... I Capacitive Behavior in Conducting Polymers: AC Impedance and Quartz Crystal Microbalance Studies by ... AC Impedance Analysis - ...

... inhibition was studied using impedance spectroscopy and potentiodynamic methods. Results obtained from the AC impedance measurements are ...

... electrochemistry of titanium in the LiCl-KCl eutectic melt has been investigated by means of pulse techniques and ac impedance measurements. ...

... Abstract : Although ac impedance has come to prominence lately for studying anti ... At first sight this is surprising since the techniques are very ...

... Title : AC IMPEDANCE MEASUREMENT OF ENVIRONMENTAL ... OF INTERFACIAL IMPEDANCE MEASUREMENT ARE ... OF THE METHOD IN ...

... This study is part of a general development of the ac-impedance method for measurement of the properties of coated metals. (Author). ...

... presaturated with the corrosion products. An AC impedance technique for the total electrical conductivity, the potentiostatic polarization method for ...

... systems was necessary. In addition, ways for obtaining corrosion rates from AC impedance methods were investigated. ...

Infrared spectroscopy is used to characterize the molecular structure and orientation of acetonitrile adsorbed at the Au/aqueous solution interface. AC impedance measurements are used to determine the stoichiometry and energetics of the adsorption process...

... BY DC AN AC ELECTROCHEMICAL TECHNIQUES AS COMPARED ... IMPEDANCE DIAGRAMS SHOW THAT A SLIGHTLY ...

... REPORTED. THE BACKGROUND AND VARIOUS METHODS OF ANALYSIS OF AC IMPEDANCE DATA ARE DISCUSSED. THE ...

... Abstract : Experimental approaches for recording ac impedance data are ... Additional methods for analysis of experimental impedance data are ...

Experimental approaches for recording ac impedance data are discussed in this paper. Considerations of the high frequency performance of potentiostats and reference electrodes are given and experimental results are presented. Additional methods for analysis of experimental impedance data are discussed, with emphasis on the CIRFIT ...

... m/s) has been studied as a function of oxygen concentration using the linear polarization, ac impedance, and potential step methods for measuring ...

Improved methods are needed to characterize ac system harmonic behavior for ac filter design for HVDC systems. The filter design practice is evaluated and methods for calculating system harmonic impedances are investigated. An overview of ac filter design for HVDC systems and a survey of literature related to ...

... zinc phosphate coatings on steel surfaces with different pretreatment have been studied with preliminary analysis using ac impedance techniques. ...

... comparison is made between two electrical techniques for studying the deterioration of polymer-coated metals. AC impedance measurements and ...

... Title : APPLYING AC IMPEDANCE ELECTROCHEMICAL METHODS TO CORROSION TESTING COBALT ALLOY MEDIA. Corporate Author : ...

We report on impedance magnetocardiography studies using high-Tc superconducting quantum interference device (SQUID) magnetometers in a partially shielded environment. The SQUID detects magnetic-field variations due to impedance changes in the thorax at 15 kHz. SQUID measurements are compared to impedance ...

... Title : A Corrosion Monitor Based on Impedance Method,. ... were performed on the impedance characteristics of ... the aid of a new ac corrosion monitor. ...

In this study, we have investigated the properties of discontinuous-Co80Fe20/?-Fe2O3 multilayers by AC impedance technology. The specific feature of the impedance spectra varies with of Co80Fe20 layer characteristics, being related to isolated sate or percolation state of Co80Fe20 cluster in ?-Fe2O3 matrix. The ...

... IS BASED ON AN AC METHOD KNOWN IN ... WHEN AC CURRENT FLOWS THROUGH THE SYSTEM, IT ... LAYER AND AN IMPEDANCE OF THE ...

... Title : AC MAGNETIC FIELDS IN THE ... CALCULATIONS OF THE IMPEDANCE OF A ... IS ACCOMPLISHED BY TWO INDEPENDENT METHODS. ...

To investigate metal surface corrosion and the breakdown of metal protective coatings, the ac impedance method is applied to six systems of primer coated and primer topcoated 4130 steel. Two primers were used: a zinc-rich epoxy primer and a red lead oxide...

Polyaniline (PANI) membranes symmetrically bathed by electrolyte solutions on both faces have been studied by ac impedance. The membrane impedance is very sensitive to both solution pH and membrane potential, being lower under the conditions for which PANI is an electronic conductor: it increases by several orders ...

This report described the possible application of ac impedance analysis for diagnosis of cell capacity degradation of AA size Li/MoO2 secondary cells. Electronic internal resistivity (R(sub s)), interfacial resistivity between lithium negative electrode a...

Lithium batteries are some of the best candidates for use as high energy density batteries and have been widely studied. Electrodeposited lithium was evaluated by ac impedance measurement and optical microscopy in two solutions containing LiClO[sub 4]; a propylene carbonate (PC) solution and a blended solution consisting of PC and ...

... TR-2004(8555)-2 AC Impedance Testing on 40-Ah Li-Ion Cells 20 October 2004 ... AC Impedance Testing on 40-Ah Li-on Cells 5b. GRANT NUMBER ...

This report summarizes the results of a study of LiCl film formation on lithium anodes on thionyl chloride batteries. The film formation was monitored by ac impedance measurements in up to 4 years and the resulting morphology was studied by scanning elect...

... of a Scanning Electrochemical Impedance Spectroscopy Technique ... This article describes a method of generating ... by driving an ac current between ...

... and DC electrochemical techniques have verified that the low-frequency impedance spectrum obtained from the AC Impedance technique is ...

... and DC electrochemical techniques, have verified that the low-frequency impedance spectrum obtained from the AC Impedance technique is ...

