Curvature and velocity of methane-air Bunsen flame tips

PIV and photographic recording are used to measure the velocity of the fresh gas and the shape of the reaction layer in a region around the tip of a methane- air Bunsen flame attached to a cylindrical burner. The results compare well with numerical simulations carried out with an infinite activation energy reaction model. The experimental and numerical results confirm that the well-known linear relation between flame velocity and flame stretch derived from asymptotic theory for weakly curved and strained flames is valid for small and moderate values of the flame stretch if the modified definition of stretch introduced by Echekki and Mungal (Proc Combust Inst 23:455–461,1990) and Poinsot et al. (Combust Sci Technol 81:45–73,1992) is used. However, the relation between flame velocity and modified stretch ceases to be linear and approaches a square root law for large values of the stretch, when the curvature of the flame tip becomes large compared to the inverse of the thickness of a planar flame

Storm evolution characterization for analysing stone armour damage progression

Storm evolution is fundamental for analysing the damage progression of the different failure modes and establishing suitable protocols for maintaining and optimally sizing structures. However, this aspect has hardly been studied and practically the whole of the studies dealing with the subject adopt the Equivalent triangle storm. As against this approach, two new ones are proposed. The first is the Equivalent Triangle Magnitude Storm model (ETMS), whose base, the triangular storm duration, D, is established such that its magnitude (area describing the storm history above the reference threshold level which sets the storm condition),HT, equals the real storm magnitude. The other is the Equivalent Triangle Number of Waves Storm (ETNWS), where the base is referred in terms of the real storm's number of waves,Nz. Three approaches are used for estimating the mean period, Tm, associated to each of the sea states defining the storm evolution, which is necessary to determine the full energy flux withstood by the structure in the course of the extreme event. Two are based on the Jonswap spectrum representativity and the other uses the bivariate Gumbel copula (Hs, Tm), resulting from adjusting the storm peaks. The representativity of the approaches proposed and those defined in specialised literature are analysed by comparing the main armour layer's progressive loss of hydraulic stability caused by real storms and that relating to theoretical ones. An empirical maximum energy flux model is used for this purpose. The agreement between the empirical and theoretical results demonstrates that the representativity of the different approaches depends on the storm characteristics and point towards a need to investigate other geometrical shapes to characterise the storm evolution associated with sea states heavily influenced by swell wave components.

Storm characterization for analyzing stone armour damage progression

Storm evolution is fundamental for analysing the damage progression of the different failure modes and establishing suitable protocols for maintaining and optimally sizing structures. However, this aspect has hardly been studied and practically the whole of the studies dealing with the subject adopt the Equivalent triangle storm. As against this approach, two new ones are proposed. The first is the Equivalent Triangle Magnitude Storm model (ETMS), whose base, the triangular storm duration, D, is established such that its magnitude (area describing the storm history above the reference threshold level which sets the storm condition),HT, equals the real storm magnitude. The other is the Equivalent Triangle Number of Waves Storm (ETNWS), where the base is referred in terms of the real storm's number of waves,Nz. Three approaches are used for estimating the mean period, Tm, associated to each of the sea states defining the storm evolution, which is necessary to determine the full energy flux withstood by the structure in the course of the extreme event. Two are based on the Jonswap spectrum representativity and the other uses the bivariate Gumbel copula (Hs, Tm), resulting from adjusting the storm peaks. The representativity of the approaches proposed and those defined in specialised literature are analysed by comparing the main armour layer's progressive loss of hydraulic stability caused by real storms and that relating to theoretical ones. An empirical maximum energy flux model is used for this purpose. The agreement between the empirical and theoretical results demonstrates that the representativity of the different approaches depends on the storm characteristics and point towards a need to investigate other geometrical shapes to characterise the storm evolution associated with sea states heavily influenced by swell wave components.

