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Search results for: electrical properties analysis
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Analysis of Interspike-Intervals for the General Class of Integrate-and-Fire Models with Periodic Drive
PublicationWe study one-dimensional integrate-and-fire models of the general type x˙=F (t, x) and analyze properties of the firing map which iterations recover consecutive spike timings. We impose very week constraints for the regularity of the function F (t, x), e.g. often it suffices to assume that F is continuous. If additionally F is periodic in t, using mathematical study of the displacement sequence of an orientation preserving circle...
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Backscattering properties of southern Baltic herring
PublicationReliable TS(L) relationship is required to improve acoustic algorithms of abundanceestimation of Baltic herring. The relationships, empirically obtained in different parts of theBaltic Sea, produce up to 8 dB – difference in the herring TS. In order to develop an accurateTS(L) relationship, it is important to analyze factors controlling the TS variability. Thepossible impact of the regional difference...
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In-situ Cu-doped MnCo-spinel coatings for solid oxide cell interconnects processed by electrophoretic deposition
PublicationThe Cu doping of the Mn–Co spinel is obtained “in-situ” by electrophoretic co-deposition of CuO and Mn1.5Co1.5O4 powders and subsequent two-step reactive sintering. Cu-doped Mn1.5Co1.5O4 coatings on Crofer22APU processed by electrophoretic co-deposition method are tested in terms of long term oxidation resistance and area specific resistance tests up to 3600 h. The introduction of Cu in the spinel lead to higher level of densification...
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Heterotrophic Anodic Denitrification in Microbial Fuel Cells
PublicationNowadays, pollution caused by energy production systems is a major environmental concern. Therefore, the development of sustainable energy sources is required. Amongst others, the microbial fuel cell (MFC) seems to be a possible solution because it can produce clean energy at the same time that waste is stabilized. Unfortunately, mainly due to industrial discharges, the wastes could contain nitrates, or nitrates precursors such...
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A compartment model of alveolar–capillary oxygen diffusion with ventilation–perfusion gradient and dynamics of air transport through the respiratory tract
PublicationThis paper presents a model of alveolar–capillary oxygen diffusion with dynamics of air transport through the respiratory tract. For this purpose electrical model representing the respiratory tract mechanics and differentia equations representing oxygen membrane diffusion are combined. Relevant thermodynamic relations describing the mass of oxygen transported into the human body are proposed as the connection between these models,...
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New ceramic materials derived from pyrolyzed poly(1,2-dimethylsilazane) and starch as a potential anode for Li-ion batteries
PublicationNewmaterialswere obtained by pyrolysis of starch (S) and poly(1,2-dimethylsilazane) (PSN) (weight ratio: PSN/S 30/70) at temperature a) 500 °C, b) 700 °C and c) 900 °C. Ceramic materials were characterized by infrared spectroscopy, TGA, Raman spectroscopy and SEM. New Si\O and shifted Si\C stretching vibration modes emerged confirming direct interaction between silicon originating fromsilazane and oxygen coming fromstarch. The...
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NEW SOLUTIONS FOR THE SOLAR CHARGE CONTROLLERS DESIGN FOR OBTAINING TRUE MPP IN PARTLY SHADED PV MODULES
PublicationSoft shading sources such as tree limbs, structural elements of buildings and chimneys, scatter and refract sunlight, significantly reducing the amount of radiation reaching the surface of the module. The hard shadings located directly on the surface (i.e. bird droppings, leaves, snow) tend to stop sunlight completely. These phenomena significantly affects the output characteristics of photovoltaic modules and often contribute...
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A gap waveguide-based mechanically reconfigurable phase shifter for high-power Ku-band applications
PublicationThis paper presents a novel design of a low-loss, reconfgurable broadband phase shifter based on groove gap waveguide (GGW) technology. The proposed phase shifter consists of a folded GGW and three bends with a few pins forming the GGW and one bend attached to a movable plate. This movable plate allows for adjustments to the folded waveguide length, consequently altering the phase of electromagnetic waves. The advantage of GGW...
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Ocena stanu chemicznego i zagrożeń wód podziemnych oraz powierzchniowych w rejonie Zalewu Wślanego
PublicationThe purpose of the research was to examine how factors such as land use and land management affect the quality of groundwater and surface water. These studies were possible thanks to funding from the IDUB Technetium Talent Management Grants project titled “Assessment of Anthropogenic Threat to Groundwater and Surface Water in the Region of the Vistula Lagoon”. The research area included a section of the Vistula Spit, ¯u³awy Wielkie...
