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Showing 1 to 16 of 16 for “"DC resistivity"”.
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Optimal experimental design applied to DC resistivity problems
… which is demonstrated by application to DC resistivity problems. The primary goal is to minimize inversion model errors and uncertainties, where the inversion is approached via nonlinear least squares with L1 smoothness constraints. An equally important goal is to find ways to expedite …
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Laboratory Electrical DC Resistivity of Serpentinite, Graphite, Oxide and Sulfide Minerals
… the Earths moon surface. Electrical DC resistivity of chalcopyrite, galena, graphite, hematite, ilmenite, magnetite, pyrite, pyrrhotite and serpentinite was assessed using a Cryogen-Free Measurement System (CFMS) over a temperature range of 10K-300K. The objective of this work is to …
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Imaging ahead of a tunnel boring machine with DC resistivity: a laboratory and numerical study
… tunneling operations. In particular, the DC resistivity method is useful because it is sensitive to a large range of conductivity variations in geological and man made materials. The research presented in my thesis consists of three parts: (1) a laboratory study of a scale model TBM and …
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Boundary element direct current resistivity model to aid in the interpretation of an underground DC resistivity multicomponent survey, A
Includes bibliographical references.
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DC-resistivity profiling as an aid in the study of facies distribution in residual-type iron deposits (Cerro Bolivar, Venezuela)
Includes bibliographical references.
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Modification of DC resistivity arrays for the use of monitoring brine inflow in underground excavations as applied at the Waste Isolation Pilot Plant, SE New Mexico, The
Includes bibliographical references (pages 48-49).
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2D ELECTRICAL RESISTIVITY AND HYDROLOGICAL STUDY OF A SOLUTE PLUME’S MIGRATION PATHWAY THROUGH SANDY LOAM WITHIN NACOGDOCHES COUNTY, TEXAS, USA
… a regressive tract of the Eocene sea. Electrical DC resistivity surveys were conducted across one fifty-six-meter-long traverse using AGI’s multi-electrode SuperSting R8 WIFI RES/IP/SP system, which allowed for rapid and reliable data collection. The resistivity line was surveyed using the …
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Origins of Enhanced Dielectric Properties in Titania-Modified Tantalum Pentoxide Ceramics
… specimens had tan delta values of ∼0.10 and DC resistivity values of <1011O·cm. Hyper-Raman spectroscopy revealed that the ionic polarizability (and thus the intrinsic K) of H-Ta 2O5 ceramics was independent of TiO2 content. Cryogenic electrical measurements suggested that the …
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Chebyshev spectral methods for potential field computation
… equations and apply them to 3-D gravity and DC resistivity modeling. When we approximate a function by a finite sum of Chebyshev polynomials, there are two kinds of errors: truncation and aliasing. We present a cell-average discretization scheme to reduce the aliasing error. Both theoretical …
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Geophysical Investigation of the Yellowstone Hydrothermal System
… (TEM) soundings and 2D direct current (DC) resistivity profiles show that hydrothermal alteration at active sites have a higher electrical conductivity than the surrounding hydrothermally inactive areas. For that reason, airborne TEM is an effective method to characterize large areas and …
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Planar tunneling spectroscopy of thin-film Nb, Nb/normal metal and Nb/semiconductor structures
… dependence study was performed on high-quality, DC-magnetron sputter deposited Nb on single-crystal sapphire. The DC resistivity was measured as a function of ternperature to evaluate the film quality and determine Tc. The critical temperature was found to monotonically decrease with decreasing …
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Dielectric Properties of lce
… and, by studying the results of fourelectrode resistivity surveys of glaciers, it is concluded that the measurements are typical of many natural ice mass,es. The solubility limit for impurities within the ice grain is responsible for the behaviour. Near the melting point however, other effects …
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MOUNTAINHYDRO: INTEGRATING GEOLOGY, GEOPHYSICS AND HYDROGEOLOGY IN A MULTIDISCIPLINARY APPROACH
… pillar involves the use of high resolution DC resistivity surveys and densely spaced transient electromagnetic (EM) methods, both ground-based and airborne. Geophysical surveys play a key role in capturing the subsurface heterogeneity and identifying preferential flow paths within the rock …
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Integrated geophysical investigation for understanding agriculturally induced landslides in southern Peru
… accomplish this, we conducted a combination of DC resistivity, transient electromagnetics (TEM), and seismic surveys. Interpreting geophysical data to image artificial water accumulations in such cases is best performed with either a sequence of time-lapse data with a start time prior to …
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Geometry assessment and strength/stiffness monitoring of lime and cement modified soils via characterization of curing-induced property changes estimated from seismic wave propagation techniques and electrical resistivity
… assessment of production column geometry. DC resistivity testing is used to estimate soilcrete column diameter in a laboratory-scale study and validated via computational modeling. The computational modeling approach is extended to field geometries and a DC electrical resistivity push probe …
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Characterization and Delineation of Karst Geohazards Along RM652 Using Electrical Resistivity Tomography, Culberson County, Texas
… 652, in Culberson County, Texas. 2D electrical resistivity surveys were conducted at sixteen sites to characterize and delineate karst related hazards, both laterally and vertically, associated with the road. Data was collected with a SuperSting (R8/IP) multi-electrode earth resistivity meter …