Energy Transfer Based Systems

It should be mentioned that data for energy-transfer-based probes simulated in this chapter are generic and can apply to any D-A system regardless of the decay time of the donor. The optimal modulation frequency will be determined by the decay time, but the magnitude of changes in phase and modulation will depend only on absolute energy transfer efficiency. 

The majority of Os(II) complexes exhibit weak luminescence and might not appear to be attractive candidates for use in various sensing schemes based on luminescence. Systems serving as oxygen sensors, including Os(II) complexes, have recently been reviewed [105]. Nonetheless, there are a few recent examples of applications of this sort and one recent application of a Ru(II)/Os(II) energy transfer based sensing system. 

Meadows DL, Schultz JS. Design, manufacture and characterization of an optical fiber glucose affinity sensor based on an homogeneous fluorescence energy transfer assay system. Analytica Chimica Acta 1993, 280, 21-30. 

QDs have been also used extensively as efficient donors in the development of Forster resonance energy transfer (FRET) systems. The key developments and most recent applications in chemical analysis using such QDs-based strategies are reviewed below. 

Fig. 7 Molecular-level plug/socket system for energy transfer based on the reversible acid-base driven threading-dethreading motions in the hydrogen bonded pseudorotaxane 4d5H+ (CH2C12 room temperature). The acid-driven threading of compound 6, incorporating a bulky benzyl group, through the macrocyclic cavity of 4 does not occur [57]...

The original hot carbonate process developed by the U.S. Bureau of Mines was found to be corrosive to carbon steel (55). Various additives have been used in order to improve the mass transfer rate as well as to inhibit corrosion. Vetrocoke, Carsol, Catacarb, Benfteld, and Lurgi processes are all activated carbonate processes. Improvements in additives and optimization of operation have made activated carbonate processes competitive with activated MDEA and nonaqueous solvent based systems. Typical energy requirements are given in Table 9. 

Computational fluid dynamics (CFD) is the analysis of systems involving fluid flow, energy transfer, and associated phenomena such as combustion and chemical reactions by means of computer-based simulation. CFD codes numerically solve the mass-continuity equation over a specific domain set by the user. The technique is very powerful and covers a wide range of industrial applications. Examples in the field of chemical engineering are ... 

The method of exchange-luminescence [46, 47] is based on the phenomenon of energy transfer from the metastable levels of EEPs to the resonance levels of atoms and molecules of de-exciter. The EEP concentration in this case is evaluated by the intensity of de-exciter luminescence. This technique features sensitivity up to-10 particle/cm, but its application is limited by flow system having a high flow velocity, with which the counterdiffusion phenomenon may be neglected. Moreover, this technique permits EEP concentration to be estimated only at a fixed point of the setup, a factor that interferes much with the survey of heterogeneous processes associated with taking measurements of EEP spatial distribution. 

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