... Methods of obtaining the complete negative resistance ... amplifier load impedance effects the input impedance. ... be evaluated at the ac frequencies of ...

... was examined by applying the methods described below. ... Electrochemical Measurements: Alternating current (AC) impedance measurements were ...

... Abstract : Electrochemical techniques for predicting stress corrosion cracking (SCC ... potentials with continuous recording of the ac impedance in a ...

... Abstract : Two in situ techniques, dynamic imaging ... LEIS is an electrochemical impedance technique that generates local ac impedance data by ...

... of the ac impedance at a metal-electrolyte interface as a function of frequency are depicted, and recently developed measurement techniques are ...

... From the latter, the coil impedance and the ... FIELDS, HALL EFFECT, ELECTRICAL IMPEDANCE, COILS, VOLTAGE, CONDUCTIVITY ...

... Accession Number : ADD854901. Title : Inductance Effect in the AC Impedance of Conducting Polypyrrole Films. Descriptive Note : Journal article,. ...

... TECHNICAL REPORT NATICK/TR-93/019 AD ALTERNATING CURRENT (AC) IMPEDANCE TESTING OF COATED TRAYCANS By Kurt Lawson ...

... Accession Number : ADA261256. Title : Alternating Current (AC) Impedance Testing of Coated Traycans. Descriptive Note : Final rept. ...

... Title : Ac Impedance Investigation of Ta2O5 Film for Use as a Storage Capacitor Dielectric. Descriptive Note : Journal article,. ...

... Accession Number : ADA428218. Title : AC Impedance Testing on 40-Ah Li-Ion Cells. Descriptive Note : Technical rept. ...

... Accession Number : ADD854551. Title : AC Impedance Method for High-Resistivity Measurements of Silicon. Descriptive Note : Journal article,. ...

... Title : AC Impedance Analysis of Corrosion Fatigue in Naval Aircraft Alloys. ... this program is to develop rapid electrochemical methods for evaluating ...

... Title : AC IMPEDANCE INVESTIGATION OF TA(2)O(5) FILM FOR USE AS A STORAGE CAPACITOR DIELECTRIC. Corporate Author : ...

The a.c. impedance method is a very useful technique for studying the corrosion behaviour of surgical implant alloys. In this article information is presented on how to efficiently and reliably acquire and analyse experimental data through the use of Nyquist, Bode and Rre versus omega Rim plots. Also, experiments were conducted in ...

The kinetics of lithium passivation and the development of the impedance of carbon electrodes and LiGaCl4 and LiAlCl4 nonsolvate electrolytes in rechargeable Li/So2 cells have been studied using the ac impedance technique. The effects of cycling and depth of discharge (DOD) on impedance ...

... in the AC Response of an ... LEAST SQUARES METHOD, CHARGE TRANSFER ... COEFFICIENT, EQUATIONS, IMPEDANCE, BINARY COMPOUNDS. ...

... Title : Measurement of Low Corrosion Rates: Comparison of ac Impedance and Thin Layer Activation Methods,. Corporate Author : ...

... Assisted DC and AC Techniques in Electrochemical ... data acquisition and calculation method, allows the ... Impedance measurements give the same ...

This paper reports on a local electrochemical impedance spectroscopy (LEIS) technique for mapping the ac impedance distribution, as a function of frequency, of an electrode. In LEIS, as in traditional ac impedance methods, a sinusoidal voltage perturbation between the working and reference ...

... jUN 0 91994D * F ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY OF ... 16. PRICE COOE ac-Impedance, Chromate, Aluminum Alloys 17. ...

Nickel-copper alloy modified glassy carbon electrodes (GC/NiCu) prepared by galvanostatic deposition were used for the electrocatalytic oxidation of glucose in alkaline solutions. The electro-oxidation of glucose in a 1 M NaOH solution at different concentration of glucose was studied by the method of ac-impedance spectroscopy. The ...

AC impedance spectroscopy and chronopotentiometry have been used to study solid-state ionic conductors. Results obtained using three electrodes are compared to those using a two-electrode configuration. The uncompensated resistance was shown to depend str...

Emphasis is placed on the development of ac impedance as a nondestructive evaluation methodology for solar arrays and the further development of corrosion models and materials selection criteria for corrosion resistant interfaces.

The behavior of an inhomogeneous superconductor in an external a.c. field is studied. General equations describing the a.c. response are formulated. Special attention is paid to the case of a layered conductor containing superconducting ''islands''. A system of this type displays ...

Water and ice were investigated by ac impedance with the electrochemical properties cup in an effort to develop an in situ instrument for water characterization. In liquid water, the impedance modulus decreased with the increase in charge carriers. In the ice, the impedance measurements were characterized by the ...

... SAMPLE AND AN AC MAGNETIC FIELD ... FREQUENCY, WHERE IMPEDANCE HERE IS ... THE RECONSTRUCTION METHOD ARE PRESENTED ...

... METHODS DISCUSSED INCLUDE POSITRON ANNIHILATION, AC- IMPEDANCE SCANNING, SCANNING LASER ACOUSTIC MICROSCOPY ...

... OF INFLUENCING PARAMETERS BY IMPEDANCE PLANE ANALYSIS ... AC MAGNETOGRAPHY ... A SERIES OF TEST METHODS INTEGRATED IN A ...

... EVALUATION OF THE STATE OF CHARGE OF BATTERY ELECTRODES WITH AC IMPEDANCE TECHNIQUES Principal Investigator: Prof. ...

... CORROSION, CORROSION FATIGUE, AND STRESS CORROSION CRACKING) TO THE USE OF AC IMPEDANCE TECHNIQUES AND A ...

