I studied the characteristics of fence mortality in pronghorn (Antilocapra americana), mule deer (Odocoileus hemionus), and elk (Cervus elaphus) along roads in Colorado and Utah from June 2004 to June 2005. I defined a direct-fence mortality as a carcass caught directly in a fence and an indirect-fence mortality as a carcass on the ground within 10 m of a fence. I estimated an average annual direct mortality occurrence of 0.25 mortalities/km (0.078 mule deer mortalities/km, 0.113 pronghorn mortalities/km, and 0.061 elk mortalities/km). The highest fence-mortality rates for ungulates occurred during August, which coincided with weaning of fawns on my study area. Mule deer and pronghorn both jumped fences in >81% of observed crossings and did not differ in their crossing methods (P = 0.37). Getting caught between the top 2 wires was the leading cause of death for fence mortalities. Mule deer suffered higher fence-mortality rates than elk or pronghorn because they crossed fences more frequently and fed in the right-of-way of the road more often (P < 0.001). Juveniles were 8 times more likely to die in fences than adults. Woven-wire fence types were more lethal to ungulates (especially juveniles) than other fence types (P < 0.001). Woven wire with a single strand of barbed wire above it was significantly more lethal to ungulates than woven wire with 2 strands of barbed wire above it, or 4-strand barbed-wire fence (P < 0.001). There was a direct relationship between the frequency of fence-mortalities and ungulate abundance (P < 0.001 ). Traffic volumes had an inverse relationship with fence mortality frequencies (P < 0.001) and ungulate densities along the right-of-way (P < 0.001). Indirect mortality (i.e., carcasses within 10 m of fences) composed 66% of fence-related mortality, whereas direct-fence mortality (i.e., carcasses in fences) composed a mere 33%. Additionally, indirect-fence mortality was found to be greater along woven-wire fences, when compared to barbed-wire fence types (P = 0.003).

In 1959, Union Pacific Railroad constructed a rock-filled causeway bisecting Utah’s Great Salt Lake, separating the lake into a north and south arm. Flow between the two arms was limited to two 4.6 meter wide culverts installed during original construction, an 88 meter breach opening installed in 1984, and the semi porous boulder and gravel causeway material. The south arm receives nearly all streamflows entering Great Salt Lake and a salinity gradient between the two arms developed over time. North arm salinity is often at or near saturation, averaging 317 g\L since 1966, while the south is considerably less saline, averaging 142 g\L since 1966. Ecological and industrial uses of the lake depend on salinity levels staying within physiologic and economic thresholds. Union Pacific Railroad proposed to replace aging culverts with a bridge, and provided four alternative bridge designs. Northern Utah’s variable climate complicates management of the causeway, where lake elevation and salinity are affected by wet and dry periods. Understanding the historical duration, magnitude, and frequency of wet and dry periods can inform future management decisions. I model the effect of each proposed bridge design on Great Salt Lake salinity and elevation in both arms by updating and applying US Geological Survey’s Great Salt Lake Fortran Model. I used measured historical streamflow and a 400-year tree-ring paleo-streamflow reconstruction to understand lake elevation and salinity sensitivity to longer-term climate variability. The model accurately simulates historical lake elevation and salinity and is sensitive to proposed bridge designs. Bridge alternatives vary salinity by 20 g\L within each arm using historical 1966-2012 conditions. When the model was run with the 400-year paleo-reconstructed hydrology, I find that the 20th century had the lowest average lake level of any century since 1600, and that 20th century floods were smaller than in previous centuries, both in terms of length and magnitude. With the 400-year paleo-streamflow model, differences of south arm salinity between bridge alternatives increase considerably through time, where alternative D results in salinity up to 100 g/l less than alternative A and that the current condition of the causeway would result in a fundamental change in Great Salt Lake characteristics, with the south arm approaching freshwater conditions at times. This research demonstrates that mass balance models are useful to predict management effects on terminal lake ecosystems, and provides a unique approach to reconstruct terminal lake paleo-salinity.

