Solid solution decomposition and Guinier-Preston zone formation in Al-Cu alloys: A kinetic theory with anisotropic interactions

Using methods of statistical kinetic theory parametrized with first-principles interatomic interactions that include chemical and strain contributions, we investigated the kinetics of decomposition and microstructure formation in Al-Cu alloys as a function of temperature and alloy concentration. We show that the decomposition of the solid solution forming platelets of copper, known as Guinier-Preston (GP) zones, includes several stages and that the transition from GP1 to GP2 zones is determined mainly by kinetic factors. With increasing temperature, the model predicts a gradual transition from platelet-like precipitates to equiaxial ones and at intermediate temperatures both precipitate morphologies may coexist.Comment: 9 pages, 8 figure

Echolocation peak frequency is an honest signal in <i>Rhinolophus mehelyi</i>.

<p>Correlation between peak frequency and body condition for (A), males and, (B), females captured during the mating season.</p

Experimental set-up for the mate choice experiment.

<p>Examples of spectrograms of low and high frequency echolocation calls played back are presented at the bottom of the figure.</p

Behavioural experiments of mate choice preference in <i>Rhinolophus mehelyi.</i>

<p>(A) Depicts that females (top, n = 61) made a choice more often compared to males (bottom, n = 15) when confronted with adult male calls with high or low frequency. (B) Indicates that when a bat reacted to the test, females (left, n = 49) preferred high frequency calls while males (right, n = 7) did not show any preference (see text for statistical results). For each boxplot, the box represents the 25^th quantile, median (thick black bar) and 75^th quantile. To showcase possible outliers, whiskers were shortened to a length of 0.1 times the interquartile range.</p

Correlation between an individual’s peak frequency and average relatedness with other members of the colony.

<p>Data are presented for (A), females (<i>n</i> = 29) and (B), males (<i>n</i> = 28) of El Haouariya colony (see text for statistical results). The solid back line represents a linear regression between peak frequency and relatedness and the dashed lines the 95% confidence interval of this regression.</p

Relationships between peak frequency and size, body weight and body condition for male and female <i>Rhinolophus mehelyi</i> captured in September, during the mating season.

<p>Relationships between peak frequency and size, body weight and body condition for male and female <i>Rhinolophus mehelyi</i> captured in September, during the mating season.</p