<p> Mn2P2O7 belongs to the monoclinic space group C2/m. The manganese atoms are six-fold coordinated to oxygen atoms forming distorted octahedra. The bonding in P2O7^4- ion is discussed with reference to values predicted by Cruickshank and Baur.</p> <p> The central oxygen atom in P2O7^4-ion shows enhanced motion, a feature common to all the members of the thortveitite series. By collecting X-ray data at -180°C, an attempt has been made to understand the nature of this enhanced motion.</p> / Thesis / Master of Science (MS)

Presence of inclusions in high manganese steel are a major concern in the steel making industry, since these particles affect the processing and properties of the steel. During the refining of high manganese steel in the ladle furnace, the types of inclusions present and their growth in the liquid steel, or during solidification of the steel, caused by the addition of manganese and other alloying elements are to be examined. This research developed a kinetic model for the presence and growth of inclusions in the liquid high manganese steel for the ladle metallurgy process. The diffusion of dissolved elements, and the seed of inclusions for the growth and consumption of inclusions, were both addressed in the model. The present model for inclusions was coupled to the updated kinetic model for slag-steel reactions in the ladle furnace for high manganese steel. The coupled model allows for verifying the process analysis plant data for the highest manganese concentration presently available in the steel industry. Finally, an analysis of the coupled kinetic model was performed to compare the effect of the different processing conditions, and the presence and growth of inclusions in the high manganese steel from the ladle metallurgy process. / Thesis / Master of Applied Science (MASc)

<p> This project was undertaken with the aim of studying the distribution of copper, manganese and zinc in brain and to gain same information on the possible presence of soluble metallo-proteins in this tissue. The distribution of copper, manganese and zinc has been determined by neutron activation analysis. Soluble metallo-proteins of these three elements have been identified by the combination of gel chromatography and neutron activation analysis. In addition, in vivo and in vitro radioisotopic labelling techniques have been used occasionally.</p> / Thesis / Doctor of Philosophy (PhD)

The environmental mobility of Technetium-99 is inextricably tied to its oxidation state. Under oxidizing conditions Tc-99 predominates as the Tc(VII)O4- anion. This anion has a high solubility and is precluded from sorption on most soil or mineral surfaces, giving it a high environmental mobility. Under reducing conditions, Tc-99 predominates as Tc(IV)O2 or Tc(IV)2S7. Tc(IV) species tend to be insoluble and are therefore immobile. Due to this redox dichotomy, there has been significant interest in developing reductive immobilization strategies for Tc-99, particularly in anoxic environments where Tc(IV) is conventionally assumed to be stable. However, O2 is not the only common environmental oxidant. Many high valent manganese species are environmentally prolific and well known to exist in anoxic and overall reducing environments. These powerful oxidants can create localized oxidizing conditions in otherwise reducing environments. Limited research on the oxidation of Tc(IV) species has left a knowledge gap in the true recalcitrance of such immobilization forms in environmental settings. Our work aims to bridge this knowledge gap by studying the oxidation of Tc(IV) by various, environmentally common, high valent manganese species. Mn(III)-ligand complexes in particular have been overlooked. Up until recently, aqueous Mn(III) was assumed to be absent from the environment due to its disproportionation in aqueous systems without suitable complexing ligands. More recently, Mn(III)-ligand complexes have been shown to be prolific in a variety of natural waters. We have shown that various manganese oxides and Mn(III)-ligand complexes are capable of rapidly oxidizing Tc(IV) to Tc(VII), even in the absence of oxygen, resulting in dissolution of Tc-99 and release to the aqueous phase. This thesis presents novel information on the redox interface chemistry of Tc-99, which is crucial to developing effective remediation methods.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.