Characteristics of a-Si solar cells prepared by the super chamber at a high substrate temperature

A new approach to high-performance a-Si solar cells was studied. a-Si films prepared at a high substrate temperature (> 250°C) have a higher absorption coefficient and a low Si H₂ bond density. the effect of deposition temperature on the open-circuit voltage (V_oc) has been investigated systematically for glass/SnO2 Ipin/metal and glass/metal/nip/indium tin oxide (ITO) structure a-Si solar cells. The V_oc is found to depend strongly on the thermal history of the p/i interface. A short-circuit current of 19.5 mA/cm⁻⁻² was achieved for an a-Si solar cell using an a-Si i-layer with a thickness of 4000 Å, which was prepared at a substrate temperature of 270°C.     

Effect of blending on liquefaction of coals

After solvent extraction of Taiheiyo, Miike and Balmer coals using wash oil under nitrogen atmosphere at 370 °C for 30 min, the extraction yield is always within the additivity law. Further studies used Yallourn, Soyakoishi, Taiheiyo, Horonai, Miike, Shin Yubari, Balmer coals and their blends which were hydrogenated in tetralin, wash oil or creosote oil, with or without catalyst, at 400–450 °C under 10 or 3 MPa of initial hydrogen pressure. When hydrogen is available, the additivity law exists for blended coals, but when the hydrogen supply is deficient, the experimental conversion of blended coals is always lower than calculated conversions. This may be due to the faster consumption of the hydrogen by more reactive coals and thus the less reactive coals were unable to react with hydrogen.     

Synchronal measurement of flow structure and heat transfer of impingement jet

This paper will present the characteristics of flow behavior and thermal field of both free and
impingement jet issued from a circular orifice nozzle at Re=8900.The flow behavior of a single round
jet and impingement jet was observed by smoke flow visualization recorded by a high speed camera
using 5000 frame per second.Heat transfer coefficient on the impingement surface was measured by
means of infrared camera （TVS-8500,Avio） with a two-dimensional array of Indeum-Antimony （In Sb）
sensors varying in the separation distance between the nozzle and the target plate.The heat transfer
coefficient changes in time and spatial.Therefore,the root mean square distribution of the heat
transfer was obtained from the data.As a result,it was confirmed that the longitudinal vortex was
observed outside of the ring vortex,and then the longitudinal vortex was penetrated in the jet
flow.Moreover,the high value of root mean square of the heat transfer coefficient has spread radially
in stripy manner,which is caused as the results of the longitudinal vortexes flowing in the radial
direction on the impingement plate.     

Numerical simulation on the dynamics of photoinduced cooperative phenomena in molecular crystals

We develop a new simulation method to study the dynamics of initial nucleation processes of photoinduced structural change of molecular crystals. In order to describe the nonadiabatic transition in each molecule, we employ a model of localized electrons coupled with a fully quantized phonon mode, and the time-dependent Schrödinger equation for the model is numerically solved. By applying a mean-field approximation in solving the Schrödinger equation, the calculation method is quite efficient on parallel computing systems. We show that coherently driven molecular distortion plays an important role in the successive conversion of electronic states which leads to photoinduced cooperative phenomena.     

Effects of PbTiO 3 Seed Layer on the Characteristics of RF-Sputtered Pb(Zr 0.5 ,Ti 0.5 )O 3 Thin Films

The effects of seed layers on the characteristics of rf-sputtered lead zirconium titanate thin films were investigated. Prior to sputtering, PbTiO 3 seed layers (100 nm) were deposited onto the Pt/Ti/Si and Pt/Si substrates by sol-gel (spin coating) processing method. Structure-property relation was studied as functions of substrate temperature and sputtering conditions. Special efforts were given in optimizing the deposition parameters to prepare the films in the perovskite phase without post deposition annealing. Dielectric constant and loss tangent of the films were in the range 800-950 and 0.04 -0.06, respectively. Remanent polarization and coercive field were 23.1 w C/cm 2 and 75kV/cm, respectively, for the films without PbTiO 3 seed layer, where as the corresponding quantities for in situ -deposited perovskite Pb(Zr, Ti)O 3 films on PbTiO 3 seed layer were 28 w C/cm 2 and 65 kV/cm, respectively.     

Highly reliable copper dual-damascene interconnects with self-formed MnSi/sub x/O/sub y/ barrier Layer

Copper (Cu) dual-damascene interconnects with a self-formed MnSi/sub x/O/sub y/ barrier layer were successfully fabricated. Transmission electron microscopy shows that approximately 2-nm thick and continuous MnSi/sub x/O/sub y/ layer was formed at the interface of Cu and dielectric SiO/sub 2/, and that no barrier was formed at the via bottom because no oxygen was at the via bottom during annealing. No leakage-current increase was observed, and electron energy loss analysis shows that no Cu was in SiO/sub 2/, suggesting that MnSi/sub x/O/sub y/ layer has sufficient barrier properties for Cu, and that the concept of self-forming barrier process works in Cu dual-damascene interconnects. Via chain yield of more than 90% and 50% reduction in via resistance were obtained as compared with physical vapor deposited tantalum barrier, because there is no barrier at the via bottom. In addition, no failure in the stress-induced voiding measurement was found even after a 1600-h testing. No failure in electromigration (EM) testing was found, as the electron flow is from the lower level interconnects through via up to upper level interconnects even after 1000-h testing. At least, four times EM lifetime improvement was obtained in the case of electron flow from upper level interconnect through via down to lower level interconnects. Significant EM lifetime improvement is due to no flux divergence site at the via bottom, resulting from there being no bottom barrier at the via.     

