... Title : AC IMPEDANCE MEASUREMENT OF ENVIRONMENTAL ... OF INTERFACIAL IMPEDANCE MEASUREMENT ARE ... OF THE METHOD IN ...
DTIC Science & Technology
... 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 ...
... Title : A Corrosion Monitor Based on Impedance Method,. ... were performed on the impedance characteristics of ... the aid of a new ac corrosion monitor. ...
... IS BASED ON AN AC METHOD KNOWN IN ... WHEN AC CURRENT FLOWS THROUGH THE SYSTEM, IT ... LAYER AND AN IMPEDANCE OF THE ...
... Title : APPLYING AC IMPEDANCE ELECTROCHEMICAL METHODS TO CORROSION TESTING COBALT ALLOY MEDIA. Corporate Author : ...
... Title : AC MAGNETIC FIELDS IN THE ... CALCULATIONS OF THE IMPEDANCE OF A ... IS ACCOMPLISHED BY TWO INDEPENDENT METHODS. ...
... Accession Number : ADD854551. Title : AC Impedance Method for High-Resistivity Measurements of Silicon. Descriptive Note : Journal article,. ...
... of a Scanning Electrochemical Impedance Spectroscopy Technique ... This article describes a method of generating ... by driving an ac current between ...
... 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 ...
... inhibition was studied using impedance spectroscopy and potentiodynamic methods. Results obtained from the AC impedance measurements are ...
... METHODS DISCUSSED INCLUDE POSITRON ANNIHILATION, AC- IMPEDANCE SCANNING, SCANNING LASER ACOUSTIC MICROSCOPY ...
... APPLICATION OF COLLOCATION METHODS REDUCES THE ... CRACK IN THE AC FIELD OF A ... AS WELL AS THE IMPEDANCE CHANGES DUE ...
... Title : AC Impedance Analysis of Corrosion Fatigue in Naval Aircraft Alloys. ... this program is to develop rapid electrochemical methods for evaluating ...
... 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 ...
... SAMPLE AND AN AC MAGNETIC FIELD ... FREQUENCY, WHERE IMPEDANCE HERE IS ... THE RECONSTRUCTION METHOD ARE PRESENTED ...
... OF INFLUENCING PARAMETERS BY IMPEDANCE PLANE ANALYSIS ... AC MAGNETOGRAPHY ... A SERIES OF TEST METHODS INTEGRATED IN A ...
... DC AND AC TECHNIQUES WHICH CAN ... THE EXTRAPOLATION METHOD OF TAFEL ... MEASUREMENTS AND IMPEDANCE MEASUREMENTS ...
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 ...
Energy Citations Database
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...
National Technical Information Service (NTIS)
... THE PROBLEM OF THE AC MAGNETIC FIELD ... A LOWER DIMENSION, THE SECOND METHOD FITS BETTER ... OF THE TOTAL IMPEDANCE OF A ...
... In accordance with one method of this invention ... analog voltage which represents the AC component that is phase shifted by the impedance of the ...
... rectifying the AC voltage signals generated by the ... and a source impedance 91 represent the ... Disclosed Method" section, of a transmission line ...
... I Capacitive Behavior in Conducting Polymers: AC Impedance and Quartz Crystal Microbalance Studies by ... AC Impedance Analysis - ...
... ORiGNATIN- AC tIVITy (, po*e -Ithot) 2 I ... between tidal volume and thoracic impedance was determined by analog and digital methods. ...
... frequency dispersion of the impedance is observed ... A method of estimating the true specific ... at gold/solution interface, ac admittance techniques ...
... Using the method of singular perturbations I ... Implementation of an Impedance Boundary Condition ... of Engineering Mathematics, ac- cepted, August ...
... There are two electrochemical methods that are commonly used to monitor the corrosion behaviour of materials: DC Potential and AC Impedance. ...
... 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 ...
... involves the application of a variety of pulses and ac methods with the intention of assigning an aperiodic circuit from electrode impedance analysis ...
... involves the application of a variety of pulse and ac methods with the intention of assigning a periodic circuit from electrode impedance analysis. ...
... presaturated with the corrosion products. An AC impedance technique for the total electrical conductivity, the potentiostatic polarization method for ...
... This study is part of a general development of the ac-impedance method for measurement of the properties of coated metals. (Author). ...
... This requirement vas ac- ... third aspect is the change in impedance, and especially the ... efficiency of buried antennas by theoretical methods has been ...
... systems was necessary. In addition, ways for obtaining corrosion rates from AC impedance methods were investigated. ...
... Title : ANODIC CHARACTERISTICS OF Ni RICH ALLOYS MEASURED BY THE AC IMPEDANCE METHOD,. Corporate Author : ...
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...
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...
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...
