This dissertation examines ESPN's SportsCenter's coverage of the NCAA men's basketball tournament bubble. The dissertation examines the differences in coverage between average teams from the six major NCAA Division I men's basketball conferences and teams from the other 25 conferences. The dissertation examines SportsCenter's coverage from an effects method, questioning whether SportsCenter sets the agenda for other news media in terms of national sports coverage, in this case coverage of the NCAA men's basketball tournament bubble. The dissertation also takes an effects method in terms of framing, examining the narratives SportsCenter uses to describe tournament teams and the attributes that SportsCenter chooses to use depending on the conference affiliation of the team. Finally, the dissertation examines SportsCenter's coverage in terms of political economy, concentrating on ESPN's financial ties to the six major conferences and the importance of maintaining a status quo in terms of promoting the superiority of teams from the six conferences compared to teams from the other conferences. Combining the three approaches provides evidence that SportsCenter does tilt its coverage in favor of teams from the six major conferences in order to promote its financial priorities. SportsCenter works to emphasize a perception of superiority among average teams from the six major conferences in order to ensure that its top teams are easily and often exposed to ESPN's coverage and to maintain consistent ratings.

Orientador: Milton Mori / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-20T21:12:35Z (GMT). No. of bitstreams: 1 SanchezForero_DianaIsabel_M.pdf: 2538568 bytes, checksum: 6a7cfe0d2a9575933ee82525a5cec615 (MD5) Previous issue date: 2012 / Resumo: Colunas de bolhas são dispositivos de contato multifásico para transferência de massa e calor, intensamente utilizados em diferentes áreas industriais. O escoamento e a turbulência destes equipamentos são induzidos pelo movimento ascendente das bolhas. A hidrodinâmica e o comportamento das bolhas em regime homogêneo foram analisados em uma coluna de bolhas retangular em escala de laboratório (50 cm x 20 cm x 220 cm), utilizando as técnicas de velocimetria por imagem de partícula (PIV) e a técnica de sombras Shadow para o estudo das fases contínua e dispersa, respectivamente. O gás foi alimentado através de um distribuidor de 18 furos a várias condições de velocidade superficiais de gás na entrada. As propriedades do escoamento para as duas fases foram determinadas por meio de uma quantidade suficiente de imagens duplas. O campo de velocidade para a fase contínua (líquido) foi obtido por adição de partículas traçadoras fluorescentes. Além disso, a intensidade de turbulência, energia cinética turbulenta e os tensores de Reynolds, foram determinados a partir dos dados obtidos pelas medições experimentais. Os resultados mostram o perfil típico da velocidade axial média do líquido, ascendente na região central e descendente nas proximidades das paredes da coluna. Também, foram encontradas diferenças entre os perfis normal e axial dos tensores, o que sugere que o fenômeno turbulento na coluna de bolhas é produzido pelo caráter anisotrópico desta. Finalmente, o comportamento das bolhas foi analisado determinando a distribuição e o tamanho destas. Verificou-se que o tamanho das bolhas decresce ao longo da coluna devido aos efeitos da deformação e fenômenos de coalescência. Igualmente, encontrou-se o diâmetro médio da bolha na faixa dos 4 milímetros, tamanho típico no regime homogêneo / Abstract: Bubble columns are multiphase contact devices for mass and heat transfer, wich are intensively used in different industrial areas. Flow and turbulence in these equipments are induced by the bubble rise motion. The hydrodynamics and bubble behavior in a homogeneous bubbly flow regime was analyzed in a rectangular laboratory-scale bubble column (50 x 20 x 220 cm) using Particle Image Velocimetry (PIV) and Shadow techniques to study continuous and dispersed phase, respectively. The bubble column was aerated by using 18 holes gas sparger for several superficial gas velocities. The flow properties for both phases were determinate by sufficient number of double images. The velocity field for continuous phase (liquid) was achieved by adding fluorescing tracer particles. In addition, turbulence intensities of the fluid, turbulent kinetic energy and tensors profiles were deduced from experimental measurements. Results show typical axial mean velocity profiles of the liquid, upward flow in the core region and a down-flow near the walls. Also, it was found differences between axial and normal tensors profiles that suggest the turbulent phenomena in the bubble column its produced by the anisotropic behavior. Finally the bubble performance was further analyzed by determining bubble distribution and bubble size. It was found a decreasing bubble size along the bubble column due to the coalescence and deformation effects. Furthermore, is determinate that the bubble diameter is around 4 mm, typical bubble size in a homogeneous bubble flow regime / Mestrado / Desenvolvimento de Processos Químicos / Mestra em Engenharia Química

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When a shock interacts with a bubble having a different density than the environment or medium, the interaction causes compression and deformation of the bubble and generation of a vortex pair. Later, secondary vortices appear causing enhanced mixing. The enhanced mixing induced by the shock bubble interactions is particularly of interest in supersonic combustion and detonation. The Wavelet Adaptive Multi-resolution Representation (WAMR) method is particularly suitable for challenging continuum physics problems like shock bubble interaction, which has strong multi-scale character. This method provides an efficient strategy to create a dynamically adaptive spatial grid and to obtain a verified solution. Since the wavelet amplitude provides a first-hand estimate of the local error at each point, the method is able to efficiently capture a wide spectrum of spatial scales by dynamically changing the adaptive grid. Highly resolved computations are done only in the regions where abrupt transition occurs. In this work a detailed investigation of Shock Bubble Interaction (SBI) is carried out using shocks having Mach numbers from 1.2 to 3 for helium, nitrogen and krypton bubbles. Simulations carried out using WAMR method were used to analyze the effects of Mach number and density contrast on the shape, location and velocity of the bubble as well as vorticity and pressure in the flow field.

