Study on Genesis of Skarns and the Related Minerals

The present study is concerned with the so-called skarns designated after the rule applied to generally and the related minerals comprised in several ore deposits distributing in the Chūgoku District with respect to their geneses and in pursuit of so-called pyrometasomatic or contact effects. Inspection of the paragenetic relationships among, and identification of, the respective minerals have been fulfilled as elaborately as possible by means of an ordinary microscope and x-ray diffractometer in conjunction with heat treatments especially for some specimens, resulting in more precise interpretation other than various concepts given previously by many authors and furthermore in discovery of some rare minerals taking an important part in the subject under consideration

Possible Excitonic Phase of Graphite in the Quantum Limit State

The in-plane resistivity, Hall resistivity and magnetization of graphite were investigated in pulsed magnetic fields applied along the \textit{c}-axis. The Hall resistivity approaches zero at around 53 T where the in-plane and out-of-plane resistivities steeply decrease. The differential magnetization also shows an anomaly at around this field with a similar amplitude compared to that of de Haas-van Alphen oscillations at lower fields. This transition field appears insensitive to disorder, but reduces with doping holes. These results suggest the realization of the quantum limit states above 53 T. As a plausible explanation for the observed gapped out-of-plane conduction above 53 T, the emergence of the excitonic BCS-like state in graphite is proposed.Comment: 15 pages, 6 figures, to be published in J. Phys. Soc. Jp

On Prehnite and Some Others from the Takase Mine, Okayama Prefecture

The vein-like lenticular mass composed of prehnite and some others have been found intervening within serpentinite in the Takase mine famous for production of the chromite ores on an industrial scale and studied somewhat genetically with respect to so-called "rodingite". In addition, thermal behaviors of prehnite and garnet have been pursued for inspection of their genesis or interrelations.今村外治教授退官記念特集

Enzymatic synthesis of cyclic imino acids

Optically active cyclic imino acids are widely used as important pharmaceutical intermediates and it is necessary to develop cost effective synthetic method for their production. We have already established one-pot synthesis of L-cyclic imino acids from diamino acids by using N-methyl-L-amino acid dehydrogenase (NMAADH) from Pseudomonas putida. In order to make this process more efficient, we established a recombinant Escherichia coli which expresses NMAADH, lysine racemase from P. putida and D-lysine dehydrogenase from Selenomonas ruminantium in a single cell. The recombinant E. coli makes it possible to recycle NADPH by combination of reductive reaction using NMAADH and oxidative reaction using D-lysine dehydrogenase (Fig.1). Please click Additional Files below to see the full abstract

Concentrations of organic acids in automobile and incinerator exhaust gases and their emission rates into the atmosphere

大気中有機酸の発生源である自動車および焼却炉排ガスについて，有機酸（ギ酸，酢酸，プロピオン酸，シュウ酸）濃度を測定した。ガソリン車の排ガス中有機酸濃度の相加平均値は，ギ酸59.7ppbv，酢酸327ppbv，プロピオン酸12.1ppbv，シュウ酸0.77ppbv（parts per billion by volume）であった。ディーゼル車および二輪車は，ガソリン車よりも有機酸濃度がやや高く，特に二輪車の酢酸は10ppmv（parts per million by volume）以上と高かった。広島大学東広島キャンパス設置の焼却炉排ガス中有機酸の組成および濃度は，ガソリン車と同様だった。自動車有機酸の組成及び濃度は，排気量，走行距離とは特に相関が見られず，これらは主に燃料組成，エンジン機構および排ガス浄化装置により決定すると考えられた。排ガス中有機酸の濃度比を，東広島における降水，露，大気中有機酸のそれと比較すると，降水よりも露および大気中有機酸の濃度比に近いことが示された。測定結果から，日本国内の自動車起源の有機酸年間発生量は，ギ酸3.0×109g yr-1，酢酸5.3×109g yr-1，プロピオン酸4.6×108g yr-1，シュウ酸7.9×107g yr-1と見積もられた。さらに一酸化炭素を指標として大気中有機酸への自動車起源有機酸の寄与を計算すると，ギ酸41％，酢酸18％となった。The concentrations of organic acids (formic, acetic, propionic and oxalic acids) were measured in automobile and incinerator exhaust gases, which are one of major sources of atmospheric organic acids. The mean concentrations of formic, acetic, propionic and oxalic acids in the exhaust gases of gasoline-powered vehicles (seven automobile models) were 59.7, 327, 12.1 and 0.77ppbv (parts per billion by volume), respectively. The organic acid concentrations in exhaust gases from one diesel-powered automobile model and two motorcycle models were higher than those from the gasoline-powered vehicles. The acetic acid concentrations in the exhaust gases from the motorcycles were particularly high at >10ppmv (parts per million by volume). The type of fuel, engine, and purification system of the exhaust gas probably determine the concentrations of organic acids in the exhaust gas. The concentrations of organic acids in exhaust gas from an incinerator at the Higashi-Hiroshima campus of Hiroshima University (Japan) were similar to those in the exhaust gas from gasoline-powered vehicles. The concentration ratios of formic, acetic and oxalic acids in automobile exhaust gas were compared with those of atmospheric organic acids, precipitation, and dew. The organic acid concentration ratios in automobile exhaust gas were more similar to those in dew and the atmosphere than those in precipitation. Based on the organic acid concentrations in the automobile exhaust gases, the annual emission rates from all automobiles in Japan were estimated to 3.0×109, 5.3×109, 4.6×108 and 7.9×107g yr-1 for formic, acetic, propionic and oxalic acids, respectively, The percentage contributions of formic and acetic acids from automobile exhaust gas to the acid concentrations in the atmosphere were estimated to 41% and 18%, respectively, using carbon monoxide as an indicator of automobile exhaust gas.本研究は，科学技術振興事業団（JST，現科学技術振興機構），戦略的基礎研究推進事業（CREST），環境低負荷型の社会システムより支援を受けて行われた。また文部科学省科学研究費補助金（研究課題番号14380244）および日産科学振興財団からも助成を受けたものである