scholarly journals MASS TRANSFER IN FERMENTATION PROCESSES

2018 ◽  
Vol 12 (1) ◽  
Author(s):  
A. Shevchenko ◽  
A. Sokolenko ◽  
O. Stepanets ◽  
O. Bilyk
Keyword(s):  
Mass Transfer ◽  
Liquid Phase ◽  
Culture Media ◽  
Anaerobic Fermentation ◽  
Superposition Principle ◽  
Cumulative Effect ◽  
Unsaturation Index ◽  
Yeast Cells ◽  
Fermentation Processes ◽  
The Media

The peculiarities of anaerobic fermentation processes with the accumulation of dissolved ethyl alcohol and carbon dioxide in the culture media are considered in the article.The solubility of CO2 is limited by the state of saturation in accordance with Henry’s law. This, with all else being equal, limits the mass transfer on the interface surface of yeast cells and the liquid phase of the medium. A phenomenological model of the media restoration technologies based on the unsaturation index on СО2 is developed. It is shown that this restoration in the existing technologies of fermentation of sugar-rich media occurs, to a limited extent, in self-organized flow circuits, with variable values of temperatures and hydrostatic pressures, due to the creation of unsaturated local zones.It is shown that increasing the height of the media in isovolumetric apparatuses leads to an increase in the levels of flow circuits organization and to the improvement of the desaturation and saturation modes of the liquid phase and intensification of mass transfer processes. Among the deterministic principles of restoring the saturation possibilities of the media, there are forced variables of pressures with time pauses on their lower and upper levels. In such cases, the possibilities of short-term intensive desaturations in full media volumes, the restoration of their saturation perception of CO2, and the activation of fermentation processes are achieved. This direction is technically feasible for active industrial equipment.The cumulative effect of the action of variable pressures and temperatures corresponds to the superposition principle, but at the final stages of fermentation, the pressure and temperature values are leveled, so the restoration of the unsaturation state slows down to the level of the bacteriostatic effect. The possibility of eliminating the disadvantages of the final stage of fermentation by means of programmable variable pressures is shown

Modeling of aerated upflow fixed bed reactors for nitrification

1999 ◽  
Vol 39 (4) ◽  
pp. 85-92 ◽  
Author(s):  
J. Behrendt
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Liquid Phase ◽  
Gas Phase ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Bulk Liquid ◽  
Initial Value ◽  
Fixed Bed Reactors ◽  
Number Of Cells

A mathematical model for nitrification in an aerated fixed bed reactor has been developed. This model is based on material balances in the bulk liquid, gas phase and in the biofilm area. The fixed bed is divided into a number of cells according to the reduced remixing behaviour. A fixed bed cell consists of 4 compartments: the support, the gas phase, the bulk liquid phase and the stagnant volume containing the biofilm. In the stagnant volume the biological transmutation of the ammonia is located. The transport phenomena are modelled with mass transfer formulations so that the balances could be formulated as an initial value problem. The results of the simulation and experiments are compared.

Heat and mass transfer during growth of a spherical particle from the liquid phase

1979 ◽  
Vol 37 (6) ◽  
pp. 1389-1393
Author(s):  
A. N. Verigin ◽  
I. A. Shchuplyak ◽  
M. F. Mikhalev ◽  
V. V. Varentsov
Keyword(s):  
Mass Transfer ◽  
Liquid Phase ◽  
Spherical Particle ◽  
Heat And Mass Transfer

scholarly journals The Roles of Porous Coral Sands in Initial Enrichment of Ammonia-Oxidizing Bacteria

2007 ◽  
Vol 7 ◽  
pp. 525-532
Author(s):  
Qing Guo ◽  
Zao-he Wu ◽  
Ming-liang Qian ◽  
Binhe Gu
Keyword(s):  
Culture Media ◽  
Potassium Dihydrogen Phosphate ◽  
N:P Ratio ◽  
Ammonium Nitrogen ◽  
Dihydrogen Phosphate ◽  
Ammonia Oxidizing Bacteria ◽  
Potassium Dihydrogen ◽  
Conversion Rates ◽  
Calcium Source ◽  
The Media

The purpose of this study was to investigate the roles of coral sands in the enrichment and isolation of ammonium-oxidizing bacteria (AOB). We hypothesized that the porous coral sands provided additional surface area and nutrients for the growth of periphytic AOB. In the present study, an orthogonal test was designed to compare the AOB conversion rates of ammonium-nitrogen (NH4+N) to nitrite-nitrogen (NO2--N) among various combinations of culture media. Results showed that the conversion of NH4+N to NO2--N increased significantly when the coral sands were added, implying that coral sands were beneficial to the growth of AOB. Additions of potassium dihydrogen phosphate (KH2PO4) or sodium bicarbonate (NaHCO3) to the media became unnecessary when coral sands were used, but the addition of KH2PO4was needed when the molar nitrogen to phosphorus (N:P) ratio reached 10 in the enrichment media using calcium carbonate (CaCO3) powder as a calcium source.

