Dissertations / Theses on the topic 'Pure strategies'

This thesis is concerned with the development of new numerical techniques for solving initial value problems in ordinary differential equations (ODE). The thesis begins with an introductory chapter on initial value type problems in ordinary differential equations followed by a chapter on basic mathematical concepts, which introduces and discusses, among others, the theory of Arithmetic and Geometric Means. This is followed, in Chapter 3, by a survey of the existing ODE solvers and their theoretical background. The advantages and disadvantages of some different strategies in terms of stability and truncation error are also considered. The presentation of the elementary methods based on Arithmetic Mean (AM) and Geometric Mean (GM) formulae is done in Chapter 4, with emphasis on establishing the GM trapezoida1 formula, and to the study of its stability and truncation error. Applications in the predictorcorrector and the extrapolation techniques are also considered. Special application in the solution of delay differential equations is also presented. In Chapter 5, the application of the GM strategy in the Runge-Kutta type formulae is considered, producing a new class of methods called the GM-Runge-Kutta formulae which is found to be as competitive as the classical Runge-Kutta methods. Thereafter, a new strategy of error control called the Arithmeto-Geometric Mean (AGM) strategy is developed. Further application of the GM-Runge-Kutta in Fehlberg type formulae, and the GM-Iterative Multistep formulae are also considered. Chapter 6 concerns with further applications of GM techniques in the development of generalised GM mu1tistep and multiderivative methods, and for solving y'=λ(x)y. The general idea of the GM are also extended to other types of Means, such as Harmonic and Logarithmic Means. In Chapter 7, some new formulae for solving problems with oscillatory and periodic solutions are considered. Finally the thesis concludes with recommendations for further work.

We study game theoretic ecological models with cyclic competition in the case where the strategies can be mixed or pure. For both projects, reported in [49] and [50], we employ Monte Carlo simulations to study finite systems. In chapter 3 the results of a previously published paper [49] are presented and expanded upon, where we study the extinction time of four cyclically competing species on different lattice structures using Lotka-Volterra dynamics. We find that the extinction time of a well mixed system goes linearly with respect to the system size and that the probability distribution approximately takes the shape of a shifted exponential. However, this is not true for when spatial structure is added to the model. In that case we find that instead the probability distribution takes on a non-trivial shape with two characteristic slopes and that the mean goes as a power law with an exponent greater than one. This is attributed to neutral species pairs, species who do not interact, forming domains and coarsening. In chapter 4 the results of [50] are reported and expanded, where we allow agents to choose cyclically competing strategies out of a distribution. We first study the case of three strategies and find through both simulation and mean field equations that the probability distributions of the agents synchronize and oscillate with time in the limit where the agents probability distributions can be approximated as continuous. However, when we simulate the system on a one-dimensional lattice and the probability distributions are small and discretized, it is found that there is a drastic transition in stability, where the average extinction time of a strategy goes from being a power law with respect to system size to an exponential. This transition can also be observed in space time images with the emergence of tile patterns. We also look into the case of four cyclically competing strategies and find results similar to that of [49], such as the coarsening of neutral domains. However, the transition from power law to exponential for the average extinction time seen for three strategies is not observed, but we do find a transition from one power law to another with a different slope. This work was supported by the United States National Science Foundation through grants DMR-0904999 and DMR-1205309.
Ph. D.

Mathematical modeling can help providing better understanding of the nature and characteristics of regulatory processes in hematology. We first review different mathematical approaches used for modeling so-called dynamical hematological diseases, which are characterized by oscillations in one or more blood cell lines. Then, we present two delay differential equation (DDE) models of the hematopoietic system designed for the study of the effects of Granulocyte-Colony Stimulating Factor (G-CSF) administration. G-CSF is used clinically for treating subjects presenting low numbers of white blood cells, a condition referred to as neutropenia that can result from different causes. However, even though G-CSF is widely used in clinical practice, it is not clear whether the standard G-CSF administration schedule is optimal. The aim of this work is to study alternative treatment regimens that would optimize the use of G-CSF using a mathematical modeling approach. The first model we propose is a comprehensive model that considers G-CSF administration for cyclical neutropenia, a dynamical disorder characterized by oscillations in the circulating neutrophil count. The second model focuses on the effects of two recombinant forms of G-CSF (filgrastim and pegfilgrastim) for the treatment of chemotherapy-induced neutropenia. For each model, we use a combination of mathematical analysis and numerical simulations to study alternative G-CSF treatment regimens that would be efficient while reducing the amount of drug. We found that the dynamical properties of the model could be exploited for designing better G-CSF treatment strategies.
