岡山大学工学部
Acta Medica Okayama
0475-0071
21
2
1987
Automatic Mesh Generator For 3-Dimensional Finite Element Analysis
47
63
EN
Takeo
Taniguchi
The aim of this paper is to propose new automatic mesh
generator for the finite element analysis of threedimensional structures consisted of plates and beams.
The strategy of the proposed one is as followings; Firstly, subdivide the structure into two-dimensional and one-dimensional structural components. Secondly, generate mesh pattern for each of them, and finally combine them so that they reconstruct the original configuration. By using the proposed method the modeling of, for example, steel bridge structures for Finite Element Analysis is easily and also fastly completed. Some examples of the application of the proposed method are presented, and from the examination of the results further important informations for the design of better method are also given in this paper.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
10
1
1975
ERRATUM
61
EN
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
21
2
1987
Some Remarks on Finite Element Mesh Modeling of Crack-Tip Area
31
45
EN
The aim of this paper is to present some remarks on the
arrangement of finte element mesh modeling of the area
adjacent to the crack-tip which locates in two-dimensional
area. Since the stress distribution near crack-tip is singular, the arrangement of mesh pattern and the selection of mesh type in the crack area govern the accuracy of the solution. This paper gives some informations on the arrangement of finite elements in the area which are obtained through numerous number of numerical experiments. And the effectivity of Zooming Technique for stress analysis is clarified through the
experiments.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
21
2
1987
Car Ownership in Households
21
30
EN
Car ownership in households is analyzed by disaggregate behavioral modeling technique. Two models are built to analyze characteristic features of car ownership. The results are (1) The number of driver licenses in a household is, as a matter of course, most influencing on car ownership and multi-ownership. (2) Family size is the second most influencing. (3) Utilily obtainable by owning second or third car is higher in the household of primary industry than that of the other industry. (4) Inclination of household to be car owner is stronger in a sparsely inhabited zone than in a densely inhabited.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
21
2
1987
Influence of Sewage Treatment System on Water Quality in Kojima Lake
9
19
EN
This study dealt with the characteristics of hydrodynamics of Kojima Lake and the influence of a regional sewage treatment system in construction on the lake. Clockwise and anticlockwise circulations are caused by seasonal winds in summer and winter, respectively. The distribution of a conservative material continuously discharged off the shore of the sewage treatment plant is scarcely affected by seasonal winds and river discharges. The sewage treatment system improves the water quality of the lake except T-N.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
21
2
1987
Depth Dependency of Hardness Change of Ti-Mo Alloys
1
7
EN
We investigated the effects of resolved interstitial oxygen or nitrogen atoms and of quenched-in strain on the hardening of the single crystals grown from molten Ti-14 and 20wt pct Mo alloys. The aging treatment at 623K in atmosphere much more increased in the hardness of specimen surface than that in argon atmosphere. The quenched-in compressive stress enhanced age hardening due to omega formation. We surveyed in detail the hardness changes toward the center of plate-shaped single crystal.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
21
1
1986
Dynamic Behavior of Sand Bed around Structure under Wave Motion
81
91
EN
Under the attack of storm waves, there are many destructions of coastal structures due to scouring, sinking and sliding. These types of destructions are
considered to be in close relation to the dynamic behavior of sand bed around the structures. In this study the characteristics of pore water pressure and stresses in the sand bed around a breakwater under the attack of superposed waves are treated theoretically. The results show that during the crest or the trough being in front of the structure the strength of sand bed around the structure decreases notably and the unstable zone will occur.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
21
1
1986
Determination of Coefficients of Groundwater Flow in Multilayered Aquifers
71
79
EN
It is difficult to determine the coefficients of groundwater flow from the data which were obtained from the
drawdown test in a multiaquifer system. In this paper, new methods of analyzing drawdown-tests are developed and illustrated with the example to determine aquifer coefficients. In a double-layered aquifer, the analytical solution of drawdown test, in which water is discharged from both layers, is derived. And also the theoretical solution to determine the coefficient of storage by using an index of elasticity of a confined aquifer is derived.
From these solutions, methods of determining the coefficient of transmissibility in a double-layered aquifer
and the coefficinent of storage in a confined aquifer are
got. The example analysis to determine aquifer coefficients
is shown. As a result, the characteristics which were
obtained by these methods are verified by the real drawdown
test data.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
17
2
1983
Estimation Method of the Optimum Relaxation Factor for the Successive Overrelaxation Method
31
46
EN
New estimation method of the optimum relaxation factor for the successive overrelaxation method (SOR) is proposed, and the efficiency of the new method is surveyed through a number of numerical experiments. This method can a priori determine the value of the factor by using only the topological properties of the problem, and it is valid for a sparse set of linear equations obtained by using the five-point difference scheme for any rectangular area with arbitrary boundary conditions. The experiments clarify that the method can estimate good approximate value of the factor.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
21
1
1986
Prediction of Shrinkage and Creep of Concrete
57
70
EN
New prediction equations of shrinkage and creep of concrete are proposed, and the efficiency of the new
equations are investigated through a number of experimental
data. Furthermore,the characteristics and applications of the prediction equations presented in the codes of many countries are also discussed. The results showing that the new equations could estimate shrinkage and creep of concrete within a certain measure of accuracy were obtained.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
21
1
1986
Charge Density Fluctuation in Ionic Mixtures
45
55
EN
The total charge fluctuation spectrum of ionic mixtures is analyzed on the basis of the solution of the hypernetted-chain equation for the binary ionic mixtures. A simple but sufficiently accurate scaling law in the domain of intermediate coupling is obtained and the result is applied to the calculation of the bremsstrahlung emission and absorption rates in high density plasmas composed of ions of many species.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
21
1
1986
Surface Properties of Classical One-Component Plasma
31
43
EN
Surface properties of classical one-component plasma are investigated by numerical experiments on the system with periodicity in two directions perpendicular to the planar surface. The density profile, the electrostatic potential, the electric field, and the surface energy are obtained for intermediate values of the coupling parameter of bulk part r and compared with earlier experiments on spherical system. For r=10, the surface energy is almost the same as earlier result. For r =1, however, the surface energy is
reduced about a factor of 2. The consistency of experimental values of the potential with the exact relation is checked and necessity of large system size is pointed out.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
21
1
1986
A Computer Program of Assembly Line Balancing Considering the Performance Rate of Each Work Station
17
30
EN
Assembly line balancing is to assign work elements to serial work stations so as to make the work content at each station as close as possible to one limiting cycle time or pitch time, i.e., an upper time limit over every station. Until now, it is usually assumed that the
performance rates of work stations are constant. But in
practice the performance abilities of workers, machines or robots are varied by their own working conditions. Then the actual station times are different from standard ones, and consequently the line balance may diminish in many cases. Therefore in this paper, we propose an improved
balancing method, in which work elements can be assigned to the work station having the upper time limit changed by its performance rate or ability. Further we develop the computer program of the proposed method and provide an illustrative problem and computational results. In an application of our method to the practical problems, it is shown that the actual efficiency of the production line becomes near that planned.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
17
2
1983
Transmission Distance and Bit Rate in an Optical-Fiber Multi-Level PCM Transmission System
15
29
EN
Optical-fiber multi-level PCM transmission system is
investigated on the transmission distance and bit rate. A communication channel is established as follows: a light signal is modulated in intensity with a completely-balanced M-Ievel code at a transmitter, and is propagated over an optical glass fiber, and is demodulated at a receiver where the signal with an additive noise is processed through a PD, an equalizing amplifier, a matched filter, (M-l) comparators and a decision circuit. The relative power of the noise from the amplifier is increased in accordance with the reciprocal of fiber's transmittance, where shot noise and thermal noise are smoothed and decreased in power by the matched filter. The relation between the BER and the SNR leads the transmission distance. The product of the transmission distance and bit rate takes the large maximum at the large values of SNR and M. The large value of M is suitable for low-speed and high-rate system, and the interference system.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
21
1
1986
Analysis of Brushless-dc Motor Drive System Taking Account of a Load
1
16
EN
In the power converter of ac drive system the switching behavior of semiconductors causes the distorted voltage and current waveforms, thus the drive characteristics are affected by them. It is, especially, an essential problem that the distorted current waveforms induce the torque ripple. It is assumed in the previous analysis that the input voltage of inverter is a ripple-free dc one. In industry, however, the input voltage of inverter is gained by rectifying the ac voltage. The torque ripple is caused by not only the behavior of inverter but also the behavior of converter. It is required to develop the analysis taking account of the both behaviors. In this paper, the analysis of brushless-dc motor drive system is proposed taking account of the ac supply, power converter, motor and load. This analytical method is the most suitable one for the analysis of practical system. The effects of factors, e.g. filter constants, inverter frequency, phase
relation between ac supply and inverter cycle, load and inertia on the speed variation are revealed by this analysis. Further, the decision of filter constants is
discussed from a view of speed variation.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
17
2
1983
Computer Aided Design of Thyristor Phase-Control Circuits
1
14
EN
The paper presents the computer aided design (CAD) method, the program, the design and the experimental results of inverse parallel thyristor phase control circuits. The calculated values agree well with the measured. The CAD program contains the next two methods which are inquired carefully by authors, such as (i) the optimization by SUMT (Sequential Unconstrained Minimization Technique) method, and (ii) the combined use of the gradient and the cramp calculation methods.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
20
2
1986
Two-Dimensional Automatic Mesh Generator for Finite Element Analysis
55
66
EN
In this study a new automatic mesh generator for 2- dimensional finite element analysis is proposed, and its effectivity is surveyed through a number of test examples. Proposed one is for a micro-computer, and the program is written in BASIC. The user needs no preparation for making finite element model in advance. All of the neccessary informations are displayed on CRT display and its user may answer for questions. It is expected that the cost neccessary for preparing the input-data for finite element analysis is largely decreased.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
17
1
1983
Preparation and Dielectric Properties of [Ba,Sr]TiO(3)-Al(2)O(3)-SiO(2) Glass-Ceramics
97
105
EN
A series of ferroelectric glass-ceramics was elaborated by the controlled growth of Ba(1-x)Sr(x)TiO(3) crystal particles in the glass system 60[Ba(1-y)Sr(y)]TiO(3)-10Al(2)O(3)-30SiO(2)(0≦y≦0.2) in molar basis. Analysis of crystal
phases by X-ray diffraction revealed that Sr content in Ba(1-x)Sr(x)TiO(3) increased with increasing content of SrO in glasses by its preferential transfer into the crystal phase, and the appropriate temperature for the crystal growth was 1100°C. Curie temperatures of glass
-ceramics shifted to lower temperature with increasing SrO content in the crystal and comparatively high dielectric
constant was obtained at room temperature for a glass-ceramics with y=0.2. Frequency dependences of dielectric constant and loss tangent were examined in the frequency range from 1 K to 1 M Hz.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
20
2
1986
Inflow Control on Expressway Considering Traffic Equilibria
47
53
EN
When expressway and roads coexist, it is necessary to establish a reasonable traffic share between them. It may be practiced by the regulation of toll-rate of expressway. But at an occasional traffic congestion, the reasonable share is disturbed, so that some traffic control means should be taken. In this paper, we deal how to control inflows on expressway, from a viewpoint of the optimal share between expressway and roads. The minimization of total travel cost in a system is aimed under traffic equilibrium conditions. The problem is formed as a two-stage programming model, and a simple example solving the problem is showed.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
20
2
1986
Dynamic Behavior of Sand Bed under Oscillating Water Pressure
35
45
EN
Under the attack of storm waves, there are many destructions of coastal structures in the forms of sinking and sliding. These types of destructions will be in close relation to the dynamic behavior of sand bed around the structures. From this point of view, in this paper, we investigate the characteristics of the pore water pressure and effective stresses in the highly saturated sand bed under oscillating water pressure theoretically. The results indicate that the oscillating water pressure induce the notable drop of strength of sand bed around the structure under certain condition.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
17
1
1983
Estimation of the Number of Iterations for Detinite Convergence Condition by Use of the Gauss-Seidel Method
81
96
EN
In this investigation the estimation method of the number of iterations for definite convergence condition by use of the Gauss-Seidel method applied for a set of linear equations which is obtained from the finite element analysis (or the finite difference analysis) of any rectangular area subdivided into N*M is proposed. Though the
number of iterations can be obtained by using the eigenvalue of the governing equations, the proposed method does not require the eigenvalue but only the values of Nand M. Numerical experiments on this estimation method clarify
that the estimated values are within the error bound of 10%.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
17
1
1983
Optimal Toll Rate and Expansion of Urban Expressway
73
79
EN
Some extension is made of the previous papers of the same title in order to investigate (1) what aspect consumers' surplus has according to the characteristics of inverse demand curve and (2) where the maximum consumers' surplus is reached in an equilibrium of toll revenues and cost.
As for (1) three kinds of inverse demand curves are assumed in general form. The marginal consumers' surplus to expansion of expressway network is proved to be of definite sign (positive or negative) or equal to zero according to each curve assumed. For each of curves, the region where consumers' surplus finds its maximum is also shown on the expressway users ~ network expansion plane.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
17
1
1983
Effect of Displacement Method on Sand Bed Liquefaction under Oscillating Water Pressure
61
71
EN
In this paper the liquefaction of sand bed under oscillating water pressure are treated as a basic study of the prevention works against the scouring around the hydraulic structures. The results of the former resurch show that the occurrence of the liquefaction depends on both properties of the oscillating water pressure and of the sand layer. Considering the latter properties, that is, the resistivity against the liquefaction increases with the increase of the permeability of the sand bed, we propose the displcement method as one of the prevention works, which is a method to displace the upper layer of the sand bed by the sand with large permeability. The effects of this method are investigated theoretically and experimentally. By the experimental study, it is shown that the proposed displacement method has the apparent effect to
prevent the liquefaction. The experimental results are explained fairly well by the theoretical analysis based on the theory of the flow through the elastic porous media.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
20
2
1986
SAXS from the GP Zones in Al-4mass % Cu Alloy at Initial Stages of Ageing
21
33
EN
Masuo
Yamada
Mutsuo
Ohta
Akira
Sakakibara
A series of small-angle X-ray scattering photographs with monochromated and point focussed copper Ka(1) radiation was taken of a single crystal of an Al-4mass % Cu alloy at the as-quenched state from 823K and at successive stages of ageing at 313K. The crystal was so oriented that the incident direction of the radiation was along [001] axis, and was cooled with liquid nitrogen during the exposure.
The pattern of the as-quenched state was homogeneous, but
each of the patterns of the aged states consisted of streaks along [100] and [010] directions and a quasi-ring around the trace of the incident beam on the film (even at the shortest ageing time. l6sec). The most intense regions were found in [100], [010] , [100] and [010] directions on the ring. With the progress of the ageing the streaks and the ring became more intense and narrower. The results can be interpreted from points of view of the formation of the GP zones parallel to {100} planes ab initio, the effect of the inter-particle interference on scattering of X-rays, and the growth of the GP zones with the ageing. Guinier
radius of the GP zones at each stage can be obtained from intensity change along [110], and the values are reasonably consistent with those obtained from the cross section of the streak. The presence of multi-layer zones, besides the one-layer ones, is suggested from the humps found on several intensity curves along [100] at later stages.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
17
1
1983
Off-Line Stereo Plotting by Means of Image Correlation
41
60
EN
The algorithm of automatic stereo plotting by iterative image correlation from aerial photographs and the corresponding empirical tests are described. The algorithm is oriented to off-line process, using a image scanner and a general purpose computer, and consists of 3 hierarchical correlation steps, based on one-dimensional matching using usual correlation maximum. For the correlation calculation, the FFT is effectively used. Though some defects exist in the algorithm at present, close contour plotting to middle scale maps is available except in hilly regions, in which marked features in ground covers do not exist.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
17
1
1983
Analysis of Three-Phase Thyristor Phase Control Circuit with Series RLC Elements
15
40
EN
An ac phase control circuit by thyristor is widely used in industry, The characteristics of the singlephase circuit with series RLC elements are numerically analyzed, and is reported the interesting phenomenon of step-up voltage without transformer. However, the performance of three phase phase control circuit with series RLC elements is not made clear. In this paper, the performance of three-phase
control circuit of a balanced and an unbalanced load with series RLC elements is described. The analytical programs with each load are developed, and it is clarified that the calculated by this analytical program agree well with the measured. The calculated results, e.g. waveforms, RMS values of voltage and current, power, and power factor are illustrated and discussed the step-up phenomenon in three phase.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
20
2
1986
Size of Bubbles and Gas Holdup in Bubble Columns
1
20
EN
Bubble columns are extensively used in the chemical industry. This paper evaluates the present state of the art on the size of bubbles from a sieve plate and gas holdup, mainly on the basis of the results of the authors, including previous ones. The size of bubbles formed from a sieve plate has an insignificant effect of chamber volume, and gas holdup shows some different behavior, depending on the hole diameter to liquid depth.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
17
1
1983
Hydraulic Properties of Froth Layer on a Perforated Plate
1
13
EN
This paper deals with the comparison of gas-liquid holdup and froth height on a perforated plate under various operational conditions such as liquid stagnant, cocurrent, countercurrent and crosscurrent gas-liquid flow system.
