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Volume 59, Issue 3
Displaying 1-12 of 12 articles from this issue
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Articles
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Sayuri ITO, Nobuo SUZUI, Naoki KAWACHI, Satomi ISHII, Noriko S. ISHIOK ...2010 Volume 59 Issue 3 Pages 145-154
Published: 2010
Released on J-STAGE: March 29, 2010
JOURNAL OPEN ACCESSAllocation of photosynthates to root nodules in soybean plants was analyzed non-invasively using 11CO2 and positron-emitting tracer imaging system(PETIS). In particular, distribution of 11C-photosynthates in the underground part of a hypernodulation mutant that forms a lot of small nodules on the root and shows reduced growth was characterized by comparison to wild-type. Both in the mutant and wild-type. 11C-photosynthates were transported to the root base within about 20 min after feeding of 11CO2 and to the root tips within one hour. Most of 11C-photosynthates in the underground part were localized to the root base where packed nodules are found. It was shown that larger amount of 11C-photosynthates was transported into the nodules on the root base than into those on distal regions, both per nodule and per volume of nodule. This suggested that the basal nodules may have higher activity for nitrogen fixation both in the mutant and wild-type, and such position of a nodule may be a dominant determining factor for the activity. Moreover, there was no difference between the mutant and wild-type in the amount of 11C-photosynthates accumulated into the nodules per volume of nodule, both in basal and distal regions. These results suggested that the reduced activity of nitrogen fixation in the mutant might be generally caused by the increased proportion of the distal nodules which are poorly fed with photosynthates, but not just by the increased total number of nodules. This is the first report of photosynthate translocation into the individual nodules in an intact soybean with real-time observation.View full abstractDownload PDF (1656K) -
Masato YAMAWAKI, Atsushi HIROSE, Satomi KANNO, Hiroki ISHIBASHI, Akihi ...2010 Volume 59 Issue 3 Pages 155-162
Published: 2010
Released on J-STAGE: March 29, 2010
JOURNAL OPEN ACCESSIn this study, real-time imaging using γ-emitting nuclide, 109Cd, was studied and sensitivity and resolution of the system we developed was evaluated. When RI was applied to the plant, the radiation from the RI distributed throughout the plant was converted to visible light by a scintillator. Then, this weak light was multiplied by a micro-channel plate(MCP)and photographed by a charge-coupled device(CCD)camera. 109Cd emits 88keV γ-rays together with 22keV X-rays, and therefore it is necessary to investigate effective condition for designing an observation system for the measurement of radiation from 109Cd. Analysis was performed to determine which rays, γ-rays or X-rays, were mainly detected by this system and the optimal scintillator thickness for imaging 109Cd was investigated. Then the sensitivity and resolution of the system was evaluated.View full abstractDownload PDF (1511K) -
Kiyoshi SHIZUMA, Hiroshi TAKATORI, Kodai TAKENAKA, Ayanori MURATAKA, Y ...2010 Volume 59 Issue 3 Pages 163-171
Published: 2010
Released on J-STAGE: March 29, 2010
JOURNAL OPEN ACCESSA new method to measure the concentration of uranium and radium in ground water has been developed. One-liter of ground water was evaporated on a Teflon sheet and measured with a low background Ge detector. According to the decay of 238U, radio equilibrium has been achieved between 238U and progeny 234Th after about 150days. 238U concentration can be determined from the gamma-ray measurement of the dry up sample. Ground water samples were collected from 58 locations in Hiroshima prefecture. Radon concentration was measured directly from the 250mL water sample. It has been shown that dependence of uranium, radium and radon concentration on the geological map in Hiroshima prefecture. A clear correlation was observed between uranium and radium concentration, but not between uranium and radon concentration.View full abstractDownload PDF (1935K)
Note
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Shigeyoshi SOGA, Tamotsu KITA, Miyuki HIRATSUKA, Chiharu SAKAGUCHI, Hi ...2010 Volume 59 Issue 3 Pages 173-177
Published: 2010
Released on J-STAGE: March 29, 2010
