Mode regenerative

Bade P, Bourvier M and Coe J S 1987 Nd YLF mode-locked oscillator and regenerative amplifier Opt. Lett. 12 319-21... 

A regenerative fuel cell system can also be a single electrochemical cell in which both the oxidation of fuels (i.e., production of electric power) and reduction of CO2 (to obtain fuels) can be carried out by simply reversing the mode of operation. 

Adsorbent drying systems are typicaHy operated in a regenerative mode with an adsorption half-cycle to remove water from the process stream and a desorption half-cycle to remove water from the adsorbent and to prepare it for another adsorption half-cycle (8,30,31). UsuaHy, two beds are employed to aHow for continuous processing. In most cases, some residual water remains on the adsorbent after the desorption half-cycle because complete removal is not economically practical. The difference between the amount of water removed during the adsorption and desorption half-cycle is termed the differential loading, which is the working capacity available for dehydration. 

When eontrolling an a.e. maehine, the eonverter is usually a full-wave, power diode fixed-type reetifier and the Vlf is eontrolled through the IGBT inverter. For regenerative mode, the d.e. bus is eonneeted in antiparallel with a full-wave voltage-eontrolled inverter as shown in Figure 6.31. 

The pay-off roll is unwound by the tension of the sheet, caused by the speed of the recoiler at the finishing line and the bridles positioned at different locations. The pay-off roll motors therefore operate in a regenerative mode and can feed-back the energy thus saved to the source of supply, if desired. This can be done by using a full-wave synchronous inverter, as shown in Figures 6.31 or 6.33. 

The power train consists of an HP and LP expander arranged in series that drives the motor/generator, which in this mode is declutched from the compressor train and is connected by clutch to the HP and LP expander train. The HP expander receives air from the cavern that is regeneratively heated in a recuperator utilizing exhaust gas from the LP expander, and then further combusted in combustors before entering the HP expander. The... 

Operational Modes The Catalytic Recuperative Oxidizer assumes a 65% efficienct heat exchanger. The Thermal Recuperative Oxidizer assumes a 65% efficienct heat exchanger The Regenerative Catalytic Oxidizer assumes a 95% efficienct heat exchanger The Regenerative Thermal Oxidizer assumes a 95% efficient heat exchanger. The rotor concentrator wheel assumes a 6 1 concentration ratio. 

Figure 226. Concept of a zero C02 emission vehicle using a thermally regenerative reformer (a) conventional reforming, (b) proposed thermally regenerative reforming, (b-1) reforming mode, (b-2) regenerating and C02 recovering mode [6]...

The photovoltaic effect is initiated by light absorption in the electrode material. This is practically important only with semiconductor electrodes, where the photogenerated, excited electrons or holes may, under certain conditions, react with electrolyte redox systems. The photoredox reaction at the illuminated semiconductor thus drives the complementary (dark) reaction at the counterelectrode, which again may (but need not) regenerate the reactant consumed at the photoelectrode. The regenerative mode of operation is, according to the IUPAC recommendation, denoted as photovoltaic cell and the second one as photoelectrolytic cell . Alternative classification and terms will be discussed below. 

The oxygen cathode—for which platinum catalyst due to its outstanding structural and catalytic capability is the rule—is not used as an oxygen evolution anode in the electrolyzer operation mode because oxidation of Pt and fast catalyst deterioration would be the consequence. Therefore an oxygen cathode based on a platinum catalyst must operate as a -evolving cathode in the regenerative mode. 

The oxygen anode (in the regenerative mode) as a metal oxide is also able to work in the oxidic form as hydrogen anode (in the fuel cell mode). 

The conversion of toluene to benzene was studied by Steenhof de Jong et al. (302—304), by both pulse and flow experiments. In the absence of oxygen, selectivities of up to 70% are obtained with bismuth uranate catalysts at 400—500° C. The best catalyst is Bi2U06. The catalyst is reduced in the oxidation process, as gas phase oxygen is absent. The reduction proceeds to metallic bismuth and U02. The activity decreases during reduction, but is completely restored by reoxidation with air. Therefore, a regenerative mode of operation is proposed for practical application of this process. 

Figure 1. Combined energy diagram for a regenerative photoelectrochemical cell with n-CdSe as the anode, metallic cathode and polysulfide as the electrolyte. The diagram indicates some of the charge accumulation modes that might contribute to the potential distribution at the interface. ((Qn) ionized donors (Qdt) deep traps ...

Watanabe and Regen 81 reported the construction of ordered, dendritic multilayers (10) via a bridged, outer sphere —outer sphere mode of assembly (Figure 9.5) whereby the transition metal Pt was used as a connector moiety. Although amine-terminated PAMAM-type dendrimers 76 were employed for this particular example, this process could easily be extended to other types of macromolecules. 

In the asymmetric mode of operation the endothermic and exothermic reactions take place separately either in different compartments (recuperative mode) or at different time intervals (regenerative mode). The attractiveness of the asymmetric mode is related to the fact that the separation of the process streams allows an individual tuning of the operating conditions for the endothermic and the exothermic subsystem. 

There are 4-quadrant and 2-quadrant converters. 4-quadrant converters have two controlled rectifier bridges, one of which serves to operate the drive mode while the other operates the generating mode. Since no great moments of inertia arise in extruder operation, there are no great moments of inertia that would cause regenerative braking, only 2-quadrant converters... 

---