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EN
The paper analyzes the impact of urban areas on the state of water objects which are under the influence of these areas. Furthermore, the temporal regularities of the oscillations in electrical conductivity in a number of water objects in Lozova Town and Lozova District (Ukraine) were obtained using the method of conductometry. It was discovered that there was no significant anthropogenic impact on the studied water objects in Lozova Town and Lozova District of Kharkiv Region. The fluctuations in conductivity are mainly related to surface runoff. It was shown that the water in Lozova Town and Lozova District is characterized by electrical conductivity values in the range from 2000 μS to 3000 μS.
EN
The study investigates the effect of heat treatment on the microstructure evolution and properties of an age-hardened Cu-3Ti-2Mg alloy. The precipitated Cu2Mg and β'-Cu4Ti phases consequently yield a depletion of the Cu matrix in regards to Ti and Mg solutes, which enhances the electrical conductivity. The Cu2Mg Laves phase and β'-Cu4Ti phase precipitates increase the hardness of the alloy due to the consistency and coherency of the later phase. However, the decrease of hardness is mainly associated with the coarse microstructures, that can be formed due to the phase transformation from metastable β'-Cu4Ti phase to more stable Cu3Ti phase. In the range of experiments, the optimum process is solution treatment at 700°C for 4 h, with subsequent age-hardening at 450°C for 4 h. The electrical conductivity, hardness, tensile strength, and elongation of the Cu-3Ti-2Mg alloy were 15.34 % IACS, 344 HV, 533 MPa, and 12%, respectively.
PL
Celem badań była analiza przewodności elektrycznej biowęgla uzyskanego z materiału organicznego metodą pyrolizy. W celu wykonania pomiarów właściwości elektrycznych biowęgla, zbudowano prototypowe urządzenie. Oprócz pomiarów właściwości elektrycznych umożliwia ono m.in. pomiar gęstości właściwej dowolnej próbki materiału sypkiego. W rozpatrywanym przypadku po napełnieniu komory roboczej i zagęszczeniu proszku otrzymywano pastylkę węglową. Dla niej określano pomiarami bezpośrednimi właściwości elektryczne tj.: spadek napięcia przy przepływie prądu przez próbkę (prąd stały i przemienny), oporność rezystora węglowego, wartość prądu przepływającego przez rezystor, indukcyjność oraz pojemność. Ponadto przy pomocy oscyloskopu rejestrowano charakterystyki dynamiczne napięcia w odniesieniu do prądu przemiennego przepływającego przez rezystor węglowy. Stwierdzono, że badanym próbkom można przypisać cechy obiektu elektronicznego o charakterze pojemnościowym.
XX
The aim of the research was to analyze the electrical conductivity of the obtained coal from organic material by pyrolysis. In order to take measurements of the electrical properties of the biochar, a prototype device was built. In addition to measurements of electrical properties, it enables measurement of the specific density of any sample of bulk material. In the case under consideration, after filling the working chamber and concentrating the powder, a carbon pellet was obtained. For it, direct electrical properties were determined by direct measurements, it is: voltage drop at the current flow through the sample (direct and alternating current), resistance of the carbon resistor, value of current flowing through the resistor, inductance and capacity. In addition, the dynamic characteristics of the voltage with respect to the alternating current flowing through the carbon resistor were recorded using the oscilloscope. It has been noted that capacitive features can be attributed to the test samples.
