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Single-phase product obtained via crude glycerine depolymerisation of polyurethane elastomer: structure characterisation and rheological behaviour
PublicationPolyurethane recycling is a topic of growing interest due to the increasing amount of polyurethanewaste. The main purpose of polyurethane feedstock recycling is to recover the starting polyol, a valuable material. In thiswork, amethod of polyurethane thermo-chemical recycling, glycerolysisbymeansof crude glycerine, is proposed. Themaineffort is focusedonthe employment of crude glycerine without purification from biodiesel production...
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Advanced Hysteretic Model of a Prototype Seismic Isolation System Made of Polymeric Bearings
PublicationThe present paper reports the results of acomprehensive study designed to verify the effectiveness of an advanced mathematical model in simulating the complex mechanical behaviour of a prototype seismic isolation system made of polymeric bearings (PBs). Firstly, in order to construct the seismic bearings considered in this research, a specially prepared flexible polymeric material with increased damping properties was employed....
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Rheology of potato starch chemically modified with microwave-assisted reactions
PublicationNative potato starch was sulfated, selenated, borated, silicated and zincatated by means of microwave-assisted reactions with varying doses of relevant reagents. Resulting products were characterized involving rheological behavior of pastes, their weight-average molecular weight (Mw), and radius of gyration (Rg). Most of the pastes showed shear-thinning behavior, with the flow behavior index (n) below unity. The pastes of starch...
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Comparative analysis of mechanical conditions in bone union following first metatarsophalangeal joint arthrodesis with varied locking plate positions: A finite element analysis
PublicationFirst metatarsophalangeal joint arthrodesis is a typical medical treatment performed in cases of arthritis or joint deformity. The gold standard for this procedure is arthrodesis stabilisation with the dorsally positioned plate. However, according to the authors’ previous studies, medially positioned plate provides greater bending stiffness. It is worth to compare the mechanical conditions for bone formation in the fracture callus...
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Ground lemon and stevia leaves as renewable functional fillers with antioxidant activity for high-density polyethylene composites
PublicationThe development of new sustainable material solutions in the processing of thermoplastic polymers concerns both the application of biopolymers and the use of valorized plant derivatives as fillers and modifiers of petrochemical polymers. Herein, the possibility of using unprocessed raw parts of two commonly used in the food industry leaves, i.e., lemon (LL) and stevia (ST), as active and functional fillers for high-density polyethylene...
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Data-Driven Modeling of Mechanical Properties of Fiber-Reinforced Concrete: A Critical Review
PublicationFiber-reinforced concrete (FRC) is extensively used in diverse structural engineering applications, and its mechanical properties are crucial for designing and evaluating its performance. The compressive, flexural, splitting tensile, and shear strengths of FRCs are among the most important attributes, which have been discussed more extensively than other properties. The accurate prediction of these properties, which are required...
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FEM and experimental investigations of concrete temperature field in the massive stemwall of the bridge abutment
PublicationThe paper deals with the prediction of early-age concrete temperature of cast-in-place stemwall of the bridge abutment. The considered object is an arch bridge located in Gda´nsk. In the case of massive structures, it is particularly important to not exceed the temperature difference between the core and the concrete surface. Too high temperature gradient generates an increase in thermal stresses, what could be the reason of exceeding...
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Biomedical engineering of polysaccharide-based tissue adhesives: Recent advances and future direction
PublicationTissue adhesives have been widely used for preventing wound leaks, sever bleeding, as well as for enhancing drug delivery and biosensing. However, only a few among suggested platforms cover the circumstances required for high-adhesion strength and biocompatibility, without toxicity. Antibacterial properties, controllable degradation, encapsulation capacity, detectability by image-guided procedures and affordable price are also...
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Linkages between services and manufacturing as a new channel for GVC growth: evidence from CEE countries
PublicationThe aim of this paper is to use a panel Granger causality test to verify the hypothesis of the existence of a causal relationship between forward linkages from domestic services to manufacturing and a country’s participation and position in GVCs in selected central and eastern European economies – the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland and Slovakia – for the period 2000-2014. Our results show that the Baltic...
