FTNIR

Figure 5. Predicted versus measxired plot of %DE using the FTNIR IS ensemble (C=cross validated samples and T= test set samples).

Fourier transform..., e.g. FTIR, FTNIR, FTNMR glassy carbon electrode gas electron diffraction Global Environment Facility... 

The reduction depicted in equation 53 is the basis of a method for determination of POV in the 0 to 10 meqkg range by FTNIR. Although the technical procedure is simple, data need PLS analysis because of the overlap of signals in the data acquisition region (4695 to 4553 cm- )235,435... 

FTNIR (Fourier transform near-infrared spectrophotometry), 663 FuUerene adducts, regioselective... 

In this section the mainstream NIRS technologies in current widespread practical use for PAC applications will be examined. These are scanning grating monochromators, grating polychromator PDA spectrometer, AOTF analysers and FTNIR analysers. 

However, the most significant practical issue for the implementation of an FTNIR device suitable for quantitative process analytical applications arises from the need to maintain a very high degree of alignment at the point of recombination of the divided interferometer beam paths - in other words at the exit of the interferometer. 

Although the Fourier compression method can be effective for reducing data into frequency components, it cannot effectively handle situations where the dominant frequency components vary as a function of position in the spectrum. For example, in Fourier transform near-infrared (FTNIR) spectroscopy, where wavenumber (cm-1) is used as the x-axis, the bandwidths of the combination bands at the lower wavenumbers can be much smaller than the bandwidths of the overtone bands at the higher wavenumbers.31,32 In any such case where relevant spectral information can exist at different frequencies for different positions, it can be advantageous to use a compression technique that compresses based on frequency but still preserves some position information. The Wavelet transform is one such technique.33... 

Fourier transform mid-infrared (FTIR), near-infrared (FTNIR), and Raman (FT-Raman) spectroscopy were used for discrimination among 10 different edible oils and fats, and for comparing the performance of these spectroscopic methods in edible oil/fat studies. The FTIR apparatus was equipped with a deuterated triglycine sulfate (DTGS) detector, while the same spectrometer was also used for FT-NIR and FT-Raman measurements with additional accessories and detectors. The spectral features of edible oils and fats were studied and the unsaturation bond (C=C) in IR and Raman spectra was identified and used for the discriminant analysis. Linear discriminant analysis (LDA) and canonical variate analysis (CVA) were used for the disaimination and classification of different edible oils and fats based on spectral data. FTIR spectroscopy measurements in conjunction with CVA yielded about 98% classification accuracy of oils and fats followed by FT-Raman (94%) and FTNIR (93%) methods however, the number of factors was much higher for the FT-Raman and FT-NIR methods. 

The changes in reaction rates of different species measured by FTNIR can thus be utilised as "molecular probes" of gelation and vitrification, providing simultaneous information on the progress of the chemical reaction and the transitions encountered during cure. However, the technique requires significant data analysis and is therefore not readily adapted to on-line monitoring. 

Fig. 7. Time evolution of FTnIR spectra during the isothermal curing at 70 °C of the stoichiometric HDGEBA/poly(3-aminopropylmethyl)siloxane system.

Musto, P. Ragosta, G. Mensitier, G. (2002). Time-resolved FTIR/FTNIR spectroscopy powerful tools to investigate diffusion processes in polymeric films and membranes. E-Polymers, Article N° 017 (April 2002), ISSN 1618-7229. 

Figure 4.58 Antaris II FTNIR analyzer, Thermo Scientific, equipped with a fiber-optic probe for remote measurement, transmission, and integrating sphere and a tablet analyzer for direct analysis of pharmaceuticals. ( Thenao Fisher Scientific (www.thermofisher.com). Used with permission.)...

Martin D., Wang Q. and Klevisha D. (2004), Challenges of FTNIR for Recycling of Fibrous Textile and Carpet Waste Industries , Presentation at 9th Annual Conference on Recycling of Polymer, Textile and Carpet Waste, Dalton, GA, May 10-11,... 

The polarization measurements in the mid-infrared (IR) and near-infrared (NIR) were performed on a Bruker IFS 88 FTIR/FTNIR spectrometer utilizing a wire-grid polarizer on KRS5-substrate which could be rotated pneumatically parallel or perpendicular to the selected reference direction. For the experiments in the step-scan mode a mercury-cadmium-telluride (MCT) detector with a DC-coupled preamplifier was used. This allowed an absolute intensity at each mirror position to be recorded and the use of phase-modulation-demodulation techniques, which are often applied for the step-scan mode [28-30] to be avoided. Further specific instrumental details of the individual applications are given in the corresponding sections. 

Figure 2-46. FTIR/FTNIR polarization spectra of the undrawn LSCE system (the radiation was polarized parallel and perpendicular to the subsequent drawing direction of the rheo-optical...

MK)AC Corp. 130 McCormick Avenue 111, Costa Mesa, CA 92626 TEL 714-546-4322 FAX 714.546.4311 Email info midac.com URL http //www.midac.com/ FTIR, FTNIR, open path... 

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