966 resultados para Suspension bridge
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The concept of the United Kingdom acting as a bridge between Europe and the United States has been a key element in British foreign policy for six decades. Under the second Blair Premiership it reached both its apogee and its nadir. This paper analyses these developments focusing both on the transatlantic and European ends. Particular attention is paid to the failure of the Blair government either to establish a secure place for Britain as a co-leader or to make the British people more comfortable in their European skins. This failure occurred at a period when the EU is characterised by leadership transition and confusion. New leaderships will emerge in the EU over the next two years but it seems unlikely that Britain, characterised by a continuing disconnect between a Euro-sceptic public discourse and deep involvement at a governmental level will develop a European policy narrative that is regarded as convincing at either the EU or domestic level. This weakness is compounded by a failure to develop new thinking about the rise of new powers such as China and India.
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In the clinical/microbiological laboratory there are currently several ways of separating specific cells from a fluid suspension. Conventionally cells can be separated based on size, density, electrical charge, light-scattering properties, and antigenic surface properties. Separating cells using these parameters can require complex technologies and specialist equipment. This paper proposes new Bio-MEMS (microelectromechanical systems) filtration chips manufactured using deep reactive ion etching (DRIE) technology that, when used in conjunction with an optical microscope and a syringe, can filter and grade cells for size without the requirement for additional expensive equipment. These chips also offer great versatility in terms of design and their low cost allows them to be disposable, eliminating sample contamination. The pumping mechanism, unlike many other current filtration techniques, leaves samples mechanically and chemically undamaged. In this paper the principles behind harnessing passive pumping are explored, modelled, and validated against empirical data, and their integration into a microfluidic device to separate cells from a mixed population suspension is described. The design, means of manufacture, and results from preliminary tests are also presented. © IMechE 2007.
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Using biomimetic chemical reduction or Clostridium perfringens cell extract containing azoreductase, the dimer-fluorescent probe 2,4-O-bisdansyl-6,7- diazabicyclooct-6-ene, which possesses a conformationally constrained cis-azo bridge, is reduced to the tetra-equatorial 2,4-O-bisdansyl-cyclohexyl-3,5- bisammonium salt which exhibits fluorescence indicative of a dansyl monomer. © 2012 The Royal Society of Chemistry.
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In the context of the UK public policy goal to increase community and social cohesion, this article explores the nature of local 'bridge-building' – activities intended to increase interpersonal contacts between diverse ethnic, faith and nationality groups. We draw on earlier research in a range of fields to develop the bridge-building concept and present findings from a study that identified community-level projects with bridge-building as a specific aim. We show the range of groupings involved, the activities encompassed and their organisational features. We consider the actual and potential contribution of local bridge-building to cohesion in the light of earlier research and our own study.
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A novel low-cost photonic PON-to-RoF bridge is presented, allowing simultaneous wireline and wireless multi-Gbps data transmission with minor impact on deployed PON networks. Simulation results show that the proposed scheme does not require narrow-linewidth lasers when envelope detector mobile terminals are used, since the transmission performance is not limited by the phase noise but by the RIN and the frequency difference between the two beating lasers. © 2013 IEEE.
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This paper presents a case for the study of non-cognitive psychological processes in Translation Studies (TS). More specifically, it aims to highlight the value of studying the emotional intelligence (EI) of translators and interpreters. Firstly, the concept of EI is defined and a review of trait EI profiling is undertaken, with a focus on two recent studies that have relevance for TS. Secondly, recent research within TS and related disciplines that provides evidence of the value of studying the affective and emotional traits of translators and interpreters is discussed. The final section of this paper provides some recommendations for the study of EI in TS research to benefit the translation and interpreting community. It will be argued that investigating emotional intelligence is both necessary and desirable to gain a deeper understanding of translation and interpreting processes.
