Showing papers by "Japan Atomic Energy Research Institute published in 1971"
83 citations
TL;DR: In this article, the authors measured the yield stress of Cu and Cu base solid solutions from room temperature down to 1.6 K. They attributed the anomalies to dynamical motion of dislocation and point defects due to climbing motion of the dislocation, respectively.
Abstract: Yield stress of Cu and Cu base solid solutions is measured from room temperature down to 1.6 K. Two kinds of anomalous behavior of the yield stress of the solid solutions are observed below 50 and 10 K. From theoretical considerations, these anomalies are attributed to dynamical motion of dislocation and to dynamical production of point defects due to climb motion of the dislocation, respectively. Hysteresis behavior of the temperature dependence of the yield stress, which is due to the dynamically produced point defects, is observed in very low temperature region. Criterion for applicability of chemical rate process to the motion of dislocation is discussed.
81 citations
TL;DR: In this article, a solid angle subtended by a rectangular slit with an arbitrary thickness at an arbitrary point is represented by inverse trigonometric functions, where the function is a function of the angle.
60 citations
TL;DR: A radio-resistant Pseudomonas has been isolated from samples of normal unpolished and commercial rice grains and was found to be sufficiently different from all the described species in this genus to warrant it’s description as a new species.
Abstract: A radio-resistant Pseudomonas has been isolated from samples of normal unpolished and commercial rice grains. This species could be classified in chromogenic group of genus Pseudomonas. It’s taxonomic characteristics were found to be sufficiently different from all the described species in this genus to warrant it’s description as a new species and was named as Pseudomonas radiora nov. sp.The radio-resistance of this species was 10 to 40 times higher than that of ordinary species in the genus Pseudomonas such as Ps. fluorescens. The dose at D10 value of the strain No. O-l was ca. 0.14 Mrad, which is similar to that of the Micrococcus radiodurans, and that of the strain No. RP-C was ca. 0.06 Mrad in m/15 phosphate buffer.
59 citations
TL;DR: In this paper, the anisotropic threshold energy for atomic displacements and the displacement cascade process in electron-irradiated pyrolytic graphite was studied in the energy range from 1 2 to 10 MeV at three different temperatures by observing the a -axis electrical resistivity increases.
Abstract: The anisotropic threshold energy for atomic displacements and the displacement cascade process in electron-irradiated pyrolytic graphite are studied in the energy range from 012 to 10 MeV at three different temperatures by observing the a -axis electrical resistivity increases The threshold energy T d is represented as \(T_{\text{d}}(\varPsi){=}A\cos^{2}\varPsi+B\sin^{2}\varPsi+C(1-\cos 4\varPsi){\equiv}(A,B,C)\) in eV, where \(\varPsi\) is the angle between the c -axis and the displacement direction In the 6 and 80 K irradiations T d is given as a set of (23, 30, 0) and (31, 30, -2)±2 eV, and the cascade obeys the Harrison-Seitz Replacement model for \(\varTheta{=}0\)°, but obeys the Kinchin-Pease model for \(\varTheta{=}90\)°, where \(\varTheta\) is the angle between the c -axis and the electron direction In the 285 K irradiations T d is either (28, 42, 0)±2 eV, or a set of (28, 42, 0) and (32, 42, -1)±2 eV, and the cascade obeys the Harrison-Seitz (no replacement) model for \(\varTheta{=}0\)°, 30°
45 citations
TL;DR: In this paper, the most probable charge Z p{/ce:inline-formula} observed in the medium energy fission of various nucleides was studied in comparison with the thermal-neutron-induced and spontaneous fission.
44 citations
TL;DR: A radio-resistant Pseudomonas has been isolated from samples of normal unpolished and commercial rice grains and was found to be sufficiently different from all the described species in this genus to warrant it’s description as a new species.
Abstract: A radio-resistant Pseudomonas has been isolated from samples of normal unpolished and commercial rice grains. This species could be classified in chromogenic group of genus Pseudomonas. It’s taxonomic characteristics were found to be sufficiently different from all the described species in this genus to warrant it’s description as a new species and was named as Pseudomonas radiora nov. sp.The radio-resistance of this species was 10 to 40 times higher than that of ordinary species in the genus Pseudomonas such as Ps. fluorescens. The dose at D10 value of the strain No. O-l was ca. 0.14 Mrad, which is similar to that of the Micrococcus radiodurans, and that of the strain No. RP-C was ca. 0.06 Mrad in m/15 phosphate buffer.
