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Study of hybrid nanofluid flow in a stationary cone-disk system with temperature-dependent fluid properties
Cone-disk systems find frequent use such as conical diffusers, medical devices, various rheometric, and viscosimetry applications. In this study, we investigate the three-dimensional flow of a water-based Ag-MgO hybrid nanofluid in a static cone-disk system while considering temperature-dependent fluid properties. How the variable fluid properties affect the dynamics and heat transfer features is studied by Reynoldss linearized model for variable viscosity and Chiams model for variable thermal conductivity. The single-phase nanofluid model is utilized to describe convective heat transfer in hybrid nanofluids, incorporating the experimental data. This model is developed as a coupled system of convective-diffusion equations, encompassing the conservation of momentum and the conservation of thermal energy, in conjunction with an incompressibility condition. A self-similar model is developed by the Lie-group scaling transformations, and the subsequent self-similar equations are then solved numerically. The influence of variable fluid parameters on both swirling and non-swirling flow cases is analyzed. Additionally, the Nusselt number for the disk surface is calculated. It is found that an increase in the temperature-dependent viscosity parameter enhances heat transfer characteristics in the static cone-disk system, while the thermal conductivity parameter has the opposite effect. The Author(s) 2024. -
Study of nanofluid flow in a stationary cone-disk system with temperature-dependent viscosity and thermal conductivity
The substantial temperature gradient experienced by systems operating at relatively high temperatures significantly impacts the transport characteristics of fluids. Hence, considering temperature-dependent fluid properties is critical for obtaining realistic prediction of fluid behavior and optimizing system performance. The current study focuses on the flow of nanofluids in a stationary cone-disk system (SCDS), taking into account temperature-dependent thermal conductivity and viscosity. The influence of Brownian motion, thermophoresis, and Rosseland radiative flux on the heat transport features are also examined. The Reynolds model for viscosity and Chiam's model for thermal conductivity are employed. The Navier-Stokes equation, the energy equation, the incompressibility condition, and the continuity equation for nanoparticles constitute the governing system. The Lie-group transformations lead the self-similar ordinary differential equations, which are then solved numerically. Multi-variate non-linear regression models for the rate of heat and mass transfers on the disk surface were developed. Our study reveals a notable decrease in the rate of heat and mass transfer when pre-swirl exists in the flow. The significant influence of nanofluid slip mechanisms on the effective temperature and nanofluid volume fraction (NVF) within the system is highlighted. Furthermore, the variable viscosity property enhances the temperature and NVF of the SCDS. 2024 Author(s). -
Detection of strangers based on dogs sound
Nowadays, people having a pet at home are increasing. Usually, dog is the favorite pet animal for most of the people in the world. Dogs are more capable of identifying strangers in the surroundings than humans. The proposed work identifies the strangers based on the barking sound of the dog. In this anticipated work, multiple features are extracted from the dogs barking sound using Fast Fourier Transform and Statistical based methods. The classification is done using Nae Bayes classifier. The dataset contains 770 barking audio files of 8 dogs. Whenever known and unknown person comes home, the sounds of the dogs are recorded. The classification result for identifying the stranger is 79.1094%. BEIESP. -
Photoisomerization Dynamics of 2-[(E)-(4-fluorophenyl)diazenyl]-1 H -imidazole: A Theoretical and Experimental Insight
This study investigates the photoresponsive behavior of substituted azobenzenes with a specific focus on their nonlinear optical response. This study suggests that azoimidazole substitution is a better alternative to azobenzene derivatives for nonlinear optical responses. The synthesis, characterization, photophysical property and isomerization pathway of 2-[(E)-(4-fluorophenyl)diazenyl]-1H-imidazole (E-2g) are presented as an optical limiter through a comprehensive blend of experimental and theoretical approaches. Notably, E-2g exhibited a lower energy barrier than reported azobenzenes. The trans-to-cis photostationary state was reached in 75 min, while the cis-to-trans state was achieved in 60 min at 354 nm. The study further explores the photoisomerization pathway of E-2g, highlighting its nonlinear absorption, which has a nonlinear absorption coefficient (?eff) of 8.8 10-11 m/W at 20 ?J, as determined by Z-scan measurements. The results suggest that E-2g exhibits significant nonlinear absorption characteristics, which helps in applications requiring protection from intense light sources. 2024 World Scientific Publishing Company. -
