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Publication costs assisted by the Ministry of Education Temperature dependence of the concentration fluctuations, {( )2), was observed for binary mixtures of ferf-butyl alcohol (TBA)-water and dioxane-water at various concentrations by the use of light-scattering spectra.In TBA-water mixtures the rapid increase of {( )2) values due to the temperature increase in the range of 17.5-63 °C was observed for xTBA > 0.05, where xTBA is the mole fraction of TBA. This result is reasonably interpreted by considering the breakdown of the clathrate hydrate-like structure and the growth of the water part of the local structure which is composed of water and TBA molecules. In contrast to the result observed for TBA-water mixtures, the {{ )2) values observed for dioxane-water mixtures are small and hardly change magnitude in the temperature range 18-49.5 °C. The analysis of this result suggests that the clathrate hydrate-like structure does not exist in dioxane-water mixtures.

A field survey of 71 salesmen (22-60 years) in a machinery manufacturing company was conducted to investigate the effect of working hours on biological functions related to the cardiovascular system. The subjects were divided into four groups by age, and those in each age group were further divided into shorter (SWH) and longer (LWH) working hour subgroups by weekly working hours. Rates of complaints of subjective fatigue for LWH were significantly higher than those for SWH on the whole. Although the mean amplitude of respiratory sinus arrhythmia at rest decreased with age, no significant difference between SWH and LWH was found in this function. Systolic blood pressure for LWH was significantly higher than that for SWH in the 50-60 year group. The serum total cholesterol level for LWH was significantly lower than that for SWH in the 40-49 year group. Comparison of biological functions related to cardiovascular system was also made between fatigue complaint and no-complaint subgroups. Significant differences were found between the two subgroups: systolic blood pressure was higher and the total cholesterol level was lower in the fatigue complaint subgroups. Summarizing our results, it appeared that long working hours might increase systolic blood pressure and lower the total cholesterol level due to fatigue.

Light-scattering spectra were observed for binary mixtures of iert-butyl alcohol and water at various concentrations. The Rayleigh intensities were reduced to concentration fluctuations. The observed concentration dependencies of the concentration fluctuation were well explained if we consider the existence of the clathrate hydrates in binary mixtures. The structures of the clathrates were (H20)21-TBA for xTBA < 1/22, and( 2 )105•( ) for zTBA 2: 1/22, where xTBA is the mole fraction of TBA.

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