Browsing by Author "Joshi, S."

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A new probabilistic rekeying method for secure dynamic groups
(2008) Joshi, S.; Pais, A.R.
Logical Key Hierarchy (LKH) is a basic method in secure multicast group rekeying. LKH maintains a balanced tree which provide uniform cost of O(log N) for compromise recovery, where N is group size. However, it does not distinguish the behavior of group members even though they have different probabilities of join or leave. When members have diverse changing probability the gap between LKH and the optimal rekeying algorithm will become bigger. The Probabilistic optimization of LKH (PLKH) scheme, optimized rekey cost by organizing LKH tree with user rekey characteristic. In this paper, we concentrate on further reducing the rekey cost by organizing LKH tree with respect to compromise probabilities of members using new join and leave operations. Simulation results show that our scheme performs 18% to 29% better than PLKH and 32% to 41% better than LKH.
A new probabilistic rekeying method for secure multicast groups
(2010) Pais, A.R.; Joshi, S.
The Logical Key Hierarchy (LKH) is the most widely used protocol in multicast group rekeying. LKH maintains a balanced tree that provide uniform cost of O(log N) for compromise recovery, where N is group size. However, it does not distinguish the behavior of group members even though they may have different probabilities of join or leave. When members have diverse changing probabilities, the gap between LKH and the optimal rekeying algorithm will become bigger. The Probabilistic optimization of LKH (PLKH) scheme, optimized rekey cost by organizing LKH tree with user rekey characteristic. In this paper, we concentrate on further reducing the rekey cost by organizing LKH tree with respect to rekey probabilities of members using new join and leave operations. Simulation results show that our scheme performs 18 to 29% better than PLKH and 32 to 41% better than LKH. © 2010 Springer-Verlag.
A novel effective immobilization of glucose oxidase on Ni0.25Zn0.25Cu0.25Co0.25La0.06Fe1.94O4 – Chitosan nanocomposite as an enzymatic glucose biosensor
(Elsevier B.V., 2023) Deepapriya, S.; Rodney, J.D.; John, J.; Joshi, S.; Udayashankar, N.K.; Lakshmi Devi, S.; Jerome das, S.
An effectual enzymatic glucose biosensor has drawn significant attention in the natural world due to its continuous glucose monitoring systems on human beings. A need for accurate and dependable glucose biosensors is needed and has notably augmented the keen interest to synthesize new non-invasive glucose monitoring systems in the recent phase. A novel Ni0.25Zn0.25Cu0.25Co0.25La0.06Fe1.94O4 nanocomposite has been synthesized via the combustion method to develop an appreciable glucose biosensor. The glucose biosensor was fabricated by immobilization of glucose oxidase (GOx) onto chitosan (CH)-Ni0.25Zn0.25Cu0.25Co0.25La0.06Fe1.94O4 heterojunction nanocomposite on FTO glass substrate. The performance of the as-prepared enzymatic glucose biosensor was estimated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrochemical studies revealed an enhanced diffusion of molecules on the electrode surface, superior charge transfer rate, high sensitivity, and fast response time. The Ni0.25Zn0.25Cu0.25Co0.25La0.06Fe1.94O4-CH bi-junction conjoining with GOx exhibits a higher sensitivity of 52.76 µAmM-1cm−2 in a comprehensive undeviating range. The catalytic properties of the electrode in the H2O2 solution were studied using cyclic voltammetry, which showed a good linear response with an increase in scan rate and peak current resulting in enriched electrostatic interaction. In addition, the fabricated biosensor with a low Michaelis-Menten constant contributes a better affinity of the electrode surface towards glucose oxide. © 2023 Elsevier B.V.
Cobalt-doped LaFeO3 for photo-Fenton degradation of organic pollutants and visible-light-assisted water splitting
(Springer, 2024) James, A.; Rodney, J.D.; Manojbabu, A.; Joshi, S.; Rao, L.; Badekai Ramachandra, B.R.; Udayashankar, N.K.
