Reexamination of recent experimental results in surface‐wave‐produced argon plasmas at 2.45 GHz: Comparison with the diffusion‐recombination model results

Oblique projection polarization filter (OPPF) can be applied as an effective approach for interference cancellation in high-frequency surface wave radar (HFSWR) and other systems. In order to suppress the nonstationary ionosphere clutter further, a novel OPPF based clutter suppressing scheme is proposed in this paper. The polarization and nonstationary characteristic of the clutter are taken into account in the algorithms referred to as range-Doppler domain polarization suppression (RDDPS) and the range-time domain polarization suppression (RTDPS) method, respectively. The RDDPS is designed for weak ionosphere clutter and implemented in the range-Doppler domain directly, whereas the RTDPS algorithm is designed to suppress the powerful ionosphere clutter with a multisegment estimation and suppression scheme. About 15–23 dB signal to interference ratio (SIR) improvement can be excepted when using the proposed method, whereas the targets can be more easily detected in the range-Doppler map. Experimental results demonstrate that the scheme proposed is effective for nonstationary ionosphere clutter and is proven to be a practical interference cancellation technique for HFSWR.

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Berechnungen zur isentropen Entspannung eines Argon-Plasmas in einer Laval-Düse

Zeitschrift für Naturforschung A ◽

10.1515/zna-1965-0806 ◽

1965 ◽

Vol 20 (8) ◽

pp. 1027-1030 ◽

Cited By ~ 1

Author(s):

J. Artmann

Keyword(s):

Thermodynamic Equilibrium ◽

Laval Nozzle ◽

Experimental Results ◽

Simplified Model ◽

Plasma Parameters ◽

Argon Plasmas ◽

Isentropic Flow

Neglecting magnetic and electric forces which occure in the expansion of a plasma in a LAVAL nozzle the plasma parameters are calculated by means of a simplified model 3 under the condition of isentropic flow. An Ein-Stufen-Modell and a Zwei-Stufen-Modell 1 is applied. It proves that the experimental results at hand can only be explained by means of the Zwei-Stufen-Modell. The calculations include the case of thermodynamic equilibrium as well as that of frozen flow.

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Comparison of 2D Hybrid Simulational and Experimental Results for Dual-Frequency Capacitively Coupled Argon Plasmas

Plasma Science and Technology ◽

10.1088/1009-0630/13/2/11 ◽

2011 ◽

Vol 13 (2) ◽

pp. 181-187 ◽

Cited By ~ 10

Author(s):

Zhenhua Bi ◽

Xiang Xu ◽

Yongxin Liu ◽

Xiangzhan Jiang ◽

Wenqi Lu ◽

...

Keyword(s):

Experimental Results ◽

Dual Frequency ◽

Capacitively Coupled ◽

Argon Plasmas

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Spectroscopic Characterization of Two Different Microwave (2.45 GHz) Induced Argon Plasmas at Atmospheric Pressure

Applied Spectroscopy ◽

10.1366/0003702053641405 ◽

2005 ◽

Vol 59 (4) ◽

pp. 519-528 ◽

Cited By ~ 28

Author(s):

M. C. García ◽

C. Yubero ◽

M. D. Calzada ◽

M. P. Martínez-Jiménez

Keyword(s):

Surface Wave ◽

High Power ◽

Atmospheric Pressure ◽

Emission Spectroscopy ◽

Optical Emission Spectroscopy ◽

Optical Emission ◽

Spectroscopic Characterization ◽

Argon Plasmas ◽

Sustained Discharge

A surface-wave-sustained discharge created by using a surfatron device in a tube open to the atmosphere can be used to maintain a microwave (2.45 GHz) plasma at atmospheric pressure at powers of less than 300 W. The TIA ( Torche à Injection Axiale) is a device also producing a plasma that, moreover, permits us to work at high power (higher than 200 W and up to 1000 W). A study of the departure from the thermodynamic equilibrium existing in the argon plasmas created by both devices has been done by using optical emission spectroscopy techniques in order to characterize them and to evaluate their possible advantages when they are used for applied purposes.

