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Wyniki wyszukiwania dla: FLOW PATTERN LATTICE-GAS AUTOMATON
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From flow to jamming: Lattice Gas Automaton simulations in granular materials
PublikacjaWe introduce the first extension of a Lattice Gas Automaton (LGA) model to accurately replicate observed emergent phenomena in granular materials with a special focus on previously unexplored jamming transitions by incorporating gravitational effects, energy dissipation in particle collisions, and wall friction. We successfully reproduce flow rate evolution, density wave formation, and jamming transition observed in experiments....
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Application of a cellular automaton to simulations of granular flow in silos
PublikacjaA cellular automaton based on a gas model of hydrodynamics was used to calculate the kinematics of non-cohesive granular materials during confined flow in a mass flow and funnel flow model silo. In the model, collisions of particles were taken into account during granular flow. In addition, a simplified automaton was used wherein granular flow was assumed as an upward propagation of holes through a lattice composed of cells representing...
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Simulations of behaviour of granular bodies using a lattice-gas automaton.
PublikacjaW artykule przedstawiono wyniki numerycznej analizy przepływu materiałów granulowanych podczas 3 różnych problemów: przepływu silosowego, przepływu kanałowego i tworzenia się nasypu. W modelu zaczerpniętym z teorii gazów przyjęto kolizje cząsteczek i dysypację energii. Wyniki porównano z doświadczeniami.
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Structural and physical characterization of NpPt2In7
PublikacjaA new neptunium intermetallic compound, NpPt2In7, has been synthesized in polycrystalline form and characterized by several macroscopic techniques. A Rietveld analysis of its powder x-ray diffraction pattern shows that NpPt2In7 crystallizes in a tetragonal lattice with I4/mmm symmetry and lattice parameters a = 4.58471(3) Å, c = 21.5065(3) Å. Magnetic susceptibility, electrical resistivity, Hall effect, and heat capacity measurements indicate...
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Application of an improved cellular automaton for granular flow.
PublikacjaW artykule omówiono wyniki numeryczne z zastosowaniem ulepszonego aparatu komórkowego do przepływów silosowych materiałów granulowanych. W modelu uwzgledniono zderzenia cząstek i dysypację energii. Wyniki porównano z wynikami badań modelowych.
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Simulations of flow patterns in silos with a cellular automaton - part 2
PublikacjaW artykule przedstawiono wyniki symulacji przepływów silosowych przy zastosowaniu zaawansowanego aparatu komórkowego, w którym uwzględniono kolizje cząstek i dysypację energii. Obliczenia wykonano dla przepływu masowego i kominowego.
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Extraction and evaluation of gas-flow-dependent features from dynamic measurements of gas sensors array
PublikacjaGas analyzers based on gas sensors are the devices which enable recognition of various kinds of volatile compounds. They have continuously been developed and investigated for over three decades, however there are still limitations which slow down the implementation of those devices in many applications. For example, the main drawbacks are the lack of selectivity, sensitivity...
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Fermi-liquid behavior of binary intermetallic compounds Y3 M (M = Co, Ni, Rh, Pd, Ir, Pt)
PublikacjaA series of polycrystalline samples of Y3 M (M = Co, Ni, Rh, Pd, Ir, Pt), intermetallic binary compounds were synthesized by the arc-melting method. Powder x-ray diffraction (pXRD) confirmed the orthorhombic cementite-type crystal structure and allowed for the estimation of the lattice parameters. Physical properties were investigated by means of electrical resistivity and heat capacity measurements between 1.9 K and 300 K. All...
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On design and analysis of flow characteristics of the last stage of gas-steam turbine
PublikacjaResearch regarding blade design and analysis of flow have been conducted for over a century. Meanwhile new concepts and design approaches were created and improved. Advancements in information technologies allowed to introduce computational fluid dynamics (CFD) and computational flow mechanics (CFM). Currently a combination of mentioned methods is used for design of turbine blades. These methods enabled us to improve flow efficiency...
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Non-Linear Interaction of Harmonic Waves in a Quasi-Isentropic Flow of Magnetic Gas
PublikacjaThe diversity of wave modes in the magnetic gas gives rise to a wide variety of nonlinear phenomenaassociated with these modes. We focus on the planar fast and slow magnetosound waves in the geometryof a flow where the wave vector forms an arbitrary angleθwith the equilibrium straight magnetic field.Nonlinear distortions of a modulated signal in the magnetic gas are considered and compared to thatin unmagnetised gas. The case of...
