Carbon Bead‐Supported Ethylene Diamine‐Functionalized Carbon Nanofibers: An Efficient Adsorbent for Salicylic Acid          下载免费PDF全文

Neetu Talreja  Nishith Verma  Dinesh Kumar 《洁净——土壤、空气、水》2016,44(11):1461-1470

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Geochemical appraisal of mine discharge and tailing at Malanjkhand copper mine,India     

Sk. Md. Equeenuddin  Abhijit Panda  Vishal Singh  Prafulla Kumar Sahoo  Subhashis Sahu  Sumit Kumar Basantray 《Journal of the Geological Society of India》2017,89(2):209-215

Geophysical investigation using Vertical Electrical Sounding (VES), Electrical Resistivity Tomography (ERT) and Seismic Refraction at a proposed conference center site along Ajibode-Labani road, Ibadan, southwestern Nigeria has been carried out. The investigation aims at characterizing and delineating the subsurface strata to understand the weathered profile at the site. Understanding the weathered profile is essential in determining the suitability of the site for engineering construction of the future conference center. A total of 25 VES and 10 ERT profiles were acquired in a systematic grid pattern using both Schlumberger andWenner configurations with Allied omega terrameter. TheVES data were processed and analyzed using WinResist and the ERT data were inverted using RES2DINV. The data were combined to form a 3-D data set of the site and RES3DINV was used to produce the depth slices. Seismic refraction data were also acquired with an ABEM seismograph and processed using SeisImager and Fajseis software. Seismic data were used in understanding the velocity distribution and thickness. The results of VES, ERT and seismic refraction show good correlation. Four sub-surface layers were delineated: top layer of reworked sand, clayey sand/ lateritic hard pan, clay/ sandy clay and fracture/ fresh basement. The 3-D model permits a pictorial view of the sub-surface in relation to materials that overlie the basement. The thickness of unconsolidated materials to bedrock varies from 2.7 m to 12.2 m which revealed inhomogeneity in weathering under the shallow sub-surface. It is found that the integrated geophysical tool is well suited to characterize and delineate sub-surface structure (weathered profile) for engineering site characterization.  相似文献   

Study of mechanical properties of Vindhayan shaly rocks at elevated temperature     

Manish Kumar Jha  A. K. Verma  Pradeep Kumar Gautam  Anil Negi 《Journal of the Geological Society of India》2017,90(3):267-272

Shale is an important rock due to its suitability for different engineering and scientific applications. Elevated temperature may cause major deformation or damage in shale rock and it may be of irreversible in nature. Such damage have adverse effect on the physicomechnical properties of shale rock. The uniaxial compressive strength and tensile strength of two shales (upper Vindhyan basin, India) have been estimated at elevated temperature using point load strength index method. The rock samples have been analyzed at various temperatures starting from room temperature to 900 °C. The effect of elevated temperature on the physicomechanical properties and their influence on the uniaxial compressive strength has been studied in detail. Damage induced, in both shale have been estimated using compressional wave velocity. The analysis of the experimental result shows that the uniaxial compressive strength decreases from 63.45 to 18.45 MPa and 60.94 to 22.22 MPa, for Jhiri and Ganurgarh shale respectively. Tensile strength of shales have been also estimated. The value of tensile strength decreases from 3.65 to 1.05 MPa and 3.46 to 1.26 MPa respectively for Jhiri and Ganurgarh shale. Multivariate regression analysis has been carried out to obtain the correlation between physicomechanical properties and uniaxial compressive strength of Jhiri and Ganurgarh shale.  相似文献   

Ultra-low-frequency (ULF) and total electron content (TEC) anomalies observed at Agra and their association with regional earthquakes     

Vishal Chauhan  O.P. Singh  Vinod Kushwah  Vikram Singh  Birbal Singh 《Journal of Geodynamics》2009,48(2):68-74

Employing a three-component search coil magnetometer (f = 0.01–30 Hz) the ultra-low-frequency (ULF) magnetic field observations have been taken in a noise free rural site at Bichpuri, Agra, India since 20 April 2007. We have analysed 7 months of night time data from 01 May to 30 November 2007. The data show seven occurrences of ULF bursts with periods ranging from a few minutes to an hour in a wide frequency range up to 15 Hz. The occurrence of such ULF bursts has been statistically analysed. The polarization parameter analysis shows that two of these bursts occurred from sources in the ionosphere and magnetosphere (Z/X < 1). It is further seen that four bursts correlated very well with some regional earthquakes (M > 4.5), which occurred at distances less than 628 km from the observation site at Agra. In some cases the bursts occurred 1–3 days prior to the main shocks.Since earthquakes are also known to perturb the ionosphere, we have analysed total electron content (TEC) data obtained from a GPS receiver stationed at Agra since June 2006. Analysis of the data for the same period as the magnetic field observations shows that there existed TEC anomalies on all the days when ULF bursts occurred. The TEC anomalies show enhancement and depletion in the data in all cases. While the mechanisms of the ULF and TEC anomalies are not well known, it is expected that the ULF bursts occurred due to microfracturing of the earth's crust during stress accumulation and that the TEC anomalies occurred as a result of the electric field induced in the ionosphere during such processes.  相似文献   

