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[en] High energy density laboratory experiments on Rayleigh-Taylor instability in nonlinear regime show the plasma behavior significantly different from classical simulation results. We include the effects of self-generated magnetic field and heat conduction in simulations aiming to improve agreement with experiments. We find maximum magnetic fields generated ∼11MG (β=0.091) without heat conduction (k=0), field growth saturated by t=20ns; and ∼1.7 MG with heat conduction taken into account. Strong magnetic fields in k=0 simulations affect flow dynamics, new modes are generated. Effect of weaker magnetic fields in simulations with physical values of k is insignificant; the main difference with classical RTI simulations is suppressed small scale features. In none of the simulations are mass extensions observed.

[en] New optical Hubble Space Telescope (HST), Spitzer Space Telescope, Galaxy Evolution Explorer, and Chandra observations of the single-nucleus, luminous infrared galaxy (LIRG) merger IC 883 are presented. The galaxy is a member of the Great Observatories All-sky LIRG Survey and is of particular interest for a detailed examination of a luminous late-stage merger due to the richness of the optically visible star clusters and the extended nature of the nuclear X-ray, mid-IR, CO, and radio emission. In the HST Advanced Camera for Surveys images, the galaxy is shown to contain 156 optically visible star clusters distributed throughout the nuclear regions and tidal tails of the merger, with a majority of visible clusters residing in an arc ∼3-7 kpc from the position of the mid-infrared core of the galaxy. The luminosity functions of the clusters have an α_F435W ∼ –2.17 ± 0.22 and α_F814W ∼ –2.01 ± 0.21, compared with V-band-derived values measured for the well-studied LIRG NGC 34 and the Antennae Galaxy of α ∼ –1.7 ± 0.1 and –2.13 ± 0.07, respectively. Further, the colors and absolute magnitudes of the majority of the clusters are consistent with instantaneous burst population synthesis model ages in the range of a few × 10⁷-10⁸ yr (for 10⁵ M_☉ clusters), but may be as low as few × 10⁶ yr with extinction factored in. The X-ray and mid-IR spectroscopies are indicative of predominantly starburst-produced nuclear emission, and the star formation rate, estimated based on the assumption that the radio and far-infrared luminosities are tracing the starburst population, is ∼80 M_☉ yr^–1. The kinematics of the CO emission and the morphology of both the CO and radio emission are consistent with the nuclear starburst being situated in a highly inclined disk 2 kpc in diameter with an infrared surface brightness μ_IR ∼ 2 × 10¹¹ L_☉ kpc^–2, a factor of 10 less than that of the Orion star-forming region. Finally, the detection of the [Ne V] 14.32 μm emission line is evidence that an active galactic nucleus (AGN) is present. The faintness of the line (i.e., [Ne V]/[Ne II] 12.8 μm ∼ 0.01) and the small equivalent width of the 6.2 μm polycyclic aromatic hydrocarbon feature (=0.39 μm) are both indicative of a relatively weak AGN.

[en] The design and initial operation of an in situ catalysis reaction cell for x-ray absorption spectroscopy measurements at high pressure is described. The design is based on an x-ray transparent tube fabricated from beryllium. This forms a true plug flow reactor for catalysis studies. The reactor is coupled to a portable microprocessor-controlled versatile feed system, and incorporates on-line analysis of reaction products. XAFS data recorded during the reduction of a NiRe/carbon catalyst at 4 bar are used to illustrate the performance of the reactor

[en] Since traditional handling mechanisms have an unpredictable behavior at micro scale, micro-assembly is a bottleneck in the development of hybrid micro-systems, and the development of new approaches is strongly demanded. In this paper, a recent study of the fabrication of a ceramics vacuum micro-gripper to handle parts in the range of hundreds of microns (300-1000) is presented. Among the possible micro manufacturing processes, micro-EDM has been selected as proving to be a very competitive fabrication technology for the manufacturing of ultra miniature components and micro sized features. The influence of the process parameters on the machining performance of interest is firstly investigated; then, the experimental results on machining the micro gripper are presented, finally concluding remarks are given.

[en] We present the results of a Hubble Space Telescope ACS/HRC FUV, ACS/WFC optical study into the cluster populations of a sample of 22 Luminous Infrared Galaxies in the Great Observatories All-Sky LIRG Survey. Through integrated broadband photometry, we have derived ages and masses for a total of 484 star clusters contained within these systems. This allows us to examine the properties of star clusters found in the extreme environments of LIRGs relative to lower luminosity star-forming galaxies in the local universe. We find that by adopting a Bruzual and Charlot simple stellar population model and Salpeter initial mass function, the age distribution of the clusters declines as $dN/d\mathrm{\tau <!--\; ??\; -->}={\mathrm{\tau <!--\; ??\; -->}}^{-<!--\; ???\; -->0.9+/-<!--\; ???\; -->0.3}$, consistent with the age distribution derived for the Antennae Galaxies, and interpreted as evidence for rapid cluster disruption occurring in the strong tidal fields of merging galaxies. The large number of ${10}^6{M}_{\odot <!--\; ???\; -->}$ young clusters identified in the sample also suggests that LIRGs are capable of producing more high-mass clusters than what is observed to date in any lower luminosity star-forming galaxy in the local universe. The observed cluster mass distribution of $dN/dM=M^{-<!--\; ???\; -->1.95+/-<!--\; ???\; -->0.11}$ is consistent with the canonical −2 power law used to describe the underlying initial cluster mass function (ICMF) for a wide range of galactic environments. We interpret this as evidence against mass-dependent cluster disruption, which would flatten the observed CMF relative to the underlying ICMF distribution.