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Journal Articles

Chemical characterization of a volatile dubnium compound, DbOCl$$_3$$

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:0 Percentile:0(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 $$^circ$$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$$_3 > $$ TaOCl$$_3 geq$$ DbOCl$$_3$$. From the obtained experimental results, thermochemical data for DbOCl$$_3$$ were derived. The present study delivers reliable experimental information for theoretical calculations on the chemical properties of transactinides.

Journal Articles

Optimization of an isothermal gas-chromatographic setup for the chemical exploration of dubnium (Db, Z = 105) oxychlorides

Chiera, N. M.; Sato, Tetsuya; Tomitsuka, Tomohiro; Asai, Masato; Ito, Yuta; Shirai, Kaori*; Suzuki, Hayato; Tokoi, Katsuyuki; Toyoshima, Atsushi; Tsukada, Kazuaki; et al.

Journal of Radioanalytical and Nuclear Chemistry, 320(3), p.633 - 642, 2019/06

 Times Cited Count:1 Percentile:23.13(Chemistry, Analytical)

An isothermal gas-chromatographic (IGC) device has been developed and tested for on-line gas phase studies of volatile oxychlorides of short-lived group-5 transition metals. Radioisotopes of niobium and tantalum, produced in nuclear fusion evaporation reactions, are directly flushed into the IGC setup by an inert gas-jet. Oxychloride compounds are formed by the addition of SOCl$$_2$$ and O$$_2$$. Parameters influencing the formation and transport of NbOCl$$_3$$ and TaOCl$$_3$$ are investigated. For nuclides with half-lives ($$t_{1/2}$$) of about 30 s, an overall efficiency of 7% is obtained, rendering the IGC setup suitable for the chemical exploration of $$^{262}$$Db($$t_{1/2}$$ = 34s).

Journal Articles

Formation and thermochemical properties of oxychlorides of niobium (Nb) and tantalum (Ta); Towards the gas-phase investigation of dubnium (Db) oxychloride

Chiera, N. M.; Sato, Tetsuya; Tomitsuka, Tomohiro; Asai, Masato; Suzuki, Hayato*; Tokoi, Katsuyuki; Toyoshima, Atsushi; Tsukada, Kazuaki; Nagame, Yuichiro

Inorganica Chimica Acta, 486, p.361 - 366, 2019/02

 Times Cited Count:2 Percentile:24.66(Chemistry, Inorganic & Nuclear)

The formation of NbOCl$$_3$$ and TaOCl$$_3$$ and their adsorption behavior on quartz surfaces was explored by applying an isothermal gas-chromatographic method. Trace amounts of short-lived Nb and Ta isotopes were used. Adsorption enthalpy values ($$Delta H_{rm ads}$$) at zero surface coverage of -$$Delta H_{rm ads}$$(NbOCl$$_3$$) = 102 $$pm$$ 4 kJ/mol and -$$Delta H_{rm ads}$$(TaOCl$$_3$$) = 128 $$pm$$ 5 kJ/mol were determined by analyzing the chromatographic behavior of the Nb andTa complexes with a Monte-Carlo simulation method based on an adsorption-desorption kinetic model.By applying an empirical correlation, the experimental $$Delta H_{rm ads}$$ values were successively related to the macroscopic standard sublimation enthalpy, $$Delta H^circ _{rm subl}$$, as a measure of the volatility of each substance. The inferred sublimation enthalpies are in agreement with tabulated thermochemical values. Thus, the linear empirical correlation between $$Delta H_{rm ads}$$ and $$Delta H^circ _{rm subl}$$ for metal-oxychlorides was updated with the inclusion of the present data. According to the predicted $$Delta H^circ _{rm subl}$$(DbOCl$$_3$$), a $$Delta H_{rm ads}$$(DbOCl$$_3$$) value of 135 $$pm$$ 2 kJ/mol was extrapolated. The future accomplishment of comparative studies with DbOCl$$_3$$ under the same experimental conditions will provide valuable information on the volatility trend in Group-5 elements, together with an indication on the magnitude of relativistic effects on the electronic structure of dubnium.

