Voltage time curves

Anodic oxide formation Lakhiani and Shreir have studied the anodic oxidation of niobium in various electrolytes, and have observed that temperature and current density have a marked effect on the anodising characteristics. The plateau on the voltage/time curve has been shown by electron microscopy to correspond with the crystallisation of the oxide and rupture of the previously formed oxide. It would appear that this is a further example of field recrystallisation —a phenomenon which has been observed previously during anodisation of tantalum" . No significant data on the galvanic behaviour of niobium are available however, its behaviour can be expected to be similar to tantalum. 

Fig. 5.4 Voltage-time curve for a p-type silicon electrode anodized galvanostatically at 0.1 mA cm"2 in 10% acetic acid. Silicon electrodes were removed from the electrolyte after various anodization times (filled circles) and the thickness of the anodic oxide was measured by ellipsometry (open circles). The curvature of the sample was monitored in situ and is plotted as the value of stress times oxide thickness (filled triangles). The bar graph below the V(t) curve shows a proposed formation mechanism. Galvanostatically a...

Fig. 5.10 Voltage-time curve (solid line) for an n -type silicon electrode (3 mficm) anodized with a constant current density of 6.25 mA crrf2 for t> 0 (sample at OCP for t<0) in 0.3 mol kg- NH4F (pH = 3.5). The thickness of the anodic oxide was measured by ellipsometry (open circles, broken line fitted as a guide to the eye). The etch rate of the anodic oxide in the electrolyte was measured (values above arrows) at different...

In pure digital computer systems the voltage is sampled from the voltage/ time curve of the gc at equal time intervals. After digitizing the analog voltage, the computer calculates the areas and retention times of the peaks. 

The conventional OCVD method utilizes a measurement of the slope of the V(t) vs. t decay curve for t 4Xj,. An experimental voltage-time curve is shown in Fig.7(b). Note the initial rapid voltage drop when the switch is opoied, then a nonlinear portion during the early decay, followed by a reasonably straight line. Eventually Ae decay becomes nonlinear again during the final decay stage. 

This equation was used for the interpretation of the experiments. Figure 8 shows a voltage-time curve measured at 25°C with a rod of RbAg4l5, which has a length of 7.4 cm. 

FIGURE 8 Example of a measured voltage-time curve of a dropping experiment (T = 25°C length of the rod = 7.4 cm velocity before striking = 1.44 m/s). 

The data acquisition and processing systems for the pressure measurement in the closed bombs may differ. However, they should always enable the amplification of the low-voltage signal produced at the transducer poles due to the action of the pressure, recording of the output voltage as a function of the combustion time, and treatment of the recorded data. A calibration curve (or equation) is used to transform the voltage-time curve into the pressure-time curve. This curve offers a lot of useful information necessary for the internal ballistics calculations. 

The voltage/time curve contains several characteristic points (see Figure 1.9) ... 

Figure 4.10.3 Calvanostatic electrodeposition experiments in LiCI-KCI with 0.5mol% T1CI2. The voltage time curves are typical for the second melting period (stable process)...

For a fixed voltage, a certain time delay t is elapsed before breakdown occurs. The voltage-time curves (V-t curves or life-curves ) always decrease, whatever the shape of the voltage wave (impulse, AC,... 

Voltage-time curves of Li//liFeP04 cells during normal charge/discharge and overcharge processes (a) with 5 wt.% NPM and (b) without NPM. (Adapted from Wang, B. et al., Electrochem Commun. 10 727-730,2008.)... 

Figure 30.24 Eagie Richer resen/e primary manganese dioxide-magnesium perchiorate battery voltage-time curves on activation at various temperatures (Courtesyof Eagle Richer)...

Figure 57.1 Voltage-time curves for an Eagle Picher resenre primary manganese dioxide-magnesium perchlorate battery on activation at various temperatures (Courtesy of Eagle Picher)...

Figure 2 Instrumented Charpy V-Notch Voltage-Time Curve for Toughened PVC...

Figure 5 shows the voltage-time curve with the data points indicated. This plot is used to check the settings on the time interval and number of acquired points. Also note that the time scale has been set long enough to ensure that the signal is not truncated until the fracture process is completed. Plastic tests often involve low load levels. As shown... 

Figure 5 Amplified View of Voltage-Time Curve Showing Individual Data Points for Test Performed on Toughened PVC...

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