Phase space simulation of collisionless stellar systems on the massively parallel processor

A numerical technique for solving the collisionless Boltzmann equation describing the time evolution of a self gravitating fluid in phase space was implemented on the Massively Parallel Processor (MPP). The code performs calculations for a two dimensional phase space grid (with one space and one velocity dimension). Some results from calculations are presented. The execution speed of the code is comparable to the speed of a single processor of a Cray-XMP. Advantages and disadvantages of the MPP architecture for this type of problem are discussed. The nearest neighbor connectivity of the MPP array does not pose a significant obstacle. Future MPP-like machines should have much more local memory and easier access to staging memory and disks in order to be effective for this type of problem

A new class of galactic discrete gamma ray sources: Chaotic winds of massive stars

We propose a new class of galactic discrete gamma-ray sources, the chaotic, high mass-loss-rate winds from luminous early-type stars. Early-type stellar winds are highly unstable due to intrinsic line-driven instabilities, and so are permeated by numerous strong shocks. These shocks can accelerate a small fraction of thermal electrons and ions to relativistic energies via the first-order Fermi mechanism. A power-law-like photon spectrum extending from keV to above 10 MeV energies is produced by inverse Compton scattering of the extremely abundant stellar UV photons by the relativistic electrons. In addition, a typical pi(sup 0)-decay gamma-ray spectrum is generated by proton-ion interactions in the densest part of the winds

Low energy gamma ray emission from the Cygnus OB2 association

According to our newly developed model of gamma-ray emission from chaotic early-type stellar winds, we predict the combined gamma-ray flux from the circumstellar winds of many very luminous early-type stars in the Cyg OB2 association can be detectable by the Energetic Gamma Ray Experiment Telescope (EGRET) (and maybe also by OSSE) on CGRO. Due to different radiation mechanisms, the gamma-ray spectrum from stellar winds can be quite different from that of CYG X-3; this spectral difference and the time-variation of Cyg X-3 flux will help to distinguish the gamma-ray components from different sources in this small region, which is spatially unresolvable by CGRO

NATIONAL "E-EXTENSION" PROGRAMS: FEASIBILITY AND STRUCTURE

Illinois agriculture and natural resource e-Extension programs have exceeded expectations. National e-Extension programs will also succeed given they explicitly help clients make decisions, make available user-friendly decision tools and data, use GIS, reward the programs' interdisciplinary teams, and use the web for seamless integration across states.Teaching/Communication/Extension/Profession,

Chris Argyris and Organizational Behavior

This paper is about organizational behavior and one man\u27s research and ideas about this subject. That man is Chris Argyris. Chris Argyris has been at Yale University for nearly two decades as a professor of Industrial Administration until recently moving to Harvard. During that period of time he has evolved from a beginning student of the behavioral sciences to a respected scholar and research authority in the field of organizational behavior. His own ideas have changed from a beginning theoretical framework to more established and accepted commentaries on organizational behavior. The purpose of this paper is to dissect and explain Argyris\u27s ideas and theories about the broad field of human relations in organizations called organizational behavior. The paper could also serve as an introduction to organizational behavior for the uninitiated. This author will not attempt to criticize nor condone the work done by Argyris. Such a task will be left for the more informed student of organizational behavior. The paper will make an effort to describe Argyris\u27s viewpoints on the different aspects of organizational behavior from his early beginnings to his more recent works. The reader will witness that Argyris retains many of his early premises throughout the span covered, As would be predicted Argyris also produced new ideas, theories, and techniques as he continued his research