Volume fluctuations

Temporal alterations in peripheral chemoreceptors are rare in vertebrates, but this group provides an example of transient enhancement of signal capture efficiency. The Red-backed salamander (Plethodon cinereus) shows dimorphic and seasonal VNO volume fluctuations. Males always possess a significantly larger vomeronasal area, and both... 

The same pseudo-ensemble concept has been used by Camp and Allen [44] to obtain a pseudo-Gibbs method in which particle transfers are substituted by volume fluctuations of the two phases. The volume fluctuations are unrelated to the ones required for pressure equality (10.7) but are instead designed to correct imbalances in the chemical potentials of some of the components detected, for example, by test particle insertions. 

While the main driving force in [43, 44] was to avoid direct particle transfers, Escobedo and de Pablo [38] designed a pseudo-NPT method to avoid direct volume fluctuations which may be inefficient for polymeric systems, especially on lattices. Escobedo [45] extended the concept for bubble-point and dew-point calculations in a pseudo-Gibbs method and proposed extensions of the Gibbs-Duhem integration techniques for tracing coexistence lines in multicomponent systems [46]. 

The density dependence of the entropy can also be studied by introducing fluctuations in volume rather than particle number. Typically the particle number approach is favored the computational demands of volume scaling moves scale faster with system size than do addition and deletion moves. Nevertheless, the Wang-Landau approach provides a means for studying volume fluctuations as well. In this case, the excess entropy is determined as a function of volume and potential energy for fixed particle number one, therefore, calculates (V, U). Here the microstate probabilities follow ... 

F. M. Richards, Packing defects, cavities, volume fluctuations and access to the interior of proteins, Carlsberg Res. Commun. 44, 47-63 (1979). 

Imports of distillate fuels have varied from year to year since the 1970s. Since 1975, imports of distillate fuel oils such as fuel oils no. 1 and no. 2 into the United States have been low compared to the amount of distillate fuel oils produced in the United States (API 1991). Annual import volumes fluctuated between... 

Tanaka et al. found a critical point at the zero-osmotic pressure condition in ionic gels by varying the degree of ionization and diminishing the volume-discontinuity at first-order changes. At such a critical point, the first three derivatives of F with respect to V should vanish from Eqs. (2.6) and (2.26). On the other hand, the so-called spinodal point is given by K = 0, at which the volume fluctuations diverges as shown by Eq. (2.10). 

Parameters related to local mobility are more difficult to predict, although there have been significant advances in this field (Ngai, et al. 1986). A complete understanding of these properties, including phenomena such as antiplasticization, will probably require the knowledge of factors such as the spatial free volume fluctuations. 

Elastic Tensor, Volume Fluctuations, and Isotropic Moduli. Rahman and Parrinello [83] showed that the fourth-rank elastic tensor for an anisotropic crystalline solid can be calculated using fluctuations of the microscopic strain tensor ... 

Another MD formulation for constant-temperature and -pressure calculations based on the constant temperature formulation of Nos6 (77) has been described recently. The stochastic collisions which permit energetic fluctuations has been replaced by the dynamic method of scaling of velocities of the atoms, in addition to the scaling of velocities by V1/3. The method, which is completely dynamical, requires one to choose appropriate values for Q and M which respectively determine the time scale of the temperature and volume fluctuations. 

Figures 4.5a-c show the time series of volume V obtained by the conventional isobaric-isothermal MD simulations. The volume fluctuates in narrow ranges. The MUBATH MD simulation, on the other hand, performs a random walk that covers a range of V = 1.8 3.5 nm3, as shown in Fig. 4.5d, which is 3-5 times wider than that by the isobaric-isothermal MD simulations.

In general, the ion-exchange resins synthesized from the isoporous polymers are characterized by high exchange capacity, high permeability for large organic ions, and low volume fluctuations. 

During the long evolution of the enclosed Aral Sea considerable volume fluctuations of the sea level were determined. They had different periodicity geological epochs, centuries, and shorter fluctuations that occurred due to climatic factors. 

To perform MC simulations in the NPT ensemble, we consider a modified version of the model in which we allow for continuous volume fluctuations. To this goal, (i) we assume that the system is homogeneous with all the variables rii set to 1 and all cells have volume v = U//V (ii) we consider... 

In order to implement a constant P ensemble we let the volume fluctuate. A small increment Ar/ro = 0.01 is chosen with uniform random probability and added to the current radius of a cell. The change in volume AV = F " V ... 

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