A Minicomputer-Based Continuous Annealing System for Mechanical Filter Long Elinvar Wire

This paper presents an annealing system which can continuously fabricate mechanical filter-long elinvar (Fe-Nl-Co-Cr syntax compound metal) wire having uniform sound-velocity. In electromechanical filter automatic mass production, several hundred meter long coupling wire (0.15 - 0.30 mm?) having uniform sound-velocity (fluctuation is within ±0.4 percent) is required.     

Procedures for stereological estimation of structural anisotropy

Actual procedures are given for detecting structural anisotropy by the stereological method, i.e. by observing only cross-sections in the material, on the basis of the theoretical formulation of the previous article [1]. First, computation by the Monte Carlo method is described explicitly in terms of observed data, determining the distribution density completely. Next, alternative procedures are given by the use of restricted cross-sections on the assumption that the anisotropy is “weak,” facilitating actual experiments a great deal. Observations are made only on planes parallel to the three coordinate planes or cylindrical surfaces around the three coordinate axes. “Fabric tensors” describing the anisotropy and the “equivalent strain” are given explicitly in terms of observed data.     

Hydrogen trapping and repelling in an Al-6 wt % Zn-2 wt % Mg alloy

Hydrogen trapping in an Al-6 wt % Zn-2 wt % Mg alloy aged up to typical stages in the agehardening curve has been studied by measuring the tritium release rate after charging. The distribution of hydrogen in the aged alloy has been studied by tritium electron microautoradiography. It has been found that the Guinier-Preston zones in the alloy do not act as trapping sites but as a repeller for hydrogen, and that precipitate does not trap hydrogen, but the interface between the matrix and precipitate acts as a trapping site for hydrogen. Dislocation has been found to be capable of trapping hydrogen, while trapped hydrogen by the grain boundary has not been observed.     

Photoinduced antiviral carbon nanohorns

Nanocarbons, such as carbon nanohorns (CNH) and carbon nanotubes, are materials of interest in many fields of science and technology because of their remarkable physical properties. We report here a novel approach for using NIR laser-driven CNH as an antiviral agent. NIR laser-driven functional CNH complexes could open the way to a new range of antiviral materials.     

Application of hydrogel for the removal of pollutant phenol in water

We prepared hybrid hydrogel of N-isopropyl acrylamide (NIPAM) and tributyl phosphate (TBP) for removing phenol by adsorption. The hybrid hydrogel was reinforced by thin layer coating of calcium alginate gel which was cross-linked by bivalent calcium ions. The prepared hybrid hydrogel was shown to effectively adsorb phenol from aqueous solution. The adsorption kinetic measurement showed that the thin layer coating of calcium alginate gel hardly hindered the mass transfer process of phenol. This is because of the superior hydrophilicity of calcium alginate gel which allows phenol molecules to diffuse in the hybrid hydrogel. The reinforced hybrid gel could be stripped of the adsorbed phenol with ammonia aqueous solution for multiple times. The thin layer coating of calcium alginate provided the hybrid hydrogel sufficient durability to carry out repeated cycles of adsorption and desorption.     

Selective permeation and separation of steam from water–methanol–hydrogen gas mixtures through mordenite membrane

Separation properties of a mordenite membrane for water–methanol–hydrogen mixtures were studied in the temperature range from 423 to 523 K under pressurized conditions. The mordenite membrane was prepared on the outer surface of a porous alumina tubular support by a secondary-growth method. It was found that water was selectively permeated through the membrane. The separation factor of water/hydrogen and water/methanol were 49–156 and 73–101, respectively. Even when only hydrogen was fed at 0.5 MPa, its permeance was as low as 10⁻⁹ mol m⁻² s⁻¹ Pa⁻¹ up to 493 K, possibly suggesting that water pre-adsorbed in the micropores of mordenite hindered the permeation of hydrogen. The hydrogen permeance dramatically increased to 6.5 × 10⁻⁷ mol m⁻² s⁻¹ Pa⁻¹ at 503 K and reached to 1.4 × 10⁻⁶ mol m⁻² s⁻¹ Pa⁻¹ at 523 K because of the formation of cracks in the membrane. However, the membrane was thermally stabilized in the presence of steam and/or methanol.     