Diazo-pyrazole analogues as photosensitizers in dye sensitised solar cells: Tuning for a better photovoltaic efficiency using a new modelling strategy using experimental and computational data
The designing of a dye sensitised solar cell (DSSC) is one of the frontiers in harvesting solar energy as it provides an alternative to economic photovoltaic devices with increased efficiency. In this manuscript, we report a new methodology using experimental and theoretical data for the evaluation of the photosensitiser activity of organic dyes using theoretical simulations and experimental cell efficiency data. As a representative example, we designed a series of 54 novel pyrazole derivatives which are subjected to TD-DFT simulations (CAM-B3LYP/6-311G++ (2d, p)) and photovoltaic modelling. Data from computational simulations, as well as known experimental cells, are used for the calculation of photovoltaic efficiency. We selected pyrazole derivatives because of its proven use in DSSC as an effective dopant in a blended polymer electrolyte in nanocrystalline DSSC. Fine-tuning with the effect of substitution and with the ?spacers at the ortho, meta and para positions for -OCH3, -OH, -CHO, -NO2 respectively were done. Enhanced efficiency of 7.439% was observed as compared to the standard cell of efficiency of 5.530%. An increase in efficiency was not observed with the effect of ?spacers. The newly designed dyes demonstrate desirable energetic and spectroscopic parameter that can lead to efficient metal-free organic dye sensitiser for DSSC's. The main advantage of this strategy is the incorporation of both simulated and experimental data. It will reduce the possible errors from the simulations and also, helps in performing time-consuming experimental studies. 2020 Walter de Gruyter GmbH, Berlin/Boston. -
Unveiling the therapeutic potential of azopyridine derivatives for trypsin inhibition: a DFT and In-Vitro approach
Heterocyclic azo derivatives have emerged as promising scaffolds for drug development. This study focused on the synthesis, computational analysis, and biological evaluation of a series of azopyridine derivatives (1a, 1d, 1 g, 1 h, 1 m, 1p, and 1s) as potential trypsin inhibitors. Density Functional Theory calculations indicated that derivative 1 h exhibited the lowest HOMO-LUMO energy gap 3.167 eV and was characterised as a soft molecule, suggesting strong binding capabilities. Molecular docking studies confirmed that 1 h binds favourably to the active site of trypsin with a glide score of ?6.581 kcal/mol and binding energy of ?29.95 kcal/mol. Along with docking studies, the stability of the trypsin-1 h complex was further analyzed using molecular dynamic simulations at 200 ns. The results showed that the ligand molecule 1 h bound strongly at the active site of trypsin. In-vitro enzyme assays determined the IC50 value of the molecule as 100 M, demonstrating enhanced potency. These results indicate that AzPy derivatives, particularly 1 h, hold considerable promise as therapeutic agents for inflammatory disorders and cancer, paving the way for further exploration in drug development and targeted therapies. Further research is warranted to explore 1hs efficacy, safety, and structure-activity relationships. Highlights: DFT studies were used to classify molecules based on their softness and hardness. Molecular docking, simulation, and in-vitro studies have identified potential anti-trypsin activity of candidate molecules. Experimental and computational calculations were in close agreement. 2024 Informa UK Limited, trading as Taylor & Francis Group. -
Spectroscopic and TDDFT investigation of highly selective fluoride sensors by substituted acyl hydrazones
In this work, we report the synthesis of two receptors for fluoride ions based on acyl hydrazone, such as N?-[(1Z)-1-(4-fluorophenyl)ethylidene]benzohydrazide (R1) and N?-[(1Z)-1-(2-hydroxyphenyl)ethylidene]benzohydrazide (R2). The receptors R1 and R2 were synthesized from the corresponding ketones and benzoic acid hydrazide and characterized spectroscopically by UVvisible, IR and 1HNMR techniques. The response of R1 and R2 towards different anions was studied colourimetrically in acetonitrile. The receptors exhibited a specific response towards fluoride ions. Further studies of 1:1 composition of receptors, R1/R2:fluoride ions by different spectroscopic techniques such as UVVisible, IR and 1HNMR spectroscopy indicated the participation of -NH proton of the receptors in the sensing action through the hydrogen bonding. To understand the mechanism, Time-Dependent Density Functional Theory (TD-DFT) studies were done using the CAM-B3LYP/6311G++ (3df,2p) with Grimme's D3BJ empirical dispersion basis set. The studies supported the role of hydrogen bonding interaction of -NH and-OH protons of the receptors with the fluoride ions. 2020 Elsevier B.V. -
