183 research outputs found

    Fiber optic frequency transfer link

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    A reference frequency distribution system is disclosed for transmitting a reference frequency from a reference unit to a remote unit while keeping the reference frequency at the reference unit and the remote unit in phase. A fiber optic cable connects the reference unit to the remote unit. A frequency source at the reference unit produces a reference frequency having an adjustable phase. A fiber optic transmitter at the reference unit modulates a light beam with the reference frequency and transmits the light beam into the fiber optic cable. A 50/50 reflector at the remote unit reflects a first portion of the light beam from the reference unit back into the fiber optic cable to the reference unit. A first fiber optic receiver disposed at the remote unit receives a second portion of the light beam and demodulates the reference frequency to be used at the remote unit. A second fiber optic receiver disposed at the reference unit receives the first portion of the light beam and demodulates a reference frequency component. A phase conjugator is connected to the frequency source for comparing the phase of the reference frequency component to the phase of the reference frequency modulating the light beam being transmitted from the reference unit to maintain a conjugate (anti-symmetric) relationship between the reference frequency component and the reference frequency modulating the light beam where virtually no phase difference exists between the phase of the reference frequency component and the phase of the reference frequency modulating the light beam

    Stabilized fiber-optic frequency distribution system

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    A technique for stabilizing reference frequencies transmitted over fiber-optic cable in a frequency distribution system is discussed. The distribution system utilizes fiber-optic cable as the transmission medium to distribute precise reference signals from a frequency standard to remote users. The stability goal of the distribution system is to transmit a 100-MHz signal over a 22-km fiber-optic cable and maintain a stability of 1 part in 10(17) for 1000-second averaging times. Active stabilization of the link is required to reduce phase variations produced by environmental effects, and is achieved by transmitting the reference signal from the frequency standard to the remote unit and then reflecting back to the reference unit over the same optical fiber. By comparing the phase of the transmitted and reflected signals at the reference unit, phase variations of the remote signal can be measured. An error voltage derived from the phase difference between the two signals is used to add correction phase

    Ornamental plants, 1987: a summary of research

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    Wound healing in street trees / James M. Martin and T. Davis Sydnor -- Evaluation of flowering crabapple susceptibility to apple scab in Ohio—1986 / Elton M. Smith and Sharon A. Treaster -- Fertilizing trees in the landscape: a 15 year evaluation / Elton M. Smith and Sharon A. Treaster -- Juniper injury from Poast / Elton M. Smith and Sharon A. Treaster -- Pre-emergence herbicides for Canna / Elton M. Smith and Sharon A. Treaster -- An evaluation of Cyanazine and Terbacil and metolachlor slow-release herbicide tablets on woody landscape crops / Elton M. Smith and Sharon A. Treaster -- Tolerance of landscape vines to selected pre-emergence herbicides / Elton M. Smith and Sharon A. Treaster -- Influences of supplementary high intensity discharge lighting upon the growth of 'Ringo' geranium and 'Scarletta' begonia plug propagated plants / John C. Peterson and Richard P. Vetanovetz -- Fixed costs of operating field nurseries in Ohio by size of firm and species of plant / Reed D. Taylor, Harold H. Kneen, Elton M. Smith, David E. Hahn and Stanley Uchida -- Costs of producing slow-growing evergreens (Taxus) in the field by size of firm in Ohio / Harold H. Kneen, Reed D. Taylor, Elton M. Smith, David E. Hahn and Stanley Uchida -- Costs of producing deciduous shrubs (Viburnum) in the field by size of firm in Ohio / Reed D. Taylor, Harold H. Kneen, Elton M. Smith, David E. Hahn and Stanley Uchida -- Costs of producing shade trees (Acer rubrum) in the field by size of firm in Ohio / Reed D. Taylor, Harold H. Kneen, Elton M. Smith, David E. Hahn and Stanley Uchid