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Insights into Compatibilization of Poly(ε-caprolactone)-based Biocomposites with Diisocyanates as Modifiers of Cellulose Fillers
PublicationThis study aimed to analyze the impact of cellulose fillers’ modification with diisocyanates on the performance of composites based on the poly(ε-caprolactone) (PCL) matrix. Four most commonly used diisocyantes (isophorone, hexamethylene, toluene, and methylene diphenyl) were applied as modifiers of cellulose fillers (5 and 15 wt% per mass of filler). Modified fillers were introduced in the amount of 30 wt% into the PCL matrix....
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MANDARIN PEEL AS AN AUSPICIOUS FUNCTIONAL FILLER FOR POLYMER COMPOSITES
PublicationThis work describes the application of mandarin peel (MP) as a waste filler for high-density polyethylene (HDPE) composites. The main goal was to investigate the impact of the filler's essential oils, which include multiple terpenes and terpenoids, on the processing, physicochemical, mechanical, and thermal properties of the composites as a function of different filler content (1 – 10 wt%), as well as its effect on the color and...
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Application of advanced spectroscopic methods in the assessment of the leachability degree of hazardous elements from the matrix of cellular concretea
PublicationDue to its structure, autoclaved cellular concrete exhibits good insulating properties with relatively high compressive strength values. It is increasingly used in construction because of its economic attractiveness. Autoclaved cellular concrete is mainly used in interior structure layers, and therefore its potential exposure to heavy metal leaching from the matrix may be related to the presence of a high pH medium from other materials...
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Numerical analysis on axial capacity of steel built-up battened columns
PublicationThis paper deals with the numerical analysis aimed at study the bearing capacity of pinended steel built-up columns under axial compression. Finite element (FE) models were performed for the columns presented in the literature. The main problem discussed in the article is the shape and magnitude of geometric imperfections introduced into the numerical FE model, necessary to obtain the load capacity consistent with the experimental...
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Impact of reclaimed asphalt pavement (RAP) on low-temperature properties of asphalt concrete
PublicationHot mix recycling is a practice which enables reusing materials from old asphalt pavements. Current Polish regulations allow usage of RAP only for binder and base courses, and its amount is limited. Asphalt mixtures with RAP material have to fulfil requirements stated for typical asphalt mixtures. The research presents low-temperature properties of twelve different asphalt concretes with RAP material, determined using three-point...
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Areas of Updraft Air Motion in an Idealised Weather Research and Forecasting Model Simulation of Atmospheric Boundary Layer Response to Different Floe Size Distributions
PublicationPresented dataset is part of a numerical modelling study focusing on the analysis of the influence of sea ice floe size distribution (FSD) on the horizontal and vertical structure of convection in the atmosphere. The total area and spatial arrangement of the up-drafts indicates that the FSD affects the total moisture content and the values of area averaged turbulent fluxes in the model domain. In fact, while convective updrafts...
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An approach to evaluation of arguments in trust cases
PublicationTrustworthiness of IT systems can be justified using the concept of a trust case. A trust case is an argument structure which encompasses justification and evidence supporting claimed properties of a system. It represents explicitly an expert's way of assessing that a certain object has certain properties. Trust cases can be developed collaboratively on the basis of evidence and justification of varying quality. They can be complex...
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STABILITY ANALYSIS OF A TRUSS WITH SLOPING ELASTIC BRACES
PublicationSteel trusses have a much greater strength and stiffness in their plane than out of their plane, and therefore should be braced against lateral deflection and twisting. Such elements like purlins apart from bearing vertical load are part of bracing that stabilize roof trusses against distortional buckling. The stability of trusses with elastic bracing was investigated in an experimental research. Braces situated at some angle measured...
