Effect of high-K dielectrics on charge transport in graphene

The effect of various dielectrics on charge mobility in single layer graphene is investigated. By calculating the remote optical phonon scattering arising from the polar substrates, and combining it with their effect on Coulombic impurity scattering, a comprehensive picture of the effect of dielectrics on charge transport in graphene emerges. It is found that though high-$\kappa$ dielectrics can strongly reduce Coulombic scattering by dielectric screening, scattering from surface phonon modes arising from them wash out this advantage. By comparing the room-temperature transport properties with narrow-bandgap III-V semiconductors, strategies to improve the mobility in single layer graphene are outlined.Comment: 6 pages, 4 Figure

Nature human Interface:An Ecocritical Study of Anita Desai’s Fire on the Mountain

The idea of distinction or conflict between nature and human being is possibly the result of scientific prudence. Progress in science and technology develops the idea of nature as a mechanical system which may be used and exploited in the process of satisfying human desires. It results in the acceleration of changes in the balance of the environment. Thus, it is the need of the twentyfirst century to explore the primordial relation of human with nature in science and philosophy, history and literature, perhaps the main objective is to save it. Again human dependence on environment for instrumental as well as intrinsic purpose is undeniable and ubiquitous. In the process of searching for fulfillment amidst desperation, human being finds nature as probably a suitable space. This paper makes an attempt to study how nature plays vital role in reshaping and restructuring human life as well as how human developmental practices (both scientific and cultural) corrupt and desecrate the environment. Moreover, it carries out the study of Anita Desai's Fire on the Mountain, in the backdrop of Ecocritical ideas, in order to justify Desai's vision of nature and its relationship with the human in the novel

Reinventing the Cultural History of Colonial Odisha through Creative Nonfiction: A Study of J.P Das's A Time Elsewhere

Historical fictions and narrating the historical facts through creative nonfiction are different concepts, as in the former the details are fictionalised with the imaginative dialogues and events and in the later the historical facts are presented in a creative way that does not affect or disturb the authenticity of the facts. Here the epithet "Creative" refers to the use of literary techniques and novelistic narrative modes to tell the "true stories" or the factually accurate prose and does not mean the narration of imaginary events and the nonexistent things1. It is true that history in an objective way details the significant events with utmost exactness. So the question comes while narrating the history in a creative way will not the creative process interfere with the facts? Again, in the process of analysis and interpretation of facts to narrate, the personal ideological bias of the author may be implicitly present in the text and the narrative takes the way as the author intends; for which the reliability on the factuality of the presented facts will be in doubt. The central concern of this paper is to study J P Das's A Time Elsewhere to explore how the cultural history of Orissa has been presented with factual accurateness of events, creativity and the cardinal principles of History writing, moreover to study the aforementioned writing as creative nonfiction

Effect of size and dimensionality on the magnetic moment of transition metals

The effect of size and dimensionality on the magnetic moments of Fe, Co, and Ni have been studied theoretically by confining the atoms to various structural forms such as chains, surfaces, and thin films. The size of these systems is controlled by limiting the number of atoms. A new first‐principles theory is developed that enables us to study the electron spin density of states and moments of atoms in clusters containing two to a few thousand atoms. The theory is based upon the elementary principles governing the tight binding and linear combination of atomic orbitals formulations. It contains no adjustable parameters and can be applied to systems with or without topological symmetry. We have discovered quantum size effects on the magnetic moments of linear chains and these effects disappear when the chains contain more than 20 atoms. We have also found distinct effects of the local environment on the magnetic moment. For example, the moments increase with decreasing coordination number and increasing interatomic distance. Our results will be compared with available experimental and theoretical results

Giant Magnetic Moments of Nitrogen Stabilized Mn Clusters and Their Relevance to Ferromagnetism in Mn Doped GaN

Using first principles calculations based on density functional theory, we show that the stability and magnetic properties of small Mn clusters can be fundamentally altered by the presence of nitrogen. Not only are their binding energies substantially enhanced, but also the coupling between the magnetic moments at Mn sites remains ferromagnetic irrespective of their size or shape. In addition, these nitrogen stabilized Mn clusters carry giant magnetic moments ranging from 4 Bohr magnetons in MnN to 22 Bohr magnetons in Mn_5N. It is suggested that the giant magnetic moments of Mn_xN clusters may play a key role in the ferromagnetism of Mn doped GaN which exhibit a wide range (10K - 940K) of Curie temperatures

Application of surgical periodontics for accelerated orthodontic correction of class ll division l malocclusion with skeletal discrepancy

Background: There is a constant pursuit for substituting orthognathic surgical options by minimally invasive pre-orthodontic surgical procedures. Application of osseous resective surgery for alveolar reshaping is referred to here as "surgical periodontics for accelerated orthodontics". A parallel randomized clinical trial was designed to evaluate the clinical outcome of class 2 division 1 malocclusion with skeletal discrepancy using pre-orthodontic surgical procedures, comparing periodontally accelerated osteogenic orthodontics with surgical periodontics for accelerated orthodontics.Methods: Twenty-four adult orthodontics patients selected for this study were randomly divided into 2 equal groups. One group was treated with periodontally accelerated osteogenic orthodontics with augmentation grafting and the other was with surgical periodontics for accelerated orthodontics. These procedures were followed by fixed orthodontics treatment. Comparative evaluation of alveolar bone thickness was done by cone beam computed tomogram for both the groups.Results: The cephalometric parameters, A point nasion B point (ANB) angle and over jet of these subjects before and after the surgical interventions at three, six and twelve month’s intervals were compared to the base values, showing changes within 3 months when treated with surgical periodontics for accelerated orthodontics and within 6 months when treated with periodontally accelerated osteogenic orthodontics, without significant change in periodontal supporting alveolar bone thickness.Conclusions: Surgical periodontics for accelerated orthodontics and periodontally accelerated osteogenic orthodontics are effective pre-orthodontics surgical procedures for accelerating orthodontic treatment, without bringing any change in periodontal alveolar bone thickness