The tests of performance of the modified thin-lens magnetic spectrometer using ring-detection have been extended using improved mechanical controls of detector position. The results show only a small improvement over the performance obtained previously in this laboratory. We conclude that the limit of performance with the thin-lens magnet has been reached. Further improvement: may be achieved only with a precision-wound magnet coil which will produce a completely symmetric field. The decay of [formula omitted] has been investigated using the modified thin-lens spectrometer, a scintillation spectrometer and beta-gamma, conversion-electron gamma coincidence techniques. The results support the simpler decay scheme proposed by Van Wijngaarden and Connor. The beta decay has three components with end-point energies and intensities of 659+3 kev(67 .3%), 411 kev (2.5%) and 89 kev (30.3%), estimated from the energy level intensity balances in Ba¹³⁴. These intensity balances show discrepancies of less than 3% of the total decay intensity. The conversion coefficients, calculated from the conversion electron and gamma-ray intensities lead to the following multipolarity identifications for the transitions in Ba¹³⁴; 473 kev (Ml or E2)j 563-569 kev (Ml or E2), 605 kev (E2), 797-803 kev (E2), 1036 kev (Ml or E2), 1168 kev (E2) and 1366 kev (E2), in agreement with other work. The Ml or E2 character of the 473 kev and 1036 kev transitions makes it possible to assign a spin of 3+ or 4+ to the 1641 kev level which was uncertain before. An unsuccessful search for evidence of a 960 kev gamma-ray reported by others puts an upper limit of 0.2% on its intensity. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

This study consists of an examination in detail of those facets of character, and conduct arising from character, which specifically account for the decay of the aristocracy of Yoknapatawpha; and by way of emphasis, of the specifically regenerative attitudes and actions which have sufficed to preserve various individuals of this class who have endured as fully adequate human beings.

0 / SPK / specialcollections@tulane.edu

The blurry, undefined edge of a city “is a philosophical region, where city and landscape overlap, existing without choice or expectation.” 1 This urban condition hardly ever influences the city’s core, leaving the periphery isolated, autonomous, and untapped. In this blurry zone, architectural opportunities present themselves. In New Orleans, a small Vietnamese community called Versailles lives in this undefined realm at the eastern boundary of the city. Its residents are removed from the core, disconnected by sheer distance, and wedged between ecology and industry. Typically, “that which literally lies on the margins often gets figuratively marginalized,” 2 but this community is resilient, taking full advantage of its overlap with the natural environment. A product of a forced migration in the wake of Saigon’s fall in 1975, this community drew on local parallels to Vietnamese climate and fishing commerce, allowing newcomers to morph this neighborhood into their own. Yet the scars of heavy industry still plague Versailles, which has endured a fraught history with nearby landfills. This thesis seeks to create productive frictions between community, ecology, and industry through exploring a blended topography where construction and landscape are commingled. This will allow for the architecture to be both anchored and stretched. The Eco-Line - part composting and gardening hub, part cultural and economic incubator, part ecological and recreational park - weaves a new edge of experience on New Orleans’s periphery. As opposed to forcing a connective intervention inward on New Orleans, the Eco-Line hugs the easternmost edge of Versailles, exploring a new urban condition that blends with the natural environment. / 0 / SPK / specialcollections@tulane.edu

Decay kinetics of bacteria in biological wastewater treatment systems are vital to efficient design and operation of treatment plants.  Of special concern are decay characteristics of fecal indicator organisms, which can aid design of wastewater treatment processes to eliminate fecal pathogens.  This study focuses on characterizing the decay of three strains of the key fecal indicator bacterium, Escherichia coli, and comparing microbial techniques for quantifying decay rates.  Traditional metrics for monitoring decay include volatile solids and plate counts, which may not provide the full picture of specific decay dynamics. In particular, the viable-but-not-culturable growth phase is challenging to assay.  Recently, more specific molecular techniques have been developed, such as DNA and RNA extraction with qPCR and RT-qPCR, ATP assays and live/dead cell-staining.  However, these assays have not been widely accepted or bench-marked against traditional techniques.  It is expected that molecular assays will generate kinetic constants that better reflect the viability and activity of the bacteria as they decay, generating a more integrated understanding of the decay process.  Cells grown in pure culture were spiked into microreactors and subjected to a variety of time/temperature treatments in both buffered pure culture and sludge matrices.  These scenarios were intended to mimic on a small scale typical waste treatment processes, more specifically pasteurization, thermophilic digestion and land application.  Results indicate decay curves similar to traditional curves but with constants that vary with respect to the strains and the characterization methods used.  The foundation laid by this work can be utilized in further studies involving other organisms in a variety of environmental scenarios. / Master of Science

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Pages 154 and 155 were not included in the thesis. / <p> The post-irradiation annealing of highly converted styrene-polystyrene systems was explored. Experimental conditions necessary for the entrapment of high concentrations of free radicals in such systems were investigated. They were found to bear a relation to the glass transition temperature of the system.</p> <p> The concentration of free radicals formed by subjecting the polymer-monomer systems to Gamma rays, at room temperature, was measured, and the subsequent GM and GP values were calculated. The structure of the formed radical was found to be in agreement with that suggested by previous investigators. The free radicals decay was examined at varied temperatures above and below Tgs, and was found to follow a second order mechanism. The activation energy of decay was found to increase by raising the temperature above Tgs.</p> <p> When irradiation was executed at temperatures below Tgs, post-irradiation annealing led to high rates of polymerization when carried out at temperatures above Tgs. </p> <p> The number average molecular weight was practically unchanged during the polymerization of the last few percent monomer.</p> / Thesis / Master of Engineering (MEngr)