Sökning: "activity coefficients"
Visar resultat 1 - 5 av 53 avhandlingar innehållade orden activity coefficients.
1. Crystallization of Parabens : Thermodynamics, Nucleation and Processing
Sammanfattning : In this work, the solubility of butyl paraben in 7 pure solvents and in 5 different ethanol-water mixtures has been determined from 1 ˚C to 50 ˚C. The solubility of ethyl paraben and propyl paraben in various solvents has been determined at 10 ˚C. LÄS MER
2. Model for activity coefficients and solubilities of Na2CO3 and Na2SO4 in high-temperature solutions
Sammanfattning : Scaling of sodium sulfate and sodium carbonate double salts has long been recognized as a problem in the black liquor evaporation process. These salts are abundant in black liquor and often tend to precipitate on heat transfer areas, thereby significantly decreasing the heat transfer efficiency. LÄS MER
3. Solubility and polymorphism of molecular compounds
Sammanfattning : This thesis deals with the controlled crystallization of small organic molecules and is focused on solubility and polymorphism. The solubility was determined for phenylacetic acid, p-hydroxyphenylacetic acid, p-aminophenylacetic acid, p-hydroxybenzoic acid and ibuprofen in both water and in a range of organic solvents. LÄS MER
4. Investigation of vanadium-containing oxide systems : CALPHAD and experiments
Sammanfattning : Fundamental studies on thermodynamic properties of vanadium-containing oxides systems are essential to understand practical vanadium metallurgical process. The CALPHAD technique is here applied to the thermodynamic modelling of the V-O, Ca-V-O and Ti-V-O systems. The compound energy formalism is used for all the solution phases. LÄS MER
5. Origin of solar surface activity and sunspots
Sammanfattning : In the last few years, there has been significant progress in the development of a new model for explaining magnetic flux concentrations, by invoking the negative effective magnetic pressure instability (NEMPI) in a highly stratified turbulent plasma. According to this model, the suppression of the turbulent pressure by a large-scale magnetic field leads to a negative contribution of turbulence to the effective magnetic pressure (the sum of non-turbulent and turbulent contributions). LÄS MER