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For intelligent DC distributed power systems, data communication plays a vital role in system control and device monitoring. To achieve communication in a cost effective way, power/signal dual modulation (PSDM), a method that integrates data transmission with power conversion, can be utilized. In this paper, an improved PSDM method using phase shift full bridge (PSFB) converter is proposed. This method introduces a phase control based freedom in the conventional PSFB control loop to realize communication using the same power conversion circuit. In this way, decoupled data modulation and power conversion are realized without extra wiring and coupling units, and thus the system structure is simplified. More importantly, the signal intensity can be regulated by the proposed perturbation depth, and so this method can adapt to different operating conditions. Application of the proposed method to a DC distributed power system composed of several PSFB converters is discussed. A 2kW prototype system with an embedded 5kbps communication link has been implemented, and the effectiveness of the method is verified by experimental results.
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A new topology of the high frequency alternating current (HFAC) inverter bridge arm is proposed which comprises a coupled inductor, a switching device and an active clamp circuit. Based on it, new single-phase and threephase inverters are proposed and their operating states are analysed along with the traditional H-bridge inverter. Multiphase and multi-level isolated inverters are also developed using the HFAC bridge arm. Furthermore, based on the proposed HFAC, a front-end DC-DC converter is also developed for photovoltaic systems to demonstrate the application of the proposed HFAC converter. Simulation and experimental results from prototype converters are carried out to validate the proposed topologies which can be utilised widely in high frequency power conversion applications such as induction heating and wireless power transfer.
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This work is the first part of a series of studies, which introduces the methodological possibilities of coenological and zoogeographical indication and – following the climate, vegetation and elevation zones – the pattern-describing analysis of the main Oribatid sinusia of the world explored till our days.This current work is a case-study, which displays the comparison of 9 examination sites from 3 different geographical locations. On each location, three vegetation types have been examined: a plain rain-forest, a mossforest and a mountainous paramo. Analyses are based on the hitherto non-published genus-level database and coenological tables of the deceased János Balogh professor. Occurrence of 18 genera is going to be published as new data for the given zoogeographical region.
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Leishmaniasis is one of the most important emerging vector-borne diseases in Western Eurasia. Although winter minimum temperatures limit the present geographical distribution of the vector Phlebotomus species, the heat island effect of the cities and the anthropogenic heat emission together may provide the appropriate environment for the overwintering of sand flies. We studied the climate tempering effect of thermal bridges and the heat island effect in Budapest, Hungary. Thermal imaging was used to measure the heat surplus of heat bridges. The winter heat island effect of the city was evaluated by numerical analysis of the measurements of the Aqua sensor of satellite Terra. We found that the surface temperature of thermal bridges can be at least 3-7 °C higher than the surrounding environment. The heat emission of thermal bridges and the urban heat island effect together can cause at least 10 °C higher minimum ambient temperature in winter nights than the minimum temperature of the peri-urban areas. This milder micro-climate of the built environment can enable the potential overwintering of some important European Phlebotomus species. The anthropogenic heat emission of big cities may explain the observed isolated northward populations of Phlebotomus ariasi in Paris and Phlebotomus neglectus in the agglomeration of Budapest.
