Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Chiera, N. M.*; Sato, Tetsuya; Eichler, R.*; Tomitsuka, Tomohiro; Asai, Masato; Adachi, Sadia*; Dressler, R.*; Hirose, Kentaro; Inoue, Hiroki*; Ito, Yuta; et al.
Angewandte Chemie; International Edition, 60(33), p.17871 - 17874, 2021/08
Times Cited Count：2 Percentile：14.88(Chemistry, Multidisciplinary)The formation and the chemical characterization of single atoms of dubnium (Db, element 105), in the form of its volatile oxychloride, was investigated using the on-line gas phase chromatography technique, in the temperature range 350 - 600 
C. Under the exact same chemical conditions, comparative studies with the lighter homologs of group-5 in the Periodic Table clearly indicate the volatility sequence being NbOCl
TaOCl
DbOCl. From the obtained experimental results, thermochemical data for DbOCl were derived. The present study delivers reliable experimental information for theoretical calculations on the chemical properties of transactinides.
Ijiri, Yuji*; Hattori, Hiromichi*; Suzuki, Shunichi*; Oishi, Masaya*; Kubota, Shigeru*; Adachi, Tetsuya*; Yamamoto, Takuya*
JNC TJ8400 2001-010, 143 Pages, 2001/03
JNC-TJ8400-2001-010.pdf:17.19MB
The evaluation of uncertainty of geological environment is a key issue in assessing a performance of a deep geological disposal system for high-level nuclear waste. The geological environment uncertainty is arose from data obtained from surveys and model used for a performance assessment.The objectives of this study is to develop a rational planning methodology of site characterization using the Horonobe site as a model case, and to establish a modeling methodology using the Tono site as a model case. At the Horonobe site, first, a conceptual model is constructed based on the information at every stage of site characterization procedure. A sensitivity analysis is performed using various conceptual models and data. If conceptual models uncertainty have a great impact on the result of performance assessment analysis, surveys that detect the most appropriate conceptual model are conducted in the next stage of site characterization. If data uncertainty have a great impact on the result of performance assessment analysis, surveys that decrease the data uncertainty are conducted. Thus, a rational site characterization methodology in which the most sensitive items are preferentially detected in the next stage of site characterization is developed. This concept of a rational site characterization methodology is described in this report. In addition, preliminary conceptual model is developed based on geological information around Horonobe site, and data uncertainty for the sensitivity analysis which will be conducted in next year is investigated. At the Tono site, literature on model uncertainty is surveyed, and data obtained at the Tono site is reviewed from modeling point of view.
Ijiri, Yuji*; Hattori, Hiromichi*; Suzuki, Shunichi*; Oishi, Masaya*; Kubota, Shigeru*; Adachi, Tetsuya*; Yamamoto, Takuya*; Igarashi, Takafumi*; Sugihara, Yutaka*
JNC TJ8400 2001-009, 41 Pages, 2001/03
JNC-TJ8400-2001-009.pdf:6.69MB
no abstracts in English
*; *; Adachi, Tetsuya*; Ijiri, Yuji*; Sugihara, Yutaka*
JNC TJ7400 2001-008, 293 Pages, 2001/03
JNC-TJ7400-2001-008.pdf:10.15MB
no abstracts in English
Ijiri, Yuji*; Adachi, Tetsuya*; Suzuki, Shunichi*; Oishi, Masaya*; Sugihara, Yutaka*
JNC TJ8440 2001-002, 93 Pages, 2001/02
JNC-TJ8440-2001-002.pdf:4.19MB
no abstracts in English
Anezaki, Susumu*; Sugihara, Yutaka*; Igarashi, Takafumi*; Yamamoto, Takuya*; Adachi, Tetsuya*; Suzuki, Shunichi*; Oishi, Masaya*
JNC TJ1410 2000-001, 123 Pages, 2000/03
Anezaki, Susumu*; Adachi, Tetsuya*; Suzuki, Shunichi*
JNC TJ7400 99-007, 61 Pages, 1999/02
no abstracts in English
Anezaki, Susumu*; Sugihara, Yutaka*; Igarashi, Takafumi*; Kubota, Shigeru*; Adachi, Tetsuya*
JNC TJ1410 98-001, 74 Pages, 1998/10
As a technical problem to be solved in the underground research of sedimentary rock formation, the specification for access drift from the surface to the experimental area in the underground was studied. Considering ground condition, safety for construction and experiment execution, maintenance of experimental environment, construction period and cost, the feasibility of access drift was carried out.
; ; Adachi, Tetsuya; Sato, Toshinori;
PNC TN7410 95-049, 47 Pages, 1995/10
Excavation of a shaft or a horizontal drift in a rock mass probably affects the rock mass around the underground openings. It is necessary in the design, construction and safety assessment of underground facilities to consider the properties and extent of the EDZ (Excavation Disturbed Zone; the zone where rock properties and rock conditions have been changed due to excavation). In-situ experiment on excavation disturbance has been carried out in the Tono mine and the controlling factors of properties and extent of the EDZ due to blasting has been studied. In order to evaluate dependence of the change of properties and extent of the EDZ on excavation method, Machine Excavation Effects Experiment has been carried out. In FY 1992, a horizontal drift for measurements was excavated. A horizontal drift parallel to the measuring drift is scheduled to be excavated by a machine in FY 1995. The investigations and numerical analysis before excavation of the test drift were carried out in FY 1993 and FY 1994. The objectives of the investigations and numerical analysis carried out in FY 1993 and 1994 are as follows: (1)to measure and evaluate the rock properties and the rock conditions around the test drift before excavation, and (2)to predict the displacements and stress change during excavation of the test drift. The investigations and numerical analysis in FY 1994 consist of the following items: (1)core logging and borehole wall observation, (2)installation of extensometers, and (3)numerical analysis with the Finite Element Method. This report describes the details of the investigations and numerical analysis carried out in FY 1994.
Hiroki, Seiji; Abe, Tetsuya; Murakami, Yoshio; *; *; *
Shinku, 31(10), p.850 - 853, 1988/10
no abstracts in English
Sato, Tetsuya; Chiera, N. M.*; Tomitsuka, Tomohiro; Tokoi, Katsuyuki*; Suzuki, Hayato*; Ito, Yuta; Asai, Masato; Shirai, Kaori*; Inoue, Hiroki*; Adachi, Sadia*; et al.
no journal, ,
The influence of strong relativistic effects on chemical properties has been interesting in the superheavy element region. Their chemical properties, however, have not been investigated sufficiently because of experimental difficulties owing to their low production rates and short half-lives. In order to elucidate the chemical properties of dubnium (Db, Z = 105), we have conducted on-line isothermal gas chromatographic experiments of oxychloride of group-5 elements. We confirmed the formation of volatile oxychlorides of Db and its lighter homologs Nb and Ta by using 
Db (half-life, 
= 33.8 s), 
Nb ( = 14.5 min.), and 
Ta ( = 6.76 min.), respectively. We successfully determined the adsorption enthalpies of the oxychlorides of each element on the quartz surface from their isothermal gas chromatographic behavior. The obtained volatility sequence of the group-5 elements is found to be Nb 
Ta 
Db.