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The Influence of Modelling Material Zones on Strains and Stresses at Weld Toe Notch
PublicationThe latest development in the field of welding technology enabled prefabrication of thin-walled sandwich structures in an industrial scale. Sandwich structures fabricated of steel, or aluminium alloy plates and stiffeners are welded with the use of hi-power CO2 lasers. Strength analysis of such structures with the use of finite element method needs proper material modelling.In this paper the material model of steel sandwich panel...
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Debonding Detection in Reinforced Concrete Beams with the Use of Guided Wave Propagation
PublicationOne of the most frequent damage of the reinforced concrete structures is debonding between steel bar and concrete cover. In the case of debonding occurrence not only the strength of the structure decreases, but also it is more vulnerable to corrosion damages. For this reason fast and effective methods of debonding detection in an early stage of its development need a significant boost. The paper presents analytical and experimental...
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RSS-based DoA Estimation Using ESPAR Antennas and Interpolated Radiation Patterns
PublicationIn this letter, it is shown how an algorithm, which employs received signal strength (RSS) values in order to estimate direction-of-arrival (DoA) of impinging signals in wireless sensor network (WSN) nodes equipped with electronically steerable parasitic array radiator (ESPAR) antennas, can easily be improved by applying an interpolation algorithm to radiation patterns recorded in the calibration phase of the DoA estimation process....
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Simple 2-D Direction-of-Arrival Estimation Using an ESPAR Antenna
PublicationIn this letter, it has been shown how an electronically steerable parasitic array radiator (ESPAR) antenna can be used for 2-D direction-of-arrival (DoA) estimation employing received signal strength (RSS) values only. The proposed approach relies on changes in RSS values recorded at the antenna output port observed for different vertical and horizontal directions, while antenna’s main beam sweeps 360° area around the ESPAR antenna. Based...
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Degradation of polycaprolactone modified with TPS or CaCO3 in biotic/abiotic seawater
PublicationThis paper is an investigation of the polymer degradation process in two types of seawater (with and without microorganisms) sourced from the Baltic Sea. The chosen polymeric materials were polycaprolactone modified with either thermoplastic starch (PCL/TPS>85%) or calcium carbonate (60% PCL/40% CaCO3) compared directly against unmodified polycaprolactone. All samples were incubated for 28 weeks in seawater with and without microorganisms...
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Superconductivity in the intermetallic compound Zr5Al4
PublicationPolycrystalline Zr5Al4 was synthesized using the arc-melting method. Powder X-ray diffraction confirms the previously reported crystal structure of the Ti5Ga4-type P63/mcm with lattice parameters: a = 8.4312(6) A , and c = 5.7752(8) A . Electrical resistivity and low-temperature magnetic susceptibility measurements indicate that Zr5Al4 exhibits superconducting behavior below 2 K. The normalized heat capacity jump at Tc= 1.82 K...
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Morphology and mechanical properties of polyamide/clay nanocomposites toughened with NBR/NBR-g-GMA: A comparative study
PublicationThis work highlights the importance of nanoclay dispersion state in the nanocomposites containing polyamide 6 (PA6), nanoclay and elastomers as well as clay localization at the interface of thermoplastic/elastomer. Morphology and mechanical properties of a series of nanocomposites containing acrylonitrile butadiene rubber (NBR), glycidyl methacrylate-grafted NBR (NBR-g-GMA), and combined NBR/NBR-g-GMA were compared and discussed...
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ReFlexeNN - the Wearable EMG Interface with Neural Network Based Gesture Classification
PublicationThe electromyographic activity of muscles was measured using a wireless biofeedback device. The aim of the study was to examine the possibility of creating an automatic muscle tension classifier. Several measurement series were conducted and the participant performed simple physical exercises - forcing the muscle to increase its activity accordingly to the selected scale. A small wireless device was attached to the electrodes placed...
