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ELECTROCHEMICAL CHARACTERIZATION OF FREE AND COMPLEXED FLUORIDES IN DRINKING WATER AND THE EFFECTS OF ALUMINUM AND IRON ON FLUORIDE INCORPORATION INTO TOOTH ENAMELKELADA, NABIH PHILOBBOS January 1972 (has links)
DISSERTATION (PH.D.)--THE UNIVERSITY OF MICHIGAN
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THE RELATIONSHIP BETWEEN SERUM AND URINE METALLOTHIONEIN, RENAL FUNCTION, PROTEIN EXCRETION PATTERNS AND OCCUPATIONAL CADMIUM EXPOSUREFALCK, FRANCIS YTTERGREN, JR. January 1982 (has links)
DISSERTATION (PH.D.)--THE UNIVERSITY OF MICHIGAN
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Impact of Exposure to Weathered Crude Oil and Accumulation of PAHs in Crawfish (Procambarus clarkii)Chichester, Brittany Lynn 22 January 2016 (has links)
The number of pipelines transporting crude oil and other refined petroleum products across the U.S. has increased 15.4% from 2004 to 2013. In Louisiana, over 3,450 miles of liquid petroleum pipelines crisscross the state. In January 2013, crude oil was accidentally released from an underground pipeline into Bayou Sorrel, Louisiana. This freshwater wetland is located within the Atchafalaya River Basin which is home to large populations of wild crawfish that could be impacted by the crude oil released. This study aims to assess the potential lethal impacts that crude oil spill may have produced in adult crawfish (P. clarkii) and determine if the hepatopancreas will accumulate polycyclic aromatic hydrocarbons (PAHs) during exposure. Adult crawfish exposed for 96 hours to sediment contaminated with weathered crude oil concentrations of 30,000 ppm were determined to have a survival rate of no less than 87.7%. A modified QuEChERS extraction, dispersive solid-phase cleanup and a GC-MS system was used to quantitate the concentrations of PAHs in the crawfish hepatopancreas tissue. The PAH concentrations increased with increasing oil treatment level, but were not above a level of concern used by the FDA to assess PAH contamination in shrimp and crabs after the Deepwater Horizon Oil Spill event. Therefore it is unlikely that the crawfish in this study would be deemed unsafe for human consumption.
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Economic assessment of best management practices in the Mara River Basin : toward implementing payment for watershed servicesAtisa, George 08 May 2009 (has links)
The Mara River in East Africa is currently experiencing poor water quality and increased fluctuations in seasonal flow. This study investigated technically effective and economically viable Best Management Practices for adoption in the Mara River Basin of Kenya that can stop further water resources degradation.
A survey of 155 farmers was conducted in the upper catchment of the Kenyan side of the river basin. Farmers provided their assessment of BMPs that would best suit their farm in terms of water quality improvement, economic feasibility, and technicalsuitability. Cost data on different practices from farmers and published literature was collected. The results indicated that erosion control structures and runoff management practices were most suitable for adoption. The study estimated the total area that would be improved to restore water quality and reduce further water resources degradation. Farmers were found to incur losses from adopting new practices and would therefore require monetary support.
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Rainfall variability in the upper Napo River Basin, Ecuadorian AmazonAyabaca, Marcelo Vicente 02 April 2004 (has links)
The purpose of this research was to investigate the influence of elevation and other terrain characteristics over the spatial and temporal distribution of rainfall. A comparative analysis was conducted between several methods of spatial interpolations using mean monthly precipitation values in order to select the best. Following those previous results it was possible to fit an Artificial Neural Network model for interpolation of monthly precipitation values for a period of 20 years, with input values such as longitude, latitude, elevation, four geomorphologic characteristics and anchored by seven weather stations, it reached a high correlation coefficient (r=0.85). This research demonstrated a strong influence of elevation and other geomorphologic variables over the spatial distribution of precipitation and the agreement that there are nonlinear relationships. This model will be used to fill gaps in time-series of monthly precipitation, and to generate maps of spatial distribution of monthly precipitation at a resolution of 1km2.
