Assessment of heat transfer and the consequences of iron oxide (Fe3O4) nanoparticles on flow of blood in an abdominal aortic aneurysm.

The present study is established on a simulation using CFD analysis in COMSOL. Blood acted as the base fluid with this simulation. The taken flow is been modeled as incompressible, unsteady, laminar and Newtonian fluid, which is appropriate at high rates of shear. The characteristic of flow of blood is been studied in order to determine pressure, velocity and temperature impact caused by an abdominal aortic aneurysm (AAA). This work employs nanoparticles of the Iron Oxide (Fe3O4) type. The CFD technique is utilized to evaluate the equations of mass, momentum, and energy. The COMSOL software is utilized to generate a normal element sized mesh. The findings of this study demonstrate that velocity alters through aneurysmal part of the aorta, that velocity is higher in a diseased segment, and that velocity increases before and after the aneurysmal region. For the heat transfer feature, the reference temperature and general inward heat flux is taken as 293.15K and 800W/m2. The nanoparticles altered blood's physical properties, including conductivity, dynamic viscosity, specific heat, and density. The inclusion of Iron Oxide (Fe3O4) nanoparticles managed to prevent overheating because taken nanoparticles have significant thermal conductivity. These findings will be extremely beneficial in the treatment of abdominal aortic aneurysm.

Numerical and Thermal Investigation of Magneto-Hydrodynamic Hybrid Nanoparticles (SWCNT-Ag) under Rosseland Radiation: A Prescribed Wall Temperature Case.

Thermal heat generation and enhancement have been examined extensively over the past two decades, and nanofluid technology has been explored to address this issue. In the present study, we discuss the thermal heat coefficient under the influence of a rotating magneto-hydrodynamic hybrid nanofluid over an axially spinning cone for a prescribed wall temperature (PWT) case. The governing equations of the formulated problem are derived by utilizing the Rivlin-Ericksen tensor and boundary layer approximation (BLA). We introduce our suppositions to transform the highly non-linear partial differential equations into ordinary differential equations. The numerical outcomes of the problem are drafted in MATLAB with the of help the boundary value problem algorithm. The influences of several study parameters are obtained to demonstrate and analyze the magneto-hydrodynamic flow characteristics. The heat and mass transfer coefficients increase and high Nusselt and Sherwood numbers are obtained with reduced skin coefficients for the analyzed composite nanoparticles. The analyzed hybrid nanofluid (SWCNT-Ag-kerosene oil) produces reduced drag and lift coefficients and high thermal heat rates when compared with a recent study for SWCNT-MWCNT-kerosene oil hybrid nanofluid. Maximum Nusselt (Nu) and Sherwood (Sh) numbers are observed under a high rotational flow ratio and pressure gradient. Based on the results of this study, we recommend more frequent use of the examined hybrid nanofluid.

OxVent: Design and evaluation of a rapidly-manufactured Covid-19 ventilator.

BACKGROUND: The manufacturing of any standard mechanical ventilator cannot rapidly be upscaled to several thousand units per week, largely due to supply chain limitations. The aim of this study was to design, verify and perform a pre-clinical evaluation of a mechanical ventilator based on components not required for standard ventilators, and that met the specifications provided by the Medicines and Healthcare Products Regulatory Agency (MHRA) for rapidly-manufactured ventilator systems (RMVS). METHODS: The design utilises closed-loop negative feedback control, with real-time monitoring and alarms. Using a standard test lung, we determined the difference between delivered and target tidal volume (VT) at respiratory rates between 20 and 29 breaths per minute, and the ventilator's ability to deliver consistent VT during continuous operation for >14 days (RMVS specification). Additionally, four anaesthetised domestic pigs (3 male-1 female) were studied before and after lung injury to provide evidence of the ventilator's functionality, and ability to support spontaneous breathing. FINDINGS: Continuous operation lasted 23 days, when the greatest difference between delivered and target VT was 10% at inspiratory flow rates >825 mL/s. In the pre-clinical evaluation, the VT difference was -1 (-90 to 88) mL [mean (LoA)], and positive end-expiratory pressure (PEEP) difference was -2 (-8 to 4) cmH2O. VT delivery being triggered by pressures below PEEP demonstrated spontaneous ventilation support. INTERPRETATION: The mechanical ventilator presented meets the MHRA therapy standards for RMVS and, being based on largely available components, can be manufactured at scale. FUNDING: Work supported by Wellcome/EPSRC Centre for Medical Engineering,King's Together Fund and Oxford University.

Effect of time dependent viscosity and radiation efficacy on a non-Newtonian fluid flow.

In the present article we have studied the radiation effects on the flow of a viscoelastic fluid flow past a spongy plate by considering the viscosity as variable. In order to explore the variable viscosity effects, law of conservation of mass, momentum and energy are flourished. The shooting method is adapted to accomplish the numerical solution of governing equations. The effects of the involved emerging parameters such as Reynolds' model viscosity numbers, Vogel's model viscosity numbers and Prandtl numbers on velocity and temperature profiles are discussed with the help of graphs. The associated physical properties of the flow i.e. the skin friction coefficient and Nusselt numbers are presented graphically for different parameters. The tables for effects of distinct parameters on temperature profile at the wall for Reynolds' model and Vogel's model are given. Impact of various parameters involved on Nusselt number and skin friction are also presented in tables.