TY  - CONF
AU  - Pajić-Lijaković, Ivana
AU  - Plavsić, M.
AU  - Nedović, Viktor
AU  - Bugarski, Branko
PY  - 2008
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/1638
AB  - Aim. A phase-field mathematical model was formulated to describe yeast cell growth within the Ca-alginate microbead during air-lift bioreactor cultivation. Model development was based on experimentally obtained data for the intra-bead yeast cell volume fraction profile within the microbead after reaching the equilibrium state for cells (150 h), as well as, total yeast cell volume fraction per microbead and microbead volume as functions time. Microbead with growing yeast cells is treated as a two-phase system. one phase represents the cell agglomerates, while the other is the alginate hydrogel matrices. The interactions between phases are simulated using the Langevin class, non-conservative phasefield model based on the reduction of the modeling resolution. The model considered the growth of small domains of one phase (cell agglomerates) as nucleation. Methods. Total yeast cell volume fraction in the beads was estimated by using Thoma counting chamber after dissolution of beads. Local cell volume fraction per microbead layers is calculated from experimentally determined surface fraction of cells for various microbead cross sections by image analysis. Microbead volume is estimated by measuring the microbead diameter. Diameters of microbeads were measured using the optical microscope equipped with a micrometric device. Results. The proposed model offered the only one model parameter, which represents the specific measure of microenvironmental restrictive action to the cell growth dynamics. The optimal value of this model parameter is obtained by comparison analysis between experimental data and model predictions. Conclusion. Besides giving useful insights into the dynamics of restrictive cell growth within the Ca-alginate microbead, the model can be used as a tool to design/optimize the performance of microbead and studying the microenvironmental restrictive mechanism action of the cell growth.
C3  - Minerva Biotecnologica
T1  - Modeling of microenvironmetal restricted yeast cell growth within Ca-alginate microbead
EP  - 102
IS  - 2
SP  - 99
VL  - 20
UR  - https://hdl.handle.net/21.15107/rcub_agrospace_1638
ER  - 

@conference{
author = "Pajić-Lijaković, Ivana and Plavsić, M. and Nedović, Viktor and Bugarski, Branko",
year = "2008",
abstract = "Aim. A phase-field mathematical model was formulated to describe yeast cell growth within the Ca-alginate microbead during air-lift bioreactor cultivation. Model development was based on experimentally obtained data for the intra-bead yeast cell volume fraction profile within the microbead after reaching the equilibrium state for cells (150 h), as well as, total yeast cell volume fraction per microbead and microbead volume as functions time. Microbead with growing yeast cells is treated as a two-phase system. one phase represents the cell agglomerates, while the other is the alginate hydrogel matrices. The interactions between phases are simulated using the Langevin class, non-conservative phasefield model based on the reduction of the modeling resolution. The model considered the growth of small domains of one phase (cell agglomerates) as nucleation. Methods. Total yeast cell volume fraction in the beads was estimated by using Thoma counting chamber after dissolution of beads. Local cell volume fraction per microbead layers is calculated from experimentally determined surface fraction of cells for various microbead cross sections by image analysis. Microbead volume is estimated by measuring the microbead diameter. Diameters of microbeads were measured using the optical microscope equipped with a micrometric device. Results. The proposed model offered the only one model parameter, which represents the specific measure of microenvironmental restrictive action to the cell growth dynamics. The optimal value of this model parameter is obtained by comparison analysis between experimental data and model predictions. Conclusion. Besides giving useful insights into the dynamics of restrictive cell growth within the Ca-alginate microbead, the model can be used as a tool to design/optimize the performance of microbead and studying the microenvironmental restrictive mechanism action of the cell growth.",
journal = "Minerva Biotecnologica",
title = "Modeling of microenvironmetal restricted yeast cell growth within Ca-alginate microbead",
pages = "102-99",
number = "2",
volume = "20",
url = "https://hdl.handle.net/21.15107/rcub_agrospace_1638"
}

Pajić-Lijaković, I., Plavsić, M., Nedović, V.,& Bugarski, B.. (2008). Modeling of microenvironmetal restricted yeast cell growth within Ca-alginate microbead. in Minerva Biotecnologica, 20(2), 99-102.
https://hdl.handle.net/21.15107/rcub_agrospace_1638

Pajić-Lijaković I, Plavsić M, Nedović V, Bugarski B. Modeling of microenvironmetal restricted yeast cell growth within Ca-alginate microbead. in Minerva Biotecnologica. 2008;20(2):99-102.
https://hdl.handle.net/21.15107/rcub_agrospace_1638 .

