Class Of Working Conditions Research Articles

Optimizing presetting attributes by softcomputing techniques to improve tapered roller bearings working conditions

Double-row Tapered Roller Bearings are mechanical devices that have been designed to support a combination of loads that are fixed on an optimal presetting to ensure correct working conditions. The emergence of high contact stresses, fatigue spalling and pitting on the bearing railway makes it important to have a tool that enables knowing in advance whether certain presetting loads will lead to excellent working conditions or the opposite. This work proposes a methodology to classify the working condition on the basis of the values of presenting loads on four classes. To achieve this goal, a three-dimensional Finite Element (FE) model was generated. Later, a design of experiments was designed to provide the greatest amount of information by reducing the computational cost of the simulations based on FE models. Then, one of the four classes of working conditions was assigned to each of the experiments. Later, a statistical analysis and machine learning techniques were used to create classification models. Feature transformation and reduction, algorithm parameter tuning and validation methods were used to achieve robust classification models. The best results were obtained based on flexible discriminant analysis. As it provided acceptable accuracy, both the methodology and final model were validated.

CONDITIONS OF THE DEVELOPMENT AND PECULIARITIES OF THE COURSE OF RESPIRATORY DISEASES IN SMELTERS OF TITANIUM ALLOYS

The working conditions, occupational and non-occupational risk factors, prevalence rate and peculiarities of the course of respiratory diseases in smelters of titanium alloys were studied. Working conditions of smelters are estimated as harmful (class of working conditions: 3.3-3.4.) due to factors: heating microclimate, chemicals (chlorine and hydrochloride, sulfur dioxide, nitrogen oxide), industrial dust. A feature of the respirable dust fraction is the high content of titanium oxide particles of the PM10 dimension. There was made an analysis of the health status of workers exposed to industrial dust, depending on the length of service. Diseases of the upper respiratory tract in smelters of titanium alloys were shown to be prevalent, simple catarrhal nasopharyngitis prevails with the subsequent formation of atrophic rhinitis, its prevalence rate among smelters of titanium alloys increases with the experience. The peculiarity of the development of diseases of the upper respiratory tract in smelters of titanium alloys are: deterioration of nasal breathing in workers with experience of from 1 year to 5 years already, in patients with experience from 10 to 15 years the prevalence of catarrhal nasopharyngitis and atrophic rhinitis as its outcome in cases with experience from 15 to 20 years. The bronchial damage in the smelters of titanium alloys develops under the experience more than 5 years. The clinical forms are dominated by the phenomena of catarrhal bronchitis followed by obstruction of the bronchi progressing with the experience, with the formation of irreversible ventilation disorders. With the depletion of antioxidant protection, as a rule, with long duration of the exposure of up to 10 years, aseptic inflammation is formed, which is pronounced clinically as catarrhal endobronchitis. This is a partially reversible pathological process. The described features of the development and course of respiratory diseases in smelters of titanium alloys should be taken into account during periodic medical examinations in order to timely prevent them

Hygienic assessment of occupational risks medical personnel during physiotherapy treatments

This article deals with the problem of hygienic assessment of occupational risks of medical personnel involved in performing physiotherapeutic procedures for the purpose of rehabilitation of various population groups. Different degrees of occupational risk, classes of working conditions and indices of occupational morbidity for doctors and nurses with hydrotherapy, mud therapy, paraffin treatment, radon procedures and therapeutic massage are determined. A set of preventive measures has been developed to prevent occupational morbidity and increase morbidity with temporary disability.