NGC 4258 is well known for its 22 GHz water maser features that appear to reside in a thin Keplerian disk orbiting at R0 = 0.13 pc. The influence of gravitational redshift on the level of saturation and the line shape and strength of water maser emission is studied. It is found, for a Schwarzschild metric, that a time-dependent and asymmetric absorption dip occurs in the systemic emission for a...

The high field transport regime of single gate (SG) SOI MOSFETs has been the subject of an in-depth characterization. To study this, we have used a Monte Carlo simulator where all the major features involved in the description of the transport of state-of-the-art SOI devices are taken into account: quantization, non-parabolic band structure, phonon and surface roughness scattering. It has been ...

Introduction: Functional MRI has been extensively used to indirectly measure changes in neuronal activation via the BOLD (blood oxygenation level dependent) effect. While BOLD fMRI provides a relative signal that fluctuates based on changes in venous oxygenation, the absolute value of venous oxygen saturation at baseline and during activation is unknown. Additionally, the BOLD response is highl...

This paper investigates the velocity-free feedback control problem associated with finite time attitude stabilization of a rigid spacecraft subject to external disturbance and input saturation. First of all, to address the lack of angular velocity measurement, a novel, fast, finite time convergent observer is proposed to recover the unknown angular velocity information in a finite time under ex...

For wave propagation at low frequencies in a porous medium, the Gassmann-Domenico relations are well-established for homogeneous partial saturation by a liquid. They provide the correct relations for seismic velocities in terms of constituent bulk and shear moduli, solid and fluid densities, porosity and saturation. It has not been possible, however, to invert these relations easily to determin...

S U M M A R Y Using a numerical approach, we explore wave-induced fluid flow effects in partially saturated porous rocks in which the gas–water saturation patterns are governed by mesoscopic heterogeneities associated with the dry frame properties. The link between the dry frame properties and the gas saturation is defined by the assumption of capillary pressure equilibrium, which in the presen...

Offline crane maneuvers, resulting in zero residual payload swing, have been explored previously using parameterized sets of basis functions. Assumptions usually included an ideal servo response and symmetric inputs. Nonsymmetric maneuvers, in general, do not have closedform basis function solutions. Actuator dynamics further complicate maneuver generation by introducing nonlinearities such as ...