Heat Transfer Attributes of Gold–Silver–Blood Hybrid Nanomaterial Flow in an EMHD Peristaltic Channel with Activation Energy

The heat enhancement in hybrid nanofluid flow through the peristaltic mechanism has received great attention due to its occurrence in many engineering and biomedical systems, such as flow through canals, the cavity flow model and biomedicine. Therefore, the aim of the current study was to discuss the hybrid nanofluid flow in a symmetric peristaltic channel with diverse effects, such as electromagnetohydrodynamics (EMHD), activation energy, gyrotactic microorganisms and solar radiation. The equations governing this motion were simplified under the approximations of a low Reynolds number (LRN), a long wavelength (LWL) and Debye–Hückel linearization (DHL). The numerical solutions for the non-dimensional system of equations were tackled using the com-putational software Mathematica. The influences of diverse physical parameters on the flow and thermal characteristics were computed through pictorial interpretations. It was concluded from the results that the thermophoresis parameter and Grashof number increased the hybrid nanofluid velocity near the right wall. The nanoparticle temperature decreased with the radiation parameter and Schmidt number. The activation energy and radiation enhanced the nanoparticle volume fraction, and motile microorganisms decreased with an increase in the Peclet number and Schmidt number. The applications of the current investigation include chyme flow in the gastrointestinal tract, the control of blood flow during surgery by altering the magnetic field and novel drug delivery systems in pharmacological engineering.This work was supported by the Deanship of Scientific Research, Vice Presidency for Graduate Studies and Scientific Research, King Faisal University, Saudi Arabia (Project No. AN00052)

Numerical Simulation of Magnetic Dipole Flow Over a Stretching Sheet in the Presence of Non-Uniform Heat Source/Sink

The main objective of current communication is to present a mathematical model and numerical simulation for momentum and heat transference characteristics of Maxwell nanofluid flow over a stretching sheet. Further, magnetic dipole, non-uniform heat source/sink, and chemical reaction effects are considered. By using well-known similarity transformation, formulated flow equations are modelled into OD equations. Numerical solutions of the governing flow equations are attained by utilizing the shooting method consolidated with the fourth-order Runge-Kutta with shooting system. Graphical results are deliberated and scrutinized for the consequence of different parameters on fluid characteristics. Results reveal that the temperature profile accelerates for diverse values of space dependent parameter, but it shows opposite behaviour for escalated integrity of temperature dependent parameter

Effect of Magnetic Baffles and Magnetic Nanofluid on Thermo-Hydraulic Characteristics of Dimple Mini Channel for Thermal Energy Applications

The combined effect of a magnetic baffle and a dimple turbulator on the heat transfer and pressure drop is investigated computationally in a mini channel. Fe3O4 magnetic nanofluid is used as a working fluid. The Reynolds number (Re) is varied from 150 to 210 and the magnetic field intensities range from 1200 G to 2000 G. Finite-volume based commercial computational fluid dynamics (CFD) solver ANSYS-Fluent 18.1 was used for the numerical simulations. A laminar viscous model is used with pressure-velocity coupling along with second-order upwind discretization and QUICK scheme for discretizing the momentum and energy equations. The results show that there is an increase of 3.53%, 10.77%, and 25.39% in the Nusselt numbers when the magnetic fields of 1200 G, 1500 G and 2000 G, respectively, are applied at x = 15 mm, as compared to the flow without a magnetic field when the pitch = 10 mm. These values change to 1.51%, 6.14% and 18.47% for a pitch = 5 mm and 0.85%, 4.33%, and 15.25% for a pitch = 2.5 mm, when compared to the flow without a magnetic field in the respective geometries. When the two sources are placed at x = 7.5 mm and 15 mm, there is an increase of 4.52%, 13.93%, and 33.08% in the Nusselt numbers when magnetic fields of 1200 G, 1500 G, and 2000 G are applied when the pitch = 10 mm. The increment changed to 1.82%, 8.16%, and 22.31% for a pitch = 5 mm and 1.01%, 5.96%, and 21.38% for a pitch = 2.5 mm. This clearly shows that the two sources at the front have a higher increment in the Nusselt numbers compared to one source, due to higher turbulence. In addition, there is a decrease in the pressure drop of 10.82%, 16.778%, and 26.75% when magnetic fields of 1200 G, 1500 G, and 2000 G, respectively, are applied at x = 15 mm, as compared to flow without magnetic field when the pitch = 10 mm. These values change to 2.46%, 4.98%, and 8.54% for a pitch = 5 mm and 1.62%, 3.52%, and 4.78% for a pitch = 2.5 mm, when compared to flow without magnetic field in the respective geometries. When two sources are placed at x = 7.5 mm and 15 mm, there is an decrease of 19.02%, 31.3%, and 50.34% in the pressure drop when the magnetic fields of 1200 G, 1500 G and 2000 G are applied when the pitch = 10 mm. These values change to 4.18%, 9.52%, and 16.52% for a pitch = 5 mm and 3.08%, 6.88%, and 14.88% for a pitch = 2.5 mm. Hence, with the increase in the magnetic field, there is a decrease in pressure drop for both the cases and the pitches. This trend is valid only at lower magnetic field strength, because the decrease in the pressure drop dominates over the increase in pressure drop due to turbulence.This work was funded by the Deanship of Scientific Research, Vice Presidency for Graduate Studies and Scientific Research, King Faisal University, Saudi Arabia (Project No. GRANT331). The authors also acknowledge the financial support received for the research project entitled “Performance Improvement of Solar Thermal Systems using Magnetic Nanofluids” funded by the Department of Science and Technology (DST), Govt. of India under India-South Africa Joint Science and Technology Research Collaboration vide Sanction no.: DST/INT/South Africa/P-08/2021 dtd. 16 September 2021

