Models lithium abundance

Fig. 2. (Left panel) evolutionary tracks using FST in the logTefj vs. log g plane (solid line non gray models with rph = 10 by Montalban et al.,2004) and 2D calibrated MLT (dashed line).(Right panel) Lithium evolution for the solar mass with different assumptions about convection and model atmospheres. The dotted line at bottom represents today s solar lithium abundance. MLT models with AH97 model atmospheres down to Tph = 10 and 100 are shown dotted for cum = 1 and dash-dotted for cpr, = 1.9. The Montalban et al. (2004) MLT models with Heiter et al. (2002) atmospheres down to Tph = 10 (lower) and 100 (upper) are dashed The continuous lines show the non gray FST models for rph = 10 and 100, and, in between, the long dashed model employing the 2D calibrated MLT.

Fig. 4.12. Stellar lithium abundances (log of the number per 1012 H atoms) among main-sequence stars as a function of metallicity. The full-drawn curve shows the prediction of a numerical Galactic chemical evolution model, while the broken-line curve gives the sum of a primordial component and an additional component proportional to iron and normalized to meteoritic abundance. Adapted from Matteucci, D Antona and Timmes (1995).

What is the level of the Spite Plateau lithium abundance Which observations can pin down the systematic corrections due to model stellar atmospheres and temperature scales and which may reveal evidence for, and quantify, early-Galaxy production as well as stellar depletion/destruction ... 

Figure 8. Contributions to the total predicted lithium abundance from the adopted GCE model of [60], compared with low metallicity stars and a sample of high metallicity stars. The solid curve is the sum of all components.

The abundance of lithium in stellar atmospheres presents an important observational constraint to the hydrodynamical models of the outer layers of stars. It can be considered as a cumulative measure of the extent of matter exchange between surface and deeper layers during the stellar evolution. 

The agreement between the predictions of the SBBN model for the abundances of deuterium, helium-4, helium-3 and lithium-7 and the observations of the primordial abundances of these light elements is one of the successes and therefore one of the cornerstones of the Big Bang Cosmology. 

Figure 1.2. A/H for deuterium, helium-3, lithium-7 and Yp versus fif, - the four curves show the predicted abundances by the sBBN model, - the horizontal boxes show the various measurements, - the vertical band covers the D/H data. From Kirkman et al. 2003...

Figure 8 shows the different Li components for a model with ( Li/H)p = 1.23 X 10 . The linear slope produced by the model is independent of the input primordial value. The model of reference [60] includes in addition to primordial Li, lithium produced in Galactic cosmic-ray nucleosynthesis (primarily a + a fusion), and Li produced by the v-process during core collapse supemovae. As one can see, these processes are not sufficient to reproduce the population I abundance of Li, and additional production sources are needed. 

Figure 8 also shows the evolution of the Li abundance in a standard model of galactic chemical evolution. In the case of Li, new data [77, 78, 79, 80, 81, 82] lie a factor - 1000 above the BBN predictions [83], and fail to exhibit the dependence on metallicity expected in models based on nucleosynthesis by Galactic cosmic rays [84, 85, 86]. On the other hand, the Li abundance may be explained by pre-Galactic Population-Ill stars, without additional overproduction of Li [87, 88]. Some exotic solutions to both lithium problems involving particle decays in the early universe have been proposed [89, 90, 91, 92, 93,94, 95,96,97,98], but that goes beyond the scope of this review. 

Because in the west of China some salt lake brines contain abundant boron and lithium, in which solute-solvent and solute-solute interactions are complex, studies on the ihermochemical properties for the systems related with the brines are essential to understand the effects of temperature on excess free energies and solubility, and to build a thermodynamic model that can be applied for prediction of the properties. Yin et al. [43] measured the enthalpies of dilution for aqueous Li2B407 solutions from 0.0212 to 2.1530 mol/kg at 298.15 K. The relative apparent molar enthalpies and relative partial molar enthalpies of the solvent and solute were also calculated, and the thermodynamic properties of the complex aqueous solutions were represented by a modified Pitzer ion-interaction model. 

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