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Number of results: 9
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Abstract

The effect of rotating magnetic field on the heat transfer process in a magnetically assisted bioreactor was studied experimentally. Experimental investigations are provided for the explanation of the influence of the rotating magnetic field on natural convection. The heat transfer coefficients and the Nusselt numbers were determined as a function of the product of Grashof and Prandtl dimensionless numbers. Moreover, the comparison of the thermal performance between the tested set-up and a vertical cylinder was carried out. The relative enhancement of heat transfer was characterized by the rate of the relative heat transfer intensification. The study showed that along with the intensity of the magnetic field the heat transfer increased.

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Authors and Affiliations

Maciej Konopacki
Marian Kordas
Rafał Rakoczy
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Abstract

In this study, batch fermentation of glucose to ethanol by Saccharomyces cerevisiae (ATCC 7754) was carried out using 2.5 dm3 BioFlo®115 bioreactor. The main objective of this study was to investigate the kinetics of ethanol fermentation by means of the non-structured model. The fermentation process was carried out for 72 h. Samples were collected every 4 h and then yeast growth concentration of ethanol and glucose were measured. The mathematical model was composed of three equations, which represented the changes of biomass, substrate and ethanol concentrations. The mathematical model of bioprocess was solved by means of Matlab/SimulinkTM environment. The obtained results from the proposed model showed good agreement with the experimental data, thus it was concluded that this model can be used for the mathematical modeling of ethanol production.

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Authors and Affiliations

Anna Konopacka
Maciej Konopacki
Marian Kordas
Rafał Rakoczy
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Abstract

The main aim of this work is to study the thermal efficiency of a new type of a static mixer and to analyse the flow and temperature patterns and heat transfer efficiency. The measurements were carried out for the static mixer equipped with a new mixing insert. The heat transfer enhancement was determined by measuring the temperature profiles on each side of the heating pipe as well as the temperature field inside the static mixer. All experiments were carried out with varying operating parameters for four liquids: water, glycerol, transformer oil and an aqueous solution of molasses. Numerical CFD simulations were carried out using the two-equation turbulence k-ω model, provided by ANSYS Workbench 14.5 software. The proposed CFD model was validated by comparing the predicted numerical results against experimental thermal database obtained from the investigations. Local and global convective heat transfer coefficients and Nusselt numbers were detrmined. The relationship between heat transfer process and hydrodynamics in the static mixer was also presented. Moreover, a comparison of the thermal performance between the tested static mixer and a conventional empty tube was carried out. The relative enhancement of heat transfer was characterised by the rate of relative heat transfer intensification.

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Authors and Affiliations

Maciej Konopacki
Marian Kordas
Karol Fijałkowski
Rafał Rakoczy
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Abstract

The main objective of these experiments was to study the oxygen mass transfer rate through the volumetric mass transfer coefficient (kLa) for an experimental set-up equipped with a rotating magnetic field (RMF) generator and various liquids. The experimental results indicated that kLa increased along the magnetic strength and the superficial gas velocity. Mathematical correlations defining the influence of the considered factors on kLa were proposed.

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Authors and Affiliations

Rafał Rakoczy
Maciej Konopacki
Marian Kordas
Radosław Drozd
Karol Fijałkowski
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Abstract

The aim of the study was to present an experimental investigation of the influence of the RMF on mixing time. The obtained results suggest that the homogenization time for the tested experimental set-up depending on the frequency of the RMF can be worked out by means of the relationship between the dimensionless mixing time number and the Reynolds number. It was shown that the magnetic field can be applied successfully to mixing liquids.

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Authors and Affiliations

Alicja Przybył
Rafał Rakoczy
Maciej Konopacki
Marian Kordas
Radosław Drozd
Karol Fijałkowski
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Abstract

The practical applications of bacteriophages are associated with the problems related to the intensification, optimization of process production of this biomaterial and the search for new methods of production. The production of bacteriophages requires a fine balance between the dynamic growth of the bacteriophage and the host. The electromagnetic field (EMF) is a promising biotechnological method for the process production of bacteriophages. This study evaluates the use of various types of EMF to enhance the process. It was found that the process production of bacteriophages is divided into two stages. In the first stage, the influence of various types of EMF on the proliferation process of bacteria (host) was analyzed. Secondly, the process production of bacteriophage was implemented for the optimal infection conditions under the action of the various types of EMF. Moreover, the study demonstrated that the most effective bacteriophage production was the process with the application of the rotating magnetic field (RMF), pulsed magnetic field (PMF) and the static magnetic field (SMF) with negative polarity.
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Authors and Affiliations