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Modulational Instability and Electromagnetic Wave Scattering of Plasma Flute Modes

The modulation instability of the plasma electromagnetic flute modes has been derived and investigated for two different cases. In the first case, the modulational instability of the flute modes for finite beta plasmas, where the plasma pressure is comparable to that of the external magnetic field one, has been derived. While in the second case, the modulational instability of the flute modes for low beta plasmas, where the plasma dynamics are dominated by the external magnetic field, with the effects of the ion temperature gradient has been derived. It is shown through numerical code, called FLUTE which was developed by Dr. Leboeuf for the NTF, that these flute modes are responsible for the generation of large scale structures in the plasma (the zonal flows), which in turn are responsible for transferring the energy to higher values of the wave vectors through the four wave interaction which has been shown through the modulational instability. In the second part of this dissertation, the scattering of electromagnetic waves by plasma flute vortices has been studied. The scattering cross section has been calculated for the incident S-wave, using MATHEMATICA in order to obtain the angle distribution of scattering cross section and the total scattering cross section numerically. It is found that the scattering cross-section decreases as the incident wave frequency increases and the scattering cross-section increases as the vortex radius increases

Heat Transfer Characteristics of Fractionalized Hydromagnetic Fluid with Chemical Reaction in Permeable Media

This manuscript optimizes the conjugate heat transfer and thermal-stress analysis for hydromagnetic Brinkman fluid with chemical reaction in permeable media. The governing equations of non-Newtonian Brinkman fluid have been traced out and then fractional derivative approach, namely, Caputo–Fabrizio, is invoked, subject to the exponential boundary conditions. The Fourier Sine and Laplace transforms are applied on governing partial differential equations for generating the analytical results of temperature, concentration and velocity. A comparative study of velocity field is investigated for the sake of long memory and hereditary properties. The analytical investigation of temperature, concentration and velocity field have strong effects on chemical reaction. The graphical depiction of vibrant characteristics of hydromagnetic Brinkman fluid with chemical reaction in permeable media is exhibited for disclosing the sensitivities of different embedded rheological parameters of fluid flow. The results suggested that temperature distribution for smaller and larger Prandtl number has disclosed quick and thicker heat diffusivity.This work was supported by the Deanship of Scientific Research, Vice Presidency for Graduate Studies and Scientific Research, King Faisal University, Saudi Arabia [Project No. GRANT233]

Simulation of natural convective heat transfer and entropy generation of nanoparticles around two spheres in horizontal arrangement

