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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
371

Assessing Public Health Burden Associated with Exposure to Fine Particulate Matter (PM2.5): The Impacts of Model Resolution and Exposure-Response Relationship on Mortality Estimates

Li, Ying 01 November 2014 (has links)
No description available.
372

Eelgrass (Zostera marina) Population Decline in Morro Bay, CA: A Meta-analysis of Herbicide Application in San Luis Obispo County and Morro Bay Watershed

Sinnott, Tyler King 01 November 2020 (has links)
The endemic eelgrass (Zostera marina) community of Morro Bay Estuary, located on the central coast of California, has experienced an estimated decline of 95% in occupied area (reduction of 344 acres to 20 acres) from 2008 to 2017 for reasons that are not yet definitively clear. One possible driver of degradation that has yet to be investigated is the role of herbicides from agricultural fields in the watershed that feeds into the estuary. Thus, the primary research goal of this project was to better understand temporal and spatial trends of herbicide use within the context of San Luis Obispo (SLO) County and Morro Bay Watershed by analyzing data of application by mass, area, and intensity to identify herbicides with the highest potential for local environmental pollution. California Pesticide Use Annual Summary Reports (PUASR) from the years 2000 to 2017 were used to obtain data for conducting a meta-analysis to estimate total herbicide application by weight within every township, range, and section for each of the eight selected herbicides: oxyfluorfen, glyphosate, diuron, chlorthal-dimethyl, simazine, napropamide, trifluralin, and oryzalin. A second goal was to select an analytical laboratory that would be best suited for herbicide analysis of estuary sediments to determine the presence, or lack thereof, of the eight selected herbicides. Criteria of consideration in laboratory selection included herbicides detection capabilities, detection/reporting limits, testing prices, chain of custody protocols, turnaround times, and laboratory site locations. The meta-analysis yielded results showing high herbicide application rates in SLO County with glyphosate, oxyfluorfen, and chlorthal-dimethyl being identified as three herbicides of elevated risk for local environmental contamination due high rates of use by mass, by area, and/or intensity during the study timeframe. Additionally, Morro Bay Watershed exhibited moderate rates of herbicide application with chlorthal-dimethyl and glyphosate being of highest risk for contamination and accumulation within the estuary because of high application rates by mass, by area, and/or intensity. Finally, Environmental Micro Analysis (EMA) and Primus Group, Inc. (PrimusLabs) were identified as the top candidates for analytical laboratory testing of Morro Bay Estuary sediment samples to be obtained and tested for the selected herbicides. These laboratories provide superior analytical capabilities of the eight herbicides, impressive reporting limits or lower detection limits, competitive testing prices for detecting multiple constituents in multiple samples, robust chain of custody protocols, options for quick turnaround times, and laboratory site locations within California.
373

Novel Image-Based Methods for Quantitative Real Time Environmental Monitoring

January 2019 (has links)
abstract: Environmental pollution has been one of the most challenging problems in modern society and more and more health issues are now linked to environmental pollution and especially, air pollution. Certain sensitive group like patients with asthma are highly influenced by the environmental air quality and knowledge of the daily air pollution exposure is of great importance for the management and prevention of asthma attack. Hence small form factor, real time, accurate, sensitive and easy to use portable devices for environmental monitoring are of great value. Three novel image-based methods for quantitative real time environmental monitoring were introduced and the sensing principle, sensor performances were evaluated through simulation and field tests. The first sensing principle uses surface plasmon resonance (SPR) image and home-made molecular sieve (MS) column to realize real time chemical separation and detection. SPR is sensitive and non-specific, which makes it a desirable optical method for sensitive biological and chemical sensing, the miniaturized MS column provides small area footprint and makes it possible for SPR to record images of the whole column area. The innovative and system level integration approach provide a new way for simultaneous chemical separation and detection. The second sensor uses scattered laser light, Complementary metal-oxide-semiconductor (CMOS) imager and image processing to realize real-time particulate matter (PM) sensing. Complex but low latency algorithm was developed to obtain real time information for PM including PM number, size and size distribution. The third sensor uses gradient based colorimetric sensor, absorbance light signal and image processing to realize real-time Ozone sensing and achieved high sensitivity and substantially longer lifetime compared to conventional colorimetric sensors. The platform provides potential for multi-analyte integration and large-scale consumer use as wearable device. The three projects provide novel, state-of-the-art and sensitive solutions for environmental and personal exposure monitoring. Moreover, the sensing platforms also provide tools for clinicians and epidemiologists to conduct large scale clinical studies on the adverse health effects of pollutants on various kinds of diseases. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2019
374

Land Use and Land Cover, 1976-78. Johnson City, Tennessee.

