Separation of Spacecraft Noise From Geomagnetic Field Observations Through Density-Based Cluster Analysis and Compressive Sensing.

The use of magnetometers for space exploration is inhibited by magnetic noise generated by spacecraft electrical systems. Mechanical booms are traditionally used to extend magnetometers away from noise sources. If a spacecraft is equipped with multiple magnetometers, signal processing algorithms can be used to compare magnetometer measurements and remove stray magnetic noise signals.

First and second-order models for the vortex length in cylinder-on-cone cyclones based on large-eddy simulations.

The common design of cyclone separators is the cylinder-on-cone design, and the conical shape has a strong effect on the behavior of the vortex core low in the cyclone. The "vortex length" is the distance between the lip of the gas outlet tube and the position at which the core of the vortex attaches to the wall of the cyclone separation space. This occurs spontaneously at an axial position that, at present, cannot be predicted, although it has a profound effect on the cyclone operation, since, if the vortex is too short, it can lead to plugging and wear.

Spectrally resolved thermal emission of atmospheric gases measured by laser heterodyne spectrometry.

The demonstration of thermal infrared quantum cascade laser heterodyne spectrometry to resolve local thermodynamic equilibrium molecular emission lines from earth's atmospheric constituents is presented. The instrument is described, as well as the early steps towards radiometric calibration. Room temperature ethylene emission line measurements carried out in the laboratory are used to validate the instrument.

Order Parameters and Algorithmic Approaches for Detection and Demarcation of Interfaces in Hydrate-Fluid and Ice-Fluid Systems.

Some aspects of the use of order parameter fields in molecular dynamics simulations to delimit solid phases containing water, namely ice and hydrate, in both hydrophilic and hydrophobic fluids are examined; this includes the influences of rectangular meshes and of filtering on the quality of these parameters. Three order parameters are studied: the mass density, ρ; an angular tetrahedrality measure, Sg (Chau and Hardwick, Mol. Phys.

Free energy of separation of structure II clathrate hydrate in water and a light oil.

The adhesion forces and free energies of separation of structure II clathrate hydrates in vacuum and submerged in water and a model oil are investigated by molecular dynamics simulation. The water molecules are modeled by the TIP4P/ice model and the alkanes by the OPLS_AA force field. The results are compared with theory and earlier work.

Extended hard-sphere model and collisions of cohesive particles.

In two earlier papers the present authors modified a standard hard-sphere particle-wall and particle-particle collision model to account for the presence of adhesive or cohesive interaction between the colliding particles: the problem is of importance for modeling particle-fluid flow using the Lagrangian approach. This technique, which involves a direct numerical simulation of such flows, is gaining increasing popularity for simulating, e.g.

Extension of the hard-sphere particle-wall collision model to account for particle deposition.

Numerical simulations of flows of fluids with granular materials using the Eulerian-Lagrangian approach involve the problem of modeling of collisions: both between the particles and particles with walls. One of the most popular techniques is the hard-sphere model. This model, however, has a major drawback in that it does not take into account cohesive or adhesive forces.

Multiphase stochastic model for fluidized beds.

This article introduces a type of stochastic model, which we call a multiphase stochastic model, for the particle transport in bubbling fluidized beds, making it possible to take into account the finite velocity of fluidization bubbles and also extra particle transport due to "gulf streaming." An extended analysis of experimental results for particle transport in fluidized beds with gulf streaming is given, and results from the model are compared with the experimental results, showing that the model accounts for the effects seen.

Lifting a wet glass from a table: a microscopic picture.

Why is it so hard to lift a wet glass from a table? Is it easier when there is whiskey between the glass and the table? Macroscopically, the picture is quite simple: two surfaces have to be disrupted that are connected indirectly through hydrogen bonds and/or van der Waals forces. In the beginning, a surface has to be created leading to surface tension, and after that a liquid bridge has to be broken. Here we study the phenomenon at the microscopic level using molecular dynamics simulations.

An investigation of the consequences of primary dust explosions in interconnected vessels.

In this article Eulerian-Lagrangian 2D computer simulations of consequences of primary dust explosions in two vessels connected by a duct are described. After an explosion in the primary vessel a propagation of hot pressurised gases to the secondary vessel, initially uniformly filled with dust particles, is simulated. The gas phase is described by the standard equations and it is coupled with the particulate phase through the drag force and the convective heat transfer.