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This qualitative study is concerned with exploring the transcultural experiences of ESOL students and connecting their lived experiences to literature in the classroom. The purpose of this study was to describe and explain the transcultural perspectives of six high school and community college students: four Cuban born students and two American born/raised students of Cuban-American culture. The participants were from Barbara Goleman Senior High School and Miami-Dade Community College. The six phenomenological portraits were explored in the form of lived experience pieces, representing the students' transcultural experiences. The data was collected in the form of student interviews, researcher's journal, and document reviews. The following exploratory questions guided this study: (1) From the perspective of four Cuban-born, non-native English-speaking students (NNS), what are the essential structures of their transcultural identities? (2) What are the underlying themes that account for the Cuban NNS students' transcultural experiences? (3) What are the universal transcultural structures among the Cuban NNS students' transcultural experiences and the Cuban-American, native English/Spanish speaking (NESS) students' experiences? (4) What are the possible structural meanings of the Cuban NNS students' interests in relation to their transcultural experiences? (5) What are some connections between the structural themes inherent in the Cuban NNS students' transcultural experiences and teaching literature in ESOL? ^ A phenomenological approach was used to investigate the participants' transcultural experiences, focused on the students' lived experiences. The study consisted of three interview sessions for each of the six participants. The analysis of the data was conducted following the principles of qualitative research, which included participant interviews, thematic analysis, researcher's journal, document reviews, and triangulation. The researcher created portraits representing students' transcultural experiences. Subsequently, the participants' transcultural experiences were used to respond to the exploratory questions, including comparing and contrasting themes and drawing connections among teaching literature in the ESOL classroom. ^ The results of this study show some relevant specific statements and themes that emerged from the students' transcultural data. The results serve as a better understanding of these students' transcultural experiences and the potentiality of connecting their perspectives to literature in the classroom. In addition, this study shows the need for a better understanding of the connection between transcultural experiences and literature in ESOL. ^
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Most of the moveable bridges use open grid steel decks, because these are factory assembled, light-weight, and easy to install. Open grid steel decks, however, are not as skid resistant as solid decks. Costly maintenance, high noise levels, poor riding comfort and susceptibility to vibrations are among the other disadvantages of these decks. The major objective of this research was to develop alternative deck systems which weigh no more than 25 lb/ft2, have solid riding surface, are no more than 4–5 in. thick and are able to withstand prescribed loading. Three deck systems were considered in this study: ultra-high performance concrete (UHPC) deck, aluminum deck and UHPC-fiber reinforced polymer (FRP) tube deck. UHPC deck was the first alternative system developed as a part of this project. Due to its ultra high strength, this type of concrete results in thinner sections, which helps satisfy the strict self-weight limit. A comprehensive experimental and analytical evaluation of the system was carried out to establish its suitability. Both single and multi-unit specimens with one or two spans were tested for static and dynamic loading. Finite element models were developed to predict the deck behavior. The study led to the conclusion that the UHPC bridge deck is a feasible alternative to open grid steel deck. Aluminum deck was the second alternative system studied in this project. A detailed experimental and analytical evaluation of the system was carried out. The experimental work included static and dynamic loading on the deck panels and connections. Analytical work included detailed finite element modeling. Based on the in-depth experimental and analytical evaluations, it was concluded that aluminum deck was a suitable alternative to open grid steel decks and is ready for implementation. UHPC-FRP tube deck was the third system developed in this research. Prestressed hollow core decks are commonly used, but the proposed type of steel-free deck is quite novel. Preliminary experimental evaluations of two simple-span specimens, one with uniform section and the other with tapered section were carried out. The system was shown to have good promise to replace the conventional open grid decks. Additional work, however, is needed before the system is recommended for field application.
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This research focuses on developing active suspension optimal controllers for two linear and non-linear half-car models. A detailed comparison between quarter-car and half-car active suspension approaches is provided for improving two important scenarios in vehicle dynamics, i.e. ride quality and road holding. Having used a half-car vehicle model, heave and pitch motion are analyzed for those scenarios, with cargo mass as a variable. The governing equations of the system are analysed in a multi-energy domain package, i.e., 20-Sim. System equations are presented in the bond-graph language to facilitate calculation of energy usage. The results present optimum set of gains for both ride quality and road holding scenarios are the gains which has derived when maximum allowable cargo mass is considered for the vehicle. The energy implications of substituting passive suspension units with active ones are studied by considering not only the energy used by the actuator, but also the reduction in energy lost through the passive damper. Energy analysis showed less energy was dissipated in shock absorbers when either quarter-car or half-car controllers were used instead of passive suspension. It was seen that more energy could be saved by using half-car active controllers than the quarter-car ones. Results also proved that using active suspension units, whether quarter-car or half-car based, under those realistic limitations is energy-efficient and suggested.
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Peer reviewed
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Peer reviewed