2013-05-18T19:51:58Z http://etd.lib.montana.edu/etd/view/oai-feed.php?verb=ListRecords&metadataPrefix=oai_dc

http://etd.lib.montana.edu/etd/2013/farokhkish/FarokhkishB0513.pdf 2013-03-28T18:56:21Z

Effects of electrofishing removal on the channel catfish, Ictalurus punctatus, population in the San Juan River, New Mexico Farokhkish, Bahram The introduction of non-native species has been tied to the decline of native species in many areas around the world. The impacts of non-native introductions on native fisheries have prompted the establishment of non-native removal programs to suppress these populations of non-native species. The San Juan River Recovery and Implementation Program was established to mitigate the effects of the non-native channel catfish (Ictalurus punctatus (Rafinesque)) on native endangered fishes in the San Juan River. Although the recovery program has removed more than 136,000 channel catfish in the last ten years, a resurgence in endangered fishes has not been observed in the San Juan River. The recovery program personnel determined that population structure and maturation data were needed to establish what the current channel catfish population in the San Juan River looked like. This study evaluated the population structure and reproductive structure of the removed channel catfish population in the San Juan River 2011. The objectives of this study were to establish an age length key and to determine the age at maturation for channel catfish in the San Juan River. Channel catfish were collected between the months of June and August 2011 using raft mounted electrofishing gear. Length and weight were recorded for each fish removed, and samples of pectoral spines and gonads were collected to determine age and maturation. Data suggest that when compared with populations of channel catfish exhibiting normal growth the San Juan River channel catfish population is growing faster and is larger at a given age. However, data also suggest that only a small number of channel catfish are collected reproductively active, and all of these fish are > 400 mm total length (TL). Data also suggest that when compared with other channel catfish populations the San Juan River population is mature at a greater age. Based on these data the channel catfish population in the San Juan River may be compensating for removals and decreased densities by growing more quickly. These data indicate that the removal and recovery program should target large fecund adults to reduce recruitment and suppress the non-native population of channel catfish. 2013-05-15 Thesis Montana State University en http://etd.lib.montana.edu/etd/2013/farokhkish/FarokhkishB0513.pdf

http://etd.lib.montana.edu/etd/2013/havens/HavensN0513.pdf 2013-03-28T19:00:35Z

A high gain hybrid DC-DC boost-forward converter for solar panel applications Havens, Nicklas Jack As the demand for more efficient alternative energies increases, the demand to make the power electronics that go along with those energies increases as well. One of the major power components for photovoltaics is the DC-DC converter required to increase the voltage produced. A hybrid DC-DC boost-forward topology was explored. A switch on the secondary side can be turned off and the converter will take the characteristics of a boost converter. These predictions were confirmed by simulating this cirucit in MatLab Simulink, and finally by building a prototype circuit. A desired output of 170V - 100W was produced and the efficiency was measured. The boost-forward converter peaked at about 85% efficient which was below the 94% efficient boost converter. The boost-forward converter, however, was found to have a higher efficiency than the boost converter when the input voltage was below 34V . The circuit is designed to work as a boost converter when the input voltage is above 34V . When the input drops below that voltage the converter can be put into the boost-forward converter configuration by closing the switch on the secondary side. 2013-05-15 Thesis Montana State University en http://etd.lib.montana.edu/etd/2013/havens/HavensN0513.pdf

