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Modified carbon substrates for electrocatalytic oxidation of selected heterocyclic carbinols
Electrochemically modified carbon electrodes are used as a substrate for electrocatalytic oxidation of different heterocyclic carbinols. Carbon fiber paper (CFP) is newlineused as the electrode substrate on which various modifications are employed. Modified newlineelectrodes were prepared by using different surface modification strategies such as newlineelectrodeposition of Pd nanoparticles or Pd-Pt bimetallic nanoparticles on a conducting newlinepolymer, polyaniline which is electropolymerized on to CFP. Biomass derived porous carbon nanoparticle coated CFP was also used for electrodeposition of Pd nanoparticles or MnO2-Pi nanoparticles. These modified electrodes were physicochemically characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM) with energy-dispersive X-ray spectroscopy (EDS), Transmission electron microscopy (TEM), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Optical profilometry and X-ray photoelectron spectroscopy (XPS) and electrochemically characterized using Cyclic voltammetry (CV) and Electrochemical impedance spectroscopy (EIS). This modification methods have attracted a lot of attention due to their exceptional stability, high electronic conductivity, mechanical strength, and good adhesive property to the substrate and to the modified electrode. The modified electrodes show excellent electrochemical and newlinephysicochemical properties which are demonstrated using various analytical techniques. The organocatalytic reagent, TEMPO is used as a mediator throughout the studies which helps to carry out the oxidation of organic molecules in an aqueous acidic medium. The developed electrodes have been successfully applied for the oxidation of different heterocyclic alcohol such as 4-pyridinemethanol, 2-thiophene methanol, and 2-Furfuryl alcohol to corresponding 4-pyridinemethanal, 2-thiophene methanol and 2-Furfural. -
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Modified Carbon-Based Composites and Their Electrochemical Studies
Energy storage has emerged as the world's most important issue, attracting the focus of researchers and commercial developers due to the economy's rapid growth and the rise in the usage of portable electronics and electronic vehicles. These devices make it possible to efficiently capture and store the excess energy produced during times of high generation, so that it can be used when there is little or no generation. Devices for storing renewable energy contribute to grid stability and lessen the reliance on fossil fuel-based power plants. Moreover, they contribute to the decarbonization of the energy industry, mitigating climate change, and promoting a sustainable future. This thesis explores the potential of modified carbon-based composites as advanced materials for energy storage applications particularly supercapacitors and solar thermal fuels. The research focuses on the careful design and synthesis of ternary composites, incorporating carbonaceous materials such as carbon nanotubes, graphene oxide, and graphitic carbon nitrides, metal sulphides, nitrogen rich moieties, and conductive additives like polyaniline and polypyrrole. A wide variety of methodologies were used to describe the structural and morphological characteristics of the composite materials. Thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and other techniques were used. These methods gave important information about the composite materials' chemical structure, type of bonding and arrangements, surface morphology, and thermal stability. Electrochemical techniques, such as cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy, have been extensively employed to investigate the performance and behaviour of supercapacitor electrodes and devices. The results demonstrate significant improvements in electrochemical performance, including enhanced specific capacitance, excellent cycling stability, and remarkable rate capability. These findings indicate that the modified carbon-based ternary composites hold promise for high-performance energy storage devices. Ultimately, this research contributes to the development of next-generation energy storage technologies, offering more efficient and sustainable solutions for storing energy. -
Modified Ceria as a Substitute for Sulfuric Acid in the Liquid Phase Nitration of Toluene
Reaction, Kinetics, Mechanisms and Catalysis, ISSN NO. 1878-5204 -
Modified ceria as a substitute for sulfuric acid in the liquid phase nitration of toluene
Ceria, sulfated ceria, ceria-zirconia and sulfated ceria-zirconia catalysts were prepared via the co-precipitation method and calcined at 823 K. The catalysts were characterized by XRD, BET surface area, FTIR, TGA and EDAX. The acidity of the catalysts was studied by pyridine adsorbed FTIR. All the peaks in XRD correspond to the cubic fluorite structure of ceria. The crystallite size of the catalysts was found to be 4-8 nm. Incorporation of zirconia stabilizes the surface sulfate species and thus increases the sulfate content. Sulfation decreases the surface area, but increases the acidity, leading to enhanced catalytic activity. All the catalysts were found to be stable up to 923 K. Catalytic activities were tested towards the liquid phase nitration of toluene. A maximum conversion of about 34 % is achievable for the nitration of toluene to dinitrotoluene. Solid acids effectively play the role of sulfuric acid in the reaction, assisting the formation of nitronium species. 2012 Akadiai Kiad Budapest, Hungary. -
