A getter comprising a calcium-aluminum compound including about 39% to about 43% calcium by weight produces a calcium vapor when sufficiently heated. The elements are spaced apart to provide spatial diversity and have a shape to provide operation in multiple frequency bands andor over a wide bandwidth of frequencies. The pixel structures are electrically connected to the corresponding scan lines and data lines. The hod processing facility includes a plurality of separate rooms for processing the food product, each including separate food processing machines, air handling systems, drain systems andor often-used supplies and tools. A data structure that represents an instance of the problem is received.