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Volume 30, Issue 6
Displaying 1-13 of 13 articles from this issue
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Yuzo OMURO1961 Volume 30 Issue 6 Pages 375-388
Published: June 10, 1961
Released on J-STAGE: February 09, 2009
JOURNAL FREE ACCESSDownload PDF (1981K) -
Ichiro HATTORI, Susumu ABE1961 Volume 30 Issue 6 Pages 389-394
Published: June 10, 1961
Released on J-STAGE: February 09, 2009
JOURNAL FREE ACCESSA two-crystal gamma-ray spectrometer reported by Peirson has been constructed. Its performance is about the same as that mentioned in the original report. About 800mg/cm2 of alminum is used to absorb the high energy β-particles. The effect of the absorbers is most remarkable for a radium and fission products from which many a-particles are emitted with r photons. The proportionality of pulse-height to energy is as good as with conventional spectrometers. Photofraction is not much improved because of the backscatter, most of which is within the range of 0.1-0.3 Mev. Hence, the magnitude of the photofraction is not of significance to the system as a whole.
The similarity of relations of Compton differential cross section of an electron and response functions of various size Nal crystals calculated by M. C. Method to γ-energy proves the essential correctness of this method.
The following are proposed for improvement upon the apparatus and the method,
1) the use of internal conversion electrons radiated from Cesium-137 as a measure for the energy scale of γ-spectra for crystals of low atomic number,
2) the use of a plastic scintillator as a substitute for anthracene crystal,
3) the use of electronic relay in Dlace of mechanical one.View full abstractDownload PDF (1161K) -
Isamu OHNO1961 Volume 30 Issue 6 Pages 394-401
Published: June 10, 1961
Released on J-STAGE: February 09, 2009
JOURNAL FREE ACCESSElectric transducer of displacement, for which the Hall effect produced in semi-conductor is utilized, has been devised. A germanium pellet with steady electric current flowing through it is placed in ununiform magnetic field and is made to be moved, the displacement giving rise to Hall voltage variation, its amount depending on intensity distribution of the magnetic field and shape of the pellet.
With due consideration of the effect of current electrodes on short-cutting of Hall electric field, intensity distribution of Hall electric field in uniform magnetic field is derived from Laplace equation. This derivation is extended to the cases of untinifdrm magnetic fields of step and linearly inclined distributions with the shape of the pellet as parameter.
The condition for linearity of displacement vs. Hall voltage is given.View full abstractDownload PDF (597K) -
Akira KOSAI1961 Volume 30 Issue 6 Pages 402-406
Published: June 10, 1961
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSRelation between the quantity of bromine appended in graphite and the residual bromine after debrominating these brominated graphite is investigated and electrical conductivity and its temperature dependence of specimens having various stages of bromination in the range of temperature from 298°K to 105°K are determined.
The results obtained indicate that the increase in quantity of bromine atoms adsorbed by graphite causes a decrease in electrical resistance. The chemically adsorbed bromine forms a compounds) with graphite. Electrical resistance of this residue compound has a minimum at the atomic percentage 0.95 of bromine, and temperature coefficient of electrical conductivity is positive.
Plot of the logarithm of electrical conductivity against the reciprocal of absolute temperature gives a straight line, which is represented by the following equation
_??_
where σ0 and ε are constants of the material, K the Boltzmann constant. It is noted that in the region of concentration of atomic percentage of bromine smaller than 0.95, activation energy diminishes linearly against the logarithm of σ0 but exponentially with the increase of atomic percentage of bromine.View full abstractDownload PDF (434K) -
Mitsuo SATOH1961 Volume 30 Issue 6 Pages 406-411
Published: June 10, 1961
Released on J-STAGE: February 09, 2009
JOURNAL FREE ACCESSNuclear magnetic resonance measurements have been made on proton in aqueous solution of paramagnetic ions by pulse method.
The ratio of spin-lattice relaxation time Tl to spin-spin relaxation time T2 of proton is about unity for Fe++, Ni++, Co++ and Cu++ solutions, however, it is 6.7 for Mn++ solution at about 8600 oersted.
Various methods of measuring T1 and T2 are described; multi-pulse method is used for T2 when self-diffusion of the solution is large.View full abstractDownload PDF (1551K) -
Naoyuki KISHI, Kazumasa KAMATA1961 Volume 30 Issue 6 Pages 411-416
Published: June 10, 1961
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSEffects of Co60 γ-ray irradiation on polymethyl methacrylate (PMMA) are studied with the following results.
