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1997

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Articles 1201 - 1230 of 2472

Full-Text Articles in Physical Sciences and Mathematics

The Columbia Slough, Scott A. Wells Mar 1997

The Columbia Slough, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

This report was written in an attempt to provide the public and Bureau of Environmental Services Staff with a summary of work accomplished on the Columbia Slough system by Portland State University and other consultants working on the Slough over the last 6 years. An attempt was made to create an easy-to-read report with important overviews of the "big picture", glossary of definitions, index, and further details to assist in technology transfer.

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Morphology-Dependent Resonances Of An Infinitely Long Circular Cylinder Illuminated By A Diagonally Incident Plane Wave Or A Focused Gaussian Beam, James A. Lock Mar 1997

Morphology-Dependent Resonances Of An Infinitely Long Circular Cylinder Illuminated By A Diagonally Incident Plane Wave Or A Focused Gaussian Beam, James A. Lock

Physics Faculty Publications

The S matrix for scattering a diagonally incident focused Gaussian beam by an infinitely long circular cylinder is calculated, and the diagonal and off-diagonal elements of the matrix are physically interpreted. In addition, the TE and TM morphology-dependent resonances of the cylinder for plane-wave incidence are examined, and it is found that the cylinder size parameter at resonance increases as the angle of incidence of the plane wave increases. The size parameter increase is explained in terms of the heuristic model of morphology-dependent resonances. The presence of both TE and TM resonances in each of the epsilon-polarized and mu-polarized partial-wave …

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A Validation Study Of The Ssm/I Temperature Algorithm And Comparison With The Cal/Val Land Surface Temperatures, Ronald L. Comoglio Mar 1997

A Validation Study Of The Ssm/I Temperature Algorithm And Comparison With The Cal/Val Land Surface Temperatures, Ronald L. Comoglio

Theses and Dissertations

The USAF operational cloud model, the Real-Time Nephanalysis (RTNEPH), requires infrared and visual scene scans as well as input from the Special Sensor Microwave Imager (SSM/I), featured on the Defense Meteorological Satellite Program (DMSP) polar orbiters. Additionally, SSM/I provides input to the Air Force Global Weather Center (AFGWC) surface temperature model (SFCTMP). The global surface temperatures are required for identifying which pixel of a scene is cloud and which is ground and as a first guess input to initialize NWP models. The SSM/I provides brightness temperatures sampled at four discrete: frequencies and dual polarizations to produce surface temperatures. Two algorithms …

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Optimization Of The Velocity Azimuth Display (Vad) Algorithm's Adaptable Parameters In The Wsr-88d System, Donald R. Farris Mar 1997

Optimization Of The Velocity Azimuth Display (Vad) Algorithm's Adaptable Parameters In The Wsr-88d System, Donald R. Farris

Theses and Dissertations

Meteorologists have encountered problems with the Velocity Azimuth Display (VAD) algorithm in the Weather Surveillance Radar - 1988 Doppler (WSR-88D) System. Under certain meteorological conditions, forecasters have observed differences between the radar's wind profiles and wind profiles from rawinsonde upper-air soundings, or wind profilers. One of the main causes of this problem is inversions in the atmosphere which cause the radar beam to subrefract or superefract, causing the VAD winds to be inaccurately reported at a particular height. This thesis used the WSR-88D Algorithm Testing and Display System (WATADS) to compare VAD winds from recorded Level 2 NEXRAD data at …

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A Comparison Of Circular Error Probable Estimators For Small Samples, Charles E. Williams Mar 1997

A Comparison Of Circular Error Probable Estimators For Small Samples, Charles E. Williams

Theses and Dissertations

Several previous studies investigated the performance of competing circular error probable (CEP) estimators for small samples. This estimation is important in ICBM analysis because, due to expense, there are a limited number of ICBM test launches. In the most recent previous study (1993), Tongue considered five CEP estimators in a simulation test, attempting to determine the behavior of these estimators for populations of various bias, ellipticity, correlation, and sample size. In this paper, we build on Tongue's findings in three ways: (1) The number of estimators compared is expanded to eight. (2) Different factors and factor levels are used. (3) …

