A Comparative Study of the Electrodes Gels’Electrical Properties in the Measurement Issues of Intrabody Communication

Intrabody communication(IBC)technology is becoming progressively more standard-ized due to its low power consumption and high security features incorporated into the third phys-ical layer of the IEEE 802.15.6 standard.Even then,there are still many challenges in normalizing the measurement issues of IBC.A major concern that should not be overlooked is the electrodes in the IBC,especially the popular use of gel electrodes.In the channel measurements,gel electrodes are commonly employed to improve the signal-to-noise ratio and prevent electrodes from falling off.In this paper,a comparative study of the electrical properties of gel was investigated during the measurement of human channel characteristics and to clarify the differences of them.Firstly,the basis of electrostatic field pole plate measurements and electromagnetic theory were introduced to interpretate how the relative permittivity and conductivity of different gels will influence the meas-urement results.Then the in vivo experiments with different gel or dry electrodes were performed to compare the differences induced by the gel.The results indicate that the influence of the gel on the human channel measurement is mainly concentrated below 400 kHz(the attenuation is re-duced by 16.7 dB on average),and the stability of the permittivity and conductivity of the gel has a direct impact on the stability of its measurement of the human channel.This result may provide a meaningful reference for the standardization of electrode usage in IBC.

A binder-free electrode for efficient H_(2)O_(2) formation and Fe2+ regeneration and its application to an electro-Fenton process for removing organics in iron-laden acid wastewater

The electro-Fenton process,with its capacity for in-situ H_(2)O_(2)formation and Fe^(2+)regeneration,is a strik-ing alternative to the traditional chemical-Fenton process.However,the frequent requirement of extra binders for electrode fabrication leads to low catalyst utilization,a complex fabrication process,and weak conductivity.Herein,a three-dimensional(3D)porous electrode was fabricated in-situ on a Ni foam(NF)substrate integrated with nitrogen-doped carbon nanotubes(N@C)derived from carbonization of zeolitic imidazolate framework-8(ZIF-8)without any binder.The resulting 900/N@C-NF cathode(synthesized at 900℃)was high in surface area,N content,and degree of graphitization,achieved high performance of H_(2)O_(2)production(2.58 mg L^(−1)h^(−1)H_(2)O_(2)/mg catalyst)at-0.7 V(vs.SCE),and enabled prompt regeneration of Fe^(2+).The electro-Fenton system equipped with the 900/N@C-NF cathode was effective in removing a diverse range of organic pollutants,including rhodamine B(Rh B),phenol,bisphenol A(BPA),nitroben-zene(NB),and Cu-ethylenediaminetetraacetic acid(EDTA),and significantly attenuating the concentration of chemical oxygen demand(COD)in the real acid wastewater,exhibiting superior activity and stability.This binder-free and self-supporting electro-Fenton cathode was thus shown to be an attractive candidate for application to wastewater treatment,particularly those rich in organics,acids,and Fe^(3+)/Fe^(2+).