Browsing by Author "Murthy, C.S.N."

Now showing 1 - 20 of 55

A review study of thermal conductivity and influencing physico-mechanical properties of rocks
(Inderscience Publishers, 2023) Dileep, G.; Tripathi, A.K.; Murthy, C.S.N.; Pal, S.K.
Geothermal exploration and heat flow studies rely heavily on rock's thermal conductivity, and it controls the subsurface temperature distribution. A broad study of rock thermal properties has become progressively indispensable for geotechnical, civil, mining, and tunnel engineers. The thermal properties of rocks are essential to the ground modification technique of geothermal heat pumps, environmentally conscious projects like dumping high-level nuclear waste in underground sites, and a wide range of engineering projects. The steady-state technique is commonly employed for homogeneous materials, providing a more precise thermal conductivity value despite longer testing times. Conversely, the transient technique is preferred for heterogeneous materials with moisture content, considering this factor but requiring multiple tests to achieve accurate results. This paper explores the predominant approaches used to measure rock thermal conductivity and identify the factors that influence it. Additionally, researchers present a generic equation for predicting the thermal conductivity of rocks using data they have gathered. According to this article, the thermal conductivity of rocks is influenced by several factors such as porosity, density, pressure, moisture content, variations in mineral composition, temperature, and more. © 2023 Inderscience Enterprises Ltd.
A Switched-Capacitor Based Nine-level Boost Inverter Circuit for Mining Applications
(Institute of Electrical and Electronics Engineers Inc., 2022) Prudhvi Krishna, B.N.V.V.; Kunar, B.M.; Murthy, C.S.N.
A dual boost nine-level inverter for mining applications is proposed in this work. Capacitors are used as virtual sources to boost the voltage magnitude and increase the levels. Additionally, the proposed MLI circuit inherits benefits such as self-balancing capacitors, less blocking voltage, and fewer components. A simple PD-PWM scheme is used to generate gating signals. Circuit portrayal, operating principle, modulation, and capacitor voltage ripples are studied. MATLAB software is used to carry out simulations, and the obtained outcomes prove the boosting ability under different loading circumstances. A detailed comparative review is conducted with other recent SCMLIs to illustrate the superiorities of the proposed circuit. Â© 2022 IEEE.
An adaptive modeling for bifacial solar module levelized cost and performance analysis for mining application
(John Wiley and Sons Ltd, 2024) Shiva Kumar, B.S.; Kunar, B.M.; Murthy, C.S.N.
Power density and efficiency typically dominate design approaches for power electronics. However, cost optimality is in no way guaranteed by these strategies. A design framework that minimizes the (i) levelized cost of electricity (LCOE), (ii) collection of light, and (iii) irradiance of the generation system is proposed as a solution to this flaw. From an improvement of the swarm behavior optimization model to get a minimum LCOE of solar panel, we design to optimize height, tilt angle, azimuth angle, and some parameters to solve the objective function and LCOE improvement problem to obtain the optimal design problem. In adaptive salp swarm optimization (ASSO), this change's proposed model producer swarm behavior is regarded as an adaptive process that keeps the algorithm from prematurely converging during exploration. The proposed algorithm's performance was confirmed using benchmark test functions, and the results were compared with those of the salp swarm optimization (SSO) and other efficient optimization algorithms. LCOE condition as far as “land-related cost” and “module-related cost” demonstrates that the optimal design of bifacial farms is determined by the interaction of these parameters. This proposed model can be used to evaluate visibility on building surfaces that are suitable for mining applications like crushing. Experimentation results show Minimum LCOE AS 0.05 (€/Kw)minimum irradiance and collection light as 336.23(w/m2) and 83.02%n proposed framework model. The swarm optimization method is contrasted with the optimal parameters derived from a conventional solver. © 2023 John Wiley & Sons Ltd.
An economic analysis of environmental pollution and health - a case study of Bellary-Hospet sector
(2012) Thimmaiah, S.A.; Ravi, D.R.; Rao, Y.V.; Murthy, C.S.N.