http://etd.lib.montana.edu/etd/2013/jessee/JesseeE0513.pdf 2013-03-28T19:03:48Z

Radiation ecologies: bombs, bodies, and environment during the atmospheric nuclear weapons testing period, 1942-1965 Jessee, Emory Jerry From 1945 to 1963 the United States Atomic Energy Commission detonated over 200 nuclear weapons tests at its Nevada and Pacific test sites, irradiating every living thing on the planet. Much of the historical scholarship on the period has focused on the scientific debate over the health effects of low-level radiation exposure or on determining what and when the Atomic Energy Commission knew about the health effects fallout. This dissertation, however, argues that the growth of ecological thinking about the health effects of fallout exposure in environmental sciences such as ecology, oceanography, and meteorology dramatically reshaped what was known about radiological risk and provided the scientific foundation for the Limited Test Ban Treaty. By highlighting the ways that radiation traveled beyond the boundaries of the test sites and became incorporated into critical human food chains, this ecological way of perceiving fallout largely replaced previous approaches to fallout risks derived from the discipline of health physics that focused on external forms of radiation exposure and ideas of spatial containment. This dissertation, however, also argues that fallout radiation proved much more than a menacing pollutant. Because environmental scientists can utilize radiation as a tool to trace out structure and function of the ecosystem, as well as oceanic and atmospheric motions, it also emerged during this period as a critical scientific practice. In tracing radiation as it moved through the environment, environmental scientists not only made legible the connections between the health of human bodies and the irradiated environment, but also demonstrated empirically that the earth was a spatially integrated biosphere. Such realizations, this dissertation concludes, formed an important footing the nascent environmental movement and helped establish the authority of the environmental sciences in matters of environmental pollution and regulation. 2013-05-15 Dissertation Montana State University en http://etd.lib.montana.edu/etd/2013/jessee/JesseeE0513.pdf

http://etd.lib.montana.edu/etd/2013/lucon/LuconJ0513.pdf 2013-03-28T19:08:00Z

Development of protein nanoparticle based composite materials Lucon, Janice Elizabeth Inspired by the core-shell composite structures found in nature, a range of protein based composites have been developed. These materials were made using synthetic approaches, which utilized the native protein architecture as an initiation point and size constrained reaction vessel for the piecewise formation of the second material. In the first illustration of this approach, a protein-P t composite was formed, where the protein cage has been modified to include a metal binding moiety for improved synthesis of metallic P t nanoclusters, which were shown to be an active H ₂ catalyst. This composite was analyzed by native mass spectrometry to determine the number of P t ions bound prior to mineralization and to measure the distribution of species after mineralization, which provided a unique view into the mineralization process. The second illustration was a material synthesized using the cage-like protein architecture as an internal guiding synthetic scaffold for the formation of a coordination polymer core inside the protein cage. The construction of this coordination polymer was unusual in that unlike normal coordination polymer synthesis, coordination of the metal preceded formation the ditopic ligands, which were afterwards completed using azide-alkyne click chemistry. Finally, a collection of protein-polymer composites were developed, which utilized a living radical polymerization method, atom transfer radical polymerization, to form internal polymer cores. By labeling one of these protein-polymer constructs with a Gd based MRI contrast agent a material with vastly improved relaxivity was made. The development of each of these three types of composites served to improve our understanding of the natural systems, from which they are derived, and provide a basis for further development of advanced multicomponent nanomaterials. 'Co-authored by Md Joynal Abedin, Masaki Uchida, Lars Liepold, Craig C. Jolley, Mark Young, Trevor Douglas, Shefah Qazi, Gregory J. Bedwell, Ben LaFrance, and Peter E. Prevelige, Jr.' 2013-05-15 Dissertation Montana State University en http://etd.lib.montana.edu/etd/2013/lucon/LuconJ0513.pdf

http://etd.lib.montana.edu/etd/2013/mayfield/MayfieldM0513.pdf 2013-03-28T19:14:05Z

