Polarization Light Curve Modeling of Corotating Interaction Regions in the Wind of the Wolf-Rayet Star WR 6

The intriguing WN4b star WR6 has been known to display epoch-dependent spectroscopic, photometric and polarimetric variability for several decades. In this paper, we set out to verify if a simplified analytical model in which Corotating Interaction Regions (CIRs) threading an otherwise spherical wind is able to reproduce the many broadband continuum light curves from the literature with a reasonable set of parameters. We modified the optically thin model we developed in Ignace, St-Louis & Proulx-Giraldeau (2015) to approximately account for multiple scattering and used it to fit 13 separate datasets of this star. By including two CIRs in the wind, we obtained reasonable fits for all datasets with coherent values for the inclination of the rotation axis ($i_0=166^{\circ}$) and for its orientation in the plane of the sky, although in the latter case we obtained two equally acceptable values ($\psi=63^{\circ}$ and $\psi=152^{\circ}$) from the polarimetry. Additional line profile variation simulations using the Sobolev approximation for the line transfer allowed us to eliminate the $\psi=152^{\circ}$ solution. With the adopted configuration ($i_0=166^{\circ}$ and $\psi=63^{\circ}$), we were able to reproduce all datasets relatively well with two CIRs located near the stellar equator and always separated by $\sim 90^{\circ}$ in longitude. The epoch-dependency comes from the fact that these CIRs migrate along the surface of the star. Density contrasts smaller than a factor of two and large opening angles for the CIR ($\beta \geq 35^{\circ}$) were found to best reproduce the type of spectroscopic variability reported in the literature.Comment: 15 pages, 5 figures,5 table

Tevatron results on the Standard Model Higgs search in the high-mass region

Results for the Tevatron search for the Higgs boson decaying to W boson pairs in proton antiproton collisions at √s = 1960 GeV/c2 are presented. The CDF results are based on the entire Tevatron Run II dataset having an integrated luminosity of 9.7 fb−1. The CDF results exclude a Standard Model Higgs at 95% confidence level for a Higgs mass MH in the range 148 ≤ MH ≤ 173GeV/c2 with an expected sensitivity of 153 ≤ MH ≤ 177GeV/c2, comparable to the previous Tevatron combined sample from July 2011

Correlations between eddy heat fluxes and baroclinic instability

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1979.Microfiche copy available in Archives and Science.Bibliography : leaf 83.by Richard St. Pierre.M.S

The Solution of Hypersingular Integral Equations With Applications in Acoustics and Fracture Mechanics

The numerical solution of two classes of hypersingular integral equations is addressed. Both classes are integral equations of the first kind, and are hypersingular due to a kernel containing a Hadamard singularity. The convergence of a Galerkin method and a collocation method is discussed and computationally efficient algorithms are developed for each class of hypersingular integral equation. Interest in these classes of hypersingular integral equations is due to their occurrence in many physical applications. In particular, investigations into the scattering of acoustic waves by moving objects and the study of dynamic Griffith crack problems has necessitated a computationally efficient technique for solving such equations. Fracture mechanic studies are performed using the aforementioned techniques. We focus our studies on problems addressing the Stress Intensity Factors (SIF) of a finite Griffith crack scattering an out of plane shear wave. In addition, we consider the problem of determining the SIF of two parallel Griffith cracks and two perpendicular Griffith cracks. It is shown that the method is very accurate and computationally efficient. In acoustics, we first consider the moving wing problem. For this problem we wish to find the sound produced by the interaction of a moving wing with a known incident sound source. Although this problem is relatively simple, it is a good precursor to the two-dimensional, finite, moving duct problem. The bulk of the research is focused on solving the two-dimensional, finite, moving duct problem. Here we look at sound propagation and radiation from a finite, two-dimensional, moving duct with a variety of inlet configurations. In particular, we conduct studies on the redirection of sound by a so-called scarf inlet design. In said designs, we are able to demonstrate the ability to redirect sound away from sensitive areas

Explaining Evil: The Holocaust in Hannah Arendt’s \u3cem\u3eEichmann in Jerusalem\u3c/em\u3e

About the author Scott Richard St. Louis is a student of history, political science, and French in the Frederik Meijer Honors College at Grand Valley State University in Allendale, Michigan, where he serves as the Student Senate Vice President for Educational Affairs. He also works as a Digital Archive Technician for the GVSU Veterans’ History Project