1,460 research outputs found
The synthesis of monodisperse alkanes with long chains
No full textThis thesis discusses reasons for the interest in monodisperse long chain alkanes and describes attempts, past and present, to synthesise such molecules. Chapter 1 discusses why the synthesis of such molecules are important and the objectives of this project. Chapter 2 reviews the methods previous groups have devised to prepare pure samples of long chain alkanes. In particular, work carried out by Whiting et al. at Bristol, whose scheme formed the basis of the early work in Durham. Chapter 3 describes the work in Durham and improvements which were made to Whiting's method, allowing the synthesis of longer chain lengths and greater quantities of materials to be achieved. Chapter 4 provides a summary of the practical work carried out by the author. Chapter 5 gives experimental details of the work described in Chapter 4
Microstructure Development during Solidification of Aluminium Alloys
No full textThis Thesis demonstrates studies on microstructure development during the solidification of aluminium alloys. New insights of structure development are presented here. Experimental techniques such as quenching and in-situ High-brilliance X-ray microscopy were utilized to study the microstructure evolution during solidification.Materials Science and EngineeringMechanical, Maritime and Materials Engineerin
Characterization of the reaction environment in a filter-press redox flow reactor
No full textThe characteristics of a divided, industrial scale electrochemical reactor with five bipolar electrodes (each having a projected area of 0.72 m2) were examined in terms of mass transport, pressure drop and flow dispersion. Global mass transport data were obtained by monitoring the (first order) concentration decay of dissolved bromine (which was generated in situ by constant current electrolysis of a 1 mol dm?3 NaBr(aq)). The global mass transport properties have been compared with those reported in the literature for other electrochemical reactors. The pressure drop over the reactor was calculated as a function of the mean electrolyte flow velocity and flow dispersion experiments showed the existence of slow and fast phases, two-phase flow being observed at lower velocities
Electron temperature fluctuations associated with the weakly coherent mode in the edge of I-mode plasmas
No full textNew measurements of electron temperature fluctuations associated with the weakly coherent mode (WCM) during improved mode, or I-mode plasmas (Whyte et al 2010 Nucl. Fusion. 50 105005) at Alcator C-Mod (Marmar et al 2007 Fusion. Sci. Technol. 51 3261) are presented in this paper. The measurements are made with a 32-channel, high-resolution profile electron cyclotron emission radiometer. The WCM electron temperature fluctuations are localized to a 1 cm region inside the last closed flux surface. The WCM electron temperature fluctuation level is measured in several different I-mode discharges and is in the range 1% [~ over T][subscript e/T[subscript e] < 2%, which is an order of magnitude smaller than the WCM density fluctuation level. The WCM edge fluctuations observed in I-mode are believed to play a role in increasing particle transport but not energy transport in the edge of I-mode plasmas. The large difference between normalized density and electron temperature fluctuation amplitudes provides new evidence that the WCM fluctuations can separately affect energy and particle transport.United States. Dept. of Energy (DE-FC02-99-ER54512-CMOD
On the consequences of neutron induced damage for volumetric fuel retention in plasma facing materials
No full textD.G. Ritchie's ethics
No full textThe British idealists of the late 19th and early 20th century are best known for their contribution to metaphysics, logic, and political philosophy. Yet they also made important contributions to social and public policy, social and moral philosophy and moral education, as shown by this volume.book chapterpublished
Painting in Poetry and Poetry in Painting: Aesthetic Reflections in D.G. Rossetti
No full textBright eyed and bushy-tailed poems and paintings are very rare, so are their past masters who create them. The history of the world literature is often brimming with such rare authors as are the unparalleled amalgamator of paintings and writings. In this field, the names, which are counted highly with boundless esteem, are of William Blake, Lewis Carroll, Hans Christian Andersen, Elizabeth Bishop, Leo Tolstoy, Lorraine Hansberry, Victor Hugo, Sylvia Plath, George Sand, Jack Kerouac, Herman Hesse, Gunter Grass, Charles Bukowski, Henry Miller, William S. Burroughs, E.E. Cummings, Tennessee Williams, Carlo Levi, J.B. Priestley, and R.N. Tagore. Undisputedly, D.G. Rossetti is one such figure. When the world literature is deconstructed, two clusters of the authors appear on the literary landscape. The first cluster consists of those authors who are painters and writers as well. The painters who have painted the literary pieces of the authors fall into the second cluster. D.G. Rossetti somewhere stands in- between. He is painter (especially illustrator) as well author-poet. But the flabbergasting certitude is that his elite poetry is found in his pieces of mural, and his elite mural in his pieces of poesy. His all creations, be they paintings, or poems, fall in three categories. In the first faction fall such pieces of his poems as are only poems—without any illustration, in the second faction fall such pieces of his paintings as are without poems, while in the third faction fall such pieces of his paintings as are with poems, or with mythical illustrations, or on certain literary pieces. Nothing to say about these groups, but one thing is clear that all of them possess aesthetic reflections. Keeping this very fact in mind, the present article aims at exploring, analyzing, and presenting the three-dimensional view in Rossetti painting and poetry with the help of the textual analysis, visual methods, and descriptive and explorative approach
Classifying sediments on Dutch riverbeds using multi-beam echo-sounder systems
No full textThe economic importance of the Dutch rivers is very high as they are heavily used for inland waterway transport between the Netherlands and their neighbouring countries. A minimum depth must be guaranteed to keep the rivers navigable but also to ensure that the ships can carry maximum cargo. An attractive system for obtaining information about the riverbed bathymetry is the multi-beam echo-sounder (MBES). Furthermore, the MBES received echoes due to acoustic backscatter from the sediments in theory also allow for discriminating between different sediments. The aim of the research presented in this thesis was to develop methods for discriminating between different river sediments using MBES measurements. In order to fulfil this aim, MBES surveys were performed in the Rhine river and the Meuse river between 2007 and 2010. The research shows that indeed the MBES system can be used for discriminating between the different sediments present in the river areas. In addition an important finding is that areas differing in sediment type require different classification approaches.Air Transport and OperationsAerospace Engineerin
Aircraft noise calculation and synthesis in a non-standard atmosphere
No full textThe atmosphere modifies the emitted sound waves of an aircraft during propagation and is therefore important in the calculation of noise contours or synthesis. Noise contours present the resulting noise levels on the ground and are, as such, often applied for regulatory purposes. Aircraft noise synthesis is a technique that allows to transform a calculated prediction into audible sound that can be experienced in a virtual reality environment. Noise synthesis techniques allow people to be subjected to aircraft, routes or procedures that are still being designed. This dissertation describes recent research to improve the modeling of atmospheric propagation effects in aircraft noise contours as well as aircraft noise synthesis. Multi-event noise contours are usually calculated with standardized models that take non-standard propagation into account in an empirical fashion. A propagation algorithm was developed to augment such a model. Signal processing steps can be applied to transform a source noise prediction into an audible result. Furthermore, such steps can be utilized to apply propagation effects to a source noise signal. For a non-standard atmosphere this is not trivial. The role of a non-standard atmosphere is described by a dedicated simulation framework developed in this dissertation. The framework is applied to a flyover to demonstrate the effects associated with multiple ray paths and shadow zones. Besides demonstrating non-standard atmospheric effects, the framework was used to create synthesized results of actual flyovers near an airport. Subsequently, a comparison between measured results and synthesized results was executed. Furthermore, a method was designed to include the effect of turbulence-induced coherence loss of the direct and ground reflected ray in noise synthesis.Aircraft Noise & Climate EffectsAerospace Engineerin
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