Interfacial Debonding Behavior of Mullite/SiC Continuous Fiber Composite

Mullite/SiC continuous fiber composites were fabricated by hot-pressing under different processing conditions. The interfacial shear strength was measured during the pull-out test, and the effect of fabrication conditions on interfacial debonding behavior was discussed. The debonding length during the pull-out test was quantitatively evaluated using acoustic emission. The interfacial shear strength was evaluated by stress analysis. The control of interfacial shear strength was achieved by controlling the hot-press temperature. An increase of load was found during the pull-out process after complete debonding. In order to explain the increased load, a new model is presented.     

Composition dependence of the oxygen-evolution reaction rate on Ir x Ti1−x O2 mixed-oxide electrodes

Mudcrack-free oxide films of Ir _x Ti_1–x O₂ (0 < x 1) on titanium substrates were obtained, and the effects of the oxide composition on the rate of oxygen-evolution reaction were investigated. At x 0.6, Ir-rich grains appear on the mudcrack-free surface. In the purely single-phase region (0 < x 0.5), the pseudo-capacitive charge is proportional to the surface composition, x _s, and the exchange-current density for the oxygen-evolution reaction increases linearly with x _s at 0.2 x _s 0.5, with an extrapolated intercept at x _s 0.15, below which the oxides are inactive.     

The effect of polystyrene as a porogen on the fluoride ion adsorption of Zr(IV) surface-immobilized resin

A novel adsorbent, Zr(IV)-immobilized resin, was prepared by surface template polymerization. This adsorbent, prepared by adding polystyrene (PS) to resin, has a high adsorption capacity for the removal of fluoride ion from aqueous solutions. The adsorption capacity increased with rising PS concentration, since the specific surface area can be effectively increased by adding polystyrene as a porogen. The adsorption isotherm has been modeled by the Langmuir and Freundlich equations. The adsorption isotherms were well described by the Langmuir equation. The removal of fluoride was also carried out using a column method. The presence of PS in the resin exerted a remarkable influence on the uptake of fluoride ion. The fluoride adsorbed on the resin was quantitatively eluted with 0.1 M NaOH.     

Mechanism of increased serum cytokeratin 19 fragment levels in patients with diabetic nephropathy as a model of chronic renal failure

We examined serum and urinary cytokeratin 19 fragment (CYFRA 21-1) levels in patients with diabetic nephropathy as a model of chronic renal failure, to investigate the mechanism of increased serum CYFRA 21-1 levels in chronic renal failure. Serum and urinary CYFRA 21-1 levels in non-insulin-dependent diabetes mellitus (NIDDM) patients with abnormal urinary immunoglobulin G (IgG) levels (>1.1 mg/g x Cr, n=126) were higher than those with normal urinary IgG levels. In NIDDM patients with normal urinary IgG levels (n=81); the urinary albumin or transferrin levels were not related to serum or urinary CYFRA 21-1 levels. We speculate that the increased serum CYFRA 21-1 levels contribute to metabolic abnormality in the kidney itself rather than the decreased urinary excretion per se, and that increased urinary CYFRA 21-1 levels are found in advanced cases of diabetic nephropathy with destruction of the size barrier.     

Whole body hyperthermia selectively induces heat shock protein 72 in neurons of the rat spinal cord

Rabbits with lesions of either medial prefrontal cortex (mPFC) or amygdala central nucleus (ACN) were compared with sham-lesioned animals during differential and reversal classical conditioning of the eyeblink (EB) and heart rate (HR) response. Lesions of the mPFC, but not ACN, produced a severe impairment in EB reversal conditioning, but neither lesion affected original discrimination. However, both mPFC and ACN lesions produced a severe attenuation of accompanying HR decelerations during both initial differentiation and reversal. These results suggest that mPFC processing of Pavlovian conditioning contingencies affects not only the autonomic component of learning but preservative somatomotor conditioning as well, whereas ACN processing affects only the autonomic component.     

A new apparatus for measuring total hemispherical emittance of surfaces at room temperature

Radiation heat transfer is an important mode of heat transfer even in our life space at room temperature. Such radiation heat transfer is evaluated mostly by calculating the radiation energy exchange among surfaces in an enclosure. For this evaluation, knowledge of the hemispherical emittances of the constituent life surfaces is needed. However, there has not been a suitable technique for measuring the emittance of each surface in the life space at room temperature. In the present work we develop a new apparatus for measuring total hemispherical emittances of real surfaces at room temperature. The apparatus consists of a total radiation flux meter and a Peltier element cooler to cool the flux meter surface from the back, and measure the net total radiation flux from the specimen surface to the surrounding surfaces to determine the total hemispherical emittance of the specimen surface. This apparatus is effective to measure total hemispherical emittances of surfaces at room temperature on site. We apply the developed apparatus to measure the total hemispherical emittances of various surfaces in the life space, such as metals, human skin, cloth, floor mat, wood, glass, brick tile, stone, cement, plant leaves, etc., and demonstrate the feasibility of the apparatus. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.20349     

Hypocholesterolemic action of chitosans with different viscosity in rats

The relationship between hypocholesterolemic efficacy and average molecular weight of chitosan was studied in rats fed a cholesterol-enriched (0.5%) diet. Several chitosan preparations with a comparable degree of deacetylation but differing widely in average molecular weight, as demonstrated by viscosity, almost completely prevented the rise of serum cholesterol at the 5% dietary level. At the 2% level, chitosans with viscosities at both extremes exerted a comparable cholesterol-lowering action. The glucosamine oligomer composed mainly of three to five aminosugar residues was not effective. The results indicate that the hypocholesterolemic action of chitosans is independent of their molecular weight within the tested viscosity range.