Search

Your search keyword '"Vijayakumar, S. P."' showing total 324 results
Start Over Author "Vijayakumar, S. P."
324 results on '"Vijayakumar, S. P."'

16. Role of long-range van der Waals interaction in the coefficient of static friction

Author

Narayanan, Ram, Parashar, Prachi, Shajesh, K. V., and Vijayakumar, S.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

To investigate the role of long-range van der Waals interactions in static friction, we derive an analytic expression for the coefficient of static friction $\mu_s$ between two thin layers of polarizable materials under zero load. For simplicity, we model the surface roughness with sinusoidal corrugations and calculate the interaction energy perturbatively up to the second order in corrugation amplitude. The ratio of corresponding maximum lateral Casimir force to normal Casimir force is defined as the coefficient of static friction, which is found to be independent of the dielectric properties of the materials. It depends on the geometric properties, like interlayer separation, corrugation amplitude, and wavelength of the corrugation. As a proof of concept, our predicted values of $\mu_s$ for the 2D van der Waals materials graphene and hexagonal boron nitride are in reasonable agreement with previously reported values in the literature. This simplistic model could be generalized by incorporating other forces, such as the frequency-dependent contributions of van der Waals interactions and electrostatic interactions., Comment: 11 Pages, 7 Figures, 1 Table

Published
2022

32. Controllability of consensus of multi-agent networks over heterogeneous dynamics

Author

Vijayakumar S. Muni, Kallu Vetty Muhammed Rafeek, Athira V.S., and Gudala Janardhana Reddy

Subjects
Heterogeneous multi-agent systems, Controllability, Leader–follower framework, Applied mathematics. Quantitative methods, T57-57.97
Abstract

This work investigates controllability issues under the leader–follower framework of consensus problem on multi-agent networks where its agents exhibit the heterogeneous dynamics involving first-, second-, and third-order integrator agents on a continuous time-scale. The communication topology is directed, time-invariant, and the reliability of all interactions are unity. We employ two kinds of consensus protocols that are linear and distributed. The necessary and sufficient criteria for the controllability of followers’ dynamics through the selected leaders are obtained in terms of matrix-rank conditions. We also obtain some necessary conditions of controllability involving eigenvectors of system matrices. It is verified that, if either of the first-, second-, or third-order integrator agents are absent, then the controllability of the network becomes equivalent to the controllability of the communication topology just like those of the networks with homogeneous dynamic agents. Obtained results are verified with illustrative examples.

Published
2023
Full Text
View/download PDF

45. Competition in Monopoly: Teaching-Learning Process of Financial Statement Analysis to Information Technology Management Students

Author

Bharathi, Vijayakumar S. and Kulkarni, Mugdha Shailendra

Abstract

This research article investigates the impact of using a Monopoly Board Game (MBG) in the teaching learning process of financial statement analysis (FSA) to information technology management students, who earlier had little or no finance or accounting prior educational background. The subjects were students (N=159) in an Indian University. The study; first, narrated the process of administering MBG; second, quantitatively analyzed the learning experience through a structured questionnaire to validate the research objectives. The study resulted in the creation of three factor-clusters namely cognizance, collaboration, and enthusiasm which impacted students' MBG learning experience over the traditional teaching-learning methods. Results showed that factors relating to cognizance are more impacting than collaboration and enthusiasm. In the future, this research can be extended to advanced finance courses and can be integrated with relevant educational theories that underpin teaching-learning processes in higher education to other disciplines.

Published
2020
Full Text
View/download PDF

49. Erythropoietin in Neonates with Perinatal Asphyxia Undergoing Therapeutic Hypothermia—A Prospective Cohort Study

Author

Charki, Siddu, Patil, S. V., Biradar, Vijayakumar S., Kolkar, Yalagurswamy, Nanavati, Ruchi, Rao, Suman, and Arya, Sugandha

Abstract

Aims To assess the safety and feasibility of erythropoietin (EPO) in asphyxiated neonates undergoing therapeutic hypothermia (TH).Subjects and methods This study enrolled 60 neonates with HIE undergoing TH. 30 neonates were divided into EPO with TH group, where neonates received EPO (dose), at a dose rate of 1000 IU/kg/48 hours, for four doses and the remaining 30 neonates undergoing TH were into control group. Magnetic resonance imaging brain was undertaken between 10 and 14 days of life in surviving neonates. The Bayley Scales of Infant (BSI) Development IV was performed at regular intervals up to the age of 12 months.Results Amplitude-integrated electroencephalogram (aEEG) showed burst suppression (19% vs. 11%), low voltage (10% vs. 4%), and flat trace (7% vs. 3%) in control group in comparison with EPO concurrent with TH group which was statistically significant. Brain magnetic-resonance imaging (MRI) done at 12 days (±2 days) showed significant brain injury patterns such as severe brain injury (4% vs. 9% P = .05) and regional specific HIE (7% vs. 13%, P = .03) in control group of only TH neonates. At 12 months, neurodevelopment outcomes in EPO with TH group neonates showed a favorable outcome.Conclusion rhEPO concurrent with TH in HIE neonates resulted in significantly less severe brain injuries in MRI brain in HIE neonates. aEEG changes were less statistically significant in EPO with TH group with favorable neurodevelopmental outcomes at 12 months of age.

Published
2024
Full Text
View/download PDF

50. Elevation-dependence of warming due to aerosol-induced snow darkening over the Himalayan-Tibetan region

Author

Vijayakumar S Nair, K H Usha, and S Suresh Babu

Subjects
elevation dependent warming, aerosol-induced snow darkening, absorbing aerosols, Himalayan-Tibetan region, Environmental technology. Sanitary engineering, TD1-1066, Environmental sciences, GE1-350, Science, Physics, QC1-999
Abstract

Temperature trends over the high-altitude mountains depict an increase with elevation during recent years. These stratified warming trends observed over the Himalayan-Tibetan (HT) regions are higher than the mean warming trends observed over low-elevation regions of South and East Asia, which is attributed to several factors including snow albedo feedback, clouds and water vapor feedback. In this study, we demonstrate the effects of deposition of absorbing aerosols like black carbon and dust on snow albedo and its implications for elevation-dependent warming (EDW). Though the aerosol concentration decreases with elevation, warming due to aerosol-induced snow darkening increases with elevation. Further, surface cooling due to the direct radiative effects (DRE) of aerosols is found to decrease with elevation, which also favors higher warming at high altitudes. The effects of both the deposition of absorbing aerosols on snow albedo and the surface cooling due to the DRE of atmospheric aerosols could strengthen EDW. This study clearly shows the potential of albedo feedback due to aerosol-cryosphere interaction as one of the physical mechanisms contributing to the observed EDW over the HT region.

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results