7,569 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
An Explication of Pandemic Public Health Emergency, Coronavirus Disease 2019 (COVID-19): A Review
In December 2019 a series of acute atypical respiratory disease occurred in Wuhan, China. The first clusters of cases were identified in association with the South China Seafood Market. In subsequent investigations it was found to be a novel coronavirus. It is suggested to have zoonotic origin. On December 31st 2019, China notified the outbreak to the World Health Organization. During the New Year, the massive migration of Chinese fuelled the epidemic. Cases in other provinces of China and other countries (South Korea, Thailand and Japan in quick succession) were reported in people who were returning from Wuhan. On 11 February, on the basis of existing rules on taxonomy the virus was names as SARS-CoV-2. SARS-CoV-2 belongs to the family of coronaviruses. It is a positive-sense single-stranded RNA (+ssRNA) virus. It has a single linear RNA segment. On the same day WHO announced the new name for the disease i.e. Coronavirus disease 2019 (COVID-19). The WHO and the US Centers for Disease Control and Prevention (CDC) say it is primarily spread directly due to close contact between people through small droplets produced during coughing, sneezing or talking within a range of about 1-3 meters. It may even transmit through indirect contact via fomites. While there are concerns it may spread by feces, this risk is believed to be low. Soon, the number of cases started increasing exponentially and on March 12, 2020 WHO announced COVID-19 a pandemic. COVID-19 has been impacting a large number of people worldwide, being reported in approximately 200 countries and territories. It was identified that Angiotensin converting enzyme 2 (ACE2) act as a functional receptor for SARS-CoV-2. The pathophysiology of COVID-19 follows sex differences, age differences, race differences in as well as underlying disease conditions i.e. comorbidities aggravated the severity of this disease. The most common symptoms being reported are fever, dry cough or chest tightness, and dyspnoea. It is now widely recognized that respiratory symptoms of COVID-19 are extremely heterogeneous, ranging from minimal symptoms to significant hypoxia with ARDS. Diagnosis is done with the help of history, clinical signs and serological testing. Real-time reverse transcription polymerase chain reaction (rRT-PCR) is considered the standard method of testing. Several have been tested in clinical trials but none of them have been proven to be a definite therapy yet. The evolution of the current outbreak has seen extraordinary measures put in place to control transmission, including the âshut-downâ and âquarantineâ. Researchers are trying to develop a vaccine against SARS-CoV-2 but at present, no vaccine is available. One should strictly follow all the preventive measures as directed by WHO and CDC and along with this, one should boost up its natural immunity to lessen the chances of getting infection
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