82 resultados para Plunging breakers
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The article examines the practice known as ‘rooftopping photography’ and its significance for the representation of vertical cities. It begins by charting the historical development of architecture as a viewing platform in the age of the camera, and dwells on the imagery of cityscapes from above that emerged in the inter-war period. Against this background, the essay investigates how rooftopping arose out of the urban exploration movement and became a global trend in the early 2010s. This phenomenon is situated within its wider social and cultural context, and is discussed with reference to the online media discourse that contributed to its public visibility. A set of ideas from the philosophy of photography and visual culture inform the critical analysis of rooftopping photographs: this broad and diverse body of images is examined with a focus on two predominant modes of representation—panoramic and plunging views. The affective responses elicited by so-called ‘vertigo-inducing’ images are discussed through the concept of vicarious kinaesthesia, which offers insights into the nexus between visceral experience and visual representation that lies at the core of rooftopping. By unpacking this interplay, the essay explores a phenomenon that has hitherto been given little scholarly attention and reflects on its broader implications for the relationship between photography and architecture today.
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Thesis (Ph.D.)--University of Washington, 2016-08
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Practical application of flow boiling to ground- and space-based thermal management systems hinges on the ability to predict the system’s heat removal capabilities under expected operating conditions. Research in this field has shown that the heat transfer coefficient within two-phase heat exchangers can be largely dependent on the experienced flow regime. This finding has inspired an effort to develop mechanistic heat transfer models for each flow pattern which are likely to outperform traditional empirical correlations. As a contribution to the effort, this work aimed to identify the heat transfer mechanisms for the slug flow regime through analysis of individual Taylor bubbles. An experimental apparatus was developed to inject single vapor Taylor bubbles into co-currently flowing liquid HFE 7100. The heat transfer was measured as the bubble rose through a 6 mm inner diameter heated tube using an infrared thermography technique. High-speed flow visualization was obtained and the bubble film thickness measured in an adiabatic section. Experiments were conducted at various liquid mass fluxes (43-200 kg/m2s) and gravity levels (0.01g-1.8g) to characterize the effect of bubble drift velocity on the heat transfer mechanisms. Variable gravity testing was conducted during a NASA parabolic flight campaign. Results from the experiments showed that the drift velocity strongly affects the hydrodynamics and heat transfer of single elongated bubbles. At low gravity levels, bubbles exhibited shapes characteristic of capillary flows and the heat transfer enhancement due to the bubble was dominated by conduction through the thin film. At moderate to high gravity, traditional Taylor bubbles provided small values of enhancement within the film, but large peaks in the wake heat transfer occurred due to turbulent vortices induced by the film plunging into the trailing liquid slug. Characteristics of the wake heat transfer profiles were analyzed and related to the predicted velocity field. Results were compared and shown to agree with numerical simulations of colleagues from EPFL, Switzerland. In addition, a preliminary study was completed on the effect of a Taylor bubble passing through nucleate flow boiling, showing that the thinning thermal boundary layer within the film suppressed nucleation, thereby decreasing the heat transfer coefficient.
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What drove the transition from small-scale human societies centred on kinship and personal exchange, to large-scale societies comprising cooperation and division of labour among untold numbers of unrelated individuals? We propose that the unique human capacity to negotiate institutional rules that coordinate social actions was a key driver of this transition. By creating institutions, humans have been able to move from the default ‘Hobbesian’ rules of the ‘game of life’, determined by physical/environmental constraints, into self-created rules of social organization where cooperation can be individually advantageous even in large groups of unrelated individuals. Examples include rules of food sharing in hunter–gatherers, rules for the usage of irrigation systems in agriculturalists, property rights and systems for sharing reputation between mediaeval traders. Successful institutions create rules of interaction that are self-enforcing, providing direct benefits both to individuals that follow them, and to individuals that sanction rule breakers. Forming institutions requires shared intentionality, language and other cognitive abilities largely absent in other primates. We explain how cooperative breeding likely selected for these abilities early in the Homo lineage. This allowed anatomically modern humans to create institutions that transformed the self-reliance of our primate ancestors into the division of labour of large-scale human social organization.
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This picture shows the men of the Detroit Dredging Company hand digging lagoons for owner George A. Boeckling at Cedar Point. The lagoon network would be used for transportation so that visitors could reach the boat docks at the Hotel Breakers. They also made it possible to carry coal to the new electric power station. Visitors could also enjoy traveling the lagoons by themselves.
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Syftet med undersökningen är att med avseende på skolans genusuppdrag studera musiklärares förhållningsätt i ensembleundervisning på gymnasieskolan. För att uppnå detta har kvalitativa, semistrukturerade intervjuer genomförts med lärare i gymnasiekursen ensemble, följt av diskursanalys på transkriberingar av dessa intervjuer. De teoretiska utgångspunkterna är genusteorier och diskursteorier. I resultatet framkommer lärarnas syn på genusbegreppet och genusuppdraget. Bland de genusdiskurser som presenteras finns synen på genus som rutin, som sidoeffekt på annat arbete och som medvetenhet. Gällande elevsyn visar sig diskurser om eleven som platstagare, som normbrytare och vikten av att eleven känner sig som en synbar individ. Slutledningarna, liksom diskussionskapitlet, rör sig kring genusarbetets framgångar, vilka faktorer som kan ha orsakat dessa, och hur arbetet förändrats på skolorna utifrån dessa framgångar. Genomgående har ett individfokus framkommit, där eleverna inte ses som en grupp, utan som enskilda individer, vilka alla måste mötas personligt.
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This thesis deals with the sizing and analysis of the electrical power system of a petrochemical plant. The activity was carried out in the framework of an electrical engineering internship. The sizing and electrical calculations, as well as the study of the dynamic behavior of network quantities, are accomplished by using the ETAP (Electrical Transient Analyzer Program) software. After determining the type and size of the loads, the calculation of power flows is carried out for all possible network layout and different power supply configurations. The network is normally operated in a double radial configuration. However, the sizing must be carried out taking into account the most critical configuration, i.e., the temporary one of single radial operation, and also considering the most unfavorable power supply conditions. The calculation of shortcircuit currents is then carried out and the appropriate circuit breakers are selected. Where necessary, capacitor banks are sized in order to keep power factor at the point of common coupling within the preset limits. The grounding system is sized by using the finite element method. For loads with the highest level of criticality, UPS are sized in order to ensure their operation even in the absence of the main power supply. The main faults that can occur in the plant are examined, determining the intervention times of the protections to ensure that, in case of failure on one component, the others can still properly operate. The report concludes with the dynamic and stability analysis of the power system during island operation, in order to ensure that the two gas turbines are able to support the load even during transient conditions.