band Millimetre Wave MIMO Antenna with Reduced Mutual Coupling Based on Optimized Parasitic Structure and Ground Modification
PublicationIn this study, a high-isolation dual-band (28/38 GHz) multiple-input–multiple-output (MIMO) antenna for 5G millimeter-wave applications is presented. The antenna consists of two interconnected patches. The primary patch is connected to the inset feed, while the secondary patch is arc-shaped and positioned over the main patch, opposite to the feed. Both patches function in the lower 28 GHz band, while the primary patch is accountable...
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ENVIRONMENTALLY FRIENDLY MATERIALS IN ARCHITECTURE � MODERN TRENDS AND DEVELOPMENT DIRECTIONS
PublicationFor a long time the interest in environmentally friendly materials in architecture is no longer limited to the use of renewable and natural substances such as wood, stone, straw, or reusable materials, such as metals or glass. Today the so-called naturals and the materials compatible with the idea of sustainability constantly appear on the market in new forms. Increasing awareness of the necessity to limit the building sector’s...
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The role of aluminium in metal–organic frameworks derived carbon doped with cobalt in electrocatalytic oxygen evolution reaction
PublicationWater electrolysis is one of the most crucial processes in the development of new energy sources, where ultra-clean fuel is produced - hydrogen. Oxygen evolution reaction (OER) is the sluggish process of overall water splitting. Therefore, this study presents the design, characterization and electrochemical study of cobalt-based electrocatalysts embedded into porous carbons derived from an Al-metal–organic...
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Research on Tool Temperature Dependence on Lapping Grains Size
PublicationCommonly used as a finishing operation, lapping has been used for achieving ultra-high finishes and close tolerances between mating pieces. Its carried out by applying loose abrasive grains between work and lap surfaces, and causing a relative motion between them resulting in a finish of multi-directional lay. The grains activity (sliding and rolling) in the working gap causes not only the material removal but also the temperature...
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Chemical and biological characterization of Ocimum basilicum L. phenolic extract and essential oil derived through ultrasound and microwave-assisted extraction techniques
PublicationPlant-derived bioactive molecules are increasingly utilized in food processing as natural additives, driven by a growing interest in healthier lifestyles. This trend has spurred industries to reformulate products to meet the demands of health-conscious consumers. This study investigates the phenolic extract and essential oil of O. basilicum L. obtained via ultrasound-assisted extraction and microwave-assisted extraction, respectively. Characterization...
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Electrochemical detection of bacterial endotoxin lipopolysaccharide (LPS) on gold electrode modified with DAL-PEG-DK5-PEG-OH - Antimicrobial peptide conjugate
PublicationThis work describes fabrication of gold electrodes modified with peptide conjugate DAL-PEG-DK5-PEG-OH that enables ultra-sensitive detection of lipopolysaccharide (LPS) isolated from the reference strain of Escherichia coli O26:B6. The initial step of the established procedure implies immobilization of the fully protected DAL-PEG-DK5-PEG-OH peptide on the surface of the gold electrode previously modified by cysteamine. Then side...
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Performance of the Direct Sequence Spread Spectrum Underwater Acoustic Communication System with Differential Detection in Strong Multipath Propagation Conditions
PublicationThe underwater acoustic communication (UAC) operating in very shallow-water should ensure reliable transmission in conditions of strong multipath propagation, significantly disturbing the received signal. One of the techniques to achieve this goal is the direct sequence spread spectrum (DSSS) technique, which consists in binary phase shift keying (BPSK) according to a pseudo-random spreading sequence. This paper describes the DSSS...
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Optimization-Based Robustness Enhancement of Compact Microwave Component Designs with Response Feature Regression Surrogates
PublicationThe ability to evaluate the effects of fabrication tolerances and other types of uncertainties is a critical part of microwave design process. Improving the immunity of the device to parameter deviations is equally important, especially when the performance specifications are stringent and can barely be met even assuming a perfect manufacturing process. In the case of modern miniaturized microwave components of complex topologies,...
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Investigation of environmental influences to the precise GNNS solutions
PublicationThe results presented in this paper concern investigation of environmental influences to GNNS coordinates on the example of ASG-EUPOS network. The problem of the impact of environmental effects is crucial for observing gravity. Satellite systems are not as susceptible to changes in local hydrology or atmospheric effects, although significant influences are clearly visible in the change of coordinates. The authors analyzed daily...
