Enhanced entropy generation and heat transfer characteristics of magnetic nano-encapsulated phase change materials in latent heat thermal energy storage systems

The objective of the current study is to investigate the importance of entropy generation and thermal radiation on the patterns of velocity,isentropic lines,and temperature contours within a thermal energy storage device filled with magnetic nanoencapsulated phase change materials(NEPCMs).The versatile finite element method(FEM)is implemented to numerically solve the governing equations.The effects of various parameters,including the viscosity parameter,ranging from 1 to 3,the thermal conductivity parameter,ranging from 1 to 3,the Rayleigh parameter,ranging from 102 to 3×10^(2),the radiation number,ranging from 0.1 to 0.5,the fusion temperature,ranging from 1.0 to 1.2,the volume fraction of NEPCMs,ranging from 2%to 6%,the Stefan number,ranging from 1 to 5,the magnetic number,ranging from 0.1 to 0.5,and the irreversibility parameter,ranging from 0.1 to 0.5,are examined in detail on the temperature contours,isentropic lines,heat capacity ratio,and velocity fields.Furthermore,the heat transfer rates at both the cold and hot walls are analyzed,and the findings are presented graphically.The results indicate that the time taken by the NEPCMs to transition from solid to liquid is prolonged inside the chamber region as the fusion temperatureθf increases.Additionally,the contours of the heat capacity ratio Cr decrease with the increase in the Stefan number Ste.

Effect of Nickel on Some Aspects of Protein Metabolism in Selected Organs of the Freshwater Mussel Lamellidens marginalis

The levels of soluble, structural and total proteins, and the activities of AlAT and AAT decreased along with an increase in the levels of free amino acids and the activity of protease in the ctenidium, hepatopancreas and foot of the freshwater mussel L. marginalis after 1,2,3 and 4 d of exposure to a lethal concentration (115 mg.L-1) of nickel. But the activity of GDH and the level of urea decreased in the hepatopancreas and increased in the ctenidium and foot. A reverse trend was observed in the level of ammonia. In a sublethal concentration (23 mg.L-1), the levels of soluble, structural and total proteins and ammonia decreased in these three organs of the mussel after 1, 5, 10 and 15 d of exposures, with an increase in the levels.of free aminoacids, urea and in the activities of protease, Al AT, AAT and ODH. The extent of these changes differed in degree depending on exposure period in the lethal and sublethal concentrations. The results are discussed in order to arrive at the degree of metal stress on the overall nitrogen metabolism of the mussel according to the period of exposure to lethal and sublethal concentrations of nickel.

Magnetohydrodynamic(MHD)boundary layer heat and mass transfer characteristics of nanofluid over a vertical cone under convective boundary condition

This paper investigates the boundary layer flow,heat and mass transfercharacteristics over a vertical cone filled with nanofluid saturated porous medium with theinfluence of magnetic field,thermal radiation and first order chemical reaction subject to theconvective boundary condition.Similarity transformation technique is used for the purpose ofconverting non-linear partial differential equations into the system of complex ordinarydifferential equations.The computational Finite element method has been employed to solvethe flow,heat and mass transfer equations together with boundary conditions.The impact ofvarious pertinent parameters on hydrodynamic,thermal and solutal boundary layers isinvestigated and the results are displayed graphically.Furthermore,the values of local skin-friction coefficient,rate of temperature and rate of concentration is also calculated and theresults are presented graphically.The comparisons with previously published work is made andfound good agreement.The thickness of thermal boundary layer is increased with increase inthe values of Brownian motion parameter(Nb)and thermophoresis parameter(Ni).