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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.
181

Drop size distribution and interfacial area in reactive liquid-liquid dispersion

Rajapakse, Achula, s9508428@student.rmit.edu.au January 2007 (has links)
Emulsion explosives have become the preferred choice as blasting agents for numerous industries including mining, agriculture, and construction. One of the most important components in such an emulsion is an emulsifier, which controls the emulsification properties of the explosive. The present study involves the production of one such emulsifier, which is produced by reacting two immiscible liquids, PIBSA (polyisobutylene succinic anhydride) and MEA (monoethanolamine). The study examines the effect of design variable such as the impeller speed, impeller type and the dispersed phase volume fraction on interfacial area. Experiments were carried out in a 0.15 m diameter fully baffled stirred tank using a 6-bladed Rushton turbine impeller and a marine propeller. Drop size was determined using a microscope with a video camera and image processing system. The transient concentration of PIBSA was determined using FTIR analysis and used to estimate the volume fraction of the dispersed phase (ƒÖ). The effective interfacial area was calculated using the Sauter mean drop diameter, d32 and ƒÖ. Impeller speeds ranging from 150 to 600 rpm and dispersed phase volume fractions, ƒÖ ranging from 0.01 to 0.028 were examined in the experimental study. It was found that that the evolution of Sauter mean drop diameter, d32 has four different trends depending on ƒÖ and impeller speed. At high impeller speeds and high ƒÖ, d32 values decrease initially and reach constant values after a long period of time. This trend is consistent with the findings in previous investigations. Under certain operating conditions, d32 values increase initially with stirring time to reach a maximum value and then decrease to reach a steady state value. The presence of these trends has been attributed to the effect of changing physical properties of the system as a result of chemical reaction. Results indicate that, in general, Sauter mean drop diameter d32 decreases with an increase in agitation intensity. However a decrease in the dispersed phase volume fraction is found to increase d32. These trends are found to be the same for both impeller types studied. Comparing the drop size results produced by the two impellers, it appears that low-power number propeller produces s ignificantly smaller drops than the Rushton turbine. It was found that the concentrations of reactants decrease with time for all impeller speeds thereby leading to a decrease in interfacial area with the progress of the reaction. Interfacial area values obtained at higher impeller speeds are found to be lower in spite of lower d32 values at these speeds. Also, these values decrease with time and become zero in a shorter duration indicating the rapid depletion of MEA. The interfacial area values obtained with the propeller at a given impeller speed are lower as compared to those for Rushton turbine. They also decrease and become zero in a shorter duration as compared to those for Rushton turbine suggesting propeller¡¦s performance is better in enhancing the reaction rate.
182

The Role Scenarios of EU in the World of 2020 : a Comparative Perspective Between European and US based Think Tanks.

Ahmed, Hameed, Xiaohong, Ye January 2005 (has links)
<p>This paper aims to tell out a “what next” question of the future scenarios that the European Union (EU), as a security community, is most likely to face in its development as a world power up to the year 2020. The EU is a rapidly evolving concept consolidating with comprehensive internal and external dimension and implication. Key concepts such as power, security, global governance and international order have been used as the underlying themes that will determine the course of the future. In this context Neo-realism, Constructivism and Security Community’s model have been used as the theoretical framework to examine how EU’s role in the international system can be analyzed in the conceptual framework of security. This is followed by a discussion on the concurrent ESDP instruments initiated by the new Constitution as a key momentum of security community buildup internally. To broaden understanding and to get a variety of perspectives, research reports and policy papers of some transatlantic think tanks were analyzed. While multi- perspectives of some prominent think tanks were reviewed, analyzed and discussed, the opinions of policy makers at the United Nations Head Quarters, New York, were also explored to reflect on how EU’s role in international affairs is being perceived in the corridors of power, both concurrently and futuristically. These views were consequently augmented by attending General Assembly and Security Council sessions during September 2004 to January 2005 to observe what sorts of power and influence EU exerts in the contemporary international system and what potential it has for the future. Based on these findings, the paper identified three scenarios that EU is most likely to face in its efforts to be an international power. The paper concluded with the understanding that EU has vision and potential to be a power in the international system futuristically, which can be further enhanced if EU enhances its military capabilities and improves its power perception in the eyes of various stakeholders. However since the international system is volatile, its future role cannot be predicted with accuracy, only alternative options can be identified. EU’s roles are dependent upon the degree of success of the integration process internally and the structural interaction with other major actors in the international system. Whereas EU may enhance its role up to the year 2020, it may not enter into a power conflict with other major powers. However it will play its role comparable with the magnitude of its size, power and influence to manage the international system, futuristically in an improvised way.</p>
183

Assessment of public awareness of septic systems in rural Benton County

Gillett, Christopher S. 29 July 1998 (has links)
Graduation date: 1999
184

The Role Scenarios of EU in the World of 2020 : a Comparative Perspective Between European and US based Think Tanks.