... DC AND AC TECHNIQUES WHICH CAN ... THE EXTRAPOLATION METHOD OF TAFEL ... MEASUREMENTS AND IMPEDANCE MEASUREMENTS ...

... APPLICATION OF COLLOCATION METHODS REDUCES THE ... CRACK IN THE AC FIELD OF A ... AS WELL AS THE IMPEDANCE CHANGES DUE ...

The power efficiency of silicon nanocrystal light-emitting devices is studied in alternating current (ac) regime. An experimental method based on impedance spectroscopy is proposed. The power efficiency in ac regime is higher than the one measured in direct current before a threshold frequency and decreases ...

This conference proceedings contains 24 papers, of which 2 are indexed separately. The topics discussed ranged from various aspects of localized corrosion phenomena (such as pitting, crevice corrosion, corrosion fatigue, and stress corrosion cracking) to the use of a-c impedance techniques and a number of special areas usually not discussed in detail ...

In this paper the kinetics of the insertion of Na into the layered Na[sub x]Mo[sub 2]O[sub 4] system upon charge and discharge is studied by means of ac-complex impedance spectroscopy. The Na diffusion coefficient values deduced correlate well with the structural modifications occurring in these monoclinic molybdates upon Na ...

Impedance spectroscopy has been used to study the effect of kaolinite grain sizes on the AC electrical properties of kaolinite/polystyrene composites under different temperatures and applied frequencies. Impedance measurements were performed on prepared composites containing 20% kaolinite mineral of grain sizes 63, ...

Electrochemical corrosion testing using AC impedance measurement and ellipsometry has been performed on aircraft aluminum 2024-T3 samples. The AC Impedance technique was used to acquire a precise low-frequency impedance signature of corroding painted airc...

The AC-impedance technique was experimentally evaluated as one of the in-situ measuring means to determine the corrosion rate of metals immersed in aqueous solutions. Surface impedance of corroding metals was measured by both the FET and FRA methods using...

This report describes the possible application of ac impedance analysis for diagnosis of cell capacity degradation of AA size Li/MoS2 secondary cells. Electronic internal resistivity R(sub s), the interfacial resistivity between the lithium negative electrode and the electrolyte R(sub n), and the constant parameter of Werburg impedance ...

One of the age-related changes occurring in dentine structure is the formation of peritubular dentine on the inner walls of dentinal tubules leading to complete closure of tubules. Ac-impedance is safe, fast and non-invasive technique. In the last decade, the popularity of the technique has increased in dental research. Several investigators have used the technique to detect ...

A comprehensive study has been undertaken to investigate the ability of AC-impedance spectroscopy (AC-IS) to non-destructively monitor the fiber dispersion of conductive fiber-reinforced cement-based materials. Previous work showed that AC-IS effectively monitors various fiber dispersion issues in lab-scale steel ...

This paper reports ac impedance and cyclic voltammetry studies of underpotential deposition (UPD) of Cu on Au in an electrolyte composed of CuSO/sub 4/ and H/sub 2/SO/sub 4/. A theoretical kinetic model was developed which fits the experimental impedance spectra over frequencies ranging from 0.001 to 20,000 Hz. ...

Measurements of intrinsic conductance fluctuations often make use of a.c. modulation methods. Such methods are beneficial in reducing the contribution of amplifier noise to the final power spectrum and also in rejecting Johnson noise. The present study has two goals. First, we reexamine a.c. modulation methods when the sample being ...

Poly(butylenes adipate) ionomers (PBAi) were synthesized using dimethyl 5-sulfoisophthalate sodium salt (DMSI) up to 5 mol% of diacid monomer. We have investigated electrical and dielectric properties of the ionomers to evaluate alternating current (AC) parameters such as impedance, conductance, dielectric constant, admittance, susceptance, dielectric ...

In the present study the tool of impedance spectroscopy was utilized to characterize dielectric behavior of ferroelectromagnetic ceramics of Bi9Fe5Ti3O27 composition fabricated by hot pressing method from the stoichiometric mixture of oxides Bi2O3, TiO2 and Fe2O3. Impedance spectroscopy was applied to characterize relaxation processes ...

The ac conductivity and dielectric properties of glassy system SexTe79 - xGe21, with x = 11, 14, 17 at.%, has been studied at temperatures 300 to 450 K and over a wide range of frequencies (50 Hz to 500 kHz). Experimental results indicate that the ac conductivity and the dielectric constants depend on temperature, frequency and Se ...

The dc and small-signal ac impedances of a flooded-agglomerate element of a porous gas-diffusion electrode have been calculated. The complete solution involves a nonlinear concentration profile within the agglomerate and requires numerical integration. An approximate solution has been developed leading to a simple equivalent circuit that is valid for most ...

Computerized graphical and chemical analyses were used to study the effect of frequency on corrosion impedance for the systems: Armco iron/H/sub 2/SO/sub 4/ and St3 steel/H/sub 2/SO/sub 4/ with and without the addition of propargyl alcohol inhibitor, St3/NaCl, and St3/circulated water. The Epelboin equation for the effect of frequency on the ...

Electric cell-substrate impedance sensing (ECIS) has been developed as a non-invasive means to follow cell behavior in culture. In this method cells are cultured on small (250 micrometer diameter) gold film electrodes. The impedance of the electrode is measured by an AC current about 1 microampere. When challenged by biochemical or ...

... ORiGNATIN- AC tIVITy (, po*e -Ithot) 2 I ... between tidal volume and thoracic impedance was determined by analog and digital methods. ...

