3 resultados para Body, Human

em Repositório Científico do Instituto Politécnico de Lisboa - Portugal


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The big proliferation of mobile communication systems has caused an increased concern about the interaction between the human body and the antennas of mobile handsets. In order to study the problem, a multiband antenna was designed, fabricated and measured to operate over two frequency sub bands 900 and 1800 MHz. After that, we simulated the same antenna, but now, in the presence of a human head model to analyze the head's influence. First, the influence of the human head on the radiation efficiency of the antenna has been investigated as a function of the distance between the head and the antenna and with the inclination of the antenna. Furthermore, the relative amount of the electromagnetic power absorbed in the head has been obtained.

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The big proliferation of mobile communication systems has caused an increased concern about the interaction between the human body and the antennas of mobile handsets. In order to study the problem, a multiband antenna was designed, fabricated and measured to operate over two frequency sub bands 900 and 1800 MHz. After that, we simulated the same antenna, but now, in the presence of a human head model to analyze the head's influence. First, the influence of the human head on the radiation efficiency of the antenna has been investigated as a function of the distance between the head and the antenna and with the inclination of the antenna. Furthermore, the relative amount of the electromagnetic power absorbed in the head has been obtained. In this study the electromagnetic analysis has been performed via FDTD (Finite Difference Time Domain).

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Endocrine disrupting chemicals (EDCs) are exogenous agents that have the ability to interfere with/or mimic estrogenic hormones and, therefore can simultaneously and differentially trigger specific signaling pathways responsible for the nature and magnitude of biological responses in diverse cell types. Human exposure to EDCs, particularly at low-doses, is ubiquitous, persistent and occurs in complex mixtures. These compounds can bioaccumulate in lipid compartments of tissues forming a mixed “body burden” of contaminants of different origins. Although the independent action of chemicals has been considered the main principle in EDCs mixture toxicity, several effects cannot be predicted when analyzing single compounds individually. Based in a revision of the literature, focused in studies that evaluated EDCs mixtures, we hypothesize the scenario of a pregnant woman environmentally exposed to three different EDCs as a potential real scenario of human exposure supported by data describing where exposure to these compounds occur.