This paper describes a simple method to evaluate an acoustic altered zone around the borehole using an array of sonic waveforms. The method is based on a semblance velocity analysis and a nonlinear travel time window is introduced. On the assumption that a velocity gradient of the altered zone may be linear, the nonlinear travel time window is calculated as a function of averaged velocity and a...

In this paper, we present resistivity-logging-measurement simulation with the use of two types of borehole logging devices: those which operate with zero frequency (direct current, DC) and those with higher frequencies (alternate current, AC). We perform simulations of 3D resistivity measurements in deviated wells, with a sharp angle between the borehole and formation layers. We introduce a hie...

A new computer program, FLASH (Flow-Log Analysis of Single Holes), is presented for the analysis of borehole vertical flow logs. The code is based on an analytical solution for steady-state multilayer radial flow to a borehole. The code includes options for (1) discrete fractures and (2) multilayer aquifers. Given vertical flow profiles collected under both ambient and stressed (pumping or inje...

This report describes the activities and preliminary findings of the second year of our project on Storglaciären during the summer of 2002. Ice penetrating radar studies were used together with borehole video and other down-hole experiments to investigate englacial water flow. The radar surveys together with the borehole experiments suggest a new model for englacial drainage, wherein crevasse-l...

INTRODUCTION To flip a switch "down," our motor system can normally rely on concordant visual, gravitational, and egocentric cues about the vertical. However, divers must sometimes perform this task while visual cues are limited and gravitational cues are misaligned with egocentric cues. Astronauts must also flip switches "down" in absence of gravitational cues. Our study evaluates this ability...

We present analytical solutions for the temperature around the borehole heat exchanger which account for: (I) finite length line-source; (II) natural vertical gradient of the ground temperature; (III) arbitrary changes of the ground surface temperature. We find that the time-dependent part of the solution decays as a power of the time approaching the steady state limit. The long-time limit and ...

Microfluidics is used in a wide array of applications including photonics, catalysis, optoelectronics, particle synthesis, bio-diagnosis and tissue engineering. Poly(dimethyl) siloxane (PDMS) is one of the most widely used materials for the fabrication of such devices. In many applications, applied flow gives rise to pressure variations along the length of the channel and a commensurate spatial...

Simulated Thermal Response Test data are analyzed in order to evaluate the effect of the tridimensionality model’s feature in determining the proper value of the soil thermal conductivity and borehole thermal resistance, necessary for the geothermal energy storage systems’ design in real conditions. The 3D system’s simulation during the Thermal Response Test is realized by adopting the finite e...