High-frequency mode conversion technique for stiff lesion detection with magnetic resonance elastography (MRE)

A structure-dependent integration method may experience an unusual overshooting behavior in the steady-state response of a high frequency mode. In order to explore this unusual overshooting behavior, a local truncation error is established from a forced vibration response rather than a free vibration response. As a result, this local truncation error can reveal the root cause of the inaccurate integration of the steady-state response of a high frequency mode. In addition, it generates a loading correction scheme to overcome this unusual overshooting behavior by means of the adjustment the difference equation for displacement. Apparently, these analytical results are applicable to a general structure-dependent integration method.

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High Frequency Mode in New Antiferroelectric Mixture

Molecular Crystals and Liquid Crystals ◽

10.1080/15421401003795969 ◽

2010 ◽

Vol 525 (1) ◽

pp. 50-56 ◽

Cited By ~ 13

Author(s):

P. Perkowski ◽

K. Ogrodnik ◽

W. Piecek ◽

Z. Raszewski ◽

M. Żurowska ◽

...

Keyword(s):

High Frequency ◽

Frequency Mode ◽

High Frequency Mode

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SQUEEZING EFFECTS IN THE SUM AND DIFFERENCE OF THE FIELD AMPLITUDE IN THE RAMAN PROCESS

Modern Physics Letters B ◽

10.1142/s0217984905009146 ◽

2005 ◽

Vol 19 (25) ◽

pp. 1261-1276 ◽

Cited By ~ 3

Author(s):

DILIP KUMAR GIRI ◽

P. S. GUPTA

Keyword(s):

High Frequency ◽

Higher Order ◽

The State ◽

Field Amplitude ◽

Frequency Mode ◽

Difference Frequency ◽

Field Mode ◽

High Frequency Mode ◽

Frequency Field ◽

Raman Process

Sum and difference squeezing of the field amplitude are higher-order squeezing effects. These effects are studied in the Raman process under the short-time approximation based on a fully quantum mechanical approach. It is shown that for uncorrelated modes, the normal squeezing in the sum and difference-frequency field depends on the sum and difference squeezing of input field modes respectively, which can generate normal squeezing in the sum and difference-frequency field mode. All the possibilities for obtaining sum and difference squeezing in two modes and its dependence on squeezing of individual field modes are investigated. We have also shown that if the high-frequency mode is in a coherent state and the low-frequency mode is squeezed, the field state will be difference squeezed if the amplitude of the high-frequency mode is large enough; otherwise the state may or may not be difference squeezed. If both modes are squeezed, then the state may or may not be difference squeezed. These higher-order squeezing effects are useful in the production of squeezing in the Raman process.

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Investigation of Flow Around a Slender Body at High Angles of Attack

Journal of King Abdulaziz University-Engineering Sciences ◽

10.4197/eng.30-1.4 ◽

2019 ◽

Vol 30 (1) ◽

pp. 51-61

Author(s):

Ibraheem AlQadi Ibraheem AlQadi

Keyword(s):

High Frequency ◽

Low Frequency ◽

The Body ◽

Slender Body ◽

Frequency Mode ◽

Dynamic Mode ◽

High Frequency Mode ◽

Wide Range ◽

Low Frequency Mode ◽

High Angles Of Attack

A numerical investigation of flow around a slender body at high angles of attack is presented. Large eddy simulation of the flow around an ogive-cylinder body at high angles of attack is carried out. Asymmetric vortex flow was observed at angles of attack of α = 55◦ and 65◦ . The results showed that the phenomenon is present in the absence of artificial geometrical or flow perturbation. Contrary to the accepted notion that flow asymmetry is due to a convective instability, the development of vortex asymmetry in the absence of perturbations indicates the existence of absolute instability. An investigation of the unsteady flow field was carried out using dynamic mode decomposition. The analysis identified two distinct unsteady modes; high-frequency mode and low-frequency mode. At angle of attack 45◦ the high-frequency mode is dominant in the frontal part of the body and the low-frequency mode is dominant at the rear part. At α = 55◦ , the highfrequency mode is dominant downstream of vortex breakdown. At α = 65◦ , the spectrum shows a wide range of modes. Reconstruction of the dynamical modes shows that the low-frequency mode is associated with the unsteady wake and the high-frequency mode is associated with unsteady shear layer.

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