検索対象:     
報告書番号:
※ 半角英数字
 年 ~ 
 年
検索結果: 79 件中 1件目~20件目を表示

発表形式

Initialising ...

選択項目を絞り込む

掲載資料名

Initialising ...

発表会議名

Initialising ...

筆頭著者名

Initialising ...

キーワード

Initialising ...

使用言語

Initialising ...

発行年

Initialising ...

開催年

Initialising ...

選択した検索結果をダウンロード

論文

Competition between allowed and first-forbidden $$beta$$ decays of $$^{208}$$At and expansion of the $$^{208}$$Po level scheme

Brunet, M.*; Podoly$'a$k, Zs.*; Berry, T. A.*; Brown, B. A.*; Carroll, R. J.*; Lica, R.*; Sotty, Ch.*; Andreyev, A. N.; Borge, M. J. G.*; Cubiss, J. G.*; et al.

Physical Review C, 103(5), p.054327_1 - 054327_13, 2021/05

 被引用回数:1 パーセンタイル:74.98(Physics, Nuclear)

The structure of $$^{208}$$Po populated through the EC/$$beta^{+}$$ decay of $$^{208}$$At is investigated using $$gamma$$-ray spectroscopy at the ISOLDE Decay Station. The presented level scheme contains 27 new excited states and 43 new transitions, as well as a further 50 previously observed $$gamma$$ rays which have been (re)assigned a position. Through the analysis using the shell model calculations approximately half of the $$beta$$-decay strength of $$^{208}$$At is found to proceed via allowed decay and half via first-forbidden decay. The first-forbidden transitions predominantly populate core excited states at high excitation energies, which is qualitatively understood using shell model considerations.

論文

Review of Fukushima Daiichi Nuclear Power Station debris endstate location in OECD/NEA preparatory study on analysis of fuel debris (PreADES) project

仲吉 彬; Rempe, J. L.*; Barrachin, M.*; Bottomley, D.; Jacquemain, D.*; Journeau, C.*; Krasnov, V.; Lind, T.*; Lee, R.*; Marksberry, D.*; et al.

Nuclear Engineering and Design, 369, p.110857_1 - 110857_15, 2020/12

 被引用回数:0 パーセンタイル:0.33(Nuclear Science & Technology)

福島第一原子力発電所(1F)の各ユニットの燃料デブリの最終状態位置については、まだ多くは不明である。不確実性の低減に向けた最初のステップとして、OECD/NEAは、燃料デブリ分析予備的考察(PreADES)プロジェクトが立ち上げた。PreADESプロジェクトのタスク1の一環として、関連情報をレビューし、燃料デブリの状態の推定図の正確さを確認した。これは、将来の燃料デブリの分析を提案するための基礎となる。具体的にタスク1では2つのアクティビティを実施した。第一に、1Fでの廃止措置活動に資するTMI-2とチェルノブイリ原子力発電所4号機での重大事故の関連知識、プロトタイプ試験とホットセル試験の結果の知見を収集した。第二に、プラント情報とBSAFプロジェクトのシビアアクシデントコード分析からの関連知識が組み込まれている1F燃料デブリの原子炉内の状態に関する現状の推定図を見直した。この報告は、PreADESプロジェクトのタスク1の洞察に焦点を当て、1Fの将来の除染および廃止措置活動に情報を提供するだけでなく、シビアアクシデント研究、特にシビアアクシデントにより損傷した原子力サイトの長期管理に関する重要な視点を提供する。

論文

Main findings, remaining uncertainties and lessons learned from the OECD/NEA BSAF Project

Pellegrini, M.*; Herranz, L.*; Sonnenkalb, M.*; Lind, T.*; 丸山 結; Gauntt, R.*; Bixler, N.*; Morreale, A.*; Dolganov, K.*; Sevon, T.*; et al.

