N. Takahashi

Osaka University, Suika, Ōsaka, Japan

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Publications (433)688.28 Total impact

  • N Takahashi · Y Kasamatsu · N Kado · S Kuji · A Tanaka · M Abe · M Takekuma · Y Hirashima ·

    Journal of Minimally Invasive Gynecology 11/2015; 22(6):S203. DOI:10.1016/j.jmig.2015.08.734 · 1.83 Impact Factor
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    ABSTRACT: The production cross sections of 10Be and 26Al were measured by accelerator mass spectrometry using 89Y, 159Tb, and natCu targets bombarded by protons with energies Ep of 120 GeV and 392 MeV. The production cross sections obtained for 10Be and 26Al were compared with those previously reported using Ep = 50 MeV-24 GeV and various targets. It was found that the production cross sections of 10Be monotonically increased with increasing target mass number when the proton energy was greater than a few GeV. On the other hand, it was also found that the production cross sections of 10Be decreased as the target mass number increased from that of carbon to those near the mass numbers of nickel and zinc when the proton energy was below approximately 1 GeV. They also increased as the target mass number increased from near those of nickel and zinc to that of bismuth, in the same proton energy range. Similar results were observed in the production cross sections of 26Al, though the absolute values were quite different between 10Be and 26Al. The difference between these production cross sections may depend on the impact parameter (nuclear radius) and/or the target nucleus stiffness.
    Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms 08/2015; 361. DOI:10.1016/j.nimb.2015.08.001 · 1.12 Impact Factor
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    ABSTRACT: Japan is prone to great earthquakes because of its position near two different subduction zones. The Philippine Sea plate subducts from the southeast, and the Pacific plate subducts from the east. The former was the source of a series of great earthquakes, of which the Tonankai earthquake of 1944 and the Nankaido earthquake of 1946 are the latest events. The latter was the source of the 2011 earthquake off the Pacific coast of Tohoku (Tohoku earthquake) of 11 March 2011 (M9).
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    ABSTRACT: Onboard calibration method of the Dual-frequency Precipitation Radar (DPR) installed on the Global Precipitation Measurement (GPM) core observatory, launched in February 2014, is described. The orbital check out status of DPR will be reported.
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    ABSTRACT: Solvent extraction of macro amounts of Mo(V) and Mo(VI) from HCl using Aliquat 336 in chloroform was performed for the electrochemistry of Sg. The extraction reaction attained equilibrium with a shaking time of 10 s in higher than 8 M HCl. The D values of Mo(V) obtained by the electrochemical reduction of Mo(VI) were in good agreement with those obtained by the extraction of MoCl5, and the D values of Mo(V) were higher than those of Mo(VI). These results suggested that the reduction behavior of Sg might be studied by electrochemical reduction combined with the present solvent extraction.
    Journal of Radioanalytical and Nuclear Chemistry 09/2014; 301(3):751-756. DOI:10.1007/s10967-014-3208-9 · 1.03 Impact Factor
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    ABSTRACT: Reaction cross sections for Cr and Y induced by neutrons at 197 MeV were measured by using 7Li(p,n) reaction at N0 beam line in the Research Center for Nuclear Physics (RCNP), Osaka University. To estimate quasi-monoenergetic neutron cross sections, Cr and Y samples were irradiated on the two angles of 0∘ and 25∘ relative to the axis of the primary proton beam. The measured cross section data in the natCr(n,x) and 89Y(n,x) reactions are compared to the JENDL high-energy file and the literature proton values, respectively. The results obtained are also compared to the cross section data for the same target materials with 287 and 386 MeV neutrons in our previous work.
    Nuclear Data Sheets 05/2014; 119:197-200. DOI:10.1016/j.nds.2014.08.055 · 4.57 Impact Factor
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    ABSTRACT: We performed solvent extraction of Mo-99 and W-181 from HCl and HCl/LiCl solutions into Aliquat 336-chloroform solutions. It is found that the extracted anionic species of Mo and W have a net charge of -1 from the logD versus log[Aliquat 336] plots. At high H3O+ concentrations, the D values in HCl were lower than those in HCl/LiCl, probably because of the protonation of anionic Mo and W species in HCl. The D values of Mo were significantly higher than those of W, suggesting that the extracted Mo and W species are different from each other and/or have different stabilities in HCl.
