82,249 research outputs found
Analyzing ethnic and cultural materials : insights into ELT materials
Ethnic and cultural materials and English Language Teaching (ELT) materials are related especially in terms of the emphasis on cultural knowledge and skills as well as the language and critical thinking skills. This study intends to research on ethnic and cultural materials within the perspectives of English language materials design. Specifically, the objectives of the study are to investigate the relevance and implications of such materials to ELT materials. The materials were selected from the content of Ethnic Relations course as it contained rich ethnic and cultural elements. When examining such materials from the perspectives of English language materials design, three aspects are considered: learner factors, text factors and task factors. The instrument used for the study was a checklist derived from works by Contazzi and Jin (2001), Nunan (2001), Tomlinson (2001) and Banks (1990). Basically, the checklist consists of 25 items and it was divided into three parts, learner factors, text factors, and task factors. The materials were analyzed using the checklist according to the specified criteria and the data obtained were represented in the form of description, examples and evidence. In addition, lecturers’ perceptions on the materials were attained using a set of interview questions. The findings indicate that a) ethnic and cultural materials have positive impacts on students’ interest and motivation, b) such materials include useful cultural elements and are comprehensible to students, and c) the tasks given are relevant and meaningful. The study also proves that lecturers dealing with ethnic and cultural contents are aware of the benefits of using such materials for teaching language and culture as it can foster critical thinking and develop communicative competence. Thus, the use of ethnic and cultural materials has a direct and significant implication to English language teaching and learning if the same criteria were to be applied when selecting and using ELT materials
All-frequency reflectionlessness
We derive planar permittivity profiles that do not reflect perpendicularly
exiting radiation of any frequency. The materials obey the Kramers-Kronig
relations and have no regions of gain. Reduction of the Casimir force by means
of such materials is also discussed.Comment: 7 page
On the survivability and detectability of terrestrial meteorites on the moon
Materials blasted into space from the surface of early Earth may preserve a unique record of our planet's early surface environment. Armstrong et al. (2002) pointed out that such materials, in the form of terrestrial meteorites, may exist on the Moon and be of considerable astrobiological interest if biomarkers from early Earth are preserved within them. Here, we report results obtained via the AUTODYN hydrocode to calculate the peak pressures within terrestrial meteorites on the lunar surface to assess their likelihood of surviving the impact. Our results confirm the order-of-magnitude estimates of Armstrong et al. (2002) that substantial survivability is to be expected, especially in the case of relatively low velocity (ca. 2.5 km/s) or oblique (≤45°) impacts, or both. We outline possible mechanisms for locating such materials on the Moon and conclude that searching for them would be a scientifically valuable activity for future lunar exploration
Magnetoelectricity at room temperature in Bi0.9-xTbxLa0.1FeO3 system
Magnetoelectric compounds with the general formula, Bi0.9-xRxLa0.1FeO3 (R
=Gd, Tb, Dy, etc.), have been synthesized. These show the coexistence of
ferroelectricity and magnetism, possess high dielectric constant and exhibit
magnetoelectric coupling at room temperature. Such materials may be of great
significance in basic as well as applied research.Comment: 11 pages of text and figure
To bend or not to bend – are heteroatom interactions within conjugated molecules effective in dictating conformation and planarity?
We consider the roles of heteroatoms (mainly nitrogen, the halogens and the chalcogens) in dictating the conformation of linear conjugated molecules and polymers through non-covalent intramolecular interactions. Whilst hydrogen bonding is a competitive and sometimes more influential interaction, we provide unambiguous evidence that heteroatoms are able to determine the conformation of such materials with reasonable predictability
Magnetic monopoles and unusual transport effects in magnetoelectrics
It is argued that in magnetoelectrics with diagonal magnetoelectric coupling
there should be a monopole-like distribution of magnetization around electric
charge. It may lead to nontrivial transport properties of such materials, to
understand which the picture of magnetic monopoles attached to electric charges
may be very useful.Comment: 6 pages, 4 fugure
An Evaluation of Faculty use of the Digital Library at Ankara University, Turkey
New consortial buying models have dramatically increased the availability of online resources, particularly journal articles, in the universities and technical institutes of developing countries. The degree of acceptance and pattern of use of such materials is of great interest to library collection development. Ankara University surveyed faculty members regarding their awareness and use of these electronic materials
A general method for the synthesis of nanostructured large-surface-area materials through the self-assembly of functionalized nanoparticles
A general synthetic method for the preparation of nanostructured materials with large surface area was developed by using nanoparticle building blocks. The preparation route involves the self-assembly of functionalized nanoparticles in a liquid-crystal phase. These nanoparticles are functionalized by using difunctional amino acid species to provide suitable interactions with the template. Optimum interactions for self-assembly of the nanoparticles in the liquid-crystal phase were achieved with one -NH2 group anchored to the nanoparticle surface per 25 Å2. To maximize the surface area of these materials, the wall thicknesses are adjusted so that they are composed of a monolayer of nanoparticles. To form such materials, numerous parameters have to be controlled such as the relative volume fraction of the nanoparticles and the template and size matching between the hydrophilic component of the copolymer and nanoparticles. The surface functionalization renders our synthetic route independent of the nanoparticles and allows us to prepare a variety of nanostructured composite materials that consist of a juxtaposition of different discrete oxide nanoparticles. Examples of such materials include CeO2, ZrO2, and CeO2–Al(OH)3 composites
Rhombohedral cubic semiconductor materials on trigonal substrate with single crystal properties and devices based on such materials
Growth conditions are developed, based on a temperature-dependent alignment model, to enable formation of cubic group IV, group II-V and group II-VI crystals in the [111] orientation on the basal (0001) plane of trigonal crystal substrates, controlled such that the volume percentage of primary twin crystal is reduced from about 40% to about 0.3%, compared to the majority single crystal. The control of stacking faults in this and other embodiments can yield single crystalline semiconductors based on these materials that are substantially without defects, or improved thermoelectric materials with twinned crystals for phonon scattering while maintaining electrical integrity. These methods can selectively yield a cubic-on-trigonal epitaxial semiconductor material in which the cubic layer is substantially either directly aligned, or 60 degrees-rotated from, the underlying trigonal material
- …