Nuclear Technology, 206(9), p.1449 - 1463, 2020/09

 被引用回数:11 パーセンタイル:98.02(Nuclear Science & Technology)

The OECD/NEA Benchmark Study at the Accident of Fukushima Daiichi Nuclear Power Station (BSAF) project, which started in 2012 and continued until 2018, was one of the earliest responses to the accident at Fukushima Daiichi. The project, divided into two phases addressed the investigation of the accident at Unit 1, 2 and 3 by Severe Accident (SA) codes until 500 h focusing on thermal-hydraulics, core relocation, Molten Corium Concrete Interaction (MCCI) and fission products release and transport. The objectives of BSAF were to make up plausible scenarios based primarily on SA forensic analysis, support the decommissioning and inform SA codes modeling. The analysis and comparison among the institutes have brought up vital insights regarding the accident progression identifying periods of core meltdown and relocation, Reactor Pressure Vessel (RPV) and Primary Containment Vessel (PCV) leakage/failure through the comparison of pressure, water level and CAMS signatures. The combination of code results and inspections (muon radiography, PCV inspection) has provided a picture of the current status of the debris distribution and plant status. All units present a large relocation of core materials and all of them present ex-vessel debris with Unit 1 and Unit 3 showing evidences of undergoing MCCI. Uncertainties have been identified in particular on the time and magnitude of events such as corium relocation in RPV and into cavity floor, RPV and PCV rupture events. Main uncertainties resulting from the project are the large and continuous MCCI progression predicted by basically all the SA codes and the leak pathways from RPV to PCV and PCV to reactor building and environment. The BSAF project represents a pioneering exercise which has set the basis and provided lessons learned not only for code improvement but also for the development of new related projects to investigate in detail further aspects of the Fukushima Daiichi accident.

論文

Origin of the large ferroelectric polarization enhancement under high pressure for multiferroic DyMnO$$_{3}$$ studied by polarized and unpolarized neutron diffraction

寺田 典樹*; Qureshi, N.*; Stunault, A.*; Enderle, M.*; Ouladdiaf, B.*; Colin, C. V.*; Khalyavin, D. D.*; Manuel, P.*; Orlandi, F.*; 宮原 慎*; et al.

Physical Review B, 102(8), p.085131_1 - 085131_7, 2020/08

 被引用回数:0 パーセンタイル:0(Materials Science, Multidisciplinary)

We have determined the magnetic structures in high pressure phase with the giant ferroelectric polarization in DyMnO$$_{3}$$. For Mn spins, the E-type magnetic ordering is stabilized above 4.0 GPa, which induces the giant ferroelectric polarization through the exchange striction effect. Furthermore, we have elucidate that the lattice distortion generated through the exchange striction for the Dy and Mn bonds can give the significant magnetic field enhancement of ferroelectric polarization in this system.

論文

The Joint evaluated fission and fusion nuclear data library, JEFF-3.3

Plompen, A. J. M.*; Cabellos, O.*; De Saint Jean, C.*; Fleming, M.*; Algora, A.*; Angelone, M.*; Archier, P.*; Bauge, E.*; Bersillon, O.*; Blokhin, A.*; et al.

European Physical Journal A, 56(7), p.181_1 - 181_108, 2020/07

 被引用回数:73 パーセンタイル:99.41(Physics, Nuclear)

本論文では、核分裂と核融合のための統合評価済み核データファイルのバージョン3.3(JEFF-3.3)について説明する。中性子との反応が重要な核種の$$^{235}$$U, $$^{238}$$U, $$^{239}$$Pu, $$^{241}$$Am, $$^{23}$$Na, $$^{59}$$Ni, Cr, Cu, Zr, Cd, Hf, Au, Pb, Biについて、新しい核データ評価結果を示す。JEFF-3.3には、核分裂収率, 即発核分裂スペクトル, 核分裂平均中性子発生数の新しいデータが含まれる。更に、放射崩壊, 熱中性子散乱, ガンマ線放出, 中性子による放射化, 遅発中性子, 照射損傷に関する新しいデータも含まれている。JEFF-3.3は、TENDLプロジェクトのファイルで補完しており、光子, 陽子, 重陽子, 三重陽子, $$^{3}$$He核, アルファ粒子による反応ライブラリについては、TENDL-2017から採用した。また、不確かさの定量化に対する要求の高まりから、多くの共分散データが新しく追加された。JEFF-3.3を用いた解析の結果と臨界性, 遅発中性子割合, 遮蔽, 崩壊熱に対するベンチマーク実験の結果を比較することにより、JEFF-3.3は幅広い原子核技術の応用分野、特に原子力エネルギーの分野において優れた性能を持っていることが分かった。

論文

Clades of huge phages from across Earth's ecosystems

Al-Shayeb, B.*; Sachdeva, R.*; Chen, L.-X.*; Ward, F.*; Munk, P.*; Devoto, A.*; Castelle, C. J.*; Olm, M. R.*; Bouma-Gregson, K.*; 天野 由記; et al.