Experimente mit neuartigen Messverfahren lieferten Daten über die Struktur von transienten Flüssig-keits-Gas-Strömungen für die Entwicklung und Validierung von mikroskopischen, d.h. geometrieunabhängigen Konstitutivbeziehungen zur Beschreibung des Impulsaustauschs zwischen Flüssig-phase und Gasblasen sowie zur Quantifizierung der Häufigkeit von Blasenkoaleszenz und -zerfall. Hierzu wurde eine vertikale Testsektion der Zweiphasentestschleife MTLoop in Rossendorf genutzt, wobei erstmals Gittersensoren mit einer Auflösung von 2-3 mm bei einer Messfrequenz von bis zu 10 kHz angewandt wurden. Dabei wurde die Evolution von Gasgehalts-, Geschwindigkeits- und Bla-sengrößenverteilungen entlang des Strömungsweges und bei schnellen Übergangsprozessen aufge-nommen und so die für die Modellbildung erforderlichen Daten bereitgestellt. Für den Test der Mo-dellbeziehungen wurde ein vereinfachtes Verfahren zur Lösung der Strömungsgleichungen entlang des Strömungswegs erstellt. Es basiert auf der Betrachtung einer größeren Anzahl von Blasengrö-ßenklassen. Die erhaltenen numerische Lösungen haben erstmals gezeigt, dass der bei Erhöhung der Gasvolumenstromdichte stattfindende Übergang von einer Blasenströmung mit Randmaximum zu einem Profil mit Zentrumsmaximum und anschließend zu einer Pfropfenströmung ausgehend von einem einheitlichen Satz physikalisch begründeter und geometrieunabhängiger Konstitutivgleichun-gen modelliert werden kann. Die Modellbeziehungen haben sich in einem abgegrenzten Gebiet der Volumenstromdichten als generalisierungsfähig erwiesen und sind für den Einbau in CFD-Modelle geeignet. Weiterhin wurden Arbeiten zur Kondensation durchgeführt, die direkten Bezug zu den Kon-densationsmodellen haben, die in Thermohydraulik-Codes enthalten sind. Die Untersuchung liefert darüber hinaus experimentelle Daten für die Modellvalidierung hinsichtlich des Verhaltens und des Einflusses nichtkondensierbarer Gase. Hierfür wurden spezielle Sonden für die Bestimmung der Konzentration und für die Lokalisierung von Pfropfen nichtkondensierbarer Gase entwickelt und bei transienten Kondensationsversuchen in einem leicht geneigten Wärmeübertragerrohr eingesetzt.

The performance of ebullated bed hydroprocessors depends on the fluids distribution system and liquid recycle pan. Given that bubbles do not readily coalesce in the bed, the original bubble size distribution generated at the bubble cap distributor likely impacts buoyancy-based phase separation at the recycle pan. Gas entrained in the liquid recycle increases bed gas holdup at the expense of liquid holdup and product yield. The aim of this work was to investigate the impact of gas-liquid distribution system on resulting bubble properties and dynamics and incorporate a distributor sub-model into an existing fluid dynamics model of the industrial hydroprocessor. The size of initial bubbles formed in the plenum chamber was found to have negligible impact on phase holdups above the distributor. However, resulting bubble properties were found to depend on distributor geometry, distributor power dissipation and gas-liquid velocity ratio. In addition, a new set of scaling laws for gas-liquid distributors, based on dimensional analysis and similitude, was proposed. Geometric scaling was based on matching distributor fractional open area and ratios of critical dimensions. Dynamic similarity was based on matching three dimensionless groups and bubble coalescence behaviour. A bubble size distribution model was then developed. Both pressure and distributor were found to have an impact on individual bubble drag coefficients, as they both altered bubble size distribution. A novel drag model was thus also developed at industrially relevant conditions. Finally, a new gas-liquid distributor sub-model, including bubble size distribution and drag models previously developed, was incorporated into an overall fluid dynamics model of the hydroprocessor. The bubble size distribution model was also coupled with existing gas-liquid separation sub-model to better predict recycled gas and liquid fractions. A sensitivity analysis performed with the overall model revealed distributor configurations with potential of improving the processing capacity of the hydroprocessor.

The objective of this research was to characterize the performance of hypolimnetic aerators with respect to oxygen transfer and water flow rate to allow the development of two comprehensive process models. The oxygen transfer model is the first model that applies discrete-bubble principles to a hypolimnetic aerator, and the water flow rate model is the first that applies an energy balance to this particular type of lake aeration device. Both models use fundamental principles to predict hypolimnetic aerator performance, as opposed to empirical correlations. The models were verified with data collected from a full-scale hypolimnetic aerator installed in Lake Prince, which is a water supply reservoir for the City of Norfolk, Virginia. Water flow rate, gas-phase holdup and dissolved oxygen profiles were measured as a function of air flow rate. The initial bubble size was calculated by the oxygen transfer model using field data. The range of bubble diameters obtained using the model was 2.3-3.1 mm. The Sauter mean diameters of bubbles measured in a laboratory system ranged from 2.7-3.9 mm. The riser and downcomer DO profiles and gas holdups predicted by the model are in close agreement with experimental results. The water flow rate model was fitted to the experimental water velocity by varying the frictional loss coefficient for the air-water separator. An empirical correlation that predicts the loss coefficient as a function of superficial water velocity was obtained. The results of the correlation were similar to those predicted by literature equations developed for external airlift bioreactors. / Master of Science

A introduction to metacalibration methods and their application. This includes a new proof of the double bubble conjecture, new results in the area of equitent problems (isoperimetric problems with boundary), and comments on a mapping conjecture.