Mixtures behavior, quantitative measurement

In addition to the visual observations of the dynamic responses, a quantitative measure is needed to provide a better comparison. With such an objective, lAE values were evaluated for each closed-loop response. The PUL option shows the lowest lAE value of 5.607 x 10 , while the value for the Petlyuk column turns out to be 2.35 x 10. Therefore, the results of the test indicate that, for the SISO control of the heaviest component of the ternary mixture, the PUL option provides the best dynamic behavior and improves the performance of the Petlyuk column. Such result is consistent with the prediction provided by the SVD analysis. 

In a previous paper (6), we have reported (quantitative measurements of phase compositions and molar volumes for licquid-licquid-gas, licquid-licquid-licquid, and licquid-licquid-licquid-gas ecquilibria for ternary mixtures of water, carbon dioxide, and isopropanol at 40 , 50 , and 60 C and elevated pressures. The phase behavior observed at these conditions was found to be (quite complex. 

Rhodium supported on y-ALOs is an important component of 3-way automotive catalysts and has been studied by a wide variety of methods [1-5] including ESR. In the last 15 years Rh-species introduced into zeolites of different types (Y, X, L, A, SAPO) have also been examined by several techniques [6-9]. However, most of these methods were applied after the specimens were removed from actual reaction conditions and transferred into the respective characterization instruments and the state or behavior of the catalyst in-situ was arrived at indirectly by inference. Also the deactivation processes or the effect of modifiers is seldom, if ever, determined by direct in-situ observations. We have previously devised a method for high-temperature measurement of ESR-active ions under flow conditions and applied it to characterize specimens containing Cu [10] or Cr " [11]. We have extended this method now to specimens containing Rh. Here, we summarize the results of a study of the interaction of Rh/y-ALOB and Rh/ZSM-5 with different gases and gas mixtures (NO, NO2, CO, propene, O2, H2O) at 120-573 °K. The amount of Rh present in the samples is evaluated quantitatively. The effect of copper and lanthanide addition on the stabilization of by the zeolitic matrix was also investigated. 

Quantitative and (hopefully, at least) qualitative considerations are helpful in characterizing a liquid-liquid system for a potential extraction application. Batch shakeout tests are frequently the easiest way to determine basic feasibility by simply measuring the primary and secondary break times and by analyses to measure the compositions of the equilibrated phases. Such tests are readily conducted by mixing small volumes of each phase in a vial, which is then vigorously agitated and placed on a lab bench to settle. The resulting behavior of the liquid-liquid mixture depends on physical properties and system characteristics. The greater the density difference and interfacial tension between the two liquid phases, for example, the more rapidly the phases tend to separate. More viscous systems separate more slowly. 

A Mass Spectrometer (MS) (Balzers QMS200) was used for species analysis. This instrument can provide the qualitative and quantitative temporal evolution of the composition of the outlet gas mixture. The following m/e ratios were monitored in order to follow the transient behavior of the most relevant species 15 (NHj), 18 (H2O), 28 (N2), 30 (NO), 32 (O2), 40 (Ar), 44 (NjO), and 46 (NO2). The MS data were elaborated taking into account the species cross-sensitivities and the response factors periodically estimated by means of specific calibration runs in a blank reactor, thus obtaining the outlet concentrations of reactants and products. A UV analyzer (ABB Limas IIHW), which provided accurate continuous simultaneous measurements of ammonia, NO, and NO2, was also coupled in parallel to the MS [10]. 

In this respect, the in silico prediction of the thermodynamic mixing behavior of different polymer-drug/excipient mixtures is of central interest. A common approach to cope with this problem is the calculation of the solubility parameters according to Hildebrand or Hansen [9-12], which is standard in the development of polymer mixtures [13]. The use of highly developed force fields as the basis of any MD simulation software enables the calculation of solubility parameters with accuracy comparable to those measured experimentally by inverse gas chromatography [14], and an increasing number of other statistical quantitative property relationships between simulated and experimental values are established [15-18]. 

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