An enzyme which hydrolyzes the rhamnose from ∞-solanine was isolated and partially purified by ammonium sulfate precipitation from the peels of Kennebec and Wauseon potatoes. Enzyme activity was found to be present in the 60 to 80% ammonium sulfate fraction. Enzyme activity was increased by the use of non-ionic detergents with a mixture of Triton X-100:Triton CF-54 (2:1, w/w) providing the greatest increase in activity. The pH optimum for the rhamnosidase for both varieties was found to be 6.0 while of the temperatures evaluated 42 °C was the optimum temperature. The effect of substrate concentration on enzyme activity was determined for both varieties and the Vmax and Km were calculated from Lineweaver-Burke double reciprocal plots. The Vmax and Km for the Kennebec and Wauseon rhamnosidases were found to be 0.27 mg/ml and 5.4 x 10-4 M and 0.48 mg/ml and 8.2 x 10-4 M, respectively. 相似文献
Propargyl alcohol was coupled to 2,4-hexadiyne-1,6-diol (HDD) and crystallized in the process of ultraviolet irradiation-induced
topochemical polymerization. The HDD polymer crystals were used as one component in the fabrication of organic photovoltaic
cells, in combination with fullerene as the electron acceptor. The various structures of the produced photovoltaic cells included
bilayer, trilayer, and bulk heterojunction structures. Their photovoltaic properties were analyzed in relation to crystal
structure, electrochemical properties, and band structure of the HDD polydiacetylene polymers. 相似文献
Using a strain-controlled rheometer, the steady shear flow properties of aqueous xanthan gum solutions of different concentrations
were measured over a wide range of shear rates. In this article, both the shear rate and concentration dependencies of steady
shear flow behavior are reported from the experimentally obtained data. The viscous behavior is quantitatively discussed using
a well-known power law type flow equation with a special emphasis on its importance in industrial processing and actual usage.
In addition, several inelastic-viscoplastic flow models including a yield stress parameter are employed to make a quantitative
evaluation of the steady shear flow behavior, and then the applicability of these models is also examined in detail. Finally,
the elastic nature is explained with a brief comment on its practical significance. Main results obtained from this study
can be summarized as follows: (1) Concentrated xanthan gum solutions exhibit a finite magnitude of yield stress. This may
come from the fact that a large number of hydrogen bonds in the helix structure result in a stable configuration that can
show a resistance to flow. (2) Concentrated xanthan gum solutions show a marked non-Newtonian shear-thinning behavior which
is well described by a power law flow equation and may be interpreted in terms of the conformational status of the polymer
molecules under the influence of shear flow. This rheological feature enhances sensory qualities in food, pharmaceutical,
and cosmetic products and guarantees a high degree of mixability, pumpability, and pourability during their processing and/or
actual use. (3) The Herschel-Bulkley, Mizrahi-Berk, and Heinz-Casson models are all applicable and have equivalent ability
to describe the steady shear flow behavior of concentrated xanthan gum solutions, whereas both the Bingham and Casson models
do not give a good applicability. (4) Concentrated xanthan gum solutions exhibit a quite important elastic flow behavior which
acts as a significant factor for many industrial applications such as food, pharmaceutical, and cosmetic manufacturing processes. 相似文献
An integrated platform for garment drape simulation system has been developed. In this system, garment patterns from conventional
two-dimensional CAD systems can be assembled into a three-dimensional garment on a parametrically resizable realistic human
body model. A fast and robust particle-based physical calculation engine has been developed for garment shape generation.
Then a series of geometric and graphical techniques were applied to create realistic impressions on simulated garments. This
system can be used as the rapid prototyping tool for garments in the future quick-response system. 相似文献
Five yellow disperse dyes were synthesized and their dyeing, fastness and photodegradation behaviors were investigated. It
was found that dyes derived from phenylindole and N-alkylaminobenzene showed dye uptake directly proportional to the dye concentration,
but the build-up of dyes derived from carbazole and pyridone were not good. The wavelength at maximum absorption, molar extinction
coefficient, and the tendency to the photodegradation were strongly dependent on the electron donating ability of the coupling
component. The dye, whose coupling component was phenylindole, possessed the excellent dyeing properties and the high degree
of lightfastness. UVA had an effect on the inhibition of the photodegradation especially for the easily photodegradable dyes. 相似文献
Conjoint analysis is a method for measuring and modeling consumer preferences for multiattribute alternatives. The purpose
of this research was to determine the preferred high-performance fabrics for a mountaineering jacket to identify those fabric
attributes best suited to the consumer’s needs. A conjoint analysis was conducted using 120 samples taken from mountaineering
club members including university students and amateur hikers, who ranked their preferences in the selection of a hypothetical
jacket based on the profiles derived from an orthogonal design. Our results show that the water/windproof attribute was the
most important in choosing a hypothetical jacket (27.6 %), followed by price (24.9 %), breathability (24.8 %), durability
(18.1 %), and weight (4.6 %). 相似文献
Polyurethane block copolymers chemically cross-linked by pentaerythritol, a four-way cross-linker, are tested for the shape
memory effect. One of the copolymers shows higher shape recovery than any other shape memory copolymer synthesized by us so
far. The copolymer maintains a surprising 94 % shape recovery after the third cyclic test. The four-way cross-linking by pentaerythritol
and interaction between hard segments are mainly responsible for the very high shape recovery. Tensile mechanical properties
also significantly improve by cross-linking. Glass transition temperature (Tg) slightly increases with cross-linking content. Other characterization such molecular weight, IR, and X-ray diffraction is
also carried out to understand the arrangement of copolymer chains. 相似文献
Color vegetation indices enable various precision agriculture applications by transforming a 3D-color image into its 1D-grayscale counterpart, such that the color of vegetation pixels can be accentuated, while those of nonvegetation pixels are attenuated. The quality of the transformation is essential to the outcomes of computational analyses to follow. The objective of this article is to propose a new vegetation index, the Elliptical Color Index (ECI), which leverages the quadratic discriminant analysis of 3D-color images along a normalized red (r)—green (g) plane. The proposed index is defined as an ellipse function of r and g variables with a shape parameter. For comparison, the ECI’s performance was evaluated along with six other indices, by using 240 color images as a test sample captured from four vegetation species under different illumination and background conditions, together with the corresponding ground-truth patterns. For comparative analysis, the receiver operating characteristic (ROC) and the precision–recall (PR) curves helped quantify the overall performance of vegetation segmentation across all of the vegetation indices evaluated. For a practical appraisal of vegetation segmentation outcomes, this paper applied Gaussian filtering, and then the thresholding method of Otsu, to the grayscale images transformed by each of the indices. Overall, the test results confirmed that ECI outperforms the other indices, in terms of the area under the curves of ROC and PR, as well as other performance metrics, including total error, precision, and F-score.
Journal of Soils and Sediments - Soil loss by rainfall is a serious problem in civil and environmental engineering. In this study, microbially induced calcite precipitation (MICP) was applied to... 相似文献
Journal of Soils and Sediments - Electrokinetic (EK) soil remediation is significantly affected by the electrode configurations. Therefore, this study was conducted to compare the performance of... 相似文献