Percorrer por data de Publicação, começado por "2015"
A mostrar 1 - 10 de 823
Resultados por página
Opções de ordenação
- Experimental study of the influence of consumers movement parallel to the frontal opening of a multideck display case on the evaporator's thermal performancePublication . Heidinger, Gustavo Galdi; Nascimento, Samuel Mariano do; Gaspar, Pedro Dinis; Silva, Pedro Dinho daThis paper reports the results of experimental tests performed according to ISO 23953 (climate class n° 3: 25ºC and 60%) in an open refrigerated multideck display case (ORDC) to evaluate the influence of consumers passing in front of its opening on the thermal performance of the evaporator. The consumers’ passage in front of the ORDC is simulated by a robotic mannequin: MARIA - Mannequin for Automatic Replication of the Interference in the Air curtain. Tests are performed for MARIA velocity's ranging from 0.2 ms-1 to 0.8 ms-1, with 0.2 ms-1 velocity steps for two conditions: mannequin moving towards or against the airflow of the test room. All tests are performed in an ORDC with dual air curtain. The results quantify the influence of MARIA translational velocity on the frost formation in the evaporator coil and how this phenomenon affects the evaporator's airflow, inlet and outlet temperatures and sensible and latent heat loads. The analysis of experimental data provides valuable information for evaporator design taking into account usual in-store conditions.
- Numerical Simulation of Twin Impinging Jets in Tandem Through a CrossflowPublication . Vieira, Diana; Barata, Jorge M M; Neves, Fernando M. S. P.; Silva, A. R. R.The flow field of ground vortex generated by twin impinging jets in tandem through a crossflow is numerically studied in detail. Numerical simulation and visualization are presented for two turbulent circular jets emerging into a low velocity cross stream, impinging after on a flat surface perpendicular to the geometrical jet nozzle axis. The numerical study is based in experimental studies done early, so all the features of the experimental flow were maintained when the numerical simulation was performed. The Reynolds number used was based on the jet exit conditions of 43.000-105.000, a jet to crossflow velocity ratio of 22.5-43.8 an impinging height of 20.1 jet diameters and an interject spacing’s of S = 5D and L = 6D. The analysis of the flow was extended to regions and flow conditions for which no measurements have been obtained in last experimental studies, i.e., for velocity ratios of 7.5-60. The numerical results show that for the smallest velocity ratios the jets initially do not mix but remain together in two layers. Three different types of flow regimes were identify, therefore when VSTOL aircrafts operating in ground vicinity, only the regime with strong impingement on ground and with a formation of a ground vortex is relevant. The numerical results allowed to extend the last experimental studies and prove that the deflection of the rear jet is due to the competing influences the wake, the shear layer, the downstream wall jet of the first jet and the crossflow.
- Eusébio: la construcción del héroe en la prensa escrita. FonsecaPublication . Canavilhas, JoãoEl traslado del cuerpo del jugador Eusébio al Panteón Nacional generó polémica en Portugal. Se discutía si un futbolista debería estar en el Panteón, un lugar reservado a los héroes nacionales. El héroe es alguien que vive la mayor parte del tiempo como los demás, pero que en determinadas condiciones se irgue a la posición de semidiós (Rubio, 2001). En este momento gana el derecho a reposar en un espacio reservado a todos (pan) los dioses (theos). ¿Pero cómo se transforma un jugador de fútbol en un dios del césped, un héroe deportivo? Por sus acciones, evidentemente, pero sobre todo por la forma como los medios de comunicación relatan al público sus hazañas. En el momento de la muerte de Eusébio, enero de 2014, la historia del jugador ha sido recuperada por los medios de comunicación. Se presentó así una excelente ocasión para estudiar la forma como se ha reconstruido la imagen de un jugador de nivel mundial cuya carrera ocurrió cuando el fútbol no tenía la mediatización actual. En el trabajo se estudian las noticias de prensa publicadas en el día siguiente a su muerte. La hipótesis es que, en situaciones como esta, los periódicos buscan contextualizar semánticamente el fenómeno deportivo en un escenario mítico. Con recurso al análisis de contenidos se buscaron marcas de la construcción del héroe en un estudio cuantitativo (repetición de palabras asociadas al universo mítico) y cualitativo (formas discursivas para exaltar el héroe).
