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Description of a Dropping Mercury Polaroscope

Description: Abstract: " The construction and operation of a dropping mercury polaroscope developed by Quentin A. Kerns is described herein. With this polaroscope a Heyrovsky polarogram is automatically produced on the screen of a cathode ray tube during the formation of each drop at the tip of a dropping mercury electrode, a change in the resistance of the cell operates to initiate the generation of a voltage wave to be applied to the cell during the formation of the next drop during a predetermined fractional portion of the average drop formation period."
Date: 1952
Creator: U.S. Atomic Energy Commission
Partner: UNT Libraries Government Documents Department

The Mechanism of Failure in Corona Discharge

Description: Abstract: "Experimental evidence is given which indicates that electronic bombardment is responsible for damage and failure of insulating material subjected to intense corona attack. The experimental revolts are further supported by some theoretical considerations of the energy-time properties of corona discharges."
Date: September 1, 1957
Creator: Nail, Clelland D.
Partner: UNT Libraries Government Documents Department

Complex band structure under plane-wave nonlocal pseudopotential Hamiltonian of metallic wires and electrodes

Description: We present a practical approach to calculate the complex band structure of an electrode for quantum transport calculations. This method is designed for plane wave based Hamiltonian with nonlocal pseudopotentials and the auxiliary periodic boundary condition transport calculation approach. Currently there is no direct method to calculate all the evanescent states for a given energy for systems with nonlocal pseudopotentials. On the other hand, in the auxiliary periodic boundary condition transport calculation, there is no need for all the evanescent states at a given energy. The current method fills this niche. The method has been used to study copper and gold nanowires and bulk electrodes.
Date: July 17, 2009
Creator: Yang, Chao
Partner: UNT Libraries Government Documents Department

Characterization of SEI layers on LiMn2O4 cathodes with in-situ spectroscopic ellipsometry

Description: In situ spectroscopic ellipsometry was employed to study the initial stage of SEI layer formation on thin-film LiMn{sub 2}O{sub 4} electrodes. It was found that the SEI layer formed immediately upon exposure of the electrode to EC/DMC (1:1 by vol) 1.0 M LiPF{sub 6} electrolyte. The SEI layer thickness then increased in proportion to a logarithmic function of elapsed time. In comparison, the SEI layer thickness on a cycled electrode increased in proportion to a linear function of the number of cycles.
Date: August 30, 2004
Creator: Lei, Jinglei; Li, Lingjie; Kostecki, Robert; Muller, Rolf & McLarnon, Frank
Partner: UNT Libraries Government Documents Department

TURN-BY-TURN ANALYSIS OF PROTON AND GOLD BEAMS AT INJECTION IN THE AGS BOOSTER.

Description: In this paper we describe the latest version of a program we have used for several years to acquire and analyze turn-by-turn data from pick-up electrodes in the AGS Booster during injection. The program determines several parameters of the injected beam including the tunes and the position and angle of the incoming beam. Examples are given for both proton and gold injection.
Date: March 29, 1999
Creator: GARDNER,C.; AHRENS,L. & WILLIAMS,N.
Partner: UNT Libraries Government Documents Department

Determination of S-112 and Mock Tank Electrical Resistivities using Numerical Forward and Inverse Solutions

Description: The purpose of this work is to establish the electrical similarity of the Mock Tank site to S-112 tank site to determine if the Mock Tank requires modifications for the tests this summer. We accomplish this objective by determining the effective electrical resistivity of S-112 and comparing it with that of the Mock Tank. We also compare the expected sensitivities under S-112 and Mock Tank assuming that long electrodes are used.
Date: May 1, 2002
Creator: Ramirez, A & Daily, W
Partner: UNT Libraries Government Documents Department

The Determination of T at the Dropping Mercury Electrode in Hex Plant Ammonia and Peroxide Decantrates

Description: Inroduction: "A study of the literature, particularly the work done by R. Strubl, I.W. Kolthoff and S.B. Smith, indicated that a polargraphic method for the estimation of T could be devised which would not sacrifice reasonable accuracy for rapidity. Work was begun with the intention of developing such a method."
Date: January 16, 1945
Creator: Kwiatkowski, S.; Owens, J. & Casto, C. C.
Partner: UNT Libraries Government Documents Department

Sensor for cell signaling proteins.

Description: Thiolated cyclodextrins have been shown to be useful as modifiers of electrode surfaces for application in electrochemical sensing. The adsorption of three different thiolated {beta}-cyclodextrin ({beta}-CD) derivatives onto gold (Au) electrodes was studied by monitoring ferricyanide reduction and ferrocene carboxylic acid (FCA) oxidation at the electrode surface using cyclic voltammetry. Electrodes modified with the {beta}-CD MJF-69 derivative bound FCA within the CD cavity. The monolayer acted as a conducting layer with an increase in the oxidation current. On the other hand, the {beta}-CD layer inhibited the reduction of ferricyanide at the electrode surface since ferricyanide is larger than the cavity of the {beta}-CD derivative and thus unable to form an inclusion complex.
Date: December 1, 2005
Creator: Farrow, Matthew & Yelton, William Graham
Partner: UNT Libraries Government Documents Department

Reduction of sample volume and waste generation in acid/base titrations using microelectrodes

Description: The Analytical Development Section (ADS) has developed microelectrode methods for use with pH titrations and pH determinations. These microelectrode methods offer increased sensitivity and enable analyses to be done with smaller sample and buffer volumes than are used with standard size electrodes. This report establishes the technical validity of the methods and describes the application of these methods to decreased detection limits, decreased waste generation, and decreased radiation exposure.
Date: March 22, 1996
Creator: Ekechukwu, A.A.
Partner: UNT Libraries Government Documents Department

