Superheroes or Group of Heroes? : The Avengers as Multiple Protagonist Superhero Cinema

Heroes have often been thought of as singular individuals standing apart from the rest of the world, and the current superheroes are no exception. Even though their comic book counterparts exist in complex social networks of supporting characters and related colorful heroes, cinematic adaptations often “kowtow” to single-hero worship (Burke 2008, 101), isolating the hero from a larger narrative world and networks of characters. This changed with the success The Avengers in. This film and series which it was a part of – The Marvel Cinematic Universe - quickly became a trendsetter within the larger media landscape. In this article, I present a close formal analysis of The Avengers and contextualize it within the larger narrative of the cinematic universe. I argue that the film belongs to the genre of multiple protagonist cinema, yet in a form that straddles the line between the two usual variations of that form of cinema. Multiple protagonist cinema is usually either a form often reserved for non-mainstream, experimental narratives in one extreme or it is just a slight variation on pre-existing mainstream Hollywood formulas in the other extreme. The Avengers finds middle ground between these extremes, and manages to do so with special consideration to the superhero genre

Aportes de soft computing en las energías renovables eólicas

La Soft Computing es un conjunto de metodologías que fundamentalmente sirve para resolver problemas provenientes de situaciones inciertas, imprecisas, y otras situaciones en las que con las metodologías clásicas no se pueden abordar, por su dificultad en su representación y modelación así como por su complejidad. En la generación de la energía eólica se presentan diversas situaciones complejas de naturaleza incierta e imprecisa, que han necesitado y necesitan el uso de la soft computing. En este ensayo se hace la recopilación de los artículos publicados en los que se resuelve los problemas asociados con las energías eólicas utlizando las metodologías soft computing. Se ha encontrado gran número de trabajos que utilizan las metodologías fuzzy, redes neuronales artificiales y algoritmos genéticos; escasos trabajos que utilizan los métodos híbridos y ningunos los recientes métodos de búsqueda y relajación.    Palabras clave: Soft computing,  energía eólica

Sustainable aviation electrification: a comprehensive review of electric propulsion system architectures, energy management, and control

The civil aviation sector plays an increasingly significant role in transportation sustainability in the environmental, economic, and social dimensions. Driven by the concerns of sustainability in the aviation sector, more electrified aircraft propulsion technologies have emerged and form a very promising approach to future sustainable and decarbonized aviation. This review paper aims to provide a comprehensive and broad-scope survey of the recent progress and development trends in sustainable aviation electrification. Firstly, the architectures of electrified aircraft propulsion are presented with a detailed analysis of the benefits, challenges, and studies/applications to date. Then, the challenges and technical barriers of electrified aircraft propulsion control system design are discussed, followed by a summary of the control methods frequently used in aircraft propulsion systems. Next, the mainstream energy management strategies are investigated and further utilized to minimize the block fuel burn, emissions, and economic cost. Finally, an overview of the development trends of aviation electrification is provided

Optimization approaches for exploiting the load flexibility of electric heating devices in smart grids

