Wyniki wyszukiwania dla: COMPOSITE MATERIALS
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A novel hierarchically-porous diamondized polyacrylonitrile sponge-like electrodes for acetaminophen electrochemical detection
PublikacjaA novel composite electrode material consisting of tangled fibrous polyacrylonitrile-based hierarchically-struc- tured nanocomposites has been produced by wet-spinning, carbonized and decorated with a carbon nano- architecture by microwave plasma-enhanced chemical vapor deposition and investigated as a metal-free electrode for the enhanced electrochemical detection of acetaminophen. Surprisingly, the hierarchical fiber ar- chitecture...
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Synthesis, characterization, and application of 2D/2D TiO2-GO-ZnFe2O4 obtained by the fluorine-free lyophilization method for solar light-driven photocatalytic degradation of ibuprofen
PublikacjaIn this study, we report the potential of 2D/2D TiO2- GO-ZnFe2O4 photocatalyst obtained using the fluorine-free lyophilization technique for the degradation of ibuprofen belonging to the group of active pharmaceutical ingredients (API). The improved ibuprofen degradation under simulated solar light was achieved in the presence of a composite of 2D TiO2 combined with GO and embedded ZnFe2O4, which additionally provides superparamagnetic...
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The impact of natural fibers’ characteristics on mechanical properties of the cement composites
PublikacjaThe paper reviews the properties of cement composites reinforced with short fibres. The effect of natural fibres was investigated: cotton, sisal, jute, ramie, bamboo, and synthetic fibres: polymer and polypropylene. It was noticed that the fibres change the consistency of the mixture up to 15%. In the composite flexural strength tests, a change in strength by +/− 8% was observed, depending on the type of fibres used. The research...
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Graphene oxide, reduced graphene oxide and composite thin films NO2 sensing properties
PublikacjaA graphene oxide (GO), reduced graphene oxide (RGO) and poly(3,4-ethylenedioxytiophene)- reduced graphene oxide (PEDOT-RGO composite) gas sensors were successfully fabricated using an electrodeposition method. The electrodeposition was carried out in aqueous GO dispersions. In order to obtain RGO and PEDOT-RGO, the electrochemical reduction of GO and PEDOT-GO was carried out in 0.1 M KCl at constant potential of −0.85 V. The GO, RGO...
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Cost-Efficient Design Methodology for Compact Rat-Race Couplers
PublikacjaIn this article, a reliable and low-cost design methodology for simulation-driven optimization of miniaturized rat-race couplers (RRCs) is presented. We exploit a two-stage design approach, where a composite structure (a basic building block of the RRC structure) is first optimized using a pattern search algorithm, and, subsequently, the entire coupler is tuned by means of surrogate-based optimization (SBO) procedure. SBO is executed...
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Towards Computer-Aided Graphene Covered TiO2-Cu/(CuxOy) Composite Design for the Purpose of Photoinduced Hydrogen Evolution
PublikacjaIn search a hydrogen source, we synthesized TiO2-Cu-graphene composite photocatalyst for hydrogen evolution. The catalyst is a new and unique material as it consists of copper-decorated TiO2 particles covered tightly in graphene and obtained in a fluidized bed reactor. Both, reduction of copper from Cu(CH3COO) at the surface of TiO2 particles and covering of TiO2-Cu in graphene thin layer by Chemical Vapour Deposition (CVD) were...
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Sensitivity analysis as a tool to optimise Human Development Index
PublikacjaResearch background: Composite indicators are commonly used as an approximation tool to measure economic development, the standard of living, competitiveness, fairness, effectiveness, and many others being willingly implemented into many different research disciplines. However, it seems that in most cases, the variable weighting procedure is avoided or erroneous since, in most cases, the so-called...
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Effect of porosity on physical properties of lightweight cement composite with foamed glass aggregate
PublikacjaThis paper reports on a study of physical properties of lightweight cement composite. We investigate the possibility of replacing traditional aggregate with Granulated Ash Aggregate (GAA) and above all with Granulated Expanded Glass Aggregate (GEGA). For this purpose, 15 specimens of different percentage share of each aggregate in total aggregate volume were tested: 0%, 25%, 50%, 75% or 100% of foam glass aggregate (GEGA) partially...
