Showing papers on "Viscometer published in 2022"

A Comprehensive Review on MEMS-based Viscometers

Abstract: Viscosity is an important rheological parameter, which needs to be measured accurately in various industrial applications to improve the quality of the product. Micro-electro-mechanical system (MEMS)-based microfluidic viscometers are nowadays overpowering conventional types of viscometers due to many advantages such as compatibility for both Newtonian and non-Newtonian fluids, small size, higher shear rates, no solvent evaporation, small sample size requirement (in micro and nano-litres), and better accuracy. This paper summarizes a comprehensive review on the state-of-the-art of MEMS-based technologies combined with microfluidics for realizing the viscometers to determine various fluidic parameters, important for applications in different fields like biopharmaceuticals and protein therapeutics, lubricants/adhesives, healthcare, food industries, cosmetics, concrete, paints, fuel and petroleum industries, etc. This review covers the basic sensing principles of various types of MEMS-based technologies useful for viscometer applications, such as pressure, diaphragm, viscometer/rheometer on a chip (VROC), acoustic, cantilever etc. Limitations of different types of commonly available tabletop viscometers are outlined. Considering the present and future applications of MEMS-based viscometers, their role in industrial applications are also discussed in detail.

Assessment of Thermophysical Performance of Ester-Based Nanofluids for Enhanced Insulation Cooling in Transformers

Abstract: Nanotechnology provides an effective way to upgrade the thermophysical characteristics of dielectric oils and creates optimal transformer design. The properties of insulation materials have a significant effect on the optimal transformer design. Ester-based nanofluids (NF) are introduced as an energy-efficient alternative to conventional mineral oils, prepared by dispersing nanoparticles in the base oil. This study presents the effect of nanoparticles on the thermophysical properties of pure natural ester (NE) and synthetic ester (SE) oils with temperature varied from ambient temperature up to 80 °C. A range of concentrations of graphene oxide (GO) and TiO2 nanoparticles were used in the study to upgrade the thermophysical properties of ester-based oils. The experiments for thermal conductivity and viscosity were performed using a TC-4 apparatus that follows Debby’s concept and a redwood viscometer apparatus that follows the ASTM-D445 experimental standard, respectively. The experimental results show that nanoparticles have a positive effect on the thermal conductivity and viscosity of oils which reduces with an increase in temperature.

Azobenzene photoisomerization probes cell membrane viscosity

Abstract: The viscosity of cell membranes is a crucial parameter that affects the diffusion of small molecules both across and within the lipid membrane and that is related to several diseases. Therefore, the possibility to measure quantitatively membrane viscosity on the nanoscale is of great interest. Here, we report a complete investigation of the photophysics of an amphiphilic membrane-targeted azobenzene (ZIAPIN2) and we propose its use as a viscosity probe for cell membranes. We exploit ZIAPIN2 trans-cis photoisomerization to develop a molecular viscometer and to assess the viscosity of Escherichia coli bacteria membranes employing time-resolved fluorescence spectroscopy. Fluorescence lifetime measurements of ZIAPIN2 in E. coli bacteria suspensions correctly indicate that the membrane viscosity decreases as the temperature of the sample increases. Given the non-homogeneity and the anisotropy of cell membranes, as supported by the photophysical characterization of the probe within the lipid bilayer, we shed new light on the intricate membrane rheology.

The Synergetic Impact of Anionic, Cationic, and Neutral Polymers on VES Rheology at High-Temperature Environment

Abstract: Hydraulic fracturing operations target enhancing the productivity of tight formations through viscous fluid injection to break down the formation and transport proppant. Crosslinked polymers are usually used for desired viscoelasticity of the fracturing fluid; however, viscoelastic surfactants (VES) became a possible replacement due to their less damaging impact. To design a fracturing fluid with exceptional rheological and thermal stability, we investigated mixing zwitterionic VES with carboxymethyl cellulose (CMC), hydroxyethylcellulose (HEC), or a poly diallyl dimethylammonium chloride (DADMAC) polymers. As a base fluid, calcium chloride (CaCl2) solution was prepared with either distilled water or seawater before adding a polymer and the VES. A Chandler high-pressure, high-temperature (HPHT) viscometer was used to conduct the viscosity measurements at a shear rate of 100 1/s. It has been found that adding 1% CMC polymer to 9% (v/v) VES increases the viscosity more compared to 10% (v/v) VES at reservoir temperatures of 143.3 °C. On the other hand, adding only 1.0% of HEC to 9% (v/v) VES doubled the viscosity and proved more effective than adding CMC. HEC, nevertheless, reduced the system stability at high temperatures (i.e., 148.9 °C). Adding DADMAC polymer (DP) to VES increased the system viscosity and maintained high stability at high temperatures despite being exposed to saltwater. CaCl2 concentration was also shown to affect rheology at different temperatures. The improved viscosity through the newly designed polymer can reduce chemical costs (i.e., reducing VES load), making it more efficient in hydraulic fracturing operations.

