Influence of the longest ethylene and isotactic propylene sequences on crystallization elution fractionation of ethylene/propylene copolymers

Crystallization elution fractionation (CEF) is the newest crystallization-based technique for estimating the chemical composition distribution of ethylene/1-olefin copolymers. Understanding the separation mechanism of CEF for ethylene/propylene copolymers over their full compositional range is challenging because the crystallizabilities of the copolymer chains depend on the longest ethylene sequence and on longest isotactic propylene sequence. We developed a mathematical model to describe the CEF mechanism for ethylene/propylene copolymers over the entire compositional range using population balances for the crystallization and dissolution stages. The joint distribution of longest ethylene and isotactic propylene sequences determines how the copolymer populations crystallize and dissolve. The model was validated with experimental CEF profiles of ethylene/propylene copolymers varying from pure ethylene to propylene homopolymers.     

Application of computer vision technique for on-line monitoring of shrimp color changes during drying

The effects of drying temperature and drying medium velocity on color change kinetics of shrimp viz. lightness (L^∗), redness (a^∗), yellowness (b^∗), total color difference (ΔE), chroma (CH), hue angle (H°), and browning index (BI) were on-lineally investigated. Drying experiments were carried out on dryer equipped with computer vision systems using hot air drying (HAD) temperatures of 50–90 °C and superheated steam drying (SSD) temperatures of 110–120 °C at drying medium velocities of 1–2 m/s. Zero-, first-order, and fractional conversion models were utilized to describe the color changes of shrimps and the fractional conversion model successfully tracked the experimental data. The results showed that the color parameters were significantly influenced by the studied parameters. Lightness of the samples decreased, while other color parameters increased as drying proceeded. Generally, increasing drying medium temperature decreased L^∗ and H°, whereas increased other color parameters. The color characteristic of the SSD finished products were acceptable than the HAD processed samples. Finally, dimensionless moisture content of shrimps during drying was accurately correlated to the color parameters and drying time using a quadratic regression model. Moisture ratio had strong relationship with the lightness change compared with the redness and yellowness variations.     

A hybrid multiscale filter along with an improved adaptive SVR technique for fault diagnosis and machine learning modeling: forecasting the octane number of gasoline in isomerization reactor

Neural Computing and Applications - Using a reliable predictive model is important for modeling, controlling, and optimization of the isomerization process. This process has a significant impact on...