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151.
152.
153.
We studied the cosmic ray intensity variation due to interplanetary magnetic clouds during an unusual class of low amplitude
anisotropic wave train events. The low amplitude anisotropic wave train events in cosmic ray intensity have been identified
using the data of ground based Deep River neutron monitor and studied during the period 1981–1994. Even though the occurrence
of low amplitude anisotropic wave trains does not depend on the onset of interplanetary magnetic clouds, but the possibility
of occurrence of these events cannot be overlooked during the periods of the interplanetary magnetic cloud events. It is observed
that the solar wind velocity remains higher (> 300) than normal and the interplanetary magnetic field B remains lower than normal on the onset of the interplanetary magnetic cloud during the passage of low amplitude wave trains.
It is also noted that the proton density remains significantly low during high solar wind velocity, which is expected. The
north south component of interplanetary magnetic field Bz turns southward to one day before the arrival of cloud and remains in the southward direction after the arrival of a cloud.
During these events the cosmic ray intensity is found to increase with increase of solar wind velocity. The superposed epoch
analysis of cosmic ray intensity for these events during the onset of interplanetary magnetic clouds reveals that the decrease
in cosmic ray intensity starts not at the onset of the cloud but after a few days. The cosmic ray intensity increases on arrival
of the magnetic cloud and decreases gradually after the passage of the magnetic cloud. 相似文献
154.
155.
The thermosolutal instability of a partially-ionized plasma in the presence of a horizontal magnetic field is considered to include the frictional effect of collisions of ionized with neutrals. The sufficient conditions for non-existence of overstability are derived. The solute gradient and magnetic field introduce oscillatory modes in thermosolutal convection which were non-existent in their absence. The magnetic field and stable solute gradient are found to have stabilizing effects whereas collisional effect of ionized with neutrals is found to have destabilizing effect on thermosolutal instability of a partially ionized plasma. 相似文献
156.
157.
Mixed layer depth (MLD) variability in the Eastern Equatorial Indian Ocean (EEIO) from a hindcast run of an Ocean General Circulation Model (OGCM) forced by daily winds and radiative fluxes from NCEP-NCAR reanalysis from 2004 to 2006 is investigated. Model MLD compares well with the ~20,000 observations from Argo floats and a TRITON buoy (1.5°S and 90°E) in the Indian Ocean. Tests with a one-dimensional upper ocean model were conducted to assess the impact on the MLD simulations that would result from the lack of the diurnal cycle in the forcing applied to the OGCM. The error was of the order of ~12 m. MLD at the TRITON buoy location shows a bimodal pattern with deep MLD during May–June and December–January. MLD pattern during fall 2006 was significantly different from the climatology and was rather shallow during December–January both in the model and observation. An examination of mixed layer heat and salt budget suggested salinity freshening caused by the advective and vertical diffusive mixing to be the cause of shallow MLD. 相似文献
158.
ABSTRACTA set of linked optimization models was used to evaluate planning and operation of the proposed Pamba-Achankovil-Vaippar (PAV) water transfer project in India. The shortage of water for irrigation in the Vaippar basin has led to the need for water import. The project consists of three reservoirs. The models were applied at three levels. At Level-1, the projections of water requirement for irrigation in the Vaippar basin at Reservoir-1 were estimated using an LP model. Level-2 was operated at three sub-levels: the first was the determination of the export requirements from the Pamba basin (Reservoir-2) to the Achankovil basin (Reservoir-1); the second was determining the capability of Reservoir-2 to export and sizing of the three reservoirs to meet the above targets was the third sub-level. Integrated reservoir operation and canal irrigation water distribution were done at Level-3. DP models were employed at levels-2 and 3. The linked LP, DP and simulation models were found effective for planning water transfers. 相似文献
159.
In this paper, we have used optical intra-day variability archive data to calculate the central black hole masses and Eddington luminosities for nine blazars: 3C 66A, AO 0235+164, S5 0716+714, PKS 0735+178, OJ 287, 1215+303, 1216−010, 1308+326, PKS 1510−089, Mrk 501 and BL Lac using intra-day variability timescales and periodicity (if present). The calculated central black hole mass of these nine blazars using intra-day variability timescales are found to be in the range of 1.22-25.30 × 107 M⊙ and corresponding Eddington luminosity in the range of 1.58-32.88 × 1045 erg s−1. The black hole mass and Eddington luminosity are in the range of 0.32-31.23 × 108 M⊙ and 1.23-31.20 × 1046 erg s−1, respectively when optical Doppler factor is taken into account. The comparison show, our estimated values of black hole mass are consistent with earlier reported values. Periodicity were present in two blazars OJ 287 and 1216−010 which give the central black hole mass of these blazars in the range of 1.32-14.6 × 107 M⊙ and corresponding Eddington luminosity in the range of 1.60-19.0 × 1045 erg s−1, respectively. 相似文献
160.
The mobility of strontium in subsurface is largely influenced by sorption on to clay minerals. In the present study, kaolinite
clay samples collected from the Kalpakkam nuclear plant site were employed to understand the sorption characteristics of strontium
by batch method. The effect of several parameters such as time, strontium ion concentration, pH, temperature and ionic strength
was investigated. The kinetic studies suggested pseudo-second-order mechanism. The experimental sorption data was fitted to
Langmuir adsorption model for obtaining the sorption capacity of the sorbent. The maximum sorption capacity was 5.77 mg/g
at 298 K and was found to increase with an increase in temperature. It was observed that the distribution coefficient (K
d) of strontium on clay increased as the pH of the solution increased. The distribution coefficient was found to decrease with
an increase in concentration of Na+ and Ca2+ ions. This variation of K
d suggests that cation exchange is the predominant sorption process. It was also observed that sorption process is endothermic.
The thermodynamic parameters such as ∆G
0, ∆H
0 and ∆S
0 were calculated. The negative values obtained for ∆G
0 indicated that the sorption of strontium on clay was spontaneous at all studied concentrations. ∆G
0 becomes more negative with an increase in temperature, suggests that the sorption process is more favorable at higher temperatures. 相似文献