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Anisotropy of conduction electrons in n-InSb and extrinsic and intrinsic properties of HgCdTe

Description: The anistropy of the orbital and spin properties of conduction electrons in InSb has been measured simultaneously using a cyclotron-resonance type experiment. This represents the first time that the anistropy of effective mass in InSb has been directly measured using an optical method.
Date: August 1991
Creator: Yoon, Im T. (Im Taek)
Partner: UNT Libraries

Technique for separation of carrier densities and mobilities in highly nondegenerate multiband semiconductors

Description: The development of the conductivity coefficients is reviewed for both highly degenerate metals, having an energy dependent relaxation time, and semiconductors, obeying Boltzmann statistics and having a relaxation time varying as the energy to the λ power.
Date: December 1975
Creator: Rater, Lonnie M.
Partner: UNT Libraries

The Electrical Conductivity of Commercial Copper

Description: Report issued by the Bureau of Standards over the conductivity of copper. Samples of commercial copper were studied, and the results are presented and discussed. This report includes tables, illustrations, and photographs.
Date: 1911
Creator: Wolff, F. A. & Dellinger, J. H.
Partner: UNT Libraries Government Documents Department

Contact-Resistance Symposium, Bendix Aviation Corporation, Kansas City Division, Sandia Corporation, June 14, 1957, Albuquerque, New Mexico

Description: The objectives of the conference were to accomplish an interchange of information and study the determination of contact resistance. The effect of contacts on AEC production problems is discussed. Otber discussions are presented one applications of contact devices, present testing criteria, materials and process variables, process controls, and future development plans. (T.R.H.
Date: May 1958
Partner: UNT Libraries Government Documents Department

Massively-parallel electrical-conductivity imaging of hydrocarbonsusing the Blue Gene/L supercomputer

Description: Large-scale controlled source electromagnetic (CSEM)three-dimensional (3D) geophysical imaging is now receiving considerableattention for electrical conductivity mapping of potential offshore oiland gas reservoirs. To cope with the typically large computationalrequirements of the 3D CSEM imaging problem, our strategies exploitcomputational parallelism and optimized finite-difference meshing. Wereport on an imaging experiment, utilizing 32,768 tasks/processors on theIBM Watson Research Blue Gene/L (BG/L) supercomputer. Over a 24-hourperiod, we were able to image a large scale marine CSEM field data setthat previously required over four months of computing time ondistributed clusters utilizing 1024 tasks on an Infiniband fabric. Thetotal initial data misfit could be decreased by 67 percent within 72completed inversion iterations, indicating an electrically resistiveregion in the southern survey area below a depth of 1500 m below theseafloor. The major part of the residual misfit stems from transmitterparallel receiver components that have an offset from the transmittersail line (broadside configuration). Modeling confirms that improvedbroadside data fits can be achieved by considering anisotropic electricalconductivities. While delivering a satisfactory gross scale image for thedepths of interest, the experiment provides important evidence for thenecessity of discriminating between horizontal and verticalconductivities for maximally consistent 3D CSEM inversions.
Date: May 16, 2007
Creator: Commer, M.; Newman, G.A.; Carazzone, J.J.; Dickens, T.A.; Green,K.E.; Wahrmund, L.A. et al.
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 conductivity change in polyethylene during irradiation

Description: From abstract: "This temperature data serves to suggest an ionic mechanism for electrical conduction in polyethylene as opposed to an electronic mechanism. In fact, the ion contributing most to the conduction in the polyethylene may well be the proton."
Date: 1952
Creator: Mayburg, Sumner & Lawrence, W. L.
Partner: UNT Libraries Government Documents Department

SPHINX Measurements of Radiation Induced Conductivity of Foam

Description: Experiments on the SPHINX accelerator studying radiation-induced conductivity (RIC) in foam indicate that a field-exclusion boundary layer model better describes foam than a Maxwell-Garnett model that treats the conducting gas bubbles in the foam as modifying the dielectric constant. In both cases, wall attachment effects could be important but were neglected.
Date: December 14, 1998
Creator: Ballard, W.P.; Beutler, D.E.; Burt, M.; Dudley, K.J. & Stringer, T.A.
Partner: UNT Libraries Government Documents Department

