<p>Measurements of radon (&sup2 / &sup2 / &sup2 / Rn) concentration in soil gas are routinely used to locate geological fault zones. This study was undertaken to investigate the systematic effects that influence radon soil-gas measurements, in preparation for the first such fault zone measurements in South Africa.</p>

Radon has been identified as an important factor that could result in a health hazard by studies all around the world. The health risks can be minimised by preventive measures where radon is highly concentrated as in some mines and homes. Measuring and modelling the radon concentrations in the mine dump soil, can help to deduce the radon flux to identify the problem areas for rehabilitation especially in the cases of gold and uranium mine tailings. Rehabilitation in those cases usually consists of a multilayer cover of solids like crushed rock or clay. A passive method incorporating electret technology was used in this study to determine the radon emanation coefficient of the soil. This investigation also describes the modelling of a depth profile with respect to the radon activity concentration to understand from how deep radon might be migrating, as well as the effect of different diffusion lengths.

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A thesis submitted to the Faculty of Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy February 2013 / A thorough understanding of the optical properties of aerosols, their spatial and temporal distribution and their radiative effects in the atmosphere, is needed for the better assessment of the impacts of aerosols on regional climate systems. Monitoring of aerosol parameters and solar radiation fluxes has been conducted in southern Africa by the AERONET programme since the middle of the last decade. These valuable data, combined with model estimates products, plus the intensive field experiments such as SAFARI 2000, provided key information, contributing towards a better overall understanding of the main characteristics of tropospheric aerosols over southern Africa and how these aerosols impact the direct aerosol forcing in the region. Two long-term AERONET sites, at Mongu in Zambia and Skukuza in South Africa, formed the core sources of data in this study. Secondary sites in Saudi Arabia (Solar Village) and United Arad Emirates (Hamin and Dhadnah) were used for comparison purposes. Aerosol optical properties and the direct aerosol radiative forcing over southern Africa both change significantly from one season to another, following the strong seasonal cycle of aerosol optical thickness (AOT). Consequently, the evaluation of aerosol forcing using static values throughout the year is not suitable for describing the aerosol climate effects in this region. Results show that the seasonal variations of aerosol optical thicknesses at 500 nm over southern Africa can be defined into three periods:  December to May with relatively clean atmospheric conditions, with monthly averages AOT values at 500 nm between 0.1 to 0.2, mainly associated with air masses from which aerosols have been washed during the wet season, and minimal regional biomass burning;  followed by a transition period towards high AOT values, from June to August, with a moderately turbid atmosphere (0.2 – 0.3);  September to November, with high levels of AOT (0.3 – 0.5) –mainly associated with biomass burning. Within this region a reversal gradient of AOT can be observed along the annual timeline; the north has higher magnitudes than the south, i.e. a north–south gradient, during the biomass-burning season and the opposite applies in the non-biomass burning season, i.e. a south–north gradient. From the currently available aerosol data, no long-term discernible trends are observable in aerosol loadings over this region. Direct aerosol radiative forcing evaluations, in southern Africa, need to take into account the differences between both the non-biomass burning and the biomass burning seasons. Direct aerosol forcing magnitudes during the biomass burning period are almost double those of the non-biomass burning at BOA and TOA. The impact of biomass burning on the direct aerosol forcing is not limited to the bottom of atmosphere (BOA), but also influences the forcing at top of atmosphere (TOA). Direct aerosol radiative forcing values for all of southern Africa are estimated at -33 W m-2 for BOA and -6 W m-2 for TOA. However, seasonal values may differ considerably from these levels. Monthly averages of direct aerosol radiative forcing at BOA are frequently less than -30 W m-2 from December to May (non-biomass burning period) with a slightly south-north gradient. From July to October, a strong north-south gradient of direct aerosol radiative forcing is observed and forcing magnitudes are frequently recorded at -50 W m-2 (and, on occasion well above that level) during September, i.e. at the peak of biomass burning. June and November are regarded as transitional months when levels move towards the higher or and lower values of forcing respectively. At TOA monthly averages of direct aerosol radiative forcing from December to May are frequently less than -9 W m-2 and, during biomass burning, direct aerosol radiative forcing values almost double. From the seasonal perspective, it is also possible to depict the reversal gradient behaviour at TOA. This study has contributed to improving the understanding and knowledge about of the direct aerosol radiative effects in this region - necessary step towards addressing the indirect and semi-direct aerosol effects. This study also emphasises the need for obtaining further data for defining the aerosol optical characterisations by regions or sub regions as demonstrated by the identifiable overall differences in the aerosol optical properties between the southern Africa and Middle Eastern regions. This process will require improving the quantity and quality of aerosol measurements at regional scales.

