Browsing by Author "Hegde, C."

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A Critical Comparison of Regression Models and Artificial Neural Networks to Predict Ground Vibrations
(Springer International Publishing, 2017) Ram Chandar, K.; Sastry, V.R.; Hegde, C.
Blasting is important and an essential prerequisite in any opencast mine for fragmenting hard deposits. Blasting always produces unwanted effects like ground vibrations, noise and fly rock; among which ground vibrations effect is more on surrounding structures. Propagation of ground vibrations can lead to destruction of surrounding structures. Prediction of ground vibrations especially in terms of peak particle velocity is beneficial as opposed to conventional data monitoring techniques which can be expensive as well as time consuming. This paper uses predictors to estimate the intensity of ground vibrations and compares different methods of prediction methods like linear regression, multiple linear regression, non linear regression (NLR) and artificial neural networks. Intensity of ground vibrations generated from blasting operations was monitored in three different mines of limestone, dolomite and coal; obtaining about 168 ground vibration recordings in total. The statistical modelling or data-driven modeling has shown promise in the prediction of blast vibrations. Proposed a system of introducing site specific rock parameters like poison’s ratio, uniaxial compressive strength of rock and Young’s modulus to improve the correlation coefficient using statistical modelling (commonly called feature engineering in machine learning circles). © 2016, Springer International Publishing Switzerland.
Acoustic fingerprinting for rock identification during drilling
(2014) Shreedharan, S.; Hegde, C.; Sharma, S.; Vardhan, H.
During the process of mining, it is imperative to know the type and properties of the rocks being handled. The current technology for this involves core drilling, and subsequently subjecting the drilled cores to various tests in the laboratory, to identify the rocks and establish their properties. In many cases, obtaining a sample may be cumbersome and/or non-profitable. This paper presents a novel method to monitor and evaluate the sounds produced as undesirable by-products, at the drill-bit and rock interface, to predict the type of rock being drilled. A rotary drill was fabricated in the laboratory and vertical drilling was carried out on cubical rock samples, keeping various drilling parameters constant. The results obtained are promising and reinforce that it may be possible to extend the proposed methodology in the field as well, with appropriate modifications. This method may be extrapolated further in the estimation of rock properties as well. Copyright 2014 Inderscience Enterprises Ltd.
Acoustic fingerprinting for rock identification during drilling
(Inderscience Publishers, 2014) Shreedharan, S.; Hegde, C.; Sharma, S.; Vardhan, H.
During the process of mining, it is imperative to know the type and properties of the rocks being handled. The current technology for this involves core drilling, and subsequently subjecting the drilled cores to various tests in the laboratory, to identify the rocks and establish their properties. In many cases, obtaining a sample may be cumbersome and/or non-profitable. This paper presents a novel method to monitor and evaluate the sounds produced as undesirable by-products, at the drill-bit and rock interface, to predict the type of rock being drilled. A rotary drill was fabricated in the laboratory and vertical drilling was carried out on cubical rock samples, keeping various drilling parameters constant. The results obtained are promising and reinforce that it may be possible to extend the proposed methodology in the field as well, with appropriate modifications. This method may be extrapolated further in the estimation of rock properties as well. Copyright © 2014 Inderscience Enterprises Ltd.
Classification of Stability of Highwall During Highwall Mining: A Statistical Adaptive Learning Approach
(2015) Ram Chandar, K.; Hegde, C.; Yellishetty, M.; Gowtham, Kumar, B.
The depleting coal deposits day by day required the introduction of novel methods of mining like highwall mining. Highwall mining is a method of extraction of coal blocked in the highwall. The method involves considerable challenges in the area of roof control and most importantly the stability of the highwall itself. Highwall mining has gained considerable importance all over the world, owing to the fact that the coal otherwise would not be extracted forever. This paper aims to assess the influence of varying conditions which can affect the stability of the highwall during highwall mining. The effect of gallery length, width of pillar and number of galleries are systematically studied through field investigations where a highwall mining was adopted first time in India. Initially, assessment was carried out using a numerical modelling approach and then the stability of the highwall is classified using multilinear regression, logistic regression and naive Bayes classifier. This will provide a mechanism to predict the stability of the highwall in future cases of similar conditions. The classification is done using statistical adaptive learning methods and a comparison of the methods is done. 2014, Springer International Publishing Switzerland.
