Holographic chiral induced W-gravities

We study boundary conditions for 3-dimensional higher spin gravity that admit asymptotic symmetry algebras expected of 2-dimensional induced higher spin theories in the light cone gauge. For the higher spin theory based on sl(3, R) plus sl(3,R) algebra, our boundary conditions give rise to one copy of classical W3 and a copy of sl(3,R) or su(1,2) Kac-Moody symmetry algebra. We propose that the higher spin theories with these boundary conditions describe appropriate chiral induced W-gravity theories on the boundary. We also consider boundary conditions of spin-3 higher spin gravity that admit u(1) plus u(1) current algebra.Comment: 19 page

On Asymptotic Symmetries of 3d Extended Supergravities

We study asymptotic symmetry algebras for classes of three dimensional supergravities with and without cosmological constant. In the first part we generalise some of the non-Dirichlet boundary conditions of $AdS_3$ gravity to extended supergravity theories, and compute their asymptotic symmetries. In particular, we show that the boundary conditions proposed to holographically describe the chiral induced gravity and Liouville gravity do admit extension to the supergravity contexts with appropriate superalgebras as their asymptotic symmetry algebras. In the second part we consider generalisation of the 3d $BMS$ computation to extended supergravities without cosmological constant, and show that their asymptotic symmetry algebras provide examples of nonlinear extended superalgebras containing the $BMS_3$ algebra

An sl(2, R) current algebra from AdS_3 gravity

We provide a set of chiral boundary conditions for three-dimensional gravity that allow for asymptotic symmetries identical to those of two-dimensional induced gravity in light-cone gauge considered by Polyakov. These are the most general boundary conditions consistent with the boundary terms introduced by Compere, Song and Strominger recently. We show that the asymptotic symmetry algebra of our boundary conditions is an sl(2,R) current algebra with level given by c/6. The fully non-linear solution in Fefferman--Graham coordinates is also provided along with its charges.Comment: 8 page

A Study of Phytochemical Composition of a Few Tribal Medicinal Plants from Sriharikota

SRIHARIKOTA acquired importance botanically because of rich Island vegetation and due to installation of Rocket Launching Station by Indian Space Research Organisation (ISRO). A few Tribal colonies are domiciled there. Some aged tribal men conversed with herbal medicines and practices. With a fear that this tribal medicinal knowledge of the island may be lost, if urgently not pursued in a recorded manner for the benefit of modern society, a project on Ethnobotany and tribal medicines of Sriharikota Island is taken up three years back in 1996. Regular field tours are conducted covering all the seasons and about 300 medicinal plants are collected along with ample field notes on folklore medicinal uses with the support of local aged tribal men. Out of these, a few plants are selected on the basis of endemism and utility and subjected to phytochemical analysis. Investigation for 11 chemical components is made in 21 samples. All the data is recorded in this paper. The results are mostly in conformity with the medicinal uses and they are discussed

Antimicrobial Screening of Some Selected Tribal Medicinal Plants from Sriharikota Island, Andhra Pradesh, India

Sriharikota Island is important because of its rich vegetational diversity and for the fact that it is the site of a Rocket Launching Station built by the Indian Space Research Organization (ISRO). An aboriginal tribe called ‘Yanadi’ dwells in a few tribal pockets on Sriharikota Island. However, a few aged tribal men are still able to furnish information regarding their traditional practices of medicines and recipes. There is an urgent need to conserve their herbal wealth and preserve their traditional knowledge for the benefit of modern society. It is with this background, along with the need to give a primary scientific basis to the tribal medicinal lore of Sriharikota Island, that a preliminary screening of antimicrobial (antibacterial and antifungal) activity screening was conducted for 81 tribal medicinal samples based on their medicinal importance and endemism/rare occurrence on the island. Of these 81 samples, 28 have shown positive response for antimicrobial tests. Among these 8 species, namely Alangium salvifolium, Aristolochia indica, Ctrullus colocynthis, Datura stramonium, Ficus religiosa, Holoptelia integrifolia, Lawsonia innermis and Ventilago madaraspatana have shown congizable immunity zone of inhibition (i.e. above 20 mm). All the data is recorded in this paper. The results are mostly in conformity of the medicinal uses and they are discussed in detail in this article

