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Journal Articles

Sequence-dependent hydration water dynamics of dodecameric DNA

Nakagawa, Hiroshi; Yonetani, Yoshiteru*; Nakajima, Kenji; Kawamura, Seiko; Kikuchi, Tatsuya*; Inamura, Yasuhiro; Kataoka, Mikio*; Kono, Hidetoshi*

JPS Conference Proceedings (Internet), 33, p.011101_1 - 011101_6, 2021/03

Hydration water dynamics were measured by quasi-elastic neutron scattering with Hn$$_{2}$$O/D$$_{2}$$O contrast for two DNA dodecamers, 5'CGCG$$underline{rm AATT}$$CGCG'3 and 5'CGCG$$underline{rm TTAA}$$CGCG'3, which have been computationally shown to be structurally rigid and flexible, respectively. The dynamical transitions of the hydration water as well as DNA were observed for both sequences at approximately 240 K. Above the transition temperature, the mean square displacements of the hydration water for the rigid sequence were smaller than those for the flexible one. Furthermore, the relaxation time of the hydration water was longer in the rigid DNA than in the flexible DNA. We suggest that hydration water dynamics on the picosecond timescale are associated with sequence-dependent deformability of DNA.

Journal Articles

Analysis of the activities of the website "Question and Answer about radiation in Daily Life" after the accident at the Fukushima Daiichi Nuclear Power Station and some lessons learned from it; To pass on this experience to the future

Kono, Takahiko; Shimo, Michikuni*; Hayakawa, Hironobu*; Taniguchi, Kazufumi*; Tanaka, Masato*; Tanaka, Hitomi*; Onoue, Yosuke*; Nagaya, Hiroshi*; Torii, Hiroyuki*; Uno, Kazuko*

Hoken Butsuri (Internet), 55(4), p.226 - 238, 2020/12

After the accident at the Fukushima Daiichi Nuclear Power Station, artificial radionuclides such as radioactive cesium and iodine were released into the environment. It caused great anxiety not only in the vicinity of the Fukushima Daiichi Nuclear Power Station but also in other regions of Japan. Some members of the Japan Health Physics Society (JHPS) which is a leading academic society in Japan in the field of radiation protection volunteered to establish the website called "Question and Answer about radiation in Daily Life" just after the accident to reduce the anxiety of the residents about the health effects of radiation. After that, Committee of "Question and Answer about radiation in Daily Life" was established in August 2011 in JHPS, and this activity had been carried out under the responsibility of the society that answered with sincerity against questions from the public as specialists until February 2013. The number of questions on the website had gradually decreased as time passed; therefore, the Committee members decided to end these activities in February 2013. In this paper, following contents were shown; the activities of the Q&A website for about two years, the issues of the stance on our activities, the information related to the website activities and the analysis of Twitter data. Based on the experience and the knowledge obtained from these activities, the issues and experiences that can be utilized in the initial response to emergencies for radiation protection experts as well as other fields are presented.

Journal Articles

Development of a code system DEURACS for theoretical analysis and prediction of deuteron-induced reactions

Nakayama, Shinsuke; Kono, Hiroshi*; Watanabe, Yukinobu*; Iwamoto, Osamu; Ye, T.*; Ogata, Kazuyuki*

EPJ Web of Conferences, 146, p.12025_1 - 12025_4, 2017/09

 Times Cited Count:3 Percentile:92.06

Recently, intensive neutron sources using deuteron accelerator have been proposed for various applications. Accurate and comprehensive deuteron nuclear data library over wide ranges of target mass number and incident energy are indispensable for the design of deuteron accelerator neutron sources. Thus, we have developed an integrated code system dedicated for analysis and prediction of deuteron-induced reactions, which is called DEUteron-induced Reaction Analysis Code System (DEURACS). In the present work, the analysis of $$(d,xn)$$ reactions is extended to higher incident energy up to nearly 100 MeV and also DEURACS is applied to $$(d,xd)$$ reactions at 80 and 100 MeV. The DEURACS calculations reproduce the experimental double-differential cross sections for the $$(d,xn)$$ and $$(d,xd)$$ reactions well.