- PREFACE - To the book by Nono Sumampouw, Menjadi Manado: Torang Samua Basudara, Sabla Aer, dan Pembentukan Identitas SosialPublication . Schouten, Maria Johanna ChristinaPreface to an anthropological study about the city of Manado (Indonesia). Attention is paid to its geostrategic location and the diversity of its population, in a historical perspective. Includes reflections on anthropological practices and analysis.
- Discurso Web, Modelos Teóricos e Sistemas de Argumentação: Implicações para a Tomada de DecisãoPublication . Freire, Manuela; Antunes, Francisco; Costa, João PauloA crescente importância atribuída pelas organizações à tomada de decisão em contexto web requer que sejam definidos e implementados mecanismos mais eficientes para apoiar as atividades da mesma. As redes sociais, enquanto espaços de colaboração, permitem que os atores sociais interajam entre si independentemente do local e espaço onde se encontram. Um aspeto importante dos ambientes virtuais é que, de uma forma ou de outra, se verifica a existência de discussão argumentativa e nesse sentido a web constitui-se como uma excelente ferramenta para apoiar a representação, divulgação e recuperação do conhecimento, pois pode realçar a expressão argumentativa, devido à sua omnipresença e abertura. Através da captura e análise do discurso web, é possível obter informação relevante que reflete a opinião e a manifestação de pontos de vista que podem ser úteis para a tomada de decisão. Para o efeito, é importante identificar e perceber a estrutura da rede de atores sociais, a comunicação, contexto, linguagem, linguística e conteúdo do discurso web, visto que as palavras e frases estão sempre carregadas de sentidos e intenções, que podem ser definidas de forma diferente.A argumentação tem o seu foco nos diálogos com o objetivo de aumentar ou diminuir a aceitação de um ponto de vista, a fim de chegar a uma conclusão através de um raciocínio lógico. Nesse contexto, temos assistido a um aumento importante no desenvolvimento de sistemas de colaboração centrados na web, que funcionam como facilitadores da argumentação. Nestes, diferentes pontos de vista podem ser apresentados, contestados e avaliados, e a tomada de decisão colaborativa é efetuada através de debates e negociações entre um grupo de indivíduos. Tendo em conta este novo paradigma, este trabalho objetivou consolidar conhecimentos associados ao discurso web, à argumentação e decisão, aos modelos teóricos de argumentação e aos sistemas de argumentação computacional para a web.
- Influence of Strength, Sprint Running, and Combined Strength and Sprint Running Training on Short Sprint Performance in Young AdultsPublication . Marques, MC; Gabbett, T. J.; Marinho, Daniel; Blazevich, Anthony; Sousa, A.; van den Tillaar, Roland; Izquierdo, MikelThe purpose of this study was to assess the degree of transference of 6 weeks of full squat vs. full squat plus sprint running training to short (ranged from 0-10 to 0-30 m) sprint running performance in non-athletes. We hypothesized that a speed-full-squat training regimen could enhance squat strength and power with simultaneous improvements in short sprint performance. 122 physically active adults (age: 20.5±2.5 years; body mass: 65.8±6.1 kg; height: 1.71±0.08 m) were randomly divided into 4 groups: full squat training (n=36), combined full squat and sprint training (n=32), speed training only (n=34) and non-training control group (n=20). Each training group completed 2 sessions per week over 6 weeks, while the control group performed only their normal physical activity. Sprint performance was improved after sprint running or full squat training alone (1.7% and 1.8% P<0.05, respectively), however larger enhancements (2.3%; P<0.01) were observed after the combined full squat plus sprint training intervention. These results suggest that in recreationally active adults, combined full squat and sprint training provides a greater stimulus for improving sprint performance than either modality alone.
