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D. C. Singhal V. K. Sharma Manish Tungaria 《Journal of the Geological Society of India》2016,88(4):449-463
In the present case study, impact of urbanization and industrial development on the shallow groundwater regime of Saharanpur town of Uttar Pradesh in India is examined with the aim of planning groundwater protection for better governance. The hazardous physicochemical and bacteriological parameters and heavy metals detected in the shallow aquifer include harmful pathogens like fecal coliforms, heavy metals like cadmium, chromium, nitrates and sulphates. An assessment of ground water vulnerability using the well known DRASTIC method has confirmed that the shallow groundwater in some central and southern localities of Saharanpur town fall in the medium risk zones. Further, using field data of 32 electrical resistivity soundings, the protective capacity of the unconfined aquifer is assessed in terms of a ‘total longitudinal conductance’ of the semi-pervious to impervious sediments overlying the unconfined aquifer. However, some areas aligned along a northwest-southeast and in the western parts of the town seem to have relatively higher protective capacity against infiltrating waste pollutants. A ground water protection planning map prepared by combining the DRASTIC map and the ‘potentially hazardous pollutants’ map has brought out the need to install eleven new groundwater quality monitoring wells in the town at locations near the line sources and point sources of pollution. This approach can be readily employed by the decision makers in framing sound guidelines for groundwater protection and governance. 相似文献
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The Paleogene sections of Kutch are the reference for the regional chronostratigraphic units of India. The ages of these dominantly shallow marine carbonates are mainly based on larger benthic foraminifera (LBF). The taxonomic revisions of the LBF and the progressively refined shallow benthic zonations (SBZ) have necessitated the present study on updating the stratigraphy of the area. The sedimentation in Kutch commenced with the deposition of volcaniclastics in terrestrial environments in the Paleocene. The marine transgression in SBZ 5/6 deposited finer clastics and carbonates, designated as Naredi Formation, in early Eocene. There is no evidence of marine Paleocene in Kutch. A major hiatus spanning SBZ 12 to SBZ 16 was followed by the development of a carbonate platform and deposition of Harudi Formation – Fulra Limestone during the Bartonian, SBZ 17. The hiatus corresponds to a widespread stratigraphic break in Pakistan and India to Australia, referred as the ‘Lutetian Gap.’ The Maniyara Fort Formation is assigned to SBZ 22 B and SBZ 23, and its age is revised to Chattian. Climate played a major role in building up of the Paleogene stratigraphic succession of Kutch, the carbonates formed during the warming intervals and the stratigraphic gaps were in the intervening cooling periods. 相似文献
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Application of dried plant biomass as novel low-cost adsorbent for removal of cadmium from aqueous solution 总被引：1，自引：1，他引：0
A. Dubey A. Mishra S. Singhal 《International Journal of Environmental Science and Technology》2014,11(4):1043-1050
Heavy metals are a threat to human health and ecosystem. These days, great deal of attention is being given to green technologies for purification of water contaminated with heavy metal ions. Biosorption is one among such emerging technologies, which utilizes naturally occurring waste materials to sequester heavy metals from wastewater. Cadmium has hazardous impact on living beings; therefore, its removal through green and economical process is an important task. The aim of the present study was to utilize the locally available Portulaca oleracea plant biomass as an adsorbent for cadmium removal from aqueous solution. The biomass was obtained after drying and grinding the portulaca leaves and stem. No chemical treatment was done on the adsorbent so that it remained green in a true sense. Batch experiments were performed at room temperature. The critical parameters studied were effects of pH, contact time, initial metal ion concentration and adsorbent dose on the adsorption of cadmium. The maximum adsorption was found to be 72 %. The kinetic data were found to best fit the pseudo-second-order equation. High adsorption rates were obtained in the initial 45 min, and adsorption equilibrium was then gradually achieved in about 100 min. Adsorption increased with increase in pH for a range 2 and 6. The equilibrium adsorption results closely followed both the Langmuir and Freundlich isotherms. The values of constants were calculated from isotherms. Results indicated that portulaca plant biomass could be developed as a potential material to be used in green water treatment devices for removal of metal ions. 相似文献
4.