4
Content available remote DC electrical conduction in strontium vanadium borate glasses
EN
A series of borate glasses with the composition x(SrO)∙(50 – x)V2O5∙0.5(B2O3) where x = 0, 0.1, 0.2, 0.3 and 0.4 were prepared by melt-quenching technique. The non-crystalline nature of the glasses has been established by XRD studies. Room temperature density and DC electrical conductivity of the samples were investigated in the temperature range of 300 K to 443 K. The molar volume and oxygen packing density (OPD) were estimated. The results show that the density, molar volume and OPD decrease with the increasing of SrO mole fraction. The DC electrical conductivity data has been analyzed in the light of Mott’s small polaron hopping (SPH) model and the activation energies were estimated. The conductivity was observed to rapidly fall and activation energy was found to increase when SrO was incorporated into the glass network. This may indicate that Sr+ ions have not contributed to the total conductivity and the observed conductivity may be of polaronic type only, which is due to the hopping of electrons between multivalent states of vanadium. Various small polaron hopping parameters such as small polaron radius, rp, effective dielectric constant, ϵp, polaron band width, J, optical phonon frequency, ʋo, small polaron coupling constant, ϒp, density of states at Fermi level, N(EF) were estimated and discussed.
EN
This work is focused on environmental pollution monitoring utilizing thin metal electrodes on glassy/ceramic substrates prepared by physical vapour deposition. Besides others, it is well known that environmental pollution on electrical insulation is one of the problems faced by distribution utilities and electricity transmission system. Due to this reason there is a need to deal with monitoring of environmental pollution as it strongly influences their capability to withstand the high-voltage stress without the breakdown. It is the aim of present work to propose new system for environmental pollution monitoring based on application of extra-thin metal electrodes. The influence of morphology and chemical composition of pollutants on the surface resistance and conductivity of selected insulators is also discussed.
PL
Artykuł dotyczy monitorowania zanieczyszczenia środowiska za pomocą cienkich elektrod metalowych na szklanych/ceramicznych podłożach przygotowanych przez fizyczne osadzanie z fazy gazowej. Widomym jest, że zanieczyszczenie środowiska odpadami izolacji elektrycznej jest jednym z problemów, przed którymi stoją firmy dystrybucyjne i system przesyłu energii elektrycznej. Z tego powodu istnieje potrzeba monitorowania zanieczyszczenia środowiska, ponieważ ma to duży wpływ niezawodność sieci wysokiego napięcia i jej awaryjność. Celem przedstawionych prac jest zaproponowanie nowego systemu monitorowania zanieczyszczenia środowiska w oparciu o zastosowanie bardzo cienkich elektrod metalowych. Omówiono także wpływ morfologii i składu chemicznego zanieczyszczeń na rezystancję powierzchniową i przewodnictwo wybranych izolatorów.
EN
In the present study, the creeks and lakes located at the western shore of Admiralty Bay were analysed. The impact of various sources of water supply was considered, based on the parameters of temperature, pH and specific electrolytic conductivity (SEC25). All measurements were conducted during a field campaign in January-February 2017. A multivariate dataset was also created and a biplot of SEC25 and pH of the investigated waters was performed. The average temperatures of the investigated waters were 0.10-8.10 °C. The pH values indicate that most of the water environments of the analysed area are slightly acidic to alkaline (5.26-8.50) with two exceptions: Siodlo II Creek (9.26) and Petrified Forest Creek (8.95), which are characterised by greater alkalinity. At the measurement points closest to the Baranowski Glacier and Ecology Glacier, SEC25 values were the lowest (26.8-61.1 μS·cm–1), while the remaining values ranged from 79.0 to 382 μS·cm–1 for the whole studied area. Based on the results it is concluded that the periodic intensive inflow of ablation waters, combined with morphological changes in the glacier front, causes a significant variability in the outflow network, creating the conditions for changes in basic physicochemical parameters. Moreover, it is observed that local depressions in the terrain form sedimentation traps in which, alongside fine-grained deposits, compounds can accumulate that originate from in situ sedimentation and that are also associated with surface runoff from the melting of snow cover, buried ice and permafrost.