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Lead-free bismuth-based perovskites coupled with g–C3N4: A machine learning based novel approach for visible light induced degradation of pollutants
PublikacjaThe use of metal halide perovskites in photocatalytic processes has been attempted because of their unique optical properties. In this work, for the first time, Pb-free Bi-based perovskites of the Cs3Bi2X9 type (X = Cl, Br, I, Cl/Br, Cl/I, Br/I) were synthesized and subjected to comprehensive morphological, structural, and surface analyses, and photocatalytic properties in the phenol degradation reaction were examined. Furthermore,...
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The bridge over Regalia River in Szczecin - design and construction.
PublikacjaNowoclowa Route is the largest projekt in Szczecin, that consists of 11 km of roads 3,3 km bridges and viaducts, including three parallel bridges across Regalica River (the east arm of Odra River), 535 m long, with the spans: 59+90+90+116+116+64m. The bridge structure consist of two steel plate girders composite with reinforced concrete deck slab. The design and the construction of the bridge are described in the paper.
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Composite sandwich footbridge - measured dynamic response vs. FEA
PublikacjaThe paper describes a process of in situ dynamic tests of a composite sandwich footbridge before its accepta-tion for exploitation in real traffic conditions. It is only a part of a big research task that includes design, manufacture and introduce practical application of the bridge. The in situ measured natural modes and fre-quencies are compared with numerically determined ones. Finite element analysis is established to estimate...
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Characteristics of La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3-δ -supported micro-tubular solid oxide fuel cells with LaCo 0.4 Ni 0.6-x Cu x O 3-δ cathodes
PublikacjaIn this study, micro-tubular solid oxide fuel cells (T-SOFCs) with extruded La0.8Sr0.2Ga0.8Mg0.2O3-δ (LSGM) electrolyte as the mechanical support and LaCo0.4Ni0.6O3-δ (LCNO) or LaCo0.4Ni0.4Cu0.2O3-δ (LCNCO) as cathodes were prepared and characterized. Partial substitution of Cu for the Ni-ion positions in the LCNO lattices was found to significantly enhance the densification and accelerate the grain growth. The porosity-corrected...
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Clay-filled starch films. Part I: Effect of clay kind and glycerol concentration on functional properties of composites
PublikacjaThe aim of this work was to improve the mechanical and water barrier properties of composite filmsprepared from starch and clays, plasticized with glycerol at different concentrations. The effects ofhydrophilic Closite Naþand Nanomer PGV were compared with that exerted by organicallymodifiedmorehydrophobicNanofil2 and NanoBent ZR-1. The antimicrobial activity of compositescontaining hydrophobic clays was also investigated. The hydrophilic...
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Evaluation of high-frequency roughness measurement errors for composite and ceramic surfaces after machining
PublikacjaPrecise characterisation of surface topography is of the greatest importance since many factors directly affect the accuracy of the whole measurement process. In this paper, the variety of surface topographies from machined composite and ceramic workpieces was studied with a special emphasis on the measurement results. Surfaces were subjected to the ground diamond, honing and milling processes. Measurement results were analysed...
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Computations of critical load value of composite shell with random geometric imperfections
PublikacjaThe work presents the numerical analysis of composite shell with geometric imperfections subjected to compression along its generatrix. The imperfections are described as single indentations and random fields with random parameters of shape and correlation. The fields are generated with the use of the authors made program. Using the authors’ FEM software as well as commercial package Femap with NX Nastran, the critical load values...
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Determination of Chemical Diffusion Coefficient of Lithium Ions in Ceramics Derived from Pyrolysed Poly(1,2-dimethylsilazane) and Starch
PublikacjaThe apparent chemical diffusion coefficient Li+ (DappLI+) in pyrolysed poly(1,2-dimethylsilazane)/starch (PSN/S) (weight ratio: 30/70) ceramic anode composite is determined by galvanostatic intermittent titration technique (GITT). The electrode material composition is C6.00N0.14H0.47O0.12Si0.13. The calculated values of DappLI+, depend on the applied potential, vary from 10-14 to 10-9 [cm2/s]. The diffusion coefficient of lithium...