The problem of thermal convection instability of a horizontal layer of magnetized fluid has been studied to occur crystal growing under the effect of horizontal temperature gradient. In the study, the problem has been reduced to an eigen-value problem for a stream function. The dispersion relations for low viscosity fluid and high viscosity fluid respectively have been discussed analytically and some numerical results have been obtained. It is shown that the critical Rayleigh number and other its related constants for low viscosity fluid (i.e., mercury) are much differ than the high viscosity fluid (i.e., glycerol). 相似文献
5.
The elements of dielectric tensor and dispersion relation for obliquely propagating whistler waves with finite in an infinite magnetoplasma are obtained for a kappa distribution in the presence of perpendicular a.c. electric field.
Integrals and modified plasma dispersion functions are reduced in power series form. Numerical calculations have been performed
to obtain temporal growth rate and real frequencies of the plasma waves for magnetospheric plasma, using linear theory of
dispersion relation. The effect and modification introduced by the perpendicular a.c. electric field on the temporal growth
rates, real frequencies and resonance condition are discussed for kappa and Maxwellian distributions. Our results and their
interpretation are compared with known whistler observations obtained by ground-based techniques and satellite observations. 相似文献
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We have investigated the role of group velocity in the calculation of pitch-angle diffusion coefficients by electron cyclotron harmonic (ECH) waves in planetary magnetospheres. The assumption which is generally made that the parallel group velocity can be neglected in comparison with particle parallel velocity is examined in detail. It is found that for lowest harmonic band this assumption is quite good. It is found that in general it is not possible to ignore the parallel group velocity. However, for lowest harmonic band this assumption is quite good at low electron temperatures. 相似文献
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Acta Geotechnica - This paper presents a procedure for evaluating the load–displacement behavior of tapered piles under static axial compressive loads. The response of tapered piles under... 相似文献
9.
In‐plane and out‐of‐plane behavior of confined masonry walls for various toothing and openings details and prediction of their strength and stiffness 
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下载免费PDF全文 Eight half‐scale brick masonry walls were tested to study two important aspects of confined masonry (CM) walls related to its seismic behavior under in‐plane and out‐of‐plane loads. Four solid wall specimens tested to investigate the role of type of interface between the masonry and tie‐columns, such as toothing varying from none to every course. The other four specimens with openings were tested to study the effectiveness of various strengthening options around opening to mitigate their negative influence. In the set of four walls, one wall was infilled frame while the other three were CM walls of different configurations. The experimental results were further used to determine the accuracy of various existing models in predicting the in‐plane response quantities of CM walls. Confined masonry walls maintained structural integrity even when severely damaged and performed much better than infill frames. No significant effect of toothing details was noticed although toothing at every brick course was preferred for better post‐peak response. For perforated walls, provision of vertical elements along with continuous horizontal bands around openings was more effective in improving the overall response. Several empirical and semi‐empirical equations are available to estimate the lateral strength and stiffness of CM walls, but those including the contribution of longitudinal reinforcement in tie‐columns provided better predictions. The available equations along with reduction factors proposed for infills could not provide good estimates of strength and stiffness for perforated CM walls. However, recently proposed relations correlating strength/stiffness with the degree of confinement provided reasonable predictions for all wall specimens. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
10.
A coupled chemistry–transport model is developed to study the production and loss of neutral atomic carbon and oxygen in the inner coma (≤104km) of Comet Halley. Subsequently, the generation of OI 1304 Å and OI 1356 Å and CI 1561 Å and CI 1657 Å emissions is studied. Calculations are performed utilizing solar EUV, utilizing photoelectrons, and assuming the precipitation of high energy “auroral” electrons of solar wind origin, the evidence for which has been inferred from many observations, as the sources for the production of these atoms and emissions, including only the gas phase species in the cometary coma. It is revealed that the electron impact dissociation of parent species could be a potentially important source of C and O production and their emissions in the inner cometary coma. Our calculated O density profile is in agreement with that calculated by R. R. Hodges, Jr. (1990,Icarus83, 410–433). The present study has demonstrated the importance of contributions from sources other than the solar fluorescence for deriving the O and C production rates from their emission line brightness. It is found that the electron impact and solar fluorescence contribute 34 and 66%, respectively, to the OI 1304 Å emission. However, when the auroral electrons are also included, the relative contributions of electron impact and solar fluorescence are 72 and 28%, respectively. In the case of CI 1657 Å the electron impact contribution amounts to 24 (18)% with (without) inclusion of auroral electrons. 相似文献