7,702 research outputs found
Bioethanol from Germinated Grains.
The most well-known way to produce bioethanol is by the enzymatic hydrolysis and fermentation of starch. In a new project “BioConcens” (2007) sponsored by DARCOF (DAnish Research Center for Organic Food and farming) one aim is to develop a combined ethanol and biogas production for use in organic farming using starch containing biomass. Natural enzymes from cereals will be used for hydrolysis of starch to glucose in accordance with technology in brewing technology. Commercial enzymes are often produced from gene-modified organisms and will therefore not be used in the suggested organic context or process.
A preliminary study was performed in which grains of wheat, rye, and barley were germinated using traditional methods applied in malting for beer production. During malting the amylase enzymes present in the grain are activated (autoamylolytic effect). Three steps were applied in the malting process; steeping, germination, and drying of the grains. After malting the grains were milled and mixed with water to 13% DM, cooked at 57.5C for 2 hours (to activate the enzymes), and cooled to 30C before adding Bakers Yeast.
The results of this study indicate that efficient hydrolysis of starch can be achieved by activation of autoamylolytic enzymes in cereal grains after a malting process. The ethanol yields obtained in the autoamylolytic hydrolysis was comparable (or slightly higher) to that of reference experiments using commercial enzymes (amylases). The highest ethanol yield was obtained with wheat (0.34 g/g DM grain), followed by barley (0.31 g/g DM grain), and rye (0.29 g/g DM grain)
Is my ODE a Painleve equation in disguise?
Painleve equations belong to the class y'' + a_1 {y'}^3 + 3 a_2 {y'}^2 + 3
a_3 y' + a_4 = 0, where a_i=a_i(x,y). This class of equations is invariant
under the general point transformation x=Phi(X,Y), y=Psi(X,Y) and it is
therefore very difficult to find out whether two equations in this class are
related. We describe R. Liouville's theory of invariants that can be used to
construct invariant characteristic expressions (syzygies), and in particular
present such a characterization for Painleve equations I-IV.Comment: 8 pages. Based on talks presented at NEEDS 2000, Gokova, Turkey, 29
June - 7 July, 2000, and at the AMS-HKMS joint meeting 13-16 December, 2000.
Submitted to J. Nonlin. Math. Phy
Efficient Notification of Meeting Points for Moving Groups via Independent Safe Regions
published_or_final_versio
n-d-topological data structures: some theoretical and pragmatic considerations for GI-Science
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