Master of Science / Department of Mechanical and Nuclear Engineering / Steven Eckels / Both cavitating and flashing flows are important phenomena in fluid flow. Cavitating flow, a common consideration in valves, orifices, and metering devices, is also a concern in loss of coolant accidents for liquid water in power plants when saturation pressures are below atmospheric pressure. Flashing flow is a common consideration for devices such as relief and expansion valves and fluid injectors as well as for loss of coolant accidents in which the coolant’s saturation pressure is above atmospheric. Of the two phenomena, flashing flow has received greater interest due to its applicability to safety concerns, though cavitating flow is perhaps of greater interest in terms of energy efficiency. It is possible for cavitating and flashing flow to actually become sonic. That is, the local velocity of a fluid can exceed the local speed of sound due to the unique properties of two-phase mixtures. When a flow becomes sonic, it is possible for the flow to accelerate and impose additional energy losses that would not otherwise occur. Models of this aspect of two-phase flow are not well developed, typically only being presented for the case of constant area ducts. In this paper two models for cavitating sonic flow are developed and described by applying the integral forms of the mass, momentum, and energy equations to a control volume of variable cross-sectional area. These models, based on the homogeneous equilibrium model (HEM) and separated flow model, are then applied to experimental data taken by the author with R-134a as the fluid of interest. Experimental data were taken with four instrumented converging-diverging nozzles of various geometries using a custom testing rig that allowed for precise control and measurement of flow parameters such as mass flow, temperature, and pressure. The resultant data from the models are then examined, focusing on the resultant velocities, Mach numbers, quality, and shear stresses.

Cette thèse a pour objectif d‟étudier les déséquilibres globaux avec un modèle multinational empirique en stock-flux cohérent. La dernière crise financière de 2008, qui a été suivie par une crise économique mondiale, a reconfiguré l‟évolution de nombreuses variables macroéconomiques. Les déséquilibres globaux se sont fortement résorbés et le maintien de cet ajustement résulte essentiellement de facteurs macroéconomiques conjoncturels, en raison de l‟effondrement de la demande. Compte tenu des changements majeurs durant ces dernières années, nous examinons dans notre recherche les perspectives de croissance future aux États-Unis, en Chine et en Europe dans le cas des poursuites des politiques économiques actuelles, à l‟horizon 2030. Pour cela, nous utilisons d‟abord le modèle C.A.M développé par F. Cripps, ensuite nous estimons notre propre modèle multinational à cinq régions. L‟analyse se focalise sur l‟évolution des déséquilibres globaux, la croissance économique et le taux de change. Les projections du scénario de base de notre modèle multinational, dans le cas de la poursuite des politiques actuelles, montrent que l‟ajustement des déséquilibres externes est maintenu au prix de déséquilibres internes. / This thesis aims to study the global imbalances with an empirical multinational stock-flow consistent model. The last financial crisis, which was followed by a global economic crisis, has reconfigured the evolution of many macroeconomic variables. Global imbalances have strongly resorbed and this continuing adjustment results mainly from cyclical macroeconomic factors, due to the collapse in demand. Given the major changes in the recent years, we analyze in our research growth prospects in the United States, in China and Europe in the case of the continuation of current economic policies, over the period running up to 2030. For that purpose, we first use the C.A.M model developed by F. Cripps. We then estimate our own five bloc multinational model. We focus on analyzing the evolution of global imbalances, the economic growth and the exchange rate. The baseline scenario projections of our multinational model, in the case of the continuation of the current economic policies, show that the adjustment of the external imbalances is maintained at the cost of internal imbalances.

In this thesis, a new modeling technique is proposed for minimizing regression testing effort in software product lines. The &ldquo / Product Flow Model&rdquo / is used for the common representation of products in application engineering and the &ldquo / Domain Service and Object Model&rdquo / represents the variant based relations between products and core assets. This new approach provides a solution for avoiding unnecessary work load of regression testing using the principles of sub-service decomposition and variant based product/sub-service traceability matrices. The proposed model is adapted to a sample product line targeting the banking domain, called Loyalty and Campaign Management System, where loyalty campaigns for credit cards are the products derived from core assets. Reduced regression test scope after the realization of new requirements is demonstrated through a case study. Finally, efficiency improvement in terms of time and effort in the test process with the adaptation of the proposed model is discussed.

Thesis (PhD (Logistics))--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: South Africa currently experiences the double jeopardy problem of catching up to global economic competitiveness whilst at the same time feeling the pressures of sustainability management spearheaded by a global agenda. Global sustainability is defined as growth that is shared without depleting natural resources or damaging the environment. Academic disciplines are challenged to make a contribution and economics as such should contribute by providing the lead and lag indicators for the planning and measurement of scarce resources usuage. This integrative view includes economic subdisciplines, such as logistics. This integrative view is an acknowledged part of the economics discipline, except that the macro-economic context of some sub-disciplines, such as logistics, often receives less attention during the course of academic activities. The distribution of resources and outputs in the economy is a logistics controlled cross-cutting factor, but suffers from a lack of macro-economic perspective, and lead and lag orientated measurement. This state of the affairs is a historic backlog of logistics and its specific position within economics. During the primary economic era the world began to configure networks and markets, which became more pronounced and settled with the dawn and settling of the industrial era. Logistics then was a “given” and did not receive much thought even as industrial, market economies developed. Transport was regarded as an administered cost, i.e. inefficiencies in logistics systems were evenly distributed between competitors, not giving any specific entity an advantage. With the advent of global competition and the diminishing returns on other cost saving measures, companies began to collaborate and integrate logistics functions within value chains, but the administered part of transport costs failed to receive the attention it required. In this way, global competitors did begin to experience disadvantages on a national level as whole economies suffered from inefficiencies in logistics and specifically transport systems.

Rapid development and growth of industrialization has brought immense enrichments in living standards of humans, however, improper planned development also brings along several environmental problems such as pollution of environment and excessive consumption of natural resources. Among all the others, uncontrolled utilization of water poses a severe threat to the coming generations. Past decades have witnessed water shortage in various countries of the world. Although about 80% of the earth’s surface is covered with water, around 97.2% of water is salty making it inappropriate for general usage. Among the rest of the 2.8%, which is present as fresh water on surface, a large proportion of it has been found to be severely polluted. The increasing demand of fresh water both for industrial and domestic usage adds great demand on the available groundwater. Moreover, the severe pollution of fresh water on the surface adds more stress on the available groundwater. In Australia, approximately 20% of water supply is from groundwater and in the case of Western Australia groundwater provides two thirds of its water supply needs. Thus, it is important to manage groundwater sources in Western Australia to achieve the optimum water utilization and maintain the water table and it is also essential to decide on an appropriate water budget. Groundwater flow modelling is an effective tool to get appropriate water distribution and, to examine effects from pumping on water levels and direction of groundwater flow paths, thereby helping in its proper management and utilization. Apart from monitoring the flow and utilization, groundwater flow modeling is also vital to keep the track of pollutant in the groundwater. Increasing surface pollution and landfill sites tend to pollute the groundwater due to leaching. / The above mentioned aspects formed the basis of the present research. A groundwater flow model was developed in Visual MODFLOW Premium to study the effect of three different types of soil in and around Perth region. This study also shows the hypothetical contaminated site model for benzene, toluene, ethylbenzene and xylene (BTEX) transport in Perth Superficial unconfined aquifer which includes three major aquifer sediments namely Bassendean Sand, Safety Bay Sand and Tamala Limestone. Among the four different contaminants it was observed that benzene is able to migrate quickly as compared to the other contaminants due to its smaller distribution coefficient. / This study also explored the major soil parameters such as effect of sorption, effective porosity and hydraulic conductivity on contaminant plume configuration and contaminants concentration for the three types of aquifer sediments. A critical comparison of the behaviour of the three different types of soils was also conducted. / Simulation results of sensitivity analysis have shown that sorption and hydraulic conductivity greatly affected the contaminant plume length and concentration of contaminants with much lesser effect shown by the effective porosity. The simulated results also showed that the movement of contaminant in Tamala Limestone is most rapid by comparing these three types of aquifer sediments together. Thus, it can be said that contaminated sites found in Tamala Limestone needs immediate remediation of contaminants to bring down the contaminants concentration in groundwater. / In brief, the thesis explores the current groundwater scenario in and around Perth region. Based on the information a hypothetical scenario simulation has critically analyzed the various parameters affecting the water and contaminant flow for the various soil parameters. The study is considered as a building block for further research on developing a remediation technique for groundwater contaminant treatment.

Les mélanges multiphasiques en déséquilibre de vitesse sont habituellement modélisés à l'aide d'un modèle à 6 ou 7 équations (Baer and Nunziato, 1986). Ces modèles sont très efficaces pour traiter des mélanges avec effets d'interpénétration. Ils peuvent aussi être utilisés pour traiter des problèmes à interface dans lesquels il est nécessaire de respecter les conditions d'interface (continuité de la vitesse normale et de la pression). Ceci est réalisé à l'aide de solveurs de relaxation mécanique (Saurel and Abgrall, 1999). Une autre méthode consiste à utiliser un modèle à une vitesse et une pression (Kapila et al., 2001). Cependant, de nombreuses applications font intervenir des interfaces instables entre fluides. On traite habituellement ces zones de mélanges turbulents en utilisant un modèle à une vitesse et en résolvant spatialement les diverses instabilités. Dans de nombreuses applications cela devient impossible en raison du trop grand nombre de « jets » et de « bulles ». De plus, on rencontre des difficultés numériques y compris pour le calcul d'une instabilité isolée (Liska and Wendroff, 2004). Dans ce manuscrit, nous abordons le problème de la modélisation des zones de mélange avec des modèles multiphasiques. Cela pose un sérieux problème de modélisation pour des écoulements évoluant d'une situation où l'interface est bien définie (une seule vitesse) vers une configuration de mélange de fluides à plusieurs vitesses. Cette question a été abordée par Besnard and Harlow (1988), Youngs et al. (1989), Chen et al. (1996), Glimm et al. (1999), Saurel et al. (2003) par exemple. / Multiphase mixtures with velocity disequilibrium are usually modelled with 6 or 7 equations models (Baer and Nunziato, 1986). These models are very efficient to model mixtures with velocity drift effects. They can also be used to model interfacial flows where the respect of interface conditions (continuous normal velocity and pressure) is mandatory. Such aim is usually achieved with the help of stiff mechanical relaxation solvers (Saurel and Abgrall, 1999). Another option is to use single pressure and single velocity models (Kapila et al., 2001). However, many applications involve unstable fluid-fluid interfaces for which flow conditions range from well separated fluids to fully mixed ones. The usual way to deal with these turbulent mixing zones is to use a single velocity flow model and to resolve spatially the various instabilities. However, spatial resolution of these instabilities in many applications is impossible as too many ‘jets' and ‘bubbles' are present. Also, numerical difficulties and large inaccuracies are present even for an isolated instability computation (Liska and Wendroff, 2004). In this work, we address the issue of mixing zone modelling with multiphase flow models. This poses the serious difficulty of model derivation for flows conditions ranging from well defined interfaces (single velocity) to fluid mixtures evolving with several velocities. This issue has been addressed by Besnard and Harlow (1988), Youngs et al. (1989), Chen et al. (1996), Glimm et al. (1999), Saurel et al. (2003) to cite a few. In Saurel et al. (2010) an extension of the Kapila et al. (2001) model was done to deal with permeation effects through material interfaces.

