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Wyniki wyszukiwania dla: AL MATRIX COMPOSITE
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Fabrication, microstructure and properties of Al-Si -Fe-Cu in situ composites.
PublikacjaW poszukiwaniu tanich kompozytów na bazie stopów Al powstała koncepcja otrzymywania kompozytów in situ o osnowie stopu Al-Si w reakcji ciekłego stopu Al-Si (Al-Si11, Al-Si25) z proszkiem Fe. Powstałe wydzielenia np. iglastego AlFe4Si w stopie AlSi25 o niezbyt wysokiej twardości (rys.2) stanowią skuteczne wzmocnienie stopu pod względem twardości, sztywności i wytrzymałości na ściskanie jak też obniżonej ścieralności. Jednak znaczny...
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Production of new non-matrix reference material of ethene
PublikacjaThe main objective of the research is to produce new non-matrix reference materials of ethene. The study are based on thermal decomposition of surface compound chemically bonded with the surface of glass fibers coated with thin layer of aluminum. Positivehomogeneity test, stability test and organization of inter-laboratory comparison are leading to find new non-matrix reference materials which are indispensable tools in the analysis...
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Corrosion characteristics of the AL-Si alloy after laser treatment at cryogenic conditions
PublikacjaOmówiono wpływ laserowego powierzchniowego przetapiania stopu Al-Si w warunkach kriogenicznych na jego mikrostrukturę i właściwości użytkowe. W wyniku badań korozyjnych stwierdzono zwiększenie odporności na korozję stopu Al-Siw 0,01 M roztworze H2SO4.
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Mathematical modelling: Lessons from composite indicators
PublikacjaWe discuss here composite indicators as mathematical models, which can be looked at through the lenses of the five rules discussed in this volume. Composite indicators sit between analysis and advocacy, and their use has social and political implications. For this reason, the lenses of the manifesto can be used to build them better, to make them more transparent, as well as to inspect incumbent indicators for methodological or...
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Coupled inductors based filter for matrix converters
PublikacjaThe use of the coupled inductors in the multipulse matrix converter (MC) systems is described in the paper. The possible arrangements of the system are given together with the description of their operation parameters. Moreover, the influence of the system’s topology on the output power quality is also presented. The invented converter structures evaluation results are given in the form of simulation tests acquired output waveforms...
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Otrzymywanie kompozytów in situ Al-Si-Fe-Cu
PublikacjaPrzedstawiono metodykę otrzymywania kompozytów metalowych przez mieszanie mechaniczne ciekłego Al-Si z proszkami Fe i Cu, dzięki samorzutnej reakcji zachodzącej in situ w roztopionym stopie. Przeprowadzono badania budowy kompozytów za pomocą mikroskopu SEM. Wykazano, że fazą wzmacniającą w kompozycie jest Al4SiFe (Vf=15-35%) o twardości 250-350 HV(0,02). Rozmiar i udział objętościowy fazy zbrojącej uzależniony był od sposobu odlewania...
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A framework for risk matrix design: A case of MASS navigation risk
PublikacjaRisk matrix, a tool for visualizing risk assessment results, is essential to facilitate the risk communication and risk management in risk-based decision-making processes related to new and unexplored socio-technical systems. The use of an appropriate risk matrix is discussed in the literature, but it is overlooked for emerging technologies such as Maritime Autonomous Surface Ships (MASS). In this study, a comprehensive framework...
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Al(III) and Cu(II) simultaneous foam separation: Physicochemical problems
PublikacjaSimultaneous removal of Al(III) and Cu(II) from dilute aqueous solutions by ion and precipitate flotation methods is investigated. Influence of the pH of the initial solution, the surface active collector concentration and the gas flow rate on the final removal ratio and the course of ion and precipitate flotations is presented. Results show that simultaneous flotations of Al(OH)3 and Cu(OH)2 insoluble species occur allowing to...
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Advanced Macromodel Matrix Structure Cloning for FDTD
PublikacjaWe propose an improved macromodel-based techniquefor efficient analysis of the structures based on PhotonicCrystals (PhC). The technique involves a new structure of thecoupling matrix and advanced cloning of not only the macromodel matrices, but also the coupling matrices SE and SH.The method allows one to shorten considerably the preprocessingtime, the RAM usage and also the iterating speed of performingFDTD. With this...
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Properties of Composite Oxide Layers on The Ti13Nb13Zr Alloy
PublikacjaThe development of composite oxide layers on the Ti13Nb13Zr alloy, their structure and properties have been demonstrated. Two subsequent methods were applied to prepare the composite layers. During the first stage gas oxidation produced a solid oxide layer, and subsequently oxide nanotubes were produced by using an electrochemical method. Scanning electron microscopy (SEM), chemical analysis, energy dispersive X-ray spectroscopy...
