Each selenium distribution in the midgut gland, as one of the inedible tissues and whole muscle of the several species of bivalves and snails, was investigated in order to clarify the possibility of the available utilization of selenium from the inedible tissues of shellfish, in relation with mercury distribution involved in those tissues. Both levels in the midgut gland in all subjected shellfish was significantly high as that involving the whole muscle and low oxidation states of selenium species existed dominantly in both tissues. On the other hand, the Se/Hg (the molar ratio of selenium to mercury) in the midgut gland of those shellfish as an indicator of the safety of marine products was about the same or higher compared with that involving whole muscle, suggesting that the midgut gland is usually inedible but a significantly safe tissue. However, because the heavy metals such as mercury will tend to accumulate higher in the midgut gland compared with the whole muscle, as a result, the decrease of the molar fraction of bioavailable species of Se(VI) was observed in the midgut gland. These findings suggested that the available utilization of selenium will not be expected from the midgut gland of shellfish, as was not the case of several species of fish previously reported.

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[in Japanese]

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Recently, diversification of eating habits has been advancing in Japan. In such a situation, issues have been raised on the eating habits of younger generation, especially university students. The purpose of our study is to provide dietary life assistance to the university students by developing a system to locate students with unbalanced diet. Meal purchase patterns of university students are analyzed by utilizing purchasing history of the meal prepaid card users. The data are provided by a university co-operative association who runs university cafeterias. The number of the users analyzed are 2,458 (male 1,591 and female 867). The procedure of the analysis is as follows: k-means clustering is applied to the combination of food to generate 22 food clusters. Next PLSA is applied for clustering the customers to generate 8 customer clusters. For these two clusters, Bayesian network is applied to visualize correlation among factors. Based on this visualization and extraction of characteristics through clustering, customer clusters with eating habit problems are detected. Specific proposals for dietary life improvement are proposed to these clusters.

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The recovery system of a degraded lead-acid battery was developed using an on-off constant current charge and short-large discharge pulse. The multifunctional system was equipped with the recovery of a degraded battery, constant current charge or constant voltage charge, and constant discharge current. The system performed monitoring voltage and current in operation, change of control program, remote operation with personal computer connected by a serial cable. A degradation lead acid battery of electricity storage systems will allow recovery without human operation at the installation location. The system recovered a commuting car battery to the same condition as new. The used engine start battery for recovery is suitable for under 5 years from manufacturing time without over discharge, and used deep cycle battery for recovery is recommended for under 8 years from manufacturing time.

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[in Japanese]

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There are various types of cosmetic emulsion. Emulsion is defined as a liquid dispersed in an immiscible liquid (such as water and oil). In this study, we focused on D phase emulsification method, which is categorized into a low-energy emulsification. In the D phase emulsification method, synthetic surfactants have been widely used because of its high emulsification capacity. However, natural surfactant tends to be preferred because cosmetics is directly applied to skin. The primary purpose of this study was to examine whether sodium surfactin, a natural surfactant, was feasible for preparation of emulsion using D phase emulsification method. Moreover, we attempted to improve stability of the emulsion by coating the droplets with hydrogel membrane. We showed that application of sodium surfactin for D phase emulsification resulted in successful preparation of emulsion with fine oil droplets in aqueous phase. We further attempted to coat the oil droplets with (i) sodium alginate membrane, (ii) propylene glycol alginate/chitosan complex membrane or (iii) propylene glycol alginate/glycol chitosan complex membrane. The droplets could be coated with membrane (ii) and (iii). Stability of emulsion of membrane (iii) was higher than that of membrane (ii).

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Organic-inorganic nanocomposites are able to combine desirable characteristics from both organic and inorganic components. Nanocomposites incorporating the properties of inorganic nanoparticles are widely used. However inorganic nanoparticles have a low affinity with an organic monomer. Therefore, agglomeration occurs in the organic polymer, so dispersion is difficult. As a solution to this problem, we focused on the surface modification of inorganic nanoparticles using a silane coupling agent. In this study titanium oxide (TiO2) was chosen as the inorganic nanoparticles. Also, vinyltriethoxysilane (VTES) was selected as a silane coupling agent, ethyl methacrylate (EMA) and methacrylic acid (MA) were selected as monomers. Then, particles were prepared and their characteristics were evaluated. From the characteristic evaluation results, it was found that the surface of TiO2 nanoparticle could be polymerized with the organic monomer, and its coating rate was 9.2%. Further, coating with an organic monomer, we succeeded in reducing the average particle size by coating with an organic monomer.

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[in Japanese]

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Casting hagama is a cooking tool that has inherited the spirit of Zen and tea ceremony since 800 years, continuing to cook rice which is indispensable to Japanese food culture tastily. Therefore, we challenged to develop the hagama made from cast iron. We have succeeded in casting cast iron hagama and furnaces. Their minimum wall thickness of 3 mm. These were realized by combining Cupola melt with a shell mold using newly developed low odor and low defective sand. This hagama can cook a cup of rice with a piece of solid fuel. We hope that this hagama will become a new carrier of the Japanese traditional food culture.

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This paper examined temporal changes in pay-for-performance systems in present-day Japan. From the 1990s, pay-for-performance systems - which evaluate employees and determine their wages and positions based on individual, short-term and explicit performance and achievement - have been adopted in companies in Japan. However, it remained unclear how such systems have been adopted in recent years, what factors moderated their implementation (e.g., employee rank and company size) and whether changes in the sub-systems constituting pay-for-performance systems have followed different patterns. To objectively capture the historical background and current situation of Japanese companies, and to understand how changes in management/economic systems and psychology/behavior in Japan have mutually influenced, temporal changes in pay-for-performance systems should be investigated in more detail. Therefore, this research analyzed data from two large-scale surveys conducted continuously between 1991 and 2016. Results showed that the rate of companies using seniority systems (which determine employee wages and positions based on age and length of service) decreased between 1996 and 2016. Moreover, both the rate of companies using annual salary systems (which determine employee salary based on individual performance every year) and the rate of employees influenced by them increased between 1991 and 2014. These temporal changes were consistent across employee rank (both management and non-management levels) and company size. Thus, pay-for-performance systems have been adopted in more companies and have increasingly affected employees in Japan over the past 30 years. Additionally, this extent of the trend increased with company size: the larger the company, the larger the rates of decrease in seniority systems and of increase in annual salary systems. Furthermore, the increase in annual salary systems was larger at the management level than at the non-management level. On the one hand, seniority systems continued to decrease linearly from the 1990s to the 2010s. On the other hand, annual salary systems continued to increase linearly from 1990 to around 2005, but after around 2005 they did not increase clearly.

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