Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

The aim of this study was to compare the incidence of root canal dentinal micro-cracks after canal instrumentation using reciprocating files (WaveOne Gold® and Twisted Adaptive®) and continuous rotation files (Edge Evolve® and EndoSequence®) in an ex-vivo benchtop study. This project used a novel methodology of finding dentinal defects using the “K-cube”, which allows evaluators to visualize sectioned root surfaces before instrumentation and after instrumentation. Mesial roots from 40 human mandibular first molars were divided into 4 groups of 10 for each file type. Root section pictures were taken with a Zeiss Discovery V20 stereomicroscope before and after canal instrumentation. Each of the pre-instrumentation and post-instrumentation images were evaluated for dentinal defects by four calibrated endodontists utilizing REDCap survey. Using a chi-square analysis, there was no statistically significant difference between dentinal defects created by continuous and reciprocating rotation (p=0.1924) and no difference between the four file types (p=0.2317).

Anthropogenic climate change is arguably the greatest challenge of modern times posing significant risks to natural resources and the environment. Socio-economic change, severe droughts, and environmental concerns focus attention upon sustainability of water supplies and the ability of water utilities to meet competing demands worldwide. The 2012 Climate Change Risk Assessment identified water security as one of the most significant climate threats facing the UK. It is now recognised that household water demand management could offer a low regret adaptation measure (both financially and environmentally) given large uncertainties about future climate and non-climatic pressures. This thesis uses Anglian Water Services (AWS) Golden 100 dataset to explore the climate sensitivity of historic micro-component water-use. This work contributes to a larger integrated assessment of the South-East England water system under the EPSRC Adaptation and Resilience to a Changing Climate Coordination Network (ARCC CN). The Golden 100 is a metered record of 100 households daily water consumption by basin, bath, dishwasher, external, kitchen sink, shower, WC and washing machine use. The archive also includes socio-economic information for each household, dates of the year and daily time series of observed minimum temperature, maximum temperature, sunshine hours, soil moisture deficit, concurrent, and antecedent rainfall amounts. The methodology developed within this research provides a portable approach to error trapping, formatting and mining large, complex water sector datasets, for exploring the relative sensitivities of micro-component metered water-use to weather/non-weather variables. This research recognises both the importance of the choice to use a micro-component and the volume used. As such, logistic and linear generalised regression techniques are employed to explore the relative sensitivity of these two aspects of water-use to climatic and non-climatic variables. The 2009 UK Climate Projections (UKCP09) projections and climate analogues are then used to bound a climate sensitivity analysis of the most weather-sensitive micro-components using temperature and rainfall scenarios for the 2050s and 2080s. This research provides empirical evidence that the most weather sensitive micro-components are external and shower water-use. A key contribution of this research to existing knowledge is the non-linear response of likelihood and volume of external water-use to average air temperatures. There is an abrupt increase in the likelihood of external water-use on days above ~15??C. Climate sensitivity analysis further suggests that by the 2080s, under a hotter/drier climate, average unmetered households could be 8% more likely to use external-water and expend ~9 litres more per day during the summer. For the same parameters, high water users (defined here as the 90th percentile) could consume ~13 litres more external water per day. Importantly, this research has re-affirmed the relative importance of behavioural drivers of water-use as manifested by pronounced day of week and bank holiday signatures in both the likelihood and volume of use statistics. As such, this prompts future studies and water management efforts to consider the impact of behavioural drivers as well as climate. It must be recognised that the small sample size of the Golden 100 combined with the Hawthorn effect, self-selection and sample biases in factors such as socio-economic status, billing method and occupancy rate all limit the sample representativeness of the wider population. As such, any predictions based on the data must be treated as illustrative rather than definitive. Furthermore, the results are probably specific to the demographic and socio-economic groups comprising the sample. Nonetheless, this research sheds new light into water-use within the home thereby adding value to a dataset that was not originally collected with household-level, weather-related research in mind.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

