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Green reinforcement in polymer systems have shown great promise in reducing cost, negative environmental effects, and dependency on nonrenewable resources. Both natural fillers and composite regrind can increase mechanical performance, while reducing new resin inputs for polymer based components. PVC and Polyurethane foam are widely used in North America in high volumes. Ground corn cob greatly increased the modulus of a flexible PVC system while minimally reducing maximum strength. The corn cob also showed signs of being a suitable filler in a polyurethane foam composite panel at low concentrations with minimal changes in mechanical performance. Polyurethane composite regrind illustrated great potential being used in new polyurethane composite panels with acceptable material properties. Replacing just a few percent of polyurethane and PVC with green reinforcement could reduce new production of these polymers by millions of pounds per year in North America alone.

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The research is concerned with· exploration of the utility of fractal methods for characterising the mixing treatment applied to a rubber compound and also for characterising the microstructure developed during mixing (filler dispersion). Fractal analysis is also used for characterisation of the fracture surfaces generated during tensile testing of vulcanised samples. For these purposes, Maximum Entropy Method and Box Counting Method are developed and they are applied to analyse the mixing treatment and the filler dispersion, respectively. These methods are effectively used and it is found that fractal dimensions of mixer-power-traces and fracture surfaces of vulcanised rubber decrease with the evolution of mixing time while the fractal dimension of the state-of-mix (filler dispersion) also decreases. The relationship of the fractal dimensions thus determined with conventional properties, such as viscosity, tensile strength and heat transfer coefficient are then explored For example, a series of thennal measurements are carried out during vulcanisation process and the data are analysed for determining the heat transfer coefficient Nuclear Magnetic Resonance is used to obtain the properties of bound rubber and a quantitative analysis is also carried out and possible mechanisms for the relationships between the parameters are discussed based on existing interpretations. Fmally, the utility of the fractal methods for establishing mixing-microstructureproperty relationships is compared with more conventional and well established methods. For this purpose, the fractal dimension of the state-of-mix is compared to conventional methods such as the Payne Effect, electrical conductivity and carbon black dispersion (ASTM D2663 Method C). It is found that the characterisation by the fractal concept agrees with the conclusions from these conventional methods. In addition, it becomes possible to interpret the relationships between these conventional methods with the help of the fractal concept.

Research has shown that children categorize words in terms of taxonomic and slot-filler strategies. Monolingual children were thought to shift from a slot-filler to taxonomic strategy between the age of five and eight. The aim of this study is to analyze the way Mandarin-English bilingual children organize their lexical-semantic system through the use of a category-generation task that investigate taxonomic and slot-filler organizational strategies in each language. There were 53 Mandarin-English bilingual participants (between 4 and 7 years of age) included in this study. Participants were asked to name as many items as they could think of in slot-filler and taxonomic conditions in English and Mandarin. The results indicate greater performance in English than Mandarin in children who were five years or older. Four-year-old bilingual children produced comparable number of items in both slot-fill and taxonomic condition, but the five-, six-, and seven-year-old bilingual children showed greater performance in the taxonomic condition. Children performed better for the animal than the clothes category, and better for the clothes than the food category. These findings, while largely consistent with existing literature, suggest that the slot-filler to taxonomic shift may take place at an earlier age compared to monolingual children. / text

Pour conférer au caoutchouc naturel de meilleures propriétés mécaniques, quand il s’agit d’applications industrielles spécifiques telles que le pneumatique, il est mélangé entre autres à des charges renforçantes. L’objectif de cette thèse est double : nous nous sommes premièrement intéressés à l’élaboration d’un nouveau type de charges hybrides, composées d’une partie minérale (silice) et organique (polymère). La stratégie que nous avons développée consiste à synthétiser des nanoparticules hybrides de morphologie contrôlée par polymérisation en émulsion ensemencée et à les agréger a posteriori. Nous avons également réalisé l’étude des propriétés mécaniques d’élastomères chargés avec les charges hybrides obtenues. / It’s necessary to use filler to give better mechanical properties to the natural rubber when it is used in the making of tires. The objective of this thesis is twofold: firstly we have developed a new type of fillers composed of mineral part (silica) and organic part (polymer). The strategy that we developed is to synthesize hybrid nanoparticles of controlled morphology by seeded emulsion polymerization and to aggregate them subsequently. The second objective was to study the mechanical properties of elastomers filled with the obtained hybrid entities.

<p>The aim of this study is to find out what effects the omission of intensifiers, interjections and fillers has on the general English subtitle track in the TV-series “The Wire”. Questions addressed in the study include the possible reasons for such omissions, and the consequences of applying omission strategies in this context. Thirteen episodes of the series were investigated in order to see to what extent these three types of words were omitted, and how that affected the experience when watching the series. The investigation showed that the majority of all omitted words in the subtitle track belonged to these three categories, and that technical restrictions were the most common reason for the omissions. Arguably, the lack of intensifiers, interjections and fillers made the language more stiff and formal, which in the end affected the authenticity of “The Wire”.</p>

The aim of this study is to find out what effects the omission of intensifiers, interjections and fillers has on the general English subtitle track in the TV-series “The Wire”. Questions addressed in the study include the possible reasons for such omissions, and the consequences of applying omission strategies in this context. Thirteen episodes of the series were investigated in order to see to what extent these three types of words were omitted, and how that affected the experience when watching the series. The investigation showed that the majority of all omitted words in the subtitle track belonged to these three categories, and that technical restrictions were the most common reason for the omissions. Arguably, the lack of intensifiers, interjections and fillers made the language more stiff and formal, which in the end affected the authenticity of “The Wire”.

Polypropylene (PP) composites includ a mineral filler, though they can be enhanced by blending with an elastomer. Blending rigid fillers with PP increased strength while decreasing toughness. Blending soft elastomers with PP decreased strength while increasing toughness. PP-elastomer-filler ternary composites offer synergism because the increase of strength due to filler may compensate the loss of strength due to the elastomer. Two morphologies were identified, separated elastomer and filler particles in PP, and filler particles encapsulated by elastomer in PP. Interaction between filler and PP matrix are proposed to increase with the addition of polar elastomers when encapsulated morphology is formed, leading to enhanced mechanical properties. PP-elastomer-filler blended tapes were prepared via single-screw extrusion. Annealing was performed after cooling the tapes, and this combination proved to increase the modulus. Characterization of the composites was carri ed out using thermogravimetry, dynamic-force thermomechanometry, modulated-force thermomechanometry, and Fourier transform infrared imaging. Incorporation of polysiloxane elastomer increased the mobility of PP during extrusion. Elongation at break increased with increasing polysiloxane content, while the tensile modulus was slightly decreased. The silica core within the polysiloxane particles provided an additional strength enhancement. Polar elastomers aided binding between PP and fillers, while enhancing strength and toughness. Glass transition temperature and segmental motion activation energy was shifted to higher temperature with addition of elastomer and filler, including kaolin and talc.