Industry, sector and description for Universal Display. Universal Display researches, develops, and sells organic light emitting diode (OLED) technologies and materials for the flat-panel display industry.
The first requirement for all master horizons other than O horizons is that they are composed mostly of mineral material. It is very important to be able to differentiate organic from mineral material. Dark color of the A horizon is due to the mixing of humus with mineral.
A cross-section of soil top, revealing horizons. A soil horizon is a layer generally parallel to the soil crust, whose physical characteristics differ from the layers above and beneath. Each soil type usually has three or four horizons.