43 citations
TL;DR: In this article, the mass-yield curve was obtained for each of the eleven incident energies, and an analysis was performed, based on the two-mode fission mechanism, and the observed total chain yields were reasonably reproduced by the combination of the three Gaussian curves with partial distortions.
32 citations
TL;DR: In this article, the failure was caused by a significant depletion in the chromium content in the weld metal, and the lack in the compositional balance was found to have originated at the overlaying of the first layer on the dissimilar base metal.
29 citations
TL;DR: In this paper, the authors measured the magnetic susceptibility and specific heat of the β-MnO 2 powder specimen in the range 20 to 300°K and 77 to 100°K respectively.
Abstract: Magnetic susceptibility and specific heat of the β-MnO 2 powder specimen have been measured in the range 20 to 300°K and 77 to 100°K respectively. The measurements have also been made for the paramagnetic inelastic neutron scattering at room temperature by using time-of-flight method. The values of the Weiss temperature, of the Neel temperature and of the average full width at half maximum of the neutron energy distribution (Gaussian) have been determined as 1050°K, 92°K and 13 meV respectively. The exchange integrals ( J n ) are determined by combining these experimental data with the theoretical relations between exchange interactions and physical properties and by assuming J 1 / J 2 =1.60: J 1 =8.9 (antiferromagnetic), J 2 =5.5 and J 3 =-1.3°K, where J 1 is the exchange integral between nearest neighbours (in the direction), J 2 acts between next nearest neighbours ( direction) and J 3 refers to third-neighbour coupling.
29 citations
TL;DR: In this paper, the free-ionic polymerization of isobutyl vinyl ether was studied by dilatometry and electrical conductivity measurement, and it was found that a high frequency factor and presumably higher activation energy was associated with a high activation energy.
Abstract: Radiation-induced free-ionic polymerization of isobutyl vinyl ether in bulk system has been studied by dilatometry and electrical conductivity measurement. Some refinements in kinetic treatment of estimate the propagation rate constant kp from the rate of polymerization and steady-state conductivity were attempted. Polymerization of superdried monomer which gave a half-power dose-rate dependence of Rp was carried out at 0, 25, and 50°C. The kp value obtained at 25°C and an activation energy for propagation were estimated as 1.2 ± 0.4 × 105 I./mole-sec and 9.6 ± 2.8 kcal/mole, respectively. In isobutyl vinyl ether, a propagation reaction in free-ionic mechanism was found to be characterized with a high frequency factor and presumably higher activation energy, compared with ion-pair mechanism. Discussions were also made as to several contrasting behaviors between the polymerization of alkyl vinyl ethers and other vinyl monomers as styrene both in free-ion and ion-pair mechanisms.
TL;DR: In this paper, the U-rich phase boundary was obtained as 1.542 of the N/U atom ratio from a tensiometric measurement, and the decomposition pressure of U2N3 was given by log pN2 (atm) = 7.201 −11736/T.
TL;DR: In this article, a dry distillation method was studied for rapid separation of 99mTc from neutron irradiated MoO3 powder in the temperature range of 480°700°C, and its behavior was in good agreement with the bulk diffusion mechanism based on Fick's law.
Abstract: The dry distillation method was studied for rapid separation of 99mTc from neutron irradiated MoO3. Upon heating, 99mTc produced in MoO3 crystal by the 98Mo(n,r)Mo99m β→ 99mTc process was found to be released by diffusion. From observations made of the deposition temperature, it was concluded that 99mTc was present in the form of 99mTc(IV) in the MoO3 crystal lattice and that it was released in the form of 99mTcO2, which, in air, further oxidized to 99mTc2O7. The release of 99mTc from neutron irradiated MoO3 powder was studied in the temperature range of 480°700°C, and its behavior was found to be in good agreement with the bulk diffusion mechanism based on Fick's law. The diffusion coefficient varied with temperature in compliance with Arrhenius' relation, except in the region of temperatures above 700°C. The separation of 99mTc from MoO3 was performed with a yield higher than 80% upon heating for 30 min at 800°C in air. The decontamination factor for 99Mo was consistently found higher than 105.
