Effect of Stellar Wind and Poynting–Robertson Drag on Photogravitational Elliptic Restricted Three Body Problem     

A. Chakraborty  A. Narayan 《Solar System Research》2018,52(2):168-179

The existence and linear stability of the planar equilibrium points for photogravitational elliptical restricted three body problem is investigated in this paper. Assuming that the primaries, one of which is radiating are rotating in an elliptical orbit around their common center of mass. The effect of the radiation pressure, forces due to stellar wind and Poynting–Robertson drag on the dust particles are considered. The location of the five equilibrium points are found using analytical methods. It is observed that the collinear equilibrium points L₁, L₂ and L₃ do not lie on the line joining the primaries but are shifted along the y-coordinate. The instability of the libration points due to the presence of the drag forces is demonstrated by Lyapunov’s first method of stability.  相似文献   

Seafloor Geomorphology and Processes on the Western Continental Margin of India based on Multibeam Acoustic Backscatter Data Analysis     

Sumanta Dandapath  Andrew Menezes  Bishwajit Chakraborty  John Kurian  Koppella N. Prudhvi Raju 《Marine Geodesy》2018,41(2):177-200

An assessment of the multibeam sonar data of the central Western Continental Margins of India has been carried out to evaluate the seafloor geomorphology and processes by examining the geomorphological attributes e.g., slope, sediments, structures, etc. associated with geomorphic features. The variation in relief and the features located in the region have been mapped and interpreted collectively by utilizing several geospatial mapping tools. The backscatter strength across the area, apparently congruent with the local relief, has helped to examine the sediment movement on the seafloor. The prominent features found in the region include faults, pockmarks, mounds, submarine terraces, and submerged fossil reefs. Several areas with varying topography engender comparable fractal dimension at short scale breaks, and the probability density functions (PDFs) utilizing backscatter data depicting overlapping classes. The present study highlights how fractals and scale break parameters can be utilized to determine the seafloor processes and associated sedimentological dynamics in a complex geographical environment with strong bottom currents, seasonal upwelling, and faulted structure. The role and impact of the various geomorphic processes on the reworking of sediment movement and the overall progression of the seafloor morphology has been revealed for the first time in this part of the ocean bottom.  相似文献   

Study of magnetic field geometry and extinction in Bok globule CB130     

A. Chakraborty  H. S. Das 《Astrophysics and Space Science》2016,361(9):321

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Hazardous air pollutants and flooding: a comparative interurban study of environmental injustice   总被引：1，自引：0，他引：1  

Sara Grineski  Timothy W. Collins  Jayajit Chakraborty  Marilyn Montgomery 《GeoJournal》2015,80(1):145-158

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New technologies, old divides: linking internet access to social and locational characteristics of US farms     

Pratyusha Basu  Jayajit Chakraborty 《GeoJournal》2011,76(5):469-481

Access to new information and communication technologies is widely viewed as a prerequisite for participation in the global economy, so that inequalities in such access have become a significant policy concern. Rural areas are especially underserved in terms of internet providers, and this is true in both developed and less developed economies. This article focuses on access to the internet within farming operations in the US as an important aspect of understanding the digital divide within rural areas. Using county level data from the 2007 US Census of Agriculture and multivariate regression analysis, our study examines the statistical relationship between farm internet access and a set of explanatory factors which include demographic characteristics of operators, economic characteristics of farms, and geographic location (region and metropolitan status) of the farm. Further, it seeks to understand whether access to the internet can be socially and locationally differentiated from access to high speed internet. Our findings indicate that existing social divides are replicated in terms of the digital divide, so that social inequalities are potentially a more pressing problem than infrastructural gaps in terms of rural access to the internet in the US.  相似文献   

A multi-method approach for the study of lanthanum speciation in coastal and estuarine sediments     

Parthasarathi Chakraborty  P.V. Raghunadh BabuV.V. Sarma 《Journal of Geochemical Exploration》2011

Two independent analytical methods (sequential extraction and kinetic extraction methods) were applied in order to understand the distribution and speciation of La in the coastal and estuarine sediments from the central east coast of India. Sequential extraction study revealed that La was primarily present as inert complexes (~ 50–60% of the total La) in all the sediments. Amounts of ~ 20–30% of the total La in all the sediments were found to associate with the total organic carbon (TOC) in the sediments. The dissociation rate constants of La–sediment complexes obtained from kinetic extraction studies revealed that the concentration of thermodynamically weak complexes of La gradually increased with the increasing La/TOC ratio in the sediments.  相似文献   

Movement of seasonal eddies and its relation with cyclonic heat potential and cyclogenesis points in the Bay of Bengal     

Bishnu Kumar  Arun Chakraborty 《Natural Hazards》2011,59(3):1671-1689

Movement of seasonal eddies in the Bay of Bengal (BOB) and its relation with cyclonic heat potential (CHP) and cyclogenesis points have been investigated in this study using 6 years (2002–2007) of global ocean monthly analysis datasets based on the Simple Ocean Data Assimilation (SODA) package (SODA v2.0.4) of Carton et al. (2005) and Indian Meteorological Department cyclogenesis points. The region dominated by anticyclonic eddies with CHP greater than 70 × 10⁷ J/m² as well as good correlations (>0.9) with sea surface height (SSH) and 26°C isothermal depth (D ₂₆) can be a potential region of cyclogenesis. The region dominated by cyclonic eddies with CHP greater than 50 × 10⁷ J/m² and good correlation (>0.9) with both SSH and D ₂₆ can serve as a potential region of high-level depression. Potential cyclogenesis regions are the southern BOB (5°N–12°N) for the post-monsoon season and the head of BOB (north of 15°N) during southwest monsoon. Seven potential regions are identified for the eddy formation for different seasons, which are consistent with the cyclogenesis points. The CHP distributions alone are able to explain the cyclone tracks for the pre-monsoon and post-monsoon seasons but not for the monsoon season.  相似文献   

Equatorial ionospheric responses in relation to the occurrence of main phase of intense geomagnetic storms in the local dusk sector     

R. Hajra  S.K. Chakraborty 《Journal of Atmospheric and Solar》2011,73(7-8):760-770

During five intense geomagnetic storms with main phases occurring around local dusk sector, equatorial ionosonde and electrojet data, VHF/UHF scintillation data of Calcutta, and several solar wind parameters are investigated to ascertain the polarity of prompt penetration electric field (PPEF). Abrupt increases in AE, ASY-H and/or sharp decreases in D_st/SYM-H with strong southward IMF B_z may symbolize eastward PPEF to equatorial latitude leading to evolution of density irregularities if the period is associated with arrival and sustenance of large magnetospheric shock compression. On the contrary, westward PPEF is more feasible if the shock reduces suddenly or fluctuates with small values.  相似文献   

Characterization of Kota Sandstone Under Different Strain Rates in Uniaxial Loading     

Md. Shams Alam  Tanusree Chakraborty  Vasant Matsagar  K. Seshagiri Rao  Prince Sharma  Manjit Singh 《Geotechnical and Geological Engineering》2015,33(1):143-152

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Study of lapse time dependence coda Q in the Andaman Islands using the aftershocks of the 2002 earthquake (M w 6.5)     

Chandrani Singh  Sagarika Mukhopadhyay  Sagar Singh  Pranab Chakraborty  J. R. Kayal 《Natural Hazards》2015,75(1):779-793

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