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Wyniki wyszukiwania dla: POLYMER DERIVED CERAMICS
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An experimental study on polymer mass
PublikacjaA new method of repairing damaged structures by filling the cracks with specially prepared polymer mass has been recently proposed. The technique is mainly dedicated to historical objects where minimum intervention is permitted. The flexible joint bonds the disrupted elements and ensures further safe exploitation of a damaged structure. The aim of the present paper is to show the results of an experimental study on polymer mass...
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Reactive extrusion of bio-based polymer blends and composites – Current trends and future developments
PublikacjaReactive extrusion is a cost-effective and environmentally-friendly method to produce new materials with enhanced performance properties. At present, reactive extrusion allows in-situ polymerization, modification/functionalization of polymers or chemical bonding of two (or more) immiscible phases, which can be carried out on commonly used extrusion lines. Although reactive extrusion has been known for many years, its application...
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Highly antifouling polymer-nanoparticle-nanoparticle/polymer hybrid membranes
PublikacjaWe introduce highly antifouling Polymer-Nanoparticle-Nanoparticle/Polymer (PNNP) hybrid membranes as multi-functional materials for versatile purification of wastewater. Nitrogen-rich polyethylenimine (PEI)-functionalized halloysite nanotube (HNT-SiO2-PEI) nanoparticles were developed and embedded in polyvinyl chloride (PVC) membranes for protein and dye filtration. Bulk and surface characteristics of the resulting HNT-SiO2-PEI...
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Planetary roller extruders in the sustainable development of polymer blends and composites – Past, present and future
PublikacjaScrew extruders as continuous flow reactors allow the synthesis of new polymers, preparation of polymer blends and composites, and modification or functionalization of commercially available polymers. Literature data shows that the twin screw extrusion is the most popular solution used for this purpose. In contrast, the number of scientific papers on alternative methods, such as multi-screw extruders, is somewhat limited. This...
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Interface analysis of compatibilized polymer blends
PublikacjaThis chapter seeks to address the interface location in the compatibilized polymer blends and paves the way for quantitative analysis of interface in terms of interfacial tension and interfacial adhesion to provide support for understanding the relationship between morphology and ultimate properties in the compatibilized polymer blends through the lens of interface. Since understanding and analysis of interfacial phenomena in the...
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Fabrication and Structural Properties of LaNb 1‐x As x O 4 Ceramics
PublikacjaLanthanum niobate substituted with arsenic was synthesized by three methods: solid state reaction from binary oxides and two different methods combining co-precipitation and solidstate reaction. In the first of the combined methods LaNb1- xAsxO4 was synthesized from LaAsO4, obtained from coprecipitation method, and lanthanum and niobium oxides. In the second LaNbO4 was first synthesized from binary oxides and then mixed with LaAsO4...
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Effects of Ca2+, Mg2+, Na+, and K+ substitutions on the microstructure and electrical properties of GdCoO3 ceramics
PublikacjaGdCoO3-δ, Gd0.975Na0.025CoO3-δ, Gd0.98K0.02CoO3-δ, Gd0.98Ca0.02CoO3-δ, and GdCo0.99Mg0.01O3-δ ceramics were prepared via a solid-state reaction route. Among the dopants studied, substitution with Ca2+ slightly enhanced the densfication of GdCoO3 ceramics. All the lattice parameters of the doped ceramics were larger than those of pure GdCoO3-δ ceramic (a = 5.223 Å, b = 5.389 Å and c = 7.451 Å), and their cell volumes increased by...
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Mg2+ Doping Effects on the Structural and Dielectric Properties of CaCu3Ti4O12 Ceramics Obtained by Mechanochemical Synthesis
PublikacjaIn this study, ceramic CaCu3Ti4O12 (CCTO) and CaCu3−xMgxTi4O12 solid solutions in which 0.1 ≤ x ≤ 0.5 were prepared by the mechanochemical method, realized by a high‐energy ball milling technique. The effects of the Mg2+ ion concentration and sintering time on the dielectric response in the prepared ceramics were investigated and discussed. It was demonstrated that, by the use of a sufficiently high energy of mechanochemical treatment,...
