Quenched metastable phases and their transformations on heating in the Bi2O3-WO3 system

A single-roller apparatus was used to quench 16 melts in the Bi₂O₃-WO₃ system. Metastable polycrystalline phases were obtained in all compositions. Quenched specimens and their phase transformations on heating were examined by X-ray diffraction, differential thermal analysis, density measurement, electrical measurement and observation of optical anisotropy. F c c solid solutions of the type, 2WO₃ 2W ^Bi + 30 ^pI +30 _X ^PO occurred in the quenched samples for 18 to 32 mol % WO₃. Quenched phases remained unchanged with only a slight structural relaxation at temperatures lower than the first exotherm. Near the first exotherm, most samples showed an irregular change in the lattice parameter(s).     

Thermosensitive dielectric properties in polyamide–phenol hybrid compounds and their application to the temperature-sensing wire

Thermosensitive dielectric properteis in polyamide–phenol hybrid compounds have been studied. The polyamide–phenol hybrid compounds are constituted of p-hydroxybenzoate–formaldehyde condensation oligomer dispersed molecularly in nylon 12 and polyamide copolymer. These materials are less hygroscopic than nylon 12 which is the least hygroscopic among polyamide homopolymers. It will be because the phenol group coordinates to amide group as the less hygroscopic “pseudo-water” instead of water. One of these materials has also shown an intrinsic hydrophobic effect of hydrogen bond segment due to the “hybrid effect” between polyamide and phenol. The thermosensitive dielectric properties are based on the temperature dependence of intermolecular hydrogen bond behaviors by amide and phenol groups, which have been discussed in relation with the molecular behaviors. The relationship with polarizations constituting dielectric constant and hydrogen bonding molecular segments, and ac hopping conduction behaviors by proton carriers have also been discussed. These materials are applied as a temperature-sensing material in a flexible thermosensing heater wire, which has three functions, that is, thermosensing, heating, and fusing for safe in the case of an abnormal overheat. As the features for a sensing material, these materials show the humidity low-dependence and highly thermal stability, and will be situated as one of the high-performance sensing material useful for the electric warmer such as an electric blanket.     

STDP provides the substrate for igniting synfire chains by spatiotemporal input patterns

Spike-timing-dependent synaptic plasticity (STDP), which depends on the temporal difference between pre- and postsynaptic action potentials, is observed in the cortices and hippocampus. Although several theoretical and experimental studies have revealed its fundamental aspects, its functional role remains unclear. To examine how an input spatiotemporal spike pattern is altered by STDP, we observed the output spike patterns of a spiking neural network model with an asymmetrical STDP rule when the input spatiotemporal pattern is repeatedly applied. The spiking neural network comprises excitatory and inhibitory neurons that exhibit local interactions. Numerical experiments show that the spiking neural network generates a single global synchrony whose relative timing depends on the input spatiotemporal pattern and the neural network structure. This result implies that the spiking neural network learns the transformation from spatiotemporal to temporal information. In the literature, the origin of the synfire chain has not been sufficiently focused on. Our results indicate that spiking neural networks with STDP can ignite synfire chains in the cortices.     

Polyimide-based X-ray masks with advanced performance of pattern accuracy and thermal stability

Polyimide-based X-ray masks which are generated by optical lithography and electroplating of gold absorbers on a polyimide mask membrane gain attention as low cost masks. The organic membranes generally have problem of (1) pattern edge sharpness, (2) miniaturization of pattern and (3) thermal stability. To make the masks commodity in deep and accurate lithography area, Optnics Precision, Japan, has overcome the above difficulties and realized the masks with advanced performance of pattern accuracy and thermal stability by improving the making process and the material. Good results were obtained in the exposure experiment that used this mask. When this X-ray mask is combined with the electroforming technique and the material development technique that Optnics has, the application to various fields like an industrial field and medical field can be expected.     