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Signals Features Extraction in Radioisotope Liquid-Gas Flow Measurements using Autocorrelation Function
PublikacjaKnowledge of the two-phase flow structure is essential for the proper conduct of industrial processes. Description of liquid-gas flow regimes is possible by using of data analysis in time, frequency, or state-space domain. In this research studies, the autocorrelation function is applied for analysis of signals obtained for liquid-gas flow by use gamma-ray absorption. The experiments were carried out on the laboratory hydraulic...
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Analysis and interpretation of radiometric signals in a liquid-gas bubble flow
PublikacjaThe article presents the analysis of signals from a radiometric system consisting of two scintillation probes and two gamma radiation sealed sources. Calculations and interpretation were carried out for the bubble flow of the water-air mixture in the horizontal pipeline. The analysis of the obtained signals was done in time and frequency domain. In the frequency domain, a range of usable frequencies was identified, which were associated...
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Radioisotope measurements of the liquid-gas flow in the horizontal pipeline using phase method
PublikacjaThe paper presents application of the gamma-absorption method to a two-phase liquid-gas flow investigation in a horizontal pipeline. The water-air mixture was examined by a set of two Am-241 radioactive sources and two NaI(Tl) scintillation probes. For analysis of the electrical signals obtained from detectors the cross-spectral density function (CSDF) was applied. Results of the gas phase average velocity measurements for CSDF...
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Research on flue gas flow measurement and modelling in the moving grate biomass boiler
PublikacjaThe aim of this research was to determine the nature of gas flow in a grate boiler model by the method of Particle Image Velocimetry (PIV) and CFD. The paper presents the comparison of the PIV results with numerical simulations made in the environment of ANSYS Fluent. The main goal of the experiment was to describe the phenomena occurring on the grate. Methodology of modelling solid fuel combustion on the moving grate was proposed...
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Nonlinear Interaction of Modes in a Planar Flow of a Gas with Viscous and Thermal Attenuation
PublikacjaThe nonlinear interaction of wave and non-wave modes in a gas planar flow are considered. Attention is mainly paid to the case when one sound mode is dominant and excites the counter-propagating sound mode and the entropy mode. The modes are determined by links between perturbations of pressure, density, and fluid velocity. This definition follows from the linear conservation equations in the differential form and thermodynamic...
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Dariusz Mikielewicz prof. dr hab. inż.
OsobyDariusz Mikielewicz – urodził się 6 lutego 1967 roku w Gdańsku, w 1985r. zdał pomyślnie egzaminy wstępne na Wydział Budowy Maszyn Politechniki Gdańskiej, który ukończył z wynikiem bardzo dobrym w 1990 roku na specjalności Maszyny i Urządzenia Energetyczne. Zainteresowania pracą naukową skłoniły go do podjęcia badań na University of Manchester na wydziale mechanicznym i energetyki jądrowej (Mechanical and Nuclear Engineering Department)...
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OBTAINING FLUID FLOW PATTERN FOR TURBINE STAGE WITH NEURAL MODEL.
PublikacjaIn the paper possibility of applying neural model to obtaining patterns of proper operation for fluid flow in turbine stage for fluid-flow diagnostics is discussed. Main differences between Computational Fluid Dynamics (CFD) solvers and neural model is given, also limitations and advantages of both are considered. Time of calculations of both methods was given, also possibilities of shortening that time with preserving the accuracy...
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Signal Processing in the Investigation of Two-phase Liquid-gas Flow by Gamma-ray Absorption
Publikacjan this paper, the use of the gamma-absorption method applied in the investigation of the two-phase liquid-gas flow in the pipeline is described. An example of its application to the air transported by water in a horizontal pipeline is evaluated. In the measurements, Am-241 radioactive sources and probes with Nal (Tl) scintillation crystals have been used. The signals from the radiometric set were used to determine the velocity...
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EVALUATION OF LIQUID-GAS FLOW IN PIPELINE USING GAMMA-RAY ABSORPTION TECHNIQUE AND ADVANCED SIGNAL PROCESSING
PublikacjaLiquid-gas flows in pipelines appear in many industrial processes, e.g. in the nuclear, mining, and oil industry. The gamma-absorption technique is one of the methods that can be successfully applied to study such flows. This paper presents the use of thegamma-absorption method to determine the water-air flow parameters in a horizontal pipeline. Three flow types were studied in this work: plug, transitional plug-bubble,...