Viscosity and Surface Tension of High-Viscosity Standard Tris(2-ethylhexyl) Trimellitate Close to 0.1 MPa between 273 and 523 K by Surface Light Scattering

Abstract: In the present work, the liquid viscosity and surface tension of tris(2-ethylhexyl) trimellitate (TOTM) was determined close to 0.1 MPa over a temperature range between 273 and 523 K by surface light scattering (SLS). Such investigations were stimulated by the fact that TOTM is suggested as a potential viscosity standard of moderately high viscosity for temperatures up to 473 K and pressures up to 200 MPa. Based on the SLS experiments at macroscopic thermodynamic equilibrium, a simultaneous determination of liquid viscosity from 273 to 523 K and surface tension from 398 to 523 K with relative expanded uncertainties typically below 0.03 (coverage factor k = 2) was possible. To evaluate the results from SLS and to check possible surface orientation effects found in our previous SLS studies on liquid organic hydrogen carriers, conventional methods in the form of the pendant-drop method and capillary viscometry were used to determine the surface tension and viscosity from 273 to 573 K and from 293 to 353 K, respectively. For evaluating all experimental methods applied, the liquid density was obtained with the help of a vibrating-tube densimeter between 283 and 473 K. From a long-time SLS study at 573 K and subsequent density and nuclear magnetic resonance measurements, a clear sample degradation of TOTM was observed, which may hinder its application as an industrial viscosity standard above 523 K. For both the surface tension and the viscosity which covers a range between about 1500 and 0.9 mPa s at temperatures between 273 and 523 K, agreement between the results from SLS and the conventional methods within combined uncertainties was found, which is also valid by comparison with the literature. In summary, the experimental results from this work could not only contribute to an improved data situation for viscosity and surface tension of TOTM over a broad temperature range but also reveal that TOTM does not show pronounced molecular orientation effects at the vapor–liquid interface which would influence the dynamics of the surface fluctuations probed by SLS.

A Fluorogenic Far Red-Emitting Molecular Viscometer for Ascertaining Lysosomal Stress in Live Cells and Caenorhabditis elegans

Abstract: The cellular physiochemical properties such as polarity, viscosity, and pH play a critical role in cellular homeostasis. The dynamic change of lysosomal viscosity in live cells associated with different environmental stress remains enigmatic and needs to be explored. We have developed a new class of Julolidine-based molecular viscometers with an extended π-conjugation to probe the lysosomal viscosity in live cells. High biocompatibility, pH tolerance, and the fluorogenic response with far red-emission (>600 nm) properties make these molecular viscometers suitable for live-cell fluorescence imaging in Caenorhabditis elegans. Among these probes, JIND-Mor is specifically designed to target lysosomes via simple modification. The real-time monitoring of lysosomal viscosity change under cellular stress was achieved. We believe that such a class of molecule viscometers has the potential to monitor lysosomal health in pathogenic conditions.

Water/Cement/Bentonite Ratio Selection Method for Artificial Groundwater Barriers Made of Cutoff Walls

Abstract: As urban development requires groundwater table isolation of various historically polluted sources, the necessity of building effective, strong, flexible, and low-permeability cutoff walls raises the question of choosing optimum construction materials. Various authors have proposed water–cement–bentonite mixtures, which are often chosen by experience or a trial-and-error approach, using classical methods for testing (Marsh funnel) and representation of results (water–cement ratio, water–bentonite ratio). The paper proposes a more precise approach for assessing the viscosity and global representation of the three components. Moreover, this approached is exemplified with a better documented recipe for the choice of materials based on laboratory results. The representation of the mixtures was undertaken on a limited domain of a ternary diagram, where the components are given in terms of mass percentage. The derived properties (viscosity, permeability, and compressive strength) are presented on a grid corresponding to the physically possible mixtures. Based on this representation, the most efficient recipes are chosen. Because the mixture contains only fine aggregates, the viscosity was determined using a laboratory viscosimeter.