Journal Articles

Analysis of $$(d,xn)$$ reactions on $$^{9}$$Be and $$^{12}$$C

Nakayama, Shinsuke; Kono, Hiroshi*; Watanabe, Yukinobu*; Iwamoto, Osamu; Ogata, Kazuyuki*

RCNP Annual Report 2016 (Internet), 2 Pages, 2017/05

We are conducting a theoretical research on deuteron-induced reaction together with Kyushu University and Research Center for Nuclear Physics (RCNP) of Osaka University. The research outcomes achieved in fiscal year 2016 are summarized as a part of the annual report of RCNP. In recent years, accelerator neutron sources using $$(d,xn)$$ reactions on light nuclei (Li, Be, C, etc.) are proposed for applications in various fields. Engineering design of such facilities requires accurate prediction of $$(d,xn)$$ reactions on light nuclei in a wide incident energy range. Therefore, we have developed a physics-based computational code system dedicated for deuteron-induced reactions, called DEURACS. In fiscal year 2016, we calculated double-differential neutron yields from deuteron bombardment on thick $$^{9}$$Be and $$^{12}$$C targets, and the calculation reproduced the experimental data quantitatively well in the incident energy range up to 50 MeV. From the results, it has been found that DEURACS can accurately predict $$(d,xn)$$ reactions on light nuclei in a wide incident energy range. In addition, component-by-component analysis has revealed that the nonelastic breakup reactions make the most dominant contribution to neutron production.

Journal Articles

Theoretical model analysis of $$(d,xn)$$ reactions on beryllium

Kono, Hiroshi*; Watanabe, Yukinobu*; Nakayama, Shinsuke; Iwamoto, Osamu; Ye, T.*; Ogata, Kazuyuki*

JAEA-Conf 2016-004, p.165 - 170, 2016/09

For engineering design of deuteron accelerator neutron sources, accurate nuclear data of deuteron-induced reactions on neutron converter (Li, Be, C, etc.) and accelerator structure material (Fe, Cr, Ni, etc.) are indispensable. Therefore we have developed a computational code system based on physics models dedicated for deuteron nuclear data evaluation. In the present study, we have analyzed the $$(d,xn)$$ reactions on beryllium at incident deuteron energies up to 65 MeV. Since there is a lot of experimental Thick Target Neutron Yields (TTNYs), double-differential $$(d,xn)$$ cross sections are calculated by the code system and then are converted to TTNYs. It is found that the calculated TTNYs reproduce the experimental ones fairly well except in the low neutron energy region.

Journal Articles

Theoretical model analysis of $$(d,xn)$$ reactions on $$^9$$Be and $$^{12}$$C at incident energies up to 50 MeV

Nakayama, Shinsuke; Kono, Hiroshi*; Watanabe, Yukinobu*; Iwamoto, Osamu; Ogata, Kazuyuki*

Physical Review C, 94(1), p.014618_1 - 014618_9, 2016/07

 Times Cited Count:22 Percentile:88.15(Physics, Nuclear)

Double-differential thick target neutron yields (TTNYs) from deuteron bombardment on thick Be and C targets are analyzed using the DEURACS (DEUteron-induced Reaction Analysis Code System). The calculated TTNYs reproduced the experimental ones quantitatively well in the incident energy range up to 50 MeV. In addition, it was found that the proton stripping reaction makes the most dominant contribution to neutron production. From the analysis, we conclude that the DEURACS is applicable to $$(d,xn)$$ reactions and modeling of the stripping reaction is essential to predict neutron production yields accurately.

Journal Articles

Modelling and analysis of nucleon emission from deuteron-induced reactions at incident energies up to 100 MeV

Nakayama, Shinsuke; Kono, Hiroshi*; Watanabe, Yukinobu*; Iwamoto, Osamu; Ye, T.*; Ogata, Kazuyuki*

EPJ Web of Conferences, 122, p.04004_1 - 04004_9, 2016/06

 Times Cited Count:4 Percentile:88.52

In recent years, accelerator neutron sources using deuteron-induced reactions on $$^7$$Li, $$^9$$Be, $$^{12}$$C, etc., are proposed for applications in various fields. Engineering design of such facilities requires deuteron nuclear data in a broad incident energy range. We have developed a computational code system dedicated for deuteron nuclear data evaluation in combination with some theoretical models. The code system has been applied to analyses of double-differential $$(d,xp)$$ cross sections for $$^{12}$$C, $$^{27}$$Al, and $$^{58}$$Ni at incident energies up to 100 MeV. On the other hand, there is few experimental double-differential $$(d,xn)$$ cross sections. Therefore, double-differential thick target neutron yields for light nuclei such as $$^9$$Be and $$^{12}$$C are calculated and compared with experimental data. The presentation will show the validation result of the present modelling for nucleon emissions from deuteron-induced reactions through comparison with available experimental data.

