Browsing by Author "Sime, Richard Malcolm"

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    The advancement of downdraft gasification : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy at Massey University, New Zealand
    (Massey University, 1998) Sime, Richard Malcolm; Sime, Richard Malcolm
    Integrated gasification combined cycle systems (IGCC) are currently the most efficient (up to 40 % HHV) thermal method for the conversion of woody biomass to electricity. The production cost of electricity from IGCC is high, U.S. 6.6-8.2 ¢/kW.h (Graig and Mann, 1997). The capital costs alone are U.S. 3.2-4.5 ¢/kW.h. In New Zealand the wholesale price of electricity is typically less than U.S. 2.5 ¢/kW.h. The bottom line with current IGCC systems is that the capital cost must be greatly reduced if the technology is to be adopted for mainstream use. Methods to reduce the costs of all IGCC components should be investigated. The use of High Temperature & Pressure (HTP) downdraft technology as an alternative to the current fluidised bed technology could reduce the capital cost of the gasifier component of IGCC by 90%. The characteristics of the HTP downdraft are different from those of the traditional downdraft. A significant feature is that much larger throughputs are possible at gas turbine combustion pressures. The investigation of HTP downdraft technology is the focus of this thesis.
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    Sheep liver cytosolic aldehyde dehydrogenase : a fresh perspective : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Chemistry at Massey University, New Zealand
    (Massey University, 1995) Sime, Richard Malcolm
    The pre-steady-state mechanism of aldehyde dehydrogenase has been further investigated using synthesised deuterated 4-trans-(N,N-dimethylamino) cinnamaldehyde as a substrate. Reporter groups of the active site of ALDH have indicated the presence of a divalent or trivalent metal electrophile, shown in chapter 3 as being either Fe (II) or Fe (III) . Studies of the spectral properties of NADH bound to aldehyde dehydrogenase have revealed the presence of at least two spectrally different enzyme-NADH species. The consequences of this information are important in interpretation of the kinetic data and understanding apparently contradictory experimental results from different research workers. The steady-state kinetics of ALDH have been further investigated. A sensitive substrate for use in enzyme immunoassays has been designed and synthesised. The preliminary kinetic behaviour observed using this substrate has been studied with three enzymes. Aldehyde dehydrogenase has been used as a model system for studying the effects of electromagnetic radiation on biological systems.