Spillover channel

The observed shift of the measured bistability region of the Pt/ceria sample compared to the Pt/silica sample can qualitatively be explained by oxygen spillover between ceria and Pt. This can be understood by considering that for Pt/ceria O2 may adsorb on ceria and diffuse to the Pt-ceria boundary and react with CO on the Pt particles, even if the Pt particle is covered by CO. The spillover channel thus extends the gas mixing (/ ) regime, where a high reaction rate can be maintained. The data shown in Fig. 4.33 is particularly... 

A p-type CdTe single crystal wafer 12 is used to seed the epitaxial growth of a p-doped Hgi-xCdjTe spillover layer 14, a p-doped Hgi.yCdyTe absorber layer 16, a p-doped Hgi.zCdzTe transfer layer, and a p-doped Hgi.zCdzTe channel layer 20. A CCD gate structure is formed on... 

We use tubes 100 for determination of plasma levels of intravenously injected 125I-albumin in experiments in which plasma protein accumulation is measured in the same skin sites as inIn-eosinophils (using cross channel correction for the spillover of one isotope into the energy window used to measure the other isotope). Therefore to comply with the tube order programmed into our gamma counter, tubes 100 (or blank positions, when measurement of plasma protein accumulation is not required) are always utilized. 

The simplest, most robust and most widely used technique is presaturation of the solvent [62]. This is simple to implement, may be readily added to existing experiments and leaves (non-exchangeable) resonances away from the presaturation frequency unperturbed. It involves the application of continuous, weak rf irradiation at the solvent frequency prior to excitation and acquisition (Fig. 9.23a), rendering the solvent spins saturated and therefore unobservable (Fig. 9.24). Invariably resonances close to the solvent frequency also experience some loss in intensity, with weaker irradiation leading to less spillover but reduced saturation of the solvent. Longer presaturation periods improve the suppression at the expense of extended experiments so a compromise is required and typically 1-3 s are used trial and error usually represents the best approach to optimisation. Wherever possible the same rf channel should be used for both the presaturation and subsequent proton pulsing, with appropriate transmitter power switching. 

Surface diffusion as a solid-phase process is conceptually similar to those discussed above, except that it involves the movement of heteroatoms rather than carbon atoms. Oxygen and hydrogen are of special interest, because of the widely documented importance of their spillover on the carbon surface. Indeed, the phenomenon of spillover was first observed on the surface of a channel carbon black [238]. 

Day 2 Transfect the cells. Using the polyethyleniinine method, we use a total of 2 ag of DNA per well. Optimal donor and acceptor plasmids quantities should be determined independently (Sections 2.3.1 and 2.3.2). They must always be complemented with empty vector as a DNA carrier to reach 2 ag/well, to equalize transfection efficiency. Always run also a donor-only control transfection, where the energy donor construct is transfected alone, to measure spectral spillover of the donor emission into the acceptor emission channel. Incubate overnight. 

Lichtenberg, Frank, Bruno van Pottelsberghe de la Potterie, 1996, The Channels of International R D Spillovers, Paper prepared for the OECD-Conference on the NEW Indicators for the Knowledge based Economy, 19 -21 June, Paris. 

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