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961.
Taylor F Mcaloon AJ Craig JC Yang P Wahjudi J Eckhoff SR 《Applied biochemistry and biotechnology》2001,94(1):41-49
The Quick-Germ process developed at the University of Illinois at Urbana-Champaign is a way to obtain corn oil, but with lower
capital costs than the traditional wet-milling process. Quick-Germ has the potential to increase the coproduct credits and
profitability of the existing dry-grind fuel ethanol process, but the fermentability of the corn remaining after oil recovery
has not been tested. Therefore, a series of pilot scale (50 L) fermentations was carefully controlled and monitored with unique
methods for standard inoculation and automatic sampling. It was found that the concentration of suspended solids was significantly
reduced in the Quick-Germ fermentations. When compared at the same concentration of fermentable sugars, the fermentation rate
and yield were not statistically different from controls. When Quick-Germ was integrated into a state-of-the-art dry-grind
fuel ethanol process, computer simulation and cost models indicated savings of approx $0.01/L of ethanol ($0.04/gal) with
the Quick-Germ process. Additional savings associated with the lower suspended solids could not be quantified and were not
included. However, the savings are sensitive to the price of corn oil.
Mention of brand or firm name does not constitute an endorsement by the U.S. Department of Agriculture over others of a similar
nature not mentioned. 相似文献
962.
(2S,6S)-2-(3-Bromopropyl)-1,7-dioxaspiro[5.5]undecane 3 was prepared by the addition of the acetylide derived from (4S)-4-benzyloxy-7-tert-butyldiphenylsilyloxyhep-1-yne 8 to δ-valerolactone 6 followed by treatment with hydrogen and palladium on charcoal which effected hydrogenation of the alkyne, hydrogenolysis of the benzyl ether and subsequent spiroacetal formation. The (4S)-stereochemistry in acetylene 8 was established by addition of trimethylsilylacetylene 10 to (2S)-epoxide 9, which in turn is derived from l-glutamic acid 11. 相似文献
963.
Deprotonation of a (−)-quinic acid-derived ketone {(2S,3S,4aR,8R,8aS)-8-[(tert-butyl(dimethyl)silyl)oxy]-2,3-dimethoxy-2,3-dimethylhexahydro-1,4-benzodioxin-6(5H)-one} using lithium hexamethyldisilazide (LHMDS) at −78 °C gave one regioisomeric enolate. The regiocontrol is governed by the axial β-silyloxy substituent and the resulting lithium enolate is stable towards β-elimination at temperatures up to −40 °C. It was found that the axial β-silyloxy group could be conveniently eliminated using 2.1 equiv of LHMDS at 0 °C for 1 h and that an equatorial β-alkoxy group was much more resistant to β-elimination. A chiral lithium amide base was used to overturn the inherent regioselectivity of ketone deprotonation with LHMDS. 相似文献
964.
Peter K. Claus Emmerich Jäger Alexis Setzer 《Monatshefte für Chemie / Chemical Monthly》1985,116(8-9):1017-1026
By reaction of anilines with dithioacetals of formaldehyde [in particular, with bis(methylthio)methane] andtert. butylhypochlorite the corresponding intermediate mono-sulfimides are formed which rearrange easily—after addition of triethylamine—to yield dithioacetals5 ofo-amino benzaldehydes.
Herrn emer. o. Univ. Prof. Dr.O. Hromatka zum 80. Geburtstag gewidmet. 相似文献
965.
Potentiometric titration was used to determine the logarithms of the stepwise equilibrium constants for the species formed between morpholine and formaldehyde in aqueous solution, ionic strength 0.5 and 2.5M (KCl) at 25 degrees C. The instrumental and computational techniques developed for metal-ligand stability constant determination were applied. Formaldehyde is equivalent to the metal-ion and is represented by M while neutral morpholine is equivalent to the ligand and is represented by L. The stability constants of the following equilibria were determined by non-linear regression (figures in parentheses are at ionic strength 2.5 M KCl): M + L left arrow over right arrow ML (hemi-aminal) logK(1) = 2.90 +/- 0.02 (2.980 +/- 0.004); ML + L left arrow over right arrow ML(2) (bis-aminal); log K(2) = 1.3 +/- 0.2 (1.41 +/- 0.07); MLH left arrow over right arrow ML + H(+) (protonated hemi-aminal) pK(a) = 5.87 +/- 0.01 (6.411 +/- 0.005); ML(2)H left arrow over right arrow ML(2) + H(+) (protonated bis-aminal) pK(a) = (7.6 +/- 0.2). the pK(a) of the protonated bis-aminal could only be determined at the higher ionic strength. The results are in good agreement with reported values determined using the classic formol titration. The automated titration system acquired the full time course of the pH change upon each titrant addition allowing a kinetic analysis to be performed as well as an equilibrium analysis. The forward and reverse rate constants for M + L left arrow over right arrow ML were 0.77M(-1) sec(-1) and 8.1 x 10(-4) sec(-1). respectively. 相似文献
966.
Reactions of α,β-unsaturated carbonyl compounds with Me3SiCH2MgCl, prepared from chloromethyltrimethylsilane [1], were examined. Unlike its lithium counterpart (Me3SiCH2Li), which adds to α,β-unsaturatedketones in the 1,2-sense, the Grignard reagent afforts γ silanes via a 1,4-addition sequence. This tendency is accentuated by the addition of Cu2Br2. Addition of the Grignard reagent to α,β-unsaturated aldehydes gives the simple 1,2-addition products. 相似文献
967.
Yi Yan Bai Gabriel Hose C.William McCurdy Howard S. Taylor 《Chemical physics letters》1983,99(4):342-346
The tunneling widths of high-energy metastable states lying in the classical irregular region of the Hénon-Heiles potential energy surface were calculated via complex analytical continuation of stabilization graphs. Mode specificity is demonstrated in that the lifetimes of normal-mode, local-bond-mode, and mode-mixed states at nearby energies differ by an order of magnitude. 相似文献
968.
An empirical potential energy function has been devised for the O-H·O hydrogen bond, for use with the MMI force field. The energy of the hydrogen bond is described as the sum of van der Waals, electrostatic and Morse components. The function has been used to calculate the potential energy hypersurface of the water dimer, and the results are compared with published ab initio molecular orbital studies. Satisfactory agreement is obtained except for orientations involving very short H·H contacts. The geometry and hydrogen bond energy of the equilibrium linear form of (H2O)2 are calculated to be r(O·O) = 2.84 Å, θ = 36°, ΔE = ?5.35 kcal mol?1, which are close to the values obtained by experiment, and from molecular orbital calculations. The relative importance of the electrostatic component of the empirical hydrogen bond energy is consistent with molecular orbital energy decomposition studies. The empirical function has also been used to calculate the energy of the water trimer in orientations which serve as models for the crystallographic bifurcated hydrogen bond. The results indicate that, in these orientations, the trimer is typically 0–3 kcal mol?1 more stable than the dimer, a result which is consistent with ab initio calculations. 相似文献
969.
970.
Kimberley A. C. C. Taylor 《Applied biochemistry and biotechnology》1995,53(3):215-227
A new spectrophotometric method for measuring fructose is presented. The method uses Tryptamine in HCl acid, is carried out
at 60°C, and is complete within 60 min. The assay is read at 518 nm and shows very low interference from other sugars. The
method can be used for fructose, fructosans, and inulin. 相似文献