Wireless communication enhancement methods for mobile robots in radiation environments

En entornos hostiles tales como aquellas instalaciones científicas donde la radiación ionizante es el principal peligro, el hecho de reducir las intervenciones humanas mediante el incremento de las operaciones robotizadas está siendo cada vez más de especial interés. CERN, la Organización Europea para la Investigación Nuclear, tiene alrededor de unos 50 km de superficie subterránea donde robots móviles controlador de forma remota podrían ayudar en su funcionamiento, por ejemplo, a la hora de llevar a cabo inspecciones remotas sobre radiación en los diferentes áreas destinados al efecto. No solo es preciso considerar que los robots deben ser capaces de recorrer largas distancias y operar durante largos periodos de tiempo, sino que deben saber desenvolverse en los correspondientes túneles subterráneos, tener en cuenta la presencia de campos electromagnéticos, radiación ionizante, etc. y finalmente, el hecho de que los robots no deben interrumpir el funcionamiento de los aceleradores. El hecho de disponer de un sistema de comunicaciones inalámbrico fiable y robusto es esencial para la correcta ejecución de las misiones que los robots deben afrontar y por supuesto, para evitar tales situaciones en las que es necesario la recuperación manual de los robots al agotarse su energía o al perder el enlace de comunicaciones. El objetivo de esta Tesis es proveer de las directrices y los medios necesarios para reducir el riesgo de fallo en la misión y maximizar las capacidades de los robots móviles inalámbricos los cuales disponen de almacenamiento finito de energía al trabajar en entornos peligrosos donde no se dispone de línea de vista directa. Para ello se proponen y muestran diferentes estrategias y métodos de comunicación inalámbrica. Teniendo esto en cuenta, se presentan a continuación los objetivos de investigación a seguir a lo largo de la Tesis: predecir la cobertura de comunicaciones antes y durante las misiones robotizadas; optimizar la capacidad de red inalámbrica de los robots móviles con respecto a su posición; y mejorar el rango operacional de esta clase de robots. Por su parte, las contribuciones a la Tesis se citan más abajo. El primer conjunto de contribuciones son métodos novedosos para predecir el consumo de energía y la autonomía en la comunicación antes y después de disponer de los robots en el entorno seleccionado. Esto es importante para proporcionar conciencia de la situación del robot y evitar fallos en la misión. El consumo de energía se predice usando una estrategia propuesta la cual usa modelos de consumo provenientes de diferentes componentes en un robot. La predicción para la cobertura de comunicaciones se desarrolla usando un nuevo filtro de RSS (Radio Signal Strength) y técnicas de estimación con la ayuda de Filtros de Kalman. El segundo conjunto de contribuciones son métodos para optimizar el rango de comunicaciones usando novedosas técnicas basadas en muestreo espacial que son robustas frente a ruidos de campos de detección y radio y que proporcionan redundancia. Se emplean métodos de diferencia central finitos para determinar los gradientes 2D RSS y se usa la movilidad del robot para optimizar el rango de comunicaciones y la capacidad de red. Este método también se valida con un caso de estudio centrado en la teleoperación háptica de robots móviles inalámbricos. La tercera contribución es un algoritmo robusto y estocástico descentralizado para la optimización de la posición al considerar múltiples robots autónomos usados principalmente para extender el rango de comunicaciones desde la estación de control al robot que está desarrollando la tarea. Todos los métodos y algoritmos propuestos se verifican y validan usando simulaciones y experimentos de campo con variedad de robots móviles disponibles en CERN. En resumen, esta Tesis ofrece métodos novedosos y demuestra su uso para: predecir RSS; optimizar la posición del robot; extender el rango de las comunicaciones inalámbricas; y mejorar las capacidades de red de los robots móviles inalámbricos para su uso en aplicaciones dentro de entornos peligrosos, que como ya se mencionó anteriormente, se destacan las instalaciones científicas con emisión de radiación ionizante. En otros términos, se ha desarrollado un conjunto de herramientas para mejorar, facilitar y hacer más seguras las misiones de los robots en entornos hostiles. Esta Tesis demuestra tanto en teoría como en práctica que los robots móviles pueden mejorar la calidad de las comunicaciones inalámbricas mediante la profundización en el estudio de su movilidad para optimizar dinámicamente sus posiciones y mantener conectividad incluso cuando no existe línea de vista. Los métodos desarrollados en la Tesis son especialmente adecuados para su fácil integración en robots móviles y pueden ser aplicados directamente en la capa de aplicación de la red inalámbrica. ABSTRACT In hostile environments such as in scientific facilities where ionising radiation is a dominant hazard, reducing human interventions by increasing robotic operations are desirable. CERN, the European Organization for Nuclear Research, has around 50 km of underground scientific facilities, where wireless mobile robots could help in the operation of the accelerator complex, e.g. in