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High Product Yields (high + product_yield)
Selected AbstractsSynthesis of Anatase TiO2 Nanoparticles with ,-Cyclodextrin as a Supramolecular ShellCHEMISTRY - AN ASIAN JOURNAL, Issue 5 2006Landong Li Abstract We report a novel, green hydrothermal-synthesis route to well-dispersed anatase TiO2 nanoparticles with particle sizes of 9,16,nm in the presence of ,-CD (,-cyclodextrin). During the synthesis process, the CD-containing synthesis mixture assembled in both longitudinal and latitudinal directions. Driven by the interaction between molecules, the ,-CDs assembled in the longitudinal direction to form long-chain compounds, whereas in the latitudinal direction, they tended to form regular aggregates through coordination with the Ti species from the hydrolysis of tetrabutyl titanate. In view of the effect of the coordination and the steric hindrance of ,-CDs as a supramolecular shell, homogeneous nuclei and slow growth of TiO2 crystals during the synthesis process was observed, which was responsible for the formation of uniform TiO2 nanoparticles. The low ,-CD dosage and the high product yield (>90,%) demonstrated well the potential of this synthesis route in the large-scale industrial production of anatase nanoparticles. [source] Supercritical Fluid,Liquid,Solid (SFLS) Synthesis of Si and Ge Nanowires Seeded by Colloidal Metal Nanocrystals,ADVANCED MATERIALS, Issue 5 2003T. Hanrath Abstract Semiconductor nanowires, 5 to 20 nm in diameter and micrometers in length, appear to be promising candidates for a variety of new technologies, including computing, memory, and sensor applications. Suitable for these applications, silicon (Si) and germanium (Ge) nanowires ranging from 4 to 30 nm in diameter and micrometers in length can be produced in high temperature supercritical fluids by thermally degrading organosilane or organogermane precursors in the presence of organic-monolayer-protected gold nanocrystals. Although gas phase vapor,liquid,solid (VLS) methods can be used to produce a variety of different nanowire materials, high temperature supercritical fluids provide wire size control through nanocrystal size selection prior to synthesis, and high product yields due to the high precursor solubility. [source] Effect of oxygen transfer rates on alcohols production by Candida guilliermondii cultivated on soybean hull hydrolysateJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2 2009Āngela Cristina Schirmer-Michel Abstract BACKGROUND: In this research the use of soybean hull hydrolysate (SHH) as substrate for xylitol and ethanol production using an osmotolerant strain of Candida guilliermondii was studied. The production of alcohols was investigated in batch cultivations in which the variable parameter was the volumetric oxygen mass transfer coefficient (kLa) obtained from three different conditions of air supply: anaerobic (150 rpm, no aeration); microaerobic (300 rpm, 1 vvm), and aerobic (600 rpm, 2 vvm), corresponding to kLa values of 0; 8; and 46 h,1, respectively. RESULTS: SHH, although presenting a very high osmotic pressure (1413 mOsm kg,1), was completely metabolized under aerobic conditions with high biomass productivities of 0.49 g cells (L h),1, with little formation of ethanol. Xylitol was produced under microaeration, with product yield of 0.22 g g,1 xylose, with the formation of glycerol as a by-product. No xylose was metabolized under anaerobic conditions, but ethanol was produced from hexoses with high product yields of 0.5 g g,1. CONCLUSION: These results suggest that the hydrolysis of soybean hull and its conversion to ethanol and other alcohols could be an important use of this agro-industrial waste, which could be used for biofuel, xylitol or biomass production, depending on the aeration conditions of the cultures. Copyright © 2008 Society of Chemical Industry [source] Simultaneous expression and maturation of the iron-sulfur protein ferredoxin in a cell-free systemBIOTECHNOLOGY & BIOENGINEERING, Issue 1 2006Marcus E. Boyer Abstract The model iron-sulfur (Fe-S) protein ferredoxin (Fd) from Synechocystis sp. PCC 6803 has been simultaneously produced and matured in a cell-free production system. After 6 h of incubation at 37°C, Fd accumulated to >450 µg/mL. Essentially all was soluble, and 85% was active. Production and maturation of the protein in the cell-free system were found to be dependent in a coupled manner on the concentration of the supplemented iron and sulfur sources, ferrous ammonium sulfate and cysteine, respectively. The recombinant expression of ISC helper proteins during cell extract preparation did not increase cell-free Fd accumulation or activity, although the efficiency of iron and cysteine utilization increased. Fd maturation was independent of protein production rate, and proceeded at a constant rate throughout the period of active translation. In addition, incubation of denatured apo Fd with cell-free reaction components resulted in recovery of Fd activity, supporting the interpretation that maturation mechanisms did not act co-translationally. Incubation at 28°C increased total and active protein accumulation, but decreased the ratio of active to total Fd produced. In summary, the high product yields and folding efficiency make the cell-free system described here an attractive platform for the study of Fe-S protein production and maturation. The system enables both small-volume, high throughput investigations as well as larger scale production. To our knowledge, this is the first demonstration of directed, high-yield production and maturation of an Fe-S protein in a cell-free system. © 2006 Wiley Periodicals, Inc. [source] | ||||||||||