Facile Synthesis and Synergetic Interaction of VPO/ß-SiC Composites toward Solvent-Free Oxidation of Methanol to Formaldehyde.

Composite materials have revealed remarkable activities in various catalytic applications. However, choosing an appropriate material to enhance the catalytic activity and stability is a major challenge in the field of catalysis. In this article, we reported vanadium phosphorus oxide (VPO)/ß-SiC as a stable composite material with good catalytic activity. VPO/ß-SiC composite materials with different compositions were fabricated by the impregnation technique to investigate the catalytic activity and stability of these materials in liquid-phase reactions. The physiochemical characteristics of the prepared catalysts were analyzed by several spectroscopic methods. The catalytic activities of VPO/ß-SiC composites were studied in a solvent-free oxidation of methanol using tert-butyl hydroperoxide (TBHP) as an oxidant. The reaction conditions were optimized by changing various reaction parameters. Under optimized reaction conditions, the 10 wt % VPO/ß-SiC composite showed 100% conversion with 89.8% selectivity to formaldehyde.

Liquid phase esterification of acetic acid over WO3 promoted ß-SiC in a solvent free system.

A series of tungstate promoted ß-SiC catalysts was synthesized by a wetness impregnation method. The as synthesized catalysts were unambiguously characterized by XRD, Raman, FTIR, XPS, UV-Vis DRS, TEM, BET surface areas and FE-SEM, and simultaneously the total amount of the acidity of the catalysts was estimated by NH(3)-TPD. The catalytic activities of the synthesized materials were tested in the liquid phase esterification of acetic acid with n-butanol in a solvent free medium. The reaction parameters were optimized to a temperature of 120 °C, molar ratio of butanol and acetic acid of 1:2 and a reaction time of 6 h after performing a number of experiments. Under the optimum conditions, the catalytic esterification revealed a significant effect of 88% conversion with 100% selectivity to butyl acetate in 20 wt% WO(3)/ß-SiC. This is the first report on the effective utilization of ß-SiC as a catalyst support for liquid phase esterification of acetic acid.

Magnetic properties of nanocrystalline beta-SiC.

Four-hour ball-milled beta-SIC product synthesized by the thermal plasma technique shows room temperature ferromagnetism. The semi-lambda signature of the field-cooled magnetization (FCM) and zero field-cooled magnetization (ZFCM) curves suggest the possible signature of a glassy ferromagnetism state in the sample. The prominent fall in the magnetization value at around 50 K observed in ZFCM curve reveals the existence of a sharp transition from a ferromagnetic state to a glassy ferromagnetic state. The presence of glassy ferromagnetism at low temperature is confirmed from the M-H curve recorded at 5 K.

Human protein reference database--2006 update.

Human Protein Reference Database (HPRD) (http://www.hprd.org) was developed to serve as a comprehensive collection of protein features, post-translational modifications (PTMs) and protein-protein interactions. Since the original report, this database has increased to >20 000 proteins entries and has become the largest database for literature-derived protein-protein interactions (>30 000) and PTMs (>8000) for human proteins. We have also introduced several new features in HPRD including: (i) protein isoforms, (ii) enhanced search options, (iii) linking of pathway annotations and (iv) integration of a novel browser, GenProt Viewer (http://www.genprot.org), developed by us that allows integration of genomic and proteomic information. With the continued support and active participation by the biomedical community, we expect HPRD to become a unique source of curated information for the human proteome and spur biomedical discoveries based on integration of genomic, transcriptomic and proteomic data.