Thesis (Ph. D.)--University of Texas at Austin, 2005. / Vita. Includes bibliographical references.

Thesis (M.Sc.)--York University, 2007. Graduate Programme in Geography. / Typescript. Includes bibliographical references (leaves 157-163). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR38844

The City of Regina Fleet Street landfill, north-east of Regina, Saskatchewan, is approaching its maximum capacity after a 47-year operating life and plans are now being made for its closure. As part of closure planning work, four test plots encompassing two different cover designs (a capillary break cover and a store-and-release cover) were constructed on the landfill in the summer of 2004. One cover of each design was constructed on both the north facing and the south facing slopes.<p> The overall objective of this thesis is to evaluate the preliminary performance of the four test plots on the City of Regina landfill with regards to net percolation, gas flux, water balance and vegetation. To meet this overall objective three specific objectives were developed as follows:<p> Evaluate the performance and integrity of the monitoring scheme. <p> Characterize the properties of the soil covers on the four test plots. <p> Develop a preliminary water balance using the monitoring field data. <p> A field instrumentation program was carried out which included detailed monitoring of gas composition, volumetric water content, matric suction and temperature within the cover profile as well as measurements of interflow, runoff and site-specific meteorology. Generally, the instrumentation performed well with the exception of the tipping bucket which did not accurately measure precipitation.<p> Evaluation of the covers revealed that the slope aspect exerts greater influence over the water balance than that exerted by cover design itself. The south test plots were drier than the north, experienced more net radiation, and generally had more abundant vegetation. A water balance was conducted for each test plot at the upper, mid and lower slope. It is clear that a capillary break was not maintained on the north slope for the entire monitoring period and the percolation from the store-and-release cover was less than that of the capillary break cover. The south test plots were very dry and net percolation was nearly the same for both test plots. Therefore, it is believed that the store-and-release covers are performing better than the capillary break covers.

The City of Regina Fleet Street landfill, north-east of Regina, Saskatchewan, is approaching its maximum capacity after a 47-year operating life and plans are now being made for its closure. As part of closure planning work, four test plots encompassing two different cover designs (a capillary break cover and a store-and-release cover) were constructed on the landfill in the summer of 2004. One cover of each design was constructed on both the north facing and the south facing slopes.<p> The overall objective of this thesis is to evaluate the preliminary performance of the four test plots on the City of Regina landfill with regards to net percolation, gas flux, water balance and vegetation. To meet this overall objective three specific objectives were developed as follows:<p> Evaluate the performance and integrity of the monitoring scheme. <p> Characterize the properties of the soil covers on the four test plots. <p> Develop a preliminary water balance using the monitoring field data. <p> A field instrumentation program was carried out which included detailed monitoring of gas composition, volumetric water content, matric suction and temperature within the cover profile as well as measurements of interflow, runoff and site-specific meteorology. Generally, the instrumentation performed well with the exception of the tipping bucket which did not accurately measure precipitation.<p> Evaluation of the covers revealed that the slope aspect exerts greater influence over the water balance than that exerted by cover design itself. The south test plots were drier than the north, experienced more net radiation, and generally had more abundant vegetation. A water balance was conducted for each test plot at the upper, mid and lower slope. It is clear that a capillary break was not maintained on the north slope for the entire monitoring period and the percolation from the store-and-release cover was less than that of the capillary break cover. The south test plots were very dry and net percolation was nearly the same for both test plots. Therefore, it is believed that the store-and-release covers are performing better than the capillary break covers.

An evaluation of the global water storage contribution to the Chandler wobble has never been undertaken because: (1) the hydrological data necessary for the reconstruction of an extended monthly time series have not been available; and (2) the water storage contribution has traditionally been regarded as relatively unimportant because of its minor role in the excitation of the annual wobble. However, a crude approximation of the global water storage series is possible using worldwide records of monthly precipitation and temperature, accumulating precipitation at individual locations whenever temperatures are at 0° Celsius or below. Comparison of this modeled series with a previous estimate of the annual component of the global water balance, and with the observed monthly polar motion series, indicates good agreement with the former, and a significant correlation with the latter near the Chandler frequency. / text

Thesis (Ph.D.)--Pennsylvania State University, 2008. / Mode of access: World Wide Web.

Thesis (M.S.)--University of North Texas, Dec., 2008. / Title from title page display. Includes bibliographical references.

Thesis (Ph.D.)--The Chinese University of Hong Kong, 2005. / Advisers: Chen Yongqin, Lam Kin-che. Includes bibliographical references (p. 174-190)

Thesis (M.Sc.)(Entomology)--University of Pretoria, 2006. / Includes summary. Includes bibliographical references. Available on the Internet via the World Wide Web.

Eskom produces approximately 90% of the electricity used in South Africa of which approximately 90.8% is from fossil fuel power plants. The process of electricity generation requires a significant quantity of raw water; therefore, Eskom is considered a strategic water user in South Africa. Water management is a growing focus area due to the increase in water usage and requires continuous improvement. Water management has been identified as an area lagging behind on the advanced analytics initiatives in Eskom. Excel based tools were used for the development of water balance models and water performance calculations in Eskom. This was attributed to the user-friendly functionality and availability to all users. However, the Excel tool posed challenges in allowing for standardisation and validation of calculations, tracking of model changes, continuous trending and storage of data as well as structured graphical user interfaces for screens and dashboard developments. There was therefore a need to develop a methodology on how to structure a water balance model for coal-fired power plants with standard calculation templates that allowed for customisation by each power plant within Eskom. It was required that the water balance model be implemented on a performance and monitoring tool allowing for comparison of power plant targets to actual online data in real time, enhancing the monitoring capabilities. It should have the ability to generate real time water performance data creating an opportunity for improved water management across the generation fleet. The approach adopted in this dissertation was to learn from existing Eskom Excel water balance tools and develop a standard mathematical model in the form of EtaPRO calculation templates. These templates are be structured such that they function as process components to develop water balances at power plants. The mathematical verification of the Excel calculations were to be conducted using Mathcad. The access to real time data, performance monitoring capabilities and availability at all Eskom Power plants, led to the selection of EtaPRO as the modelling platform. The research conducted led to the development of a methodology for setting up a water balance model for a wet-cooled coal-fired power plant. Calculation templates developed into EtaPRO were validated against the Mathcad mathematical model. The results included a well-documented mathematical model of a water balance in Mathcad and the development of 19 calculation templates that perform the function of standard process components. In addition to calculation templates, multiple Non Volatile (NV) records were created to allow the power plants to capture and track permanent data inputs. NV records also allow for creation of case studies, improving the process monitoring capabilities. A water balance model for a selected power plant was simulated in EtaPRO using the developed calculation templates and user defined formulae. Test screens and dashboards were created to illustrate how the calculation templates and water balance framework would be used to develop a typical water balance model and monitoring system. In conclusion, it is possible to develop process models within the EtaPRO software from well-defined mathematical models to address the performance monitoring concerns on water systems within Eskom.