Initial results of bio-potential signal (Seismic Electric Signal) related to seismic activities     

Vinod Kushwah  Rudraksh Tiwari  Mulayam S. Gaur  Rajeev K. Tiwari 《Acta Geophysica》2013,61(4):935-949

In recent year, there has been growing interest in the possible use of electromagnetic observations to study earthquakes and possible precursors prior to seismic activity, in response to the success in United States, Japan, Russia, China, and other countries using seismo-electromagnetic methods. We have established a new experimental setup (i.e., biopotential sensor) in Farah region (geographic coordinates: 27.17°N, 77.47°E), Mathura, India. The setup has started operating and analyzed the data since November 2011. The data have been tested by various methods and a good correlation with seismic events was found; thus, a real-time analysis from 21:00 p.m. through 8:00 a.m. every day was initiated. First, we recorded the amplitude enhancement in bio-potential and found positive correlation with seismic activities (near Delhi and Rajasthan) and analyzed the data with solar flares and magnetic storms during the same period, finding a negative correlation of these events. The studies of these events are in progress with statistical analysis of the data. We chose the observing site in Farah region because this region is well known for being a site of a conductive channel of seismic activity.  相似文献   

3D SEM-based seismic ground response analysis of Kathmandu Valley in 2015 Gorkha Nepal earthquake     

Tiwari  R. C.  Bhandary  N. P. 《Journal of Seismology》2021,25(5):1321-1338

Journal of Seismology - The aftershocks of the 2015 Mw7.8 Gorkha Nepal earthquake extend up to 130km to the east of the epicenter. The distribution suggests that the rupture has propagated from...  相似文献   

Revisiting the Koyna-Warna seismic zone: strain budget,present-day potential and associated hazard     

Sutar  Anup K.  Roy  Sukanta  Tiwari  V. M. 《Journal of Seismology》2021,25(5):1265-1279

Journal of Seismology - The Koyna-Warna region in western India is well known around the globe for recurrent reservoir-triggered seismicity soon after the impoundment of the Koyna and Warna...  相似文献   

Some geometric properties of a dusty fluid in MFD flows     

S. N. Singh  H. S. Tiwari  H. P. Singh 《Astrophysics and Space Science》1984,105(2):237-244

By reformulating the basic equations governing the steady, compressible dusty fluid in magneto-fluid flows, certain geometric results of physical importance are obtained. The congruence of the stream lines and magnetic field lines have been taken as the orthogonal coordinate curves on the Maxwellian surfaces.  相似文献   

A bianchi type-III cosmological model in Brans-Dicke theory for vacuum field     

Ramji Tiwari  D. K. Singh 《Astrophysics and Space Science》1984,105(1):67-71

An exact solution of Brans-Dicke (B-D) field equations for the metric tensor of a spatially homogeneous Bianchi type-III configuration has been obtained for vacuum field. It is shown that in the limiting case the solution reduces to that of Einstein field equations in vacuum.  相似文献   

Stabilization of fuel oil contaminated soil—A case study   总被引：1，自引：0，他引：1  

Sanjay J. Shah  A. V. Shroff  Jignesh V. Patel  K. C. Tiwari  D. Ramakrishnan 《Geotechnical and Geological Engineering》2003,21(4):415-427

Fuel oil contamination brings adverse effect on basic geotechnical properties of foundation soil. The present study pertains to one such case, from the petrochemical complex near Vadodara City in Gujarat State, India. Here, the fuel oil contaminated soil samples exhibit drastic changes in their geotechnical parameters. Noteworthy among such deleterious changes are: decrease in maximum dry density (–4%), cohesion (–66%), angle of internal friction (–23%) and unconfined compressive strength (UCS) (–35%) and increase in liquid limit (+11%). An attempt has been made to stabilize the contaminated soil using various additives viz., lime, fly ash and cement independently as well as an admixture of different combinations. It is apparent from the test results that the stabilization agents improved the geo-technical properties of the soil by way of cation exchange, agglomeration, and pozzuolanic actions. The best results were observed when a combination of 10% lime, 5% fly ash and 5% cement was added to the contaminated soil. The improvement in unconfined compressive strength (UCS), cohesion and angle of internal friction can be attributed to neo-formations such as Calcium Silicate Hydrates (CSH, CSH-1) that coats and binds the soil particles. Formation of stable complex between oil and metallic cations, results in reduction of leachableoil.  相似文献   

