By its very nature, vitamin A causes drying of the skin and exfoliation. A bevy of prescription and OTC vitamin A topical preparations make use of this side effect to treat a variety of skin concerns. The term Retinoid refers to any Vitamin A based molecule. It's a category, similar to saying antibiotic. They may be related, but some are stronger and more effective than others.
Pototype sheets for Weld Quality Workmanship Standard. Undercut. Definition: A groove cut at the toe of the weld by the welding arc and left. unfilled. Depth of undercut shall not exceed 1/32.
Figure 6-7.Applications of double welds. A series of bead welds overlaid on the face of a joint. is called buttering, Figure 6-13. Buttered welds are often. used to join dissimilar metals. A series of overlaid welds. on the surface of a part to protect the base material is. called surfacing or cladding. Refer to Figure 6-14.