EN
In this research, Co-30 mass% Cr alloys were fabricated by a vacuum hot-press sintering process. Different amounts of submicron cobalt and chromium (the mean grain size is 800 and 700 nm, respectively) powders were mixed by ball milling. Furthermore, this study imposed various hot-press sintering temperatures (1100, 1150, 1200 and 1250°C) and pressures (20, 35 and 50 MPa), while maintaining the sintering time at 1 h, respectively. The experimental results show that the optimum parameters of hot-press sintered Co-30 mass% Cr alloys are 1150°C at 35 MPa for 1 h. Mean while, the sintered density reaches 7.92 g·cm-3, the closed porosity decreases to 0.46%, and the hardness and transverse rupture strength (TRS) values increase to 77.2 HRA and 997.1 MPa, respectively. While the hot-press sintered Co-30 mass% Cr alloys at 1150°C and 20 MPa for 1 h, the electrical conductivity was slightly enhanced to 1.79 × 104 S·cm-1, and the phase transformation (FCC → HCP) of cobalt displayed a slight effect on sintering behaviors of Co-30 mass% Cr alloys. All these results confirm that the mechanical and electrical properties of Co-30 mass% Cr alloys are effectively improved by using the hot-press sintering technique.
EN
This paper presents the results of obtaining and investigations of Pb1-xBax(Zr1-yTiy)1-zSnzO33(PBZTS) ceramics with constant x = 0.03 and y = 0.02, and variable z = 0, 0.04, 0.06 and 0.08 (abbreviations of the samples were following PBZTS0, PBZTS4, PBZTS6, PBZTS8, respectively). The investigated compositions are close to rhombohedral-orthorhombic morphotropic phase boundary. The ceramic samples have been obtained by conventional ceramic technology from simple oxides PbO, ZrO2, TiO2, SnO2 and barium carbonate BaCO3. The ceramic powders, after calcination, have been pressed into discs and sintered using free sintering (FS) method. For samples obtained in such a way, the dielectric properties at various frequencies and electrical conductivity have been investigated. The increase of Sn content orders the microstructure of ceramics, and as a result the improvement of the dielectric properties of ceramic samples can be obtained.
EN
The effects of carbon fiber and its surface treatment through chemical solutions on the mechanical properties and electromagnetic (EM) shielding of ultra-high-performance fiber-reinforced concrete (UHPFRC) were analyzed. Three types of carbon fibers chemically treated with sodium hydroxide, nitric acid, and ammonia solutions were evaluated, along with a plain carbon fiber control sample, at two different concentrations of 0.1% and 0.3% by weight. The surface of carbon fiber was oxidized by chemical solutions. The conductivity of UHPFRC increased with increasing the carbon fiber content, and slightly better conductivity was obtained using the chemically treated carbon fibers than plain fibers at the lower content of 0.1 wt%. Both steel and carbon fibers were effective at improving the shielding effectiveness of ultra-high-performance concrete, and a higher shielding effectiveness was achieved for higher carbon fiber content. Surface treatment using the nitric acid solution was the most effective at enhancing the tensile performance and EM shielding effectiveness, and the best shielding effectiveness (49.0 dB at 1 GHz) was achieved for UHPFRC with 0.1 wt% nitric acid treated carbon fibers. The shielding effectiveness was found to be generally proportional to the electrical conductivity, although its increase was minor relative to that of the conductivity.
EN
Based on the three-dimensional digital core of Berea sandstone, three-phase (matrix, wet clay and free water) digital cores of clay-bearing sandstone are constructed. We divide clay into structural clay and dispersed clay according to the location where clay growth occurs. The fnite-element method is used to simulate the electrical characteristics of digital cores in order to study the relationship between the conductivity of core saturated with brine (C0) and the brine conductivity (Cw). The infuence of clay mineral type, content and porosity on core electrical characteristics is taken into account. The results show that the additional conductivity is related to the clay minerals, and montmorillonite has the highest cation exchange capacity, resulting in the largest additional conductivity. The increase in clay content in cores increases the conductivity of core C0. At the same time, clay that flls pores decreases the porosity and causes the decrease in C0. These are two opposing factors of conductivity that coexist in clay-bearing sandstone.