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Effect of Nb and Al on in vitro dissolution behavior and structure of Na2O-MgO CaO-P2O5 glasses
PublikacjaIn vitro dissolution, structure, and thermal properties of the glass series Na2O-MgOsingle bondCaOsingle bondNb2O5 -Al2O3-P2O5 were studied. The dissolution behavior in phosphate-buffered saline (PBS) confirmed the potential bioactive properties of tested glasses. The dissolution process was found to depend on the Al, Nb, and Mg contents. Al, respectively, suppresses the Nb and accelerates the Mg release process from the glasses....
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Experimental and Numerical Investigation of Tensile and Flexural Behavior of Nanoclay Wood-Plastic Composite
PublikacjaIn this study, the effect of wood powder and nanoclay particle content on composites’ mechanical behavior made with polyethylene matrix has been investigated. The wood flour as a reinforcer made of wood powder was at levels of 30, 40, and 50 wt.%, and additional reinforcement with nanoclay at 0, 1, 3, and 5 wt.%. Furthermore, to make a composite matrix, high-density polyethylene was used at levels of 70, 60, and 50% by weight....
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Effect of TiO2 Concentration on Microstructure and Properties of Composite Cu–Sn–TiO2 Coatings Obtained by Electrodeposition
PublikacjaIn this work, Cu–Sn–TiO2 composite coatings were electrochemically obtained from a sulfate bath containing 0–10 g/L of TiO2 nanoparticles. The effect of TiO2 particles on kinetics of cathodic electrodeposition has been studied by linear sweep voltammetry and chronopotentiometry. As compared to the Cu–Sn alloy, the Cu–Sn–TiO2 composite coatings show rougher surfaces with TiO2 agglomerates embedded in the metal matrix. The highest...
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Increasing the lifetime of engineering structures through the use of composite laggings
PublikacjaThe use of composite laggings prevents concrete (chemical and biological) corrosion. Columns coated with composite or reinforced composite are more resistant to negative environmental impact on concrete or steel. The mechanical properties of the reinforced casing also cause that these types of columns are more resistant to lateral forces. The applied casing limits carbonization of concrete and cyclical freezing and thawing with...
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DYNAMIC MECHANICAL BEHAVIOUR OF GFRP COMPOSITES WITH SiO2 NANO PARTICLES REINFORCED EPOXY MATRIX
PublikacjaDynamic mechanic (DMA) tests were performed to compare the mechanical behaviour of glass fibre reinforced epoxy laminate composites with SiO2 nanoparticle reinforced matrix. The selection of the most promising nanoparticle concentrations was considered in terms of elastic modulus and glass transition temperature. The reference specimens (0% nanoparticles) did not contain diluent accordingly the results do not allow the exact comparison...
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OpenGL accelerated method of the material matrix generation for FDTD simulations
PublikacjaThis paper presents the accelerated technique of the material matrix generation from CAD models utilized by the finite-difference time-domain (FDTD) simulators. To achieve high performance of these computations, the parallel-processing power of a graphics processing unit was employed with the use of the OpenGL library. The method was integrated with the developed FDTD solver, providing approximately five-fold speedup of the material...
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Analiza procesu asymetrycznego walcowania blachy bimetalowej Al-Cu
PublikacjaW pracy określono wpływ asymetrii prędkości obwodowej walców na wygięcie blachy bimetalowej Al-Cu. Wprowadzenie asymetrycznego procesu walcowania do wytwarzania blach bimetalowych ma na celu zwiększenie prędkości płynięcia warstwy o większym oporze odkształcenia oraz zwiększenie równomierności rozkładu odkształcenia całkowitego na warstwy pasma. Ponadto w pracy określono optymalne wartości współczynnika asymetrii av, dla których...
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Al-DIAMOND SCHOTTKY TUNNEL DIODES WITH BARRIER HEIGHT CONTROL
PublikacjaFew-nanometer-thick very highly boron-doped p-type layers were fabricated at metal-semiconductor interfaces of Schottky barrier diodes formed with aluminum on polycrystalline diamond. Preliminary results show that hermionically-assisted tunneling mechanism results in lower voltage drops at forward biasing of these diodes than expected for the Al-diamond metal-semiconductor potential barrier B. The effective barrier height Bpeff...
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Numerical simulation of laminate composite specimens failure
PublikacjaThis work presents some numerical results concerning simulation of failure of laminate composite specimens. In the article two tests to determine ultimate strength in an orthotropic layer, are considered: tension (TT1) and compression (TC1) test. The outcome is compared with experimental data provided by [9,10].
