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This paper explores value co-creation and value co-destruction with a focus on the social practices embedded in the online brand community “My Starbucks Idea (MSI).” The objectives of the research are accomplished through a detailed explanation of the study’s stages, starting with the Research design/Planning, and followed by the Community Entry (Entrée), Data collection, Limitations, and Ethical implications. Since the study is exploratory in character, the qualitative research strategy was used. As Bryman and Bell (2011) note, qualitative research gives particular attention to words rather than numbers in the gathering and interpretation of data. This study applied a modified ‘netnographic’ approach, a new qualitative method devised specifically to investigate consumer behaviour vis-à-vis cultures and communities present on the Internet (Kozinets 1998). This study identifies three elements of practice: stalking, gossip, and exhibitionism. It also supports the idea stated by Echeverri & Skålén (2011) that there is no positive without a negative in interactive value formation. Although those authors’ work was focused on the provider-customer interface, the idea proves applicable to the online brand community (OBC) used for illustration in this study. The present study also draws attention to a vital characteristic of practice often forgotten: ‘Language’ as an enabler of all other elements (Whittington 2006). The paper contributes to the knowledge in the practice theory domain, and thus consumer culture, especially relating to OBCs. When using OBCs as a marketing tool, considerable ingenuity must be employed by business managers to gain strategic information and feedback from online forum discussions. Such information can help in the company’s strategic decision making. By building relationships and gaining new customers through the process of collaboration, managers can become more like brand storytellers. Also, such communication can be channelled as a means to create greater awareness, both of the brand and the users’ experiences, along with aiding in the development of better services and products to meet customers’ needs. In the current study, consent was an ethical concern that limited the scope and path taken by the paper. The ten-week research period was another limiting factor in properly covering all of the contextualized consumption activities and gaining sufficient experience within the MSI community.

Neste trabalho, propõe-se um modelo numérico-computacional representativo dos processos de tratamento térmico, que seja uma ferramenta eficiente e forneça meios para um entendimento efetivo do mecanismo de geração de tensões residuais durante a têmpera de aços. Foram investigados os fenômenos térmicos, mecânicos e de transformação de fase observados na têmpera, bem como o acoplamento entre esses três fenômenos. O modelo utiliza o Método dos Elementos Finitos (MEF) e o programa ABAQUS®, além de rotinas numéricas em FORTRAN responsáveis pela resolução do problema termo-mecânico-microestrutural acoplado. A utilização de sub-rotinas, que implementam uma alteração na formulação (matemática e numérica) do programa de Elementos Finitos, permite incluir no modelo as informações presentes em uma curva CRC (curva de resfriamento contínuo) do aço SAE 4140, implementando o cálculo de deformações da peça simulada de modo incremental e cumulativo. Os resultados mostram que a utilização das sub-rotinas desenvolvidas neste trabalho permitiu implementar, conjuntamente com o programa ABAQUS®, o cálculo das frações volumétricas, durezas, distorções e tensões que surgem em um tratamento térmico de têmpera, simulando as transformações martensítica, perlítica, bainítica e ferrítica. Os resultados dos modelos foram equivalentes aos relatados pela literatura, principalmente no que se refere às durezas e tensões associadas a cada transformação de fase. Em particular, os resultados indicam que a transformação martensítica está sempre associada à formação de tensões compressivas. Ensaios experimentais foram realizados a fim de validar os modelos computacionais propostos, utilizando-se um teste Jominy adaptado e instrumentado, de modo a permitir a amostragem da variação de temperaturas no material. Ensaios metalográficos permitiram correlacionar as frações volumétricas transformadas durante a têmpera do corpo de prova Jominy aos valores calculados pelo modelo numérico acoplado. / The objective of this work is to analyze residual strains and stresses and volumetric expansion due to phase transformations that occur during quenching of a steel body, as well as to predict these phase transformations. The coupled thermo-mechanical-phase transformation problem was analyzed, specifically in terms of the quenching process. Different computational models were presented, based on the finite element software ABAQUS® and on the use of FORTRAN subroutines. The continuous-cooling-transformation (CCT) diagrams of SAE 4140 steel are represented differently in each model, depending on the transformed phases and correspondent volumetric expansion. These subroutines include information from the CCT diagrams of SAE 4140 into a FORTRAN code. The subroutine calculates all the microstructures resulting from quenching (ferrite, pearlite, bainite, and martensite), depending on cooling rate. The numerical analysis conducted in this work provided results in terms of the temperature and stresses developed during quenching. The properties determined in this work are hardness, yield strength, volumetric fraction and distortion. Hardness has been predicted by the use of analytical equations. The finite element analyses were able to explain and reproduce phenomena observed during quenching of a steel cylinder. In particular, numerical results indicated that martensite formation is always related to a compressive stress field. The results of the models are in qualitative agreement with data provided by literature, particularly, in relation to the stresses originated by each different phase transformation during quenching process. Experimental testing was conducted, based on the analysis of the quenching of a Jominy probe, in order to validate the computational model developed in this work.

