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(a) Five-layer cell model. (b) Results of E-field distribution onto the X-Y-plane, and particularly along the X-axis.
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The understanding of the modalities of interaction of electromagnetic (EM) fields with biological material is a key point in the identification of possible induced effects. Since the beginnings of bioelectromagnetic research studies, most of the attention has been focused on the effects on nervous systems and neuronal cells. The importance of this...
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... distribution at a microscopic level, and specifically around the membrane of a cell. The model considered in this paper is based on an approach proposed first in [27] and then a second time in [24]. Just recalling this second one, it is composed of four spher- ical concentric layers, with an external extracellular solution, as depicted in Fig. 3(a). The model characteristics are described in Table ...
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... use of such a model, in conjunction with Mie's theory [36], allows the derivation of an analytical solution to the dosi- metric problem. An example of the solution is given in Fig. 3(b), where the spatial variation of the EM-field level is evaluated for a plane wave incident upon the spherical model. Further studies and preliminary results about it can be found in [23] and [37]. Observing Fig. 3(b), it is possible to notice on the equatorial plane a strongly nonuniform distribution depending on the value of the ...
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... theory [36], allows the derivation of an analytical solution to the dosi- metric problem. An example of the solution is given in Fig. 3(b), where the spatial variation of the EM-field level is evaluated for a plane wave incident upon the spherical model. Further studies and preliminary results about it can be found in [23] and [37]. Observing Fig. 3(b), it is possible to notice on the equatorial plane a strongly nonuniform distribution depending on the value of the angular position. It is possible to use this kind of spatial in- formation to further improve dosimetric evaluation, attempting to obtain an effective EM field in the point of interest, down to the scale of single ...
Citations
... The second example describes the optimization of a plasma coating for textile fabrics meant for electromagnetic shielding. The rationale of the example is given by the fact that electromagnetic radiation is currently a major problem due to the numerous sources of pollution, mobile phones, Wi-Fi connections, Bluetooth devices, etc. affecting human health [16] and causing interference with the proper operation of other electronic devices [17]. The presented educational example includes some technical aspects, such as the following: ...
Mastering software knowledge for the design of textile fabrics is especially important for students of higher education and offers substantial competitive advantages within the world of work. The Erasmus+ project OptimTex has prepared up-to-date educational materials as a response to the digitization requirements of Industry 4.0 in the textile field. This paper presents the content of an e-learning module conceived by the coordinator of the Erasmus+ OptimTex project. The module addresses the design of experiments in the field of technical textiles for electromagnetic shielding, with the following technical aspects: two input parameters, the weft fabric density (number of yarns per 10 cm) and the thickness of the plasma-coated metallic (copper) layer on both sides of the fabric (nanometre) and one result variable, the
electromagnetic shielding effectiveness of the fabrics (dB) at 100 MHz. A Box-Wilson central composite design was applied to optimize shielding effectiveness related to both input parameters. Software such as Excel, MATLAB and MODDE was applied to compute and cross-check the response surface modelling.
... The pioneer work was taken by exploring firing activities in Hodgkin-Huxley neuron model under EMR, in which the EMR was regarded as a field [14]. Then, the effects of EMR on neurons have been quantitatively evaluated [15,16]. However, with the energy absorption assumption, it was predicated that neuronal media can absorb the EMR and then translate the EMR into a polarized current through the media [2]. ...
Electromagnetic radiation can impact the neuron firing activities. To disclose its dynamics effect, a memristor-based three-dimensional (3D) non-autonomous Wilson neuron model is built with the consideration of electromagnetic radiation. The number and the stability of time-varying equilibrium states change over the time, leading to the occurrence of complex neuron dynamics. Then, multiple numerical tools are employed to disclose these neuron dynamics induced by electromagnetic radiation. It is found that the proposed neuron model has different non-chaotic firing activities of periodic/quasiperiodic/chaotic spiking and periodic/quasiperiodic bursting behaviors with respect to the amplitude and frequency of the electromagnetic radiation. This reflects that the electromagnetic radiation can trigger complex non-chaotic behaviors in neurons. Afterwards, a microcontroller unit-based (MCU-based) hardware platform is implemented and hardware experiments are executed. The physically captured phase trajectories and time-domain waveforms well validate the numerically simulated ones. Studying these non-chaotic behaviors can assistant us to understand the intrinsic nature of firing activities in neurons.
... The use of various electronic devices, mobile phones and other gadgets has yielded significant pollution from electromagnetic (EM) radiation in our environment [1]. Shielding is needed in many applications since non-ionizing radiation from various sources may cause interference (EMI) with other electronic devices or even cause harmful effects on human health [2,3]. Due to their advantages when compared to metallic shields, such as low weight, good mechanical strength, adaptability to various shapes of objects for shielding, as well as costeffectiveness, textile materials with electric conductive properties offer a proper solution on these aspects [4]. ...
