Hyderabad, India
Hyderabad, India
Time filter
Source Type

Netti K.,NGRI | Radhika Y.,Gandhi Institute of Technology and Management
2015 IEEE International Conference on Computational Intelligence and Computing Research, ICCIC 2015 | Year: 2015

In Data Mining classification plays prominent role in predicting outcomes. One of the best supervised classification techniques in Data Mining is Naive Bayes Classification. Naive Bayes Classification is good at predicting outcomes and often outperforms other classification techniques. One of the reasons behind the strong performance of Naive Bayes Classification is due to the assumption of conditional Independence among predictors. However, this very strong assumption leads to loss of accuracy. In this paper, the authors are proposing a novel method for improving accuracy in Naive Bayes Classifier. The proposed novel technique used in NBC gave better accuracy even with Conditional Independence. © 2015 IEEE.

Kumar K.V.,Stanford University | Kumar K.V.,SRTM University | Chavan C.,NGRI | Sawant S.,NGRI | And 7 more authors.
Contributions to Mineralogy and Petrology | Year: 2010

Spatial and temporal variations in the geochemistry of an extrusive basaltic section of Deccan traps record progressive changes in mantle melting and crustal filtration and are relevant to understand continental flood basalt (CFB) magmatism. In the present work we have carried out detailed field, petrographic, density and magnetic susceptibility, and geochemical investigations on a small, semi-continuous extrusive section in the eastern Deccan Volcanic Province (DVP) to understand the role of shallow magma chambers in CFB magmatism. Four formations, Ajanta, Chikhli, Buldhana and Karanja crop out in the Gangakhed-Ambajogai area with increasing elevation. Our studies indicate that: (1) the Karanja Formation represents a major magma addition, as indicated by abrupt change in texture, increases in MgO, CaO, Ni, Cr, and Sr, and drastic decreases in Al2O3, Na2O, K2O, Rb, Ba, REE, bulk-rock density and magnetic susceptibility; (2) assimilation fractional crystallization, crystal-laden magmas, and accessory cumulus phases influence the trace element chemistry of Deccan basalts; (3) the predicted cumulate sequence of olivine gabbro-leucogabbro-oxide-apatite gabbro is supported by the observed layered series in a shallow magma chamber within the DVP; (4) the initial magma was saturated with olivine, plagioclase, and augite, and final the pressure of equilibration for the Gangakhed-Ambajogai section basalts is ~2 kbar (~6 km depth); (5) petrophysical parameters act as proxies for magmatic processes; (6) a small layer of oxide-rich basalts may represent the latest erupted pulse in a given magmatic cycle in the DVP; (7) parental basalts to some of the red boles, considered as formation boundaries, might represent small degree partial melts of the mantle; (8) SW Deccan basaltic-types continue into the eastern DVP; and (9) in addition to the magma chamber processes, dynamic melting of the mantle may have controlled DVP geochemistry. The present study underscores the importance of mapping specific stratigraphic intervals in limited areas to understand mantle and magma chamber processes relevant to CFB magmatism. © Springer-Verlag 2009.

Ganai J.A.,AMU | Rashid S.A.,AMU | Alam M.M.,AMU | Balaram V.,NGRI | Sathyanarayanan M.,NGRI
Himalayan Geology | Year: 2014

The Permo-Carboniferous siliciclastic sedimentary sequence from the Tethys Himalaya, Spiti region, Himachal Pradesh has been studied thoroughly for field investigations and geochemistry. The Kanawar and Kuling groups, representing the Permo- Carboniferous sequence in this area, consist primarily of alternate sequence of sandstones and shales with variable thickness. Present study is focused mainly on the fine grained grey to black shales from the Kanawar Group, which is associated with medium to coarse grained sandstones consisting of Lipak, Po and Ganmachidam formations, from bottom to top in chronological order. The concentration of major oxides and their ratios (e.g., Al2O3/TiO2, K2O/ Na2O etc.)suggest unroofing of dominantly felsic components during the deposition of these sediments. The chemical index of alteration (CIA) values (ranging from 54-74) reveals that the source rock of the Spiti sediments had experienced contrasting climatic conditions from warm and humid during Carboniferous to arid to semi-arid during Permian. This study thus not only determines the provenance characteristics of the sediments but also documents a shift in climate during Permo- Carboniferous.

Pauwels H.,Bureau de Recherches Géologiques et Minières | Negrel P.,Bureau de Recherches Géologiques et Minières | Dewandel B.,Indo French Center for Ground Water Research | Dewandel B.,Bureau de Recherches Géologiques et Minières | And 5 more authors.
Journal of Hydrology | Year: 2015

Hydrochemical borehole-loggings with a submersible Idronaut Ocean Seven 302 multiparameter probe equipped of F- and NO3-ion-selective electrodes in combination with EC, pH and dissolved oxygen, were applied for characterizing fluoride (F) contamination in a crystalline (hard-rock) aquifer of a small Indian agricultural watershed where groundwater is intensively abstracted for rice irrigation. A high accuracy of F concentrations determined in-situ-shown by comparing with laboratory analyses-was obtained through using conductivity logs for ionic strength consideration. Large variations in chemical composition and particularly of F-concentration were observed inside boreholes, though restricted to the weathered/fractured layer down to 30-35m depth. This conforms to the hydrogeological model of a crystalline aquifer where most groundwater flow occurs in the shallow part of the fractured zone. The general trend of increasing F content with depth results from F accumulation through water-rock interaction, but the shape of the F profile depends on the connectivity of the fracture network close to the borehole. The concentrations seen within the water-table fluctuation zone locally suggest F input from fertilizers in groundwater, in addition to the earlier-demonstrated role of evaporation from irrigation return flow. It is also likely that, locally, the deepening of boreholes has contributed to increasing the population's vulnerability by tapping F-enriched groundwater at depth. © 2015 Elsevier B.V.

