Corrosion-Resistant Steel-MgO Composites as Refractory Materials for Molten Aluminum Alloys.

In this study, a novel metal matrix composite based on 60 vol% 316L stainless steel and 40 vol% MgO manufactured by powder metallurgy technology was developed. The corrosion resistance of the developed steel-MgO composite material against molten aluminum alloy AlSi7Mg0.3 was investigated by means of wettability tests and long-term crucible corrosion tests.

Nightside condensation of iron in an ultrahot giant exoplanet.

Ultrahot giant exoplanets receive thousands of times Earth's insolation. Their high-temperature atmospheres (greater than 2,000 kelvin) are ideal laboratories for studying extreme planetary climates and chemistry. Daysides are predicted to be cloud-free, dominated by atomic species and much hotter than nightsides.

Rotational and Rotational-Vibrational Raman Spectroscopy of Air to Characterize Astronomical Spectrographs.

Raman scattering enables unforeseen uses for the laser guide-star system of the Very Large Telescope. Here, we present the observation of one up-link sodium laser beam acquired with the ESPRESSO spectrograph at a resolution λ/Δλ∼140 000. In 900 s on source, we detect the pure rotational Raman lines of ^{16}O_{2}, ^{14}N_{2}, and ^{14}N^{15}N (tentatively) up to rotational quantum numbers J of 27, 24, and 9, respectively.

Alternative Process Routes to Manufacture Porous Ceramics-Opportunities and Challenges.

Porous ceramics can be realized by different methods and are used for various applications such as cross-flow membranes or wall-flow filters, porous burners, solar receivers, structural design elements, or catalytic supports. Within this paper, three different alternative process routes are presented, which can be used to manufacture porous ceramic components with different properties or even graded porosity. The first process route is based on additive manufacturing (AM) of macro porous ceramic components.

The real-time stellar evolution of Sakurai's object.

After a hot white dwarf ceases its nuclear burning, its helium may briefly and explosively reignite. This causes the star to evolve back into a cool giant, whereupon it experiences renewed mass ejection before reheating. A reignition event of this kind was observed in 1996 in V4334 Sgr (Sakurai's object).