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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.
151

An Empirical Study of the Causes and Consequences of Mergers in the Canadian Cable Television Industry

BYRNE, DAVID P R 13 December 2010 (has links)
This dissertation consists of three essays that study mergers and consolidation in the Canadian cable television industry. The first essay provides a historical overview of regulatory and technical change in the industry, and presents the dataset that I constructed for this study. The basic pattern of interest in the data is regional consolidation, where dominant cable companies grow over time by acquiring the cablesystems of small cable operators. I perform a reduced-form empirical analysis that formally studies the determinants of mergers, and the effect that acquisitions have on cable bundles offered to consumers. The remaining essays develop and estimate structural econometric models to further study the determinants and welfare consequences of mergers in the industry. The second essay estimates an empirical analogue of the Farrell and Scotchmer (1988) coalition- formation game. I use the estimated model to measure the equilibrium impact that economies of scale and agglomeration has on firms’ acquisition incentives. I also study the impact entry and merger subsidies have on consolidation and long-run market structure. The final chapter estimates a variant of the Rochet and Stole (2002) model of multi-product monopoly with endogenous quality and prices. Using the estimated model I compute the impact mergers have on welfare. I find that both consumer and producer surplus rise with acquisitions. I also show that accounting for changes both in prices and products (i.e., cable bundle quality) is important for measuring the welfare impact of mergers. / Thesis (Ph.D, Economics) -- Queen's University, 2010-12-09 14:39:15.431
152

Use of the Confined Impinging Jet Reactor for production of nanoscale Iron Oxide particles

Siddiqui, Shad Waheed Unknown Date
No description available.
153

The geographical economy of South Africa / W.F. Krugell

Krugell, Willem Frederik January 2005 (has links)
This study examines the determinants of economic growth at sub-national level in South Africa, and investigates cross-locality medium-term (five-year) growth rate differentials between 354 magisterial districts. The period in question is 1998 to 2002. A dynamic panel data regression model is used that includes measures of geography (distance and natural resources) as well as recent estimates of physical and human capital. It is found that the significant determinants of local economic growth are distance from internal markets, human capital, export propensity, and the capital stock of municipalities (reflecting institutional quality and governance on local government level). Distance from international harbours, as a measure of transport costs, and urban agglomeration (or density) affects growth indirectly through its significant effect on the ability of a region to export. Overall, these results indicate that geography is important for economic growth, independent of its effects in institutions. Bearing in mind the medium-term focus of the work, no evidence of absolute convergence could be found over a five-year period, rather the tentative evidence suggests slow beta convergence. / Thesis (Ph.D. (Economics))--North-West University, Potchefstroom Campus, 2005.
154

Nonlinear optical characterisation of organic chromophores and aspects of molecular aggregation

Hackman, Nancy-Ann January 2001 (has links)
The work presented in this thesis describes an investigation into the properties and behaviour of a new class of nonlinear optical organic chromophores. This study contributes to the optimisation of nonlinear optical molecules through an improved understanding of the relationships between the molecular nonlinear optical properties and the measured macroscopic quantities. A series of highly dipolar non-linear optical chromophores with absorption typically in the range of 350-500 nm have been synthesised by the reactions of amines with tetracyanoquinodimethane (TCNQ). One of the advantages of these materials is the large molecular figure of merit (μβ where μ is the molecular dipole moment and P is the second order polarisability), which theoretically allows large nonlinear optical coefficients to be obtained. The molecular dipole moments of these chromophores were determined both experimentally and theoretically, and were found to agree. The nonlinear optical properties of these compounds in solution were studied using an electric field induced second harmonic generation (EFISH) technique. The measurements of μβ at 1064 nm and 1907 nm in chloroform and acetone are presented. Moderate μβ values were obtained but β is found to be unexpectedly small in chloroform and shows unusual dispersion characteristics in this solvent compared to acetone. Further concentration investigations revealed features that suggest the presence of aggregates within solution. Optical spectroscopy measurements provide evidence of new species whose presence and conformation were found to be solvent-dependent. The results of this work highlight the need for an entire concentration range to be studied if accurate determination of molecular properties of highly dipolar molecules is required. Guest-host polymer films of these materials have been corona poled using a constant current corona triode. Detailed characterisation studies of the second order nonlinearities using second harmonic generation (SHG) were compared to a less dipolar molecule. These investigations showed that the highly dipolar TCNQ derivatives show severe aggregation within the polymer films. The magnitude of the SHG that can be obtained from such systems is therefore limited by this aggregation.
155

