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Electromagnetic interference (EMI) pollution has now become a subject of great concern with the rapid development of delicate electronic equipment in commercial, civil, and military operations. There has been a surge in pursuit of light-weight, adaptable, effective, and efficient EMI screening materials in recent years. The present article addresses a simple and sensitive approach to synthesize a core/shell carbon nanotube/MoS2 heterostructure supported on reduced graphene oxide (CNT/MoS2-rGO nanohybrid) as an efficient electromagnetic shielding material. The structural and morphological characteristics were accessed through X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and Raman spectroscopy, augmenting successful formation of the CNT/MoS2-rGO nanohybrid. The shielding performance of the as-synthesized samples has been accessed in a wide frequency range of 8–12 GHz. A CNT/MoS2-rGO nanohybrid demonstrates a better EMI shielding performance in comparison to MoS2 nanosheets and MoS2-rGO nanohybrid individually. The CNT/MoS2-rGO nanohybrid having a thickness ∼1 mm shows excellent total shielding effectiveness (SET) as high as 40 dB, whereas MoS2 and MoS2-rGO hybrid lags far, with the average value of SET as 7 and 28 dB, respectively. It also demonstrates that the nanohybrid CNT/MoS2-rGO shields the EM radiation by means of absorption through several functional defects and multiple interfaces present in the heterostructure. Herein, we envision that our results provide a simple and innovative approach to synthesize the light-weight CNT/MoS2-rGO nanohybrid having flexibility and high shielding efficiency and widen its practical applications in stealth technology.

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The present work reports nanocomposite of CdSe/V 2 O 5 core-shell quantum dots with reduced graphene oxide (rGO-V-CdSe), as an efficient lightweight electromagnetic wave shielding material, synthesized by a simplistic solvothermal approach. The as-synthesized nanocomposite was analyzed for its structural, compositional and morphological features by x-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy and x-ray photoelectron spectroscopy (XPS). The measurement of complex permittivity/permeability and total shielding efficiency of the as-synthesized samples has been done in a wide frequency range of 8-12 GHz (X-band). Compared to rGO and rGO-CdSe, rGO-V-CdSe nanocomposite exhibits significantly enhanced EMI shielding properties in terms of both dielectric loss and total shielding SE T . The high value of real permittivity (average ε′∼70) and the overall shielding effectiveness up to ∼38 dB have been recorded for rGO-V-CdSe nanocomposite. The studies also infer that the absorption contributes more in total shielding than reflection. The high value of dielectric loss and shielding effectiveness could also be attributed to the presence of various defects leading to dipolar and interfacial polarizations. The excellent EMI shielding properties of the nanocomposite in GHz frequency range (X-band) pave an intuitive way for fabricating a versatile EMI shielding nanocomposite material for applications.

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Cancer is the leading cause of death in recent centuries and microwave ablation (MWA) has been evolving to thermally treat cancerous tissue through cell necrosis and is also a promising substitute to radio frequency ablation. In this article, a novel normal-mode helical antenna based MWA probe is investigated for the effect on ablation diameter in the presence of five critical parameters. The antenna consists of an intertwining helix structure mounted on a very small ground plane. An external tapping is used to match the antenna impedance. In the proposed design at the center frequency, a reflection coefficient of more than 23 dB without insertion into the tissue model and a reflection coefficient of more than 14 dB with insertion into the tissue model have been observed at 5 GHz frequency. The gain and percentage bandwidth of the antenna is 0.6 dB and 10%, respectively. At 20 W power, a maximum ablation diameter of 32 mm (transversal-T) and 44 mm (axial-A) is reached within 5 min of application time at a distance of 30 mm from the probe. Further, the L27 Taguchi's orthogonal array has been employed to study the effect on ablation diameter by varying five thermo-electrical parameters. The outcome of Taguchi's analysis has been ranked according to the contribution of each parameter. Further, F-and p-value test has been employed using analysis of variance to study the significance of each parameter on ablation diameter.

Chemically prepared, 0.5% Fe(iii)-doped CdSe QDs exhibit superparamagnetism with weak ferromagnetic exchange interaction.

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