Sub-Zero Treatment of Quenched Steel. I : On the Stabilization of Retained Austenite

As a fundamental study of sub-zero treatment of steel, the effects of quenching temperature, room temperature aging and tempering on the stabilization of retained austenite were examined. The stabilization of retained austenite was promoted by aging, because the martensite transformation rate due to subsequent sub-zero cooling was increased by the increase in aging, and moreover, when aging increased, the martensite transformation rate passed through a maximum. The martensite transformation due to subsequent sub-zero cooling gave rise to the burst transformation when aging increased to a certain degree. The remarkable increase in the stabilization was caused by the increase in the amount of prior martensite, though the stabilization occurred without prior martensite. It was suggested that the stabilization of austenite was caused by a mechanism similar to age-hardening

Effect of Cooling Rate on A_3 Transformation Temperatures of Iron and Iron-Nickel Binary Alloys

Effects of cooling rate on A_3 points of a few pure irons, iron-low carbon alloys and iron-nickel alloys have been examined at cooling rates between 100℃/sec and 60, 000℃/sec by using a gas quench apparatus. A_3 point of iron containing less than 0.003 wt% C falls gradually with the increase in cooling rate and continuously approaches a fixed temperature (maximum supercooled A_3), but in the iron containing more than 0.006 wt% C it falls discontinuously to the Ms temperature at the cooling rate of about 20, 000℃/sec. Maximum supercooled A_3 points of these irons are affected seriously by a very small content of carbon below 0.005 wt% C, falling remarkably from about 720℃ at 0.001 wt% C to about 650℃ at 0.003 wt% C with increasing carbon content. In the case of iron-nickel alloys it falls with increasing cooling rate and discontinuously by about 100℃ at a certain cooling rate which depends on the nickel content. The drop of the transformation temperature is independent of a further cooling rate. The critical cooling rate decreases from about 25, 000℃/sec at 1% Ni to about 2, 000℃/sec at 20% Ni. The Ms points of these alloys are in agreement, at higher nickel concentrations, with those reported previously, but are displaced to a lower temperature side at lower nickel concentration

Effect of Mergocriptine on Ischemia-induced Brain Damages

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Partial migration and effects of climate on migratory movements of sika deer in Kirigamine Highland, central Japan

Studies on migration pattern of sika deer in Japan are limited. We captured 27 sika deer and identified movement for 24 deer (17 females and 7 males) from 2008 to 2011 in Kirigamine Highland, Nagano, central Japan. Four juvenile males dispersed from their original home range, and we documented migration pattern for 23 deer (17 females and 6 males), including 3 dispersed males. Deer exhibited partial migration, regardless of sex: 65% (n = 15) of the deer were migratory, whereas 35% (n = 8) were non-migratory. All but 1 of the migratory deer migrated between high-elevation summer range and low-elevation winter range. Mean migration distance was 9.9 km (range = 3.2-22.9 km). Fidelity to summer home range was stronger than fidelity to winter home range. In order to determine the effect of climate on the onset of migration at Kigiramine Highland, we examined 39 seasonal movements during 4 migratory periods. Most of autumn migrations occurred before the snow depth reached 20 cm. Spring migrations occurred after the daily temperatures > 0 degrees C persisted for more than 3 days, and during periods when either snow had completely disappeared or snow melted rapidly.ArticleMAMMAL STUDY. 37(4):331-340 (2012)journal articl

Relationship between the Effectiveness of Arthrocentesis under Sufficient Pressure and Conditions of the Temporomandibular Joint

Background. The purpose of this study is to investigate the conditions of the temporomandibular joint relative to the effectiveness of an arthrocentesis-like enforced manipulation technique followed by irrigation under high pressure in patients with closed lock. Methods. We performed arthroscopic examination and manipulation followed by irrigation as the initial treatment in 50 joints with closed lock. Relationship between the effectiveness of the procedure and conditions of the temporomandibular joint was statistically analyzed using multiple regression analysis. Results. Significant inverse correlations were found between the extent of improvement in maximum mouth opening after treatment and the initial maximum opening before treatment. There were no significant correlations between improvement of joint pain at mouth opening and in biting and conditions of the temporomandibular joint. Conclusions. Pathologic conditions of the temporomandibular joint did not have an influence on the efficacy of the technique. This result suggests that this procedure has wider application than conventional arthrocentesis

Effect of Cyclic Heat-Treatments on the Martensitic Transformation in Iron-Nickel Binary Alloys

The effect of the cyclic heat-treatments on the martensitic transformation was examined with iron-nickel binary alloys containing 24.50 to 30.70 atomic per cent nickel from the observations of dilatation curves, microstructures and mechanical properties. Ms temperatures lowered with the increase in the number of cyclic heat-treatments so that the amount of martensite transformed also decreased. The optical and the electron microstructures of martensite after cyclic heat-treatments consisted of finer martensite plates with high dislocation density. The hardness and the tensile strength of austenite were remarkably increased by cyclic heat-treatments at an early state, but in the case of martensite they were not remarkably increased. It was suggested that these results would be explained by mechanisms based on the hardening of austenite and the partial decomposition of martensite due to the cyclic heat-treatments

An initial record of a long-distance dispersal route of a male sika deer in central Japan

Mammalia. 84(1), 63-68 (2019)journal articl