A system for fluidized bed granulator automation with in-line multichannel near infrared (NIR) moisture measurement and a unique air flow rate measurement design was assembled, and the information gained was investigated. The multivariate process data collected was analyzed using principal component analysis (PCA). The test materials (theophylline and microcrystalline cellulose) were granulated and the calibration behavior of the multichannel NIR set-up was evaluated against full Fourier Transform (FT) NIR spectra. Accurate and reliable process air flow rate measurement proved critical in controlling the granulation process. The process data describing the state of the process was projected in two dimensions, and the information from various trend charts was outlined simultaneously. The absorbence of test material at correction wavelengths (NIR region) and the nature of material-water interactions affected the detected in-line NIR water signal. This resulted in different calibration models for the test materials. Development of process analytical methods together with new data visualization algorithms creates new tools for in-process control of the fluidized bed granulation.
In the past decade interest has focused on the remote analysis of emissions from motor vehicles using spectrometric techniques, driven by recognition of the fact that a very large proportion of the environmental damage done in this way originates with a small percentage of vehicles. Several instrumentation manufacturers now market such devices, and others are developing new technologies that will offer opportunities for enhanced performance and lower cost.In this paper we review the evolution of technologies and methodologies applied to motor vehicle exhaust emissions, ranging from simple broadband sources and band-pass filters to tunable diode laser absorption spectroscopy. In so doing we examine the compromises and sources of error inherent in each which have earned such devices a very variable reputation, at least in the early years of development. We also look at techniques that may have the potential to solve these problem, and critically examine the reasons why these have not (yet) been applied.In conclusion, we will present initial findings and results from a European consortium studying the problems of costeffective emissions monitoring, and validation of emissions inventory data using complementary numerical modelling techniques.
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