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1.
A new fufurylidene derivative which tastes bitter was separated from lactose heated at 200°C for 20 hr by ethyl acetate extraction and preparative thin-layer chromatography. The compound was identified as the trans isomer of 1,6-anhydro-3,4-O-furfurylidene-β-D-galactopyranose by ultraviolet, infrared, mass and 1H-NMR spectroscopy. The compound and its cis isomer were identified in the reaction mixture of furfural and levogalactosan heated at 175°C for 2 hr with nitric acid. 相似文献
2.
REVERSE OSMOSIS CONCENTRATION of GREEN TEA JUICE 总被引:1,自引:0,他引:1
The reverse osmosis concentration of green tea juice was attempted by using membranes prepared from different polymeric materials. the pore sizes of the membranes were also changed in order to investigate the effect of the pore size on the membrane performance. Special attention was focused on the removal of caffeine from the tea juice while retaining other components such as polyphenols and amino acids. Since severe membrane fouling was observed while tea juice was treated at high concentrations, an attempt was made to describe the membrane fouling by a modified gel model that includes the effect of the interaction between the membrane and the tea juice components. 相似文献
3.
TAKAO MUKAI NAOFUMI WATANABE TAKAHIRO TOBA TAKATOSHI ITOH SUSUMU ADACHI 《Journal of food science》1991,56(4):1017-1018
A water soluble polysaccharide “kefiran” produced by Lactobacillus kefiranofaciens was examined for its gel-forming and rheological properties. Kefiran (3%) formed gel in the presence of ethanol (4–10%). The gel strength in 8% ethanol was comparable to that of 3% gelatin gel in water. Addition of casein (3%) increased gel strength 1.5–2.0 fold. The unique properties of kefiran may make it a useful food additive. 相似文献
4.
To improve the efficiency and fidelity of the numerical analysis for cascade flutter, we propose an efficient scale-resolving simulation method dedicated to time-periodic flows by incorporating the harmonic balance approach into the large-eddy simulation. This method combined convergence calculations of the steady-state problem based on the harmonic balance method for periodic components, and the nonlinear time-marching method for turbulent fluctuations. Using the proposed method, deterministic periodic components and stochastic turbulent fluctuations were calculated simultaneously, and the effect of turbulent fluctuations on deterministic periodic components was directly calculated without using turbulence models. In this paper, we explain the algorithm and feature of this simulation technique and present the results of the computation for channel flow excited in the streamwise direction as an analysis example using the proposed method. In order to validate the proposed method, an analysis of sinusoidally pulsating channel flow at the central friction-velocity Reynolds numbers Rer = 180 was conducted, confirming that the amplitude and phase of the mean velocity oscillation computed by the proposed method were in good agreement with those of the conventional LES. The present calculation achieved an order of magnitude improvement in computational efficiency compared to conventional LES. 相似文献
5.
SUSUMU MATSUURA KATSUHIKO SHIMASAKI HITOSHI SUGIMOTO 《Electrical Engineering in Japan》2016,195(4):1-8
Distribution surge arresters with an internal series gap have been installed on Japanese distribution lines at high density to reduce lightning‐related overvoltages. In contrast, surge arresters are sometimes damaged by direct lightning strokes, particularly in winter. Measurement of the insulation resistance between the terminals of the surge arrester and measurement of the dc discharge voltage of the surge arrester are generally adopted to detect damaged arresters. However, if metal‐oxide (MO) varistors are damaged and the internal series gap is not damaged, it is difficult to detect damaged arresters by the two conventional methods. Therefore, this paper presents a proposed detection method that can accurately detect damaged arresters. In the proposed method, first, the voltage between the terminals of the surge arrester is measured when the output of an impulse generator is applied to the surge arrester. Second, the damaged arrester is detected by comparison between its voltage waveform and the voltage waveform of the nondamaged arrester. The detection rate of damaged arresters by the proposed method is markedly higher than the rates of detection by the two conventional methods. 相似文献
6.
SUSUMU NISHIGAKI KANJI MURANO AKIO OHKOSHI 《Journal of the American Ceramic Society》1982,65(11):554-560
The dielectric behavior of (1- x )(Sr0.5 Pb0.25 Ca0.25 ) TiO3 -x(Bi2 O3 ·3TiO2 ) was studied using x=O to 8.25 mol%. Around the point at which x equals 1.56 mol%, the following phenomena were observed: (1) At −;22°C, the weak field permittivity increased substantially with a dc bias field, becoming more than twice the zero bias value at a field of 3 kV/mm; (2) the permittivity peak shifted markedly toward a high temperature under a dc bias field; (3) relaxation behavior was evident; and (4) there are large hysteresis loops at low temperatures and double hysteresis loops, which seem to be related to a field-enforced ferroelectric phase, in a wide temperature range. We used dielectrics with an optimized composition of x =4.30 mol% in a small, highly reliable, 15-kV high-voltage ceramic capacitor. 相似文献
7.
Temperature response functions have been developed to investigate sensor design and divertor heat flux estimation in magnetically confined plasmas. The time-dependent heat flux can be derived by fitting the response function to experimental thermocouple(TC) data. Because the TC signals have a time delay to transit events such as discharge start or confinement transition, the time delay is taken into account in a temperature response function. Such a function accurately describes the signal from ... 相似文献
8.
Development of the efficient hot metal dephosphorization processes during steelmaking process is one of the most essential topics for the production of high grade clean steels. Since the formation of solid solution composed of tricalcium phosphate and dicalcium silicate could obtain a considerable mass transfer of phosphorus from liquid slag into solid phase during hot metal dephosphorization, itcould obviously sustain a high phosphatecapacityof theliquid slag without huge consumption of lime or addition of fluxes, such as fluorite. The above outlines are the main idea of multi phase flux dephosphorization. For the last few decades, many studies have been done towards the scientific principles and the commercial utilization of this technique. However, the reaction mechanism by using multi phase fluxes remains unclear even by now due tolack of evidence. Based on those previous works, providing a reliable and available phase diagram for the fundamental understanding of the reaction mechanism of multi phase flux dephosphorization has become the main purpose of present research. As well known, the CaO-SiO2-FeO-P2O5 slag is the main component of current steelmaking process. Hence the CaO-SiO2-FeO-P2O5 system at equilibrium has been studied at 1673K with low oxygen partial pressure. The solid phase coexisting with liquid flux is approved to be the solid solution composed of CaO, SiO2 and P2O5. Phosphorus distributes mainly in solid solution rather than liquid phase. 相似文献
9.
ABSTRACT: Pectin was extracted, then pectic acid was purified without autolysis. It contained 93.7% uronic acid and 6.3% neutral sugar. Using exopolygalacturonase, exopolygalacturonate lyase and endopolygalacturonase, the molecular composition of onion pectic acid was determined; the proportion of galacturonic acid residue from the nonreducing end to rhamnogalacturonan (RG) was 9.7%, while that of the reducing end to RG was 46.7%. From RG to RG, the proportion of galacturonic acid residue was 41.0%, and the RG region was 2.6%. 相似文献
10.
Reverse osmosis experiments were performed to concentrate the green tea juice, and the experimental data was analyzed by using a set of transport equations together with osmotic pressure and density data of the green tea juice. the transport parameters obtained numerically by the above analytical procedure were then used to calculate several dimensionless quantities that can characterize a reverse osmosis module. an example of module design calculation was attempted using the dimensionless parameters so obtained. It has been found that an increase in operating pressure reduces the module length significantly when the feed tea juice concentration is high. an increase of the mass transfer coefficient on the high pressure side of the membrane has the same effect. 相似文献