Tendency to foam is remarkable in countercurrent and crosscurrent flow system. The crosscurrent flow system is suitable for the operation of mass transfer from the point of view of gas-liquid holdup.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
16
2
1982
Finite Element Analysis of Salt Water Intrusion in Nonsteady Seepage
89
99
EN
In this paper are described on the finite element analysis of the nonsteady behavior of interface between salt- and freshwater in coastal groundwater. In order to investigate the validity and the accuracy of this numerical analysis solution, the results calculated by this finite element analysis have been compared with the laboratory model tests. The numerical results showed the very good agreement with the experimental data. Moreover, some applications of this analytical method have been performed.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
16
2
1982
Modifications of an Asynchronous Ring Arbiter
75
87
EN
Some modifications of an asynchronous ring arbiter are proposed. This arbiter is composed of a chain of cells. Each cell has one to one correspondence to a device. In the chain, there exists only one privilege to arbitrate conflicts of requests from many devices. A class of modifications is high speed arbiters, obtained by increasing the number of connecting wires between two adjacent cells. As the results, the time required for the privilege to pass through a cell decreases by about one-half compared with the original arbiter. Another class of modifications is arbiters with priority rules. They are obtained by adding a few hardware to the original arbiter. The priority order of request acknowledgements in all the cells is specified. Using above modifications, conflicts of
requests in many digital systems may be feasibly arbitrated.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
20
1
1985
Continuous Monitoring System for the Wastewaters Having Multiply, Randomly, and Small Effluent Characteristics -Approarch to Analysis of Chemical Oxygen Demand by Complete Flow Process-
45
52
EN
A simple system was developed for the fully automatic and continuous measurement of chemical oxygen demand (COD) in wastewater samples based on colorimetry of dichromate. A sample and a solution of sulfuric acid (1+1) containing 2mM potassium dichromate are continuously pumped with a double-reciprocating micro-pump at each flow rate of 0.3 ml/min. The wastewater sample is filtered at first with a 100-mesh stainless filter and then mixed with the dichromate solution in the mixing joint. The mixture is introduced into a reaction coil made of poly(tetrafluoroethylene) tubing (1 mm i.d., 3 mm o.d., and 20 m length), being placed in an oil bath (120℃). After reaction, the mixture passes into a quartz tubular flow-through cell (10 mm path length, 18 μl volume) in a spectrophotometer, and the absorbance is measured at 445 nm. The COD value of the sample is automatically estimated from the amount of decreased absorbance. The system was successfully applied to COD measurement of some waters, and to continuous monitoring of COD in wastewater of university laboratories. The system was also evaluated by comparing with the flow injection analyzer system previously developed by the authors.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
16
2
1982
EXAFS Study on Local Structure of Iron Crystal by the Use of Asymmetrical Monochromator and PSPC
59
74
EN
The EXAFS spectroscopy equipment constructed from an asymmetrical cut flat monochromator and PSPC is applied to the structural determination of pure α-iron which has small difference (0.038nm) in the first and second nearest neighbour distance. The efficiency of the curve fitting method for the two shell model of known structure material (α-iron) is discussed, in addition to describing the details of the experimental procedure of our new type of spectrometer and of the EXAFS data analysis.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
16
2
1982
Transient Analysis of Two-Phase Induction Motor driven by Voltage Source Inverter with Current Limiter
45
58
EN
In this paper, the analysis of transient performance of two-phase induction motor driven by a voltage source inverter with current limiter is described. The motor is represented by using a two-axis model, that is, the Kron primitive machine. The state equations of mechanical-electrical system are derived. The calculation method with a discrete point of time is employed in order to decrease the CPU time of computer. The calculated results gained from this method agree well with the measured. Then, with the aid of this
analytical method, the discussions on transient performance of this system are also performed.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
20
1
1985
SAXS Intensity Measurements by Photographic Methods
35
43
EN
Masuo
Yamada
Akira
Sakakibara
Mutsuo
Ohta
Photographic method for measurement of small-angl X-ray scattering (SAXS) is improved. Intense pointfocussing incident beam is obtained by using doubly bent crystal monochromator made of aluminium single crystal. Microphotometry and the subsequent calculation to obtain profiles, Guinier and Porod radii, integrated intensities, and so on are facilitated by using microcomputer. Integrated SAXS intensities measured from an Al-Zn alloy which has been treated under the same heat treatment conditions are coincident with one another with probable errors less than ±6 % . Ratio of the integrated intensities obtained from two Al-Zn alloys of different composition is reasonable compared with the quasi-equilibrium phase diagram.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
16
2
1982
Influence of Magnetic Saturation of Iron-Core on Performance of Thyristor Phase Control Circuit
31
43
EN
The influence of magnetic saturation of iron-core on the performance of thyristor phase control circuit with series RLC elements is described. The circuit is analyzed by applying an approximate model of three straight lines to the flux Φ vs. current i curve of the iron-core reactor. And the influence on waveforms, r.m.s. values, power factor and response are discussed.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
16
2
1982
Analysis of Thyristor Phase Control Circuit with Parallel Resonance Elements
17
29
EN
The phase control characteristics in a thyristor phase control circuit with parallel resonance elements indicate very interesting phenomenon. Several extreme values appear on the phase control curve. The phenomenon is different from the step-up one in a thyristor phase control circuit with series RLC elements which is interpreted as series resonance. To comprehend the circuit performance with those loads, it is necessary that the phenomenon on extreme value is physically clarified from other viewpoints. In this paper the performance in this circuit is studied from two viewpoints of a natural oscillation and a parallel resonance. Then, it is found that the performance depends on a natural frequency in thyristor conducting period and a parallel resonance frequency in thyristor non-conducting period. Therefore, the interesting phenomenon on extreme value is affected by the alternative of natural frequency or parallel resonance frequency.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
20
1
1985
On the Adsorptive Force in the Sucking Grasp as the Contact Surface was flat.
21
33
EN
The sucking grasp, for example, the silicon or the rubber sucker has been used widely to handle the parts in various stages of the automated process. But in order to use the sucking grasp more widely, it is necessary to develop the other type of sucking unit. In this paper, we examined the distribution of the vacuum pressure in the contact surface and estimated the adsorptive force from the vacuum pressure, the area of the contact surface, the area or the number of sucking holes, and a gap or a roughness of surface under the contact condition that the flat surface of the sucking unit sucked up the flat surface of an object. The vacuum pressure in the contact surface decreased exponentially, as the distance from the edge of the sucking hole became long. And the adsorptive force was estimated from the equation Y=1.147.P.S.(S/M)(-0.6) in the case of one sucking hole. It is necessary to consider the interaction between two sucking holes which were only separated by a very close distance to estimate the adsorptive force in case of many sucking holes. The adsorptive force became weak, as the gap
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
16
2
1982
A Least-Squares Method for Unfolding Convolution Products in X-ray Diffraction Line Profiles
1
16
EN
A deconvolution method for the X-ray diffraction line profile is proposed, which is based on the conventional least-squares method. The true profile is assumed to be a functional form. The numerical values of parameters of the function assumed are determined so that the calculated profile, which is a convolution of the function and the instrumental profile, has a minimum deviation from the observed one. The method is illustrated by analysis of the X-ray powder diffraction profile of sodium chloride 222 reflexion under the assumption that the true profile is a Gaussian or a Cauchy function.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
16
1
1982
Bandwidth Minimization Algorithm for Finite Element Mesh
147
159
EN
Renumbering algorithms commonly in use for the band solver are generally applicable for any kind of linear equations, and, therefore, we may say that they cann't effectively utilize the characteristics of the finite element mesh. In this paper we investigate the characteristics of the finite element mesh systems, and introduce them into Taniguchi-Shiraishi Algorithm which already introduced some properties of FEM mesh systems. And through several numerical experiments it is proved that this improved algorithm is one of the fastest one.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
16
1
1982
System Dynamics Model on Urban Growth with an Application to Okayama City
125
145
EN
A system dynamics model to forecast future movements of a city was studied. The model consists of three sections of population sector, industry sector, land use sector and some divisions of labor, income employment, housing land which connect each sections. Economic growth rate, public investment program, housing land supply program were incorporated in the model as political variables. The model was applied to Okayama city for thirty years from 1975 to 2005. The results of the simulation are summarized as follows: 1) The drift of peoples into Okayama city will advance in the future. 2) Tertiary industries will be given much weight as compared with secondary industries. 3) Because of the drift of peoples, housing problems will be serious in the future.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
19
2
1985
Galerkin Method to an Integral Equation in the Kinetic Theory
49
61
EN
A Galerkin method is applied to a singular integral equation of fredholm type originated in the problem of the rarefied gas flow over a plane wall. The solution is expanded in a series of the Abramowitz function. The numerical calculations were carried out up to ten-terms expansions. The results show a good convergence of the series.The comparison is made with the previous work obtained by the moment method.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
16
1
1982
Optimal Toll Rate and Expansion of Urban Expressway
105
123
EN
A welfare economic approach is tried to an optimal decision of toll rate and expansion of urban expressway network in an equilibrium of toll revenues and cost of service supplied. The model, originated with Yamada, is such that the decision comes into optimality when the maximum consumers' surplus is reached in the equilibrium condition. The paper is concerned with some general aspects of the optimal solution and reexamination of the solution obtained in the past when used a specific demand curve. General aspects obtained are as follows; The extremum condition to consumers' surplus is equivalent to that to diverted traffic (the realized number of expressway users) only when demand curve has such a property that the marginal consumers' surplus to network expansion vanishes. In case that the marginal consumers' surplus does not vanish, the extrema of consumers' surplus is found in the regions of negative marginal diverted traffic if demand curve yields
positive marginal surplus, and in the regions of the positive if it gives negative marginal surplus. The contact points of demand and average cost curves give extrema of neither consumers' surplus nor diverted traffic. An implicative finding, made out by Yamada by using a specific demand curve, that optimal network expansion is reached when the marginal service cost to expansion averaged to the marginal diverted traffic to expansion is equal to the value of time saved by using expressway just by mean trip length holds good at the points of the maximum diverted traffic, but not at the contacts of demand and average cost curves. In case of the demand curve, the condition for an
equilibrium of revenues and cost to come into existence is that the minimum of the ratio of service cost averaged to the whole population of expressway users to the value of time mentioned above is less than or equal to e(-1).
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
19
2
1985
A Consideration on Convergence Condition of Explicit Finite Element Analysis for Heat Transfer Equation
33
48
EN
This paper treats the convergence condition of the explicit finite element method (i.e. the time and spatial axes are discretized by using the explicit finite difference method and the weighted residual method, respectively) which is applied for analyzing the heat problem in region with complex boundary configuration and also with several material properties. The main role of this study is the application of the Brauer's theorem. As the results we obtain that the usage of the Brauer's theorem is valid and that the application method of the theorem is presented in this paper.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
16
1
1982
Liquefaction of Highly Saturated Sand Layer under Oscillating Water Pressure
91
104
EN
In this paper the vertical distribution of pore water pressure in the highly saturated sand layer under the oscillating water pressure are treated theoretically and experimentally. By the experiments it is shown that the water pressure acting on the sand surface propagates into the sand layer with the damping in amplitude and the lag in
phase, and that the liquefaction, the state that the effective stress becomes zero, occurs under certain conditions. These experimental results are explained fairly well by the same theoretical treatment as for the ground water problems in the elastic aquifer. The main characteristics of liquefaction clarified by the analysis are as follows. 1) The depth of the liquified layer increases with the increase of the amplitude and the frequency of the oscillating water pressure. 2) The increase of the volume of the water and the air in the layer increases the liquified depth. Especially the very small amount of the air affects the liquefaction significantly. 3) The liquified depth decrease rapidly with the increase of the compressibility coefficient of the sand.
4) In the range beyond a certain value of the permeability
coefficient the liquified depth decrease with the increase of the coefficient.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
19
2
1985
Optimal Pricing in Urban Expressway
23
32
EN
A welfare economic approach is applied to investigate some implications of optimal pricing in urban expressway where two different groups of users are supposed to exist. On the assumption of a specified demand function, following implications are shown; (1) optimal prices must be such that the diversion ratios are the same and (2) the price rates must be set equal each other, where the price rate means the proportion of the price to the average user benefit. In connection with the results, the elasticity of the demand with respect to price is measured in Osaka area
of Hanshin Expressway, where two different levels of price are flatly set for users according to the characteristics of their cars.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
16
1
1982
Determination of Diffusion and Dispersion Parameters for Flow in Porous Media
65
89
EN
The purposes of this research is an investigation of the intrusion of sea water into coastal aquifers. For this subject, this paper deals with proposing rational methods of getting diffusion coefficient and dispersion parameter for flow in porous media in a laboratory. These parameters of soil are indispensable in order to apply an analytical approach or a numerical approach to actual salt water intrusion problems. Experimental apparatuses were constructed and test procedures were also developed to measure concentration behaviors in a saturated porous media by using electro conductivity probe. As the results, the diffusion coefficients for the Toyoura standard sand and the Asahi river sand determined by two methods, that is,
"Boltzman's transformation method" and "Instantaneous profile analysis method". The longitudinal coefficient of dispersion for one-dimensional flow was also determined by the least squares curve fitting method with a function of a certain range of seepage velocity.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
19
2
1985
Quasi-random Scanning of a Digitally Controlled Spectrometry
13
22
EN
Ryuji
Koga
Megumi
Kosaka
Hiroya
Sano
A quasi-random method for spectral scanning is proposed to reduce an alias response to a quick change in the source abundance. A direct application is made for an atmospheric methane monitoring with a current-tunable diode laser. Only barrel shift methods are examined being found further vulnerable to drifting etalon fringes.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
16
1
1982
Rectification of Digitized Aerial Photographic Image
47
64
EN
A practical example of digital rectification of tilted photographs using a drum scanning micro densitometer and general purpose computers is depicted. The present research covers rectification of projective distorsions, occuring when the camera axis is not truly vertical, and affine distorsions due to curvature of a drum of a scanner. For this purpose, fundamental mathematical expressions were derived. And some pixel interpolation methods necessary for image reconstruction were compared experimentally. The examples revealed, however, that the film was deformed so complexly that they could not be corrected sufficiently only by affine transformation. Accuracy of rectification was checked by use of stereo aerial photographs in terms of residual y-parallaxes. The result showed residual y-parallaxes of ± 1 pixel (± 50 μm) and sometimes ± 2 pixels were observed. They seem to be caused mainly by film deformations which have not been eliminated, and their amount seems to exceed the photogrammetric tolerance.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
19
2
1985
Order-Disorder Transition in Urea-Polyethylene Complex
1
11
EN
The phase transition of urea complexes whose guest components range from n-paraffin to polyethylene was investigated by DSC thermal analysis. The transition temperatures increased with increasing the chain length; the related heats did not change much with the chain length. An X-ray powder diffractometry for urea-polyethylene complex revealed that the complex undergoes the same kind of phase transition between orthorhombic and hexagonal as urea-n-paraffin complex. The transition is interpreted in terms of an order-disorder transition with
respect to the orientation of the guest molecule.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
16
1
1982
A Unified Approach to System Data Handling in CAD System for Designing Control Systems
31
45
EN
System data handling in CAD sY8tem for designing control systems is discussed. A man-oriented data description method for a wide sense block diagram and its automatical transformation into the state space description is proposed. This work is a part of CAD system: CADPACS-T which has been under development for designing control systems in our laboratory. The proposal data description for a wide sense block diagram has the following features: 1) to correspond nicety to the block diagram and to be
suitable for a man-oriented expression, 2) to express
even a large scale system compactly by partitioning into
some subsystems defined externally, 3) to be easy to add
/or alter the input-output terminals, parameters or elements, and 4) to need not to assign the connection
relationship explicitly owing to adopting the input-output terminal/line names. Moreover, system data handling in designing the PI controller for an actual boiler system expressed in a block diagram is taken up as an example.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
16
1
1982
Improvement of Etalon-fringe Immunity in Diode-laser Derivative Spectroscopy
21
30
EN
Ryuji
Koga
Megumi
Kosaka
Hiroya
Sano
In a sensitive spectrometry with lead-salt diode lasers, etalon-fringe phenomena often intervene in the measured absorption spectrum. Derivative methods are employed for the purpose of high resolution where the pertaining wavelength is modulated. This paper presents results of mathematical examination on a possible improvement of immunity from the etalon-fringes by choosing the profile of the wavelength modulation.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
19
1
1984
Evaluation of Three Flow Injection Analysis Methods for the Determination of Chemical Oxygen Demand
53
62
EN
Three methods for determining chemical oxygen demand (COD) by means of flow injection analysis (FIA) with potassium permanganate, potassium dichromate, or cerium(IV) sulfate as oxidant, developed in this laboratory, are described from the point of view of their operating properties. The permanganate method is the most sensitive and common, but forms manganese(IV) oxide precipitate which blocks the FIA lines and connectors. Addition of phosphoric acid in the reagent system is, however, effective to some extent in order to avoid blocking the flow system. The dichromate method is the most workable and stable, but produces toxic wastes containing chromium(VI). The cerium method is the most probable because cerium(IV) is the strongest oxidant of the three and less poisonous. The last method with
cerium(IV) sulfate is therefore recommendable to apply to the continuous monitoring of COD in many situation.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
19
1
1984
Preparation and Dielectric Properties of [Ba, Ca] TiO(3)-Al(2)O(3)-SiO(2) Glass-Ceramics
45
51
EN
Succeeding to 60(Ba,Sr)TiO(3)-10A1(2)O(3)-30SiO(2)glassceramics reported in our previous paper, another type
of ferroelectric glass-ceramics was elaborated by the
controlled growth of Ba(l-x)Ca(x)TiO(3) crystal particles in the glass system 60 (Ba(l-y)Ca(y)) TiO(3)-10Al(2)O(3)-30SiO(2) (0.0<y<0.25) in molar basis. Analysis of crystal phases by X-ray diffraction revealed that Ca content in the
crystal phase of Ba(l-x)Ca(x)TiO(3) increased with increasing amount of CaO in glass up to y=0.125, and the composition of Ba(l-x)Ca(x)TiO(3) solid solution was restricted by x=0.225. Curie points(Tc) of the present glasscceramics were independent of the composition of Ba(l-x)Ca(x)TiO(3), however temperature coefficients of Σ were
lowered by the addition of increasing amount of CaO.
