An Evaluation of the Textbook English 6: A case study from secondary schools in the Mekong Delta Provinces of Vietnam

The present study evaluates English 6, an official textbook used for grade 6 pupils in all secondary schools all over Vietnam, in the teaching and learning context of the Mekong Delta. The research was conducted in two stages: a theoretical evaluation and an empirical evaluation. The theoretical evaluation was based on the researcher’s experience, expertise, and the literature on textbook evaluation. The empirical evaluation was based on data collected from 22 teachers and 313 pupils at 8 different secondary schools in four different provinces in the Mekong Delta in the form of questionnaires, semi-structured interviews, documents and classroom observation. The evaluation sought to find out the users’ views on the textbook, its impact on users and the users’ recommendations for improvement. The results of the evaluation show that the textbook • suits the teaching and learning context and culture, • gives much help to both teachers and pupils, • receives positive responses from teachers and pupils. Beside these merits, the textbook needs to be improved in the following ways: • More varied types of activities, especially ones which help pupils practice using the target language communicatively, should be added to the textbook content. • Free practice activities should be added after the controlled ones to help pupils practice speaking and writing creatively. • The textbook should be supplemented with language material from different resources such as picture stories, comic strips, etc. • The supporting resources need to be more widely available and better, both in terms of physical appearance and quality. The findings also indicate that textbook writers should carry out learner needs analysis before writing new textbooks to make sure they meet learners’ needs

On the Perturbative Nature of Color Superconductivity

Color superconductivity is a possible phase of high density QCD. We present a systematic derivation of the transition temperature, T_C, from the QCD Lagrangian through study of the di-quark proper vertex. With this approach, we confirm the dependence of T_C on the coupling g, namely $T_C \sim \mu g^{-5} e^{-\kappa/g}$, previously obtained from the one-gluon exchange approximation in the superconducting phase. The diagrammatic approach we employ allows us to examine the perturbative expansion of the vertex and the propagators. We find an additional O(1) contribution to the prefactor of the exponential from the one-loop quark self energy and that the other one-loop radiative contributions and the two gluon exchange vertex contribution are subleading.Comment: 13 pages, 3 figures, revtex, details and discussion expande

The Radion in the Karch-Randall Braneworld

In a braneworld context, the radion is a massless mode coupling to the trace of the matter stress tensor. Since the radion also governs the separation between branes, it is expected to decouple from the physical spectrum in single brane scenarios, such as the one-brane Randall-Sundrum model. However, contrary to expectations, we demonstrate that the Karch-Randall radion always remains as a physical excitation, even in the single brane case. Here, the radion measures the distance not between branes, but rather between the brane and the anti-de Sitter boundary on the other side of the bulk.Comment: 19 pages, Plain Te

The radiative lepton flavor violating decays in the split fermion scenario in the two Higgs doublet model

We study the branching ratios of the lepton flavor violating processes \mu -> e \gamma, \tau -> e \gamma and \tau -> \mu\gamma in the split fermion scenario, in the framework of the two Higgs doublet model. We observe that the branching ratios are relatively more sensitive to the compactification scale and the Gaussian widths of the leptons in the extra dimensions, for two extra dimensions and especially for the \tau -> \mu \gamma decay.Comment: 19 pages, 7 Figure

Vibration characteristics of a large wind turbine tower on non-rigid foundations

Vibration characteristics of the Mod-OA wind turbine supported by nonrigid foundations were investigated for a range of soil rigidities. The study shows that the influence of foundation rotation on the fundamental frequency of the wind turbine is quite significant for cohesive soils or loose sand. The reduction in natural frequency can be greater than 20 percent. However, for a foundation resting on well graded, dense granular materials or bedrock, such effect is small and the foundation can be treated as a fixed base

The Ginzburg-Landau Free Energy Functional of Color Superconductivity at Weak Coupling

We derive the Ginzburg-Landau free energy functional of color superconductivity in terms of the thermal diagrams of QCD in its perturbative region. The zero mode of the quadratic term coefficient yields the same transition temperature, including the pre-exponential factor, as the one obtained previously from the Fredholm determinant of the two quark scattering amplitude. All coefficients of the free energy can be made identical to those of a BCS model by setting the Fermi velocity of the latter equal to the speed of light. We also calculate the induced symmetric color condensate near $T_c$ and find that it scales as the cubic power of the dominant antisymmetric color component. We show that in the presence of an inhomogeneity and a nonzero gauge potential, while the color-flavor locked condensate dominates in the bulk, the unlocked condensate, the octet, emerges as a result of a simultaneous color-flavor rotation in the core region of a vortex filament or at the junction of super and normal phases.Comment: 32 pages, Plain Tex, 3 figure