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Wyniki wyszukiwania dla: Graphene oxides
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Effect of Particle Size of Fly Ash Microspheres (FAMs) on the Selected Properties of Concrete
PublikacjaThis paper presents the investigations of selected properties of concrete containing two fractions of fly ash microspheres (FAMs) with grain size up to 200 μm and up to 500 μm. Concrete mixtures with ordinary Portland cement and three substitution rates of cement by FAMs, 1.3%, 2.0%, and 2.6%, were investigated. For all concrete mixes, the constant water–binder ratio (w/b) equal to 0.50 was used. The research program included the...
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Origin and fate of nanoparticles in marine water – Preliminary results
PublikacjaThe number, morphology and elemental composition of nanoparticles (<100 nm) in marine water was investigated using Variable Pressure Scanning Electron Microscopy (VP-SEM) and Energy-dispersive X-ray spectroscopy (EDS). Preliminary research conducted in the Baltic Sea showed that the number of nanoparticles in seawater varied from undetectable to 380 (x102) cm-3. Wind mixing and density barriers (thermocline) had a significant impact...
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New plasmonic platform for enhanced luminescence of Valrubicin
PublikacjaLuminescence enhanced by new structure of plasmonic platform with aluminum oxide (Al2O3) buffer layer deposited on gold nanostructures is investigated. Regularly distributed gold nanostructures of average dimension of 50 nm formed the active part of plasmonic platforms. They were manufactured on Corning 1737 glass substrate by melting of gold thin film. The nanostructures were coated by dielectric Al2O3 thin film with thickness...
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Experimental and numerical evaluation of mechanical behaviour of composite structural insulated wall panels under edgewise compression
PublikacjaA composite structural insulated sandwich panel (CSIP) is a quite novel approach to the idea of sandwich structures. A series of natural-scale experimental test is required each time a change in panel’s geometry is planned and a reliable computational tool is required to precede actual laboratory testing with virtual simulations. An attempt of creating such a tool has been made with use of a commercial FEM code ABAQUS, in order...
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A simplified behavioral MOSFET model based on parameters extraction for circuit simulations.
PublikacjaThe paper presents results on behavior modeling of general purpose Metal-Oxide Semiconductor Field-Effect Transistor (MOSFET) for simulation of power electronics systems requiring accuracy both in steady-state and in switching conditions. Methods of parameters extraction including nonlinearity of parasitic capacitances and steady-state characteristics are based on manufacturer data sheet and externally measurable characteristics....
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Relationship between heart rate variability, blood pressure and arterial wall properties during air and oxygen breathing in healthy subjects
PublikacjaPrevious studies reported that normobaric hyperoxia influences heart rate, arterial pressure, cardiac output and systemic vascular resistance, but the mechanisms underlying these changes are still not fully understood. Several factors are considered including degeneration of endothelium-derived nitric oxide by reactive oxygen species, the impact of oxygen-free radicals on tissues and alterations of autonomic nervous system function....
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Properties of Nasicon-based CO2 sensor with Bi8Nb2O17 reference electrode
PublikacjaGas sensors are useful for the carbon dioxide concentration monitoring in many applications. The major challenge is to develop a potentiometric sensor working without the necessity of a reference gas and without a need of the reference electrode encapsulation. Important issue is a selection of reference electrode material, which should provide stable reference potential. For example as reference electrode material in sensor based...
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Unexpected Z/E isomerism of N-methyl-O-phosphothioyl benzohydroxamic acids, their oxyphilic reactivity and inertness to amines
PublikacjaThiophosphinoylation of N-methyl p-substituted benzohydroxamic acids using disulfanes (method A) or diphenylphosphinothioyl chloride (method B) provides only one conformer of the respective O-phosphothioyl derivative (Xray and NMR analysis). Undergoing the P-transamidoxylation reaction is an evidence of the reversibility of thiophosphinoylation. Only those products containing strong EWG substituents in the aroyl residue or bulky...
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A Formal Approach to Model the Expansion of Natural Events: The Case of Infectious Diseases
PublikacjaA formal approach to modeling the expansion of natural events is presented in this paper. Since the mathematical, statistical or computational methods used are not relevant for development, a modular framework is carried out that guides from the external observation down to the innermost level of the variables that have to appear in the future mathematical-computational formalization. As an example we analyze the expansion of Covid-19....
