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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
741

Occupy Wall Street as radical democracy : Democracy Now! reportage of the foundation of a contemporary direct-democracy movement

Schirmer, Davis January 2013 (has links)
Democracy Now! is an independently syndicated hour long daily audio and video program that is broadcast on 1179 radio, television, and internet stations throughout the world, as well as being freely available on their website under a Creative-Commons License. They are a global news organization based in New York City, with the stated goal of providing “rarely heard” perspectives in their coverage. Democracy Now! was one of the early independent news organizations to provide continuous coverage of the Occupy Wall Street protest in New York's Zuccotti park. Their early coverage of the movement is relevant to the extent that it helps to obviate the demographics of the OWS movement as well as highlight the potential for a “radically-democratic agonistic pluralism,” as conceptualized by Ernesto Laclau and Chantal Mouffe. Through the dual frames of discourse and intersectionality theories, this qualitiative study examines the coverage of Occupy Wall Street by Democracy Now!, in an attempt to understand the interplay of the movement's demographic heterogeneity and the manner in which its public antagonism is characterized by this independent media outlet. The sociopolitical and historical context provided by Democracy Now! is used to understand where the outlet exists with in the media as well as if this coverage can be part of “radical democratic possibilities.”
742

Experimental and Numerical Investigation of Three-Dimensional Laminar Wall Jet of Newtonian and Non-Newtonian Fluids

Adane, Kofi F. K. 09 February 2010 (has links)
A research program was designed to investigate the characteristics of three-dimensional laminar wall jet flow of both Newtonian and two shear-thinning non-Newtonian fluids. The non-Newtonian fluids were prepared from xanthan gum solutions of various concentrations. Both experimental and numerical methodologies were employed in this study. The wall jet was created using a circular pipe of diameter 7 mm and flows into an open fluid tank. The initial Reynolds numbers based on the pipe diameter and jet exit velocity ranged from 250 to 800. The velocity measurements were conducted using a particle image velocimetry technique. The measurements were conducted at several streamwise locations to cover both the developing and self-similar regions. For the numerical study, the complete nonlinear Navier-Stokes equation was solved using an in-house colocated finite volume based CFD code. A Carreau model was employed for the non-Newtonian fluids. The viscosity in the governing equations was obtained explicitly. From the PIV measurements and CFD results, velocity profiles and jet half-widths were extracted at selected downstream locations to study the effects of Reynolds number and specific fluid type on the jet characteristics. It was observed that the numerical results are in reasonable agreement with the experimental data. The decay of maximum velocity, jet spread rates, skin friction coefficient, streamwise velocity profiles, and secondary flows depend strongly on the initial Reynolds number irrespective of the fluid. The results also show that the jet spreads more in the spanwise direction than in the transverse direction in the early flow development whereas the reverse is true in the downstream region. Important differences were observed when the results for the non-Newtonian fluids were compared with those for Newtonian fluid.
743

Experimental investigation of effective modulus of elasticity and shear modulus of brick masonry wall under lateral load

Akhi, Taohida Parvin 03 1900 (has links)
The primary objective of this research program was to investigate the effective modulus of elasticity and shear modulus of brick masonry walls under lateral load, and to to justify using the Jaeger and Mufti method to calculate the effective modulus of elasticity and shear modulus of brick masonry walls. The experimental program involved the testing of three unreinforced brick masonry walls under in-plane and vertical loads. Linear Variable Differential Transducers were used to record the horizontal and vertical displacements of the walls. The experimental results were used to evaluate the modulus of elasticity and the shear modulus of walls under flexure. The experimental results were compared to the finite element analysis results. It was found that the finite element analysis yields similar results to the experimental results. It was also found that the Jaeger and Mufti method to calculate effective modulus of elasticity and shear modulus of brick masonry walls is effective for design purposes.
744

Leptin and cardiovascular function in African and Caucasian men and women : the SABPA study / Pieterse, C.