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Computational Fluid Dynamics Simulation of Gas–Liquid Multiphase Flow in T-junction for CO2 Separation
PublikacjaThe article presents the results of a computational fluid dynamics (CFD) analysis of gas-liquid multiphase flow. The simulation was conducted using CFD code and the Euler–Euler approach. The presented study relates to the non–reactive, steady-state, turbulent flow of water and carbon dioxide mixture in a 3D pipe. Separation phenomenon between phases is observed. The solution was obtained using a mixture model. Different values...
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Experimental study of flow pattern and heat transfer during steam drying of wood
PublikacjaBadania wysokotemperaturowego suszenia drewna zostały zainspirowane koniecznością instensyfikacji wymiany ciepła i masy na potrzeby przemysłu drzewnego, a w szczególności meblarskiego, w zakresie doskonalenia metod suszenia drewna, modelowania intensyfikacji wymiany ciepła i masy w elementach suszonych, opracowania ekologicznych i energooszczędnych systemów suszarniczych, ochrony środowiska związanej z racjonalnym zużyciem energii,...
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Investigation of Liquid–Gas Flow in a Horizontal Pipeline Using Gamma-Ray Technique and Modified Cross-Correlation
PublikacjaThis article presents the application of the radioisotope absorption method in the study of two-phase water–air flow in a horizontal pipe. The measurement principle and the test stand are briefly described. The main part of the article presents the signal analysis methods applied to data obtained from scintillation detectors. Because these signals are mostly stochastic waveforms, they were analyzed statistically using the cross-correlation...
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Decahedral-shaped anatase titania photocatalyst particles: Synthesis in a newly developed coaxial-flow gas-phase reactor
PublikacjaDecahedral-shaped anatase particles (DAPs) were prepared by a gas-phase process consisting of titanium(IV) chloride oxidation. The use of a coaxial-flow gas-phase reactor resulted in high reaction yield (ca. 70%) and good reproducibility of DAPs production. The influence of controlled and resultant preparation parameters on the process course and on DAPs properties (such as specific surface area, particle size and particle morphology)...
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Experimental investigation of the flow pattern and wall pressure distribution in a silo with double-cone insert
PublikacjaArtykuł opisuje przeprowadzone badania przepływów silosowych i naporu materiałów sypkich podczas napełniania i opróżniania silosu o średnicy 2.5 m wyposażonego we wkładkę "podwójny stożek". Badania przeprowadzane były w Instytucie Badawczym Tel-Tek w Norwegii. Materiałem użytym był suchy piasek. Napór na ścianę mierzony był bezpośrednio za pomocą 10 czujników wbudowanych w ścianę. Badania eksperymentalne pokazały duży wpływ wkładki...
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The influence of a cone-in-cone insert on flow pattern and wall pressure in a full-scale silo
PublikacjaArtykuł opisuje przeprowadzone badania przepływów silosowych i naporu materiałów sypkich podczas napełniania i opróżniania silosu o średnicy 2.5 m wyposażonego we wkładkę "stożek w stożku''. Badania przeprowadzane były w Instytucie Badawczym Tel-Tek w Norwegii. Materiałem użytym był suchy piasek. Napór na ścianę mierzony był bezpośrednio za pomocą 10 czujników wbudowanych w ścianę. Badania eksperymentalne pokazały duży wpływ wkładki...
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Physical and numerical modelling of flow pattern and combustion process in pulverized fuel fired boiler.
PublikacjaW pracy przedstawiono źródła powstawania toksycznych związków podczas procesu spalania, metody ich redukcji. Do tego zadania wykorzystano eksperymentalne modelowanie fizyczne i uzupełniono je modelowaniem numerycznym. Obie metody, techniki modelowania miały na celu optymalizację procesu spalania.Wyniki obliczeń numerycznych porównano z pomiarami.
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Influence of gas parameters alteration on the form of gas-flow-impact appearing in long transportation pipelines
PublikacjaPrzy szybkich zamknięciach przepływu w długich liniach transportowych gazu, obserwuje się znaczne przesterowania ciśnienia, towarzyszące zjawiskom udarowym, wywołane zarówno falą uderzeniową jak i odbitą. Głównym czynnikiem wpływającym na postać fali uderzeniowej i jej amplitudy, jest szybkość zamykania zaworu odcinającego określona stałą czasową serwomotoru sterującego zaworem. Ponieważ obserwuje się zmiany właściwości chemicznych...
