Preparation of composite particles made from solid powders and wasted plastics by semichemical recycle method

Composite particles composed of solid powders and polymer were prepared by semichemical recycle of wasted plastics. Waste expanded polystyrene was used as raw materials of polymer matrix of composite particles. Both magnetite and silicon carbide powders were used as solid powders to give thermal and electric conductivity and magnetization, respectively. In the experiment, the oil‐phase dissolving expanded polystyrene was dispersed in fine droplets into the continuous water phase. Two kinds of powders were added at the same time or separately in the O/W dispersion. Composite particles were found to have the structure that polymer particle was covered with two kinds of solid powders. The mean diameter of composite particles and the content of each solid powder were strongly affected by the addition time when silicon carbide powder was added into the dispersion. Furthermore, it was found that the gradient adhesion layer due to two solid powders was able to be formed on the surface of polymer particle. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 483–488, 2003     

Silicon planar-apertured probe array for high-density near-field optical storage

We propose a novel, to our knowledge, silicon planar-apertured probe array as an optical head for high-density near-field optical storage. In comparison with a conventional fiber probe employed for near-field optical storage the apertured probe array has a higher readout data-transmission rate and better mechanical durability. A probe array with an aperture size of 100 nm was fabricated by use of photolithography and wet etching of a silicon wafer. Subwavelength-readout capability was demonstrated by use of one aperture of the probe array. Furthermore, we achieved a 16 times increase in the light-transmission efficiency of the probe array by installing glass-sphere microlenses on each aperture. The increase was confirmed by measurement of the near-field optical intensity.     

Coagulation factor X-binding protein from Deinagkistrodon acutus venom is a Gla domain-binding protein

Factor IX/factor X-binding protein (IX/X-bp) is an anticoagulant isolated from the venom of Trimeresurus flavoviridis (habu snake) and binds predominantly to factor IX. In this study, we isolated IX/X-bp-like proteins from the venom of Deinagkistrodon acutus (hundred pace snake) with binding characteristics different from those of IX/X-bp. The complete amino acid sequence and binding characteristics of the main anticoagulant protein, named X-bp, were investigated. The concentrations of X-bp at half-maximal binding to solid-phase factors X and IX were 0.4 and 3 nM, respectively. The binding of X-bp to solid-phase factor X was inhibited by 50% by 6- and 9-fold excess concentrations of factor X and Gla domain (GD) peptide 1-44, respectively, but was not influenced by GD peptide 1-41 and Gla domainless factor X. X-bp bound two Ca2+ ions per molecule with Kd values of 16 +/- 0.7 (mean +/- SE, n = 6) and 103 +/- 10 microM. X-bp was a heterodimer of C-type lectin-like subunits. The 16 kDa chain (A chain) consisted of 129 amino acid residues and was 68% identical to the sequence of the A chain of IX/X-bp. The 15 kDa chain (B chain) consisted of 123 amino acid residues and was 87% identical to IX/X-bp. Three-dimensional model construction from the known fold of IX/X-bp showed that amino acid residues different from those of IX/X-bp are mostly on the molecular surface. Some of these are concentrated on a part of the concave surface which is considered to be the coagulation factor-binding site, presumably acting as a discriminator for ligand binding. These results indicated that X-bp isolated from D. acutus venom was a GD-binding protein, and the C-terminal region of GD peptide was critical for folding of the peptide.     

Improvement of diamond X-ray mask membrane: Optical transmittance, surface roughness and irradiation durability

A viable method for the improvement of the polycrystalline diamond X-ray mask membrane is proposed. The use of an ionized cluster beam yields the smoothest surface. Sol-gel planarization film coating with indium tin oxide is the most effective method for obtaining high optical transmittance without sacrificing high synchrotron irradiation durability.     

Preparation of single crystals of MoB2 by the aluminium-flux technique and some of their properties

Crystal growth of MoB₂ (R-3m;a _hex. = 0.30136(6) nm,c _hex. = 2.0961 (4) nm) from high-temperature aluminium solutions (1000 to 1500°C) has been investigated, and the optimum conditions for obtaining single crystals of this compound were examined. Starting with about 33 to 53 g of a mixture of molybdenum, boron and aluminium, in which the atomic ratio is 1 : 2.5 : 53.3 to 88.9, MoB₂ single crystals of about 1.5 mm in size were grown without being accompanied by any other crystal phases. The stoichiometry and the crystal structure were corroborated by chemical analysis and single-crystal X-ray diffractometry. The Vickers microhardness measured in the (001) plane is in the range 2170 to 2470 kg mm^–2. The oxidation of the crystal in air is examined by thermogravimetric and differential thermal analyses up to 1200°C.     

Study on deflection of X-ray mask membrane in stepper motion

Deflection of the X-ray mask membrane caused by stepper motion, i.e., changing the mask-to-wafer gap and stepping the wafer parallel to the mask, was evaluated. The effects of film tension, mask configuration and velocity of wafer stage movement on the membrane behavior were examined. The deflection caused by parallel stepping in the proximity gap is very sensitive to the parallelism between the mask and the wafer. The membrane deflection of less than 2 μm and the relaxation time of less than 0.2 sec were observed under the condition of a 20 μm gap and within 0.2 μm/20 mm of mask inclination. It was confirmed that the relaxation time is inversely proportional to the tension of the film. It was also found that the mesa-type mask is capable of reducing the relaxation time to about 30 % less than that of a conventional mask, and that the membrane deflection of the mesa-type mask becomes almost half that of the conventional one. The mesa-type mask is thought to effectively reduce the membrane deflection and the relaxation time.