Pieterse, Chiné January 2011 (has links)
Forensiese assesseringstegnieke wat tydens ondersoeke na kinder seksuele misbruik benut word, het in n hoë mate mettertyd ontwikkel. Navorsing het n waardevolle bydrae gelewer tot effektiewe en geskikte assesseringstegnieke. Verdere navorsing is egter nodig om die bestaande tegnieke te ondersoek. Die persoon wat by forensiese assesserings betrokke is, kan baat vind by die leiding wat navorsing bied. Op grond hiervan het die navorser ondersoek ingestel na die forensiese assesseringstegnieke wat tans in die praktyk deur forensiese maatskaplike werkers benut word. Gedurende die ondersoek is verskeie tegnieke wat tydens forensiese assesseringsonderhoude benut word, geïdentifiseer en bespreek. Die sistematiese aanrakingseksplorasie is vir die doel van hierdie studie deur die navorser uitgesonder. Hierdie tegniek is aan die hand van n gevallestudie bestudeer en bespreek. Ondersoek is ook ingestel na die menings van maatskaplike werkers wat in die forensiese veld werksaam is, asook dié van justisie–amptenare, onder wie landdroste en staatsaanklaers, wat in die hof vir seksuele misdrywe werksaam is, ten opsigte van die benutting van die sistematiese aanrakingseksplorasie. Die justisie–amptenare was aanvanklik nie vertroud met die tegniek nie. Nadat literatuur vir bestudering aan hulle beskikbaar gestel is, is vasgestel dat hulle ontvanklik is vir en positief staan teenoor die benutting van die sistematiese aanrakingseksplorasie. Die ondersoek het ten doel gehad: * Om deur middel van n literatuurstudie die forensiese assesseringstegnieke wat tans in die praktyk benut word, te identifiseer en te bespreek; en * Om die sistematiese aanrakingseksplorasietegniek aan die hand van n literatuurstudie en empiriese navorsing te evalueer. Samevattend kan gestel word dat die tegnieke, soos in hierdie navorsing bespreek, deel behoort uit te maak van die protokol van die professionele persoon wat die seksueel misbruikte kind assesseer. Hierdie navorsing het bevind dat die sistematiese aanrakingseksplorasie n waardevolle forensiese assesseringstegniek is ten opsigte van die seksueel misbruikte kind. / Thesis (M.Sc. (Physiology))--North-West University, Potchefstroom Campus, 2012.
745

A study of subgrid scale modelling and inflow boundary conditions for large eddy simulation of wall-bounded flows

Veloudis, Ioannis January 2006 (has links)
The complicated turbulence structures in wall-bounded flows require accurate subgrid scale, SGS, modelling and realistic inlet boundary conditions for Large Eddy Simulation, LES. The present study focused on the investigation and development of transport equation SGS models and on the development of inlet conditions generation algorithms specialised for LES of wall-bounded flows. The investigation of SGS models has been carried out in two stages. In the first stage, models based on resolved scales and models based on subgrid scales were tested on a series of channel flow cases. Among the second group of models, there was a new SGS model whose development was based on the concept of dissipation calculated from the energy spectrum. The results indicated the superiority of the models based on subgrid scales, with the new model providing the most accurate flow field in general. (Continues...).
746

Moisture Response of Wall Assemblies of Cross-Laminated Timber Construction in Cold Canadian Climates

