7,301 research outputs found
A novel approach to reconstructing signals of isotropy violation from a masked CMB sky
Statistical isotropy (SI) is one of the fundamental assumptions made in
cosmological model building. This assumption is now being rigorously tested
using the almost full sky measurements of the CMB anisotropies. A major hurdle
in any such analysis is to handle the large biases induced due to the process
of masking. We have developed a new method of analysis, using the bipolar
spherical harmonic basis functions, in which we semi-analytically evaluate the
modifications to SI violation induced by the mask. The method developed here is
generic and can be potentially used to search for any arbitrary form of SI
violation. We specifically demonstrate the working of this method by recovering
the Doppler boost signal from a set of simulated, masked CMB skies.Comment: 8 pages, 3 figure
Transport and energy in India. Energy used by Indian transport systems and consequent emissions: the need for quantitative analyses (Well-to-Wheel, Lifecycle)
The purpose of this work is, at first, a general overview on the state-of-art of the transportation system in India outlining the related energy consumption, for the different transport modes, with consequent estimated emissions. These elements are essential for the preparation of a high-level strategic transport planning on the whole energy issue, to help India in the choices of most suitable transportation systems, according to the well-to-wheel analysis (WTW). Pursuing a WTW global index for India that takes into account both the energy and environmental aspects on a uniform basis is an important aim: it allows the best choices to be made as well as enabling the comparison between some of the most important powertrain and fuel options on the Indian market, the results are discussed from three different points of view: energy, environmental and economic impac
Radio-Frequency Impedance Measurements on Thin Films of Yttrium Barium Copper Oxide.
The Kosterlitz-Thouless phase transition in epitaxial films of YBCO of varying thickness is studied. The phase transition is found to occur in these films in both zero fields and in perpendicular and parallel magnetic fields up to 0.5 T. In addition, the same transition is seen in a lead film of thickness less than the penetration depth in lead. This measurement is used as a calibration to determine the penetration depth in YBCO for both the zero-field case and perpendicular-field case. Once the penetration depth is determined, the effective thickness of the superconducting layer is calculated for all the films. The effective thickness is determined to be approximately 181 A in zero external field and 177 A in perpendicular fields, independent of film thickness
Aerosol Characteristics at a high-altitude station Nainital during the ISRO-GBP Land Campaign-II
During the second land campaign (LC-II) organised by ISRO-GBP, extensive
ground-based measurements of aerosol characteristics were carried out over
Manora Peak (29.4oN; 79.5oE; 1951 metres above mean sea level), Nainital (a
high altitude station located in the Shivalik ranges of Central Himalayas)
during the dry, winter season (December) of 2004. These measurements included
the spectral aerosol optical depths (AOD), columnar water vapour content (W),
Total Columnar Ozone (TCO), total number concentration (NT) of near surface
aerosols, mass concentration of black carbon (MB), aerosol mass loading (MT),
and Global Solar Radiation. Based on these measured parameters, we present the
results on the near-surface and columnar properties of atmospheric aerosols at
Nainital.Comment: Published in the Proceedings of the ISRO-GBP Land-Campaign-II
meeting, Physical Research Laboratory, Ahmadabad (Inida), March 200
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