Jan 22, 2011 ... Abstract: This paper discusses a task the objective of which is to characterize solar cell array AC impedance and develop scaling rules for ...

Large conducting space structures in low Earth orbit will have a nonnegligible induced potential across their structures. The induced current flow through the body and the ionosphere causes the radiation of Alfven and lower-hybrid waves. This current flow is taken to be ac, and the radiated power is studied as a function of the ac ...

Large conducting space structures in low Earth orbit will have a nonnegligible motionally induced potential across their structures. The induced current flow through the body and the ionosphere causes the radiation of Alfven and lower hybrid waves. This current flow is taken to be ac, and the radiated power is studied as a function of the ...

... Title : RELIABILITY AND THERMAL IMPEDANCE STUDIES IN SOFT SOLDERED POWER TRANSISTORS. Corporate Author : ...

... frequency dispersion of the impedance is observed ... A method of estimating the true specific ... at gold/solution interface, ac admittance techniques ...

Electric Impedance Tomography; Bronchoscopy; Change in Lung Impedance Due to Ventilation; Recruitment; Improvement the Treatment of the Patient

The ac impedance of the interface between a blocking electrode and an aqueous or solid electrolyte often contains a constant-phase-angle (CPA) element whose impedance has the frequency dependence given by Z( omega ) proportional to (j omega ) sup - /sup e...

A least-squares fitting routine has been developed for the analysis of ac impedance data. It has been determined that the checking of the derived equations for a particular circuit with a commercially available electronics circuit program is essential. As...

To investigate metal surface corrosion and the breakdown of metal protective coatings, the ac Impedance Method was applied to zinc chromate primer coated 2219-T87 aluminum. The EG&GPARC Model 368 ac Impedance Measurement System, along with dc measurements...

The small signal ac impedance of the interface between a blocking electrode and an aqueous or solid electrolyte often contains a constant-phase-angle (CPA) element whose impedance has the frequency dependence according to Z proportional to (j omega )/sup ...

A polythelene glycol (PEG) polymer was synthesized using a dip coating procedure on 316L stainless steel (SS) substrate pre coated by radio frequency RF inductively coupled plasma polymerization with di (ethylene glycol) vinyl ether (EO2V) monomer that was used as a primer coat. The primer and PEG composite film was studied with profilometer, visible-light microscope, scanning ...

A polyethylene glycol (PEG) polymer was synthesized using a dip coating procedure on 316L stainless steel (SS) substrate pre-coated with a primer that consisted of radio frequency RF inductively coupled plasma-polymerized di (ethylene glycol) vinyl ether (EO2V). The primer and PEG composite film was studied with profilometer, optical microscope, scanning electron microscope ...

Ion conducting polymer electrolyte PVA:NH(4)NO(3) has been prepared by solution casting technique and characterized using XRD, Raman and ac impedance spectroscopic analyses. The amorphous nature of the polymer films has been confirmed by XRD and Raman spectroscopy. An insight into the deconvoluted Raman peaks of upsilon(1) vibration of NO(3)(-) anion for ...

Solar. Subsystems. FIGURE 1. Model Spacecraft With Subsystems. Although the .... minimum ac impedance between each circuit common and chassis. ...

... integrals allows the discussion of a wide range of electrochemical techniques and in this paper we discuss the derivation of the AC impedance of a ...

... AC detection and a complex RC feedback impedance is provided to give the detecting circuit an output proportional to the energy content of an ...

... the techniques being developed or investigated are NDT methods which include electrochemical (linear polarization, ac impedance, and small ...

... The primary advantage of the method lies in the fact that a non ... Because of this, the ac impedance depends on frequency but not on the dc voltage ...

... THE PROBLEM OF THE AC MAGNETIC FIELD ... A LOWER DIMENSION, THE SECOND METHOD FITS BETTER ... OF THE TOTAL IMPEDANCE OF A ...

... Using the method of singular perturbations I ... Implementation of an Impedance Boundary Condition ... of Engineering Mathematics, ac- cepted, August ...

... ionic conductivity and compressive modulus were measured by AC impedance and compression respectively. Dynamic Mechanical Analysis was ...

A microfabricated instrument for detecting and identifying cells and other particles based on alternating current (AC) impedance measurements. The microfabricated AC impedance sensor includes two critical elements: 1) a microfluidic chip, preferably of glass substrates, having at least one microchannel therein and ...

... In accordance with one method of this invention ... analog voltage which represents the AC component that is phase shifted by the impedance of the ...

... involves the application of a variety of pulses and ac methods with the intention of assigning an aperiodic circuit from electrode impedance analysis ...

... Title : Measurement of Battery Separator Resistances in Low Impedance Conductivity Cells by AC Bridge Techniques. ...

... involves the application of a variety of pulse and ac methods with the intention of assigning a periodic circuit from electrode impedance analysis. ...

It has been observed that ac impedance measurements made over a wide frequency range can be used to determine the electrical properties of photovoltaic solar cells. The occurrence of a distribution of time constants for an array of cells indicates that one or more cells deviate significantly from the values of cells which operate properly. In some cases, ...

... There are two electrochemical methods that are commonly used to monitor the corrosion behaviour of materials: DC Potential and AC Impedance. ...

... L in hydrazine have also been measured by several electrochemical techniques such as Tafel plots, polarization resistance, and AC Impedance. ...

... Descriptors : *POLYMERIC FILMS, *PYRROLES, *CAPACITANCE, *THIN FILMS, ALTERNATING CURRENT, MICROSCOPY, HIGH ENERGY ...

... This requirement vas ac- ... third aspect is the change in impedance, and especially the ... efficiency of buried antennas by theoretical methods has been ...