... BY DC AN AC ELECTROCHEMICAL TECHNIQUES AS COMPARED ... IMPEDANCE DIAGRAMS SHOW THAT A SLIGHTLY ...
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 ...
NASA Astrophysics Data System (ADS)
... The mechanism for Cu to retard SCC has been investigated by using macro cell method, AC impedance method and ESCA analysis. ...
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 ...
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 ...
NASA Website
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 ...
... input voltage V . An approximate method is then ... ini.aginarV part of tht- assumned AC diodec urrent ... for high-impedance detectors, the detector input ...
The investigation of the mechanism of anodic hydrocarbon oxidation involves the application of a variety of pulse and ac methods with the intention of assigning a periodic circuit from electrode impedance analysis. The applicability of techniques and meth...
... TEMPERATURE RANGE OF 85 DEGREE TO 700 DEGREE C IN DRIED N(2) ATMOSPHERE BY AN AC IMPEDANCE METHOD BETWEEN 120 ...
... The present paper describes a method r~ which enables ... volt- age drop across the impedance n\\ determines ... Tht fact that the ac components of the ...
... From the impedance locis, we obtain resonant frequencies. ... 3. KK Mei, AC Cangellaris, and D. J. Angelakos ... Difference Method," Radio Science, Vol. ...
... Abstract : In an effort to investigate metal surface corrosion and the breakdown of metal protective coatings, the AC Impedance Method was applied ...
... Three methods were originally proposed: measurements of ohmic resistance ... two additional parameters were measured, ac impedance and phase ...
... We will summarize here the basic equations of this method of analysis, which ... Z at any plane along the beam can be called the ac impedance of the ...
... hot corrosion processes at 1173 K. An AC impedance technique for the total electrical conductivity, the potentiostatic polarization method for ionic ...
The investigation of the mechanism of anodic hydrocarbon oxidation involves the application of a variety of pulses and ac methods with the intention of assigning an aperiodic circuit from electrode impedance analysis. The applicability of techniques and m...
Mar 1, 2011 ... Development of AC impedance as a method of evaluating solar cell and module .... INORGANIC, ORGANIC AND PHYSICAL CHEMISTRY (9) [x] ...
... alloy, a basic ship hull material, and painted by different methods. ... The impedance measurements were made with an R-568 ac bridge with a ...
... modulation methods other than ER (eg ... proalv nat duv to the ncrviasng ac modulation but ... impedance path is provided between the two electrodes, a ...
... m/s) has been studied as a function of oxygen concentration using the linear polarization, ac impedance, and potential step methods for measuring ...
Aug 16, 2004 ... ments into electrical energy in the form of AC signal, the ..... tive method would be to take impedance measurements ...
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 ...
Several embodiments for determining the state of charge of a cell or battery are disclosed. In accordance with one method of this invention, an ac voltage is applied to a cell or battery through a shunt. The phase angle between the ac voltage across the battery terminals and the ac current through the battery ...
An improved apparatus and method reduce the harmonic content of AC line and neutral line currents in polyphase AC source distribution networks. The apparatus and method employ a polyphase Zig-Zag transformer connected between the AC source distribution network and a load. The apparatus and ...
DOEpatents
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...
When unbalanced fault occurs in the ac system, the dc system becomes short circuited due to the inverter commutation failure caused by the unbalanced voltage. If the unbalancing factor is small or if the commutation failure is restored immediately due to the damping action, the system continues to operate at the unbalanced condition according to the ac ...
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...
The electrical conductivity of double stranded DNA is investigated with ac impedance spectroscopy. Atomic force microscopy is used to provide images of the DNA molecules stretched over some gap electrodes through a flow cell. More stretched DNA molecules result in smaller charge-transfer resistances in the ac ...
This article describes methods for finding turn-to-turn shorts in rotors of electrical generators. Locating such shorts can be accomplished by comparing the DC resistance or AC impedance of field coils. The experiences of two utilities with the latter method are discussed.
... lanthanum manganate (LSM, La0.8Sr0.2MnO3)-based pasted cathodes were assessed by DC polarization and AC complex impedance methods. ...
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 ...
PubMed
... Title : CHARACTERISTICS OF THE IMPEDANCE METHOD OF INSPECTION AND OF IMPEDANCE INSPECTION TRANSDUCERS. ...
... 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 ...
Various a.c. methods which can localize faults in portable trailing cables and other cables are considered. They include the Murray Loop, capacitance value measurement, inductance measurement, phase comparison recordings, and standing wave measurement. Judgments regarding suitability rank of the various methods were not attempted; ...
The impedance of the epigastrium to a 4 mA, 100 KHz AC current increases while liquids of low electrical conductivity are being drunk. Logically, the decline which follows occurs as the liquid leaves the stomach. This impedance measurement of gastric emptying proved comparable with the dye dilution method. In a ...
