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Mandal, A.
- DC Resistivity Studies for Mapping Groundwater Contamination in and around Ash-Disposal Site of Kolaghat Thermal Power Plant, West Bengal
Abstract Views :185 |
PDF Views:2
Authors
Affiliations
1 Department of Geology and Geophysics, IIT Kharagpur, Kharagpur - 721 302, IN
1 Department of Geology and Geophysics, IIT Kharagpur, Kharagpur - 721 302, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 69, No 2 (2007), Pagination: 373-380Abstract
Coal combustion in thermal power plants contributes to more than 70% of the e1ectricity generated in India. Combustion of coal generates huge amounts of wastes which are disposed off in nearby ponds. The ash generated from the coal combustion process contains a lot of toxic elements which are leached out by the percolating rain water and subsurface runoff from the ash ponds. These toxics cause sufficient amount of groundwater contamination.
DC resistivity studies are very helpful in determining the subsurface lithology and in delineating the zones of groundwater contamination. The present study was conducted in and around the ash disposal sites of Kolaghat Thermal Power Plant in West Bengal. Six Schlumberger soundings were conducted in the four ash ponds of the thermal power plant. The quantitative interpretation of the VES curves has been done by a very fast simulated annealing computer program developed for this purpose. The subsurface lithology as determined from the VES curves shows alternate layers of clay and sand upto a depth of 6Om. All the sounding locations show a general thin top layer of ash of high resistivity mixed with coarse sand or clay followed by a 29-50m thick layer of wet clay of very low resistivity. The lowermost layer is sandy clay to clayey sand in all the cases. Groundwater samples have also been collected from the tube wells located near the ash ponds and analysed for pH, TDS and trace elements. Results of the chemical analysis show high values of TDS and high concentration of the toxics. Earlier studies on the geochemistry of the pond ash have shown that the ashes are characterized by hlgh concentration of As, Pb, Cu, Ni, Fe, Zn, Cr, CO, Mn all of which exceed the crustal abundance by a factor of 3-5. The high concentration of the toxics (As, Al, Li, As, Zn, Ag, Sb, Si, Mo, Ba, Rb, Se, Pb) in the water samples implies significant input from the ash pile due to leaching. This increases the TDS values of the water. The low resistivity values of the intermediate clayey layer along with the high values of TDS and high concentration of the toxics imply that the contaminant zone lies at a shallow depth of 29-50m thick. It is formed due to leaching of the toxics from the top sandy layer and adsorption in the clayey layer.Keywords
Ash pond, Groundwater contamination, Resitivity survey, Thermal power plant, Geochemical analysis.
- Soil Degradation Effect on Soil Productivity, Carbon Pools and Soil Enzyme Activity
Abstract Views :273 |
PDF Views:90
Authors
Narendra K. Lenka
1,
S. P. Jaiswal
1,
J. K. Thakur
1,
S. Lenka
1,
A. Mandal
1,
A. K. Dwivedi
2,
B. L. Lakaria
1,
A. K. Biswas
1,
A. K. Shukla
1,
D. S. Yashona
1
Affiliations
1 Indian Institute of Soil Science, Nabibagh, Bhopal 462 038, IN
2 Jawaharlal Nehru Krishi Viswa Vidyalaya, Jabalpur 482 004, IN
1 Indian Institute of Soil Science, Nabibagh, Bhopal 462 038, IN
2 Jawaharlal Nehru Krishi Viswa Vidyalaya, Jabalpur 482 004, IN
Source
Current Science, Vol 112, No 12 (2017), Pagination: 2434-2439Abstract