Nature, 578(7795), p.425 - 431, 2020/02

 被引用回数:83 パーセンタイル:99.63(Multidisciplinary Sciences)

Phage typically have small genomes and depend on their bacterial hosts for replication. We generated metagenomic datasets from many diverse ecosystems and reconstructed hundreds of huge phage genomes, between 200 kbp and 716 kbp in length. Thirty four genomes were manually curated to completion, including the largest phage genomes yet reported. Expanded genetic repertoires include diverse and new CRISPR-Cas systems, tRNAs, tRNA synthetases, tRNA modification enzymes, initiation and elongation factors and ribosomal proteins. Phage CRISPR have the capacity to silence host transcription factors and translational genes, potentially as part of a larger interaction network that intercepts translation to redirect biosynthesis to phage-encoded functions. Some phage repurpose bacterial systems for phage-defense to eliminate competing phage. We phylogenetically define seven major clades of huge phage from human and other animal microbiomes, oceans, lakes, sediments, soils and the built environment. We conclude that large gene inventories reflect a conserved biological strategy, observed across a broad bacterial host range and resulting in the distribution of huge phage across Earth's ecosystems.

論文

Ultralow thermal conductivity from transverse acoustic phonon suppression in distorted crystalline $$alpha$$-MgAgSb

Li, X.*; Liu, P.-F.*; Zhao, E.*; Zhang, Z.*; Guide, T.*; Le, M. D.*; Avdeev, M.*; 池田 一貴*; 大友 季哉*; 古府 麻衣子; et al.

Nature Communications (Internet), 11(1), p.942_1 - 942_9, 2020/02

 被引用回数:15 パーセンタイル:93.25(Multidisciplinary Sciences)

高性能の熱電材料実現には低熱伝導率が必要であり、その機構としてはフォノンの非調和によるもの、あるいは、結晶構造の動的な乱れによるフォノンの散乱によるものがあげられ、どちらも中性子散乱でその現象が明らかにされている。我々は中性子散乱と第一原理計算を組み合わせ、$$alpha$$-MgAgSbにおいて、静的な結晶構造の乱れとフォノンの非調和性が組み合わされて極端に低い熱伝導率が実現されているということを見いだしたので、これを報告する。

論文

IRDFF-II; A New neutron metrology library

Trkov, A.*; Griffin, P. J.*; Simakov, S. P.*; Greenwood, L. R.*; Zolotarev, K. I.*; Capote, R.*; Aldama, D. L.*; Chechev, V.*; Destouches, C.*; Kahler, A. C.*; et al.

Nuclear Data Sheets, 163, p.1 - 108, 2020/01

 被引用回数:23 パーセンタイル:99.09(Physics, Nuclear)

60MeVまでの核分裂炉、核融合炉の中性子計測のための核データであるIRDFF-IIが公開された。このライブラリは、(a)研究炉応用、(b)商業炉の安全性応用、(c)核融合材料開発のための損傷研究、をサポートしている。本論文は、ライブラリの内容、検証プロセスについて述べ、幅広い中性子場でのベンチマークデータを提供している。このライブラリは様々な応用のための中性子計測における国際的な基準データとなることが期待される。

論文

In-source laser spectroscopy of dysprosium isotopes at the ISOLDE-RILIS

Chrysalidis, K.*; Barzakh, A. E.*; Ahmed, R.*; Andreyev, A. N.; Ballof, J.*; Cubiss, J. G.*; Fedorov, D. V.*; Fedosseev, V. N.*; Fraile, L. M.*; Harding, R. D.*; et al.

