The fundamental characteristics and applications of inductively coupled plasma - optical emission spectrometry (ICP-OES) for forensic science purposes have been evaluated. Optimisation of ICP-OES for single elements using simplex techniques identified an ICP torch fitted with a wide bore injector tube as most suitable for multielement analysis because of a compact analytical region in the plasma. A suitable objective function has been proposed for multielement simplex optimisation of ICP-OES and its effectiveness has been demonstrated. The effects of easily ionisable element (EIE) interferences have been studied and an interference minimisation simplex optimisation shown to be appropriate for the location of an interference free zone. Routine, interference free determinations (<2% for 0.5% Na) have been shown to be critically dependant on the stability of the injector gas flowrate and nebuliser derived pressure pulses. Discrete nebulisation has been investigated for the analysis of small fragments of a variety of metal alloys which could be encountered in casework investigations. External contamination together with alloy inhomogeneity have been shown to present some problems in the interpretation of the data. A compact, corrosion resistant recirculating nebuliser has been constructed and evaluated for the analysis of small fragments of shotgun steels. The stable aerosol production from this nebuliser allowed a set of element lines, free from iron interferences, to be monitored with a scanning monochromator. The analysis, classification and discrimination of casework sized fragments of brasses and sheet glasses have been performed and a method has been proposed for the analysis of white household gloss paints. The determination of metal traces on hands following the handling of a variety of metal alloys has been reported. The significance of the results from these evidential materials has been assessed for forensic science purposes.

The absorption coefficient is a fundamental parameter in understanding the underwater light field, for solving the Radiative Tranfer Equation and understanding/interpreting remotely sensed data from the ocean. Measuring the absorption coefficient is particularly complicated in coastal areas where the optical properties of the water body are the result of a complex mixture of dissolved and particulate components, but mainly because of the interfering effect that scattering has upon the measurements. A great variety of in situ instruments and laboratory techniques have been developed to measure total absorption or the absorption by the various fractions that constitute the total absorption. They are, however, all affected by scattering and empirical corrections need to be applied. Among the instruments to measure absorption, a promising one appeared to be one based on an integrating cavity. Kirk (1995, 1997) outlined the principle and theory of an absorption meter based on an integrating sphere: a Point Source Integrating Cavity Absorption Meter (PSICAM). He argued that owing to its design, a PSICAM would be insensitive to scattering. A novel Monte Carlo code was written to simulate the behaviour of a PSICAM of various cavity radiuses. The results of the simulations carried out with this code showed that such an absorption meter should indeed be unaffected by scattering even with high levels of scatterers. One important disadvantage deduced from numerical modelling for a PSICAM is its sensitivity to the reflectivity of the integrating cavity. Several prototype PSICAMs of increasing quality were built and tested with scattering-free standard solutions. A major difficulty in the development of the prototype was found to be the calibration of the integrating sphere reflectivity. A final laboratory instrument made of a Spectralon sphere was built and tested with artificial and natural water samples containing different levels of scattering particles and compared with existing in situ and laboratory techniques: the ac-9 transmissometer and the filter paper technique for particulate absorption as well as measurement of Coloured Dissolved Organic Matter. Compared with the ac-9 transmissometer, the PSICAM showed remarkable agreement even for water with very high content of Suspended Particulate Matter. Very good correlations were obtained when compared with traditional CDOM measurement. In some cases, significant discrepancies occurred with filter paper measurements of particulate absorption. From laboratory to in situ experiments the PSICAM proved to be a reliable instrument assuming that the instrument was regularly and carefully calibrated. Finally, the PSICAM was deployed during a cruise around the Antarctic Peninsula where total and dissolved absorption measurements were carried out together with chlorophyll absorption measurements after extraction in acetone.

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The work described within this thesis is mainly concerned with the solution and refinement of the molecular structures of a variety of novel compounds. A number of X-ray and neutron diffractometers have been utilised for the analysis of specific compounds, depending on the nature of the investigation. Each of the instruments represented differing levels of computer automation and instrumentation. A powder diffractometer, representing old technology was interfaced to a microcomputer to enhance the instruments performance. A brief overview is given of the numerical processes involved in the elucidation and refinement of molecular structures from X-ray and neutron diffraction data. Particular attention has been placed on the role of computers to perform these calculations. The operation of the diffractometers employed in this study has been discussed comparing the benefits of each. A detailed report of the techniques used to enhance the low resolution diffractometer and of the experiments performed to highlight the increased performance has been included. Single crystal and powder diffraction studies were made of a wide variety of crystalline materials ranging from steroids to organometallic compounds. The X-ray structures were solved using Direct and Patterson vector methods from experimental data collected on a four circle diffractometer at Aberdeen University. Neutron diffraction experiments, performed at the Rutherford Appleton Laboratory, were commissioned to determine and refine the positions of the hydrogen atoms of two known structures, previously solved by Xray studies. Finally a critical evaluation of current computer automated diffractometers is presented, highlighting the new areas of instrument development.