Journal Articles

Shape elongation of embedded Zn nanoparticles induced by swift heavy ion irradiation; A SAXS study

Amekura, Hiroshi*; Kono, Kenichiro*; Okubo, Nariaki; Ishikawa, Norito

Physica Status Solidi (B), 252(1), p.165 - 169, 2015/01

 Times Cited Count:8 Percentile:37.86(Physics, Condensed Matter)

Zinc nanoparticles (NPs) of 10 nm in diameter were irradiated with 200 MeV Xe$$^{14+}$$ ions with various fluences. The shape elongation of the NPs and the mean inter-particle (IP) distance were evaluated by small angle X-ray scattering (SAXS) in the transmission configuration using synchrotron X-ray of 18 keV. The azimuth angle dependence of SAXS signal, which was isotropic for unirradiated state, changed to anisotropic. It indicated that the NPs collectively deformed from spheres to spheroids.

Journal Articles

Local dynamics coupled to hydration water determines DNA-sequence-dependent deformability

Nakagawa, Hiroshi; Yonetani, Yoshiteru; Nakajima, Kenji; Kawamura, Seiko; Kikuchi, Tatsuya; Inamura, Yasuhiro; Kataoka, Mikio; Kono, Hidetoshi

Physical Review E, 90(2), p.022723_1 - 022723_11, 2014/08

 Times Cited Count:7 Percentile:50.1(Physics, Fluids & Plasmas)

Molecular dynamics (MD) simulations and Quasi-Elastic Neutron Scattering (QENS) experiments were conducted on hydrated two DNA dodecamers with distinct deformability; 5'CGCGAATTCGCG3' and 5'CGCGTTAACGCG3'. The former is known to be rigid and the latter to be flexible. The mean-square displacements (MSDs) of DNA dodecamers exhibit so-called dynamical transition around 200-240 K for both sequences. To investigate the DNA sequence dependent dynamics, the dynamics of DNA and hydration water above the transition temperature were examined using both MD simulations and QENS experiments. The fluctuation amplitude of the AATT central tetramer is smaller, and its relaxation time is longer, than that observed in TTAA, suggesting that the AT step is kinetically more stable than TA. The sequence-dependent local base pair step dynamics correlate with the kinetics of breaking the hydrogen bond between DNA and hydration water. The sequence dependent DNA base pair step fluctuations appear above the dynamical transition temperature. Together with these results, we conclude that DNA deformability is related to the local dynamics of base pair step, themselves coupled to hydration water in the minor groove.

Journal Articles

Journal Articles

The Report of OECD/NEA CRPPH EGIR Satellite Meeting in Tokyo

Ogino, Haruyuki*; Yoshitomi, Hiroshi; Kono, Takahiko

Hoken Butsuri, 45(2), p.131 - 136, 2010/06

no abstracts in English

Journal Articles

Mechanical properties of weldments using irradiated stainless steel welded by the laser method for ITER blanket replacement

Yamada, Hirokazu*; Kawamura, Hiroshi; Nagao, Yoshiharu; Takada, Fumiki; Kono, Wataru*

Journal of Nuclear Materials, 355(1-3), p.119 - 123, 2006/09

 Times Cited Count:3 Percentile:25.6(Materials Science, Multidisciplinary)

In this study, the bending properties of welding joint of irradiated material and un-irradiated material (irradiated/un-irradiated joints) were investigated using SS316LN-IG, which is the candidate material for the cooling pipe of ITER. The results of this study showed that the bending position of joints using un-irradiated material was un-irradiated part and that the bending position of irradiated/irradiated joints was fusion area or HAZ (heat affected zone). Although the bending position of joints was different bor the combination pattern between irradiated and un-irradiated materials, the bending strength of joint was almost same. Additionally, it is confirmed that bending strength did not depend on the combination pattern between the irradiated and un-irradiated materials, nor on the relationship between the heat input direction and the bending load direction.

Journal Articles

Post-irradiation examination of high burnup HBWR fuel rods at JAERI

Nakamura, Jinichi; Uetsuka, Hiroshi; Kono, Nobuaki; ; ; Furuta, Teruo

HPR-345 (Vol. II), 0, 13 Pages, 1995/00

no abstracts in English

JAEA Reports

None

Yokoyama, Hiroomi*; Kanazawa, Toshio*; Fukuma, Tadashi*; Tamekiyo, Kozo*; Yanagida, Koji*; Furuya, Takashi*; Kono, Hiroshi*; Ito, Keiji*; Shirakura, Takao*; Kashiwara, Shinichiro*; et al.

PNC TN8410 87-086VOL2, 944 Pages, 1986/09

PNC-TN8410-87-086VOL2.pdf:32.16MB

JAEA Reports

Detailed design of new material nitric acid recovery evaporator

Yokoyama, Hiroomi*; Kanazawa, Toshio*; Fukuma, Tadashi*; Tamekiyo, Kozo*; Yanagida, Koji*; Furuya, Takashi*; Kono, Hiroshi*; Ito, Keiji*; Shirakura, Takao*; Kashiwara, Shinichiro*; et al.

