Evaluation of groundwater quality with emphasis on fluoride concentration in Nalbari district,Assam, Northeast India     

Pallavi Sharma  Hari Prasad Sarma  Chandan Mahanta 《Environmental Earth Sciences》2012,65(7):2147-2159

This study was carried out to analyze groundwater quality in selected villages of Nalbari district, Assam, India, where groundwater is the main source of drinking water. 40 groundwater samples collected from hand pumps and analyzed for pH, EC, TDS, Ca²⁺, Mg²⁺, Na⁺, K⁺, HCO₃ ⁻, SO₄ ²⁻, Cl⁻ and F⁻. Chemical analysis of the groundwater showed that mean concentration of cations in (mg/L) is in the order Ca²⁺ > Mg²⁺ > Na⁺ > K⁺ while for anions it is HCO₃ ⁻ > Cl⁻ > SO₄ ²⁻ > F⁻. Fluoride concentration was recorded in the range of 0.02–1.56 mg/L. As per the desirable and maximum permissible limits for fluoride in drinking water recommended by WHO and by Bureau of Indian Standards (BIS), which is 1.5 mg/L, the groundwater of about 97% of the samples were found to be suitable for drinking purpose. The suitability of the groundwater for irrigation purpose was investigated by some determining factors such as sodium adsorption ratio, soluble sodium percentage, Kelly’s ratio and electrical conductivity. The value of the sodium absorption ratio and electrical conductivity of the groundwater samples were plotted in the US Salinity laboratory diagram for irrigation water. Most of the groundwater samples fall in the field of C2S1 and C3S1 indicating medium to high salinity and low sodium water, which can be used for irrigation on almost all types of soil with little doubt of exchangeable sodium. The hydrochemical facies shows that the groundwater is Ca-HCO₃ type.  相似文献   

The Pavagadh Hill, A Unique Outcrop of the Deccan Trap, Gujarat, India     

K.R. Hari  K. Furuyama  K.P. Shabeer 《Gondwana Research》1999,2(4):676-679

  相似文献   

Interaction of coeval felsic and mafic magmas from the Kanker granite,Pithora region,Bastar Craton,Central India     

R Elangovan  Kumar Krishna  Neeraj Vishwakarma  K R Hari  M Ram Mohan 《Journal of Earth System Science》2017,126(7):92

Field and petrographic studies are carried out to characterize the interactions of mafic and felsic magmas from Pithora region of the northeastern part of the Bastar Craton. The MMEs, syn-plutonic mafic dykes, cuspate contacts, magmatic flow textures, mingling and hybridization suggest the coeval emplacement of end member magmas. Petrographic evidences such as disequilibrium assemblages, resorption textures, quartz ocelli, rapakivi and poikilitic textures suggest magma mingling and mixing phenomena. Such features of mingling and mixing of the felsic and mafic magma manifest the magma chamber processes. Introduction of mafic magmas into the felsic magmas before initiation of crystallization of the latter, results in hybrid magmas under the influence of thermal and chemical exchange. The mechanical exchange occurs between the coexisting magmas due to viscosity contrast, if the mafic magma enters slightly later into the magma chamber, then the felsic magma starts to crystallize. Blobs of mafic magma form as MMEs in the felsic magma and they scatter throughout the pluton due to convection. At a later stage, if mafic magma enters the system after partial crystallization of felsic phase, mechanical interaction between the magmas leads to the formation of fragmented dyke or syn-plutonic mafic dyke. All these features are well-documented in the study area. Field and petrographic evidences suggest that the textural variations from Pithora region of Bastar Craton are the outcome of magma mingling, mixing and hybridization processes.  相似文献   

Analysis of solar radiation pressure induced coupled liberations of a gravity stabilized axisymmetric satellite     

