scholarly journals CMA diagrams, inverse wave normal surfaces, and fast and slow wave propagation in the lower hybrid range of frequencies

2020 ◽  
Author(s):  
R. I. Pinsker ◽  
J. J. Larson ◽  
P. J. Adrian
Keyword(s):  
Wave Propagation ◽  
Slow Wave ◽  
Lower Hybrid ◽  
Normal Surfaces ◽  
Wave Normal

scholarly journals LHR effects in nonducted whistler propagation – new observations and numerical modelling

2001 ◽  
Vol 19 (2) ◽  
pp. 147-157 ◽  
Author(s):  
F. Jiřiček ◽  
D. R. Shklyar ◽  
P. Třiska
Keyword(s):  
Wave Propagation ◽  
Numerical Modelling ◽  
Plasma Frequency ◽  
Cutoff Frequency ◽  
Lower Hybrid ◽  
Noise Band ◽  
Maximum Value ◽  
Lower Hybrid Resonance ◽  
Whistler Propagation ◽  
Lower Cutoff

Abstract. VLF-ELF broadband measurements onboard the MAGION 4 and 5 satellites at heights above 1 Re in plasmasphere provide new data on various known phenomena related to ducted and nonducted whistler wave propagation. Two examples are discussed: magnetospherically reflected (MR) whistlers and lower hybrid resonance (LHR) noise band. We present examples of rather complicated MR whistler spectrograms not reported previously and argue the conditions for their generation. Analytical consideration, together with numerical modelling, yield understanding of the main features of those spectrograms. LHR noise band, as well as MR whistlers, is a phenomenon whose source is the energy propagating in the nonducted way. At the plasmaspheric heights, where hydrogen (H+) is the prevailing ion, and electron plasma frequency is much larger than gyrofrequency, the LHR frequency is close to its maximumvalue in a given magnetic field. This frequency is well followed by the observed noise bands. The lower cutoff frequency of this band is somewhat below that maximum value. The reason for this, as well as the possibility of using the LHR noise bands for locating the plasma through position, are discussed.Key words. Magnetospheric physics (plasmasphere; wave propagation)

scholarly journals Abnormal gastric slow waves in patients with functional dyspepsia assessed by multichannel electrogastrography

2001 ◽  
Vol 280 (6) ◽  
pp. G1370-G1375 ◽  
Author(s):  
Xuemei Lin ◽  
Jiande Z. Chen
Keyword(s):  
Wave Propagation ◽  
Functional Dyspepsia ◽  
Slow Wave ◽  
Single Channel ◽  
Slow Waves ◽  
Lower Percentage ◽  
Healthy Controls ◽  
Fasting State ◽  
Gastric Slow Wave ◽  
Gastric Slow Waves

The aim of this study was to utilize multichannel electrogastrography to investigate whether patients with functional dyspepsia had impaired propagation or coordination of gastric slow waves in the fasting state compared with healthy controls. The study was performed in 10 patients with functional dyspepsia and 11 healthy subjects. Gastric myoelectrical activity was measured by using surface electrogastrography with a specially designed four-channel device. The study was performed for 30 min or more in the fasting state. Special computer programs were developed for the computation of the propagation and coupling of the gastric slow wave. It was found that, compared with the healthy controls, the patients showed a significantly lower percentage of slow wave propagation (58.0 ± 8.9 vs. 89.9 ± 2.6%, P < 0.002) and a significantly lower percentage of slow wave coupling (46.9 ± 4.4 vs. 61.5 ± 6.9%, P < 0.04). In addition, the patients showed inconsistencies in the frequency and regularity of the gastric slow wave among the four-channel electrogastrograms (EGGs). It was concluded that patients with functional dyspepsia have impaired slow wave propagation and coupling. Multichannel EGG has more information than single-channel EGG for the detection of gastric myoelectrical abnormalities.

scholarly journals Experimental studies of lower hybrid wave propagation

1976 ◽  
Vol 19 (7) ◽  
pp. 995 ◽  
Author(s):  
P. M. Bellan ◽  
Miklos Porkolab
Keyword(s):  
Wave Propagation ◽  
Experimental Studies ◽  
Lower Hybrid ◽  
Hybrid Wave ◽  
Lower Hybrid Wave
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