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Wyniki wyszukiwania dla: fc local impedance
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Usage of concentrated spectrogram for analysis of acoustical signals
PublikacjaA novel precise method of signal analysis in the time-frequency domain is presented. A signal energy distribution is estimated by discard and displacement of energy parts of the classical spectrogram. A channelized instantaneous frequency and a local group delay are used in order to energy replacement. Additionally, newly introduced representations such as: a channelized instantaneous bandwidth and a local group duration are used...
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What Can Be Observed Locally? Round based models for quantum distributed computing
PublikacjaW pracy rozważono zagadnienie lokalności w kontekście informacji kwantowej w obliczeniach rozproszonych. Rozważono dwa kwantowe rozszerzenia modelu LOCAL Liniala, otrzymane poprzez: (1) inicjalizację systemu w kwantowym stanie splątanym, (2) zastosowanie kwantowych kanałów komunikacyjnych. Dla obydwu typów rozszerzeń zaproponowano przykłady problemów, których złożoność rundowa ulega redukcji w porównaniu do oryginalnego modelu...
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Underwater Welding of Duplex Stainless Steel
PublikacjaThe present work was conducted to assess the weldability of duplex stainless steel at underwater conditions. Interest of underwater welding of this steel grade is connected with necessity of preparing welding repair technologies for subsea pipelines widely used in offshore oil and gas industry. The GMA local cavity welding method was used in the investigations. Welded beads were performed underwater at 0.5 m depth and in the air....
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A novel method of time-frequency analysis: an essential spectrogram
PublikacjaA novel precise method of time-frequency analysis is presented. In the algorithm, a new energy distribution is estimated by simultaneously discard or displacement of the classical spec- trogram energy. A channelized instantaneous frequency and a local group delay are used in order to replacement in the same manner as formulated by Kodera et al. [1, 2]. Additionally, new representations: a channelized instantaneous bandwidth and...
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Agile Methods In Formation of Metropolis Neighbourhood
PublikacjaA study of the zone adjoining the metropolis area of Tricity (Poland) was conducted on the basis of analyses of changes in spatial development, outline planning decisions and local plans of spatial development. Localities placed at several dozen kilometres from strongly urbanized areas do not constitute metropolis outskirts. The vicinity of large urban centres is an obstacle to the development of localities as self-sufficient units...
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Seasonal and spatial differences in metal and metalloid concentrations in the snow cover of Hansbreen, Svalbard
PublikacjaMetals and metalloids in snow on glaciers, depending on the season of deposition, may come from various sources: local rock dust (erosion of the geological substratum), marine aerosol, local human activity (e.g. fuel combustion, waste incineration) and long-range atmospheric transport. Hansbreen glacier, located close to the Polish Polar Station in Svalbard, is a perfect site to study metals and metalloids: it has complex geological...
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Ekspatrianta versus lokalny menedżer, czyli kto powinien kierować filią zagraniczną? = Expatriate versus host country manager - who should run a foreign subsidiary?
PublikacjaThere is ample literature on expatriate management that presents a parent company's point of view on this issue. A consideration of subsidiary management from the local perspective is missing. Relationships with foreigners (including expatriates) are cross-cultural interactions and their effectiveness is affected by cultural factors. Therefore, in this article there are questions that need to be answered:1. What role does an expatriate...
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On the crack front curvature in bonded joints
PublikacjaStandard tests of adhesively bonded specimens are likely to produce heterogeneous stress distribution along the crack front and its vicinity. High separation rate mode I dominated fracture test is performed.Observation of post mortem fractured surfaces with an optical microscope reveals characteristic features of mixed mode I/III fracture near the sides of the specimen but not in the middle. At first, finite elements calculations...
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Urban Vegetation in Air Quality Management: A Review and Policy Framework
PublikacjaRecent episodes of high air pollution concentration levels in many Polish cities indicate the urgent need for policy change and for the integration of various aspects of urban development into a common platform for local air quality management. In this article, the focus was placed on the prospects of improving urban air quality through proper design and protection of vegetation systems within local spatial planning strategies....
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Quasi-Global Optimization of Antenna Structures Using Principal Components and Affine Subspace-Spanned Surrogates
PublikacjaParametric optimization is a mandatory step in the design of contemporary antenna structures. Conceptual development can only provide rough initial designs that have to be further tuned, often extensively. Given the topological complexity of modern antennas, the design closure necessarily involves full-wave electromagnetic (EM) simulations and—in many cases—global search procedures. Both factors make antenna optimization a computationally...
