Submitted in fulfillment of the requirements for the degree of Doctor of Engineering: Mechanical Engineering, Durban University of Technology, Durban, South Africa, 2015. / Vacuum Infusion (VI) and Resin Transfer Moulding (RTM) are liquid composite moulding processes used in the manufacture of components from composite materials. The composite material in this case consists of a resin matrix combined with fibre reinforcement. In both moulding processes, a dry reinforcement preform is placed in the mould cavity and a liquid resin is introduced, driven by a pressure differential. Two rigid surfaces are used in RTM to create a fixed mould cavity. In contrast VI implements only one rigid surface and a flexible membrane or vacuum bag to form a non rigid cavity. The flexible cavity in VI influences and differentiates resin flow behaviour from that of RTM. Modelling resin flow enables the velocity, pressure and flow direction to be predicted. Resin flow in the RTM process is understood and modelled using Darcy’s law. However, flow in the VI process is not accurately modelled due to the added complexity introduced as a result of the flexible cavity. In the present work a novel approach was developed to investigate fluid flow in both processes. A unique experimental setup and testing procedure allowed for the direct comparison of fluid flow in RTM and VI. Identical flow parameters, conditions and preform construction were used in the assessment. The comparison isolated the effect of preform thickness variation as a differentiating factor influencing flow. From the experimentation, material behaviour was characterised and used to evaluate flow models for RTM and in particular VI. The model solutions were compared back to corresponding experiments. The pressure distribution behind the flow front, fill time and thickness behaviours were assessed. The pressure distribution / profiles behind the flow front of both VI and RTM were noted to be scalable with flow front progression. The profiles were curved in the VI experiments and linear in the RTM case. All VI models evaluated including the non accumulation based model accurately predicted the pressure distribution and consequently thickness variations in the VI tests. Fill times of the VI experiments were longer than that of the equivalent RTM tests. This behaviour is in contrast to previously interpreted fill time behaviour for the VI process based on VI models. It was also noted that the VI fill times were not only proportional to the square of the fill length, as in the RTM case, but also proportional to the square of the mass present. In addition, no significant accumulation was noted in the VI experiments. / D

Electroluminescence is a developing area of research in the fields of display technology and lighting. Solution based processing of organic materials offers the opportunity to manufacture large area, low cost illuminating surfaces but current processes are limited to two dimensions. The ability to apply electroluminescent materials onto three dimensional contoured surfaces would incorporate the illuminating function into objects, enhancing usability and removing the need for an additional light source. Furthermore, the integration directly into the manufacturing process, such as injection moulding, would have the added benefits of reducing manufacturing time, handling and have environmental and economic savings. Incorporating electronics manufacturing in-mould offers considerable potential for novel research and commercial applications. Electroluminescent multi-layer structures were constructed on 3D surfaces, applying materials using an airbrush. Novel injection moulded electroluminescent devices were successfully made using insert moulding and in-mould layer application techniques, then characterised and compared to a bought device. Electroluminescent layers were also applied to injection moulded plastic parts as a post mould treatment for further comparison. In the current state of development, insert moulding using a PTFE carrier film is the most successful method of injection moulding EL parts, producing devices that light up with an average illuminance of 210.2  39.2 lx when operated at 300 V and 400 Hz. A multi-layer thermal model developed in this project confirms that the injected plastic does not transfer enough heat energy to cure materials that are applied directly in-mould. It was also found that, after 10 weeks, the airbrush made devices maintained 27.3 % points more relative illuminance compared to devices made using a conventional method. Problems associated with all of the new processes have been identified and solutions suggested, but with further research these methods could be used to routinely mould plastic parts with the ability to illuminate.

The hydrogenation of nitrobenzene to form aniline is a large-scale industrial process performed using a variety of heterogeneous catalysts. One variant of the process involves the application of alumina-supported Pd catalysts. Although several 0.3 wt% Pd/alumina formulations exhibit high aniline selectivity (ca. 98%), different grades of these catalysts favour different impurities. It is observed that the impurities arise from different reaction pathways depending on the provenance of the catalyst. In order to investigate whether the origins of impurity formation are connected to catalyst structure, a series of Pd catalysts active for this reaction have been characterised by a variety of techniques: chemisorption measurements, X-Ray Diffraction, Transmission Electron Microscopy, Temperature-Programmed Desorption and Infrared spectroscopy. The low metal loading industrial grade catalysts are challenging to characterise and required a degree of analytical refinement. Temperature-programmed infrared measurements of the probe molecule carbon monoxide revealed morphological and energetic information that could be correlated with catalytic performance. This information constitutes part of a valuable feedback loop that enables specifications for the next generation of ultra-selective nitrobenzene hydrogenation catalysts to be determined.

