Fundamental Studies on Impact Crushing

When calculated by means of Rosin, Rammler and Sperling's Equation R=e⁻⁽ˣ/¯ˣ⁾, the residue of the crushed product R is equal to 1, in the case x/¯x=0, and becomes 0 in the case x/x=∞. Whereas, the actual particle size of the crushed product must be always smaller than the initial particle size x₀ of the raw material, or R must be equal to 0 in the case x/¯x=x₀/¯x<∞. Therefore, the above equation does not show good agreement with the measured values of extremely coarse grains. The authors have presented the following equation as an expression for the size distribution of the crushed product and to represent the relations among the net work input to crushing, Aᵣ, the surface increase ΔS, and the size distribution of the crushed product : R=e⁻⁽ˣ´/¯ˣ´⁾ⁿ where 1/x´=a/x-1/x₀ and They presents also as an expression of the relation between the net work input to crushing, Aᵣ, and the number of blows, z. They have confirmed that these equations give good agreements with the corresponding experimental results

Observation of the Behavior of Deuteriums Implanted in Aluminium by Use of the Nuclear Reaction D(³He, p)⁴He

By applying the depth-profiling technique using the nuclear reaction D(³He, p)⁴He, the thermal behavior of deuteriums implanted in aluminium at a depth of 0-2 μm was examined. The behavior of deuteriums depended greatly on the polishing procedures for the sample surface. When the surface was polished on a series of five abrasive papers or finished by diamond paste, the dispersion behavior of deuteriums in aluminium was quite different from that preducted on the basis of ordinary diffusion in homogeneous media. As suggested by Bugeat and Ligeon, it may be explained by the existence of a weak trapping effect against implanted deuteriums. The half-life of the trapped state at 0°C was estimated at about 1.4×10⁴ sec. Once they are released from the trapping sites, they rapidly disperse over the bulk of aluminium with an ordinary diffusivity measured by permeation methods. On the other hand, for the samples whose surface was finished with coarse Al₂O₃, the deuterium implanted at a depth of 0-2 μm had a much smaller dispersibility than those observed for samples which were polished on a series of five abrasive papers or finished by diamond paste. At room temperature the depth profile was almost unchanged, even after a few weeks. A large depth-dependence of the dispersion behavior was observed

スポーツ選手の時間評価(I)

The purpose of this study is to make the exactness of the time estimation of sportsmen experimentally clear. Subjects are 35 male students in Sendai College, including sprinters (100m, 400m), middle-long distance racers, jumpers, throwers, volleyball and tennis players. They were asked to estimate exact times on nine time conditions of 10", 11", 12", 50", 55", 60", 90", 120", and 150", by using a digital stop watch. The main findings are as follows: In general, as subjects repeat trials, the time estimation of subjects tends to approach to exact times. As tennis players repeat trial times, their time estimation is over than that of other players. It does not always follow that the time estimation of track athletes is more exact than that of other players

スポーツ選手の時間評価(II)

The purpose of this study is to clarify the effect of various physical conditions on time estimation and to estimate the time required 150m. and 250m. distance runs. Subjects were 16 male students in Sendai College, including long distance runners, throwers, sprinters, jumpers and the group as a control was consisted of 15 male students including the players of Judo, Kendo, Vollyball, Soccer, Gymnastics and Basketball. Experiment 1 Subjects were asked to estimate the exact time of 30" in rest and after 5 minutes\u27 exercise. Experiment 2 Subjects were asked to estimate the time required 150m. and 250m. distance run. The main findings were as follows: 1-1 Both groups had a tendency of over estimation in rest. 1-2 The time estimation after exercise, sprinters had a tendency of under estimation. Long distance runners, throwers, jumpers and control group had a tendency of over estimation. 1-3 There was significant difference between time estimation in rest and that after exercise. 2-1 In the time estimation of 150 m. distance run, both experimental group and control group had a tendency of under estimation. There was little difference in the time estimation between groups. 2-2 In the time estimation of 250 m. distance run, both groups had a tendency of under estimation. The longer the distance was, the more variable the time estimation was. Results are discussed in terms of intermediating factors