Nuclear Instruments and Methods in Physics Research B, 463, p.472 - 475, 2020/01

 被引用回数:2 パーセンタイル:62.87(Instruments & Instrumentation)

放射壊変によって生成された多数のジスプロシウム同位体について、ISOLDEのレーザー共鳴イオン源(RILIS)を用いてイオン源内レーザー分光法によって研究した。$$^{152}$$Dyに対する相対的な同位体シフトを$$4f^{10}6s^{2}~^{5}I_{8}$$ (gs) $$rightarrow$$ $$4f^{10}6s6p~(8,1)^{o}_{8}$$共鳴遷移を用いて測定した。電子的因子Fとマスシフト因子Mを導出し、それらを使って$$^{rm 145m}$$Dyと$$^{rm 147m}$$Dyの平均自乗荷電半径の変化を初めて決定した。

論文

$$alpha$$-decay properties of $$^{200,202}$$Fr

Ghys, L.*; Andreyev, A. N.; Huyse, M.*; Van Duppen, P.*; Antalic, S.*; Barzakh, A.*; Capponi, L.*; Cocolios, T. E.*; Cubiss, J.*; Derkx, X.*; et al.

Physical Review C, 100(5), p.054310_1 - 054310_13, 2019/11

 被引用回数:9 パーセンタイル:86.57(Physics, Nuclear)

The aim of this work was to investigate the $$alpha$$-decay properties of $$^{200,202}$$Fr and daughter products. Neutron-deficient francium nuclei are produced at ISOLDE-CERN bombarding a UCx target with 1.4 GeV protons. Due to the very high statistics and the high beam purity, improved decay data for $$^{202}$$Fr and its daughters were obtained. The observation of crossover transitions positioned the isomeric high-spin level of $$^{198}$$At at an excitation energy of 265(3) keV. Half-life values of 4.47(5) s and 1.28(10) s were extracted for the ground state and isomeric state of $$^{198}$$At and 52(3) ms for the ground-state decay of $$^{200}$$Fr.

論文

Electromagnetic properties of low-lying states in neutron-deficient Hg isotopes; Coulomb excitation of $$^{182}$$Hg, $$^{184}$$Hg, $$^{186}$$Hg and $$^{188}$$Hg

Wrzosek-Lipska, K.*; Rezynkina, K.*; Bree, N.*; Zieli$'n$ska, M.*; Gaffney, L. P.*; Petts, A.*; Andreyev, A. N.; Bastin, B.*; Bender, M.*; Blazhev, A.*; et al.

European Physical Journal A, 55(8), p.130_1 - 130_23, 2019/08

 被引用回数:7 パーセンタイル:80.58(Physics, Nuclear)

The neutron-deficient mercury isotopes serve as a classical example of shape coexistence, whereby at low energy near-degenerate nuclear states characterized by different shapes appear. The electromagnetic structure of even-mass $$^{182-188}$$Hg isotopes was studied using safe-energy Coulomb excitation of neutron-deficient mercury beams delivered by the REX-ISOLDE facility at CERN. The population of 0$$^{+}_{1,2}$$, 2$$^{+}_{1,2}$$, and 4$$^{+}_{1}$$ states was observed in all nuclei under study. Reduced $$E2$$ matrix elements coupling populated yrast and non-yrast states were extracted, including their relative signs. These are a sensitive probe of shape coexistence and may be used to validate nuclear models. The experimental results are discussed in terms of mixing of two different configurations and are compared with three different model calculations: the Beyond Mean Field model, the Interacting Boson Model with configuration mixing and the General Bohr Hamiltonian. Partial agreement with experiment was observed, hinting to missing ingredients in the theoretical descriptions.

論文

Main findings, remaining uncertainties and lessons learned from the OECD/NEA BSAF Project

Pellegrini, M.*; Herranz, L.*; Sonnenkalb, M.*; Lind, T.*; 丸山 結; Gauntt, R.*; Bixler, N.*; Morreale, A.*; Dolganov, K.*; Sevon, T.*; et al.