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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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Experimental examination of an elastomeric polymer
PublikacjaA new method of repairing damaged structures by filling the cracks with a specially prepared elastomeric polymer mass has been recently proposed. This new and innovative technique, known as the Flexible Joint Method (FJM), is mainly dedicated to masonries and historical objects, where minimum intervention is permitted. The flexible joint bonds the disrupted elements and ensures further safe exploitation of a damaged structure....
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Low temperature broad band dielectric spectroscopy of multiferroic Bi6Fe2Ti3O18 ceramics
PublikacjaIn the present research the tool of broadband dielectric spectroscopy was utilized to characterize dielectric behavior of Bi6Fe2Ti3O18 (BFTO) Aurivillius-type multiferroic ceramics. Dielectric response of BFTO ceramics was studied in the frequency domain (Δν=0.1Hz – 10MHz) within the temperature range ΔT=-100°C – 200°C. The Kramers-Kronig data validation test was employed to validate the impedance data measurements and it was found...
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Inhibition of Polymer Photodegradation by Incorporation of Coffee Silverskin
PublikacjaOver the last years, the trend associated with the incorporation of materials from renewable resources into polymer technology is getting significantly more vital. Researchers are trying to transfer the properties of natural raw materials into the polymer world. Therefore, different natural materials are more often investigated as potential additives for polymers. Such an effect is noted for the coffee industry by-products, such...
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Thermoplastic polyurethanes derived from petrochemical or renewable resources: A comprehensive review
PublikacjaThermoplastic polyurethanes (TPUs) materials are obtained by the reaction of polyol (ether-, ester-, and carbonate-based diols with average molecular weight in the range from 1,000 to 3,000 g/mol) with aliphatic or aromatic diisocyanates. Synthesized materials consist of the hard and soft segments which are separated in different level. All mechanical and thermal properties of TPUs depend on the chemical structure of used monomers,...
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Flame-Retardant Polymer Materials Developed by Reactive Extrusion: Present Status and Future Perspectives
PublikacjaThe development of flame retardant polymer materials has two roots, one in materials design, and the other in materials processing. Over recent decades, different types and classes of flame retardant polymer materials have been commercialized to meet safety requirements in the construction, automotive, and coatings industries. In the vast majority of cases, the design and fabrication of new materials presenting low fire hazards...
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STRUCTURE AND MAGNETIC PROPERTIES OF Bi5Ti3FeO15 CERAMICS PREPARED BY SINTERING, MECHANICAL ACTIVATION AND EDAMM PROCESS. A COMPARATIVE STUDY
PublikacjaThree different methods were used to obtain Bi5Ti3FeO15 ceramics, i.e. solid-state sintering, mechanical activation (MA) with subsequent thermal treatment, and electrical discharge assisted mechanical milling (EDAMM). The structure and magnetic properties of produced Bi5Ti3FeO15 samples were characterized using X-ray diffraction and Mössbauer spectroscopy. The purest Bi5Ti3FeO15 ceramics was obtained by standard solid-state sintering...
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The research of glass-ceramics implants used for bone pitches to examine bacteria adhesion occuring in human body
PublikacjaThe paper deals with the research concerning the bacteria adhesion on bioactive glass - ceramics materials
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Development of a Peptide Derived from Platelet-Derived Growth Factor (PDGF-BB) into a Potential Drug Candidate for the Treatment of Wounds
PublikacjaObjective: This study evaluated the use of novel peptides derived from platelet-derived growth factor (PDGF-BB) as potential wound healing stimulants. One of the compounds (named PDGF2) was subjected for further research after cytotoxicity and proliferation assays on human skin cells. Further investigation included evaluation of: migration and chemotaxis of skin cells, immunological and allergic safety, the transcriptional analyses...
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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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High-conducting Bi4V2-xFexO11-δ ceramics containing Fe2O3 nanocrystals: Structure and properties
PublikacjaThe topography, structure, thermal, magnetic, and electrical properties of Bi4V2-xFexO11-δ ceramics substituted with x = 0.5 and 0.7 Fe were studied. The microscope analysis showed the presence of iron-rich nanocrystals formed on the Bi-Fe-V-O grains. The X-ray diffraction studies confirmed that grains are built mostly of tetragonal Bi4V1.5Fe0.5O10.5 phase. Thermal properties analysis showed an order-disorder type γ ↔ γʹ phase...
