317 research outputs found

    A Comparison of Chemical Applications Using Micromax Spinners and Conventional Sprayer Tips

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    The problem of this study was to determine the effects of Poast chemical sprayed on fall grasses and weeds and their percents of kill on test strips by using a conventional hydraulic sprayer with model 8003 tips and by using a C.D.A. micromax spinner at 2000 R.P.H and at 5000 R.P.H

    New multivariable capabilities of the INCA program

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    The INteractive Controls Analysis (INCA) program was developed at NASA's Goddard Space Flight Center to provide a user friendly, efficient environment for the design and analysis of control systems, specifically spacecraft control systems. Since its inception, INCA has found extensive use in the design, development, and analysis of control systems for spacecraft, instruments, robotics, and pointing systems. The (INCA) program was initially developed as a comprehensive classical design analysis tool for small and large order control systems. The latest version of INCA, expected to be released in February of 1990, was expanded to include the capability to perform multivariable controls analysis and design

    ASTEC and MODEL: Controls software development at Goddard Space Flight Center

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    The ASTEC (Analysis and Simulation Tools for Engineering Controls) software is under development at the Goddard Space Flight Center (GSFC). The design goal is to provide a wide selection of controls analysis tools at the personal computer level, as well as the capability to upload compute-intensive jobs to a mainframe or supercomputer. In the last three years the ASTEC (Analysis and Simulation Tools for Engineering Controls) software has been under development. ASTEC is meant to be an integrated collection of controls analysis tools for use at the desktop level. MODEL (Multi-Optimal Differential Equation Language) is a translator that converts programs written in the MODEL language to FORTRAN. An upgraded version of the MODEL program will be merged into ASTEC. MODEL has not been modified since 1981 and has not kept with changes in computers or user interface techniques. This paper describes the changes made to MODEL in order to make it useful in the 90's and how it relates to ASTEC

    Phosphorus indexing for cropland: Overview and basic concepts of the Iowa phosphorus index

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    Excessive phosphorus (P) loss from soils impairs surface water resources. An assessment tool or index has been proposed to identify fields with high potential risk of P delivery. The P index integrates P source and transport factors into a decision making process that may lead to changes in current P management and soil conservation practices. The index recognizes that a single soil P threshold alone is not an appropriate evaluation factor because of the varying conditions across fields. Although most indices being developed in the United States include similar factors, source and transport characteristics are considered in various ways to best address the variable conditions across regions. The Iowa P index reflects conditions that predominate under grain-crop production systems, considers source factors in a multiplicative manner within three main transport mechanisms, and approximates loads of P likely to enter and become available to aquatic ecosystems. An erosional component considers sheet and rill erosion, P enrichment, total soil P, buffers, sediment delivery, distance to a stream, and the long term biotic availability of particulate P in lake ecosystems. A runoff component considers water runoff based on a modification of the runoff curve number (RCN), soil-test P (STP), rate, time, and method of P application. An internal drainage component considers the presence of tiles, water flow to tile lines, subsurface recharge from subsurface flow, and soil-test P. When the erosion risk is high, the index weighs particulate P loss heavily compared with dissolved P loss, and emphasizes long-term processes comparatively more than short-term processes. This P assessment tool helps identify alternative P and soil conservation management options for reducing total P delivery from fields to surface water resources

    Lake-size dependency of wind shear and convection as controls on gas exchange

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    High-frequency physical observations from 40 temperate lakes were used to examine the relative contributions of wind shear (u*) and convection (w*) to turbulence in the surface mixed layer. Seasonal patterns of u* and w* were dissimilar; u* was often highest in the spring, while w * increased throughout the summer to a maximum in early fall. Convection was a larger mixed-layer turbulence source than wind shear (u */w*-1 for lakes* and w* differ in temporal pattern and magnitude across lakes, both convection and wind shear should be considered in future formulations of lake-air gas exchange, especially for small lakes. © 2012 by the American Geophysical Union.Jordan S. Read, David P. Hamilton, Ankur R. Desai, Kevin C. Rose, Sally MacIntyre, John D. Lenters, Robyn L. Smyth, Paul C. Hanson, Jonathan J. Cole, Peter A. Staehr, James A. Rusak, Donald C. Pierson, Justin D. Brookes, Alo Laas, and Chin H. W

    Improving the diagnosis and treatment of urinary tract infection in young children in primary care:results from the ‘DUTY’ prospective diagnostic cohort study

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    PURPOSE Up to 50% of urinary tract infections (UTIs) in young children are missed in primary care. Urine culture is essential for diagnosis, but urine collection is often difficult. Our aim was to derive and internally validate a 2-step clinical rule using (1) symptoms and signs to select children for urine collection; and (2) symptoms, signs, and dipstick testing to guide antibiotic treatment. METHODS We recruited acutely unwell children aged under 5 years from 233 primary care sites across England and Wales. Index tests were parent-reported symptoms, clinician-reported signs, urine dipstick results, and clinician opinion of UTI likelihood (clinical diagnosis before dipstick and culture). The reference standard was microbiologically confirmed UTI cultured from a clean-catch urine sample. We calculated sensitivity, specificity, and area under the receiver operator characteristic (AUROC) curve of coefficient-based (graded severity) and points-based (dichotomized) symptom/sign logistic regression models, and we then internally validated the AUROC using bootstrapping. RESULTS Three thousand thirty-six children provided urine samples, and culture results were available for 2,740 (90%). Of these results, 60 (2.2%) were positive: the clinical diagnosis was 46.6% sensitive, with an AUROC of 0.77. Previous UTI, increasing pain/crying on passing urine, increasingly smelly urine, absence of severe cough, increasing clinician impression of severe illness, abdominal tenderness on examination, and normal findings on ear examination were associated with UTI. The validated coefficient- and points-based model AUROCs were 0.87 and 0.86, respectively, increasing to 0.90 and 0.90, respectively, by adding dipstick nitrites, leukocytes, and blood. CONCLUSIONS A clinical rule based on symptoms and signs is superior to clinician diagnosis and performs well for identifying young children for noninvasive urine sampling. Dipstick results add further diagnostic value for empiric antibiotic treatment

    Different paths to the modern state in Europe: the interaction between domestic political economy and interstate competition

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    Theoretical work on state formation and capacity has focused mostly on early modern Europe and on the experience of western European states during this period. While a number of European states monopolized domestic tax collection and achieved gains in state capacity during the early modern era, for others revenues stagnated or even declined, and these variations motivated alternative hypotheses for determinants of fiscal and state capacity. In this study we test the basic hypotheses in the existing literature making use of the large date set we have compiled for all of the leading states across the continent. We find strong empirical support for two prevailing threads in the literature, arguing respectively that interstate wars and changes in economic structure towards an urbanized economy had positive fiscal impact. Regarding the main point of contention in the theoretical literature, whether it was representative or authoritarian political regimes that facilitated the gains in fiscal capacity, we do not find conclusive evidence that one performed better than the other. Instead, the empirical evidence we have gathered lends supports to the hypothesis that when under pressure of war, the fiscal performance of representative regimes was better in the more urbanized-commercial economies and the fiscal performance of authoritarian regimes was better in rural-agrarian economie
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