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Molecular mechanics (MM) simulations have been used to model two small crystals of cellulose Ibeta surrounded by water. These small crystals contained six different extended surfaces: (110), (11 0), two types of (100), and two types of (010). Significant changes took place in the crystal structures. In both crystals there was an expansion of the unit cell,(More)
Previous kinetic modeling and bench-scale demonstration efforts using batch, percolation, or plug-flow reactors for the dilute sulfuric acid hydrolysis of cellulose have concluded that glucose yields above 70% of theoretical were not possible. This has been explained to be a result of reactions involving glucose or the cellulose itself in a destructive(More)
Hydrolysis of α-cellulose by H 2 SO 4 is a heterogeneous reaction. As such the reaction is influenced by physical factors. The hydrolysis reaction is therefore controlled not only by the reaction conditions (acid concentration and temperature) but also by the physical state of the cellulose. As evidence of this, the reaction rates measured at the(More)
Cost reductions for pretreatment and bioconversion processes are key objectives necessary to the successful deployment of a bioethanol industry. These unit operations have long been recognized for their impact on the production cost of ethanol. One strategy to achieve this objective is to improve the pretreatment process to produce a pretreated substrate(More)
Recent research work in-house both at Auburn University and National Renewable Energy Laboratory has demonstrated that extremely low concentrations of acid (e.g., 0.05-0.2 wt% sulfuric acid) and high temperatures (e.g., 200-230 degrees C) are reaction conditions that can be effectively applied for hydrolysis of the cellulosic component of biomass. These(More)
Antibody prepared against 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase of rat liver can be shown to inhibit this enzyme in extracts prepared from cultured Chinese hamster ovary (CHO-K1) cells. The molecular weight (53,000) of the HMG-CoA reductase subunits of rat liver and Chinese hamster liver is identical with a [35S]methionine-labeled(More)
The kinetics of cellulose hydrolysis under extremely low acid (ELA) conditions (0.07 wt%) and at temperatures >200 degrees C was investigated using batch reactors and bed-shrinking flow-through (BSFT) reactors. The maximum yield of glucose obtained from batch reactor experiments was about 60% for alpha-cellulose, which occurred at 205 and 220 degrees C. The(More)
Hydrolysis of alpha-cellulose by H2SO4 is a heterogeneous reaction. As such the reaction is influenced by physical factors. The hydrolysis reaction is therefore controlled not only by the reaction conditions (acid concentration and temperature) but also by the physical state of the cellulose. As evidence of this, the reaction rates measured at the(More)
Regulation of 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase activity and synthesis by 25-hydroxycholesterol is aberrant in a somatic cell mutant of the Chinese hamster ovary K1 cell auxotrophic for mevalonate by virtue of a defect in HMG-CoA synthase activity. Normal regulation of HMG-CoA reductase activity and synthesis in this mutant by(More)