Pajić-Lijaković, Ivana, Plavsić, M., Nedović, Viktor, Bugarski, Branko, "Modeling of microenvironmetal restricted yeast cell growth within Ca-alginate microbead" in Minerva Biotecnologica, 20, no. 2 (2008):99-102,
https://hdl.handle.net/21.15107/rcub_agrospace_1638 .

TY  - JOUR
AU  - Pajić-Lijaković, Ivana
AU  - Bugarski, Branko
AU  - Nedović, Viktor
AU  - Plavsić, M.
PY  - 2005
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/1102
AB  - Aim. The aggregation of phospholipid vesicles (liposomes) in water is analyzed experimentally and theoretically and compared with the well-examined alumina dispersions. The steady-state aggregation followed rheologically for various volume fractions of particles and shear rates. Methods. A micro-rheological model of aggregating dispersions is proposed in which the apparent viscosity is estimated as the sum of hydrodynamic and structural parts, which are correlated with system structural ordering. Langevin equation is used to describe the dynamics of evolution of steady-states of liposome systems in phase space, for various shear rates. Results. These results established a link between the local dynamics of liposome dispersions and their flow behavior. Conclusion. Aggregates become more compact and embedded higher volume of fluid when shear rate increases. Hydrodynamic part of viscosity increases, while structural part of viscosity decreases with shear rate. Calculated value of bond energy between liposomes corresponds to hydrogen bond energy.
PB  - Edizioni Minerva Medica, Turin
T2  - Minerva Biotecnologica
T1  - Rheological quantification of liposomes aggregation
EP  - 249
IS  - 4
SP  - 245
VL  - 17
UR  - https://hdl.handle.net/21.15107/rcub_agrospace_1102
ER  - 

@article{
author = "Pajić-Lijaković, Ivana and Bugarski, Branko and Nedović, Viktor and Plavsić, M.",
year = "2005",
abstract = "Aim. The aggregation of phospholipid vesicles (liposomes) in water is analyzed experimentally and theoretically and compared with the well-examined alumina dispersions. The steady-state aggregation followed rheologically for various volume fractions of particles and shear rates. Methods. A micro-rheological model of aggregating dispersions is proposed in which the apparent viscosity is estimated as the sum of hydrodynamic and structural parts, which are correlated with system structural ordering. Langevin equation is used to describe the dynamics of evolution of steady-states of liposome systems in phase space, for various shear rates. Results. These results established a link between the local dynamics of liposome dispersions and their flow behavior. Conclusion. Aggregates become more compact and embedded higher volume of fluid when shear rate increases. Hydrodynamic part of viscosity increases, while structural part of viscosity decreases with shear rate. Calculated value of bond energy between liposomes corresponds to hydrogen bond energy.",
publisher = "Edizioni Minerva Medica, Turin",
journal = "Minerva Biotecnologica",
title = "Rheological quantification of liposomes aggregation",
pages = "249-245",
number = "4",
volume = "17",
url = "https://hdl.handle.net/21.15107/rcub_agrospace_1102"
}

Pajić-Lijaković, I., Bugarski, B., Nedović, V.,& Plavsić, M.. (2005). Rheological quantification of liposomes aggregation. in Minerva Biotecnologica
Edizioni Minerva Medica, Turin., 17(4), 245-249.
https://hdl.handle.net/21.15107/rcub_agrospace_1102

Pajić-Lijaković I, Bugarski B, Nedović V, Plavsić M. Rheological quantification of liposomes aggregation. in Minerva Biotecnologica. 2005;17(4):245-249.
https://hdl.handle.net/21.15107/rcub_agrospace_1102 .

Pajić-Lijaković, Ivana, Bugarski, Branko, Nedović, Viktor, Plavsić, M., "Rheological quantification of liposomes aggregation" in Minerva Biotecnologica, 17, no. 4 (2005):245-249,
https://hdl.handle.net/21.15107/rcub_agrospace_1102 .