Functional Dyes by Application

Over the past 30 or 40 years many technologies have attempted to take a share of the imaging market, particularly that for nonimpact printing [1], Of these technologies, two now dominate, namely, laser printers and especially ink-jet printers, although thermal printers are also used, particularly in color printing. 

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Decolorization of azo dyes by WRF technology improvements will require integration of all major areas of industrial biotechnology novel enzymes and microorganisms, functional genomics, protein engineering, biomaterial development, bioprocess design and applications. 

In this section, we present the most important molecular families that have been designed by various groups in order to fulfill these requirements. We will group the materials in different classes by symmetry according to their molecular core. A variety of functional dyes have been linked to each of the cores, the properties and applications of which will be discussed in Section IV. 

Experimental Setup. An obvious extension of the one-color pump-probe experiments is the application of two-color experiments in which two independently tunable dye lasers share the same pump laser. One can use the same high repetition rate and obtain spectral evolutions on excitation at selected wavelengths. The measurements are performed in essentially the same way as one-color experiments.A disadvantage is the broadened instrument function (cross-correlation function) caused by time jitter between the two pulses, since they are not obtained from the same dye laser. This leads to a full-width half-maximum (fwhm) value of the instrument function of approximately 5-10 psec. 

Visualization has played a central role in the development of the field of microfluidics and associated applications. It is both a natural desire and highly informative to see what is going on inside these small-scale systems. The inherent scale of these systems results in significant deviations from macroscale fluid behavior, most notably due to an increase in the role of surface effects and diffusive transport of mass, momentum, and energy. Unique micro- and nanoscale transport phenomena present many opportunities for advanced functionality as exploited by the many applications described in this encyclopedia and elsewhere. The scale of these systems, however, also presents some unique challenges with respect to visualization. Most notably, on the microscale the nonintrusive requirement precludes the use of many techniques commonly applied to macroscale flows, such as hot-wire anemometry and the injection of dye by mechanical means. In addition, it is not possible to observe the phenomena without the use of a microscope. Several visualization techniques have, however, been successfully applied to microscale flows. Like much of the research in microfluidics and nanofluidics, many proof-of-concept contributions have appeared in the 1990s, and subsequent advancement has been rapid. Most visualization techniques applied to microstructures may be conveniently divided into two categories particle-based methods and scalar-based methods [1]. 

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