Pulsed studies

Figure 1 shows the series of infrared spectra collected during 02 pulse studies into flowing He/propylene at 250 °C. The initial exposure of the catalyst to the He/propylene flow produced bands at 1982 cm 1 and 1810 cm 1. The band at 1982 cm"1, in the range of adsorbed CO, is a result of interaction of propylene with surface OH. This is evidenced by a decrease in the OH intensity which is accompanied by an increase in the intensity of the 1982 cm"1 band. This 1982 cm"1 band can also be produced from adsorption of PO. The band at 1810 cm"1 is due to CH2 wagging of propylene the band at 1590 and 1465 cm"1 can be... 

A pulse study was performed by adding 16.0 mg of a reactive tracer, A, which has a half-life of 25 s, to an inlet stream flowing at 0.625 L s-1. Determine E(t), t, and of from the following response data ... 

To probe the mechanism the authors carried out pulsing studies, where pulses of CO and H20 were alternated under a flow of helium. Formation of C02 was never observed from CO pulses, but rather C02 and H2 were formed at the same time when H20 was added. Therefore, the authors concluded that the redox mechanism proposed by Bunluesin and coworkers386 could not account for the catalyst behavior, while an associative mechanism, likely via formates, was consistent with the experimental results. 

For the multiple pulse studies, an eight-pulse cycle that has been discussed in detail previously (5,6,16,17,18) was used. Cycle time, tc, the time required for a single eight-pulse cycle, was 42-48 /isec for measurements reported here. 

An accurate determination of the magnetic moment of La and also of the minor isotope La has only very recently (100) been reported, along with the ratio of the quadrupole moments for which Q( La)/Q( La) = 2-15 is calculated from the respective line-widths, assuming quadrupolar relaxation for either isotope. The latter is confirmed on the basis of the relative line-widths in H2O and D2O. In a 0-6 M solution of LaClj in H2O, Av ( La) = 157 Hz or Tj = 2 03 ms, somewhat less than what Reuben (183) reported from pulsed studies (2-73 ms for LaClj, 018m in H2O, 23°C). 

Figure 1. Interaction geometry for two-pulse studies of polarization coherence.

Particle imaging A sheet of double-pulsed Studies of the flow... 

Other workers (Vieux-Rochaz and Chenevas-Paule, 1980 Fuhs and Milleville, 1980 Thompson et al, 1981) have also carried out TSC studies on a-Si H. The results of such studies to date are generally inconsistent with the results of the TSCAP measurements discussed above. A major concern in such measurements in these materials are sources of extraneous currents that obscure the thermal emission phenomena. These include thermal emission over the barrier itself and other kinds of leakage, high sensitivity to surface rather than bulk states, thermoelectric currents, and secondary photocurrent in the case of laser pulse studies. Capacitance measurements are largely insensitive to such effects and are thus more easily interpreted. For these reasons the results of TSC measurements must be carefully checked (for example, by verifying that the features scale properly with applied bias) before they are interpreted in terms of thermal emission from bulk states. 

The long term pulse study was devised to determine the time required for the alkalinity of a solution in the pores of a sand pack to reduce to zero, lliis method provides a means for estimating the Icxigevity of a given volime and concentration of alkaline chen-ical solution injected into an actual petroleum reservoir. 

Figure 9, Schematic comparison long-term pulse study and the field conditions ...

Figure 10. Long-term pulse study. Conditions 1 pore vol of 1% NaOH and 1% NaCl in THUMS Ranger sand pack being displaced in small increments with 1% NaCl solution at 125°F.

Figure IL Long-term pulse study. Conditions for pore vol each A, 0.4% sodium orthosilicate + 1% NaCl O, 0.7% sodium orthosilicate 1% NaCl X, L0% sodium orthosilicate + 7% NaCl and , 2.0% sodium orthosilicate + 1 % NaCl in THU MS Ranger sand packs being displaced in small increments with 1 % NaCl solution at 125 F.

Sexton, L.T., Home, L.P., Sherrill, S.A., Bishop, G.W., Baker, L.A., Martin, C.R. Resistive-pulse studies of proteins and protein/antibody complexes using a conical nanombe sensor. J.Am. Chem. Soc. 129, 13144-13152, 2007. 

Forbes/Reputation Institute 2011 U.S. RepTrak Pulse Study 3M 2011. All rights reserved. 

White and Dry (1989) Ar pulses Studies on gas residence time, tracer detected by two rapid response mass spectrometers, reactor 0.09 m i.d. CFB... 

Batiot-Dupeyrat, C, Valderrama, G., Meneses, A., Martinez, F., Barrault, J., and Tatibouet, J.M. (2003) Pulse study of CO2 reforming of methane over LaNiOa. AppL Catal A, 248, 143-151. 

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