S. K. Shrivastava  Hari B. Hablani 《Celestial Mechanics and Dynamical Astronomy》1979,20(3):297-313

A planar, fixed-orbit model of the rotation of the planet Mercury is analyzed. The model includes only the solar torques on the planet's permanent asymmetry and its solar tidal bulge. For this model, it is shown that the zero of the averaged tidal torque corresponds to an asymptotically stable periodic solution of the second kind which, for two tidal torque representations, is close to the asymptotically stable equilibrium point corresponding to an exact 32 spin-orbit resonance. A conjecture that the current rotation state of Mercury is due to transfer from capture by the zero of the averaged tidal torque to 32 resonance capture with changes in the eccentricity of the planet's orbit is discussed briefly.  相似文献   

Radio and X-ray burst from PSR 0950+08     

M. R. Deshpande  Hari Om Vats  Harish Chandra  P. Janardhan  A. D. Bobra  G. D. Vyas 《Astrophysics and Space Science》1994,218(2):249-265

This article describes in detail a burst from PSR 0950+08 on July 29, 1992. This event was observed by two radio telescopes (separated by ~ 200 km) operating at 103 MHz. There exists a very convincing indirect evidence that at the same time the pulsar also emitted large X-ray flux. The X-ray flux during the event compares with that during a solar X-ray flare. During the event the Sun was extraordinarily quiet as the solar X-ray flux 3 · 10^–7 W/m² only was observed. The cause for the burst is quite unknown and may be complex. However, a possibility of accretion of a comet-like object by pulsar may provide reasonable explanation of the observations. These results open some interesting questions about the pulsar physics.  相似文献   

Erratum to: Seasonal discharge and chemical flux variations of rivers flowing into the Bayhead canal of Durban Harbour,South Africa     

Kavandren Moodley  Srinivasan Pillay  Keshia Pather  Hari Ballabh 《中国地球化学学报》2016,35(4):354-354

  相似文献   

Policy without politics: technocratic control of climate change adaptation policy making in Nepal     

Hemant R. Ojha  Sharad Ghimire  Adam Pain  Andrea Nightingale  Dil B. Khatri  Hari Dhungana 《Climate Policy》2016,16(4):415-433

As developing countries around the world formulate policies to address climate change, concerns remain as to whether the voices of those most exposed to climate risk are represented in those policies. Developing countries face significant challenges for contextualizing global-scale scientific research into national political dynamics and downscaling global frameworks to sub-national levels, where the most affected are presumed to live. This article critiques the ways in which the politics of representation and climate science are framed and pursued in the process of climate policy development, and contributes to an understanding of the relative effectiveness of globally framed, generic policy mechanisms in vulnerable and politically volatile contexts. Based on this analysis, it also outlines opportunities for the possibility of improving climate policy processes to contest technocratic framing and generic international adaptation solutions.

Policy relevance

Nepal's position as one of the countries most at risk from climate change in the Himalayas has spurred significant international support to craft climate policy responses over the past few years. Focusing on the National Adaptation Programme of Action (NAPA) and the Climate Change Policy, this article examines the extent to which internationally and scientifically framed climate policy in Nepal recognizes the unfolding political mobilizations around the demand for a representative state and equitable adaptation to climate risks. This is particularly important in Nepal, where political unrest in the post-conflict transition after the end of the civil war in 2006 has focused around struggles over representation for those historically on the political margins. Arguing that vulnerability to climate risk is produced in conjunction with social and political conditions, and that not everyone in the same locality is equally vulnerable, we demonstrate the multi-faceted nature of the politics of representation for climate policy making in Nepal. However, so far, this policy making has primarily been shaped through a technocratic framing that avoids political contestations and downplays the demand for inclusive and deliberative processes. Based on this analysis, we identify the need for a flexible, contextually grounded, and multi-scalar approach to political representation while also emphasizing the need for downscaling climate science that can inform policy development and implementation to achieve fair and effective adaptation to climate change.  相似文献   

Estimation of structural vulnerability for flooding using geospatial tools in the rural area of Orissa,India     