Este trabalho tem por objetivo caracterizar e comparar as microestruturas de diferentes regiões de uma chapa de aço microligado para tubo API 5L X65, empregado no transporte de gás natural e petróleo, como recebido e submetido a tratamentos térmicos de austenitização e resfriamento contínuo sob diferentes taxas de resfriamento. O aço em estudo apresenta uma linha de segregação central, originada durante o processo de produção do aço. Corpos de prova de dilatometria foram usinados da região central e de outras regiões da chapa. As amostras foram previamente austenitizadas a 1200°C e temperadas em água, visando solubilizar grande parte dos precipitados presentes no aço. Após este tratamento, as amostras foram austenitizadas em um dilatômetro de têmpera a 950°C por 180s, e em seguida resfriadas nas seguintes taxas de resfriamento: 0,5°C/s, 1°C/s, 5°C/s, 10°C/s, 20°C/s, 30°C/s, 40°C/s, 50ºC/s e 60ºC/s. Valores de temperatura e tempo correspondentes a inflexões da curva dilatométrica foram obtidas e correlacionadas com a microestrutura, para cada taxa de resfriamento. Com base nesta análise foi traçado um diagrama de Transformação por Resfriamento Contínuo (TRC) do material. / This work aims to characterize and compare the microstructures of different regions of a plate of microalloyed pipeline steel that conforms to API 5L X65, employed in the transportation of natural gas and oil, as received and after being subjected to heat treatments of austenitization and continuous cooling under different cooling rates. The steel under study presents a central line of segregation that was originated during production. Specimens for dilatometry were machined from the central region and from different regions of the plate. The samples were austenitized at 1200°C and in quenched in water, with the purpose of solubilizing most of the precipitates in the steel. After the preliminary heat treatment, the specimens were austenitized at 950°C for 180s and cooled under the cooling rates: 0.5°C/s, 1°C/s, 5°C/s, 10°C/s, 20°C/s, 30°C/s, 40°C/s, 50ºC/s and 60ºC/s in a quench dilatometer. Values of temperature and time correspond of transformation for each rate of cooling were used for the determination of the Continuous Cooling Transformation (CCT) diagram.

