3,311 research outputs found
Reduced dynamics and Lagrangian submanifolds of symplectic manifolds
In this paper, we will see that the symplectic creed by Weinstein "everything
is a Lagrangian submanifold" also holds for Hamilton-Poincar\'e and
Lagrange-Poincar\'e reduction. In fact, we show that solutions of the
Hamilton-Poincar\'e equations and of the Lagrange-Poincar\'e equations are in
one-to-one correspondence with distinguished curves in a Lagrangian submanifold
of a symplectic manifold. For this purpose, we will combine the concept of a
Tulczyjew triple with Marsden-Weinstein symplectic reduction.Comment: 26 page
Leibniz algebroid associated with a Nambu-Poisson structure
The notion of Leibniz algebroid is introduced, and it is shown that each
Nambu-Poisson manifold has associated a canonical Leibniz algebroid. This fact
permits to define the modular class of a Nambu-Poisson manifold as an
appropiate cohomology class, extending the well-known modular class of Poisson
manifolds
Core Competencies and Strategies for Effective Leadership
Book Review of: ΓÇ£The Teacher LeaderΓÇ¥ by Daniel R. Tomal, Craig A. Schilling, and Robert K. Wilhit
Why Master Teachers Do What They Do
Review of the book:  “Those Who Can: Why Master Teachers Do What They Do.” By Neil Bright. Lanham, MD: Rowman and Littlefield, 2013. ISBN: 978-1475801453.  Do What They Do, master teacher, administrator, and curriculum developer Neil Bright distills the secrets of effective teaching into fifteen “practices” that he describes using clear language and extensive support from research literature
Air quality in the Industrial Heartland of Alberta, Canada and potential impacts on human health.
The "Industrial Heartland" of Alberta is Canada's largest hydrocarbon processing center, with more than 40 major chemical, petrochemical, and oil and gas facilities. Emissions from these industries affect local air quality and human health. This paper characterizes ambient levels of 77 volatile organic compounds (VOCs) in the region using high-precision measurements collected in summer 2010. Remarkably strong enhancements of 43 VOCs were detected, and concentrations in the industrial plumes were often similar to or even higher than levels measured in some of the world's largest cities and industrial regions. For example maximum levels of propene and i-pentane exceeded 100 ppbv, and 1,3-butadiene, a known carcinogen, reached 27 ppbv. Major VOC sources included propene fractionation, diluent separation and bitumen processing. Emissions of the measured VOCs increased the hydroxyl radical reactivity (kOH), a measure of the potential to form downwind ozone, from 3.4 s-1 in background air to 62 s-1 in the most concentrated plumes. The plume value was comparable to polluted megacity values, and acetaldehyde, propene and 1,3-butadiene contributed over half of the plume kOH. Based on a 13-year record (1994-2006) at the county level, the incidence of male hematopoietic cancers (leukemia and non-Hodgkin lymphoma) was higher in communities closest to the Industrial Heartland compared to neighboring counties. While a causal association between these cancers and exposure to industrial emissions cannot be confirmed, this pattern and the elevated VOC levels warrant actions to reduce emissions of known carcinogens, including benzene and 1,3-butadiene
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