Gettering of impurities with oxygen precipitates is widely used during the fabrication of semiconductors to improve the performance and yield of the devices. Since the effectiveness of the gettering process is largely dependent on the initial interstitial oxygen concentration, accurate measurements of this parameter are of considerable importance. Measurements of interstitial oxygen following thermal cycles are required for development of semiconductor fabrication processes and for research into the mechanisms of oxygen precipitate nucleation and growth. Efforts by industrial associations have led to the development of standard procedures for the measurement of interstitial oxygen in wafers. However practical oxygen measurements often do not satisfy the requirements of such standard procedures. An additional difficulty arises when the silicon wafer has a low resitivity (high dopant concentration). In such cases the infrared light used for the measurement is severely attenuated by the electrons of holes introduced by the dopant. Since such wafers are the substrates used for the production of widely used epitaxial wafers, this measurement problem is economically important. Alternative methods such as Secondary Ion Mass Spectroscopy or Gas Fusion Analysis have been developed to measure oxygen in these cases. However, neither of these methods is capable of distinguishing interstitial oxygen from precipitated oxygen as required for precipitation studies. In addition to the commercial interest in heavily doped silicon substrates, they are also of interest for research into the role of point defects in nucleation and precipitation processes. Despite considerable research effort, there is still disagreement concerning the type of point defect and its role in semiconductor processes. Studies of changes in the interstitial oxygen concentration of heavily doped and lightly doped silicon wafers could help clarify the role of point defects in oxygen nucleation and precipitation processes. This could lead to more effective control and use of oxygen precipitation for gettering. One of the principal purposes of this thesis is the extension of the infrared interstitial oxygen measurement technique to situations outside the measurement capacities of the standard technique. These situations include silicon slices exhibiting interfering precipitate absorption bands and heavily doped n-type silicon wafers. A new method is presented for correcting for the effect of multiple reflections in silicon wafers with optically rough surfaces. The technique for the measurement of interstitial oxygen in heavily doped n-type wafers is then used to perform a comparative study of oxygen precipitation in heavily antimony doped (.035 ohm-cm) silicon and lightly doped p-type silicon. A model is presented to quantitatively explain the observed suppression of defect formation in heavily doped n-type wafers.

Louisiana’s wetlands are losing land in response to sea level changes, anthropogenic influences and natural marine processes. Historical satellite image analysis reveals that between 2005 and 2015, fifteen tidal creeks in Barataria Bay, Louisiana eroded at the rate of 1.80 m/yr (± 1.98 m), and the open water area behind these creeks enlarged at the rate of 530.00 m2/yr (± 204.80 m2). This research revealed that selected tidal creeks within the estuary have cross-sectional areas larger (2639% larger) than established ocean-inlet equilibrium models would predict. This work suggests that tidal prism to tidal creek cross-sectional area relationships in Barataria Bay are most strongly shaped by creek exposure to waves and secondarily by tide range and currents. A trend of increased inlet erosion rates due to large fetch distances is evident, but impacts from storm driven subtidal variations also play an important role.

This research investigated patterns in elevation change in newly built wetlands in the Atchafalaya delta, and newly restored wetlands in the Sacramento-San Joaquin River delta. RSETs were used to measure small changes in elevation, and soil cores were processed to examine mineral and organic contributions. Elevation change was highly variable, responding to influences from water level, river discharge, storms and vegetation. Mineral matter consistently added more to the marsh soil through volumetric and gravimetric contributions. Organic contributions were not significantly different across sites, suggesting the type of emergent vegetation at a site may not be the most important factor. Sites with the lowest elevations had the highest rates of positive elevation change. Higher elevation sites were more exposed and had negative rates of elevation change. The findings suggest ideal sites for marsh building are in areas that receive sediment input, are protected from high-energy events, and can support emergent vegetation.

