This paper reports on-line monitoring of the density of linear low-density polyethylene (LLDPE) by near-infrared (NIR) spectroscopy and chemometrics. The on-line monitoring was carried out not only in a laboratory but also in a real plant. We composed an on-line monitoring system for molten polymers consisting of a Fourier transform near-infrared (FT-NIR) spectrometer, input/output (I/O) module, a personal computer, and a sampling cell that we developed. We first compared NIR spectra of LLDPE in the solid and melt states and then developed calibration models that predict the density using partial least squares regression (PLS). The sample sets for developing prediction models were collected for three months at the plant, and the density of LLDPE was continuously monitored on-line for another three months using the model. The standard error of prediction (SEP) for the on-line monitoring of the density of LLDPE at the plant was +/-2.1 mg/cm(3) (range: 0.91-0.95 g/cm(3)).
The magnetic field effects on the thermodynamic properties of chemical reactions were systematically studied. In the formulation, the chemical influence of magnetic fields due to magnetostatic energy was represented by the magneto-chemical potential for each component and the magnetic free energy change per unit reaction. Then the general formulae were derived for the magnetic field-induced changes in the equilibrium constant and the heat, free energy and entropy of reaction. In the calculation, the general formulae were applied to a ferromagnetic metal-hydrogen reaction and the magnetic field effects were numerically evaluated for two reactions in the single system LaCo 5 -H 2 . In the experiment, the magnetic field effects were observed by applying high magnetic fields of 10-30 T to the system LaCo 5 -H 2 . The observed results agreed qualitatively and quantitatively with the corresponding calculated ones. This study resolved the issue of the thermodynamic effects of magnetic fields on chemical reactions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.