scholarly journals Analysis of experimental data on the kinetic characteristics of milk whey purification using ultrafiltration elements of BTU 05/2 type

2021 ◽  
Vol 82 (4) ◽  
pp. 88-94
Author(s):  
D. A. Rodionov ◽  
S. I. Lazarev ◽  
K. K. Polyansky ◽  
E. V. Eckert ◽  
D. L. Polushkin
Keyword(s):  
Experimental Data ◽  
Distribution Coefficient ◽  
Permeability Coefficient ◽  
Diffusion Permeability ◽  
Kinetic Characteristics ◽  
Membrane Material ◽  
Specific Flow ◽  
Milk Whey ◽  
Retention Coefficient ◽  
Coefficient Distribution

The paper presents the results of experimental data on the kinetic characteristics of ultrafiltration tubular elements, such as the output specific flow, retention coefficient, diffusion permeability coefficient, distribution coefficient. To study the purification of milk whey, we used tubular ultrafilters BTU 05/2 with membrane material fluoroplast (F), polyethersulfone (PESF), polysulfone (PS). For theoretical calculation of the retention coefficient, output specific flux, diffusion permeability coefficient, distribution coefficient, mathematical expressions were developed and empirical coefficients were obtained. The developed mathematical expression describes the experimental data with good reliability. The obtained experimental and calculated data can be used with high reliability in calculating mass-transfer fluxes of substances through a semi-permeable membrane, as well as in engineering methods for calculating and predicting efficiency, and using membrane processes for concentrating serum. The protein concentration in real milk whey was determined by formol titration. On the basis of the studies carried out, the dependence of the growth of the output specific flow on pressure was established, that the optimal pressure for concentrating milk whey on the ultrafiltration membranes we have chosen is 0.25 MPa. For three types of ultrafilters, the experimental value of the coefficient was within 99% for protein. For the theoretical calculation of the retention coefficient, a program in the MAXIMA language was developed and registered. Due to the method of applying the membrane to the reinforcing element, the membrane material polyethersulfone (PESF) and polysulfone (PS) have a substrate, due to which they sorb more substances on themselves, because of this, the diffusion permeability coefficient and the distribution coefficient are much higher than that of a filter element with membrane made of fluoroplastic (F), which does not have a substrate.

scholarly journals Ultrafiltration concentration of whey in a pilot plant

2019 ◽  
Vol 81 (2) ◽  
pp. 41-46
Author(s):  
D. A. Rodionov ◽  
S. I. Lazarev ◽  
K. K. Polyansky ◽  
E. V. Eckert
Keyword(s):  
Experimental Data ◽  
Calculated Data ◽  
General View ◽  
Specific Flow ◽  
Milk Whey ◽  
Retention Coefficient ◽  
Tubular Type ◽  
Specific Output ◽  
Output Stream ◽  
Mathematical Expressions

Experimental data on the retention coefficient and the output specific flow are obtained. The test solutions were goat and cow's milk whey after obtaining cheese. The description, general view and technological scheme of a pilot installation of a tubular type are given. The studies were carried out on semipermeable tubular type ultrafiltration membranes manufactured by AO "ZAVKOM". Based on the studies, graphical dependences of the retention coefficient on the specific output stream were constructed and analyzed. During the analysis, it was noted that with an increase in the output specific flow of the solvent, the retention coefficient decreases. The reason for this is the boundary layers of fat and protein formed in the near-membrane layers, which prevents the passage of protein molecules through the pores of the membrane. Also during the experiment, it was noted that goat milk serum has a more oily structure and requires prior separation. For the theoretical calculation of the retention coefficient and specific output stream, mathematical expressions are developed and numerical values of the values of empirical coefficients are obtained. The developed mathematical expressions describe the experimental data with good confidence. The obtained experimental and calculated data can be used with great reliability in the calculations of mass-transported flows of substances through semipermeable membranes, as well as in engineering methods for calculating and predicting the effectiveness of the use of membrane processes for the concentration of whey.

