Large area ZnO films optimized for graded band-gap Cu(InGa)Se2-based thin-film mini-modules

In this study, two deposition methods (i.e. MOCVD and sputtering methods) to prepare n-type ZnO window layers for CIGS-based thin-film solar cells are discussed. In order to make ZnO : Al transparent conductive oxide (TCO) films prepared by DC magnetron sputtering comparable to ZnO : B TCO prepared by MOCVD, a new ZnO sputtering process is proposed by introducing a multilayer structure. Using these films, CIGS thin-film solar cells with efficiencies of greater than 14% have been fabricated with an active area of 3.2 cm². This structure was adapted to fabricate CIGS thin-film mini-modules with efficiencies around 11% having aperture area of 50 cm².     

Dynamic driving/braking force distribution in electric vehicles with independently driven four wheels

A novel algorithm for the dynamic driving/braking force distribution is proposed for electric vehicles (EV) with four in‐wheel motors. In such EVs, the vehicle lateral motion can be controlled by a yaw moment, generated by the torque difference between wheels. This method is known as DYC (Direct Yaw moment Control) in ordinary engine vehicle engineering; however, the torque difference can be generated more directly with in‐wheel motors. One problem of DYC is its instability on slippery roads, such as wet or snowy asphalt. To achieve high stability, the loads of wheels are preferably equal. The load on each wheel can be evaluated as the square root of the sum of squares of driving/braking force and side force. Therefore, the driving/braking forces, or motor torques, should be distributed depending on the side forces of the wheels, to minimize the load imbalance between wheels. The proposed algorithm can solve this optimization problem approximately with little calculation cost, and thus this method can be applied for real‐time calculation within a control period. Approximate solutions obtained with the proposed method are evaluated by comparison with numerical solutions that require much calculation time. The difference between these solutions is shown to be negligible, indicating the effectiveness of the proposed method. © 2001 Scripta Technica, Electr Eng Jpn, 138(1): 79–89, 2002     

Measuring method of three thermophysical parameters of solids by a thermal probe with instantaneous point contact: Discussion about applicability and measuring conditions

An instrument for the measuring method reported in the previous paper is a handy tester for three thermophysical parameters of solids in situ. Discussions about measurement errors caused by not strictly satisfying the measuring conditions, such as size and shape of the testing body, and about optimum initial temperature difference between thermal probe and testing body have been done. As a result of the experiment varying the shape of a probe end, it is shown that the radius of the contacting surface on a testing body has no influence on measuring thermophysical parameters. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(3): 202–211, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10085     

Stability of hydrogen incorporated in ZnO nanowires by plasma treatment

The stability of hydrogen in ZnO is studied using hydrogenated nanowires by plasma treatment. Enhanced near band edge UV emission and reduced defect level green emission is observed after hydrogen plasma treatment. Through thermal stability tests, this effect is found to be stable at room temperature and nearly stable up to ~500 K, but begins to deteriorate at higher temperature. The study of the irradiation stability of the hydrogen in ZnO nanowires shows that the hydrogen is stable under an electron beam with an accelerating voltage lower than 5 kV, but is not stable under 10 kV or under an intensive laser beam. The results could benefit the further understanding of the role of hydrogen in ZnO and light-emitting devices based on hydrogenated ZnO.     

Survey of pesticide residues in imported frozen vegetables and fruits (1989.4~2008.3)

A survey of pesticide residues in 595 imported frozen products on the Tokyo market from April 1989 to March 2008 was carried out. Forty three kinds of pesticides, including organophosphorus, organochlorine, carbamate, pyrethroid and others, were detected between levels of trace (below 0.01 ppm) and 4.6 ppm from 162 samples. Chlorpyrifos, cypermethrin and omethoate were frequently detected in green vegetables (komatsuna leaf and spinach), cypermethrin and methamidophos were detected in pods and seeds (green soybean and string pea), chlorpropham (CIPC) was detected in potato, and captan and carbaryl were detected in berries (blueberry, raspberry and strawberry). The hydrophilic pesticide methamidophos was detected in flesh of lychee. Residue levels of these pesticides were calculated as between less than 0.5% and 30% of their ADI values according to the daily intake of frozen products. Therefore, these frozen products should be safe when they were eaten in customary amounts.     

Minimal area for surface reconstruction from cross sections

Surface reconstruction from cross-sectional data is important in a variety of applications. It is usually possible to generate a surface in many ways, but only reasonable ones are acceptable. A surface of minimal area has been considered as one of the most natural optimal criteria for the original tiling method of surface reconstruction from cross sections. In the paper, we consider minimal surfaces for continuous generalization of the tiling approach and in the general situation of reconstruction from cross sections. We show that in these cases the minimal area criterion leads to defective surfaces and is thus unacceptable. Published online: 23 July 2002 Correspondence to: D. Berzin     

Azimuthal wave number control of oscillatory thermocapillary convection in a liquid bridge

Thermocapillary convection in a half‐zone liquid bridge of high Prandtl number fluid is widely known to exhibit a three‐dimensional oscillatory flow after the onset of oscillation. The oscillatory flow presents ‘standing’ and ‘traveling’ flows depending upon the temperature difference between the top and bottom rods. In the oscillatory state, the flow shows a modal structure with an azimuthal wave number that depends on the aspect ratio of the liquid bridge and the intensity of the thermocapillarity expressed by the Marangoni number. The present study attempted to control the azimuthal wave number by heating the free surface locally with a prescribed frequency and intensity. The flow in the liquid bridge exhibited different modal structures depending on the heating conditions and a relationship between the frequency and the modal structure was obtained. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(7): 460–469, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20086     

Accumulation of triosephosphate isomerase, with sequence homology to Beta amyloid peptides, in vessel walls of the newborn piglet hippocampus

We investigated whether beta-amyloid (Abeta)-like immunoreactivity was seen in the brains of newborn piglets. The immunoreactivity for Abeta(1-42) and Abeta(1-40) proteins, but not Abeta precursor protein, was present in CD68-positive perivascular cells of the hippocampus and in parts of the meninges. It was colocalized with immunoreactivity for receptor for advanced glycation end product and tumor necrosis factor-alpha. The protein with a molecular mass of 27 kDa, which was recognized by the Abeta antibodies, was identified as triosephosphate isomerase (TPI) with sequence homology to Abeta peptides by N-terminal amino acid sequencing, mass fingerprint analysis using matrix-associated laser desorption/ionization mass spectrometry, and Western blotting. Western blotting assay also revealed that detectable expression of Abeta proteins were not seen in the piglet brains. These findings indicate that TPI with sequence homology to Abeta peptides accumulates in perivascular cells of the microglia/macrophage lineage located around arterial vessels of the newborn piglet hippocampus.