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Your search keyword '"Takeyama, M."' showing total 17 results
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17 results on '"Takeyama, M."'

1. Production of Bh 266 in the Cm 248 (Na 23,5n) Bh 266 reaction and its decay properties

Author

Haba, H., Fan, F., Kaji, D., Kasamatsu, Y., Kikunaga, H., Komori, Yukiko, Kondo, N., Kudo, H., Morimoto, K., Morita, K., Murakami, M., Nishio, K., Omtvedt, Jon Petter, Ooe, K., Qin, Zhi, Sato, D., Sato, N., Sato, T.K., Shigekawa, Y., Shinohara, A., Takeyama, M., Tanaka, T., Toyoshima, A., Tsukada, Kazuaki, Wakabayashi, Y., Wang, Y., Wulff, Solveig Birgitte Aker, Yamaki, S., Yano, S., Yasuda, Y., and Yokokita, T.

Abstract

The nuclide 266Bh was produced in the 248Cm(23Na,5n)266Bh reaction at beam energies of 125.9, 130.6, and 135.3 MeV. Decay properties of 266Bh were investigated with a rotating wheel apparatus for α and spontaneous fission (SF) spectrometry under low background conditions attained by a gas-jet transport system coupled to the RIKEN gas-filled recoil ion separator. Based on genetically correlated α−α and α-SF decay chains, a total of 23 chains were assigned to 266Bh and its daughter nuclide 262Db and granddaughter 258Lr. The half-life of 266Bh was measured to be T1/2=10.0+2.6−1.7s which is an order of magnitude longer than the literature data. The α-particle energies of 266Bh disperse widely in the range of Eα=8.62–9.40MeV. The maximum production cross section for the 248Cm(23Na,5n)266Bh reaction was determined to be σ=57±14 pb at 130.6 MeV, whereas the upper limit for the 248Cm(23Na,4n)267Bh reaction was σ≤14 pb at 121.2 MeV. These cross sections are discussed by comparing with the literature data as well as the theoretical calculations.

Published
2020

4. A new coupling agent for composite materials: 4-Methacryloxyethyl trimellitic anhydride

Author

D. T. Turner, Nobuo Nakabayashi, Takeyama M, M. Atsuta, and A. K. Abell

Subjects
Materials science, Surface Properties, Biomedical Engineering, Modulus, Fractography, Silanes, Composite Resins, Biomaterials, chemistry.chemical_compound, Trimellitic anhydride, Acrylates, Solubility, chemistry, Tensile Strength, visual_art, Knoop hardness test, visual_art.visual_art_medium, Methacrylates, Chloroform, Ceramic, Dewetting, Methyl methacrylate, Composite material, Dental Restoration, Permanent, Porosity
Abstract

Composite materials were made by sedimention of ceramic powders in methyl methacrylate which was then polymerized by gamma-irradiation. Inclusion of 4-methacryloxyethyl trimellitic anhydride (4-META) generally was found to result in an increase in Knoop hardness number, Young's modulus, and transverse strength. Most emphasis was placed on transverse strength which was found to be increased by ca. 30% by inclusion of 4-META (5 wt %) in composites made with silanated LiAlSiO4. However an abrupt decrease in strength was found for composites with greater than ca. 83 wt % silanated LiAlSiO4. This was shown by fractography to be due to increased porosity and dewetting at the higher filler contents. Fractography also indicated that inclusion of 4-META results in a more coherent polymeric matrix. Further evidence for greater coherence was obtained by showing that 4-META confers resistance to disintegration by chloroform.

