VISCOMETRY OF NANODISPERSE MAGNETIC LIQUIDS AND LUBRICATING OILS. 2. METROLOGICAL ANALYSIS OF A DEVICE FOR RHEOLOGICAL STUDIES OF MAGNETIC NANODISPERSE LIQUID MEDIA

Проведен анализ основных источников методических погрешностей магнитного ротационного вискозиметра, позволивший усовершенствовать конструкцию и исключить критические режимы исследований. Теоретическая оценка систематической погрешности прибора показала, что значение относительной ошибки измерений можно довести до значения менее 1%. Наибольший вклад в систематическую погрешность прибора вносит нестабильность температурного режима исследуемой наножидкости и неточность определения высоты слоя жидкости, контактирующего с измерительным цилиндром. Измерение вязкости эталонных жидкостей на магнитном вискозиметре показало, что экспериментальные значения незначительно, примерно на 0,9% завышены. Тарировка прибора на различных эталонных жидкостях позволила снизить суммарную ошибку измерений до десятых долей процента. Магнитный ротационный вискозиметр может найти применение при нестандартных научных исследованиях структуры и реологических характеристик наножидкостей, для оперативного контроля процессов синтеза магнитных жидкостей и аттестации магнитных наножидкостей, предназначенных для технического применения. An analysis is carried out of the main sources of methodological errors of the magnetic rotary viscometer. The analysis allowed to improve design and to eliminate critical modes of the research. Theoretical evaluations of the systematic error of the device showed that the value of the relative measurement error can be brought to a value of less than 1%. The greatest contribution to the systematic error of the device is made by the instability of the temperature regime of the nanofluid under study and by the inaccuracy of determining the height of the liquid layer in contact with the measuring cylinder. The measurement of the viscosity of the reference liquids on the magnetic viscometer showed that experimental values are slightly, by about 0.9% overestimated. Calibration of the device on various reference liquids allowed reducing the total measurement error down to tenths of a percent. The magnetic rotary viscometer can be used in non-standard scientific studies of the structure and rheological characteristics of nanofluids, for operational control of the processes of synthesis of magnetic liquids and certification of magnetic nanofluids intended for technical use.

INFLUENCE OF OLIVE OIL ON THE RHEOLOGICAL CHARACTERISTICS OF MAYONNAISE

Rheological properties are an important parameter for the quality of mayonnaise. This article in-vestigated the effect of adding olive oil on the rheological properties and color change of mayon-naise. The influence of the storage time of mayonnaise in the refrigerator on the change in rheo-logical properties was also investigated. Mayonnaise was prepared on a laboratory rotary disperser of the Turrex type with a rotor / stator system with a rotor speed range (10000-30000 rpm) at room temperature. Mayonnaise contains 75% oil with varying proportions of sunflower oil and ol-ive oil. Rheological measurements were carried out on a Brookfield rotary viscometer with con-centric cylinders at temperatures of 10 ° C and 25 ° C. Based on the data obtained, the consistency coefficient of the rheological parameters, the flow index and the apparent viscosity were calculat-ed. The color of the test samples of mayonnaise was measured using a three-color colorimeter. All mayonnaise samples exhibit non-Newtonian pseudoplastic flow with a defined thixotropic loop area. Research results have shown that the addition of olive oil affects the rheological properties and color of mayonnaise. The addition of olive oil to the oil phase of mayonnaise reduces shear stress, apparent viscosity, consistency factor and color change at 25 ° C and 10 ° C. When storing mayonnaise in the refrigerator for 15 days, the rheological parameters change. Sunflower oil may-onnaise (75%) has the highest value (L), which means it is measured instrumentally as the bright-est.

