With an increased urgency for global action towards climate change mitigation, this research was undertaken with the aim of evaluating post-combustion CO2 capture as an emission abatement strategy for gas-fired power plants. A dynamic rate-based model of a capture plant with MEA solvent was built, with imposed chemical equilibrium, and validated at pilot scale under transient conditions. The model predicted plant behaviour under multiple process inputs and disturbances. The validated model was next used to analyse the process and it was found that CO2 absorption is mass transfer limited. The model was then improved by explicitly adding reactions rate in the model continuity, the first such dynamic model to be reported for the capture process. The model is again validated and is observed to provide better predictions than the previous model. Next, high fidelity models of a gas-fired power plant, a scaled-up capture plant and a compression train were built and integrated for 90% CO2 capture. Steam for solvent regeneration is extracted from the power plant IP/LP crossover pipe. Net efficiency drops from 59% to 49%, with increased cooling water demand. A 40% exhaust gas recirculation resulted in a recovery of 1% efficiency, proving that enhanced mass transfer in the capture plant reduces solvent regeneration energy demands. Economic analysis reveals that overnight cost increases by 58% with CO2 capture, and cost of electricity by 30%. While this discourages deployment of capture technology, natural gas prices remain the largest driver for cost of electricity. Other integration approaches – using a dedicated boiler and steam extraction from the LP steam drum – were explored for operational flexibility, and their net efficiencies were found to be 40 and 45% respectively. Supplementary firing of exhaust gas may be a viable option for retrofit, as it is shown to minimise integrated plant output losses at a net efficiency of 43.5%. Areas identified for further study are solvent substitution, integrated plant part load operation, flexible control and use of rotating packed beds for CO2 capture.

Le but principal de ce projet doctoral est de déterminer le potentiel d'amélioration de l'efficacité énergétique du système de captage de carbone dans les stations thermiques de production d'électricité, par l'intégration optimale des éjecteurs monophasiques. Il s'agit du système de captage postcombustion du dioxyde de carbone (CO2) par absorption/désorption utilisant la monoéthanolamine (MEA). Les éjecteurs intégrés utilisent des rejets thermiques de 100 °C qu'on retrouve dans les stations thermiques de production d'électricité. La revalorisation de ces rejets permet la substitution partielle de vapeur de turbine à coût élevé, qui serait autrement prise de la centrale thermique. Le deuxième objectif de la thèse est d'évaluer expérimentalement la performance d'un éjecteur à vapeur où le fluide secondaire de l'éjecteur est un mélange de vapeur d'eau et d'un gaz non-condensable, dans le cas présent, le CO2. Deux tuyères d'éjecteur à vapeur, d'un diamètre de 4.60 mm et 4.23 mm, ont été évaluées sur une plage de niveaux de CO2 dans le fluide secondaire, jusqu'à environ 40% en masse. La pression primaire était maintenue à 450 kPa avec une surchauffe à 10 °C et la pression secondaire était de 70 kPa. On a constaté que la pression critique ne changeait pas à mesure que la fraction massique de CO2 dans le fluide secondaire augmentait. Cependant, le rapport d'entraînement a augmenté de façon linéaire sur la plage expérimentale. Une amélioration de 23% du rapport d'entraînement par rapport à la vapeur pure a été observée lorsque le fluide secondaire contient 42% de CO2 par masse. Ce comportement contraste nettement avec le comportement observé expérimentalement d'un éjecteur à vapeur pure, où une augmentation du rapport d'entraînement se produit au détriment d'une diminution de la pression critique. Trois articles détaillés ont été publiés sur divers scénarios d'intégration d'un éjecteur à vapeur dans un procédé de captage d'absorption/désorption. Le solvant de référence était de 20% en masse de monoéthanolamine (MEA). Trois configurations principales ont été étudiées, selon le choix du fluide utilisé pour produire la vapeur secondaire : éjecteur sur condensat, éjecteur sur pauvre ou éjecteur sur riche. La première publication de revue scientifique a porté sur le procédé de désorption et a présenté une méthode de raccourci basée sur les propriétés du mélange CO2-MEA-H2O à l'équilibre. Les simulations ont révélé des réductions dans la quantité requise d'énergie de haute qualité, de 10 à 25%. Un simulateur de procédé commercial, Aspen Plus, a été utilisé pour les deux autres publications. Dans la deuxième publication de revue scientifique, le module cinétique rate-based a été utilisé, au lieu du module d'équilibre, pour la modélisation de l'absorbeur et du désorbeur, permettant des évaluations énergétiques plus près des valeurs qu'on retrouve dans la littérature courante. Une étude a été réalisée pour comparer un scénario de préchauffage de la vapeur primaire par des rejets thermiques externes avec un scénario d'intégration de la chaleur interne. Cette deuxième publication a montré des économies d'énergie de haute qualité, de 10 à 14%, les scénarios avantageux ayant été «éjecteur sur condensat» et «éjecteur sur pauvre». / Abstract : The main goal of the doctoral project