The contamination of groundwater by arsenic is currently a major concern in Bangladesh. Arsenic in groundwater was first detected in 1993 following reports of many people suffering from arsenical diseases. Further investigations showed the extent of the problem with large areas of the country's water supply being affected and millions of people at serious risk of arsenic poisoning. Technology for arsenic removal from water already exists. However, the socioeconomic conditions which prevail in Bangladesh, do not permit implementation of this type of technology on grounds of cost. The main objective of this study was to develop a low cost technique for the removal of arsenic from contaminated groundwater using the naturally occurring iron, which is another water quality constraint in Bangladesh. The approach was to form arsenic-iron complexes by coprecipitation and adsorption of arsenic on iron. It has been demonstrated that provided the iron levels are sufficiently high (say >_ 1.2 mg/1), simple shaking of a container and allowing the arsenic-iron complex to settle out for 3 days could reduce the concentration of arsenic from 0.10 mg/l to Bangladesh standard (0.05 mg/1). In experimental program, As(III) form of arsenic was used as this form is more likely to be present in groundwater. From laboratory studies, it was shown that the removal rate was largely controlled by the Fe/As ratio, pH and the As concentration. Arsenic removal increases with increasing Fe/As ratio and is favoured by increasing pH in the range of 5 to 8. Separation of the precipitates was achieved by settlement. Following prolonged settlement, it was found that arsenic removal could exceed the removal achieved by filtration through a 0.45 μm filter paper. The experiments demonstrated that about 77% arsenic removal could be achieved from water containing 0.2 mg/l As(III), 4.0 mg/1 Fe at pH 7.5 by manual flocculation (1 min manual mixing) and 3 days settlement. The use of ordinary charcoal, which is cheap and easily available, was investigated for removal of arsenic and was found to be ineffective. From maps of the known distributions of As, Fe and pH, it was evident that 63% of the area in Bangladesh complied with the Bangladesh standard for arsenic. By interpreting the maps and applying the potential removal by coprecipitation-adsorption and settlement technique, it was estimated that a further 8% of area would comply with the Bangladesh standard freeing an additional 7 million people from arsenic contamination.

The aquatic filamentous bacteria (Cyanobacterium) Lyngbya majuscula is a nitrogen-fixer found in coastal waters often attached or adjacent to sea grass, algae and coral. It is characterized by phycobiliproteins, unique pigments found only in cyanobacteria. To sustain photosynthesis and nitrogen fixation, L. majuscula requires iron proteins and is therefore sensitive to the availability of this metal. The hypothesis tested in this study concerns the potential use of hyperspectral imaging in detecting L. majuscula in coastal regions as biological indicators for the presence of iron debris or metal objects in the littoral environment. This concept would have potential benefits and applications in mine detection and countermeasure techniques. Using a USB2000 field spectroradiometer, a spectral library was developed for the benthic substrates of Midway Atoll, Northwest Hawaiian Islands, spectrally characterizing L. majuscula and the surrounding coral reef substrates. The data was analyzed to determine unique spectral characteristics of the benthic cyanobacteria in a mixed coral environment and evaluated against the resampled spectral resolution of a number of hyperspectral sensors: Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), Hyperspectral Mapper (HyMap) and Compact Airborne Spectrographic Imager (CASI). The results of the in situ spectroscopy suggest a strong potential for all three sensors to detect these cyanobacteria in a mixed coral reef environment at four distinct wavelengths attributable to phycobiliprotein pigment absorptions unique to cyanobacteria. Of these four discriminative absorption ranges, the phycoerythrin absorption of 565-576 nm shows the greatest potential for segregating cyanobacteria from a mixed algal/ coral / sand environment so long as the coral Montipora spp. is not present within the scene, since it has an overlapping absorption in those wavelengths. In the presence of Montipora corals, these cyanobacteria are more difficult to detect. However, in a mixed environment composed of L. majuscula and Montipora corals, the cyanobacteria can be distinguished by a different phycocyanin absorption, at 615-632 nm.