The Earth's natural ecosystem is the basis for our life-supporting system and provides marketable goods to human and other living organisms. The natural environment has always been exploited to fulfill human needs. The green revolution and industrial revolution has caused serious threat to sustainable development for both developed and developing countries. The degradation of air, water and land has directly affected the livelihood and human health. The environmental damage increases, as the economic activity increases, in view of the fact that the association between economy and the environment are multiple, complex and important. Mining is one such activity, which significantly results in the degradation of the environment, apart from generating huge economy to the country. Hence, the identification and quantification of socio economic impact of environmental pollution caused due to increased mining activity is necessary in the broader economic analysis. The present study is envisaged with the objective to identify and evaluate the impacts of mining activity on Social, Economical and Environmental Aspects of the area and to measure its economic burden on the affected people. The ambient air quality in the selected stations of study area reveals that, the increase in iron ore production has significantly resulted in the deterioration of air quality. High particulate matter to an extent of 310 ?g/nm3 in case of SPM concentration and 160 ?g/nm3 in case of RSPM. The health data collected from the respondents have revealed, significantly more number of respondents who are suffering from dust allergy, skin allergy in the study area, where there are mines and are working as workers in those mines, contributing for higher health cost incurred through treatment. © 2012 CAFET-INNOVA TECHNICAL SOCIETY.
ANN model for prediction of bit–rock interface temperature during rotary drilling of limestone using embedded thermocouple technique
(Springer Science and Business Media B.V., 2020) Vijay Kumar, V.K.; Kunar, B.M.; Murthy, C.S.N.
In the present work, an artificial neural network (ANN) model has been developed to predict the bit–rock interface temperature using a newly fabricated grounded K-type thermocouple (range 0–1250 °C) during rotary drilling in a CNC vertical machining center. The data have been taken from experimental observation using an embedded thermocouple technique in the laboratory at room temperature (28 °C) using a masonry drill bit. The observations were made using four different operational conditions, namely drill bit diameter (6, 8, 10, 12 and 16 mm), spindle speed (250, 300, 350, 400 and 450 rpm), rate of penetration (2, 4, 6, 8 and 10 mm min?1) and depth (6, 14, 22 and 30 mm). The ANN has been developed based on the multi layer perceptron neural network (MLPNN) with four different input parameters. A Levenberg–Marquardt (LM) algorithm with feed-forward and backward propagation has been used in this model. The predicted value of the bit–rock interface temperature with the highest R2 value provides a satisfactory result with the experimental data. The training value of RMSE is 1.2127, MAPE is 0.0196 and R2 is 0.9960, while the testing value of RMSE is 1.2770, MAPE is 0.0170 and R2 is 0.9978. The ANN model shows that the proposed MLPNN model successfully predicts the bit–rock interface temperature during the rotary drilling of limestone. © 2019, Akadémiai Kiadó, Budapest, Hungary.
ANN Models for Prediction of Sound and Penetration Rate in Percussive Drilling
(Springer India sanjiv.goswami@springer.co.in, 2015) Kivade, S.B.; Murthy, C.S.N.; Vardhan, H.
In the recent years, new techniques such as; Artificial Neural Network (ANN) were employed for developing of the predictive models to estimate the needed parameters. Soft computing techniques are now being used as alternate statistical tool. In this study, ANN models were developed to predict rock properties of sedimentary rock, by using penetration and sound level produced during percussive drilling. The data generated in the laboratory investigation was utilized for the development of ANN models for predicting rock properties like, uniaxial compressive strength, abrasivity, tensile strength, and Schmidt rebound number using air pressure, thrust, bit diameter, penetration rate and sound level. Further, ANN models were also developed for predicting penetration rate and sound level using air pressure, thrust, bit diameter and rock properties as input parameters. The constructed models were checked using various prediction performance indices. ANN models were more acceptable for predicting rock properties. © 2015, The Institution of Engineers (India).
Artificial neural network for prediction of rock properties using acoustic frequencies recorded during rock drilling operations
(Springer Science and Business Media Deutschland GmbH, 2022) Vijaya Kumar, C.V.; Vardhan, H.; Murthy, C.S.N.
Determining properties of rocks in rock mechanics/engineering applications such as underground tunnelling, slope stability, foundations, dam design and rock blasting is often difficult due to the requirements of high quality of core rock samples and accurate test apparatus. Prediction of the geomechanical properties of rock material has been an area of interest for rock mechanics for several years now. Nowadays, soft computing methods are used as a powerful tool to estimate the rock properties, cost and duration of the project. This has led to a lack of necessity to develop a model to predict rock properties in the field of rock mechanics. ANN (artificial neural network) models were developed to predict geomechanical properties of the sedimentary rock types using dominant frequencies of an acoustic signal during rock drilling operations. A set of experimental drilling operations test conditions around 875 were used as input parameters including drill bit spindle speeds (rpm), drill bit penetration rates (mm/min), drill bit diameters (mm) and dominant frequencies of the acoustic signal (Hz). The response (output) was uniaxial compressive strength (UCS), Brazilian tensile strength (BTS), density (ρ) and abrasivity (%). The developed models were checked using various performance indices. The results from the analysis show that the suggested ANN model approach is efficient, fits the data and accurately reflects the experimental results. The ANN models predicted physico-mechanical rock properties through the dominant frequency of acoustic signals during rock drilling operations. © 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG part of Springer Nature.
