Chemometric analysis to infer hydro-geochemical processes in a semi-arid region of India   总被引：1，自引：0，他引：1  

Chander Kumar Singh  Satyanarayan Shashtri  Kumari Rina  Saumitra Mukherjee 《Arabian Journal of Geosciences》2013,6(8):2915-2932

Groundwater exploitation in Punjab has increased in last few decades due to rapid increase in industrialization, population, crop production, and erratic monsoon. In the present study, groundwater samples from 29 locations were collected and analyzed for almost all major anions, cations, and heavy metals. The analyzed parameters formed the attribute database for statistical analysis. The study approach included multivariate statistical analysis of hydro-chemical data to identify hydro-geochemical processes occurring in the study area and its relation to groundwater quality. The principal component analysis produced seven significant factors that explained nearly 77 % of the cumulative variance. Factor 1 explained nearly 22.05 % of dataset with variables loading indicating mineralization of geological component of soil. Trilinear plot and other graphical methods were also used to identify chemical facies of groundwater and geochemical processes occurring in study area. The water type in the study area is of Na/K–Mg–HCO₃ type. It was found that the general hydro-geochemistry of groundwater in the study area dominated is by the processes such as carbonate/silicate weathering, ion-exchange, and dissolution. Thus, statistical methods can prove to be an effective tool understanding hydro-geochemistry of a region along with conventional graphical methods.  相似文献   

Evaluation of seismogenesis behavior in Himalayan belt using data mining tools for forecasting     

Pushan Kumar Dutta  O. P. Mishra  Mrinal Kanti Naskar 《Central European Journal of Geosciences》2013,5(2):236-253

  相似文献   

Textural and Mineralogical Characteristics of the Beach Sands of Tamil Nadu, Southern India     

C.G. Chandrasekaran  K.V. Muralidharan  K. Joshi Nirmal Kumar 《Gondwana Research》2001,4(4):588

  相似文献   

Observations of intensity oscillations in a prominence-like cool loop system as observed by SDO/AIA: evidence of multiple harmonics of fast magnetoacoustic waves     

A. K. Srivastava  B. N. Dwivedi  Mukul Kumar 《Astrophysics and Space Science》2013,345(1):25-32

Using SDO/AIA 304 Å channel, we study the evolution of weak intensity oscillations in a prominence like cool loop system observed at North-West limb on 7 March 2011. We use the standard wavelet tool to produce statistically significant power spectra of AIA 304 Å normalized fluxes derived respectively near the apex and footpoint of the fluxtube. We find periodicities of ≈667 s and ≈305 s respectively near apex and above footpoint with significance level >98 %. Observed statistically significant periodicities in the tube of projected length ≈170 Mm and width ≈10 Mm, are interpreted as most likely signature of evolution of various harmonics of tubular fast magnetoacoustic waves. Sausage modes are unlikely though they are compressive as they need bulky and highly denser loop system for their evolution for sustaining such large periods. We interpret the observed periodicities as multiple harmonics (fundamental and first) of fast magnetoacoustic kink waves that can generate some weak density perturbations (thus intensity oscillations) in the tube and can be observed pertaining to periodic variation in plasma column depth as tube is oblique in projection with respect to line-of-sight. The period ratio P ₁/P ₂=2.18 is observed in the fluxtube, which is the signature of the magnetic field divergence of the cool loop system. We estimate tube expansion factor as 1.27 which is typical of EUV bipolar loops in the solar atmosphere. We estimate the lower bound average magnetic fields ranging from ≈9 to 90 Gauss depending upon typical densities as 10⁹–10¹¹ cm^?3 in the observed prominence-like cool loop system. We also observe the first signature of lowering fundamental mode period by a factor 0.85 due to cooling of this loop system.  相似文献   

Head-on collisions of ion-acoustic Korteweg-de Vries/modified Korteweg-de Vries solitons in a magnetized quantum electron-positron-ion plasma     

Malay Kumar Ghorui  Utpal Kumar Samanta  Prasanta Chatterjee 《Astrophysics and Space Science》2013,345(2):273-281

  相似文献   

Bianchi type-V cosmological model with purely magnetic solution     

Rajesh Kumar  S. K. Srivastava 《Astrophysics and Space Science》2013,346(2):567-572