Modified eco-friendly and biodegradable chitosan-based sustainable semiconducting thin films
Semiconducting materials are pivotal in various fields, such as solar cells, LEDs, photovoltaic cells, etc. A nature-friendly chitosan is a good film-forming, water-soluble polymer that is modified to a small band-gap polymer for various optoelectronic applications. Choline chloride:ethylene glycol:glycerin (1:1:1) deep eutectic solvent (DES)-modified activated carbon is incorporated into the chitosan matric and this composite is fabricated into thin films via spin coating methodology. The obtained films are subjected to multiple studies such as scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), impedance spectroscopy, and UVvis spectroscopy to perceive the thin-films microstructure, morphology, conductance, band gap, and optical nature. The integration of DES-modified activated carbon has significantly improved the charge transfer capacity of chitosan by reducing the band gap from 4.0 to 2.0 eV. These notable characteristics exhibited by the modified films can be key to sustainable semiconducting materials and have the potential to transform several optoelectronic applications. 2024 The Author(s). Polymers for Advanced Technologies published by John Wiley & Sons Ltd. -
Modified Genesio-Tesi systems with trigonometric functions and the Caputo fractional derivative
The new fractional-order Genesio-Tesi system is introduced, and its boundedness, stability of the equilibrium points, Lyapunov stability, uniqueness of the solution, and bifurcation are all discussed in this paper. Using the efficient predictor-corrector approach, we statistically analyze the Genesio-Tesi system in fractional order. The results effectively conceptualize and visualize the novel fractional order Genesio-Tesi systems that are suggested. When the systems order shifts from integer to fractional, the revolution around the fixed point increases. The chaotic character of the modified Genesio-Tesi system is comparable to that of the original Genesio system. The major changes were made to the Geensio-Tesi system by including the trigonometric functions, keeping the initial conditions and parameter values intact. The system is fractionalised with the help of Caputo fractional operator. In particular, the modified systems nature is more complex, which may aid in signal processing and secure communication. Future research on the modified Genesio-Tesi system can now proceed in light of this finding. This article offers a fresh approach to utilizing and thoroughly researching the Genesio-Tesi systems that have been provided. CSP - Cambridge, UK; I&S - Florida, USA, 2024 -
Modified Metal Organic Frameworks for Electrocatalytic Water Splitting and Energy Storage Applications
Metal-organic frameworks (MOFs) are a class of crystalline material formed by the newlinecombination of metal ions/clusters along with organic linkers. This work is mainly based on newlinesynthesizing MOFs and their application in electrocatalytic water splitting and newlinesupercapacitors. The MOFs synthesized in the present work are Ni-Cu, {Mn-NiNH2(h2fipbb)}, Mn-MOF/rGO, and Sm-MOF/rGO/PANI using different ditopic and tritopic linkers. Using various characterization techniques, the formation of the synthesized MOFs is confirmed. The increasing use of fossil fuels now contributes to a number of environmental problems, including climate change and global warming. High-performance electrochemical energy storage devices are essential for portable electronics, electric cars, newlineand renewable energy storage medium, driving demand. MOFs are emerged as a promising newlinecontender for energy storage applications owing to their novel microstructures, atomically dispersed metal centers, and earth-abundant metal components. Electrochemical water splitting is a crucial approach in the pursuit of producing environmentally friendly fuels such newlineas H2 and O2, reducing our dependence on traditional fossil fuels while promoting newlinesustainable and clean energy sources. In order to produce hydrogen with the best efficiency and lowest cost, these MOFs are used. Electrochemical studies like cyclic voltammetry, galvanostatic charge discharge, and electrochemical impedance spectroscopy reveal that the prepared MOFs can be used as supercapacitors. Linear sweep voltammetry and Tafel plot determine the performance of these MOFs towards water splitting studies. Supercapacitors, which are electrochemical capacitors, are popular energy storage devices with quick charge rate, high power density, excellent rate capability, and outstanding life expectancy. -
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Modified Montmorillonite Catalysed Ultrasonic Assisted one-pot Synthesis of Novel 2,3-dihydroisoxazolo[5,4-d] pyrimidin-4(7H)-ones as Potential Anticancer Agents
The development of novel compounds with potential anticancer activity is imperative for combating the challenges posed by cancer. In this study, a modified montmorillonite based catalyst is employed for the synthesis of 2,3-dihydroisoxazolo[5,4-d] pyrimidin-4(7H)-ones, which are promising candidates for anticancer agents. Montmorillonite is modified using mixed metal oxides, typically Al2O3 and CeO2, by a facile approach followed by standard spectroscopic and electron microscopic characterizations. It is then employed for the one-pot synthesis of a series of 2,3-dihydroisoxazolo[5,4-d] pyrimidin-4(7H)-ones. The synthesis protocol, mediated by ultrasound, is simple, efficient, and environment friendly. The mixed metal oxide pillared montmorillonite catalyst exhibits high catalytic activity and selectivity, facilitating the formation of the desired compounds in good to excellent yields. The synthesized compounds are characterized using various spectroscopic techniques such as 1H NMR, 13C NMR and mass spectrometry. Furthermore, the anticancer activity of the synthesized compounds is evaluated against a series of cancer cell lines, revealing promising cytotoxic effects. The findings of this study highlight the potential of novel 2,3-dihydroisoxazolo[5,4-d] pyrimidin-4(7H)-ones as promising anticancer agent, warranting further investigation for their therapeutic potential. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024. -
