252 research outputs found

    心保存における至適 pH

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    Petrology and mineralogy of the Yamato-86720 carbonaceous chondrite

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    Phyllosilicate clasts in Yamato-86720 consist mainly of dehydrated serpentine (or chlorite) and sodian talc (or saponite) components, which are the most homogeneous in chemical compositions among those in CM chondrites. They were produced from chondrules by intense hydrous alteration, resulting in the homogeneous composition of the phyllosilicates. Metal spherules and troilite grains in original chondrules have also altered to ovoidal phyllosilicate inclusions and unusual carbonate-phyllosilicates inclusions, respectively. The CaO content of the original chondrules was retained within them as the unusual carbonate-phyllosilicate inclusions, which resulted in the low CaO content of the Y-86720 matrix. The matrix is different in composition from the clast phyllosilicates, suggesting that the two were produced in conditions different from each other. Pyrrhotite grains in clasts and matrix have altered probably to ferrihydrite, which have produced Fe-rich halos around the pyrrhotite grains after the agglomeration of Y-86720 and prior to a heating event. The heating event took place in the final stage of the chondrite formation, resulting in dehydration of phyllosilicates and reduction of ferrihydrite to Co-Ni-poor kamacite

    Measurement of Secondary Products During Oxidation Reactions of Terpenes and Ozone Based on the PTR-MS Analysis: Effects of Coexistent Carbonyl Compounds

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    Continuous measurements using proton transfer reaction mass spectrometry (PTR-MS) can be used to describe the production processes of secondary products during ozone induced oxidation of terpenes. Terpenes are emitted from woody building materials, and ozone is generated from ozone air purifiers and copy machines in indoor environments. Carbonyl compounds (CCs) are emitted by human activities such as smoking and drinking alcohol. Moreover, CCs are generated during ozone oxidation of terpenes. Therefore, coexistent CCs should affect the ozone oxidation. This study has focused on the measurement of secondary products during the ozone oxidation of terpenes based on the use of PTR-MS analysis and effects of coexistent CCs on oxidized products. Experiments were performed in a fluoroplastic bag containing α-pinene or limonene as terpenes, ozone and acetaldehyde or formaldehyde as coexistent CCs adjusted to predetermined concentrations. Continuous measurements by PTR-MS were conducted after mixing of terpenes, ozone and CCs, and time changes of volatile organic compounds (VOCs) concentrations were monitored. Results showed that, high-molecular weight intermediates disappeared gradually with elapsed time, though the production of high-molecular weight intermediates was observed at the beginning. This phenomenon suggested that the ozone oxidation of terpenes generated ultrafine particles. Coexistent CCs affected the ozone oxidation of α-pinene more than limonene

    ナンキョクカイ カイテイド ノ ユウキシツ ガンリョウ

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    The samples investigated were collected off Lutzow-Holm Bay in Antarctica by Dr. T. TORII aboard the "SOYA", research ship of the 2nd Japanese Antarctic Research Expedition (1957-58). The summary of the results is as follows (See the appendix). (1) Organic carbon in dry sediments ranges between 0.15 and 0.30% and organic nitrogen varies from 0.014 to 0.032%. However, the value of org. N/org.C, 0.05-0.17, does not differ from the corresponding values for bottom sediments from other ocean floors. (2) Chlorophyll derivatives which express an amount of pheophytin equivalent are 4-17 p.p.m. The values are less than the correspending values for the sediments off California, 18-46 p.p.m. (3) Marine humus, as calculated from the value of organic carbon and TRASK\u27S factor (1.72), varies from 0.3 to 0.5%. The values much differs from the corresponding values for the sediments of the northern Pacific, the southern Pacific and the Atlantic oceans, 1-1.5%, 0.4-1.0% and 0.3-1.5%. (4) Carbonate content shows that the value owes mostly to foraminiferal residues, as CaCO_3 varies from 2 to 11%. The number of the observations so far made is greatly limited. Therefore, the tendencies described above are only approaches to further investigation

    Development of a Combined Real Time Monitoring and Integration Analysis System for Volatile Organic Compounds (VOCs)

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    A combined integration analysis and real time monitoring (Peak Capture System) system was developed for volatile organic compounds (VOCs). Individual integration analysis and real time monitoring can be used to qualitatively and quantitatively analyze VOCs in the atmosphere and in indoor environments and determine the variation in total VOC (TVOC) concentration with time, respectively. In the Peak Capture System, real time monitoring was used to predict future elevations in the TVOC concentration (peak), and this was used an indicator of when to collect (capture) ambient air samples for integration analysis. This enabled qualitative and quantitative analysis of VOCs when the TVOC concentration was high. We developed an algorithm to predict variation in the TVOC concentration, and constructed an automatic system to initiate air sampling for integration analysis. With the system, auto-sampling and analysis of VOCs in a conventional house were conducted. In comparison with background concentrations, the results of peak analysis enabled identification of compounds whose concentration rose. This also enabled an evaluation of possible VOC emission sources
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