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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

Characterization and chemical speciation modelling of saline effluents at Sasol Synthetic Fuels Complex-Secunda and Tukuta power station

Amon Nyamhingura January 2009 (has links)
<p>The study shows conclusively that brine composition and concentration is highly variable at these South African power utilities and processes such as RO, contact with ash and CO2 ingress can have an impact upon the overall brine quality. Aq.QA was found to be a more accurate tool for classifying waters according to dominant ions than Stiff diagrams but Stiff diagrams still have the superior advantage of being a mapping tool to easily identify samples of similar composition as well as quickly identify what has been added or what has been removed from a water stream. Chemical speciation could identify effluent streams where CO2 dissolution had taken place.</p>
102

Magnesium in hemipelagic environments : surface reactions in the sediment-pore water system

von Breymann, Marta T. 18 November 1987 (has links)
Graduation date: 1988
103

A review of the use of salt water for flushing in Hong Kong : project report /

Ip, Chi-kuen. January 1900 (has links)
Thesis (M. Sc.)--University of Hong Kong, 1993.
104

Inland saline aquaculture : overcoming biological and technical constraints towards the development of an industry /

Partridge, Gavin J. January 1900 (has links)
Thesis (Ph.D.)--Murdoch University, 2008. / Thesis submitted to the Division of Science and Engineering. Includes bibliographical references (leaves 123-154).
105

A prototype desalination system using solar energy and heat pipe technology

Alwaer, Ayad Almakhzum Mohamed January 2016 (has links)
Thesis (DTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2016. / The water desalination process needs large quantities of energy, either directly from fossil fuel or electricity from the national grid. However, these sources of energy significantly contribute to problems such as global warming in addition to creating a drain on the economy, due to their high cost. This dissertation is a description of the research undertaken with the aim of producing a water desalination prototype; a novel approach that was designed using state-of-the-art solar water heating equipment, incorporating the technologies of evacuated tubes and heat pipes. During the execution of the project, various modifications to the original commercially-available solar water heating system were attempted, each aimed at increasing the production of pure water. Finally, the system proved capable of producing a reasonable amount of pure water after twelve lengthy indoor experiments conducted in a laboratory in the department of Mechanical Engineering at the Cape Peninsula University of Technology, Bellville Campus, Cape Town, South Africa. Each experiment lasted five days on the basis of seven hours of exposure to an average amount of simulated solar radiation, followed by seventeen hours daily of inactivity and partial cooling down of the system.
106

Characterization and chemical speciation modelling of saline effluents at Sasol Synthetic Fuels Complex-Secunda and Tukuta power station

Nyamhingura, Amon January 2009 (has links)
Magister Scientiae - MSc / The study shows conclusively that brine composition and concentration is highly variable at these South African power utilities and processes such as RO, contact with ash and CO2 ingress can have an impact upon the overall brine quality. Aq.QA was found to be a more accurate tool for classifying waters according to dominant ions than Stiff diagrams but Stiff diagrams still have the superior advantage of being a mapping tool to easily identify samples of similar composition as well as quickly identify what has been added or what has been removed from a water stream. Chemical speciation could identify effluent streams where CO2 dissolution had taken place. / South Africa
107

Study of sorption properties of Eu on MX-80 bentonite under highly saline, reducing conditions, and under saline, reducing conditions

Yang, Jieci January 2021 (has links)
Pu (III) is one of the key elements in the safety assessments of Canadian deep geological repository program (DGR). Sorption is a potential mechanism for retarding radionuclide transport from a DGR to the environment. In the current scenario, Pu (III) is considered to be a dominant radioactive element in the deep geological groundwater. Eu, considered to be a chemical analogue of Pu (III), its sorption behavior is now the target of our research. This thesis investigates the sorption properties of Eu on MX-80 under saline reducing conditions, and highly saline reducing conditions. The thermodynamic sorption modelling of Eu is also need to be applied. A surface sorption model is also developed by applying computer program for Eu (III) on MX-80 to investigate the sorption mechanisms of Eu (III) sorption. / Thesis / Master of Applied Science (MASc)
108