Published
1982

5. 4-META opaque resin--a new resin strongly adhesive to nickel-chromium alloy

Author

Toshio Tanaka, K Nagata, Takeyama M, M. Atsuta, Nobuo Nakabayashi, and Eiichi Masuhara

Subjects
0301 basic medicine, Chromium, Materials science, Surface Properties, medicine.medical_treatment, Alloy, Acrylic Resins, Thermosetting polymer, Dental bonding, engineering.material, 03 medical and health sciences, 0302 clinical medicine, Nickel, medicine, Composite material, General Dentistry, Acrylic resin, Bond strength, Epoxy Resins, Dental Bonding, Adhesiveness, 030206 dentistry, Epoxy, 030104 developmental biology, Acrylates, visual_art, visual_art.visual_art_medium, engineering, Methacrylates, Veneer, Adhesive, Dental Alloys
Abstract

1) A new adhesive opaque resin containing a reactive monomer, 4-methacryloxy-ethyl trimellitate anhydride (4-META), was prepared, and its application to thermosetting acrylic resin veneer crowns was studied. 2) The 4-META opaque resin was applied to a variety of nickel-chromium dental alloy specimens which had undergone different treatment, and endurance tests were conducted to evaluate the durability of adhesion. 3) Stable adhesion against water penetration was achieved with metal surfaces first etched with HCl and then oxidized with HNO3. A bond strength of 250 kg/cm2 was maintained even after immersion in water at 37 degrees C for 30 wk or at 80 degrees C for ten wk. Furthermore, this value did not decrease even after the specimens were subjected to 500 thermal cycles. 4) The 4-META opaque resin studied can eliminate the necessity for retention devices on metal castings. 5) The smooth 4-META opaque resin should have no adverse effects on gingivae.

Published
1981

6. [Decomposition and stabilization of drugs. II. Stabilities of aqueous solution of 2-diethylaminoethyl 3-methyl-2-phenylvalerate hydrochloride and its methobromide]

Author

Otani H, Noriko Ikari, Nogami H, Takeyama M, and Kigasawa K

Subjects
Pharmacology, Aqueous solution, Chemistry, Hydrochloride, Pharmaceutical Science, Buffers, Hydrogen-Ion Concentration, Decomposition, Solutions, chemistry.chemical_compound, Drug Stability, Spectrophotometry, Valerates, Chromatography, Thin Layer, Nuclear chemistry
Published
1970

15. In situ synthesis of volatile carbonyl complexes with short-lived nuclides

Author

Takayuki Sumita, Yuichiro Nagame, Julia Even, Antonio Di Nitto, A. Hübner, S. Yamaki, Mirei Takeyama, J. Maurer, Daiya Kaji, Egon Jäger, W. Hartmann, J. Kanaya, Matthias Schädel, Heino Nitsche, Jens Volker Kratz, Mustapha Laatiaoui, Kouji Morimoto, Alexander Yakushev, Minqhiu Huang, J. Krier, Y. Kudou, J. Steiner, I. Usoltsev, Christoph E. Düllmann, Kosuke Morita, Yasuo Wakabayashi, Masato Asai, Bettina Lommel, Sunao Miyashita, Atsushi Toyoshima, H. Brand, Norbert Wiehl, Masashi Murakami, Kazuaki Tsukada, Z. H. Qin, K. Tanaka, Andreas Türler, Fangli Fan, Nikolaus Kurz, Yang Wang, Robert Eichler, Jadambaa Khuyagbaatar, Birgit Kindler, Dieter Ackermann, Hiromitsu Haba, Y. Kaneya, Kazuhiro Ooe, F. P. Heßberger, Michael Block, Tetsuya Sato, Even, J., Ackermann, D., Asai, M., Block, M., Brand, H., Di Nitto, A., Dullmann, C. E., Eichler, R., Fan, F., Haba, H., Hartmann, W., Hubner, A., Hessberger, F. P., Huang, M., Jager, E., Kaji, D., Kanaya, J., Kaneya, Y., Khuyagbaatar, J., Kindler, B., Kratz, J. V., Krier, J., Kudou, Y., Kurz, N., Laatiaoui, M., Lommel, B., Maurer, J., Miyashita, S., Morimoto, K., Morita, K., Murakami, M., Nagame, Y., Nitsche, H., Ooe, K., Qin, Z., Sato, T. K., Schadel, M., Steiner, J., Sumita, T., Takeyama, M., Tanaka, K., Toyoshima, A., Tsukada, K., Turler, A., Usoltsev, I., Wakabayashi, Y., Wang, Y., Wiehl, N., Yakushev, A., and Yamaki, S.

