Second law of thermodynamics for open

The entropy equation can now be used to express the Clausius form of the second law of thermodynamics for open flow systems (e.g., [7] [145], p. 126). The inequality expresses that irreversible phenomena (diffusive momentum... 

Applying the first and second laws of thermodynamics for an open system to each of the four processes of the Brayton cycle yields ... 

Entropy balance, also called the second law of thermodynamics, for an open system... 

The earliest hint that physics and information might be more than just casually related actually dates back at least as far as 1871 and the publication of James Clerk Maxwell s Theory of Heat, in which Maxwell introduced what has become known as the paradox of Maxwell s Demon. Maxwell postulated the existence of a hypothetical demon that positions himself by a hole separating two vessels, say A and B. While the vessels start out being at the same temperature, the demon selectively opens the hole only to either pass faster molecules from A to B or to pass slower molecules from B to A. Since this results in a systematic increase in B s temperature and a lowering of A s, it appears as though Maxwell s demon s actions violate the second law of thermodynamics the total entropy of any physical system can only increase, or, for totally reversible processes, remain the same it can never decrease. Maxwell was thus the first to recognize a connection between the thermodynamical properties of a gas (temperature, entropy, etc.) and the statistical properties of its constituent molecules. 

Self-organization seems to be counterintuitive, since the order that is generated challenges the paradigm of increasing disorder based on the second law of thermodynamics. In statistical thermodynamics, entropy is the number of possible microstates for a macroscopic state. Since, in an ordered state, the number of possible microstates is smaller than for a more disordered state, it follows that a self-organized system has a lower entropy. However, the two need not contradict each other it is possible to reduce the entropy in a part of a system while it increases in another. A few of the system s macroscopic degrees of freedom can become more ordered at the expense of microscopic disorder. This is valid even for isolated, closed systems. Eurthermore, in an open system, the entropy production can be transferred to the environment, so that here even the overall entropy in the entire system can be reduced. 

Earth and biology are in a non-equilibrium state, but maintains a steady state, for which it is an important condition that the system is not closed but oper to the outside. Only under open conditions can such non-equilibrium but steady state be maintained. If earth were closed, all biological life would end, but the Earth is fortunately open to the universe. Based on tnis as well as on the first and thu second laws of thermodynamics, it was a natural consequence that we humans confronted the problem of environment and energy resource only as far as wt conduct energy cycles in the closed earth It is important for our future energy resources that the earth be open to the universe, i.e., ro the sun. 

First of all, we will touch a widely believed misunderstanding about impossibility of using the second law of thermodynamics in the analysis of open systems. Surely, the conclusion on inevitable degradation of isolated systems that follows from the second law of thermodynamics cannot be applied to open systems. And particularly unreasonable is the supposition about thermal death of the Universe that is based on the opinion of its isolation. The entropy production caused by irreversible energy dissipation is, however, positive in any system. Here we have a complete analogy with the first law of thermodynamics. Energy is fully conserved only in the isolated systems. For the open systems the balance equalities include exchange components which can lead to the entropy reduction of these systems at its increase due to internal processes as well. 

Irreversible processes produce entropy in any isolated, open, or closed system and Eq. (1.94) holds. In every macroscopic region of the system, the entropy production of irreversible processes is positive. A macroscopic region contains enough molecules for microscopic fluctuations to be negligible. The second law of thermodynamics states that the sum of the entropy production of all processes for any system and its environment is positive. When interfacial phenomena are considered, the entropy production is based per unit of surface area. 

The deduction of a criterion for the evolution of an open system to its stationary state resembles the classical thermodynamic problem of predict ing the direction of spontaneous irreversible evolution in an isolated system According to the Second Law of thermodynamics, in the latter case the changes go only toward the increase in entropy, the entropy being maximal at the final equilibrium state. 

From the point of view of macroscopic thermodynamics living organisms are energy transducers converting a source of energy,e.g. chemical substances or photons, into other forms of energy. As such they are subject to the constraints posed by the first and second laws of thermodynamics. As microorganisms are open systems and as such exist in a state outside equilibrium,non-equilibrium thermodynamics provide the perfect vehicle for a first approach to the description of their behaviour. 

In this chapter we develop expressions that relate heat and work to state functions those relations constitute the first and second laws of thermodynamics. We begin by reviewing basic concepts about work ( 2.1) that discussion leads us to the first law ( 2.2) for closed systems. Our development follows the ideas of Redlich [1]. Then we rationalize the second law ( 2.3) for closed systems, basing our arguments on those originally devised by Carath odory [2-4]. Finally, by straightforward applications of the stuff equations introduced in 1.4, we extend the first and second laws to open systems ( 2.4). 

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