10,039 research outputs found

    Interferometer

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    A high resolution interferometer is described. The interferometer is insensitive to slight misalignment of its elements, avoids channeling in the spectrum, generates a maximum equal path fringe contrast, produces an even two sided interferogram without critical matching of the wedge angles of the beamsplitter and compensator wedges, and is optically phase tunable. The interferometer includes a mirror along the path of each beam component produced by the beamsplitter, for reflecting the beam component from the beamsplitter, for reflecting the beam component from the beamsplitter to a corresponding retroreflector and for reflecting the beam returned by the retroreflector back to the beamsplitter. A wedge located along each beam component path, is large enough to cover the retroreflector, so that each beam component passes through the wedge during movement towards the retroreflector and away therefrom

    The effect of ram pressure on the star formation, mass distribution and morphology of galaxies

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    We investigate the dependence of star formation and the distribution of the components of galaxies on the strength of ram pressure. Several mock observations in X-ray, Hα\alpha and HI wavelength for different ram-pressure scenarios are presented. By applying a combined N-body/hydrodynamic description (GADGET-2) with radiative cooling and a recipe for star formation and stellar feedback 12 different ram-pressure stripping scenarios for disc galaxies were calculated. Special emphasis was put on the gas within the disc and in the surroundings. All gas particles within the computational domain having the same mass resolution. The relative velocity was varied from 100 km/s to 1000 km/s in different surrounding gas densities in the range from 1×10−281\times10^{-28} to 5×10−275\times10^{-27} g/cm3^3. The temperature of the surrounding gas was initially 1×1071\times10^{7} K. The star formation of a galaxy is enhanced by more than a magnitude in the simulation with a high ram-pressure (5×10−115\times10^{-11} dyn/cm2^2) in comparison to the same system evolving in isolation. The enhancement of the star formation depends more on the surrounding gas density than on the relative velocity. Up to 95% of all newly formed stars can be found in the wake of the galaxy out to distances of more than 350 kpc behind the stellar disc. Continuously stars fall back to the old stellar disc, building up a bulge-like structure. Young stars can be found throughout the stripped wake with surface densities locally comparable to values in the inner stellar disc. Ram-pressure stripping can shift the location of star formation from the disc into the wake on very short timescales. (Abridged)Comment: 19 pages, 25 figures, A&A accepted, high resolution version can be found at http://astro.uibk.ac.at/~wolfgang/kapferer_rps_galaxies.pd

    Following Industry\u27s LEED : Municipal Adoption of Private Green Building Standards

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    Local governments are beginning to require new, privately constructed and funded buildings to be “green” buildings. Instead of creating their own, locally-derived definitions of green buildings, many municipalities are adopting an existing private standard created by members of the building industry: LEED (Leadership in Energy and Environmental Design). This Article explains and assesses the privately promulgated LEED standards. It argues that the translation of LEED standards, which were intended to be voluntary, into law raises several theoretical and practical problems. Specifically, private green building ordinances that rely on LEED do not ensure a reduction in the negative local environmental impacts of buildings, nor do they provide any assurance that those standards were created through a legitimate process. The Article concludes by offering an alternative approach, suggesting that municipalities should instead enact green building ordinances that have been promulgated by public governmental bodies, rather than private, industry-based organizations, and done so locally, taking into account specific local building-related and environmental concerns

    Encouraging Private Investment In Energy Efficiency

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    Combating the negative effects of climate change requires finding ways to increase energy production while reducing energy demand. Every New England state has programs in place to encourage home and business owners to improve the energy efficiency of their buildings. Despite the clear fmancial benefits and environmental benefits that result from energy efficiency upgrades, most New Englanders have not taken advantage ofthe programs being offered by their states

    The Future of Abandoned Big Box Stores : Legal Solutions to the Legacies of Poor Planning Decisions

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    Big box stores, the defining retail shopping location for the majority of American suburbs, are being abandoned at alarming rates, due in part to the economic downturn. These empty stores impose numerous negative externalities on the communities in which they are located, including blight, reduced property values, loss of tax revenue, environmental problems, and a decrease in social capital. While scholars have generated and critiqued prospective solutions to prevent abandonment of big box stores, this Article asserts that local zoning ordinances can alleviate the harms imposed by the thousands of existing, vacant big boxes. Because local governments control land use decisions and thus made deliberate determinations allowing big box development, this Article argues that those same local governments now have both an economic incentive and a civic responsibility to find alternative uses for these “ghostboxes.” With an eye toward sustainable development, the Article proposes and evaluates four possible alternative uses: retail reuse, adaptive reuse, demolition and redevelopment, and demolition and regreening. It then devises a framework and a series of metrics that local governments can use in deciding which of the possible solutions would be best suited for their communities. The Article concludes by considering issues of property acquisition and management

    Of Backyard Chickens and Front Yard Gardens: The Conflict Between Local Governments and Locavores

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    Locavores aim to source their food locally. Many locavores are also concerned more broadly with living sustainably and decreasing reliance on industrial agriculture. As more people have joined the locavore movement, including many who reside in urban and suburban areas, conflict has emerged between the locavores’ desires to use their private property to produce food — for personal use and for sale — and municipal zoning ordinances that seek to separate agriculture from residential uses. In this article, I consider the evolution of this conflict and its implications for our systems of land use, local government, and environmental law. Specifically, I investigate the police power rationales for the existence of ordinances that disallow urban homesteading in urban and suburban communities. I then demonstrate that public health, civic virtue, and free market principles can be used to justify the passage of ordinances that would expressly permit these behaviors. Central to this analysis is a discussion of the problems caused by industrial agriculture and the lack of access to locally produced foods — food insecurity, food deserts, obesity tied to processed foods, monoculture-induced environmental catastrophes, harm to animals, and greenhouse gas emissions — all of which could be alleviated, at least in part, through urban agriculture. In recognition of these changing conceptions of harm, some local governments have begun to pass ordinances expressly allowing gardens, chickens, and the sale of produce in residential areas. I conclude by considering what this movement toward loosening restrictions on the use of private property says more broadly about the decline of Euclidean zoning controls and the future of land use law
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