Classification of Stability of Highwall During Highwall Mining: A Statistical Adaptive Learning Approach
(Kluwer Academic Publishers, 2015) Ram Chandar, K.; Hegde, C.; Yellishetty, M.; Gowtham Kumar, B.
The depleting coal deposits day by day required the introduction of novel methods of mining like highwall mining. Highwall mining is a method of extraction of coal blocked in the highwall. The method involves considerable challenges in the area of roof control and most importantly the stability of the highwall itself. Highwall mining has gained considerable importance all over the world, owing to the fact that the coal otherwise would not be extracted forever. This paper aims to assess the influence of varying conditions which can affect the stability of the highwall during highwall mining. The effect of gallery length, width of pillar and number of galleries are systematically studied through field investigations where a highwall mining was adopted first time in India. Initially, assessment was carried out using a numerical modelling approach and then the stability of the highwall is classified using multilinear regression, logistic regression and naive Bayes classifier. This will provide a mechanism to predict the stability of the highwall in future cases of similar conditions. The classification is done using statistical adaptive learning methods and a comparison of the methods is done. © 2014, Springer International Publishing Switzerland.
A Critical Comparison of Regression Models and Artificial Neural Networks to Predict Ground Vibrations
(2017) Ram Chandar, K.; Sastry, V.R.; Hegde, C.
Blasting is important and an essential prerequisite in any opencast mine for fragmenting hard deposits. Blasting always produces unwanted effects like ground vibrations, noise and fly rock; among which ground vibrations effect is more on surrounding structures. Propagation of ground vibrations can lead to destruction of surrounding structures. Prediction of ground vibrations especially in terms of peak particle velocity is beneficial as opposed to conventional data monitoring techniques which can be expensive as well as time consuming. This paper uses predictors to estimate the intensity of ground vibrations and compares different methods of prediction methods like linear regression, multiple linear regression, non linear regression (NLR) and artificial neural networks. Intensity of ground vibrations generated from blasting operations was monitored in three different mines of limestone, dolomite and coal; obtaining about 168 ground vibration recordings in total. The statistical modelling or data-driven modeling has shown promise in the prediction of blast vibrations. Proposed a system of introducing site specific rock parameters like poison s ratio, uniaxial compressive strength of rock and Young s modulus to improve the correlation coefficient using statistical modelling (commonly called feature engineering in machine learning circles). 2016, Springer International Publishing Switzerland.
Ethyl 2-[(2,6-dimethylphenyl)-hydrazono]-3-oxobutanoate
(2009) Fun, H.-K.; Jebas, S.R.; Padaki, M.; Hegde, C.; Isloor, A.M.
The title compound, C14H18N2O3, crystallizes with two independent molecules in the asymmetric unit, having closely comparable geometries. Both molecules are essentially planar [maximum deviations from the mean plane of 0.069 (1) and 0.068 (1) for the two molecules] and contain an intramolecular N?H?O hydrogen bond which generates a ring with graph-set motif S(6). In the crystal, the molecules are linked into chains along the c axis by intermolecular C?H?O hydrogen bonds, and intermolecular C?H?? interactions are also present.
Ethyl 2-[(2,6-dimethylphenyl)-hydrazono]-3-oxobutanoate
(2009) Fun, H.-K.; Jebas, S.R.; Padaki, M.; Hegde, C.; Isloor, A.M.
The title compound, C14H18N2O3, crystallizes with two independent molecules in the asymmetric unit, having closely comparable geometries. Both molecules are essentially planar [maximum deviations from the mean plane of 0.069 (1) and 0.068 (1) Å for the two molecules] and contain an intramolecular N?H?O hydrogen bond which generates a ring with graph-set motif S(6). In the crystal, the molecules are linked into chains along the c axis by intermolecular C?H?O hydrogen bonds, and intermolecular C?H?? interactions are also present.
N-[(4-Amino-5-sulfanylidene-4,5-dihydro-1H-1,2,4-triazol-3-yl)methyl] -4-methylbenzamide
(2010) Fun, H.-K.; Yeap, C.S.; Mange, Y.; Isloor, A.M.; Hegde, C.
