Desorption and

DIET Desorption induced by electronic transitions [147a] General class of desorption and reaction phenomena induced by electron or photon bombardment Same as ESD and PSD... [Pg.315]

A more elaborate theoretical approach develops the concept of surface molecular orbitals and proceeds to evaluate various overlap integrals [119]. Calculations for hydrogen on Pt( 111) planes were consistent with flash desorption and LEED data. In general, the greatly increased availability of LEED structures for chemisorbed films has allowed correspondingly detailed theoretical interpretations, as, for example, of the commonly observed (C2 x 2) structure [120] (note also Ref. 121). [Pg.704]

Fig. XVIII-13. Activation energies of adsorption and desorption and heat of chemisorption for nitrogen on a single promoted, intensively reduced iron catalyst Q is calculated from Q = Edes - ads- (From Ref. 130.)...

If adsorption occurs via a physisorbed precursor, then the sticking probability at low coverages will be enhanced due to the ability of the precursor to diflfiise and find a lattice site [30]. The details depend on parameters such as strength of the lateral interactions between the adsorbates and the relative rates of desorption and reaction of the precursor. In figure Al.7,8 an example of a plot of S versus 0 for precursor mediated adsorption is presented. [Pg.298]

Bonn M, Funk S, Hess C, Denzier D N, Stampfl C, Soheffler M, Wolf M and ErtI G 1999 Phonon versus eleotron-mediated desorption and oxidation of CO on Ru(OOI) Science 285 1042... [Pg.920]

TPD Temperature programmed desorption After pre-adsorption of gases on a surface, the desorption and/or reaction products are measured while the temperature Increases linearly with time. Coverages, kinetic parameters, reaction mechanism... [Pg.1852]

Favorable and unfavorable equihbrium isotherms are normally defined, as in Figure 11, with respect to an increase in sorbate concentration. This is, of course, appropriate for an adsorption process, but if one is considering regeneration of a saturated column (desorption), the situation is reversed. An isotherm which is favorable for adsorption is unfavorable for desorption and vice versa. In most adsorption processes the adsorbent is selected to provide a favorable adsorption isotherm, so the adsorption step shows constant pattern behavior and proportionate pattern behavior is encountered in the desorption step. [Pg.263]

During Stages II and III the average concentration of radicals within the particle determines the rate of polymerization. To solve for n, the fate of a given radical was balanced across the possible adsorption, desorption, and termination events. Initially a solution was provided for three physically limiting cases. Subsequentiy, n was solved for expHcitiy without limitation using a generating function to solve the Smith-Ewart recursion formula (29). This analysis for the case of very slow rates of radical desorption was improved on (30), and later radical readsorption was accounted for and the Smith-Ewart recursion formula solved via the method of continuous fractions (31). [Pg.24]

VACUUM RADIATING DESORPTION AND INFRARED SPECTROMETRY (VRDIR) FOR CONTINUOUS MONITORING OF SUSPENDED PARTICULATE ORGANIC MATTERS IN ATMOSPHERE... [Pg.173]

LIMS is primarily used in failure microanalysis applications, which make use of its survey capability, and its high sensitivity toward essentially all elements in the periodic table. The ability to provide organic molecular information on a microanalyt-ical scale is another distinctive feature of LIMS, one that is likely to become more important in the future, with improved knowledge of laser desorption and ionization mechanisms. [Pg.596]

The situation changes when the system pressure becomes high enough for refrigerant to condense in the condenser and reject the resulting latent heat to the environment. Further addition of heat to the adsorbate desorbs more refrigerant which condenses in the condenser and trickles down into the receiver. The system pressure stays approximately constant as desorption and condensation proceed. [Pg.310]

Lab method using porous polymer adsorption tube and thermal desorption with gas chromatography Lab method using porous polymer diffusive samplers with thermal desorption and gas chromatography Lab method using pumped acid-coated filters, desorption and liquid chromatography... [Pg.360]

Charcoal adsorbent tubes with solvent desorption and gas chromatography... [Pg.360]

Chlorinated hydrocarbon solvent vapours in air Lab method using pumped charcoal adsorption tubes, solvent desorption and gas chromatography 28... [Pg.361]

Diethyl sulphate and dimethyl sulphate Lab method using Tenax sorbent tube, thermal desorption and gas chromatography with mass spectrometry 89... [Pg.361]

Ethylene dibromide Lab method with pumped Tenax absorbent tubes, solvent desorption and electron capture gas chromatography 45... [Pg.361]

Eormaldehyde in air Lab method using diffusive sampler, solvent desorption and high performance liquid chromatography 78... [Pg.361]

Hydrocarbons (mixed C3-C,q) Lab method using pumped porous polymer and carbon sorbent tubes, thermal desorption and gas chromatography 60... [Pg.361]

Lab method using charcoal diffusive samplers, solvent desorption and gas chromatography (using Drager ORSA monitor) 64... [Pg.363]

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