Work (thermodynamics) of the energy went out as heat, and how much as work. This can be summarized by saying that heat and work are not state functions of the system. This is in contrast to classical mechanics, where net work exerted by a particle is a state function. Pressure–volume work (or "PV" work) occurs when the volume of a system changes. "PV" work is often measured in units of litre-atmospheres where = . However, the litre-atmosphere is not a recognised unit in the SI system of units, which measures P in Pascal (Pa), V in m, and PV in Joule (J),
Energy & Environmental Science journals in the category "Engineering, Chemical", and first among 225 journals in the category "Environmental Sciences". "Energy & Environmental Science" publishes the following types of articles: Research Papers (original scientific work); Review Articles, Perspectives, and Minireviews (feature review-type articles of broad interest); Communications (original scientific work of an urgent nature), Opinions (personal, often speculative, viewpoints or hypotheses on a current topic), and Analysis Articles (in-depth examination of energy and environmental technologies, strategies, policies, and general conceptual frameworks of general interest). According to the Thomson Reuters Master Journal List and CASSI, this journal is indexed by the following services: Energy &