    Journal of Radioanalytical and Nuclear Chemistry 02/2014; 303(2):1091-1094. DOI:10.1007/s10967-014-3449-7 · 1.03 Impact Factor
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    ABSTRACT: We studied solid–liquid extraction behavior of carrier-free Mo and W radiotracers onto an Aliquat 336-loaded resin from HCl solutions toward extraction chromatography experiments of element 106, seaborgium (Sg). Distribution coefficients (K d) of Mo and W on the resin were determined as a function of HCl concentration by a batch method. On-line extraction chromatography of Mo and W was also carried out in 2–8 M HCl solutions with an automated rapid chemistry apparatus. The order of extraction probability from 2 to 8 M HCl was Mo > W, which reflected the order of the K d values in the batch experiment.
    Journal of Radioanalytical and Nuclear Chemistry 02/2014; 303(2):1385-1388. DOI:10.1007/s10967-014-3476-4 · 1.03 Impact Factor
  • S. Ueno · K. Toda · A. Asano · N. Takahashi · Y. Kasamatsu · T. Yokokita · A. Yokoyama ·
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    ABSTRACT: To obtain a better understanding of the fusion reaction, we have focused on reactions involving deformed nuclei. Evaporation residue cross sections of the Tm-169+Ne-20 reaction were measured, from which we extracted the fusion excitation function. This is compared with literature data of the Tm-169+O-16 and Ho-165+Ne-20 systems. Irradiation with Ne-20 ion beam has been carried out at the incident energy near the Coulomb barrier, where the effect of nuclear deformation is prominent. The results are consistent with the idea that the degree of deformation has an effect on the threshold value of the excitation functions near the Coulomb barrier.
    Journal of Radioanalytical and Nuclear Chemistry 02/2014; 303(2):1273-1276. DOI:10.1007/s10967-014-3632-x · 1.03 Impact Factor
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    ABSTRACT: Neutron activation cross sections for Bi and Co at 386 MeV were measured by activation method. A quasi-monoenergetic neutron beam was produced using the 7Li(p,n) reaction. The energy spectrum of these neutrons has a high-energy peak (386 MeV) and a low-energy tail. Two neutron beams, 0° and 25° from the proton beam axis, were used for sample irradiation, enabling a correction for the contribution of the low-energy neutrons. The neutron-induced activation cross sections were estimated by subtracting the reaction rates of irradiated samples for 25° irradiation from those of 0° irradiation. The measured cross sections were compared with the findings of other studies, evaluated in relation to nuclear data files and the calculated data by Particle and Heavy Ion Transport code System code.
    Radiation Protection Dosimetry 12/2013; 161(1-4). DOI:10.1093/rpd/nct334 · 0.91 Impact Factor
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    ABSTRACT: For the solvent extraction experiment on element 104 (Rf), solvent extraction of Zr and Hf as its homologues was performed in tributylphosphate (TBP)/hydrochloric acid (HCl) system using the carrier-free radiotracers 88Zr and 175Hf. Time dependences of the distribution ratios of Zr and Hf were investigated using 6.1 and 10.0M HCl and 0.5 and 2.0M TBP benzene solutions. The distribution ratios in equilibrium were determined for these elements as a function of HCl concentrations in the range of 4.1-10.2M. We found that the neutral chloride complexes of Zr and Hf were formed and extracted into the organic phase within 20 min in HCl with a concentration higher than 6 M. From the results, we propose that solvent extraction of Rf from 4-8M HCl into 2.0M TBP benzene is suitable for investigating the chloride complexation properties of Rf. In addition, for the development of the rapid liquid-liquid extraction apparatus, three types of microchannel devices, namely, a micro reactor, capillary tube and micro-chemical chip, were tested as a mixing-solution part in the apparatus. The chemical reactions of Zr and Hf in the extraction were found to be fast only when using the microchemical chip, which is important for investigations with the 68-s 261Rf.
