Критерій вибору ефективної стратегії функціонування транспортного підприємства в межах мікрологістичної системи

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

Polarizability and alignment of dielectric nanoparticles in an external electric field: Bowls, dumbbells, and cuboids

We employ the coupled dipole method to calculate the polarizability tensor of various anisotropic dielectric clusters of polarizable atoms, such as cuboid-, bowl-, and dumbbell-shaped nanoparticles. Starting from a Hamiltonian of a many-atom system, we investigate how this tensor depends on the size and shape of the cluster. We use the polarizability tensor to calculate the energy difference associated with turning a nanocluster from its least to its most favorable orientation in a homogeneous static electric field, and we determine the cluster dimension for which this energy difference exceeds the thermal energy such that particle alignment by the field is possible. Finally, we study in detail the (local) polarizability of a cubic-shaped cluster and present results indicating that, when retardation is ignored, a bulk polarizability cannot be reached by scaling up the syste

Can nonadditive dispersion forces explain chain formation of nanoparticles?

We study to what extent dielectric nanoparticles prefer to self-assemble into linear chains or into more compact structures. To calculate the Van der Waals (VdW) attraction between the clusters we use the Coupled Dipole Method (CDM), which treats each atom in the nanoparticle as an inducible oscillating point dipole. The VdW attraction then results from the full many-body interactions between the dipoles. For non-capped nanoparticles, we calculate in which configuration the VdW attraction is maximal. We find that in virtually all cases we studied, many-body effects only result in local potential minima at the linear configuration, as opposed to global ones, and that these metastable minima are in most cases rather shallow compared to the thermal energy. In this work, we also compare the CDM results with those from Hamaker-de Boer and Axilrod-Teller theory to investigate the influence of the many-body effects and the accuracy of these two approximate methods

Manipulating the self assembly of colloids in electric fields

During the last decade the focus in colloid science on selfassembly has moved from mostly spherical particles and interaction potentials to more and more complex particle shapes, interactions and conditions. In this minireview we focus on how external electric fields, which in almost all cases can be replaced by magnetic particles and fields for similar effects, are used to manipulate the self-assembly process of ever more complex colloids. We will illustrate typical results from literature next to examples of our own work on how electric fields are used to achieve a broad range of different effects guiding the self-assembly of colloidal dispersions. In addition, preliminary measurements and calculations on how electric fields can be used to induce lock-and-key interactions will be presented as well