3,532 research outputs found

    Fixed-optics four-dimensional emittance measurement at the Spallation Neutron Source

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    A hadron beam with a uniform charge density, elliptical transverse profile, and small four-dimensional (4D) emittance could mitigate space charge effects in circular accelerators and improve collider performance. A phase space painting method to generate such a distribution is being tested in the Spallation Neutron Source (SNS) accumulator ring. A critical component of these efforts is to measure the 4D emittance of the beam. Reconstruction of the 4D emittance from wire-scanner data is a well-known technique. In this paper, we discuss the implementation of a variant of the multi-optics method using the four available wire-scanners near the SNS target, as well as the modification of the wire-scanner region to utilize the fixed-optics method, a method that is preferred due to its speed but can potentially lead to unacceptable bias and uncertainty in the reconstructed emittances. We then demonstrate the usefulness of the fixed-optics method by reconstructing the 4D emittance as a function of time during accumulation in the SNS ring

    The Extended Range X-Ray Telescope center director's discretionary fund report

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    An Extended Range X-Ray Telescope (ERXRT) of high sensitivity and spatial resolution capable of functioning over a broad region of the X-ray/XUV portion of the spectrum has been designed and analyzed. This system has been configured around the glancing-incidence Wolter Type I X-ray mirror system which was flown on the Skylab Apollo Telescope Mount as ATM Experiment S-056. Enhanced sensitivity over a vastly broader spectral range can be realized by the utilization of a thinned, back-illuminated, buried-channel Charge Coupled Device (CCD) as the X-ray/XUV detector rather than photographic film. However, to maintain the high spatial resolution inherent in the X-ray optics when a CCD of 30 micron pixel size is used, it is necessary to increase the telescope plate scale. This can be accomplished by use of a glancing-incidence X-ray microscope to enlarge and re-focus the primary image onto the focal surface of the CCD

    A Persistent Quandary: The Rural School Improvement Project, 1953-1957

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    Berea College\u27s Rural School Improvement Project worked directly with more than 5,000 children and 63 teaching fellows in 39 different schools over 13 counties, and one independent school district, involving 10 county school supervisors. Project estimates claimed an indirect impact on approximately 45,000 children within the RSIP school districts. The RSIP represented the thinking of national leaders of rural education in the 1950s who promoted improved administration of the schools combined with an active community engagement program based on “full respect for human personality” and “shared judgments.” Following so many decades of poverty and isolation, it is no easy task to gauge the impact of a program like the Rural School Improvement Project on the children and communities of southeastern Kentucky. Like the progress-minded projects that came before it - and those that would come after - the seemingly intractable challenges attending the Appalachian region kept educational equity at bay. Indeed, it would take another thirty-two years before the landmark Kentucky Supreme Court decision in Rose v Council for Better Education would declare the state’s inequitable and inadequate school system to be unconstitutional. “Sixty-six” property poor, and mostly rural, school districts had sued the General Assembly citing the abiding fiscal inequities which had grown to as much as an 8:1 ratio when compared to one urban district. With the passage of the Kentucky Education Reform Act, in 1990, the General Assembly provided substantial funding equity to rural schools - before returning to its historical pattern of periodic attention amid chronic neglect

    Storage of frozen meats, poultry, eggs, fruits, and vegetables

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    Digitized 2007 AES.Includes bibliographical references (pages 42-43)

    Notes

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    Notes by Robert E. Sullivan, Frederick N. Hoover, Robert Lowell Miller, Robert M. Million, F. Gerard Feeney, and James D. Sullivan

    Phase-Space Metric for Non-Hamiltonian Systems

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    We consider an invariant skew-symmetric phase-space metric for non-Hamiltonian systems. We say that the metric is an invariant if the metric tensor field is an integral of motion. We derive the time-dependent skew-symmetric phase-space metric that satisfies the Jacobi identity. The example of non-Hamiltonian systems with linear friction term is considered.Comment: 12 page

    Detection of curved lines with B-COSFIRE filters: A case study on crack delineation

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    The detection of curvilinear structures is an important step for various computer vision applications, ranging from medical image analysis for segmentation of blood vessels, to remote sensing for the identification of roads and rivers, and to biometrics and robotics, among others. %The visual system of the brain has remarkable abilities to detect curvilinear structures in noisy images. This is a nontrivial task especially for the detection of thin or incomplete curvilinear structures surrounded with noise. We propose a general purpose curvilinear structure detector that uses the brain-inspired trainable B-COSFIRE filters. It consists of four main steps, namely nonlinear filtering with B-COSFIRE, thinning with non-maximum suppression, hysteresis thresholding and morphological closing. We demonstrate its effectiveness on a data set of noisy images with cracked pavements, where we achieve state-of-the-art results (F-measure=0.865). The proposed method can be employed in any computer vision methodology that requires the delineation of curvilinear and elongated structures.Comment: Accepted at Computer Analysis of Images and Patterns (CAIP) 201

    Phase separation in mixtures of colloids and long ideal polymer coils

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    Colloidal suspensions with free polymer coils which are larger than the colloidal particles are considered. The polymer-colloid interaction is modeled by an extension of the Asakura-Oosawa model. Phase separation occurs into dilute and dense fluid phases of colloidal particles when polymer is added. The critical density of this transition tends to zero as the size of the polymer coils diverges.Comment: 5 pages, 3 figure
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