In our time the use of devices, emitted microwave radiation such as mobile phones, wireless fidelity (Wi-Fi) routers, etc. is increased rapidly. The full effects of the influence of such fields on society have not been finally elucidated. In many developed countries have begun to control the levels of electromagnetic radiation which appeared in various educational institutions, but these studies are single and not massive. Therefore, continuous monitoring of the distribution of high-frequency fields in cities of Ukraine is required. In the period 2015–2016 years we have made analysis of electromagnetic fields with a frequency of 2,4 GHz (Wi-Fi-diapazon) in all district of the city of Dnipro. For registration such waves and their initial processing was used computer program Wi-Fi Analyzer v.1.0. This program worked on the tablet and governed by operating system Android 4.0. The program presents the output data on the screen of tablet as a set of graphs which showing the power of all Wi-fi signals (in dBm) at a given point of space. For investigation the power level of the field in the nearest environment from the source a standard router TL-WR841N was used. Carrying the tablet in the direction from the router gave a set of data on the standard attenuation of electromagnetic waves, passing only through air or through the air and walls of the house. The walls of the houses reduced the sought signal but did not change the characteristic of its attenuation related to the distance. In investigation revealed that the main sources of Wi-Fi pollution in Dnipro was a routers, each of which was identified by name, by power and the point of locations in the city. The measurements of electromagnetic fields were carried out in all eight districts and nearly 500 streets of Dnipro-city. In a result we analyzed about 12000 signals of Wi-Fi-routers. The highest power Wi-Fi field (50–60 dBm) was found in the downtown district with a large number of large apartment buildings, offices and public places of entertainment the population. The districts of Dnipro in which are located the private houses, factories and place of construction buildings – less vulnerable from Wi-Fi contamination (average force 70–90 dBm). The number of routers in the «Central» and «Cathedral» district was the maximum for the city (> 10,000 units for each of them), the minimum number of routers is noted for «Samarskiy» district (≈ 600 units). In certain parts of the city where is the natural ravine was found a significant reduction of electromagnetic waves energy value. According to power value of Wi-Fi-fields in different locations of the city of Dnipro we created a map their total spatial distribution. On this map, the values of the electromagnetic field power in the city are indicated in different colors, which is convenient for understanding current situation of anthropogenic pollution. In general, the tendency to increase the total number of sources of electromagnetic pollution in the city and increase their total power was detected. It is concluded that the development of maps with a certain level of background contamination of electromagnetic waves with different frequencies are important for monitoring the overall ecological state of cities and for increase understanding of the impact of such pollution and possible negative effects on public health of Ukraine.
DESIGN ANALYSIS AND CONSTRUCTION OF ENERGY HARVESTING COAXIAL HELICOPTER