597 research outputs found

    Hydraulic Characteristics of Rills

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    Rill density and rill flow rates were determined during rainfall simulation tests conducted at 11 sites located throughout the eastern United States. A mean rill density of 1.0 rills/m was found for the study locations. From measurements of the relative distribution of flow rates, a procedure is identified for partitioning flow between individual rills. Regression equations were developed for relating rill width and hydraulic roughness coefficients to flow rate. Equations were also derived for predicting mean flow velocity from visually determined measurements of advance velocity. Information reported in this study can be used to estimate hydraulic characteristics of rills

    Managing Manure Phosphorus

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    Manure, a renewable resource, contains nutrients that are needed for plant growth. Phosphorus in manure can be utilized for crop production as a substitute for synthetic fertilizers. Phosphorus in manure can also be a source of surface or ground water contamination if not used properly. Increased P concentration can lead to eutrophication of surface waters. Management systems need to be developed to utilize manure P effectively without adverse effects on the environment

    NUTRIENTS IN RUNOFF FOLLOWING THE APPLICATION OF SWINE MANURE TO INTERRILL AREAS

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    The P content of swine manure can be reduced through the addition of feed supplements or the use of selected corn hybrids. This study was conducted to compare interrill runoff losses of P and N from three soils following the application of swine manure obtained from selected diets. The soils used in this investigation included a Hersh sandy loam, Pierre silty clay, and Sharpsburg silt loam. Simulated rainfall was applied during both initial and wet runs to a soil pan on which swine manure produced from low phytate corn (LPC), phytase added to the diet (PHY), or a traditional corn diet (TCD) was added. Additional experimental treatments included inorganic fertilizer and an untreated check. For the initial rainfall simulation run, concentrations of dissolved P, bioavailable P, and Total P were greater for the fertilizer treatment than any of the manure treatments. Use of manure from a LPC diet generally did not result in a reduction in N and P concentrations in runoff when compared with the TCD. Concentrations and total amounts of nutrients transported in runoff were affected by soil type. Changing the TCD to LPC and PHY diets to reduce the P content of manure did not significantly affect the total amounts of DP, BAP, or Total P transported in runoff, when simulated rainfall was applied soon after manure application

    Manure Impacts on Interrill Erosion

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    This study was conducted to measure runoff and erosion from interrill areas as affected by the long-term application of manure and fertilizer to a Tripp sandy loam soil located near Mitchell, Nebraska. Soil that had been removed from the top 0.1 m of the soil profile was placed in a 1 m2 soil pan. Rainfall was then applied to the soil pan during initial and wet simulation events. Total runoff was similar on the manure and no-manure treatments. The long-term application of manure (55 years) at a rate of 27 Mg ha-1 (wet basis) per year did not significantly influence interrill erosion on this sandy loam soil. Interrill erosion was also unaffected by the addition of manure immediately before rainfall simulation tests to soils on which manure had been applied in previous years. No significant differences in runoff and erosion were found among plots receiving varying amounts of fertilizer. Selected soil properties were generally unaffected by the varying manure and fertilizer treatments

    Developing Leadership for Creative Efforts: A Preface

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    Michael D. Mumford is the George Lynn Cross distinguished research professor of psychology at the University of Oklahoma where he directs the Center for Applied Social Research. He received his doctoral degree from the University of Georgia in 1983 in the fields of industrial and organizational psychology and psychometrics. He is a fellow of the American Psychological Association (Divisions 3, 5, 10, 14), the Society for Industrial and Organizational Psychology, and the American Psychological Society. He has written more than 270 articles on leadership, creativity, innovation, planning, and ethics. He has served as senior editor of The Leadership Quarterly, and he sits on the editorial boards of the Creativity Research Journal, The Journal of Creative Behavior, IEEE Transactions on Engineering Management, and Ethics and Behavior, among other journals. He has served as principal investor on grants totaling more than US$30 million from the National Science Foundation, The National Institute of Health, the Department of Defense, the Department of Labor, and the Department of State. He is a recipient of the Society for Industrial and Organizational Psychology’s M. Scott Myers Award for Applied Research in the Workplace.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    From Lunar Regolith to Fabricated Parts: Technology Developments and the Utilization of Moon Dirt

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    The U.S. Space Exploration Policy has as a cornerstone the establishment of an outpost on the moon. This lunar outpost wil1 eventually provide the necessary planning, technology development, testbed, and training for manned missions in the future beyond the Moon. As part of the overall activity, the National Aeronautics and Space Administration (NASA) is investigating how the in situ resources can be utilized to improve mission success by reducing up-mass, improving safety, reducing risk, and bringing down costs for the overall mission. Marshall Space Flight Center (MSFC), along with other NASA centers, is supporting this endeavor by exploring how lunar regolith can be mined for uses such as construction, life support, propulsion, power, and fabrication. An infrastructure capable of fabrication and nondestructive evaluation will be needed to support habitat structure development and maintenance, tools and mechanical parts fabrication, as well as repair and replacement of space-mission hardware such as life-support items, vehicle components, and crew systems, This infrastructure will utilize the technologies being developed under the In Situ Fabrication and Repair (ISFR) element, which is working in conjunction with the technologies being developed under the In Situ Resources Utilization (ISRU) element, to live off the land. The ISFR Element supports the Space Exploration Initiative by reducing downtime due to failed components; decreasing risk to crew by recovering quickly from degraded operation of equipment; improving system functionality with advanced geometry capabilities; and enhancing mission safety by reducing assembly part counts of original designs where possible. This paper addresses the need and plan for understanding the properties of the lunar regolith to determine the applicability of using this material in a fabrication process. This effort includes the development of high fidelity simulants that will be used in fabrication processes on the ground to drive down risk and increase the Technology Readiness Level (TRL) prior to implementing this capability on the moon. Also discussed in this paper is the on-going research using Electron Beam Melting (EBM) technology as a possible solution to manufacturing parts and spares on the Moon's surface

    Hydraulic resistance to overland flow on surfaces with partially submerged vegetation

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96239/1/wrcr13661.pd
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