Re-using features of English as a foreign language (EFL) materials for special needs students of the same age group

This paper identifies a lack of age-appropriate literacy software for dyslexic teenagers in Irish classrooms and investigates the features of English as a Foreign Language (EFL) software that could be helpful to dyslexic students. There are often two distinct special learner groups within the same classroom: special needs students with reading difficulties in their native language and EFL students. While there are clear differences between these two groups, there is some overlap in their linguistic difficulties, e.g. spelling. There is a lack of age-appropriate software aimed at dyslexic teenagers; most software used is aimed at dyslexic children. However, a lot of materials are available for teenage EFL students. The paper discusses a survey of teenage dyslexic students and teachers/tutors of dyslexic teenagers, which identified student needs and desired features/exercises for curriculum-focused Computer-Assisted Language Learning (CALL) software for dyslexic students that the author is developing. Results show overlap of features and exercises present in existing EFL software

Exact treatment of ℓ≠0\ell \neq 0 states

Using the basic ingredient of supersymmetry, a general procedure for the treatment of quantum states having nonzero angular momenta is presented.Comment: 7 pages article in LaTEX (uses standard article.sty). No Figures. Accepted by Chinese Physics Letters (2004, vol 21. No.9

Testing the presence of multiple photometric components in nearby early-type galaxies using SDSS

We investigate two-dimensional image decomposition of nearby, morphologically selected early-type galaxies (ETGs). We are motivated by recent observational evidence of significant size growth of quiescent galaxies and theoretical development advocating a two-phase formation scenario for ETGs. We find that a significant fraction of nearby ETGs show changes in isophotal shape that require multi-component models. The characteristic sizes of the inner and outer component are $\sim 3$ and $\sim 15$ kpc. The inner component lies on the mass-size relation of ETGs at $z \sim 0.25-0.75$, while the outer component tends to be more elliptical and hints at a stochastic buildup process. We find real physical differences between the single- and double-component ETGs, with the double-component galaxies being younger and more metal-rich. The fraction of double component ETGs increases with increasing $\sigma$ and decreases in denser environments. We hypothesize that double-component systems were able to accrete gas and small galaxies until later times, boosting their central densities, building up their outer parts, and lowering their typical central ages. In contrast, the oldest galaxies, perhaps due to residing in richer environments, have no remaining hints of their last accretion episode.Comment: resubmitted to ApJ after referee's repor

Bouncing and cyclic string gas cosmologies

We show that, in the presence of a string gas, simple higher-derivative modifications to the effective action for gravity can lead to bouncing and cyclic cosmological models. The modifications bound the expansion rate and avoid singularities at finite times. In these models the scale factors can have long loitering phases that solve the horizon problem. Adding a potential for the dilaton gives a simple realization of the pre-big bang scenario. Entropy production in the cyclic phase drives an eventual transition to a radiation-dominated universe. As a test of the Brandenberger-Vafa scenario, we comment on the probability of decompactifying three spatial dimensions in this class of models.Comment: 35 pages, LaTeX, 9 figures. v2: additional references. v3: comments on Einstein frame, version to appear in PR

Development and Analysis of the Automated Object Reentry Survival Analysis Tool Parametric Study Wrapper

The NASA Orbital Debris Program Office (ODPO) studies all aspects of spacecraft end-of-life and orbital debris measurement, modeling, and mitigation. The reentry safety group within the ODPO uses the Object Reentry Survival Analysis Tool (ORSAT) to calculate the casualty risk due to reentry of spacecraft and other types of orbital debris. ORSAT models spacecraft as a collection of fragments that break apart from the parent object at a pre-defined breakup altitude. It then calculates the trajectory and aero-heating of these fragments to determine which fragments are completely destroyed and which survive to the ground and pose a risk to human population. Because of the historically high computational cost of these calculations, many simplifying assumptions have been made in the traditional calculation and analysis process used by the ODPO, some of which have been shown by recent research by the ODPO and others to be incorrect. Improvements to the ORSAT code and advancements in computer technology have vastly decreased the programs processing time, and have allowed the ODPO to develop a capability for large-scale parametric studies and Monte Carlo reentry simulations that can aid in both the initial spacecraft design and provide more detailed and accurate risk analysis to spacecraft operators

Green's Functions and the Adiabatic Hyperspherical Method

We address the few-body problem using the adiabatic hyperspherical representation. A general form for the hyperangular Green's function in $d$-dimensions is derived. The resulting Lippmann-Schwinger equation is solved for the case of three-particles with s-wave zero-range interactions. Identical particle symmetry is incorporated in a general and intuitive way. Complete semi-analytic expressions for the nonadiabatic channel couplings are derived. Finally, a model to describe the atom-loss due to three-body recombination for a three-component fermi-gas of $^{6}$Li atoms is presented.Comment: 14 pages, 8 figures, 2 table

Three-Body Recombination in One Dimension

We study the three-body problem in one dimension for both zero and finite range interactions using the adiabatic hyperspherical approach. Particular emphasis is placed on the threshold laws for recombination, which are derived for all combinations of the parity and exchange symmetries. For bosons, we provide a numerical demonstration of several universal features that appear in the three-body system, and discuss how certain universal features in three dimensions are different in one dimension. We show that the probability for inelastic processes vanishes as the range of the pair-wise interaction is taken to zero and demonstrate numerically that the recombination threshold law manifests itself for large scattering length.Comment: 15 pages 7 figures Submitted to Physical Review