Rigid polyurethane foam is a polymeric material which is widely used for thermal insulation in building construction and other applications. Given recent emphasis on energy conservation and efficiency, there has been continuous growth in its use over the years. This raises significant fire safety concerns since polyurethanes are inherently very flammable and prone to release toxic gases as the foam thermally decomposes and burns. To improve fire safety characteristics by reducing ignitability and flammability of the foams, various flame retardants (FR) have been introduced into base foam formulations. But with the introduction of FR agents, there has been rising concern within the fire safety community and general public regarding the overall benefits versus detrimental impacts of even commonly used FR agents. In the case of rigid polyurethane foam, however, such an assessment is difficult as there are few cross comparisons in the literature that detail the impacts of different concentrations of common fire retardants, such as brominated, phosphorus-based and expandable graphite agents, on the fire behavior, smoke development and toxic gas production for even single base foam formulations. The present experimental work focuses on a systematic evaluation of these factors using three common, commercial fire retardants added in concentrations of 0%wt, 10%wt and 20%wt to a single formulation of rigid polyurethane foam. Cone calorimeter and smoke density tests are used to simulate well ventilated and poorly ventilated fire conditions during material fire performance assessment, while FTIR, Novatech P 695 gas analyzers and TD-GC/MS methods are used to investigate the gases evolved during oxidative pyrolysis and combustion of the samples. Concentration measurements of principal fire gases such as CO, CO2, reduced O2, and NOx are combined with more detailed investigation of the volatile organic compounds generated during the fire testing. Use of gas absorption sampling followed by off-line Thermal Desorption/Gas Chromatography/Mass Spectrometry (TD-GC-MS) analysis for identification of toxic gases has proven of significant benefit in this application. The full set of data obtained provides a more comprehensive identification of the evolved products during three characteristic periods in the combustion process. As such, it expands current knowledge and provides valuable new insight and understanding of thermal degradation, combustion and smoke development, as well as overall fire performance, of fire retarded rigid polyurethane foams in well-ventilated and poorly ventilated environments.

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The imaginary part of the retarded self energy is of particular interest as it contains a lot of physical information about particle interactions. In higher order loop diagrams the calculation become extremely tedious and if we have to do the same at finite temperature, it includes an extra dimension to the difficulty. In such a condition we require to switch between bases and select the best basis for a particular diagram. We have shown in our calculation that in higher order loop diagrams, at finite temperature, the R/A basis is most convenient on summing over the internal vertices and very efficient on calculating some particular diagrams while the result is most easily interpretable in the Keldysh basis for most other complex diagrams. / February 2010

The imaginary part of the retarded self energy is of particular interest as it contains a lot of physical information about particle interactions. In higher order loop diagrams the calculation become extremely tedious and if we have to do the same at finite temperature, it includes an extra dimension to the difficulty. In such a condition we require to switch between bases and select the best basis for a particular diagram. We have shown in our calculation that in higher order loop diagrams, at #12;finite temperature, the R/A basis is most convenient on summing over the internal vertices and very efficient on calculating some particular diagrams while the result is most easily interpretable in the Keldysh basis for most other complex diagrams.

The purpose of this study was to examine whether or not Public Service Announcements (PSAs) were an effective tool at modifying young adults’ perception of the r-word (the word “retard” or “retarded”). The PSAs included in this study were part of the Special Olympics’ “Spread the Word to End the Word” campaign. This study examined the efficacy of these PSAs by comparing three groups’ perception of the r-word: experimental group 1 who watched a PSA titled “It’s Not Acceptable” (PSA 1 group), experimental group 2 who watched a PSA titled “We Need a New R-word” (PSA 2 group), and a third control group who watched no PSA. The purpose of the control group was to gain a baseline of how today’s young adults perceived the r-word with no influence from PSAs. Six hundred and seventy-five participants were randomly assigned to one of the three groups. The two experimental groups watched their respective PSAs and completed the survey materials comprised of a consent form, their affective and cognitive responses to the PSA, their ratings of the r-word and their demographic information. The control group watched no PSA but completed the survey materials comprised of a consent form, their ratings of the r-word and their demographic information. This study then examined what the differences were between the three groups’ perception of the r-word. It was hypothesized that PSA 1 group would have a more negative perception of the r-word than PSA 2 group and the control group, due to PSA 1’s framing the r-word as similar to other minority slurs, and using affect to facilitate message acceptance. The PSA 1 group participants thought more about the argument within their PSA, and rated higher affective responses to their PSA, when compared to the PSA 2 group; however, PSA 1 group did not have a more negative perception of the r-word than the other two groups. Results found that the PSA 2 group perceived the r-word as significantly less respectful than the participants in the control group. These findings are discussed in terms of message design for future PSAs regarding the r-word

The comparability of PPVT and PPVT-R scores among retarded adults were examined. The sample consisted of 96 clients, who had been previously diagnosed as mildly, moderately, or severely retarded. The PPVT (Form A) and PPVT-R (Form L) were administered to all participants in counter balanced order. Significant correlations were found between the two tests for the total sample as well as for females and males. Additionally, the PPVT-R was found to be capable of discriminating differing levels or retardation. However, with the exception of the severely retarded group, mean PPVT-R Standard Score Equivalent (SSE) scores tended to be approximately 20 points lower than PPVT IQ scores. Some clinical implications of these results were discussed.

