IR@CIMFR - Central Institute of Mining and Fuel Research (CSIR)
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Recent insights into the dissolved and particulate fluxes from the Himalayan tributaries to the Ganga River
No full textThe Ganga River plays a major role in the transfer of materials from the Indian sub-continent to the Bay of Bengal, both in dissolved and particulate forms. To understand the present elemental dynamics of the Ganga River system, it is important to assess the hydrogeochemical contribution of its tributaries. In this paper, we present an updated database on dissolved and particulate fluxes and denudation rates of the Himalayan tributaries of the Ganga River (Ramganga, Ghaghara, Gandak and Kosi). Dissolved trace element concentrations, their fluxes and suspended sediment-associated elemental fluxes of the Himalayan tributaries have been reported for the first time. Total dissolved flux of the Ramganga, Ghaghara, Gandak and Kosi was estimated as 4, 19.1, 10.3 and 8.8 million tons year−1 accounting for ~ 5.7, ~ 27.3, ~ 14.7 and ~ 12.6%, respectively, of the total annual dissolved load carried by the Ganga River. The total particulate flux of the Ramganga, Ghaghara, Gandak and Kosi was computed as 8.2, 81.6, 30.9 and 19.5 million tons year−1, respectively. Compared to earlier studies, we have found a significant increase in the total dissolved flux and chemical denudation rate of the studied tributaries. The estimated particulate fluxes were found to be low in comparison to the previous studies. We suggest that a significant increase in the dissolved fluxes and a decrease in the particulate fluxes are an indication of the increasing anthropogenic disturbances in the catchment of these tributaries
Forest Cover Change Analysis Based on Remote Sensing & GIS of West Singbhum District, Jharkhand
No full textForest is a part of the land surface of the earth, with lots of plants and animals, they are need forests to live and survive. The major objective of this study is to detect the magnitude of forest cover change in the duration of the last 20 years (1997 to 2017) in West Singhbhum district of Jharkhand, India. The spectral information of the satellite image is more important to generate forest cover change model using LULC, NDVI and SAVI. The data included a series of topographical sheets, open series maps and satellite imageries from Landsat-5 TM (1997) and Landsat-8 OLI (2017) to recognize forest cover changes during the chosen period. A very useful method used to complete the study, which are generation of Land Use/Land Cover (LULC), Normalized Difference Vegetation Index (NDVI) and Soil Adjusted Vegetation Index (SAVI) model of the study area. The LULC employing the maximum likelihood supervised classification (MLC) algorithm mainly focused on forest cover and other parameters. On the classified map, accuracy assessment is performed, which produced error matrices and overall accuracy, the calculated overall accuracy found 87.18% in 1997 and 86.11% by 2017. The change detection analysis revealed that the area has remarkable changes specifically, the forest covers land reduced 2017.037 km2 (26.17%) of the total study area of 5,364.789 km2 in between 20 years, 5079.723 km2 (65.58%) in 1997 to 3062.686 km2 (40.41%) in the year 2017. Key words: LU/LC, NDVI, Remote Sensing (RS), Geographic Information System (GIS), Change Detection, Image Differencing, Accuracy Assessment, Error Matrix
Influence of coal composition and maturity on methane storage capacity of coals of Raniganj Coalfield, india
No full textMethane generation primarily depends on the quantity, type and structure of kerogens and is controlled by temperature to which the precursor material is subjected over the geologic time whereas the gas-in-place depends on the storage capacity and burial history. The Raniganj Coalfield of India hosts significant reserves of good quality coals of Permian age belonging to two formations, Barakar and Raniganj. The adsorption characteristics of the nine regional (R-I to R-IX) and three local seams from Raniganj Formation of south-western part of the coalfield is thoroughly investigated in the light of reflectance, petrography and chemical composition for their CBM potential. Ash (A), moisture (M), volatile matter (VM) and fixed carbon (FC) of these coals range within 12.8–37.3%, 1.1–4.0%, 31.7–51.1% (daf) and 48.9–68.3% (daf), respectively. Carbon (C) varies within the range 77.0–86.8% (dmmf) and reflectance (Rr) within 0.62–0.87%. The coals