Desde que foi introduzida por Tswett no começo do século XX, a cromatografia vem sofrendo contínuos avanços. Entretanto, a miniaturização da cromatografia líquida, apesar de seu inicio promissor, ainda continua bastante lenta e até o presente não alcançou ampla difusão, sendo que o número de grupos trabalhando nesta área é ainda bastante restrito. O motivo deste lento avanço se encontrava na dificuldade em se desenvolver equipamentos adequados, colunas apropriadas e sistemas de tratamento de dados suficientemente rápidos para os sistemas miniaturizados. Apesar de muitos desses problemas atualmente serem de fácil resolução, ainda não se dispõe de equipamentos comercialmente disponíveis que supram satisfatoriamente às condições impostas pelas micro-colunas. Tal carência deve ser suprida antes de nos beneficiarmos de todas as vantagens intrínsecas à miniaturização da cromatografia líquida. Deste modo, o presente projeto visa o desenvolvimento de instrumentação totalmente dedicada aos sistemas miniaturizados de cromatografia líquida incluindo o desenvolvimento de uma bomba de alta pressão, um sistema de injeção a base de tempo, um forno capaz de realizar programação de temperatura e o software de controle dos mesmos. Os equipamentos desenvolvidos foram então aplicados em separações de estatinas demonstrando um excelente desempenho. / Since the chromatography was introduced by Tswett, in the beginning of the 20th century, the technique has suffered a constant progress. However, the miniaturization of liquid chromatography, instead of its promising start, it is still too slow and this technique has not reached a wide divulgation so far. It is important to mention that the number of groups working in this area is very limited yet. The reason of this slow progress was due to the difficulty in developing suitable equipments, appropriated columns and data treatment systems that are quick enough for the miniaturized systems. Currently, many of these problems are easy to be solved, however, there are no equipments available commercially that supply the conditions imposed by microcolumns satisfactorily. Such lack should be filled before benefiting from all the advantages concerned to the miniaturization of liquid chromatography. In this way, this study aims at the development of instrumentation totally dedicated to the miniaturized systems of liquid chromatography, including the development of a high pressure pump, an time-based injector, an oven that sets the temperature programming and the software that can control all these devices. The developed equipments were then applied in the separation of statins, demonstrating an excellent performance.

It is important to develop methods that are capable of successfully determining plant performance. The method used should be based on the ability to determine the performance of each of the various unit operations within the plant. This in turn will assist with the correct decision as to which unit in the plant should be improved first. The performance of the various units can be accumulated to give a representation of the performance of the entire plant. A plant-wide performance monitoring method has been developed to do just this. Originally it was developed for a specific unit operation. It has now been verified that this method is applicable to different unit operations. The method employed to determine this plant-wide performance is by evaluating how close the plant is to its inherent optimum. Where applicable, this inherent optimum can also be replaced with a user specified optimum. When an optimum is specified there is a possibility of oscillations around this “optimum” and the effects of this on the performance number are eliminated to give a more general plant-wide performance number for each unit operation. In addition to the “optimum” value selection the addition of performance weights to specific focus areas (utility usage or product quality) in the performance calculation will also improve the comparative nature of the plant-wide index for different unit operations. The scope of this investigation is limited to the experimental test rigs that were available in the Process Control Laboratory at the University of Pretoria. The methods that were used to determine the single loop performance of each of the different control loops are: <ul> <li>Minimum variance</li> <li>Generalised minimum variance</li> <li>Integral of the Absolute Error (IAE)</li> <li>Integral of the Square Error (ISE)</li> </ul> The single loop performance methods are required to determine how effectively the plant-wide performance index evaluates the plant, since these are existing means of determining how well a plant is operating, but these become impractical due to excessive amounts of information needing evaluation. / Dissertation (MEng)--University of Pretoria, 2008. / Chemical Engineering / unrestricted

Traffic simulation is a safe and efficient tool to investigate infrastructural changes as well as traffic conditions. This master thesis aims to analyse a microscopic traffic simulation method for evaluation of bus terminal capacity. The evaluation is performed by investigating a case study of the bus terminal at Norrköping travel centre. The analysed method, referred to as terminal logic in the thesis, uses a combination of time based and event based simulation. Through the combination of time and event, it is possible to capture all movements within the terminal for individual vehicles. The simulation model is built in the software Vissim. A new travel centre for Norrköping is under development. Among the reasons for a new travel centre is the railway project Ostlänken in the eastern part of Sweden. An evaluation of the bus terminal is interesting due to a suspicion of overcapacity and the opportunity of redesigning. To investigate both the terminal capacity and the terminal logic, three scenarios were implemented. Scenario 1: Current design and frequency Scenario 2: Current design with higher frequency Scenario 3: Decreased number of bus stops with current frequency The results from the scenarios confirm the assumption of overcapacity. The capacity was evaluated based on several different measures, all indicating a low utilization. Even so, the utilization was uneven over time and congestion could still occur when several buses departed at the same time. This was also seen when studying the simulation, which showed congestions when several buses departed at the same time. The case study established the terminal logic to be useful when evaluating capacity at bus terminals. It provides a good understanding of how the terminal operates and captures the movements. However, it was time-consuming to adjust the logic to the studied terminal. This is a disadvantage when investigating more than one alternative. The thesis resulted in two main conclusions. Firstly, a more optimised planning of the buses at Norrköping bus terminal would probably be achievable and lead to less congestions at the exits. Secondly, the terminal logic is a good method to use when evaluating bus terminals but it is not straight forward to implement.

