Methods comprising: placing particulates in a test column; adding a fluid medium comprising a salt solution to the test column; placing the column under test conditions, wherein the test conditions comprise target temperature and target pressure; maintaining test conditions for a target test duration; and, analyzing the particulates. The satellite based communication system has two links for duplex communication, i. In this manner, any difference between the threshold voltage V1 of the amplitude amplifying logic circuit 20 and the reference voltage can be absorbed. An exhaust exhausts a portion of the inside air to allow more outside air to be drawn into the aircraft. The ceiling mount light has a sensitivity regulating switch to adjust the level of sensitivity up to about 30 feet in the 360-degree viewing field. The contact pads include aluminum.