The paper proposes the analytic modelling of flexible textile shields made of fabrics with inserted conductive yarns and metallic plasma coating in order to calculate their electromagnetic shielding effectiveness (EMSE). This manufacturing process is highly innovative, since copper plasma coating improves EMSE on the fabrics with inserted conductive yarns of stainless steel and silver with 10–15 dB in the frequency range of 0.1–1000 MHz, as shown by the measured EMSE values determined according to the standard ASTM ES-07 via the Transverse Electromagnetic (TEM) cell. On the other hand, modelling of EMSE for such conductive flexible shields gives an insight on estimating EMSE in the design phase of manufacturing the shield, based on its geometric and electrical parameters. An analytic model was proposed based on the sum of EMSE of the fabric with inserted conductive yarns and EMSE of the copper coating. The measurement results show close values to the proposed analytic model, especially in case of fabric with conductive yarns having stainless steel content.
... As noted in [36][37][38][39] , the exogenous sinusoidal signal was con- sidered to induce a voltage perturbation over the transmembrane voltage and it was modeled as a voltage generator in series with the equivalent circuit of the stochastic HH model. The amplitude of the applied signal is 500 μV and, in the absence of noise, it can- not force the neuron system to switch from resting to firing state and vice versa. ...
A processing technique for decoding the information transferred from a sinusoidal input to the output spike sequence of a neuron model is a desirable tool for understanding the encoding principles of neuronal systems. An automatic decoding procedure, already proposed by the authors, is based on an improved version of the Signal to Noise Ratio (SNR) calculation and requires a knowledge of both spontaneous (in absence of input signal) and stimulated (in presence of input signal) neuronal activities. In this work, an automatic decoding procedure based on high-pass homomorphic filtering is developed that provides performances comparable or better than that obtained with the improved SNR. The advantages of not requiring the neuronal spontaneous activities, as most SNR methods do, are a procedure simplifications, a reduction of the amount of data needed to decode the information, and the possibility of application to contexts where the neuronal spontaneous activity is not available.
... The channel response was reported to be sensitive to both the frequency and intensity of electromagnetic stimulation which was shown in a stochastic modeling [26]. The mobile communication frequencies effect at cellular level and the time behavior level was modeled via a proposed model and was validated by experimental results [27]. The initiation, propagation and characteristics of dendritic action potentials (spikes) which turn out to be complex and can behave in a highly nonlinear fashion have been observed in many cells such as hippocampal interneurons [28] and cerebellar purkinje cells [29]. ...
The effect of electromagnetic radiation on neurons has been studied extensively both experimentally and computationally. As for dendrites, these studies are mostly limited to the morphological aspects such as branching and not basically conductance. The effect of low frequency electric field radiation on the electrophysiological characteristics of dendrites is studied theoretically. The study is based on incorporating the effect of electric field components inside the modified cable equation and considering the geometry variation of the structure. The effect of different ionic components has been included with the aid of the Connor-Stevens model and the governing equation is then solved computationally. The results of the simulation indicate that the dendrites are physiologicaly sensitive to the radiation field. Variation in the electrophysiological aspects, including the firing rate, the conduction velocity, the pulse broadening and the latency are more pronounced in response to the external stimuli in the dendrites and are enhanced in the frequency range of 100 Hz to 10 kHz. To the best of our knowledge, the interaction of an electric field with non-uniform radius dendrites has not been studied nor modeled. The results of this study could be useful not only as a barrier to neurotoxicity of low frequency radiation, but also as a potential application in the treatment of neurophysiological disorders.
... 1,2 EM pollution may cause operational malfunction within the electronic neighborhood as well as violate the intrinsic EM field of human beings. 3,4 The consequential hazards may be a loss of money, energy sources, time, or even precious human life. 5 Hence, high-performance electromagnetic-interference (EMI) shielding materials are required to isolate the internal electronics from the surroundings. ...
Despite tremendous efforts, fabrication of lightweight conductive fabrics for high-performance X-band electromagnetic interference (EMI) shielding remains a daunting technical challenge. We herein report an ingenious and efficient strategy to deposit polyaniline/cobalt-nickel (PANI/Co-Ni) coatings onto lyocell fabrics that involved consecutive steps of in situ polymerization and electroless plating. The PANI-Co-Ni trinary-component system successfully induced a synergistic effect from EM wave-absorption and EM wave-reflection, and moreover upgraded the match level between magnetic loss and dielectric loss. By the judicious controlling of polymerization cycles and plating time, low-weight fabric-supported PANI/Co-Ni composites (with PANI and Co-Ni loading of 2.86 and 3.99 mg cm-2, respectively) were prepared, which displayed relatively high EMI SE (33.95–46.22 dB) when compared to their single peers (PANI-coated fabric and Co-Ni-coated fabric) or even the sum of them. Inspired by the so called “1+1>2” phenomenon, here we demonstrated that there was an EMI SE enhancement effect in this conductive polymer/metal system that may be associated with interphase chemical and/or physical interactions. Further analysis revealed that this EMI SE enhancement effect was evident under circumstances of relatively low metal content, and became weak with the increase of metal contents. The mechanisms involved were interpreted through a series of fundamental measurements, including Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), and vector network analysis (VNA). The linkage between PANI and Co-Ni coatings was in the form of Co-N/Ni-N, which mimics the atomic configuration occurring in cobalt porphyrins. The Co-N/Ni-N configuration strengthened the interphase adhesion and thus resulted in shielding fabrics with high durability for practical applications.