Photoautotrophic cultures of the host and transformed cells of Marchantia polymorpha under controlled incident light intensity

Photoautotrophic cultures of the host and transformed cells of the liverwort, Marchantia polymorpha, were examined. In cultures in flat glass flasks under various light intensities, it was found that the growth rates of both the cells increased with increase in light intensity in the range of 0 to 25 W/m2, but further increase in light intensity caused photoinhibition of the growth of the cells. Cultures of both the types of cells under light-controlled conditions using an externally illuminated bioreactor were carried out taking into consideration the inhibition of cell growth by excessive light and the light intensity distributions in the cell suspensions. In these cultures, 2.1 (transformed cells) and 3.3 (host cells) kg dry cell weight per m3 were harvested at culture times of 9.0 and 10 d, respectively. These values were larger than those obtained in cultures of the respective cells at a fixed incident light intensity of 25 W/m2.     

Determination of potent odorants in apple by headspace gas dilution analysis

Gas chromatography-olfactometry with headspace gas dilution analysis was used to evaluate the odor potencies of volatile compounds in Fuji apple. To improve the resolution of volatile compounds, the dilution analysis was conducted on two types of capillary columns with different polarities. Thirty three and 20 compounds were identified on DB-WAX and DB-5 columns, respectively. Methyl 2-methylbutanoate, isobutyl acetate, ethyl butanoate, ethyl 2-methylbutanoate, isopentyl formate, butyl acetate and hexyl acetate as well as hexanal were important odor contributors in the headspace gas of apple on the basis of high Flavor Dilution (FD) factors. Threshold values-in-air of these compounds were also estimated from the relationships between their FD factors and concentrations. Methyl 2-methylbutanoate and ethyl 2-methylbutanote were considered as the most potent odorants because of their lowest threshold values. In addition, the threshold values-in-air of isopentyl formate, isopentyl acetate and butyl isobutanoate, which have never been reported, were estimated at 0.149, 1.95 and 0.00607 μl/l, respectively.     

MaMi, a human endometrial stromal sarcoma cell line that constitutively produces interleukin-6, interleukin-8, and monocyte chemoattractant protein-1

BACKGROUND: Uterine endometrial stromal sarcoma is a rare neoplasm with a morphology that closely resembles that of the proliferative endometrial stroma. To understand its pathologic characteristics, we established a novel cell line, MaMi, from a primary culture of an endometrial stromal sarcoma obtained from a 65-year-old Japanese woman. METHODS: We observed the morphology of MaMi cells and performed immunohistochemical analysis on the primary tumor and transplants in nude mice. Prolactin, insulin-like growth factor-binding protein-1, interleukin (IL)-6, IL-8, monocyte chemoattractant protein-1, intercellular adhesion molecule-1, E-selectin, vascular cell adhesion molecule-1, and fibronectin production in the culture medium of MaMi cells were also examined. RESULTS: MaMi cells were shown to exhibit a fibroblast-like morphology in vitro, and they adopted a more elongated appearance in response to 12-O-tetradecanoyl phorbol-13-acetate (TPA). On injection into nude mice, the cells gave rise to subcutaneous tumors. Immunohistologically, both the primary tumor and MaMi cell-induced tumors stained positively with antibodies to neuron-specific enolase or vimentin. MaMi cells constitutively produced IL-6, IL-8, and monocyte chemoattractant protein-1 in vitro. Interleukin-1beta, (100 pmol/L), tumor necrosis factor-alpha (1 nmol/L), and lipopolysaccharide (1 microg/mL) each increased the release of IL-6, IL-8, and monocyte chemoattractant protein-1 by MaMi cells. TPA (10 nmol/L) also stimulated the production of IL-6 and IL-8 by these cells, but inhibited that of monocyte chemoattractant protein-1. CONCLUSIONS: We demonstrated that MaMi cells closely resemble proliferative endometrial stromal cells not only morphologically, but also functionally. This cell line may prove valuable in understanding the role of cytokines produced by tumor cells in the pathogenesis of endometrial stromal sarcoma and may also be useful as an in vitro model of functioning endometrial stromal cells.     

Equilibrium of bod materials in the activated sludge process

A mathematical model based on the equilibrium of BOD materials in the activated sludge process was developed. When the excess sludge is negligibly small and the BOD concentration of the influent is given, the BOD concentration of the activated sludge or mixed liquor and the efficiency of BOD removal are determined only by the aeration period. Moreover, it was verified mathematically that the performance of the activated sludge process became unstable with decrease of the return sludge ratio and the aeration period.