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On Improved-Reliability Design Optimization of High-Frequency Structures Using Local Search Algorithms
PublicationThe role of numerical optimization has been continuously growing in the design of high-frequency structures, including microwave and antenna components. At the same time, accurate evaluation of electrical characteristics necessitates full-wave electromagnetic (EM) analysis, which is CPU intensive, especially for complex systems. As rigorous optimization routines involve repetitive EM simulations, the associated cost may be significant....
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Chemiluminogenic acridinium salts: A comparison study. Detection of intermediate entities appearing upon light generation
PublicationThe nine derivatives of acridine-9-carboxylic acid (CMADs) capable for chemiluminescence (CL), representing various classes of compounds were isolated in a chemically pure state (assessed by RP-HPLC) and identified using high resolution mass spectrometry (ESI-QTOF) and magnetic resonance (1H NMR) techniques. Among them are aryl acridinium esters, containing certainly selected and located substituents in both aromatic systems, an...
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Tribo-Environment Dependent Chemical Modification of Sliding Interfaces in Ultrananocrystalline Diamond Nanowall Film: A Correlation with Friction and Wear
PublicationTribological properties of ultrananocrystalline diamond nanowall (UNCD NW) films were investigated quantitatively in three different and controlled tribo-environmental conditions, proposing the passivation and graphitization mechanisms. However, these mechanisms are rather complicated and possibly can be understood in well-controlled tribological conditions. It was shown that the friction and wear of these films were high in highPage 1...
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Influence of PWHT Parameters on the Mechanical Properties and Microstructural Behavior of Multi-Pass GTAW Joints of P92 Steel
PublicationThe 9% Cr steels were developed for ultra-supercritical (USC) power plants to meet the requirements of high operating temperature and pressure. These steels are produced to operate at high temperatures where impact toughness is not a concern; however, it becomes important for the welded joints to have good impact toughness at room temperature for manufacturing. The present work investigates the effect of the post-weld heat treatment...
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A dissimilar welded joint of grade 92 steel and AISI 304L steel obtained using IN82 buttering and IN617 fller: relationship of microstructure and mechanical properties
PublicationUnfavourable operating conditions of equipment in the energy industry resulting from high-temperature loads determine the need to use special materials and technological solutions, including welding procedures. In this article, buttering using IN82 (ERNiCr-3) consumables was proposed as a method to improve the weldability of grade 92 steel joined by the gas tungsten arc welding (GTAW) process with AISI 304L (IN617 fller). The...
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Recent advances in high-frequency modeling by means of domain confinement and nested kriging
PublicationDevelopment of modern high-frequency components and circuits is heavily based on full-wave electromagnetic (EM) simulation tools. Some phenomena, although important from the point of view of the system performance, e.g., EM cross-coupling effects, feed radiation in antenna arrays, substrate anisotropy, cannot be adequately accounted for using simpler means such as equivalent network representations. Consequently, the involvement...
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Recent Advances in Accelerated Multi-Objective Design of High-Frequency Structures using Knowledge-Based Constrained Modeling Approach
PublicationDesign automation, including reliable optimization of engineering systems, is of paramount importance for both academia and industry. This includes the design of high-frequency structures (antennas, microwave circuits, integrated photonic components), where the appropriate adjustment of geometry and material parameters is crucial to meet stringent performance requirements dictated by practical applications. Realistic design has...
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Cost-Efficient EM-Driven Size Reduction of Antenna Structures by Multi-Fidelity Simulation Models
PublicationDesign of antenna systems for emerging application areas such as the Internet of Things (IoT), fifth generation wireless communications (5G), or remote sensing, is a challenging endeavor. In addition to meeting stringent performance specifications concerning electrical and field properties, the structure has to maintain small physical dimensions. The latter normally requires searching for trade-off solutions because miniaturization...
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Dimensionality-Reduced Antenna Modeling with Stochastically Established Constrained Domain
PublicationOver the recent years, surrogate modeling methods have become increasingly widespread in the design of contemporary antenna systems. On the one hand, it is associated with a growing awareness of numerical optimization, instrumental in achieving high-performance structures. On the other hand, considerable computational expenses incurred by massive full-wave electromagnetic (EM) analyses, routinely employed as a major design tool,...