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Simple 60 GHz Switched Beam Antenna for 5G Millimeter-Wave Applications
PublicationA new 60 GHz band single-input switched beam antenna is proposed for the fifth-generation (5G) millimeter-wave network applications. The presented design is capable of electronically switching the main beam in two different directions via a proposed microstrip-line-to-slotline single-pole dual-throw (SPDT) switch based on commercially available p-i-n diodes. The antenna is fabricated in a low-cost printed circuit board process...
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The Design of Cavity Resonators and Microwave Filters Applying Shape Deformation Techniques
PublicationThis article introduces shape deformation as a new approach to the computer-aided design (CAD) of high-frequency components. We show that geometry deformation opens up new design possibilities and offers additional degrees of freedom in the 3-D modeling of microwave structures. Such design flexibility is highly desirable if the full potential of additive manufacturing (AM) is to be exploited in the fabrication of RF and microwave...
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Influence of the fragment size on the recycling process of thin-film modules based on CdTe
PublicationFor several years, the production of second generation cells (the so-called thin film), produced from amorphous silicon, cadmium telluride (CdTe) or copper indium (gallium) diselenide (CI(G)S), has been increasing. The total number of end-of-life panels by 2050 is expected to reach 9.57 million tonnes. They contain heavy metals that can be leached into the environment at the land field. The EU directive on waste electrical and...
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The impedance of hydrogen oxidation reaction in a proton exchange membrane fuel cell in the presence of carbon monoxide in hydrogen stream
PublicationEvaluation of performance of a proton exchange membrane fuel cell, which is affected by carbon monoxide that pollutes the hydrogen stream, was presented. This influence was studied for carbon monoxide concentration of 125–325 ppb, which are close to values specified in ISO 14687:2019 standard. Performed studies provided crucial information for further development of fuel cell as an energy source for automotive application. Impedance...
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A higher order transversely deformable shell-type spectral finite element for dynamic analysis of isotropic structures
PublicationThis paper deals with certain aspects related to the dynamic behaviour of isotropic shell-like structures analysed by the use of a higher order transversely deformable shell-type spectral finite element newly formulated and the approach known as the Time-domain Spectral Finite Element Method (TD-SFEM). Although recently this spectral approach is reported in the literature as a very powerful numerical tool used to solve various...
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Nonreciprocal properties of elliptical ferrite coupled line junction
PublicationIn this paper the nonreciprocal properties of el-liptical ferrite coupled line (EFCL) junction are examined. In the analysis the technique combining spectral-domain approach (SDA) with coupled-mode method (CMM) is applied. The nu-merical results concerning gyromagnetic coupling coefficient of ferrite coupled lines and scattering matrix of EFCL junction are presented. The obtained results are validated with the use of commercial...
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Analysis
PublicationNew food products and diverse formulations containing the regulated steviol glycoside(s) as well as Stevia extracts or Stevia leaves have been brought on the global market. The upcoming multitude of such food products, but also their falsification and adulteration, does have impact on food analysis. Robust high-throughput methods that cope with different food matrices are required for food control to ensure food safety. The analysis...
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Application of Multivariate Analysis Methods in Welding Engineering
PublicationPhenomena and processes taking place during welding are usually very complex and, for this reason, should be described using multivariate methods. The article discusses the methodological basis and selected application areas as regards the solving of welding problems using statistical multivariate methods. In addition, the article presents exemplary applications of the design of experiment, multiple regression analysis, cluster...
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Mechanical properties of the human stomach under uniaxial stress action
PublicationThe aim of this study was to estimate the range of mechanical properties of the human stomach in order to use the collected data in numerical modelling of surgical stapling during resections of the stomach. The biomedical tests were conducted in a self-developed tensile test machine. Twenty-two fresh human stomach specimens were used for the experimental study of its general strength. The specimens were obtained from morbidly obese...
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Properties of the triset metric for phylogenetic trees
Publicationthe following paper presents a new polynomial time metric for unrootedphylogenetic trees (based on weighted bipartite graphs and the method ofdetermining a minimum perfect matching) and its properties. also many its properties are presented.
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Green adsorbents and solvents in food analysis
PublicationGreen analytical chemistry aims to minimize the negative impact of analytical procedures on the environment and human health. This can be achieved through the use of non-toxic and environmentally friendly reagents. Classical green solvents include water, ethanol, acetone, and supercritical fluids. Water has been used for the extraction of water-soluble compounds (sugars, amino acids). Ethanol and acetone have been used for the...
