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Wyniki wyszukiwania dla: NANOMECHANICAL PROPERTIES
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Impact of blending with polystyrene on the microstructural and electrochemical properties of SiOC ceramic
PublikacjaIn this work, we present the electrochemical behavior and microstructural analysis of silicon oxycarbide (SiOC) ceramics influenced by an addition of polystyrene (PS). Polymer-derived ceramics were obtained by pyrolysis (1000°C, Ar atmosphere) of different polysiloxanes prepared by sol–gel synthesis. This method is very effective to obtain desired composition of final ceramic. Two alkoxysilanes phenylthriethoxysilane and diphenyldimethoxysilane...
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Vibrational Properties of LaNb0.8M0.2O4-δ (M=As, Sb, V, and Ta)
PublikacjaLaNb0.8M0.2O4-δ (where M=As, Sb, V, and Ta) oxides with pentavalent elements of different ionic sizes were synthesized by a solid-state reaction method. The vibrational properties of these oxides have been investigated. These studies revealed that the substituent element influences both Debye temperature value as well as the Raman active vibrational modes. Additionally, the low-temperature vibrational properties of LaNb0.8Sb0.2O4-δ...
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Characterization of structural, thermal and mechanical properties of bismuth silicate glasses
Publikacjahe influence of heating and reduction processes on the structural, thermal and mechanical properties of bismuth-silicate glasses has been investigated. Two compositions of glasses: 40Bi2O3–60SiO2 (Bi0.57Si0.43Ox) and 27Bi2O3–73SiO2 (Bi0.43Si0.57Ox) were fabricated by a typical melt quenching technique. Then the reduction in hydrogen at 380 °C for 20, 42 or 67 h was performed. It was found that a 50 μm-thick layer was formed on...
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Heat capacities and thermodynamic properties of antimony substituted lanthanum orthoniobates
PublikacjaThe 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
PublikacjaThe 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
PublikacjaLa3Co 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
PublikacjaPolyurethane 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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Thermal and mechanical properties of polyurethanes modified with L-ascorbic acid
PublikacjaIn 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
PublikacjaThe 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
PublikacjaStatistical 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
PublikacjaThis 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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Properties and Formation of Mineralized Veins in an Organic-Rich Shale Formation
PublikacjaAn 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
PublikacjaIn 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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Polysaccharide-based electroconductive hydrogels: Structure, properties and biomedical applications
PublikacjaArchitecting an appropriate platform for biomedical applications requires setting a balance between simplicity and complexity. Polysaccharides (PSAs) play essential roles in our life in food resources, structural materials, and energy storage capacitors. Moreover, the diversity and abundance of PSAs have made them an indispensable part of food ingredients and cosmetics. PSA-based hydrogels have been extensively reviewed in biomedical...
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The assessment of metrological properties of segmental orifice based on simulations and experiments
PublikacjaSegmental orifices are often used to measure flows of heterogeneous mixtures, especially in flow meters in the power industry, for example. The orifice (with module m= 0.25) was installed in a stainless-steel pipe with internal diameter of 50 mm, placed in a hydraulic water system. The research was performed for Reynolds numbers ranging from 9,000 to 17,000. The flow characteristics of this orifice obtained based on simulation...
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The protective properties of graphene oxide coatings functionalized with phosphorus atoms.
PublikacjaRecently, electrophoretically deposited graphene oxide coatings are commonly applied as an anti-corrosion layer. However, improper adjustment of electrophoretic deposition (EPD) parameters as well as the hydrophilic nature of graphene oxide contribute to the formation of defects in the coatings and the increase in the wetting properties, respectively, and thus lead to a reduction of protective properties. The growth of wetting...
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Measurements of the optical and thermal properties of the 2D black phosphorus coating
PublikacjaBlack phosphorus is a 2D material, which properties are still being discovered. In this paper, the sensitivity to the temperature of a few-layer black phosphorus coating deposited, on the surface of a microsphere-based fiber-optic sensor, by a dip-coating method is presented. The coating was investigated after 2, 3, and 5 deposition cycles and during temperature growth from 50 °C to 300 °C in an interferometric setup. The intensity...