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A novel concept for tissue-metal detection and differentiation using an inductive proximity sensor
PublikacjaIn this paper a novel application of inductive proximity sensors for detection of living tissue by means of measurements of the coil impedance changes at different frequencies is described. The mathematical analyses utilizing Bessel function estimation include detected object size and its distance from a sensor. The main aim of this study is to prove the possibility of distinguishing between metal objects and living tissues. The...
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Domain Reduction in Hybrid Technique for Electromagnetic Wave Scattering Problems
PublikacjaThis paper proposes a combination of the field matching technique, finite element method and generalized impedance matrix, the main idea of which is to reduce the computational domain by surrounding a scatterer with the smallest convex shape and applying the field matching technique. This approach can be applied for arbitrary shaped scatterers and types of materials and allows for the reduction of the computational domain. In order...
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Hybrid Analysis of Structures Composed of Axially Symmetric Objects
Publikacja— A hybrid method for the scattering problems in shielded and open structures is presented. The procedure is based on the combination of body-of-revolution involving finite-element methods with impedance matrix formulation and the mode-matching technique, which can be utilized for the analysis of structures with axially symmetrical scatterers. In order to confirm the validity and efficiency of the proposed approach, a few examples...
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Tracing of dynamic objects in distributed interactive simulation systems
PublikacjaDistributed interactive simulation systems require integration of several areas of computer science and applied mathematics to enable each individual simulation object to visualize effectively dynamic states of other objects. Objects are unpredictable,i.e., controlled by their local operators, and are remote, i.e., must rely on some transmission media to visualize dynamic scene from their local perspectives. The paper...
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On adaptive selection of estimation bandwidth for analysis of locally stationary multivariate processes
PublikacjaWhen estimating the correlation/spectral structure of a locally stationary process, one should choose the so-called estimation bandwidth, related to the effective width of the local analysis window. The choice should comply with the degree of signal nonstationarity. Too small bandwidth may result in an excessive estimation bias, while too large bandwidth may cause excessive estimation variance. The paper presents a novel method...
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Improved Performance of 1-Ethyl-3-Methylimidazolium Tetrafluoroborate at Steel/HCl Interface by Iodide Ions
PublikacjaThe corrosion and corrosion inhibition of St37 steel in 0.1 M HCl solution by 1-ethyl-3-methylimidazolium tetrafluoroborate (EMITFB) and the effect of addition of KI on the inhibitive performance of EMITFB have been examined by electrochemical [electrochemical impedance spectroscopy, potentiodynamic polarization, and dynamic electrochemical impedance spectroscopy (DEIS)] and surface examination [scanning electron microscope (SEM)...
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Understanding the origin of high corrosion inhibition efficiency of bee products towards aluminium alloys in alkaline environments
PublikacjaVarious bee products were found to be efficient corrosion inhibitors of aluminium in different environments. In particular, bee pollen was found to be highly effective in alkaline electrolytes, yet its highly complex composition and possible synergistic interactions hinder determination of the compounds acting as active corrosion inhibitors. The main purpose of the following work is to investigate the effect of solvents used for...
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A Series-Inclined-Slot-Fed Circularly Polarized Antenna for 5G 28-GHz Applications
PublikacjaThis letter presents the design of a single-point-fed, geometrically simple circularly polarized (CP) antenna for 28 GHz Ka-band applications. The proposed antenna is based on a straight microstrip line printed on one side and coupled with the nearly square patches through a 45-degree inclined V-shape slot aperture on the other side. In order to generate circular polarization, the fundamental radiating mode is degenerated at a...
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A body position influence on ECG derived respiration
PublikacjaAn influence of a human body position on ECG derived respiration (EDR) signal is presented in the paper. Examinations were performed during deep, suspended and normal breathing for eight people in four different body positions. EDR and thoracic impedance signals were compared using correlation and standard deviation coefficients. Obtained results have shown that it is possible to monitor breath activity of people being in different...
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Novel microstrip low-pass filters with fractal defected ground structures
PublikacjaIn this study, three microstrip low-pass filters (LPFs) containing fractal-shaped defected ground structures have been designed and manufactured. To improve the performance of microstrip LPF, cascades of inductively coupled fractal resonators have been applied. Simultaneously, to achieve relatively constant microstrip impedance resulting in essentially low reflection losses, a modification of the strip geometry has been introduced....
