Objective: The study evaluates the acute toxicity of the Swietenia Mahagoni leaf in rats of Wistar strain. Methods: Whole leaf powder at a maximum allowable dose (as per OECD guidelines (2000 mg Kg-1

With the increasing intensity of oil and gas field exploration development, wells are also drilling into deeper more complex formations. Conventional steel tools can no longer meet requirements ultra-deep, high-temperature high-pressure wells. The paper first analyzes advantages titanium alloy drill pipe based on basic performance pipe. experimental results show that properties pipes operating ...

A Monte Carlo inverse method has been used on the temperature profiles measured down through the Greenland Ice Core Project (GRIP) borehole, at the summit of the Greenland Ice Sheet, and the Dye 3 borehole 865 kilometers farther south. The result is a 50, 000-year-long temperature history at GRIP and a 7000-year history at Dye 3. The Last Glacial Maximum, the Climatic Optimum, the Medieval Warm...

We present a boundary integral equation formulation for the problem of wave propagation in a borehole of irregular cross-section. The method consists in representing the wave field diffracted at the borehole-rock interface by the radiation from a distribution of surface sources applied along the borehole wall. The wave field in the borehole fluid and in the elastic rock are then expressed using...

[1] During the past decades, the research into fluid-controlled geodynamic processes in the upper crust of the Earth is put foreward regarding the stress accumulation, deformation, and seismicity. In a large-scale injection experiment at the deep borehole site KTB (Kontinentale Tiefbohrung der Bundesrepublik Deutschland) in Germany, more than 84.000 m fresh water was injected in 4000 m depth ov...

A monopole or a dipole source in a fluid borehole generates acoustic waves, part of which propagate along the borehole and the other part enter the formation propagating as Por S-waves. The refracted waves propagating along the borehole wall are used to determine Pand S-wave velocities. However, a significant fraction of the seismic energy radiates into the formation. In this laboratory study, ...

ABSTRACT A new model reduction approach is proposed. The order of a large-scale system is reduced within the neighborhood of its crossover frequency in order to closely preserve the gain and phase of the original system. The minimum and maximum allowable frequency about the crossover frequency of the system is determined using frequency dependent weights. Then the system is perturbed and reduce...