Search

Non-Newtonian viscoelastic fluid flow past an isothermal sphere embedded in non- Darcy porous medium is examined numerically in this work. To be specific, the non-Newtonian Powell-Eyring fluid in the presence of both the heat and mass characteristics is mathematically modelled in terms of differential system. A non-Darcy drag force model is employed to simulate the effects of linear porous media drag and second-order Forchheimer drag. The surface of the sphere is maintained at a constant temperature and concentration. The numerical solution of the resultant system is reported via the Keller box method. Both tabular and graphical forms are adopted to identify the variations in Powell- Eyring fluid velocity, Powell-Eyring fluid temperature, and Powell-Eyring fluid concentration. In addition, the surface physical quantities, namely, skin friction and heat and mass transfer rates, are explored. The obtained observations are validated with earlier Newtonian studies. We found an excellent match in this regard. It is found that the velocity is reduced with increasing fluid parameter ([epsilon]), Forchheimer parameter ([LAMBDA]), and tangential coordinate ([xi]). In contrast, the temperature and concentration are increasing with increasing value of [epsilon]. A very slight increase in velocity is seen with an increase in the local non-Newtonian parameter, [delta]. But the temperature and concentration decrease slightly with an increase in [delta]. An increase in Darcy parameter enhances velocity but reduces both temperature and concentration. The present study finds an extensive array of applications in modern nuclear engineering, mineral and chemical process engineering, nuclear waste in geomaterial repositories, petroleum product filtration, and insulation systems. Key words: non-Newtonian Powell-Eyring fluid, isothermal sphere, non-Darcy flow, porous media, nuclear materials storage. Nous recherchons ici un resultat numerique pour le flot d'un fluide viscoelastique non newtonien passant une sphere isotherme implantee dans un milieu de Darcy poreux. Pour etre plus precis, nous presentons une etude mathematique differentielle d'un fluide de Powell-Eyring en presence de transfert de masse et de chaleur. Nous utilisons un modele de trainee non Darcy pour simuler les effets de trainee du milieu poreux lineaire et la trainee du second ordre de Forchheimer. La surface de la sphere est maintenue a temperature et concentration constantes. La solution numerique du systeme ainsi defini est presentee par la methode de la boite de Keller. Nous adoptons tables et graphiques pour identifier les variations de vitesse du fluide de Powell-Eyring, de la temperature du fluide de Powell-Eyring et de la concentration du fluide de Powell-Eyring. Nous explorons aussi les quantites physiques superficielles, nommement le frottement pelliculaire et les taux de transfert de chaleur et de masse. Nos resultats sont valides par comparaison avec des calculs newtoniens anterieurs. Nous y trouvons un excellent accord. Nous trouvons que la vitesse est reduite par l'augmentation du parametre du fluide ([epsilon]), du parametre de Forchheimer ([LAMBDA]) et de la coordonnee tangentielle ([xi]), alors que la temperature et la concentration augmentent avec ([epsilon]). On voit qu'une legere augmentation de la vitesse est observee avec l'augmentation du parametre non newtonien local [delta], qui cause une legere diminution de la temperature et de la concentration. Cette etude trouve beaucoup d'applications en ingenierie nucleaire moderne, en ingenierie minerale et chimique, en entreposage de residus nucleaires dans des geomateriaux, en filtration de produits petroliers et en systemes d'isolation. [Traduit par la Redaction] Mots-cles : fluide de Powell-Eyring non newtonien, sphere isotherme, flot non Darcy, milieu poreux, entreposage de materiel nucleaire., 1. Introduction The interest of scientists and researchers towards non-Newtonian fluid flow characteristics continues to grow in response to significant applications in various areas of advanced industrial technologies, which include [...]

This article aims to study theoretically the combined magneto hydrodynamic flows of casson viscoplastic nanofluid from a horizontal isothermal circular cylinder in non-Darcy porous medium. The impacts of Brownian motion and thermophoresis are consolidated and studied. The governing partial differential equations are converted into nonlinear ordinary differential equations using suitable non-similarity transformation and are solved numerically using Keller-Box finite difference technique. The numerical method is validated with previous published work and the results are found to be in excellent agreement. Numerical results for velocity, temperature, concentration along with skin friction coefficient, heat and mass transfer rate are discussed for various values of physical parameters. It is observed that velocity, heat and mass transfer rate are increased with increasing casson fluid parameter whereas temperature, concentration and skin friction are decreased. Velocity is reduced with increasing Forchheimer parameter whereas temperature and nano-particle concentration are both enhanced. An increase in magnetic parameter is seen to increase temperature and concentration whereas velocity, skin friction heat and mass transfer rate are decreased. The present model finds applications in electric-conductive nano-materials of potential use in aviation and different enterprises, energy systems and thermal enhancement of industrial flow processes.

Libraries play a crucial role in promoting sustainable development goals (SDGs) and environmental education worldwide. As a society becomes increasingly aware of the urgent need for environmental conservation and sustainable practices, libraries have embraced the concept of becoming "green libraries" to fulfil their role as information hubs and catalysts for positive change. This study aims to explore the global perspective on the role of green libraries in advancing SDGs and environmental education. The study utilises a comprehensive literature review to examine the multifaceted dimensions of green libraries and their contributions to sustainable development and environmental education. It analyses various case studies, initiatives and best practices from libraries around the world, highlighting the diverse approaches adopted by these institutions to promote environmental awareness, provide access to green information and facilitate community engagement. Findings from the study reveal that green libraries serve as essential platforms for disseminating environmental knowledge, fostering sustainability literacy, and empowering individuals to make informed decisions regarding environmental issues. These libraries not only curate collections of environmentally-focused materials but also employ sustainable practices in their operations, such as energy-efficient buildings, recycling programs and digital resource optimisation. Furthermore, green libraries actively collaborate with local communities, educational institutions and government bodies to promote environmental awareness through workshops, seminars and outreach programs. This study also identifies challenges faced by green libraries, including limited financial resources, technological barriers, and the need for continuous staff training. To overcome these challenges, it emphasises the importance of establishing partnerships with stakeholders, leveraging digital technologies for information dissemination and integrating sustainability principles into library policies and strategic planning. The study highlights the critical role of green libraries as transformative agents for achieving SDGs and fostering environmental education on a global scale. It provides valuable insights and recommendations for library professionals, policymakers, and researchers to enhance the effectiveness and impact of green libraries in promoting a sustainable future. [ABSTRACT FROM AUTHOR]