First principles calculation of electrical conductivity and giant magnetroresistance of Co{vert_bar}Cu multilayers

Description: We show that the Kubo formula can be used to calculate the nonlocal electrical conductivity of layered systems from first principles. We use the Layer Korringa Kohn Rostoker method to calculate the electronic structure and Green function of Co/Cu/Co trilayers within the local density approximation to density functional theory. This Green function is used to calculate the conductivity through the Kubo formula for both majority and minority spins and for alignment and anti-alignment of the Co moments on either side of the Cu spacer layer. This allows us to determine the giant magnetoresistance from first principles. We investigate three possibilities for the scattering in Co/Cu/Co: (1) equal electron lifetimes for Cu, majority spin Co, and minority spin Co, (2) equal electron lifetimes for majority and minority Co, weaker scattering in Cu and spin dependent interfacial scattering, (3) electron lifetimes for majority and minority spin cobalt proportional to their Fermi energy densities of states and spin dependent interfacial scattering.
Date: December 31, 1995
Creator: Butler, W.H.; Zhang, X.G.; Nicholson, D.M.C. & MacLaren, J.M.
Partner: UNT Libraries Government Documents Department

Joint inversion for mapping subsurface hydrologicalparameters

Description: Using electromagnetic (EM) and seismic travel time data and a least-square criteria, a two-dimensional joint inversion algorithm is under development to assess the feasibility of directly mapping subsurface hydrological properties in a crosswell setup. A simplified Archie's law combined with the time average equation relates the magnetic fields and seismic travel time to two hydrological parameters; rock porosity and pore fluid electrical conductivity. For simplicity, the hydrological parameter distributions are assumed to be two-dimensional. Preliminary results show that joint inversion does have better resolving power for the interpretation than using the EM method alone. Various inversion scenarios have been tested, and it has been found that alternately perturbing just one of the two parameters at each iteration gives the best data fit.
Date: March 7, 2001
Creator: Tseng, Hung-Wen & Lee, Ki Ha
Partner: UNT Libraries Government Documents Department

Multi-rate flowing Wellbore electric conductivity logging method

Description: The flowing wellbore electric conductivity logging method involves the replacement of wellbore water by de-ionized or constant-salinity water, followed by constant pumping with rate Q, during which a series of fluid electric conductivity logs are taken. The logs can be analyzed to identify depth locations of inflow, and evaluate the transmissivity and electric conductivity (salinity) of the fluid at each inflow point. The present paper proposes the use of the method with two or more pumping rates. In particular it is recommended that the method be applied three times with pumping rates Q, Q /2, and 2Q. Then a combined analysis of the multi-rate data allows an efficient means of determining transmissivity and salinity values of all inflow points along a well with a confidence measure, as well as their inherent or far-field pressure heads. The method is illustrated by a practical example.
Date: April 22, 2003
Creator: Tsang, Chin-Fu & Doughty, Christine
Partner: UNT Libraries Government Documents Department

Application of Multi-rate Flowing Fluid Electric ConductivityLogging Method to Well DH-2, Tono Site, Japan

Description: The flowing fluid electric conductivity (FEC) logging method, wellbore fluid is replaced with de-ionized water, following which FEC profiles in the wellbore are measured at a series of times while the well is pumped at a constant rate. Locations were fluid enters the wellbore show peaks in the FEC logs, which may be analyzed to infer inflow strengths and salinities of permeable features intersected by the wellbore. In multi-rate flowing FEC logging, the flowing FEC logging method is repeated using two or more pumping rates, which enables the transmissivities and inherent pressure heads of these features to be estimated as well. We perform multi-rate FEC logging on a deep borehole in fractured granitic rock, using three different pumping rates. Results identify 19 hydraulically conducting fractures and indicate that transmissivity, pressure head, and salinity vary significantly among them. By using three pumping rates rather than the minimum number of two, we obtain an internal consistency check on the analysis that provides a measure of the uncertainty of the results. Good comparisons against static FEC profiles and against independent chemical, geological, and hydrogeological data have further enhanced confidence in the results of the multi-rate flowing FEC logging method.
Date: October 4, 2004
Creator: Doughty, Christine; Takeuchi, Shinji; Amano, Kenji; Shimo, Michito & Tsang, Chin-Fu
Partner: UNT Libraries Government Documents Department

