75 research outputs found
RSRM-3 (360L003) Ballistics/Mass Properties Report
The propulsion performance and reconstructed mass properties data from Morton Thiokol's RSRM-3 motors which were assigned to the STS-29 launch are presented. The composite type solid propellant burn rates were close to predicted. The performance of the pair of motors were compared to some CEI Specifications. The performance from each motor as well as matched pair performance values were well within the CEI specification requirements. The nominal thrust time curve and impulse gate information is included. Post flight reconstructed Redesigned Solid Rocket Motor (RSRM) mass properties are within expected values for the lightweight configuration
Oligocene and Miocene continental sedimentation, tectonics, and S-type magmatism in the southeastern Andes of Peru (Crucero basin) : geodynamic implications
Dans le bassin de Crucero, la formation Cayconi est constituée par des dépôts d'origine continentale; des roches volcaniques basiques et acides y sont intercalées. A partir des données de terrain et des analyses isotopiques, les auteurs montrent que les sédiments et les produits volcaniques sont d'âge OLigocène-Miocène. Les données sédimentologiques, structurales et pétrologiques permettent d'illustrer l'évolution géodynamique du bassin et d'avancer des hypothèses concernant l'association, au niveau de la formation Cayconi, de laves acides et basique
Simulated filtration pond to remove Escherichia coli from irrigation water.
The United States Food and Drug Administration?s (FDA) proposed water rules to implement the Food Safety Modernization Act (FSMA) could leave some growers, especially those who rely on an irrigation system based on recycled water, unable to irrigate fresh produce with their irrigation water, especially those who rely on an irrigation system based on recycled water. Irrigation water could be treated with chlorine, ozone, or other product to reduce the bacterial load in the water; however, at present not one of these options has been approved by the Environmental Protection Agency for treating irrigation water. In an attempt to reduce the number of bacteria present in irrigation water entering a farm, a simulated filter pond was constructed using gravel, sand, and silt-loam soil. The filter pond sought to utilize in part what occurs naturally with the filtration of water through the soil profile. This natural process provides clean water in wells and aquifers. The simulated pond reduced the Escherichia coli load in water by 95% with a flow rate of 3.9 gal/h/yd2. In order to increase the water productivity of the simulated filter pond, most of the dirt was removed; subsequently the E. coli filtration rate went to 55% and 46%, with flow rates of 12.9 gal/h/yd2 and 17.6 gal/h/yd2, respectively
Movement of Escherichia coli in soil as applied in irrigation water.
The US Food and Drug Administration (FDA) has proposed that If irrigation water exceeds 235 colony-forming units (CFU) of E. coli /100 ml in any one sample or 126 CFU/100 ml in the average of any five consecutive samples, growers would have to cease using that water in any way that directly contacts the surface of fresh produce (FDA 2013). The FDA has proposed that these E. coli levels are an indication of high risk of bacterial contamination of fresh onion (Allium cepa L.) bulbs regardless of the irrigation system. If onion irrigation exceeds 235 CFU, it is not known whether the contaminated water applied by furrow or drip irrigation actually reaches the onion bulb. Soil could filter E. coli and other bacteria before irrigation water reaches onion bulbs. ?Vaquero? onions were grown on Owyhee silt loam. In our preliminary studies reported here, well water free of E. coli was applied to onions through drip irrigation or through furrow irrigation. A second water source was intentionally enriched with E. coli by being run across a pasture and recaptured prior to use. Furrow and drip irrigation were used to apply this water containing 218 to >2400 MPN/100ml for 11+ hours per irrigation. E. coli was monitored in the soil water at the end of irrigation cycles through direct sampling of the soil. Soil water was also sampled using sterile soil solution capsules (SSSC) to sample E. coli in the soil water that moved into place, to differentiate the movement of soil water from the soil water already in place. Soil water measurements were made adjacent to the water source, half way to the bulbs, and immediately adjacent to the onion bulbs. For furrow irrigation with ditch water the E. coli counts in the soil next to the onion bulbs was only 0% and 21% of the counts in the irrigation water following the first and second irrigations, respectively. During subsequent furrow irrigations, the E. coli counts in the soil water next to the onion bulbs exceeded the counts in the irrigation water. For drip irrigation with ditch water, the E. coli counts in the soil solution next to the onion bulbs remained very low. The soil water sampled by the SSSC adjacent to the onion bulbs drip-irrigated with ditch water also had very low E. coli counts
Survival of Escherichia coli on onion during field curing and packout.
The Food and Drug administration has expressed concern that Onions (Allium cepa) irrigated with water contaminated with high rates of Escherichia coli could harbor E. coli on their surface or interior. On the other hand, since onions contain antimicrobial compounds and field conditions may not be conducive to E. coli survival, the E. coli population on the surface of onions might become negligible through the course of field curing. Further, the relationship between the E. coli in the irrigation water to the E. coli on onion bulbs after field curing, harvest, and packout has not been studied. To determine if E. coli should be of concern in onion production, we sought to measure the die-off of E. coli on onions between the last irrigation and harvest and the presence of E. coli on onions after packout. Well water was tested and had no E. coli; ditch water intentionally run across a pasture prior to use had 218 to > 2400 MPN of E. coli/100ml. Onions were sampled from those furrow irrigated (ditch water) and those drip irrigated (well water) starting at lifting 3 September 2013 for four consecutive weeks. At 0 and 28 days after lifting, both interior and exterior of the onions were tested for E. coli. At 7, 14, and 21 days after lifting, only the exterior of the onions was tested. None of the onions contained E. coli internally at 0 or 28 days after lifting. At lifting E. coli was present on the exterior of both the drip and furrow irrigated onions and seemed to be largely unrelated to the irrigation water. The exterior E. coli contamination decreased rapidly after lifting. After harvest and packout on 14 October 2013, no E. coli was detected on the onion bulb exteriors from either irrigation treatment. E. coli introduced into the onion field through furrow irrigation was not present on or in the packed out onion bulbs
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