Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Oscillatory behavior for

Ionization potential of metal clusters is one of the factors affected by cluster size [33]. This study represents the most extensive effort so far to determine the size dependence of IP. The measurements on these clusters showed a decreasing IP with size with apparent oscillatory trend. Even-size particles had a relatively larger IP compared to their odd-size counterparts. The data show oscillatory behavior for small Na clusters with a loss of this oscillation for the larger Na clusters. The IP decreases with cluster size, but even at Nai4 the value 3.5 eV is far from... [Pg.79]

Polk model calculated for the case of neutron scattering and with the constituents having the isolated H2O molecule shape and size. The oscillatory behavior for large R, with period 3.7 A, corresponds to the peak in the structure function at 1.7 A-1. [Pg.193]

Figure 2 show the schematic diagram of both heat exchanger and wastewater digester and the interconnection. As was mentioned in previous subsections, if the bioreactor and heat exchanger are separately operated (i.e., uncoupled system), then they do not exhibit oscillatory behavior for the nominal value of the parameter vector and any value of the dilution rate 0 < urr < u < 00. Now, since the bioreactor and the heat exchanger are coupled by the recycle streams and controlled by specific control laws, we need to re-write the models (1) and (3) under recycle and feedback. Figure 2 shows (a) the schematic... [Pg.290]

Figure 10. The calculated total friction (C(0) as a function of time, along with the relative contributions to it from the binary ( and the density relaxation Rpp t) terms for the system CH3 in CH3I. The reduced temperature T (= kaT/e) is 1.158 and the reduced density p for CH3I is 0.918. The time-dependent frictions are scaled by t 2, where = [mirTj/fcgT]1/2 1.1 ps. i and j represent the solute atom and the solvent atom, respectively. The plot shows a clear Gaussian component in the initial time scale for the binary part (r) and slower damped oscillatory behavior for the Rpf t) part. Figure 10. The calculated total friction (C(0) as a function of time, along with the relative contributions to it from the binary ( and the density relaxation Rpp t) terms for the system CH3 in CH3I. The reduced temperature T (= kaT/e) is 1.158 and the reduced density p for CH3I is 0.918. The time-dependent frictions are scaled by t 2, where = [mirTj/fcgT]1/2 1.1 ps. i and j represent the solute atom and the solvent atom, respectively. The plot shows a clear Gaussian component in the initial time scale for the binary part (r) and slower damped oscillatory behavior for the Rpf t) part.
After the series of metabolic pathways had been elucidated for the three model compounds 1-3, these data were implemented into the mathematical model PharmBiosim. The nonlinear system s response to varying ketone exposure was studied. The predicted vanishing of oscillatory behavior for increasing ketone concentration can be used to experimentally test the model assumptions in the reduction of the xenobiotic ketone. To generate such predictions, we employed as a convenient tool the continuation of the nonlinear system s behavior in the control parameters. This strategy is applicable to large systems of coupled, nonlinear, ordinary differential equations and shall together with direct numerical simulations be used to further extend PharmBiosim than was sketched here. This model already allows more detailed predictions of stereoisomer distribution in the products. [Pg.83]

Experiments to measure the electric field and water polarization within 10 A of the surface are difficult to perform. However, recent Molecular Dynamics simulations carried out by Faraudo and Bresme for water between two sodium dodecyl sulfate layers revealed oscillatory behaviors for both the polarization and the electric fields near the surface, and non-proportionality between them [Faraudo, J. Bresme, F. Phys. Rev. Lett. 2004, 92, 236102], Our polari-... [Pg.459]

Recent molecular dynamics simulations of water between two surfactant (sodium dodecyl sulfate) layers, reported by Faraudo and Bresme,14 revealed oscillatory behaviors for both the polarization and the electric fields near a surface and that the two fields are not proportional to each other. While the nonmonotonic behavior again invalidated the Gruen—Marcelja model for the polarization, the nonproportionality suggested that a more complex dielectric response of water might, be at the origin of the hydration force. The latter conclusion was also supported by recent molecular dynamics simulations of Far audo and Bresme, who reported interactions between surfactant surfaces with a nonmonotonic dependence on distance.15... [Pg.487]

