The isotopic compositions of samples returned from Cb-type asteroid Ryugu and Ivuna-type (CI) chondrites are distinct from other carbonaceous chondrites, which has led to the suggestion that Ryugu/CI chondrites formed in a different region of the accretion disk, possibly around the orbits of Uranus and Neptune. We show that, like for Fe, Ryugu and CI chondrites also have indistinguishable Ni isotope anomalies, which differ from those of other carbonaceous chondrites. We propose that this unique Fe and Ni isotopic composition reflects different accretion efficiencies of small FeNi metal grains among the carbonaceous chondrite parent bodies.
View Article and Find Full Text PDFCharacterization of the elemental distribution of samples with rough surfaces has been strongly desired for the analysis of various natural and artificial materials. Particularly for pristine and rare analytes with micrometer sizes embedded on specimen surfaces, non-invasive and matrix effect-free analysis is required without surface polishing treatment. To satisfy these requirements, we proposed a new method employing the sequential combination of two imaging modalities, i.
View Article and Find Full Text PDFStudies of material returned from Cb asteroid Ryugu have revealed considerable mineralogical and chemical heterogeneity, stemming primarily from brecciation and aqueous alteration. Isotopic anomalies could have also been affected by delivery of exogenous clasts and aqueous mobilization of soluble elements. Here, we show that isotopic anomalies for mildly soluble Cr are highly variable in Ryugu and CI chondrites, whereas those of Ti are relatively uniform.
View Article and Find Full Text PDFPreliminary analyses of asteroid Ryugu samples show kinship to aqueously altered CI (Ivuna-type) chondrites, suggesting similar origins. We report identification of C-rich, particularly primitive clasts in Ryugu samples that contain preserved presolar silicate grains and exceptional abundances of presolar SiC and isotopically anomalous organic matter. The high presolar silicate abundance (104 ppm) indicates that the clast escaped extensive alteration.
View Article and Find Full Text PDFThe extraterrestrial materials returned from asteroid (162173) Ryugu consist predominantly of low-temperature aqueously formed secondary minerals and are chemically and mineralogically similar to CI (Ivuna-type) carbonaceous chondrites. Here, we show that high-temperature anhydrous primary minerals in Ryugu and CI chondrites exhibit a bimodal distribution of oxygen isotopic compositions: O-rich (associated with refractory inclusions) and O-poor (associated with chondrules). Both the O-rich and O-poor minerals probably formed in the inner solar protoplanetary disk and were subsequently transported outward.
View Article and Find Full Text PDFInitial analyses showed that asteroid Ryugu's composition is close to CI (Ivuna-like) carbonaceous chondrites -the chemically most primitive meteorites, characterized by near-solar abundances for most elements. However, some isotopic signatures (e.g.
View Article and Find Full Text PDFLittle is known about the origin of the spectral diversity of asteroids and what it says about conditions in the protoplanetary disk. Here, we show that samples returned from Cb-type asteroid Ryugu have Fe isotopic anomalies indistinguishable from Ivuna-type (CI) chondrites, which are distinct from all other carbonaceous chondrites. Iron isotopes, therefore, demonstrate that Ryugu and CI chondrites formed in a reservoir that was different from the source regions of other carbonaceous asteroids.
View Article and Find Full Text PDFCarbonaceous meteorites are thought to be fragments of C-type (carbonaceous) asteroids. Samples of the C-type asteroid (162173) Ryugu were retrieved by the Hayabusa2 spacecraft. We measured the mineralogy and bulk chemical and isotopic compositions of Ryugu samples.
View Article and Find Full Text PDFWe performed micro-X-ray fluorescence imaging of frozen-hydrated sections of a root of Pteris vittata for the first time, to the best of our knowledge, to reveal the mechanism of arsenic (As) uptake. The As distribution was successfully visualized in cross sections of different parts of the root, which showed that (i) the major pathway of As uptake changes from symplastic to apoplastic transport in the direction of root growth, and (ii) As and K have different mobilities around the stele before xylem loading, despite their similar distributions outside the stele in the cross sections. These data can reasonably explain As reduction, axially observed around the root tip in the direction of root growth and radially observed in the endodermis in the cross sections, as a consequence of the incorporation of As into the cells or symplast of the root.
View Article and Find Full Text PDFThe striking sub-cellular distribution of cadmium (Cd) and zinc (Zn) in the Cd and Zn hyperaccumulator Arabidopsis halleri ssp. gemmifera was revealed by microbeam X-ray microfluorescence analysis (μ-XRF) using high-energy synchrotron radiation. Plants were grown in hydroponics with various Cd and Zn concentrations.
View Article and Find Full Text PDFSynchrotron radiation (SR) X-ray microbeam analyses revealed the detailed chemical nature of radioactive aerosol microparticles emitted during the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, resulting in better understanding of what occurred in the plant during the early stages of the accident. Three spherical microparticles (∼2 μm, diameter) containing radioactive Cs were found in aerosol samples collected on March 14th and 15th, 2011, in Tsukuba, 172 km southwest of the FDNPP. SR-μ-X-ray fluorescence analysis detected the following 10 heavy elements in all three particles: Fe, Zn, Rb, Zr, Mo, Sn, Sb, Te, Cs, and Ba.
View Article and Find Full Text PDFTrace elemental analysis of soybeans was performed using X-ray fluorescence (XRF) analysis in order to characterise the geographical origins of the beans. By optimising the measurement conditions of an energy-dispersive XRF spectrometer equipped with three-dimensional polarisation optics, determination of trace elements at the sub-μgg(-1) level in soybean samples was accomplished. Forty-six samples were analysed.
