SHALLOW RESISTIVITY SURVEY AT SOUTH ELTON, LOUISIANA

Geophysics ◽  
1939 ◽  
Vol 4 (4) ◽  
pp. 271-278
Author(s):  
E. E. Blondeau
Keyword(s):  
Direct Current ◽  
Deep Structure ◽  
Current Data ◽  
Oil Field ◽  
Current Electrode ◽  
Contour Map ◽  
Near Surface ◽  
Resistivity Survey ◽  
Direct Association ◽  
A Current

A direct current resistivity survey covering about one and one‐half townships adjacent to the South Elton oil field is described. The contour map based on data taken 100′ from a current electrode shows many near surface anomalies while that based on data taken 1000′ from a current electrode is comparatively uniform. Conclusions reached were: First, that Eltran and direct current data show good qualitative agreement; second, that the large observed variations in near surface resistivity can hardly be attributed to mineralization emanating upward over structure; and third, that the number of anomalies found is so great that their direct association with deep structure is highly improbable.

Structure contour map of the Pondera oil field, Montana

1952 ◽  
Author(s):  
Charles Edgar Erdmann ◽  
B.K. Koskinen
Keyword(s):  
Oil Field ◽  
Contour Map

The Isotope Effect of a Direct Electric Current through Liquid and Solid Metals

1956 ◽  
Vol 11 (1) ◽  
pp. 71-75
Author(s):  
E. Haeffner ◽  
Th. Sjöborg ◽  
S. Lindhe
Keyword(s):  
Liquid Metal ◽  
Electric Current ◽  
Isotope Effect ◽  
Direct Current ◽  
Capillary Tube ◽  
Isotope Separation ◽  
Direct Electric Current ◽  
Separation Effect ◽  
A Current

The isotope separation effect of a direct electric current in a liquid metal is demonstrated by passing a current through mercury, which is enclosed in a capillary tube. The second part of the paper deals with an attempt of establishing an isotope effect when a direct current is passed through an uranium wire.

STACKING OF REFLECTIONS FROM COMPLEX STRUCTURES

Geophysics ◽  
1974 ◽  
Vol 39 (4) ◽  
pp. 427-440 ◽  
Author(s):  
Max K. Miller
Keyword(s):  
Deep Structure ◽  
Control Model ◽  
Layer Model ◽  
Low Velocity ◽  
Seismic Reflection Data ◽  
Near Surface ◽  
Static Correction ◽  
Reflection Data ◽  
Actual Field ◽  
Interval Velocities

Common‐depth‐point seismic reflection data were generated on a computer using simple ray tracing and analyzed with processing techniques currently used on actual field recordings. Constant velocity layers with curved interfaces were used to simulate complex geologic shapes. Two models were chosen to illustrate problems caused by curved geologic interfaces, i.e., interfaces at depths which vary laterally in a nonlinear fashion and produce large spatial variations in the apparent stacking velocity. A three‐layer model with a deep structure and no weathering was used as a control model. For comparison, a low velocity weathering layer also of variable thickness was inserted near the surface of the control model. The low velocity layer was thicker than the ordinary thin weathering layers where state‐of‐the‐art static correction methods work well. Traveltime, moveout, apparent rms velocities, and interval velocities were calculated for both models. The weathering introduces errors into the rms velocities and traveltimes. A method is described to compensate for these errors. A static correction applied to the traveltimes reduced the fluctuation of apparent rms velocities. Values for the thick weathering layer model were “over corrected” so that synclines (anticlines) replaced false anticlines (synclines) for both near‐surface and deep zones. It is concluded that computer modeling is a useful tool for analyzing specific problems of processing CDP seismic data such as errors in velocity estimates produced by large lateral variations in overburden.