La modélisation mathématique est un outil qui permet d'obtenir une meilleure compréhension des différents processus de régulation en hématologie. Dans un premier temps, nous révisons différentes approches qui sont utilisées pour modéliser les maladies hématologiques dites dynamiques. Celles-ci sont caractérisées par la présence d'oscillations dans le niveau d'un ou de plusieurs types de cellules sanguines. Ensuite, nous présentons deux nouveaux modèles d'équations différentielles à délais (EED) du système hématopoïétique, qui sont dédiés à l'étude des effets de l'administration du granulocyte-colony stimulating factor (G-CSF). Le G-CSF est utilisé en pratique pour traiter les patients dont le niveau de globules blancs est faible, une condition appelée neutropénie, qui peut survenir dans plusieurs contextes. Cependant, même si le G-CSF est largement utilisé dans le milieu médical, il n'est pas clair que le protocole d'administration standard soit optimal. L'objectif de cette thèse est d'étudier des protocoles de traitement alternatifs qui optimiseraient l'utilisation du G-CSF en utilisant une approche de modélisation mathématique. Le premier modèle que nous proposons est un modèle qui inclut tous les types de cellules sanguines et qui considère l'administration du G-CSF dans le cas de la neutropénie cyclique, une maladie caractérisée par la présence d'oscillations dans le nombre de globules blancs, de plaquettes et de globules rouges. Dans le second modèle, nous nous intéressons aux effets de deux formes de G-CSF (filgrastim et pegfilgrastim) qui sont utilisés pour traiter la neutropénie qui survient fréquemment suite à la chimiothérapie. Pour chacun des modèles, nous utilisons une combinaison d'analyse mathématique et de simulations numériques pour étudier des traitements alternatifs de G-CSF qui seraient efficaces tout en réduisant la quantité de médicament utilisée. Nos résultats suggèrent que les pr

The fact that we have entered turbulent times has been a central theme in the recent strategy literature. Turbulent environments are commonly described by increased competitive intensity, disruptive changes in the industry structure, volatility of demand, and unpredictability of customer behaviour, alongside instability of economic, social and political factors. In such a context, the adoption of traditional approaches to strategy, which assumes a relatively stable world, have been questioned by new approaches. Mixed strategy, which emerged as a contingency option to Porter's generic strategies model, defends that in a turbulent environment the simultaneous pursuit of the low-cost and differentiation approaches is fundamental for the short-term performance and long-term survival of the firm. A vast corpus of literature supports the benefits of adopting a mixed approach strategy: several empirical studies have proved that a combination of low-cost and differentiation strategic elements establishes a firm's performance superiority over the pure strategy choice. The mixed literature has concentrated on the performance linkage and on the debate countering the pure strategy approach, however very little attention has been paid to the challenges presented by the mixed strategy implementation. In fact, despite the rich empirical literature, it is still not clear how firms that adopt a mixed strategy may successfully integrate the inherent contradiction of the low-cost and differentiation approaches. The aim of this study is to investigate how a firm has been implementing the mixed strategy approach, unveiling its managerial characteristics and to generate a proposed managerial framework that could serve as a guide for further implementation. This study approaches the subject of mixed strategy implementation on three levels: environment, strategy definition and making process, and value chain activity. After having elucidated several ambiguities related to the concept of mixed strategy present in the literature and having proposed a normalized definition, this study investigates through a unique case study approach, an in-depth explorative process using causal process methods the managerial implication of the mixed strategy. Several characteristics are revealed from the unique case study and represent a major contribution to the field of strategy management. Furthermore, a managerial framework is proposed which could serve as support in the implementation of a mixed strategy.