Subjects
Nuclear fission product, Metal carbonyl complexe, Superheavy elements, Health, Toxicology and Mutagenesis, chemistry.chemical_element, Transactinide element, Metal carbonyl, 7. Clean energy, Analytical Chemistry, Isotope separation, law.invention, Transition metal, law, 540 Chemistry, Physical preseparation, Seaborgium, Radiology, Nuclear Medicine and imaging, Nuclide, Spectroscopy, Isotope, Radiochemistry, Public Health, Environmental and Occupational Health, Pollution, Nuclear Energy and Engineering, chemistry, 570 Life sciences, biology, Nuclear fusion product
Abstract

Rapid in situ formation of metal carbonyl complexes with short-lived nuclides has been demonstrated to be feasible with recoiling ions formed in nuclear fusion and fission reactions. These carbonyl complexes are highly volatile and can be transported rapidly in a gas-stream to counting or chemistry devices. This method was already successfully applied in the chemical investigation of the superheavy element seaborgium (Z = 106) and appears promising for various fields of nuclear research. In this article, we give an overview on the current status of metal carbonyl complex studies with short-lived d-element isotopes.

Published
2015
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16. Synthesis and detection of a seaborgium carbonyl complex

Author

J. Steiner, Masashi Murakami, Takayuki Sumita, Mirei Takeyama, Fangli Fan, A. Di Nitto, Yasuo Wakabayashi, Bettina Lommel, Sunao Miyashita, Kosuke Morita, J. Krier, Atsushi Toyoshima, M. Huang, Zhi Qin, J. V. Kratz, Norbert Wiehl, Tetsuya Sato, J. Kanaya, Birgit Kindler, N. Kurz, H. Haba, K. Tanaka, Y. Nagame, Daiya Kaji, Kazuaki Tsukada, Masato Asai, K. Morimoto, S. Yamaki, H. Brand, Heino Nitsche, Ch. E. Düllmann, Y. Kaneya, Y. Kudou, Yuezhao Wang, Kazuhiro Ooe, Alexander Yakushev, Julia Even, W. Hartmann, Egon Jäger, I. Usoltsev, Andreas Türler, Matthias Schädel, Robert Eichler, Jadambaa Khuyagbaatar, Even, J., Yakushev, A., Dullmann, Ch. E., Haba, H., Asai, M., Sato, T. K., Brand, H., Di Nitto, A., Eichler, R., Fan, F. L., Hartmann, W., Huang, M., Jager, E., Kaji, D., Kanaya, J., Kaneya, Y., Khuyagbaatar, J., Kindler, B., Kratz, J. V., Krier, J., Kudou, Y., Kurz, N., Lommel, B., Miyashita, S., Morimoto, K., Morita, K., Murakami, M., Nagame, Y., Nitsche, H., Ooe, K., Qin, Z., Schadel, M., Steiner, J., Sumita, T., Takeyama, M., Tanaka, K., Toyoshima, A., Tsukada, K., Turler, A., Usoltsev, I., Wakabayashi, Y., Wang, Y., Wiehl, N., and Yamaki, S.