Optimization of culture conditions and extraction method for phycocyanin production from a hypersaline cyanobacterium

Mogany, Trisha 08 August 2014 (has links)
Submitted in fulfilment of the requirements of the degree of Master of Technology: Biotechnology, Durban University of Technology, 2014. / Cyanobacteria contain phycocyanin a light harvesting pigment found to have numerous biotechnological applications, such as: a natural colorant in food and cosmetics, fluorescent tags employed in clinical and immunological research and also in therapeutic processes. Successful phycocyanin production depends on growth characteristics, ability to accumulate high quantities of the pigment, and an effective downstream process. Therefore, the aim of this research was to optimize the extraction method and production by determining the optimal cultivation conditions for phycocyanin producing cyanobacterium. This cyanobacterium was isolated from a hypersaline water body in Kwa-Zulu Natal, and subsequently purified using traditional streak and spread plate techniques. Different cell disruption techniques and a range of buffers were evaluated for the extraction of phycocyanin. The buffer concentrations and pH was subsequently optimized. Results showed that maximum phycocyanin was extracted when cells were suspended in 50mM sodium phosphate buffer (pH-7.5) supplemented with 10 % lysozyme and then disrupted using the freeze–thaw method at -20 & 4°C. The UV-Vis absorption spectral scan of the crude extracted pigments showed a peak at 620 nm. This corresponds to phycocyanin production. Unwanted proteins were removed using a 25and 50% saturated ammonium sulphate precipitation, followed by dialysis. SDS-PAGE showed two subunits with molecular masses of 19 and 20 kDa. These masses corresponded to phycocyanin α and β subunits. Furthermore, a food grade purity ratio (A615/A280) of 1.20 was achieved. The effects of various abiotic factors (temperature, light and pH) on growth and phycocyanin production of the Cyanothece sp. was investigated. Temperature ranging from 20-45°C and pH (5-10) was evaluated for 2 weeks. Cultures were then subjected to four photoperiods (24:0, 18:06 12:12 and 8:16 h light: dark) three light intensities (25, 75 and 125 µmol photons per m2 per –s) at varying wavelengths i.e. blue, red and green and Grolux light. Ideal conditions were observed at 35°C, 125 µmol photons.m2.s-1 of Grolux light for a 16:8 light and dark photoperiod. It was observed that the highest biomass and phycocyanin production was found to be at 35°C, temperatures below or above resulted in a decrease in both growth and pigment synthesis. Phycocyanin concentration changed in response to light quality and intensity. A significantly higher (p<0.05) phycocyanin yield was found when the culture was exposed to 125 µmol photons.m2.s-1 of Grolux light compared with the other three light conditions. Using Design of experiments, a series of fractional factorial experiments were carried out to optimize media components for pigment production. The final optimized growth medium was determined from a central composite design using response surface plots together with a mathematical point-prediction tool and consisted of 2g/L NaNO3, 0.06g/L K2HPO4, 0.12 g/L MgSO4.7H2O, 0.033 g/L CaCl2.2H2O, 100g/L NaCl, 12mL minor nutrients and 0.5 trace metal. A 72 % increase in phycocyanin was observed. This research revealed that this particular Cyanothece sp. shows great potential as a reliable source of phycocyanin.
109

RESPONSE OF BARLEY GENOTYPES TO NON-SALINE AND SALINE ENVIRONMENTS.

