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F G Mitri - One of the best experts on this subject based on the ideXlab platform.
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axial acoustic radiation force on rigid oblate and prolate spheroids in bessel vortex beams of progressive Standing and quasi Standing Waves
Ultrasonics, 2017Co-Authors: F G MitriAbstract:The analysis using the partial-wave series expansion (PWSE) method in spherical coordinates is extended to evaluate the acoustic radiation force experienced by rigid oblate and prolate spheroids centered on the axis of wave propagation of high-order Bessel vortex beams composed of progressive, Standing and quasi-Standing Waves, respectively. A coupled system of linear equations is derived after applying the Neumann boundary condition for an immovable surface in a non-viscous fluid, and solved numerically by matrix inversion after performing a single numerical integration procedure. The system of linear equations depends on the partial-wave index n and the order of the Bessel vortex beam m using truncated but converging PWSEs in the least-squares sense. Numerical results for the radiation force function, which is the radiation force per unit energy density and unit cross-sectional surface, are computed with particular emphasis on the amplitude ratio describing the transition from the progressive to the pure Standing Waves cases, the aspect ratio (i.e., the ratio of the major axis over the minor axis of the spheroid), the half-cone angle and order of the Bessel vortex beam, as well as the dimensionless size parameter. A generalized expression for the radiation force function is derived for cases encompassing the progressive, Standing and quasi-Standing Waves of Bessel vortex beams. This expression can be reduced to other types of beams/Waves such as the zeroth-order Bessel non-vortex beam or the infinite plane wave case by appropriate selection of the beam parameters. The results for progressive Waves reveal a tractor beam behavior, characterized by the emergence of an attractive pulling force acting in opposite direction of wave propagation. Moreover, the transition to the quasi-Standing and pure Standing wave cases shows the acoustical tweezers behavior in dual-beam Bessel vortex beams. Applications in acoustic levitation, particle manipulation and acousto-fluidics would benefit from the results of the present investigation.
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radiation forces and torque on a rigid elliptical cylinder in acoustical plane progressive and quasi Standing Waves with arbitrary incidence
Physics of Fluids, 2016Co-Authors: F G MitriAbstract:This paper presents two key contributions; the first concerns the development of analytical expressions for the axial and transverse acoustic radiation forces exerted on a 2D rigid elliptical cylinder placed in the field of plane progressive, quasi-Standing, or Standing Waves with arbitrary incidence. The second emphasis is on the acoustic radiation torque per length. The rigid elliptical cylinder case is important to be considered as a first-order approximation of the behavior of a cylindrical fluid column trapped in air because of the significant acoustic impedance mismatch at the particle boundary. Based on the rigorous partial-wave series expansion method in cylindrical coordinates, non-dimensional acoustic radiation force and torque functions are derived and defined in terms of the scattering coefficients of the elliptic cylinder. A coupled system of linear equations is obtained after applying the Neumann boundary condition for an immovable surface in a non-viscous fluid and solved numerically by matrix inversion after performing a single numerical integration procedure. Computational results for the non-dimensional force components and torque, showing the transition from the progressive to the (equi-amplitude) Standing wave behavior, are performed with particular emphasis on the aspect ratio a/b, where a and b are the semi-axes of the ellipse, the dimensionless size parameter, as well as the angle of incidence ranging from end-on to broadside incidence. The results show that the elliptical geometry has a direct influence on the radiation force and torque, so that the standard theory for circular cylinders (at normal incidence) leads to significant miscalculations when the cylinder cross section becomes non-circular. Moreover, the elliptical cylinder experiences, in addition to the acoustic radiation force, a radiation torque that vanishes for the circular cylinder case. The application of the formalism presented here may be extended to other 2D surfaces of arbitrary shape, such as Chebyshev cylindrical particles with a small deformation, stadiums (with oval shape), or other non-circular geometries.
