Research on algorithm of borehole resistivity imaging method

Tradicionalna metoda istraživanja istosmjerne struje suočit će se s velikim izazovom kad se otkrije duboki, složeni geološki cilj. U tu svrhuje razvijena je metoda unaprijednog modeliranja i inverznog modeliranja otpora bušotine. U skladu s geološkim značajkama, postavljen je geološki model. Numerička simulacija pokazuje da je metoda otpora bušotine vrlo dubok, složen geo-model. Stoga ovo istraživanje daje novu ideju za istraživanje dubokog, složenog cilja geo-električnog modela.Traditional dc electrical exploration method will face great challenge when detecting deep, complex geologic target. With the purpose, forward modelling and inverse modelling method of borehole resistivity has been developed. According to the characters of geology, the geological model has been set up. The numerical simulation shows that borehole resistivity method is a very deep, complex geo-model. Therefore, this research provides a new idea for exploring deep, complex target of geo-electrical model

MITIGATING THE GLASS-WEAVE EFFECT INSIDE A BGA

For a printed circuit board (PCB) that includes many high-speed differential pairs may be routed the signal integrity (SI) performance of the pairs is to be carefully considered. One factor that may lead to a poorer SI performance, on the PCB itself and within a ball grid array (BGA) that is mounted on the PCB, is the glass-weave effect. To mitigate the impact of the glass-weave effect inside of a BGA, techniques are presented herein that support rotating the BGA by a free angle. With such a BGA rotation, a pair\u27s traces will be rotated by the same angle and, consequently, the glass-weave effect on those traces can be mitigated

An analytical model for gas diffusion though nanoscale and microscale fibrous media

Gas diffusion in nanofibrous and microfibrous materials is of great interest in microfluidics. In this work, an analytical model is proposed, based on fractal theory, to quantify gas diffusion across fibrous media composed of nanofibers and microfibers. The fractal model is expressed in terms of pore area and tortuosity fractal dimensions, allowing statistical quantification of the geometrical structures of fibrous media. Knudsen diffusion in nanoscale pores is considered. To validate this model, moisture vapor diffusion rate through electrospun nanofibrous webs was measured using the inverted-cup method. The diffusivities predicted from the proposed model agree well with the experimental measurements in the present investigation and those reported in the literature for effective diffusivities of gas diffusion layers in fuel cells. Based on the model, the effect of porosity, fiber radius, and the ratio between the minimum and the maximum pore sizes on the effective diffusivity is analyzed