Retin-A (tretinoin) is a form of vitamin A that helps the skin renew itself. The Retin-A and Avita brands of tretinoin are used to treat acne. The Renova brand of tretinoin is used to reduce the appearance of fine wrinkles and mottled skin discoloration, and to make rough facial skin feel smoother. Retin-A may also be used for purposes not listed in this medication guide.
Waste Stream. The total flow of solid waste from homes, businesses, institutions, and manufacturing plants that is recycled, burned, or disposed of in landfills, or segments thereof such as the residential waste stream or the recyclable waste stream..
(from Wikimedia Commons). Stream load is a geologic term referring to the solid matter carried by a stream (Strahler and Strahler, 2006). Erosion and bed shear stress continually remove mineral material from the bed and banks of the stream channel, adding this material to the regular flow of water. The amount of solid load that a stream can carry, or stream capacity, is measured in metric tons per day, passing a given location.