Wyniki wyszukiwania dla: composite materials
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The Way One Defines Specification Matters: On the Performance Criteria for Efficient Antenna Optimization in Aggregated Bi-Objective Setups
PublikacjaDesign of antenna structures for real-world applications is a challenging task that often involves addressing multiple design requirements at a time. Popular solution approaches to this class of problems include utilization of composite objectives. Although configuration of such functions has a significant effect on the cost and performance of the optimization, their specific structure is normally determined based on engineering...
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Customizing nano-chitosan for sustainable drug delivery
PublikacjaChitosan is a natural polymer with acceptable biocompatibility, biodegradability, and mechanical stability; hence, it has been widely appraised for drug and gene delivery applications. However, there has been no comprehensive assessment to tailor-make chitosan cross-linkers of various types and functionalities as well as complex chitosan-based semi- and full-interpenetrating networks for drug delivery systems (DDSs). Herein, various...
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Visible-light-driven lanthanide-organic-frameworks modified TiO2 photocatalysts utilizing up-conversion effect
PublikacjaHighly efficient and quite stable composite with core-shell-like architecture reported herein, responds to the challenge of sunlight-driven photocatalysts. The Ln(ndc)/TiO2 photocatalytic system comprises active lanthanide-carboxylate coordination networks (Nd, Er, Ho, and Tm as metal ions, and 2,6-naphthalene dicar-boxylic acid as the organic linker) and inert titanium dioxide and allow to convert incompatible visible radiation...
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Super tough interpenetrating polymeric network of styrene butadiene rubber‐poly (methyl methacrylate) incorporated with general purpose carbon black ( N660 )
PublikacjaA classic set of polymeric interpenetrating polymeric network (IPN) microcomposites has been fabricated using an elastomer—styrene butadiene rubber [SBR], a thermoplastic poly(methyl methacrylate)-PMMA and with carbon black (CB)-N660 as a filler and reinforcing agent. This synthesized IPN composite can be promisingly employed as a toughened plastic and vibrational damper in a wide service range with excellent thermal stability,...
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High catalytic performance of laccase wired to naphthylated multiwall carbon nanotubes
PublikacjaThe direct electrical connection of laccase on the electrode surface is a key feature in the design of efficient and stable biocathodes. However, laccases can perform a direct electron transfer only when they are in the preferable orientation toward the electrode. Here we report the investigation of the orientation of Laccase from Amano on multi-walled carbon nanotube surface modified with naphthalene group. Naphthylated multi...
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Numerical analyses of novel prefabricated structural wall panels in residential buildings based on laboratory tests in scale 1:1
PublikacjaThe paper presents experimental and numerical investigations on novel prefabricated composite building wall panels for residential building constructions. The wall panels were composed of reinforced concrete ribbed elements with the core from the EPS foam as the thermal insulation. The wall panels in the full-scale 1:1 were subjected to vertical loads. In the first step, the experiments were analysed with simple usual static methods....
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Cyclic Behavior of Masonry Shear Walls Retrofitted with Engineered Cementitious Composite and Pseudoelastic Shape Memory Alloy
PublikacjaThe behavior of masonry shear walls reinforced with pseudoelastic Ni–Ti shape memory alloy (SMA) strips and engineered cementitious composite (ECC) sheets is the main focus of this paper. The walls were subjected to quasi-static cyclic in-plane loads and evaluated by using Abaqus. Eight cases of strengthening of masonry walls were investigated. Three masonry walls were strengthened with different thicknesses of ECC sheets using...
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Tailoring optical constants of few-layer black phosphorus coatings: Spectroscopic ellipsometry approach supported by ab-initio simulation
Publikacja2D black phosphorus (BP) has attracted extensive attention as an anisotropic platform for novel optoelectronic and polarizing optics applications. Insight into the factors that tune the optical and polarizing properties of 2D BP reveals their essential influence on BP-based photonic and optoelectronic devices. In this work, studies of the optical constants of few-layer black phosphorus coatings are studied and discussed, with particular...
