Критерій вибору ефективної стратегії функціонування транспортного підприємства в межах мікрологістичної системи

Обґрунтовується критерій вибору ефективної стратегії функціонування транспортного підприємства в межах мікрологістичної системи

Монголы на Западе

We explicitly calculate the orientation-dependent second virial coefficient of short charged rods in an electrolytic solvent, assuming the rod-rod interactions to be a pairwise sum of hard-core and segmental screened- Coulomb repulsions. From the parallel and isotropically averaged second virial coefficient, we calculate the effective length and diameter of the rods, for charges and screening lengths that vary over several orders of magnitude. Using these effective dimensions, we determine the phase diagram, where we distinguish a lowcharge and strong-screening regime with a liquid crystalline nematic and smectic phase, and a high-charge and weak-screening regime with a plastic crystal phase in the phase diagram

Sedimentation stacking diagrams of binary mixtures of thick and thin hard rods

We use Onsager theory and the local density approximation to study sedimentation-diffusion equilibrium density profiles of binary mixtures of thick and thin hard rods. We construct stacking diagrams for three diameter ratios, and find that even a simple spindle-shaped phase diagram with only isotropic-nematic demixing can lead to counter-intuitive stacking sequences such as an isotropic phase sandwiched between two nematic phases. For the most complex phase diagram considered here, we find sixteen distinct stacking sequences, including several with five sedimented layers. By adding sedimentation paths to composition-pressure and density-density phase diagrams and calculating density and composition profiles, we show that conclusions about bulk phase diagrams of binary mixtures on the basis of sedimentation-diffusion equilibria should be drawn warily.Comment: 9 pages, 8 figures, extended discussion in section 4, added references, minor changes to figures (results unchanged

Electrostatics in liquids: from electrolytes and suspensions towards emulsions and patchy surfaces

These lecture notes describe ionic screening of liquid-immersed charged surfaces within the linear and the nonlinear Poisson–Boltzmann theory. The classic Gouy–Chapman description of a single charged planar surface is extensively described, as well as its linearised version and the connection with charge renormalisation. We also consider effective ion-mediated electrostatic interactions between suspended colloidal particles in some detail, and in addition we study Debye–Hückel theory for bulk electrolytes. We argue that relatively straightforward extensions of these basic notions can be used to describe systems of recent interest, e.g. patchy surfaces, oil–water interfaces, and Pickering emulsions. A number of references to recent literature is included

Inflation of the screening length induced by Bjerrum pairs

Within a modified Poisson–Boltzmann theory we study the effect of Bjerrum pairs on the typical length scale 1/¯κ over which electric fields are screened in electrolyte solutions, taking into account a simple association–dissociation equilibrium between free ions and Bjerrum pairs. At low densities of Bjerrum pairs, this length scale is well approximated by the Debye length 1/κ ∝ 1/ √ ρs, with ρs the free-ion density. At high densities of Bjerrum pairs, however, we find 1/¯κ ∝ √ ρs, which is significantly larger than 1/κ due to the enhanced effective permittivity of the electrolyte, caused by the polarization of Bjerrum pairs. We argue that this mechanism may explain the recently observed anomalously large colloid-free zones between an oil-dispersed colloidal crystal and a colloidal monolayer at the oil–water interface