Papers by Keyword: Quaternary

Abstract: Equilibrium adsorption of quaternary component mixture (phenol, butanol, butan-2-ol and 2-methyl butan-2-ol) onto activated carbon derived from oil-palm empty fruit bunch was studied. Henry isotherm 2-parameter model was used as an improvement to Langmuir and Freundlich 2-parameter isotherm model. The 3-parameter isotherm models applied to the quaternary adsorption system included Redlich Peterson, Sips and Toth. Trial and error method of excel solver was used to evaluate the parameters in the models. Data fitness was based on correlation coefficient (R2) and average percentage error (APE). For the two-parametric isotherm models, Langmuir predicted the adsorption equilibrium well with APE and R2 values of 0.20883 and 0.9868; 0.007669509 and 0.9338; and 3.64355718 and 0.9410 for butanol, butan-2-ol and 2-methyl butan-2-ol respectively. The maximum mono-layer capacity (qm) obtained from Langmuir model for butanol, butan-2-ol and 2-methyl butan-2-ol adsorption were 3558.962mg/g, 2.064233mg/g and 22.6423mg/g respectively. Sip and Toth fitted excellently well among the three- parametric isotherm models. The Sip isotherm model gives APE and R2 values of 0.010536 and 0.9346; and 5.14458 and 0.9250 for phenol and 2-methyl butan-2-ol respectively. The Toth isotherm model gives APE and R2 values of 4.83521 and 0.9866; and 0.02595 and 0.9411 for butanol and butan-2-ol respectively. The isotherm models prove applicable for the quaternary adsorption system.

Abstract: The quaternary InAlGaN-barrier GaN MOS-HEMT (high-electron-mobility transistor) with enhancement mode operation was displayed as V_th=0.65V and the maximum drain current ~ 40 mA/mm at V_DS=10V with L_G=15μm and L_GD=20μm. The measured rocking-curve and RSM (reciprocal space mapping) for epitaxial quality was confirmed the composition of the quaternary and analyzed the relaxation between InAlGaN-barrier and GaN Buffer layer. The surface roughness of InAlGaN was observed by AFM (Atomic force microscopy). The positive polarity of V_th was obtained with the gate lengths 3-30μm, and short channel effect was discussed.

Abstract: In this research, effect of pH toward adsorption of gold (III) on silica modified with methyl quaternary ammonium (SMQA) has been investigated.Additionally, its application an effect of Cr₂O₄^2-on adsorbed [AuCl₄]^-and effect of pH were carried out and to determine by atomic adsorption spectrometry (AAS). The experimental condition was optimized in batch process to achieve the maximum efficiency. The result showed that optimum pH 5 for adsorption. The gold desorbed increasing before 30 minutes, there were before and after adsorbed gold due at the long distribution axis from transmission electron microscopy (TEM) image. The maximum capacity of SMQA obtained 169.98 mg/g.The R₂ values indicate that the Langmuir isotherm fit the the experimental data better than the Freundlich at room temperature. The adsorption gold (III) ion with material SMQA was chemisorption and an effect of Cr₂O₄^2-to minimize sorption.

Abstract: Based on field test,Typical debris flow profile in Quaternary was analyzed on the eastern edge of Qinghai-Tibet Plateau. According to relationship between debris flow deposition profile and geological age,debris flow deposition and neotectonics history,deep-sea oxygen isotope curve,loess-paleosol series were compared. Like other sediments, debris flow sedimentary body is constructed with action of neotectonics and climate.Debris flow deposits within the body surported by the absolute age date was a regular change in the vertical,which also reflected the environmental evolution. The relationship between environmental evolution and debris flow deposits was analyzed and the following conclusions were drawn: Fluctuations of debris flow deposits and intermittent uplift of neotectonics was basically a coincidence since the Quaternary in Xiaojiang River Basin whose debris flow deposits may correspond to climate of cold (cool) wet or warm (hot) wet.Fluctuations of debris flow deposits and climate cycles was basically a coincidence in Bailongjiang River Basin whose debris flow deposits only corresponds to the warm (hot) wet climate.

Abstract: Shanxi downed-faulted basin mainly consists of Datong basin, Taiyuan basin, Linfen basin and Yuncheng basin, having thick quaternary stratum. Affected by geological structure, topography, stratum conditions and other factors, ground fissure disasters are well developed. Using the development and evolution of tectonic-type ground fissures in the faulted basin as research objects, from the two aspects of horst-graben structure and basal activity of fault belt, this study explored the causes of quaternary ground fissures in Shanxi down-faulted basin. Studying the distribution characteristics, formation mechanism and the disaster-causing effects has the theoretical significance of a better summary and understanding on ground fissures and other geological disasters, as well as providing theoretical basis for prediction and prevention means of the disasters.

Abstract: Cu2ZnSnSe4 (CZTSe) thin films were grown on Corning glass 1737 by sequential methods of sputtering deposition and selenization process. As-grown films showed that elemental Cu, Zn, and Sn were in the nearly CZTSe stoichiometric ratio with Se-deficiency as detected by Energy Dispersive X-Ray spectrometry (EDX). In order to attain film stoichiometry, as-deposited films were subjected to selenization process in tube furnace under Ar ambient at different selenization temperatures for 10-60 min. It was found that compositions of binary compound in the sputtering target as well as selenization are critical for the growth of the CZTSe films. The structural characteristics of the selenized CZTSe films revealed a highly oriented stannite CZTSe phase with (112), (220/204) and (312/116) growth orientations and a CuSe secondary phase. By using 0.5% KCN solution, CuSe secondary phase could be totally etched from the CZTSe film surface.