The present study had three purposes. The first was to determine which of seven variables were significantly correlated with improvement in reading in a representative sample of elementary school children who had received remedial reading instruction. The second was to ascertain whether these variables could be used in developing an equation for predicting improvement that would be simple and quick enough to be of practical value in the remedial clinic. The final purpose was to determine whether the relationship between intelligence and reading improvement was the same over three different intelligence ranges.

The problem of this study was to evaluate Denton State School's Developmental Evaluation Form as it is now being used in their operant conditioning techniques in certain basic self-help areas, and to suggest a more effective and informative method of scoring the Evaluation Form. The present method of scoring this evaluation form requires that -all items at each developmental level be passed in order to receive credit for that level. No partial credit is given at any level. This method of scoring yields a developmental level at which. the individual is functioning. It does not, however, point out the total overall development of the individual. The present type of basal developmental scoring is not as discriminating as far as picturing an individual's total development as the one which will be suggested.

This thesis is concerned with the study of transient scattering of acoustic waves by an obstacle in an infinite domain, where the scattered wave is represented in terms of time domain boundary layer potentials. The problem of finding the unknown solution of the scattering problem is thus reduced to the problem of finding the unknown density of the time domain boundary layer operators on the obstacle’s boundary, subject to the boundary data of the known incident wave. Using a Galerkin approach, the unknown density is replaced by a piecewise polynomial approximation, the coefficients of which can be found by solving a linear system. The entries of the system matrix of this linear system involve, for the case of a two dimensional scattering problem, integrals over four dimensional space-time manifolds. An accurate computation of these integrals is crucial for the stability of this method. Using piecewise polynomials of low order, the two temporal integrals can be evaluated analytically, leading to kernel functions for the spatial integrals with complicated domains of piecewise support. These spatial kernel functions are generalised into a class of admissible kernel functions. A quadrature scheme for the approximation of the two dimensional spatial integrals with admissible kernel functions is presented and proven to converge exponentially by using the theory of countably normed spaces. A priori error estimates for the Galerkin approximation scheme are recalled, enhanced and discussed. In particular, the scattered wave’s energy is studied as an alternative error measure. The numerical schemes are presented in such a way that allows the use of non-uniform meshes in space and time, in order to be used with adaptive methods that are based on a posteriori error indicators and which modify the computational domain according to the values of these error indicators. The theoretical analysis of these schemes demands the study of generalised mapping properties of time domain boundary layer potentials and integral operators, analogously to the well known results for elliptic problems. These mapping properties are shown for both two and three space dimensions. Using the generalised mapping properties, three types of a posteriori error estimators are adopted from the literature on elliptic problems and studied within the context of the two dimensional transient problem. Some comments on the three dimensional case are also given. Advantages and disadvantages of each of these a posteriori error estimates are discussed and compared to the a priori error estimates. The thesis concludes with the presentation of two adaptive schemes for the two dimensional scattering problem and some corresponding numerical experiments.

Utilization of renewable energy sources, as an approach to reduce greenhouse gas (GHG) emissions, have been globally popular in the last few decades. Among renewable energy sources, pressure retarded osmosis (PRO) has been scrutinized by scientists since the mid 70's. However, even today, the existing river-sea PRO systems can only marginally meet the generally approved criterion of 5 W/m2 power density, a threshold for an economically feasible PRO system. As an approach to increase the performance of PRO systems, multi-staging of PRO modules are investigated. A mathematical model of the scaled up PRO process is proposed with consideration for internal and external concentration polarization, reverse salt flux, and spatial variations along the membrane. A thermodynamic model is also developed with consideration for entropy generation and losses in the process. It predicts the percentile of each work loss source compared to the net work in the system. Several confi gurations of dual stage PRO system are presented and compared to single stage PRO. The comparison is based on three proposed target functions of power density (PD), specifi c energy (SE), and work per drawn freshwater (Wdrawn). Applied hydraulic pressures and flow rates of draw and feed solutions are optimized for maximizing the target functions. The results indicate that overall performance of the system could be improved by up to 8 % with a dual stage PRO in the case of SE. The system performance is not improved by depressurizing the draw solution before the second module in cases of SE and Wdrawn. The thermodynamic analysis demonstrate the contribution of each work loss and justify the reason of diminishing the net work over the losses. The effect of membrane area and membrane characteristics on the SE target function is also investigated. The distribution of membrane area in each module depends on the selected con figuration and inlet draw solution. In the dual stage systems, the SE value increases up to 14% by improving the membrane characteristics. Reducing the salt rejection coefficient (B) is the most e ective membrane characteristic in our con figurations. Replacing seawater with RO brine in draw solution results in a signifi cant improvement in SE values. / Graduate