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141.
Yuichiro Hirota Yuichi Nakano Kazuo Watanabe Yoshiaki Uchida Manabu Miyamoto Yasuyuki Egashira Norikazu Nishiyama 《Catalysis Letters》2012,142(4):464-468
Abstract
Catalytic properties of the 75 nm and 0.8 μm-sized SAPO-34 crystals on acetone-to-olefins (ATO) reaction were compared. The 75 nm-sized crystals (nanocrystals) showed longer catalyst lifetime than 0.8 μm-sized crystals, and products selectivity was similar for the two SAPO-34 catalysts, as is the case in methanol-to-olefins (MTO) and dimethyleter-to-olefins (DTO) reactions. The reaction site of ATO reaction over SAPO-34 was studied using coke-deposited SAPO-34 as catalysts whose pores are deactivated through the DTO reaction. The reason for longer catalyst lifetime of the nanocrystals in the ATO reaction must be a large surface area of the SAPO-34 nanocrystals, unlike in the case of the MTO and DTO reactions. 相似文献142.
Hamada S Seike Y Tanimori S Sakamoto T Kishida M 《Journal of Bioscience and Bioengineering》2011,112(5):518-521
An efficient method for the direct extraction of yeast genomic DNA from agave must was developed. The optimized protocol, which was based on silica-adsorption of DNA on microcolumns, included an enzymatic cell wall degradation step followed by prolonged lysis with hot detergent. The resulting extracts were suitable templates for subsequent qPCR assays that quantified mixed yeast populations in artisan Mexican mezcal fermentations. 相似文献
143.
A lithium superionic conductor 总被引:1,自引:0,他引:1
Kamaya N Homma K Yamakawa Y Hirayama M Kanno R Yonemura M Kamiyama T Kato Y Hama S Kawamoto K Mitsui A 《Nature materials》2011,10(9):682-686
Batteries are a key technology in modern society. They are used to power electric and hybrid electric vehicles and to store wind and solar energy in smart grids. Electrochemical devices with high energy and power densities can currently be powered only by batteries with organic liquid electrolytes. However, such batteries require relatively stringent safety precautions, making large-scale systems very complicated and expensive. The application of solid electrolytes is currently limited because they attain practically useful conductivities (10(-2) S cm(-1)) only at 50-80 °C, which is one order of magnitude lower than those of organic liquid electrolytes. Here, we report a lithium superionic conductor, Li(10)GeP(2)S(12) that has a new three-dimensional framework structure. It exhibits an extremely high lithium ionic conductivity of 12 mS cm(-1) at room temperature. This represents the highest conductivity achieved in a solid electrolyte, exceeding even those of liquid organic electrolytes. This new solid-state battery electrolyte has many advantages in terms of device fabrication (facile shaping, patterning and integration), stability (non-volatile), safety (non-explosive) and excellent electrochemical properties (high conductivity and wide potential window). 相似文献
144.
This paper reports the experimental and theoretical study of the surge occurred in prototyping an ultra micro centrifugal compressor. As the first step, the 10 times size model of an ultra micro centrifugal compressor having the 40 mm outer diameter was designed and manufactured. The detailed experimental investigations for the transient behavior of surge with several different values of B parameter were carried out. The experimental results during the surge were compared with those obtained by the non-linear lumped parameter theory in order to validate the effectiveness of the theoretical surge model for the micro centrifugal compressor. As a result, the quite different behavior of the surge appeared for the different values of B both in the experiment and in the analysis. 相似文献
145.
In order to establish the design methodology of ultra micro centrifugal compressor, which is the most important component of ultra micro gas turbine unit, a 10 times of the final target size model was designed, prototyped and tested. The problems to be solved for downsizing were examined and 2-dimensional impeller was chosen as the first model due to its productivity. The conventional ID prediction method, CFD and the inverse design were attempted. The prototyped compressor was driven by using a turbocharger and the performance characteristics were measured. 相似文献
146.