    07/2013; 101(8):130715000408008. DOI:10.1524/ract.2013.2056
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    ABSTRACT: In the present paper we consider neutrino events due to quasi-elastic scattering (QEL) as the most reliable events among various candidate events to be analyzed, and have carried out the first step of an L/E analysis which aims to confirm the survival probability with a Numerical Computer Experiment. The most important factor in the survival probability is Lnu and Enu, but this cannot be measured for such neutral particles. Instead, Lmu and Emu is utilized in the L/E analysis, where Lnu, Lmu, Enu and Emu denote the flight path lengths of the incident neutrinos, those of the emitted leptons, the energies of the incident neutrinos and those of the emitted leptons, respectively. According to our Computer Numerical Experiment, the relation of Lnu/Enu is nearly equal to Lmu/Emu doesn't hold. In subsequent papers, we show the results on an L/E analysis with the Computer Numerical Experiment based on our results obtained in the present paper.
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    ABSTRACT: Excited states in 17C were investigated through the measurement of beta?-delayed neutrons and gamma rays emitted in the ? decay of 17B. In the measurement, three negative-parity states and two inconclusive states, were identified in 17C above the neutron threshold energy, and seven gamma-lines were identified in a beta?-delayed multiple neutron emission of the 17B ? decay. From these transitions, the beta?-decay scheme of 17B was determined. In the present work, the ?beta-NMR technique is combined with the ?-delayed particle measurements using a fragmentation-induced spin-polarized 17B beam. This new scheme allows us to determine the spin parity of beta?-decay feeding excited states based on the difference in the discrete ?beta-decay asymmetry parameters, provided the states are connected through the Gamow-Teller transition. In this work, 1/2-, 3/2-, and (5/2-) are assigned to the observed states at Ex = 2.71(2), 3.93(2), and 4.05(2) MeV in 17C, respectively.
    Physical Review C 01/2013; 87(3). DOI:10.1103/PhysRevC.87.034316 · 3.73 Impact Factor
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    ABSTRACT: The production cross sections of 10Be, 26Al and 36Cl produced from Cu and Y targets irradiated with 300 MeV protons were measured by accelerator mass spectrometry. Using these cross section values in conjunction with those of the spallation products we confirm that nuclear fragmentation contributes to production of 10Be in the 300 MeV proton-induced reactions for Cu and Y. These cross sections obtained are compared to cross sections of 10Be, 26Al and 36Cl from 300 MeV proton-induced reactions for other target elements. We also confirm that the cross section values of 10Be and 36Cl for Cu and Y are consistent with the tendency of those cross section values to decrease with increasing target mass.
    Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms 01/2013; 294:475–478. DOI:10.1016/j.nimb.2012.03.005 · 1.12 Impact Factor
  • N. Takahashi · T. Baba · M. Takaesu · S. Kamiya · K. Kawaguchi · Y. Kaneda ·
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    ABSTRACT: We have developed ocean floor network cable system in view of scientific and technical aspects. Japan Agency for Marine-Earth Science and Technology (JAMSTEC) already deployed a dense ocean floor network system (DONET) in the Tonankai earthquake rupture area and new one named by DONET2 in the Nankai earthquake rupture area. These earthquakes have repeatedly occurred, had tormented people living the coastal area, and suffered great damages of their strong motions and tsunami. These systems have to contribute to early detection of earthquakes and tsunamis, understanding source mechanisms of earthquakes and tsunamis, damage reduction of the coastal areas. In addition, they have to work continuously for long years even if huge earthquakes occurs, because large earthquakes with magnitude of 8 has successively occurred and because large tsunamis have also attacked accompanied with the earthquakes. To prepare such issues, we have considered in various point of views. Here we introduce such various points to set ocean floor network system and implement them.