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Near-Infrared III Nanophosphorswith Cr3+Ni2+ Energy Transfer for Bioimaging
Dane BadawczeIn the biomedical field, the use of fluorescence imaging in the second near-infrared (NIR-II) region is growing rapidly because it imparts the advantages of reduced autofluorescence and low photon scattering. The advantage of reduced scattering is that it increases penetration depth in vivo and improves imaging clarity. Herein, this work uses mesoporous...
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Influence of fasteners and connections flexibility on deflections of steel building including the stressed skin effect
PublikacjaThe paper presents the analysis of the influence of fasteners and connections flexibility on displacements of symmetrical single-bay pitched-roof steel building, including trapezoidal cladding acting as a diaphragm. The purpose of the article was to compare numerical models with and without taking into consideration fasteners and connections flexibility in order to observe the differences in transverse stiffness of the building...
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Białowieża primeval forest as an example of transfrontier co-operation between Poland and Bielarus
PublikacjaThe Polish Ministry of Foreign Affairs is completing their work on the agreement on local border traffic (May 2009.) At the final stage of the works, the list of the towns and villages situated within the area covered by the so-called "local traffic" on both the Polish and the Belarusian sides of the border is being verified. The "border belt" area, whose residents will be able to move between the bordering countries under the...
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Micro-cracking pattern recognition of hybrid CNTs/GNPs cement pastes under three-point bending loading using acoustic emission technique
PublikacjaThe generation of microcracks has an important influence on the behaviour of concrete structures. In this study, the acoustic emission (AE) technique was used to investigate the fracture phenomena and micro-cracking behavior of hybrid carbon nanotubes (CNTs, the 1-D allotrope of carbon atoms) and graphene nanoplatelets (GNPs, 2D monolayer of sp2-hybridized carbon atoms), cement composites under three-point bending loading. In...
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ZnO ALD-Coated Microsphere-Based Sensors for Temperature Measurements
PublikacjaIn this paper, the application of a microsphere-based fiber-optic sensor with a 200 nm zinc oxide (ZnO) coating, deposited by the Atomic Layer Deposition (ALD) method, for temperature measurements between 100 and 300°C, is presented. The main advantage of integrating a fiber-optic microsphere with a sensing device is the possibility of monitoring the integrity of the sensor head in real-time, which allows for higher accuracy during...
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Does the low optical band gap of yellow Bi3YO6 guarantee the photocatalytical activity under visible light illumination?
PublikacjaBi3YO6, which is known as an ionic conductor, was tested here as an electrode and photoanode in contact with aqueous electrolytes. Bi3YO6 was deposited onto the Pt substrate and the such prepared electrode was polarized in various aqueous electrolytes. The optical energy band gap of the material equal to 1.89 eV was determined using the Kubelka-Munk function resulting from the UV-Vis spectrum (allowed indirect transition) and also...
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Evaluation of adhesive forces and the specific surface energy of zirconia stabilized by yttria with alumina additions ceramic by AFM method
PublikacjaThe adhesive forces and the specific surface energy of ceramic material surfaces are very important for further tribological and biomedical applications of ceramics. Partially stabilized zirconia (zirconium oxide) is popular for manufacturing various medical products. ZrO2 stabilized by Y2O3 with additions of 5 wt% alumina was produced by slip casting method with a subsequent sintering. Structure and chemical composition of ceramic...
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OPTIMALIZATION OF SORBENT FEEDING IN THE DRY METHOD OF FLUE GAS DESULFURIZATION
PublikacjaThe swiftly developing sea transport contributes to a considerable increase of fuel usage in the international shipping, which results in the escalation of toxic compounds emitted into the atmosphere. It is followed by the constantly heightened requirements limiting those emissions. In the case of sulfur oxide emission, inside of SECA (Sulfur Emission Control Area), the maximum content of sulfur in the shipping fuels used on the...
