Reply on the comments of M. K. Pandya and S. L. Solanki     

M. Deb  D. M. Banerjee  A. K. Bhattacharya 《Mineralium Deposita》1980,15(3):401-405

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Chemistry of the solar neutrino experiment     

B. Banerjee  S. M. Chitre  P. P. Divakaran  K. S. V. Santhanam 《Astrophysics and Space Science》1977,48(2):445-451

The possibility of chemical ‘trapping’ of the Ar⁺ ion in the reaction $$v{\text{ }} + {\text{ }}^{{\text{37}}} {\text{Cl}} \to {\text{ }}^{{\text{37}}} {\text{Ar}}^{\text{ + }} + {\text{ e}}^ - ,$$ when it takes place in tetrachloroethylene (C₂Cl₄) liquid, is examined in detail. It is concluded that if trapping does take place, the rate is much smaller than the charge neutralization rate. Therefore, this niechanism cannot explain the observed small rate of Ar production in the Brookhaven solar neutrino experiment. A detailed examination of a number of experiments which are sensitive to possible trapping lends strong support to this conclusion.  相似文献   

Early Miocene shell concentration in the mixed carbonate-siliciclastic system of Kutch and their distribution in sequence stratigraphic framework     

Pramod Kumar  Pratul Kumar Saraswati  Santanu Banerjee 《Journal of the Geological Society of India》2009,74(4):432-444

The Early Miocene succession of Kutch represents a mixed carbonate-siliciclastic depositional system. The carbonate part of the succession, characterized by high abundance of shallow marine benthic fauna, hosts typical shell concentrations (also referred as shell beds). The thickness of shell concentrations vary in scale from 5 cm to 100 cm and are separated by poorly fossiliferous to barren silty shales/siltstones. Based on taphonomic and sedimentological observations, shell concentrations are classified as lag, event, composite/multi-event and hiatal types. The occurrence of different types of shell concentrations in the background of sequence stratigraphic framework is the main theme for the present study. Overall, the shell concentrations occupy the middle part of the sequence i.e. upper part of the transgressive systems tract and lower part of the highstand systems tract. Lag concentrations are found in the lower part of the sequence while composite concentrations, the major contributors in the sequence, occur in upper part of the transgressive systems tract and in the lower part of the highstand systems tract. The hiatal concentrations are associated with maximum flooding surface while the position of event concentrations is independent of sequence stratigraphic framework. The shell concentrations occupy marine flooding surface or marine ravinement surface, thus mark parasequence boundaries.  相似文献   

Strange Quark Matter in Cosmic Ray Flux and Exotic Events     

Shibaji Banerjee  Sanjay K. Ghosh  Amal Mazumdar  Sibaji Raha  Debapriyo Syam 《Astrophysics and Space Science》2000,274(3):655-660

There have been several reports of exotic nuclear fragments, with highly unusual charge to mass ratio, in cosmic ray experiments. Although there exist experimental uncertainties which make them, at best, only candidate `exotic' events, it is important to understand what they could be, if they are eventually confirmed. Among other possible explanations, some authors have interpreted them to be lumps of strange quark matter (strangelets).A major problem with such an interpretation is that to reach the earth's surface, they must possess an unusually high penetrability through the terrestrial atmosphere. We show that a recently proposed mechanism for the propagation of strangelets through the earth's atmosphere, together with a proper account of charge capture and ionisation loss, would solve this problem. We also argue that this could lead to viable strategies for definitive detection of strange quark matter in cosmic ray flux using aground based large area array of passive detectors. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Thermoluminescence and optically stimulated luminescence signals from volcanic ash: History of volcanism in Barren Island,Andaman Sea     

D. Banerjee 《Quaternary Geochronology》2010,5(2-3):279-282

The results of experiments which characterise the optically stimulated luminescence (OSL) signals of an ash sample (BI07-TL-05) from Barren Island are presented. The infrared stimulated luminescence signal decreases to 5% of its initial value when preheated at 150 °C for 10 s, suggesting that the infrared stimulated luminescence signal associated with the 290–390 nm emission in this sample arises from a single trap evicted by heating to 150 °C. The post-IR blue stimulated luminescence emission has greater thermal stability and arises from traps which are emptied by heating to temperatures between 120 °C and 240 °C. Dose recovery experiments demonstrate that a laboratory dose can be reliably determined to within 5% for the post-IR blue stimulated luminescence signal. However, the fading rate for the post-IR blue stimulation is high, and the g-value is estimated to be (9.6 ± 3.5)% per logarithmic decade for BI07-TL-05.  相似文献   