conducting remote inspections and radiation surveys in different areas. The main challenges to be considered here are not only that the robots should be able to go over long distances and operate for relatively long periods, but also the underground tunnel environment, the possible presence of electromagnetic fields, radiation effects, and the fact that the robots shall in no way interrupt the operation of the accelerators. Having a reliable and robust wireless communication system is essential for successful execution of such robotic missions and to avoid situations of manual recovery of the robots in the event that the robot runs out of energy or when the robot loses its communication link. The goal of this thesis is to provide means to reduce risk of mission failure and maximise mission capabilities of wireless mobile robots with finite energy storage capacity working in a radiation environment with non-line-of-sight (NLOS) communications by employing enhanced wireless communication methods. Towards this goal, the following research objectives are addressed in this thesis: predict the communication range before and during robotic missions; optimise and enhance wireless communication qualities of mobile robots by using robot mobility and employing multi-robot network. This thesis provides introductory information on the infrastructures where mobile robots will need to operate, the tasks to be carried out by mobile robots and the problems encountered in these environments. The reporting of research work carried out to improve wireless communication comprises an introduction to the relevant radio signal propagation theory and technology followed by explanation of the research in the following stages: An analysis of the wireless communication requirements for mobile robot for different tasks in a selection of CERN facilities; predictions of energy and communication autonomies (in terms of distance and time) to reduce risk of energy and communication related failures during missions; autonomous navigation of a mobile robot to find zone(s) of maximum radio signal strength to improve communication coverage area; and autonomous navigation of one or more mobile robots acting as mobile wireless relay (repeater) points in order to provide a tethered wireless connection to a teleoperated mobile robot carrying out inspection or radiation monitoring activities in a challenging radio environment. The specific contributions of this thesis are outlined below. The first sets of contributions are novel methods for predicting the energy autonomy and communication range(s) before and after deployment of the mobile robots in the intended environments. This is important in order to provide situational awareness and avoid mission failures. The energy consumption is predicted by using power consumption models of different components in a mobile robot. This energy prediction model will pave the way for choosing energy-efficient wireless communication strategies. The communication range prediction is performed using radio signal propagation models and applies radio signal strength (RSS) filtering and estimation techniques with the help of Kalman filters and Gaussian process models. The second set of contributions are methods to optimise the wireless communication qualities by using novel spatial sampling based techniques that are robust to sensing and radio field noises and provide redundancy features. Central finite difference (CFD) methods are employed to determine the 2-D RSS gradients and use robot mobility to optimise the communication quality and the network throughput. This method is also validated with a case study application involving superior haptic teleoperation of wireless mobile robots where an operator from a remote location can smoothly navigate a mobile robot in an environment with low-wireless signals. The third contribution is a robust stochastic position optimisation algorithm for multiple autonomous relay robots which are used for wireless tethering of radio signals and thereby to enhance the wireless communication qualities. All the proposed methods and algorithms are verified and validated using simulations and field experiments with a variety of mobile robots available at CERN. In summary, this thesis offers novel methods and demonstrates their use to predict energy autonomy and wireless communication range, optimise robots position to improve communication quality and enhance communication range and wireless network qualities of mobile robots for use in applications in hostile environmental characteristics such as scientific facilities emitting ionising radiations. In simpler terms, a set of tools are developed in this thesis for improving, easing and making safer robotic missions in hostile environments. This thesis validates both in theory and experiments that mobile robots can improve wireless communication quality by exploiting robots mobility to dynamically optimise their positions and maintain connectivity even when the (radio signal) environment possess non-line-of-sight characteristics. The methods developed in this thesis are well-suited for easier integration in mobile robots and can be applied directly at the application layer of the wireless network. The results of the proposed methods have outperformed other comparable state-of-the-art methods.