Herein, laminar convective heat transfer from two horizontally arranged spheres has been evaluated by using numerical models inside water-based fluids incorporated with alumina (Al2O3), copper oxide (CuO), and copper (Cu) nanoparticles. The problem was simulated for different Rayleigh numbers ranging from 103 to 106 and various volume fractions including 2, 4, 6, and 8%. The evaluation process included the perspective of both first and second thermodynamic laws. In-house FORTRAN code was provided to solve the equations based upon the finite volume method as well as the Multigrid acceleration. According to the obtained results, the average Nusselt number enhanced by 57.4% for both the spheres and plates with increment of the Rayleigh number from 103 to 106 for the constant volume fraction of 2%. In addition, nanoparticle type played a significant role on the heat transfer rate and generated entropy. Moreover, introduction of the Al2O3 nanoparticles into the water-based fluid resulted in approaching to the highest Bejan number of 0.98. Furthermore, the ecological coefficient of performance of CuO nanoparticles decreased by increment of the volume fraction at all Rayleigh numbers. In the volume fraction of 2%, it raised from 2.89 to 7.8 by increasing of the Rayleigh number from 103 to 106

Investigation on inlet obstruction in transitional flow regime: Heat transfer augmentation and pressure drop analysis

Thermohydraulic characteristics of air as the working medium in a circular heated channel fitted with inlet obstruction (ribbed prism) at the inlet is carried out experimentally for transitional flow regime. The ribbed prism is fabricated using aluminum metal. Three non-dimensional parameters clearance ratio (C = 0.4, 0.5 and 0.6) and pitch ratio (e = 0.12, 0.15 and 0.16) were investigated. The Reynolds number (Nu) varied from 500 to 7036 to cover all the flow regimes. Experiments were conducted at two constant heat fluxes of 0.5 kW/m2 and 1 kW/m2. It was found that start and end of transitional flow regime was influenced by insertion of the inlet obstruction at the inlet of the test section. With placement of prism in the channel, the boundaries of transition changes when compared with the plain channel. It is observed that transition starts early and also end early to the transition limit of plain channel. Heat flux shows significant influence on the onset and termination of the transition. At higher heat flux the transition starts later and terminates later when compared with the lower heat flux conditions. For the case of C = 0.6 and e = 0.16, the transition begins Re = 1648 and ends at Re = 3387 for 1 kw/m2 heat flux. The transition of 0.5 kW/m2 of heat flux for C = 0.6 and e = 0.16 begins at Re = 1554 and ends at Re = 3321. Correlations were also developed for predicting the Nusselt number and friction factor and the results are useful to design solar thermal systems and heat exchangers.This work was supported through the Annual Funding track by the Deanship of Scientific Research, Vice Presidency for Graduate Studies and Scientific Research, King Faisal University, Saudi Arabia [Project No. AN00058]

Comprehensive impact analysis of ambient temperature on multi-objective capacitor placements in a radial distribution system

International audienceShunt capacitor banks (SCBs) are used in distribution systems for loss reduction, voltage stability improvement for the system nodes, and system capacity release. However, the size of these capacitors and their placement locations are design factors that have been considered as single or multi-objectives to derive maximum benefits from their installation. To find the optimal location and size of the SCBs, this study proposes the application of multi-objective salp swarm algorithms, considered at ambient temperature, in radial distribution systems. Additionally, a fuzzy-based mechanism has been utilized to identify the best-fit solution of three different objective functions. The proposed method is implemented on IEEE 15-bus and 33-bus radial distribution systems, as well as on real data taken from the Saudi Electricity Company. The results indicate improved effectiveness and higher capability of the proposed method

Look-Ahead Energy Management of a Grid-Connected Residential PV System with Energy Storage under Time-Based Rate Programs

This paper presents look-ahead energy management system for a grid-connected residential photovoltaic (PV) system with battery under critical peak pricing for electricity, enabling effective and proactive participation of consumers in the Smart Grid’s demand response. In the proposed system, the PV is the primary energy source with the battery for storing (or retrieving) excessive (or stored) energy to pursue the lowest possible electricity bill but it is grid-tied to secure electric power delivery. Premise energy management scheme with an accurate yet practical load forecasting capability based on a Kalman filter is designed to increase the predictability in controlling the power flows among these power system components and the controllable electric appliances in the premise. The case studies with various operating scenarios demonstrate the validity of the proposed system and significant cost savings through operating the energy management scheme