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Structure and transport properties of donor-doped barium strontium cobaltites
PublikacjaIn this work, Nb-substituted barium strontium cobaltites Ba0.5Sr0.5Co1-xNbxO3-δ (x = 0 – 0.4) have been fabricated and studied. The structural analysis showed that the Nb content influences the lattice constant as well as the distance between the (Co, Nb) and oxygen atoms. The study of morphology of samples showed that the Nb content does not change the porosity, grain size and morphology of the ceramics. The total electrical conductivity...
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Electrical properties of organic and perovskite systems used in solar cells
PublikacjaNowadays, 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
PublikacjaThe 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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Ionic liquids in the microextraction techniques: the influence of ILs structure and properties
PublikacjaIonic liquids (ILs) are composed entirely of ions thus they possess unique properties, including negligible volatility, a liquid state in a broad range of temperatures and ability to change them depending on the chosen type of anion and cation, which make ILs unique and useful for many applications in sample preparation techniques. A deeper understanding of the nature of ILs and the impact of their structure on their parameters...
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Metabolomic and antioxidant properties of different varieties and origins of Dragon fruit
PublikacjaDragon fruit has appealed much concern from consumers as a novelty fruit with potent nutritional and medicinal benefits. Dragon fruit quality warrants comprehensive evaluation, based on the contents of pigments and health- promoting natural compounds in different varieties. This study was aimed to evaluate the differences among dragon fruit varieties extracted with methanol–water (CD3OD-D2O) and methanol (CD3OD) by proton nuclear magnetic...
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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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Crystal structure and physical properties of a novel ternary compound La15MoxGe9
PublikacjaWe present the synthesis, structural characterization and physical properties measurements of a new compound, La15MoxGe9 in Mn5Si3-type derived structure with interstitial Mo. The sample was synthesized by arc-melting method. La15MoxGe9 crystallizes in non-centrosymmetric hexagonal structure P63mc (#186) with lattice parameters a = b = 15.495(5) Å and c = 6.917(2) Å. The refinement on single X-ray diffraction data show that interstitial...
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Anticancer Properties of Amino Acid and Peptide Derivatives of Mycophenolic Acid
PublikacjaBackground: Although Mycophenolic Acid (MPA) is applied as prodrugs in clinic as an immunosuppressant, it also possesses anticancer activity. MPA acts as Inosine-5’-Monophosphate Dehydrogenase (IMPDH) inhibitor, where the carboxylic group at the end of the side chain interacts with Ser 276 of the enzyme via hydrogen bonds. Therefore, MPA derivatives with other polar groups indicated high inhibition too. On the other hand, potent...
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Sources, properties and suitability of new thermostable enzymes in food processing
PublikacjaW niniejszym artykule przedstawiono przegląd badań wskazujących na przydatność rekombinantowej alfa-amylazy z Pyrococcus woesei i alfa glukozydazy z Thermus thermohilus do jednoetapowego wytwarzania syropów skrobiowych. Rekombinantowa beta-glikozydaza z Pyrococcus woesei może być natomiast stosowana do produkcji bezlaktozowych produktów z mleka i serwatki. Zachowanie aktywności w szerokim zakre-sie pH od 4,3 do 6,6 oraz duża termostabilność...
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Properties of PA6/thermoplastic polyurethane and PA6/polyurethane nanocomposite blends
PublikacjaPrzedstawiono wyniki badań właściwości i struktury mieszanin i nanokompozytów układów PA6/termoplastyczny poliuretan. W przypadku nanokompozytów wprowadzano nanonapełniacz w postaci montmorylonitu. Zbadano właściwości termiczne i wytrzymałościowe oraz omówiono wyniki analiz strukturalnych, otrzymanych z dyfrakcji rentgenowskiej i mikroskopii elektronowej.