Lepage, Robert January 2012 (has links)
Wood is a highly versatile renewable material (with carbon sequestering properties), that is light in weight, has good strength properties in both tension and compression while providing good rigidity and toughness, and good insulating properties (relative to typical structural materials). Engineered wood products combine the benefits of wood with engineering knowledge to create optimized structural elements. Cross-laminated timber (CLT), as one such engineered wood product, is an emerging engineering material which provides great opportunities for the building industry. While building with wood has many benefits, there are also some concerns, particularly decay. Should wood be exposed to elevated amounts of moisture, rots and moulds may damage the product or even risk the health of the occupants. As CLT panels are a relatively new engineered wood product, the moisture characteristics have yet to be properly assessed. Consequently, the amount of decay risk for CLT in building applications is unknown, and recommended protective actions during design construction and operation have yet to be determined. The goal of this research was to determine the moisture durability of CLT panels in wall assemblies and address concerns related to built-in construction moisture. The approach used to address the problem was to first determine select moisture properties of CLT panels through experimental approaches, and then use the results to calibrate a hygrothermal model to quantify the risks of wall assemblies. The wall assemblies were simulated in six different cities across Canada, representing a range of climates: Vancouver, B.C., Edmonton, A.B., Winnipeg, M.B., Ottawa, O.N., Québec City, Q.C., and St. John, New-Brunswick. The risks associated with moisture exposure during construction are also considered in the simulations. The experimental phase of the research was limited to moisture uptake tests. These tests were utilized to determine the liquid water absorption coefficient for four different types of full scale panels (2’x2’) and 12 clear wood samples. The panels were either made of 5-ply of Western-SPF, Eastern-SPF, Hemlock-Fir, or 3-ply of a generic softwood provided by a European CLT manufacturer; the clear samples were all cut from the same nominal 2x6 SPF-grade lumber. The panels were installed in a drying rack and gravimetrically tracked to assess the drying rates of the panels. Finite resources precluded more thorough material testing, but a parametric study was conducted to determine the relative impact of the missing material data on the final simulation results. In the hygrothermal simulations, four main wall assembly types were considered- those with either exterior or interior insulation, and those using either vapour permeable or impermeable air-water barriers. Various types of insulation and vapour control were also modelled. The simulations were run for a variety of interior relative humidities. The metric for comparison between the simulations was the water content of a 4mm thin layer on the extreme lamina of a CLT panel system. The results of the simulation suggest that vapour impermeable membranes, when install on dry CLT panels (less than 14% M.C.) do not pose moisture risks in any of the climates considered. However, when high levels of construction moisture is considered, only vapour permeable membranes controlled moisture risks by allowing the CLT panel to dry both to the interior and to the exterior.
747

Dynamics Of Wall Bounded Turbulence

Tugluk, Ozan 01 January 2005 (has links) (PDF)
Karhunen-Lo`{e}ve decomposition is a well established tool, in areas such as signal processing, data compression and low-dimensional modeling. In computational fluid mechanics (CFD) too, KL decomposition can be used to achieve reduced storage requirements, or construction of relatively low-dimensional models. These relatively low-dimensional models, can be used to investigate the dynamics of the flow field in a qualitative manner. Employment of these reduced models is beneficial, as the they can be studied with even stringent computing resources. In addition, these models enable the identification and investigation of interactions between flowlets of different nature (the flow field is decomposed into these flowlets). However, one should not forget that, the reduced models do not necessarily capture the entire dynamics of the original flow, especially in the case of turbulent flows. In the presented study, a KL basis is used to construct reduced models of Navier-Stokes equations in the case of wall-bounded turbulent flow, using Galerkin projection. The resulting nonlinear dynamical systems are then used to investigate the dynamics of transition to turbulence in plane Poiseuille flow in a qualitative fashion. The KL basis used, is extracted from a flow filed obtained from a direct numerical simulation of plane Poiseuille flow.
748

Effects of phytoestrogenic isoflavones on the process of drug transport and metabolism

Lucas, Anthony January 2003 (has links)
This thesis is concerned with phytoestrogenic isoflavones, which are a group of plant-derived compounds that can be consumed in the diet or as over-the-counter preparations for self-medication, and have been associated with a wide range of health benefits. However, unlike the extract of St John's wort and grapefruit juice, little is known about the potential for phytoestrogenic isoflavones to be involved in pharmacokinetic interactions. This thesis describes a series of experiments that investigate that potential by assessing the effects of the isoflavones on intestinal P-glycoprotein-mediated transport, hepatic metabolism, and hepatic cell membrane transport of conventional drugs.
749

An improved low-Reynolds-number k-E [ symbol -dissipation rate]