View Article and Find Full Text PDFLayered NaNi(0.5)Mn(0.5)O(2) (space group: R ̅3m), having an O3-type (α-NaFeO(2) type) structure according to the Delmas' notation, is prepared by a solid-state method.
View Article and Find Full Text PDFWe have started the construction of a nationwide forensic soil sediment database for Japan based on the heavy mineral and trace heavy element compositions of stream sediments collected at 3024 points all over Japan obtained by high-resolution synchrotron X-ray powder diffraction (SR-XRD) and high-energy synchrotron X-ray fluorescence analysis (HE-SR-XRF). In this study, the performance of both techniques was demonstrated by analyzing soil sediments from two different geological regions, the Kofu and Chiba regions in Kanto province, to construct database that can be applied in the future to provenance analysis of soil evidence from a crime scene. The sediments from the quaternary volcanic lithology of the Chiba region were found to be dominated by heavy minerals of volcanic origin - orthopyroxene, clinopyroxene, and amphibole, and the REEs (rare earth elements) within the region showed similar geochemical behavior.
View Article and Find Full Text PDFTrees that accumulate metals are important plants for restoring contaminated soil because of their high biomass. In our previous study, we discovered that Salix miyabeana has the capability to take up high levels of Cd, and identified the several accumulation sites of the endogenous metals in the leaf parts of plants. To analyze the detailed localization of Cd in apoplastic and symplastic compartments in S.
View Article and Find Full Text PDFMarine mammals accumulate mercury in their tissues at high concentration and detoxify by forming mercury selenide (HgSe, tiemannite) mainly in the liver. We investigated the possibility of formation of HgSe in various tissues (liver, kidney, lung, spleen, pancreas, muscle and brain) other than the liver of the striped dolphin (Stenella coeruleoalba). We applied a combination method of micro-X-ray fluorescence (μ-XRF) imaging and micro-X-ray diffraction (μ-XRD) using a synchrotron radiation X-ray microbeam to analyze the tissue samples directly with minimal sample preparation.
View Article and Find Full Text PDFLithium-excess manganese layered oxides, which are commonly described by the chemical formula zLi(2)MnO(3)-(1-z)LiMeO(2) (Me = Co, Ni, Mn, etc.), are of great importance as positive electrode materials for rechargeable lithium batteries. In this Article, Li(x)Co(0.
View Article and Find Full Text PDFIn vivo X-ray analysis utilizing synchrotron radiation was performed to investigate the distribution and oxidation state of arsenic in the gametophytes of two hyperaccumulators, Pteris vittata L. and Pteris cretica L., and an arsenic-accumulating fern, Athyrium yokoscense in the several growth stages from germination.
View Article and Find Full Text PDFTrees that accumulate metals are important plants for restoring contaminated soil because of their high biomass. We examined the cadmium (Cd) tolerance and growth rate of six willow (Salix) species common in Japan. To characterize in detail the localization of Cd and its ligands, synchrotron radiation-based micro X-ray fluorescence analysis was used.
View Article and Find Full Text PDFBlue-painted pottery was produced in the New Kingdom, Egypt, and decorated with blue, red, and black pigment. In this study, two newly developed portable instruments, a portable X-ray fluorescence spectrometer and a portable X-ray powder diffractometer, were brought to the site on the outcrop at Northwest Saqqara, an archaeological site in Egypt, to verify their performance in on-site analysis of excavated artifacts at the site. Pigments used for the blue-painted pottery and plasters in the New Kingdom were analyzed by these instruments on the basis of both their chemical compositions and crystal-structural information.
View Article and Find Full Text PDFHigh-energy synchrotron radiation x-ray fluorescence spectrometry (SR-XRF) utilizing 116 keV x-rays was used to characterize titanium dioxide pigments (rutile) and automotive white paint fragments for forensic examination. The technique allowed analysis of K lines of 9 trace elements in 18 titanium dioxide pigments (rutile), and 10 trace elements in finish coat layers of seven automotive white paint fragments. High-field strength elements (HFSE) were found to strongly reflect the origin of the titanium dioxide (TiO(2)) pigments, and could be used as effective parameters for discrimination and classification of the pigments and paint fragments.
View Article and Find Full Text PDFLayered cesium tungstate, Cs(6+x)W(11)O(36), with two-dimensional (2D) pyrochlore structure was exfoliated into colloidal unilamellar sheets through a soft-chemical process. Interlayer Cs ions were replaced with protons by acid exchange, and quaternary ammonium ions were subsequently intercalated under optimized conditions. X-ray diffraction (XRD) measurements on gluelike sediment recovered from the colloidal suspension by centrifugation showed a broad pattern of a pronounced wavy profile, which closely matched the square of calculated structure factor for the single host layer.
View Article and Find Full Text PDFNanosheets can be used as building blocks to fabricate versatile nanostructured materials. In this paper, morphology of the Cs(4)W(11)O(36) and Nb(3)O(8) and TaO(3) sheets with different layers are analyzed by different field-emission scanning electron microscopes (FE-SEMs). Chemical composition of the single-layered Cs(4)W(11)O(36) with thickness of about 2 nm, and multilayered Nb(3)O(8) nanosheets with thickness of less than 14 nm are analyzed by both the Si(Li) solid-state detector and transition edge sensor (TES) microcalorimeter, successfully.
View Article and Find Full Text PDFThe comprehensive characterization of As(V)-bearing iron minerals from the Gunma iron deposit, which were probably formed by biomineralization, was carried out by utilizing multiple synchrotron radiation (SR)-based analytical techniques at BL37XU at SPring-8. SR microbeam X-ray fluorescence (SR-mu-XRF) imaging showed a high level of arsenic accumulation in the iron ore as dots of ca. 20 microm.
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