766 resultados para Trip steels


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Approaches exploiting trait distribution extremes may be used to identify loci associated with common traits, but it is unknown whether these loci are generalizable to the broader population. In a genome-wide search for loci associated with the upper versus the lower 5th percentiles of body mass index, height and waist-to-hip ratio, as well as clinical classes of obesity, including up to 263,407 individuals of European ancestry, we identified 4 new loci (IGFBP4, H6PD, RSRC1 and PPP2R2A) influencing height detected in the distribution tails and 7 new loci (HNF4G, RPTOR, GNAT2, MRPS33P4, ADCY9, HS6ST3 and ZZZ3) for clinical classes of obesity. Further, we find a large overlap in genetic structure and the distribution of variants between traits based on extremes and the general population and little etiological heterogeneity between obesity subgroups.

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This paper investigates a flexible fault ride through strategy for power systems in China with high wind power penetration. The strategy comprises of adaptive fault ride through requirements and maximum power restrictions of the wind farms with weak fault ride through capabilities. The slight faults and moderate faults with high probability are the main defending objective of the strategy. The adaptive fault ride through requirement in the strategy consists of two sub fault ride through requirements, a temporary slight voltage ride through requirement corresponding to a slight fault incident, with a moderate voltage ride through requirement corresponding to a moderate fault. The temporary overloading capability of the wind farm is reflected in both requirements to enhance the capability to defend slight faults and to avoid tripping when the crowbar is disconnected after moderate faults are cleared. For those wind farms that cannot meet the adaptive fault ride through requirement, restrictions are put on the maximum power output. Simulation results show that the flexible fault ride through strategy increases the fault ride through capability of the wind farm clusters and reduces the wind power curtailment during faults.

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OBJECTIVES:
We assessed whether policies designed to safeguard young motorcyclists would be effective given shifts in ownership toward high-powered motorcycles.
METHODS:
We investigated population-wide motor vehicle driver and motorcyclist casualties (excluding passengers) recorded in Britain between 2002 and 2009. To adjust for exposure and measure individual risk, we used the estimated number of trips of motorcyclists and drivers, which had been collected as part of a national travel survey.
RESULTS:
Motorcyclists were 76 times more likely to be killed than were drivers for every trip. Older motorcyclist age-strongly linked to experience, skill set, and riding behavior-did not abate the risks of high-powered motorcycles. Older motorcyclists made more trips on high-powered motorcycles.
CONCLUSIONS:
Tighter engine size restrictions would help reduce the use of high-powered motorcycles. Policymakers should introduce health warnings on the risks of high-powered motorcycles and the benefits of safety equipment.

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The dissolution of MnS inclusions could induce pitting corrosion in stainless steels, but its dissolution mechanism is poorly understood at the atomic scale. With the help of ab initio molecular dynamics calculations, one inevitable step in the dissolution of MnS is studied by simulating the process of one Mn ion leaving the surface. The reaction mechanism is determined to contain three steps with two large barriers and a small one, leading to two slow steps in the Mn ion dissolution. Comparing to the Na ion dissolution from NaCl, the barriers of the Mn ion dissolution are much larger, which is a reflection of their different electronic structures.

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Laves phase has been widely accepted to cause the impact brittleness of 9–12Cr martensitic heat-resistant steels after long time aging at elevated temperatures. However, in the present research, the impact toughness of the already brittle P92 steel aged at 600 °C for 2035 h could be restored to the original level by reheating at 700 °C for 1 h, with Laves phase barely changed. This interesting result strongly indicated that the presence of Laves phase might not be the real reason for the impact brittleness.

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Nitride-strengthened reduced activation ferritic/martensitic (RAFM) steels are developed taking advantage of the high thermal stability of nitrides. In the current study, the microstructure and mechanical properties of a nitride-strengthened RAFM steel with improved composition were investigated. Fully martensitic microstructure with fine nitrides dispersion was achieved in the steel. In all, 1.4 pct Mn is sufficient to suppress delta ferrite and assure the steel of the full martensitic microstructure. Compared to Eurofer97, the steel showed similar strength at room temperature but higher strength at 873 K (600 °C). The steel exhibited very high impact toughness and a low ductile-to-brittle transition temperature (DBTT) of 243 K (–30 °C), which could be further reduced by purification.

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Copper is accumulated in recycled steels and is difficult to be removed during steelmaking processes when steel scrap is used as steel sources. Meanwhile, copper characteristic properties are of importance both to human beings and to animals and plants. In this paper, integrated copper coating was observed on the surface of copper-containing steels when the steels were heated at around 1150°C. However, the copper was separately scattered after heating at 1000°C. The forming mechanisms of copper coating will be discussed in detail. By choosing proper descaling reagent, self-generated oxidation-induced copper coating appeared on the steel surface. The method proposed in this work is environmentally friendly for nontoxic chemicals being used. In addition, this provides a new concept for producing protective composite by oxidizing from the substrate directly and there is no binding problem.