Parallel-Disk Viscometry of a Viscoplastic Hydrogel: Yield Stress and Other Parameters of Shear Viscosity and Wall Slip

Abstract: The rheology, i.e., the flow and deformation properties, of hydrogels is generally a very important consideration for their functionality. However, the accurate characterization of their rheological material functions is handicapped by their ubiquitous viscoplasticity and associated wall slip behavior. Here a parallel-disk viscometer was used to characterize the shear viscosity and wall slip behavior of a crosslinked poly(acrylic acid) (PAA) carbomer hydrogel (specifically Carbopol® at 0.12% by weight in water). It was demonstrated that parallel-disk viscometry, i.e., the steady torsional flow in between two parallel disks, can be used to unambiguously determine the yield stress and other parameters of viscoplastic constitutive equations and wall slip behavior. It was specifically shown that torque versus rotational speed information, obtained from parallel-disk viscometry, was sufficient to determine the yield stress of a viscoplastic hydrogel. Additional gap-dependent data from parallel-disk viscometry could then be used to characterize the other parameters of the shear viscosity and wall slip behavior of the hydrogel. To investigate the accuracy of the parameters of shear viscosity and apparent wall slip that were determined, the data were used to calculate the torque values and the velocity distributions (using the lubrication assumption and parallel plate analogy) under different flow conditions. The calculated torques and velocity distributions of the hydrogel agreed very well with experimental data collected by Medina-Bañuelos et al., 2021, suggesting that the methodologies demonstrated here provide the means necessary to understand in detail the steady flow and deformation behavior of hydrogels. Such a detailed understanding of the viscoplastic nature and wall slip behavior of hydrogels can then be used to design and develop novel hydrogels with a wider range of applications in the medical and other industrial areas, and for finding optimum conditions for their processing and manufacturing.

The design of viscometer with smartphone controlling

Abstract: New design of a viscometer based on the s tokes viscosity measurement method is proposed. The principle of operation of this viscosimetr is based on the use of ball periodic alternated movement in a horizontally positioned cuvette that filled with the test liquid. The movement appears under the in fluence of a magnetic field that created by two electromagnets. Registration of the ball movement inside the cuvette is carried out using an optoelectronic pair. A distinctive feature of the proposed design is control by using a program that installed on t he user's smartphone, which also carries out the primary data processing. Data transmission is carried out over the radio channel using a Bluetooth module. Disposable cuvettes are used for measurements. This approach makes it possible to significantly redu ce both the device production costs and operating costs by eliminating most of the operations for the device preparing for working (the vast majority of existing types of viscometers require thorough flushing of all units in contact with the test medium). In addition, the proposed approach excludes the occurrence of measurement errors associated with insufficiently thorough preparation of the device for operation.

Ultrasonic depolymerization of aqueous tara gum solutions: kinetic, thermodynamic and physicochemical properties.

Abstract: BACKGROUND Tara gum is characterized by its high viscosity and medium solubility, which is due to its high molecular mass. However, for many applications, these characteristics are undesirable and make their use infeasible. The present study aimed to evaluate the effect of high-intensity ultrasound on the depolymerization of aqueous solutions of tara gum. The effect of ultrasonication was investigated by viscometry analysis as well as FTIR and solubility. RESULTS The intrinsic viscosity (η) and the molecular weight (Mw ) of tara gum decreased after ultrasound, achieving a molecular weight reduction of 13.50 x 105 g/mol after 60 min of sonication at 25 °C compared to 22.04 x 105 g/mol before treatment. Degradation kinetics were applied to estimate the rate constant of degradation (k). It was found that the k value of tara gum increased with increasing temperature from 25 °C to 55 °C. Partially hydrolyzed tara gum showed greater solubility at the two studied temperatures (25 and 80 °C). Ultrasonic treatment did not change the chemical structure of the tara gum molecules according to the structural analysis by FTIR, confirming its action only as breaking the structure of the polymer. CONCLUSION Ultrasound is a simple method for effectively reducing the molecular weight and viscosity and increasing the solubility of tara gum, without using chemical reagents. The synthesis of partially hydrolyzed tara gum expands its potential for use in food products, including as a soluble dietary fiber. This article is protected by copyright. All rights reserved.

