University of Arizona

About: University of Arizona is a education organization based out in Tucson, Arizona, United States. It is known for research contribution in the topics: Population & Galaxy. The organization has 63805 authors who have published 155998 publications receiving 6854915 citations. The organization is also known as: UA & U of A.

Moment Closure Hierarchies for Kinetic Theories

Abstract: This paper presents a systematicnonperturbative derivation of a hierarchy of closed systems of moment equations corresponding to any classical kinetic theory. The first member of the hierarchy is the Euler system, which is based on Maxwellian velocity distributions, while the second member is based on nonisotropic Gaussian velocity distributions. The closure proceeds in two steps. The first ensures that every member of the hierarchy is hyperbolic, has an entropy, and formally recovers the Euler limit. The second involves modifying the collisional terms so that members of the hierarchy beyound the second also recover the correct Navier-Stokes behavior. This is achieved through the introduction of a generalization of the BGK collision operator. The simplest such system in three spatial dimensions is a “14-moment” closure, which also recovers the behavior of the Grad “13-moment” system when the velocity distributions lie near local Maxwellians. The closure procedure can be applied to a general class of kinetic theories.

A New System of Faint Near-Infrared Standard Stars

Abstract: A new grid of 65 faint near-infrared standard stars is presented. They are spread around the sky, lie between 10th and 12th magnitude at K, and are measured in most cases to precisions better than 0.001 mag in the J, H, K, and Ks bands; the latter is a medium-band modified K. A secondary list of red stars suitable for determining color transformations between photometric systems is also presented.

Toward a theory of marketing control: Environmental context, control types, and consequences.

Abstract: Historically, marketing control research has involved either the development of output-oriented financial controls or the analysis of how financial controls affect performance. This work on marketi...