Electromagnetic Fields Of Industrial Frequency Research Articles

EXPERIMENTAL STUDIES OF NOISE POLLUTION OF MECHANICAL PROCESSING PLANTS

Purpose. Determination of noise pollution at the workplace of workers of metal-cutting machines of turning, milling and drilling groups. Methodology. An experimental study of the noise load at the workplace of workers working on lathes, milling and drilling group machines. The research was carried out using a testo 816-1 digital noise level meter, Sound Forge Pro software and a mathematical package for the formation of noise dependences on the type and mode of operation of the machines. Results. An experimental study of the noise load at the workplace of workers working on metal-cutting machines, namely universal lathe-screw-cutting machines (type 1K62 and CA6136), vertical milling machines (type 6P11A and F2-250), vertical milling machine with CNC (type XS5036C) and radial drilling machine (type 2L53U). In addition, it was established that the type of machine affects the level of noise pollution at the workplace of metal-cutting machine workers. For example, the machines used for drilling are characterized by high noise values in all octave frequency ranges and all operating modes, increasing the noise level by 15 dB (16.5%) on average. Milling machines, compared to lathes, show higher noise values at medium and high octave frequencies by 7 dB (8.4%). Based on the results of the study, an adequate polynomial dependence of the fifth order was determined, which describes the noise levels relative to the frequency and corresponds to the results of the natural experiment. The resulting dependencies have practical applications in the development of component materials for simultaneous shielding of both magnetic fields of an electromagnetic field of industrial frequency and electromagnetic fields of different frequencies. Scientific novelty. The solution of this problem can be used in the future to assess the risk of occupational diseases among workers working at mechanical processing stations. Practical significance. The determined dependence will allow further consideration of the issue related to the protection of employees of mechanical processing stations from noise pollution arising during the operation of metal-cutting machines of various groups. Key words: railway, metalworking machine, noise pollution, noise.

Development of models of the electromagnetic environment in buildings and urbanized areas

A set of measures and means to control the electromagnetic situation of the environment in the territories of urban development, in buildings and individual premises has been substantiated and developed. The simulation tools show the ability to rationalize the parameters of overhead lines with voltages of 220 kV and below, which will reduce the electromagnetic load in the territories. Modeling the propagation of fields from underground high-voltage lines has established that the values of magnetic fields compared to overhead lines are lower up to 30 times. Models of propagation of electromagnetic fields of very high and ultrahigh frequency were built. Sources of electromagnetic fields of non-production origin in industrial buildings have been investigated. Uncompensated currents in power networks with nonlinear electric consumers generate magnetic fields by induction of 0.35−1.20 μT, which exceeds the maximum permissible levels of operation of computer equipment. Leakage currents on grounded metal structures generate magnetic fields with 1.52−6.75 μT. Simulation of the propagation of electric and magnetic fields of components of personal computers of controlled ranges according to the MPRII standard was carried out. Models of propagation of the magnetic field of industrial frequency around electric motors and generators with their cross sections were built. On the basis of such models, design schemes for placing equipment in production areas are selected or places of safe stay and movement of personnel are selected. The expediency of using shielding to reduce field levels to safe values due to coating surfaces with liquid protective mixtures was shown. Metal-containing composition based on water-dispersion paint makes it possible to reduce the level of magnetic field of industrial frequency by 2.5−2.6 times, electric field by 1.6−1.7 times, electromagnetic field of industrial frequency – by 1.2−1.3 times.

Investigation of the Rheological Properties of Liquid Geocement Composite Materials for Protection from Electromagnetic Fields

