Standing surface wave for anapole

The study of discharge performance was performed for argon, nitrogen, and the H2–C2H5OH gas mixture in a power range from 250 to 1000 W, and a pressure range from 10 to 1000 Pa. With argon, a surface wave at the plasma-quartz interface can be excited above 250 W. The surface wave modes can be identified as m=4 and m=6 with pressures of 10 and 230 Pa. With nitrogen, surface waves propagate in two or more modes superposed with a different value of m below the pressure of 133 Pa. In contrast to the above gases, the H2–C2H5OH gas mixture showed no surface wave generation for power levels up to 1000 W; only a hemisphere plasma with a diameter of 8 cm was observed just above the substrate. The plasma, having a diameter of 160 mm, is uniform below the pressure of 133 Pa in nitrogen discharges, but the plasma density is lower than in argon discharges. The radial distributions of electron density in the quartz tube also prove the existence of surface waves for argon and nitrogen. In addition, the axial distributions of electron density prove that the traveling and standing surface waves can be excited by argon discharges in each case: with or without the short plunger at the top of the setup.

Summary We present a frequency-domain analysis of travelling and standing surface waves on a smooth, laterally heterogeneous Earth model, using a potential representation that is valid everywhere, including in the neighbourhood of surface wave caustics. the Love and Rayleigh wave displacement fields are written in the form uL=k-1LW (-řX▿1)χL and uR=UřχR+k-1RV▿1χR; the quantities U, V and W are the local radial eigenfunctions, kL and kR are the local Love and Rayleigh wavenumbers, and χL and χR are surface wave potentials that vary rapidly on the surface of the unit sphere. the natural normalization condition for the local radial eigenfunctions is cCI1= 1, where c is the local phase velocity, C is the local group velocity and I1 is the local radial kinetic energy integral; with this normalization, the Love and Rayleigh wave potentials satisfy the spherical Helmholtz equations ▿21χL + k2LχL = 0 and ▿21χR + k2RχR = 0. Standing wave eigenfunctions χL and χR can be determined either by solving a truncated matrix eigenvalue problem or by using the EBK semi-classical method; the results incorporate multiplet coupling along a single dispersion branch but ignore cross-branch coupling. the theory allows for slowly varying topography of the Earth's surface and the core-mantle boundary, and incorporates the effect of self-gravitation.

A numerical investigation of the flow and heat and mass transfer during the growth of crystals by the floating-zone method in weightlessness using standing surface waves, created by applied vibration, and a stationary magnetic field has been carried out. With crystallization of silicon serving as the illustrative example, it is shown how, by selecting optimal parameters of the standing surface waves and of the magnetic field, one can appreciably (by severalfold) reduce the micro-and macrosegregation of the phosphorus impurity and grow a crystal with a uniformity that exceeds the best specimens obtained on the ground by the Czochralski method.

The Landau-Silin equation for spin waves in the conduction electron Fermi liquid is shown to give rise to a surface mode if the normal component of spin current is assumed to vanish at the surface. The new mode has an interesting one-way characteristic for propagation perpendicular to a surface-directed dc magnetic field. An experiment is proposed which may permit direct observation of the surface modes. Standing surface waves are suggested to be the cause of the anomalous dependence of experimental CESR lineshapes on dc magnetic field orientation.

This paper presents the results of theoretical and experimental investigations of second-order nonlinear interactions between standing surface waves on shallow water. The nonlinearity is introduced by the nonlinear terms in the Navier–Stokes equation and in the boundary conditions. The wave amplitudes are kept small enough for amplitude dispersion to be negligible, and the surface is treated as a resonantly driven, damped, harmonic oscillator. A pure first-order mode is excited by applying time periodic electrical stresses onto the free fluid surface, and this mode self-interacts to drive resonantly a second-order mode. The amplitudes are ultimately limited by dissipative processes in the fluid. These processes are taken into account in the theory, and the experimental results justify the assumptions made. Wave amplitudes could be monitored to a spatial resolution of 5 × 10−4 cm by an optical technique.

It has been established that, in the case where a standing surface wave acts on a thermocapillary-convection flow in a cylindrical volume, there arises an oscillating-convection zone between the laminar and turbulent regimes of flow. It is shown that the boundary between these regimes is determined by the amplitude δ and the number of periods n of the standing wave and is practically independent of the Marangoni number and the oscillation frequency of this wave. At n = 2, in the range 0.004 < δ < 0.006, the parameters of the fluid cease to oscillate. The mechanisms by which the thermocapillary convection in closed volumes loses its stability are discussed.

By depositing a thin film on a substrate in which a standing surface wave is excited, we fabricated a phase grating in which variations in the film thickness as well as the refractive index occurred at half the wavelength of the surface acoustic waves. As no such phenomenon has been reported until now, its application for optical elements is expected.

We examine the linear stability of a planar, alloy thin film, growing by a deposition flux from the vapor. The stability of the film surface is influenced by stresses generated by both compositional inhomogeneity, via a composition dependent lattice parameter, and lattice mismatch between the film and substrate. The stress generated by the compositional inhomogeneities, which accompany nonplanar interfacial morphologies, can be either stabilizing or destabilizing. Under certain conditions, a growing planar film under tensile misfit-strain can be stable, whereas a growing film under the same magnitude of compressive strain can be unstable. These compositionally generated stresses can also lead to traveling or standing surface waves and unstable planar surfaces in lattice matched films. All of these instabilities can develop via the deposition process itself; the wave number dependence of the instability is different, however, from that in the pure surface diffusion limit. We also compare our results with numerous experimental observations. \textcopyright{} 1996 The American Physical Society.

