The pit does not have any magical properties. What turns the guac brown is the air. If you can keep air from touching the guac then it will stay green. The pit will keep a portion away from the air, but what is more affective is to put plastic wrap over it and push it right down onto the surface.
In my experience, denuded skin is when the top layer is off, sore is very superficial and usual caused from a shearing force. As above, there are many taypes of foam backed dressings used in teh VA, depending on which VA you are at. I am familiar Allevyn but here is a site where you can compare.
Static pressure is the pressure when water is motionless. In a closed level piping system the static pressure is the same at every point. There are two way to create static pressure, by elevating water in tanks and reservoirs above where the water is needed and by utilizing a pump. Pumps can be used to increase or boost the pressure. Working pressure is pressure at any point in the sprinkler system when water is moving through the sprinkler system. Working pressure is always less than static pressure because the movement of water through a sprinkler pipe always results in a loss of pressure due to friction.