Modified Non-local Means Model for Speckle Noise Reduction in Ultrasound Images
In the modern health care field, various medical imaging modalities play a vital role in diagnosis. Among the modalities, Medical Ultrasound Imaging is the most popular and economic modality. But its vulnerability to multiplicative speckle noise is challenging, which obscure accurate diagnosis. To reduce the influence of the speckle noise, various noise filtering models have been proposed. But while filtering the noise, these filters exhibit limitations like high computational complexity and loss of detailed structures and edges of organs. In this article, a novel Non-local means (NLM)-based model is proposed for the speckle reduction of Ultrasound images. The design parameters of the NLM filter are obtained by applying the Grey Wolf Optimization (GWO) to the input image. The optimized parameters and the noisy image are passed to the NLM filter to get the denoised image. The efficiency of this proposed method is evaluated with standard performance metrics. A comparative analysis with existing methods highlights the merit of the proposal. 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. -
Modified PredictorCorrector Method for the Numerical Solution of a Fractional-Order SIR Model with 2019-nCoV
In this paper, we analyzed and found the solution for a suitable nonlinear fractional dynamical system that describes coronavirus (2019-nCoV) using a novel computational method. A compartmental model with four compartments, namely, susceptible, infected, reported and unreported, was adopted and modified to a new model incorporating fractional operators. In particular, by using a modified predictorcorrector method, we captured the nature of the obtained solution for different arbitrary orders. We investigated the influence of the fractional operator to present and discuss some interesting properties of the novel coronavirus infection. 2022 by the authors. Licensee MDPI, Basel, Switzerland. -
Modified Rice Husk Silica from Biowaste: An Efficient Catalyst for Transesterification of Diethyl Malonate and Benzyl Alcohol
Abstract: Molybdenum and lanthanum oxide modified silica-based catalysts were prepared from the agricultural waste rice husk. These synthesized catalysts were characterized by various spectroscopic and non-spectroscopic techniques. The catalytic performance was investigated by transesterification reaction between diethyl malonate and benzyl alcohol in the liquid phase using modified silica as a heterogeneous catalyst. Molybdenum modified silica-based catalyst showed the highest conversion efficiency of 95.6% and selectivity of 96.8% for dibenzyl malonate. The reaction conditions were optimized to give maximum efficiency with the highest selectivity in a solvent-free green method. Graphic Abstract: [Figure not available: see fulltext.]. 2019, Springer Nature B.V. -
Modulated Rayleigh-benard ferroconvection in couple stress fluid
Ferromagnetic fluid with couple-stress confined between two stress-free, isothermal horizontal plates is considered in this study. The effect of different types of modulation on Rayleigh-Bénard convection in a ferromagnetic fluid with couple-stress is examined by considering sinusoidal (sine) and non-sinusoidal (square, triangular, and sawtooth) wave type of modulation. Rayleigh-Bénard convection in a ferromagnetic fluid with couple-stress subjected to gravity, rotation, temperature, and internal heat modulation is discussed by performing linear and non-linear analyses. The effect of various parameters on the onset of convection and heat transport is studied. The ferromagnetic parameters hasten the convection onset and enhance the heat transfer under various modulations. The results of a Newtonian fluid, ferromagnetic fluid, and couple-stress fluid are obtained as the limiting cases of this study. -
Modulated rayleigh-benard ferroconvection in couple stress fluid
Ferromagnetic fluid with couple stress confined between two stress-free, isothermal horizontal plates is considered in this study. The effect of different types of modulation on Rayleigh-Bard convection in a ferromagnetic fluid with couple stress is examined by considering sinusoidal (sine) and non-sinusoidal (square, triangular, and sawtooth) wave types of modulation. Rayleigh- Bard convection in a ferromagnetic fluid with couple stress subjected to gravity, rotation, temperature, and internal heat modulation is discussed by performing linear and non-linear analyses. The expression for the critical Rayleigh number and the correction Rayleigh number are deduced using the Venezian approach. The effect of gravity, rotation, temperature and internal heat modulation on heat transport is studied using the generalized Lorenz model. The effect of various parameters on the onset of convection and heat transport is studied. The ferromagnetic parameters hasten the convection onset and enhance the heat transfer under various modulations. The results of a Newtonian fluid, ferromagnetic fluid, and couple stress fluid is obtained as the limiting cases of this study. -
