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The application of Strumpel's behavioral economic model to explain financial behaviorToccafondi, Toni L. 24 October 2009 (has links)
The purpose of this study was to apply Strumpel's behavioral economic model to explain personal financial behavior. Three categories of variables as identified by the model determined the independent variables in the study. These variable groups were defined as the objective environment consisting of financial life cycle stage, income, education, occupation, ethnicity, and gender; person dimensions including self-esteem, money self-esteem, and locus of control; and dimensions of subjective well-being represented by perceived income adequacy and satisfaction with financial situation. Three research questions were explored in the study: ( a) Can personal financial behavior be explained by the objective environment; (b) Can personal financial behavior be explained by person dimensions; and (c) Can personal financial behavior be explained by subjective well-being?
The respondents were from a pre-collected data set entitled Financial Attitudes and Practices of Virginia Citizens (N = 521). Factor analysis was utilized to statistically determine appropriate groups of financial behaviors, from 23 behavior items in the study, to selVe as the dependent variables. Conceptually, these behavior factors were determined to represent credit use behaviors, financial planning behaviors, financial management behaviors, and financial control behaviors. Multiple regression was the primary statistical procedure used in the analysis.
The combination of independent variables explained 36% (p<.OO1) of the variance in credit use behavior, 41 % (p<.OO1) of the variance in financial planning behavior, 15% (p<.001) of the variance in financial management behavior, and 9% (p<.01) of the variance in financial control behavior. The subjective well-being variables significantly contributed to the explanation of the variance in two behavior dimensions. Measures of self-esteem and locus of control were significant predictors of three of the four behavior dimensions. Objective environment variables also accounted for significant portions of the variance in the dependent variables. Findings suggested that the objective environment, subjective well-being, and person dimensions help explain financial management behavior. The results of this study did provide evidence to support further application of Strumpel's model as a guide to explain financial management behavior. / Master of Science
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Methionine: oxidation state in processed foods and enzyme-catalyzed reaction with adenosine triphosphateTodd, Jeanne Marie January 1980 (has links)
Two conditions of alkaline hydrolysis of proteins, (1) 2M NaOH, 18 hours, 100°C and (2) 3M NaOH, 16 hours 110°C, prior to ion-exchange chromatography were tested on free amino acids and model protein systems to determine the better set of conditions for measurement of methionine sulfoxide in food proteins. Recoveries of methionine, methionine sulfoxide, and methionine sulfone from base-hydrolyzed amino acid mixtures were, respectively, 89, 100, and 105% with the 2M NaOH conditions and 83, 90, and 98% with the 3M NaOH conditions. The percentages of total methionine, determined by performic acid oxidation, recovered as methionine, methionine sulfoxide, and methionine sulfone after hydrolysis with 2M NaOH were, respectively 101, 0, and 0% in lysozyme, 68, 25, and 0% in oxidized lysozyme, 74, 3, and 0% in casein and 0, 74, and 0% in oxidized casein. The presence of glucose in the hydrolysis mixture with the model proteins caused as much as 8% oxidation of methionine to methionine sulfoxide. The presence of copper (II) and iron (II) ions along with sugars did not increase the amount of methionine generated in casein and a soy isolate. Methionine sulfone was never generated in any of the model systems. These results suggested that determination of methionine sulfoxide after basic hydrolysis with 2M NaOH in foods low in carbohydrates is valid but in foods high in carbohydrates the procedure may slightly overestimate the methionine sulfoxide content.
Acid hydrolysis of free methionine sulfoxide reduced 15% of the methionine sulfoxide to methionine while acid hydrolysis of oxidized lysozyme and oxidized casein led to reduction of all the methionine sulfoxide in these proteins.
Eight food products were analyzed for methionine, methionine sulfoxide, and methionine sulfone. Total methionine was measured by the performic acid oxidation method, methionine sulfone by ion-exchange chromatography after acid hydrolysis, methionine sulfoxide by ion-exchange chromatography after hydrolysis with 2M NaOH for 18 hours at 100°C, and methionine by the difference between total methionine and the sum of methionine sulfoxide and sulfone. Only a trace of methionine sulfone and less than 6% of total methionine was present as methionine sulfoxide in a soy flour and a concentrate. Two soy isolates contained 74 and 8% of total methionine as sulfoxide and 6 and 4%, respectively, as sulfone. Two soy-based infant formulas contained 17 and 12% of total methionine as the sulfoxide and 12 and 8%, respectively, as sulfone. Two milk-based formulas contained 18 and 9% as sulfoxide and 8 and 13%, respectively, as sulfone.
The feasibility of using ATP:L-methionine S-adenosyltransferase to determine the number of unaltered methionine residues in food proteins was also explored. Di- and tripeptides composed of methionine appeared to be able to function as well as L-methionine as substrates. Spectrophotometric studies suggested that the enzyme could act on methionine residues in two soy isolates; however, these results could not be confirmed by amino acid analyses of the isolates after incubation with ATP and the enzyme. / Ph. D.