Iron deficiency is one of the most common nutritional disorders worldwide. It is especially serious during pregnancy with serious health consequences for both the mother and her developing fetus. In humans these include fetal growth retardation, impaired cognitive development and premature birth. In rats, the pups born to iron deficient mothers are smaller, with changes in liver and heart size. As adults, the offspring develop hypertension and obesity. Why these changes occur is not clear. One possible hypothesis is that iron deficiency changes the cell membrane. I aimed to investigate this hypothesis, using an in-house iron deficient maternal rat model, designed by our group, additionally I have designed an iron deficient human liver hepatoma cell line model (HepG2). The effect of iron deficiency on maternal and neonatal erythrocytes membranes was tested. Iron deficiency significantly increased the mothers’ erythrocytes sensitivity to low osmotic pressure. In contrast, the neonates’ erythrocytes sensitivity was not affected by iron deficiency. The effect of iron deficiency on membrane protein profile was also studied in maternal and neonatal liver total membrane proteins, using proteomics analysis. Mitochondrial proteins were the most affected, especially in neonates. Whole cell patch clamp recording was used to study the effect of iron deficiency on the membranes’ electrophysiological properties. HepG2 cells had linear current-voltage relationships between -130 and +60 mV. Furthermore iron deficiency reduced the membranes’ input resistance reflected by an increase in holding current and in slope conductance. These changes were not reversed by K+ channel blockers (Ba2+ and quinine) suggesting no change in K+ channel protein expression. Interestingly and unexpectedly it increased the change in conductance, Sr2+ had a similar effect. Therefore iron deficient membranes had increased permeabilit

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A thesis presented for the degree of Doctor of Philosophy in Medicine of the University of the Witwatersrand, Johannesburg 1972 / For centuries iron was regarded as a source of health and vigour, and it has been known for at least 200 years that it is a component of blood and effective in the treatment of chlorosis. However, its metabolism remained largely a mystery until the advent of radioactive iron isotopes in 1938. Since then most of the major pathways of this metal into, through and out of the body have been elucidated. In addition the functions which it subserves have been partially characterized. / IT2018

A dissertation submitted to the Faculty of Medicine University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the Degree Master of Science in Medicine / Ferritin is an iron storage protein, made up of heavy (H) and light (L) subunits. Ferritin synthesis is regulated at a post transcriptional level by iron, which induces a redistribution of ferritin mRNA from a free cytoplasmic pool to polyribosomes. Inflammatory states influence iron metabolism, causing a decrease in serum iron levels associated with an increase in reticuloendothelial ferritin synthesis and iron storage. / IT2018

Thesis Submitted to the Faculty of Medicine University of the Witwatersraiu', Johannesburg for the Degree of Doctor of Philosophy (Medicine) Johannesburg 1976 / An attempt was made to fortify sugar with iron in order to prevent the development of iron deficiency. It was possible to add various iron salts and ascorbic acid to sugar without discolouring the vehicle even after storage for many months under hot humid conditions. The absorption of iron from fortified sugar and cereal meals was then measured in human volunteers using either an "extrinsic tag" to label the iron compound or intrinsically labelled food iron. / IT2018