Land degradation is one of the major causes of decline in soil productivity. However, the quantitative relationship between degradation and productivity is not fully understood in soils of India. Thus, an experiment was conducted under a range of native soil organic carbon (SOC) levels in two soil types (Inceptisol and Alfisol) of subtropical India. The SOC content under the treatments was 1.61%, 1.01% and 0.77% in Inceptisol and 0.36%, 0.25% and 0.21% in Alfisol under C1 (undepleted soil), C2 (low depletion) and C3 (medium depletion) treatments respectively. Soybean was grown under each SOC level, with four management practices, viz. (1) control, (2) recommended dose of fertilizers (RDF) + 10 Mg farmyard manure (FYM) ha-1, (3) 20 Mg FYM ha-1 and (4) 150% RDF, in three replicates in a factorial completely randomized design. Results indicated significant and positive effect of both SOC and management treatment on plant biomass yield, labile (KMnO4 oxidizable) carbon, soil microbial biomass carbon (SMBC), dehydrogenase activity, soil bulk density (BD) and penetration resistance (PR). The plant biomass reduced by 45% and 29% under C3 (compared to C1) in Inceptisol and Alfisol respectively. The effect of SOC depletion was conspicuous in Inceptisol. The labile C reduced by 47% and 16% under C3 in Inceptisol and Alfisol respectively. SMBC showed a corresponding decrease of 33% and 29%. The soil physical properties, viz. BD and PR showed conspicuous effect of SOC depletion. PR increased by 324% and 75% for Inceptisol and Alfisol respectively.Keywords
Labile Carbon, Soil Degradation and Productivity, Soil Microbial Biomass, Soil Physical Properties.Full Text
References
- Lal, R., Societal value of soil carbon. J. Soil Water Conserv., 2014, 69, 186–192.
- García-Díaz, A., Allas, R. B., Gristina, L., Cerdà, A., Pereira, P. and Novara, A., Carbon input threshold for soil carbon budget optimization in eroding vineyards. Geoderma, 2016, 271, 144–149.
- Bationo, A., Kihara, J., Vanlauwe, B., Waswa, B. and Kimetu, J., Soil organic carbon dynamics, functions and management in West African agro-ecosystems. Agric. Syst., 2007, 94, 13–25.
- Musinguzi, P., Ebanyat, P., Tenywa, J. S., Basamba, T. A., Tenywa, M. M. and Mubiru, D., Precision of farmer-based fertility ratings and soil organic carbon for crop production on a Ferralsol. Solid Earth, 2015, 6, 1063–1073.
- Lal, R., Soil carbon sequestration impacts on global climate change and food security. Science, 2004, 304, 1623–1627.
- Ladha, J. K., Dawe, D., Pathak, H., Padre, A. T., Yadav, R. L. and Singh, B., How extensive are yield declines in long-term rice–wheat experiments in Asia? Field Crops Res., 2003, 81, 159–180.
- Blair, G. J., Lefroy, R. D. B. and Lisle, L., Soil carbon fractions based on their degree of oxidation and the development of a carbon management index for agricultural systems. Aust. J. Agric. Res., 1995, 46, 1459–1466.
- Lal, R., Enhancing crop yields in the developing countries through restoration of the soil organic carbon pool in agricultural lands. Land Degrad. Dev., 2006, 17, 197–209.
- Lenka, N. K., Sudhishri, S., Dass, A., Choudhury, P. R., Lenka, S. and Patnaik, U. S., Soil carbon sequestration as affected by slope aspect under restoration treatments of a degraded alfisol in the Indian sub-tropics. Geoderma, 2013, 204–205, 102–110.
- Bauer, A. and Black, A. L., Quantification of the effect of soil organic matter content on soil productivity. Soil Sci. Soc. Am. J., 1994, 58, 185–193.
- Benbi, D. K. and Chand, M., Quantifying the effect of soil organic matter on indigenous soil N supply and wheat productivity in semiarid sub-tropical India. Nutr. Cycling Agroecosyst., 2007, 79, 103–112.
- Lenka, N. K., Mandal, D. and Sudhishri, S., Permissible soil loss limits for different physiographic regions of West Bengal. Curr. Sci., 2014, 107, 665–670.
- Loveland, P. and Webb, J., Is there a critical level of organic matter in the agricultural soils of temperate regions: a review. Soil Till. Res., 2003, 70, 1–18.