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This work focuses on presenting the basic elements of the Economic Theory of Games in a way that is suitable for exposition at the mathematical level of high school education in Brazil. With that in mind, the work covers a brief historical context of the subject, classic games of Economic Theory of Games, what are pure and mixed strategies, methods of systematization, the concept of solution, methods to find solutions and, at the end, we suggest a Mathematical Workshop on Economic Theory of Games as a way to introduce the subject to high school students.
Este trabalho concentra-se em apresentar os elementos básicos da Teoria Econômica dos Jogos limitando seu conteúdo ao nível matemático do ensino médio da educação brasileira. Para tanto é nele exposto: uma breve contextualização histórica do assunto, jogos clássicos da Teoria Econômica dos Jogos, o que são estratégias puras e mistas, métodos de sistematização, o conceito de solução, métodos para encontrar soluções e, ao final, uma proposta de oficina matemática sobre Teoria Econômica dos Jogos a ser ministrada a estudantes do ensino médio.

Les pêcheries de thonidés représentent 7.9% de la production mondiale de produits de la mer. La plupart des stocks de thons sont pleinement exploités, et certains surexploités, et tous font face à une pression de pêche croissante. En raison de l'extension des zones de pêche, les évaluations des stocks dépendent en grande partie des captures commerciales. Toutefois, les données commerciales peuvent varier au cours du temps étant donné que les pêcheurs peuvent investir dans des engins de pêche et de l'équipement, s'établir au large des côtes, ou commencer à pêcher dans de nouvelles zones. Peu d'attention a été portée à la réponse des pêcheurs aux mesures de gestion ou aux conséquences de l'investissement technologique. L'objectif de la présente thèse est d'étudier les effets de stratégies de pêche et les réponses adaptatives des flottes de senneurs sur les thons tropicaux et la faune associée dans l'Océan Atlantic Est et dans l'Océan Pacifique Est. Dans un premier temps, nous montrons comment l'introduction de nouvelles technologies a eu un effet direct en augmentant la puissance de pêche, et un effet indirect en entraînant une modification des zones pêche. Nous étudions les effets de deux fermetures spatio-temporelles sur la dynamique de la flotte de senneurs européens. La première mesure de gestion a diminué les jours où des captures sont réalisées, les carrés avec capture à l'intérieur de la zone partiellement fermée, tandis que la pêche sur DCP a été redistribuée à l'extérieur de la zone et aucun changement n'a pas été enregistré pour la pêche sur banc libre. La seconde fermeture de pêche a entraîné une augmentation de toutes les activités de pêche en dehors de la zone. Dans l'Océan Pacifique Est, la flotte de senneurs mexicains a réagit à la fermeture d'une saison de pêche en diminuant le nombre de jours passés à quai. Par conséquent, le nombre de calées sur bancs associés aux dauphins a augmenté, et les niveaux de capture observés avant la mesure de gestion ont été maintenues. Nous analysons les effets des stratégies de senneurs de l'Union Européenne sur les prises accessoires. Nous mettons en évidence que la composition des espèces de requins capturés sous DCP et les raies capturées sur bancs libres ont changé au cours du temps. Nous estimons également que plusieurs types d'espèces peuvent être capturés par mode de pêche
Tuna and tuna-like fisheries represent 7.9% of the global production of marine capture fisheries. Most tuna stocks are fully exploited and some overexploited, facing growing fishing pressures. Due to the extent of fishing grounds, stock assessments depend largely in commercial data, which vary over time because fishermen may invest in fishing technology, expand offshore, or start fishing in different areas. However, little attention has received the responses of fishermen facing management regulations or the effects resulting from technological investment. For these reasons the aim of this study was to investigate the effects of fishing strategies developed by purse seine fleets on tropical tunas and on associated fauna in the eastern Atlantic and eastern Pacific oceans. The continuous introduction of new fishing technology in the French fleet in the 1980s and the 1990s evidenced a direct increase in fishing power when large yellowfin in free-swimming school is targeted and likely an indirect effect by modifying the fishing grounds characterizing FAD-fishing on small size categories. The consequences of the two time-area closures on the spatio-temporal dynamics of the European Union fleet were investigated. The