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1.
D. Wiesenborn Z. Zbikowski H. Nguyen 《Journal of the American Oil Chemists' Society》1995,72(2):183-188
Extract of purple sunflower hulls is a potential red food colorant; however, suitable process conditions must still be identified.
Selected process variables were studied using bench-scale units to prepare, clarify, concentrate and spray dry extracts. Concentration
by evaporation at 32°C and addition of maltodextrin to 15% (wt/dry wt) prior to drying largely eliminated pigment degradation
during those steps. Relative to water extracts, extracts prepared with 5 to 15% ethanol in water generally yielded more pigment
with similar levels of degradation and loss during subsequent processing. Use of 5% ethanol/2% citric acid reduced yield by
about half relative to water, but gave a powder with a lower degradation index and wetting time. Percentage recovery of pigment
during concentration and drying was not greatly affected by solvent type or extraction temperature. 相似文献
2.
M.?NaczkEmail author R.?B.?Pegg R.?Zadernowski F.?Shahidi 《Journal of the American Oil Chemists' Society》2005,82(4):255-260
Possible use of canola hulls as a source of natural anti-oxidants was explored. Cyclone canola hulls were extracted with methanol
(30 to 80%, vol/vol) and acetone (30 to 80%, vol/vol). The free radical-scavenging activity of phenolic extracts so prepared
was evaluated using the 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical ion (ABTSo−), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, and chemiluminescence assays. The total content of phenolics in prepared
extracts from canola hulls ranged from 15 to 136 mg sinapic acid equivalents per gram of extract. Higher levels of condensed
tannins were detected in the acetone extracts than in the corresponding methanolic counterparts. Seventy and 80% (vol/vol)
acetone extracts displayed markedly stronger antioxidant activity than any of the other extracts investigated. Statistically
significant linear correlations were found between TEAC (Trolox equivalent antioxidant capacity) values (expressed in mM of
Trolox equivalents per gram of extract) and total pehnolics, TEAC and total condensed tannins (i.e., determined using the
modified vanillin and pronthocyanidin assays), as well as TEAC and protein precipitation activity of phenolic extracts (i.e.,
measured using the dye-labeled assay). The antioxidant activities of extracts as determined by the ABTSo− radical ion assay correlated highly with those of the chemiluminescence and DPPH radical assays. 相似文献
3.
4.
Encapsulation of geometric functions for ship structural CAD using a STEP database as native storage
It is difficult to support collaborative design with a conventional ship CAD system that manages design information using files. The file storage, however, can be replaced with a commercial database management system. This paper describes OpenDIS, which is an interface between the geometric modeling kernel and the DBMS. The main purpose of OpenDIS is to implement a CAD system that has the STEP database as the native storage. A prototype CAD system has been implemented using the OpenCascade geometric modeling kernel and ObjectStore, a commercial object-oriented DBMS. The STEP methodology is used for the database schema. This CAD system has been applied to the hull design process of a ship in order to verify the usefulness of the interface. 相似文献
5.
Microbial inhibitors arise from lignin, hemicellulose, and degraded sugar during pretreatment of lignocellulosic biomass. The fungus Coniochaeta ligniaria NRRL30616 has native ability to metabolize a number of these compounds, including furan and aromatic aldehydes known to act as inhibitors toward relevant fermenting microbes. In this study, C. ligniaria was used to metabolize and remove inhibitory compounds from pretreated rice hulls, which comprise a readily available agricultural residue rich in glucose (0.32–0.33 g glucan/g hulls) and xylose (0.15–0.19 g xylan/g hulls). Samples were dilute-acid pretreated and subjected to bioabatement of inhibitors by C. ligniaria. The bioabated rice hull hemicellulose hydrolyzates were then utilized for ethanol fermentations. In bioabated liquors, glucose was converted to 0.58% (w/v) ethanol by Saccharomyces cerevisiae D5a at 100% of theoretical yield, while fermentations of unabated hydrolyzates either failed to exit lag phase or had reduced ethanol yield (80% of theoretical). In fermentations using ethanologens engineered for conversion of pentoses, bioabatement of hydrolyzates similarly improved fermentations. Fermentation of xylose and arabinose by ethanologenic Escherichia coli FBR5 yielded 2.25% and 0.05% (w/v) ethanol from bioabated and unabated samples, respectively. Fermentations using S. cerevisiae YRH400 had decreased fermentation lag times in bioabated hydrolyzates. However, xylose metabolism in S. cerevisiae YRH400 was strongly affected by pH and acetate concentration. 相似文献
6.