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Differential analysis of dynamic immittance spectra
PublikacjaThis work presents a new approach to the analysis of immittance spectrograms of systems characterised by non-stationarity. The possibility of linking the evolution of the immittance response with changes in the parameters describing the system is achieved by introducing a spectrum in differential form. By using the above procedure, it becomes possible to separate elements with a dependence (or lack thereof) from an independent...
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Low-Cost Surrogate Modeling of Miniaturized Microwave Components Using Nested Kriging
PublikacjaIn the paper, a recently reported nested kriging methodology is employed for modeling of miniaturized microwave components. The approach is based on identifying the parameter space region that contains high-quality designs, and, subsequently, rendering the surrogate in this subset. The results obtained for a miniaturized unequal-power-split rat-race coupler and a compact three-section impedance transformer demonstrate reliability...
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Screw displacement pile shaft deformations measured by vibrating wire and fiber optic systems during a static load test
PublikacjaThis paper describes a full scale static load test performed on a 400 mm diameter screw displacement pile equipped with four different strain measuring systems. Three types of vibrating wire strain gauges (VWSG) were used: global - retrievable, local attached to steel pipe and local concrete embedded. The fourth system was distributed fiber optic sensors based on Rayleigh back scattering (DFOS) - three in the pile cross section....
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Seafloor characterisation using multibeam sonar echo signal processing and image analysis
PublikacjaThe authors propose the approach to multibeam seafloor characterisation which relies on the combined, concurrent use of two different techniques of multibeam sonar data processing. The first one is based on constructing the grey-level sonar images of seabed using the echoes received in the consecutive beams. Then, the parameters describing the local region of sonar image, namely, the local standard deviation of a grey level, and...
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Activities of the Astro-geodetic Observatory in Jozefoslaw in the frame of IGS and EUREF
PublikacjaThe Astrogeodetic Observatory of the Institute of Geodesy and Geodetic Astronomy of the Warsaw University of Technology (WUT) in Jozefoslaw was incorporated in 1957. In 1991 it joined the International GPS Service (IGS) and started to operate as a permanent in 1993. Since then the following permanent services have been maintained: GPS observations using Trimble and Turbo Rogue receivers, tidal gravimetric observations with LaCoste&Romberg...
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Urban regeneration in urban functional areas in Poland as an instrument of implementation of the EU Cohesion Policy
PublikacjaThis study examines the role of urban regeneration policies in planning and governance within urban functional areas (UFAs) in Poland, in the context of the EU Cohesion Policy (CP). The empirical part of this study is based on comparing the approaches adopted in two Polish regions: Pomerania and Silesia. We describe the first successes but also the bottlenecks of the process, from negotiations and programming up to the implementation...
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Warunki hydrogeochemiczne i podatność na zanieczyszczenie wód podziemnych w zlewni górnej Raduni
PublikacjaThe paper presents results of long-term studies in the Kashubian Lake district that have been completed with data gathered over the last five years. The purpose of this research was to assess a temporal variability of groundwater chemical composition and to analyze risk of pollutant migration to subsurface water. Investigation indicates local, however, significant anthropogenic influence on a shallow aquifers.The assessment of...
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Entanglement-redistribution boxes
PublikacjaWe establish a framework to study the classical-communication properties of primitive local operations assisted by classical communication which realize various redistributions of entanglement, like, e.g., entanglement swapping. On the one hand, we analyze what local operations and how much classical communication are needed to perform them. On the other hand, we investigate whether and to what extent such primitives can help to...
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An inclination in Thermal Energy Using Nanoparticles with Casson Liquid Past an Expanding Porous Surface
PublikacjaPhysical aspects of inclined MHD nanofluid towards a stretching sheet embedded in a porous medium are visualized. Two types of nanoparticles are used named as copper and alumna dioxide with water as base fluid. Similarity transformations are used to convert the partial differential equations into the set of ordinary differential equation. Closed solutions are found to examine the velocity and the temperature profiles. It is examined...
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A comparative performance assessment of a hydrodynamic journal bearing lubricated with oil and magnetorheological fluid
PublikacjaThis work presents the investigation results of a journal bearing lubricated with magnetorheological fluid that is activated by a local constant magnetic field to vary both the local flow resistance and pressure. The bearing performance is assessed via Finite Element Modelling (FEM) and results are corroborated by experiments. The FEM model uses the Bingham model to describe the fluid film. A dedicated test rig is used to assess...
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Assessment of protective properties of rubber lining in absorbers of flue gas desulphurization systems.