- The role of Portuguese electricity generation regimes and industrial productionPublication . Marques, António Cardoso; Fuinhas, José AlbertoThis paper examines how renewables (special regime) simultaneously interact with conventional sources (ordinary regime), within the Portuguese electricity generation system. There is also an appraisal of the relationship between these two regimes and economic activity, using the industrial production index. First difference VAR modelling was applied for monthly data for the time span of 2007:M1 to 2012:M10. The appropriateness of the VAR is proved. The relationship between variables develops within a structure of endogeneity, i.e., they generate feedback and may be both explained and explaining variables, simultaneously. The outcomes show a strong complementarity between the ordinary and special regimes. Economic activity causes electricity consumption but only the special regime causes economic activity. Moreover, the non-renewable component of the special regime does not cause a need for backup from either the ordinary regime or imports, contributing to a reduction in energy dependency.
- Tourism Charter of Serra da Estrela: a tool for planning and tourism promotionPublication . Castro, Emanuel; Fernandes, Gonçalo; Firmino, GiselaThe Tourism Charter of Serra da Estrela intends to be a management, promotion and revaluation tool of Serra da Estrela as a tourism destination and its products. It is therefore important to know the resources in its territorial context and how they are suitable for tourism, seeking to optimize and manage the potential impacts produced. The tourism phenomenon has an inductor character, able to promote territorial resources and contribute to the development of indigenous potential. It is an activity that is the driving force of development in many regional economies, when properly managed. By its nature, tourism is a complex phenomenon that integrates political, economic, social, cultural, biophysical, ecological and aesthetic subsystems, and its sustainability comes from the symbiosis between these different fields. At the same time, it is necessary to respond simultaneously to the expectations of visitors and the aspirations of local populations. In this context, this paper aims to describe the development of the Tourism Charter of Serra da Estrela, presenting a dynamic character through the application of geographic information methodologies which will be not only a tourist planning tool, but also an interactive platform to which tourists can access information.
- Estudo numérico do desempenho térmico de um armário exterior para equipamentos de telecomunicações móveisPublication . Duarte, Miguel Vicente; Silva, Pedro Dinho da; Pires, Luís Carlos Carvalho; Gaspar, Pedro DinisOutdoor cabinets that house telecommunication equipment are used to protect electronic equipment from the harsh environmental conditions. The number of outdoor cabinets used has been growing in recent decades, boosted by the world expansion of mobile telecommunications networks. The disposition of telecommunications equipment inside a cabinet (i.e., the thermal design) became a critical factor due to the miniaturization of electronic components and the increase of packing density. To mitigate this problem, energy-intensive cooling techniques (e.g., air conditioning) began to be used. Studies shown that approximately 25% of the total energy consumed in an outdoor cabinet is used for cooling. It is intended with this work, the thermal study of an outdoor cabinet using a CFD software to characterize its thermal behaviour, according to the influence of the environment temperature, the air flow through the cabinet and the heat dissipated in its interior by the telecommunications equipment. According the results obtained in this study it can be concluded that even for the less favourable case (TA=20.1 °C; Qar=60 m3 h -1 e qdis=480 W), none of the telecommunications equipment inside the cabinet is under risk, since the Tmax,cabinet ≈ 4 0°C is lower than the Tmax,recommended ≈55°C.
- Characterization theorem for Laguerre- Hahn orthogonal polynomials on non-uniform latticesPublication . Rebocho, M. N.; Branquinho, A.A characterization theorem for Laguerre–Hahn orthogonal polynomials on non-uniform lattices is stated and proved.This theorem proves the equivalence between the Riccati equation for the formal Stieltjes function, linear first-order difference relations for the orthogonal polynomials as well as for the associated polynomials of the first kind, and linear first-order difference relations for the functions of the second kind.