18 research outputs found

    ADM solution for Cu/CuO –water viscoplastic nanofluid transient slip flow from a porous stretching sheet with entropy generation, convective wall temperature and radiative effects

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    A mathematical modelis presented for entropy generation in transient hydromagnetic flow of an electroconductive magnetic Casson (non-Newtonian) nanofluid over a porous stretching sheet in a permeable medium. The Cattaneo-Christov heat flux model is employed to simulate non-Fourier (thermal relaxation) effects. A Rosseland flux model is implemented to model radiative heat transfer. The Darcy model is employed for the porous media bulk drag effect. Momentum slip is also included to simulate non-adherence of the nanofluid at the wall. The transformed, dimensionless governing equations and boundary conditions (featuring velocity slip and convective temperature) characterizing the flow are solved with the Adomian Decomposition Method (ADM). Bejan’s entropy minimization generation method is employed. Cu-water and CuO-water nanofluids are considered. Extensive visualization of velocity, temperature and entropy generation number profiles is presented for variation in magnetic field parameter, unsteadiness parameter, Casson parameter, nanofluid volume fraction, permeability parameter, suction/injection parameter, radiative parameter, Biot number, relaxation time parameter, velocity slip parameter, Brinkman number (dissipation parameter), temperature ratio and Prandtl number. The evolution of skin friction and local Nusselt number (wall heat transfer rate) are also studied. The ADM computations are validated with simpler models from the literature. The solutions show that with elevation in volume fraction of nanoparticle and Brinkman number, the entropy generation magnitudes are increased. An increase in Darcy number also increases the skin friction and local Nusselt number. Increasing magnetic field, volume fraction, unsteadiness, thermal radiation, velocity slip, Casson parameters, Darcy and Biot numbers are all observed to boost temperatures. However, temperatures are reduced with increasing non-Fourier (thermal relaxation) parameter. Greater flow acceleration is achieved for CuO-water nanofluid compared with Cu-water nanofluid although the contrary response is computed in temperature distributions. The simulations are relevant to the high temperature manufacturing fluid dynamics of magnetic nanoliquids, smart coating systems etc

    The use of genetic correlations to evaluate associations between SNP markers and quantitative traits

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    Open-pollinated progeny of Corymbia citriodora established in replicated field trials were assessed for stem diameter, wood density, and pulp yield prior to genotyping single nucleotide polymorphisms (SNP) and testing the significance of associations between markers and assessment traits. Multiple individuals within each family were genotyped and phenotyped, which facilitated a comparison of standard association testing methods and an alternative method developed to relate markers to additive genetic effects. Narrow-sense heritability estimates indicated there was significant additive genetic variance within this population for assessment traits (Ä¥=0.28 to 0.44) and genetic correlations between the three traits were negligible to moderate (r = 0.08 to 0.50). The significance of association tests (p values) were compared for four different analyses based on two different approaches: (1) two software packages were used to fit standard univariate mixed models that include SNP-fixed effects, (2) bivariate and multivariate mixed models including each SNP as an additional selection trait were used. Within either the univariate or multivariate approach, correlations between the tests of significance approached +1; however, correspondence between the two approaches was less strong, although between-approach correlations remained significantly positive. Similar SNP markers would be selected using multivariate analyses and standard marker-trait association methods, where the former facilitates integration into the existing genetic analysis systems of applied breeding programs and may be used with either single markers or indices of markers created with genomic selection processes
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