Simulations of composite carbon films with nanotube inclusions

We study the interfacial structure, stability, and elastic properties of composite carbon films containing nanotubes. Our Monte Carlo simulations show that Van der Waals forces play a vital role in shaping up the interfacial geometry, producing a curved graphitic wall surrounding the tubes. The most stable structures are predicted to have intermediate densities, high anisotropies, and increased elastic moduli compared to pure amorphous carbon films.Comment: 3 pages, 3 figures, to appear in Appl. Phys. Let

Dramatic Heterotopias and Transformations of Mythic Space: H.D.’s Helen in Egypt and Joan Jonas’s Lines in the Sand

In 2004 the visual artist Joan Jonas staged a video/installation/mixed media project of Helen in Egypt at the Tate Gallery. Almost sixty years since its composition, Jonas recasts H.D.’s long, neo-epic poem extending and exposing the possibilities of dramatic space and its dialogical connections with media that reinforce, undermine and raise questions about the interplay between dramatic space, poetry and narrativity. In her rendering of the Euripidean Helen, H.D. explores the ability of spatial transformation. She conceives Egypt as a locus of “spaceless limbo” or, to use Michel Foucault’s term, “Heterotopia,” a site “that can be found within the culture, simultaneously represented, contested, and inverted.” Within the timeline of the Trojan cycle, H.D. provides a spatial reading of a civilization transfixed by war. In the heterotopic space of the Tate, Jonas in turn, interweaves through her video installation performance Lines in the Sand the originary mythic text with H.D.’s neo-epic and references to H.D’s Tribute to Freud. Both women artists creatively exploit the ever-transformative dynamics of the myth to make a case about its impact on Western literary tradition.

Electrokinetic Lattice Boltzmann solver coupled to Molecular Dynamics: application to polymer translocation

We develop a theoretical and computational approach to deal with systems that involve a disparate range of spatio-temporal scales, such as those comprised of colloidal particles or polymers moving in a fluidic molecular environment. Our approach is based on a multiscale modeling that combines the slow dynamics of the large particles with the fast dynamics of the solvent into a unique framework. The former is numerically solved via Molecular Dynamics and the latter via a multi-component Lattice Boltzmann. The two techniques are coupled together to allow for a seamless exchange of information between the descriptions. Being based on a kinetic multi-component description of the fluid species, the scheme is flexible in modeling charge flow within complex geometries and ranging from large to vanishing salt concentration. The details of the scheme are presented and the method is applied to the problem of translocation of a charged polymer through a nanopores. In the end, we discuss the advantages and complexities of the approach