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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.
151

A Comparison of Rainwater Harvesting Tank Sizing Methods: Optimizing to Reduce Greenhouse Gas Emissions versus Maximizing System Reliability

Rodriguez, Henry 21 December 2018 (has links)
No description available.
152

An analysis of strategy plan on business performance of a water utility : a Midvaal water company case study / Erven Sello Malatji

Malatji, Erven Sello January 2014 (has links)
The purpose of the research was to assess the strategic management process of a water utility in South Africa. The research focused on Midvaal Water Company, a section 21 water utility based in South Africa, North West Province town of Klerksdorp. The objectives of the study were; (a) to assess the organisational level of knowledge when it comes to SMP, (b) to determine different perceptions with regards to SMP between management and employees, (c) to determine the organisational profiles (age, gender, educational qualifications, race and employment type). Literature review was conducted covering the South Africa water framework paying particular attention to different role players and legislative framework governing the sector; the latter included the strategic management process of a water utility as applied in the Midvaal Water Company context. The research approach was quantitative methodology, which involved distribution of questionnaires as part of field work in the water utility. Questionnaires were analysed through statistical approach, and further linked back to the problem statement. The questionnaires were also tested for Validity and reliability which was found to be acceptable. The results indicate that there is a correlation between strategic management process and organisational results. The results also provide interesting relationships between variables that can be explored further. In conclusion successful implementation of strategy requires both leadership and employee commitment. More effort needs to be put in place to ensure that there is an understanding of company values mission and vision. As part of the succession planning the water utilities should consider succession planning as a tool to develop future leaders, by identifying future potential leaders and involving them in the strategy crafting process can help in creating a pool of competent future leaders that will contribute to the well being and sustainability of the water utility. / MBA, North-West University, Potchefstroom Campus, 2015
153

An analysis of strategy plan on business performance of a water utility : a Midvaal water company case study / Erven Sello Malatji

Malatji, Erven Sello January 2014 (has links)
The purpose of the research was to assess the strategic management process of a water utility in South Africa. The research focused on Midvaal Water Company, a section 21 water utility based in South Africa, North West Province town of Klerksdorp. The objectives of the study were; (a) to assess the organisational level of knowledge when it comes to SMP, (b) to determine different perceptions with regards to SMP between management and employees, (c) to determine the organisational profiles (age, gender, educational qualifications, race and employment type). Literature review was conducted covering the South Africa water framework paying particular attention to different role players and legislative framework governing the sector; the latter included the strategic management process of a water utility as applied in the Midvaal Water Company context. The research approach was quantitative methodology, which involved distribution of questionnaires as part of field work in the water utility. Questionnaires were analysed through statistical approach, and further linked back to the problem statement. The questionnaires were also tested for Validity and reliability which was found to be acceptable. The results indicate that there is a correlation between strategic management process and organisational results. The results also provide interesting relationships between variables that can be explored further. In conclusion successful implementation of strategy requires both leadership and employee commitment. More effort needs to be put in place to ensure that there is an understanding of company values mission and vision. As part of the succession planning the water utilities should consider succession planning as a tool to develop future leaders, by identifying future potential leaders and involving them in the strategy crafting process can help in creating a pool of competent future leaders that will contribute to the well being and sustainability of the water utility. / MBA, North-West University, Potchefstroom Campus, 2015
154

Advancing Methods to Measure the Atmospheric CO2 Sink from Carbonate Rock Weathering

