In recent years, in sanitary science the interest in issues of young people has dramatically increased, that has been actualized by the necessity of a new objective assessment of the role of the youth in modern sanitary-ecological, sociocultural and economic processes. In this regard, a special interest is aroused by young students, the health of whom is determined largely by the condition of the habitat. So far complex assessment ofriskfactors in urbanized areas, prioritization of impacts, the establishment ofpriority impacts, the detection of informative territorial environmentally dependent indices ofpopulation health are presented to be important tasks in the solution of the regional challenges. The aim of this work was the assessment of the state of health of students of the Bratsk State University, residing in conditions of ecological trouble. In the territory of the city of Bratsk the environmental situation is characterized by long term multi-component air pollution with highly toxic vehicular and industrial emissions. In the work throughout the 4 years following-up there was executed an assessment of the physical development of students, there was determined structure and revealed the an increased level of morbidity rate of students of Bratsk state University in terms of educational space, which is characteristic for territories of ecological trouble in the city of Bratsk. Parameters of physical development of students in dynamics of training were established to be not liable to variation. It confirms the stability of the morphological signs as compared to functional ones. In the analysis of dynamics of indices of the harmonicity ofphysical development there was revealed a gain in the proportion of harmoniously developed students by the end of training. Physiometric indices of students to the fourth course of training were characterized by the increase offunctional capabilities of the respiratory system.The indices of the cardiovascular system performance had a tendency to the growth of the hypertensive response in boys and the increase in the number of people with normotensive response to physical stress by the end of training. To the IV course of training there was observed the increase in the number of young boys with stringency of mechanisms of adaptation to stress, whereas in young girls satisfactory adaptation was seen.
Wood modification with the improvement of its physical and mechanical properties is a promising way to increase the commercial quality of the material and enhance its sustainable use. This article presents the results on developing a model for impregnation with water of fine coniferous and non-coniferous wood by centrifugal processing techniques. The mathematical modeling is based on Darcy’s law. According to the model representation, the impregnation rate of the wood assortment is proportional to the pressure ratio of the treating solution. The proportionality factor is a constant value that depends on the breed of wood. Performed comparative analysis revealed the perfect consistency of calculations made using the formula of a centrifugal model with the experimental data. According to the analysis of impregnation rate time dependencies, the main saturation of the treated sample with liquid (70%) occurs in 1/3 of the complete cycle time. Besides, the established model allows determining with high accuracy the impregnation time as a function of atmospheric pressure, rotational speed, and the ratio of assortment wood length to centrifuge platform radius for different wood breeds. Further studies are planned on evaluating the effect of different liquids viscosity on the kinetics of wood impregnation as well as determining the applicability of the proposed model.
In rock blasting, inhomogeneity and fracture have a marked influence on the resulting fragment-size composition.Various authors [1][2][3][4][5] have investigated fragment-size composition taking account of the original jointing of the rock.They make an a priori assumption on the statistical distribution of the fragment sizes, then choose experimental data confirming the assumed distribution law. However, the experimental data on fragment-size composition of blasted rock can be equally well represented by most two-parameter positively asymmetrical distributions [6]. Experimental verification of these laws is very difficult. It is hard to check the agreement between the theoretical and empirical distributions with the aid of some criterion of agreement, because even from the value of the calculated criterion we can often conclude that the experimental data are equally consistent with several distribution laws.The choice of distribution should be based either on the physical essence of the process of cruching rocks by blasting, or on a study of the statistical laws of fracture of inhomogeneous jointed media.This latter basis was used in the investigations made by the present authors.To study the influence of the structure of a broken medium on the resulting fragmentsize composition due to blasting, we performed experiments on inhomogeneous and block models. The inhomogeneous models were made from granite fractions (structural units) measuring 10-20, 20-30, and 30-40 mm (compressive strength 1.2.108 N/m 2) cemented by a 1:6 sand--cement mixture (compressive strength 1.42-107 N/m 2) or by rosin (compressive strength 2.106 N/m2).The granite fractions were placed in a mold measuring 0.2 x 0.2 x 0.2 m which was filled with the cementing material. We prepared six types of models in this way (four types with granite fractions cemented with sand--cement solution and two types cemented with rosin).To study how the structure of the medium and the specific explosives consumption influence the intensity of crushing of the model material, we used PETN charges weighing 50, i00, 200, 400, and i000 mg (charge density 0.9 g/cmS).We performed 4-6 experiments with the same charge weight on each type of model.The averaged results are listed in Table I.The initial dimensions of the units of stronger material (granite) determine the position of the maximum of the fragment-size distribution. If the model contains initial fractions measuring 10-20 and 30-40 mm, then after the blast we observe two maxima on the fragment-size composition distribution (Fig. 2). With a low specific explosives consumption we get fragments with larger dimensions than those of the initial fractions owing to incomplete fracture of the cementing material.This explains the maximum for fractions coarser than those of the original material.The influence of the charge size on the fragmentation results was investigated on models containing the 10-20 mm granite fraction cemented by a sand--cement mixture (Fig. 3) and also on models based on the 20-30 mm fraction cemented...
The paper considers environmental and health assessment of the soil cover quality in Bratsk, the Irkutsk Region. The purpose of the research: environmental and health assessment of soil pollution impact on the public health when exposed to chemicals formed during aluminium production. The method of analyzing the total fluoride content (in mg/kg of soil) on the horizons of 0-5 cm and 5-10 cm is used; a volume of the oral, inhaled, and cutaneous intake of this substance from the soil is assessed. Based on the risk assessment of multi-mediated exposure to chemicals, a quantitative characteristic of the total intake of fluoride compounds is given. It’s been found that of all the sampling points in Bratsk, the most contaminated with fluoride compounds is the village of Chekanovsky (the maximum content is 1,722 mg/kg); the soils of the village of Padun are less polluted (the maximum content is 48 mg/kg). The total average daily intake of fluoride compounds for the adult is determined, the values of them don’t exceed the human’s need for fluoride when calculated per kg/body weight. The most sensitive group to environmental pollution, including soil, by fluoride compounds, is children.
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