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Power quality related problems cause large financial losses in the order of billions worldwide. The evaluation process aimed at determining effective remedial actions starts with the correct identification and characterization of power quality disturbances. Measurements performed in the electrical power network and the corresponding collection and process of data are the primary method of characterization of the phenomena. The ideal deployment of monitoring devices would entail a monitor installed at each node of the network so that the power quality throughout the system could be directly assessed. In reality, however, technical and mostly economical constraints limit the number of monitors a network operator can install in the system. Power quality at non-monitored sites, therefore, has to be estimated by extrapolating the data from monitored sites. Consequently, it is crucial to identify the sites that provide the most accurate picture of the system’s overall power quality. Unfortunately, no recommended practices or guidelines for determining the minimum number and the best locations for optimal power quality monitoring have been prescribed in standards or reports. This thesis investigates voltage sag monitoring as part of a larger power quality monitoring scheme. The aim is to develop a methodology for optimal monitor placement for fault location and sag estimation. The thesis, divided in four main parts, focuses on network sag performance estimation and optimal monitor placement for fault localization and sag estimation. The introductory part of the thesis gives an overview of power quality surveys conducted around the world in recent years with special emphasis on the monitor placement criteria used. It also summarizes the main methods for network sag performance estimation proposed to date. The main part of the thesis firstly reviews the most referred optimal monitor placement method for sag estimation proposed in academia, highlighting its limitations. Then a robust fault location algorithm is proposed to enhance this method and overcome the identified limitations. The enhanced method is thereafter used as the basis for the generalization of one of the leading methods for optimal monitor placement for fault location in the second part of the thesis. The formulation of its optimization problem is extended for application in large power networks by adapting the modeling approach for the sag monitor placement problem. To reduce the high computational and memory burden associated with finding the optimal fault location monitor program, the thesis introduces a less memory intensive heuristic search algorithm in the third part of the thesis. A series of custom objective functions are proposed to be used with this algorithm to find optimal fault location and sag monitoring programs aimed at estimating the most critical events for customers. In the final part of the thesis, the main concepts and techniques introduced in the first three sections are combined to develop a synergistic approach to optimal monitor placement for sag characterization based on fault location. The suitability of the new method for techno-economic assessment of voltage sags using strategically or conventionally deployed monitors is established.

Este trabalho consistiu no desenvolvimento e análise comparativa de rotas de cominuição para Itabiritos Compactos do Quadrilátero Ferrífero a partir de uma amostra de grande volume. As rotas desenvolvidas foram: Rota Convencional, composta por quatro estágios de britagem até a malha de 12 mm, seguido por moagem em moinho de bolas. Rota SAB, composta por uma etapa de britagem até a malha de 200 mm, seguida por moagem SAG e moagem em moinho de bolas. Para esta rota foi estudada a inclusão de uma segunda etapa de britagem, antes da alimentação do moinho SAG, e de uma britagem de pebbles, para a carga circulante do moinho SAG. Rota SSSAG, composta por uma etapa de britagem seguida por moagem SAG. Assim como para a rota SAB, foi avaliada para esta última rota a inclusão de uma segunda etapa de britagem, antes da alimentação do moinho SAG. Em todas as rotas, o produto da moagem foi fixado em 10% retido em 0,15 mm Os circuitos de moagem, SAG e de moinho de bolas foram desenvolvidos a partir de resultados de ensaios em escala piloto, ajustados via simulador JKSimMet. O consumo de energia e o dimensionamento dos equipamentos obtidos a partir dos ensaios piloto foram comparados aos resultados obtidos pelos métodos Bond e de Donda. O circuito de britagem foi dimensionado a partir de um ensaio industrial, que determinou a eficiência de britagem em função da abertura na posição fechada do britador. As rotas desenvolvidas foram comparadas quanto ao consumo específico de energia (kWh/t), dimensionamento dos equipamentos e geração de material menor que 0,010 mm (lamas) no produto da moagem. A rota SSSAG apresentou o menor consumo de energia e também o menor quantitativo de equipamentos. Quanto à geração de lama no produto da moagem, foram obtidos valores semelhantes nos ensaios piloto das três rotas estudadas. / This work consists in the development and comparative analysis of comminution routes to Compact Itabirites from Quadrilátero Ferrífero, based on a large volume sample. The developed routes were: Conventional Route, comprising four crushing stages, down to 12 mm, followed by ball milling. SAB Route comprising one crushing step, down to 200 mm, followed by SAG milling and ball milling. Secondary crushing and pebble crushing were also included as variations of SAB route. Route SSSAG, comprising one crushing step, down to 200 mm, followed by SAG milling. Secondary crushing was also included as a variation of SSSAG route. In all cases grinding product was set to 10% retained at 0,15 mm. All grinding models were fitted at JKSimMet simulator on the basis of pilot plant data. Energy consumption and equipment design were compared with Bond and Donda method results. Crushing circuit design was based on industrial tests carried out for determining efficiency as a function of closed side setting (CSS). The routes were compared in term of energy consumption (kWh/t), comminution equipment numbers and the amount passing at 0,010 mm (slimes) in the grinding circuit product. The SSSAG route indicated the lowest energy consumption, together less pieces of equipment. Similar slime values were obtained for all three routes in pilot testing.

