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.
Other polyurethane is a thermoplastic that resembles other kinds of plastic, metal or fiberglass. Thermoplastics are rigid and smooth, with a sealed surface that is impermeable to water. These are used when strength and durability are important, such as in seats at an airport terminal or packaging crates on a truck.