Submitted by Geyciane Santos (geyciane_thamires@hotmail.com) on 2015-10-23T13:48:35Z No. of bitstreams: 1 Dissertação - Alderlene Pimentel de Brito.pdf: 9770661 bytes, checksum: 52d80b8bc977737e79011f31b936442e (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-10-26T18:54:54Z (GMT) No. of bitstreams: 1 Dissertação - Alderlene Pimentel de Brito.pdf: 9770661 bytes, checksum: 52d80b8bc977737e79011f31b936442e (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-10-26T19:00:50Z (GMT) No. of bitstreams: 1 Dissertação - Alderlene Pimentel de Brito.pdf: 9770661 bytes, checksum: 52d80b8bc977737e79011f31b936442e (MD5) / Made available in DSpace on 2015-10-26T19:00:51Z (GMT). No. of bitstreams: 1 Dissertação - Alderlene Pimentel de Brito.pdf: 9770661 bytes, checksum: 52d80b8bc977737e79011f31b936442e (MD5) Previous issue date: 2014-12-02 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The groundwater flow behavior is of fundamental importance for the development of the biotic environment and maintenance of life, because the availability of water in a given environment influence the growth and distribution of species. The Amazon forest is one of the most important tropical forests in the world, depending on their size and number of species, however, has na environment sensitive to climate variability and change, of anthropogenic or natural origin. From a stationary numerical model developed for the aquifer was possible to estimate the groundwater flow behavior of current and future water using precipitation data report of the Intergovernmental Panel on Climate Change (IPCC – CMIP5 model) for the years 2035, 2065 and 2100. The results show that the value of the base flow stream studied darcyano determined from the flux at the local groundwater aquifer is 3,6x10-4 m3 / s, almost na order of magnitude smaller than the result obtained by determining the flow of the stream in a period without precipitation, 4,8x10-3m3 / s. For the year 2035 is the value of 4,7x10-3 m3 / s, while 2065 and 2100 values are: 2,7x10-3 m3 / s; and 2,5x10-3 m3 /. This downgrade affects the availability of water for vegetation shallow roots. Changes in water level by 2100 could affect the availability of water for the Reserva Florestal Adolpho Ducke. / O comportamento do fluxo de água subterrânea é de fundamental importância para o desenvolvimento do meio biótico e manutenção da vida, pois a disponibilidade de água em dado ambiente influenciará o crescimento e distribuição de espécies. A floresta amazônica é uma das mais importantes florestas tropicais do mundo, em função da sua extensão e conjunto de espécies, entretanto, possui um ambiente sensível a variações e mudanças climáticas, de origem antrópica ou natural. A partir de um modelo numérico estacionário elaborado para o aquífero foi possível estimar o comportamento do fluxo subterrâneo de água atual e futuro, usando dados de precipitação do relatório do Painel Intergovernamental sobre Mudanças Climáticas (IPCC - modelo CMIP5) para os anos de 2035, 2065 e 2100. Os resultados mostram que valor do fluxo de base do igarapé estudado, determinado a partir do fluxo darcyano no aquífero freático local, é de 3,6x10-4 m3/s, quase uma ordem de magnitude menor do que o resultado obtido pela determinação da vazão do igarapé em um período sem precipitação, de 4,8x10-3m3/s. Para o ano de 2035 o valor é de 4,7x10-3 m3/s, enquanto que para 2065 e 2100 os valores são: 2,7x10-3 m3/s; e 2,5x10-3 m3/. Tal rebaixamento afeta a disponibilidade de água para a vegetação de raízes pouco profundas. Modificações no nível da água até 2100 poderão influenciar a disponibilidade de água para a Reserva Florestal Adolpho Ducke.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-09-28T12:18:00Z No. of bitstreams: 1 lucimaradasilvabastos.pdf: 897863 bytes, checksum: 11fdf4ad0d00dee3360f281139b0b603 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-09-28T14:14:26Z (GMT) No. of bitstreams: 1 lucimaradasilvabastos.pdf: 897863 bytes, checksum: 11fdf4ad0d00dee3360f281139b0b603 (MD5) / Made available in DSpace on 2017-09-28T14:14:26Z (GMT). No. of bitstreams: 1 lucimaradasilvabastos.pdf: 897863 bytes, checksum: 11fdf4ad0d00dee3360f281139b0b603 (MD5) Previous issue date: 2017-08-08 / Este estudo tem como tema central a transformação do Estado e as políticas públicas educacionais no século XXI ocorridas no Brasil. Em detrimento à influência das mudanças internacionais que contribuíram para a construção do cenário no país, o estudo foca-se nas políticas de responsabilização (accountability), por produzirem grande impacto nas transformações dos sistemas educacionais, tanto no que tange as estruturas econômicas e sociais originárias dos sistemas sócio-políticos no seu percurso histórico, quanto os processos de avaliação da educação. Como hipótese, percebe-se o Estado como produto de sua sociedade e que, portanto, se transforma