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81.
Y. Ishikawa 《Journal of the American Oil Chemists' Society》1982,59(12):505-510
The effects of various amino compounds trimethylamine oxide (TMAO), tri-n-octylamine (TOA), phosphatidyl choline (PC), and phosphatidyl ethanolamine (PE) on the oxidative decomposition of γ-tocopherol
(γ-Toc) and on the formation of its reducing dimers were investigated during the autoxidation of methyl linoleate (ML). In
general, γ-Toc diphenyl ether dimer (γ-TED) was formed in preference to two atropisomers of γ-Toc biphenyl dimers [γ-TBD(H)
and (L)] in autoxidizing ML. This relationship, however, was reversed when TMAO was added. As the presence of TOA, PC, or
PE did not promote the formation of γ-TBD, the preferential formation of γ-TBD was believed to be based on the interaction
between TMAO and oxidation products formed from γ-Toc. Effects of TMAO and TOA on the interconversion of γ-Toc reducing dimers
were investigated. γ-TED was found to be converted into γ-Toc and γ-TBD(L) in autoxidizing ML. But γ-TBD(H) could not be detected,
and the amount of γ-TBD(L) formed was very small. γ-TBD(H) and (L) were formed from their respective atropisomers. In this
case, the formations of γ-Toc and γ-TED could not be detected. Therefore, it was concluded that the conversion of γ-TED into
γ-TBD and vice versa can be neglected in any event. 相似文献
82.
Utilization of sludge in building material. 总被引:2,自引:0,他引:2
Several thermal solidification processes have been developed mainly in Japan. They are lightweight aggregates, brick, interlocking tile, char, and slag. A full-scale plant of them has been successfully operated for more than 10 years. The quality of the end products is better than the traditional ones. They are all substitutive to existing ones. The Japanese experience proves that all the processes are technically feasible, but not economically. Their manufacturing cost is always higher than market price. In addition, they consume large amounts of energy. However, if they are identified for a process of sludge disposal, all of them are worth considering for a big city where there is no place for the sludge to go. The end products can be reused inside the city. A new alternative is "Portland cement". A Portland cement manufacturer accepts sewage sludge, if being paid some amount of money. An average payment is US$100 each 1,000 kg of ash or sludge cake. The Portland cement manufacturer accepts either cake or ash at the same price. It is about 50 to 30% of the energy cost of thermal solidification. The question is which is the better, dewatered cake or incinerated ash, for the Portland cement application. The answer is "it depends on the distance between the sewage plant and the Portland cement plant." 相似文献
83.
Microdosimetry of neutron field for boron neutron capture therapy at Kyoto university reactor 总被引:1,自引:0,他引:1
Endo S Onizuka Y Ishikawa M Takada M Sakurai Y Kobayashi T Tanaka K Hoshi M Shizuma K 《Radiation protection dosimetry》2004,110(1-4):641-644
Microdosimetric single event spectrum in a human body simulated by an acrylic phantom has been measured for the clinical BNCT field at the Kyoto University Reactor (KUR). The recoil particles resulting from the initial reaction and subsequent interactions, namely protons, electrons, alpha particles and carbon nuclei are identified in the microdosimetric spectrum. The relative contributions to the neutron dose from proton, alpha particles and carbon are estimated to be about 0.9, 0.07 and 0.3, respectively, four depths between 5 and 41 mm. We estimate that the dose averaged lineal energy, yD decreased with depth from 64 to 46 keV microm(-1). Relative biological effectiveness (RBE) of this neutron field using a response function for the microdosimetric spectrum was estimated to decrease from 3.6 to 2.9 with increasing depth. 相似文献
84.
85.
Awane T Kimura T Nishida K Ishikawa N Tanuma S Nakamura M 《Analytical chemistry》2003,75(15):3831-3836
Grazing exit electron probe microanalysis (GE-EPMA) is a new method of EPMA in which characteristic X-rays emitted from only near-surface regions of a specimen are detected at extremely low exit angles near 0 degrees (the grazing exit condition). This technique requires the analytical objects exist on a flat surface. Therefore, the GE-EPMA analysis has been used only for the analysis of particles or a thin film on a flat substrate so that there were only few applications for practical analysis. As a new application, we have carried out GE-EPMA analysis of approximately 0.2-microm inclusions on stainless steel, which appeared to be a projection on the specimen surface with chemical etching. The GE-EPMA quantitative results were in excellent agreement with those of inclusions that were extracted from the stainless steel and analyzed by EPMA with conventional exit condition (30 degrees). This method could be, therefore, applied to the analysis of the submicrometer inclusion in a wide variety of metallic materials if the inclusion appears to be a projection with chemical etching treatment. 相似文献
86.
A droplet spotter for on-demand generation of pico- to femtoliter droplets was developed to meet the requirement for high-density spotting of chemicals on a surface. Our droplet spotter involves applying a approximately 1000-V and approximately 10-ms pulse voltage to the tip of a capillary tube (o.d. approximately 18 microns; i.d. approximately 11 microns) supplied with water or a dye solution. The capability of the spotter was demonstrated by preparing a microarray of dye molecules. The microarray was prepared by spotting approximately 30-fL droplets of a dye solution on a surface at the density of one spot per 20 x 20 micron 2. 相似文献
87.
