372 research outputs found

    Evaluating the oral health-related quality of life among dental patients in South India - A Descriptive Study

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    This study aims to evaluate the oral health-related quality of life among dental patients in South India

    Superconducting Material Diagnostics using a Scanning Near-Field Microwave Microscope

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    We have developed scanning near-field microwave microscopes which can image electrodynamic properties of superconducting materials on length scales down to about 2 μ\mum. The microscopes are capable of quantitative imaging of sheet resistance of thin films, and surface topography. We demonstrate the utility of the microscopes through images of the sheet resistance of a YBa2Cu3O7-d thin film wafer, images of bulk Nb surfaces, and spatially resolved measurements of Tc of a YBa2Cu3O7-d thin film. We also discuss some of the limitations of the microscope and conclude with a summary of its present capabilities.Comment: 6 pages with 9 figures, Proceedings of the Applied Superconductivity Conference 199

    Rigid rod spaced fullerene as building block for nanocluster

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    By using phenylacetylene based rigid-rod linkers (PhA), we have successfully synthesized two fullerene derivatives, C60-PhA and C60-PhA-C60.The absorption spectral features of C60, as well as that of the phenylacetylene moiety are retained in the monomeric forms of these fullerene derivatives, ruling out the possibility of any strong interaction between the two chromophores in the ground state. Both the fullerene derivatives form optically transparent clusters, absorbing in the UV-Vis region; this clustering leads to a significant increase in their molar extinction coefficients. TEM characterization of the C60-PhA showed large spherical clusters, with sizes ranging from 150-350 nm, while an elongated wire-type structure was observed for the bisfullerene derivative (C60-PhA-C60).AFM section analysis studies of isolated nanoclusters of C60-PhA-C60, deposited on mica, indicate that smaller clusters associate to form larger nanostructures

    Laser-triggered ion acceleration and table top isotope production

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    We have observed deuterons accelerated to energies of about 2 MeV in the interaction of relativistically intense 10 TW, 400 fs laser pulse with a thin layer of deuterated polystyrene deposited on Mylar film. These high-energy deuterons were directed to the boron sample, where they produced ~105 atoms of positron active isotope 11C from the reaction 10B(d,n)11C. The activation results suggest that deuterons were accelerated from the front surface of the target

    Testing a new analytic model for gravitational lensing probabilities

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    We study gravitational lensing with a multiple lens plane approach, proposing a simple analytical model for the probability distribution function (PDF) of the dark matter convergence, kappa, for the different lens planes in a given cosmology as a function of redshift and smoothing angle, theta. The model is fixed solely by the variance of kappa, which in turn is fixed by the amplitude of the power spectrum, sigma_8. We test the PDF against a high resolution Tree-Particle-Mesh simulation and find that it is far superior to the Gaussian or the lognormal, especially for small values of theta << 1 arcmin and at large values of kappa relevant to strong lensing. With this model, we predict the probabilities of strong lensing by a single plane or by multiple planes. We find that for theta ~ 10 arcsec, a single plane accounts for almost all (~ 98%) of the strong lensing cases for source redshift unity. However, for a more typical source redshift of 4, about 12% of the strong lensing cases will result from the contribution of a secondary clump of matter along the line of sight, introducing a systematic error in the determination of the surface density of clusters, typically overestimating it by about 2-5%. We also find that matter inhomogenieties introduce a dispersion in the value of the angular diameter distance about its cosmological mean. The probable error relative to the mean increases with redshift to a value of about 8% for z ~ 6 and theta ~ 10 arcsec.Comment: Accepted for publication in ApJ, 13 pages, 12 figures, revised version, references added, section 6 expande

    Web based software for the study of USDA soil taxonomy and classification of newly found soil