Rafał Rakoczy
1
ORCID: ORCID
Maciej Konopacki
1 2
ORCID: ORCID
Marian Kordas
1
ORCID: ORCID
Bartłomiej Grygorcewicz
2
ORCID: ORCID

  1. West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, Department of Chemical and Process Engineering, al. Piastów 42,71-065 Szczecin, Poland
  2. Pomeranian Medical University in Szczecin, Chair of Microbiology, Immunology and Laboratory Medicine, Department of Laboratory Medicine, al. Powstanców Wielkopolskich 72, 70-111 Szczecin, Poland
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Abstract

Bacteriophages, viruses that can infect bacteria, are promising alternatives for antibiotic treatment caused by antibiotic-resistant bacteria strains. For that reason, the production of bacteriophages is extensively studied. Mathematical modelling can lead to the improvement of bioprocess by identification of critical process parameters and their impact on the demanded product. Dynamic modelling considers a system (i.e. bioreactor or bioprocess) as a dynamic object focusing on changes in the initial and final parameters (such as biomass concentration and product formation) in time, so-called signals and treats the studied system as a “black box” that processes signals. This work aimed to develop a mathematical model that describes bacteriophage production process. As result, we created a dynamic model that can estimate the number of bacteriophages released from cells as plaque-forming units at specific time points based on the changes in the bacteria host-cell concentration. Moreover, the proposed model allowed us to analyze the impact of the initial virus concentration given by multiplicity of infection (MOI) on the amount of produced bacteriophages.
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Authors and Affiliations

Maciej Konopacki
1 2
ORCID: ORCID
Bartłomiej Grygorcewicz
1 2
ORCID: ORCID
Marta Gliźniewicz
2
ORCID: ORCID
Dominika Miłek
2
ORCID: ORCID
Marian Kordas
1
ORCID: ORCID
Rafał Rakoczy
1
ORCID: ORCID

  1. West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, Department of Chemical and Process Engineering, al. Piastów 42, 71-065 Szczecin, Poland
  2. Pomeranian Medical University in Szczecin, Chair of Microbiology, Immunology and Laboratory Medicine, Department of Laboratory Medicine, al. Powstanców Wielkopolskich 72, 70-111 Szczecin, Poland
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Abstract

In recent years, infections are more often caused by pathogens with high multi-drug resistance, classified as the “ESKAPE” microorganisms. Therefore, investigation of these pathogens, e.g., Klebsiella pneumoniae, often requires biomass production for treatment testing such as antibiotics or bacteriophages. Moreover, K. pneumoniae can be successfully applied as a biocatalyst for other industrial applications, increasing the need for this bacteria biomass. In the current study, we proposed a novel magnetically assisted bioreactor for the cultivation of K. pneumoniae cells in the presence of an external alternating magnetic field (AMF). High efficiency of the production requires optimal bacteria growth conditions, e.g., temperature and field frequency. Therefore, we performed an optimization procedure using a central composite design for these two parameters in a wide range. As an objective function, we utilized a novel, previously described growth factor that considers both biomass and bacteria growth kinetics. Thus, based on the response surface, we could specify the optimal growth conditions. Moreover, we analysed the impact of the AMF on bacteria proliferation, which indicated positive field frequency windows, where the highest stimulatory effect of AMF on bacteria proliferation occurred. Obtained results proved that the magnetically assisted bioreactor could be successfully employed for K. pneumoniae cultivation.
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Authors and Affiliations

Maciej Konopacki
1 2
ORCID: ORCID
Adrian Augustyniak
1 3
ORCID: ORCID
Bartłomiej Grygorcewicz
1 2
ORCID: ORCID
Barbara Dołęgowska
2
ORCID: ORCID
Marian Kordas
1
ORCID: ORCID
Rafał Rakoczy
1
ORCID: ORCID

  1. West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, Department of Chemical and Process Engineering, al. Piastów 42, 71-065 Szczecin, Poland
  2. Pomeranian Medical University in Szczecin, Chair of Microbiology, Immunology and Laboratory Medicine, Department of Laboratory Medicine, al. Powstanców Wielkopolskich 72, 70-111 Szczecin, Poland
  3. Technische Universität Berlin, Building Materials and Construction Chemistry, Gustav-Meyer Allee 25,13355 Berlin, Germany
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Abstract