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RSS-Based DoA Estimation Using ESPAR Antenna Radiation Patterns Spline Interpolation
PublicationIn this paper, it is shown how power pattern crosscorrelation (PPCC) algorithm, which relies on received signal strength (RSS) values recorded at electronically steerable parasitic array radiator (ESPAR) antenna output port, used for direction-of-arrival (DoA) estimation, can easily be improved by applying spline interpolation to radiation patterns recorded in the calibration phase of the DoA estimation process. The proposed method...
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A novel calibration method for RSS-based DoA estimation using ESPAR antennas
PublicationIn this paper, we introduce a new calibration method that can successfully be used in direction of arrival (DoA) estimation using electronically steerable parasitic array radiator (ESPAR) antennas and employing power-pattern cross-correlation (PPCC) algorithm, which relies on received signal strength (RSS) values recorded at the antenna output port. Instead of the commonly used two-step approach, during which ESPAR antenna calibration...
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Numerical and experimental study on effect of boundary conditions during testing of stiffened plates subjected to compressive loads
PublicationThis study analyses the effect of boundary conditions during testing on the structural behaviour stiffened plates with different thicknesses subjected to compressive loads. The goal of the compressive tests is to analyse the ultimate strength of a stiffened plate. During the test, relevant physical quantities are measured and investigated. The supporting structure's behaviour is investigated by analysing the force-displacements...
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Weldability of Underwater Wet-Welded HSLA Steel: Effects of Electrode Hydrophobic Coatings
PublicationThe paper presents the effects of waterproof coatings use to cover electrodes on the weldability of high-strength, low-alloy (HSLA) steel in water. With the aim of improving the weldability of S460N HSLA steel in water, modifications of welding filler material were chosen. The surfaces of electrodes were covered by different hydrophobic substances. The aim of the controlled thermal severity (CTS) test was to check the influence...
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By-Products from Food Industry as a Promising Alternative for the Conventional Fillers for Wood–Polymer Composites
PublicationThe present paper describes the application of two types of food-industry by-products, brewers’ spent grain (BSG), and coffee silverskin (ŁK) as promising alternatives for the conventional beech wood flour (WF) for wood–polymer composites. The main goal was to investigate the impact of partial and complete WF substitution by BSG and ŁK on the processing, structure, physicochemical, mechanical, and thermal properties of resulting...
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Dispersive Micro‐Solid Phase Extraction of Selected Metals in Water and Food Samples Followed by ICP‐OES Analysis: Method Development, Analysis of Real Samples and Greenness Evaluation
PublicationMultiwalled carbon nanotubes (MWCNTs) are well-known adsorbents because of their high surface area, layered and hollow architecture, hydrophobicity, and multiple and easily accessible adsorption sites. In this study, MWCNTs were used for dispersive micro-solid-phase extraction of various metal chelates in environmental and food samples. Different parameters such as concentration of the chelating reagent, the sorbent dosage, the...
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Influence of friction stir welding technological parameters on the properties of the joints of selected aluminum alloys
PublicationThe purpose of this dissertation was to determine the effect of friction stir welding technological parameters on the properties of selected aluminum alloy joints, with consideration of the residual stresses and dislocation density in the joints. The goal of the present work was also to produce defect-free joints with high mechanical and electrochemical properties. In the dissertation, similar welds of AA6082 alloy and dissimilar...
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Analysis of the Possibilities of Applying 3D Print Methods for the Needs of Ship-Building Industry
PublicationArticle presents the analysis of applying additive and hybrid manufacturing methods and its impact on dynamic stiffness of prepared samples. Dynamic analysis of the handle bracket specimens consisted in plotting the resonance curves and using these curves to estimate the dynamic stiffness of elements produced with additive manufacturing technology. Authors focused especially on 3D print in Fused Deposiotion Modeling/Fused Filament...
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Direct reduction of pellets through hydrogen: Experimental and model behaviour
PublicationThis paper presents the hydrogen reduction behaviour of industrial pellets designed for the efficient hydrogen based direct reduction. The pellets were provided with very low non ferrous oxides percentage (0.52 of basicity index) and with the absence on TiO2 oxides. The pellets measured diameters in the range 1.14–1.72 cm and were characterized in terms of porosity, pores size, tortuosity and compression strength. The pellets were...
