The main scientific and practical results of the improvement of  vibrating feeders-screens for mining and metallurgical industry are  presented on the basis of dynamic calculation of the vibrating feederscreen with two differently directed self-balancing vibrators. Methods  of theoretical generalizations are described using mathematical statistics, physical and mathematical modeling, computation and feasibility studies, laboratory and full-scale experimental studies, industrial  tests in the conditions of operating enterprises using standard and new  methods. Mathematical modeling and calculation of the parameters of  a vibrating feeder of the PVG type are proposed. It is recommended  when choosing dynamic parameters of the feeder, to use the vibration  transmission coefficient, which is taken within the limits (1.5  –  3.5)g,   and in heavy loading modes, is up to 5g. It is shown that during preparation of breeze coke in the crushing body, from 10 to 50  % of fine  material is received from its bunker with a particle size of 0  –  3  mm,  which is additionally re-milled, reducing the quality of coke. A vibrating feeder-screen with a spatial oscillation of the working element will  increase the efficiency of screening of the material by 15  –  20  % and  will improve the self-cleaning of the screen. The driving forces of the  exciters are directed at different angles of 15 and 45° to the screening surfaceand are attached from each other at a distance equal to half  width of the box, i.e. 600  mm. It is established that in the resonance  mode at a constant amplitude with increasing frequency the coefficient  of the vibro-displacement regime increases according to a quadratic  dependence, at a working frequency of 100 rad/s it also increases from  the loading edge of the feeder to the unloading and from one side to  another, the value of which varies within 2.62  –  2.84.

Objective: We determined a safety level of the agents by the residual amount of the anionic surfactants in wastewater from the objects after their washing with the agents for the treatment of children's products. Materials and methods: 16 detergents for children's clothes washing were purchased at the supermarkets of Kyiv. In our study we applied sanitary-and-chemical research methods: express method for the assessment of the anionic surfactants on the clothes fabrics; an extraction-photometric method for the determination of the the residual amount of the main active substances of the anionic surfactants in the experimental sample. Results: The analysis of the results shows that there is a significant difference in the surfactant amount in the wastewater after washing with powder and liquid detergents based on the synthetic anionic surfactants and natural soap. Therefore, the anionic surfactants are rinsing best of all from the clothes washed with the detergents based on natural soaps (Soaps “Droog”, “Clean & White”, “Kroha”). After washing of the children's clothes with powder and liquid detergents for automatic washing based on synthetic anionic surfactants, the residual amount of the anionic surfactants on the fabrics exceeds the accepted hygienic standard. Conclusions: It has been discovered that even after repeated rinsing, the fabrics, treated with washing powder and liquid detergents, contain the residual amount of the anionic surfactants that exceeds normative parameters (8 of 13 investigated detergents based on the anionic surfactants) by 2-3 times. Taking into account a specificity of children’s functional skin state, especially the incompletely formed multistage protection system, it is recommended to use the detergents based on natural soap and products containing less than 5% of the surfactants for washing of the clothes of the children aged 0 to 6 years.

Background. The study is devoted to the assessment of the cytotoxic properties of various surfactants by a method that is highly sensitive to identification of their negative effect on living mammalian cells. Objective. The aim of the work is to carry out a comparative assessment of modern surfactants in terms of the degree of manifestation of cytotoxic properties. Methods. The study of 10 surfactants was carried out with a new method for assessing the cytotoxic effect of agents based on surfactants, which is a modification of The RBC Hemolysis Test and Hemoglobin Denaturation Test. This method calculates the integral cytotoxicity index, which takes into account the data obtained by two tests. The following indicators were determined in the work: the percentage of hemoglobin denaturation in a 1% surfactant solution (D, %), the concentration of the surfactant solution at which hemolysis of 50% erythrocytes occurs (H 50 ,%), and the cytotoxicity coefficient (C c , conv. un.) of surfactants which is calculated by the formula C c = H 50 /D10000. Results. According to the integral C c indicator, the studied surfactants can be ranked according to the degree of toxicity reduction in the following order: sodium lauryl sulfate (0.09)-sodium laurate sulfate (0.13)cocamidopropyl betaine (0.27)-sodium salt of polyethoxysulfosuccinate (0.27)-alkyldimethyl betaine (1.07)disodium cocoamphodiacetate (1.99)-sodium salt n-palmethylglutamic acid (3.22)-cocoglucoside (27.86). Diethanolamides of coconut oil fatty acids and polyquaternium 7 in the studied concentration range (up to 1%) did not show denaturation properties. Conclusions. Studies have shown that surfactants significantly differ from each other by the level of the damaging effect, the most aggressive components were anionic and amphoteric surfactants, nonionic surfactants have a significantly lower cytotoxic effect (10 times). The results obtained should be taken into account when creating soft agents based on surfactants.