Phenomenological investigation

This paper reports some results of a phenomenological investigation of meditation phenomena and attempts to explain the data and relate them to a broader context. 

Phenomenological investigations of physical and chemical properties related to the strength of emulsion are described in the literature in terms of mechanisms, prop>erties and classes of potential compounds that stabilize emulsions. 

We now consider how one extracts quantitative infonnation about die surface or interface adsorbate coverage from such SHG data. In many circumstances, it is possible to adopt a purely phenomenological approach one calibrates the nonlinear response as a fiinction of surface coverage in a preliminary set of experiments and then makes use of this calibration in subsequent investigations. Such an approach may, for example, be appropriate for studies of adsorption kinetics where the interest lies in die temporal evolution of the surface adsorbate density N. ... 

In the process of establishing the kinetic scheme, the rate studies determine the effects of several possible variables, which may include the temperature, pressure, reactant concentrations, ionic strength, solvent, and surface effects. This part of the kinetic investigation constitutes the phenomenological description of the system. 

Within the broad spectrum of systems described, only few can be considered well understood. Unfortunately, many past investigations were superficial and more involved studies have been avoided because of the inherent complex phenomenology. This has been harmful, and misleading conclusions have been reached about the real potential of furan monomers. It is hoped that this review has shown the fallacy of this approach and will therefore stimulate further skilled work in this field. 

Basic studies on the kinetics of swelling have been performed [1699]. Pure clays (montmoiillonite, illite, and kaolinite) with polymeric inhibitors were investigated, and phenomenologic kinetic laws were established. 

In reaction rate studies one s goal is a phenomenological description of a system in terms of a limited number of empirical constants. Such descriptions permit one to predict the time-dependent behavior of similar systems. In these studies the usual procedure is to try to isolate the effects of the different variables and to investigate each independently. For example, one encloses the reacting system in a thermostat in order to maintain it at a constant temperature. 

Theoretical description of molecular magnets has a history of several decades. The most investigated systems in the past were isotropic or weakly anisotropic magnetic molecules, for which the phenomenological modelling of their magnetic... 

Catalysis is a dynamic process, and deeper insights into its phenomenology are extractable from in situ measurements than from characterizations of catalysts before and after catalysis. A number of notable in situ experiments have relied on modifications of standard TEM operations under vacuum. The main functions of the EM depend on a high-vacuum environment, and the pressure in a TEM is usually of the order of 10-7-10-6 mbar. Because the influence of the reaction environment on the structure and activity of a catalyst is critical (3), the high-vacuum environment of a conventional EM is inappropriate for investigating a catalytic reaction, as are characterizations of catalysts in post-reaction environments (e.g., when the catalyst has been taken out of the reaction environment and cooled to room temperature). 

The critical concentration at which the first micelle forms is called the critical micelle concentration, or CMC. As the concentration of block copolymer chains increases in the solution, more micelles are formed while the concentration of nonassociated chains, called unimers, remains constant and is equal to the value of the CMC. This ideal situation corresponds to a system at thermodynamic equilibrium. However, experimental investigations on the CMC have revealed that its value depends on the method used for its determination. Therefore, it seems more reasonable to define phenomenologically the CMC as the concentration at which a sufficient number of micelles is formed to be detected by a given method [16]. In practical terms, the CMC is often determined from plots of the surface tension as a function of the logarithm of the concentration. The CMC is then defined as the concentration at which the surface tension stops decreasing and reaches a plateau value. 

To elucidate the mechanism of metal UPD, a number of studies on Cu and Ag UPD have been performed over the years comprising phenomenological, CV-based studies and microscopic investigations with STM both ex situ and in situ [38, 39,... 

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