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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.
41

The role of disturbance in the ecology of biofilms in the River Murray, South Australia / by Adrienne Burns.

Burns, Adrienne, 1971- January 1997 (has links)
Copy of author's previously published article inserted. / Bibliography: leaves 198-217. / 249 leaves : ill., maps ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis explores the impact of sustained disturbances on the ecology of algal dominated biofilms in the Lower River Murray, South Australia. It focuses on the physical effects of regulation through changes to the light environment and water level regime, and the local effects of grazing. The nutritional signficance of biofilms for the abundant populations of prawns and shrimps in the Lower Murray is also examined. / Thesis (Ph.D.)--University of Adelaide, Dept. of Zoology, 1997?
42

An experimental approach to golden perch (Macquaria ambigua) fry-zooplankton interactions in fry rearing ponds, south-eastern Australia / Phillip T. Arumugam

Arumugam, Phillip T. January 1986 (has links)
Bibliography: leaves 145-168 / 168 leaves : ill ; 31 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, 1986
43

Regional scale modelling of the lower River Murray wetlands: a model for the assessment of nutrient retention of floodplain wetlands pre- and post-management.

Bjornsson, Kjartan Tumi January 2008 (has links)
Most of the lower River Murray and its floodplain wetlands are impacted upon by degradation caused by river regulation. Increasingly the restoration of these ecosystems and the river water quality has become a high priority for federal and state governments and associated departments and agencies. Public concern is adding to the pressures on these departments and agencies to restore these ecosystems and to sustainably maintain the river water quality. The long term monitoring of floodplain wetlands has been limited, compounding the difficulties faced by managers and decision makers on assessing the potential outcome of restoration options. The role of this project in the broad scheme of restoration/rehabilitation is to contribute to the construction of a model capable of increasing managers and decision makers understanding, and build consensus of potential outcomes of management option. This model was to use available data. The developed model, based on WETMOD developed by Cetin (2001), simulates wetland internal nutrient processes, phytoplankton, zooplankton and macrophyte biomass as well as the interaction (nutrient and phytoplankton exchange) between wetlands and the river. The model further simulates the potential impact management options have on the wetlands, and their nutrient retention capacity, and therefore their impact on the river nutrient load. Due to the limitation of data, wetlands were considered in categories for which data was available. Of these two had sufficient data to develop, calibrate and validate the model. Management scenarios for these two wetlands were developed. These scenarios included, the impact of returning a degraded wetland in a turbid state to a rehabilitated clear state, and the impact the removal of nutrient from irrigation drainage inflows has on wetland nutrient retention, and consequent input to the river. Scenarios of the cumulative impact of the management of multiple wetlands were developed based on using these two wetlands, for which adequate data was available, as “exemplar” wetlands, i.e. data from these wetlands were substituted for other similar wetlands (those identified as belonging to the same category). The model scenarios of these multiple wetlands provide some insight into the potential response management may have on individual wetlands, the cumulative impact on river nutrient load and how wetland morphology may relate to management considerations. The model is restricted by data availability and consequently the outputs. Further, some limitations identified during the development of the model need to be addressed before it can be applied for management purposes. However, the model and methods provide a guide by which monitoring efforts can assist in developing future modelling assessments and gain a greater insight not only at the monitoring site but also on a landscape scale. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1320131 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2008
44

The valuation of South Australian wetlands and their water filtering function : a cost benefit analysis.

Schmidt, Carmel Elizabeth January 2007 (has links)
Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / "The Lower Murray dairy swamps were once part of a series of freshwater wetlands stretching along the Murray to the Cooring. Of the original 5700 hectares of wetlands only 500 hectares remain today. While the dairy industry that has developed on the swamp has considerable commercial value, it has destroyed the natural water filtration function that the wetlands provided. The industry also causes high levels of dairly effluent to enter the River Murray, contributing to blue-green algae outbreaks and associated economic losses for the local tourism industry. This thesis provides valuable cost-benefit results on a set of three mutually exclusive land use and management options for dealing with the joint problems of water filtration and blue-green algae. The most important options examined involve the return of this area to wetlands for water filtration rather continuing to use it for dairy farming." --p. ix. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1284108 / Thesis (Ph.D.) -- University of Adelaide, School of Economics, 2007
45

The valuation of South Australian wetlands and their water filtering function : a cost benefit analysis.