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Automatic Digital Processing For Calibration Data Of Open Skies Treaty Sensors, Donna D. Keating Mar 1997

Automatic Digital Processing For Calibration Data Of Open Skies Treaty Sensors, Donna D. Keating

Theses and Dissertations

The Open Skies Treaty provides guidelines allowing participants to fly in air space over other participants' countries to monitor strategic military placement and development. The treaty restricts the ground size of the smallest detail recorded by these aerial imaging systems to any size larger than 30 cm. This restriction is enforced by placing a lower limit on the altitude at which a participating aircraft can fly and it is computed as the value of Hmin. Current techniques rely on human photographic interpreters to select the value of Hmin for every calibration pass and is very resource intensive. The Open Skies …

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An Atmospheric Sensitivity And Validation Study Of The Variable Terrain Radio Parabolic Equation Model (Vtrpe), Matthew K. Doggett Mar 1997

An Atmospheric Sensitivity And Validation Study Of The Variable Terrain Radio Parabolic Equation Model (Vtrpe), Matthew K. Doggett

Theses and Dissertations

The Variable Terrain Radio Parabolic Equation (VTRPE) computer model is a powerful and flexible program that provides calculations of the radar propagation conditions of the atmosphere. It is limited however, by the accuracy and resolution of the input data. This study quantifies the sensitivity of the VTRPE model to the accuracy and resolution of the atmospheric parameters that go into it. Also, two case studies are examined to test the utility of VTRPE in operational use. The sensitivity to measurements of pressure, temperature, and humidity was found to be dependent on the meteorological environment. In standard and subrefractive environments, average …

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Three-Body Dispersion Coefficients For Alkali-Metal Atoms, Mircea Marinescu, Anthony F. Starace Mar 1997

Three-Body Dispersion Coefficients For Alkali-Metal Atoms, Mircea Marinescu, Anthony F. Starace

Anthony F. Starace Publications

We study the nonadditive part of the long-range interaction among three alkali-metal atoms in their ground states. Using nondegenerate perturbation theory, up to the third order, we have computed the dispersion coefficients C for three alkali-metal atoms interacting via their electric dipole moments. Both heteronuclear and homonuclear cases are considered. The numerical values for the C coefficients suggest that such three-body dipole interaction effects may not be neglected in the description of the long-range surface potential interaction for alkali-metal atoms. Furthermore, we show that approximate formulas for C of Midzuno and Kihara [J. Phys. Soc. Jpn. 11, 1045 (1956)] give …

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Status Of The Major Oyster Diseases In Virginia 1996 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson Mar 1997

Status Of The Major Oyster Diseases In Virginia 1996 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson

Reports

No abstract provided.

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Salinity And Hydrology Of The Wamballup Swamp Catchment, R Ferdowsian, A T. Ryder Mar 1997

Salinity And Hydrology Of The Wamballup Swamp Catchment, R Ferdowsian, A T. Ryder

Resource management technical reports

No abstract provided.

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Enclaves In The Cadillac Mountain Granite (Coastal Maine): Samples Of Hybrid Magma From The Base Of The Chamber, R. A. Wiebe, Diane R. Smith, M. Sturm, E. M. King, M. S. Seckler Mar 1997

Enclaves In The Cadillac Mountain Granite (Coastal Maine): Samples Of Hybrid Magma From The Base Of The Chamber, R. A. Wiebe, Diane R. Smith, M. Sturm, E. M. King, M. S. Seckler

Geosciences Faculty Research

The Cadillac Mountain intrusive complex is dominated by the Cadillac Mountain granite and a 2–3 km thick section of interlayered gabbroic, dioritic and granitic rocks which occurs near the base of the granite. The layered rocks record hundreds of injections of basaltic magma that ponded on the chamber floor and variably interacted with the overlying silicic magma. Magmatic enclaves, ranging in composition from 55 to 78 wt % SiO2, are abundant in granite above the layered mafic rocks. The most mafic enclaves are highly enriched in incompatible elements and depleted in compatible elements. Their compositions can be best …

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Development And Implementation Of An Isentropic Potential Vorticity Algorithm For Use At Air Force Global Weather Center, Jay B. Desjardins Jr. Mar 1997

Development And Implementation Of An Isentropic Potential Vorticity Algorithm For Use At Air Force Global Weather Center, Jay B. Desjardins Jr.

