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Purpose: The performance of solid fins inside a differentially heated cubical cavity is numerically studied in this paper. The main purpose of the study is to make an optimization to reach the maximum heat transfer in the enclosure having the solid fins with studied parameters. Design/methodology/approach: The considered domain of interest is a differentially heated cube having heat-conducting solid fins placed on the heated wall while an opposite wall is a cooled one. Other walls are adiabatic. Governing equations describing natural convection in the fluid filled cube and heat conduction in solid fins have been written using non-dimensional variables such velocity and vorticity taking into account the Boussinesq approximation for the buoyancy force and ideal solid/fluid interfaces between solid fins and fluid. The formulated equations with appropriate initial and boundary conditions have been solved by the finite difference method of the second of accuracy. The developed in-house computational code has been validated using the mesh sensitivity analysis and numerical data of other authors. Analysis has been performed in a wide range of key parameters such as Rayleigh number (Ra = 104–106), non-dimensional fins length (l = 0.2–0.8), non-dimensional location of fins (d = 0.2–0.6) and number of fins (n = 1–3). Findings: From numerical methods point of view the used non-primitive variables allows to perform numerical simulation of convective heat transfer in three-dimensional (3D) regions with two advantages, namely, excluding difficulties that can be found using vector potential functions and reducing the computational time compared to primitive variables and SIMPLE-like algorithms. From a physical point of view, it has been shown that using solid fins can intensify the heat transfer performance compared to cavities without any fins. Fins located close to the bottom wall of the cavity have a better heat transfer rate than those placed close to the upper cavity surface. At high Rayleigh numbers, increasing the fins length beyond 0.6 leads to a reduction of the average Nusselt number, and one solid fin can be used to intensify the heat transfer. Originality/value: The present numerical study is based on hybrid approach for numerical analysis of convective heat transfer using velocity and vorticity that has some mentioned advantages. Obtained results allow intensifying the heat transfer using solid fins in 3D chambers with appropriate location and length. [ABSTRACT FROM AUTHOR]

Purpose: A novel type of heat transfer fluid known as hybrid nanofluids is used to improve the efficiency of heat exchangers. It is observed from literature evidence that hybrid nanofluids outperform single nanofluids in terms of thermal performance. This study aims to address the stagnation point flow induced by Williamson hybrid nanofluids across a vertical plate. This fluid is drenched under the influence of mixed convection in a Darcy–Forchheimer porous medium with heat source/sink and entropy generation. Design/methodology/approach: By applying the proper similarity transformation, the partial differential equations that represent the leading model of the flow problem are reduced to ordinary differential equations. For the boundary value problem of the fourth-order code (bvp4c), a built-in MATLAB finite difference code is used to tackle the flow problem and carry out the dual numerical solutions. Findings: The shear stress decreases, but the rate of heat transfer increases because of their greater influence on the permeability parameter and Weissenberg number for both solutions. The ability of hybrid nanofluids to strengthen heat transfer with the incorporation of a porous medium is demonstrated in this study. Practical implications: The findings may be highly beneficial in raising the energy efficiency of thermal systems. Originality/value: The originality of the research lies in the investigation of the Darcy–Forchheimer stagnation point flow of a Williamson hybrid nanofluid across a vertical plate, considering buoyancy forces, which introduces another layer of complexity to the flow problem. This aspect has not been extensively studied before. The results are verified and offer a very favorable balance with the acknowledged papers. [ABSTRACT FROM AUTHOR]

The article focuses on Archimedes' principle, exploring its origins, applications in various fields such as shipbuilding and aerohydrodynamics, and its relevance to buoyancy. Topics include the legendary story of King Hiero II and Archimedes, the practical implications of the principle in ship construction and navigation, and its broader application to airships and aerodynamics.

Purpose: This study aims to investigate the influence of wall curvature in a semicircular thermal annular system on magneto-nanofluidic flow, heat transfer and entropy generation. The analysis is conducted under constant cooling surface and fluid volume constraints. Design/methodology/approach: The mathematical equations describing the thermo-fluid flow in the semicircular system are solved using the finite element technique. Four different heating wall configurations are considered, varying the undulation numbers of the heated wall. Parametric variations of bottom wall undulation (f), buoyancy force characterized by the Rayleigh number (Ra), magnetic field strength represented by the Hartmann number (Ha) and inclination of the magnetic field (γ) on the overall thermal performance are studied extensively. Findings: This study reveals that the fluid circulation strength is maximum in the case of a flat bottom wall. The analysis shows that the bottom wall contour and other control parameters significantly influence fluid flow, entropy production and heat transfer. The modified heated wall with a single undulation exhibits the highest entropy production and thermal convection, leading to a heat transfer enhancement of up to 21.85% compared to a flat bottom. The magnetic field intensity and orientation have a significant effect on heat transfer and irreversibility production. Research limitations/implications: Further research can explore a wider range of parameter values, alternative heating wall profiles and boundary conditions to expand the understanding of magneto-nanofluidic flow in semicircular thermal systems. Originality/value: This study introduces a constraint-based analysis of magneto-nanofluidic thermal behavior in a complex semicircular thermal system, providing insights into the impact of wall curvature on heat transfer performance. The findings contribute to the design and optimization of thermal systems in various applications. [ABSTRACT FROM AUTHOR]

Gilbert Park recounts his experience on his maiden voyage in his Mitchell Classique 28 boat, which included encountering various technical troubles. Despite these challenges, Park successfully rescued two men and a dog from a capsized yacht. He shares the lessons he learned from this experience, including the importance of thorough maintenance, up-to-date electronic charts, and proper communication with the Coastguard. Park also emphasizes the significance of wearing buoyancy aids and following the "Float to Live" technique if unexpectedly in the water. [Extracted from the article]