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Application of chemometric modeling for ionic liquid-based ultrasonic-assisted dispersive liquid-liquid microextraction: Analysis of fosetyl-aluminum in fruit and vegetable samples
PublikacjaThis manuscript presents a new method for selective extraction and determination of fosetyl-aluminum in fruits and vegetable samples based on ultrasonic-assisted dispersive liquid-liquid microextraction method using ionic liquids (IL-UA-DLLME). A UV-Visible spectrophotometer was used for detection and quantification. Plants used for sample collection were grown under controlled conditions in a greenhouse. Central composite design...
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Experimental and Numerical Investigations of the Effect of Curing Conditions on the Temperature Rise of Concrete
PublikacjaThis paper presents experimental and numerical studies investigating the impact of three curing conditions on temperature evolution in concrete cubes. The tests were performed on samples of the same volume (3.375 dm3) under different curing conditions: room temperature, insulation boxes, and adiabatic calorimeter. Various cements (Portland cement, Portland composite cement, and blast furnace slag cement) and aggregates (gravel...
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Load capacity and serviceability conditions for footbridges made of fibre-reinforced polymer laminates = Warunki nośności i użytkowalności w odniesieniu do kładek z laminatów polimerowych
PublikacjaThe contribution is focused on derivation of the Ultimate Limit State (ULS) and Serviceability Limit State (SLS) design criteria for footbridges built of fibre-reinforced polymer matrix (FRP) laminates. The ULS design criterion is based on the design guidelines for above-ground, pressure, FRP composite tanks and the Tsai-Wu failure criterion, which is used to predict the onset of FRP laminates damage. The SLS criterion is based...
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Estimation of Failure Initiation in Laminated Composites by means of Nonlinear Six-Field Shell Theory and FEM
PublikacjaThe monography deals with the problem of failure initiation in thin laminated composites. Known techniques of laminate structures modelling are briefly characterised. Eventually, shell based approach is chosen for the purpose of the description of the composite structures behaviour, as it predicts their deformation and states of stress effectively in a global sense. The nonlinear six parameter shell theory (6p theory) with asymmetric...
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Analysis of Modal Parameters Using a Statistical Approach for Condition Monitoring of the Wind Turbine Blade
PublikacjaThe primary objective of the presented paper is the numerical and experimental investigation related to developing a useful diagnostic method, which can be used for determining the site and size of damage in laminated shells of wind turbine blades. The described detection technique is based on the analysis of low frequencies bending vibrations mode shapes of rotor blades. The authors used the commonly applied statistics methods...
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Load-carrying capacity of axially loaded concrete-filled steel tubular columns made of thin tubes
PublikacjaAn experimental investigation was conducted on 30 CFST columns. An influence of the following factors on load-carrying capacity of the investigated columns was analyzed: the column slenderness (l1 = 42, l2 = 27 and l3 = 15), the tube thickness (the reinforcement ratio was equal to 4% or 6%), the way of applying the load to CFST columns (through the concrete core or through the entire cross-section), the bond strength between a...
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Flame retardant epoxy/halloysite nanotubes nanocomposite coatings: Exploring low-concentration threshold for flammability compared to expandable graphite as superior fire retardant
PublikacjaEpoxy nanocomposites containing halloysite nanotubes (HNTs) were developed and their low-concentration thresholds for thermal stability and flame retardancy were compared with that of epoxy system containing expandable graphite (EG), as a reference with superior flame retardancy. The effects of HNTs and EG on the peak of Heat Release Rate (pHRR), Total Heat Release (THR), and Time-To-Ignition (TTI) of the prepared samples were...
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Structural Changes and Their Implications in Foamed Flexible Polyurethane Composites Filled with Rapeseed Oil-Treated Ground Tire Rubber
PublikacjaThe utilization of post-consumer car tires is an essential issue from an ecological andeconomic point of view. One of the simplest and the least harmful methods is their material recyclingresulting in ground tire rubber (GTR), which can be further applied as fillers for polymer-basedcomposites. Nevertheless, insufficient interfacial interactions implicate the necessity of GTR modi-fication before introduction into polymer matrices....
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Effects of electrophoretic deposition times and nanotubular oxide surfaces on properties of the nanohydroxyapatite/nanocopper coating on the Ti13Zr13Nb alloy
PublikacjaLoad-bearing implants are developed with a particular emphasis placed on an application of ceramic hydroxyapatite coatings in order, to enhance the bioactivity of titanium implants and to shorten the healing time. Therefore, thin, fully crystalline coatings that are, highly adhesive, hydrophilic and demonstrating antibacterial properties are ly looked for. The aim of this research was to develop and characterize the properties...
