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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.
101

Comparing salinity models in Whitewater Bay using remote sensing

Unknown Date (has links)
This study compared models that used remote sensing to assess salinity in Whitewater Bay. The quantitative techniques in this research allow for a less costly and quicker assessment of salinity values. Field observations and Landsat 5 TM imagery from 2003-2006 were separated into wet and dry seasons and temporally matched. Interpolation models of Inverse Distance Weighting and Kriging were compared to empirical regression models (Ordinary Least Squares and Geographically Weighted Regression - GWR) via their Root Mean Square Error. The results showed that salinity analysis is more accurate in the dry season compared with the wet season. Univariate and multivariate analysis of the Landsat bands revealed the best band combination for salinity analysis in this local area. GWR is the most conducive model for estimating salinity because field observations are not required for future predictions once the local formula is established with available satellite imagery. / by Donna Selch. / Thesis (M.A.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
102

Participatory monitoring and evaluation of marine water quality, a case study of Sappi Saiccor, Umkomaas.

McPherson, Mamosa Eileen. January 2002 (has links)
Previously, issues concerning the use and conservation of the natural resources were restricted to certain groups of individuals, normally those considered to be scientific experts. However with the emergence of sustainable development and the adoption of its principles therein, there has been increased community concern over environmental quality issues resulting in pressure for transparency in environmental decision-making processes. The result has been a dramatic expansion in the number of organisations at the local, national and global scales committed to environmental improvement. This in turn has let to dramatic changes in the role of the public in decisions relating to natural resource management. Participatory development is now acknowledged as critical in achieving sound environmental management. The initiation of community-based environmental decision-making has led to the formation of new and interesting partnerships. Environmentalists, communities, policy makers and business people have begun to work together in an attempt to find consensus concernIng environmental problems and related socio-economic inequalities. This has resulted in the development of new ways of integrating local and scientific knowledge systems. This thesis illustrates community-based environmental decision-making in the management of the use of the south coast of Durban. It outlines a partnership, through the formation of the Permit Advisory Panel (PAP), comprising industry (Sappi Saiccor), government, through its Department of Water Affairs and Forestry, environmental organisations, and the local people in the monitoring of the impacts of effluent produced by the industry and disposed of into the sea. The aim of this thesis is to develop an alternative methodology that will be acceptable to all stakeholders, for the collection and analysis of data in the monitoring of the Sappi Saiccor effluent. This was achieved through the following objectives: to develop a methodology for the collection and analysis of data, to assess the performance of the new pipeline in terms of reduced aesthetic impacts of the effluent, to assess the role of local knowledge in the monitoring process, and finally to assess the role of this study in the functioning of the PAP. This thesis attempts to integrate qualitative and quantitative methodologies. The subjective local data collected by the divers is analysed using statistical methods to assess the impacts of the effluent on marine water quality and the effect the new pipeline has had in reducing these impacts. Qualitative surveys such as questionnaires and interviews were administered to assess the role of local knowledge in the monitoring process and also to assess the role this study has had in the functioning of the PAP. The statistical analysis did not reveal any major improvement in underwater visibility since the pipeline was extended. There is a 6% and 4% improvement in the number of effluent days and visibility respectively. This however is due to some limitations inherent in the data collection process, and as a result the improvement brought about by the pipeline extension has been toned down. An effluent and visibility index is therefore recommended as an alternative method of data collection and analysis to reduce the level of inaccuracy. The role of local knowledge is perceived by many of the PAP members as vital in the monitoring process. This study was therefore thought of as an important step in validating this local knowledge such that it can be a reliable data source to be used in the monitoring process. It also played an important role in resolving the conflict between the PAP members. It is therefore recommended that the divers data should be continually used in the monitoring process, though the divers have to be more actively involved. The PAP is therefore tasked with liasing with the community members, especially the divers such that they can assume a more active and responsible role within the PAP. They should be involved in the development of the methods of data collection and analysis. / Thesis (M.A.)-University of Natal, Durban, 2002.
103

Monitoring of heavy metals in the Bottelary River using Typha capensis and Phragmites australis.