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Evaluating the impact of ZnO doping on electrical and thermal properties of calcium-aluminosilicate oxynitride glass-ceramics
PublikacjaThis study aimed to investigate the impact of ZnO content on the structure, thermal, and electrical properties of oxynitride glass-ceramic(s) within the Ca–Al–Si–O–N (CASON) system. The base glass had the composition of Ca7Al14Si17O52N7, with ZnO additions ranging from 3 to 15 % by weight. A pristine Ca7Al14Si17O52N7 glass was successfully prepared by melt-quenching technique followed by converted into glass-ceramic by incorporating various...
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HYDRODYNAMIC THRUST BEARINGS WITH POLYMER LINING
PublikacjaPolymeric linings of sliding surfaces of the hydrodynamic bearings have been used successfully for over 50 years. Despite of their long history of operation and research, they have not become wide spread in industrial applications. This fact may be surprising, considering th e conclusions that have been published concerning bearing operation and design. This paper summarizes the current...
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SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF NIOBIUM-DOPED HYDROXYAPATITE CERAMICS
PublikacjaHydroxyapatite (HAp) ceramic materials are considered as one of the most promising implant materials in bone surgery and in dentistry. They exhibit unique biocompatibility, bioactivity, and osteoconductivity, which are the most desirable biomaterial features. However, HAp itself is brittle, has low strength, high degree of crystallinity and low solubility at physiological pH. Doping synthetic HAp with metal ions plays an important...
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THE APPLICATION OF THE MECHANOCHEMICAL SYNTHESIS FOR THE PREPARATION OF ADVANCED CERAMICS BASED ON BARIUM TITANATE
PublikacjaIn the present study, the lead-free BaTi1-xZrxO3 (for x = 0, 0.05 and 0.15) ceramics were prepared by High-Energy Ball Milling and heat treatments. The performed X-ray, SEM and EDS measurements confirmed high purity, good quality and the expected quantitative composition of the obtained samples. The study of dielectric properties was performed by means of broadband dielectric spectroscopy at the frequency ranging from 0.1 Hz to...
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The effectiveness of polymer adhesive in reduction of vibrations of structural members
PublikacjaIn this paper, the idea of using polymer adhesive as a damping layer is proposed. An experimental study of two aluminium cantilevered beams has been conducted. One of them presents a plain cantilevered beam, while the second one considers two aluminium beams bonded with a polymer adhesive of different thickness (0,5; 1,2; 1,75; 3,1 and 5 mm). The polymer adhesive considered in the study is a specially designed flexible...
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Investigation methods of ionic conductivity measurements in polycrystalline MIEC (mixed ionic-electronic conductor) based on perovskite ceramics
PublikacjaPaper about the measurements of ionic conductivity in LSM and strontium titanate ceramics.
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Angiopoietin-like growth factor-derived peptides as biological activators of adipose-derived mesenchymal stromal cells
PublikacjaAdipose-derived mesenchymal stromal cells (AD-MSCs) are an essential issue in modern medicine. Extensive preclinical and clinical studies have shown that mesenchymal stromal/stem cells, including AD-MSCs, have specific properties (ability to differentiate into other cells, recruitment to the site of injury) of particular importance in the regenerative process. Ongoing research aims to elucidate factors supporting AD-MSC culture...
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Bacterial nanocellulose as a microbiological derived nanomaterial
PublikacjaBacterial nanocellulose (BNC) is a nanofibrilar polymer produced by strains such as Gluconacetobacter xylinus, one of the best bacterial species which given the highest efficiency in cellulose production. Bacterial cellulose is a biomaterial having unique properties such as: chemical purity, good mechanical strength, high flexibility, high absorbency, possibility of forming any shape and size and many others. Such a large number...
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Biodegradable Polymer Packaging Materials in Seawater Environment
PublikacjaIn this chapter, our interest is directed into dea/ocean/lakes biodegradable environment for polymer packaging materials from two different points of view.
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Eu3+ doped tellurite glass ceramics containing SrF2 nanocrystals: Preparation, structure and luminescence properties
PublikacjaEu3+ doped tellurite glass ceramics containing SrF2 nanocrystals were prepared using melt quenching technique and subsequent heat treatment of glass in 370 °C for different time periods. Thermal properties of glass matrix have been determined based on DSC measurements. XRD and XPS results confirmed formation of SrF2 nanocrystals in glass matrices after annealing at 370 °C. FTIR studies revealed absorption bands in the range of...