Schmidt, Carmel Elizabeth January 2007 (has links)
Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / "The Lower Murray dairy swamps were once part of a series of freshwater wetlands stretching along the Murray to the Cooring. Of the original 5700 hectares of wetlands only 500 hectares remain today. While the dairy industry that has developed on the swamp has considerable commercial value, it has destroyed the natural water filtration function that the wetlands provided. The industry also causes high levels of dairly effluent to enter the River Murray, contributing to blue-green algae outbreaks and associated economic losses for the local tourism industry. This thesis provides valuable cost-benefit results on a set of three mutually exclusive land use and management options for dealing with the joint problems of water filtration and blue-green algae. The most important options examined involve the return of this area to wetlands for water filtration rather continuing to use it for dairy farming." --p. ix. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1284108 / Thesis (Ph.D.) -- University of Adelaide, School of Economics, 2007
46

Is Dr. Andrew Murray a mystic?

De Villiers, Theo C. January 1919 (has links)
Thesis (MA (Theology))--University of Stellenbosch, 1919. / 48 leaves printed single pages, hand written on exercise book. Includes bibliography. Digitized at 300 dpi grayscale to pdf using an HPScanjet 8250 Scanner. / Please refer to full text for abstract. No Afrikaans abstract available.
47

Electrical conductivity imaging of aquifers connected to watercourses : a thesis focused on the Murray Darling Basin, Australia.

Allen, David Andrew. January 2007 (has links)
Electrical imaging of groundwater that interacts with surface watercourses provides detail on the extent of intervention needed to accurately manage both resources. It is particularly important where one resource is saline or otherwise polluted, where spatial quantification of the interacting resources is critical to water use planning and where losses from surface waterways need to be minimized in order to transport water long distances. Geo-electric arrays or transient electromagnetic devices can be towed along watercourses to image electrical conductivity (EC) at multiple depths within and beneath those watercourses. It has been found that in such environments, EC is typically related primarily to groundwater salinity and secondarily to clay content. Submerged geo-electric arrays can detect detailed canal-bottom variations if correctly designed. Floating arrays pass obstacles easily and are good for surveying constricted rivers and canals. Transient electromagnetic devices detect saline features clearly but have inferior ability to detect fine changes just below beds of watercourses. All require that water depth be measured by sonar or pressure sensors for successful elimination of effects of the water layer on the data. The meandering paths of rivers and canals, combined with the sheer volume of data typically acquired in waterborne surveys, results in a geo-referencing dilemma that cannot be accommodated using either 2D imaging or 3D voxel imaging. Because of this, software was developed by the author which allows users to view vertical section images wrapped along meandering paths in 3D space so that they resemble ribbons. Geo-electric arrays suitable for simultaneous imaging of both shallow and deep strata need exponentially spread receiver electrodes and elongated transmitter electrodes. In order to design and facilitate such arrays, signed monopole notation for arrays with iv segmented elongated electrodes was developed. The new notation greatly simplified generalized geo-electric array equations and led to processing efficiency. It was used in the development of new array design software and automated inversion software including a new technique for stable inversion of datasets including data with values below noise level. The Allen Exponential Bipole (AXB) array configuration was defined as a collinear arrangement of 2 elongated transmitter electrodes followed by receiver electrodes spaced exponentially from the end of the second transmitter electrode. A method for constructing such geo-electric arrays for use in rivers and canals was developed and the resulting equipment was refined during the creation of an extensive set of EC imaging case studies distributed across canals and rivers of the Australian Murray- Darling Basin. Man made and natural variations in aquifers connected to those canals and rivers have been clearly and precisely identified in more than 1000 kilometres of EC imagery.
48

Bayesian artificial neural networks in water resources engineering.