The Kinetics of Austenization Process of T91 Ferritic Heat-Resistant Steel

2011 ◽  
Vol 317-319 ◽  
pp. 42-47
Author(s):  
Li Fang Zhang ◽  
Yong Chang Liu
Keyword(s):  
Experimental Data ◽  
Phase Transformation ◽  
Kinetic Parameters ◽  
Nucleation And Growth ◽  
Transformation Model ◽  
Resistant Steel ◽  
Kinetic Characteristics ◽  
Heat Resistant Steel ◽  
Austenite Grain ◽  
Kinetics Of

By fitting the calculated transformed fraction according to developed phase-transformation model to the experimental data obtained by differential dilatometry, the kinetic characteristics of the austenitization process in T91 steels have been investigated. According to the kinetic parameters fitted, we recognize that the nucleation and growth of austenite grain are mainly controlled by the diffusion of carbon in ferritic and austenite respectively. In addition, by increasing the diffusion active energy of carbon in austenite, carbides hinder the motion of interface and thus refine austenite grain.

Colmatage naturel d'un milieu filtrant par les particules en suspension dans l'eau

1979 ◽  
Vol 6 (2) ◽  
pp. 243-252
Author(s):  
Marcel Frenette ◽  
Conrad Anctil
Keyword(s):  
Experimental Data ◽  
Porous Media ◽  
Suspended Sediment ◽  
Permeability Coefficient ◽  
General Study

This paper contains a general study on the natural clogging of porous media by suspended sediment in water. This creates with time a decrease in the permeability coefficient and consequently a reduction of the seepage flow.Two theories are presented and compared for the prediction of the rate of clogging in nature. The two approaches have been verified by experimental data obtained from tests carried out at Laval University. Results have permitted the limits of application of each method to be denned.

scholarly journals A New Modified Model of the Streaming Potential Coupling Coefficient Depends on Structural Parameters of Soil-Rock Mixture

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Xin Zhang ◽  
Mingjie Zhao ◽  
Kui Wang
Keyword(s):  
Experimental Data ◽  
Coupling Coefficient ◽  
Permeability Coefficient ◽  
Prediction Accuracy ◽  
Structural Parameters ◽  
Streaming Potential ◽  
Potential Effect ◽  
Structure Evolution ◽  
Embankment Dam ◽  
Modified Model

The streaming potential effect in soil-rock mixture (SRM) is related to the compactness and rock content, but there is no model to quantitatively describe this behavior. In this paper, the Kozeny–Carman (KC) equation is modified by using the compactness and rock content. Then, the modified KC equation is substituted into the equation of streaming potential coupling coefficient. A new modified model of streaming potential coupling coefficient that depends on the compactness, rock content, particle shape, and particle gradation is proposed. The reliability of the new modified model is tested by experiments, and the applicable scope of the model is obtained. The results show that when the rock content is 30%, the permeability coefficient prediction accuracy of the modified KC equation is higher in the range of 85–95% compactness. The new modified model of the streaming potential coupling coefficient represents well the control of the compactness (75–95%) on the coupling coefficient. When the compactness remains 85%, the permeability coefficient calculated by the modified KC equation in the range of 10–70% rock content is consistent with the experimental data. The influence of the rock content (10–90%) on the coupling coefficient is well described by the new modified model of the streaming potential coupling coefficient. The new modified model of streaming potential coupling coefficient is helpful to quantitatively evaluate the internal structure evolution of embankment dam by using streaming potential phenomenon.

scholarly journals A Study of Diffusion Permissibility of MK-40 Membrane in Thermodynamic Conditions

2020 ◽  
Vol 26 (4) ◽  
pp. 619-628
Author(s):  
N. Ts. Gatapova ◽  
◽  
M. K. Dzhubari ◽  
N. V. Alekseeva ◽  
◽  
...  
Keyword(s):  
Sodium Chloride ◽  
Ion Exchange ◽  
Permeability Coefficient ◽  
Temperature Drop ◽  
Diffusion Permeability ◽  
Modes Of Operation ◽  
Aqueous Sodium ◽  
Sodium Chloride Solutions ◽  
Thermodynamic Conditions ◽  
Exchange Membrane