Nonlinear and Nonideal MHD

Description: The primary efforts this year have focused on exploring the nonlinear evolution of localized interchange instabilities, some extensions of neoclassical tearing mode theory, and developing a model for the dynamic electrical conductivity in a bumpy cylinder magnetic field. In addition, we have vigorously participated in the computationally-focused NIMROD and CEMM projects.
Date: November 4, 2002
Creator: Callen, J. D.
Partner: UNT Libraries Government Documents Department

Tank Leak Experiment at the Monk Tank Site, 200 East Area: Electrical Resistance Tomography-Preliminary Results

Description: This report covers the electrical resistance tomography (ERT) work performed at the Mock Tank site, 200 East Area, Hanford Reservation, during the months of July and August, 2001. The work reported herein is to be considered preliminary because it is work in progress. Some of the analyses and interpretation of results are incomplete at this time.
Date: September 20, 2001
Creator: Ramirez, A.; Daily, W.D. & Binley, A.
Partner: UNT Libraries Government Documents Department

Critical Survey on Electrode Aging in Molten Carbonate Fuel Cells

Description: To evaluate potential electrodes for molten carbonate fuel cells, we reviewed the literature pertaining to these cells and interviewed investigators working in fuel cell technology. In this critical survey, the effect of three electrode aging processes - corrosion or oxidation, sintering, and poisoning - on these potential fuel-cell electrodes is presented. It is concluded that anodes of stabilized nickel and cathodes of lithium-doped NiO are the most promising electrode materials for molten carbonate fuel cells, but that further research and development of these electrodes are needed. In particular, the effect of contaminants such as H2S and HCl on the nickel anode must be investigated, and methods to improve the physical strength and to increase the conductivity of NiO cathodes must be explored. Recommendations are given on areas of applied electrode research that should accelerate the commercialization of the molten carbonate fuel cell.
Date: December 1979
Creator: Kinoshita, K.
Partner: UNT Libraries Government Documents Department

Effects of Cyclic Stains on Transport Properties of a Superconducting Composite : Phase I, Degradation of Electrical Conductivity in Copper at 4.2 K

Description: The effects of cyclic strains at 4.2 K on the electrical resistivity of copper have been investigated as Phase I of a program to determine the overall effects on monolithic superconducting composites. This work is a direct application to the design of large superconducting magnets that are subject to several different modes of cyclic strain during assembly and normal operations.
Date: August 1977
Creator: Fisher, E. S.; Kim, S. H.; Linz, R. J. & Turner, A. P. L.
Partner: UNT Libraries Government Documents Department

Superposition in the Interpretation of Two-Layer Earth-Resistivity Curves

Description: From abstract: A method is presented for the interpretation of data on electrical resistivity by the superposition of standard reference curves on those obtained from field observations. This method is applicable where bedrock whose average resistivity is essentially uniform is overlain by overburden whose average resistivity is also uniform but markedly distinct.
Date: 1941
Creator: Roman, Irwin
Partner: UNT Libraries Government Documents Department

SULTAN measurement and qualification: ITER-US-LLNL-NMARTOVETSKY- 092008

Description: Measuring the characteristics of full scale ITER CICC at SULTAN is the critical qualification test. If volt-ampere characteristic (VAC) or volt-temperature characteristic (VTC) are distorted, the criterion of 10 uV/m may not be a valid criterion to judge the conductor performance. Only measurements with a clear absence or low signals from the current distribution should be considered as quantitatively representative, although in some obvious circumstances one can judge if a conductor will meet or fail ITER requirements. SULTAN full scale ITER CICC testing should be done with all measures taken to ensure uniform current redistribution. A full removal of Cr plating in the joint area and complete solder filling of the joints (with provision of the central channel for helium flow) should be mandatory for DC qualification samples for ITER. Also, T and I should be increased slowly that an equilibrium could be established for accurate measurement of Tcs, Ic and N. It is also desirable to go up in down in current and/or temperature (within stable range) to make sure that the equilibrium is reached.
Date: September 21, 2006
Creator: Martovetsky, N N
Partner: UNT Libraries Government Documents Department