Shunsuke Nogita

Synthesis of diamond by decomposition of methane in microwave plasma

Dans le plasma, CH 4 est deshydrogene en radicaux CH 3 , CH 2 et CH. Ces radicaux sont adsorbes sur le substrat et se decomposent thermiquement en formant diamant et graphite, la vitesse de formation de ce dernier etant beaucoup plus grande que celle du diamant

Acute toxicant warning system based on a fish movement analysis by use of AI concept

A fish automonitoring system was developed which enables monitoring for the presence of acute toxicants in water, continuously and quantitatively, based on an image recognition and knowledge-based system. A fish image was first recognized online and then its movement pattern was analyzed. Statistical characteristics of the fish-movement pattern in the water tank were applied to evaluate acute-toxicant presence in the water, based on production rules which were gathered in a series of experiments. The knowledge based was simplified through the aid of image analysis of movement patterns, although the visual observations themselves included complicated information.<<ETX>>

Basic studies on carbon dioxide/air control system for activated sludge processes

Abstract Basic facts about the production of carbon dioxide by activated sludge in an aeration tank were gathered with a continuous-flow-type apparatus, and the dynamic characteristics of activated sludge was analyzed with a batch-type aeration tank. In addition, a carbon dioxide/air control system was designed and applied to an activated sludge pilot plant, where the carbon dioxide in exhausted air was continuously measured with an infrared analyzer. The control system maintained the carbon dioxide concentration in exhausted air within ± 0.005 vol%, with a typical diurnal flow rate pattern in sewage, and maintained the oxygen content in mixed liquor within ± 0.4 mg l −1 .

BASIC STUDIES ON AN ORP/EXTERNAL CARBON SOURCE CONTROL SYSTEM FOR THE BIOLOGICAL DENITRIFICATION PROCESS

ABSTRACT A control index for the biological one sludge pre-denitrification process and its application feasibility to a control system were investigated experimentally. ORP (Oxidation Reduction Potential) was found to be an effective index. The denitrificaton rate was improved in experiments, in which the methanol feed rate was controlled according to the ORP values in the mixed liquor contained in the denitrification tank.

Characteristics of air-blown gasification in an entrained-bed coal gasifier.

The characteristics of air-blown coal gasification has been studied in a process development unit of an entrained-bed gasifier. Taiheiyo and Ermelo coals were used in this work. Comparing the experimental results obtained in the two-stage gasification method, it was confirmed that there is an appropriateair distribution ratio in the two-stage method which results in the reduction of the difference in the carbon conversions of Taiheiyo and Ermelo coals. Carbon conversion shows a linear relationship with the ratio of total supplied oxygen to the carbon contents in the coals.The ratio of the experimental value, ηg (cold gas efficiency), to the theoretical value, η*g was introduced as a performance index of the gasifier. On the basis of a slag flow temperature comparison, it was concluded that only a small difference existed in the performance indexes of the air-blown and the oxygen-blown gasifications in this gasifier.