Hydrogeochemical investigation and groundwater quality assessment of Pratapgarh district,Uttar Pradesh   总被引：3，自引：0，他引：3  

Ashwani Kumar Tiwari  Abhay Kumar Singh 《Journal of the Geological Society of India》2014,83(3):329-343

Hydogrochemical investigation of groundwater resources of Paragraph district has been carried out to assess the solute acquisition processes and water quality for domestic and irrigation uses. Fifty-five groundwater samples were collected and analyzed for pH, electrical conductivity, total dissolved solids, hardness, major anions (F^?, Cl^?, NO₃, HCO₃ ^?, SO₄ ^2?) and cations (Ca²⁺, Mg²⁺, Na⁺, K⁺). Study results reveal that groundwater of the area is alkaline in nature and HCO₃ ^?, Cl^?, Mg²⁺, Na⁺ and Ca²⁺ are the major contributing ions to the dissolved solids. The hydrogeochemical data suggest that weathering of rock forming minerals along with secondary contributions from agricultural and anthropogenic sources are mainly controlling the groundwater composition of Pratapgarh district. Alkaline earth metals (Ca²⁺+Mg²⁺) exceed alkalis (Na⁺+K⁺) and weak acid (HCO₃ ^?) dominate over strong acids (Cl^?+SO₄ ^2?) in majority of the groundwater samples. Ca-Mg-HCO₃ and Ca-Mg-Cl-HCO₃ are the dominant hydrogeochemical facies in the groundwater of the area. The computed saturation indices demonstrate oversaturated condition with respect to dolomite and calcite and undersaturated with gypsum and fluorite. A comparison of groundwater quality parameters in relation to specified limits for drinking water shows that concentrations of TDS, F^?, NO₃ ^? and total hardness exceed the desirable limits in many water samples. Quality assessment for irrigation uses reveal that the groundwater is good for irrigation. However, values of salinity, sodium adsorption ratio (SAR), residual sodium carbonate (RSC), %Na and Kelley index are exceeding the prescribed limit at some sites, demanding adequate drainage and water management plan for the area.  相似文献   

Modeling of strong motion generation areas of the 2011 Tohoku,Japan earthquake using modified semi-empirical technique     

A. Joshi  Sandeep  Kamal 《Natural Hazards》2014,71(1):587-609

Modification in the semi-empirical technique for the simulation of strong ground motion has been introduced to incorporate the strong motion generation areas (SMGA) in the modeled rupture plane. Strong motion generation areas identified within the rupture plane of the Tohoku earthquake of March 11, 2011 (M _w = 9.0), have been modeled using this modified technique. Two different source models having four and five SMGAs, respectively, are considered for modeling purpose. Strong motion records using modified semi-empirical technique have been simulated at two near-field stations located at epicentral distance of 137 and 140 km, respectively, using two different source models. Comparison of the observed and simulated acceleration waveforms is made in terms of root mean square error (RMSE) at both stations. Minimum root mean square error of the waveform comparison has been obtained at both the stations for source model having five SMGAs. Simulations from same rupture model have been made at other four stations lying at epicentral distance between 154 and 249 km. Comparison of observed and simulated records has been made in terms of RMSE in acceleration records, velocity records and response spectra at each six station. Simulations have been made at six other stations to obtain distribution of peak ground acceleration and peak ground velocity with hypocentral distance. Peak ground acceleration and velocity from simulated and observed records are compared at twelve stations surrounding the source of Tohoku earthquake. Comparison of waveforms and parameters extracted from observed and simulated strong motion records confirms the efficacy of the developed modified technique to model earthquake characterized by SMGAs.  相似文献   

Influence of Relative Density on Static Soil–Structure Frictional Resistance of Dry and Saturated Sand     

Binod Tiwari  Ahmed Raad Al-Adhadh 《Geotechnical and Geological Engineering》2014,32(2):411-427

Soil–structure frictional resistance is required while designing foundation systems and retaining walls. Although much more attention has been paid in recent years regarding soil–structure interaction for dynamic loading, highly conservative values of the static frictional resistance between soil and structure are used in design. Not much emphasis has been given lately to evaluate static frictional resistance between soil and structure. In this study, a well graded sand, as per USCS classification system, was prepared in the laboratory at different relative densities and moisture contents i.e. dry and saturated, and frictional resistances of those soils were measured. Those soil samples were also sheared against wood, concrete, and steel blocks and corresponding soil–structure frictional resistances were measured. Moreover, similar experiments were performed for saturated and loose poorly graded sand (SP), silty sand (SM) and poorly graded sand with silt (SP–SM). The study result shows that the difference between frictional resistance of soil and skin friction depends on the type of soil, relative density and the moisture content. Interestingly, shear envelopes for soil–soil and soil–structure shearing resistance exhibited curvature. The traditionally adopted soil–structure frictional resistance values adopted by various geotechnical manuals were found to be highly conservative.  相似文献   