The aim of this project is to explore the social and ethical dimensions of the agricultural production of perennial energy crop and crop residues for energy. Biomass – any living or recently living matter – is being promoted in industrialised countries as part of the transition from fossil fuels to an economy based on renewable energy. Various challenges face the use of bioenergy however. One particularly controversial and high profile example has been the use of food crop biofuels in transport which are seen to conflict with food production and to cause significant environmental damage. Suggested ways around these controversies is the production of perennial energy crops such as grasses and trees and crop residues such as straw, which are seen to require fewer inputs and less prime land. Some have analysed the controversies raised by biofuels in terms of controversies around industrial agriculture more broadly: biofuels are perceived to be large scale, monocultural, environmentally damaging and pushed by agri-business and energy interests. This project asks what type of agriculture system perennial energy crops and crop residues are seen as developing within, if at all. This was considered worth exploring because the type of system will have a large bearing on how they are received in future. To this end a theoretical framework of different paradigms of agriculture ranging from industrial agriculture at one end to alternative agriculture at the other was developed and applied to the data. Interviews with key stakeholders and analysis of key documents in the UK and Denmark were carried out to address the question of how perennial energy crops and crop residues are seen as overcoming previous controversies raised by food crop biofuels, in terms of their place in agricultural systems. The thesis argues that stakeholder’s visions of perennial energy crops and crop residues can be understood in terms of four models of agriculture: two industrial and two alternative. These are called “industrialism lite” that involves producing perennial energy crops on marginal land; life sciences integrated agriculture including the biorefinery strategy; multifunctional perennial energy crop production on environmentally marginal land; and ecologically integrated multipurpose biomass production through agroforestry production. There is also an argument which cuts across the paradigms and maintains that regardless of the type of agricultural system used very little or no biomass should be produced for the energy sector because of the scale of resources it requires and the scale of society’s energy use. These positions can be summarised as three different ways to overcome challenges raised by food crop biofuels: further industrialise agriculture; de-industrialise agriculture; and de-industrialise agriculture and reduce society’s energy use, though biomass could still only be used to a very limited extent, if at all, in energy production.

Microporous materials play an important role in a variety of industrial and domestic applications. While a diverse range of microporous materials have been identified, this thesis focuses on porous organic cages (POCs) because they have received much attention as synthetically tunable, solution processable, microporous materials. After introducing the latest developments in POC synthesis and the general application of microporous materials as selective sorbents, this thesis presents three developments in organic cage chemistry: a high-throughput workflow for the discovery of POCs, which yielded a novel organic cage compound; the measurement of selective adsorption by POCs, wherein the first instance of chiral selectivity by a POC was recorded; and the first instance of applying POCs as stationary phases for gas chromatography, which produced columns that separate racemic mixtures, alkylaromatic isomers, and alkane isomers. Chapter 2, discovering novel organic cages, presents attempts to use high-throughput and in-silico techniques to accelerate the discovery of novel organic cages. These methods were utilised to isolate a novel organic cage, CCX-S, which is characterised and discussed. Chapter 3, organic cages as selective sorbents, presents the development of approaches for measuring selective adsorption. These methods were used to identify the first reported instance of enantioselective adsorption by an organic cage. Further measurements to explain this separation behavior are also presented. Chapter 4, chromatographic separations with organic cages, presents one method of practically leveraging the presented separation behavior. In Chapter 4, the coating of capillary columns with CC3 is presented. These columns were used to successfully perform gas chromatographic separations, the first recorded instance of using a POC to do so. The columns were further improved by modifying the coating method and using prefabricated CC3 nanoparticles. This modification enabled difficult separations to be performed using the column; for example, the separation of hexane’s five isomers.

On-site chemical detection and monitoring of compounds related to homeland security applications, civil defence and forensics is difficult using conventional instrumentation. Target analytes include human chemical signatures (for detection of illegal immigration), drugs of abuse, explosives and chemical warfare agents (CWAs). A convenient solution is to complement existing techniques using portable membrane inlet mass spectrometry (MIMS). This thesis deals with the mass spectrometric investigation of characteristic chemical odour signatures emitted by human exhaled breath and skin as chemical signs of human presence in a confined space. It also presents detection results of threat and threat related chemical compounds. Numerical modelling of ion injection and confinement in a non-scanning linear ion trap (LIT) mass analyser for achieving sensitivity enhancement was carried out. A novel portable artificial sniffer based on linear ion trap (LIT) technology has been designed and developed. Initial performance results are described. Preliminary field trials have led to positive outcomes which are currently being commercially exploited.

