Papers by Keyword: Dissolved Gas

Abstract: Tetramethylammonium hydroxide (TMAH) is a metal-free strong alkaline solution which can etch poly-Si. The concentration of dissolved gas as well as the concentration of TMAH affects etching rate of poly-Si. The detailed kinetics of poly-Si etching in TMAH solution is investigated in this study. The effect of water and TMAH concentration on the etching kinetics of poly-Si was investigated by using various concentrations of TMAH solution. It is found that H₂O in TMAH solution plays an important role in etching poly-Si. Presence of dissolved CO₂ and O₂ in TMAH solution tends to inhibit etching of poly-Si. The concentration of dissolved CO₂ and O₂ in TMAH were reduced by Ar bubbling, thereby the poly-Si etching rate increased.

Abstract: Shale gas is one of unconventional natural gas reservoirs,with forming pattern of self-generating and self-preserving. The research indicates that the distribution characteristics of shale gas content is influenced by the factors of the depth,the structure shape,the total carbon organic and the physical property of shale reservoir. The shale gas is on dynamic balance among the adsorbed gas, the free gas and the dissolved gas. By the exploration and development of shale gas,we obtained important theoretical understanding that there exists a parabola model relation between the shale gas content and the depth of shale reservoir,which is called L-W model of enriched accumulation belts of shale depth. Theory and practice studies show that the synclinal layer is the main structural factors controlling the enrichment of shale gas. Therefore,in the background of stronger geological tectonic movements in our country, finding weak tectonic area such as the synclinal layer formation occurrence,is the exploration direction for determination of favorable target areas of shale gas.

Abstract: To forecast power transformer fault, this paper proposed a integrated algorithm. Research found that discrete time series of power transformer dissolved gases concentration have 2 main types: the s type and the monotone increasing type. The gray verhulst model was chosen for forecasting the s type series, while the gray model predicted the monotone increasing type data. The two models combined a new integrated forecast model. The fault diagnosis method combines the improved three-ratio method and gray artificial immune algorithm, so it can diagnoses both single and multi power transformer faults, and give the fault location. Experiments show that the power transformer fault forecast algorithm is effective and reliable.