Saint Mary's University

About: Saint Mary's University is a education organization based out in Halifax, Nova Scotia, Canada. It is known for research contribution in the topics: Population & Stars. The organization has 1931 authors who have published 4993 publications receiving 143226 citations.

New Constraints on the Black Hole Low/Hard State Inner Accretion Flow with NuSTAR

Abstract: We report on an observation of the Galactic black hole candidate GRS 1739-278 during its 2014 outburst, obtained with NuSTAR. The source was captured at the peak of a rising "low/hard" state, at a flux of ~0.3 Crab. A broad, skewed iron line and disk reflection spectrum are revealed. Fits to the sensitive NuSTAR spectra with a number of relativistically blurred disk reflection models yield strong geometrical constraints on the disk and hard X-ray "corona". Two models that explicitly assume a "lamppost" corona find its base to have a vertical height above the black hole of h = 5 (+7, -2) GM/c^2 and h = 18 +/-4 GM/c^2 (90% confidence errors); models that do not assume a "lamppost" return emissivity profiles that are broadly consistent with coronae of this size. Given that X-ray microlensing studies of quasars and reverberation lags in Seyferts find similarly compact coronae, observations may now signal that compact coronae are fundamental across the black hole mass scale. All of the models fit to GRS 1739-278 find that the accretion disk extends very close to the black hole - the least stringent constraint is r = 5 (+3,-4) GM/c^2. Only two of the models deliver meaningful spin constraints, but a = 0.8 +/-0.2 is consistent with all of the fits. Overall, the data provide especially compelling evidence of an association between compact hard X-ray coronae and the base of relativistic radio jets in black holes.

Kenneth Burke and the method of dramatism

Abstract: It is possible that sociologists have read the work of Kenneth Burke and found it neither important nor interesting, a One searches in vain for any expository treatment of his work in those journals read by sociologists, or indeed, for any expository treatment of the sociological importance of Burke in other journals. Yet Burke has been lurking in sociologists' footnotes since the 1930s, and recently his system, "Dramatism," has been promoted to equal rank with "Symbolic Interaction" and "Social Exchange" in the coverage given to these aspects of "Interaction" in the InternationalEneyelopedia o f the Social Scienees. ~ What are we to make of this?

Diffraction-limited bispectrum speckle interferometry of the nuclear region of the Seyfert galaxy NGC 1068 in the H and K' bands

Abstract: We present near-infrared bispectrum speckle interferometry studies of the nuclear region of the Seyfert 2 galaxy NGC 1068. A diffraction-limited K � -band image with 74 mas resolution and the first H-band image with 57 mas resolution were reconstructed from speckle interferograms obtained with the SAO 6 m telescope. The resolved structure consists of a compact core and an extended northern and south-eastern component. The compact core is resolved at all position angles and has a north-western, tail-shaped extension as well as a fainter, south-eastern extension. The K � -band FWHM diameter of this compact core is approximately 18 × 39 mas or 1.3 × 2.8 pc (FWHM of a single-component Gaussian fit; fit range 30-80% of the telescope cut-off frequency; the diameter errors are ±4 mas), and the position angle (PA) of the north-western extension is -16 ± 4 ◦ . If 40% of the flux from the compact Kcore is emission from a point source and 60% from a Gaussian intensity distribution, then a slightly larger FWHM of approximately 26 × 58 mas is obtained for the compact Kcomponent. In the H band, the FWHM diameter of the compact core is approximately 18 × 45 mas (±4 mas), and the PA is -18 ± 4 ◦ . The extended northern component (PA ∼ 0 ◦ ) has an elongated structure with a length of about 400 mas or 29 pc. The extended south-eastern component is fainter than the northern component. The K � -a ndH-band fluxes from the resolved compact core were measured to be 350 ± 90 mJy (i.e., K � ∼ 8.2 m ) and 70 ± 20 mJy (H ∼ 10.4 m ), respectively. The PA of -16 ± 4 ◦ of the compact 18 × 39 mas core is very similar to that of the western wall (PA ∼ -15 ◦ ) of the bright region of the ionization cone. This suggests that the H- and K � -band emission from the compact core is both thermal emission and scattered light from dust near the western wall of a low-density, conical cavity or from the innermost region of a parsec-scale dusty torus that is heated by the central source (the dust sublimation radius of NGC 1068 is approximately 0.1-1 pc). The northern extended 400 mas structure lies near the western wall of the ionization cone and coincides with the inner radio jet (PA ∼ 11 ◦ ). The large distance from the core suggests that the K � -band emission of the northern extended component is scattered light from the western cavity region and the radio jet region.

Implementation of Sliding Mode Control System for Generator and Grid Sides Control of Wind Energy Conversion System

Abstract: This paper presents a second order sliding mode control strategy to control the generator and the grid sides of a variable speed experimental wind energy conversion system. At the generator side, the rotational speed is controlled to track a profile generated from the power curve of the wind turbine for maximum power extraction. At the grid side, the dc-link voltage is regulated for a proper transfer of power. The control strategy is based on a disturbed single input-single output error model and a second order sliding mode control algorithm. The proposed second order sliding mode control strategy offers interesting characteristics such as robustness to parametric uncertainties in the turbine and the generator as well as external disturbances. The proposed strategy, for speed and dc-link voltage control in wind energy conversion system, is validated on an emulated wind turbine driven by the OPAL-RT real-time simulator (OP5600). Experimental results show that the proposed control strategy is effective in terms of speed and dc-link voltage control. The sliding mode control approach is robust against unknown disturbances, parametric variations, and uncertainties in the system. Furthermore, it produces no chattering in the generated torque, which reduces the mechanical stress on the wind turbine.

Marital Satisfaction, Sex, Age, Marriage Duration, Religion, Number of Children, Economic Status, Education, and Collectivistic Values: Data from 33 Countries

Abstract: Forms of committed relationships, including formal marriage arrangements between men and women, exist in almost every culture (Bell, 1997). Yet, similarly to many other psychological constructs (Henrich et al., 2010), marital satisfaction and its correlates have been investigated almost exclusively in Western countries (e.g., Bradbury et al., 2000). Meanwhile, marital relationships are heavily guided by culturally determined norms, customs, and expectations (for review see Berscheid, 1995; Fiske et al., 1998). While we acknowledge the differences existing both between- and within-cultures, we measured marital satisfaction and several factors that might potentially correlate with it based on self-report data from individuals across 33 countries. The purpose of this paper is to introduce the raw data available for anybody interested in further examining any relations between them and other country-level scores obtained elsewhere. Below, we review the central variables that are likely to be related to marital satisfaction