We demonstrate in this study that a rotating magnetic field (RMF) and spinning magnetic particles using this kind of magnetic field give rise to a motion mechanism capable of triggering mixing effect in liquids. In this experimental work two mixing mechanisms were used, magnetohydrodynamics due to the Lorentz force and mixing due to magnetic particles under the action of RMF, acted upon by the Kelvin force. To evidence these mechanisms,we report mixing time measured during the neutralization process (weak acid-strong base) under the action of RMF with and without magnetic particles. The efficiency of the mixing process was enhanced by a maximum of 6.5% and 12.8% owing to the application of RMF and the synergistic effect of magnetic field and magnetic particles, respectively.
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Bibliography

Baldyga J., Bourne J.R., 1988. Calculation of micromixing in inhomogenous stirred tank reactors. Chem. Eng. Res. Des., 66(1), 33–38.

Baldyga J., Bourne J.R., 1992. Interactions between mixing on various scales in stirred tank reactors. Chem. Eng. Sci., 47, 1839–1848. DOI: 10.1016/0009-2509(92)80302-S.

Bałdyga J., Pohorecki R., 2013. Editorial. 14th European Conference on Mixing. Chem. Eng. Res. Des., 91(11), 2071–2072). DOI: 10.1016/j.cherd.2013.10.021.

Bao S.R., Zhang R.P., Rong Y., Zhi X.Q., Qiu L.M., 2019. Interferometric study of the heat and mass transfer during the mixing and evaporation of liquid oxygen and nitrogen under non-uniform magnetic field. Int. J. Heat Mass Transfer, 136, 10–19. DOI: 10.1016/j.ijheatmasstransfer.2019.02.044.

Boroun S., Larachi F., 2016. Role of magnetic nanoparticles in mixing, transport phenomena and reaction engineering – challenges and opportunities. Curr. Opin. Chem. Eng., 13, 91–99. DOI: 10.1016/j.coche.2016.08.011.

Boulware J.C., Ban H., Jensen, S., Wassom S., 2010. Influence of geometry on liquid oxygen magnetohydrodynamics. Exp. Therm Fluid Sci., 34, 1182–1193. DOI: 10.1016/j.expthermflusci.2010.04.007.

Chen X., Zhang L., 2019. A review on micromicers acuated with magnetic nanomaterials. Microchim Acta, 184, 3639–3649. DOI: 10.1007/s00604-017-2462-2.

Davidson P.A., 1999. Magnetohydrodynamics in materials processing. Annu. Rev. Fluid Mech., 31, 273–300. DOI: 10.1146/annurev.fluid.31.1.273.

Davidson P.A., 2001. An introduction to magnetohydrodynamics. Cambridge Uniwversity Press. DOI: 10.1017/CBO9780511626333.

Ergin F.G.,Watz B.B., Erglis K., Cebers A., 2015. Time-resolved velocity measurements in a magnetic micromixer. Exp. Therm Fluid Sci., 67. DOI: 10.1016/j.expthermflusci.2015.02.019.

Gao Y., 2013. Active mixing and catching using magnetic particles. Phd Thesis. Technische Universiteit Eindhoven. DOI: 10.6100/IR759475.

Gopalakrishnan S., Thess A., 2010. Chaotic mixing in electromagnetically controlled thermal convection of glass melt. Chem. Eng. Sci., 65, 5309–5319. DOI: 10.1016/j.ces.2010.07.008.

Hajiani P., Larachi F., 2014. Magnetic-field assisted mixing of liquids using magnetic nanoparticles. Chem. Eng. Process., 84, 31–37. DOI: 10.1016/j.cep.2014.03.012.

Hajiani P, Larachi F., 2013. Remotely excited magnetic nanoparticles and gas–liquid mass transfer in Taylor flow regime. Chem. Eng. Sci., 93, 257–265. DOI: 10.1016/j.ces.2013.01.052.

Hao Z., Zhu Q., Jiang Z., Li H., 2008. Fluidization characteristics of aerogel Co/Al2O3 catalyst in a magnetic fluidized bed and its application to CH4-CO2 reforming. Powder Technol., 183, 46–52. DOI: 10.1016/j.powtec.2007.11.015.

Harnby N., Edwards M.F., Nienow A.W., 1985. Mixing in the process industries. Butterworth-Heinemann. DOI: 10.1016/b978-0-7506-3760-2.x5020-3.

Hausmann R., Reichert C., Franzreb M., HöllW.H., 2004. Liquid-phase mass transfer of magnetic ion exchangers in magnetically influenced fluidized beds: II. AC fields. React. Funct. Polym., 60, 17–26. DOI: 10.1016/j.reactfunct polym.2004.02.007.