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Solid Oxide Fuel Cells with Ni infiltrated perovskite anode
PublikacjaNiobium-doped strontium titanate was used as the anode for a solid oxide fuel cell. Electrolyte-supported cells were prepared with pure perovskite and composite perovskite–yttria–stabilized-zirconia (YSZ) anodes. Fuel cell tests demonstrated significant improvement in power density after infiltration with a small amount of Ni. The obtained values of power densities are comparable with conventional Ni/YSZ cermet anode. In addition,...
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Magnetically recyclable TiO2/MXene/MnFe2O4 photocatalyst for enhanced peroxymonosulphate-assisted photocatalytic degradation of carbamazepine and ibuprofen under simulated solar light
PublikacjaIn this study, a novel TiO2/Ti3C2/MnFe2O4 magnetic photocatalyst with dual properties, enabling (i) improved photocatalytic degradation with PMS activation under simulated solar light and (ii) magnetic separation after the degradation process in an external magnetic field was developed and applied for the efficient photodegradation pharmaceutically active compounds (PhACs) frequently present in wastewater and surface waters worldwide. MXene...
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Dynamic Tests and Technical Monitoring of a Novel Sandwich Footbridge
PublikacjaA novel sandwich composite footbridge is described in this paper, for the first time after it has been put into operation over the Radunia River in the Pruszcz Gdański municipality. This paper presents results of dynamic tests and describes technical monitoring of the footbridge. The dynamic tests were conducted to estimate pedestrian comfort and were compared with the ones from numerical simulations made in the environment of...
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Electrochemical Activity of Electrode Material Consisting of Porous Copper and Silica Aerogel
PublikacjaElectrochemically obtained copper was combined with silica aerogel (SiO2ag). Obtained composite (SiO2@Cu/CuxOy) was tested as an electrode in contact with LiPF6 in EC/DMC electrolyte. The electrochemical measurements showed the presence of complex redox couple activities of SiO2@Cu/CuxOy. This experiment was employed to help in understanding the carbon role used as an electric contact for silica in Li-Ion batteries and clarify...
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Collective Uncertainty Entanglement Test
PublikacjaFor a given pure state of a composite quantum system we analyze the product of its projections onto aset of locally orthogonal separable pure states. We derive a bound for this product analogous to theentropic uncertainty relations. For bipartite systems the bound is saturated for maximally entangled statesand it allows us to construct a family of entanglement measures, we shall call collectibility. As thesequantities are experimentally...
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The influence of polarization of titania nanotubes modified by a hybrid system made of a conducting polymer PEDOT and Prussian Blue redox network on the Raman spectroscopy response and photoelectrochemical properties
PublikacjaIn this work we show the impact of applied potential on network vibrations and photoelectrochemical properties of a composite material containing hydrogenated titania nanotubes and poly (3,4-ethylenedioxythiophene) with iron hexacyanoferrate (H-TiO2/pEDOT:Fehcf) acting as a redox centre. For this purpose, Raman spectroscopy measurements under the working electrode (WE) polarization were carried out, allowing investigation of changes...
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Formation of Highly Conductive Boron-Doped Diamond on TiO2 Nanotubes Composite for Supercapacitor or Energy Storage Devices
PublikacjaIn the present paper, we report the phenomena of the formation of the novel composite nanostructures based on TiO2 nanotubes (NTs) over-grown by thin boron-doped diamond (BDD) film produced in Microwave Plasma Enhanced Chemical Vapor Deposition (PE MWCVD). The TiO2 nanotube array overgrown by boron-doped diamond immersed in 0.1 M NaNO3 can deliver high specific capacitance of 7.46 mF cm−2. The composite electrodes were characterized...
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Material Design and Optimisation of Electrochemical Li-Ion Storage Properties of Ternary Silicon Oxycarbide/Graphite/Tin Nanocomposites
PublikacjaIn this work, we present the characterization and electrochemical performance of various ternary silicon oxycarbide/graphite/tin (SiOC/C/Sn) nanocomposites as anodes for lithium-ion batteries. In binary SiOC/Sn composites, tin nanoparticles may be produced in situ via carbothermal reduction of SnO2 to metallic Sn, which consumes free carbon from the SiOC ceramic phase, thereby limiting the carbon content in the final ceramic nanocomposite....