Frequency dependencies of dielectric constant and loss tangent were examined in the frequency range from 1 k to 1 M Hz.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
2
1981
Some Theoretical Aspects on Optimal Toll-Rate and Scale of Urban Expressway
165
185
EN
In this paper, the optimal toll-rate and scale of urban expressway is discussed economically. The criterion used is the total surplus of expressway, which is defined as the sum of consumer's surplus of expressway users and producer's surplus on the side of expressway administrator. The total surplus is equivalent to the difference of the value of total saved travel times of expressway users and the total cost required to construct and administrate expressway systems. The flow-dependent travel times is assumed, and traffic demand is induced through equilibrium method. On the other hand, for the management of expressway to be capable, the accounting condition that the fare revenue must repay the total cost should be satisfied. Under this accounting condition, the optimal rate and scale which maximize the total surplus are requested, and their properties are examined. The analysis is practiced for both caces of flowindependent cost function and flow-dependent cost function. One remarkable result is that the maximum feasible scale under the accounting condition does not privide a maximum for total surplus.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
19
1
1984
Error Analysis of Band Matrix Method
33
44
EN
Numerical error in the solution of the band matrix method based on the elimination method in single precision is investigated theoretically and experimentally, and the behaviour of the truncation error and the roundoff error is clarified. Some important suggestions for the useful application of the band solver are proposed by using the results of above error analysis.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
2
1981
Hydraulics and Water Quality in Kojima Bay
147
164
EN
In this paper, characteristics of hydraulics and water quality in Kojima Bay are discussed based on field observations. The main results obtained are as follows. (1) The variation of flow rate in Kojima Bay has periods for 30 minutes to 2 hours. This characteristic is represented by a two-dimensional numerical simulation fairly well. (2) The local distributions of salinity and suspended solids show increase in the direction to the mouth of Kojima Bay. On the other hand, the distribution of COD(Mn) is nearly uniform in the whole area of the bay. Salinity appears to be influenced by river discharge sensitively but suspended solids does not. (3) The vertical distributions of salinity and suspended solids are similar. There are similar points between the cross-sectional average of water quality and surface water quality. (4) The surface water quality seems to be influenced by the variation of velocity.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
19
1
1984
Pore Water Pressure in Sand Bed under Oscillating Water Pressure
13
32
EN
In this paper the theoretical method to analyse the pore water pressures in the sand bed under the oscillating water pressure is developed. In the former researchs the validity of the theoretical treatment for the one-dimensional problem has been verified. However, the one-dimensional treatment is not sufficient to obtain the precise informations concerning the many practical problems. From this point of view, in this study, we derive the fundamental equations for the general three-dimensional sand layer under the oscillating water pressure. The validity of this theoretical method is verified by experiments for the twodimensional problems.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
2
1981
Dissection Method for a Regular Finite Element Mesh
133
146
EN
From the theoretical approach to the fill-in minimization
problem we present one of the optimal vertex elimination process for a regular finite element mesh M (nxn), and through a number of numerical experiments it is verified that the new process model can always lead to better numerical results comparing to other methods presently in use. Since the process here presented cann't give the actual dissections of M but can clarify how the optimal elimination is, the process includes George's Nested Dissection Method and the method by Duff, Erisman and Reid. By this investigation we can conclude that l) the concept of "Dissection" is neccessary for minimizing the number of fill-ins, 2) the location of the dissection lines can be systematically decided even if n of M is odd or even number, and though the interior area of M is dissected as George's Method, the surrounding area of M is rather irregularily dissected, and 3) the model of the vertex elimination process given in this paper is applied to other kind of regular finite element mesh or finite difference mesh, too.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
19
1
1984
On the Bremsstranlung in High-Density Plasmas
1
12
EN
Emission and absorption coefficients of bremsstrahlung by high-temperature partially degenerate electrons are calculated for high-density plasmas where Coulomb coupling between ions is not weak. It is shown that the ion correlation substantially reduces these coefficients.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
2
1981
A General Purpose Simulator for Multivariable Control Systems
119
132
EN
A high speed and high accuracy simulator whose data-handling is light and whose weak stability is assured even for stiff systems is discussed. This work is a part of CAD package : CADPACS-T which has been under development for the purpose of designing control systems utilizing TSS of a large scale digital computer in our laboratory. This simulator realizes high accuracy, high computational speed and high reliability adopting A-stable extrapolation methods to transform into a difference system, a recursive formula of an output interval to solve the difference equation, automatic choice of an optimal step length such that minimizes an predicted error, and evaluating error bounds closely near the actual errors in the point of numerical calculation. Moreover, in the point of data management, this realizes separation of program modules from data, common utilization of data and separation of investigation from simulation.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
2
1981
Dynamical Fluctuation Spectra of Two-Dimensional Classical
Electron Liquids
107
118
EN
The dynamic form factor and the transverse part of the fluctuation spectrum of momentum density are analysed on the basis of the generalized Langevin equation. According to the indication of the result, numerical experiments are extended and it is shown that the transverse fluctuation spectrum contains two kinds of excitations. The frequency moment sum rules are discussed in relation to one of these excitations.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
18
1
1984
Convergence Condition of Explicit Finite Element Method for Heat Transfer Problem
111
130
EN
The convergence condition of the explicit difference method for the heat transfer problem is aiready obtained.
On the other hand, if the problem is formulated by using the weighted residual method for spatial axis, we have no tool to estimate the critical timestep width. In this paper, the estimation method is theoretically presented, and its propriety is examined through a number of numerical experiments.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
2
1981
Lower Bounds for Correlation Energy of Mixtures of Charged Hard Spheres
93
106
EN
A method to obtain exact lower bounds for the correlation energy of one-component plasmas is extended to neutral mixtures of charged hard spheres. Upper bounds for the correlation functions of charge densities are derived. These upper bounds, the semi-positivity of correlation functions, and that of the charge-densityfluctuation spectrum are used to improve upon the known bound due to Onsager.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
2
1981
Accuracy and Etalon Fringe Phenomena in Methane-gas Spectrometry Employing Tunable Diode Lasers
79
92
EN
Ryuji
Koga
Satoru
Nagase
Megumi
Kosaka
Hiroya
Sano
A method to monitor atmospheric gas concentration employing a tunable diode laser is proposed. An apparatus was built and experiments were made. The tunable diode laser employed was of'PbSnTe with its wavenumber about 1200 cm(-1) at a temperature of 77 K. Methane concentration in laboratory atmosphere was measured on the experiments. The inquired gas-density is obtained by a hardwired microcomputer incorporating the measured absorption spectrum over a prescribed range instead of an absorption at a single wavenumber. By this, drift type noises are suppressed. After an analysis based on experimental data, an attainable sensitivity for methane was found to be 1 ppb.m. This value may increase if an etalon fringe interference exists. The natural concentration, about 1 ppm, of atmospheric methane was actually measured with a short optical path of only one meter.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
18
1
1984
Some Statistical Considerations on Window Width and Matching Stability of Images.
101
110
EN
In stereo matching of images, sample cross-covariances are used commonly as a criterion for deciding whether matched points are truly conjugate. Hereupon window width is a serious parameters to dominate matching stability. This paper argues about relation of matching stability with window width in terms of statistical behavior of sample covariances. For simple circumstances of analysis auto-covariances of a single image are considered instead of cross-covariances of stereo ones. First the mean and variance of sample auto-covariances are derived with parameters, window width and positional lag. Secondly they are evaluated from the correlation function estimated on an aerial image under the assumption of ergodicity to observe how they vary according as two parameters vary. From this result a variation factor is proved usefull to estimate appropriate window width.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
18
1
1984
Optical Circuit for Waveform-synthesis with Utilizing both GaAs- and Si-Optoelectronic Switches
91
100
EN
Hiroya
Sano
Ryuji
Koga
Megumi
Kosaka
Ichiro
Wake
This paper presents an optical-waveform synthesizer as one
of the applications of optical bistable devices. This device is advantageous in terms of faster operation in which width of each pulse obtained is down to the order of subnanosecond, because this device employs both GaAs- and Si-optoelectronic switches as photodetector. Optical pulse shaping as a preliminary experiment is also described.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
2
1981
Smoothing of Impulse Noise by Orthogonal Transform
69
77
EN
Electromagnetic impulse noise which is harmful to signal measurement or transmission of information, is smoothed by the orthogonal transform processor. The idealized impulse noise with infinitesimal duration and Gaussianly-distributed amplitude shows the same spectral characteristics as white Gaussian noise. Optimal correlation detector against such noise is easily realized by the orthogonal transform processor. Photoelectric pulse signals disturbed by the impulse noise from the power supply can be well detected through the Walsh waveform analyzer. Also, orthogonally-synthesized signals can be demodulated with firmly-suppressed impulse noise, where both the statistical and instantaneous SNRs are superior to those in the usual PCM transmission system.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
2
1981
New Approach to Short-Range Ordering in GP(2) Zones in Al-3.82wt. % Cu Alloy
55
67
EN
X-ray diffuse scatteing intensity measurement has been carried out for the Al-3,82% Cu single crystal in which GP (2) zones are found. The two dimensional equiintensity contour maps in h(1) h(2) 0 plane are obtained from surveying around several reflections. The diffuse intensity around 2 1 0 reflection, which shows a cross like streak, is carefully examined. Warren-Cowley short-range order parameters, a(i), are estimated from the diffuse intensities around 2 1 0 reflection. The component of the intensities coming from atomic displacements was subtracted from the total diffuse intensity. It is found that the equi-intensity contours after the correction of the atomic displacements shows an anisotropic distribution and the GP(2) zone is an ellipsoid with a modified layer structure.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
18
1
1984
Electrochemistry of Redox Reaction III. On the Kinetic Equations for Chronoamperometry
75
89
EN
A basic kinetic equation of potential-step chronoamperometric current-time curve controlled by the rates of diffusion and electron transfer for a simple one-electron charge transfer reaction was given and various
features of current-time curves were deduced from a
theoretical treatment. The current-time equations for
reversible and irreversible electron transfer processes appear as special cases with limited conditions of the
equation reported in the present paper. And a potential-step chronoamperometric method to determine kinetic parameters from a current-time curve was proposed therefrom. The extension of a basic kinetic equation to more general multistep charge-transfer process was also considered.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
2
1981
On the Formation and Growth of G.P. zones in Al-Zn Alloys above or below the Spinodal Temperature
29
53
EN
Mutsuo
Ohta
Teruto
Kanadani
Akira
Sakakibara
Masuo
Yamada
Measurements of electrical resistivity and intensity of small-angle X-ray scattering and transmission electron microscopy were made on Al-Zn alloys of several compositions. G.P. zones are formed by the nucleation-and-growth mechanism above the spinodal temperature. The nucleus has a critical size for growth. This size becomes larger when aged at higher temperatures. The sizes of the G.P. zones formed by this mechanism distribute broadly, but those formed by the spinodal decomposition do closely. The spinodal temperatures estimated for Al-10.0, 12.5, 15.0, and 20.0wt % Zn alloys are ~95, ~110, ~130, and ~180℃, respectively. The critical temperatures below which G.P. zones are observed in these alloys are ~115, ~135, ~160, and ~210℃, respectively.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
2
1981
Computer Program of Line Balancing under the Multiple Workers in Each Station (LBMW)
21
28
EN
An assembly line with no paralleling of work elements and work stations is called a serial line. The cycle time of the serial line must be at least equal to the maximum work element time. To lower the cycle time beyond the limit and increase the production rate, one may permit the paralleling of work elements or work stations. So in this paper we propose the parallel assignment method for achieving a higher production rate. In this method, work elements are assigned to work stations under the multiple upper time limits which are the products of the various numbers of workers and the limiting cycle time. Further we develop the computer program of the proposed method and provide an illustrative problem and computational results.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
18
1
1984
Electrochemistry of Redox Reaction II. On the Kinetic Equations for Chronopotentiometry
57
73
EN
Basic kinetic equations of chronopotentiometric potential-time curves, in which the equations for reversible, quasi-reversible and irreversible electron transfer process appeared in special cases, were given and a chronopotentiometric method for determining kinetic parameters was proposed therefrom. The method was demonstrated for Fe(3+)/Fe(2+) redox reaction in acidic
aqueous media. The limitations of the method and the double-layer charging effects on the potential-time curve were discussed. The extension of the method to more general electrode processes was also considered.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
18
1
1984
Electrochemistry of Redox Reaction I. On the Kinetic Equations for Rotating Disk Technique
43
56
EN
An equation on the current-polarization voltage
characteristics of single charge transfer redox reaction
on a rotating disk electrode (RDE) was given and a curvefitting method to determine kinetic parameters from an
observed polarization curve was proposed therefrom. The method was demonstrated for Fe(2+)/Fe(3+)redox reaction in acidic aqueous electrolyte on Pt-RDE and the limitation of the method was discussed. The extension of the method to multistep charge transfer reaction was also considered.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
2
1981
Generalized Analytical Program of Thyristor Phase Control Circuit with Series and Parallel Resonance Load
1
19
EN
The systematic analytical method is reqUired for the ac phase control circuit by means of an inverse parallel thyristor pair which has a series and parallel L-C resonant load, because the phase control action causes abnormal and interesting phenomena, such as an extreme increase of voltage and current, an unique increase and decrease of contained higher harmonics, and a wide variation of power factor, etc. In this paper, the program for the analysis of the thyristor phase control circuit with a series and parallel connected load of series R-L-C circuit units, is been developed. By means of the program, the transient and steady state characteristics of the circuit can be calculated and then comparative study of various versions of circuits can be carried out systematically. The usefulness of the program is demonstrated by some numerical calculated examples.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
1
1980
Improved Method for the Flow Injection Analysis of Chemical Oxygen Demand Using Silver Nitrate
111
121
EN
On the flow injection analysis (FIA) of chemical oxygen
demand (COD), silver salt was added as an oxidation catalyst for COD substances and a masking agent for halide to improve operating conditions of the FIA apparatus. Both of a proper concentration of potassium permanganate solution and 6.0 % sulfuric acid solution containing 0.1 % silver nitrate are individually pumped up with respective flow rates of 0.51 ml min(-l) and merged into a carrier stream. A 20 μ1 of sample solution is injected into the flow of sulfuric acid solution at just before the merging place. The sample mixed with the carrier solutions in a reaction manifol(polytetrafluoroethylene tubing: 0.5 mm i.d. x 30 m), is passed through a thermostated bath at 100 °c and led to a flow cell for the absorbance measurements at 525 nm. The absorbances are continuously recorded with time. The peaks in the recordings showed good reproducibility and the calibration obtained at a linear concentration range of 0 - 170 mg 1(-1) COD with glucose as standard. The detection limit and precision confirmed with this method were 5 mg 1(-1) and 0.8 %, respectively. Chloride ion up to 200 mg 1(-1) did not interfere without elimination of a silver chloride precipitate. By the present FIA method, several industrial waste water samples were analyzed at a sampling rate of about 40 samples per hour, and their apparent COD values were compared with those found by the manual JIS method. Both of the methods gave the similar results within an error range from -35 to +5 %.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
18
1
1984
The Apparatus to Measure the Multi-point Critical Flicker Fusion Frequency (MCFF)
33
42
EN
In this paper, we mentioned the apparatus developed to measure CFFs at the various point of the retina. Eleven CFFs measured at the central retina of both eyes (used usually} simultaneously, at the central retina of each eye separately, and at four points of the peripheral retina of each eye were analyzed together and referred to as the multi-point critical flicker fusion frequency (MCFF) . MCFF can be used to estimate the level of cortex activity, since the temporal and nasal parts of each eye are connected to different visual cortexes through the optic nerve. As the apparatus used to measure the MCFF was controlled by a micro-computer, the order of measurements and the calculation were done automatically.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
1
1980
Fundamental Study of the Fill-in Minimization Problem
101
110
EN
In this paper the fill-in minimization problem which arises
at the application of the sparse matrix method for a large sparse set of linear equations is discussed from the graph-theoretic viewpoint and also through the numerical experiments. Therefore, this investigation consists of two parts, and in the former part the author shows, at first, that the elimination process of a sparse matrix is equivalently replaced to the vertex eliminations for a graph obtained from the matrix, and by use of some concepts
in the theory of graph he proves that the vertex elimination process for the minimum fill-in is equivalent to the vertex eliminations for vertices in each subgraph which is obtained by the appropriate dissection of whole graph, and that there are only two types of vertex eliminations through the process. This results in the proposal of a new model of the vertex elimination process. The latter part of this investigation is used for the verification of the results from the theoretic investigation. Through the numerical experiments he concludes that the new model of the vertex elimination process is valid, at least, for a graph like a regular finite element mesh. Furthermore, he shows that this model coincides with Nested Dissection Method which can give the minimum value of fill-in, at present.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
18
1
1984
Finite Element Analysis of Transformer Cores
1
31
EN
The quantitative analysis of localized flux distributions in transformer cores has become easy through the progress of numerical field calculations. In this paper, the effects of core constructions, joint configurations, magnetizing characteristics of materials on the flux distributions are examined using newly developed techniques such as a gap element, an approximate method for solving three-dimensional magnetic fields, the time periodicity finite element method, an efficient technique for treating hysteresis characteristics and so on. A method for the optimum design of transformer cores is also discussed. Main results obtained can be summarized as
follows: (a) The building factor of the core made of higely-oriented silicon steel is larger than that of the
