scholarly journals Modelling and Evaluation of the Absorption of the 866 MHz Electromagnetic Field in Humans Exposed near to Fixed I-RFID Readers Used in Medical RTLS or to Monitor PPE

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4251
Author(s):  
Patryk Zradziński ◽  
Jolanta Karpowicz ◽  
Krzysztof Gryz ◽  
Grzegorz Owczarek ◽  
Victoria Ramos
Keyword(s):  
Electromagnetic Field ◽  
High Frequency ◽  
Thermal Effects ◽  
Microstrip Antennas ◽  
The Body ◽  
Uhf Rfid ◽  
Exposure Limits ◽  
Passive Tags ◽  
Radiated Power ◽  
Rfid Readers

The aim of this study was to model and evaluate the Specific Energy Absorption Rate (SAR) values in humans in proximity to fixed multi-antenna I-RFID readers of passive tags under various scenarios mimicking exposure when they are incorporated in Real-Time Location Systems (RTLS), or used to monitor Personal Protective Equipment (PPE). The sources of the electromagnetic field (EMF) in the modelled readers were rectangular microstrip antennas at a resonance frequency in free space of 866 MHz from the ultra-high frequency (UHF) RFID frequency range of 865–868 MHz. The obtained results of numerical modelling showed that the SAR values in the body 5 cm away from the UHF RFID readers need consideration with respect to exposure limits set by international guidelines to prevent adverse thermal effects of exposure to EMF: when the effective radiated power exceeds 5.5 W with respect to the general public/unrestricted environments exposure limits, and with respect to occupational/restricted environments exposure limits, when the effective radiated power exceeds 27.5 W.

scholarly journals Evaluation of SAR in Human Body Models Exposed to EMF at 865 MHz Emitted from UHF RFID Fixed Readers Working in the Internet of Things (IoT) System

2020 ◽  
Vol 2 (1) ◽  
pp. 11
Author(s):  
Patryk Zradziński ◽  
Jolanta Karpowicz ◽  
Krzysztof Gryz ◽  
Victoria Ramos
Keyword(s):  
Radio Frequency Identification ◽  
The Body ◽  
Uhf Rfid ◽  
Exposure Limits ◽  
Passive Tags ◽  
Radiated Power ◽  
Frequency Identification ◽  
Human Body Models ◽  
Rectangular Microstrip Antenna ◽  
The Internet Of Things

The aim of this ongoing study was to evaluate the specific energy absorption rate (SAR) values in the body of a person present near-fixed readers of ultra-high frequency (UHF) radio frequency identification (RFID) passive tags incorporated in real-time locating systems (RTLS), operating at a frequency range of 865–868 MHz, considering various exposure scenarios. The modelled electromagnetic field (EMF) source was a rectangular microstrip antenna designed at resonance frequency in free space at 865 MHz. The SAR values in the body exposed to EMF 5 cm away from the UHF RFID readers need consideration with respect to general public exposure limits, when the radiated power exceeds 8 W.

scholarly journals Assessment of the Electromagnetic Field Exposure during the Use of Portable Radios in the Context of Potential Health Effects

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6276
Author(s):  
Jarosław Kieliszek ◽  
Joanna Wyszkowska ◽  
Jaromir Sobiech ◽  
Robert Puta
Keyword(s):  
Electromagnetic Field ◽  
Health Effects ◽  
Computer Simulations ◽  
Thermal Effects ◽  
The Body ◽  
Control Group ◽  
Field Exposure ◽  
Potential Health ◽  
Portable Radio ◽  
Neurophysiological Tests

The paper presents research on the electromagnetic hazards related to the flow of electric currents throughout the bodies of employees using portable radios. The values often exceed established limits, which may lead to potential dysfunctions of the body and affect the safety of performed professional duties. The measurements of the electric field (E-field) distribution of a typical commercial portable radio, the limb contact current calculations, and the computer simulations determining a specific absorption rate (SAR) were supplemented with pilot neurophysiological tests. The assessment indicated a large spatial variability of the E-field strength around the devices. The head of the operator and the hand holding the radio were often in the electromagnetic field (EMF), which exceeded the established limits. The calculated SAR values ranged within the permitted limits. The conducted neurophysiological tests showed no effects of EMF exposure in comparison to the control group. The assessment of exposure to the EMF using a portable radio is initially performed by analyzing external measures: both computer simulations and measurements of workers’ limb currents. The SAR values exclude thermal effects; however, they do not eliminate potential neuromuscular effects. More neurophysiological tests are needed to obtain a broader picture of possible health effects.

scholarly journals An Evaluation of Electromagnetic Exposure While Using Ultra-High Frequency Radiofrequency Identification (UHF RFID) Guns

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 202 ◽  
Author(s):  
Patryk Zradziński ◽  
Jolanta Karpowicz ◽  
Krzysztof Gryz ◽  
Victoria Ramos
Keyword(s):  
High Frequency ◽  
General Public ◽  
Environmental Influence ◽  
Uhf Rfid ◽  
Exposure Limits ◽  
Case Scenario ◽  
Worst Case ◽  
Ultra High Frequency ◽  
Close Proximity ◽  
Radiofrequency Identification

The aim is to evaluate specific absorption rate (SAR) values from exposure near handheld ultra-high frequency radiofrequency identification readers (UHF RFID guns—small electronic devices, or even portable computers with relevant accessories—emitting up to several watts of electromagnetic field (EMF) to search for RFID sensors (tags) attached to marked objects), in order to test the hypothesis that they have an insignificant environmental influence. Simulations of SAR in adult male and female models in seven exposure scenarios (gun near the head, arm, chest, hip/thigh of the operator searching for tags, or near to the chest and arm of the scanned person or a bystander). The results showed EMF exposure compliant with SAR limits for general public exposure (ICNIRP/European Recommendation 1999/519/EC) at emissions up to 1 W (reading range 3.5–11 m, depending on tag sensitivity). In the worst-case scenario, guns with a reading range exceeding 5 m (>2 W emission) may cause an SAR exceeding the general public limits in the palm of the user and the torso of the user, a bystander, or a scanned person; occupational exposure limits may be exceeded when emission >5 W. Users of electronic medical implants and pregnant women should be treated as individuals at particular risk in close proximity to guns, even at emissions of 1 W. Only UHF RFID guns emitting below 1 W may be considered as environmentally insignificant EMF sources.

scholarly journals Effect of high-frequency electromagnetic field on microstructure of mold flux

2020 ◽  
Vol 39 (1) ◽  
pp. 368-376
Author(s):  
Xingjuan Wang ◽  
Hebin Jin ◽  
Liguang Zhu ◽  
Ran Liu ◽  
Tushun Song
Keyword(s):  
Electromagnetic Field ◽  
High Frequency ◽  
Mold Flux ◽  
Film Structure ◽  
Glass Layer ◽  
Slag Film ◽  
Flux Flow ◽  
Layer Form ◽  
Finite Element Software ◽  
High Frequency Electromagnetic Field

AbstractSoft-contact of molten steel can be achieved by applying a high-frequency electromagnetic field above the mold of continuous casting, which can effectively eliminate surface defects and achieve billets with no cracks and no oscillation marks. It also has some influence on the mold flux. In this study, the effect of a high-frequency electromagnetic field (20 kHz) on a mold flux flow field was simulated using a finite element software, and the slag film was extracted using a slag film simulator. The effect of the high-frequency magnetic field on the microstructure of the mold flux was analyzed using X-ray diffraction, Raman spectroscopy, and mineral phase testing. The results show that the high-frequency electromagnetic field disrupts the orderly movement and increases the movement rate of the liquid flux. The precipitate phase of the slag film did not change, but the silicate dimer Q1 decreased, the chain Q2 increased, and the network degree was increased. The slag film structure changed from the original two-layer form of crystalline layer–glass layer into a three-layer form of crystal layer–glass layer–crystal, and the crystallization ratio increased by 35% on average. The grain-size melilite granularity was reduced from the original 0.12 to 0.005 mm.

Software-Defined RFID Readers: Wireless Reader Testbeds Exploiting Software-Defined Radios for Enhancements in UHF RFID Systems

2021 ◽  
Vol 22 (3) ◽  
pp. 46-56
Author(s):  
Georg Saxl ◽  
Lukas Goertschacher ◽  
Thomas Ussmueller ◽  
Jasmin Grosinger
Keyword(s):  
Uhf Rfid ◽  
Rfid Systems ◽  
Software Defined Radios ◽  
Rfid Readers

High Frequency Vibration Analysis of Automotive Body Panels with Damping Materials

2010 ◽  
Vol 36 ◽  
pp. 293-296
Author(s):  
Yoshio Kurosawa ◽  
Takao Yamaguchi
Keyword(s):  
High Frequency ◽  
Large Scale ◽  
The Body ◽  
Viscoelastic Damping ◽  
Fe Model ◽  
Test Results ◽  
Automotive Body ◽  
Modal Damping ◽  
Practical Tool ◽  
Damping Materials

We have developed a technique for estimating vibrations of an automotive body structures with viscoelastic damping materials using large-scale finite element (FE) model, which will enable us to grasp and to reduce high-frequency road noise（200～500Hz）. In the new technique, first order solutions for modal loss factors are derived applying asymptotic method. This method saves calculation time to estimate modal damping as a practical tool in the design stages of the body structures. Frequency responses were calculated using this technique and the results almost agreed with the test results. This technique can show the effect of the viscoelastic damping materials on the automotive body panels, and it enables the more efficient layout of the viscoelastic damping materials. Further, we clarified damping properties of the automotive body structures under coupled vibration between frames and panels with the viscoelastic damping materials.

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