EN
To explore the tectonic framework and features of stratigraphic distribution in the Tuolai Sag, Yin-E Basin, a 47-km-long magnetotelluric (MT) sounding measurement was performed around Well MAZD1 in the sag. During feld data acquisition, a remote reference technique was used to ensure data quality, with apparent resistivity and phase curves of all measuring points obtained using the Fourier transform, power spectrum selection, robust estimation and other methods. After MT data processing, dimensionality analysis and the degree of two-dimensional deviation indicated that the study area had the dimensionality needed for two-dimensional inversion. The major electrical axis in the sag was determined, using a multipoint–multifrequency point statistical imaging technique, to be in the WNW direction. Within the constraints of the resistivity log data for Well MAZD1, inversion results for TE and TM models were compared, after which the TM model, which corresponded well to geological conditions, was selected for conducting the nonlinear conjugate gradient method inversion and a reliable resistivity model was fnally obtained. Based on regional petrophysical properties, resistivity logging, and near-well bathymetric data, the electrical characteristics of diferent formations within the sag were obtained and a set of low-resistance clastic rock identifed in the lower Carboniferous strata. Based on an integrated analysis of the regional surface geology, tectonic setting, and depositional environment, and within the constraints of gravity to ft with electrical structure, a tectonic framework of two subsags sandwiched by an uplift is proposed for the Tuolai Sag. The scale of the northern subsag is large, with development of pre-Carboniferous nappe as well as of Carboniferous–Permian strata within the lower part of the nappe. The southern subsag is small and flled mainly with Carboniferous–Permian strata.
PL
Z uwagi na wysokie własności użytkowe, a przede wszystkim wysoką podatność na obróbkę skrawaniem, elementy wykonane ze stopu aluminium serii 2XXX znajdują szerokie zastosowanie w wielu gałęziach współczesnego przemysłu. Tradycyjna technologia ich wytwarzania bazuje na procesie odlewania wielkogabarytowych wlewków oraz następującego po nim procesie wyciskania. W artykule zaprezentowano wyniki badań nad alternatywną metodą ich wytwarzania, a więc procesem ciągłego odlewania profili okrągłych o średnicy 40 mm. W dalszej części przedstawiono analizę ich własności mechanicznych, elektrycznych oraz składu chemicznego przeprowadzonych dla odlewów w gat. EN AW-2007.
EN
Elements manufactured from aluminum alloys series 2XXX are widely used in many branches of modern industry due to their high functional properties and high susceptibility to machining. Traditionally the production of such elements is based on the casting process of large-sized ingots and their subsequent extrusion process. This article presents the research results of the alternative method of their manufacturing which is the process of continuous casting of round profiles with a diameter of 40mm. The article includes the analysis of mechanical, electrical and chemical properties of the EN AW-2007 alloy castings.
13
Content available remote Właściwości strukturalne, optyczne i elektryczne TiO2 modyfikowanego Fe2O3
PL
Celem pracy było określenie własności strukturalnych, elektrycznych i optycznych TiO2 modyfikowanego Fe2O3. Materiały TiO2-Fe2O3 syntezowano metodą zol-żel w zakresie (0-2)% mol. Fe2O3. Badania dyfrakcji promieniowania rentgenowskiego XRD wskazują, że niedomieszkowany TiO2 oraz materiały o zawartości do 0,25% mol. Fe2O3 krystalizują w strukturze rutylu. Przewodnictwo elektryczne mierzono w funkcji składu oraz temperatury (425-700 °C). Położenie i kształt krawędzi absorpcji podstawowej zależy od koncentracji domieszki. Własności strukturalne i elektryczne materiałów potwierdzają zakres tworzenia roztworów stałych.
EN
The aim of this work was to determine the structural, electrical and optical properties of the TiO2 modified with Fe2O3. Fe2O3-TiO2 materials were synthetized by the sol-gel method in the range 0-2 mol% Fe2O3. XRD X-ray diffraction studies indicate that undoped TiO2 and materials with a content of up to 0.25 mol% Fe2O3 crystallize in the rutile structure. Electrical conductivity was measured as a function of composition and temperature (425-700 °C). The location and shape of the primary absorption edge depends on the concentration of the admixture. Structural and electrical properties of materials confirm the range of solid solution formation.
