1000 resultados para Benn, S.I


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We present new spectroscopic and photometric data of the Type Ibn supernovae 2006jc, 2000er and 2002ao. We discuss the general properties of this recently proposed supernova family, which also includes SN 1999cq. The early-time monitoring of SN 2000er traces the evolution of this class of objects during the first few days after the shock breakout. An overall similarity in the photometric and spectroscopic evolution is found among the members of this group, which would be unexpected if the energy in these core-collapse events was dominated by the interaction between supernova ejecta and circumstellar medium. Type Ibn supernovae appear to be rather normal Type Ib/c supernova explosions which occur within a He-rich circumstellar environment. SNe Ibn are therefore likely produced by the explosion of Wolf-Rayet progenitors still embedded in the He-rich material lost by the star in recent mass-loss episodes, which resemble known luminous blue variable eruptions. The evolved Wolf-Rayet star could either result from the evolution of a very massive star or be the more evolved member of a massive binary system. We also suggest that there are a number of arguments in favour of a Type Ibn classification for the historical SN 1885A (S-Andromedae), previously considered as an anomalous Type la event with some resemblance to SN 1991bg.

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Experiencia en un IES de Mallorca sobre la atenci??n a la diversidad para alumnos con tetraplegia esp??stica. A trav??s de esta experiencia se facilita el acceso al curriculum y se favorecen las capacidades de relaci??n interpersonal para ayudar a la formaci??n de la identidad personal de adolescentes con esta discapacidad.

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La present tesi consisteix en un recull toponímic pretèrit i present del terme d'Osor, comarca de la Selva a les Guilleries. S'hi recullen prop de 3600 noms de lloc recollits oralment o en documentació antiga sobre els quals s'hi realitza una situació, un recull documental, un estudi gràfic i una hipòtesi etimològica. A més a més, s'hi presenta la situació geogràfica (quan és possible) dins l'espai treballat, un estudi del topònim Osor, una mostra dels estudis onomàstics de les comarques gironines, un estudi de genèrics introductors dels topònims de l'estudi, una classificació semàntica dels termes recollits i diversos mapes de situació. Evidentment, s'hi presenta l'etimologia seguida, unes conclusions finals i una àmplia bibliografia a més de dos annexos, un dels llinatges d'Osor en el decurs de la història i un altre amb els malnoms recollits per entrevista oral o documentació antiga.

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The measurement of Cobb angles from radiographs is routine practice in spinal clinics. The technique relies on the use and availability of specialist equipment such as a goniometer, cobbometer or protractor. The aim of this study was to validate the use of i-Phone (Apple Inc) combined with Tilt Meter Pro software as compared to a protractor in the measurement of Cobb angles. Between November 2008 and December 2008 20 patients were selected at random from the Paediatric Spine Research Groups Database. A power calculation was performed which indicated if n=240 measurements the study had a 96% chance of detecting a 5 degree difference between groups. All patients had idiopathic scoliosis with a range of curve types and severities. The study found the i-Phone combined with Tilt Meter Pro software offers a faster alternative to the traditional method of Cobb angle measurement. The use of i-Phone offers a more convenient way of measuring Cobb angles in the outpatient setting. The intra-observer repeatability of the iPhone is equivalent to the protractor in the measurement of Cobb angles.

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CFO and I/Q mismatch could cause significant performance degradation to OFDM systems. Their estimation and compensation are generally difficult as they are entangled in the received signal. In this paper, we propose some low-complexity estimation and compensation schemes in the receiver, which are robust to various CFO and I/Q mismatch values although the performance is slightly degraded for very small CFO. These schemes consist of three steps: forming a cosine estimator free of I/Q mismatch interference, estimating I/Q mismatch using the estimated cosine value, and forming a sine estimator using samples after I/Q mismatch compensation. These estimators are based on the perception that an estimate of cosine serves much better as the basis for I/Q mismatch estimation than the estimate of CFO derived from the cosine function. Simulation results show that the proposed schemes can improve system performance significantly, and they are robust to CFO and I/Q mismatch.

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There is much still to learn about how young children’s membership with peers shapes their constructions of moral and social obligations within everyday activities in the school playground. This paper investigates how a small group of girls, aged four to six years, account for their everyday social interactions in the playground. They were video-recorded as they participated in a pretend game of school. Several days later, a video-recorded excerpt of the interaction was shown to them and invited to comment on what was happening in the video. This conversation was audio-recorded. Drawing on a conversation analysis approach, this chapter shows that, despite their discontent and complaining about playing the game of school, the girls’ actions showed their continued orientation to the particular codes of the game, of ‘no going away’ and ‘no telling’. By making relevant these codes, jointly constructed by the girls during the interview, they managed each other’s continued participation within two arenas of action: the pretend, as a player in a pretend game of school; and the real, as a classroom member of a peer group. Through inferences to explicit and implicit codes of conduct, moral obligations were invoked as the girls attempted to socially exclude or build alliances with others, and enforce their own social position. As well, a shared history that the girls re-constructed has moral implications for present and future relationships. The girls oriented to the history as an interactional resource for accounting for their actions in the pretend game. This paper uncovers how children both participate in, and shape, their everyday social worlds through talk and interaction and the consequences a taken-for-granted activity such as playing school has for their moral and social positions in the peer group.

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This paper aims to develop the methodology and strategy for concurrent finite element modeling of civil infrastructures at the different scale levels for the purposes of analyses of structural deteriorating. The modeling strategy and method were investigated to develop the concurrent multi-scale model of structural behavior (CMSM-of-SB) in which the global structural behavior and nonlinear damage features of local details in a large complicated structure could be concurrently analyzed in order to meet the needs of structural-state evaluation as well as structural deteriorating. In the proposed method, the “large-scale” modeling is adopted for the global structure with linear responses between stress and strain and the “small-scale” modeling is available for nonlinear damage analyses of the local welded details. A longitudinal truss in steel bridge decks was selected as a case to study how a CMSM-of-SB was developed. The reduced-scale specimen of the longitudinal truss was studied in the laboratory to measure its dynamic and static behavior in global truss and local welded details, while the multi-scale models using constraint equations and substructuring were developed for numerical simulation. The comparison of dynamic and static response between the calculated results by different models indicated that the proposed multi-scale model was found to be the most efficient and accurate. The verification of the model with results from the tested truss under the specific loading showed that, responses at the material scale in the vicinity of local details as well as structural global behaviors could be obtained and fit well with the measured results. The proposed concurrent multi-scale modeling strategy and implementation procedures were applied to Runyang cable-stayed bridge (RYCB) and the CMSM-of-SB of the bridge deck system was accordingly constructed as a practical application.