Multiple Input Electrode Gap Control During Vacuum Arc Remelting

Description: Accurate control of the electrode gap in a vacuum arc remelting (VAR) furnace has been a goal of melters for many years. The size of the electrode gap has a direct influence on ingot solidification structure. At the high melting currents (30 to 40 kA) typically used for VAR of segregation insensitive Ti and Zr alloys, process voltage is used as an indicator of electrode gap, whereas drip-short frequency (or period) is usually used at the lower currents (5 to 8 kA) employed during VAR of superalloys. Modem controllers adjust electrode position or drive velocity to maintain a voltage or drip-short frequency (or period) set-point. Because these responses are non-linear functions of electrode gap and melting current, these controllers have a limited range for which the feedback gains are valid. Models are available that relate process voltage and drip-short frequency to electrode gap. These relationships may be used to linearize the controller feedback signal. An estimate of electrode gap may then be obtained by forming a weighted sum of the independent gap estimates obtained from the voltage and drip-short signals. By using multiple independent measures to estimate the gap, a controller that is less susceptible to process disturbances can be developed. Such a controller was designed, built and tested. The tests were carried out at Allvac Corporation during VAR of 12Cr steel at intermediate current levels.
Date: January 14, 1999
Creator: Beaman, J.J.; Hysinger, C.L.; Melgaard, D.K. & Williamson, R.L.
Partner: UNT Libraries Government Documents Department

Advanced nickel-metal hydride cell development. Final report, September 1993--March 1996

Description: Inert gas atomization using metal hydride alloys for a Ni/MH{sub x}cell was studied. Atomization of the alloys was demonstrated on a small production scale up to batch size of several kg. Relative performance of the atomized and nonatomized alloys was investigated for the electrode material in a Ni/MH{sub x} cell. The study included effects of charge-discharge rates, temperature, and particle size on cell voltage (polarization) and specific capacity. Results show that the specific capacity of the present atomized alloys was apprecialy smaller than that of the nonatomized powder, especially for initial cycles. Full activation of the atomized alloys oftentook several hundreds of cycles. However, no appreciable difference in discharge rate capability was observed with R10 and R12 alloys. Chemical compositions were indistinguishable, although the oxygen contents of the atomized alloys were always higher. Effects of Ni and Cu coating on alloy performance were studied after electroless coating; the coatings noticeably improved the electrode rate capability for all the alloys. The electrode polarization was esecially improved, but not the cycle life. Further studies are needed.
Date: March 1, 1996
Creator: Lim, Hong S.
Partner: UNT Libraries Government Documents Department

Creation and destruction of C{sub 60} and other fullerene solids. Final report

Description: The 1990 announcement of the Huffman-Kratschmer fullerene-production technique set off a world-wide explosion of research into the properties and potential applications of C{sub 60} and C{sub 70}. In the last five years, 4,000+ fullerene articles have appeared in the scientific literature dealing with these fascinating molecules and their condensed phases. They possess a complex chemistry reminiscent of the alkenes, and this has led to the syntheses of numerous new compounds and fullerene-based materials, with suggested applications ranging from medicine to photo-conducting polymers to rocket fuel. The work summarized in this report focused on the creation and destruction of fullerene-based materials, for the purpose of producing new materials of interest. This three year project was supported by a grant from the Advanced Energy Projects Division, Office of Basic Energy Sciences, U.S. Department of Energy (DE-FG03-93ER12133). Following are outlines of the work completed in each of the three years, a section devoted to the professional and educational development of those involved, a brief section on the outlook for fullerene-based materials, and an appendix listing the publications resulting from this project.
Date: June 5, 1996
Creator: Huffman, D. R.
Partner: UNT Libraries Government Documents Department

Negative Electrodes for Li-Ion Batteries

Description: Graphitized carbons have played a key role in the successful commercialization of Li-ion batteries. The physicochemical properties of carbon cover a wide range; therefore identifying the optimum active electrode material can be time consuming. The significant physical properties of negative electrodes for Li-ion batteries are summarized, and the relationship of these properties to their electrochemical performance in nonaqueous electrolytes, are discussed in this paper.
Date: October 1, 2001
Creator: Kinoshita, Kim & Zaghib, Karim
Partner: UNT Libraries Government Documents Department

Insulators and Materials for Closed-Spaced Thermoelectric Modules

Description: The primary goal of this Phase I program has been accomplished: to demonstrate a ceramic, injection-molded eggcrate which will form the support structure for a close-spaced thermoelectric module which can operate at significantly higher temperatures than presently possible with such modules. It has been shown that yttria-stabilized zirconia is compatible at high temperatures with typical thermoelectric materials (TAGS, SnTE and PbTe) and that it can serve as a barrier between them to preclude cross-contamination and doping of the constituents of one leg type by those from the other. Using a 2 x 2 ceramic eggcrate, thermally sprayed molybdenum electrodes have been deposited on a test module which effectively seal each pocket, further reducing the possibility of migration of elements. Based on these results the next tasks are to refine the design of the injection tool and the injection parameters to produce consistent results and to allow increase in the size of the module to that on which commercial, high-temperature thermoelectric modules can be based. In addition, development of the fabrication techniques for segmented thermoelectric legs for use with these ceramic eggcrates at high temperatures must be continued.
Date: July 20, 2003
Creator: Snowden, Donald P.
Partner: UNT Libraries Government Documents Department