The article presents the results of studies of the rheological properties of liquid geocement composite materials for protection against electromagnetic fields. It has been established that an increase in the concentration of a mixture of functional iron-containing fillers from 15 to 60 wt. % in the speed range from 0.1 to 1 rpm contributes to an increase in dynamic viscosity values from 100,000 to 550,000 cP. It’s noted that with an increase in the spindle speed from 15 to 35 RPM, the values of dynamic viscosity lie in the range of 8860-3442 cP. With the same concentration changes, the plastic viscosity of the liquid composite material in the speed ranges from 10 to 25 rpm changes, respectively, to 1064.5 cP, 3096 cP, 25462 cP, which is 1.04, 3, 03 and 24.9 times exceeds the value of the plastic viscosity of the original geocement paint. It is shown that at low shear rates from 0.02 to 0.3 l/s and an increase in the concentration of the filler mixture from 0 to 60 wt. % shear forces increase sharply on average from 21.2 to 252 dynes/cm2. Increase in shear rate from 0.315 to 7.35 1/s. Shear forces gradually increase from 76 to 252 dynes/cm2. It is shown that when the content of a functional filler with a concentration of 15% liquid composite material can be applied to the substrate by pneumatic spraying; with a concentration of 30% - with a brush or roller; with a concentration of 45 to 60% using a spatula. The total shielding coefficients of the electromagnetic field of industrial frequency by layers of a mixture with a thickness of 0.22-0.25 mm with a shielding substance content of 15-60% (by weight) for geopolymer paint is up to 8.6; shielding coefficients of the electromagnetic field of microwave frequencies up to 7.9. In the presence of filler up to 60%, the reflection coefficient of the electromagnetic field of ultrahigh frequency does not exceed 0.34, while the reflection coefficient of ultramagnetic waves of ultrahigh frequency as estimated at 0.20, and the experimentally measured one is 0.22-0.23.

The influence of electromagnetic fields of industrial frequency on the male reproductive system

Introduction. The safety of exposure to the population of a growing number of sources of electromagnetic fields everywhere, both in work and at home, has become a public health problem. This article presents the results of research on the study of the potentially adverse effects of electromagnetic fields of industrial frequency on the reproductive system of personnel of energy supply institutions. The aim of the study is to explore the possible adverse effects of electromagnetic fields of industrial frequency on the male reproductive system. Materials and methods. The object of the study was 144 employees engaged in the repair and operation of power grid facilities and 40 employees who are not exposed to electromagnetic fields of industrial frequency. To assess laboratory parameters, blood samples were taken, followed by determination of the levels of total testosterone, free testosterone and globulin binding sex hormones. Results. The subjects of the main group revealed a high incidence of prostatic hyperplasia and chronic prostatitis. The employees of the main group had lower concentrations of sex hormones (p<0.05) in relation to similar indicators of the control group. A negative correlation was revealed between the levels of total, free testosterone and sex hormone binding globulin with experience (r=-0.36 p=0.009; r=-0.264 p=0.06; r=-0.349 p=0.01, respectively). Limitations of the study. The study is limited by the number of highly trained workers exposed to electromagnetic fields of industrial frequency. Conclusions. The results of the study indicate the negative impact of electromagnetic fields of industrial frequency on the reproductive system of employees engaged in the repair and operation of power grid facilities. With an increase in the length of service of employees, a decrease in the concentration of globulin binding sex hormones, total and free testosterone was found. Among workers exposed to electromagnetic fields of industrial frequency, a high prevalence of prostate pathologies was revealed.

Mapping of electromagnetic fields of industrial frequency in case of urban area

Repeated detailed mapping of values of electric field strength and magnetic induction on 2 streets in the historic center of St. Petersburg is executed. Measurements were carried out according to the existing methodical requirements and taking into account time of peak loadings of the power supply network. The individual binding of points of measurements naturally increases detail of the final map. Excesses of hygienic standards are not revealed, but the values of magnetic induction exceeding approximate safe levels according to results of foreign researches are widespread. The influence of concrete local sources of electromagnetic fields, such as signs, objects of ventilation, lighting, electrical wiring found reflection is presented by maps. The non-standard sources of electromagnetic fields in the form of large metal designs fixed to facades of buildings and subject to electrization are revealed. Growth of values of electric field strength and magnetic induction from the warm period to cold is noted.

