AdS (In)stability: Lessons From The Scalar Field

We argued in arXiv:1408.0624 that the quartic scalar field in AdS has features that could be instructive for answering the gravitational stability question of AdS. Indeed, the conserved charges identified there have recently been observed in the full gravity theory as well. In this paper, we continue our investigation of the scalar field in AdS and provide evidence that in the Two-Time Formalism (TTF), even for initial conditions that are far from quasi-periodicity, the energy in the higher modes at late times is exponentially suppressed in the mode number. Based on this and some related observations, we argue that there is no thermalization in the scalar TTF model within time-scales that go as $\sim 1/\epsilon^2$, where $\epsilon$ measures the initial amplitude (with only low-lying modes excited). It is tempting to speculate that the result holds also for AdS collapse.Comment: 10 pages, 4 figure

Localised Laryngeal Amyloidosis Endoscopic Excision -A Case Report

Abstract:We report a case of primary laryngeal amyloidosis in a 35 year old adult patient who presented with hoarseness of voice for 6 months duration with no other symptoms. Patient was treated successfully with endoscopic excision using a microdebrider with a laryngeal blade and review of literature.Keywords: laryngeal amyloid .  Endoscopy . Debrider

IMPACT OF INTERNET IN ACADEMIC EFFICIENCY OF STUDENTS AMONG ENGINEERING GRADUATES

In the modern digital world, Internet service play a crucial role in enriching new trends among young graduates. Internet have empowered new technology to young learners to progress their academic work. It is very essential to measure the impact of internet service among engineering graduates which paved the way for higher studies and employment. Digital era may oblige to learn everything in their routine life with new techniques. In this study, questionnaire is structured and issued to 180 engineering graduates around 3 colleges in Tirunelveli district. Out of 180, 164 responded and get collected. After analyzing , we came to know that 44.43 % of the respondent have strongly agree the positive impact in their academic way. In turn, 41.29% of the respondent have strongly agree the negative impact in their academic way

Photoemission Studies of Magnetic Systems.

I have studied the electronic structure of thin films by photoelectron spectroscopy. My results show that even a monolayer film of Ni/Cu(001) exhibits bulk-like electronic structure and resembles that of bulk Ni. In order to better understand this result, I tracked the sp-band dimension at the Fermi surface of the Ni films for various coverages. For submonolayer coverages of Ni, the sp-band dimension was smaller than that of bulk Cu, but quickly reached that of bulk Ni by 1.2 ML Ni coverage. This continuous decrease implies a charge transfer from the Cu substrate to the Ni film, resulting in a decrease in the filling of the Cu sp-band. This transfer of electronic charge could provide a mechanism for hybridization at the Cu/Ni interface and result in a larger penetration of the film electronic states into the substrate. To quantify the charge transfer, the reverse system of Cu/Ni(001) was studied. Again the sp-band dimension for 45 eV photons was studied as a function of Cu thickness. The change in the sp-band dimension was related to reduced filling in the sp-band of bulk Cu. This corresponded to a reduction of $\sim$0.5 eV in the band-filling of bulk Cu. From the integrated density of states, this was identified to be a charge depletion of $\sim$0.12 electrons/atom for the monolayer film. This shift was observed in core level spectra across the 3p levels, corroborating the assumption

Development of biomaterial scaffold for nerve tissue engineering: Biomaterial mediated neural regeneration

Neural tissue repair and regeneration strategies have received a great deal of attention because it directly affects the quality of the patient's life. There are many scientific challenges to regenerate nerve while using conventional autologous nerve grafts and from the newly developed therapeutic strategies for the reconstruction of damaged nerves. Recent advancements in nerve regeneration have involved the application of tissue engineering principles and this has evolved a new perspective to neural therapy. The success of neural tissue engineering is mainly based on the regulation of cell behavior and tissue progression through the development of a synthetic scaffold that is analogous to the natural extracellular matrix and can support three-dimensional cell cultures. As the natural extracellular matrix provides an ideal environment for topographical, electrical and chemical cues to the adhesion and proliferation of neural cells, there exists a need to develop a synthetic scaffold that would be biocompatible, immunologically inert, conducting, biodegradable, and infection-resistant biomaterial to support neurite outgrowth. This review outlines the rationale for effective neural tissue engineering through the use of suitable biomaterials and scaffolding techniques for fabrication of a construct that would allow the neurons to adhere, proliferate and eventually form nerves

Bounding the Optimal Length of Pliable Index Coding via a Hypergraph-based Approach

In pliable index coding (PICOD), a number of clients are connected via a noise-free broadcast channel to a server which has a list of messages. Each client has a unique subset of messages at the server as side-information and requests for any one message not in the side-information. A PICOD scheme of length $\ell$ is a set of $\ell$ encoded transmissions broadcast from the server such that all clients are satisfied. Finding the optimal (minimum) length of PICOD and designing PICOD schemes that have small length are the fundamental questions in PICOD. In this paper, we use a hypergraph-based approach to derive new achievability and converse results for PICOD. We present an algorithm which gives an achievable scheme for PICOD with length at most $\Delta(\mathcal{H})$, where $\Delta(\mathcal{H})$ is the maximum degree of any vertex in a hypergraph that represents the PICOD problem. We also give a lower bound for the optimal PICOD length using a new structural parameter associated with the PICOD hypergraph called the nesting number. We extend some of our results to the PICOD problem where each client demands $t$ messages, rather than just one. Finally, we identify a class of problems for which our converse is tight, and also characterize the optimal PICOD lengths of problems with $\Delta(\mathcal{H})\in\{1,2,3\}$.Comment: Accepted at the IEEE Information Theory Workshop, 202

Quasi-static Compression of Granular Materials (Sand) at High Pressures (~ 3 Gpa)

This investigation presents the results on the static behavior of confined sand (from Eglin Air Force Base) subjected to axial compressive stresses up to 3 GPa. A self-aligning compression fixture was developed to statically compress sand specimen in a cylindrical steel confinement using tungsten carbide pins. A strain gage was mounted on the confining cylinder to measure the circumferential strain. Using axial stress, axial strain, and hoop strain the multi axial behavior of the confined sand is investigated. Compressive tests were conducted up to axial strains of 35%. The static response of the dry sand was tested at four different initial densities, namely, 1.55, 1.60, 1.65, and 1.75~g/cm$^3$. Effects of particle size, primarily classified as coarse and fine, were investigated. The effect of moisture was also investigated at four different degrees of saturation, namely, 0%, 20%, 40%, and 100%. The dense sand provided a much stiffer response than the loosely packed ones. The coarse sand grains showed significant crushing of particles followed by compaction of the powdered grains.Mechanical & Aerospace Engineerin