conventional core. (b) The iron losses at joints are much affected by overlap lengths, number of laminations per stagger layer and a small irregularity of the arrangement
of sheets. (c) It is clarified that examinations of the optimum construction of core and the most desirable magnetic characteristics of core material are possible using the finite element method.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
1
1980
Variational Formulations for Electromagnetic Field and Charged-Particle Stream Configurations and Their Linearization
79
100
EN
Yoshitaka
Morikawa
Hiroshi
Hamada
Two variational formulations for electromagnetic field and charged-particle stream configurations, in which both field and particles are described by the field-like variables suited for the problems of electrodynamics, are presented. One of them is directly obtained through slight modifications of Sturrock's original procedure but has a complicated form. The other is obtained through linearization of the preceding one and has a compact form. Both formulations lend themselves to straightforward derivation of the well-known energy-momentum tensor and/or its conservation law. Specifically the latter one is of academic interest because of its compact form. Moreover, as a proof of its practical usefulness the variational principle under the small-amplitude approximation is derived from it, which is known to provide a basis for the study of certain types of instability in plasmas. It is, however, hoped that it will find main applications in the electrodynamics problems concerned with large-amplitude behavior.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
1
1980
Quantum-corrected Hybrid Bohm and Classical Diffusion in a Laser-driven Plasma
61
78
EN
Within the framework of the hydrodynamic guidingcenter
approximation, we have investigated such quantum effects as the diffraction correction and the symmetry effect on the classical version of the particle diffusion coefficient D(1) across a dc magnetic field through the temperature-dependent pseudo-potentials. Analytic results are explicitly given with recourse to the order-of-magnitude estimate of a set of parameters pertaining to a laser-driven plasma.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
1
1980
Fast Spectrometry System with Using Tunable Laser Diode
47
60
EN
Ryuji
Koga
Satoru
Nagase
Megumi
Kosaka
Hiroya
Sano
Basic prohlems are discussed about a local, realtime and very sensitive air-pollution monitoring using a laser diode. The method employs the second derivative spectrometry replacing the incoherent light source and mechanical choppers in a traditional method with the laser diode and a newly developed electronic system. Etalon fringes at this system becomes the dominant noise source and its statistic and dynamical features are to be understood. Numerical examination was done for the optimal width of optical frequency modulation. A very fast measurement of weak absorption spectra became possible by the development of lock-in-amplifiers with finite integration time instead of a low-pass filter. Spectra of methane in 7.6 μm region and a time-dependent spectrum
of the etaIon fringe are shown.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
1
1980
Hardware Design of Digital System with Remote-Diagnostic
Capability
29
45
EN
In this paper, a hardware design of digital systems with remote-diagnostic capability is presented. We consider a method for testing a system T(l) on a module basis with a remotely installed systems T(2). In the testing mode, we set up a system (T(l)-m,m') such that a module m of T(l)
is replaced by an adapter A(1) connected to other adapter A(2) through a telephone line and the corresponding module m' of T(2) is connected to A(2). If the system (T(l)-m,m') can simulate T(1) in the absence of any faluts, then it can test m' under a self test program. The main subject of this paper is to study the conditions of the system to be testable in the above sense. At first, the remote diagnostic network based on the system in this paper, restrictions to the system configuration required to perform such a diagnosis and the operation of the diagnostic system are described. The second, the module structure to make above simulation possible is considered, representing the system configuration graphically. Finally, an example of the adapter is shown and the time consumed to diagnose is discussed. One of our results is that a sufficiently large class of synchronous digital systems with few minor conventions is testable.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
1
1980
Influences of the Skin Impedance as the Interface in Bioelectric Potential Measurement
17
28
EN
In the case of non-invasive measurement of bioelectric
potential from body surface, the influence of the skin impedance has been investigated by using strict equivalent circuits of skin impedances. The relationship between the characteristic of skin impedance and the wave distortion was made clear. Furthermore, in the case of electrocardiograph, the shift potential of indifferent electrode to standard potential was obtained by means of simulation, and the distortions caused by connective resistances of a central terminal and skin impedance were quantitatively explained.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
2
1980
Semiautomated Determination of COD in Environmental Water Samples
119
129
EN
A new method based on the principle of flow injection analysis is presented for the semiautomated determination
of chemical oxygen demand (COD) in environmental water
samples. The method is rapid and continuous, and suitable
for the monitoring of COD in wastewaters. The apparatus
used was simply constructed by parts commercially available
for high performance liquid chromatography. Teflon tubing heated with a boiling water was used as a reactor and simultaneously used for mixing coils and transmission lines. The operating conditions were examined to apply the determination of COD in wastewaters by using glucose as a standard COD substance. The procedures recommended are as follows: Both 4.9x10(-4) M potassium permanganate and 6.7 % sulfuric acid solutions are individually pumped, 20 μl of a sample solution is injected into the flow of the sulfuric acid solution, and then mixed with a mixing joint. The mixed solution is transported to a flow cell
situated in a spectrophotometer fixed at a wavelength of 525 nm, and decrements of absorbance are recorded. The peaks were reproducibly obtained at a concentration range of 10 - 200 mg-COD 1(-1). Chloride up to 1000 mg 1(-1) was not interfered at all. Various wastewater samples were analyzed by the proposed method at a sampling rate of 30 samples per hour, and the apparent COD values obtained were compared with the manual COD ones obtained by JIS method.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
1
1980
Factors Affecting Plunge Grinding Force
1
16
EN
Toshikatsu
Nakajima
Yoshiyuki
Uno
Grinding force has a close relation to grinding inputs such as grinding wheel, work material, interference condition, grinding speed, grinding fluid and machine condition, and therefore varies widely with grinding inputs. On the other hand, grinding force affects significantly grinding outputs which are efficiency and quality evaluated with surface roughness, accuracy, surface integrity and so on. It is important to make clear the relations between grinding inputs and grinding force in order to control grinding outputs. In this paper, from the above point of view, the relations between grinding inputs and grinding force are experimentally investigated. It is pointed out that the normal grinding force, the tangential grinding force and its ratio are determined by the product of speed ratio of work speed to wheel speed and setting depth of cut as for interference conditions, and by the product of square of dressing feed and cutting depth of. dresser as for dressing conditions. Furthermore as for characteristics of work materials, the normal grinding force has a close relation to the yield stress, and the force ratio is related to the
elongation of work material.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
2
1980
Properties of the Amorphous Fe(100-x)B(x) Alloy Prepared by rf-Sputtering Technique
111
118
EN
The amorphous Fe(100-x)B(x) alloys with 18 ≤ x ≤ 42 were prepared by applying a rf-sputtering technique. The chemical composition of the sputtered films was well controlled by varying the area ratio of B plate to Fe plate, which were used as a composite target. The crystallization temperature of the amorphous films linearly rises with increasing of B content up to x = 36, but falls in a composition range of 36 ≤ x ≤ 42. The amorphous Fe(100-x)B(x) films exhibited ferromagnetism in the whole compositions studied in the present work. The internal magnetic field of the amorphous films decreases with increasing of B content, since the charge transfer increases with B atom in the system Fe(100-x)B(x).
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
2
1980
Experimental Study on Determining Unsaturated Property of Soil
73
110
EN
This paper deals with the experimental study of hydraulic properties of unsaturated soil. In treating unsaturated zone, a great deal more data are required than are required for the saturated zone, but these properties of soils must be known to apply the finite element approach to actual groundwater flow problems. The purposes of this paper are to propose a rational basis of getting experimental relationships between prossure head() and hydraulic conductivity(K) and between pressure head() and volumetric moisture content(θ) with "the instantaneous profile method" in a laboratory. An apparatus was constructed and test procedures were developed to measure pressure head and volumetric moisture content by using pressure transducers and low-energy gamma ray attenuation.
The technique of a low-energy gamma radiation apparatus does provide a means for accurate measurement of water content without disturbing the system into which water is moving. Furthermore rapid measurement of water content becomes possible at any position in a soil so that water content changes with time may easily be followed. The tensiometer~transducer system provides a most valuable means of measuring pressure head with rapid response and with provision of a complete record of the pressure head
changes with time.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
2
1980
A Consideration on Physics of Saturated-Unsaturated
Groundwater Motion
53
72
EN
The purposes of this paper are primarily to research on behavior of groundwater flow in saturated and unsaturated zone, and to present the fundamentals of the theory of groundwater flow. This paper discusses the physics of the saturated-unsaturated groundwater motion. Evaluations confirm the early belief that Darcy's law is of the nature of statistical result giving the empirical equivalent of
Navier-Stokes equations. The governing equation of
saturated-unsaturated flow in porous media is derived from the law of mass conservation and from the Darcy's law and Richard's equation of motion and is compared with the Klute's diffusion equation which has been widely used in the analysis of unsaturated flow. As a result; it is concluded that the governing equation has the advantage that can be applied for the whole flow region. Typical boundary conditions are enumerated.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
1
1979
Ozonation of Organic Substances from View Points of Wastewater Treatment
139
150
EN
In this paper, ozonation of organic substances which are found in wastewater is discussed regarding following respects; (1)removal ratios of COD(Cr) and TOC, (2)removal properties, and (3)oxidation products. The main results are summarized as follows. (l)Ozonation quickly removes proteins and amino acids, but mildly polysaccharides and n-saturated carboxylic acids. (2)The initial removal of COD(Cr) or TOC is quite rapid, but, as the reaction continues, it slows down so drasti-cally that one may suspect that it has completed. (3)Starch and albumine are decomposed to the smaller molecular compounds. (4)The COD(Cr) /TOC ratio of each substance which is chosen in this study decreases. This means that ozonation results in the formation of oxygenated fragments of the original molecule-occurs by bond fission or partial oxidation. (5)Proteins are indispensable components in frothing because they are surface active. They are removed by not only oxidation but also foaming, however, the removal by foaming is not so large.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
1
1979
Discharge Coeffi cient of a Sluice Gate Placed at Sudden Expansion of Open Channel
127
138
EN
In this paper the discharge coefficient of a sluice gate placed at the sudden expansion of an open channel is investigated theoretically and experimentally. Lateral and vertical expansions are treated in the study. The coefficients obtained for channels with sudden expansion
are compared with those for the straight channel. For free efflux, experimental results show that the coeffcients for expanded channels are always larger than those for a straiaht one,and that the coefficient for a channel to be fully expanded to both lateral and vertical directions takes about 1.2 times larger value than that for a straight one. For submerged efflux, the coefficient is obtained theoretically by using the efflux model shown in this study. The theoretical results explain the experimental ones fairly well. The coefficient for lateral expansion is always smaller than that for a straight channel. The minimum downstream water depth required to submerged efflux for the expanded channels becomes smaller than that for a straight channel.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
2
1980
System Identification Using Fast Fourier Transform
33
51
EN
Algorithms for system identification applying throughout Fast Fourier Transform (FFT) to the major calculating operations are introduced. It is shown that by using data of about as twice length as system settling time and by truncating the incorrect correlation functions resulting from them, errors owing to finiteness of data can be avoided. It is shown that so as to suppress the effects owing to statistical fluctuation of input data or output noise, superposition of data in frequency domain is effective, and also the damping terms of poles or zeros can be efficiently evaluated by utilizing the phase change of the spectra of the impulse response sequence. The proposed method can be efficiently applied to relatively higher order systems or relatively rapidly time-variant systems because of high accuracy and high speed processing of FFT. Moreover, it needs not to assume the order of the system a priori, and yields a reasonable lower order approximating system in itself.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
1
1979
Transient Flow in Groundwater to Wells in Island Model Aquifer
95
126
EN
In order to apply the numerical method to practical groundwater flow problem in the field, the hydraulic properties must be estimated. In this paper, new methods of analyzing drawdown tests were developed and illustrated with some examples to determine hydraulic properties of aquifer. Drawdown tests sometimes have to be performed near the boundary of the aquifer or in the much groundwater supplied aquifer. In such instances, the assumption that the aquifer is of infinite areal extent is no longer valid. Therefore the analytical solutions of unsteady flow due to drawdown test are derived in the conception of "Island Model" that the shape of groundwater level is fixed by the circular water supply which is equilibrium with the pumping rate. By using these solutions, new methods of analyzing drawdown tests which are performed in a confined aquifer and an unconfined aquifer were given respectively and the effect of influence region was evaluated. The example analysis to determine permeability and storage coefficient were shown. As the results,the propriety of the solutions is verified comparing the analytical results with the drawdown test data taken from a real aquifer project.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
2
1980
Microcomputer Filtering System to Measure Very Small Transmission Loss of Impulsive Signals
23
31
EN
This paper describes a method for measuring very small transmission loss of impulsive signals. The correlative
fluctuations within input and output signals are eliminated effectively by the analog simultaneous differencer. The difference and normal signals are alternately sampled and accumulated by the digitizer and
the microcomputer, that is, the microcomputer 2-channels
box-car integrator is realized. The difference and normal accumulated data are transferred to the personal computer, which calculates the ratio of the difference to normal accumulated data, i.e. the estimated attenuation in nepers. By the experiments of electrical and optical impulse transmissions, the minimum measurable attenuations become respectively 2.7×10(-4)NP and 6.0×10(-4)Np. Even the latter value is the smallest so far as the authors know.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
1
1979
Application of Fininite Element Analysis to Groundwater Flow in Field Problems
61
94
EN
The purposes of this paper are primarily to research on behavior of groundwater flow in saturated and unsaturated zone and to develop the most effective methods for solving groundwater flow problems related to civil engineering practice. The mathematical model provides a finite element solution to two- or threedimensional problems involving transient flow in the saturated and unsaturated domains of nonhomogeneous, anisotropic porous media. Before progressing into the various levels of applications the input data and boundary conditions are discussed and evaluated. To demonstrate the flexibility of the finite element approach and its capability in treating complex
situations which are often encountered in the field, the groundwater flow through sand bank at flood water levels and the flow through aquifer due to an excavation were analyzed. As the results there were good qualitative agreements between the numerical results and the informations received.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
2
1980
A High-powered Optoelectronic Switch with Picosecond Risetime
13
22
EN
Ryuji
Koga
Masami
Ebara
Megumi
Kosaka
Hiroya
Sano
A switch element has been developed so that a kilovolt step voltage should be supplied to a 50Ω transmission line with a subnanosecond rise time. The element is of silicon substrate with high purity and a pair of electrodes is attached by the evaporation process. The switch action is performed by the photoconductivity produced by the laser light pulse. This paper deals with a preliminary analysis, manufacturing processes and experimental results of the
optoelectronic switch. A performance of 320V output with less than 4 ns risetime was obtained with sufficient persistence for more than 2×10(5) pulse shots. This switch was successfully applied to an optical waveform monitor for laser light pulses giving a resolution less than 2 ns.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
1
1979
Absorption Spectrum Measurement for Atmospheric Level Nitric Monoxide in γ-0 Band and Its Density Deduction
55
60
EN
Ryuji
Koga
Keiji
Hirao
Megumi
Kosaka
Hiroya
Sano
An absorption spectrum of γ-0 band of nitric monoxide of
very dilute density was taken. An experimental electronic device showed a distinguishing power of 0.01 ppm through 10 m optical pathlength. By the aid of a data processing based on a principle developed by the authors, this sensitivity does not suffer from coexisting sulfur dioxide, which shares the absorption band with the nitric monoxide.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
1
1979
Behaviors of a Soliton in Nonlinear L-C Lines with Abrupt Parameter Change
39
53
EN
Shigeji
Nogi
Kiyoshi
Fukui
Some behaviors of a lattice soliton in nonlinear L-C ladder lines with abrupt parameter change are investigated. The results of computer and circuit experiments show that in the case of a soliton incident upon the line of larger characteristic impedance and of higher phase velocity in linearized-line-limit, the transmitted wave evolves into larger number of solitons. The experimental results can be well explained by use of both linearization approximation for the line near the junction and the theory by Gardner, Greene, Kruskal and Miura.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
1
1979
Dynamic Switching of Wall-Reattachment Fluidic Device
29
37
EN
Effect of the geometrical configuration of wall-reattachment fluidic device on the switching dynamics, the switching time, and its dispersion, was investigated experimentally by using a large scale model. The results obtained can be summarized as follows: 1) The switching time, its dispersion, and switching probability depend upon the connection of the input to the control port. 2) Effect of the vent and splitter on the jet in dynamic switching is explained commonly by using the margin of a given control flow rate to the switching control flow rate. 3) The switching time ,decreases as input increases, whereas its dispersion remains constant except for small input.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
2
1980
The Analysis of Vocational Aptitude Changing with Age
1
12
EN
The assumption that vocational aptitude changed with age and with the kind of occupation was examined from the tendency of the fitted curve for the score of the aptitude test. 9 vocational aptitudes were measured by the general vocational aptitude test by Japan Labor Ministry. Subjects were 382 male workers (design engineers, turners, welders, can manufacturing workers, and crane operators) of from 20 to 59 years old, and 348 male and female students (junior high school, vocational school, and university) of from 15 to 19 years old. The design engineers' aptitudes advanced along the quadratic curve until 31 years old, but almost all the aptitudes of the other workers fell along the linear curve with age. The design engineers preserved various aptitudes until 52 years old, the turners 44, and the welders, the can manufacturing workers, and the crane
operators 37. The students' aptitudes were equal to those of the workers of from 15 to 25 years old. The workers preserved Spatial aptitude and Numerical aptitude until 45 years old. This could be said in all the occupations here.
