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11.
Syed Hilal Farooq Pintu Prusty Raj Kumar Singh Subhajit Sen Dornadula Chandrasekharam 《Arabian Journal of Geosciences》2018,11(22):709
The contamination of aquifers by fluoride and arsenic is a major cause of concern in several parts of India. A study has thus been conducted to evaluate the extent and severity of fluoride contamination and also its seasonal variability. Two blocks (Purulia-1 and Purulia-2) were considered for this purpose. Twenty groundwater samples (in each season) were collected from tube wells during the pre-monsoon and post-monsoon seasons. In addition to fluoride, groundwater samples were also analyzed for major cations, anions, and other trace elements. The concentration of fluoride shows significant seasonal variation and ranges between 0.94–2.52 and 0.25–1.43 mg/l during the pre-monsoon and post-monsoon seasons, respectively. In pre-monsoon season, more than 40% of the water samples show fluoride concentrations higher than the WHO limit. However, during the post-monsoon season, none of the groundwater sample shows fluoride concentrations higher than the WHO limit. Lesser concentration during the post-monsoon season is attributed to the dilution effect by the percolating rainwater, which has also been reflected in the form of a decrease in concentrations of other elements. The petrographic studies of the rock samples collected from the study area show that the rocks are mainly composed of plagioclase, orthoclase, and quartz with abundant biotite. The weathering and dissolution of biotite plays an important role in controlling the fluoride concentrations in the groundwater of the study area. 相似文献
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Geophysical signatures resolving hydrogeological complexities over hard rock terrain—a study from Southern India 总被引：1，自引：0，他引：1
Sahebrao Sonkamble Subash Chandra E. Nagaiah Farooq A. Dar V. K. Somvanshi Shakeel Ahmed 《Arabian Journal of Geosciences》2014,7(6):2249-2256
A series of geophysical parameters have been applied with geological perception to resolve the hydrogeological complexities over granitic terrain at Hyderabad, India. Frequent failure of borehole drillings and the thrust conditions of community have prompted a noninvasive suitable tool, applied at small scale for pinpointing potential well site. Geophysical scanning, viz. electrical resistivity tomography (ERT), spontaneous potential (SP), and electrical gradient profiling (GP) were employed within the restricted space of housing complex to obtain the true characteristics of the subsurface lithology, where anomalies by the underground utility structures have been nullified. Results showed, in ERT, the low order of resistivity range 123 to 200?Ωm showing a plume like weathered zone underlain by sudden slip of massive granite (>217?Ωm) was of great interest to proceed further in the process. Here, the switchover in SP value from +18 mV to ?17 mV and GP from mean value 10 to 90 mV/m was recorded. The anomalies in SP and GP were precisely coincided with the ERT where upcoming of subsurface massive granite next to the inferred fracture was noted. Drilling core logs satisfies the geophysical signatures ensuring the inferred saturated fracture with the total yield 1,302 gal/h. 相似文献
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We present models, in which phantom energy interacts with two different types of dark energies including variable modified
Chaplygin gas (VMCG) and new modified Chaplygin gas (NMCG). We then construct potentials for these cases. It has been shown
that the potential of the phantom field decreases from a higher value with the evolution of the Universe. 相似文献
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Manzoor?A.?MalikEmail author Raja?Nisar?Ali Farooq?Ahmad 《Astrophysics and Space Science》2011,336(2):447-454
We derive the distribution function and the allied thermodynamic quantities for a system of galaxies with three mass species.
A new clustering parameter b
3 that inherently takes into account the masses and the number of galaxies of each kind, emerges directly from the calculations.
Our general conclusion is that the inclusion of the third component does not significantly effect the overall features of
the distribution function. 相似文献
16.