PNC TN8410 87-086VOL1, 1037 Pages, 1986/09

PNC-TN8410-87-086VOL1.pdf:34.39MB

A detailed design for a New Material Nitric Acid Recovery Evaporator was carried out with a plan to use it to replace an already constructed stainless steel Nitric Acid Recovery Evaporator at the Power Reactor and Nuclear Fuel Development Corporation's Tokai Works. Most of the original Evaporator's conditions such as compliance with applicable laws, standards, structure, treatment performance and operating conditions were maintained when designing the new machine. The material is titanium with the addition of 5% tantalum. The Evaporator was designed with an operational life expectance of 10 years. We have calculated that the new Evaporator will have sufficient strength (including a seismatic design) and have the same evaporative performance as the already constructed one. During design, we referred to the results of already completed basic designs (Phase 1) of New Material Nitric Acid Recovery Evaporators, design and production of small-scale test equipment units, and the development of successful joints between different materials. We also considered manufacturing, installation, trial runs, maintenance, and the specifications for materials used for manufacturing, installation, piping and operation of the new Evaporator.

Oral presentation

Dynamics of DNA molecule studied by inelastic neutron scattering

Nakagawa, Hiroshi; Yonetani, Yoshiteru; Kono, Hidetoshi; Kataoka, Mikio; Nakajima, Kenji; Kawamura, Seiko; Kikuchi, Tatsuya; Inamura, Yasuhiro

no journal, , 

no abstracts in English

Oral presentation

Computer simulation analysis of sequence dependecies of DNA conformational dynamics and hydration

Yonetani, Yoshiteru; Nakagawa, Hiroshi; Kono, Hidetoshi

no journal, , 

no abstracts in English

Oral presentation

Relationship between hydration induced DNA dynamical transition and DNA-sequence dependent deformability

Nakagawa, Hiroshi; Yonetani, Yoshiteru; Nakajima, Kenji; Kawamura, Seiko; Kikuchi, Tatsuya; Inamura, Yasuhiro; Kataoka, Mikio; Kono, Hidetoshi

no journal, , 

Molecular dynamics simulations and inelastic neutron scattering experiments were conducted on two hydrated DNA dodecamers with distinct deformability; CGCGAATTCGCG and CGCGTTAACGCG. The mean-square displacements of both DNA dodecamers exhibit so-called dynamical transition around 200-240 K and hydration water also exhibits the abrupt increase in the mean-square displacement at the same temperature. The fluctuation amplitude of the central tetramer AATT is smaller, and its relaxation time longer, than that observed on TTAA, suggesting that the AT step is kinetically more stable than the TA step. The sequence dependent DNA base pair step fluctuations appear above the dynamical transition temperature. Therefore, we concluded that the hydration water induces the DNA dynamical transition, and this enhanced motion by hydration is related to the deformability of DNA structure.

Oral presentation

Theoretical model analysis of (d,xn) reactions on carbon

Kono, Hiroshi*; Nakayama, Shinsuke*; Watanabe, Yukinobu*; Iwamoto, Osamu; Ye, T.*; Ogata, Kazuyuki*

no journal, , 

To validate the theoretical model calculation for (d,xn) reaction, thick target neutron yield(TTNY) for deuteron induced reaction on carbon has been calculated. The calculation consists of three calculation codes of Glauber, CDCC and CCONE. The results reasonably reproduce the experimental TTNY data. The present framework seems to be usable except for low emission energy.

Oral presentation

Study of deuteron nuclear data for design of deuteron accelerator neutron sources, 3; Theoretical model analysis of neutron production in deuteron-induced reactions

Kono, Hiroshi*; Nakayama, Shinsuke*; Watanabe, Yukinobu*; Iwamoto, Osamu; Ye, T.*; Ogata, Kazuyuki*

no journal, , 

Nuclear data of deuteron induced reactions are necessary for development of neutron sources with deuteron accelerators. To evaluate deuteron nuclear data, a calculation code system with descriptions of reaction mechanism for deuteron induced reactions has been developed and its applicability to (d,xp) reactions has been demonstrated. In the present work, the code system has been applied to (d,xn) reactions to investigate the applicability by comparing with experimental data for thick target neutron yield(TTY) whose data are abundant. Calculated results agree with TTY experimental data for $$^{12}$$C(d,xn) reaction. The usability to the neutron productions was confirmed.

23 (Records 1-20 displayed on this page)