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On the relationship between the magnetic field variations and meteor showers

2003-12-01T00:00:00Z

Title: On the relationship between the magnetic field variations and meteor showers Authors: Kulkarni, V H; Kane, R P Abstract: The magnetic Z field variation for the period 9-25 Dec. 1996, recorded at the stations Sodankyla (67.37°N, 26.63°E), Tromso (69.67°N, 18.95°E), Abisko (68.30°N, 18.82°E), and Hornsund (77.00°N, 26.63°E) (http://swdcwww.kugi.kyoto-u.ac.jp) are compared with the Geminids (12-15 Dec. 1996) and Ursids (20-23 Dec. 1996) showers as reported by Yrjola (http://www.rmob.org). The correlation studies show that it is difficult to prove conclusively that the magnetic field fluctuations observed at Sodankyla are due to the dust particles in the meteor showers and the associated changes in the ionospheric currents due to them. Page(s): 385-386

Beam shaping of V-slot waveguide antenna using corner reflector

2003-12-01T00:00:00Z

Title: Beam shaping of V-slot waveguide antenna using corner reflector Authors: Makal, B S; Vani, RM; Hadalgi, P M; Mulgi, S N; Hunagund, P V Abstract: This paper presents the experimental investigations of the variation of on-axis power, half-power beam width and VSWR of V-slot waveguide antenna (V-SWGA) for different parameters of corner reflector (CR). Experimental study reveals that the CR has very predominant effect in improving the antenna parameters of V-SWGA. Page(s): 382-384

Equivalence between external electric field with temperature and supersaturation in nucleation process

2003-12-01T00:00:00Z

Title: Equivalence between external electric field with temperature and supersaturation in nucleation process Authors: Singh, N; Kumar, Anand Abstract: The equivalence between critical temperature corresponding to unit nucleation rate per unit volume has been studied with external electric field applied to water vapours. It has been found that an external electric field of 1 e.s.u. with different supersaturation ratio is equivalent to several orders of temperature. The high electric field is found to correspond with lower temperatures for critical nucleation. The theory of droplet growth in presence of external electric field has been applied to water vapour condensation. The radius of critical nucleus is found to depend on electric field and relaxation time. Further in presence of electric field, Gibb's free energy of formation of water molecule changes for a critical nucleus and is found to be much less than that in absence of the electric field, but equilibrium concentration of nuclei is very much larger. Page(s): 379-381

Mixed layer height over Bay of Bengal during Indian summer monsoon using MONTBLEX observations

2003-12-01T00:00:00Z

Title: Mixed layer height over Bay of Bengal during Indian summer monsoon using MONTBLEX observations Authors: Patil, M N; Parasnis, S S Abstract: The height of mixed layer and cloud base is studied in relation to surface meteorological parameters, surface fluxes of heat and momentum and synoptic weather disturbances. For this study, surface as well as upper air meteorological observations collected over north Bay of Bengal (20°N, 89°E) during the summer monsoon of 1990 as a part of Monsoon Trough Boundary Layer Experiment (MONTBLEX), were utilized. Empirical relation between the cloud base height and the surface meteorological observations has been verified for its validity over Bay of Bengal. This height is further compared with aerological observations. A simple relation based on surface air temperature, pressure and wind speed has been suggested to estimate the cloud base height. Influence of the turbulent surface fluxes of heat and momentum on evolution of mixed layer over Bay of Bengal has been brought out. Page(s): 373-378