Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
8 results
Search Results
Item Metal- Organic Framework Containing Polymeric Membranes for Fuel Cells(CRC Press, 2023) Shivarama, B.; Isloor, A.M.; Murthy, C.S.; Prabhu, B.; A.F., A.F.Fuel cells have attracted immense attention due to their application in green energy initiatives. The proton exchange membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs) are the two classes of fuel cells that work with polymer membrane technology. The pristine membranes of different polymeric materials lack the necessary properties to be called high-performing proton exchange membranes. However, the addition of porous materials like metal organic frameworks (MOFs) has brought substantial improvements regarding their proton conductivity, chemical, mechanical, and thermal steadiness. There have also been significant improvements in terms of methanol permeability. Metal-organic frameworks (MOFs) have fascinated scientists due to their porous structure, capacity to hold molecules, high selectivity, tunable pore size, and ability to undergo modifications in functionalization or post-synthetic modifications. Researchers have focused on developing composite membranes as proton exchange membranes (PEMs) for fuel cells (FCs). MOF-incorporated composite membranes have exhibited tremendous potential and significant future material applications. This chapter provides an insight into the development of MOF-incorporated composite membranes as PEMs for FCs. © 2024 selection and editorial matter, Anil Kumar Pabby; S. Ranil Wickramasinghe; and Ana- Maria Sastre; individual chapters, the contributors.Item Experimental investigation and statistical analysis of operational parameters on temperature rise in rock drilling(International Information and Engineering Technology Association info@iieta.org, 2018) Vijay Kumar, V.K.; Kunar, B.M.; Murthy, C.S.Heat generated during rock drilling, due to friction at the bit-rock interface. Due to which temperature increases, which can influence the thermal stress and subsequent rock failure. In this paper, an attempt is made to present results related to the temperature assessment during rotary drilling of rocks on medium-grained sandstone under controlled laboratory conditions. The experiments were conducted by using embedded thermocouple technique, the thermocouple was placed at a distance of 0.5mm (horizontal) from the bit-rock interface. The influence of operational parameters, i.e., the diameter of the drill bit, spindle speed and rate of penetration of rise in temperature was studied using multiple regression and data analysis was carried out using analysis of variance (ANOVA). The temperature was measured by using embedded thermocouple technique at a depth of 6mm, 14mm, 22mm and 30mm respectively. Regression models were developed for the prediction of temperature at the bit-rock interface. It was observed that the increase in temperature for medium-grained sandstone was from 49 0 C to 74 0 C (51.08%) with an increase in the diameter of the drill bit, spindle speed and rate of penetration. © 2018 International Information and Engineering Technology Association.Item Fuzzy-FMEA risk evaluation approach for LHD machine-A case study(Central Mining Institute in Katowice gzyl@gig.katowice.pl, 2019) Balaraju, J.; Govinda Raj, M.; Murthy, C.S.Improvement of productivity has become an important goal for mining industries in order to meet the expected targets of production and increased price competitiveness. Productivity can be improved in different ways. The effective utilization of men and machinery is one such way. Equipment is prone to numerous unexpected potential failures during its operation. Failure Mode and Effect Analysis (FMEA) is one of the suitable techniques of reliability modeling used to investigate the failure behavior of a complex system. In conventional FMEA, the risk level of failures, a ranking of failures and prioritization of necessary actions is made on the basis of estimated Risk Priority Number (RPN). While this approach is easy and uncomplicated, there are a few flaws in acquiring the best approximation of the failure. The estimation of RPN is made by multiplying the Severity (S), Occurrence (O) and Detection (D) alone and irrespective of the degree of importance of each input. Hence, a new risk management approach known as the Fuzzy rule base interface system was proposed in this research in order to mitigate the failures. Fuzzy FMEA is designed in order to acquire the highest Fuzzy RPN value which will be used as the focus of enhancements to reduce the probability of occurrence of some kind of failure for a second time. This study focused on the Root Cause Analysis (RCA) of underground mining machinery such as Load-Haul-Dumper (LHD). 