SSZ-13 zeolite was modified by two kinds of post-treatment methods such as steaming and SiO₂ surface passivation (silylation) for ETP catalyst with high activity. The former steaming treatment was conducted in the range of 400-700 °C, whereas the latter surfaces passivation was applied to a chemical liquid deposition (CLD) technique that uses various silylation agents such as tetramethylorthosilicate (TMOS), tetraethylorthosilicate (TEOS), and tetrabuthylorthosilicate (TBOS). Catalysts were characterized by powder-XRD, ICP, Ar-phsisorption, solid-state Al MAS NMR, and NH₃-TPD, and their activities were tested in fixed bed reaction system.
View Article and Find Full Text PDFThe effects of catalyst supports on catalyst performance in the hydrotreatment of vegetable oils (to produce fuel-range hydrocarbons such as gasoline, jet fuel, and diesel) were investigated, using three types of zeolites (ZSM-5, HY, and zeolite-beta (BEA)) that differ in their silica/alumina ratios. Structural characterization of the catalysts was performed using ICP, XRD, BET, TEM, and NH₃-TPD. Catalytic tests were carried out in a fixed-bed reaction system at 400 °C and 50 bar.
View Article and Find Full Text PDFMesoporous SiO₂–Al₂O₃ (SA) catalysts with different SiO₂ contents were prepared, for the selective production of p-xylene from dimethylfuran/ethylene through the combination of cycloaddition and dehydrative aromatization reactions, by a co-precipitation method. For comparison, commercial SiO₂–Al₂O₃ and ZSM-5 zeolites (Si/Al₂ = 30, Si/Al₂ = 80) were also employed as catalysts in the same reaction. The pore size of the catalysts played an important role in determining the catalytic performance in the production of p-xylene.
View Article and Find Full Text PDFp-Xylene (PX) is an important large-volume commodity chemical in the petrochemical industry. Therefore, research on producing PX from bio-mass-derived resources is a considerable interest in relation to future alternative technologies. Recently, a new potential route for the direct and selective production of bio-based PX was reported, referred to as the Diels-Alder cycloaddition of biomassderived 2,5-dimethylfuran (DMF) and ethylene followed by the dehydration of an intermediate.
View Article and Find Full Text PDF[Purpose] To evaluate differences in pectoral muscle tightness according to arm abduction angle and to determine the best arm abduction angle for stretching of pectoral muscle tightness in breast cancer patients. [Subjects and Methods] Horizontal abduction differences of shoulders were measured bilaterally by arm abduction to 45°, 90°, and 135° to determine the best arm abduction angle for measuring pectoral muscle tightness. Thirty-two patients were divided into three pectoral muscle stretching groups (A: 45°, B: 90°, and C: 135°).
View Article and Find Full Text PDFTo enhance the ability of indirubin derivatives to inhibit CDK2/cyclin E, a target of anticancer agents, we designed and synthesized a new series of indirubin-3'-oxime derivatives with combined substitutions at the 5 and 5' positions. A molecular docking study predicted the binding of derivatives with OH or halogen substitutions at the 5' position to the ATP binding site of CDK2, revealing the critical interactions that may explain the improved CDK2 inhibitory activity of these derivatives. Among the synthesized derivatives, the 5-nitro-5'-hydroxy analogue 3a and the 5-nitro-5'-fluoro analogue 5a displayed potent inhibitory activity against CDK2, with IC(50) values of 1.
View Article and Find Full Text PDFJ Nanosci Nanotechnol
May 2009
Mesoporous silica-pillared H(+)-kenyaite (SPK) derivatives with highly ordered gallery structure and thermal resistance were prepared by the hydrolysis of TEOS (tetraethylorthosilicate) in interlayer space, using DDA (dodecylamine) as catalyst and template. DDA-TEOS/H(+)-kenyaite intercalation compounds were obtained by the dispersion of H(+)-kenyaite in DDA-TEOS solution. DDA-TEOS/H(+)-kenyaites were hydrolyzed rapidly in pure water, forming siloxane pillared H(+)-kenyaites.
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