Experimental and Theoretical Investigation of 3-[(2-chlorophenyl)diazenyl]pyridine-2,6-diamine as Optical Limiter
Azobenzenes undergo reversible trans-cis photoisomerization and have been extensively studied as photoresponsive material. In contrast, azopyridines have garnered relatively less attention despite their similar photochemistry. When compared to azobenzene, azopyridines offer more opportunities for material design through hydrogen bonding and coordination chemistry. Here, we report the isomerization for 3-[(2-chlorophenyl)diazenyl]pyridine-2,6-diamine (1od) through an integrative experimental and computational study. Notably, the energy barrier of 1od was significantly lower than that of previously reported azobenzenes. Moreover, we investigated and elucidated the photoisomerization pathway. 1od exhibited high nonlinear absorption, with a nonlinear absorption coefficient (?eff) of 1.31 (Formula presented.) 10?9 m W?1, as determined by Z-scan measurements. The results indicate that 1od has potential applications in optical limiters, which are used to fabricate protective eyewear and safeguard optical sensors from damage. 2023 Wiley-VCH GmbH. -
Fluorescent Photosensitizers: A Promising Tool for Biomedicine
The growing demand for the detection for biomedical imaging has taken the interest of researchers as there is a significant increase in cancer and malignant diseases across the globe. Photosensitizers assisted with fluorescent properties can be a pioneer in this field. Photosensitizers generally damage the living cell, however, selected fluorescent photosensitizers can offer a minimal threat to the living cells. Medically relevant processes such as live cell imaging and photodynamic therapy can be monitored using this technique. Some of the commonly used fluorescent photosensitizers include porphyrins, chlorins, and bacteriochlorins. This chapter addresses the significance, limitations, and future perspectives of fluorescent photosensitizers in biological applications. Scientists can develop efficient fluorescent photosensitizers for easy detection and cure of different infectious diseases. The chapter also puts forward a deeper understanding of the principle underlying tunable fluorescent properties, and the recent efforts for developing efficient fluorescent photosensitizers. 2022 Nova Science Publishers, Inc. -
Anti-bacterial and biocompatibility properties of green synthesized silver nanoparticles using Parkia biglandulosa (Fabales:Fabaceae) leaf extract
The biosynthesis of silver nanoparticles is considered to be a feasible, green, and eco-friendly method. Silver nanoparticles (AgNPs) were synthesized using badminton ball tree (Parkia biglandulosa) leaf extract and their significant physiochemical properties were characterized. The aqueous extract of the leaf of P. biglandulosa act as a reducing as well as capping agent for the reduction of Ag+ ?ions. FTIR analysis was conducted to find out the compounds that were liable for the bio-reduction of silver ions and to study the functional groups present in P. bigalandulosa leaf extract. The biologically reduced silver nanoparticles showed a surface plasmon resonance at 439 ?nm as studied from the UVvisible absorption spectrum. TEM studies confirmed the shape of the nanoparticles to be spherical with an average diameter of 15 ?nm. The anti-bacterial properties of the prepared nanoparticles were tested against Bacillus cereus by well plate method. Biosynthesized silver nanoparticles (PbAgNPs) at 0.02 ?M concentration showed the most antibacterial activity with a zone of inhibition of 7 ?mm. The high biocompatibility of the PbAgNPs by using human skin fibroblast cell line was evaluated by Alamar Blue reduction assay. The PbAgNPs had shown the highest cell viability when compared to native nanoparticles, meanwhile, a significant increase in cell viability was noted for the nanoparticles. The biosynthetic approach for synthesis was found to be a facile, rapid, single-step, safe, and effective alternative to the conventional physical/chemical methods. 2021 The Authors -
Antecedents of online impulsive buying behaviour: A meta-analysis
The advancement of technology has created curiosity among researchers and marketers in identify the possible antecedents to online impulsive buying. The concept of impulse buying is often defined as ?unplanned? purchase behaviour. Researchers have identified few factors based on a systematic review of literature. The factors have then been combined using Meta-Analysis to arrive at variables that act as antecedents to Impulse Buying behaviour. The variables identified include promotion, web atmospherics, online behaviour, shopping context, buyers emotions and buyers personality which all contribute significantly proving to be an important antecedent of impulsive online buying. The above identification of antecedents will help the marketing practitioners to understand and improve the characteristics of each antecedent. Further investigation can be done by further research scholars on finding if any variable could be added in enhancing the sales by creating a better impulse on the online platform. IJSTR 2019. -