Study of the significance of the ph of the substrate of the biogas installation during treating it with a low-frequency electromagnetic field

The article considers the issue of studying the value of pH, substrate in the process of methane fermentation in the mesophilic regime and the influence of the electromagnetic field of industrial frequency. The aim is to investigate the influence of electromagnetic fields on the pH value of the substrate during fermentation. Different types of microorganisms are involved in the process of methanogenesis, and the decisive role in it is played by methane-forming archaea, which are most sensitive to pH and should be in the range of 6.5 - 8. Therefore, it is necessary to check the effect of low frequency electromagnetic field on substrate pH. The study was performed for 25 days on two substrates, one of which was exposed to a low-frequency electromagnetic field with an electromagnetic induction of 3.5 mT. The research results show that the pH value of the substrate exposed to the electromagnetic field during the methane fermentation process was within acceptable limits, and the second substrate decreased, that is, it was acidified. Key words: methane fermentation, substrate, pH value, electromagnetic field

Evaluating Occupational Morbidity Among Energy Enterprise Employees In Industrial Region Of Kazakhstan

Our research project was aimed at studying the effects of an electromagnetic field of industrial frequency (EMF-IF) on employees of an energy company in Kazakhstan. Material and Methods — The object of our study was the health status of electricians (morbidity with temporary disability – MTD), engaged in the maintenance of power lines, relay protection systems and substations (220 and 500 kV) at an energy enterprise in Kazakhstan. The interrelation and dependence of the intensive MTD indicators on the hygienic factors at the workplace were determined, and the risks were calculated from the obtained data. Results — Unfavorable workplace conditions caused an increase in disorders of the musculoskeletal system (up to 77%), blood circulation (up to 65%), nervous system (up to 52%), skin diseases (up to 46.4%), as well as the manifold rise of the likelihood of neoplasm growth and respiratory diseases. For electricians, the relationships between the nervous system disorders (r=0.792), the circulatory system diseases (r=0.573), the musculoskeletal system ailments (r=0.672) and the EMF-IF parameters were discovered. At the same time, the dependence of the incidence rates of various diseases in workers on EMF, as well as moderate to high computed relative risks, implied the occupational genesis of worklace ailments: for nervous system – R2=0.628, cardiovascular system – R2=0.709, skin – R2=0.729, and musculoskeletal system – R2=0.413. Conclusion — As preventive measures for electricians, we recommended to wear individual exposure meters, to limit work in contact with EMF, to include an oncologist in the medical commission, and for trainees, to screen for oxidative stress proteins and chaperone proteins to exclude a predisposition to oncogenesis.

SUBSTANTIATION OF APPLICATION FEATURES OF LIQUID MIXTURES FOR SCREENING OF ELECTROMAGNETIC FIELDS

The protective and rheological properties of composite materials based on water-dispersed paint and iron ore concentrate were studied. Features of liquid mixtures application for shielding of magnetic field of industrial frequency and electromagnetic field of ultrahigh frequency were substantiated. The study of the protective characteristics and rheological properties of composite materials based on water-dispersed paint and iron ore concentrate indicates the possibility of their use for shielding electromagnetic fields of a wide frequency range. It was found that the efficiency of the composite material (total shielding coefficient and reflection coefficient of electromagnetic waves) depends on the dispersion of the shielding filler, so the particle size analysis of iron ore concentrate was performed. The analysis shows that the predominant size of iron-containing particles is 23‒24 μm, which is quite acceptable for their uniform distribution in the body of the matrix. Shielding protective material was made of water-dispersion paint with the addition of iron ore concentrate in weight quantities of 15, 30, 45, 60%. The shielding coefficients of the electromagnetic field of industrial frequency and ultrahigh frequency with different filler content were measured. It was found that if the concentration of filler exceeds 30%, both the rheological characteristics of the mixture and the shielding coefficients of electromagnetic fields are unsatisfactory. A dramatic increase in shielding coefficients occurs at a filler concentration of 40%. This mixture has acceptable adhesive properties. It was established that the shielding coefficients could be enhanced if the dispersion of the filler is increased, which will contribute to the stability of the colloidal mixture and improve the rheological properties.

Design of liquid composite materials for shielding electromagnetic fields

This paper reports the principles of design and the examined protective properties of liquid materials for shielding the electric, magnetic, and electromagnetic fields over a wide frequency range. The materials were made on the basis of iron ore concentrate and a pigment additive, with water-dispersed and geopolymer paints used as a matrix. The tests of protective properties for the electrical and magnetic components of the electromagnetic field of industrial frequency showed that the electric field shielding coefficients at a concentration of the screening substance of 15−60 % (by weight) equaled 1.1−8.6; magnetic field – 1.2−5.3. The shielding coefficients of the material based on a water-dispersed paint are lower than those of a geopolymer one, which can be explained by the oxidation of an iron-containing component and a decrease in electrical conductivity. The shielding coefficients of the electromagnetic field with a frequency of 2.45 GHz are 1.2−7.9. The highest coefficients are inherent in the material with filler made of iron ore concentrate and titanium-containing pigment powder in a ratio of 1:1. To design materials with the required (predictable) protective properties, the relative magnetic, dielectric permeability of materials was calculated. It is shown that the obtained data are acceptably the same as the results from direct measurements of magnetic and dielectric permeability and could be used to calculate the wave resistance of the material and the predicted reflection coefficient of electromagnetic waves. Thus, there is reason to assert the need to build a database on the frequency dependence of effective magnetic and dielectric permeability in order to automate the design processes of composite materials with predefined protective properties.

Влияние электромагнитного поля промышленной частоты на физико-химические свойства микро- и нанопорошков алюминия

The paper investigates the effect of an electromagnetic field of industrial frequency 50 Hz on the change in the physicochemical properties of aluminum powders of different dispersion. It was found that due to the action of the field, their sorption capacity increases, which leads to a significant change in the properties of aluminum powders.

A method for predicting stroke development in men working under the influence of electromagnetic fields of industrial frequency

The problem of studying the development of stroke in men of working age working in conditions of high occupational risk is relevant.The aim of the study was to develop a method for predicting the development of stroke in men working under the influence of electromagnetic fields of industrial frequency.We examined 98 men who had professional contact with the factor of electromagnetic radiation (EMI) of industrial frequency, aged 30 to 65 years, with work experience of 5 years or more. Two groups were identified: the first group — 56 stroke patients, the second group — 42 men diagnosed with chronic cerebral ischemia. Using the method of sequential inclusion of the studied risk factors (ForwardStepwise), those that made an independent significant contribution to the development of stroke were selected. Based on the results obtained, a logistic regression formula was created that determines the probability of stroke in patients working on installation, repair, maintenance of electrical networks and electrical equipment.The presence of influence on stroke development of the following factors was established: patient’s age (β-coefficient=–0,112, p=0,013), total cholesterol level (β-coefficient=0,782, p=0,009), smoking factor (β-coefficient=–2,8, p=0,001), alcohol abuse factor (β-coefficient=3,84, p=0,0001), presence of arterial hypertension of 2–3 degrees (β-coefficient=2,63, p=0,002). In the patient, the values of these 5 parameters are determined, then these values are substituted into the appropriate formula to calculate the value of p (X). A p (X) value greater than 0.32 indicates a high risk of stroke. The sensitivity of the proposed method was 71.4%, specificity–73.8%.The proposed method for predicting the development of stroke in men whose professional activity is associated with the installation, repair, maintenance of electrical networks and electrical equipment, can be used in medical practice: the patient is determined by the value of 5 parameters (patient’s age, total cholesterol, a history of exposure to smoke, factors alcohol abuse, arterial hypertension of 2–3 degrees), then these values are substituted into the appropriate formula. The calculation of the p (X) value can be implemented in the Excel table processor

Безопасность персонала электросетевых объектов при применении средств индивидуальной защиты от электрических полей промышленной частоты

In this paper have been considered the main principles of personnel protection against adverse influence of electromagnetic fields. The analysis of principles and criteria for protection of personnel performing service and operation of power supply network facilities and an overhead contact system has been presented. Have been tested several samples of individual protection equipment for protection of electrical personnel against electric shock, adverse influence of electromagnetic fields of industrial frequency and concomitant factors, as well as when working at railroads’ overhead contact system and overhead power transmission lines with voltage up to 1150 kV inclusively whether on the Earth or wires potential, in the case of human protection in accidental situation, triggering to pace voltage. The considered screening kits as individual protection equipment are domestic product in which have been implemented innovative developments as part of the import substitution program. Has been shown the efficiency of personnel security ensuring during works on the Earth potential and live working, including possible accidental situations.

