Osaka Institute of Technology

About: Osaka Institute of Technology is a education organization based out in Osaka, Japan. It is known for research contribution in the topics: Thin film & Laser. The organization has 2457 authors who have published 4247 publications receiving 49872 citations. The organization is also known as: Ōsaka kōgyō daigaku.

Ion Etching of Fused Silica Glasses for High-Power Lasers

Abstract: Subsurface damage incurred during optical polishing, which is known to lower the laser damage thresholds of fused silica surfaces, was studied Ceria in subsurface fissures was completely removed (depths up to one thousand A) using rf-magnetron sputtering without degrading surface roughness The laser-induced damage threshold of the optical coating deposited on an ion-etched surface was improved by a factor of two compared to that on an unprocessed surface

High resistive layers toward ZnO-based enzyme modified field effect transistor

Abstract: One of the key issues for the realization of ZnO-based enzyme modified field effect transistors (FET) is growth of a high resistive layer underneath the active layer of the device structure For that purpose, nitrogen-doped ZnO (ZnO:N) and ZnMgO layers were grown on a-plane sapphire substrates by molecular beam epitaxy (MBE) Although photoluminescence (PL) spectra indicated that nitrogen atom was incorporated as acceptor, ZnO:N layers showed still n-type conductivity probably due to generation of donor-like defects during nitrogen doping On the other hand, ZnMgO layers showed high resistive and flat surface, which will be utilized underlying layers for successive growth of ZnO-based biosensors

Polyion Complex Vesicles with Solvated Phosphobetaine Shells Formed from Oppositely Charged Diblock Copolymers.

Abstract: Diblock copolymers consisting of a hydrophilic poly(2-(methacryloyloxy)ethyl phosphorylcholine) (PMPC) block and either a cationic or anionic block were prepared from (3-(methacrylamido)propyl)trimethylammonium chloride (MAPTAC) or sodium 2-(acrylamido)-2-methylpropanesulfonate (AMPS). Polymers were synthesized via reversible addition-fragmentation chain transfer (RAFT) radical polymerization using a PMPC macro-chain transfer agent. The degree of polymerization for PMPC, cationic PMAPTAC, and anionic PAMPS blocks was 20, 190, and 196, respectively. Combining two solutions of oppositely charged diblock copolymers, PMPC-b-PMAPTAC and PMPC-b-PAMPS, led to the spontaneous formation of polyion complex vesicles (PICsomes). The PICsomes were characterized using 1H NMR, static abd dynamic light scattering, transmittance electron microscopy (TEM), and atomic force microscopy. Maximum hydrodynamic radius (Rh) for the PICsome was observed at a neutral charge balance of the cationic and anionic diblock copolymers. The Rh value and aggregation number (Nagg) of PICsomes in 0.1 M NaCl was 78.0 nm and 7770, respectively. A spherical hollow vesicle structure was observed in TEM images. The hydrodynamic size of the PICsomes increased with concentration of the diblock copolymer solutions before mixing. Thus, the size of the PICsomes can be controlled by selecting an appropriate preparation method.

Thermal Stress Intensity Factors for Two Coplanar Cracks in a Piezoelectric Strip

Abstract: This work is concerned with the thermoelectromechanical fracture behavior of two coplanar cracks in a piezoelectric material strip under a uniform heat flow far away from the crack region. The crack faces are supposed to be insulated thermally and electrically. Fourier transforms are used to reduced the mixed boundary value problems to singular integral equations. Numerical calculations are carried out, and detailed results are presented to illustrate the influence of the geometric parameters on the thermal stress intensity factors.

Growth and Characterization of InN Heteroepitaxial Layers Grown on Si Substrates by ECR-Assisted MBE

Abstract: For the first time, we observed strong band-edge photoluminescence at 1.814 eV, and two stronger emissions at 1.880 and 2.081 eV at 8.5 K from the respective 880 nm thick InN heteroepitaxial layers (heteroepilayers) with 10 nm thick InN buffer layers grown on Si(001) and Si(111) substrates by electron cyclotron resonance-assisted molecular beam epitaxy. The former was probably assigned as donor-to-acceptor pair (DAP(a-InN)) emission from wurtzite-InN (a-InN) crystal grains, the latter were assigned as donor bound exciton (D°X(a-InN)) emission, and D 0 X(β-InN) or DAP(β-InN) emission from zincblende-InN (β-InN) crystal grains, respectively. Substrate annealing before growth and the introduction of a buffer layer had strong influences on the crystal structure and crystalline quality of the initial InN heteroepilayers.