Salley, Devon, Mr. 01 April 2016 (has links)
With rising atmospheric CO2 concentrations, a detailed understanding of processes that impact atmospheric CO2 fluxes is required. While a sink of atmospheric carbon from the continents to the ocean from carbonate mineral weathering is, to some degree, offset by carbonate mineral precipitation in the oceans, efforts are underway to make direct measurements of these fluxes. Measurement of the continental sink has two parts: 1) measurement of the dissolved inorganic carbon (DIC) flux leaving a river basin, and 2) partitioning the inorganic carbon flux between the amount removed from the atmosphere and the portion from the bedrock. This study attempted to improve methods to measure the DIC flux using existing data to estimate the DIC flux from carbonate weathering within the limestone karst region of south central Kentucky. The DIC flux from the Barren River drainage basin upstream from Bowling Green in southern Kentucky and northern Tennessee, and the upper Green River drainage basin, upstream from Greensburg, Kentucky, was measured, each for a year, using U.S.G.S. discharge data and water-chemistry data from municipal water plants. A value of the (DIC) flux, normalized by time and area of carbonate rock, of 4.29 g km-3 day-1 was obtained for the Barren River, and 4.95 kg km-3 for the Green. These compared favorably with data obtained by Osterhoudt (2014) from two nested basins in the upper Green River with values of 5.66 kg km-3 day-1 and 5.82 kg km-3 day-1 upstream from Greensburg and Munfordville, respectively. Additional normalization of the values obtained in this study by average precipitation minus evapotranspiration over the area of carbonate rock, or water available for carbonate dissolution, resulted in values of 5.61x107 g C (km3 H20)- 1 day-1 (grams of carbon per cubic kilometer of water, per day) for the Barren, and 7.43x107g C (km3 H20)-1 day-1 for the Green River. Furthermore, a statistical relationship between the total DIC flux and time-volume of water available for dissolution has been observed, yielding an r2 value of 0.9478. This relationship indicates that the primary variables affecting DIC flux for these drainage basins are time and the volume of water available for dissolution.
155

An Adaptive Visual Learning Approach for Waterborne Disease Prevention in Rural West Africa

Oglesby, Jonathan Le Mar 01 April 2016 (has links)
Depleted water supplies, along with industrial and human waste, are driving a world water crisis that poses a growing risk to food markets, energy production, political stability, and human health (Global Water Security 2012). One obvious example of the this crisis is the more than 1 billion people who obtain their drinking water from contaminated sources (WHO/UNICEF 2006; Clasen et al. 2008). With a projected increase of 1.3 billion people between now and 2050, Africa will add more to the global population than any other world region (Haub and Kaneda 2013). For this research, visual learning design factors were incorporated into water literacy materials in order to study ways in which cultural and societal barriers can be overcome through culture- and gender-appropriate graphics designed to foster visual storytelling in the West African country of Niger. Women were targeted as the study population since they are the primary water fetchers and handlers in sub-Saharan Africa. Eye-tracking technology and GIS tools were used for quantification of the visual design characteristics. Research was conducted in 23 villages along the Niger River, and included 510 interviews, 693 focus group participants, 9 different cultural groups, over 30 hours of audio interviews, and 464 eye-tracking trials. Tobii X2-60 eye-tracking equipment was used in bush maternity wards, medicinal depositories, and mud-brick homes. Eye-tracking data were imported into an ArcGIS platform, where kernel density estimation (KDE) analyses were performed in an effort to compare and contrast the KDE of varying education levels, age groups, ethnic groups, and village types. Spatial autocorrelation analyses were used to evaluate whether the spatial pattern of attribute values (fixation time) was clustered, dispersed, or random. Results from this research suggest that visual communication can be used to overcome low education and cultural barriers for waterborne disease prevention. Using an adaptive visual-learning approach for the research method provided a creative alternative to conventional water-education materials, as most do not consider mother tongue and low literacy. Through visual communication, a novel way has been developed to understand how disadvantaged populations in sub-Saharan Africa visually process water literacy materials.
156

Mobility of <em>Escherichia coli</em> within Karst Terrains, Kentucky, USA

Bandy, Ashley M. 01 January 2016 (has links)
Bacterial contamination of karst aquifers is a concern as water quality across the globe deteriorates in the face of decreasing water security. This study examined the transport and attenuation of two non-virulent isolates of Escherichia coli in relation to traditional groundwater tracers such as rhodamine WT dye and latex microspheres in two karst regions in Kentucky. Differential movement between the four tracers was observed in both epikarst and karst aquifer traces, with differences in behavior dependent on flow conditions. Attenuation was greater for the bacterial isolate containing the iha gene, compared to the isolate containing the kps gene. Microspheres of comparable size (1 µm diameter) were more easily remobilized during increases in discharge during the observed periods for both study sites. Bacteria were remobilized during storm events over 1 month after injection. Recoveries of tracers that were < 100% combined with observed remobilization during storm events illustrate the storage capacity of epikarst and karst aquifers with regard to potential contaminants.
157