In the title compound, C11H13N5OS, the dihedral angle between the triazole ring and the benzene ring is 84.21 (7) . The amino group adopts a pyramidal configuration. An intra-molecular N - H?O hydrogen bond stabilizes the molecular structure and generates an S(8) ring. In the crystal, molecules are linked by inter-molecular N - H?O, N - H?S, N - H?N and C - H?S hydrogen bonds into layers lying parallel to the bc plane. The crystal structure is further stabilized by aromatic ?-? stacking interactions [centroid-centroid distance = 3.3330 (7) ].
N-[(4-Amino-5-sulfanylidene-4,5-dihydro-1H-1,2,4-triazol-3-yl)methyl] -4-methylbenzamide
(2010) Fun, H.-K.; Yeap, C.S.; Mange, Y.; Isloor, A.M.; Hegde, C.
In the title compound, C11H13N5OS, the dihedral angle between the triazole ring and the benzene ring is 84.21 (7)°. The amino group adopts a pyramidal configuration. An intra-molecular N - H?O hydrogen bond stabilizes the molecular structure and generates an S(8) ring. In the crystal, molecules are linked by inter-molecular N - H?O, N - H?S, N - H?N and C - H?S hydrogen bonds into layers lying parallel to the bc plane. The crystal structure is further stabilized by aromatic ?-? stacking interactions [centroid-centroid distance = 3.3330 (7) Å].
New CPS-PPEES blend membranes for CaCl2 and NaCl rejection
(2012) Hegde, C.; Isloor, A.M.; Padaki, M.; Ismail, A.F.; J, L.W.
Carboxylated polysulfone (CPS), poly (1,4-phenylene ether ethersulfone) (PPEES), membranes were prepared and used for the separation of NaCl and CaCl2 in efficient way with less energy consumption. In this work, nanofiltration and reverse osmosis membranes were employed to the salt rejection behavior of the different salt solutions. The influence of applied pressure (1-12 bar), on the membrane performance was assessed. In CM series of membranes, CM1 showed maximum of 97% water uptake and 36% water swelling, whereas, CM4 showed 75% water uptake and 28% water swelling. In RCM series, RCM1 showed 85% water uptake and 32% water swelling whereas, in RCM4 it was 68% for water uptake and 20% for water swelling. Conclusively reverse osmosis membranes gave better rejection whereas nanofiltration membrane showed enhanced flux. CM1 showed 58% of rejection with 12L/(m2h) flux and RCM1 showed 55% of rejection with 15L/(m2h) flux for 0.1wt.% NaCl solution. Whereas, in 0.1wt.% CaCl22 solution, membrane CM11 showed 78% of rejection with 12L/(m2h) flux and RCM1 showed 63% rejection with flux of 9L/(m2h).
New CPS-PPEES blend membranes for CaCl2 and NaCl rejection
(Techno Press technop2@chollian.net, 2012) Hegde, C.; Isloor, A.M.; Padaki, M.; A.F., A.F.; Lau, L.W.
Carboxylated polysulfone (CPS), poly (1,4-phenylene ether ethersulfone) (PPEES), membranes were prepared and used for the separation of NaCl and CaCl2 in efficient way with less energy consumption. In this work, nanofiltration and reverse osmosis membranes were employed to the salt rejection behavior of the different salt solutions. The influence of applied pressure (1-12 bar), on the membrane performance was assessed. In CM series of membranes, CM1 showed maximum of 97% water uptake and 36% water swelling, whereas, CM4 showed 75% water uptake and 28% water swelling. In RCM series, RCM1 showed 85% water uptake and 32% water swelling whereas, in RCM4 it was 68% for water uptake and 20% for water swelling. Conclusively reverse osmosis membranes gave better rejection whereas nanofiltration membrane showed enhanced flux. CM1 showed 58% of rejection with 12L/(m2h) flux and RCM1 showed 55% of rejection with 15L/(m2h) flux for 0.1wt.% NaCl solution. Whereas, in 0.1wt.% CaCl22 solution, membrane CM11 showed 78% of rejection with 12L/(m2h) flux and RCM1 showed 63% rejection with flux of 9L/(m2h).