Praveen K. Thakur  Sreyasi Maiti  Nanette C. Kingma  V. Hari Prasad  S. P. Aggarwal  Ashutosh Bhardwaj 《Natural Hazards》2012,61(2):501-520

Vulnerability assessment of natural disasters is a crucial input for risk assessment and management. In the light of increasing frequency of disasters, societies must become more disaster resilient. This research tries to contribute to this aim. For risk assessment, insight is needed into the hazard, the elements at risk and their vulnerabilities. This study focused on the estimation of structural vulnerability due to flood for a number of structural elements at risk in the rural area of Orissa, India (Kendrapara), using a community-based approach together with geospatial analysis tools. Sixty-three households were interviewed about the 2003 floods in 11 villages and 166 elements at risk (buildings) were identified. Two main structural types were identified in the study area, and their vulnerability curves were made by plotting the relationships between flood depth and vulnerability for each structural type. The vulnerability ranges from 0 (no damage) to 1 (collapse/total damage). Structural type-1 is characterized by mud wall/floor material and a roof of paddy straw, and structural type-2 is characterized by reinforced cement concrete (RCC) walls/floor and a RCC roof. The results indicate that structural type-1 is most vulnerable for flooding. Besides flood depth, flood duration is also of major importance. Houses from structural type-1 were totally collapsed after 3 days of inundation. Damage of the houses of structural type-2 began after 10 days of inundation.  相似文献   

Microwave bursts from Jupiter due to K, N, P2 and S fragments     

Hari Om Vats  M. R. Deshpansde  O. P. N. Calla  N. M. Vadher  B. M. Darji  V. Sukumaran 《Earth, Moon, and Planets》1996,73(2):125-132

This article reports the observations of microwave emission from Jupiter during the impact of K, N, P2 and S fragments of the comet Shoemaker-Levy 9. The comparison of microwave bursts intensities produced by these impacts with the impact class and the size of the impactors reveals no correlation. This is in conformity with other observations at microwave frequencies and indicates that the process of burst emission is very complex. The impacts K and N produced three microwave bursts which could possibly be due to further fragmentation of these fragments. The results are discussed in the perspective of synchrotron emission from Jupiter and possible enhancements due to an increase in the radial diffusion coefficient. However, this model does not fully explain the observations.  相似文献   

Processing of Indian Doppler Weather Radar data for mesoscale applications   总被引：1，自引：1，他引：0  

S. K. Roy Bhowmik  Soma Sen Roy  Kuldeep Srivastava  B. Mukhopadhay  S. B. Thampi  Y. K. Reddy  Hari Singh  S. Venkateswarlu  Sourav Adhikary 《Meteorology and Atmospheric Physics》2011,111(3-4):133-147

This paper demonstrates the usefulness of Indian Doppler Weather Radar (DWR) data for nowcasting applications, and assimilation into a mesoscale Numerical Weather Prediction (NWP) model. Warning Decision Support System Integrated Information (WDSS-II) developed by National Severe Storm Laboratory (NSSL) and Advanced Regional Prediction System (ARPS) developed at the Centre for Analysis and Prediction, University of Oklahoma are used for this purpose. The study reveals that the WDSS-II software is capable of detecting and removing anomalous propagation echoes from the Indian DWR data. The software can be used to track storm cells and mesocyclones through successive scans. Radar reflectivity mosaics are created for a land-falling tropical cyclone??Khaimuk of 14 November 2008 over the Bay of Bengal using observations from three DWR stations, namely, Visakhapatnam, Machilipatnam and Chennai. Assimilation of the quality-controlled radar data (DWR, Chennai) of the WDSS-II software in a very high-resolution NWP model (ARPS) has a positive impact for improving mesoscale prediction. This has been demonstrated for a land-falling tropical cyclone Nisha of 27 November 2008 of Tamil Nadu coast. This paper also discusses the optimum scan strategy and networking considerations. This work illustrates an important step of transforming research to operation.  相似文献