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Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1976. / Bibliography: leaves 162-177. / Microfiche. / 177 leaves ill

125 leaves : ill. ; 26 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1972) from the Dept. of Physics, University of Adelaide

Thesis (M.S. - Soil and Water Science)--University of Arizona, 1989. / Includes bibliographical references (leaves 91-93).

Thesis (B. Ag. Sci.(Hons.))--University of Adelaide, 1961. / Includes bibliographical references (leaves 67-70).

Thesis (B. Ag. Sci.(Hons.))--University of Adelaide, 1961. / Includes bibliographical references (leaves 131-135).

Thesis (M.S.)--University of Wisconsin--Madison, 1969. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Introduction: Part 1. Greenhouse studies were conducted to investigate the absorption of sodium, potassium, calcium and magnesium by lemon seedlings. The plants were grown in controlled nutrient solutions and analysis of the plant material was made to determine the relationship between the four cations in the different plant organs. Results of the experiment may be summarized as follows:- The occurrence of leaf burn appeared to be associated with a low calcium content, together with a high sodium, potassium or sodium + potassium content. The development of the seedlings was shown to be markedly influenced by the level of calcium supply and to a much lesser degree by the level of potassium supplied. The concentration of sodium, potassium, calcium and magnesium in the stem and leaf varied with position of the tissues on the main axis. The level of sodium was found to influence the distribution of sodium in the leaves, and the sodium content of the leaf, stem and root tissues gave a good reflection of the level of sodium supplied. The effect of the sodium treatment on the uptake of potassium appeared to be dependent on the calcium content of the tissues. Sodium treatment was found not to affect the leaf calcium content. In the stem and root tissues the calcium content was reduced when the calcium level in the nutrient medium was low, and increased the calcium content of these two tissues at the higher level of calcium supply. The sodium supply was shown to reduce the leaf magnesium only slightly, and its affect on the magnesium content of the stem and root tissues was shown to be dependent on the level of calcium supplied. The potassium content of the leaves, stems and roots increased when the supply of potassium was raised. Increasing the potassium level in the nutrient supply was found to cause a very slight reduction in the sodium content of the leaf, but did not affect the sodium content of the stem and root. Potassium did not affect the calcium content of the leaves and increased the stem calcium when sodium was not present in the nutrient media in high concentrations. In the roots potassium only increase the calcium content at the upper level of calcium supply. The magnesium content of the leaf and stem tissues was reduced as the potassium supply was increased. In the roots the general trend was for the magnesium content to increase when the level of potassium treatment was raised. The calcium content of all the plant parts increased with a rise in the calcium supply, the stem and root tissues having a greater percentage increase than the leaves. The sodium content of the plant tissue was reduced as the level of calcium supply was raised. The leaf potassium content decreased with a higher calcium level of supply. In the stem and roots the potassium content was increased by doubling the calcium supply. The calcium treatment had no influence on the magnesium content of the foliage, but in the stem and root tissues a decrease in magnesium content resulted from an increase in the calcium supply. Part II Potato tuber tissue and carrot root tissue were used as experimental material in the investigation of sodium9 potassium9 and calcium uptake by storage tissue. It was shown that when the tissue disks are transferred from distilled water to a solution of salts there is a rapid initial uptake of cation which is neither particularly selective, nor related to metabolism, but dependent on the external concentration. On the other hand, the prolonged active accumulation of cation exhibits selectivity. Potassium absorption by potato tuber tissue was shown to be stimulated by sodium9 whereas the potassium and calcium absorption by carrot root tissue was shown to be reduced by sodium. Similarly the sodium absorption by the carrot root tissue was reduced by potassium, thus suggesting that the cations compete with one another for the same absorption mechanism.

. The kinetics of the absorption of carbon monoxide by basic solutions was studied at 80°C and carbon monoxide pressures up to 30 atmospheres. The reaction was followed by the rate of decrease of carbon monoxide pressure in a closed system. The observed kinetics in potassium hydroxide solutions yield a rate law of the form (formula omitted) No influence from Li⁺, Na⁺, K⁺ ions was detected and no catalytic effect from Ag(I),- Cu(II), T1(I), N0₃⁻, Mn0₄⁻ was observed. The kinetics are consistent with a mechanism which includes the insertion of a carbon monoxide molecule into the hydroxyl bond,viz. (formula omitted) The rate-controlling step above 90°C was found to be the mass transfer of carbon monoxide from the gas phase into the liquid phase under the conditions involved in this study. / Applied Science, Faculty of / Materials Engineering, Department of / Graduate

Two soil types, the Ladner silty clay loam and the Nicomekl loam, located in the Lower Fraser Valley, representing the modal profile characteristics were selected to study the permeability and the factors affecting it. Undisturbed core samples and fragmented samples were procured for laboratory characterization of the soils. Measurement of the soil permeability in the laboratory confirmed the field observations that the Nicomekl soil was more permeable than the Ladner soil. There was a good correlation in the soil permeability and the soil macroporosity as determined by tension table at 40 cm. water tension. The texture of the two soils, as determined by pipette method, was not sufficiently different to account for the permeability differences. The variations in the organic matter content, as determined by wet combustion method, seemed to have little effect on the permeability behaviour of these soils. The nature of exchangeable cations, as extracted by the ammonium acetate method and quantitatively determined by flame photometry and versenate titration, in the two soils, were found to be very different; the exchangeable cations, Na⁺, K⁺ and Mg⁺⁺, in the Ladner soil seemed responsible for the lower permeability in comparison with the Nicomekl soil which had very low percent base saturation and appeared to have mostly Al⁺⁺⁺ ions present in the exchange complex. The poorer physical conditions of the Ladner were also, perhaps, due to the differences in the exchangeable cations. The X-ray identification of clay minerals, using oriented "aggregate technique", monochromatic copper radiation and surface reflection method, revealed that the Ladner and Nicomekl soils were qualitatively similar in their clay content. Both soils contained montmorillonite, micaceous mineral, chlorite, feldspar and quartz; the presence of kaolinite and vertniculite could not be established. In an intricate mixture of clays as above, quantitative estimation of clay minerals was not performed; hence the effect of clay minerals on the permeability of the two soil types could not be evaluated. Permeability measurements on soil mixtures containing reference clay minerals, using air pressures in a water permeameter, revealed that Na-Bentonite even in small quantities rendered soil highly impermeable. The permeability of soil mixtures containing clays with exchangeable calcium improved with the application of Krilium while the clays with exchangeable sodium did not respond to similar treatment. The effect of Al⁺⁺⁺ ion and weak acids on the flocculation behaviour of Na-Bentonite suggested that the presence of both Al⁺⁺⁺ ions and weak acids promoted soil permeability. X-ray diffraction diagrams using unflitered cobalt radiation indicated that weak acids formed heat stable complexes with bentonite. The bentonite treated with aluminum chloride as well as phosphoric acid plus aluminum gave diffraction patterns indicating that increased c-spacing was due to the complexes formed with bentonite; the deposition of these complexes at the interlayer positions prevented the complete collapse of lattice at elevated temperatures. / Land and Food Systems, Faculty of / Graduate