Ma, Ying January 2005 (has links)
The aim of this study was to use plants to determine the degree of heavy metal contamination in water and sediments in order to effectively monitor and provide possible recommendation to improve the water quality in the aquatic ecosystem of the Bottelary River.
104

Developing a service quality measurement instrument for archival institutions

Sibanda, Rosemary 11 1900 (has links)
The service sector of the global economy is undoubtedly growing and increasingly highlighting the criticality of service quality to enhanced profitability in most service organisations. The demand for accountability from different stakeholders, including clients, has also made service quality a highly debated, researched and most powerful competitive trend shaping marketing and business strategy. Developing reliable measurement instruments of service quality and strategies for the improvement of service quality invariably become the most important responsibilities for managers in many organisations. In the absence of conceptual clarity on service quality, divergent views on the dimensionality of service quality and the lack of a psychometrically valid service quality measure in archival institutions, this study set out to develop and subsequently validate a measurement instrument to assess service quality in an archival institutional setting. The two research questions investigated in this study were: (1) what are the dimensions for measuring service quality in archival institutions, and (2) how can the dimensions of service quality in archival institutions be measured effectively. The methodology for this study involved a two-phased qualitative and quantitative analysis addressing these two research questions. The study followed the standard psychometric procedure for developing constructs. This research has resulted in the important findings and relevant conclusions for both academics and practitioners interested in service quality in the archival environment. The service quality measurement instrument formulated is called ARCHIVqual and has three dimensions, namely (1) security of information (with 4 items), (2) integrity of information (with 3 items) and (3) usability of information (with 2 items). Besides measuring service quality in the archival environment, ARCHIVqual will also serve as a tool for conducting periodic surveys thereby identifying specific problematic areas in archival institutions. / Graduate School for Business Leadership / DBL
105

Design and Implementation of an Analog Video Signal Quality Measuring Software for Component Video / Design och implementering av utvärderingsmjukvara för signalkvalitet i analog komponentvideo

Ljungström, Carl January 2010 (has links)
An IP based set-top box (STB) is essentially a lightweight computer used to receive video over the Internet and convert it to analog or digital signals understood by the television. During this transformation from a digital image to an analog video signal many different types of distortions can occur. Some of these distortions will affect the image quality in a negative way. If these distortions could be measured they might be corrected and give the system a better image quality. This thesis is a continuation of two previous theses where a custom hardware for sampling analog component video signals was created. A software used to communicatewith the sampling hardware and perform several different measurementson the samples collected has been created in this thesis. The analog video signal quality measurement system has been compared to a similar commercial product and it was found that all except two measurement methods gave very good results. The remaining two measurement methods gave acceptable result. However the differences might be due to differences in implementation. The most important thing for the measurement system is to have consistency. If a system has consistency then any changes leading to worse videoquality can be found.
106

Hållbarhetsrapportering i Ryssland och Sverige : En komparativ studie av kvalitativa skillnader inom energibranschen

Arfanidis, Alexandros, Smith, Nikolai Derek January 2021 (has links)
Denna studie har undersökt skillnader mellan Ryssland och Sverige i relation till kvaliteten avhållbarhetsrapporter inom energibranschen. Studien bygger på en komparativ tvärkulturelldesign där flera fall med ett antal observationer jämförs mellan varandra och använder sig aven flermetodsforskning. Bland teorier har intressentteorin, legitimitetsteorin samt tidigareforskning används som hjälp för att analysera studiens empiri. Utifrån det empiriska materialetframkommer att de svenska bolagen har högre kvalitet när det gäller beskrivningar av produktensamt frågor som berör miljön och energi. Däremot har de ryska företagen högre kvalitet inomde sociala aspekterna av hållbarhetsredovisning. Inom resterande kategorier har både svenskaoch ryska företag presterat på samma nivå. / This study has examined differences between Russia and Sweden in relation to the quality ofsustainability reports in the energy industry. The study is based on a comparative cross-culturaldesign where several cases with a number of observations are compared with each other anduse a multi-method research. Among theories, the stakeholder theory, the legitimacy theory andprevious research have been used to help analyze the empirical data of the study. Based on theempirical material, it appears that the Swedish companies have a higher quality when it comesto descriptions of the product and issues concerning the environment and energy. On the otherhand, the Russian companies have higher quality in the social aspects of sustainabilityreporting. In the remaining categories, both Swedish and Russian companies have performedat the same level.
107