Optimization of the Composition of the Ointment with Phytoecdysteroids Serpisten

Introduction. Phytoecdysteroids are a group of natural compounds related in structure and physiological effect to ecdysone - the hormone of insect molting. Phytoecdisteroids have been found to have an antiflammatory effect, which suggests that they have regenerative properties. The development of a soft dosage form containing phytoecdysteroids is of interest.Aim. Improvement of ointment compositions with phytoecdysteroids by optimizing the composition of base adjuvants.Materials and methods. As an active substance was used Serpisten, containing the sum of phytoecdysteroids, the main of which is 20-hydroxyecdysone and obtained from the leaves of Serratulaecoronatae. Raw materials "Serpukhi crowned leaves" were registered by the Federal Service Rospotrebnadzor (Moscow) for the production of dietary supplements (Gr. No. 77.99.23.3.U.1922.3.08), substance Serpisten (Gr. No. 77.99.23.3.U.1923.3.08. TU 9369-002-15092611-2008). In work were used the excipients allowed for medical use: the monoglycerides distilled, T-2 emulsifier, tween 80, sodium - carboxymethylcellulose, polyvinyl alcohol, hydroxide of aluminum, aero forces, vaseline, oil vaseline, sunflower oil. Optimization of ointment auxiliary substances composition was carried out according to the Greco-Latin 4 x 4 square plan with repeated observations. The concentration of hydrogen ions from aqueous ointments was evaluated as process parameters; acid number; release of serpistene from ointment into agar gel, thermal stability of structure. The structural and mechanical properties of the optimal composition ointment composition were determined on a RV type REOTEST 2.1 rotary viscometer (RHEOTEST Medingen GmbH, Germany). Ointment Bepanten (GP Grenzach Produktions GmbH, Germany) was used as a comparison preparation.Results and discussion. During optimization of the composition of the diphilic ointment with serpistene, was found that the ratio of hydrophobic and hydrophilic phases should be 1 : 1, it is advisable to introduce into the ointment base an emulsifier T-2, aerosil and a mixture of vaseline and vaseline oil in the proportion of 1 : 1. As a result of the carried out studies on the optimization of ointment compositions, the following serpisten ointment composition is proposed: serpisten - 0.02; emulsifier T-2 - 3.0; aerosil - 3.0; vaseline - 23.0; vaseline oil - 23.0; ethyl alcohol 40 % - 1 ml; purified water to 100.0. Comparative analysis of effective viscosity showed that the proposed composition is as close as possible to the Bepanten ointment.Conclusion. A set of technological studies was carried out to optimize the composition of the Serpisten, 0.02 °% ointment on a diphilic basis. The developed composition and technology made it possible to obtain a composition with thermal stability, bring the hydrogen index of the ointment closer to the pH of human skin and achieve the parameters included in the rheological optimum for dermatological ointments (0.34-108 Pa • s).

Study of the rheological properties of the highly-filled paste-like fuel composition based on oligomeric rubber and dispersed fillers

We present the results of creation of paste-like fuel compositions with a high degree of filling (up to 90 wt.%) and investigation of their rheological properties. The developed composition contained the following components: a polymer matrix (type SNBR-N butadiene rubber) and a mixture of inorganic fillers (preliminarily surface-modified highly disperse potassium chloride, that was microencapsulated by using oligomeric products of polyehtyleneterepthalate glycerolize, and highly dispersed aluminum powder. A surface-active compound (oligomeric polioxypropylene glycol) and plasticizers of different natures were used as additional components, which were introduced in order to increase the degree of filling of the resulting paste-like compositions while maintaining a low level of their viscosity. The dynamic viscosity of the compositions was evaluated in the range of the shear stresses of 1 to 30 kPa and the temperatures of 293 to 323 K by using a rotary viscometer (cone–plane system). The viscosity of the composition which is a mixture of saturated and unsaturated methyl ester fatty acids at the maximum degree of filling (90 wt.%) was at the level of viscosity of the individual binder.

