Electromagnetic wave characteristics of a fully ionized gas Final report

Electromagnetic wave propagation in fully ionized ga

Buoyancy-driven plumes in a layered porous medium

</jats:p

Stability of three-dimensional columnar convection in a porous medium

The stability of steady convective exchange flow with a rectangular planform in an unbounded three-dimensional porous medium is explored. The base flow comprises a balance between vertical advection with amplitude $A$ in interleaving rectangular columns with aspect ratio \unicode[STIX]{x1D709}\leqslant 1 and horizontal diffusion between the columns. Columnar flow with a square planform (\unicode[STIX]{x1D709}=1) is found to be weakly unstable to a large-scale perturbation of the background temperature gradient, irrespective of $A$, but to have no stronger instability on the scale of the columns. This result provides a stark contrast to two-dimensional columnar flow (Hewitt et al., J. Fluid Mech., vol. 737, 2013, pp. 205–231), which, as $A$ is increased, is increasingly unstable to a perturbation on the scale of the columnar wavelength. For rectangular planforms with \unicode[STIX]{x1D709}<1, a critical aspect ratio is identified, below which a perturbation on the scale of the columns is the fastest growing mode, as in two dimensions. Scalings for the growth rate and the structure of this mode are identified, and are explained by means of an asymptotic expansion in the limit \unicode[STIX]{x1D709}\rightarrow 0. The difference between the stabilities of two-dimensional and three-dimensional exchange flow provides a potential explanation for the apparent difference in dominant horizontal scale observed in direct numerical simulations of two-dimensional and three-dimensional statistically steady ‘Rayleigh–Darcy’ convection at high Rayleigh numbers.</jats:p

Bubble Dynamics in Liquid Nitrogen

Mechanical Engineerin

Effects of Two Commercial Game Bird Feeds on Captive Northern Bobwhite Chick Growth Rates

Supplemental feeding of northern bobwhites (Colinus virginianus) is a widespread management practice. Bobwhite chicks in the wild consume only arthropods for their first 30–60 days of life. Arthropods may become less abundant and managers have supplied bobwhites with supplemental feed during times of drought to mitigate the lack of arthropods. We compared growth rates of captive bobwhite chicks consuming a new, commercial 24% crude protein supplement to growth rates of bobwhites consuming a commercial 30% crude protein complete ration. There was no male/female bias related to chick growth. Chicks consuming the 24% protein diet grew slower and reached adult mass (150 g) 1 month later than birds on the 30% protein diet. Birds grew 4–6 times faster than documented rates from wild chicks in Florida, but this is attributed to captivity bias. A 24% protein supplement has insufficient protein to optimize growth of bobwhites and is a poor substitute for arthropods in time of drought. A 30% protein diet has sufficient nutrient levels to justify further research as a supplement to mitigate a lack of arthropods in times of drought