Further it was made clear from the micromotion study that the influence of age was caused by therbligs
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
1
1979
Iron Losses of Silicon Steel due to Rotating Fluxes (Inclined Rotating Flux and Distorted One)
15
28
EN
Characteristics of iron losses in silicon steel due to inclined rotating fluxes and distorted ones are described. Iron losses due to rotating fluxes have been measured at various conditions for grain-oriented and non-oriented silicon steels by using an improved thermistor-bridge method. Loss measurements indicate that the iron loss due to the inclined rotating flux is greater than that due to the non-inclined one. However, the iron loss due to the distorted rotating flux is not always greater than that due to the non-distorted one.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
1
1979
Oriented Crystallization of Polyethylene at High Pressure from Flowed Melt
9
14
EN
In the course of the study of polymer crystallization at high pressure, oriented crystallization of extended chain crystals of polyethylene were examined. Molten polyethylene were extruded into a die at a few hundred atm, and follwed by crystallization by high pressure application above 3000 atm. Resulting sample shows chain orientation to extruded direction. Thick lamella nearly a few thousand angstrom, which are typical feature of high pressure crystallization, were observed to be stacked parallel each other. In spite of
favorable condition for crystals to grow to chain direction,
remarkable growth to normal direction to them were also observed.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
1
1979
The Molecular Mechanism of Chain Tilt in Poly (ethylene terephthalate) Fibers
1
7
EN
The molecular mechanism of chain tilt in poly(ethylene terephthalate) (PET) fibers was proposed. The mechanism was considered basing on the ordering process from the cold drawn state of glassy PET. It was confirmed that the direction of maximum contraction on ordering agrees with the azimuth of chain tilt which varies with annealing temperature. In the stacking structure of irregular folded chain blocks of cold drawn PET, the expansion to the chain direction and the contraction to the lateral direction yield the compressive stress and tensile stress r respectively. The stress revealed as the result of the ordering from the glassy structure to crystalline structure can be relaxed by the rotation of the resulting crystallites. Therefore, we can suggest that the chain tilt is caused by the relaxation process of the stress.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
12
1978
A Statistical Analysis of Traffic Accidents in Minor Street Network
129
139
EN
A statistical analysis is applied to find what states of "block" are dangerous from view point of traffic accident. Here, the block is defined to be an area surrounded by some major streets and is feeded by a minor
street network. The accidents under study are those which occur in the whole minor street network. They are grouped into three kinds; pedestrian, vehicle and the gross accidents. And each is classified to three types according to the place where the accident occurs. At the beginning 22 variables are assumed to state a certain relationship of some states of the block with the occurrences of accidents and 12 variables are found significant finally through factor analysis. Further examination has reached several key variables that migth have something significant to cause traffic accidents in the block. The key ones are the number of lanes of street and the number of legs of intersection, especially nearly 2 lanes street and 3-leg intersection, respectively. The case study was carried out on 26 blocks sampled from Osaka City.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
Asymptotic Theory of Rayleigh Problem in Rarefied Gas
249
258
EN
The asymptotic theory of Rayleigh shear flow for large values of time is developed on the basis of the linearized Boltzmann-Krook equation. Asymptotic equations for mean velocity outside the Knudsen layer are obtained by employing the Hilbert expansion. Slip boundary conditions are derived from the analysis of the Knudsen layer adjacent to the wall. A solution of the asymptotic equation is obtained under the slip boundary condition and zero initial condition. Discussions are also made of the flow induced by a slowly oscillating flat plate.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
12
1978
Analysis of Pump Test Data for Partial Penetrating wells
97
128
EN
The solutions of unsteady phreatic flow toward a partially penetrating well in an aquifer of finite thickness are described. Firstly the solution for a confined aquifer is shown. In this case,three methods of analyzing field data with partially penetrating well are given, that is, "Log-Log Method, Log-Log Distance Drawdown Method and Jacob's Method Ajusted for Partial Penetration". By using these methods the hydraulic conductivities and the specific storage of the aquifer may be determined. Secondly the solution for an,unconfined aquifer is shown. In this case, also two methods of analyzing field data with partially penetrating well are given. By using these methods, the anisotropic permeability and the storage coefficient (effective porosity) of the aquifer may be determined.
Moreover in each case, the effects of partial penetration
are discussed and the limits of adapting the Theis' and Jacob's methods are setted. From these analytic results,
some cosiderations are added to determine the anisotropy of permeability and to evaluate the storage coefficient.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
12
1978
Cluster Expansion for Two-Dimensional Electron Liquids
89
96
EN
The pair correlation function and the correlation energy density of two-dimensional electron liquids are calculated on the basis of the Salpeter's Debye-chain type expansion. When the two-dimensional plasma parameter (£=2πne4T-2)
is small, the expansion to the first order gives the correlation energy to the order of (£21n£). It is shown that experimental results in the domain (£<0.5) can be reproduced by taking into account the first and the second order terms in this expansion.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
A GRAPH-THEORETIC STUDY OF THE MINIMUM FILL-IN PROBLEM FOR SPARSE MATRIX METHOD
239
248
EN
In this paper the minimum fill-in problem which arises at the application of the sparse matrix method for linear sparse systems is discussed from the graphtheoretic viewpoint and the author gives some results which can be directly introduced in the design of, so called, the optimal elimination ordering algorithm which gives the minimum fill-in(the number of zeros in coefficient matrix which become non-zero during the elimination process). Through this investigation only graphs are treated instead of the coefficient matrices for linear systems, and the elimination process for a matrix is equivalated to the vertx eliminations for the graph. Then, the results by the theoretical investigation are summarized as following: 1. Optimal elimination for each subgraph which is subdivided
appropriately from whole graph leads to the global optimum.
2. In each subgraph there are only two kind of eliminations. Furthermore, some numerical experiments show the characteristics of the subset of vertices, which subdivide a subgraph from the residual.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
An Adaptive Observer via Optimal Control Law
225
238
EN
This paper deals with the adaptive observer which estimates the states and parameters of unknown system. It is shown that the adaptive observer problem is reduced to the identification of the transformation matrix for an arbitrary designable observer. Moreover, the adaptive process of the unknown parameters is reduced to the linear optimal regulator problem. As the result, a new method is presented to obtain an appropriate adaptive process with good insight. And, in this identification, a linear filter is found to be also useful against noises in input-output data. To achieve high accuracy, a particular nonlinear
filtering can improve SN ratio only in the direction of the unknown vector. Even if SN ratio of input-output data has zero dB, sufficient accuracy can be accomplished within suitable correction time. This design algorithm seems to be rather straightforward and practical. Since input sequence is required to be only sufficiently general, the method
is applicable to on-line identification also.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
12
1978
On the Apparent Activation Energy for Clustering in Dilute Al-Zn Alloys
77
88
EN
Mutsuo
Ohta
Toshinori
Kobayashi
Akira
Sakakibara
The clustering phenomenon was observed when dilute Al-Zn alloys were annealed at temperatures higher than the solvus of the G.P.zones. In this report the apparent activation energy for clustering is estimated and compared with the experimental results. The estimated value of the apparent activation energy for clustering in several Al-Zn alloys comes to 0.51 eV, which is larger than the effective migration energy 0.43 eV of Zn atoms in Al-Zn alloys.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
Longitudinal Properties of Two-Dimensional Classical Electron Liquids
219
224
EN
The dynamic form factor and the dispersion relation of the plasma oscillation of two-dimensional classical systems of electrons with ordinary Coulomb interaction are obtained by numerical experiments in the domain of the plasma parameter 2.24≤√=(πn)(1/2)e(2)/T≤70.7, where n, e, and T are the areal number density, the electronic charge, and the temperature in energy units, respectively.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
12
1978
Fluctuation of the Solute Concentration in Al Rich Al-Zn Alloys
59
75
EN
Mutsuo
Ohta
Teruto
Kanadani
Akira
Sakakibara
Several Al-Zn alloys containing 0.041-4.4 at % Zn were studied by means of measurements of electrical resistivity. The results obtained are as follows : (1) The electrical resistivity increases when the specimen is annealed at temperatures higher than the solvus temperature of the G.P. zones. The increase of the resistivity is due to the formation of fluctuation. (2) The electrical resistivity of the specimen containing fluctuation is dependent upon annealing temperature only and independent of quenching temperature. (3) The fluctuation is formed in very dilute alloys as 0.041 at % Zn at temperatures higher than the solvus temperature of the G.P. zones. (4) The formation energy of vacancy and the migration energy of the Zn atom in the alloys determined by the formation process of fluctuation are in good agreement with those by the formation process of G.P. zones. (5) In spite of the result (4), it seems that the
fluctuation is not the same as the small G.P. zones which are observed in the early stage of aging.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
Lower Bounds for Thermodynmnic Quantities of Classical Ionic Mixtures
209
218
EN
Exact lower bounds are given for thermodynamic quantities of ionic mixtures in the uniform background in d dimensions with three-dimensional (1/r) Coulomb interaction (d=2 and 3) and with d-dimensional Coulomb interaction (d=1, 2, and 3). It is shown that these lower bounds improve upon known ones and give values close to experimental results which are available in the case of d=3.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
A Performance Analysis For An Air-Pollution Monitoring Using A Pulsed Dye Laser
195
207
EN
Hiroya
Sano
Ryuji
Koga
Megumi
Kosaka
The maximally attainable accuracy of an airpollution monitoring system is investigated. The system is composed of a tunable pulsed dye laser as the light source, photodiodes as the opto-electric converter and a low noise electronic signal processor specifically designed by the authors. The extreme value of the accuracy is given in terms of the standard deviation of the attenuation. The value is 3.4×10(-4)[Nep√(pulse number)] for an averaged value for multiple laser shots. Also the wavelength reproduceability of a dye laser was examined, which resulted in that a computer should take a part in the wavelength control in order that this method should be feasible.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
A Notion of Adjoint Spectrum in the Application to Air-pollution Monitoring
181
193
EN
Hiroya
Sano
Ryuji
Koga
Yoshihiro
Tanada
Megumi
Kosaka
This report deals with a notion of adjoint spectrum which is applicable to air-pollution monitoring by using pulsed lasers. Both Raman and absorption spectra of multiple gas complex are linear combinations of the spectra, each of which is specific to a gas species and its magnitude is proportional to the density. An extended formulation of the method of least squares is made in terms of a new notion, adjoint spectra, which visualizes the structure of the numerical filter. Applications of the derived numerical filters to the two methods are shown and features are described about the synthesized filters.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
12
1978
A Driving Method of a Spuare Waveform Inverter Circuit Using Power Transistors
53
58
EN
In recent years, the development of a high power transistor element is proceeding. A high power inverter
circuit using power transistors are finding a good number of applications in induction heating and melting. Turn off time of power transistors occupies 5-lOμs of switching characteristics. A driving method to give base inputs for a half period is widely used for a inverter circuit. But this method has the following defects, the short-circuit current flows through two transistors because the other pair transistors turn on before one pair transistors turn off. So the switching loss is increased, the maximum output and the efficiency are decreased. In this paper, a driving method to give base inputs for the less period as compared with a half period is discussed. Using this method, the foregoing defects is lost and the driving frequency is able to become higher. In addition, it become clear that the square waveform output is given using this method in the case of R-L load.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
12
1978
Behavior of Transistor Switching in AC Chopper Circuit
45
52
EN
In this paper, an AC chopper circuit, using a power transistor, is described which chops the AC voltage with a commercial frequency. The circuit is composed of a diode bridge and a power transistor in series with a load and capable of adjusting the switching frequency, fc, and the time ratio, T=ton/(ton+toff). The switching frequency and the time ratio of the AC chopper circuit depend on switching-times, that is, delay time, rise time, carrier storage time and fall time, especially in the high frequency. The upper limit of the switching frequency (about 150kHz) and the output characteristics of the circuit are investigated.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
A Walsh Waoofonn Analyzer and Its Applications to Filtering of Pulse Signals
163
180
EN
A new waveform analyzer based on the Walsh transform is developed and is applied to a real-time filtering of fast pulse signals, and the linear filterings of time signals through the Walsh transform is discussed. The analyzer converts a solitary waveform during 16 μs into the 16 Walsh amplitude spectra in a hybrid manner: it has the sequency band from 62.5 kzps to 500 kzps. The spectra are parallelly held during 16 μs by analog integrators, while serially displayed by the CRT, and one of them is digitally read out. The spectra of the test waves are measured within the error rate of several per cent. The analyzer is applied to the correlative detection of the photoelectric pulse signals in a gasspectroscopic system using a pulse laser, and there composes the matched filter, which is useful for measuring the signals superposed by Gaussian noises with a high accuracy. For the real-time filtering of fast signals, the arithmetic convolution and the frequency power spectra are approximated using the complex Walsh transform.
These approximations are of practical use in 16 or 32 dimensions. Then, the matched filters for pulse peaking are given by the approximate convolution and by the dyadic convolution.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
Coupling-Network Dependence of Locking Phenomena in Microwave Oscillators
153
162
EN
Kiyoshi
Fukui
Shigeji
Nogi
Masuo
Yamada
Akira
Sakakibara
A unified treatment of injection and mutual phase locking phenomena in microwave oscillators coupled by a network characterized by a Y-matrix is presented. Under certain simplifying assumptions, steady state solutions such as locking frequency and oscillation phase relation are given with emphasis placed on the coupling-network dependence of locking bandwidth. Also, some examples of locking system specified by y(21)=0, Y(21)= Y(12) and y21= -Y12 are briefly discussed.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
12
1978
Parameters for Analysis on Distributed Circuit Properties of Etched Alunimum Oxide Film
29
36
EN
The distributed circuit properties based on pores in the etched aluminum oxide film of the electrolytic capacitor have been analysed by the mathematical equation. This paper proposes the selection and the determining method of the parameters appearing in the analysis.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
Aging and Reversion in Dilute Al-Ag Alloys
133
152
EN
Mutsuo
Ohta
Teruto
Kanadani
Masuo
Yamada
Akira
Sakakibara
Aging and reversion in dilute Al-Ag alloys are studied by means of the measurements of electrical resistivity. Results obtained are as follows: 1) Increase in the as-quenched resistivity is found for a low quenching temperature. This increase may be due to the fluctuation of solute concentration at the quenching temperature. 2) When the fluctuation exists in the alloy, the aging rate becomes slow and the maximum resistivity in the isothermal aging curve becomes small as the vacancyconcentration becomes low. The maximum resistivity becomes large again when the vacancy concentration becomes further lower, and finally the maximum does not appear. 3) These behaviors are explained in terms of the difference in the rate of growth of the G.P. zones in the regions of higher and lower solute concentration induced by the fluctuation and in terms of the change of this difference with vacancy concentration. 4) G.P. zones may be formed by the spinodal decomposition with indefinite surfaces at first, grown to larger ones with difinite surfaces and changed to ordered nzones in the alloy. 5) It is confirmed that G.P. zones are formed by the nucleation-and-growth mechanism also in Al-Ag alloys above the spinodal temperature.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
12
1978
A New Model for Structure of Poly (ethylene terephthalate) in its Glassy State
23
28
EN
A new realistic, structural model is proposed for the glassy solid state of poly(ethylene terephthalate) (PET). The model is considered basing on crystallization behaviors from the glassy state of PET, and in particular including the evidence from the estimation of chain folding energy in this report. When PET is quenched from its melt into the glassy state, irregular folds with lower conformational energy remain in glassy structure and disturb the three dimensional arrangement of the chains connected with the folds. In conclusion, we suggested that the structure of glassy PET is not in amorphous state which is represented by the interpenetrating random coil model, but in frozen metastable state which can be approached from the chain folded structure of polymer crystals.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
11
2
1977
An Investigation on Computational Methods of Traffic Assignment in Road Networks
51
71
EN
In this paper some computational methods of traffic assignment are proposed. At first solutions of traffic assignment by the equal travel times principle used nonlinear programmings are showed. They are a method to approximate by a quadratic programming, a method to use the SUMT transformation, a method to apply Rosen's gradient projection method and a method to apply the conjugate gradient projection method. Through a computational example the efficiency of them are compared.
To decide route flows uniquely in traffic assignment by the equal travel times principle, a method requesting route flows such that the joint probability is a maximum under supposed a priori probabilities is proposed. In case of a traffic assignment in a large scale road network, it is significant to improve the efficiency of route searches. For this purpose a technique of minimum time route search by division of a network is proposed.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
Effects of the Fluctuation of Solute Concentration in Al-Zn Alloys on the Aging at Low Temperatures; II. Electron Microscopy and Measurements of SAXS Intensity
119
132
EN
Mutsuo
Ohta
Masuo
Yamada
Teruto
Kanadani
Akira
Sakakibara
The effects of the fluctuation of solute concentration on the process of aging in Al-10wt % Zn alloy were studied by measurements of the intensity of small-angle X-ray scattering and by electron microscopy. Specimen was quenched from a higher temperature(T(Ql), mainly 300℃) to an intermediate temperature (T(Q2), 110~230℃), held there for a time, quenched again into iced water and aged isothermally at 0℃ or 40℃. Results obtained are as follows: (1) When the specimen was held at T(Q2) for a sufficient time and aged at relatively high temperatue(e.g. Ihr at 125℃ and aged at 40℃), a two-step increasing of both resistivity and integrated intensity was found. (2)
Each of the steps has characteristics of the formation of G.P. zones by the spinodal decomposition. (3) When the maximum resistivity(p(max)) takes a minimum, Size distribution of the G.P. zones, estimated from the difference between Guinier and Porod radii, is much broader than that at p(max) in the usual direct quenching. (4) When the holding time at T(Q2) is long enough, the size distribution at p(max) is as broad as that at
p(max) in the usual case. (5) After a prolonged aging under the condition that P(max) takes minimum, G.P. zones grow markedly and become oblate ellipsoidal with a major axis of about 20nm. (6) These results are consistently understood in terms of the fluctuation of solute concentration at T(Q2) and the change in the concentration of vacancies during annealing at T(Q2). That is, it is considered that these results are due to the difference in aging behavior between the regions of relatively high concentration and the ones of low concentration induced by the fluctuation.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
11
2
1977
Ozone and Chlorine in Wastewater Disinfection
37
49
EN
In this paper, we compare ozone with chlorine regarding following respects; (1)Disinfection efficiency (2)Oxidation power (3)Effects of secondary effluents treated by ozone or chlorine on aerobic microorganisms. Both ozone and chlorine are powerfull oxidizing agents. However,those are greatly different from each other in effects of treatment. Ozone is superior to chlorine in oxidation of organics, perfection of disinfection and effects on aerobic microorganisms. On the other hand, chlorine is superior in disinfection of Coliform group bacteria. Based on these results,it may be concluded that chlorination will be effective in disinfection of effluents which do not contain so much contaminants. However in case of rather highly cotaminated effluents, ozonation will be
suitable.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
11
2
1977
Contraction Coefficients of Underflow Gates with a Vertical Lip
27
36
EN
In this paper the influence of a vertical lip upon the contraction coefficients of underflow gates is discussed.
