Soliton and shocks in pair ion plasma in presence of superthermal electron     

Utpal Kumar Samanta  Prasanta Chatterjee  Manimala Mej 《Astrophysics and Space Science》2013,345(2):291-296

Solitons and shocks are addressed in a pair ion plasma in the presence of a kappa distribution. The dissipation is taken care of through the kinematic viscosity of both positive and negative ions in the plasma. The Kadomtsev–Petviashvili–Burger (KPB) equation is derived using the small amplitude expansion method. The Abel equation is obtained from the KPB equation and a solution is obtained by using the factorization method. The effect of the parameters κ and β (temperature ratio of ion species) is observed. Analytically we can find both solitons and shocks. The change of profile from soliton to shocks is shown in the figures. This study may be of wide relevance for the study of the formation of shocks and solitons in laboratory-produced pair ion plasmas.  相似文献   

Head on collision of dust ion acoustic solitary waves in magnetized quantum dusty plasmas     

Malay Kumar Ghorui  Prasanta Chatterjee  C. S. Wong 《Astrophysics and Space Science》2013,343(2):639-645

The Head on collision of dust ion acoustic solitary waves (DIASWs) in a magnetized quantum dusty plasma is investigated. Two sides Korteweg-de Vries (KdV) equations are obtained, the analytical phase shifts and the trajectories after the head-on collision of two DIASWs in a three species quantum dusty plasma are derive by using the extended version of Poincaré-Lighthill-Kuo (PLK) method. It is observed that the phase shifts are significantly affected by the quantum parameters like quantum diffraction, the ion cyclotron frequency and the ratio of the densities of electrons to ions.  相似文献   

Fractional crystallization and mantle-melting controls on calc-alkaline differentiation trends   总被引：10，自引：3，他引：7  

Timothy?L.?GroveEmail author  Linda?T.?Elkins-Tanton  Stephen?W.?Parman  Nilanjan?Chatterjee  Othmar?Müntener  Glenn?A.?Gaetani 《Contributions to Mineralogy and Petrology》2003,145(5):515-533

The phase relations of primitive magnesian andesites and basaltic andesites from the Mt. Shasta region, N California have been determined over a range of pressure and temperature conditions and H₂O contents. The experimental results are used to explore the influence of H₂O and pressure on fractional crystallization and mantle melting behavior in subduction zone environments. At 200-MPa H₂O-saturated conditions the experimentally determined liquid line of descent reproduces the compositional variation found in the Mt. Shasta region lavas. This calc-alkaline differentiation trend begins at the lowest values of FeO*/MgO and the highest SiO₂ contents found in any arc magma system and exhibits only a modest increase in FeO*/MgO with increasing SiO₂. We propose a two-stage process for the origin of these lavas. (1) Extensive hydrous mantle melting produces H₂O-rich (>4.5--6 wt% H₂O) melts that are in equilibrium with a refractory harzburgite (olivine + orthopyroxene) residue. Trace elements and H₂O are contributed from a slab-derived fluid and/or melt. (2) This mantle melt ascends into the overlying crust and undergoes fractional crystallization. Crustal-level differentiation occurs under near-H₂O saturated conditions producing the distinctive high SiO₂ and low FeO*/MgO characteristics of these calc-alkaline andesite and dacite lavas. In a subset of Mt. Shasta region lavas, magnesian pargasitic amphibole provides evidence of high pre-eruptive H₂O contents (>10 wt% H₂O) and lower crustal crystallization pressures (800 MPa). Igneous rocks that possess major and trace element characteristics similar to those of the Mt. Shasta region lavas are found at Adak, Aleutians, Setouchi Belt, Japan, the Mexican Volcanic Belt, Cook Island, Andes and in Archean trondhjemite--tonalite--granodiorite suites (TTG suites). We propose that these magmas also form by hydrous mantle melting.Editorial responsibility: J. Hoefs  相似文献   