In the present paper we study some new aspects of the Bianchi type-V space time. The Electric and Magnetic parts of Weyl tensors are calculated in terms of tilted congruence and discussed the purely magnetic Weyl tensor. Einstein field equations for purely magnetic space time are obtained and solution of such field equations called purely magnetic solution. To get deterministic solutions of the field equations we consider a new law of variation of average scale factor which yields time dependent deceleration parameter. Certain physical and geometrical properties of the model are also discussed.  相似文献   

Multiwavelength Study of a Solar Eruption from AR NOAA 11112: II. Large-Scale Coronal Wave and Loop Oscillation     

Pankaj Kumar  K.-S. Cho  P. F. Chen  S.-C. Bong  Sung-Hong Park 《Solar physics》2013,282(2):523-541

We analyze multiwavelength observations of an M2.9/1N flare that occurred in AR NOAA 11112 on 16 October 2010. AIA 211 Å EUV images reveal the presence of a faster coronal wave (decelerating from ≈?1390 to ≈?830 km?s^?1) propagating ahead of a slower wave (decelerating from ≈?416 to ≈?166 km?s^?1) towards the western limb. The dynamic radio spectrum from Sagamore Hill radio telescope shows the presence of a metric type II radio burst, which reveals the presence of a coronal shock wave (speed ≈?800 km?s^?1). The speed of the faster coronal wave, derived from AIA 211 Å images, is found to be comparable to the coronal shock speed. AIA 171 Å high-cadence observations showed that a coronal loop, which was located at a distance of ≈?0.32R _⊙ to the west of the flaring region, started to oscillate by the end of the impulsive phase of the flare. The results indicate that the faster coronal wave may be the first driver of the transversal oscillations of coronal loop. As the slower wave passed through the coronal loop, the oscillations became even stronger. There was a plasmoid eruption observed in EUV and a white-light CME was recorded, having velocity of ≈?340?–?350 km?s^?1. STEREO 195 Å images show an EIT wave, propagating in the same direction as the lower-speed coronal wave observed in AIA, but decelerating from ≈?320 to ≈?254 km?s^?1. These observations reveal the co-existence of both waves (i.e. coronal Moreton and EIT waves), and the type II radio burst seems to be associated with the coronal Moreton wave.  相似文献   

Some anisotropic dark energy models in Bianchi type-V space-time     

Anil Kumar Yadav 《Astrophysics and Space Science》2011,335(2):565-575

The paper deals with Bianchi type V Universe, which has dynamical energy density. We consider Bianchi type V space-time, introducing three different skewness parameters along spatial directions to quantify the deviation of pressure from isotropy. To study the anisotropic nature of the dynamical dark energy, we assume that the skewness parameters are time dependent. It is found that the Universe achieves flatness in quintessence model. The physical behavior of the Universe has been discussed in detail.  相似文献   

A family of well behaved charge analogues of?a?well behaved neutral solution in?general relativity     

Sunil Kumar Maurya  Y. K. Gupta 《Astrophysics and Space Science》2011,332(2):481-490

A family of charge analogues of a neutral solution with g ₄₄=(1+Cr ²)⁶ has been obtained by using a specific electric intensity, which involves a parameter K. Both neutral and charged solutions are analysed physically subject to the surface density 2×10¹⁴ gm/cm³ (neutron star). The neutral solution is well behaved for 0.0<Ca ²≤0.10477 while its charge analogues are well behaved for a wide range of a parameter K (0≤K≤72) i.e. pressure, density, pressure-density ratio, velocity of sound is monotonically decreasing and the electric intensity is monotonically increasing in nature for the given range of the parameter K. The maximum mass and radius occupied by the neutral solution are 3.4126M _Θ and 18.9227 km for Ca ²=0.10447 respectively. While the red shift at centre Z ₀=0.9686 and red shift at the surface Z _a =0.4612. For the charged solution, the maximum mass and radius are 5.6111M _Θ and 17.2992 km respectively for K=3.0130 and Ca ²=0.2500, with the red shift Z ₀=3.0113 and Z _a =1.0538.  相似文献   

Seismic source zonation for NE India on the basis of past EQs and spatial distribution of seismicity parameters     

Borah  Niranjan  Kumar  Abhishek  Dhanotiya  Rajat 《Journal of Seismology》2021,25(6):1483-1506

Journal of Seismology - The North East (NE) of India is an earthquake (EQ) prone zone and has experienced considerable damages in the past due to high intensity EQs. With rapidly growing...  相似文献