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511.
Performance of droplet generator and droplet collector in liquid droplet radiator under microgravity
T. Totani M. Itami H. Nagata I. Kudo A. Iwasaki S. Hosokawa 《Microgravity science and technology》2001,13(2):42-45
The Liquid Droplet Radiator (LDR) has an advantage over comparable conventional radiators in terms of the rejected heat power-weight
ratio. Therefore, the LDR has attracted attention as an advanced radiator for high-power space systems that will be prerequisite
for large space structures. The performance of the LDR under microgravity condition has been studied from the viewpoint of
operational space use of the LDR in the future. In this study, the performances of a droplet generator and a droplet collector
in the LDR are investigated using drop shafts in Japan: MGLAB and JAMIC. As a result, it is considered that (1) the droplet
generator can produce uniform droplet streams in the droplet diameter range from 200 to 280 [μm] and the spacing range from
400 to 950 [μm] under microgravity condition, (2) the droplet collector with the incidence angle of 35 degrees can prevent
a uniform droplet stream, in which droplet diameter is 250 [μm] and the velocity is 16 [m/s], from splashing under microgravity
condition, whereas splashes may occur at the surface of the droplet collector in the event that a nonuniform droplet stream
collides against it. 相似文献
512.
NaTaO3 with 4.0 eV band gap showed a high activity for the decomposition of pure water into H2 and O2 without co-catalysts when it was prepared in the presence of excess Na in order to prevent the formation of defects by the
volatilization of Na. When NiO was supported on the NaTaO3 powder, the activity was drastically increased. The quantum yield of the NiO(0.05 wt%)/NaTaO3 photocatalyst was 28% for the water splitting at 270 nm.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
513.
Ag- and Cu-supported TiO2 photocatalysts showed high activity for the reduction of N2O to N2 at room temperature in the presence of CH3OH and H2O vapor. The suppression by H2O on the activity was not observed in the present photocatalyst system. The remarkable behavior of the Ag and Cu co-catalysts
for TiO2 photocatalysts agreed well with that of electro- and thermal catalyses.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
514.
The composite materials containing metal Ni powder of 5–15 μm in size were prepared by use of the matrix epoxy resin of glycidyl amine crosslinked with bis-4-amino-3-methylcyclohexyl methane and 2,4-diamine 3,5-dimethyltoluene. Dynamic viscoelastic properties of the composites at various volume fraction (Φp) of Ni powder have been measured over the temperature range from 30 to 300°C. The peak temperatures in dynamic loss modulus–temperature diagrams of the composite increased with increasing Φp, although the peak position was abruptly shifted to lower temperatures in the range of Φp more than 0.245. At this high concentration of Φp, agglomeration of the particles occurring in the composite lead to reduction of the interaction between Ni particle and epoxy resin. Parallel studies on the thermal conductivity (λ) of the composites materials showed that the value of λ at Φp = 0.245 increased by approximately 7 times that of the original epoxy resin. The shape of Ni particles also affected the thermal durabilities of the composites; the rough surface of Ni powder yields a higher storage modulus of the composite than that of the materials containing the powder with a smooth surface, which had been brought through a ball-milling process. The finding suggested that the increasing in specific surface area of the powder improved the thermal durability of the composites as well as their mechanical properties. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2593–2598, 1998 相似文献
515.
Daichi Yazaki Tokuhisa Kawawaki Daisuke Hirayama Masanobu Kawachi Kosaku Kato Sota Oguchi Yuichi Yamaguchi Soichi Kikkawa Yoshiya Ueki Sakiat Hossain D. J. Osborn Fumihiko Ozaki Shunsuke Tanaka Jun Yoshinobu Gregory F. Metha Seiji Yamazoe Akihiko Kudo Akira Yamakata Yuichi Negishi 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(34):2208287
For the realization of a next-generation energy society, further improvement in the activity of water-splitting photocatalysts is essential. Platinum (Pt) is predicted to be the most effective cocatalyst for hydrogen evolution from water. However, when the number of active sites is increased by decreasing the particle size, the Pt cocatalyst is easily oxidized and thereby loses its activity. In this study, a method to load ultrafine, monodisperse, metallic Pt nanoclusters (NCs) on graphitic carbon nitride is developed, which is a promising visible-light-driven photocatalyst. In this photocatalyst, a part of the surface of the Pt NCs is protected by sulfur atoms, preventing oxidation. Consequently, the hydrogen-evolution activity per loading weight of Pt cocatalyst is significantly improved, 53 times, compared with that of a Pt-cocatalyst loaded photocatalyst by the conventional method. The developed method is also effective to enhance the overall water-splitting activity of other advanced photocatalysts such as SrTiO3 and BaLa4Ti4O15. 相似文献
516.
Kudo Taciana Novo Bulcão-Neto Renato de Freitas Neto Valdemar Vicente Graciano Vincenzi Auri Marcelo Rizzo 《Requirements Engineering》2023,28(1):97-115
Requirements Engineering - Poorly executed requirements engineering activities profoundly affect the deliverables’ quality and project’s budget and schedule. High-quality requirements... 相似文献
517.
Prof. Dr. Fumitaka Kudo Kosuke Kishikawa Kazuma Tsuboi Takafusa Kido Prof. Dr. Takeo Usui Dr. Junko Hashimoto Prof. Dr. Kazuo Shin-ya Prof. Dr. Akimasa Miyanaga Prof. Dr. Tadashi Eguchi 《Chembiochem : a European journal of chemical biology》2023,24(6):e202200670
Streptomyces graminofaciens A-8890 produces two macrolide antibiotics, FD-891 and virustomycin A, both of which show significant biological activity. In this study, we identified the virustomycin A biosynthetic gene cluster, which encodes type I polyketide synthases (PKSs), ethylmalonyl-CoA biosynthetic enzymes, methoxymalony-acyl carrier protein biosynthetic enzymes, and post-PKS modification enzymes. Next, we demonstrated that the acyltransferase domain can be exchanged between the Vsm PKSs and the PKSs involved in FD-891 biosynthesis (Gfs PKSs), without any supply problems of the unique extender units. We exchanged the malonyltransferase domain in the loading module of Gfs PKS with the ethylmalonyltransferase domain and the methoxymalonyltransferase domain of Vsm PKSs. Consequently, the expected two-carbon-elongated analog 26-ethyl-FD-891 was successfully produced with a titer comparable to FD-891 production by the wild type; however, exchange with the methoxymalonyltransferase domain did not produce any FD-891 analogs. Furthermore, 26-ethyl-FD-891 showed potent cytotoxic activity against HeLa cells, like natural FD-891. 相似文献