Source Regions of Coronal Mass Ejections

Observations of the solar corona with the Large Angle Spectrometric Coronograph (LASCO) and Extreme ultraviolet Imaging Telescope (EIT) instruments on the Solar and Heliospheric Observatory (SOHO) provide an unprecedented opportunity to study coronal mass ejections (CMEs) from their initiation through their evolution out to 30 \rsun. The objective of this study is to gain an understanding of the source regions from which the CMEs emanate. To this end, we have developed a list of 32 CMEs whose source regions are located on the solar disk and are well observed in EIT 195 {\AA} data during the period from so lar minimum in January 1996 through the rising part of the cycle in May 1998. We compare the EIT source regions with photospheric magnetograms from the Michelson Doppler Imager (MDI) instrument on SOHO and the NSO/Kitt Peak Observatory and also with H$\alpha$ data from various sources. The overall results of our study show that 41% of the CME related transients observed are associated with active regions and have no prominence eruptions, 44% are associated with eruptions of prominences embedded in active regions and 15% are associated with eruptions of prominences outside active regions. Those CMEs that do not involve prominence eruptions originate in active regions both with and without prominences. We describe 6 especially well observed events. These case studies suggest that active region CMEs (without eruptive prominences) are associated with active regions with lifetimes between 11--80 days. They are also often associated with small scale emerging or cancelling flux over timescales of 6--7 hours. CMEs associated with active region prominence eruptions, on the other hand, are typically associated with old active regions with lifetimes $\sim$ 6-7 months.Comment: Accepted for publication in ApJ, scheduled for Nov 1, 2001 issu

Reliabilty and Cost Benefit Analysis of DG Integrated Distribution System

Integration of Distributed generation (DG) results in a number of advantages ranging from reduction in losses to delayed generation and transmission capacities. In this paper the impact of DGs on reliability is considered and their effect on reliability in terms of number and location is evaluated. The integration of DG changes configuration of the radial system. This point is considered for evaluating the load point indices. The cost effectiveness of number of DGs is evaluated for the determining the returns on the DG investment cost. The above analysis is carried out on a RBTS Bus 2 system. The reliability indices are calculated using FMEA technique

A Monopole-Antimonopole Solution of the SU(2) Yang-Mills-Higgs Model

As shown by Taubes, in the Bogomol'nyi-Prasad-Sommerfield limit the SU(2) Yang-Mills-Higgs model possesses smooth finite energy solutions, which do not satisfy the first order Bogomol'nyi equations. We construct numerically such a non-Bogomol'nyi solution, corresponding to a monopole-antimonopole pair, and extend the construction to finite Higgs potential.Comment: 11 pages, including 4 eps figures, LaTex format using RevTe

The mini trawl fishery of Kerala

Mini trawl operation started in Kerala during 1987, is another post motorisation innovation like the ring seine by the artisanal fishers. During 1987-2002, annual mini trawl landings ranged between 1,500 and 18,600 tonnes. The minimum landing was in 1987, when this gear was introduced for the first time in Kerala and the peak landings of 18,600 tonnes was during 1997. The low investment of the mini trawls at the initial stage has attracted more fishermen. A trend in component group landings and seasonal trends have been cited in this information. They could earn more for their livelihood with less investment. Prawns which come to the nearby shore for breeding, are caught by this gear. Appropriate management measures need to be taken to regulate this fishery for ensuring sustrainbility and better livelihood for the artisanal sector