No description available.

No description available.

A multichannel detection system based on a linear photodiode array (PDA) is described. The design and construction of the detection system and a rapid slew-scan computer-controlled stepping motor grating drive system is detailed. The theoretical performance of an optimized PDA system is contrasted with the performance of photomultiplier tubes. A technique is described which allows the dynamic range of the PDA to be extended by one order of magnitude towards higher light levels. A wavelength calibration procedure is outlined which results in a wavelength prediction accuracy of (+OR-)0.003 nm. A theory for high resolution spatial image positioning is presented and the ability to detect varying degrees of spectral overlap is evaluated. Applications of the PDA to the measurement and characterization of transient signals is described.

Analyses were made of concentrations of six elements (the micronutrients copper, iron, manganese and zinc, and the macronutrients calcium and magnesium) in samples of Triticum spetta and the soil they were grown on to investigate relationships between the two, and the possibility of sourcing material found in the archaeological record. Charred and fresh grains of geographically and geologically diverse locations were broken down in nitric acid using a microwave digestion technique. The resultant solutions were analysed by atomic absorption spectroscopy. Soil extractions using nitric acid and diethylene triamine penta-acetic acid allowed analyses of total and available elements. The results of soil / grain digests were investigated but no consistently significant relationships could be discerned. Growth experiments were performed by growing grain samples from various locations on one soil type to assess which factors were primarily important in elemental uptake. Calcium and magnesium uptake appears strongly influenced by the growing environment, but that of the micronutrients is additionally affected by genetic factors. In order to assess changes in elemental concentration due to burial, diagenetic experiments were carried out using grain from various locations and a series of differing burial periods. It was found that there was a trend for concentrations of the micronutrients and magnesium to decrease, whilst calcium concentrations increased substantially. On completion of work with modem grain, samples from the archaeological record were analysed. Elemental concentrations were found to be very different in ancient material and more significantly related to the burial environment. It appears possible to differentiate between leached, rural and waterlogged/urban sites.

No description available.

This study concerns the origin of a porphyry copper deposit. For the study 25 rock samples were taken from a porphyry copper deposit. Rock samples were analyzed for these trace elements: strontium, barium, copper, zinc, and vanadium. The results indicated that elevation correlations are not apparent for copper, zinc, and vanadium content, but definite correlations appear between strontium and barium content. This study determined that strontium is one of the trace elements which could be used as a possible exploration guide to porphyry copper mineralization. This study also provided that distribution of trace elements demonstrates the presence of a regional difference in the strontium and barium contents of the sample locations between the Dome Peak Quadrangle area and the Agnes Mountain area of the Cloudy Pass batholith; the volcanics of the former possess higher levels of strontium and barium concentrations.

Typescript. / Thesis (Ph. D.)--University of Hawaii, 1967. / Bibliography: leaves 243-254. / xv, 254 l illus., tables

Typescript. / Thesis (Ph. D.)--University of Hawaii, 1970. / Bibliography: leaves [76]-79. / vi, 79 l maps, graphs, tables

This thesis describes two studies of the chemistry of freshwater streams in the Sydney basin. The first was a survey of 86 waterways, sampled under low conditions. Samples were generally low in salinity, soft, of poor buffering capacity and dominated by sodium and chloride. C0-dominance by calcium, magnesium and (bi)carbonate occured in a number of particular cases. Multivariate analyses indicated three groups, separated primarily by levels of dissolved nutrients, trace metals, turbidity and colour. Groupings were associated strongly with the type of catchment. Streams in areas relatively unaffected by human influence had notable uniformity in chemistry, while those from developed catchments were varied. Heavy metal contamination was relatavely low, although a few of the samples displayed inordinately large levels of one or more metals. In such cases the more extreme measurements of phosphorus and nitrogen were also seen. The findings were consistant with occasional or localised elevation of contaminant levels. The second study invloved monitoring of three Hawkesbury Sandstone streams. Sampling of surface waters, interstial waters and sediments was performing at irregular intervals over a two year period at three stations within each site. The streams predominantly existed under low conditions and showed similar major ion chemistries to the majority of the survey samples. Levels of calcium and total carbonate, plus heavy metals and nutrients were generally higher in the urbanised creeks, comapred to the reference strema. During a heavy storm, high levels of nutrients, suspended solids and colour were detected in all surface waters at peak-flow, as well as alkaline pH, oxidising redox, and reduced conductivity, alkalinity and hardness. The sandy sediments were characterised by very low levels of organic matter and cation exchange capacity. Sequential extractions identified that the sums of secondary phase lead, zinc and copper were over nine, four and two times that of the corresponding residual, respectively. Greatest proportions of zinc and lead were associated with coatings of iron and maganese oxides, or coarse waste particles. Copper was preferentially associated with organic matter. Concentration gradients between interstitial and surface waters were rare and release of sedimentary constituents should occur from the upper-most particulates. Poor water and sediment qualities were often observed in the urban sites. Poor water quality was also seen on occassion in the reference stream. However, since poor sediment quality was not detected at those times and interstitial waters for all sites displayed high within-site variability, surface waters were considered the most reliable short-term indicator of condition for Hawkesbury Sandstone streams. Multidimensional scaling showed that all streams had distinct water and sediment chemistries. High levels of temporal and spatial variability were apparant within the urbanised sites - particularly in interstitial waters - mostly due to concentrations of heavy metals, phosphorus and suspended solids. Seasonal differences were detected, but only in terms of the level of variability between summer and winter samples.

Thesis (Ph.D)--University of Western Sydney, Nepean, 1994. / Includes bibliography.