We study the conditions for the occurrence of "the voice of the sea" in the infrasound range can occur and determine its parameters from infrasound measurements in the Black Sea water area conducted in 2011 and 2016 and in the water area of the Sea of Okhotsk in 2017. To this end, we compared the observations of different parameters (mean correlation, spectra of acoustic arrivals, direction and phase velocity) of the high-frequency infrasound (1–10 Hz), recorded in Katsiveli (Crimea) in 2011 and 2016. We performed a detailed study of the wind conditions in the Black Sea water area during the measurement period, as well as the conditions for the propagation of acoustic waves along the direction of their arrivals.&#x0D; In both cases the atmospheric vortices in the direction of the arrival of infrasound were detected, which caused changes in wind velocity vector above the sea surface. The infrasound recorded in 2011 was caused by the interaction of two differently rotating atmospheric vortices over the sea. In 2016, a vortex was observed to the West from the registration point. The possibility of generating "the voice of the sea" due to the rotation of the wind velocity, which causes a nonlinear interaction of surface waves propagating in opposite directions to each other, and the formation of their 2nd harmonic in the form of a standing surface wave is discussed.&#x0D; From the analysis of the wind speed and wind direction profiles along the infrasound arrival path, as well as the acoustic pressure fields calculated by the parabolic equation method for the effective sound speed profiles in the direction of infrasound propagation, the most probable areas of infrasound generation were determined. In both cases these areas coincided with the zones in which the wind speed drops to zero, and the direction of the wind changes to the opposite.&#x0D; An example of simultaneous detection from one direction of the microbaroms with frequencies 0.2–0.3 Hz and "the voice of the sea" with a higher frequency of 5.5 Hz is given.

Conditions for the occurrence of the “voice of the sea” within the infrasonic range are studied and its parameters are determined from measurements performed in the waters of the Black Sea (2011 and 2016) and the Sea of Okhotsk (2017). Different parameters (mean correlations, acoustic-arrival spectra, directions, and phase velocities) of high-frequency infrasounds (1–10 Hz) recorded during the 2011 and 2016 experiments carried out in Katsiveli (Crimea) are compared. Wind conditions over the Black Sea waters and the conditions of propagation of acoustic waves along the direction of their arrivals during these measurements have been studied in detail. In both cases, atmospheric vortices are observed in the direction of infrasound arrivals, which cause the wind to change its direction over the sea surface. The interaction between two oppositely directed atmospheric vortices (according to data obtained in 2011) and a vortex observed to the west of the recording point (according to data obtained in 2016) result in the generation of infrasounds. The generation of microbaroms and the voice of the sea due to wind-direction variations, which cause the nonlinear interaction of surface waves propagating in opposite directions and the formation of their 2nd harmonics in the form of standing surface waves, is discussed. The most probable regions of infrasound generation are determined from an analysis of the profiles of wind velocity and direction along the path of infrasound arrivals and acoustic-pressure fields calculated using the parabolic-equation method according to the $${{C}_{{{\text{eff}}}}}$$ profiles in the direction of infrasound propagation. In both cases, these regions coincide with zones in which the wind velocity had dropped to zero and the wind direction had reversed. The infrasound within a microbarom frequency range of 0.2–0.3 Hz and the (higher frequency) sea voice with a mean frequency of 5.5 Hz, which were simultaneously recorded from the same direction, are given as an example.

Building on a previous study that analyzed standing surface waves in magnetic slabs embedded in a non-magnetic external environment, in this study the model is generalized and external magnetic fields are added. The slab is assumed to be thin, with weak magnetic asymmetry. The frequencies of the standing harmonic modes are derived to leading order in the small quantities representing the thin slab width and the weak asymmetry. It is found that the frequencies are more sensitive to changes to the width of the slab than changes in the magnetic asymmetry. The frequency ratio of the first harmonic to the fundamental mode is derived, along with the amplitude difference between the two sides of the slab, as these may be observable quantities that can be compared with observational results and applied to carry out solar magnetoseismology.

10 - The Two-Port SAW Resonator

Tools that are capable of manipulating micro-sized objects have been widely used in such fields as physics, chemistry, biology, and medicine. Several devices, including optical tweezers, atomic force microscope, micro-pipette aspirator, and standing surface wave type acoustic tweezers have been studied to satisfy this need. However, none of them has been demonstrated to be suitable for in vivo and clinical studies. Single beam acoustic tweezers (SBAT) is a technology that uses highly focused acoustic beam to trap particles toward the beam focus. Its feasibility was first theoretically and experimentally demonstrated by Lee and Shung several years ago. Since then, much effort has been devoted to improving this technology. At present, the tool is capable of trapping a microparticle as small as 1 μm, as well as a single red blood cell. Although in comparing to other microparticles manipulating technologies, SBAT has advantages of providing stronger trapping force and deeper penetration depth in tissues, and producing less tissue damage, its potential for in vivo applications has yet been explored. It is worth noting that ultrasound has been used as a diagnostic tool for over 50 years and no known major adverse effects have been observed at the diagnostic energy level. This paper reports the results of an initial attempt to assess the feasibility of single beam acoustic tweezers to trap microparticles in vivo inside of a blood vessel. The acoustic intensity of SBAT under the trapping conditions that were utilized was measured. The mechanical index and thermal index at the focus of acoustic beam were found to be 0.48 and 0.044, respectively, which meet the standard of commercial diagnostic ultrasound system.

28p-J-3 Lagrangian Turbulence in Three-Dimensional Standing Surface Waves