Water Treatment Plants (WTPs) supply potable water which is transferred by pumps to various end users. WTPs and other sub-systems are energy intensive with pump installed capacities varying between 75 kW – 6 000 kW. It has therefore become important to optimise the utilisation of WTPs. Cost savings can be achieved and the load on the national grid can be reduced. The aim of this study is to develop and implement load management strategies on a municipal WTP. In this investigation the high lift pumps are deemed to be the largest consumers of electricity. Strategies to safely implement load management on a WTP were researched. By optimising the operations of the pumps, significant cost savings can be achieved. Comparisons between different electricity tariff structures were done. It was found plausible to save R 990 000 annually, on a pumping station with four 1 000 kW pumps installed, when switching to a time-of-use dependent tariff structure. Strategies to optimise plant utilisation while attempting a load management study include the optimisation of filter washing methods and raw water operations. An increase of 34% in efficiency for a filter backwash cycle was achieved. To accommodate the effects of the load management on the WTP, the operation of valves that allow water to distribute within the plant was also optimised. The implemented control strategies aimed to accomplish the full utilisation of the WTP and sub-systems to achieve savings. An average evening peak period load shift impact of 2.21 MW was achieved. Due to filter modifications the plant is able to supply 5% more water daily. A conclusion is drawn regarding the success of the strategies implemented. Recommendations are made for further research. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015

Water Treatment Plants (WTPs) supply potable water which is transferred by pumps to various end users. WTPs and other sub-systems are energy intensive with pump installed capacities varying between 75 kW – 6 000 kW. It has therefore become important to optimise the utilisation of WTPs. Cost savings can be achieved and the load on the national grid can be reduced. The aim of this study is to develop and implement load management strategies on a municipal WTP. In this investigation the high lift pumps are deemed to be the largest consumers of electricity. Strategies to safely implement load management on a WTP were researched. By optimising the operations of the pumps, significant cost savings can be achieved. Comparisons between different electricity tariff structures were done. It was found plausible to save R 990 000 annually, on a pumping station with four 1 000 kW pumps installed, when switching to a time-of-use dependent tariff structure. Strategies to optimise plant utilisation while attempting a load management study include the optimisation of filter washing methods and raw water operations. An increase of 34% in efficiency for a filter backwash cycle was achieved. To accommodate the effects of the load management on the WTP, the operation of valves that allow water to distribute within the plant was also optimised. The implemented control strategies aimed to accomplish the full utilisation of the WTP and sub-systems to achieve savings. An average evening peak period load shift impact of 2.21 MW was achieved. Due to filter modifications the plant is able to supply 5% more water daily. A conclusion is drawn regarding the success of the strategies implemented. Recommendations are made for further research. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015

In the last few years, engagement in medical care among individuals living with HIV has become a major priority among HIV medical providers and public health researchers. Engagement in medical care is an important concept as it involves the process of linking newly diagnosed individuals into medical care and retaining those individuals in care throughout the course of their infection. Although there have been major advances in the management of HIV, like the advent of Highly Active Antiretroviral Therapy, morbidity and mortality due to HIV cannot be fully reduced if the individual does not optimally retain in care. Retention in HIV medical care has become an emerging topic in HIV research, but there still remains a scarce amount of research on how to properly define retention, understand its predictors, and how it impacts HIV outcomes. The purpose of this dissertation was to evaluate retention in HIV medical care among individuals diagnosed with HIV and seeking care at an urban infectious disease clinic in Kentucky. The three specific aims of this dissertation were to: (1) compare methods in measuring retention in HIV medical care; (2) determine the predictors of poor retention in care and assess the effect of non-HIV related comorbidities have on retention over time; and (3) determine the impact early retention to medical care has on time to viral load suppression and rebound among individuals initiating Highly Active Antiretroviral Therapy. A retrospective cohort study was conducted employing a medical chart review, and patients who sought HIV care at the Bluegrass Care Clinic between January 1st 2003 and May 1st 2011 were eligible for the study. There were 1,358 patients included in the study and these individuals were followed until December 31st, 2011. The results suggested that individuals living with HIV should seek care at least once every six months (visit constancy) and that only 48.6% of the study population obtained optimal retention over time. Over time the rate of retention decreased among the study sample and those with optimal retention were more likely to suppress their viral loads compared to poor retainers.

The purpose of this study was to validate a stress inventory which would differentiate between a normative group and a patient population suffering from environmental illness. The hypotheses of this study were: (1) the Total Stress Load Inventory would be predictive in discriminating between clinical ecology patients and a normative group; (2) each section or subscale of the Total Stress Load Inventory would be predictive of psychological, cognitive, nutritional, and/or medical factors.