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Electrohydrodynamic Flow Patterns in a Narrow Electrostatic Precipitator with Longitudinal Wire Electrode for Various Electrode Geometries
PublicationRecently narrow electrostatic precipitators (ESPs) have become a subject of interest because of their possible application in diesel engines. In this paper results of 2-dimensional (2D) Particle Image Velocimetry (PIV) measurements of the flow patterns in a narrow ESP for a various electrode geometries are presented. The PIV measurements were carried out in the observation plane that is perpendicular to the ESP duct. The ESP was...
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Tuftsin-Properties and Analogs
PublicationImmunomodulation is one of the significant therapeutic strategies. It includes both stimulation or suppression of the immune system by a variety of substances called immunomodulators, designed to regulate the immune response of the organism to infections of varying etiology. An example of such a substance is tuftsin (TKPA) 3 (Fig. (1)). Tuftsin is an endogenous immunomodulator of a wide spectrum of biological activity. Tetrapeptide...
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Smart Weighing Scale with Feet-Sampled ECG
PublicationIn a smart home, health and well-being monitoring systems could be embedded in everyday devices providing a pervasive care. A home bathroom scale is an example of such a device, typically used to measure body weight and very often its composition (e.g. body water/fat percentage). In this paper, we analyzed a potential use of the bathroom scale to measure electrocardiogram (ECG) from electrodes located on the scale's tile. In particular...
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Size reduction of ultra-wideband antennas with efficiency and matching constraints
PublicationAntenna design is a multifaceted task that involves handling of various performance figures concerning both electrical performance of the structure as well as its geometry. Simultaneous control of several objectives through rigorous optimization is very challenging and virtually impossible through conventional approaches such as parameter sweeping. In this work, we investigate size reduction of ultra‐wideband antenna structures...
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Rapid Simulation-Driven Multiobjective Design Optimization of Decomposable Compact Microwave Passives
PublicationIn this paper, a methodology for fast multiobjective optimization of the miniaturized microwave passives has been presented. Our approach is applicable to circuits that can be decomposed into individual cells [e.g., compact microstrip resonant cells (CMRCs)]. The structures are individually modeled using their corresponding equivalent circuits and aligned with their accurate, EM simulated...
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Water Solubilization Using Nonionic Surfactants from Renewable Sources in Microemulsion Systems
PublicationIn this study the effect of temperature, NaCl andoils (hydrocarbons: C8-C16) on the formation and solubilizationcapacity of the systems of oil/monoacylglycerols(MAG):ethoxylated fatty alcohols (CEO20)/propylene glycol(PG)/water was investigated. The effects of the surfactantmixture on the phase behavior and the concentration ofwater or oil in the systems were studied at three temperatures(50, 55, 60 C) and with varied NaCl solutions...
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The use of LiFePO4 technology in autonomous PV systems
PublicationBattery manufacturing based on the flow of lithium ions is currently the fastest growing and the most promising technology. It is used in many applications - from the smallest electronic devices to the large-scale energy trays. However, in the PV systems lead-acid batteries are still the most commonly used. As they are much cheaper they also come with a number of significant disadvantages. It is anticipated that they will be replaced...
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Wavelet transform-based approach to defect identification in railway carbon contact strips.
PublicationPantographs of electric rail vehicles are fitted with carbon contact strips, which slide along the contact wire of catenary to provide constant electrical contact. Contact strips are exposed to wear and damages. Using damaged contact strips significantly increases the risk of catenary rupture. Therefore, their technical condition has to be inspected frequently. In previous work a 3D laser scanning system was proposed for recording...
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Experimental research on helical coil biomass boiler with oil as a heating fluid
PublicationThis paper presents an experimental research of helical coil biomass boiler with thermal oil heating agent. Heat exchanger consists of two coaxial helical coils swept by the flue gases. The burner is a single vertical retort connected to the fuel tank (wooden pellets). The boiler is a part of micro-power plant in which the heat from the boiler is exchanged with low-boiling HFE7100 to produce steam for a custom steam turbine. The...
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A stochastic approach for the solution of single and multi – objective optimisation problems of biological processes in sequencing batch reactor
PublicationThis paper investigates the impact of implementing single and multi-optimisation solutions on the biological treatment process in a sequencing batch reactor (SBR). The research is based on a case study of the water resource recovery facility (WRRF) in Swarzewo, Northern Poland. The paper introduces the adaptive extremum seeking control (ESC) method for dissolved oxygen (DO) concentration control and places it in a layered control structure....