RHEOLOGICAL PROPERTIES OF BISCUITS DOUGH WITH SPELT FLOUR

Background. The analysis of modern literature sources shows that the impro­vement of existing biscuit technologies is aimed primarily at the use of various non-traditional raw materials to regulate the nutritional value and increase the stability of sponge dough during production and baking.Thus, the production of biscuits from spelt flour is one of the most promising areas of its use, as it meets the technological properties of this type of product. The aim of the work is to study the rheological properties of sponge dough from a mixture of premium wheat flour and spelt flour. Materials and methods.The object of the study is the dough for the main biscuit and with the replacement of 10, 20, 30, 40, 50 % of high-grade wheat flour (HGWF) with spelt flour (SF). The study was performed on a rotary viscometer Reotest-2 on a system of cylin­ders S, S3 at a temperature of 20 °C. Shear stress and viscosity are calculated by formulas for the corresponding values of shear rate. The whipping of the sponge dough was defined as the ratioof thevolume of the egg-sugar mixture after beating to the volume of the mixture after adding the flour mixture and stirring for 15 с(%). The stability of the sponge dough (SSD) with the addition of flour mixtures was determined as the ratio of the height of the foam after aging for 15· 60 сat a temperature of 18–20 °C to the total height of the foam column of the sample, expressed as a percentage. Results. The study found a general trend to reduce the viscosity of sponge dough for test specimens depending on the shear rate relative to control. Thus, for the studied shear deformations from 0.167 c-1 to 24.3 c-1, the viscosity of the sponge dough of the control sample decreases from 55.50to 3.26 Pa ∙ с. Replacing wheat flour with spelt flour in the amount of 10 to 50 % helps to reduce the viscosity of sponge dough from 55.50 to 1.55 Pa ∙ с. When studying the dependence of the effective viscosity of the dough for the main biscuit on the content of SF at a fixed shear rate of 24.3 c-1, two areas were identified –in the range of 0–30 and 30–50 % replacement of wheat flour for SF, for which there is a different intensity of viscosity reduction: by 38.3 and 2.4%, respectively. The increase in the stability of sponge cake dough by 3.6–43.6% in the studied samples with respect to control was due to the addition of spelt flour. Conclusion. The use of spelt flour in the composition of the main sponge cake helps to reduce the viscosity, but increases the whipping and stability of the biscuit dough, which is positive for the subsequent molding and baking.

Influence of pollutants on rheological characteristics of sediment flow

<p>Abstract: In view of the weak research on the rheological characteristics involved in the variation of the fluid movement caused by the storm runoff carrying a large amount of pollutants and sediments, this study uses the NDJ-5S rotary viscometer and the self-made slim tube viscometer of Northwest Agriculture and Forestry University. On the basis of the research, the influence of pollutants on the rheological characteristics of high-concentration sandy water flow is studied. The results show that the NDJ-5S rotary viscometer can be used well under the sand content of less than 300kg/m<sup>3</sup>. The double vertical tube slim tube viscometer made by Northwest A&F University can better simulate the sand content of 0～800kg/m<sup>3</sup>; The structure of flocculation between particles in sandy water flow will affect the viscosity of muddy water, and the concentration of sediment and other pollutants will have a certain impact on flocculation. Under the same conditions, the concentration of pollutants increases (0～440kg/m3), the viscosity coefficient of fluid increases (90%～114%), and the variation of sand content from Newtonian body to Bingham body is about 300～400kg/m<sup>3</sup>, The influence of pollutants on the variation points of rheological properties is not significant.</p><p>Keywords: pollutants; sediment; variation; viscometer; Newtonian fluid; Bingham fluid</p><p>Funding: This study was funded by the National Natural Science Foundation of China (No. 41877078, 41371276), Key research and development project of Shaanxi Province (2020ZDLSF06-03-01), National Key Research and Development Program of China (No. 2017YFC0504703) and Knowledge Innovation Program of the Chinese Academy of Sciences (No. A315021615). </p>

Research of the choice of the basis of a semi-solid medicine with a semi-solid extract of Feverfew (Tanacetum parthenium)