Viscous fluid in a kaluza-klein metric     

S. Chatterjee  B. Bhui 《Astrophysics and Space Science》1990,167(1):61-67

Exact solutions are obtained in a five-dimensional space-time with an energy-momentum tensor containing a viscous fluid, assuming either an equation of state or a special form for the viscous term in line with the assumption of Belinskii and Khalatnikov (1977). The solutions are, in fact, generalizations of an earlier work by Grøn for a perfect fluid in the 5D rest-mass varying theory of gravity proposed recently by Wesson. It is found that dimensional reduction of the extra space takes place in some of the cases such that the 5-dimensional universe naturally evolves into an effective 4-dimensional one. A huge amount of entropy can be produced following this shrinkage of extra-dimension which may account for the very large value of entropy per baryon observed in our 4D world. Moreover, the observed constancy of the rest-mass in the present era is also interpreted.  相似文献   

Petrology, geochemistry and tectonic settings of the mafic dikes and sills associated with the evolution of the Proterozoic Cuddapah Basin of south India   总被引：1，自引：0，他引：1  

Nilanjan Chatterjee  Somdev Bhattacharji 《Journal of Earth System Science》2001,110(4):433-453

In this article we summarize the petrological, geochemical and tectonic processes involved in the evolution of the Proterozoic intracratonic Cuddapah basin. We use new and available ages of Cuddapah igneous rocks, together with field, stratigraphic, geophysical and other criteria, to arrive at a plausible model for the timing of these processes during basin evolution. We present petrological and geochronological evidence of dike emplacement along preferred lineament directions around the basin in response to stresses, which may have been responsible for the evolution of the basin itself. Basaltic dike intrusion started on the south Indian shield around 2400 Ma and continued throughout the Cuddapah basin evolution and sedimentation. A deep mantle perturbation, currently manifested by a lopolithic cupola-like intrusion under the southwestern part of the basin, may have occurred at the onset of basin evolution and played an important role in its development. Paleomagnetic, gravity and geochronological evidence indicates that it was a constant thermal source responsible for dike and sill emplacement between 1500 and 1200 Ma both inside and out-side the basin. Lineament reactivation in the NW-SE and NE-SW directions, in response to the mantle perturbation, intensified between 1400 and 1200 Ma, leading to the emplacement of several cross cutting dikes. Fe-Mg partition coefficients of olivine and augite and Ca-Na partition coefficient of plagioclase, calculated from the composition of these minerals and bulk composition of their host rocks, indicate that the dikes outside the Cuddapah basin are cumulates. The contemporary dikes may be related by fractional crystallization as indicated by a positive correlation between their plagioclase Ca# (atomic Ca/[Ca+Na]) and augite Mg# (atomic Mg/[Mg+Fe]). A few NW-SE and NE-SW cross cutting dikes of the period between 1400 and 1200 Ma, preserve petrographic evidence of episodic magmatic intrusive activity along preferred directions. Petrological reasoning indicates that a magmatic liquid reacted with a set of cross cutting dikes, intruding into one that was already solidified and altering the composition of the magma that produced the other dike. The Cuddapah basin tholeiites may be related by fractional crystallization at 5 kb and 1019-1154‡ C, which occurred in the lopolithic cupola near the southwestern margin of the basin. Xenolith bearing picrites, which occur near the periphery of the cupola, originated by the accumulation of xenoliths in the tholeiites. This is indicated by the composition of the olivine in the xenoliths (Fo_78.7-81.9), which are closely similar to calculated olivine compositions (Fo_77.8-78.3) in equilibrium with the tholeiites under the sameP-T conditions. It is inferred that fractionation in the cupola resulted in crystals settling on its walls. Hence, the xenolith-bearing sills occur at the periphery of the lopolithic body. The tholeiites both inside and outside the basin are enriched in incompatible elements compared to mid oceanic ridge basalts. The Ba, Rb and K contents of the Cuddapah and other Proterozoic Gondwana tholeiites indicate that a widespread metasomatic enrichment of the mantle source may have occurred between R∼2.9 and R∼2.7Ga. There may be local heterogeneity in the source of the Cuddapah tholeiites as indicated by different Ba/Rb, Ti/Zr, Ti/Y, Zr/Nb and Y/Nb in samples inside and outside the basin. Large-scale differences such as the low P₂O₅-TiO₂ and high P₂O₅-TiO₂ basaltic domains of the Jurassic Gondwana basalts, however, did not exist during the Proterozoic time period under consideration. Although we are beginning to understand the tectono-magmatic processes involved in the evolution of the Cuddapah basin, much work remains to be done to obtain a complete picture. Future research in the Cuddapah basin should focus on obtaining accurate ages of the igneous rocks associated with the evolution of the basin.  相似文献   