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Automotive fleet repair facility wastewater treatment using air/ZVI and air/ZVI/H2 O2 processes
PublikacjaAdvanced automotive fl eet repair facility wastewater treatment was investigated with Zero-Valent Iron/Hydrogen Peroxide (Air/ZVI/H2 O2 ) process for different process parameters: ZVI and H2 O2 doses, time, pH. The highest Chemical Oxygen Demand (COD) removal effi ciency, 76%, was achieved for ZVI/H2 O2 doses 4000/1900 mg/L, 120 min process time, pH 3.0. COD decreased from 933 to 227 mg/L. In optimal process conditions odor and...
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Contribution to the capacity analysis of the classic composite girder of Möller
PublikacjaThe analysis (brief history, experiments, numerical method) of the classic composite girder of Moller has been presented.
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Powierzchniowa obróbka laserowa stopu Al-Si w warunkach kriogenicznych
PublikacjaPrzedstawiono sposób krystalizacji metali w warunkach wolnego i ultra szybkiego chłodzenia. Wykorzystanie wiązki lasera umożliwia szybkie nadtopienie określonej warstwy materiału metalicznego, a intensywne chłodzenie sprzyja tworzeniu struktur drobnokrystalicznych, quasi krystalicznych lub amorficznych. W tym aspekcie opracowano obróbkę powierzchniową stopu Al-Si, która w znacznym zakresie zmodyfikuje właściwości użytkowe wymienionego...
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Electrochemical investigations of Al-Mg alloy subjected to tensile test
PublikacjaWykonano pomiary elektrochemiczne stopu typu Al-Mg podczas badań mechanicznych polegających na rozciąganiu badanych próbek. W trakcie badań mechanicznych wykonywano badania za pomocą metody dynamicznej spektroskopii impedancyjnej (DEIS). Stwierdzono, że podczas realizacji rozciągania próbek zachodzi proces pękania warstwy pasywnej w wyniku którego rozpoczynają się procesy korozyjne. W zakresie plastycznym podczas rozciągania zarejestrowano...
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Mechanical Properties of a Dike Formed from a Soil-ash Composite
PublikacjaThe paper presents the research results on application of composite soils for dike construction. The composite soil is produced by mixing bottom ash (by-product of energetics) with dredged material (sand) taken from the mouth of The Vistula river. The optimum composite for dike core was chosen with respect to mechanical parameters: high internal friction angle, good compaction and reduced hydraulic conductivity. The test dike was...
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Mechanizm korozji stopu Al-Si nadtapianego laserowo w niskiej temperaturze.
PublikacjaBadano odporność na korozję elektrochemiczną stopu Al-Si metodami krzywych polaryzacji i impedancji. Ujawniono wyraźny wzrost odporności na korozję stopu nadtapianego laserowo po schłodzeniu do niskiej temperatury. Zaproponowano mechanizm korozji warstwy wierzchniej stopu.
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Morphology and corrosion characteristics of laser surface remelted Al-Sialloy at cryogenic conditions
PublikacjaPrzedstawiono koncepcję obróbki laserowej stopu Al-Si w warunkach kriogenicznych. Określono jej wpływ na lokalny skład chemiczny oraz mikrostrukturę i właściwości korozyjne wymienionego stopu. Stwierdzono znaczącą poprawę właściwości korozyjnych w 0,01 M H2SO4.
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A Comparison of the Efficiency of Deammonification under Different Aeration Strategies in a Laboratory-Scale Sequencing Batch Reactor
PublikacjaAn important source of nitrogen load entering the biological part of wastewater treatment plants (WWPTs) is derived from the anaerobic sludge digestion processes. Sludge digestion liquors constitute only 1-2% of the inflow to the plant, but the load of nitrogen directed with them to the main stream may be as high as 10-20% of the total nitrogen load. Therefore, numerous studies have focused on treatment of sludge digestion liquors...
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Inhibition effect of free ammonia on deammonification process under different intermittent aeration strategies in sequencing batch reactor
PublikacjaThe deammonification process involves two steps. The first step is the partial nitrification of ammonia (NH4-N) by ammonia oxidizing bacteria (AOB) to produce nitrite (NO2-N) and the second step is the anammox process to “anaerobically” oxidize ammonia to nitrogen gas with nitrite as an electron acceptor (Lackner et al., 2014). Free ammonia (FA) plays a significant role in the stable, long-term deammonification system operation....
