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—Measurement system and the characteristics—
Masayasu NOGUCHI, Kaneaki SATOH, Hideo HIGUCHI
1984 Volume 33 Issue 12 Pages
835-840
Published: December 15, 1984
Released on J-STAGE: September 07, 2010
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Pulse shape discrimination of α
and β
rays with liquid scintillation counting was investigated for the purpose of low level α
activity measurements. Various liquid scintillators for pulse shape discrimination were examined by means of pulse rise time analysis. A new scintillator of low cost and of superior characteristics was found. The figure of merits better than 3.5 in risetime spectrum and the energy resolution better than 9 % were obtained for carefully prepared samples. The background counting rate for a sample of 10 ml was reduced to 0.013 cpm/MeV in the range of α
ray energy 5 to 7 MeV.
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—Application to the determination of α-nuclides in environmental samples—
Kaneaki SATOH, Masayasu NOGUCHI, Hideo HIGUCHI, Kiyoshi KITAMURA
1984 Volume 33 Issue 12 Pages
841-846
Published: December 15, 1984
Released on J-STAGE: September 07, 2010
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Liquid scintillation counting of α
rays with pulse shape discrimination was applied to the analysis of 226Ra
and 239+240Pu
in environmental samples and of α-
emitters in/on a filter paper. The instrument used in this study was either a specially designed detector or a commercial liquid scintillation counter with an automatic sample changer, both of which were connected to the pulse shape discrimination circuit. The background counting rate in α
energy region of 5-7 MeV was 0.01 or 0.04 cpm/MeV, respectively. The figure of merit indicating the resolving power for α-
and β-
particles in time spectrum was found to be 5.7 for the commercial liquid scintillation counter.
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Tetsuo HASHIMOTO, Yasuo HAYASHI, Takeshi SOTOBAYASHI
1984 Volume 33 Issue 12 Pages
847-852
Published: December 15, 1984
Released on J-STAGE: September 07, 2010
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A measurement system for lyoluminescence has been constructed using a photon-counting apparatus equipped with a highly sensitive photomultiplier and a microcomputer for a data acquisition and processing. For the lyoluminescent dosimetry, seven saccharide samples, including five monosaccharides (glucose, mannose, galactose, levulose and ribose) and two disaccharides (sucrose and trehalose), were irradiated with 60Co
gamma rays. Effects on lyoluminescence were examined of the amounts of the sample, concentration of luminol phosphor in an aqueous solution, elapsed time after mixing the samples in the solution, variations of absorbed doses, annealing treatments and different radiation fields.
The results revealed that relatively small amounts of sample, say 3 mg, is sufficient for reproducible routine analyses by using 125 mg luminol/l for 10 s data accumulation, and that the lyoluminescent dosimetry is useful for the significantly high dose regions of 1 Gy-10kGy (the use of galactose and trehalose can extend the dose-region to higher levels) . The comparison of sensitivity for samples with the same dose (215 Gy) showed the great luminescent changes over one order of magnitude between the highest value for galactose and lowest one for ribose, although there is no substantial difference in the structure. No meaningful radiationquality effect was observed for monosaccharides irradiated with gamma-rays, X-rays, and neutrons.
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Norikatsu OOTSUKA, Tadatoshi YAMAMOTO, Kohei TSUKUI
1984 Volume 33 Issue 12 Pages
853-858
Published: December 15, 1984
Released on J-STAGE: September 07, 2010
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In the irradiation apparatus where unsealed 85Kr
gas is used as an internal radiation source for liquid-phase chemical reaction, the 85Kr
gas dissolved in a liquid reactant must be removed after irradiation. Experiments on removal of dissolved 85Kr
by the vacuum degassing method were carried out to examine the influence of degassing temperature, initial 85Kr
concentration and stirring of a solution on the removal. The liquid reactant used was a water of 500 ml in which 85Kr
gas was dissolved.
The removal effect became greater with increasing temperature. The dissolved 85Kr
concentration after removal decreased exponentially with the reciprocal of degassing temperature. Further, the removal effect was intensely affected by stirring of the solution and was independent of the initial 85Kr
concentration. The removal factor of dissolved 85Kr
at 33°C reached 5×103 after a 30 minute lapse.
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—A comparison with cerebral infarction and cerebrovascular dementia—
Sho WATANABE, Gonbei KAMIJIMA, Koichi MIYAKAWA, Yoshito SASAKI, Hirosh ...
