Investigation of XLPE Cable Insulation Using Electrical, Thermal and Mechanical Properties, and Aging Level Adopting Machine Learning Techniques

Hydrothermal and chemical aging tests on a 230 kV cross-linked polyethylene (XLPE) insulation cable were carried out in the present study to evaluate the degradation and aging levels qualitatively. The samples were subjected to water aging at a temperature of 80 °C, and in an aqueous ionic solution of CuSO4 at room temperature. The diffusion coefficient results indicated that the ion migration was not at the same rate in the aging conditions. The diffusion coefficient–D–of the sample immersed in an aqueous CuSO4 solution was lower than the hydrothermally aged specimens. The hydrophobicity of aged specimens decreased considerably compared to unaged samples. The distribution of trapped charges was quantitatively characterized. The presence of shallow trap energy states were observed in unaged XLPE, whereas the deep trap sites were noticed in aged specimens. In addition, the charge trap characteristics were different for positive and negative charge deposition. Various material characterization techniques, viz. dynamic mechanical analysis (DMA), tensile, contact angle, and LIBS, were further employed on the aged and virgin specimens. The tensile behavior of the hydrothermally aged specimen was degraded due to the oxidised regions, which had formed a weak spot against the mechanical stress. Reduced glass transition temperature and increased loss tangent measurements were noticed for aged specimens over their unaged counterparts. Machine learning techniques, such as the principal component analysis (PCA) and the artificial neural network (ANN) analysis, were performed on LIBS spectral data of the samples to classify the aging mechanisms qualitatively

Investigation of XLPE Cable Insulation Using Electrical, Thermal and Mechanical Properties, and Aging Level Adopting Machine Learning Techniques

Hydrothermal and chemical aging tests on a 230 kV cross-linked polyethylene (XLPE) insulation cable were carried out in the present study to evaluate the degradation and aging levels qualitatively. The samples were subjected to water aging at a temperature of 80 °C, and in an aqueous ionic solution of CuSO4 at room temperature. The diffusion coefficient results indicated that the ion migration was not at the same rate in the aging conditions. The diffusion coefficient–D–of the sample immersed in an aqueous CuSO4 solution was lower than the hydrothermally aged specimens. The hydrophobicity of aged specimens decreased considerably compared to unaged samples. The distribution of trapped charges was quantitatively characterized. The presence of shallow trap energy states were observed in unaged XLPE, whereas the deep trap sites were noticed in aged specimens. In addition, the charge trap characteristics were different for positive and negative charge deposition. Various material characterization techniques, viz. dynamic mechanical analysis (DMA), tensile, contact angle, and LIBS, were further employed on the aged and virgin specimens. The tensile behavior of the hydrothermally aged specimen was degraded due to the oxidised regions, which had formed a weak spot against the mechanical stress. Reduced glass transition temperature and increased loss tangent measurements were noticed for aged specimens over their unaged counterparts. Machine learning techniques, such as the principal component analysis (PCA) and the artificial neural network (ANN) analysis, were performed on LIBS spectral data of the samples to classify the aging mechanisms qualitatively

Inhibition of Proliferation of HeLa Cells by Pulsed Electric Field Treated Mentha piperita (Mint) Extract

In this research, the effectiveness of Mentha piperita (M. piperita) leaf extract against HeLa, a human cervical cancer cell line was investigated. We assessed the phytochemicals present in this extract by phytochemical screening tests and analysed the free radical scavenging activity and anticarcinogenic activity using without Pulsed Electric Field (PEF). The methanolic M. piperita extract was prepared by the Soxhlet extraction method, and was treated by PEF using 50 unipolar pulses, 10 kV/cm, 100 mu s and the effect of PEF on the antioxidant and anticarcinogenic activities of M. piperita extract was investigated and compared to Soxhlet extraction (70 degrees C for 8 h). The preliminary phytochemical analysis indicated the presence of phenols, tannins, flavonoids, alkaloids, steroids, reducing sugars and the absence of saponins, anthocyanins, catechins, terpenoids, carotenoids, and anthraquinones. The free radical scavenging activity of both PEF treated and untreated extract was determined by 2,2-Diphenyl-1-Picrylhydrazyl assay. Compared to untreated extract, 7.36% greater antioxidant activity was obtained from PEF treatment. The anticarcinogenic activity of both extracts were determined by MTT proliferation assay against Hela cells. The results indicated a viability of 34.77% for the PEF treated M. piperita extract (compared to 41.2% for the Soxhlet extract and 100% for the control). This indicates that the PEF-treated M. piperita extract showed higher antioxidant activity and anticarcinogenic activity than the other extracts. Hence, the application of PEF may be appropriate to achieve antioxidant rich extract and maximal cell death could be achieved with PEF treatment thereby, reducing the concentration of extract required for treating cancer