• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 79
  • 10
  • 8
  • 8
  • 8
  • 8
  • 8
  • 8
  • 6
  • 3
  • 3
  • 2
  • Tagged with
  • 132
  • 132
  • 132
  • 44
  • 40
  • 40
  • 25
  • 23
  • 21
  • 19
  • 17
  • 15
  • 13
  • 12
  • 12
  • 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.
1

Development and evaluation of the mallard duck as a model to investigate the immunotoxicity of environmental chemicals

Fowles, Jefferson R. 29 October 1993 (has links)
Graduation date: 1994
2

The environmental impact of aeronautical activities : legal aspects

Savin, Sophie January 1992 (has links)
No description available.
3

A study of Ag-110m in aquatic and terrestrial ecosystems and the development of a radioecological model

Shang, Zhaorong., 商照榮. January 2001 (has links)
published_or_final_version / abstract / toc / Physics / Doctoral / Doctor of Philosophy
4

Formation and release of adsorbable organic halogens during kraft pulp bleaching

Hart, Peter W. 12 1900 (has links)
No description available.
5

Chemical pollution arising from heavy inorganic industries in Richards Bay - an assessment.

January 2004 (has links)
The industrial port of Richards Bay on the eastern seaboard of KwaZulu-Natal, South Africa has undergone rapid growth over the last 25 years. This industrial growth has inevitably led to an increase in the anthropogenic pollutant inputs in the area. However, the degree of this contamination has not previously been assessed not been accompanied by an awareness of its environmental impacts. This project serves to assess the current environmental situation of the area and provide background levels against which the environmental impacts of further growth in the area can be assessed. The main pollution point sources in the area were identified as a pulp and paper plant, a sulfuric acid/fertiliser plant and aluminium smelters. The chemical and physical processes involved within these industries were identified and discussed in detail. The common inorganic pollutants emitted by these industries were identifies as trace metals, sulfur dioxide, NOx gases and fluoride. It was these pollutants that therefore became the focus of this study. Reservoirs within Richards Bay that may become sinks for contamination were identified and water, sediment and soil samples were taken from these reservoirs. The samples were analysed for trace metal contamination, pH, alkalinity and fluoride levels. Analysis of the acidity and alkalinity of water, sediment and soils samples demonstrated that there is presently no long-term acidification of the environment in Richards Bay. The only samples that showed increased acidity were the soils taken from the roadside sites immediately outside the industries. This lack of overall acidification indicates that, at present, there are no detrimental effects of acidic emissions on the hydrosphere and geosphere. Only cursory investigations were conducted into the fluoride levels found in water samples. None of the samples analysed demonstrated detectable amounts of fluoride present. Comprehensive trace metal analyses were performed on the water, sediment and soil samples through the use of ICP-AES. Levels obtained were compared with levels from samples taken from relatively uncontaminated background sites. Trace metal analysis indicated contamination of the freshwater reservoirs when compared with the background, while the soils and saltwater reservoirs remain largely uncontaminated. However, the contaminated areas did not show levels greater than quality guideline concentrations. Further studies should be conducted with regards to the trace metal contamination of the biosphere and the bioavailability of the contaminants already present in the waters, sediments and soils. More detailed investigations should also be conducted into the levels of atmospheric pollutants and fluoride levels in all reservoirs. / Thesis (M.Sc.) - University of KwaZulu-Natal, Pietermaritzburg, 2004.
6

JAPANESE ENVIRONMENTAL POLLUTION: A CASE STUDY OF THE KANEMI RICE OIL DISEASE VICTIMS.

HAUSKNECHT, PHILLIP ARNE. January 1983 (has links)
All major pollution incidents in contemporary Japan have spawned victims' protest movements. This dissertation is a case study of one such movement which emerged in the late 1960s among thousands of persons poisoned by polychlorinated biphenyls (PCBs) that had accidentally leaked into their cooking oil. The study describes the evolution of victims' response to the disaster, beginning with the initial outbreak of symptoms, their efforts to uncover the cause of these symptoms and to receive appropriate medical treatment, and their organization of a movement to seek redress in the form of an apology from the manufacturer of the oil, reform by industry and government, and compensation. Victims utilized a variety of tactics before finally resorting to litigation in attempts to achieve their goals. Theirs was the largest pollution case ever tried in Japan. The final section of the study focuses on a major leader of the victims' movement, Kamino Ryuzo. A spokesman for the victims, Kamino, a retired miner and Christian convert, became a kind of anti-pollution ideologue. An account of his intellectual and religious odyssey and of the unique tactics forged by his family to cope with their predicament provides a perspective on victims' movements not found elsewhere. The study concludes that victims became their own advocates only after the government and industry failed to accept responsibility for pollution; that the victims went to court only reluctantly after all other avenues for redress were closed to them; and that, although they won their case, they felt it was a Pyrrhic victory, because they failed to attain all their goals, such as reform of industrial policy. Research is based on participation-observation, interviews, written materials produced by pollution victims and their supporters, and published newspaper accounts.
7

