Definition of diastereomer. : a stereoisomer of a compound having two or more chiral centers that is not a mirror image of another stereoisomer of the same compound â compare enantiomer.
Most perennial weeds such as Johnsongrass. are also suppressed although vigorous plants or heavy in-. festations may lift plastic. Perennial sedges, and to a lesser. extent, grasses can puncture sheet mulches as the weeds. emerge from the soil, resulting in inadequate control.
Polyethylene sheeting is a common form of a Class I vapor retarder. Asphalt-saturated Kraft paper found on fiberglass batt insulation is a common form of a Class II vapor retarder. Latex and enamel paints are common forms of a Class III vapor retarder. An air barrier reduces the flow of air.