Conservation and restoration of quaking aspen in the western United States requires an understanding of how and when aspen clones became established, how clones adapt to environmental challenges, and how individual clones interact within stands. I used molecular tools to identify individual clones in a natural population of aspen in southern Utah and detected high and low levels of clonal diversity within stands. Stands with high clonal diversity were located in areas with a more frequent fire history, indicating that fires may have prepared sites for seed germination and establishment over time. Conversely, areas of low clonal diversity corresponded to areas with less frequent fire. The same molecular tools were then used to investigate clonal interactions/succession over relatively recent time. For this portion of the study I sampled small, medium, and large aspen ramets (stems) at 25 subplots within spatially separated one-hectare plots, and mapped the clonal identities. I found that approximately 25% of the clones appeared to be spreading into adjacent clones, while 75% of the clones had a stationary pattern. In the final portion of the study, I again used molecular tools to identify aspen clones and investigated tradeoffs between growth and defense chemistry in mature, naturally-occurring trees. Growth was estimated using a ten-year basal area increment, and the percent dry weight of salicortin, tremulacin, and condensed tannins was measured in the same trees. Overall I discovered evidence for a tradeoff between growth and salicortin/tremulacin, and a marginally significant but positive relationship between growth and condensed tannins.

The temperature trends and variations of the contiguous United States as a whole and ten designated regions were investigated from 1935 to 1986. To obtain reliable results, 263 stations of the Historical Climate Network (HCN) were used. The HCN stations are corrected for many non-climatic factors which may bias the data. The data for the contiguous United States reveals that the annual, summer, and winter temperatures are free of clear positive or negative trends. Unlike the annual and summer data, winter temperatures exhibit relatively strong variations. Each region was then studyed individually. The summer temperatures for all the ten regions were free of significant trends except Region 2 (Central East Region), which exhibited a significant negative trend. The winter temperatures of the ten regions also lack a statistical significance except for Region 3 (Southeast Region) which shows a significant negative trend. The annual temperatures for the ten regions were also significant except for Regions 2 and 5 (Central East Region and Southern Plains Region). These two regions exhibited significant negative trends. The annual temperature trends for nine of the ten regions were negative while the annual temperatures for the United States as a whole show a positive trend. None of these trends were significant except for Regions 2 and 5. To examine whether or not the differences between the trends of the contiguous United States as a whole and those of the ten regions represents a significant departure from each other, the Expansion Method was used. Applying this method on the annual, summer and winter trends indicated that these differences did not represent a significant departure from those of the contiguous United States. By studying the annual spatial temperature variations of the ten regions it was found that in more than 80% of the years, when the region with the highest positive deviation is in the western United States, the region with the highest negative deviation is in the eastern United States and visa versa.

In order to tend to the world’s dwindling freshwater supplies, sustainable alternative methods need to be integrated in order to keep up with the world’s increasing demand. Reclaimed water (RW) is one of the sustainable methods adopted by some Floridian cities such as Tampa, Tallahassee, and St. Pete that provide an alternative water source for non-potable uses. However, despite this alleviating effect RW has on freshwater supplies, it is crucial to recognize the potential harm it poses on neighboring waterbodies due to the residual contaminants it still contains, including Nitrogen (N) and Phosphorous (P). As such, studying residents’ knowledge and behavior about RW provides an insight into certain behavioral trends that potentially explain elevated levels of N and P in certain waterbodies. This study surveyed households living in the vicinity of Joe’s Creek Watershed and are using RW in irrigation provided by Pinellas County Utilities Department (PC) and the City of St. Pete Water Resources Department (SP). After looking at these residents’ yard practices, no harmful behavioral trend was observed to explicate the health of neighboring waterbodies. RW users are aware of the irrigation regulations set for them. However, weakness in information communication between city and County officials and RW users on fertilizer use and regulations was recorded. It is recommended that the city of St. Pete revisits their loose regulations on RW and the irrigation schedule set for their customers. More outreach material on fertilizer application and regulations need to be made available and accessible to the public.

