Plot spectra

The plotted spectra shall be included with the pump test results. 

The FFT spectra shall include the range of frequencies from 5 FIz to 2Z times running speed (where Z is the number of impeller vanes in multistage pumps with different impellers, Z is the highest number of impeller vanes in any stage). If specified the plotted spectra shall be included with the pump test results. 

To set up the page layout for plotting spectra several tasks have to be performed. They include the definition of the plot region, of the spectrum components to be included in the plot (spectrum, integral, peak labels, axis, of the title, of the contents of the parameter table and any additional imported data to be added to the layout such as the formulae or molecular structure. To inspect the final layout prior to plotting. WIN-NMR offers the Preview option which shows an exact copy of your subsequent plot on the screen and allows you to perform final adjustments and rearrangements on the screen. 

This section gives an overview of the most important options for plotting spectra available in the Output pull-down menu of 2D WIN-NMR (Fig. 4.30). These options affect the output of the 2D spectrum, its projection spectra in Fl and F2, the title text and the parameter lists. The 2D spectrum and corresponding projection spectra, either calculated from the 2D data itself or separately measured as a standard 1D spectrum can be displayed on the screen in the 2D WIN-NMR window or sent directly to a hardcopy device. 

The 300 MHz H NMR and 20 MHz 13C NMR spectra of poly(4-methyl-l-pentene) have been found to be more complex than the corresponding spectra of poly(3-methyl-l-butene) due to the presence of an additional isomer structure in the polymer. Investigation of the 20 MHz 13C NMR spectrum of the polymer has indicated that placement of units in different triad sequences is die cause of multiple methyl proton resonances which have been observed in the H NMR spectra of poly(3-methyl-l-butene) and poly(4-methyl-l-pentene). The use of a computer program for simulating and plotting spectra has enabled measurements of polymer composition to be made of poly(4-methyl-l-pentene) s prepared under a variety of synthesis conditions. 

Fig. 18 Composition-dependent impedance spectra at jo = 0.01 A cm-2. The plotted spectra are calculated from Eq. (103). For high electrolyte contents, Xe > 0.3, Eq. (92) gives good results. The reference parameters used are b = 30 mV, / = 10-7 A cm-2,...

Line plots (spectra, chromatograms, concentration profiles)... 

Printed or plotted spectra from any mass spectrum collected. 

The command Print Spectra uses a template to create a plot of spectra and all associated parameters. After loading as usual the relevant spectrum into the window of the Select Files page of the Plot Spectra dialog box (Fig. 13.2), it is necessary to choose a page layout. Hence, use the Change Layout button to select a template from the folder OPUSDEMO Scripts (see Fig. 13.3). To inspect the final layout prior to plotting, click on the Preview button to open another window that shows an exact copy of the subsequent plot. An example of such a print preview is displayed in Fig. 13.4. 

Figure 13.2. The Plot Spectra dialog box Select Files page.

An infrared spectrum can be a plot of either absorbance A or transmittance T versus wavelength or wave number. The convention in this country is that the ordinate scale is usually set up in such a way that absorption peaks appear as valleys in the curve, regardless of whether absorbance or transmittance is plotted on the ordinate. Foreign laboratories often plot spectra with the scale arranged differently, and these appear upside down compared to ours but both types give equivalent information, and one should be familiar with them both. 

Last but not least, modern chromatography data systems are equipped with a powerful report generator. An integrated Excel-compatible spreadsheet, for example, makes it easy to analyze data and to present results in the way the consumer wants to see them. Report workbooks can include result tables, chromatograms, calibration plots, spectra, audit trails, and even custom equations and charts. Every cell, table, and chart updates instantly if any of the source data changes. Thus, the operator never has to worry about consistency. 

The simplest form of using spectroscopy is to simply scan materials and overlay the spectra. The usual approach for comparing a sample with a reference by eye is to hold their plotted spectra on top of one another in a kind of overlay technique. The identity is given according to the U.S. Pharmacopoeia if the absorption maxima are at the same wavelengths. This method is applicable to materials that are sufficiently different. However, this method would most likely be unable to discern small differences between materials or detect adulteration. 

Figure 3, Interpolated plots of FTIR spectra acquired daily from sub-samples drawn from a microalgal culture undergoing starvation of nitrogen (top plot) and then re-supply of nitrogen to the same culture (bottom plot). Spectra taken from the N-starved culture are denoted by n- and spectra acquired during the re-supply of nitrogen by R.

Figure 2.8 shows an example of SIMPLISMA applied in the pixel and in the spectral direction to an emulsion image with four compounds (a drop, an interphase, an additive, and an off-drop constituent). In Figure 2.8, a-d are the purest pixels selected in the image and provide the plotted spectra on the right. Labels 1-4 are the purest spectral channels that, once refolded, give the distribution maps at the bottom of the figure. 

Figure 6 FT-Raman stack-plot spectra of scrimshaw specimens (a) hollow sperm whale tooth, (b) solid sperm whale tooth, (c) whalebone staybusk and (d) spill vase/quill pen holder. Minor spectroscopic differences confirm the whalebone origin of the staybusk. The modern resin composition of the spill vase/quill pen holder is also unambiguously identified from the aromatic ring stretching bands at 3060 cm- and 1600 cm-. Reproduced with permission from Edwards HGM, Farwell DW, Sedder T and Tait JKF, Scrimshaw real or fake An FT-Raman diagnostic study. Journal of Raman Spectroscopy, 26 623-628 1995, John Wiley and Sons Ltd.

The letter L in the figure denotes the pathlength of the sample, which is the thickness of sample encountered by the infrared beam. Since the beam passes through the entire sample, bulk contributions are emphasized and surface contributions are minimized, as shown in Figure 4.1. Sample thicknesses of 1 to 20 microns are typical. Transmission sampling should not be confused with transmittance, which is a y-axis unit used to plot spectra, which was discussed in Chapter 1. 

Fig. 3. The INS spectra (HET, T=5 K) for H2O dep-ice (solid curve-1 widi points) and ice-Ih (dashed curve-2 with crosses) in the range of (a) inter-molecular translational vibrations (the plotted spectra are shifted along the y-axis, for better comparison the spectrum 2 is also plotted over the spectrum 1 as a dashed curve) (b) bending modes and (c) stretching modes (an estimated time-independent background is shown as a long-dashed curve-3).

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