Faculty Publications
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Item Dynamics of multi-campaign propagation in online social networks(Association for Computing Machinery, Inc acmhelp@acm.org, 2015) Thejaswi, M.; Vijayaraghavan, S.; Das, A.; Santhi Thilagam, P.Ever since the advent of online social networking, people have been voluntarily posting and consuming information on the web. This new method to communicate digitally provides the means to spread information considerably far in a very short span of time with minimal resources. Social networks are increasingly being used to spread misinformation online due to low-costs in organizing grassroots of these campaigns. Our goal in this paper is to determine the efficiency with which campaigns can succeed in an online social network, efficiency represents the ease with which a campaign can triumph over other competing campaigns in a network. We model the information diffusion using Multi-Campaign Independent Cascade Model, and by applying node coercion and link cutting as campaign limiting strategies we ascertain how efficiently a campaign can succeed. The efficiency measure tackles the problem of determining the survivability of campaigns, which is used to ensure success or failure of a campaign using campaign limiting strategies.Item Dynamics of multi-campaign propagation in online social networks(Institute of Electrical and Electronics Engineers Inc., 2015) Thejaswi, M.; Vijayaraghavan, S.; Das, A.; Santhi Thilagam, P.Ever since the advent of online social networking, people have been voluntarily posting and consuming information on the web. This new method to communicate digitally provides the means to spread information considerably far in a very short span of time with minimal resources. Social networks are increasingly being used to spread misinformation online due to low-costs in organizing grassroots of these campaigns. Our goal in this paper is to determine the efficiency with which campaigns can succeed in an online social network, efficiency represents the ease with which a campaign can triumph over other competing campaigns in a network. We model the information diffusion using Multi-Campaign Independent Cascade Model, and by applying node coercion and link cutting as campaign limiting strategies we ascertain how efficiently a campaign can succeed. The efficiency measure tackles the problem of determining the survivability of campaigns, which is used to ensure success or failure of a campaign using campaign limiting strategies. © 2015 IEEE.Item Dilatometer studies on LAMOX based electrolyte materials for solid oxide fuel cells(Elsevier Ltd, 2021) Das, A.; Lakhanlal, u.; Shajahan, I.; Prasad Dasari, H.P.; Saidutta, M.B.; Harshini, H.The present study deals with the citrate complexion synthesis of LAMOX-based Solid Oxide Fuel Cell (SOFC) electrolyte materials (La1.8Dy0.2Mo2-xWxO9 (x = 0, 0.1, 0.2, 0.5, and 1), La1.8Dy0.2Mo2-xGaxO9 (x = 0.1 and 0.2), and La1.8Dy0.2Mo2-xVxO9 (x = 0.025, 0.05, 0.1, and 0.2)) and their characterization to understand the sintering behaviour and phase stability. From the dilatometer studies, the linear shrinkage and shrinkage rate of the LDMW (x = 0, and 0.1) showed better shrinkage than LM and LDM. Gallium addition (LDMG) and Vanadium addition (LDMV) showed a negative impact on shrinkage behaviour. In the temperature range of 500–580 °C, the abrupt change in shrinkage rate showed the transition of phase from ? to ? for the LM. The modification of LM to LDM, LDMW, and LDMV suppressed the formation of the ? phase. During thermal expansion behaviour study in the temperature range of 100–500 °C and 550–800 °C, the LM sintered pellet showed the coefficient of thermal expansion (CTE) values of 13.3 ? 10?6/°C and 21.6 ? 10?6/°C respectively. The LDM and LDMW sintered pellets showed the CTE values in the range of 14–15 ? 10?6/°C and 16–19 ? 