Role of E-Shopping Orientation and Trust in predicting Impulsive Buying Behaviour. A Study Based on members of Generation Y in India; [El papel de la orientaci y la confianza en las compras electricas en la predicci del comportamiento de compra impulsiva. Un estudio basado en miembros de la Generaci Y en la India]
Impulse Buying and the drivers of similar consumer behaviours have captured the interest of researchers for quite some time now. The construct was first explored in the context of offline or brick and mortar stores. However, with the growing popularity of online retail stores has led to the concept being included in studies on customer behaviour, specifically in the online context. In the current study, the researchers attempt to contribute to literature on customer behaviour in the online environment by exploring the relationship between E-Shopping Orientation, Trust and Impulsive Buying Behaviour. The focus of the currents study is the members of Generation Y. The scope was limited to this specific section, given that each generation differs from the other in terms of their behaviour, needs and drivers. While the direct impact of E-shopping Orientation on Impulsive Buying Behaviour was found to be not statistically significant, the indirect effect was found to be significant. This suggests that Trust fully mediates the relationship between E-Shopping Orientation and Impulsive Buying Behaviour. In addition to contributing to literature in the area of customer behaviour, the findings also add to our understanding of a major section of the Indian customer base. (2024), (Universidad Pablo de Olavide). All Rights Reserved. -
E-shopping orientation, trust and impulse buying in the online context a study based on female members of Generation Z in India
A large number of studies have attempted to understand consumer behaviour in the online context. One construct that has been of particular interest to marketers, retailers and researchers, is impulse buying behaviour. The number of studies attempting to understand the drivers of impulsive purchases has been on a rise. The current pandemic also saw a rise in impulsive purchases and the interest in the construct was renewed. The current study is based on the S-O-R model and evaluates the relationship between e-shopping orientation, trust and impulse buying behaviour. The findings are based on data collected from female members of Generation Z and suggest that frequent visits to e-retail stores and increased patronage can increase the level of trust in the retail partner and influence the number of impulsive purchases. The findings are particularly significant for retailers looking to drive sales through impulsive purchases. In addition, the findings provide empirical support for the application of the S-O-R model to online retail context. Copyright 2024 Inderscience Enterprises Ltd. -
Electrochemical sensors using conducting polymer/noble metal nanoparticle nanocomposites for the detection of various analytes: a review
Abstract: Conducting polymer/noble metal nanoparticle (CP/NMNP) composites have made a history of sorts since its inception in the field of electrochemical research, which resulted to be an impetus for scientists to indulge and explore the opportunities it can unleash. This review throws light on the synergic effects and the enhancement in the electrocatalytic activity on dispersing noble metal particles on conducting polymers. This review aids the readers to analyse the electrochemical sensing efficiency of CP/NMNP composites, and provides a platform for the researchers to engineer and develop CP/NMNP composite materials for electrochemical sensing. This work also draws the attention of the readers to the application of NMNP (Ag, Au, Pt, Pd, Ir, and Ru) dispersed on CPs [polyaniline (PANI), polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT)] and their composites with other materials like carbon nanotubes (CNTs), graphene, zeolites, and peptide nanotubes (PNTs) for sensing of various analytes. Graphic abstract: This review draws the attention of the readers to the application of NMNP (Ag, Au, Pt, Pd, Ir and Ru) dispersed on CPs (polyaniline (PANI), polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT)) and their composites with other materials like carbon nanotubes (CNTs), graphene, zeolites, and peptide nanotubes (PNTs) for sensing of various analytes.[Figure not available: see fulltext.]. 2021, Islamic Azad University. -
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Factors Influencing Consumer Purchase Decision in Mid-Size Car Segment.
