GENERATION OF A LOW-FREQUENCY INDUCTIVE DISCHARGE AT ATMOSPHERIC PRESSURE

2021 ◽  
Vol 62 (4) ◽  
pp. 593-599
Author(s):  
M. V. Isupov ◽  
A. Yu. Litvintsev
Keyword(s):  
Atmospheric Pressure ◽  
Low Frequency ◽  
Inductive Discharge

The driving frequency effects on the atmospheric pressure corona jet plasmas from low frequency to radio frequency

2011 ◽  
Vol 18 (4) ◽  
pp. 043503 ◽  
Author(s):  
Dan Bee Kim ◽  
H. Jung ◽  
B. Gweon ◽  
S. Y. Moon ◽  
J. K. Rhee ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Atmospheric Pressure ◽  
Low Frequency ◽  
Driving Frequency ◽  
Frequency Effects

Continental shelf waves and their influence on the circulation around the Great Barrier Reef

1983 ◽  
Vol 34 (1) ◽  
pp. 23 ◽  
Author(s):  
E Wolanski ◽  
AF Bennett
Keyword(s):  
Continental Shelf ◽  
Great Barrier Reef ◽  
Sea Level ◽  
Atmospheric Pressure ◽  
Low Frequency ◽  
Internal Tides ◽  
Wind Component ◽  
Barrier Reef ◽  
Longshore Current ◽  
Shelf Waves

Winds and atmospheric pressure, sea level and water currents were measured at several locations over the continental shelf, both east and west of the Great Barrier Reef, between 14.5�s. and 20�S., from June to November 1980. The dominant wind direction changed from westward over the Coral Sea to north- westward (roughly parallel to the shore) over the shelf. A strong non-tidal low-frequency signal in all sea- level and longshore current data was found, highly coherent from site to site and strongly correlated with the longshore wind component over the shelf, though not with the atmospheric pressure. A model of wind- driven barotropic shelf waves is used to explain a number of observations, such as the invariance of temporal fluctuations of longshore current with distance from shore, and the northward longshore propagation of oceanic disturbances at a speed equal to twice that of the first-mode barotropic free shelf wave, a speed one order of magnitude smaller than that of the wind system. The low-frequency current fluctuations resulted in large water displacements, up and down the coast. Low-frequency cross-shelf currents were much weaker and less coherent. Two upwelling mechanisms are internal tides and internal Kelvin waves coupled to the barotropic shelf waves.

scholarly journals Meteorological effects in the lower ionosphere as based on VLF/LF signal observations

2014 ◽  
Vol 2 (4) ◽  
pp. 2789-2812 ◽  
Author(s):  
A. Rozhnoi ◽  
M. Solovieva ◽  
B. Levin ◽  
M. Hayakawa ◽  
V. Fedun
Keyword(s):  
Gravity Waves ◽  
Atmospheric Pressure ◽  
Low Frequency ◽  
Lower Ionosphere ◽  
Signal Amplitude ◽  
Internal Gravity Waves ◽  
Atmospheric Parameters ◽  
Low Latitudes ◽  
Far Eastern ◽  
Meteorological Effects

Abstract. Very low and low frequency (VLF/LF) data recorded in the Far Eastern stations Petropavlovsk-Kamchatsky (158.92° E, 53.15° N), Yuzhno-Sakhalinsk (142.75° E, 46.95° N) and Yuzhno-Kurilsk (145.861° E, 44.03° N) are investigated to study the meteorological effects in the lower ionosphere. The results demonstrate the sensitivity of the VLF/LF signals to the variations of atmospheric pressure, humidity, wind velocity and temperature, and the VLF/LF record at the station of Yuzhno-Kurilsk is found to be most sensitive to those variations of atmospheric parameters. The region under consideration is characterized by high winter cyclonic activity in midlatitudes and strong summer and autumn typhoon activity in low latitudes. VLF/LF signal variations during 8 tropical cyclones (TCs) with different intensity are considered. Negative nighttime anomalies in the signal amplitude that are most probably caused by TC activity are found for 6 events. Those anomalies are observed during 1–2 days when TCs move inside the sensitivity zones of the subionospheric paths. Perturbations of the VLF signal observed during 2 TCs can be caused by both the TC influence and seismic activity, but no correlation between TC intensity and magnitude of the signal anomalies is found. Spectral analysis of the typhoon-induced disturbed signals revealed the fluctuations with time periods in the range of 7–16 and 15–55 min that corresponds to the range of internal gravity waves periods.