Energy-water nexus : sustainability of coal and water resources

Hebel, Anna Kathleen 01 November 2010 (has links)
Energy and water are two precious natural resources with which demand will continue to grow with increased population growth. Coal provides a cheap and abundant source of energy but with important environmental effects on air and water. An analysis of the current coal production in Texas, one of the leading providers of energy in the United States, will be discussed along with the possibility of creating a coal-to-liquids market in Texas from existing and future coal mining operations. An in-depth discussion into the water requirements for traditional coal production and coal-to-liquids will assist in analyzing its possible production and sustainability. / text
158

Impacts of Transportation Infrastructure on Stormwater and Surface Waters in Chittenden County, Vermont, USA

Bartlett, Joseph Hollis 01 January 2016 (has links)
Transportation infrastructure is a major source of stormwater runoff that can alter hydrology and contribute significant loading of nutrients, sediment, and other pollutants to surface waters. These increased loads can contribute to impairment of streams in developed areas and ultimately to Lake Champlain. In this study we selected six watersheds that represent a range of road types (gravel and paved) and road densities (rural, suburban, and urban) present in Chittenden County, one of the most developed areas in Vermont. The location and density of road networks were characterized and quantified for each watershed using GIS analysis. Monitoring stations in each watershed were constructed and instrumented to measure discharge and water quality parameters continuously from spring through early winter. Storm event composite samples and monthly water chemistry grab samples were collected and analyzed for total nitrogen, total phosphorus, chloride, and total suspended sediments. Results from this study show that road type and road density are closely linked with the level of impairment in each watershed. Total phosphorus and total nitrogen from storm event composite samples and monthly grab samples significantly increased along a gradient of increasing road network density. Chloride concentrations increased several orders of magnitude along this same gradient. With the exception of Alder Brook where total suspended sediment (TSS) concentrations tended to be high, there were no significant differences in TSS concentrations between rural and developed watersheds. The elevated storm event TSS concentrations in the rural streams suggest that the unpaved roads in the rural watersheds contribute to stormwater runoff loads and that sediment control, at least in the developed watersheds, might be fairly effective. The overall results from this study show that local roads are a significant source of impairment for streams in the Chittenden County area. Most of these roads are municipal roads that are not under management of the Vermont Agency of Transportation. Thus, local actions will be necessary to reduce runoff and pollutant loading from these roads.
159