The increasing demand for clean energy sources and the growing concerns about environmental pollution have led to a significant interest in developing efficient photocatalytic and photoelectrochemical systems. Here, we report the visible-light-induced photo-Fenton catalytic degradation of Methylene Blue (MB) dye over LaFeO3 and LaCo xFe1−xO3 (x = 0.01, 0.05, 0.1) catalysts synthesized via the facile combustion method. The LaCo0.01Fe0.99O3 has significantly enhanced the photo-Fenton catalytic efficiency of LaFeO3 from 67.75 to 93.85% for MB dye removal after 180 min of light irradiation. The rate constants calculated via the pseudo-first-order kinetics mechanism are found to be 0.00532/min for LaFeO3 and 0.01476/min for LaCo0.01Fe0.99O3, respectively. In addition, the most effective LaCo0.01Fe0.99O3 catalyst has demonstrated remarkable degradation performance towards Tetracycline (TC) and Methyl Orange (MO) dye with an efficacy of 93.81% and 69.67%, respectively, indicating its versatility. Further, the pristine and doped LaFeO3 were structurally optimized using DFT, and the computed band gaps were following the experimental data. Interestingly, the same catalyst can be employed as a light-induced electrocatalyst in addition to water treatment by taking advantage of its dual functionality. The LaCo0.01Fe0.99O3 catalyst achieved a benchmark current density of 10 mA/cm2 for H2 evolution at an overpotential of 297 mV vs. RHE which further improved to 190 mV vs. RHE under illumination. This work provides valuable insights on partial Co incorporation at the B-site of LaFeO3 for the development of visible-light-induced photocatalytic and electrocatalytic systems, which is hoped to contribute to the advancement of sustainable energy production and environmental remediation. © 2024, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
Defect-engineered single crystal Bi2Te3 via Sb and Se doping for enhanced thermoelectric performance
(Springer, 2025) Puthran, S.; Hegde, G.S.; Prabhu, A.N.; Wang, Y.-L.; Kuo, Y.K.; Joshi, S.; Udayashankar, N.K.; Nayak, R.
The limitation of the single crystal melt growth method to tune the microstructure of the materials in a controlled way and the need for enhancing the thermoelectric properties of single crystal grown Bismuth telluride (Bi2Te3), through defect and microstructural engineering, has motivated this work. In this work, we address this limitation through a controlled doping strategy using antimony (Sb) and selenium (Se) to introduce targeted defects and microstructural modifications within single-crystalline Bi2Te3. Sb and Se substitutions create atomic scale strain, point defects, and micro-grain structures, enhancing phonon scattering without significantly disrupting the crystalline order. The resulting defect-engineered single crystals exhibit improved thermoelectric performance, with a notable reduction in lattice thermal conductivity and retention of excellent electrical properties. The co-doped compositions, Bi2Te2.7Se0.3 and (Bi0.98Sb0.02)2Te2.7Se0.3, exhibited significantly enhanced thermoelectric performance, with Seebeck coefficients reaching ~ 253 ?V/K and ? 211 ?V/K, respectively, over the 10–400 K range. The power factor improved remarkably, showing a ~ 30-fold increase for Bi2Te2.7Se0.3 and ~ 20-fold for the Sb-doped variant, while the figure of merit (ZT) improved by ~ 28.5 and ~ 14 times, respectively. Further, a flexible thermoelectric device fabricated from these optimized materials generated output power of 2.7 nW and 3.35 nW at ambient temperature. The non-monotonic variation of the Seebeck coefficient with Sb content, showing an optimal enhancement at x = 0.04, highlights the delicate balance between carrier concentration and band structure modification, emphasizing moderate Sb substitution achieves the most favorable conditions for thermoelectric performance. Our results present a scalable strategy for bridging the performance gap between pristine single crystals and heavily nanostructured thermoelectrics, opening new avenues for high-efficiency energy harvesting devices. © The Author(s) 2025.
Defects Enriched p-type Zinc Stannate for Selective Detection of ppb-Level NO2 Gas at Ambient Temperature
(American Chemical Society, 2024) Pawar, N.; Nath, V.G.; Rodney, J.D.; Joshi, S.; Subramanian, A.; Udayashankar, N.K.
