THEORETICAL AND EXPERIMENTAL INVESTIGATIONS OF HARMONIC ION CYCLOTRON WAVE PROPAGATION AND PLASMA HEATING. Final Report.

Adhesively bonded joints are widely used in many branches of industry. Mechanical degradation of this type of connections does not have significant symptoms that can be noticed during visual assessment, so non-destructive testing becomes a very important issue. The paper deals with experimental investigations of adhesively bonded steel plates with different defects. Five samples (an intact one and four with damages in the form of partial debonding) were prepared. The inspection was conducted with the use of guided wave propagation method. Lamb waves were excited at one point of the sample, whereas the out-of-plane velocity signals were recorded in a number of points spread over the area of overlap. The processing of signals consisted of calculations of weighted root mean square (WRMS). The results of the analysis showed that the WRMS maps allow for identification and determination of size and shape of debonding areas.

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On the nature of the microwave field emerging from a composite pupil

Modern Physics Letters B ◽

10.1142/s0217984920502474 ◽

2020 ◽

Vol 34 (24) ◽

pp. 2050247

Author(s):

Ilaria Cacciari ◽

Daniela Mugnai ◽

Anedio Ranfagni

Keyword(s):

Wave Propagation ◽

Stochastic Model ◽

Radio Frequency ◽

Delay Time ◽

Microwave Field ◽

Near Field ◽

Phase Variation ◽

Experimental Investigations ◽

Frequency Signal ◽

Made In

Further experimental investigations in the microwave field emerging from a composite pupil are reported in order to determine the nature of the wave propagation. The experiments consisted of delay-time measurements as a function of the distance of the detector from the pupil under test, as well as of the phase variation of a radio-frequency signal at 35 MHz that modulated the same microwave carrier at 9.33 GHz. In addition, measurements employing an admittance comparator were made in order to determine the character of the propagation impedance. All results obtained confirmed superluminal behavior in the near field, up to a distance of about 40 cm. These results were then interpreted within the framework of a stochastic model.

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Conception of ion cyclotron plasma heating in the Globus-M2 spherical tokamak

Technical Physics Letters ◽

10.1134/s1063785012100100 ◽

2012 ◽

Vol 38 (10) ◽

pp. 869-872 ◽

Cited By ~ 4

Author(s):

O. N. Shcherbinin ◽

V. V. D’yachenko ◽

V. K. Gusev ◽

V. I. Varfolomeev ◽

Yu. V. Petrov ◽

...

Keyword(s):

Plasma Heating ◽

Spherical Tokamak ◽

Ion Cyclotron

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Hydromagnetic Wave Propagation near Ion Cyclotron Resonance

The Physics of Fluids ◽

10.1063/1.1706848 ◽

1963 ◽

Vol 6 (7) ◽

pp. 925 ◽

Cited By ~ 11

Author(s):

Forrest I. Boley ◽

John M. Wilcox ◽

Alan W. DeSilva ◽

Peter R. Forman ◽

Gordon W. Hamilton ◽

...

Keyword(s):

Wave Propagation ◽

Cyclotron Resonance ◽

Ion Cyclotron Resonance ◽

Hydromagnetic Wave ◽

Ion Cyclotron

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PROPAGATION OF LOCALIZED VIBRATION MODES ALONG EDGES OF IMMERSED WEDGE-LIKE STRUCTURES: GEOMETRICAL-ACOUSTICS APPROACH

Journal of Computational Acoustics ◽

10.1142/s0218396x99000060 ◽

1999 ◽

Vol 07 (01) ◽

pp. 59-70 ◽

Cited By ~ 2

Author(s):

VICTOR V. KRYLOV

Keyword(s):

Wave Propagation ◽

Acoustic Waves ◽

Nonlinear Function ◽

Experimental Investigations ◽

Elastic Plates ◽

Liquid Loading ◽

Geometrical Acoustics ◽

Subsonic Regime ◽

Supersonic Regime ◽

Elastic Modes

The theory of antisymmetric localized elastic modes propagating along edges of immersed wedge-like structures is developed using the geometrical-acoustics approach to the description of flexural waves in elastic plates of variable thickness. The velocities of these modes, often called wedge acoustic waves, are calculated using solutions of the dispersion equation of the Bohr-Sommerfeld type following from the geometrical-acoustics description of localized wedge modes. In a subsonic regime of wave propagation, i.e. for wedge modes slower than sound in liquid, the influence of liquid loading results in significant decrease of wedge wave velocities in comparison with their values in vacuum. This decrease is a nonlinear function of a wedge apex angle θ and is more pronounced for small values of θ. In a supersonic regime of wedge wave propagation, a smaller decrease in velocities takes place and the waves travel with the attenuation due to radiation of sound into the surrounding liquid. The comparison is given with the recent experimental investigations of wedge waves carried out by independent researchers.

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