State entropy

Deals with the concept of entropy, which serves as a means of determining whether or not a process is possible. Defines the zero entropy state for any substance in a single, pure quantum state as the absolute zero of temperature. 

The elastic contribution to Eq. (5) is a restraining force which opposes tendencies to swell. This constraint is entropic in nature the number of configurations which can accommodate a given extension are reduced as the extension is increased the minimum entropy state would be a fully extended chain, which has only a single configuration. While this picture of rubber elasticity is well established, the best model for use with swollen gels is not. Perhaps the most familiar model is still Flory s model for a network of freely jointed, random-walk chains, cross-linked in the bulk state by connecting four chains at a point [47] ... 

In a superconducting metal, some of the electrons are paired into the so-called cooper pairs which are all in the same zero entropy state and do not carry heat. Heat is carried only by unpaired electrons which are in energy states separated from cooper pairs by an energy gap AE(T). The number of unpaired electrons varies as exp(—AE/kBT). Hence ... 

From a thermodynamic standpoint, the space relaxation corresponds to the initial entropy of the system, i.e. to the initial entropy state on the catalyst surface, attained by establishing equilibrium between the ambient fluid and the catalyst surface. 

The time relaxation corresponds to the change in the initial entropy state. As it has been established by one of the present authors (6), it is possible to derive generalized thermodynamic forces and fluxes in the sense of Onsager s theory and to study e.g. stability problems of tubular reactors. 

At low concentrations, when uncharged polymers are dissolved in a solvent in which they do not crosslink or entangle, they possess a viscoelastic response through hydrodynamic and entropic effects. We can begin by considering an isolated chain in its quiescent state. The chain will be in constant motion. In the absence of any specific interactions, the chain will evolve to its maximum entropy state. We can represent the chain as N links or submolecules each with a length b. These links are formed from a few monomer units of the chain. The root mean square end-to-end length of the chain is... 

Diffusion in general, not only in the case of thin films, is a thermodynamically irreversible self-driven process. It is best defined in simple terms, such as the tendency of two gases to mix when separated by a porous partition. It drives toward an equilibrium maximum-entropy state of a system. It does so by eliminating concentration gradients of, for example, impurity atoms or vacancies in a solid or between physically connected thin films. In the case of two gases separated by a porous partition, it leads eventually to perfect mixing of the two. 

The importance of FIPI is twofold. It can be used to promote phase inversion without changing the thermodynamics of the system to obtain a higher entropy state, or it is possible to delay phase inversion while reducing the system entropy. The characteristics of the microstructure formed (such as emulsion droplet size) are dependent on the type of microstructure and deformation (shear, extension, or combined), as well as the deformation rate. To maximize the fluid micro-structure/flow field interactions, the flow fleld must be uniform, which requires the application of the flow field over a small processing volume, which can be achieved by using MFCS mixers or CDDMs. 

The molecular chaos assumption implies that the system is at statistical equilibrium. As in traditional kinetic theory this probability distribution function represents the maximum entropy state of the system. 

In summary, p-V work perturbs the energy levels and heat input perturbs the occupational probabilities of the available equilibrium states. One aspect of the second law identifies /T as a factor that makes the heat function an exact differential via the entropy state function... 

In which state are the eight balls at the higher entropy—state (i) or state (ii) ... 

When throttling, the entire change in availability is due to the negative change in entropy. Stated differently, the entropy term is the maximum loss of the ability of the stream to do work in transferring to its environmental (dead) state. Using Eg. (9,191. A is computed to be 434.9 Btu/lb, and consequently, 12% of its available work is lost in throttling. As considered subsequently in... 

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