Estimating aquifer hydraulic parameters from electrical resistivity measurements; a case study at Khuff Formation Aquifer, Al Quwy’yia Area, Central of Saudi Arabia

2015 ◽  
Author(s):  
Mohamed Metwaly* ◽  
Mohamed El Alfy ◽  
Eslam Eawad ◽  
Ahmed Ismail ◽  
Gad El-Qady
Keyword(s):  
Electrical Resistivity ◽  
Saudi Arabia ◽  
Hydraulic Parameters ◽  
Resistivity Measurements

scholarly journals Karst Detection, Prevention and Correction: A Case Study along the Riyadh Metro Line 3 (Saudi Arabia)

Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1429 ◽  
Author(s):  
Manuel Cueto ◽  
Pablo de la Puente ◽  
Carlos López-Fernández ◽  
Luis Pando ◽  
Daniel Arias
Keyword(s):  
Electrical Resistivity ◽  
Saudi Arabia ◽  
Preventive Measures ◽  
Seismic Refraction ◽  
Comprehensive Investigation ◽  
Urban Transit ◽  
Transit System ◽  
Cavity Filling ◽  
Metro Project

In the framework of the largest urban-transit system ever built from scratch, the Riyadh Metro Project (6 lines totaling 176 km), a comprehensive investigation was carried out for karst detection, prevention and correction. This case study of the Metro Line 3 (41.6 km) seeks to show how the multi-technique geophysical survey (seismic refraction, electrical resistivity and ground penetration radar down to 40–50 m depth) was found to be a successful tool in detecting karst features. Preventive measures included systematic probing drilling to anticipate karst cavities below foundations (653 piers) and tunnel lining evaluation using 2D finite elements. Finally, this paper provides initial guidance of the corrective techniques used for each engineering challenge, such as cavity filling with grouting, geogrid reinforcement, etc.

In-situ electrical-resistivity measurements in the high-voltage electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 68-69
Author(s):  
W. E. King
Keyword(s):  
Electrical Resistivity ◽  
Electron Microscope ◽  
High Voltage ◽  
Resistivity Measurements ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron ◽  
Wide Range ◽  
Helium Gas

A side-entry type, helium-temperature specimen stage that has the capability of in-situ electrical-resistivity measurements has been designed and developed for use in the AEI-EM7 1200-kV electron microscope at Argonne National Laboratory. The electrical-resistivity measurements complement the high-voltage electron microscope (HVEM) to yield a unique opportunity to investigate defect production in metals by electron irradiation over a wide range of defect concentrations.A flow cryostat that uses helium gas as a coolant is employed to attain and maintain any specified temperature between 10 and 300 K. The helium gas coolant eliminates the vibrations that arise from boiling liquid helium and the temperature instabilities due to alternating heat-transfer mechanisms in the two-phase temperature regime (4.215 K). Figure 1 shows a schematic view of the liquid/gaseous helium transfer system. A liquid-gas mixture can be used for fast cooldown. The cold tip of the transfer tube is inserted coincident with the tilt axis of the specimen stage, and the end of the coolant flow tube is positioned without contact within the heat exchanger of the copper specimen block (Fig. 2).

Sign in / Sign up

Export Citation Format

Share Document