IR@CIMFR - Central Institute of Mining and Fuel Research (CSIR)
Not a member yet
2618 research outputs found
Sort by
Estimation of Total Carbon Stock of Kakinada Mangrove using Normalized Difference Vegetation Index, East Godavari, Andhra Pradesh
No full textMangroves hold a significant amount of carbon and play a critical role in the earth's climate system. To this date, carbon stock had never been estimated for Kakinada mangroves with NDVI especially in Coringa which has been affected by disturbances (e.g.: Gathering Fuelwood, Fish Farming, and Prawn Farming). Understanding the multi-temporal dynamics of carbon stocks over Kakinada forests is very crucial because previous land use land cover change activities have modified the land for unsustainable aquaculture. During the study, we described arobust approach to estimate the carbon content of mangroves by using Normalized Difference Vegetation Index features. Normalized Difference Vegetation Index has features based on nearinfrared spectrum absorption for the different vegetation classes. Further sliced Normalized Difference Vegetation Index values from 0.15 to 0.64 have been used to calculate the aboveground biomass stock and belowground biomass stock which was afterward concluded as total carbon stock. Normalized Difference Vegetation Index based estimation of aboveground carbon stock results as 41.311 ±13 Mg ha-1, whereas belowground carbon estimated as 71.382 ± 20 Mg ha-1. Final results for Total carbon calculated by AGC and BGC is 112.694 ± 26 Mg ha-1. Additionally, linear regression analysis shows positive Skewness between the NDVI and the carbon stock. The Pearson correlation was calculated based on the independent (Carbon values) and dependent variable (NDVI) results in a value of 0.9
Safe exploitation of developed pillars of a coalseam above fire affected areas – a case study
No full textt was an extremely challenging task from the safety standpoint to exploit the developed coal pillars in No. 15 top and bottom seams at the Tata Steel Ltd Sijua Colliery by deep-hole opencast blasting above fire affected areas in No. 13 seam and No. 14 seam and a depillaring panel in No. 10 seam. The danger was that the depillaring operations in No. 10seam could cause subsidence on the floor of the opencast workings and that the ground vibrations generated due to opencast blasting could destabilize the underground fire areas and cause structural damage to isolation stoppings in No. 13 and 14 seams. The scientific approach proposed by the authors may make it possible to extract the locked-up coal without jeopardizing the safety of the fire affected and depillared panel
Numerical analysis of LSPR based fiber sensor for low refractive index detection
No full textIn this work, we have proposed localized surface plasmon resonance (LSPR) based optical fiber sensors using silver nanowires (AgNWs) for low refractive index (RI) detection. The sensing structure contains a semi-circular channel (SCC) incorporated with tightly placed multiple AgNWs inside the channel. The sensing behavior and the coupling phenomenon of the design are numerically investigated using full vectorial finite element method (FEM) based on COMSOL multiphysics. The sensing performance has been carried out by investigating optimized value of structural parameters such as channel separation (D), the radius of Ag nanowires (rn) and lastly the size of SCC (s). The proposed design exhibits a maximum sensitivity of 3725 nm/RIU for low RI analytes (na) varying from 1.27 to 1.33. The proposed sensing structure is designed in such a way that it can be utilized in various sensing applications even with a small amount of measuran
Valorisation of agricultural biomass-ash with CO2