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Surface Wave Contours Associated with the Forebody Wake of Stepped Planing Hulls

Marine Technology and SNAME News ◽

10.5957/mtsn.2010.47.1.1 ◽

2010 ◽

Vol 47 (01) ◽

pp. 1-16

Author(s):

Daniel Savistky ◽

Michael Morabito

Keyword(s):

Surface Wave ◽

Model Tests ◽

Experimental Results ◽

Empirical Equations ◽

Stagnation Line

Results of an extensive series of model tests that define the longitudinal surface wake profiles aft of prismatic hulls having deadrise angles of 10º, 20º and 30º are presented. Empirical equations are developed that quantitatively define these profiles and are in a form that can be easily applied by designers of stepped planing hulls. These equations are applicable for an expected range of variations in trim angle, speed coefficient, and loading coefficient typical for these hulls. A brief introduction to the concept and to the hydrodynamic advantages of stepped planing hulls is presented to orient the reader as to the importance of wake data in their design. Examples are presented that illustrate the application of these wake data for stepped planing hulls with wetted forebody chine to achieve maximum hydrodynamic lift/drag ratios. Finally experimental results are presented that illustrate the potential resistance penalty associated with the operation of chines dry forebodies where the stagnation line crosses the step.

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A Methodology for Controlling Slopping in Copper Converters by Using Lateral and Bottom Gas Injection

International Journal of Chemical Reactor Engineering ◽

10.2202/1542-6580.1868 ◽

2009 ◽

Vol 7 (1) ◽

Cited By ~ 1

Author(s):

Marco Rosales ◽

Alvaro Valencia ◽

Ramón Fuentes

Keyword(s):

Surface Wave ◽

Froude Number ◽

Refractory Lining ◽

Gas Injection ◽

Standing Waves ◽

High Amplitude ◽

Experimental Results ◽

Water Model ◽

Copper Converter ◽

Oscillation Modes

We investigated, experimentally and theoretically, the formation of slopping in a 1:5 scaled water model of a copper converter. The gas injected through submerged tuyeres in the copper converters results in slopping; the formation of standing waves. The high amplitude of the standing waves contributes to the premature wearing down of the converter's refractory lining. We present a methodology for controlling slopping by using two submerged tuyere lines. The combined lateral and bottom gas injection reduces the amplitude of the slopping by interfering with the oscillation modes of the surface wave. For a Froude number of 10 for both sets of tuyeres, the experimental results showed a 50% reduction in the amplitude of the surface wave in the water model.

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3.3 kV IGBT and diode chipset using lifetime control techniques and low-efficiency emitters

Facta universitatis - series Electronics and Energetics ◽

10.2298/fuee0201051n ◽

2002 ◽

Vol 15 (1) ◽

pp. 51-59

Author(s):

Mario Netzel ◽

Ralf Lerner ◽

Ralf Siemieniec ◽

Josef Lutz

Keyword(s):

Device Simulation ◽

Experimental Results ◽

Recombination Center ◽

Power Device ◽

Simulation Tools ◽

Control Techniques ◽

Recombination Model ◽

Good Accordance ◽

Low Efficiency ◽

Doping Profiles

The adjustment of emitter efficiency by variation of doping profiles or application of lifetime control techniques such as irradiation of electrons and helium are two generally recognized concepts for the improvement of power device characteristics. In this work both concepts were studied by use of device simulation for the development of an IGBT and freewheeling diode chipset for 3.3 kV. Simulations were performed using an extended recombination model and recombination center data taken from measurements at different irradiated devices. Finally, this lead to the manufacturing of an IGBT using low-emitter efficiency and an irradiated freewheeling diode. The experimental results are in good accordance with the previously performed simulations and give evidence of the capabilities of present device simulation tools.

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Inward Pumping in Mechanical Face Seals

Journal of Lubrication Technology ◽

10.1115/1.3554952 ◽

1969 ◽

Vol 91 (3) ◽

pp. 417-425 ◽

Cited By ~ 5

Author(s):

J. A. Findlay

Keyword(s):

Surface Wave ◽

Iterative Methods ◽

Reynolds Equation ◽

Hydrodynamic Lubrication ◽

Experimental Results ◽

Hydrodynamic Characteristics ◽

Face Seals

The hydrodynamic characteristics which produce inward pumping in mechanical face seals are studied. Solutions to Reynolds’ equation for hydrodynamic lubrication are obtained using both the short-bearing approximation and numerical iterative methods. It is found that pumping in face seals results from combined radial eccentricity and misalignment, or one circumferential surface wave. Experimental results confirm the theory.

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