United States Geological Survey 01 January 1983 (has links)
Published in 1983 by the U.S. Geological Survey, this map denotes land use and land cover in the northeast Tennesee/Johnson City area for the years 1975-83. Base map from U.S. Geologic Survey, 1966. The legend along the right edge denotes different types of land use and coverage using a numeric code. Additional details on how the map was compiled can by found on the lower right corner. The North Carolina portion of this map was prepared in cooperation with the North Carolina Department of Natural Resources and Community Development. Physical copy resides in the Government Information, Law and Maps Department of East Tennessee State University’s Sherrod Library. Scale - 1: 250,000. / https://dc.etsu.edu/rare-maps/1044/thumbnail.jpg
375

Automated mapping of oblique imagery collected with unmanned vehicles in coastal and marine environments

Freeman, Jacob B. 12 May 2023 (has links) (PDF)
Recent technological advances in unmanned observational platforms, including remotely operated vehicles (ROVs) and small unmanned aerial systems (sUAS), have made them highly effective tools for research and monitoring within marine and coastal environments. One of the primary types of data collected by these systems is video imagery, which is often captured at an angle oblique to the Earth’s surface, rather than normal to it (e.g., downward looking). This thesis presents a newly developed suite of tools designed to digitally map oblique imagery data collected with ROV and sUAS in coastal and marine environments and quantitatively evaluates the accuracy of the resultant maps. Results indicate that maps generated from oblique imagery collected with unmanned vehicles have highly variable accuracy relative to maps generated with imagery data collected with conventional mapping platforms. These results suggest that resultant maps have the potential to match or even surpass the accuracy of maps generated with imagery data collected with conventional mapping platforms but realizing that potential is largely dependent upon careful survey design.
376

Optimizing edge-of-field water quality monitoring methods to determine the effects of best management practices on nutrient and sediment runoff

Hill, Mark 08 August 2023 (has links) (PDF)
This study investigates the impact on water quality of combined agricultural best management practices cover crop and minimum tillage, alongside an examination of techniques used to collect those samples. Edge-of-field (EOF) water quality samples were collected from 11 working farms during a two-year paired field experiment. Results showed significant reductions in nutrient concentrations, increased discharge, and mixed findings regarding nutrient mass transport post-treatment. A suite of EOF collection techniques were compared using in-situ automated water sampling systems sampling the same runoff events. Sampling protocols influenced nutrient concentrations in composite samples, but unexpected variance in velocity sensors affected measured discharge, making it challenging to confidently attribute differences in nutrient loading estimates to sampling protocol. The findings provide regionally specific evidence for mitigating on-farm nutrient enrichment in the Lower Mississippi Alluvial Valley and enhancing monitoring techniques.
377

Monitoring of Selected Bacteriological Parameters Associated with the Sinking Creek Total Maximum Daily Load (TMDL).

Dulaney, Douglas Ron 01 August 2003 (has links) (PDF)
Sinking Creek, a stream in northeast Tennessee, was added to the state 303 (d) list and a TMDL for fecal coliforms developed. The study objectives were to 1) identify areas in Sinking Creek with elevated levels of fecal coliforms and 2) compare data collected to results from watershed models used in the TMDL. Fourteen sites on Sinking Creek were monitored monthly and concentrations of total coliforms, fecal coliforms, and selected physical water quality parameters measured. Fecal coliform concentrations were >1000 CFU/100 ml at sites 1 through 4, and <400 CFU/100 ml, at all other sites indicating significant inputs between sites 4 and 5. Comparisons of results from Monte Carlo simulations and watershed models indicated geometric means listed in the TMDL were on average 64% higher than results from simulations calibrated with collected data. Proposed Best Management Practices (BMP’s) included; septic tank surveys, and the use of vegetative buffer zones.
378

