Earth heat transport occurs by conduction, mantle convection, hydrothermal convection, and volcanic advection. Heat dissipation is mostly achieved by passive conduction/convection. Solar ponds heat water by impeding this convection. Energy losses occur through heat conduction from workpiece to fixture, natural convection, and thermal radiation. A surface loses heat through conduction, evaporation, convection, and radiation. The convection heat transfer mode comprises one mechanism. Liquid cooling refers to cooling by means of the convection or circulation of a liquid. It is a smaller version of the convection oven. Both are also known as convection ovens. Heat can be removed through radiation, convection, or conduction. Heat may be transferred either by conduction, convection, or radiation. The types of cooling generally fall into two categories -- convection and conduction. Other mechanisms are convection and conduction. There are other important thermal loss mechanisms, including convection and evaporation. A plasma is hot and will rise due to convection air currents.