A Distributed Communication System for Integration with Logistics Software

Truckage companies need continuous and up-to-date information about their business processes in order to respond quickly to customers’ needs and problems emerging during transport processes. Therefore a reliable and user-friendly communication system is required, which improves the relationship between drivers and dispatchers. The project ”Mobile Spedition im Web (SpiW)**” presented here, develops a mobile communication system, which focuses on the driver/dispatcher interaction. The main goals are integration with legacy logistics software and the possible use of new telematics and communication techniques. To achieve these goals, a component based architecture allows the later change and extension of components, making it possible to add new features to the system as they become available. A distributed workflow server supports the adjustment of business processes to individual needs

Crystallization in suspensions of hard spheres: A Monte Carlo and Molecular Dynamics simulation study

The crystallization of a metastable melt is one of the most important non equilibrium phenomena in condensed matter physics, and hard sphere colloidal model systems have been used for several decades to investigate this process by experimental observation and computer simulation. Nevertheless, there is still an unexplained discrepancy between simulation data and experimental nucleation rate densities. In this paper we examine the nucleation process in hard spheres using molecular dynamics and Monte Carlo simulation. We show that the crystallization process is mediated by precursors of low orientational bond-order and that our simulation data fairly match the experimental data sets

The effects of polydispersity and metastability on crystal growth kinetics

We investigate the effect of metastable gas-liquid (G-L) separation on crystal growth in a system of either monodisperse or slightly size-polydisperse square well particles, using a simulation setup that allows us to focus on the growth of a single crystal. Our system parameters are such that, inside the metastable G-L binodal, a macroscopic layer of the gas phase "coats" the crystal as it grows, consistent with experiment and theoretical free energy considerations. Crucially, the effect of this metastable G-L separation on the crystal growth rate depends qualitatively on whether the system is polydisperse. We measure reduced polydispersity and qualitatively different local size ordering in the crystal relative to the fluid, proposing that the required fractionation is dynamically facilitated by the gas layer. Our results show that polydispersity and metastability, both ubiquitous in soft matter, must be considered in tandem if their dynamical effects are to be understood.Comment: Published in Soft Matter. DOI: 10.1039/C3SM27627

Measuring every particle's size from three-dimensional imaging experiments

Often experimentalists study colloidal suspensions that are nominally monodisperse. In reality these samples have a polydispersity of 4-10%. At the level of an individual particle, the consequences of this polydispersity are unknown as it is difficult to measure an individual particle size from microscopy. We propose a general method to estimate individual particle radii within a moderately concentrated colloidal suspension observed with confocal microscopy. We confirm the validity of our method by numerical simulations of four major systems: random close packing, colloidal gels, nominally monodisperse dense samples, and nominally binary dense samples. We then apply our method to experimental data, and demonstrate the utility of this method with results from four case studies. In the first, we demonstrate that we can recover the full particle size distribution {\it in situ}. In the second, we show that accounting for particle size leads to more accurate structural information in a random close packed sample. In the third, we show that crystal nucleation occurs in locally monodisperse regions. In the fourth, we show that particle mobility in a dense sample is correlated to the local volume fraction.Comment: 7 pages, 5 figure

Crystal nuclei and structural correlations in two-dimensional colloidal mixtures: experiment versus simulation

We examine binary mixtures of superparamagnetic colloidal particles confined to a two-dimensional water-air interface both by real-space experiments and Monte-Carlo computer simulations at high coupling strength. In the simulations, the interaction is modelled as a pairwise dipole-dipole repulsion. While the ratio of magnetic dipole moments is fixed, the interaction strength governed by the external magnetic field and the relative composition is varied. Excellent agreement between simulation and experiment is found for the partial pair distribution functions including the fine structure of the neighbour shells at high coupling. Furthermore local crystal nuclei in the melt are identified by bond-orientational order parameters and their contribution to the pair structure is discussed

A Distributed Communication System for Integration with Logistics Software

Truckage companies need continuous and up-to-date information about their business processes in order to respond quickly to customers’ needs and problems emerging during transport processes. Therefore a reliable and user-friendly communication system is required, which improves the relationship between drivers and dispatchers. The project ”Mobile Spedition im Web (SpiW)**” presented here, develops a mobile communication system, which focuses on the driver/dispatcher interaction. The main goals are integration with legacy logistics software and the possible use of new telematics and communication techniques. To achieve these goals, a component based architecture allows the later change and extension of components, making it possible to add new features to the system as they become available. A distributed workflow server supports the adjustment of business processes to individual needs