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The application of wide band-gap power electronic devices brings more challenges to insulating packaging technology. Knowing the influence of applied voltage parameters on insulation performance is helpful to evaluate the insulation condition of electric power equipment. In this paper, the effect of repetitive square wave voltage duty cycle on the growth characteristics of electrical trees in epoxy resin was studied. The experimental results show that the square wave voltage duty cycle has a significant influence on treeing features. The electrical tree proportion initiation has shown a decreasing trend, and the shape of the electrical tree changes from pine-like to branch-like by increasing the duty cycles. The length and damaged area of electrical tree increased with the increase in the duty cycle up to 10% and then decrease by increasing the duty cycle higher than 30%. It indicates that a low duty cycle will enhance the electron injection and accumulate space charges and thus accelerate electrical tree development. Under short duty cycles, the electric field due to the shielding effect near the needle tip suppresses the electrical tree growth, which results in treeing growth stagnation. The obtained results are helpful to keep these parameters in mind during the design of epoxy-based insulation such high-voltage rotating machines and power electronic device packaging.

Tomato plants are among the most widely cultivated and economically important crops worldwide. Farmers’ major challenge when growing tomatoes is early blight disease caused by Alternaria solani, which results in significant yield losses. Silver nanoparticles (AgNPs) have gained popularity recently due to their potential antifungal activity. The present study investigated the potential of green synthesized silver nanoparticles (AgNPs) for enhancing the growth and yield of tomato plants and their resistance against early blight disease. AgNPs were synthesized using leaf extract of the neem tree. Tomato plants treated with AgNPs showed a significant increase in plant height (30%), number of leaves, fresh weight (45%), and dry weight (40%) compared to the control plants. Moreover, the AgNP–treated plants exhibited a significant reduction in disease severity index (DSI) (73%) and disease incidence (DI) (69%) compared to the control plants. Tomato plants treated with 5 and 10 ppm AgNPs reached their maximum levels of photosynthetic pigments and increased the accumulation of certain secondary metabolites compared to the control group. AgNP treatment improved stress tolerance in tomato plants as indicated by higher activities of antioxidant enzymes such as PO (60%), PPO (65%), PAL (65.5%), SOD (65.3%), CAT (53.8%), and APX (73%). These results suggest that using green synthesized AgNPs is a promising approach for enhancing the growth and yield of tomato plants and protecting them against early blight disease. Overall, the findings demonstrate the potential of nanotechnology-based solutions for sustainable agriculture and food security.

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The configuration is essential to diagnose the status of the grounding grid, but the orientation of the unknown grounding grid is ultimately required to diagnose its configuration explicitly. This paper presents a transient electromagnetic method (TEM) to determine grounding grid orientation without excavation. Unlike the existing pathological solutions, TEM does not enhance the surrounding electromagnetic environment. A secondary magnetic field as a consequence of induced eddy currents is subjected to inversion calculation. The orientation of the grounding grid is diagnosed from the equivalent resistivity distribution against the circle perimeter. High equivalent resistivity at a point on the circle implies the grounding grid conductor and vice versa. Furthermore, various mesh configurations including the presence of a diagonal branch and unequal mesh spacing are taken into account. Simulations are performed using COMSOL Multiphysics and MATLAB to verify the usefulness of the proposed method.

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An ultrasonication approach was adopted for Azadirachta indica driven bioconversion of silver salt into silver nanoparticle (AgNPs). These nanoparticles were coated over plasma functionalized cotton by using a pad dry cure technique. For pre‐coat surface functionalization, the cotton fabric was exposed to an open air single dielectric barrier discharge (DBD). The emission spectrum revealed that DBD consisted of NO, O3, O, O2+ , O+, OH−, N2 and N2+ species. The plasma treatment produced negative radicals on the surface and improved the adhesion of fabric for nanoparticles. The crystallographic analysis revealed cubical structure of nanoparticles with average size of 25 nm. The fabric got fully covered with AgNPs after five pad‐dry cycles. Nanoparticles together with neem extract promoted the antimicrobial activity of the coated fabric. The inhibition zone of the silver coated fabric against E.Coli strains increased from 6 mm to 14 mm. The conductivity of fabric after 3, 5 and 7 cycles remained 2.56× 10−2, 2.63× 10−2 and 2.67× 10−2 Siemens/cm, respectively. The coated fabric showed UV protection factor in the range of 210–269. The transmittance of UV−A radiations and UV−B radiations from the uncoated fabric was 19.27 % and 7.84 %, respectively, which reduced to 0.76 % and 0.24 % after 7 pad dry cycles.