Raman spectroscopic study of phosphogypsum thermal reduction with the carbonaceous material.

Elemental sulphur (S) can be produced from hydrogen sulphide (H2S) in a PiPco or Iron process. In turn H2S can be stripped with carbon dioxide (CO2) from calcium sulphide (CaS) obtained from the thermal reduction of phosphogypsum with carbon. The reaction pathway for the thermal reduction of the phosphogypsum with graphite was studied using thermogravimetric analysis and in situ Raman spectroscopy.

In situ reduction study of cobalt model Fischer-Tropsch synthesis catalysts.

Fischer-Tropsch (FT) synthesis is an important process to manufacture hydrocarbons and oxygenated hydrocarbons from mixtures of carbon monoxide and hydrogen (syngas). The catalysis process occurs on, for example, cobalt metal surfaces at elevated temperatures and pressures. A fundamental understanding of the reduction pathway of supported cobalt oxides, and the intermediate species present during the activation, can assist in developing improved industrial supported cobalt catalysts.

Multimetal Fischer carbene complexes of Group VI transition metals: synthesis, structure and substituent effect investigation.

Fischer carbene complexes of tungsten with substituents containing up to two additional different transition metals, with all the metals in electronic contact with the carbene carbon atom, were synthesised and studied both in solution and in the solid state. For the complexes of the type [W(CO)(5){C(OR')R}], the substituents chosen were heteroaromatic 2-benzo[b]thienyl (2-BT), or 2-BT π-bonded to a chromium tricarbonyl fragment ([Cr(CO)(3)(2-η(6)-BT)]) or ferrocenyl (Fc) as the R-substituent, while the OR'-substituent was systematically varied between an ethoxy or a titanoxy group, to yield the complexes 1b (R' = Et, R = 2-BT), 2b (R' = Et, R = [Cr(CO)(3)(2-η(6)-BT)]), 3b (R' = TiCp(2)Cl, R = 21-BT), 4b (R' = TiCp(2)Cl, R = [Cr(CO)(3)(2-η(6)-BT)]), 5b (R' = Et, R = Fc) and 6b (R' = TiCp(2)Cl, R = Fc). The structural features and their relevance to bonding in the multimetal carbene compounds of both these tungsten and the analogous chromium complexes were investigated as they represent indicators of possible reactivity sites in multimetal carbene assemblies.

Impacts of prescribed fires on air quality over the Southeastern United States in spring based on modeling and ground/satellite measurements.

Prescribed burning is a large aerosol source in the southeastern United States. Its air quality impact is investigated using 3-D model simulations and analysis of ground and satellite observations. Fire emissions for 2002 are calculated based on a recently developed VISTAS emission inventory.

Modeling and spectroscopic studies of bisphosphonate-bone interactions. The Raman, NMR and crystallographic investigations of Ca-HEDP complexes.

Raman spectroscopy was used to study the interactions of bovine bone, hydroxyapatite (HA, as a model of bone) and calcium hydrogen phosphate (CaHPO4) with 1-hydroxyethylidene-1,1-diphosphonic acid, CH(3)C(OH)(PO(3)H(2))2 (HEDP, the oldest known member in the class of bisphosphonates (BPs) that is commonly used as (i) a reference compound for BP activity, a scale of a BP's potency, and (ii) a pain palliative agent). Raman spectra with diminished background fluorescence were obtained using a visible laser line of 514.5 nm.