The green iguana (Iguana iguana) is an herbivorous lizard native to South America and is invasive in south Florida. The severe weather in January 2010 negatively impacted many species and significantly reduced the green iguana population, specifically adult females and juveniles of both sexes. Fifteen adult iguanas from two locations in Palm Beach County were tagged and had blood drawn for blood chemistry and HPLC steroid hormone analysis. Individuals were tracked for home range/territory analysis and behavioral observations. Blood chemistry values of cold-stunned individuals showed abnormal values similar to those reported in cold-stunned sea turtles. Territoriality and breeding behaviors, including nesting and head-bob displays, decreased or ceased during the following months. Steroid hormone concentrations were detected by HPLC and were not consistent with results from RIA studies in the literature. / by Ashley Campbell. / Thesis (M.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

by Kwok Shu Cheung, Eric. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1990. / Bibliography: leaves 89-106. / Acknowledgement --- p.i / Abstract --- p.ii / Introduction / Chapter A. --- Objective --- p.1 / Chapter B. --- Literature Review / Chapter 1. --- Electroplating industry in Hong Kong and its impact on the environment --- p.7 / Chapter 2. --- Physical and chemical methods for removing heavy metals from electroplating effluent --- p.11 / Chapter 3. --- Removal of heavy metals by conventional activated sludge process --- p.16 / Chapter 4. --- Acclimation of wastewater bacteria to heavy metals --- p.26 / Chapter 5. --- Biosorbent and its role in metal detoxification --- p.28 / Materials and Methods / Chapter A. --- Isolation and selection of nickel-resistant bacteria --- p.32 / Chapter B. --- Culture medium and solution --- p.33 / Chapter C. --- Growth of organism --- p.33 / Chapter D. --- Immobilization of bacterial cells --- p.36 / Chapter E. --- Effect of growth conditions on nickel removal capacity of immobilized Enterobacter sp. cells --- p.37 / Chapter F. --- Effect of bioreactor operational conditions on the Ni2+ removal capacity of immobilized bacterial cells --- p.38 / Chapter G. --- Optimization of nickel removal efficiency of bioreactor --- p.39 / Chapter H. --- Determination of Ni2+ adsorption isotherm of immobilized cells of Enterobacter sp. --- p.39 / Chapter I. --- Recovery of nickel from the bioreactor --- p.40 / Chapter J. --- Activity of the regenerated bioreactor --- p.41 / Chapter K. --- Removal of Ni2+ from synthetic effluent by bioreactor --- p.41 / Chapter L. --- Removal of Ni2+ from electroplating effluent by bioreactor. --- p.41 / Chapter M. --- Production of immobilized bacterial cells by replacement of D-glucose by molasses in the growth medium --- p.42 / Results / Chapter A. --- Isolation and selection of nickel resistant bacteria --- p.44 / Chapter B. --- Effect of growth conditions on nickel removal capacity of immobilized Enterobacter sp. cells / Chapter 1. --- Nutrient limitation --- p.44 / Chapter 2. --- D-glucose concentration --- p.45 / Chapter 3. --- Incubation temperature and incubation time --- p.45 / Chapter C. --- Heavy metal removal capacity of immobilized cells of Enterobacter sp. --- p.50 / Chapter D. --- Effect of bioreactor operational conditions on Ni2+ removal capacity of the immobilized bacterial cells --- p.50 / Chapter E. --- Optimization of nickel removal efficiency of bioreactor --- p.55 / Chapter F. --- Determination of Ni2+ adsorption isotherm of immobilized cells of Enterobacter --- p.57 / Chapter G. --- Recovery of nickel from the bioreactor and activity of regenerated bioreactor against a fresh nickel flow --- p.61 / Chapter H. --- Removal of Ni2+ from synthetic effluent by bioreactor --- p.61 / Chapter I. --- Removal of Ni2+ from electroplating effluent by bioreactor. --- p.64 / Chapter J. --- Production of immobilized bacterial cells by replacement of D-glucose by molasses in the growth medium --- p.68 / Discussions / Chapter A. --- Effect of growth conditions on nickel removal capacity of immobilized Enterobacter sp. cells --- p.70 / Chapter B. --- Heavy metal removal capacity of immobilized cells of Enterobacter sp. --- p.73 / Chapter C. --- Effect of bioreactor operational conditions on Ni2+ removal capacity of the immobilized bacterial cells --- p.74 / Chapter D. --- Optimization of nickel removal efficiency of bioreactor --- p.74 / Chapter E. --- Determination of Ni2+ adsorption isotherm of immobilized cells of Enterobacter sp. --- p.76 / Chapter F. --- Recovery of nickel from the bioreactor and activity of the regenerated bioreactor against a fresh nickel flow --- p.77 / Chapter G. --- Removal of Ni2+ from synthetic effluent by bioreactor --- p.78 / Chapter H. --- Removal of Ni2+ from electroplating effluent by bioreactor --- p.79 / Chapter I. --- Production of immobilized bacterial cells by replacement of D-glucose by molasses in the growth medium --- p.82 / Chapter J. --- Further considerations of applicability of immobilized Enterobacter sp. cells to treatment of electroplating effluent --- p.83 / Conclusions --- p.86 / References --- p.89