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Raman studies of ferroelectric ceramics.
PublikacjaPrzedstawiono potencjał aplikacyjny spektroskopii Ramana w diagnostyce procesu technologicznego wytwarzania cienkowarstwowych struktur perowskitowych o strukturze Ba(Ti1 xZrx)O3, posiadających możliwość strojenia przenikalności elektrycznej za pomocą pola elektrycznego. Skonfigurowano systemy pomiarowe do badania zarówno próbek objętościowych, jak i struktur cienkowarstwowych. Zidentyfikowano najistotniejsze linie w widmach ramanowskich,...
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Fractional Order Circuit Elements Derived from Electromagnetism
PublikacjaIn this paper, derivations of fractional-order (FO) circuit-element equations from electromagnetism are presented. Whilst many papers are devoted to FO modelling of electrical circuits, there are no strong foundations for such an approach. Therefore, we investigate relations between the FO electromagnetism and the FO circuit theory. Our derivations start from quasi-static (QS) approximations of Maxwell's equations in media with...
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Nonlinear and linear impedance of bismuth vanadate ceramics and its relation to structural properties
PublikacjaThe nonlinear and linear electrical properties, topography, and microstructure of bismuth-vanadate ceramics, were studied. The structurewas observed with the use of X-ray diffraction (XRD), scanning electronmicroscopy (SEM), atomic force microscopy (AFM) and confocal microscopy methods. The obtained results showed that ceramic is porous. Two phase transitionswere determinedwith the use of DSC measurements. The linear and nonlinear ac...
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A white phosphor based on oxyfluoride nano-glass-ceramics co-doped with Eu3+ and Tb3+: Energy transfer study
PublikacjaStrontium fluoride nanocrystals doped separately with Ln3+ = Eu3+ or Tb3+ ions (95SrF2·5LnF2), as well as co-doped with both the ions (95SrF2·Eu4Tb) were synthesized for comparison. Then, glass-ceramics consisting of the mono-doped or di-doped SrF2 nanocrystals incorporated into amorphous silica (90SiO2·9.5SrF2·0.5Ln or 90SiO2·9.5SrF2·0.1EuF3·0.4Tb) were prepared by sol-gel procedure. The studied materials were characterized by...
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Unveiling of polymer/fullerene blend films morphology by ellipsometrically determined optical order within polymer and fullerene phases
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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...
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The effect of Sr and Mg substitutions on structure, mechanical properties and solubility of fluorapatite ceramics for biomedical applications
PublikacjaIonic substitutions play important role in the modifications of biological apatites. Recently, attention has been focused on the co-doping effects on the functional properties of apatite-based biomaterials. In this research work, the dense samples of fluorapatites, Ca10(PO4)6F2 and Ca8MgSr(PO4)6F2, were produced after sintering at 1250 °C for 6 h in air. Structural characterization carried out with XRD, IR, Raman and SEM, confirmed...
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Recent Advances in Development of Waste-Based Polymer Materials: A Review
PublikacjaLimited petroleum sources, suitable law regulations, and higher awareness within society has caused sustainable development of manufacturing and recycling of polymer blends and composites to be gaining increasing attention. This work aims to report recent advances in the manufacturing of environmentally friendly and low-cost polymer materials based on post-production and postconsumer wastes. Sustainable development of three groups...
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Spectroscopic studies of Nb-doped tricalcium phosphate glass-ceramics prepared by sol-gel method
PublikacjaCalcium-phosphate based glasses and glass-ceramics play a crucial role in the tissue engineering development. Apart from their high biocompatibility and excellent ability to undergo varying degrees of resorbability1, they exhibit relatively high bioactivity and due to that they are commonly used as bone and dental implants. A substantial research effort is devoted to improve calcium-phosphate materials physico-chemical properties...
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Review: synthetic polymer hydrogels for biomedical applications
PublikacjaSynthetic polymer hydrogels constitute a group of biomaterials, used in numerous biomedical disciplines, and are still developing for new promising applications. The aim of this study is to review information about well known and the newest hydrogels, show the importance of water uptake and cross-linking type and classify them in accordance with their chemical structure.
