Energy quenching

Joshua, S., S. Bailey, N. H. Mann, and C. W. Mullineaux (2005). Involvement of phycobilisome diffusion in energy quenching in cyanobacteria. Plant Physiol 138(3) 1577-1585. 

Horton, P. and Ruban, A.V. 1994. The role of light-harvesting complex II in energy quenching. In Photoinhibition of Photosynthesis, eds. N.R. Baker and J.R. Bowyer, pp. 11-128. Oxford BIOS Scientific Publishers Ltd. 

Mullineaux, C.W., Pascal, A.A., Horton, P. and Holzwarth, A.R. 1992. Excitation energy quenching in aggregates of the LHCII chlorophyll-protein complex A time-resolved fluorescence study. Biochim. Biophys. Acta 1141 23-28. 

Yokota, A. Yabuta M. Kanai, W. Kakhiwaga, K. Hijikata, I. Nakane, H. "Plasma Developable Photoresist Containing Electronic Excitation Energy Quenching System," SPE Regional Technical Conference, Ellenville, New York, Nov. 1982. 

We have investigated the photocurrent behavior of multilayers of a Chi a-DPL (molar ratio 1/1) mixture on platinum in an aqueous electrolyte without added redox agents (80). Cathodic photocurrents with quantum efficiencies in the order of 10- were obtained with films consisting of a sufficient number of monolayers. The photocurrent was increased in acidic solutions. However, no appreciable photocurrent was observed with a single monolayer coated on platinum. The latter fact most probably results from minimal rectifying property of the metal surface and/or an efficient energy quenching of dye excited states by free electrons in... 

Free radical quenching by extracts of brown ragi was 94% while that by germinated, fermented and white ragi was 22%, 25%, and 5%, respectively. Extracts from foxtail was equally effective while extracts from rice had a free energy quenching activity of 1.8 (Sripriya et al., 1996). Mehta (2006) extracted ragi flour with methanol and added the dried powder to... 

The time-dependent (non-Markovian) rate constant k(t) determines the rate of energy quenching in the differential kinetic equation that constitutes the basis of this theory ... 

The inverse Laplace transformation of expressions (3.270) provides the kinetics of the energy-quenching N(t) and charge accumulation/separation P(t). The latter ends approaching the free-ion quantum yield... 

Here is the rate constant of the energy quenching during the primary geminate... 

On the contrary, UT is not valid at low concentrations, where it misses the saturation effect. On the other hand, it is better than the two others at high concentrations, where it reproduces the nonlinear increase of r 1 with c, originating from the nonstationary and static energy quenching. Such a superlinearity is usually attributed to the nonlinear corrections to IET available with DET, UT, and a number of other theories (see Section XII) [54,197,198,136]. Fortunately, this effect is very easy to distinguish from the saturation phenomenon at higher concentrations of acceptors their depletion by electron transfer is removed, while the non-linearity related to nonstationary quenching is enhanced. 

There are two parallel channels of energy quenching by either contact formation of exciplex with subsequent dissociation to RIP [Eq. (3.604), scheme I] or by remote formation of RIP with subsequent association (transformation) to exciplex [Eq. (3.604), scheme II]. The last one was considered first by means of unified theory [29], which was extended later to account for both schemes together [30]. Since the results were comprehensively reviewed in Chapter IX of Ref. 32, there is no need to do the same here. It should only be noted that the theory of scheme I has been generalized to account exciplex formation, not only by encounters of excited reactants but also by a straightforward light excitation of existing complexes of the same particles [31]. 

Energy Quenching. In this case xB < xA and there is a limit kBxB - 0 when nothing can be transferred backward to A before B decays. 

Figure 3.85. The Stem—Volmer constant of reversible energy quenching at zB = oo, A -/ . related to its irreversible analog K as a function of backward energy transfer rate constant kb related to the forward one, ka. The thick line is an IET result, while the thin lines are obtained with MET at different concentrations of A 4na3NA/3 = 0.05,0.15,0.3 (from bottom to top). The remaining parameters are 47ia3Afi/3 = 0.15, = 2t(/, and kD

However numerical simulations of early supernova-driven winds fail to find any evidence for substantial gas ejection from luminous ( L ) galaxies. One can ask what is wrong with the hydrodynamic simulations Certainly, the simulations lack adequate resolution. Rayleigh-Taylor instabilities enhance wind porosity and Kelvin-Helmholtz instabilities enhance wind loading of the cold interstellar medium. Both effects are certain to occur and will enhance the wind efficacity. Yet another omission is that one cannot yet resolve the motions of massive stars before they explode. This means that energy quenching is problematic and the current results are inconclusive for typical massive galaxies. 

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