Universality of temperature distribution in granular gas mixtures with a steep particle size distribution

Distribution of granular temperatures in granular gas mixtures is investigated analytically and numerically. We analyze space uniform systems in a homogeneous cooling state (HCS) and under a uniform heating with a mass-dependent heating rate $\Gamma_k\sim m_k^{\gamma}$. We demonstrate that for steep size distributions of particles the granular temperatures obey a universal power-law distribution, $T_k \sim m_k^{\alpha}$, where the exponent $\alpha$ does not depend on a particular form of the size distribution, the number of species and inelasticity of the grains. Moreover, $\alpha$ is a universal constant for a HCS and depends piecewise linearly on $\gamma$ for heated gases. The predictions of our scaling theory agree well with the numerical results

Intermediate regimes in granular Brownian motion: Superdiffusion and subdiffusion

Brownian motion in a granular gas in a homogeneous cooling state is studied theoretically and by means of molecular dynamics. We use the simplest first-principle model for the impact-velocity dependent restitution coefficient, as it follows for the model of viscoelastic spheres. We reveal that for a wide range of initial conditions the ratio of granular temperatures of Brownian and bath particles demonstrates complicated non-monotonous behavior, which results in transition between different regimes of Brownian dynamics: It starts from the ballistic motion, switches later to superballistic one and turns at still later times into subdiffusion; eventually normal diffusion is achieved. Our theory agrees very well with the MD results, although extreme computational costs prevented to detect the final diffusion regime. Qualitatively, the reported intermediate diffusion regimes are generic for granular gases with any realistic dependence of the restitution coefficient on the impact velocity

Ali je lahko ženska Kolumb? Nekateri vidiki preučevanja potopisov Alme Karlin

Prispevek se ukvarja z nekaterimi možnimi vidiki preučevanja potopisov Alme Karlin, ki imajo pomembno vlogo v njenem ustvarjanju. Analiziramo žanrske posebnosti njenih potopisov, njihovo literarno topiko in avtobiografskost. Posebna pozornost je posvečena tako ciljem potovanja A. Karlin kot namenu njenih potopisov. Osnovni poudarek je na specifiki ženskega potovanja in fenomenu meje, ki ga problematizirajo ne samo dela A. Karlin, ampak tudi njihova recepcija. Analiziran je motiv groze, ki je deloma povezan s trivialno literaturo, obravnavana pa je tudi ženska verzija arhetipa junaka odkritelja, ki je predstavljena v potopisih A. Karlin. The paper deals with some disputable aspects of Alma Karlin’s travelogues, which play an important role in her work. The genre characteristics of her travelogues, their literary topics and the autobiographical nature are considered. Particular attention is paid to both the goals of Alma Karlin’s journey and intentions of her travelogues. The basic focus is on the specifics of women’s travel and the phenomenon of the border, which is problematised not only by Karlin’s works, but also by their reception. The motif of horror, which is partly relevant to trivial literature, is also examined, and the female version of the archetype of the hero as discoverer, as is presented in the works of A. Karlin, is discussed