Erosion study of a part of Majuli River-Island using remote sensing data     

Pankaj Mani  Rakesh Kumar  C Chatterjee 《Journal of the Indian Society of Remote Sensing》2003,31(1):12-18

Majuli, the world’s largest river island, is situated in mid of river Brahmaputra in Assam. River Brahmaputra flows in highly braided channels most of them are transient in nature, being submerged during high monsoon flows and changing drastically their geometry and location. Majuli island, home of about 1.3 million people is endangered because of the erratic behavior of the river. In this study, an attempt has been made to observe the trends of erosion in a small part of Majuli island, the area near Kaniajan village in south Majuli- a stretch of about 11 km, using satellite data of 1991, 1997 and 1998. Image processing of digital data has been done in ILWIS software. Supervised for delineation of river from land and then change detection analysis has been done to find out changes in river course from 1991 to 1997 and further from 1997 to 1998. Erosion and deposition maps of the area have been prepared and the erosion of island is measured at various sections at 1 km interval. Erosion of 1900 ha has been observed during the period of six years from 1991 to 1997 and 845 ha during the period of one year from 1997 to 1998.  相似文献   

Synthesis, structure, thermodynamic properties, and stability relations of K-cymrite, K[AlSi3O8]·H2O     

Detlef W. Fasshauer  Niranjan D. Chatterjee  Bernd Marler 《Physics and Chemistry of Minerals》1997,24(6):455-462

Single-phase K-cymrite, K[AlSi₃O₈]·H₂O, has been synthesized in the P-T range 3≤P(GPa)≤4 and 350≤T(°C)≤650, and characterized by a variety of techniques like SEM, FTIR, and ²⁹Si MAS-NMR. Its thermal expansivity and compressibility have been measured up to 375?°C and 6.0?GPa, respectively. Within the uncertainty of the microchemical determination of H₂O by Karl-Fischer titration, it invariably contains 1?mol of H₂O per mol of KAlSi₃O₈. Under the SEM, it appears a small idiomorphic prisms. It is optically negative, with n _o=1.553(1) and n _e=1.521(1). FTIR spectrum identifies the water in its structure as molecular H₂O. Its lattice constants are a=5.3348(1)?Å, c=7.7057(1) Å, V= 189.924 ų, the space group being P6/mmm. The ²⁹Si MAS-NMR suggests a weak short-range order of Al and Si in the symmetrically equivalent tetrahedral sites. A Rietveld structure refinement demonstrates that it is isostructural with cymrite (BaAl₂Si₂O₈·H₂O), the structure comprising double tetrahedral sheets with H₂O molecules residing in their cavities, K serving as an interlayer cation. Whereas cymrite, with its ordered tetrahedral Al/Si distribution, shows a Pm symmetry, the weak short-range Al/Si order in K-cymrite (abbreviated below as KCym) makes it crystallize in the space group P6/mmm. Three reversal experiments on the reaction K[AlSi₃O₈]·H₂O (KCym)=K[AlSi₃O₈] (Kfs)+H₂O, executed in this study, confirm the earlier results of Thompson (1994) and supplement her data. A simultaneous treatment of those reversals, together with the thermodynamic data for Kfs and H₂O available in the literature, helps derive the standard enthalpy of formation (?4233±9.4?kJ/mol) and standard entropy (276.3±10.2 J/K·mol) for K-cymrite. The computed phase relations of KCym in the KAlSi₃O₈-H₂O binary are shown in Figure 4 for three different values of a_{H 2}O. Given a 5?°C/km isotherm in a subducting slab of metasediments in a ultra-high-pressure metamorphic environment, KCym will be expected to grow by hydration of Kfs, unless the a_{H 2}O had been substantially less than 0.5. Nevertheless, how far it can survive exhumation of the subducted terrain will depend critically on the rate of uplifting and on the a_{H 2}O prevailing during that process.  相似文献   

