Ultra High Molecular Weight Polyethylene (UHMw-PE) is an engineering polymer that is widely used in demanding applications because of its un-paralleled properties such as high abrasion resistance, high-modulus and high-strength tapes and fibres, biaxial films etc. In common practice, to achieve the uniaxial and the biaxial products, the solution processing route is adopted to reduce the number of entanglements per chain, such as found in Dyneema(R) from DSM(R). Another elegant route to reduce the number of entanglements to ease solid-state processing is through controlled polymerisation using a single-site catalytic system. In this theses, how different polymerisation condition, such as temperature and time control molecular weight and the resultant entangled state in synthesised disentangled UHMw-PE is addressed. Linear dynamic melt rheology is used to follow entanglement formation in an initially disentangled melt. With the help of rheological studies, heterogeneity in the distribution of entanglements along the chain length and the crystal morphology produced during polymerisation is considered. For the understanding of influence of large shear flow on melt dynamics large amplitude oscillatory shear (LAOS) is used and the non-linear viscoelastic regime is explored. A remarkable feature of overshoot in loss (viscous) modulus with increasing deformation (strain) in UHMw-PE melt in the LAOS is observed. This observation is characteristic of colloidal systems. The role of entanglement density in the amorphous region of the synthesised disentangled UHMw-PE (semi-crystalline polymers) on the melting and crystallisation is presented. To understand the effect of topological differences on melting behaviour, nascent entangled, nascent disentangled and melt-crystallised samples have been used. The role of superheating on the melting process is also addressed. Preliminary results on characteristic melting time of a crystal using TM-DSC are also presented.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

After the year of 1968, which was crucial in the history of the war in Indochina , a new phase of a conflict started to evolve. The United States, under President Lyndon B. Johnson, after the Tet offensive and massive domestic protests, finally retreated from the goal of military victory and changed its strategy to get out of the conflict as quickly as possible. Johnson had established negotiations with the Democratic Republic of Vietnam in Paris, which the South Vietnamese President Nguyen Van Thieu systematically negated. As it was later revealed, this was done in cooperation with the Republican candidate for President Richard M. Nixon, who wanted to do this in order to compromise policy of a Democratic president and take his place himself. Nixon, after his appointment to the presidency, assumed that renewed negotiations in Paris would be simple and would lead to the rapid end of the war. Soon it became clear that it was a mistake. North Vietnamese and communist insurgents in South Vietnam managed, due to conflicts caused by Thieu and by the delay between flares, to restore their strength and they were no longer willing to retreat. Negotiations bogged down in fruitless debates and disputes. Nixon and his closest collaborator Henry Kissinger were forced to seek other solutions. On the...