are high volatile gas prone orthohydrous bituminous type. Both C and Rr increase, and M and VM decrease with depth. Vitrinite ranges mostly within 64.5–85.5%, inertinite 4.8–24.1% and liptinite below 15%, on mineral matter free basis. Most of the samples fall in Type-III kerogen and few are transitional to Type-II and Type-III. Gas content of the samples lies between 3.08 and 14.96 cc/g, on daf basis and generally increases with depth. Langmuir volume (VL) for the coals varies between 17.4 and 29.8 cc/g (daf) and exhibits a moderately positive linear relationship with increase in depth (R2 = 0.58). Reflectance shows a strong linear positive relationship (R2 = 0.70) with Langmuir volume indicating the development of additional micropores with rank enhancement, thereby providing more surface area for adsorption. Gas content results are encouraging though the seams are considerably undersaturated. A very good correlation is observed for the combined effect of ash, moisture and carbon on volume adsorbed for the studied coals and can be used to predict adsorption capacity from compositional data
Effect on microstructure of TMT welded bar under different cooling media
No full textArc welding is widely used for domestic as well as industrial purposes as it is very convenient to use. Mechanical properties such as tensile and hardness depend on microstructure. This paper presents the results of metallography examination of weld zone and heat affected zone (HAZ) in the welded rod which are welded and cooled in air, transformer oil, kerosene oil and water. The rate of cooling differs from each media thus there is microstructure change in weld zone as well as HAZ. In the weld zone, hardness is found to be more in case of transformer oil cooled sample in comparison with others cooling method applied here. The toughness of water cooled sample is found to, be more because of its presence of large amount of ferrite region along with pearlite and martensite. In the heat affected zone, water cooled sample is found to possess mare hardness due to formation of martensite. The arc welded transformer oil cooled sample seems to be best among all with regard to its structure, hardness and toughness
Empirical and probabilistic analysis of blast-induced ground vibrations
No full textAn attempt has been made to include an additional blast design parameter, burden, in obtaining the vector peak particle velocity, VPPV. A large set of about 640 blast data pertaining to different rock types from ten different sites in India and Turkey has been collected from the literature. Analysis of these data has been carried out resulting in the proposal of an empirical model for peak particle velocity with due consideration to the burden along with monitoring distance and maximum charge per delay. The performance of the proposed model has been compared with existing models, and the proposed model has been found to serve the purpose of predicting VPPV with greater accuracy. Further, probabilistic analysis of VPPV has been conducted by performing Monte-Carlo (MC) simulation on proposed empirical model. Typical results corresponding to Chittorgarh limestone mines in India are presented. The input parameters namely monitoring distance and maximum charge per delay have been assumed as lognormally distributed random variables, while the burden has been assumed as discreet variable. The analysis of results of MC simulations revealed that output or the state variable, VPPV follows a lognormal distribution. It was possible to take into account the variability in the blast parameters and therefore to study its influence on VPPV
In-Situ Stress Measurement in Raniganj Coalfield and Its Applications in Mine Stability Analysis
No full textThe in situ stresses have significant effects on the stability of openings, support requirements, parting stability, pillar strength, etc. In order to analyze the stability of underground structures, the measurement of magnitude and direction of horizontal stress is necessary in addition to knowing other geomining parameters and rock properties. In this direction, this paper presents a systematic determination of in situ stresses in three mines of the southern Raniganj coalfield of India, using single sleeve fracturing technique. Based on the analysis of field test results, the gradients of major, minor and average horizontal stresses are established for the southern Raniganj coalfield. The determined in situ stress values are used in numerical modeling for stability evaluation of known case histories of parting between contiguous seams and pillars of this coalfield. The numerical modeling results analyzed in this paper validated that the in situ stresses determined in the Raniganj coalfield are acceptable for the stability analysis of coal pillars, parting and underground roadways