S.H. Farooq D. Chandrasekharam G. Abbt-Braun Z. Berner S. Norra D. Stüben 《Applied Geochemistry》2012
Dissolved organic C (DOC) plays an important role in the mobilization of As from sediments. In West Bengal, the widely used technique for obtaining jute fiber involves retting of the jute plant in ponds (hereafter such ponds are termed jute decomposing ponds) for several weeks, which produces significant amounts of DOC in the ponds. These ponds thus act as point sources of DOC and supply huge quantities of organic C to the Bengal Delta sediments. This study has been carried out to investigate the role of such DOC in enriching the groundwater with As in the Bengal Delta. Data clearly show that due to the effect of DOC, As is mobilized from the upper 2.6 m of the sediment profile, and is fixed between 2.6 and 6.1 m, while the lower part (6.1–9 m) largely remains unaffected. The reducing conditions mainly developed due to the decay of the percolating DOC seem to help the mobilization and transportation of As and other redox sensitive elements (Fe, Mn), as well as elements (Cu, Zn) attached to oxy-hydroxides of those redox-sensitive elements. Experiments also indicate that if the DOC production at the surface continues for a longer period of time, the zone of As fixation (2.6–6.1 m) may get shifted further downwards and ultimately intercept the water table resulting in As enrichment of groundwater. 相似文献
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This study records length-weight relationships(LWRs)for eleven commercially important marine catfi sh species of the family Ariidae(sea catfi shes)and Plotosidae(eel catfi shes)from the northern Arabian Sea coast of Pakistan.The specimens were sampled from December 2014 to November 2015,using bottom trawls with various mesh sizes by commercial vessels.The species were Nemapteryx caelatus,Sciades sona,Arius gagora,Batrachocephalus mino,Netuma thalassina,N.bilineata,Osteogeneiosus militaris,Plicofollis dussumieri,P.tenuispinis,Plotosus limbatus,and P.lineatus.Of the eleven species,two species A.gagora and N.bilineata were recorded for the fi rst time and LWRs for four species A.gagora,N.bilineata,S.sona,and B.mino still have no data in the Fish Base database.In addition,new maximum length for each of the three species N.bilineata,O.militaris and B.m ino was also found. 相似文献
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Muhammad Saeed Komal Farooq Muhammad Nafees Muhammad Arshad Mohammad Salim Akhter Amir Waseem 《洁净——土壤、空气、水》2020,48(9)
In the current study the application of organo‐modified bentonite for the adsorption of mycotoxins (aflatoxin B1, citrinin, patulin, and zearalenone) is presented. The modification of clays is carried out using benzyl‐tri‐n‐butyl ammonium bromide (BTB), benzethonium chloride (BTC), and dioctyl sodium sulfosuccinate (DSS). Various experimental parameters such as pH, time, adsorbent dose, and mycotoxins concentration are thoroughly studied. The modified clays (B‐BTB, B‐BTC and B‐DSS) are characterized by X‐ray fluorescence, X‐ray diffraction, and Fourier transform infrared spectroscopy. The results depicted the high detoxification efficiency (≈99%) of modified clays for the removal of mycotoxins under optimized conditions (pH 5, time: 30 min, adsorbent amount: 50 mg). The adsorption capacities of modified clays are found in the order of: B‐BTC (AFB1: 18.02, CIT: 18.35, PAT: 18.21, ZEA: 18.09 mg g?1) > B‐BTB (AFB1: 17.7, CIT: 18.11, PAT: 17.95, ZEA: 17.90 mg g?1) > B‐DSS (AFB1: 17.5, CIT: 18.02, PAT: 17.86, ZEA: 17.80 mg g?1). The obtained results fitted well with thermodynamic, isothermal (Langmuir) and pseudo‐second order kinetics. Low cost organo‐modified bentonite shows the promise in mitigating mycotoxin contamination, which could improve food safety and reduce environmental contamination. 相似文献
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Cosmic energy equation is an important equation for studying the gravitational galaxy clustering in the expanding universe.
We derive the distribution function for fluctuations in particle number by using the cosmic energy equation for extended structures
(galaxies with halos). From spatial distribution function, containing particle fluctuations, we derive the velocity distribution
function to understand the influence of particle fluctuations on the velocities of galaxies.With the help of cosmic energy
equation we try to find out the physical constraints for the application of quasi-equilibrium approximation. 相似文献