Attraction and repulsion : modelling interfirm interactions in geographical space

Protsiv, Sergiy January 2012 (has links)
More than three quarters of the world’s economic activity is concentrated in cities. But what drives people and firms to agglomerate in urban areas? Clearly, some places may offer inherent benefits due to the location itself, such as a mild climate or the presence of natural harbours, but that does not tell the whole story. Rather urban areas also offer spaces for interaction among people and firms as well as the proximity to potential partners, customers, and competitors, which could have a significant impact on the appeal of a location for a firm. Using multiple novel methods based on a unique detailed geographical dataset, this dissertation explores how a location’s attractiveness is impacted by the presence of nearby firms in three studies. The first study explores the influence of the density of economic activity on wages at a given location and attempts to disentangle the separate mechanisms that could be at work. The second study is concerned with the locations of foreign-owned firms and more specifically whether foreign-owned firms are more influenced by agglomeration benefits than domestic firms. The final study switches from modelling the effects of location to modelling the location patterns themselves using economic theory-based spatial point processes. The results of these studies make significant contributions to empirical research both in economic geography and international business as a set of theoretical propositions are tested on a very detailed dataset using an advanced methodology. The results could also be of interest for practitioners as the importance of location decisions is further reinforced, as well as for policymakers as the analyses explore not only the benefits but also the detriments of agglomeration. Sergiy Protsiv is a researcher at the Center for Strategy and Competitiveness at the Stockholm School of Economics. He participated in several projects on clusters and regional development, most notably the European Cluster Observatory. / <p>Diss. Stockholm : Handelshögskolan, 2012</p>
156

Improved Desiccant Coatings for Heat and Water Vapour Transfer on the Matrix Surfaces of Air-To-Air Regenerative Wheels

2012 July 1900 (has links)
Air-to-air energy recovery wheels are now widely used in industry and buildings; however, the effectiveness of water vapor exchange in these regenerative wheels appears to be much lower than may be economically feasible. The purpose of this research is to investigate the feasibility of using agglomerated desiccant particle coatings to improve the performance of regenerative wheels used in HVAC air-to-air heat and moisture exchange and energy recovery applications. Desiccant particles coated on wheels lose most of their water vapor sorption capacity due to the method of coating. Desiccant agglomerates can be made by mixing starch, fine silica gel particulate, and water within an agglomerating device. The desiccant particle agglomerating process improves the desiccant mass transfer properties by increasing the overall surface area of desiccant particles; and also by creating a much rougher surface that can increase the likelihood of turbulent flow, and therefore, increasing the overall mass transfer rates. The industrial desiccant coating process involves submerging the desiccant into a coating agent and then applying this mix to the substrate or the matrix of the energy wheel. This process was improved in this research by ensuring the particles are applied after the coating agent is applied to ensure that the agglomerates or desiccant particles are not submerged by the coating material. Because testing energy wheels under steady state operating conditions has proved to be difficult, time consuming and costly in the past, a small parallel flow test cell is used to measure the transient response of coated substrate aluminum sheets after a step change in the inlet air humidity or temperature. Using a previously developed theoretical model, the time constants for these inlet step change responses are then used to predict the sensible and latent effectiveness of a regenerative energy wheel coated with the same agglomerated particles, which is rotated at a known operating speed and wheel face velocity. When the new desiccant coatings are used, it is shown that the latent heat effectiveness for a typical wheel could be up to 85%. It is found that the steady state air flow pressure drop readings for the test cell shows that agglomerated particles coated on the surfaces within the test cell implies some transitional turbulent flow behavior compared to similar substrate surfaces coated in a conventional manner with desiccant particles (e.g. up to 60% higher pressure drop at a channel Reynolds number of 300) in the same test cell. This implied enhanced turbulence flow friction factor in the test cell suggests a somewhat similar enhancement for increased mass and heat transfer coefficients for the test cell or coated wheel matrices. The transient results for humidity step changes for air flow through the test cell reveals that the adsorption and desorption response time constants are much larger for the agglomerated coated substrate surfaces than the conventional industrial coated surfaces. These data imply much higher moisture or latent heat effectiveness values for wheels coated with agglomerated particles. When the new desiccant coatings are used, it is shown that the latent heat effectiveness for a typical wheel could be better than 80% or 20% higher than currently available typical energy wheels. With improvements to the desiccant particle agglomerating process, desiccant coating process and particle coating and testing methods, this thesis shows that significant improvements may be practical for the design, testing and operation of regenerative heat and moisture exchange wheels.
157

