16.0% Efficiency of large area (10 cm×10 cm) thin film polycrystalline silicon solar cell

High efficient large area thin film polycrystalline Si solar cell based on a silicon on insulator (SOI) structure prepared by zone-melting recrystallization (ZMR) is reported. Fabrication process of the via-hole etching for the separation of thin films (VEST) is newly developed. It is found that phosphorus treatment and back surface field (BSF) are quite effective for the VEST structure and the ZMR thin film polycrystalline silicon. The conversion efficiency as high as 16.0% for a practical size (10 cm×10 cm) is achieved. This is the highest for large area thin film polycrystalline Si solar cells ever reported.     

The Direct Spectroscopy of Positronium Hyperfine Structure Using a Sub-THz Gyrotron

Positronium is an ideal system for research on Quantum Electrodynamics (QED), especially in a bound state. A discrepancy of 3.9 standard deviations has been found between the measured hyperfine structure (Ps-HFS) and the QED predictions. This may be due to the contribution of unknown new physics or common systematic effects in previous measurements, in all of which the Zeeman effect was used. We propose a new method to directly measure the Ps-HFS using a high power gyrotron. We compare two resonators which have been developed to supply sufficient power to drive the direct transition, a Fabry-Pérot resonator and a ring resonator with a diffraction grating. We plan to perform first direct measurement of Ps-HFS within the next six months.     

A new concept of nuclear fuel reprocessing by applying ion-exchange technology

The development of advanced technology for the spent nuclear fuel reprocessing should be achieved not only considering cost, non proliferation and reduction of radioactive wastes but also corresponding to both spent nuclear fuels of LWR and FBR.

We have proposed an ion exchange process for reprocessing using a new type ion exchanger developed to chemical method of U enrichment technology. This process possess possibility of a sharp cut in cost, since this ion exchanger is characterized by rapid adsorption-desorption rate dominating the treatment rate.

From the basic experimental results, this reprocessing process has been constructed by 3 ion exchanger columns which consist of a main separation column, the uranium-refining column and the plutonium-refining column.

Comparing ion exchange process with the conventional Purex process, this ion exchange process has many advantages such as the decrease in the number and size separation equipment, solvent-spent free and alkaline-liquid-spent free. With these advantages, this process is estimated that the construction cost of reprocessing process is greatly reduced comparing to the conventional process.     

Assembly characteristics of flagellar cap protein HAP2 of Salmonella: decamer and pentamer in the pH-sensitive equilibrium

The folding of a 98 residue protein, muscle acylphosphatase (AcP), has been studied using a variety of techniques including circular dichroism, fluorescence and NMR spectroscopy following transfer of chemically denatured protein into refolding conditions. A low-amplitude phase, detected in concurrence with the main kinetic phase, corresponds to the folding of a minor population (13%) of molecules with one or both proline residues in a cis conformation, as shown from the sensitivity of its rate to peptidyl prolyl isomerase. The major phase of folding has the same kinetic characteristics regardless of the technique employed to monitor it. The plots of the natural logarithms of folding and unfolding rate constants versus urea concentration are linear over a broad range of urea concentrations. Moreover, the initial state formed rapidly after the initiation of refolding is highly unstructured, having a similar circular dichroism, intrinsic fluorescence and NMR spectrum as the protein denatured at high concentrations of urea. All these results indicate that AcP folds in a two-state manner without the accumulation of intermediates. Despite this, the folding of the protein is extremely slow. The rate constant of the major phase of folding in water, kfH2O, is 0.23 s-1 at 28 degreesC and, at urea concentrations above 1 M, the folding process is slower than the cis-trans proline isomerisation step. The slow refolding of this protein is therefore not the consequence of populated intermediates that can act as kinetic traps, but arises from a large intrinsic barrier in the folding reaction.     