is to determine to what extent the optimal integration of single-phase ejectors might reduce the large amount of energy required to capture carbon dioxide from electric power generation facilities. More specifically, the objective is to determine if ejectors can be advantageously integrated into a post-combustion absorption/desorption carbon dioxide (CO2) capture process using monoethanolamine (MEA). The integrated ejectors will use waste heat of 100 °C from the electric power plant. The upgraded waste heat can partially replace valuable turbine steam that would otherwise be taken from the power plant. The second objective of the thesis is to experimentally evaluate the performance of a steam ejector where the ejector secondary fluid is a mixture of steam and a non-condensable gas, in this case CO2. Two steam ejector nozzles, of 4.60 mm and 4.23 mm diameter, were evaluated over a range of secondary fluid CO2 levels, up to 42% by mass. The primary pressure was maintained at 450 kPa with 10 °C superheat and the secondary pressure was 70 kPa. It was found that the critical exit pressure did not change as the mass fraction of CO2 in the secondary fluid increased. The entrainment ratio, however, increased approximately linearly over the experimental range. An improvement of 23% in the entrainment ratio, as compared with pure steam, was found when the secondary fluid contains 42% CO2 by mass. This behaviour is in sharp contrast to the experimentally observed behaviour of a pure steam ejector, where an increase in entrainment ratio comes at the expense of a decrease in the ejector exit critical pressure. Three published papers investigated various scenarios for the integration of a steam injector into an absorption/desorption post-combustion capture process. The reference solvent was 20% weight monoethanolamine (MEA). Three principal configurations were studied, according to the choice for the liquid flow used to produce the ejector secondary steam: ejector on condensate, ejector on lean or ejector on rich. The first journal publication focused on the desorption process and presented a shortcut method based on CO2-MEA-H2O equilibrium vapour liquid data. The simulations revealed reductions in the required amount of valuable energy from 10 to 25%. A commercial process simulator, Aspen Plus, was used for two other publications. In the second journal publication, the kinetic rate-based module was employed to model the absorber and desorber, providing energy evaluations closer to values in the open literature. A study was included comparing preheating the primary steam with waste heat or by heat integration. The rate-based simulation found valuable energy savings of 10 to 14%, with the "ejector on condensate" and "ejector on lean" again being the advantageous scenarios.

Physical education (PE) at school may play an important role in the process of becoming physically active in the adolescence and in developing a physically active lifestyle. The opportunities for teachers to provide positive physical activity experiences to the student population extend regularly over the school terms. For some students, PE can be the only opportunity they have to be physically active. Therefore it is important that the students become motivated to practice physical activity and know the purpose with physical activity. The overall purpose of this dissertation was to investigate the possibilities to motivate youth, 12-16 years old, to practice physical activity and hopefully to stimulate them to continue to be physically active in young adulthood. The sample consisted of 122 Swedish compulsory school students (12-16 years old), 51 girls and 71 boys, who were either physically inactive, physically active but not formal members of sport clubs, or physically active and members of a sport club. They used a self-monitoring instrument to describe their physical activity and we compared their self-reported physical activity with their actual VO2 capacity and physical status. The self-monitoring instrument was further validated against an activity monitor, RT3. The intervention lasted one and a half years, and four to five years later a follow-up study was done. Using a quasi-experimental design, the three groups of participants were compared with youths who did not use the selfmonitoring instrument. The main findings were that the associations between the accelerometer counts and the activities the students recorded in the self-monitoring instrument were high. The participants in Group 1 (physically inactive) continued exercising nearly to the same extent as during the intervention while youths in a matched control group did not develop regular physical activity habits. Concerning Group 2 (exercisers), participants in the intervention group were more physically active both during the intervention and at follow-up, compared with a matched control group of exercisers who did not use the self-monitoring instrument. In Group 3 (sport team members), there was no difference between the intervention group and a matched control group after the intervention or at follow-up. The conclusion of these main findings was that when someone motivates students to continue being physically active and to change their physical activity patterns in a positive direction, the self-monitoring instrument can be a door-opener for youths who are physically inactive or regularly active outside sports clubs.

