Developing a biosorbent from <Emphasis Type="Italic">Aegle Marmelos</Emphasis> leaves for removal of methylene blue from water     

S. Baruah  A. Devi  K. G. Bhattacharyya  A. Sarma 《International Journal of Environmental Science and Technology》2017,14(2):341-352

Dried, mature leaves of Aegle Marmelos tree were converted to a powder, which was used as a biosorbent for dyes in water with methylene blue as a case study. The biosorbent had a surface area of 52.63 mg/g, and FTIR spectra showed the presence of –COOH, –NH₂, –R–SC=O (thioester) and R1–S(=O, =O)-N(–R2, –R3) groups on the surface. The particles were found to be porous in nature from scanning electron micrographs, and EDX measurements showed the elements C, O, Na, Mg, K, Ca and Fe on the surface. Batch adsorption experiments showed that the adsorption of the dye was preferred at near-neutral conditions. Adsorption equilibrium was achieved in ~120 min with maximum dye uptake of 19.9 mg/g. Investigation into the kinetics of adsorption indicated that second-order kinetics gave the best fit to the experimental data, and a rate coefficient of 8.0 × 10^?2 to 32.3 × 10^?2 g mg^?1 min^?1 was obtained.  相似文献   

Static deformation of a uniform half-space due to a long dip-slip fault     

Sunita Rani  Sarva Jit Singh 《Geophysical Journal International》1992,109(2):469-476

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Evaluation of the Comparative Toxicity of Thiotox,Dichlorvos and Carbofuran to Two Fresh Water Teleosts Ophiocephalus punctatus and Mystus Vittatus     

S. R. Verma  Sarita Rani  S. K. Bansal  R. C. Dalela 《洁净——土壤、空气、水》1981,9(2):119-129

The present study was undertaken to evaluate the comparative toxicity of Thiotox (Endosulfan) (an organochlorine), Dichlorvos (DDVP) (an organophosphorus) and Carbofuran (a carbamate) so as to determine the TL 50 values, acute toxicity ranges, relative toxicities, relative susceptibility, safe concentrations, regression equations, heterogeneity factor and 95% confidence limits for the period of 24, 48, 72 and 96 h, taking two fresh water teleosts, Mystus vittatus and Ophiocephalus punctatus as test animals. From the relative toxicity of these pesticides it is evident that thiotox was the most toxic and dichlorvos the least toxic one, while the toxicity of carbofuran was in between these two extremes for both the fishes. On the basis of relative susceptibility, Mystus vittatus was found to be more susceptible than Ophiocephalus punctatus for thiotox, dichlorvos and carbofuran, respectively. The safe concentrations were computed for all the three pesticides taking different application factors, so as to avoid the long term water pollution by these pesticides.  相似文献   

Delineation of groundwater potential zones and electrical resistivity studies for groundwater exploration   总被引：1，自引：0，他引：1  

Sree P. Devi  S. Srinivasulu  Kesava K. Raju 《Environmental Geology》2001,40(10):1252-1264

The electrical resistivity method is widely used in groundwater exploration studies. The method is particularly well suited to carry out groundwater studies in hard-rock terrains. The popular Schlumberger method of electrode configuration was applied in the study area. In all, 112 vertical electrical soundings (VESs) were carried out at different locations in the study area. VES interpretations were used to generate a top-layer contour map and a depth-to-basement map. Finally, a groundwater quality/potential map for the study area was generated using the depth-to-bedrock map, a water-level fluctuation map, and the second-layer thickness. Furthermore, this groundwater potential map was classified into three sectors, i.e. poor, moderate and good zones with respect to the prospects of finding groundwater in the study area. This map has a practical value, as it provides guidance to farmers in selecting favourable well sites, thereby avoiding unnecessary financial losses.  相似文献   

Quasi-static deformation of a poroelastic half-space with anisotropic permeability by two-dimensional surface loads     

Sarva Jit Singh  Sunita Rani  Raman Kumar 《Geophysical Journal International》2007,170(3):1311-1327