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radiation forces and torque on a rigid elliptical cylinder in acoustical plane progressive and quasi Standing Waves with arbitrary incidence
arXiv: Classical Physics, 2016Co-Authors: F G MitriAbstract:Analytical expressions for the axial and transverse acoustic radiation forces as well as the radiation torque per length are derived for a rigid elliptical cylinder placed arbitrarily in the field of in plane progressive, quasi-Standing or Standing Waves. The rigid elliptical cylinder case is important to be considered as a first-order approximation of the behavior of a fluid particle suspended in air, because of the significant acoustic impedance mismatch at the particle's boundary. Based on the partial-wave series expansion method in cylindrical coordinates, non-dimensional acoustic radiation force and torque functions are derived and defined in terms of the scattering coefficients of the elliptic cylinder. A coupled system of linear equations is obtained after applying the Neumann boundary condition for an immovable surface in a non-viscous fluid, and solved numerically by matrix inversion after performing a single numerical integration procedure. Computational results for the non-dimensional force components and torque, showing the transition from the progressive to the (equi-amplitude) Standing wave behavior, are performed with particular emphasis on the aspect ratio a/b, where a and b are the semi-axes of the ellipse, the dimensionless size parameter, as well as the angle of incidence ranging from end-on to broadside incidence. The results show that the elliptical geometry has a direct influence on the radiation force and torque, so that the standard theory for circular cylinders (at normal incidence) leads to significant miscalculations when the cylinder cross-section becomes non-circular. Moreover, the elliptical cylinder experiences, in addition to the acoustic radiation force, a radiation torque that vanishes for the circular cylinder case. The application of the formalism presented here may be extended to other 2D surfaces of arbitrary shape.
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acoustic radiation force on an air bubble and soft fluid spheres in ideal liquids example of a high order bessel beam of quasi Standing Waves
European Physical Journal E, 2009Co-Authors: F G MitriAbstract:The partial wave series for the scattering of a high-order Bessel beam (HOBB) of acoustic quasi-Standing Waves by an air bubble and fluid spheres immersed in water and centered on the axis of the beam is applied to the calculation of the acoustic radiation force. A HOBB refers to a type of beam having an axial amplitude null and an azimuthal phase gradient. Radiation force examples obtained through numerical evaluation of the radiation force function are computed for an air bubble, a hexane, a red blood and mercury fluid spheres in water. The examples were selected to illustrate conditions having progressive, Standing and quasi-Standing Waves with appropriate selection of the Waves’ amplitude ratio. An especially noteworthy result is the lack of a specific vibrational mode contribution to the radiation force determined by appropriate selection of the HOBB parameters.
Philippe Jonnard - One of the best experts on this subject based on the ideXlab platform.
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x ray fluorescence induced by Standing Waves in the grazing incidence and grazing exit modes study of the mg co zr system
arXiv: Materials Science, 2015Co-Authors: Yanyan Yuan, Karine Le Guen, Jeanmichel Andre, Jingtao Zhu, Zhanshan Wang, Francoise Bridou, Angelo Giglia, Philippe JonnardAbstract:We present the characterization of Mg-Co-Zr tri-layer stacks by using x-ray fluorescence induced by x-ray Standing Waves, both in the grazing incidence (GI) and grazing exit (GE) modes. The introduction of a slit in the direction of the detector improves the angular resolution by a factor 2 and significantly the sensitivity of the technique for the chemical characterization of the buried interfaces. By observing the intensity variations of the Mg Kalpha and Co Lalpha characteristic emissions as a function of the incident (GI mode) or detection (GE mode) angle, we show that the interfaces of the Si/[Mg/Co/Zr] x30 multilayer are abrupt, whereas in the Si/[Mg/Zr/Co] x30 multilayer a strong intermixing occurs at the Co-on-Zr interfaces. The explanation of this opposite behaviour of the Co-on-Zr and Zr-on-Co interfacesis given by the calculation of the mixing enthalpies of the Co-Mg, Co-Zr and Mg-Zr systems, which shows that the Co-Zr system presents anegative value and the two others positive values. Together with the difference of the surface free energies of Zr and Co, this leads us to consider the Mg/Zr/Co system as aMg/Co x Zr y bi-layer stack, with x/y estimated around 3.5.
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x ray fluorescence induced by Standing Waves in the grazing incidence and grazing exit modes study of the mg co zr system
Journal of Synchrotron Radiation, 2015Co-Authors: Yanyan Yuan, Karine Le Guen, Jeanmichel Andre, Jingtao Zhu, Zhanshan Wang, Francoise Bridou, Angelo Giglia, Philippe JonnardAbstract:The characterization of Mg-Co-Zr tri-layer stacks using X-ray fluorescence induced by X-ray Standing Waves, in both the grazing-incidence (GI) and the grazing-exit (GE) modes, is presented. The introduction of a slit in the direction of the detector improves the angular resolution by a factor of two and significantly improves the sensitivity of the technique for the chemical characterization of the buried interfaces. By observing the intensity variations of the Mg Kα and Co Lα characteristic emissions as a function of the incident (GI mode) or detection (GE mode) angle, it is shown that the interfaces of the Si/[Mg/Co/Zr] × 30 multilayer are abrupt, whereas in the Si/[Mg/Zr/Co] × 30 multilayer a strong intermixing occurs at the Co-on-Zr interfaces. An explanation of this opposite behavior of the Co-on-Zr and Zr-on-Co interfaces is given by the calculation of the mixing enthalpies of the Co-Mg, Co-Zr and Mg-Zr systems, which shows that the Co-Zr system presents a negative value and the other two systems present positive values. Together with the difference of the surface free energies of Zr and Co, this leads to the Mg/Zr/Co system being considered as a Mg/CoxZry bi-layer stack, with x/y estimated around 3.5.