Journal Articles

Extraction of chromatographic behavior of Rf, Zr, and Hf in HCl solution with styrenedivinylbenzene copolymer resin modified by TOPO (trioctylphosphine oxide)

Toyoshima, Atsushi; Kasamatsu, Yoshitaka*; Tsukada, Kazuaki; Asai, Masato; Ishii, Yasuo; Tome, Hayato*; Nishinaka, Ichiro; Sato, Tetsuya; Nagame, Yuichiro; Sch$"a$del, M.; et al.

Journal of Nuclear and Radiochemical Sciences, 11(1), p.7 - 11, 2010/06

The extraction behavior of rutherfordium (Rf) into trioctylphosphine oxide (TOPO) from 2.0 - 7.0 M HCl solution was studied together with that of the homologues Zr and Hf. The extracted yields of Rf, Zr, and Hf increased with an increase of HCl concentration, and the sequence of their extraction was Zr $$>$$ Hf $$geq$$ Rf. It is suggested that the stability of the RfCl$$_{4}$$$$cdot$$2(TOPO) complex is lower than that of the corresponding species of the homologues.

Journal Articles

Anionic fluoro complex of element 105, Db

Kasamatsu, Yoshitaka*; Toyoshima, Atsushi; Asai, Masato; Tsukada, Kazuaki; Li, Z.; Ishii, Yasuo; Tome, Hayato*; Sato, Tetsuya; Kikuchi, Takahiro; Nishinaka, Ichiro; et al.

Chemistry Letters, 38(11), p.1084 - 1085, 2009/10

 Times Cited Count:14 Percentile:49.52(Chemistry, Multidisciplinary)

We report on the characteristic anion-exchange behavior of the superheavy element dubnium (Db) with atomic number Z = 105 in HF/HNO$$_{3}$$ solution at the fluoride ion concentration [F$$^{-}$$] = 0.003 M. The result clearly demonstrates that the fluoro complex formation of Db is significantly different from that of the group-5 homologue Ta in the 6th period of the periodic table while the behavior of Db is similar to that of the lighter homologue Nb in the 5th period.

Journal Articles

Oxidation of element 102, nobelium, with flow electrolytic column chromatography on an atom-at-a-time scale

Toyoshima, Atsushi; Kasamatsu, Yoshitaka*; Tsukada, Kazuaki; Asai, Masato; Kitatsuji, Yoshihiro; Ishii, Yasuo; Tome, Hayato; Nishinaka, Ichiro; Haba, Hiromitsu*; Oe, Kazuhiro*; et al.

Journal of the American Chemical Society, 131(26), p.9180 - 9181, 2009/07

 Times Cited Count:13 Percentile:47.75(Chemistry, Multidisciplinary)

We report here on the successful oxidation of element 102, nobelium (No), on an atom-at-a-time scale in 0.1 M $$alpha$$-hydroxyisobutyric acid ($$alpha$$-HIB) solution using newly developed flow electrolytic column chromatography. It is found that the most stable No$$^{2+}$$ is oxidized to No$$^{3+}$$ within 3 min and that the oxidized No complex with $$alpha$$-HIB holds the trivalent state in the column above the applied potential of 1.0 V.

Journal Articles

EUV spectra from highly charged tin ions observed in low density plasma in LHD

Suzuki, Chihiro*; Kato, Takako*; Sato, Kuninori*; Tamura, Naoki*; Kato, Daiji*; Sudo, Shigeru*; Yamamoto, Norimasa*; Tanuma, Hajime*; Ohashi, Hayato*; Suda, Shintaro*; et al.

Journal of Physics; Conference Series, 163, p.012019_1 - 012019_4, 2009/06

 Times Cited Count:9 Percentile:93.21

We have measured EUV spectra from highly charged tin ions in low density plasmas produced in the Large Helical Device (LHD). The well known dense spectral structure around 13.5 nm is measured when the plasma is rapidly cooled and approaching radioactive collapse, while the sparse spectrum with several unidentified discrete lines from 13.8-14.6 nm is observed if the plasma is cooled more slowly. The dominant charge states in the former case are Sn$$^{11+}$$ -Sn$$^{14+}$$. The latter case may be explained by considering the spectral lines from charge states higher than Sn$$^{19+}$$.