No full textThis work is part of a study of different types of plant-based biomass to elucidate their capacity for valorisation via a managed carbonation step involving gaseous carbon dioxide (CO2). The perspectives for broader biomass waste valorisation was reviewed, followed by a proposed closed-loop process for the valorisation of wood in earlier works. The present work newly focusses on combining agricultural biomass with mineralised CO2. Here, the reactivity of selected agricultural biomass ashes with CO2 and their ability to be bound by mineralised carbonate in a hardened product is examined. Three categories of agricultural biomass residues, including shell, fibre and soft peel, were incinerated at 900 ± 25 °C. The biomass ashes were moistened (10% w/w) and moulded into cylindrical samples and exposed to 100% CO2 gas at 50% RH for 24 h, during which they cemented into hardened monolithic products. The calcia in ashes formed a negative relationship with ash yield and the microstructure of the carbonate-cementing phase was distinct and related to the particular biomass feedstock. This work shows that in common with woody biomass residues, carbonated agricultural biomass ash-based monoliths have potential as novel low-carbon construction products
Coal Pillar Extraction Under Weak Roof
No full textThis article offers an examination of a retreat mining method conducted at the Pinoura Mine in India from 2010 to 2017. The method is atypical for coal mines of India’s coalfields. The method executes depillaring in a single pass and does not require the formation of galleries and support installation in splits, thus, reducing the cycle time. A variety of observations are discussed throughout this work and emphasis is placed on field measurements and depillaring under weak roof (RMR = 40–45). This paper discusses design techniques, specifically the estimation of the snook (remnant pillar) size, and important practical observations after the fact. The execution of this method was eventually conducted in eleven panels
Preparation and Certification of Indian Reference Material of Bituminous Coal
No full textCertified reference materials (CRMs) are used for evaluating analytical methods, quality assurance and traceability of analytical results to international standards. Bituminous coal is the medium grade coal with high heating capacity and low moisture content. CRM of bituminous coal powder (BND 5101A) has been developed and certified for ash, gross calorific value (GCV),volatile matter (VM) and total sulphur (S) content as 22.16 ± 0.15%; 6114 ± 44 kcal/kg; 29.2 ± 0.36% and 0.71 ± 0.04%, respectively. The sample of coal selected for the purpose is high-rank bituminous type, which was collected from an opencast mine of Central Coalfields Ltd. The work has been carried out jointly by CSIR-Central Institute of Mining and Fuel Research (CSIR-CIMFR), Dhanbad and CSIR-National Physical Laboratory (CSIR-NPL), New Delhi. Proficiency testing (PT) program was carried out among 28 reputed coal laboratories of the country in accordance with ISO/IEC 17043:2010. Based on the performance of laboratories in the PT program, 8 laboratories were selected for inter-laboratory comparison (ILC) program as per ISO 13528:2015. This paper describes the methodology employed for the preparation of a coal reference material, homogeneity, stability studies and the ILC analytical and statistical work performed for the certification of the contents of ash, GCV, VM and total S
Transesterification of Jatropha curcas Oil by using K Impregnated CaO Heterogeneous Catalyst
No full textGrowing environmental concern and fast depletion of conventional fossil fuel resources have induced an urgent search for alternative energy sources. In this regard, biodiesel obtained from Jatropha oil (a non-food oil), seems to be a very promising alternative. Though a lot of research is already done in catalytic transesterification, in the present work, conversion of high FFA (5.5%) bearing Jatropha oil to methyl ester was studied using synthesized KF/CaO solid catalyst.