... Title : ANODIC CHARACTERISTICS OF Ni RICH ALLOYS MEASURED BY THE AC IMPEDANCE METHOD,. Corporate Author : ...

... rectifying the AC voltage signals generated by the ... and a source impedance 91 represent the ... Disclosed Method" section, of a transmission line ...

A methodology for detecting and locating defects or discontinuities on the outside covering of coated metal underground pipelines subjected to cathodic protection has been addressed. On the basis of wide range AC impedance signals for various frequencies applied to a steel-coated pipeline system and by measuring its corresponding transfer function under ...

Impedance spectroscopy is often used to analyse the electrical properties of ceramic materials having high-resistive grain boundaries, such as ZnO and SrTiO{sub 3}. Fewer attempts have been made at using this technique for the analysis of inhomogeneous electronic ceramics consisting of grains with differing composition, such as those occurring in negative temperature ...

Recently, the authors have proposed a method for generating local electrochemical impedance maps of electrodes. In this technique impedance maps, at each frequency of interest, are generated by measuring the ratio of ac solution current density, very near...

Performance of lithium-ion batteries at low temperatures and/or high rates is relatively poor due to high cell internal impedance. The ac impedance spectroscopy was utilized to determine the impedance characteristics of lithium- ion cells as a function of...

Jan 22, 2011 ... dc.subject.other, solar cells solar arrays AC impedance Mars ... dc.title, ( abstract) Scaling Nominal Solar Cell Impedances for Array Design ...

We report on Impedance Magnetocardiography (IMCG) measurements using High-Tc SQUID magnetometers in an unshielded environment. A low amplitude high frequency ac current is passed through the body through outer electrodes. Variations in blood flow during the cardiac cycle generate currents that give rise to time varying magnetic fields. Potential ...

AC-impedance measurements have been used for a number of years for laboratory screening of chemical corrosion and scale inhibitors and assessment of other chemicals for use in oil flowlines. In this paper the viability of using the AC-impedance technique as a field tool where the corrosion performance is measured in the production fluids and not under ...

In an effort to investigate metal surface corrosion and the breakdown of metal protective coatings the AC Impedance Method was applied to zinc chromate primer coated 2219-T87 aluminum. The model 368-1 AC Impedance Measurement System recently acquired by t...

AC impedance has provided a useful diagnostic tool in the Los Alamos polymer electrolyte fuel cell (PEFC) program. The author reviews the techniques he has used in ac impedance modeling. These techniques include equation implementation, model simplification and verification, least squares fitting, application of ...

The ac impedance measurement has proved to be a useful electrochemical technique for mainly qualitative studies of electrochemical and corrosion systems. Even for complicated systems such as coated metals in corrosive environments this technique has been used with success. The system chosen for the present study is ...

Single phase perovskite Ba(Sr1/3Nb2/3)O3 ceramics was prepared using the columbite precursor method. X-ray diffraction (XRD) technique is used to verify the single phase formation. It stabilizes in hexagonal phase with lattice constants a=12.1243 � and c=15.3747 �. Impedance analysis shows distributed relaxation time. Single semicircular arc observed in complex ...

Pitting corrosion of stainless steel has been extensively studied by electrochemical impedance spectroscopy (EIS). However, the frequency dependence of the current distribution is much different in the vicinity of a pit than on the passivated part of the surface. Therefore a localized electrochemical impedance technique has been ...

The early validation of a 20 year service integrity for the bonded interface in solar sell modules is an important requirement in the Low Cost Solar Array (LSA) project. In the present fifth phase of study summarized here emphasis is placed on the development of materials selection criteria for encapsulant bond integrity and more fully validating AC ...

... MEASUREMENTS. IMPEDANCE PLETHYSMOGRAPHIC DETERMINATION OF CARDIAC OUTPUT (AN INTERPRETIVE STUDY),. ...

... MEASUREMENTS. IMPEDANCE PLETHYSMOGRAPHIC DETERMINATION OF CARDIAC OUTPUT (A COMPARATIVE STUDY),. ...

... NUCLEAR EXPLOSION DAMAGE, SURFACE ROUGHNESS, WALLS, PROTECTION, MECHANICAL IMPEDANCE, TURBULENCE, PRESSURE. ...

... Descriptors : *IMPEDANCE, *VOLTAMMETRY, *POLYANILINES, *CONDUCTIVE POLYMERS, CONDUCTIVITY, SPECTROSCOPY, SYNTHESIS ...

Mn1.85Co0.3Ni0.85O4 thin films with single cubic spinel phase and compact surface were prepared by chemical solution deposition method on Al2O3 substrates. Temperature dependent ac impedance spectroscopy was employed to analyze the contributions of grain boundary (GB) and grain to the conduction mechanism. The major characteristics (hopping type, ...

The variations of several electrical properties of nickel cadmium cells with state of charge were studied to determine the suitability of any of these for measuring state of charge. Three methods were originally proposed: measurements of ohmic resistance, microsecond transients, and double layer capacitance. During the investigations two additional parameters were measured, ...

Relaxation and conduction mechanisms under small ac fields of laser ablated ZrTiO4 thin films were analyzed in the light of impedance and modulus spectroscopy. The overall dielectric properties were mainly dominated by a Maxwell-Wagner type of relaxation with grains and the grain boundary two distinct parts of the circuit. Each of these parts was found to ...

Complex impedance spectroscopic studies were carried out on RbNO3 and RbNO3 Al2O3 dispersed solid electrolyte systems (DSES) in the temperature range of 50 �C to 300 �C and the frequency 50 KHz to 1 MHz. Dielectric constant, loss tangent, and AC conductivity, in these systems are presented. Dielectric constant, loss and ...