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Badanie i analiza dokładności estymacji położenia obiektów ruchomych w hybrydowym systemie lokalizacyjnym
PublicationW niniejszej rozprawie dyskusji poddano dokładność lokalizacji poruszających się osób w środowiskach wewnątrzbudynkowych. W świetle bieżących oczekiwań służb państwowych, czy też podmiotów gospodarczych znajomość położenia osób wewnątrz budynków jest niezwykle ważna, lecz jego określenie jest problematyczne np. z racji utrudnionej propagacji sygnałów radiowych. W rozprawie przedstawiono propozycję budowy hybrydowego systemu lokalizacyjnego,...
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An experimental assessment on a diesel engine powered by blends of waste-plastic-derived pyrolysis oil with diesel
PublicationThe utilization of plastic solid wastes for sustainable energy production is a crucial aspect of the circular economy. This study focuses on pyrolysis as an effective method to convert this feedstock into renewable drop-in fuel. To achieve this, it is essential to have a comprehensive understanding of feedstock composition, pyrolysis process parameters, and the physicochemical characteristics of the resulting fuel, all correlated...
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The luminescence study of Sc2(1–x)Ga2xO3:Cr3+/4+ coumpounds
Open Research DataThe growing interest in the use of near-infrared (NIR) radiation for spectroscopy, optical communication, and medical applications spanning both NIR-I (700–900 nm) and NIR-II (900–1700 nm) has driven the need for new NIR light sources. NIR phosphor-converted light-emitting diodes (pc-LEDs) are expected to replace traditional lamps mainly due to their...
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Analysis of the Possibility of Using New Types of Protective Coatings and Abrasion-Resistant Linings under the Operating Conditions of the Spiral Classifier at KGHM Polska Miedź S.A. Ore Concentration Plant
PublicationA study was carried out to select the appropriate coatings for corrosion protection of the spiral classifier working at KGHM Polska Miedź S.A. Ore Concentration Plant. The abrasion resistance of selected protective coatings and wear-resistant linings was investigated using a DT-523 rotary abrasion tester with Taber CS-10 rubber abrasive discs. The average weight loss of the coatings after a cycle of 2000 revolutions was determined....
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Marek Czachor prof. dr hab.
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Zastosowanie techniki LC-MS/MS oraz biotestów w analityce próbek środowiskowych w celu oznaczenia ich potencjału endokrynnego i zawartości wybranych związków endokrynnych
PublicationWyniki wielu badań prowadzonych w przeciągu ostatnich lat mogą stanowić podstawę do stwierdzenia, że zanieczyszczenia emitowane do środowiska ze źródeł antropogennych mogą stanowić kolejny rodzaj zagrożenia, z którego nie zdawano sobie sprawy wcześniej. Zanieczyszczeniami takimi są substancje z grupy EDC definiowane jako jakikolwiek czynnik, który wpływa na syntezę, wydalanie, transport, wiązanie, działanie lub wydalanie hormonów...
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Microstructure and mechanical properties of a dissimilar metal welded joint of Inconel 617 and P92 steel with Inconel 82 buttering layer for AUSC boiler application
PublicationThe application of the novel dissimilar metal welded (DMW) joint, utilizing Inconel 617 and P92 steel, was showcased in the advanced ultra-supercritical (AUSC) boiler. The work has been performed to investigate the effect of Inconel 82 (ERNiCr-3) buttering layer on microstructure and mechanical properties (high-temperature tensile strength, impact strength and microhardness) of gas tungsten arc welded (GTAW) dissimilar joint between...
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Ryszard Woźniak dr inż.
PeopleRyszard Woźniak received his M.Sc. (1984) from the Lublin University of Technology specializing in Cars and Tractors. In 2002, at the Gdansk University of Technology he defended his doctoral thesis on: "Tyre/road noise when large longitudinal forces are applied in tyre/road contact patch" and obtained a doctorate degree in technical sciences in the field of construction and operation of machines. Currently he is an adjunct at the...
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SECREDAS Cyber Security for Cross Domain Reliable Dependable Automated Systems
ProjectsProject realized in Department of Microwave and Antenna Engineering according to 783119 — SECREDAS agreement from 2018-05-18