Acoustic phonon modulation and electron�Cphonon interaction in?semiconductor slabs and nanowires

The acoustic phonon modulation (confinement) in semiconductor nanostructures and their interaction with electrons are reviewed. Special emphasis will be placed on free-standing and layered slabs, as well as nanowires. Analysis includes acoustic phonon dispersion relations, displacement wave functions, amplitudes, form factor, electron-phonon scattering rate, and electron mobility.     

A study of manipulator with passive revolute joint

In this article, equations of motion of a manipulator, whose mechanism has a passive revolute joint, are derived in consideration of the characteristics of driving source. Considering the fi nal condition of displacement and velocity of the passive joint, trajectories of velocity for energy saving are calculated by iterative dynamic programming. And the dynamic characteristics of manipulator control based on the trajectory for energy saving are analyzed theoretically and investigated experimentally. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Suppression of by-product generation in the treatment of aromatic perfumery substances using a surface discharge

Treatment of perfumery materials such as aromatic hydrocarbons was attempted using atmospheric surface discharge and UV light irradiation. The maximum decomposition rate of phenyl ethyl benzene with a concentration of 8% using the discharge with UV light is 96%, that is 12% higher than that without UV light. Combination of surface discharge and UV light enhances the decomposition rate and energy efficiency, and enables to suppress the generation of by-products such as benzene.     

Effect of Time-Dependent Humidity Profiles from Air to Superheated Steam on Drying of a Wetted Starch Sphere

The effects of air humidity when drying with superheated steam (SHS) were examined considering displacement by SHS. A wetted raw starch sphere (ball) was used as the model material. It was found that the humidity profile strongly affects the mass change and properties of the products. The material became porous when it was dried with pure SHS from start to finish, which differs both from products dried with high-humidity air alone, and from products dried with air followed by SHS within a few minutes. A prediction method for adiabatic saturation temperature over a wide range of humidity is also proposed.     

Photochemical reactions of high polymers. XIII. Photografting of methyl methacrylate onto the polymers bearing thiosulfate groups

Polymers bearing pendent thiosulfate groups, that is, sodium poly(vinyl benzyl thiosulfate) (PVBB) and the sodium salt of poly(vinyl hydrothiosulfatoacetate)(PV AcB), were prepared. The photograft polymerization of methyl methacrylate onto these polymers was carried out. The relationships between irradiation time and conversion, degree of grafting, and grafting efficiency were investigated in the photograft polymerization. It was ascertained that the pendent thiosulfate groups acted as effective initiators for the graft polymerization. From the number of endgroups in the homopolymer formed along with the graft polymer, the mechanism of the graft polymerization was discussed and it was verified that the graft polymerization was initiated by the thiyl radical formed by scission of the sulfur–sulfur bond of the pendent thiosulfate group. An unusually high degree of grafting and extremely rapid polymerization rate observed in the graft polymerization suggested the dual functions of thiosulfate-bearing polymer as initiator and emulsifier. It was found that addition of FeCl₂ to this polymerization system increased the rate of polymerization and the degree of grafting but decreased the grafting efficiency. The effect of FeCl₂ was interpreted by assumption of a photo-redox reaction between thiosulfate group and Fe²⁺.     

Use of highly compressible Ceolus™ microcrystalline cellulose for improved dosage form properties containing a hydrophilic solid dispersion

The development of amorphous solid dispersions containing poorly soluble drug substances has been well-documented; however, little attention has been given to the development of the finished dosage form. The objective of this study was to investigate the use of Ceolus(?) microcrystalline cellulose, a highly compressible excipient, for the production of rapidly disintegrating tablets containing a hydrophilic solid dispersion of a poorly soluble drug, indomethacin. Solid dispersions of indomethacin and Kollidon(?) VA64 were prepared by hot melt extrusion and characterized for amorphous nature. Milled dispersion particles at 500 mg/g drug loading were shown to be amorphous by differential scanning calorimetry and provided rapid dissolution in sink conditions. Physical characterization of the milled extrudate showed that the particle size of the intermediate was comparable with Ceolus(?) PH-102 and larger than the high compressibility grades of microcrystalline cellulose selected for the trial (Ceolus(?) KG-802, Ceolus(?) UF-711). Preliminary tableting trials showed that dissolution performance was significantly reduced for formulations at dispersion loadings in excess of 50%. Using a mixture design of experiments (DOE), the levels of PH-102, KG-802, UF-711, and PH-301 were optimized. Trials revealed a synergistic relationship between conventional grades (PH-102 and PH-301) and highly compressible grades (KG-802 and UF-711) leading to improved compression characteristics and more rapid dissolution rates. The formulation and resulting compressibility were also shown to have an impact on in vitro supersaturation indicating tablet formulation could impact oral bioavailability. Through the use of highly compressible microcrystalline cellulose grades such as Ceolus(?) KG-802 and UF-711, it may be possible to maximize the bioavailability benefit of amorphous solid dispersions administered as tablet dosage forms.     

Analysis of a manipulator in relation to collision between a link and an object

In this article, equations of motion of a manipulator are derived after consideration of the characteristics of the driving source. By considering a collision between a link and an object, and considering the active motion to absorb the kinetic energy of the object, the trajectories for saving energy are calculated by the iterative dynamic programming (IDP) method. The dynamic characteristics of manipulator control based on the trajectory for saving energy are also analyzed theoretically and investigated experimentally.     

Bioproduction of Chiral Epoxyalkanes using Styrene Monooxygenase from Rhodococcus sp. ST‐10 (RhSMO)

We describe the enantioselective epoxidation of straight‐chain aliphatic alkenes using a biocatalytic system containing styrene monooxygenase from Rhodococcus sp. ST‐10 and alcohol dehydrogenase from Leifsonia sp. S749. The biocatalyzed enantiomeric epoxidation of 1‐hexene to (S)‐1,2‐epoxyhexane (>44.6 mM) using 2‐propanol as the hydrogen donor was achieved under optimized conditions. The biocatalyst had broad substrate specificity for various aliphatic alkenes, including terminal, internal, unfunctionalized, and di‐ and tri‐substituted alkenes. Here, we demonstrate that this biocatalytic system is suitable for the efficient production of enantioenriched (S)‐epoxyalkanes.