Técnicas de gamificación para la motivación de los estudiantes

El objetivo de este trabajo es desarrollar el módulo central para el futuro sistema web de la asignatura Procesadores de Lenguajes impartida en la Escuela Técnica Superior de Ingenieros Informáticos de la Universidad Politécnica de Madrid. Para dicho desarrollo se aplicarán técnicas de gamificación con el objetivo de mejorar el aprendizaje, subir la tasa de aprobados de la asignatura y despertar interés por parte del alumnado de la misma. Se modelizaron, diseñaron e implementaron una serie de funciones para el nombrado módulo central del proyecto, incluyendo partes de la interfaz gráfica. En el presente documento se ofrece una breve explicación en cuanto al tema de la gamificación y se presentan los requisitos de este módulo siguiendo el documento oficial del IEEE para la especificación de requisitos. Se ofrece también una explicación del proceso de diseño de dichas funcionalidades usando la metodología de software UWE (UML-based Web Engineering). Este sistema presenta varios modelos entre los que se encuentran el modelo de requisitos, modelo de contenido, modelo de navegación y modelo de presentación de los elementos del sistema. Se espera que gracias a este proyecto el alumno se vea más involucrado en la asignatura, a la vez que aumenta su interés sobre dicha materia.---ABSTRACT---The objective of this document is to explain how the work in the central module of a web system has been done. This web system is a platform for the subject Procesadores de Lenguajes which is taught at Escuela Técnica Superior de Ingenieros Informáticos of the Universidad Politécnica de Madrid. Gamification techniques are included in this project with the purpose to improve learning, to increase pass rates and to get students more engaged with the subject. Functions for the central node of this project were analyzed, designed and implemented, including the graphic interface. The present document offers a brief explanation about gamification and presents the system requirements, which were created following the official document for Requirements Specificication by IEEE. It also offers a detailed explanation of the design process using UWE methodology (UML-based Web Engineering). This methodology presents a requirement model, content model, navigation model and presentation model of the elements of the system. We expect that by using this system, students will become more interested in learning, as well as more engaged in the process, resulting in a continuous progress during the course.

Procedimiento multicriterio-multiobjetivo de planificación energética a comunidades rurales aisladas