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On geometrically non-linear FEA of laminated FRP composite panels
PublikacjaThe paper presents a state-of-art review on Finite Element Analysis (FEA) of geometrically non-linear problems for laminated composite plates and shells made as fibre reinforced polymer (FRP) laminates. Besides a subjective overview of the historical development of geometrically non-linear FEA of laminated FRP composite panels, some remarks on possible future issues in this research area are given
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Catalytic impact of alloyed Al on the corrosion behavior of Co50Ni23Ga26Al1.0 magnetic shape memory alloy and catalysis applications for efficient electrochemical H2 generation
PublikacjaThe electrochemical and corrosion behaviour of Co50Ni23Ga27-xAlx (x = 0 and 1.0 wt%) magnetic shape memory alloys (MSMAs) was studied in 0.5 M NaCl solutions using various electrochemical techniques. Results showed remarkable activation of the tested MSMA toward pitting corrosion upon alloying it with Al. XPS examination confirmed the activation influence of alloyed Al. It proved that the presence of Al in the alloy's matrix weakens...
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Composite as a Material of the Future in the Era of Green Deal Implementation Strategies
PublikacjaComposite materials have become synonymous with modernity, desired in nearly every aspect of our daily lives, from simple everyday objects to sanitary facilities, pipelines, the construction of modern sewer networks, their renovation, water supply, and storage reservoirs, to complex structures—automotive, planes, and space science. Composites have seen a considerable rise in attention owing to their characteristics, durability,...
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Cast aluminium matrix composites modified with using FSP process – Changing of the structure and mechanical properties
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Connection matrix theory for discrete dynamical systems
PublikacjaIn [C] and [F1] the connection matrix theory for Morse decomposition is developedin the case of continuous dynamical systems. Our purpose is to study the case of discrete timedynamical systems.
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Reply to Demaria et al.
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Badania elektrochemiczne stopu Al-Mg podczas realizacji procesu rozciagania
PublikacjaW pracy wykonano badania metodą dynamicznej spektroskopii impedancyjnej (DEIS) podczas pomiarów mechanicznych polegających na rozciąganiu próbek wykonanych ze stopu typu Al-Mg aż do zerwania. Stwierdzono, że w zakresie sprężystym zachodzi zjawisko mechanicznego pękania warstwy pasywnej, mające wpływ na znaczne załamanie się właściwości barierowych warstwy i w związku z tym początek procesów korozyjnych na powierzchni. W zakresie...
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Performance of a new commercial high-definition 3D patient specific quality assurance system for CyberKnife robotic radiotherapy and radiosurgery
PublikacjaConventional two dimensional and low-definition measurement techniques for dosimetric verification of radiotherapy treatment deliveries are no longer adequate in the era of hypofractionation and extremely high dose gradients. New quality assurance (QA) tools with 3D capability and high definition are urgently needed. The purpose of this study was to evaluate the performance of one of the first such commercial systems as applied...
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A memory efficient and fast sparse matrix vector product on a Gpu
PublikacjaThis paper proposes a new sparse matrix storage format which allows an efficient implementation of a sparse matrix vector product on a Fermi Graphics Processing Unit (GPU). Unlike previous formats it has both low memory footprint and good throughput. The new format, which we call Sliced ELLR-T has been designed specifically for accelerating the iterative solution of a large sparse and complex-valued system of linear equations arising...
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Effect of surface on the flexomagnetic response of ferroic composite nanostructures; nonlinear bending analysis
PublikacjaOur analysis incorporates the geometrically nonlinear bending of the Euler-Bernoulli ferromagnetic nanobeam accounting for a size-dependent model through assuming surface effects. In the framework of the flexomagnetic phenomenon, the large deflections are investigated referring to von-Kármán nonlinearity. Employing the nonlocal effects of stress coupled to the gradient of strain generates a scale-dependent Hookean stress-strain...
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Investigation of the structural and thermal properties of aluminum-rich Ca–Al–Si–O–N glasses
PublikacjaIn this paper, we investigate the structure and thermal properties of aluminum-rich transparent Ca–Al–Si–O–N glasses. The obtained glasses were prepared by a traditional melt-quenching technique at 1650 °C using AlN as the nitrogen source. The obtained glasses have a nAl/nSi>1 and contain up to 17 eq.% of N. The structure of the glasses was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, infrared, and Raman...
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Local buckling of composite channel columns
PublikacjaThe investigation concerns local buckling of compressed flanges of axially compressed composite channel columns. Cooperation of the member flange and web is taken into account here. The buckling mode of the member flange is defined by rotation angle a flange about the line of its connection with the web. The channel column under investigation is made of unidirectional fibre-reinforced laminate. Two approaches to member orthotropic...
