Compact electrostatic levitator for diffraction measurements with a two axis diffractometer and a laboratory x-ray source

A compact electrostatic levitator was developed for the structural analysis of high-temperature liquids by x-ray diffraction methods. The size of the levitator was 200 mm in diameter and 200 mm in height and can be set up on a two axis diffractometer with a laboratory x-ray source, which is very convenient in performing structural measurements of high-temperature liquids. In particular, since the laboratory x-ray source allows a great amount of user time, preliminary or challenging experiments can be performed with trial and error, which prepares and complements synchrotron x-ray experiments. The present small apparatus also provides the advantage of portability and facility of setting. To demonstrate the capability of this electrostatic levitator, the static structure factors of alumina and silicon samples in their liquid phases were successfully measured.     

Highly reliable oxide‐semiconductor TFT for AMOLED displays

Abstract— The stability and reliability of oxide‐semiconductor TFTs were investigated. The contact material to the oxide semiconductor affected the thermal stability of the TFT, and a molybdenum‐contact source/drain showed good stability. And the passivating film and TFT structure affected the stability against bias stress and humidity stress, and dc‐sputtered Al²O³ passivation and fully covered channel structure with an etching stopper or source/drain showed good reliability. Moreover, high photo‐stability was confirmed by the bias‐enhanced photo‐irradiation stress test. An 11.7‐in.‐diagonal qHD AMOLED display was demonstrated to provide an applicable solution for a large‐sized OLED and an ultra‐high‐definition LCD‐TV mass production.     

Biocompatibility of a-C:H film coating for synthetic vascular graft

Amorphous hydrogenated carbon (a-C:H) films have many excellent properties such as biocompatibility, anti-corrosion, and chemical stability. Therefore, there are many reports on application of a-C:H film as surface modification technique for biomaterials. However, it is difficult to deposit a-C:H film on complex structures such as artificial heart blood pump and synthetic vascular grafts. In our previous work, we have developed an electrode which is adapted to such irregular structures for plasma CVD technique.In this study, a-C:H film was deposited on a synthetic vascular graft inner-wall by r.f. plasma CVD technique with cylindrical electrode. The purpose of such coating is improvement of biocompatibility of the vascular graft. The biocompatibility of the a-C:H film was evaluated by cytocompatibility and plasma protein adhesion. For the a-C:H film deposition, cytocompatibility and protein adsorbent of the vascular grafts were improved for biological response under cell culture with mouth fibroblasts and plasma proteins (albumin, fibrinogen, and globulin), respectively. This study indicates that the a-C:H films coatings is expected to surface modification for medical appliances.     

The use of indoline dyes in a zinc oxide dye-sensitized solar cell

The effects of the position and the type of carboxyl anchor group in double rhodanine-type indoline dyes on the performance of a zinc oxide dye-sensitized solar cell were examined. The optimum position for the carboxymethyl group was on the inner rhodanine moiety; a carboxymethyl group gave optimum results among carboxymethyl, -ethyl, and -propyl derivatives.     

To Journal of Phase Equilibria and Diffusion Phase Relationship of the BaO-ZrO<Subscript>2</Subscript>-YO<Subscript>1.5</Subscript> System at 1500 and 1600 °C

Phase relationship of a BaO-ZrO₂-YO_1.5 system at 1500 and 1600 °C was examined in order to determine whether a phase separation at the composition of 15% yttrium-doped barium zirconate exists. According to a pseudoternary phase diagram of the BaO-ZrO₂-YO_1.5 system established by this work, the solubility of yttria into cubic barium zirconate at 1600 °C is 0.25 in a mole fraction of yttria (X_\textYO1.5 ) (X_{{{\text{YO}}_{1.5} }} ) . Thus, we confirmed that there is no phase separation at the composition of 15% yttrium-doped barium zirconate at 1600 °C. On the other hand, at 1500 °C, there might be a phase separation at the composition of 15% yttrium-doped barium zirconate into yttrium-doped barium zirconate where quite small amount of yttrium is doped and a new phase whose composition is close to reported BZ(II) phase.     

