Barricade, from the French barrique (barrel), is any object or structure that creates a barrier or obstacle to control, block passage or force the flow of traffic in the desired direction. Adopted as a military term, a barricade denotes any improvised field fortification, most notably on the city streets during urban warfare.
Thermodynamics is a branch of natural science concerned with heat and its relation to energy and work. It defines macroscopic variables (such as temperature, internal energy, entropy, and pressure) that characterize materials and radiation, and explains how they are related and by what laws they change with time. Thermodynamics describes the average behavior of very large numbers of microscopic constituents, and its laws can be derived from statistical mechanics.