Theses and Dissertations

This thesis presents and validates methods for calculating isentropic potential vorticity (IPV) and applies these methods in software programs planned for implementation at the Air Force Global Weather Center (AFGWC). The IPV programs will provide Air Force Weather forecasters additional tools to diagnose atmospheric kinematics and understand atmospheric dynamics. A FORTRAN program is recommended using mandatory-level isobaric data projected to be available on AFGWC computer systems, specifically, from the Navy Operational Global Atmosphere Prediction System and Medium Range Forecast models. Program development and analysis consists of three main steps: (1) data retrieval; (2) IPV calculations; and, (3) interpolation to an …

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Moisture Sensitivity Of Contrail Forecast Algorithms, Allen C. Rabayda Mar 1997

Moisture Sensitivity Of Contrail Forecast Algorithms, Allen C. Rabayda

Theses and Dissertations

This thesis looked at using new relative humidity (RH) climatologies to improve the Air Force Global Weather Center's (AFGWC) contrail forecasts. To study the effect of the new RH climatolgies, the currently used empirical relative humidity (RH) profile is replaced with a more accurate climatological one, the Stratospheric And Gaseous Experiment II (SAGE II). The study begins by examining accuracy and bias of forecast contrail bases generated by the empirical and SAGE II RH profiles on 42 days. Both sets of forecast bases are shown to be statistically similar with a series of hypothesis tests. Additional RH profiles, from 0% …

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Composting Landscape Waste From The University Of Nevada, Las Vegas, K. Jill Hammond Mar 1997

Composting Landscape Waste From The University Of Nevada, Las Vegas, K. Jill Hammond

UNLV Theses, Dissertations, Professional Papers, and Capstones

The University of Nevada, Las Vegas is a major producer of organic waste in the Las Vegas Valley. Composting landscape wastes is one way to reduce both landfill dumping and fertilizer costs for the university. It is also an environmentally friendly means of curbing a nationwide problem: unnecessary use of landfill space. Three sites within Clark County were analyzed for the feasibility of composting: Frenchman Mountain, UNLV Campus, and Boulder City Landfill. Using cost analysis, water availability, and other factors to analyze each site, Boulder City Landfill appears to be the best place to house UNLV's composting operation. Composting in …

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Memorandum Of Understanding Between The Commissioner For Soil And Land Conservation, Environmental Protection Authority, Department Of Environmental Protection, Agriculture Western Australia, Department Of Conservation And Land Management, Water And Rivers Commission For The Protection Of Remnant Vegetation On Private Land In The Agricultural Region Of Western Australia, Department Of Agriculture And Food, Western Australia, Western Australia. Commissioner Of Soil And Land Conservation, Western Australia. Environmental Protection Authority, Western Australia. Dept. Of Environmental Protection, Western Australia. Dept. Of Conservation And Land Management, Western Australia. Water And Rivers Commission Mar 1997

Memorandum Of Understanding Between The Commissioner For Soil And Land Conservation, Environmental Protection Authority, Department Of Environmental Protection, Agriculture Western Australia, Department Of Conservation And Land Management, Water And Rivers Commission For The Protection Of Remnant Vegetation On Private Land In The Agricultural Region Of Western Australia, Department Of Agriculture And Food, Western Australia, Western Australia. Commissioner Of Soil And Land Conservation, Western Australia. Environmental Protection Authority, Western Australia. Dept. Of Environmental Protection, Western Australia. Dept. Of Conservation And Land Management, Western Australia. Water And Rivers Commission

All other publications

Memorandum -- Schedule 1. Statutory requirements -- Schedule 2. Area covered by this memorandum -- Schedule 3. Assessment critieria -- Schedule 4. Assessment manuals: Supporting manual 4.2. Deprtment of Environmental Protection. Environmental evaluation of native vegetation in the wheatbelt of Western Australia -- Supporting manual 4.3. Agriculture Western Australia. Procedures for the administration of clearing and protection of native vegetation in Western Australia -- Supporting manual 4.4. Water and R
onmental impact assessment -- Schedule 8. Adjustment measures.