Energy systems all over the world are undergoing a fundamental transition to tackle climate change and other environmental challenges. The share of electricity generated by renewable energy sources has been steadily increasing. In order to cope with the intermittent nature of renewable energy sources, like photovoltaic systems and wind turbines, the electrical demand has to be adjusted to their power generation. To this end, flexible electrical loads are necessary. Moreover, optimization approaches and advanced information and communication technology can help to transform the traditional electricity grid into a smart grid. To shift the electricity consumption in time, electric heating devices, such as heat pumps or electric water heaters, provide significant flexibility. In order to exploit this flexibility, optimization approaches for controlling flexible devices are essential. Most studies in the literature use centralized optimization or uncoordinated decentralized optimization. Centralized optimization has crucial drawbacks regarding computational complexity, privacy, and robustness, but uncoordinated decentralized optimization leads to suboptimal results. In this thesis, coordinated decentralized and hybrid optimization approaches with low computational requirements are developed for exploiting the flexibility of electric heating devices. An essential feature of all developed methods is that they preserve the privacy of the residents. This cumulative thesis comprises four papers that introduce different types of optimization approaches. In Paper A, rule-based heuristic control algorithms for modulating electric heating devices are developed that minimize the heating costs of a residential area. Moreover, control algorithms for minimizing surplus energy that otherwise could be curtailed are introduced. They increase the self-consumption rate of locally generated electricity from photovoltaics. The heuristic control algorithms use a privacy-preserving control and communication architecture that combines centralized and decentralized control approaches. Compared to a conventional control strategy, the results of simulations show cost reductions of between 4.1% and 13.3% and reductions of between 38.3% and 52.6% regarding the surplus energy. Paper B introduces two novel coordinating decentralized optimization approaches for scheduling-based optimization. A comparison with different decentralized optimization approaches from the literature shows that the developed methods, on average, lead to 10% less surplus energy. Further, an optimization procedure is defined that generates a diverse solution pool for the problem of maximizing the self-consumption rate of locally generated renewable energy. This solution pool is needed for the coordination mechanisms of several decentralized optimization approaches. Combining the decentralized optimization approaches with the defined procedure to generate diverse solution pools, on average, leads to 100 kWh (16.5%) less surplus energy per day for a simulated residential area with 90 buildings. In Paper C, another decentralized optimization approach that aims to minimize surplus energy and reduce the peak load in a local grid is developed. Moreover, two methods that distribute a central wind power profile to the different buildings of a residential area are introduced. Compared to the approaches from the literature, the novel decentralized optimization approach leads to improvements of between 0.8% and 13.3% regarding the surplus energy and the peak load. Paper D introduces uncertainty handling control algorithms for modulating electricheating devices. The algorithms can help centralized and decentralized scheduling-based optimization approaches to react to erroneous predictions of demand and generation. The analysis shows that the developed methods avoid violations of the residents\u27 comfort limits and increase the self-consumption rate of electricity generated by photovoltaic systems. All introduced optimization approaches yield a good trade-off between runtime and the quality of the results. Further, they respect the privacy of residents, lead to better utilization of renewable energy, and stabilize the grid. Hence, the developed optimization approaches can help future energy systems to cope with the high share of intermittent renewable energy sources

Techno-Economic modelling of hybrid renewable mini-grids for rural electrification planning in Sub-Saharan Africa

Access to clean, modern energy services is a necessity for sustainable development. The UN Sustainable Development Goals and SE4ALL program commit to the provision of universal access to modern energy services by 2030. However, the latest available figures estimate that 1.1 billion people are living without access to electricity, with over 55% living in Sub-Saharan Africa. Furthermore, 85% live in rural areas, often with challenging terrain, low income and population density; or in countries with severe underinvestment in electricity infrastructure making grid extension unrealistic. Recently, improvements in technology, cost efficiency and new business models have made mini-grids which combine multiple energy technologies in hybrid systems one of the most promising alternatives for electrification off the grid. The International Energy Agency has estimated that up to 350,000 new mini-grids will be required to reach universal access goals by 2030. Given the intermittent and location-dependent nature of renewable energy sources, the evolving costs and performance characteristics of individual technologies, and the characteristics of interacting technologies, detailed system simulation and demand modelling is required to determine the cost optimal combinations of technologies for each-and-every potential mini-grid site. Adding to this are the practical details on the ground such as community electricity demand profiles and distances to the grid or fuel sources, as well asthe social and political contexts,such as unknown energy demand uptake or technology acceptance, national electricity system expansion plans and subsidies or taxes, among others. These can all have significant impacts in deciding the applicability of a mini-grid within that context. The scope of the research and modelling framework presented focuses primarily on meeting the specific energy needs in the sub-Saharan African context. Thus, in being transparent, utilizing freely available software and data as well as aiming to be reproducible, scalable and customizable; the model aims to be fully flexible, staying relevant to other unique contexts and useful in answering unknown future research questions. The techno-economic model implementation presented in this paper simulates hourly mini-grid operation using meteorological data, demand profiles, technology capabilities, and costing data to determine the optimal component sizing of hybrid mini-grids appropriate for rural electrification. The results demonstrate the location, renewable resource, technology cost and performance dependencies on system sizing. The model is applied for the investigation of 15 hypothetical mini-grids sites in different regions of South Africa to validate and demonstrate the model’s capabilities. The effect of technology hybridization and future technology cost reductions on the expected cost of energy and the optimal technology configurations are demonstrated. The modelling results also showed that the combination of hydrogen fuel cell and electrolysers was not an economical energy storage with present day technology costs and performance. Thereafter, the model was used to determine an approximate fuel cell and electrolyser cost target curve up to the year 2030. Ultimately, any research efforts through the application of the model, building on the presented framework, are intended to bridge the science-policy boundary and give credible insight for energy and electrification policies, as well as identifying high impact focus areas for ongoing further research

