Исследования диэлектрических свойств нефтяных дисперсных систем в зависимости от соотношения асфальтосмолистых веществ

The degree of influence of the electromagnetic field on oil dispersed systems depends on the dielectric properties of these systems, in particular oil. Dielectric properties of oil depend on the content of high molecular weight polar components: asphaltenes and resins. In this regard, a study was carried out of the dielectric properties of oil in the radio-frequency range, depending on the content of asphalt-resinous substances in it. The obtained results of experimental studies show the correlation of dielectric parameters with the ratio of the content of resins and asphaltenes in oil.

PREPARATION OF STABLE COMPOSITES WITH NANOPARTICLES OF METALS IN BIOMEDICAL MATRICES

The unique properties of metal nanoparticles are increasingly used in the pharmaceutical, medical, food, textile and paint industries. It is known that the properties of nanoparticles depend on the shape, size, concentration. Agglomeration processes that occur during the production and storage of nanoparticles lead to a reduction in the size of the specific area to the volume of nanoparticles, which in turn leads to the loss of the unique properties of nanoparticles. In the process of analysis of domestic and foreign literature it was found that the problem of agglomeration processes of nanoparticles is relevant. One of the possible approaches to solving the agglomeration of synthesized nanoparticles, which is proposed in this work is the use of matrices of carriers. In this case, the matrix can be liquids: monomers, oils of vegetable origin or medical substances that are constituent tablets, capsules, ointments, soaps, and paints.The morphology, size, structure and time stability of silver and copper nanoparticles in the obtained dispersed systems were studied. Examples of stability of composites based on glycerol, polytetrahydrofuran (PTGF), oils of synthetic and vegetable origin with nanoparticles of metals with a size of 15… 52 nm are presented. The stability of dispersed systems has been improved through the use of two approaches: the use of surfactants and dispersed systems based on matrices with low crystallization temperature

Modeling of colloidal systems in technological processes

The article describes the main methods of mathematical modeling of industrial free-dispersed systems. The method of constructing the regression equation by the method of linear and nonlinear installation of coefficients is proposed. The fundamentals of tensor and harmonic approaches to the analysis of disperse systems are considered, which allow optimizing the equations of material and energy balance in the conditions of industrial operation of dispersions.

Cement-free refractory concretes. Part 10. Rheological aspect of technology

The features of the rheological behavior of CFRC matrix systems are considered as highly concentrated dispersed systems. They are characterized by a dilatative, thixotropic and thixotropic-dilatant nature of the flow, depending on the composition, concentration, dispersion, and a number of other factors. The equation of the concentration dependence of the viscosity of suspensions (Pivinskii equation) is proposed. It is shown that the determining factor is the content of a kinetically free dispersion medium in them. The effect of the content of grain aggregate on the rheological properties of foundry systems is characterized. The significant effect of polydispersity of the particles of the solid phase and the temperature on the rheological properties of the HCBS with the dilatant nature of the flow is shown. The data on the effect of defloculation and stabilization of matrix systems on their rheological properties, which determine the reeterological properties of molding systems to obtain CFRC. Ill. 13. Ref. 50.

The general directions of development of longitudinally oscillating ultrasonic emitters for gaseous media

The article is devoted to the development of a longitudinally oscillating emitter designed to influence gas-dispersed systems. The main methods and directions of modernization of radiators are proposed in order to increase the area of the radiating surfaces of the radiators, increase the uniformity of vibrations and reduce mechanical stresses.

Transformation of oil dispersed systems during operation

Using the example of oil road bitumen grades BND 100/130, BND 130/200 and BND 70/100, this article studies the transformation of oil dispersed systems under various logistic schemes of operation. This research focuses on the influence of the conditions for storing road bitumens of different grades on their physical and mechanical properties and group hydrocarbon composition during transportation from the manufacturer to the consumer. The results show that a change in the physical and mechanical properties of road bitumens during high-temperature storage is related to the changes in the group hydrocarbon composition due to the hydrocarbons autooxidation and destabilization of the colloidal structure of dispersal systems. The conditions for storing bitumen with a minimum change in its quality indicators have been determined. It has been established that storage of bitumen under atmospheric conditions allows preserving its original properties without significant changes. There is evidence that nitrogen purging significantly reduces the effect of homolytic processes leading to the transformation of oil dispersed systems during further transportation from the manufacturer to the consumer. Experimental data confirm that of all basic physical and mechanical properties of bitumen, “the depth of penetration of needle” is the most sensitive index, while the “softening temperature” index, frequently used for quality control of bitumen, is inertial. Determining the change in penetration, depending on the duration of storing bitumen, has required formulating a special equation. It has been established that when storing road bitumen at a temperature of 180 ºС, for each hour the index of the penetration depth of the needle at 25 º decreases by 0.8 units. Organizational and technical measures have been determined to ensure the stability of the road bitumen quality during manufacture, storage and transportation to consumers.

