Macroscopic change

Figure 9-3 shows this schematically. If the partial pressure of the vapor is less than the equilibrium value (as in Figure 9-3A), the rate of evaporation exceeds the rate of condensation until the partial pressure of the vapor equals the equilibrium vapor pressure. If we inject an excess of vapor into the bottle (as in Figure 9-3Q, condensation will proceed faster than evaporation until the excess of vapor has condensed. The equilibrium vapor pressure corresponds to that concentration of water vapor at which condensation and evaporation occur at exactly the same rate (as in Figure 9-3B). At equilibrium, microscopic processes continue but in a balance that yields no macroscopic changes.

For chemical reactions, just as for phase changes, at equilibrium, microscopic processes continue but in a balance which gives no macroscopic changes. 

Finally the example of the ring spectra demonstrated that the MAS NMR spectroscopy can give a clear and detailed molecular picture for the explanation of macroscopic changes and bulk material properties. 

In terms of local irritation effects, AOS are reported to result in marked irritation of the eyes at concentrations at or above 1.0%, with slight effects being observed at 0.1% [147,148,150]. Repeated application to rat skin over 15 days at concentrations of 20% or 30% did not result in any macroscopic changes. Microscopic examination, however, did show atrophy of the stratum... 

In a film, the cooperative effort of the different molecular motors, between consecutive cross-linked points, promotes film swelling and shrinking during oxidation or reduction, respectively, producing a macroscopic change in volume (Fig. 18). In order to translate these electrochemically controlled molecular movements into macroscopic and controlled movements able to produce mechanical work, our laboratory designed, constructed, and in 1992 patented bilayer and multilayer103-114 polymeric... 

Using the metal reactivity series, students are to predict if a chemical reaction would occur when a coil of copper wire is placed in some aqueous silver nitrate in a test-tube. Students are to predict the macroscopic changes that they would expect, given the balanced chemical equation for the above reaction. 

This is a law about the equilibrium state, when macroscopic change has ceased it is the state, according to the law, of maximum entropy. It is not really a law about nonequilibrium per se, not in any quantitative sense, although the law does introduce the notion of a nonequilibrium state constrained with respect to structure. By implication, entropy is perfectly well defined in such a nonequilibrium macrostate (otherwise, how could it increase ), and this constrained entropy is less than the equilibrium entropy. Entropy itself is left undefined by the Second Law, and it was only later that Boltzmann provided the physical interpretation of entropy as the number of molecular configurations in a macrostate. This gave birth to his probability distribution and hence to equilibrium statistical mechanics. 

Art conservation, particularly painting restoration, is an important endeavor to preserve our cultural heritage and maintain the aesthetic value of an artistic piece. Chemical reactions occurring on a microscopic level are the origin of the macroscopic changes that we observe as ageing. 

Taken together, these biochemical and cellular transformations within the degenerating IVD result in macroscopic changes manifest as a dehydrated and fibrous NP, disorganized AF lamellae, and an inconspicuous boundary between the NP and AF. Concentric and/or radial annular tears, and NP fissure formations are also observed within the severely degenerated IVD, and an overall reduction in the central disc height may occur [11, 31]. Additionally, blood vessels and nerve endings have been found to infiltrate into the center of the disc, which may harbor inflammatory cells and their mediators. 

In summary, the macroscopic changes in energy measured in an experiment such as this are a direct reflection of microscopic energy changes occurring on the molecular level. The milk of a cappuccino coffee is warmed when steam passes through it because the steam... 

The d in Equation (5.1) means an infinitesimal change, whereas the A symbol here means a large, macroscopic, change. 

There is an additional layer of complexity that increases the coupling further. As described above, the universe is external to the solute/solvent system. Perhaps the universe represents some collective normal mode(s) of the solute/solvent system, whose response is separable (or approximately so) from the local solvation of the solvent to the solute. In particular, this occurs when the solute/solvent system contains a large number of solute particles whose properties change as a function of their individual dynamics. In the limit of high enough solute concentrations, the collective (macroscopic) change of these solutes thus leads to a change in the solvation for each of them individually. 

We have already noted that sedimentation and diffusion are opposing processes, the first tending to collect and the second to scatter. Let us now consider the circumstances under which these two tendencies equal each other. Once this condition is reached, of course, there will be no further macroscopic changes the system is at equilibrium. In order to formulate this problem, consider the unit cross section shown in Figure 2.15, in which the x direction is in the direction of either a gravitational or a centrifugal field. Suppose this field tends to pull... 

In conclusion, dielectric measurements seem to be insensitive to gelation. This can be explained by the fact that the dielectric probes, i.e., the ions which are practically always present in the reactive medium, give information only about local viscosities and not the macroscopic changes such as the viscosity near gelation. Nevertheless, dielectric measurements can be used to monitor processing in the pregel region. 

As is justified for most situations in process technology, we ignore macroscopic changes in the kinetic and/or potential energy of the flow in this process. Applying the first law of thermodynamics for flow processes, we may write... 

One of the well-known properties in the martensitic transition is that it undergoes macroscopic change in shape. This can be visualized by the illustration of Fig. 4. In Nitinol, no macroscopic shape change is observed. This can also be visualized by Fig. 3, in which the atomic shears take place in zigzag fashion. Since the atomic shears are all within interatomic distances macroscopically no shape change is observed. 

An attempt to make this application prompted the appearance of The Thermodynamics of Soil Solutions (Oxford University Press, 1981). Besides its evident purpose, to demonstrate the use of chemical thermodynamics, this book carried a leitmotif on the fundamental limitations of chemical thermodynamics for describing natural soils. These limitations referred especially to the influence of kinetics on stability, to the accuracy of thermodynamic data, and to the impossibility of deducing molecular mechanisms. The problem of mechanisms vis-a-vis thermodynamics cannot be expressed better than in the words of M. L. McGlashan 2 what can we learn from thermodynamic equations about the microscopic or molecular explanation of macroscopic changes Nothing whatever. What is a thermodynamic theory (The phrase is used in the titles of many papers published in reputable chemical journals.) There is no such thing. What then is the use of thermodynamic equations to the chemist They are indeed useful, but only by virtue of their use for the calculation of some desired quantity which has not been measured, or which is difficult to measure, from others which have been measured, or which are easier to measure. This point cannot be stated often enough. 

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