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Volume 9, Issue 1
Displaying 1-13 of 13 articles from this issue
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Hiroyuki YOSHIDA, Toshimitsu SAGANE1972 Volume 9 Issue 1 Pages 1-6
Published: January 25, 1972
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThe ageing characteristics of Cu-Be alloys were studied through measurements of the electrical resistance during neutron irradiation with fluxes of 1.5×1011nf and 2.3×102nth/cm2•sec in the temperature range of 100° to 160°C. The resistance of super-saturated specimens incteased rapidly during the initial period, reached a maximum (ρmax), and then decreased slowly. During high temperature irradiation the rate of the resistance change was larger for all specimens and the time to reach the ρmax, was much shorter than during thermal ageing at the same temperature. The reason is that the G. P. zone formation and the precipitation of γ' phases in Cu-Be alloys is accelerated markedly by irradiation. Based on experimental activation energies for the process, the acceleration mechanism is discussed.View full abstractDownload PDF (448K) -
Haruko MATSUOKA, Kuniyoshi SATO, Yoshimi ASAHI, Takahiro MASUDA, Masah ...1972 Volume 9 Issue 1 Pages 7-10
Published: January 25, 1972
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSHammett's reaction constants for the reactions of solvated electrons with substituted chrolobenzene series are 0.7 and 2.5 in cyclohexane-2-propanol and methanol-water systems respectively. The simple relation observed in alcoholic solvents between Hammett's reaction constants and the dielectric constant fails to apply to the present systems. These findings can be semiquantitatively explained as being a result of the closer correlation presented by Hammett's reaction constants to the transition energy for the optical excitation of solvated electrons rather than to the dielectric constants of the medium.View full abstractDownload PDF (289K) -
Toshihiko OHMICHI, Shoichi NASU, Takeo KIKUCHI1972 Volume 9 Issue 1 Pages 11-18
Published: January 25, 1972
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThe magnetic susceptibility χ of UC1-xNx has been measured in the temperature range from 4° to 1, 100°K. In the case of UN, χ has maximum point at 52°K which is characteristic of antiferro-paramagnetic transition. This peaking of χ is observed up to 50% UC. The Neel temperature TN does not change significantly with the content of carbon, nor does the Curie paramagnetic temperature θ change in the paramagnetic composition region, whereas magnetic moment np decreases markedly and evenly with increasing carbon content. In the case of UC, χ decreases with T2 at high temperature. This is also observed in paramagnetic UC1-xNx. Further, some anomalies which are not related to magnetic transition are observed in χ-T curves of UC1-xNx. These phenomena are explained in terms of the interaction between 7s electrons and localized 5f electrons, and of the particular characteristics of the electron bands in these compounds.View full abstractDownload PDF (611K) -
Doppler Effect and Its Influence on Power Transient ShapeHidemasa KATO1972 Volume 9 Issue 1 Pages 19-27
Published: January 25, 1972
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThe Doppler effect and its influence on the shape of the power burst are studied by analyzing the experimental data from self-limiting power excursion tests on the HTR (Hitachi Training Reactor)-P core (UO2 ceramic fuel, water moderated, enriched to 10% in 235U). Uniform temperature distribution in the fuel element has usually been assumed hitherto for evaluating the Doppler reactivity feedback during a power excursion. In the HTR experiment, however some discrepancy is found in the power transient curve between the experimental results and the calculation with uniform temperature model. It is shown that most of this discrepancy can be explained as being due to the influence of the transient variation of the non-uniform temperature distribution in the fuel element, and also to the large contribution of the surface term of the effective resonance integral.View full abstractDownload PDF (593K) -
Fumio KIKUCHI, Yoshio ANDO1972 Volume 9 Issue 1 Pages 28-35
Published: January 25, 1972
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSBased on Hellinger-Reissner's variational principle, a rectangular finite element for plate bending is derived with bilinearly varying deflection and incompletely linear moments. This method is an example of the mixed method first proposed by Herrmann, where both displacement and stress are adopted simultaneously as fundamental variables. Because continuity conditions required on the fundamental variables are much relaxed compared with compatible models, suitable shape functions can be easily derived and calculation of the element matrix can be performed by hand. The explicit expression of the element matrix for general orthotropic plates is presented in this paper. A few simple test problems are computed in order to demonstrate the accuracy of the present model, and it is shown that it gives improved results compared with Herrmann's triangular element. Convergence is also assured when suitably small mesh sizes are adopted, and this element can be utilized in general practical problems.View full abstractDownload PDF (484K) -
Seiji UKAI, Toru HIRAOKA1972 Volume 9 Issue 1 Pages 36-46
Published: January 25, 1972
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThe eigenvalue spectrum of the neutron transport operator for fast multiplying systems is discussed under the continuous energy treatment and with the assumption of isotropic distribution of the neutrons emitted by scattering and fission. In particular, the sufficient conditions are presented for the existence and non-existence of what is known as the fundamental mode. Further, it will be shown that, if the energy transfer kernel is positive almost everywhere, then the eigenvalue for the fundamental mode is strictly larger than the real part of any other eigenvalue and there are no non-negative eigenfunctions excepting the fundamental mode.View full abstractDownload PDF (1423K) -
Fundamental Characteristics of Plastic Wall CounterYoshiyuki NAKASHIMA, Minoru KAWANO1972 Volume 9 Issue 1 Pages 47-52
Published: January 25, 1972
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThe relation between exposure rate and energy loss of secondary electrons in the sensitive volume of a plastic wall counter was derived. The possibilities presented by a proportional counter for use in dosimetry were examined for the case of a combination of polyethylene wall and methane gas. Absolute measurement was found possible by calibration of the observed pulse-height distribution. It was also shown that low exposure rates could be effectively measured with counters provided with small sensitive volume. The characteristics of the counter when used as dosimeter proved very close to those of an ionization chamber.View full abstractDownload PDF (447K) -
1972 Volume 9 Issue 1 Pages 52
Published: 1972
Released on J-STAGE: December 19, 2008
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Toshikazu TAKEDA, Kazuhiro NAKAMURA, Tamotsu SEKIYA1972 Volume 9 Issue 1 Pages 53-54
Published: January 25, 1972
Released on J-STAGE: December 19, 2008
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Tatsusaburo SUZUKI, Kazumasa INOUE1972 Volume 9 Issue 1 Pages 55-57
Published: January 25, 1972
Released on J-STAGE: December 19, 2008
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Hideki TAKANO, Yukio ISHIGURO1972 Volume 9 Issue 1 Pages 57-60
Published: January 25, 1972
Released on J-STAGE: December 19, 2008
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Akito TAKAHASHI, Kiyomi ISHIJIMA1972 Volume 9 Issue 1 Pages 60-64
Published: January 25, 1972
Released on J-STAGE: December 19, 2008
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Kiyokazu INAGAKI, Akira DOI, Hajime YAMAMOTO, Hiroshi KITAGUCHI1972 Volume 9 Issue 1 Pages 64-66
Published: January 25, 1972
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSDownload PDF (180K)
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