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Wyniki wyszukiwania dla: multicomponent oxides
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Study of Phase and Chemical Composition of Bi1-xNdxFeO3 Powders Derived by Pressureless Sintering
PublikacjaIn the present paper studies on Bi1xNdxFeO3 for x =0.1-0.4 are reported. The mixed oxide method followed with pressureless sintering was employed for ceramics fabrication. Thermal behavior of stoichiometric mixtures of simple oxide powders, viz. Bi2O3, Nd2O3 and Fe2O3 was studied by simultaneous thermal analysis. It was found that with an increase in neodymium content the weight loss increased from 0.75% to 3.16% for x =0.1 and...
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Anisotropic optical properties of few-layer black phosphorus coatings: from fundamental insights to opto-electrochemical sensor design
PublikacjaFew-layer black phosphorus (FLBP) is characterised by a tuneable bandgap, high carrier mobility and anisotropic optical properties. It therefore has the potential to find applications in electronics and photonics. FLBP oxidizes upon exposure to air, limiting its utility in devices and components. To address this issue, the thesis introduces methods and tools developed for studying FLBP's optical parameters, with a particular emphasis...
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Electro-chemo-mechanical properties in nanostructured Ca-doped ceria (CDC) by field assisted sintering
PublikacjaRecent investigations have shown that highly oxygen defective cerium oxides generate non-classical electrostriction that is superior to lead-based ferroelectrics. In this work, we report the effect of field-assisted spark plasma sintering (SPS) on electro-chemo-mechanical properties of calcium doped ceria (CDC). Nanometric powders of Ca.10 nm are rapidly consolidated to form polycrystalline nanostructures with a high degree of...
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Utilization of molten salt synthesis route in ceramics production
PublikacjaThe molten salt synthesis method is widely used to prepare ceramic powders for various applications e.g. piezoelectric devices or electrolytes for solid oxide fuel cells. The usage of this method workdwide is quite common especially in piezoelectric powder synthesis. In this work several application of the method is presented and the advantages of this route are numbered.
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Activation of N2O and SO2 by the P–B Bond System. Reversible Binding of SO2 by the P–O–B Geminal Frustrated Lewis Pair
PublikacjaHerein, we present the first transformation of borylphosphine into borylphosphinite using nitrous oxide. Borylphosphine reacts with N2O via insertion of a single oxygen atom into the P−B bond and formation of a P−O−B bond system. Borylphosphine and borylphosphinite capture SO2 and activate it in an irreversible and reversible manner, respectively.
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Synthesis and Spectroscopic Characterization of Selected Phenothiazines and Phenazines Rationalized Based on DFT Calculation
PublikacjaTwo unique structures were isolated from the phosphorylation reaction of 10H-phenothiazine.The 5,5-dimethyl-2-(10H-phenothiazin-10-yl)-1,3,2-dioxaphosphinane 2-oxide (2a) illustrates theproduct of N-phosphorylation of phenothiazine. Moreover, a potential product of 2a instability,a thiophosphoric acid 2b, was successfully isolated and structurally characterized. Molecule 2a,similarly to sulfoxide derivative...
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Laser patterned platform with PEDOT–graphene composite film for NO2 sensing
PublikacjaThis work presents a simple and fully electrochemical route used for fabricating of a NO2 gas sensor made of reduced-graphene-oxide-poly(3,4-ethylenedioxythiophene) composite film. The sensing platform was fabricated from alumina substrate and equipped with gold interdigitated electrodes and built-in heater.The temperature distribution on the surface of interdigitated electrodes was investigated by a thermalimaging camera and compared...
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Influence of Gd deposition on the oxidation behavior and electrical properties of a layered system consisting of Crofer 22 APU and MnCo2O4 spinel
PublikacjaIn the study, the surface of the Crofer 22APU ferritic steel was modified with gadolinium oxide nanoparticles and a protective-conducting layer consisting of the MnCo2O4 spinel. This system was studied in the context of application in IT-SOFC interconnects. Four types of samples were studied: unmodified steel, steel coated with a manganese-cobalt spinel layer, steel modified with gadolinium oxide nanoparticles, and a system consisting...