Different key performance indicators are used to assess various aspects of a wind turbine (performance, reliability, financial aspects…). Availability metrics mainly, time-based and energy-based availability are the main indicators used to monitor and evaluate turbine’s availability performance today. However, due to significant growth of the share of energy sold into the electricity market as well as different selling structures, a new indicator has been established in order to assess availability performance in terms of revenues rather than time or energy.  This thesis compares energy and revenue-based availabilities of two turbines during 12 months of operational production. A methodology of calculation is suggested based on the International Electrotechnical Commission (IEC) information model for availability calculation. Time-based availability is calculated first, followed by energy-based, and finally revenue-based availability is derived from revenues as a result of combining energy production and electricity prices and revenue losses from energy losses and electricity prices. Availability metrics are calculated for three different scenarios, pure-market, mix of market and fixed price purchase agreement (PPA), and finally a PPA with a minimum monthly baseload to simulate the impact of volume risk. Results indicate a significant impact caused by the electricity price as well as the specifics of the selling agreement on revenue-based availability. Finding that in such cases, a significant divergence between energy and revenue-based indicators is possible. Limitations associated with the suggested methodology and case studies are presented and discussed.

Half in Dream: The Tangle in the Grid discusses the form and content of a physical art installation by the same name. The site-specific installation is a large three-dimensional collage of natural ephemera collected from the area around Amherst, Massachusetts, which interacts with natural lighting conditions to illuminate a gallery-facing image of ever-moving light and shadow. The written work elaborates some of the many details within the structure of the artwork, and reveals the philosophies, embodied practices, and methodologies that informed the visual work's creation. Woven throughout are reflections on phenomenology, walking practice, General Systems Theory, collective making, narrative arts, Zen Buddhist practice, indigenous perspectives, and ecological theory.

I created the term Neo-Raconteur to convey my interest in medium theory to support the artistic custom of revealing cultural conventions for allocation into artistic genres. The term evolved from the French word "Raconteur," meaning: somebody who tells stories or anecdotes in an interesting or entertaining way. In the past a Raconteur's anecdotes were verbally volleyed, ever voluble, yet quip. Neo-Raconteurs may decide not to speak at all choosing their anecdotal expression to manifest itself through singular or multiple means, manners, or methods of design and technology as well as or involving more traditional techniques of extraction to convey the narrative. I demonstrate how it applies to my work in time-based-media within the realms of Southern Gothic symbolism -- which rely on the supernatural, physical geographic settings, instances of the grotesque and irony along with visual and/or psychological shadow(s) of foreboding caused by tradition or hidden truths, occasionally both.

Examensarbetet genomfördes på AstraZeneca, Snäckviken hos fabriken API. Dess ångsystem har länge drabbats av oavsiktliga avbrott och detta har inte åtgärdats trots förebyggande insatser, vilket i sin tur har resulterat i produktionsbortfall. Syftet med denna studie är därmed att ta fram en långsiktig underhållsplan på komponentnivå som ska minska samtliga avbrott i ångsystemet. För att genomföra detta var det nödvändigt med litteraturstudier, avbrottanalys, nulägesanalys, besök på Snäckviken samt intervjuer. Studiens teoriavsnitt omfattades bland annat av väsentliga begrepp såsom underhåll, tidsbaserat- och tillståndsbaserat underhåll. Dessa termer bidrog till förståelsen av arbetet och framtagningen av resultatet och i sin tur även diskussionen. Det slutliga resultatet påvisade faktumet att det fanns tre komponenter som orsakade flest avbrott i systemet, och för en av dessa skapades det en underhållsplan. Planen omfattas av en underhållsbeskrivning, reservdelar/utbyteskomponenter, tidsutförande samt underhållsreperationer som inkluderar rekommenderad utförarkompetens. / The project was carried out at AstraZeneca, Snäckviken at the API factory. Its steam system has long been affected by unintentional interruptions and this has not been remedied despite preventive measures, which in turn has resulted in production losses. The purpose of this study is therefore to develop a long-term maintenance plan at component level that will reduce all interruptions in the steam system. To implement this, it was necessary with literature studies, current situation analysis, interruption analysis, visits to Snäckviken and interviews. The theoretical section of the study included, among other things, essential concepts such as maintenance, time-based- and condition-based maintenance. These terms contributed to the understanding of the study and the result, and in turn also the discussion. The result demonstrated the fact that there were three components that caused the most interruptions in the steam system, and for one of these a maintenance plan was created. The plan is covered by a maintenance description, spare parts / replacement

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