The temperature modes of operation of ion-exchange membranes in an electrodialysis apparatus are described. The diffusion permeability of the MK-40 ion-exchange membrane has been experimentally investigated under the conditions of a temperature difference across the membrane at various concentrations of an aqueous solution of sodium chloride. The differences in the diffusion permeability of the membrane in thermostatic and thermodynamic modes are shown. The nature of the influence of the temperature drop across the membrane of aqueous sodium chloride solutions on changes in the value of the diffusion permeability coefficient of the MK-40 membrane was determined.

Ethylsulphate-Based Ionic Liquids in the Liquid–Liquid Extraction of Pyrrole and Pyridine from Isododecane at 298.15 K

2015 ◽  
Vol 10 (3) ◽  
pp. 161-171 ◽  
Author(s):  
Nurshakirin Hazim Chan ◽  
Hanee Farzana Hizaddin ◽  
Ramalingam Anantharaj ◽  
Tamal Banerjee
Keyword(s):  
Experimental Data ◽  
Ionic Liquids ◽  
Distribution Coefficient ◽  
Significant Role ◽  
Entire Range ◽  
Liquid Extraction ◽  
Liquid Liquid Extraction ◽  
Lle Data ◽  
Denitrification Process ◽  
High Distribution Coefficient

Abstract Ternary liquid-liquid equilibria for four systems containing ionic liquids {1-ethyl-3-methylimidazolium ethylsulphate ([EMIM][EtSO4]) and 1-ethyl-3-methylpyridinium ethylsulphate ([EMPY][EtSO4])}(1)+pyrrole/pyridine(2)+isododecane (3) have been determined at 298.15 K. The solute distribution coefficient and selectivity were calculated from experimental LLE data. All systems showed high distribution coefficient and selectivity values at the entire range of pyrrole or pyridine in feed. The consistency of experimental data was ascertained by applying the Othmer-Tobias and hand equations. Furthermore, the experimental LLE data have been compared and correlated using COSMO-RS, NRTL and UNIQUAC models. The influence of aromatic structure without inside ring of cation has a significant role on denitrification process at 298.15 K.

Dimeric/oligomeric DNA methyltransferases: an unfinished story

2009 ◽  
Vol 390 (9) ◽  
Author(s):  
Ernst G. Malygin ◽  
Alexey A. Evdokimov ◽  
Stanley Hattman
Keyword(s):  
Experimental Data ◽  
Dna Methyltransferases ◽  
Structure And Function ◽  
Type I ◽  
Type Ii ◽  
Kinetic Characteristics ◽  
Biological Substrate ◽  
Oligomeric Dna ◽  
And Function

Abstract DNA methyltransferases (MTases) are enzymes that carry out post-replicative sequence-specific modifications. The initial experimental data on the structure and kinetic characteristics of the EcoRI MTase led to the paradigm that type II systems comprise dimeric endonucleases and monomeric MTases. In retrospect, this was logical because, while the biological substrate of the restriction endonuclease is two-fold symmetrical, the in vivo substrate for the MTase is generally hemi-methylated and, hence, inherently asymmetric. Thus, the paradigm was extended to include all DNA MTases except the more complex bifunctional type I and type III enzymes. Nevertheless, a gradual enlightenment grew over the last decade that has changed the accepted view on the structure of DNA MTases. These results necessitate a more complex view of the structure and function of these important enzymes.

scholarly journals Kinetic characteristics of transcriptional bursting in a complex gene model with cyclic promoter structure

2021 ◽  
Author(s):  
Xiyan Yang ◽  
Zihao Wang ◽  
Yahao Wu ◽  
Tianshou Zhou ◽  
Jiajun Zhang
Keyword(s):  
Experimental Data ◽  
Geometric Distribution ◽  
Burst Size ◽  
Mrna Expression Level ◽  
Kinetic Characteristics ◽  
Exponential Distributions ◽  
Gene Model ◽  
Promoter Structure ◽  
Transcriptional Bursting ◽  
Cell To Cell Variability