La toma de decisiones en el sector energético se torna compleja frente a las disímiles opciones y objetivos a cumplir. Para minimizar esta complejidad, se han venido desarrollando una gama amplia de métodos de apoyo a la toma de decisiones en proyectos energéticos. En la última década, las energización de comunidades rurales aisladas ha venido siendo prioridad de muchos gobiernos para mitigar las migraciones del campo para la ciudad. Para la toma de decisiones en los proyectos energéticos de comunidades rurales aisladas se necesitan proyectar la influencia que estos tendrás sobre los costes económicos, medioambientales y sociales. Es por esta razón que el presente trabajo tuvo como objetivo diseñar un modelo original denominado Generación Energética Autóctona Y Limpia (GEAYL) aplicado a una comunidad rural aislada de la provincia de Granma en Cuba. Este modelo parte dos modelos que le preceden el PAMER y el SEMA. El modelo GEAYL constituye un procedimiento multicriterio-multiobjetivo de apoyo a la planificación energética para este contexto. Se plantearon cinco funciones objetivos: F1, para la minimización de los costes energéticos; F2 para la minimización de las emisiones de CO2, F3, para la minimización de las emisiones de NOx; F4, para la minimización de las emisiones de SOx (cuyos coeficientes fueron obtenidos a través de la literatura especializada) y F5, para la maximización de la Aceptación Social de la Energía. La función F5 y la manera de obtener sus coeficientes constituye la novedad del presente trabajo. Estos coeficientes se determinaron aplicando el método AHP (Proceso Analítico Jerárquico) con los datos de partidas derivados de una encuesta a los usuarios finales de la energía y a expertos. Para determinar el suministro óptimo de energía se emplearon varios métodos: la suma ponderada, el producto ponderado, las distancias de Manhattan L1, la distancia Euclidea L2 y la distancia L3. Para estas métricas se aplicaron distintos vectores de pesos para determinar las distintas estructuras de preferencias de los decisores. Finalmente, se concluyó que tener en consideración a Aceptación Social de la Energía como una función del modelo influye en el suministro de energía de cada alternativa energética. ABSTRACT Energy planning decision making is a complex task due to the multiple options to follow and objectives to meet. In order to minimize this complexity, a wide variety of methods and supporting tools have been designed. Over the last decade, rural energization has been a priority for many governments, aiming to alleviate rural to urban migration. Rural energy planning decision making must rely on financial, environmental and social costs. The purpose of this work is to define an original energy planning model named Clean and Native Energy Generation (Generación Energética Autóctona Y Limpia, GEAYL), and carry out a case study on Granma Province, Cuba. This model is based on two previous models: PAMER & SEMA. GEAYL is a multiobjective-multicriteria energy planning model, which includes five functions to be optimized: F1, to minimize financial costs; F2, to minimize CO2 emissions; F3, to minimize NOx emissions; F4, to minimize SOx emissions; and F5, to maximize energy Social Acceptability. The coefficients corresponding to the first four functions have been obtained through specialized papers and official data, and the ones belonging to F5 through an Analytic Hierarchy Process (AHP), built as per a statistical enquiry carried out on energy users and experts. F5 and the AHP application are considered to be the novelty of this model. In order to establish the optimal energy supply, several methods have been applied: weighted sum, weighted product, Manhattan distance L1, Euclidean distance L2 and L3. Several weight vectors have been applied to the mentioned distances in order to conclude the decision makers potential preference structure. Among the conclusions of this work, it must be noted that function F5, Social Acceptability, has a clear influence on every energy supply alternative.

Flexibility of the Kir6.2 inward rectifier K+ channel pore

Interactions of sulfhydryl reagents with introduced cysteines in the pore-forming (Kir6.2) subunits of the KATP channel were examined. 2-Aminoethyl methanethiosulfonate (MTSEA+) failed to modify Cd2+-insensitive control-Kir6.2 channels, but rapidly and irreversibly modified Kir6.2[L164C] (L164C) channels. Although a single Cd2+ ion is coordinated by L164C, four MTSEA+ “hits” can occur, each sequentially reducing the single-channel current. A dimeric fusion of control-Kir6.2 and L164C subunits generates Cd2+-insensitive channels, confirming that at least three cysteines are required for coordination, but MTSEA+ modification of the dimer occurs in two hits. L164C channels were not modified by bromotrimethyl ammoniumbimane (qBBr+), even though qBBr+ caused voltage-dependent block (as opposed to modification) that was comparable to that of MTSEA+ or 3-(triethylammonium)propyl methanethiosulfonate (MTSPTrEA+), implying that qBBr+ can also enter the inner cavity but does not modify L164C residues. The Kir channel pore structure was modeled by homology with the KcsA crystal structure. A stable conformation optimally places the four L164C side chains for coordination of a single Cd2+ ion. Modification of these cysteines by up to four MTSEA+ (or three MTSPTrEA+, or two qBBr+) does not require widening of the cavity to accommodate the derivatives within it. However, like the KcsA crystal structure, the energy-minimized model shows a narrowing at the inner entrance, and in the Kir6.2 model this narrowing excludes all ions. To allow entry of ions as large as MTSPTrEA+ or qBBr+, the entrance must widen to >8 Å, but this widening is readily accomplished by minimal M2 helix motion and side-chain rearrangement.

