Showing papers by "Ganesan Narsimhan published in 1996"
TL;DR: In this article, the breakage rate and daughter-drop distribution functions were determined using an inverse-problem approach which takes advantage of self-similarity of transient distributions using an image analysis technique.
98 citations
TL;DR: In this article, the dynamics of adsorption of bovine serum albumin and its derivatives at the air-water interface were investigated through the measurement of dynamic surface pressure using a Langmuir minitrough.
41 citations
TL;DR: In this paper, the population balance equation for an emulsion in a column in which creaming, Brownian diffusion, and coalescence of drops occur simultaneously is analyzed, revealing the existence of a dynamic zone at the top of the column.
Abstract: Stored emulsions undergo various destabilizing processes including creaming and coalescence of drops. Many experimental studies have been carried out in the past to quantify drop coalescence; however, the presence of two distinct types of coalescence mechanismsone due to the relative motion between the drops and the other due to their permanent proximity to each other in the creamhas not been recognized. Furthermore, the effects of creaming in these investigations could not be eliminated in ways that do not introduce new modes of coalescence or alter the existing ones. The population balance equation for an emulsion in a column in which creaming, Brownian diffusion, and coalescence of drops occur simultaneously is analyzed. The analysis reveals the existence of a dynamic zone at the top of the column in which the net effect of creaming and Brownian diffusion of drops is eliminated. Thus, while the drops cream, diffuse, and coalesce as in an actual emulsion, the measurements from this zone allow the effect...
24 citations
TL;DR: In this paper, three two-layer diffusion and adsorption models were solved numerically to gain insight into these effects and determine the conditions at which Trurnit's method is reliable.
11 citations
TL;DR: The model predictions of precipitation curves of human serum albumin at the isoelectric point using polyethylene glycol (PEG) for different initial protein concentrations and molecular weights of PEG agreed well with the experimental data.
Abstract: A statistical thermodynamic model for the prediction of precipitation curves of globular proteins using nonionic polymers has been proposed. The model accounts for protein-polymer, polymer-solvent, electrostatic, and hydrophobic interactions as well as the entropy of mixing and employs simplifying assumptions such as spherical globular protein molecule with uniform surface properties and linear, homogeneous polymer uniform with respect to molecular weight. The proposed model can only be employed to predict precipitation curves of charged proteins at sufficiently high ionic strengths since it does not account for electrostatic protein-protein interactions due to overlap of electrical double layers. The model predictions of precipitation curves of human serum albumin (HSA) at the isoelectric point using polyethylene glycol (PEG) for different initial protein concentrations and molecular weights of PEG agreed well with the experimental data. Higher polymer concentrations were found to be required to...
6 citations
TL;DR: In this article, the structure of adsorbed protein layers at air/water interfaces has been elucidated by neutron reflectance, and a new mechanism of thin film drainage at high protein concentration has been demonstrated.
Abstract: Destabilization of protein-stabilized food foams by some ingredients has been shown to be due to disruption of protein-protein interactions in the adsorbed protein layer. The structure of adsorbed protein layers at air/water interfaces has been elucidated by neutron reflectance. A new mechanism of thin film drainage at high protein concentration has been demonstrated. Drainage models have been developed to predict.syneresis and collapse of equilibrium foams.
6 citations
TL;DR: Flexible random-coil structure of polymer molecules and protein−polymer and polymer−solvent interactions were accounted for in the evaluation of the interaction potential between two globular prote...
Abstract: Flexible random-coil structure of polymer molecules and protein−polymer and polymer−solvent interactions were accounted for in the evaluation of the interaction potential between two globular prote...
6 citations