EN
In this paper, the influence of structural and microstructural properties on the properties of electric transport is presented. Composite samples of BaCe0.7Zr0.2Y0.1O3–δ (BCZY) and Li2O:NiO:ZnO (LNZ) with various amount of polyvinyl alcohol (PVA) have been prepared by solid-state reaction route. The porosity caused by the addition of PVA changed the level of total conductivity from 5.8∙10-2 S•cm-1 to 9.5∙10-4 S•cm-1 at 800 °C in dry air. In the humidified atmosphere, the overall conductivities of selected composites were different than measured in dry air what may be related to the surface effects in proton conducting BaZrO3. The influence of porosity on the electrical properties of composites has been analyzed and discussed showing its detrimental nature.
PL
W artykule przedstawiono wpływ właściwości strukturalnych i mikrostrukturalnych na właściwości transportu elektrycznego. Próbki kompozytowe BaCe0,7Zr0,2Y0,1O3-δ (BCZY) i Li2O:NiO:ZnO (LNZ) z różną ilością polialkoholu winylowego (PVA) przygotowano drogą reakcji w fazie stałej. Porowatość spowodowana dodaniem PVA zmieniła poziom całkowitej przewodności z 5,8∙10-2 S∙cm-1 na 9,5∙10-4 S∙cm-1 w temperaturze 800 °C w suchym powietrzu. W wilgotnej atmosferze całkowita przewodność elektryczna wybranych kompozytów była inna niż zmierzona w suchym powietrzu, co może być związane z efektami powierzchniowymi w protonowo przewodzącym BaZrO3. Analizowano wpływ porowatości na właściwości elektryczne kompozytów i dyskutowano o jej szkodliwym charakterze.
EN
A simple and effective hydrothermal synthesis of spherical α-Ni(OH) )2 particles and α-Ni(OH)2/carbon composites was proposed. The mechanism of ultrafine α-Ni(OH) )2 phase forming and correlations between synthesis conditions, morphology, electrical conductivity were analyzed. It was found that carbon nanoparticles form an electric conductive cover on nickel hydroxide microparticles during synthesis which increases overall electronic conductivity of the composite material. α-Ni(OH)2 and α-Ni(OH) )2/C samples were tested as electrodes for hybrid supercapacitors. It was found that carbon coverings stabilize α-Ni(OH) )2 phase in the alkaline medium. The comparison of the influence of laser irradiation and ultrasonic treatment on the electrochemical performance of the obtained materials was made.
EN
In this article, we report the synthesis and characterization of silver dispersed poly(m-toluidine-co-2-bromoaniline) copolymer synthesized by chemical oxidative polymerization method. The synthesized copolymer composites were subjected to different analytical characterization methods, such as FT-IR, UV, XRD, SEM, photoluminescence and electrical conductivity studies. All the polymer samples are found to be soluble in common organic solvents. UV absorption spectra show a red shift when silver nanoparticles are dispersed in the copolymer. The characteristic peaks observed in FT-IR spectra confirm the formation of the copolymer. XRD pattern reveals the crystalline nature of the copolymer composites and sharp peaks in the spectra confirm the presence of silver particles. The silver nanoparticles change the surface morphology in the form of perfect encapsulation. The electrical conductivity of the polymer composites is found to vary from 10-4 S/cm to 10-6 S/cm. PL study reveals the charge transfer between the copolymer and the silver particles.