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Cure studies of network-forming polyurethanesToffey, Ackah 12 March 2009 (has links)
The polyhydroxy character of lignocellulosics and their natural abundance make them good candidates for the manufacture of polyurethanes.
The cure characteristics of hydroxypropyl-cellulose and hydroxypropyl lignin (HPC and HPL, respectively) with polymeric methylene diphenyl diisocyanate (MDI) was studied via dynamic mechanical thermal analysis (DMTA).
HPC/MDI and HPL/MDI resins flow at 30°C and proceed to cure at 50°C. The latter has excellent thermal stability over the former. Crosslinking of HPL and HPC with MDI follow an nth order kinetics, with an order of reaction of 2 and an apparent activation energy in the range of 12.9 kcal/mol - 14.7 kcal/mol.
The rate of cure with time is higher in HPL-based polymers than HPC-based ones at the initial stage of cure; the difference vanishes at later stages. This demonstrates that the hydroxyl groups in HPC are less accessible to the NCO groups, and that cure rate might be dependent on diffusion limitations at later stages.
Degree of cure, under all cure schedules, follows a parallel trend, and has to do with the fact that the hydroxyl groups of HPC are less accessible to isocyanate. Both HPL and HPC react with MDI at a reduced rate in comparison to a synthetic polyol: caprolactone triol.
Time-glass transition temperature superposition was used to calculate times to vitrification of the HPL-based polymers, and is presented in a TTT cure diagram. This bio-based polymer displays the s-shaped vitrification pattern characteristics of thermosets. A similar approach did not work with HPC-based polymers. HPC- and HPL-based polymers did not display damping transitions, in isothermal cure, typical of gelation and vitrification. As the isocyanate to hydroxyl ratio (NCO:OH) increased, the glass transition temperature of the polymers increased, and the transition amplitude and width decreased and increased, respectively.
In practical terms, this study illustrates that it is advantageous to use
a) to use high isocyanate to hydroxyl ratios in order to produce polyurethanes which retain desirable damping behavior over a wider range of temperature.
b) to use HPC/MDI resins in those situations where retention of stiffness at temperatures below 230° is required.
c) to use HPL where rapid cure is desired.
The study also reveals that the relative reactivity of water, HPL and HPC with isocyanate takes the form water > HPL > HPC. / Master of Science
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Structure-property relationships of novel cellulose estersTodd, Jason G. 10 July 2009 (has links)
Cellulose “waxy” (long-chain aliphatic) tri-esters of lauric (C₁₂), myristic (C₁₄), stearic (C₁₈), and eicosanoic (C₂₀) acids; mixed esters of lauric and acetic acids; and fluorinated mixed esters of 2,2,2-trifluoroethoxyacetic (TFEA) and acetic acids were synthesized in homogeneous DMAc/LiCl solution. Degree of substitution (DS) was conveniently controlled via stoichiometry, and fully-substituted cellulose derivatives were produced with little depolymerization. Thermal analysis of the C₁₂ - C₁₄ waxy tri-esters revealed separate melting transitions (T<sub>m,L</sub> and T<sub>m, H</sub>) for ester substituents and main cellulose chains, providing evidence for the existence of a separate (crystalline) phase formed by the ester substituents. Main-chain T<sub>mS</sub> of waxy esters converged with the melting transition of the side-chain phase and/or disappeared as substituent length reached C₁₈. The effectiveness of melting point depression at low DS of large substituents increased with increasing substituent length for n-alkyl substituents up to lauryl (C₁₂); at mid-DS of large substituent, increasing the substituent length had no further effect in melting point depression above a length of C₆ (hexanoyl). The preferential sorption of ethanol from aqueous solution by cellulose (CE) and cellulose acetate trifluoroethoxyacetate (CATA) of varying DS was measured by liquid chromatography (LC); the preferential sorption of ethanol did not change when acetate substituents were replaced by trifluoroethoxyacetate substituents. The preferential sorption of ethanol by unmodified cellulose was stronger than the preferential sorption by cellulose acetate and trifluoroethoxyacetate esters. / Master of Science
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A comparison of judgments respecting the worth of various occupations made by seniors and freshmen at a teachers' collegeTodd, Mary Younger January 1953 (has links)
One of the main purposes of the study, then, became that of estimating the degree of change which may be expected, with regard to attitudes concerning occupations, during a four-year period of college experiences. In order to carry out that purpose, an investigation was made of the occupational attitudes held by Seniors and Freshmen at Radford College, in order to observe whatever differences might exist between the judgments of the two groups. The fact that most of the subject groups were preparing for work in a professional field was taken into consideration where preference was shown for occupation of a professional nature. / M.S.
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An Axis Through Nature: Ranger Station at Pandapas PondTodd, Alan Curry 08 May 2007 (has links)
My thesis is a human intervention into the tranquil and natural environment of Pandapas Pond and the Jefferson National Forest. Although the form of the intervention embraces the landscape and natural land formations, its purpose is to take the visitor along a path that translates the experience from one of participation to that of observation of the parkâ s surroundings. This is both an investigation of an architectural integration with the site and a partial separation of the inhabiter from his/her natural surroundings. / Master of Architecture
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