Broad-frequency dielectric behaviors of multiwalled carbon nanotubes (MWCNTs) embedded in room temperature vulcanization silicone rubber (RT-SR) matrix were studied by analyzing alternating current (ac) impedance spectra, which would make a remarkable contribution for understanding some fundamental electrical properties in the ...

The purpose of this research was to determine whether oxygen molecules, hydrogen ions, or aluminum ions initiate the crevice corrosion of aluminum alloy 6061 in aqueous chloride solutions. Corrosion-potential and ac-impedance measurements show that pH is the dominant factor in accordance with the crevice-corrosion mechanism. It is further proposed that crevice corrosion occurs ...

Corrosion of steel during oil well acidizing or acid pickling treatments can be controlled effectively and economically with corrosion inhibitors. It is generally accepted that these additives function by forming an adherent barrier on the steel surface, the nature of which depends on various physiochemical properties of the inhibitor. Work to date has established that acetylenic alcohols first ...

Improved methods are needed to characterize ac system harmonic behavior for ac filter design for HVDC systems. The purpose of this General Electric Company RP1138 research is to evaluate the present filter design practice and to investigate methods for calculating system harmonic impedances. An overview of ac ...

point that is relatively insensitive to the transistor beta. By adding AC bypass capacitors as an AC short circuit at high enough frequency. What is the magnitude of the impedance of a l0�F capacitor the bypass capacitor). Measure the AC output signal. Comment. Estimate the output resistance of the CE

A new application using barium strontium titanate (BST) thin films to fabricate the Pd/BST/Pt heterostructure for hydrogen gas detection has been investigated. To further understand the mechanism of this novel hydrogen sensing properties, impedance spectroscopy of the Pd/BST/Pt has been systematically studied and interpreted satisfactorily based on an ...

Lanthanum fluoride nanoparticles have been synthesized by the simple method of direct precipitation from an aqueous solution. TG/DTA analysis confirms the sample formation at low temperature (300 �C). Structure of LaF3 nanoparticles has been analyzed by XRD and LaF3 is found to be in tysonite structure. From the XRD spectra the average particle size is found to be 15 nm using the Scherrer ...

This paper discusses the Fe{sup 3+} reduction reaction studied at Pt and polyaniline rotating disk electrodes by steady-state and impedance methods with the aim of testing the possibility of achieving the charge transfer resistance (R{sub ts}) of a redox reaction mediated by a conducting polymer film by ac ...

AC four-point impedance spectroscopy has been applied to Nb-doped SrTiO{sub 3} bicrystals. Due to the simplified geometry and highly conductive bulk of the bicrystal, the reference impedance of the electrode was significantly reduced, validating the applicability of ac four-point impedance ...

The electrical properties of alizarin doped anthraquinone were investigated using a complex impedance spectroscopy technique. Dielectric study revealed a phase transition from the semiconducting to the conducting state at 53�C. The dielectric relaxation was found to be of non-Debye type. Evidence of temperature-dependent electrical relaxation phenomena ...

Gold nanoparticles have been synthesized in a base glass with composition 30Li2O-70B2O3 using gold chloride (HAuCl4.3H2O) as a dopant. The samples are characterized using XRD, ESR, SEM and optical absorption in the visible range. AC conductivity studies have been performed at RT over a frequency range 100 to 10 MHz. The dc conductivity is calculated from ...

This website includes an explanation of impedance in AC circuits, along with an applet that draws graphs and phasor diagrams for some important variables in the circuit. The explanation of impedance gives formulas for reactance, impedance and resonance, and explains the importance of resonance. The applet allows ...

AC impedance spectroscopy and chronopotentiometry have been used to study solid-state ionic conductors. Results obtained using three electrodes are compared to those using a two-electrode configuration. The uncompensated resistance was shown to depend strongly on the geometric placement of the electrodes. The optimal configuration for ...

S>Experimental results on the effects of nuclear radiation in a group of coaxial cables are presented. The effects studied include cchanges in d-c insulation resistance, a-c breakdown voltage, and characteristic impedance after a given irradiation exposure. Phase and attenuation measureirradiation. (auth)

The interfacial resistance of thin three-layer ceramic solid oxide fuel cell composites was studied at 1000(degrees) using ac impedance techniques. The anode interfacial resistance was found to increase dramatically when the H(sub 2)O content decreased be...

A series of accelerated corrosion tests were conducted in the simulated marine atmosphere environment to study the corrosion of LY12 aluminum alloy under different Cl- deposition content. The change of corrosion morphology, weight gain and electrochemical parameters (Corrosion Electric Potential, AC Impedance) were inspected in the ...

investigations typically greater than about 500 m depth , natural-source EM methods, principally magnetotellurics resistivity. We studied the magnetotelluric responses for three cases A-C as described in the following of Geomagnetism and Geoelectricity, 49, 1519�1539. Bahr, K., 1988, Interpretation of the magnetotelluric impedance

The interfacial resistance of thin three-layer ceramic solid oxide fuel cell composites was studied at 100(degree)C using AC impedance techniques. The anode interfacial resistance was found to increase dramatically when the H(sub 2)O content decreased bel...

In this study, the electrochemical behavior of nano and femtosecond laser textured titanium alloy for implant surface modification has been researched using the potentiostat equipment. Cp-Ti and Ti-6Al-4V alloy, located on X-Y motorized stage, were irradiated using femtosecond laser. The corrosion properties were examined by a potentiodynamic and AC ...