Biological Indices of Stream Pollution

Russell, James C. 08 1900 (has links)
A thorough biological survey and evaluation is a lengthy and expensive project. The number of technically trained persons required prevent its use by most public agencies. Since public health departments are the groups most frequently concerned with measuring the effects of pollution in streams, a need exists for a simplified method of sanitary survey. Recognizing this need, the Texas Health Department assigned the writer the problem of devising a method of survey which would require a field party of two and could be conducted entirely from a mobile field laboratory.
8

Group invariant solutions for contaminant transport in saturated soils under radial uniform water flow background

Potsane, Moshe Moses 06 August 2013 (has links)
A dissertation submitted to the Faculty of Science, University of the Witwatersrand, in ful llment of the requirements for the degree of Master of Science. March 27, 2013 / The transport of chemicals through soils to the groundwater or precipitation at the soils surfaces leads to degradation of the resources such as soil fertility, drinking water and so on. Serious consequences may be su ered in the long run. In this dissertation, we consider macroscopic deterministic models de- scribing contaminant transport in saturated soils under uniform radial water ow backgrounds. The arising convection-dispersion equation given in terms of the stream functions is analyzed using classical Lie point symmetries. A number of exotic Lie point symmetries are admitted. Group invariant solu- tions are classi ed according to the elements of the one-dimensional optimal systems. We analyze the group invariant solutions which satisfy some physical boundary conditions. The governing equation describing movements of contaminants under ra- dial water ow background may be given in conserved form. As such, the conserved form of the governing equation may be written as a system of rst order partial di erential equation referred to as an auxiliary system, by an in- troduction of the nonlocal variable. The resulting system of equations admits a number of (local) point symmetries which induce the nonlocal symmetries for the original governing equation. We construct classes of solutions using the admitted genuine nonlocal symmetries, which include the invariant solutions obtained via corresponding point symmetries of the governing equation.
9

Assessing the PM10 footprint of an iron and steel plant on ambient air quality : modelling PM10 emissions from the ArcelorMittal Vanderbijlpark Works iron and steel plant.

Jagathlal, Sham 03 March 2014 (has links)
Iron and steel plants in general are significant sources of PM10 pollution. Many studies have concluded that PM10 is harmful to human health and well being. ArcelorMittal Vanderbijlpark Works falls within the jurisdiction of the Vaal Triangle Airshed Priority Area (VTAPA) and has been given PM10 reduction targets in the Air Quality Management Plan. The aim of this study is to use dispersion modelling to determine the impact of the Vanderbijlpark Works steel plant on ambient PM10 and to assess the effectiveness of the reduction strategies with respect to PM10 The AERMOD dispersion model was chosen for the exercise because of its reliability when modelling near field dispersions on relatively flat terrain. Meteorological data was obtained from on-site stations. Emissions data was obtained from an already existing emissions inventory on site. The study modelled the PM10 baseline for 2010 and then modelled the predicted concentrations after implementation of the strategies as outlined in the VTAPA. The modeling scenarios were compared to the measured PM10 data from the fence line monitors. The following findings were made: Point sources were not significant contributors to PM10 emission. Modeling of area sources and other fugitive dust sources were found to be high and when compared to measured concentrations were found to be over predicted. It is concluded that the fugitive sources have been found to be the major source of PM10 emissions and that reduction of fugitives should feature prominently in emission reduction plans going forward. In addition, the fugitive emissions inventory needs to be refined to enhance the accuracy of the predictions.
10

Regulation of chemicals : product and process technology as a determinant of the compliance response.

Jaffe, Adam Benjamin January 1978 (has links)
Thesis. 1978. M.S.--Massachusetts Institute of Technology. Dept. of Chemical Engineering. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Bibliography: leaves 123-126. / M.S.

Page generated in 0.1009 seconds