16 potential risks of various sub-system breakdowns were identified in Fuzzy FMEA. The highest value of RPN 168 (for potential failure mode-F9) was obtained for the electrical subsystem (SSE), as was the highest FRPN 117 (F9). There is a difference between the RPN and FRPN values. The FRPN value is obtained from Fuzzy field generation with consideration of the degree of importance of the given input data. In addition, the recommendations were made based on the analysis to reduce the uneven occurrence of failures. © 2019 Central Mining InstituteItem Application ANN Tool for Validation of LHD Machine Performance Characteristics(Springer, 2020) Balaraju, B.; Raj, G.R.; Murthy, C.S.Survival of industries has become more critical in the present global competitive business environment unless they produce their projected production levels. The accomplishment of this can be possible only by maintaining the men and machinery in an efficient and effective manner. Hence, it is more essential to estimate the performance of utilized equipment for reaching/achieving future goals. The present study focuses on the estimation of underground mining machinery such as the load–haul–dump machine performance characteristics using ‘Isograph Reliability Workbench 13.0’ software. The allocation of best-fit/goodness-of-fit distribution was made by utilizing the Kolmogorov–Smirnov test (K–S) test. The parameters were recorded based on the best-fitted results using the maximum likelihood estimate test. Further, a feed-forward-back-propagation artificial neural network (ANN) tool has been used to develop the models of reliability, availability and preventive maintenance time intervals. The number of neurons was selected with the Levenberg–Marquardt learning algorithm in the hidden layer as the optimal value. The output responses were predicted corresponding to the optimal values. Further, an attempt has been made to validate the computed results with ANN predicted responses. The recommendations are suggested to the industry based on the results for the improvement of system performance. © 2020, The Institution of Engineers (India).Item Measurement of bit-rock interface temperature and wear rate of the tungsten carbide drill bit during rotary drilling(Tsinghua University Press wyl-dhh@tsinghua.edu.cn, 2020) Vijay Kumar, V.K.; Kunar, B.M.; Murthy, C.S.; Ramesh, M.R.Rock drilling is an essential operation in mining industries. Temperature at the bit-rock interface plays a major role in the wear rate of the drill bit. This paper primarily focuses on the wear rate of tungsten carbide (WC) drill bit and the interrelationship between temperature and wear rate during rotary drilling operations conducted using a computer numerical control (CNC) machine. The interrelationship between the temperature and wear rate was studied with regard to three types of rock samples, i.e., fine-grained sandstone (FG) of uniaxial compressive strength (UCS) that is 17.83 MPa, medium-grained sandstone (MG) of UCS that is 13.70 MPa, and fine-grained sandstone pink (FGP) of UCS that is 51.67 MPa. Wear rate of the drill bit has been measured using controlled parameters, i.e., drill bit diameter (6, 8, 10, 12, and 16 mm), spindle speed (250, 300, 350, 400, and 450 rpm), and penetration rate (2, 4, 6, 8, and 10 mm/min), respectively. Further, a fully instrumented laboratory drilling set-up was utilized. The weight of each bit was measured after the bit reached 30 mm depth in each type of the rock sample. Furthermore, effects of the bit-rock interface temperature and operational parameters on wear rate of the drill bits were examined. The results show that the wear rate of drill bits increased with an increase in temperature for all the bit-rock combinations considered. This is due to the silica content of the rock sample, which leads to an increase in the frictional heat between the bit-rock interfaces. However, in case of medium-grained sandstone, the weight percentage (wt%) of SiO2 is around 7.23 wt%, which presents a very low wear rate coefficient of 6.33×10?2 mg/(N·m). Moreover, the temperature rise during drilling is also minimum, i.e., around 74 °C, in comparison to that of fine-grained sandstone and fine-grained sandstone pink. In addition, this paper develops the relationship between temperature and wear rate characteristics by employing simple linear regression analysis. © 2019, The Author(s).Item Reliability-based analysis of