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Copper is accumulated in recycled steels and is difficult to be removed during steelmaking processes when steel scrap is used as steel sources. Meanwhile, copper characteristics are of importance both to human beings and to animals and plants. In this paper, integrated copper coating was observed on the surface of copper-containing steels when the steels were heated at around 1150°C. However, the copper was separately scattered in and under the surface rust after heating at 1000°C. The forming mechanisms of copper coating are discussed in detail. By choosing a proper descaling reagent, self-generated oxidation-induced copper coating appeared on the steel surface. The method proposed in this work is environmentally friendly for nontoxic chemicals being used. In addition, this provides a new concept for producing protective composite by oxidizing from the substrate directly and there is no bonding problem.

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The preferences of users are important in route search and planning. For example, when a user plans a trip within a city, their preferences can be expressed as keywords shopping mall, restaurant, and museum, with weights 0.5, 0.4, and 0.1, respectively. The resulting route should best satisfy their weighted preferences. In this paper, we take into account the weighted user preferences in route search, and present a keyword coverage problem, which finds an optimal route from a source location to a target location such that the keyword coverage is optimized and that the budget score satisfies a specified constraint. We prove that this problem is NP-hard. To solve this complex problem, we pro- pose an optimal route search based on an A* variant for which we have defined an admissible heuristic function. The experiments conducted on real-world datasets demonstrate both the efficiency and accu- racy of our proposed algorithms.

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A partir de uma amostra de 600 turistas internacionais que circulam em Portugal, Espanha e Itália, este estudo identifica as principais os conceitos chave relacionados com o terrorismo, a percepção de risco, envolvimento e motivação para a segurança dos turistas internacionais. Diferentes níveis de preocupação relativamente à segurança pode influenciar as decisões dos turistas. No seu processo de decisão, os turistas avaliam vários factores, nomeadamente, o nível de risco ou de segurança que consideram nos destinos (Sonmez, 1998). Os turistas adoptam uma atitude protectora alterando os seus comportamentos durante os processos de decisão, substituindo os destinos que consideram inseguros por outros associados a uma maior segurança (Gu & Martin, 1992; Mansfeld, 1996). O terrorismo exacerbado pelos media tem efeitos graves nas receitas dos destinos turísticos (Taylor, 2006). Através da publicidade negativa, um destino turístico que experiencia um incidente terrorista pode ver a sua reputação danificada e a actividade turística severamente comprometida (Sonmez, 1998). Inclusivamente, a imageme negativa de um destino pode ser generalizada e pode também afectar outros países ou regiões por períodos de tempo indeterminados (Taylor, 2006). Um modelo de equações estruturais revela que os turistas são motivados para adquirir informação sobre o terrorismo nos media, nomeadamente mostram atenção e interesse sobre essas notícias e esse facto influencia directamente o seu risco percebido. A percepção de risco influencia directamente o envolvimento dos turistas no planeamento da viagem, especificamente a procura de informação antes da viagem e quando estão no destino. A percepção de risco e o envolvimento dos turistas influencia a percepção da importância da segurança.A discussão foca as implicações deste modelo para a teoria e para as instituições e organizações turísticas. São igualmente apresentadas recomendações para os gestores e promotores dos destinos e para os gestores das organizações turísticas. Direcções futuras de investigação são igualmente apresentadas.

