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Wyniki wyszukiwania dla: FAST IMPEDANCE MEASUREMENTS
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A Compact Basis for Reliable Fast Frequency Sweep via the Reduced-Basis Method
PublikacjaA reliable reduced-order model (ROM) for fast frequency sweep in time-harmonic Maxwell’s equations by means of the reduced-basis method is detailed. Taking frequency as a parameter, the electromagnetic field in microwave circuits does not arbitrarily vary as frequency changes, but evolves on a very low-dimensional manifold. Approximating this low-dimensional manifold by a low dimension subspace, namely, reduced-basis space, gives...
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Measurements of flicker noise in supercapacitor cells
PublikacjaFlicker noise (1/f-like noise) is often used to assess the quality of various materials and devices. This phenomenon has been observed in different electrochemical devices or reactions (e.g., smart windows, pitting corrosion events). In our exploratory studies we consider how to measure and utilize 1/f noise for the quality assessment of supercapacitors. This task requires special attention because of enormous capacitance of the...
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Degradation of reference tyres used for CPX measurements
PublikacjaMeasurements of tyre/road noise using the Close Proximity Method are based on reference tyres that are described in ISO/TS 11819-3. The standard specifies two tyres, namely "P1" and "H1" that should be used during measurements. To be used for measurements each tyre must fulfill certain conditions that are listed in the standard. The conditions are related to the tread pattern depth and rubber hardness. During experiments performed...
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A fast technique for diplexer design
Publikacjaw artykule zaprezentowano nową metodę projektowanie mikrofalowych diplekserów. metoda bazuje na dokładnej syntezie filtrów kanałowych wykorzystującej modele zastępcze współczynników sprzężeń w celu uzyskania wstępnych wartości wymiarów układu. następnie dokonywana jest pełnofalowa optymalizacja filtrów kanałowych. ostateczne strojenie numeryczne jest ograniczone do tylko jednego elementu.
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Fast collaborative graph exploration
PublikacjaWe study the following scenario of online graph exploration. A team of k agents is initially located at a distinguished vertex r of an undirected graph. At every time step, each agent can traverse an edge of the graph. All vertices have unique identifiers, and upon entering a vertex, an agent obtains the list of identifiers of all its neighbors. We ask how many time steps are required to complete exploration, i.e., to make sure...
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Fast bubble dynamics and sizing
PublikacjaSingle bubble sizing is usually performed by measuring the resonant bubble response using the Dual Frequency Ultrasound Method. However, in practice, the use of millisecond-duration chirp-like waves yields nonlinear distortions of the bubble oscillations. In comparison with the resonant curve obtained under harmonic excitation, it was observed that the bubble dynamic response shifted by up to 20 percent of the resonant frequency...
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Fast Collaborative Graph Exploration
PublikacjaWe study the following scenario of online graph exploration. A team of k agents is initially located at a distinguished vertex r of an undirected graph. At every time step, each agent can traverse an edge of the graph. All vertices have unique identifiers, and upon entering a vertex, an agent obtains the list of identifiers of all its neighbors. We ask how many time steps are required to complete exploration, i.e., to make sure...
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Permeability of sandy soils estimated from particle size distribution and field measurements
PublikacjaAccurate estimation of soil permeability is crucial in many geotechnical applications. Empirical and theoretical equations based on soil particle size distribution (PSD) offer a fast and cheap way for preliminary estimation of permeability in granular soils, however the results obtained from various formulas available in the literature often show significant discrepancies. While several comparative studies on this topic have been...
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Water uptake in protective organic coatings and its reflection in measured coating impedance
PublikacjaWater uptake in commercially available epoxy coating on mild steel using impedance spectroscopy and gravimetry was studied. The water content in the coating was determined using the Brasher-Kingsbury equation and various methods of coating capacitance calculation used in the literature. The obtained results were compared with reference gravimetric data. An overestimation of values obtained from impedance data in relation to gravimetric...
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Application of electrochemical impedance spectroscopy to monitoring discharging process of nickel/metal hydride battery.
PublikacjaThis paper presents the possibility of applying impedance analysis to cell diagnostics. In order to obtain characteristic curves of both electrodes of a NiMH battery simultaneously, a reference electrode was added into the circuit. The authors analysed the cell under three cases, i.e. when its properties are determined only by the state of the positive electrode, only by the state of the negative electrode, or when both electrodes...