The coefficients of inclined gates with a vertical lip are investigated theoretically by using the method of conformal mapping. Solutions are obtained numerically for several values of the inclination of gate bottom. Theoretical solutions show that;as the length of a lip
increases, the coefficient rapidly decreases from the value
for the inclined gate, and when the length becomes of the
order of a gate openning,it takes a value to be nearly equal to that for a vertical gate. These theoretical results are verified by experiments.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
Effects of the Fluctuation of Solute Concentration in Al-Zn Alloys on the Aging at Low Temperatures; Ⅰ. Measurements of Electrical Resistivity
95
117
EN
Mutsuo
Ohta
Teruto
Kanadani
Masuo
Yamada
Akira
Sakakibara
Aging process in Al-Zn alloys was studied by the measurements of the electrical resistivity when the alloy was quenched from a high temperature, about 300℃ (the first quenching temperature), to an intermediate temperature, between 110℃ and 230℃ (the second quenching temperature), held at this temperature for a time, quenched again into iced water and aged at a low temperature. Variation of the holding time at the second quenching temperature brings about the variation of the isothermal aging curves. Maximum resistivity of the isothermal aging curve, p(max) , decreases at first, passes a minimum and then increases to reach a stationary value as the holding time at the intermediate temperature increases. It is pointed out that this phenomenon is mainly due to the fluctuation of solute concentration and the vacancy concentration decreasing at the intermediate temperature.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
Computer Program of Line Balancing, Regarding Efficiency and Number of Stations as Variables
83
93
EN
To assign work elements to the work stations in an assembly or manufacturing line, various computer programs have been developed and used. And it does that the number of stations or the cycle time is even given. But in practice it is desirable to obtain the assignment which shows the highest efficiency of line balancing under all possible combinations of the number of stations and the cycle time. Therefore we propose a computer program of the assignment method in which the efficiency of line balancing, Ebb and the number of stations, NN are regarded as variables. In this method the minimum value (EEb) of efficiency and the constant term (d) by which Ebb is reduced are given previously. And for any COmbination of Ebb (EE<Ebb<lOO) and NN (l<NN<Nm : Nm calculated from EEb), the work elements are assigned to work stations, the precedence restrictions being used. Ebb is reduced by d from the ideal value (100) until the assignment to NN is obtained. The efficiency of
the obtained assignment, Ebo is calculated. As Ebb<Ebo<Ebb+d, the calculation is continued until the assignment to NN, which shows the maximum efficiency, is obtained. In this process NN varies from Nm to 1 by 1 by 1.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
11
1
1976
An Analysis of Highway On-ramp Merging by Queuing Theory
31
43
EN
In this paper we deal with traffic behaviours on a section of highway including an on-ramp by means of queuing theory. It is the purpose of this paper to provide the adequate capacity for highway on-ramps, which is useful for the design of on-ramps and the traffic control of highway. The highway on-ramp merging is modeled as a queue
and the system is solved. Then the maximum possible flows for merging from an on-ramp is obtained in a form of an function of through lane flows. The traffic capacity of an on-ramp is estimated from the relation between the average waiting time before merging and the incoming flow from an on-ramp, which is induced by the theory of queues.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
Computer Program for Numerical Evaluation of the work
65
81
EN
We try to evaluate the manual work numerically from a point of view of the homogeneousness and the simultaneousness of both hands using the results of the micromotion study. The weighted coefficient and the balance index are used to evaluate the homogeneousness of both hands. And the simultaneous index is used to evaluate the simultaneous movement of both hands. It is necessary to make a program in order to use efficiently the method to calculate the indexes or the coefficients. Therefore the computer program of these methods is mentioned in this paper.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
11
1
1976
Optimal Control of a Nuclear Power Reactor Core with a Coupled Nuclear Thermo-hydrodynamics Model
19
30
EN
Ryuji
Koga
An optimal control is giyen for regulating power distribution in a nuclear power reactor which has cylindrical geometry. The space dependence of the system is
described by expanding space depenident variables by
Helmholtz modes. Results are obtained through the principle
of optimality and are described by the Riccati-type algebraic equation that the optimal feedback coefficients
should satisfy. Use of an integral equation as the system
equation makes it possible to deal with actual controlling
apparatuses: control rods or rod clusters.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
AC Chopper Circuit with Lagging Reactive Load
53
64
EN
An ac chopper circuit, which chops an ac voltage in a complete cycle for any lagging reactive load, is devised. The circuit is constructed of two ac-switches composed of power transistors and diodes. The load voltage is smoothly controlled by varying the time ratio of ac-switch. Transistors operate in a highfrequency chopping mode, thereby the ripples of the source current and the load current are easily filtered. Furthermore the input power factor of this model is better than that of the thyristor phase control circuit. In this paper, the construction and the driving method of this model are described.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
11
1
1976
Anomalous Electric Fields in n-InSb under High Magnetic Fields. I-Experiment
7
18
EN
An investigation was made of the anomalous electric field in its various aspects in n-type InSb subjected to strong magnetic field at 77K and 273K, which lead to the conclusion that no open contradiction arose between a part of the present observations and the predictions attainable from Yoshida's model of semimetals. There remained, however, the other part of the experimental results unexplained, being rather natural since an inner property
of indium antimonide does not seem so simple comparing with the compensated metals, bismuth and antimony. Especially as for the mechanism of an inversion phenomenon of the polarity of a negative anomalous field at a critical pulse current, we have no available theory to explain at present stage.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
Basic Characteristics of Squarewave Irwerter Circuit with Series R-L Load
45
52
EN
In this paper, the steady state operations of the
squarewave inverter circuit with a series R-L load are
discussed. The circuit consists of transistors and
feedback diodes. The basic equation is derived from its
equivalent circuit. Solving the basic equation with
steady state conditions, the instaneous value of the
load current i is derived. The period t(2) for which the
current flows from the supply to the load and the
period t(l) for which the current feedbacks through diodes
from the load to the supply are calculated from (i), and
the ratio of t(l) to t(2) is illustrated using power factor
of fundamental wave, pf, as a variable. The ratios of
transistor mean current I(tr), diode mean current I(D),
supply mean current I(s) to the load current I are illustrated using pf as a variable, too. In result, each current ratios to I is shown in simple expressione. The load current can be calculated simply using the coefficient reading off the figure. In addition, it becomes clear from the figure that the load current is scarcely influenced by the harmonic voltage in less than 0.8 of pf. The ratio t(2)/(t(1)+t(2)) calculated in squarewave voltage, shows the limit of pulse width control whose out put voltage is the squarewave.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
5
1
1970
An Asynchronous Delay Line for PAM Signal
61
66
EN
An asynchronous delay line for PAM signal having controlled delay capability is proposed. The delay line in a cascaded chain of identical memory cells. Each sample of the sequence of the input PAM signals passes or is shifted in particular cell depending on whether the succeeding cell is empty or not. A cell is composed of two memory capacitors with the peripheral control circuits. In this paper, especially, an example of the circuit for cell is shown and its several characteristics are discussed. At the end, some experimental results are given.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
Numerical Analysis of Oscillatory Combustion Phenomena generated in A Pipe-Type Combustor
1
24
EN
In this paper, is proposed a calculating method for the simulation of oscillatory combustion state, and comparisons between estimation results and experimental ones are carried out. With respect to the effects of geometric dimensions of combustion system, and of fueland air-flow rate conditions on characteristics such as an amplitude of oscillation, its fluctuation, and a frequency, a theoretical analysis presents a correct estimation of the phenomena. By use of this analysis, it becomes possible exactly to estimate the changes which take place in the combustion system. On the basis of the quantitative feature of the theoretical results, the influences of the factors such as ignition lag, wall temperature ratio, and heat transmission on the combustion oscillation are studied.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
10
2
1976
A Study on Non-steady Groundwater Flow in a Semi-confined Aquifer
113
136
EN
This paper deals with the groundwater flow in a semi-confined aquifer causing the phenomena of consolidation and free surface lowering. Since the main effect of consolidation has taken place before noticeable lowering of the free surface, one may solve each phenomenon on its own. The real solution may be obtained by the principle of superposition. However, the solution for lowering the free surface is delayed due to the cosolidation by a certain timelapse, depending on the placecoordinates.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
5
1
1970
Biologically Active Compounds. IV. The Synthesis of α-Arylamino-γ-aryl-⊿(α,β)- and α-Arylidene-γ-aryl-⊿(β,γ)-butenolides.
55
59
EN
The importance of the presence of butenolide groupings in biologically active substances has been recognized increasingly. (1) In our search for new pesticides we have prepared 26 α-arylamino-γ-aryl-⊿(α,β)-butenolides (1-26) and 9 α-arylidene-γ-aryl-⊿(α,β)-butenolides (27-35) which seemed to us of interest as test materials for the screening. α-Arylamino-γ-aryl-⊿(α,β)-butenolides were prepared by the reaction of sodium or potassium arylidenepyruvate with arylamines in the medium of glacial acetic acid as is reported by Meyer and Vaughan(2) (Scheme I, see also Experimental Section). α-Arylidene-γ-aryl-⊿(β,γ)-butenolides were prepared by the condensation of aromatic aldehydes with β-aroylpropionic acids in the presence of anhydrous sodium acetate. The analogous procedure for this purpose has been reported by several authors(3) (Scheme II). The physical properties, yields, and analytical data of these compounds have been summarized in Table I (1-26) and Table II (27-35).
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
10
2
1976
A Study of Magnetic Properties of Solid Oxygen, Oxygen-Argon and Oxygen-Fluorine
81
111
EN
Akira
Sakakibara
To acquire information on the interaction between oxygen molecules in solid phase, studies have been carried out on the magnetic properties of solid oxygen, oxygen-argon and oxygen-fluorine. Review of the studies on the interaction between oxygen molecules is cited. Magnetic susceptibility was measured by the Faraday method as a function of temperature from 12 K to the melting point of them. Pure oxygen both in α and β phase indicates paramagnetism corresponding to long-range antiferromagnetic order. Oxygen -argon mixtures of 92~66 mol% oxygen content indicate large susceptibility corresponding to δ phase, which can be interpreted in terms of the cluster of oxygen molecules in trimer. Small paramagnetism was found for the oxygenfluorine mixture even as dilute as 10 mol% oxygen
content, which may be due to the strong antiferromagnetic
interaction. This can be interpreted in terms of super-exchange interaction between oxygen molecules via fluorine molecule.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
10
2
1976
The Computer Programs of Layout Methods Based on Decision Making Theory
63
80
EN
We tried to look at the allocation techniques in plant layout from the point of view of decision making theory. And it was made clear that Laplace, Minimax and Hurwicz princilpe can be applied to the allocation techniques. The techniques based on these principles were called Laplace method, Minimax method and Hurwicz method. In this paper algorithms and computer programs of these methods were described in order to solve the layout problems effectively.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
5
1
1970
Diffusion Phenomena of Silver Ion in Molten Sodium Borate by Chronopotentiometry
47
53
EN
Diffusion phenomena of silver ion in the molten sodium diborate of low silver ion content were investigated at the temperature range from 880℃ to 625℃ by means of chronopotentiometry. From the results, it was shown that the silver ion was reduced reversibly to metallic state at the silver electrode used and silver ion was transported only by diffusion in case that transition time in a potential-time relation was within several seconds. Diffusion coefficients measured at various temperatures
satisfied Arrhenius equation. The activation energy of diffusion and diffusion coefficient were respectively 32Kcal/mol and 6.5×10(-7) cm(2)/sec at the liquidous
temperature. By comparing these values with those obtained in some molten salts, the difference of structure between the molten glass and molten salts was discussed. Moreover, the consideration for the size of borate anion existing in the molten glass was also tried from the viewpoint of rate process and from Stokes-Einstein's equation.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
10
2
1976
A New Application of Transient Recorder to Magnetic Measurements (Part I: Core Loss Measurement at Very Low Frequencies)
55
61
EN
A new method have been developed based upon analogue-to-digital conversion techniques and memories. The method involves the scaling of operating frequency from "real" to "optimum" for the power loss measurement. The advantages of using this techniques are as follows: (1) extreme availability at lower frequency region, (2) high accuracy and high stability, (3) simple measuring procedure, (4) digital indication. This method can be measured the power losses over the frequency range 0.1Hz to 1kHz for magnetic circuit and d.c. to 1kHz in such a purely resistive circuit. We estimate the accuracy of this core loss measuring system within 1.0% over all these frequency range. Using this system, specific core losses of the various grades of silicon iron have been measured in the frequency range 0.1Hz to 200Hz.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
10
2
1976
Control of Magnetizing Inrush Current in a Transformer by Means of Thyristors
45
54
EN
When a transformer is energized, the inrush of abnormally high magnetizing current may be noted for a short time until normal flux conditions are established. This may cause the failure of a protective relay, so many preventives are usually accepted for the purpose of normal relay performance. The authors, instead, now have tried to control the inrush current itself, by means of the soft starting method using two reverse parallel thyristors. In this paper, the method to control the inrush current itself, is presented by the soft-starting method using thyristors. The experimental results of this Method verifies the good controlability of the transient magnetic flux of a transformer and then the availability of the control of magnetizing inrush current in the cases of a single phase connection and a three phase one.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
5
1
1970
Analysis of Warren's Fluidic Counter
31
35
EN
Though the Warren's fluidic counter has a very simple construction, the matching problems of the main jet supply pressure with the input pulse may take place and so there may be some working conditions under which this counter cannot work. Up to now, these matching problem have been hardly investigated. In this study the following things were systematically investigated : the static and dynamic characteristics of the memory and the control flip-flops
with different geometric parameters, the behavior of the counter which are constructed by two of them, and finally the fow in the counter. The obtained results are as follows : (1) Under some clear and accurate conditions, the Warren's counter works satisfactory without any au iliary circuit. (2) In the control part, the input pulse flow don't reattach on any side wall, but branches into both output ports. (3) The necessary condition under which the Warren's counter behaves successfully is as follows :
(1-2α)Q(i)>Q(ms), where α is the distribution factor of the control part, is the input pulse flow rate and is the switching control flow rate of the memory part.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
10
2
1976
Synthesis of Ethyl dl-Jasmonate and Ethyl dl-2-Epi-jasmonate
25
30
EN
Sigeru
Torii
Hideo
Tanaka
Ethyl dl-jasmonate (1a) and ethyl dl-2-epi-jasmonate (1b),
novel constitutents in jasmin absolute from Italian Jasminum
grandiflorum L, were prepared from 8-endo-(2'-cis-pentenyl)-3-oxo-2-oxa-bicyclo [3.2.1] octane, jasmine acid δ-lactone(2). Improvement of the preparation of the intermediate (9), a key precursor of (2), was made by different route via lactonization of (7) and/or (8). NMR and IR spectra (la) and (1b) are given.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
10
2
1976
An Arrangement of Flow Velocities and Turbulence Profiles of Co-Axial Cold Jet
15
24
EN
Results of calculations and experiments on the cold co-axial flow presented in this paper are summalized as follows ; (1) A theoretical expression method for co-axial flow field of two dimension is investigated to estimate more
exactly the flow profile and the velocity gradient. (2) Measurements of mixing length were carried out for the confined co-axial jet flow. On the basis of measured data, inquiry is made for the propriety of the assumption proposed in the previous paper (1) that the mixing length may be expressed as a function of the minimum distance to the nearby wall. (3) Experimental inquiry was also done on the corelation between Lagrangian length scale and the mixing length.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
5
1
1970
A Study of the Work Load in a Monotonous Task
27
30
EN
The work load given to workers by a monotonous task was investigated. Their load was obtained by measuring the flicker value and observing its fluctuation pattern. Each flicker fluctuation was classified into one of the three patterns. It was found that the mental load of the subject carrying out the task by himself tends to become lighter according as the speed increases, while the mental load of the subject doing the task with his companion does not show this tendency. On the other hand, the scores of the disposition tests were analyzed with regard to the flicker fluctuation pattern by using the discriminant function.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
5
1
1970
An Investigation on Low Frequency Combustion Oscillation
17
26
EN
This paper deals with a combustion stability of diffusion flame. A simplified linear differential equation of second order, which involves the parameters estimated from the states of steady combustion, has been suggested to discuss
theoretically the nature of oscillatory combusion about a two-dimensional combustion chamber. Its validity has been testified by comparing calculated results with experimental ones. Results obtained have indicated that factors markedly affecting the low-frequency oscillatory combustion are primary volumetric air-fuel ratio, duct length of combustion side, shape of burner and inlet
throttles. But outlet throttle gives little effect on the stability of combustion.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
10
2
1976
The Effects of Time Constant and Absorption on Stress Measured by X-ray Diffraction Method
1
13
EN
The diffracted intensity of X-ray depends upon several physical and geometrical factors such as structure, multiplicity, absorption and Lorentzpolarization and measuring conditions such as time constant and scanning speed of detector on counter method[l]. For analyzing on the X-ray stress measurement, especially, profile shape of X-ray diffraction which is affected by geometrical factors such as absorption and Lorentz-polarization is very important. In order to eliminate these factors affecting the stress measured by using X-ray, the correcting factors were introduced and those theoretical values were calculated. After this theoretical calculation, it is found that as the half value breadth increases the difference between the stress measured by using X-ray and the corrected one becomes larger and larger under same measuring condition. When the ideal diffracted intensity of X-ray is assumed Cauchy distribution the measured stress depends upon measuring condition for same specimen, but it is independent of measuring condition in Gauss, distribution. Consequently, it is found that the stress measured by using X-ray must be corrected under each measuring condition and the method of correction is made clear and proved experimentally in this paper.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
5
1
1970
The Dependency of Stress on the Diffraction Plane in the
Polycrystalline Metals
7
15
EN
The loading and residual stresses measured by using X-ray stress measurment depend on diffraction plane. In order to make clear its cause, the several models on elastic and plastic deformations are developed and the theoretical
values are compared with measured ones. It was found that the dependencies of measured stress on the diffraction plane can be explaned by accepting Reuss's model for elastic deformation and Taylor's model for plastic deformation.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
10
1
1975
On the Vacancy-Zn Atom Binding Energy in Al
49
59
EN
Mutsuo
Ohta
Hisami
Kawazoe
Akira
Sakakibara
Binding energy between a vacancy and a Zn atom in Al was investigated by measurement of as-quenched resistivity in Al-0.021at % Zn and pure-Al, with the estimation of vacancy loss during quenching. The contribution of clusters to resistivity in Al-0.021at % Zn waa also investigated. Their results are summarized as follows: (1) The results of isothermal and isochronal annealing indicate that clusters in Al-0.021at % Zn cnuld not be detected beyond the experimental errors. (2) The model applied to estimate the vacancy loss in pure-Al has enough validity. The quantitative estimation of clusters ana the improvement in experimental conditions are greatly desired, which enable the more detailed, analysis of the data.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
10
1
1975
G.P.zones and Clusters in Al-Zn Alloy and Al-Cu Alloy
39
47
EN
As to Al-Zn alloy, the difference between the formation of
G.P.zones and that of clusters was investigated by measurements of electrical resistivity. The results obtained were summarised as follows: (1) G.P.zones formed during the quench and quenched-in vacancies increase greatly as-quenched resistivity P(o) as quenching temperature Tq is raised, and clusters increase slightly P(o) as Tq is lowered. (2) For one Tq and one Ta, the time required to reach P(e)' for Al-1.3at % Zn alloy is longer than that for Al-3.0at % Zn alloy. This is due to the difference of number of zinc atom in the clusters. (3) For one Ta and one concentration of zinc, the time required to reach p'(e) at Tq = 170℃ is longer than that at Tq = 300℃. This is due to the difference in concentration of quenchedin vacancies. As to Al-Cu alloy, the solvus temperature for G.P.zones was determined from the existence of P(m) in ageing curves by measurements of electrical resistivity. Consequently the solvus temperature is between 20℃ and 60℃.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
5
1
1970
Further Considerations Concerning a Mechanism of Fatigue Crack Propagation
1
6
EN
X-ray microbeam diffraction technique is a useful one to investigate the features of the crystal deformation in a localized area. That is, this method have been adopted to examine the density and array of dislocation, microscopic
lattice strain and macroscopic residual stress. And so, the informations obtained from the tip of the crack during the fatigue process have been correlated with the behaviours of the initiation and propagation of the crack.
