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Single scale realizations

The main purpose of this example is to provide a very simple but still physically meaningful illustration of the Legendre time evolution introduced above. The physical system that we have in mind is a polymeric fluid. We regard it as Simha and Somcynski (1969) do in their equilibrium theory but extend their analysis to the time evolution. As the state variables we choose [Pg.96]

The quantity q has the physical interpretation of the free volume. It is the state variable used in the Simha-Somcynski equilibrium theory of polymeric fluids (Simha and Somcynski, 1969). The new variable p that we adopt has the meaning of the velocity (or momentum) associated with q. [Pg.96]

The polymeric fluid that we investigate with the state variables (58) is thus static (i.e., without any macroscopic flow) and spatially homogeneous. The only time evolution that takes place in it is the evolution of the internal structure characterized by two scalars q, p. [Pg.96]

The physical insight involved in the Simha-Somcynski theory and an additional insight that we need to extend it to the time evolution will now be expressed in the building blocks of (55). We shall construct a particular realization of (55). We begin with the state variables. They have already been specified in (58). [Pg.96]

Now we proceed to specify the kinematics of (58). In order that the eta-function h (that remain unspecified at this point) and the number of moles n be preserved in the nondissipative time evolution (i.e., the time evolution governed by the first term on the right-hand side of (55)), the matrix L has to be such that Lhx = 0 and Lnx = 0. This degeneracy can be discussed more easily if we pass from the state variables x to a new set of state [Pg.96]


Gaussian errors with standard deviations 1, 4, 4, 3, and 1, respectively. The performance of maximum likelihood, single-scale Bayesian, and multiscale Bayesian rectification are compared by Monte-Carlo simulation with 500 realizations of 2048 measurements for each variable. The prior probability distribution is assumed to be Gaussian for the single-scale and multiscale Bayesian methods. The normalized mean-square error of approximation is computed as,... [Pg.431]

The mean and standard deviation of the MSE for 500 realizations of the 2048 measurements per variable are summarized in Table 1, and are similar to those of Johnston and Kramer. The average and standard deviation of the mean-squared errors of single-scale and multiscale Bayesian rectification are comparable, and smaller than those of maximum likelihood rectification. The Bayesian methods perform better than the maximum likelihood approach, since the empirical Bayes prior extracts and utilizes information about the finite range of the measurements. In contrast, the maximum likelihood approach implicitly assumes all values of the measurements to be equally likely. If information about the range of variation of the rectified values is available, it can be used for maximum likelihood rectification, leading to more accurate results. For this example, since the uniformly distributed uncorrelated measurements are scale-invariant in nature, the performance of the single-scale and multiscale Bayesian methods is comparable. [Pg.431]

Recent demands for polymeric materials request them to be multifunctional and high performance. Therefore, the research and development of composite materials have become more important because single-polymeric materials can never satisfy such requests. Especially, nanocomposite materials where nanoscale fillers are incorporated with polymeric materials draw much more attention, which accelerates the development of evaluation techniques that have nanometer-scale resolution." To date, transmission electron microscopy (TEM) has been widely used for this purpose, while the technique never catches mechanical information of such materials in general. The realization of much-higher-performance materials requires the evaluation technique that enables us to investigate morphological and mechanical properties at the same time. AFM must be an appropriate candidate because it has almost comparable resolution with TEM. Furthermore, mechanical properties can be readily obtained by AFM due to the fact that the sharp probe tip attached to soft cantilever directly touches the surface of materials in question. Therefore, many of polymer researchers have started to use this novel technique." In this section, we introduce the results using the method described in Section 21.3.3 on CB-reinforced NR. [Pg.597]

Alivisatos and coworkers reported on the realization of an electrode structure scaled down to the level of a single Au nanocluster [24]. They combined optical lithography and angle evaporation techniques (see previous discussion of SET-device fabrication) to define a narrow gap of a few nanometers between two Au leads on a Si substrate. The Au leads were functionalized with hexane-1,6-dithiol, which binds linearly to the Au surface. 5.8 nm Au nanoclusters were immobilized from solution between the leads via the free dithiol end, which faces the solution. Slight current steps in the I U) characteristic at 77K were reflected by the resulting device (see Figure 8). By curve fitting to classical Coulomb blockade models, the resistances are 32 MQ and 2 G 2, respectively, and the junction... [Pg.112]

Demonstration of the capability of electrodeposition to produce materials with predesignable, variable, and controllable composition down to practically the atomic scale constitutes an important step toward the realization of custom-tailored materials. On the theoretical side, the lack of a single satisfactory theory for the possible explanation of the different empirical results is somewhat disappointing. [Pg.305]

Extraction of 25 different binary mixtures of racemic acids (2-(4-isobutylphenyl)-propionic acid (1), and cis- and trans-chrysanthemic (2)), and various chiral bases with supercritical carbon dioxide permitted the conclusion that molecular chiral differentiation in a supercritical fluid is more efficient than in conventional solvents. In the majority of cases, however, complete separation could not be achieved. In five cases, remarkable partial resolutions were realized (30-75% ee) and resolution was possible on a preparative scale. The pair ds-chrysanthemic acid and (S)-(-i-)-2-(benzylamino)-1-butanol (3) was studied in detail. Pressure, temperature, and time, as well as the molar ratio of base and acid, had a marked influence on the quantity and quality of the products. Increasing pressure or decreasing temperature resulted in higher ee values. (-)-cw-Chrysanthemic acid in 99% ee was obtained from the raffinate in a single extraction step. Multiple extractions produced the (-i-)-cA-acid in 90% ee (see fig. 6.3) (Simandi et al., 1997). [Pg.147]


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