38 research outputs found
Extension of the operational regime of the LHD towards a deuterium experiment
As the finalization of a hydrogen experiment towards the deuterium phase, the exploration of the best performance of hydrogen plasma was intensively performed in the large helical device. High ion and electron temperatures, Ti and Te, of more than 6 keV were simultaneously achieved by superimposing high-power electron cyclotron resonance heating onneutral beam injection (NBI) heated plasma. Although flattening of the ion temperature profile in the core region was observed during the discharges, one could avoid degradation by increasing the electron density. Another key parameter to present plasma performance is an averaged beta value . The high regime around 4% was extended to an order of magnitude lower than the earlier collisional regime. Impurity behaviour in hydrogen discharges with NBI heating was also classified with a wide range of edge plasma parameters. The existence of a no impurity accumulation regime, where the high performance plasma is maintained with high power heating >10 MW, was identified. Wide parameter scan experiments suggest that the toroidal rotation and the turbulence are the candidates for expelling impurities from the core region
Echocardiographic Evaluation of Postoperative Coaptation Geometry of Left AV Valve in Complete Atrioventricular Septal Defect
Background: We sought to determine the difference in geometric parameters in the left atrioventricular valve (LAVV) postoperative complete atrioventricular septal defect (CAVSD) compared to the normal heart, and the correlation between geometric and functional parameters for detecting the mechanism of LAVV regurgitation (LAVVR) in CAVSD. Methods: LAVV geometric parameters based on complete and acceptable quality echocardiograms of 18 patients with repaired CAVSD compared with 17 normal controls. LAVVR severity was also quantified by indexed vena contracta (I-VC) (mm) and % jet area/left atrium area (% Jet/LA), and the correlation with LAVV parameters in the CAVSD group was investigated. Results: In the CAVSD group, the posterior closing angle (Pc) was nearly the same as the anterior closing angle (Ac), yet in the normal heart, the Pc angle was double the Ac angle. The anterior opening angle (Ao) and posterior-to-anterior leaflet diameter ratio (a/p) in the CAVSD group was also significantly smaller. The CAVSD group also had a shorter indexed coaptation length (I-CL) and indexed tenting height (I-TH). Displacement length (ΔD) differed completely between the CAVSD and Normal groups, and also showed a strong positive correlation to the functional parameters of LAVVR (% Jet/LA: r = .70, P = .02; I-VC: r = .60, P = .02). Conclusions: The parameters in this study were applicable to CAVSD AV valve coaptation characteristics. We introduced 2 novel measures that may provide important insights into the differences in geometry and performance of the LAVV in repaired CAVSD as compared to normal hearts
Single Molecule of a π-Conjugated Polymer Slowly Twinkles in Solution at Room Temperature
A phenylacetylene monomer, 4-(decyloxycarbonyl)phenylacetylene (DecCPA), was synthesized and polymerized by using the combined catalyst system, i.e., [Rh(norbornadiene)Cl]_2 and triethylamine, to give a yellow solid π-conjugated polymer [poly(DecCPA)] having the high molecular weight and the cis-transoidal stereo-regular main chain. Poly(DecCPA) was measured using total internal reflection fluorescence microscopy, which is a single molecule detection technique that is carried out in tetrahydrofuran solution at room temperature, and the light-twinkling of a single molecule was observed. This twinkling is the dynamic photon emission phenomenon of single poly(DecCPA) molecule that we mention specifically as resultant from the time scale-changing very slowly in the time scale of milliseconds and seconds-with changed fluorescent intensity associated with single polymer molecule conformational changing caused by the micro-Brownian motion. Although a molecular dynamics was at the picosecond time scale generally, this poly(DecCPA) molecule had the mode of the molecular motion of π-conjugated main chain did this very slowly in a second time scale was shown