4,518 research outputs found

    Surge valve assembly

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    A surge irrigation system includes a main inlet pipe configured to be coupled to a source of pressurized water. The main inlet pipe is coupled to a flow meter for the purpose of improving furrow irrigation. The system further includes two independent, valve-actuated and controlled pipe arm segments extending from the main inlet pipe. One of the pipe arm segments extends toward a first irrigation zone in a field, and the second pipe arm segment extends toward the second irrigation zone in the field. The system further includes water advance sensors for the purpose of improving a surge irrigation program for an improved autonomous and parameter-setting operation. Additionally the controller, sensor and interface use radio communication

    Development of the Mask Scentometer, a Comparison of Ambient Odor Assessment Methods, and their Application in Ground Truthing Atmospheric Dispersion Models

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    This dissertation is organized as four stand-alone papers. Paper No. 1 describes the development of the Mask Scentometer and reports dilution ratios measured during use by twelve different people. Dilution ratios at the Mask Scentometer’s five dilution-to-threshold (D/T) settings were found to be 0.35, 1, 2, 4.5 and 18. In Paper No.’s 2 and 4, ambient odor assessment methods were compared in both controlled laboratory conditions and in the field. Laboratory analysis of ambient air samples using dynamic triangular forced-choice olfactometry (DTFCO) did not correlate well with any of the ambient odor assessment methods. Average intensity-predicted D/T was roughly five times higher than D/T measured using a Nasal Ranger®, and D/T obtained using a Nasal Ranger® was roughly two to five times higher than corresponding D/T from a Mask Scentometer. In Paper 3, odor intensity ratings and Mask Scentometer readings were used to calibrate the AERMOD dispersion model for predicting odor concentrations downwind of area sources. Dispersion of odor from a swine waste treatment lagoon and two cattle feedlots was modeled with AERMOD and the predictions were compared to the observations using a statistical approach to develop scaling factors. These were found to be 12 for odor intensity and 0.15 for the Mask Scentometer (although a scaling factor between 0.5 and 0.7 is also justified). Random effects and autocorrelation were found to be significant in ambient odor assessment data. In Paper 4, the dispersion of odors from a swine production building complex was studied. CALPUFF and AERMOD were used to predict short-time-step (one minute) odor concentrations. Source emission measurements and meteorological data were collected to coincide with ambient odor measurements obtained using the Nasal Ranger®, Mask Scentometer, field odor intensity ratings, and DTFCO. In general, odor concentrations predicted using CALPUFF were found to be about twice those predicted by AERMOD. Model predictions agreed best with the readings from the Nasal Ranger® and Mask Scentometer; and both of these ambient odor assessment methods are suited for ground truthing AERMOD and CALPUFF, although some model scaling factor adjustment is needed. Adviser: Dennis D. Schult

    Impact of Vegetative Treatment Systems on Multiple Measures of Antibiotic Resistance in Agricultural Wastewater

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    Wastewater is an important vector of antibiotic resistant bacteria and antibiotic resistance genes (ARB/G). While there is broad agreement that ARB/G from agricultural (ag) wastewaters can be transported through the environment and may contribute to untreatable infectious disease in humans and animals, there remain large knowledge gaps surrounding applied details on the types and amounts of ARB/G associated with different agricultural wastewater treatment options and different ag production systems. This study evaluates a vegetative treatment system (VTS) built to treat the wastewater from a beef cattle feedlot. Samples were collected for three years, and plated on multiple media types to enumerate tetracycline and cefotaxime-resistant bacteria. Enterobacteriaceae isolates (n = 822) were characterized for carriage of tetracycline resistance genes, and E. coli isolates (n = 673) were phenotyped to determine multi-drug resistance (MDR) profiles. Tetracycline resistance in feedlot runoff wastewater was 2-to-3 orders of magnitude higher compared to rainfall runoff from the VTS fields, indicating efficacy of the VTA for reducing ARB over time following wastewater application. Clear differences in MDR profiles were observed based on the specific media on which a sample was plated. This result highlights the importance of method, especially in the context of isolate-based surveillance and monitoring of ARB in agricultural wastewaters

    Development of the Mask Scentometer, a Comparison of Ambient Odor Assessment Methods, and their Application in Ground Truthing Atmospheric Dispersion Models