Journal Articles

Extraction behavior of rutherfordium into tributylphosphate from hydrochloric acid

Haba, Hiromitsu*; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Ishii, Yasuo; Tome, Hayato; Sato, Tetsuya; Nishinaka, Ichiro; Ichikawa, Takatoshi; Ichikawa, Shinichi; et al.

Radiochimica Acta, 95(1), p.1 - 6, 2007/01

 Times Cited Count:15 Percentile:73.12(Chemistry, Inorganic & Nuclear)

no abstracts in English

JAEA Reports

Report of tests for radiation control executed in the JOYO MK-III performance tests

Hoshiba, Hideaki; Hashimoto, Makoto; Irokawa, H.; Usui, Toshihide; Sato, Hayato; Emori, Shuichi

JNC TN9410 2004-017, 170 Pages, 2004/08

JNC-TN9410-2004-017.pdf:18.93MB

While the JOYO MK-III Project, after the modification of primary coolant system started in oct.2000 and the integrated function tests, from Jun.2003, the performance test was executed for the purpose of verification of designed performance and confirmation of basic characteristics as an irradiation reactor. While the JOYO MK-III performance test, 28 tests were executed. Radiation control section took charge of 3 of them, "Dose Rate Distribution", "Radiation Control" and "Gaseous Waste Radioactive Concentration Measurement". The performance tests in charge of radiation control section was started on Jun.27, 2003, that is before the start-up of reactor, and were carried out when the thermal output of reactor was 40MWt, 70MWt, 105MWt and effective full power, 140MWt. The pre-operation tests in charge of radiation control section are "Test of dose rate measurement in operation and after shutdown". "Test of radioactive concentration measurement of air", and "Test of gaseous waste processing performance". The final test was "Test of dose rate measurement after shutdown", which was executed on Nov.27 2003. JOYO passed the inspection and the performance test was finished. The representative results in these performance tests are; 1.Every result is under the criterion 2.Dose rate and monitoring data are totally less than the data in MK-II operation. Though it confirmed that all the data are under the criterion, it is considered that these tests should be performed at proper intervals because the circumstances may change.

Journal Articles

Reaction methanol with hydriodic acid as a step of CIS process

Onuki, Kaoru; Shimizu, Saburo; Nakajima, Hayato; Ikezoe, Yasumasa; Sato, Shoichi

International Journal of Hydrogen Energy, 15(2), p.93 - 97, 1990/00

 Times Cited Count:0 Percentile:0.04(Chemistry, Physical)

no abstracts in English

Journal Articles

Hydrogen reduction of nickel oxide

Nakajima, Hayato; Shimizu, Saburo; Onuki, Kaoru; Ikezoe, Yasumasa; Sato, Shoichi

Nihon Kagakkai-Shi, 1989(4), p.681 - 686, 1989/04

no abstracts in English

Journal Articles

A Nickel-iodine-sulfur process for hydrogen production

Sato, Shoichi; Shimizu, Saburo; Nakajima, Hayato; Ikezoe, Yasumasa

Int.J.Hydrogen Energy, 8(1), p.15 - 22, 1983/00

 Times Cited Count:12 Percentile:85.67(Chemistry, Physical)

no abstracts in English

Oral presentation

Formation of anionic chloride complex of Rutherfordium (Rf)

Tsukada, Kazuaki; Toyoshima, Atsushi; Haba, Hiromitsu*; Asai, Masato; Akiyama, Kazuhiko*; Ishii, Yasuo; Tome, Hayato*; Nishinaka, Ichiro; Sato, Tetsuya; Ichikawa, Takatoshi; et al.

no journal, , 

no abstracts in English

Oral presentation

TBP reversed-phase extraction chromatography of Rutherfordium in the HCl solution

Toyoshima, Atsushi; Haba, Hiromitsu*; Tsukada, Kazuaki; Asai, Masato; Akiyama, Kazuhiko*; Ishii, Yasuo; Tome, Hayato*; Nishinaka, Ichiro; Sato, Tetsuya; Ichikawa, Takatoshi; et al.

no journal, , 

no abstracts in English

Oral presentation

Chloride complex formation of Rf in HCl and CH$$_{3}$$OH mixed solution

Tsukada, Kazuaki; Toyoshima, Atsushi; Haba, Hiromitsu*; Asai, Masato; Akiyama, Kazuhiko*; Ishii, Yasuo; Tome, Hayato; Nishinaka, Ichiro; Sato, Tetsuya; Ichikawa, Shinichi; et al.