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Deep eutectic solvents based highly efficient extractive desulfurization of fuels – Eco-friendly approach
PublikacjaThe developed process is based on alternative, green and cheap solvents for efficient desulfurization of fuels. Several deep eutectic solvents (DESs) were successfully synthesized and studied as extraction solvents for desulfurization of model fuel containing thiophene (T), benzothiophene (BT) and dibenzothiophene (DBT). The most important extraction parameters (i.e. kind of DES, DES: fuel volume ratio, hydrogen bond acceptor:...
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Dominik Jasiński dr
OsobyDr Dominik Jasiński jest absolwentem międzynarodowych studiów doktoranckich ukończonych w Wielkiej Brytanii na wydziale Warwick Manufacturing Group wchodzącego w skład University of Warwick. Stopień doktora nauk technicznych otrzymał w roku 2019 w zakresie zrównoważonych materiałów (w tym odnawialnych) oraz zrównoważonej produkcji. Projekt realizowany przez niego w ramach studiów doktoranckich, sponsorowany przez EPSRC oraz firmę...
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Combination of homogeneous liquid–liquid extraction and vortex assisted dispersive liquid–liquid microextraction for the extraction and analysis of ochratoxin A in dried fruit samples: Central composite design optimization
PublikacjaThis paper presents a new analytical procedure based on combination of homogeneous liquid–liquid extraction (HLLE) and vortex-assisted dispersive liquid–liquid microextraction (VA-DLLME) for the accurate and reliable determination of ochratoxin A (OTA) in dried fruit samples. To enable selective extraction of the OTA, six hydrophobic deep eutectic solvents (hDESs) were prepared and tested as extraction solvents. Optimization of...
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Development of an orbital shaker-assisted fatty acid-based switchable solvent microextraction procedure for rapid and green extraction of amoxicillin from complex matrices: Central composite design
PublikacjaIn this study, a cheap, fast and simple orbital shaker-assisted fatty acid-based switchable solvent microextraction (OS-FASS-ME) procedure was developed for the extraction of amoxicillin (AMOX) in dairy products, pharmaceutical samples and wastewater prior to its spectrophotometric analysis. Fatty acid-based switchable solvents were investigated for extracting AMOX. The key factors of the OS-FASS-ME procedure were optimized using...
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Polyurethane-wood composites (PU-WC) as a method of wood waste management
PublikacjaIn recent years, due to the progressive environmental degradation and increase of environmental awareness, the sustainability of production systems in wood processing, the wood industry, and wood waste management is a crucial issue for European industry and society. Consequently, the problem of generating wood-like waste and the associated risks has become an increasingly noticeable challenge for science. Although various methods...
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The influence of core material on strength properties of hybrid sandwich panels
PublikacjaAlong with high prices of fuels and more restrictive safety and environmental regulations (including environment protection) increased interest in sandwich structures is being observed. One of the solution having growing application potential is steel sandwich panel. The construction consist of very thin steel plates (about 2mm) and stiffeners between them. The main advantage of using such solution is very high strength to weight...
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Bio polyetherurethane composites with high content of natural ingredients: hydroxylated soybean oil based polyol, bio glycol and microcrystalline cellulose
PublikacjaIn our study, we focused on obtaining bio-polyurethane composites using bio-components such as bio glycol, modified natural oil-based polyol, and microcrystalline cellulose (MCC). The pre-polymer method was used to prepare the bio polyurethane matrix. Prepolymer was synthesized using 4,4’-diphenylmethane diisocyanate (MDI) and a polyol mixture containing 50 wt.% of commercial polyether and 50 wt.% of hydroxylated soybean oil (H3)....
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Surface sliding in human abdominal wall numerical models: Comparison of single-surface and multi-surface composites
PublikacjaDetermining mechanical properties of abdominal soft tissues requires a coupled experimental-numerical study, but first an appropriate numerical model needs to be built. Precise modeling of human abdominal wall mechanics is difficult because of its complicated multi-layer composition and large variation between specimens. There are several approaches concerning simplification of numerical models, but it is unclear how far one could...