Volume 2, Issue 4, August, ISSN: 2277-6621 -
Can leaders transform humiliation into a creative force? /
Journal Of Leadership Studies, Vol.9, Issue 3, ISSN No: 1935-262X. -
Can Leaders Transform Humiliation Into a Creative Force?
The intractable group conflicts, mass killings, and genocides around the world attest to the role of humiliation as a negative force causing violence and destruction. Based on the analysis of the speeches of Dr. B.R. Ambedkar, the most important leader of Dalits (ex-untouchables) in India, it is suggested that leaders possess the capacity for creative use of humiliation. The creative use of humiliation is made possible by the innovation in constructing social identities involved in humiliation. Creative leadership can be an important catalyst that can transform humiliation into a positive force for social change. 2015 University of Phoenix. -
Zinc gallate nanoparticles: A multifunctional material for optoelectronic and optical limiting applications
Wide-bandgap spinel oxides have attracted increasing attention due to their structural stability and multifunctional properties, yet the nonlinear optical and optical limiting behaviour of zinc gallate (ZnGa?O?) remains largely unexplored. To address this gap, ZnGa?O? nanoparticles were synthesised using a hydrothermal method at different pH levels, with X-ray diffraction (XRD) confirming a phase-pure cubic spinel structure at pH = 10. Rietveld refinement further validated the crystal structure and was visualised using VESTA software. FTIR confirmed the presence of characteristic metaloxygen bonds. FESEM revealed an agglomerated nanoparticle morphology. TEM verified the particle structure, and EDAX confirmed elemental composition, collectively supporting the cubic structure. XPS validated the oxidation states of Zn? and Ga ?. Optical characterisation using photoluminescence and diffuse reflectance spectroscopy confirmed the wide bandgap nature of the material. Strong blue emission under UV excitation demonstrated the photoluminescent behaviour. DC conductivity measurements were conducted to evaluate the electrical transport behaviour of the synthesised material. The third-order nonlinear optical (NLO) properties were systematically investigated using open- and closed-aperture Z-scan techniques under continuous-wave and nanosecond pulsed laser excitation. The material exhibited reverse saturable absorption, a negative nonlinear refractive index, and a large third-order susceptibility, along with efficient optical limiting behaviour under pulsed excitation. These results demonstrate that hydrothermally synthesised ZnGa?O? nanoparticles possess strong third-order nonlinearity and effective optical limiting performance, establishing zinc gallate as a promising spinel oxide for laser protection and advanced photonic applications. 2026 Elsevier B.V. -
XENOPHOBIC ATTITUDES AND REPRESENTATIONS IN SOCIAL MEDIA DURING COVID-19 PANDEMIC IN INDIA; [ACTITUDES Y REPRESENTACIONES XENOFICAS EN LAS REDES SOCIALES DURANTE LA PANDEMIA DE COVID-19 EN LA INDIA]
Social media activity was reported to have significantly increased during the pandemic period as most of the daily routines transformed into the digital space. This paper attempted to explore the politics of representation in digital space using Foucauldian theories of power and discipline. A qualitative exploration of the xenophobic attitudes and representation was conducted on 123 young adults to understand how health concerns associated with the pandemic influenced social representations and marginalization of certain social sections and how participants recognized and understood their contribution to this group polarization. Thematic analysis of participant opinions indicated a significant change in polarization and attitude towards out-groups following the pandemic outbreak. The existing hierarchical homogenization and polarization of the marginalized moderated by polarized political affinities were found to be translated into digital space intensifying xenophobic attitudes thereby contributing to the evolution of new digital cultures and hierarchies in digital literacy. 2022 UNIVERSIDADE FEEVALE All rights reserved.