Drift velocity and longitudinal diffusion measurements are reported for a Negative Ion TPC (NITPC) operating with Helium + CS 2 gas mixtures at total pressures from 160 to 700 torr. Longitudinal diffusion at the thermal-limit was observed for drift fields up to at least 700 V/cm in all gas mixtures tested. The results are of particular interest in connection with mechanical simplification of Da...

The temporal evolution of drift-Alfv en waves in a plasma ow with homogeneous shear is studied as an initial value problem without the use of spectral expansion in time. It is shown that the conventional modal structure of the drift-Alfv en instability (as well as drift and Alfv en waves) pertains only in the initial stage of its evolution. For larger times, non-modal e ects due to the velocity...

We investigate a dissipative, deterministic ratchet model in the overdamped regime driven by a rectangular force. Extensive numerical calculations are presented in a diagram depicting the drift velocity as a function of a wide range of the driving parameter values. We also present some theoretical considerations which explain some features of the mentioned diagram. In particular, we proof the e...

The mean electromotive force is considered in a differentially rotating fluid taking into account stretching of the turbulent magnetic field. Calculations are performed by making use of the second order correlation approximation. Nonuniformity of the angular velocity leads to specific drift processes in the azimuthal direction. Due to this drift the magnetic field can rotate with a somewhat dif...

This paper presents a set of filters with globally exponentially stable error dynamics for source localization and navigation, in 3-D, based on directionmeasurements from the agent (or vehicle) to the source, in addition to relative velocity readings of the agent. Both the source and the agent are allowed to have constant unknown drift velocities and the relative drift velocity is also explicit...

Downbeat nystagmus is a frequent ocular motor sign in patients with lesions of the vestibulocerebellum. The upward drift in downbeat nystagmus is a combination of a gaze-evoked drift, due to an impaired vertical neural integrator, and a velocity bias. Using a three-dimensional turntable, we analyzed the influence of gravity on these two mechanisms. Patients with cerebellar downbeat nystagmus (n...

The relativistic effects on the TM-modes of one boundary corrugated parallel plate waveguide filled with uniaxial warm drifting plasma have been investigated. The dispersion relation for the TM-modes has been derived and the numerical computations have been carried out to study the effects of increased (relativistic) drift velocity and the temperature under this condition. The effects of drift ...

Recently, using DiGiorgi-type techniques, Caffarelli and Vasseur [1] showed that a certain class of weak solutions to the drift diffusion equation with initial data in L gain Hölder continuity provided that the BMO norm of the drift velocity is bounded uniformly in time. We show a related result: a uniform bound on BMO norm of a smooth velocity implies uniform bound on the C norm of the solutio...

Spectral lines formed in stellar winds from OB stars are observed to exhibit profile variations. Discrete Absorption Components (DACs) show a remarkably slow wavelength drift with time. In a straightforward interpretation, this is in sharp contradiction to the steep velocity law predicted by the radiation-driven wind theory, and by semi-empirical profile fitting. In the present paper we re-disc...