447 research outputs found

    HAL/S-360 compiler system specification

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    A three phase language compiler is described which produces IBM 360/370 compatible object modules and a set of simulation tables to aid in run time verification. A link edit step augments the standard OS linkage editor. A comprehensive run time system and library provide the HAL/S operating environment, error handling, a pseudo real time executive, and an extensive set of mathematical, conversion, I/O, and diagnostic routines. The specifications of the information flow and content for this system are also considered

    Performance of Vegetative Filters Considering Conservation Practices, Field Slope, and Storm Characteristics

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    Vegetative filter systems are being used nationwide as a management practice for controlling sediment delivery to water bodies, especially in agricultural settings. The installation of vegetative filter systems has increased in agricultural areas in part because of the National Conservation Buffer Initiative implemented by the USDA Natural Resources Conservation Service. Vegetative filters have the effect of retarding the velocity and reducing the sediment transport capacity of water flow (Tollner et al., 1982). As a result, a portion of the sediment in the water flowing through the filter will be deposited thus decreasing the movement of sediment to water bodies

    Price, Yield and Net Income Variability for Selected Field Crops and Counties in Nebraska

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    The primary objective of this study was to establish an empirical estimate of the riskiness of various crops in different regions of Nebraska. For this purpose the variate difference method was used to estimate random variability indexes of prices, yields, and net returns for six Nebraska crops (wheat, soybeans, alfalfa, oats, grain sorghum, corn). The period of analysis included 1957-1976 and one county in each of the eight crop reporting districts was analyzed. Where relevant, both dryland and irrigated alternatives were examined. Most business decision-makers accept more risk only under the conditions that the probability of higher returns accompany risky choices. The authors believe that information in this report can be used by Nebraska farmers when deciding what crops to grow. Variability indexes can provide information regarding the riskiness of the various enterprises. The authors recognize that diversification can also be a useful approach to decrease net return variability along with insurance, commodity programs, and more sophisticated risk reducing strategies

    Wheat and Feed Grains in the Great Plains and Northwest: Study Area Descriptions and State Statistical Summaries

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    The objectives are: (1) To determine individual farm-supply response for alternative product-price relationships and price levels with emphasis on wheat, feed grains, cotton and livestock (2) To estimate aggregate subregional and regional supply functions for major commodities (3) To provide guides for optimum farm organizations and adjustments and attendant adjustments by farm-related businesses and institutions in the Great Plains and Western States

    A Design Aid for Determining Width of Filter Strips

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    Watershed planners need a tool for determining width of filter strips that is accurate enough for developing cost-effective site designs and easy enough to use for making quick determinations on a large number and variety of sites. This study employed the process-based Vegetative Filter Strip Model to evaluate the relationship between filter strip width and trap¬ping efficiency for sediment and water and to produce a design aid for use where specific water quality targets must be met. Model simulations illustrate that relatively narrow filter strips can have high impact in some situations, while in others even a modest impact cannot be achieved at any practical width. A graphical design aid was developed for estimating the width needed to achieve target trapping efficiencies for different pollutants under a broad range of agricultural site conditions. Using the model simulations for sediment and water, a graph was produced containing a family of seven lines that divide the full range of possible relationships between width and trapping efficiency into fairly even increments. Simple rules guide the selection of one line that best describes a given field situation by considering field length and cover management, slope, and soil texture. Relationships for sediment-bound and dissolved pollutants are interpreted from the modeled relationships for sediment and water. Interpolation between lines can refine the results and account for additional variables, if needed. The design aid is easy to use, accounts for several major variables that determine filter strip performance, and is based on a validated, process-based, mathematical model. This design aid strikes a balance between accuracy and utility that fills a wide gap between existing design guides and mathematical models
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