PublikacjaResults of research on degradation of rubber lining which is the main protection of absorbers in flue gas desulphurization (FGD) systems were presented. The power plant where the system operated is lignite-fired. Owing to measurements using electrochemical impedance spectroscopy and gravimetric determination of water content in the lining, the areas of the system which are most exposed to degradation were shown. The results obtained...
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Broadband Modeling of Motor Cable Impact on Common Mode Currents in VFD
PublikacjaExamination of conducted EMI generation and propagation in AC motor drives fed by frequency converter requires to consider parasitic capacitances in converters, motor windings and feeding cables to be taken into account. AC motor winding voltage transients and related common mode currents are significantly correlated with resonance effects occurring in converter's load circuits. Intensity levels of these phenomena depend...
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Motor Cable Influence on the Conducted EMI Emission of the Converter Fed AC Motor Drive. - Vol. 1
PublikacjaInvestigation of conducted electromagnetic interference in AC motor drives fed by pulse width modulated voltage converters requires considering parasitic capacitances in converters, motor windings and feeding cables to be taken into account. Motor voltage transients and related conducted electromagnetic emission are significantly correlated with resonance effects occurring in load circuits. The levels of intensity of these phenomena...
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The differential impact of a density of Polish pine wood on cutting forces with its origin region taken into consideration
PublikacjaIn the article the dependence of cutting forces in a function the density of wood with regard to the wood origin are presented. Samples used in experiment were with Scotch pine (Pinus sylvestris L.) originating from four provenances in Poland (Figure 1). Wood density was measured by two methods: stereometric method (global density) and radiometric method (local density). Stereometric method consists in measurements the volume...
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The distributed model predictive controller for the nuclear power plant turbo-generator set
PublikacjaTypically there are two main control loops with PI controllers operating at each turbo-generator set. In this paper a distributed model predictive controller DMPC, with local QDMC controllers for the turbine generator, is proposed instead of a typical PI controllers. The local QDMC controllers utilize step-response models for the controlled system components. These models parameters are determined based on the proposed black-box...
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Scenarios in regional planning – theory and practice in Poland
PublikacjaAbstract. It is important to recognise future conditions in planning because it primes future actions. Scenarios are useful prognostic tools, especially when the social and institutional behaviour plays a crucial role. The aims of the paper are: (1) to indicate the roles and the place of scenarios in the strategic plan building process; (2) to analyse and evaluate the application of scenarios in regional planning in Poland; (3)...
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Water related esthetics - the phenomenon of new structure in the post industrial shipyard areas
PublikacjaDirection of the main movements that are made in the European cities determines not only structural but also an esthetic changes. Paper follows the topic of visual diversity of post industrial waterfront cities and it’s relation to the local identity and cultural changes that are provided. Reshaping of the cities continuously proceed. Are those changes related with industrial shipyard districts only economical and spatial or also...
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Robustness Analysis of a Distributed MPC Control System of a Turbo-Generator Set of a Nuclear Plant – Disturbance Issues
PublikacjaTypically, there are two main control loops with PI controllers operating at each turbo-generator set. In this paper, a distributed model predictive controller with local quadratic model predictive controllers for the turbine generator is proposed instead of a set of classical PI controllers. The local quadratic predictive controllers utilize step-response models for the controlled system components. The parameters of these models...
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Effect of Sinusoidal Corrugated Geometries on the Vibrational Response of Viscoelastic Nanoplates
PublikacjaThe vibrational behavior of viscoelastic nanoplates with a corrugated geometry is a key topic of practical interest. This problem is addressed here for wrinkled nanoplates with small corrugations related to incorrect manufacturing. To this end, a new One-Variable First-order Shear Deformation plate Theory (OVFSDT) is proposed in a combined form with a non-local strain gradient theory. The Kelvin–Voigt model is employed to describe...
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Comparison of strain results at a laser weld notch obtained by numerical calculations and experimental measurements
PublikacjaIn the development of ship structures applying new materials and it’s purposeful placement play an important role. During the last years, especially in a construction of ro-ro type vessels, the usage of novel sandwich structures in cargo decks is profitable. Steel sandwich panel is an innovative solution which at a todays state of development can be used for the construction of any members not taking part in a global bending of...