1984 Volume 33 Issue 12 Pages
859-863
Published: December 15, 1984
Released on J-STAGE: September 07, 2010
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Nine cases of cerebral infarction (cerebrovascular dementia 4 cases, hemiparesis 4, aphasia 1) were investigated by intraarterial 133Xe
injection. Eight of the cases were male and one was female. Ages ranged from 38 to 72, with a mean age of 57.6 years. Two criteria were necessary for a diagnosis of cerebrovascular dementia: (1) the presence of cerebrovascular disease and (2) a score of less than 20 on Hasegawa's dementia scale.
Cases of cerebrovascular dementia tended to have a lower mean cerebral blood flow (CBF) value on the white matter by two-compartmental analysis. Two of the five brain areas showed statistically significant differences. These results support the modern theory that cerebrovascular dementia appears as a result of a disturbance of the white matter.
Cases of cerebrovascular dementia showed a lower mean CBF value with a coefficient of variance of regional distribution by height over area method. This showed that CBF values in cerebrovascular dementia were generally low and the range of values were narrow.
In a comparison of regional CBF and cerebral angiographical findings, cases of cerebrovascular dementia tended to have a lower mean CBF value in proportion to the severity of angiographical findings. In addition, regional CBF showed a tendency to agree closely with angiographical findings.
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Hisao YAMAMOTO, Satoru HATAKEYAMA, Toshiyuki NORIMURA, Takehiko TSUCHI ...
1984 Volume 33 Issue 12 Pages
864-866
Published: December 15, 1984
Released on J-STAGE: September 07, 2010
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A silicon photodiode is converted to a low energy charged particle radiation detector. The window thickness of the fabricated detector is evaluated to be 50μg/cm2.
The area of the depletion region is 13.2 mm2 and the depth of it is estimated to be about 100 pm. The energy resolution (FWHM) is 14.5 keV for α-
particles from 241Am
and 2.5 keV for conversion electrons from 109Cd,
respectively.
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—Effects of pressure variation and study for a non-flow type system—
Hiroshi MIYAHARA, Takumaro MOMOSE, Tamaki WATANABE
1984 Volume 33 Issue 12 Pages
867-870
Published: December 15, 1984
Released on J-STAGE: September 07, 2010
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Effects of the pressure variation of counting gas on the efficiency function were examined using a 4πβ-γ
coincidence counting system with a pressurized proportional counter. The results showed that the pressure variation of about ten kPa could not give large effects on the efficiency function and that a non-flow type of pressurized proportional counter with a simple gas control system could work well in the case of the pressure higher than 1 MPa, an ordinary pressure for the counting.
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Tadako KOUSAKA, Keiko TOMIDA, Keisuke ARAI, Takashi MISAKI, Kanji KASA ...
1984 Volume 33 Issue 12 Pages
871-874
Published: December 15, 1984
Released on J-STAGE: July 21, 2010
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Kanji KASAGI, Tadako KOUSAKA, Takashi MISAKI, Tetuo NAKASHIMA, Keigo E ...
1984 Volume 33 Issue 12 Pages
875-878
Published: December 15, 1984
Released on J-STAGE: July 21, 2010
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Isao KANAMORI, Toshitake YABASHI, Mikiko YANASE, Chizuko HIGUCHI, Hide ...
1984 Volume 33 Issue 12 Pages
879-882
Published: December 15, 1984
Released on J-STAGE: July 21, 2010
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Tadako KOUSAKA, Keiko TOMIDA, Yasuko KOUJIDA, Keigo ENDO, Junji KONISH ...
1984 Volume 33 Issue 12 Pages
883-886
Published: December 15, 1984
Released on J-STAGE: July 21, 2010
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Akio YOSHIMOTO, Yoshikatsu SAKAGISHI, Jean Dean LIU, Seiei TANAKA
1984 Volume 33 Issue 12 Pages
887-890
Published: December 15, 1984
Released on J-STAGE: July 21, 2010
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James A. BASSHAM
1984 Volume 33 Issue 12 Pages
891-901
Published: December 15, 1984
Released on J-STAGE: July 21, 2010
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Hajime SUGISAKI, Mayumi KAMEYAMA, Toshihiro YASHIMA, Kyoko SHIBATA
1984 Volume 33 Issue 12 Pages
902-907
Published: December 15, 1984
Released on J-STAGE: July 21, 2010
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Nobuo KUMANO
1984 Volume 33 Issue 12 Pages
908-915
Published: December 15, 1984
Released on J-STAGE: July 21, 2010
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1984 Volume 33 Issue 12 Pages
A89P-A128M
Published: December 15, 1984
Released on J-STAGE: July 21, 2010
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