ABSTRACT
Two-photon laser-induced fluorescence measurements were performed on the helicity injected torus (HIT-SI3) device to determine the density and temperature of the background neutral deuterium population. Measurements were taken in 2 ms long pulsed plasmas after the inductive helicity injectors were turned off. Attempts to measure neutrals during the main phase of the plasma were unsuccessful, likely due to the density of neutrals being below the detection threshold of the diagnostic. An unexpectedly low density of atomic deuterium was measured in the afterglow; roughly 100 times lower than the theoretical prediction of 1017 m-3. The neutral temperatures measured were on the order of 1 eV. Temporally and spatially resolved neutral density and temperature data are presented.
ABSTRACT
OBJECTIVE: The purpose of this study was to investigate the effect of head positions on high frequency tympanometry (HFT) results obtained from neonates. DESIGN: A cross-sectional study to compare HFT results obtained from neonates in two head positions (face sideways and face up). STUDY SAMPLE: One hundred and fifty-seven neonates (80 female, 77 male; mean age = 48.3 ± 26.7 hours) participated. RESULTS: The mean uncompensated admittance at 200 daPa obtained in the face sideways position was significantly greater than that obtained in the face up position (1.02 versus 0.96 mmho). A significant ear effect for baseline compensated admittance was found (right/left = 0.64/0.53 mmho). However, there were no significant main effects for head positions for the tympanometric peak pressure, baseline compensated static admittance, and component compensated static admittance measures, indicating that these measures are resilient to head positions. CONCLUSION: These findings support the use of HFT normative values regardless of the two head positions investigated in the present study.
