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Multiflash whistlers in ELF-band observed at low latitude
Multiflash whistler-like event in the ELF-band, observed during
March 1998 at low latitude station Jammu, is reported. The most
prominent feature of these events is the multiflash nature along
with the decrease in frequency within a very short span of time
resembling similar to terrestrial whistlers. The events have a
significantly smaller time duration (0.5–3.5 s) than those
reported earlier from high, mid and low latitudes and also display a
diurnal maximum occurring around 09:30 h (IST). There have been
similar reportings from other latitudes, but whistlers in the
ELF-band with a multiflash nature along with a precursor emission
have never been reported. Lightning seems to be the dominant source
for the ELF whistlers reported here
Nuclear Effects in Neutrino Induced Coherent Pion Production at K2K and MiniBooNE Neutrino Energies
The coherent pion production induced by neutrinos in nuclei is studied using
a delta hole model in local density approximation taking into account the
renormalization of properties in a nuclear medium. The pion absorption
effects have been included in an eikonal approximation. These effects give a
large reduction in the total cross section. The numerical results for the total
cross section are found to be consistent with recent experimental results from
K2K and MiniBooNE collaborations and other older experiments in the
intermediate energy region.Comment: 4pages, 5figure
Heat capacity and magnetoresistance in Dy(Co,Si)2 compounds
Magnetocaloric effect and magnetoresistance have been studied in
Dy(Co1-xSix)2 [x=0, 0.075 and 0.15] compounds. Magnetocaloric effect has been
calculated in terms of adiabatic temperatue change (Delta Tad) as well as
isothermal magnetic entropy change (Delta SM) using the heat capacity data. The
maximum values of DeltaSM and DeltaTad for DyCo2 are found to be 11.4 JKg-1K-1
and 5.4 K, respectively. Both DSM and DTad decrease with Si concentration,
reaching a value of 5.4 JKg-1K-1 and 3 K, respectively for x=0.15. The maximum
magnetoresistance is found to about 32% in DyCo2, which decreases with increase
in Si. These variations are explained on the basis of itinerant electron
metamagnetism occurring in these compounds.Comment: Total 8 pages of text and figure
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