Vacuum seal for a rectangular flange

A new vacuum seal for a rectangular flange used in r.f. equipments, was developed. The vacuum seal consists of a recess with a flat surface, machined into a rectangular flange, a rectangular metal gasket with a raised projection on one face, and a mating flange with a recess and raised projection. No leak greater than 1 × 10⁻¹⁰ Pa m³/s was found in leak tests, before and after baking cycles (100 °C, 12 h).     

Preparation of helical carbon and graphite films using morphology-retaining carbonization

Helical carbon and graphite films were prepared from iodine-doped helical polyacetylene (H-PA) film using currently developing morphology-retaining carbonization. It was found from scanning electron microscopy (SEM) observations that the hierarchical helical morphology of the H-PA film remains unchanged even after the carbonization at 800 °C. Besides, the weight loss of the film due to the carbonization was very small, which was only a few percent to the weight of the film before doping. Furthermore, the graphite film prepared by the subsequent heating at 2600 °C still retained the same morphology as those in the original H-PA film and in the helical carbon film prepared at 800 °C. X-ray diffraction (XRD) and Raman scattering measurements were then pursued. The results showed that graphitic crystallization proceeds in the carbon film through the heat treatment at 2600 °C. Transmission electron microscopy (TEM) image of a single helical graphitic fibril was also observed by ultrasonicating the graphite film in ethanol. Carbonization of the H-PA films by way of iodine doping was found to afford helical carbon and graphite films, where spiral morphologies and even helical fibril structures were completely preserved.     

Fluctuations in Tracer Amounts in a Compartmental System with a Markovian Transition Process

This communication considers a method for evaluating fluctuations in the integral type output of a linear time-invariant compartmental system with a Markovian transition process. First, we derived a mathematical formula to calculate variances and covariances of integral type. outputs, as with radioisotope data, when transition rates are known. Then, an estimate for the upper limits of variances and covariances, i.e., 1/2?initial dose, when the transition rates are not given beforehand, was introduced.     

Reactive extraction of diols with phenyl boronic acid and trioctylmethylammonium chloride as coextractants and quantitative structure–property relationship of their extraction behaviors

BACKGROUND: Diols that can be produced biologically have attracted much attention because of the increased cost of producing them chemically. The cost of separating the diols from the broth forms a major part of the total cost of microbial production. Reactive extraction using organoboronate is one promising method for recovering diols from the dilute aqueous solution. RESULTS: A basic investigation of solvent extraction of diols was conducted at 303 K employing phenylboronic acid and trioctylmethylammonium chloride as coextractants in the mixed solvent. Both the tetrahedral boronate anion complex and trigonal boronate neutral complex were extracted. 1,3‐diols and vicinal diols were extracted, but 1,4‐diol was not extracted. Extraction equilibrium constants were correlated with the enthalpies of formation of the complexes, which were calculated by molecular modeling with semi‐empirical molecular orbital calculations considering the solvent effect. CONCLUSION: The complex extraction behaviour of diols with phenylboronic acid and quaternary ammonium salt can be predicted by using the quantitative structure–property relationship (QSPR). Copyright © 2009 Society of Chemical Industry     

Oxygen Potential Measurement of Americium Oxide by Electromotive Force Method

The oxygen potentials of AmO_{2− x} were measured in the x range of 0.01–0.5 and the temperature range of 1000–1333 K by the electromotive force method. The oxygen potentials at 1333 K were −19.83 kJ/mol for x =0.019 and −319.1 kJ/mol for x =0.485, which were higher than those of CeO_{2− x} by approximately 200 kJ/mol for the corresponding x values. From the dependence of the oxygen potentials on x and temperature, a tentative phase diagram of Am–O system was proposed, which suggested the presence of the intermediate phases of Am₇O₁₂ and Am₉O₁₆ in the Am–O system.     

Study on sustainable redevelopment of a densely built-up area in Tokyo by introducing a distributed local energy supply system

“Distributed local energy systems” had been expected to rationalize the supply of energy to built-up areas, but until now very little research has been performed to estimate the effect of their application to actual cities. In this research, therefore, a future vision for the year 2030 in the Sancha Area (SANCHA VISION 2030), a typical densely built-up area in Tokyo, has been elaborated including a simulation to estimate benefits from the application of distributed energy systems in terms of reduced energy consumption and CO₂ emissions as well as mitigation of the heat-island phenomenon. As a result, it was demonstrated that a “distributed local energy system”, which provides a district with both electrical power and heat through an integrated distribution system, may contribute to a considerable improvement in energy efficiency for those areas. In addition, it may also provide other benefits, including enhancement of living amenity and urban security in times of emergency.     

Effect of soybean varieties on the content and composition of isoflavone in rice-koji miso

To clarify the effect of soybean varieties on isoflavone, a useful component for human health, in soybean products, we investigated changes in the isoflavone content and composition in rice-koji miso, after fermentation/aging for 6 or 12 months using varieties of soybeans (Tohoku-126, Tohoku-135, Tohoku-139, Suzuyutaka and Chinese soybeans), by high performance liquid chromatography. In soybeans, the total isoflavone content in Tohoku-126 was 444 mg/100 g, which was 1.2–2.0 times the content in the other soybean varieties. The malonyl glycosides and aglycones in soybeans accounted for more than 60% and only a few percent, respectively. As for rice-koji miso, the total isoflavone and aglycone contents were the highest in miso prepared from Tohoku-126. The ratios of glycosides to aglycones (80.1–92.6%) in miso were higher than those in the original soybeans. The time course of the isoflavone composition during the fermentation/aging process of rice-koji miso indicated that glycosides decreased from 86.4% to 44.9% after 6 months but aglycones increased from 9.6% to 53.3%.