This paper is focused on issues of process modeling and two model based control strategies of a fed-batch sugar crystallization process applying the concept of artificial neural networks (ANNs). The control objective is to force the operation into following optimal supersaturation trajectory. It is achieved by manipulating the feed flow rate of sugar liquor/syrup, considered as the control inpu...

We report on the structural transformations of Bioglass® during thermal treatments. Just after the glassy transition, at 550 °C, a glassy phase separation occurs at 580 °C, with the appearance of one silicateand one phosphate-rich phase. It is followed by the crystallization of the major phase Na2CaSi2O6, from 610 to 700 °C and of the secondary phase, silicorhenanite, at 800 °C. The latter evol...

Crystals that are likely rhombohedral of Zn-insulin hexamers form in the islets of Langerhans in the pancreases of many mammals. The suggested functions of crystal formation is to protect the insulin from proteases and increase the degree of conversion of soluble proinsulin. To accomplish these ends, crystal growth should be fast and adaptable to rate fluctuations in the conversion reaction. Zn...

One of the main routes to obtain nanostructured materials is through the primary crystallization of metallic glasses. In such transformations, crystallites with a different composition than the amorphous precursor grow with a diffusion-controlled regime. Particle growth is slowed and eventually halted by the impingement between the concentration gradients of surrounding particles. Primary cryst...

In this study, results of the crystallization of iron-rich glasses are summarized. Thermogravimetry (TG)±di€erential thermal analysis (DTA) were utilized to explain the phase formations and the surface oxidation of FeO to yield Fe 2 O 3. The crystal phases fraction was evaluated utilizing X-ray di€raction analysis (XRD). Low angle XRD technique was used to investigate the distribution of the cr...

A thorough understanding of crystallization kinetics for rapid polymer solidification during the fiber spinning process is a route to maximizing fiber properties while increasing production speeds. We are using theoretical, computational, and experimental models to characterize the crystallization process at the molecular, microscopic, and macroscopic levels. Polymer dependent molecular descrip...

The ability to control the crystallization behaviour (including its absence) of particles, be they biomolecules such as globular proteins, inorganic colloids, nanoparticles, or metal atoms in an alloy, is of both fundamental and technological importance. Much can be learnt from the exquisite control that biological systems exert over the behaviour of proteins, where protein crystallization and ...

In this paper we present measurements of the crystallization kinetics of binary mixtures of two different sized hard sphere particles. The growth of the Bragg reflections over time were analyzed to yield the crystallite scattering vector, the total amount of crystal, and the average linear crystal size. It was observed that a particle size distribution skewed to higher sized particles has a les...

The kinetics of nanocrystallization of a Mn-doped FINEMET alloy from its amorphous precursor is reported. The alloy studied was of a composition (Fe1 Mn )73 5Nb3CuSi13 5B9 where = 0 05. X-ray diffraction (XRD) confirmed that -FeSi is the product of primary nanocrystallization. Crystallization kinetics were studied using time-dependent magnetization, ( ), as a measure of the volume fraction crys...