Equivalent charge diameter

Wen et al. reviewed the two common approaches to bipolar charging of spherical particles the Boltzmann charge distribution and the steady-state ion diffusion flux toward a sphere [30-33]. Using these approaches, an equivalent charge diameter was introduced to extend the use of these approaches to include prolate particles. The equivalent charge diameter is defined as... 

Figure 9.14. Sample diameter as a function of the equivalent mobility diameter Error bars A and B correspond to two nanotubes one with few charges (A) and the other with many (B).

The number of charges found from Eq. (33) was then used to recalculate the equivalent mobility diameter in Eq. (28) for each nanotube. Figure 9.14 illustrates the result. 

In this expression, Wp is the weight of particles titrated (g), Cb and Vb are the concentration of the base (i.e., titrant) and the volume of the base at equivalence point. The surface charge density can be calculated for the particles having a known diameter by means of the following expression ... 

Figure 28. Semiconductor interfaces with increasing electric fields in the space charge layer (from top to bottom) compared with tubes of different diameters through which an equivalent amount of water is pressed per unit time (equivalent to limiting current).

STAND-OFF STICKS FASTENED TO CHARGE ARE EQUIVALENT IN LENGTH TO DIAMETER OF CHARGE... 

Philip et al. demonstrated that the mass of a polyvinyltoluene microsphere with a nominal diameter of 2.35/rm was 6.979 0.177pg (1 pg = 10 g). The microspheres examined had charges equivalent to 39-71 elementary charges. This procedure fails, however, when the number of charges is large. 

An atomic unit of length used in quantum mechanical calculations of electronic wavefunctions. It is symbolized by o and is equivalent to the Bohr radius, the radius of the smallest orbit of the least energetic electron in a Bohr hydrogen atom. The bohr is equal to where a is the fine-structure constant, n is the ratio of the circumference of a circle to its diameter, and is the Rydberg constant. The parameter a includes h, as well as the electron s rest mass and elementary charge, and the permittivity of a vacuum. One bohr equals 5.29177249 x 10 meter (or, about 0.529 angstroms). 

There have been several proposed mechanisms for the operation of these sensors (Gopel, 1985 Franke et al., 2006). They all seem to converge on the existence and modulation of the Schottky barrier heterojunctions formed between the grains of the polycrystalline layer. They are equivalent to a chain of resistive elements connected in series. The density of surface states affects the depth of the Schottky barrier and depends on the interaction with the adsorbate (Fig. 8.8). The size of the grains apparently plays a major role. As the diameter of the grains decreases to below 5 nm, the space charge is smeared and the relative response of the sensor increases (Fig. 8.9). 

In principle, the negatively charged, presumably planar network I can be combined with one molar equivalent of tetraalkylammonium ion IGN"1" of the right size as interlayer template to yield a crystalline inclusion compound of stoichiometric formula (IGN+) I C(NIG ) ICO2 that is reminiscent of the graphite intercalates. Anionic network n, on the other hand, needs twice as many monovalent cations for charge balance, and furthermore possesses honeycomb-like host cavities of diameter 700 pm that must be filled by... 

---