1,597 research outputs found

    Some Culp Family Members in the Civil War

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    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

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    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

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    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

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    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

    SUBSTRATE-ATTACHED GLYCOPROTEINS MEDIATING ADHESION OF NORMAL AND VIRUS-TRANSFORMED MOUSE FIBROBLASTS

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    When BALB/c 3T3, simian virus 40 (SV40)-transformed 3T3 (SVT2), and revertant variants of the transformed cells are removed by EGTA treatment from the substrate on which they were grown, they leave behind a layer of glycoprotein which has been characterized biochemically (Terry, A. H. and L. A. Culp. 1974. Biochemistry. 13:414.)—substrate-attached material (SAM). The influence of SAM from normal and from transformed cells on cellular attachment to the substrate, morphology, movement, and growth has been examined. All three cell types displayed a 30% higher plating efficiency when grown on 3T3 SAM. The morphology of SVT2 colonies and of individual SVT2 cells was dramatically affected by growth on 3T3 SAM—the cells (a) were more highly spread on the substrate, (b) resisted crawling over neighboring cells, and (c) resisted movement away from the edge of colonies; SVT2 SAM was not effective in causing these changes. A cell-to-substrate attachment assay using thymidine-radiolabeled cells and untreated or SAM-coated cover slips was developed. SVT2 cells attached to 3T3 SAM- or SVT2 SAM-coated cover slips with a faster initial rate and to a higher saturation level than to untreated substrate, whereas 3T3 and revertant cells exhibited no preference; there was no species specificity in these cell-substrate attachment phenomena. Trypsin-released cells attached much more slowly than EGTA-released cells. 3T3 SAM, however, was not effective in lowering the saturation density of mass cultures of virus-transformed cells. These experiments suggest that the substrate-attached glycoproteins of normal cells affect the cellular adhesivity, morphology, movement, and perhaps growth patterns of virus-transformed cells—i.e., causing partial reversion of these properties of transformed cells to those found in contact-inhibited fibroblasts. A model for the involvement of substrate-attached glycoproteins in cell-to-substrate adhesion, and possibly cell-to-cell adhesion, has been proposed

    Analytic theory of orbit contraction

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    The motion of a satellite in orbit, subject to atmospheric force and the motion of a reentry vehicle are governed by gravitational and aerodynamic forces. This suggests the derivation of a uniform set of equations applicable to both cases. For the case of satellite motion, by a proper transformation and by the method of averaging, a technique appropriate for long duration flight, the classical nonlinear differential equation describing the contraction of the major axis is derived. A rigorous analytic solution is used to integrate this equation with a high degree of accuracy, using Poincare's method of small parameters and Lagrange's expansion to explicitly express the major axis as a function of the eccentricity. The solution is uniformly valid for moderate and small eccentricities. For highly eccentric orbits, the asymptotic equation is derived directly from the general equation. Numerical solutions were generated to display the accuracy of the analytic theory

    Temperature measurements behind reflected shock waves in air

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    A radiometric method for the measurement of gas temperature in self-absorbing gases has been applied in the study of shock tube generated flows. This method involves making two absolute intensity measurements at identical wavelengths, but for two different pathlengths in the same gas sample. Experimental results are presented for reflected shock waves in air at conditions corresponding to incident shock velocities from 7 to 10 km/s and an initial driven tube pressure of 1 torr. These results indicate that, with this technique, temperature measurements with an accuracy of + or - 5 percent can be carried out. The results also suggest certain facility related problems

    Evaluation of Weight Change During Carboplatin Therapy in Dogs With Appendicular Osteosarcoma.

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    BackgroundThe prevalence of cancer cachexia in veterinary medicine has not been studied widely, and as of yet, no definitive diagnostic criteria effectively assess this syndrome in veterinary patients.Objectives(1) To determine the patterns of weight change in dogs with appendicular osteosarcoma treated with amputation and single-agent carboplatin during the course of adjuvant chemotherapy; and (2) to determine whether postoperative weight change is a negative prognostic indicator for survival time in dogs with osteosarcoma.AnimalsEighty-eight dogs diagnosed with appendicular osteosarcoma. Animals were accrued from 3 veterinary teaching hospitals.MethodsRetrospective, multi-institutional study. Dogs diagnosed with appendicular osteosarcoma and treated with limb amputation followed by a minimum of 4 doses of single-agent carboplatin were included. Data analyzed in each patient included signalment, tumor site, preoperative serum alkaline phosphatase activity (ALP), and body weight (kg) at each carboplatin treatment.ResultsA slight increase in weight occurred over the course of chemotherapy, but this change was not statistically significant. Weight change did not have a significant effect on survival. Institution, patient sex, and serum ALP activity did not have a significant effect on survival.Conclusions and clinical importanceWeight change was not a prognostic factor in these dogs, and weight loss alone may not be a suitable method of determining cancer cachexia in dogs with appendicular osteosarcoma
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