Microstructure and thermoelectric properties of Heusler Fe2VAl thin-films

Heusler-type Fe₂VAl thin-films were prepared on zirconia substrate by radio-frequency magnetron sputtering. The effect of deposition temperature on crystal structure and electrical properties was investigated. The degree of Heusler-type ordering in crystal structure was enhanced by the increase in deposition temperature. The enhanced Heusler-type ordering contributed to the formation of a steep density of state derived from pseudogap opening near Fermi level, resulting in large Seebeck coefficient. Since the film consisted of submicrometer-size grains, the electrical conductivity and the thermal conductivity of the film were both reduced by the grain boundary effect. The estimated thermoelectric power factor was 1.0 mW/mK² at 350 K.     

Structure and Thermal Analyses of MAA‐Grafted Silk Fiber Using DSC and 13C Solid‐State NMR

Summary: By using DSC, ¹³C CP/MAS NMR and SEM, we studied the physical properties and chemical structure of silk fibers grafted with methacrylamide (MAA). At a given MAA concentration, the inverse of fiber weight gain linearly increased with increasing square root of the initiator concentration, and at a given initiator concentration the fiber weight gain increased with increasing MAA concentration. ¹³C CP/MAS NMR demonstrated that the primary and secondary structure remained unchanged, regardless of MAA grafting, implying the poor compatibility and the lack of new additional hydrogen bonding between the silk fiber and the MAA graft polymer. The degree of grafting in MAA‐grafted silk fiber (the accurate amount of actually loaded MAA polymer within the fiber matrix) can be evaluated from determination of the ratio of heat capacities calculated from two individual endothermic DSC peaks of silk fibroin and MAA polymer. The major endothermic peaks attributable to thermal degradation of the silk fiber and MAA graft polymer shifted to a higher temperature with increasing fiber weight gain by grafting. These findings are useful for the industrial production of grafted silk fiber with higher thermal stability.

CP/MAS spectra for poly(MAA) grafted silk and control silk fiber.     

Country domain governance: an analysis by data-mining of country domains

Along with protocols, domain names are critical internet resources. To build a safe, secure, and globally ubiquitous internet, all entities responsible for the governance of domains must allocate their lower-level domains with competence and discipline following the basic principle of decentralized governance. The governance and operation of a country code top-level domain is delegated to the governing and operating entity of the relevant country or territory. There are great differences among these entities in domain allocation policy, fees, discipline, and technical competence. The undertaking of governing a global infrastructure requiring high integrity, such as the internet, on the basic principle of decentralized governance is unprecedented. To enable this governance to work well, it is necessary to set up proper objectives for the governance of country domains, and to use highly transparent criteria for a multi-faceted evaluation of how far these objectives have been achieved. This article presents a set of country domain governance indicators which is intended to be used for the construction of a safe and secure ubiquitous global network.     

Photocatalytic O2 evolution under visible light irradiation on BiVO4 in aqueous AgNO3 solution

BiVO₄ with a 2.3 eV band gap showed an activity for O₂ evolution from aqueous solutions containing Ag⁺ as an electron scavenger under visible light irradiation (λ > 520 nm). The quantum yield was 0.5% at 450 nm. This revised version was published online in July 2006 with corrections to the Cover Date.     

Inactivation of rifampin by Nocardia brasiliensis

Rifampin was glycosylated by a pathogenic species of Nocardia, i.e., Nocardia brasiliensis. The structures of two glycosylated compounds (RIP-1 and RIP-2) isolated from the culture broth of the bacterium were determined to be 3-formyl-23-(O-[beta-D-glucopyranosyl])rifamycin SV and 23-(O-[beta-D-glucopyranosyl])rifampin, respectively. Both compounds lacked antimicrobial activity against other gram-positive bacteria as well as the Nocardia species.     

Traumatic dislocation of the testis]

Dislocation of the testis is a rare injury, with only 73 cases having been reported in Japan. We herein add 6 cases. Lately, accidents involving teenage patients, primarily involving motorcycles, have been increasing. Closed reduction is recommended, but it was successful only 5 of 73 cases. The results of testicular biopsies suggest that early surgical management is required when closed reduction is unsuccessful.     

A new DSP-oriented algorithm for calculation of the square rootusing a nonlinear digital filter

A high-speed algorithm for calculating the square root is proposed. This algorithm, which can be regarded as calculation of the step response of a kind of nonlinear IIR filter, requires no divisions. Therefore, it is suitable for a VLSI digital signal processor (DSP) which has a high-speed hardware multiplier but does not usually have a high-speed hardware divider. The convergence properties of the algorithm are analyzed and used to develop a practical implementation of the procedure. It is implemented on the commercially available DSP (TM320C25) and is compared with the Newton-Raphson method. The proposed algorithm has two advantages over the Newton-Raphson method: higher execution speed and smaller calculation error     

Fine structure and development of the collar enamel in gars, Lepisosteus oculatus, Actinopterygii

The fine structure of collar enamel and the cells constituting the enamel organ during amelogenesis in Lepisosteus oculatus was observed by light, scanning electron and transmission electron microscopy. In the enamel, slender crystals were arranged perpendicular to the surface and the stripes that were parallel to the surface were observed, suggesting that the enamel in Lepisosteus shares common morphological features with that in sarcopterygian fish and amphibians. Ameloblasts containing developed Golgi apparatus, rough endoplasmic reticulum (rER) and secretory granules were found in the secretory stage. In the maturation stage, a ruffled border was not seen at the distal end of the ameloblasts, while many mitochondria and lysosome-like granules were obvious in the distal cytoplasm. The enamel organ consisted of the outer dental epithelial cells, stratum reticulum cells and ameloblasts, but there was no stratum intermedium. It is likely that the ameloblasts have less absorptive function in comparison with the inner dental epithelial cells facing cap enameloid.