The authors, in the present paper, investigated a relation between the distributions of the microscopic lattice strains which are calculated and measured by the technique, and suggested the sort of dislocation at the tip of the crack that relate to the fatigue crack propagation. The crack initiated at the notch root of the specimen which was composed of the coarse grain and propagated along the grain-boundary in the early stage under fatigue process of the alternating stress 4.1 kg/mm(2). Thereafter, it changed the propagating direction toward the inside of the grain. The distributions of the micro lattice strain in each reflecting plane which were measuerd at the plastically deformed zone in the vicinity of the grainboundary and at the crack tip agreed well with modes of the strain distribution due to a screw and a edge dislocations by the calculation, respectively. From these results, the authors concluded that the fatigue crack propagation would relate closely to the changing in the sort of the dislocation from the screw to the edge.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
10
1
1975
Computer Program of Forward Selection and Backward Elimination Procedure in Linear Discriminant Analysis and Test for
Differences Between Mean Values of Two Populations
17
37
EN
In multivariate analysis, the linear discriminant analysis and the test for differences between mean values of two populations are of wide application. It is not essential to increase the variables only in order to increase the degree of accuracy of discrimination or test without evaluating the effect of variables. Therefore the computer program of selection procedures of variables in these two methods is
mentioned in this paper.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
4
1
1969
On the Speed Control of a Three Phase Squirrel Cage Induction Motor Controlled by a Variable Frequency Three Phase Thyristor Inverter
65
73
EN
As one of the wide application of thyristor circuits, the inverter has a promising future and has been investigated vigorously. On the speed control of a squirrel cage induction motor by using a variable frequency thyristor
inverter, although few papers have been presented, there seems to be many problems to be solved imminently. In this paper, the stability of performance of a thyristor inverter on this theme has been confirmed and some particular points with relation to practical use also have been discussed.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
10
1
1975
Undeformed Chip Shape in Angular Grinding
1
16
EN
This paper describes the basic boundary conditions in angular grinding, which is widely applied as a high efficiency machining and where a complicated-shaped workpiece is ground at the same time. The angular grinding is first classified into three basic types, an external, a surface and an internal angular grinding, depending on the axis angle between the wheel and the work axes. The undeformed chip shape, which is characterized by the interference angle, the maximum chip thicknes and the chip length, is then analyzed in each type of angular grinding.
The effects of grinding conditions such as the axis angle, the speed ratio, the radius ratio and the successive cutting edge spacing upon the geometry of undeformed chip are discussed to make clear the relations between the basic boundary conditions and the working conditions in angular grinding.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
4
1
1969
Effect of Nozzle Length on Breakup Length of Liquid Jet
57
64
EN
Although the stability of Newtonian liquid jet has been investigated experimentally and theoretically, many problems has remained unsolved. Especially, the stability of liquid jets in immiscible liquid systems has been little studied. Furthermore, one has to point out that the stability of jets may be influenced by the turbulence in the nozzle and the velocity profile. This work presents the experimental result about the effect of the nozzle length on the breakup length of liquid jets in the air and in the immiscible liquid, as the beginning of a systematic investigation of the influence by these factors on the
breakup of jet. The dependence of the initial amplitude of surface disturbances on the nozzle geometry is presented for evaluating the effect of the nozzle length on the breakup length of laminar liquid jet in the air and in the
immiscible liquid.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
4
1
1969
Gas-phase Mass Transfer Resistance in Rotational-current Tray
51
56
EN
In this report, the average holding time of gas in foaming layer and the number of transfer units based on gas-phase of the Rotational-current tray were considered experimentally. The average holding time was determined by water-air system. On the other hand, the number of transfer units was determined by water-ammonia-air system that gas-phase resistance controlled. The average holding time increases with gas and liquid velocities, and does not change with the tray dimensions clearly. From the experimental results of the number of transfer units, it was found that the tray can be operated at high efficiency up to larger gas and liquid flow rates than that of sieve
trays.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
9
2
1974
Dynamic Design of a Tunnel Diode Transistor Combined Circuit
107
118
EN
The dynamic design of a tunnel-diode-transistor combined circuit and the applied pulse circuits are discussed. The combined circuit, in which a tunnel diode is connected in parallel with the collector junction of a transistor, is used. The dynamic design procedure is considerably simplified by describing the transient behavior of a tunnel diode with a set of approximate expressions and by the help of a selfanalog simulator. This circuit is capable of carrying out both memory and majority logic operations, and
serves as a basic unit for several different pulse circuits, such as a mcnostable circuit, a frequency divider, a ring counter, etc.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
9
2
1974
Computer Program of Forward Selection and Backward Elimination Procedure in Multiple Regression Analysis
89
105
EN
Multiple regression analysis are often used to explain the relation between the dependent variable and the independent variables. In case of that it arises necessity that the important independent variables which are closely correlated with the dependent variable are selected from among all given ones. There are some selection procedures. But these procedures can't be used usefully without using
computer. Therefore two selection procedures that is Forward selection procedure and Backward elimination procedure in multiple regression analysis are programmed by Fortran Ⅳ.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
9
2
1974
Mass Fragmentations. II. Some Aspects of Mass Spectra from a Series of Compounds Related to Methyl dl-Jasmonate Syntheses
53
61
EN
Sigeru
Torii
Hideo
Tanaka
Tadakatsu
Mandai
This paper deals with graphical mass spectral data of the
twentyfive compounds related to the preparation of methyl dl-jasmonate and its related materials. The fragmentations from the substituted cyclopentanones and norbornane derivatives can serve basic data for both characterization and elucidation of the structures of complex compounds referring to the preparation of principal components of jasmine flower.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
9
2
1974
Mass Spectral Fragmentations. I. Mass Spectral Date on the Synthetic Intermediates Related to the Preparation of Linaloyl Oxide
47
51
EN
This paper describes mass spectral data from synthetic
intermediates of linaloyl oxide. The fragmentation of sulfur functional groups including compounds l-8 would provide fruitful evidences for structural assignment of acyclic and alicyclic monoterpenoid precursors. Since, 1,3-dithianyl group in l,2, and 3 can provide a base peak and the elimination of the sulfinyl group from 7 and 8 is considered to occur at the initial stage of the fragmentation.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
9
2
1974
Reduction of Engine Exhaust Noise by Throttling in an Exhaust Manifold
35
45
EN
This paper covers the work done in an attempt to reduce exhaust noise level without the decay of brake mean effective pressure of a two-cylinder two-stroke cycle engine, by means of an exhaust manifold having a throttle plate in its junction. The data are shown for various dimensions and configurations of the manifold and the discussion is given on the effect of exhaust throttling on exhaust noise level and engine performance. The principal results obtained by this study are as follows: (1) The lower limit of the throttle area was about onethird of a cross-sectional area of the manifold from the view point of brake mean effective pressure. (2) Within this limit brake mean effective pressure was scarcely influenced by throttling under the condition where a number of pressure oscillation related to the pulsation effect during an interval between discharges was less than 1.7. (3) A reduction in exhaust noise level attained was 8 dB(A) at higher engine speeds. (4) The junction angle of the manifold gave little significance to exhaust noise level and brake mean effective pressure.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
9
1
1974
Field Analysis of SF(6) Gas Insulated Cables and Its Application to Spacer Design
23
33
EN
This paper describes the spacer design for SF(6) gas insulated cables. The maximum electric stress within the cable is calculated by a numerical method, and it is recognized that the breakdown voltage depends linearly on the calculated values. Moreover, the effects of varying the shape of the spacer are made clear in this study for designing an optimum spacer.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
9
1
1974
Grouth of G.P. zones in Al-Zn alloy
11
21
EN
Metastable values of electrical resistivity, P(E)' obtained during isothermal ageing differs in each experimental run even when the conditions of quenching and ageing were carefully kept constant. This phenomenon is considered to result from the competitive growth of G.P.zones. The range of the values of P(E) under the same conditions of heat treatments were examined, and the results obtained are as follows: (1) Metastable values of resistivity, P(E), during ageing at 70℃ after quenching from 300℃ were in rather narrow range. On the other hand, the width of the range obtained during ageing at 50℃ was wide. (2) When the specimens were aged at first at 70℃ until the maximum values of resistivity, P(M), being reached and then aged at 50℃ for long time, the metastable values of resistivity, PE*, were obtained. And the width of discrepancy of values of P(E)* was nearly equal to that of P(E) which was obtained in the case of isothermal ageing at 70℃ after quenching from 300℃. (3) It may be concluded that the width of discrepancy of values of P(E)* becomes smaller since the width of discrepancy of the number of G.P.zones for all experiments which can grow through competitive growth is made small by 70℃ ageing than that immediately after quenching from 300℃.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
9
1
1974
A Study Dust Abatement by Combustion
1
9
EN
This paper deals with the abatement of the dust, which is produced from combustion of wood which is used in the process in the manufacture of "Bizen Yaki", by means of combustion. The experimental furnace disposal for after combustion, is added to "Nobori Gama". The measurements are
done at both states without and with the furnace disposal.
The results of the experiments show that process exhaust gases containing combustible dust can be destroyed effectively by the furnace disposal and the obtained dust abatement efficiency is about 80%.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
8
2
1973
On the Phase Adjusting of a Magic T-Coupled Oscillators System
66
74
EN
Kiyoshi
Fukui
Shigeji
Nogi
A magic T-coupled two oscillators system having arbitrary amount of phase adjusting errors is studied both theoretically and experimentally. Denoting two independent phase parameters of the system measured from their optimum values as Δφ and Δψ, it is derived analytically that the optimum operation is possible in principle in a definite region of Δφ - Δψ plane, so we have a considerable amount of margin for phase adjusting error. Experimental result also confirms the existence of some phase error margin, though the measured magnitude of margin is smaller to some
extent than the theoretical prediction.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
8
2
1973
Dynamic Behaviour of Attaching Jet
52
65
EN
The dynamic behaviour of attaching jet with single side wall to step control flow and the switching proces of the bistable amplifiers were investigated experimentally and theoretically. In the experiments, a large scale model was used with water. The flow patterns were visualized by the tracer of polystrene granules and were recorded by a cinecamera. In the analysis, the quasi-steady proces was assumed. The results obtained can be summarized as follows:
1) The proposed analytical dynamic model of attaching jet explains well the dynamic behaviour of attaching jet with single side wall. 2) The process" of the opposite wall switching may be divided into three phases. 3) The analytical model of the opposite wall switching, including the formulation of the switching criterion, was proposed.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
8
2
1973
The Friction Factors of Oscillating Pipe Flows
44
51
EN
In this study, the friction factors of oscillating pipe flows are experimentally investigated. As the oscillating pipe flow, the pendulation of water column in the special vertical U-tube, which has about the 2 m long horizontal straight foot pipe, is utilized. The results of experiments show that the momentary friction factors in the accelerating state are smaller and in the decelerating state are larger than that in steady state for each Reynolds
numbers.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
8
1
1973
The Effect of Temperature Gradient on Ultrasonic Attenuation
41
43
EN
The effect of temperature gradient on ultrasonic attenuation is estimated based upon the simple phenomenological theory, and it being found that the
attenuation coefficient for a CdS crystal is 0.76 dB/cm at temperature gradient 100 K/cm.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
8
1
1973
Effects of Wall Length and Vent on Attaching Jet and Its Switching
25
40
EN
The effects of some geometries peculiar to the wallattachment fluidic devices on the attaching jet flow and the switching mechanism were experimentally made clear. And the propriety of the analytical mOdel, which has been used for the theoretical study of these devices, was investigated. The results can be summarized as follows: 1) The existing analytical model of the attaching jet flow is not applicable to the case of relatively short wall length of vent distance. 2) The attaching jet flow never detaches from a sufficiently long side wall with vent. 3) The switching mechanism of the vent type device is always the opposite wall switching. 4) From the viewpoint of the output characteristics of the device, the vent distance has a lower limit in relation to the vent width.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
8
1
1973
Allocation Technique Using Relative Distance and Relative Volume Estimated by Statistical Procedure
15
24
EN
This paper deals with the allocation technique of the layout whose solution it takes as a little computation time as possible to obtain and which becomes as near to the optimal method as possible. In this method, the relative transport distance of each location and the relative transport volume of each department are calculated from the distance matrix and the volume matriX by the statistical procedures. And allocating departments to locations is determined by one to one correspondence between the arranged relative transport distances and the arranged relative transport volumes. This method was called the allocation technique by the statistical procedure ( ATSP in short ).
This method doesn't use the heuristic algorithm.