em função das mudanças sociais, derivadas de suas dialéticas estruturais. Após a contextualização histórica e teórica, passando pela formação do Estado brasileiro, de suas políticas públicas e modelos de gestão educacional, parte-se para o aprofundamento da análise de politicas públicas a partir modelo de fluxos mútiplos de Kingdon. Foram investigados artigos publicados em dezenove revistas científicas representativas da Sociologia da Educação no Brasil entre os anos 2000 e 2014. A base constitui-se inicialmente por 5.792 artigos sobre educação, sociologia e campos correlatos. O recorte dos artigos foi realizado por meio de análise de qualificação dos periódicos, tendo em vista a classificação mínima observada na seleção dos artigos (qualis B2, B1, A2 ou A1) e com abordagens plurais, com o fito de diversificar a análise ora proposta. Após sucesivas seleções foram identificadas 47 produções representativas da reflexão sobre o objeto, com especial atenção às mudanças do Estado e/ou do campo educacional e as interpretações dadas às transformações observadas, tendo em vista, a promoção das reformas e de novas agendas. Além disso, toda a análise teve como parâmetro os três fluxos de atores e questões no processo de formulação das políticas públicas: o dos problemas, o das políticas, soluções ou alternativas estabelecidas pelo Modelo de Fluxos Múltiplos de Kingdon. O objetivo era o de alcançar e possibilitar a identificação das interpretações que os autores apresentam mediante os padrões de mudanças das políticas educacionais na atualidade, efetivado através da implementação de diversas políticas públicas, em especial observando e registrando a mudança de paradigma ocorrida nos últimos tempos. O estudo concluiu que, desde o início da formação do Estado brasileiro, o país sofreu fortes influências ideológicas e econômicas, sendo a recente agenda governamental ser associada à combinação entre problemas conjunturais, propostas em pauta com seus respectivos argumentos instruídos por diferentes atores e campos e as condições políticas, elementos que marcam na análise de fluxos múltiplos e se mostraram adequados à análise do objeto. / This study has as its central theme the transformation of the State and the educational public policies in the 21st century in Brazil. In detriment to the influence of the international changes that contributed to the construction of the scenario in the country, the study focuses on the policies of accountability, since they have a great impact on the transformations of the educational systems, as far as the original economic and social structures are concerned Of socio-political systems in their historical course, as well as the processes of evaluation of education. As a hypothesis, the state is perceived as the product of its society and, therefore, becomes a function of the social changes derived from its structural dialectics. After the historical and theoretical contextualization, through the formation of the Brazilian State, of its public policies and educational management models, one starts to deepen the analysis of public policies from Kingdon's multiple flows model. Articles published in nineteen scientific journals representing the Sociology of Education in Brazil between 2000 and 2014 were investigated. The base initially consisted of 5,792 articles on education, sociology and related fields. The articles were classified according to the classification of the articles (qualis B2, B1, A2 or A1) and with plural approaches, in order to diversify the analysis proposed here. After successive selections, 47 representative productions of the reflection on the object were identified, with special attention to the changes of the State and / or the educational field and the interpretations given to the changes observed in order to promote the reforms and new agendas. In addition, the whole analysis had as parameter the three flows of actors and questions in the public policy formulation process: that of the problems, the policies, solutions or alternatives established by the Kingdon Multiple Flow Model. The objective was to reach and enable the identification of the interpretations that authors present through the current patterns of educational policy changes, implemented through the implementation of several public policies, especially observing and recording the paradigm shift that has occurred in recent times. The study concluded that since the beginning of the formation of the Brazilian State the country has suffered strong ideological and economic influences, and the recent governmental protocols is associated with the combination of conjunctural problems, proposals on the protocol, with their respective arguments instructed by different actors and fields, and The political conditions, elements that mark the analysis of multiple flows and proved adequate for the analysis of the object.

