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In this work, we show the probability density functions (PDFs) and cumulative density functions (CDFs) of the nonnormalized field components and the associated powers received inside coupled reverberation chambers (CRCs), considering two canonical cases of single electrically small coupling apertures (ESCAs). These two cases involve one-dimensional (1D) and two-dimensional (2D) single electrically small CAs, respectively. We achieve normalized statistics from the nonnormalized ones for both field components and associated powers. We show that the comparison of the mean square values (MSVs) of the nonnormalized PDFs of the field components to the mean values (MVs) of the related nonnormalized PDFs of the powers is a proper method to corroborate the accuracy of the same achieved theoretical distributions, when they are achieved in an independent way. The achieved theoretical results are also validated by measurements. Moreover, for the sake of completeness and rigor of published results, we show two useful cases of the results from the measurements using two electrically large CAs.

Among public facilities, facilities belonging to Multi-Group (I) include high-rise buildings, tunnels, and subway stations, and the location of Shelter in Place (SIP) is an important factor in the safety of citizens. However, subway evacuation maps usually induce evacuation to ground level or the tunnel of a subway platform without considering the location of SIP. In other words, since the location of the SIP is not determined, conditions, such as ventilation, air conditioning facilities, and structural durability required for the SIP cannot be satisfied. It is difficult to suggest the location of SIP because the domestic standards limit only the time it takes to move from the outside to the facility designated as SIP during an emergency evacuation. Therefore, in this study, when there is a situation of emergency evacuation in the subway, the total allowed time to evacuate to SIP is limited to 6 min. We designate a space that can accommodate the number of evacuees at the location and compare and analyze the results of the evacuation simulation using six scenarios. Additionally, suggestions are made for improvement methods relating to evacuation as well as the proposal of reinforcement methods through an experiment to satisfy the structural requirements of SIP in subway stations.

Lightweight materials, such as polymers and composites, are increasingly used in the automotive and aerospace industries. Recently, there has been an increase in the use of these materials, especially in electric vehicles. However, these materials cannot shield sensitive electronics from electromagnetic interference (EMI). The current work investigates the EMI performance of these lightweight materials using an experimental setup based on the ASTM D4935-99 standard and EMI simulation using the ANSYS HFSS. This work studies how metal coating from zinc and aluminum bronze can improve the shielding performance of polymer-based materials, such as polyphenylene sulfide (PPS), polyetheretherketone (PEEK), and polyphthalamide (PPA). Based on the findings of this study, a thin coating (50 μm) of Zn on the surface of PPS and a thin coating of 5 μm and 10 μm of Al-Bronze, respectively, on the surface of PEEK and PPA have indicated an increase in the shielding effectiveness (SE) when subjected to EMI. The shielding effectiveness significantly increased from 7 dB for the uncoated polymer to approximately 40 dB at low frequencies and up to approximately 60 dB at high frequencies for coated polymers. Finally, various approaches are recommended for improving the SE of polymeric materials under the influence of EMI.

Electromagnetic interference (EMI) is one of the biggest challenges faced during the production of any electronic device. The effect on the performance of the instrument due to these inevitable interferences must be carefully measured to understand and quantify the electromagnetic compatibility (EMC) of the instrument under test. If the EMI profile of the system does not meet the accepted standards, then it becomes necessary to take measures to reduce the influence of these unwanted interferences so that the equipment can be used in the real world. Unfortunately, research and studies on EMI and EMC have not received their due attention from the scientific community. Moreover, the literature available for this area of research is scattered where different sources provide information on one or more (but not all) aspects of EMI/EMC while ignoring the others. With the objective of encompassing this extremely significant area of research in its entirety, this review presents both EMI measurement techniques and EMI reduction techniques in detail. EMI measurement techniques are presented under two sections that deal with emission testing and immunity testing, respectively. Herein, EMI reduction techniques are presented under four sections, where electromagnetic shielding has been given special attention under which various methods used by the scientific community to measure the shielding effectiveness of a material or microwave absorber and its application in EMI reduction are illustrated. This is followed by EMI filters, circuit topology modification and spread spectrum. This review can help students and young scientists in this area to get an idea of the ways to conduct EMI tests as well as the ways that can be employed to reduce the EMI of the system, depending on the application.

For Pb-free 35B 2 O 3 ‒35Bi 2 O 3 ‒(30– x )TeO 2 ‒( x )BaO ( x  = 5, 10, 15, 20, and 25 mol%) and (90– x )TeO 2 ‒10Bi 2 O 3 ‒( x )BaO ( x  = 10, 15, and 20 mol%) glass systems, gamma and neutron (both fast and thermal neutron) radiation shielding features were examined and compared. Within 0.015–15 MeV photon energy, mass attenuation coefficients ( μ / ρ ), for all samples, which have been assessed using WinXCOM program are in fair agreement with deduced MCNP5 simulation code μ/ρ results. For all selected samples, at the lowest energy, μ / ρ has bigger values whereas at higher energy regions possess lower values. Furthermore, by employing μ / ρ values, effective atomic number ( Z eff ), effective electron density ( N eff ), half-value layer (HVL), tenth-value layer (TVL), and mean free path (MFP) are figured out for both glass systems. For studied samples, with the gradual replacement of TeO 2 content with BaO, the derived values of Z eff , HVL, TVL, and MFP revealed improved γ-ray shielding potentiality. Besides, within photon energy range of 0.015–15 MeV, exposure build-up factors (EBFs) and energy absorption build-up factors (EABFs) were estimated for all samples by utilizing G‒P fitting method as a function of different penetration depths (0.5, 1, 2, 3, 4, 5, 6, 7, 8, 10, 15, 20, 25, 30, 35, and 40 mfp). The 35B 2 O 3 –35Bi 2 O 3 –5TeO 2 –25BaO (mol%) glass relatively larger μ / ρ and Z eff values, lower HVL, TVL, and MFP values, and minimal EBF and EABF values confirm its superior γ-ray attenuation competence among all samples. Additionally, in comparison, HVL and MFP values of 35B 2 O 3 –35Bi 2 O 3 –5TeO 2 –25BaO (mol%) sample are lower than the respective values of some commercial γ-ray shielding glasses and different types of standard concretes, signifying its better shielding features than them. Moreover, macroscopic removal cross-section for fast neutrons ( Σ R ), coherent scattering cross-section ( σ cs ), incoherent scattering cross-section (σ ics ), absorption cross-section ( σ A ), and total cross-section ( σ T ) for thermal neutrons absorption were derived for both glass systems. Among all selected glasses, 35B 2 O 3 –35Bi 2 O 3 –5TeO 2 –25BaO (mol%) sample possesses relatively higher Σ R (0.106 cm −1 ) and ‘ σ T ’ (8.809 cm −1 at 0.0253 eV neutron energy) values for fast and thermal neutrons attenuation, respectively, demonstrating its favorable absorption capability for neutrons.