Prediction of peak particle velocity using multi regression analysis: case studies
(2017) Ram Chandar, K.; Sastry, V.R.; Hegde, C.; Shreedharan, S.
Ground vibrations produced from blasting operations cause structural vibrations, which may weaken structure if it occurs at the resonant frequency. Measurable parameters associated with ground vibrations are peak particle velocity (PPV), amplitude and dominant frequency (frequency of highest PPV amongst translational, vertical and horizontal vibrations). In this paper, an attempt is made to correlate measurable parameters associated with ground vibrations with scaled distance. Using the correlated data, it was found that a predictor equation can be determined for the amplitude and PPV, but not for dominant frequency as it is dynamic and depends upon infinitesimal changes that occur within a number of other parameters. Another analysis of the same is made using multiple linear regression analysis. This included predicting the PPV using scaled distance, maximum charge per delay, amplitude as predictors. A considerable improvement is seen in the prediction on adding the interaction of the predictors in multiple regressions. A comparison of different combination of predictors is made so as to assess the best combination giving the best R2 value for the given mine. Frequency is also plotted using the aforementioned method. However, it was found that the dominant frequency cannot be predicted with high accuracy even with this method. 2016 Informa UK Limited, trading as Taylor & Francis Group.
Prediction of peak particle velocity using multi regression analysis: case studies
(Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2017) Ram Chandar, K.; Sastry, V.R.; Hegde, C.; Shreedharan, S.
Ground vibrations produced from blasting operations cause structural vibrations, which may weaken structure if it occurs at the resonant frequency. Measurable parameters associated with ground vibrations are peak particle velocity (PPV), amplitude and dominant frequency (frequency of highest PPV amongst translational, vertical and horizontal vibrations). In this paper, an attempt is made to correlate measurable parameters associated with ground vibrations with scaled distance. Using the correlated data, it was found that a predictor equation can be determined for the amplitude and PPV, but not for dominant frequency as it is dynamic and depends upon infinitesimal changes that occur within a number of other parameters. Another analysis of the same is made using multiple linear regression analysis. This included predicting the PPV using scaled distance, maximum charge per delay, amplitude as predictors. A considerable improvement is seen in the prediction on adding the interaction of the predictors in multiple regressions. A comparison of different combination of predictors is made so as to assess the best combination giving the best R2 value for the given mine. Frequency is also plotted using the aforementioned method. However, it was found that the dominant frequency cannot be predicted with high accuracy even with this method. © 2016 Informa UK Limited, trading as Taylor & Francis Group.
Synthesis and Characterization of PVDF/Graphene Nanocomposite Membrane for Water Treatment Applications
(Trans Tech Publications Ltd, 2022) Rao, S.; Avinash, A.; As, S.; Hegde, C.; Isloor, A.M.; Vinayak, V.R.
Membrane technology advancement has gained momentous consideration around the globe because of their appealing highlights, such as effectiveness, low expenses, and effective solutions for longstanding issues in alchemical industries. This study expected to incorporate graphene nanoparticles into Polyvinylidene difluoride (PVDF) to form nanofiltration (NF) layers using DMF (Dimethyl formamide) as solvent via DIPS (diffusion induced phase separation) technique. PVDF polymer membrane performances with varied percent (1 – 6% wt.) of graphene concentrations are studied with Infrared spectral, water uptake, water contact angle, and ion rejection measurements. Scanning electron microscope (SEM) analysis showed that the pore size is often regulated by incorporating graphene nanoparticles (80-90 nm) as compared to PVDF membranes. The PVDF membranes exhibited a relative increase in the contact angle from PVDF to PVDF-G6%, i.e., 50.3° to 63.46 ± .3, thus, showing a relative increase in hydrophobicity. The higher percent of graphene (> 6% by wt.) results in nano-particle accumulation that showed the performances of PVDF/graphene rejection possessing relatively the same results. The results confirmed that the prepared membranes possess an excellent ability to treat wastewater. © 2022 Trans Tech Publications Ltd, Switzerland.
Synthesis and desalination performance of Ar+-N+ irradiated polysulfone based new NF membrane
(2011) Hegde, C.; Isloor, A.M.; Padaki, M.; Wanichapichart, P.; Liangdeng, Y.
