Speciation of selenium in selenium-enriched seeds,buckwheat (<Emphasis Type="Italic">Fagopyrum esculentum</Emphasis> Moench) and quinoa (<Emphasis Type="Italic">Chenopodium quinoa</Emphasis> Willdenow)

Buckwheat (Fagopyrum esculentum Moench) and quinoa (Chenopodium quinoa Willdenow) are widely used as food ingredients. The nutritional characteristics of these plants, i.e., high contents of proteins and amino acids suggest that selenium (Se) is preserved as selenoamino acid derivatives, in particular, selenomethionine (SeMet) in proteins, similar to selenized yeast. Therefore, buckwheat and quinoa are expected to be a good nutritional source of Se. Selenized buckwheat and quinoa were cultivated on Se-fortified soil using sparingly soluble Se salts, such as barium selenate and barium selenite. Se concentration in the edible parts of these plants was determined, and Se extraction efficiency with enzyme or alkali was evaluated. In addition, the chemical species of Se in the low molecular weight fraction of these plants were determined by HPLC-ICP-MS. Total Se concentrations in the edible parts of selenized buckwheat and quinoa were 170.4 ± 2.9 μg/g and 102.7 ± 2.4 μg/g wet weight, respectively. Thus, these selenized seeds were found to be Se accumulators. The results indicate that Se in selenized buckwheat exists mainly as SeMet, while Se in selenized quinoa exists not only as SeMet but also as selenate (Se(VI)) and non-protein forms.     

Optical properties of alumina ceramics as a substrate of thin film solar cells

For full understanding of the optical properties of alumina ceramics which are used as a substrate of thin film c-Si solar cells, we carried out computer simulations of diffuse reflectance and measurements of angle-resolved reflectance. As the result of the computer simulations, we obtained a theoretical expression for the reflectance properties of alumina ceramics with flat surface. The expression can be applied for the measured reflectance of alumina ceramics with rough surface when an effect of surface condition was taken into account.     

Temporal dynamics and drivers of lake ecosystem metabolism using high resolution observations in a shallow,tropical, eutrophic lake (Laguna Lake,Philippines)

The physical, chemical, and biological dynamics under changing atmospheric conditions of Laguna Lake, Philippines were analyzed from intensive observations. Diel measurements were conducted for 48 continuous hours for both dry and wet tropical seasons in addition to fine resolution long-term monitoring. Results revealed significant vertical and diel variations of lake variables in spite of a shallow water depth (2.5 m) caused by the intense surface heating from solar irradiance (~800 W m^?2) and accentuated by the lake's high turbidity (16–32 ftu). Late afternoon land-lake breeze (~5–7 m s^?1) regularly breaks daytime thermal stratification, and convective cooling at night maintains isothermal condition until dawn of the next day. The stratified condition demonstrated a wind-driven, density-induced 2-layer current pattern with a windward moving epilimnion (~4 folds faster) and a compensating hypolimnetic flow in the general lake circulation direction. Laguna Lake was observed to have a dominating diel cycle but also undergoes significant seasonal limnological variations brought primarily by climate, hydrology, and its interaction with the adjacent sea. Significantly correlated variations of pH, chlorophyll-a and DO in the dry season were indicative of the higher biological activity associated with the intrusion of polluted waters from Metro Manila. The non-occurrence of thermal over-turn was observed to be regularly followed by bottom hypoxic conditions (2–4 mg L^?1), indicative of the eutrophic condition of the lake and the importance of diel wind-induced mixing in the bottom supply of DO. Laguna Lake was found to be predominantly net heterotrophic (GPP:R < 1, NEP < 0).     

Determination of captafol,cyhexatin, 1-naphthylacetic acid and quintozene in apple,Japanese pear and melon by simultaneous extraction

A simple and rapid method is described for the determination of the non-registered pesticides, captafol, quintozene (PCNB), cyhexatin and 1-naphthylacetic acid (NAA), in fruits. These pesticides were extracted with acidified acetone, then captafol and PCNB were purified with a Florisil mini column and analyzed by GC-ECD. Cyhexatin was ethylated with ethylmagnesium bromide, and the ethyl derivative was analyzed by GC-FPD (Sn filter). NAA was purified with liquid-liquid extraction and determined by HPLC equipped with a fluorescence detector. These analytes were identified with GC/MS or LC/MS. The minimum identified concentration of the pesticides was below 0.2 ng per injection, which corresponds to a detection limit of below 0.02 microgram/g in the original samples. Recoveries of the pesticides spiked at 0.1 microgram/g into apple, Japanese pear and melon were greater than 61%.     