Ahmed, Hameed, Xiaohong, Ye January 2005 (has links)
This paper aims to tell out a “what next” question of the future scenarios that the European Union (EU), as a security community, is most likely to face in its development as a world power up to the year 2020. The EU is a rapidly evolving concept consolidating with comprehensive internal and external dimension and implication. Key concepts such as power, security, global governance and international order have been used as the underlying themes that will determine the course of the future. In this context Neo-realism, Constructivism and Security Community’s model have been used as the theoretical framework to examine how EU’s role in the international system can be analyzed in the conceptual framework of security. This is followed by a discussion on the concurrent ESDP instruments initiated by the new Constitution as a key momentum of security community buildup internally. To broaden understanding and to get a variety of perspectives, research reports and policy papers of some transatlantic think tanks were analyzed. While multi- perspectives of some prominent think tanks were reviewed, analyzed and discussed, the opinions of policy makers at the United Nations Head Quarters, New York, were also explored to reflect on how EU’s role in international affairs is being perceived in the corridors of power, both concurrently and futuristically. These views were consequently augmented by attending General Assembly and Security Council sessions during September 2004 to January 2005 to observe what sorts of power and influence EU exerts in the contemporary international system and what potential it has for the future. Based on these findings, the paper identified three scenarios that EU is most likely to face in its efforts to be an international power. The paper concluded with the understanding that EU has vision and potential to be a power in the international system futuristically, which can be further enhanced if EU enhances its military capabilities and improves its power perception in the eyes of various stakeholders. However since the international system is volatile, its future role cannot be predicted with accuracy, only alternative options can be identified. EU’s roles are dependent upon the degree of success of the integration process internally and the structural interaction with other major actors in the international system. Whereas EU may enhance its role up to the year 2020, it may not enter into a power conflict with other major powers. However it will play its role comparable with the magnitude of its size, power and influence to manage the international system, futuristically in an improvised way.
185

Detection of Surface Corrosion by Ultrasonic Backscattering

Retaureau, Ghislain J. 22 May 2006 (has links)
Corrosion often occurs in the inner aluminum lining of the HB-53 helicopter external fuel tank, resulting in fuel leaks. This project centers on developing an in-situ ultrasonic inspection technique to detect corroded areas inside the fuel tank. Due to the complexity of the composite structure of the tank, the ultrasonic inspection is carried out from inside the tank using a monostatic backscattering technique. The backscattered field contains information related to the insonified surface properties (surface roughness scales). Numerical predictions are implemented with a simplified model of backscattered intensity (Ogilvy, 1991). Experimental results are obtained on artificially corroded plates, and on the actual fuel tank of the HB-53 helicopter. Signal processing techniques (Envelope Correlation and Inverse Technique) are used to detect corroded surfaces with data obtained with a focused 10 MHz pulsed transducer.
186

Compulsory Insurance and Compensation for Bunker Oil Pollution Damage /

Zhu, Ling. January 2006 (has links)
Univ., Diss.--Hamburg, 2006. / Literaturverz. S. [215] - 225.
187

Experimental in-plane behavior of a generic scale model drag embedment anchor in Kaolinite test beds

McCarthy, Katelyn Barbara 07 July 2011 (has links)
The trajectory and capacity are key components of the design of drag embedment anchor and drag-in vertically loaded anchors. This experimental testing program quantifies two factors that describe the anchor trajectory and capacity: the equilibrium bearing factor (Ne) and the tangential bearing factor (Ne). These factors can aid in the development of a numerical model of anchor behavior. A magnetometer device is used to track the orientation and location of the anchor during drag embedment. The results of the experimental testing program were compared with the results from a predictive model. The experimental program consisted of drag embedment tests with various testing conditions including different anchor line diameters and different initial pitch orientations. The results with the different anchor lines indicated that thinner anchor lines cause the anchor to dive deeper in the soil. The different initial pitch results indicate that regardless of the initial pitch of the anchor, the anchor rotates to a unique pitch trajectory within 2 fluke lengths. / text
188

Installation, commissioning and preliminary microbiological and operational investigations of full-scale septic tank digestion of sewage.