    Underwater Technology Symposium (UT), 2013 IEEE International; 01/2013
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    ABSTRACT: DONET is a flexible and expandable submarine cabled seafloor observation infrastructure for mega-thrust earthquake research and disaster prevention. The system which consists of a backbone looped submarine cable system, five science nodes and 20 set of state of art earthquake and tsunami observatories was developed and constructed in the program started from 2006 and fully in operation from 2011 at the hypothesis region of To-Nankai earthquake. Simultaneously with the construction of original DONET, the development and deployment of second DONET system (DONET2) was planned and started in 2010 to subject for the hypothesis region of Nankai earthquake. Since this region spreads out in the wide area about 2 times rather than the region of the To-Nankai earthquake, deployment of a large-scale observation network system is required. Expansion of scale of observatory means the increase of power distribution capacity and the confliction of network topology, it will need to solve the several engineering subject to expand the design of original DONET to large scale system DONET2. This paper describe several indispensable technologies of submarine cabled seafloor observation system DONET (power consumption control, power blanching and time synchronization), then introduce the novel engineering approach for high voltage power distribution control and large scale network topology management for DONET2 off Kii channel observatory network.
    Underwater Technology Symposium (UT), 2013 IEEE International; 01/2013
  • T. Baba · N. Takahashi · Y. Kaneda ·
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    ABSTRACT: We investigated correlation between coastal and offshore tsunami height for our observational array of ocean-bottom pressure gauges, DONET, in the Nankai trough. But it is not easy to know correct sea surface fluctuation generated from near-field earthquakes in static bottom pressure changes. This is because the seafloor is simultaneously displaced in case of great near-field earthquakes occurred. In order to avoid the problem, we made the averaged waveforms of the absolute values of ocean-bottom pressure fluctuations during tsunami. Many tsunami calculations were executed by changing slip models on the plate interface. We checked the correlation between the average absolute of ocean bottom pressure and tsunami height at the coast. A clear correlation can be seen between the two values. This result indicates a possibility of more accurate real-time predicting of tsunami height by using arrayed ocean-bottom pressure gauge data.
    Underwater Technology Symposium (UT), 2013 IEEE International; 01/2013
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    ABSTRACT: In the near future the energy region above few hundreds of TeV may really be accessible for measurements of the atmospheric muon spectrum by the IceCube array. Therefore one expects that muon flux uncertainties above 50 TeV, related to a poor knowledge of charm production cross sections and insufficiently examined primary spectra and compo-sition, will be diminished. We present predictions for the very high-energy muon spectrum at sea level, obtained with the three hadronic interaction models, taking into account also the muon contribution due to decays of charmed hadrons.
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    Y. Okumura · N. Takahashi · A. Misaki ·
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    ABSTRACT: Lipari and Stanev developed a method for range fluctuation of high energy muons, stressing the importance of accounting for the fluctuations of the energy loss in radiative processes in 1991 and, now, their method has become the basement for the energy determination of high energy muons through the measurement of the Cherenkov light yields due to those muons in KM3 physics. Once, Takahashi et al developed a method for the investigation on the depth intensity relation of high energy muons in which all the stochastic processes concerned are taken into account exactly (1983). Now, we make the method by Takahashi et al. revival for the same purpose of the application to the analysis of future KM3 physics. In the present paper, our concern is restricted to the introduction to the fundamental of our method and some subsequent results thereby in which the real simulated behaviors of high energy muons from $10^{12}$eV to $10^{18}$eV, the survival probabilities of high energy and so on are included. The discussion around the practical application of our method to the KM3 physics is entrusted in the subsequent papers. As for as the survival probability of high energy muons is concerned, our method gives nearly the same results to Lipari and Stanev's in some regions and gives the deviated results from theirs in another ones. Thus, we examine the application limit of their method and clarify the reason why, comparing with our method. The most distinct difference in the both methods may become apparent in the treatment on the Cherenkov light yields spectrum by which one may estimate the energies of the muons concerned. We will mention to them in subsequent papers.