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Impact of laser beam welding on mechanical behaviour of 2.25Cr–1Mo (P22) steel
PublicationThe use of welding processes in the manufacturing and repair of structures intended for the energy industry plays a key role in the guarantee of a continuous supply of fossil fuels, which is the basic condition for ensuring energy security. A square butt joint of 10 mm thick plate of 2.25Cr–1Mo (P22) steel was fabricated by autogenous laser beam welding process and then post-weld heat treatment (PWHT) for two sets of process parameters...
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An investigation on the role of GMA grafting degree on the efficiency of PET/PP-g-GMA reactive blending: morphology and mechanical properties
PublicationGlycidyl methacrylate (GMA) has been grafted on polypropylene (PP) with the aid of styrene (St) comonomer, by changing dicumyl peroxide initiator content, GMA level, and St concentration. The performance of the resulting PP-g-GMA reactive material towards static and dynamic mechanical properties of poly (ethylene terephthalate) (PET) was monitored in terms of grafting reaction variables and compatibilizer content. Fourier transform...
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To what extent can hyperelastic models make sense the effect of clay surface treatment on the mechanical properties of elastomeric nanocomposites?
PublicationThe poor knowledge about nonlinear mechanical behavior of elastomer nanocomposites arises from the incomplete information on the interface. Application of hyperelastic models provides more insights into the nature and the situation of interaction between the elastomeric matrix and nanofillers. The current work seeks to address the effect of interphase strength on tensile properties of the elastomer nanocomposites under large deformations....
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High-density Polyethylene - Expanded Perlite Composites: Structural Oriented Analysis of Mechanical and Thermomechanical Properties
PublicationAs part of this work, research was carried out on the effect of the addition of expanded perlite (PR) on the mechanical and thermomechanical properties of high-density polyethylene (PE) composites. Composites containing from 1 to 10 wt% of the inorganic filler were produced. Polyethylene-based composites manufactured by twin-screw extrusion and formed in the compression molding process were subjected to mechanical, thermomechanical,...
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APPLICATION POSSIBILITIES OF THE S960 STEEL IN UNDERWATER WELDED STRUCTURES
PublicationIn this paper, the application possibilities of the ultra-high strength (UHSS). Domex 960 steel in the underwater welded structures are analyzed. In the research, the investigated material has been tested in bead-on-plate wet welding conditions with the usage of different heat input values, namely 0.63 kJ/mm, 0.72 kJ/mm and 0.93 kJ/mm. Specimens were performed by the manual metal arc (MMA) welding method with the usage of rutile...
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Electrodeposited Biocoatings, Their Properties and Fabrication Technologies: A Review
PublicationCoatings deposited under an electric field are applied for the surface modification of biomaterials. This review is aimed to characterize the state-of-art in this area with an emphasis on the advantages and disadvantages of used methods, process determinants, and properties of coatings. Over 170 articles, published mainly during the last ten years, were chosen, and reviewed as the most representative. The most recent developments...
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Manufacturing of Lightweight Aggregates as an Auspicious Method of Sewage Sludge Utilization
Publication: Sewage sludge is a high-volume and low-cost waste commonly generated worldwide, so its utilization is a vital issue. The application of this waste in the manufacturing of lightweight aggregates was investigated. The process was performed using intensive mixers with volumes of 5 and 30 L, as well as the industrial 500 L mixer. Then, granulates were sintered in a tube furnace. The influence of composition and mixer size on the...
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Experimental Studies of Concrete-Filled Composite Tubes under Axial Short- and Long-Term Loads
PublicationThe paper presents experimental studies on axially compressed columns made of concrete-filled glass fiber reinforced polymer (GFRP) tubes. The infill concrete was C30/37 according to Eurocode 2. The investigated composite pipes were characterized by different angles of fiber winding in relation to the longitudinal axis of the element: 20, 55 and 85 degrees. Columns of two lengths, 0.4 m and 2.0 m, were studied. The internal diameter...