Limiting factors for trout populations in the upper Clark Fork River superfund site, Montana Mayfield, Mariah Pine Large-scale heavy metal contamination of the upper Clark Fork River from mining deposits has created significant damage to aquatic habitat in the drainage. Trout are present in the system, although with abundances lower than expected. The objectives of this study were to identify critical habitat areas and to identify conditions that continue to limit both native and nonnative trout populations, with the focus of the study on the lingering environmental effects caused by high heavy metal concentrations. A radiotelemetry study, with 256 tagged brown trout Salmo trutta, westslope cutthroat trout Oncorhynchus clarkii lewisi, and cutthroat/rainbow hybrid trout, was conducted from 2009 to 2011. The radiotelemetry relocation data was used to determine temporal and spatial patterns in movement and survival rates in relation to heavy metals and other environmental factors, and to identify critical habitat areas (e.g., spawning locations and overwintering areas). Brown trout spawning occurred in numerous tributaries throughout the basin and in the upper reaches of the mainstem. Cutthroat trout spawned only in tributaries, and these tributaries were often smaller and more degraded by land use practices than brown trout spawning tributaries. Multistate mark-recapture survival analysis estimated that survival is lowest in the stream segment with the greatest amount of heavy metal contamination; the weekly likelihood of survival was estimated at 0.97 (95% confidence interval 0.97 - 0.98) for brown trout and 0.90 (95% confidence interval 0.84 - 0.97) for cutthroat trout. Additionally, weekly survival estimates for cutthroat trout in tributaries was also low (0.92; 95% confidence interval 0.87 - 0.94), likely because of anthropogenic land use pressures. Very limited movement was observed, except in relation to spawning migrations. Cutthroat trout moved greater distances and at a higher rate than brown trout. The results from this study indicate that the remaining mining contamination continues to reduce trout survival rates throughout the basin and should be removed in order to increase trout densities. Additionally, restoration priority should be placed on tributaries that are negatively affected by land use pressures. 2013-05-15 Thesis Montana State University en http://etd.lib.montana.edu/etd/2013/mayfield/MayfieldM0513.pdf

http://etd.lib.montana.edu/etd/2013/naughton/NaughtonJ0513.pdf 2013-03-28T19:18:31Z

Salmonid response to superfund remediation in Silver Bow Creek, Montana Naughton, Joseph Patrick Uncontrolled disposal of hard rock mining wastes in the Butte hill mining district of Montana, led to the extirpation of fish from Silver Bow Creek throughout the 20th century. Superfund remediation has been ongoing since 1998 and metal concentrations are reduced. However, water quality remains poor due to inadequate treatment of municipal sewage. To assess the effectiveness of Superfund remediation in reestablishing salmonid populations, we evaluated seasonal salmonid abundance and movement in the Silver Bow Creek watershed over a 3-year period. Spatially-continuous abundance surveys were conducted in 34 main stem stream km and each sampled westslope cutthroat trout Oncorhynchus clarkii lewisi (n = 787) and brook trout Salvelinus fontinalis (n = 1,846) was PIT-tagged. Movements of PIT-tagged individuals were monitored at seven stationary antenna sites and during six seasonal portable antenna surveys. Monthly synoptic water quality samples were collected. In the main stem, water quality was poor below the wastewater effluent and was characterized by acutely toxic copper concentrations, elevated ammonia levels (e.g., NH ₃-N = 2.8 mg/L), and hypoxia during summer nights (e.g., DO = 1.4 mg/L). Longitudinal abundance of salmonids closely resembled the longitudinal trend in DO. Regression analysis revealed strong associations between salmonid occurrence and abundance with DO (positive) and copper (negative) concentrations during the summer. However, westslope cutthroat trout relative abundance increased between summer and winter in remediated segments that had been hypoxic during the summer. Few brook trout recolonized the remediated main stem during the study period and the wastewater effluent may have deterred brook trout movement. Westslope cutthroat trout moved into remediated segments during the late summer and early fall as hypoxia subsided. The majority of westslope cutthroat trout sampled in the main stem were large-bodied adults (≥200 mm TL) contrasting with the predominantly small-bodied counterparts in the tributaries. Despite hypoxia and copper toxicity, recolonization of indigenous westslope cutthroat trout apparently was driven by the reexpression of a fluvial-adfluvial migratory behavior, a pattern that was not possible during the 100-150 years of main stem contamination. 2013-05-15 Thesis Montana State University en http://etd.lib.montana.edu/etd/2013/naughton/NaughtonJ0513.pdf