O perfil de consumo de energia elétrica dos consumidores necessita ser conhecido em detalhe para muitos estudos, sejam eles técnicos ou comerciais. Esse conhecimento pode ser alcançado através da obtenção das curvas de carga de todos os clientes da empresa, porém, devido ao grande número de medidores necessários, essa prática é inviável. A alternativa utilizada atualmente nas revisões tarifárias do sistema elétrico brasileiro emprega a teoria de amostragem associada a técnicas de análise de dados. Após a obtenção das informações, são calculadas as tipologias de carga que representam cada cliente ou transformador, através de etapas de caracterização da carga. Os resultados obtidos permitem uma análise mais precisa do mercado de energia elétrica e, principalmente, o conhecimento da forma como cada classe de consumidores utiliza a rede. Este trabalho envolve parte do estudo mencionado sobre a análise dos dados coletados nas campanhas de medição, propondo e avaliando metodologias alternativas para duas etapas do processo de caracterização de tipologias de carga, a seleção de curvas típicas e a classificação de dados, adequadas às necessidades das revisões tarifárias e com base em métodos heurísticos e nas práticas do setor. Após o desenvolvimento e implementação das metodologias, foram realizados testes entre os processos propostos, comparando e avaliando suas particularidades para duas situações: a semelhança entre as tipologias encontradas para os transformadores e consumidores de um mesmo nível de tensão e o impacto nos custos marginais de capacidade. A análise das comparações realizadas permitiu a identificação dos impactos e características das metodologias desenvolvidas, para cada etapa estudada. / Knowing the way consumers use the energy is necessary for many studies, either commercial or technical. This knowledge can be reached by obtaining the load curves from all the customers of the company. However, given the great number of measurers necessary, this practice is not viable. The alternative used currently in tariff review in the Brazilian electrical system is based on the sampling theory associated with data analysis techniques. After obtaining the information, the load typologies that represent each transformer or customer are calculated through stages of load characterization. The results obtained allow a more precise analysis of the electric energy market and, specially, the knowledge of how each consumer class uses the electricity network. This research involves part of the previously mentioned study on the analysis of the data collected in the measurement campaigns, considering and evaluating alternative methodologies for two stages of the load typologies characterization process, the election of typical curves and the data classification, adjusted to the necessities of the tariff revisions and on the basis of heuristical methods and electricity sector practices. After the development and implementation of the methodologies, tests have been carried between the considered processes, comparing and evaluating their particularitities for two situations: the similarity between the typologies found for transformers and consumers on the same tension level and the impact in the marginal capacity costs. The analysis of the comparisons carried through allowed the identification of the impacts and characteristics of the developed methodologies, for each studied stage.

Este trabalho apresenta uma análise de comportamento de índices de carga relacionados ao uso e à atividade de memória. São descritos 11 índices que refletem direta ou indiretamente a carga de memória. Esses índices podem ser obtidos facilmente no sistema peracional GNU/Linux através do sistema de arquivos /proc. Uma ferramenta de monitoramento foi criada para facilitar a análise de comportamento, podendo também servir para fornecer informações de carga para políticas de escalonamento. Os valores de cada índice foram monitorados durante a execução de uma carga de trabalho composta por aplicações reais que utilizam altas quantidades de memória. A partir dos resultados é possível descobrir a utilidade de cada índice, indicando como eles podem ser usados para auxiliar políticas de escalonamento a avaliar a carga de memória de uma máquina. Métricas de avaliação de carga originárias da combinação de mais de um índice são descritas. Essas métricas foram criadas em casos em que a combinação de mais de um índice permitia representar a carga de memória com mais precisão do que índices usados isoladamente. As métricas e índices pesquisados proporcionam formas precisas de representar a carga de memória em vários níveis, desde níveis de baixa utilização até níveis de saturação da memória principal com sintomas de ocorrência de thrashing. / This work presents an analysis of the behavior of load indices related to memory usage and activity. It describes 11 indices which reflect memory load, directly or indirectly. These indices may be easily obtained on the GNU/Linux operating system using the /proc filesystem. A monitoring tool has been developed to make the behavior analysis easier, but it can also be employed to provide load information to scheduling policies. The values of each index have been monitored during the execution of a workload composed by real memory-intensive applications. From the monitoring results, it is possible to find out the usefulness of each index, pointing out how it may be used to help scheduling policies evaluate the memory load of a certain computer. Load evaluation metrics have been created combining more than one index, with the objective of characterizing memory load more precisely than just one isolated index. The explored metrics and indices have shown to provide precise forms of representing memory load at several levels, from low utilization levels up to excessive main memory usage with symptoms of thrashing.