Combined Surface Light Scattering and Pendant-Drop Experiments for the Determination of Viscosity and Surface Tension of High-Viscosity Fluids Demonstrated for Ionic Liquids

Abstract: Abstract The present study provides a strategy for the determination of the viscosity and surface tension of high-viscosity fluids in the form of ionic liquids (ILs) at equilibrium conditions by combining surface light scattering (SLS) and the pendant-drop (PD) method within one experimental setup. Through the study of the same sample under identical conditions by both methods inside a closed system, the surface tension determined via the PD method can be directly used to evaluate the dynamics of surface fluctuations of ILs with an overdamped behavior probed by SLS for accessing their viscosity. In connection with the SLS experiments, variations in the applied detection geometries in reflection and transmission direction and in the probed wave vectors down to relatively small values were also addressed. The reliability and self-consistency of SLS and the PD method applied within the same sample cell has been proven by investigating the reference fluids tris(2-ethylhexyl) trimellitate (TOTM) and n -dodecane featuring relatively high and low viscosities. For the two studied model ILs of opaque to non-transparent color, i.e. , the hydrophobic 1-methyl-3-octylimidazolium hexafluorophosphate ([OMIM][PF 6 ]) and the hydrophilic 1,3-bis(2-(2-methoxyethoxy)ethyl)imidazolium iodide ([(mPEG 2 ) 2 Im]I), the combination of PD measurements and SLS experiments in reflection direction performed at ambient pressure between (303 and 373) K allowed access to the viscosity and surface tension with typical relative expanded uncertainties of (4 and 2) %. These results agree well with own viscosity data from capillary viscometry and experimental data in the literature, demonstrating the performance of the novel approach for the contactless in-situ measurement of viscosity and surface tension of fluids with relatively high-viscosity such as ILs.

Improved Enhanced Oil Recovery Polymer Selection Using Field-Flow Fractionation

Abstract: Various polyacrylamide polymers have been successfully applied in chemical enhanced oil recovery (EOR) projects. These polymers are characterized by high molecular weights (MWs) to achieve high viscosifying power. The selection of polymers for chemical EOR is a crucial step in the field testing and implementation of such EOR projects. The reason is that per-pattern operating expenditures (OPEX) are one of the sensitive cost drivers for such projects. The important parameters for the selection of polymers are the filtration ratio, viscosifying power, polymer retention, and stability of the polymers at reservoir conditions. The MW distribution (MWD) of the polymers has a major impact on polymer properties and performance. Measuring the MWD is challenging using conventional methods. Field-flow fractionation (FFF) enables the determination of the distribution to select and quality check various polymers. Multiangle light scattering (MALS) was used as the main detector. Polymers with high MWs (>1 MDa) are used for EOR to obtain highly viscous aqueous solutions. The MWD of the polymers is crucial for the solution characteristics. Conventional analysis of polymers is performed using either viscometry, which is able to determine the average MW but does not give information on MWD, or size-exclusion chromatography (SEC), which is restricted to MWs of <20 MDa. FFF is based on the analytes flowing at different speeds in a channel-dependent on their size and mass. This effect leads to separation, which is then used to determine the MWD. FFF allows determining the MW and MWD of various ultrahigh MW polyacrylamides (HPAAMs). The FFF measurements showed that, despite similar MWs being claimed, substantial differences in MWD are observed. This technology allowed the quantification of the MWD of HPAAMs up to an MW of 5 GDa. Furthermore, gyration radii of the HPAAM molecules were determined. Selecting polymers on viscosifying power only is not addressing issues related to different MWs and MWDs such as selective polymer retention and degradation of the high molar mass part of the distribution. The results were used to improve the polymer selection for chemical EOR projects. In addition to viscosifying power and price, also the MWD and changes of the MWD in the porous medium are considered in the selection of the polymer. Overall, this work presents a new technique for the analysis of ultrahigh MW EOR polymers, which enables the possibility to determine the full range of polymer MWDs. This available information enhances the EOR polymer selection process addressing selective polymer retention and mechanical degradation in addition to the viscosifying power of polymers.