- Weil, R. R., Islam, K. R., Stine, M. A., Gruver, J. B. and SamsonLiebig, S. E., Estimating active carbon for soil quality assessment: a simplified method for laboratory and field use. Am. J. Alternat. Agric., 2003, 18, 3–17.
- Vance, E. D., Brookes, P. C. and Jenkinson, D. S., An extraction method for measuring soil microbial biomass carbon. Soil Biol. Biochem., 1987, 19, 703–707.
- Bremner, E. and Kesssel, V. C., Extractability of microbial 14C and 15N following addition of variable rates of labeled glucose and ammonium sulphate to soil. Soil Biol. Biochem., 1990, 22, 707–713.
- Klein, D. A., Loh, T. C. and Goulding, R. L., A rapid procedure to evaluate the dehydrogenase activity of soils low in organic matter. Soil Biol. Biochem., 1971, 3, 385–387.
- Manna, M. C. et al., Long-term effect of fertilizer and manure application on soil organic carbon storage, soil quality and yield sustainability under sub-humid and semi-arid tropical India. Field Crops Res., 2005, 93, 264–280.
- Lenka, N. K., Choudhury, P. R., Sudhishri, S., Dass, A. and Patnaik, U. S., Soil aggregation, carbon build up and ischolar_main zone soil moisture in degraded sloping lands under selected agroforestry based rehabilitation systems in eastern India. Agric. Ecosyst. Environ., 2012, 150, 54–62.
- Parametric Optimization of Pulsed Nd:YAG Laser Micro-Grooving of Alumina through an Artificial Neural Network Model
Abstract Views :161 |
PDF Views:0
Authors
Affiliations
1 Dept. of Mechanical Engg., North Eastern Regional Institute of Science and Technology, Nirjuli, IN
1 Dept. of Mechanical Engg., North Eastern Regional Institute of Science and Technology, Nirjuli, IN
Source
Manufacturing Technology Today, Vol 7, No 6 (2008), Pagination: 3-9Abstract
Pulsed Nd:YAG laser beam has great ability for micro-machining of ceramic materials because of high laser beam intensity at low mean beam power, good focusing characteristics due to very small pulse duration, small kerf widths and narrow heat affected zones. In the present research, micro-grooving of alumina ceramic plate by pulsed Nd:YAG laser beam machine is studied. Selection of optimum machining parameter combinations for obtaining accuracy is the challenging task in laser micro-grooving operation. Nowadays several numerical methods are widely used for either modeling or optimizing the performance of the manufacturing technologies. That has been advanced due to the large diffusion of the personal computer and the numerical algorithms. This paper represents an attempt to develop an appropriate machining strategy for obtaining most accurate dimension of the micro-groove and to prepare a database for assistance during laser micro-grooving operation. A feed-forward back-propagation neural network is developed to model machining process. The three most important process parameters-lower width, upper width and depth of the groove-have been considered as measures of process performance. The model is capable of predicting the response parameters as a function of five different control parameters i.e. lamp current, pulse frequency, pulse width of the duty cycle, assist air pressure and cutting speed.- Geological and Geotechnical Approach for Excavation of Large Unlined Rock Cavern
Abstract Views :260 |
PDF Views:81
Authors
Affiliations
1 Department of Civil Engineering, Visvesvaraya National Institute of Technology, Nagpur - 440 010, IN
2 Sub-Surface Project Division, 2nd Floor, EIB Engineers India Limited, New Delhi 110 066, IN
1 Department of Civil Engineering, Visvesvaraya National Institute of Technology, Nagpur - 440 010, IN
2 Sub-Surface Project Division, 2nd Floor, EIB Engineers India Limited, New Delhi 110 066, IN
Source
Current Science, Vol 115, No 4 (2018), Pagination: 638-643Abstract
The degree of uncertainty involved in an underground storage project is relatively higher compared to other underground projects. In order to allow for a safe and economical construction of underground rock caverns, continuous updating of the geological and geotechnical model along with adjustment in construction approach is required. Investigations planned during different stages of excavation of the project assist in the identification of various geological features and ground characteristics to ensure robust design of underground structures. Investigation in each stage of the project is planned in line with the time and money available at that stage, along with level of detailing required for different design stages. In order to develop an efficient investigation scheme, it is necessary to assimilate the existing information from one stage before planning for the next stage of investigations. This article highlights the significance of various investigations carried out for one of the strategic storage site in the southern part of India.Keywords
Geotechnical and Geological Investigations, Cavern, Tunnelling, Underground Excavations, Rock.Full Text
References
- Nanda, A., Rath, R. and Usmani, A., Underground storage technology, Engineers India Ltd, New Delhi, 2016.