Volatilization and recovery of mercury from mercury wastewater produced in the course of laboratory work using Acidithiobacillus ferrooxidans SUG 2-2 cells

The iron-oxidizing bacterium Acidithiobacillus ferrooxidans SUG 2-2 is markedly resistant to mercuric chloride and can volatilize mercury (Hg0) from mercuric ion (Hg2+) under acidic conditions. To develop a microbial technique to volatilize and recover mercury from acidic and organic compound-containing mercury wastewater, which is usually produced in the course of everyday laboratory work in Okayama University, the effects of organic and inorganic chemicals on the mercury volatilization activity of A. ferrooxidans cells were studied. Among 55 chemicals tested, the mercury volatilization from a reaction mixture (pH 2.5) containing resting cells of SUG 2-2 (1 mg of protein) and mercury chloride (14 nmol) was strongly inhibited by AgNO3 (0.05 mM), K2CrO7 (1.0 mM), cysteine (1.0 mM), trichloroethylene (1 microM), and commercially produced detergents (0.05%). However, the strong inhibition by trichloroethylene and detergents was not observed when these organic compounds were chemically decomposed using Fenton's method before the treatment of the wastewater with SUG 2-2 cells. When 20 ml of water acidified with sulfuric acid (pH 2.5) containing ferrous sulfate (3%), diluted mercury wastewater (17.5 nmol of Hg2+) and SUG 2-2 cells (0.05 mg of protein) were incubated for 10 d at 30 degrees C, 47% of the total mercury in the wastewater was volatilized and recovered into a trapping reagent for metal mercury. However, when the organic compounds in the mercury wastewater were decomposed using Fenton's method and then treated with A. ferrooxidans cells, approximately 100% of the total mercury in the wastewater was volatilized and recovered.     

Application of microbial genes to recalcitrant biomass utilization and environmental conservation

Recent papers concerning the application of microbial genes to recalcitrant biomass utilization and environmental conservation are reviewed. Microbial genes have been integrated and expressed in plants and microorganisms. When cellulose-degrading enzyme genes are expressed in rice plants, the transgenic plants exhibit swollen cell walls which increases the digestibility of rice straw in the rumen. When genes encoding aromatic compound-degrading enzymes are expressed in plants, it is expected that aromatic compounds contaminating soil would be degraded during the growth of the transgenic plants. The former transgenic plants are utilized as feed and the latter for phytoremediation. Dockerin and cohesin interactions occurring in the cellulase complex, cellulosome, are applied to the construction of artificial enzyme complexes and protein purification by expressing the genes in transformed bacteria and/or silkworms, respectively. In the case of the forced expression of bacterial genes encoding chitinase and/or hydrogenase in the wild-type bacteria, chitin degradation and hydrogen gas production in the transformed bacteria occur at much higher rates than in the wild type.     

Application of nuclear energy for environmentally friendly hydrogen generation

It is universally admitted that hydrogen is one of the best energy media and its demand will increase greatly in the near future. However, little hydrogen exists naturally, so that how to generate hydrogen without bringing forth much CO₂${}_2$ will be very important research subject. Hydrogen generation from water using nuclear energy is one of the solutions for this problem. Especially, the high temperature gas cooled reactor (HTGR) has a possibility to generate hydrogen economically compared with other types of nuclear reactors. As for long-lived radioactive waste to be generated by nuclear reactors, it is expected to significantly reduce its burden to the human environment by applying transmutation technologies. This report describes the feature of the hydrogen generation with HTGR and the development of the accelerator-driven subcritical system to reduce radioactive waste ongoing at JAEA.     

Applying heat integration total site based pinch technology to a large industrial area in Japan to further improve performance of highly efficient process plants

“Area-wide pinch technology” which consists of R-curve analysis and Site Source Sink Profile (SSSP) analysis, was applied to Kashima industrial area, one of the biggest heavy chemical complexes in Japan. This case study demonstrates that despite the very high efficiency of the individual sites in the complex, there is a huge amount of energy saving potential through energy sharing among the various sites. In addition it was found that appropriate use of the available pinch technology tools and techniques allows an industrial area of enormous scale and complexity to be analysed conveniently. This has resulted in practical area-wide energy saving projects being proposed and implemented.     

Numerical simulation of an arbitrarily ended asymmetrical slab waveguide by guided-mode extracted integral equations

The scattering phenomenon from an arbitrary-shaped end of a asymmetrical slab waveguide for the cases of TE and TM guided modes is simulated by means of boundary integral equations that are called guided-mode extracted integral equations. The integral equations that we derive can be solved by the conventional boundary-element method. Numerical results are presented for problems of three-layer asymmetrical waveguides with tilted ends. The reflection coefficient, reflected and scattered powers, and radiation patterns are calculated numerically for the cases of incident TE and TM guided modes.