scholarly journals Technology improvement of ultrasonic refinement of machinery work surfaces based on phenomenological investigation of cavity formations

2017 ◽  
Vol 2 (1) ◽  
pp. 16-21
Author(s):  
Сергей Сундуков ◽  
Sergey Sundukov ◽  
Равиль Нигметзянов ◽  
Ravil Nigmetzyanov ◽  
Дмитрий Фатюхин ◽  
...  
Keyword(s):  
High Frequency ◽  
High Speed ◽  
Acoustic Pressure ◽  
High Frequency Oscillation ◽  
Frequency Oscillation ◽  
Technology Improvement ◽  
Depth Study ◽  
Definition Of ◽  
The Given ◽  
Small Bubbles

The study of processes based on cavitation use required a clear definition of phenomena arising in liquid at high-frequency oscillation impact upon it. For the in-depth study of the phenomena under investigation in the given work there was used a high-speed video filming. As the analysis of high-speed filming has shown after closing a bubble is divided into many pieces which, in their turn, pulse in-phase. At the same time there is observed a formation of complex bubble formations which are offered to be called clusters (Fig. 3). Bubbles formed under the influence of variable acoustic pressure and located at a small distance from each other combine. Two processes take place simultaneously – bubbles combining (coalescence) and the integration of small bubbles in larger ones under the influence of cohesion forces with the formation of general structures (coagulation). The coalescence is followed with the transition of a system in a state with lower free energy.

High-Frequency Oscillation and Chronic Lung Disease in Very Low Birth Weight Infants

PEDIATRICS ◽  
2001 ◽  
Vol 108 (1) ◽  
pp. 212-214
Author(s):  
J. P. Shenai; ◽  
P. Rimensberger; ◽  
U. Thome ◽  
F. Pohlandt; ◽  
P. Rimensberger
Keyword(s):  
Birth Weight ◽  
Low Birth Weight ◽  
Lung Disease ◽  
Chronic Lung Disease ◽  
High Frequency ◽  
Very Low Birth Weight ◽  
High Frequency Oscillation ◽  
Frequency Oscillation ◽  
Low Birth Weight Infants

scholarly journals A Comprehensive Investigation on High-Frequency Oscillation in DC Microgrid

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Mohammad Habibullah ◽  
Nadarajah Mithulananthan ◽  
Krischonme Bhumkittipich ◽  
Mohammad Amin
Keyword(s):  
High Frequency ◽  
High Frequency Oscillation ◽  
Frequency Oscillation ◽  
Comprehensive Investigation ◽  
Dc Microgrid

scholarly journals Distinct EEG seizure patterns reflect different seizure generation mechanisms

2015 ◽  
Vol 113 (7) ◽  
pp. 2840-2844 ◽  
Author(s):  
Pariya Salami ◽  
Maxime Lévesque ◽  
Jean Gotman ◽  
Massimo Avoli
Keyword(s):  
High Frequency ◽  
Channel Blocker ◽  
Seizure Activity ◽  
Low Voltage ◽  
High Frequency Oscillation ◽  
Seizure Onset ◽  
Frequency Oscillation ◽  
Oscillation Analysis ◽  
Pilocarpine Model ◽  
Generation Mechanisms

Low-voltage fast (LVF)- and hypersynchronous (HYP)-seizure onset patterns can be recognized in the EEG of epileptic animals and patients with temporal lobe epilepsy. Ripples (80–200 Hz) and fast ripples (250–500 Hz) have been linked to each pattern, with ripples predominating during LVF seizures and fast ripples predominating during HYP seizures in the rat pilocarpine model. This evidence led us to hypothesize that these two seizure-onset patterns reflect the contribution of neural networks with distinct transmitter signaling characteristics. Here, we tested this hypothesis by analyzing the seizure activity induced with the K+ channel blocker 4-aminopyridine (4AP, 4–5 mg/kg ip), which enhances both glutamatergic and GABAergic transmission, or the GABAA receptor antagonist picrotoxin (3–5 mg/kg ip); rats were implanted with electrodes in the hippocampus, the entorhinal cortex, and the subiculum. We found that LVF onset occurred in 82% of 4AP-induced seizures whereas seizures after picrotoxin were always HYP. In addition, high-frequency oscillation analysis revealed that 4AP-induced LVF seizures were associated with higher ripple rates compared with fast ripples ( P < 0.05), whereas picrotoxin-induced seizures contained higher rates of fast ripples compared with ripples ( P < 0.05). These results support the hypothesis that two distinct patterns of seizure onset result from different pathophysiological mechanisms.

Aerosol deposition in the human lung: Effect of high-frequency oscillation on the deposition characteristics of an inhaled nebulized aerosol

1988 ◽  
Vol 75 (5) ◽  
pp. 535-542 ◽  
Author(s):  
Simon H. L. Thomas ◽  
Jackie A. Langford ◽  
Robert J. D. George ◽  
Duncan M. Geddes
Keyword(s):  
Deposition Rate ◽  
High Frequency ◽  
Regional Distribution ◽  
Normal Subjects ◽  
Aerosol Deposition ◽  
High Frequency Oscillation ◽  
Particle Sizes ◽  
Frequency Oscillation ◽  
Regional Deposition ◽  
Peripheral Lung

1. Oral high-frequency oscillation (OHFO) may have important effects on aerosol deposition in the lungs. In order to investigate these, a technique was devised to measure regional deposition rates of a nebulized radio-labelled aerosol in the lungs during normal tidal breathing. 2. The effect of three frequencies of OHFO on pulmonary aerosol deposition rate (PADR) in four normal subjects and five patients with chronic airways obstruction (CAO) were assessed using the technique. 3. In separate experiments employing three normal subjects, the effect of OHFO was studied on the deposition rate of aerosol on the oropharynx and delivery apparatus, and on the amount and characteristics of aerosol inhaled by the subjects. 4. Total PADR was significantly reduced by OHFO at 8 Hz and 16 Hz in the normal subjects, and by all three frequencies of OHFO in the CAO patients. In the normal subjects, the regional distribution of aerosol deposition was unchanged, but in the CAO patients a larger proportion of total aerosol deposition occurred in peripheral lung. 5. OHFO reduced the oropharyngeal aerosol deposition rate, increased the loss of aerosol to the atmosphere before inhalation, and increased the deposition of aerosol on the delivery apparatus. The end result was a reduction in the amount of aerosol inhaled, and in the particle sizes measured at the mouthpiece. 6. We conclude that OHFO reduces the amount of aerosol inhaled, but may improve peripheral deposition of inhaled aerosol in patients with CAO. This effect may be of value in the clinical administration of nebulized drugs.

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