Numerical Analysis of the Boundary Scattering Effect on Transport Properties in Bi-Sb Nanowires

In this study, we have numerically analyzed the transport properties of Bi-Sb nanowires, taking into account wire boundary scattering. Wire boundary scattering slightly decreased the Seebeck coefficient of Bi-Sb nanowires. This effect is due to the observation that boundary scattering and the mobility ratio of L-point electrons to T-point holes in the nanowires are smaller than those in bulk Bi-Sb because the wire boundary scattering suppresses the mobilities of L-point electrons and heavy holes. The largest Seebeck coefficient for all wire diameters was obtained when the Sb concentration was 5 at.%. The effective mass approached zero near 5 at.% Sb, and the small effective mass led to a large subband shift in each band. Thus, a small effective mass enhances the quantum effect at a fixed wire diameter, even if wire boundary scattering is taken into account.     

Development of High Count Rate TES Microcalorimeters

To realize new TES imaging for high energy X-ray or gamma-ray spectrometer with a large pixel array and high count rate, we will try to develop a new radiation absorber self-adjusting the operating temperature and adopting an original reading out method of large pixel array using parallel biasing scheme. Our first prototype TES pixel using Au/Ti/Au tri-layer which consists of the small heat sensors and the radiation absorption area, and these are biased in serial. In this device, the current pulse with the decay time constant of less than 20 microseconds of incident X-rays from ⁵⁵Fe source were observed.      

Nanopillar array chip integrated with on-line stacking for fast DNA separation with high sensitivity and high resolution

Recent developments of nanofabrication techniques have created a trend switching from randomly ordered polymeric matrices, such as gel, to highly ordered sieving nanostructures in the separation of biomolecules. These nanostructures have enormous potential for fast separation of biomolecules, while nanostructure-based separation techniques suffer from critical scaling problems; they are efficient in handling less than nanoliter amounts of sample fluids, but most biomolecule samples are available in a liquid volume that is over several microliter, leading to a reduction in sensitivity and resolution. In this study, we developed a nanopillar array chip integrated with an easy and rapid on-line stacking method and achieved fast DNA separation with high sensitivity and high resolution. The developed on-line stacking method is based on the balance of two forces driven by electric fields: electroosmotic flow (EOF) and electrophoresis. The EOF mobility from the microchannel to the nanopillar-channel is drastically decreased, while, on the other hand, electrophoresis has constant mobilities in the whole length of the channels. The on-line stacking was realized at the well-balanced position of the two forces, and the on-line stacking using the nanopillar array chip can also be achieved within 10 s by just applying electric voltages without any other special reagents and materials. After applying on-line stacking using the nanopillar array chip, the relative fluorescence intensity increased 1,000-fold, and the resolution was twice as good as that without on-line stacking.     

New monitoring approach for metabolic dynamics in microbial ecosystems using stable-isotope-labeling technologies

We have developed a new approach for monitoring the metabolic dynamics in microbial ecosystems using a combination of DNA fingerprinting and metabolome analysis based on stable-isotope-labeling technologies. Stable-isotope probing of DNA (DNA-SIP) has been used previously for the evaluation of cross-feeding in microbial communities. For the development and validation of our monitoring approach, fecal microbiota were analyzed with stable-isotope-labeled glucose used as the sole carbon source. In order to link the metabolic information and the microbial variability, we performed metabolic–microbial correlation analysis based on nuclear magnetic resonance (NMR) profiles and denaturing gradient gel electrophoresis (DGGE) fingerprints, which successfully identified the glucose-utilizing bacteria and their related extracellular metabolites. Moreover, our approach revealed information regarding the carbon flux, in that the “first” wave of extracellular metabolites secreted by the glucose-utilizing bacteria were incorporated into the “secondary” group of substrate-utilizing bacteria, and that this “secondary” group further produced their own secondary metabolized substrates. Thus, this approach is a powerful tool for monitoring the metabolic dynamics in microbial ecosystems and allows for the tracking of the carbon flux within a microbial community.     

A study of electrical characteristic changes in MOSFET by electron beam irradiation

Mechanisms for electrical characteristic changes in MOSFET caused by electron beam irradiation were studied using a SEM-based nano-probing system. A shift in V_th occurs when a hole is trapped in a defect (oxygen vacancy) in the gate dielectric layer. Holes are generated when the plasmon is excited by electron beam irradiation. Further, an electric field is created by the positive charge-up resulting from electron beam irradiation of the ILD, causing an increase in leakage between gate and drain leading to an increase in I_off. This study shows that advanced devices can be measured using a SEM-based nano-probing system without inducing electrical characteristic changes by optimizing the measurement conditions such as acceleration voltage, electron beam current, image magnification, ILD thickness, and electron beam irradiation time.