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Development of novel optoelectronic sensory structures utilising colour centres in nanodiamonds and their interactions with analytes
PublikacjaThe goal of this dissertation was to develop and assess surface modifications of fluorescent nanodiamonds (NDs) for optical sensing. Three modification routes were tested, each aimed at a different application. Modification with poly-L-lysine (pLys) was verified for optical sensing of pH via an interrelationship between electrically negative (NV¯) and neutral (NV0) nitrogen-vacancy centres. Immobilisation of Ochratoxin A (OTA),...
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Development of novel (BiO)2OHCl/BiOBr enriched with boron doped-carbon nanowalls for photocatalytic cytostatic drug degradation: Assessing photocatalytic process utilization in environmental condition
PublikacjaIn this work, a series of novel (BiO)2OHCl/BiOBr-x%B:DGNW (x = 0%, 1%, 1.5%, 2%) composites with different content of boron-doped diamond/graphene nanowalls (B:DGNW) were fabricated by simple solvothermal synthesis. A boron-doped diamond/graphene nanowalls (B:DGNW) were prepared by CVD method. A series of analyses: XRD, XPS, SEM, and TEM showed that the photocatalyst (BiO)2OHCl/BiOBr-x%B:DGNW with a “flower-like” morphology was...
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Conductive printable electrodes tuned by boron-doped nanodiamond foil additives for nitroexplosive detection
PublikacjaAn efficient additive manufacturing-based composite material fabrication for electrochemical applications is reported. The composite is composed of commercially available graphene-doped polylactide acid (G-PLA) 3D printouts and surface- functionalized with nanocrystalline boron-doped diamond foil (NDF) additives. The NDFs were synthesized on a tantalum substrate and transferred to the 3D-printout surface at 200 °C. No other electrode...
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Heterojunction of (P, S) co-doped g-C3N4 and 2D TiO2 for improved carbamazepine and acetaminophen photocatalytic degradation
PublikacjaNovel photocatalysts of phosphorus and sulfur co-doped graphitic carbon nitride incorporated in 2D TiO2 structure were successfully fabricated and applied for solar-driven degradation of emerging pollutants from the group of pharmaceuticals not susceptible to biodegradation. The hybrid photocatalysts with different loadings of (P, S)-doped g-C3N4 were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR),...
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A novel sandwich footbridge - Practical application of laminated composites in bridge design and in situ measurements of static response
PublikacjaA novel sandwich composite footbridge is presented in the paper, as an example of practical application of laminated composites in civil engineering. The in situ static load tests of the footbridge before its acceptation for exploitation are shown and discussed. The results are compared with the corresponding ones from a numerical equivalent single layer model of the sandwich structure created within the framework of finite element...
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Titania nanotubes infiltrated with conducting polymer PEDOT modified by Prussian Blue – a novel type of organic-inorganic heterojunction characterised with enhanced photoactivity.
PublikacjaA highly ordered p–n heterojunction was formed based on titania nanotubes containing a conducting polymer with Prussian blue matrix. The study demonstrates, for the first time, cases when a composite based on titania array scaffolding and Prussian blue embedded in PEDOT exhibits reversible FeII/FeIII redox activity. Highly enhanced photoactivity and capacitance of the obtained material are depicted in comparison to pristine titania....
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BADANIA KOMPOZYTOWEGO MOSTU DLA PIESZYCH
PublikacjaThe paper presents in situ load testing of the innovative footbridge of FOBRIDGE grant mounted at Gdansk University of Technology. The span of composite sandwich structure (GFRP skins, PET core) and the scope of static and dynamic tests are presented. The selected, representative results of in situ measurements and data obtained from the SHM monitoring system are discussed. Besides the standard testing procedures on the full scale...
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Tripping limitations of residual current devices in photovoltaic installations
PublikacjaIn electrical installations with photovoltaic sources of energy, earth fault current may comprise alternating current component and direct current component. The waveform shape of this earth fault current mainly depends on the point of the fault and the properties of a photovoltaic power electronics converter. The waveform shape of the current influences operation of protection devices, especially tripping threshold of residual...
