Recent literature in the social sciences has emphasized the socially constructed nature of knowledge. Consequently, this has had a bearing upon the understanding of science; interpretations of the natural world; and issues associated with understanding 'the Other'. The relevance of these wider social debates can be extended into a consideration of 'natural' hazards in different cultural contexts. This thesis attempts to develop a 'middle ground', drawing on theories of critical realism, that appreciates the socially constructed nature of scientific practice, but that retains the empancipatory, positive potential of science and that allows intervention in other cultural contexts. The remainder of the thesis attempts to put some of these ideas into practice and to develop the implications of these arguments for those interested in understanding and mitigating 'natural' hazards in other cultures. Two case studies are used, relating to Egypt and the U.K., which explore the scientific understandings of 'natural' hazard events in two different cultural contexts. Fundamental to the approach adopted is the need to acknowledge science as a social practice and how it functions within different societies. Examples are given, pertaining to both Egypt and the U.K., of what this might mean in 'practice'. In summary, therefore, there is an appreciation of the implications of recent social science literature for hazards research and the development of a practical approach to hazards with a social and philosophical justification

This thesis analyzes the experiences of participants of the Canadian Labour Congress and Saskatchewan Federation of Labour radical labour youth activist training program “Solidarity Works.” The theoretical work of Antonio Gramsci and Paulo Freire is used to analyze why radical labour education is important. The theoretical work of Michel Foucault is used, in addition to the work of Gramsci and Freire, to examine the complications of radical labour education. The essential argument of this thesis is that radical labour education programs like Solidarity Works produce an activist subjectivity that ultimately comes into conflict with the institutionalized politics of the labour movement. Solidarity Works is a model radical labour education project, its challenges and successes warrant analysis so those lessons can be used for future radical labour education projects.

Free radical polymerization is the most common polymerization technique that is used for the manufacturing of polymers, due to the ease of the polymerization initiation, wide latitude of the material design for a large variety of monomers, and the excellent process robustness for commercial production. In the 1990’s, research activities for the precise control of radical polymerization process resulted in the discovery of ‘Living Radical Polymerization’. The discoveries opened the door for the next generation of radical polymerizations. Extensive research has been conducted to understand the mechanisms and kinetics for numerous practical applications, particularly for polymerization in bulk and solution systems. However, despite the interest of industry, the mechanistic understanding in aqueous dispersed systems such as emulsion and miniemulsion polymerization is far behind the aforementioned two systems. There are still major challenges from the production viewpoint. One reason for the poor understanding is the complexity of the heterogeneous system, which includes multiple　reaction phases that are accompanied by the segregation and transfer of the reaction species among different phases. The purpose of this research was to investigate living radical polymerization or “Stable Free Radical Polymerization” (SFRP) in aqueous dispersed systems to obtain better mechanistic understanding of how the heterogeneous nature of the system interacts with the novel living radical chemistry. The theoretical and experimental feasibility of the SFRP emulsion process were studied in this research, in particular, focusing on the compartmentalization effect. Particle size influence on the polymerization kinetics and the polymer livingness was experimentally confirmed, and compared to bulk polymerization. In addition, a comprehensive mathematical model including all major chemical and physical events was developed to further our mechanistic understanding. Based on the results from the experimental and modeling studies, it was shown that rate reduction in the smaller particles is the primary cause of difficulty in implementing a conventional emulsion process (i.e. ab initio emulsion polymerization). Finally, for overcoming this difficulty, a new approach using a combination of TEMPO with highly hydrophobic 4-stearoyl TEMPO was proposed for a coagulum free ab initio emulsion process. / Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2010-02-18 09:49:52.336

Controlled radical polymerization (CRP) has emerged as a powerful method of creating polymers with tailored molecular architectures under mild reaction conditions. However, production of these polymers efficiently at an industrial scale will likely require them to be synthesized in the dispersed phase. Three types of CRP are explored, Atom Transfer Radical Polymerization (ATRP), Nitroxide Mediated Polymerization (NMP) and Catalytic Chain Transfer (CCT) to elucidate the intricacies of creating these novel polymer colloids. Compartmentalization in an ATRP dispersed phase system is explored theoretically to understand the effects of particle size and catalyst concentration on the polymerization. The results suggest that there is an optimal range of particle sizes where the rate of polymerization is greater than that in an equivalent bulk system while maintaining both a lower PDI (polydispersity index) and higher livingness. All three factors are desirable in ATRP but generally cannot be achieved simultaneously in bulk. Compartmentalization manifests itself differently in CCT dispersed phase systems, where the segregation of the CCT agents into different polymer particles leads to multimodal molecular weight distributions. Control over the particle size is notoriously difficult for nitroxide mediated polymerization, as it is challenging to decouple an increase in the particle size with an increase in target molecular weight using a two stage emulsion polymerization approach. This often leads to colloidally unstable latexes for low molecular weight, high solids conditions which are the result of superswelling. We offer several strategies to minimize this problem and create colloidally stable, high solids, n-butyl acrylate latexes by NMP with moderate to high molecular weight targets (>70 kg/mol). Using this synergy between target molecular weight and particle size, high solids (>40 wt.%), high molecular weight (<200 kg/mol) microemulsions (~20 nm) of methyl methacrylate-co-styrene were prepared. Finally, the monomer type and nucleation mechanisms also play a role in determining the particle size distribution in NMP emulsion systems. Using n-butyl methacrylate in emulsion with surfactant concentrations above the critical micelle concentration yields latexes with bimodal particle size distributions. However a surfactant-free approach allows monomodal latexes to be created. / Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2010-12-03 13:30:15.346