Many efforts in nanobiotechnologies are devoted to the realization of nanodevices based on single receptors for the detection of specific ligands. An interesting tool to monitor the detection process, is provided by the study of the electrical properties of such a device. To estimate the sensitivity of this nanotool, we simulate the current response to an applied ...

Humidity sensing characteristics of NiO/Al2O3 nanocomposites, prepared by sol-gel method, are studied by impedance spectroscopy. Modeling of the obtained impedance spectra with an appropriate equivalent circuit enables us to separate the electrical responses of the tightly bound chemisorbed water molecules on the grain surfaces and the ...

Two in situ techniques, dynamic imaging microellipsometry (DIM) and local impedance spectroscopy (LEIS), were developed and applied to a study of the effect of microstructure on passive film formation and breakdown on Al-Ta alloys. DIM acquires ellipsometric data (thickness and optical constants of the films on surfaces) at a spatial resolution of ca. 20 ...

The extract of Datura stramonium has been studied as a possible source of green inhibitor for corrosion of mild steel (MS) in HCl and H2SO4 media at different temperatures. The anticorrosion effect was evaluated by conventional weight loss studies, electrochemical studies viz., Tafel polarization, ac ...

Complex impedance analysis of a new rare earth-based ceramic oxide, LaLiMo2O8, prepared by a standard solid-state reaction technique has been carried out. Material formation under the reported conditions has been confirmed by X- ray diffraction studies. A preliminary structural analysis indicates the crystal structure to be orthorhombic. Electrical ...

The optical and electrical characteristics of kaolinite/polystyrene composites containing 20 wt% kaolinite with grain sizes of 63, 106, 212 and 300 �m and neat polystyrene were studied. The optical absorption spectra were collected in the wavelength range 300-800 nm using a spectrophotometer. The optical band gap and energy tail widths of localized states were determined for ...

RADC-TR-67-106 Interim Report RF BONDING IMPEDANCE STUDY ... 3 1.1 Systems:of Measurement of Bonding Impedance .... 3 ...

Improved methods are needed to characterize ac system harmonic behavior for ac filter design for HVDC systems. The purpose of this General Electric Company RP1138 research is to evaluate the present filter design practice and to investigate methods for calculating system harmonic impedances. An overview of ac ...

Ac impedance spectroscopy has been used to measure the dynamic response of two types of porous gas-diffusion oxygen electrodes in a sulfuric acid electrolyte. Models were developed based on flooded and on thin-film pore structure. The transfer functions of these structures were calculated and the impedance result fitted to the models ...

The author attended the First International Symposium on Electrochemical Impedance Spectroscopy and presented an invited lecture on the theory of ac impedance of rough electrode-electrolyte interfaces. After the symposium the author spent four days at Ecole Polytechnique, Palaiseau, on the outskirt of Paris to give an invited talk and ...

Impedance measurements have been made in the frequency range 10 Hz-50 kHz and temperature range from 25 to 55 �C on poly(ethylene oxide) doped with iodine. The iodine concentration ranged from 0% up to 10% by weight. Impedance, dielectric constant, dielectric loss, AC conductivity and activation energy showed frequency and ...

Consumers Power Co. coupled field-test data with results of an IIT Research Institute study on powerline-pipeline interaction to characterize a pipeline's reaction to alternating current. An analysis of impedance relationships revealed that values of a-c pipe resistance for wall thicknesses over 0.188 in. (48 mm) vary in ...

Polycrystalline La3/2Bi3/2Fe5O12 (LBIO) compound was prepared by a high-temperature solid-state reaction technique. The complex impedance of LBIO was measured over a wide temperature (i.e., room temperature to 500�C) and frequencies (i.e., 102-106 Hz) ranges. This study takes advantage of plotting ac data simultaneously in the form ...

In-situ neutron diffraction combined with AC impedance spectroscopy was applied successfully to investigate the correlation between crystal structure and electrical properties of the La2Mo2O9 oxide ion conducting electrolyte material. Neutron diffraction patterns were collected as a function of temperature while the AC ...

... Accession Number : AD0634202. Title : ACOUSTIC IMPEDANCE TUBE FOR STUDY OF ANECHOIC COATINGS. Descriptive Note : Progress rept.,. ...

The intent of this work is to develop AC impedance measurements, in combination with other methods, as a tool to determine the relative importance of various resistance sources in the multi-step process occurring at a gas-diffusion porous electrode. In particular, the case of a MCFC cathode is studied. The goals of this ...

The need for the system harmonic impedance information and methods to determine it by test and/or calculation is addressed. The project undertook research to measure harmonic impedances and sources on a power system and to modify existing analytical techniques to more closely match the field test measurements. The information will improve the ability of a ...

Two components of ac electric field are measured by two pairs of long dipole antennas onboard GEOTAIL spacecraft; the wire antenna (WANT) and the probe antenna (PANT). The frequency range is from dc to 800 kHz. To obtain accurate values of electric field components, we should evaluate an exact antenna effective length and an accurate antenna impedance of ...

The Josephson junction is the only radio-frequency electrical element which can be both non-dissipative and non-linear at low temperatures. While the stability of the junction dynamics in presence of a DC drive has been extensively studied, the microwave drive case is relatively poorly understood, at least experimentally. It is explored by driving an increasing ...

The electrical properties of alizarin, a ?-conjugated organic semiconductor, were investigated by the complex impedance spectroscopy technique. A transition from semiconducting to conducting state has been observed and the transition temperature shifts to higher side with the increment in frequency. The dielectric relaxation was found to be of non-Debye type (polydispersive). ...

At operating temperatures, heterogeneous catalysts behave like lossy dielectrics. The technique of impedance spectroscopy has been used in conjunction with other AC methods to differentiate between different loss processes. At low frequencies and high temperatures, thermally activated hopping of relatively free charges is dominant, whilst at higher ...