With an increased urgency for global action towards climate change mitigation, this research was undertaken with the aim of evaluating post-combustion CO2 capture as an emission abatement strategy for gas-fired power plants. A dynamic rate-based model of a capture plant with MEA solvent was built, with imposed chemical equilibrium, and validated at pilot scale under transient conditions. The model predicted plant behaviour under multiple process inputs and disturbances. The validated model was next used to analyse the process and it was found that CO2 absorption is mass transfer limited. The model was then improved by explicitly adding reactions rate in the model continuity, the first such dynamic model to be reported for the capture process. The model is again validated and is observed to provide better predictions than the previous model. Next, high fidelity models of a gas-fired power plant, a scaled-up capture plant and a compression train were built and integrated for 90% CO2 capture. Steam for solvent regeneration is extracted from the power plant IP/LP crossover pipe. Net efficiency drops from 59% to 49%, with increased cooling water demand. A 40% exhaust gas recirculation resulted in a recovery of 1% efficiency, proving that enhanced mass transfer in the capture plant reduces solvent regeneration energy demands. Economic analysis reveals that overnight cost increases by 58% with CO2 capture, and cost of electricity by 30%. While this discourages deployment of capture technology, natural gas prices remain the largest driver for cost of electricity. Other integration approaches – using a dedicated boiler and steam extraction from the LP steam drum – were explored for operational flexibility, and their net efficiencies were found to be 40 and 45% respectively. Supplementary firing of exhaust gas may be a viable option for retrofit, as it is shown to minimise integrated plant output losses at a net efficiency of 43.5%. Areas identified for further study are solvent substitution, integrated plant part load operation, flexible control and use of rotating packed beds for CO2 capture.

Mobile enterprise applications (MEAs) are found in increasing numbers in organisations as smart-devices become an everyday necessity amongst employees and customers. Large amounts are invested in these applications, so it is important to see the value in improved business processes and the consequential improvement in business performance. Realising the benefits from their use is important to obtain the value from these investments. Yet, benefits management (BM) is poorly implemented in companies and a first step to improve this situation is to improve the visibility of the benefits that can be achieved by using MEAs. Hence the primary question asked in this study is “How can MEA benefits be successfully realised?” The strategy used to answer the question was action research in a single organisation using three MEAs in two different action research cycles. The study was conducted in a short-term insurance company in the Western Cape of South Africa with an established IT and project capability. Globally, the short-term insurance industry is under a significant threat from disruption by market entrants who don’t have to navigate legacy systems and who are more agile with their product offerings. Traditional insurers are looking for innovative solutions to transform the way in which insurance is sold and serviced. A BM process, which was modified from the literature, was refined through action cycles in three MEA projects to improve benefits realisation. The result showed that for MEA projects, which are not very large investments relative to other IT projects, a lighter, less cumbersome process was more practical and acceptable in the organisation. The creation of a benefits and risks template, during the action cycles, helped the organisation to build stronger business cases for MEA projects and also allowed for more comprehensive benefit identification, measurement and tracking, ultimately realising business performance improvements. The study also used a survey amongst 88 brokers and assessors to determine the factors which influence their adoption of these MEAs. The most significant factors influencing user adoption were the company’s willingness to fund the smart-devices, the ease of use of the MEA, job relevance and location dependence. A limitation of this study is that the organisation has a particular approach to project funding whereby the importance of BM is weighed against the cost of the project, hence BM is more important for very expensive projects. While the model prescribed in this study was sufficient in this context, it may not be suitable for organisations that are more conscientious about BM. This model would need to be tested in other contexts for transferability. A further limitation was the duration of time available for conducting this study because this was a PhD research project. Further action cycles might have refined the process further. The findings from this study are relevant to researchers and to organisations wanting to deploy MEAs. The BM process defined in this study can be used in MEA projects as a process to manage the identified benefits and ensure that they are realised. The benefits template can be used as a first step in the BM process to build the business case and the risks template can be used to identify potential problems that could hinder benefits realisation and can used to put mitigating actions in place to prevent problems to benefits realisation. The identification of factors influencing adoption of MEA can help organisations focus on these factors to ensure that their MEAs are used and they thereby derive benefits. The theoretical contributions of this study are a process model for the BM body of knowledge and a model explaining the factors influencing symbolic adoption of MEA. The identification and description of benefits and risks extends the body of knowledge for mobile applications research. These specific issues in the context of MEAs in the short-term insurance industry are understudied.