La famille des résines alkydes occupe une place prépondérante dans l'industrie des peintures et vernis. Leur élaboration s'effectue en milieu fondu à des températures supérieures à 180°C. Puis ces résines sont émulsionnées dans l'eau en présence de pigments, charges et de tensioactifs. L'objectif de cette thèse est d'effectuer la synthèse de ces alkydes à partir de monomères d'origine naturelle par polyestérification directement en émulsion dans l'eau et sous activation micro-ondes pour des gains de temps et d'énergie. La synthèse de ces alkydes a été réalisée tout d'abord en masse sous chauffage conventionnel, en utilisant des monomères issus principalement de la chimie verte. Puis les comportements énergétiques des émulsions de type huile/eau ou eau/huile ainsi que des solutions ioniques et micellaires ont été étudiés, permettant ainsi de comprendre la contribution de chacun des ses constituants. Avant d'effectuer la polyestérification des alkydes en émulsion dans l'eau, une étude modèle a été réalisée sous chauffage diélectrique MO en utilisant deux monomères de nature hydrophobes. Par comparaison avec le chauffage conventionnel, des polymères de masses molaires plus fortes sont obtenus en un temps plus court. La transposition de ce type de synthèse aux alkydes en utilisant deux principales voies de synthèses, en une seule ou deux étapes, nous a permis de sélectionner les bons tensioactifs permettant de maintenir des émulsions (huile /eau) stables à des températures allant jusqu'à 230°C. Cependant cette synthèse n'a abouti qu'à la formation d'un polymère de masse molaire de 3000 g/mole ce qui reste très faible par rapport à la synthèse en milieu fondu. Ceci est la conséquence directe de la compétition entre la réaction d'hydrolyse et la réaction de polyestérification. L'étude de la réaction d'hydrolyse des triglycérides provenant de l'huile de tournesol conduite en émulsion dans l'eau (eau/huile et huile/eau ) sous activation MO, montre une accélération de la réaction et par conséquent tout l'intérêt d'utiliser une activation micro-ondes / Alkyd resins are amongst the most important and widely used resins in coating sectors. Their preparation is carried out in bulk at elevated temperatures (˃180 ° C). These resins are then emulsified in water in the presence of pigments, fillers and surfactants. The objective of this thesis is to synthesis these alkyds directly in aqueous emulsion under microwaves activation to accelerate polyestrification reaction. The synthesis of these alkyds was performed in a molten state under conventional heating using monomers mainly from green chemistry. Then the energy behavior of emulsions, ionic and micellar solutions were studied, allowing understanding the contribution of each of their constituents. Before performing the polyesterification of alkyd emulsion in water, the polyesterification of hydrophobic compounds in aqueous emulsion was carried out under dielectric heating MO. Compared with conventional heating, polymers with molar masses higher are obtained in a shorter time. The transposition of this type of synthesis with Alkyd using two main synthetic routes, in one or two steps, we were able to select the surfactants to maintain emulsions (oil/water) stable at temperatures up to 230 °C. However, this synthesis led to the formation of polymer molar mass of 3000 g / mol, which is very low compared to the synthesis in the bulk conditions. This is a direct consequence of the competition between hydrolysis reaction and polyesterification reaction. The triglycerides hydrolysis study from sunflower oil in aqueous emulsion (water / oil and oil/water) under MO activation shows an acceleration of the reaction

L‟application du plan d‟ajustement structurel par la Banque Mondiale et le Fonds Monétaire International (FMI) dans la dernière décennie n‟a pas épargné les pays en voie de développement notamment ceux de l‟Afrique du Sud Sahara comme la Côte d‟Ivoire. Ainsi, certains pays vont connaître le phénomène de l‟exode rural vers les grands centres urbains, créant un surpeuplement des villes, une chute du niveau de vie, un chômage avec pour corollaire la pauvreté. L‟évolution de ce phénomène en Côte d‟Ivoire accentué par les différentes crises socio politique qu‟à connu le pays nous permet de retenir que la paupérisation demeure un fait préoccupant. Dans un tel cas, notons que la crise pétrolière dans les années 70, la crise économique des années 80 avec ses plans d‟ajustement structurel successifs, ainsi que la dévaluation du franc CFA dans les pays du tiers monde complique d‟avantage la situation des ménages. Cette réalité existante dans les zones rurales est accentuée dans les zones urbaines. Les principales victimes étant les jeunes et les femmes. En effet, ces dernières se trouvent confrontées à des problèmes d‟exclusion, de mise à distance avec un réel problème d‟accès aux ressources. La micro finance, notamment en Côte d‟Ivoire, se veut une alternative en procurant aux femmes pauvres, un droit au crédit afin de se constituer une épargne et investir dans des activités génératrices de revenus. Autant d‟avantage qu‟il convient nous le pensons de mesurer en terme d‟empowerment. Un gain de pouvoir qui pourrait leur permettre d‟être autonome et lutter contre la pauvreté féminine. / The application of structural adjustment by the World Bank and by the International Monetary Fund (IMF) in the last decade has not spared the developing countries including those in Sub-Saharan Africa like the Ivory Coast. Thus, some countries will experience the phenomenon of rural exodus to urban centers, creating an urban overcrowding, falling living standards and unemployment with the consequent poverty. The evolution of this phenomenon in the Ivory Coast accentuated by the various socio-political crises already known by the country allows us to retain that poverty remains a worrying fact. In those cases, the oil crisis of the 70s, the economic crisis of the 80s with its successive structural adjustment programs, and the CFA franc devaluation in the Third World have further complicated households situation. This reality in rural areas has increased in urban areas. The main victims are the young and women. Indeed, the latter are faces with problems of exclusion, distancing with a real problem of access to resources. Microcredit, particularly in the Ivory Coast, is an alternative by giving poor women a right to credit in order to accumulate savings and invest in activities generating income. We should think of the many advantages in terms of empowerment. A gain of power that could allow them to be independent and to fight against women‟s poverty.

