Why a Chest Tube is Placed. A chest tube is placed for a variety of reasons. One reason, as you mentioned, is to help the lung re-inflate when someone has a collapsed lung, also known as a pneumothorax. In that circumstance, a chest tube is inserted along the side of the ribs to allow the lung to reinflate.
A. Osmosis is the passive movement of water from an area high in water concentration, across a semi-permeable membrane, to an area low in water concentration.
Soil Water Movement Water movement in soil is from a zone of relatively high to low water potential. Movement may occur by saturated or unsaturated liquid flow or in the vapor phase. Total water potential under saturated conditions may include gravitational and pressure components.