While transcription occurs often in a bursty manner, various possible regulations can lead to complex promoter patterns such as promoter cycles, giving rise to an important issue: How do promoter kinetics shape transcriptional bursting kinetics? Here we introduce and analyze a general model of the promoter cycle consisting of multi-OFF states and multi-ON states, focusing on the effects of multi-ON mechanisms on transcriptional bursting kinetics. The derived analytical results indicate that bust size follows a mixed geometric distribution rather than a single geometric distribution assumed in previous studies, and ON and OFF times obey their own mixed exponential distributions. In addition, we find that the multi-ON mechanism can lead to bimodal burst-size distribution, antagonistic timing of ON and OFF, and diverse burst frequencies, each further contributing to cell-to-cell variability in the mRNA expression level. These results not only reveal essential features of transcriptional bursting kinetics patterns shaped by multi-state mechanisms but also can be used to the inferences of transcriptional bursting kinetics and promoter structure based on experimental data.

scholarly journals The Study of the Correlation between a Specific Output Flow of Acetate Cellulose Films and the Pressure Gradient, Temperature and Classification of the Processes of Membrane Separation of Solutions

2021 ◽  
Vol 27 (1) ◽  
pp. 095-104
Author(s):  
S. I. Lazarev ◽  
◽  
A. A. Arzamastsev ◽  
V. Yu. Ryzhkin ◽  
O. A. Kovaleva ◽  
...  
Keyword(s):  
Experimental Data ◽  
Temperature Effects ◽  
Membrane Separation ◽  
Transmembrane Pressure ◽  
Kinetic Characteristics ◽  
Separation Processes ◽  
Cellulose Films ◽  
Output Flow ◽  
Pressure And Temperature Effects

A comparative study of the application of membrane, electromembrane and electrobaromembrane technologies for various industries in the field of wastewater treatment and technological solutions is presented. The principle of classification of membrane separation processes is formulated. The characteristic periods of the solvent transfer stimulation were determined. Based on the experimental data obtained on the permeability of the solvent through the MGA-80P and MGA-95 membranes, empirical dependences are proposed that describe the kinetic characteristics of the dependence from transmembrane pressure and temperature effects.

Symmetry and Non-Linearity of osmotic Flow Across Rectal Cuticle of the Desert Locust

1971 ◽  
Vol 54 (2) ◽  
pp. 317-328
Author(s):  
J. E. PHILLIPS ◽  
C. BEAUMONT
Keyword(s):  
Permeability Coefficient ◽  
Rectal Wall ◽  
Tritiated Water ◽  
Diffusion Permeability ◽  
Desert Locust ◽  
Osmotic Flow ◽  
Osmotic Permeability ◽  
Single File ◽  
Flux Measurements

1. A method for measuring osmotic flow of water across rectal cuticle of the desert locust in vitro is described. 2. The osmotic permeability coefficient decreases as the average osmolality of the two bathing solutions increases, probably due to dehydration of the cuticle. This is supported by a corresponding decrease in the diffusion permeability coefficient, as measured by flux of tritiated water in the absence of osmotic flow. 3. Osmotic permeability is at least fifty times greater than diffusion permeability. This supports the hypothesis that osmotic flow occurs by bulk flow or single-file diffusion through pores. Isotopic flux measurements during net flow support this view. 4. The osmotic permeability of the cuticle differs by less than 25 % if at all, in the two directions of flow; that is, rectification or ‘valve-like’ behaviour is not significant. 5. The cuticle represents only 2.6 to 13 % of the total resistance to osmotic flow across the whole rectal wall and is not responsible for the asymmetry of the latter. 6. Application of Beament's model for water transport to the rectal wall of insects can be excluded in the case of the desert locust.

Sign in / Sign up

Export Citation Format

Share Document