Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Report (M.S.)--Virginia Polytechnic Institute and State University. M.S. 1991. / Vita. Abstract. Includes bibliographical references (leaves 75-76). Also available via the Internet.

Thesis (M.S.W.)--Smith College School for Social Work, Northampton, Mass., 2009. / Includes bibliographical references (p. 62-68).

Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 273-288). Available also in a digital version from Dissertation Abstracts.

Thesis (M.S.) PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / Recovery from aphasia, loss of language following a cerebrovascular incident (stroke), is a complex process involving both left and right hemispheric regions. In our study, we analyzed the relationships between semantic processing behavioral data, lesion size and location, and functional signal change from functional magnetic resonance imaging (fMRI) data. Our study included 14 persons with aphasia in the chronic stage of recovery (six or more months post stroke) who performed semantic processing tasks of determining whether a written semantic feature matched a picture or whether two written words were related. Region of interest (ROI) analysis revealed that left inferior frontal gyrus pars opercularis and pars triangularis, despite significant damage, were the only regions to correlate with behavioral accuracy. Additionally, bilateral frontal regions including superior frontal gyrus, middle frontal gyrus, and anterior cingulate appear to serve as an assistive network in the case of damage to traditional language regions including inferior frontal gyrus, middle temporal gyrus, supramarginal gyrus, and angular gyrus. Contralesional posterior regions including right middle temporal gyrus, right supramarginal gyrus, and right angular gyrus are engaged in the case of complete damage to left hemisphere language regions. Additionally, right inferior frontal gyrus pars orbitalis is noted to be possibly serving a monitoring function. These results reinforce the importance of the left hemisphere in language processing in aphasia, as well as the nuanced relationships between lesion size, lesion location, and bilateral signal change in aphasia. / 2031-01-01

PURPOSE: This qualitative study explores the perceptions of women diagnosed with Opiate Use Disorder enrolled in Methadone Maintenance Treatment (MMT). The purpose is to gain an understanding of the women’s perceptions of their treatment and recovery. RESEARCH QUESTIONS: Research questions explored: the women’s experiences and perceptions related to recovery on dimensions such as family, social network, sense of identity, motivations for continued recovery, and relapse prevention methods; their belief in their ability to succeed; changes in personal identity from a drug user to a non-drug-user; and the role of the methadone medication in their recovery. SAMPLE: Criteria included women 35-50 years of age with a history of opioid addiction for at least 5 years; regular attendance at the Methadone program; abstinent from alcohol and illicit drugs for 12- 18 months. RESEARCH DESIGN: A convenience sample of thirty-one women was interviewed using semi-structured interviews, conducted by the PI. Open-ended questions were asked to elicit the women’s views. The PI conducted a record review to verify that the women had a history of opioid addiction, were regular attendees of the MMT program, and had maintained the period of abstinence that they reported. Methods included Thematic Analysis. THEORETICAL FRAMEWORKS: Guiding frameworks were the Developmental Model of Recovery (Brown, 1985), describing healthy adaptation following a period of debilitation, and Symbolic Interactionism (Blumer, 1969), describing social interactions as mutually developed exchanges to which individuals bring their own symbolic meanings. FINDINGS: These women had positive perceptions of their recovery and changes in themselves including becoming more responsible, reuniting with their families and developing personal insight. They saw methadone as crucial to their recovery. Although they saw themselves as fairly well along in recovery, they believed they could not be fully recovered until they were off methadone. IMPLICATIONS: Findings help us understand the women’s perception of how MMT and behavioral and personal changes contributed to their recovery. Although these women, who were abstinent and treatment-compliant for at least one year, were able to ignore or reframe their experiences of methadone stigma, the stigma may contribute to treatment drop out for some women, especially early in treatment

No description available.

No description available.