    Get PDF
    This dissertation is organized as four stand-alone papers. Paper No. 1 describes the development of the Mask Scentometer and reports dilution ratios measured during use by twelve different people. Dilution ratios at the Mask Scentometer’s five dilution-to-threshold (D/T) settings were found to be 0.35, 1, 2, 4.5 and 18. In Paper No.’s 2 and 4, ambient odor assessment methods were compared in both controlled laboratory conditions and in the field. Laboratory analysis of ambient air samples using dynamic triangular forced-choice olfactometry (DTFCO) did not correlate well with any of the ambient odor assessment methods. Average intensity-predicted D/T was roughly five times higher than D/T measured using a Nasal Ranger®, and D/T obtained using a Nasal Ranger® was roughly two to five times higher than corresponding D/T from a Mask Scentometer. In Paper 3, odor intensity ratings and Mask Scentometer readings were used to calibrate the AERMOD dispersion model for predicting odor concentrations downwind of area sources. Dispersion of odor from a swine waste treatment lagoon and two cattle feedlots was modeled with AERMOD and the predictions were compared to the observations using a statistical approach to develop scaling factors. These were found to be 12 for odor intensity and 0.15 for the Mask Scentometer (although a scaling factor between 0.5 and 0.7 is also justified). Random effects and autocorrelation were found to be significant in ambient odor assessment data. In Paper 4, the dispersion of odors from a swine production building complex was studied. CALPUFF and AERMOD were used to predict short-time-step (one minute) odor concentrations. Source emission measurements and meteorological data were collected to coincide with ambient odor measurements obtained using the Nasal Ranger®, Mask Scentometer, field odor intensity ratings, and DTFCO. In general, odor concentrations predicted using CALPUFF were found to be about twice those predicted by AERMOD. Model predictions agreed best with the readings from the Nasal Ranger® and Mask Scentometer; and both of these ambient odor assessment methods are suited for ground truthing AERMOD and CALPUFF, although some model scaling factor adjustment is needed. Adviser: Dennis D. Schult

    Trailer, labeling system, control system, and program for field implementation of computerized hole selection for layflat irrigation pipe

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    A system for installing and labeling lay flat irrigation pipe in flooded rice and furrow irrigated fields, and a trailer for laying a roll of pipe in an irrigated field. The trailer includes a flexible hitch assembly positioned at a first end of the trailer, wherein the hitch assembly couples the trailer to a vehicle. The trailer also includes a distribution assembly positioned at a second end of the trailer, wherein the distribution assembly includes a spindle and wherein the distribution assembly couples the roll of pipe to the trailer; and a gooseneck frame including a first end coupled to the hitch assembly and a second end coupled to the distribution assembly, with an upper member between the first end and the second end of the gooseneck, wherein the upper member of the gooseneck is elevated relative to the hitch assembly. The trailer may also include offset tandem wheels with a furrow assembly to facilitate the creation of a furrow ditch and for traversing flood irrigated levees for the purposes of installing lay-flat polyethylene pipe for irrigation. The trailer may also include an adjustable telescoping hitch to adjust to various vehicle hitch heights. The system includes a labeling system for indicating the punch size needed along the pipeline during installation. A computerized hole selection plan is developed and transferred to a microprocessor device, where sensors or a global positioning system is co-locate the device so the punch label can be applied along the pipe during installation

    Trailer, labeling system, control system, and program for field implementation of computerized hole selection for layflat irrigation pipe

    Get PDF
    A system for installing and labeling lay flat irrigation pipe in flooded rice and furrow irrigated fields, and a trailer for laying a roll of pipe in an irrigated field. The trailer includes a flexible hitch assembly positioned at a first end of the trailer, wherein the hitch assembly couples the trailer to a vehicle. The trailer also includes a distribution assembly positioned at a second end of the trailer, wherein the distribution assembly includes a spindle and wherein the distribution assembly couples the roll of pipe to the trailer; and a gooseneck frame including a first end coupled to the hitch assembly and a second end coupled to the distribution assembly, with an upper member between the first end and the second end of the gooseneck, wherein the upper member of the gooseneck is elevated relative to the hitch assembly. The trailer may also include offset tandem wheels with a furrow assembly to facilitate the creation of a furrow ditch and for traversing flood irrigated levees for the purposes of installing lay-flat polyethylene pipe for irrigation. The trailer may also include an adjustable telescoping hitch to adjust to various vehicle hitch heights. The system includes a labeling system for indicating the punch size needed along the pipeline during installation. A computerized hole selection plan is developed and transferred to a microprocessor device, where sensors or a global positioning system is co-locate the device so the punch label can be applied along the pipe during installation