... Ranking together with noise, air and water pollution, EMI has been regarded as a novel public nuisance [2,3]. EM wave radiations from electronic instruments may cause mutual malfunction within the neighborhood as well as violate the intrinsic EM field of biological systems (such as adverse effects on the internal EM field of human being) [4,5]. Therefore, considerable efforts have been made in the past years to explore high-performance EMI shielding materials with desirable shielding effectiveness (SE) [6]. ...
The primary objective of this research work was to develop high-performance conductive fabrics with desired electromagnetic interference (EMI) shielding effectiveness (SE), excellent durability and improved corrosion resistance. Such conductive fabrics were fabricated by combining an ultra-low-cost electroless plating method with an alkoxy silane self-assembly technology, which involved successive steps of modification, activation, Co-Ni-P coating deposition and 3-aminopropyltrimethoxysilane (APTMS) thin coatings assembling. Malic acid (MA) was selected to modify the pristine Tencel (TS) substrates, and the probably interaction mechanism was investigated by FT-IR measurement. Co⁰⁰ and Ni⁰⁰ nanoparticles (NPs) were used as the activators to initiate electroless plating, respectively, and thereby two categories of Co-Ni-P coatings with different Co/Ni atomic ratio were obtained. Both of them presented compact morphologies and preferential (1 1 1) crystal orientation, which were validated by FE-SEM and XRD measurements. Owing to the lower square resistance and higher magnetic properties, the Co-Ni-P coated fabric activated by Co⁰⁰ activator showed a higher EMI SE (18.2-40.1 dB) at frequency of 30–1000 MHz. APTMS thin coatings were then assembled on the top of alloy coated fabrics to act as anti-corrosion barriers. Electrochemical polarization measurement in 3.5 wt.% NaCl solution showed that top-APTMS coated conductive fabric exhibited a higher corrosion resistance than the one in absence of APTMS assembly. Overall, the whole process of fabrication could be performed in several hours (or less) without any specialized equipment, which shows a great potential as EMI shielding fabrics in mass-production.
... As well known, the thickness of cellular membranes is slightly above 5 nm. For this level, reference [10] describes specific changes of electric field conditions. However, even more pronounced effects can be expected for the molecular level round a nanometer. ...
... In 1980, Cain developed, for the first time, a model to study neuronal firing activity under electromagnetic radiation based on the Hodgkin-Huxley neuron system [21], a model in which he treated electromagnetic radiation as a field. According to this idea, Apollonio et al. [22,23] proposed a complete quantitative evaluation of the effects of electromagnetic fields on neurons. However, a recent study [24] concluded that performing a comprehensive study of the non-thermal effects of electromagnetic radiation is only possible through a multi-scale methodology. ...
The electric activities of neurons serve as a foundation for normal brain functions. Electromagnetic radiation has a significant impact on neuronal activity in the brain, especially when cell phone is used extensively. To understand this mechanism, we developed a mathematical model aiming at describing the effect of electromagnetic radiation on neuronal firing activity by introducing an additional membrane current into the Hodgkin–Huxley neuron model. The results show that the neuronal firing activity of a single neuron can be suppressed by electromagnetic radiation. Besides, the spatiotemporal patterns of neuronal network are also suppressed from the stable propagating wave state to a homogeneous resting state. Our studies suggest that the electromagnetic radiation has a suppressive effect on neuronal firing activities, especially on the collective electric activities of neuronal network that is related to information processing.
... This coupling produces an induced electric field, an induced magnetic field and a significant and non-uniform local energy absorption for the typical frequencies (890-960 MHz; 1710-1880 MHz) used by the mobile telephone sector. [8,9] The physical coupling processes between EMF and biological systems are strictly related to the geometry of the human body, to tissue properties and to exposure conditions. In addition, the frequency of the EMF profoundly affects these coupling processes, so that the limit values are related to the frequency. ...
The electromagnetic field (EMF) levels generated by mobile telephone radio base stations (RBS) situated on rural-agricultural lands were assessed in order to evaluate the exposure of farm workers in the surrounding area. The expected EMF at various distances from a mobile telephone RBS was calculated using an ad hoc numerical forecast model. Subsequently, the electric fields around some RBS on agricultural lands were measured, in order to obtain a good approximation of the effective conditions at the investigated sites. The viability of this study was tested according to the Italian Regulations concerning general and occupational public exposure to time-varying EMFs. The calculated E-field values were obtained with the RBS working constantly at full power, but during the in situ measurements the actual power emitted by RBS antennas was lower than the maximum level, and the E-field values actually registered were much lower than the calculated values.