Ophiolite obduction, the process during which part of the oceanic crust overlaps the continental margin, presents a challenge in geodynamic reconstructions of lithospheric processes. The difference in buoyancy between the dense oceanic crust and the relatively buoyant continental crust makes obduction of the oceanic crust difficult, if not impossible, if we only consider the buoyancy forces. The initial configuration of the oceanic basins must have specific thermal and geometric constraints to overcome the difficulties posed by the negative buoyancy. Here, we present a systematic investigation of the geometric and geodynamic parameters controlling the process of ophiolite emplacement. We show which parameters are the most important during ophiolite emplacement and the optimum geometries favouring this emplacement. We focus on 'Tethyan' ophiolites, which are characterized by a relatively small inferred basin size and are commonly found in the Mediterranean region. Based on a combination of parameters, we identify the configurations most susceptible to ophiolite obduction. Our models, in agreement with the geological data, show that to achieve ophiolite obduction, the obducted lithosphere must be young and the length of the ocean–continent transition zone must be relatively sharp. Supplementary material: Supplementary figures S1–S5, that are mentioned in the main text, are available at https://doi.org/10.6084/m9.figshare.c.6922526 Thematic collection: This article is part of the Ophiolites, melanges and blueschists collection available at: https://www.lyellcollection.org/topic/collections/ophiolites-melanges-and-blueschists [ABSTRACT FROM AUTHOR]

Purpose: One of the major challenges in the design of thermal equipment is to minimize the entropy production and enhance the thermal dissipation rate for improving energy efficiency of the devices. In several industrial applications, the structure of thermal device is cylindrical shape. In this regard, this paper aims to explore the impact of isothermal cylindrical solid block on nanofluid (Ag – H2O) convective flow and entropy generation in a cylindrical annular chamber subjected to different thermal conditions. Furthermore, the present study also addresses the structural impact of cylindrical solid block placed at the center of annular domain. Design/methodology/approach: The alternating direction implicit and successive over relaxation techniques are used in the current investigation to solve the coupled partial differential equations. Furthermore, estimation of average Nusselt number and total entropy generation involves integration and is achieved by Simpson and Trapezoidal's rules, respectively. Mesh independence checks have been carried out to ensure the accuracy of numerical results. Findings: Computations have been performed to analyze the simultaneous multiple influences, such as different thermal conditions, size and aspect ratio of the hot obstacle, Rayleigh number and nanoparticle shape on buoyancy-driven nanoliquid movement, heat dissipation, irreversibility distribution, cup-mixing temperature and performance evaluation criteria in an annular chamber. The computational results reveal that the nanoparticle shape and obstacle size produce conducive situation for increasing system's thermal efficiency. Furthermore, utilization of nonspherical shaped nanoparticles enhances the heat transfer rate with minimum entropy generation in the enclosure. Also, greater performance evaluation criteria has been noticed for larger obstacle for both uniform and nonuniform heating. Research limitations/implications: The current numerical investigation can be extended to further explore the thermal performance with different positions of solid obstacle, inclination angles, by applying Lorentz force, internal heat generation and so on numerically or experimentally. Originality/value: A pioneering numerical investigation on the structural influence of hot solid block on the convective nanofluid flow, energy transport and entropy production in an annular space has been analyzed. The results in the present study are novel, related to various modern industrial applications. These results could be used as a firsthand information for the design engineers to obtain highly efficient thermal systems. [ABSTRACT FROM AUTHOR]

We based an integrated petrological and petrophysical model for the Ediacaran crust of southern Britain on a review of the c. 570–550 Ma Charnian volcano-sedimentary complex. The latter was emplaced in a magmatic rift wedge within the juvenile continental crust of the c. 720–600 Ma Marches Terrane, a subduction magmatic domain formed at the margin of the Gondwana palaeocontinent. The Charnian magmatic arc is characterized by primitive island arc tholeiite to more evolved calc-alkaline compositions. The inversion of aeromagnetic potential field data and petrophysical modelling reveals details of the internal structure of the Charnian Domain, including a median rift, superimposed annular structures and partitioning lineaments. The modelling suggests that the arc foundation could incorporate magnetite-rich cumulates, which may explain the anomalous geophysical properties, including crustal thickness, rigidity and buoyancy. There is no evidence for significant tectonic displacement between the Charnian Domain and its Marches Terrane host. Instead, the domain likely occupies a wedge-shaped arc/marginal rift basin complex, propagated from a neighbouring ocean into the Gondwana margin. Contemporaneous volcanic rift successions in the Welsh Borderland and Wales of the 570–550 Ma Charnian magmatic phase developed in coeval ensialic rifts within less strongly extended Marches Terrane lithosphere. A comparable diversity of subduction-related magmatism is found in the Neogene–recent Hikurangi destructive margin of New Zealand, providing a plausible analogue for Charnian magmatism. Supplementary material: Supplementary Publication 1 (borehole geophysical log correlation; petrophysical data table; unannotated geophysical maps and sections) and Supplementary Publication 2 (geochemistry analytical conditions and data table) are available at https://doi.org/10.6084/m9.figshare.c.6805248 [ABSTRACT FROM AUTHOR]