Two-dimensional elastic pseudo-spectral modeling of wide-aperture seismic array data with application to the Wichita Uplift-Anadarko Basin region of southwestern Oklahoma

1990 ◽  
Vol 80 (6A) ◽  
pp. 1677-1695 ◽  
Author(s):  
Ik Bum Kang ◽  
George A. McMechan
Keyword(s):  
Large Scale ◽  
Deep Structure ◽  
Sedimentary Basins ◽  
P Wave ◽  
Two Dimensional ◽  
Anadarko Basin ◽  
Near Surface ◽  
University Of Texas ◽  
Wide Aperture ◽  
The University

Abstract Full wave field modeling of wide-aperture data is performed with a pseudospectral implementation of the elastic wave equation. This approach naturally produces three-component stress and two-component particle displacement, velocity, and acceleration seismograms for compressional, shear, and Rayleigh waves. It also has distinct advantages in terms of computational requirements over finite-differencing when data from large-scale structures are to be modeled at high frequencies. The algorithm is applied to iterative two-dimensional modeling of seismograms from a survey performed in 1985 by The University of Texas at El Paso and The University of Texas at Dallas across the Anadarko basin and the Wichita Mountains in southwestern Oklahoma. The results provide an independent look at details of near-surface structure and reflector configurations. Near-surface (<3 km deep) structure and scattering effects account for a large percentage (>70 per cent) of the energy in the observed seismograms. The interpretation of the data is consistent with the results of previous studies of these data, but provides considerably more detail. Overall, the P-wave velocities in the Wichita Uplift are more typical of the middle crust than the upper crust (5.3 to 7.1 km/sec). At the surface, the uplift is either exposed as weathered outcrop (5.0 to 5.3 km/sec) or is overlain with sediments of up to 0.4 km in thickness, ranging in velocity from 2.7 to 3.4 km/sec, generally increasing with depth. The core of the uplift is relatively seismically transparent. A very clear, coherent reflection is observed from the Mountain View fault, which dips at ≈40° to the southwest, to at least 12 km depth. Velocities in the Anadarko Basin are typical of sedimentary basins; there is a general increase from ≈2.7 km/sec at the surface to ≈5.9 km/sec at ≈16 km depth, with discontinuous reflections at depths of ≈8, 10, 12, and 16 km.

scholarly journals Seismic investigations of the Martian near-surface at the InSight landing site

2020 ◽  
Author(s):  
Cedric Schmelzbach ◽  
Nienke Brinkman ◽  
David Sollberger ◽  
Sharon Kedar ◽  
Matthias Grott ◽  
...  
Keyword(s):  
Deep Structure ◽  
Landing Site ◽  
P Wave ◽  
Mission Design ◽  
Normal Operation ◽  
Seismic Signals ◽  
Martian Surface ◽  
Broadband Seismometer ◽  
Near Surface ◽  
Martian Regolith

<p>The InSight ultra-sensitive broadband seismometer package (SEIS) was installed on the Martian surface with the goal to study the seismicity on Mars and the deep interior of the Planet. A second surface-based instrument, the heat flow and physical properties package HP<sup>3</sup>, was placed on the Martian ground about 1.1 m away from SEIS. HP<sup>3</sup> includes a self-hammering probe called the ‘mole’ to measure the heat coming from Mars' interior at shallow depth to reveal the planet's thermal history. While SEIS was designed to study the deep structure of Mars, seismic signals such as the hammering ‘noise’ as well as ambient and other instrument-generated vibrations allow us to investigate the shallow subsurface. The resultant near-surface elastic property models provide additional information to interpret the SEIS data and allow extracting unique geotechnical information on the Martian regolith.</p><p>The seismic signals recorded during HP<sup>3</sup> mole operations provide information about the mole attitude and health as well as shed light on the near-surface, despite the fact that the HP<sup>3 </sup>mole continues to have difficulty penetrating below 40 cm (one mole length). The seismic investigation of the HP<sup>3</sup> hammering signals, however, was not originally planned during mission design and hence faced several technical challenges. For example, the anti-aliasing filters of the seismic-data acquisition chain were adapted when recording the mole hammering to allow recovering information above the nominal Nyquist frequency. In addition, the independently operating SEIS, HP<sup>3</sup> and lander clocks had to be correlated more frequently than in normal operation to enable high-precision timing.</p><p>To date, the analysis of the hammering signals allowed us to constrain the bulk P-wave velocity of the volume between the mole tip and SEIS (top 30 cm) to around 120 m/s. This low velocity value is compatible with laboratory tests performed on Martian regolith analogs with a density of around 1500 kg/m<sup>3</sup>. Furthermore, the SEIS leveling system resonances, seismic recordings of atmospheric pressure signals, HP<sup>3</sup> housekeeping data, and imagery provide additional constraints to establish a first seismic model of the shallow (topmost meters) subsurface at the landing site.</p>

scholarly journals Deep structure of the Anapa flexural-rupture zone, Western Caucasus