http://etd.lib.montana.edu/etd/2013/perz/PerzK0513.pdf 2013-03-28T19:27:05Z

Effect of growth path on carcass composition and meat quality Perz, Katharine Anna Reducing variation in tenderness is a goal for the meat industry. The objective of this study was to determine if different growth patterns, not caused by nutrient restriction, impacted carcass characteristics and tenderness. Simmental × Angus steers (n = 18) reared under similar conditions, fed in the same pen at the feedlot, were allocated into fast (n = 9) and slow (n = 9) growing groups based upon four sets of weight data. After slaughter, carcass data were obtained. The striploin was removed, cut into steaks, and aged for 1, 3, 7, 14, and 21 days. For each aging period, one steak per steer underwent evaluation of shear force and MFI. Myofibrils were isolated from aged muscle samples and protein degradation was visualized with the use of SDS-PAGE. Carcass weight (P< 0.0001) and LD area (P = 0.0093) were significantly affected by growth rate. Shear force (P = 0.0003) and MFI (P< 0.0001) were significantly affected by length of aging, but not by growth rate (P≥ 0.3184); nor was there a significant interaction between growth rate and length of aging (P≥ 0.6555). Even though the shear force × growth rate finding was not statistically significant, shear force of steaks from fast-growing animals had a greater reduction in shear force values indicating a difference in early tenderization. A currently unidentified protein with a molecular weight between 130 and 100kDa was seen earlier postmortem in more tender muscle. This degradation was more apparent in muscle from fast growing steers. A 30kDa component also appeared earlier, and at a greater band intensity, in more tender muscle. Degradation of the 30kDa component was also more evident in fast growing steers. These results suggest that there is a difference in protein degradation in muscle from animals with differing growth paths. The results of this study suggest that more research is warranted to identify differences in protein degradation due to growth rate and to elucidate the effect of growth rate on variation in tenderness. 2013-05-15 Thesis Montana State University en http://etd.lib.montana.edu/etd/2013/perz/PerzK0513.pdf

http://etd.lib.montana.edu/etd/2013/rains/RainsF0513.pdf 2013-03-28T19:33:21Z

Biological and physical controls of CO ₂ flux through snow in a forested ecosystem Rains, Fredrick Aaron Soil CO ₂ efflux is the dominant component of carbon loss in many temperate forests. Wintertime respiration accounts for a significant contribution of the annual carbon loss to the atmosphere from terrestrial ecosystems, but the magnitude of this flux and physical transport mechanisms through snow are unclear. This research examines wintertime CO ₂ flux in a lodgepole pine forest in the Upper Stringer Creek catchment at the Tenderfoot Creek Experimental Forest, Montana, USA. I hypothesized that: CO ₂ production and efflux during the winter contributes a significant amount (10-20%)of CO ₂ efflux to the atmosphere in the Tenderfoot Creek Experimental Forest; 2) Snow properties, i.e. depth and density, and thereby porosity and tortuosity vary during the winter via snow metamorphosis, thus changing the impediment to flux through the snow medium and CO ₂ production increases when the snowpack becomes isothermal during melt due to increased soil moisture and soil temperature. A micrometeorological stations was installed to measure soil water content, soil temperature, incoming and outgoing radiation, albedo, snow depth, snow/soil interface CO ₂ concentration, atmospheric CO ₂ concentration, three-dimensional wind speed, and above snow/sub-canopy CO ₂ flux on a half-hourly basis. In addition, throughout the winters of 2010/2011 and 2011/2012 snow pit analyses was performed in triplicate approximately once monthly and snow depth, density, and temperature were measured in 10-centimeter increments. Three methodological approaches were used to analyze CO ₂ flux through the snow pack: Chamber on snow, two-point Fick's law based diffusivity modeling, and snow-surface/subcanopy eddy covariance. The results of the comparison show a significant difference in measured and estimated flux between methodologies during early and late winter, while demonstrating the Fick's based model is can accurately estimate up 75% of measured flux during mid-winter. Observations are consistent with advection, in addition to diffusion, as a mechanism of CO ₂ transport through snow such that observation strategies that do not account for advection may underestimate wintertime efflux. Furthermore, all three methodologies indicate that wintertime respiration is a major contributor to the annual carbon budget when mean flux rates are compared to growing season flux rates. 2013-05-15 Thesis Montana State University en http://etd.lib.montana.edu/etd/2013/rains/RainsF0513.pdf

