<p> During the combustion of carbonaceous fuels under rich conditions, incomplete combustion will lead to a fraction of fuel&rsquo;s carbon being converted into carbonaceous particulate known as soot. The particle inception process is believed to occur at the transition from gas-phase to solid-phase species and is known to involve polyaromatic hydrocarbons (PAH). While parts of the soot formation mechanism are well-understood, this particle inception process lacks the same level of experimental rigor. A combination of in situ and ex situ optical spectroscopy methods have allowed us to fill this experimental void. Tauc/Davis-Mott analysis using a supercontinuum light source was used to map out the experimentally determined optical band gap through a range of laminar diffusion flames including both gas and liquid phase fuels. The average optical band gap observed across all of the flames was 2.06 &plusmn;0.03eV. Semi-empirical (ZINDO/S) and quantum mechanical (DFT) computations were performed to relate the experimentally determined optical band gap to the HOMO-LUMO gap in a variety of PAH. The average PAH sizes in these flame systems corresponded to structures of 11 &plusmn; 4 rings and conjugation lengths between 0.85 &plusmn; 0.11 nm. Raman spectroscopy of thermophoretically sampled soot supported these results concluded finding a consistent conjugation length of 0.86 &plusmn; 0.10 nm was observed throughout the entire flame system . FTIR spectroscopy of thermophoretically sampled soot in the same flame system found the prevalence of both aromatic and aliphatic compounds throughout the entire flame, but was not able to conclude the nature of the aliphatic species. The conclusions from this work indicate that the particle inception occurs with structures about the size of ovalene and this size seems to be consistent across of a variety of fuels and sooting levels. Additionally, the consistency of conjugation lengths and optical band gaps determined throughout the flame systems, with increasing soot volume fractions indicates that further mass growth of the soot particulates occurs through aggregation processes.</p>

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Physical Therapy.

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy [Physical Therapy].

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy [Physical Therapy].

Purpose: To investigate the incidence of urinary incontinence (UI) and relationship between UI and health related quality of life (HRQOL) of postpartum Bangladeshi women. Problem Statement: There are no studies comparing HRQOL with incidence and impact of UI amongst Bangladeshi women who have had cesarean section (CS) and those with normal vaginal delivery (NVD). Methods: Prospective, cross sectional, correlational design (n=94) of postpartum Bangladeshi women, ages 18-44, with history of one or more obstetrical deliveries within the last three years. Implemented at the Center for Rehabilitation of the Paralyzed (CRP) in Bangladesh. Subjects completed the Bengali version of the SF-36 and IIQ-7. Results: Six subjects were eliminated from the study because of co-morbidity exclusion factors. Eight subjects were excluded secondary to "mixed birth mode" (MBM). UI incidence was reported at 45% (n=39/86) total, 44% CS (n=18/41), and 47% (n=21/45) for NVD. IIQ-7 scores and UI presence showed strong correlations in both CS (rho=.729, 84, p<.001) and NVD (rho=.874, 84, p<.001). The highest impact of UI was reported in the CS group. One sample t-test reported significant differences for the sample when compared with the age equivalent norms for the SF-36 domain and component scores (p =.05-.001). Women in the 35-44 age group reported higher UI incidence and decreased HRQOL scores on the SF-36 and IIQ-7. Significant differences in HRQOL were reported for women with "pelvic/abdominal pain" and "UI" compared to those without "pain" or without "UI" and strong inverse correlations (rho=.597-.853) were reported for subjects with "pain" on the SF-36 domains (p=.001). The MBD group (n=8) reported UI incidence at 74% (n= 6/8), and pelvic/abdominal pain at 63% (n=5/8). Conclusion: No significant difference between birth modes was found in UI and HRQOL measures. A significant decrease in HRQOL for women during the postpartum period compared to age related norm scores was reported. Report of abdominal/pelvic pain and presence of UI were directly related to HRQOL in this study. Future research in this population should address pelvic and abdominal pain and "mixed birth mode" impact on QOL and UI in a larger sample using a longitudinal design.

Strengthening exercises for the lumbar extensor musculature represent the most common form of exercise therapy employed by physical therapists in clinical management of adults with chronic low back pain (CLBP). Despite the popularity of lumbar extensor strengthening exercises, the dose response relationship for lumbar extensor strengthening exercise in the clinical management of CLBP is not well established and specific guidelines to assist physical therapists in the prescription of lumbar extensor strengthening exercises for this population have not been fully developed. The primary aim of this investigation was to contribute to the understanding of the dose response relationship for lumbar extensor strengthening exercise in the clinical management of adults with CLBP. This objective was achieved by conducting a retrospective analysis of medical records from a cohort of adults with CLBP who completed a structured protocol of physical therapist supervised lumbar extensor strengthening exercises over a 5 year period at a hospital based outpatient rehabilitation center. After controlling for heterogeneity in baseline demographic and clinical characteristics, the results of the statistical analysis procedures suggested that performance of the exercise protocol once weekly for 12 weeks was associated with clinically meaningful improvements in pain intensity, perceived disability, and lumbar extensor function. There was insufficient evidence to conclude that higher training frequencies were necessarily associated with better clinical outcomes. The adults with CLBP most likely to benefit from the structured protocol of lumbar extensor strengthening exercises were those individuals who demonstrated the greatest deficits in lumbar extensor function during their baseline performance testing procedures.

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy [Physical Therapy].

A formal dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy [Physical Therapy].

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy [Physical Therapy].

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy.