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Brinkman-Bard convection in a box with temperature modulation
A bounded porous box saturated with Newtonian fluid and subjected to a sinusoidal temperature gradient has various practical applications, such as solar energy storage, groundwater remediation, food processing, and chemical reactors. We address the generalization of the classical Rayleigh-Bard convection problem in a horizontal fluid layer in an infinitely large domain heated from below to a finite three-dimensional box. We also look into a more intricate form of the modulated Rayleigh-Bard problem in which the temperature at the bottom boundary varies sinusoidally. The Rayleigh number quantifies the non-sinusoidal part of the temperature gradient, while the amplitude and frequency of modulation describe the sinusoidal one. The critical Rayleigh number is determined using linear and nonlinear stability analyses; for the latter, the energy method is used. There is a possibility of subcritical instabilities, as evidenced by the energy stability estimates being lower than the linear ones. Furthermore, eigenvalues are obtained as a function of aspect ratios, modulation amplitude, and frequency for varying Darcy numbers. Modulation amplitude more significantly triggers a change in flow patterns at the onset of convection compared to the effect of other parameters. Considering water-saturated porous media made up of different materials, we report the critical temperature difference between lower and upper surfaces required for the onset of convection. In addition, a comparison between such a temperature difference obtained from linear theory and the energy method is also provided in the same manner. It is observed that subharmonic instability occurs for all considered porous media packed densely or sparsely. 2024 Author(s). -
Channel Selection Using Stochastic Diffusion Search Algorithm for Classification in Brain-Computer Interface
Utilization of the Brain-Computer Interfaces (BCI) is done via Electroencephalogram (EEG) signals that provide several environmental interactions among individuals having restricted movements owing to neurodegenerative diseases or strokes. However, the BCI system was based on Motor Imagery (MI). It was not used for any form of real-life application owing to a decrease in the performance of various Common Spatial Pattern (CSP) algorithms, especially while the actual number of channels was high. A multi-channel structure of such EEG signals can increase cost and bring down speed. Due to this, a reduction in the system cost by the detection of active electrodes during the process can increase accessibility. This way, optimization techniques in choosing electrodes can be used to determine other effective channels by employing a method of random selection. For this work, a Stochastic Diffusion Search (SDS) algorithm based on herd optimization techniques was used with four different classifiers, which were the AdaBoost, the Classification and Regression Tree (CART), the Naive Bayes (NB) as well as the K-Nearest Neighbor (KNN). The channels that were chosen frequently were determined to improve the system performance with regard to accuracy and speed. The results proved that the approach proposed was successful in bringing down the channel number and run time without affecting the accuracy of classification. 2024 Seventh Sense Research Group. -
Teacher Trainee's Acceptance of Interactive eBooks for Teaching: An Analysis Using the Modified Technology Acceptance Model (TAM)
The current empirical study utilized the Technology Acceptance Model (TAM) to investigate teacher trainees' acceptance of interactive eBooks for teaching. The study investigated the relationships among variables such as attitude toward using interactive eBooks, perceived ease of use, perceived usefulness, enjoyment, perceived self-efficacy, and behavioural intention to use. A sample consisting of 89 teacher trainees studying in diploma and bachelors teacher training programs from two private and public universities in Malaysia participated in the study. The TAM model, which involves seven hypotheses, was tested using the Partial Least Square Structural Equation Modelling approach (PLS-SEM). The key findings of this empirical study confirmed that attitude influences both behaviour intention to use, and perceived self-efficacy of teacher trainees in teaching using interactive eBooks. Besides, the study confirmed a direct effect of ease of use on the level of enjoyment and a direct effect of perceived usefulness on the perception of ease of use. The study findings shed light on preparing teacher trainees for technology-integrated teaching. 2024, The Pacific Association for Computer Assisted Language Learning (PacCALL). All rights reserved. -
Folic Acid-Modified B-Type Y2O3:Eu3+ Quantum Dots: A Bright Approach to Fluorescence Imaging of Cancer Cells
Clinical applications of nanophosphors have gained extensive interest in research areas such as bioimaging and targeted drug delivery. The development of nontoxic semiconductor quantum dots (QDs), which can replace the conventional fluorescent probes, can bring significant developments in the bioimaging industry. This work reports the synthesis of monoclinic Y2O3:Eu QDs, without and with surface functionalization using PEG/folic acid at low temperature and its application in live cancer cell imaging. The synthesized quantum dots show sharp absorption in the short UV region and an intense red emission at 614 nm. Concentration-dependent optical properties are studied in detail, and color purity is measured. Transmission electron microscopy substantiates the monoclinic structure, crystalline nature, and the lower particle dimensions essential for the biological applications. The surface-modified sample is characterized for its structural and luminescence properties. Biocompatibility was ensured by performing MTT Assay on L6 skeletal muscle cell lines (normal) and MCF 7 cell lines (cancer) for the samples without and with surface modification, respectively. Fluorescence detection experiments on SKMEL cells using an uncapped sample prove the suitability of the material as a fluorescent probe. The effect of surface functionalization on imaging results was established by carrying out fluorescence detection experiments on MCF 7 cells using PEG-folic acid-functionalized sample, which resulted in enhanced cell uptake, specific binding, and bright fluorescence emission. Thus, this work authenticates the suitability of the material to be used as a reliable nanophosphor and an efficient fluorescent probe for imaging cancer cells. 2024 American Chemical Society. -
Optimization Based Rice Leaf Disease Classification in Federated Learning
Numerous farmers worldwide are impacted by diseases connected to rice leaves that frequently endanger the sustainability of the rice industry. Diseases that affect the leaves of rice plants severely limit their ability to produce rice, and they are typically brought on by bacteria, viruses, or fungi. This paper proposes an innovative classification scheme for rice leaf diseases based on Federated Learning (FL). Here, FL framework comprises two entities, namely nodes and servers. Every node does initial local training using local data. Moreover, produced local model is then updated on server. Model aggregation is done at the server since several nodes update their local models and send them to it. The nodes download the global model that server has generated as a result. The nodes update their training using transferred global model and local model. The following series of actions are taken in the training model. The input image is mainly obtained from a database and pre-processed with a Kalman filter to eliminate noise. Then, numerous operations for data augmentation are applied. In addition, feature extraction is done and generated features are used in LeNet for rice leaf diseases classification. LeNet is trained using the Spotted Hyena Archimedes Optimizer (SHAO). The developed method shows better precision of 91.3%, recall of 92.2%, f-measure of 91.7%, loss function of 3.3%, Mean Square Error (MSE) of 7.3%, and Root MSE of 27.1%. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024. -
Impact of financial literacy on savings behavior: the moderation role of risk aversion and financial confidence
This research examines the impact of financial literacy on the savings behavior of investors residing in the Gulf Cooperation Council (GCC) region. It also investigates the moderating impact of financial confidence and risk aversion in the relationship between financial literacy and savings behavior. The primary data were collected from 357 respondents through a structured questionnaire using the snowball sampling method. The findings of this study suggest that financial literacy has a positive impact on investors' savings behavior. Further, the study also found that risk aversion significantly moderates the relationship between financial literacy and savings behavior. The three-way interaction between financial literacy, risk aversion, and financial confidence significantly affects the investors savings behavior. The study suggests that policymakers should emphasize training programs for investors on financial literacy, financial confidence, and risk aversion. The Author(s), under exclusive licence to Springer Nature Limited 2024. -
Instruments for measuring Digital Citizenship Competence in schools: a scoping review
The integration of digital technology into the teaching and learning process has both good and negative consequences. Several schools have incorporated digital citizenship to teach the responsible use of technology. The purpose of this scoping review is to provide an overview of research on tools for measuring digital citizenship competency among school children. This scoping study focuses on three main areas: (a) defining digital citizenship and competency; (b) instrument development and characteristics; and (c) key findings. The main outcomes of this research may help students, teachers, and school administrators implement digital citizenship education programs in schools. Italian e-Learning Association. -
A Conceptual Framework for Agile as HR Operational Strategy
Purpose: This paper examined Agile human resource (HR) as an operational strategy, emphasizing the relationships between operational, HR, and organizational strategies. It develops a collaborative culture, establishes learning organizations, supports agile team design, and improves agile strategic behavior. Agile HR has been underutilized in academic literature despite its potential, highlighting the disconnect between practitioner objectives and HR research. Methodology: A conceptual framework for Agile HR was developed using qualitative secondary research methods. Secondary sources included books, journal articles, research papers, reports, and whitepapers. A thematic analysis was used to code the data and identify themes relevant to Agile HR, and concept mapping was used to illustrate the relationships between the key concepts. Findings: A conceptual framework for Agile HR strategies was developed to foster an agile organizational culture and equip employees with agile strategic behaviors. Organizations will be able to establish and preserve a durable competitive edge in quickly changing marketplaces by using these tactics. Practical Implications: This paper provided insights into implementing agile HR operational strategies. Continuous iteration was used to enhance processes, boost employee experiences, and improve organizational agility to implement these strategies. Originality: While existing literature explored the relationship between organizational agility and dynamic capabilities, it largely overlooked the concept of agile behavior. This research addressed this gap by proposing a framework for flexible adjustments to human and organizational capabilities. It was a targeted approach for agile management aligned with organizational, HR, and agile strategies, emphasizing scalability. 2024, Associated Management Consultants Pvt. Ltd.. All rights reserved. -
Uniform Civil Code, Legal Pluralism and Inheritance Rights of Tribal Indian Women
The 42nd Amendment to the Indian Constitution heralded India as a Sovereign, Socialist, Secular Democratic Republic. It initiated a constitutional narrative that has sparked ongoing debates and scrutiny regarding the true essence of Indias secularism. With the National Democratic Alliance (NDA) led by Bhartiya Janta Party(BJP) forming government with after the 2024 general elections, the discussion on potential implementation of the Uniform Civil Code at the forefront of political discourse. In this commentary, the authors discuss legal pluralism in India and the impact of the introduction of a uniform civil code on on customary laws of tribes, placing special emphasis on the inheritance rights of tribal women. The paper also discusses the approach of the higher courts in securing property rights for tribal women in the absence of such a code. 2024, Spoldzielczy Instytut Naukowy. All rights reserved. -
Protection of intellectual property and human rights during health emergencies: an assessment of the patent waiver proposal
Purpose: Several countries, such as South Africa and India, believe that intellectual property rights (IPRs), including patents, impede the efficient increase in vaccine production to inoculate the global population as they scramble to recover from the COVID-19 pandemic. Their proposal at the World Trade Organization (WTO) to waive these pharmaceutical patents has been met with resistance from a few developed countries, who believe that the abrogation of IPRs is unnecessary, even during a pandemic. The purpose of this paper is to discuss the impact of a potential waiver of medical patents at the WTO versus the status quo of IPR laws in the global economy. Design/methodology/approach: This study examines key arguments from economic and moral standpoints regarding the provisions of the Trade-Related Aspects of Intellectual Property Rights (TRIPS) agreement and other related international agreements and their validity based on the premise of the internalisation of positive externalities posed by vaccines. Findings: The effectiveness of the TRIPS agreement in securing medical access is weak on account of the ability of profit-making multinationals to secure IP rights and on account of the Trans-Pacific Partnership, a multilateral agreement that supports patent evergreening and a period of protection on test data which challenges the access to medicines and the fundamental human right to health. Originality/value: This study examines international IPRs through the lens of human rights and proposes a new system that balances the two. 2022, Emerald Publishing Limited. -
Utilization of CO2 for Electrocarboxylation of Benzophenone Using MXene-Based Electrodes: A Sustainable Approach
The significant rise in atmospheric carbon dioxide (CO2) levels has prompted the need to develop efficient methods for CO2 conversion and fixation methods. Electrocarboxylation reaction is a highly efficient and sustainable method for activating and utilizing CO2, yielding essential carboxylic acids and their analogues, which are important intermediates in the pharmaceutical and fuel industries. This research demonstrates the efficiency of 2D Ti3C2Tx and Ta2CTx MXene-modified carbon fiber paper electrodes (Ti3C2Tx/CFP and Ta2CTx/CFP) for CO2 fixation with benzophenone in a tetrabutylammonium bromide/acetonitrile (TBABr/CH3CN) medium, yielding benzilic acid. Ti3C2Tx/CFP exhibited superior electrocatalytic activity with a lower reduction potential for benzophenone at ?1.0 V and achieved a 72% yield of benzilic acid at an optimum current density of 50 mA cm-2. In comparison, Ta2CTx/CFP exhibited a cathodic peak at ?1.08 V, producing a 66% yield at 70 mA cm-2. The electron paramagnetic resonance spectrum substantiates the generation of reactive radical intermediates during the reaction. Ti3C2Tx/CFP showed robust structural stability with ?88% Faradaic efficiency and a turnover frequency of 1.90444 10-5 s-1, indicating its potential for CO2 fixation. 2024 American Chemical Society. -
Leveraging digital yarn dyeing for colour consistency in apparel weaving
When compared to traditional processes, digital yarn dyeing provides substantial benefits in terms of color control, versatility, and environmental impact. However, technological obstacles and constraints exist. The promise of digital dyeing may be realized by carefully selecting technology, optimizing ink consumption, and adopting stringent quality control methods, resulting in improved colour constancy and a more sustainable textile sector. -
The role of energy efficiency in income inequality dynamics in developing Asia: Evidence from artificial neural networks
This study investigates the drivers of income inequality trends in seven developing Asian countries between 1990 and 2022, exploring the effects of energy efficiency, government spending, economic growth, globalization, and human development. The study investigates how these variables affect income inequality using various statistical methods, including long-run machine learning and prediction models. The findings indicate a negative impact of energy efficiency on income inequality, highlighting the potential of energy-saving measures in narrowing the income gaps between the rich and poor. Government spending, economic growth, globalization, and human development are also crucial in alleviating income inequality in developing Asian countries. This study underscores the importance of tailored policies, advocating for investments in energy efficiency, targeted government spending, larger economic integration, and inclusive growth strategies to address income inequality in developing Asia. 2024 -
Delving into the Exchange-Traded Funds (ETFs) Market: Understanding Market Efficiency
Exchange-traded funds (ETFs) are the most popular products in the financial sector today. There is extensive literature on the multifractal analysis of some stock markets, but not about the multifractal behaviour of the ETF market. This study examines the efficiency of stock index ETFs worldwide from an Efficient Market Hypothesis (EMH) perspective, using the ETFs: Ishares Msci World ETF (URTH), Ishares Russell 1000 ETF (IWB), SPDR S&P 500 ETF TRUST (SPY), Ishares Global Clean En. ETF (ICLN), Ishares USD Green Bond ETF (BGRN), from 1 January 2021 to 24 May 2024. It analyses a pre-conflict and a geopolitical conflict to uncover distinct patterns of behaviour reflecting significant changes in market conditions. Before the conflict, the Ishares MSCI World, Ishares Russell 1000, SPDR S&P 500 and Ishares USD Green Bond ETFs showed signs of anti-persistence in returns, indicating a lack of strong relationship or predictability between short-term price movements. The Ishares Global Clean Energy ETF did not reject the random walk hypothesis, suggesting that returns follow a pattern closer to random, where market prices already efficiently reflect all available information. During the conflict, there was a transition in the ETFs' behaviour patterns, as evidenced by the increases in slope values for Ishares MSCI World, Ishares Russell 1000, SPDR S&P 500, Ishares Global Clean Energy and Ishares USD Green Bond. Thus, the possible transition from anti-persistence to long-term memories in ETF returns during the conflict. For portfolio managers, these findings highlight the need to continually adapt investment strategies to manage risks better and take advantage of opportunities in a dynamic and complex investment environment. 2024, Creative Publishing House. All rights reserved. -
A study on deg-centric graphs
The deg-centric graph of a simple, connected graph G, denoted by Gd, is a graph constructed from G such that, V (Gd) = V (G) and E(Gd) = {vivj: dG(vi, vj) ? degG(vi)}. This paper introduces and discusses the concepts of deg-centric graphs and iterated deg-centrication of a graph. (2024), (Universidad Catolica del Norte). All rights reserved. -
Caste, Cricket, and Community Fraternal Intersections in Blue Star
[No abstract available] -
Exploring In Situ Kinetics of Oxygen Vacancy-Rich B/P-Incorporated Cobalt Oxide Nanowires for the Oxygen Evolution Reaction
Defect-engineering of transition-metal oxide-based nanocatalysts is an innovative approach for improving the oxygen evolution reaction (OER) owing to their enhanced activity and stability. The present study introduces a facile approach aimed at enhancing OER activity by incorporating boron and phosphorus into cobalt oxide nanowires (B/P-CoOx NWs). The resulting material, enriched with oxygen vacancies (Ov), as confirmed by X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR), induced a complete structural transformation from Co3O4 to a CoO phase. The B/P-CoOx NWs exhibited an impressive overpotential of only 230 mV to achieve a current density of 10 mA cm-2 in 1 M KOH. The presence of Ov was proved to be responsible for the improvement in conductivity along with the quantity and quality of active sites. Electrochemical kinetic analysis was performed to reveal the crucial role of Ov in facilitating the OER mechanism by enhancing the adsorption and desorption of OH- ions and O2 molecules from the surface. The robustness of the developed electrocatalyst was demonstrated through a chronoamperometric test conducted over 80 h and a recyclability test spanning 10 000 cycles. This study focuses on the fabrication and dynamic investigation of the electrocatalyst, laying the groundwork for further advancements in non-noble material-based electrocatalysts. 2024 American Chemical Society. -
Functional carbon nanoparticles modified poly(3,4-ethylenedioxythiophene) nanocomposites with enhanced dielectric and antibacterial properties
The importance of nanocomposites with tailored properties is growing due to their applications in various fields. In the present study, poly(3,4-ethylenedioxythiophene) (PEDOT) and functionalized carbon nanoparticles (f-CNPs) are synthesized by in-situ chemical oxidative polymerization and pyrolysis methods, respectively. The f-CNPs-PEDOT nanocomposites are prepared by varying the concentration of PEDOT (i.e., 1, 2.5, 5, 10, and 20 wt%), and the thermal stability, dielectric properties and antibacterial activities of f-CNPs-PEDOT nanocomposites were evaluated. The dielectric studies indicated that the addition of PEDOT has enhanced the dielectric properties due to interfacial polarization effect, whereas decreased the thermal stability due to degradation of PEDOT in the nanocomposite, however, it is higher than the pure PEDOT. The antimicrobial potential of synthesized f-CNPs-PEDOT nanocomposites was studied against two different bacterial strains, namely Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. The findings of this research have potential to open new opportunities for employing f-CNPs-PEDOT nanocomposites in physical sciences and antimicrobial applications. 2024 The Authors -
Studies on air jet erosion behavior of plasma-sprayed Cr2C3 coatings on Al6061 alloy
This study assesses the efficacy of plasma-sprayed Cr2C3 coatings on AA6061 aluminum alloy in reducing erosion at different angles (30, 60, and 90). The experimental setup involved maintaining a distance of 80 mm between the components, feeding the powder at a rate of 55 g/min, and applying a current density of 460 amps. Weight loss measurements and surface morphology analyses were performed using scanning electron and confocal microscopy. The findings suggest that the Cr2C3 coating significantly improves erosion resistance when compared to specimens without any coating. The erosion angle had a significant impact on the performance of the coating. The coating experienced the least weight loss at an angle of 30 (28.45 g), followed by increased losses at angles of 60 (30.34 g) and 90 (34.2 g). These findings emphasize the significance of the impact angle in determining the severity of material removal. 2024 The Authors -
Analysis of nonlinear convection and diffusion in viscoelastic fluid flow with variable thermal conductivity and thermal radiations
The study offers a thorough evaluation of the complex fluid dynamics and heat transfer phenomena in Williamson viscoelastic fluid flow, taking into account thermal radiations and variable thermal conductivity. The paper extends its analysis to include heat transfer effects, which are critical in several engineering and industrial applications, and digs into the complexity of non-Newtonian fluid behavior, with a special focus on thermal radiation, heat production, diffusion and viscous dissipation. The study makes use of mathematical models and numerical method RK4 to clarify the nonlinear interactions between convection and diffusion processes in this viscoelastic fluid. The energy and concentration equations are simulated in the presence of the modified Fourier and Fick laws. Moreover, the predicted heat flow is based on the Cattaneo-Christov theory. This research also sheds light on the interaction between rheological properties and thermal characteristics, providing important new knowledge to the broader field of fluid dynamics and heat transfer. 2024 World Scientific Publishing Company.