(1) So far as the decrease of molecular weight by irradiation is concerned, no difference is detected between the effects on stressed and unstressed PMMA.
(2) Mechanical properties of PMMA depreciate rapidly when irradiated with dose of above 3×106γ and when the degree of polymerization falls below 1500.
(3) Glass transition temperature Tg of irradiated PMMA becomes lower with the increase of dose. The relation between Tg and the molecular weight _??_v is expressed empirically as
1/Tg=2.85×10-3+0.333×101×1/_??_v, (1/°K)
(4) In the two cases of PMMA being irradiated in vacuum and in air, G-value for main chain fracture is found to be approximately 2.1.
(5) PMMA, irradiated with dose of 107_??_108γ, swells with bubble formation when heated even after stored for 2 years and 2 months at room temperature. The swelling seems to be due to gas generated not only during irradiation but also by heating.View full abstractDownload PDF (1916K) -
Hidenori HIROSE, Kenji TSUGE, Yasaku WADA1961 Volume 30 Issue 6 Pages 417-423
Published: June 10, 1961
Released on J-STAGE: February 09, 2009
JOURNAL FREE ACCESSElongational creep test is carried out on printing paper and cellophane with varied applied loads and contained amounts of moisture. For paper, anisotropy of creep is studied.
Three types of elongation are observed: instantaneous elongation Ji, retarded elongation J, and plastic flow Jƒ. Ji is proportional to the applied stress and is perfectly recoverable. Jr increases first rapidly, then slowly and reaches a steady value after a sufficiently long time. This steady value is approximately proportional to the applied stress. Jr is observed only when the specimen contains moisture more than the critical amount (ca. 3% for paper and 5% for cellophane). Jr takes place only under the stress beyond the yield value and increases proportionally to logarithm of time. Cellophane does not exhibit Jƒ within the stress range used so far.
Some presumptions are made concerning possible mechanisms of elongation of these types. Absorption isotherm and moisture dependence of dielectric constant of the samples are presented for comparison.View full abstractDownload PDF (580K) -
Mamoru IKEGAME1961 Volume 30 Issue 6 Pages 423-430
Published: June 10, 1961
Released on J-STAGE: February 09, 2009
JOURNAL FREE ACCESSSome observed results on the growth of germanium single crystals, twin crystals and dendrites grown from supercooled melts by Czochralski method are described.
As to the external shape of single crystals, it is regular hexagonal, square or hexagonal when grown in ‹111›, ‹100› or ‹110› direction respectively from highly supercooled melts. These results are obtained on silicon as well as on germanium. If slowly formed, the crystals will be polyhedral bounded by most highly atom-packed {111} faces belonging to various systems regardless of crystalographic orientation of the seed.
Crystals, grown slowly from a seed crystal with one twin plane parallel to {111} and external faces parallel to {111} and {110}, grow into triangular or diamond-shaped plates. Occasionally however, these crystal plates keep on growing in ‹211› preferred growth direction perpendicualr to the melt.
Crystals grown slowly from a seed crystal with two parallel twin planes grow into triangular plates joined with diamond-shaped plates. Such complex crystal plates with two parallel twin Planes usually keep on growing in ‹211› direction.
If the withdrawal from the melt is made very rapidly in ‹211› growth direction of crystals, the crystals will grow by dendritic growth into long and thin tapes or sheets bounded by well developed {111} flat faces. It appears that the dendritic growth takes place at accute corners formed by two adjacent {111} surfaces in twin crystals, because nucleation occurs readily at corners.View full abstractDownload PDF (5396K) -
Munezo TAKAI1961 Volume 30 Issue 6 Pages 430-435
Published: June 10, 1961
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSThe conventional halide gas leak detector uses heated platinum to yield positive ions by direct contact with halide gas. It has therefore some failings: its use in the environment of explosive or combustible gases is strictly forbidden, and its detection sensitivity is not steady, varying largely with surface condition of the platinum,
The purports of this study are
(1) to establish a method of detection free from these failings (Part 1), and
(2) to improve upon the handiness, a remarkable merit, of the conventional detector (Part 2).