Hristov J., 2002. Magnetic field assisted fluidization – a unified aproach Part 1. Fundamentals and relevant hydrodynamics of gas-fluidized beds (batch solids mode). Rev. Chem. Eng., 18, 295–512. DOI: 10.1515/REVCE.2002.18.4-5.295.

Hristov J., 2007. Magnetic field assisted fluidization-Dimensional analysis addressing the physical basis. China Particuology, 5, 103–110. DOI: 10.1016/j.cpart.2007.03.002.

Hristov J., 2010. Magnetic field assisted fluidization – A unified approach. Part 8. Mass transfer: Magnetically assisted bioprocesses. Rev. Chem. Eng., 26, 55–128. DOI: 10.1515/REVCE.2010.006.

Hristov J.Y., 1998. Fluidization of ferromagnetic particles in a magnetic field Part 2: Field effects on preliminarily gas fluidized bed. Powder Technol., 97, 35–44. DOI: 10.1016/S0032-5910(97)03392-5.

Krakov M.S., 2020. Mixing of miscible magnetic and non-magnetic fluids with a rotating magnetic field. J. Magn. Magn. Mater., 498. DOI: 10.1016/j.jmmm.2019.166186.

Lange A., 2002.Kelvin force in a layer of magnetic fluid. J. Magn. Magn. Mater., 241, 327–329. DOI: 10.1016/S0304 -8853(01)01368-3.

Lu X., Li H., 2000. Fluidization of CaCO3 and Fe2O3 particle mixtures in a transverse rotating magnetic field. Powder Technol., 107, 66–78. DOI: 10.1016/S0032-5910(99)00092-3.

Moffatt H.K., 1965. On fluid flow induced by a rotating magnetic field. J. Fluid Mech., 22, 521–528. DOI: 10.1017/S0022112065000940.

Moffatt H.K., 1990. On the behaviour of a suspension of conducting particles subjected to a time-periodic magnetic field. J. Fluid Mech., 218, 509–529. DOI: 10.1017/S0022112090001094.

Moffatt H.K., 1991. Electromagnetic stirring. Phys. Fluids A, 3, 1336–1343. DOI: 10.1063/1.858062.

Molokov S., Moreau R., Moffat H.K., 2007. Magnetohydrodynamics. Historical evolution and trends. Springer Science+Business Media B.V. DOI: 10.1007/978-1-4020-4833-3.

Nouri D., Zabihi-Hesari A., Passandideh-Fard M., 2017. Rapid mixing in micromixers using magnetic field. Sens. Actuators, A, 255, 79–86. DOI: 10.1016/j.sna.2017.01.005.

Olivier G., Pouya H., Fadçal L., 2014. Magnetically induced agitation in liquid–liquid–magnetic nanoparticle emulsions: Potential for process intensification. AIChE J., 60, 1176–1181. DOI: 10.1002/AIC.14331.

Penchev I.P., Hristov J.Y., 1990. Fluidization of beds of ferromagnetic particles in a transverse magnetic field. Powder Technol., 62, 1–11. DOI: 10.1016/0032-5910(90)80016-R.

Poulsen B.R., Iversen J.J.L., 1997. Mixing determinations in reactor vessels using linear buffers. Chem. Eng. Sci., 52, 979–984. DOI: 10.1016/S0009-2509(96)00466-6.
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Authors and Affiliations

Rafał Rakoczy
1
ORCID: ORCID
Marian Kordas
1
ORCID: ORCID
Agata Markowska-Szczupak
1
ORCID: ORCID
Maciej Konopacki
1
ORCID: ORCID
Adrian Augustyniak
1
ORCID: ORCID
Joanna Jabłońska
1
Oliwia Paszkiewicz
1
ORCID: ORCID
Kamila Dubrowska
1
Grzegorz Story
1
Anna Story
1
Katarzyna Ziętarska
1
Dawid Sołoducha
1
Tomasz Borowski
1
Marta Roszak
2
Bartłomiej Grygorcewicz
2
ORCID: ORCID
Barbara Dołęgowska
2
ORCID: ORCID

  1. West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, Department of Chemical and Process Engineering, al. Piastów 42,71-065 Szczecin, Poland
  2. Pomeranian Medical University in Szczecin, Chair of Microbiology, Immunology and Laboratory Medicine, Department of Laboratory Medicine, al. Powstańców Wielkopolskich 72, 70-111 Szczecin, Poland

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