Yuichiro Wakashima Shin Yamamoto Masao Kikuchi Shinichi Yoda Masato Mikami Akira Umemura 《Microgravity science and technology》2005,16(1-4):338-341
The major goals of the researches in combustion science are to provide predictive and controlling capabilities to enhance combustion technology and fire safety. In other words, the practical motivations for combustion study and application research are, owed to the widespread dependence on combustion processes in modern societies. Furthermore, environmental concerns recently dominate needs of combustion research for the realization of low-emissive, efficient energy generation and utilization. The utilization of microgravity is an exceedingly useful tool for the scientific research for realization of physics and dynamics of combustion phenomena, such as spray combustion. Many experiments have been conducted in order to investigate combustion phenomena without natural convection. Now in addition, numerical simulation becomes useful method for further understanding of combustion phenomena. From the fundamental viewpoints, the interactions among fluid dynamics, scalar transport, thermodynamics and chemical kinetics that are characteristic of combustion phenomena have been investigated by above experimental and numerical methods. This paper reports about our efforts on microgravity combustion study. In order to describe the characteristic mode of droplet-to-droplet flame propagation, we conducted the numerical simulations and dropshaft experiments comparing with theoretical prediction models of flame propagation. 相似文献
147.
Kiyoharu Nakagawa Chiaki Kajita Yuichiro Ide Masato Okamura Shinjiro Kato Hitoshi Kasuya Na‐oki Ikenaga Tetsuhiko Kobayashi Toshimitsu Suzuki 《Catalysis Letters》2000,64(2-4):215-221
Ga2O3 and Ga2O3/TiO2 catalysts were found to be effective agents for the dehydrogenation of ethane to ethene in the presence of carbon dioxide
at 650 °C. The activity of the Ga2O3 and Ga2O3/TiO2 catalysts in the presence of CO2 was 2–4 times higher than that without CO2. Ethene yields reached ca. 20–25% and selectivity was ca. 70–90% at 650°C in the 17% ethane and 83% CO2 feed at an SV of 9,000 ml/(g‐cat h). The presence of CO2 markedly promoted dehydrogenation of ethane over Ga2O3 and Ga2O3/TiO2 catalysts. Furthermore, the promoting effect of CO2 on the aromatization of ethane and ethene over a Ga2O3+H/ZSM‐5 catalyst was also observed above 650 °C. Aromatics yields were higher than those without CO2.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
148.
E Haramoto H Katayama K Oguma H Yamashita A Tajima H Nakajima S Ohgaki 《Water science and technology》2006,54(11-12):301-308
The seasonal profiles of microorganisms in raw sewage, secondary-treated sewage, and final effluent at a wastewater treatment plant in Tokyo, Japan, were quantitatively determined each month for one year, from July 2003 to June 2004. Human noroviruses, which were determined by real-time PCR, in raw sewage varied from 0.17-260 copies/mL for genotype 1 and from 2.4-1900 copies/mL for genotype 2, showing much higher values in winter, the epidemic season. The concentration of total coliforms, Escherichia coli, or F-specific phages in raw sewage was almost constant throughout the year. Human noroviruses of genotype 2 were removed most effectively (3.69 log10 on average) at the wastewater treatment plant, followed by E. coli (3.37 log10), total coliforms (3.05 loglo), F-specific phages (2.81 log10), and human noroviruses of genotype 1 (2.27 log10). The removal ratio of human noroviruses was almost constant, independent of the initial concentration of the viruses in raw sewage, which led to the increasing concentration of human noroviruses in final effluent in winter. None of the tested bacteria was judged to be a reliable indicator of human noroviruses in final effluent. 相似文献
149.
150.
Kohei Ichikawa Yuichiro Shin Toshiyuki Sawa 《International Journal of Adhesion and Adhesives》2008,28(8):464
Stress distributions in stepped-lap adhesive joints subjected to static tensile loadings are analyzed using three-dimensional finite-element calculations. For establishing an optimum design method of the joints, the effects of the adhesive Young's modulus, adhesive thickness and number of steps on the interface stress distributions are examined. The results show that the maximum value of the maximum principal stress σ1 occurs at the edge of the adhesive interfaces. The maximum value of the stress σ1 decreases as the adhesive Young's modulus and number of steps increase and as the adhesive thickness decreases under static loadings. A method for estimating the joint strength under static loadings is proposed using interface stress distributions. For verification of the finite-element method calculations, experiments were carried out to measure the strains and the joint strengths under static loadings. Fairly good agreements were found between the numerical and the experimental results. 相似文献