Fully quantum treatment explicitly presents the high harmonic generation as a three-step process: (i) above threshold ionization (ATI) is followed by (ii) electron propagation in a laser-dressed continuum. Subsequently (iii) stimulated (or laser assisted) recombination brings the electron back into the initial state with emission of a high-energy photon. Contributions of all ATI channels add up...

We report experimental measurements on the rheology of a dry granular material under a weak level of vibration generated by sound injection. First, we measure the drag force exerted on a wire moving in the bulk. We show that when the driving vibration energy is increased, the effective rheology changes drastically: going from a non-linear dynamical friction behavior --weakly increasing with the...

This paper contains investigations on the behavior of five artificial rocklike materials subjected to abrasive water jet cutting. The influence of the test parameters, i.e. applied pump pressure, traverse rate and abrasive mass flow rate was investigated, as well as the influence of several material parameters, e.g. compressive strength, Young's modulus, absorbed fracture energy and crack veloc...

While the threshold of splashing when liquid droplets impact against rigid solid surfaces is known to be related to the Weber number (We), the effect of ambient gas pressure (or density) and the impact angle have not been systematically studied. In this study, we examine the effects of droplet velocity, impact angle, and ambient gas pressure (or density) on the threshold of splashing. In our me...

A theory of vocal fold oscillation is developed on the basis of the body-cover hypothesis. The cover is represented by a distributed surface layer that can propagate a mucosal surface wave. Linearization of the surface-wave displacement and velocity, and further small-amplitude approximations, yields closed-form expressions for conditions of oscillation. The theory predicts that the lung pressu...

Rigid blade coating of glass plates by oil-in-water emulsions stabilized by surfactants is studied. Complete surface coverage is obtained only for speeds exceeding a threshold velocity dependent on the height between the blade end and the surface. Below this threshold, the emulsion can be inverted in the vicinity of the blade. The inversion dynamics of the oil-in-water emulsion and the depositi...

Magnetic fluctuations are recognized in a large variety of space plasmas by increasingly high resolution, in situ observations as mirror wave mode structures. A typical requirement for the excitation of mirror modes is a dominant perpendicular pressure in a high-beta plasma environment. Contrary, we demonstrate from a realistic kinetic analysis how details of the velocity space distributions ar...

We describe an automated, volumetric particle image velocimetry (PIV) and tracking method that measures time-resolved, 3D zooplankton trajectories and surrounding volumetric fluid velocity fields simultaneously and non-intrusively. The method is demonstrated for groups of copepods flowing past a wall-mounted cylinder. We show that copepods execute escape responses when subjected to a strain rat...

A law of friction accompanying steady sliding motion between crystal lattices constituting a nano-electromechanical system (NEMS) was revealed by molecular dynamics simulations using simplified models. A threshold phenomenon was predicted as a common feature characterizing dependence of the wearless-frictional resistance on the sliding velocity vstroke. The threshold sliding velocity vth almost...

To improve the accuracy of acoustic emission (AE) source location, the wavelet packet transform is proposed to process the AE signals in this paper. The AE waves change shape due to the dispersion characteristics when they propagate in thin plates. Therefore, with the conventional method for AE source location by calculating arrival time differences based on the threshold crossing, the result i...