SPATIAL INTERPOLATION OF HEAVY METAL CONCENTRATIONS IN SOILS OF BUMPUS COVE, TN

Magno, Melissa A, Luffman, Ingrid, Nandi, Arpita, Evanshen, Brian G 05 April 2018 (has links)
Mining processes generate waste rock, tailings, and slag that can increase heavy metal concentrations in soils. Un-reclaimed, abandoned mine sites are particularly prone to leaching these contaminants, which may accumulate and pose significant environmental and public health concerns. The characterization and spatial delineation of heavy metals of such soils is vital for risk assessment and soil reclamation. Bumpus Cove, once one of the richest mineralized districts of eastern TN, is home to at least 47 abandoned, un-reclaimed mines that were all permanently closed by the 1950s. This study evaluated 52 soil samples collected within a 0.67 km2 study area containing 6 known abandoned Pb, Zn, and Mn mines at the headwaters of Bumpus Cove Creek for heavy metal concentrations. Soil samples were analyzed for Zn, Mn, Pb, Cu, and Cd by means of microwave-assisted acid digestion and flame atomic absorption spectrometry (FAAS). Using the measured values and digital elevation model (DEM) derived from lidar data, ordinary kriging and cokriging interpolation techniques were used to predict the trend of heavy metal concentrations throughout the study area. Concentrations for Zn, Mn, and Pb show significant variability between sample sites (ranges of 12 – 1,354 mg/kg Zn, 6 – 2,574 mg/kg Mn, 33 – 2,271 mg/kg Pb). Cu and Cd were much less variable, with ranges of 1 - 65 mg/kg and 7 – 40 mg/kg, respectively. Of the measured heavy metals, only Zn and Pb exceed permissible limits in soils. Results show that ordinary kriging interpolation methods produced improved results over ordinary cokriging with and without lognormal transformations for all metals. Mn and Pb were found to transport further downhill following the natural drainage, whereas Zn, Cu and Cd concentrations exhibit localized variability without a clear transportation path. This study can provide a reference for state and local entities responsible for heavy metal monitoring in Bumpus Cove, TN.
379

The influence of marsh edge and seagrass habitat on summer fish and macroinvertebrate recruitment to a northern Gulf of Mexico coastal system

Gilpin, Rebecca Lea 12 May 2023 (has links) (PDF)
Marshes and seagrass beds have been widely recognized as important habitat for estuarine species, but less has been done on how these habitats interact and function together, thereby limiting understanding of the variability of juvenile recruitment to coastal systems. Therefore, the objective of this study was to assess the interaction between fringing marsh and adjacent seagrass for the provision of habitat for juvenile nekton. Weekly seine net and benthic seagrass core sampling from June to November 2020 determine the relationship between nekton and marsh-edge and seagrass habitat. This study shows disparate results, in terms of the effects of proximity to marsh edge and seagrass biomass on nekton abundance and size, pointing to different selectivity of marsh edge versus seagrass by different species. In addition, there are no effects of proximity to marsh edge and seagrass biomass on community composition, but an interactive effect on community dispersion.
380

Differential toxicity of PM2.5 components and modified health effects modeling: A case study in Nepal

Brownholtz, Jeremy 03 April 2023 (has links)
During the latter part of the 20th century, a transition away from coal as a major energy source in developed countries was accompanied by a notable decrease in air pollution-related deaths in those countries. Currently the same phenomenon is being observed in developing nations like China and India. However, many areas that do still rely on coal for their energy production or industrial needs also reflect a gap in research on the effects of those specific processes on local populations. Located in Nepal at the foot of the Himalayan Plateau, Kathmandu represents one such location. The local economy of Kathmandu and the surrounding area relies heavily on the production of bricks using coal-fired kilns, which produce large amounts of particulate matter. This particulate matter contains a characteristic mix of metals. This unique fingerprint can be used to identify and track kiln emissions in ambient samples. We collected hourly samples of ambient metal concentrations over a period of three months at the start of 2019. We then used these data to perform positive matrix factorization (PMF) to identify several factors contributing to the ambient air pollution of the sampled area, each representing a source type. The PMF output included the chemical ‘fingerprint’ of each factor as well as hourly variation of each factor. We were able to isolate the fraction of PM2.5 contributed by coal and estimate the health effects attributable to this fraction using a modified risk ratio of 1.05 to reflect the higher toxicity of coal emissions. We found that the current estimates of health impacts in Nepal underestimate the true impact of coal by 416 deaths per year.

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