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On thermal performance of spine fin in magnetized hybrid fluid rooted with Cu and MoS4 nanoparticles
This study examines the thermal performance of diverse profiles of spine fins with variable thermal conductivity. A hybrid nanofluid comprising Cu, and MoS4 with water as the base fluid, is modeled mathematically. Both the cylindrical and concave parabolic profiles are taken into account. The comparative outcomes are inferred from numerical and semi-analytical methods. The non-dimensional temperature profiles are analyzed graphically while considering the fin tip to be insulated, and the effects of various thermal parameters are also investigated. We have observed that the heat transfer rate shows an opposite trend toward convective-conduction and porosity parameter. The study also revealed that the concave parabolic profile emits more heat in comparison with the cylindrical profile. 2024 Author(s). -
ON TRANSFORMED GRAPHS
The network systems and graphical analysis through the study of structural characteristics is a vast field of growing importance in research. Topological indices have a significant and crucial role in the study of structureproperty relationships. In this paper, we examine constructional transformed networks constructed by unique vertex-edge incidence and mutual adjacency associations. Expressions for the first and second hyper Zagreb indices and co-indices of these transformed networks and their complements are obtained. 2023, RAMANUJAN SOCIETY OF MATHEMATICS AND MATHEMATICAL SCIENCES. All rights reserved. -
On Two-Dimensional Approximate Pattern Matching Using Fuzzy Automata
Pattern matching has been extensively studied in the last few decades, owing to its great contribution in various fields such as search engines, computational biology, etc. Several real-life situations require patterns that allow ambiguity in specified positions. In this paper, one-dimensional and two-dimensional approximate pattern matching models have been constructed using fuzzy automata. The similarity function used in fuzzy automata enables the occurrence of all exact and similar one-dimensional and two-dimensional patterns. This kind of searching approximate patterns is not possible with regular search models. The time complexity of the proposed algorithm has also been analyzed. The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024. -
On Πk – connectivity of some product graphs
Vol. 21, No.2, 70 - 79 ISSN 13105132 -
On-board Converter for Electric Vehicle Charging using LCLC Resonant Topology
Due to their high efficiency, high power density, and soft switching characteristics, LLC-based AC-DC resonant converters are a great choice for EV chargers. Adding a capacitor across the magnetizing inductance of the LLC resonant architecture (LCLC configuration) enhances efficiency and reduces the need for a larger series inductor. The output DC voltage of the converter is generally regulated using switching frequency control. However, the power factor of the converter varies significantly with the switching frequency. As a result, any fluctuations in load may cause the converter to operate at a lower power factor. This paper proposes a single-stage topology based on the LCLC resonant structure. Zero voltage switching (ZVS) of the IGBTs used in the converter is ensured by the LCLC resonant configuration. Converter have a power factor correction (PFC) stage on the front of the converter to achieve natural power factor correction. Since the PFC stage and the resonant stage are controlled by the same switches, the converter is smaller and less costly. Simulations in MATLAB/Simulink are used to validate the topology. 2023 IEEE. -
On-off fluorescence detection of exposed phosgene via pyrazine ring formation on a triphenyl amine backbone supplemented with a theoretical approach and practical environmental applications
Using 4-(diphenylamino)benzaldehyde as the fluorophore and 2,3-diaminomaleonitrile, a fluorescent probe known as 2-amino-3-(((E)-4-(diphenylamino)benzylidene)amino)-maleonitrile (ADM) has been developed for the selective detection of phosgene through a unique cyclization pathway producing a substituted pyrazine derivative attached to a triphenyl amine backbone. This reaction led to a notable reduction in the emission intensity of ADM at 565 nm. This is the first study that reports ADM as a sensory material for the selective detection of phosgene, achieved by forming a new heterocyclic pyrazine structure. With a quick response time of only 80 seconds, the detection limit of the probe ADM towards phosgene has been calculated as 4.23 ?M. Several spectroscopic methods, including UV-vis, emission spectroscopy, mass spectrometry, and computational investigations are used to study the sensing behavior. In practical applications, the sensor ADM can be used for soil analysis, the dipstick method, and the detection of phosgene from chlorinated hydrocarbon sources such as dichloromethane, chloroform and household solvents like paint remover. 2024 The Royal Society of Chemistry. -
