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Search results for: RHEOLOGICAL%20PROPERTIES
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The properties of reduced Bi-Ge-O glasses for thermoelectric devices
PublicationThe bismuth-germanate glasses have been investigated to examine their applicability for thermoelectric devices. In order to increase their electrical conductivity, the 25Bi2O3–75GeO2 glass samples have been reduced at 340-380°C for 10 hours in hydrogen. It has been shown that such heat treatment in H2 leads to the reduction of metal ions Bi3+ and Ge4+ into neutral atoms and the formation of metal grains both in an amorphous glass...
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The properties of reduced Ge-Sb-O glasses for thermoelectric devices
PublicationThe structural and electrical properties of germanium-antimonate glasses after heat treatment in hydrogen have been determined. In the case of 50GeO2-50Sb2O3 glass reduced at 340°C even for less than 1 hour a continuous layer of antimony granules is formed and its electrical properties determine the surface conductivity of the reduced sample. The bulk electrical conductivity at 100°C of this sample was determined as 1000 Scm-1...
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Mechanical Properties of Polyester Coated Fabric Subjected to Biaxial Loading
PublicationThe paper is focused on the comparison between uniaxial and biaxial laboratory test results for polyester coated fabric. A short literature review concerning coated woven fabrics with emphasis on biaxial tensile tests is presented. A description of the polyester-coated fabric under biaxial test by means of constitutive models and material parameter values is proposed. To establish the right values of the ultimate tensile strength,...
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Influence of sensor design and optical properties of tissue on the photoplethysmographic signal
PublicationPhotopletysmography and an associated technique called pulse oximetry are still explored due to the expectations that they give a lot of information about the state of the patient and, also, due to the fact that they are non invasive. Knowledge about the impact of various parameters on the measured signal leads to a faster and a more reliable way of analyzing measurement results and finding the dependencies between the involved...
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Mechanical properties of PVDF-coated fabric under tensile tests
PublicationThis article describes the laboratory tests necessary to identify the mechanical properties of the polyvinylidene fluoride (PVDF)-coated fabrics named Precontraint 1202S and Precontraint 1302S. First, a short survey of the literature concerning the description of coated woven fabrics is presented. Second, the material parameters for PVDF-coated fabrics are specified on the basis of biaxial tensile tests. A comparison of the 1:1...
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Influence of electropolymerization conditions on the morphological and electrical properties of PEDOT film
PublicationIn this work the effects of electropolymerization conditions on the morphological properties and conductivity of poly(3,4-ethylenedioxythiophene) (PEDOT) film have been studied. PEDOT films were electrochemically synthesized in a one step process from acetonitrile solution containing 3,4-ethylenedioxythiophene (EDOT) and lithium perchlorate. Based on atomic force microscopy, scanning electron microscopy, cyclic voltammetry and...
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Constructional properties of polycarbonate plates for EURO 2012 Gdansk stadium
PublicationPrzedstawiono wyniki badań doświadczalnych dla płyt z poliwęglanu litego, które miały zostać wykorzystane jako materiał konstrukcyjno-osłonowy stadionu piłkarskiego na mistrzostwa Euro 2012 w Gdańsku. Zidentyfikowano moduł Younga oraz Poissona, wykonano próby cykliczne oraz pełzania. Właściwości mechaniczne poliwęglanu litego oceniono jako dobre, choć obawy budzą mikrorysy pojawiające się podczas badań w strukturze materiału.
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The effect of mercerized sisal fibres on natural rubber composites' properties
PublicationW pracy omówiono wyniki badań fizyko-mechanicznych kompozytów otrzymanych z mieszanek zawierających kauczuk naturalny oraz statystycznie zdyspergowane krótkie włókno sisalowe. Włókno naturalne przed użyciem poddano merceryzacji.Otrzymane wulkanizaty poddano badaniom wytrzymałościowym w warunkach statycznych w celu określenia wpływu parametrów wulkanizacji i ilości dodanego włókna na właściwości otrzymanych produktów. Stwierdzono...
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Influence of Glycols on the Glycolysis Process and the Structure and Properties of Polyurethane Elastomers
PublicationW pracy omówiono wyniki badań elastomerów wytworzonych z glikolizatów poddanych dezaminacji. Glikolizaty otrzymywano w procesie transestryfikacji polieterouretanów glikolami: propano-1,3-diolem, pentano-1,5-diolem oraz heksano-1,6-diolem. Procesy prowadzono przy trzech stosunkach masowych pianki:glikolu.
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Properties of Composite Modified with Limestone Powder for 3D Concrete Printing
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Minerals, Essential Oils, and Biological Properties of Melissa officinalis L.