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An Assessment of Metal Profiles in Sediments from Mississippi River Estuaries and Offshore Shoaling RegionsRockett, Hannah Paula 06 July 2017 (has links)
Sediment contamination poses a significant problem within aquatic systems. Metals as a pollutant are a major concern because of their toxicity, persistence and non-degradable nature. This study measured sediment metal concentrations within Louisianas coastal estuaries and offshore shoaling regions over a three year period. This was done to determine current concentrations, examine the relationships of physico-chemical, spatial and temporal variables with the metals and compare the metal concentrations to established Sediment Quality Values (SQVs). Variables and physico-chemical parameters were run in a comprehensive statistical model to determine variable contribution to the variation of each metal concentration. Moisture content and organic matter were the two physico-chemical variables that were significant among most of the metals within the study. Spatial variables were also found to be significant, with inshore transects having higher concentrations for most metals with the exception of Cd, which was higher offshore. More specifically the highest concentrations occurred at the Atchafalaya and Breton Sound transects for most metals. There were two temporal variables, year and season. Concentrations decreased for five metals and increased for three over the three year period of this study. Both the summer and fall seasons had higher concentrations than the spring season within the season variable. Lastly, metal concentrations between locations that were oiled and those that were non-oiled during the Deepwater Horizon oil spill were compared. Cobalt had statistically higher concentrations at locations allocated oiled, while Cu had higher concentrations at locations labeled non-oiled. Most metal concentrations in this study were below their respective SQVs, which are used by federal agencies to screen sediments for toxicity.
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Knowing the influence environmental, spatial and temporal variables have on metal concentrations is useful in the assessment of sediment quality specifically when environmental disasters, such as hurricanes or oil spills, repeatedly occur. Determining if the levels of metals have toxic effects on aquatic systems, organisms and humans is a critical first step. This study, the first comprehensive assessment of metals in Mississippi River estuarine sediments, has contributed to developing effective management strategies to control sediment pollution in coastal Louisiana and deltaic systems worldwide.
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Particulate Matter and Ozone: Remote Sensing and Source AttributionKim, Sungshik 17 July 2015 (has links)
Particulate matter (PM) and tropospheric ozone are air pollutants that are harmful to human health and have broad implications for climate. Despite their importance, there remain large uncertainties related to their sources, evolution in the atmosphere, and impact downwind. In this thesis, I work to address some of these uncertainties through integrated analysis of ground, aircraft, and satellite observations and using both forward and inverse modeling approaches.
A new, high-resolution database of ozone-CO correlations was developed from two separate satellite platforms and was validated against in-situ profiles of the trace gases from commercial aircraft. These correlations were interpreted with a state-of-the-science global chemical transport model (CTM) to infer constraints on ozone sources. The observations supported the major source representation in the model for polluted North American outflow in June-July-August (combustion sources) and for the observed ozone maximum in the South Atlantic during December-January-February (lightning). A major model discrepancy was revealed over the North Pacific in summer and fall that was related to an overestimate of the natural lightning source and an underestimate of East Asian anthropogenic emissions.
Land clearing by fire in Equatorial Asia pollutes the air shed of one of the most densely populated regions in the world, but fires set in different areas have very different public health implications depending on the population downwind. Smoke exposure sensitivity to Equatorial Asian fires for several receptor locations was calculated with the adjoint of a global CTM. Peatswamp fires in southern Sumatra were found to be particularly detrimental to public health for all years studied, implying that an effective land management policy protecting the remaining peatswamp forests would be of great air quality benefit. This approach can be used to estimate PM exposure for any future fire emission scenario and can be used to provide guidance for targeted land conservation in Equatorial Asia.
We use an ensemble of surface, aircraft, and satellite observations over the Southeast US during the summer-fall of 2013 together with the GEOS-Chem CTM at high resolution to better understand aerosol sources in the region and the relationship between surface PM and aerosol optical depth (AOD). Sulfate and organic aerosol (OA) are the main contributors to surface PM2.5 (mass concentration of PM finer than 2.5 μm aerodynamic diameter) and AOD over the Southeast US, with OA acquiring an increasing role over the past decade as anthropogenic emissions have declined. Biogenic isoprene and monoterpenes are the dominant source of OA, and may contribute to sulfate formation through the production of Criegee intermediates as SO2 oxidants. The vertical profile of aerosol extinction over the Southeast US follows closely that of aerosol mass. The SEAC4RS aircraft data demonstrate that the AODs measured from space are fundamentally consistent with surface PM2.5. This implies that satellites can be used reliably to infer PM2.5 air quality if a good CTM representation of the aerosol vertical distribution is available. / Earth and Planetary Sciences
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Stable Water Isotopes as Tracers in Global PrecipitationMoore, Mary 25 July 2017 (has links)
Stable water isotopes (H2O, H18O, and HDO) are incorporated into the microphysics schemes of two different atmospheric models. This thesis describes the use of these molecules as tracers in precipitation budgets to assess the processes controlling the isotopic signatures of precipitation in the tropics and orographic snow in the mid-latitudes.
The idealized simulations of seasonal precipitation budgets in the tropics determine that increased vapor convergence during intense precipitation is most important for setting the isotopic composition of the convective precipitation. The isotopic signal of the converged vapor is more important than the local evaporation and smaller scale post-condensational processes.