Augmenting Indiana's groundwater level monitoring network: optimal siting of additional wells to address spatial and categorical sampling gaps

Sperl, Benjamin J. 21 November 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Groundwater monitoring networks are subject to change by budgetary actions and stakeholder initiatives that result in wells being abandoned or added. A strategy for network design is presented that addresses the latter situation. It was developed in response to consensus in the state of Indiana that additional monitoring wells are needed to effectively characterize water availability in aquifer systems throughout the state. The strategic methodology has two primary objectives that guide decision making for new installations: (1) purposive sampling of a diversity of environmental variables having relevance to groundwater recharge, and (2) spatial optimization by means of maximizing geographic distances that separate monitoring wells. Design objectives are integrated in a discrete facility location model known as the p-median problem, and solved to optimality using a mathematical programming package.
108

Combining Multivariate Statistical Methods and Spatial Analysis to Characterize Water Quality Conditions in the White River Basin, Indiana, U.S.A.

Gamble, Andrew Stephan 25 February 2011 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / This research performs a comparative study of techniques for combining spatial data and multivariate statistical methods for characterizing water quality conditions in a river basin. The study has been performed on the White River basin in central Indiana, and uses sixteen physical and chemical water quality parameters collected from 44 different monitoring sites, along with various spatial data related to land use – land cover, soil characteristics, terrain characteristics, eco-regions, etc. Various parameters related to the spatial data were analyzed using ArcHydro tools and were included in the multivariate analysis methods for the purpose of creating classification equations that relate spatial and spatio-temporal attributes of the watershed to water quality data at monitoring stations. The study compares the use of various statistical estimates (mean, geometric mean, trimmed mean, and median) of monitored water quality variables to represent annual and seasonal water quality conditions. The relationship between these estimates and the spatial data is then modeled via linear and non-linear multivariate methods. The linear statistical multivariate method uses a combination of principal component analysis, cluster analysis, and discriminant analysis, whereas the non-linear multivariate method uses a combination of Kohonen Self-Organizing Maps, Cluster Analysis, and Support Vector Machines. The final models were tested with recent and independent data collected from stations in the Eagle Creek watershed, within the White River basin. In 6 out of 20 models the Support Vector Machine more accurately classified the Eagle Creek stations, and in 2 out of 20 models the Linear Discriminant Analysis model achieved better results. Neither the linear or non-linear models had an apparent advantage for the remaining 12 models. This research provides an insight into the variability and uncertainty in the interpretation of the various statistical estimates and statistical models, when water quality monitoring data is combined with spatial data for characterizing general spatial and spatio-temporal trends.
109

Influence of matrix effect of selected organochlorine pesticide residues in water from the Jukskei River catchment