INVESTIGATION OF MATHEMATICAL MODEL OF A VIBRATING MIXER WITH A FREEZERY PENDULUM MECHANISM

An extensive review of vibrating mixers, identified their advantages and disadvantages. The application of the action of low-frequency oscillations on the process of mixing bulk inhomogeneous products is substantiated. All considered schemes of vibrating mixers, as well as designs in which mixing devices are driven by vibration-pulse transducers (in which the energy of the main or master system is used to create the technological motion of the driven system) can be attributed to energy-saving technological equipment. The article describes the design, the principle of operation of the developed vibrating mixer with a double pendulum freewheel mechanism for driving the agitator blades in rotational motion. The calculation scheme and laws of motion of this system in the form of Lagrange equations of the second kind (mathematical model) are presented. Using the obtained 2nd order multiple regression equations, recommendations were determined regarding the main parameters of the operating mode of the studied vibration mixing process. Analyzing the results of vibration mixing of bulk inhomogeneous raw materials, we can say that the most influential factors in determining the natural oscillation frequency of the system pendulum, which is one of the main objectives of our study is spring stiffness, spring attachment distance from axis of rotation, rotation angles, pendulum weight, length and the moment of inertia. The paper proves that among various forms of mechanical action on dispersed systems in technological processes vibration action occupies an important place as one of the most effective means to create the necessary dynamic state of dispersed systems.

HYDRAULIC MACHINES FOR SEPARATION OF WET DISPERSED SYSTEMS

Separation processes of wet dispersed systems are quite common in the food, processing and other industries. In particular, these include processes related to the production of fruit and vegetable juices, jams, sunflower and olive oil, the extraction of fat from meat rinds in meat production, the separation of whey from cheese mass in the production of cheese, the separation of grated cocoa into butter and pulp, dehydration of wet dispersed waste of food production (alcohol grain, beer pellets, beet pulp, coffee and barley sludge). These processes are quite energy-intensive and have low-productivity, therefore, much attention is paid for modernization of equipment for their implementation in the direction of improving the indicated efficiency characteristics, as well as increasing reliability and reducing material consumption, complexity and price of working machines. At the same time, the known hydraulic static presses do not provide of low final moisture content of the product and the required productivity of the working process. Vibratory pressing equipment is often quite complex, unreliable and generates intense noise and vibration during of operation. Screw presses with an electromechanical drive, despite of their advantages, do not allow to achieve of the necessary degree of separation of the components of the dispersed system, in addition, their actuators are structurally quite complex and wear out quickly. The authors propose improved schemes of hydraulic presses for separation of wet dispersed systems, which can provide high rates of efficiency of the working process and have a simple and reliable design. The article also presents equations for calculating of the main operating parameters of the proposed equipment.

Application of Vinyl ether Copolymers for Surface Modification of Carbon Black

In this work, the possibility of stabilizing aqueous dispersed systems of carbon with vinyl ether copolymers of various composition and structure was investigated. It was shown that the presence of hydrophobic fragments in the macromolecule chain plays a significant role and positively affects the results of stabilization of aqueous dispersions of carbon particles. It was shown that the composition and molecular architecture of the stabilizing copolymer strongly affects the stabilizing ability in studied systems. Studies have shown that the use of a polymeric stabilizer in combination with ultrasonic treatment of dispersed systems makes it possible to obtain stable, homogeneous, highly dispersed suspensions. At the same time, it was demonstrated that a strong increase in the time and intensity of ultrasonic treatment of the system does not lead to a significant improvement in the results