Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Sr
CoO
at initial electrochemical process in an alkaline solutionMatsuzaki, Akira*; Hirayama, Masaaki*; Oguchi, Shoya*; Komo, Mamoru*; Ikezawa, Atsunori*; Suzuki, Kota*; Tamura, Kazuhisa; Arai, Hajime*; Kanno, Ryoji*
Electrochemistry (Internet), 90(10), p.107001_1 - 107001_8, 2022/10
Times Cited Count：0 Percentile：0.01(Electrochemistry)Oxygen reduction and evolution reactions (ORR and OER) of perovskite-type LaSrCoO were characterized using two-dimensional model electrodes with different reaction planes. Synthesized by pulsed laser deposition, these thin and flat electrodes can reveal the reaction plane dependence of the ORR activity. From steady-state polarization measurements in KOH (aq.), the ORR activity was the highest on the (001) film during the first ORR/OER cycle, and it decreased significantly during the second cycle. In-situ synchrotron X-ray diffraction clarified crystal structure changes in the bulk and surface regions of LaSrCoO, and these changes are associated with forming oxygen defects during the initial electrochemical process. Furthermore, the LaSrCoO surface partially decomposed upon reacting. Therefore, the interfacial structures formed in the electrochemical reaction field is important for enhancing ORR and OER activities.
Koarashi, Jun; Atarashi-Andoh, Mariko; Nagano, Hirohiko*; Sugiharto, U.*; Saengkorakot, C.*; Suzuki, Takashi; Kokubu, Yoko; Fujita, Natsuko; Kinoshita, Naoki; Nagai, Haruyasu; et al.
JAEA-Technology 2020-012, 53 Pages, 2020/10
JAEA-Technology-2020-012.pdf:3.71MB
There is growing concern that recent rapid changes in climate and environment could have a significant influence on carbon cycling in terrestrial ecosystems (especially forest ecosystems) and could consequently lead to a positive feedback for global warming. The magnitude and timing of this feedback remain highly uncertain largely due to a lack of quantitative understanding of the dynamics of organic carbon stored in soils and its responses to changes in climate and environment. The tracing of radiocarbon (natural and bomb-derived 
C) and stable carbon (
C) isotopes through terrestrial ecosystems can be a powerful tool for studying soil organic carbon (SOC) dynamics. The primary aim of this guide is to promote the use of isotope-based approaches to improve our understanding of the carbon cycling in soils, particularly in the Asian region. The guide covers practical methods of soil sampling; treatment and fractionation of soil samples; preparation of soil samples for C (and stable nitrogen isotope, 
N) and C analyses; and C, N, and C measurements by the use of isotope ratio mass spectrometry and accelerator mass spectrometry (AMS). The guide briefly introduces ways to report C data, which are frequently used for soil carbon cycling studies. The guide also reports results of a case study conducted in a Japanese forest ecosystem, as a practical application of the use of isotope-based approaches. This guide is mainly intended for researchers who are interested but are not experienced in this research field. The guide will hopefully encourage readers to participate in soil carbon cycling studies, including field works, laboratory experiments, isotope analyses, and discussions with great interest.
Be concentrations in bed-sediments of Ado and Yasu rivers flowing into Lake BiwaFujisawa, Jumpei*; Minami, Masayo*; Kokubu, Yoko; Matsuzaki, Hiroyuki*
JAEA-Conf 2018-002, p.91 - 94, 2019/02
Beryllium-10 (Be) of a cosmogenic nuclide precipitates in forms of BeO and Be(OH)
attaching with aerosol on the Earth surface. It is accumulated on the sea- and lake-bottoms. Recently, the meteoric Be is attracting attention as a powerful tool for investigating the past climate change, because it is affected by the earth- and lorcal- cyclical changes of materials such as atmosphere and water circulation. The Be exists mostly as hydroxide at pH 
5, and is easy to adhere to soil and mineral surface. Therefore, Be concentration in sediment could be influenced by its grain size composition because fine-grained sediment has a big surface area per unit mass. The purpose of this study is to reveal the relationship between Be concentrations and the grain-size of river sediments. The samples used were bottom-sediments of 18 rivers flowing into Lake Biwa, Japan. The sediments were sieved to 5 fractions and analyzed each for Be concentration by JAEA-AMS-TONO.
Be with JAEA-AMS-TONOKokubu, Yoko; Matsubara, Akihiro; Nishizawa, Akimitsu*; Owaki, Yoshio*; Nishio, Tomohiro*; Ishimaru, Tsuneari; Matsuzaki, Hiroyuki*
no journal, ,
no abstracts in English
SrCoOHirayama, Masaaki*; Matsuzaki, Akira*; Ikezawa, Atsunori*; Suzuki, Kota*; Arai, Hajime*; Kanno, Ryoji*; Tamura, Kazuhisa
no journal, ,
Oxygen reduction and evolution reactions (ORR and OER) of perovskite-type LaSrCoO were characterized using two-dimensional model electrodes with different reaction planes. Synthesized by pulsed laser deposition, these thin and flat electrodes can reveal the reaction plane dependence of the ORR activity. From steady-state polarization measurements in KOH (aq.), the ORR activity was the highest on the (001) film during the first ORR/OER cycle, and it decreased significantly during the second cycle. In-situ synchrotron X-ray diffraction clarified crystal structure changes in the bulk and surface regions of LaSrCoO, and these changes are associated with forming oxygen defects during the initial electrochemical process. Furthermore, the LaSrCoO surface partially decomposed upon reacting. Therefore, the interfacial structures formed in the electrochemical reaction field is important for enhancing ORR and OER activities.