The novelty of this heterogeneous catalyst is the omission of two major steps — neutralization step in which acid is used followed by transesterification using the basic homogeneous catalyst. The catalyst KF/CaO is easily prepared from cheap chemicals and is safe for the environment. The catalyst was characterized by mean of TPD of CO2, X-ray diffraction, BET surface area (SA) analyzer. Catalytic transesterification of this oil was studied with different reaction parameters to
achieve a 97% conversion. Optimization of conditions (molar ratio of methanol/oil, time, temperature and catalyst dosage) was also established. The present work makes the process not only safer to the environment but also shows the gateway for greener alternatives to the energy of high FFA oils
Predicting Blast-Induced Ground Vibrations in Some Indian Tunnels: a Comparison of Decision Tree, Artificial Neural Network and Multivariate Regression Methods
Get PDFThe present study compares three different techniques (decision tree, artificial neural network and multivariate regression analysis) for predicting blast-induced ground vibrations in some Indian tunnelling projects. The performance of these models was also compared to site-specific conventional predictor equations. A database consisting of 137 vibration records was randomly divided into training and testing sets for model generation. Eight input parameters (total charge, tunnel cross-section, maximum charge per delay, number of holes, hole diameter, distance from blasting face, hole depth and charge per hole) were selected for model development using bivariate correlation analysis. Results indicated that the decision tree is best suited for predicting vibrations. The decision tree further suggested that the intensity of near-field ground vibrations is mainly affected by total charge fired in a round, whereas the intensity of far-field vibrations is governed by maximum charge per delay and charge per hole. Conventional ground vibration predictors and machine learning techniques such as neural networks do not depict the relationship between input and output parameters. However, the present study substantiates that the decision tree can be a good tool for precise prediction of ground vibrations. Further, the decision tree can classify and relate different blast design parametersfor refining blast designs to control ground vibrations on site
Application of TG technique to determine spontaneous heating propensity of coals
No full textThe TG method is applied to eleven coal samples of varying rank collected from across the Jharia coalfield, India, to determine spontaneous heating susceptibility. Previous literature does not agree as to the TG experimental parameter that characterizes the spontaneous heating susceptibility of coal. A series of TG experiments were performed on triplicate samples of each coal to determine the susceptibility of coal to spontaneous heating. Each prepared sample had the following properties: mass–10 mg, size distribution − 212 µm, and was subjected to a sample gas flow rate of 40 mL min−1 and a balance gas flow rate of 60 mL min−1 under the following four different heating rates: 1, 5, 15 and 30 °C min−1. The study concludes that the heating rate of 5 °C min−1 should be used to determine the spontaneous heating susceptibility. The experimental data obtained are subjected to chemo-metric tools, i.e. principal component analysis and hierarchical clustering analysis to establish any linkage between the coal characteristics parameters and spontaneous heating susceptibility indices. These analyses reveal that the self-heating (Tsh) and ignition temperature (Tign) determined from the TG experiment results may indicate the susceptibility of coal to spontaneous heating, which is corroborated by well-established standard experiments as well as with field observations
Geochemical attributes for source rock and palaeoclimatic reconstruction of the Auranga Basin, India
No full textThe present study aims to investigate the source and palaeoenvironmental conditions prevailed during the deposition of the Lower Permian shales of the Auranga Basin located at western flank of the Damodar valley, India. Both organic and inorganic geochemistry have been applied as tools to accomplish the objectives of this investigation. The n-alkane distribution within the samples reveals the dominance of the intermediate chain length n-alkanes over the short chain as well as long chain length homologues, possibly implying the organic matter derivation from the ferns, sphagnum moss, gymnosperms and/or aquatic plants. The intermediate chain n-alkane concentration along with its relations with the preference indices of odd to even carbons and proxy ratio as well as with average chain length may suggest the submergent aquatic plant communities as principle contributors of organic materials to the peatland. The presence of short chain length alkanes with pentacyclic triterpenoids may indicate the microbial organic matter input. The complete absence of <n-C16 alkanes and baseline humps in the pentacyclic triterpenoid chromatograms may indicate the influence of biodegradation of the organic matter in the shale samples. The pristane to phytane ratio (0.08–4.66) and the relation between pristane/n-C17 and phytane/n-C18 may imply transitional redox condition within the mire. The pristane/n-C17 ratio (0.08–1.24) may indicate the alternations of open water and swampy environments. The chemical weathering indices calculated from major elemental oxides may infer moderate to strong weathering due to reasonable period of precipitation during a wet spell. The selective trace element ratios and the palaeoclimatic factor (0.60–1.73) may, additionally, suggest high atmospheric humidity and consequent heavy precipitations that flourished the aquatic plants, which would have dominantly supplied the organic detritus in the peatland. In complementary, the hopanoid ratios, especially, the 22S/(22S + 22R) homohopane ratio may mark that the organic matter within the Auranga shales is in immature to early maturity phase for oil generation. Moreover, the combined mean random vitrinite reflectance and the thermal maturity parameter obtained from the Rock Eval data may indicate oil potential of these shales