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The influence of photointercalaction and photochromism effects on the photocatalytic properties of electrochemically obtained maze-like MoO3 microstructures
PublikacjaMolybdenum oxide (α-MoO3) thin films with oriented crystalline facets were synthesised by anodization of Mo foils. The obtained samples were exposed to UV–Vis illumination in aqueous electrolytes providing different cations. The morphology and structure of modified samples were investigated. The effect of photointercalated alkali metal cations (Li+, Na+, K+) on optical and structural properties was studied using UV–vis and Raman...
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Hydrogen degradation of pre-oxidized zirconium alloys
PublikacjaThe presence of the oxide layers on Zr alloys may retard or enhance the hydrogen entry and material degradation, depending on the layer features. This research has been aimed to determine the effects of pre-oxidation of the Zircaloy-2 alloy at a different temperature on hydrogen degradation. The specimens were oxidised in laboratory air at 350°C, 700°C, and 900°C. After, some samples were tensed at 10-5 strain rate and simultaneously...
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Propagation in the Open Cylindrical Guide of Arbitrary Cross Section With the Use of Field Matching Method
PublikacjaA simple solution to propagation problem in open waveguides and dielectric fibers of arbitrary convex cross section is presented. The idea of the analysis is based on the direct field matching technique involving the usage of the field projection at the boundary on a fixed set of orthogonal basis functions. A complex root tracing algorithm is utilized to find the propagation coefficients of the investigated guides. Different convex...
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Instytucjonalny kontekst intencji rozwojowych przedsiębiorstw na Pomorzu
PublikacjaLiteratura dotycząca wzrostu małych firm podkreśla wagę kontekstu instytucjonalnego w tworzeniu warunków ich wzrostu. Mówiąc o instytucjach należy odróżniać zarówno aspekt obiektywny jak i subiektywny. Artykuł porusza oba aspekty: jakość instytucji jak i ich postrzeganie przez przedsiębiorców. Ten drugi aspekt został opisany w oparciu o wyniki badań Pomorskiego Obserwatorium Gospodarczego. W konkluzji zawarto wniosek iż postrzeganie...
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Tuning of the plasmon resonance location in Au nanostructures coated with a ultrathin film of Al2O3 – Optical measurements and FDTD simulations
PublikacjaThe Au nanostructures have been coated with an ultra-thin films of amorphous aluminium oxide. Optical absorption spectra show the influence of the thickness of Al2O3 on plasmon resonance wavelength. The observed red-shift of the resonance location with the increase of the thickness of the Al2O3 film, can be explained by the change in the dielectric function of this film. It allows control of the optical spectra of the coated particles....
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Mn-Co spinel coatings on Crofer 22 APU by electrophoretic deposition: Up scaling, performance in SOFC stack at 850 °C and compositional modifications
PublikacjaCeramic coatings for metallic interconnects play a key role in limiting corrosion and chromium evaporation in solid oxide cells. This study presents the upscaling of the electrophoretic deposition (EPD) technique to process Mn-Co spinels on real-dimension Crofer 22 APU interconnects and the test in a SOFC stack. Area specific resistance of long-term test conducted for 5000 h at 850 °C demonstrated that two-steps sintering has a...
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Effect of double thermal and electrochemical oxidation on titanium alloys for medical applications
PublikacjaThe research focuses on the development and characterization of innovative thin hybrid oxide coatings obtained in subsequent processes of thermal (TO) and electrochemical (EO) oxidation. Four different surface modifications were investigated and the microstructure was determined, the mechanical, chemical and biological properties of the Ti-13Nb-13Zr alloy were assessed using scanning electron microscopy, X-ray dispersion analysis,...
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Poloxamer: A versatile tri-block copolymer for biomedical applications
PublikacjaPoloxamers, also called Pluronic, belong to a unique class of synthetic tri-block copolymers containing central hydrophobic chains of poly(propylene oxide) sandwiched between two hydrophilic chains of poly(ethylene oxide). Some chemical characteristics of poloxamers such as temperature-dependent self-assembly and thermo-reversible behavior along with biocompatibility and physiochemical properties make poloxamer-based biomaterials...
