Electro-Thermal Model for a Solid Oxide Fuel Cell

An electrochemical-thermal model has been developed to simulate the performance of a solid oxide fuel cell under different operating conditions and geometrical factors. The model was specifically created for a novel manifold design that produces a more uniform thermal distribution inside the cell. Temperature, current, gas distribution and fuel utilization were calculated with the model in the different regions of interest. In addition, the model developed in this research was used to investigate the optimal operating conditions under different gasifier compositions. Accordingly, the model was successfully used to identify the principal operating conditions and geometrical factors that affected the performance of the fuel cell (i.e., gasifier compositions, operating temperature, fuel/oxidant flow rates, and geometrical parameters). The modeling results showed that the novel design was successful in reducing the steep temperature gradients inside the cell but at lower fuel utilization than a conventional co-flow design. However, the model was also used to determine the optimal flow rates at which the fuel utilization of the novel design was quantitatively equivalent to that of conventional cell. Finally, the model was used to investigate the factors that affected the performance of an experimental cell developed at the EERC. Active surface area and contact resistance were identified as principal limiting factors in the performance of the cell for our specific experiments. Based on these assumptions a new experimental cell was constructed. The experimental results of the new design gave a six-fold increase in performance with respect to the original design

Analysis of the efficiency of wind turbine gearboxes using the temperature variable

The aim of this paper is to evaluate how lubricant selection affects gearbox efficiency and overall energy production by analysing real data from wind farms, monitored and controlled by a Supervisory Control and Data Acquisition (SCADA system). The turbines analysed worked with two or more oil types for the same amount of hours, which allowed to establish relations between the active power curves and wind velocity; oil temperature inside gearboxes and wind velocity; and oil temperature inside gearboxes and active power production. The results of this study evidenced a direct relation between oil characteristics and energy efficiency i.e. gearboxes working with mineral oil perform better then gearboxes working with synthetic oils. Those differences can be significant in terms of active power production. Also, it was observed oil degradation as function of temperature increase, with changes on viscosity, which reveals that temperature behaviour along the active power curve is strongly related to oil' characteristics. (C) 2018 Elsevier Ltd. All rights reserved.Agência financiadora Portuguese Foundation for Science and Technology (FCT) PTDC/AAG-TEC/1710/2014 MONITOR project - Atlantic Area EAPA_333/2016 Portuguese Foundation for Science and Technology under the Portuguese Researchers' Programme 2014 IF/00286/2014/CP1234 Marie Sklodowska-Curie Actions of the European Union's H2020-MSCA-IF-EF-RI-2016/under REA - 748747info:eu-repo/semantics/publishedVersionhttp://creativecommons.org/licenses/by/4.0

User-interface technologies for the industrial environment: towards the cyber-factory

In the past few years the so-called gadgets like cellular phones, personal data assistants and digital cameras are more widespread even with less technological aware users. However, for several reasons, the factory-floor itself seems to be hermetic to this changes ... After the fieldbus revolution, the factory-floor has seen an increased use of more and more powerful programmable logic controllers and user interfaces but the way they are used remains almost the same. We believe that new user-computer interaction techniques including multimedia and augmented rcaliry combined with now affordable technologies like wearable computers and wireless networks can change the way the factory personal works together with the roachines and the information system on the factory-floor. This new age is already starting with innovative uses of communication networks on the factory-floor either using "standard" networks or enhancing industrial networks with multimedia and wireless capabilities

Esguince cervical por accidente de tráfico laboral in itinere. Influencia de la existencia de la prestación económica en su evolución

53 páginas.Trabajo de Curso Experto Universitario en Valoración Médica de Incapacidades (2016/2017). Tutor: José Manuel Burgos Moreno. Durante los últimos años, la problemática de salud y de absentismo laboral por latigazo cervical como consecuencia de accidentes de tráfico, está alcanzando elevados niveles en España. En el año 2016 se produjeron 102.362 accidentes de tráfico con víctimas, en las que perdieron la vida 1.810 personas y otras 9.755 fueron heridas que necesitaron ingreso hospitalario. Estos datos se refieren a los accidentes ocurridos en vías urbanas e interurbanas y con el seguimiento de la evolución de los heridos hasta 30 días después del accidente en 2016, por tanto son datos consolidados. Los pacientes que tienen accidente con daños a terceros ponen más reclamaciones, están más tiempo de baja, realizan más rehabilitación, generan más cantidad de pruebas complementarias, son un alta con conflictos y realizan mayor cantidad de impugnaciones de la misma. Este trabajo plantea que de estar mejor regulada la prestación económica por incapacidad temporal debida al latigazo cervical, los procesos de baja laboral, no se alargarían, e incluso en muchos casos no se producirían

