Effect of Main Elements (Zn, Mg, and Cu) on Hot Tearing Susceptibility During Direct-Chill Casting of 7xxx Aluminum Alloys

New 7xxx aluminum alloys with high alloying contents are being designed, which could induce serious hot tearing defects during direct-chill (DC) casting. Among all factors affecting hot tearing of 7xxx alloys, undoubtedly alloying elements play a significant role. In this study, the effect of main alloying elements (Zn, Mg, and Cu) on hot...

Comparative performance of different scale-down simulators of substrate gradients in Penicillium chrysogenum cultures: the need of a biological systems response analysis

In a 54 m³ large-scale penicillin fermentor, the cells experience substrate gradient cycles at the timescales of global mixing time about 20–40 s. Here, we used an intermittent feeding regime (IFR) and a two-compartment reactor (TCR) to mimic these substrate gradients at laboratory-scale continuous cultures. The IFR was applied to...