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61.
Meisen Li Yoshiyuki Bando Ryo Tanigawara Toru Kamiya Keiji Yasuda Masaaki Nakamura 《加拿大化工杂志》2001,79(4):602-607
The effects of operation conditions on the flow behaviour in gas–liquid countercurrent trickle bed biofilter were experimentally examined. In order to prevent gas channelling in the biofilter, packings with a relatively large void fraction, which have a role to maintain a high void fraction in the bed, were added. The gas and liquid velocities of the packed structure and the packings were changed, and the residence time distributions (RTDs) of the gas and liquid were measured. It was found that the addition of void supporters was very effective in the suppression of gas channelling. 相似文献
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Yusuke Yamada Atsushi Ueda Zhen Zhao Toru Maekawa Kengo Suzuki Tadashi Takada Tetsuhiko Kobayashi 《Catalysis Today》2001,67(4):325-387
The rapid evaluation of catalysis is an indispensable technology for the success of combinatorial chemistry. A small-sized, less expensive, easily operating screening is desirable for parallel settings which dramatically shortens the evaluation time. Recent advances in gas sensors have enabled us to use them for the rapid evaluation of oxidation catalysis. Three typical catalytic oxidations over metal oxide catalysts were evaluated by gas sensor systems optimized for each catalytic system. The first one is the total oxidation of carbon monoxide in air. Five catalytic combustion-type gas sensors were used in a parallel reactor system to shorten the evaluation time. The second one is the oxidative dehydrogenation (ODH) of ethane over the mixed oxide of nickel and iron. The evaluation of the ODH catalysis was performed by a selective olefin sensor which determines the concentration of C2H4 in C2H6. The third one is the selective oxidation catalysis of propane over alkali modified Fe/SiO2. The effluents including CO, CO2, aldehydes and ketones in propane were analyzed by the CO, CO2 and semiconductor-type gas sensors selective toward aldehydes and ketones. These evaluation results indicated that gas sensors have a good potential for the rapid evaluation of oxidation catalysts. 相似文献
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Inohara-Ochiai M Hasegawa S Iguchi S Ashikari T Shibano Y Hemmi H Nakayama T Nishino T 《Journal of Bioscience and Bioengineering》2002,93(6):575-583
The monomeric multimetal-binding beta-galactosidase of Saccharopolyspora rectivirgula (srbg), a glycosyl hydrolase family-2 enzyme, has a unique sequence consisting of 192 amino acid residues with no similarity to known proteins. This 192-residue sequence (termed the "iota [iota] sequence") appears to be inserted into a sequence homologous to the active-site domain of the Escherichia coli lacZ enzyme (lacZbg). To assess the effects of the t sequence at specific sites of beta-galactosidase on the catalytic functioning and molecular properties of beta-galactosidase, deletion or insertion mutants of beta-galactosidases were constructed, expressed in LacZ- E. coli strains, and characterized: srbgdelta in which the iota sequence was deleted from srbg, and lacZbgI, in which the 192-residue iota sequence was inserted into the corresponding position (between Asp591 and Phe592) in the active-site domain of lacZbg. srbgdelta was a catalytically inactive, dimeric protein which retained multimetal-binding characteristics, suggesting that the iota sequence is very important for maintaining the structure necessary for the catalytic functioning and the monomeric structure of srbg but is not responsible for the unique metal ion requirements of srbg. On the other hand, lacZbgI existed as a mixture of a monomer, a tetramer, and higher multimers. The monomeric species was inactive, whereas the tetramer and other multimers were catalytically active (V(max )K(m) value, 25% of that of lacZbg) and highly specific for beta-D-galactoside. The tetrameric lacZbgI was activated by Mg2+ and Mn2+ with lowered metal affinities, and the stoichiometry of metal binding was unchanged from that of lacZbg. These results, along with the published stereo structure of lacZbg, suggest that, in lacZbgI, the inserted 192-residue iota peptide could fold independently of the lacZbg domains into a "sub-domain," lying distant from the active site and subunit interfaces. 相似文献
66.
Hemmi H Yamashita S Nakayama T Nishino T 《Journal of Bioscience and Bioengineering》2002,93(5):515-518
It is known that 1-deoxy-D-xylulose taken up by Escherichia coli is used as the precursor of the compounds synthesized via the non-mevalonate pathway, such as isoprenoids, probably after conversion into 1-deoxy-D-xylulose 5-phosphate. In this report, we show that a novel phospho(enol) pyruvate-dependent phosphotransferase system catalyzes the uptake and phosphorylation of 1-deoxy-D-xylulose. 相似文献
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Toru Otawa 《国际能源研究杂志》1980,4(3):283-306
The use of wind energy by means of its conversion to electricity involves a number of constrains such as economic, environmental, technical, legal, social and institutional requirements. Planning for wind energy should solve these issues in the planning process by encouraging opportunities and discouraging constraints associated with the use of wind energy. The opportunities and constraints significant at the regional level (i.e. approximately 10,000 km2) were identified, and a systematic method was developed to select sites for large WECS by incorporating the identified factors. These factors include: wind resource, proximity to load centres, proximity to tie-in points, and exclusive land-use areas. The developed method was applied to the western Massachusetts region, and the first results of the study have been acquired. 相似文献