[pt] A presente dissertação analisa os sentidos atribuídos ao cuidado por profissionais do Centro de Referência Especializado de Assistência Social (CREAS) Maria Lina de Castro Lima, inseridos em dinâmicas familiares de cuidados de longa duração de idosos. Trata-se de uma pesquisa com abordagem qualitativa, cujo principal instrumento para a produção de dados consistiu em entrevistas narrativas, realizadas no mês de dezembro de 2019, com cinco profissionais na qualidade de filhos e/ou sobrinhos de uma pessoa idosa que necessita de apoio afetivo, material ou financeiro. A análise dos dados obtidos se deu através do método de interpretação de sentidos, sendo possível identificar percepções dos sujeitos da pesquisa acerca dos desafios, possibilidades, desigualdades, acordos e concessões ao desempenharem essa tarefa. Dentre os resultados alcançados, se constatou que se por um lado o sentimento de reciprocidade se destacou como uma das motivações para desempenharem essa função, em contrapartida apreendeu-se a obrigação também como uma das razões expressas. Além disso, percebeu-se a relevância para os entrevistados em preservar a autonomia desse familiar. Resultados que foram analisados a partir das fundamentações teóricas que basearam esse estudo, considerando as principais categorias de análise - família, gênero e cuidado - que nortearam a pesquisa. / [en] This dissertation analyzes the meanings attributed to care by professionals from the Specialized Reference Center for Social Assistance (CREAS) Maria Lina de Castro Lima, inserted in family dynamics of long-term care for the elderly. This is a research with a qualitative approach, whose main instrument for data production consisted of narrative interviews, held in December 2019, with five professionals as children and / or nephews of an elderly person who needs support affective, material or financial. The analysis of the data obtained was done through the method of interpretation of meanings, making it possible to identify the research subjects perceptions about the challenges, possibilities, inequalities, agreements and concessions when performing this task. Among the results achieved, it was found that, if on one hand the feeling of reciprocity stood out as one of the motivations for performing this function, on the other hand, obligation was also comprehended as one of the reasons expressed. In addition, it was noticed the relevance for the interviewees in preserving the autonomy of this family member. The results were analyzed from the theoretical foundations that based this study, considering the main categories of analysis - family, gender and care - that guided the research.