A comparative Study between experimental and theoretical buckling load for hollow steel column
No full textHollow mild steel columns of same outer diameter and length but different wall thickness show the buckling behavior in different manner in the fix-fix end condition. The behavior of the column is in good agreement with Rankine’s formula. Additionally, there is a very strong relation between actual buckling load and buckling load by Rankine’s formula. There is some difference between the theoretical and actual buckling load which may be due to geometrical defect, crack generation, chemical composition and formation of eccentricity. Columns show that the variation of differences between actual and theoretical buckling load with respect to wall thickness is parabolic in nature
Fluorescent chemodosimeter for quantification of cystathionine-c-synthase activity in plant extracts and imaging of endogenous biothiols†
No full textBiofilm development of Bacillus thuringiensis on MWCNT buckypaper: Adsorption-synergic biodegradation of phenanthrene
No full textAdsorption-synergic biodegradation of a model PAH (phenanthrene, Phe) on MWCNT buckypaper surface with a potential PAH biodegrading bacterial strain Bacillus thuringiensis AT.ISM.11 has been studied in aqueous medium. Adsorption of Phe on buckypaper follows Dubinin-Ashtakhov model (R2 = 0.9895). MWCNT generally exerts toxicity to microbes but adsorbed layer of Phe prevents the direct contact between MWCNT and bacterial cell wall. FESEM study suggests that formation of biofilms occurred on buckypaper. Lower layer cells are disrupted and flattened as they are in direct contact with MWCNT but the upper layer cells of the developed biofilm are fully intact and functional. Force-distance curves of Bacillus thuringiensis AT.ISM.11 with buckypaper indicates adhesion forces varied from −10.3 to −15.6 nN with increasing contact time, which supports the phenomenon of biofilm formation. AFM surface statistical data of buckypaper suggests increase in bacterial cell count increases the Rms roughness (95.7242–632.565) while adhering to the buckypaper surface to form biofilm. We observed an enhanced Phe biodegradation of 93.81% from that of the 65.71% in 15 days’ study period, using buckypaper as a bio-carrier or a matrix for the microbial growth. GC-MS study identified phthalic acid ester as metabolite, which is the evidence of protocatechuate pathway degradation of Phe. Current study enlightens the interaction between hydrocarbons and microbes in presence of MWCNT buckypaper matrix in aqueous system for the first time. An enhancement in biodegradation of Phe by 28.10% has also been reported which can be a basis for CNT aided enhanced biodegradation studies in future
Exposure and cancer risk assessment of polycyclic aromatic hydrocarbons (PAHs) in the street dust of Asansol city, India
No full textThe sources, distribution and total concentration of 16 polycyclic aromatic hydrocarbons (PAHs) in 15 urban street dust samples (each for summer, winter and monsoon season) from Asansol, an industrial city were investigated to evaluate and understand the carcinogenic risk of urban inhabitants exposed to street dust. The results showed that the total PAHs (∑PAHs) in urban street dust at Asansol ranged from 1708± 1345 ng/g to 9688 ± 3257 ng/g with an average value of 4532 ± 2031 ng/g. The 2-ring to 3-ring PAHs dominated in winter; whereas 5-ring to 6-ring PAHs contributed maximum in summer. Principal component analysis (PCA) and ratio determination were performed to identify the potential sources of PAHs. Anth/(Phe + Anth), BaP/BghiP, Fla/(Pyr + Fla), IP/(IP + BghiP), Flt/Pyr, Phen/Anth, and BaA/Chry ratios indicated mixed sources of PAHs. Our result concluded that at Asansol, biomass combustion, coal combustion, traffic emission (gasoline and diesel powered vehicles), thrash burning and domestic coal utilization activity, along with temperature and meteorological dependent played an important role in controlling the distribution of PAHs in street dust. According to the Incremental Lifetime Cancer Risk (ILCR) model, the total cancer risk for children and adults were maximum at industrial sites, i e., 1.4E-05 and 1.5E-05 respectively