Pettenati M.,Bureau de Recherches Géologiques et Minières | Perrin J.,Bureau de Recherches Géologiques et Minières | Perrin J.,Indo French Center for Ground Water Research | Pauwels H.,Bureau de Recherches Géologiques et Minières | Ahmed S.,NGRI
Applied Geochemistry | Year: 2013

Overexploitation of crystalline aquifers in a semi-arid climate leads to a degradation of water quality, with the main processes responsible for the observed salt loads probably being irrigation return flow (IRF) and a high evaporation rate. The present study has focused on modelling the F- accumulation caused by IRF below rice paddy fields in the small endorheic Maheshwaram watershed (Andhra Pradesh, Southern India). The transient simulation was performed with a 1D reactive transport PHREEQC column and took into account IRF evaporation, kinetically controlled mineral dissolution/precipitation, ion adsorption on Fe hydroxides, and mixing with fresh groundwater. The results revealed the role of cationic exchange capacity (CEC) in Ca/Na exchange and calcite precipitation, both favouring a decrease of the Ca2+ activity that prevents fluorite precipitation. Iron hydroxide precipitation offers a not inconsiderable adsorption capacity for F- immobilization. The principal sources of F- are fluorapatite dissolution and, to a lesser extent, allanite and biotite dissolution. Anthropogenic sources of F-, such as fertilizers, are probably very limited. After simulating an entire dry-season irrigation cycle (120days), the results are in good agreement with the observed overall increase of Cl- in the Maheshwaram groundwater. The model enables one to decipher the processes responsible for water-resource degradation through progressive salinization. It shows that F- enrichment of the groundwater is likely to continue in the future if groundwater overexploitation is not controlled. © 2012 Elsevier Ltd.

Krishnamacharyulu S.K.G.,SRTM University | Rao B.U.M.,C.G.W.B. | Singh V.S.,NGRI
2nd International Conference on Engineering Geophysics | Year: 2013

In coastal regions, particularly in Deltas the fresh groundwater aquifers are under stress due to the improper mining of fresh water. Groundwater studies in the Deltas are difficult mainly due to complexities in their geomorphology. Western Krishna Delta in southern India with densely populated and abundant agricultural fields is one example where the detailed hydrogeological studies are prerequisite for sustainable water management. Most of the earlier hydrogeological studies carried out were only at macro level and considered the entire Delta as one geomorphic unit i.e. alluvium. This study shows that this delta is not occurring as one geomorphic unit and there are different micro-geomorphic units in it. Keeping this in view a detailed study is carried out to identify different micro geomorphic units and groundwater conditions in each of the geomorphic unit. Dividing the Delta into micro units is mandatory in order to understand and address the groundwater problems, as each micro geomorphic unit has major bearing on the occurrence of groundwater and its quality. A comprehensive study is made using geophysics, hydrometerology, hydrogeological and hydrochemistry to understand the salinity conditions in this Delta area and to delineate the fresh water pockets in order to protect the precious groundwater resources.

Reddy P.R.,NGRI
International Journal of Earth Sciences and Engineering | Year: 2012

Earthquake resultant vulnerabilities and hazards can only be addressed through an integrated technological and scientific interventions. Since earthquake resultant energy destabilises the subsurface and surface strata, resulting in damage to building structural stability a realistic interaction, with a holistic approach, between earth scientists and structural engineers can help in better implementation of preventive, curative, mitigation and developmental measures. © 2012 CAFET-INNOVA TECHNICAL SOCIETY.

Vidya Sagar R.,Indian Institute of Science | Prasad R.V.,Indian Institute of Science | Raghu Prasad B.K.,Indian Institute of Science | Rao M.V.M.S.,NGRI
Experimental Mechanics | Year: 2013

This article reports the acoustic emission (AE) study of precursory micro-cracking activity and fracture behaviour of quasi-brittle materials such as concrete and cement mortar. In the present study, notched three-point bend specimens (TPB) were tested under crack mouth opening displacement (CMOD) control at a rate of 0.0004 mm/sec and the accompanying AE were recorded using a 8 channel AE monitoring system. The various AE statistical parameters including AE event rate (dn/dt), AE energy release rate (dE/dt), amplitude distribution for computing the AE based b-value, cumulative energy (ΣE) and ring down count (RDC) were used for the analysis. The results show that the micro-cracks initiated and grew at an early stage in mortar in the pre peak regime. While in the case of concrete, the micro-crack growth occurred during the peak load regime. However, both concrete and mortar showed three distinct stages of micro-cracking activity, namely initiation, stable growth and nucleation prior to the final failure. The AE statistical behavior of each individual stage is dependent on the number and size distribution of micro-cracks. The results obtained in the laboratory are useful to understand the various stages of micro-cracking activity during the fracture process in quasi-brittle materials such as concrete & mortar and extend them for field applications. © 2013 Society for Experimental Mechanics.

Loading NGRI collaborators
Loading NGRI collaborators