Análise da composição, abundância e distribuição da comunidade fitoplanctônica nos reservatórios do sistema em cascata do Médio e Baixo rio Tietê/SP

Com a finalidade de atender a demanda energética, muitos reservatórios foram construídos no Brasil e, notadamente na região Sudeste, as construções das barragens não somente atenderam aos usos múltiplos (geração de energia, irrigação, lazer e abastecimento público), como também foram elementos propulsores da economia regional, contribuindo para a expansão das atividades industriais e rurais, bem como, um desordenado crescimento urbano. Em conseqüência da falta de planejamento, áreas naturais foram desmatadas, sendo substituídas por formas de plantio inadequadas e por projetos de especulação imobiliária não condizentes com a sustentabilidade ambiental. No decorrer das últimas décadas, os impactos aumentaram em magnitude e extensão, ocasionando sérios problemas aos recursos hídricos, culminando em conflitos pelo uso da água. Dentro deste contexto, destaca-se o rio Tietê, o qual percorre importantes cidades e extensas áreas rurais no Estado de São Paulo, sendo que, neste longo percurso, recebe a contribuição de diversos tributários (poluídos ou não) e efluentes urbanos, industriais e aqueles derivados de fontes não pontuais, além do processo de fragmentação que foi instalado a partir da construção de inúmeras barragens. De forma conjunta, todos os fatores promoveram alterações significativas no sistema e, procurando avaliar a situação atual dos reservatórios, desenvolveu-se uma pesquisa direcionada à análise da composição, densidade e distribuição da comunidade fitoplanctônica e sua relação com as variáveis limnológicas, climatológicas e hidrodinâmicas dos reservatórios da Barra Bonita, Bariri, Ibitinga, Promissão, Nova Avanhandava, Três Irmãos, além dos rios Tietê e Piracicaba e parte do rio Paraná (reservatório de Jupiá e a Jusante do reservatório de Ilha Solteira). Para tanto, foram realizadas coletas nos meses de fevereiro, maio, julho e outubro de 2000 e os resultados obtidos demonstram uma elevada concentração de nutrientes, com redução na seqüência dos reservatórios, além da variabilidade temporal, com efeito significativo da precipitação no transporte de materiais, promovendo alterações no estado trófico de cada sistema. A disponibilidade de nutrientes, transparência da água, vazão e tempo de residência, associados aos fatores climatológicos, foram elementos importantes no estabelecimento das populações, influenciando a composição, densidade e distribuição da comunidade fitoplanctônica, a qual apresentou maior dominância das classes Cyanophyceae e Chlorophyceae, com maior contribuição em densidade e riqueza de espécies, respectivamente.