Kingston, Greer Bethany January 2006 (has links)
A new Bayesian framework for training and selecting the complexity of artificial neural networks (ANNs) is developed in this thesis, based on Markov chain Monte Carlo (MCMC) techniques. The primary motivation of the research presented is the incorporation of uncertainty into ANNs used for water resources modelling, with emphasis placed on obtaining accurate results, while maintaining simplicity of implementation, which is considered to be of utmost importance for adoption of the framework by practitioners in this field. By applying the Bayesian framework to a number of synthetic and real-world case studies and by comparison with a state-of-the-art ANN development approach, it is shown throughout this thesis how the Bayesian approach can be used to address the three most significant issues facing the wider acceptance of ANNs in this field; namely generalisability, interpretability and uncertainty. The state-of-the-art approach is devised through reviewing and, where necessary, improving current best practice deterministic ANN development methods, leading to the recommended use of the global SCE-UA optimisation algorithm, which has not been used before for ANN training, and the development of a modified connection weight approach for extracting knowledge from trained ANNs. The real-world case studies used in this research, which involve salinity forecasting in the River Murray at Murray Bridge, South Australia, and the forecasting of cyanobacteria (Anabaena spp.) in the River Murray at Morgan, South Australia, are used to demonstrate the practical value of the Bayesian framework, particularly when extrapolation is required and when the available data are of poor quality. These issues lead to poor model performance when deterministic ANN development methods are applied, yet as the generated predictions are deterministic, there is no direct way of assessing their quality. Application of the proposed Bayesian framework leads to better average performance of the ANN models developed, since a minimal ANN structure is selected and a more generalised input-output mapping is obtained. More importantly, prediction limits are provided which quantify the uncertainty in the predictions and enable management and design decisions to be made based on a known level of confidence. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1235735 / Thesis (Ph.D.) --, University of Adelaide, School of Civil and Environmental Engineering, 2006
49

Carp (Cyprinus carpio L.) spawning dynamics and early growth in the lower River Murray, South Australia / Benjamin B. Smith.

Smith, Benjamin Baxter January 2004 (has links)
"August 2004" / Includes bibliographical references. / xi, 108 p. : ill., maps, plates ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / "This thesis extends and summarises Australian data on carp (Cyprinus carpio L.) reproductive biology and early growth. Specifically, it (1) validates the aging of larval and early-juveniles via daily otolith increment counts, (2) provides regression equations to account for shrinkage that occurs upon preservation of young-of-the-year (YOY) carp in 70 and 95% ethanol, (3-4) investigates the timing, frequency and duration of spawning via gonad staging and via a combination of gonad staging and YOY sampling, and (5) investigates relationships between YOY recruitment and nine hydro-climatic parameters, and examines spatial and temporal variation in YOY growth." / Thesis (Ph.D.)--University of Adelaide, School of Earth and Environmental Sciences, Discipline of Environmental Biology, 2004
50

An angle of vision : southern cosmopolitanism 1935-1974 / Southern cosmopolitanism 1935-1974

Mass, Noah 23 April 2013 (has links)
As they took stock of the ways that the Great Migration and America’s post-war global role were changing the South, Richard Wright, Carson McCullers, Ralph Ellison, and Albert Murray crafted narratives that articulated a particular perspective on the South. These writers dreamed of putting the regionally distinctive characteristics that they found valuable in the South into conversation with a sense of expansiveness and possibility, one that they associated with a migratory and increasingly globally-connected nation. In this project, I examine these southern cosmopolitan negotiations in Wright, McCullers, Ellison, and Murray’s southern narratives, and I argue that these writers are crucial to our understanding of the post-migration South in the twentieth and twenty-first centuries. / text

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