No abstract

Fe-0.002010C. Fe-0.01010C. Fe-1 .50/0Mn-0.0010/0C and Fe-1 .50/0Mn-0.010/oC steels were vacuum-melted and examined.

The most serious problem in the recycling of steel is the occurrence of surface hot shortness during hot deformation due to the mixing of Cu from scrap into steels. Tin accelerates the effect of Cu. The surface hot shortness is caused by liquid embrittlement, that is, formation of the liquid Cu-enriched phase through preferential oxidation of Fe atoms at the steel/scale interface during heating for hot deformation and penetration of this Cu-enriched phase into the grain boundaries. Decrease in the amount of the liquid Cu-enriched phase penetrating into grain boundaries can suppress the surface hot shortness. The amount of the liquid Cu-enriched phase penetrating into the grain boundaries can be reduced by the suppression of oxidation, occlusion of the Cu-enriched phase into the scale, back-diffusion of Cu into the steel matrix and suppression of penetration of the liquid Cu-enriched phase. Therefore, the effects of various elements and conditions of heating and deformation on the surface hot shortness, oxidation, amount of the Cu-enriched phase at the interface and the penetration were examined by tensile tests at high temperatures, thermogravimetry and optical microscopy. The conclusion can be summarized as follows. Silicon, Mn, S (+Mn) and B reduce the susceptibility to the surface hot shortness through decreasing the amount of Cu-enriched phase at the steel/scale interface. The effect of Si is significant. Carbon reduces the oxidation rate in LNG combustion gas. Phosphorus, Si, B and C reduce the susceptibility to the surface hot shortness through restraining the penetration of the Cu-enriched phase into grain boundaries. Heating at higher temperatures reduces the susceptibility mainly through a reduction in the amount of the Cu-enriched phase at the steel/scale interface, although the loss of steels by oxidation increases. A large grain size accelerates the surface hot shortness. A small amount of H 2 O in air significantly accelerates the surface hot shortness. Effects of H 2 O in heating atmosphere depend on the steel composition and more detailed research on this is desired. Very slow deformation does not cause liquid embrittlement through dynamical re-crystallization, while at a fast deformation rate the embrittlement is suppressed by an increase in the critical stress for the liquid embrittlement. Multiple methods using physical metallurgy suggested by the present research for suppressing the surface hot shortness should be applied together with other methods through separation, smelting and design of fabrication in order to promote the recycling of steels.

Counting and sizing large farmed fish such as tuna is often performed during their transfer from one net cage to another. Dual-frequency identification sonar (DID-SON) provides an automated fish counting and sizing tool. However, its counter and sizer are not suitable for measuring farmed fish because of net movements due to currents and subsequent frequent image breakups. This paper presents a fully automated acoustic method to count and size farmed fish during fish transfer by using DIDSON imaging. The background is subtracted from the image after being stabilized by an image phase-only correlation method. The segmentation of the fish is obtained by tracing the edges with a contour tracing method. To prevent recounting the same fish, a Kalman filter algorithm was designed and adapted to predict fish movements. Automated counting was performed by analyzing the spatiotemporal trajectory of the track. The separated fish images were searched for and body length was obtained by summing down the centerline segments from the head to the tail of the fish. The proposed system was verified using farmed yellowtail, Seriola quinqueradiata (mean total length 83.1 cm) to obtain a sizing error of mean total length within 2.4 cm.

The objective of this paper is to examine the effects of Si

The dependence of nonreciprocity of excitation of magnetostatic surface waves (MSSW) on antenna width was investigated experimentally and theoretically. The nonreciprocity was successfully modified by changing the excitation antenna width. The nonreciprocity ratio, which was defined as the spin wave intensity under negative bias field divided by that under positive bias field, was found to decrease with increasing antenna width. Micromagnetic simulations revealed that this decrease in the nonreciprocity ratio originates from the rapid decrease in the in-plane excitation field compared to the perpendicular excitation field with reducing the antenna width.

The dietary factors, as a cause on increasing incidence of gallstones in Japan, were studied. The increase in the incidence of gallstones at autopsy was nearly paralleled with that of fat intake on a line graph and reversely the carbohydrate intake including crude fiber showed a decreasing trend. In the nutritional survey of patients with gallstone, the fat intake was 22% higher than that of the control group, and the crude fiber intake was 18%lower. Comparing the incidence of cholesterol stones during each 10 years of 1953-1962 and 1969-1980 with the nutritional intake, the incidence of gallstones increased by 25% and the fat intake by 120%, but the carbohydrate intake including crude fiber decreased by 14%. Fromthe above, it was considered that the increase of the incidence of cholesterol gallstones was related to the increase of the fat intake and the decrease of the crude fiber intake. A study on black stone was carried out with an infrared spectroscopic analysis and scanning electron microscopic observation, and wenowproposed a new classification of this type of stones.

No abstract