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The CFD analysis of influence the start of fuel injection (SOI) on combustion parameters and exhaust gas composition of the marine 4-stroke engine
PublikacjaThe paper presents a theoretical analysis of the impact of injection timing on the parameters of the combustion process and the composition of exhaust gas from a 4-stroke engine designed to shipbuilding. The analysis was carried out based on a three-dimensional multi-zone model of the combustion process. This model has been prepared on the basis of properties of the research facility. The input data to the model were obtained through...
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Problem of Clogging in Drainage Systems in the Examples of the Zur and Podgaje Dams
PublikacjaDrainage plays an extremely important role in hydraulic structures, such as earth dams. Observations of drainage in hydraulic structures under various soil conditions indicate that the phenomenon of clogging can lead to a radical reduction in the efficiency of drainage, making it non-functional within a few years after construction. This article describes the problems of drainage clogging by iron oxide in the examples of the Zur...
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Influence of plasmon resonance on the luminescence of titanium dioxide thin films doped with rare earth ions
PublikacjaIn this work the study of the optical properties of europium doped titanium dioxide thin films (TiO2:Eu) enhanced by gold plasmonic nanostructures are presented. Plasmonic platforms were manufactured by thermal annealing of thin film of Au, deposited on a Corning glass substrate. As a result of thermal treatment, gold spherical nanostructures with average dimensions of 50 nm were obtained. Luminescent TiO2:Eu film was deposited...
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Katalizatory wykorzystywane w syntezie biodiesla
PublikacjaRising prices of electricity, conventional fuels and heating require decisive steps in the further development of technologies based on renewable energy sources. These include geothermal-; hydrothermal-; aerothermal-; and solar energy. Due to the fact that the petrochemical industry is one of the fastest growing branches of the economy, we would like to expand on the topic related to biofuels. Biodiesel is an alternative fuel similar...
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Evaluation of the influence of the opening pressure of a marine Diesel engine injector on the results of numerical simulation of the working cycle and their comparison with the results of the laboratory experiment
PublikacjaThe article presents the results of a numerical simulation of the working process carried out in a diesel engine. In the applied utility program DIESEL-RK, the laboratory engine Farymann Diesel type D10 was implemented. A selected inoperability of its functional fuel supply system - reduced opening pressure of the injector pinj - was introduced. The values of adequate diagnostic parameters were determined: working gas temperature...
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Antimony substituted lanthanum orthoniobate proton conductor – structure and electronic properties.
PublikacjaX‐ray and neutron diffraction have been utilized to analyze the crystalline and electronic structure of lanthanum orthoniobate substituted by antimony. Using X‐ray absorption spectroscopy and photoelectron spectroscopy, changes in the electronic structure of the material upon substitution have been analyzed. The structural transition temperature between fergusonite and scheelite phases for 30 mol% antimony substitution was found...
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Stabilization of the pyrochlore phase of Mn2Sb2O7 by double substitution
PublikacjaPolycrystalline samples of (Ce4+Mn2+3)(Ga3+Sb5+3)O14 were synthesized by a high-temperature solid-state reaction. In contrast with the parent Mn2Sb2O7 compound that adopts a rhombohedral or monoclinic structure at T > 600 °C, the pyrochlore structure of CeMn3GaSb3O14 is retained up to at least T = 1070°C. High-resolution synchrotron x-ray diffraction measurements show no sign of a superstructure or distortion from cubic symmetry...
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Tailoring the Size and Shape—New Path for Ammonium Metavanadate Synthesis
PublikacjaAmmonium metavanadate, NH4VO3, plays an important role in the preparation of vanadium oxides and other ammonium compounds, such as NH4V3O8, (NH4)2V3O8, and NH4V4O10, which were found to possess interesting electrochemical properties. In this work, a new route for the synthesis of NH4VO3 is proposed by mixing an organic ammonium salt and V2O5 in a suitable solvent. The one-step procedure is carried out at room temperature. Additionally,...