The aim. To conduct the research on the choice of the basis for a mild drug with a semi-solid extract of feverfew for use in dermatology. Materials and methods. In the study of the solubility of a semi-solid extract of feverfew (SSFE) used the method of optical microscopy using a laboratory microscope “Konus Academy”. Determination of pH and homogeneity of the studied samples was performed according to the methods described in SPhU, Vol.1. The bioavailability of the model samples was investigated by diffusion in 3 % agar gel. Colloidal stability and thermal stability were determined according to the methods of GOST 29188.3-91. Measurements of rheological parameters were performed on a rotary viscometer “MYR 3000 V 2R” (Viskotech, Spain). Determination of particle distribution was performed using a laser diffraction analyzer of particle size Mastersizer 3000. Results. The best results in determining the organoleptic properties, stability and degree of release of biologically active substances (BAS) showed samples prepared on emulgel and gel bases. Structural and mechanical parameters of the samples on these bases proved the presence of a non-Newtonian type of flow with plastic and thixotropic properties. When determining the distribution of SSFE particles by optical diffraction, their smaller size was determined in the sample on an emulgel basis in comparison with the gel. Conclusions. Emulgel loaded with specific drugs has been found effective in some topical disorders, and it is emerging as potential drug delivery system in the area of dermatology. Since emu-lgel shows enhanced spreadability, adhesion, viscosity and extrusion. Based on the obtained results, an emulsion gel base was chosen as a carrier for a semi-solid drug with SSFE

Synthesis and research of photocurable protective coatings on the basis of olygoesteracrylates

In this work, photocurable protective coatings based on methacrylic acid esters have been developed and their physical and mechanical properties have been investigated. The photocurable compositions were obtained by mixing at different ratios the following methacrylic acid esters: polyethylene glycol dimethacrylate 400 and triethylene glycol dimethacrylate ether, polyethylene glycol dimethacrylate 400 and oligourethane dimethacrylate, polyethylene glycol dimethacrylate 400 and pentaerythritol tetraacrylate. For the obtained compositions, the viscosity was studied using a Brookfield rotary viscometer. To initiate polymerization, a mixture of initiators was used: benzoyl peroxide and benzoin. Curing of the obtained compositions was carried out under the influence of UV rays for 2-5 minutes. For photo-cured compositions, their physical and mechanical properties have been studied. It was found that the composition based on polyethylene glycol dimethacrylate modified with triethylene glycol dimethacrylate at a ratio of 70:30 has the highest strength.

Thermophysical Properties of Nanofluids Composed of Ethylene Glycol and Long Multi-Walled Carbon Nanotubes

In this work, thermal conductivity, viscosity, isobaric heat capacity, and density of stable carbon-based nanofluids are presented. The nanofluids under study are composed of 1,2-ethanediol (ethylene glycol, EG) and long multi-walled carbon nanotubes (MWCNTs), so-called ‘in-house 16h’ (synthesized in our laboratory via catalytic chemical vapor deposition during 16 h with a diameter of 60–80 nm and length of 770 μm). Poly(N-vinylpyrrolidone) (PVP) was used to increase the stability of nanofluids. The nanofluids were prepared via an ultrasonication-assisted, three-step method while their key thermophysical characteristics were obtained using the hot-wire technique and rotary viscometer. As a result, the addition of MWCNTs significantly improved the thermal conductivity of nanofluids by 31.5% for the highest 1.0 wt% (0.498 vol%) long MWCNT content, leaving the Newtonian character of the nanofluids practically intact.

Thermophysical Properties of IoNanofluids Composed of 1-ethyl-3-methylimidazolium Thiocyanate and Carboxyl-functionalized Long Multi-walled Carbon Nanotubes

The concept of IoNanofluids (INFs) as the stable dispersions of nanoparticles in ionic liquids was proposed in 2009 by Nieto de Castro’s group. INFs characterize exciting properties such as improved thermal conductivity, non-volatility, and non-flammability. This work is a continuation of our studies on the morphology and physicochemistry of carbon-based nanomaterials affecting thermal conductivity, viscosity, and density of INFs. We focus on the characterization of dispersions composed of long carboxylic group-functionalized multi-walled carbon nanotubes and 1-ethyl-3-methylimidazolium thiocyanate. The thermal conductivity of INFs was measured using KD2 Pro Thermal Properties Analyzer (Decagon Devices Inc., Pullman, WA, USA). The viscosity was investigated using rotary viscometer LV DV-II+Pro (Brookfield Engineering, Middleboro, MA, USA). The density of INFs was measured using a vibrating tube densimeter Anton Paar DMA 5000 (Graz, Austria). The maximum thermal conductivity enhancement of 22% was observed for INF composed of 1 wt% long carboxylic group-functionalized multi-walled carbon nanotubes.