JOURNAL OPEN ACCESSSerial fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography(18F-FDG PET/CT)studies were performed with an interval of one year in a 62-year-old man with IgG4-associated multifocal systemic fibrosis(IMSF). He first underwent 18F-FDG PET/CT cancer screening, which revealed multiple 18F-FDG-avid uptakes in the pancreas, prostate, and lymph nodes in the upper mediastinum, pulmonary hila, porta hepatis, and the left iliac and inguinal regions. He was not symptomatic at this initial examination. The follow-up 18F-FDG PET/CT study showed disappearance of 18F-FDG-avid uptake foci in the pancreas despite no treatment having been administered, but demonstrated new lesions in the abdominal para-aortic region and more intense FDG uptake in the porta hepatis lesion. Serial 18F-FDG PET/CT studies might be useful in monitoring patients with IMSF, as well as evaluating the state of systemic involvement. Findings of 18F-FDG PET/CT may provide information useful for determining the optimal initiation of IMSF treatment.View full abstractDownload PDF (204K)
Serial Lectures
Fundamentals and Applications of Neutron Diffraction
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Kenji OHOYAMA2010 Volume 59 Issue 3 Pages 179-189
Published: 2010
Released on J-STAGE: March 29, 2010
JOURNAL OPEN ACCESSThe neutron powder diffraction technique is the one of most important experiments for novel material science from academic and practical view points. In particular, for structural investigations of light elements, such as hydrogen, oxygen, lithium, which play main roles in novel environmental application materials, the neutron powder diffraction is indispensable. In this article, explanations of each process of structure refinement from neutron diffraction experiments to analysis will be instantiated. As an example, the structure refinement of the hydride Li2NH, which is attracted our attention as a candidate of high performance hydrogen storage materials, will be explained. The neutron diffraction experiment has revised the hydrogen structure of Li2NH which was determined by X-ray diffraction. From the structure refinement, partially occupied hydrogen structures with covalent bonding with nitrogen has been proposed.View full abstractDownload PDF (1218K) -
Fujio IZUMI2010 Volume 59 Issue 3 Pages 191-200
Published: 2010
Released on J-STAGE: March 29, 2010
JOURNAL OPEN ACCESSThis review describes two methods of structure refinement from neutron powder diffraction data. In the Rietveld method, lattice, structure, profile, and other parameters are refined by nonlinear least-squares methods. On the other hand, in pattern fitting based on the maximum entropy method (MEM), i.e., the MPF method, the crystal structure is virtually represented by scattering-length densities in the unit cell. The MPF method is, therefore, very useful for studying spatial distribution of chemical species with highly disordered arrangement and anharmonic thermal motion.View full abstractDownload PDF (1055K) -
Masatomo YASHIMA2010 Volume 59 Issue 3 Pages 201-210
Published: 2010
Released on J-STAGE: March 29, 2010
JOURNAL OPEN ACCESSThe crystal structure and ionic diffusion path of ionic and mixed ionic-electronic conductors, which are important in a variety of applications such as fuel cells, gas sensors, catalyst and batteries, are reviewed. α-AgI has many occupational sites of mobile Ag ions. β-alumina exhibits two-dimensional Na ionic diffusion. In the fluorite-structured superionic conductors such as ceria solid solution Ce0.93Y0.07O1.96, bismuth oxide solid solution δ-Bi1.4Yb0.6O3 and copper iodide CuI, a similar curved diffusion pathway along the <100> directions is observed. In the ionic conductors with the cubic ABO3 perovskite-type structure such as lanthanum gallate and lanthanum cobaltite solid solutions, the mobile ions diffuses along a curved line keeping the interatomic distance between the B cation and O2− anion to some degree. The structure and diffusion path of double-perovskite-type La0.64Ti0.92Nb0.08O2.99, K2NiF4-type(Pr0.9La0.1)2(Ni0.74Cu0.21Ga0.05)O4+δ, and apatite-type La9.69(Si5.70Mg0.30)O26.24 are described. The structure and diffusion path of lithium-ion conductors La0.62Li0.16TiO3 and Li0.6FePO4 are also discussed. The diffusion paths of La0.62Li0.16TiO3 and Li0.6FePO4 are two-and one-dimensional, respectively.View full abstractDownload PDF (1129K) -
Takashi MOCHIKU2010 Volume 59 Issue 3 Pages 211-219
Published: 2010
Released on J-STAGE: March 29, 2010
