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Volume 27, Issue 4
Displaying 1-12 of 12 articles from this issue
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Tetsuji IMAI1958 Volume 27 Issue 4 Pages 181-189
Published: April 10, 1958
Released on J-STAGE: February 09, 2009
JOURNAL FREE ACCESS -
Yoshiro ITO1958 Volume 27 Issue 4 Pages 190-195
Published: April 10, 1958
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSSome analyses are carried 'out on the axial temperature distribution of cylindrical electrodes of a triode at high temperature, where the imput energy of electrodes is dissipated chiefly by radiation.
The fundamental equations are deduced under the following assumptions.
1: Heat radiation and reflection at electrode surfaces follows Lambert's law.
2: Heat conduction through electrode walls is negligible.
3: Total emissivity of electrode surfaces is independent of temperature.
4: The electrodes are of the same length.
5: The grid is substituted by equivalent imaginary semi-trans parent cylindrical surface of the same dimension as the grid and its transmission is (1-ηg), where ηg is so-called screen factor of the grid.
The equations are as follows.
_??_ where
_??_: Kernel functions of the co-existive Fredholm's integral equations the second kind with parameter rf/rp.
Q(Z): heat energy dissipiated from the surface of the electrode at the ultimate state of mutual radiation heating.
Method of numerical solution of these equations is given, and the results are discussed briefly.View full abstractDownload PDF (408K) -
Yuzo YASHIRC1958 Volume 27 Issue 4 Pages 196-200
Published: April 10, 1958
Released on J-STAGE: February 09, 2009
JOURNAL FREE ACCESSSpecimens of polycrystalline aluminum covered with oxide film formed either at ordinary or elevated temperature are subjected to various modes of elongation. The increase of the surface potential (S. P.) measured at its neck surpasses by far the value theoretically expected. The S. P.-elongation curve for stepwise elongation rises roughly along a parabolic curve with its apex on the right in zigsag which is more accentuated for annealed specimens. When elongated in a single act to fracture by a constant heavy load, the S. P.-time curve rises either in S form to a constant value for not-annealed specimens or to a maximum and then falls off for annealed.View full abstractDownload PDF (335K) -
Jun KUROYANAGI1958 Volume 27 Issue 4 Pages 201-211
Published: April 10, 1958
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSThe effects of cold-work and subsequent annealing on the rigidity of pure silver wire are measured by means of a torsion pendulum. Pieces of silver wires (purity 99.500) of 1 mm in diameter are cold-rolled and cold-twisted to various degrees and heated at a constant rising rate of 1.7°C/min from a room temperature (20°C) up to 520°C in a vertical furnance.
(1) There is a remarkable difference between the temperature change of rigidity of cold-rolled specimens and that of cold-twisted specimens. For cold-rolled specimens, the rigidity-temperature curve shows anomalous changes in the temperature ranges θ1_??_θ2 and θ3_??_θ4. The former change may be due to the re-arrangement and annihilation of free dislocations, and the latter may correspond to re-crystallization. For cold-twisted specimens the former change is not obvious.
(2) The rigidity-temperature curve of unworked or annealed specimen decreases almost linearly at first as the temperature rises, but above a certain temperature it becomes concave to the temperature axis.View full abstractDownload PDF (790K) -
Kamekichi SHIBA1958 Volume 27 Issue 4 Pages 212-215
Published: April 10, 1958
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSA portion of the surface at which the temperature t is to be measured and a cup-shaped cover constitutes a hollow space. The temperature θ of the inner surface of the cover is made to vary by electrical heating. The temperature of the surface is measured by a radiation thermometer through a small hole of the cover. Let the temperature thus obtained be τ. When θ=t, the walls of the hollow space are at an uniform temperature, and then, τ must be equal to t and θ. When θ≠t, it must be t_??_τ_??_θ, and if the temperature difference |t-θ| is small, it must be t-θ=k(τ-θ). Let τ=τ1 when θ=θ1, τ=τ2 when θ=θ2, ••••. The temperature t of the surface of non-black body is obtained on graphs, representing the relations between θ and τ and between τ and (τ-θ).View full abstractDownload PDF (308K) -
Koji KAWASAKI1958 Volume 27 Issue 4 Pages 216-219
Published: April 10, 1958
Released on J-STAGE: February 09, 2009
JOURNAL FREE ACCESSThe effect of water vapour on the ionic conduction along the surface of some materials is studied.
In order to account for the experimental results obtained, the following semi-empirical formula for the region of low adsorption is given: log i/i0=βn where i and i0 are the intensities of current through the sample, adsorbed and unadsorbed respectively, n is the number of adsorbed H20 monolayers and β is a constant.
From extensive data on glass and porcelain that were obtained by the author and on selenium films evaporated on porcelain by R. Serizawa and also on a germanium p-n junction by J. T. Law, it has been revealed that the above expression is valid only for the range where n is less than a certain critical value characteristic to the material tested.
As the number of the adsorbed monolayers increases over this critical value, this linearity between log i/i0 and n ceases to hold, and the surface current increases linearly with n.
This deviation from the above expression at high water vapour pressures is considered to come from the bulk liquid-like phase transition of the adsorbed water, and this transition is discussed by the liquid slab theory of adsorption isotherm introduced by Frenkel-Hill-Halsey.View full abstractDownload PDF (255K) -
Masaharu NAMBA1958 Volume 27 Issue 4 Pages 220-223
Published: April 10, 1958
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSFollowing the author's previous report on the electrical behaviour of silicon carbide single crystal contacts, the case of granular silicon carbide bonded discs is discussed.
