Fragile identities: Exploring learner identity, learner autonomy and motivation through young learners’ voices

Recent research in the fields of motivation and learner autonomy in language learning has begun to explore their relationships to the construct of identity. This article builds on this through the voices of a group of six learners of French or German in a secondary school in England, over a two-year period. These young learners initially reveal a clear identity as learners responsible for and able to take control of their own learning. However, this identity is seen as fragile when teacher control is increased in response to the external pressure of examinations, and there are indications of loss of motivation. Secondary school teachers, therefore, need to ensure that the learning environment they create engages, nurtures, and protects their learners‟ identity as learners through sustained opportunities for autonomy. Further research is proposed into aspects of learner identity, as well as ways in which changing pedagogy involves changes in teacher identity. Des études récentes dans les domaines de la motivation et de l‟autonomie de l‟apprenant des langues explorent les relations entre ces deux domaines et l‟identité de l‟apprenant. Cet article contribue à ces recherches, en examinant pendant une période de deux ans la voix d'un groupe de six jeunes qui apprennent le français ou l‟allemand dans une école secondaire en Angleterre. Ces jeunes apprenants révèlent au début une identité claire en tant qu‟apprenants responsables pour et capables de contrôler leur propre apprentissage. Cependant on voit que cette identité est fragile quand le contrôle de l‟enseignant est augmenté face à la pression externe des examens, menant potentiellement a une perte de motivation. Les professeurs du secondaire devraient donc créer un milieu d'apprentissage capable d‟engager, de développer et de protéger l‟identité des apprenants en tant qu'apprenants, en assurant qu‟ils peuvent continuer à jouir des opportunités pour l‟autonomie. Des recherches futures sont proposées sur des aspects de l‟identité des apprenants, et aussi sur les implications des changements de pédagogie pour l‟identité des professeurs

Language associations and collaborative support: language teacher associations as empowering spaces for professional networks

The LACS project (Language Associations and Collaborative Support) marked the first major cooperation between the European Centre for Modern Languages (ECML) and the Fe ́de ́ration Internationale des Professeurs de Langues Vivantes/ International Federation of Language Teacher Associations (FIPLV). This article focuses on one aspect of the project, namely an exploration of issues affecting language teacher associations worldwide. It describes the research carried out into the associations’ perceptions of their functions, the challenges they face and the strategies they are employing to address these challenges. Following an explora- tion of related literature, which provided a framework for analysis, the article describes the research methodology employed and then presents and discusses the data. In response to the challenges of sustaining membership and influencing policy, language teacher associations are seen to be developing new spaces, in which multidimensional networks can develop, and which can be of continuing relevance both internally to members and to external bodies. The article concludes by drawing on theories of space, arguing that it is through the shift from normative structures to more dynamic and flexible networks and spaces that associations are learning to cope with changes in the nature of professionalism associated with postmodernity

Logistics hardware and services control system

Software system permits onsite direct control of logistics operations, which include spare parts, initial installation, tool control, and repairable parts status and control, through all facets of operations. System integrates logistics actions and controls receipts, issues, loans, repairs, fabrications, and modifications and assets in predicting and allocating logistics parts and services effectively

Origin of intermittent accretion-powered X-ray oscillations in neutron stars with millisecond spin periods

We have shown previously that many of the properties of persistent accretion-powered millisecond pulsars can be understood if their X-ray emitting areas are near their spin axes and move as the accretion rate and structure of the inner disk vary. Here we show that this "nearly aligned moving spot model" may also explain the intermittent accretion-powered pulsations that have been detected in three weakly magnetic accreting neutron stars. We show that movement of the emitting area from very close to the spin axis to about 10 degrees away can increase the fractional rms amplitude from less than about 0.5 percent, which is usually undetectable with current instruments, to a few percent, which is easily detectable. The second harmonic of the spin frequency usually would not be detected, in agreement with observations. The model produces intermittently detectable oscillations for a range of emitting area sizes and beaming patterns, stellar masses and radii, and viewing directions. Intermittent oscillations are more likely in stars that are more compact. In addition to explaining the sudden appearance of accretion-powered millisecond oscillations in some neutron stars with millisecond spin periods, the model explains why accretion-powered millisecond oscillations are relatively rare and predicts that the persistent accretion-powered millisecond oscillations of other stars may become undetectable for brief intervals. It suggests why millisecond oscillations are frequently detected during the X-ray bursts of some neutron stars but not others and suggests mechanisms that could explain the occasional temporal association of intermittent accretion-powered oscillations with thermonuclear X-ray bursts.Comment: 5 pages, 1 figure; includes additional discussion and updated references; accepted for publication in ApJ

A Unified Jet Model of X-Ray Flashes, X-Ray-Rich Gamma-Ray Bursts, and Gamma-Ray Bursts: I. Power-Law-Shaped Universal and Top-Hat-Shaped Variable Opening-Angle Jet Models

