Energetics: Difference between revisions

Revision as of 17:59, 9 January 2006

Revision as of 18:07, 9 January 2006

Line 11:

== Principles of energetics ==

As a general statement of energy flows under transformation, the principles of energetics include the first four [[laws of thermodynamics]] which seek a rigorous description. However the precise place of the laws of thermodynamics within the principles of energetics is a topic currently under debate. If the ecologist [[Howard T. Odum]] was right, then the principles of energetics take into consideration a hierarchical ordering of energy forms, which aims to account for the concept of [[energy quality]]. Odum proposed 3 further energetic principles and one corollary that take [[Energy_quality#Ranking_energy_quality| energy hierarchy]] into account. The first four principles of energetics are taken from the main Wiki article on [[thermodynamics]]. The final four principles are taken from the [[ecological energetics]] of H.T. Odum.

* '''Zeroth principle of energetics'''

Line 24:

*: There seem to be two opinions on the fourth principle of energetics:

*:* The [[Onsager reciprocal relations]] are sometimes called the fourth law of thermodynamics. As the fourth law of thermodynamics Onsager reciprocal relations would constitute the fourth principle of energetics.

*:* In the field of [[ecological energetics]] H.T. Odum considered [[Maximum power| maximum power]], the fourth principle of energetics. H.T.Odum also proposed the [[Maximum empower]] principle as a corollary of the maximum power principle, and considered it to describe the propensities of evolutionary self-organisation.

* '''Fifth principle of energetics'''

*: The [[Transformity| energy quality factor]] increases hierarchically. From studies of ecological food chains, systems ecologist H.T.Odum proposed that energy transformations form a hierarchical series measured by [[Transformity]] increase (H.T.Odum 2000, p. 246). Flows of energy develop hierarchical webs in which inflowing energies interact and are transformed by work processes into energy forms of higher quality that feedback amplifier actions, helping to maximise the power of the system" — (H.T.Odum 1994, p. 251)

* '''Sixth principle of energetics'''

*: Material cycles have hierarchical patterns measured by the [[emergy]]/[[mass]] ratio that determines its zone and pulse frequency in the energy hierarchy. (H.T.Odum 2000, p. 246). M.T. Brown and V. Buranakarn write, "Generally, emergy per mass is a good indicator of recycle-ability, where materials with high emergy per mass are more recyclable" (2003, p. 1).

== See also ==

Line 45:

* S.W.Angrist and L.G.Helper (1973) ''Order and Chaos: Laws of Energy and Entropy'', Penguin, Australia, p. 34

* H.Hertz (1956) ''Principles of Mechanics'', Dover, U.S.A.

* H.T. Odum and R.T.Pinkerton (1955) 'Time's Speed Regulator', ''American Scientist'', Vol. 43, No. 2, p. 331.

* H.T. Odum (1994) ''Ecological and General Systems: An Introduction to Systems Ecology'', Colorado University Press.

* H.T. Odum (2000) 'An Energy Hierarchy Law For Biogeochemical Cycles', in Brown, M.T. (Ed.), ''Emergy Synthesis: Theory and Applications of the Emergy Methodology''. Proceedings of the First Biennial Emergy Analysis Research Conference, Centre for Environmental Policy, University of Florida, Gainesville, FL.

* J.R.Partington (1989) ''A Short History of Chemistry'', Dover, New York

* M.Tribus (1961) ''Thermostatics and Thermodynamics'', Van Nostrand, University Series in Basic Engineering, pp. 619-622.