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Evaluation of the structures size in the liquid-gas flow by gamma-ray absorption
PublikacjaThe rapid development of tomography methods particularly electrical, X and gamma rays allows for a wide range of the information about flow structure. However, all of such methods are quite complicated. At the same time much simpler systems as the measuring system of gamma rays absorption, allows to obtain a all key flow information which describe the two-phase flow. In the article the results of analyzes of radiometric signal...
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COMPARATIVE ANALYSIS OF THE RESULTS OF GAS FLOW IN A LABYRINTH SEAL FOR A NUMERICAL AND THEORETICAL MODEL
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Influence of Gas-Flow Conditions on the Evolution of Thermally Insulating Si3N4 Nano-Felts
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Adoption of the F-statistic of Fisher-Snedecor distribution to analyze importance of impact of modifications of injector opening pressure of a compression ignition engine on specific enthalpy value of exhaust gas flow
PublikacjaThis article analyzes the effect of modifications of injector opening pressure on the operating values of a compression ignition engine, including the temperature of the fumes. A program of experimental investigation is described, considering the available test stand and measurement capabilities. The structure of the test stand on which the experimental measurements were conducted is presented. The method of introducing real modifications...
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Radioisotope measurement of selected parameters of liquid-gas flow using single detector system
PublikacjaTo determine the parameters of two-phase flows using radioisotopes, usually two detectors are used. Knowing the distance between them, the velocity of the dispersed phase is calculated based on time delay estimation. Such a measurement system requires the use of two gamma-ray sealed sources. But in some situations it is also possible to determine velocity of dispersed phase using only one scintillation probe and one gamma-ray source....
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Signals features extraction in radioisotope liquid-gas flow measurements using wavelet analysis
PublikacjaKnowledge of the structure of a flow is significant for the proper conduct of a number of industrial processes. In this case, a description of a two-phase flow regimes is possible by use of the time-series analysis in time, frequency and state-space domain. In this article the Discrete Wavelet Transform (DWT) is applied for analysis of signals obtained for water-air flow using gamma ray absorption. The presented method was illustrated...
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Influence of Analyte Flow Rate on Signal and Response Time of the Amperometric Gas Sensor with Nafion Membrane
PublikacjaW publikacji przedstawiono rezultaty badań nad wpływem zmian objętościowego natężenia przepływu gazu na sygnał i czas odpowiedzi prototypowego czujnika ditlenku siarki z membraną nafionową. Porównywano właściwości czujników różniących się materiałem elektrody pracującej oraz składem roztworu elektrolitu wewnętrznego. Zastosowano elektrody pracujące wykonane z napylonych próżniowo na powierzchnię membrany nafionowej złota i platyny....
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Application of gas flow headspace liquid phase micro extraction coupled with gas chromatography-mass spectrometry for determination of 4-methylimidazole in food samples employing experimental design optimization
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Some coatings of high cavitation resistance produced by CO2 laser beam. XIV International Symposium on Gas Flow, Chemical Lasers and High Power Lasers.
PublikacjaPrzedstawiono wyniki badań odporności kawitacyjnej stali 2H13, 45 i żelaza Armco po laserowym stopowaniu ich powierzchni różnymi kompozycjami proszków Co, Mo, Ni, Mn i Cr, Ti. Wykazano różne własności kawitacyjne otrzymanych warstw w zależności od otrzymanej mikrostruktury.
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Application of the F-statistic of the Fisher-Snedecor distribution to analyze the significance of the effect of changes in the compression ratio of a diesel engine on the value of the specific enthalpy of the exhaust gas flow
PublikacjaThe paper discusses the impact of changes in the compression ratio on the operating parameters of a diesel engine, e.g. on the temperature of exhaust gases. It presents the construction of the laboratory test stand, on which experimental measurements were realized. It is characterized how the actual changes of the compression ratio were introduced to the existing engine. The program of experimental investigations taking into account...
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Cavitation resistance of OH18N9 steel alloyed with vaidus amount of TiC or Mn by means of laser beam. XIV International Symposium on Gas Flow, Chemical Lasers and High Power Lasers.
PublikacjaPrzedstawiono badania odporności kawitacyjnej stali OH18N9T po laserowym stopowaniu jej powierzchni węglikiem TiC oraz manganem. Wykazano, że wzbogacenie obrabianej stali manganem powoduje przemiany fazowe pod wpływem działania obciążeń kawitacyjnych, co przyczynia się do wzrostu odporności kawitacyjnej. Wzmacnianie stali węglikiem TiC powoduje natomiast zanik zdolności stali do wzmacniania odkształceniowego.