Metodología para el balanceo de rotores empleando un analizador de vibraciones

The present work focuses on the proposal of a methodology for rotors balancing. To achieve the objective, the vibration analyzer, reference OROS 35 and its applications, are used. The different types of unbalances are reviewed and evaluated at work. The methodology is implemented and executed experimentally in different vibration test benches, with different settings. In the same way, the methodology was used with an industrial machine. The results obtained were positive. These results were then compared with the current regulation.El presente trabajo se centra en el planteamiento de una metodología para el balanceo de rotores. Para la consecución de este objetivo se emplea un analizador de vibraciones, de referencia OROS 35, y sus aplicaciones y acelerómetros. Los diferentes tipos de desbalanceo son revisados y evaluados en este trabajo. La metodología es implementada y ejecutada de forma experimental, en diferentes bancos de ensayos de vibraciones, con diferentes configuraciones. De igual forma, la metodología fue usada con una máquina industrial. Los resultados obtenidos fueron positivos. Estos fueron comparados con la normatividad vigent

Leveraging manufacturing process capability in integrated product development

Thesis (S.M.)--Massachusetts Institute of Technology, Sloan School of Management; and, Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1998.Includes bibliographical references (p. 73-74).by Charles E. Hix, Eric B. Kittleson.S.M

Inter-Plant Water-Energy Network Synthesis Considering Seasonal Variations

Water and energy are required for almost all industrial processes to convert raw materials into value-added products. Natural water and energy resources are experiencing depletion stress mainly due to increasing industrial activities and population growth. Integrated networks are employed in industrial cities as a solution to capture waste water and energy and reutilize them to reduce freshwater and energy production and consumption. Due to increasingly strict environmental regulations, integration networks became essential. Water and energy integration networks play a crucial role in significantly reducing water and carbon footprints. Seasonal variations directly affect the performance of water-energy networks. So far, previous works adopted multi-period planning for designing integration networks capable of handling seasonality issue. Multi-period planning may result in complex optimization models. Also, the developed models are sometimes difficult to be implemented due to spatial constraints on pipelines layout. This work mainly investigates the impact of seasonality on network components. Accordingly, a novel approach for designing interplant water-energy integration networks considering seasonal variations is developed in this work. Seasonality analysis was performed for each network element. Several tools were employed including software packages, empirical correlations, and charts. Analysis results were evaluated to assess the significance of the observed variations. Assessment results indicate that seasonal variations of water/energy supply and demand are insignificant considering the overall system. As a result, some solutions were proposed to design a tolerant water-energy network considering seasonality. The proposed approach subsumes maximizing network units’ capacities and utility system based on peak conditions. Water-energy network connectivity is determined based on average demand/supply. Maximum capacity freshwater-to-sink connections are enforced to compensate for any seasonal changes in water demands. To balance this out, maximum capacity discharge connections are made available to all water sources. Any water source-to-sink pipeline is designed based on maximum potential flowrate. Also, water network is designed based on worst case scenario considering treatment units’ minimum removal ratios to ensure compatibility of treatment unit-to-sink connections over different seasons. A formulated mathematical model was expanded to include the proposed approach. Finally, a case study was solved using a stochastic programming tool to illustrate the applicability of the developed model

Heat Transfer Mechanism In Particle-Laden Turbulent Shearless Flows

Particle-laden turbulent flows are one of the complex flow regimes involved in a wide range of environmental, industrial, biomedical and aeronautical applications. Recently the interest has included also the interaction between scalars and particles, and the complex scenario which arises from the interaction of particle finite inertia, temperature transport, and momentum and heat feedback of particles on the flow leads to a multi-scale and multi-physics phenomenon which is not yet fully understood. The present work aims to investigate the fluid-particle thermal interaction in turbulent mixing under one-way and two-way coupling regimes. A recent novel numerical framework has been used to investigate the impact of suspended sub-Kolmogorov inertial particles on heat transfer within the mixing layer which develops at the interface of two regions with different temperature in an isotropic turbulent flow. Temperature has been considered a passive scalar, advected by the solenoidal velocity field, and subject to the particle thermal feedback in the two-way regime. A self-similar stage always develops where all single-point statistics of the carrier fluid and the suspended particles collapse when properly re-scaled. We quantify the effect of particle inertial, parametrized through the Stokes and thermal Stokes numbers, on the heat transfer through the Nusselt number, defined as the ratio of the heat transfer to the thermal diffusion. A scale analysis will be presented. We show how the modulation of fluid temperature gradients due to the statistical alignments of the particle velocity and the local carrier flow temperature gradient field, impacts the overall heat transfer in the two-way coupling regime

Aeronautical engineering: A continuing bibliography with indexes (supplement 266)

This bibliography lists 645 reports, articles, and other documents introduced into the NASA scientific and technical information system in May 1991. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics