The effect of kinetic parameters on discontinuous crystallization process

1975 ◽  
Vol 40 (9) ◽  
pp. 2592-2604 ◽  
Author(s):  
J. Nývlt
Keyword(s):  
Kinetic Parameters ◽  
Crystallization Process

Effect of Kinetic Parameters on the Dynamicsof Continuous Crystallizers

1998 ◽  
Vol 63 (1) ◽  
pp. 121-131 ◽  
Author(s):  
Jaroslav Nývlt
Keyword(s):  
Steady State ◽  
Kinetic Parameters ◽  
Production Rate ◽  
Crystal Size ◽  
Crystallization Process ◽  
Dynamic Behaviour ◽  
Nucleation And Growth ◽  
Suspension Concentration ◽  
Run Time ◽  
Periodic Cycles

Continuous crystallizers can exhibit periodic cycles of supersaturation, production rate, suspension concentration, crystal size and related quantities. These cycles are most pronounced at the beginning of the crystallization process and depend on the value of kinetic parameters whether they are damped during the run time. Apparently, the cycling behaviour of the crystallizing system depends on the value of ratio of the nucleation and growth exponents n/g. The higher the value of this ratio, the more pronounced is the instability of the system. Admixtures that have a significant effect on the kinetic parameters can dramatically affect the dynamic behaviour of crystallizers so that the steady state may not be established at all.

scholarly journals A novel analytical approach to estimate isothermal and dynamic crystallization Avrami kinetic parameters

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Hossein Ali Khonakdar ◽  
Masoud Shiri ◽  
Ahmad Asadinezhad ◽  
Seyed Hassan Jafari ◽  
Mahdi Golriz
Keyword(s):  
Kinetic Parameters ◽  
Analytical Approach ◽  
Crystallization Process ◽  
Avrami Equation ◽  
Maximum Point ◽  
Scanning Calorimetry ◽  
Avrami Model ◽  
Dynamic Crystallization ◽  
Crystallization Mode ◽  
Evaluation Of Kinetic Parameters

AbstractThe Avrami equation has been extensively used to describe the polymer crystallization kinetics. Evaluation of kinetic parameters of this equation is quite troublesome, calling for properly predetermining induction time. To avoid this problem, an analytical approach in terms of differential scanning calorimetry exotherm maximum point was adopted here so as to conveniently estimate the Avrami equation kinetic parameters both in isothermal and dynamic crystallization mode. In the case of dynamic crystallization under isokinetic conditions, a modified version of the Avrami model by Nakamura was employed and adequate predictions based on the derived formulas were obtained. However, due to the simplified assumptions of the Avrami theory, our adopted relations are only applicable to earlier stages of crystallization process and do not account for secondary crystallization.

Raman scattering studies on slow crystallization process from amorphous PbTiO3

1983 ◽  
Vol 44 (11) ◽  
pp. 313-318 ◽  
Author(s):  
Masaaki Takashige ◽  
Terutaro Nakamura ◽  
Yutaka Aikawa
Keyword(s):  
Raman Scattering ◽  
Crystallization Process

MEASUREMENT OF STEROID BINDING PROTEINS

1970 ◽  
Vol 65 (1_Suppl) ◽  
pp. S104-S121 ◽  
Author(s):  
E. E. Baulieu ◽  
J. P. Raynaud ◽  
E. Milgrom
Keyword(s):  
Kinetic Parameters ◽  
Binding Proteins ◽  
Binding Specificity ◽  
Binding Parameters ◽  
Target Organs ◽  
Biological Mixtures ◽  
Steroid Binding Proteins ◽  
Steroid Binding ◽  
Steroid Binding Protein

ABSTRACT A brief review of the characteristics of steroid binding proteins found in the plasma and in some target organs is presented, followed by some general remarks on binding »specificity« and binding parameters. Useful techniques for measuring binding parameters at equilibrium are reported, both those which keep the equilibrium intact and those which implicate its disruption. A concept is developed according to which the determination of a specific steroid binding protein is based on the »differential dissociation« of the several steroid binding complexes present in most biological mixtures. Methods which allow determination of the kinetic parameters of the binding systems are also presented. Various representations of the binding and therefore different modes of graphic representation and calculation are discussed, including the recent »proportion graph« method.

THE INFLUENCE OF ETHANOL ON THE CONVERSION OF PREGNENOLONE TO PROGESTERONE BY HUMAN PLACENTAL MICROSOMES

1974 ◽  
Vol 76 (1) ◽  
pp. 178-188 ◽  
Author(s):  
H. Lübbert ◽  
K. Pollow ◽  
R. Wagner ◽  
J. Hammerstein
Keyword(s):  
Kinetic Parameters ◽  
Enzyme Preparation ◽  
Ethanol Concentration ◽  
Hydroxysteroid Dehydrogenase ◽  
Product Formation ◽  
Linear Increase ◽  
Maximal Velocity ◽  
Microsomal Enzyme ◽  
Temperature Optima ◽  
Substrate Concentrations

ABSTRACT The effects of ethanol on kinetic parameters of placental Δ5-3β-hydroxysteroid dehydrogenase were studied. In the presence of high pregnenolone concentrations (50 μm, [S] > Km) the microsomal enzyme preparation exhibited an almost linear increase in activity as the ethanol concentration in the medium was raised from 2.5 to 15 % (v/v). At lower substrate concentrations ([S] << Km) ethanol caused inhibition. Other effects of ethanol were: linearity of product formation with time was prolonged; the maximal velocity was markedly increased; the Km for pregnenolone slightly decreased with increasing ethanol concentrations (2.5 to 10 %, v/v) whereas the Km for NAD remained the same. The pH and temperature optima of the reaction were unaffected by ethanol. Other organic solvents caused similar effects.

STUDY OF THE DEPENDENCE OF THE CRYSTALLIZATION PROCESSES OF POLYMER MICROCOMPOSITES ON THE COOLING RATE

2017 ◽  
Author(s):  
◽  
Nataliia Fialko ◽  
Viktor Prokopov ◽  
Julii Sherenkovskiy ◽  
Nataliia Meranova ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Crystallization Process

The analysis of the effect of the cooling rate on the main parameters of the crystallization process from the melt of composites obtained based on various matrices - polyethylene, polypropylene and polycarbonate, using copper microparticles as a filler is carried out.

Innovative energy and mass balance of a continuous evaporating crystallizer

2019 ◽  
pp. 646-654
Author(s):  
Jan Iciek ◽  
Kornel Hulak ◽  
Radosław Gruska
Keyword(s):  
Energy Balance ◽  
Mass Balance ◽  
Working Conditions ◽  
Crystallization Process ◽  
Heat Losses ◽  
Inert Gas ◽  
Gas Removal ◽  
Energy Balances ◽  
Heat Released ◽  
Mass And Energy Balances

The article presents the mass and energy balances of the sucrose crystallization process in a continuous evaporating crystallizer. The developed algorithm allows to assess the working conditions of the continuous evaporating crystallizers and the technological and energy parameters. The energy balance algorithm takes into account the heat released during the crystallization of sucrose, which was analyzed in this study, heat losses to the environment and heat losses due the vapor used for inert gas removal.

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