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Rapid EM-Driven Design of Compact RF Circuits By Means of Nested Space Mapping
PublikacjaA methodology for rapid design of RF circuits constituted by compact microstrip resonant-cells (CMRCs) is presented. Our approach exploits nested space mapping (NSM) technology, where the inner SM layer is used to correct the equivalent circuit model at the CMRC level, whereas the outer layer enhances the coarse model of the entire structure under design. We demonstrate that NSM dramatically improves performance of surrogate-based...
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The influence of rubber recyclate morphology on the properties of rubber-asphalt composite
PublikacjaIn the paper wastes, mostly in the form of used tires, were analyzed. One of the methods of waste tires application use them as a modifier of asphalt. However, the properties of rubber-asphalt composites depend on the morphology of waste tiregranulate and kind of tire recycled (car/truck). In this chapter, the influence of grinding methods of waste tire on the prop¬erties of rubber-asphalt composites were studied. SEM analysis...
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RMS-based damage identification in adhesive joint between concrete beam and steel plate using ultrasonic guided waves
PublikacjaAdhesive joints have numerous applications in many branches of industry, such as civil engineering, automotive, aerospace and shipbuilding. As with most structural elements, adhesive joints can experience any damage mechanism, which induces the need for diagnostic testing. Ultrasonic waves are widely used for non-destructive inspection of many structures and their elements, including adhesive joints. Guided wave propagation method...
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A Generalized Framework Towards Structural Mechanics of Three-layered Composite Structures
PublikacjaThree-layered composite structures find a broad application. Increasingly, composites are being used whose layer thicknesses and material properties diverge strongly. In the perspective of structural mechanics, classical approaches to analysis fail at such extraordinary composites. Therefore, emphasis of the present approach is on arbitrary transverse shear rigidities and structural thicknesses of the individual layers. Therewith...
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Influence of windsurfing fin stiffness distribution on the lift-drag characteristics
PublikacjaThis article addresses the problem of determining the hydromechanical loads generated by flexible hydrofoils. The research was done on the example of the composite windsurfing fin for the RS:X monotype class. Despite the assumption of fins identity, everyday practice showed that variations of mechanical properties occur and strongly affect their performance. Therefore, we decided to study the differences between the windsurfing...
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Experimental Study on the Effectiveness of Polyurethane Flexible Adhesive in Reduction of Structural Vibrations
PublikacjaThe aim of the present study is to consider the idea of using polyurethane flexible adhesive in to reduce the vibrations in structures exposed to dynamic loads and evaluate their damping properties in relation to large deformations. Firstly, two aluminium cantilever beams, simulating structural elements (without and with polyurethane layer in the form of tape), were analysed, in order to check the damping of the unconstrained polymer...
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The Effect of AgInS2, SnS, CuS2, Bi2S3 Quantum Dots on the Surface Properties and Photocatalytic Activity of QDs-Sensitized TiO2 Composite
PublikacjaThe eect of type (AgInS2, SnS, CuS2, Bi2S3) and amount (5, 10, 15 wt%) of quantum dots (QDs) on the surface properties and photocatalytic activity of QDs-sensitized TiO2 composite, was investigated. AgInS2, SnS, CuS2, Bi2S3 QDs were obtained by hot-injection, sonochemical, microwave, and hot-injection method, respectively. To characterize of as-prepared samples high-resolution transmission electron microscopy (HRTEM), scanning...
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Composite Sandwich Footbridge – Numerical ESL FEM Calculations vs. In Situ Measurements
PublikacjaSelected results of the static analysis of composite sandwich footbridge with the corresponding in situ measured values are compared in the paper. The analysed bridge is a research object, which was built in 2015 and is currently located at the Gdańsk University of Technology campus. Since it is a novel structure, a proper definition of the bridge numerical model, allowing its safe design, is very important. Therefore, instead...
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Insights into baby disposable diapers sustainable application
PublikacjaThe sustainable use of baby disposable diapers is one of the issues currently being discussed to reduce the undesirable impact on the environment and improve the public's understanding of the proper use of diapers. This issue is a step toward promoting a cleaner, greener, and waste-less environment. In this article, the authors discuss options for a viable future for both people and the planet. We believe that it inspire others...