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Influence of dipalmitoylphosphatidylcholine (or dioleoylphosphatidylcholine) and phospholipase A2 enzyme on the properties of emulsions
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Biological Properties of Essential Oils from Thymus algeriensis Boiss
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The Effect of Adhesive Additives on Silica Gel Water Sorption Properties
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The Influence of Nano-Fe3O4 on the Microstructure and Mechanical Properties of Cementitious Composites
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Iron filled singlewalled carbon nanotubes – synthesis and characteristic properties
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The Effect of Nanosilica on the Mechanical Properties of polymer-Cement Composites (PCC)
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Facile synthesis and properties of iron oxide spheres coated with carbon
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Effect of perlite waste addition on the properties of autoclaved aerated concrete
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Polyurethane Glycerolysate as a Modifier of the Properties of Natural Rubber Mixtures and Vulcanizates
PublicationChemical recycling of polyurethanes can be realized in several different ways, but the most important methods are glycolysis and glycerolysis. Both methods permit recovery of polyols (when the process is realized with the mass excess of depolymerizing agent) or substitutes of polyols, which contain urethane moieties in the main chains and terminate mainly in hydroxyl groups (when the process is realized with the mass excess of...
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Dielectric Spectroscopy Studies and Modelling of Piezoelectric Properties of Multiferroic Ceramics
PublicationCompounds and solid solutions of bismuth ferrite (BiFeO3)—barium titanate (BaTiO3) system are of great scientific and engineering interest as multiferroic and potential high-temperature lead-free piezoelectric materials. In the present paper, the results of research on the synthesis and characterisation of 0.67Bi1.02FeO3–0.33BaTiO3 (67BFBT) ceramics in terms of crystal structure and dielectric and piezoelectric properties are reported....
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Electrical properties of organic and perovskite systems used in solar cells
PublicationNowadays, a great progress in the areas of molecular and hybrid photovoltaics is observed. The devices based on organic and perovskite materials are getting attention mostly due to their low cost production process. However, their efficiency and stability are still lower than for inorganic materials which make them less popular. Therefore, a detailed understanding of the device physics is fundamental for organic and perovskite...
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Effect of ionic liquids on surface and photocatalytic properties of selected semiconducttors
PublicationThe main aim of this doctoral dissertation was to explain the role of ionic liquids in shaping the morphology of selected semiconductors, thereby enhancing the photocatalytic activity. In order to achieve this goal, the following research steps were taken: (i) developing synthesis methods of selected semiconductors, with particular emphasis on the electrochemical oxidation method; (ii) understanding the influence of the selected...
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Heat capacities and thermodynamic properties of antimony substituted lanthanum orthoniobates
PublicationThe results of heat capacity measurements for the lanthanum orthoniobate substituted with 10, 20 and 30 mol% of antimony (LaNb0.9Sb0.1O4, LaNb0.8Sb0.2O4 and LaNb0.7Sb0.3O4) are presented and discussed. Temperature dependence of low temperature heat capacity was analyzed within the Debye and Einstein models. The Debye temperature decreased, whereas the Einstein temperature increased with antimony content. The decrease of the Debye...
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Luminescent properties of Ln3+ doped tellurite glasses containing AlF3
PublicationThe low-phonon energy tellurite glasses TeO2-BaO-Bi2O3 and TeO2-BaO-Bi2O3-AlF3 triply doped with Eu3+, Tb3+, Tm3+ ions in two different molar ratios were synthesized using melt-quenching technique. Their structure and luminescence properties were widely investigated by X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR) and Photoluminescence Spectroscopy (PL). The luminescence...
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Physical properties and electronic structure of La3Co and La3Ni intermetallic superconductors
PublicationLa3Co and La3Ni are reported superconductors with transition temperatures of 4.5 and 6 K, respectively. Here, we reinvestigate the physical properties of these two intermetallic compounds with magnetic susceptibility χ, specific heat Cp and electrical resistivity ρ measurements down to 1.9 K. Although bulk superconductivity is confirmed in La3Co, as observed previously, only a trace of it is found in La3Ni, indicating that the...
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Chemical modifications of graphene and their influence on properties of polyurethane composites: a review
PublicationPolyurethane composites are materials of great interest nowadays due to their wide range of available forms and applications in industry. Controlling and achieving unique properties via matrix modifications and addition of various specific nanofillers seems be one of the key elements to success. The purpose of this work is to briefly present some examples of graphene nanoderivatives, their syntheses, properties and influence on...
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Influence of thermal effects on mechanical properties of PVDF-coated fabric
PublicationThis paper describes the method of laboratory tests necessary for identification of temperature influence on mechanical properties of polyvinylidene fluoride-coated polyester fabric often used for tensile structures. Two nonlinear model descriptions are investigated. The first one is based on the piece-wise linear relations between stress and strain and the second one on the Murnaghan model of solid behavior. This paper is proposed...