No description available.

<p>&nbsp / </p> <p align="left">The main aim of this study was to design new polyfunctional ligands based on the polypropyleneimine dendrimer&nbsp / <font face="Arial">DAB-(NH</font><font face="Arial" size="1"><font face="Arial" size="1">2</font></font><font face="Arial">)</font><font face="Arial" size="1"><font face="Arial" size="1">4 <font face="Arial">referred to as </font><b><font face="Arial,Bold">L1 </font><font face="Arial">in this work, to be used in </font></b></font></font><font face="Arial">copper mediated atom transfer radical polymerization (ATRP) of vinyl monomers. These ligands were synthesized by modifying DAB-(NH</font><font face="Arial" size="1"><font face="Arial" size="1">2</font></font><font face="Arial">)</font><font face="Arial" size="1"><font face="Arial" size="1">4 </font></font><font face="Arial">with aromatic and aliphatic substituents on the nitrogen atoms at the periphery of </font><b><font face="Arial,Bold">L1</font><font face="Arial">.</font></b></p>

This thesis analyzes the experiences of participants of the Canadian Labour Congress and Saskatchewan Federation of Labour radical labour youth activist training program “Solidarity Works.” The theoretical work of Antonio Gramsci and Paulo Freire is used to analyze why radical labour education is important. The theoretical work of Michel Foucault is used, in addition to the work of Gramsci and Freire, to examine the complications of radical labour education. The essential argument of this thesis is that radical labour education programs like Solidarity Works produce an activist subjectivity that ultimately comes into conflict with the institutionalized politics of the labour movement. Solidarity Works is a model radical labour education project, its challenges and successes warrant analysis so those lessons can be used for future radical labour education projects.

The object of study of this thesis lies on the optimisation of the oxidative radical cyclisation methodology for the preferential formation of gamma-lactones from unsaturated alkyl malonate derivatives. <strong>Chapter 1</strong> introduces the concept of free-radical cyclisation; more extensive explanations are given for the intramolecular oxidative radical cyclisation using manganese(III) and copper(II) salts as oxidants. An overview of the contribution of the Burton group in the field is given, in which both the applicability and the limitations of the transformation are showcased. <strong>Chapter 2</strong> is concerned with the synthesis of the ethisolide family of natural products and one non-natural analogue, in which the oxidative radical cyclisation is key for the construction of the bis-gamme-lactone moiety present in such natural products. The initial limitations of the methodology allowed for the discovery of new conditions for the formation of chloro monocyclic systems and for the development of copper-free oxidative cyclisation conditions for gamma-lactone formation. <strong>Chapter 3</strong> reports the developments on the metal-free oxidative radical cyclisation. Bicyclic gamma-lactones were synthesised from all-carbon alkyl malonate derivatives through anodic oxidation via constant current electrolysis. The development of a novel ionic oxidative cyclisation is also discussed. <strong>Chapter 4</strong> describes our efforts towards the formation of both fused and spiro gamma-lactam-beta-lactone molecules, as potential analogues to proteasome inhibitors, from either gamma-lactam-gamma-lactones or exo-gamma-lactams precursors, previously synthesised through oxidative radical cyclisation. Full experimental details, NMR spectra for the natural products and for the non-natural analogue, and a comparison between the obtained and the previously reported NMR data are also provided.

No description available.

This thesis is concerned with the development of cyclisation strategies that allow entry to polycyclic heterocycles and medium sized ring systems. Radical additions to pyridines are developed and methodologies explore the differences between the homolysis of C-Br and C-I bonds. Mechanisms are described for the unexpected ipso additions to the pyridines. Work towards the synthesis of the stegnans and dimethylgomisin illustrates the attempts to utilise the ipso addition to form medium sized ring systems. A new method of synthesising these medium sized ring systems is discussed. Progress towards a general methodology is described and shows the opportunities for which it could be utilised. A literature review of the synthesis of heterocycles via radical cyclisations is presented.