Taylor, Michelle Anne. January 1997 (has links)
This study investigated the commissioning and maintenance of a Pennells two-tank bioreactor system with specific reference to its application in rural areas of KwaZulu- Natal, South Africa to treat sewage and generate biogas. The septic tank configuration was installed in a community which lacked electricity and domestic waste disposal. An artificial wetland was constructed at the outlet of the system to facilitate further treatment. Inefficient operation and maintenance of the system occurred due to various social/community-related problems which are typical of a field- and community-based project of this nature in a rural region of a Third World African country. These problems affected both maintenance and digester performance. The Pennells system was characterized by incomplete anaerobiosis which limited methanogenesis. Despite this, and attendant problems of low temperatures and elevated pH values, COD removal resulted. Laboratory-scale batch cultures, in conjunction with fluorescence and scanning electron microscopy, were used to identify a suitable anaerobic digester sludge for inoculation purposes. Perturbation experiments with locally used detergents and toxic compounds demonstrated the inimical effects of these agents. In contrast, low concentrations of penicillin and tetracycline promoted methanogenesis. Further analysis with light, fluorescence and scanning electron microscopy identified the acidogens as the predominant bacterial species, whilst fluorescence microscopy confirmed the absence of methanogens in the bioreactor. / Thesis (M.Sc)-University of Natal, Pietermaritzburg, 1997.
189

Developing an integrated concept for sewage sludge treatment and disposal from municipal wastewater treatment systems in (peri-)urban areas in Vietnam / Entwicklung eines ganzheitlichen Konzeptes zur Behandlung und Entsorgung von Klärschlamm aus kommunalen Abwasserbehandlungsanlagen in (peri-)urbanen Gebieten Vietnams

Karius, Ralf 23 August 2011 (has links) (PDF)
The study took place in Vietnam at Hanoi University of Science in the framework of the DAAD (German Academic Exchange Service) – “An advancement of the German-Vietnamese University partnerships”. The research has been supported by the program: “Wastewater and Solid Waste Management in Provincial Centers” and belongs to its technical component. The present diploma thesis elaborates the current situation of sewage sludge management in Vietnam and is dealing with sludge characteristics from both domestic sewage treatment facilities and septic tanks. During the research, different treatment components and treatment facilities have been analyzed to carry out a comprehensive survey of sewage sludge types. In this thesis, a guideline (draft) was developed as a main result, which can be helpful to bridge the legislative gap for sewage sludge re-use in Vietnam. In conclusion, an integrated concept has been developed, which recommends the application of selected proceeding elements to treat sewage sludge and the further utilization of re-useable materials in agriculture in a controlled and environmentally-safe manner. / Die Diplomarbeit wurde im Rahmen des Deutsch-Vietnamesischem Auslandsaustauschprogramms an der „Hanoi University of Science“ verfasst. Dieses Vorhaben wurde unterstützt von dem DAAD (Deutschen Akademischen Austausch Dienst), und ist im technischem Bereich des Programms “Wastewater and Solid Waste Management in Provincial Centers“ einzugliedern. Die vorstehende Diplomarbeit beschäftigt sich mit dem aktuellen Klärschlammmanagement in Vietnam und liefert dabei detaillierte Resultate zu verschiedenen Klarschlammtypen aus kommunalen Abwasserbehandlungsanlagen. Bei den Untersuchungen wurden verschiedene Abwasser- und Klärschlammbehandlungsanlagen untersucht, um einen Überblick zu den gebräuchlichen Behandlungsmethoden in Vietnam zu erarbeiten. Zusätzlich wurden die institutionellen und rechtlichen Rahmenbedingungen überprüft. Der Entwurf einer Verordnung zur Verwertung von Klärschlamm in der Landwirtschaft wurde vorgelegt, um eine bestehende rechtliche Lücke in Vietnam zu schließen. Mit dieser Arbeit wurde ein integriertes Konzept entwickelt, welches mittels verschiedene verfahrenstechnische Elemente den Klärschlamm behandelt und darauffolgend das verwertbare Material in ausgewählten landwirtschaftlichen Flächen in einer kontrollierten und umweltschonenden Weise verwertet.
190

Intellectuals in the Australian Press

Murray, Craig January 2005 (has links)
The notion of the 'public intellectual' has been a recurring discussion topic within sociology and the humanities for decades. Yet it has been largely neglected within media and cultural studies. Accordingly, few scholars have discussed in much depth how public intellectuals operate within the media and what functions this media role may facilitate. Intellectuals in the Australian Press is an exploration into this generally overlooked area of scholarship. It aims to provide three levels of insight into the topic. Firstly, the study looks closely at the appearance and the function of public intellectuals in the Australian press. It outlines how public intellectuals contribute to the newspapers and how newspapers contribute to Australian public intellectual life. Secondly, the thesis outlines and examines in detail three types of public intellectual in Australia. Specifically, it examines the journalist, the academic and the think tank researcher as types of intellectual who write regularly for Australia's newspapers. Thirdly, Intellectuals in the Australian Press delivers detailed intellectual biographies of three of Australia's most prominent press intellectuals, each of whom exemplifies one of these three categories. These commentators are The Australian's Paul Kelly, The Age's Robert Manne, and the Sydney Morning Herald's Gerard Henderson.

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