A study has been carried out on the grain size distribution of cylindrical compacts obtained by consolidation of iron powder severely deformed by mechanical milling. Consolidation has been performed in two consecutive steps: cold and hot conditions. The hot one was done at two temperatures, namely 425 and 475oC. After milling, the iron powder has a grain size of 8 nm (± 4 nm) with an average ha...

This short communication discusses an algorithm suited for the generation of periodic microstructures of granular media. Its particular features are a user-defined grain size distribution, a representative volume element which is intrinsically periodic ab initio and a user-defined termination criterion, controlled by an increase of volume fraction. For low densities our particle packings resemb...

a r t i c l e i n f o We investigate the role of pressure solution in deformation of upper-to mid-crustal rocks using aggregates of halite as a room temperature analog for fluid-assisted deformation processes in the Earth's crust. Experiments evaluate the effects of initial grain size distribution on macroscopic pressure solution rate of the aggregate and compare the results to theoretical mode...

The dependence of acoustic backscatter variations on sediment grain-size distribution is examined using a combined analysis of 95 kHz side-scan data and approx. 300 grab samples from the New Jersey margin. We show that, under well-controlled circumstances, an unprecedented degree of correlation can be obtained between backscatter intensity and mean grain size. However, backscatter is disproport...

the use of acoustic waves in researches related to sea water is of most importance among scientistsrecently. since these waves are the only waves, transmitted in water with lowest attenuation and high speed, they canbe used in many scientific fields. the main goal of this research is to better understand the physics and mechanismsof sound-seabed interaction, including acoustic penetration, prop...

This work describes an implementation of the Potts model for simulation of grain growth in 2D on a distributed-memory parallel architecture. The simulation scheme utilizes continuous-time, asynchronous parallel version of the n-fold way algorithm. Each Processing Element (PE) carries a piece of the global simulation domain while the virtual topology of the PEs is in the form of a square grid in...

We study the effects of dust grain size on the spectral energy distribution (SED) of spherical circumstellar envelopes. Based on the self-similarity relations of dusty SEDs derived by Ivezić & Elitzur (1997), we expect an approximate invariance of the IR SED for models with different grain sizes. Approximate invariance follows from the fact that differently sized grains have similar optical pro...

While considerable efforts have been made to model the effects of grain coarsening, there has been little experimental verification of these models. Using serial sectioning techniques, the full 3-D morphology of 2098 b-titanium grains in Ti–21S are analyzed and directly compared to grain coarsening theories. The experimental grain size distribution and the distribution in the number of grain fa...

We present results of a study aimed at deriving fundamental properties of circumstellar debris disks from observed infrared to submillimeter spectral energy distributions. This investigation is motivated by increasing telescope/detector sensitivity, in particular the expected availability of the Space Infrared Telescope Facility (SIRTF) followed by the Stratospheric Observatory for Infrared Ast...