2019 ◽  
pp. 3-11
Author(s):  
E. A. Rogozhin ◽  
A. V. Gorbatikov ◽  
Yu. V. Kharazova ◽  
M. Yu. Stepanova ◽  
J. Chen ◽  
...  
Keyword(s):  
Deep Structure ◽  
Sedimentary Cover ◽  
Western Caucasus ◽  
Tectonic Structures ◽  
Deep Roots ◽  
Near Surface ◽  
North West ◽  
The North ◽  
Deep Faults ◽  
Tectonic Zones

In the period from 2007 to 2017 complex geological and geophysical studies were carried out in the three largest flexural-rupture fault zones in the North-West Caucasus (Anapa, Akhtyrka and Moldavan). The micro-seismic sounding (MSM) was used as the main geophysical method. Studies with the help of MSM allowed us to identify the features of the deep structure of the earth’s crust in the study area and to associate them with specific tectonic structures on the surface.The binding was carried out by harmonizing the results of the MSM and the parameters of the section of the sedimentary cover and crustal boundaries according to the drilling data and the work previously performed by the reflected wave method (MOVZ). It was found that the Anapa flexure and longitudinal tectonic zones have clear deep roots, and also separate the pericline of the North-Western Caucasus from the Taman Peninsula and from the lowered blocks of the Northern slope of the folded system.Faults in the study area are divided into: (1) deep faults of the Caucasian stretch, penetrating into the lower crust and even to the upper mantle, and (2) near-surface faults, do not extend to the depths beyond the thickness of the sedimentary cover. The seismogenic role of these tectonic disturbances in the studied seismically active region has been determined.

scholarly journals Fluoride removal using electrocoagulation technique

2021 ◽  
Vol 877 (1) ◽  
pp. 012047
Author(s):  
Hind M. Ewadh ◽  
Mustafa J. Al Imari ◽  
Sabrean F. Jawad ◽  
Hayfaa A. Mubarak
Keyword(s):  
Severe Disease ◽  
Electrical Current ◽  
Electrode Spacing ◽  
Polluted Water ◽  
Fluoride Removal ◽  
Acidic Environment ◽  
Current Electrode ◽  
The Past ◽  
The Impact ◽  
A Current

Abstract A modest quantity of fluoride can increase the mineralization of teeth and reduce their cavities. But the presomerence of fluoride in excess in water can lead to severe disease infertility. In the past few decades, scientists have thus been preoccupied with developing ways to reduce sewage fluoride concentrations and reduce their effects on human health. The present study is aimed at using the technology of electrocoagulation to remove fluoride from polluted water. Tests have been done to examine the elimination of fluoride with a rectangular electrocoagulation cell and examine the impact of the experimental aspects on fluoride extraction, specifically electrical current, electrode spacing, and pH. The authors found that 93% of the fluoride has been extracted using 5mm spaced electrodes with a current density of 2 mA/cm2 and a level of pH of 7 from the polluted water after 20 min of processing. Experimental factors considerably impact the efficacy of fluoride removal. In the acidic environment, greater effectiveness of fluoride removal is being attained. The elimination effectiveness depends directly on the electric current, whereas the distance between poles is adversely linked to fluoride elimination.

scholarly journals Investigation of changes in the characteristics of LED matrices of the on-board luminaire during tests in the electrocycling mode.