JOURNAL OPEN ACCESSCrystal structure analysis with neutron diffraction is necessary for the study of high-Tc oxide superconductors, which oxygen atoms play an important role in. The crystal structure of a lot of superconductors has been analyzed by neutron powder diffraction. On the basis of the neutron powder diffraction study, the guiding principle of material design in high-Tc oxide superconductors has been constructed, and contributes the discovery of new materials. The crystallographic data obtained by the neutron powder diffraction study is also the fundamentals to the study for the exotic physical properties in high-Tc oxide superconductors.View full abstractDownload PDF (984K) -
Masatomo YASHIMA2010 Volume 59 Issue 3 Pages 221-229
Published: 2010
Released on J-STAGE: March 29, 2010
JOURNAL OPEN ACCESSA brief review of neutron powder diffractometry, which is applied to the studies of the crystal structure and nuclear-density distribution, and to the study of the existing phases and phase transition of inorganic catalysts is presented. Occupancy of oxygen atom at nitrogen atomic site can be refined by the Rietveld analysis of neutron diffraction data of oxynitride photocatalysts. Crystal structure, phase transition and nuclear-density distribution of ceria-zirconia automobile exhaust gas catalysts have been investigated by the neutron diffractometry. Atomic displacement parameters and nuclear density enable to discuss the oxygen-ion diffusivity and catalytic activity. Neutron diffractometry has been utilized to study the crystal structure and diffusion pathway of oxygen ions in perovskite-type and related oxides.View full abstractDownload PDF (1133K) -
(Applications 7)Crystal Structure Analysis of Fuel Cell Materials by Means of Neutron DiffractometryTakanori ITOH2010 Volume 59 Issue 3 Pages 231-238
Published: 2010
Released on J-STAGE: March 29, 2010
JOURNAL OPEN ACCESSPerovskite oxides, which have “A” atoms of an alkaline earth metal and/or a rare earth metal and “B” atoms of a transition metal, have considerable potential for use in electrochemical devices such as cathodes of solid oxide fuel cells(SOFC), oxygen pumps, oxygen sensors, catalysts, and other devices such as oxygen separation membranes. The oxygen ion behavior is studied with relation performance of electrochemical devices. I have analyzed the crystal structure of SOFC materials by neutron diffraction. Using the Rietveld refinement technique, I showed that the O1(4c) and O2(8d) sites in a perovskite oxide of SOFC cathode material have different oxygen site occupancies. Furthermore, oxygen diffusion behavior is associated with temperature dependence of oxygen anisotropic atomic displacement parameters. The maximum entropy method (MEM) analysis of neutron diffraction measurements revealed nuclear scattering length distribution at high temperature by three-dimensional images in detail, therefore I found oxygen diffusion pass and new proton site in SOFC materials. From these results, neutron diffraction is confirmed to be very useful tool for the study of light element behavior in fuel cell materials.View full abstractDownload PDF (1000K) -
Hiroshi FUKAZAWA2010 Volume 59 Issue 3 Pages 239-247
Published: 2010
Released on J-STAGE: March 29, 2010
JOURNAL OPEN ACCESSThe complex behavior of water and the unusual properties of proton ordering in ferroelectric ice crystal continue to attract much interest. Whether ice in the space exists as proton-ordered ices, is an important question. Some ordered ices have ferroelectricity, and long range electrostatic forces caused by the ferroelectricity might be an important factor for planet formation. From neutron diffraction experiments, we found the temperature conditions for the transformation of the largest fraction of ice into ferroelectric ice using the lowest level of impurity dopant. It suggests that myriad big icy-bodies, which exist as dwarf planets and Kuiper Belt Object, consist of thick ferroelectric-ice surface.View full abstractDownload PDF (1034K) -
Koji KANEKO2010 Volume 59 Issue 3 Pages 249-256
Published: 2010
Released on J-STAGE: March 29, 2010
JOURNAL OPEN ACCESSStructural analysis on the cubic skutterudite compound PrOs4Sb12 by single crystal neutron diffraction is presented. There are surge of interests on large-amplitude thermal vibration of a guest ion inside an over-sized cage, called “rattling”, and its relationship with their physical properties. A combination of single crystal neutron diffraction and analysis by maximum-entropy method offers an ability to reveal detailed potential shape and anharmonicity in real space without the need for specific model. A clear picture of rattling in PrOs4Sb12 is successfully revealed.View full abstractDownload PDF (778K)
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