Group A streptococcus (GAS) is a strictly human pathogen that causes infections ranging from asymptomatic carriage to the highly lethal streptococcal toxic shock syndrome (STSS). GAS are classified according to the sequence of the variable 5’ end of the emm-gene that encodes the surface associated M-protein. In the late 1980s, outbreaks of GAS infections with high rates of STSS were reported in several parts of the world, including Sweden. Superantigens (SAgs), a group of exotoxins, have been described as key mediators of STSS due to their capacity to polyclonally activate T-cells and induce a massive release of inflammatory cytokines. Previous reports have revealed that sera from STSS patients have lower capacity to neutralize this SAg-mediated immune stimulation and a higher prevalence of GAS isolates with specific emm-genotypes during disease outbreaks. The aims of this thesis were to analyse the protective antibody response mounted by the host against SAgs produced by the infecting GAS isolate and to characterise the isolates emm-genotypes and SAg gene profiles. The clinical material examined was collected from patients with STSS, sepsis, erysipelas, or tonsillitis in Sweden between 1986 and 2001. Both acute- and convalescence-phase sera were analyzed, along with the infecting GAS isolates. The 92 clinical GAS isolates examined were found to exhibit a high degree of genetic diversity in terms of the number and identity of their SAg genes. Isolates with a given emm-genotype could be divided into subgroups on the basis of their SAg gene profiles. Ten different SAg gene profiles were identified in the 45 emm1 isolates examined; one of these ten was highly persistent, being observed in 22 isolates collected over 14 years. Two of the 11 known SAg genes in GAS, smeZ-1 and speA, were more prevalent in the emm1 associated profiles than in the SAg gene profiles of isolates with other emm-genotypes. Patients infected by GAS with the emm1-genotype were less likely to produce acute-phase sera that could effectively neutralize the T-cell mitogenicity induced by the infecting isolate’s extracellular products (EP). Sepsis patients whose sera exhibited this lack of neutralizing ability were more prone to developing STSS. Most patients whose acute-phase sera did not effectively neutralize the EP from the infecting isolate lacked protective antibodies in their convalescent-phase sera despite having elevated ELISA titers. The results reported herein show that combining SAg gene profiling with emm-genotyping may be useful for tracking the spread of GAS clones in the community. It was also shown that a lack of neutralizing activity in convalescence-phase sera might be due to an inability of those patients to mount a protective immune response against SAgs produced by the infecting GAS isolate.