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    ABSTRACT: The Earth, Clouds, Aerosols and Radiation Explorer (EarthCARE) mission is joint mission between Europe and Japan for the launch year of 2015. Mission objective is to improve scientific understanding of cloud-aerosol-radiation interactions that is one of the biggest uncertain factors for numerical climate and weather predictions. The EarthCARE spacecraft equips four instruments such as an ultra violet lidar (ATLID), a cloud profiling radar (CPR), a broadband radiometer (BBR), and a multi-spectral imager (MSI) to observe aerosols, clouds and their interactions simultaneously from the orbit. Japan aerospace exploration agency (JAXA) is responsible for development of the CPR that will be the first space-borne W-band Doppler radar. The CPR is defined with minimum radar sensitivity of -35dBz, radiometric accuracy of 2.7 dB, and Doppler velocity measurement accuracy of 1m/s. These specifications require highly accurate pointing technique in orbit and high power source with large antenna dish. JAXA and National Institute of Information and Communications Technology (NICT) have been jointly developed this CPR to meet these requirements. In addition, new ground calibration technique is also being progressed for the launch of EarthCARE/CPR. This evaluation method will also be the first use for spacecraft as well as Doppler cloud radar. This paper shows the summary of the CPR design and verification status, and activity status of development of ground calibration method with a few results of experiment using current space-borne cloud radar (CloudSat, NASA).
    Proceedings of SPIE - The International Society for Optical Engineering 09/2012; DOI:10.1117/12.974479 · 0.20 Impact Factor

Publication Stats

5k Citations
688.28 Total Impact Points


  • 1977-2015
    • Osaka University
      • • Department of Physics
      • • Department of Chemistry
      • • Research Center for Nuclear Physics
      • • Department of Internal Medicine
      • • Laboratory of Nuclear Studies
      Suika, Ōsaka, Japan
  • 2002-2013
    • Japan Agency for Marine-Earth Science Technology
      • Institute for Research on Earth Evolution
      Yokohama, Kanagawa, Japan
    • Niigata University
      • Division of Clinical Nephrology and Rheumatology
      Niahi-niigata, Niigata, Japan
  • 2007-2012
    • National Institute of Information and Communications Technology
      Edo, Tōkyō, Japan
    • University of Fukui
      • Division of Nephrology
      Фукуй, Fukui, Japan
  • 1998-2011
    • Hirosaki University
      • • Department of Advanced Physics
      • • Department of Science Radiological Technology
      • • Faculty of Science and Technology
      Khirosaki, Aomori Prefecture, Japan
    • Yamagata University
      • First Department of Internal Medicine
      Ямагата, Yamagata, Japan
  • 2008
    • Okayama University
      • Department of Physics
      Okayama, Okayama, Japan
  • 2007-2008
    • Fukui University of Technology
      Hukui, Fukui, Japan
  • 1988-2008
    • Kansai Medical University
      • Second Department of Internal Medicine
      Moriguchi, Ōsaka, Japan
  • 2003-2007
    • Morinaga Milk Industry Co., Ltd.
      Edo, Tokyo, Japan
  • 2000-2006
    • Shizuoka University
      • • Faculty of Engineering
      • • Department of Electronics and Materials Science
      Hamamatsu, Shizuoka-ken, Japan
  • 1994-2006
    • Tohoku University
      • • Graduate School of Agricultural Science
      • • Division of Internal Medicine
      • • Division of Cell Biology
  • 2005
    • Osaka Prefecture University
      Sakai, Ōsaka, Japan
  • 2003-2004
    • Stanford University
      • Department of Geophysics
      Palo Alto, California, United States
  • 1999
    • Sendai Shirayuri Women's College
      Sendai, Kagoshima, Japan
  • 1997
    • Kagawa University
      • School of Medicine
      Takamatu, Kagawa, Japan
  • 1995
    • Sharp Corporation
      Ōsaka, Ōsaka, Japan
  • 1994-1995
    • Tokyo University of Agriculture and Technology
      • Division of Applied Chemistry
      Edo, Tōkyō, Japan
  • 1990-1992
    • Nagai Internal Medicine Clinic
      Okayama, Okayama, Japan
  • 1975-1988
    • The University of Tokyo
      • Department of Physics
      Tōkyō, Japan
  • 1981-1985
    • Texas A&M University
      College Station, Texas, United States