Use of the Confined Impinging Jet Reactor for production of nanoscale Iron Oxide particles

Siddiqui, Shad Waheed 11 1900 (has links)
The confined impinging jet reactor gives efficient mixing performance as required for fast reactions. In this work the mixing performance of CIJR is characterized through three measures: estimates of the energy dissipation, micromixing efficiency based on the yield of a homogeneous (iodide-iodate) reaction and particle size resulting from a heterogeneous (iron oxide) precipitation reaction. Whereas product yield and energy dissipation are used to test operational robustness of CIJR, iron oxide model system is used to study the effect of feed flow rate (mixing) and reactant concentration on precipitate agglomerate size. Mixing and concentration effects on nucleation, particle growth and particle agglomeration are tracked to understand the agglomeration process. Various types of stabilizers and additive concentrations to limit particle agglomeration are also tested. Effects of in situ and post-reaction sonication on agglomerate size are also investigated. Efforts are made to determine variations in mixing efficiency the operational robustness of the scale-up (2X and 4X) geometries. Also efforts are made to identify scaling parameters and the limit on geometric scale-up for good mixing performance. Energy dissipation is found to vary between 20 W/kg and 6800 W/kg in CIJR and decreases on scale-up at constant Reynolds number. The operation of the CIJR and the scale-up geometries is robust to changes in flow rate, exhibiting stable performance up to 30% difference in inlet flow rates. Reliable mixing performance is obtained until 2X scale-up, while at low flow rates, the jets fail to impinge in 4X scale-up, and sometimes failing to fill the reactor volume. Iron oxide primary and agglomerate particles are seen to vary with flow rate and reactant concentrations. Largest primary particles (and smallest agglomerates) are obtained at high flow rates and high reactant concentrations, which indicate to size dependent agglomerative tendency of the primary particles. Stabilizers added in situ see limited success. Post-reaction sonication is helpful in dispersing soft agglomerates, but in situ sonication shows no significant reduction in agglomerate size with or without stabilizer. Primary particles are understood to agglomerate due to collisions induced by Brownian motion, simple shear and velocity fluctuations in turbulent flows. These collision mechanisms operate at different length scales in the fluid mass. / Chemical Engineering
158

台北國際電腦展參展廠商認知成功因素與網絡關係之研究 / Computex Taipei exhibitors success factors for cognitive and the study of the relationship with the network

蔡明延 Unknown Date (has links)
展覽產業為各產業間爲推廣產品所新興的行銷模式,此方式可減少廠商間交易成本,建立互信合作之交易型態,亦可帶來可觀商機並帶動相關產業發展,增加就業機會,創造國家直接及間接經濟效益,將有助於提升城市國際知名度及國家競爭力。 我國所舉辦之國際展覽以台北國際電腦展最為出色,僅次於德國為全球第二大之專業電腦展。因此,如何坐穩全球第二的寶座,甚至超越德國成為全球最大國際電腦展,即成為展覽產業之重大課題。有鑑於此,台北國際電腦展的成功之處為何?參展廠商所關心的課題又為何?如何在激烈的國際展覽產業的競爭環境中脫穎而出,便成為本文研究所關心的重點。而展覽期間全球各地業者短暫聚集於此,產生地方互動與全球連結的作用,如何讓參展廠商與購買者在展後繼續維持與發展,將有賴於網絡關係的形成,此種短暫聚集的現象,對於廠商及購買者有何益處,是否有助於各廠商與競爭者或購買者建立合作關係,促成網絡的連結,此一問題便成為本文另一關注的焦點。 研究結果顯示,參展廠商認為電腦展的成功與否在於參展廠商能否在電腦展拓展新客戶並銷售產品,以增進公司訂單及銷售金額,而參展績效的好壞將是廠商是否繼續參展的重要指標,更是影響電腦展的成功因素。廠商藉由電腦展短暫聚集,於短時間內接觸世界各大買家,藉此拓展行銷網絡,達到銷售目的,進而增加公司營運績效,並擴大生產鏈,增加規模經濟效益。
159

A discretized population balance for simultaneous nucleation, growth and aggregation / by Michael John Hounslow

Hounslow, Michael John January 1990 (has links)
Bibliography: leaves 228-237 / xii, 287 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Chemical Engineering, 1990
160

Raumpolitische Diskurse um Metropolregionen : eine Spurensuche im Verdichtungsraum Rhein-Ruhr /

Schmitt, Peter. January 2007 (has links)
Zugl.: Dortmund, Universiẗat, Diss.

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