Development of Reference Shunt for Short‐Time Alternating High Current Tests and Study of Measuring System

Short‐circuit tests for power circuit breakers and others require alternative short‐time current measurement, from a few kA to over several tens kA. However, the reference measurement system as a national standard or a specified secondary standard instrument to directly perform comparative test as a complete calibration test in high current class has not yet been established globally. The Japan Short‐Circuit Testing Committee (hereinafter referred to as “JSTC”) has therefore developed a shunt resistor that can be used as a standard instrument for high current measurement. Reference system using this shunt resistor is also considered by JSTC. The performance of the newly developed shunt resistor has been checked through several methods, such as resistance measurement, high power current test, high frequency current test, temperature rise test, and interference test. The results of the tests proved satisfactory performance. Resistance of the shunt resistor before and after the tests was invariant and stable. This makes the shunt resistor adequate for a reference in practical use. In addition, evaluation of uncertainty of the whole reference system including this shunt resistor satisfactorily fulfills the requirements of IEC 62475 edition 1.0, 2010.     

Synthesis of a stabilizing control problem for a multimachine power system with phase shifter

A systematic procedure is considered for the synthesis of a stabilizing control method for a multimachine power system with phase shifter, taking into account the velocity governor. A new approach is presented, which uses a coordinate-transformation technique and an optimization technique. The application of this method to a stabilizing control problem for a power system is illustrated by considering a 3-machine power system with phase-shifter control, taking into account an additional control vector for the governing system with one time constant. The synthesized controls are then used to improve the power-system transient stability to a remarkable degree and to restore the power-system transients rapidly to the stable-equilibrium point. Numerical results arc given.     

Effects of Microwave Heating on the Molecular Species of Soybean Triacylglycerols

Microwave heating of whole soybeans resulted in an apparent increase of the total lipids. Molecular species of triacylglycerols were isolated from total lipids by a combination of silicic acid column chromatography and AgNO₃-thin layer chromatography (TLC). Fifteen molecular species of triacylglycerols were still found in whole soybeans following heat treatment. Microwave heating for about 5 min did not change all molecular species of soybean triacylglycerols nor cause a loss of unsaturated heat fatty acids. However, heat treatment for 8 min significant decrease not only in molecular species containing more than four double bonds, but also in the amount of diene and triene present in a triacylglycerol.     

A New Aroma-Bearing Substance from Shiitake, an Edible Mushroom

SUMMARY— Investigations on the physico-chemical properties and a sensory evaluation as a component of Shiitake flavor were carried out with lenthionine, a substance which was isolated from dried Shiitake mushroom. Lenthionine is practically insoluble in water but soluble in non-polar solvents. Its stability in an aqueous solution changes greatly with the pH of the solution.
Lenthionine was identified as a significant component in the aroma of Shiitake mushroom and its detectable threshold level is at a concentration between 0.27 and 0.53 porn in water. This new aroma-bearing substance will be used as a flavor additive in various foods.     

Effects of Microwave Treatment on the Trypsin Inhibitor and Molecular Species of Triglycerides in Soybeans

Whole soybeans at different moistures (8.6, 24.3, and 49.7%) were heated by exposure to microwaves at frequency of 2,450 MHz. The trypsin inhibitor in soybeans at 24.3% moisture, soaked for 1 hr, was completely inactivated after treatment for 4 min, which was shorter than the heating period (6 min) needed for unsoaked soybeans. However, the trypsin inhibitor in soybeans at 49.7% moisture, soaked for 5 hr, was not completely inactivated even after heating for 12 min. The loss of molecular species of soybean triglycerides containing more than four double bonds in a triglyceride was less for soaked soybeans than for soybeans before soaking (8.6% moisture).     

LIPID CLASSES, FATTY ACID COMPOSITIONS AND TRIACYLGLYCEROL MOLECULAR SPECIES FROM ADZUKI BEANS (VIGNA ANGULARIS)

The lipids extracted from adzuki beans grown in Japan were classified by thin-layer chromatography (TLC) into eight fractions. Molecular species and fatty acid distributions of triacylglycerols (TAGs) isolated from the total lipids in the beans were determined from a combination of argentation-TLC and gas chromatography. The major lipid components were phospholipids (PL; 63.5%) and TAG (21.2%), while hydrocarbons (5.1%), steryl esters (7.5%), free fatty acids (0.9%), diacylglycerols (1.3%) and monoacylglycerols (0.5%) were also present in minor proportions. Both major samples had high amounts of total unsaturated fatty acids, representing 62.1% for TAG and 65.9% for PL. Seventeen different molecular species were detected. The major TAG components were SMD (5.0%), S₂T (19.3%), SD₂ (13.8%), SMT (9.3%), MD₂ (4.5%), SDT (7.0%), D₃ (8.8%) and ST₂ (15.9%), where S, M, D and T denote a saturated fatty acid, a monoene, a diene and a triene, respectively.

PRACTICAL APPLICATIONS

This article describes the characteristics of lipid components, fatty acid compositions as well as the profiles of triacylglycerol (TAG) molecular species of adzuki beans. α-Linolenic (18:3 n -3) acid was detected as 24.8, 21.2 and 15.2% in the TAG, total lipids and phospholipids, respectively. The oil from legumes, except the profitable fatty acid content, could be a potential source of tocopherols. The data obtained in this study would be useful to both consumers and producers for manufacturing traditional adzuki confectionaries ( wagashi ) in Japan and elsewhere.     

Protein Content in Milk by Near-Infrared Spectroscopy

A corrected equation for the determination of protein content in oil/ water emulsions, developed previously, was applied for determination of protein content in milk and standard errors were satisfactory for the determination. This corrected equation can be used for determination of protein content in milk.     

Cholesterol Lowering Activity of Ropy Fermented Milk

The effect of ropy fermented milk on serum cholesterol in rats was studied. Basic diets containing slime-forming Lactococcus lactis subsp. cremoris SBT 0495, its non slime-forming variant SBT 1275, and acidified reconstituted skim milk, with 0.5% cholesterol added, were fed to F-344 rats for 7 days. Serum cholesterol level of rats fed the ropy fermented milk were the lowest among the three treatments. The serum high-density lipoprotein (HDL) cholesterol/total cholesterol ratio of rats fed ropy fermented milk was the highest. Slime materials produced by L. lactis subsp. cremoris SBT 0495 had a beneficial effect on rat cholesterol metabolism.     

IMMIGRANT NEIGHBORHOOD CONCENTRATION,ACCULTURATION AND OBESITY AMONG YOUNG ADULTS

Researchers repeatedly find that immigrants are healthier than their native‐born counterparts. Among immigrant children, however, findings are mixed. Moreover, the effect of neighborhood context on obesity has not been fully examined. Using the National Longitudinal Study of Adult Health, this study investigates the linkages between acculturation, neighborhood characteristics, and obesity among young adults, including the potential for residing in an immigrant neighborhood, to mediate the adverse effects of low neighborhood socioeconomic conditions on obesity. Consistent with the unhealthy assimilation model, an immigrant health advantage is found for first generation Asians. Conversely, a greater likelihood of being obese is found for second and third and higher generation Hispanics relative to third and higher generation Whites. Further, a high concentration of immigrants and linguistically isolated households appear to work as a buffer against health risks that relate to obesity, particularly in poor neighborhoods.