scholarly journals Development of mathematical model of extraction from lupine with cheese serum by applying low-frequency mechanical vibrations

2019 ◽  
Vol 81 (1) ◽  
pp. 36-41 ◽  
Author(s):  
J. I. Shishatsky ◽  
A. M. Barbashin ◽  
S. A. Nickel
Keyword(s):  
Balance Equation ◽  
Atmospheric Pressure ◽  
Effective Diffusion ◽  
Low Frequency ◽  
Pressure Change ◽  
Mechanical Vibrations ◽  
Capillary Impregnation ◽  
Initial Stage ◽  
Impregnation Time ◽  
Substance Transfer

It is noted that the model is designed to create the largest possible pressure change in the cheese whey in the extractor, since the rate of transfer of the target components is proportional to the pressure difference at the ends of the capillaries. The mathematical description of impregnation as the main or important auxiliary operation is given in detail. The equations for the impregnated part of the capillary, the ratio of impregnation rates at different times are given. From the above dependencies, the equation Washburne regarding the time of impregnation. The formulas for calculating the volume of extractant passed through the capillary, serum and forced out of the capillary air taking into account the viscous resistance of the latter. After integration of the equation of the speed of capillary impregnation of the obtained expression allows to estimate the final value of the impregnation in the initial stage. For different cases of capillary impregnation expressions are written at atmospheric pressure, vacuuming and overpressure. The introduction of dimensionless values allowed to simplify the solution and to obtain an expression for calculating the time of pore impregnation. The analysis of the equation of dimensionless impregnation time taking into account the application of low-frequency mechanical vibrations is made. It is noted that the processes of impregnation and extraction occur simultaneously, so the impregnation time is often neglected, which impoverishes the understanding of the physics of the process, reduces the accuracy of the calculation. Taking into account the diffusion unsteadiness of the process of substance transfer due to hydrodynamic unsteadiness, the equation containing the effective diffusion coefficient is written. The equation of unsteady diffusion for a spherical lupine particle in a batch extractor is supplemented with initial and boundary conditions. Taking into account the balance equation, the kinetic equation of the process is obtained. We studied the distribution of pores in the particle lupine along the radii and squares, the calculated value of the porosity of the particle. The values of De and Bi are determined by the method of graphical solution of the balance equation, the equation of kinetics and the parameters included in these equations. Conclusions on the work.

scholarly journals Relationship between the Persian Gulf Sea-Level Fluctuations and Meteorological Forcing

2020 ◽  
Vol 8 (4) ◽  
pp. 285
Author(s):  
Naghmeh Afshar-Kaveh ◽  
Mostafa Nazarali ◽  
Charitha Pattiaratchi
Keyword(s):  
Sea Level ◽  
Persian Gulf ◽  
Atmospheric Pressure ◽  
Tide Gauge ◽  
Low Frequency ◽  
Northern Coast ◽  
Meteorological Forcing ◽  
Sea Level Fluctuations ◽  
Coastal Sea ◽  
The Persian Gulf

Sea-level data from six tide gauge stations along the northern coast of the Persian Gulf were analyzed both in time and frequency domain to evaluate meteorological forcing. Spectral analyses indicated that mixed, predominantly semi-diurnal tides were dominant at all stations, but low-frequency fluctuations correlated well with atmospheric pressure and wind components. Non-tidal sea-level fluctuations up to 0.75 m were observed along the northern coasts of the Gulf due to the combined action of lower atmospheric pressure and cross-shore wind. Coherency between low-frequency sea-level records and mean sea-level pressure indicated that the latter usually leads to sea-level fluctuations between 1 and 6.4 days. In contrast, the same analysis on the wind velocity and sea level revealed that the former lags between 3 and 13 days. The effect of wind stress on coastal sea-level variations was higher compared with the effect of atmospheric pressure. Concurrent analysis of low-pass-filtered sea-level records proved that the non-tidal wave moves from west to east along the northern coasts of the Persian Gulf.

Sign in / Sign up

Export Citation Format

Share Document