Yanyan Yuan - One of the best experts on this subject based on the ideXlab platform.
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x ray fluorescence induced by Standing Waves in the grazing incidence and grazing exit modes study of the mg co zr system
arXiv: Materials Science, 2015Co-Authors: Yanyan Yuan, Karine Le Guen, Jeanmichel Andre, Jingtao Zhu, Zhanshan Wang, Francoise Bridou, Angelo Giglia, Philippe JonnardAbstract:We present the characterization of Mg-Co-Zr tri-layer stacks by using x-ray fluorescence induced by x-ray Standing Waves, both in the grazing incidence (GI) and grazing exit (GE) modes. The introduction of a slit in the direction of the detector improves the angular resolution by a factor 2 and significantly the sensitivity of the technique for the chemical characterization of the buried interfaces. By observing the intensity variations of the Mg Kalpha and Co Lalpha characteristic emissions as a function of the incident (GI mode) or detection (GE mode) angle, we show that the interfaces of the Si/[Mg/Co/Zr] x30 multilayer are abrupt, whereas in the Si/[Mg/Zr/Co] x30 multilayer a strong intermixing occurs at the Co-on-Zr interfaces. The explanation of this opposite behaviour of the Co-on-Zr and Zr-on-Co interfacesis given by the calculation of the mixing enthalpies of the Co-Mg, Co-Zr and Mg-Zr systems, which shows that the Co-Zr system presents anegative value and the two others positive values. Together with the difference of the surface free energies of Zr and Co, this leads us to consider the Mg/Zr/Co system as aMg/Co x Zr y bi-layer stack, with x/y estimated around 3.5.
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x ray fluorescence induced by Standing Waves in the grazing incidence and grazing exit modes study of the mg co zr system
Journal of Synchrotron Radiation, 2015Co-Authors: Yanyan Yuan, Karine Le Guen, Jeanmichel Andre, Jingtao Zhu, Zhanshan Wang, Francoise Bridou, Angelo Giglia, Philippe JonnardAbstract:The characterization of Mg-Co-Zr tri-layer stacks using X-ray fluorescence induced by X-ray Standing Waves, in both the grazing-incidence (GI) and the grazing-exit (GE) modes, is presented. The introduction of a slit in the direction of the detector improves the angular resolution by a factor of two and significantly improves the sensitivity of the technique for the chemical characterization of the buried interfaces. By observing the intensity variations of the Mg Kα and Co Lα characteristic emissions as a function of the incident (GI mode) or detection (GE mode) angle, it is shown that the interfaces of the Si/[Mg/Co/Zr] × 30 multilayer are abrupt, whereas in the Si/[Mg/Zr/Co] × 30 multilayer a strong intermixing occurs at the Co-on-Zr interfaces. An explanation of this opposite behavior of the Co-on-Zr and Zr-on-Co interfaces is given by the calculation of the mixing enthalpies of the Co-Mg, Co-Zr and Mg-Zr systems, which shows that the Co-Zr system presents a negative value and the other two systems present positive values. Together with the difference of the surface free energies of Zr and Co, this leads to the Mg/Zr/Co system being considered as a Mg/CoxZry bi-layer stack, with x/y estimated around 3.5.
S.s. Wong - One of the best experts on this subject based on the ideXlab platform.
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a 10 ghz global clock distribution using coupled Standing wave oscillators
IEEE Journal of Solid-state Circuits, 2003Co-Authors: Frank Omahony, Mark Horowitz, S.s. WongAbstract:In this paper, a global clock network that incorporates Standing Waves and coupled oscillators to distribute a high-frequency clock signal with low skew and low jitter is described. The key design issues involved in generating Standing Waves on a chip are discussed, including minimizing wire loss within an available technology. A Standing-wave oscillator, which is a distributed oscillator that sustains ideal Standing Waves on lossy wires, is introduced. A clock grid architecture comprised of coupled Standing-wave oscillators and differential low-swing clock buffers is presented, along with a compact circuit model for networks of oscillators. The measured results for a prototyped Standing-wave clock grid operating at 10 GHz and fabricated in a 0.18-/spl mu/m 6M CMOS logic process are presented. A technique is proposed for on-chip skew measurements with subpicosecond precision.