Desempenho econômico de um sistema de produção de biomassa da cana energia

O uso da biomassa como fonte de energia elétrica corresponde a uma alternativa de grande importância para o planejamento estratégico do crescimento econômico de diversos países. A vasta extensão territorial e o clima favorável ao desenvolvimento da agricultura no Brasil trazem como vantagem o poder de planejar sua matriz energética utilizando variadas fontes primárias renováveis. A cana-de-açúcar destaca-se pela rusticidade e grande produtividade. O bagaço como um subproduto resultante do processamento da cana é utilizado como fonte para a cogeração de energia e pode contribuir significativamente para a descentralização das fontes de energia nacional. Com o desenvolvimento da tecnologia de etanol de segunda geração, a busca pela maior produção de biomassa ganha relevância. Os programas de melhoramento identificaram que se caso com redução de 25 a 35% da sacarose na cana, a planta teria um potencial de aumento de mais de 100% da biomassa. Os híbridos derivados de programas de melhoramento da espécie Saccharum spp., direcionados exclusivamente para a produção de biomassa, foram denominados de cana energia. Tendo em vista o potencial de produtividade da cultura e consequentemente de geração de energia, torna-se necessário conhecer se esse potencial se traduz em resultado econômico. Com esse enfoque, o objetivo deste trabalho foi analisar a viabilidade econômica da produção de biomassa da cana energia. Para tanto foi desenvolvido um modelo em planilha eletrônica e o modelo foi empregado na simulação de cenários e alternativas. A planilha integra modelos de balanço hídrico, produtividade da cultura e distribuição de chuvas, e suas relações com aspectos econômicos e produtivos. O preço de venda da biomassa, a produtividade da cultura e a distância de transporte se mostraram como os itens que mais influem sobre os indicadores de viabilidade econômica. Diferentemente da eficiência gerencial, a eficiência de campo corresponde a um fator de grande importância a ser considerado para reduzir o custo de produção. A análise da área de colheita como uma variável crítica indicou que existem módulos ideais para a utilização de máquinas agrícolas, reduzindo o seu custo operacional devido ao uso melhor atribuído das máquinas na propriedade. A análise da textura do solo como variável crítica mostrou que o cultivo da planta em diferentes tipos de solos reflete em diferentes custos operacionais, produtividade potencial e no montante de investimento. O ano de reforma corresponde a um fator crítico para a viabilização da atividade. Para o cenário base, o indicador de atratividade financeira apresenta um Valor Presente Líquido de 6,4 milhões de reais e uma Taxa Interna de Retorno de 15,2%, com um horizonte de 20 anos de produção. As análises de sensibilidade mostram que as variáveis que mais impactam nos indicadores de viabilidade econômica financeira são o preço de venda da biomassa e a produtividade média da lavoura.

Desenvolvimento de algoritmo de controle de tração para regeneração de energia metroviária - ACTREM: melhoria da eficiência energética de sistemas de tração metroviária.

Esta tese propõe um modelo de regeneração de energia metroviária, baseado no controle de paradas e partidas do trem ao longo de sua viagem, com o aproveitamento da energia proveniente da frenagem regenerativa no sistema de tração. O objetivo é otimizar o consumo de energia, promover maior eficiência, na perspectiva de uma gestão sustentável. Aplicando o Algoritmo Genético (GA) para obter a melhor configuração de tráfego dos trens, a pesquisa desenvolve e testa o Algoritmo de Controle de Tração para Regeneração de Energia Metroviária (ACTREM), usando a Linguagem de programação C++. Para analisar o desempenho do algoritmo de controle ACTREM no aumento da eficiência energética, foram realizadas quinze simulações da aplicação do ACTREM na linha 4 - Amarela do metrô da cidade de São Paulo. Essas simulações demonstraram a eficiência do ACTREM para gerar, automaticamente, os diagramas horários otimizados para uma economia de energia nos sistemas metroviários, levando em consideração as restrições operacionais do sistema, como capacidade máxima de cada trem, tempo total de espera, tempo total de viagem e intervalo entre trens. Os resultados mostram que o algoritmo proposto pode economizar 9,5% da energia e não provocar impactos relevantes na capacidade de transporte de passageiros do sistema. Ainda sugerem possíveis continuidades de estudos.

All-optical OFDM and distributed Raman amplification : challenges to enable high capacities and extend reach

We review recent advances in all-optical OFDM technologies and discuss the performance of a field trial of a 2 Tbit/s Coherent WDM over 124 km with distributed Raman amplification. The results indicate that careful optimisation of the Raman pumps is essential. We also consider how all-optical OFDM systems perform favourably against energy consumption when compared with alternative coherent detection schemes. We argue that, in an energy constrained high-capacity transmission system, direct detected all-optical OFDM with `ideal' Raman amplification is an attractive candidate for metro area datacentre interconnects with ~100 km fibre spans, with an overall energy requirement at least three times lower than coherent detection techniques.