17
Content available remote Na styku miedzi i grafenu
PL
W artykule przedstawiono zalety i ograniczenia miedzianych przewodów elektrycznych oraz korzyści, wynikające z ich powlekania grafenem. Opisano metody wytwarzania powłok grafenowych na przewodach miedzianych, ze szczególnym uwzględnieniem metody CVD. Ponadto, zaprezentowano założenia projektu „Produkcja warstw grafenowych na przewodnikach miedzianych do zastosowań elektronicznych” (GLC-Connect), finansowanego z programu POIR. W ramach tego projektu zaplanowano opracowanie i budowę dwóch systemów do powlekania grafenem drutu miedzianego i ścieżek elektronicznych metodą CVD.
EN
The article presents the advantages and limitations of copper electric wires as well as the benefits of coating them with graphene. Methods of producing graphene coatings on copper wires with particular emphasis on the CVD method have been described. The project “Manufacturing of graphene layers on copper connections for electronics applications” (GLC-Connect) financed from the SG OP program was generally presented as well. During the project two systems for graphene coating copper wire and electronic paths using CVD method will be created.
EN
The article presents a practical approach in the application of the eddy current method in cases outside the scope and recommendations of EN/ISO 17643: 2015 [1] regarding the testing of eddy currents of welded joints. This standard does not explicitly limit the scope of application to specific materials and welding methods, but gives e.g. recommendations regarding calibration standards, probe construction and test parameters. Such a situation may cause misunderstanding and a number of wrong decisions affecting the result of the examination. The article gives several examples of eddy current testing of welded joints where a completely new approach was required that went far beyond the aforementioned standard, e.g. testing of aluminum welds, duplex steel, metallic coatings, and electron beam welding.
PL
W artykule zaprezentowane jest praktyczne podejście w zastosowaniu metody prądów wirowych w przypadkach wykraczających poza zakres i zalecenia normy EN ISO 17643: 2015[1] dotyczącej badania prądami wirowymi połączeń spawanych. Norma ta nie ogranicza wyraźnie zakresu stosowania do konkretnych materiałów i metod spawania, natomiast podaje np. zalecenia dotyczące wzorców kalibracyjnych, budowy sond i parametrów badania. Sytuacja taka może powodować niezrozumienie i szereg błędnych decyzji wpływających na wynik badania. W artykule podano kilka przykładów badania prądami wirowymi połączeń spawanych, gdzie wymagane było zupełnie nowe podejście wykraczające daleko poza wspomnianą normę jak np. badanie spoin stali duplex, aluminium, badania poprzez powłoki metaliczne czy np. spawanie wiązką elektronów.
EN
Cu-CNT composites were fabricated by a flake powder metallurgy method, and their microhardness, electrical conductivity, frictional and wear properties were investigated. Homogenous distribution of CNTs in fine-grained Cu matrix was obtained using this process. Microhardness increased with the addition of CNT vol% up to 8% to the Cu matrix, while the conductivity decreased to 79.2 IACS %. Results showed that CNTs play a major role in improving wear resistance by forming a CNT-rich film that acts as a solid lubricant layer. In the synthesized composites, Cu- 4 vol% CNT composite exhibited the best wear and friction properties. The dominant wear mechanisms for the Cu-CNT composites were plastic deformation, abrasion, and flake formation-spalling. Also, a newly modified correlation was proposed for the theoretical calculation of the friction coefficient of Cu-CNT composites consisting agglomerated CNTs.
EN
This paper contains the results of electrical conductivity and tribological properties tests of technically pure titanium, which was irradiated with xenon ions with energy 168 MeV with doses of 1÷5×10¹ Xe/cm². They were presented a results of electrical conductivity, results of GXRD analysis and the results of friction coefficient and tribological wear measurements.
PL
Niniejsza praca zawiera wyniki badań przewodności elektrycznej oraz właściwości tribologicznych technicznie czystego tytanu, który został napromieniowany jonami ksenonu z energią 168 MeV z dozami 1÷5×10¹ Xew/cm². Przedstawione zostały pomiary przewodności elektrycznej, wyniki analizy GXRD oraz wyniki pomiaru współczynnika tarcia oraz zużycia tribologicznego.
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