Electrode polarization is a major problem in the determination of dielectric properties of samples, particularly at low frequencies. Understanding of these interfacial phenomena is essential in order to measure correctly the electrical properties of a sample of interest. This paper presents a comparative study of the effect of electrode contact impedance ...

We report a comparative study of the dielectric properties of solid-state (ceramic method) synthesized NaNbO{sub 3} (NN), Na{sub 0.75}K{sub 0.25}NbO{sub 3} (K25NN), K{sub 0.5}Na{sub 0.5}NbO{sub 3} (KNN) and some composite materials containing In{sub 2}O{sub 3} and NN or KNN using an AC impedance method. Powder X-ray diffraction (PXRD) ...

(Pb0.97Sr0.03)(Zr0.05Ti0.95)O3 nanocrystalline powder was prepared by a solution based chemical method. Preliminary x-ray diffractogram analysis of some aspects of crystal structure showed that a single-phase compound was formed exhibiting a tetragonal system. Impedance spectroscopy study showed the presence of both bulk and grain boundary effects in the ...

The efficiency of imidazole and its derivatives (4-methylimidazole, 4-methyl-5-hydroxymethylmidazone, 1 phenyl-4-methylimidazone, 1-[p-tolyl]-4-methylimidazone) for corrosion inhibition of copper in 0.5 M hydrochloric acid (HCl) was investigated. Corrosion inhibition was studied using impedance spectroscopy and potentiodynamic methods. Polarization ...

Contents: Notes on the Development of Mechanical Impedance, Recent Advances in Mechanical Impedance Inslrumentation and Applications, Mechanical Impedance of Spacecraft Structures, Preliminary Study of an Experimental Method in Multidimensional Mechanical...

A study was made of the magnetotelluric sounding method involving a tensor impedance relationship between the surface electric and magnetic micropulsation fields of the earth. A theoretical treatment of the tensor impedance (including the vertical magneti...

The eduction of the acoustic impedance for liner configurations is ... incidence acoustic impedance measurements using the two-microphone method of ten ...

A linear and direct method of determining the frequency dependent impedance of a 12 pulse HVdc converter is presented. Terms are developed for both the dc and ac side impedances of the converter, including the effect of the firing angle control system, the commutation period, and the variability of the commutation period. The ...

In this study, a bacteria detection apparatus based on dielectrophoretic impedance measurement (DEPIM) method was demonstrated for rapid evaluation of oral hygiene. The authors integrated a micro electrode chip on which bacteria were captured by dielectrophoresis (DEP), an AC voltage source to induce DEP force, and an ...

The transport properties of Nd-doped perovskite materials (La0.7?xNdx)Sr0.3Mn0.7Cr0.3O3 (x?0.30) were investigated using impedance spectroscopy techniques over a wide range of temperatures and frequencies. AC conductance analyses indicate that the conduction mechanism is strongly dependent on temperature and frequency. The DC conductance plots can be ...

In this study, a process for developing nanospring-based electrical biosensors is presented. Impedance spectroscopy is used to characterize silica (SiO2) nanospring-based biosensors. The sensor is a capacitor consisting of two conducting surfaces with silica nanosprings as the dielectric spacer layer. The nanosprings are grown on glass substrates coated ...

... OF A TYPICAL ELECTROMECHANICAL AC VOLTAGE REGULATOR AND POSSIBLE ... Descriptors : *VOLTAGE REGULATORS, DESIGN, TESTS. ...

automatic method for tracking the cavity resonance and impedance match would ... ac motor driving an eccentric crank on its shaft to modulate the stub tuner ...

Impedance measurements are used to detect the end-point for PCR DNA amplification. A pair of spaced electrodes are located on a surface of a microfluidic channel and an AC or DC voltage is applied across the electrodes to produce an electric field. An ion...

The procedure describes the calibration of the General Radio 1650-A impedance bridge. The test instrument measures the inductance and storage factor of inductors, the capacitance and dissipation factor of capacitors, and the ac and dc resistance of all ty...

In the present investigation, Electrochemical Impedance Spectroscopy (EIS) was used ... range of 100 kHz to 0.01 Hz, with 10 mV AC amplitude. ..... Techniques in the Space Transportation System (Space Shuttle) Launch Environment," ...

The main DC and AC characteristics of AC-coupled polysilicon-biased silicon microstrip detectors have been measured in order to determine the set of SPICE parameters of these devices based on a RC network. For this purpose each strip has been divided in 200 unit cells and simulations with 5 and 9 strips have been performed. The model is capable of ...

Mar 1, 2011 ... Development of AC impedance as a method of evaluating solar cell and module .... INORGANIC, ORGANIC AND PHYSICAL CHEMISTRY (9) [x] ...

... Personal Author(s) : Diaz, Carlos ; Urquidi-Macdonald, Mirna ; Macdonald, Digby D. ; Ramamurthy, AC ; van Ooij, Wim J. Report Date : 1993. ...

... any low molecular weight liquid, the polymer ... AC impedance, quartz crystal microbalance gravimetry ... RADICALS, ACETONITRILE, LIQUIDS, WATER ...

... considered in the Natick Traycan Inprovement Program plus the current traycan. ... and the current traycan made of coated tin-free steel as the control. ...

technique and alternating current (ac) impedance spectroscopy provides data on the corrosion resistance of alloys, performance of corrosion inhibitors, ...

Mar 1, 2011 ... AC signal testing included impedance, capacitance and dielectric loss factor of .... A multi-year program, MOST (Mars Optimized Solar Cell ...