Yuri Fujioka
A5055685634- Astro and Planetary Science
- Geological and Geochemical Analysis
- Planetary Science and Exploration
- Isotope Analysis in Ecology
- X-ray Spectroscopy and Fluorescence Analysis
- Nuclear Physics and Applications
- Geological and Geophysical Studies
- Nail Diseases and Treatments
- Cystic Fibrosis Research Advances
- Antifungal resistance and susceptibility
- Seismology and Earthquake Studies
- Geomagnetism and Paleomagnetism Studies
Tohoku University
2022-2024
Hiroshima University
1986
Samples of the carbonaceous asteroid Ryugu were brought to Earth by Hayabusa2 spacecraft. We analyzed 17 samples measuring 1 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent formed in outer Solar System. The contain low abundances materials at high temperatures, such as chondrules and calcium- aluminum-rich inclusions. rich phyllosilicates carbonates, which through aqueous alteration reactions temperature, pH,...
Abstract Returned samples from Cb-type asteroid (162173) Ryugu exhibit very dark spectra in visible and near-infrared ranges, generally consistent with the Hayabusa2 observations. A critical difference is that a structural water absorption of hydrous silicates around twice as deep returned compared those Ryugu’s surface, suggesting surface more dehydrated. Here we use laboratory experiments data to indicate spectral differences between are best explained if has (1) higher porosity, (2)...
The carbonaceous asteroid Ryugu has been explored by the Hayabusa2 spacecraft to elucidate actual nature of hydrous asteroids. Laboratory analyses revealed that samples from are comparable unheated CI chondrites; however, reflectance spectra and CIs do not coincide. Here, we demonstrate sample reproduced heating Orgueil chondrite at 300°C under reducing conditions, which caused dehydration terrestrial weathering products reduction iron in phyllosilicates. Terrestrial accounts for spectral...
Cell-surface hydrophobicities of six Candida species were studied by two methods: measurement the contact angle, and partitioning with aqueous-hydrocarbon (n-octane, n-hexadecane p-xylene) mixtures. C. tropicalis, glabrata krusei adhered better to hydrocarbons than did albicans, stellatoidea parapsilosis. Contact angles for less adherent smaller those more species. Thus methods gave results that similar overall indicated have greater cell-surface
Abstract A fundamental parameter-based quantification scheme for confocal XRF was applied to sub-micron synchrotron radiation X-ray fluorescence (SR-XRF) data obtained at the beamline P06 of Deutsches Elektronen-Synchrotron (DESY, Hamburg, Germany) from two sections C0033-01 and C0033-04 that were wet cut rock fragment C0033 collected Cb-type asteroid (162173) Ryugu by JAXA’s Hayabusa2 mission. Trace-element quantifications show bulk matrix is CI-like, whereas individual mineral grains...
Samples collected from the surface/subsurface of C-type asteroid 162,173 Ryugu by Hayabusa2 mission were nondestructively analyzed in three dimensions (3D). Seventy-three small particles (approximately 10–180 µm size) observed using X-ray nanotomography, with an effective spatial resolution approximately 200 nm. Detailed descriptions these samples terms mineralogy, petrology, and variations among reported. The 57 most common consisted a phyllosilicate matrix containing mineral grains, mainly...
Abstract We analyzed an asteroid Ryugu sample returned to Earth by JAXA's Hayabusa2 mission using nanoIR, SEM, and TEM microscopy. identified multiple distinct carbon reservoirs within the phyllosilicate matrix demonstrate infrared spectral affinities for some of insoluble organic matter (IOM). studies samples have allowed us better understand interrelationship between crystallographic orientations phyllosilicates secondary minerals such as carbonate, sulfide, apatite. Transport elements...
Abstract Preparation procedures of polished sections the Ryugu samples returned by Hayabusa2 spacecraft were established through tests using CI and CM chondrites as analog materials processing samples. The consisted four steps: epoxy‐coating, embedding in epoxy cylinders, cutting with a wire saw, dry polish hand. There are three key points for successful preparation sections: (1) ethanol‐mixed low viscosity reinforcing fragile samples, (2) handling under conditions to avoid breakup on...
Millimetre-sized primordial rock fragments originating from asteroid Ryugu were investigated using high energy X-ray fluorescence spectroscopy, providing 2D and 3D elemental distribution quantitative composition information on the microscopic level. Samples collected in two phases sites safely returned to Earth by JAXA's explorer Hayabusa2, during which time material was stored maintained free terrestrial influences, including exposure Earth's atmosphere. Several grains of interest...