Este trabalho consistiu no desenvolvimento e análise comparativa de rotas de cominuição para Itabiritos Compactos do Quadrilátero Ferrífero a partir de uma amostra de grande volume. As rotas desenvolvidas foram: Rota Convencional, composta por quatro estágios de britagem até a malha de 12 mm, seguido por moagem em moinho de bolas. Rota SAB, composta por uma etapa de britagem até a malha de 200 mm, seguida por moagem SAG e moagem em moinho de bolas. Para esta rota foi estudada a inclusão de uma segunda etapa de britagem, antes da alimentação do moinho SAG, e de uma britagem de pebbles, para a carga circulante do moinho SAG. Rota SSSAG, composta por uma etapa de britagem seguida por moagem SAG. Assim como para a rota SAB, foi avaliada para esta última rota a inclusão de uma segunda etapa de britagem, antes da alimentação do moinho SAG. Em todas as rotas, o produto da moagem foi fixado em 10% retido em 0,15 mm Os circuitos de moagem, SAG e de moinho de bolas foram desenvolvidos a partir de resultados de ensaios em escala piloto, ajustados via simulador JKSimMet. O consumo de energia e o dimensionamento dos equipamentos obtidos a partir dos ensaios piloto foram comparados aos resultados obtidos pelos métodos Bond e de Donda. O circuito de britagem foi dimensionado a partir de um ensaio industrial, que determinou a eficiência de britagem em função da abertura na posição fechada do britador. As rotas desenvolvidas foram comparadas quanto ao consumo específico de energia (kWh/t), dimensionamento dos equipamentos e geração de material menor que 0,010 mm (lamas) no produto da moagem. A rota SSSAG apresentou o menor consumo de energia e também o menor quantitativo de equipamentos. Quanto à geração de lama no produto da moagem, foram obtidos valores semelhantes nos ensaios piloto das três rotas estudadas. / This work consists in the development and comparative analysis of comminution routes to Compact Itabirites from Quadrilátero Ferrífero, based on a large volume sample. The developed routes were: Conventional Route, comprising four crushing stages, down to 12 mm, followed by ball milling. SAB Route comprising one crushing step, down to 200 mm, followed by SAG milling and ball milling. Secondary crushing and pebble crushing were also included as variations of SAB route. Route SSSAG, comprising one crushing step, down to 200 mm, followed by SAG milling. Secondary crushing was also included as a variation of SSSAG route. In all cases grinding product was set to 10% retained at 0,15 mm. All grinding models were fitted at JKSimMet simulator on the basis of pilot plant data. Energy consumption and equipment design were compared with Bond and Donda method results. Crushing circuit design was based on industrial tests carried out for determining efficiency as a function of closed side setting (CSS). The routes were compared in term of energy consumption (kWh/t), comminution equipment numbers and the amount passing at 0,010 mm (slimes) in the grinding circuit product. The SSSAG route indicated the lowest energy consumption, together less pieces of equipment. Similar slime values were obtained for all three routes in pilot testing.

Ingeniero Civil Electricista / El objetivo del presente trabajo de título es analizar y diseñar un sistema que permita monitorear los costos operaciones de los procesos mineros y controlarlos de forma indirecta a través de la supervisión y manipulación de variables críticas del proceso en estudio. Además el sistema tiene que ser capaz de recolectar automáticamente lo datos relevantes provenientes del sistema de control y de plantas, como también ser capaz de generar reportes con la información generada. Este trabajo se enmarca en el estudio que se realizó en la mina Chuquicamata de la empresa estatal Codelco Chile, en particular en el proceso de molienda semiautógena de la Planta Concentradora. Para el desarrollo de este trabajo se considera una etapa de estudio y recolección de información tanto de la empresa y la industria de las mineras cupríferas como también de los procesos relacionados a la investigación. Posteriormente se analiza los costos operacionales de la Planta Concentradora, relacionando aquellos provenientes de las actividades de la molienda con las variables operacionales críticas. A continuación se realiza un diseño del sistema y la aplicación teniendo en cuenta los requerimientos de los usuarios, en este caso, profesionales y especialistas de la empresa, y las restricciones existentes del sistema de control. Como herramienta de diseño se utiliza UML, que es un lenguaje de modelamiento de sistemas de software. Finalmente se implementan algunos módulos, relacionados con el diseño, de la plataforma RtPM que utiliza actualmente Codelco para la recolección, manejo y repositorio de la información de planta. Como resultado hoy en día la Planta Concentradora posee un diseño de una herramienta de gestión para controlar los costos operacionales de la molienda semiautógena y además posee datos bases que alimenten el sistema. En consecuencia, es posible calcular y generar los indicadores presentados en este trabajo como también aquellos que se consideren a futuro necesarios para apoyar la administración y gestión de los procesos.