regulation on FADs resulted in a decrease in the days with catch and successful squares inside the restricted area, reallocating FAD-fishing outside the area while no change in free-swimming school fishing was observed. The no-take time-area increased all fishing activities outside the restricted area with apparently no gain in terms of protection of juveniles. In the eastern Pacific as a response to a closed season the Mexican fleet reduced days in port and consequently the number of sets on dolphin-associated schools increased, maintaining the catch levels observed before the regulation. The study of the effects of the EU fleet fishing strategies on bycatch over two time periods showed that the species composition of sharks caught on FADs and may be for rays caught on free-swimming schools changed over time. We also estimated the total number of species that can be potentially be caught by fishing mode

La producció d’hidrogen, a gran escala, a partir d’aigua ha esdevingut un repte des de fa uns quants any enrere. Així, una via ecològica i eficient per a la generació d’hidrogen ha de ser establerta. Entre totes les possibilitats, la electròlisis mitjançant la tecnologia de membranes bescanviadores de protons (PEM) és la tècnica més prometedora per a aconseguir tal propòsit. A més a més, aquesta aproximació també pot ser considerada per a dur a terme reaccions electroquímiques per altres propòsits més enllà de la generació d’hidrogen, com per exemple, la reducció de contaminants d’origen químic. A la llum d’aquests antecedents, reactors electro-catalítics multi-funció basats en membranes de bescanvi protòniques, integrats en un sistema en flux, per a (1) producció d’hidrogen i (2) reducció de nitrats (contaminant estudiat) a nitrogen, van ser dissenyats, construïts i finalment avaluats, satisfactòriament. Catalitzadors heterogenis basats en metalls van ser utilitzats com a materials d’elèctrode per a realitzar les reaccions electroquímiques desitjades. El MoS2, així com, el Co3O4 van ser descoberts com a materials prometedors per a la producció d’hidrogen en sistemes d’electròlisis PEM degut al seu rendiment, preu i abundància en l’escorça terrestre. Utilitzant la mateixa estratègia, catalitzadors suportats en SnO2 van ser emprats per a la reducció en continu de nitrats, en fase aquosa, sota condicions electroquímiques. Aquesta aproximació va ser anomenada reducció de nitrats assistida mitjançant electròlisis. El catalitzador de SnO2 modificat amb PdCu va destacar com el material d’elèctrode amb millor rendiment en termes de conversió i selectivitat. Mitjançant la modificació dels paràmetres de treball, així com, la configuració del reactor, la versatilitat i flexibilitat d’aquesta estratègia van ser avaluades per a poder afinar la formació de productes durant la reacció.
La producción de hidrógeno, a gran escala, a partir de agua se ha convertido en un reto desde ya hace unos cuantos años. Así, una vía ecológica y eficiente para la generación de hidrógeno tiene que establecerse. Entre todas las posibilidades, electrólisis mediante la tecnología de membranas de intercambio de protones (PEM) es la técnica más prometedora para conseguir dicho propósito. Además, dicha aproximación también puede ser considerada para llevar a cabo otras reacciones electroquímicas con propósitos totalmente distintos a la producción de hidrógeno, como por ejemplo, la reducción de contaminantes de origen químico. A la luz de estos antecedentes, reactores electroquímicos multifuncionales basados en membranas de intercambio protónicas, integrados en un sistema en flujo, para (1) producción de hidrógeno y (2) reducción de nitratos (contaminante estudiado) a nitrógeno, fueron diseñados, construidos y evaluados, satisfactoriamente. Catalizadores heterogéneos basados en metales fueron utilizados como materiales de electrodo para realizar las reacciones electroquímicas deseadas. MoS2, así como, Co3O4 fueron descubiertos como materiales prometedores para la producción de hidrógeno en sistemas de electrólisis PEM, debido a su rendimiento, precio y abundancia en la corteza terrestre. Empleando la misma estrategia, catalizadores soportados en SnO2 fueron utilizados para la reducción en continuo de nitratos, en fase acuosa, bajo condiciones electroquímicas. Esta aproximación fue llamada reducción de nitratos asistida mediante electrolisis. Catalizador de SnO2 modificado con PdCu destacó como el material de electrodo con mejor rendimiento en términos de conversión y selectividad. Mediante la modificación de los parámetros de trabajo, así como, la configuración del reactor, la versatilidad y flexibilidad de esta estrategia fueron evaluadas para poder ajustar la formación de productos durante la reacción.
