817 research outputs found

    Predicting solar cycle 24 with a solar dynamo model

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    Whether the upcoming cycle 24 of solar activity will be strong or not is being hotly debated. The solar cycle is produced by a complex dynamo mechanism. We model the last few solar cycles by `feeding' observational data of the Sun's polar magnetic field into our solar dynamo model. Our results fit the observed sunspot numbers of cycles 21-23 extremely well and predict that cycle~24 will be about 35% weaker than cycle~23.Comment: 10 pages 1 table 3 figure

    Study of implosion in an attractive Bose-Einstein condensate

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    By solving the Gross-Pitaevskii equation analytically and numerically, we reexamine the implosion phenomena that occur beyond the critical value of the number of atoms of an attractive Bose-Einstein condensate (BEC) with cigar-shape trapping geometry. We theoretically calculate the critical number of atoms in the condensate by using Ritz's variational optimization technique and investigate the stability and collapse dynamics of the attractive BEC by numerically solving the time dependent Gross-Pitavskii equation

    Possible Use of Light Alloys on Indian Railways

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    THE resources of the raw materials from which aluminium and magnesium are produced, are so abundant and widespread in India that one can hardly visualise conditions in which the users will at any time have difficulty in obtaining their full requirements, if these are fully exploited. This free availability in a world of shortages has, in itself, led numbers of manufacturers to abandon traditional materials like steel, copper, lead, zinc, etc. in favour of light alloys ; and many who were thus first attracted will never wish to forego the advantages they have found in their use. Nevertheless Our main interest should be to further the development of light alloys in their natural and proper field--the field in which these materials stand supreme by reason of their unique characteristics and availability in India

    Indigenous substitution of import ed materials on Indian Railways

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    THE psychology of import substitution is based on the concept of dispensing with as much import as poss- ible by providing alternative indigenous resources. In a developing country like India, it is essential to stress on research , development and trials through different research laboratories/Institutes by suggesting substitutes of imported materials for the avoidance of use or conservation of the imported materials in our country, particularly in the emergency which has high-lighted the necessity for intensifying efforts in this direction

    Hall Mobility of Tellurium Films Deposited on BaTiO3 Crystal

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    The measurements of electrical resistivity and Hall coefficient of tellurium films deposited on polarised barium titanate single crystals have been reported; the results on glass and mica substrate are also included for comparison. The results yield a value of surface state density for tellurium to be 15 X 1O 14/cm2 volt and the energy of the surface states 0.09 e.v. below the mid gap position
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