Wyniki 1-3 spośród 3 dla zapytania: authorDesc:"Assel MUSSABEKOVA"

Evaluation of the risk of occupation a diseases caused by electromagnetic field generated by extra-high voltage electric installations DOI:10.15199/48.2017.05.24

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Researched were the regularities in formation of the risk of occupational disease in staff caused by industrial-frequency electromagnetic field in extra-high voltage electric installations for further evaluation. Considered were the main conditions of electrical safety systems (optimum, permissible, harmful, dangerous) and possible transitions between them depending on the magnitude of the electric power, absorbed by employee’s body. Proposed are new levels of working conditions associated with electric power effect under proposed techniques. Set forth are the results of evaluation of occupational disease risk using probit-function and the recommendations regarding the arrangements aimed at reduction thereof. Streszczenie. W pracy badano regularność w występowaniu ryzyka choroby zawodowej pracowników, spowodowane przez pole elektromagnetyczne, o częstotliwości przemysłowej w wysokonapięciowych instalacjach elektrycznych. Rozpatrywane były główne warunki bezpieczeństwa instalacji elektrycznych (optymalne, dopuszczalne, szkodliwe, niebezpieczne) oraz możliwe przejścia między nimi, w zależności od wielkości energii elektrycznej, pochłanianej przez ciało pracownika. Zaproponowano nowe poziomy warunków pracy, związane z oddziaływaniem mocy elektrycznej, związanych z proponowanymi technikami. W pracy podano wyniki oceny wystąpienia ryzyka choroby zawodowej z wykorzystaniem modelu probit oraz zalecenia, dotyczące ustaleń mających na celu ich zmniejszenie. (Ocena ryzyka wystąpienia chorób zawodowych wywołanych przez pola elektromagnetyczne generowane przez instalacje elektryczne najwyższego napięcia). Keywords: electromagnetic field, risk, disease, electric installation, electric power. Słowa kluczowe: pole elektromagnetyczne, ryzyko, choroby, instalacja elektryczna, energia elektryczna. Introduction The Extra-high voltage (EHV) electric installations of industrial frequency 330, 500, 750 kV represent one of the main components of Ukraine[...]

Analysis of hydraulic vibration drive machine for vibration abrasive processing DOI:10.15199/48.2019.04.16

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Equipment for vibration abrasive processing (VAP) is used in machine-building for performing, for example, cleaning of cast, forged, punched and heat-treated billets, parts and semi-finished products of various purposes and a wide range of products (see next chapter), [1]. Cleaning the workpieces in many cases precedes the implementation of further technological operations and plays an important role in the overall process of manufacturing parts. Such processes and machines and their implementation are well known in the machine-building industry. But most of them have a significant drawback - relatively small performance. Therefore, the problem of finding ways to increase the productivity of these machines is an important problem. Analysis of literary data and problem statement There are many types of VAP, among the most effective are: Spindle vibration abrasive treatment (fig. 1) [2] is the process of surface treatment of parts that come in contact with a vibrating abrasive working environment. Such processing is finished and does not imply changes in the accuracy of the sizes. Treatment is carried out by removing the smallest particles of the metal, its oxides, or the plastic deformation of the surface to be treated as a result of relative slip and collision with a sufficiently high speed of the treated surface and particles of the working medium. Details are given the rotation (by attaching it to the spindle of the machine) at a speed of 0.5 -1 to 7-15 m/s. The working environment is exposed to directed vibrations with a frequency of 1500 - 2000 min-1 and an amplitude of 1 - 5 mm (fig. 1) [1]. Chemically and surface-active substances can be used to intensify the processing process. The large working space, where the working environment, allows the processing of parts in the entire volume of the camera, while excluding the need for a rigid connection of the treated surface with the processing environment, and, in addit[...]

Terms of the stability for the control valve of the hydraulic impulse drive of vibrating and vibro-impact machines DOI:10.15199/48.2019.04.04

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For realization of the most effective modes vibrating influence on the processed materials and the environment is perspective vibrating (VM) and vibro-impact machines (VIM) with hydroimpulse drive (HID) [1]. The main part of the HID is pressure pulse generator, or valve-pulser (VP) [2], which provides control the operation mode of the vibrating machine. Experimental data and practice operating of hydraulic components VM and VIM, controlled by valve-pulsators, show, that under certain conditions in dynamic system stable self-oscillation processes are excited. Therefore, it is important in the theoretical and applied aspects explore the conditions of excitation and the existence of selfoscillations. These issues have particular importance when developing rational constructions of hydraulic VM and VIM. The paper [3] presents the results of the research of pressure and lateral exertion on the piston valve. The obtained results are based on the equation Reynolds and equation Navier-Stokes, are compared with variations in the aspect ratio, cross-sectional area. This research purpose is to justify the use of the equation Reynolds for the analysis operating of the piston valve during cavitation. But application the equation Reynolds and equation Navier- Stokes does not allow the develop clear analytical criteria for determine the conditions for the work stability of the piston VP. In work [4] the static and dynamic behavior of the pressure control valve with nonlinear negative characteristics is investigated. This pressure regulating valve has the property of both reducing and increasing the pressure at the outlet and actuated by a solenoid. The presented model and linear analysis explains the negative spring constant force in the low-frequency range. The fluctuations of this pressure control valve are based on the principle excitatory force, but the operation of the VP, constructively based on the principle feedback on pressure.[...]

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