Doctor of Philosophy / Department of Human Nutrition / Mark D. Haub / Little is known about the impact of dietary fiber (DF) on children. Current recommendations are based on extrapolations from adult studies. Research is needed to provide science based evidence to determine how DF impacts the gut of children. Two studies were conducted to investigate the interactions of DF in the child large intestine. In the first study, the dose response of DF on breath hydrogen, methane, and total hydrogen content was investigated relative to Institute of Medicine (IOM) recommended intakes in free-living preschool children. Only four of the 18 participants were able to comply with the treatment protocol. Although, no significant differences were noted in breath measures of fermentation across fiber consumption levels, there was a numerical pattern for increasing levels of DF to evolved increased gas production in the four compliers. In free-living individuals measures of acute fiber fermentation through breath was not sensitive enough over 6 hours to distinguish a difference in fermentative rate. Children, parents, and child care centers found this approach apparently acceptable. In study two, the impact of DF (10 g) fed over three weeks in children and their parents on metabolic markers of fermentation were evaluated. The body was able to adapt to 10 g/day DF consumption as bloating (p < 0.05) and flatulence (p = 0.06) decreased each week of the study. Fecal propionic acid was significantly increased over three weeks of DF supplementation. There was also an interaction (p=0.05) between time and age for butyric acid. Dietary fiber supplementation (10 g/day) over three weeks via a commercially available extruded cereal was well-tolerated by the participants, with no disturbances in bowel habit in children or adults. Alternatively, there were no improved bowel habit measures with increased DF consumption. This study provides evidence that this tolerable dose of DF supplementation over three weeks had similar impacts in free-living children and adults. However, the presence of increased butyric acid only in children may be reflective of different production or absorptive capacities between children and adults. Although not presented here, the bacterial ecological analysis may shed further insight into the interactions occurring in the large intestine. These are the first studies to my knowledge to have investigated these outcomes in young children. In addition to the gut health outcomes, this research provided a framework into the apparent feasibility of studying children in a gentle, non-invasive, and cost-effective manner.

The purpose of this study was to qualitatively explore the issues of race and mattering in relation to African American participation within historically White fraternities. Participant perspectives were obtained through six interviews with African American males at four collegial institutions within the Southeastern Region of the United States. Critical Race Theory was utilized to framed issues surrounding race in a homogenous Greek context. A second lens, Rosenberg and McCullough's (1981) concept of mattering, provided a comprehensive description of participants' feelings of significance within the inter-racial Greek experience. Thematic findings indicate that although African American members are recruited to be a part of a particular historically White fraternity's brotherhood, they initially experience marginality. Through continued interaction, the fraternal bonds become strengthened with participants rising to varying levels of leadership within the group, and, mattering to their White fraternal brothers. Other themes related to African American participation within historically White fraternities include: (a) One or no family member that attended college, (b) no immediate family members that are Greek, (c) significance of race is downplayed, (d) limited fraternal knowledge prior to entering college, (e) recruitment is driven by image, status, and counter assumption, (f) stereotypical organizations are racial holdouts; and, (g) discord exist with other African Americans that disapprove of the inter-racial experience.

The ad blocking hype has brought new challenges for fashion brands to be seen and heard. Therefore new marketing strategies have to be found. Since the usage of mobile devises increased and consumers spend more time on online social networks - influencer marketing had been found as a authentic marketing channel to reach the consumers. Therefore this thesis aims on providing fashion brands a guideline of the components and characteristics of influencer marketing. To accomplish this research objective the qualitative method approach of expert interviews had been chosen and four experts from the fashion influencer marketing were questioned about their daily work with influencers to elaborate their needs and the challenges they are facing. The interviews lead to four core components of influencer marketing: authenticity, long-term relations, co-creation and micro-influencers. Underneath these core components the following sub-components were found: brand fit, exclusivity, visual language, passion, trust, price, creative freedom, and frequent communication. The main conclusion of this study is that working with micro influencers is key a component of influencer marketing. These influencers tend to have high authenticity, are experts in a certain niche and are not motivated by monetary reasons.