10?6/°C, respectively. The relative density of the sintered pellets (1100 °C/5 h in air) (LM, LDM, LDMW, and LDMG (x = 0.1)) is found to be >90%. It provides the suitability of these materials for further investigation as electrolytes of SOFCs/SOECs. © 2020 Elsevier B.V.Item Women in Electrochemistry- Contributions, Challenges and Potential Solutions(IOP Publishing Ltd, 2022) Das, A.; Nagaraj, P.; Bhat Panemangalore, D.The perspectives gained over the years by women working in electrochemistry are described in order to throw light on their history and current status and achievements in this field, the potential that the future holds, and the role that well-established female electrochemists and the electrochemical societies can play in improving upon the under-representation and under-recognition of women in electrochemistry. Here, a hopeful and optimistic future is presented, in which men and women, both equally contribute to this field, which encompasses our entire life, from corrosion and life of materials to transportation industry. © 2022 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.Item Electrical conductivity studies on LAMOX based electrolyte materials for solid oxide fuel cells(Elsevier Ltd, 2022) Srijith; Lakhanlal, u.; Das, A.; Prasad Dasari, H.P.; Saidutta, M.B.In this study, the electrical conductivity of the LAMOX based electrolytes (La1.8Dy0.2Mo2-xWxO9 (x = 0, 0.1, 0.2, 0.5, and 1), and La1.8Dy0.2Mo2-xGaxO9 (x = 0.1)) synthesized by the citrate complexion method has been studied using DC four-probe method. The electrical conductivity of the electrolytes is measured in the temperature range of 800–400 °C in the air (∼100 ml min−1). The effect of W and Ga substitution at the Mo site on the electrical conductivity is evaluated. The long-term electrical conductivity stability test (time on stream) (5 h) is conducted at 650, 580, and 520 °C to study the effect of possible phase transition on electrical conductivity. A high-temperature XRD study is also conducted in the temperature range of 500–650 °C (during heating and cooling) on selected electrolyte materials (La1.8Dy0.2Mo2-xWxO9 (x = 0 and 0.1) and La1.8Dy0.2Mo2-xGaxO9 (x = 0.1)) to study the α↔β phase transition. The electrical conductivity of these electrolytes in the air at 800 °C is in the range of 5.3 × 10−2 – 14 × 10−2 S cm−1. The activation energy (EA) of these electrolytes is in the range of 1.11–1.62 eV. The VTF parameters σo, B, and To are in the range of 67.46–395.88 S cm−1 K0.5, 0.122–0.254 eV, and 247–347 °C, respectively. The La1.8Dy0.2Mo2-xWxO9 (x = 0.1) shows highest electrical conductivity (14 × 10−2 S cm−1, EA = 1.54 eV) among all electrolytes in air at 800 °C and for this material the VTF parameters σo, B, and To are 170.32 S cm−1 K0.5, 0.153 eV, and 302 °C, respectively. © 2022 Elsevier Ltd and Techna Group S.r.l.Item High-Potential Aqueous Asymmetric Supercapacitor Based on 2D Molybdenum Disulfide and Vanadium Pentoxide Electrodes(American Chemical Society, 2024) Pullanchiyodan, A.; Haridasan, G.T.; Sreeram, P.; Das, A.; T M Balakrishnan, N.; Prasanth, P.; Hegde, A.A wide-operating-voltage asymmetric supercapacitor (ASC) based on an aqueous electrolyte has great promise in the current energy storage technologies by providing better energy density, power density, safety, cost effectiveness, and long cycle life. Herein, the fabrication of an ASC using a 2D transition metal dichalcogenide (molybdenum disulfide (2D MoS2)) and a transition metal oxide (vanadium pentoxide, V2O5) as the negative and positive electrode, respectively, was demonstrated. The electrochemical and galvanostatic charge-discharge analysis of both positive (V2O5) and negative electrodes (2D MoS2) was carried out in a three-electrode setup. The results show stable operating potentials of −0.9 and 1.0 V for MoS2 and V2O5 electrodes, respectively. By combining these positive and negative electrodes in a 1 M sodium sulfate (Na2SO4) aqueous electrolyte, the developed ASC reveals a wide operating potential (2.0 V). The electrochemical analysis of the ASC in a stable operating potential of 1.4 V gives an areal capacitance and energy density of 30 mF/cm2 and 8.2 μWh/cm2, respectively, at a scan rate of 1 mV s-1. The performance of the ASC was analyzed for 5000 continuous charge-discharge cycles at a higher current of 3.5 mA. After 5000 cycles, the ASC exhibits more than 80% capacitance retention with a specific capacitance of 0.85 mF/cm2 © 2024 American Chemical Society.Item Mechanical performance of bio-based materials in structural applications: A comprehensive review(Elsevier Ltd, 2025) Barbhuiya, S.; Das, B.B.; Kapoor, K.; Das, A.; Katare, V.The pursuit of sustainable materials in construction has led to increased interest in bio-based materials for structural applications. This review paper examines the mechanical performance of structural members made