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Protein thermal stabilization in aqueous solutions of osmolytes
PublikacjaProteins’ thermal stabilization is a significant problem in various biomedical, biotechnological, and technological applications. We investigated thermal stability of hen egg white lysozyme in aqueous solutions of the following stabilizing osmolytes: Glycine (GLY), N-methylglycine (NMG), N,N-dimethylglycine (DMG), N,N,N-trimethylglycine (TMG), and trimethyl-N-oxide (TMAO). Results of CD-UV spectroscopic investigation were compared...
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Spectral reflectance modeling of ZnO layers made with Atomic Layer Deposition for application in optical fiber Fabry-Perot interferometric sensors
PublikacjaSuitability of zinc oxide (ZnO) layers grown using Atomic Layer Deposition for operation in optical-fiber extrinsic Fabry-Perot sensors is investigated using a numerical model. Reflectance spectra obtained using the developed model indicate that the application of these layers in optical-fiber extrinsic Fabry-Perot sensors is difficult as it may require a source whose spectrum width is about 300 nm. A series of ZnO layers grown...
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Interaction of SrTi0.65Fe0.35O3-δ with LaNi0.6Fe0.4O3-δ, La0.6Sr0.4Co0.2Fe0.8O3-δ and Ce0.8Gd0.2O2-δ
PublikacjaIron doped strontium titanates SrTi1-xFexO3-δ are perovskites of versatile properties. They can be used in solid oxide fuel cells or high temperature oxygen sensors. Their reactivity with electrolyte materials, cathode buffer layer materials, other cathode materials or current collector layers has not been fully tested. In this study we use X-ray diffraction to check SrTi0.65Fe0.35O3-δ compatibility with Ce0.8Gd0.2O2-δ (used as...
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Synthesis, single crystal growth and properties of Sr5Pb3ZnO12
PublikacjaAbstract The novel Sr5Pb3ZnO12 oxide was synthesized by the solid-state reaction method. The crystal structure was studied by means of the powder x-ray diffraction Rietveld method and was found to be similar to 3 other previously known Sr5Pb3MO12 compounds (M = Co, Ni, Cu). Crystals of several hundred microns in size of the new phase were grown in molten sodium chloride and imaged using confocal optical and scanning electron microscopy....
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High temperature corrosion resistance of porous hastelloy alloy
PublikacjaTo further understand the suitability of Ni-Cr-base alloy for solid oxide fuel cell (SOFC), a commercial Ni-Cr-Fe-Mo alloy, Hastelloy X was selected and evaluated for oxidation behaviour under high temperature conditions. HastelloyX was chosen due to its unusual resistance to oxidizing, reducing and neutral atmospheres. For long term stability of metal supported fuel cell, the corrosion resistance plays a vital role and must be...
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Peroxymonosulfate-assisted photocatalytic degradation of artificial sweeteners in water
PublikacjaIn the present study, peroxymonosulfate (PMS) activation was proposed for efficient photocatalytic degradation of aspartame, acesulfame, saccharin, and cyclamate - artificial sweeteners frequently present in wastewaters and surface waters worldwide. The TiO2 nanosheets with exposed {0 0 1} facets were synthesised using the fluorine-free lyophilisation technique as a green concept for the synthesis and used for the photodegradation...
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Microfluidic devices for photo-and spectroelectrochemical applications
PublikacjaThe review presents recent developments in electrochemical devices for photo- and spectroelectrochemical investigations, with the emphasis on miniaturization (i.e., nanointerdigitated complementary metal-oxide-semiconductor devices, micro- and nano-porous silicon membranes or microoptoelectromechanical systems), silica glass/microreactors (i.e., plasmonic, Raman spectroscopy or optical microcavities) or polymer-based devices (i.e.,...
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Microsphere structure application for supercapacitor in situ temperature monitoring
PublikacjaConstant, real-time temperature monitoring of the supercapacitors for efficient energy usage is in high demand and seems to be crucial for further development of those elements. A fiber-optic sensor can be an effective optoelectronic device dedicated for in-situ temperature monitoring of supercapacitors. In this work, the application of the fiber-optic microstrucutre with thin zinc oxide (ZnO) coating fabricated in the atomic layer...