- Becker, A. and Davenport, C. A., Contemporary in situ stress determinations at three sites in Scotland and northern England. J. Struct. Geol., 2001, 23(2–3), 407–419.
- Hoek, E. and Brown, E. T., Underground excavations in rock. Institution of Mining and Metallurgy, London, 1980.
- Barton, N., Some new Q-value correlations to assist in site char-453 characterization and tunnel design. Int. J. Rock Mech. Min. Sci., 2002, 39(2), 185–216.
- Barton, N. and Bandis, S., Review of predictive capabilities of JRC–JCS model in engineering practice. In Proceedings of the International Symposium on Rock Joints (eds Barton, N. and Stephansson, O.). Balkema, Rotterdam, The Netherlands, 1990.
- IS: 11315 – Part-4, Method for quantitative description of discontinuities in rock mass, Part-5: Roughness. Bureau of Indian Standard, New Delhi, 2005.
- Barton, N., Lien, R. and Lunde, J., Engineering classification of rock masses for the design of tunnel support. Rock Mech., 1974, 6(4), 189–236.
- Science and Religion
Abstract Views :178 |
PDF Views:3
Authors
Affiliations
1 Inter University Accelerator Centre, New Delhi-110067, IN
1 Inter University Accelerator Centre, New Delhi-110067, IN
Source
Indian Science Cruiser, Vol 26, No 4SP (2012), Pagination: 44-46Abstract
Religion is prevailing in the society from the very creation of human society. Still it is regarded by many learned and rational persons as an unimportant factor in life. The main reason behind this thinking is the rituals and dogmatism practised by the followers of different sects which obscure the real aspects of the religion. Superficial aspects of the religions practised in different parts of the world differ from each other though the very essence of every religion is same-love and serve to mankind.
- Effect of Process Variables on Angular Distortion of Pulse MIG Welded HSLA Plates
Abstract Views :205 |
PDF Views:5
Authors
A. Mandal
1,
R. S. Parmar
2
Affiliations
1 Prod. Engg. Dept., NIFFT, Hatia, Ranchi, Bihar, IN
2 Mech. Engg. Dept., l.l.T. Delhi, New Delhi, IN
1 Prod. Engg. Dept., NIFFT, Hatia, Ranchi, Bihar, IN
2 Mech. Engg. Dept., l.l.T. Delhi, New Delhi, IN
Source
Indian Welding Journal, Vol 30, No 3 (1997), Pagination: 26-34Abstract
Angular distortion is a major problem and most pronounced amongst different types of distortion in the butt welded plates. It is difficult to obtain a completely analytical solution to the problem of anguiar distortion which may be reliable over a wide range of processes, materials and procedural variables. In this study, the statistical method of 2 level full factorial technique has been used to aevelop models which correlate angular distortion with Pulse MIG process variables and joint parameters.- Turbulent Fluid Flow and Heat Transfer through a Horizontal Rectangular Diffuser with the Use of Single and Double Baffles
Abstract Views :120 |
PDF Views:2
Authors
Affiliations
1 Department of Computer Science and Engineering, Jadavpur University, Kolkata-700 032, IN
2 Department of Mechanical Engineering, Heritage Institute of Technology, Kolkata-700107, IN
3 Deputy Director of Industrial Training, West Bengal, In-Charge of Govt. ITI Howrah Homes Technical Education, Training and Skill Development Department, Govt. of West Bengal, IN
4 Department of Mechanical Engineering, Jadavpur University, Kolkata-700032, IN
1 Department of Computer Science and Engineering, Jadavpur University, Kolkata-700 032, IN
2 Department of Mechanical Engineering, Heritage Institute of Technology, Kolkata-700107, IN