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Impedance Measurement and Selection of Electrochemical Equivalent Circuit of a Working PEM Fuel Cell Cathode
PublikacjaThe dynamic impedance analysis of direct methanolfuel cell (DMFC) cathode supplied with pure oxygen is pre-sented. Presented results were obtained during dynamic chang-es of the current density in working fuel cell. Investigation ofthe occurring processes at cathode was carried with dynamicelectrochemical impedance spectroscopy (DEIS). A discussionwas conducted based on the determined correlation parameterχ2. It was shown that...
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Reliability and Validity of Optoelectronic Method for Biophotonical Measurements
PublikacjaReliability and validity of measurements is of utmost importance when assessing measuring capability of instruments developed for research. In order to perform an experiment which is legitimate, used instruments must be both reliable and valid. Reliability estimates the degree of precision of measurement, the extent to which a measurement is internally consistent. Validity is the usefulness of an instrument to perform accurate...
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Impedance monitoring of corrosion degradation of plasma electrolytic oxidation coatings (PEO) on magnesium alloy
PublikacjaImpedance technique based on continuous multisinusoidal current perturbation was used to explain degradation process of plasma electrolytic oxidation coatings (PEO) on magnesium alloy. An obtained impedance spectrum was fitted by electrical equivalent circuit to describe properties of conversion layer on magnesium alloy. Additionally, galvanostatic mode maintained during experiment, with DC current equal to zero, allowed to achieve...
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Automatic system for optical parameters measurements of biological tissues
PublikacjaIn this paper a system allowing execution of automatic measurements of optical parameters of scattering materials in an efficient and accurate manner is proposed and described. The system is designed especially for measurements of biological tissues including phantoms, which closely imitate optical characteristics of real tissue. The system has modular construction and is based on the ISEL system, luminance and color meter and...
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Inequivalence of entanglement, steering, and Bell nonlocality for general measurements
PublikacjaEinstein-Podolsky-Rosen steering is a form of inseparability in quantum theory commonly acknowledged to be intermediate between entanglement and Bell nonlocality. However, this statement has so far only been proven for a restricted class of measurements, namely, projective measurements. Here we prove that entanglement, one-way steering, two-way steering, and nonlocality are genuinely different considering general measurements,...
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The electrochemical impedance spectroscopy studies of the anode material based on polymer and starch derived ceramic for lithium ion batteries
PublikacjaThe anode materials derived of preceramic polymer poly(1,2-dimethylsilazane) (PSN) and starch was study. Commercially available polysilazane (poly(1,2-dimethylsilazane (PSN 2M01 Gelest) was mixed with commercially available starch (POCH Gliwice). The ratio polymer/starch (PSN/starch) was 1/1 or 3/7. The polysialazane/starch blend was cross-linked at 230 ºC for 2 h followed by heating to the final temperature (500 ºC, 700 ºC and...
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Remote Monitoring System for Impedance Spectroscopy using Wireless Sensor Network
PublikacjaThe architecture of a miniaturized impedanceanalyser with wireless communication module for remoteImpedance Spectroscopy (IS) of anticorrosion coatings ondifficult-to-reach objects (e.g. on the steel construction ofthe bridge) is described in this paper. Some practical aspectsof implementation of a Wireless Sensor Network (WSN) arealso discussed. A low scale, middle range, WSN networkcomposed of a Base Station (BS) with a Personal...
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Investigation on accelerated impedance spectrum measurement method with multisine signal stimulation
PublikacjaThe paper presents an investigation on the accelerated impedance spectrum measurement method, oriented at parameter identification of technical objects modelled by a linear equivalent circuit, e.g. anticorrosion coatings.The method is based on multisine signal stimulation of an object and response analysis by triangle window filterbanks.It has several advantages, as compared with conventional point-by-point spectrum measurement....
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Mobile satellite measurements on the Pomeranian Metropolitan Railway
PublikacjaThis paper presents the process of organization and execution of the mobile satellite measurements conducted on the tracks of the Pomeranian Metropolitan Railway before officially entry the line into operation. These measurements allowed for the accurate identification of the actual geometric shape of the line. In the paper the issues of both design and construction phase of this railway line has been described. Moreover, the geodetic...