For six decades, consumer researchers have relied heavily on Goffman's (1963) seminal work on stigma, often limiting themselves to a one-dimensional treatment of it as a static variable that determines the behaviour of homogenous groups. Such views, however, stand at odds with wider paradigm shifts away from modernity, and with feminist considerations about intersectionality. Most importantly, the dearth of studies examining the interplay between structural macro-dynamics and micro-level experiences has meant that rapid changes in societal attitudes have received insufficient attention. Considering the rise of minority portrayals in the past few years and importance of the media in dispersing and ameliorating stigma, there is a need to understand how media experiences differ across generations, sociocultural categories, and individual life-courses. Focusing on lesbian, gay, bisexual, trans, queer, and other (LGBTQ+) individuals, and building on Bauman's (2000) concept of liquid modernity as well as Bourdieu's (1994) theory of practice, this thesis explores how stigma experiences of two generations of LGBTQ+ consumers have changed, how this relates to their experiences of LGBTQ+ media portrayals, as well as what this tells us about how (marginalised) consumers navigate their lives and particularly the fragmentation of identity politics through (media) consumption. I followed an intersectional phenomenological enquiry, employing a meaning-based model of media experience that contributes to the literature by extending Mick and Buhl's (1992) work to account for considerations of intersectionality and intertextuality. Life story- and subsequent media experience interviews were analysed individually and across cases. The sample consisted of eight LGBTQ+ members of the Boomer- and ten of the Millennial generation. This study develops a theoretical framework of stigma as viscous instead of static: in constant flux due to the dynamic interplay between the doxic attitudes in social fields, as well as individual embodied dispositions, the stigma habitus. This provides a richer understanding of how it is enacted in consumer culture, enabling a critical analysis of the dialectic relationship between individuals and their environment. Through this framework, my study challenges generational accounts of difference, which are found to be too simplistic to account for diverging (media) experiences. Instead, it is the dialectic between context and (stigma) habitus that shapes dynamic experiences. For participants facing high levels of stigma viscosity, for example, LGBTQ+ portrayals seemed particularly important and experiences revolved around social acceptance. Moreover, lived experiences, as well as doxic beliefs about media, advertising, and a text's 'author' formed an intertextual frame of reference used to evaluate portrayals' authenticity and harmfulness. Importantly, participants' preference for or rejection of 'radical' vs heteronormative portrayals was shaped by tastes that have become naturalised in their habitus, with disparate doxic beliefs generating reflexive guilt and ambivalence. My findings suggest that stigma amelioration may ultimately lead to symbolic violence within the LGBTQ+ community against those who do not adhere to accepted consumption standards. This study also has implications for consumers more broadly as changes in viscosity affect consumption practices. Adhering to a critical approach, I describe a range of recommendations for practitioners and reflexive practices I engaged in following this study.

Non-metallic inclusions in steels are generally considered to be detrimental for mechanical properties. However, it has been recognized that certain inclusions, such as Ti-oxide and TiN, can serve as potent nucleation sites for the formation of intragranular ferrite (IGF) in low-alloy steels. The formation of IGF could improve the toughness of the coarse grained heat affected zone (CGHAZ) of weld metals. Thus, the present thesis mainly focuses on the effect of size of nucleation sites on the IGF formation. Quantitative studies on the composition, size distribution and nucleation probability for each size of the inclusions as well as the area fraction, starting temperature and morphology of an IGF have been carried out. In the present work, the Ti-oxide and TiN powders were mixed with metallic powders. The mixed powders were heated up to the liquid state and cooled with a slow cooling rate of 3.6 ºC/min. These as-cast steels with Ti-oxide and TiN additions were used to simulate the IGF formation in the CGHAZ of weld metals. Specifically, the inclusion and microstructure characteristics in as-cast steels have been investigated. The results show that the nucleant inclusion was identified as a TiOx+MnS phase in steels with Ti2O3 additions and as a TiN+Mn-Al-Si-Ti-O+MnS phase in steels with TiN additions. In addition, the TiOx and TiN phases are detected to be the effective nucleation sites for IGF formation. It is clearly shown that an increased inclusion size leads to an increased probability of IGF nucleation. This probability of IGF nucleation for each inclusion size of the TiOx+MnS inclusions is clearly higher