3,378 research outputs found

    Identifying Extension Information Delivery Methods For Environmental Issues

    Get PDF
    The primary purpose of this study was to identify the types of information sources that farmers find useful, and the human resource organizations they depend upon when confronted with environmental issues

    Validating gravitational-wave detections: The Advanced LIGO hardware injection system

    Get PDF
    Hardware injections are simulated gravitational-wave signals added to the Laser Interferometer Gravitational-wave Observatory (LIGO). The detectors’ test masses are physically displaced by an actuator in order to simulate the effects of a gravitational wave. The simulated signal initiates a control-system response which mimics that of a true gravitational wave. This provides an end-to-end test of LIGO’s ability to observe gravitational waves. The gravitational-wave analyses used to detect and characterize signals are exercised with hardware injections. By looking for discrepancies between the injected and recovered signals, we are able to characterize the performance of analyses and the coupling of instrumental subsystems to the detectors’ output channels. This paper describes the hardware injection system and the recovery of injected signals representing binary black hole mergers, a stochastic gravitational wave background, spinning neutron stars, and sine-Gaussians

    Conversations for Collaboration: Librarians and the High School to College Transition in Louisiana.

    Get PDF
    Conversations for Collaboration: Librarians and the High School to College Transition in Louisiana. With Anthony J. Fonseca, Debra Cox Rollins, and Kathryn B. Seidel in Informed Transitions: Libraries Supporting the High School to College Transition, Kenneth J. Burhanna, Editor. Santa Barbara, CA, Libraries Unlimited, 2013

    Surface Superconductivity in Niobium for Superconducting RF Cavities

    Full text link
    A systematic study is presented on the superconductivity (sc) parameters of the ultrapure niobium used for the fabrication of the nine-cell 1.3 GHz cavities for the linear collider project TESLA. Cylindrical Nb samples have been subjected to the same surface treatments that are applied to the TESLA cavities: buffered chemical polishing (BCP), electrolytic polishing (EP), low-temperature bakeout (LTB). The magnetization curves and the complex magnetic susceptibility have been measured over a wide range of temperatures and dc magnetic fields, and also for di erent frequencies of the applied ac magnetic field. The bulk superconductivity parameters such as the critical temperature Tc = 9.26 K and the upper critical field Bc2(0) = 410 mT are found to be in good agreement with previous data. Evidence for surface superconductivity at fields above Bc2 is found in all samples. The critical surface field exceeds the Ginzburg-Landau field Bc3 = 1.695Bc2 by about 10% in BCP-treated samples and increases even further if EP or LTB are applied. From the field dependence of the susceptibility and a power-law analysis of the complex ac conductivity and resistivity the existence of two different phases of surface superconductivity can be established which resemble the Meissner and Abrikosov phases in the bulk: (1) coherent surface superconductivity, allowing sc shielding currents flowing around the entire cylindrical sample, for external fields B in the range between Bc2 and Bcohc3, and (2) incoherent surface superconductivity with disconnected sc domains between Bcohc3 and Bc3. The coherent critical surface field separating the two phases is found to be Bcoh c3 = 0.81Bc3 for all samples. The exponents in the power law analysis are different for BCP and EP samples, pointing to different surface topologies.Comment: 15 pages, 21 figures, DESY-Report 2004-02

    Heat and water transport in soils and across the soil-atmosphere interface: 1. Theory and different model concepts

    Get PDF
    Evaporation is an important component of the soil water balance. It is composed of water flow and transport processes in a porous medium that are coupled with heat fluxes and free air flow. This work provides a comprehensive review of model concepts used in different research fields to describe evaporation. Concepts range from nonisothermal two-phase flow, two-component transport in the porous medium that is coupled with one-phase flow, two-component transport in the free air flow to isothermal liquid water flow in the porous medium with upper boundary conditions defined by a potential evaporation flux when available energy and transfer to the free airflow are limiting or by a critical threshold water pressure when soil water availability is limiting. The latter approach corresponds with the classical Richards equation with mixed boundary conditions. We compare the different approaches on a theoretical level by identifying the underlying simplifications that are made for the different compartments of the system: porous medium, free flow and their interface, and by discussing how processes not explicitly considered are parameterized. Simplifications can be grouped into three sets depending on whether lateral variations in vertical fluxes are considered, whether flow and transport in the air phase in the porous medium are considered, and depending on how the interaction at the interface between the free flow and the porous medium is represented. The consequences of the simplifications are illustrated by numerical simulations in an accompanying paper