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Active Control of Highly Autocorrelated Machinery Noise in Multivariate Nonminimum Phase Systems
PublicationIn this paper, a novel multivariate active noise control scheme, designed to attenuate disturbances with high autocorrelation characteristics and preserve background signals, is proposed. The algorithm belongs to the class of feedback controllers and, unlike the popular feedforward FX-LMS approach, does not require availability of a reference signal. The proposed approach draws its inspiration from the iterative learning control...
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How Can We Identify Electrophysiological iEEG Activities Associated with Cognitive Functions?
PublicationElectrophysiological activities of the brain are engaged in its various functions and give rise to a wide spectrum of low and high frequency oscillations in the intracranial EEG (iEEG) signals, commonly known as the brain waves. The iEEG spectral activities are distributed across networks of cortical and subcortical areas arranged into hierarchical processing streams. It remains a major challenge to identify these activities in...
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Optimization of Train Energy Cooperation Using Scheduled Service Time Reserve
PublicationThe main aim of the paper was to develop an innovative approach to the preliminary estimation possibility of train energy cooperation based on data from timetables, without traction calculations. The article points out the need to strive for sustainable and environmentally friendly transport. It was pointed out that rail transport using electric traction is one of the more ecological branches of transport. It also offers a number...
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Modeling of Electrified Transportation Systems Featuring Multiple Vehicles and Complex Power Supply Layout
PublicationThe paper proposes a novel approach to modeling electrified transportation systems. The proposed solution reflects the mechanical dynamics of vehicles as well as the distribution and losses of electric supply. Moreover, energy conversion losses between the mechanical and electrical subsystems and their bilateral influences are included. Such a complete model makes it possible to replicate, e.g., the impact of voltage drops on vehicle...
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Family Tree for Aqueous Organic Redox Couples for Redox Flow Battery Electrolytes: A Conceptual Review
PublicationRedox flow batteries (RFBs) are an increasingly attractive option for renewable energy storage, thus providing flexibility for the supply of electrical energy. In recent years, research in this type of battery storage has been shifted from metal-ion based electrolytes to soluble organic redox-active compounds. Aqueous-based organic electrolytes are considered as more promising electrolytes to achieve “green”, safe, and low-cost...
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Numerically Efficient Miniaturization-Oriented Optimization of an Ultra-Wideband Spline-Parameterized Antenna
PublicationDesign of ultra-wideband radiators for modern handheld applications is a challenging task that involves not only selection of an appropriate topology, but also its tuning oriented towards balancing the electrical performance and size. In this work, a low-cost design of a compact, broadband, spline-parameterized monopole antenna has been considered. The framework used for the structure design implements trust-region-based methods,...
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Factors Affecting the Rheological Properties of Foods
PublicationIn this chapter, engineering aspects concerning real body mechanics and the impact of respective food ingredients on said properties are presented together. Food is a complex matrix and each of macro and micro ingredients plays its role in the formation of rheologic properties, and minor changes in the basic ingredient structure may affect the change of these properties significantly. Basic analytic techniques are presented for...
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Comparative analysis of coaxial magnetocumulative generators
PublicationThis paper presents the results of a computer simulation of coaxial magnetocumulative current generators (MCGs). The simulation tests were carried out for different values of the internal diameter, length and speed of the deformation of the MGP element.
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Finite element modelling of a historic church structure in the context of a masonry damage analysis
PublicationThe paper includes a case study of modelling a real historic church using the finite element method (FEM) based on laser scans of its geometry. The main goal of the study was the analysis of the causes of cracking and crushing of masonry walls. An FEM model of the structure has been defined in ABAQUS. A non-linear dynamic explicit analysis with material model including damage plasticity has been performed. A homogenization procedure...
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Antioxidant properties of ferrous flavanol mixtures
PublicationInteraction of metal, especially iron ions with flavanols is considered as an important feature of these compounds and is believed to contribute to their both antioxidant and prooxidant properties. The aim of this study was to examine how Fe2+ binding to form a 4:1 (flavanol:Fe2+) mixtures affects the antioxidant properties of flavanols. ABTS∗ scavenging, protection against fluorescence bleaching induced by AAPH and hypochlorite,...