The important role of black liquor in the pulp and paper industry has, been addressed and a review of conventional and potential alternative technologies has been made. Black liquor combustion properties and its combustion within a conventional recovery boiler, the principle of vortex combustion, and methods of computational fluid dynamics were summarized. In order to use the commercially available computational fluid dynamics package, PHOENICS, to simulate black liquor combustion in a vortex combustor, the black liquor combustion process was simplified and modelled and additional software programs were developed and attached to the commercial package. The developed module is capable of tracking trajectory paths of black liquor particles during combustion. A 250 kW vortex combustor was used for some experimental work. The combustor was first tested with natural gas and kerosene. The - combustion conditions were satisfied and their characteristics were presented. Atomization was the main technical problem in the combustion of black liquor. However, the environmental problem was also severe. The results were presented and discussed. Improvements of the system and further studied were suggested. Selection of a suitable turbulence model was made by comparing experimental data with the simulations from various turbulence models. Prandtl mixing length model gave closer predictions than k-? and k-1 model and therefore, it was used for the entire simulations. Simulations of natural gas combustion in a vortex combustor were made to establish skill and confidence in using the package, PHOENICS, to deal with combustion process. A series of black liquor combustion models were performed afterward using the particle tracking module developed. This led to the suggestion of a potential suitable geometry of a vortex combustor for black liquor incineration. The results were presented and discussed. Further simulation studies are also suggested.

This work has included a review of the most relevant aspects of measurement techniques and mathematical models proposed in the literature to assess the equilibrium and mass transfer data of metal extraction by the use of chelating agents. The limitations of these techniques and models have been highlighted. Three chelating extractants diluted in EscaidllO were used to study the extraction equilibrium of copper. The extractants are 5-nonylacetophenone oxime (LIX84®), 5- dodeylsalicylaldoxime (LIX860®) and 50/50 v/v mixture of both oximes (LIX984®). The copper concentration changes in the aqueous and the organic phases were monitored by using atomic absorption spectrophotometer. Two mathematical models (a chemical model and a semi-empirical model) have been developed in this study to predict the equilibrium data of copper sulfate/hydroxyoxime system. The chemical model was found to fit all the three equilibrium systems (CuSO4/LIX84®, LIX860®and LIX984®) equally. The semi-empirical model based on Freundlich's adsorption equation was also found to fit the three systems but with less accuracy. The mass transfer characteristics and properties of copper extraction and recovery from an aqueous solution using LIX984® were studied using dispersion-based (rising drops) and dispersion-free techniques. In the dispersion-based technique the organic phase was dispersed in form of drops at the tip of hypodermic needle while the aqueous solution was used as a continuous phase. The extraction process was carried out in four different height columns under wide range of conditions. The effects of the columns' height, the dispersed and the continuous phases concentrations on the metal rate of mass transfer were investigated. It has been found in that the metal's rate of mass transfer and system's overall mass transfer coefficient have remained constant in all four columns. A model utilising the two-film theory, some of the dimensionless groups and the experimental results has been proposed in this work to calculate the local mass transfer coefficients in the dispersed phase and the continuous phase. The overall mass transfer coefficient and the calculated local coefficients were used to account for the reaction rate constant at the interface from the sum of the individual resistances to mass transfer. A dispersion-free technique consisting of a microporous hollow fibre module was used in this study to examine the mass transfer properties of the extraction and stripping processes of copper across an immobilised interface system. The extraction and re-extraction (stripping) processes in this system were conducted under a wide range of operating conditions and produced satisfactory results. In general it has been found that counter current flow arrangement gave higher concentration driving forces which were reflected in form higher metal concentrations at the extract phase. A generalised mathematical model was developed in this study which utilised Wilson's method, the experimental data, some dimensionless groups and the two-film theory to account for local resistances and predict the system's overall mass transfer coefficient. A correlation was established first to calculate mass transfer coefficients using a form of Leveque's equation which relates the two phase's physical properties and the system's parameters. The membrane mass transfer coefficient was calculated from the structural properties of the membrane material. While the resistance at the reaction interface was calculated under set of experimental conditions. The individual coefficients were then used to predict the overall mass transfer coefficient under any set of conditions by using the aditivity approach of the individual resistances to mass transfer. However, further checks and investigations are necessary to validate this model over variety of extraction systems and membrane configurations.