Hydromorphogeological Mapping for Groundwater Prospecting Using Landsat-MSS Images — A Case Study of Part of Dhanbad District,Bihar     

A Tiwari  B Rai 《Journal of the Indian Society of Remote Sensing》1996,24(4):281-285

The Dhanbad district in Bihar, feces acate water scareity and is chronically drought prone. The groundwater resources in the area have not been fully exploited. The present study was undertaken to evaluate the groundwater prospective zones, Landsat-5 MSS data of band-2 and band-4 and false colour composite of band 2, 3, 4 were interpreted visually to differentiate different hydromarphogeological units and to delineate the major trends of lineaments. The different geomorphic features identified are linear ridges, residual hills, pediplain, buried pedtment and dissected pediplain, besides lineaments. The study shows that the pediplain and buried pediments are promising zones for groundwater prospecting.  相似文献   

Assessment of surface water potential using morphometry and curve number-based approaches     

K. Nidhi  K. N. Tiwari  V. Shinde  V. K. Dadhwal 《国际地球制图》2017,32(11):1206-1228

Geomorphic and curve number-based run-off estimation approaches are proposed in this study for Olidih watershed, India. Cartosat Digital Elevation Model derived morphometry parameters were used for the computation of run-off. The observed and predicted run-off are uniformly scattered around 1:1 line and coefficient of correlation (R²) is found to be around 0.94 in case of NRCS-CN method. Run-off assessment computed using geomorphological parameters and NRCS-CN approach has improved with the introduction of rainfall correction factor. The improved R² from 0.3 to 0.86 in this case was attributed to rainfall correction factor computed based on the long-term rainfall average of the study area. Run-off assessment made using composite parameter approach shows R² values of 0.98 and 0.82 for different initial abstraction losses 0.2 and 0.3, respectively, and has indicated better prediction. Therefore, proposed morphometry-based approaches can be explored as an alternative for simulating the hydrological response of the watersheds.  相似文献   

Processes and factors of metropolitanization in India     

Diwakar A 《Population geography : a journal of the Association of Population Geographers of India》1993,15(1-2):41-46

The author analyzes causes and consequences of urbanization in India. Aspects considered include levels and trends in urbanization, uneven distribution of urban population, concentration of population in large cities, and causes of metropolitanization.  相似文献   

Gravitational sources of purely electromagnetic origin     

R. N. Tiwari  J. R. Rao  Saibal Ray 《Astrophysics and Space Science》1991,178(1):119-132

The Einstein-Maxwell field equations for charged dust corresponding to static axially-symmetric metric of Levi-Civita have been studied. It has been shown that when the metric potentialsg _ij are functions of only one of the coordinates, viz.,r, the interior charged dust becomes purely of electromagnetic origin, in the sense that the physical quantities like the energy density, the effective gravitational mass, etc., are dependent only on the charge density and vanish when this charge density vanishes. Such models are known as electromagnetic mass models in the classical electrodynamics. An interior charged dust solution corresponding to this case has been obtained which, in a sense, represents an infinite dust distribution of electromagnetic origin. In the second case, viz., when the metric potentials are functions of the coordinatesr andz both, it has been shown that some of the situations correspond to electromagnetic mass models. An example to illustrate this case has been obtained. This represents the source of the Reissner-Nordström-Curzon field (an analogue of the Reissner-Nordström solution obtained by Curzon) which according to Curzon describes the exterior field of an electron.  相似文献