    Irrigation system

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    A gravity irrigation system includes a distribution piping having apertures to distribute water to a field, and a valve located upstream of the distribution piping. The valve limits a pressure of the water being delivered to the distribution piping. The system also includes a sump to receive the water at a lowest elevation of the field, a depth sensor disposed within the sump, and a return pump disposed at least partially within the sump to move the water to an elevated portion of the field. The system also includes a motor to drive the return pump, and a power source coupled to a variable frequency drive that powers the motor and controls a motor speed proportionately to an indication of the depth sensor. The system also includes a transfer piping to bring the water from the return pump to a check valve and to the distribution piping

    The Assembly of Diversity in the Morphologies and Stellar Populations of High-Redshift Galaxies

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    We have studied the evolution in the morphologies, sizes, stellar-masses, colors, and internal color dispersion (ICD) of galaxies at z=1 and 2.3, using a near-IR, flux-limited catalog for the HDF-N. At z=1 most luminous galaxies have morphologies of early-to-mid Hubble-types, and many show transformations between their rest-frame UV-optical morphologies. Galaxies at z=2.3 have compact and irregular morphologies with no clearly evident Hubble-sequence candidates. The mean galaxy size grows from z=2.3 to 1 by 40%, and the density of galaxies larger than 3 kpc increases by 7 times. At z=1, the size-luminosity distribution is broadly consistent with that of local galaxies, with passive evolution. However, galaxies at z=2.3 are smaller than the large present-day galaxies, and must continue to grow in size and stellar mass. We have measured the galaxies' UV-optical ICD, which quantifies differences in morphology and the relative amount of on-going star-formation. The mean and scatter in galaxies' total colors and ICD increase from z=2.3 to 1. At z=1 many galaxies with large ICD are spirals, with a few irregular systems. Few z=2.3 galaxies have high ICD, and those that do are actively merging. We interpret this as evidence for the presence of older and more diverse stellar populations at z=1 that are not generally present at z>2. We conclude that the star-formation histories of galaxies at z>2 are dominated by discrete, recurrent bursts, which quickly homogenize the galaxies' stellar content, and are possibly associated with mergers. The increase in the stellar-population diversification by z<1.4 implies that merger-induced starbursts occur less frequently than at higher redshifts, and more quiescent star-forming modes dominate. This transition coincides with the emergence of Hubble-sequence galaxies. [Abridged]Comment: Accepted for publication in the Astrophysical Journal. 20 pages, in emulateapj forma

    Impact of Vegetative Treatment Systems on Multiple Measures of Antibiotic Resistance in Agricultural Wastewater

    Get PDF
    Wastewater is an important vector of antibiotic resistant bacteria and antibiotic resistance genes (ARB/G). While there is broad agreement that ARB/G from agricultural (ag) wastewaters can be transported through the environment and may contribute to untreatable infectious disease in humans and animals, there remain large knowledge gaps surrounding applied details on the types and amounts of ARB/G associated with different agricultural wastewater treatment options and different ag production systems. This study evaluates a vegetative treatment system (VTS) built to treat the wastewater from a beef cattle feedlot. Samples were collected for three years, and plated on multiple media types to enumerate tetracycline and cefotaxime-resistant bacteria. Enterobacteriaceae isolates (n = 822) were characterized for carriage of tetracycline resistance genes, and E. coli isolates (n = 673) were phenotyped to determine multi-drug resistance (MDR) profiles. Tetracycline resistance in feedlot runoff wastewater was 2-to-3 orders of magnitude higher compared to rainfall runoff from the VTS fields, indicating efficacy of the VTA for reducing ARB over time following wastewater application. Clear differences in MDR profiles were observed based on the specific media on which a sample was plated. This result highlights the importance of method, especially in the context of isolate-based surveillance and monitoring of ARB in agricultural wastewaters
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