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The Peculiar Motions Of Early‐Type Galaxies In Two Distant Regions. Iv. The Photometric Fitting Procedure, R. P. Saglia, Edmund Bertschinger, G. Baggley, David Burstein, Matthew Colless, Roger L. Davies, Robert K. Mcmahan Jr., Gary Wegner Mar 1997

The Peculiar Motions Of Early‐Type Galaxies In Two Distant Regions. Iv. The Photometric Fitting Procedure, R. P. Saglia, Edmund Bertschinger, G. Baggley, David Burstein, Matthew Colless, Roger L. Davies, Robert K. Mcmahan Jr., Gary Wegner

Dartmouth Scholarship

The EFAR project is a study of 736 candidate early-type galaxies in 84 clusters lying in two regions toward Hercules-Corona Borealis and Perseus-Cetus at distances cz ≈ 6000-15,000 km s-1. In this paper we describe a new method of galaxy photometry adopted to derive the photometric parameters of the EFAR galaxies. The algorithm fits the circularized surface brightness profiles as the sum of two seeing-convolved components, an R1/4 and an exponential law. This approach allows us to fit the large variety of luminosity profiles displayed by the EFAR galaxies homogeneously and to derive (for at least a …

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Far-Ultraviolet Absorption Lines In The Remnant Of Sn 1006, Chi-Chao Wu, D. Michael Crenshaw, Andrew J. S. Hamilton, Robert A. Fesen Mar 1997

Far-Ultraviolet Absorption Lines In The Remnant Of Sn 1006, Chi-Chao Wu, D. Michael Crenshaw, Andrew J. S. Hamilton, Robert A. Fesen

Dartmouth Scholarship

We have obtained a far-ultraviolet spectrum (1150-1600 Å) of a hot subdwarf star behind the remnant of supernova 1006 with the Faint Object Spectrograph (FOS) on the Hubble Space Telescope. The high-quality spectrum is used to test previous identifications of the strong absorption features discovered with the International Ultraviolet Explorer. These features have FWHM = 4000 (±300) km s-1 and are not at the rest wavelengths of known interstellar lines, as opposed to the broader (~8000 km s-1 FWHM) Fe II lines from the remnant centered at 0 km s-1 in near-UV FOS spectra. We …

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Post-Surgical Passive Response Of Local Environment To Primary Tumor Removal, J. A. Adam, C. Bellomo Mar 1997

Post-Surgical Passive Response Of Local Environment To Primary Tumor Removal, J. A. Adam, C. Bellomo

Mathematics & Statistics Faculty Publications

Prompted by recent clinical observations on the phenomenon of metastasis inhibition by an angiogenesis inhibitor, a mathematical model is developed to describe the post-surgical response of the local environment to the “surgical” removal of a spherical tumor in an infinite homogeneous domain. The primary tumor is postulated to be a source of growth inhibitor prior to its removal at t = 0; the resulting relaxation wave arriving from the disturbed (previously steady) state is studied, closed form analytic solutions are derived, and the asymptotic speed of the pulse is estimated to be about 2 × 10−4 cm/sec for the …

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Cascade Artmap: Integrating Neural Computation And Symbolic Knowledge Processing, Ah-Hwee Tan Mar 1997

Cascade Artmap: Integrating Neural Computation And Symbolic Knowledge Processing, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

This paper introduces a hybrid system termed cascade adaptive resonance theory mapping (ARTMAP) that incorporates symbolic knowledge into neural-network learning and recognition. Cascade ARTMAP, a generalization of fuzzy ARTMAP, represents intermediate attributes and rule cascades of rule-based knowledge explicitly and performs multistep inferencing. A rule insertion algorithm translates if-then symbolic rules into cascade ARTMAP architecture. Besides that initializing networks with prior knowledge can improve predictive accuracy and learning efficiency, the inserted symbolic knowledge can be refined and enhanced by the cascade ARTMAP learning algorithm. By preserving symbolic rule form during learning, the rules extracted from cascade ARTMAP can be compared …