Assessment and Prediction of Specific Energy Using Rock Brittleness in Rock Cutting
(Springer Nature, 2020) Raghavan, V.; Murthy, C.S.N.
In this study, we used picks with point attack angles of 45Â°, 50Â°, 55Â°, and 65Â° and 45Â°, 55Â°, and 65Â° attack angles in rock cutting experiments. The main objective is to estimate specific energy during the cutting process based on rock brittleness and study the influence of attack angle on specific energy. From the experimental data, we compared the obtained results using multiple linear regressions and ANOVA to predict the specific energy and found that the model developed were statistically significant. R2 of the brittleness B4 is 0.79 in comparision with R2 of density, UCS, BTS and abrasivity as 0.74, 0.83, 0.84 and 0.73. Specific energy not only be predicted from density, UCS, BTS, abrasivity, it can also be predicted using rock brittleness. Â© 2020, Springer Nature Switzerland AG.
Assessment of noise and effect of thrust on penetration rate in percussive drilling
(2011) Kivade, S.B.; Murthy, C.S.N.; Vardhan, H.
Rock drills are a major source of noise in the mining industry, with levels reaching as high as 115 dbA at the operator's ear. Noise of this amplitude has long been recognized as a serious health hazard. The two major noise sources in pneumatic rock drills are exhaust air and impact of the piston against the drill rod shank. The exhausted compressed air produces noise because it is released at a relatively high pressure and in bursts or pulses. While the impact of the piston against the shank causes vibrations in the drill rod and in different parts of the drill body which then radiate noise. Mufflers can reduce the noise to the order of 105 dbA, at which level the drill rod vibrations become the dominant noise source. The rock types selected for the present study are basalt, gabro granite, pink granite and lime stone. The range of applied thrust varies between 10 kg to 100 kg. All the holes were drilled for a fixed time of one minute and penetration rates were obtained. It was observed that very low thrust results in low penetration rates but on the other hand, even very high thrusts do not produce high penetration rates at high operating air pressures. Optimum thrusts were obtained for each rock type experimentally. This paper deals in detail effect of applied thrust on the penetration rate and sound level of a conventional percussive drill.
Comparison of the particle size distribution in marble and granite rock samples subjected to ball milling process
(2019) Kunar, B.M.; Murthy, C.S.N.; Rao, B.K.
Rock particle size has a very important significance in the mining industry, starting from blasting till the mineral processing. The present study was carried out to understand the particle size distribution in various sieves after conducting the ball milling process. The time of the grinding process was varied at different intervals. It was observed that 80% of the particles of both granite and marble rock samples passed through the 4800 ?m sieve when subjected to grinding time of 40 minutes. Also, it was observed the number of particles that were retained in the smallest sieve of <75 ?m was higher in the case of granite sample when compared to a marble sample. Copyright � 2019 by SME.
Comparison of the particle size distribution in marble and granite rock samples subjected to ball milling process
(Society for Mining, Metallurgy and Exploration theng@smenet.org 12999 E Adam Aircraft Circle Englewood,Colorado 80112 Colorado, 2019) Kunar, B.M.; Murthy, C.S.N.; Rao, B.K.
Rock particle size has a very important significance in the mining industry, starting from blasting till the mineral processing. The present study was carried out to understand the particle size distribution in various sieves after conducting the ball milling process. The time of the grinding process was varied at different intervals. It was observed that 80% of the particles of both granite and marble rock samples passed through the 4800 Î¼m sieve when subjected to grinding time of 40 minutes. Also, it was observed the number of particles that were retained in the smallest sieve of <75 Î¼m was higher in the case of granite sample when compared to a marble sample. Â© Â© 2019 by SME.
Correlating mineralogical composition, resistivity, and mechanical properties of limestone using response surface methodology (RSM)
(Springer Nature, 2025) Varalakshmi, P.; Kumar Reddy, S.K.; Murthy, C.S.N.
