Thermodynamic and crystallographic discussion of the formation and dissociation of zircon

The mechanism for the formation of zircon from a system of Si(OC₂H₅)₄-ZrOCl₂ · 8H₂O-C₂H₅OH solution was constituted from the following steps; the formation of sol composed of an equimolar Zr⁴⁺ located in the neighbourhood of a linear siloxane polymer, deposition of metastable fine (tetragonal) T-ZrO₂ by heating, the tetragonal to monoclinic (T M) transformation of the fine T-ZrO₂ aggregates separated from the strain energy of grain boundary between two oxide components, the initiation of the interface reaction between T-ZrO₂ and amorphous SiO₂, and the acceleration of the formation by the Hedvall effect caused by the crystallization of SiO₂. The key technology for the symhesix of zircon from the oxide components ZrO₂ and SiO₂ was the mechanochemina! activation of the surface layer by milling, the formation of transition phase between the two componems by adding the guest element, and the presentation of metamorphic surface state. Zircon dissociated into M-ZrO₂ and SiO₂ glass, and the dissociation temperature was expected to be above 1700° C, which required the correction of the phase diagram for ZrO₂-SiO₂ system used previously.     

Estimation of formation mechanism of spherical fine ZrO2-SiO2 particles by ultrasonic spray pyrolysis

Spherical fine ZrO₂-SiO₂ (11) particles were synthesized from a hydrolysed mix-solution of Si(OC₂H₅)₄ and ZrOCI₂ · 8H₂O by ultrasonic spray pyrolysis, and the formation mechanism of the particles discussed. All of the resultant particles identified as t-ZrO₂ and amorphous SiO₂ with an atomic order dispersion were spherical, and mainly of diameter 0.8 to 1.0m. It was estimated that the three-dimensional ladder siloxane chains containing an equimolar Zr⁴⁺ homogeneously dispersed were formed by hydrolysis, and an atomized droplet itself converted into an isolated ZrO₂-SiO₂ (11) particle without aggregation.     

Piezoelectric properties of microfabricated (K,Na)NbO3 thin films

A novel microfabrication method of lead-free piezoelectric sodium potassium niobate [(K,Na)NbO₃, KNN] thin films was proposed, and the piezoelectric characteristics of the KNN microactuators were evaluated. The KNN thin films were directly deposited on microfabricated Si microcantilevers. The transverse piezoelectric coefficient d₃₁ of the KNN films was calculated as −53.5 pm/V at 20 V_pp from the tip displacement of the microcantilevers. However, the tip displacement showed large electric-field dependence because of the extrinsic piezoelectric effect, and the intrinsic piezoelectric effect of the KNN microcantilevers was smaller than that of KNN on unprocessed thick substrates. In contrast, the extrinsic piezoelectric effect was almost independent of the microfabrication of the KNN films.     

Optical design and roll‐to‐roll fabrication process of microstructure film for wide viewing LCDs

We have developed a new microstructure film for wide viewing liquid crystal displays (LCDs). By attaching it to the surface of a conventional LCD, the viewing angle characteristics of LCD has drastically improved without causing a blur of the frontal image and a decrease in the contrast ratio under bright ambient light conditions. This film can be applied to various LC modes including twisted nematic and multidomain vertical alignment by changing its internal micrometer‐size 3D structure. Further, this film can be mass‐produced efficiently by self alignment roll‐to‐roll process.     

Strategy for kinetic parameter estimation—Thermal degradation of polyurethane elastomers

The kinetics of the thermal degradation of polyurethane (PU) elastomers based on poly(ether polyol) soft segments and an aromatic type of diisocyanate were investigated by thermogravimetric analysis (TGA) under a nitrogen atmosphere employing four heating rates. The corresponding kinetic parameters of the two degradation stages were estimated by minimizing the output error functional and by the Kissinger method. In evaluating the kinetic parameters of the two‐step PU thermal decomposition, a differential thermogravimetry curve was applied as an objective functional in a regression procedure. Parameter estimation was obtained by minimizing the weighted quadratic output error functional with the modified Nelder–Mead simplex search algorithm. The confidence regions in the preexponential factor‐activation energy space were established for both the first and second stages of degradation. The effect of the molecular weight of the soft segment and the content of the hard segment on the activation energy of the degradation process was constructed by response surface methodology. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 764–772, 2007     

Three‐dimensional quasi‐static frictional contact by using second‐order cone linear complementarity problem

A new formulation is presented for the three‐dimensional incremental quasi‐static problems with unilateral frictional contact. Under the assumptions of small rotations and small strains, a second‐order cone linear complementarity problem is formulated, which consists of complementarity conditions defined by bilinear functions and second‐order cone constraints. The equilibrium configurations are obtained by using a combined smoothing and regularization method for the second‐order cone complementarity problem. Copyright © 2005 John Wiley & Sons, Ltd.     

Development of a Highly Sensitive β-Glucan Detection System Using Scanning Single-Molecule Counting Method

To overcome the limitations of the Limulus amebocyte lysate (LAL) assay method for the diagnosis of invasive fungal infection, we applied a reaction system combining recombinant β-glucan binding proteins and a scanning single-molecule counting (SSMC) method. A novel (1→3)-β-D-glucan recognition protein (S-BGRP) and a (1→6)-β-glucanase mutant protein were prepared and tested for the binding of (1→6)-branched (1→3)-β-D-glucan from fungi. S-BGRP and (1→6)-β-glucanase mutant proteins reacted with β-glucan from Candida and Aspergillus spp. Although LAL cross-reacted with plant-derived β-glucans, the new detection system using the SSMC method showed low sensitivity to plant (1→3)-β-D-glucan, which significantly improved the appearance of false positives, a recognized problem with the LAL method. Measurement of β-glucan levels by the SSMC method using recombinant β-glucan-binding proteins may be useful for the diagnosis of fungal infections. This study shows that this detection system could be a new alternative diagnostic method to the LAL method.     

Preliminary report on porcelain in Meissen (Germany) and Arita (Japan)

The Meissen and the Kakiemon-style Arita wares were investigated by PIXE and EPMA. Both porcelain matrices were characterized by high purity ceramics, which are white in tone and translucent due to small amounts of an iron oxide inclusion. From overglazed red, green and gilt parts, enrichment of Fe, Cu, and Au, respectively, was commonly found from the above two wares. There is a resemblance between these two wares in main chemical constituents but there is a difference in impurities or minor elements.     

Mechanistic study on lithium intercalation using a restricted reaction field in LiNi0.5Mn0.5O2

Structure changes of LiNi_0.5Mn_0.5O₂ were detected at the electrode/electrolyte interface of lithium cell using synchrotron X-ray scattering and two-dimensional model electrodes. The electrodes were constructed by an epitaxial film of LiNi_0.5Mn_0.5O₂ synthesized by pulsed laser deposition (PLD) method. The orientation of the film depends on the substrate plane; the 2D layer of LiNi_0.5Mn_0.5O₂ is parallel to the SrTiO₃(1 1 0) substrate ((1 1 0) LiNi_0.5Mn_0.5O₂//(1 1 0) SrTiO₃), while the 2D layer is perpendicular to the SrTiO₃(1 1 1) substrate ((0 0 3) LiNi_0.5Mn_0.5O₂//(1 1 1) SrTiO₃). The in situ X-ray diffraction of LiNi_0.5Mn_0.5O₂(0 0 3) confirmed three-dimensional lithium diffusion through the two-dimensional transition meal layers. The intercalation reaction of LiNi_0.5Mn_0.5O₂ will be discussed.