Les travaux effectués durant cette thèse ont eu pour objectif le développement de chromophores fonctionnels à base de sels de styrylpyrylium et styrylpyridinium. Les divers composés synthétisés ont montré une très grande flexibilité concernant leurs propriétés optiques, avec notamment des longueurs d’onde d’absorption et d’émission couvrant la quasi-totalité du spectre visible. Associée à la variabilité structurelle inhérente à ce type de chromophore, il est possible d’obtenir des composés aux propriétés modulables, et intégrables dans une large gamme d’applications.Ce manuscrit est constitué de trois parties principales. La première décrit la synthèse et les propriétés photophysiques de divers chromophores obtenus durant cette thèse. La seconde décrit l’approche théorique, utilisée pour faciliter la conception et l’analyse des composés étudiés. Finalement, la troisième partie décrit les applications pour lesquelles certaines variations de sels de styrylpyrylium et styrylpyridinium ont étés spécialement développés. / The work done during this thesis aimed to develop functional chromophores based on styrylpyrylium and styrylpyrylium salts. The compounds synthesized have shown a great flexibility regarding their optical properties, including maximum wavelength of absorption and emission covering almost the entire visible spectrum. Combined to their structural adaptability, it was possible to design various compounds compatible with a wide range of applications.This manuscript is composed of three main parts. The first part describes the synthesis and the photophysical properties of some chromophores obtained during this thesis. The second describes the theoretical approach, used to assist the design and the analysis of the studied compounds. Finally, the third part describes various applications for which some styrylpyrylium and styrylpyridinium salts have been specially designed.

O câncer de pele se apresenta como um sério problema de saúde pública mundial, sendo incidente nos cinco continentes. As ações relacionadas à prevenção dessa doença envolvem, entre outras coisas, a utilização de protetores solares e a educação em saúde. Em virtude do aumento do número de indivíduos com câncer de pele a cada ano, é de grande valor estudos de entendimento e desenvolvimento de filtros solares melhores e mais seguros. Os produtos utilizados com a finalidade de proteger a pele dos raios solares ultravioletas (UV) possuem em sua composição filtros solares, que podem ter ação física, refletindo e dissipando a radiação UV; ou ação química, absorvendo a radiação UV. Os filtros químicos podem apresentar absorção em UVB (290-320 nm), UVA (320-400 nm) ou em ambas as faixas, sendo considerados de amplo espectro. . Dentre as várias classes de compostos com perfil de filtro solar UVB, os cinamatos destacam-se por apresentarem boa eficácia e excelente custo-benefício. A aplicação de cálculos teóricos tornou-se indispensável no planejamento de fármacos e nos estudos de mecanismo de ação de moléculas bioativas, visto a diminuição de tempo e custos em pesquisa e desenvolvimento. O desenvolvimento de métodos quânticos robustos, como o TD-DFT, permitiu a simulação de propriedades experimentais in silico, tais como espectros de RMN e UV. Diante deste panorama, aplicamos tal método na simulação de espectros UV para os cinamatos com perfil de filtros solares. Realizou-se uma busca do melhor funcional para simulação dos espectros, na qual se determinou que os funcionais B3LYP e B3P86 apresentaram melhores resultados quando comparados ao espectro experimental do composto p-metoxicinamato de etilexila determinado em metanol. Foram simulados os espectros de UV para sete compostos derivados do ácido cinâmico, os quais apresentaram λ máximo próximo a 310 nm, como descrito na literatura. Observou-se que a energia média para que ocorra a principal transição eletrônica, de HOMO para LUMO, é de 3,95 eV. O método mostrou-se adequado para a determinação de espectros UV para a classe dos cinamatos e pode ser utilizado na busca de novos compostos dessa classe a serem empregados como filtros solares. / Skin cancer presents itself as a very serious world public health problem, being incident all over the five continents. Using sunscreen and receiving health education, among other factors, are related to prevent the disease. The number of people with skin cancer increases every year, therefore, studies for better knowledge and development for better and safer sunscreens are crucial. Products used with the intention to protect the skin from ultraviolet sunrays (UV) are partially composed by sunscreen, which may lead to two different reactions, a physical reaction, that reflects and ceases the UV radiation; or a chemical reaction, that absorbs the UV radiation. Chemical filters may present absorption in UVB (290-320 nm), UVA (320 400 nm) or in both, which is considered as broad spectrum. Among the various types of compound forms with sunscreen UVB profile, cinnamates stand out for presenting good efficiency and excellent cost-benefit. The application of theoretical calculations became essential for drug design and bioactive molecules action mechanism studies, considering time saving and costs in research and development. The development of robust quantum method, such as TD-DFT allowed the simulation of experimental properties in silico, like RMN and UV spectra. Given this overview, this method was applied to simulate UV spectra of cinnamates with sunscreen profile. A search was done to define the best functional to simulate all spectrum, where the functionals B3LYP and B3P86 showed the best results when compared to experimental spectra of the compound ethylhexyl methoxycinnamate determined in methanol. An UV spectrum simulation for seven compounds derived from cinnamic acid showed maximum wavelength around to 310 nm, as described in the literature. It was observed that the average energy for the main electronic transition, HOMO to LUMO, is 3,95 eV. The method proved to be adequate for the determination of UV spectra for cinnamate class and it can be used as a tool on the search for new compounds from this class to be used as sunscreen.

The changes that are occurring in the corporate world since the Industrial Revolution greatly changed this environment, particularly with regard to the role played by workers in the productive scenario. This came to be seen as a condition for business success, as long as their skills are developed through qualification actions, which while maintaining the employability of the workers, develop skills required by the world of work. The objective that directed the efforts on this research was to investigate the social representations concerning the techniques of group dynamics in work organizations. This is a search with exploratory approach and that was made using fifteen workers from four companies of different branches of business. All participants were subjected to these techniques in a training context, development and education between the years 2008 and 2009. To generate the data, the interview technique was used and for it‟s analysis, it was chosen the technique of content analysis. This theme was analyzed from the theoretical perspective of social psychology, considering three conceptual pillars: Group Dynamics‟ theory, reflections about the world of work and the theory of Social Representation. Among the key findings is the reified representation of the respondents on the group dynamic as a learning tool, capable of causing change in behavior through the application of systematic activities that provoke self-analysis and transferability of knowledge to real work situation, since conducted by a professional with expertise and targeted to a specific audience. In the thematic group on 'concepts of DG' is important to highlight the fact that representations suggest a direct relationship with the practice, ie, the anchors of the individuals are guided by the social practices. The theme group 'context of application' stated that DG can create a context for development of behavioral skills and techniques through the proposition of corporate experiences in similar situations. In the categories of the thematic group 'utility and effect' was possible to verify how the representations of DG are associated with their functionality, purpose and usefulness. Finally, the thematic group 'representations of inefficiency' results show the understanding that the DG is far from being understood as a tool uncommitted to the social reality. This study sought to articulate reflection on the social representation of group dynamics within the world of work, which enables the analysis of the impacts that such techniques have in organizational processes, in addition to providing problematizations on theoretical and practical issues pertinent to the field of organizations. / As mudanças quem vêm ocorrendo no universo corporativo desde a Revolução Industrial mudaram sobremaneira esse ambiente, especialmente no que diz respeito ao papel ocupado pelo trabalhador no cenário produtivo. Este passou a ser visto como condição de sucesso do negócio, desde que suas capacidades sejam desenvolvidas através das ações de qualificação, as quais ao mesmo tempo em que mantêm a empregabilidade do trabalhador, desenvolve habilidade exigidas pelo mundo do trabalho. O objetivo que direcionou os esforços desta pesquisa foi o de investigar as representações sociais acerca das técnicas de dinâmica de grupo em organizações de trabalho. Trata-se de uma pesquisa de caráter exploratório e que teve como participantes quinze trabalhadores de quatro empresas de ramos distintos de negócio. Todos os participantes da pesquisa foram submetidos a estas técnicas em contexto de treinamento, desenvolvimento e educação (TD&E) entre os anos de 2008 e 2009. Para a geração dos dados foi utilizada a técnica de entrevista e para sua análise fez-se opção pela técnica de análise de conteúdo. A temática foi analisada a partir da perspectiva teórica da Psicologia Social, considerando três pilares conceituais: a teoria da Dinâmica de Grupo, reflexões acerca do mundo do trabalho e a teoria da Representação Social. Entre os principais resultados está a representação reificada dos entrevistados sobre a dinâmica de grupo como ferramenta de aprendizagem, capaz de provocar mudança de comportamento através da aplicação de atividades sistemáticas que provocam auto-análise e a transferibilidade do conhecimento para a situação real de trabalho, desde que conduzidas por um profissional com expertise e direcionadas a um público específico. No grupo temático sobre os conceitos da DG‟ é importante destacar o fato de que as representações sugerem uma relação direta com a prática, ou seja, as ancoragens dos sujeitos estão pautadas nas práticas sociais. O grupo temático contexto de aplicação‟ indicou que a DG permite criar um contexto para desenvolvimento de habilidades comportamentais e técnicas através da proposição de situações idênticas a vivências corporativas. Nas categorias do grupo temático utilidade e efeito‟ foi possível verificar o quanto as representações sobre a DG estão associadas a sua funcionalidade, finalidade e utilidade. Por fim, no grupo temático representações de ineficácia‟ os resultados revelam o entendimento de que a DG está longe de ser entendida como ferramenta descomprometida com a realidade social. Este trabalho pretendeu articular a reflexão sobre a representação social da dinâmica de grupo no contexto do mundo do trabalho, o que possibilita a análise dos impactos que tais técnicas têm nos processos organizacionais, além de propiciar problematizações sobre questões teóricas e práticas pertinentes ao campo das organizações.

Neste trabalho estudamos o espectro de absorção da clorofila d, incluindo os efeitos do solvente metanol, utilizando a Teoria do Funcional da Densidade Dependente do Tempo em combinação com o método s-QM/MM. Diferentes abordagens para a descrição do meio solvente, que vão desde o modelo contínuo polarizável até a inclusão de moléculas explícitas do solvente, são utilizadas. Observamos que a inclusão do solvente desloca o espectro, em relação ao calculado em vácuo, para o vermelho. A inclusão de 20 moléculas explícitas de metanol e 880 representadas como as cargas pontuais do seus átomos para a descrição do meio solvente foi a que melhor concordou com os valores experimentais. Mediante cálculos de mecânica quântica obtivemos para o complexo composto por a molécula de clorofila d e apenas uma de metanol explícita um deslocamento do átomo de magnésio da clorofila d em relação ao anel de 0,31 Å. Mediante a analise da função de distribuição radial de pares obtida da simulação clássica comprovamos que esse átomo de magnésio é penta-coordenado. Além disso, é usada uma estrutura simplificada da clorofila d baseado na localização dos orbitais moleculares participantes das transições eletrônicas com o objetivo de diminuir o custo computacional dos cálculos de mecânica quântica. Os espectros calculados para a clorofila d não apresentaram diferenças significativas com os calculados para a simplificação proposta. Como complementação o espectro Raman da clorofila d isolada é calculado mediante DFT e alguns dos modos normais são caracterizados. / In this work we study the absorption spectrum of chlorophyll d, including the effects of the solvent methanol, using the Time Dependent Density Functional Theory in combination with the method s-QM/MM. Different approaches for the description of the solvent medium, ranging from the polarizable continuum model to the inclusion of explicit solvent molecules, are used. We note that the inclusion of solvent shifts the spectrum, relative to that calculated in vacuum, to the red side of the spectrum. The inclusion of 20 explicit molecules of methanol and 880 represented as point charges of their atoms for the description of the solvent medium was the one that best agreed with the experimental values. By quantum mechanics calculations we obtained for the complex composed of the molecule of chlorophyll d and only one explicit methanol molecule a displacement of the magnesium atom of chlorophyll d in relation to the ring of 0,31 Å. By means of the analysis of the radial distribution function obtained from the classic simulation we can see that this atom of magnesium is penta-coordinated. In addition, a simplified structure of chlorophyll d is used based on the location of the molecular orbitals involved in the electronic transitions in order to reduce the computational cost of quantum mechanics calculations. The spectra calculated for chlorophyll d did not show significant differences with those calculated for the proposed simplification. As a complement the Raman spectrum of isolated chlorophyll d is calculated by DFT and some of the normal modes are characterized.