Condição humana e organização social e política: crise e as ideias de Regionalismo e de Europa das Regiões

Partindo da crise que se abate sobre o modelo moderno de Estado soberano desde as duas guerras mundiais do último século, o texto procura explorar o conceito de regionalismo, perspectivando-o como utopia e como demanda de uma forma alternativa de organização social e política. Paralelamente, procede-se à exploração de dois projectos alternativos. Primeiro, o projecto de Europa das regiões, que enforma o ideário federalista de meados do século XX de substituição da Europa dos Estado por uma Europa das Regiões - o qual, paradoxalmente, viria impedir as Regiões de aceder ao processo de integração europeia. Segundo, o projecto de Europa com Regiões, que se viria a estabelecer, de forma lenta, se bem que gradual, primeiro no Conselho e na União Europeia, a partir de meados da década de oitenta do século XX.ABSTRACT: Starting from the crisis that befalls the modern sovereign state since the two world wars of the last century, the text aims to explore the concept of regionalism, viewing it as an Utopia and as a demand for an alternative form of social and political organization. In parallel, it proceeds to the exploration of two alternative projects. First, the project Europe of the Regions, which shapes the federalist ideas of the mid-twentieth century which points to the replacement of the Europe of States with a Europe of Regions – which paradoxically, would prevent the Regions from acceding to the European Integration Process. Second, the project of Europe with Regions, Europe with the Regions, which unfolded in a slow, albeit gradual way, in the firstly in the Council of Europe and afterwards in the European Union, from the mid-eighties of the twentieth century

A survey of techniques and technologies for web-based real-time interactive rendering

When exploring a virtual environment, realism depends mainly on two factors: realistic images and real-time feedback (motions, behaviour etc.). In this context, photo realism and physical validity of computer generated images required by emerging applications, such as advanced e-commerce, still impose major challenges in the area of rendering research whereas the complexity of lighting phenomena further requires powerful and predictable computing if time constraints must be attained. In this technical report we address the state-of-the-art on rendering, trying to put the focus on approaches, techniques and technologies that might enable real-time interactive web-based clientserver rendering systems. The focus is on the end-systems and not the networking technologies used to interconnect client(s) and server(s).Siemens; Bertelsmann mediaSystems GmbH; Eptron Multimedia; Instituto Politécnico do Porto - ISEP-IPP; Institute Laboratory for Mixed Realities at the Academy of Media Arts Cologne, LMR; Mälardalen Real-Time Research Centre (MRTC) at Mälardalen University in Västerås; Q-Systems

On the labor share the long-run equilibrium and its adjustment process

This research computes an Equilibrium Labor Share using a VECM for a panel of 19 countries, analyzes what determines the speed at which the labor share adjusts towards that equilibrium and decomposes this adjustment in terms of real wages and employment. Results suggest that the speed at which a country adjusts decreases with employment protection legislation and labor taxes. Most countries’ labor shares adjustment is made through real wages changes instead of changing employment, suggesting that wage moderation policies may play an important role on the adjustment process without harming employment. Keywords: Equilibriu

Marine energy prototype testing at Ria Formosa

Economic growth and increasing human demands are among the most important factors for growing world energy consumption. Energy is present in everything around us: it is a property of all objects and is essential to life. We find various forms of energy in the world around us. When plants grow, for example, they are converting sunlight energy into chemical energy in the form of carbohydrates and other compounds stored in your body (e.g. sugars). The form of energy that man uses most today is the chemical energy contained in fossil fuels, such as oil, coal and natural gas. About 80% of the energy we use comes from these sources. However, these sources are very polluting, since their use releases substances harmful to the environment and to public health. An example of this is the increased concentration of greenhouse gases such as carbon dioxide (CO2) in the atmosphere, which is a cause of climate change. In addition to pollutants, these sources of energy are non-renewable, which means that they are being consumed at a faster rate than is necessary for their production, so their availability is decreasing. Due to the increasing oil and natural gas prices, reduced fuel reserves and the requirement for reduced CO2 emissions to avert climate change, the use of alternative energy sources is both financially unavoidable and environmentally preferable (UN, 2015). Hence, generating renewable energy is nowadays one of the most relevant endeavours for research. Countries worldwide now recognise the need to incorporate renewable energy resources in their energy policy as an alternative to finite fossil fuel resources in order to achieve future energy security and to mitigate the effects of climate change induced by human activities. Today, renewable energy is now firmly entrenched as the world's fastest growing energy sector (IEA, 2017).info:eu-repo/semantics/publishedVersio