Computation of swirling hydromagnetic nanofluid flow containing gyrotactic microorganisms from a spinning disk to a porous medium with hall current and anisotropic slip effects.

Prompted by the advancements in hybrid bio-nano-swirling magnetic bioreactors, a mathematical model for the swirling flow from a rotating disk bioreactor to a magnetic fluid saturating a porous matrix and containing nanoparticles and gyrotactic micro-organisms has been developed. An axial magnetic field is administered which is perpendicular to the disk and Hall currents are included. The disk is assumed to be impervious and stretches in the radial direction with a power-law velocity. The Buongiorno nanoscale, Kuznetsov bioconvection and Darcy porous media models are deployed. Anisotropic momentum, thermal, nanoparticle concentration and motile micro-organism slip effects are incorporated. Stefan blowing is also simulated. The governing conservation equations are transformed with appropriate variables to ordinary nonlinear differential equations. MATLAB bvp4c shooting quadrature is used to solve the emerging nonlinear, coupled ordinary differential boundary value problem under transformed boundary conditions. Verification with earlier solutions for the non-magnetic Von Karman bioconvection nanofluid case is conducted. Further validation of the general magnetic model is conducted with the Adomian decomposition method (ADM). Extensive visualization of velocity, temperature, nanoparticle concentration and motile microorganism density number profiles is presented for the impact of various parameters including magnetic interaction parameter, Hall current parameter, Darcy number, momentum slip, thermal slip, nanoparticle slip and microorganism slip. Computations are also performed for skin friction, Nusselt number, Sherwood number and motile micro-organism density number gradient. The simulations provide a useful benchmark for further studies

Role of Coronary CT Angiography in the Evaluation of Acute Chest Pain and Suspected or Confirmed Acute Coronary Syndrome

Advances in CT technology have resulted in improved imaging of the coronary anatomy in patients with stable coronary artery disease, using coronary CT angiography (CCTA). Recent data suggest that CCTA may play a role in higher risk patients, such as those evaluated in the emergency room with acute chest pain. Data thus far support the use of CCTA in low-risk patients with acute chest pain. Recent literature suggests that CCTA may play a role in the risk stratification of selected intermediate-risk patients. In this review, the authors discuss the emerging role of CCTA in higher risk patients, such as those with suspected or confirmed acute coronary syndrome (ACS). The excellent accuracy of CCTA in detecting obstructive coronary artery disease in patients with ACS is detailed, along with a highlighting of the safety of using CCTA in this setting. The authors also discuss the role for CCTA atheromatous plaque characterization, which is being increasingly recognized as an important predictor of clinical outcomes

Partial Differential Equations in Applied Mathematics https://www.sciencedirect.com/journal/partial-differential-equations-in-applied- mathematics Analysis of unsteady thermo-solutal MoS2-EO Brinkman electro-conductive reactive nanofluid transport in a hybrid rotating Hall MHD generator

MHD rotating generators offer a plausible renewable energy mechanism. New designs are emerging in which nanotechnology is contributing. Such systems are increasingly deploying more complex functional fluid materials such as base fluids containing magnetic nanoparticles which constitute electromagnetic nanofluids and can be tuned to enhance efficiencies. Motivated by these developments, a mathematical model is presented for the combined effects of Hall current, heat source, chemical reaction and radiative flux on the unsteady rotating thermo-solutal magnetohydrodynamic transport of a Molybdenum disulphide (MoS2)-EO oil electroconductive Brinkman nanofluid to study the boundary layer characteristics in the vicinity of the side wall of an MHD generator system. The governing dimensional conservation equations are scaled using appropriate transformations into a system of dimensionless coupled partial differential equations. Under appropriate initial and boundary conditions, solutions are derived using the Laplace Transform Method (LTM) and complex variables. The physical impacts of the magnetic, nanoscale, thermal and species control parameters on primary and secondary velocity, temperature and concentration are visualized graphically. The judicious doping of the base fluid with MoS2 nanoparticles is shown to achieve superior thermal performance for MHD rotating energy generators

Finite element stress analysis and topological optimization of a commercial aircraft seat structure

In recent years, the Finite Element Method (FEM) has emerged as a cornerstone in the field of seating design, particularly within the aircraft industry. Over the past decade, significant advancements in Finite Element (FE) analysis techniques have revolutionized the seat industry, enabling the creation of safer and more cost-effective seat designs. The accuracy of FE analysis plays a pivotal role in this transformation. In the process of constructing a reliable finite element model, the selection and precise manipulation of key parameters are paramount. These crucial parameters encompass element size, time scale, analysis type, and material model. Properly defining and implementing these parameters ensures that the FE model produces accurate results, closely mirroring real-world performance. Verification of Finite Element Analysis (FEA) results is commonly accomplished through experimental methods. Notably, when the parameters are appropriately integrated into the modelling process, FE analysis outcomes closely align with experimental results. This study aims to leverage the power of FEM in performing static stress analysis and topology optimization of aircraft seats using the SOLIDWORKS commercial finite element platform. By simulating loading conditions, this research calculates static stresses and displacements experienced by the aircraft seat. For AL7075-T6(SN) the structural analysis demonstrates that this material had a maximum stress of 125.2 N/mm 2 and a minimum stress of 0.0039 N/mm 2. Due to its strong 4.034 factor of safety, the component may have been over-engineered for its intended use. However, at 2.32 kg, the component's mass and $2.304/kg material cost showed a high design cost. The maximum Y-component of displacement was 0.0606 mm, which was acceptable but could have been optimized to decrease material use and expense without affecting structural integrity. After performing topology optimization on Simulation 1 of AL7075-T6(SN), several improvements have been achieved. The maximum stress sustained by the component has been elevated to 189.4 N/mm 2. However, it is worth noting that the minimum stress has also risen, although to a negligible value of 0.0006 N/mm 2. The compromise in this scenario is characterized by a fall in the factor of safety to 2.666, suggesting a design that is more optimal but possibly associated with more risk. The most notable improvements, however, concern weight reduction. The overall mass of the component saw a substantial reduction, reaching 1.89 kg, which represents a notable improvement on the original design. Through a comprehensive topology optimization study, the weight of the airplane seat is remarkably reduced by up to 30%, while still prioritizing passenger safety. The success of this optimization showcases the potential for substantial weight savings in aircraft seat design without compromising safety standards

Ethno-medicinal Survey for Some Wild Plants of Muzaffarabad, Azad Jammu & Kashmir, Pakistan

Wild plants have always held economic, nutritional and medicinal value for human beings. Present work is the study of local information of some wild plants being used for remedial purposes in District Muzaffarabad, Azad Jammu and Kashmir, Pakistan. The indigenous knowledge of local conventional uses was collected through survey and personal interviews during field trips. A total of 50 plant species were identified by taxonomic description using field guides and locally by medicinal knowledge of people living in the area. About 150 informers were interviewed randomly to record local names and ethno-medicinal uses of different plant species

Numerical study of chemically reactive buoyancy-driven heat and mass transfer across a horizontal cylinder in a high-porosity non-Darcian regime

We investigate the free convection boundary layer flow and heat and mass transfer across an isothermal cylinder embedded in an isotropic, homogenous, saturated porous regime with a first-order chemical reaction in the diffusing species. A Darcy-Forchheimer drag force model is implemented to simulate porous impedance effects in high-porosity media, which are encountered in various industrial and geophysical applications. The partial differential conservation equations are nondimensionalized and solved using a network simulation methodology. The effects of Darcy number, Forchheimer number, Schmidt number, and reaction parameter on dimensionless velocity, temperature, and species concentration distributions are studied in detail for the case of water of relevance to geohydraulic flows. Computations are also provided for the variation of local Nusselt number and local Sherwood number with various thermophysical parameters. Concentration is found to decrease continuously with distance into the boundary layer (y-coordinate) with an increase in chemical reaction parameter; values are markedly higher for the non-Darcian case than for the Darcian case. Temperatures are however increased by an increase in reaction parameter. Applications of the study include electrolysis processes, chemical filtration treatment systems, natural convection from buried waste canisters in geomaterials, geothermal systems, etc

Network numerical simulation of impulsively-started transient radiation-convection heat and mass transfer in a saturated Darcy-Forchheimer porous medium

We study the effects of thermal radiation and porous drag forces on the natural convection heat and mass transfer of a viscous, incompressible, gray, absorbingemmitting fluid flowing past an impulsively started moving vertical plate adjacent to a non-Darcian porous regime. The governing boundary-layer equations are formulated in an (X , Y , t ) coordinate system with appropriate boundary conditions. The Rosseland diffusion approximation is employed to analyze the radiative heat flux and is appropriate for non-scattering media. The model is non-dimensionalized and solved with the network simulation model. We study the influence of Prandtl number, radiation-conduction parameter, thermal Grashof number, species Grashof number, Schmidt number, Darcy number and Forchheimer number on the dimensionless velocity, temperature and species function distributions. Additionally we compute the variation of the local skin friction, Nusselt number and Sherwood number for selected thermophysical parameters. Increasing Darcy number is seen to accelerate the flow; the converse is apparent for an increase in Forchheimer number. Thermal radiation is seen to reduce both velocity and temperature in the boundary layer. The interactive effects of second order porous drag and thermal radiation are also considered. The model finds applications in solar energy collection systems, porous combustors, transport in fires in porous media (forest fires) and also the design of high temperature chemical process systems

Cross diffusion and higher order chemical reaction effects on hydromagnetic copper-water nanofluid flow over a rotating cone with porous medium

Spin coating of engineering components with advanced functional nanomaterials which respond to magnetic fields is growing. Motivated by exploring the fluid dynamics of such processes, a mathematical model is developed for chemically reactive Cu−H2O magnetohydrodynamic (MHD) nanofluid swirl coating flow on a revolving vertical electrically insulated cone adjacent to a porous medium under a radial static magnetic field. Heat and mass transfer is included and Dufour and Soret cross diffusion effects are also incorporated in the model. Thermal and solutal buoyancy forces are additionally included. The Tiwari-Das nanoscale model has been used. To simulate chemical reaction of the diffusing species encountered in manufacturing processes, a higher order chemical reaction formulation is also featured. Via suitable scaling transformations, the governing nonlinear coupled partial differential conservation equations and associated boundary conditions are reformulated as a nonlinear ordinary differential boundary value problem. MATLAB-based shooting quadrature with a Runge-Kutta method is deployed to solve the emerging system. Concentration, temperature, velocity variations for various non-dimensional flow parameters have been visualized and analysed. In addition, key wall characteristics i. e. radial and circumferential skin friction, Nusselt number, Sherwood number have also been computed. Validation with earlier studies is also included. The simulations indicate that when compared to a lower order chemical reaction, a higher order chemical reaction allows a greater rate of heat and mass transfer at the cone surface. Increasing Dufour (diffuso-thermal) and Soret number generally reduce radial and circumferential skin friction and also Nusselt number whereas they elevate Sherwood number. Both skin friction components are also suppressed with increasing Richardson number. Strong deceleration in the tangential and circumferential velocity components is induced with greater magnetic field

Mathematical and numerical modeling of non-Newtonian thermo-hydrodynamic flow in non-Darcy porous media

We analyse the steady convection boundary layer flow of a second order non-Newtonian fluid near a wedge structure embedded in a Darcy−Brinkman porous medium. The governing equations are formulated using a boundary layer theory, then transformed into pseudo-similarity equations and these equations are subsequently solved using the powerful Nakamura finite difference method. Solutions are produced for surface shear stress and local heat transfer at the wedge face. The effects of viscoelasticity coefficient, K, Reynolds number, Re, Prandtl number, Pr, and Darcy number, Da, are presented graphically and discussed

Non-isothermal hydromagnetic convection in a porous medium with heat sink: hypergeometric function solutions

The present paper deals with the free convection laminar boundary layer flow and heat transfer of an incompressible, electrically conducting, viscous fluid through a porous medium caused by stretching a porous wall in the presence of a heat source and under the influence of uniform magnetic field. Exact solutions of the basic equations of momentu m and energy ar e obtained after reducing them i n to non-linear ordinary differential equations and using confluent hypergeometric functions. The variations in the velocity field and temperature distribution with the Prandtl number (Pr), hydromagnetic parameter (M), permeability param eter (K), suction parameter (N), wall temperature parameler (S), and the heat sink parameter (Q) are obtained and depicted graphically. The skin-friction at the wall is also derived, and the numerical values for various physical parameters are also tabulaled. Magnetic field (M) is seen to reduce both longitudinal and translational velocities and also lower temperalures, aiding in controlling momentum and heat transfer during materiaIs processing. Suction (N) posivitely influences the transverse velocity but depresses the longitudinal velocity magnitudes as we II as decreasing tempcratures. Suction therefore also assists in controlling heat transfer in Ihe boundary layer. Increasing permeability parameter (K) depresses the longitudinal velocity but elevates transverse velocities and increases the skin friction at the wall. Both rising temperature (non-isothermal wall) parameter (S) and heat sink parameter (Q) decrease temperature values. The model finds applications in nucIear engineering control systems and MHD energy systems