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Safety assessment of electromagnetic exposure for adult and child passengers standing on the subway platform

Li Jin, Lu Mai

Archives of Electrical Engineering

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2022

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Vol. 71, nr 3

755--773

EN

The objective of this work is to evaluate the safety of adult and child passengers exposed to a radio frequency (RF) source, i.e., a leaky coaxial cable (LCX) on the subway platform. An adult model, a child model, and an LCX model have been numerically designed in COMSOL Multiphysics software. The distributions of the induced electric field (E-field), specific absorption rate (SAR), magnetic field ( H-field) and the head temperature increase in adult and child passenger models were calculated at 900 MHz. The induced fields in the passengers were compared with that without screen doors. The results show that the E-field, SAR and H-field in the whole body of the child are 2.00 × 10 -2 V/m, 1.07 × 10 -7 W/kg, and 2.94 × 10 -4 A/m, respectively. The E-field, SAR and H-field in the central nervous system of the child are 1.00e × 10 -2 V/m, 2.44 × 10 -8 W/kg, and 2.41 × 10 -4 A/m, respectively. The maximum values of the E-field, SAR and H-field in the adult passenger are 1.49–2.34 times higher than those of the child. The E-field, SAR, and H-field in the passenger models without a screen door are larger than those with a screen door. The screen door has a partial shielding effect on the RF electromagnetic field. The values of the maximum temperature that increases in adult and child head tissue are 0.2114 and 0.2111℃ after waiting 6 minutes exposure, respectively. All calculated results are well below the International Commission on Non-Ionizing Radiation Protection (ICNIRP) limits for general public exposure, indicating that RF electromagnetic exposure caused by the LCX on the subway platform is not a threat to passenger’s health.

2

Study on the distribution of SAR and temperature in human brain during radio-frequency cosmetic treatment

Qi Xinzhe, Lu Mai

Archives of Electrical Engineering

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2021

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Vol. 70, nr 1

115-127

EN

This paper established a radio-frequency electrode model and human head modelused in RF cosmetic instruments. The distribution of electric field strength, a specific absorption rate (SAR), and temperature distribution in the human brain at 1 MHz and 6 MHz were studied and the results compared with the International Commission on Non-ionizing Radiation Protection (ICNIRP) guidelines. The results showed that under those two frequencies the maximum value of electric field strength in the human brain was 1.52 V/mand it was about 5.4% of the ICNIRP basic restrictions, the maximum SAR in human brain was about 2.21×10−3W/kg, which was far less than 2 W/kg of ICNIRP basic restrictions, the maximum temperature of the human brain was 37.6 located in the wounded skin, which was the same as the normal temperature 37. Since all the results were within the ICNIRP basic restrictions, the electromagnetic exposure generated by the RF cosmetic electrode will not pose a threat to the human health.

3

Narażenia sprzętu elektronicznego promieniowaniem elektromagnetycznym – sposoby generacji i metody ochrony

Kołodziejski J. F., Kubiak I., Łysko J. M.

Przegląd Elektrotechniczny

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2015

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R. 91, nr 11

37-40

PL

W pracy przedstawiono przyczyny zainteresowania kwestią narażeń sprzętu elektronicznego promieniowaniem elektromagnetycznym. Podano przykłady generatorów impulsowych pól elektromagnetycznych dla celów wojskowych. Szerzej omówiono metody ochrony sprzętu elektronicznego przed oddziaływaniem pól elektromagnetycznych. Zwrócono uwagę na wymagane wyposażenie do prowadzenia badań laboratoryjnych odporności sprzętu elektronicznego na oddziaływanie pól elektromagnetycznych.

EN

The reasons of interest in problems of electromagnetic radiation threat of electronic systems are given. Some examples of pulse electromagnetic fields generators for military purposes are presented. The methods of protection of electronic equipment and systems against electromagnetic radiation are reviewed.. Remarks on requirements of laboratory testing of electronic systems immunity against electromagnetic radiation are also quoted.