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This document is submitted in partial ful" lment for the degree: Master of Architecture [Professional] at the University of the Witwatersrand, Johannesburg, South Africa, in the year 2014. / “" at environment and those structures invest the vast di# erences of nature with meaning intelligible to, indeed imagined by, a mankind and they involve in the end all those complex relationships of human buildings with each other that shape within nature a man-made topography.” (Scully 1991: 1) Humankind has forever been placed outside the realm of nature, peering in as a spectator through a frame. ! at which is organic is ‘natural’ and that which we create is ‘man- made’. A beaver’s nest would not exist if the beaver had not built it, yet it is ‘natural’. If humans are of earth then surely that which we build is ‘natural’ as well? Let us translate the ‘man-made’ back into the natural world. Lake Malawi makes up one-third of its country. Local Malawians are dependent on this resource for livelihood, food, water and sanitation but over" shing threatens it. Cichlid " sh native to the lake are a rapidly evolving species, they are also a rapidly depleting food source. ! e lake with its local " shing villages is nature with us in it. I propose an underwater observatory on the shoreline of the lake, to address a species and a food source. Local Malawians inhabit the shoreline within a nature that has been adapted to meet the needs of human activity. Fishermen prepare their nets at sunset, go out at night with # ickering para$ n lamps, and return at sunrise with a diminishing catch of Chambo while women make their way to the water’s edge to wash and collect water. ! e chosen site is situated in Cape Maclear at the entrance to Lake Malawi National Park which is protected aquatic sanctuary. An established tourist industry supports the local community of Chembe village. ! e observatory is a threshold to the park and a liminal boundary between land and water, in and out, above and below. ! e programme is categorized within Science and Community. Communal facilities address alternative food sources, sanitation and education while science facilities document and record the rapid evolution of Cichlids. If architecture can be viewed as a hybrid, a construct of both human culture and nature, then let an amphibious structure rest upon the water’s edge, partially submerged and partially elevated over water and land. Acting as a bathometer, climatic changes mark its surface as it modi" es nature while nature modi" es it. Designed to adapt to # uctuating water levels, the facility evolves as rapidly as its native Cichlid " sh. By reframing the mindset of locals and visitors, we become part of an evolving ecosystem and may begin to truly acknowledge the part we play in it. We attempt to preserve a species and a livelihood, yet preservation may be viewed as the pursuit of stagnation. Our livelihoods, our food and our buildings are of this earth. Like nature, they must continuously adapt, modify and evolve.

Seasonal trends in water table level and soil moisture for four plant community types within an irrigated eastern Oregon riparian zone were described. Aboveground biomass, species composition, litter, percent bareground and percent basal cover of key plant species and life forms were measured. The relationship between water table levels and soil moisture content were analyzed using simple linear regression. Transition zones between plant community types based on soil moisture and/or depth to water table during the growing season were determined. The soil moisture-water table relationship can be used to predict changes in plant community composition induced by a permanent depth to water table change. Irrigation impact on meadow water table levels and stream temperature were determined. Water table levels responded to irrigation manipulations within days. The permanent cessation of irrigation would shrink the riparian meadows contained within this study from widths in excess of 300 m to less than 60 m. Continuous stream temperature data were collected on a stream running through adjacent non-irrigated and irrigated meadows. Daily maximum stream temperatures in the segment contained within the irrigated meadow were 1.0�� to 3.0�� C cooler than the reach contained within the non-irrigated meadow. Management impact on plant community attributes, forage production and forage quality were assessed under three pasture management alternatives. Comparison of stubble height, litter, forage production, forage quality, species composition, percent bareground and percent basal cover of key plant species and life forms indicated all three management alternatives are sustainable from both a plant community and a livestock production perspective. / Graduation date: 1996