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Evaluation of Temperature Influence on Electrochemical Processes Occurring in a Lithium-Ion Supercapacitor with the Use of Dynamic Electrochemical Impedance Spectroscopy
PublikacjaIn order to obtain the full impedance characteristics of a lithium-ion capacitor as a function of temperature, the authors proposed the use of dynamic electrochemical impedance spectroscopy. Impedance tests were carried out under wide range of dynamic temperature changes for lithium-ion supercapacitors. Significant differences in electrochemical processes were observed as a result of working temperature. Moreover, the quality of...
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OVERALL SET OF BANDSAW TEETH VERSUS METHODS OF MEASUREMENTS
PublikacjaThis article deals with the impact of the manual methods of measurement on the overall set measurement results. It describes the results of the measurement of bandsaw teeth kerf with the use of a micrometer and a digital calliper. It is commonly known that the cutting process causes the wear of cutting tools. The wear of the cutting edge depends on the cutting conditions as well as on the mechanical properties of the processed...
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Unidirectional DC/DC Converter with Voltage Inverter for Fast Charging of Electric Vehicle Batteries
PublikacjaThe paper proposes the adaptation of the industrial plant’s power network to supply electric vehicle (EV) fast-charging converters (above 300 kW) using renewable energy sources (RESs). A 600 V DC microgrid was used to supply energy from RESs for the needs of variable speed motor drives and charging of EV batteries. It has been shown that it is possible to support the supply of drive voltage frequency converters (VFCs) and charging...
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Mobile satellite measurements in designing and exploitation of rail roads
PublikacjaThe article presents a summary of several years (2009-2015) of studies on the application of mobile satellite Global Navigation Satellite Systems (GNSS) measurements in the field of designing and operation of railways. These studies have been conducted by an interdisciplinary research team from the Gdansk University of Technology and the Gdynia Maritime University. Mobile satellite GNSS measurements are taken during a ride (through...
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Fast Multi-Objective Antenna Design Through Variable-Fidelity EM Simulations
PublikacjaA technique for fast multi-objective antenna optimization is introduced. A kriging interpolation surrogate constructed from sampled coarse-mesh EM simulations is utilized by multi-objective evolutionary algorithm (MOEA) to obtain the initial Pareto front approximation. The surrogate is defined in a subset of the original design space, determined by means of independently optimized individual objectives. Response correction techniques...
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Fault Diagnostics in PEMFC Stacks by Evaluation of Local Performance and Cell Impedance Analysis
PublikacjaStarvation, flooding, and dry‐out phenomena occur in polymer electrolyte membrane fuel cells (PEMFCs), due to heterogeneous local conditions, material inhomogeneity, and uneven flow distribution across the single cell active area and in between the individual cells. The impact of the load level and air feed conditions on the performance was identified for individual single cells within a 10‐cell stack. Analysis of the current density...
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Evaluation of citric acid corrosion inhibition efficiency and passivation kinetics for aluminium alloys in alkaline media by means of dynamic impedance monitoring
PublikacjaA novel approach is proposed for constructing the adsorption isotherm in corrosion studies, based on a well-known interaction between citric acid and aluminium in alkaline electrolytes. Our approach utilizes the instantaneous impedance measurements via Dynamic Electrochemical Impedance Spectroscopy in galvanostatic mode (g-DEIS). Unlike other common tools, g-DEIS delivers exact information about the concentration required for full...
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Generic appearance of objective results in quantum measurements
PublikacjaMeasurement is of central interest in quantum mechanics as it provides the link between the quantum world and the world of everyday experience. One of the features of everyday experience is its robust, objective character, contrasting the delicate nature of quantum systems. Here we analyze in a completely model-independent way the celebrated von Neumann measurement process, using recent techniques of information flow, studied in...
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Solid State Conductivity of Optimized Polypyrrole Coatings on Iron Obtained from Aqueous Sodium Salicylate Solution Determined by Impedance Spectroscopy
PublikacjaIn this work the optimization procedure for corrosion resistance, surface analysis and electrical properties of PPy-Fe electrodes have been examined. Polypyrrole (PPy) film was electrochemically synthesized in a one step process from an aqueous solution of sodium salicylate and pyrrole with certain concentrations, different parameters and type of polymerization...
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The hydrodynamic pressure field of the ship Zodiak, measurements and calculations
PublikacjaThe article presents the results of measurements of the slowly changing hydrodynamic pressure field HPF generated by the movement of the ship, Zodiak, in the Bay of Gdansk. The measurement results have been obtained in the framework of the program of the work in Siramis, under the auspices of the European Defence Administration of the EU, by the research team of the Naval Academy in Gdynia. The measurement results were compared with...