The effect of low frequency electromagnetic fields on fluctuating asymmetry of woody plants

The paper analyzes the impact of environmental factors of physical and chemical nature on the stability of the development of three species of woody plants: common lilac, Siberian apple tree, birch tree. Determining the value of the fluctuating asymmetry index (FA) over the width of two halves of leaves was performed on plants growing in the suburban green area (control), in the suburban green area under high-voltage power lines of 220 kV (physical factor, experiment 1), as well as in the city of Krasnoyarsk in terms of air pollution by exhaust gases of cars (chemical factor, experiment 2). The values of the FA index of common lilac and Siberian apple tree, defined for the control variants, were 0.024 and 0.028, and calculated for experiments 1 and 2 were respectively equal to 0.032 and 0.039; 0.029 and 0.030. It is established that the response of common lilac and Siberian apple trees to the physical environmental factor - electromagnetic radiation of industrial frequency - which is expressed in the appearance of leaf asymmetry is stronger in comparison with the reaction to the chemical factor - exhaust gases of cars. It is shown that the value of the FA index of Siberian apple tree and common lilac can be a sensitive indicator when monitoring the anthropogenic load on the environment in the form of an alternating electromagnetic field of industrial frequency. The FA index of the birch tree, measured on the basis of the width of the right and left halves of the leaf, is less sensitive than in the case of the common lilac and the Siberian apple tree.

The Substantiation of Dose for Presowing Treatment of Cereal Seeds in Electromagnetic Field of Industrial Frequency

The Substantiation of Dose for Presowing Treatment of Cereal Seeds in Electromagnetic Field of Industrial Frequency

ЕКРАНУВАННЯ ЯК ЗАСІБ НОРМАЛІЗАЦІЇ ЕЛЕКТРОМАГНІТНОЇ ОБСТАНОВКИ РОБОЧОГО СЕРЕДОВИЩА

Виконано аналіз впливу електромагнітних полів промислової частоти на здоров’я людини. Експериментально встановлені фактичні рівні електромагнітних полів асинхронних двигунів у виробничих умовах.Розглянуті організаційні заходи та технічні засоби у вигляді захисних екранів з нормалізації електромагнітної обстановки у робочій зоні виробничих приміщень. Встановлено, що застосування захисних екранів дозволяє зменшити більше ніж на 40 % рівень індукції магнітного поля у робочій зоні. На основі регресійногоаналізу отримана математична модель залежності індукції магнітного поля асинхронного двигуна, застосування якої на етапі проектування технічних засобів захисту дозволяє оцінити їх ефективність щодо забезпечення допустимої електромагнітної обстановки на робочому місці з урахуванням характеристиквстановленого електротехнічного обладнання та технологічно можливих у виробничих умовах місць встановлення захисних конструкцій.

Measurement errors of electromagnetic fields of industrial frequency in urban areas

The universal development of electrical grid infrastructure of the cities leads to an increase in the level of electromagnetic pollution of residential and especially industrial areas. Concern of the urban population about human exposure to potential danger of negative influence of electromagnetic fields (EMF) causes the need for large-scale EMF research in urban areas. To conduct this type of study, the estimates of measurement errors of intensities of the electrical and magnetic components of the EMF should be performed. The goal of this research is to assess the EMF measurement errors of the industrial frequency in urban areas. The error estimation of EMF measurements generated by power line communication was performed using the section of the territory of Moscow’s North East, as an example. The main statistical characteristics of measurement errors were determined. It is found that, when performing 3 series of measuring, the errors reduce by 1.5-3 times. When strong EMF intensities exist, it is recommended to carry out not one but a series of measurements with subsequent averaging of the results in each investigated point of the area.