TL;DR: In this paper, correlations between spacings of arbitrary pairs of neutron resonance levels for intermediate and heavy nuclei are described, and it is found that pairs of levels separated at particular spacings appear very frequently and the observed levels are also preferentially distributed at periodical positions with particular periods.
Abstract: Analysis of correlations between spacings of arbitrary pairs of neutron resonance levels for intermediate and heavy nuclei is described. It is found that pairs of levels separated at particular spacings appear very frequently and the observed levels are also preferentially distributed at periodical positions with particular periods. These correlations are found in the observed resonances of 75 As, 121 Sb, 123 Sb, 146 Nd, 166 Er, 174 Yb, 177 Hf, 234 U, 240 Pu, etc.. It is shown that these regular level distributions are rarely expected for statistically distributed levels.
TL;DR: A method for rapidly analyzing the γ spectrum obtained with Ge(Li) detectors was developed for a medium-size electronic computer based on the first derivative method, associated with a number of peak-shape tests.
Abstract: A method for rapidly analyzing the γ spectrum obtained with Ge(Li) detectors was developed for a medium-size electronic computer. The analysis is based on the first derivative method, associated with a number of peak-shape tests. The effects of data smoothing and of changes in peak width were studied to determine the optimum conditions for spectrum analysis. The resulting computer program was subjected to various quality tests on the predicted values of the peak position and area. The results of the tests showed that the code thus developed works quite satisfactorily. The code requires 10 sec and a memory core of 29 k when using a FACOM 230–60 for the analysis of a 2,047 channel spectrum.
TL;DR: A normal coordinate analysis of the optically active UO and UF lattice vibrations has been made on the basis of a layer model of infinite (UO2)F2]∞ as mentioned in this paper.
TL;DR: In this article, the results of stress relaxation measurements of tungsten crystals are presented above a temperature of about 30°K the relaxation follows the typical low temperature behavior However below 30°k the stress relaxation is temperature independent and time independent, consistent with quantum mechanical tunneling of dislocations.
TL;DR: In this article, a broad-range magnetic spectrometer with a 200 proportional-counter array has been used to measure the Triton spectra of the ground state rotational band with 51.7 MeV protons.
Abstract: The (p, t) reactions on 158 Gd, 164 Dy, 172 Yb, 176 Hf and 184 W have been studied with 51.7 MeV protons. Triton spectra have been measured with a broad-range magnetic spectrometer with a 200 proportional-counter array. The cross sections for the states of the ground state rotational band which have been found to depend on mass number, have been analyzed by the distorted-wave Born-approximation. Especially Y 4 -diformation parameter β 4 for each nucleus has been obtained from the cross section for the 4 + state of the ground state rotational band. The cross sections for the first excited 0 + states have been found to have a mass number dependence and this dependence was compared with the prediction based on the pairing vibrational mode.
TL;DR: In this article, a neutron and X-ray diffraction study was made on the phase transition of U4O9 and U 4O9−y which occurs at a region slightly above room temperature.
TL;DR: In this paper, the effect of the morphological changes on the kinetics of Zr-Ni alloys was discussed in connection with the role of nickel and the dissolved oxygen.
TL;DR: In this paper, a model in which the two modes of fission were independently governed by two different saddles was proposed and the resulting barrier height was found to be specified with two parameters preferentially the mass and charge of the fissioning nucleus, instead of a single parameter as in the case of the asymmetric mode.
TL;DR: In this paper, a scheme for the sequential separation of fission products has been developed on the basis of ion exchange techniques, which consists of a main cation-exchange process for group separation and subsidiary processes of cation or anion exchange for further separations or purifications of the individual Fission products.
Abstract: A scheme for the sequential separation of fission products has been developed on the basis of ion-exchange techniques. It consists of a main cation-exchange process for group separation and subsidiary processes of cation or anion exchange for further separations or purifications of the individual fission products. By the present method, Zn, Rb, Sr, Y, (Zr), Mo, Pd, Cd, Te, Cs, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu and Tb can be separated simultaneously from an irradiated uranium sample. Of these, alkali, alkaline earth and rare earth metal ions are separated quantitatively. A polarographic method was applied to determine the recoveries of Zn, Mo, Pd, Cd and Te, which were not separated quantitatively.
