Maternal and child undernutrition are a significant problem in the developing world, with serious consequences for human health and socio-economic development. In Cambodia, 55% of children, 43% of women of reproductive age, and 50% of pregnant women are anemic. Current prevention and control practices rely on supplementation with iron pills or large-scale food fortification, neither of which are affordable or feasible in rural Cambodia. In the study areas, 97% of women did not meet their daily iron requirements. The current research focuses on the design and evaluation of an innovative iron supplementation technique. A culturally acceptable, inexpensive and lightweight iron ingot was designed to resemble a fish species considered lucky in Khmer culture. The ingot, referred to as ‘try sabay’ or ‘happy fish’, was designed to supply iron at a slow, steady rate. Iron leaching was observed in water and soup samples prepared with the iron fish when used concurrently with an acidifier. More than 75% of daily iron requirements can be met with regular use. Its use in the common pot of soup or boiled water provides supplementation to the entire family. The effectiveness of the iron fish was investigated in a randomized community trial involving 310 women in rural Cambodia. Blood samples were taken at baseline and every three months thereafter, over a 12-month trial period. Significant increases in hemoglobin concentrations were observed in women allocated an iron fish when compared to controls throughout the study, with an endline difference of 11.6 g/L. Significant improvements in serum ferritin concentration were observed at 9 months (6.9 ng/mL) and endline (30.8 ng/mL) in women who used an iron fish regularly when compared to the control group. Overall, use of the iron fish led to a two-fold reduction in the prevalence of anemia. The supplement was used daily by 94% of the households at the end of the trial. The study highlights the acceptability and effectiveness of a fish-shaped iron ingot as a means of improving dietary iron content. It offers a promising, simple solution to iron deficiency anemia if the project can be scaled-up for use throughout the country. / Canadian Institutes of Health Research, University of Guelph, International Development Research Centre (Canada)

Artifacts found within the context of a shipwreck offer valuable insight into specific events surrounding a vessel’s journey and also have broader implications regarding the time period of the ship’s sinking. A collection of iron objects, excavated from the wreckage of a late Hellenistic ship carrying marble from the quarries at Proconnesus to the site of Claros, provides details of the implements vital to this ship’s passage. It was necessary that the completely corroded and encrusted iron artifacts undergo months of conservation, in the form of replication, stabilization of the iron where it survived, and restoration before they could be cataloged and researched thoroughly. The largest of the iron concretions was found to contain an anchor belonging to the ship. Being found on the same ship with wooden composite anchors, the iron anchor excavated at Kızılburun represents an important step in the transition in the use of wooden and lead composite anchors to their eventual replacement by anchors made solely of iron. The remaining identified objects comprise a collection of tools as well as three fasteners, all of which provide insight into the necessary equipment of an ancient wooden ship. Within the scope of this thesis, the conservation of each iron object is detailed, and a discussion of the implements enhances the understanding of their use aboard a seagoing vessel. Further research into similar objects and the development of each tool type offers insight into their value to the ancient seaman. Finally, a catalog of the artifacts is included, in order to provide measurements and technical drawings so that perhaps the currently unidentified artifacts can be compared to examples from other sites.

