1,740 research outputs found

    The RTA Betatron-Node Experiment: Limiting Cumulative BBU Growth In A Linear Periodic System

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    The successful operation of a Two-Beam accelerator based on extended relativistic klystrons hinges upon decreasing the cumulative dipole BBU growth from an exponential to a more manageable linear growth rate. We describe the theoretical scheme to achieve this, and a new experiment to test this concept. The experiment utilizes a 1-MeV, 600-Amp, 200-ns electron beam and a short beamline of periodically-spaced rf dipole-mode pillbox cavities and solenoid magnets for transport. Descriptions of the beamline are presented, followed by theoretical studies of the beam transport and dipole-mode growth.Comment: 3 pages, 3 figures. Submitted to XX Int'l. LINAC Conferenc

    Improving Care and Outcomes for the Late Preterm Infant

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    Abstract The late preterm infant population is the fastest growing and largest segment of preterm infants delivered on a global level. Neonatal Intensive Care Unit transfer and Pediatric unit re-admission rates were examined at a regional medical center in the context of providing an evidence-based practice guideline designed specifically for this cohort of newborns. Prior to instituting the Association of Women\u27s Heath, Obstetric, and Neonatal Nurses Assessment and care of the late preterm infant: Evidence-based clinical practice guideline at a regional medical center, NICU transfer and Pediatric re-admission rates were retrospectively examined. After instituting the guideline for a six-month period, the rates were re-examined for comparison. The results included a significant decrease in Pediatric re-admissions and a slight increase in NICU transfers. These findings suggest a specialized pathway and increased surveillance may reduce costly preventable rehospitalization

    OAO-2 observations of beta Lyrae and a provisional interpretation

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    Six-color ultraviolet photoelectric observations of beta Lyrae obtained with OAO-2 are presented. These observations, made at 1380, 1500, 1920, 2460, 2980 and 3330 A, represent the first truly continual coverage of the light changes of beta Lyrae during one orbital revolution and were obtained in November 1970. The photometric data are supplemented by spectral scans in the wavelength intervals 3800-1800 A and 2000-1050 A; the latter interval was scanned at 10 A resolution once during every OAO-2 orbit, i.e., about 100 minutes. Anomalous features, such as asymmetries and short and long term variations, are present in the light curves. A tentative discussion of solutions of the light curves is given

    Pilot Data: Are Vertical and Lateral Hop Tests Appropriate for Patients Post-Ankle Fracture?

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    Ankle fractures effect 5 out of 10,000 individuals (van Staa, 2001). A recent study shows rapid functional gains over the first 6 months after an ankle fracture, but there are little or no gains 18-24 months into the recovery cycle (Beckenkamp, 2014). Similarly, other studies have shown that ankle fracture patients are categorized as having good recovery outcomes on popular measures such as the modified Olerud Molander scale (Egol, 2006), yet are unable to return to previous level of sport (Hong, 2013), indicating there may be persisting higher level performance deficits. This brings up the issue of whether there are performance based tests that would be appropriate for ankle fracture patients to determine return to sport or higher level activity without risk of injury. The purpose of this project is to determine the biomechanical load and side to side comparisons of vertical and lateral hopping tests that may be used in ankle fracture patients

    Detection of sulphur in the galactic center

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    A strong detection at the (SIII) 18.71 micron line is reported for the Galactic Center region, Sgr A West. A line flux of 1.7 + or - 0.2x10 to the -17th power W cm(-2) is found for a 20-arc second beam-size measurement centered on IRS 1. A preliminary analysis indicates that the SIII abundance relative to hydrogen is consistent with the cosmic abundance of sulfur, 1.6x10 to the -5th power, if a filling factor of unity within the known clumps is assumed. However, the sulfur abundance in the Galactic Center may be as much as a factor of 3 overabundant if a filling factor of 0.03 is adopted, a value found to hold for some galactic HII regions

    The mission oriented terminal area simulation facility

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    The Mission Oriented Terminal Area Simulation (MOTAS) was developed to provide an ATC environment in which flight management and flight operations research studies can be conducted with a high degree of realism. This facility provides a flexible and comprehensive simulation of the airborne, ground-based and communication aspects of the airport terminal area environment. Major elements of the simulation are: an airport terminal area environment model, two air traffic controller stations, several aircraft models and simulator cockpits, four pseudo pilot stations, and a realistic air-ground communications network. MOTAS has been used for one study with the DC-9 simulator and a series of data link studies are planned in the near future

    High-Redshift Dust Obscured Galaxies: A Morphology-Spectral Energy Distribution Connection Revealed by Keck Adaptive Optics

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    A simple optical to mid-IR color selection, R – [24]>14, i.e., f_ν(24 μm)/f_ν(R) ≳ 1000, identifies highly dust obscured galaxies (DOGs) with typical redshifts of z ~ 2 ± 0.5. Extreme mid-IR luminosities (L_(IR) > 10^(12-14)) suggest that DOGs are powered by a combination of active galactic nuclei (AGNs) and star formation, possibly driven by mergers. In an effort to compare their photometric properties with their rest-frame optical morphologies, we obtained high-spatial resolution (0."05-0."1) Keck Adaptive Optics K'-band images of 15 DOGs. The images reveal a wide range of morphologies, including small exponential disks (eight of 15), small ellipticals (four of 15), and unresolved sources (two of 15). One particularly diffuse source could not be classified because of low signal-to-noise ratio. We find a statistically significant correlation between galaxy concentration and mid-IR luminosity, with the most luminous DOGs exhibiting higher concentration and smaller physical size. DOGs with high concentration also tend to have spectral energy distributions (SEDs) suggestive of AGN activity. Thus, central AGN light may be biasing the morphologies of the more luminous DOGs to higher concentration. Conversely, more diffuse DOGs tend to show an SED shape suggestive of star formation. Two of 15 in the sample show multiple resolved components with separations of ~1 kpc, circumstantial evidence for ongoing mergers
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