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Magnetic semiconductor photocatalysts for the degradation of recalcitrant chemicals from flow back water
PublikacjaIn the present study treatability of persistent organic compounds from the flow back water after hydrauling fracturing was investigated. The combination of TiO2 photocatalyst and magnetic oxide nanoparticles enhance the separation and recoverable property of nanosized TiO2 photocatalyst. Fe3O4/ TiO2 and Fe3O4@SiO2/TiO2 nanocomposites were prepared by heteroagglomeration. The photocatalysts’ characteristics by X-ray diffractometry...
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Innovative investment funds and stability of financial systems: Nonparametric study of exchange-traded funds in Europe
PublikacjaThe main aim of the paper is investigation of the potential contribution of exchange-trade funds (ETFs) to the instability of the European financial systems. The paper begins with presentation of the key theoretical concepts with regard to ETFs and financial stability. We discuss the key attributes of ETFs as the innovative category of investment funds, their hypothesized impact on the financial stability as well as briefly describe...
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A study on diagnosing both isotropic and orthotropic, intentionally damaged laminates
PublikacjaBeing the most detrimental mode in laminated structures, delamination initially degrades local structural strength, and lastly causes global structural failure, thus necessitating delamination identification at its incipient stages. For identification purposes, a comprehensive numerical and experimental study on delamination within both the laminated isotropic acrylic-glass and orthotropic epoxyglass plates is presented. As the...
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Ultrasound-assisted wet-impregnation of Ag–Co nanoparticles on cellulose nanofibers: Enhanced catalytic hydrogenation of 4-nitrophenol
PublikacjaIn this study, a novel nanocomposite of bimetallic Ag–Co nanoparticles supported on cellulose nanofibers (CNFs) was synthesised using the ultrasound-assisted wet-impregnation method for catalytic applications. CNFs were prepared from cellulose acetate using the electrospinning technique. Fourier transform infrared spectroscopy (FTIR) analysis confirmed the successful synthesis of CNFs. Further, scanning electron microscopy (SEM)...
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Combination of air-dispersion cathode with sacrificial iron anode generating Fe2+Fe3+2O4 nanostructures to degrade paracetamol under ultrasonic irradiation
PublikacjaIn the present study, ultrasound (US) was coupled with an electrochemical process (ECP) consisting of a novel cathode of carbon cloth (CC)-carbon black (CB) as the nano-composite air-dispersion cathode (NADC) for the degradation of paracetamol (APAP) in an aquatic medium. The NADC favored in situ production of H2O2 by the cathodic reduction. The implementation of iron sacrificial anode instead of dimensionally stable anodes resulted...
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THE APPLICATION OF PHENOMENOLOGICAL METHODOLOGY FOR DESIGNING PILE FOUNDATION IN PORT STRUCTURES
PublikacjaIt is of utmost importance in the design process that a suitable, safe and concurrently economic solution be chosen. Issues connected with foundations require adopting a special approach. Soil is a composite medium, and it is essential to describe as precisely as possible the interaction taking place between the subgrade and the structure. There are many design methods of pile foundation that are based on in-situ test of soils....
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Selection of circuit geometry for miniaturized microwave components based on concurrent optimization of performance and layout area
PublikacjaThe paper presents a framework for automated EM-driven circuit geometry selection of miniaturized microwave components. Selection of a particular layout is based directly on miniaturization rates achieved for a set of candidate circuit geometries. Size reduction of the considered structures is obtained by replacing their main building blocks (i.e., conventional transmission lines) with slow-wave composite cells and meander lines....
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Extractive detoxification of hydrolysates with simultaneous formation of deep eutectic solvents
PublikacjaThe hydrolysis of lignocellulosic biomass results in the production of so-called fermentation inhibitors, which reduce the efficiency of biohydrogen production. To increase the efficiency of hydrogen production, inhibitors should be removed from aqueous hydrolysate solutions before the fermentation process. This paper presents a new approach to the detoxification of hydrolysates with the simultaneous formation of in-situ deep eutectic...
