Three-dimensional observation system for pellet ablation traveling in the high-temperature plasmas

In order to investigate the ablation of a solid hydrogen pellet, which is injected into a high-temperature plasma with high speed (~1 km/s) for the plasma refueling, a three-dimensional observation system using a fast camera has been developed. A stereo method has been employed to obtain the three-dimensional information of the pellet ablation. A pair of the stereo images, which have been taken from different locations, has been focused onto a single fast camera by using a bifurcated fiber scope to ensure the simultaneity of both images. The projection matrix, which is used for stereo reconstruction, is calibrated by taking images of a model plane of known coordinates from the actual camera positions. The measuring error of the stereo observation is within 2% in the depth direction

Statistical Analysis of Pressure Fluctuations in Vertical Two-Phase Flow

An experimental study was conducted on pressure fluctuations in vertical two-phase air-water flow. Statistical analysis of measured fluctuations was used to identify flow regimes in two-phase flow. Random ripple fluctuations were observed in bubbly flow. In slug and churn flows, however, violent oscillations were caused by the periodic passage of liquid and gas slugs. These oscillations-were weakened with a further in-crease of gas flowrate, and small ripple fluctuations again appeared in annular flow

甲状軟骨形成術Ⅰ型と声帯内自家脂肪注入術との治療成績の検討

Objective: Type-I thryroplasty, also known as medialization thyroplasty (MT) and autologous fat injection laryngoplasty (FIL) are one of the main surgical treatments for unilateral vocal fold paralysis (UVFP). Both procedures have the same concept of completing the glottal closure by medializing the vocal fold, although the surgical approaches are quite different. In order to assess these surgical effects, we examined the treatment outcomes and benefits of the two surgeries. Methods: We collected data from the 135 phonosurgeries that we performed out of 375 patients with UVFP at Osaka Voice Center, Osaka Kaisei Hospital from January 2009 to February 2013. After excluding cases with glottal level differences on phonation, either MT or FIL were performed on 80 cases. The inclusion criteria for the present study were: (1) patients had no history of previous phonosurgery, and (2) functional evaluations were available before/after surgery. Consequently, 43 participants (12 for MT and 31 for FIL) were enrolled in this study. Surgical effects were evaluated by means of the maximum phonation time (MPT), pitch period perturbation quotient (PPQ), amplitude perturbation quotient (APQ), and harmonic to noise ratio (HNR) just before, one month, and 6 months after surgery. Results: Both MT and FIL showed significant improvement in MPT (MT, p = 0.005; FIL, p < 0.001) and PPQ (MT, p = 0.047; FIL, p = 0.041) at 1 month postoperation. We also compared the variation of each variable between the two procedures, but there were no significant differences in these parameters. However, MPT, APQ, and HNR at the post-MT after 6 months worsened compared to those at 1 month posttreatment, whereas MPT showed only a slight decrease from the 1st month to the 6th month in those with FIL. Conclusion: Both MT and FIL were effective for the voice recovery in patients with UVFP. Our findings suggest that surgical results in FIL might be better than those in MT 6 months after surgery, although there were no significant differences between these two procedures 1 month postoperation.博士（医学）・乙第1490号・令和2年12月24日Copyright © 2020 Oto-Rhino-Laryngological Society of Japan Inc. Published by Elsevier B.V

カットイデアルのグレブナー基底とその応用

関西学院大

Electron Beam Lithography for Large Area Patterning 1: Development of Large Field Deflection E-Beam Lithography System

A novel electron beam system has been designed and developed specifically for large area patterning of electronic devices such as printed wiring boards. The prototyped system features a large field deflection, high scanning speed and stably focused beam in the large field. An electron gun with a LaB5 flat cathode was used by operating at 1750-1800 K. The electron beam column provides an electron probe of less than 40 μm in diameter with a current of 50 μA at 60 kV. Fast and large field deflections by a magnetic deflection system enables an area of 104 mm x 104 mm to be covered. The scanning speed can range up to 254 m/s. Particular attention was paid to the materials and shapes of the optics column to minimize the influence of eddy currents from the point of view of controlling the dynamic behavior of beam deflection. It is confirmed that the system can provide accurate beam deflection within a ±20 μm (3) tolerance for the quite large field of 52 mm x 52 mm

Observation of a Rotating Radiation Belt in LHD

A poloidally rotating radiation belt with helical structure was observed during the high density discharges with detachment by photodiode fan arrays and a fast camera in LHD. The peak of radiation rotates inside the last closed flux surface, and the direction and mode number of the poloidal rotation are electron diamagnetic and one, respectively. During the recombination phase after termination of the plasma heating, the rotation continues, and its rotating radius shrinks with shrinking of the plasma column. The poloidal rotating frequency depends on the heating power, and increases from the orders of several tens of Hz to several hundreds of Hz with shrinking of the rotation radius. The mechanism of the rotation remains uncertain

Surface morphology of tungsten exposed to helium plasma at temperatures below fuzz formation threshold 1073 K

Impact of crystal orientation on the surface morphology of the helium plasma exposed tungsten has been investigated on the linear device PSI-2. A nanoscale undulating surface structure having a periodic arrangement is formed for temperatures below 1073 K, in contrast to the fuzz nanostructure formation in a higher temperature range. The crests of undulation align with the  〈1 0 0〉  direction. The interval of the undulation is narrowest at the crystal grainof {1 1 0} surface. The interval becomes wider as the crystal grain surface tilts away from the {1 1 0} surface, and the undulating surface structure is not formed near the {1 0 0} surface. The height of undulations is 8 nm, independently of the interval of the undulations, and it corresponds to the depth of the layer heavily damaged due to helium plasma exposure