no journal, , 

no abstracts in English

Oral presentation

TOPO reversed-phase extraction behavior of rutherfordium in HCl solutions

Toyoshima, Atsushi; Kasamatsu, Yoshitaka; Tsukada, Kazuaki; Haba, Hiromitsu*; Asai, Masato; Ishii, Yasuo; Tome, Hayato; Sato, Tetsuya; Nishinaka, Ichiro; Nagame, Yuichiro; et al.

no journal, , 

no abstracts in English

Oral presentation

TOPO reversed-phase extraction behavior of rutherfordium in HCl solutions

Toyoshima, Atsushi; Kasamatsu, Yoshitaka; Tsukada, Kazuaki; Haba, Hiromitsu*; Asai, Masato; Ishii, Yasuo; Tome, Hayato; Sato, Tetsuya; Nishinaka, Ichiro; Nagame, Yuichiro; et al.

no journal, , 

no abstracts in English

Oral presentation

Oxidation of nobelium

Toyoshima, Atsushi; Kasamatsu, Yoshitaka; Kitatsuji, Yoshihiro; Tsukada, Kazuaki; Ishii, Yasuo; Tome, Hayato; Asai, Masato; Haba, Hiromitsu*; Akiyama, Kazuhiko*; Oe, Kazuhiro*; et al.

no journal, , 

no abstracts in English

Oral presentation

Fluoride complex formation of element 104, rutherfordium

Nagame, Yuichiro; Toyoshima, Atsushi; Ishii, Yasuo; Tsukada, Kazuaki; Asai, Masato; Tome, Hayato; Kasamatsu, Yoshitaka; Nishinaka, Ichiro; Sato, Tetsuya; Haba, Hiromitsu*; et al.

no journal, , 

We present a study of fluoride complex formation of Rf at Japan Atomic Energy Agency (JAEA). Anion- and cation-exchange behavior of Rf was systematically investigated in HF/HNO$$_{3}$$ mixed solution together with the lighter homologues Zr and Hf using the automated ion-exchange separation apparatus coupled with the detection system for alpha spectroscopy. We unequivocally determined the species of Rf on the binding sites of the resin as the hexafluoro complex [RfF$$_{6}$$]$$^{2-}$$. It is found that there is about two-orders of magnitude difference in the fluoride ion concentration between Rf and the homologues for the formation of the hexafluoro complexes. The result clearly demonstrates that the formation of the fluoride complexes of Rf is much weaker than those of the homologues Zr and Hf.

Oral presentation

Electrochemical oxidation of nobelium

Toyoshima, Atsushi; Kasamatsu, Yoshitaka; Tsukada, Kazuaki; Kitatsuji, Yoshihiro; Haba, Hiromitsu*; Ishii, Yasuo; Tome, Hayato; Asai, Masato; Akiyama, Kazuhiko*; Oe, Kazuhiro*; et al.

no journal, , 

Electrochemical oxidation of nobelium (No) produced in the $$^{248}$$Cm($$^{12}$$C, 5n)$$^{255}$$No reaction was studied using a new electrochemistry apparatus combined with chromatographic separation technique. Chromatographic behaviour of $$^{255}$$No in 0.1 M $$alpha$$-hydroxyisobutyric acid ($$alpha$$-HIB) on the electrode surface was measured with verifying the difference in behaviour between divalent $$^{81}$$Sr$$^{2+}$$ and trivalent $$^{162}$$Yb$$^{3+}$$ ions. Independently of the applied potentials, Yb$$^{3+}$$ was eluted in the 0.1 M $$alpha$$-HIB while Sr$$^{2+}$$ was adsorbed on the electrode. At the low potential of 0.2 V, $$^{255}$$No was adsorbed on the electrode, indicating that No is bound in the most stable divalent state. On the other hand, at the higher potential of 1.2 V, $$^{255}$$No was unambiguously detected in the 0.1 M $$alpha$$-HIB, showing that No exists as a trivalent ion. These results demonstrate that the electrochemical oxidation of No$$^{2+}$$ to No$$^{3+}$$ is successfully performed.

46 (Records 1-20 displayed on this page)