In this study, we explore the synthesis and gas-sensing capabilities of zinc stannate (Zn2SnO4) in three morphologies─spherical nanoparticles, urchins, and octahedrons─aiming to investigate the influence of morphology on sensing properties. The fabricated devices exhibit a significant resistance decrease upon exposure to NO2 at room temperature (24 °C), indicating p-type sensing behavior. Among these morphologies, the spherical nanoparticle-based sensor exhibits the highest sensor response of 57% to 6 ppm of NO2, outperforming urchins and octahedrons by approximately 1.2 and 4.1 times, respectively. This superior performance, with response and recovery times of 6.3 s and 224 s, is attributed to enhanced redox reactions from a larger surface area and a higher proportion of oxygen interstitials. The spherical nanoparticle-based sensor also demonstrates exceptional selectivity for NO2 over SO2, CO, NH3, and CH4, with a detection limit of 200 ppb. Furthermore, the sensor exhibits excellent reversibility with only 2% variation across 20 consecutive test cycles and demonstrates remarkable long-term stability, with a performance fluctuation of approximately 2.3% over 63 days without significant degradation. © 2024 American Chemical Society.
Electrocatalytic synergies of melt-quenched Ni-Sn-Se-Te nanoalloy for direct seawater electrolysis
(Elsevier B.V., 2024) Rodney, J.D.; Joshi, S.; Ray, S.; Rao, L.; Deepapriya, S.; Carva, K.; Badekai Ramachandra, B.R.; Udayashankar, N.K.; Perumal, S.; Sadhana, S.; Justin Raj, C.J.; Kim, B.C.
The study focuses on the development of binary nanoalloys based on metal dichalcogenides (Sn30Se70, Ni30Te70) and quaternary nanoalloy (Ni15Sn15Se35Te35) using the melt quenching technique. The nanoalloys show extensive water splitting in fresh and real seawater. Sn30Se70-coated nickel foam achieved a benchmark current density of 349 mV for the oxygen evolution reaction (OER), while Ni15Sn15Se35Te35-coated nickel foam (NF) required only 185 mV for the hydrogen evolution reaction (HER) in 1 M KOH. The study also shows that a two-electrode system can achieve sustained total water splitting at higher current densities (1 A.cm?2). Modification with a CuSx layer over NF at the OER end facilitated faster kinetics and mitigated chlorine corrosion enabling direct seawater splitting at 1.26 V. Continuous direct splitting of seawater at 100 mA cm?2 for 120 h required only 1.88 V, showing an efficiency of 92.9 % for H2 production in real seawater. © 2024 Elsevier B.V.
Exploration of electrode-modulated memory and threshold switching behaviour in Se-Te-Sn thin film devices
(Elsevier B.V., 2024) Joshi, S.; Rodney, J.D.; James, A.; Udayashankar, N.K.
Due to their potential use in high-density, three-dimensional stackable cross-point array structures, the electrical switching ability of chalcogenide glasses has captured a lot of attention. Herein, the switching behaviour of unique Se86-xTe14Snx (x = 0, 2, 4, 6) chalcogenide glassy alloys in the form of a thin film were investigated. The electrode modulated dual functionality in switching was achieved by employing Aluminium (Al) and Silver (Ag), as top electrodes. The films with Al/Se86-xTe14Snx/Al interface exhibited memory-type switching due to the phase-changing properties of the material. The threshold voltage (Vth) decreased linearly from 12.75 V to 4.2 V at room temperature as Sn concentration in the glass increased. On the other hand, when the top electrode was replaced with Ag, the Ag/Se86-xTe14Snx/Al interface acted as a programmable metallization cell (PMC) showing threshold-switching properties. Ag/Se82Te14Sn4/Al thin film of thickness 200 nm showed promising results as a material for a unidirectional selector, due to the formation of temporary Ag filament inside chalcogenide material. The composition showed high selectivity (∼104), high endurance (>104 cycles), and low threshold voltage (∼1.6 V). The ability of the composition to exhibit electrode-dependent memory and threshold-switching phenomena makes the material an interesting case. © 2024 Elsevier B.V.
Exploring grinding and burnishing as surface post-treatment options for electron beam additive manufactured Alloy 718
(Elsevier B.V., 2020) Karthick Raaj, R.; Vijay Anirudh, P.; Karunakaran, C.; Kannan, C.; Jahagirdar, A.; Joshi, S.; Balan, A.S.S.