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design of a 10ghz clock distribution network using coupled Standing wave oscillators
Design Automation Conference, 2003Co-Authors: Frank Omahony, Mark Horowitz, C P Yue, S.s. WongAbstract:In this paper, a global clock network that incorporates Standing Waves and coupled oscillators to distribute a high-frequency clock signal with low skew and low jitter is described. The key design issues involved in generating Standing Waves on a chip are discussed, including minimizing wire loss within an available technology. A Standing-wave oscillator, a distributed oscillator that sustains ideal Standing Waves on lossy wires, is introduced. A clock grid architecture comprised of coupled, Standing-wave oscillators and differential, low-swing clock buffers is presented. The measured results for a prototyped Standing-wave clock grid operating at 10GHz and fabricated in a 0.18/spl mu/m 6M CMOS logic process are presented. A technique is proposed for on-chip skew measurements with subpicosecond precision.
Zhanshan Wang - One of the best experts on this subject based on the ideXlab platform.
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x ray fluorescence induced by Standing Waves in the grazing incidence and grazing exit modes study of the mg co zr system
arXiv: Materials Science, 2015Co-Authors: Yanyan Yuan, Karine Le Guen, Jeanmichel Andre, Jingtao Zhu, Zhanshan Wang, Francoise Bridou, Angelo Giglia, Philippe JonnardAbstract:We present the characterization of Mg-Co-Zr tri-layer stacks by using x-ray fluorescence induced by x-ray Standing Waves, both in the grazing incidence (GI) and grazing exit (GE) modes. The introduction of a slit in the direction of the detector improves the angular resolution by a factor 2 and significantly the sensitivity of the technique for the chemical characterization of the buried interfaces. By observing the intensity variations of the Mg Kalpha and Co Lalpha characteristic emissions as a function of the incident (GI mode) or detection (GE mode) angle, we show that the interfaces of the Si/[Mg/Co/Zr] x30 multilayer are abrupt, whereas in the Si/[Mg/Zr/Co] x30 multilayer a strong intermixing occurs at the Co-on-Zr interfaces. The explanation of this opposite behaviour of the Co-on-Zr and Zr-on-Co interfacesis given by the calculation of the mixing enthalpies of the Co-Mg, Co-Zr and Mg-Zr systems, which shows that the Co-Zr system presents anegative value and the two others positive values. Together with the difference of the surface free energies of Zr and Co, this leads us to consider the Mg/Zr/Co system as aMg/Co x Zr y bi-layer stack, with x/y estimated around 3.5.
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x ray fluorescence induced by Standing Waves in the grazing incidence and grazing exit modes study of the mg co zr system
Journal of Synchrotron Radiation, 2015Co-Authors: Yanyan Yuan, Karine Le Guen, Jeanmichel Andre, Jingtao Zhu, Zhanshan Wang, Francoise Bridou, Angelo Giglia, Philippe JonnardAbstract:The characterization of Mg-Co-Zr tri-layer stacks using X-ray fluorescence induced by X-ray Standing Waves, in both the grazing-incidence (GI) and the grazing-exit (GE) modes, is presented. The introduction of a slit in the direction of the detector improves the angular resolution by a factor of two and significantly improves the sensitivity of the technique for the chemical characterization of the buried interfaces. By observing the intensity variations of the Mg Kα and Co Lα characteristic emissions as a function of the incident (GI mode) or detection (GE mode) angle, it is shown that the interfaces of the Si/[Mg/Co/Zr] × 30 multilayer are abrupt, whereas in the Si/[Mg/Zr/Co] × 30 multilayer a strong intermixing occurs at the Co-on-Zr interfaces. An explanation of this opposite behavior of the Co-on-Zr and Zr-on-Co interfaces is given by the calculation of the mixing enthalpies of the Co-Mg, Co-Zr and Mg-Zr systems, which shows that the Co-Zr system presents a negative value and the other two systems present positive values. Together with the difference of the surface free energies of Zr and Co, this leads to the Mg/Zr/Co system being considered as a Mg/CoxZry bi-layer stack, with x/y estimated around 3.5.
