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Item Escherichia coli O157:H7 attachment and persistence within root biofilm of common treatment wetlands plants(2017-01) VanKempen-Fryling, Rachel J.; Camper, Anne K.Pathogen retention and subsequent release within the rhizosphere of wastewater treatment wetlands may be a concern for human health. To address this concern, the enteric pathogen Escherichia coli O157:H7 with a DsRed plasmid insertion was used as a model pathogenic organism in an open-air chemostat reactor with constant flow of simulated wastewater. Colonization and persistence of the organism was tracked on roots of two obligate wetland plant species, Carex utriculata and Schoenoplectus acutus, originally grown in pilot scale wetland reactors. Teflon nylon string, clean and with existing indigenous biofilm, was used as an inert surface control. Epifluorescence microscopy and qPCR were used to verify E. coli O157:H7 abundance for up to 1 week. Initial attachment was seen on all surfaces, with colonization decreasing through 1 week. qPCR showed preferential association of the pathogen with roots over the nylon. There was a significant difference between plant type; S. acutus showed significantly higher numbers compared to C. utriculata. E. coli O157:H7 binding and persistence on root surfaces may be a means of survival in treatment wetlands.Item Nitrification and potential control mechanisms in simulated premises plumbing(2011-11) Rahman, Mohammad S.; Encarnacion, G.; Camper, Anne K.Indigenous drinking water organisms were used to establish nitrification in glass reactors containing copper or polyvinyl chloride (PVC) surfaces. The reactors were fed soil-derived humics as the organic carbon source and ammonium sulfate as the nitrogen source in biologically treated tap water. Water in the reactors was stagnant for 8 h and then flowed for 5 min to simulate conditions in household plumbing. Following the establishment of complete nitrification (conversion of ammonia to nitrate) in both reactor types, various inhibitors of nitrification were tested followed by a period where recovery of nitrification was observed. In one PVC reactor, copper was gradually introduced up to 1.3 ppm. To ensure that most of the copper was in the ionic form, the pH of the influent was then gradually lowered to 6.6. No significant change in nitrification was observed in the presence of copper. Chlorite was introduced into copper and PVC reactors at doses increasing from 0.2 ppm to 20 ppm. There was limited effect on the PVC system and inhibition in the copper reactor only at 20 ppm. Chloramine was tested at chlorine to ammonia ratios ranging from 0.5:1 to 5:1. Nitrification activity was impacted significantly at a 5:1 ratio and ultimately stopped, with the fastest response being in the copper system. Whenever a control mechanism was tested, there was increased release of copper from the reactors with copper coupons. In all cases, nitrification recovered when inhibitors were removed but the rates of recovery differed depending on the treatment method and coupon surface.Item Reducing the risk of well bore leakage using engineered biomineralization barriers(2011-04) Cunningham, Alfred B.; Gerlach, Robin; Spangler, Lee H.; Mitchell, Andrew C.; Park, Saehan; Phillips, Adrienne J.If CO2 is injected in deep geological formations it is important that the receiving formation hassufficient porosity and permeability for storage and transmission and be overlain by a suitable low-permeability cap rock formation. When the resulting CO2 plume encounters a well bore, leakage may occur through various pathways in the “disturbed zone†surrounding the well casing. Gasda et al.[9], propose a method for determining effective well bore permeability from a field pressure test. If permeability results from such tests prove unacceptably large, strategies for in situ mitigation of potential leakage pathways become important. To be effective, leakage mitigation methods must block leakage pathways on timescales longer than the plume will be mobile, be able to be delivered without causing well screen plugging, and be resistant to supercritical CO2 (ScCO2) challenges. Traditional mitigation uses cement, a viscous fluid that requires a large enough aperture for delivery and that also must bond to the surrounding surfaces in order to be effective. Technologies that can be delivered via low viscosity fluids and that can effectively plug small aperture pathways, or even the porous rock surrounding the well could have significant advantages for some leakage scenarios.We propose a microbially mediated method for plugging preferential leakage pathways and/or porous media, thereby lowering the risk of unwanted upward migration of CO2, similar to thatdiscussed by Mitchell et al.[12].We examine the concept of using engineered microbial biofilms which are capable of precipitating crystalline calcium carbonate using the process of ureolysis. The resulting combination of biofilm plus mineral deposits, if targeted near points of CO2 injection, may result in the long-term sealing of preferential leakage pathways. Successful development of these biologically-based concepts could result in a CO2 leakage mitigation technology which can be applied either before CO2 injection or as a remedial measure. Results from laboratory column studies are presented which illustrate how biomineralization deposits can be developed along packed sand columns at length scales of 2.54 cm and 61 cm. Strategies for controlling mineral deposition of uniform thickness along the axis of flow are also discussed.Item A modified CDC biofilm reactor to produce mature biofilms on the surface of PEEK membranes for an in vivo animal model application(2011-03) Williams, Dustin L.; Woodbury, Kassie L.; Haymond, B. S.; Parker, Albert E.; Bloebaum, R. D.Biofilm-related infections have become a major clinical concern. Typically, animal models that involve inoculation with planktonic bacteria have been used to create positive infection signals and examine antimicrobial strategies for eradicating or preventing biofilm-related infection. However, it is estimated that 99.9%of bacteria in nature dwell in established biofilms. As such, openwounds have significant potential to become contaminatedwith bacteria that reside in a well-established biofilm. In this study, a modified CDC biofilm reactor was developed to repeatably grow mature biofilms of Staphylococcus aureus on the surface of polyetheretherketone (PEEK) membranes for inoculation in a future animal model of orthopaedic implant biofilm-related infection. Results indicated that uniform, mature biofilms repeatably grew on the surface of the PEEK membranes.Item Role of electronic measurement systems in new product development(Montana State University - Bozeman, College of Engineering, 2002) Ayare, Adwait PrabhakarItem The formulation of a technique for finding an optimal 'skidding' road layout(Montana State University - Bozeman, College of Engineering, 1968) Carter, Michael RichardItem A verification study of the psychophysical method for upper extremity work(Montana State University - Bozeman, College of Engineering, 1994) Willis, Michael L.Item An investigation of the effect of ergogenic corsets on biomechanical, physiological and psychophysical parameters during manual lifting(Montana State University - Bozeman, College of Engineering, 1993) Duggasani, Amarnath R.Item The selection of optimal break points in piecewise linear function analysis(Montana State University - Bozeman, College of Engineering, 1973) Lai, Haifie LooItem Expert system technology for integration(Montana State University - Bozeman, College of Engineering, 1988) Groeneveld, Bennett John