from bio-based materials, including natural fibres, bio-based polymers, and engineered wood products. Key mechanical properties such as tensile, compressive, and flexural strength, as well as durability under environmental stressors, are analyzed to understand their suitability for load-bearing applications. The paper also discusses factors affecting mechanical behaviour, including moisture absorption, temperature sensitivity, and fabrication techniques. A comparative analysis highlights the performance of bio-based materials against conventional materials like steel and concrete, emphasizing both their strengths and limitations. Enhancements in bio-based composites, including hybridization and nanotechnology, are reviewed for their potential to improve mechanical robustness. Additionally, sustainability aspects, such as life cycle assessment and end-of-life biodegradability, are evaluated to underscore the environmental benefits of bio-based structural members. The paper concludes with future research directions, advocating for innovation in bio-based material technology to meet structural demands and support the construction industry's shift toward greener practices. This review aims to provide a foundational understanding for engineers and researchers seeking to integrate bio-based materials into sustainable structural designs. © 2025 The AuthorsItem Boundary layers, transport and universal distribution in boundary driven active systems(SciPost Foundation, 2025) Dolai, P.; Das, A.We discuss analytical results for a run-and-tumble particle (RTP) in one dimension in presence of boundary reservoirs. It exhibits “kinetic boundary layers”, nonmonotonous distribution, current without density gradient, diffusion facilitated current reversal and optimisation on tuning dynamical parameters, and a new transport effect in the steady state. The spatial and internal degrees of freedom together possess a symmetry, using which we find the eigenspectrum for large systems. The eigenvalues are arranged in two bands which can mix in certain conditions resulting in a crossover in the relaxation. The late time distribution for large systems is obtained analytically; it retains a strong and often dominant “active” contribution in the bulk rendering an effective passive-like description inadequate. A nontrivial “Milne length” also emerges in the dynamics. Finally, a novel universality is proposed in the absorbing boundary problem for dynamics with short-range colored noise. Active processes driven by active reservoirs may thus provide a common physical ground for diverse and new nonequilibrium phenomena. © P. Dolai and A. Das.Item A systematic analysis on the electrospinnability of biocompatible poly(butylene adipate-co-terephthalate)(Institute of Physics, 2025) Das, A.; Anandhan, S.; Chethan, K.N.; Salins, S.S.; Shetty, R.; Shetty, S.Fine-tuning electrospun nanofibers is crucial for producing high-quality fibers. Taguchi Design of Experiment (DOE), along with various other computational techniques, has been used to optimize the electrospinning parameters of different polymers. Taguchi DOE has proven effective in optimizing electrospun nanofibers because it reduces the number of trials needed. In this study, the electrospinning parameters of poly (butylene adipate-co-terephthalate) (PBAT) were optimized and quantified using the Taguchi-based Response Surface Methodology (RSM) approach. The average fiber diameters were measured from Field Emission Scanning Electron Microscopy (FESEM) images using ImageJ software. Within the tested range of parameters and levels, the Analysis of Variance (ANOVA) study identified polymer concentration and flow rate as the most significant factors that influenced the fiber diameter. Polymer concentration accounting 56.94% of the variation, while Flow Rate (FR) accounts for 20.82%. The optimal parameter levels were predicted to be 10 wt% polymer concentration, 1 ml h?1 flow rate, 18 kV voltage, and a distance from tip to target of 15 cm, which yielded fibers with an average diameter of 231 nm and an accuracy of 88.61%. Overall, the results demonstrate that Taguchi DOE, coupled with RSM, is a reliable and efficient method for identifying the optimal parameter combinations to produce uniform, fine PBAT nanofibers intended for biomedical applications. © 2025 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.