Complex (dusty) plasmas consist of micron sized microparticles immersed into ordinary ion-electron plasmas. They can exist in solid, liquid or gaseous states and exhibit a range of dynamic phenomena such as linear and nonlinear dust waves, solitons, shocks, Mach cones, heat transfer by phonons, flows, etc. We report on the experimental and numerical study of dissipative solitons in complex plas...

It is known that marine sediments can support both compressional and shear waves. However, published work on scattering from irregular elastic media has not examined the influence of shear on sea bed scattering in detail. A perturbation model previously developed by the authors for joint roughness-volume scattering is used to study the effects of elasticity for three sea bed types: sedimentary ...

We examine spectral time series of coronal line Mg ix 368 Å and transition region line O v 629 Å, observed with the Coronal Diagnostic Spectrometer (CDS) onboard the SOHO spacecraft. Primarily we were looking for intensity and velocity oscillations in polar plumes, however by chance we detected a giant macro-spicule at the limb and were able to follow its dynamical structure. Blue and red-shift...

S U M M A R Y Seismic tomography has been one of the primary tools to image the interior of the earth and other elastic structures. To date the inversions of compressional (P) and shear (S) wave speeds have been carried out separately under the assumption that P traveltimes are affected only by the P wave speed of the elastic media and S traveltimes by the S wave speed. Using numerical and anal...

If a large amplitude density pulse is launched into a plasma having equal electron and ion temperatures, Te 5Ti , Landau damping prevents the formation of a sharp leading edge ~‘‘shock’’! and the pulse spreads out. If the Landau damping is eliminated, the pulse steepens as it propagates and a shock structure is formed. This has been observed experimentally, for example, by increasing the Te /Ti...

High-energy X-ray scattering (90 keV) has been performed at the high-energy beamline ID15 at the European Synchrotron Radiation Facility, Grenoble, on perfect Si crystals excited by compressional ultrasound waves in the [111] direction. Two-dimensional intensity maps of the 351 Bragg peak reveal a purely longitudinal distortion of the lattice with respect to the applied distortion field, which ...

Wavefront healing, in which diffractions interfere with directly traveling waves causing a reduction in recorded traveltime delays, has been postulated to cause a bias towards faster estimated Earth models. This paper reviews the theory from the mathematical physics community that explains the properties of diffractions and applies it to a suite of increasingly complicated numerical examples. W...

We investigate the nature of nonlinear waves propagating transverse to the magnetic field in a bi-ion plasma including plasma pressure. By using the conservation laws derived from the multi-ion fluid equations the system may be described by a single order differential equation whose properties control the structure of the flow and the magnetic field. Compressive solitons exist in specific range...

Recently developed new transducers for ultrasonic transmission, which can be embedded right into concrete, are now used for non-destructive permanent monitoring of concrete. They can be installed during construction or thereafter. Large volumes of concrete can be monitored for changes of material properties by a limited number of transducers. The transducer design, the main properties as well a...

Earth's solid inner core is surrounded by a convecting liquid outer core, creating the geodynamo driving the planet's magnetic field. Seismic studies using compressional body waves suggest hemispherical variation in the anisotropic structure of the inner core, but are poorly constrained because of limited earthquake and receiver distribution. Here, using normal mode splitting function measureme...