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Object Matching Using The Dynamic Programming Algorithm, Rhoda Baggs Koss Mar 1997

Object Matching Using The Dynamic Programming Algorithm, Rhoda Baggs Koss

Theses and Dissertations

A new algorithm for matching objects between images is developed and investigated. Affine transformations, i.e. those with translation, rotation, scaling and shearing between images are considered. Steps along the way include segmentation of the 2 images (referred to as the reference and inspected images), contour tracing of each segment/object in each image, the creation of objects via a new object representation scheme known as length codes (developed in [3]), and the application of the new dynamic warping algorithm. New original concepts include the use of the dynamic warping algorithm on sequences of length codes in order to determine the k …

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Small Scale Electronic Transport In Diamond Microcrystals., M. Jaeger, S. Hyun, Anthony Day, M. Thorpe, B. Golding Feb 1997

Small Scale Electronic Transport In Diamond Microcrystals., M. Jaeger, S. Hyun, Anthony Day, M. Thorpe, B. Golding

Anthony Roy Day

The interpretation of electronic transport in polycrystalline diamond has proven difficult as a result of the disorder arising from physical and chemical inhomogeneities. We describe experimental methods, based on electron beam lithography, for studying transport in single crystallites grown by CVD on Si substrates. The electrical contacting process utilizes the flexibility of the scanning electron microscope to write metallic contacts to individual crystallites with lateral dimensions of a few μm. A detailed analysis of the current distribution in the crystals allows us to extract the electronic conductivity from arbitrarily shaped, faceted crystals.

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Minimal Dynamical Triangulations Of Random Surfaces, Simon Catterall, Mark Bowick, Gudmar Thorleifsson Feb 1997

Minimal Dynamical Triangulations Of Random Surfaces, Simon Catterall, Mark Bowick, Gudmar Thorleifsson

Physics - All Scholarship

No abstract provided.

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Minimal Dynamical Triangulations Of Random Surfaces, Mark Bowick, Simon Catterall, Gudmar Thorleifsson Feb 1997

Minimal Dynamical Triangulations Of Random Surfaces, Mark Bowick, Simon Catterall, Gudmar Thorleifsson

Physics - All Scholarship

We introduce and investigate numerically a minimal class of dynamical triangulations of two-dimensional gravity on the sphere in which only vertices of order five, six or seven are permitted. We show firstly that this restriction of the local coordination number, or equivalently intrinsic scalar curvature, leaves intact the fractal structure characteristic of generic dynamically triangulated random surfaces. Furthermore the Ising model coupled to minimal two-dimensional gravity still possesses a continuous phase transition. The critical exponents of this transition correspond to the usual KPZ exponents associated with coupling a central charge c=1/2 model to two-dimensional gravity.

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On Some Problems Related To Hermite And Laguerre Expansions., P. K. Ratnakumar Dr. Feb 1997

On Some Problems Related To Hermite And Laguerre Expansions., P. K. Ratnakumar Dr.

Doctoral Theses

The first three chapters of this thesis are concerned with the spherical means associated to the Hermite and Laguerre expansions. The study of spherical means has a very long history. The classic work of F. John deals with various applications of the spherical means to the theory of partial differential equations. They entered Fourier analysis with the celebrated theorem of E. Stein on spherical analogue of the Lebesgue differentiation theorem. Ever since they have appcared again and again in several areas of analysis like integral geometry, inversion of Fourier transforms and related arcas.

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The Fixed Point Index As A Local Lefschetz Number., Neeta Pandey Dr. Feb 1997

The Fixed Point Index As A Local Lefschetz Number., Neeta Pandey Dr.