Numerous additive manufacturing (AM) techniques have been developed over the past decade. Features like immense freedom of intricate part design and shorter lead time make AM routes promising for a wide range of applications spanning aerospace, marine and automobile sectors. Among the various metal AM processes, Electron Beam Additive Manufacturing (EBAM) is being widely explored to realise the potential of Ni-based superalloys and Ti alloys for varied high-performance applications. A novel attempt has been made in this paper to assess the surface integrity of as-built EBAM nickel-based superalloy 718 (AB) subjected to grinding (G), Low Plasticity Burnishing (LPB) and their sequential combination. Apart from their influence on sub-surface microstructures, the effect of process variables during the above post-treatments on the residual stress profiles was also investigated. Results revealed that G + LPB results in about 0.6 ?m lower surface roughness, 17% improved microhardness compared to AB + LPB, and higher compressive surface residual stress as compared to LPB processed EBAM samples. The sequential grinding and LPB - improved microhardness, was also found to extend about 500 ?m more when compared to the LPB process. The G + LPB, which is greatly influenced by the prior grinding, smoothens the surface and thus results in a better surface finish. Highest hardness, superior surface finish, reduced porosity and improved compressive residual stress were observed in samples that adopted the AB + G + LPB sequence over other samples, with the LPB step at 40 MPa yielding the best results. © 2020 Elsevier B.V.
Foliage loss measurements of tropical trees at 35 GHz
(2008) Joshi, S.; Sancheti, S.
The presence of foliage in the propagation channel can lead to severe signal attenuation, and thus the effects of vegetation in the propagation environment need to be considered in any prediction model. In the present work, a measurement study is undertaken to quantify the attenuation caused due to tree canopies, at 35 GHz. The trees prevailing in typical Indian deserts, having variation in the leaf size and leaf density along the tree canopy are included in the study and in each case, attenuation characteristics are reported. The results presented in the paper may be of vital importance for radio cell planning operating at millimeter wave frequency. � 2008 IEEE.
Foliage loss measurements of tropical trees at 35 GHz
(2008) Joshi, S.; Sancheti, S.
The presence of foliage in the propagation channel can lead to severe signal attenuation, and thus the effects of vegetation in the propagation environment need to be considered in any prediction model. In the present work, a measurement study is undertaken to quantify the attenuation caused due to tree canopies, at 35 GHz. The trees prevailing in typical Indian deserts, having variation in the leaf size and leaf density along the tree canopy are included in the study and in each case, attenuation characteristics are reported. The results presented in the paper may be of vital importance for radio cell planning operating at millimeter wave frequency. Â© 2008 IEEE.
Growth of octahedral structured AgBiS2 single crystals and its insights on the high performance electrocatalytic hydrogen generation
(Elsevier Ltd, 2024) Jauhar, R.O.M.; Ramachandran, K.; Deepapriya, S.; Joshi, S.; Ghfar, A.A.; Rao, L.; Badekai Ramachandra, B.R.; Udayashankar, N.K.; Vadivel, V.; Raji, R.; Kim, B.C.; Rodney, J.D.
Given the enormous depletion of fossil fuels and growing environmental concerns, there is an immediate need to develop alternative and clean energy sources. Hydrogen (H2), recognized for its cleanliness and renewability, is poised to meet future energy requirements. Consequently, ongoing research is focused on the development of electro-active, durable, and cost-effective catalysts to replace expensive noble metal-based electrocatalysts. In this study, microscale AgBiS2 chalcogenide derived from a single crystal is reported as promising electrocatalysts for the Hydrogen Evolution Reaction (HER) with a remarkably low overpotential. The physico-chemical characterization of the AgBiS2 catalyst has been investigated using various analytical techniques. The synthesized AgBiS2 catalyst exhibits excellent HER activity, manifesting a low overpotential of 86 mV at a current density of 10 mA cm−2 and a Tafel slope of 44 mV dec−1, along with superior stability even after 24 h in HER at a very high current density. The developed AgBiS2 also showcased stable production when subjected to a two-electrode system. The enhanced alkaline HER activity of AgBiS2 can be attributed to its phase purity, high crystallinity, and the presence of high active sites. The observed high electrochemical performance and stability position AgBiS2 as a potential electrocatalyst for the hydrogen evolution reaction. This finding holds significant promise in the quest for efficient, durable, and economically viable catalysts to drive the shift towards clean and renewable energy sources. © 2024 Hydrogen Energy Publications LLC
Investigating the "wisdom of crowds" at scale
(2015) Mysore, A.S.; Yaligar, V.S.; Ibarra, I.A.; Simoiu, C.; Goel, S.; Arvind, R.; Sumanth, C.; Srikantan, A.; Bhargav, H.S.; Pahadia, M.; Dobhal, T.; Ahmed, A.; Shankar, M.; Agarwal, H.; Agarwal, R.; Anirudh-Kondaveeti, S.; Arun-Gokhale, S.; Attri, A.; Chandra, A.; Chilukuri, Y.; Dharmaji, S.; Garg, D.; Gupta, N.; Gupta, P.; Jacob, G.M.; Jain, S.; Joshi, S.; Khajuria, T.; Khillan, S.; Konam, S.; Kumar-Kolla, P.; Loomba, S.; Madan, R.; Maharaja, A.; Mathur, V.; Munshi, B.; Nawazish, M.; Neehar-Kurukunda, V.; Nirmal-Gavarraju, V.; Parashar, S.; Parikh, H.; Paritala, A.; Patil, A.; Phatak, R.; Pradhan, M.; Ravichander, A.; Sangeeth, K.; Sankaranarayanan, S.; Sehgal, V.; Sheshan, A.; Shibiraj, S.; Singh, A.; Singh, A.; Sinha, P.; Soni, P.; Thomas, B.; Tuteja, L.; Varma-Dattada, K.; Venkataraman, S.; Verma, P.; Yelurwar, I.