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Synthesis, physical and chemical properties of polyetherurethanes modified by natural antioxidant
PublikacjaOtrzymano nowe polieterouretany modyfikowane witaminą E. Ten naturalny przeciwutleniacz związany został z makrocząsteczkami w postaci bocznych odgałęzień poprzez wiązanie eterowe lub uretanowe, zależnie od użytego w syntezie jednego z dwóch rodzajów otrzymanych uprzednio monomerów. Polimery scharakteryzowano mierząc wytrzymałość na rozciąganie i twardość oraz absorpcję wody i oleju słonecznikowego. Odporność chemiczną badano oznaczając...
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Effect of boundary conditions in shear testers on properties of bulk solids.
PublikacjaPrzedstawiono 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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Structurally well-defined functionalized polyolefins and graft copolymers thereof as bitumen modifiers
PublikacjaHere we demonstrate the application of hydroxyl-functionalized propylene-based copolymers, poly(propylene-co-1-hexene-co-10-undecen-1-ol) (FPP) and poly(styrene-co-maleic anhydride) (SMA) graft copolymers derived thereof, poly(propylene-co-1- hexene-graft-styrene-co-maleic anhydride) (FPP-g-SMA) as bitumen modifiers. The FPP samples were synthesized via solution copolymerization, while FPP-g-SMA products were obtained via transesterification...
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Luminescence properties of TeOx gels
Dane BadawczeThe DataSet contains the emission and excitation spectra of TeOx gels. The material was obtained by the sol-gel method. The starting solution was prepared by mixing telluric acid (precursor) with thetraetylene glycol, water, and ethanol. The sol was obtained by vigorously stirring precursor solution at 50°C for 2h, then the temperature was raised...
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Maria Gazda prof. dr hab. inż.
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Properties of New Composite Materials Based on Hydroxyapatite Ceramic and Cross-Linked Gelatin for Biomedical Applications
PublikacjaThe main aim of the research was to develop a new biocompatible and injectable composite with the potential for application as a bone-to-implant bonding material or as a bone substitute. A composite based on hydroxyapatite, gelatin, and two various types of commercially available transglutaminase (TgBDF/TgSNF), as a cross-linking agent, was proposed. To evaluate the impacts of composite content and processing parameters on various...
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Numerical analysis of mechanical properties of an infill structure used in 3D printings
PublikacjaThe paper presents results of a numerical analysis focused on an identification of mechanical properties of an element created by using Fused Deposition Modelling additive manufacturing technique (FDM). There is presented a description of technology of the 3D printing, numerical model created by using the finite element method (FEM), as well as some problems referred to estimation of the mechanical properties of the printout. The...
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Structural and electrical properties of Cr-doped SrTiO 3 porous materials
PublikacjaSeries of single-phase materials with assumed formula SrTi1−xCrxO3 (where x = 0, 1, 4, 6 mol.%) were obtained by sol-gel method. The structure and microstructure of materials were characterised by X-ray diffraction and scanning electron microscopy methods. Moreover, the study of electrical properties and evaluation of chemical stability in CO2/H2O atmosphere was performed by electrochemical impedance spectroscopy and thermogravimery...
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Electrical properties of Na2O-CaO-P2O5 glasses doped with SiO2 and Si3N4
PublikacjaSodium-calcium-phosphate glasses doped with SiO2 or Si3N4 having similar sodium ion concentrations were prepared by melt quenching. The conductivity was measured by impedance spectroscopy under nitrogen atmosphere in a wide frequency range (10 mHz–1 MHz) and wide temperature range (153–473 K). At 36.6 °C, DC conductivities of all glasses vary between 1.1 ∗ 10−12 and 8.9 ∗ 10−12 S cm−1 and have similar activation energies (between...
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Effect of Coating Material Properties on Tilting-pad Thrust Bearing Performance
PublikacjaPolymer lined tilting-pad bearings demonstrate many advantages over traditional bearing systems. Bearings with a polymer layer in comparison with a babbitted layer show, for example: lower value of friction coefficient (important during start/stops), higher fatigue strength of the coating, better distribution of the load on individual pads due to lower elasticity of the polymers, wider range of operational temperatures or the ability...