Contexte : Environ 257 millions de personnes dans le monde sont infectées de manière chronique par le virus de l'hépatite B (VHB). La transmission mère-enfant représente la majorité des nouveaux porteurs chroniques du VHB, en particulier en Asie. Le VHB peut être transmis in utero, lors de l'accouchement ou pendant la petite enfance voire plus tard. Environ 80 à 90% des nourrissons infectés à la naissance développent une infection chronique par le VHB avec le risque élevé de développer de graves complications, notamment une fibrose du foie, une cirrhose, un carcinome hépatocellulaire jusqu’à un décès lié au foie à l’âge adulte. Nous avons évalué la proportion des enfants immunisés avec succès dans deux grands hôpitaux de Vientiane, en République démocratique populaire lao, où l’immunoglobuline HB (HBIg) n’est pas disponible. Méthodes : Nous avons étudié une cohorte prospective de femmes enceintes infectées par le VHB et de leurs enfants jusqu'à six mois après la naissance de janvier 2015 à mars 2017. Tous les nourrissons ont reçu le vaccin anti-HB à la naissance et six, 10 et 14 semaines après la naissance. Le statut d’infection par le VHB chez l’enfant a été évalué à l’âge de 6 mois. Le séquençage du gène de surface du VHB a été effectué chez des couples mère-enfant infectés. Résultats : Sur 153 mères ayant été dépistées positives pour l'antigène de surface HB (AgHBs), 60 (39%) avaient l'antigène HBe (AgHBe) positif. Les femmes enceintes ayant AgHBe-positif étaient plus jeunes que les femmes ayant d’AgHBe négatif ((âge médian 26 versus 28 ans; p = 0,02). et avaient une charge virale du VHB significativement plus élevée à l'accouchement (médiane 8,0 versus 4,0 log10 UI / mL, p <0,001). Au total, 141 nouveau-nés, dont une paire de jumeaux, sont nés pendant l'étude. Parmi les 112 nouveau-nés pour lesquels l’information concernant le délai entre la naissance et l’heure d’administration du vaccin contre le VHB était disponible, 110 (98%) ont reçu le vaccin dans les 24 heures suivant la naissance. Le délai médian entre la naissance et l'administration du vaccin était de 6 heures (EI 3 à 13), avec 95 (72%) dans les 12 heures suivant la naissance. Un nouveau-né a reçu le vaccin 26 heures après la naissance car le vaccin n'était pas disponible dans la salle d'accouchement et un autre nouveau-né a reçu le vaccin 3 jours après la naissance car, en raison d'une détresse respiratoire sévère à la naissance, le vaccin a été considéré comme contre-indiqué. Parmi les 120 enfants évalués à l'âge de 6 mois, 5 (4%) étaient positifs pour AgHBs et présentaient une charge virale détectable pour le VHB par réaction en chaîne avec une polymérase. Tous sont nés de mères ayant l’AgHBe positif et une charge virale> 8,5 log10 UI / mL. Cependant, seulement quatre enfants (3,3%, IC à 95%, 0,5% à 7,0%) avaient une souche virale étroitement apparentée à celle de leur mère. Des mutations du gène de surface du VHB (G145G/R, G145G/A, M133T, M133I) ont été détectées chez 4 des 5 enfants infectés. Le taux d'anticorps anti-HBs était supérieur à 10 UI / L chez 105 nourrissons (88%) à l'âge de 6 mois. Conclusions : La transmission de la mère à l'enfant s'est produite moins souvent que ce que nous avions prévu en absence de l'utilisation de HBIg. L’ajout d’une prophylaxie par HBIg et / ou antivirale maternelle aurait pu prévenir certaines de ces infections. L'observation du taux d'anticorps anti-HBs non satisfait chez 9% des enfants non infectés à 6 mois souligne la nécessité d'améliorer les procédures d'immunisation universelles / Background: An estimated 257 million people are chronically infected with the hepatitis B virus (HBV) worldwide. Mother-to-child transmission accounts for the majority of new chronic HBV carriers, especially in Asia. HBV can be transmitted in utero, during delivery or during infancy and later. About 80–90% of infants infected at birth will develop a chronic HBV infection, and will have a high risk of developing serious complications including liver fibrosis, cirrhosis, hepatocellular carcinoma (HCC) and liver-related death during adult age. We aimed at assessing the percentage of infants successfully immunized in two major hospitals in Vientiane, Lao People's Democratic Republic (Lao PDR) where HB immune globulin (HBIg) is not available. Methods: We studied a prospective cohort of chronically HBV infected pregnant women and their infants until 6 months post-partum from January 2015 to March 2017. All infants received the HB vaccine at birth and 6, 10 and 14 weeks thereafter, and their HBV status was assessed at 6 months of age. HBV surface gene sequencing was performed in infected mother-infant pairs.Results: Of 153 mothers with HB surface antigen (HBsAg), 60 (39%) had detectable serum HBe antigen (HBeAg). HBeAg positive pregnant women were younger than those negative (median age 26 versus 28 years; p=0.02) and had a significantly higher HBV viral load at delivery (median 8.0 versus 4.0 log10 IU/mL, p <0.001). A total of 141 infants including a pair of twins were included in the study and information at the time of vaccine administration after birth was available for 112 newborns. Of these, 110 (98%) received the HepB-BD within 24 hours after birth. One newborn received the vaccine 26 hours after birth because the vaccine was not available at the delivery room, and another newborn 3 days after birth due to fetal distress, which was erroneously considered to be a vaccine contra-indication. Among the 120 infants assessed at 6 months of age, 5 (4%) were positive for HBsAg and had a detectable HBV viral load by polymerase chain reaction. All were born to mothers with HBeAg and a viral load >8.5 log10 IU/mL. However, only four (3.3%, 95% CI 0.5% to 7.0 %) had a virus strain closely related to their mother’s strain. HBV surface gene mutations were detected in 4 of the 5 infected infants (G145G/R, G145G/A, M133T, M133I). Anti-HBs antibody level was above 10 IU/L in 105 (88%) infants at 6 months of age. Conclusions: Mother-to-child transmission occurred less frequently than expected without the use of HBIg. Adding HBIg and/or maternal antiviral prophylaxis may have prevented some of these infections. The observation of unsatisfactory levels of anti-HBs antibodies in 9% of the uninfected infants at 6 months highlights the need for improvement of the universal immunization procedures

The thesis analyses the provision of "Aid for Trade" as a specific form of state building intervention (SBI) in Laos and Vietnam, two countries that have received trade-related assistance as part of their global economic integration. The thesis uncovers how global economic and institutional reform agendas related to trade integration are accepted or contested within both states, as part of a highly political process characterised by strategic agency and structural selectivities of various actors involved. The thesis employs a theoretical framework to help analyse how global trade governance programmes intervene within targeted states, and how local socio-political contestation shapes the outcomes of such programmes. Drawing on Marxist state theory, SBIs are understood as contested processes which open up strategic opportunities for social forces to shape the transformation process and thereby to stabilise or challenge existing power relations. Special attention is directed towards the state as an arena of conflict in order to understand the specific forms and varying results that these interventions take. This framework allows us to grasp how dominant social forces within the Laotian and Vietnamese forms of state are able to modify or circumvent external reform imperatives, resulting in highly selective changes in trade governance, which often departs from the intention of "Aid for Trade" project managers. The thesis thereby changes conventional technocratic assumptions that believe that aid interventions are a matter of best practice and contributes to a growing research agenda which analyses development interventions within the wider political economy of the targeted state.