than that of the complex TiN+Mn-Al-Si-Ti-O+MnS inclusions. In addition, the area fraction of IGF in the steels with Ti2O3 additions is larger than that of the steels with TiN additions. This result agrees with the predicted tendency of the probability of IGF nucleation for each inclusion size in the steels with Ti2O3 and TiN additions. In order to predict the effective inclusion size for IGF formation, the critical diameters of the TiO, TiN and VN inclusions, which acted as the nucleation sites of IGF formation, were also calculated based on the classical nucleation theory. The critical diameters of TiO, TiN and VN inclusions for IGF formation were found to be 0.192, 0.355 and 0.810 μm in the present steels. The calculation results were found to be in agreement with the experiment data of an effective inclusion size. Moreover, the effects of the S, Mn and C contents on the critical diameters of inclusions were also calculated. It was found that the critical diameter of the TiO, TiN and VN inclusions increases with an increased content of Mn or C. However, the S content doesn’t have a direct effect on the critical diameter of the inclusions for IGF formation. The probability of IGF nucleation for each inclusion size slightly decreases in the steel containing a higher S content. This fact is due to that an increased amount of MnS precipitation covers the nucleant inclusion surface. In the as-cast experiment, it was noted that an IGF can be formed in steels with Ti2O3 and TiN additions with a cooling rate of 3.6 ºC/min. In order to control the microstructure characteristics, such as the area fraction and the morphology of an IGF, and to investigate the starting temperature of IGF and grain boundary ferrite (GBF) formation, the dynamic transformation behavior of IGF and GBF was studied in-situ by a high temperature confocal laser scanning microscope (CLSM). Furthermore, the chemical compositions of the inclusions and the morphology of IGF after the in-situ observations were investigated by using scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and electron probe microanalysis (EPMA) which equipped wavelength dispersive spectrometer (WDS). The results show that the area fraction of IGF is larger in the steels with Ti2O3 additions compared to the steels with TiN additions, after the same thermal cycle has been imposed. This is due to that the TiOx phase provides more potent nucleation sites for IGF than the TiN phase does. Also, the area fraction of IGF in the steels is highest after at an intermediate cooling rate of 70 ºC/min, since the competing phase transformations are avoided. This fact has been detected by using a hybrid methodology in combination with CLSM and differential scanning calorimetry (DSC). In addition, it is noted that the morphology of an IGF is refined with an increased cooling rate. / <p>QC 20150325</p>

Nowadays, power systems are dealing with some new challenges raisedby the major changes that have been taken place since 80’s, e.g., deregu-lation in electricity markets, significant increase of electricity demands andmore recently large-scale integration of renewable energy resources such aswind power. Therefore, system operators must make some adjustments toaccommodate these changes into the future of power systems.One of the main challenges is maintaining the system stability since theextra stress caused by the above changes reduces the stability margin, andmay lead to rise of many undesirable phenomena. The other important chal-lenge is to cope with uncertainty and variability of renewable energy sourceswhich make power systems to become more stochastic in nature, and lesscontrollable.Flexible AC Transmission Systems (FACTS) have emerged as a solutionto help power systems with these new challenges. This thesis aims to ap-propriately utilize such devices in order to increase the transmission capacityand flexibility, improve the dynamic behavior of power systems and integratemore renewable energy into the system. To this end, the most appropriatelocations and settings of these controllable devices need to be determined.This thesis mainly looks at (i) rotor angle stability, i.e., small signal andtransient stability (ii) system operation under wind uncertainty. In the firstpart of this thesis, trajectory sensitivity analysis is used to determine themost suitable placement of FACTS devices for improving rotor angle sta-bility, while in the second part, optimal settings of such devices are foundto maximize the level of wind power integration. As a general conclusion,it was demonstrated that FACTS devices, installed in proper locations andtuned appropriately, are effective means to enhance the system stability andto handle wind uncertainty.The last objective of this thesis work is to propose an efficient solutionapproach based on Benders’ decomposition to solve a network-constrained acunit commitment problem in a wind-integrated power system. The numericalresults show validity, accuracy and efficiency of the proposed approach. / <p>The Doctoral Degrees issued upon completion of the programme are issued by Comillas Pontifical University, Delft University of Technology and KTH Royal Institute of Technology. The invested degrees are official in Spain, the Netherlands and Sweden, respectively.QC 20141028</p>