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Progress in targeting tumor cells by using drug-magnetic nanoparticles conjugate.
PublikacjaTo limit the cytotoxicity of anticancer drugs against healthy cells, an appropriate carrier should be synthesized to deliver the drug to the tumor tissue only. A good solution is to anchor a magnetic nanoparticle to the molecule of the drug and to use a properly directed external magnetic field. We have shown that the improved by us synthesis of the conjugate of doxorubicin with iron-oxide magnetic nanoparticles allows a substantial...
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Thermal Instability of Gold Thin Films
PublikacjaThe disintegration of a continuous metallic thin film leads to the formation of isolated islands, which can be used for the preparation of plasmonic structures. The transformation mechanism is driven by a thermally accelerated diffusion that leads to the minimalization of surface free energy in the system. In this paper, we report the results of our study on the disintegration of gold thin film and the formation of nanoislands...
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Novel Structures and Applications of Graphene-Based Semiconductor Photocatalysts: Faceted Particles, Photonic Crystals, Antimicrobial and Magnetic Properties
PublikacjaGraphene, graphene oxide, reduced graphene oxide and their composites with various compounds/materials have high potential for substantial impact as cheap photocatalysts, which is essential to meet the demands of global activity, offering the advantage of utilizing “green” solar energy. Accordingly, graphene-based materials might help to reduce reliance on fossil fuel supplies and facile remediation routes to achieve clean environment...
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TiO2-based magnetic nanocomposites with core-shell structure
PublikacjaThe main aim of the doctoral dissertation was preparation and characterization of photocatalysts, with particular emphasis on modified titanium (IV) oxide photocatalysts, which can be applied for the degradation of organic pollutants not susceptible to biodegradation. A particularly important aspect of the work was the development of preparation method of nanocomposites with the magnetic core-shell and photocatalyst shell (TiO2)...
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Ways of shaping love for God and people and historical memory during the Year of St. Stanislaus Kostka
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Competences of academic tutors – research among participants of the project “Masters of Didactics”
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Immunosuppressive properties of amino acid and peptide derivatives of mycophenolic acid
PublikacjaMycophenolic acid (MPA) was coupled with amino acids and biologically active peptides including derivatives of tuftsin to modify its immunosuppressive properties. Both amino acid unit in the case of simple MPA amides and modifications within peptide moiety of MPA - tuftsin conjugates influenced the observed activity. Antiproliferative potential of the obtained conjugates was investigated in vitro and MPA amides with threonine methyl...
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Fault detection in the marine engine using a support vector data description method
PublikacjaFast detection and correct diagnosis of any engine condition changes are essential elements of safety andenvironmental protection. Many diagnostic algorithms significantly improve the detection of malfunctions.Studies on diagnostic methods are rarely reported and even less implemented in the marine engine industry.To fill this gap, this paper presents the Support Vector Data Description (SVDD) method as applied to thefault detection...
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Is the Solid Electrolyte Interphase an Extra-Charge Reservoir in Li-Ion Batteries?
PublikacjaAdvanced metal oxide electrodes in Li-ion batteries usually show reversible capacities exceeding the theoretically expected ones. Despite many studies and tentative interpretations, the origin of this extra-capacity is not assessed yet. Lithium storage can be increased through different chemical processes developing in the electrodes during charging cycles. The solid electrolyte interface (SEI), formed already during the first...
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Endothelial Dysfunction Driven by Hypoxia—The Influence of Oxygen Deficiency on NO Bioavailability
PublikacjaCardiovascular diseases (CVDs) are the leading cause of death worldwide. The initial stage of CVDs is characterized by endothelial dysfunction, defined as the limited bioavailability of nitric oxide (NO). Thus, any factors that interfere with the synthesis or metabolism of NO in endothelial cells are involved in CVD pathogenesis. It is well established that hypoxia is both the triggering factor as well as the accompanying factor...
