<p> Laboratory and field measurements were combined with theory in developing models for the various wastewater treatment processes. Some assumptions were made, both in an attempt to simplify the complex mechanisms encountered and to explain known experiences and observations. </p> <p> Models for a primary settling tank, a secondary settling tank, a generalized aerobic biological sludge treatment scheme, an anaerobic digestion system and several other unit processes have been developed. The generalized aerobic biological sludge treatment scheme is an attempt to describe in one physical package, all the various activated sludge process modifications. </p> <p> The executive system used is GEMCS · together with its library of subroutines, such as CONTLl, SEPAOl, JUNCOl and SETSPI, some of which have been modified slightly. </p> <p> The models have been tested on the Drury Lane and the Skyway, Burlington, Sewage Treatment Plants, and have been found to agree very well with plant data. The former has a conventional activated sludge process, whilst the latter employs the extended aeration modification. </p> <p> An inter-active version has been developed, which requires the minimum knowledge of GEMCS for its use. This can be applied as a training and teaching tool for plant operators and students in the field. </p> / Thesis / Master of Engineering (MEngr)

Hydraulic tanks have a variety of different tasks. The have to store the volume of oil needed for asymmetric actors in the system as well as to supply the system with preconditioned oil. This includes the deaeration as air contamination is affecting the overall system performance. The separation of the air in the tank is being realized mainly by passive methods, improving the guidance of the air and oil flow. The use of CFD models to improve the design of hydraulic tank is recently often discussed. In this paper, a design method for hydraulic tanks using CFD is presented and discussed. First the different requirements on a hydraulic tank are described as well as the motivation changing the tank designs. Additionally, a quick overview on different calculation models for the behavior of air in oil as well as the capabilities of CFD to reproduce them is given. After this the methodology of tank design applying CFD is presented. The method is then used in an example.

This thesis, through examination of the battles of Kadesh (1288 B.C.), Alam Halfa (1942), and the Arab-Israeli War (1967), attempts to determine the degree of similarity between tactical employment of the ancient chariot and modern armored vehicles. Sources include official analysis and records of participants and observers. This thesis proves that tactical employment of chariots and modern armored vehicles is clearly similar. Chariots were used to support infantry in the three conflicts examined. Also proved is that chariots were used almost identically with armored vehicles in exploiting a breakthrough, serving as reaction forces, making a reconnaissance, conducting retrograde operations, and holding or blocking enemy forces.

This thesis analyses the emergence and evolution of the think-tanks in Turkey. It seeks primarily to answer to whether or not it is possible to mention &lsquo / a think-tank culture&rsquo / in Turkey. After the definition, characteristics and types of the think-tank term are debated, the historical background of think-tanks all over the world is analyzed. The thesis looks at similarities and differences among the think-tanks in and outside Turkey in terms of their size and areas of specialization. It also tries to find out who are pioneering to the establishment of think-tanks, whom the think-tanks are serving, which financial resources and functions they have in Turkey.

This thesis is performed to evaluate the design consideration and performance characteristics of a surge tank for a diaphragm pump operation and to evaluate the proper volume and inlet area of surge tank in order to reduce the pulsations of the discharge pressure. An experimental set up is constructed for a three diaphragm positive displacement pump and the experiments are conducted afterwards. The surge tanks having different volumes and the surge tank inlet area configurations are tested in order to achieve the minimum peak to peak pulsations. Experiments showed that among the different sizes of the surge tanks, the minimum peak to peak pulsations are achieved with the largest volume which is the original surge tank of the test pump used by the pump manufacturer. This result is supported by the literature which states that with greater surge tank size the magnitude of pulsations can be diminished more. Regarding the surge tank inlet area design / among the eight different adaptors a proper inlet area value is concluded having the minimum peak to peak pulsations also smaller than the original configuration.

In order to enhance the performance of a large horizontal thermal energy storage, a numerical model was generated and validated using measurements obtained from Drake Landing Solar Community (DLSC). A total of nine different baffle configurations were tested in order to enhance the thermal stratification. The designs were tested for a total of six different cases of charging, discharging and simultaneous charging and discharging in an attempt to better identify key features that mix the tank under realistic conditions. Characterization of the tank performance was done by monitoring the tank outlet temperature and computing Huhn's efficiency Second Law characterization index). Results show that the current tanks at DLSC experience excessive mixing due to plume entrainment that occurs during the spreading of the inlet jet. The introduction of a baffle into the middle of the tank was found to have no impact on the level of stratification. In addition, most designs tested have a relatively high level of stratification during charging, discharging and simultaneous charging and discharging, but fail to sustain the level of stratification when a positive buoyant jet is introduced. It was demonstrated that the inlets and outlets should be moved to the top and bottom of the tank to eliminate stagnant fluid that is not easily discharged. Horizontal baffles are effective in allowing the inlet jet to spread horizontally but not vertically, thus reducing the mixing. Alternatively, a simple solution would be to increase the size of the inlet, which has a comparable performance to the best baffle configurations. / Thesis / Master of Applied Science (MASc)

