Analogy based modeling of natural convection

This research is an extension of previous work on the development of an integrator or resistance-capacitance circuit analogy for natural convection. As a part of a larger project to enhance transport phenomenon on a micro-scale using radiation, this work studied the phenomenon of natural convection. Using experimental techniques and numerical simulations (FLUENT code), it investigated the transient response of a natural convection system. It proposes an integrator circuit analogy for a natural convection system. Experimental investigation with three different fluids indicated that the characteristic time constant of the system is related to the Prandtl number of the fluid. The project also investigated the effect of gravity and fluid viscosity --Abstract, page iv

From behind the lens in a familiar place: Reflections on using photography to explore gentrification in Los Angeles

As I would assume many do, I found field research by far the most exciting part of the PhD experience. During the fieldwork stage not only was I released from the isolating process of reading, writing, and project planning, but I was able to watch theories, hunches, and answers come alive. It was the point where my relationship with the subject was most intimate and most revealing. The photographs that I took during fieldwork were a reflection of this intimacy, and were indeed the glue that held my data together. However snapping these images did not come without unexpected moments and a few lessons learnt, even in a location in which I could not have been more familiar. Here I reflect a bit on my time in Los Angeles making my way through the neighbourhood of Silver Lake with a camera in hand, and an open mind, writes Juliet Kahne

Experimental and computational investigation of flow of pebbles in a pebble bed nuclear reactor

The Pebble Bed Reactor (PBR) is a 4th generation nuclear reactor which is conceptually similar to moving bed reactors used in the chemical and petrochemical industries. In a PBR core, nuclear fuel in the form of pebbles moves slowly under the influence of gravity. Due to the dynamic nature of the core, a thorough understanding about slow and dense granular flow of pebbles is required from both a reactor safety and performance evaluation point of view. In this dissertation, a new integrated experimental and computational study of granular flow in a PBR has been performed. Continuous pebble re-circulation experimental set-up, mimicking flow of pebbles in a PBR, is designed and developed. Experimental investigation of the flow of pebbles in a mimicked test reactor was carried out for the first time using non-invasive radioactive particle tracking (RPT) and residence time distribution (RTD) techniques to measure the pebble trajectory, velocity, overall/zonal residence times, flow patterns etc. The tracer trajectory length and overall/zonal residence time is found to increase with change in pebble\u27s initial seeding position from the center towards the wall of the test reactor. Overall and zonal average velocities of pebbles are found to decrease from the center towards the wall. Discrete element method (DEM) based simulations of test reactor geometry were also carried out using commercial code EDEM and simulation results were validated using the obtained benchmark experimental data. In addition, EDEM based parametric sensitivity study of interaction properties was carried out which suggests that static friction characteristics play an important role from a packed/pebble beds structural characterization point of view. To make the RPT technique viable for practical applications and to enhance its accuracy, a novel and dynamic technique for RPT calibration was designed and developed. Preliminary feasibility results suggest that it can be implemented as a non-invasive and dynamic calibration methodology for RPT technique which will enable its industrial applications. --Abstract, page iii

Hormonal and follicular responses to steroid treatment administered during emergence of the first follicle wave in dairy heifers

Abstract Not Provided

Le Monde on the Algerian War under the Fourth Republic: a study of the newspapers's coverage (1944-1958)

This work is concerned with the coverage of Le Monde during a troubled historical phase: the Algerian war under the Fourth Republic. The Algerian war, Le Monde and the French Fourth Republic are all keypoints of reference in French political life and cultural. Based on a corpus representing the entire output of Le Monde, this thesis sets out to examine Le Monde's claims that it was at the forefront of the decolonisation struggle. The methodology used is that provided by Laswell's investigative programme, Who says what, to whom and with what effect, updated and adapted for this purpose. The thesis uncovers the newspaper's bias in the portrayal and discussion of the protagonists: the armym the FLN and the civilian populations on both sides of the Mediterranean. An important dimension of the analysis relates to the coverage of civil liberties and the paper's position on the use of wide-scale repression and torture; and discusses the implications for press freedom. The analysis shows that in many respects these were undefended and their champions sacrificed on the altar of national interests and Raison d'Etat. The conclusions reached challenge the view that Le Monde's coverage was critical of government and authority over Algeria, particularly Guy Mollet's administration. The analysis shows how progressive and challenging views propounded by some intellectuals were rejected, or minimised in favour of a more traditional and reforming discourse which did not seriously undermind French prestige. The overall conclusion reached, contrary to conventional wisdom, is that Le Monde did not construct a view of the Algerian war under the Fourth Republic that was fundamentally different from that propounded and circulated by official sources notably by the military. This analysis challenges an on-going myth, that Le Monde's position was both radical and pro independence. This work, written primarily with the British social scientist in mind, combines insight from the historian, the political scientist and the media analyst. It gives priority to the political and historical - rather than linguistic - aspects. It is the only work to span the whole of the Fourth Republic, and the only contribution in English to comprehensively address the political and historical context of Le Monde

Le Monde on the Algerian War under the Fourth Republic A study of the newspapers's coverage (1944-1958)

SIGLEAvailable from British Library Document Supply Centre- DSC:DX178867 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Analogy Based Modeling for Natural Convection [abstract]

Only abstract of poster available.Track I: Power GenerationNatural convection is an important phenomenon for many engineering systems including nuclear reactors. Present day nuclear reactors rely on the phenomenon for decay heat removal. While advanced CANDU-X would incorporate natural circulation for enhanced passive heat removals system to ensure safety, while other GEN IV designs also use natural convection as their main mode of heat removal. For this reason, transient analysis of natural convection has been an area of significant interest. As a part of our larger project to enhance transport phenomenon at the micro-scale using radiation, we studied the phenomenon of natural convection. Using experimental techniques and numerical simulation (FLUENT code) transient response of a natural convection system was investigated. An Integrator Circuit analogy was proposed for natural convection system. Experimental investigation with three different fluids indicated that the characteristic time constant of the system is related to the Prandtl number of fluid. Moreover, effect of gravity and fluid viscosity were also investigated. Simulations results suggest that natural convection system acts as a “Low Pass” filter. Transmission characteristics of natural convection system were found to be a function of both fluid properties and the flow characteristics. Transmission factor was found to be a strong function of temperature oscillation frequency. Our numerical simulations also suggested that in additional to the thermal energy stored in the system, for natural convection energy is also stored in the form of kinetic energy of the fluid set in motion due to buoyancy. This energy is found to be related to system's Rayleigh number