Geochemical characterization of adsorbed light gaseous alkanes in near surface soils of the eastern Ganga basin for hydrocarbon prospecting     

Ch. Srinivas  T. Madhavi  M. Lakshmi  Devleena Mani  M. S. Kalpana  D. J. Patil  A. M. Dayal  S. V. Raju 《Geochemistry International》2014,52(1):68-76

This study aims to assess the hydrocarbon potential of Ganga basin utilizing the near surface geochemical prospecting techniques. It is based on the concept that the light gaseous hydrocarbons from the oil and gas reservoirs reach the surface through micro seepage, gets adsorbed to soil matrix and leave their signatures in soils and sediments, which can be quantified. The study showed an increased occurrence of methane (C₁), ethane (C₂) and propane (C₃) in the soil samples. The concentrations of light gaseous hydrocarbons determined by Gas Chromatograph ranged (in ppb) as follows, C₁: 0–519, C₂: 0–7 and C₃: 0–2. The carbon isotopic (VPDB) values of methane varied between ?52.2 to ?27.1‰, indicating thermogenic origin of the desorbed hydrocarbons. High concentrations of hydrocarbon were found to be characteristic of the Muzaffarpur region and the Gandak depression in the basin, signifying the migration of light hydrocarbon gases from subsurface to the surface and the area’s potential for hydrocarbon resources.  相似文献   

Flood hazard assessment with multiparameter approach derived from coupled 1D and 2D hydrodynamic flow model     

Pankaj Mani  Chandranath Chatterjee  Rakesh Kumar 《Natural Hazards》2014,70(2):1553-1574

Hydrodynamic flow modeling is carried out using a coupled 1D and 2D hydrodynamic flow model in northern India where an industrial plant is proposed. Two flooding scenarios, one considering the flooding source at regional/catchment level and another considering all flooding sources at local level have been simulated. For simulating flooding scenario due to flooding of the upstream catchment, the probable maximum flood (PMF) in the main river is routed and its flooding impact at the plant site is studied, while at the local level flooding, in addition to PMF in the main river, the probable maximum precipitation at the plant site and breaches in the canals near the plant site have been considered. The flood extent, depth, level, duration and maximum flow velocity have been computed. Three parameters namely the flood depth, cross product of flood depth and velocity and flood duration have been used for assessing the flood hazard, and a flood hazard classification scheme has been proposed. Flood hazard assessment for flooding due to upstream catchment and study on local scale facilitates determination of plinth level for the plant site and helps in identifying the flood protection measures.  相似文献   

Biostratigraphy and depositional environment of the Miocene limestone bed of Baripada,Mayurbhanj district,Odisha: Foraminiferal,sedimentological and bulk organic geochemical evidences     

Ajoy K. Bhaumik  Joydeep Paikray  Jagadish Dutta  Arijit Mitra  Devleena Tiwari  Dattatray J. Patil 《Journal of the Geological Society of India》2017,90(4):437-446

Baripada Marine Beds (BMB) have been studied extensively in terms of its mega fossil content. However, not much has been discussed about the foraminiferal content and the organic matter assemblage in these beds. The fossiliferous sequence of BMB consists of sandstone, shale and limestone units. The present study is persued on the limestone unit of BMB. Foraminiferal, thin section and rock-eval pyrolysis studies were performed on the 33 surface samples collected from five sections of Jamdapal and Mukurmatia region along the Budhabalang river bank. Foraminifera are less abundant in the samples of Jamdapal, whereas Mukurmatia is comparatively rich. First appearance datum of Globorotalia menardii[ranges since middle Miocene (12.6 Ma); FAD at planktic foraminiferal zone N12] and last appearance datum of Neogloboquadrina continuosa [ranges between early Miocene (23.2 Ma) to late Miocene (8.3 Ma); FAD at planktic foraminiferal zone N4B and LAD at N16] together suggest that the limestone unit was deposited in between 12.6 to 8.3 Ma within the upper Miocene. Also, the association of shallow water benthic foraminifera (Species of Ammonia, Asterorotalia, Bolivina, Buliminella, Cibicides, Challengerella, Criboelphidium, Cribononion, Elphidium, Hanzawaia, Nonionella) and planktic foraminifera (Globigerina falcoensis, Globigerina woodi, Globorotalia menardii, Neogloboquadrina continuosa) together with oyster bank and shark teeth suggest deposition of limestone within well oxygenated, tropical, shallow water, open marine condition (within 40m water depth). Lithological and thin section studies together with global sea level fluctuation history advocate that upper Miocene marine transgression promoted the formation of this unit. Bulk organic geochemical data obtained by the rock-eval pyrolysis studies on selected samples indicate a low total organic carbon (TOC), with low hydrogen index (HI), high oxygen index (OI). The organic facies is characterised by type-IV kerogen with major contribution from near shore terrestrial plants. This also suggests deposition in shallow, oxygenated environments that did not promote significant accumulation and preservation of organic content in sediments.  相似文献   

