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.
Polyethylenes are semi-crystalline materials with excellent chemical resistance, good fatigue and wear resistance, and a wide range of properties (due to differences in length of the polymer chain.) Polyethylenes are easy to distinguish from other plastics because they float in water.