The functional properties of Caryodendron orinocense protein product were investigated and compared with those of soybean (Glycina maxima). The product protein content was 24.47 g/100 g (Nx6.25). Solubility increased at both sides of the isoelectric point (pH 4.0) and with increased NaCl concentration up to 0.5M. Compared with soybean flour (50% protein), the protein product exhibited higher water and oil absorption, but lower emulsifying activity, emulsion stability, foaming capacity, and foam stability, the last one increase at higher pH. Emulsifying activity, foaming capacity, and foam stability were ionic strength dependent. C. orinocense protein product increased its emulsifying activity steadily from 0.05M to 0.75M NaCl, while it remained almost constant for soybean flour. Foaming capacity increased drastically at pH 10. The minimum time and concentration to form a gel was 20% in 4 min and 10% in 8 min for the Caryodendron protein product and soybean flour, respectively. The bulk density was 0.5056+/-0.0041 g/mL. 相似文献
An efficient synthetic route to pure, high molecular weight poly(p-hydroxystyrene) is reported. The route involves synthesis of a new monomer, p-tert-butoxycarbonyloxystyrene, polymerization by radical initiation or by cationic initiation in liquid SO2, followed by thermolysis or acidolysis of the tert-butoxycarbonyl protecting group. Porous, crosslinked resin beads containing the nucleophilic, phenol pendant group have been prepared in a similar fashion from the precursor terpolymer of p-tert-butoxycarbonyloxystyrene, styrene and divinylbenzene. The utility of this resin for solid-phase synthesis has been demonstrated. 相似文献
Summary: Syndiotactic polystyrene (sPS)/organophilic clay nanocomposites were obtained by in situ coordination‐insertion polymerization of styrene. Two cationic surfactants (alkylammonium and alkylphosphonium) were used for the intercalation of montmorillonite (MMT). For each organically modified clay, three protocols were performed using an MAO‐activated hemi‐metallocene catalyst, in order to compare the influence of experimental conditions on the composite microstructure and on its thermal stability. The microstructures of nanocomposites were investigated by wide angle X‐ray scattering and DSC. Partially exfoliated or intercalated materials were obtained in all cases and a decrease of crystallinity is observed. Thermal properties were also studied by DSC and thermogravimetric analysis. The presence of clay does not have a strong influence on the sPS thermal transitions but the thermal decomposition process of the material was slowed down in the presence of few organoclay percents, particularly in the degradation beginning. The influence of these two organically modified clays on the thermal stability of the material is discussed.
Gel and suspension formed from the combination of cloisite with toluene (left) and styrene (right), respectively. 相似文献
A kinetic study for the one-step conversion of synthesis gas to gasoline on a ZnO–Cr2O3–ZSM-5 catalyst is described. On this catalyst, three reactions are involved in the overall transformation of synthesis gas: the methanol synthesis, the conversion of methanol to hydrocarbons and the water–gas shift reaction. Under the operating conditions selected for the study, it was found that the water–gas shift was at equilibrium and the methanol was completely converted to hydrocarbons. Consequently, it was postulated that the kinetics of the limiting reaction step, the methanol synthesis on the ZnO–Cr2O3 component, was the one that controls the overall reaction rate. Three kinetic model equations describing the rate of synthesis gas conversion on the bifunctional catalyst, were considered to fit the data of the experimental runs performed in a Berty well-mixed reactor. Those equations were derived under very special conditions where the methanol decomposition term could be neglected. It was also observed that in the kinetic equations a term involving the fugacity of CO2 was required to predict the rate properly. The catalyst deactivation was also taken into account in the analysis. 相似文献
In this paper we present a new credal classification rule (CCR) based on belief functions to deal with the uncertain data. CCR allows the objects to belong (with different masses of belief) not only to the specific classes, but also to the sets of classes called meta-classes which correspond to the disjunction of several specific classes. Each specific class is characterized by a class center (i.e. prototype), and consists of all the objects that are sufficiently close to the center. The belief of the assignment of a given object to classify with a specific class is determined from the Mahalanobis distance between the object and the center of the corresponding class. The meta-classes are used to capture the imprecision in the classification of the objects when they are difficult to correctly classify because of the poor quality of available attributes. The selection of meta-classes depends on the application and the context, and a measure of the degree of indistinguishability between classes is introduced. In this new CCR approach, the objects assigned to a meta-class should be close to the center of this meta-class having similar distances to all the involved specific classes? centers, and the objects too far from the others will be considered as outliers (noise). CCR provides robust credal classification results with a relatively low computational burden. Several experiments using both artificial and real data sets are presented at the end of this paper to evaluate and compare the performances of this CCR method with respect to other classification methods. 相似文献