EMHD hybrid squeezing nanofluid flow with variable features and irreversibility analysis

This study discusses the entropy generation analysis of electro-magneto hydrodynamics (EMHD) hybrid nanofluid copper oxide-aluminum oxide/ethylene glycol (CuO-Al2O3/C2H6O2) flow amidst two rotating disks in a porous media having variable thermophysical features. The addition of the surface catalyzed to the homogeneous-heterogeneous reactions shorten the reaction time that may be taken as a novel aspect of the undertaken EMHD hybrid nanofluid squeezing flow. The inimitability of the assumed model is supplemented by considering the simultaneous effects of the variable thermal conductivity and viscosity. To simplify the governing flow model, suitable conversions are used to accurately translate the obtained partial differential equations to ordinary differential equations. The flow and energy transfer characteristics are computed and sketched graphically by using the Keller box scheme. The outcomes reveal that the drag force in radial and tangential directions depict the opposing trend for variable viscosity parameter. Furthermore, the normal magnetic and transverse electric fields play an essential role in the alignment of the nanoparticles throughout the flow field. The validation of the envisaged model is also a part of this study.

A Box to Put the Baby in: UK Parent Perceptions of Two Baby Box Programmes Promoted for Infant Sleep

Between 2016 and 2019, two different infant sleeping-box interventions were implemented in England: (1) shallow polypropylene baby boxes were distributed via a feasibility study to families with Sudden Infant Death Syndrome (SIDS) risk factors; and (2) a commercial–health system partnership scheme distributed cardboard baby boxes to new mothers in particular locations. We conducted parent evaluations of both interventions at the time of implementation. The views of 79 parents receiving polypropylene boxes and 77 parents receiving cardboard boxes were captured using online questionnaires and telephone interviews. Participants provided feedback on education received about using the box, their perception of the box design and materials, their experiences of using the box they received, and whether they would recommend it to others. Parents appreciated that both boxes provided a portable space to place their baby near them anywhere in the home, discouraging other riskier practices. The polypropylene box was rated more favourably regarding transparency, hygiene, and portability outside the home. A minority of parents found the idea of putting their baby in any box unappealing; however, younger mothers and smokers particularly appreciated the ability to safely co-sleep with their babies using the shallower box. Overall, the versatility of the polypropylene box scheme was more positively evaluated than the cardboard baby box scheme, which, stripped of its social value as part of a larger welfare provision, had minimal value for parents that received it.

Entropy Optimization of First-Grade Viscoelastic Nanofluid Flow over a Stretching Sheet by Using Classical Keller-Box Scheme

Nanofluids have better surface stability, thermal absorption, and distribution capacities are produced as heat transfer fluids. In current nanofluid-transport studies, together with the heat transfer mechanisms, entropy reduction in thermo- and non-Newtonian nanofluid models with changing thermophysical characteristics is heavily addressed. The entropy production is examined as thermodynamically stable first-grade viscoelastic nanofluid (FGVNF) flow over a flat penetrable, porous barrier. The uniform porous horizontal stretching of the surface in a Darcy type of pore media results in a fluid motion disturbance. In addition, this study also includes the effects of thermal radiation, viscous dissipation, and slip conditions at the border. Under boundary layer flow and Rosseland approximations, the governing mathematical equations defining the physical features of the FGVNF flow and heat transfer models are summarized. The governing nonlinear partial differential equation is transformed by similarity variables to achieve solutions in nonlinear ordinary differential equations. Approximative solutions for reduced ordinary differential equations are obtained by the Keller Box Scheme. Two distinct types of nanofluids, Copper-Engine Oil (Cu-EO) and Zirconium Dioxide-Engine Oil (ZrO2-EO), are considered in this research. The graphs are produced to examine the effects of the different physical factors for the speed, temperature, and entropy distributions. The significant findings of this study are that the critical characteristics of (boundary layer) BL collectively promote temperature variation, including slip speed, diverse thermal conductivity, and non-Newtonian first-grade viscoelastic nanofluid, the concentration of nanoparticles as well as thermal radiation, and a high porous media. The other noteworthy observation of this study demonstrates that the (Cu-EO) FGVNF is a better conductor than (ZrO2-EO) FGVNF transmission. The entropy of the system grows the Deborah number and volume fraction parameter.

