21<Superscript>st</Superscript>AnnualV. M. Goldschmidt Conference,Prague, Czech Republic     

Sisir K. Mondal 《Journal of the Geological Society of India》2012,79(1):111-112

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Identification of active seismicity by fractal analysis for understanding the recent geodynamics of Central Himalaya     

P. N. S. Roy  S. K. Mondal 《Journal of the Geological Society of India》2012,79(4):353-360

Seismicity along the Himalayan front is mostly attributed to the processes of collision between the Indian and the Eurasian plates resulting in the under-thrusting of the Indian Peninsula underneath the Himalaya. The dynamics of the region bears very complex components which require in-depth understanding. Here the overall rate of crustal shortening since ∼ 11 Ma is ∼ 21mm/yr, which is comparable to modern rate of under-thrusting of the northern Indian plate beneath the Himalaya. The region experienced a large number of great earthquakes for the last 100–120 years causing massive destruction. Here an attempt has been made to understand the seismicity pattern of the region using fractal correlation dimension and hence used for the detection of active seismicity. Some clusters of seismicity were found to be indicative of seismically very active zones. Such clusters may enlighten the understanding of recent complex dynamics of Himalayan zone.  相似文献   

Rain height in relation to 0°C isotherm height for satellite communication over the Indian Subcontinent   总被引：1，自引：0，他引：1  

N. C. Mondal  S. K. Sarkar 《Theoretical and Applied Climatology》2003,76(1-2):89-104

Summary ¶The 0°C isotherm height, a parameter needed for the estimation of attenuation of microwave and millimetre wave for earth-space communication, has been estimated for different stations spread over India. The variations of 0°C isotherm height for different seasons over these stations are presented. Attenuations of radio wave due to rain at frequencies 10GHz and above have also been estimated for few stations using the 0°C isotherm height so derived. The results are useful for radio systems designers.  相似文献   

Use of hydrochemical parameters for the identification of fresh groundwater resources,Potharlanka Island,India   总被引：2，自引：0，他引：2  

V.?K.?SaxenaEmail author  V.?S.?Singh  N.?C.?Mondal  S.?C.?Jain 《Environmental Geology》2003,44(5):516-521

A hydrochemical study has been carried out on the fresh groundwater resources of Potharlanka, Krishna Delta, India. Groundwater samples were collected at 58 sites and analyzed in June and December 2001. The groundwater is mildly alkaline with a pH of 7.2–8.2, electrical conductivity (EC) varies from 645–4,700 µS/cm in June 2001 (pre-monsoon) and from 605–5,770 µS/cm in December 2001 (post-monsoon). More than 75% of the samples have >1000 mg/l TDS which is higher than the maximum permissible limit for potable water. Na and Cl are the dominating cations and these are directly proportional to TDS. Extremely low HCO ₃/Cl and variable high Mg/Ca (molar ratios) indicated the transformation of the fresh groundwater aquifer systems to saline. Groundwater of this island is classified as Na–Cl, Na–Ca–Cl–HCO ₃, Na–Mg–Cl–SO ₄ and mixed types. A high percentage of mixed water types indicates the possibility of simultaneous fresh groundwater dilution activity along with a seawater ingression/intrusion process. Low rainfall and excessive withdrawal of groundwater has caused the increase of saline water intrusion.  相似文献   

Birkhoff’S Theorem In The Einstein–Cartan–Kalb–Ramond Theory Of Gravity     

F.?RahamanEmail author  R.?Mukherji  R.?Mondal 《Astrophysics and Space Science》2005,299(3):239-243

It is shown that an analog of Birkhoff’s theorem of general relativity exists in the Einstein–Cartan–Kalb–Ramond (ECKR) theory of gravity when Kalb–Ramond (KR) field strength, which occurs in the theory is independent of time.  相似文献   

Some rain rate and rain attenuation statistics at millimeter wavelengths in the tropics     

N. C. Mondal  A. B. Bhattacharya  S. K. Sarkar  R. Bhattacharya  A. K. Sen 《Theoretical and Applied Climatology》1996,54(3-4):229-234

Summary A study of rain rate and rain induced attenuation characteristics over two tropical stations in India has been made. The observed rain rate distributions differ significantly when compared with the CCIR report. The refractive indices have been calculated for certain frequencies at a tropical rain temperature of 20°C showing the variational pattern at different millimeter wavelengths. The present analysis also reveals that in the range 0.05 cm–0.3 cm drop diameter the variations of scattering amplitudes are systematic while in the range 0.4 cm–0.6 cm they are irregular.With 6 Figures  相似文献   

A comparison of two techniques for calculating groundwater arsenic-related lung,bladder and liver cancer disease burden using data from Chakdha block,West Bengal     

Debapriya Mondal  George C.D. Adamson  Ross Nickson  David A. Polya 《Applied Geochemistry》2008