Mobility of arsenic in West Bengal aquifers conducting low and high groundwater arsenic. Part II: Comparative geochemical profile and leaching study     

Bibhash Nath  Zsolt Berner  Debashis Chatterjee  Sukumar Basu Mallik  Doris Stüben 《Applied Geochemistry》2008

Aquifer sediments from areas of low- and high-As groundwater were characterized mineralogically and geochemically at a field site in the Nadia district of West Bengal, India. Leaching experiments and selective extraction of the sediments were also carried out to understand the release mechanism of As in the sub-surface. The correlation between measured elements (major, minor and trace) from low- and high-As groundwater areas are only significant for As, Fe and Mn. The borehole lithology and percentage of silt and clay fraction demonstrates the dominance of finer sediments in the high-As aquifer. Multivariate analysis of the geochemical parameters showed the presence of four different mineral phases (heavy-mineral fraction, phyllosilicates/biotite/Fe-oxyhydroxides, carbonates and sulphides) in the sediments. Selective extraction of sediment reveals that amorphous Fe-oxyhydroxide acts as a potential sink for As in the sub-surface. The result is consistent with microbially mediated redox reactions, which are controlled in part by the presence of natural organic matter within the aquifer sediments. The occurrences of As-bearing redox traps, primarily formed of Fe- and Mn-oxides/hydroxides, are also important factors that control the release of As into groundwater at the study site.  相似文献   

Interacting galaxies and mergers     

Tapan K. Chatterjee 《Astrophysics and Space Science》1993,199(2):189-197

A study of the merger time-scales of various types of interacting galaxies is conducted on the basis of the collisional theory. The results indicate that in the absence of halos, violently interacting galaxies merge in a time-scale of ~ 10⁸ years; but the mildly interacting ones have merger time-scales from ~ 10⁹ to 10¹⁰ years. However, in the presence of halos, all types of interacting galaxies are likely to merge in a time-scale of 10⁸ years (as indicated by preliminary calculations). Galaxy evolution by mutual interactions is likely to have its reflection on the fundamental plane, as during the process the dynamical structures of the progenitors change and dissipation occurs.  相似文献   

A thermodynamic analysis of the system LiAlSiO4-NaAlSiO4-Al2O3-SiO2-H2O based on new heat capacity, thermal expansion, and compressibility data for selected phases     

Detlef W. Fasshauer  Niranjan D. Chatterjee  Ladislav Cemic 《Contributions to Mineralogy and Petrology》1998,133(1-2):186-198

Heat capacity, thermal expansion, and compressibility data have been obtained for a number of selected phases of the system NaAlSiO₄-LiAlSiO₄-Al₂O₃-SiO₂-H₂O. All C _p measurements have been executed by DSC in the temperature range 133–823 K. The data for T ≥ 223 K have been fitted to the function C _p (T) = a + cT ⁻² + dT ^−0.5 + fT ⁻³, the fit parameters being The thermal expansion data (up to 525 °C) have been fitted to the function V ⁰(T) = V ⁰(T) [1 + v ₁ (T−T ⁰) + v ₂ (T−T ⁰)²], with T ⁰ = 298.15 K. The room-temperature compressibility data (up to 6 GPa) have been smoothed by the Murnaghan equation of state. The resulting parameters are These data, along with other phase property and reaction reversal data from the literature, have been simultaneously processed by the Bayes method to derive an internally consistent thermodynamic dataset (see Tables 6 and 7) for the NaAlSiO₄-LiAlSiO₄-Al₂O₃-SiO₂-H₂O quinary. Phase diagrams generated from this dataset are compatible with cookeite-, ephesite-, and paragonite-bearing assemblages observed in metabauxites and common metasediments. Phase diagrams obtained from the same database are also in agreement with the cookeite-free, petalite-, spodumene-, eucryptite-, and bikitaite-bearing assemblages known to develop in the subsolidus phase of recrystallization of␣lithium-bearing pegmatites. It is gratifying to note that the cookeite phase relations predicted earlier by Vidal and Goffé (1991) in the context of the system Li₂O-Al₂O₃-SiO₂-H₂O agree with our results in a general way. Received: 19 May 1998 / Accepted: 25 June 1998  相似文献