Electric charge field

Fig. 6.21 Profiles of charge, electric field, and potential distribution through the gate of an ion-sensitive field-effect transistor (ISFET)...

Flame ionization detectors (FIDs) and photoionization detectors (PIDs) can be used for the detection of hydrocarbons. Both detectors have been utilized for combustibles monitoring in portable and fixed installation designs. The FID actually burns the sample in an H2 flame. A charged electrical field is positioned across the flame, and utilizing the ions in the flame can conduct a current. When most combustible materials are introduced into the flame, they produce ions in their combustion products, and these are detected by the increased flow of current across the electric field (flame). 

The electro-optic effect leads to the modification of the refractive index of a suitable material when an electric field is applied (Figure 8). The electro-optic effect must be present in a photorefractive material, so that the space charge electric field pattern due the relocated charges will lead to a patterned refractive index in the material this is a hologram. 

No and depend on the coordinate, more complicated relations for the dependence of Qc on are obtained instead of Eq. (29) (see, e.g.. Ref. 41). Deviations from Eq. (29) are also observed in the presence of deep donors (acceptors), which are not ionized in the semiconductor bulk at the temperature of measurements, but become ionized in the space-charge electric field, thereby contributing to the capacity... 

The particle sizing by field flow fractionation (FFF) is based on the different effect of a perpendicular applied field on particles in a laminar flow [63-66], The separation principle corresponds to the nature of the perpendicular field and may, for example, be based on different mass (sedimentation FFF), size (cross-flow FFF), or charge (electric-field FFF). Cross-flow FFF has been applied recently to investigate nanoemulsions, SLN, and nanostructured lipid carriers (NLC, particles composed of liquid and solid lipids) [58], Although all samples had comparable particle sizes in PCS, their retention in the FFF was very different. Compared to the spherical droplets of the nanoemulsion, SLN and NLC were pushed more efficiently to the bottom of the channel because of their anisotropic shape. Their very different shapes have been confirmed by electron microscopy. 

Figure 8.3 Huckel equation and typical electropherogram. Influence of the net charge, electric field, volume of the ion and viscosity of the solution upon the migration velocity in an electrolyte animated by an electro-osmotic flow (cf. Section 8.2.2). Higher charge and smaller size confer greater mobility, whereas lower charge and larger size confer lower mobility. The separation depends approximately upon the charge-to-size ratio of each species. Uncharged species move at the same velocity as the electro osmotic flow (see later). The smaller anions arrive last since they would normally go towards the anode. At low pH, electro-osmotic flow is weak and anions may never reach the detector.

If two solutions of ions are layered one over the other with the solution of higher mobility on the bottom, then the boundary between the two will be sharp as they migrate in an oppositely charged electrical field. 

Figure 4-4. Distortion of electric field in an avalanche (a) external electric field and space charge electric field are shown separately (b) combination of the external electric field and space charge electric field.

Electrical Position of electric charge Electric field... 

Electric Moments. Atomic Charges. Electric Field Gradient Dipole Moment fx in D... 

Electric Charge, Electric Field, and Electric Potential and Their Implications for Capacitor Cell Voltage... 

If a colloidal particle is charged, electric fields can have a profound effect on the flow behaviour of the dispersion. This gives rise to a number of electrokinetic phenomena. In electrophoresis measurements, the velocity of... 

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