Calculation of excess disease burden for As exposed populations is becoming increasingly important to enable quantitative estimation of the impacts of various As mitigation options. There are several methods by which such calculations may be carried out. In this study, two methods, recently applied to estimating groundwater As-related health risks in southern Asia, to estimate disease burden arising from lung, bladder and liver cancer from As exposure for an As-effected area of West Bengal have been compared. Both utilized calculated distributions of exposure of the studied population to As from groundwater. Method (I) then entailed calculating disease burden by combining published background rates for death and disability adjusted life years (DALYs) and standard mortality ratios (SMRs) for excess health impacts related to As exposure, whilst for Method (II), disease burden from As exposure was estimated using the basic DALY formula, combined with incidence rates based on the NRC multistage Weibull model. Dose–response data for both methods were based on studies in Taiwan.  相似文献   

Major ion chemistry,weathering processes and water quality assessment in upper catchment of Damodar River basin,India   总被引：5，自引：0，他引：5  

Abhay Kumar Singh  G. C. Mondal  Suresh Kumar  T. B. Singh  B. K. Tewary  A. Sinha 《Environmental Geology》2008,54(4):745-758

The chemical characteristics of surface, groundwater and mine water of the upper catchment of the Damodar River basin were studied to evaluate the major ion chemistry, geochemical processes controlling water composition and suitability of water for domestic, industrial and irrigation uses. Water samples from ponds, lakes, rivers, reservoirs and groundwater were collected and analysed for pH, EC, TDS, F, Cl, HCO₃, SO₄, NO_3, Ca, Mg, Na and K. In general, Ca, Na, Mg, HCO₃ and Cl dominate, except in samples from mining areas which have higher concentration of SO₄. Water chemistry of the area reflects continental weathering, aided by mining and other anthropogenic impacts. Limiting groundwater use for domestic purposes are contents of TDS, F, Cl, SO₄, NO₃ and TH that exceed the desirable limits in water collected from mining and urban areas. The calculated values of SAR, RSC and %Na indicate good to permissible use of water for irrigation. High salinity, %Na, Mg-hazard and RSC values at some sites limit use for agricultural purposes.  相似文献   

A diagnosis of groundwater quality from a semiarid region in Rajasthan,India     

N. C. Mondal  K. K. Tiwari  K. C. Sharma  S. Ahmed 《Arabian Journal of Geosciences》2016,9(12):602

A diagnosis of the groundwater quality of 70 wells sampled during two climatic regimes (dry and raining seasons) from a semiarid area in Rajasthan, India, had been carried out using standard methods. Analysis of the results for various hydrochemical parameters wherein the geological units are alluvium, quartzite and granite gneisses showed that all the parameters did not fall within the World Health Organisation’s acceptable limits for irrigation and drinking water purposes. The order of major cations and anions obtained during the dry and raining seasons are Na⁺ ? Mg²⁺ ? Ca²⁺ ? K⁺ and Cl^?? HCO₃ ^? ? SO₄ ^2?? CO₃ ^?> F^? ? NO₃ ^?, respectively. A maximum value of nitrate of 491.6 mg/l has been examined and its contamination is due to discriminated highly impacted groundwater samples by agricultural activity and small-scale urbanization. Fluoride (F^?) concentration is 6.50 mg/l as a maximum value, whereas values in about 26 % of the samples are more than the permissible limit (1.5 mg/l) for drinking water. The cumulative probability distributions of the selected ions show two individual intersection points with three diverse segments, considered as regional threshold values and highly impacted threshold values for differentiating the samples with the effects of geogenic, anthropogenic and saline water mixing. The first threshold values indicate the background hydrochemical constituents in the study area. The second threshold value of 732 mg/l for bicarbonate indicates that sandy aquifer is being dissolved during wet period, whereas NO₃ ^? concentration of more than the initial threshold value (=75 mg/l) indicates discriminated highly impacted groundwater samples by agricultural activity and urbanization in dry season. Various parameters such as soluble sodium percentage (SSP), salinity (electrical conductivity (EC)), sodium adsorption ratio (SAR), residual sodium carbonate (RSC), Kelley’s ratio (KR), permeability index (PI), residual sodium bicarbonate (RSB) and magnesium absorption ratio (MAR) for the well samples show that, overall, 46 % of groundwater samples are not suitable for irrigation. Further, chloro-alkaline indices (CAIs) were used for distinguishing regional recharge and discharge zones whereas corrosivity ratio (CR) utilized for demarcating areas to use metallic pipes for groundwater supply. In general, groundwater quality is mainly controlled by the chemical weathering of rock-forming minerals. The information obtained represents a base for future work that will help to assess the groundwater condition for periodical monitoring and managing the groundwater from further degradation.  相似文献   

Spatio-temporal variability of lightning climatology and its association with thunderstorm indices over India     

Mondal  Unashish  Panda  S. K.  Das  Someshwar  Sharma  Devesh 《Theoretical and Applied Climatology》2022,149(1-2):273-289

Theoretical and Applied Climatology - Lightning is an electrical discharge — a ‘spark’ or ‘flash’ as charged regions in the atmosphere instantly balance themselves...  相似文献