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Fast multi-criterial statistical analysis and design optimization of compact microwave couplers
Publikacja—A rapid statistical analysis and yield estimation of compact microwave couplers involving multiple performance parameters has been presented. The analysis is realized using a fast surrogate model representing appropriate characteristic points of the coupler response. Because of less nonlinear dependence of the characteristic points on the structure geometry (compared to the original response, i.e., S-parameters vs. frequency),...
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The results of the nitrogen adsorption/desorption measurements of CPMD and CPMH
Dane BadawczeThe results of the nitrogen adsorption/desorption measurements of CPMD and CPMH. The adsorption/desorption isothermswere carried out at 77 K using a Quantachrome Autosorb-1C-MS instrument. Sample abbreviations (CPMD, CPMH) are in agreement with the markings used in the linked publication.
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Results of electrical voltage measurements in reactors - part 1
Dane BadawczeResults of electric voltage measurements in six reactors using various plantings. These are the results of the project: Integrated approach 3M (Macrophytes-Microbiome-Modelling) to elucidate mechanisms of bioenergy production and micropollutants transformation in Floating Treatment Wetlands combined with Microbial Fuel Cells.
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New Indoor Positioning Algorithm for Distance Measurements
PublikacjaIn the paper a new indoor positioning algorithm is presented. This algorithm takes into account selected features of radio wave propagation in indoor environment. This results in improvement in accuracy of calculated position estimates. A comparative analysis of this new algorithm with Chan and Foy algorithms was made and described in the paper. This comparative analysis was made with utilization of real radio distance measurements.
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Multifrequency Nanoscale Impedance Microscopy (m-NIM): A novel approach towards detection of selective and subtle modifications on the surface of polycrystalline boron-doped diamond electrodes
PublikacjaIn this paper, we describe the modification of Nanoscale Impedance Microscopy (NIM), namely, a combination of contact-mode atomic force microscopy with local impedance measurements. The postulated approach is based on the application of multifrequency voltage perturbation instead of standard frequency-by-frequency analysis, which among others offers more time-efficient and accurate determination of the resultant impedance spectra...
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Ellipse-fitting algorithm implementation in the impedance measurement system based on DAQ card with FPGA
PublikacjaThe paper presents an implementation of the ellipse-fitting algorithm in the impedance measurement system based on DAQ card equipped with FPGA chip. The method implementation was tested by simulation means as well as experimentally in the designed and presented measurement system. Finally, the limit values of sampling parameters which assures satisfying accuracy were given.
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Designing of Track Axis Alignment with the Use of Satellite Measurements and Particle Swarm Optimization
PublikacjaDesigning of the track’s alignment is a key issue from the point of view of maintaining of proper geometries. The paper presents a design method for sections of railway line located in the horizontal arch. The method is adapted to the technique of mobile satellite measurements. The general principles of this measurement method have been described in the article. A project's solution has been presented using mathematical notation...
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Measurements of no-load and short-circuit parameters of power transformers with taps
Dane Badawcze1) The Laboratory LINTE^2 is a large research infrastructure operated by the Faculty of Electrical and Control Engineering at Gdańsk University of Technology, to be found in Gdańsk, Poland (54.3690 N, 18.6130 E).
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A new approach to a fast and accurate design of microwave circuits with complex topologies
PublikacjaA robust simulation-driven design methodology of microwave circuits with complex topologies has been presented. The general method elaborated is suitable for a wide class of N-port unconventional microwave circuits constructed as a deviation from classic design solutions. The key idea of the approach proposed lies in an iterative redesign of a conventional circuit by a sequential modification and optimisation of its atomic building...
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Diagnostics of induction motor bearings - possibility of measurements
PublikacjaIn induction motors damage in the elements of electromagnetic system, for example in the wiring of stator, rotor or in the magnetic circuit can appear as well as damage of mechanical parts (bearings, rotor, shaft). Bearing diagnostics is so important in supervision of motor condition, because extensive research shows that the bearings arethe elements most susceptible to damage. This paper presents the research which the author...
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Fast synthesis of coupled-resonator filters.