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A Comprehensive Experimental and Theoretical Study on the[{(η5-C5H5)2Zr[P(µ-PNEt2)2P(NEt2)2P]}2O Crystalline System
PublikacjaThe structure of tetraphosphetane zirconium complex C52H100N8OP10Zr21 was determined by single crystal X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P21/c, with a = 19.6452(14), b = 17.8701(12), c = 20.7963(14)Å, α = γ = 90°, β = 112.953(7)°, V = 6722.7(8)Å3, Z = 4. The electronic structure of the organometallic complex has been characterized within the framework of Quantum Chemical Topology....
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New synthesis route of highly porous InxCo4Sb12 with strongly reduced thermal conductivity
PublikacjaHighly porous, In-filled CoSb3 skutterudite materials with an attractive thermoelectric figure of merit (ZT * 1) and corresponding dense samples were fabricated through the cost-effective method of reduction in oxides in dry hydrogen and the pulsed electric current sintering (PECS) method, respectively. The reduction process was described in detail using in situ thermogravimetric analysis of Co2O3, Sb2O3 and In(NO3)35H2O separately...
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Lanthanide co-doped TiO2: the effect of metal type and amount on surface properties and photocatalytic activity
PublikacjaPreparation of new rare earth metal-containing TiO2 nanocomposites (Nd3+/Er3+, Nd3+/Eu3+, Eu3+/Ho3+-TiO2) using sol–gel route and their photoactivity under visible and ultraviolet light is reported. The obtained photocatalysts were subsequently characterized by Brunauer–Emmett–Teller (BET) method, UV–Vis diffuse-reflectance spectroscopy (DRS), luminescence spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray powder diffraction...
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Ball milling treatment of Mn3O4 regulates electron transfer pathway for peroxymonosulfate activation
PublikacjaHeterogeneous metal catalysts have attracted considerable interest in advanced oxidation processes (AOPs) for wastewater treatment by activating peroxymonosulfate (PMS). However, it remains challenging to the rational design of efficient reaction pathway for high-performance contaminants removal by regulating the inherent structure of metal oxides. Herein, a high-energy ball milling method was employed to modulate the electronic...
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The Influence of the Electrodeposition Parameters on the Properties of Mn-Co-Based Nanofilms as Anode Materials for Alkaline Electrolysers
PublikacjaIn this work, the influence of the synthesis conditions on the structure, morphology, and electrocatalytic performance for the oxygen evolution reaction (OER) of Mn-Co-based films is studied. For this purpose, Mn-Co nanofilm is electrochemically synthesised in a one-step process on nickel foam in the presence of metal nitrates without any additives. The possible mechanism of the synthesis is proposed. The morphology and structure...
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Numerical simulation of cold flow and combustion in a swirl stabilized combustor
PublikacjaA numerical simulation model was developed to investigate the cold flow and combustion using Ansys FLUENT 2021R1. The governing equations were solved using the pressure-based method, and pressure–velocity coupling was performed using the SIMPLE method. To model the turbulent process, the RSM model was used. Non-premixed model is chosen to solve the chemical kinetics between fuel and oxigen. Radiation heat transfer was calculated...
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Operational problems of large power diesel engines combusting biofuels, considered togetherwith assessment of their operation
PublikacjaWithin this article the issue of large power self ignition engines fed with biofuels has been undertaken. The analysis focused mainly on operation problems. There has been noticed some advantages and difficulties associated with the biofuel application to self ignition engines. The research problem has been characterised and the research purposes have been proposed enabling the most profitable formation of energetic features of...
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Degradation of xylose using a microbial fuel cell
PublikacjaIt is generally known, that many kind of microorganisms are capable of using carbohydrates as a source of carbon and energy in an environment. The biodegradation process of monosaccharides from pentoses (in this case- racemic mixture of D - and L – xylose) is an immense opportunity for an entire reduction of biological contamination to neutral compounds through MFC. The process is occurred in a single-chamber MFC, which is contained...
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Analytical chemistry in technical approaches: immobilization of biosorbent waste containing heavy metals in cemented materials
PublikacjaAn ecologically safe and economically justified method of stabilization of the used biosorbents was developed. Sorbent contaminated with heavy metals has been successfully solidified/stabilized using a hydraulic binder. The test results indicated that up to 1% of the biosorbent residue used could be added without compromising the compressive strength of the mortar. The compressive strength of the modified mortars did not change...