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Properties of Nasicon-based CO2 sensor with Bi8Nb2O17 reference electrode
PublicationGas 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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Luminescence properties of Eu3+ and Tb3+ doped silica-based xerogels
PublicationPure SiO2 xerogels and SiO2 xerogels containing SrF2: Eu3+/: Tb3+ crystals were prepared using sol-gel method. Luminescent spectra showed excitation and emission peaks characteristic to Eu3+ and Tb3+ 4f - 4f transitions. ET Tb3+→Eu3+ has been observed. XRD pattern of SiO2 matrix confirmed lack of long range order. Patterns of SiO2-SrF2:Eu3+ and SiO2-SrF2:Tb3+ showed peaks corresponding to SrF2. SEM images have shown agglomerates...
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Electrochemical Activity and Electrical Properties of Optimized Polypyrrole Coatings on Iron
PublicationIn this work, electrochemical activity and electrical properties of polypyrrole (PPy) coated iron electrodes have been investigated. PPy film was electrochemically polymerized from sodium salicylate aqueous solution under conditions, which provided an increase of iron corrosion resistance. It was noticed that the pH of the solution and the applied electrode potential range during the study of the polymer properties had an influence...
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Thermal and mechanical properties of polyurethanes modified with L-ascorbic acid
PublicationIn this study we report the thermal and mechanical properties of polyurethanes modified with ascorbic acid (AA). Ascorbic acid was used as a modifier at concentration of 1 or 2 mass%. The antioxidative properties of AA may improve the biocompatibility of the obtained materials, which were designed for biomedical applications. In this paper we describe characterization of obtained unmodified and ascorbic acid modified polyurethanes...
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Effect of polymer fibres reinforcement on selected properties of asphalt mixtures
PublicationThe paper presents selected results of the research program concerning fibre reinforced asphalt concrete. Aramid-polyalphaolefin fibres was used in this study. Selected properties responsible for low temperature cracking and resistance to permanent deformation are presented in this paper. Low temperature cracking susceptibility was evaluated with the results obtained from bending test of rectangular beams with constant rate of...
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Effect of Polymerization Statistics on the Electronic Properties of Copolymers for Organic Photovoltaics
PublicationStatistical block copolymers, composed of donor (D) and acceptor (A) blocks, are a novel type of material for organic photovoltaics (OPVs) devices. In particular a new series of polymers based on PBTZT-stat-BDTT-8, recently developed by Merck, offers high solubility in different solvents, and a high power conversion efficiency (PCE) in different device architectures. Although it is known that the electronic properties of these...
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Five-phase squirrel-cage motor. Construction and drive properties
PublicationThis paper presents the simulation and experimental results of a five-phase squirrel-cage induction motor. The new machine has been designed to operate in a drive system with third harmonic rotor flux injection in order to improve the motor torque utilization. The motor structure, the mathematical model as well as the laboratory prototype have been described. The motor speed-torque characteristics and transients are elaborated...
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Asymptotic properties of quadratic stochastic operators acting on the L1 space
PublicationQuadratic stochastic operators can exhibit a wide variety of asymptotic behaviours and these have been introduced and studied recently in the ℓ1 space. It turns out that in principle most of the results can be carried over to the L1 space. However, due to topological properties of this space one has to restrict in some situations to kernel quadratic stochastic operators. In this article we study the uniform and strong asymptotic...
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Synthesis and properties of carboxy derivative of Epidian 6 monomethacrylate (in English)
PublicationWe present the synthesis of an oligomer with carboxy and methacrylic groups based on Epidian 6. The effect of the catalyst nature and amount, solvent nature and process temperature on the rate of the reaction between Epidian6 monomethacrylate and adipic acid was examined at 313, 323 and 333 K in the presence of 4-dimethylaminopyridine, 1,4-diazobicyclo[2.2.2]octane, and benzyltriammonium chloride. The synthesized oligomer was characterized...
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PROPERTIES OF PARAMETRIC ALGORITHMIC DESIGN OF RESIDENTIAL HOUSES IN URBAN CONTEXT
PublicationDesign explorations of architectural avant-garde resulted in the development of digital techniques that allow solving very complex and demanding contemporary design challenges. In the architectural discourse the new design workshop seems to be symbolized mainly by the projects of sports facilities, cultural, administrative or multifunctional high-rise buildings. However for the quality of society life is more important to exploit...
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Properties and Formation of Mineralized Veins in an Organic-Rich Shale Formation
PublicationAn earlier paper defined mineral and organic matter constituents in weak interfaces in shale formations (Ptaszynska, et. al., 2016). The formation studied in the earlier work and here is the Jurassic, early-Cretaceous Vaca Muerta formation in the Neuquen basin in Argentina. In this earlier work, mineralized "veins" were noted to be prevalent and complicated, sometimes being shear weak interfaces while in other cases they were not....
