This is also known as thelaw of conservation of energy. The first law of thermodynamics is the application of the conservation of energy principle to heat and thermodynamic processes. The first law makes use of the key concepts of internal energy, heat, and system work. It is used extensively in the discussion of heat engines.
Definition of associate. 1 : closely connected (as in function or office) with another : sharing in responsibility or authority associate judges. 2 : having secondary or subordinate status associate membership in a society.
affiliation - the act of becoming formally connected or joined; welcomed the affiliation of the research center with the university. association - the act of consorting with or joining with others; you cannot be convicted of criminal guilt by association. reaffiliation - affiliation anew.