3 Deputy Director of Industrial Training, West Bengal, In-Charge of Govt. ITI Howrah Homes Technical Education, Training and Skill Development Department, Govt. of West Bengal, IN
4 Department of Mechanical Engineering, Jadavpur University, Kolkata-700032, IN
Source
Journal of the Association of Engineers, India, Vol 91, No 1-4 (2021), Pagination: 15-24Abstract
Scientists and engineers give much attention for convective fluid flow around the baffles because of its wide application in different types of heat exchangers used in industries. Analysis of the velocity profiles of the turbulent flow and convection flow parameters have been studied for a horizontal rectangular asymmetric diffuser, the bottom wall of which is being heated. Single and double baffles of equal height are used in the experiments. The experimental study has been carried out at Reynolds numbers of 3.594x104 3.986x104 and 5.371x104 with base plate temperatures of 323K and 343K respectively. Skin friction coefficient along the walls has been calculated. The variation of local Nusselt number along the upper wall is observed carefully. The effort is made to establish some new empirical relationships between Coefficient of skin friction and Nusselt number with Reynolds number The size of recirculation bubble is also calculated.Keywords
Turbulence, Baffles, Rectangular Diffuser, Skin Friction Coefficient, Reynolds Number.References
- Asif, M. R., Hossain, M. S. and Hossain, K. A., Heat Transfer in a Rectangular enclosure with Baffles, ARPN Journal of Engineering and Applied Sciences, Vol.6, No.4, pp.29-41, 2011.
- Razak, A. A., Yaakob, Y. and Ramli, M. N., Computational Simulation of Turbulence Heat Transfer in Multiple Rectangular Ducts, World Academy of Science, Engineering and Technology, Vol. 53, pp.242-246, 2009.
- Mehdi, Q. S. and Mushatet, K. S., Simulation of Turbulent Flow and Heat Transfer Through a Duct with Baffle Plates, Journal of Engineering and Development, Vol. 12, No.3, pp.142-157, 2008.
- Dogan, M. and Sivrioglu, M., Experimental investigation of mixed convection heat transfer from longitudinal fins in a horizontal rectangular channel. International Journal of Heat and Mass Transfer, Vol. 53, pp.2149-2158, 2010.
- El-Askary, W. A. and Abdel-Fattah, A., Experimental and Numerical Studies on Heat Transfer and Fluid Flow in a Duct Fitted with Inclined Baffles, Computer Modeling in Engineering and Sciences, Vol. 83, No.4, pp.425-457, 2012.
- Majumder, S., Roy, D., Bhattacharjee, S. and Debnath, R., Experimental Investigation of the Turbulent Fluid Flow Through a Rectangular Diffuser Using Two Equal Baffles, Journal of Institution of Engineers (India) Ser. C, Vol. 95, No.1, pp. 19-23, 2014.
- Bhattacharjee, S., Debnath, R., Mandal, A, Roy, D. and Majumder, S., Experimental Investigation Of Recirculatory Turbulent Flow Past Twin Obstructions Of Different Heights Placed At Different Stations Of A Rectangular Diffuser, Paper No. EM - 05, Proceedings of the 37th National & 4th International Conference on Fluid Mechanics and Fluid Power, December 16-18, IIT Madras, Chennai, India, pp.1-8, 2010.
- Lee, J., Jung, S. Y, Sung, H. J. and Zaki, T. A., Effect of wall heating on turbulent boundary layers with temperature-dependent viscosity. Journal of Fluid Mechanics, Vol. 726, pp. 196-225, 2013.
- Bhattacharjee, S., Mandal, A., Debnath, R., Majumder, S. and Roy, D., Effect of Bottom Wall Heating on the Turbulent Fluid Flow in an Asymmetric Rectangular Diffuser: an Experimental Study, Journal of Applied Fluid Mechanics, Vol. 9, No.6, pp. 2969-2979, 2016.