Shielding effect of reinforced concrete fences in electromagnetic fields of industrial frequency

Electromagnetic fields (EMF) are one of the main types of physical pollution of the environment in urban lands. The danger of adverse impact of EMF on human health increases with growth of electric power consumption. Therefore, the issues of protection of the population against EMF impact are becoming very important. One of the options for protection against EMF exposure is the use of reinforced concrete fences with shielding properties. Despite the simplicity of such a device against EMF, it can be stated that shielding effect assessment issues are poorly known. The objective of this paper is to assess the shielding effect of reinforced concrete fences in EMF industrial frequency. The shielding effect of the reinforced concrete fences study was conducted on the surrounding area of the thermal power plant (TPP), located on the edge of Mytishchi city of the Moscow Region. The effects of an abrupt increase in the EMF intensity in front of the reinforced concrete fence and its decrease behind the fence are revealed. It is found that these effects are associated with the concrete reinforcement impact inside the fence, in which an alternating electric current is generated. The shielding effect determines the partial reflection of EMF in front of the fence and decrease of EMF inside it. Accounting for the shielding effect of reinforced concrete fences provides perspectives of organizing the protection of the population near residential and industrial buildings, as well as protection of personnel working in the strong EMF areas.

Дослідження мікроядер у кістковому мозку щурів за поєднаної дії ендогенних нітрозамінів та електромагнітного поля промислової частоти (50 Гц)

Дослідження мікроядер у кістковому мозку щурів за поєднаної дії ендогенних нітрозамінів та електромагнітного поля промислової частоти (50 Гц)

Old cities environment transformation in the conditions of modern technogenic influence (ecological analysis of Kimry, Tver Region)

The following paper deals with the problem of historic cultural centers environment transformation on the example of Kimry, the Tver Region. The relevance of the research is defined by the fact that technogenic influence of all environment components on urban areas is actually big. The dense population, abundance of multi-storey residential buildings and social objects are combined with intensive traffic flows, existence of the household and industrial enterprises emanated considerable technogenic flows of toxic substances. The paper contains results of a complex analysis of Kimry ecological state, including assessment of soil cover and atmospheric air pollution, magnetic component of technogenic electromagnetic fields of industrial frequency, air aero ionic composition and acoustic influences. The authors show that the maximum technogenic transformation of environmental material and geophysical components is characteristic for the Kimry central part where difficult infrastructure of the modern city is inscribed in tight space of the historic center. Pollution of soil cover and atmospheric air are due to high concentration of transport and imperfection of highways network. Universal existence of electromagnetic smog and change of air aero ionic composition are caused by low layout of city lighting and electrical power supply networks wiring. As a result the authors offer a number of ways how to improve the ecological situation. Division of business parts and cultural parts of old cities and creation of recreational and tourist clusters in the cultural part could be a cardinal solution of the historic centers problem.

THE ELECTROMAGNETIC FIELDS EFFECT ON CHAOTIC DYNAMICS OF CARDIOVASCULAR SYSTEM PARAMETERS OF WORKERS OF OIL AND GAS INDUSTRY

The motion of state vector of cardiovascular system in females working on Surgut condensate stabilization plant was studied in five-dimensional phase space of states. The parameters xi of cardiovascular system in four groups of women varied within the range of VG - bounding volumes of the phase space of states, which was defined as quasi-attractor. The volumes VG were measured and compared in women of different age, affected and not affected by human-made electromagnetic fields of industrial frequency, which allowed establishing the principal differences in the dynamics of VG. In particular, women, both younger and older age groups underwent stress effect of electromagnetic fields of industrial frequency. This led to breakdown in volume of quasi-attractors in phase plane of vector (x1, x2)T where x1 - duration of cardiointervals, and x2 = dx1/dt - rate of change of x1. In fact, electromagnetic fields became stress agents for human's cardiovascular system in the North of Russian. This is shown in the framework of quasi-attractors for cardio of two groups of women. Comparison of these four groups according to the parameters of quasi-attractors showed differences though statistical differences were not significant on a number of xi parameters of whole the body state vector x (f) of person's organism living in the special northern conditions.