Effect of Calcium Sulphate Pre-crosslinking on Rheological Parameters of Alginate Based Bio-Inks and on Human Corneal Stromal Fibroblast Survival in 3D Bio-Printed Constructs

Abstract: The principle of three-dimensional (3D) bio-printing involves integration of biomaterials, live cells and controlled motor systems for creating complex biomimetic constructs. Bio-ink is one of the most important components in the process of 3D bio-printing and needs to be sufficiently viscous to be dispensed as a free-standing filament but be biocompatible to maintain cell viability and function. Alginate has been used widely for 3D bio-printing due to its biocompatibility, tunable properties, rapid gelation, low cost, and ability to be functionalized to direct cell behavior. By tuning the physiochemical parameters of alginate-based bio-inks, such as viscosity, improvements in print resolution, fidelity and growth characteristics of encapsulated cells can be achieved. This study aimed to improve the printability of low concentration alginate bio-inks by utilizing calcium sulphate (CaSO4) pre-crosslinking. A variety of alginates, differing in their viscosity, molecular weight and b-D-mannuronate and α-L-guluronate residues were investigated by wet spinning and bio-printing. Rheological and structural properties of pre-crosslinked alginates were characterized with the aim of mitigating the resolution problems associated with the use of low percentage alginate bio-inks, more favorable for maintaining cell viability. Pre-crosslinking produced a significant effect on viscosity of biomaterials improving their suitability for the bio-printing process and influencing the final resolution of the printed structure. Medium viscosity high b-D-mannuronate containing alginate (MVM) showed the highest degree of viscosity change compared to the control (p < 0.0001; n = 6), assessed by single value viscometry analysis and shear rheology, after pre-crosslinking and was subsequently used in experiments with cells. The survival of human corneal stromal fibroblasts (CSFs) was assessed using CellTiterGlo metabolic assay and confirmed with Calcein acetoxymethyl and Ethidium homodimer -1 live/dead staining in pre-crosslinked alginate fibers and bio-printed lattices. Encapsulation of CSFs in pre-crosslinked alginate-based bio-inks did not have a detrimental effect on CSF viability compared to the non-pre-crosslinked control over 7 days under standard cell culture conditions (p > 0.05, n = 3). Overall, printability of low percentage alginate bio-inks was improved by pre-crosslinking without affecting the biocompatibility of the bio-inks.

Effect of heterogeneous protein distribution on in situ pasting properties of black rice starch

Abstract: In situ scanning electron microscopy/energy-dispersive spectroscopy (SEM-EDS) was used for depth profiling of black rice and the visualisation and quantification of the heterogeneous protein distribution. The SEM-EDS images of black rice grains revealed high protein content in the aleuronic layer, cell membrane and amyloplasts, especially in the spheroidal particles among the amyloplasts. This phenomenon has not been directly observed by other apparatuses because successive abrasion of brown rice by milling destroys the integrity of the cell walls and amyloplasts. Consistent with the SEM-EDS findings, confocal laser scanning microscopy and the Kjeldahl method preformed after successive milling indicated that the protein content of black rice decreases from the surface to the inner layer. Pasting curves obtained with a viscometer indicate that the protein distribution significantly affects the peak viscosity, setback viscosity, and pasting temperature of rice starch. Protein extraction weakened the structural stability of starch granules, possibly because the protective effect of protein is lost during extraction. This study improves the understanding of the protein distribution in rice grains and its effect on the pasting properties of rice starch; the findings are useful in food processing for managing rice nutrient compositions.

An experimental study of sio2-nd hybrid nanofluid: thermal conductivity, viscosity and stability with new forecast models

Abstract: In the present investigation, thermal conductivity, and viscosity properties of water-based SiO2-ND hybrid nanofluid were measured, experimentally Nanofluids were prepared by using two-step method and with three different (0.5%, 0.75%, and 1%) concentrations. Every concentration had three different SiO2-ND mixtures (50% SiO2 - 50% ND, 33% SiO2 - 66% ND, 66% SiO2 - 33% ND). The most stable sample was measured as -33.4 mV. Measurements of viscosity and thermal conductivity were done from 20 oC to 60 oC at every 10 oC. Thermal conductivity data were measured by thermal conductivity analyzer and viscosity data were measured by tube viscometer. The highest thermal conductivity enhancement was measured for 1% SiO2 0.33 : ND 0.66 at 40 oC and highest relative dynamic viscosity calculated as 4.19 for 1% SiO2 0.33 : ND 0.66 at 40 oC. A comparison table is also given to show the zeta potential values-concentration relations Finally, two different correlations for predicting thermal conductivity and viscosity were proposed for practical usage.

