T cells and B cells differ in the form of the antigen they recognize, and this affects which antigens they can detect. B cells bind to antigen on invaders that are found in circulation outside the cells of the body, while T cells detect only invaders that have somehow entered the cells of the body.
ABS, DWV, Solid or Cell Core sewer pipe. The solid pipe is composed of ABS at 99% while the cell core is composed of a cellular foam between 2 layers of ABS which makes the cell core pipe lighter.
Orangeburg pipe. Orangeburg pipe (also known as fiber conduit, bituminous fiber pipe or Bermico) is bitumenized fiber pipe made from layers of wood pulp and pitch pressed together. It was used from the 1860s through the 1970s, when it was replaced by PVC pipe for water delivery and ABS pipe for drain-waste-vent (DWV) applications.