The target of Zero Waste "Valuation and business planning" for a potential investor is to explore and evaluate the identified market opportunity. Business plan concerns the foundation of food and consumer goods retail business which is aimed towards reducing consumers negative impact on the environment, supporting local jobs and sustainable farming. The thesis is based on theoretical knowledge from the publications listed in the resources which were confronted with the reality in interviews with the owners of comparable businesses. Resulting from the business planning a calculation of present value of the proposed model enterprise has been made. Value calculated using discounted cash flows had shown that cannot be unequivocally recommended to establish the company. Pessimistic scenario shows a negative net present value and realistic option shows a positive net present value. However it is necessary to understand the thesis as a model business plan for valuation of such businesses. As for example with a different form of funding or reduction of initial investment, the company may change to a version that would be recommendable to implement.

The world's energy demand has been rapidly increasing and is projected to continue growing for at least the next two decades. With increasing global energy demand and competition from renewable energy, the oil and gas industry is striving for more efficient petroleum production. Many technical breakthroughs have enabled the drilling industry to expand the exploration to more difficult drilling such as deepwater drilling and multilateral directional drilling. For example, managed pressure drilling (MPD) offers ceaseless operation with multiple manipulated variables (MV) and wired drill pipe (WDP) provides two-way, high-speed measurements from bottom hole and along-string sensors. These technologies have maximum benefit when applied in an automation system or as a real-time advisory tool. The objective of this study is to investigate the benefit of nonlinear model-based control and estimation algorithms with various types of models. This work presents a new simplified flow model (SFM) for bottomhole pressure (BHP) regulation in MPD operations. The SFM is embedded into model-based control and estimation algorithms that use model predictive control (MPC) and moving horizon estimation (MHE), respectively. This work also presents a new Hammerstein-Wiener nonlinear model predictive controller for BHP regulation. Hammerstein-Wiener models employ input and output static nonlinear blocks before and after linear dynamics blocks to simplify the controller design. The control performance of the new Hammerstein-Wiener nonlinear controller is superior to conventional PID controllers in a variety of drilling scenarios. Conventional controllers show severe limitations in MPD because of the interconnected multivariable and nonlinear nature of drilling operations. BHP control performance is evaluated in scenarios such as drilling, pipe connection, kick attenuation, and mud density displacement and the efficacy of the SFM and Hammerstein-Wiener models is tested in various control schemes applicable to both WDP and mud pulse systems. Trusted high-fidelity drilling simulators are used to simulate well conditions and are used to evaluate the performance of the controllers using the SFM and Hammerstein-Wiener models. The comparison between non-WDP (semi-closed loop) and WDP (full-closed loop) applications validates the accuracy of the SFM under the set of conditions tested and confirms comparability with model-based control and estimation algorithms. The SFM MPC maintains the BHP within ± 1 bar of the setpoint for each investigated scenario, including for pipe connection and mud density displacement procedures that experience a wider operation range than normal drilling.