Work in 2012-2013 focused on studying gas permeability, diffusivity and solubility of polyimides and thermally rearranged (TR) polymers based on 3,3’-dihydroxy-4,4’diaminobiphenyl (HAB) and 2,2’-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA). To determine the effect of temperature on gas sorption, we studied H2 sorption in the HAB-6FDA polyimide and 3 partially converted HAB-6FD...

A simple method that incorporates coupling between bath and system and between individual bath modes is proposed. In Ž . the new locally propagating gaussian LPG approximation, the bath is modeled by Gaussians at each system site that propagate in time. Each site couples to others by the overlap of their Gaussians. In a test case with weak but non-negligible coupling, LPG is nearly as rapid as ...

Transport properties of impurities immersed in a granular gas undergoing homogenous cooling state are studied. The results are obtained from the Boltzmann-Lorentz kinetic equation for inelastic Maxwell models in d dimensions. The kinetic equation is solved by means of the Chapman-Enskog method up to first order in the density gradient of impurities. The mass and heat fluxes associated with impu...

Tracer gas studies and oxygen uptake measurements have shown that pressurized gas transport improves oxygen supply to roots in the wetland tree species Taxodium distichum L. Rich. (Taxodiaceae), Betula pubescens J.F. Ehrh. (Betulaceae), and Populus tremula L. (Salicaceae), but not in Acer pseudoplatanus L. and Ilex aquifolium L., which are found in drier habitats. In the deciduous tree species ...

Gibberellins (GAs) are phytohormones controlling major aspects of plant growth and development. Although previous studies suggested the existence of a transport of GAs in plants, the nature and properties associated with this transport were unknown. We recently showed through micrografting and biochemical approaches that the GA12 precursor is the chemical form of GA undergoing long-distance tra...