Gravity and Large Extra Dimensions

The idea that quantum gravity can be realized at the TeV scale is extremely attractive to theorists and experimentalists alike. This proposal leads to extra spacial dimensions large compared to the electroweak scale. Here we give a very systematic view of the foundations of the theories with large extra dimensions and their physical consequences.Comment: 26 pages, 3 diagram

Supernovae as Probes of Extra Dimensions

Since the dawn of the new millennium, there has been a revived interest in the concept of extra dimensions.In this scenario all the standard model matter and gauge fields are confined to the 4 dimensions and only gravity can escape to higher dimensions of the universe.This idea can be tested using table-top experiments, collider experiments, astrophysical or cosmological observations. The main astrophysical constraints come from the cooling rate of supernovae, neutron stars, red giants and the sun. In this article, we consider the energy loss mechanism of SN1987A and study the constraints it places on the number and size of extra dimensions and the higher dimensional Planck scale.Comment: 5 pages, no figures, new references are adde

Efficacy of atmospheric pressure dielectric barrier discharge for inactivating airborne pathogens

Atmospheric pressure plasmas have gained attention in recent years for several environmental applications. This technology could potentially be used to deactivate airborne microorganisms, surface-bound microorganisms, and biofilms. In this work, the authors explore the efficacy of the atmospheric pressure dielectric barrier discharge (DBD) to inactivate airborne Staphylococcus epidermidis and Aspergillus niger that are opportunistic pathogens associated with nosocomial infections. This technology uses air as the source of gas and does not require any process gas such as helium, argon, nitrogen, or hydrogen. The effect of DBD was studied on aerosolized S. epidermidis and aerosolized A. niger spores via scanning electron microscopy (SEM). The morphology observed on the SEM micrographs showed deformations in the cellular structure of both microor- ganisms. Cell structure damage upon interaction with the DBD suggests leakage of vital cellular materials, which is a key mechanism for microbial inactivation. The chemical structure of the cell surface of S. epidermidis was also analyzed by near edge x-ray absorption fine structure spectros- copy before and after DBD exposure. Results from surface analysis revealed that reactive oxygen species from the DBD discharge contributed to alterations on the chemistry of the cell membrane/ cell wall of S. epidermidis

Inundation mapping – a study based on December 2004 Tsunami Hazard along Chennai coast, Southeast India

Tsunami impact study has been undertaken along Chennai coast starting from Pulicat to Kovalam. The study area Chennai coast is mainly devoted to prepare large scale action plan maps on tsunami inundation incorporating land use details derived from satellite data along with cadastral data using a GIS tool. Under tsunami inundation mapping along Chennai coast an integrated approach was adopted to prepare thematic maps on land use/land cover and coastal geomorphology using multispectral remote sensing data. The RTK dGPS instruments are used to collect elevation contour data at 0.5 m intervals for the Chennai coast. The GIS tool has been used to incorporate the elevation data, tsunami inundation markings obtained immediately after tsunami and thematic maps derived from remote sensing data. The outcome of this study provides an important clue on variations in tsunami inundation along Chennai coast, which is mainly controlled by local geomorphologic set-up, coastal zone elevation including coastal erosion protection measures and near shore bathymetry. This study highlights the information regarding most vulnerable areas of tsunami and also provides indication to demarcate suitable sites for rehabilitation