Doctoral Theses

In this thesis we defitne a class of self maps of connected compact polyhodza - those which prmserve erpanding directions - and define the fixed point indices of such maps at an isolated set of fixed points of the map as a local Lefschets rumber. Our definition uses simplicial approximations of the given map in the spirit of O Nell (I19| and Fournier (71) and is intrinsic so that it is computable.Let X be a connected compact polyhedron and f:X→ X be a map an X. The Lefscheta number L() of / is then defined to be ([13]),L) -E(-1)jTrace {, …

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On The Power Of Multi-Objects, Prasad Jayanti, Sanjay Khanna Feb 1997

On The Power Of Multi-Objects, Prasad Jayanti, Sanjay Khanna

Computer Science Technical Reports

In the standard ``single-object'' model of shared-memory computing, it is assumed that a process accesses at most one shared object in each of its steps. In this paper, we consider a more powerful variant---the ``multi-object'' model---in which each process may access *any* finite number of shared objects atomically in each of its steps. We present results that relate the synchronization power of a type in the multi-object model to its synchronization power in the single-object model. Although the types fetch&add and swap have the same synchronization power in the single-object model, Afek, Merritt, and Taubenfeld showed that their synchronization powers …

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Problems Of The Study Of Anodic Films On Pb In Sulfuric Acid Solution(Ⅲ), Houtian Liu, Qunzhou Wang, Weifang Zhou Feb 1997

Problems Of The Study Of Anodic Films On Pb In Sulfuric Acid Solution(Ⅲ), Houtian Liu, Qunzhou Wang, Weifang Zhou

Journal of Electrochemistry

The interstitial liquid among the particles in anodic Pb(Ⅱ) films could be the major passage for ion transportation. This is discussed with the mechanism of the cathodic reduction of anodic PbSO 4 film and the effect of Sb on the growth of anodic Pb(Ⅱ) oxides film.

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Studies On An Iron Heteropolyacid Redox Flow Battery, Peiju Gu Yuanpeng Sun, Wansheng You, Zhorgyin Tan Feb 1997

Studies On An Iron Heteropolyacid Redox Flow Battery, Peiju Gu Yuanpeng Sun, Wansheng You, Zhorgyin Tan

Journal of Electrochemistry

This paper reports a new Fe HP redox flow cell. The positive and negative electrodes active materials are phosphomolybdic acid and acidified ferrous sulphate solutions respectively. Two activated porous carbon felt electrodes where the electrochemical reactions take place, are separated by a selective cation exchange membrane. The both couples have a suitable electrochemical reversibility on carbon and graphite electrodes. The active materials of the cell have very high stability. Moreover the cell has no life cycle limiting.

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Electrochemical Synthesis And Characterization Of Ba Pb O And Bi Pb O Oxides, Min Zhao Liangzhong Xie, Cuiying Xu, Jinbiao Zhang Feb 1997

Electrochemical Synthesis And Characterization Of Ba Pb O And Bi Pb O Oxides, Min Zhao Liangzhong Xie, Cuiying Xu, Jinbiao Zhang

Journal of Electrochemistry

Pb based oxides Ba Pb O and Bi Pb O were synthesized from aqueous solutions by using electrochemical method. The resulting Ba Pb O and Bi Pb O were characterized using XPS, EDX and XRD. The results show that perovskite BaPb 0.9 O 3 can be electrodeposited on the anode only from strong alkaline solution. In acid aqueous solution, conducting BiPb 2O z oxide is fromed on the anode. In these oxides the nominal valence of lead is +4.

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Electrochemical Studies Of Spinel Limn 2o 4 Rechargeable Lithium Battery, Li Feng, Yuqin Wu Lie Chang, Hong Li, Yibin San, Tianhong Lu Feb 1997

Electrochemical Studies Of Spinel Limn 2o 4 Rechargeable Lithium Battery, Li Feng, Yuqin Wu Lie Chang, Hong Li, Yibin San, Tianhong Lu

Journal of Electrochemistry

The spinel Li intercalation compound LiMn 2O 4 was prepared and studied using ac impedance and cyclic voltammogram techniques. It was first discussed that the impedance behaviors of LiMn 2O 4 electrode varied as lithium ion was intercalated in or out the electrode with the help of fractal theory. The Li reversible behaviors in LiMn 2O 4 electrode were shown by the cyclic voltammogram results.

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