Large-scale hydrogen production from water has become a challenge since several years ago. Thus, a clean and efficient way for hydrogen generation has to be stablished; among all possibilities, electrolysis by means of proton exchange membrane (PEM) technology is the most promising technique to achieve such goal. Furthermore, this approach can be also considered as potential strategy to perform electrochemical reactions for other purposes rather than only hydrogen production, like chemical pollutants reduction. In the light of this backgrounds, a multipurpose proton exchange membrane (PEM) electrocatalytic reactors, integrated in a flow system, for (1) hydrogen production and (2) nitrate reduction (target pollutant) towards nitrogen, were successfully designed, constructed and lately evaluated. Metal-based heterogeneous catalysts were employed as electrode material to carry out desired electrochemical reactions. MoS2 as well as Co3O4 were found as promising materials for hydrogen production in PEM electrolysis system due to its performance, price and abundance on Earth’s crust. Using same strategy, SnO2 supported catalysts were employed for continuous aqueous phase nitrate reduction under electrochemical conditions. This approach was called electrolysis-assisted nitrate reduction. PdCu dopped SnO2 catalyst stood up as the best performing electrode material in terms of conversion and selectivity. By modifying working parameters as well as reactor configuration, versatility and flexibility of this strategy were evaluated in order to fine tune products formation during reaction.

This thesis develops models for accurate prediction of price changes on electronic stock exchanges by utilizing autoregressive and logistic methods. Prices on these electronic stock exchanges, also called ECNs, are solely determined by where orders have been placed into the order book, unlike traditional stock exchanges where prices are determined by an expert market maker. Identifying the significant variables and formulating the models will provide critical insight into the dynamics of prices on ECNs. Whereas previous research has relied on simulated data to test market strategies, this analysis will utilize actual ECN data. The models recognize patterns of asymmetry and movement of the shares in the order book to formulate accurate probabilities for possible future price changes. On traditional stock exchanges, price changes could only occur as quickly as human beings could enact them. On ECNs, computerized systems place orders on behalf of traders based on their preferences, resulting in price changes that reflect trader activity almost instantaneously. The quickness of this automation on ECNs forces the re-evaluation of commonly held beliefs about stock price dynamics. Previous strategies developed for trading on ECNs have relied mainly on price fluctuations to gain profits. This thesis uses the formulated models to design profitable strategies that use accurate prediction rather than price variability.