Measurement and modeling of stormwater from small suburban watersheds in Vermont

Nipper, Joel 01 January 2016 (has links)
Despite decades of U.S. water quality management efforts, over half of assessed waterbody units were threatened or impaired for designated uses in the most recent assessments, with urban runoff being a leading contributor to those impairments. This cumulative research explores several aspects of urban runoff dynamics through a combination of field study and modeling. Stormwater ponds are ubiquitous in developed landscapes due to their ability to provide multiple forms of treatment for stormwater runoff. However, evolving design goals have reduced the applicability of much of the early work that was done on pond effectiveness. In this study, we instrumented a recently constructed detention pond in Burlington, VT, USA. Flow gaging demonstrated that the pond achieved a 93% reduction in event peak flow rates over the monitoring period. Storm sampling showed that the pond significantly reduced total (TN) (1.45 mg/L median influent, 0.93 mg/L median effluent, p < 0.001) and total phosphorus (TP) (0.498 mg/L median influent, 0.106 mg/L median effluent, p < 0.001) concentrations over the events sampled. A loading analysis estimated the TN and TP removal efficiencies for the pond to be 23% and 77% respectively. Lastly, temperature data collected from the pond showed that during the summer the pond accumulates considerable heat energy. This study adds to the body of literature on detention pond performance, and raises concerns about the extensive use of stormwater ponds in watersheds where thermal stress is a concern. EPA SWMM is a widely used urban hydrologic, hydraulic and water quality model, though its application can be limited due to its deterministic nature, high dimensional parameter space, and the resulting implications for modelling uncertainty. In this work, I applied a global sensitivity analysis (SA) and evolutionary strategies (ES) calibration to SWMM to produce model predictions that account for parameter uncertainty in a headwater tributary case study in South Burlington, VT, USA. Parameter sensitivity was found to differ based on model structure, and the ES approach was generally successful at calibrating selected parameters, although less so as the number of concurrently varying parameters increased. A watershed water quality analysis using the calibrated model suggested that for different events in the record, the stream channel was alternately a source and a sink for sediment and nutrients, based on the predicted washoff loads and the measured loads from the stream sampling stations. These results add to the previous work on SWMM SA, auto-calibration, and parameter uncertainty assessment. Lastly, given the extent of eutrophication impairment in the U.S., I compared TN and TP data collected in these original works with national and regional datasets. TN concentrations sampled in this work were generally commensurate with values reported elsewhere, however TP data were not. Drainage area attributes and an event based rainfall runoff analysis of the study catchments provided circumstantial support for the idea that runoff from lawns is driving the high TP loads in Englesby Brook. The role of pet wastes is considered as a potentially fruitful area for further research.
160

Evaluating Stormwater Pollutant Removal Mechanisms by Bioretention in the Context of Climate Change

Cording, Amanda 01 January 2016 (has links)
Stormwater runoff is one of the leading causes of water quality impairment in the U.S. Bioretention systems are ecologically engineered to treat stormwater pollution and offer exciting opportunities to provide local climate change resiliency by reducing peak runoff rates, and retaining/detaining storm volumes, yet implementation is outpacing our understanding of the underlying physical, biological, and chemical mechanisms involved in pollutant removal. Further, we do not know how performance will be affected by increases in precipitation, which are projected to occur in the northeastern U.S. as a result of climate change, or if these systems could act as a source or sink for greenhouse gas emissions. This research examines the design, construction, and development of monitoring methods for bioretention research, using the University of Vermont (UVM) Bioretention Laboratory as a case study. In addition, this research evaluates mobilization patterns and pollutant loads from road surfaces during the "first flush" of runoff, or the earlier part of a storm event. Finally, this research analyzes the comparative pollutant removal performance of bioretention systems on a treatment by treatment basis. At the UVM Bioretention Laboratory, eight lined bioretention cells were constructed with monitoring infrastructure installed at the entrance and at the subterranean effluent. A conventional, sand and compost based, bioretention soil media was compared to a proprietary media engineered to remove phosphorus, called Sorbtive Media™, under simulated increases in precipitation. Two drought tolerant vegetation mixes, native to the northeast, were compared for sediment and nutrient retention. Each treatment was sampled for soil gas emissions to determine if it was a source or a sink. The monitoring infrastructure designs used in this research allowed for the effective characterization of pollutant mass loads entering and exiting bioretention. Cumulative mass loads from stormwater were found to be highest for total suspended solids, followed by total Kjeldahl nitrogen, nitrate, non-labile phosphorus and soluble reactive phosphorus, in descending order by mass. Total suspended solids, total Kjeldahl nitrogen, and non-labile phosphorus mass were well retained by all bioretention treatments. However, the compost amendment in the conventional soil media was found to release labile nitrogen and phosphorus, far surpassing the mass loads in stormwater. When compared with conventional media, Sorbtive Media™ was highly effective at removing labile phosphorus and was also found to enhance nitrate removal. Systems containing deep-rooted vegetation (Panicum virgatum) were found to be particularly effective at retaining both labile and non-labile constituents. Overall, none of the bioretention treatments were found to be a significant source of N2O and were small sinks for CH4 in most treatments.

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