Iron oxyhydroxides are ubiquitous in surface environments, playing a key role in many biogeochemical processes. Their characterization is made challenging by their nanophase nature. Magnetometry serves as a sensitive non-destructive characterization technique that can elucidate intrinsic physical properties, taking advantage of the superparamagnetic behaviour that nanoparticles may exhibit. In this work, synthetic analogues of common iron oxyhydroxide minerals (ferrihydrite, goethite, lepidocrocite, schwertmannite and akaganéite) are characterized using DC and AC magnetometry (cryogenic, room temperature), along with complementary analyses from Mössbauer spectroscopy (cryogenic, room temperature), powder X-ray diffraction and scanning electron microscopy. It was found that all of the iron oxyhydroxide mineral nanoparticles, including lepidocrocite, schwertmannite and akaganéite were superparamagnetic and therefore magnetically ordered at room temperature. Previous estimates of Néel temperatures for these three minerals are relatively low and are understood as misinterpreted magnetic blocking temperatures. This has important implications in environmental geoscience due to this mineral group’s potential as magnetic remanence carriers. Analysis of the data enabled the extraction of the intrinsic physical parameters of the nanoparticles, including magnetic sizes. The study also showed the possible effect on these parameters of crystal-chemical variations, due to elemental structural incorporation, providing a nanoscale mineralogical characterization of these iron oxyhydroxides. The analysis of the intrinsic parameters showed that all of the iron oxyhydroxide mineral nanoparticles considered here have a common magnetic moment formation mechanism associated with a random spatial distribution of iv uncompensated magnetic spins, and with different degrees of structural disorder and compositional stoichiometry variability, which give rise to relatively large intrinsic magnetization values. The elucidation of the magnetic nanostructure also contributes to the study of the surface region of the nanoparticles, which affects the particles’ reactivity in the environment.

Thesis--M. Med. Sc., University of Hong Kong, 1984.

No description available.

Iron oxyhydroxides are ubiquitous in surface environments, playing a key role in many biogeochemical processes. Their characterization is made challenging by their nanophase nature. Magnetometry serves as a sensitive non-destructive characterization technique that can elucidate intrinsic physical properties, taking advantage of the superparamagnetic behaviour that nanoparticles may exhibit. In this work, synthetic analogues of common iron oxyhydroxide minerals (ferrihydrite, goethite, lepidocrocite, schwertmannite and akaganéite) are characterized using DC and AC magnetometry (cryogenic, room temperature), along with complementary analyses from Mössbauer spectroscopy (cryogenic, room temperature), powder X-ray diffraction and scanning electron microscopy. It was found that all of the iron oxyhydroxide mineral nanoparticles, including lepidocrocite, schwertmannite and akaganéite were superparamagnetic and therefore magnetically ordered at room temperature. Previous estimates of Néel temperatures for these three minerals are relatively low and are understood as misinterpreted magnetic blocking temperatures. This has important implications in environmental geoscience due to this mineral group’s potential as magnetic remanence carriers. Analysis of the data enabled the extraction of the intrinsic physical parameters of the nanoparticles, including magnetic sizes. The study also showed the possible effect on these parameters of crystal-chemical variations, due to elemental structural incorporation, providing a nanoscale mineralogical characterization of these iron oxyhydroxides. The analysis of the intrinsic parameters showed that all of the iron oxyhydroxide mineral nanoparticles considered here have a common magnetic moment formation mechanism associated with a random spatial distribution of iv uncompensated magnetic spins, and with different degrees of structural disorder and compositional stoichiometry variability, which give rise to relatively large intrinsic magnetization values. The elucidation of the magnetic nanostructure also contributes to the study of the surface region of the nanoparticles, which affects the particles’ reactivity in the environment.

