Staircase profiles

Equation 16.9 is general and is applicable to the profile of each step in the "staircase" profiles obtained in conventional binary frontal analysis. When a binary mixture is introduced as a step into an empty column (Cj = 0 and cj = C , / = 1,2), Eq. 16.9 becomes... 

Ball et al. associated the staircase profile of the (KC1)32 monotonic sequences with an efficient structure-seeker and contrasted this picture... 

The staircase profiles for (KC1)32 therefore provide for efficient relaxation to a rocksalt morphology, but not necessarily the global minimum, while the overall connectivity of the Arjg PES means that the global minimum is easily located for reasonable cooling rates (Section IV.B). 

The calculated ionization potentials of Li, Na and K reproduce the drops associated with the closing of electronic shells [6]. However, the spherical jellium yields sawtoothed curves which lack fine structure between shell closings. In addition, the sawtooth rises above the experimental data before falling sharply at the next shell-closure. This behavior contrasts with the observed ionization potential curves, which remain rather flat between magic clusters, exhibiting a staircase profile. 

Figure 17-12 Voltage profiles for voltammetry (a) linear voltage ramp used in vitamin C experiment (b) staircase profile for sampled current polarography. Inset (c) shows how faradaic and charging currents decay after each potential step.

WMM represents a stable mode solving technique, where, similar to TMM, continuous geometrical profiles and gradient index media require a staircase-approximation. Accuracy is affected if boundaries are too close to the guiding structure, or if the number of ID modes is too low, which both is easy to check. So, WMM is a stable and accurate mode-solving technique. It... 

Figure 17-15 Staircase voltage profile used in sampled current poiarography. Current is measured only during the intervals shown by heavy, colored lines. Potential is scanned toward more negative values as the experiment progresses. Lower graph shows that charging current decays more rapidly than faradaic current after each voltage step.

The most efficient voltage profile for voltammetry, called square wave voltammetry, uses the waveform in Figure 17-18, which consists of a square wave superimposed on a staircase.22 During each cathodic pulse, there is a rush of analyte to be reduced at the electrode... 

Sampled current voltammetry uses a staircase voltage profile for measurements with successive, static drops of Hg. One second after each voltage step, charging current is nearly 0. but there is still substantial faradaic current from the redox reaction. 

Variation profile of the applied potential in square-wave voltammetry, with (a) the step potential, (b) the staircase and (c) the combination of (a) and (b) into the square-wave form. 

This value is in agreement with the one derived from band profiles calculated with the equilibrium-dispersive model [9]. The time given by Eq. 16.20 provides useful information regarding the specifications for the experimental conditions under which staircase binary frontal analysis must be carried out to give correct results in the determination of competitive isotherms. The concentration of the intermediate plateau is needed to calculate the integral mass balances of the two components, a critical step in the application of the method (Chapter 4). This does not apply to single-pulse frontal analysis in which series of wide rectangular pulses are injected into the column which is washed of solute between successive pulses. 

Profiles in Column II The initial condition of coliunn II (Figure 17.5a) includes two concentration plateaus at concentration Cf and respectively, ending as a concentration staircase at the inlet of the coliunn for component 1 and at its outlet for component 2. Both profiles migrate along column II and into column III through the feed node, where they mix with the feed. Component 1 is entirely eluted from column II into columns III and then IV, but not component 2 (Figure 17.5). The profile of component 2 includes two concentration plateaus and... 

Railings, staircases, ladders, floor grids, and pipe supports showed slight scattered rust here and there. Originally, the zinc coating had been 100-125 pm. On the main constructional profiles, there was still 70-100 pm zinc coating left. No maintenance was then necessary. 

B) Potential -time profile for the staircase voltage applied to the electrode (C) Current-potential response (polarogram). f , Measuring interval Time interval of the voltage step At sijp Voltage step of the applied staircase waveform... 

FIGURE 1.65. Schematic representation of the principles of Differential Pulse Voltammetry (DPV). The input pulse profiles and the resultant current/potential profile are illustrated. Note that the potential waveform used in DPV is a composite entity comprising a staircase (or ramp) waveform superimposed on a constant-amplitude pulse sequence. The pertinent experimental parameters are indicated in the diagram. 

Fig. 2.33 Differential pulse voltammetry voltammetric profiles of AI versus staircase potential...

Fig. 2.38 Square wave voltammetry voltammetric profile of current versus staircase potential. II represents the forward and I2 the reverse sweep where A/ is the resultant voltammogram...

The course of q versus time is just like the side profile of a two-level staircase (Fig. 4.12). Up to tEi the constant rate of heat release comprises the thermal powers of the consumptions in A and C, i.e. = ( 1 + qi), in the time after that up to the... 

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