Through-field plate electrode

The through-field plate electrode system is configured as two flat metal plates between which the processed material is located. The electrodes can be in contact with the load (sometimes under pressure or vacuum), or an air gap exists, which is the case in a conveyor-type apparatus. 

By external stimulus at the plate electrode, migration of the ions in the solvent is induced, which changes the spatial concentration and so the local course of reactions [68]. By this means, weak electrical fields change the propagation velocity of the reaction zone through the capillary strong electrical fields ( supercritical ) further affect the global feature of the reaction in the capillary. 

One of the key components in the system is the mass spectrometer. Fragments are ionized by a VUV laser pulse between a pair of plane parallel-plate electrodes (6 x 14 cm). One of the plane electrodes has a slit of 1 x 10 cm, which is covered by a metal mesh. The slit is parallel to the VUV laser beam and is the entrance of the mass spectrometer. Ions are accelerated by a pulsed electric field present between the plane parallel-plate electrodes, and then pass through the slit before they enter the mass spectrometer. 

Plasma polymerization is usually carried out in a low pressure glow discharge sustained by either a dc or an ac electric field. Examples of the reactors used for this purpose are shown in Fig. 1. The simplest configuration involves a pair of circular parallel plate electrodes mounted inside a glass bell jar. The lower electrode usually serves as the substrate holder and is sometimes heated or cooled. Monomer is introduced through a feed tube and unconsumed monomer and gaseous products are withdrawn through a port in the base plate. 

Consider a plane-parallel condenser of capacitance C whose plates are a p-type semiconductor (e.g., a CP) and a metal, and polarize the latter negatively. Excess positive charges (i.e., holes) appear at the surface of the semiconductor, and since its conductivity is low, they are in fact distributed over a certain thickness within the material. These excess holes, or at least part of them, should take part in the conduction. Applying a voltage to an external electrode not in contact with the semiconductor modulates its conductivity. This is the principle of the field effect, and clearly this control of the current through a gate electrode opens the possibility of transistor action without requiring the existence of p-n junctions. 

TSM resonator, also known as quartz crystal microbalance (QCM), is the simplest and most widespread acoustic wave device today. TSM typically composes of a quartz plate sandwiched by electrodes on opposite faces. Electric field crosses through this plate when voltage is applied to the electrodes, resulting in a shear mechanical strain or displacement in the quartz. By oscillating the voltage frequency, a mechanical resonance can be generated, where the maximum displacement of crystal occurs at the surfaces. The resonant frequency, F, and the quality factor, Q, are the two resonance parameters. While Ej. is the mechanical thickness shear resonance as mentioned before, it is also defined as the frequency of the maximum value of the electrical conductance, Gei- Q is approximated mathematically from the electrical conductance resonance spectrum as 2 = Er/AEnw- or the ratio of resonant frequency to the half bandwidth [5]. 

Atomic and molecular species identification via motional resonance-based detection is also possible in more complex systems, namely in large multispecies ion crystals of various size, shape, and symmetry [47,52,70] (Figure 18.19). The basic principle of the method is as follows. The radial motion of the ions in the trap is excited using an oscillating electric field of variable frequency applied either to an external plate electrode or to the central trap electrodes. When the excitation field is resonant with the oscillation mode of one species in the crystal, energy is pumped into the motion of that species. Some of this energy is distributed through the crystal, via the Coulomb interaction. This, in turn, leads to an increased temperature of the atomic coolants and modifies their fluorescence intensity, which can be detected. 

Schematic of the bipolar plate with serpentine flow channel (a) flow field layout and (b) the cross-sectional view of the bipolar plate and the porous electrode along the line A-A illustrating the cross-leakage flow between the two adjacent flow channels through the porous electrode structure as presented by the thick arrow. (From Kanezaki, T. et ak, 2006. Journal of Power Sources, 162 415-425. With permission.)...

A current collector is a plate attached to a flow field plate or bipolar plate to collect the current generated by fuel cell reactions. Sometimes, metal flow field plates/bipolar plates can also serve as current collectors in a single PEM fuel cell or a stack. The electrons generated by the HOR at the anode must be conducted through the anodic electrode and current collector and must then... 

In PEMFCs, electrode layers are the place where electrochemical reactions take place, made up of catalyst and GDL. At the anode, the hydrogen is broken into protons and electrons. The electrons firstly travel to the carbon cloth, flow field plate followed by the contact, and then to the load. The protons travel through the polymer exchange membrane to the cathode. At the cathode catalyst layer, oxygen combines with protons and electrons, and then water is produced. The catalyst layer must get very effective when breaking molecules into protons and electrons with large... 

Wlien an electrical coimection is made between two metal surfaces, a contact potential difference arises from the transfer of electrons from the metal of lower work function to the second metal until their Femii levels line up. The difference in contact potential between the two metals is just equal to the difference in their respective work fiinctions. In the absence of an applied emf, there is electric field between two parallel metal plates arranged as a capacitor. If a potential is applied, the field can be eliminated and at this point tire potential equals the contact potential difference of tlie two metal plates. If one plate of known work fiinction is used as a reference electrode, the work function of the second plate can be detennined by measuring tliis applied potential between the plates [ ]. One can detemiine the zero-electric-field condition between the two parallel plates by measuring directly the tendency for charge to flow through the external circuit. This is called the static capacitor method [59]. 

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