HETE-2 has provided strong evidence that the properties of X-Ray Flashes (XRFs), X-ray-rich GRBs, and GRBs form a continuum, and therefore that these three kinds of bursts are the same phenomenon. A key feature found by HETE-2 is that the density of bursts is roughly constant per logarithmic interval in burst fluence S_E and observed spectral peak energy Ep_obs, and in isotropic-equivalent energy Eiso and rest frame spectral peak energy Epeak. In this paper, we explore a unified jet model of all three kinds of bursts, using population synthesis simulations of the bursts and detailed modeling of the instruments that detect them. We show that both a variable jet opening-angle model in which the emissivity is a constant independent of the angle relative to the jet axis and a universal jet model in which the emissivity is a power-law function of the angle relative to the jet axis can explain the observed properties of GRBs reasonably well. However, if one tries to account for the properties of all three kinds of bursts in a unified picture, the extra degree of freedom available in the variable jet opening-angle model enables it to explain the observations reasonably well while the power-law universal jet model cannot. The variable jet opening-angle model of XRFs, X-ray-rich GRBs, and GRBs implies that the energy Egamma radiated in gamma rays is ~ 100 times less than has been thought, and that most GRBs have very small jet opening angles (~ half a degree). It also implies that there are ~ 10^4 - 10^5 more bursts with very small jet opening angles for every burst that is observable. If this is the case, the rate of GRBs could be comparable to the rate of Type Ic core collapse supernovae.Comment: 51 pages, 19 figures, accepted by ApJ; revised; condensed abstrac

Likelihood Analysis of GRB Evolution with Redshift

We present a likelihood approach to modeling multi-dimensional GRB Epeak--fluence--redshift data that naturally incorporates instrument detection thresholds. The treatment of instrument thresholds is essential for analyzing evidence for GRB evolution. The method described here compares the data to a uniform jet model, in which the jet parameters are allowed to vary with redshift. Data from different experiments may be modeled jointly. In addition, BATSE data (for which no redshift information is available) may be incorporated by ascribing to each event a likelihood derived from the full model by integrating the probability density over the unknown redshift. The loss of redshift information is mitigated by the large number of available bursts. We discuss the implementation of the method, and validation of it using simulated data.Comment: 4 pages, 1 figure. Poster presented at the 4th Workshop Gamma-Ray Bursts in the Afterglow Era, Rome,18-22 October 2004. Editors: L. Piro, L. Amati, S. Covino, and B. Gendre. Il Nuovo Cimento, in pres

Helical motion of magnetic flux tubes in the solar atmosphere

Photospheric granulation may excite transverse kink pulses in anchored vertical magnetic flux tubes. The pulses propagate upwards along the tubes with the kink speed, while oscillating wakes are formed behind the wave front in a stratified atmosphere. The wakes oscillate at the kink cut-off frequency of stratified medium and gradually decay in time. When two or more consecutive kink pulses with different polarizations propagate in the same thin tube, then the wakes corresponding to different pulses may superimpose. The superposition sets up helical motions of magnetic flux tubes in the photosphere/chromosphere as seen by recent Hinode movies. The energy carried by the pulses is enough to heat the solar chrmosphere/corona and accelerate the solar wind.Comment: Accepted in ApJ

Gamma-Ray Burst Jet Profiles And Their Signatures

HETE-II and BeppoSAX have produced a sample of GRBs and XRFs with known redshifts and $E_{pk}$. This sample provides four important empirical constraints on the nature of the source jets: Log $E_{iso}$ is approximately uniformly distributed over several orders of magnitude; the inferred prompt energy Log $E_{\gamma}$ is narrowly distributed; the Amati relation holds between $E_{iso}$ and $E_{pk}$; and the Ghirlanda relation holds between $E_{\gamma}$ and $E_{pk}$. We explore the implications of these constraints for GRB jet structure during the prompt emission phase. We infer the underlying angular profiles from the first two of the above constraints assuming all jets have the same profile and total energy, and show that such ``universal jet'' models cannot satisfy both constraints. We introduce a general and efficient method for calculating relativistic emission distributions and $E_{pk}$ distributions from jets with arbitrary (smooth) angular jet profiles. We also exhibit explicit analytical formulas for emission from top-hat jets (which are not smooth). We use these methods to exhibit $E_{pk}$ and $E_{iso}$ as a function of viewing angle, for several interesting families of GRB jet profiles. We use the same methods to calculate expected frequency distributions of $E_{iso}$ and $E_{\gamma}$ for the same families of models. We then proceed to explore the behavior of universal jet models under a range of profile shapes and parameters, to map the extent to which these models can conform to the above four empirical constraints.Comment: 71 page, 33 figures. Submitted to Ap

Development of microwave NDT inspection techniques for large solid propellant rocket motors Final report

Microwave nondestructive testing techniques for large solid propellant rocket engine