Proceedings of 18th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-18) (USB Flash Drive), p.1147 - 1162, 2019/08

The OECD/NEA Benchmark Study at the Accident of the Fukushima Daiichi NPS project (BSAF) has started in 2012 until 2018 as one of the earliest responses to the accident at Fukushima Daiichi NPS. The project addressed the investigation of the accident at Units 1, 2 and 3 by severe accident (SA) codes focusing on thermal-hydraulics, core relocation, molten core/concrete interaction (MCCI) and fission products release and transport. The objectives of BSAF were to make up plausible scenarios based primarily on SA forensic analysis, support the decommissioning and inform SA codes modeling. The analysis and comparison among the institutes have brought up vital insights regarding the accident progression identifying periods of core meltdown and relocation, reactor vessel (RV) and primary containment vessel (PCV) leakage/failure through the comparison of pressure, water level and CAMS measurement. The combination of code results and inspections has provided a picture of the current state of the debris distribution and plant state. All units present a large relocation of core materials and all of them present ex-vessel debris with units 1 and 3 showing evidences of undergoing MCCI. Uncertainties have been identified in particular on the time and magnitude of events such as corium relocation in RV and into cavity floor, RV and PCV rupture events. Main uncertainties resulting from the project are the large and continuous MCCI progression predicted by basically all the SA codes and the leak pathways from RV to PCV and PCV to reactor building and environment. The BSAF project represents a pioneering exercise which has set the basis and provided lessons learned not only for code improvement but also for the development of new related projects to investigate in details further aspects of the Fukushima Daiichi NPS accident.

論文

Neutron-induced damage simulations; Beyond defect production cross-section, displacement per atom and iron-based metrics

Sublet, J.-Ch.*; Bondarenko, I. P.*; Bonny, G.*; Conlin, J. L.*; Gilbert, M. R.*; Greenwood, L. R.*; Griffin, P. J.*; Helgesson, P.*; 岩元 洋介; Khryachkov, V. A.*; et al.

European Physical Journal Plus (Internet), 134(7), p.350_1 - 350_50, 2019/07

 被引用回数:8 パーセンタイル:41.21(Physics, Multidisciplinary)

核データを用いた原子核反応については、放射線照射を受けた材料のカスケード損傷による欠陥生成の起点となる。そのため、欠陥生成の指標となる一次はじき出し原子(PKA)、PKAの損傷エネルギー及び原子あたりのはじき出し数(DPA値)の導出において、原子核反応を正確に考慮することが重要となる。ここで、原子核反応を考慮した欠陥生成の評価手法(メトリクス)を用いることで、照射材料中の個々の欠陥やクラスタ化した欠陥のマクロな挙動をシミュレーションすることが可能となる。より具体的には、原子炉, 核融合, 加速器, 核医学, 宇宙分野等の様々な分野において、照射条件(入射粒子, 入射エネルギー, 材料等)に対応した損傷評価が可能となる。本論文は、核反応及び損傷エネルギーに関する最近の理論と進展をレビューするとともに、欠陥生成量を導出する際の核データにおける誤差の伝播、分子動力学に基づいた損傷計算等について述べる。

論文

Fine structure in the $$alpha$$ decay of $$^{218}$$At

Cubiss, J. G.*; Andreyev, A. N.; Barzakh, A. E.*; Andel, B.*; Antalic, S.*; Cocolios, T. E.*; Day Goodacre, T.*; Fedorov, D. V.*; Fedosseev, V. N.*; Ferrer, R.*; et al.

Physical Review C, 99(6), p.064317_1 - 064317_6, 2019/06

 被引用回数:5 パーセンタイル:69.53(Physics, Nuclear)

$$^{218}$$Atの$$alpha$$崩壊について、CERN-ISOLDE施設においてレーザーイオン化法を使うことで研究した。$$alpha$$-$$gamma$$同時計数データを初めて取得し、より精度の良い半減期の値として1.27(6)秒を得た。$$alpha$$崩壊の微細構造を基に新しい$$alpha$$崩壊図式を構築した。それらの結果から、$$^{218}$$Atの基底状態のスピン・パリティは(3$$^{-}$$)がより確からしいことが解ったが、(2)$$^{-}$$の可能性も完全には否定しきれない。

論文

Investigation of the $$Delta$$$$n$$ = 0 selection rule in Gamow-Teller transitions; The $$beta$$-decay of $$^{207}$$Hg

Berry, T. A.*; Podoly$'a$k, Zs.*; Carroll, R. J.*; Lic$u{a}$, R.*; Grawe, H.*; Timofeyuk, N. K.*; Alexander, T.*; Andreyev, A. N.; Ansari, S.*; Borge, M. J. G.*; et al.

