Renal agenesis. Renal agenesis is a medical condition in which one (unilateral) or both (bilateral) fetal kidneys fail to develop.
Polycrystalline cells are composed of multiple silicon crystals, which is a cheaper way to manufacture solar modules. Put simply, these cells are easier for a factory to produce, so they are less expensive. Polycrystalline cells are made by several methods, but most commonly with a cast of molten silicon.
Poly(acrylic acid) or PAA (CAS number 9003-1-04) is a type of polymer. The monomer of poly(acrylic acid) is Acrylic Acid. In a water solution at neutral pH, many of the side chains of PAA will lose their protons and acquire a negative charge. Dry PAA is a white solid.