Saturn Atmospheric Structure and Dynamics

2 Saturn inhabits a dynamical regime of rapidly rotating, internally heated atmospheres similar to Jupiter. Zonal winds have remained fairly steady since the time of Voyager except in the equatorial zone and slightly stronger winds occur at deeper levels. Eddies supply energy to the jets at a rate somewhat less than on Jupiter and mix potential vorticity near westward jets. Convective clouds exist preferentially in cyclonic shear regions as on Jupiter but also near jets, including major outbreaks near 35°S associated with Saturn electrostatic discharges, and in sporadic giant equatorial storms perhaps generated from frequent events at depth. The implied meridional circulation at and below the visible cloud tops consists of upwelling (downwelling) at cyclonic (anti-cyclonic) shear latitudes. Thermal winds decay upward above the clouds, implying a reversal of the circulation there. Warm-core vortices with associated cyclonic circulations exist at both poles, including surrounding thick high clouds at the south pole. Disequilibrium gas concentrations in the tropical upper troposphere imply rising motion there. The radiative-convective boundary and tropopause occur at higher pressure in the southern (summer) hemisphere due to greater penetration of solar heating there. A temperature “knee ” of warm air below the tropopause, perhaps due to haze heating, is stronger in the summer hemisphere as well. Saturn’s south polar stratosphere is warmer than predicted by radiative models and enhanced in ethane, suggesting subsidence-driven adiabatic warming there. Recent modeling advances suggest that shallow weather laye

An organizational impression management perspective on the formation of corporate reputations

Researchers have only recently turned their attention to the study of corporate reputation. As is characteristic of many early areas of management inquiry, the field is decidedly multidisciplinary and disconnected. This article selectively reviews reputation research conducted mainly during the past decade. A framework is proposed that views reputation from the perspective of organizational impression management. Corporations are viewed as social actors, intent on enhancing their respectability and impressiveness in the eyes of constituents

Tyre/road interaction noise-A 3D viscoelastic multilayer model of a tyre belt

Vehicle noise is an increasing local environmental problem. For cars, above a steady speed of 40 km/h the noise produced by the interaction of the tyres with the road surface is the dominant noise source. In order to be able to predict this noise, the vibration characteristics of a stationary tyre must be determined. A multilayer viscoelastic cylindrical representation of the tyre belt, located between the sidewalls of the tyre and excluding the tread, is provided which yields the displacement and velocity response of the tyre belt when excited in the radial or tangential directions for it wide range of excitation frequencies, using only data from the design process. This model includes it representation of an air cavity and sidewalls and the response of the tyre belt is determined in both the frequency-wavenumber and time-spatial domains. The model can then be used to determine the noise of a tyre rolling on a rough road. (C) 2008 Published by Elsevier Ltd

Tyre/road interaction noise-Numerical noise prediction of a patterned tyre on a rough road surface

The noise which results from the interaction of pneumatic tyres with a rough road surface is a significant contributor to an increasing local environmental problem. Above a steady forward vehicle speed of 40 km/h this is the dominant noise source of a modern car in good working condition, and is a significant contributor to the overall radiated noise during acceleration.In order to determine the noise produced by a patterned tyre rolling on a rough road surface, the vibration characteristics of the tyre must be known. A method has been presented by O'Boy and Dowling [Tyre/road interaction noise: a 3d viscoelastic multilayer model of a tyre belt, Journal of Sound and Vibration, volume 322, issues 4-5, 22 May 2009, pages 829-850] which provides these vibration characteristics for a tyre belt composed of multiple viscoclastic layers, each layer having a different thickness and material properties. In this paper, we use this model of the tyre belt to determine the parameters of an equivalent simple bending plate model which can be adapted to yield the response of a tyre which includes sidewalls.A method is then described which uses this response to determine the acceleration of the tyre surface as it rolls over a rough road. These accelerations are then used to predict the far-field radiated noise for a patterned tyre on two rough road surfaces. Comparisons with experimental data are provided at each stage. (C) 2009 Published by Elsevier Ltd

Adaptive control of linear time-delay systems

International audienc

Suppression of spurious noise sources in airfoil selfnoise measurements

AIAA 2015-2689Aircraft Noise and Climate Effect