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Analysis of magnetic field inside thin-layer ferromagnetic objects
PublikacjaResults of the numerical analysis of the magnetic field inside an infinitely long, thin-layer ferromagnetic pipe with and without a barrier were presented in this paper. Two wires with current symmetrically placed on two sides of the pipe are the sources of magnetic field. Numerical calculations for the quasi-steady state for chosen frequency band were carried out in the Flux 2D.
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Effect of operating conditions on N 2 O production in an anammox sequencing batch reactor containing granular sludge
PublikacjaNitrous oxide (N2O) is one of the gases with the greatest impact in the atmosphere due to its persistence and significant contribution to the greenhouse effect. This study provides an insight into the dynamics of N2O production in wastewater nitrogen removal systems. A 10 L sequencing batch reactor containing enriched anammox biomass was subjected to different operational conditions, i.e., temperature, feed time, NO2 /NH4 þ ratio...
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X-RAY DIFFRACTION STUDY OF BISMUTH LAYER-STRUCTURED MULTIFERROIC CERAMICS
PublikacjaGoal of the present research was to apply a solid state reaction route to fabricate bismuth layer-structured multiferroic ceramics described with the formula Bi5FeTi3O15 and reveal the influence of processing conditions on its crystal structure and phase composition. Simple oxide powders Bi2O3, TiO2 and Fe2O3 were used to fabricate Aurivillius-type bismuth layer-structured ferroelectrics. Pressureless sintering in ambient air was...
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The effect of morphology and crystalline structure of Mo/MoO3 layers on photocatalytic degradation of water organic pollutants
PublikacjaMolybdenum oxide layers were formed by anodization of the Mo metallic foil in a water/ethylene glycol-based electrolyte containing fluoride ions. The as-prepared, amorphous samples were annealed in air at different temperatures in a range from 100 �C to 700 �C. The crystal phase and morphology of anodized and annealed MoO3 layers were investigated using X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. The...
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Wykorzystanie fourierowskiej spektroskopii w podczerwieni do badania stężenia gazów wylotowych z tlenkowego ogniwa paliwowego zasilanego biogazem
PublikacjaW dzisiejszych czasach bardzo ważne jest pozyskiwanie energii ze źródeł odnawialnych i bezpiecznych dla środowiska. Jedną z obiecujących technologii są tlenkowe ogniwa paliwowe (ang. Solid Oxide Fuel Cell, SOFC). Stanowią one bezpieczną i ekologiczną alternatywę dla energii uzyskanej z paliw kopalnych. SOFC charakteryzuje się sprawnością energetyczną na poziomie 45-60 %, podczas gdy sprawność klasycznych elektrowni cieplnych nie...
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The low coherence Fabry-Pérot interferometer with diamond and ZnO layers
PublikacjaThe authors present a fiber-optic Fabry-Pérot interferometer built with the application of diamond and zinc oxide (ZnO) thin layers. Thin ZnO films were deposited on the tip of a standard telecommunication single-mode optical fiber (SMF- 28) while the diamond layer was grown on the plate of silicon substrate. Investigated ZnO layers were fabricated by atomic layer deposition (ALD) and the diamond films were deposited using Microwave...
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Optical monitoring of electrochemical processes with ITO-based lossy-mode resonance optical fiber sensor applied as an electrode
PublikacjaIn this work we discuss the application of optical fiber sensors based on lossy-mode resonance (LMR) phenomenon for real-time optical monitoring of electrochemical processes. The sensors were obtained by a reactive high power impulse magnetron sputtering of indium tin oxide (ITO) on a 2.5 cm-long core of polymer-clad silica fibers. The LMR effect made monitoring of changes in optical properties of both ITO and its surrounding medium...
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Analogue CMOS ASICs in Image Processing Systems
PublikacjaIn this paper a survey of analog application specific integrated circuits (ASICs) for low-level image processing, called vision chips, is presented. Due to the specific requirements, the vision chips are designed using different architectures best suited to their functions. The main types of the vision chip architectures and their properties are presented and characterized on selected examples of prototype integrated circuits (ICs)...