Mechanical and thermophysical characteristics of Si-Ti-C-O fibre-bonded ceramic produced by hot-pressing the laminated material of oxidized satin-woven Si-Ti-C-O fibre have been investigated at room and cryogenic temperatures. The fibre element (diameter: 8 m, fibre volume fraction: 85 ± 1%) constructing the Si-Ti-C-O fibre-bonded ceramic showed a close-packed structure of the oxidized Si-Ti-C-O fibre mainly composed of fine SiC crystals, amorphous SiO2-based phase and turbostratic carbon. The Si-Ti-C-O fibre-bonded ceramic with lightweight (density: 2.45 × 103kg/m3) and low porosity (<1 vol%) showed a markedly higher fracture energy (notched, cross-plied specimen: approximately 10kJ/m2) and lower thermal conductivity (1/10 the value of stainless steel). The reason why the fibre- bonded ceramic showed such a low thermal conductivity in spite of very high thermal conductivity of a pure SiC and carbon could be attributed to the complicated microstructure of Si-Ti-C-O fibre-bonded ceramics. 相似文献
88.
Ito T Kikuta H Nagamori E Honda H Ogino H Ishikawa H Kobayashi T 《Journal of Bioscience and Bioengineering》2001,91(3):245-250
Efficient lipase production by two-step fed-batch culture of an organic solvent-tolerant bacterium, Pseudomonas aeruginosa LST-03, was investigated. When FB synthetic medium was used in flask culture, no lipase activity was detected, whereas lipase was produced at 2.3 I.U./ml in C2 complex medium. However, lipase production was induced in FB medium when a fatty acid was added to the culture broth in the stationary phase. Among fatty acids tested, long chain saturated fatty acids, such as C18 (stearic acid) and C20 (arachidic acid), were found to function as effective inducers for the production of lipase, giving an activity level almost the same as that obtained in C2 medium in flask culture. Two-step lipase production, comprised of a growth phase in fed-batch mode and a production phase in which lipase was induced by the addition of 5% (v/v) stearic acid, was carried out in a jar-fermentor. In the growth phase, the maximum cell concentration at 16 h was only 20 in terms of the optical density at 660 nm (OD660), and a low level of lipase production (8 I.U./ml) was obtained after 167 h. This was considered to be due to the exhaustion of several medium components brought about by the use of an unsuitable medium or feeding solution. After analyzing the contents of the compounds in the culture broth by inductively coupled plasma spectrometry for metal ions and HPLC for anions, a modified FB medium was designed. When this modified FB medium was used in two-step fed-batch culture, the maximum cell concentration reached an OD660 of 55 (30.2 g-dry cells/l) at 16.5 h, and lipase was produced at 96 I.U./ml after 35 h, which is approximately 40 times higher than the production level obtained in flask culture using C2 medium. 相似文献
89.
T. Ogasawara T. Ishikawa N. Suzuki I. J. Davies M. Suzuki J. Gotoh T. Hirokawa 《Journal of Materials Science》2000,35(4):785-793
The present work investigates the tensile creep behavior (deformation and rupture) at 1100–1300°C in air of a 3-D woven Si-Ti-C-O (Tyranno) fiber/SiC-based matrix composite with and without glass sealant. The composite contained Si-Ti-C-O fibers with an additional surface modification in order to improve interface properties. Although a significant decrease in tensile strength was observed in the unsealed composite beyond 1000°C in air (and attributed to oxidation of the fiber/matrix interface), the composite with glass sealant possessed excellent mechanical properties for short-term (<1 hr.) exposure in air. In this study, tensile creep testing was conducted at 1100–1300°C in air and the effect of glass sealant on medium- and long-term strength was investigated. In addition, chemical stability of the glass sealant was evaluated by X-ray diffraction analysis (XRD) and energy dispersive X-ray spectrometer (EDS). The creep rupture behavior of the composite with glass sealant under long-term exposure is suggested to depend on several factors including decomposition, evaporation, and crystallization of the glass sealant material, in addition to the applied stress. 相似文献
90.
N. Hashimoto A. Handa M. Nakagawa K. Obara H. Yano O. Ishikawa T. Hata 《Journal of Low Temperature Physics》2007,148(3-4):299-303
We have investigated the turbulence transition of the superfluid 4He flow generated by a vibrating wire. For a 1.2-kHz vibrating wire, we observed intermittent switchings between laminar and
turbulent flows. The switching rate decreases with increasing temperature above 100 mK, until no occurrence of the switchings
at 350 mK. For a 2.4-kHz vibrating wire, we find that the switching rate is much lower than that of the 1.2-kHz vibrating
wire even at low temperatures. This result indicates that a mechanism causing the switchings is influenced by the temperature
and the oscillation frequency of the superfluid flow. 相似文献