MEASURING IMPEDANCE OF TISSUES USING A MICROFABRICATED MICROELECTRODE ARRAY By Ashwini Bhat This thesis looks at the possibility of using impedance spectroscopy for differentiating tissue, using a microelectrode array (MEA). The thesis first discusses the background and the motivation for this thesis. It covers the certain basic concepts of the human skin starting from the top epidermis layer all the way to the deep dermis layers of the skin. Then it discusses different types of skin cancer and how they occur, in humans. It also discusses various microfabrication techniques such as oxidation, wet etching, sputtering and photolithography for the creation of a MEA in order to test the tissue. The microfabricated MEA is then used to measure impedance across cooked and raw chicken at different frequencies in order to see if the two types of tissues can be differentiated using their respective impedances. The data shows that the MEA was not able to successfully differentiate the two types of the tissues. It does however list multiple improvements in the fabrication of the MEA and improvements that could be made to the testing procedures which could possible give greater difference in impedance between the two tissues

Steigende Zahlen von Patienten mit neurodegenerativen Erkrankungen sind ein überzeugender Grund, das menschliche Gehirn und seinen fortschreitenden Verfall zu untersuchen, wobei aber viele essenzielle biochemische Funktionen bisher noch nicht vollends geklärt sind. In vitro Forschung zur Hirnfunktion auf geeigneten Plattformen ist ein vielversprechender Weg, diese Lücke zu schließen. Eigenschaften der brain-machine Grenzfläche müssen erforscht werden, um neue Biomaterialien effektiv für lab-on-a-chip Anwendungen wie bspw. Multielektrodenarrays (MEAs) einzusetzen. Diese brain-on-a-chip Anwendungen können dazu dienen, die Zahl der Tierexperimente zu reduzieren, damit Forschung zu beschleunigen und Kosten zu senken. In dieser Hinsicht erfordert die Miniaturisierung von MEAs für eine detailliertere Messung von neuronalen Funktionen die Entwicklung von neuen Biomaterialien mit vorteilhaften elektrischen Eigenschaften. Die Wechselwirkung dieser Biomaterialien mit Zellen muss untersucht werden, um gute Zelladhäsion, Proliferation und elektrische Kopplung zu gewährleisten. Die vorliegende Arbeit dient der Charakterisierung der Wechselwirkung von humanen neuronalen Zellen und Gliazellen (neuronenartige SH-SY5Y und gliaartige U-87 MG Zellen) mit dem Elektrodenmaterial Titannitrid mit nanokolumnarer Oberfläche (TiN nano) und dessen Vorteile bezüglich elektrischer und bioaktiver Eigenschaften im Vergleich mit Gold (Au) und Indiumzinnoxid (ITO), welche derzeit für MEAs und Neuroelektroden verwendet werden. Das Ziel der Arbeit ist die Implementierung neuer aus der theoretischen Physik, Mathematik und Computerwissenschaft entlehnten Techniken, um eine bildbasierte Methode zu entwickeln, die auf minimalen Experimenten beruht und trotzdem wichtige Hinweise zur Biokompatibiliät eines Materials liefert. Das schließt die Analyse von Zellnetzwerken, Zellverteilung, Adhäsion und elektrochemischer Eigenschaften in mono- und co-Kultur ein. Dazu werden Autokorrelation, selbstlernende Algorithmen und die Analyse nächstgelegener Nachbarn eingesetzt, um einen Weg von klassischen biochemischen Assays weg zu einem rechnerischen Ansatz zu finden. Die Ergebnisse zeigen eine Überlegenheit von Tin nano als potenzielles Biomaterial für lab-on-a-chip Anwendungen und in vivo neuraler Stimulation. Die präsentierte bildbasierte Analysemethode für die Untersuchung von Zellverteilungen erweist sich als wertvolles Werkzeug für die Bewertung von Biokompatibilität. Sie ist universell einsetzbar für verschiedene Zelltypen und quantifiziert die Wechselwirkung von Zellen mit Biomaterialien. / Rising numbers of patients with neurodegenerative diseases are a compelling reason to study the human brain and its progressive deterioration but many essential biochemical functions are still under investigation. Conducting research on brain function in vitro with suitable platforms is a promising solution to close these gaps. Characteristics of the brain-machine interface need to be investigated to effectively employ new biomaterials for lab-on-a-chip devices, such as multielectrode arrays (MEAs) for example. These brain-on-a-chip devices will potentially reduce the number of conducted animal experiments and therewith accelerate future research and reduce costs. In this context, miniaturization of MEAs for more detailed measurements of neuronal function calls for new biomaterials with advantageous electrical characteristics. The interaction of these biomaterials with cells needs to be investigated to ensure good cell adhesion, proliferation, and electrical coupling. This thesis aims to study and characterize the interaction of human neuronal and glial cells (neuron-like SH-SY5Y and glia-like U-87 MG cells) with the electrode material titanium nitride with nanocolumnar surface topography (TiN nano) and its advantages in terms of electric and bioactive properties compared to gold (Au) and indium tin oxide (ITO) which are currently employed for MEAs and neuroelectrodes. The overall goal of this study is the implementation of new techniques drawn from theoretical physics, mathematics, and computer science to establish an image-based method that relies on minimal experimental effort but nevertheless yields important evidence of biocompatibility of the material. Analysis includes the investigation of cellular networks, cell distribution, adhesion, and electrochemical properties in mono- and co-culture experiments. To this end, autocorrelation function, self-learning algorithms, and nearest neighbor analysis are deployed to move away from classical biochemical assays toward a more computational approach. Results show the superiority of TiN nano as a potential biomaterial employed for lab-on-a-chip designs as well as for in vivo neural stimulation. The proposed image-based analysis method for the investigation of cellular distribution turns out to be a valuable tool for the assessment of biocompatibility. It is universally applicable to cell types other than neuronal and quantifies the interaction of cells with biomaterials.

