自然のプロセスは、数多くの科学的な知見だけでなく、将来人類がより良く（より簡単に、安価に、環境に優しく）振る舞うにはどうしたら良いのか教えてくれる。それゆえに、自然のプロセスの研究は、人類と地球の共生のための技術（技術）を開発するための素晴らしいレッスンということができる。本講演では、技術、特に持続可能な汚染水・土壌浄化や安全な放射性廃棄物の地層処分のために筆者が行ってきたいくつかのレッスンについて紹介する。

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Japan is surrounded by the sea. Recently it has been severely and gradually contaminated by oils, dust, organic matters or radioactive substances which are drained from the human activities. And contaminations or destructions of sands on the sea·shores which is bordered on ocean has been in advanced too.
In this study, the method of estimation, using the Singing or Musical Sands for contaminated sands on the sea-shore which is distributed throughout in Japan, is proposed to estimate the quality of sands.

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120年に亘り、独•米•日が食糧生産の国家プロジェクトに挑戦し、敗退の連続であった。農芸化学•発酵工学的、更には、遺伝子工学的アプローチが殆どで、光バイオ的手法は回避したのだ。光(Solarエネルギー)の替わりに、グルコースや酢酸等の化学エネルギーを大量の酸素で利用する超動物的(Photo-Hetero) BioはCO₂を大発生する内燃機関そのものであった。他方、光のみEnergyとして使うPhoto Autotrophic BIOには、(1)草木の様に成長が遅いTypeと、(2)単位受光面積当り数100-数万倍高効率的な超光合成変換が24時間連続反応出来るTypeとがある。長日植物には、連続光で開花結実可能のC3植物(小麦等)やクロレラ等のマイクロAlgaeがあり、その量子要求は12mol(又は、12Einsteinとも云う)で、その逆数を量子報酬と云う。コメ等の短日植物は、開花結実に、8-12時間『暗期』が必要であり、1molの光量子で、CO₂12分子を同化出来る。量子報酬=1/12mol=0.083molである。海中区画設定Systemを用いれば森林農地喪失等の問題は起きない。海水dsw(深層水)による単1培養、精密設計培地との混合培養も出来るので、Algae組成に沿った成分供給が可能である。当然、海を汚染しない農業と漁業の構築が可能である。カトリーナ被害は15兆円に達し、巨大ハリケーンや台風が益々多発している。20年待たずして地球温暖化による経済損失は1000兆円/年を越えるというのは、英国スターン卿/元世界銀行『副頭取の経済報告』の通り。

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建物や道路からなる都市キャノピーを模擬した加熱粗面上に発達した対流境界層における乱流輸送過程を，ラージエディシミュレーション(LES)により数値的に検討した．粗面なしの理想的な場合との比較を通じて，粗面により温度場と速度場との乱流輸送過程の非相似性が顕著となることを明らかにした．温度場の乱流フラックスは速度場のものと定性的にも一致せず，特に，建物直上において値が急増した．一方，粗面が速度場に与える影響は小さかった．このような乱流フラックスの相違に呼応して，都市キャノピーを含む境界層内に形成される組織構造についても，主流方向に伸長する筋状構造の強度など温度場は速度場と異なる特性を有した．

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世界の海洋には、夏期においても鉄が不足し(0.2ｎＭ以下)、植物プランクトンによる基礎生産が制限され、硝酸などの栄養塩が余っている海域が3海域ある(南極海、赤道湧昇域、亜寒帯太平洋)。微量元素である鉄濃度を調節し、余っている栄養塩を使って、基礎生産を促し、大気中の二酸化炭素を海洋に吸収させる実験が海洋鉄散布実験である。本発表では我が国主導した3つの実験(SEEDS, SERIES, SEEDS II)の概要を紹介するとともに、一連の鉄散布実験以降、国際社会が、鉄散布を含む

的手法がどのように認識され、法的規制へと至ったかを紹介する。

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This paper describes quantitative evaluation of pyrite leaching with Leptospirillum ferrooxidans, an iron-oxidizing chemoautotroph without sulfur-oxidizing ability.
Leaching experiments were carried out in shaking flasks. Massive pyrite was ground and sieved to obtain the size fraction between 20 and 37 micro meters. A pure culture of L. ferrooxidans (ATCC29047) and an enrichment culture of Thiobacillus ferrooxidans were used for inoculum. Several sets of flasks containing inorganic nutrient medium, 1 % of the pyrite and the inoculum were prepared for each experiment. Every two days, one flask of the series was removed from the shaker for analysis. In the case of L. ferrooxidans, the bacterium grew in this condition and solubilized pyrite. Over 90 % of iron were dissolved from pyrite within 400 hours. With the progress of iron extraction, notable amount of sulfur particles was observed in SEM photomicrograph. Those particles attached to residual pyrite, but did not prevent pyrite dissolution. The major products of sulfur species in the pyrite degradation with L. ferrooxidans were elemental sulfur and sulfuric acid. Total amount of these two products corresponded with the amount of degraded sulfur calculated from dissolved iron in every sampling point. The molar fraction of elemental sulfur in total degraded sulfur was approximately 1 / 4 throughout the experiment. In contrast, the major product of sulfur species was sulfuric acid, and no elemental sulfur was detectable in the case of pyrite leaching by T. ferrooxidans.