Subjects
Multidisciplinary, Stereochemistry, chemistry.chemical_element, Structural formula, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, chemistry.chemical_compound, chemistry, Transition metal, CHEMISTRY, Seaborgium, 0103 physical sciences, TRANSITION-METAL, ELEMENTS, Physical chemistry, SG(CO)(6), 010306 general physics, Carbon, Helium, Carbon monoxide
Abstract

A carbonyl compound that tips the scales Life is short for the heaviest elements. They emerge from high-energy nuclear collisions with scant time for detection before they break up into lighter atoms. Even et al. report that even a few seconds is long enough for carbon to bond to the 106th element, seaborgium (see the Perspective by Loveland). The authors used a custom apparatus to direct the freshly made atoms out of the hot collision environment and through a stream of carbon monoxide and helium. They compared the detected products with theoretical modeling results and conclude that hexacarbonyl Sg(CO) 6 was the most likely structural formula. Science , this issue p. 1491 ; see also p. 1451

Published
2014
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17. Complex chemistry with complex compounds

Author

Sunao Miyashita, T. Tomitsuka, Yongfeng Wang, H. Brand, Daiya Kaji, M. Murakami, N.M. Chiera, Patrick Steinegger, S. Yano, Kazuaki Tsukada, K. Tanaka, Egon Jäger, Ch. E. Düllmann, Y. Kaneya, Alexander Yakushev, Birgit Kindler, Takayuki Sumita, Atsushi Toyoshima, Z. Qin, Yuichiro Nagame, Norbert Wiehl, Y. Kudou, Mirei Takeyama, Y. Wittwer, Robert Eichler, K. Morimoto, S. Yamaki, Rugard Dressler, N. Sato, Jens Volker Kratz, F. Fangli, H. Haba, J. Krier, B. Kraus, A. Di Nitto, Tatsuhiko Sato, Julia Even, J. Kanaya, N. Kurz, D. Piguet, W. Hartmann, Yukiko Komori, Yasuo Wakabayashi, M. Goetz, J. Steiner, K. Morita, J. Khuyagbaatar, I. Usoltsev, M. Asai, Kazuhiro Ooe, Andreas Türler, Eichler, R., Asai, M., Brand, H., Chiera, N. M., Di Nitto, A., Dressler, R., Dullmann, Ch. E., Even, J., Fangli, F., Goetz, M., Haba, H., Hartmann, W., Jager, E., Kaji, D., Kanaya, J., Kaneya, Y., Khuyagbaatar, J., Kindler, B., Komori, Y., Kraus, B., Kratz, J. V., Krier, J., Kudou, Y., Kurz, N., Miyashita, S., Morimoto, K., Morita, K., Murakami, M., Nagame, Y., Ooe, K., Piguet, D., Sato, N., Sato, T. K., Steiner, J., Steinegger, P., Sumita, T., Takeyama, M., Tanaka, K., Tomitsuka, T., Toyoshima, A., Tsukada, K., Turler, A., Usoltsev, I., Wakabayashi, Y., Wang, Y., Wiehl, N., Wittwer, Y., Yakushev, A., Yamaki, S., Yano, S., and Qin, Z.

Subjects
Physics, QC1-999, Transactinide element, chemistry.chemical_element, Tungsten, 010402 general chemistry, 010403 inorganic & nuclear chemistry, 01 natural sciences, 0104 chemical sciences, Metal, chemistry, Group (periodic table), Computational chemistry, Molybdenum, Chemical physics, visual_art, Intramolecular force, Seaborgium, 540 Chemistry, Atom, visual_art.visual_art_medium, 570 Life sciences, biology
Abstract

In recent years gas-phase chemical studies assisted by physical pre-separation allowed for the investigation of fragile single molecular species by gas-phase chromatography. The latest success with the heaviest group 6 transactinide seaborgium is highlighted. The formation of a very volatile hexacarbonyl compound Sg(CO)6 was observed similarly to its lighter homologues molybdenum and tungsten. The interactions of these gaseous carbonyl complex compounds with quartz surfaces were investigated by thermochromatography. Second-generation experiments are under way to investigate the intramolecular bond between the central metal atom of the complexes and the ligands addressing the influence of relativistic effects in the heaviest compounds. Our contribution comprises some aspects of the ongoing challenging experiments as well as an outlook towards other interesting compounds related to volatile complex compounds in the gas phase.

Published
2016

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