A class of axially-symmetric electromagnetic mass models     

Saibal Ray  Dipankar Ray  R. N. Tiwari 《Astrophysics and Space Science》1993,199(2):333-337

This paper presents a set of solutions of coupled Einstein-Maxwell equations with matter for the Levi-Civita's metric which can be interpreted as electromagnetic mass models which are extensions of the electromagnetic mass models obtained previously. It may be pointed out that electromagnetic mass models are solutions of coupled Einstein-Maxwell equations with matter where all the characteristics of matter vanish when the charge vanishes. Existence of such solution tends to confirm Lorentz's conjecture that the mass of an electron may be of purely electromagnetic origin.  相似文献   

Shock wave propagation in non-ideal fluids     

S. N. Ojha  M. S. Tiwari 《Earth, Moon, and Planets》1993,62(3):273-287

Expressions for the variation of shock strength and its propagation in non-ideal fluids are presented by using the method developed by Whitham. The effects of the presence of rotation, rotation and magnetic field on the strength and propagation velocity of shock waves have been discussed separately. Finally, the effects of the presence of gravitation on the shock strength and on propagation velocity have been studied.  相似文献   

3D SEM Approach to Evaluate the Stability of Large-Scale Landslides in Nepal Himalaya   总被引：3，自引：0，他引：3  

Ram Chandra Tiwari  Netra Prakash Bhandary  Ryuichi Yatabe 《Geotechnical and Geological Engineering》2015,33(4):773-793

  相似文献   

Is tidal forcing critical to trigger large Sumatra earthquakes?     

R. K. Tiwari  Ashutosh Chamoli 《Natural Hazards》2015,77(1):65-74

Complexity in the earthquake mechanism is manifested in different forms such as fractal distribution, clustering of seismicity, etc., and characterized as critical phenomenon. Occurrences of earthquakes generally represent the state of metastable equilibrium. The Andaman–Sumatra subduction zone is one of the most seismically active corridors (possibly in metastable state) in the world. Recently, the region faced three major earthquakes of magnitude more than 8.5 (M ~ 9.1 on December 26, 2004; M ~ 8.6 on March 28, 2005; M ~ 8.6 on April 11, 2012). Researchers have suggested multiple causes of earthquake generation in this region including the one with possible correlation of tidal stresses with earthquake occurrences. The latter issue, however, has been hotly debated in view of the fact that a small stress generated due to tidal forcing cannot cause such a bigger magnitude earthquake. We study here the impact of tidal forcing on critically generated earthquake phenomena. We examined the statistical behavior of recurrence time interval of earthquakes using the available data for period of about 40 years from 1973 to 2013. We constrain the simple empirical toy model using the concept of catastrophe theory to evaluate the impact of small tidal forcing on the critical state of earthquakes occurrences. In addition to the major role of Helmholtz free energy during the plate motion, our analysis suggests that the stability and critical behavior of the earthquake in Sumatra region could be associated with tidal forcing, however, only for triggering of some of the “Catastrophic–Chaotic” earthquake phenomenon.  相似文献   

Study of gradient effects on inertial Alfvén waves in plasma sheet boundary layer region—kinetic approach     

P. Agarwal  P. Varma  M. S. Tiwari 《Astrophysics and Space Science》2014,349(1):223-228

Inertial Alfvén waves are investigated using Maxwell-Boltzmann-Vlasov equation to evaluate the dispersion relation and growth/damping rate in inhomogeneous plasma. Expressions for the dispersion relation and growth/damping rate are evaluated in inhomogeneous plasma. The effects of density, temperature and velocity gradient are included in the analysis. The results are interpreted for the space plasma parameters appropriate to the plasma sheet boundary layer. It is found that the inhomogeneities of plasma contribute significantly to enhance the growth rate of inertial Alfvén wave. The applicability of this model is assumed for auroral acceleration region and plasma sheet boundary layer.  相似文献   

Geoelectrical and Hydrogeochemical Studies for Delineating Ground-Water Contamination Due to Salt-Water Intrusion in the Northern Part of the Nile Delta, Egypt   总被引：3，自引：0，他引：3  

Abdel-Azim M. Ebraheem  Mahmoud M. Senosy  Kamal A. Dahab 《Ground water》1997,35(2):216-222

  相似文献   

Detailed isophotometry of some galaxies,I     

A. I. Gamal el Din  I. A. Issa  A. M. I. Osman  F. Y. Kamal 《Astrophysics and Space Science》1992,190(1):67-88

Results from a detailed isophotometric survey of NGC 5595, NGC 5597, NGC 5605, and NGC 7769 are given. It includes isophotic maps, luminosity profiles and ellipticity curves as well. Scanning of these galaxies was done in theB andV colours.  相似文献