Chen, Suzhen, Aerospace & Mechanical Engineering, Australian Defence Force Academy, UNSW January 2000 (has links)
[Formulae and special characters can only be approximated here. Please see the pdf version of the Abstract for an accurate reproduction.] Since the damping functions employed by most of the low-Reynolds-number models are related to the non-dimensional distance y+[ special character ??? near-wall non-dimensional distance in y direction], which is based on local wall shear stress, these models become invalid for separated flows, because the wall shear stress is zero at the reattachment point. In addition, the pressure-velocity correlation term is neglected in most of these models, although this term is shown in this thesis to be important in the near-wall region for simple flows and large pressure gradient flows. In this thesis, two main efforts are made to improve the k ??? [special character - dissipation rate] model. First, based on Myong and Kasagi???s (1990) low-Reynolds-number model (hereafter referred to as MK model), a more general damping function [special character - turbulent viscosity damping function in LRN turbulent model] is postulated which only depends on the Reynolds numbers [formula ??? near-wall turbulence Reynolds number]. Second, a form for the pressure-velocity correlation term is postulated based on the Poisson equation for pressure fluctuations. This modified model predicts the turbulent flow over a flat plate very well. It is found that the inclusion of the pressure-velocity correlation term leads to significant improvement of the prediction of near-wall turbulence kinetic energy. When the model is applied to turbulent flow over a backward-facing step, it produces better predictions than the traditional k ??? [special character - dissipation rate] model, FLUENT???s two-layer model and the MK model. Again, the pressure-velocity correlation term improves the turbulence kinetic energy prediction in the separated region over that of other models investigated here. The studies of numerical methods concerning computational domain size and grid spacing reveal that a very large domain size is required for accurate flat plate flow computation. They also show that a fine grid distribution in the near-wall region upstream of the step is necessary for acceptable flow prediction accuracy in the downstream separated region.
750

Transient response analysis for fault detection and pipeline wall condition assessment in field water transmission and distribution pipelines and networks.

Stephens, Mark Leslie January 2008 (has links)
Condition assessment of water distribution pipeline assets has been the focus of water authorities for many years. Transient response analysis, including Inverse Transient Analysis (ITA), provides a new potential method for performing specific nondestructive tests that gives much broader information regarding the condition of pipelines than existing technologies. The basic concept involves inducing a transient in a pipeline and measuring its pressure response. The pressure response is theoretically a function of the condition of the pipeline wall (which is the fundamental characteristic related to the propagation of a transient wavefront) and reflections and damping from any fault that may be present. If an accurate transient model of the pipeline under examination can be developed then it may then be possible to isolate particular parameters in it (relating to the wall thickness of the pipeline or faults such as blockages, air pockets and leaks) and fit these to give optimal matches between the model predicted and measured response of the pipeline. This process is often referred to as inverse analysis (and hence the derivation of the name Inverse Transient Analysis). While a significant amount of numerical and laboratory investigation has been carried out focussing on the use of ITA for leak detection, few field studies have been undertaken. The goal of this research is to determine whether transient response analysis and Inverse Transient Analysis (ITA) can be applied in field situations to provide useful information regarding the condition of pipeline walls and the presence of specific faults such as blockages, air pockets and leaks. Numerous field tests are conducted on large scale transmission pipelines, small scale distribution pipelines and a distribution network in order to obtain a view of the nature of the measured transient responses at each scale and to identify any common characteristics. The capacity of existing transient models to replicate the measured responses is then assessed and they are found to be generally incapable of replicating the field data. Given the physical complexity of field pipelines, and a number of complex phenomena that have been traditionally neglected, this result is not unexpected. The research proposes the development of transient models that can be calibrated to measured responses. These models incorporate mechanisms for including mechanical dispersion and damping and follow precedents developed in other fields of engineering in which damping of transient phenomena is significant. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1325427 / Thesis (Ph.D.) -- University of Adelaide, School of Civil and Environmental Engineering, 2008

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