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Enhanced Electrochemical Performance of MnCo1.5Fe0.5O4Spinel for Oxygen Evolution Reaction through Heat Treatment
PublikacjaMnCo1.5Fe0.5O4 spinel oxide was synthesized using the sol−gel technique, followed by heat treatment at various temperatures (400, 600, 800, and 1000 °C). The prepared materials were examined as anode electrocatalysts for watersplitting systems in alkaline environments. Solid-state characterization methods, such as powder X-ray diffraction and X-ray absorption spectroscopy (XAS), were used to analyze the materials’ crystallographic...
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Glass-ceramic joining of Fe22Cr porous alloy to Crofer22APU: interfacial issues and mechanical properties
PublikacjaThis work deals with the joining of porous Fe22Cr ferritic stainless steel to a dense Crofer22APU plate by using a silica-based, Ba-containing glass-ceramic. The chemical and interfacial stability and the mechanical properties of the joints were evaluated before and after thermal ageing at 700 ◦C for 500hrs. The sintering behaviour of the glass was assessed by using heating stage microscopy (HSM) to study the influence of a porous...
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Effects of Surface Pretreatment of Titanium Substrates on Properties of Electrophoretically Deposited Biopolymer Chitosan/Eudragit E 100 Coatings
PublikacjaThe preparation of the metal surface before coating application is fundamental in determining the properties of the coatings, particularly the roughness, adhesion, and corrosion resistance. In this work, chitosan/Eudragit E 100 (chit/EE100) were fabricated by electrophoretic deposition (EPD) and both their microstructure and properties were investigated. The present research is aimed at characterizing the effects of the surface...
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Development of Microstructured Carbon Coatings by Substrate-Catalytic CVD
PublikacjaCarbon nanostructured films were synthesized by chemical vapor deposition (CVD) on H18 stainless steel (AISI 440C) sheets with an H2/CH4/N2 gas mixture at various substrate temperatures. During the synthesis, the iron and chromium oxide layer was formed between the steel and carbonaceous layer. The carbon films exhibited wall-like and spherical morphologies and structures, as characterized by scanning electron microscopy and Raman...
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Novel two-step synthesis method of thin film heterojunction of BiOBr/Bi2WO6 with improved visible-light-driven photocatalytic activity
PublikacjaA novel two-step ionic liquid assisted procedure was applied for a controllable synthesis of BiOBr/Bi2WO6 heterojunction thin films. The preparation route involved an anodic oxidation of tungsten foil and hydrothermal transformation of as-anodized oxide in the presence of bismuth precursor and ionic liquid, N-butylpyridinium bromide [BPy][Br]. The BiOBr plates with irregular shapes adhered to the surface of flower-like Bi2WO6 and...
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Metal (Mo, W, Ti) Carbide Catalysts: Synthesis and Application as Alternative Catalysts for Dry Reforming of Hydrocarbons—A Review
PublikacjaDry reforming of hydrocarbons (DRH) is a pro-environmental method for syngas production. It owes its pro-environmental character to the use of carbon dioxide, which is one of the main greenhouse gases. Currently used nickel catalysts on oxide supports suffer from rapid deactivation due to sintering of active metal particles or the deposition of carbon deposits blocking the flow of gases through the reaction tube. In this view,...
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Modification of structured bio‑carbon derived from spongin-based scaffolds with nickel compounds to produce a functional catalyst for reduction and oxidation reactions: Potential for use in environmental protection
PublikacjaThree different 3D fibrous-like NiO/Ni(OH)2/Ni‑carbonized spongin-based materials were prepared via a simple sorption–reduction method. Depending on the support used, the catalysts were composed of carbon, nickel oxide, nickel hydroxide and zero-valent nickel, with the surface content of the nickel-containing phase in the range 15.2–26.0 wt%. Catalytic studies showed promising activity in the oxidation of phenolic compounds in water...
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Hydrogen Production Mechanism in Low-Temperature Methanol Decomposition Catalyzed by Ni3Sn4 Intermetallic Compound: A Combined Operando and Density Functional Theory Investigation
PublikacjaHydrogen production from methanol decomposition to syngas (H2 + CO) is a promising alternative route for clean energy transition. One major challenge is related to the quest for stable, cost-effective, and selective catalysts operating below 400 °C. We illustrate an investigation of the surface reactivity of a Ni3Sn4 catalyst working at 250 °C, by combining density functional theory, operando X-ray absorption spectroscopy, and high-resolution...