A prova de carga dinâmica é freqüentemente utilizada na determinação da capacidade de carga de fundações por estacas cravadas e há relatos de uso com sucesso deste ensaio em estacas escavadas e tubulões. Esta pesquisa envolveu a adaptação e execução da prova de carga dinâmica na placa de aço circular de diâmetro 0,80 m, com o objetivo de inferir a capacidade de carga do sistema placa-solo. Como a prova de carga dinâmica permite que seja feita a comprovação da carga durante a cravação, vislumbra-se também a viabilização desse tipo de ensaio em solos porosos por meio da cravação da placa o necessário para atingir a capacidade de carga exigida em um projeto. Os ensaios foram realizados no campo experimental da USP/São Carlos, com solo superficial não saturado, poroso e colapsível, por isso foram feitas medidas dos valores de sucção matricial, já que esta exerce forte influência sobre a capacidade de carga / The dynamic load test is frequently used in the determination of driven piles foundation bearing capacity. It is also reported the successful use of the test in bored piles and caissons. This research included the adaptation and execution of the dynamic load test in circular steel plate, to verify the bearing capacity of footing foundations. Since the dynamic load tests allow the bearing capacity to be verified during the construction, it is also glimpsed the possibility of using this test in porous soils by penetrating the plate into the soil until the expected bearing capacity is achieved. The tests were held at the USP/São Carlos experimental foundation camp, which has superficial unsaturated, porous and colapsive soil, so matric suction's measurement were made, since it has strong influence on the bearing capacity

O evento de previsões do comportamento carga-recalque de uma estaca executada em solo predominantemente arenoso foi apresentado no 8° Seminário de Engenharia de Fundações Especiais e Geotecnia (SEFE8). As previsões utilizaram sondagens CPT, DMT e SPT realizadas no campo experimental de Araquari, em Santa Catarina. A estaca utilizada para o evento foi do tipo escavada com polímero, diâmetro de 100cm e comprimento de 24m. Foram recebidos pelo comitê organizador 73 previsões provenientes de 20 países, com estimativas do comportamento carga-recalque da estaca, da capacidade de carga total, lateral e de ponta e a distribuição de carga ao longo do fuste até a ruptura, definida pelo recalque de 100 mm (w/D = 10%), com um resumo dos métodos e considerações. Os dados das previsões foram comparados aos resultados obtidos em campo pela prova de carga estática da estaca instrumentada. As previsões foram majoritariamente conservadoras e o ensaio mais utilizado para determinação dos parâmetros do solo foi o CPT, tanto no meio acadêmico quanto no prático Diversos métodos foram utilizados, porém mesmo previsões que utilizaram o mesmo método apresentaram variabilidades nos resultados. Baixos valores de desvio na capacidade de carga total não significaram pequenos desvios de lateral e de ponta, mas uma combinação de desvios positivos e negativos desses. A maioria das estimativas subestimou a capacidade lateral e superestimou a de ponta. O método de Verbrugge (1981) foi utilizado em duas das cinco previsões com menores desvios de capacidade total. As curvas carga-recalque e carga-profundidade foram avaliadas quanto aos desvios médios absolutos e formatos, dados pela variância. As curvas carga-recalque com médias de até 10% utilizaram Elementos Finitos e o software UniPile, e o menor valor de variância utilizou Verbrugge (1981). As curvas carga-profundidade com médias de até 10% utilizaram Verbrugge (1981), Randolph e Wroth (1978) e Gwizdala e Steczniewski (2003), e o menor valor de variância utilizou o software UniPile. / The prediction event of load-settlement behavior of a pile built in predominantly sandy soil was presented at the 8th Foundation Engineering Seminar and Special Geotechnical (SEFE8). The predictions used tests of CPT, DMT and SPT accomplished in Araquari experimental field, in Santa Catarina. A bored pile with polymer, diameter of 100cm and length of 24m was the subject of the event. The organizing committee received 73 predictions from 20 countries, with estimates of load-settlement behavior of the pile, the total, shaft and base load capacity and the load distribution along the shaft until failure, defined by settlement of 100 mm (W/D = 10%), with a brief description of methods and considerations. Data from the predictions were compared to the results obtained in the field by static load test of the instrumented pile. The predictions were mostly conservative and the test most used for soil parameters prediction was the CPT, both in academia as in practice. Several methods were used, but even predictions that used the same method showed variability in the results Low error values in the total load capacity not meant small shaft and base errors, but a combination of positive and negative errors of these. Most estimates underestimated the shaft capacity and overestimated the base. The Verbrugge (1981) method was used in two of five predictions with lower errors of total capacity. The curves were analyzed for absolute average deviation and formats, evaluated by the variance. The load-settlement distribution with average up to 10% used Finite Element and UniPile software, and the lowest value of variance used Verbrugge (1981). The load-depth distribution with average up to 10% used Verbrugge (1981), Randolph and Wroth (1978) and Gwizdala and Steczniewski (2003), and the lowest value of variance used the UniPile software.