In a variety of problem domains, it has been observed that the aggregate opinions of groups are often more accurate than those of the constituent individuals, a phenomenon that has been termed the "wisdom of the crowd." Yet, perhaps surprisingly, there is still little consensus on how generally the phenomenon holds, how best to aggregate crowd judgements, and how social influence affects estimates. We investigate these questions by taking a meta wisdom of crowds approach. With a distributed team of over 100 student researchers across 17 institutions in the United States and India, we develop a large-scale online experiment to systematically study the wisdom of crowds effect for 1,000 different tasks in 50 subject domains. These tasks involve various types of knowledge (e.g., explicit knowledge, tacit knowledge, and prediction), question formats (e.g., multiple choice and point estimation), and inputs (e.g., text, audio, and video). To examine the effect of social influence, participants are randomly assigned to one of three different experiment conditions in which they see varying degrees of information on the responses of others. In this ongoing project, we are now preparing to recruit participants via Amazon's Mechanical Turk.
Investigating the "wisdom of crowds" at scale
(Association for Computing Machinery, Inc acmhelp@acm.org, 2015) Mysore, A.S.; Yaligar, V.S.; Ibarra, I.A.; Simoiu, C.; Goel, S.; Arvind, R.; Sumanth, C.; Srikantan, A.; Bhargav, H.S.; Pahadia, M.; Dobhal, T.; Ahmed, A.; Shankar, M.; Agarwal, H.; Agarwal, R.; Anirudh-Kondaveeti, S.; Arun-Gokhale, S.; Attri, A.; Chandra, A.; Chilukuri, Y.; Dharmaji, S.; Garg, D.; Gupta, N.; Gupta, P.; Jacob, G.M.; Jain, S.; Joshi, S.; Khajuria, T.; Khillan, S.; Konam, S.; Kumar-Kolla, P.; Loomba, S.; Madan, R.; Maharaja, A.; Mathur, V.; Munshi, B.; Nawazish, M.; Neehar-Kurukunda, V.; Nirmal-Gavarraju, V.; Parashar, S.; Parikh, H.; Paritala, A.; Patil, A.; Phatak, R.; Pradhan, M.; Ravichander, A.; Sangeeth, K.; Sankaranarayanan, S.; Sehgal, V.; Sheshan, A.; Shibiraj, S.; Singh, A.; Singh, A.; Sinha, P.; Soni, P.; Thomas, B.; Tuteja, L.; Varma-Dattada, K.; Venkataraman, S.; Verma, P.; Yelurwar, I.
In a variety of problem domains, it has been observed that the aggregate opinions of groups are often more accurate than those of the constituent individuals, a phenomenon that has been termed the "wisdom of the crowd." Yet, perhaps surprisingly, there is still little consensus on how generally the phenomenon holds, how best to aggregate crowd judgements, and how social influence affects estimates. We investigate these questions by taking a meta wisdom of crowds approach. With a distributed team of over 100 student researchers across 17 institutions in the United States and India, we develop a large-scale online experiment to systematically study the wisdom of crowds effect for 1,000 different tasks in 50 subject domains. These tasks involve various types of knowledge (e.g., explicit knowledge, tacit knowledge, and prediction), question formats (e.g., multiple choice and point estimation), and inputs (e.g., text, audio, and video). To examine the effect of social influence, participants are randomly assigned to one of three different experiment conditions in which they see varying degrees of information on the responses of others. In this ongoing project, we are now preparing to recruit participants via Amazon's Mechanical Turk.