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Fluid Mechanics, L/L/E, DaPE, sem. 04, summer 21/22 (PG_00050282)
Kursy OnlineLECTURES Introduction and basic definitions. Properties of fluids. Models of fluids. Fluids in equilibrium. Determination of hydrostatic forces. Archimedes" law. Methods of fluid flow description. General motion of fluid. Deformation of fluid element. Vortex motion of fluid. Principles of conservation of mass, momentum and energy. Balance of entropy. Navier-Stokes equation. Bernoulli equation. Similarity of flow phenomena. Potential...
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Flow Maps and Flow Patterns of R1233zd(E) in a Circular Minichannel at Low, Medium and High Values of Saturation Pressure
PublikacjaThere is a gap in knowledge regarding the flow pattern of low-boiling working fluids in the range of high saturation temperatures (above 120°C) and medium and high reduced pressures (0.5-0.9). Data are present in the literature for similar values of reduced pressures, but for lower values of saturation temperature. This is due to the existing refrigeration applications of these working fluids. At high values of reduced pressure,...
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Methane (CH4) calibration set of FTIR spectra
Dane BadawczeThe calibration spectra for CH4 concentration calibration were supplied with this dataset
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Carbon (II) oxide (CO) calibration set of FTIR spectra
Dane BadawczeThe calibration spectra for CO concentration calibration were supplied with this dataset
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Carbon dioxide (CO2) calibration set of FTIR spectra
Dane BadawczeThe calibration spectra for CO2 concentration calibration were supplied with this dataset
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Fundamentals of Steam and Gas Turbines OASIV
Kursy OnlineApplication of turbines in industry and sea power plants. Basic thermodynamics and fluid flow mechanics in turbomachinery. Steam turbine power cycle and plants. Gas turbine power cycle and plants. Turbine blading systems operation.
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Identification of volatile compounds based on the electrocatalytic gas sensor responses
PublikacjaMeasured response in case of electrocatalytic gas sensors is in form of a voltamperometric characteristic. Current-voltage (I-V) response shape depends on the gas type and its concentration. Such response contains significantly more information comparing with typical electrochemical sensors, but is quite difficult to analyze. When I-V curve contains current peaks, position of such peaks can be used...
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Low temperature electrical conductivity of the SrFeO3-d pellet
Dane BadawczeThis dataset contains results of low temperature electrical conductivity measurements of dense SrFeO3-d (SFO) pellet. DC electrical conductivity measurements of SFO were performed by the Van der Pauw method between 400 °C and room temperature with 20 °C step. Studies were performed at Synthetic Air flow under humidified (~4 vol%) gas flow rate of 40...
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Low temperature electrical conductivity of the SrTi0.65Fe0.35O3-d pellet
Dane BadawczeThis dataset contains results of low temperature electrical conductivity measurements of dense SrTi0.65Fe0.35O3-d (STF35) pellet. DC electrical conductivity measurements of STF35 were performed by the Van der Pauw method between 400 °C and room temperature with 20 °C step. Studies were performed at Synthetic Air flow under humidified (~4 vol%) gas...
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Low temperature electrical conductivity of the SrTi0.30Fe0.70O3-d pellet
Dane BadawczeThis dataset contains results of low temperature electrical conductivity measurements of dense SrTi0.30Fe0.70O3-d (STF70) pellet. DC electrical conductivity measurements of STF70 were performed by the Van der Pauw method between 400 °C and room temperature with 20 °C step. Studies were performed at Synthetic Air flow under humidified (~4 vol%) gas...
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Low temperature electrical conductivity of the SrTi0.50Fe0.50O3-d pellet
Dane BadawczeThis dataset contains results of low temperature electrical conductivity measurements of dense SrTi0.50Fe0.50O3-d (STF50) pellet. DC electrical conductivity measurements of STF50 were performed by the Van der Pauw method between 400 °C and room temperature with 20 °C step. Studies were performed at Synthetic Air flow under humidified (~4 vol%) gas...
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Low temperature electrical conductivity of the SrTi0.10Fe0.90O3-d pellet
Dane BadawczeThis dataset contains results of low temperature electrical conductivity measurements of dense SrTi0.10Fe0.90O3-d (STF90) pellet. DC electrical conductivity measurements of STF90 were performed by the Van der Pauw method between 400 °C and room temperature with 20 °C step. Studies were performed at Synthetic Air flow under humidified (~4 vol%) gas...