2,315 research outputs found

    Delineation of geological problems for use in urban planning

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    Activities of the University of Alabama in support of state and local planning commissions are reported. Demonstrations were given of the various types of remotely sensed images available from U-2, Skylab, and LANDSAT; and their uses and limitations were discussed. Techniques to be used in determining flood prone areas were provided for environmental studies. A rapid, inexpensive method for study was developed by which imagery is copied on 35 mm film and projected on existing topographic maps for measuring delta volume and growth

    Assessment of practicality of remote sensing techniques for a study of the effects of strip mining in Alabama

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    Because of the volume of coal produced by strip mining, the proximity of mining operations, and the diversity of mining methods (e.g. contour stripping, area stripping, multiple seam stripping, and augering, as well as underground mining), the Warrior Coal Basin seemed best suited for initial studies on the physical impact of strip mining in Alabama. Two test sites, (Cordova and Searles) representative of the various strip mining techniques and environmental problems, were chosen for intensive studies of the correlation between remote sensing and ground truth data. Efforts were eventually concentrated in the Searles Area, since it is more accessible and offers a better opportunity for study of erosional and depositional processes than the Cordova Area

    Gas gun shock experiments with single-pulse x-ray phase contrast imaging and diffraction at the Advanced Photon Source

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    The highly transient nature of shock loading and pronounced microstructure effects on dynamic materials response call for {\it in situ}, temporally and spatially resolved, x-ray-based diagnostics. Third-generation synchrotron x-ray sources are advantageous for x-ray phase contrast imaging (PCI) and diffraction under dynamic loading, due to their high photon energy, high photon fluxes, high coherency, and high pulse repetition rates. The feasibility of bulk-scale gas gun shock experiments with dynamic x-ray PCI and diffraction measurements was investigated at the beamline 32ID-B of the Advanced Photon Source. The x-ray beam characteristics, experimental setup, x-ray diagnostics, and static and dynamic test results are described. We demonstrate ultrafast, multiframe, single-pulse PCI measurements with unprecedented temporal (<<100 ps) and spatial (∌\sim2 ÎŒ\mum) resolutions for bulk-scale shock experiments, as well as single-pulse dynamic Laue diffraction. The results not only substantiate the potential of synchrotron-based experiments for addressing a variety of shock physics problems, but also allow us to identify the technical challenges related to image detection, x-ray source, and dynamic loading

    Ferrite attenuator modulation improves antenna performance

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    Ferrite attenuator inserted into appropriate waveguide reduces the gain of the antenna element which is causing interference. Modulating the ferrite attenuator to change the antenna gain at the receive frequency permits ground tracking until the antenna is no longer needed

    Three-Dimensional Mechanics of Yakutat Convergence in the Southern Alaskan Plate Corner

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    Three-dimensional numerical models are used to investigate the mechanical evolution of the southern Alaskan plate corner where the Yakutat and the Pacific plates converge on the North American plate. The evolving model plate boundary consists of Convergent, Lateral, and Subduction subboundaries with flow separation of incoming material into upward or downward trajectories forming dual, nonlinear advective thermal/mechanical anomalies that fix the position of major subaerial mountain belts. The model convergent subboundary evolves into two teleconnected orogens: Inlet and Outlet orogens form at locations that correspond with the St. Elias and the Central Alaska Range, respectively, linked to the East by the Lateral boundary. Basins form parallel to the orogens in response to the downward component of velocity associated with subduction. Strain along the Lateral subboundary varies as a function of orogen rheology and magnitude and distribution of erosion. Strain-dependent shear resistance of the plate boundary associated with the shallow subduction zone controls the position of the Inlet orogen. The linkages among these plate boundaries display maximum shear strain rates in the horizontal and vertical planes where the Lateral subboundary joins the Inlet and Outlet orogens. The location of the strain maxima shifts with time as the separation of the Inlet and Outlet orogens increases. The spatiotemporal predictions of the model are consistent with observed exhumation histories deduced from thermochronology, as well as stratigraphic studies of synorogenic deposits. In addition, the complex structural evolution of the St Elias region is broadly consistent with the predicted strain field evolution. Citation: Koons, P. O., B. P. Hooks, T. Pavlis, P. Upton, and A. D. Barker (2010), Three-dimensional mechanics of Yakutat convergence in the southern Alaskan plate corner, Tectonics, 29, TC4008, doi: 10.1029/2009TC002463

    Women, know your limits: Cultural sexism in academia

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    Despite the considerable advances of the feminist movement across Western societies, in Universities women are less likely to be promoted, or paid as much as their male colleagues, or even get jobs in the first place. One way in which we can start to reflect on why this might be the case is through hearing the experiences of women academics themselves. Using feminist methodology, this article attempts to unpack and explore just some examples of ‘cultural sexism’ which characterise the working lives of many women in British academia.This article uses qualitative methods to describe and make sense of just some of those experiences. In so doing, the argument is also made that the activity of academia is profoundly gendered and this explicit acknowledgement may contribute to our understanding of the under-representation of women in senior positions

    Transcendence over Diversity: black women in the academy

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    Universities, like many major public institutions have embraced the notion of ‘diversity’ virtually uncritically- it is seen as a moral ‘good in itself’. But what happens to those who come to represent ‘diversity’- the black and minority ethnic groups targeted to increase the institutions thirst for global markets and aversion to accusations of institutional racism? Drawing on existing literature which analyses the process of marginalization in higher education, this paper explores the individual costs to black and female academic staff regardless of the discourse on diversity. However despite the exclusion of staff, black and minority ethnic women are also entering higher education in relatively large numbers as students. Such ‘grassroots’ educational urgency transcends the dominant discourse on diversity and challenges presumptions inherent in top down initiatives such as ‘widening participation’. Such a collective movement from the bottom up shows the importance of understanding black female agency when unpacking the complex dynamics of gendered and racialised exclusion. Black women’s desire for education and learning makes possible a reclaiming of higher education from creeping instrumentalism and reinstates it as a radical site of resistance and refutation

    Ephus: Multipurpose Data Acquisition Software for Neuroscience Experiments

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    Physiological measurements in neuroscience experiments often involve complex stimulus paradigms and multiple data channels. Ephus (http://www.ephus.org) is an open-source software package designed for general-purpose data acquisition and instrument control. Ephus operates as a collection of modular programs, including an ephys program for standard whole-cell recording with single or multiple electrodes in typical electrophysiological experiments, and a mapper program for synaptic circuit mapping experiments involving laser scanning photostimulation based on glutamate uncaging or channelrhodopsin-2 excitation. Custom user functions allow user-extensibility at multiple levels, including on-line analysis and closed-loop experiments, where experimental parameters can be changed based on recently acquired data, such as during in vivo behavioral experiments. Ephus is compatible with a variety of data acquisition and imaging hardware. This paper describes the main features and modules of Ephus and their use in representative experimental applications
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