Serpentine interface

Figure 26. Chromatograms of a blood sample using both the UV detector and AAS detector employing the serpentine interface.

The low dispersion serpentine tube developed by Katz et e> OO) was an alternative approach to the coiled tube and was designed to increase secondary flow by actually reversing the direction of flow at each serpentine bend. A diagram of a serpentine tube is shown in figure 3. In fact, the serpentine tubing shown in figure 3 was designed to be an interface... 

FIGURE 4.21 Photograph of the glass microchip (5x2 cm) used for sample injection, separation, and interfacing into the MS system. To minimize the diffusion loss of the sample during separation, the connection between the side channels (leading from Q, R, T, U) and the serpentine separation channel (75 pm deep) was etched to 25 pm (one-ninth of the cross section area of the separation channel) [296]. Reprinted with permission from the American Chemical Society. 

Chromatograms of a Blood Sample Monitored by the UV Detector and the Atomic Absorption Spectrometer with the Serpentine Tube Interface... 

Katz and Scott [42] solved this problem by the use of low dispersion serpentine tubing as the interface between the exit from the UV detector of the liquid chromatograph and the spectrometer. A diagram of their interface is shown in figure 43. The principle of low dispersion tubing has already been discussed and it is sufficient to say that the outer interface tube was 49 cm long, 0.25 cm I.D. and merely protected the serpentine tube contained inside. The inner serpentine tube had a peak-to-peak amplitude of 1 mm. An example of the chromatograms obtained from a blood sample monitored by both a UV... 

Fig. I a The FIA IV-I and II integrated biosensor systems I concentrated sample solution, 2 diluted sample solution, 3 reagent solution, 4 eightK hannel distribution valve, 5 peristaltic pump, 6 microreactors, 7 eightway injection valve, 8 temperature chamber control, 9 colorimeter, 10 micro computer, II waste, 12 coil, 13 peristaltic pump for sample dilution, 14 phosphate buffer, b The SIA integrated biosensor system I, 2 and 3 phosphate buffer solution 4 ethanol diluted sample 5 reagent solution 6 waste 7 1,000-pl micro-buiette 8 500-pl micro-burette P peristaltic pump 10 two three-way valves II six-channel distribution valve 12 colorimeter, 13 serpentine 14 AOD-immobilized microieactor 15 HRP-immobilized microreactor, 16 computer 17 Interface RS-232/RS-485...

As a matter of fact, the cell parameters of the conductance cell have to be known. Hence, in order to optimize the ratio between interface area and electrode distance, miniaturized, serpentined, and interdigitated elecbodes have been used (see Fig. 5b) (40, 41]. 

Among the techniques used to characterize silica-supported Ni phases, FTIR spectroscopy is shown to be well adapted to identify ill-crystallized phases generated during the preparation by the competitive cationic exchange method. FTIR spectroscopy permits to discriminate a phyllosilicate of talc-like or serpentine-like structure from a hydroxide-like phase. Samples submitted to hydrothermal treatments have also been characterized by other techniques such as EXAFS and DRS spectroscopies. The pH and the specific surface area strongly influence the nature of the deposited phase, since they control the solubility and the rate of dissolution of silica. The results are discussed in terms of the respective amounts of soluble Si(OH>4 monomers and NP+ complexes at the interface. The relevant parameter as the Ni/Si ratio at the solid-liquid interface is assumed to control the routes to Ni-Si (Ni-Ni) copolyinerization (polymerization) reactions leading to supported Ni phyllosilicates (Ni hydroxide). 

Stack Configuration The individual cells in bipolar plate stacks such as the PEFC are typically connected in series, with current collection across the entire electrode surface along the interface between the bipolar plate landings and the DM. The flow fields in AFCs are similar to those used in other fuel cells, and various parallel and serpentine configurations are used to optimize mass, heat, and reactant/product transport. 

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