An electrochemical method for measurement of mass transport in polymer membranes using acetaminophen as a model system

2009 ◽  
Vol 54 (22) ◽  
pp. 4949-4953 ◽  
Author(s):  
Zimei Rong ◽  
Pankaj Vadgama
2007 ◽  
Vol 19 (18) ◽  
pp. 2672-2676 ◽  
Author(s):  
A. A. Gusev ◽  
O. Guseva

2017 ◽  
Vol 40 (4) ◽  
pp. 185-195 ◽  
Author(s):  
Hadis Eghbali ◽  
Michele M. Nava ◽  
Gabriella Leonardi ◽  
Davod Mohebbi-Kalhori ◽  
Roberto Sebastiano ◽  
...  

Introduction Perfused bioreactors have been demonstrated to be effective in the delivery of nutrients and in the removal of waste products to and from the interior of cell-populated three-dimensional scaffolds. In this paper, a perfused bioreactor hosting a macroporous scaffold provided with a channel is used to investigate transport phenomena and culture parameters on cell growth. Methods MG63 human osteosarcoma cells were seeded on macroporous poly(ε-caprolactone) scaffolds provided with a channel. The scaffolds were cultured in a perfused bioreactor and in static conditions for 5 days. Cell viability and growth were assessed while the concentration of oxygen, glucose and lactate were measured. An in silico, multiphysics, numerical model was set up to study the fluid dynamics and the mass transport of the nutrients in the perfused bioreactor hosting different scaffold geometries. Results The experimental and numerical results indicated that the specific cell metabolic activity in scaffolds cultured under perfusion was 30% greater than scaffolds cultured under static conditions. In addition, the scaffold provided with a channel enabled the shear stress to be controlled, the initial seeding density to be retained, and adequate mass transport and waste removal. Conclusions We show that the macroporous scaffold provided with a channel cultured in a macroscale bioreactor can be a robust reference experimental model system to systematically investigate and assess crucial culture parameters. We also show that such an experimental model system can be employed as a simplified “representative unit” to improve the performance of both perfused culture systems and hollow, fiber-integrated scaffolds for large-scale tissue engineering.


1989 ◽  
Vol 159 ◽  
Author(s):  
Stuart Mckernan ◽  
C. Barry Carter ◽  
Daniel Ricoult ◽  
A. G. Cullis

ABSTRACTThe oxidation of iron-rich olivine to produce magnetite is a model system for the study of phase transitions involving mass transport. High-resolution lattice images of have been obtained from magnetite precipitates in naturally modified iron-rich olivines. The magnetite/olivine interface is shown to be extremely sharp. Steps and misfit dislocations are present at the interface.


RSC Advances ◽  
2015 ◽  
Vol 5 (48) ◽  
pp. 38223-38234 ◽  
Author(s):  
Sina Nabati Shoghl ◽  
Ahmadreza Raisi ◽  
Abdolreza Aroujalian

The NELF model was used for estimating gas sorption in non-equilibrium glassy polymers and a predictive mass transfer model was developed.


1979 ◽  
Vol 44 ◽  
pp. 349-355
Author(s):  
R.W. Milkey

The focus of discussion in Working Group 3 was on the Thermodynamic Properties as determined spectroscopically, including the observational techniques and the theoretical modeling of physical processes responsible for the emission spectrum. Recent advances in observational techniques and theoretical concepts make this discussion particularly timely. It is wise to remember that the determination of thermodynamic parameters is not an end in itself and that these are interesting chiefly for what they can tell us about the energetics and mass transport in prominences.


Author(s):  
D. C. Williams ◽  
D. E. Outka

Many studies have shown that the Golgi apparatus is involved in a variety of synthetic activities, and probably no Golgi product is more elaborate than the scales produced by various kinds of phytoflagellates. The formation of calcified scales (coccoliths, Fig. 1,2) of the coccolithophorid phytoflagellates provides a particularly interesting model system for the study of biological mineralization, and the sequential formation of Golgi products.The coccoliths of Hymenomonas carterae consist of a scale-like base (Fig. 2 and 4, b) with a highly structured calcified (CaCO3) rim composed of two distinct elements which alternate about the base periphery (Fig. 1 and 3, A, B). Each element is enveloped by a sheath-like organic matrix (Fig. 3; Fig. 4, m).


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