O perfil de consumo de energia elétrica dos consumidores necessita ser conhecido em detalhe para muitos estudos, sejam eles técnicos ou comerciais. Esse conhecimento pode ser alcançado através da obtenção das curvas de carga de todos os clientes da empresa, porém, devido ao grande número de medidores necessários, essa prática é inviável. A alternativa utilizada atualmente nas revisões tarifárias do sistema elétrico brasileiro emprega a teoria de amostragem associada a técnicas de análise de dados. Após a obtenção das informações, são calculadas as tipologias de carga que representam cada cliente ou transformador, através de etapas de caracterização da carga. Os resultados obtidos permitem uma análise mais precisa do mercado de energia elétrica e, principalmente, o conhecimento da forma como cada classe de consumidores utiliza a rede. Este trabalho envolve parte do estudo mencionado sobre a análise dos dados coletados nas campanhas de medição, propondo e avaliando metodologias alternativas para duas etapas do processo de caracterização de tipologias de carga, a seleção de curvas típicas e a classificação de dados, adequadas às necessidades das revisões tarifárias e com base em métodos heurísticos e nas práticas do setor. Após o desenvolvimento e implementação das metodologias, foram realizados testes entre os processos propostos, comparando e avaliando suas particularidades para duas situações: a semelhança entre as tipologias encontradas para os transformadores e consumidores de um mesmo nível de tensão e o impacto nos custos marginais de capacidade. A análise das comparações realizadas permitiu a identificação dos impactos e características das metodologias desenvolvidas, para cada etapa estudada. / Knowing the way consumers use the energy is necessary for many studies, either commercial or technical. This knowledge can be reached by obtaining the load curves from all the customers of the company. However, given the great number of measurers necessary, this practice is not viable. The alternative used currently in tariff review in the Brazilian electrical system is based on the sampling theory associated with data analysis techniques. After obtaining the information, the load typologies that represent each transformer or customer are calculated through stages of load characterization. The results obtained allow a more precise analysis of the electric energy market and, specially, the knowledge of how each consumer class uses the electricity network. This research involves part of the previously mentioned study on the analysis of the data collected in the measurement campaigns, considering and evaluating alternative methodologies for two stages of the load typologies characterization process, the election of typical curves and the data classification, adjusted to the necessities of the tariff revisions and on the basis of heuristical methods and electricity sector practices. After the development and implementation of the methodologies, tests have been carried between the considered processes, comparing and evaluating their particularitities for two situations: the similarity between the typologies found for transformers and consumers on the same tension level and the impact in the marginal capacity costs. The analysis of the comparisons carried through allowed the identification of the impacts and characteristics of the developed methodologies, for each studied stage.

The Long Term Bridge Performance (LTBP) Program is a 20-year program initiated by the Federal Highway Administration to better understand the behavior of highway bridges as they deteriorate due to environmental variables and vehicle loads. Part of this program includes the periodic testing of selected bridges. The Lambert Road Bridge was subjected to nondestructive testing in the fall of 2009. Part of this testing included a live load test. This test involved driving two heavy trucks across the instrumented bridge on selected load paths. The bridge was instrumented with strain, displacement, and tilt sensors. This collected data was used to calibrate a finite element model. This finite element model was used to determine the theoretical live load distribution factors. Using the controlling distribution factor from the finite element model, the inventory and operating ratings of the bridge were determined. These load ratings were compared to those obtained from using the controlling distribution factor from the AASHTO LRFD Specifications. This thesis also examined how different parameters such as span length, girder spacing, parapets, skew, continuity, deck overhang, and deck thickness affect the distribution factors of box girder bridges. This was done by creating approximately 40 finite element models and comparing the results to those obtained by using the AASHTO LRFD Specifications.