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No actual contexto de competitividade, os destinos turísticos podem diferenciar-se pela imagem que os turistas e residentes têm sobre eles enquanto espaços alternativos de lazer e turismo (Baloglu & Mangaloglu, 2001). A imagem dos destinos constitui um conceito central na literatura em turismo porque está fortemente relacionada com o comportamento dos residentes e dos turistas (Baloglu & McCleary, 1999). A imagem afecta o comportamento de escolha e avaliação do destino, da viagem e da participação e experiência turísticas (Echtner and Ritchie 1991; Lee & Lee, 2009). Por outro lado, os residentes têm, também eles, uma imagem sobre o local onde residem que pode e deve ser analisada, afectando, por sua vez, a percepção que os turistas têm desses espaços (Gallarza, Saura & García, 2001). Alguns destinos turísticos possuem características simbólicas que exercem forte influência na formação da sua imagem, como são o caso dos espaços de montanha. De facto, as montanhas constituem um dos mais profundos arquétipos da Humanidade simbolizando poder, liberdade e eternidade (Smethurst, 2000, p.36). As regiões de montanha têm-se tornado num dos mais atractivos destinos turísticos constituindo a sua procura, actualmente, 20% dos fluxos turísticos globais com 500 milhões de turistas anualmente (UNEP, 2002; Thomas et al., 2006). Mas até muito recentemente, os estudos sobre os espaços de montanha limitavam-se, maioritariamente, às suas características físicas, ecológicas e ambientais (Smethurst, 2000). Uma abordagem do ponto de vista do turismo de montanha, no contexto da imagem, pode revelar-se, assim, essencial. Neste contexto, o presente estudo pretende analisar, de uma forma holística e multidisciplinar, a imagem que os residentes e turistas têm dos espaços de montanha, bem como o respectivo gap. O objectivo central é construir uma escala MDI - Mountain Destination Image Scale - no sentido de medir os parâmetros da imagem do destino, incluindo factores cognitivos e afectivos e tendo em conta os grupos populacionais turistas e residentes. Com base numa extensa revisão da literatura em imagem dos destinos turísticos e nos significados sociais e culturais da montanha ao longo do tempo, e no âmbito do trabalho empírico realizado a 315 turistas e 315 residentes na Serra da Estrela (Portugal), Alpes (França, Áustria e Suiça) e Picos da Europa (Espanha), os resultados indicam que a escala multidimensional MDI integra cinco dimensões de imagem de montanha pelos turistas: (1) histórico-cultural, (2) natural/ecológica, (3) social e prestígio, (4) lazer e desporto e (5) afectiva; e três dimensões percepcionadas pelos residentes: (1) mística/sagrada, (2) histórico-cultural e (3) afectiva. A discussão é centrada nas implicações teóricas e práticas da escala MDI no planeamento, gestão e marketing dos destinos turísticos de montanha. São igualmente apresentadas as limitações do presente estudo e traçadas algumas linhas orientadoras para investigações futuras.

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Relatório da Prática de Ensino Supervisionada, Mestrado em Ensino de Biologia e Geologia no 3º Ciclo do Ensino Básico e Ensino Secundário, Universidade de Lisboa, 2011

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LivingTV's flagship series, Most Haunted, has been haunting the satellite network since 2002. The set-up of the series is straightforward: a team of investigators, including a historian, a parapsychologist, and "spiritualist medium" Derek Acorah, "legend-trip," spending the night at some location within the United Kingdom that is reputed to be haunted, with the hopes of catching on video concrete proof of the existence of ghosts. However, unlike other reality television or true-life supernatural television shows, Most Haunted includes and addresses the audience less as a spectator and more as an active participant in the ghost hunt. Watching Most Haunted, we are directed not so much to accept or reject the evidence provided, as to engage in the debate over the evidence's veracity. Like legend-telling in its oral form, belief in or rejection of the truth-claims of the story are less central than the possibility of the narrative's truth - a position that invites debates about those truth-claims. This paper argues that Most Haunted, in its premise and structure, not only depicts or represents legend texts (here ghost stories), but engages the audience in the debates about the status of its truth-claims, thereby bringing this mass-mediated popular culture text closer to the folkloristic, legend-telling dynamic than other similar shows.

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Relatório da Prática de Ensino Supervisionada, Mestrado em Ensino de Artes Visuais, Universidade de Lisboa, 2014

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Freight transportation system is critical to economic activity but it carries significant environmental costs, notably GHG emissions and climate change : energy use and corresponding CO2 emissions is increasing faster in freight transport than in other sectors and this increase is primarily the result of increased trade. This paper compares the transport activities, associated energy consumption and CO2 emissions of different supply chains for a range of products in three countries: Belgium, France and United Kingdom. Among the products considered are furniture and ‘fruits & vegetables’. For each of these products, different supply chains, involving more or less transport activity and associated energy consumption are analysed in each country. The comparison highlights some of the main factors that influence GHG emissions for different supply chains and illustrates how they vary according to product and country of final distribution. In more detail, the paper addresses the main differences between the supply chains of these products namely, the origin of their sourcing, the logistical organisation between production and retail and different types of retail outlet. The origin of the sourcing impact is mainly related to distance. The impact of the logistical organisation between raw material and retail on GHG emissions is linked to the mode and vehicle choice and to the load factor. As for retail, the consumer trip emissions, between his home and the retail outlet, are also an important part of the whole supply chain emissions. It is worthwhile to notice that our goal in this project is to consider the whole supply chain, from production to consumption. Therefore a particular focus is put on the mobility behaviours of consumers purchasing the studied products during their shopping and dropping back home activities related to these products. Especially a web based survey has been conducted and the gathered results offer an opportunity for drawing a more detailed picture of the associated CO2 emissions. This paper uses the results of an ongoing research on supply chain energy efficiency, funded by ADEME (the French Energy Agency) through the French program on transport research (PREDIT). This research is based on a comprehensive review of the various approaches to quantifying the environmental impacts of supply chains together with data collection from a range of organisations including manufacturers, retailers and transport companies. We will first present the developed methodologies, then the results corresponding to each studied product will be described. A discussion of the potential application of the research approach to the wider debate about the environmental impact of freight transport and the scope for GHG emissions reduction targets to be achieved will be included.