Morphological and Structural Characterization of Cro2/Cr2o3 Films Grown by Laser-CVD

This work reports on the synthesis of chromium (III, IV) oxides films by KrF laser-assisted CVD. Films were deposited onto sapphire substrates at room temperature by photodissociation of Cr(CO)6 in dynamic atmospheres containing oxygen and argon. A study of the processing parameters has shown that partial pressure ratio of O2 to Cr(CO)6 and laser fluence are the prominent parameters that have to be accurately controlled in order to co-deposit both crystalline oxide phases. Films consistent with such a two-phase system were synthesised for a laser fluence of 75 mJ cm-2 and a partial pressure ratio about 1. PACS: 81.15.Fg, 81.15.Kk, 81.05.JeComment: 17 pages, 4 figure

Cr2O3 thin films grown at room temperature by low pressure laser chemical vapour deposition

Chromia (Cr2O3) has been extensively explored for the purpose of developing widespread industrial applications, owing to the convergence of a variety of mechanical, physical and chemical properties in one single oxide material. Various methods have been used for large area synthesis of Cr2O3 films. However, for selective area growth and growth on thermally sensitive materials, laser-assisted chemical vapour deposition (LCVD) can be applied advantageously. Here we report on the growth of single layers of pure Cr2O3 onto sapphire substrates at room temperature by low pressure photolytic LCVD, using UV laser radiation and Cr(CO)6 as chromium precursor. The feasibility of the LCVD technique to access selective area deposition of chromia thin films is demonstrated. Best results were obtained for a laser fluence of 120 mJ cm-2 and a partial pressure ratio of O2 to Cr(CO)6 of 1.0. Samples grown with these experimental parameters are polycrystalline and their microstructure is characterised by a high density of particles whose size follows a lognormal distribution. Deposition rates of 0.1 nm s-1 and mean particle sizes of 1.85 {\mu}m were measured for these films.Comment: 16 pages, 6 figures, accepted for publication in Thin Solid Film

Characterization of explosives processing waste decomposition due to composting. Final report

The objective of this work was to provide data and methodology assisting the transfer and acceptance of composting technology for the remediation of explosives-contaminated soils and sediments. Issues and activities addressed included: (a) chemical and toxicological characterization of compost samples from new field composting experiments, and the environmental availability of composting efficiency by isolation of bacterial consortia and natural surfactants from highly efficient composts, and (c) improved assessment of compost product suitability for land application

Characterization of explosives processing waste decomposition due to composting

Static pile and mechanically stirred composts generated at the Umatilla Army Depot Activity in a field composting optimization study were chemically and toxicologically characterized to provide data for the evaluation of composting efficiency to decontaminate and detoxify explosives-contaminated soil. Characterization included determination of explosives and 2,4,6,-trinitrotoluene metabolites in composts and their EPA Synthetic Precipitation Leaching Procedure Leachates, leachate toxicity to Ceriodaphnia Dubia and mutagenicity of the leachates and organic solvent extracts of the composts to Ames bacterial strains TA-98 and TA-100. The main conclusion from this study is that composting can effectively reduce the concentrations of explosives and bacterial mutagenicity in explosives -- contaminated soil, and can reduce the aquatic toxicity of leachable compounds. Small levels of explosive and metabolites, bacterial mutagenicity, and leachable aquatic toxicity remain after composting. The ultimate fate of the biotransformed explosives, and the source(s) of residual toxicity and mutagenicity remain unknown

THE ASTIS TRIAL: AUTOLOGOUS STEM CELL TRANSPLANTATION VERSUS IV PULSE CYCLOPHOSPHAMIDE IN POOR PROGNOSIS SYSTEMIC SCLEROSIS, FIRST RESULTS

Analysis and support of clinical decision makin

THE ASTIS TRIAL: AUTOLOGOUS STEM CELL TRANSPLANTATION VERSUS IV PULSE CYCLOPHOSPHAMIDE IN POOR PROGNOSIS SYSTEMIC SCLEROSIS, FIRST RESULTS

Analysis and support of clinical decision makin