Related papers: Ice aggregate contacts at the nm-scale
Fractals -- objects with non-integer dimensions -- occur in manifold settings and length scales in nature, ranging from snowflakes and lightning strikes to natural coastlines. Much effort has been expended to generate fractals for use in…
The current model of planet formation lacks a good understanding of the growth of dust particles inside the protoplanetary disk beyond mm sizes. In order to investigate the low-velocity collisions between this type of particles, the…
The results of experiments on the formation of molecular hydrogen on low density and high density amorphous ice surfaces are analyzed using a rate equation model. The activation energy barriers for the relevant diffusion and desorption…
Contacts between particles in dense, sheared suspensions are believed to underpin much of their rheology. Roughness and adhesion are known to constrain the relative motion of particles, and thus globally affect the shear response, but an…
Neutron stars exhibit magnetic fields and densities far beyond those achievable in terrestrial laboratories, offering a natural probe of strongly interacting matter under extreme conditions. Using observationally anchored mass-radius…
Unopposed radiative cooling in clusters of galaxies results in excessive mass deposition rates. However, the cool cores of galaxy clusters are continuously heated by thermal conduction and turbulent heat diffusion due to minor mergers or…
Gravitational coupling between young planets and their parent disks is often explored using numerical simulations, which typically treat the disk thermodynamics in a highly simplified manner. In particular, many studies adopt the locally…
The properties of small clusters can differ dramatically from the bulk phases of the same constituents. In equilibrium, cluster assembly has been recently explored, whereas out of equilibrium, the physical principles of clustering remain…
Our current understanding of the physical processes of star formation is reviewed, with emphasis on processes occurring in molecular clouds like those observed nearby. The dense cores of these clouds are predicted to undergo gravitational…
Vertically pointing Doppler radar has been used to study the evolution of ice particles as they sediment through a cirrus cloud. The measured Doppler fall speeds, together with radar-derived estimates for the altitude of cloud top, are used…
(ABBREVIATED) Understanding the formation of stars in galaxies is central to much of modern astrophysics. In this review the relation between interstellar turbulence and star formation is discussed. Supersonic turbulence can provide support…
Kinetic Monte Carlo approach is developed to study aspects of sintering of dispersed nanoparticles of bimodal size distributions. We explore mechanisms of neck development when sintering is initiated at elevated temperatures for nanosize…
Gravitationally unstable disks can fragment and form bound objects provided that their cooling time is short. In protoplanetary disks radiative cooling is likely to be too slow to permit formation of planets by fragmentation within several…
We investigate experimentally phenomenon of turbulent thermal diffusion of micron-size solid particles in an inhomogeneous convective turbulence forced by one vertically-oriented oscillating grid in an air flow. This effect causes formation…
Materials that are strong, ultra-light weight and tough are in demand for a range of applications, requiring architectures and components carefully designed from the micrometer down to nanometer scales. Nacre-a structure found in many…
Context. Particles in protoplanetary disks go through a number of phases that are dominated by collisions. In each of these events, grains exchange electrical charge via triboelectric effects. This enhances the stability of particle…
We have predicted theoretically and detected in laboratory experiments a new type of particle clustering (tangling clustering of inertial particles) in a stably stratified turbulence with imposed mean vertical temperature gradient. In this…
The objective of this paper is to help shedding some light on the nature and the properties of the cold structures formed via thermal instability in the magnetized atomic interstellar medium. To this end, we searched for clumps formed in…
I present a review of nonthermal processes in the large scale structure of the universe. After examining the properties of cosmological shock waves and their role as particle accelerators, I discuss the main observational facts, from radio…
We present a semi-analytic model for the growth, drift, desorption, and fragmentation of millimeter- to meter-sized particles in protoplanetary disks. Fragmentation occurs where particle collision velocities exceed critical fragmentation…