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Structural, thermal and physico-mechanical properties of polyurethane/brewers’ spent grain composite foams modified with ground tire rubber
PublikacjaIn this work, brewers’ spent grain (BSG) and ground tire rubber (GTR) waste fillers were applied as low-cost reinforcement phase in rigid polyurethane foam (PUR). PUR/BSG/GTR composites were prepared by a single step method, using polyglycerol as partial substitute of commercially available petrochemical polyols. Foaming parameters, chemical structure, dynamic mechanical properties, thermal stability, physico-mechanical properties...
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Wpływ wyżarzania na strefę połączenia blachy Al-Cu zgrzewanej wybuchowo i walcowanej.
PublikacjaW pracy omówiono wpływ zgniotu, czasu i temperatury wyżarzania walcowanej na zimno blachy platerowanej Al-Cu na jakość połączenia w strefie zgrzewania.
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An optimal form of the finite element mass matrix in the analysis of longitudinal vibrations of rods
PublikacjaIn this paper, an attempt is made to find the optimal form of the mass matrix of a rod finite element, which allows one to obtain the smallest errors in the longitudinal frequency determination of natural vibrations of any boundary conditions within the whole range of determined frequencies. It is assumed that the mass matrix can be treated as a linear combination of the consistent and diagonal matrices. Based on analytical considerations,...
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A Task-Scheduling Approach for Efficient Sparse Symmetric Matrix-Vector Multiplication on a GPU
PublikacjaIn this paper, a task-scheduling approach to efficiently calculating sparse symmetric matrix-vector products and designed to run on Graphics Processing Units (GPUs) is presented. The main premise is that, for many sparse symmetric matrices occurring in common applications, it is possible to obtain significant reductions in memory usage and improvements in performance when the matrix is prepared in certain ways prior to computation....
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Long-term researches of stress corrosion cracking of Al-Zn-Mg alloys
PublikacjaPraca przedstawia wyniki odporności na korozję naprężeniową stopów Al-Zn-Mg uzyskane w warunkach stacjonarnych. Dodatkowo określono wpływ składu chemicznego oraz obróbki cieplnej na odporność korozyjną tych stopów. Badania prowadzono w 3% NaCl w warunkach stałego obciążenia σ = 0.8R0.2 przez 1500 godzin. Stwierdzono, iż zawartość Zn i Mg oraz szybkość chłodzenia to główne czynniki wpływające na podatność tych stopów na korozje...
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New light on the photocatalytic performance of NH4V4O10 and its composite with rGO
PublikacjaSolar-driven photocatalysis has shown great potential as a sustainable wastewater treatment technology that utilizes clean solar energy for pollutant degradation. Consequently, much attention is being paid to the development of new, efficient and low-cost photocatalyst materials. In this study, we report the photocatalytic activity of NH4V4O10 (NVO) and its composite with rGO (NVO/rGO). Samples were synthesized via a facile one-pot...
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Influence of CeO2 and TiO2 Particles on Physicochemical Properties of Composite Nickel Coatings Electrodeposited at Ambient Temperature
PublikacjaThe Ni-TiO2 and Ni-CeO2 composite coatings with varying hydrophilic/hydrophobic characteristics were fabricated by the electrodeposition method from a tartrate electrolyte at ambient temperature. To meet the requirements of tight regulation by the European Chemicals Agency classifying H3BO3 as a substance of very high concern, Rochelle salt was utilized as a buffer solution instead. The novelty of this study was to implement a...
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Application of TOPSIS for Selection and Assessment of Analytical Procedures for Ibuprofen Determination in Wastewater
PublikacjaThis paper describes the possible implementation of the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) as green analytical chemistry metrics tools. TOPSIS is one of the multi-criteria decision analysis (MCDA) tools that is applied in the selection of the best alternative from many possible. In this case we have applied it to assess the nineteen analytical procedures for ibuprofen determination in wastewater...
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FRP-based reinforcement coatings of steel with application prospects in ships and offshore structures: a review
PublikacjaLatest research on novel FRP-based anti-corrosion structural coatings (for enhancing structural capacity and strengthening the coating layer) is discussed with application prospects for ships and offshore structures. In the marine environment, structures constantly face corrosion and fatigue cracks. Combining this with high operational and wave loads, it might cause a structural collapse. Recently, polymer composites have been...
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Some kind of joints in composite polymer bridges
PublikacjaContemporary, polymer composites bridge structures are of two types: truss or arch structures(with many joints along the length) and beam structures with limited number of joints. Both of them have special types of composite polymer decks. An ideal solution is to join advantages of two types of structuresdescribed below and create long span FRP beam bridge structure system using joints along the length. Theproblem is to find the...