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Preparation, composition and properties of fish silage produced with post-coagulation sludge
PublikacjaPost-coagulation sludge was added to fish fydrolyzates (silage). Silage was prepared using whole sprats. Technology of the process has been modified and sulphuric acid was replaced with phosphoric acid. The objective was to evaleuate the quality of produced silage during storage, particulary the changes of peroxide value and amount of free acids in silage fat.
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The external walls of a passive building: A classification anddescription of their thermal and optical properties
PublikacjaThis paper attempts a new classification of insulating materials from the perspective of their utility in thepro-ecological passive construction industry. The main criterion is the conductivity of thermal and solarenergy. Based on their ability to conduct or block fluxes of thermal and solar energy, six types of insulatingwalls are proposed. On the basis of this criterion there are traditional dividing walls (typical walls, wallinsulating...
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MECHANICAL PROPERTIES OF BOTTOM ASH – DREDGED MATERIAL MIXTURES IN LABORATORY TESTS
PublikacjaBottom ash from EC Gdańsk and dredged material taken from the mouth of The Vistula were mixed to form an engineering material used for dike construction. Mixtures with different bottom ash content were tested in laboratory to determine its basic physical and mechanical properties. The optimum bottom ash–dredged material mixture, built in the corps of the test dike, contains 70% of ash. The optimum bottom ash content in the mixture...
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Electrical properties of Y0.08Sr0.92Ti0.92Nb0.08O3-δ after reduction in different reducing conditions
PublikacjaElectrical properties of perovskite Y0.08Sr0.92Ti0.92Nb0.08O3−ı after reduction in different conditions were studied. Relatively high electrical conductivity in samples reduced in ammonia was observed. The conductivity of Y0.08Sr0.92Ti0.92Nb0.08O3−ı reduced in ammonia at 1500 ◦C was of about 600 S/cm at 200 ◦C. Conductivity after reduction in ammonia at 1500 ◦C was stable both in hydrogen and oxygen atmosphere up to 600 ◦C. Reduction...
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Mechanical properties of polyvinyl chloride-coated fabric under cyclic tests
PublikacjaThe aim of the present paper is to propose a method of laboratory tests necessary for the identification of mechanical properties of the coated fabric. The material parameters of the coated fabric AF 9032 are specified on the basis of the uniaxial and biaxial tensile tests. For the identification process, the techniques based on the least squares methods are used. Additionally, the uniaxial and biaxial cyclic tests are performed...
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Influence of the internal electrolyte composition on amperometric sulphur dioxide sensor properties
PublikacjaIn this work investigation of an amperometric sulphur dioxide sensor with a liquid electrolyte, a mercury sulphate reference electrode and solid polymer electrolyte (Nafion) covered with gold as a working electrode properties is presented. The main goal of this research is to determine the influence of internal electrolyte composition on the sensor properties. Sensor filled with 1M and 5M sulphuric acid has been studied.
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Microstructural and electrical properties of Y0:07Sr0:93−xTiO3− perovskite ceramics
PublikacjaIn order to find a relationship between electrical and microstructural properties, yttrium-doped strontium titanate (7 mol%) with various values of strontium nonstoichiometry was investigated and shown in this work. It has been observed that yttrium doping can affect the electrical properties of SrTiO3 to a great extent. Moreover, the microstructural and electrical properties can be influenced by strontium nonstoichiometry. The...
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Electrical properties and structure of lead-borate glass containing iron ions.
PublikacjaThe ac and dc conductivity in iron–lead-borate glass samples was investigated in the frequency range from 1 mHz to 1 MHz and in the temperature range from 153 K to 423 K. The structure was investigated by the means of atomic force microscopy (AFM) and the crystalline phases (if present) were identified by the means of X-ray diffractometry. Two types of ac electrical behaviour were observed. The first group of glass samples which...
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Interline power flow controller - properties and control strategy in dynamic states
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Properties of sensorless control systems based on multiscalar models of the induction motor
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Electrical properties and structure of lead-borate glass containing iron ions
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Crystal structure and physical properties of a novel ternary compound La15Mo Ge9
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The scintillation properties of Ce x La 1−x F 3
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