Nature and profile distribution of iron and aluminum in relation to pedogenic processes in some soils developed under tropical environment in India     

R. Bera  A. Seal  M. Banerjee  A. K. Dolui 《Environmental Geology》2005,47(2):241-245

Different extractants were used to determine various forms of Fe and Al in three soil profiles developed under a tropical environment in India. The average contents of Fe and Al, extracted by different extracting reagents were found to be in descending order, as follows:Analysis of pyrophosphate (pyr), oxalate (oxa) and dithionate (dith) extractable Fe and Al showed that with increasing soil age, the crystalline Fe and Al oxides increased at the expense of the poorly crystalline forms. The mean content of amorphous Fe and Al, crystalline Fe and Al and their ratio values in the three different soil series estimated the degree of soil development and were found to be in the following descending order: Ghoradanga >Kanchanpur >Lachimpur. Correlation between different forms of Fe and Al and selected soil properties were examined. Multiple regression equations were formulated to show the relation among soil properties and different forms of Fe and Al.  相似文献   

Long-Period Oscillations in Polar Plumes as Observed by cds on Soho     

D. Banerjee  E. O'Shea  J.G. Doyle 《Solar physics》2000,196(1):63-78

We examine spectral time series of the transition region line Ov 629Å, observed with the Coronal Diagnostic Spectrometer (CDS) on the SOHO spacecraft in July 1997. Both Fourier and wavelet transforms have been applied independently to the analysis of plume oscillations in order to find the most reliable periods. The wavelet analysis allows us to derive the duration as well as the periods of the oscillations. Our observations indicate the presence of compressional waves with periods of 10–25 min. We have also detected a 11±1 min periodicity in the network regions of the north polar coronal hole. The waves are produced in short bursts with coherence times of about 30 min. We interpret these oscillations as outward propagating slow magneto-acoustic waves, which may contribute significantly to the heating of the lower corona by compressive dissipation and which may also provide enough energy flux for the acceleration of the fast solar wind. The data support the idea that the same driver is responsible for the network and plume oscillations with the network providing the magnetic channel through which the waves propagate upwards from the lower atmosphere to the plumes.  相似文献   

Polar Plumes and Inter-plume regions as observed by SUMER on SOHO     

Banerjee  D.  Teriaca  L.  Doyle  J.G.  Lemaire  P. 《Solar physics》2000,194(1):43-58

We present observations of Ovi 1032 Å line profiles obtained with the SUMER instrument on SOHO extending from the solar disk to 1.5 R above the limb in the north polar coronal hole. Variations of the intensity and linewidth in the polar plume and inter-plume regions are investigated. We find an anti-correlation between the intensity and the linewidth in the plume and inter-plume regions with detailed plume structures been seen out to 1.5 R . Possible implications regarding the magnetic topologies of these two regions and related heating mechanisms are discussed. The Ovi linewidth measurements are combined with UVCS output to provide an overview of its variations with height extending up to 3.5 R . We find a linear increase of the linewidth from 1 to 1.2 R , then a plateau followed by a sharp increase around 1.5 R .  相似文献   

Evidence for TRM domain wall moments?     

H.-U. Worm  S. K. Banerjee 《Geophysical Journal International》1990,102(2):359-364

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Some cylindrically-symmetric cosmological models in general relativity representing viscous fluid and perfect fluid with heat conduction     

S. R. Roy  S. K. Banerjee 《Astrophysics and Space Science》1988,150(2):213-222

The paper considers inhomogeneous space-times admitting a two-parameter group of motions and satisfying Einstein's field equations for viscous fluid and perfect fluid with heat conduction. Some homogenous solutions representing viscous fluid have also been obtained for which the free-gravitational field is of the magnetic type. Various physical and kinematical properties have been discussed.  相似文献