Ethnomedicinal Recipes for Respiratory and Bronchial Diseases from Tribals of Sriharikota Island, Andhra Pradesh

Sriharikota Island in Andhra Pradesh is an elliptical land mass sandwiched between Bay of Bengal in the East and Pulicat lake in the West. Sullurpet is the nearest railway station, which is 18 Km from Sriharikota Island and it is on Chennai-Kolkata trunk line and 90 Km away from North of Chennai. An aboriginal tribe called Yanadi dwells in Sriharikota. It is similar to Chenchu community elsewhere in Andhra Pradesh. In spite of the community being drifted from their natural way of life due to agro-rural development activities, a few aged tribals are still able to furnish traditional ethnomedicinal data. So far no ethno medico-botanical studies are conducted in this area except for list of 50 plants reported for general ailments/ diseases by Suryanarayana et al. (1989). Therefore a detailed study on ethno medico-botanical uses of the tribals of Sriharikota Island was undertaken for the duration three years (1996-1999). During this work about 280 species are collected having a variety of ethno medico-botanical/pharmaceutical values. However the article presents the 20 plant species only having remedial effect for respiratory and bronchial diseases. The study analyzes the habit and plant part(s) used for ethnomedicinal practices by the tribals of Sriharikota Island

Total cross sections for neutron-nucleus scattering

Systematics of neutron scattering cross sections on various materials for neutron energies up to several hundred MeV are important for ADSS applications. Ramsauer model is well known and widely applied to understand systematics of neutron nucleus total cross sections. In this work, we examined the role of nuclear effective radius parameter (r$_0$) on Ramsauer model fits of neutron total cross sections. We performed Ramsauer model global analysis of the experimental neutron total cross sections reported by W. P. Abfalterer, F. B. Bateman, {\it et. al.,}, from 20MeV to 550MeV for nuclei ranging from Be to U . The global fit functions which can fit total cross section data over periodic table are provided along with the required global set of parameters. The global fits predict within $\pm 8$ deviation to data, showing the scope for improvement. It has been observed that a finer adjustment of r$_0$ parameter alone can give very good Ramsauer model description of neutron total scattering data within $\pm 4$ deviation. The required r$_0$ values for Ramsauer model fits are shown as a function of nuclear mass number and an empirical formula is suggested for r$_0$ values as a function of mass number. In optical model approach for neutron scattering, we have modified the real part of Koning-Deleroche potentails to fit the neutron total cross sections using SCAT2 code. The modified potentails have a different energy dependence beyond 200MeV of neutron energy and fit the total cross sections from Al to Pb.Comment: 9 pages, 20figures, Poster number ND-1457, ND2010 Conference in Kore

Effect of Ultrasonic Vibrations in Some Heat Treatments

The effect of ultrasonic vibrations on many heat treatment processes, primarily ageing, and other such as, hardening of solid and porous compacts, spheroidisation, etc. are described. Results obtained with regard to ageing are particularly promising and indicate the possibility of obtaining a distinctly shorter process time as also an increased ductility at the same strength. These features may be of interest to the aircraft industry

Mechanically induced fcc phase formation in nanocrystalline hafnium

A face-centered-cubic (fcc) phase was obtained in high-purity hafnium (Hf) metal powders subjected to mechanical milling in a high-energy SPEX shaker mill. X-ray diffraction and electron microscopy techniques were employed to evaluate the structural changes in the milled powder as a function of milling time. The effects of mechanical milling included a reduction in grain size, an increase in lattice strain, and formation of an fcc phase instead of an equilibrium hexagonal-close-packed (hcp) phase. During milling, the grain size of Hf decreased to below about 7 nm. Additionally, there was approximately 6% increase in atomic volume during the formation of the fcc phase. Chemical analysis of the milled powder indicated the presence of significant amounts of interstitial impurities. Even though any or all of the above factors could contribute to the formation of the fcc phase in the milled powder, it appears that the high level of interstitial impurities is at least partially responsible for the formation of the fcc phase