Submitted by Leandro Ruiz Machado (leandromachado@columbia.com.br) on 2014-03-06T01:20:13Z No. of bitstreams: 1 Dissertação_ V15_20140305 - Versão Final.pdf: 1843274 bytes, checksum: eee08685c0f2ab2bfb6c985bf7585b12 (MD5) / Rejected by Suzinei Teles Garcia Garcia (suzinei.garcia@fgv.br), reason: Prezado Leandro Ruiz, A ficha catalográfica falta o número do CDU. Link abaixo para solicitar a ficha. http://bdigital.bibliotecas.fgv.br/ficha_catalografica Att. Suzi 3799-7876 on 2014-03-06T14:08:14Z (GMT) / Submitted by Leandro Ruiz Machado (leandromachado@columbia.com.br) on 2014-03-07T19:48:38Z No. of bitstreams: 1 Dissertação_ V15_20140305 - Versão Final.pdf: 1859188 bytes, checksum: 99388b1185ce2ee447c33ca0411f6959 (MD5) / Approved for entry into archive by Suzinei Teles Garcia Garcia (suzinei.garcia@fgv.br) on 2014-03-10T11:52:56Z (GMT) No. of bitstreams: 1 Dissertação_ V15_20140305 - Versão Final.pdf: 1859188 bytes, checksum: 99388b1185ce2ee447c33ca0411f6959 (MD5) / Made available in DSpace on 2014-03-10T11:55:08Z (GMT). No. of bitstreams: 1 Dissertação_ V15_20140305 - Versão Final.pdf: 1859188 bytes, checksum: 99388b1185ce2ee447c33ca0411f6959 (MD5) Previous issue date: 2014-02-07 / O objetivo deste trabalho foi dimensionar o sistema de corte, carregamento e transporte do eucalipto (CCT) para uma empresa florestal localizada no Oeste Baiano com a finalidade de processar a madeira para queima como biomassa. O sistema considerado foi o chamado 'Americano', que conta com o feller-buncher (corte), o skidder (arraste), o processador florestal (processamento), o carregador florestal (carregamento e descarregamento) e o caminhão (transporte). Os custos encontrados nos equipamentos envolvidos neste processo foram somados, visando-se identificar o módulo padrão, representado pelo conjunto com a maior produtividade e o menor custo, obtendo-se, desta forma, a maior margem sobre o valor da venda da madeira. Os resultados encontrados indicam que o custo de CCT, a partir do módulo padrão de processamento de madeira de 40.000 m3/mês, oscilou entre 26,60% e 34,36% do valor da madeira entregue ao cliente final, dependendo da região onde a mesma é comercializada. Dessa forma, os resultados encontram-se em níveis médios sugeridos pela literatura. Outro ponto que reforça a importância de se analisar estes custos operacionais, é que entre 65,64% e 74,40% do custo de venda da madeira entregue foi formado no período de 5 a 7 anos (prazo de crescimento médio de uma árvore de eucalipto, dependendo da finalidade da utilização da madeira), enquanto que a diferença é formada em apenas 60 dias, prazo este correspondente ao corte, carregamento e transporte desta madeira até o cliente final. Foi feita a análise de sensibilidade das principais variáveis identificadas. Os resultados revelaram que a distância percorrida de ida e volta para entregar a madeira ao cliente final foi a variável que mais impactou na oscilação do custo final do CCT. O aumento ou a redução dos dias trabalhados por mês e o aumento ou a diminuição da produtividade mensal foram as outras duas variáveis que se demostraram mais sensíveis nesta formação de custo. / The aim of this study was to scale the system of cutting, loading and transportation of eucalyptus (CCT) for a forestry company located in the West of Bahia in order to process the wood to biomass burning. The system considered was the so-called "American System", which consists of the feller buncher (cut), the skidder (drag), the forestry processor (processing), forestry loader (loading and unloading) and the truck (transport). The identified equipment costs involved in this process were added up, in order to identify the standard module, which is represented by the set with the highest productivity and lowest cost, obtaining thus the largest margin of the sales value of the wood. The found results indicate that the costs of CCT, from the standard module timber processing of 40,000 m3 per month, reached between 26.6% and 34.36% of the value of the wood delivered to the end customer. The variation of percentage depends on the region where the respective customer operates. Thus, the results are average levels, suggested by the literature. Another point that underscores the importance of analyzing these operating costs, is that 65.64% - 74.40% of the selling costs of delivered wood are formed in the period of 5-7 years (which is the average growth period of a eucalyptus tree, according to the intended use of the wood), while the remaining percentage is formed in just 60 days, this period corresponds to the cutting, loading and transport of the timber to the end customer. The sensitivity analysis of the identified key variables was made. The results reveal that the way of the outbound of the wood to the end-customer and the way of coming back are the main variables to impact the percentage variation of the final CCT costs. The increase or reduction in days worked per month and the increase or decrease of the monthly yield, were the other two variables that appeared to be more sensitive in the process of cost accumulation.