Dissertação de mestrado em Bioengenharia
Biogas is an alternative to substitute fossil fuels and is mostly composed by methane, a gas component that is produced by microorganisms called methanogens that use compounds such as acetate, hydrogen and carbon dioxide as substrates. In syntrophic communities, methanogens and bacteria exchange electrons for energetic purposes, normally through the use of soluble small chemical compounds that act as shuttles, such as hydrogen or formate. However, it has been recently suggested that in some cases this electron exchange can be performed directly or with the aid of conductive materials, which can potentially be a more energy conserving approach, thus improving the efficiency of methanogenesis. This project addressed the study of the effect of carbon nanotubes (CNT) in methane production by methanogenic communities, in two distinct studies. In the first study, assays were performed in batch with pure cultures of hydrogenotrophic, Methanobacterium formicicum and Methanospirillum hungatei, and acetoclastic methanogens, Methanosaeta concilii and Methanosarcina mazei, in the presence of CNT. Also, growth of pure cultures of M. formicicum was tested in the absence of a reducing agent. The results showed that CNT presence in pure cultures of the hydrogenotrophic methanogens resulted in an increased methane production and reduced lag phases. Although CNT also accelerated methane production by the acetoclastic pure cultures at 1 g/L CNT, a higher concentration of 5 g/L CNT, inhibited the methane production and induced longer lag phases. In the second study, co-cultures of butyrate-degrading bacteria Syntrophomonas wolfei and M. hungatei were grown with and without CNT, in order to determine the effect of CNT in butyrate-oxidizing syntrophic communities. The presence of CNT accelerated methane production by this co-culture, with methane production rate reaching a value of 1.03±0.03 mM/d for co-cultures incubated with 5 g/L CNT, while co-cultures in the absence of CNT only registered a rate of 0.72±0.01 mM/d. Adaptation of sludge in anaerobic bioreactors was also performed with the long-term objective of adding CNT, in order to assess its effect in complex microbial communities. By analysing the results obtained in this work, it was concluded that CNT improved hydrogen and acetate conversion to methane by pure cultures of methanogens and by syntrophic co-cultures of S. wolfei and M. hungatei. However, future studies with CNT are encouraged in order to understand the mechanisms by which CNT influences the methanogenic activity and in which cases it can be involved in interspecies electron transfer, since with the results obtained it remains unclear if they have a role in electron exchange between different species.
O biogás, que é composto maioritariamente por metano, é um componente gasoso produzido por microorganismos que usam como substrato moléculas simples, como o acetato, o hidrogénio ou o dióxido carbono, é uma conhecida alternativa aos combustíveis fósseis como fonte de energia. Em comunidades sintróficas, os organismos metanogénicos e as bactérias presentes trocam eletrões entre si com o objetivo de obtenção de energia para o seu crescimento, através de pequenos compostos químicos solúveis que servem de transporte, como o hidrogénio e o formato. Estudos recentes indicam que em alguns casos, estas trocas de eletrões podem ser realizadas diretamente ou por meio de materiais condutores, sendo esta uma abordagem que poderá ser mais favorável de um ponto de visto energético, aumentando assim a eficiência da metanogénese. Este projeto visou o estudo do efeito de nanotubos de carvão (NTC) nos mecanismos que envolvem a produção de metano em comunidades metanogénicas, através de dois diferentes estudos. No primeiro estudo, foram realizados ensaios em batch com culturas puras dos organismos metanogénicos hidrogenotróficos, Methanobacterium formicicum e Methanospirillum hungatei, e acetoclásticos, Methanosaeta concilii e Methanosarcina mazei, na presença de NTC. Além disso, também foram testadas culturas puras de M. formicicum na presença de NTC, mas sem adição de um agente redutor. Pelos resultados obtidos, verificou-se que os NTC provocaram um aumento na produção de metano e redução da fase de latência nas culturas puras dos metanogénicos hidrogenotróficos. Apesar de a presença dos NTC também ter acelerado a produção de metano nas culturas dos acetoclásticos com 1 g/L de NTC, numa maior concentração de 5 g/L de NTC, foi registada uma inibição na produção de metano e um aumento na duração das fases de latência. Num segundo estudo foram inoculadas culturas mistas contendo Syntrophomonas wolfei, uma bactéria que metaboliza butirato, e M. hungatei. Os resultados obtidos mostraram que a produção de metano também foi acelerada nas culturas mistas inoculadas com NTC, atingindo uma taxa de produção de metano de 1.03 ± 0.03 mM/d para as culturas incubadas com 5 g/L NTC, enquanto que na ausência de NTC, a taxa obtida foi de apenas 0.72 ± 0.01 mM/d. No âmbito deste trabalho, também foi realizada uma adaptação de biomassa em reatores anaeróbios, com o objetivo a longo prazo de adicionar os NTC para estudar o seu efeito em comunidades microbianas complexas. Por último, a análise dos resultados obtidos neste trabalho permitiu concluir que os NTC têm um efeito benéfico na conversão dos substratos a metano pelos microorganismos metanogénicos e pelas co-culturas sintróficas de S. wolfei e M. hungatei. Contudo, serão necessários mais estudos com os NTC para compreender melhor de que forma estes poderão estar envolvidos nos mecanismos de transferência de eletrões entre espécies, pois a sua influência neste processo continua por determinar.