Response Surface Methodology (RSM) is used in this study to predict the interaction of mechanical characteristics, electrical resistivity, and mineralogical composition in limestone. For this purpose, laboratory experiments combined with petrographic, SEM, and resistivity measurements were carried out, and the results were statistically modeled using RSM. Microcrystalline calcite with trace impurities including SiO? and Fe2O?, which affect mechanical behavior and resistivity, was found to be the predominant mineral in petrographic and SEM investigations. Higher porosity (> 4.9%) or extreme resistivity values reduce the Indirect Tensile Strength (ITS), while moderate resistivity (37.5–42.5 ?m) and low porosity (< 4.7%) maximize ITS, according to a quadratic RSM model. Particularly when paired with increased porosity, abrasion resistance shown a less significant but still noticeable effect. According to the findings, porosity is the main factor causing strength loss, and brittleness is further modulated by mineralogy (such as the amount of quartz). The study provides a framework linking resistivity, porosity, and mineralogy with mechanical performance, which can guide limestone selection and processing in geotechnical and construction applications. © Indian National Science Academy 2025.
Corrosion mitigation of the oil well steels using organic inhibitors-A review
(2012) Puthalath, P.; Surendranathan, A.O.; Murthy, C.S.N.
Oil well stimulation, usually done with hot solutions of hydrochloric acid, may induce severe corrosion attack on production tubing, downhole tools and casing. Inorganic, organic and combinations of acids along with surfactants are used in a variety of well stimulation treatments. To reduce the aggressive attack of the acid on tubing and casing materials (N80 steel), inhibitors are added to the acid solution during the acidifying process. The inhibition in oil and gas field is more complicated and requires special eco-friendly inhibitors depending on the area of application such as in refineries, wells, recovery units, pipelines etc. Aggressive gases such as H2S, CO2, and organic acids complicate the problem of inhibition in wells. Various factors have to be considered while dealing with corrosion problems of oil and gas industry. The type of reservoir rocks, the acids used for stimulation, the oil well equipments such as tubings and casings and the operating conditions are some of the important factors that affect the corrosivity. Each and every case has to be considered in its totality before a decision is made on the proper materials. No particular material is the cure for all the evils of corrosion. It is imperative to the field operators, pipeline engineers, designers to have corrosion awareness concerning the oil and gas industries in their day to day activities to compact and mitigate corrosion. This work is an attempt in this direction.
Effect of shading on PV panel technology
(2018) Tripathi, A.K.; Murthy, C.S.N.
Solar photovoltaic energy conversion has gained much attention nowadays. The performance of solar photovoltaic system mainly depends on the solar radiation falling on the panel surface. Shading across the panel surface is the main cause for the degradation of its performance. It was found that due to 25% shading strength in mono crystalline PV panel the reduction in short circuit current and maximum power output was respectively 40.72% and 41.40%. Similarly, the reduction in short circuit current and maximum power output was 60.86% and 61.80%, respectively for poly crystalline panel. Under the same level of shading the monocrystalline PV panel shows less reduction in its performance when compared to poly crystalline PV panel. � 2017 IEEE.
Effect of shading on PV panel technology
(Institute of Electrical and Electronics Engineers Inc., 2018) Tripathi, A.K.; Murthy, C.S.N.
Solar photovoltaic energy conversion has gained much attention nowadays. The performance of solar photovoltaic system mainly depends on the solar radiation falling on the panel surface. Shading across the panel surface is the main cause for the degradation of its performance. It was found that due to 25% shading strength in mono crystalline PV panel the reduction in short circuit current and maximum power output was respectively 40.72% and 41.40%. Similarly, the reduction in short circuit current and maximum power output was 60.86% and 61.80%, respectively for poly crystalline panel. Under the same level of shading the monocrystalline PV panel shows less reduction in its performance when compared to poly crystalline PV panel. Â© 2017 IEEE.
Effect of thermal response on physical properties during drilling operations-A case study
(2018) Vijay, Kumar, S.; Murthy, C.S.N.; Kunar, B.M.
The temperature induced or generated during deep hole drilling operations is due to the heat generated between the interface of work piece surface and the tool surface. Several research study have been conducted to predict the temperature involved while drilling process as a predominant functions of many parameters like feed rate, torque, depth of cut etc. Similarly many experimental procedures have been conducted by several researchers to measure temperature directly by using thermocouples, infrared measurement, pyrometer, and thermisters etc. There is no precise experimental method is available to measure analytical value of energy, power, heat flux etc, while drilling process. The temperature rigma depends on material compositions and physical properties. This paper presents the influence of temperature on physical properties of some study samples during drilling operations. � 2017 Elsevier Ltd.
