Big Chemical Encyclopedia

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

Articles Figures Tables About

Nonlinear behavior, occurrence

The occurrence of kinetic instabilities as well as oscillatory and even chaotic temporal behavior of a catalytic reaction under steady-state flow conditions can be traced back to the nonlinear character of the differential equations describing the kinetics coupled to transport processes (diffusion and heat conductance). Studies with single crystal surfaces revealed the formation of a large wealth of concentration patterns of the adsorbates on mesoscopic (say pm) length scales which can be studied experimentally by suitable tools and theoretically within the framework of nonlinear dynamics. [31]... [Pg.66]

It is important to introduce the reader at an early stage to simple examples of nonlinear models. We will first present cases with bifurcation behavior as the more general case, followed by special cases without bifurcation. Note that this is deliberately the reverse of the opposite and more common approach. We take this path because it sets the important precedent of studying chemical and biological engineering systems first in light of their much more prevalent multiple steady states rather than from the rarer occurrence of a unique steady state. [Pg.69]

A shortcoming of both models is that they do not capture the occurrence of complex periodic or aperiodic potential oscillations under current control, which were observed in many different electrolytes. Impressive studies of such complicated temporal motions during formic acid oxidation can e.g. be found in Refs. [118, 121], Schmidt et al. [131] suggest that the adsorption of anions, which leads to a competition for free surface sites not only between two species, formic acid and water, but between three species, formic acid, water and anions, can induce complex nonlinear dynamics. This conjecture is derived from differences in the oscillatory behavior found in perchloric and sulfuric acid for otherwise similar conditions. Complex motions were only observed in the presence of sulfuric acid. [Pg.141]

The analytical investigations involved definition of the seismic response of the structure in the nonlinear range of behavior. To model the behavior of the structural system in the elastic phase, at the beginning of nonlinearity (occurrence of cracks) and deep nonlinearity, the IznS three-linear hysteretic model with stiffness degradation and pinching effect was used (Fig. 8.5). [Pg.132]

In this chapter, we present our recent findings related to synchronization in coupled nonlinear oscillator systems with and without time delay as specific representation of certain neuronal behaviors. In the following section, we discuss about the ubiquitous nature of synchronization in dynamical systems. In Section 3, we explain the structure of neurons and how neurons function as a collective system. Section 4 is dedicated to the discussion of the occurrence of oscillations and synchronization in neuronal networks. In Section 5, we demonstrate the occurrence of event related desynchronization in a system of coupled nonlinear oscillators in the presence of an external field. In Section 6, we discuss the effect of time delay in coupled populations of nonlinear oscillators and demonstrate the occurrence of globally clustered chimera (GCC) states. In Section 7, we present a demand controlled delayed feedback mechanism for controlling the occurrence of mass pathological synchronization in the brain. Finally, in Section 8, we present our conclusions and summarize the chapter. [Pg.80]

The existence or nonexistence of mirror symmetry plays an important role in nature. The lack of mirror symmetry, called chirality, can be found in systems of all length scales, from elementary particles to macroscopic systems. Due to the collective behavior of the molecules in liquid crystals, molecular chirality has a particularly remarkable influence on the macroscopic physical properties of these systems. Probably, even the flrst observations of thermotropic liquid crystals by Planer (1861) and Reinitzer (1888) were due to the conspicuous selective reflection of the helical structure that occurs in chiral liquid crystals. Many physical properties of liquid crystals depend on chirality, e.g., certain linear and nonlinear optical properties, the occurrence of ferro-, ferri-, antiferro- and piezo-electric behavior, the electroclinic effect, and even the appearance of new phases. In addition, the majority of optical applications of liquid crystals is due to chiral structures, namely the ther-mochromic effect of cholesteric liquid crystals, the rotation of the plane of polarization in twisted nematic liquid crystal displays, and the ferroelectric and antiferroelectric switching of smectic liquid crystals. [Pg.511]

For one, realism means incorporating all pertinent sources of material and geometric nonlinearity that are expected to arise. This should include, for example, plastic-hinge formation zones for moment-resisting frames, brace buckling for braced frames, and P-Delta effects. Nonsimulated failure modes, such as the shear failure of members or the brittle failure of beam-column joints, can be incorporated in the analysis a posteriori. Still, they essentially remove the model s ability to track structural behavior beyond their first occurrence. This means that whenever nonsimulated failures are found to have occurred, one cannot trust the model to provide estimates beyond that point. [Pg.1166]


See other pages where Nonlinear behavior, occurrence is mentioned: [Pg.176]    [Pg.2995]    [Pg.331]    [Pg.825]    [Pg.283]    [Pg.251]    [Pg.570]    [Pg.45]    [Pg.23]    [Pg.255]    [Pg.331]    [Pg.255]    [Pg.452]    [Pg.102]    [Pg.23]    [Pg.34]    [Pg.661]    [Pg.103]    [Pg.71]    [Pg.43]    [Pg.21]    [Pg.7]    [Pg.146]    [Pg.784]    [Pg.3167]    [Pg.421]   
See also in sourсe #XX -- [ Pg.2 ]




SEARCH



Nonlinear behavior

© 2024 chempedia.info