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    United States Department of Agriculture (USDA) Soil Taxonomy is based on soil properties that can be objectively observed and measured in the natural conditions as they exist today. There are many soil classification systems but USDA Soil Taxonomy is most accepted worldwide. Ontologies are the new form of knowledge representation that acts in synergy with agents and Semantic Web Architecture. Soil ontology developed for USDA soil taxonomy has been used to develop a query interface that will help in detailed study of soil taxonomy, classification of new soil as well as exchange knowledge between software agents and systems. This is a web based application having N-tier architecture. Application development environment is NetBeans 6.9 editor and Protégé. Web development technology is Java Server Pages (JSP). Programming languages JAVA and SPARQL are used for querying. Client interface is developed with Hyper Text Markup Language (HTML), Cascading Style Sheet (CSS) and JavaScript. Third tier of software consist of database which is in MS-SQL server 2005. Other two layers are Web Ontology Language (OWL) Ontology layer and Semantic Web Framework layer. OWL layer contains soil taxonomy information in the form of Ontology. Semantic Web Framework layer is implemented using JENA. In the search panel user can search anything related to USDA Soil Taxonomy, which comprises of twelve orders. However, this software contains information about seven soil orders reported in India. Domain experts can see and edit the knowledge base (i.e. Soil Ontology) or can suggest anything related to the creation of Soil Taxonomy Ontology through WebProtégé

    Study of Energetic Ion Generation from High-Intensity-Laser Dense-Plasma Interactions

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    We report on the characteristics of an ultrafast-laser driven proton beam from thinfilm targets. The difference in proton beam profiles, beam energies, and laser induced back ablation plumes between a dielectric (Mylar) and a conductor (aluminum) are discussed. Evidence for front-side acceleration and a method for beam manipulation are also presented

    Trapped fermions in a synthetic non-Abelian gauge field

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    On increasing the coupling strength (λ\lambda) of a non-Abelian gauge field that induces a generalized Rashba spin-orbit interaction, the topology of the Fermi surface of a homogeneous gas of noninteracting fermions of density \rho \sim \kf^3 undergoes a change at a critical value, \lambda_T \approx \kf [Phys. Rev. B {\bf 84}, 014512 (2011)]. In this paper we analyze how this phenomenon affects the size and shape of a cloud of spin-\half fermions trapped in a harmonic potential such as those used in cold atom experiments. We develop an adiabatic formulation, including the concomitant Pancharatnam-Berry phase effects, for the one particle states in the presence of a trapping potential and the gauge field, obtaining approximate analytical formulae for the energy levels for some high symmetry gauge field configurations of interest. An analysis based on the local density approximation reveals that, for a given number of particles, the cloud shrinks in a {\em characteristic fashion with increasing λ\lambda}. For an isotropic harmonic trap, the local density approximation predicts a spherical cloud for all gauge field configurations, which are anisotropic in general. We show, via a calculation of the cloud shape using exact eigenstates, that for certain gauge field configurations there is systematic and observable anisotropy in the cloud shape that increases with increasing gauge coupling λ\lambda. These results should be useful in the design of cold atom experiments with fermions in non-Abelian gauge fields. An important spin-off of our adiabatic formulation is that it reveals exciting possibilities for the cold-atom realization of interesting condensed matter Hamiltonians (eg. quantum hall spherical geometry) by using a non-Abelian gauge field in conjunction with another potential.Comment: 10 Pages, 4 figure

    Biotransformation of artemisinin mediated through fungal strains for obtaining derivatives with novel activities

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    Artemisinin, a sesquiterpene lactone, is the active antimalarial constituent of Artemisia annua. Several fungal strains Saccharomyces cerevisiae, Aspergillus flavus, Aspergillus niger and Picchia pastoris were used to biotransform artemisinin. Among these strains, A. flavus was the only microorganism capable of transforming artemisinin to deoxyartemisinin in higher yields than the previous reports. The structure of deoxyartemisinin was elucidated by spectroscopy. Deoxyartemisinin showed antibacterial activity against Staphylococcus aureus, S. epidermidis and S. mutans at a minimum inhibitory concentration (MIC) of 1 mg/mL compared to artemisinin whose MIC was &#x3e;2 mg/mL
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