Estimating rock properties using sound signal dominant frequencies during diamond core drilling operations
(Chinese Academy of Sciences rockgeotech@whrsm.ac.cn, 2019) Vijaya Kumar, C.V.; Vardhan, H.; Murthy, C.S.N.; Karmakar, N.C.
In many engineering applications such as mining, geotechnical and petroleum industries, drilling operation is widely used. The drilling operation produces sound by-product, which could be helpful for preliminary estimation of the rock properties. Nevertheless, determination of rock properties is very difficult by the conventional methods in terms of high accuracy, and thus it is expensive and time-consuming. In this context, a new technique was developed based on the estimation of rock properties using dominant frequencies from sound pressure level generated during diamond core drilling operations. First, sound pressure level was recorded and sound signals of these sound frequencies were analyzed using fast Fourier transform (FFT). Rock drilling experiments were performed on five different types of rock samples using computer numerical control (CNC) drilling machine BMV 45 T20. Using simple linear regression analysis, mathematical equations were developed for various rock properties, i.e. uniaxial compressive strength, Brazilian tensile strength, density, and dominant frequencies of sound pressure level. The developed models can be utilized at early stage of design to predict rock properties. © 2019 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences
Evolution of the Probability Distribution Function of Shovel â€“ Dumper Combination in Opencast Coal Mine Using ANN and RWB
(Springer Nature, 2020) N. S., N.S.; Choudhary, R.P.; Murthy, C.S.N.
This article presents a new analytic calculation for the shovel â€“ dumper combination in opencast coal mine evolution of the one and two galaxy probability distribution function (PDF). To develop a nonparametric PDF for a combination of shovel and dumper in a opencast coal mine, the historical breakdown data such as time between failure (TBF) of a shovel and dumpers were collected from the mine. Based on the collected TBF, Weibull parameters such as the shape parameter (Î²), scale parameter (Î·) and location parameter (Î³) were calculated under the K-S test (Kolmogorovâ€“Smirnov test). A Weibull distribution model has been developed to obtain the one and two galaxy probability distribution function (PDF) for a collected failure data of shovel-dumper system using Reliability Isograph Workbench (RWB). Also, Artificial Neural Network (ANN) model has been developed to predict the PDF for the same shovel-dumper system and compared with the actual obtained value of Reliability Isograph Workbench (RWB). It was found that the values of RMSE and R2 were 0.00068 & 0.9465 for PDF. The statistical results showed that the proposed Reliability Isograph Workbench and ANN model successfully predicts PDF for the shovel-dumper system. Â© 2020, Springer Nature Switzerland AG.
Evolution of the probability distribution function of shovel–dumper combination in open cast limestone mine using RWB and ANN: a case study
(Springer Science and Business Media Deutschland GmbH, 2019) Kumar, N.S.H.; Choudhary, R.P.; Murthy, C.S.N.
This newsletter affords a new analytic calculation for the shovel–dumper combination in open cast limestone mine evolution of the only and two galaxy probability density function (PDF). To broaden a nonparametric PDF for a combination of shovel and dumper in an open cast limestone mine, the ancient failure statistics which includes time between failure (TBF) of a shovel and dumpers had been accumulated from the mine. Primarily based on the collected TBF, Weibull parameters which include the shape parameter (?), scale parameter (?), and location parameter (?) have been calculated under the K–S test (Kolmogorov–Smirnov test) using Isograph Reliability Workbench (RWB). In addition, the artificial neural network (ANN) version has been developed to predict the PDF for the same shovel–dumper system and compared with the real acquired fee of RWB. It was found that the values of RMSC and R2 had been 5.96e?5 and 0.999 for PDF. The statistical effects showed that the proposed Reliability Isograph Workbench and PDF version correctly predicts PDF for the shovel–dumper system. © 2019, Springer Nature Switzerland AG.
Experimental, simulation and a case study on electrical energy consumption in mine drive haulage system
(Institute of Electrical and Electronics Engineers Inc., 2015) Moger, G.D.; Murthy, C.S.N.; Yaragatti, R.Y.
The experimental investigation study on energy consumption of fabricated 3hp mine drive haulage system is presented. The performance analysis of energy consumption based on existing mine drive haulage system of underground coal mine and experimental set-up is prepared in the laboratory for a 3-hp wound rotor induction motor. The experimental and a case study results are simulated using MATLAB /simulink model and the compared results are presented in this paper. Â© 2015 IEEE.