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<p><p>In this work growth of cubic GaN in the selective area (SA) MOVPE process is</p><p>simulated. The simulations are restricted to small pattern SA MOVPE growth.</p><p>In this case the traditional MOVPE growth and the enhanced growth caused by</p><p>surface diffusion are important growth factors. The lateral vapor phase diffusion</p><p>is ignored while this process only has a small impact on the enhanced growth in</p><p>the small pattern SA growth. The model is build for simulation of anisotropic</p><p>growth. It has been shown that different type of anisotropic growth occurs when</p><p>the mask pattern are orientated in different directions on the substrate. While</p><p>the anisotropic growth is not well understood two different models are studied in</p><p>this work.</p><p>The simulation is restricted to the geometrical growth characteristics such</p><p>as mask and crystal width, mask alignment and surface diffusion on the crystal.</p><p>The reactor geometry, pressure and growth temperature are not investigated that</p><p>closely and are only treated as constants in the model.</p><p>The model used in this simulation gives good results for short time simulations</p><p>for some certain cases. The model shows that the fill factor has a greater</p><p>impact on the grown shapes than the individual mask and crystal width. But</p><p>there are problems with the anisotropic and flux from mask modeling while some</p><p>facets do not appear and the lateral growth along the mask show doubtful results.</p><p>The model show good results in short time growth and predict some important</p><p>characteristics in SA MOVPE.</p></p>

In this work growth of cubic GaN in the selective area (SA) MOVPE process is simulated. The simulations are restricted to small pattern SA MOVPE growth. In this case the traditional MOVPE growth and the enhanced growth caused by surface diffusion are important growth factors. The lateral vapor phase diffusion is ignored while this process only has a small impact on the enhanced growth in the small pattern SA growth. The model is build for simulation of anisotropic growth. It has been shown that different type of anisotropic growth occurs when the mask pattern are orientated in different directions on the substrate. While the anisotropic growth is not well understood two different models are studied in this work. The simulation is restricted to the geometrical growth characteristics such as mask and crystal width, mask alignment and surface diffusion on the crystal. The reactor geometry, pressure and growth temperature are not investigated that closely and are only treated as constants in the model. The model used in this simulation gives good results for short time simulations for some certain cases. The model shows that the fill factor has a greater impact on the grown shapes than the individual mask and crystal width. But there are problems with the anisotropic and flux from mask modeling while some facets do not appear and the lateral growth along the mask show doubtful results. The model show good results in short time growth and predict some important characteristics in SA MOVPE.

With the increase of sensitive loads in industrial and commercial customers, more attention has been paid to the power quality problems. Voltage sag is among the major power quality problems that cause interruptions in production lines that result in significant losses. Power quality mitigation devices, that provide different protection levels, can be adopted to match individual customer¡¦s special needs. This thesis presents a cost-benefit assessment of various voltage sag mitigation options at locations with different types of distribution feeders and customers. Simulation results have revealed that using the assumed power quality cost data, the installation of small capacity and low cost UPS has the highest benefit/cost ratio in all the options tested.