Cancer incidence and nuclear facilities in Ukraine: a community-based stydy

The study goal was to investigate malignant tumors incidence in 5 Ukrainian cities with nuclear hazardous enterprises: extractive, processing enterprises of uranium ore (Zhovti Wody and Dniprodzerzhynsk of Dnipropetrovsk region) and nuclear power stations (Energodar of Zaporizhska region, Pivdennoukrainsk of Mykolayivska region, Netishyn of Khmelnytska region). Materials and methods: average annual population of the cities under study in 2003–2008 was 439 600 persons. Total and specific cancer incidence was investigated. Site specific incidence was analyzed for malignancies proved to be radiosensitive in previous studies: trachea, bronchus and lung, breast, kidney, thyroid cancer and leukemia. Data on cancer cases were received in National Cancer Registry of Ukraine (National Cancer Institute). There was used the data of the State Statistics Committee of Ukraine on the size of the studied population by gender — age groups. Standardized incidence ratio of cancer at a whole and for each of five specific forms of malignancies were calculated for the population of each city and group of cities depending on the nature of industrial activity. Results: During the observed period there were registered 9 381 cancer cases in inhabitants of Ukrainian cities with radiation hazardous facilities. There was stated that cancer incidence rate in population of 5 cities significantly exceeded national and regional levels. Among specific forms of malignancy there were observed excess of lung, trachea, bronchus, breast, kidney cancer and leukemia in population of extractive, processing uranium ore cities. No excess of thyroid cancer was identified. In cities with nuclear power station there were registered excess of kidney cancer. Conclusion: Results of the study suggest the necessity to explore the role of various factors in forming the identified cancer incidence features in the Ukrainian population living near the nuclear power facilities

Substantiation of amplitude-frequency characteristics and design parameters of the vibration exciter of the separator of volume vibrations

Evaluation of the influence of amplitude-frequency and power parameters of external technological action on bulk products in the process of separation of the impact, the way of lowfrequency oscillations of the working bodies of the separator and the angle of inclination of the container during processing determines the main indicators of technical and economic efficiency of the explored process, which is the relevance of the research. The purpose of the study is to substantiate the operating parameters of the explored separator of volume vibrations by determining the patterns of change in the kinematic and power characteristics of the vibration drive. To determine the rational parameters of the vibration screening process, the equations of motion of the working bodies in the form of a conical sieve surface were obtained using the method of Lagrange equations of the 2nd kind. Using the solution of the Cauchy problem for linear inhomogeneous differential equations, the solution of the latter was obtained. Using the Math CAD mathematical environment, the dependences of the amplitude of oscillations, vibration velocity and vibration acceleration, and the intensity of oscillatory motion were obtained, which allowed performing a mathematical analysis of the power and energy characteristics of the vibration drive of the explored separator. The main effects of the developed design of the vibrating separator are an increase in the driving force of the process of separation of bulk solids in this work, which was achieved by providing the working cylindrically-conical container with vibratory motion; improvement of the conditions for the passage of product particles through the perforations, which was achieved by providing the sieve surface with volumetric vibrations; reduction of energy consumption and improvement of the operating conditions of the supporting units during the operation of the designed vibrating screen, which was achieved by installing additional elastic elements between the separator body The inclined arrangement of the conical sieve surface allows for spatial gyratory or circular translational motion, which allows implementing of the advantages of bulk separation of bulk solids. The results of the analytical study allowed substantiation of the optimal angle of inclination of the working sieve surface. Based on the analysis, the design parameters of the vibration exciter were substantiated and specified and the design of this technical system was presented. The practical value of the conducted research can be attributed to using the designed kinematic combined vibration exciter of volumetric oscillations in the separator, which allows reducing the weight of the oscillating parts of the drive and, accordingly, the energy consumption for the separation proces

Dynamics of interfacial interaction between components during mixing

The effect of mechanical action on the mixing and whipping of a mixture of components contributes to the establishment of a three-dimensional sponge-mesh continuous structure of the gluten framework, as it determines the elastic and elastic properties of the medium and is relevant in the dispersion of gas in a liquid. The purpose of the work was to establish the relationship between the gas retention capacity of the medium and the energy consumed for the hydration of the components. The experiments performed the task of determining the gas retention capacity of the medium with variable parameters of the height of the liquid phase from the intensity of mixing, the time of the transient processes of the formation of the full volume of the gas-liquid medium, the time of the transient process of the dispersed gas phase. The difference in levels before the gas phase generation and the stirring mode determines the value of gas retention capacity. Therefore, it was concluded that it is expedient to completely destabilise the steady-state regimes by changing the modes of action of the working body in the flow system. An additional impact on the system is the change of hydrodynamic regimes due to the unstable dynamics of the dispersed gas phase generation. The generation of this phase means the presence of energy costs for the interfacial surface establishment, which must be considered in the overall energy balance. In addition, a part of the gas phase, which existed and continues to exist in the new regime after mixing, enters the transient regime. Therefore, the most effective mixing occurs in case of compliance with the shifted mode of dosing components in a suspended state and the mechanical impact of the working body. Considering the tasks and conditions for mixing the dough, the requirements for the design of the mixer are determined, and it is established that the supply of components should last at least 45 seconds. During this period, there is hydration and a reduction in energy consumption. Such an approach intensifies mass transfer and biochemical processes under conditions of thermodynamic equilibrium with appropriate desorption bonds of the dissolved part of the gas phase and liquid, which covers a new method of mixing and allows further use in the design calculations of working chamber