Flow over a 2D-mountain and realistic simulations of orographic clouds show that the isotopic signature of precipitation is more sensitive to changes in mountain height and initial temperature profiles than to the cloud droplet number concentration. Riming of cloud liquid and vapor deposition onto ice are the largest source terms for orographic precipitation, and have distinct isotopic signatures that are altitude-dependent. When riming is the larger source term, precipitation tends to be more enriched than when vapor deposition dominates. / Earth and Planetary Sciences
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Utilizing Marginalized Land for the Development of Symbiotic Waste-to-Energy Mini Grids in Remote IslandsGeorgoulias, Nikolaos 11 January 2016 (has links)
Remote islands face increasingly pressing constraints in their efforts to satisfy their waste management, energy, and water needs in a sustainable manner. Their small scale and isolated context restrict the availability of natural resources and infrastructure commonly available in mainland regions, which facilitates an adverse dependency on imports and exclusive use of landfilling. This thesis aims to investigate systemic solutions to the waste management, energy and water problems encountered by insulated communities. Analysis evaluates the benefits and costs of a novel network based on a waste-to-energy facility against the business-as-usual methods in the region of the Northern Aegean Sea in Greece. The economic, social, and environmental sustainability of the two systems is evaluated through a cost-benefit analysis, using a comprehensive set of economic, environmental, and social indicators. Two main alternatives were investigated; an ENERGOS gasification plant and an Enerkem waste-to-biofuels plant. Results show that the current system is economically and environmentally unsustainable and that substantial benefits are achieved through the development of the proposed network. The results also revealed that the possibility to produce biofuels is not only the most economically, environmentally and socially feasible alternative, but also fosters several synergies and the development of a circular economy at the regional scale. The results of the analysis facilitate prudent decision-making with regard to natural resource management in island regions and can be utilized by other groups of islands with similar waste generation levels and challenges.
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Sustainability in the Apparel Industry: Improving How Companies Assess and Address Environmental Impacts Through a Revised Higg Index Facility ModuleConnolly, Clare B. 11 January 2016 (has links)
This study was focused on analyzing the Facility Environmental Module (FEM) of the Sustainable Apparel Coalition’s (SAC) Higg Index. The research objectives were twofold: 1) to test whether the indicators featured in the FEM could accommodate the data requirements for calculating environmental impacts of apparel products, and 2) to identify if the FEM indicators could satisfy the data and information needs of other key stakeholder groups.
The long track record of irresponsible social and environmental practices in the apparel industry began gaining more attention in the press toward the end of the 20th century. Since then, many companies have been prompted to introduce sustainability practices in response to business-threatening criticisms. While these measures helped companies manage their supply chains better, for the most part the improvements remained at the scale of individual companies, limiting their effectiveness in implementing systemic change in the apparel industry.
The potential for improving sustainability across the industry rests in the ability for apparel companies to engage collaboratively toward the common goal. Helping to facilitate this objective is the Higg Index, the SAC’s self-assessment suite of tools. The Index is presently composed of three modules, which use a standardized scoring methodology to rate the performance of an apparel company’s brand, facilities, and products, respectively. One of the issues with the current state of the Index is the lack of connectivity between the product and facility modules. Because the processes conducted at the facility level have a direct impact on the embedded impacts of the product, it is important to consider these factors when assessing the lifecycle implications of a given product.
The second issue considered in this study is that facilities are often confronted with external pressures to report, comply, and seek certifications related to environmental performance. In practice, this requires completing data and information requests similar to those of the Higg Index. However, these tasks can be burdensome for facility managers who may need to gather data from multiple sources. If the FEM and other Higg Index modules were structured in such a way that they could reduce the time and effort required to complete other requests for information they would likely be more easily adopted.
A gap analysis approach was used to test the FEM’s ability to yield valuable data for product LCAs and to understand its potential synergies with other data and information requests. First, the metrics that could be expected from a completed FEM were compared against the requirements of the product LCA methodology using a restructured excel file. This file featured all FEM key performance indicators (KPI) and included dedicated columns for mapping the criteria for data needed by each LCA impact category methodology. The second test involved using a similar excel-based tool to assess the equivalencies between the FEM KPIs and those featured in two example external frameworks: the Fair Trade Product Standard and the Cradle to Cradle Standard.
Based on the results of these gap analyses, it became clear that there is significant potential to improve the assessment of facilities’ performance through the introduction of more quantitative KPIs. This would be required to calculate relative impacts for product LCAs and it would also help facilities gain a better understanding of their performance. It is therefore recommended that the SAC reassess the KPIs featured in the FEM and request more quantitative metrics. Additionally, continuing to evaluate the equivalencies of other sustainability frameworks may help the SAC to identify common KPIs that are asked by external organizations but not included in the FEM. These elements could then be incorporated into a future version of the FEM for a more comprehensive assessment of facility environmental performance.
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