Thesis (M.S.)--University of Wisconsin--Madison, 1961. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 149-152).

Thesis (M.S.)--University of Wisconsin--Madison, 1961. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 92).

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Vita. Includes bibliographical references.

Thesis (Ph.D.)--Tennessee Technological University, 2006. / Bibliography: leaves 47-50.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references (leaves 111-115). Also available in electronic version.

No description available.

Achromobacter w.t. and strain 14 both support phage α3a growth in stationary phase, but unlike the w.t. strain, exponential phase cultures of strain 14 block phage development. A standard method was developed for determining phage growth in stationary phase cultures. Lyophilised cells were used to eliminate variations due to the unstable phenotype of Achromobacter strain 14 cells. Phage α3a growth in stationary phase was characterized by a long and variable latent period of 6 to 9 h and an increased burst size of 709 p.f.u. per cell as compared with 153 p.f.u. per cell in exponential wild type cells. During the latent period the infected cells were very sensitive to changes in growth conditions and in particular, dilution. Pre-conditioning of the bacterial cells by allowing them to stand for 24 h after shaking for 3 days was an important aspect of the stationary phase phage growth system. Cells which had been allowed to stand retained the ability to be infected and to support phage growth for at least 16 days. Shaking cultures gradually lost the ability to support phage growth but the phage could persist in the host cell for 10 days until removal from shaking when the lytic cycle could proceed after allowing the cultures to stand. In comparison the latent period and burst size in Achromobacter w.t. stationary phase cells were reduced to less than 2 h and less than 200 respectively. Stationary phase cultures differed physiologically and morphologically depending on the aeration conditions. In comparison with non-aerated standing cultures, vigorously aerated cultures showed a decrease in viability, RNA synthesis, membrane transport, intracellular ATP levels, UV resistance and heat resistance but had markedly higher protein synthesis levels. Aerated cells were small non-motile rods which did not support phage growth. They developed into large motile rods under conditions of limited aeration and were able to propagate phage. It was proposed that changes in the host control mechanisms for macromolecular synthesis may be instrumental in either blocking or permitting phage development. A spontaneous mutant of Achromobacter strain 14 (14x) which liberated phage and was resistant to superinfection was isolated. The phage-host relationship was unstable and similar to the phage carrier state. The liberated phage were able to grow in exponential strain 14 cells. It was proposed that strain 14 was a defective lysogen and that an immunity phase shift model may account for the differential phage growth in exponential and stationary phase cells. Host transcriptional control appears to be implicated in control of phage development in exponential and stationary phase cells. Achromobacter Lp only supported phage in exponential phase but a rifampicin resistant mutant of this strain was able to propagate phage in stationary phase. In vitro RNA synthesis assays showed that the rifampicin resistance was caused by an alteration in the RNA polymerase. Preliminary experiments to determine intracellular phage macromolecular synthesis were carried out using exponential Achromobacter w.t. cells which had been irradiated with UV prior to infection. In irradiated cells, infection with phage resulted in stimulation of DNA synthesis but no stimulation of protein synthesis. Phage production was drastically reduced in cells which had been treated with very low UV doses. It was proposed that α3a development may rely heavily on host cell functions which are destroyed by UV. Achromobacter mutants with defective leucine transport systems were isolated. Mutants which lost the leucine uptake system completely were totally resistant to phage infection and were unable to adsorb phage α3a. This is the first report to implicate an amino-acid transport system in phage adsorption.

No description available.

Results of drained and undrained triaxial compressions tests on a sensitive clay are presented in this thesis. Contours of water content from both drained and undrained tests are compared, and it appears that for the clay tested, there is not a unique relationship between effective stresses and water content as found by Rendulic and Henkel for remolded soil. The Roscoe concept of a state boundary surface, which is similar to the Rendulic concept is examined, and it also does not hold for the clay tested. The Roscoe energy equation is applied to the results of all tests and it appears to hold quite well. It indicates that for a soil which is yielding there is only one fundamental strength parameter, M, which is independent of both strain and strain rate. Methods of predicting stress-strain relationships are examined. The Roscoe method, which is based on the existence of a state boundary surface is not strictly applicable, but does yield results which are of the same order as the measured relationships. The Landanyi method does not appear to apply to the clay tested. A method for predicting residual pore pressures and or permeability in drained triaxial tests is derived. This enabled allowances to be made for the effect of residual pore pressures in drained tests. However, it is felt that the method may have more application in the examination of soil structure, since a comparison of the permeability of samples at the same void ratio and temperature yields a measure of structural difference. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

The effect of a number of variables upon prestress anchorage length was investigated. The end zones of prestressed pretensioned concrete members were simulated by casting against steel bulkheads. 3/8" diameter strands and .276" diameter wires were used. Fifty specimens were tested. The variables investigated were; surface condition of prestressing steel, speed of release of prestress, water/cement ratio of concrete, age of concrete, stress in concrete, and vibration. A relationship between free end pull-in and anchorage length was found and is compared with the results of other investigators. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate