As redes de sensores sem fio (wsns) têm ganhado cada vez mais espaço no monitoramento e controle de processos na indústria. Dentro destas redes, os dispositivos são alimentados por baterias, e a comunicação é feita por radiofrequência. Por conta disto, os rádios dos dispositivos são responsáveis por consumir boa parte da energia armazenada nas suas baterias, e a comunicação dos dispositivos está sujeita à interferência provinda de outras redes e do maquinário industrial. Para sanar estes problemas podem ser empregadas técnicas de controle de potência de transmissão (cpt). Existem diversas técnicas de cpt na literatura, visando os mais diversos objetivos, desde economia de energia e redução de interferência, até controle da topologia da rede. Este trabalho apresenta uma proposta de emprego de (cpt) em uma rede de sensores sem fio através da utilização de controladores proporcionais-integrais (pi). Juntamente com a técnica proposta, são apresentados um procedimento para projeto dos controladores e alguns algoritmos desenvolvidos para o caso ideal e para os casos com saturação dos níveis de potência disponíveis. Este trabalho se diferencia dos trabalhos encontrados na literatura por apresentar uma técnica de controle linear e que depende apenas de informações já disponíveis em cada dispositivo cuja potência será ajustada. Deste modo, esta técnica pode ser empregada em conjunto com protocolos industriais mais restritivos quanto às informações que podem ser trocadas nas mensagens. Além disso, esta técnica reduz ainda mais o consumo e a interferência por evitar transmissões desnecessárias. A proposta apresentada foi validada através de simulações e de um experimento com dispositivos WirelessHART reais, apresentando bons resultados e provando que é possível controlar a potência sem a necessidade das informações extras. / Wireless sensor networks (wsns) are being increasingly adopted in monitor and control tasks in the industry. The devices within these networks are battery-powered, and they communicate through radio frequency. Therefore the radios of the devices account for the most of the consumption of the energy stored in the batteries, and the devices’ communication is subject to interference from other networks and industrial machinery. Transmission power control (tpc) techniques can be employed to cope with these problems. There are several tpc techniques in the literature, aiming at a wide range of objectives, from energy saving and interference reduction, to network topology control. This work presents the proposal of a (tpc) technique in a wireless sensor network that works by employing proportional-integral (pi) controllers. Besides the technique itself, a procedure is presented to design the controllers along some algorithms developed to the ideal case, and the case when there is saturation in the available power levels. This work, unlike the other works found in the literature, presents a linear technique that depends only on information that is already available in each device whose power needs to be adjusted. Therefore, the proposed technique can be employed together with more restrictive industrial protocols that limit the information that can be exchanged in the messages. Besides, it further reduces the power consumption and the interference by avoiding unnecessary transmissions. The proposal was validated through simulations and an experiment using real WirelessHART devices, presenting good results and proving that it is possible to adjust the transmission power without necessarily using the extra information.

Em colônias de insetos eussociais, é prevista uma demanda conflitante entre a produção de operárias e indivíduos reprodutivos, visto que operárias realizam tarefas essenciais para a sobrevivência da colônia, enquanto machos e rainhas estão relacionados com a reprodução. Nesse trabalho, foram testadas as hipóteses (1) que a produção de sexuados estaria diretamente relacionada com a disponibilidade de recursos alimentares e (2) que haveria uma regulação temporal da produção de sexuados, com épocas mais favoráveis à produção de reprodutivos (verão) e menos favoráveis (inverno). O sistema de estudo foi a abelha sem ferrão Scaptotrigona aff. depilis e foram realizados dois experimentos. No primeiro experimento, na estação de verão, foram montadas quinze colônias padronizadas e sorteadas em cinco grupos experimentais. Os grupos A2 e C2 receberam o dobro de alimentação artificial (xarope de açúcar e pólen apícola) do que os grupos A1 e C1. As colônias dos grupos C2 e C1 foram mantidas confinadas, enquanto as colônias dos grupos A2 e A1 podiam forragear livremente. O grupo A0 (controle) não recebeu alimentação artificial e as colônias permaneceram abertas. No inverno, o mesmo experimento foi realizado, porém apenas com os grupos com colônias abertas. No experimento 2, a quantidade de pólen estocado nas colônias foi manipulada. As colônias do grupo Co não foram manipuladas e apresentaram em média 44 potes de pólen, as colônias do grupo A receberam em média 96 potes e as colônias do grupo B, 12 potes. No experimento 1, para o verão, foi encontrado um efeito significativo do confinamento, porém, nas duas estações, não houve efeito da quantidade de alimento sobre a produção de sexuados. Nas duas estações, verificou-se grande variação dentro dos grupos e a produção de machos foi dominada por poucas colônias. Não houve diferenças em relação à produção de sexuados entre as estações. No inverno, a produção de machos e células reais foi correlacionada positivamente com a quantidade de potes de alimento nas colônias. No experimento 2, apesar das diferenças iniciais quanto ao alimento armazenado, houve uma rápida recuperação dos estoques de alimento, principalmente pelo grupo B. Não foi verificada diferença na produção de sexuados devido ao tratamento experimental, porém, a produção de machos foi correlacionada com o número de potes de pólen nos ninhos, como no experimento 1. Considerando esses resultados em conjunto, não foi possível refutar as hipóteses de efeito positivo da quantidade de recursos alimentares e de efeito da sazonalidade sobre a produção de sexuados em S. aff. depilis. / In colonies of eusocial insects, it is expected a trade-off in resource allocation between worker and sexual offspring production, as workers perform tasks essential to colony\'s survival, while males and queens are associated with reproduction. In this study, we tested the following hypotheses: (1) that sexual offspring production would be directly related to food resources availability and (2) that there would be a temporal regulation of sexual offspring production, with a favorable season to reproductives production (summer) and a less favorable season (winter). The study system was the stingless bee Scaptotrigona aff. depilis and two experiments were conducted. In the first experiment, in summer, fifteen standardized colonies were set up and randomly assigned into five groups. Groups A2 and C2 received twice the amount of artificial food (sugar syrup and Apis mellifera pollen) than colonies from groups A1 and C1. Colonies from groups C2 and C1 were kept confined, while colonies from groups A2 and A1 could forage freely. The control group A0 did not receive any artificial food and the colonies remained open. In the winter the same experiment was carried out, only with groups with open colonies. In experiment 2, the amount of pollen stored in the colonies was manipulated. The colonies of group Co were not manipulated and presented a mean number of 44 pots of pollen, colonies from group A received 96 pots and colonies from group B 12 pots (mean). In summer (experiment 1), there was a significant effect for confinement, however for both seasons, there was no effect for food amount on sexual offspring production. For both seasons, there was a large intra-group variation and a few colonies were responsible for major male production. There was no difference on sexual offspring production between seasons. In winter, the production of males and royal cells was positively correlated with the amount of food pots in the colonies. In experiment 2, even though there was an initial difference in relation to food stores, a fast recovery on food storage was observed, specially for group B. There was no difference on sexual offspring production due to experimental treatment, however male production was correlated with the number of pollen pots, as in experiment 1. Considering these results together, it was not possible to refute the hypotheses of the positive effect of amount of food resources and the effect of seasonality on the production of sexual offspring in S. aff. depilis.

A artroscopia tem função diagnóstica e terapêutica na doença articular. Mesmo com as modalidades de imagem mais modernas, ainda é considerada como padrão ouro no diagnóstico de problemas articulares em equinos. Sabe-se que as características físico-químicas das diferentes soluções de infusão podem determinar alterações estruturais na superfície da cartilagem. Apesar da existência de estudos baseados na busca de um fluido ideal para irrigação durante a artroscopia, com principal foco nas características bioquímicas do líquido, poucos trabalhos testaram características físicas destes fluidos, como a temperatura. Na primeira etapa deste trabalho foram avaliadas 24 articulações de ovinos submetidas à irrigação articular com solução de Ringer com lactato condicionado a quatro diferentes temperaturas (5, 12, 25 e 38 ºC). Para avaliação de cada grupo foram coletadas biopsias comparativas de membrana sinovial e de cartilagem com osso subcondral da articulação femoropatelar visando análise histológica e por microscopia eletrônica de varredura, respectivamente, imediatamente antes do início da infusão do líquido e após uma hora de infusão. Apesar de alterações na ultraestrutura da superfície articular terem sido observadas após lavagem das articulações, nenhuma diferença estatística entre os grupos foi identificada. Na segunda etapa do experimento foram testadas as temperaturas 5, 25 e 38 °C do Ringer com lactato utilizado para irrigação articular durante procedimentos artroscópicos em 12 articulações radiocárpicas de seis equinos. As articulações foram divididas em três grupos de quatro, sendo avaliados, além da membrana sinovial e cartilagem, o líquido sinovial previamente ao início da infusão com fluido condicionado e 12, 24 e 48 horas após o término da irrigação, visando análise comparativa das concentrações de IL-1β, PGE2, TNF-α, condroitim sulfato (CS) e ácido hialurônico (AH). As alterações da superfície articular dos equinos decorrentes da irrigação também foram independentes da temperatura utilizada. Houve um aumento significativo das concentrações de PGE2 e IL-1β no líquido sinovial às 12 horas em todos os grupos, exceto para IL-1β no grupo de articulações irrigadas com fluido a 38 °C, que não apresentou alteração nas concentrações. A análise de TNF-α não revelou diferença significativa entre os grupos. As concentrações de CS aumentaram às 24 horas nos três grupos e foi estatisticamente maior no grupo irrigado a 38 °C. Não houve diferença significativa das concentrações de AH no líquido sinovial do grupo de articulações irrigadas a 25 °C, o que não ocorreu nos grupos 5 e 38 °C, havendo diminuição às 24 e 12 horas, respectivamente, retornando aos valores basais na coleta subsequente. As biopsias de membrana sinovial coletadas em ambas as etapas do experimento não demonstraram alteração estrutural ou migração celular que inferissem em resposta inflamatória ao insulto. As alterações da ultraestrutura da superfície da cartilagem estão mais relacionada ao fator mecânico da passagem do líquido que à temperatura de acondicionamento. Apesar de mais análises serem necessárias para definição da melhor temperatura a ser utilizada durante as artroscopias, a detecção de menores concentrações de IL-1β nas articulações de equinos irrigadas com Ringer com lactato a 38 °C sugerem de que essa seja a temperatura menos deletéria para o ambiente articular. / Arthroscopy has a diagnostic and a therapeutic function in joint disease. Even with modern imaging modalities, it is still considered the gold standard for diagnosing equine joint problems. It is known that the physicochemical characteristics of different infusion solutions could influence structural modifications on cartilage surface. A number of studies have described the search for the ideal fluid to be used for irrigation during arthroscopy, focusing on the biochemical characteristics of the various liquids. However, few works have taken temperature into consideration when studying the physical characteristics of these fluids. Therefore, in the first phase of this study four different temperatures of Ringer lactate used for articular irrigation were assessed into four groups of six ovine joints each (5, 12, 25 and 38 ºC). To evaluate each group, comparative synovial membrane and osteochondral samples were collected from the patellofemoral joints for histological analysis and Scanning Electron Microscopy, respectively, immediately before and 1 hour after starting fluid infusion. Ultrastructural changes of the joint surfaces after irrigation were observed, but no statistical differences between groups were identified. In the second phase of this study, lactated Ringers solution was assessed at three different temperatures: 5, 25 and 38°C, for irrigation of 12 radiocarpal joints of six horses during arthroscopy. Three groups of four joints were studied to evaluate synovial membrane, cartilage and synovial liquid immediately before and 12, 24 and 48 hours after joint irrigation. These samples were subjected to comparative analysis of IL-1&beta, PGE2, TNF-&alpha, condroitin sulfate (CS) and hyaluronic acid (HA) concentrations. Changes of equine joint surfaces were also independent of temperature. There was a significant increase in the PGE2 and IL-1β concentrations in the synovial liquid at 12 hours in all groups except for IL-1β on the joints irrigated with fluid at 38°C, which did not show concentrations changes. There was no statistical difference of TNF-&alpha between groups. CS concentrations had a significant increase at 24 hours in all groups, meanwhile in the 38 °C group this increased was statistically greater. There was no statistical difference for HA concentrations on synovial liquid of the irrigated joints at 25 °C. In the 5 and 38 °C groups there were synovial fluid HA decrease at 24 and 12 hours, respectively, returning to basal values at the subsequent collect. The synovial membrane biopsies collected in the both steps of this study did not show any structural alterations or cellular migration that might interfere in response to inflammatory insult. Ultrastructural changes in articular most superficial zone are more related to mechanic action of fluid lavage than irrigation solutions temperature. Although more tests needs to be done, the lowest concentrations of IL-1β in equine joints irrigated with Ringer lactate at 38 °C give some evidence that this is the less deleterious temperature to articular environment.

Neste trabalho se pesquisou a identificação por subespaços para modelos de sistemas lineares invariantes no tempo em espaço de estados operando em tempo discreto, aplicado a sistemas em malha aberta e malha fechada. Dentro da identificação em malha aberta foram estudados os casos determinístico e estocástico determinístico para os métodos MOESP e N4SID. Como resultado deste estudo se apresentou um novo método, MON4SID, que usa a técnica MOESP para encontrar a matriz de observabilidade estendida e N4SID para recuperar as matrizes do sistema, a partir dos dados de entrada e saída. Duas variantes do método MON4SID são apresentadas para o caso determinístico e uma para determinístico - estocástico. Para verificar seu desempenho, este método foi aplicado a três tipos de processos: processo MIMO, sistema SISO e um processo benchmark MIMO da Shell. Foram usados nove algoritmos para identificar os diferentes processos e seus resultados foram comparados. Em todos eles o método MON4SID teve um bom desempenho. Para o caso de identificação em malha fechada, foram estudados os métodos MOESPC e N4SIDC para malha fechada. Estes métodos surgem como uma extensão dos métodos aplicados para malha aberta, mas a forma de solucionar o problema para malha fechada é diferente, por exemplo, o método MOESP computa um sistema global a partir do qual as matrizes da planta e do controlador são estimadas, através de uma redução de ordem e o método N4SID computa as matrizes da planta através do problema de mínimos quadrados, mas é necessário conhecer os parâmetros de Markov do controlador. Como resultado deste estudo foi apresentado o método MON4SIDC, o qual se baseia no método MON4SID para malha aberta. Este novo método usa a técnica MOESP para computar o sistema global e depois as matrizes da planta são estimadas por meio do método dos mínimos quadrados. Neste método não é necessário ter nenhum conhecimento do controlador. Um sistema simulado é usado para avaliar o desempenho do algoritmo MON4SIDC e seu resultado é comparado com outros algoritmos existentes na identificação para malha fechada PEM, N4SIDC, ARXS e MOESPC. O método MON4SIDC teve um bom desempenho, inclusive para sistemas com ruído, o que não aconteceu para o caso PEM e ARXS. / In this work it was researched subspace identification for models of linear time invariant systems in state space operating in discrete time, applied to open and closed loop systems. In the open loop identification the deterministic and stochastic - deterministic cases were studied for the methods MOESP and N4SID. As a result of this study a new method MON4SID is presented, which uses the technique MOESP to find the extended observability matrix and N4SID to compute the system matrices, from a set of input-output measurements. Two variants of the method MON4SID are presented for the case deterministic and one for deterministic - stochastic. To verify its performance, this method was applied to three types of processes: process MIMO, system SISO and a MIMO benchmark process of Shell. Nine algorithms were used to identify the different processes and their results are compared. In all of them the method MON4SID had a good performance. For the closed loop identification, the methods MOESPC and N4SIDC were studied. These methods appear as an extension of the methods applied for open loop identification, but the form of solving the problem for closed loop is different. For instance, the method MOESP computes a global system from which the plant matrices and controller matrices are computed through an order reduction and the method N4SID computes the plant matrix through the problem of least squares, but it is necessary to know the Markov parameters of the controller. As a result of this study the method MON4SIDC was presented, which uses the method MON4SID for open loop. This new method uses the technique MOESP to compute the global system and the plant matrices are estimated through the problem of least squares. In this method it is not necessary to have any knowledge about the controller. A simulated system is used to evaluate the performance of the algorithm MON4SIDC and its results are compared with other existent algorithms for closed loop identification: PEM, N4SIDC, ARXS and MOESPC. The method MON4SIDC presented a good performance, even with systems with noise, what did not occur with PEM and ARXS.

Planejamento probabilístico lida com a tomada de decisão sequencial em ambientes estocásticos e geralmente é modelado por um Processo de Decisão Markoviano (Markovian Decision Process - MDP). Um MDP modela a interação entre um agente e o seu ambiente: em cada estágio, o agente decide executar uma ação, com efeitos probabilísticos e um certo custo, que irá produzir um estado futuro. O objetivo do agente MDP é minimizar o custo esperado ao longo de uma sequência de escolhas de ação. O número de estágios que o agente atua no ambiente é chamado de horizonte, o qual pode ser finito, infinito ou indefinido. Um exemplo de MDP com horizonte indefinido é o Stochastic Shortest Path MDP (SSP MDP), que estende a definição de MDP adicionando um conjunto de estados meta (o agente para de agir ao alcançar um estado meta). Num SSP MDP é feita a suposição de que é sempre possível alcançar um estado meta a partir de qualquer estado do mundo. No entanto, essa é uma suposição muito forte e que não pode ser garantida em aplicações práticas. Estados a partir dos quais é impossível atingir a meta são chamados de becos-sem-saída. Um beco-sem-saída pode ser evitável ou inevitável (se nenhuma política leva do estado inicial para a meta com probabilidade um). Em trabalhos recentes foram propostas extensões para SSP MDP que permitem a existência de diferentes tipos de beco-sem-saída, bem como algoritmos para resolvê-los. No entanto, a detecção de becos-sem-saída é feita utilizando: (i) heurísticas que podem falhar para becos-sem-saída implícitos ou (ii) métodos mais confiáveis, mas que demandam alto custo computacional. Neste projeto fazemos uma caracterização formal de modelos de planejamento probabilístico com becos-sem-saída. Além disso, propomos uma nova técnica para detecção de becos-sem-saída baseada nessa caracterização e adaptamos algoritmos de planejamento probabilístico para utilizarem esse novo método de detecção. Os resultados empíricos mostram que o método proposto é capaz de detectar todos os becos-sem-saída de um dado conjunto de estados e, quando usado com planejadores probabilísticos, pode tornar esses planejadores mais eficientes em domínios com becos-sem-saída difíceis de serem detectados / Probabilistic planning deals with sequential decision making in stochastic environments and is modeled by a Markovian Decision Process (MDP). An MDP models the interaction between an agent and its environment: at each stage, the agent decides to execute an action, with probabilistic effects and a certain cost which produces a future state. The purpose of the MDP agent is to minimize the expected cost along a sequence of choices. The number of stages that the agent acts in the environment is called horizon, which can be finite, infinite or undefined. An example of MDP with undefined horizon is the Stochastic Shortest Path MDP, which extends the definition of MDP by adding a set of goal states (the agent stops acting after reaching a goal state). In an SSP MDP the assumption is made that it is always possible to achieve a goal state from every state of the world. However, this is a very strong assumption and cannot be guaranteed in practical applications. States from which it is impossible to reach the goal are called dead-ends. A dead-end may be avoidable or unavoidable (when no policy leads from the initial state to the goal with probability one). Recent work has proposed extensions to SSP MDP that allow the existence of different types of dead-ends as well as algorithms to solve them. However, the detection of dead-end is done using: (i) heuristics that may fail to detect implicitly dead-ends or (ii) more reliable methods that require a high computational cost. In this project we make a formal characterization of probabilistic planning models with dead-ends. In addition, we propose a new technique for dead-end detection based on this characterization and we adapt probabilistic planning algorithms to use this new detection method. The empirical results show that the proposed method is able to detect all dead-ends of a given set of states and, when used withprobabilistic planners, can make these planners more efficient in domains with difficult to detect dead-ends.

The need for online banking technology in the banking industry is important to allow financial institutions to serve their customers worldwide, without having the need to be present in person or face-to-face to benefit from the service. Despite the investment in informational technology and information system infrastructure by Saudi Arabian financial institutions, the Saudi banks have lagged their Western counterparts when it comes to provision of online banking services. Given a relatively recent adoption of online banking in Saudi Arabia, consumer trust in online banking is a critical challenge facing bank managers, warranting further research. The aim of this research is to develop a framework to improve consumer trust toward online banking services and its affect consumer intentions to use the online banking service and e-WOM. The literature included the assessment of relevant theories including social cognitive theory, technology acceptance model and commitment trust theory. These theories formed the basis of formulation of research framework, including development of 12 research hypotheses. Perceived usefulness, perceived ease of use, relationship termination cost, shared value, communication, privacy and demographic factors all have an important role in influencing the extent of trust and the subsequent intention of customers to engage in and use online banking services provided by the financial institutions. When it comes to the literature gap, there remains a relative lack of existence of research on the subject of consumer trust in online banking within Saudi Arabia (Zhou, 2012; Alanezi and Brooks, 2014; AL-Malkawi et al., 2016), which presents a gap in the literature warranting further research. Moreover, most of the prior research on the subject of consumer trust in online banking has concentrated on the information cues such as reputation and information quality (Montazemi and Qahri-Saremi, 2015). This is alongside relatively little attention given to other factors such as perceived usefulness, ease of use, shared value, and privacy/security, which are crucial factors in online banking services (Fatima, 2011; Aloul., 2012; Montazemi and Qahri-Saremi, 2015). Regarding methodology, the positivist research philosophy, deductive approach, survey questionnaire and quantitative data collection and analysis techniques were undertaken. A key rationale for selection of such a methodology is the review of relevant literature, which led to development of research hypotheses that are tested through the survey technique, which is consistent with positivist and deductive research approach. The survey questionnaire request was sent online to 800 research participants (users of online services in Saudi Arabia). Out of these 800, 585 responded (indicating a response rate of an impressive 73%). The response rate was improved through giving regular reminders to the research participants who had not responded to the survey earlier. The findings of this research support the argument that trust in e-bank website play an important role in maintaining long term relationship with customers. Therefore, online banks who deal with their customers in a confidential, transparent and honest manner and ultimately protect the consumers' interests are likely to contribute to greater adoption of online banking by customers in Saudi Arabia. Furthermore, it is also concluded that perceived ease of use, trust in online banking website, trust in technology, relationship termination cost, privacy/security, shared value, and communication have positive and significant effect on customer trust in e-bank website, intention to use online banking, and e-WOM.

Organisations are becoming increasingly aware of the necessity to maintain sustainable long-term relationships with customers in order to survive in the global competition. They are also aware that the changing needs and purchase patterns of customers requires them to choose differentiated customer-oriented marketing strategies so as to acquire a competitive advantage over their rivals and enhance their business performance. Customer Relationship Management (CRM) enables organisations to create and manage relationships with customers more effectively through a detailed and accurate analysis of consumer data using various information technologies. Several CRM theories like the resource-based view (RBV), and theories of institutions, cultures, entrepreneurship, and dynamic theory can help a company gain over competitors. If implemented appropriately, the CRM approach can help a firm with managerial efficiency, cost reduction, enhanced customer services, and increased sales and profits. The present study aims to develop a novel and comprehensive model to measure the effect of CRM resources over CRM capabilities and the effects on business performance. The present study covers infrastructural and cultural CRM resources with CRM capabilities. The results are based on information collected from three Kuwaiti mobile network operators using a questionnaire in adherence with ethical guidelines. The study measures business performance comprehensively from financial and marketing perspectives using regression analysis to determine if there is a mediation role between two variables. The results show that CRM infrastructural resources positively and directly affect CRM capabilities. However, the effect of customer and learning orientation cultures on CRM capabilities is considerably stronger than that of infrastructural resources. The study also reveals that CRM capabilities significantly and positively affect business performance from marketing and financial standpoints although the effect on marketing performance was stronger.

The surface and structural change of human hair fibre have been analysed to determine the oxidation effects for bleached hairs. Three types of bleached hairs (6% H2O2 bleach, 9% H2O2 commercial bleach and commercial persulphate bleach (contains 9% H2O2)) as well as virgin hair were evaluated with the increasing treatment time using Scanning Electron Microscopy (SEM), Reflective Spectrophotometry, Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared (FTIR) Spectroscopy. It is obvious that longer treatment times result in the greater surface and structural damage. However, commercial persulphate bleach causes less surface damage for the cuticle. 6% H202 bleach has overall moderate damage effects on both cuticle and cortex over the treatment time. 9% H2O2 commercial bleach indicates two different damage stages. The first 1.5h bleached hairs show mild oxidation to the surface, whereas the damage becomes heavy after 2h. This phenomenon results in that 9% H2O2 commercial bleach has a more intensive oxidation damage in the cortex than the commercial persulphate bleach. This is in line with DSC investigation which shows that the intermediate filament of 9% H2O2 commercial bleach is heavily damaged after the extensive oxidation time (greater than or equal to2h). Although commercial persulphate bleach contains the stronger oxidising agent, it has a less surface damage than 9% H2O2 commercial bleached hair in FTIR-ATR measurement, and a similar oxidation effect on the matrix as 6% H202 bleached hair in FTIR transmission investigation. In addition, it has been verified by colour measurements that bleached hairs have an overall lighter, yellowish and reddish colour. Consequently, commercial persulphate bleached hair is much lighter and more yellow than 9% H2O2 commercial bleached hair and 6% H202 bleached hair. DSC investigations reveal that the three bleaches have a homogenous oxidation effect on IFs and IFAPs. The deconvolution results using three Gaussian distributions confirm this observation. The stronger bleach results in a homogenous structural damage on both para- and ortho-cortex with increasing bleaching time. Commercial persulphate bleach and 9% H2O2 commercial bleach have a progressive damage effect on the ortho- and para- cortex than 6% H202 bleach. Kinetics analysis is conducted for the virgin and bleached hairs by using various heating rates according to ASTM-E698. The activation energies of 260 kJ/mol for the virgin hair and 295 kJ/mol for the commercial persulphate bleached hair (2h) are determined from the slope of the regression line of peak temperature, TD (as 1/TD) and heating rate, β (as lnβ) on the basis of the Arrhenius-equation. The predominant structural damage for various heating rates only occurs in the IF. It is shown that a linear increase in DeltaHD occurs for lower heating rates, while it is constant for higher heating rates. This can be ascribed to the hypothesis that a lower heating rate favours a crystal transformation change (alpha-β transformation), while a higher rate favours a crystalline-amorphous transformation. SEM examines the morphological changes of hair samples after DSC. The cortex has been dissolved at the lower heating rate. The commercial persulphate bleached hairs (2h) show an overall shrunk cuticle surface and fewer and smaller hydrolysed protein granules, due to the previous damage of the alpha-helix in the cortical cell.

This thesis addresses existing shortcomings in the co-creation literature by proposing organisational capabilities that support co-creation in financial service firms. A developing country perspective is taken and the context is Nigeria, a West African Country. In this thesis, the Resource-based view and Knowledge-based view are integrated with the Dynamic Capability perspective to identify capabilities required to manage the dyadic interactions during co-creation. First, a conceptual model is developed through an in-depth literature review, before testing, refining and validating the model through a mixed-method research approach, involving both qualitative and quantitative research steps. The conceptual model identified a set of capabilities - namely the firm's innovation, knowledge management and relational capability and their effect on co-creation practice. The aim of the qualitative research step was to improve the conceptual model through exploratory research. This step involved in-depth interviews (n=9) with key informants and a focus group discussion with users (n=7). In the quantitative step, empirical data was collected via a questionnaire (n=261) using a drop-off-pick-up (DOPU) technique. The data is analysed using structural path analysis, hypotheses testing and model re-specification. The results of the qualitative phase indicate that co-creation in financial services is dependent on regulation, user need and the structure of financial services in Nigeria. The results also confirm the influence of innovation, knowledge management and relational capabilities on co-creation practice. Nevertheless, qualitative findings also show that knowledge management capability emerged as a vital capability upon which other value creation activities in financial service firms depend. These findings were further tested and validated in the quantitative phase. In line with the resource-based view (RBV) and the knowledge-based view (KBV), empirical findings confirm that the firm`s resource endowments explain, in part, value co-creation in firms. Principally, the findings of this study show that the capacity of financial service organisations to provide sustainable value creation for its clients and itself depend on the degree to which they possess specific dynamic capabilities. The findings also show the relative importance of co-creation practices and how they are effective only in certain conditions and specific environments.

In this work, the nucleation and growth of pores in anodic films formed on aluminium in chromic acid and the effect of low levels of sulphate impurity in the anodizing bath on the formation of the films on aluminium and AA 2024 alloy are investigated. The sulphate concentrations considered include levels within specified limits for industrial processing. The anodizing is carried out either potentiostatically or by stepping the voltage. The films are examined by scanning electron microscopy, transmission electron microscopy and atomic force microscopy to determine the pore spacing, pore population densities, pore diameters and film thicknesses. Film compositions were determined using energy-dispersive X-ray spectroscopy, Rutherford backscattered microscopy and nuclear reaction analysis. In order to investigate the mechanism of pore formation, two tracer methods are employed. In one method, anodic films are formed first in an arsenate electrolyte in the second method, a tungsten tracer band deposited by magnetron sputtering. The behaviours of arsenic and the tungsten are investigated during the subsequent anodizing in chromic acid. The results suggest that the initiation and growth of pores in occurred as a result of electric field assisted chemical dissolution. The effect of sulphate impurity in the chromic acid is investigated using electrolytes with different sulphate content. In the initial stages of anodizing aluminium at 100 V, sulphate impurity at a level of 38 ppm in the chromic acid is shown to lead to significant incorporation of sulphate ions into the anodic film, a lower current density, a smaller cell size and less feathering of the pore walls. In addition, the efficiency of film formation is increased. In later stages of anodizing, the growth of larger pores and cells, leads to a duplex film morphology, with finer pores in the outer region. The change in pore size correlates with a reduction in the incorporation of sulphate into the film. From the results of sequential anodizing experiments, it is suggested that incorporated sulphate ions generate a space charge layer, which has an important role in determining the current density. The effects of higher sulphate concentrations up to 3000 ppm are investigated, which are shown to significantly affect the current density and the pore diameter. Anodizing of aluminium and AA 2024 alloy was also carried out according to industrial practice. The results show that there is significant effect of sulphur impurity on the film thickness. Corrosion tests in 3.5 % NaCl solution for the alloy after anodizing in low (smaller or equal to 1.5 ppm) and high (~38 ppm) sulphate-containing chromic acid electrolytes demonstrate a better corrosion resistance with films formed in the latter electrolyte.