Dielectric relaxations in poly(vinyl alcohol)

Dielectric constant and loss of poly(vinyl alcohol) films of different stereoregularity and crystallinity are measured at frequencies from 30 cps to 3 Mcps in the temperature range from ?50 to 25°C. The relaxation strength of local mode relaxation is higher for atactic and syndiotactic samples than for isotactic samples when compared at zero crystallinity. This behavior is reasonably explained in terms of interchain hydrogen bonds in the former and intrachain hydrogen bonds in the latter. Dielectric constant and loss of the crystal aggregate of atactic poly(vinyl alcohol) are measured at temperatures from ?50 to 140°C. The relaxation strength of the crystalline relaxation is in good agreement with the theory in which the relaxation is attributed to torsional vibration of crystalline chains. The weak loss peak at low temperatures which almost agrees with the local mode relaxation of bulk samples in the frequency-temperature position is ascribed to the surface disorder of single crystals.     

RNA-Binding Protein MAC5A Is Required for Gibberellin-Regulated Stamen Development

The development of floral organs is coordinated by an elaborate network of homeotic genes, and gibberellin (GA) signaling is involved in floral organ development; however, the underlying molecular mechanisms remain elusive. In the present study, we found that MOS4-ASSOCIATED COMPLEX 5A (MAC5A), which is a protein containing an RNA-binding motif, was involved in the development of sepals, petals, and stamens; either the loss or gain of MAC5A function resulted in stamen malformation and a reduced seed set. The exogenous application of GA considerably exacerbated the defects in mac5a null mutants, including fewer stamens and male sterility. MAC5A was predominantly expressed in pollen grains and stamens, and overexpression of MAC5A affected the expression of homeotic genes such as APETALA1 (AP1), AP2, and AGAMOUS (AG). MAC5A may interact with RABBIT EARS (RBE), a repressor of AG expression in Arabidopsis flowers. The petal defect in rbe null mutants was at least partly rescued in mac5a rbe double mutants. These findings suggest that MAC5A is a novel factor that is required for the normal development of stamens and depends on the GA signaling pathway.     

Direct methanol fuel cell performance of sulfonated polyimide membranes

Sulfonated polyimides (SPIs) derived from 1,4,5,8-naphthalene tetracarboxylic dianhydride, 4,4′-bis(4-aminophenoxy) biphenyl-3,3′-disulfonic acid and hydrophobic aromatic diamines showed the much lower methanol permeability and the lower proton conductivity than Nafion 112. The performance and the water and methanol crossover for direct methanol fuel cells (DMFCs) with the SPI membranes were investigated in comparison with Nafion membranes. The methanol and water fluxes increased significantly with increasing load current density for Nafion membranes but not for the SPI membranes, indicating that they were controlled by both the electro-osmotic drag and the molecular diffusion for the former but by only the molecular diffusion for the latter. These resulted in the much better DMFC performance for the SPIs than Nafion membranes especially at high methanol feed concentrations. The Faraday's efficiency and overall DMFC efficiency at 60 °C and 200 mA cm⁻² for SPI membrane with IEC of 1.51 meq g⁻¹ were 75% and 21%, respectively, at 5 wt.% methanol feed concentration, and 36% and 9.5%, respectively, at 20 wt.% methanol concentration. They were about two times and three times higher at 5 wt.% and 20 wt.% methanol concentrations, respectively, than those for Nafion 112. The short-term durability test for 300 h at 60 °C revealed no deterioration in the DMFC performance. The SPI membranes have high potential for DMFC applications at mediate temperatures (40–80 °C).     

Preparation of an acrylic‐grafted polyester and its aqueous dispersion: Grafting utilizing alternating copolymerization

An investigation was undertaken to develop a new method to obtain fine dispersion of grafted polyester without gelation. As a new method, grafting utilizing alternating copolymerization of hydrophilic polymers to unsaturated polyester was discussed. By use of grafting utilizing alternating copolymerization, the reaction tendency of grafted polymer radical for an unsaturated bond of the polyester was changed. The grafting utilizing alternating copolymerization was compared with the conventional grafting, and the calculated grafting efficiency is about twice. Moreover, it was possible to increase the incorporation of less reactive monomers into the grafted side chain by the grafting utilizing alternating copolymerization. From the above results, the grafting utilizing alternating copolymerization is considered a useful method to prepare grafted polymers. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1395–1403, 1999