Data Analysis and Expected Results

The result of this analysis is a plot of photocurrent density as a function of the potential measured versus a reference electrode. An example j—V curve for a WO3 film is shown in Fig. 6.10. In this case, the photocurrent onset occurs at approximately 0.27 V versus SCE (0.54 V vs. RHE) which corresponds to a VonsecoER of 0.69 V (1.23-0.54 V). Since the onset of photocurrent does not occur cathodic of the reversible potential for HER ( er = —0.27 V versus SCE in this electrolyte), this electrode is unable to split water without an additional bias. At potentials more anodic than 1.2 V versus SCE, the photocurrent density saturates at 3.5 mA/cm. In addition to photocurrent, reverse bias dark current onsets at 1.65 V versus SCE due to shunting or breakdown as mentioned previously. 

As mentioned previously, the dark and illuminated behavior of an electrode can be characterized in a single sweep by chopping the light at a regular frequency. This is presented in Fig. 6.11, which shows the photoresponse of a Fe203-based photoelectrode exposed to periodic illumination. 

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Analysis of Size-Fractionated Particles. A series of samples was analyzed by both methods of analysis, and the results of two samples that were collected on different days are shown in Tables III and IV. The data shown in Table III illustrate that there are probably two origins of the elements. Vanadium, bromine, manganese, copper, mercury, chromium, and zinc increase in concentration as the particle size decreases. This inverse relationship is expected if these particles are emitted by high-temperature combustion processes such as automobiles and power plants (which are the major sources in this area). Sodium, aluminum, iron, scandium, and cobalt were present in an approximately uniform distribution throughout the particle size range. This relationship results... 

In this problem you will collect and analyze data in a simulation of the sampling process. Obtain a pack of M M s or other similar candy. Obtain a sample of five candies, and count the number that are red. Report the result of your analysis as % red. Return the candies to the bag, mix thoroughly, and repeat the analysis for a total of 20 determinations. Calculate the mean and standard deviation for your data. Remove all candies, and determine the true % red for the population. Sampling in this exercise should follow binomial statistics. Calculate the expected mean value and expected standard deviation, and compare to your experimental results. 

These initial experiments show that results can be obtained from this system that are comparable to those from the continuous flow reactor. The analytical system satisfies the requirements for accurate and rapid repetitive analysis. Scanning of 12 masses is possible at rates of approximately 100 ms/scan with good results. Further data manipulations are expected to yield additional results from this type of experiments. 

The acceptance criteria and data evaluation will describe the acceptance criteria or expected results for the tests. This may include a comparison of the observed response with an expected response or statistical analysis. 

Although the measurement uncertainties limit the conclusions which can be drawn from these results, the data set proved useful for the determination of general Influences on rainwater composition In the Seattle area and for the demonstration of the application of these exploratory data analysis techniques. Current efforts to collect and analyze aerosol and rainwater samples over meteorologically appropriate time scales with precise analytical techniques are expected to provide better resolution of the factors controlling the composition of rainwater. 

Determine whether there are more cost-effective alternatives to additional data generation and risk assessment refinements. What-if analyses can be used to examine the savings in risk management that might result from additional data generation. Techniques that may be suitable for this include Bayesian Monte Carlo and expected value of information (EVOI) analysis (Dakins et al. 1996). 

The detection and data analysis activities in the field of SEC applied to polymeric materials is expected to grow in the future. Improved detectors and data analysis systems will become commercially more available as a result of the current research activities in selected industrial and academic labs. 

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