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Distortional buckling of composite thin-walled columns of a box-type cross section with diaphragms
PublikacjaDistortional buckling of axially compressed columns of box-like composite cross sections with andwithout internal diaphragms is investigated in the framework of one-dimensional theory. The channel membersare composed of unidirectional fibre-reinforced laminate. Two approaches to the member orthotropic materialare applied: homogenization based on the theory of mixture and periodicity cells, and homogenization basedon the Voigt–Reuss...
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Sensitivity analysis in design process of sandwich U-shaped composite footbridge
PublikacjaThe structure of the sandwich composite footbridge of a 14 metre span length and U-shaped cross-section was analysed. Sensitivity analysis was performed to support the design process of this innovative object. Linear discrete sensitivity analysis was performed by means of finite element method. The influence of vari-ation of several design variables i.e. thicknesses of inner and outer laminates on the mid-span deflection, as-sumed...
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Transformation of bimetallic Ag–Cu thin films into plasmonically active composite nanostructures
PublikacjaFormation of plasmonically active silver, copper and composite silver-copper nanostructures were studied in this paper. Metallic nanostructures were fabricated by thermal disintegration, so called dewetting, of the thin films in an argon atmosphere. The formation process of the nanostructures was in-situ observed by a novel method, based on resistance measurements. The influence of the material and thickness of the initial thin...
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Investigation of behaviour of metal structures with polymer dampers under dynamic loads
PublikacjaA large number of accidents concerning structures subjected to dynamic loads have been recently observed. One of the examples of such a structure is a temporary steel grandstand erected using scaffolding system. Dynamic load that is generated by crowd movement has a significant influence on the behaviour of the structure and may lead to excessive structural vibrations. The aim of the study is to consider the idea of using polymer...
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On a 3D material modelling of smart nanocomposite structures
PublikacjaSmart composites (SCs) are utilized in electro-mechanical systems such as actuators and energy harvesters. Typically, thin-walled components such as beams, plates, and shells are employed as structural elements to achieve the mechanical behavior desired in these composites. SCs exhibit various advanced properties, ranging from lower order phenomena like piezoelectricity and piezomagneticity, to higher order effects including flexoelectricity...
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Fully enzymatic mediatorless fuel cell with efficient naphthylated carbon nanotube-laccase composite cathodes
PublikacjaAn efficient, mediator-free enzymatic glucose/O2 biofuel cell with an oxygen intensive anode based on glucose dehydrogenase is presented. In the device,the power of the biofuel cell and electrode potentials of each of the enzymatic electrodes were monitored in parallel under the biofuel cell working conditions. The carbon nanotube composite biocathode demonstrates an almost constant electrode potential vs. saturated calomel electrode...
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Experimental and numerical analysis of an aluminum cantilevered beam with polymer adhesive
PublikacjaIn this paper, experimental and numerical investigation on a composite cantilevered aluminum beam has been conducted. The subject of the study consists of two plain aluminum elements bonded with polymer adhesive of different thickness. It has been proven in the previous study that this kind of material has high damping properties. During an experimental investigation, value of damping ratios have been obtained. The aim of a numerical...
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Gas sensors based on conducting polymers-recent developments
PublikacjaThis work discusses sensing performance dependence of PEDOT polymer and its composites on the counter ions used in the polymerization process. The sensors based on PEDOT-RGO composite show reversible response to NO2, while on PEDOT/LiClO4 irreversible. As a result, PEDOT-RGO could be used as a typical gas sensor, while sensor based PEDOT/LiClO4 could be used as an integrating gas sensor, also known as an accumulating gas sensor....
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Nested Space Mapping Technology for Expedite EM-driven Design of Compact RF/microwave Components
PublikacjaA robust simulation-driven methodology for rapid and reliable design of RF/microwave circuits comprising compact microstrip resonant cells (CMRCs) is presented. We introduce a nested space mapping (NSM) technology, in which the inner space mapping layer is utilized to improve the generalization capabilities of the equivalent circuit model corresponding to a constitutive element of the circuit under consideration. The outer layer...