Big Chemical Encyclopedia

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

Articles Figures Tables About

Complex phenomena

The surface tension of a pure liquid should and does come out to be the same irrespective of the method used, although difficulties in the mathematical treatment of complex phenomena can lead to apparent discrepancies. In the case of solutions, however, dynamic methods, including detachment ones, often tend... [Pg.35]

Losses are complex phenomena and as discussed here are a function of many factors, including inlet conditions, pressure ratios, blade angles, and flow. Figure 6-35 shows the losses distributed in a typical centrifugal stage of pressure ratio below 2 1 with backward-curved blades. This figure is only a guideline. [Pg.254]

The continued pursuit of semi-empirical methods for the prediction of adhesion is a worthy, if somewhat risky, enterprise. It may well lead to improved and more streamlined methods of finding new materials and methods, but lacking that, even its failures, if honestly evaluated, should lead to improved understanding of the complex phenomena of adhesion. [Pg.68]

Iaml92] Lam, L. and V. Naroditsky, editors. Modeling Complex Phenomena Proceedings of the Third Woodward Conference, San Jose State University, April 12-13, 1991, Springer-Verlag (1992). [Pg.770]

Solvation and especially hydration are rather complex phenomena and little is known about them. Depending on the kind of molecular groups, atoms or ions interacting with the solvent, one can differ between lyo- or hydrophilic and lyo-or hydrophobic solvation or hydration. Due to these interactions the so-called liquid structure is changed. Therefore it seems to be unavoidable to consider, at least very briefly, the intermolecular interactions and the main features of liquids, especially water structure before dealing with solvation/hydration and their effects on the formation of ordered structures in the colloidal systems mentioned above. [Pg.2]

A complex phenomena that promotes the use of fat for energy (a positive effect) and permits fat stores to accumulate in the body, causing buffalo hump and moon- or round-shaped face (a negative effect). [Pg.522]

Note that the concentrations of additive oxides differ. No attempt has been made to scale this effect with additive concentration). This curious reduction effect is not easily understood but emphasizes the complex nature of the glasses including the possible cooperative involvement of the multiple components. Similarly complex phenomena might influence leaching behavior in the complex, multicomponent glasses of interest for radioactive waste storage. [Pg.153]

The subject of the book is fluid dynamics and heat transfer in micro-channels. This problem is important for understanding the complex phenomena associated with single- and two-phase flows in heated micro-channels. [Pg.486]

Since electrochemical processes involve coupled complex phenomena, their behavior is complex. Mathematical modeling of such processes improves our scientific understanding of them and provides a basis for design scale-up and optimization. The validity and utility of such large-scale models is expected to improve as physically correct descriptions of elementary processes are used. [Pg.174]

To discover and analyze the mathematical basis for the generation of complexity, one must identify simple mathematical systems that capture the essence of the process. Cellular automata are a candidate class of such systems. Cellular automata promise to provide mathematical models for a wide variety of complex phenomena, from turbulence in fluids to patterns in biological growth. [Pg.9]

More complex phenomena occur when current crosses interfaces between semiconductors. The most typical example is the rectification produced at interfaces between p- and n-type semiconductors. Electric current freely flows from the former into the latter semiconductor, but an electric field repelling the free carriers from the junction arises when the attempt is made to pass current in the opposite direction Holes are sent back into the p-phase, and electrons are sent back into the n-phase. As a result, the layers adjoining the interface are depleted of free charges, their conductivities drop drastically, and current flow ceases ( blocking the interface). [Pg.13]

Ion-selective membranes derive their permselective properties from either ion exchange, solubility or complexation phenomena. Current ion-selective electrodes contain membranes which consist of glass, solid or liquid phases. [Pg.58]

The basic model has already been extended to treat more complex phenomena such as phase separating and immiscible mixtures. These developments are still at an early stage, both in terms of the theoretical underpinnings of the models and the applications that can be considered. Further research along such lines will provide even more powerful mesoscopic simulation tools for the study of complex systems. [Pg.139]

In summary, a great deal of reasearch is yet to be conducted to describe these complex phenomena. [Pg.121]

The polymerization sites at the molecule s exterior are likely to experience more fruitful collisions than sites on the interior. To account for such complex phenomena, an additional separable function was introduced to simulate steric hindrance factors at the molecular level. An arbitrary, but continuous, exponential function was selected. The resulting rate constant that yields a good fit of experimental population density distributions is... [Pg.285]