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Morphology changes in Fe-Cr porous alloys upon high-temperature oxidation quantified by X-ray tomographic microscopy
PublikacjaThe effect of high-temperature oxidation at 850 C (10 h, 30 h, 100 h) and 900 C (10 h) on porous (30 % porosity) ferritic stainless steel (Fe22Cr) has been investigated using synchrotron tomographic microscopy, which allowed for visualisation, separation and quantitative analysis of the metallic core, closed pores, open pores and oxide scale phase. The same regions within the samples were investigated before and after oxidation...
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Transparent thin films of Cu-TiO2 with visible light photocatalytic acitivity
PublikacjaThin films of Cu–TiO2 with a high level of transparency were prepared by a dip-coating procedure on the glass surface. CuCl2 was used as a copper precursor added during sol – gel synthesis of TiO2. The extension of optical absorption into the visible region of as-prepared thin films was indicated by UV/Vis spectroscopy. Only the anatase phase was detected by X-ray di ffraction analysis (XRD). The presence of copper in the structure...
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Protonic Ceramic Fuel Cells as novel electrochemical devices
PublikacjaProton ceramic conductors are novel materials which are interesting from the application point of view. For example, Protonic Ceramic Fuel Cells (PCFCs) is a type of a solid oxide fuel cell, which uses proton ceramic conductors as an electrolyte. Scientists are looking for the most efficient materials for these devices. In recent years main focus has been put on the search for new proton and mixed proton-electron conductors which...
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Donor-substituted SrTi1+xO3−δ anodes for SOFC
PublikacjaNonstoichiometric Nb-substituted SrTiO3 compounds were investigated in order to discuss the influence of nonstoichiometry at the sample properties in the light of recent results reported in the literature. Structural and electrical properties of samples were characterized. Investigated compounds were also applied as anodes for Solid Oxide Fuel Cells and their reactivity with YSZ electrolyte was examined. The defect chemistry explaining...
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Improvement of microstructure and mechanical properties of high dense sic ceramics manufactured by high-speed hot pressing
PublikacjaNon-oxide ceramics possess high physical-mechanical properties, corrosion and radiation resistance, which can be used as a protective materials for radioactive wastes disposal. The aim of the present study was the manufacturing of high density SiC ceramics with advanced physical and mechanical parameters. The high performance on the properties of produced ceramics was determined by the dense and monolithic structure. The densified...
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Determining the leakage current resistive component by the orthogonal vector method
PublikacjaThe measurement of the metal – oxide surge arresters (MOSA) leakage current and the analysis of its components is a key diagnostic criterion according to technical standards. During on site MOSA condition assessment, the easy way is based on the measurement only leakage current, without the inconvenient live working measurements of supply voltage. Orthogonal vectors method of determination the resistive leakage current is presented....
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Fabrication and structural properties of Y and Fe co-doped SrTiO3 nanoceramics for SOFC
PublikacjaYttria and iron co-doped strontium titanate perovskites, (Y0,07Sr0,93Ti1-xFexO3-δx=0,1; 0,2) samples were fabricated by two methods: solid-state synthesis (SS) and the Pechinisol-gel modified method. The morphology of samples were measured by SEM and X-raydiffraction. Results were compared and discussed. The strong relationship between fabricationprocedure and microstructure has been proven. It was also observed, that the nanoceramicsobtained...
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The Synergistic Microbiological Effects of Industrial Produced Packaging Polyethylene Films Incorporated with Zinc Nanoparticles
PublikacjaZinc compounds in polyolefin films regulate the transmission of UV-VIS radiation, affect mechanical properties and antimicrobial activity. According to hypothesis, the use of zinc- containing masterbatches in polyethylene films (PE) with different chemical nature—hydrophilic zinc oxide (ZO) and hydrophobic zinc stearate (ZS)—can cause a synergistic effect, especially due to their antimicrobial properties. PE films obtained on an...