En nyligen genomförd studie visade att reaktioner mellan vissa radikaler och omättade alkener är snabbare vid rumstemperatur än vad man tidigare har trott. Dessa reaktioner är viktiga för atmosfäriska oxidationscykler och följaktligen var syftet med detta masterprojekt att beräkna hastighetskonstanterna för dessa reaktioner mellan metyljodid och 1-jodidpentan med tetrametyletylen, isopren och limonen vid rumstemperatur genom att kvantifiera respektive epoxid; tetrametyloxiran, isoprenmonoxid och limonen 1,2 epoxid, som producerades. För att uppfylla syftet utfördes experiment på referensföreningarna tetrametyletylen, isoprenmonoxid, limonen och limonen 1,2 epoxid och på prover tagna från en kolonnflödesreaktor. Dessa experiment genomfördes för att kunna utveckla en lämplig provtagningsmetod och analysmetod med termisk desorptionsenhet samt gaskromatografi och masspektrometri (TD-GCMS). Slutsatsen som drogs var att Tenax® TA adsorbentrör är kompatibla med dessa ämnen och att den föreslagna TD-GCMS metoden är effektiv. Dessutom drogs slutsatsen att tetrametyloxiran inte hittades i reaktorproverna (varken i alkenproverna eller reaktorproverna), vilket resulterade i att hastighetskonstanten inte kunde beräknas. Dessutom var kvantifiering av reaktorproverna inte möjlig. / A recent study has shown that the reaction between some radicals and unsaturated alkenes is faster at room temperature than previously believed. These reactions are important for atmospheric oxidation cycles and therefore the purpose of this master project was to measure the rate coefficients for the reactions between methyl iodine and 1-iodopentane with tetramethylethylene, isoprene and limonene at room temperature by quantifying the respective epoxide; tetramethyloxirane, isoprene monoxide and limonene 1,2 epoxide, produced. In order to fulfill the purpose, experiments were conducted using the reference compounds of tetramethylethylene, isoprene monoxide, limonene and limonene 1,2 epoxide and on column flow reactor samples produced in the above mentioned reactions. These were performed in order to be able to develop an appropriate sampling method, and analysis method using thermal desorption unit gas chromatography and mass spectrometry (TD-GCMS). It was concluded that Tenax® TA adsorbent tubes are compatible with these substances and that the TD-GCMS method suggested is appropriate. It was also concluded that no tetramethyloxirane was found in the reactor samples (neither in alkene samples nor after the reactions), resulting in that it was not possible to calculate the rate coefficient. Moreover, the quantification of the reactor samples was not possible.

A collection of hardware weightless Boolean elements has been developed. These form fundamental building blocks which have particular pertinence to the field of weightless neural networks. They have also been shown to have merit in their own right for the design of robust architectures. A major element of this is a collection of weightless Boolean sum and threshold techniques. These are fundamental building blocks which can be used in weightless architectures particularly within the field of weightless neural networks. Included in these is the implementation of L-max also known as N point thresholding. These elements have been applied to design a Boolean weightless hardware version of Austin’s ADAM neural network. ADAM is further enhanced by the addition of a new learning paradigm, that of non-Hebbian Learning. This new method concentrates on the association of ‘dis-similarity’, believing this is as important as areas of similarity. Image processing using hardware weightless neural networks is investigated through simulation of digital filters using a Type 1 Neuroram neuro-filter. Simulations have been performed using MATLAB to compare the results to a conventional median filter. Type 1 Neuroram has been tested on an extended collection of noise types. The importance of the threshold has been examined and the effect of cascading both types of filters was examined. This research has led to the development of several novel weightless hardware elements that can be applied to image processing. These patented elements include a weightless thermocoder and two weightless median filters. These novel robust high speed weightless filters have been compared with conventional median filters. The robustness of these architectures has been investigated when subjected to accelerated ground based generated neutron radiation simulating the atmospheric radiation spectrum experienced at commercial avionic altitudes. A trial investigating the resilience of weightless hardware Boolean elements in comparison to standard weighted arithmetic logic is detailed, examining the effects on the operation of the function when implemented on hardware experiencing high energy neutron bombardment induced single event effects. Further weightless Boolean elements are detailed which contribute to the development of a weightless implementation of the traditionally weighted self ordered map.