A simple model that illustrated the behavior of the polarization when the water molecules are organized in water layers between perfectly flat surfaces was previously suggested.13 That model took into account the nearest-neighbor dipole interactions, but ignored the surface charges and the electrolyte ions. The model is extended here to cases in which an electrolyte as well as surface charges are also present. It will be shown that a treatment of all electrostatic interactions, in the assumption of an icelike structuring of water near interfaces, can predict an oscillatory behavior for both the polarization and the electric potential as well as a nonproportionality between the polarization and the electric fields. [Pg.488]

The requirement that the error is zero at the sampling instants does not preclude large overshoots (Figure 30.3a) or highly oscillatory behavior for the process response (Figure 30.3b). Indeed, as will be explained in the next section, deadbeat controllers suffer from these two weaknesses. [Pg.331]

The Belousov-Zhabotinsky reaction is not the only one which displays oscillatory behavior. For instance the Bray-Liebhafsky reaction discovered in the 1920s by W. C. Bray and H. Liebhafsky is the decomposition of H2C>2 in O2 and H2O with I03 . [Pg.311]

Another way of seeing this important point is shown in Figure 4.8, where we depict (a) the underlying hysteresis loop associated with the species x, (b) the effect of adding the feedback species z, (c) the oscillatory behavior for a particular... [Pg.72]

In a recent publication reviewing the status of research into intrinsic oscillations in solid-catalyzed reactions (l ), we emphasized the potential exploitation of combined theoretical and experimental studies of oscillatory behavior for obtaining new insights into catalytic reaction mechanisms and kinetics. In the present paper, we elaborate further on the subject of formulating and analyzing kinetic models which account for oscillatory behavior, and we present some new experimental information for the oscillatory oxidation of CO on a platinum foil. As in reference 1, the analysis here is applied to models describable by two first-order differential equations. The laboratory data reported were obtained from an isothermal gradientless CSTR of void volume h60 cm3 into which there was inserted a platinum foil of area 200 cm2. Continuous measurements were made of the CO2 concentration in the effluent stream. The experimental system is described in detail elsewhere (, . ... [Pg.487]

Whereas the Belousov-Zhabotinsky reaction with methylmalonic and with ethylmalonic acid shows oscillatory behavior under the conditions that gives oscillatory behavior for malonic acid, no oscillations are observed for benzylmalonic acid under the same conditions (Cavasino et al., 1999). Interestingly, oscillatory behavior was observed for the benzylmalonic acid system after addition of the cationic surfactant cetyltrimethylammonium nitrate. Addition of the surfactant also shortened the induction period for the reactions with methylmalonic and ethylmalonic acid. The oscillation period was affected as well by the surfactant. Pojman et al. (1992) reported that upon addition of acrylonitrile monomer to the reaction mixture of the Belousov-Zhabotinsky reaction, polymerization did not occur continuously, but in a stepwise manner, in phase with the oscillations in the cerium(IV) concentration. The addition of... [Pg.297]

One would be in an ad-hoc fashion to assume that, because of the tendency toward interpenetration, near the crack tips the crack surfaces would come in smooth contact and form a cusp, and the resulting contact region would consist of a single uninterrupted zone rather than the sum of a series of discrete zones as implied by the oscillatory nature of the elastic solution (see Comninou [ll], Atkinson [l2]). Another way is to assume that near the crack tip the linear theory is not valid and to use a large deformation nonlinear theory. An asymptotic analysis using such a theory was provided by Knowles and Sternberg [l3] for the plane stress interface crack problem in two bonded dissimilar incompressible Neo-Hookean materials which shows no oscillatory behavior for stresses or... [Pg.114]


See other pages where Oscillatory behavior for is mentioned: [Pg.347]    [Pg.115]    [Pg.277]    [Pg.521]    [Pg.315]    [Pg.143]    [Pg.175]    [Pg.73]    [Pg.224]    [Pg.60]   
See also in sourсe #XX -- [ Pg.224 ]




SEARCH



Oscillatory

Oscillatory behavior

© 2024 chempedia.info