Interdiction Torch (Equivalent Exchange)

The interdiction torch has the push-force effect as an activated Rending Gale, although slightly less reliable. When powered via redstone-pulses, however, the push force is magnified specifically.
"Redstone pulses" refers to the alternating current produced by a 5-clock or similar mechanisms. Simply placing a redstone torch by your interdiction torch isn't enough. Make sure for the strongest base defense, you have such a mechanism built for maximum usefulness of your interdiction fields.
The effect can be somewhat sporadic and is not guaranteed to be perfectly reliable at distances beyond about 4 or 5 blocks, but generally, a single torch can protect a player when placed on the ground, and a torch or two in a mining tunnel will guarantee virtually anything to be barred from entry.
In addition, putting an interdiction torch in an alchemical chest will cause it to produce light and repel mobs.