Adsorption of Zinc using Tea Factory Waste: Kinetics,Equilibrium and Thermodynamics     

Kailas L. Wasewar  Mohammad Atif  Basheshwar Prasad  Indra Mani Mishra 《洁净——土壤、空气、水》2008,36(3):320-329

In India, the annual production of tea is ca. 857,000 tonnes, which is 27.4% of the total world production. The amount of tea factory waste (TFW) produced per annum after processing is ca. 190,400 tonnes. TFW can be used as a low cost adsorbent for the removal of toxic metals from the aqueous phase. An investigation was carried out to study the feasibility of the use of TFW as an adsorbent for the removal of the heavy metal, zinc. Equilibrium, kinetic and thermodynamic studies were reported. The straight line plot of log (q_e–q) versus time t for the adsorption of zinc shows the validity of the Lagergren equation. The various steps involved in adsorbate transport from the solution to the surface of the adsorbent particles were dealt with by using a Weber‐Morris plot, q_e versus t^0.5 for the TFW. The rate controlling parameters, k_id,1 and k_id,2, were determined and it was found that the macro‐pore diffusion rate was much larger than micro‐pore diffusion rate. A batch sorption model, which assumes the pseudo‐second‐order mechanism, was used to predict the rate constant of sorption, the equilibrium sorption capacity and the initial sorption rate with the effect of initial zinc (II) ion concentration. Equilibrium data obtained from the experiments were analyzed with various isotherms, i. e., Freundlich, Langmuir, Redlich‐Peterson and Tempkin. The adsorption equilibrium was reached in 30 min and the adsorption data fitted well to all models. The maximum adsorption capacity of TFW for zinc (II) ions was determined to be 14.2 mg/g. The capacity of adsorption on Zn(II) increased with increasing temperatures and pH. The maximum uptake level of zinc was observed at pH of 4.2. The various thermodynamic parameters, i. e., ΔG°, ΔH° and ΔS°, were estimated. The thermodynamics of the zinc ion/TFW system indicated a spontaneous, endothermic and random nature of the process. The results showed that the TFW, which has low economical value, is a suitable adsorbent for the removal of zinc (II) ions from aqueous solutions.  相似文献   

An Implicit Scheme for Shallow Water Flow with Wet Dry Interface     

Hriday Mani Kalita  Arup Kumar Sarma 《Water Resources》2018,45(1):61-68

A finite difference implicit scheme is presented in this paper for solution of the shallow water equations in one dimensional (1D) form. The present model has many advantages like, handling of discontinuous and complex bed topography, satisfying C-property (preservation of motionless water surface over a wet or dry bed) and capability of handling large value of temporal step etc. Another very important feature of the present model is that, no special treatment of the source vector of the governing equations is required here to deal with very less water depth. To investigate the performance of the present model in diverse situations, it is used to replicate four different problems of known analytical solution, and the model is found to be quite capable for varied situations.  相似文献   

Glacier surface characteristics derivation and monitoring using Hyperspectral datasets: a case study of Gepang Gath glacier,Western Himalaya     

Akshay Gore  Sneh Mani  HariRam R.P.  Chander Shekhar  Ashwagosha Ganju 《国际地球制图》2019,34(1):23-42

Mountain Glaciers are natural resources of fresh water and these affect the stream flow of the rivers, regional climate and further global climate. Observed trends and projected future evolutions of climate and Cryospheric variables clearly suggest a need to monitor these changes. Accordingly, the article presents the glacier features mapping using Hyperspectral remote sensing imagery. A freely available Hyperion satellite imagery acquired over Gepang Gath glacier in Himachal Pradesh, India is used for the study. Each class is identified based on their surface characteristics of spectral reflectance properties. Identification is simplified by demarcating the study glacier into accumulation and ablation areas through snowline. Accumulation area is characterized with high reflectance clean snow/ice and reduced moderate reflectance Snow/firn. The identification of classes in Hyperion imagery is validated using the spectral library from USGS and ASTER, and field spectra obtained from literature.  相似文献   

Distribution patterns of medicinal plants along an elevational gradient in central Himalaya, Nepal   总被引：1，自引：1，他引：0  

Maan B.ROKAYA  Zuzana MNZBERGOVá  Mani R.SHRESTHA  Binu TIMSINA 《山地科学学报》2012,9(2):201-213

This study aimed to compare the distribution patterns and trends of plant parts used among different groups of medicinal plants, geographical regions,and between medicinal plants and all vascular plants.We used the published sources for elevation records of 2,331 medicinal plant species to interpolate presence between minimum and maximum elevations and estimated medicinal plant richness for each 100-m elevational band. Monte Carlo simulations were used to test whether differences in elevational distribution between different groups of medicinal plants were significant. Total number of medicinal plants as well as different groups showed unimodal relationship with elevation. The elevational distributions of medicinal plants significantly differ between regions and between medicinal plant groups.When comparing the richness of all medicinal plants to all vascular plants,Monte Carlo simulations indicated that the numbers of medicinal plants are higher than expected at low elevations.The highest richness of medicinal plants at low elevation could be possibly due to favorable environmental factors such as high temperature, rainfall,sunlight or due to higher density of human population and thus higher pressure on use of any plants in lower elevations.  相似文献   

