Semi-continuous Hydrolysis of Sweet Potato Raw Starch by Chalara paradoxa Glucoamylase

Effect of preservatives was investigated on semi-continuous digestion of sweet potato raw starch by Chalara paradoxa glucoamylase which digests both raw and gelatinized starch. Potassium metabisulfite strongly inhibited raw starch digesting activity (RDA) although gelatinized starch digesting activity was only slightly inhibited. Potassium sorbate, among the preservatives examined, showed the weakest inhibition (below 10%) on RDA. In the presence of potassium sorbate, semi-continuous digestion of sweet potato raw starch in a 20L scale hollow fiber UF membrane pilot reactor proceeded efficiently at 30% (w/v) initial concentration of raw starch at pH 5.0 and 40°C. Glucose production was 5.7 to 6.0 g/hr/L.     

PURIFICATION AND CHARACTERIZATION OF ENDOPROTEASES FROM FRUIT BODY OF 'SHIMEJI'MUSHROOM, Lyophyllum aggregatum

Two proteolytic enzymes, L.a. protease I and II, were purified from the fruit body of 'shimeji'mushroom, Lyophyllum aggregatum, by ammonium sulfate precipitation, gel filtration, hydrophobic chromatography and ion-exchange chromatography. The enzymes were assayed using t-butyloxycarbonyl-Ala-Ala-Pro-Phe p-nitroanilide as a substrate. Each of the final enzyme preparations was homogeneous on polyacrylamide gel electrophoresis. The molecular weights of the enzymes were estimated as 44,000 and 46,000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The enzymes had the same optimal pH range of 7–8. Protease I preferentially hydrolyzed peptide bonds of the carboxyl-terminal sides of phenylalanine and leucine, and slowly hydrolyzed the peptide bonds of alanine, threonine and asparagine. On the other hand, protease II showed broader substrate specificity. Both enzymes were almost completely inactivated by diisopropyl phosphofluoridate, and partially inhibited by chymostatin. Protease I was also inhibited weakly by o-phenanthroline. These unusual proteases may have potential for specific food treatment applications.     

基于临界应力强度因子的胶接对接接头抗拉强度简便预测方法

为了能够对胶接对接接头进行抗拉强度预测,该文以有限元分析方法为基础,通过利用参考问题的无量纲应力强度因子、接头模型与参考问题模型之间应力值的比值以及接头抗拉强度的试验数值,得到了胶接对接接头的临界应力强度因子数值,从而提出了一个基于临界应力强度因子的胶接对接接头抗拉强度的简便预测新方法。该方法能够在保证精确度的基础上快速计算出胶接对接接头的应力强度因子,通过使用任意某一胶层厚度时的抗拉强度试验数值预测出其他胶层厚度时对接接头的抗拉强度数值。通过三种胶接对接接头的算例对比分析,证明了该方法的预测结果与实际结果非常接近,预测精度良好,便于工程应用。     

A Method for Estimating the Current–Flux Curve of a Single‐Phase Transformer for Electromagnetic Transient Simulations of Inrush Currents

When a transformer is energized, inrush currents whose magnitudes may reach tens of its nominal current occur. Since the inrush currents lead to a voltage drop, this may cause stops and malfunctions of electrical appliances. In addition, the overcurrents may cause an unnecessary operation of an overcurrent relay and affect the power quality of the distribution system. Currently, distribution system operators use current‐versus‐time curves of transformer inrush currents for the studies of such phenomena. However, the studies based on the current‐versus‐time curve give approximate results, and studies based on the current‐versus‐flux curve is required so as to obtain accurate results. Considering this point, this report proposes a method to convert a given current‐versus‐time curve to a current‐versus‐flux one for the case of single‐phase transformers. Using the current‐versus‐flux curve obtained, detailed simulations can be performed using an electromagnetic transient analysis program such as XTAP. In this report, the proposed method is validated by experimental results using a single‐phase transformer.     

Study of space charge effects on photoconduction in amorphous Se0.95Te0.05 films using a three electrode system

An experimental study of space charge effects on photoconduction in amorphous Se_0.95Te_0.05 films has been made using a three electrode system. The results indicate that the photoconduction in this material is dominated by holes and is governed by the built-in field created by space charges and the carrier injection from the electrical contacts, and that the three electrode system can be used for the investigation of the behaviour of space charges.     

THERMOELASTIC POTENTIAL FUNCTIONS IN TRANSVERSELY ISOTROPIC SOLIDS AND THEIR APPLICATIONS

An explicit solution composed of two thermoelastic potential functions is proposed in cylindrical coordinates and is applied to an analysis for steady-state, axially asymmetric thermal stresses in a long hollow cylinder. The solution is obtained with no assumptions of temperature fields. The temperature and stress fields in the long hollow cylinder made of magnesium are analyzed for the sake of application of the solution.     

A Highly-Sensitive Ba(Ti1—xSnx)O3 Thin Film Dielectric Bolometer for Uncooled IR Sensor

Ba(Ti_1—xSn_x)O₃ (BTS) ferroelectric thin films have been prepared by metal-organic decomposition method whose final annealing temperature was optimized to 700°C for dielectric bolometer. High temperature coefficient of dielectric constant (TCD) of 1–3%/K and low dielectric loss of 0.04 have been obtained in x = 0.15 and 0.17. Field-induced pyroelectricity of the BTS film was calculated to be an excellent value as high as 750 nC/cm²K. A series of dependence of DB output level were examined on important operation factors. The DB output level was increased when the period of supply voltage waveform is longer than both the electrical and thermal time constant of the DB detector. Finally, a stable infrared detection at temperature lower than 30°C was confirmed.     

MICROSTRUCTURE AND RHEOLOGICAL BEHAVIOR OF WHIPPING CREAM

The mechanism of the formation of a rigid foam structure during whipping of reconstituted whipping cream was investigated. The rheological properties of whipped cream were estimated from an analysis of shear creep curves by a four element model. The values of each element increased exponentially during the process of whipping. From cryo-SEM observation, the surface of air bubbles consisted of a thin membrane which was penetrated by fat globules. Also, fat globules in the serum were joined together by free fat to form a framework structure.
The relationship between the rheological properties and microstructure of whipped cream was deduced from the rheological properties of two model systems. It is believed that whipped cream is a mixed matrix of a SOB O/W structure and a stiffer W/O structure.     

Forecasting based on time series with correlated errors by information preserving filter Demand forecasting from information theory

An optimal forecasting technique has been developed by us from the viewpoint of mutual information. Generalization of this process is considered for the time series with correlated errors. The recommended technique is also compared with the prevailing method based on the Kalman filter in the optimality. The results indicate that the former may improve the latter in the effectiveness of forecasting.     

An extension of the application of information theory to forecasting

This paper presents an optimal forecasting technique from the viewpoint of mutua information. The recommended technique challenges the prevailing method based on the lvu-lma-n filter to the optimality, Test results indicate that the former may expand the latter in the effectiveness of forecasting.