Behavioural change box? Applying the COM-B model to understand behavioural triggers that support consumption of fruits and vegetable among subscribers of a fruit and vegetable box scheme

Objective To understand the key mechanisms that support healthy dietary habits promoted by fruit and vegetable (F&V) box schemes, testing relevant behaviour change triggers identified under the COM-B model in an evaluation research study of a Portuguese F&V box scheme (PROVE). Design Correlation study with a post-test-only non-equivalent group design based on survey data. The mechanisms underpinning the differences between subscribers and non-subscribers are operationalized as mediation effects. Data availability, theoretical relevance and empirical validation supported the selection and testing of four potential mediators for the effects of subscribing to the box scheme on F&V consumption. These estimations derive from the coefficients of a structural equation model combined with the product coefficient approach and Sobel test. Setting The study is part of a wider evaluation study on the impact of the PROVE box scheme on sustainability, health, and equity. Participants A sample of PROVE box subscribers (n=294) was compared with a matched subsample of non-subscribers (n=571) in a nationally representative survey. Results Subscribing to the PROVE box correlates with an increased probability of eating at least five portions of F&V, irrespective of differences in age, education, and perceived economic difficulties. Diet quality perceptions, and more robustly, the strength of meal habits and household availability were identified as relevant mediators. Conclusions The subscription to an F&V box scheme is connected with proximal context that enables the consumption of F&V by ensuring more readily available F&V and better situational conditions associated with healthier meal habits.

A Semi-Linear Elliptic Model for a Circular Membrane MEMS Device Considering the Effect of the Fringing Field

In this study, an accurate analytic semi-linear elliptic differential model for a circular membrane MEMS device, which considers the effect of the fringing field on the membrane curvature recovering, is presented. A novel algebraic condition, related to the membrane electromechanical properties, able to govern the uniqueness of the solution, is also demonstrated. Numerical results for the membrane profile, obtained by using the Shooting techniques, the Keller–Box scheme, and the III/IV Stage Lobatto IIIa formulas, have been carried out, and their performances have been compared. The convergence conditions, and the possible presence of ghost solutions, have been evaluated and discussed. Finally, a practical criterion for choosing the membrane material as a function of the MEMS specific application is presented.

Numerical Simulation of Heat Transfer Flow Subject to MHD of Williamson Nanofluid with Thermal Radiation

In this paper, heat transfer and entropy of steady Williamson nanofluid flow based on the fundamental symmetry is studied. The fluid is positioned over a stretched flat surface moving non-uniformly. Nanofluid is analyzed for its flow and thermal transport properties by consigning it to a convectively heated slippery surface. Thermal conductivity is assumed to be varied with temperature impacted by thermal radiation along with axisymmetric magnetohydrodynamics (MHD). Boundary layer approximations lead to partial differential equations, which are transformed into ordinary differential equations in light of a single phase model accounting for Cu-water and TiO2-water nanofluids. The resulting ODEs are solved via a finite difference based Keller box scheme. Various formidable physical parameters affecting fluid movement, difference in temperature, system entropy, skin friction and Nusselt number around the boundary are presented graphically and numerically discussed. It has also been observed that the nanofluid based on Cu-water is identified as a superior thermal conductor rather than TiO2-water based nanofluid.

Finite Difference Solution for MHD Flow Between Two Parallel Permeable Plates with Velocity Slip

The problem of Hydromagnetic steady laminar flow of an electrically conducting viscous incompressible fluid between parallel pates has been studied. The nonzero tangential slip velocity at the permeable boundary is considered. A numerical solution is derived for the governing nonlinear boundary value problem using a novel Keller box scheme. The effect of suction Reynold number , Hartman number and slip coefficient on derived quantities such as velocity filed and skin friction at the boundaries are analyzed. The physical significance of the flow parameters is also discussed.

Multi-Symplectic Method for the Logarithmic-KdV Equation

The multi-symplectic integrator, as a numerical integration approach with symmetry, is known to have the characteristic of preserving the qualitative features and geometric properties of certain systems. Using the multi-symplectic integrator, the numerical simulation of the Gaussian solitary wave propagation of the logarithmic Korteweg–de Vries (logarithmic-KdV) equation was investigated. The multi-symplectic formulation of the logarithmic-KdV equation was explored by introducing some intermediate variables. A fully implicit version of the centered box scheme was used to discretize the multi-symplectic equations. In addition, numerical experiments were carried out to show the conservative properties of the proposed scheme.

The Diversity of Organic Box Schemes in Europe—An Exploratory Study in Four Countries

Box schemes provide an opportunity to scale up local organic food systems by aggregating products from multiple producers and efficiently delivering them to consumers. However, there is limited knowledge about the overall organic box scheme landscape and how it develops. This article explores organic box schemes in four European countries and thus contributes by comparing box schemes of different sizes in different geographical and organisational contexts. Survey results from 44 box schemes were used to analyse box schemes in relation to size and growth, organisation, communication with customers, delivery modes, distances travelled by produce and boxes, and values adhered to. Although the surveyed box schemes differed in size and organisation, similarities between box schemes were found in many aspects. For example, most surveyed box schemes had grown considerably since their start, and wished to grow further, and they all rated certain values as important. A tendency for larger box schemes to offer more imported produce, to have operated for a longer time, and to use social media for advertising more often was found. Despite the heterogeneity of the box schemes in the survey, we conclude that box schemes are a useful category to explore in the sustainability transition of food systems.