1,733 research outputs found

    Simulating Operations at a Spaceport

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    SPACESIM is a computer program for detailed simulation of operations at a spaceport. SPACESIM is being developed to greatly improve existing spaceports and to aid in designing, building, and operating future spaceports, given that there is a worldwide trend in spaceport operations from very expensive, research- oriented launches to more frequent commercial launches. From an operational perspective, future spaceports are expected to resemble current airports and seaports, for which it is necessary to resolve issues of safety, security, efficient movement of machinery and people, cost effectiveness, timeliness, and maximizing effectiveness in utilization of resources. Simulations can be performed, for example, to (1) simultaneously analyze launches of reusable and expendable rockets and identify bottlenecks arising from competition for limited resources or (2) perform what-if scenario analyses to identify optimal scenarios prior to making large capital investments. SPACESIM includes an object-oriented discrete-event-simulation engine. (Discrete- event simulation has been used to assess processes at modern seaports.) The simulation engine is built upon the Java programming language for maximum portability. Extensible Markup Language (XML) is used for storage of data to enable industry-standard interchange of data with other software. A graphical user interface facilitates creation of scenarios and analysis of data

    Film Boiling Heat Transfer From An Oscillating Sphere

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    An experimental investigation has been undertaken to determine the effect of oscillation of the heat transfer surface on turbulent film boiling heat transfer. A transient technique was used to calculate the heat flux from copper spheres of 1 in., 3/4 in., and 1/2 in. dia. In all tests, saturated liquid nitrogen at atmospheric pressure was used as the boiling fluid. The data obtained were found to be in good agreement with published theory at zero frequency. The range of frequencies studied was from zero to approximately 12 cps at peak-to-peak amplitudes of 2 in. and 1 in., i.e., at amplitude-to-diameter ratios of 1.00, 1.34, 2.00, 2.67, and 4.00. It was determined that oscillation of the heat transfer surface considerably increases the heal flux for a given temperature difference over that for natural convection film boiling. The results were correlated with a maximum deviation of +35, -17 percent. The correlation equation showed that the Nusselt number was proportional to the vibrational Froude number to the 2/3 power. Tests were conducted with spheres having a corroded surface, a glass-bead-peened surface and a Teflon-coated surface. The results show that the turbulent film boiling from an oscillating sphere is independent of the condition of the heat transfer surface over the range of frequencies and amplitudes tested. © 1969 by ASME

    Performance of strawberry varieties in Missouri

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    Cover title

    Strawberry varieties for Missouri

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    Cover title.Includes bibliographical references

    Phylogenetic simulation of promoter evolution: estimation and modeling of binding site turnover events and assessment of their impact on alignment tools

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    Phylogenetic simulation of promoter evolution were used to analyze functional site turnover in regulatory sequences

    Relating Baseball Seam Height to Carry Distance

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    AbstractPast work has shown large variation in the drag of baseballs. Little is known concerning the causes of variation in ball drag. Ball diameter, weight, seam height, surface roughness, and shape influence lift and drag, and therefore carry distance. The aim of this work was to quantify the effect of seam height and roundness on ball lift and drag, which, to our understanding, has never been done outside of a wind tunnel. A bespoke, non-contact, ball surface profiler, was used to measure ball radius, including seam height. The profiles were analyzed to describe ball roundness and seam height separately. Balls with three different seam heights were projected in an enclosed stadium 102-122 m (describing a typical fly ball). Redundant radar devices were used to measure launch angle, speed, and flight paths. High speed video was used to confirm launch angle and ball spin rate. Hit distance was verified with a physical tape measure. The ball's roundness influenced the effective height of a seam. Measurements of the non-seam area of a ball were necessary to characterize the seams of a ball. A strong correlation was observed between seam height and a ball's drag coefficient. Lift, however, was not sensitive to seam height or ball shape

    PCN46 HEALTH CARE EXPENDITURES, DISABILITY DAYS, AND RESOURCE UTILIZATION ASSOCIATED WITH CANCER IN EMPLOYER SETTINGS IN THE UNITED STATES

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    Utilization of Genomic Signatures to Identify Phenotype-Specific Drugs

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    Genetic and genomic studies highlight the substantial complexity and heterogeneity of human cancers and emphasize the general lack of therapeutics that can match this complexity. With the goal of expanding opportunities for drug discovery, we describe an approach that makes use of a phenotype-based screen combined with the use of multiple cancer cell lines. In particular, we have used the NCI-60 cancer cell line panel that includes drug sensitivity measures for over 40,000 compounds assayed on 59 independent cells lines. Targets are cancer-relevant phenotypes represented as gene expression signatures that are used to identify cells within the NCI-60 panel reflecting the signature phenotype and then connect to compounds that are selectively active against those cells. As a proof-of-concept, we show that this strategy effectively identifies compounds with selectivity to the RAS or PI3K pathways. We have then extended this strategy to identify compounds that have activity towards cells exhibiting the basal phenotype of breast cancer, a clinically-important breast cancer characterized as ER-, PR-, and Her2- that lacks viable therapeutic options. One of these compounds, Simvastatin, has previously been shown to inhibit breast cancer cell growth in vitro and importantly, has been associated with a reduction in ER-, PR- breast cancer in a clinical study. We suggest that this approach provides a novel strategy towards identification of therapeutic agents based on clinically relevant phenotypes that can augment the conventional strategies of target-based screens
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