Modulating Electrochemical Energy Storage Properties of Cassava Peel-Derived Carbon Dots Via Solvent Engineering
Despite their small size, constrained within a few nanometers, Carbon dots, the tiny 0D materials, have the potential to revolutionize the realm of materials, design, and technology. The elemental composition of carbon dots, more specifically, the non-carbon elements forming functional groups, has crucial roles in determining the structure and properties, opening a wide scope for tailoring through compositional engineering. In this work, tuned carbon dots derived from waste Cassava peel, synthesized by applying solvent engineering strategy in facile single-step microwave-assisted solvothermal treatment, are reported. The proportion of charge accumulation mechanisms is found to be highly dependent on the elemental composition of oxygen and nitrogen in the carbon dots, evidencing the pivotal role of functional groups. Among the carbon dots synthesized using three different solvents. Ethylenediamine based ones show highest energy storage capability (114.57Fg?1 at 0.1Ag?1) owing to nitrogen-oxygen co-functionalization. Though these carbon dots have low storage capabilities as such, they have potential prospects to be incorporated into electrode materials to tune charge storage mechanisms desirably, often with the added advantage of enhanced stability and performance. Additionally, the redox properties exhibited by the tuned samples give promising prospects toward applications like electrochemical sensing and electrolyte engineering for energy storage. 2025 Wiley-VCH GmbH. -
MOF derived cobalt-phospho-boride for rapid hydrogen generation via NaBH4 hydrolysis
Developing effective transition metal catalysts that can replace precious metal-based catalysts for hydrogen generation from the hydrolysis of chemical hydride has attracted extensive interest. This study focuses on synthesizing cobalt phospho-boride (CoPB) within a metal-organic framework (MOF) framework using hydrothermal and chemical reduction methodologies. Incorporating boron and phosphorous into Co-MOF enhances the hydrogen generation rate, reaching 1.8 L/min/g and 3.6 L/min/g for CoB-MOF and CoPB-MOF, respectively, during NaBH4 hydrolysis. Along with the nanostructured morphology of MOF, the electron modulation around Co-sites due to the presence of P and B creates a synergic effect to produce this high H2 generation rate and very low activation energy of 20.7 kJ/mol. The kinetic studies on NaBH4 hydrolysis reaction revealed zero-order kinetics with respect to NaBH4 concentration for CoPB-MOF, where porous morphology renders facile movement of BH4? ions to the active sites. The heat treatment at 773 K in the N2 atmosphere did not show any significant fall in the activity of CoPB-MOF, thus showcasing its robust nature. Moreover, the present catalyst also displayed recycling behavior with no signs of deactivation. 2024 Hydrogen Energy Publications LLC -
Moisture-Sensitive Fe2O3 Nanoparticle-Based Magnetic Soft Actuators
Multifunctional soft robots are emerging as a new-generation intelligent device for challenging environments. To meet the requirements of smart applications and soft robotics, developing a soft actuator capable of multiple functions and mechanical deformation is essential. In this study, we designed a free-standing magnetic soft actuator constructed from iron oxide (Fe2O3) nanoparticles and poly(vinyl alcohol) (PVA), that responds to both moisture and magnetic fields. We used computational modeling (density functional theory and ab initio molecular dynamics) to explain the experimental findings demonstrating the deformation and high-bending angle (?150), which is about twice as large under combined moisture and magnetic field exposure compared to their individual effect. Additionally, a flower-shaped soft robot was designed by using the continuous bending deformation of the actuator in response to moisture changes, performing directional bending in an ambient environment. These findings demonstrate the materials sensitivity to moisture and magnetic fields, opening up new possibilities for designing responsive structures in the smart device industry. 2024 American Chemical Society. -
Molecular and electronic structure of 5-coordinated [Fe(CO)?(X?)] complexes: A quantum chemical study
Quantum mechanical DFT calculations were performed on Fe(CO)5 and for the axial and equatorial isomers of 5-coordinated [Fe(CO)4(X2)] (where X = N, P, As, and Sb) complexes. The equatorially substituted complexes of 5-coordinated [Fe(CO)4(X2)] are more stable than the axially substituted complexes, as seen from their energy values. These complexes were further studied to understand their bonding nature using results from Natural population analysis (NPA) and energy decomposition analysis (EDA) calculations. The Wiberg bond indices (WBI) analysis provides the bond index of the bond between Fe and X2. The Frontier molecular orbital (FMO) studies show these complexes have a HOMO-LUMO energy gap in the values ranging from 1.99 to 5.04 eV, which is less than that of [Fe(CO)5]. From the Natural bond order (NBO) analysis, the contribution of the X?-atom is smaller in the ? bond formation compared to X? in P2, As2, and Sb2. Similar contributions are seen with the carbonyl group (in the Fe[sbnd]C bond), although the contribution of the carbon atom is larger than that of the X atom. 2025 Elsevier B.V.