Related papers: Physics of Grain Alignment
Grain piles embody the complex mechanics and kinematics of disordered granular materials, including solid-like and fluid-like behaviours, complex kinematics, and preparation history-dependent stress variation. It is widely believed that the…
We propose a mechanism to explain what occurs when a mixture of grains of different sizes and different shapes (i.e. different repose angles) is poured into a quasi-two-dimensional cell. Specifically, we develop a model that displays…
The quantization of energy levels in very nanoparticles suppresses dissipative processes that convert grain rotational kinetic energy into heat. For grains small enough to have GHz rotation rates, the suppression of dissipation can be…
In an external electric field, a system of conductive grains embedded in a dielectric matrix becomes unstable and relaxes towards a conductive state. We describe and discuss the elementary acts of this relaxation. When the grains packing…
We study the magnetic field structures in six giant filaments associated with the spiral arms of the Milky Way by applying the Velocity Gradient technique (VGT) to the 13CO spectroscopic data from GRS, Fugin, and SEDIGSM surveys. Compared…
Context. Planck observations demonstrated that the grain alignment efficiency is almost constant in the diffuse ISM. Aims. We test if the Radiative Torque (RAT) theory is compatible with observational constraints on grain alignment.…
As a smaller grain, which is attached on larger one, is growing, it pushes also the larger one and other grains in its surrounding. In a simulation of similar system, repulsive force such as contact force based on linear spring-dashpot…
It is well known that the polarized continuum emission from magnetically aligned dust grains is determined to a large extent by local magnetic field structure. However, the observed significant anticorrelation between polarization fraction…
We explore the structure of magnetic field lines in and around filaments in simulations of molecular clouds undergoing global, multi-scale gravitational collapse. In these simulations, filaments are not in a static equilibrium, but are…
If you walk on sand, it supports your weight. How do the disordered forces between particles in sand organize, to keep you from sinking? This simple question is surprisingly difficult to answer experimentally: measuring forces in three…
The coarse-graining approach to deriving the quantum Markovian master equation is revisited, with close attention given to the underlying approximations. It is further argued that the time interval over which the coarse-graining is…
Granular materials are known to separate by size under a variety of circumstances. Experiments presented here and elucidated by modeling and MD simulation document a new segregation mechanism, namely segregation by friction. The experiments…
The dynamical mechanisms underlying the grain evolution and growth are of fundamental importance in controlling the structural properties of large-scale polycrystalline materials, but the effects of lattice ordering and distinct atomic…
A significant fraction of main sequence stars observed interferometrically in the near infrared have slightly extended components that have been attributed to very hot dust. To match the spectrum appears to require the presence of large…
The thermodynamic theory of dislocation/grain boundary interaction, including dislocation pile-up against, absorption by, and transfer through the grain boundary, is developed for nonuniform plastic deformations in polycrystals. The case…
In interstellar dust grains, internal processes dissipate rotational kinetic energy. The dissipation is accompanied by thermal fluctuations, which transfer energy from the vibrational modes to rotation. Together, these processes are known…
Recent dust continuum surveys have shown that filamentary structures are ubiquitous along the Galactic plane. While the study of their global properties has gained momentum recently, we are still far from fully understanding their origin…
Context. Grains in circumstellar disks are believed to grow by mutual collisions and subsequent sticking due to surface forces. Results of many fields of research involving circumstellar disks, such as radiative transfer calculations, disk…
Rapidly spinning magnetic grains can acquire large magnetic dipole moments due to the Barnett effect. Here we study the new effect of Barnett magnetic dipole-dipole interaction on grain-grain collisions and grain growth, assuming grains…
Optical and infrared continuum polarization from the interstellar medium is known to generally be due to irregular dust grains aligned with the magnetic field. This provides an important tool to probe the geometry and strength of those…