scholarly journals Microwave propagation attenuation due to earths atmosphere at very high frequency (VHF) and ultra-high frequency (UHF) bands in Nsukka under a clear air condition

2015 ◽  
Vol 10 (11) ◽  
pp. 359-363 ◽  
Author(s):  
Benjamin Ikechukwu Ugwu Ernest ◽  
Chioma Umeh Maureen ◽  
Josephine Ugonabo Obiageli
Keyword(s):  
High Frequency ◽  
Microwave Propagation ◽  
Very High Frequency ◽  
Ultra High Frequency ◽  
Very High

Thunderstorm Signals at Very-high Frequency and Ultra-high Frequency

Nature ◽  
1955 ◽  
Vol 175 (4465) ◽  
pp. 949-950 ◽  
Author(s):  
D. R. HAY ◽  
T. R. HARTZ
Keyword(s):  
High Frequency ◽  
Very High Frequency ◽  
Ultra High Frequency ◽  
Very High

CLOSED-LOOP SEIZURE CONTROL WITH VERY HIGH FREQUENCY ELECTRICAL STIMULATION AT SEIZURE ONSET IN THE GAERS MODEL OF ABSENCE EPILEPSY

2011 ◽  
Vol 21 (02) ◽  
pp. 163-173 ◽  
Author(s):  
TIMOTHY S. NELSON ◽  
COURTNEY L. SUHR ◽  
DEAN R. FREESTONE ◽  
ALAN LAI ◽  
AMY J. HALLIDAY ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
High Frequency ◽  
Closed Loop ◽  
Absence Epilepsy ◽  
High Frequency Stimulation ◽  
Very High Frequency ◽  
Ultra High Frequency ◽  
Epileptiform Discharges ◽  
Frequency Stimulation ◽  
Very High

A closed-loop system for the automated detection and control of epileptic seizures was created and tested in three Genetic Absence Epilepsy Rats from Strasbourg (GAERS) rats. In this preliminary study, a set of four EEG features were used to detect seizures and three different electrical stimulation strategies (standard (130 Hz), very high (500 Hz) and ultra high (1000 Hz)) were delivered to terminate seizures. Seizure durations were significantly shorter with all three stimulation strategies when compared to non-stimulated (control) seizures. We used mean seizure duration of epileptiform discharges persisting beyond the end of electrical stimulation as a measure of stimulus efficacy. When compared to the duration of seizures stimulated in the standard approach (7.0 s ± 10.1), both very high and ultra high frequency stimulation strategies were more effective at shortening seizure durations (1.3 ± 2.2 s and 3.5 ± 6.4 s respectively). Further studies are warranted to further understand the mechanisms by which this therapeutic effect may be conveyed, and which of the novel aspects of the very high and ultra high frequency stimulation strategies may have contributed to the improvement in seizure abatement performance when compared to standard electrical stimulation approaches.

Street‐Scale Mapping of Urban Radio Frequency Noise at Very High Frequency and Ultra High Frequency

Radio Science ◽  
2019 ◽  
Vol 54 (11) ◽  
pp. 934-948
Author(s):  
Daniel J. Breton ◽  
Caitlin E. Haedrich ◽  
Matthew J. Kamrath ◽  
D. Keith Wilson
Keyword(s):  
Radio Frequency ◽  
High Frequency ◽  
Frequency Noise ◽  
Very High Frequency ◽  
Ultra High Frequency ◽  
Very High
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