TheprojectsubsidizedbyNational863planIntroductionSiliconCarbideWhisker(SiCw),asakindofnewhightechnologystructuralmaterial,isdeveloppingrapidlyinrecentovertenyears-Itscrystalstructureissimilartodiamond,andintheformofshortacicularfibre.Itsmeltingpointisover27OOt,densityis3.21g/cm',tensilestrengthis21OMPaandelasticmodulusi.[1J49ooMPa.Asaresult,SiCwhasmanyproperties,whichincludelowdensity,highhard-ness,highstrengthandmodulus,andhighcapacityofoxidationresistanceinhightemperature.Inrecentyear… 相似文献
7.
Jorge López Author Vitae Álvaro Barbero Author Vitae Author Vitae 《Pattern recognition》2011,44(3):607-614
The nearest point problem (NPP), i.e., finding the closest points between two disjoint convex hulls, has two classical solutions, the Gilbert-Schlesinger-Kozinec (GSK) and Mitchell-Dem’yanov-Malozemov (MDM) algorithms. When the convex hulls do intersect, NPP has to be stated in terms of reduced convex hulls (RCHs), made up of convex pattern combinations whose coefficients are bound by a μ<1 value and that are disjoint for suitable μ. The GSK and MDM methods have recently been extended to solve NPP for RCHs using the particular structure of the extreme points of a RCH. While effective, their reliance on extreme points may make them computationally costly, particularly when applied in a kernel setting. In this work we propose an alternative clipped extension of classical MDM that results in a simpler algorithm with the same classification accuracy than that of the extensions already mentioned, but also with a much faster numerical convergence. 相似文献
8.
Andrés?Moure Daniel?Franco Jorge?Sineiro Herminia?Domínguez María?José?Nú?ezEmail author 《Journal of the American Oil Chemists' Society》2003,80(4):389-396
The objective of this study was to analyze the factors affecting the ethanol extraction of Chilean hazelnut (Gevuina avellana) hulls to obtain antioxidant compounds. The effects of temperature on the kinetics of polyphenolics extraction and on the
antioxidant activities of the extracts were assessed. The radical-scavenging activities of the extracts were comparable with
that of BHA when used at the same concentration. The optimal temperature for the antioxidant activities of the extracts was
40°C. A four-stage cross-flow extraction was carried out and a four-stage countercurrent extraction was simulated, where each
stage lasted 30 min. Best results were obtained with countercurrent extraction, which produced an extract that showed 94.4%
α,α-diphenyl-β-picrylhydazyl radical inhibition, compared with 86.2% obtained in the first stage of cross-flow extraction
and 92.62% in a batch extraction that lasted 100 h. UV-vis and NIR spectra of extracts from cross-flow and from the simulated
countercurrent extraction revealed that the composition of extracts varied along the stages and was affected by the operational
strategy. 相似文献
9.
Anselmo Antunes Montenegro Luiz Velho Paulo C. P. Carvalho Jonas Sossai Jr. 《Journal of Mathematical Imaging and Vision》2007,29(2-3):119-130
In this work we propose a method for computing mesh representations of 3D objects reconstructed from a set of silhouette images.
Our method is based on the polygonization of volumetric reconstructions by using a modified version of the dual contouring method. In order to apply dual contouring on volumetric reconstruction from silhouettes we devised a method that is able
to determine the discrete topology of the surface in relation to the octree cells. We also developed a new scheme for computing
hermitian data representing the intersections of conic volumes with the octree cells and their corresponding normals with
subpixel accuracy. Due to the discrete and extremely noisy nature of the data used in the reconstruction we had to devise
a different criterion for mesh simplification that applies topological consistency tests only when the geometric error measure
is beyond a given tolerance. We present results of the application of the proposed method in the extraction of a mesh corresponding
to the surface of objects of a real scene. 相似文献
10.
Rodrigo Hernán Ordóñez-Hurtado 《International journal of control》2013,86(2):374-390
A new methodology to provide conclusive information about the existence/non-existence of a common quadratic Lyapunov function (CQLF) for a finite set of stable second-order systems is presented. Despite the high complexity of the CQLF problem, even in the case of N second-order systems, the results presented in this paper have a very simple and intuitive theoretical support, including topics such as classical intersection of convex sets and properties of convex linear combinations. Illustrative examples to show the performance of the proposed methodology are provided. 相似文献