One Pot Hydrothermal Synthesis and Application of Bright-yellow-emissive Carbon Quantum Dots in Hg2+ Detection
Carbon quantum dots (CQD) have drawn great interest worldwide for their extensive application as sensors due to their extraordinary physical and chemical characteristics, good biocompatibility, and high fluorescence in nature. Here, we demonstrate a technique for detecting mercury (Hg2+) ion using a fluorescent CQD probe. Ecology is concerned about the accumulation of heavy metal ions in water samples due to their harmful effects on human health. Sensitive identification and removal of metal ions from water samples are required to reduce heavy metals risk. To find out Mercury in the water sample, carbon quantum dots were used and synthesized by 5-dimethyl amino methyl furfuryl alcohol and o-phenylene diamine through the hydrothermal technique. The synthesized CQD shows yellow emission when exposed to UV irradiation. Mercury ion was used to quench carbon quantum dots, and it was found that the detection limit was 5.2 nM with a linear range of 15100 M. The synthesized carbon quantum dots were demonstrated to efficiently detect Mercury ions in real water samples. 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature. -
One Time Password-Based Two Channel Authentication MechanismUsing Blockchain
Using Fog Nodes, also known as IOT devices are increasing everyday with more and more home automation, industry automation, automobile automation, etc. Security threats for these devices are also increasing. One of the threats is impersonating one fog node, stealing data and taking control of the network which is also known as the Sybil attack. To provide security, most fog devices use one step or two step authentication and sometimes use encryption. With static passwords, there is a chance of compromise by password sharing and leaking. Some weak encryption algorithms used are also compromised. Data about fog nodes in the network is stored in a weak database and is tampered. OTP-based Two Channel Authentication Mechanism (OTPTAM) to authenticate the fog nodes with metadata stored in Blockchain Database and communicate using channels encrypted with Elliptical Ciphers can solve the majority of these problems. Metadata of the nodes like Bluetooth MAC address, network mac address, telephone number are all stored in the blockchain and the OTP is exchanged via these channels to ensure the authenticity of the fog nodes. 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. -
One-pot hydrothermal synthesis of 3D garland BiOI, spherical ZnO, and CNFs onto Ni foam: Supercapacitor performance with enhanced electrochemical properties
This study reported one-pot hydrothermal synthesis of 3D garland BiOI, spherical ZnO, and carbon nanofibers (CNFs) onto Ni foam substrate with improved supercapacitor performance and enhanced electrochemical properties. The synthesized nanocomposites exhibited high specific capacitance (SC) of 1073 g?1 at a current density of 1 A/g and excellent cycling stability with 88.6% retention of original capacity after 5000 cycles in 2M KOH aqueous solution. The findings highlight the potential of 3D materials for use as electrode materials in advanced supercapacitor applications due to their high energy storage capabilities. 2024 Elsevier Ltd -
One-pot hydrothermal synthesis of MWCNTs/NiS/graphitic carbon nitride as next generation asymmetric supercapacitors
Fabricating new electrode materials with high capacitive properties is crucial in contemporary research. The construction of hybrid supercapacitors developed using transition metal-sulfides and carbonaceous materials provides significant surface area and distinctive charge storage characteristics. In the present work, NH2-multiwalled carbon nanotubes/NiS/g-C3N4 (MNG) hybrid was synthesized by a one-pot hydrothermal method, and pristine g-C3N4 using thermal method. The morphological studies of the hybrid materials show the presence of tube like MWCNTs, sphere-like NiS, and sheet like g-C3N4. The uniform distribution of all the components in the hybrid helps in exhibiting excellent electrochemical performances. The prepared electrode material shows a specific capacitance of 2432 F g?1 at a current density of 4 A g?1. Furthermore, following a series of 10,000 cycling tests, the hybrid ternary composite retains 98 % of its initial capacitance. An asymmetric coin cell of MNG//AC was fabricated with an exceptional energy density of 73.3 Wh kg?1 and a power density of 1599.2 W kg?1. This remarkable rate performance and cycle stability exhibited by the material indicate its potential as a highly efficient electrode material for supercapacitors. 2024 Elsevier B.V. -