Application of groundwater hydraulics to a basaltic water-table aquifer     

P.G. Adyalkar  V.V.S. Mani 《Journal of Hydrology》1974,21(3):211-218

Analysis of pump-test data of open wells in a basaltic water-table aquifer is made with methods based on both equilibrium and non-equilibrium formulae. The study has indicated that the Thiem's equilibrium formula and the ratio method of Narasimhan appear to be more suitable as compared with Jacob's and Chow's methods. Of the two, Narasimhan's ratio method, which does not require the graphical procedure, is more reliable than the Thiem's method since the latter involves an assumption of the value for the radius of influence. From the value of T (coefficient of transmissibility) obtained by Narasimhan's method it is also possible to calculate the value of the radius of influence by Thiem's method, which can be used in determining the required spacing between wells in the basaltic terrain in order to avoid mutual interference.  相似文献   

Studies of variations in the vertical ozone profiles over India     

Mani  A.  Sreedharan  C. R. 《Pure and Applied Geophysics》1973,106(1):1180-1191

The latitudinal and temporal variations in the vertical profiles of ozone over the Indian subcontinent are discussed. In the equatorial atmosphere represented by Trivandrum (8°N) and Poona (18°N), while tropospheric ozone shows marked seasonal variations, the basic pattern of the vertical distribution of ozone in the stratosphere remains practically unchanged throughout the year, with a maximum at about 28 to 26 km and a minimum just below the tropopause. The maximum total ozone occurs over Trivandrum in the summer monsoon season and the latitudinal anomaly observed over the Indian monsoon area at this time is explained as arising from the horizontal transport of ozone-rich stratospheric air from over the thermal equator to the southern regions.In the higher latitudes represented by New Delhi (28°N), the maximum occurs at 23 km. Delhi, which lies in the temperate regime in winter, shows marked day-to-day variations in association with western disturbances and the strong westerly jet stream that lies over north and central India at this time.Although the basic pattern of the vertical distribution of ozone in the equatorial atmosphere is generally the same in all seasons, significant though small changes occur in the lower stratosphere and in the troposphere. There are small perturbations in the ozone and temperature structures, distinct ozone maxima being always associated with temperature inversions. There are also large perturbances not related to temperature, ozone-depleted regions normally reflecting a stratification of either destructive processes or materials such as dust layers or clouds at these levels. Particularly interesting are the upper tropospheric levels just below the tropopause where the ozone concentration is consistently the smallest, in all seasons and at all places where soundings have been made in India.  相似文献   

Electrical conductivity and potential gradient measurements in the free atmosphere over India     

G. P. Srivastava  B. B. Huddar  Anna Mani 《Pure and Applied Geophysics》1972,100(1):81-93

Summary Results of measurements of atmospheric electrical potential gradient and conductivity in the free atmosphere using balloon borne radiosondes made at a few stations in India are presented. The potential gradient generally decreases exponentially with height above the exchange layer and the electrical conductivity profiles show corresponding mirror image symmetry. Large variations of electrical potential gradient and conductivity are, however, observed in the troposphere closely associated with clouds, dust and haze and other local meteorological phenomena and space charge effects. Significant though small variations are also observed in the stratosphere, which appear to be associated with the existence of aerosol layers.From an analysis of integrated potential profiles the total atmospheric potential has been calculated and found to have a mean value of 300 kV; the ionospheric potential varies diurnally and seasonally about the mean.

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Zusammenfassung Messungen der luftlelektrischen Leitfähigkeit und des atmosphärischen Potentialgradienten werden berichtet, welche mit ballongetragenen Radiosonden in der freien Atmosphäre über Indien ausgeführt worden sind. Oberhalb der Austauschschicht vermindert sich das Potentialgefälle exponentiell mit der Höhe, während die Leitfähigkeitsprofile das dazu spiegelbildliche Bild zeigen. In der Troposphäre werden jedoch grosse Änderungen des Potentialgefälles und der Leitfähigkeit im Zusammenhang mit Wolken, Dunst, Staub und mit anderen meteorologischen Erscheinungen und mit Raumladungseffekten beobachtet. Auch in der Stratosphäre werden signifikante, wenn auch kleine Änderungen beobachtet, welche mit der Existenz von Aerosolschichten zusammen zu hängen scheinen.Das gesamte atmosphärische Potential wurde aus den integrierten Potential-gefällekurven berechnet zu 300 kV als Mittel gefunden; dieses Ionosphärenpotential zeigt Veränderungen um diesen Mittel in Form von Tagesgängen und Jahresgängen.

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