Study of non-equilibrium effects and thermal properties of heavy ion collisions using a covariant approach

Non-equilibrium effects are studied using a full Lorentz-invariant formalism. Our analysis shows that in reactions considered here, no global or local equilibrium is reached. The heavier masses are found to be equilibrated more than the lighter systems. The local temperature is extracted using hot Thomas Fermi formalism generalized for the case of two interpenetrating pieces of nuclear matter. The temperature is found to vary linearly with bombarding energy and impact parameter whereas it is nearly independent of the mass of the colliding nuclei. This indicates that the study of temperature with medium size nuclei is also reliable. The maximum temperatures obtained in our approach are in a nice agreement with earlier calculations of other approaches. A simple parametrization of maximal temperature as a function of the bombarding energy is also given.Comment: LaTex-file, 17 pages, 8 figures (available upon request), Journal of Physics G20 (1994) 181

Nuclear Dynamics at the Balance Energy

We study the mass dependence of various quantities (like the average and maximum density, collision rate, participant-spectator matter, temperature as well as time zones for higher density) by simulating the reactions at the energy of vanishing flow. This study is carried out within the framework of Quantum Molecular Dynamics model. Our findings clearly indicate an existence of a power law in all the above quantities calculated at the balance energy. The only significant mass dependence was obtained for the temperature reached in the central sphere. All other quantities are rather either insensitive or depend weakly on the system size at balance energy. The time zone for higher density as well as the time of maximal density and collision rate follow a power law inverse to the energy of vanishing flow.Comment: 9 figures, Submitted to Phys. Rev.

Dormancy and Revitalization: The fate of ethnobotanical knowledge of camel forage among Sahrawi nomads and refugees of Western Sahara

Knowledge about forage is fundamental to the survival of pastoral populations around the world. In this paper, we address the knowledge of camel forage of Sahrawi nomads and refugees of Western Sahara. We analyze the distribution of this knowledge through cultural consensus analysis and develop an explanation for intra-cultural variation based on changing processes of knowledge transmission. In total, 100 plant species were free-listed by informants, with five species (i.e., Acacia tortilis (Forssk.) Hayne, Nucularia perrinii Batt., Astragalus vogelii (Webb) Bornm., Panicum turgidum Forssk., and Stipagrostis plumosa Munro ex T.Anderson) found to be culturally highly salient. These five represent five local categories of forage that are necessary for camel management in the Western Sahara desert. The Sahrawi listed 25 forage plants that influence the taste and properties of camel milk, demonstrating that cultural values, as much as survival functions, underpin local knowledge systems. Perhaps unsurprisingly, age and nomadic experience are positively correlated with forage knowledge. Forced displacement and sedentarization are hypothesized as causes of progressive non-use of this knowledge and the lack of its transmission to younger generations of refugees. Nonetheless, across the study area, refugees are re-engaging with pastoralism and nomadism, which is leading to a revitalization of forage knowledge and its transmission. This should be regarded as an adaptation pathway for refugees