Investigation of Indium doped Se-Te bulk chalcogenide glasses for electrical switching and phase changing applications
(Elsevier Ltd, 2024) Joshi, S.; Rodney, J.D.; James, A.; Behera, P.K.; Udayashankar, N.K.
Recently, Metal-doped Se-Te chalcogenides have gained a lot of interest due to their unique capacity for electrical switching, which makes them desirable for electronic applications. This study examines the electrical switching characteristics of bulk Se86−xTe14Inx (0 ≤ x ≤ 6) amorphous alloys produced by the conventional melt-mix-quench process. The samples with an Indium atomic percentage between 2 to 6 exhibited a remarkable transition from a highly resistive to a low resistive state when subjected to an electric field with a current of 1 mA, displaying quick and reversible switching behaviour. The threshold voltage (Vth) significantly dropped from 410.6 V to 49.2 V with an increase in Indium concentration. Additionally, above the specific current threshold, these bulk glasses demonstrated memory-type switching, demonstrating their potential for data storage applications. To comprehend the trend of glass forming ability, thermal stability range and Hruby's glass stability parameters, with their compositional dependency, Differential Scanning Calorimetry (DSC) was utilized. The sample Se80Te14In6 emerged to be the fastest phase-changing material, with a memory switching current threshold of Ith = 1.3 mA and a threshold voltage value of 49.2 V. To study the formation of crystallites in Se-Te-In alloy, X-ray diffraction patterns of pristine glass and the annealed sample were examined. Furthermore, temperature-dependent conductivity investigations showed a sharp rise in conductivity once the process crystallization begins (Tx), and also the threshold voltage (Vth) of the samples decreased linearly with rising temperature. Overall, this study provides valuable insights into the electrical switching behaviour and thermal properties of Se-Te-In chalcogenide glasses, enhancing their suitability in electronic devices. © 2024 Elsevier B.V.
Life cycle assessment and environmental impact of blended cementitious mortar with incinerated biomedical waste Ash as partial replacement to cement
(Elsevier Ltd, 2025) Tripathi, P.; Joshi, S.; Snehal, K.; Das, B.B.
In a sustainability-driven world, repurposing industrial byproducts into construction materials is vital for reducing environmental impact and resource conservation. Incinerated biomedical waste ash (IBWA), typically regarded as hazardous landfill waste poses significant environmental challenges. However, high calcium (?45 %) and silicate phases in IBWA contribute to hydration and pozzolanic reaction making it a potentially sustainable cementitious material. From this perspective, this study investigates the life cycle assessment and environmental impact of blended cementitious mortar incorporated with IBWA as a partial replacement for cement, focusing on its ecological and technical benefits. A cradle-to-gate life cycle assessment (LCA) confirmed that uutilization of IBWA in cementitious mortar conserves natural resources, reduces embodied energy consumption, lowers CO2 emissions, and minimizes eutrophication and human toxicity potential by capturing heavy metal within hydration products. To ensure environmental safety, TCLP-ICP-MS analysis was conducted, which affirms that IBWA leachate concentrations were well below EPA regulatory limits and further reduced during hydration, stabilizing heavy metals (Cr, Cu, Hg, Ni, Pb, etc.) in the solidified matrix. The optimal IBWA dosage of 10 % offered a balance between both technical performance and sustainability. The porous and non-spherical morphology of IBWA increased water demand and inter-particle friction, and its SiO? + CaO content (>50 %) enhanced cement hydration. Thermogravimetric analysis (TGA), Xray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) analyses confirmed the progressive formation of secondary hydration products (C-S-H, and C-A-S-H), contributing to densified microstructure (Ca/Si ratio: ?1.2). The final sustainable performance score of 0.77 for the IBWA10 mix signifies an eco-efficient and balanced formulation, offering structural integrity along with environmental and economic advantages. © 2025 Elsevier Ltd
Mechanistic insights and DFT analysis of bimetal doped styrofoam-like LaFeO3 perovskites with in-built dual redox couples for enhanced Photo-Fenton degradation of Tetracycline
(Elsevier B.V., 2024) James, A.; Naik, S.; Rodney, J.D.; Joshi, S.; Udayakumar, U.; Kim, B.C.; Udayashankar, N.K.