Despite the increasing interest in understanding the phenomena of bonding in silicon compounds, there are, until now, no well established and commonly accepted theories. Silicon compounds are mainly discussed in terms of carbon chemistry. Thus, specific properties of silicon compounds are usually compared with those of the corresponding carbon homologues. In this report some important features of silicon compounds are developed by means of ab initio calculations. From this a set of basic rules will be presented by which more complex phenomena can be explained in turn. [Pg.81]

To establish this, Bernard starts with the idea of complexity and mobility, fugacity or transience of living phenomena. Complexity, he explains, is not such a great obstacle. It can be dealt with by the method of experimental analysis which decomposes successively all complex phenomena into simpler and simpler phenomena, until their reduction to only two elementary conditions, if possible (Bernard, 1966, p. 114). Why two conditions This idea of two conditions is very striking. The first meaning of condition is... [Pg.38]

Proceeding along a parallel track, Guillory and coworkers used DTA analysis to study complexation phenomena [2]. Through the performance of carefully designed studies, they were able to prove the existence of association complexes and deduced the stoichiometries of these. In this particular work, phase diagrams were developed for 2 1 deoxycholic acid-menadione, 1 1 quinine-phenobarbital, 2 1 theophylline-phenobarbital, 1 1 caffeine-phenobar-bital, and 1 1 atropine-phenobarbital. The method was also used to prove that no complexes were formed between phenobarbital and aspirin, phenacetin, diphenylhydantoin, and acetaminophen. [Pg.230]

The computation of formation constants is considered to be the most important aspect of equilibrium theory, since this knowledge permits a full specification of the complexation phenomena. Once this information is in hand, the formulator can literally define the system at a given temperature through the manipulation of solution-phase parameters to obtain the required drug solubility. [Pg.343]

Metal ions play an important role as catalysts in many autoxidation reactions and have been considered instrumental in regulating natural as well as industrial processes. In these reactive systems, in particular when the reactions occur under environmental or in vivo biochemical conditions, the metal ions are involved in complicated interactions with the substrate(s) and dioxygen, and the properties of the actual matrix as well as the transport processes also have a pronounced impact on the overall reactions. In most cases, handling and analyzing such a complexity is beyond the capacity of currently available experimental, computational and theoretical methods, and researchers in this field are obliged to use simplified sub-systems to mimic the complex phenomena. When the simplified conditions are properly chosen, these studies provide surprisingly accurate predictions for the real systems. In this paper we review the results obtained in kinetic and mechanistic studies on the model systems, but we do not discuss their broad biological or environmental implications. [Pg.396]

Scale-up of gas atomizers is difficult and it requires the use of higher gas-to-melt mass flow rate ratio to maintain the same droplet size. The scale-up may also cause some complex phenomena to occur, such as the disappearance of the prefilming effect in close-coupled atomizers, the generation of turbulence in melt flow within delivery nozzle, and change in atomization mechanisms. [Pg.87]


See other pages where Complex phenomena is mentioned: [Pg.8]    [Pg.350]    [Pg.170]    [Pg.8]    [Pg.740]    [Pg.839]    [Pg.153]    [Pg.273]    [Pg.278]    [Pg.94]    [Pg.10]    [Pg.133]    [Pg.90]    [Pg.731]    [Pg.544]    [Pg.105]    [Pg.230]    [Pg.701]    [Pg.39]    [Pg.43]    [Pg.203]    [Pg.234]    [Pg.242]    [Pg.254]    [Pg.338]    [Pg.76]    [Pg.477]    [Pg.5]    [Pg.148]   
See also in sourсe #XX -- [ Pg.5 ]

See also in sourсe #XX -- [ Pg.221 ]




SEARCH



Complex binding phenomena

Complex mass transfer phenomena

Complex non-equilibrium phenomena

Complex oscillatory phenomena in a three-variable model for cAMP signalling

Complexation phenomena

Cooperative Phenomena in Complexation Processes

Exciplexes, Electron Donor-Acceptor Complexes, and Related Charge-transfer Phenomena

More Complex Phenomena

Redox Phenomena, Complexation, and Precipitation

Spin Crossover Phenomena in Fe(II) Complexes

Surface complexation phenomena related

© 2024 chempedia.info