Tailoring stability and thermophysical properties of CuO nanofluid through ultrasonication

Abstract: The objective of this research is to examine how ultrasonication time affects agglomeration, stability, thermal conductivity, and viscosity of CuO nanofluid. Using different reaction conditions, distinct shaped CuO nanoparticles are synthesised and dispersed in an EG: DW (70:30) ratio with 0.3 vol%. Microscopic and TEM images are used to analyze colloidal solutions with varying sizes and shapes of nanoparticles. After 30 days of preparation, the zeta potential is measured to ensure that the suspension is stable. The Bridgman equation is used to compute thermal conductivity using sound velocity values. Viscosity of colloidal suspension is measured by viscometer. All of the studies are performed at 30° ± 2 °C room temperature for ultrasonication times ranging from 30–120 min. At an optimal sonication time of 80 min, there is less agglomeration and more stable particle dispersion. In comparison to other morphological suspensions, CuO spherical shape suspended nanofluid has the lowest viscosity and maximum thermal conductivity, as well as the most stable fluid. At the optimal sonication period, measured results demonstrate thermal increase and decreased viscosity, which could have implications for heat transfer applications.

Experimental and Theoretical Investigation of the Thermophysical Properties of Cobalt Oxide (Co3O4) in Distilled Water (DW), Ethylene Glycol (EG), and DW–EG Mixture Nanofluids

Abstract: Solid particles scattered in a base fluid for a standard no larger than 100 nm, constituting a nanofluid, can be used to improve thermophysical characteristics compared to the base fluid. In this study, theoretical and experimental investigations were carried out to estimate the density, viscosity, and effective thermal conductivity of Co3O4 in distilled water (DW), ethylene glycol (EG), and DW–EG mixture nanofluids. Co3O4 nanoparticles with diameters of 50 nm were dispersed in different base fluids (i.e., EG, DW, 60EG:40DW, 40EG:60DW, 20EG:80DW) with varying concentrations of 0.025–0.4 vol.%. Thermal conductivity was estimated by the hot-wire technique, and viscosity was determined using a viscometer apparatus. According to the measurements, the viscosity of Co3O4 nanofluids decreased with increasing temperature, and increased with increasing volume fraction. The results revealed that the thermal conductivity of Co3O4 nanofluids increased with increasing temperature and volume concentrations. Moreover, the measurements found that the maximum thermal conductivity of 10.8% and the maximum viscosity of 10.3% prevailed at 60 °C in the volume fraction of 0.4%. The obtained viscosity and thermal conductivity results of the present experiments on Co3O4 nanofluids were compared with previous results. The results showed good agreement with theoretically proposed models to predict nanofluids’ viscosity and thermal conductivity. Thus, the thermal conductivity results of Co3O4 nanofluids are promising with respect to the use of nanofluids in solar thermal applications.

Comprehensive Studies of the Processes of the Molecular Transfer of the Momentum, Thermal Energy and Mass in the Nutrient Media of Biotechnological Industries

Abstract: This article puts forward arguments in favor of the necessity of conducting complex measurements of molecular transport coefficients that quantitatively determine the coefficients of dynamic viscosity, thermal diffusivity and molecular diffusion. The rheological studies have been carried out on the viscometers of two types: those with a rolling ball (HÖPPLER® KF 3.2.), and those with a rotary one (Rheotest RN 4.1.). The thermophysical studies have been performed using the analyzer Hot Disk TPS 2500S. The measurements have been taken in the temperature range of 283 to 363 K. The concentration of dry substances has varied from 16.2 to 77.7% dry wt. An empirical equation for calculating the density of aqueous solutions of beet molasses has been obtained. The diagrams of the dependence of the dynamic viscosity on the shear rate in the range of 1 s−1 to 500 s−1 at different temperatures have been provided. The diagrams of the dependence of the coefficients of thermal conductivity and thermal diffusivity on the temperature and the concentration of dry substances have been presented, and empirical equations for their calculation have been obtained. The findings can be used for engineering calculations of hydrodynamic and heat-exchange processes in biotechnological equipment.