天边一朵云 HOTO FUDO餐厅

HOTO FUDO坐落在富士山下一个道路交叉口,两个面都朝向公路。这是一间山梨县传统面食＂乌冬＂餐厅,其设计极具创意,极富美感,且具有独特的亚洲风味。建筑设计的灵感取自山峦和云端等大自然景物,没有方形和圆形的外观,     

Review of Topographic and Soil Conditions for Liquefaction-Related Damage Induced by the 2007 Off Mid-Niigata Earthquake

The 2007 Niigata-ken Chuetsu-oki (Off Mid-Niigata) earthquake caused the liquefaction of the sandy soil distributed near the coast of the Japan Sea in the middle of Niigata Prefecture. The liquefaction-induced damage occurring in many residential areas was investigated in detail by means of victim interviews, visual inspections, Swedish Weight Sounding tests, Standard Penetration Tests, old topographical map examinations, etc. Based on in situ soil investigations, the liquefied soil layers were estimated for each area. As a result, it was confirmed that the liquefied areas were mainly sand dune hinterlands, flood plains, reclaimed old river channels and sandy fills with high groundwater table. Among them, damage was especially serious on land having an inclined ground surface due to the flow of foundations, on the cut-fill borders of artificially developed land due to landslides and at the toes of sand dune slopes due to the thrust of the sliding soil and/or the collision of the sliding soil with objects. These investigation results also revealed that soil improvement by cement mixed columns is an effective countermeasure against liquefaction-induced damage unless lateral spreading of the subsoil arises.     

Bone bonding ability of a chemically and thermally treated low elastic modulus Ti alloy: gum metal

The gum metal with composition Ti–36Nb–2Ta–3Zr–0.3O, is free from cytotoxic elements and exhibits a low elastic modulus as well as high mechanical strength. We have previously demonstrated that this gum metal, once subjected to a series of surface treatments—immersion in 1 M NaOH (alkali treatment) and then 100 mM CaCl₂, before heating at 700 °C (sample: ACaH-GM), with an optional final hot water immersion (sample: ACaHW-GM)—has apatite-forming ability in simulated body fluid. To confirm the in vivo bioactivity of these treated alloys, failure loads between implants and bone at 4, 8, 16, and 26 weeks after implantation in rabbits’ tibiae were measured for untreated gum metal (UT-GM), ACaH-GM and ACaHW-GM, as well as pure titanium plates after alkali and heat treatment (AH-Ti). The ACaH-GM and UT-GM plates showed almost no bonding, whereas ACaHW-GM and AH-Ti plates showed successful bonding by 4 weeks, and their failure loads subsequently increased with time. The histological findings showed a large amount of new bone in contact with the surface of ACaHW-GM and AH-Ti plates, suggesting that the ACaHW treatment could impart bone-bonding bioactivity to a gum metal in vivo. Thus, with this improved bioactive treatment, these advantageous gum metals become useful candidates for orthopedic and dental devices.     

Differential expression of protooncogenes in human germ cell tumors of the testis

BACKGROUND: It has been suggested that tumorigenesis of the germ cell tumor of the testis includes abnormal and developmentlike differentiation of primordial germ cells to several mature type tumors. METHODS: To clarify roles of protooncogenes in the unique tumorigenic mechanism in the human germ cell tumor, the authors examined the expression of 15 protooncogenes in human primary germ cell tumors of the testis with Northern blot analyses. RESULTS: Fifteen (94%) of 16 seminomas and 5 (83%) of 6 embryonal carcinomas had a significant levels of N-myc expression, whereas they did not express two receptor type protooncogenes, c-erbB-1 and c-erbB-2. In contrast, some immature teratomas had a high level of c-erbB-1 expression, and an advanced case showed a significant level of c-erbB-2 expression. Immature teratomas did not show N-myc expression. Higher levels of c-mos expression were observed in several cases of seminomas and embryonal carcinomas. Expression of c-Ki-ras or N-ras was observed in all histologic subgroups and normal testes. CONCLUSION: A significant level of N-myc expression may be essential for undifferentiated tumors including seminoma and embryonal carcinoma, whereas c-erbB-1 and possibly c-erbB-2 may have important roles in the differentiated tumors such as immature teratoma. These results suggest that some of the protooncogene expression may be switched critically during the differentiation from seminomas or embryonal carcinomas to the more differentiated-type tumor.