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The influence of rubber recyclate morphology on the properties of rubber-asphalt composite
PublicationIn the paper wastes, mostly in the form of used tires, were analyzed. One of the methods of waste tires application use them as a modifier of asphalt. However, the properties of rubber-asphalt composites depend on the morphology of waste tiregranulate and kind of tire recycled (car/truck). In this chapter, the influence of grinding methods of waste tire on the prop¬erties of rubber-asphalt composites were studied. SEM analysis...
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Mechanical Properties of a Dike Formed from a Soil-ash Composite
PublicationThe 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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Problems with modelling the strength properties of sailing vessels rigging ropes
PublicationThis article presents the basic parameters of soft ropes: natural fibre ropes, soft wire ropes and synthetic fibre ropes used for running rigging. There are only several materials still used for the production of natural fibre ropes, including cotton, jute, hemp, sisal and manila hemp. The most commonly used soft wire ropes are twisted pair ropes; for smaller diameters there is a 6x19M - FC rope and for larger diameters – 6x37M...
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Analysis of Denoising Autoencoder Properties Through Misspelling Correction Task
PublicationThe paper analyzes some properties of denoising autoencoders using the problem of misspellings correction as an exemplary task. We evaluate the capacity of the network in its classical feed-forward form. We also propose a modification to the output layer of the net, which we called multi-softmax. Experiments show that the model trained with this output layer outperforms traditional network both in learning time and accuracy. We...
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Sorption properties of asphaltene stationary phases for gas chromatography separations
PublicationW pracy przedstawiono wyniki badań nad możliwością wykorzystania faz stacjonarnych na bazie frakcji asfaltenowych do rozdzielania mieszanin związków chemicznych z wykorzystaniem chromatografii gazowej oraz porównano selektywność faz przygotowanych z frakcji asfaltenowych wyizolowanych z różnych surowców. Na podstawie uzyskanych wyników obliczono wartości liniowych indeksów retencji oraz stałych Rohrschneidera McReynoldsa, za pomocą...
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Tailoring properties of reduced graphene oxide by oxygen plasma treatment
PublicationWe report an easily controllable, eco-friendly method for tailoring the properties of reduced graphene oxide (rGO) by means of oxygen plasma. The effect of oxygen plasma treatment time (1, 5 and 10 minutes) on the surface properties of rGO was evaluated. Physicochemical characterization using microscopic, spectroscopic and thermal techniques was performed. The results revealed that different oxygen-containing groups (e.g. carboxyl,...
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An in situ technique for the assessment of adhesive properties of a joint under load
PublicationSlow crack propagation in adhesive bonded joints has been characterised using an asymmetric wedge test. Crack position was evaluated from strain gauge measurements, both in the debonded partof the joint and in the bonded zone. Test temperature was changed during loading, giving insight into bond evolution. The technique allows accurate, and virtually continuous, determination of crack position to be made, and therefore the evaluation...
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Pyrrole azocrown ethers - synthesis, crystal structures, and fluorescence properties
PublicationZsyntezowano nowe związki makrocykliczne zawierające w makropierścieniu pierścień pirolowy, grupy azowe oraz reszty chromoforowe i fluorescencyjne. Scharakteryzowano strukturę krystaliczną dwóch spośród otrzymanych makrocykli metodą rentgenografii strukturalnej. Stwierdzono, że zaprezentowane pirolowe azokorony to związki czułe i selektywne na jony ołowiu(II) oraz, że mogą być użyte jako chemosensory zarówno w spektroskopii UV-Vis,...
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Water and chemical properties of hydrometeors over central european mountains
PublicationAtmospheric pollutants are transferred to the groundby the contribution of various types of hydrometeors. Because ofthe different techniques of measurement, comparative analysesbetween them are often neglected. Hence, the main goal is tocompare water volume and chemistry of different types ofhydrometeors and their role in both: water balance and pollutantsdeposition. The results of water input and atmospheric depositschemistry...
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Effect of boundary conditions in shear testers on properties of bulk solids.
PublicationPrzedstawiono wpływ warunków brzegowych w dwóch różnych aparatach ścinania na wielkość odkształceń i naprężeń. Obliczenia wykonano przy zastosowaniu metody elementów skończonych i mikropolarnego prawa hipoplastycznego.
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Shape Memory Polyurethane Materials Containing Ferromagnetic Iron Oxide and Graphene Nanoplatelets
PublicationIntelligent materials, such as memory shape polymers, have attracted considerable attention due to wide range of possible applications. Currently, intensive research is underway, in matters of obtaining memory shape materials that can be actuated via inductive methods, for example with help of magnetic field. In this work, an attempt was made to develop a new polymer composite—polyurethane modified with graphene nanoplates and...