Orbital view concept applied on photoswitching systems

Diarylethenes are a class of photochromic molecules whose conductance switches with their photoisomerization. We have investigated the conductance of diarylethenes using non-equilibrium Green's function method combined with Hückel method (NEGF–HMO) and density functional theory (NEGF–DFT). In this study we have found that the qualitative predictions based on frontier orbital analysis are consistent with the DFT calculations and can be used for prediction of the electron transport properties of molecular devices.     

Novel strengthening method of closed-cell aluminum foams through surface treatment by resin

Aluminum foams are focused on as a lightweight structural material because of their excellent energy absorbing capacity. However, compressive strength of aluminum foams is much lower than that of dense aluminum. This is due to local buckling of the inhomogeneous cell structure. The authors carried out infiltration of open surface pores with polyester resin because buckling starts at the open surface pores. Compressive tests using commercial aluminum foams show significant increases in compressive strength and absorbed energy. Since the density of resin is not high, the specific compressive strength and specific absorbed energy are also increased.     

High efficiency ester condensation using hydrophobic zeolite membranes

We successfully developed zeolite membranes with hydrophilic character, by choosing appropriate zeolites in terms of hydrophilicity and high acid tolerance. We evaluated thus developed membranes by their pervaporation (PV) performance, dehydration from acidic organic solvent. The zeolite membranes we developed, based on merlinoite (MER), chabazite (CHA) or phillipsite (PHI), are shown to exhibit stable dehydration performance, respectively. We successfully applied the membranes to the selective removal of water in an ester condensation reaction starting from a stoichiometric mixture of a carboxylic acid and an alcohol. The availability of pervaporation-assisted ester condensation reaction was validated by various kinds of combinations of carboxylic acid and alcohols, which implies the general availability of pervaporation-assisted process intensification by zeolite membranes. This paper was presented at the 11th Korea-Japan Symposium on Catatysis held at Seoul, Korea, May 21–24, 2007.     

Solving Schrodinger Equation with Non-Uniform Grids by Scale Transformation Method

Quantum Mechanical Effects(QMEs) in MOSstructures are well-known in the deep-submicron ULSI device characterization[1— 3] .Rigorous study of QMEs in the MOSinversion and accumulation layer requires self-consistent solution to Schrodi...     

Removal of lead compounds from polyvinylchloride in electric wires and cables using cation-exchange resin

Recycling treatment of cable insulation resin generated from electric wires and cables was investigated. Conventional insulation PVC contains a lead component, tribase, as a thermal stabilizer and lead removal is necessary to recycle this PVC as insulation resin. This paper describes a solid surface adsorption method using ion exchange resin to remove the fine lead containing particles from PVC dissolved solution. Low lead concentration in the recovered PVC, complying with the requirements of RoHS, was achieved.     

Amino acid components of lees in salmon fish sauce are tyrosine and phenylalanine

We report that the lees in salmon fish sauce consist of Tyr and Phe. The concentration of free l-Tyr (2.0 mM) was almost same as the saturated concentration (2.4 mM) in water at 20°C. This result shows that lees are formed by Tyr precipitation due to its saturation in the sauce.     

Identification Method of Dynamic Coefficients of Fluid Film Bearings for HDD Spindle Motors

Fluid film bearings are widely used as support elements of rotating shaft for HDD （hard disk drive） spindle motors. Recently, the opportunity for the HDD spindle motors exposed to external vibration has been increasing because the HDDs are used for various information related equipments such as mobile PCs, car navigation systems. Hence, the rotating shaft has a possibility to come in contact with the bearing and it causes wear or seizure to the bearing surface. In order to avoid the problems, it is extremely important to enhance the dynamic characteristics of the fluid film bearings for spindles. However, verification from both theory and experiment of dynamic characteristics such as spring coefficients and damping coefficients is rare and few. In this paper, the bearing vibration characteristics when the HDD spindle is oscillated are investigated theoretically and experimentally. And then the identification method ofoil film coefficients of fluid film bearing spindles is described.     

Processing and performance of solid oxide fuel cell with Gd-doped ceria electrolyte

Fuel Cell performance was measured at 792-1095 K for Ni-GDC (Gd-doped ceria) anode-supported GDC film (60 μm thickness) with a (La_0.8Sr_0.2)(Co_0.8Fe_0.2)O₃ cathode using H₂ fuel containing 3 vol% H₂O. A maximum power density, 436 mW/cm², was obtained at 1095 K. The electrical conductivity of GDC electrolyte in N₂ atmosphere of 10⁻¹⁵-10⁰ Pa oxygen partial pressures (Po₂) at 773-1073 K was independent of Po₂, which indicated the diffusion of oxide ions. The conductivity of GDC in H₂O/H₂ atmosphere increased because of the further formation of electrons due to the dissociation of hydrogen in GDC (H₂ → 2H⁺ + 2e⁻). The hole conductivity was observed at 873 K in Po₂ = 10⁰-10⁴ Pa. The key factors in increasing power density are the increase of open circuit voltage and the suppression of H₂ fuel dissolution in GDC electrolyte. These are controlled by the cathode material and Gd-dopant composition.     

Local plastic deformation in the vicinity of grain boundaries in Fe–3 mass% Si alloy bicrystals and tricrystal

Nanoindentation was used to study incipient plastic deformation in the vicinity of grain boundaries of different character in Fe–3 mass% Si alloy bicrystals and tricrystal. Pop-in events associated with the grain boundaries were observed in the load–displacement curves. From the pop-in hardness values, the critical stresses required to propagate the yield past the grain boundary were estimated to be in the range of approximately µ/400–µ/130 (where µ is the shear modulus) depending on the grain boundary character: the special boundaries usually had higher critical stresses than the general boundaries. A Hall–Petch (H–P) type relationship was found between the hardness and the distance of the indenter to the grain boundary. The H–P slopes obtained were approximately one order of magnitude lower than the macroscopic value of the H–P slope for the Fe–3 mass% Si alloy, and were generally lower for general grain boundaries than for special boundaries.