Physics Letters B, 793, p.271 - 275, 2019/06

 被引用回数:3 パーセンタイル:52.47(Astronomy & Astrophysics)

Gamow-Teller $$beta$$ decay is forbidden if the number of nodes in the radial wave functions of the initial and final states is different. This $$Delta$$$$n$$ = 0 requirement plays a major role in the $$beta$$ decay of heavy neutron-rich nuclei, affecting the nucleosynthesis through the increased half-lives of nuclei on the astrophysical $$r$$-process pathway below both $$Z$$ = 50 (for $$N >$$ 82) and $$Z$$ = 82 (for $$N >$$ 126). The level of forbiddenness of the $$Delta$$$$n$$ = 1 $$nu$$1$$g_{9/2} rightarrow pi$$0$$g_{7/2}$$ transition has been investigated from the $$beta^{-}$$ decay of the ground state of $$^{207}$$Hg into the single-proton-hole nucleus $$^{207}$$Tl in an experiment at the ISOLDE Decay Station. From statistical observational limits on possible $$gamma$$-ray transitions depopulating the $$pi$$0$$g^{-1}_{7/2}$$ state in $$^{207}$$Tl, an upper limit of 3.9$$times$$10$$^{-3}$$ % was obtained for the probability of this decay, corresponding to log$$ft >$$ 8.8 within a 95% confidence limit. This is the most stringent test of the $$Delta$$$$n$$ = 0 selection rule to date.

論文

Shape coexistence in $$^{178}$$Hg

M$"u$ller-Gatermann, C.*; Dewald, A.*; Fransen, C.*; Auranen, K.*; Badran, H.*; Beckers, M.*; Blazhev, A.*; Braunroth, T.*; Cullen, D. M.*; Fruet, G.*; et al.

Physical Review C, 99(5), p.054325_1 - 054325_7, 2019/05

 被引用回数:5 パーセンタイル:69.53(Physics, Nuclear)

陽子過剰核$$^{178}$$Hgにおける変形共存を調べることを目的として、ユヴァスキュラ大学の加速器において$$^{103}$$Rh($$^{78}$$Kr, $$p2n$$)反応によって$$^{178}$$Hgを生成し、その原子核の励起状態からの脱励起の寿命を測定した。実験データを理論計算と比較した結果、$$^{178}$$Hgでは$$^{180}$$Hgに比べ、プロレート変形した状態がより高い励起状態へとシフトするとともに、変形度が増大することがわかった。

論文

Inverse odd-even staggering in nuclear charge radii and possible octupole collectivity in $$^{217,218,219}$$At revealed by in-source laser spectroscopy

Barzakh, A. E.*; Cubiss, J. G.*; Andreyev, A. N.; Seliverstov, M. D.*; Andel, B.*; Antalic, S.*; Ascher, P.*; Atanasov, D.*; Beck, D.*; Biero$'n$, J.*; et al.

Physical Review C, 99(5), p.054317_1 - 054317_9, 2019/05

 被引用回数:5 パーセンタイル:69.53(Physics, Nuclear)

Hyperfine-structure parameters and isotope shifts for the 795-nm atomic transitions in $$^{217,218,219}$$At have been measured at CERN-ISOLDE, using the in-source resonance-ionization spectroscopy technique. Magnetic dipole and electric quadrupole moments, and changes in the nuclear mean-square charge radii, have been deduced. A large inverse odd-even staggering in radii, which may be associated with the presence of octupole collectivity, has been observed. Namely, the radius of the odd-odd isotope $$^{218}$$At has been found to be larger than the average.

論文

Hydrogen-based metabolism as an ancestral trait in lineages sibling to the Cyanobacteria

Matheus Carnevali, P. B.*; Schulz, F.*; Castelle, C. J.*; Kantor, R. S.*; Shih, P. M.*; Sharon, I.*; Santini, J.*; Olm, M. R.*; 天野 由記; Thomas, B. C.*; et al.

