Mechanism of inactivation of heat-tolerant spores of Bacillus stearothermophilus IFO 12550 by Rapid Decompression

The effect of three rapid decompression methods to clear the mechanism of inactivation of heat tolerant spores of Bacillus stearothermophilus IFO 12550 was investigated. Pressurization of the spores at 200 MPa and 75°C for 60 min caused a kill of 10⁴ CFU/mL by the link-motion system but the nonrotational rod valve and E.G. seal methods gave a kill of about 10³ CFU/mL. Sterilization was due to the physical breakdown of spore coat, and was induced by its physical permeability of water at high pressure and temperature. Rapid decompression by the link-motion system at 200 MPa decreased the D-value of the spores from 3000 min (100°C, one atmosphere) to 6 min, 11 min, and 17 min at 95, 85, and 75°C, respectively.     

Raman Spectroscopy of Heat-Treated B2O3-SiO2 Glasses

Raman spectra were measured on B₂O₃-SiO₂ glasses heat-treated at different temperatures and for different periods of time. It was found that the intensity ratio of the 810- and 475-cm⁻¹ bands depended on the thermal history and composition of glass. The intensity vs heat-treatment temperature curve exhibited a maximum in the glass-transition temperature range. High-temperature Raman spectra were measured on 0.5B₂O₃-0.5SiO₂ glass, both with increasing and decreasing temperature, between room temperature and 600°C. Above 300°C with increasing temperature, the intensity of the 810-cm⁻¹ band decreased, whereas the intensity of the 475-cm⁻¹ band increased. The changes reversed with decreasing temperature. The reversible change of the intensity of the two bands was interpreted as a reversible formation and decomposition of boroxy rings with temperature. The reaction becomes very sluggish below the glass transition so that the intensity ratio stayed constant below 300°C.     

A THEORETICAL STUDY ON ADAPTIVE QUALITY CONTROL SYSTEMS

This paper is a study of an adaptive quality control system from a viewpoint of quality goal. The main purpose is to introduce a conceptual framework for setting up quality goals which are in accordance with the external environment and internal capacity of quality control systems. We apply a mathematical general systems approach.

The results of our paper are summarized as follows:

1)As important decision-making in adaptive QCS, the decision-making for estimalion of fitness and examination of attainability are proposed and formalized mathematically.

2)A refinement process is formalized in which models are revised according to the changes of market.

3)Basic steps for setting quality goals are obtained which are based on the above formalization.     

Studies on numerical site calibration over complex terrain for wind turbines

The estimation of wind turbine performance over complex terrain is very difficult because of the document of standard IEC61400-12 is adapted for flat or slightly complex topography.And the cost of constructing a meteorological mast is higher with scaling wind turbine up.We have proposed a numerical site calibration(NSC) technique in order to estimate the inflow velocity at the position of wind turbine by using CFD tool to calculate the flow field around the site.The present paper shows the problems for the ...     

INELASTIC CONSTITUTIVE PARAMETER IDENTIFICATION USING AN EVOLUTIONARY ALGORITHM WITH CONTINUOUS INDIVIDUALS

This paper presents a method for identifying the parameter set of inelastic constitutive equations, which is based on an evolutionary algorithm proposed by the authors. The advantage of the method is that appropriate parameters can be identified even when the measured data are subject to considerable errors and the model equations are inaccurate. The design of experiments suited for the parameter identification of a material model by Chaboche under the uniaxial loading and stationary temperature conditions was first considered. Then the parameter set of the model was identified by the proposed method from a set of experimental data. In comparison to those by other methods, the resultant stress–strain curves by the proposed method correlated well and reliably to the actual material behaviors. © 1997 by John Wiley & Sons, Ltd.     

MECHANICAL AND WATER-HOLDING PROPERTIES OF HEAT-INDUCED SOY PROTEIN GELS AS RELATED TO THEIR STRUCTURAL ASPECTS

The dependence of mechanical and water-holding properties of soy protein gels upon their structures was examined. Gels varying in extent of network formation were prepared by heating 20% paste of the isolated soy protein (ISP) containing L-cysteine hydrochloride (CySH) which has an ability to cleave intermolecular disulfide bonds. A rapid decrease in gel hardness and cohesiveness was observed with the increase in added amount of CySH up to 2.5 times 10^-5 mole/g ISP, and then a gradual decrease to 5.0 times 10^-5 mole/g ISP. The changes in these mechanical parameters appeared to depend on the degree of the network formation interpreted from the solubility changes of gels in the phosphate buffer containing 6 M urea. The relaxation time, estimated by compression stress relaxation, was also dependent on the degree of the network formation, while the modulus of elasticity was hardly affected. On the other hand, there was an inverse correlation between the NMR line width of the water proton and expressible water by the pressure method as an index of water-holding properties of the gel; the broader the former, the lesser the latter. The change in the water-holding capacity estimated from expressible water was also associated with that in the degree of the network formation. This confirms that both mechanical and water-holding properties of the gel are qualitatively governed by the extent of the structure formation controlled by the intermolecular disulfide bonds.     

WATER SOLUBLE VEGETABLE OLIGOPEPTIDES: COMPARATIVE STUDY ON ALCOHOL METABOLISM AND PLASMA AMINO ACID CONCENTRATIONS IN STROKE-PRONE SPONTANEOUSLY HYPERTENSIVE RATS

The purpose of the present study was to investigate the influence of vegetable oligopeptides on the reduction of blood ethanol. Studies were done after intragastric ethanol intake of 1 g/kg body weight ethanol in stroke-prone spontaneously hypertensive rats. Intragastric administered corn peptide caused a significant attenuation of the increase in blood ethanol levels. However, pea peptide did not influence blood ethanol levels. Pea peptide has a similar molecular weight as corn peptide. In the plasma, alanine, branched-chain amino acids, and proline concentrations were significantly elevated by the administrations of all oligopeptides as compared to the control group, but the leucine level was elevated more so by the corn peptide compared to wheat peptide or pea peptide. Consequently, these results suggested that corn peptide may lower the increase in blood ethanol levels after ethanol intake by the marked elevation of plasma alanine and leucine, especially leucine.     

Study on Acceleration Factor at 5000 h Multiple Stress Test and Aging Evaluation of EVA Insulator

The authors carried out an outdoor exposure test and the 5000 h multiple stress test to ethylene vinyl acetate (EVA) polymer composite insulator used for 22 kV distribution line and an attempt was made to estimate the acceleration factor of the 5000‐h multiple stress test corresponding to the climate condition of the Kyushu area. By comparing dry band arc cumulative charge of leakage current at 5000‐h multiple stress test with that in the outdoor exposure test, the authors estimated the acceleration factor of the 5000‐h multiple stress test to be about 20 times. The acceleration factor was found to almost agree with the evaluation result of the absorption of hydroxyl group by FT‐IR analysis and the surface roughness of the insulator, respectively. Finally, for the electrical property, the expected life of EVA insulator that the authors developed was confirmed to be more than 40 years.     

Side-wall effect of runner casing on performance of Darrieus-type hydro turbine with inlet nozzle for extra-low head utilization

A ducted Darrieus-type turbine has been proposed for hydropower utilization of extra-low head less than 2 m.Though the hydro turbine system,in general,might consist of an intake,runner casing section and a draft tube for higher efficiency operation,it was clarified in previous experiment that there was no need of the side-walls of runner casing section and a draft-tube for keeping the efficiency high in the case of duct with an inlet nozzle.This would yield a simplification of the structure of the turbine s...