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Rhodotorulic Acid and its Derivatives: Synthesis, Properties, and Applications
PublicationSiderophores are low molecular weight compounds produced by microorganisms to scavenge iron in iron-deficient environments. Rhodotorulic acid, a natural hydroxamate siderophore, plays a vital role in iron acquisition for fungi and bacteria. As the simplest natural hydroxamate siderophore, it exhibits a high affinity for ferric ions, enabling it to form stable complexes that facilitate iron uptake and transport within microorganisms....
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Comparative Study of the Reinforcement Type Effect on the Thermomechanical Properties and Burning of Epoxy-Based Composites
PublicationAramid (AF), glass (GF), carbon (CF), basalt (BF), and flax (FF) fibers in the form of fabrics were used to produce the composites by hand-lay up method. The use of fabrics of similar grammage for composites’ manufacturing allowed for a comprehensive comparison of the properties of the final products. The most important task was to prepare a complex setup of mechanical and thermomechanical properties, supplemented by fire behavior...
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On analysis of nanocomposite conical structures
PublicationThis research examines the analysis of rotating truncated conical baskets reinforced by carbon nanotubes around the two independent axes. A time-dependent analysis is considered, and the nonlinear dynamic governing equations are extracted using the energy method. Carbon nanotubes (CNTs) reinforced the conical basket, and the structure's mechanical properties are determined based on the several distributions of carbon nanotubes....
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Analytical applications of smartphones for agricultural soil analysis
PublicationSoil is one of the most important farming resources. Appropriate managing of its quality promotes productive and sustainable agriculture. The valuable farm practice in soil quality managing is based on regular soil analysis with the aim to determine the exact amount of nutrients or other chemical, physical and biological soil properties. Soil analysis usually requires samples collection at desired sampling depth following by samples...
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Stateczność i niezawodność pełnomorskich platform wiertniczych
PublicationW pracy przedstawiono wieloletnie doświadczenia Autora w zakresie wybranych aspektów numerycznej analizy pełnomorskich platform wiertniczych, w szczególności stacjonarnych platform stalowych poddanych działaniu fal wiatrowych i wiatru. W opisie zachowania się platform uwzględniono współoddziaływanie trzech ośrodków: materiału konstrukcji, morskich fal wiatrowych i podłoża gruntowego. Przyjęcie do opisu stochastycznych właściwości...
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Combined thrust radial bearing of a submarine main shaft – Design and analysis of failure
PublicationThis paper presents an analysis of the combined thrust radial bearing of a submarine propulsion shaft. The lubrication system of the bearing is based on a fixed ring. The efficiency of the lubrication system depends on the shaft speed and temperature, which affects oil viscosity. In turn, the thrust bearing load also depends on the rotational speed of the shaft, because as the speed increases, the drag of the ship increases simultaneously,...
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Effect of Coating Material Properties on Tilting-pad Thrust Bearing Performance
PublicationPolymer lined tilting-pad bearings demonstrate many advantages over traditional bearing systems. Bearings with a polymer layer in comparison with a babbitted layer show, for example: lower value of friction coefficient (important during start/stops), higher fatigue strength of the coating, better distribution of the load on individual pads due to lower elasticity of the polymers, wider range of operational temperatures or the ability...
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Thermal and physical properties of ZrO2–AlO(OH) nanopowders synthesised by microwave hydrothermal method
PublicationIndustrially relevant nanopowder was synthesised by microwave hydrothermal synthesis to obtain well-controlled composition (ZrO2–AlO(OH) system) which was found to determine a number of physical and thermal characteristics. This study reports variation of particle size, density, specific surface area (SSABET), as well as thermal behaviour of nanopowder mixtures of ZrO2–AlO(OH) in the whole range of compositions. It was found that...
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Wear estimation of current collector contact strips by analysis of a 3D scanning results
PublicationThe technical condition of current collector contact strips is very important when operational reliability of railway transportation is considered. The authors proposed a novel measurement system based on a 3D camera to register the shape and dimensions of the current collector contact strips surface. The system was installed above the railway track for tests in target ambient. During the trial operation a few dozen of contact...
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Application and mechanical properties of aluminium alloys
PublicationThe paper presents a short survey of the application and mechanical properties of aluminium alloys. This area of scientific research is still developing, the authors restricted it to about 30 papers. Numerical simulations of the aluminium bracket are also investigated. The authors propose a solution to increase the load capacity of aluminium brackets with application of the additional cover plates. This study is proposed as an...