Stereoselective Aromatic Ring Hydrogenation over Supported Rhodium Catalysts in Supercritical Carbon Dioxide Solvent.

The combination of supported rhodium metal catalysts and supercritical carbon dioxide solvent was effective for the stereoselective ring hydrogenations of aromatic compounds at low temperature. Higher solubility of hydrogen in supercritical carbon dioxide provides higher concentration of hydrogen on the rhodium surface, but lower that of the intermediate on rhodium surface, which suppresses the flipping of surface intermediate, leading to higher catalyst activities and cis selectivities to the corresponding ring-hydrogenated products as compared with those in organic solvents.

A method to minimize the global warming and environmental pollution.

There has been continuous increase in the level of CO2 in atmosphere. Therefore, it is essential to develop an economical and convenient process to reduce the concentration of CO2 in the atmosphere. In this study, we have proposed an economical and efficient adsorption method to minimize the environmental CO2. A fluidized bed adsorption column was used, fabricated using cast iron sheet. The low prize pyrolyzed biochar prepared from farming biomass (crushed fine powder) was used as an adsorbent to adsorb CO2 from the mixture of air and CO2 (99.5% air and 0.5% CO2). The experimental observation was taken for the % removal of CO2 from the mixture of air and CO2, development of adsorption isotherm and to study the effect of pressure and inlet gas flow rate on the amount of CO2 adsorbed per kg of biochar. The exhausted (CO2 adsorbed) biochar from the fluidized column was tested as a fertilizer for the wheat crop and it has given near about 10% increase in the height of wheat crop within the first 10 days after sowing the wheat seeds. On the basis of this experimentation, we have proposed a hypothetical method, using above mentioned fluidized bed column and biochar as adsorbent to reduce the CO2 concentration in the highly polluted regions.

Effect of calcination cycles on the preparation of tin oxide based traditional drug: studies on its formation and characterization.

The preparation method of metal based Indian traditional drugs involves conversion of a pure metal into its oxide by repeated high temperature calcination cycles. In this work, the effect of number of calcination cycles followed in the preparation of tin oxide based Ayurvedic drug, 'vanga bhasma' was studied by a systematic characterization of the drug samples after various calcination stages. It was found that tin was in the form of Sn4+ state and that the formation of SnO2 proceeded step-wise through Sn(OH)4.

Preparation and characterization of a copper based Indian traditional drug: tamra bhasma.

The copper based Indian traditional drug 'tamra bhasma' is administered for various ailments since long. Its synthesis involves treating metallic copper with plant juices and then repeated calcination in presence of air so that the metallic state is transformed into the corresponding oxide form traditionally known as 'bhasma'. In this work, we present a systematic characterization of this traditional drug using various techniques like X-ray diffraction (XRD), scanning electron microscopy (SEM)-energy dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR), thermogravimetry (TG) and surface area measurement. The results obtained were found to match very well with those of a standard copper oxide confirming the composition of the drug sample. In addition, some specific findings were also made which could help in interpreting the therapeutic properties of the traditional drug 'tamra bhasma'.