TL;DR: In this article, the relationship between the boron distribution and the radiation effect of 316 stainless steel was studied, showing that the changes in mechanical properties after irradiation were influenced by the bboron distribution in the specimens; ductility losses in specimens in which borons was segregated on grain-boundaries were especially severe.
TL;DR: A solvent extraction study was carried out at 30° with organic phases of tri- n -butyl phosphate(TBP) in dodecane and inorganic phases of molten manganese nitrate hexahydrate (m.p. 25.8°) was also used in a similar way as mentioned in this paper.
Patent•
27 Dec 1971TL;DR: In this article, a method for cross-linking a COPOLYMER of TETRAFLUOROETHYLENE-PROPYLENE is presented. But, the cross-link method is not suitable for a large number of vehicles.
Abstract: 1. A METHOD FOR CROSS-LINKING A COPOLYMER OF TETRAFLUOROETHYLENE-PROPYLENE WHICH COMPRISES SUBJECTING SAID COPOLYMER OF TETRAFLUOROETHYLENE-PROPYLENE, WHEREIN THE RATIO OF TETRAFLUOROETHYLENE TO PROPYLENE IN SAID COPOLYMER IS IN THE RANGE OF 90/10 TO 20/80 TO HIGH ENERGY IONIZING RADIATION IN THE RANGE OF 10**3-10**8 RADS IN THE PRESENCE OF 0.1 TO 20 PARTS BY WEIGHT PER 100 PARTS BY WEIGHT OF THE COPOLYMER, OF A CROSS-LINKING ACCELERATOR SELECTED FROM THE GROUP CONSISTING OF DI-ALLYL AMINE, DIALLYL ETHER, DI-ALLYL MELAMINE, DI-ALLYL SUCCINATE, DI-ALLYL PHTHALATE, DI-ALLYL MALEATE, TRI-ALLYL AMINE, TRI-ALLYL CYANURATE, TRI-ALLYL PHOSPHATE, AND TRI-ALLYL ISOCYANUARATE.
Patent•
28 Jun 1971TL;DR: In this article, a contaminated sodium is advantageously purified by dissolving calcium and magnesium and/or an alloy thereof in a molten sodium containing impurities and cooling the molten mixture to separate the impurities together with the added metal or alloy.
Abstract: A contaminated sodium is advantageously purified by dissolving calcium and/or magnesium and/or an alloy thereof in a molten sodium containing impurities and cooling the molten mixture to separate the impurities together with the added metal or alloy.
TL;DR: In this article, the correlation of the Vickers hardness with flow stress and the ultimate tensile stress was examined over a temperature range which contains the respective ductile-brittle tensile transition point.
TL;DR: In this article, a rapid method for 99mTc extraction into methyl ketone from an alkaline solution of neutron irradiated MoO3 was studied in order to establish a rapid and efficient method for producing 99m Tc.
Abstract: Purification of 99mTc extracted into methyl ethyl ketone from an alkaline solution of neutron irradiated MoO3 was studied in order to establish a rapid method for producing 99mTc.After removal of the organic solvent by evaporation, 99mTc could be purified from remaining traces of Mo and other contaminants by adsorption in an alumina column from an aqueous solution and by subsequent elution with 0.1N HCl or with physiological saline solution.Organic solvents containing 99mTc could also be treated directly in an alumina column to purify the 99mTc: this saved the time required for the evaporation of the solvent.Problems essential to the adsorption of 99mTc on alumina in organic media were studied to determine the optimum conditions for the adsorption.A standard procedure for 99mTc preparation would be: Extract 99mTc into methyl ethyl ketone from alkaline solution. Pass organic phase through cation exchange column to remove Na and then through alumina column. Finally, elute 99mTc from alumina column with 0.1N HCl or saline solution.The process can be finished within 1hr. About 500mCi of 99mTc is obtained with a chemical yield higher than 95%, and the product contains less than 10-4% of radiochemical impurities.