An analytical solution is obtained of the fully coupled diffusion–deformation system of equations governing the quasi-static plane strain deformation of a poroelastic half-space with anisotropic permeability and compressible constituents. The stresses and the pore pressure are taken as the basic state variables. Displacements are obtained by integrating the coupled constitutive relations. The problem of surface loads is discussed in detail. Explicit analytical solutions are derived for normal line loading, shear line loading and normal strip loading. The permeability anisotropy is found to have a significant effect on the quasi-static deformation of the half-space. However, in the drained and undrained limits, the anisotropy has no effect. The stresses in the drained and undrained states are independent of the poroelastic parameters. Numerical computation of the pore pressure indicates that ignoring permeability anisotropy may lead to an overestimation of the pore pressure at points vertically below the point of normal loading. Further, anisotropy in permeability may lead to a dilution in the theoretical prediction of the Mandel–Cryer Effect.  相似文献   

Modelling of 2016 Kumamoto earthquake by integrating site effect in semi-empirical technique     

Devi  Sonia  Sandeep  Kumar  Parveen  Monika  Joshi  A. 《Natural Hazards》2022,111(2):1931-1950

Natural Hazards - The 2016 Kumamoto earthquake (MJMA7.3) struck central area of Kyushu Island, Japan. The presence of near surface low velocity layer greatly amplified the ground motions and caused...  相似文献   

Assessing coastal landscape vulnerability using geospatial techniques along Vizianagaram–Srikakulam coast of Andhra Pradesh,India     

Meenu Rani  Sufia Rehman  Haroon Sajjad  B. S. Chaudhary  Jyoti Sharma  Sandeep Bhardwaj  Pavan Kumar 《Natural Hazards》2018,94(2):711-725

Vizianagaram–Srikakulam coastal shoreline consisting of beaches, mangrove swamps, tidal channel and mudflats is one of the vulnerable coasts in Andhra Pradesh, India. Five site-specific parameters, namely rate of geomorphology, coastal elevation, coastal slope, shoreline change and mean significant wave height, were chosen for constructing coastal vulnerability index and assessing coastal landscape vulnerability. The findings revealed a shift of 2.5 km in shoreline towards the land surface because of constant erosion and that of 1.82 km towards the sea due to accretion during 1997–2017. The rate of high erosion was found in zones IV and V, and high accretion was found in zones II and III. Coastal vulnerability index analysis revealed constant erosion along shoreline and sea level rise in the study area. Most of the coast in zone V has recorded very high vulnerability due to erosion, high slope, significant wave height and sea level rise. Erosion and accretion, significant wave height, sea level rise and slope are attributed to high vulnerability in zones III and IV. Zone II recorded moderate vulnerability. Relatively lower slope, mean sea wave height and sea level rise have made this zone moderately vulnerable. Very low vulnerability was found in zone I, and low vulnerability was recorded in zone II. Accretion, low slope and low sea level rise were found to be causative factors of lower vulnerability. Thus, zones III, IV and V should be accorded higher priorities for coastal management. The findings can be helpful in coastal land planning and management and preparing emergency plans of the coastal ecosystems.  相似文献   

Coastal vulnerability assessment studies over India: a review   总被引：2，自引：2，他引：0  

N. N. V. Sudha Rani  A. N. V. Satyanarayana  Prasad Kumar Bhaskaran 《Natural Hazards》2015,77(1):405-428

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Dynamical instability of cylindrical symmetric collapsing star in generalized teleparallel gravity     

Abdul Jawad  Davood Momeni  Shamaila Rani  Ratbay Myrzakulov 《Astrophysics and Space Science》2016,361(4):141

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Cosmological solution in Brans-Dicke theory involving particle creation     

R. K. Tarachand Singh  A. Ratnaprabha Devi 《Astrophysics and Space Science》1989,155(2):233-240

By considering the Robertson-Walker line element exact cosmological solutions have been obtained by taking spin-half-generated particles as matter sources in the Jordan-Brans-Dicke theory. There exist exact solutions for which the gravitational constant decreases linearly with time and the mass of the Universe increases proportionally to the square of its age while the density decreases with time. The results have been studied corresponding to the three values of curvature index. It has been shown that the expansion law is determined by the particles created by the expansion itself.  相似文献