http://etd.lib.montana.edu/etd/2013/vogt/VogtS0513.pdf 2013-03-28T19:37:51Z

Nuclear magnetic resonance studies of biological and biogeochemical processes Vogt, Sarah Jane The research presented uses nuclear magnetic resonance (NMR) experimental techniques to study systems of geochemical and biological processes. This thesis first presents an introduction to the NMR experimental concepts and data analysis. Several experimental systems are then described in detail: biological reduction of uranium; biofilm growth in porous media; and solutions and gels of alginate, a polymer molecule commonly found in the biofilm polymeric matrix. Bioremediation of heavy metal contaminants such as uranium around nuclear waste storage sites is an important environmental problem. Uranyl (UO ₂ ²+) is soluble in water, while uraninite (UO ₂) precipitates as nanoparticles. Certain types of bacteria are able to use uranium as the electron acceptor and reduce uranyl ions to uraninite. The experiments presented used a solution of uranyl ions that was reduced by a sulfur reducing bacteria and were studied using images and relaxation measurements. The growth of biofilms in the subsurface may also be used for bioremediation. Biofilms form when bacteria attach to surfaces and then produce and live within a polymeric matrix known as the extracellular polymeric substance (EPS). Experiments were done on a biofilm grown through the pore structure of a model bead pack. During the biofilm growth, displacement-relaxation correlation experiments were performed which were able to separate the biofilm phase from the bulk fluid phase using relaxation information. The results presented show that during biofilm growth very little convective flow occurs through the biofilm phase, while pore clogging causes channeling that increases the flow through non-biofilm filled pores and increases hydrodynamic dispersion. The EPS matrix of a biofilm contains DNA, proteins, and biologically produced polymers. Some biofilms such as those produced by the bacteria Pseudomonas aeruginosa contain the polymer alginate. Three biologically produced alginates were compared: alginate produced by algae, alginate produced by P. aeruginosa FRD1153, and alginate produced by P. aeruginosa FRD1. A diffusive reaction gelation process was used to produce heterogeneous gels which were analyzed both during and after gelation. Homogeneous gels and solutions were studied using relaxation dispersion techniques. Differences in hydrogen exchange processes, polymer conformation, and gel structure were analyzed. 'Co-authored by Brandy D. Stewart, Joseph D. Seymour, Brent M. Peyton, and Sarah L. Codd, Alexis B. Sanderlin, Hilary T. Fabich, Matthew L. Sherick, Jennifer R. Brown, Michael J. Franklin.' 2013-05-15 Dissertation Montana State University en http://etd.lib.montana.edu/etd/2013/vogt/VogtS0513.pdf

http://etd.lib.montana.edu/etd/2013/wooldridge/WooldridgeR0513.pdf 2013-03-28T19:46:10Z

The effects of explosives on the physical properties of snow Wooldridge, Robyn Elaine Explosives are a critically important component of avalanche control programs. They are used to both initiate avalanches and to test snowpack instability by ski areas, highway departments and other avalanche programs around the world. Current understanding of the effects of explosives on snow is mainly limited to shock wave behavior demonstrated through stress wave velocities, pressures and attenuation. This study seeks to enhance current knowledge of how explosives physically alter snow by providing data from field-based observations and analyses that quantify the effect of explosives on snow density, snow hardness and snow stability test results. Density, hardness and stability test results were evaluated both before and after the application of 0.9 kg cast pentolite boosters as surface and air blasts. Changes in these properties were evaluated at specified distances up to 5.5 meters (m) from the blast center for surface blasts and up to 4 m from the blast center for air blasts. A density gauge, hand hardness, a ram penetrometer, Compression Tests (CTs), and Extended Column Tests (ECTs) were used. In addition to the field based observations, the measurement error of the density gauge was established in laboratory tests. Results from surface blasts did not provide conclusive data. Air blasts yielded statistically significant density increases out to a distance of 1.5 m from the blast center and down to a depth of 50 centimeters (cm). Statistically significant density increases were also observed at the surface (down to 20 cm) out to a distance of 4 m. Hardness data showed little to no measurable change. Results from CTs showed a statistically significant decrease in the number of taps needed for column failure 4 m from the blast center in the post-explosive tests. A smaller data set of ECT results showed no overall change in ECT score. The findings of this study provide a better understanding of the physical changes in snow following explosives, which may lead to more effective and efficient avalanche risk mitigation. 2013-05-15 Thesis Montana State University en http://etd.lib.montana.edu/etd/2013/wooldridge/WooldridgeR0513.pdf