Electron pumping

Increasing numbers of advanced batteries for all purposes depend on ionically conducting solid electrolytes, so it will be helpful to discuss these before continuing. It should be remembered that any battery can be described as an electron pump, and the role of the electrolyte is to block the passage of electrons, letting ions through instead. 

The battery acts as an electron pump, pushing electrons into the cathode, C, and removing diem from the anode, A. To maintain electrical neutrality, some process within the cell must consume electrons at C and liberate them at A. This process is an oxidation-reduction reaction when carried out in an electrolytic cell, it is called electrolysis. At the cathode, an ion or molecule undergoes reduction by accepting electrons. At the anode, electrons are produced by the oxidation of an ion or molecule. 

Photosynthetic reaction centers from Rhodobacter sphaeroides and bacteri-orhodopsin (BR) from purple membrane (PM) have been used for their unique optoelectronic properties and for their capability of providing light-induced proton and electron pumping. Once assembled they display extremely high thermal and temporal stability... 

The increase in the values of aliphatic amines (thus making them stronger bases as compared to ammonia) is due to the electron-releasing nature of alkyl groups. This release of electrons pumps electron density back to the nitrogen atom, which stabilizes the positive charge. 

Noise and Drift. Electronic, pump, and photometric noise poor lamp intensity, a dirty flow cell, and thermal instability contribute to the overall noise and drift in the detector. Excessive noise can reduce the sensitivity of the detector and hence affect the quantitation of low-level analytes [13,14]. The precision of the... 

One of the most important DSSC component is the dye sensitizer that represents the electron pump of the device. It allows an independent electron injection into the semiconductor conduction band and conversion of visible and near-infrared (NIR) photons to electricity. 

Figure 4. Schematic for the photoelectrochemical simulation of the photosynthetic electron-pumping processes ("upper sketch by means of a Chl-semiconductor photoanode and a Chl-metal photocathode...

Electron-cation symport has been realized in a double carrier process where the coupled, parallel transport of electrons and metal cations was mediated simultaneously by an electron carrier and by a selective cation carrier [6.47]. The transport of electrons by a nickel complex in a redox gradient was the electron pump for driving the selective transport of K+ ions by a macrocyclic polyether (Fig. 12). The pro-... 

An electrolytic cell has two electrodes that dip into an electrolyte and are connected to a battery or some other source of direct electric current. A cell for electrolysis of molten sodium chloride, for example, is illustrated in Figure 18.15. The battery serves as an electron pump, pushing electrons into one electrode and pulling them out of the other. The negative electrode attracts Na+ cations, which combine with the electrons supplied by the battery and are thereby reduced to liquid sodium metal. Similarly, the positive electrode attracts Cl- anions, which replenish the electrons removed by the battery and are thereby oxidized to chlorine gas. The electrode reactions and overall cell reaction are... 

Fig. 2 An example of schematic diagram of high-pressure apparatus. A Heater B doublewall pressure vessel C hand pump or electronic pump D oil reservoir E valve F intensi-fler G gauge H flexible sample container...

The electrons pumped into the corrodible metal have come, in the above method, from the dissolution of a scarificial auxiliary metal. Instead, they can come from an external current source (i.e., an electrical power supply). The electrical circuit, however, has to be completed, and toward this end, an auxiliary inert electrode can be immersed in the corrosive electrolyte to provide a return path for the electron current (Fig. 12.38). The external source can then be adjusted so that the potential difference between the corrodible metal and its environment becomes negative with respect to its equilibrium potential. Under these circumstances, the whole of the metal to be protected against corrosion will function as an electron source for the electronation reaction, and the second electrode will serve as an electron sink for some deelectronation reaction (Hoar). 

The redox system does not depend on endosomal acidification but needs TfR. Fe2Tf first binds to TfR which is located in close proximity to the proton-and electron-pumping NADHiTf oxidoreductase. The Fe—Tf bond is destabilized by proton efflux, making Fe3+ susceptible to reduction. Fe2+ is trapped by a plasma membrane binder and can be transported by a translocator [4]. As Al is a simple trivalent cation incapable of redox changes, it may be theoretically impossible that Al bound to Tf is taken up by a redox mechanism. Actually, no reports on a redox-mediated process of Al bound to Tf have been made. 

Figure 7 Proton NMR signal enhancement as a function of the electronic pumping frequency for trans-rich (solid circle), and cw-rich (solid square) poly acetylene samples.

Stefanucd G, Kurth S, Rubio A, Gross EKU (2008) Time-dependent approach to electron pumping in open quantum systems. Phys Rev B 77(7) 075339... 

The importance of metals in catalysis the role of metals as electron pumps . 

The need for a separate hot electron emitter is therefore eliminated. The electronic pumping speed of this gauge is high (1 liter/sec for N2) and cannot be adjusted. Its use in gas-filled systems is therefore limited, especially since this gauge cannot be readily keyed. The high rate of clean-up does make it quite suitable as a pump, however. 

An electrolytic cell consists of two electrodes immersed either in a molten salt or in a solution. A battery or some other source of electrical energy acts as an electron pump, pushing electrons into one electrode and pulling them from the other. Just as in voltaic cells, the electrode at which reduction occurs is called the cathode, and the electrode at which oxidation occurs is called the anode. 

Pump dosage rate is low Verify that the electronic pump controller is functioning at the desired rate. Verify pump speed and stroke length Check the operation of the flow switch and the set-point value... 

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