One-pot sustainable synthesis of novel pyrido[2,3-d]pyrimidinones and their evaluation for antitubercular and anticancer activity
A novel green protocol for the construction of diversified pyrido[2,3-d]pyrimidinones was accomplished by a single-pot reaction of aryl aldehydes, Meldrum's acid, thiobarbituric acid, and ammonium acetate/aniline in H2O using ?-proline as an expeditious reusable catalyst at room temperature (26 C). Our strategy provides an innovative synthetic avenue for the construction of pyrido[2,3-d]pyrimidinones, as well as several advantages over traditional methods, including a simple procedure, shorter reaction duration, excellent yields, safe handling, easy workup, catalyst recovery, and environmental compatibility. Furthermore, the synthesised compounds were tested for their impact on different cell lines and microorganisms. Compounds 5d and 5e were particularly effective against Mycobacterium tuberculosis (antitubercular), human breast cancer cells (MCF-7), lung cancer cells (A549 and NCI-H460), and both Gram-positive (S. pyogenes) and Gram-negative (E. coli) bacteria. The derivatives with hydroxyl and nitro substitutions [5e, 5f] showed the highest potency against MCF-7, A549, and NCI-H460 cell lines, with IC50 values of 3.684.36, 3.823.41, and 11.3412.28 g/mL, respectively. 2024 The Author(s) -
One-Pot Synthesis of Silver Nanoparticles Derived from Aqueous Leaf Extract of Ageratum conyzoides and Their Biological Efficacy
The main objective of the present research work is to assess the biological properties of the aqueous plant extract (ACAE) synthesised silver nanoparticles from the herbal plant Ageratum conyzoides, and their biological applications. The silver nanoparticle syntheses from Ageratum conyzoides (Ac-AgNPs) were optimised with different parameters, such as pH (2, 4, 6, 8 and 10) and varied silver nitrate concentration (1 mM and 5 mM). Based on the UVvis spectroscopy analysis of the synthesised silver nanoparticles, the concentration of 5 mM with the pH at 8 was recorded as the peak reduction at 400 nm; and these conditions were optimized were used for further studies. The results of the FE-SEM analysis recorded the size ranges (~3090 nm), and irregular spherical and triangular shapes of the AC-AgNPs were captured. The characterization reports of the HR-TEM investigation of AC-AgNPs were also in line with the FE-SEM studies. The antibacterial efficacies of AC-AgNPs have revealed the maximum zone of inhibition against S. typhi to be within 20 mm. The in vitro antiplasmodial activity of AC-AgNPs is shown to have an effective antiplasmodial property (IC50:17.65 ?g/mL), whereas AgNO3 has shown a minimum level of IC50: value 68.03 ?g/mL, and the Ac-AE showed >100 ?g/mL at 24 h of parasitaemia suppression. The ?-amylase inhibitory properties of AC-AgNPs have revealed a maximum inhibition similar to the control Acarbose (IC50: 10.87 ?g/mL). The antioxidant activity of the AC-AgNPs have revealed a better property (87.86% 0.56, 85.95% 1.02 and 90.11 0.29%) when compared with the Ac-AE and standard in all the three different tests, such as DPPH, FRAP and H2O2 scavenging assay, respectively. The current research work might be a baseline for the future drug expansion process in the area of nano-drug design, and its applications also has a lot of economic viability and is a safer method in synthesising or producing silver nanoparticles. 2023 by the authors. -
One-Pot Synthesis of Silver Nanoparticles from Garcinia gummi-gutta: Characterisation, Antimicrobial, Antioxidant, Anti-Cancerous and Photocatalytic Applications