It was almost four years ago when I first visited the Pomona College Organic Farm and since then I have learned everything from the basics of gardening to the complex steps required to organize students for events and activities. As I learned more and saw so many students come and go, I saw a need for written documentation that would allow future generations of students to benefit from the skills that my peers and I have learned in our time at the Farm. The value of the Farm is grounded in having a vibrant physical space, and right now the knowledge to maintain and improve this space is only passed down from person to person. I hope to eventually combine the disparate bits of knowledge that I have accumulated over the years into a single guidebook. This thesis project, which is the first major section of that guidebook, covers the Farm’s history and basic technical skills like soil preparation, planting, plant maintenance, weeding, pest control, and tool use. This is a living document and will be constantly updated as the Farm changes and grows and as new information comes to light. Although the Farm has come a long way over the years, it still has a lot of unrealized potential, and I hope that this document both facilitates and records the great changes that are soon to come.

To date, most studies on the fate and removal of endocrine disrupting compounds (EDCs) and pharmaceutical and personal care products (PPCPs) in wastewater focus on their fate in municipal wastewater treatment plants, and mostly under aerobic condition. There are limited studies related to anaerobic condition and (to our knowledge) no study on the removal of EDCs in landfill leachate by AnMBR. Moreover, for most studies under anaerobic condition, the removal of EDCs was only reported in the liquid phase; solid phase extraction was not reported, thereby preventing mass balance in the studies. This research was conducted to investigate the potential of AnMBR for reduction of organic strength and removal of EDCs in landfill leachate. A novel lab-scale upflow anaerobic sludge blanket (UASB) reactor equipped with dual-flat sheet ultrafiltration and microfiltration membrane modules was designed and constructed to test the potential to remove EDCs and traditional landfill leachate constituents (COD, turbidity). The target EDC was 17β-estradiol (E2), a prevalent female hormone used for contraceptives and hormone replacement therapy. Due to the nature of packaging and widespread use in households, the entry of E2 into landfills is highly likely, and has been reported. The quantification of E2 from liquid phase in this project is performed by the use of solid-phase microextraction (SPME) with GC/MS. Batch assays were conducted to determine the anaerobic biodegradability of E2 as well as to measure the respective distribution coefficients of E2 to PAC, colloids and anaerobic sludge biomass. In the adsorption batch assays, it was found that the PAC has stronger adsorption potential than anaerobic sludge. The adsorption potential of E2, E1 and EE2 on sludge follows the order E2>EE2>E1 which correlates to the Kow values (4.01, 3.67, 3.1, respectively). However, all three compounds showed the same adsorption potential to the Norit 20B PAC. The biodegradability of E2 was investigated in both liquid and solid phase and under several conditions such as methanogenesis, methanogenesis with aid from PAC, and methanogenesis with additional alternative electron acceptors added (sulfate and nitrate). E2 was found to transform to E1 under all tested conditions. The compounds are present in both liquid and solid phase. E2 and E1 were not detected (< 4ng/L and <10ng/L, respectively) in the liquid phase after 25 days in most cases except the case of adding additional sulfate. The AnMBR was designed, fabricated and operated for 2 years. During the stable condition period of the AnMBR, the high removal efficiencies of COD and E2 achieved were around 92% and 98%, respectively. However, E2 was still detected in the effluent at average concentrations of 30-40 µg/L range. To expand hormone retention and removal by the AnMBR, as well as to control membrane fouling, powder activated carbon (PAC) was added to the reactor. After the PAC was added, the concentration of E2 was reduced to less than the detection limit (4ng/L) in both MF and UF effluents. The log removal of E2 in the AnMBR system increased immediately from 1.7 without PAC to 5.2 after PAC was added. This study demonstrated that the AnMBR has high potential for removal of E2, and with aid from PAC, the AnMBR can remove E2 from landfill leachate to levels below detection limit.