Abstract not available

This thesis is about the heritage in Vientiane. In an attempt to go beyond a more traditional descriptive approach, the study aims at bringing forward a discussion about the definition, or rather the multiplicity of definitions, of the concept of heritage as such. The unavoidabe tension emanating from a modern western frame of thought being applied to the geographical and cultural setting of the study provides an opportunity to develop a criticism of some of the assumptions underlying our current definitions of heritage. For this particular study, heritage is defined as to include stories, places and things. It is a heritage that is complex and ambiguous, because the stories are parallel, the definitions and perceptions of place are manifold and contested, and the things and their meaning appear altered, depending on what approach to materiality is used. The objective is not to propose how to identify and manage such a complex heritage. Rather, it is about what causes this complexity and ambiguity and what is in between the stories, places and things. In addition, the study aims to critically deconstruct the contemporary heritage discourse, which privileges material authenticity, form and fabric and the idea that heritage values are universal and should be preserved for the future and preferably forever. In Laos, Buddhism dominates as religious practice. In this context, the notion of material impermanence also governs the perception of reality. Approaches to materiality in Buddhism are related to the general ideas that things are important from a contemporary perspective and primarily as containers for spiritual values, that the spiritual values carry the connection to the past, and that heritage is primarily spiritual in nature and has little to do with physical structure and form. By exploring the concepts of restoration, destruction and consumption in such a perspective, we understand that preservation and restoration are active processes of materialisation. We also understand that destruction and consumption are necessary for the appreciation of certain heritage expressions, and that heritage is being constantly created. With this understanding, this book is an argument for challenging contemporary western heritage discourse and question its fundamental ideology of preservationism.

This thesis is a study of three global issues – development cooperation, education and gender - and their transformation to local circumstances in Lao People’s Democratic Republic (PDR), a landlocked country in Southeast Asia. Combining post-colonial and post-structural perspectives, it sets out to understand how discourses of education and gender in Laos intersect with discourses of education and gender within development cooperation represented by organisations such as the World Bank and the Swedish International Development Cooperation Agency (Sida). Through field observations, analysis of national and donor policies on education and gender, and interviews with Lao educationalists, this thesis offers an analysis that shows the complexities arising at the intersection where the first-world-north meets the local in the context of development cooperation. Foucault’s notion of the production and reproduction of discourses through different power-knowledge relations is used to show that the meanings accorded to education and gender within development cooperation, indeed are historically, culturally and contextually constructed. Within development cooperation policy, first-world-north discourses appear to have a hegemonic status in defining education and gender. Thus ‘Education for All’ and ‘Gender Mainstreaming’ become privileged discourses that also take root in Lao national policy-making. Development cooperation further brings with it discourses defining the cooperation itself. Partnership is one such privileged donor discourse. These policy discourses are however interpreted by Lao educationalists that are not influenced by policy alone; rather, contextual discourses also affect how policies are understood and negotiated. It is when these discourses intersect that structures of power and preferential rights of interpretation become visible. The analysis points to how the perspectives of international development cooperation organisations representing the first-world-north are in positions to set the agenda for development cooperation within policy. This position of power can, from a post-colonial perspective, be traced back to how former colonial structures created a privileged position for first-world-north knowledge that still prevails. This is to some extent acknowledged by development cooperation organisations through the emphasis on partnership. However, in the local context, partnership is not experienced as a discourse which has the effects of redistributing power. Partnership is rather transformed into a discourse of superiority and subordination where development cooperation organisations monitor and evaluate and local actors adjust and implement. Lao education officials however express alternative interpretations of partnership that are based on face-to-face collaboration and collective effort. These strategies have closer links to local practices and also reflect contextual discourse-power-knowledge relations which the education officials are well aware of. These strategies of negotiation also extend to the issues of education and gender. Discourses of ‘Education for All’ and ‘Gender Mainstreaming’ are acknowledged among the education officials as policy goals which to some extent also extend into practice. These discourses are however renegotiated to accommodate local circumstances. ‘Education for All’ is thus replaced by the ‘5-pointed star’ which serves as an operationalisation of the concept of ‘learner-centred education’. ‘Gender Mainstreaming’ has to co-exist with local discourses that on the one hand build on patriarchal organisations of society and on the other hand build on local strategies for access which weaken patriarchal structures. The analysis ultimately stresses the importance of incorporating local, contextual knowledge in educational development cooperation processes, both among international and national stakeholders. This process can be supported by a willingness to deconstruct taken-for-granted understandings and value systems; and in doing so, recognising the normative aspects operating both in the areas of education and gender.

Cand. Polit thesis. / Format: PDF. Includes bibliographical references.