Rimayi, Chengetayi Cornelius 11 1900 (has links)
M. Tech. (Biotechnology) Vaal University of Technology / One of the major problems encountered in qualitative and quantitative determination of residual pesticides by gas chromatography is the matrix effects. Matrix components have a considerable effect on the way analysis is conducted and the quality of results obtained, introducing problems such as inaccurate quantification, low analyte delectability and reporting of false positive or even false negative results. It was aimed to develop and validate a suitable method for counteracting the matrix effects so as to improve the detection and quantification of selected organochlorine pesticide residues from real water samples. The real water samples used were sampled from three points along the Jukskei River catchment area in Gauteng, South Africa for a period of 7 months from January to July 201 0 so as to create a representative sample. An automated solid phase extraction (SPE) method coupled to Gas ChromatographyMass Spectrometry (GC-MS) method for the analysis of 20 selected organochlorine pesticides was developed and validated for the purposes of studying the matrix effects. The analytical method showed a significant degree of validity when tested against parameters such as linearity, repeatability and sensitivity. Endosulphan beta, 4,4' Dichlorodiphenyldichloroethane, and Heptachlor-epoxide had the broadest linear calibration ranges of 1 ppm- 0.0156 ppm. Benzene hexachloride (BHC) delta and Lindane had the lowest statistical limits of detection of 0.018 ppm. Statistical hypothesis testing indicated that there was significant linearity in all selected organochlorine calibration curves. Four different reversed sorbent phases, including LC18, SC18- E and Strata-X (styrene divinyl benzene) were tested for organochlorine retention efficiency. The LC-18 200 mg cartridge proved to be the most robust and effective sorbent phase as it produced better recoveries varying from 90-130% for most analytes. A breakthrough volume of 100 ml for the LC-18 200 mg cartridge was determined using an optimum matrix load curve. It was then concluded that the method developed was suitable for further research towards the influence of the matrix on selective determination of the selected organochlorine pesticides. Four different calibration methods, namely matrix-free external standard, matrixmatched external standard, matrix-free internal standard and matrix-matched internal standard were applied to test the efficiency of computing recoveries. All calibration curves for the 20 organochlorine pesticides showed significant linearity > 0.99 when plotted on both Chemstation and Excel. The calibration methods were tested on three different matrices composed of a high sample matrix (synthetic matrix), a low sample matrix (real sample matrix) and a no sample matrix (ultrapure water). Statistical hypothesis testing led to the decision that there are significant differences between the mean recoveries of the three water sample matrices and also that the differences in the mean recoveries of the three sample matrices are independent of the both the two calibration techniques (internal standard and external standard) and calibration types (matrix-matched and matrix-free) applied. This led to the overall conclusion that the matrix effects have an overwhelming influence on the selective determination of the selected organochlorine pesticides.
110

Optimal water quality management in surface water systems and energy recovery in water distribution networks

Telci, Ilker Tonguc 24 October 2012 (has links)
Two of the most important environmental challenges in the 21st century are to protect the quality of fresh water resources and to utilize renewable energy sources to lower greenhouse gas emissions. This study contributes to the solution of the first challenge by providing methodologies for optimal design of real-time water quality monitoring systems and interpretation of data supplied by the monitoring system to identify potential pollution sources in river networks. In this study, the optimal river water quality monitoring network design aspect of the overall monitoring program is addressed by a novel methodology for the analysis of this problem. In this analysis, the locations of sampling sites are determined such that the contaminant detection time is minimized for the river network while achieving maximum reliability for the monitoring system performance. The data collected from these monitoring stations can be used to identify contamination source locations. This study suggests a methodology that utilizes a classification routine which associates the observations on a contaminant spill with one or more of the candidate spill locations in the river network. This approach consists of a training step followed by a sequential elimination of the candidate spill locations which lead to the identification of potential spill locations. In order to contribute the solution of the second environmental challenge, this study suggests utilizing available excess energy in water distribution systems by providing a methodology for optimal design of energy recovery systems. The energy recovery in water distribution systems is possible by using micro hydroelectric turbines to harvest available excess energy inevitably produced to satisfy consumer demands and to maintain adequate pressures. In this study, an optimization approach for the design of energy recovery systems in water distribution networks is proposed. This methodology is based on finding the best locations for micro hydroelectric plants in the network to recover the excess energy. Due to the unsteady nature of flow in water distribution networks, the proposed methodology also determines optimum operation schedules for the micro turbines.

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