Spray schematic view

Fig. 5.3. A photograph of the spray generated in an electrospray ionization source (top) and a schematic view of the processes involved (bottom). From the Taylor cone, a jet is emitted and expands to a plume of micrometer-sized charged droplets from which finally desolvated ions are produced.

One can also find a functional form for the trajectory of the large droplets that are formed at the CBL. The path of these droplets represents the maximum spray penetration. Since they are not connected to the jet and are in direct contact with a strong gas flow, they do not necessarily follow a path of the form of (29.9) anymore. A schematic view of the trajectory of these drops is shown in Fig. 29. Ic with a local coordinate system attached to the CBL for convenience. In general most applications of LJICF are concerned with high momentum ratios for which the jet deflection is not pronounced. For those cases, it is fair to assume that the droplets formed at the CBL have a zero initial velocity in the x-direction as they separate fi om the jet and have an initial upward velocity of mj. As these droplets leave the jet, they lose their vertical velocity and speed up in the gas-streamwise direction and finally reach their terminal x-direction velocity. Of course, all these are true for one droplet without considering its interaction with other droplets and also with neglecting the effects of evaporation. With these assumptions, the equations governing the motion of the drop take the form... 

These first experiments were based on symmetric cells with an electrode diameter of 10 mm, so-called button cells. The electrolyte was of the yttria-stabihzed zirconia (YSZ) type, 8YSZ based on 8mol% yttria-stabilized zirconia, with a thickness between 130 and 150 pm. On both sides, the electrode was applied by screen-printing or wet powder spraying (WPS) with a thickness of 50 pm, and the porosity was about 30%. A schematic view of a cross-section of the cell geometry is depicted in Figure 9.2. Various types of cathodes were screened by potentiodynamic current-potential measurements. Comparison of the electrochemical behavior in relation to material composition was based on the measured current density at an overpotential t] of—0.1 V. 

Figure 1.5. (a) Schematic of spray forming process (b) a pilot-plant scale facility for spray forming at University of Bremen, Germany. Top top view. Bottom side view (Courtesy of Prof. Dr.-Ing. Klaus Bauckhage at University of Bremen, Germany.)... 

Figure 7.1 Silicon micropillar array electrospray ionization (fiPESI) chip, (a) (A) Setup of the pPES measurements. (B) Eormation of the Taylor cone and spray from the small (4 mm X 9 mm) fiPESI chip. The diameter of the pillars was 60 /tm and the distance between the pillars was 15 pm. The liquid sample contained 95% acetonitrile, 4.9% water and 0.1% formicacid. The high voltageappliedtothechipwas3kV. (b) Schematic of the cross-sectional and top views of the chip design during fabrication [34]. Reproduced from Nissila, T, Sainiemi, L, Sikanen, T, Kotiaho, T, Eranssila, S., Kostiainen, R., Ketola, R.A. (2007) Silicon Micropillar Array Electrospray Chip for Drug and Biomolecule Analysis. Rapid Commun. Mass Spectrom. 21 3677-3682 with permission from John Wiley and Sons...

The experimental arrangement is shown schematically in Figure 17.4. A narrow jet of hot nitrogen is directed at the sample at a point within or just before the field of view of the spectrometer. A stream of helium that has been chilled by passing it through a liquid-nitrogen bath is often sprayed on the sample at a location after the field of view to return the sample temperature to near ambient. To achieve maximal sensitivity, spectra are typically measured with a MCT detector. 

---