Flux of ferrous iron (FeII) to the estuarine environment, whether from bottom sediments or via groundwater seepage, has been identified as a potentially important source of iron required for the development and sustenance of nuisance blooms of the toxic cyanobacteria Lyngbya majuscula in Moreton Bay, Queensland. However the rapid oxidation of FeII in seawater imparts importance to the resultant form of ferric iron (FeIII). Oxidation of FeII in the presence of natural organic matter (NOM) results in a mixture of FeIII-NOM complex and amorphous ferric oxides (AFO). The fate of these oxidation products has implications for the supply of iron to L. majuscula where transformations over time scales of hours are likely to be important. In this thesis the process of oxidation of FeII in seawater in the presence of NOM and the subsequent transformations of the products of oxidation are investigated. UV and visible spectroscopic techniques were used to monitor the production of organically complexed FeIII for both NOM and a model organic compound. Kinetic modelling of data facilitated the examination of key reactions, especially those involving AFO. Controls on the reactivity and aging of AFO were investigated using two different dissolution reactions to measure reactivity. Light scattering techniques were used to probe the structure of AFO and X-ray absorption spectroscopy was used to examine the coordination environment of Fe centres within AFO. Analysis of a kinetic model of iron transformations parameterised using the best available knowledge revealed large uncertainty surrounding the role of ligand classes in complex formation and dissociation and the role of AFO in both formation of oxidation products and the subsequent decay of organically complexed FeIII. Laboratory studies demonstrated that, within a wide range of initial concentrations, unstable mixtures of FeIII-NOM and AFO are produced from the oxidation of FeII in seawater containing NOM and that the organic complexes immediately commence transformation to AFO. Simulation using numerical kinetic modelling of the processes investigated indicated that AFO has a significant role in the processes of formation of oxidation products and dissociation of organically complexed FeIII. The rapid aging that AFO was recognised to undergo was successfully incorporated into the model though whether the aging was due toeither 1) increased coordination of Fe centres or 2) decreased Fe centre accessibility due to aggregation could not be ascertained from the model results. However, together with information regarding the coordination environment of the Fe centres and the particle and fractal structure of the aggregates, aggregation was considered most likely to be the factor responsible for the observed and modelled decreases in AFO reactivity.

Flux of ferrous iron (FeII) to the estuarine environment, whether from bottom sediments or via groundwater seepage, has been identified as a potentially important source of iron required for the development and sustenance of nuisance blooms of the toxic cyanobacteria Lyngbya majuscula in Moreton Bay, Queensland. However the rapid oxidation of FeII in seawater imparts importance to the resultant form of ferric iron (FeIII). Oxidation of FeII in the presence of natural organic matter (NOM) results in a mixture of FeIII-NOM complex and amorphous ferric oxides (AFO). The fate of these oxidation products has implications for the supply of iron to L. majuscula where transformations over time scales of hours are likely to be important. In this thesis the process of oxidation of FeII in seawater in the presence of NOM and the subsequent transformations of the products of oxidation are investigated. UV and visible spectroscopic techniques were used to monitor the production of organically complexed FeIII for both NOM and a model organic compound. Kinetic modelling of data facilitated the examination of key reactions, especially those involving AFO. Controls on the reactivity and aging of AFO were investigated using two different dissolution reactions to measure reactivity. Light scattering techniques were used to probe the structure of AFO and X-ray absorption spectroscopy was used to examine the coordination environment of Fe centres within AFO. Analysis of a kinetic model of iron transformations parameterised using the best available knowledge revealed large uncertainty surrounding the role of ligand classes in complex formation and dissociation and the role of AFO in both formation of oxidation products and the subsequent decay of organically complexed FeIII. Laboratory studies demonstrated that, within a wide range of initial concentrations, unstable mixtures of FeIII-NOM and AFO are produced from the oxidation of FeII in seawater containing NOM and that the organic complexes immediately commence transformation to AFO. Simulation using numerical kinetic modelling of the processes investigated indicated that AFO has a significant role in the processes of formation of oxidation products and dissociation of organically complexed FeIII. The rapid aging that AFO was recognised to undergo was successfully incorporated into the model though whether the aging was due toeither 1) increased coordination of Fe centres or 2) decreased Fe centre accessibility due to aggregation could not be ascertained from the model results. However, together with information regarding the coordination environment of the Fe centres and the particle and fractal structure of the aggregates, aggregation was considered most likely to be the factor responsible for the observed and modelled decreases in AFO reactivity.

Thesis (M.S.)--University of North Carolina at Greensboro, 2007. / Title from PDF t.p. (viewed Feb. 29, 2008). Directed by Deborah Kipp; submitted to the School of Human Environmental Sciences. Embargoed until Dec. 20, 2008. Includes bibliographical references (p. 47-56).

Thesis (MSc)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.