TRANSIENTS IN ELECTRICAL PROSPECTING

Geophysics ◽  
1938 ◽  
Vol 3 (3) ◽  
pp. 247-257 ◽  
Author(s):  
Paul F. Hawley
Keyword(s):  
Steady State ◽  
Potential Drop ◽  
Geophysical Prospecting ◽  
Electrical Prospecting

The technique used in the older methods of electrical geophysical prospecting is well known. The measurements of current and potential drop which are made are the steady‐state values, which can be readily measured on indicating‐type meters. The factor of time is of very little importance.

scholarly journals Historical damage pattern and causes of differential damage: an approach based on combining geophysical prospecting, geological and historical-technical data

2008 ◽  
Vol 19 ◽  
pp. 23-32 ◽  
Author(s):  
F. T. Gizzi ◽  
V. Lapenna ◽  
N. Masini ◽  
E. Rizzo
Keyword(s):  
Integrated Approach ◽  
Geophysical Prospecting ◽  
Technical Data ◽  
Damage Pattern ◽  
Geological Surveys ◽  
Macroseismic Effects ◽  
Geophysical Surveys ◽  
Geological Information ◽  
Electrical Prospecting ◽  
Set Up

Abstract. We describe a multidisciplinary and interdisciplinary method to analyse the causes of differential macroseismic effects caused by an earthquake in a historical town. We illustrate the method with a case study based on analysing the damage caused by the 1930 Irpinia earthquake (Me=6.7) in Melfi, a town in southern Italy. A damage pattern map was already available for this site. To understand the anomalies of Melfi damage, we used an integrated approach that combines geological surveys, geophysical prospecting and analysis of unpublished technical-historical data. Geo-electrical prospecting was adopted to infer the geological set-up and to estimate the thickness of shallow deposits. The results of the geophysical surveys were compared with detailed geological information derived from both in situ surveys and boreholes. Finally, cross-correlation among these data and technical reports coeval to the earthquake allowed us to create a complete picture of the possible causes of uneven damage.

scholarly journals SOME PROBLEMS OF ELECTRICAL GEOPHYSICAL PROSPECTING METHODS USED FOR EXPLORATION OF ORE DEPOSITS

2021 ◽  
Vol 12 (3S) ◽  
pp. 731-747
Author(s):  
V. A. Kulikov ◽  
A. G. Yakovlev ◽  
V. A. Polikarpova
Keyword(s):  
Mineral Exploration ◽  
Geophysical Methods ◽  
Mining Industry ◽  
Induced Polarization ◽  
Ore Deposits ◽  
Navigation Systems ◽  
Geophysical Prospecting ◽  
Electrical Prospecting ◽  
Satellite Navigation Systems ◽  
2D And 3D

Electrical geophysical prospecting methods are widely used at different stages of geological exploration. In the last two decades, new computer technologies and satellite navigation systems were successfully introduced in the geophysical industry. As a result, exploration technologies have improved, and new geophysical methods have been developed, such as electrical resistivity tomography (ERT) and spectral induced polarization (SIP) methods. An important role in ore geophysics is played by magnetotelluric (MT) methods. In this article, we focus on the issues of methodology and interpretation of electrical prospecting data for solving ore exploration problems. Special attention is paid to the induced polarization (IP) method that is most widely used in mineral exploration and mining industry as one of the most important and most dynamically developing techniques of ore geophysics. In addition, the issues of correct choices of survey scales and the use of automatic 2D and 3D inversion programs are considered.

DEPTH FACTORS AND RESOLVING POWER OF ELECTRICAL MEASUREMENTS

Geophysics ◽  
1938 ◽  
Vol 3 (2) ◽  
pp. 78-95 ◽  
Author(s):  
H. M. Evjen
Keyword(s):  
Potential Drop ◽  
Point Of View ◽  
Resolving Power ◽  
Ratio Method ◽  
Electrical Measurements ◽  
New Approach ◽  
Resistivity Method ◽  
Electrical Methods ◽  
Electrical Prospecting ◽  
Interpretation Problem

The use of depth factors in electrical prospecting is critically reviewed. The use of depth factors is placed on a rational foundation. This is accomplished by assigning new physical significance to the so‐called apparent resistivities and potential drop ratios measured by electrical methods. It is shown that these measurables may be considered as broadly averaged representations of the distribution of electric images with depth. As a result, universal depth factors exist which may be calculated once for all for any given electrode arrangement. The depth factors are calculated for a number of commonly used electrode arrangements and are found to be smaller than generally assumed. The potential drop ratio method is shown to be superior to the apparent resistivity method in regard to depth of reference as well as to resolving power. The resolution by either method, however, is found to be entirely inadequate to give anywhere near the detail obtained with well logs. The new approach adopted in this paper leads to quite simple and practical methods of analysis and direct solution of the interpretation problem which are illustrated. These methods are shown to have a useful field of application also in gravitational interpretation. The extent to which a detailed analysis justifiably may be carried is briefly examined. From the point of view of practicability it is reaffirmed that the best field of application of the electrical methods is the investigation of horizontal changes such as the mapping of faults and salt dome flanks.

Studies on Water in the Hydration Chamber of a Modified Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 544-545
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Steady State ◽  
Room Temperature ◽  
Small Mass ◽  
Equilibrium Pressure ◽  
Biological Objects ◽  
Mechanical Pump ◽  
Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

Continuous hydrogenolysis of acetal-stabilized lignin in flow

2021 ◽  
Author(s):  
Wu Lan ◽  
Yuan Peng Du ◽  
Songlan Sun ◽  
Jean Behaghel de Bueren ◽  
Florent Héroguel ◽  
...  
Keyword(s):  
Steady State ◽  
Challenges And Opportunities

We performed a steady state high-yielding depolymerization of soluble acetal-stabilized lignin in flow, which offered a window into challenges and opportunities that will be faced when continuously processing this feedstock.

Network reconstruction based on steady-state data

2008 ◽  
Vol 45 ◽  
pp. 161-176 ◽  
Author(s):  
Eduardo D. Sontag
Keyword(s):  
Steady State ◽  
Reverse Engineering ◽  
Theoretical Method ◽  
Network Reconstruction ◽  
Quasi Steady State ◽  
State Data

This paper discusses a theoretical method for the “reverse engineering” of networks based solely on steady-state (and quasi-steady-state) data.

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