In Part 1, the method used is to introduce a mixture of air and halide gas into a proportional counter and to measure the decrease of counting rate of α particles which corresponds to the halide content. The attaching of electrons to halide gas molecules is found to be the main cause of the decrease of counting rate, and from an empirical formula obtained to be consistent with observed results, coefficient of attaching, η, was found for several electro negative gases, SF6, CCl2F2, C2H3Cl and water vapor. In comparison with their known values of 7), the values found in this work (23cm-1 TORR-1 for SF6, 5.3 for CCl2F2, 1.85 for C2H3Cl, and 0.029_??_0.16 for water vapor) are considered to be appropriate which proves that the empirical formula is reasonable.
SF6 was detected with sensitivity of 3×10-5 TORR lit sec-1, the highest among the tested halide gases. This shows that the detecting method adopted is comparable in sensitivity with the conventional method.View full abstractDownload PDF (1777K) -
Part I: Commercial LampsToshiharu TAKO1961 Volume 30 Issue 6 Pages 436-441
Published: June 10, 1961
Released on J-STAGE: February 09, 2009
JOURNAL FREE ACCESSSpectral profiles of Cd visible triplet lines, 2 5086, 4800, and 4678, emitted by several commercial lamps (Osram type) of various discharge currents, are observed by the use of a pressure scanning Fabry-Perot interferometer. Main results obtained are 1) the half-intensity width of each line increases linearly with discharge wattage (or approximately with current) from 23 to 37 VA (or from 1.0 to 1. 5A) by Toshiba lamps, and from 40 to 52 VA by Osram large lamps. Observed curves of each line are nearly identical for all lamps; 2) the rate of increase of the half-width is smaller in the order of λ 5086, 4800 and 4678. The line λ 5086 of many lamps undergoes self-reversal even when the lamps are used in the state of normal discharge. 3) the hyperfine structure of each line is analyzed through data obtained with a narrow spaced interferometer. Observed values of the satellite separation and the intensity ratio are in good agreement with those reported by Schrammen and by Imaizumi.View full abstractDownload PDF (1365K) -
Akira KINBARA1961 Volume 30 Issue 6 Pages 441-445
Published: June 10, 1961
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSInternal stress of gold film (400_??_1300Å) evaporated on a quartz disk (18mmφ×0.2mm) in vacuo (7×10-5mmHg) is determined by measuring the bending of the substrate for which Newton's ring method is used.
The relation between the mean stress F0 and the film thickness d is found to be
F0=Ad+B (1)
where A=1.9×106 dynes/cm2 Å and B=1.3×109 dynes/cm2.
This relation suggests that the property of the film is inhomogeneous in the directon of the normal to the surface. The stress F is considered to be a function of x, the distance from the substrate surface along the surface normal. From eq. (1), F(x) is determined as
F(x)=2Ax+B (2)
If, according to Hoffman, the stress is caused by lattice defects, Eqs. (1) and (2) mean that
1. As the film becomes thicker, the defects becomes denser. This is supported by the anneal. ing experiment.
2. The part of the film close to the surface contains more defects in comparison with that close to the substrate.View full abstractDownload PDF (1596K) -
Part II: Deformation of Plastics in Frictional ProcessKyuichiro TANAKA1961 Volume 30 Issue 6 Pages 446-456
Published: June 10, 1961
Released on J-STAGE: February 09, 2009
JOURNAL FREE ACCESSState of contact between a glass hemisphere and a flat plate of plastics in frictional process is studied on cinematographical and short exposure photographs of Newton's rings observed at the contact region.
With soft plastics, shape of the contact area varies and the area becomes smaller as the tangential force applied to the contact region is increased. The frictional force is closely connected with the contact depth, and the variation of the depth due to retarded elasticity plays an important part in stick-slip behaviour of friction.
In sliding, the shape of contact area at the front is semi-circular. The smallness in size of contact area at the rear in comparison with that at the front is explained by retarded elasticity which is dealt with theoretically. At high speed of sliding with heavy load, the shape of contact area at the rear is elongated to the rear. If the shapes of contact area under different loads are similar, it seems that the contact area A relates to the load W as A∝W2/3.View full abstractDownload PDF (2570K) -
Fusao TATIBANA1961 Volume 30 Issue 6 Pages 457-458
Published: June 10, 1961
Released on J-STAGE: February 09, 2009
JOURNAL FREE ACCESSDownload PDF (1024K)
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