These resistors are used as voltage limiters in many kinds of electrical equipment because of their non linear relation between current and voltage. Calculations of the typical characteristics are made for 100φ×25 mm and 150φ×20 mm lightning arresters and 15φ×0.56 mm and 15φ×0.89 mm varistors. In the treatment SiC grains is regarded as a sphere of radius r (0.035mm for arrester and 0.05 mm for varistor) with which the contact area is determined from the Hertz's formula as 1, 2 and 10-2cm2 for 100φ, 150φ and 15φ resistors respectively. In lightning arrester, the restriction voltages at 5000 A and 1500 A are important. According to the author's theory, these are given as follows: for 100φ×25 mm element
V5000A=4400+470δ Volt
V1500A=3700+429δ _??_,
and for 150φ×20mm element
V5000A=3150+327δ _??_
V1500A=2500+295δ _??_,
where δ(10-7cm unit) is the thickness of the oxide film on SiC surface. For commercial resistors δ=2_??_4 must be used. For varistors, if we consider the effect due to carbon content amounting several percent, their Current-Voltage characteristics are satisfactorily interpreted.View full abstractDownload PDF (771K) -
Tetuya ARIZUMI, Totaro HAIDA, Ydichi UEDA1958 Volume 27 Issue 4 Pages 224-228
Published: April 10, 1958
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSMeasurement of electrical resistance of Dumet wire has been carried out, assuming the wire as consisted of parrallel resistances of copper, brass and Ni-Fe alloy. The change of resistance of the wire by heat treatment is measured by means of a double bridge and potentiometer. Results obtained are as follows:
1. Copper weight percent of Dumet wire obtained by the electrical method was in 80 percent agreement with that by chemical analysis.
2. In accuracy the method of electrical resistance is inferior to the chemical analysis due to the effect of heat treatment during drawing process of the wire.
3. Rise in electrical resistance alternated with fall every 10_??_20m over the whole length of 0.4mm wire. The copper content was higher in the middle than in the end portions.View full abstractDownload PDF (394K) -
Yohei WACHI1958 Volume 27 Issue 4 Pages 228-232
Published: April 10, 1958
Released on J-STAGE: February 09, 2009
JOURNAL FREE ACCESSWhen uniaxial single crystals such as A. D. P. and K. D. P. are used for high speed Kerr effect, shutter or electro-optical resonator, both the direction of light and that of electric field must be parallel to Z-axis of the crystal, for which an adequately transparent electrode is needed. “Nesa” glass or evapolated gold film is possible to satisfy this requirement, and in the previous investigation, the author had examined full-coated and grid-patterned gold films which are, however, not sufficiently efficient because of very poor or else unsatisfactory transmission. In this study, paralled slit patterned gold film is examined with the intention of making high speed Kerr effect shutter with the following results.
1. The resistivity of electrode is 1-5ω, which is suited to practical uses.
2. Light loss is 25-50%. Hence, parallel slit patterned electrode is superior to full-coated or grid-patterned electrode.
3. Lowering of apparant break-down voltage caused by paralled slit pattern arrangement is not found
4. Transmission under supplied voltage is relatively high, and is, for example, 85% in (a)=0.4mm, <a>/<l>=0.5, 30% in <a>/<b>=0.15, 9% in (a)/(b)=0.10 respectively.View full abstractDownload PDF (747K) -
Takayuki NAKAGAWA1958 Volume 27 Issue 4 Pages 232-235
Published: April 10, 1958
Released on J-STAGE: February 09, 2009
JOURNAL FREE ACCESSRoyer's circuit (a kind of relaxation oscillator), making use of transistors and an iron core, is an important device as an analog-digital converter. By introducing the nonlinear characteristics of transistor and iron core in analysis, the mechanism of self-exciting oscillation of the circuit is investigated. The analysis seems to be in good accord with experiment.View full abstractDownload PDF (250K) -
Seiji FUKUDA1958 Volume 27 Issue 4 Pages 236-242
Published: April 10, 1958
Released on J-STAGE: February 09, 2009
JOURNAL FREE ACCESSThe crystal growth of Co electrodeposited on electrolytically eched (111), (110), (100) and (311) faces of Cu single crystal is systematically studied by means of electron diffraction. Especially the dependence of the structure on pH of electrolytic solutions and current density (c. d.), and the growth conditions of β-Co (ƒ. c. c.) and α-Co (h. c. p.) are investigated in detail. The main results obtained are as follows.
1) Generally at the initial thin layer, only β-Co of parallel orientation is formed, whereas at larger thickness β-Co of the other orientations and α-Co begin to grow.
2) At low pH and low c. d., the outer face of the initial thin layer is rough on a microscopic scale, but that of thick layer has a tendency to form a fairly smooth surface parallel to the substrate. At higher c. d., the deposits are bounded by {111} planes.
3) {111} twins are formed only in a solution of low pH but not low c.d.
4) The general rule for the orientation of the deposit that <110> β-Co and <1120> α-Co are always parallel to <110> of the substrate is found.
5) α-Co with the orientation which is considered to have been formed as the result of stacking fault on {111} planes of β-Co grown in parallel orientation is not observed.View full abstractDownload PDF (1049K) -
Haruo TATENO1958 Volume 27 Issue 4 Pages 243
Published: April 10, 1958
Released on J-STAGE: February 09, 2009
JOURNAL FREE ACCESSDownload PDF (673K)
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