Anelastic Relaxations of La-based Amorphous Alloys

The relaxation processes of La-based amorphous alloys with distinct glass transition phenomenon have been investigated in the temperature regions around the glass transition temperature and well below the glass transition temperature by the dynamic mechanical measurements. The amorphous alloys used in this study are La_Al_Ni_x (x=0 to 35 %) and La_5Al_Ni_ alloys for examination of the compositional effect and La_Al_M_ (M=Cu, Pd or Au) alloys for the substitutional effect. The sub-T_g relaxation phenomenon was observed for La_Al_Ni_x (x=5 to 35 %) and La_5Al_Ni_ amorphous alloys. The relaxation due to the glass transition was recognized for La_Al_Ni_x (x=0 to 35 %), La_5Al_Ni_ and La_Al_M_ (M=Cu, Pd or Au) amorphous alloys. In addition, the second-stage relaxation in the glass transition region was also observed for La_Al_Ni_x (x=15 to 30 %) and La_Al_M_ (M=Cu, Pd or Au) amorphous alloys with a wide supercooled liquid region exceeding 35 K. The appearance of the two kinds of relaxation units seems to reflect the difference in the chemical bonding nature among the constituent elements

女性尿道と膣の形成に関する局所解剖 : ヒト胎児を用いた組織学的研究

Background: Which parts of the male urethra correspond to the female urethra? To resolve this question, we need to understand fetal topographical changes in the urethra, its external sphincter and vagina. The vagina joins the mid-course of the primitive urethra and, later “descends” to the vaginal vestibulum. Methods: We examined histological sections of 14 female and 4 male mid-term fetuses. Results: The inferior end of the vagina was consistently embedded in the posterior wall of the urethra at 9-12 weeks. The supero-inferior level of the vaginal merging was lower in larger fetuses. Thus, the sequential variation in levels appeared to reflect the process of vaginal descent. However, in spite of penetration of the vaginal end into the posterior urethral wall, we found no sign of destruction of the urethral wall after vaginal descent in the low-merging types. Before vaginal descent, the female external sphincter extended posterolaterally around the urethra. Conclusion: The vaginal descent is classically regarded as a relative topographical change, but it is likely to be a result of elongation of the proximal urethra in the superior side of the vaginal merging. Conversely, the distal urethra is likely to be incorporated into the vaginal vestibulum by 15 weeks. During these processes, most of the female external sphincter seems to be expelled from the original anterior position into the vestibular wall as the urethrovaginal sphincter. The adult female urethra seems to correspond to the male prostatic urethra superior to the prostatic colliculus.広島大学(Hiroshima University)博士(医学)Philosophy in Medical Sciencedoctora

Fabrication and Applications-Oriented Properties of Amorphous Metal Matrix Composites

This article briefly reviews our study on fabrication and applications-oriented properties of amorphous metals matrix composites

Fracture Toughness of Amorphous Metals

The fracture toughness of some amorphous metals has been measured as functions of the temperature and strain rate by using a tear test of a trouser-leg type. The tearing energy measured by this method and the fracture toughness estimated by Irwin\u27s relation were compared with those of various other materials. These values for amorphous metals are comparable with those for strong steels, and are very high compared with inorganic glasses and polymers. By using the values of tearing energy, the ideal yield stress for various amorphous metals was estimated to be about two times the nominal yield stress, possibly because stress concentration at defects preexisted in the specimens

Disorder-induced transition from Gaussian to dispersive carrier transport in molecularly doped polymers

Dynamics of hopping charge transport in a polymer matrix doped with two different charge-transport molecules was studied by means of time-of-flight (TOF) photoconductivity measurements. In polymers doped with two molecules of little different ionization potential, the Gaussian (near-rectangular) TOF signal was observed over all compositions and the tail of the Gaussian TOF signal is broadened by a wide distribution of hopping time among molecules due to off-diagonal disorder. On the other hand, in polymers doped with two molecules of different ionization potential, the transition from the Gaussian to the dispersive TOF signal was observed and this is mainly caused by diagonal disorder. It is found that the energetic and spatial distribution of hopping sites play a key role in carrier transport in molecularly doped polymers

Effects of olive oil in SAMP8 mice

Background : Mediterranean diets have been linked to a reduced risk of cancer, vascular illnesses, Parkinson’s and Alzheimer’s disease. Olive oil is the primary fat source in the Mediterranean diet ; however, only a few studies have investigated the effect of olive oil on aging. In the present study, we aimed to determine whether consumption of olive oil significantly influences aging and memory in senescence-accelerated mouse-prone 8 (SAMP8). Methods : SAMP8 and senescence-accelerated mouse resistant 1 (SAMR1) mice were fed either 7% soy oil or 1% olive oil and 6% soy oil during a six-month study period. Reduction in memory in passive avoidance learning was examined after two months from the initiation of the experiment. Results : The weight of organs including the liver, kidney, spleen, and fat tissue changed significantly and memory performance was reduced in SAMP8 than in SAMR1 mice. There were no significant differences in SAMP8 and SAMR1 mice; however, blood triglyceride level decreased significantly in SAMP8 mice fed on olive oil. Conclusions : These results suggest that consuming olive oil may not have a protective role in aging and memory recall, but beneficial effects may be related to improvement in lipid metabolism