A research dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering, 2016 / The Fe-Al alloys have been viewed as attractive for applications in the energy sector, for example boilers and pipes in power plants. As such, improvement of the properties of an Fe-40 at.% Al alloy were attempted by adding small amounts of precious metal to the alloy. An Fe-40 at.% Al alloy produced by melting and casting in a button arc furnace, showed very large grains in the microstructure and had a hardness of ~400HV. Precious metals (Ag, Ru, Pt, Pd) were added in amounts of either 0.2 at.% or 0.5 at.%. Additions of Ag and Ru were found to decrease the hardness, but the addition of Pt and Pd did not affect the hardness significantly. Oxidation testing of the alloys showed that they were very resistant to oxidation, although there was some small internal oxides in the sample containing Pt. Corrosion testing of the samples showed that the precious metals helped to greatly decrease the corrosion rate of the FeAl alloy in H2SO4. The mechanical alloying and sintering parameters were first optimised using the plain FeAl alloy and the sintered plain FeAl had significantly smaller grains than the as-cast material under all conditions, and that the hardness had increased as a result. The mechanical alloying also produced a carbide phase in the material that was not able to be removed. After mechanical alloying and sintering of the precious metal containing alloys, the microstructure had been refined slightly more than plain FeAl in all the alloys, except that containing Ru, which was the same as the plain alloy. The presence of Pt and Pd increased the hardness of the alloy slightly, while Ru and Ag produced no change. Oxidation testing showed that the sintered compacts had significantly less grain growth than the as-cast samples, and that generally the oxidation resistance was good. The exception to this was the sample containing Pd, which showed sub-surface oxidation. Corrosion testing of the sintered compacts showed that the Ru and Pt containing alloys performed better than the as-cast alloys. Both the Pd and Ag containing samples suffered from pitting, and the Pd sample was corroded away completely during the test in 3.8M H2SO4 solution. It was concluded that there was a significant effect on the microstructure of the FeAl alloy due to the processing route used, and that this also produced a significant effect on the hardness and corrosion resistance, with both improving when non-equilibrium processing was used. The presence of precious metals in small amounts increased the corrosion resistance of the alloy, and overall, only produced small changes in the hardness, and oxidation properties of the alloy. / GR2016

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the academic requirements for the Degree of Master of Science. March 2016. / Tungsten carbide (WC) is characterized by its high strength, toughness, hardness, its high resistance to wear and can also be employed at high temperatures. It is used mainly in the form of cemented tungsten carbides which are produced by combining grains of tungsten carbide into a binder matrix element, for example cobalt (Co). Tungsten carbide is commonly used in industrial machinery as cutting tools and abrasives. The primary aim of this project is to investigate the effects of iron (Fe) as an alternative/additional binder in a tungsten carbide system. Therefore, two samples WC-10wt%Co-6wt%TiC and WC-10wt%Co-6wt%TiC-20wt%Fe alloys were prepared by milling and followed by sintering. Several studies have been undertaken in this project to ascertain the effect of Fe on the structural, electronic, magnetic and physical properties of the as-milled and as-sintered samples. A number of different experimental methods were applied to give such information. Transmission Mössbauer spectroscopy and conversion electron Mössbauer spectroscopy were employed as the main techniques to determine the charge states of Fe, Fe phases and other complex phases in the WC-10wt%Co-6wt%TiC-20wt%Fe alloy from the hyperfine interaction parameters. In addition, applied Vickers hardness test, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and strain analysis were utilized as complementary characterization techniques. The Vickers hardness value of 1358±70 HV was measured for the WC-Co-TiC sample whilst a lower value of 820±41 HV was found for the WC-Co-TiC-Fe sample. The microstructure analysis (SEM/EDS) confirmed the presence of WC in the matrix, and Co, Ti, and Fe as the binder elements. XRD results show the formation of the FeCo alloy in the as-milled powder and as-sintered samples. The strain analysis was performed on the as-milled powder, and the as-sintered samples by adopting the method used in accordance with the Topas description, defined in the Topas manual. The WC-Co-TiC sample showed that the tungsten carbide phase appears to have little strain whilst the titanium carbide phase appeared to have no strain. In the WC-Co-TiC-Fe sample, all phases show no strain. The Mössbauer spectrum at room temperature acquired from transmission Mössbauer spectroscopy was fitted with one sextet S1 attributed to -Fe. Best fits to the data obtained from conversion electron Mössbauer spectroscopy required four spectral components: two sextets S1 and S2 assigned to FeCo, one doublet D1 assigned to FeWC and one single SL1 assigned to FeTi alloy. / LG2017

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