Nature Communications (Internet), 10, p.463_1 - 463_15, 2019/01

 被引用回数:16 パーセンタイル:86.93(Multidisciplinary Sciences)

The metabolic platform in which microbial aerobic respiration evolved is tightly linked to the origins of Cyanobacteria (Oxyphotobacteria). Melainabacteria and Sericytochromatia, close phylogenetic neighbores to Oxyphotobacteria comprise both fermentative and aerobic representatives, or clades that are capablee of both. Here, we predict the metabolisms of Margulisbacteria from two distinct environments and Saganbacteria, and compare them to genomes of organisms from the related lineages. Melainabacteria BJ4A obtained from Mizunami site are potentially able to use O$$_{2}$$ and other terminal electron acceptors. The type C heme-copper oxygen reductase found in Melainabacteria BJ4A may be adapted to low O$$_{2}$$ levels, as expected for microaerophilic or anoxic environments such as the subsurface. Notably, Melainabacteria BJ4A seems to have a branched electron transport chain, with one branch leading to a cytochrome d ubiquinol oxidoreductase and the other one leading to the type C heme-copper oxygen reductase. Both these enzymes have high affinity for O$$_{2}$$, thus are adapted to low O$$_{2}$$ levels. These contemporary lineages have representatives with fermentative H$$_{2}$$-based metabolism, lineages capable of aerobic or anaerobic respiration, and lineages with both. Our findings support the idea that the ancestor of these lineages was an anaerobe in which fermentation and H$$_{2}$$ metabolism were central metabolic features.

論文

Conceptual uncertainties in modelling the interaction between engineered and natural barriers of nuclear waste repositories in crystalline rocks

Finsterle, S.*; Lanyon, B.*; ${AA}$kesson, M.*; Baxter, S.*; Bergstr$"o$m, M.*; Bockg${aa}$rd, N.*; Dershowitz, W.*; Dessirier, B.*; Frampton, A.*; Fransson, ${AA}$.*; et al.

Geological Society, London, Special Publications, No.482, p.261 - 283, 2019/00

 被引用回数:3 パーセンタイル:57.07

放射性廃棄物地層処分の信頼性は廃棄体パッケージとその周辺のベントナイトからなる緩衝材で構成される人工バリアと母岩の多重バリアに依存している。スウェーデン核燃料・廃棄物管理会社(SKB)はベントナイトと岩盤の相互作用の理解促進のためのモデリングタスクフォースを実施した。すなわち、異なる概念化とモデリングツールを採用した11のモデリングチームを活用して、エスポ硬岩研究所で実施された原位置試験の分析のためのモデルエクササイズを実施した。このエクササイズにより、人工バリアと天然バリアの相対的な重要度や、より信頼のあるベントナイト飽和予測に向けた現象理解に必要な視点、などの異なる評価結果を導く概念的な不確実性を抽出した。

論文

CIELO collaboration summary results; International evaluations of neutron reactions on uranium, plutonium, iron, oxygen and hydrogen

Chadwick, M. B.*; Capote, R.*; Trkov, A.*; Herman, M. W.*; Brown, D. A.*; Hale, G. M.*; Kahler, A. C.*; Talou, P.*; Plompen, A. J.*; Schillebeeckx, P.*; et al.

Nuclear Data Sheets, 148, p.189 - 213, 2018/02

 被引用回数:49 パーセンタイル:98.76(Physics, Nuclear)

CIELO国際協力では、原子力施設の臨界性に大きな影響を与える重要核種($$^{235}$$U, $$^{238}$$U, $$^{239}$$Pu, $$^{56}$$Fe, $$^{16}$$O, $$^{1}$$H)の中性子断面積データの精度を改善し、これまで矛盾していると考えられた点を解消することを目的として研究が行われた。多くの研究機関が参加したこのパイロットプロジェクトは、IAEAの支援も受けて、OECD/NEAの評価国際協力ワーキングパーティ(WPEC)のSubgroup 40として組織された。本CIELOプロジェクトは、新たな実験研究や理論研究を行う動機付けとなり、測定データを正確に反映し臨界性の積分テストに優れた新たな一連の評価済みライブラリとして結実した。本報告書は、これまでの研究成果と、本国際協力の次の段階の計画概要をまとめたものである。

79 件中 1件目~20件目を表示