Thermal convection in melting zone of hollow microparticle Al2O3

2021 ◽  
pp. 20-25
Author(s):  
V.V. Shekhovtsov ◽  
◽  
YU.A. Abzaev ◽  
O.G. Volokitin ◽  
A.A. Klopotov ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Numerical Modeling ◽  
Liquid Phase ◽  
Heat And Mass Transfer ◽  
Convective Heat ◽  
Thermal Convection ◽  
Melting Zone ◽  
Melting Front ◽  
Α Al2o3 ◽  
Inner Region

The paper presents the results of numerical modeling of development melting zone hollow spherical microparticle α-Al2O3. The object of the study was part circular sector, which represents the shell of hollow particle, which is formed under action plasma flow. Numerically describe the unsteady convective heat and mass transfer in shell hollow particle, we used the system Navier-Stokes equations in Boussinesq approximation, which describes the weak convection medium. Due to the high coefficient of porosity (P = 0.56) initial agglomerated particle with the α-Al2O3 structure, the inner region at the stage of heating Tp ≥ Tmelt is in the conditions heat exchange with the incoming heat flux, as result of which the temperature center coincided with the temperature particle surface. Result of overheating of the condensed phase, liquid layer of fused grains is formed in the inner and outer regions microparticle. In this case, the melting front is directed towards center shell. Result of numerical modeling, it has been established that convective heat and mass transfer is observed in melting zones (liquid phase), vector field of which covers almost the entire region of the liquid phase. It was found that thermal convection in the external liquid phase is characterized by velocities that are more than 2 times higher than the displacement velocity in the inner region of the particle. It is shown that there is no displacement of the material inside the convection region, thereby inhomogeneous heating occurs in the molten layer of the particle, which significantly affects the speed of movement of the melting front.

Biochemical markers for pregnancy in the spent culture medium of in vitro produced bovine embryos

2021 ◽  
Author(s):  
Gabriela de Oliveira Fernandes ◽  
Marcella Pecora Milazzotto ◽  
Andrei Antonioni Guedes Fidelis ◽  
Taynan Stonoga Kawamoto ◽  
Ligiane de Oliveira Leme ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Biochemical Markers ◽  
Culture Medium ◽  
Culture Media ◽  
Ionization Mass ◽  
Metabolic Profiles ◽  
Bovine Embryos ◽  
The Media

Abstract The present study aimed to identify biomarkers to assess the quality of in vitro produced (IVP) bovine embryos in the culture media. IVP embryos on Day (D) 5 of development were transferred to individual drops, where they were maintained for the last 48 h of culture. Thereafter, the medium was collected and the embryos were transferred to the recipients. After pregnancy diagnosis, the media were grouped into the pregnant and nonpregnant groups. The metabolic profiles of the media were analyzed via electrospray ionization mass spectrometry, and the concentrations of pyruvate, lactate, and glutamate were assessed using fluorimetry. The spectrometric profile revealed that the media from embryos from the pregnant group presented a higher signal intensity compared to that of the nonpregnant group; the ions 156.13 Da [M + H]+, 444.33 Da [M + H]+, and 305.97 Da [M + H]+ were identified as biomarkers. Spent culture medium from expanded blastocysts (Bx) that established pregnancy had a greater concentration of pyruvate (p = 0.0174) and lesser concentration of lactate (p = 0.042) than spent culture medium from Bx that did not establish pregnancy. Moreover, pyruvate in the culture media of Bx can predict pregnancy with 90.9% sensitivity and 75% specificity. In conclusion, we identified markers in the culture media that helped in assessing the most viable IVP embryos with a greater potential to establish pregnancy.

scholarly journals The Role of Sequestrene 138 in Highbush Blueberry (Vaccinium corymbosum L.) Micropropagation

HortScience ◽  
2018 ◽  
Vol 53 (10) ◽  
pp. 1487-1493 ◽  
Author(s):  
Doina Clapa ◽  
Claudiu Bunea ◽  
Orsolya Borsai ◽  
Adela Pintea ◽  
Monica Hârța ◽  
...  
Keyword(s):  
Culture Media ◽  
Iron Concentration ◽  
Vaccinium Corymbosum ◽  
Carotenoid Content ◽  
Free Medium ◽  
Axillary Shoots ◽  
Different Types ◽  
The Media ◽  
Dark Green

The current research was carried out to investigate the effects of iron source in the culture media for Vaccinium corymbosum L. ʻBluerayʼ, ʻDukeʼ, and ʻPatriotʼ cultivars grown on five different types of medium (Woody Plant Medium supplemented with 1.0 mg·L−1 zeatin and 0, 25, 50, 75, and 100 mg·L−1 Sequestrene 138). After 10 weeks of culture, seven physiological parameters were measured, such as the number and length of axillary shoots, rooting and acclimatization percentage, as well as chlorophyll (a, b, a/b) and carotenoid content of the leaves. Adding Sequestrene 138 to the culture media led to a slight decrease of the proliferation rate but increased the length of the shoots. The chlorophyll and carotenoid content in all of the three cultivars was considerably increased as the iron concentration of the media increased. The shoots developed on the Sequestrene 138–free medium were chlorotic and short, whereas at different concentrations of iron in the culture medium the shoots were dark green and vigorous, providing a greater acclimatization success than those grown in iron-free medium.

Mass transfer in the liquid phase during the formation of bubbles

1966 ◽  
Vol 21 (8) ◽  
pp. 719-721 ◽  
Author(s):  
P.H. Calderbank ◽  
R.P. Patra
Keyword(s):  
Mass Transfer ◽  
Liquid Phase

scholarly journals Catalyst characterization in the presence of solvent: development of liquid phase structure–activity relationships

2018 ◽  
Vol 9 (2) ◽  
pp. 281-287 ◽  
Author(s):  
Nicholas S. Gould ◽  
Bingjun Xu
Keyword(s):  
Mass Transfer ◽  
Liquid Phase ◽  
Phase Structure ◽  
Catalyst Surface ◽  
Catalyst Characterization ◽  
Structure Activity Relationships ◽  
Structure Activity

Due to the low volatility and highly oxygenated nature of biomass derived feedstocks, biomass upgrade reactions are frequently conducted in the presence of solvent to improve substrate mass transfer to the catalyst surface.

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