Browsing by Author "Pai, R."

Now showing 1 - 7 of 7

Applications of computer in mining industry with special regard to shovel-dumper productivity
(2007) Aruna, M.; Murthy, Ch.S.N.; Pai, R.; Nand, R.
Now-a-days computer is used in every field of engineering, including mining industry, at various stages in various capacities. One of the major problems in surface mining is material handling, which involves transportation of both ore and overburden. Most of the projects make use of shoveldumper system in spite of its huge capital investment and recurring costs. Hence a lot of mind and time has to be devoted before its procurement so as to optimize their number and maximize its utility. This paper addresses various optimization models available for productivity analysis of shovel-dumper fleet. Match factor method is one of the commonly used techniques to know the relative coverage which shovels are getting from truck fleet. Operations research techniques like queuing theory, integer programming, simulation and goal programming consider the probabilistic nature associated with the system. Even though many models are available for optimization and analyzing the productivity of shovel dumper system, further research and study is needed to devise a desirable technique for the same.
Applications of computer in mining industry with special regard to shovel-dumper productivity
(2007) Mangalpady, M.; Murthy, Ch.S.N.; Pai, R.; Nand, R.
Now-a-days computer is used in every field of engineering, including mining industry, at various stages in various capacities. One of the major problems in surface mining is material handling, which involves transportation of both ore and overburden. Most of the projects make use of shoveldumper system in spite of its huge capital investment and recurring costs. Hence a lot of mind and time has to be devoted before its procurement so as to optimize their number and maximize its utility. This paper addresses various optimization models available for productivity analysis of shovel-dumper fleet. Match factor method is one of the commonly used techniques to know the relative coverage which shovels are getting from truck fleet. Operations research techniques like queuing theory, integer programming, simulation and goal programming consider the probabilistic nature associated with the system. Even though many models are available for optimization and analyzing the productivity of shovel dumper system, further research and study is needed to devise a desirable technique for the same.
Experimental studies on turning of discontinuously reinforced aluminium composites under dry, oil water emulsion and steam lubricated conditions using TAGUCHI's technique
(2009) Shetty, R.; Pai, R.; Rao, S.S.
This paper reports on the experimental investigations carried out under dry, oil water emulsion and steam lubricated conditions in turning of DRACs. The measured results were then collected and analyzed with the help of the commercial software package MINITAB15. The experiments were planned on orthogonal arrays, made with prefixed cutting parameters and different lubricated conditions. An analysis of variance (ANOVA) was carried out to check tho validity of the proposed parameters and also their percentage contributions. The results of the tests show that with proper selection of the range of cutting parameters, it is possible to obtain better performance under steam lubricated condition.
IMU-based segmental root mean square analysis of gait in individuals with cerebellar ataxia: a pilot cross-sectional study
(Nature Research, 2025) Mendonca, J.; Joshua, A.M.; Shetty, S.; Chemmangat, K.; Krishnan, S.; Kumar, K.V.; Misri, Z.; Pai, R.; Pai, S.
Cerebellar ataxia (CA) affects limb movement, balance, and gait. Subjective rating scales like Scale for the Assessment and Rating of Ataxia (SARA) may underestimate gait severity. Inertial measurement units (IMUs) offer an objective gait analysis. Impaired trunk control might compromise gait performance and stability in individuals with ataxia. This study quantified trunk kinematics and gait parameters using Root Mean Square (RMS) values, comparing CA to healthy individuals. Ten CA cases and twenty healthy controls were recruited. Six IMU sensors positioned at anatomical landmarks recorded data via two ESP32 microcontrollers using Wi-Fi. Participants walked a 10-meter path at a self-selected pace. RMS mean linear and angular velocity and angular deviation were calculated. Individuals with CA showed decreased mediolateral linear acceleration at the left shoulder (p = 0.001) and an increased vertical linear acceleration at the right ankle (p = 0.015), left shoulder (p = 0.028), and back (p = 0.019). Total angular velocity was lower at the right shoulder (p = 0.017), left shoulder (p = 0.005), back (p = 0.002), and both ankles (right: p = 0.001; left: p = 0.001). The correlation between IMU-derived features and SARA-gait score in the CA group was not statistically significant (all p > 0.05), except for the right shoulder’s mediolateral angular velocity (p = 0.046). Both ankle segments’ angular deviations (right: p = 0.001; left: p = 0.006) were reduced. The CA group revealed reduced RMS linear and angular velocities. IMU-based trunk and gait analysis provides a more objective method that would help in planning targeted rehabilitation treatments. Trial registration: The study was approved by the Institutional Ethics Committee (IEC), Kasturba Medical College, Mangalore, Manipal Academy of Higher Education (IEC KMC MLR 12/2023/483) on 21st December 2023 and the Clinical Trial Registration (CTRI/2024/07/070614) on July 15th, 2024. © The Author(s) 2025.