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This paper describes an inhibition of oxidation and growth of Thiobacillus ferrooxidans by chloride ion and the effect of diatomaceous earth against its inhibition.
Ferrous ion oxidation experiment in the absence of nutrient salts was carried out with various amount of chloride ion. The assay solution of this experiment contained only ferrous sulfate and magnesium sulfate (pH 1.5), and no bacteria grew in this condition. The oxidation of ferrous ion was inhibited by the chloride ion, and was subjected to the competitive inhibition from the Lineweaver-Burg plot. The addition of the diatomaceous earth in assay solution had no effect on the bacterial oxidation.
The growth of T. ferrooxidans in 9 K medium was also inhibited by the chloride ion. The growth kinetics of this bacterium in the presence of chloride ion were described with the modified Monod type equation including the term of inhibitor concentration. The growth inhibition reduced by the addition of diatomaceous earth in the medium. The oxidation rate in the presence of diatomaceous earth was much faster than that in the absence of it in high concentration of chloride ion. The growth inhibition constant of adsorbed bacteria was about 60 % larger than that of free bacteria, which was the reason the oxidation of ferrous ion in the presence of diatomaceous earth was faster.
The adsorption amount of T. ferrooxidans onto the diatomaceous earth was almost constant in this experimental range of the chloride ion.

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循環型社会を構築する上で, 食品廃棄物の飼料化・堆肥化・メタン発酵などを行う再資源化部門は人々の社会経済活動に大きな役割を果たす.したがって, 循環形成の効果を評価する際には再資源化部門以外の部門を含めた広い視野で評価しなければならない.加えて現在は過型から循環型社会への移行の過渡期であり, 循環型社会を構築するにはシステム系外からの影響に柔軟に対応できることや再生品の需給バランスを考慮することが必要条件となる.本研究では産業廃棄物の動植物性残渣と事業系一般廃棄物の厨芥類に注目し, 経済社会内の各部門の需給バランスの取り扱いが容易な応用一般均衡モデルを用いて, 各種対策 (再資源化部門への補助金・廃棄物委託処理価格の値上げ・バージン財への課徴金) や環境制約 (最終処分量と二酸化炭素排出量) が食品廃棄物の循環形成に与える影響について評価を行った.

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No matter what external force is exerted to a stable truss structure, it can be stabilized without causing large displacements. This is the reason why it is called a stable structure. In the case of an unstable truss structure, however, it is not certain to support such forces in the initial configuration. It would probably change its configuration far from its initial state. The purpose of this study is to establish a simple numerical method to seek such an equilibrium stateof the unstable structure which is subject to arbitrary given forces. It will be also shown that each of member forces can be easily derived at the same time if the equilibrium state is obtained.

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Nowadays suspension bridges tend to be long-spanned with the background of the development on wind-resistant engineering. But so many physical problems are still left in the design, and especially, flutter phenomena are the major and serious ones because they are classified into divergent oscillations. Therefore, it is essential to classify flutter instabilities associated to the geometrical shapes of the bridge girders. In this paper, heaving branch coupled flutter for fundamental girders with center barriers is discussed from the point of its generating mechanisms.

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Viscosity changes of hectorite slurry and drilling mud water under hydrothermal condition were observed by using stirring autoclave coupled with torque meter. Semi-quantitative values of viscosity were estimated on the basis of an empirical liner function between share rate and torque of a standard fluid.
Viscosity of the drilling mud water changed slightly in the range from room temperature to 220 °C, suggesting moderate characteristics for high temperature mud water. But its viscosity depleted suddenly above 220 °C, which indicates that two phase separation was occured due to alteration of the mud water. Viscosity of the hectorite slurry increased in the ranging from 120 °C to 180 °C, which corresponds to the crystallization temperature of hectorite. However, its viscosity decreased above 180 °C after crystallization of hectorite. These facts indicate that two phase separation, composing from crystallized hectorite and residual solution, was occurred in the temperature range up to 180°C.
Hectorite slurry is one of possible agents for plugging fractures in geothermal reservoir to prevent lost circulation. The equipment developed here and estimation method of viscosity are applicable to evaluate plugging process of hectorite slurry in a geothermal reservoir.

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Robotic excavation and loading task have been receiving considerable attention in several fields, especially in mining and construction site. In order to realize the robotic excavation by the wheel loader, the robot has to recognize the shape of the rock pile because the excavation task is planned based on the shape of the rock pile. This paper is related to the vision system to recognize the shape of the rock pile. A CCD camera was used to obtain the image of the rock pile. The image processing procedure was proposed to detect the rock pile area from the original image.

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