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Includes bibliographical references. / Science is unequivocal in its support for the importance of early childhood development. Calls for increased investment in young children cite neuroscience, developmental psychology and health. It is hazardous, however, to make a direct leap from neuroscience to policy recommendations. Simply because early childhood provides opportunities for more economically efficient interventions which have dramatic impact on inequality, this does not mean that the ECD policies actually implemented by communities, provinces, or national government are worthy investments. Firstly, it is difficult to design programmes that improve children's cognitive or behavioural development. Secondly, the costs of even effective programmes might outweigh the benefits they generate for children, their families, and taxpayers. And finally, programmes in early childhood require upfront and politically brave investments that may take decades to pay off.

Dans le présent travail, nous avons étendu aux solvants organiques notre méthodologie radiolytique de synthèse de polymères conducteurs (PCs), initialement développée en solutions aqueuses. Dans ce contexte, la polymérisation des PCs a été étudiée par radiolyse gamma dans différents solvants organiques et sous différentes conditions expérimentales. La synthèse radio-induite a, en particulier, été optimisée dans le dichlorométhane grâce à la variation et à l’ajustement de différents paramètres : atmosphère, dose, débit de dose, concentration des monomères, etc. Cette synthèse a ainsi pu mener à la préparation de différents types de polymères conducteurs : poly (3,4-éthylènedioxythiophène), poly (3-thiophène acétique acide) and Poly (3-hexylthiophène). Ces derniers ont été totalement caractérises en solutions ou après dépôt par des techniques analytiques, spectroscopiques et microscopiques complémentaires. Nous avons en particulier démontré la simplicité et la versatilité de la polymérisation radio-induite de TAA que ce soit dans le dichlorométhane ou dans l’eau, et avons mis en évidence quelques différentes notable entre ces deux voies de synthèse. Nous avons, par ailleurs, évalué l’influence de la nature des espèces radiolytiques oxydantes générées dans le dichlorométhane, via la variation de l’atmosphère de travail (N₂, air ou O₂), sur les propriétés des polymères conducteurs radio-synthétises, en particulier dans le cas de P3HT. Parmi les nombreuses propriétés physiques chimiques que nous avons sondées dans le cas de tous nos polymères conducteurs radio- synthétises les propriétés électroniques et électrochimiques ont fait l’objet d’une attention particulière. Nos matériaux ont alors été incorporés au sien de cellules solaires à pérovskite hybrides organiques-inorganique (PSCs) et y ont été utilisés comme matériaux de transport de trous (HTMs). Notre nouvelle stratégie radiolytique de synthèse décrite et étendu dans le présent manuscrit, ouvre sans aucun doute la voie à la préparation de nouveaux PCs nanostructurés, de morphologie contrôlée et aux propriétés augmentées : par exemple grâce à l’utilisation d’une polymérisation en microémulsions ou par le développement d’une copolymérisation raisonnée. / The extension of our original radiolytic methodology to the use of organic solvents was an important alternative approach to radiation-induced polymerization of conducting polymers (CPs) in aqueous solutions. The polymerization of CPs was studied by using gamma-radiolysis of several organic solvents under different environmental conditions. The optimization of the synthesis conditions of CPs was then conducted into dichloromethane solvent. After optimization of the synthesis conditions (atmosphere, dose, dose rate, concentration of organic monomers, etc.), the use of dichloromethane radiolysis was successfully employed to synthesize various types of conducting polymers: Poly (3,4-ethylenedioxythiophene) (PEDOT), Poly (3-thiophene acetic acid) (PTAA) and Poly (3-hexylthiophene) (P3HT). The radio-synthesized polymers were fully characterized in solution and after deposition by complementary analytical, spectroscopic and microscopic techniques. Also, the simplicity and versatility of radiation induced polymerization of 3-thiophene acetic acid in dichloromethane and in aqueous solutions was demonstrated. The differences between the two radiolysis routes were highlighted. Furthermore, the influence of generating different oxidizing species under different atmospheres (N₂, air or O₂) upon ɣ-irradiation of dichloromethane solutions containing organic monomers was also studied in particular in case of P3HT. The electronic and electrochemical properties were checked for all radio-synthesized CPs. Accordingly, these polymers were then incorporated in hybrid organic and inorganic perovskite solar cells (PSCs) and used as hole transport materials (HTMs). Our new radiolytic strategy described and extended in this manuscript opens the way for the preparation of new nanostructured CPs with controlled morphology and enhanced properties by using microemulsion polymerization and also for the preparation of processable conjugated materials through copolymerization.

This study evaluates the performance difference between hybrid and native mobile applica-tions when accessing the low level API. The purpose of this study is to find out the differ-ence in performance between the different methods for developing applications due to an increasing market for platform independent applications. Several benchmarks were created to measure the performance on the following criteria, execution time, memory allocation and storage space. The benchmarks were developed with a similar behaviour to match the functionality. The Titanium benchmarks were around 8.5 times larger in storage space and used 26-28% larger heap when it came to memory than the equivalent Android benchmarks. Android generally has a lower execution time than Titanium, however there are cases such as the math library where Titanium has a lower execution time.

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The thesis is concerned with describing new ways of using computers to create images of 3-dimensional designs. It also introduces novel methods for manufacturing some of these designs using numerically controlled machine tools. The work began as an extension of an existing surface design package called 'DUCT'. This was a program capable of holding descriptions of subtly curved surfaces, but which could only display them using line drawings. It was the first task of the author to examine different methods for depicting surfaces and then to decide which one was the most suitable for use in conjunction with industrial design work. Once done, this led on to ways in which the rendering methods could be improved. These improvements then enabled the package to be used in new application areas such as realistic image synthesis for advertising and animation. In tandem with this, new methods were developed for verifying the machining paths generated by DUCT for use on 3-axis milling machines. The methods developed for machining path verification were then extended to give improved techniques for the generation of such machining paths. The new approach allowed the manufacture of objects which were beyond the scope of previous surface design systems. The work on depicting objects manufactured using a 3-axis milling machine drew attention to the related problem of depicting realistic terrain. The author improved the existing methods for defining detailed surfaces such as mountains, and then went on to suggest new techniques for rendering such terrain in perspective. The new algorithms led naturally to the possibility of implementation on parallel computers and a paper study was made of the trade-offs involved in choosing different parallel computing architectures.