    Joint searches between gravitational-wave interferometers and high-energy neutrino telescopes: science reach and analysis strategies

    Get PDF
    Many of the astrophysical sources and violent phenomena observed in our Universe are potential emitters of gravitational waves (GWs) and high-energy neutrinos (HENs). A network of GW detectors such as LIGO and Virgo can determine the direction/time of GW bursts while the IceCube and ANTARES neutrino telescopes can also provide accurate directional information for HEN events. Requiring the consistency between both, totally independent, detection channels shall enable new searches for cosmic events arriving from potential common sources, of which many extra-galactic objects.Comment: 4 pages. To appear in the Proceedings of the 2d Heidelberg Workshop: "High-Energy Gamma-rays and Neutrinos from Extra-Galactic Sources", Heidelberg (Germany), January 13-16, 200

    Numerical study of linear and circular model DNA chains confined in a slit: metric and topological properties

    Full text link
    Advanced Monte Carlo simulations are used to study the effect of nano-slit confinement on metric and topological properties of model DNA chains. We consider both linear and circularised chains with contour lengths in the 1.2--4.8 ÎĽ\mum range and slits widths spanning continuously the 50--1250nm range. The metric scaling predicted by de Gennes' blob model is shown to hold for both linear and circularised DNA up to the strongest levels of confinement. More notably, the topological properties of the circularised DNA molecules have two major differences compared to three-dimensional confinement. First, the overall knotting probability is non-monotonic for increasing confinement and can be largely enhanced or suppressed compared to the bulk case by simply varying the slit width. Secondly, the knot population consists of knots that are far simpler than for three-dimensional confinement. The results suggest that nano-slits could be used in nano-fluidic setups to produce DNA rings having simple topologies (including the unknot) or to separate heterogeneous ensembles of DNA rings by knot type.Comment: 12 pages, 10 figure

    Identifying Community-Engaged Translational Research Collaboration Experience and Health Interests of Community-Based Organizations Outside of Metropolitan Atlanta

    Get PDF
    Background: While rural health research has increased over the last two decades, there is limited understanding of the self-reported health priorities and research interests of rural and suburban community-based representatives and residents. These insights can be used to inform more successful intervention strategies that are responsive to the lived experiences of local residents and leaders who are the gatekeepers to buy-in and sustainability of community engaged research. The Georgia Clinical and Translational Science Alliance, a collaboration between four academic institutions includes a Community Engagement Program (CE) designed to facilitate community-academic research partnerships. This study aimed to assess the health priorities, community-academic research experience, and interests of community respondents outside of Metropolitan Atlanta through the Community Engagement Facilitation Survey (CEFS). Methods: CE Program and Community Steering Board created the CEFS to assess the health topic priorities, research experience, and interests of community-based representatives and community members across the state of Georgia. The 11-item survey was administered (paper and electronic surveys) statewide at community events and professional organization meetings. Descriptive statistics were analyzed, and geospatial mapping was conducted. Data were analyzed in SPSS and Microsoft Excel software systems to clean data and to calculate data counts and percentages. Three maps were created in Tableau Version 19.2 depicting all counties represented by the survey sample superimposed with the counties from which at least one respondent indicated each of the top three health priorities for this sample. Results: Four-hundred six (406) surveys were analyzed, representing 83.6% of rural and suburban Georgia counties. The most frequently identified health priorities and research interests were diabetes, cancer, high blood pressure, and mental health
    • …
    corecore