Faculty Publications

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Author: search.filters.author.Kumari, D.Has files: No

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    Recent advancements in switched capacitor-based multilevel inverters
    (River Publishers, 2025) Kumar, D.; Raushan, R.; Kumari, D.; Bhushan, R.
    This chapter comprehensively reviews recent advances in switched capacitorbased multilevel inverters (SCMLIs) within the realm of power electronics. It outlines the fundamental principles of multilevel inverters, underscoring the role of switched capacitors in achieving higher voltage levels and refined waveform quality. The chapter critically examines the challenges in switched capacitor-based multilevel inverter designs, emphasizing recent research on circuit topologies and modulation strategies, including aspects like voltage balancing. Moreover, it discusses the integration of SCMLIs in electric vehicles and renewable energy systems and highlights their potential to enhance efficiency, improve power quality, and seamlessly integrate with modern power grids. The chapter succinctly captures the forefront of SCMLI technology, offering insights into its transformative impact on ongoing innovation to address evolving challenges in inverter topologies. © 2025 River Publishers. All rights reserved.
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    Experimental analysis of CUBIC TCP in error prone MANETs
    (IEEE Computer Society help@computer.org, 2014) Kumari, D.; Tahiliani, M.P.; Shenoy, U.K.K.
    CUBIC TCP, a variant of the traditional TCP, is the default congestion control algorithm deployed in Linux kernels above 2.6 version. CUBIC is mainly designed for high speed, long distance wired networks and several studies have exhibited that it indeed, enriches the performance of such networks. Recently, hand-held devices such as smart phones have grown very popular and there has been a lot of interest in the research community to design efficient operating systems for such devices. Android is one of the latest open source mobile operating system and it is based on a reduced version of the Linux kernel. Since it is Linux based, CUBIC TCP remains the default TCP in Android also. These hand-held devices, however, are connected to low speed wireless networks and consequently, CUBIC TCP deployment in Android ends up being a mismatch. The main goal of this work is to analyze the behavior of CUBIC TCP in low speed error prone wireless networks and bring out the challenges and issues related to the same. © 2014 IEEE.
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    Empirical Evaluation of Traffic Shaping Algorithms for Time Sensitive Networking
    (Institute of Electrical and Electronics Engineers Inc., 2022) Naik, K.; Kumari, D.; Tahiliani, M.P.
    Standard Ethernet networks cannot provide solutions to handle latency sensitive applications efficiently. The packet scheduling algorithms like First In First Out (FIFO), Class Based Queueing (CBQ), and others do not provide efficient solutions to Quality of Service (QoS) parameters like end-toend delay, packet loss, and jitter. Time Sensitive Networking (TSN) can be used as a solution to provide QoS to time sensitive applications. TSN has emerged as a future of realtime communication. The main advantage of TSN is that it enables determinism by supporting time critical traffic while the best effort traffic is also present in the network. This paper explores two of the most popular and widespread traffic shaping mechanisms in TSN: Time Aware Shaper (TAS) and Credit Based Shaper (CBS). IEEE 802.1Qbv is used for delivering time assurance using TAS. CBS is a key traffic shaping algorithm to provide bandwidth assurance to the time critical and real time traffic, such as the audio traffic. This paper evaluates TAS and CBS using TSN enabled Network Interface Cards (NIC) with time synchronization, real time kernel and real traffic, which includes time sensitive traffic and elastic background traffic. © 2022 IEEE.
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    Exploring the potential role of quercetin in corrosion inhibition of aluminium alloy 6063 in hydrochloric acid solution by experimental and theoretical studies
    (Taylor and Francis Ltd., 2022) Kumari, D.; Venugopal, P.P.; Reena Kumari, P.D.; Chakraborty, D.
    Quercetin was evaluated as corrosion inhibitor for AA6063 in 0.5 M HCl solution by employing weight-loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Analysis (EDX), Atomic Force Microscopy (AFM), X-Ray photoelectron spectroscopy (XPS) techniques allied to quantum chemical studies. Electrochemical results substantiate that the inhibition efficacy of quercetin increases proportionally with the concentration of the inhibitor. The effect of temperature on the corrosion behavior of the alloy was studied in the range of 30–60 °C. Potentiodynamic polarization study confirms the mixed type of inhibition by quercetin with preferential control of the cathodic reaction. The adsorption of quercetin on alloy surface was explained through the Langmuir adsorption isotherm model. ΔG°ads values and its variation with the temperature ensured spontaneous adsorption through chemisorption and the process was endothermic. Further, quantum chemical parameters calculated from Density Functional Theory (DFT) method for quercetin, proved a perfect correlation between structure and corrosion inhibition efficiency. © 2021 Informa UK Limited, trading as Taylor & Francis Group.
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    Design and fabrication of all-inorganic transport materials-based Cs2SnI6 perovskite solar cells
    (Springer, 2023) Kumari, D.; Jaiswal, N.; Shukla, R.; Punetha, D.; Pandey, S.K.; Pandey, S.K.
    With lead-based perovskite materials, lead content and long-term stability are the big concerns. Recently, Cesium tin iodide (Cs2SnI6) double perovskite has gained recognition as a stable and environment-friendly photovoltaic material compared to lead-based perovskite materials. In the present study, we have investigated Cs2SnI6 based solar cell with all inorganic transport materials using SCAPS-1D. The optimized device exhibited a maximum efficiency of about 18%. Further we fabricated Cs2SnI6 perovskite films using a solution process approach, utilizing CsI and SnI4 in a 2:1 ratio. For synthesized double perovskite film, the crystallinity, morphologies, and optical characteristics were examined. Additionally, the stability analysis confirmed that the prepared perovskite films were stable for more than two months under ambient exposure. Finally, utilizing the synthesized Cs2SnI6 thin films as an absorber material, we fabricated two solar cells without and with hole transport layer (HTL), having configurations of glass/FTO/ZnO/Cs2SnI6/Ni and glass/FTO/ZnO/Cs2SnI6/ MoS2/Ni, respectively, in the ambient conditions. As a major finding, it has been observed that the inclusion of MoS2 as HTL improved overall performance, with an enhancement in the power conversion efficiency (PCE) of nearly 45% compared to the device without HTL. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.