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Investigation of use of hydrophilic/hydrophobic NADESs for selective extraction of As(III) and Sb(III) ions in vegetable samples: Air assisted liquid phase microextraction and chemometric optimization
PublikacjaIn this paper, a green, cost-effective sample preparation method based on air assisted liquid phase microextraction (AA-LPME) was developed for the simultaneous extraction of As(III) and Sb(III) ions from vegetable samples using hydrophilic/hydrophobic natural deep eutectic solvents (NADESs). Central composite design was used for the optimization of extraction factors including NADES volume, extraction cycle, pH, and curcumin concentration....
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Effects of thermal history on the performance of low-temperature solid oxide fuel cells with Sm0.2Ce0.8O2-δ electrolyte and LiNi0.81Co0.15Al0.04O2 electrodes
PublikacjaIn this study, low-temperature solid oxide fuel cells with an ∼560 μm thick Sm0.2Ce0.8O2−δ (SDC) electrolyte and ∼890 μm thick LiNi0.81Co0.15Al0.04O2−δ (NCAL) electrodes are constructed and characterized under three experimental conditions. The cell with an NCAL cathode pre-reduced under an H2 atmosphere at 550 °C presents the best electrochemical performance. This is ascribed to facts that the reduction reaction generating Ni–Co...
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Silver nanoparticles incorporated with superior silica nanoparticles-based rice straw to maximize biogas production from anaerobic digestion of landfill leachate
PublikacjaTreating hazardous landfill leachate poses significant environmental challenges due to its complex nature. In this study, we propose a novel approach for enhancing the anaerobic digestion of landfill leachate using silver nanoparticles (Ag NPs) conjugated with eco-friendly green silica nanoparticles (Si NPs). The synthesized Si NPs and Ag@Si NPs were characterized using various analytical techniques, including transmission electron...
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Multifunctional catalyst-assisted sustainable reformation of lignocellulosic biomass into environmentally friendly biofuel and value-added chemicals
PublikacjaRapid urbanization is increasing the world's energy demand, making it necessary to develop alternative energy sources. These growing energy needs can be met by the efficient energy conversion of biomass, which can be done by various means. The use of effective catalysts to transform different types of biomasses will be a paradigm change on the road to the worldwide goal of economic sustainability and environmental protection. The...
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Modeling and optimization of chemical-treated torrefaction of wheat straw to improve energy density by response surface methodology
PublikacjaToday, torrefaction is important technique for extending the potential of biomass for improvement of energy density. The independent variables investigated for torrefaction study were temperature, retention time, acid concentration, and particle size. The experiment was designed by central composite design (CCD) method using design expert (version 11). The three dependent variables were higher heating value (HHV), energy enhancement...
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Enhancing colloidal stability of nanodiamond via surface modification with dendritic molecules for optical sensing in physiological environments
PublikacjaPre-treatment of diamond surface in low-temperature plasma for oxygenation and in acids for carboxylation was hypothesized to promote the branching density of the hyperbranched glycidol polymer. This was expected to increase the homogeneity of the branching level and suppress interactions with proteins. As a result, composite nanodiamonds with reduced hydrodynamic diameters that are maintained in physiological environments were...
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Water-Lubricated Sintered Bronze Journal Bearings—Theoretical and Experimental Research
PublikacjaWater lubricated bearings are used from many years in shipbuilding, hydro power and other industries because of their advantages such as: extensive serviceable life, low coefficient of friction, longevity of shaft sleeve, good abrasion resistance, low maintenance required, unit simplicity, no danger of pollution and low price. Various types of water lubricated sliding bearings have been tested at the Technical University of Gdansk...
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Polymer based thick films - material quality and interface resistance evaluation
PublikacjaThe properties of polymer based thick film layers mede using different resistive pastes and dipping silvers have been studied. The composite of carbon and graphite (C/Gr) conducting particles suspended in different polymer vehicles were used for preparation resistive layers. Interface resistance Rc created between dipping silver (DiAg) contact layer and resistive layer was determined from the surface potential distribution measurements...
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Perovskite-type KTaO3–reduced graphene oxide hybrid with improved visible light photocatalytic activity
PublikacjaNovel rGO–KTaO3 composites with various graphene content were successfully synthesized using a facile solvothermal method which allowed both the reduction of graphene oxide and loading of KTaO3 nanocubes on the graphene sheets. The as-prepared photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX), Fourier...