The rising number of contaminants released into the environment and the inadequacies of traditional wastewater treatment techniques have led to the demand for enhanced oxidation technologies like photo-Fenton. In this study, bimetal co-doped lanthanum orthoferrite (BixLa1-xCuyFe1-yO3 (x = 0, 0.01, 0.05, 0.1; y = 0, 0.01, 0.05, 0.1, 0.15)) based photo-Fenton catalysts with the in-built redox couples Fe3+/Fe2+, Cu2+/Cu+ and oxygen vacancies have been successfully synthesised via a facile one-pot solution combustion route. Systematic studies show that the Bi0.05La0.95Cu0.1Fe0.9O3 (LFOBC) exhibits an optimal photo-Fenton degradation rate of 0.0497/min for Tetracycline (TC) removal, being ∼ 1.8 and ∼ 6.2 times greater than Bi0.05La0.95FeO3 (LFOB) and pristine LaFeO3 (LFO) respectively. DFT analysis confirmed the better adsorption and dissociation of H2O2 on a bimetal co-doped catalyst and identified the electron density difference in LFOBC, which can induce the H2O2 dissociation. A detailed investigation of various influencing reaction parameters is explored. The degradation pathway for the LFOBC catalyst with the toxicological characteristics of each intermediate is analysed. This study presents the Bi0.05La0.95Cu0.1Fe0.9O3 as a potential photocatalyst for enhanced photo-Fenton degradation with excellent efficiency observed for the degradation of various harmful pollutants for environmental remediation. © 2024 Elsevier B.V.
Multipath fading characteristics of millimeter wave radio propagation in urban microcellular environment
(2008) Joshi, S.; Sancheti, S.
The frequency region 28-38 GHz has potential applications in fixed-wireless broadband services on account of availability of large spectrum and adequate device support to ease spectrum congestion problems, particularly in urban centers. This paper envisages development of a multiray propagation model to investigate multipath fading prevailing in millimeter wave radio propagation in a micro cellular environment. The model is simulated and measurements are carried out to estimate fast fading, propagation loss, and delay spread along micro cellular streets of variable width. The results depicted in the paper yields quantitative trends, with specific use in planning radio cells for fixed- wireless broadband services in urban microcellular environment. � 2008 IEEE.
Multipath fading characteristics of millimeter wave radio propagation in urban microcellular environment
(2008) Joshi, S.; Sancheti, S.
The frequency region 28-38 GHz has potential applications in fixed-wireless broadband services on account of availability of large spectrum and adequate device support to ease spectrum congestion problems, particularly in urban centers. This paper envisages development of a multiray propagation model to investigate multipath fading prevailing in millimeter wave radio propagation in a micro cellular environment. The model is simulated and measurements are carried out to estimate fast fading, propagation loss, and delay spread along micro cellular streets of variable width. The results depicted in the paper yields quantitative trends, with specific use in planning radio cells for fixed- wireless broadband services in urban microcellular environment. Â© 2008 IEEE.
Network Science based Predictive Analysis on Social Media Data
(Institute of Electrical and Electronics Engineers Inc., 2023) Joshi, S.; Kamath Sâ€¤, S.
Traditional approaches utilizing machine learning algorithms have limitations in capturing the full depth and semantic nuances of text, hindering comprehensive analysis for tasks like opinion mining, sentiment analysis, population health analytics etc. To overcome these limitations, we propose the integration of graph analysis and Social Network Analysis (SNA) techniques to enhance the informative value of tweet analysis and facilitate the extraction of structured knowledge from textual and visual content. This work focuses on modeling user-generated content on Twitter to enable intelligent population analytics applications in the healthcare domain. Standard datasets comprising user details and their tweets are considered for the experiments, which are transformed into graph representations suitable for both structural and behavioral analytics. Additionally, a comparative study to assess the impact of varying network sizes by manipulating the number of nodes within the network is conducted. To evaluate the network properties, different centrality measures were employed and compared. Â© 2023 IEEE.