Helical inserts

FIGURE 10.31 The umbrella model of membrane chamiel protein insertion. Hydrophobic helices insert directly into the core of the membrane, with amphipathic helices arrayed on the surface like an open umbrella. A trigger signal (low pH or a voltage gradient) draws some of the amphipathic helices into and across the membrane, causing the pore to open. 

Figure 4.15 Mercury boiling heat transfer at wetted conditions inside a tantalum tube with helical insert. (From Hsia, 1970. Copyright 1970 by American Society of Mechanical Engineers, New York. Reprinted with permission.)... 

Fig. 3.6. Structure of the N EDD8 activator. (A) helical insertion containing the active-site Subunit structure of the NEDD8 activator. The cysteine in light green and the C-terminal UbL UBA3 subunit (upper left) is sho A/n A/ith the domain in orange. The APPBPl subunit...

For tubular and flat sheet membrane modules, one of the commonly used hydrodynamic techniques for the concentration polarization control is turbulence promoters, such as spacers used in spiral wound membrane modules, helical insert used in tubular membrane modules, and the corrugated membrane for the flat sheet membrane. Research has been conducted to assess the effect of the membrane flow channel spacers and inserts on the membrane filtration and to optimize their design. 

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