Tilt angle dependence of output power in an 80 kWp hybrid PV system installed at Shiga in Japan

One-year field experience of an 80 kW PV system on a rooftop of the ROHM Memorial VLSI Research Center at the Ritsumeikan University is reported. All kinds of live technology available materials, c-Si, poly Si and a-Si solar cells are installed on the three tilt angles of 26.5° south, horizontal and north 26.5°. Systematic PV performances have been measured from the beginning of June 2000 to the end of May 2001. Measurements were made mainly on DC output power from four kinds of PV arrays; c-Si south side, a-Si of horizontal and poly Si, a-Si north side. It has been shown from analyses of monthly data on each material that almost 70% of with that in the south side in the annual average. In summer a-Si module yields the maximum output power normalized to 1 kWp. On the contrary c-Si module shows larger output in winter. Some other unique results are demonstrated and discussed.     

Study on the Effects of Flow in the Volute Casing on the Performance of a Sirocco Fan

The flow at the exit from the runner blade of a centrifugal fan with forward curved blades (a sirocco fan) sometimes separates and becomes unstable. We have conducted many researches on the impeller shape of a sirocco fan, proper inlet and exit blade angles were considered to obtain optimum performance. In this paper, the casing shape were decided by changing the circumferential angle, magnifying angle and the width, 21 sorts of casings were used. Performance tests, inner flow velocity and pressure distributions were measured as well. Computational fluid dynamic calculations were also made and compared with the experimental results. Finally, the most suitable casing shape for best performance is considered.     

Structural, electrical and bending properties of transparent conductive Ga-doped ZnO films on polymer substrates

We investigated the characteristics of highly transparent conductive Ga-doped ZnO (GZO) polycrystalline films of 100 nm thickness deposited on glass and polymer substrates. GZO films were deposited by ion plating with dc-arc discharge. We developed multiple-deposition method to obtain various deposition process temperatures lower than 100 °C. Cross-sectional SEM images show that all the GZO films have columnar structure. Analysis of data obtained by XRD measurements shows that all the GZO films with wurtzite structure exhibit highly (002) orientation perpendicular to the substrate. The resistivity of the GZO films deposited on polyester and glass substrates were 5.0 × 10^-4 Ω · cm. The mechanical bending properties of the GZO films were investigated by comparing the sheet resistance determined before and after a bending test with various bending diameters. For the bending diameter of more than 30 mm, all the GZO films exhibited excellent bending properties with no change in sheet resistance. For the bending diameter of less than 20 mm, we found the sheet resistance affected by the bending. We demonstrated that our multiple-deposition method to achieve different controllable polyester substrate temperatures is highly suitable for improving the bending properties of GZO films.     

Radiation induced synthesis of Au-Pd nanoparticles of random alloy structure supported on carbon particles using the high energy electron beam

Au-Pd bimetallic nanoparticles supported on carbon particles were synthesized by reduction of precursor ions in an aqueous solution irradiated with a high energy electron beam. The composition of the samples was analyzed by the inductively coupled plasma atomic emission spectrometry (ICP-AES), and the morphology of the samples was observed by the transmission electron microscope (TEM). TEM micrographs indicated that Au-Pd particles of ca. 5-nm were well dispersed on the surface of carbon particles of ca. 30-nm without any serious agglomeration. Addition of citric acid to the initial solution and high pH were found to be effective for formation of random alloy structure in the resultant bimetallic nanoparticles. The change in the bimetallic structure from core-shell to random alloy was identified by techniques of the X-ray diffraction (XRD) and the extended X-ray absorption fine structure (EXAFS).     

Synthesis of l-theanine using enzyme/mesoporous silica conjugates under high pH conditions

We present a new enzymatic process for synthesis of l-theanine using glutaminase combined with immobilization technique on a mesoporous silica (MPS). The MPS was firstly attempted to modify with zirconia in order to enhance the durability against the reaction under high pH conditions. The glutaminase on the MPS successfully catalyzed the reaction for the synthesis of l-theanine. The glutaminase/MPS conjugate was subsequently recovered and employed for the reaction again. The conjugate showed the corresponding activity to the first synthesis. This indicates that the conjugate functions as a catalyst for synthesis of l-theanine, having the operational stability sufficient for reuse.     

Formulation study of topically applied O/W lotion containing vitamin D3 derivative, focusing on skin permeability of the drug

Permeation of 22-oxacalcitriol-1α, 25-dihydroxyvitamin D(3) (OCT) through excited hairless mouse skin was determined after application of OCT as solutions and O/W lotions consisted of different polarities of solvents: medium-chain fatty acid triglyceride (MCT), myristate isopropyl (IPM), 1,3-butylene glycol (1,3-BG), and propylene glycol (PG). OCT concentration in skin was also followed after applying these formulations. A two-layer diffusion model was composed to analyze dermatopharmacokinetic profiles of OCT for each vehicle. In the OCT solutions, skin permeation profile of OCT differed depending on solvent polarity. The O/W lotion with a high MCT content led to a low amount of OCT in skin. On the other hand, the O/W lotion with a high 1,3-BG content led to a high amount of OCT in skin. This dermatopharmacokinetic analysis indicated that addition of MCT to the formulation decreases the skin/vehicle partition coefficient of OCT and increases the diffusion coefficient of OCT in skin. However, the opposite effects on these two parameters were found in the case of 1,3-BG. Thus, skin permeability of OCT differed depending on the solvents used in the formulation. These results indicate that skin permeability of OCT is influenced by the physicochemical properties (i.e. polarity) of OCT, solvent, and skin. Our findings on the solvent effects of the skin permeability of OCT are thus useful for designing topical drug formulation, especially in aiming for bioequivalent dosage formulas.     

Precipitation phenomena in and electrical resistivity of high-temperature treated langatate (La3Ta0.5Ga5.5O14)

La(3)Ta(0.5)Ga(5.5)O(14) (LTG) single crystals, which have no phase transition up to the melting point, were heat-treated in air at temperatures from 1000°C to 1450°C for 10 h. LaTaO(4) (LT) and LaGaO(3) (LG), which coexist with LTG in the three-phase region on the Ga-poor side, precipitated on the surface of the crystal for heat treatments above 1300°C because of Ga evaporation during the heat treatment. The Ga-poor state near the surface of the 1450°C heat-treated specimen was confirmed by electron probe micro-analysis measurements. The electrical resistivity of LTG single crystals decreased by heat treatment in the range of 1000°C to 1200°C for 10 h in air, where no precipitation was observed, whereas the resistivity increased with heat treatment over 1400°C for 10 h in air. The electrical resistivity of the Ga-poor surface region was higher than that of the interior.     

Novel screening system for protein-protein interactions by bimolecular fluorescence complementation in Saccharomyces cerevisiae

For high-throughput screening of protein-protein interactions, we have developed a novel yeast screening system using Bimolecular fluorescence complementation (BiFC). Two yeast plasmids, in which genes of heterodimerized peptides LZA and LZB were each fused with those of non-fluorescent half fragments of Kusabira-Green mutant (mKG2), were transformed into a- and α-type yeast, respectively. Mating of them gave a library, which was screened by following green fluorescence resulted from LZA-LZB interaction. The method showed potential ability to detect the positive clones from a model library, in which green-fluorescent and non-fluorescent yeast was mixed in a ratio of 1:675.