    Sex‐Related Differences in the Effects of Sports‐Related Concussion: A Review

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    Sports‐related concussion is a serious health challenge, and females are at higher risk of sustaining a sports‐related concussion compared to males. Although there are many studies that investigate outcomes following concussion, females remain an understudied population, despite representing a large proportion of the organized sports community. In this review, we provide a summary of studies that investigate sex‐related differences in outcome following sports‐related concussion. Moreover, we provide an introduction to the methods used to study sex‐related differences after sports‐related concussion, including common clinical and cognitive measures, neuroimaging techniques, as well as biomarkers. A literature search inclusive of articles published to March 2020 was performed using PubMed. The studies were reviewed and discussed with regard to the methods used. Findings from these studies remain mixed with regard to the effect of sex on clinical symptoms, concussion‐related alterations in brain structure and function, and recovery trajectories. Nonetheless, there is initial evidence to suggest that sex‐related differences following concussion are important to consider in efforts to develop objective biomarkers for the diagnosis and prognosis of concussion. Additional studies on this topic are, however, clearly needed to improve our understanding of sex‐related differences following concussion, as well as to understand their neurobiological underpinnings. Such studies will help pave the way toward more personalized clinical management and treatment of sports‐related concussion

    Trying Cases in the Media: Legal Ethics, Fair Trials and Free Press

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    The 2000 symposium consisted of a panel discussion which used role-playing and a mock trial to highlight the issues of lawyer/litigant comments to the press before and during trial and the dilemma of journalists confronted by court demands for documents, testimony, or sources of information obtained in the course of gathering news on pending trials. Participants included: As United States Attorney for the Eastern District of Freedonia: John Douglas, Associate Professor of Law at the University of Richmond. As Freedonia criminal defense lawyer: Gerald Zerkin, Private Defense Attorney. As investigative journalist: Steve Nash, Associate Professor of Journalism at the University of Richmond. As federal judge: Judge Margaret P. Spencer, Virginia Circuit Court Judge. As media attorney: Craig Thomas Merritt, Attorney. As first amendment attorney: J. Joshua Wheeler, Attorney and Director of Programs for the Thomas Jefferson Center for the Protection of Free Expression, and adjunct professor at University of Virginia. As Chief Justice: Paul D. Carrington, The Chadwick Professor of Law at Duke University. As Associate Justices of the United States Supreme Court: C. Thomas Dienes, Patricia Roberts Harris Professor of Law at George Washington University\u27s Law School; John E. Nowak, David C. Baum Professor of Law at the University of Illinois; Molly Delea, third-year law student, University of Richmond School of Law; Kate Murray, third-year law student, University of Richmond School of Law; Thomas Queen, third-year law student, University of Richmond School of Law; and Courtney Sydnor, third-year law student, University of Richmond School of Law

    Ornamental plants, 1983: a summary of research

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    Capital requirements for establishing container nurseries in Ohio - 1982 / Harold H. Kneen, Reed D. Taylor, David E. Hahn, and Elton M. Smith -- Production costs of operating container nurseries in Ohio - 1982 / Harold H. Kneen, Reed D. Taylor, David E. Hahn, and Elton M. Smith -- Pigmented polyethylene films for nursery crop storage / John A. Wynstra and Elton M. Smith -- Micropropagation of Ajuga reptans 'Burgundy Glow' / R. Daniel Lineberger and Audrey Wanstreet -- Effects of fertilizer in the propagation medium and extended photoperiod on growth of Acer rubrum 'Red Sunset' cuttings / Steven M. Still and Bryce H. Lane -- Area of weed control from a single herbicide tablet / M. A. Ruizzo, E. M. Smith, and S. F. Gorske -- Slow release herbicide formulations for container grown landscape crops / M. A. Ruizzo, E. M. Smith, and S. F. Gorske -- Effects of pre-emergence herbicides on selected herbaceous perennials / Elton M. Smith, Gary Gibson, and Sharon A. Treaster -- Controlling weeds in garden lily, gladiolus, and dahlia with pre-emergence herbicides / Elton M. Smith and Sharon A. Treaster -- Root pruning landscape plants produced on sand capillary beds / Elton M. Smith and Sharon A. Treaster -- Genetic variation in wound response among cultivars of Acer platanoides L. / Peter W. Gallagher and T. Davis Sydnor -- A preliminary host preference study for fall webworm (Hyphantria cunea Drury) / T. Davis Sydnor and Daniel Herms -- Evaluation of flowering crabapple susceptibility to apple scab in Ohio - 1982 / Elton M. Smit
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