Background: Methods like the bio-synthesis of silver nanoparticles (Ag NPs) using plant extracts have become promising due to their eco-friendly approach. The study aimed to examine the utilization of Garcinia gummi-gutta fruit phytochemicals as agents in the biosynthesis of Ag NPs, evaluation of the antimicrobial, antioxidant, and anti-cancerous properties, as well as the photocatalytic ability of bio-synthesized Ag NPs against Crystal Violet (CV), a triphenylmethane dye. Methods: The characterization of the physical properties of the Ag NPs synthesized via the green route was done using UVVis spectrophotometry (UVVis), X-ray Diffraction (XRD), Fourier Transform Infrared Spectrophotometry (FTIR), Scanning Electron Microscopy (SEM), Zeta potential analysis, and Transmission Electron Microscopy (TEM). The dye degradation efficiency of CV was determined using synthesized Ag NPs under UV light by analyzing the absorption maximum at 579 nm. The antimicrobial efficacy of Ag NPs against E. coli, S. aureus, Candida tropicalis, and Candida albicans was examined using the broth dilution method. The antioxidant and anti-cancer properties of the synthesized Ag NPs were assessed using the DPPH and MTT assays. Results: The UV analysis revealed that the peak of synthesized Ag NPs was 442 nm. Data from FTIR, XRD, Zeta potential, SEM, and TEM analysis confirmed the formation of nanoparticles. The SEM and TEM analysis identified the presence of spherical nanoparticles with an average size of 29.12 nm and 24.18 nm, respectively. Maximum dye degradation efficiency of CV was observed at 90.08% after 320 min without any silver leaching, confirming the photocatalytic activity of Ag NPs. The bio-efficiency of the treatment was assessed using the Allium cepa root growth inhibition test, toxicity analysis on Vigna radiata, and Brine shrimp lethality assay. Conclusions: The findings revealed the environmentally friendly nature of green Ag NPs over physical/chemically synthesized Ag NPs. The synthesized Ag NPs can effectively be used in biomedical and photocatalytic applications. Copyright: 2023 The Author(s). -
One-step synthesized Pt-dispersed N, P co-doped graphene as an efficient oxygen reduction reaction ORR electrocatalyst
A simple yet effective strategy to simultaneously deposit Platinum and co-doped (Nitrogen & Phosphorous) graphite oxide (rGO) using microwave irradiation has been carried out, labeled as Pt/NP-rGO. The successful deposition of Pt was confirmed using X-ray diffractogram (XRD), transmission electron microscope (TEM), and selected area electron diffraction (SAED) pattern. The Pt particles with average size of 3.5nm were deposited during microwave irradiation. Further, co-doping was confirmed using X-ray photoelectron spectroscopy (XPS). The synthesized Pt/NP-rGO was analyzed in situ as an oxygen reduction reaction electrocatalyst in acidic medium. Our results indicate that Pt/NP-rGO follows a four e? ORR process attributed to increased adhesion between the Pt and N, P co-doped graphene oxide due to e? transfer from graphene to N and P atoms, thus indicating its potential in energy-related applications as an effective ORR electrocatalyst. The Author(s), under exclusive licence to The Materials Research Society 2024. -
Online cooperative learning: exploring perspectives of pre-service teachers after the pandemic
Mainly, research has explored pre-service teachers perspectives toward cooperative learning within face-to-face teaching. However, in a post-pandemic scenario, previous research has yet to effectively explore pre-service teachers (PSTs) perspectives toward online cooperative learning (OCL) in teacher education programs. So, recognizing the gap in the literature, this paper aims to explore the perspectives of PSTs towards OCL. The researchers employed a qualitative research design for the present study. The researchers conducted semi-structured interviews with 10 PSTs who underwent OCL during the pandemic. These PSTs may possess digital proficiency, virtual collaboration abilities, flexibility in evolving educational environments, and an enhanced understanding of online cooperative learning methodologies within modern education. Researchers employed a thematic analysis to analyze the qualitative data obtained. The various themes that emerged from the study are perceived benefits of OCL, challenges to OCL, technological proficiency, learning strategies and support, and building a supportive online learning community. Future researchers may contribute to advancing effective online learning practices by gaining a deeper understanding of pre-service teachers perspectives towards OCL through research on a larger scale, including various teacher education programs in various countries. 2024, Institute of Advanced Engineering and Science. All rights reserved. -
Online Education and English Language Learning Among Tribal Students of Kerala