Orientador: Leinig Antonio Perazolli / Banca: Marcos Augusto de Lima Nobre / Banca: Rossano Gimenes / Resumo: Neste projeto foram obtidos pós fotocatalíticos de TiO2/SnO2 modificados com Ag2O, utilizando o método dos precursores poliméricos (Pechini). A composição dos óxidos foi TiO2(75%)/SnO2(25%) e o agente modificador Ag2O nas concentrações: 0,01, 0,05, 0,10, 0,50 e 1,00 mol%. Estes óxidos foram analisados utilizando difratometria de Raios X (análise da cristalinidade), área superficial (SBET - análise de area superficial), FEG/MEV (análise da morfologia das partículas), XPS (análise das interações atômicas na superfície) e espectroscopia de refletância difusa (no ultravioleta-visível - UV-Vis - análise do "band-gap" dos óxidos). As atividades fotocatalíticas foram medidas, utilizando um reator montado em nossos laboratórios, realizando a fotodecomposição de soluções de Rodamina B, catalisada pelos óxidos em estudo, em um estudo da descoloração proporcional que foi medida em um espectrofotômetro no comprimento de onda de 300 a 700nm. Os estudos de atividade fotocatalítica foram realizados tanto em lâmpada UV como na luz solar e os resultados foram semelhantes, ou seja, obteve-se um óxido com o mesmo comportamento na luz solar. Estes estudos foram realizados para comparar a mudança na atividade fotocatalítica ao variar a concentração do agente modificador (Ag). Verificou-se que durante o processo de calcinação surgem aglomerados nos óxidos fotocatalisadores, que podem degenerar o efeito da fotoatividade. Obteve-se pós com fotoatividade catalítica, que apresentaram degradação da Rodamina B em 11 minutos, valor próximo aos 9 minutos obtidos para a degradação utilizando P25 (DEGUSSA), que é um óxido comercial amplamente utilizado e estudado / Abstract: In this project, photocatalytical TiO2/SnO2 powders modified with Ag2O were obtained by the polymeric precursor method (Pechini). It were obtained to result in a final oxide composition of: TiO2(75%)/SnO2(25%) and the modifying agent (Ag2O) concentration: 0.01, 0.05, 0.10, 0.50 and 1.00 mol%. This powders were analyzed using X-Ray diffractometry (to analyze the phases formed), superficial area (SBET), by FEG/SEM (to analyze the superficial characteristics), XPS (to analyze the superficial atomic interaction) and diffuse reflectance spectroscopy (on ultraviolet visible - UV-Vis - to analyze the powders band-gap). The photocatalytic activities were measured, using a homemade reactor, during the decomposition of Rodhamine B (RB) solutions, in a study of the proportional discoloration measured in a scanning spectrophotometer in the wave length 300 to 700nm. The RB decomposition studies were carried on both UV-lamp and sun-light and the results were similar, this means that were obtained an oxide with the same behavior on sun-light. This was made to compare the photocatalytic activity when varying the modifier agent concentration (Ag). It were also verified that during the calcination process that some agglomerates evolves and that can degenerate the photocatalytical effect. It were obtained photocatalytical powders, that degenerate RB in 11 minutes, close to the 9 minutes obtained by degradation using P25 (DEGUSSA) that is a commercial oxide widely used and studied / Mestre

As rotas sintéticas para obtenção de cloridrato de petidina foram avaliadas sob o ponto de vista tecnológico, material e de segurança com o objetivo de adaptar a produção a reatores multipropósito. O aperfeiçoamento de técnicas antigas e introdução de técnicas recentes como a catálise de transferência de fase viabilizaram o projeto. / The synthetic routes for obtention of pethidine hydrochloride were evaluated under technologycal, material and safety aproach, in order to be able to manufacturing in multipurpose reactors. The improvment of old techniques and introduction of recents advances like phase transfer catalysis \"P.T.C.\" making it a available presentation.

As rotas sintéticas para obtenção de cloridrato de petidina foram avaliadas sob o ponto de vista tecnológico, material e de segurança com o objetivo de adaptar a produção a reatores multipropósito. O aperfeiçoamento de técnicas antigas e introdução de técnicas recentes como a catálise de transferência de fase viabilizaram o projeto. / The synthetic routes for obtention of pethidine hydrochloride were evaluated under technologycal, material and safety aproach, in order to be able to manufacturing in multipurpose reactors. The improvment of old techniques and introduction of recents advances like phase transfer catalysis \"P.T.C.\" making it a available presentation.

The objective of this thesis is to advance the current understanding of some pertinent formulation and processing interactions informing final cake microstructures. A primary concern is to understand how certain ingredients, fundamental to cake batter formation interact, to develop new methods and models for optimising and characterising these microstructures. The motivation of this work stems from the empirical methods still prevalent within cake research. However, an approach based on fundamental understanding of formulation and processing functions is necessary for both future innovation and eradication of some current challenges facing the cake baking industry. A bottom-up approach begins by exploring the interactions of key structural components; starch and protein within wet-foam systems with an objective of maximising foaming capacity and stability through focus on formulation design. Consequently, the structure of the model system is further developed to resemble a foam based cake in which the influence of formulation is evaluated through novel characterisation methods novel to this field of research. The work ultimately combines microstructure design, development and characterisation to maximise air retention within model cake systems.