ELMIGRI, MOHAMED RHUMA. January 1982 (has links)
A 2-year study (1976-1977) was conducted at the Safford Experiment Station, Safford, Arizona to investigate the response of barley (Hordeum vulgare L.) genotypes to both non-saline and saline environments. The soil types was a Grabe Clay Loam. One environment had received only river irrigation water for the previous 10 years and throughout the experiment (non-saline environment) and the other environment had been irrigated with only well water for the previous 10 years and throughout the experiment (saline environment). Fifteen barley genotypes were grown in each environment each year. The following data were recorded for each genotype each year: (1) plant height, (2) lodging, (3) number of heads per hill, (4) number of seeds per head, (5) seed weight, (6) grain yield, (7) straw yield, (8) grain-to-straw ratio, (9) days from planting to flowering, and (10) days from flowering to maturity. The exchange capacity, soluble ions, and ESP of the soil irrigated with well water were all much higher than the exchange capacity, soluble ions, and ESP of the soil irrigated with river water. The soluble salts, calcium, magnesium, sodium, chloride, sulfate, bicarbonate, and sodium adsorption ratio were all much higher in well irrigation water than were the same chemical properties in river irrigation water. The foregoing soil and water chemical properties indicate that the non-saline environment should be much more conducive to optimum plant growth than the saline environment. Most of the barley genotypes germinated more uniformally, grew better, and produced more forage and grain in the non-saline environment than they did in the saline environment. It required a longer period for barley to reach maturity in the saline environment than it did in the non-saline environment. When the data from the two years were combined, there were positive correlations between grain yield and plant height, number of heads per unit area, and straw yield in both non-saline and saline environments. Since there were significant differences between barley genotypes in a number of growth and yield characteristics in both environments, it should be possible to develop improved barley cultivars for both non-saline and saline environments using plant breeding techniques.
110

Effect of saline waters on soil properties and plant nutrition in Kuwait

Abu-Fakhr, Mahmud Suleiman Sayyid Ahmad,1919- January 1961 (has links)
A field and pot culture study was undertaken in an attempt to determine the effect of saline solabeya water on soil salination, gatch formation and plant uptake of nutrients. Three gatch and three sandy soil profile samples were used in this studyo The soil samples were virgin profile 'A' samples from the Experim.ental Farm Extension, cultivated profile 'B' samples from. the Experim.ental Farm and cultivated profile '0' samples from Bid'a Nursery of the Education Department. The gatch samples were collected from sites 'A', '0' and plot No.6, of the Experimental Farm. Extension, Bidta Nursery and Experimental Farm respectively. Three indicator plants Lettuce (Lactuca sativa, variety Great Lakes), green beans (Phaseolus vulgariS, variety Black Valentine), and Petunia (Petunia hybrida) were used. The effect of soil texture, change in the reaction of the medium, concentration of solabeya saline water and soil solution on gatch formation were studied. A coarse sandy subsoil horizon high in silica constituted the proper medium for gatch formation. The major cementing agents were silica and the carbonates and hydroxides of calcium and magnesium. Alumina, iron oxide and gypsum. playa minor role in cementation due to their low concentration. An increase in the alkaline reaction and concentration of the saline solution favored precipitation of potential cementing agents present as soluble constituents of the medium. The presence of gatch and use of solabeya saline water lead to the formation of saline perched water table and soil salination. Different irrigation waters, representing various dilutions of solabeya saline water were used for irrigation of pot cultures. Different increments of nutrient solutions, supplying nitrogen, phosphorus, P9tassium, calcium, magnesium, and sodium were applied to the respective treatments of the pot cultures. The development, sequence of appearance, and severity of visual symptoms of general salinity effect showed direct corrolation with salt sensitivity of the indicator plant and the degree of salinity of the medium. In all cases, the symptoms were earlier and more severe in bean, followed by lettuce and petunia. As a result of cationic and anionic antagonism and an increase in the salinity of the medium, plant uptake of N, P, Ca, K, Fe and Mn was reduced, as revealed by the level of these elements in the leaves of the indicator plants, whereas the levels of Mg, Na, B, Cl, and SO₄ increased in the leaves of the indicator plants. The application of different increments of N, P, Ca, and K to the respective treatments of the indicator plant cultures resulted in a relative increase in the level of these elements in the leaves and a specific decrease in the level of the antagonistic elements. But, due to the effect of the increase in salinity of the medium of the respective treatments, and decrease in yield of green weight, the level of these elements maintained a gradual specific decrease in. the leaves.

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