Atomization of fuel is an important pre-requisite for efficient combustion in devices such as gas turbines, liquid propellant rocket engines, internal combustion engines and incinerators. The overall objective of the present work is to explore air-assisted atomization strategies for high viscosity fuels and liquids. Air-assisted atomization is a twin-fluid atomization method in which energy of the gas is used to assist the atomization of liquids. Broadly, three categories of air-assisted injection, i.e., effervescent, impinging jet and pre-filming air-blast are studied. Laser-based diagnostics are used to characterize the spray structure in terms of cone angle, penetration and drop size distribution. A backlit direct imaging method is used to study the macroscopic spray characteristics such as spray structure and spray cone angle while the microscopic characteristics are measured using the Particle/droplet imaging analysis (PDIA) technique. Effervescent atomization is a technique in which a small amount of gas is injected into the liquid at high pressure in the form of bubbles. Upon injection, the two-phase mixture expands rapidly and shatters the liquid into droplets and ligaments. Effervescent spray characteristics of viscous fuels such as Jatropha and Pongamia pure plant oils and diesel are studied. Measurements are made at various gas-to-liquid ratios (GLRs) and injection pressures. A Sauter Mean Diameter (SMD) of the order of 20 µm is achieved at an injection pressure of 10 bar and GLR of 0.2 with viscous fuels. An image-based method is proposed and applied to evaluate the unsteadiness in the spray. A map indicating steady/unsteady regime of operation has been generated. An optically accessible injector tip is developed which has enabled visualization of the two-phase flow structure inside the exit orifice of the atomizer. An important contribution of the present work is the correlation of the two-phase flow regime in the orifice with the external spray structure. For viscous fuels, the spray is observed to be steady only in the annular two-phase flow regime. Unexpanded gas bubbles observed in the liquid core even at an injection pressure of 10 bar indicate that the bubbly flow regime may not be beneficial for high viscosity oils. A novel method of external mixing twin-fluid atomization is developed. In this method, two identical liquid jets impinging at an angle are atomized using a gas jet. The effect of liquid viscosity (1 cP to 39 cP) and surface tension (22 mN/m to 72 mN/m) on this mode of atomization is studied by using water-glycerol and water-ethanol mixtures, respectively. An SMD of the order of 40 µm is achieved for a viscosity of 39 cP at a GLR of 0.13 at a liquid pressure of 8 bar and gas pressure of 5 bar. It is observed that the effect of liquid properties is minimal at high GLRs where the liquid jets are broken before the impingement as in the prompt atomization mode. Finally, a pre-filming air-blast technique is explored for transient spray applications. An SMD of 22 µm is obtained with diesel at liquid and gas pressures as low as 10 bar and 8.5 bar, respectively. With this technique, an SMD of 44 µm is achieved for Jatropha oil having a viscosity 10 times higher than that of diesel.

COMMUNICATION STRATEGY PURE PLATINUM FITNESS JATOMI 2014 Objectives: The main objective of this work is to design a communication strategy for the platinum club Pure Platinum Fitness Jatomi for the year 2014. This proposal is based on current applied communication strategies. It is focused on acquiring new customers and communication with existing members, also provides suggestions how to develop cooperation with existing partners. Methods: As the methods were used interview and analysis of documents. Interview method was used in the realization of several interviews with the general manager of the fitness club. Analysis of documents was applied in the preparation of advertising material obtained from the fitness club. Results: The proposal of communication strategy for platinum club Pure Platinum Fitness Jatomi for the year 2014 was based. The proposal brings new ideas, how to acquire new members and shows the possible means leading to the improvement of communication with existing members. It proposes a new modern communication channels that the company could use and invents events for members, through which it is possible to build a relationship that can strengthen loyalty of the members to the club. Keywords: marketing strategy, communication strategy, marketing mix, marketing objectives,...