Clonidine and lidocaine inhibition of isoflurane-induced tachycardia in humans

BACKGROUND: A rapid increase in isoflurane concentration can induce tachycardia and hypertension and increase plasma catecholamine concentrations. To investigate a possible mechanism, we measured hemodynamic responses to isoflurane administered via mask; we also administered clonidine for premedication, lidocaine topically to the nasal mucosa, or lidocaine intravenously to evaluate the effect of these drugs on the hemodynamic responses. METHODS: Forty ASA physical status 1 patients (aged 20-30 yr) scheduled for elective oral surgery participated in the study. Thirty patients were randomly allocated to one of three groups: a control group, a group receiving 3-4 micrograms.kg-1 of oral clonidine for premedication, and a group receiving 2 ml of 4% lidocaine spray to the nasal mucosa. Ten patients were assigned nonrandomly to a group receiving intravenous lidocaine continuously (0.4 mg.kg-1 bolus followed by 30 micrograms.kg-1.min-1) after the initial randomized experiments were done to test whether systemic lidocaine blunts the responses to inhaled isoflurane. Anesthesia was induced with thiamylal, after which inhalation of 1% isoflurane in 100% oxygen via mask was begun. The inspired concentration of isoflurane was increased by 1% every 5 min to a maximum of 4%. During normocapnia and without surgical stimulation, heart rate and systolic blood pressure were measured every minute for 20 min before and during isoflurane inhalation. Plasma catecholamine concentrations were measured before and at each isoflurane concentration. RESULTS: In the control and intravenous lidocaine groups, an increase in isoflurane concentration from 2% to 3% significantly increased systolic blood pressure (peak changes of 16 +/- 5 and 15 +/- 6 mmHg, respectively) and heart rate (peak changes of 23 +/- 3 and 13 +/- 4 beats.min-1, respectively). A change in concentration to 4%, however, did not significantly alter hemodynamics. Blood pressure and heart rate responses to a change to 3% isoflurane were significantly blunted in the groups receiving clonidine (peak changes of 4 +/- 4 mmHg and 8 +/- 3 beats.min-1, respectively) or nasal lidocaine (peak changes of 2 +/- 1 mmHg and 4 +/- 2 beats.min-1, respectively) compared with the control group. In all groups, plasma epinephrine and norepinephrine concentrations increased after administration of 2% and 1% isoflurane, respectively. Plasma lidocaine concentrations were 0.3-1.3 micrograms.kg-1 in the nasal lidocaine group and 0.6-1.5 micrograms.kg-1 in the intravenous lidocaine group. CONCLUSIONS: Stepwise increases in isoflurane concentration elicited hypertension and tachycardia as well as increments in plasma catecholamine concentrations during mask anesthesia. Nasal administration of lidocaine and clonidine premedication significantly blunted the circulatory responses to isoflurane. Intravenous lidocaine did not significantly weaken the responses to changes in isoflurane concentration.     

New manufacturing techniques of large forged shell rings for pressure vessels

A 250 ton hollow ingot was made for experimental purposes so that the properties of a large-sized hollow ingot could be simulated. The investigation results indicated that this ingot was suitable for forged shell rings of nuclear reactor pressure vessels (RPV). They were used in the manufacture of forged shell rings for an RPV of a 1300 MW type PWR and for an RPV of an 1100 MW type BWR using basic oxygen furnace, RH degassing, hollow ingot-making process. These shell rings had less segregation and clean inner surfaces which are attributed to the homogeneity of the hollow ingot.     

Secretion-recapture process of apolipoprotein E in hepatic uptake of chylomicron remnants in transgenic mice

To investigate the role of apoE in hepatic uptake of chylomicron remnants, we studied chylomicron metabolism in transgenic mice overexpressing apoE in the liver. Plasma clearance of injected 125I-labeled human chylomicrons was fivefold faster in transgenic mice than in controls. Immunohistochemistry demonstrated that apoE was specifically localized at the basolateral surface of hepatocytes from fasted transgenic mice. After injection of a large amount of chylomicrons, the density of the cell surface apoE was markedly reduced and vesicular staining was observed in the cytoplasm, suggesting that the cell surface apoE was used for hepatic endocytosis of chylomicrons and remnants. Polyacrylamide gel analysis of chylomicrons and remnants that had been reisolated from plasma and from liver membrane after the injection of chylomicrons showed the particles to be enriched with apoE mainly after their influx into the liver rather than during their residence in plasma. These results provide strong evidence for the secretion-recapture process of apoE, whereby chylomicron remnants enter the sinusoidal space, acquire apoE molecules, and subsequently are endocytosed. Data from experiments with very low density lipoprotein and LDL showed that this system is specific for chylomicron remnants.