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Recent advances in compatibilization strategies of wood-polymer composites by isocyanates
PublikacjaWood-polymer composites technologies are gaining more and more attention in the scientific community, positively affecting the increase in their industrial applications, for example, automotive, building, 3D printing, etc. Many research works are focused on the improvement in matrix–lignocellulosic filler interactions to produce highly filled composites with satisfying performance properties. In this field of research, using isocyanates...
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Magnetoelectric, spectroscopic, optical and elastic properties of Co-doped BaTiO3 ceramics
Publikacjahe BaTiO3 perovskite is widely used in the electronic technology due to its dielectric, piezoelectric and ferroelectric properties and is a well-known base for obtaining a promising multifunctional material. In this paper we report the extensive studies on the Co-doped BaTiO3 ceramics for the wide range cobalt content. Full structural characterization of studied samples in a 20–450 K range was provided. The results of research...
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A body position influence on ECG derived respiration
PublikacjaAn influence of a human body position on ECG derived respiration (EDR) signal is presented in the paper. Examinations were performed during deep, suspended and normal breathing for eight people in four different body positions. EDR and thoracic impedance signals were compared using correlation and standard deviation coefficients. Obtained results have shown that it is possible to monitor breath activity of people being in different...
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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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Experimental determination of basic mechanical properties of elastomeric polymer
PublikacjaThere are a lot of different methods of repairing and reinforcing damaged structures, but when it comes to historical buildings and other cultural heritage objects, it is as much about mechanical safety as the aesthetical aspects. Recently, a new and innovative method of repairing damaged structures by filling the cracks with a specially prepared polymer mass has been proposed. This new and innovative technique, known as the Flexible...
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Additive manufacturing of Proton-Conducting Ceramics by robocasting with integrated laser postprocessing
PublikacjaA hybrid system combining robocasting and NIR laser postprocessing has been designed to fabricate layers of mixed proton-electron conducting Ba0.5La0.5Co1-xFexO3-δ ceramic. The proposed manufacturing technique allows for the control of the geometry and microstructure and shortens the fabrication time to a range of a few minutes. Using 5 W laser power and a scanning speed of 500 mm⋅s− 1, sintering of a round-shaped layer with an...
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Influence of Phase Composition on Dielectric Properties of Bismuth-Based Ceramics with Scheelite-Type Structure
PublikacjaGoal of the present research was to study dielectric properties of BiNbO4 ceramics fabricated by solid state reaction route followed with pressureless sintering. The samples were fabricated from the mixture of oxides, viz. Nb2O5 and Bi2O3. Apart from stoichiometric amount an excess of 3%, 5% and 10% by mole of Bi2O3 was used. It was found that an excess amount of Bi2O3 oxide caused formation of Bi5Nb3O15 minor phase in amount of...
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Effect of crystallinity on structural, thermal, and in vitro dissolution properties of Na2O-CaO-Nb2O5/MgO-P2O5 glass-ceramics
PublikacjaThe impact of the crystallinity on structural, thermal, and in vitro dissolution properties were examined for Na2O- CaO-Nb2O5/MgO-P2O5 glasses/glass-ceramics. Glass-ceramics were synthesized via a spontaneous crystallization process. The Nb content in the materials increased with melting temperature, furthermore, the crystallinity is proportional to the Nb content. The presence of crystalline niobates and phosphates is confirmed...
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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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X-Ray Diffraction, Mössbauer Spectroscopy and Magnetoelectric Effect Studies of Multiferroic Bi5Ti3FeO15 Ceramics
PublikacjaBi5Ti3FeO15 ceramics belongs to multiferroic class of materials. In this work it was prepared by solid-state sintering method and investigated by X-ray diffraction, Mössbauer spectroscopy, and magnetoelectric effect measurements. As it was proved by X-ray diffraction studies the single-phase Bi5Ti3FeO15 compound was obtained. The Mössbauer investigations revealed paramagnetic character of the compound at room temperature as well...
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Application of polymer element in reduction of temporary steel grandstand vibrations
PublikacjaThe numerical analysis focused on reduction of vibrations of a temporary steel scaffolding grandstand has been conducted in this paper. These types of structures are regularly subjected to dynamic loads which, in conjunction with light and quite slender structural members, may induce dangerous vibrations. To increase their safety, temporary steel grandstands are usually strengthened with the diagonal stiffeners of tubular cross...