FLUID-MECHANICAL DAMAGE OF FREELY-SUSPENDED ANIMAL CELLS IN AGITATED BIOREACTORS: EFFECTS OF DEXTRAN, DERIVATIZED CELLULOSES AND POLYVINYL ALCOHOL

The use of polyvinyl alcohol (PVA) as a matrix for cell immobilization has been extensively studied in various biological systems. However, its suitability has not been reported in biosorption studies where inactivated cells are used as biosorbents. In this work, PVA and alginate as immobilization matrices (for the biosorption of gold by a fungal biomass) were investigated by examining their physical and chemical properties. Compared to alginate gels, PVA gels were shown to be more resistant to mechanical abrasion, and more stable over a wide pH range. Although the PVA matrix did not affect the equilibrium uptake in gold biosorption studies, the time required to attain a removal of 80% of the initial metal concentration was 1.7 times that of the freely suspended biosorbent. This contrasts with the alginate immobilized biosorbent which required an increase of well over ten times the duration to attain the same removal efficiency. Results indicated that PVA gels conferred a lower mass transfer resistance than alginate gels. Gold biosorption by the PVA-immobilized fungi followed the commonly used Langmuir and Freundlich adsorption isotherm models although the former gave a better fit. The uptake of gold was dependent on the initial gold concentration and the biomass loading. Using a fungal biosorbent and gold ions as the model system, the results demonstrate the potential in the use of the PVA as a cell immobilisation matrix for biosorption studies.

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A study of the natural vibratory response of stator structures to improve condition monitoring strategies for induction motors

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/0954406981521042 ◽

1998 ◽

Vol 212 (1) ◽

pp. 57-68 ◽

Cited By ~ 2

Author(s):

M Lucas ◽

W T Thomson

Keyword(s):

Condition Monitoring ◽

Induction Motors ◽

Mechanical Damage ◽

Vibration Monitoring ◽

Stator Core ◽

Realistic Condition ◽

Vibratory Response ◽

Insulation Degradation ◽

On Line ◽

Freely Suspended

On-line condition monitoring is widely used to detect failure mechanisms in large highvoltage three-phase induction motors. The high-voltage winding is installed in a complex, stator core structure which vibrates due to electromagnetic forces. Insulation degradation can be diagnosed via on-line monitoring of partial discharges but the fundamental cause is often mechanical damage due to stator vibration. This paper presents results of an investigation into the natural vibratory response of the complete stator assembly. Results from finite element models of complex stator assemblies, including the frames, are supported by experimental measurements. These include freely suspended stator cores as in previous studies, and also now introduce the much more realistic condition of the complete stator assembly securely bolted on to a solid baseplate. The knowledge gathered in this study will aid the application of a vibration monitoring strategy to detect stator core vibration which can lead to winding insulation damage.

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Biodegradation of aniline by freely suspended and immobilized Pseudomonas moraviensis AN-5

TAP CHI SINH HOC ◽

10.15625/0866-7160/v39n3.9630 ◽

2017 ◽

Vol 39 (3) ◽

pp. 303-308

Author(s):

Ha Danh Duc ◽

Bui Minh Triet

Keyword(s):

Polyvinyl Alcohol ◽

Nitrogen Source ◽

Polyurethane Foam ◽

Immobilized Cells ◽

Initial Concentration ◽

Carbon And Nitrogen ◽

Freely Suspended ◽

Suspended Cells ◽

Better Than

Pseudomonas moraviensis AN-5 isolated from contaminated sludge could utilize aniline as a sole carbon and nitrogen source. The aniline degradation by cells immobilized in alginate, polyvinyl alcohol (PVA) and polyurethane foam (PUF) was significantly better than freely suspended cells. The immobilized AN-5 degraded aniline nearly completely at the initial concentration of 22 mM by 48 hr of incubation. Compared to other binding materials, PUF-immobilized cells were more stable in aniline biodegradation in reused cycles. Moreover, immobilized cells could be stored for three months at 4oC with little reduction of the aniline degradation capacity. These results revealed that PUF-immobilized P. moraviensis AN-5cells has enhanced aniline biodegradation activity. Citation: Ha Danh Duc, Bui Minh Triet, 2017. Biodegradation of aniline by freely suspended and immobilized Pseudomonas moraviensis AN-5. Tap chi Sinh hoc, 39(3): 303-308. DOI: 10.15625/0866-7160/v39n3.9630. *Corresponding author: [email protected] Received 11 April 2017, accepted 20 August 2017

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Prediction of mechanical damage to animal cells in turbulence

Cytotechnology ◽

10.1007/bf00762408 ◽

1994 ◽

Vol 15 (1-3) ◽

pp. 329-335 ◽

Cited By ~ 19

Author(s):

C. R. Thomas ◽

M. Al-Rubeai ◽

Z. Zhang

Keyword(s):

Mechanical Damage ◽

Animal Cells

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