PublikacjaZaproponowana została nowa, szybko zbieżna technika syntezy macierzy sprzężneń filtrów wykorzystujących rezonatory sprzężone. Metoda jest sformułowana jako nieliniowy problem najmniejszych kwadratów, optarty o zera i bieguny zwarciowej impedancji wejsciowej i wyjściowej oraz wartości własnych macierzy sprzężeń i jej podmacierzy.
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Au nanostructures coated with a ultrathin film of Al2O3 - measurements and FDTD simulations
Dane BadawczeGold plasmonic platforms have been coated with an ultra-thin films of aluminium oxide. Optical measurements, showing the influence of the thickness of Al2O3 on plasmon resonance position. The observed red-shift of the resonance location with the increase of the thickness of the Al2O3 film, can be explained by the change in the dielectric function of...
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3D Acoustic Field Intensity Probe Design and Measurements
PublikacjaThe aim of this paper is two-fold. First, some basic notions on acoustic field intensity and its measurement are shortly recalled. Then, the equipment and the measurement procedure used in the sound intensity in the performed research study are described. The second goal is to present details of the design of the engineered 3D intensity probe, as well as the algorithms developed and applied for that purpose. Results of the intensity...
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A 3D-FEM mesh technique for fast analysis of waveguide problems containing rotatable tuning elements
PublikacjaIn this paper a meshing technique for 3D Finite Element Method is presented. It allows for fast analysis and optimization of the waveguide structures, which contain rotatable tuning elements. In the proposed procedure a thin layer of varying cylindrical mesh buffer is introduced in order to reuse unchanged mesh and FEM matrices in the rest of the domain.
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Application of an Electronic Nose Instrument to Fast Classification of Polish Honey Types
PublikacjaThe paper presents practical utilization of an electronic nose prototype, based on the FIGARO semiconductor sensors, in fast classification of Polish honey types—acacia flower, linden flower, rape, buckwheat and honeydew ones. A set of thermostating modules of the prototype provided gradient temperature characteristics of barbotage-prepared gas mixtures and stable measurement conditions. Three chemometric data analysis methods...
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Fast geometry scaling of miniaturized microwave couplers with power split correction
PublikacjaRedesigning a microwave circuit for various operating conditions is a practically important yet challenging problem. The purpose of this article is development and presentation of a technique for fast geometry scaling of miniaturized microwave couplers with respect to operating frequency. Our approach exploits an inverse surrogate model constructed using several reference designs that are optimized for a set of operating frequencies...
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Computer support of analysis optical spectra measurements
PublikacjaVerification of measurement errors has a big impact on assessment of accuracy of conducted measurements and obtained results. In many cases computer simulation results are compared with measurement results in order to evaluate measurement errors. The purpose of our research was to check the accuracy of measurements made with Fabry-Perot interferometer working in the transmission mode. In measurement setup, a 1310 nm superluminescent...
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Computer Support of Analysis of Optical Spectra Measurements
PublikacjaThe verification of measurement errors has a big impact on the assessment of the accuracy of conducted measurements and obtained results. In many cases, computer simulation results are compared with measurement results in order to evaluate measurement errors. The purpose of our research was to check the accuracy of measurements made with a Fabry–Perot interferometer working in the transmission mode. In the measurement setup, a...
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EXHAUST GAS TEMPERATURE MEASUREMENTS IN DIAGNOSTICS OF TURBOCHARGED MARINE INTERNAL COMBUSTION ENGINES PART II DYNAMIC MEASUREMENTS
PublikacjaThe second part of the article describes the technology of marine engine diagnostics making use of dynamic measurements of the exhaust gas temperature. Little-known achievements of Prof. S. Rutkowski of the Naval College in Gdynia (now: Polish Naval Academy) in this area are presented. A novel approach is proposed which consists in the use of the measured exhaust gas temperature dynamics for qualitative and quantitative assessment...
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Linear and nonlinear impedance in iron oxide glasses containing alkaline ions and alkali free
PublikacjaThe linear and nonlinear impedance spectra of oxide glasses were measured in the frequency range of 1 mHz to 1 MHz and in the temperature range of 153K to 483K. Two groups of iron oxide glass samples were prepared, the first one containing alkaline ions and the second one without alkali. In the first group, compositions of glasses were as follows: (in %mol) 50% SiO2 , 25% PbO, 15% Fe2O3 and 15% one of alkaline oxides: Na2O, K2O,...
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Local impedance spectroscopy of membranes
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