5,930 research outputs found
Smart Bike Sharing System to make the City even Smarter
These last years with the growing population in the smart city demands an
efficient transportation sharing (bike sharing) system for developing the smart
city. The Bike sharing as we know is affordable, easily accessible and reliable
mode of transportation. But an efficient bike sharing capable of not only
sharing bike also provides information regarding the availability of bike per
station, route business, time/day-wise bike schedule. The embedded sensors are
able to opportunistically communicate through wireless communication with
stations when available, providing real-time data about tours/minutes, speed,
effort, rhythm, etc. We have been based on our study analysis data to predict
regarding the bike's available at stations, bike schedule, a location of the
nearest hub where a bike is available etc., reduce the user time and effort
AC susceptibility study of superconducting YBa2Cu3O7:Agx bulk composites (x = 0.0-0.20): The role of intra and inter granular coupling
We report the effect of silver addition on superconducting performance of
bulk YBCO (YBa2Cu3O7) superconductor. All the studied samples are prepared by
conventional solid-state reaction method. Rietveld fitted X-ray diffraction
data confirmed the single phase formation for all the studied samples. Detailed
AC susceptibility measurements as a function of driven AC amplitude (1Oe-17Oe)
of these samples revealed the enhancement of grains coupling with increasing Ag
content in YBCO+Agx composite system. 10wt% Ag added YBCO superconductors
exhibited the optimum inter granular coupling. The Scanning Electron Microscopy
(SEM) observations indicate an increase in the grains connectivity in terms of
narrow grain boundaries for doped samples. The average grain size is found to
increase with Ag doping. It is concluded that limited addition of Ag in bulk
YBCO superconductor significantly improves the grains coupling and as result
optimum superconducting performance. YBCO+Ag composites could prove to be
potential candidates for bulk superconducting applications of the studied high
Tc system.Comment: 15 pages of text + Fig
High-resolution polarization imaging of the Fermi blazar 3C 279
Ever since the discovery by the Fermi mission that active galactic nuclei (AGN) produce copious
amounts of high-energy emission, its origin has remained elusive. Using high-frequency radio
interferometry (VLBI) polarization imaging, we could probe the magnetic field topology of the
compact high-energy emission regions in blazars. A case study for the blazar 3C 279 reveals
the presence of multiple g -ray emission regions. Pass 8 Fermi-Large Area Telescope (LAT) data
are used to investigate the flux variations in the GeV regime; six g -ray flares were observed in
the source during November 2013 to August 2014. We use the 43 GHz VLBI data to study
the morphological changes in the jet. Ejection of a new component (NC2) during the first three
g -ray flares suggests the VLBI core as the possible site of the high-energy emission. A delay
between the last three flares and the ejection of a new component (NC3) indicates that highenergy
emission in this case is located upstream of the 43 GHz core (closer to the black hole).Accepted manuscrip
Evolution of superconductivity in PrFe1-xCoxAsO with x = 0.0 to 1.0
We report the synthesis and physical property characterization of
PrFe1-xCoxAsO with x = 0.0 to 1.0. The studied samples are synthesized by solid
state reaction route via vacuum encapsulation method. The pristine compound
PrFeAsO does not show superconductivity, but rather exhibits a metallic step
like transition due to spin density wave ordering of Fe moments below 150 K,
followed by another upward step due to anomalous ordering of Pr moments at 12
K. Both the Fe-SDW and Pr-TN temperatures decrease monotonically with Co
substitution at Fe site. Superconductivity appears in a narrow range of x from
0.07 to 0.25 with maximum Tc at 11.12 K for x = 0.15. Samples, with x = 0.25
exhibit metallic behavior right from 300 K down to 2 K, without any Fe-SDW or
Pr-TN steps in resistivity. In fact, though Fe-SDW decreases monotonically, the
Pr-TN is disappeared even with x = 0.02. The magneto transport measurements
below 14 Tesla on superconducting polycrystalline Co doped PrFeAsO lead to
extrapolated values of the upper critical fields [Hc2(0)] of up to 60 Tesla.Comment: 15 pages Text+Fig
Child Labor Among the Tribal's: a Study in Kurnool District of Andhra Pradesh
Children are the most precious human resource and hold the potential for future development of the nation. If children are deprived of their childhood, the social progress and economic development of the country would be adversely affected. Child labor is a global issue which is more common in the underdeveloped countries. Poor parents or parents under the poverty line are unable to afford the education expenses of their kids and they own unable to earn enough money for the family survival. Children are the new flowers with a powerful fragrance of any nation, however, some people are declining the power and destroying the future of the country just for earning small money by illegally involving the growing kids. They are playing with the moral of the innocent people and their kids
Current understanding and Future Approaches for Controlling Microbially Influenced Concrete Corrosion: A Review
The microbes colonize the concrete surface and its pores, capillaries and micro-cracks and cause damage through biodeterioration. Though the biodeterioration of concrete in sewage pipes is extensively studied, the problems in constructions such as maritime structures, bridges, tanks, pipelines and cooling towers have received lesser attention. In nuclear industry future power plants will be designed for 100 years to make available operation of nuclear power plants for more periods. Therefore, integrity of the concrete structures in nuclear power plants has to be maintained for this long duration specially those exposed to aggressive seawater environment. Nuclear industry is looking at various options including modified concrete with special admixtures and fly ash to achieve this goal. A direction for future approaches like using nanophase modification to get stronger and flexible concrete is given in this paper
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