Laboratory experiments were performed on cubic samples of Austin Chalk to investigate the effect of fabric-induced anisotropy on the interpretation of fracture specific stiffness. The experimental results found that the fabric-induced layering complicates the interpretation of fracture specific stiffness. Seismic measurements from a sample with small layers (i.e., spacing and thickness) show th...

The drift of temperature measurements by semiconductor negative temperature coefficient thermistors is a well-known problem. This study analyzes the drift characteristics of the thermistors designed and used at the Royal Netherlands Institute for Sea Research for measuring high-frequencyO(1Hz) temperature fluctuations in the ocean. These thermistors can be calibrated to high precision and accur...

In this talk we present several representation theorems and averaging theorems for members of the difference class of secant updates introduced by Broadlie, Gourlay , and Greenstadt in 1973. The BFGS update is a well-known member of this difference class. We begin with the notion of an update kernel and use it to construct a new parametrization of the difference class of secant updates. Next we...

Considered is the interaction of macro-and micro-cracks in an anisotropic piezoelectric solid. The GreenÕs function and principle of superposition are used to formulate a system of singular integral equations for solving the unknown temperature discontinuity and elastic displacement-electric potential. The residual heat ̄ux, stress and electric displacement on the microcrack are evaluated direc...

Hydraulic fracturing (HF), as a stimulation technique in petroleum engineering, has made possible the oil production from reservoirs with very low permeability. The combination of horizontal drilling and multiple HF with various perforation angles has been widely used to stimulate oil reservoirs for economical productions. Despite the wide use of HF, there are still ambiguous aspects that requi...

We derive in algebraic form the displacement and stress fields produced by a triangular element of constant slip by superposing the solution of Comninou and Dundurs (1975) for an angular dislocation in an elastic half-space. Triangular elements are more flexible for simulating complex geometries than the rectangular elements widely used for modeling slip zones as a superposition of constant sli...

hydraulic fracturing (hf), as a stimulation technique in petroleum engineering, has made possible the oil production from reservoirs with very low permeability. the combination of horizontal drilling and multiple hf with various perforation angles has been widely used to stimulate oil reservoirs for economical productions. despite the wide use of hf, there are still ambiguous aspects that requi...