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Introduct of the development process of the combined barrier system with re-inforced concret pit and bentnite mixed sand and the contribution of geochemical performance analysis.

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Sulfur dioxide is one of the many trace gases present in the atmosphere. The photodissociation reaction by UV light initiates a complicated oxidation process which its final product sulfates and sulfuric acid form aerosols. Since the measurement of absolute absorption cross sections of isotopologues is a complicated task a dual beam spectrometer (DBS) was designed and built for the purpose of measuring ratio of absorption cross-sections of the isotopologues: 32SO2, 33SO2, 34SO2 and 36SO2 with high precision.

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From petrographic study, a large Allende type B inclusion, Golfball has experienced at least two melting events. In the present study, we report preliminary results of oxygen and Al-Mg isotopic measurements of spinel and melilite in Golfball to determine ages of the multiple melting events and the oxygen isotopic composition of each melt. Delta O-18= -50 to -40permil for spinel, and the oxygen isotopic composition of melilite is distinct in each petrographic occurrence: Delta O-18= -20 to -10permil for gehlenitic core melilite and Delta O-18= ~0permil for melilite in the rim. Two isochrons are defined by the Al-Mg data. The gehlenitic core melilite and rim melilite yield initial ²⁶Al/²⁷Al ratios of 4.9+-0.8 and 1.9+-1.2x10^-5, respectively. The age difference between the two isochrons is calculated to be about 1 My. From the chronological and the previous petrographic studies, we discuss the crystallization history of Golfball.

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We report high-precision Mg isotopic measurements in melilite, spinel and fassaite in an Allende CAI by a NanoSIMS 50L with 4 Faraday cups in meltidetection in order to evaluate the chronology and thermal history of CAIs in the early solar system. We found an initial 26Al/27Al ratio of 4.67 (± 0.22, 2σ) x 10-5 and δ26Mg intercept of 0.18 (± 0.05, 2σ) ⁰/₀₀. We calculated an initial cooling rate for the CAI at 1450C using Mg diffusion kinetics in spinel. An initial cooling rate of at least 0.5 to 11C/h at 1450C is required to preserve the original 26Mg* in spinel through the formation process.

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The planetary sample curation facility in JAXA has been established for acceptances of various planetary samples acquired by future sample return missions. Its functions and performance tests have been performed in preparation for the sample returned by Hayabusa spacecraft in June, 2010. In the tests, the procedures of the sample acceptance, opening the sample container, sample recovery, preservation, weighing and separation have been confirmed. Further researches and developments corresponding to small samples which could not been treated inside clean chambers are being performed in parallel with rehearsal of the sample curation for the upcoming Hayabusa sample return.

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In order to elucidate the primitive materials and evolution history of enstatite (E) chondrites, we have investigate EH3, EH4 and EL4 chondrites using optical/electron microscopes and a laser Raman microscope. Matrix and chondrule rims in an EH3 chondrite pair, Sahara 97096/97158/97121, consist of fine-grained (<20 micrometer) materials, such as enstatite, troilite, FeNi metal, SiO2 (cristobalite), graphite and niningerite. The matrix and rims show variations in sizes of their constituent minerals and in the mineralogy. A chondrule rim contacts with a FeNi metal/troilite lump containing enstatite lath. These features suggest that the Sahara EH3 chondrite could be a primitive breccia forming through re-accumulation of the fine-grained primitive materials and secondary materials that have been produced by impact shock heating prior to the final accumulation.

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Carbonaceous chondrites often contain carbonates to which Mn-Cr dating are applicable. However, formation ages of carbonates obtained in previous studies are not necessarily consistent with ages calculated by other chronometers. In this study, we prepared a synthetic Mn and Cr bearing caltite and evaluated a Mn/Cr relative sensitivity factor. As a result, we obtained formation ages about 3 My younger than those obtained in previous studies.

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The final purpose of this study is to discuss the frequency of meteorite falls. When a meteorite enters to atmosphere of the Earth, sometimes single meteorite body is broken to several pieces. Therefore the number of meteorite falls is not equal to the number of meteorite pieces. Pairing of meteorites is important information to discuss the frequency of meteorite falls. In this study, we carried out grouping of 47 Yamato HED meteorites based on their ²⁶Al concentration and their chemical compositions.

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This study aims to characterize three howardites and three polymict eucrites based on rare earth and other trace element abundances. It is also aimed to identify possible carrier phase(s) of siderophile elements in polymict breccias and discuss their origin. Howardites (Y-7308 and Y-791573) and polymict eucrites (Y-75015, Y-74450 and Y792769) show lower siderophile pattern than those for Kapoeta but higher abundance than those in monomict eucrites. Their siderophile elemental ratios are non-chondritic, suggesting non-chondritic materials as projectiles (e.g., iron meteorites). This is consistent with our previous study that polymict eucrites contain a variety of non-chondritic projectiles. The current study implies that the HED parent body experienced multiple impacts of chemically variable projectiles.

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We summarise biogenic manganese oxide formation processes by a Mn oxidizing fungus and its application to recovery of various elements from waste waters.

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In order to document the source of arsenic of the arsenic contaminated groundwater in the Ganges-Bramaptra Plains, detrital biotite and chlorite were analyzed by microbeam XRF in SPring-8. Although the biotite rarely included detectable arsenic, the chlorite included arsenic ubiquitously in the crystal. The arsenic concentration of chlorite could be quantified, a few tens to hundreds ppm was estimated from the X-ray intensities in comparison with arsenic bearing minerals such as realgar and arsenocpyrite. The chlorite included submicron-order size goethite, assured by X-ray diffraction using Gandorfi camera and TEM observation. However, the goethite was not a product of chemical weathering in situ, judged from the well crystallized nature. Unlike the widely accepted hypothesis, in which the adsorbed arsenic onto Fe-hydroxides via chemical weathering of arsenic bearing sulfide minerals in Himalayas was released into groundwater in association with microbial reduction-dissolution of the Fe-hydroxides, the arsenic was released from the chlorite in the aquifer.

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