Relatório de estágio de mestrado em Ciências da Comunicação (área de especialização em Publicidade e Relações Públicas)
O profissional de Relações Públicas tem conseguido, ao longo do tempo, desprender-se do papel de figurante, afirmando-se cada vez mais como um elemento essencial junto das instituições. De acordo com numerosos autores, há igualmente uma crescente necessidade para que as Relações Públicas sejam hoje compreendidas como uma disciplina administrativa, isto é, como um instrumento capaz de executar uma gestão estratégica de relacionamentos entre os vários grupos de stakeholders – internos e externos – de uma qualquer organização. A interdependência entre a organização e os seus públicos cria, então, a necessidade de recorrer às Relações Públicas (Grunig, 2001). Assim sendo, se o sucesso organizacional depende da circulação de informação dentro e fora da instituição e de uma comunicação eficiente entre a chefia e os restantes funcionários, será também oportuno perceber, usufruir e melhorar a comunicação corporativa. É, por isso, importante favorecer um conhecimento alargado sobre esta área comunicacional, tanto no campo académico como no profissional (Kitchen, 2006). Uma das questões que se impõem, porém, é se, de facto, os líderes das organizações permitem ao profissional de Relações Públicas cumprir tal potencial (Moss & Warnaby, 2006). O presente relatório de estágio visa, além de descrever as tarefas desenvolvidas ao longo do estágio curricular, apontar a comunicação corporativa enquanto uma ferramenta-chave para as organizações, dando particular enfoque às Relações Públicas. Tendo como suporte as definições e perspetivas críticas de diversos autores e a própria experiência de estágio, as Relações Públicas serão, então, abordadas como parte integrante da gestão organizacional.
The public relations professional has been able to disassociate itself from the minor role often associated with the profession, increasingly stating it as an essential element among organizations. According to numerous authors, there is also a growing need for public relations to be understood as a management discipline, that is, as a tool capable of performing a strategic management of relationships among the various groups of stakeholders – internal and external – of any organization. The interdependence between the organization and its public generates, thus, the need to turn to public relations (Grunig, 2001). Therefore, if the organizational success depends on the information flow inside and outside the institution as well as on efficient communications between leadership and other employees will also be appropriate to understand, benefit from and improve corporate communications. Consequently, it is important to promote an extensive knowledge on this communicational area, both in the academic and professional fields (Kitchen, 2006). One of the questions emerging from this point of view, however, is whether in fact, organization's leaders allow PR professionals to fulfill such potential (Moss & Warnaby, 2006). The present report, besides describing the tasks carried out throughout the internship, seeks to point out corporate communications as a key tool for organizations, particularly focusing on public relations. Having the definitions and critical perspectives of several authors as also as the internship experience itself as a support for this report, public relations will be, thereby, addressed as a fundamental part of organizational management.

The purpose of this research was to study the lived experience of being a strategic leader, described as the black box of leadership, and to extend the limited research in this field. The researcher utilised the qualitative ethnographic methodology of direct observation, observing 138 discrete critical incidents that made up the lived experience of the five strategic leaders in the sample. The researcher further utilised observation tools from the field of Neuro Linguistic Programming, personal experiences, metaphors, allegories, analogies as well as deep personal introspection to make sense of the lived experience of the five CEOs. The primary research objective was to answer the question: What do CEOs do and how do they do it? A further related objective was to explore how they think about what they do. The research answered these questions by prising open the 'black box' of the lived experience of the strategic leader. The result of the research is the pure leadership spider web model. The pure leadership spider web model breaks down the lived experience of the strategic leader, the content of the black box, into eight dimensions: the pillars that make up the personal leadership philosophy; emotional states of mind brought to bear in meetings; kinaesthetic patterns used during meetings; meeting dynamics; emotional states brought to bear on day-to-day shop-floor engagement; emotional states brought to bear on leadership engagement sessions with other like business leaders; frames of mind governing the day-to-day experiences; and The Magic Language Box.
Business Management and Entr
DBL