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Preparation, morphology and properties of natural rubber composites filled with untreated short jute fibres
PublikacjaGreen composites were obtained by incorporation of short jute fibres in natural rubber matrix using a laboratory two-roll mill. The influence of untreated fibre content (1, 2.5, 5, 7.5 and 10 phr) on the mechanical properties, dynamic mechanical properties, swelling properties was examined. The behaviour of prepared green composites under cyclic compression was also investigated. Fibre dispersion in rubber matrix was studied by...
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A comparative study on selective properties of Kraft lignin–natural rubber composites containing different plasticizers
PublikacjaEffect of plasticizer type on the kraft lignin–nat- ural rubber composite microstructure and selected proper- ties was determined. The composites were prepared with addition of a commonly used naphthenic oil plasticizer to study the decomposition product of polyurethane (glyc- erolysate) and its characteristics. Kraft lignin powder was incorporated into the natural rubber matrix in amounts of 10 and 40 parts per 100 parts of natural...
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Low-Cost Automated Design of Compact Branch-Line Couplers
PublikacjaBranch-line couplers (BLCs) are important components of wireless communication systems. Conventional BLCs are often characterized by large footprints which make miniaturization an important prerequisite for their application in modern devices. State-of-the-art approaches to design of compact BLCs are largely based on the use of high-permittivity substrates and multi-layer topologies. Alternative methods involve replacement of transmission-line...
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Repeated Projectile Impact Tests on Multi-Layered FibrousCementitious Composites
PublikacjaThis research aims to experimentally evaluate the behaviour of multi-layered fibrous cementitious composites withintermediate Glass Fibre Meshes (GFM) under repeated projectile load. The impact load was subjected through a convexedge projectile needle at a low velocity on cylindrical specimens of three-layered fibrous cementitious composites, whichhave two different steel fibre distributions. In series A mixtures, a constant steel...
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Electrochemical and photoelectrochemical properties of the interface between titania nanotubes covered by conducting polymer in aqueous by conducting polymer in aqueous electrolytes – The effect of various geometry and electrolytes concentration
PublikacjaIn the present work we show the impact of nanotubes (NTs) geometry of titania utilized as a substrate in organic-inorganic systems acting as a p-n junction on efficient conversion of radiation energy into electrochemical energy. The electrolytic bath composition and electrolysis conditions were controlled in order to obtain TiO2NTs of various geometry as a result of electrochemical oxidation of titanium foil. The electrode material...
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Titania nanotubes modified by a pyrolyzed metal-organic framework with zero valent iron centers as a photoanode with enhanced photoelectrochemical, photocatalytical activity and high capacitance
PublikacjaThe paper discusses the synthesis, photoelectrochemical and electrochemical behaviour of titania nanotube arrays modified by a pyrolyzed metal-organic framework (MOF). A poly(3,4–ethylenedioxyphene) (PEDOT) matrix with an embedded inorganic network of iron hexacyanoferrate (BP) covering TiO2 nanotubes (TNT) is used as a MOF for the further sintering procedure, resulting in a novel, thin film of carbonaceous wrap supported Fe catalytic...
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The Polish adaptation of the Burnout Assessment Tool (BAT-PL) by W. Schaufeli et al.
PublikacjaAim. The study aimed to present the Polish version of the Burnout Assessment Tool (BAT-PL) by Schaufeli et al. and to assess its validity and reliability. The tool measures the core symptoms of burnout (BAT-C): exhaustion, mental distance, cognitive and emotional impairment, and its secondary symptoms (BAT-S): psychosomatic complaints and psychological distress. Method. The participants were 255 nursing staff members. The construct...
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Residents' Perception of Intangible Benefits and Costs Associated with Hosting Major Sporting Events
PublikacjaThe main purpose of this paper is to estimate on the basis of inhabitants’ perception the overall composite and aggregated scores of two major sporting events held in Ergo Arena hall, on the border of Gdańsk and Sopot, in northern Poland. The indirect aim is to identify the determinants affecting the monetary offers of the locals of the two cities. The research results unveil that major sporting events may determine the appearance...