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Evaluation of Mechanical Properties of Two-Stage Concrete and Conventional Concrete Using Nondestructive Tests
PublicationDifferent types of concrete mixtures are used as building materials. The manufacturing process of two-stage concrete (TSC) differs from that of conventional concrete. This study investigated conventional mechanical properties derive empirical relations for estimation of the mechanical parameters of TSC and conventional concrete mixtures. TSC was used to prepare 216 specimens and conventional concrete was used to prepare 108 specimens...
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Dissimilar underwater wet welding of HSLA steels
PublicationThe high-strength low-alloy S460ML and S460N steels were chosen for underwater wet welding of dissimilar T-joints using covered electrodes. For improving the quality of joints, the temper bead welding (TBW) method was used. The application of TBW in pad welding conditions has been investigated earlier but the possibility of usage of this technique in welded joints was not analyzed. The main aim of the study was to check the influence...
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The Impact of Thermal Stresses on Volume Resistivity: Performance Comparison between TR-XLPE and XLPE Cables
PublicationMost failures in electric power cables are attributed to the development of water trees inside the insulating materials. Thus, the development and utilization of Tree Retardant Cross-Linked Polyethylene (TR-XLPE) based cables have recently been given great attention to overcome the treeing issues. TR-XLPE cables use low-density polyethylene compounds suppressing the formation of water trees while retaining excellent electrical,...
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Określenie położenia za pomocą sieci bezprzewodowej w standardzie ZigBee
PublicationMimo wprowadzenia systemu nawigacji GPS, nadal istnieje zapotrzebowanie na inne, tańsze systemy lokalizacji położenia, w szczególności pracujące w pomieszczeniach, gdzie często nie dochodzi sygnał z satelity. Taki system można zrealizować za pomocą bezprzewodowej sieci czujników w standardzie ZigBee za pomocą kilku różnych metod. W pracy przedstawiono metodę RSSI (ang.: Received Signal Strength Indicator) oceny odległości za pomocą...
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Computer vision techniques applied for reconstruction of seafloor 3D images from side scan and synthetic aperture sonars data
PublicationThe Side Scan Sonar and Synthetic Aperture Sonar are well known echo signal processing technologies that produce 2D images of the seafloor. Both systems combines a number of acoustic pings to form a high resolution image of seafloor. It was shown in numerous papers that 2D images acquired by such systems can be transformed into 3D models of seafloor surface by algorithmic approach using intensity information, contained in a grayscaled...
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COMPOSITE MATERIAL SELECTION FOR A PATIENT TRANSFER ASSIST DEVICE
PublicationLaminates - layered composites containing at least two elements (matrix and reinforcement) widely used in industry have also found their usage in medicine. Their main feature is the ability to modify the material in order to obtain the required properties. Depending on the needs, we can modify reinforcement, type of resin or the method of bonding substrates. Commonly used fibers are: carbon fiber, glass and aramid fibers; resins...
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Propagation of initially sawtooth periodic and impulsive signals in a quasi-isentropic magnetic gas
PublicationThe characteristics of propagation of sawtooth periodic and impulsive signals at a transducer are analytically studied in this work. A plasma under consideration is motionless and uniform at equilibrium, and its perturbations are described by a system of ideal magnetohydrodynamic equations. Some generic heating/cooling function, which in turn depends on equilibrium thermodynamic parameters, may destroy adiabaticity of a flow and...
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Direction-of-Arrival Estimation Using an ESPAR Antenna with Simplified Beam Steering
PublicationIn this paper, it has been shown, how electronically steerable parasitic array radiator (ESPAR) antenna, in which beam steering is done in a simple way, can be used for directionof- arrival (DoA) estimation of an unknown signal impinging the antenna. The concept is based on an ESPAR antenna having twelve parasitic elements, in which beam switching is realized by RF switches providing required loads to its parasitic elements. Numerical...