Kerala, a South Indian state has tribal population in all her districts. About 1.5% of the total population of the state constitute tribal population. They depend upon natural environment and resources for their survival. Children from the same community usually depend on government funded schools for their education. Education for this deprived section during COVID 19 Pandemic was a massive exclusion and an uphill task. Digital divide and medium of communication (Standard Malayalam) were some of the critical concerns to knowledge acquisition among tribal children. This paper primarily focuses on the challenges of online education among tribal students with a clear emphasis on the English language acquisition. This study was conducted in four most tribal populated districts of the State, namely, Wayanad, Malappuram, Palakkad, and Idukki. This is a qualitative explorative study that explores the experiences of the tribal students' English language learning challenges from the teachers' perspective in these districts. The Electrochemical Society -
Online fake review identification based on decision rules
Posting of online reviews play a dominant role in sharing the customers opinion in social Medias. But the challenge is how to trust these reviews. Many researchers carried their work on sentimental analysis, predictions or forecasting but very few focused on fake reviews analysis. Fake reviews also change the mood of the people on their buying pattern. In the online shopping at a greater extent. In this paper, several conditions are applied on the reviews to identify fake reviews using support vector machines. Experimental results are validated using various accuracy measures and compared to state of the art methods to demonstrate the efficacy of the proposed method. 2019, World Academy of Research in Science and Engineering. All rights reserved. -
Online Health Information Behavior: A study based on PLS-SEM
In this digital era, internet provides a speedy, economical and convenient platform for seeking information on health. Moreover, the presence of audio visual resources for health and option to get expert opinion directly makes online health information seeking behaviour more adaptable among the health consumers. The major purpose of this study is to investigate the relationship between online health information seeking behaviour and the consequences of post-search. For doing the analysis, Smart PLS2 is used to execute structural equation modelling technique to understand the relationship between variables under study. The results of the study recommend that one's intention to search health information online is a significant predictor of post-search behavior in terms of altering health condition, visiting physician or sharing the same information with others. The present study gives a strong indication to the health care practitioners to understand the mechanism of desires and intentions of a healthcare consumer towards online health information seeking behavior. 2021 IEEE. -
Online Voting System Using Blockchain
One of the major areas in technical development is blockchain and bitcoin. These technologies have enabled many simulations in in-hostile applications that have major issues with security and integrity of data. To provide more relevance to the available cyberphysical systems in the dimension of security, the blockchain technology offers a major help. If the present scenario is considered, we have multiple day-to-day applications that have been simulated and require more security enhancement. For example, the E-voting systems are a trend and their security features have to be upgraded to authenticate both systems and processes. The present research paper focuses on the same application and aims to provide security upgradation by proposing a working model of e-voting systems. 2020, Springer Nature Singapore Pte Ltd. -
Open global shadow graph and its zero forcing number
Zero forcing number of a graph is the minimum cardinality of the zero forcing set. A zero forcing set is a set of black vertices of minimum cardinality that can colour the entire graph black using the colour change rule: each vertex of G is coloured either white or black, and vertex v is a black vertex and can force a white neighbour only if it has one white neighbour. In this paper we identify a class of graph where the zero forcing number is equal to the minimum rank of the graph and call it as a new class of graph that is open global shadow graph. Some of the basic properties of open global shadow graph are studied. The zero forcing number of open global shadow graph of a graph with upper and lower bound is obtained. Hence giving the upper and lower bound for the minimum rank of the graph. 2023, Proyecciones. All Rights Reserved.