As mathematical modeling has been proposed to overcome such considerable effort in particular
by providing maximum acceptable concentrations in the formulation, the compliance testing problem is efficiently reduced to the identification of substances and to their extent in initial materials. This work examines a fast identification and quantification procedure based on a semisupervised deconvolution procedure of FTIR spectra of polymer extracts in dichloromethane. The inversion procedure was implemented as a Tikhonov least-square problem and designed to work on large and open dictionary of substances by combining both spectra of reference additives and normalized responses of typical chemical functions. The sparsity LY2835219 order of the overall solution was fulfilled with non-negativity constraints, while traces were detected by an iterative reweighting and stochastic resonance. The whole methodology was calibrated onto 21 typical additives of polyolefins and satisfactory tested on numerical examples and on extracts of processed films in high-density polyethylene including up to eight unknown compounds. Maps of
selleck screening library possible confusions and biases were generated for all tested substances. The mass balance laws for molecules belonging to similar classes of additives were particularly highlighted. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 1492-1515, 2011″
“The pyrochlore oxides (A(2)B(2)O(7)) exhibit a remarkable range of structural, physical, and magnetic properties related to their various chemical compositions. This article reports the phase transformations induced by high electronic excitation in pyrochlores of the Gd-2(ZrxTi1-x)(2)O-7 family irradiated with swift ions. The structural changes, investigated by using several analytical techniques (x-ray diffraction, Raman spectroscopy, YM155 concentration and transmission electron microscopy), strongly depend on the chemical composition. The high electronic excitation along the ion trajectory results in the amorphization of ion tracks for Gd2Ti2O7 and Gd2TiZrO7, whereas a defective fluorite structure is formed in Gd2Zr2O7. Moreover, the results underline
the existence of an electronic stopping power threshold of 6 keV/nm for amorphizable compounds and 10 keV/nm for Gd2Zr2O7, below which phase transformations do not occur. Finally, the study of the thermal recovery of irradiated pyrochlores provides the recrystallization temperature for amorphized samples and reveals differences in the recovery process which are related to the chemical composition. (C) 2010 American Institute of Physics. [doi:10.1063/1.3503452]“
“Nonisothermal crystallization of a segmented copolymer constituted by glycolide and trimethylene carbonate units was studied from both the melt and the glass state by optical microscopy, differential scanning calorimetry and time-resolved X-ray diffraction techniques.