Search

Recent years have witnessed a growing concern about the reproductive tract infections (RTI), especially those that are sexually transmitted. The serious threat of AIDS has further drawn attention to the [...]

In this paper, a comprehensive framework is proposed to estimate the anisotropic permeability matrix in trabecular bone specimens based on micro-computed tomography (microCT) imaging combined with pore-scale fluid dynamics simulations. Two essential steps in the proposed methodology are the selection of (i) a representative volume element (RVE) for calculation of trabecular bone permeability and (ii) a converged mesh for accurate calculation of pore fluid flow properties. Accurate estimates of trabecular bone porosities are obtained using a microCT image resolution of approximately 10μm. We show that a trabecular bone RVE in the order of 2×2×2mm3is most suitable. Mesh convergence studies show that accurate fluid flow properties are obtained for a mesh size above 125,000 elements. Volume averaging of the pore-scale fluid flow properties allows calculation of the apparent permeability matrix of trabecular bone specimens.

The present paper describes the development of reliability-based design criteria for oil and/or gas well casing/tubing. The approach is based on the fundamental principles of limit state design. Limit states for tubulars are discussed and specific techniques for the stochastic modeling of loading and resistance variables are described. Zonation methods and calibration techniques are developed which are geared specifically to the characteristic tubular design for both hydrocarbon drilling and production applications. The application of quantitative risk analysis to the development of risk-consistent design criteria is shown to be a major and necessary step forward in achieving more economic tubular design.

David Ray and Amritjit Singh, editors, India: An Anthology of Contemporary Writing. Athens, Ohio: Swallow Press/Ohio University Press, 1983.

THE nicotine content of tobacco varies between wide limits, depending on the species studied. With the view of estimating the nicotine content in tobacco species grown in India, particularly in those of low nicotine content obtained in grafting experiments, a rapid semi-micro method of distillation followed by a spectrophotometric method of estimation have been developed.