2021 ◽  
Author(s):  
I.V. Frolov ◽  
◽  
V.A. Sergeev ◽  
A.M. Hodakov ◽  
S.A. Zaytsev ◽  
...  
Keyword(s):  
Leakage Current ◽  
Direct Current ◽  
Coefficient Of Variation ◽  
Convection Heat Transfer ◽  
Voltage Range ◽  
The Matrix ◽  
Operating Current ◽  
In Series ◽  
The Difference ◽  
A Current

The paper presents the results of studies of changes in the characteristics of LED COB matrices of the GW P9LR31.EM - DURIS S 8 type as part of a LED luminaire when tested under the direct current in a continuous mode and in an electrocycling mode. The arrays consist of eight InGaN/GaN LED dies connected in series, coated with a phosphor. Calculation in the Comsol Multiphtsics environment of the temperature field of the luminaire at the rated operating current and free convection heat transfer showed that the maximum overheating of the matrices does not exceed 46 K, and the difference in their temperatures is 2 K. At the same time, the experimental values of the thermal resistances of the matrices of a real lamp vary from 42 to 58 K/W. Before testing, the I-V characteristics of the matrices differ markedly in the level of leakage current in the voltage range from 14 V to 19 V, and the LEDs in the luminaire matrices have a significant spread in the brightness of emission in the microcurrent mode. The degree of this scatter within each matrix was estimated by measuring the luminescence brightness of each die of the matrix and calculating the coefficient of variation γ. It was found that the coefficient of variation of the emission brightness of the COB matrix dies measured at a current of 100 nA strongly correlates with the leakage current. When testing a luminaire under the direct current, the most significant changes in the electrophysical and optical characteristics of COB matrices are observed in the range of microcurrents: the distribution of the emission brightness of the matrix dies at a current of 100 nA becomes more uniform. The greatest changes in matrix characteristics were observed after the first 700 hours of testing, that is, at the running-in stage. At the same time, no correlation was found between the degree of change in the characteristics of the matrices during tests and their thermal resistances.

Study on Arc and Drop Transfer Behaviors of DCEN MAG Welding

2014 ◽  
Vol 887-888 ◽  
pp. 1290-1293
Author(s):  
Xu Ming Wang ◽  
Qing Xia Bi
Keyword(s):  
Direct Current ◽  
High Speed ◽  
Welding Process ◽  
Mag Welding ◽  
High Speed Camera ◽  
High Current ◽  
Current Electrode ◽  
The Stability

By means of the high speed camera, the arc and drop transfer behaviours of direct current electrode negative MAG welding process are researched. The influences of luminous arc ball on the stability of MAG welding process are analyzed. On this basis, the process interval of DCEN MAG welding is determined. And the influences of wire polarity on wire melting coefficient are compared. By using the shield gas 98%Ar + 2%O2, the stable drop transfer manner can be divided into two kinds: dropwise transfer with low current, and streaming transfer with high current.

The application of the mise-a-la-masse electrical technique in Greenstone belt gold exploration

1989 ◽  
Vol 20 (2) ◽  
pp. 113
Author(s):  
L.G.B.T. Polomé
Keyword(s):  
Greenstone Belt ◽  
Electrical Potential ◽  
Gold Deposits ◽  
Iron Formation ◽  
Banded Iron Formation ◽  
Current Electrode ◽  
Barberton Greenstone Belt ◽  
A Current ◽  
Ore Zones ◽  
Gold Bearing

Most of the gold deposits in the Barberton Greenstone belt of South Africa are relatively small and in structurally complex geological areas.The mise-a-la-masse electrical technique, where a current electrode is earthed in a mineralised zone, was used on one of our exploration projects consisting of a sulphides/gold-bearing carbonaceous banded iron formation within a succession of mafic, ultramafic and sedimentary rocks. The technique was successful in delineating individual mineralised units within a broad lithological sequence. During the survey, electrical potential measurements were recorded on surface, in underground drives and in twenty five boreholes. Measurements were also repeated by earthing the mineralised zone in a number of boreholes. Major discontinuities were recognised within the ore zones and used to interpret geological structures. These were then used to define specific units for ore reserve calculations and the application of selected mining techniques.

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