Therefore the calculation time can be reduced much in
comparison with any other methods. As the algorithm
of ATSP method is very simple, the sub-optimal layout
can be determined easily by using the desk-calculator
in cases of any layout problems.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
8
1
1973
Experimental Studies of Various Factors Affecting Minor Loop Hysteresis Loss
1
14
EN
When the distorted flux is induced in a magnetic circuit, the minor loops arise sometimes inside the major hysteresis loop. The area, accordingly the hysteresis loss of the minor loop,is affected by its amplitude and position, by the maximum flux density, by the quality of material, etc.. In this paper, we describe the experimental studies of the factors on the minor loop hysteresis loss. A method of getting the displacement factor of a minor loop which is placed at arbitrary position and has any amplitude is developed from our experimental results. Using this method, the core losses caused by the distorted flux can be calcuLated within the error less than three percent, even if the amplitude of the minor loop becomes near to the amplitude of the major loop.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
7
2
1972
Analysis on Magnetic Characteristics of Three-Phase Core-Type Transformers [Part II: Non-Linear Solutions and Experimental Results for R3-Type Core]
89
100
EN
This paper deals with the magnetic characteristics (the flux distributions, core losses, etc.) of threephase core-type transformers with double-layer. In the preceding report, only linear solutions have been given. In this paper, also non-linear solutions are discussed. Therefore, the flux waves of each magnetic path are distorted and contain various harmonics. When core losses are calculated, the hysteresis losses of minor loops are taken account. The results of analysis are compared with those of experiments. It is concluded that the principal cause for increasing core losses of this type core is the eddy current loss produced by harmonic fluxes. The flux distributions and the core losses depend on the shapes of the magnetization curve and the core-loss curve, that is, on the quality of the materials.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
7
2
1972
A New Representation of Distorted Wave Forms
85
88
EN
A new method for representing distorted wave forms is investigated. The method suggested by us is a modified vector symbolic method. It has been hitherto thought that the vector symbolic method cannot be applied to the distorted waves, because the rotating speeds of each harmonic vector are not identical. Representing the argument of the n-th harmonic vector by l/n times as large as the phase angle of the harmonic component, the relative positions of respective harmonic vectors are invariable wherever the standard vector is put, and the wave shape can be deduced from the vector diagram. We found various correspondences between the wave forms and the vector diagrams. Therefore, the wave shape can be estimated from the vector diagram, and the mutual relationships between two wave forms can also be known. In electric or magnetic circuits, the causes of distorted wave forms are in general obvious. Therefore, there are very often the fixed relationships between the amplitudes and phase angles of the harmonics. Further, in polyphase a.c. circuits, there are often the fixed relationships between corresponding harmonics in the wave forms of the respective phases. When the wave forms of those circuits are discussed, the new method investigated in this paper may offer a useful key.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
7
2
1972
A Study of Anisotropic Workhardening
49
60
EN
This paper deals with the stress-strain curves of single crystal and polycrystal considering the workhardening and the anisotropy which is due to the difference of workhardening on each slip system. The results obtained are summarized as follows: 1) The equations of workhardening on each slip system are derived according to the dislocation theory. 2) And it is found that the stress-strain curves of Cu single crystal and polycrystal calculated by using the workhardening equation with proper coefficients agree well with the experimental values.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
7
1
1972
A Consideration on Sub-Optimal Weighting in Parameter Estimation
43
48
EN
This paper deals with a parameter estimation method which
yields the more suitable estimate of the parameter using noisy data or measured values. The estimation method is one that uses a kind of a weighted mean, and weighting at taking a weighted mean is interested in particularly. That is to say, as the grade of 'more suitable' depends upon the weighting, we can obtain the more suitable estimate by choosing the weighting coefficients suitablly. When the function which yields the estimate using finite measured values, i.e., the estimator is a particular form, sub-optimal weighting in the practical sense is discussed. Here, the concept of 'optimal' implies that the variance of the final estimate is minimum. And the particular form is one that both the denominator and the numerator of the
estimator are first order formulas or second order formulas of finite measured values. And two theorems in relation to this problem are proposed and proved. Moreover, for an exsample of application of these theorems,
a parameter estimation method is dealt with, which estimates the parameters of the pulse transfer function of a control system using the sampled measured values of the impulse response of that system.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
7
1
1972
Magnetoacoustic Amplification by Conduction Electrons
31
42
EN
A theory, based on Chambers' method to the classical Boltzmann equation, is developed for an acoustic amplification in both degenerate and nondegenerate piezoelectric semiconductors subjected to the Hall geometrically configured electric and magnetic fields. It is found that an amplification constant for qR>1 holds not only for a magnetic field ω(c)τ>1 but for ω(c)τ<1 under ql>1 while the amplification constant for qR<1 does for ql≦1 under ω(c)τ>1; q is the wave number vector of sound, R the cyclotron radius, ω(c) the cyclotron frequency, 1 the mean free path and τ the relaxation time. A generalized attenuation (amplification) constant is presented through an energy conservation law, being applicable to the sounds propagating at any angle with respect to the particle drift so the off-axis as well as on-axis amplifications are surely involved. An application of the present theory to n-InSb reveals a threshold dependence for the acoustic amplification, which is semi-quantitative agreement with the experimental result of Arizumi et al.. The amplification constant by that nondegenerate particles is found to be almost equal to that by the degenerate ones, provided that the former carrier density should be replaced by its three times as much.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
7
1
1972
Response of Electromagnetic Deflection for CRT Display
25
29
EN
In the CRT display system of high-speed electromagnetic
deflection, the tendency to amplifier saturation should not be neglected. We first show the limitation to the linear characteristics of input-output response and the response time under the saturation condition in this system. We try to improve the frequency-characteristics of the amplifier by making the load resistance constant and the feedback-paths partially positive, and reduce the L/R value of the load circuit by adopting the mutually-coupled yokecoils and the low-current amplifier. As the result, it is suggested that a low-power dissipation and highspeed response electromagnetic deflection system can be constructed.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
7
1
1972
On a Study of the Empirical Formula to Explain the Work Amount
1
9
EN
This paper deals with the empirical formula to explain the
work amount curve of a worker during a work. The empirical
formula yt = at(b) + c was used to explain this phenomenon until now. This formula has been used mainly to approximate to the monotonous trend of the work amount curve. But it was made clear that if the work amount curve showed the polynomial trend, it could not be done so. Then the authors attempt to establish the empirical formula yt = a/{exp(Σb(i)t(i))-l} + c, which was the general form of the logistic curve in order to explain not only the monotonous trend but also the polynomial trend of the work amount curve. And it was made clear from the results of the approximation that this formula was the one of the most usuful formula in order to explain the work amount curve.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
6
1
1971
Analysis on Magnetic Characteristics of Three-Phase Core-Type Transformers (Part I: Fundamental Equations and Linear Solutions)
67
82
EN
In this paper, we report the procedure to analyse magnetic circuits and give the linear solutions on magnetic characteristics of the three-phase core-type transformer which is composed of the complicated magnetic paths. First, we explain the construction of cores investigated and normalize the sizes of a core. To analyse these magnetic circuits, we introduced the electrical eqcuivalent circuits and obtained the general fundamental equations for each core. Then, we drew the linear-numerical solutions using an electronic computer, and cleared the relationships between the sizes of a core and the amplitudes and phase angles of fluxes in magnetic paths. Related with the above facts, we investigate the influence of these sizes on the core loss using cores of various quality.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
6
1
1971
Analysis and Design of Parallel Inverter Circuit with Parallel Inductive Load
61
65
EN
In this paper, the parallel inverter circuit with the load consisted of resistive load and constant reactive load in parallel, is analyzed taking into acourlt the d-c source reactance. The circuit has a good voltage regulation for the variation of resistive load current, except the vicinity of no load. The design method in using the results of analysis is also discussed.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
6
1
1971
Thermal Study on Adducts of Urea with n-Alkanes and n-l-Alkanols
57
60
EN
Crystalline adducts of urea with n-alkanes (C(8)~C(20)) and n-l-alkanols (C(12)~C(18)) were prepared. From thermal analysis and X-ray diffraction study on the adducts, we found that the composition of adducts and the heat of decomposition can be obtained easily from the thermogram of adducts.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
6
1
1971
Polymorphism of Amylose V Complexes
53
56
EN
Lamellar crystals of amylose V complexes with the 6(1), 7(1) and 8(1) helical configurations can be prepared from aqueous solutions of amylose by using various complexing agents. It is noted that the crystal shape can be explained
by the symmetry of the unit cell in the basal plane and the chain packing in the unit cell is cOncerned with the symmetry of helical chains. The existence of 6(1), 7(1) and 8(1) heliccs which occurs stepwisc with the number of glucopyranose an intger is discussed.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
6
1
1971
Solubility of Sulphur in a Cadmium Borate Glass and Some
Properties of the Sulphur Containing Glasses
47
52
EN
The glass forming limit by substitution of CdS for CdO in a CdO-B(2)0(3) glass was determined by chemical analysis. When x CdS-(60-x)CdO-40B(2)0(3) nominal mixtures in weight ratio were heated at 1100°C in flowing nitrogen gas for 1/2 hour, about 40~50% of mixed CdS and 10-15% of the mixed CdS were evaporated. The limit of nominal composition for glass forming was 10CdS-50CdO-40B(2)0(3) and the corresponding virtual composition after the above heat treatment was found to be 4.9CdS-46.4CdO-48.7B(2)O(3). Further addition of CdS made the melt devitrefied with CdS precipitation. D.C. conductivity measurements revealed that the current density was not linear with respect to the applied voltage, but the resistivity ranged around 10(12)Ω･cm for 4.1CdS-48.8CdO-47.1B(2)O(3) (virtual composition) glass and around 10(11.5)Ω·cm for 4.9CdS-46.4CdO-48.7B(2)O(3) glass. These sulphur containing glasses did not show photoconduction, although CdS-precipitated materials showed slight photoconductivity when disposed in ultra violet radiation. Apparent dielectric constant and tan 8 were also measured as a function of frequency, revealing a moderate dispersion in the CdS-precipitated glasses.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
6
1
1971
Deformation and Prefered Orientation of Precipitates in Cold Worked Al-Zn Alloys
27
31
EN
Fiber textures of drawn wires of Al-Zn alloys containing precipitates were studied mainly by X-ray methods. In supersaturated solid solution the wire texture was a double fiber texture with [100]and [111]. It was considered that a phase precipitates were rotated with matrix, while they were deformed. And then the matrix containing stable precipitates (Zn) had [100] and [111] textures. The intense spots, corresponding to [111] fiber texture of matrix, in the Debye rings of (002)p and (101)p planes of precipitates were clearly observed. But, on the other hand, spots, corresponding to [100] fiber texture of matrix, shown the prefered orientation of precipitates in (002)p Debye ring were very weak and brodening.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
4
1
1969
On a Relation between the Flicker Value and the Vibration
35
38
EN
Insuring fast and precise human operation is one of the engineering requirements in the developing civilization.
Some man-machine system, when any operator is exposed himself to some kind of vibration, he may not perform his operation in good conditions. Then one of the interferring factors, there is a fatigue caused by vibration. In this study, subjects sit on the chair which was set on the vibration table, and were shaken vertically for some given times, then were measured whether the fatigue occured or not by flicker friction tester. Flicker patterns were analyzed according to each vibration-condition, then the authors knew that the fatigue was occured by vibration.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
6
1
1971
Effects of Pointed Splitter Position on Attached Jet Switching
21
25
EN
In this report, the effects of splitter position on the attached jet were experimentally investigated for the purpose of discussing the applicability of a usual mathematical model without splitter. As results, the followings were confirmed, (l) For the splitter distance shorter than the critical distance, the pressure in the bubble lowers and the jet radius of curvature shortens.
(2) At the ratio L(s)/D=4~5, the switching control flow rate becomes maximum. And bordering this value, the effects of splitter position on the switching are quite conversely. For the splitter distance longer than the above value, the switching control flow rate decreases, as increasing the distance. (3) For the splitter distance of 1.5~2 times critical distance, the switching is almost never affected by the splitter.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
4
1
1969
On a Relation between the Flicker value and the Working Condition
31
34
EN
The appropriate disposition of the worker improves the ability of the worker and the efficiency of the labor and further decreases the rate of inferior goods and the rate of accidents. In previous paper, the variation of the flicker value, the trend of the miss frequency and the relation between them under the condition which has one surveillance point and one back-ground condition are analyzed. In this paper, the surveillance point is increased to two points and the back ground condition also two in order to examine which condition influences strongly to the flicker value in the working time. It was found that the variation of the flicker value is strongly connected with the qualification, the number of the surveillance and its miss-frequency.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
6
1
1971
On the Trial Production of the Equipment Measuring Many
Subjects' Critical Flicker Fusion Frequency at the Same Time
13
19
EN
The equipment measuring the critical flicker fusion frequency (CFF) is made in order to measure many subjects' CFF at the same time. This equipment is defined the multi-flicker. The equipment measuring CFF, used until now is defined the mono-flicker. It is analysed what factors influence CFF strongly. Then it is made clear that CFF value measured by the multi-f1icker can be used to show the brain weariness as well as that of the mono-flicker, and the vigual angle and the intensity of illumination in the room influence CFF value strongly.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
4
1
1969
On Conformal Mapping onto Circular-Radial Slit Covering
Surfaces of Annular and Circular Types
19
30
EN
In paper 7) we concerned ourselves with the conformal mapping onto circular-radial slit covering surfaces over the whole plane and its extremal property. In the present paper we shall concern ourselves with the conformal mapping onto circular-radial slit covering surfaces of annular and circular types and their extremal properties (Theorems 1.1 and 2.1). Especially the extremal property with respect to the radial slits is new. The results are stated only for the case of the planar domain of finite
connectivity. The method suggests the possibility of an extension to the case of a domain of infinite connectivity or an open Riemann surface of finite genus. We shall concern ourselves with this problem in the subsequent paper.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
6
1
1971
On the Friction Factor for the Turbulent Flow of Dilute Aqueous Polymer Solutions
7
12
EN
A series of turbulent pipe flow experiments with dilute aqueous C.M.C. solutions are described. The purpose of these experiments are to compare the anomalous viscous drag results from these experiments with the results using water (Newtonian viscous fluid). The additive concentrations of the present experiments are from 0.01% to 0.5% by weight of C.M.C., giving power-law indexes 1 to 0.75, respectively. All of the concentrations are found to give a reduction in turbulent friction factor, compared with Newtonian at the same Reynolds number. A maximum friction factor reduction of 64 % is obtained at a Reynolds number 2x10(3) for solutions having polymer concentration of 0.3% by weight.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
4
1
1969
On the Friction Coefficient for Turbulent Flow Through
Sectionally Roughened Square Ducts (Continued)
13
17
EN
In this study, friction coefficients for sectionally roughened square ducts were measured for transional and turbulent flow. The velocity fields in the cross section were mesured for turbulent flow, and the predicting equation in the previous report was corected.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
4
1
1969
The Friction Factors of Unsteady Pipe Flows
9
12
EN
In this study, the friction factors of unsteady pipe flows have been experimentally investigated. The normal temperature water was used as working fluid and pulsating flow superposed on the steady turblent flow, having the variation of velocity approximately represented by sine curve, was used. In the result, the time mean friction factors of the unsteady flow agree with that of steady flow, and the momentary friction factors in the accelerating state are smaller and in the decelerating state larger than that in steady flow for each Reynolds numbers.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
4
1
1969
On the Development of X-Ray Stress Measurement Technique
Using X-Ray Diffraction by Crystal Oscillation Method. I,
1
8
EN
In the present paper, to provide information on the stress measurement in coarse grained materials by X-ray micro-beam diffraction technique using a crystal oscillation method, the authors first examined experimentaly and theoretically the relation between the sizes of X-ray beam and crystal to obtain the particular diffraction ring in the case of use of crystal oscillation method. The specimen attachment of X-ray camera used in this experiment can be oscillated automatically around a horizontal and vertical axes with high accuracy centering around an illuminated position on the specimen surface.
Accordingly it is possible to increase the number of the diffraction spots without changing the area and position of the specimen illuminated. Experiments were carried out for three kinds of annealed low careon steel with grain sizes of about 15, 30 and 50μ in diameter, and with X-ray beam collimated by pinhole slits of 0.12, 0.30 and 1.00 mm in diameter, using CrKα characteristic X-rays. On the other hand, a theoretical analysis was carried out according to the X-ray diffraction theory which have been proposed by P. B. Hirsch et al. As the conclusion, it is found that the crystal oscillation method is extremely
useful for X-ray stress measurement of coarse grained materials. Moreover, the conditions of the crystal oscillating operation were clarified theoretically for any pair of the sizes of X-ray beam and crystal.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
6
1
1971
Yield Strength and Stacking Fault Energy on Fatigue Crack Propagation
1
6
EN
It is very important to clarify the question whether fatigue crack propagation will be affected by mechanical propaties or other propaties of materials. In the present paper the authors studied in relation of yield strength and stacking fault energy to rate of fatigue crack propagation. αbrass were chosen for the investigation because they provided sufficient range in both quantities of interest that either could be varied independently of the other. Fatigue tests were carried out under full bending moment of flat specimens with V-shape notch. Chosen stress levels were 0.6 σy and 0.8 σy in which σy is yield strength, rate of fatigue crack propagation was evaluated from the second stage of the curve of fatigue crack propagation. The dependence of the rate on stacking fault energy γ was found to be dl/ dN=G・γ(n). But dl/dN did not systematically to change in yield strength. Thus, γ is concluded to be the controlling variable.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
3
1
1968
Crystallization of Polymers from Solution under Shearing Stress I Polyethylene
77
83
EN
We tried to clarify the crystallization mechanism of long chain polymers in solution under shearing stress using polyethylene. From the bright and dark field electron microscope observations and the electron diffraction study, we demonstrated that the resulting fibrous crystals consist of the central threads with an extended chain character and the lamellae with a folded chain character nucleated on the threads. The measurements of thermal and mechanical properties gave the additional confirmation for this suggestion. From these results we discussed the crystallization mechanism on the fibrous crystals.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
3
1
1968
A Method of Direct Analog Simulation Using Transistor Switches and its Applications
157
162
EN
In the analog circuits for the systms governed by the dilfercntial equations with the coefficients which are a function of one or mOre of the dependent variables, the magnitudes of their circuit elements must be variable in
accordance with the nature of the function. Such circuit elements can be realized by means of inserting or removing the additional elements with high speed switches in the analog circuits. Particularly, in the case of varying stepwise this method is effective. But as an analog circuit is regarded as a short-time or repetitive type analyzer, the above switches must be instantaneous operation. In this paper, first, it is made sure by the experiments that some
of the transistor switches arc met this condition, and moreover arc very low closed resistance, very high open resistance and neglegible small voltage offsets. Next, the basic technique for the direct analog simulation usiug transistor switches is described about the simple example, i.e. the oscillatory system with varying cross-scctional surge tank. Finally, as its applications, the transient
problems of these oscillatory systems arc solved by means of these analog circuits.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
3
1
1968
Analysis of Waveform of the R-C Load-Current Controlled by the back to back SCR Pair
151
155
EN
The waveform of the load current has been analyzed theoretically on the single-phase series R-C circuit controlled by the back to back SCR pair. And then, the fluctuation of the barmonics calculated by the use of the electronic digital computer, has been discussed as for the firing angles of SCRs and the phase angle of load.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
3
1
1968
A Modified Type of the Resonant Turn-off SCR D-C Chopper
143
150
EN
A modified type of the resonant turn-off d-c chopprr using an auxiliary SCR, compared with its conventional one, has no limitation about its starting and also operates more steadily. Presented in this paper, making a comparison between the modified type and the conventional one, are the circuit analysis and its efficiency measurement from the point of view of overall efficiency, that is, the ratio of the output to the input. Furthermore, some effects of the source impedance, counter emf load, etc. are discussed. As a result, it has been analytically clarified that this modified type is different from the conventional circuit only by one terminal connection of turn-off capacitor, but has the features of uncompounded circuit configuration, no limitation about its starting and more steady operation.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
3
1
1968
Measured Dissipated-Energy in Switching-off by Electric Contacts
137
142
EN
The measurement of the dissipated energy in switching-off has been attempted to make clear the function of spark on electric contacts, which may unfortunately cause the combustible gas, such as propane gas etc, to catch fire and result in fire accidents. By utilizing the "Memoriscope" has been the meaurement carried out and the feature of this method is to provide the information on not only the amount of dissipated energy involved in one action but also on the trace of its instantaneous power which can affect catching fire delicately. Presented in this paper are the discussion of this measuring method and the measured results which are obtained experimentally in order to investigate the dependence of the energy dissipation on variety of contacts, contacts' deterioration and circuit arrangements.
No potential conflict of interest relevant to this article was reported.