PubMed Central
... 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 ...
... 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 ...
In order to characterize semihydrophobic teflon-bonded oxygen (air) electrodes an AC-impedance method was applied by using a Transfer Function Analyser. The impedance of these electrodes was measured at various working conditions in the frequency domain between 10 KHz and 1 mHz. From the impedance spectra obtained ...
... electrochemistry of titanium in the LiCl-KCl eutectic melt has been investigated by means of pulse techniques and ac impedance measurements. ...
... 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,. ...
... Abstract : Although ac impedance has come to prominence lately for studying anti ... At first sight this is surprising since the techniques are very ...
... Accession Number : ADA428218. Title : AC Impedance Testing on 40-Ah Li-Ion Cells. Descriptive Note : Technical rept. ...
... Title : AC IMPEDANCE INVESTIGATION OF TA(2)O(5) FILM FOR USE AS A STORAGE CAPACITOR DIELECTRIC. Corporate Author : ...
A highly sensitive non-destructive method employing a scanning technique is described for sensing variations in metal surfaces in aqueous environments, using ac impedance. The probe consisted of a dual compartment with two orifices passing through its bas...
capacity to form a capacitive 400-cycle ac voltage divider as shown in ... Output impedance. Power. Supply voltage. Accuracy. Value of fixed capacitance. Data sampled ... This method of gaging works well for single-phase fluids in any ...
... E-mail: * mtaguchi@net.nagasaki-u.ac.jp ... of moment, Micro-Stripes based on TLM method. Its input impedance characteristics are compared with ...
In-situ measurement of corrosion rate of Zircaloy-4 was tested by applying AC-impedance method in 300degC water in a static autoclave. Impedance data of surface oxide layer of sample were obtained by the Frequency Response Analysis Method and converted in...
Flow-through porous electrodes, such as packed-bed and fluidized-bed electrodes, are attractive for electrowinning, electro-organic synthesis and flow-battery applications. The extensive surface area of the porous electrodes makes high volumetric reaction rate more possible than in a cell with smooth electrodes. Forced convection also enhances mass-transfer rate and hence reduces concentration ...
... jUN 0 91994D * F ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY OF ... 16. PRICE COOE ac-Impedance, Chromate, Aluminum Alloys 17. ...
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 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 ...
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 ...
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 the electrode, to the applied potential is measured as a ...
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 ...
A numerical procedure is given to determine the static charge configuration and electrical impedance of a circular pool of electrons on the surface of liquid helium. The response for an ac Corbino probe is obtained for arbitrary frequency. By fitting the results to audiofrequency capacitance-conductance data the local charge density and electric field ...
In the present investigation, holographic interferometry was utilized for the first time to measure the alternating current (A.C.) impedance of aluminum samples during the initial stage of anodization processes in aqueous solution without any physical contact. The anodization process (oxidation) of the aluminum samples was carried out chemically in ...
... 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 ...
For research and development of the solid oxide fuel cell (SOFC), it is very important to develop diagnostic tools that can grasp detailed cell performance characteristics. The a.c. impedance analysis is one of the indispensable methods for this purpose. The authors, therefore, perform time-dependent numerical simulations for a planar ...
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 ionically labeled probe will attach to a complementary DNA segment, and a polymerase enzyme will release ...
DOE Information Bridge
This article describes a new measurement technique that utilizes impedance spectroscopy for the characterization of thermoelectric materials and devices. Two circuit models were developed and used to help explain the impedance spectroscopy data using transmission line theory and a coupled electrothermal model. Two testing configurations have been ...
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...
An ac impedance method was used to determine apparent diffusion coefficients associated with the oxidation of polypyrrole. This method was applied to the reduced (nonconductive) form of the polymer, and the polymer remained in the nonconductive state throughout the duration of the experiment. Apparent diffusion ...
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 ...
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 ...
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 ...
A bipolar pulse DC resistance measurement modified for use in electrical impedance tomography is presented. The measurement method compensates for offset voltages, which usually exist between electrodes. The absence of phase shifts as encountered in AC systems using sinusoidal excitation greatly simplifies the measurement. For low to ...
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 ...
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 impedance of ...
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 fiber-reinforced ...
The impedance spectrum test was employed for detection of short circuits within Wendelstein 7-X (W7-X) superconducting magnetic field coils. This test is based on measuring the complex impedance over several decades of frequency. The results are compared to predictions of appropriate electrical equivalent circuits of coils in different production states or ...
Time quantity one-cycle control method is proposed in this paper for unity power-factor ac-dc converters. Converters controlled by this method operate at constant switching frequency, require no current sensing, have a simple control circuit, and exhibit resistive input impedance at the ac ...
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 ...