A combination of climate change, due to anthropogenic CO2 emissions and concerns over energy security, due to fluctuating fuel prices, has led to the UK pushing to increase its renewable energy production. Harnessing tidal stream energy is an infant sector in the UK’s renewable energy portfolio, despite the UK’s large tidal stream resource, and is harnessed through deploying tidal stream energy converters. This thesis focuses on the design of a novel vertical axis tidal turbine (VATT) called CarBine which is driven by drag force and therefore has several unique advantages, including slow rotational speed, omni-directionality and a simple design. This research focused on the optimisation of the CarBine design and was split into two areas: physical testing and numerical modelling. A conventional Savonius was also analysed in both of these respects and this enabled a direct comparison of CarBine to a competing drag force driven VATT. Physical testing measured the power of the turbines and was conducted in hydraulic flumes at both Cardiff University (CU) and IFREMER in Northern France for a range of flow conditions. Testing at IFREMER enabled the quantification of the blockage effect in the CU experiments. Physical testing resulted in the optimised design of CarBine being one with a four arm configuration. From physical testing at CU, CarBine showed inferior efficiency performance to that of the conventional Savonius, a Cp of 0.117 compared to 0.225 at U∞=0.72 m/s. As a result a hybrid of both the Savonius and CarBine was tested, namely a Savonius with flaps. However, results from physical testing showed the Savonius with flaps to have inferior performance to both CarBine and the conventional Savonius, with a Cp of 0.103 at U∞=0.72 m/s at CU. Numerical modelling was conducted using the commercial CFD software package, Ansys CFX. Both transient and steady state simulations along with 2D and 3D models were used to model both CarBine and the Savonius. Both the k-ε and SST turbulence models were used for comparison. The two degrees of rotational freedom present in the CarBine design resulted in CarBine being difficult to model precisely. The numerical modelling results were validated against the physical testing results and where available, 3D results showed closer validation than the 2D results.

This thesis addresses the architectural integration of transpired solar collectors (TSC), as a building envelope technology patented in 1980s to pre-heat ambient air that would be used for space heating. It explores the reasons for low take up of the technology. It further explores the preferences, perceptions and recommendations of architectural integration quality of TSC in buildings. The research analyses the associated technological innovation development at entrepreneurial level in the UK and North America in a variety of terms including knowledge diffusion and research and development. Building-integrated renewable energy is an important response to concerns about climate change and energy poverty. As space heating accounts for 61% of total domestic energy consumption in countries with long cold seasons, the transpired solar collector (TSC) is a promising technology. However, TSC suffers from low take up despite its apparent technical competitiveness. A large-scale questionnaire, an experimental prototype and technological innovation system analysis were used to provide insight into architecturally integrating and developing TSC technology in buildings, and clarifying its potential contribution to pre-heating ambient air. The research outcomes inferred multi-dimensional reasons behind limited adoption of the technology. Respondents were generally aware of TSC technology; however, few were satisfied with available technology. Various preferences determining selection of TSCs were investigated, including: ‘invisible’ integration, planning guidelines for traditional buildings, stage of integration and sustainable factors. Respondents indicated that the ultimate feature considered when sourcing TSC technology was its reliability followed by capital cost. The solar irradiation only needed to exceed 60W/m2 for TSC to generate an output temperature greater than the ambient temperature. A significant temperature increase was observed when solar irradiation exceeded 400W/m2. Output temperature increased to 16ºC above ambient temperature in autumn and 12ºC in winter in the TSC prototype. A comparison of relevant actors, institutions and networks of TSC in the United Kingdom (UK) with North America, found both to be cautious about communication to protect intellectual property: this hampers knowledge exchange and development. Despite TSC take up in North America being restricted by cheap gas prices, end-user feedback reflects a level of satisfaction versus fewer such examples in the UK. Identified barriers included immaturity of technology, reluctance to implement new technology, lack of supply chain and low institutional support. A framework of potential enablers and architectural design guidelines were proposed to breakthrough take up of TSC.