A pressured steam JET approach to tool wear minimization in cutting of metal matrix composites
(2007) Anjaiah, D.; Shetty, R.; Pai, R.; Kini, M.V.; Rao, S.S.
Metal matrix composites (MMCs) have been found to possess tremendous prospective engineering applications that require materials offering a combination of lightweight with considerably enhanced mechanical and physical properties. However, the applications of MMCs are limited by their poor machinability which is a result of their highly abrasive nature that causes excessive wear to the cutting tools. In this study, an investigation into the mechanism of the tool wear in cutting of MMCs is carried out. It is found that during cutting of an MMC, the tool cutting edge will impact on the reinforcement particles. The impacted particles will then either be dislodged from the matrix, doing no harm to the tool, or be embedded into the matrix, ploughing on the tool flank and causing excessive tool flank wear. According to this tool wear mechanism, a pressured steam jet approach is developed for the minimization of the tool wear by preventing the impacted reinforcement particles from being embedded in the workpiece matrix. Experimental tests for cutting of SiC-aluminum MMC using cubic boron nitride (KB-90) and polycrystalline diamond (KP-300) tool inserts with the aid of the pressured steam jet are conducted. The results show that from full factorial design of experiments the effect of the pressured steam jet plays a significant role on the tool wear followed by tool inserts and depth of cut. The working mechanism of the pressured steam jet method and the experimental testing results are discussed in detail.
Steam as coolant and lubricant in turning of metal matrix composites
(2008) Shetty, R.; Pai, R.; Kamath, V.; Rao, S.S.
Green cutting has become focus of attention in ecological and environmental protection. Steam is cheap, pollution-free and eco-friendly, and then is a good and economical coolant and lubricant. Steam generator and steam feeding system were developed to generate and feed steam. Comparative experiments were carried out in cutting AA6061-15 vol.% SiC (25 ?m particle size), with cubic boron nitride (CBN) insert KB-90 grade under the conditions of compressed air, oil water emulsion, steam as coolant and lubricant, and dry cutting, respectively. The experimental results show that, with steam as coolant and lubricant, gradual reduction in the cutting force, friction coefficient, surface roughness and cutting temperature values were observed. Further, there was reduction in built up edge formation. It is proved that use of water steam as coolant and lubricant is environmentally friendly. 2008 Zhejiang University and Springer-Verlag GmbH.
The effects of sulphuric acid concentration and the sequential layup of glass fibre reinforcements on the diffusion behaviour of glass epoxy composite laminates were studied. In all, composites of six different resin systems viz., general purpose polyester, bis phenol-A polyester, vinyl ester, LY 556 epoxy, and MY 750 epoxy resins, reinforced with different layup sequencing consisting of chopped strand mat (CSM) and woven roving mat (WR) were exposed to sulphuric acid environments of different concentrations. The results of the study indicated that isophthalic polyester resin exhibited maximum resistance to sulphuric acid while general purpose polyester resin performed relatively inferior. The diffusion phenomenon became anamalous as the concentration of the sulphuric acid increased. Among the layup sequences considered, composite specimens with CSM as the skin layers exhibited higher weight gain than those with WR as the skin layers.
(SAGE Publications Ltd, Acid resistance of glass fibre composites with different layup sequencing: Part I-diffusion studies) Pai, R.; Kamath, M.S.; Rao, R.M.V.G.K.
1997