Purpose: This study aims to examine the flow of unsteady mixed convective hybrid nanofluid over a rotating sphere with heat generation/absorption. The hybrid nanofluid contains different shapes of nanoparticles (copper [Cu] and aluminium oxide [Al2O3]) in the base fluid (water [H2O]). The influence of different shapes (sphere, brick, cylinder, platelets and blades) of nanoparticle in water-based hybrid nanofluid is also investigated. Design/methodology/approach: To analyse the nanomaterial, the flow model is established, and in doing so, the Prandtl's boundary layer theory is incorporated into the present model. The bvp4c approach, i.e. finite difference method, is used to find the numerical solution of differential equations that is controlling the fluid flow. The effect of relevant flow parameters on nanofluid temperature and velocity profile is demonstrated in detailed explanations using graphs and bar charts, whereas numerical results for Nusselt number and the skin's coefficient for various form parameters are presented in tabular form. Findings: The rate of heat transfer is least for spherical-shaped nanoparticle because of its smoothness, symmetricity and isotropic behaviour. The rate of heat transfer is highest for blade-shaped nanoparticles as compared to other shapes (brick, cylindrical and platelet) of nanoparticles because the blade-shaped nanoparticles causes comparatively more turbulence flow in the nanofluid than other shapes of nanoparticle. Heat generation affects the temperature distribution and, hence, the particle deposition rate. The absorption of heat extracts heat and reduce the temperature across the rotating sphere. The heat generation/absorption parameter plays an important role in establishing and maintaining the temperature around the rotating sphere. Research limitations/implications: The numerical study is valid with the exception of the fluctuation in density that results in the buoyancy force and the functional axisymmetric nanofluid transport has constant thermophysical characteristics. In addition, this investigation is also constrained by the assumptions that there is no viscosity dissipation, no surface slippage and no chemically activated species. The hybrid nanofluid Al2O3–Cu/H2O is an incompressible and diluted suspension. The single-phase hybrid nanofluid model is considered in which the relative velocity of water (H2O) and hybrid nanoparticles (Al2O3–Cu) is the same and they are in a state of thermal equilibrium. Practical implications: Study on convective flow across a revolving sphere has its applications found in electrolysis management, polymer deposition, medication transfer, cooling of spinning machinery segments, spin-stabilized missiles and other industrial and technical applications. Originality/value: The originality of the study is to investigate the effect of shape factor on the flow of electrically conducting hybrid nanofluid past a rotating sphere with heat generation/absorption and magnetic field. The results are validated and provide extremely positive balance with the recognised articles. The results of the study provide many appealing applications that merit further study of the problem. [ABSTRACT FROM AUTHOR]

A study on the entropy generation (EPG) of the laminar and mixed flow of alumina/water nanofluids (NFs) flow in a two-dimensional rectangular enclosure is examined using the Lattice Boltzmann method (LBM). The mixed convection flow is produced in the enclosure utilizing a moving wall and the Boussinesq approximation, which uses the buoyancy force. The moving wall, which is located at the top of the enclosure and has a low temperature, is insulated, as are the other three walls. The side of the enclosure is constantly subjected to a steady magnetic field (MFD). In the center of the enclosure, there are five hot obstacles whose heights range from 0.1 to 0.5. Their distance from the bottom wall and Richardson number (Ri) are also other variables of the problem. Finally, the EPG and Bejan number (Be) are estimated. The results demonstrate that enhancing the distance of obstacles from the bottom wall improves the amount of EPG and Be in such a way that an increment in the distance from 0.25 to 0.4 enhances the amount of total EPG and Be by 18.8% and 9.5%, respectively. An enhancement in the height of obstacles increases the amount of EPG, but the increase of Ri from 0.01 to 100 reduces the amount of EPG. The Be is higher in the parts of the enclosure where the temperature changes are greater. [ABSTRACT FROM AUTHOR]

The article investigates the principles of buoyancy by conducting experiments to understand why certain objects float while others sink in water, focusing specifically on the shape and displacement of objects.

This article presents two science experiments focusing on the properties of water, one involving pepper, baby powder, and dishwashing liquid to explore surface tension, and another using paper clips and dishwashing liquid to investigate buoyancy and surface tension. It aims to elucidate the behavior of different substances in water and the effects of dishwashing liquid on surface tension.

The article explores the concept of buoyancy by conducting various experiments to determine why certain objects float while others sink in water. It engages readers in hands-on activities, such as testing different materials and analyzing their properties to understand the principles behind floating and sinking. It introduces the historical context of Archimedes' discovery and the Archimedes Principle, shedding light on the scientific foundation of buoyancy.

The article present step by step instruction to explore the strength and properties of natural materials, includes a hair strength test using coins; the reaction of eggshells in vinegar; and a cotton ball race to observe how water temperature affects buoyancy.

According to an article in Science News titled "Getting up to speed," elite athletes would need perfect technique in order to reach the projected maximum speed in running or swimming. The article mentions that a now-banned swimsuit line from Speedo in the 2000s led to new records in the 50-meter freestyle, as the suits compressed swimmers' bodies and made them more buoyant. The compression reduced drag by making the swimmers' bodies more streamlined, while also increasing buoyancy by trapping air around their bodies. [Extracted from the article]

Purpose: Nanofluid research has piqued the interest of scientists due to its intriguing applications in nanoscience, biomedical and electrical engineering, medication delivery, biotechnology, food processing, chemotherapy and other fields. This paper aims to inspect the behavior of the mixed convection magnetohydrodynamic flow and heat transfer induced by a nonlinear stretching/shrinking sheet in a nanofluid with a convective boundary condition. Tiwari and Das mathematical nanofluid model is incorporated in the analysis. Design/methodology/approach: The mathematical model is initially transformed to a nondimensional form by using dimensionless variables. Then the nondimensional partial differential equations are further transformed to a set of similarity equations by using the similarity technique. These equations are solved numerically by the bvp4c function in MATLAB software. Findings: For a certain range of the stretching/shrinking parameter, two solutions are obtained. The friction factor and the heat transfer rate escalate due to suction parameter with adding nanoparticles volume fraction by almost 27.15% and 0.153% for the upper branch solution, while the friction factor declines by almost 30.10% but the heat transfer rate augments by 0.145% for the lower branch solution. Furthermore, the behavior of the nanoparticle volume fractions on the heat transfer rate behaves differently in the presence of the mixed convection effect. The temperature of fluid augments with increasing Biot number for both solutions. Originality/value: The present work considers the flow and heat transfer induced by a stretching/shrinking sheet in a nanofluid using the Tiwari–Das nanofluid model with a convective boundary condition, where the effect of the buoyancy force is taken into consideration. It is shown that two solutions are found for a certain range of the shrinking strength, while the solution is unique for the stretching case. This study is important for scientists working in the growing field of nanofluids to become familiar with the flow properties and behaviors of such nanofluids. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to present the effect of entropy generation on the unsteady flow of upper-convected Maxwell nanofluid past a wedge embedded in a porous medium in view of buoyancy force. Cattaneo-Christov double diffusion theory simulates the processes of energy phenomenon and mass transfer. Meanwhile, Brownian motion, thermophoresis and convective boundary conditions are discussed to further visualize the heat and mass transfer properties. Design/methodology/approach: Coupled ordinary differential equations are gained by appropriate similar transformations and these equations are manipulated by the Homotopy analysis method. Findings: The result is viewed that velocity distribution is a diminishing function with boosting the value of unsteadiness parameter. Moreover, fluid friction irreversibility is dominant as the enlargement in Brinkman number. Then controlling the temperature and concentration difference parameters can effectively regulate entropy generation. Originality/value: This paper aims to address the effect of entropy generation on unsteady flow, heat and mass transfer of upper-convected Maxwell nanofluid over a stretched wedge with Cattaneo-Christov double diffusion, which provides a theoretical basis for manufacturing production. [ABSTRACT FROM AUTHOR]

• The dynamic behavior of droplets floating through the holes is studied. • The recommended range of dimensionless parameter Bo m is given. • Magnetic fields can effectively control the generation of secondary droplets. In this study, we utilize the simplified lattice Boltzmann method (SLBM) to investigate numerically the motion of buoyancy-driven deformable ferrofluid droplets through the orifice of varying widths and depths in two-dimensional (2D) space. Positioned directly beneath a plate with a central hole, the magnetic fluid droplets undergo acceleration to meet the plate under the influence of buoyancy and magnetic forces. We investigate the impact of magnetic field strength (Bo m), pore ratio (PR), plate thickness ratio (WR), droplet viscosity (Re), and the plate's wettability (contact angle) on the dynamic behavior of ferrofluid droplets ascending through the orifice. Our results reveal significant effects on the efficiency and morphology of ferrofluid droplets passing through the hole. The introduction of a magnetic field facilitates a larger volume of liquid droplets passing through the hole at PR = 0.25. Moreover, increasing magnetic field intensity leads to the generation of secondary droplets during passage through the orifice. In practical applications, to prevent the generation of secondary droplets, we recommend Bo m < 3 when the pore ratio falls within 0.35 < PR < 0.45 and plate thickness ratio WR = 1. Additionally, with increasing obstacle thickness, ferrofluid droplets on the hydrophobic wall can pass through the orifice more easily. Furthermore, when the magnetic field strength exceeds a certain threshold (Bo m = 6.08), the droplets can pass through the orifice regardless of the wall's hydrophilicity or hydrophobicity. For practical applications with the pore ratio PR = 0.25 and plate thickness ratio WR > 1, we suggest Bo m > 3. [ABSTRACT FROM AUTHOR]

A recent study conducted at Aristotle University of Thessaloniki in Greece has explored ways to optimize the frying process of natural porous materials, such as potatoes, by enhancing heat and mass transfer phenomena. The study utilized a novel planetary fryer that employs simultaneous rotation around two vertical axes at different speeds to create horizontal acceleration values. The research aimed to achieve a more energy-efficient frying process, reduced cooking times, and a healthier product by lowering frying temperatures and decreasing the formation of harmful compounds. The findings have implications for food processing, potentially enhancing productivity while limiting operational costs. [Extracted from the article]

The analysis of heat and mass transfer in the movement of immiscible couple stress fluids through a curved channel whose walls are at two different temperatures is the focus of the current work. Immiscible fluids are subjected to an external magnetic field that is taken normal to the fluid's flow. For suction or injection in the flow, the channel walls are presumed to be porous. The buoyancy force, which is modelled using the Boussinesq approximation, and a constant pressure gradient cause the flow of the couple stress fluids in the curved channel. The highly non-linear coupled differential equations associated with the proposed work are solved with the use of the semi-analytic Homotopy Analysis Method. The semi-analytical expression of the various flow variables such as flow velocity, temperature, concentration, etc. is obtained by solving these non-linear differential equations after they have been non-dimensionalized by taking into account non-dimensional parameters. From the obtained results authors have noted how the two immiscible couple stress fluids' flow velocity, temperature, and concentration behaviour depend on the flow-effecting parameters, including the couple stress parameter, curvature parameter, Schmidt number, and so on. Further, the authors of the proposed work have analysed the effect of various flow parameters on heat and mass transfer. Since the authors have studied the two-phase flow of couple stress fluids in a porous walled curved channel together with the effect of magnetic field, the current model has various applications in the fields of crude oil extraction, filtration, nuclear reactor, and bio-mechanics. • We studied MHD flow of two couple stress fluids through porous walled curved channel. • We used the Homotopy Analysis Method for solving the non-linear coupled ODEs. • Effect of various flow parameters are shown on velocity and temperature profile. • Effect of curvature and magnetic parameter is shown on heat and mass transfer rate. • This model is useful in biofluid mechanics, petroleum industry, heating devices, etc. [ABSTRACT FROM AUTHOR]

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Purpose: This study aims to investigate the buoyancy-induced heat and mass transfer phenomena in a backward-facing-step (BFS) channel subjected to applied magnetic field using different types of nanofluid. Design/methodology/approach: Conservation equations of mass, momentum, energy and concentration are used through velocity-vorticity form of Navier–Stokes equations and solved using Galerkin's weighted residual finite element method. The density variation is handled by Boussinesq approximation caused by thermo-solutal buoyancy forces evolved at the channel bottom wall having high heat and concentration. Simulations were carried out for the variation of Hartmann number (0 to 100), buoyancy ratio (−10 to +10), three types of water-based nanofluid i.e. Fe3O4, Cu, Al2O3 at χ = 6%, Re = 200 and Ri = 0.1. Findings: The mutual interaction of magnetic force, inertial force and nature of thermal-solutal buoyancy forces play a significant role in the heat and mass transport phenomena. Results show that the size of the recirculation zone increases at N = 1 for aiding thermo-solutal buoyancy force, whereas the applied magnetic field dampened the fluid-convection process. With an increase in buoyancy ratio, Al2O3 nanoparticle shows a maximum 54% and 67% increase in convective heat and mass transfer, respectively at Ha = 20 followed by Fe3O4 and Cu. However, with increase in Ha the Nuavg and Shavg diminish by maximum 62.33% and 74.56%, respectively, for Fe3O4 nanoparticles at N = 5 followed by Al2O3 and Cu. Originality/value: This research study numerically examines the sensitivity of Fe3O4, Cu and Al2O3 nanoparticles in a magnetic field for buoyancy-induced mixed convective heat and mass transfer phenomena in a BFS channel, which was not analyzed earlier. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to numerically investigate the confined single-walled carbon nanotube-water nanofluid jet impingement heating of a cooled surface with a uniform heat flux in the presence of a porous layer. The analysis of the convective heat transfer mechanism is introduced considering the buoyancy force effect under local thermal non-equilibrium conditions. Design/methodology/approach: The governing equations for the nanofluid and solid phase are discretized by the finite volume method and the SIMPLE algorithm is used to solve these equations. Findings: It is observed that there is an increase in a local variation of temperature along the upper wall with increasing Reynolds, Darcy and Grashof numbers. For given parameters, the optimum values of thermal conductivity ratio and porous layer thickness leading to better heating on the upper wall are found as Kr = 1.0 and S = 0.5, respectively. The maximum and minimum values of temperature on the upper wall are obtained in the case of higher nanoparticle volume fraction at Re = 100, however, the temperature values get higher along the upper wall with increasing nanoparticle volume fraction at Re = 300. Originality/value: The effects of various parameters, such as Reynolds number, Darcy number and Grashof number, on thermal behavior and nanofluid flow are examined to determine the desirable heating conditions for the upper wall. This paper provides a solution to problems such as icing on the surface with a suitable thermal design and optimum geometric configuration. [ABSTRACT FROM AUTHOR]

The article reports that the BOTE Zeppelin Aero 10 removes most of the obstacles to owning a fishing kayak. Topics include considered the smallest, lightest and most versatile kayak on the water, the Zeppelin leaves no excuse for being stuck on dry land; and examines the BOTE Zeppelin Aero 10 is only 10 feet long with a stable 38-inch beam.

Purpose: The purpose of this study is to simulate the thermo-solutal convection resulting from a circular cylinder hanging in a rod inside a ∧-shaped cavity. Design/methodology/approach: The two dimensional ∧-shaped cavity is filled by Al2O3-water nanofluid and saturated by three different levels of heterogeneous porous media. An incompressible smoothed particle hydrodynamics (ISPH) method is adopted to solve the governing equations of the present problem. The present simulations have been performed for the alteration of buoyancy ratio (−2≤N≤2) , radius of a circular cylinder (0.05≤Rc≤0.3) , a height of a rod (0.1≤Lh≤0.4) , Darcy parameter (10−3≤Da≤10−5) , Lewis number (1≤Le≤40) , solid volume fraction (0≤ϕ≤0.06) , porous levels (0≤η1=η2≤1.5) and various boundary-wall conditions. Findings: The performed numerical simulations indicated the importance of embedded shapes on the distributions of temperature, concentration and velocity fields inside ∧-shaped cavity. Increasing buoyancy ratio parameter enhances thermo-solutal convection and nanofluid velocity. Adiabatic conditions of the vertical-walls of ∧-shaped cavity augment the distributions of the temperature and concentration. Regardless the Darcy parameter, a homogeneous porous medium gives the lowest values of a nanofluid velocity. Originality/value: ISPH method is used to simulate thermo-solutal convection of a nanofluid inside a novel ∧-shaped cavity containing a novel embedded shape and heterogeneous porous media. [ABSTRACT FROM AUTHOR]

This work concerns solving optimisation problems where the objective function is expressed as a Choquet integral. This objective generalises a linear objective function (with positive weights) and allows for interaction to be modeled between coalitions of the decision variables. We leverage results from optimising the ordered weighted averaging (OWA) operator and propose efficient solution approaches for the asymmetric objectives both for the simplest case of a single constraint and then for multiple comonotone constraints. To solve problems with a large number of variables, we rely on the so-called antibuoyancy property, previously applied to OWA weights, and which we extend to general fuzzy measures. This characterisation not only facilitates a restriction of the domain on which the solution lies but also allows us to relate the Choquet integral's behavior in such cases to the Pigou-Dalton progressive transfers principle. We characterise the Choquet integrals consistent with the Pigou-Dalton principle. Theoretical results are supported by numerical experiments, which illustrate significant gains in performance. Our results offer opportunities for scalability to a much higher number of variables. [ABSTRACT FROM AUTHOR]

Lattice Boltzmann method (LBM) scheme is adopted to simulate the heat transfer processes inside isolated phase and three-phase enclosure gas insulated switchgear (GIS) capsules. D2Q9 fluid flow and thermal Lattice Boltzmann equations (LBEs) are solved through streaming and collision processes. Buoyancy force driven by natural convection is considered by the Boussinesq model. Power losses and thermal boundary conditions are obtained from closed formulas. Numerical results by LBM simulations are compared with those from physical experiments and conventional CFD simulations. Results show that LBM scheme could provide a simple and efficient alternative tool in the flow-thermal simulation of GIS equipment with desirable accuracy. Thermal performances of GIS capsule filled with different insulation gas mixtures (SF6, N2, CF4, CO2, CF3I) are then analyzed. Results show that upper conductors of three-phase GIS has larger temperature rise than lower conductor due to the natural convection effect. Conductor temperature rise inside gas mixture increases with the increase of second gas (N2, CO2, CF4) fraction. The thermal performance of GIS capsule could be reduced with the presentation of insulation gas mixtures. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to address various works on mixed convection and proposes 10 unified models (Models 1–10) based on various thermal and kinematic conditions of the boundary walls, thermal conditions and/ or kinematics of objects embedded in the cavities and kinematics of external flow field through the ventilation ports. Experimental works on mixed convection have also been addressed. Design/methodology/approach: This review is based on 10 unified models on mixed convection within cavities. Models 1–5 involve mixed convection based on the movement of single or double walls subjected to various temperature boundary conditions. Model 6 elucidates mixed convection due to the movement of single or double walls of cavities containing discrete heaters at the stationary wall(s). Model 7A focuses mixed convection based on the movement of wall(s) for cavities containing stationary solid obstacles (hot or cold or adiabatic) whereas Model 7B elucidates mixed convection based on the rotation of solid cylinders (hot or conductive or adiabatic) within the cavities enclosed by stationary or moving wall(s). Model 8 is based on mixed convection due to the flow of air through ventilation ports of cavities (with or without adiabatic baffles) subjected to hot and adiabatic walls. Models 9 and 10 elucidate mixed convection due to flow of air through ventilation ports of cavities involving discrete heaters and/or solid obstacles (conductive or hot) at various locations within cavities. Findings: Mixed convection plays an important role for various processes based on convection pattern and heat transfer rate. An important dimensionless number, Richardson number (Ri) identifies various convection regimes (forced, mixed and natural convection). Generalized models also depict the role of "aiding" and "opposing" flow and combination of both on mixed convection processes. Aiding flow (interaction of buoyancy and inertial forces in the same direction) may result in the augmentation of the heat transfer rate whereas opposing flow (interaction of buoyancy and inertial forces in the opposite directions) may result in decrease of the heat transfer rate. Works involving fluid media, porous media and nanofluids (with magnetohydrodynamics) have been highlighted. Various numerical and experimental works on mixed convection have been elucidated. Flow and thermal maps associated with the heat transfer rate for a few representative cases of unified models [Models 1–10] have been elucidated involving specific dimensionless numbers. Originality/value: This review paper will provide guidelines for optimal design/operation involving mixed convection processing applications. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to develop a subgrid-scale (SGS) model for large eddy simulation (LES) of buoyancy- and thermally driven transitional and turbulent flows and further examine its performance. Design/methodology/approach: Favre-filtered, non-dimensional LES equations are solved using non-dissipative, fully implicit, kinetic energy conserving, finite-volume algorithm which uses an iterative predictor-corrector approach based on pressure correction. Also, to develop a new SGS model which accounts for buoyancy, turbulent generation term in SGS viscosity is properly modified and enhanced by buoyancy production. Findings: The proposed model has been successfully applied to turbulent Rayleigh–Bénard convection. The results show that the model is able to reproduce the complex physics of turbulent thermal convection. In comparison with the original wall-adapting local eddy-viscosity (WALE) and buoyancy-modified (BM) Smagorinsky models, turbulent diagnostics predicted by the new model are in better agreement with direct numerical simulation. Originality/value: A BM variant of the WALE SGS model is newly developed and analyzed. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to focus on the natural convective flow analysis of micropolar nanofluid fluid in a rectangular vertical container. A heated source is placed in the lower wall to generate the internal flow. In further assumptions, the left/right wall are kept cool, while the upper and lower remaining portions are insulated. Free convection prevails in the regime because of thermal difference in-between the lower warmer and upper colder region. Design/methodology/approach: The physical setup owns mathematical framework in-terms of non-linear partial differential equations. For the solution purpose of the differential system, finite volume method is adopted. The interesting features of the flow along with thermal transportation involve both translational and rotational movement of fluid particles. Findings: Performing the simulations towards flow controlling variables the outputs are put together in contour maps and line graphs. It is indicated that the variations in flow profile mass concentration and temperature field augments at higher Rayleigh parameter because of stronger buoyancy effects. Higher viscosity coefficient implies decrease in flow and thermal transportation. Further, the average heat transfer rate also grows by increasing both the Rayleigh parameter and heated source length. Originality/value: To the best of the authors' knowledge, no such study has been addressed yet. Further, the results are validated by comparing with previously published work. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to use an incompressible smoothed particle hydrodynamics (ISPH) method for simulating buoyancy ratio and magnetic field effects on double diffusive natural convection of a cooper-water nanofluid in a cavity. An open pipe is embedded inside the center of a cavity, and it is occupied by solid particles. Design/methodology/approach: The dimensionless governing equations in Lagrangian form were solved by ISPH method. Two different thermal conditions were considered for the solid particles. The actions of the solid particles were tracked inside a cavity. The effects of Hartman parameter, Rayleigh number, nanoparticles volume fraction and Lewis number on features of heat and mass transfer and flow field were tested. Findings: The results showed that the buoyancy ratio changes the directions of the solid particles diffusion in a cavity. The hot solid particles were raised upwards at aiding mode (N > 0) and downwards at an opposing mode (N < 0). A comparison is made with experimental and numerical simulation results, and it showed a well agreement. Originality/value: Novel studies for the impacts of buoyancy ratio on the diffusion of solid particles embedded in an open pipe during double-diffusive flow were conducted. [ABSTRACT FROM AUTHOR]

A new study conducted by researchers from Islamic Azad University in Iran explores the correlation between self-compassion, empathy, and academic well-being in high school students. The study found significant positive correlations between self-compassion and academic well-being, as well as between self-compassion and academic buoyancy. Additionally, there was a positive correlation between the benefits of empathy and academic buoyancy. The research suggests that interventions aimed at enhancing students' academic well-being could be developed based on these findings. The study was conducted using a descriptive-correlational approach and involved 384 high school students in Ahvaz, Iran. [Extracted from the article]

A recent study conducted by Yantai University in China has explored the flow of nanofluids around a vertically stretchable cylinder. The study takes into account convective boundary conditions, activation energy, and gyrotactic microorganisms with buoyancy effects. The findings of the study have implications for various fields, including biomedical engineering, the oil and gas industry, heat exchangers, and renewable energy. The research concludes that there is agreement between these findings and previous scholarly research. The study has been peer-reviewed and more information can be obtained from the authors. [Extracted from the article]

A report from Kocaeli University in Turkey discusses the importance of the emotional well-being of disaster response workers (DRWs) in sustainable public health and disaster management. The study examines the roles of servant leadership (SL) and workplace buoyancy (WB) in addressing emotional exhaustion among DRWs. The analysis reveals that SL and WB play key roles in reducing emotional exhaustion, with WB partially mediating the relationship between SL and emotional exhaustion. The study provides valuable suggestions for policymakers and managers to enhance the resilience and well-being of DRWs, emphasizing the need for integrated, sustainable responses in disaster relief efforts. [Extracted from the article]

A recent report from Imperial College London discusses the use of virtual reality (VR) and simulation in surgical training. The study aimed to compare the effect of using VR versus mannequin-based simulation on academic buoyancy, which is a learner's ability to deal with academic setbacks. The research found that VR participants had increased academic buoyancy scores and higher overall simulation scores compared to those using mannequin-based simulation. The study suggests that VR may provide a more comfortable environment for trainees to improve their clinical skills and boost confidence. Further research is needed to determine if spaced VR teaching sessions can lead to long-term improvements in resilience. [Extracted from the article]

A study conducted by researchers at Hanyang University in Seoul, South Korea, focuses on analyzing the heat and velocity transfer rate in a stretching sheet with ternary hybrid nanofluid flow through a porous medium. The study examines the impact of suction and buoyancy effects on the flow, using two different types of hybrid nanofluids. Lie group transformations and a boundary value problem solver were used to solve the resulting ordinary differential equations. The study concludes that a neural network, composed of artificial neurons or nodes, can be used to examine the flow pattern of a fluid. [Extracted from the article]

A recent report from Chongqing, People's Republic of China, discusses the concept of "teacher immunity" in the field of language teacher psychology. The research conducted a study with 384 primary language teachers and found that teacher immunity can significantly predict their psychological well-being, buoyancy, and engagement. The study's conclusions have potential implications for advancing education in terms of promoting psychological well-being and engagement. For more information, readers can refer to the journal article "Primary school teachers are immune: a journey in the sea of psychological well-being, buoyancy, and engagement" published in BMC Psychology. [Extracted from the article]

This article discusses a performance of Mahler's Symphony 8, also known as Symphony of a Thousand, conducted by Osmo Vänskä and performed by the Minnesota Orchestra. The author praises Vänskä's buoyant and judicious approach to the piece, noting the expressive and disturbing violin solos. They also highlight the luscious soprano performances by Carolyn Sampson and Jacquelyn Wagner, while noting that Barry Banks struggled with his role. The article concludes by praising the natural and well-balanced sonics of the recording. [Extracted from the article]

A recent reader survey conducted by Practical Boat Owner (PBO) revealed that the PBO community is interested in reading more boat and gear reviews, practical DIY step-by-step articles, and seamanship articles. The survey also provided insights into the readership, showing that most respondents have been involved in sailing for over 20 years, sail solo or double-handed, own second-hand boats, and perform their own boat maintenance. PBO plans to deliver more of the content that readers have expressed interest in and will continue to focus on the practical aspects of boating. Additionally, the Seadog section of the magazine will now be sponsored by Exposure Marine, who will provide safety-focused OLAS Tags for man (and dog) overboard recovery. [Extracted from the article]

Purpose: The purpose of this study is to numerically analyze the mixed convection and entropy generation in an annulus with a rotating heated inner cylinder for single-wall carbon nanotube (SWCNT)–water nanofluid flow using local thermal nonequilibrium (LTNE) model. An examination of the system behavior is presented considering the heat-generating solid phase inside the porous layer partly filled at the inner surface of the outer cylinder. Design/methodology/approach: The discretized governing equations for nanofluid and porous layer by means of the finite volume method are solved by using the SIMPLE algorithm. Findings: It is found that the buoyancy force and rotational effect have an important impact on the change of the strength of streamlines and isotherms for nanofluid flow. The minimum average Nusselt number on the inner cylinder is obtained at Ra$_E$ = 10$^4$, and the minimum total entropy generation is found at Re = 400 for given parameters. The entropy generation minimization is determined in case of different nanoparticle volume fractions. It is observed that at the same external Rayleigh numbers, the LTNE condition obtained with internal heat generation is very different from that without heat generation. Originality/value: To the best of the authors' knowledge, there is no previous paper presenting mixed convection and entropy generation of SWCNT–water nanofluid in a porous annulus under LTNE condition. The addition of nanoparticles to based fluid leads to a decrease in the value of minimum total entropy generation. Thus, using nanofluid has a significant role in the thermal design and optimization of heat transfer applications. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to examine the hybrid nanofluid flow towards a stagnation point on an exponentially stretching/shrinking vertical sheet with buoyancy effects. Design/methodology/approach: Here, the authors consider copper (Cu) and alumina (Al2O3) as hybrid nanoparticles while water as the base fluid. The governing equations are reduced to the similarity equations using similarity transformations. The resulting equations are programmed in Matlab software through the bvp4c solver to obtain their solutions. Findings: The authors found that the heat transfer rate is greater for Al2O3-Cu/water hybrid nanofluid if compared to Cu/water nanofluid. Besides, the non-uniqueness of the solutions is observed for certain physical parameters. The authors also notice that the bifurcation of the solutions occurs in the downward buoyant force and the shrinking regions. In addition, the first solution of the skin friction and heat transfer coefficients increase with the added hybrid nanoparticles and the mixed convection parameter. The temporal stability analysis shows that one of the solutions is stable as time evolves. Originality/value: The present work is dealing with the problem of a mixed convection flow of a hybrid nanofluid towards a stagnation point on an exponentially stretching/shrinking vertical sheet, with the buoyancy effects is taken into consideration. The authors show that two solutions are obtained for a single value of parameter for both stretching and shrinking cases, as well as for both buoyancy aiding and opposing flows. A temporal stability analysis then shows that only one of the solutions is stable and physically reliable as time evolves. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to apply the incompressible smoothed particle hydrodynamics (ISPH) method to simulate the natural convection flow from an inner heated Y-fin inside Y-shaped enclosure filled with nanofluid. Design/methodology/approach: The dimensionless governing partial differential equations are described in the Lagrangian form and solved by an implicit scheme of the ISPH method. The embedded Y-fin is kept at a high temperature Th with variable heights during the simulations. The lower area of Y-shaped enclosure is squared with width L = 1 m and its side-walls are kept at a low temperature Tc. The upper area of the Y-shaped enclosure is V-shaped with width 0.5 L for each side and its walls are adiabatic. Findings: The performed simulations revealed that the height of the inner heated Y-fin plays an important role in the heat transfer and fluid flow inside the Y-shaped enclosure, where it enhances the heat transfer. Rayleigh number augments the buoyancy force inside the Y-shaped enclosure and, consequently, it has a strong impact on temperature distributions and strength of the fluid flow inside Y-shaped enclosure. Adding more concentration of the nanofluid until 10% has a slight effect on the temperature distributions and it reduces the strength of the fluid flow inside Y-shaped enclosure. In addition, the average Nusselt number is measured along the inner heated Y-fin and it grows as the Rayleigh number increases. The average Nusselt number is decreasing by adding more concentrations of the nanofluid. Originality/value: An improved ISPH method is used to simulate the natural convection flow of Y-fin embedded in the Y-shaped enclosure filled with a nanofluid. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to examine the impact of activation energy with binary chemical reaction for unsteady flow on permeable stretching surface. Design/methodology/approach: The simultaneous effects of multiple slip and magneto-hydrodynamic effects at the boundary are taken into account. The thermal buoyancy parameter and thermal radiation are included in both energy and momentum equations, while expression of activation energy is considered in concentration equation. Three-stage Lobatto IIIa finite difference collocation technique with bvp4c MATLAB package is used to obtained numerical results. Findings: The influence of key elements (Schmidt number, buoyancy force ratio factor, factor of radiation, magnetic element, unsteadiness factor, suction/injection parameter, Prandtl number, activation energy, chemical reaction rate parameter, heat source and sink parameters, velocity, thermal and concentration slips, porosity parameter and temperature difference parameter) on velocity, temperature and concentration profiles are illustrated pictorially. A detailed discussion is presented to see how the graphical aspects justify the physical prospect. Originality/value: In the best of author's knowledge, this work is yet not available in existing literature. [ABSTRACT FROM AUTHOR]

The article discusses a new type of buoyancy model can be used to understand the source of residual oil zones (ROZs), and help determine the likelihood that economically viable recoverable oil resides in transition zones (TZs) of imbibition reservoirs. It mentions that the next generation carbon dioxide (CO2) enhanced oil recovery (EOR) projects are undertaken with the hope of recovering tertiary oil while sequestering and storing a greenhouse gas.

The design allows for 27 different size confi gurations and lets you fi ne-tune the fi t. That's good because the waist straps in particular have a relatively narrow adjustment range, and our testers found the best sizing sometimes required different size components. A pair of trim pockets mounted on the single tank band are handy, although some testers wished for a higher placement to better shift weight. A smattering of D-rings and web loops, and a drop-down cargo pocket that's big enough but tricky to access under the weight pocket, left testers wishing for a few more places for their essentials. Similarly, you'll pay for your appetite, hence the weight (15 pounds and change) and tally for the fully loaded rig we tested: Deep Ocean 2.0 wing, Comfort Harness III with crotch strap, stainless back plate, back pad with weight pockets, integrated weight pockets and utility pocket. [Extracted from the article]

A recent study conducted by China Pharmaceutical University explores the impact of anxiety and demotivation on academic buoyancy and autonomy in online assessment. The researchers distributed questionnaires to 392 university students in China and used confirmatory factor analysis and structural equation modeling to analyze the data. The findings suggest that students who experience less anxiety and demotivation are more buoyant and autonomous. The study highlights the potential for improving language education and assessment and emphasizes the importance of considering students' psychological and emotional well-being in educational experiences. [Extracted from the article]