Many households in developing countries rely on biomass (wood, charcoal, agricultural wastes, sawdust, and animal dung) and coal to meet their energy needs. The burning of these fuels in open fires creates environmental problems one of which is indoor air pollution (IAP). For effective reduction of indoor air pollution in sub-Saharan Africa, it is therefore, important to understand factors that determine the choice and uptake of cleaner fuels for household energy use. This research investigates the salient factors influencing households in developing countries in choosing fuel types, using the households in peri-urban areas of Ado Ekiti, Ekiti State, Nigeria as a case study. This research used holistic approaches to understand energy issues in the study area and used methods such as questionnaires, interviews, and field observation during data collection. Key findings suggest that underlying socio-cultural contexts of households’ ethnic groups guided wood-fuel harvesting in the peri-urban areas of Ado Ekiti, Ekiti State, Nigeria. Wood fuel continues to be households’ main domestic energy source irrespective of their socio-economic status. The open burning of wood fuel causes indoor air pollution as the recorded 24-hour particulate matter levels was between 42µg/m3 – 275µg/m3 for indoor kitchens and 48µg/m3 – 648µg/m3 for outdoor kitchens. The cultural perception of the households that natural aeration blows particulates into buildings hinders them from believing that the open of burning of biomass fuels for domestic activities is the cause of indoor air pollution. Based on the findings of this study, it is argued that the traditional norms and values of the householders, being embedded in their socio-cultural contexts, are vital for understanding energy issues in the global South.

This research investigated novel decontamination methods of airborne microorganisms in enclosed public spaces. There are many ways the pathogenic micro-organisms can be transmitted from one body to another, which includes for example, physical contact between the contaminated surface to another, transfer of infected blood from a donor to another medium, or respiratory infections where the large droplets containing micro-organisms caused by talking, sneezing or coughing can infect another whether by direct or close contact, and airborne transmission where the tiny aerosol droplets containing the micro-organisms remain in the air for a long period of time thus spreading to wider areas, making this mode of transmission the most effective and thus dangerous. There are many technique and systems in the market today in the field of air cleaning, and many more under development, these include: ozone, plasma, UV, IR, microwave irradiation, passive solar exposure, pulsed light, electrostatic precipitation, photo-catalytic oxidation etc. However air decontamination using a laser is an unexplored approach. In general two different mechanisms are studied in detail in this research. The possibility of using radiation from the laser and also using plasma and its bi-products were investigated. Many variations and techniques were evaluated for both mechanisms to optimise each decontamination effect. Two types of lasers were used to investigate the concept of using lasers to decontaminate air: a CO2 laser producing a beam at 10.6 μm in the IR region and a KrF excimer laser producing a beam at 248 nm in the UV region. This research was to investigate and make use of the power that is available in the laser in a certain way to decontaminate the air. The effect of laser beam absorption in the presence of microorganisms was modelled in Matlab and this could be used to analyse any wavelength. Two variations of creating a plasma were investigated, one method used a Chang profiled, uniform field electrode and the other used an increased size flat electrode. The plasma produced from these systems emitted radiation around 200 nm to 900 nm. The Chang profiled electrode, which was manufactured in house, was originally designed to be used as a Nitrogen air laser. However, experiments with a purchased Nitrogen laser (detailed in Chapter 3) did not show any significant bacterial killing so the system was modified to be used as a plasma air decontamination device. The electrode was sized 60 mm x 10 mm, and the discharge volume was varied by altering the discharge gap. The effects of various parameters were investigated including: the discharge voltage, type of pre-ionisers to optimise the discharge and air flow shaping through the discharge region. Microbiological experiments conducted using air seeded with microorganisms was used to test the system’s decontamination efficiency. The second plasma system used larger 200 mm x 30 mm aluminium electrodes. Again various parameters were investigated to maximise the discharge stability which included, type of dielectric medium, type of power source, electrical circuit setup, use of laser marked electrodes, air flow shaping and using multiple electrode pairs running off the same power supply. Again, microbiological experiments conducted using air seeded with microorganisms was used to test the system’s decontamination efficiency. Two further systems were built using the results obtained from testing the 200 mm x 30 mm aluminium electrodes, an Industrial Based Air Decontamination Unit and a Ozone Shock Plasma System. Both systems were comprised with multiple pairs of laser marked electrodes with dielectric media and possible addition of flow shaping. The two systems were tested as before with good effect. The developed prototypes can be applied to most applications where air cleanliness is required.