Supply chain optimisation of pyrolysis plant deployment using goal programming

This paper presents a goal programming model to optimise the deployment of pyrolysis plants in Punjab, India. Punjab has an abundance of waste straw and pyrolysis can convert this waste into alternative bio-fuels, which will facilitate the provision of valuable energy services and reduce open field burning. A goal programming model is outlined and demonstrated in two case study applications: small scale operations in villages and large scale deployment across Punjab's districts. To design the supply chain, optimal decisions for location, size and number of plants, downstream energy applications and feedstocks processed are simultaneously made based on stakeholder requirements for capital cost, payback period and production cost of bio-oil and electricity. The model comprises quantitative data obtained from primary research and qualitative data gathered from farmers and potential investors. The Punjab district of Fatehgarh Sahib is found to be the ideal location to initially utilise pyrolysis technology. We conclude that goal programming is an improved method over more conventional methods used in the literature for project planning in the field of bio-energy. The model and findings developed from this study will be particularly valuable to investors, plant developers and municipalities interested in waste to energy in India and elsewhere. © 2014 Elsevier Ltd. All rights reserved.

All-optical OFDM and distributed Raman amplification:challenges to enable high capacities and extend reach

We review recent advances in all-optical OFDM technologies and discuss the performance of a field trial of a 2 Tbit/s Coherent WDM over 124 km with distributed Raman amplification. The results indicate that careful optimisation of the Raman pumps is essential. We also consider how all-optical OFDM systems perform favourably against energy consumption when compared with alternative coherent detection schemes. We argue that, in an energy constrained high-capacity transmission system, direct detected all-optical OFDM with `ideal' Raman amplification is an attractive candidate for metro area datacentre interconnects with ~100 km fibre spans, with an overall energy requirement at least three times lower than coherent detection techniques.

Solar pond powered liquid desiccant evaporative cooling

Liquid desiccant cooling systems (LDCS) are energy efficient means of providing cooling, especially when powered by low-grade thermal sources. In this paper, the underlying principles of operation of desiccant cooling systems are examined, and the main components (dehumidifier, evaporative cooler and regenerator) of the LDCS are reviewed. The evaporative cooler can take the form of direct, indirect or semi-indirect. Relative to the direct type, the indirect type is generally less effective. Nonetheless, a certain variant of the indirect type - namely dew-point evaporative cooler - is found to be the most effective amongst all. The dehumidifier and the regenerator can be of the same type of equipment: packed tower and falling film are popular choices, especially when fitted with an internal heat exchanger. The energy requirement of the regenerator can be supplied from solar thermal collectors, of which a solar pond is an interesting option especially when a large scale or storage capability is desired.

Análise da formulação em Monte Carlo dos pacotes de energia multiespectrais aplicada a meios constituídos por vapor d'água

The Monte Carlo method is accurate and is relatively simple to implement for the solution of problems involving complex geometries and anisotropic scattering of radiation as compared with other numerical techniques. In addition, differently of what happens for most of numerical techniques, for which the associated simulations computational time tends to increase exponentially with the complexity of the problems, in the Monte Carlo the increase of the computational time tends to be linear. Nevertheless, the Monte Carlo solution is highly computer time consuming for most of the interest problems. The Multispectral Energy Bundle model allows the reduction of the computational time associated to the Monte Carlo solution. The referred model is here analyzed for applications in media constituted for nonparticipating species and water vapor, which is an important emitting species formed during the combustion of hydrocarbon fuels. Aspects related to computer time optimization are investigated the model solutions are compared with benchmark line-by-line solutions