In the last few years, membrane technology has gained more attention from polymer chemists throughout the globe. Nowadays, surface modification of membrane is very useful in biotechnology and food science. In the present investigation, we have synthesized polysulfone based composite nanofiltration (NF) membranes, and characterized these membranes by FT-IR, SEM and membrane performance studies. Surface plasma treatment was carried out by irradiation with argon and nitrogen beams in suitable conditions. It was observed that nitrogen beam caused surface roughness that was more severe than the Ar beam. After irradiation, water contact angle was slightly increased. For pure water permeability, flux increased linearly with the operating pressure. However, for the salt solution, the flux was decreased marginally and salt rejection increased after irradiation due to surface modification. The modification effect was characterized in terms of contact angle, AFM employed roughness measurement and dielectric property. It revealed that irradiated NF membranes showed higher salt rejection and lower flux as compared to the nonmodified membranes. Accordingly, the roughness of the membrane surface intensively affected the performance of RO membrane. 2010 Elsevier B.V.
Synthesis and desalination performance of Ar+-N+ irradiated polysulfone based new NF membrane
(2011) Hegde, C.; Isloor, A.M.; Padaki, M.; Wanichapichart, P.; Liangdeng, Y.
In the last few years, membrane technology has gained more attention from polymer chemists throughout the globe. Nowadays, surface modification of membrane is very useful in biotechnology and food science. In the present investigation, we have synthesized polysulfone based composite nanofiltration (NF) membranes, and characterized these membranes by FT-IR, SEM and membrane performance studies. Surface plasma treatment was carried out by irradiation with argon and nitrogen beams in suitable conditions. It was observed that nitrogen beam caused surface roughness that was more severe than the Ar beam. After irradiation, water contact angle was slightly increased. For pure water permeability, flux increased linearly with the operating pressure. However, for the salt solution, the flux was decreased marginally and salt rejection increased after irradiation due to surface modification. The modification effect was characterized in terms of contact angle, AFM employed roughness measurement and dielectric property. It revealed that irradiated NF membranes showed higher salt rejection and lower flux as compared to the nonmodified membranes. Accordingly, the roughness of the membrane surface intensively affected the performance of RO membrane. © 2010 Elsevier B.V.
Synthesis and performance characterization of PS-PPEES nanoporous membranes with nonwoven porous support
(2013) Hegde, C.; Isloor, A.M.; Padaki, M.; Fun, H.-K.
The present work describes about the synthesis and characterization of Polysulfone blend nanoporous membrane with nonwoven support. This Nonwoven support provides mechanical strength to membrane while filtration process and minimizes membrane fouling. Hence it helps in better membrane performance in terms of salt rejection, improved flux, thermal stability and fairly increases in proton conductivity. In this work we have used K.C.270 nonwoven material consisting of fine polyester fibers and has a thickness of below 110. ?m. 2011.
Synthesis and performance characterization of PS-PPEES nanoporous membranes with nonwoven porous support
(2013) Hegde, C.; Isloor, A.M.; Padaki, M.; Fun, H.-K.
The present work describes about the synthesis and characterization of Polysulfone blend nanoporous membrane with nonwoven support. This Nonwoven support provides mechanical strength to membrane while filtration process and minimizes membrane fouling. Hence it helps in better membrane performance in terms of salt rejection, improved flux, thermal stability and fairly increases in proton conductivity. In this work we have used K.C.270 nonwoven material consisting of fine polyester fibers and has a thickness of below 110. ?m. © 2011.
Synthesis, characterization & impedance studies of some new nano filtration membranes
(2010) Padaki, M.; Hegde, C.; Isloor, A.M.
In the recent years membrane technology has gained significant attention from polymer chemists all around the world due to their attractive features such as efficiency, low costs, low energy costs and as effective solutions to longstanding problems in the chemical industries. Membrane technologies have been widely applied in the separation of liquids and even gases. Many separation problems can be solved economically by nanofiltration alone or in combination with other separation processes. This study aimed to synthesize polysulfone based nanofiltration membranes using DIPS (diffusion induced phase separation) technique. Newly synthesized polymer membranes were subjected to Infra red spectral and water uptake studies. Membranes were also characterized using electrochemical spectroscopy for their proton conducting property. Their surface morphology is visualized by SEM. (2010) Trans Tech Publications.