The development, testing, and use of liquid propellant and hybrid rocket propulsion systems for spacecraft and their launch vehicles routinely involves the use of cryogenic propellants. These propellants provide high energy densities that enable high propulsive efficiency and high engine thrust to vehicle weight ratios. However, use of cryogenic propellants also introduces technical problems not associated with other types of propellants. One of the major technical problems is the phenomenon of propellant tank pressurant and ullage gas collapse. This collapse is mainly caused by heat transfer from most of the ullage gas to tank walls and interfacing propellant, which are both at temperatures well below those of this gas. Pressurant gas is supplied into cryogenic propellant tanks in order to initially pressurize these tanks and then to maintain required pressures as propellant is expelled from these tanks. The cryogenic propellants expelled from the tanks feed rocket engine assemblies, subassemblies, and components at required interface pressures and mass flow rates. The net effect of pressurant and ullage gas collapse is increased total mass and mass flow rate requirements of pressurant gases. For flight vehicles this leads to significant and undesirable weight penalties. For rocket engine component and subassembly ground test facilities this results in high construction and operational cost impacts. Accurate predictions of pressurant gas mass transfer and flow rate requirements are essential to the proper design of systems used to supply these gases to cryogenic propellant tanks. While much work has been done in the past for predicting these gas requirements at low subcritical tank pressures, very little has been done at supercritical tank pressure conditions and there are selected cases where errors of analytical predictions are high. The objectives of this study are to develop a new generalized and improved computer program to determine pressurant gas requirements at both subcritical and supercritical tank pressure conditions, and then evaluate and validate the consistent accuracy of this program over a wide range of conditions by comparison of program results to empirical data.

Deltastream is an on-going project carried by Tidal Energy Limited since almost twenty years. It is a tidal energy converter with a triangular shape and one turbine on each tower. It has gone through many evolutions of design but a first prototype will be installed in the end of 2014 at Ramsey Sound. The deployment and recovery operations will be carried out with a single lift point through a heavy lift frame. Two issues have to be tackled during the operation: the rate of flooding of the ballasts and the tension on the lift crane cable. The most favourable sea state must be found in order to minimise the crane cable tension as well as the best inlets and outlets configuration for the ballasts system. In order to tackle those issues, preliminary analytical work was conducted on the demonstrator to assess the stability during the flooding process. A scaled model was designed and built in order to be tested in a wave-towing tank. The results from the tests highlight that the deployment and the recovery operations are safe for both the barge and Deltastream for the range of wave conditions tested in the tank. However, the sea state has an important impact on the proceeding of the operations, especially the period of the waves.

In the screening and concept selection stages of gas storage projects, many estimates are required to value competing projects and development concepts. These estimates are important because they influence which projects are selected and which concept proceeds into detailed engineering. In most cases, there is uncertainty in all of the estimates. As a result, operators are faced with the complex problem of determining the optimal design. A systematic uncertainty analysis can help operators solve this problem and make better decisions. Ideally, the uncertainty analysis is comprehensive and includes all uncertain variables, and simultaneously accounts for reservoir behavior, facility options, and economic objectives. This thesis proposes and demonstrates a workflow and an integrated optimization model for uncertainty analysis in gas storage. The optimization model is fast-solving and eliminates most constraints on the scope of the uncertainty analysis. Using this or similar workflows and models should facilitate analysis and communication of results within the project team and with other stakeholders. / text

This dissertation looks into the processes by which neoliberalism is mutating with various local and global discourses in order to transform urban space for marginalized street hawkers in the Global South, specifically Delhi, India. Following the current engagements in geographic literature on neoliberalism that focus on the contextually embedded character and the path-dependent process of the spread of free market ideas, I make free market advocacy think tanks--a rather unknown and under-investigated accomplice to this process--my main entry point. Corporate funded think tanks are often found advocating a neoliberal doctrine of free markets, minimal government intervention, and privatization. A self-professed civil society organization, the Center for Civil Society (CCS) in Delhi is one of the first neoliberal, national and foreign corporation funded, advocacy think tanks in India and one of its many agendas is to counter the popular belief that neoliberalism is harmful for the urban poor such as street hawkers. Various NGOs, social workers, scholars, academicians, and think tanks including CCS came together to form the National Policy of Street Vendors, 2009 (NPSV), one of the first policy proposals in modern India to tackle the problems of urban spaces of street vending. Through my investigations I wish to highlight the neoliberal attitudes that are concealed in this policy regarding street hawkers. By bringing these neoliberal undertones to the forefront, this dissertation discusses how this so called “pro-hawking” policy that is being pushed to be implemented in the majority of Indian cities is in fact hostile to hawkers. I demonstrate this fact by explaining that NPSV and its proponents view space as a capitalist commodity and are attempting to transform the rich social spaces of Indian city streets into hollow container spaces of capitalist production and consumption. In this way, this dissertation connects macro spaces of governance such as city streets to the micro spaces of governmentality such as think tanks like CCS.