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Structural and optical investigations of sol-gel derived lithium titanate thin films
Publikacjain this paper structural and optical studies of lithium titanate (lto) thin films are presented. nanocrystalline thin films with 800 nm thickness were prepared by sol-gel method. to examine the influence of the annealing time on as-prepared films crystallization, the coatings were heated at 550 °c for 10, 20 and 80 h. structure of manufactured thin films was investigated using x-ray diffraction (xrd). the most visible lithium titanate...
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Mechanism of hopping conduction in Be–Fe–Al–Te–O semiconducting glasses and glass–ceramics
PublikacjaElectrical properties of beryllium-alumino-tellurite glasses and glass–ceramics doped with iron ions were studied using impedance spectroscopy. The conductivity was measured over a wide frequency range from 10 mHz to 1 MHz and the temperature range from 213 to 473 K. The D.C. conductivity values showed a correlation with the Fe-ion concentration and ratio of iron ions on different valence states in the samples. On the basis of...
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Effect of isovalent substitution on microstructure and phase transition of LaNb1−xMxO4 (M=Sb, V or Ta; x=0.05–0.3)
PublikacjaLaNb1−xMxO4 oxides with pentavalent elements of different ionic sizes (M=Sb, Ta and V, x=0.05–0.3) were synthesized by the solid state reaction method. Special interest was devoted to the antimony substituted lanthanum niobate which is a new material in this group. Rietveld analysis of the X-ray diffraction patterns was used to determine the influence of the material composition on unit cell parameters. On the basis of dilatometric...
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INFLUENCE OF BISMUTH CONTENT ON COMPLEX IMMITTANCE CHARACTERISTICS OF PRESSURELESS SINTERED BiNbO4 CERAMICS
PublikacjaGoal of the present research was to study immittance properties of BiNbO4 ceramics fabricated by the solid state reaction route followed by pressureless sintering. Four sets of samples were examined, namely the one fabricated from the stoichiometric mixture of oxides, viz. Bi2O3 and Nb2O5 as well as the ones with an excess of 3%, 5% and 10% by mole of Bi2O3. The immittance properties were studied by impedance spectroscopy. Measurements...
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Enhanced photocatalytic activity of transparent carbon nanowall/TiO2 heterostructures
PublikacjaThe synthesis of novel tunable carbon-based nanostructure represented a pivotal point to enhance the efficiency of existing photocatalysts and to extend their applicability to a wider number of sustainable processes. In this letter, we describe a transparent photocatalytic heterostructure by growing boron-doped carbon nanowalls (B-CNWs) on quartz, followed by a simple TiO2 sol-gel deposition. The effect on the thickness and boron-doping...
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Badania stabilności chemicznej kompozytowego elektrolitu 3-YSZ-Al2O3 w stosunku do materiałów elektrodowych do zastosowania w średniotemperaturowych ogniwach paliwowych
PublikacjaJednym z podstawowych wymogów stawianych mate- riałom na elektrolity do średniotemperaturowych ogniw paliwowych IT-SOFC (ang. intermediate-temperature solid oxide fuel cells) jest ich kompatybilność chemiczna z elektrodami w temperaturach zarówno eksploatacji, jak i wytwarzania ogniw. W celu sprawdzenia, czy badany w pracy kompozytowy elektrolit o osnowie z częściowo stabilizowanego ditlenku cyrkonu i z wtrąceniami tlenku glinu...
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Warstwy funkcjonalne tlenkowych ogniw paliwowych
PublikacjaIn this paper, results describing current research on solid oxide fuel cells conducted at Gdańsk University of Technology, Faculty of Electronics, Telecommunications and Informatics are presented. The results are related to three kinds of functional layers: a thin cathode layer between the porous cathode layer and the electrolyte to improve the cathode performance, a buffer layer between the electrolyte and the cathode to slow...
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Application of multisine nanoscale impedance microscopy to heterogeneous alloy surface investigations
PublikacjaIn the recent years atomic force microscopy is recognized as valuable tool for investigation of surficial features of construction materials. It concerns, among other things, studies of changes caused by such phenomena as galvanic corrosion, passivation associated with the growth of oxide layers, or sensitization of austenitic steels with the formation of carbide phases. In addition, atomic forcemicroscopy allows easy coupling...