2,172 research outputs found

    Some Culp Family Members in the Civil War

    Full text link
    In the 1860s Gettysburg had a population of around 2,400. The Culps had lived there since 1787, the year Christopher Culp purchased the farm, located on the east end of town, with its western boundry starting at Baltimore St. between Breckenridge and South Streets, going northeast to South Stratton St. and Wall Alley East, then on to East Middle St. between South Stratton and Liberty Streets. The town more or less ended at the farm boundary. Prominent on the farm and southeast of town was Culp\u27s Hill. Five generations of Culps had lived in Gettysburg by the time of the battle. [excerpt

    Hypersonic Flight Mechanics

    Get PDF
    The effects of aerodynamic forces on trajectories at orbital speeds are discussed in terms of atmospheric models. The assumptions for the model are spherical symmetry, nonrotating, and an exponential atmosphere. The equations of flight, and the performance in extra-atmospheric flight are discussed along with the return to the atmosphere, and the entry. Solutions of the exact equations using directly matched asymptotic expansions are presented

    Solution of the exact equations for three-dimensional atmospheric entry using directly matched asymptotic expansions

    Get PDF
    The problem of determining the trajectories, partially or wholly contained in the atmosphere of a spherical, nonrotating planet, is considered. The exact equations of motion for three-dimensional, aerodynamically affected flight are derived. Modified Chapman variables are introduced and the equations are transformed into a set suitable for analytic integration using asymptotic expansions. The trajectory is solved in two regions: the outer region, where the force may be considered a gravitational field with aerodynamic perturbations, and the inner region, where the force is predominantly aerodynamic, with gravity as a perturbation. The two solutions are matched directly. A composite solution, valid everywhere, is constructed by additive composition. This approach of directly matched asymptotic expansions applied to the exact equations of motion couched in terms of modified Chapman variables yields an analytical solution which should prove to be a powerful tool for aerodynamic orbit calculations

    Optimum three-dimensional atmospheric entry from the analytical solution of Chapman's exact equations

    Get PDF
    The general solution for the optimum three-dimensional aerodynamic control of a lifting vehicle entering a planetary atmosphere is developed. A set of dimensionless variables, modified Chapman variables, is introduced. The resulting exact equations of motion, referred to as Chapman's exact equations, have the advantage that they are completely free of the physical characteristics of the vehicle. Furthermore, a completely general lift-drag relationship is used in the derivation. The results obtained apply to any type of vehicle of arbitrary weight, dimensions and shape, having an arbitrary drag polar, and entering any planetary atmosphere. The aerodynamic controls chosen are the lift coefficient and the bank angle. General optimum control laws for these controls are developed. Several earlier particular solutions are shown to be special cases of this general result. Results are valid for both free and constrained terminal position

    Platelet-Rich Plasma Injection With Percutaneous Needling for Recalcitrant Lateral Epicondylitis: Comparison of Tenotomy and Fenestration Techniques.

    Get PDF
    Background: Recalcitrant lateral epicondylitis (LE) is a common debilitating condition, with numerous treatment options of varying success. An injection of platelet-rich plasma (PRP) has been shown to improve LE, although it is unclear whether the method of needling used in conjunction with a PRP injection is of clinical importance. Purpose: To determine whether percutaneous needle tenotomy is superior to percutaneous needle fenestration when each is combined with a PRP injection for the treatment of recalcitrant LE. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 93 patients with recalcitrant LE were treated with a PRP injection and percutaneous needle fenestration (n = 45) or percutaneous needle tenotomy (n = 48) over a 5-year study interval. Preoperative patient data, including visual analog scale for pain (VAS-P), Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), and Patient-Rated Tennis Elbow Evaluation (PRTEE) scores and grip strength, were obtained from a chart review and compared with postoperative values obtained prospectively. Secondary outcomes included the incidence of complications, need for additional interventions, return to work, and patient satisfaction. Results: At a mean follow-up of 40 months, significant improvements in VAS-P (mean, -6.1; 95% CI, -6.8 to -5.5; P \u3c .0001), QuickDASH (mean, -46; 95% CI, -52 to -40; P \u3c .0001), and PRTEE (mean, -57; 95% CI, -64 to -50; P \u3c .0001) scores and grip strength (mean, +6.1 kg; 95% CI, 4.9 to 7.3; P \u3c .0001) were observed across the entire study cohort, with no significant differences noted between the fenestration and tenotomy groups. Nine of 45 patients (22%) underwent additional procedures to treat recurrent symptoms in the fenestration group compared with 5 of 48 patients (10%) in the tenotomy group (P = .05). No complications occurred in any patients, and no patients expressed dissatisfaction with their treatment course. Conclusion: A PRP injection with concomitant percutaneous needling is an effective treatment for recalcitrant LE, with sustained improvements in pain, strength, and function demonstrated at a mean follow-up of longer than 3 years. Although the method of concomitant needling does not appear to have a significant effect on treatment outcomes, more aggressive needle tenotomy is less likely to require conversion to open tenotomy than needle fenestration in the short term to midterm

    The Plasma Interaction Experiment (PIX) description and test program

    Get PDF
    The plasma interaction experiment (PIX) is a battery powered preprogrammed auxiliary payload on the LANDSAT-C launch. This experiment is part of a larger program to investigate space plasma interactions with spacecraft surfaces and components. The varying plasma densities encountered during available telemetry coverage periods are deemed sufficient to determine first order interactions between the space plasma environment and the biased experimental surfaces. The specific objectives of the PIX flight experiment are to measure the plasma coupling current and the negative voltage breakdown characteristics of a solar array segment and a gold plated steel disk. Measurements will be made over a range of surface voltages up to plus or minus kilovolt. The orbital environment will provide a range of plasma densities. The experimental surfaces will be voltage biased in a preprogrammed step sequence to optimize the data returned for each plasma region and for the available telemetry coverage

    A systematic review of criteria used to report complications in soft tissue and oncologic surgical clinical research studies in dogs and cats.

    Get PDF
    ObjectiveTo evaluate reporting of surgical complications and other adverse events in clinical research articles describing soft tissue and oncologic surgery in dogs and cats.Study designSystematic literature review.SampleEnglish-language articles describing soft tissue and oncologic surgeries in client-owned dogs and cats published in peer-reviewed journals from 2013 to 2016.MethodsCAB, AGRICOLA, and MEDLINE databases were searched for eligible articles. Article characteristics relevant to complications were abstracted and summarized, including reported events, definitions, criteria used to classify events according to severity and time frame, and relevant citations.ResultsOne hundred fifty-one articles involving 10 522 animals were included. Canine retrospective case series of dogs predominated. Ninety-two percent of articles mentioned complications in study results, but only 7.3% defined the term complication. Articles commonly described complications according to time frame and severity, but terminology and classification criteria were highly variable, conflicting between studies, or not provided. Most (58%) reported complications could have been graded with a published veterinary adverse event classification scheme, although common intraoperative complications were notable exceptions.ConclusionDefinitions and criteria used to classify and report soft tissue and oncologic surgical complications are often absent, incomplete, or contradictory among studies.Clinical significanceLack of consistent terminology contributes to inadequate communication of important information about surgical complications. Standardization of terminology and consistency in severity scoring will improve comparative evaluation of clinical research results
    corecore