The tendency of recent years towards electrification of aircraft components and subsys-tems has opened the door for a wider usability of electro-mechanical actuators (EMAs) inthat context. EMAs are already in use in aircraft industries but mainly in civil aviation forsecondary control systems and non-critical applications. Therefore it is evident that thereexists a need for further research in the sector of utilization of EMAs for other areas withinthe aircraft manufacturing industry before they can be effectively applied. In this thesisan analysis of the power and thermal behaviour of EMAs has been done to evaluate theirapplicability in primary control systems for fighter aircrafts as compared to conventionallyused hydraulic systems. Furthermore, a method for scaling of such actuators in an initialdesign stage where few parameters are known has been developed and validated. One ofthe most substantial drawbacks against choosing EMAs for these purposes is the disadvan-tageous thermal transfer capability of electrical machines in high power applications. Aninvestigation has therefore also been made on calculation of power losses of electrical mo-tors and inverters. The results have been compared against a servo hydraulic actuator. Ascalable simulation model derived from motor data statistics has been developed in orderto simulate power losses and the thermal behaviour of these actuators. The model takesvery few parameters as input as an aircraft designer working in the preliminary stages ofthe design process often have limited knowledge of the final product, but at the same timeneed a fairly accurate view of how the actuators ought to be scaled with regard to weight,power and thermal transfer. The model shows promising results when verified against anactual electro-mechanical actuator on Iron Bird test rig. Finally, this work aims to furtherthe development of an Iron Bird situated on Linköping University, through an integrationbetween three thesis projects where the final product shall be an Hardware In The Loop(HWIL) simulation with several actuators involved.

[pt] Tendo em vista a reduzida produção acadêmica acerca do cuidado sob uma perspectiva epistemológica, a análise histórica da constituição da família brasileira e dos processos através dos quais o cuidado passa a fazer parte deste contexto revela-se fundamental para avançarmos na discussão acerca do cuidado familial. Neste contexto, realizamos uma pesquisa bibliográfica com o objetivo de identificar elementos que contribuam para a conceituação do cuidado em família a partir da produção brasileira contemporânea, analisando-os a partir do método de interpretação de sentidos, tal como proposto por Gomes. Os resultados permitiram observar elementos que repetidamente aparecem nos estudos realizados, articulando o papel protetor da família, suas formas de cuidar e as diferentes maneiras de definir a categoria cuidado e denotando a complexidade da questão e a necessidade de se produzir novas formas de olhar para o cuidado em família. / [en] Considering the limited academic production of care from an epistemological perspective, the historical analysis of the Brazilian family s constitution and the processes through which care becomes part of this context is crucial to launch the discussion about family care. In this context, we carried out a bibliographical research with the objective of identifying elements that contribute to the conception of family care from Brazilian contemporary production, analysing them from the method of interpretation of meanings, as proposed by Gomes. The results allowed us to observe elements that repeatedly appear in the studies carried out, articulating the protective role of the family, their ways of caring and the different ways of defining the care category and denoting the complexity of the issue and the need to produce new ways of looking at the Family care.