probability density function and failure rate of the shovel–dumper system in a surface coal mine(Springer Science and Business Media Deutschland GmbH, 2021) Kumar, N.S.H.; Choudhary, R.P.; Murthy, C.S.The research article presents a reliability-based analysis of probability density function, and the failure rate of a shovel-dumper system was determined based on Weibull distribution in an open cast coal mine. Referring to the bathtub-model along with the Weibull distribution of a shovel and dumpers, decreasing, constant and increasing failure rates are represented using the RWB. To demonstrate the bathtub model and reliability model of combining shovel and dumpers, historical data such as TBF and TTR were used. The obtained bathtub curve shows that the influencing parameters such as ?, ? and ? had a better useful life after 7080 working hours. Also, the ANN model was developed to predict the PDF, failure rate and reliability function. It has been found that the values of RMSE and R2 were 0.00068 and 0.9565 for PDF, 0.0004342 and 0.98904 for failure rate and RMSE and R2 were 0.9739 and 0.000497 respectively. © 2020, Springer Nature Switzerland AG.Item A Comparative Study and Regression Analysis on Physico-Thermal Properties using Pongamia Pinnata - Waste Cooking Oil Methyl Ester Mixture(Taylor and Francis Ltd., 2025) Khale, B.R.; Kunar, B.M.; Murthy, C.S.Development of alternative fuels over the past three decades is trending research for the replacement or supplement of the mineral-based fuels. In the present study, a combined biodiesel mixture was prepared volumetrically from methyl esters of pongamia pinnata and waste cooking oil (50:50). Physico-thermal properties (Density, viscosity and calorific value) for blends varying from 5 to 30% were determined, for both combined biodiesel blends and their respective sources. Further, a comparative study on the physico-thermal properties of combined biodiesel blends with their respective sources was made. Similar trends were observed between the combined biodiesel blends and their respective sources. i.e., density and kinematic viscosity increased with increase in blend percentage. Alternatively, a decreasing trend was observed in the calorific value. Statistical analysis using Minitab was carried out. Backward elimination method was used to develop a regression model to determine the coefficient of determination between the properties and the volumetric contribution of blends. The models were significant at a confidence interval of 95%. The R-Square value for predicting density, kinematic viscosity and the calorific value was 99.37%, 99.05% and 99.84% respectively. © 2021 Taylor & Francis Group, LLC.Item A polysulfone/MIL-125(Ti) mixed matrix membrane for removing toxic dyes and heavy metals from water(Springer Science and Business Media Deutschland GmbH, 2025) Shivarama, B.; Isloor, A.M.; Murthy, C.S.; Prabhu, B.; Abdul Rashid, S.A.In this work, a titanium-incorporated metal–organic framework nanoadditive was used to study its efficiency in removing heavy metals and dyes from contaminated water. The use of MIL-125 (Ti) nanoadditive-incorporated polysulfone membranes has been tested for the elimination of heavy metals such as cadmium and lead as well as synthetic dyes, such as reactive black-5 (RB-5) and reactive orange -16 (RO-16). The incorporation of metal–organic frameworks (MOFs) into polysulfone matrices can increase the performance of the membrane for specific applications, such as dye removal and heavy metal rejection. The MIL-125 (Ti) is a well-known MOF with excellent chemical stability, large surface area, and adjustable pore size, making it suitable for membrane fabrication. This study fabricated membranes composed of MIL-125(Ti) and polysulfone (PSF) with MOF doses ranging from 0.5 to 3 wt %. Compared with the pristine PSF membrane, the pore-forming agent PVP was used at a 12% concentration, increasing the pore size and porosity. The hydrophilicity, water flux, and antifouling nature of the fabricated membrane were studied. The dye removal and heavy metal rejection experiments were carried out, and a dye removal efficiency of 90% for RB-5 and 47% for RO-16 was exhibited by the M-1 membrane. Furthermore, the M-2 membrane resulted in heavy metal rejection of 89.33% for Cd2+, and M-3 resulted in 68.81% for Pb2+ at a feed concentration of 500 ppm. Hence, the membranes showed good stability and efficiency with a high feed concentration of heavy metals. In the present study, metal ion rejection was studied without the use of any complexing agents. © King Abdulaziz City for Science and Technology 2025.