We introduce two improvements in the numerical scheme to simulate collision and slow shearing of irregular particles. First, we propose an alternative approach based on simple relations to compute the frictional contact forces. The approach improves efficiency and accuracy of the Discrete Element Method (DEM) when modeling the dynamics of the granular packing. We determine the proper upper limi...

Complex colloidal fluids, such as emulsions stabilized by particles with complex shapes, play an important role in many industrial applications. However, understanding their physics requires a study at sufficiently large length scales while still resolving the microscopic structure of a large number of particles and of the local hydrodynamics. Due to its high degree of locality, the lattice Bol...

Using DEM (Discrete Element Method), a model is presented to simulate the breakage of two-dimensional polygonshaped particles. In this model, shapes of the particles generated after breakage are predefined and each uniform (uncracked) particle is replaced with smaller inter-connected sub-particles. If the bond between these sub-particles breaks, breakage will happen. With the help of this model...

We present a new code (companion) that identifies bound systems of particles in O(N logN) time. Simple binaries consisting of pairs of mutually bound particles and complex hierarchies consisting of collections of mutually bound particles are identifiable with this code. In comparison, brute force binary search methods scale as O(N2) while full hierarchy searches can be as expensive as O(N3), ma...

Radioactive particles from three locations were investigated for elemental composition, oxidation states of matrix elements, and origin. Instrumental techniques applied to the task were scanning electron microscopy, X-ray and gamma-ray spectrometry, secondary ion mass spectrometry, and synchrotron radiation based microanalytical techniques comprising X-ray fluorescence spectrometry, X-ray fluor...

The Aerospace Research Laboratory at the University of Virginia currently uses Particle Image Velocimetry (PIV) to measure the velocity fields of flow through a Mach 2 Scramjet Test Section. PIV is the method of tracking seed particles as they are carried through the flow, and using their velocities to create a velocity field. This method is limited by seed particles coating the windows, known ...

A size-segregated aerosol dynamics model UHMA (University of Helsinki Multicompo-nent Aerosol model) was developed for studies of multicomponent tropospheric aerosol particles. The model includes major aerosol microphysical processes in the atmosphere with a focus on new particle formation and growth; thus it incorporates particle 5 coagulation and multicomponent condensation, applying a revise...

We developed a new method of transforming Japanese case particles when transforming Japanese passive sentences into active sentences. It separates training data into each input particle and uses machine learning for each particle. We also used numerous rich features for learning. Our method obtained a high rate of accuracy (94.30%). In contrast, a method that did not separate training data for ...

A size-segregated aerosol dynamics model UHMA (University of Helsinki Multicomponent Aerosol model) was developed for studies of multicomponent tropospheric aerosol particles. The model includes major aerosol microphysical processes in the atmosphere with a focus on new particle formation and growth; thus it incorporates particle coagulation and multicomponent condensation, applying a revised t...