Testing the shielding effectiveness of materials is a key step for many applications, from the industrial to the biomedical field. This task is very relevant for high-sensitivity sensors, whose performance can be greatly affected by electromagnetic fields. However, the available testing procedures often require expensive, bulky, and heavy measurement chambers. In this paper, a cost-effective and reliable measurement procedure for testing the shielding effectiveness of materials is proposed. It exploits a lab-scale anechoic shielded chamber, which is lightweight, compact, and cost-effective if compared to the available commercial solutions. The measurement procedure employs a vector network analyzer to allow an accurate and fast characterization setup. The chamber realization phases and the measurement procedure are described. The shielding capability of the chamber is measured up to 26 GHz, whereas the performance of commercial shielding coatings is tested to demonstrate the measurement’s effectiveness.

With the increase wireless communications, many wireless devices and equipment have been invented for special applications, resulting in mutual interference that might destroy the systems or distort signal in-transmission. One of the effective methods to reduce or eliminate interference is to devise a shielding to block the unwanted interference in between the approaching systems, circuits, devices, etc. Thus, shielding and estimation of its effectiveness are very important in order to protect the information devices from potential interference and to improve the performance of information equipment. In this survey, we present the recent developments of the shielding and shielding effectiveness techniques and methods, and give a design for an electromagnetic shielding structure.

This paper presents a novel polarization-insensitive dual-band frequency-selective surface (FSS)-based electromagnetic shield. The miniaturized FSS unit cell consists of a modified Jerusalem crossed loop and a corner-modified square loop. These FSS elements are arranged in a co-planner configuration over a single-layer Rogers 5880 substrate and simultaneously offer effective shielding in the X- and Ku-bands. Moreover, the FSS manifests polarization-independent and angularly stable band-reject filter characteristics over various oblique angles of incidence for both the TE and TM polarizations with virtuous attenuation at both resonances. In addition, the FSS structure is modelled into an equivalent lumped circuit to better analyze the phenomenon of EM wave suppression. A finite prototype of FSS is fabricated and tested. The simulated and measured results are in good agreement, thus making it a potential candidate for RF shielding/isolation applications.

Conductive filler loading in the polymer matrix is a common practice to transform insulative polymers to conducting composites. In case of textiles, the highly promising approach has been coined by virtue of fabricating with conductive adhesive homogeneous coating. The present fabrication approach has been developed by two-stage wet mixing technique including synthesis of silver nanoparticles decorated graphene sheets (rGO/Ag), followed by the preparation of conducting coating by non-ionic polymer adhesive. The novelty lies in the choice of conductive material and coating strategy to make lightweight and flexible smart electronic fabric. In order to protect the radiation pollution from the immense use of electronic devices and gadgets, the coated textiles can be an excellent replacement of other commercially available polymer coatings. The electromagnetic interference (EMI) shielding effectiveness of the prepared coated textile was 27.36 dB in the X band (8.2–12.4 GHz). Besides this it is worth mentioning that our developed coated fabric was enough conductive to light up a series of 57 LEDs with high intensity. Last but not the least this work also reconnoitres bactericidal feature against E. coli.

With advancements in the automated industry, electromagnetic inferences (EMI) have been increasing over time, causing major distress among the end-users and affecting electronic appliances. The issue is not new and major work has been done, but unfortunately, the issue has not been fully eliminated. Therefore, this review intends to evaluate the previous carried-out studies on electromagnetic shielding materials with the combination of Graphene@Iron, Graphene@Polymer, Iron@Polymer and Graphene@Iron@Polymer composites in X-band frequency range and above to deal with EMI. VOSviewer was also used to perform the keyword analysis which shows how the studies are interconnected. Based on the carried-out review it was observed that the most preferable materials to deal with EMI are polymer-based composites which showed remarkable results. It is because the polymers are flexible and provide better bonding with other materials. Polydimethylsiloxane (PDMS), polyaniline (PANI), polymethyl methacrylate (PMMA) and polyvinylidene fluoride (PVDF) are effective in the X-band frequency range, and PDMS, epoxy, PVDF and PANI provide good shielding effectiveness above the X-band frequency range. However, still, many new combinations need to be examined as mostly the shielding effectiveness was achieved within the X-band frequency range where much work is required in the higher frequency range.