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More freedom – more investments. The relationship between the extent of fiscal autonomy with respect to own revenues and investment expenditures of Polish communes and cities with county rights
PublikacjaThe purpose of this study was to investigate the relationship between own revenues characterized by different levels of fiscal autonomy and investment expenditures of selected local government entities in Poland. Accordingly, the following research hypothesis was formulated: there is a relationship between the type of own revenue identified with respect to fiscal autonomy and the size of investment expenditures. Revenues characterized...
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Shallow Water Equations as a Mathematical Model of Whitewater Course Hydrodynamics
PublikacjaPredicting the positions of local hydraulic phenomena, as well as accurately esti-mating the depth and velocity of the water flow are necessary to correctly config-ure a whitewater canoeing course. Currently, a laboratory and full 3D CFD model-ing are typically used in the design process to meet these needs. The article points to another possibility which can be useful at the preliminary stage of the design. The authors show that...
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Innovative mobile method to determine railway track axis position in global coordinate system using position measurements performed with GNSS and fixed base of the measuring vehicle
PublikacjaThe shape of the railway track axis and its position in the global coordinate system are essential when defining design parameters of the railway. Correct reconstruction of these quantities is vital for both verifying the compliance of real track parameters with the design and for diagnosing, as all track deformations can also be defined as deviations of real parameters from their design values. The measurements of quantities related...
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Parki tematyczne w rozwoju lokalnym miasteczek i wsi
PublikacjaObecnie niemal każde polskie miasto i wieś ma na celu znalezienie dobrego pomysłu na swój rozwój społeczno-gospodarczy. Najczęściej jest nim założenie parku tematycznego. Dobrze się dzieje, gdy takie przedsięwzięcie wspiera lokalne tradycje, zwyczaje i walory kulturowe miasta czy wsi; gdy promowane są miejscowe produkty i żywność. Niestety, nie zawsze tak jest. Niektóre miasta i gminy chętniej przyjmują zupełnie inną politykę...
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Determination of Mathematical Model Parameters of a Medium Frequency Transformer
PublikacjaThe paper presents the results of experimental studies of the medium frequency transformer. The object of the research was a prototype of a single-phase transformer with a core made of ferrite I-core elements and windings made of Litz conductors. The research was carried out to determine the parameters of the transformer's mathematical model. The scope of the tests included determining the magnetic hysteresis loop and measuring...
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Improvement of electrochemical action of zinc-rich paints by addition of nanoparticulate zinc
PublikacjaThe influence of nanosized particles on electrochemical action of standard zinc-rich paints by means of SEM as well as potential and impedance measurements has been investigated. The motivation for doing this was to obtain additional electrical connection between the spherical microparticles themselves and zinc particles and steel substrate. Overall zinc content was at the level of 92% by weight. Samples with different concentration...
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Left-handed propagation characteristics of a dielectric and metal-loaded periodic circular waveguide
PublikacjaIn this paper, a periodic dielectric/metallic rod is located in a circular waveguide to obtain left-handed operation. Two geometries of the dielectric/metallic rod are proposed and examined. The dispersion characteristics of the investigated waveguides are obtained using a surface impedance model. Moreover, equivalent circuit models are proposed allowing for calculation of the dispersion characteristics and scattering parameters...
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A novel sensor for measuring temperature profile during the thermoablation
PublikacjaAbstract — A novel approach for monitoring a temperature distribution inside a tissue during thermoablation is presented in the paper. A thermal profile is measured using a set of serially connected thermistors each bypassed by a capacitor. This technique allows a two-wire and simultaneous multi- point measurements using a multi-frequency measurement of electrical impedance. It is...
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Electrical conductivity and relaxation processes in V2O5 nanorods prepared by sol–gel method
PublikacjaProperties of high purity V2O5 nanorods prepared by a sol – gel method are presented. The studied materials were characterized by: X-ray diffractometry (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The electrical impedance was measured as a function of temperature and frequency. The obtained results show that the electrical conductivity increases with increasing temperature. The d.c. conductivity...
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Exploring Mechanism of Corrosion Inhibition of WE43 and AZ31 Alloys by Aqueous Molybdate in Hank’s Solution by Multisine Impedimetric Monitoring
PublikacjaThe concept of utilizing multisine dynamic electrochemical impedance spectroscopy to monitor effectiveness of a model molybdate inhibitor for AZ31 and WE43 Mg alloys is proposed. The corrosion kinetics and instantaneous values of inhibition efficiency (IE) of molybdate at concentrations up to 150 mM were examined. The inhibitor provides inhibition in Hank’s solution at concentrations starting from ca. 25 mM, with the IE of about...