Aerosol optical properties retrieved using Skyradiometer at Hanle in western Himalayas     

Neeharika Verma  S.P. Bagare  Shantikumar Singh Ningombam  Rajendra B. Singh 《Journal of Atmospheric and Solar》2010,72(1):115-124

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Sustainability assessment of sodic land reclamation using remote sensing and GIS     

M. S. Yadav  P. P. S. Yadav  M. Yaduvanshi  D. Verma  A. N. Singh 《Journal of the Indian Society of Remote Sensing》2010,38(2):269-278

Sodicland reclamation in the Indo-Gangetic plains is being done on a large scale in the states of Uttar Pradesh, Punjab and Haryana in India. However, in certain areas, the reclamation has been reported to be unsustainable and the soils are reverting back to sodicity condition. A study was conducted in one of the reclamation sites of Etawah district for sustainability assessment of sodic land reclamation using remote sensing, Geographic Information system (GIS) and ancillary ground information. Multitemporal satellite data were used for delineation of reclaimed sodiclands and reverted sodic land. Field survey was conducted to find out the various causative factors. Groundwater level information and detailed field survey data were analysed in GIS environment. Results showed that in the reclamation site covering 3,905 ha. in 57 villages of the district, about 27 per cent of reclaimed lands were reverted to sodicity. High water table condition, improper drainage, nearness to canal (within 500 m), and hard pan in the sub-soil were found to be the reasons for unsustainability of reclamation.  相似文献   

The major lightning regions and associated casualties over India     

Yadava  Pramod Kumar  Soni  Manish  Verma  Sunita  Kumar  Harshbardhan  Sharma  Ajay  Payra  Swagata 《Natural Hazards》2020,101(1):217-229

Natural Hazards - Lightning, a climate-related highly localized natural phenomenon, claims lives and damage properties. These losses could only be reduced by the identification of active seasons...  相似文献   

Responses of phytoplankton and its satellite bacteria to exogenous ethanol     

Abate  Rediat  Hetharua  Buce Hanoch  Patil  Vishal  Lin  Daner  Kifle  Demeke  Liang  Junrong  Chen  Changping  Sun  Lin  Kao  Shuh-Ji  Bi  Yonghong  Huang  Bangqin  Gao  Yahui 《中国海洋湖沼学报》2023,41(1):203-214

Journal of Oceanology and Limnology - The response of phytoplankton and its satellite bacteria to various concentrations (0.01%–10% v/v) of ethanol is studied. To elucidate the effect of...  相似文献   

A new scheme of radiation transfer in HII regions including transient heating of grains     

S. K. Ghosh  R. P. Verma 《Journal of Astrophysics and Astronomy》2000,21(1-2):61-76

A new scheme of radiation transfer for understanding the infrared spectra of HII regions, has been developed. This scheme considers non-equilibrium processes (e.g. transient heating of the very small grains, VSG; and the polycyclic aromatic hydrocarbon, PAH) also, in addition to the equilibrium thermal emission from normal dust grains (BG). The spherically symmetric interstellar dust cloud is segmented into a large number of “onion skin” shells in order to implement the non-equilibrium processes. The scheme attempts to fit the observed SED originating from the dust component, by exploring the following parameters: (i) geometrical details of the dust cloud, (ii) PAH size and abundance, (iii) composition of normal grains (BG), (iv) radial distribution of all dust (BG, VSG & PAH). The scheme has been applied to a set of five compact H II regions (IRAS 18116 − 1646, 18162 − 2048, 19442 + 2427, 22308 + 5812, and 18434 - 0242) whose spectra are available with adequate spectral resolution. The best fit models and inferences about the parameters for these sources are presented.  相似文献   

A revisit of NRCS-CN inspired models coupled with RS and GIS for runoff estimation   总被引：3，自引：1，他引：2  

S. Verma  S. K. Mishra  A. Singh  G. K. Jayaraj 《水文科学杂志》2017,62(12):1891-1930

The Natural Resource Conservation Service – Curve Number (NRCS-CN) methodology is a widely used tool for estimating surface runoff, which is of prime importance in hydrological engineering, agricultural planning and management, environmental impact assessment, flood forecasting, and others fields. This article reviews the methodology and associated hydrological models used for runoff estimation along with their advantages and limitations. Furthermore, discussion focuses on the potential applications of Remote Sensing (RS) and Geographical Information System (GIS) techniques for estimating hydrological variables, such as rainfall, soil moisture and CN required for the NRCS-CN methodology, as well as future research and opportunities for improved runoff estimation at the macro scale.