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Thesis (M.S.)--University of Wisconsin--Madison, 1947. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes Bibliographical references (leaves 40-41).

Thesis (Ph. D.)--University of Pennsylvania.

Thesis (PH. D.)--University of Pennsylvania.

Thesis (Ph. D.)--University of Pennsylvania.

Thesis (Ph. D.)--University of Chicago, 1923.

An electron spin resonance study has been carried out at room temperature, on a magnetically dilute single crystal of ammonium 9-molybdomanganate. A general method for fitting E.S.R. results to a spin Hamiltonian has been devised, and the results of the above study have been used as an example of this method. The values of the parameters thus determined were⃒D⃒= 0.861 ± 0.001 cm⁻¹; g〟 = 1.9920 ± 0.0004 cm⁻¹; g⊥± = 1.9880 ± 0.0004 cm⁻¹;⃒A〟⃒= 0.00760 ± 0.00004 cm⁻¹;⃒A⊥⃒= 0.00684 ± 0.00004 cm⁻¹1. A review of previous theoretical calculations on d³ has been given, and a ligand field approach has been taken in an attempt to interpret the observed parameters. This was successful for the zero field splitting and hyperfine coupling constants, but not for the g-values. The experimental results from a study of an irradiated, single crystal of deuterated ammonium paramolybdate tetrahydrate have also been fitted to a suitable spin Hamiltonian. The principal axes of the g and A tensors were found not to be coincident, and a method for treating the experimental results in this situation has been given. This study showed that the doublet splitting observed earlier, in the E.S.R. spectrum of the irradiated, undeuterated compound, was most probably due to a captured proton. An interpretation of the observed g-values and hyperfine coupling constants has been given, using a molecular orbital approach. / Science, Faculty of / Chemistry, Department of / Graduate

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003. / Also available in electronic version. Access restricted to campus users.

In the modern ocean, manganese is oxidized over a timescale of days. To better understand the mechanisms and driving factors for manganese oxidation in the natural environment, experiments were performed with surface water samples collected from the San Antonio Bay. In this study area, the formaldoxime assay was utilized to determine that manganese oxidation is catalyzed via multiple pathways utilizing various catalysts and proximal oxidants. The contribution of catalysts such as colloidal matter, microorganisms and the proximal oxidant superoxide were investigated in the San Antonio Bay. The study suggests that superoxide contributed about 30% of Mn oxidation. The microorganisms and colloids were equal in terms of catalysis and accounted for approximately 100% of Mn oxidation. This study is important because gaining more understanding on the mechanisms by which Mn is oxidized will contribute to its use as a geochemical redox indicator.