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Room temperature vulcanizing (RTV) silicone rubber coating has excellent leakage current suppression characteristics. It is used extensively on porcelain and glass insulators in pollution prone areas as an anti-pollution measure. A pollution aging chamber has been fabricated and an on line 4 -channel personal computer (PC) based data acquisition system has been developed to conduct tests on RTV coated porcelain samples. A study of the dependence of the leakage current and the charge on the flow rate, conductivity and pressure of the solution forming the fog is reported. It was observed that a higher charge and a higher average leakage current were obtained at a higher flow rate and a higher conductivity. The results with coated HV insulators are consistent with those published in the literature with RTV coated fiber glass reinforced plastic (FRP) rods.

Abstract. The present investigation was conducted to understand the influence of long-term exposure of rats to extremely low frequency magnetic fields (ELF-MF), focusing on oxidative stress (OS) on different regions of rat's brain. Male Wistar rats (21-day-old) were exposed to ELF-MF (50 Hz; 50 and 100 µT) for 90 days continuously; hippocampal, cerebellar and cortical regions from rats were analyzed for (i) reactive oxygen species (ROS), (ii) metabolites indicative of OS and (iii) antioxidant enzymes. In comparison to control group rats, the rats that were continuously exposed to ELF-MF caused OS and altered glutathione (GSH/GSSG) levels in dose-dependent manner in all the regions of the brain. Accumulation of ROS, lipid peroxidation end products and activity of superoxide dismutase in different regions was in the descending order of cerebellum > hippocampus > cortex. Decrement in GSH/GSSG levels and increment in glutathione peroxidase activity were in the descending order of hippocampus > cerebellum > cortex. The continuous exposure to ELF-MF caused OS in all the examined regions of brain more significantly at 100 µT than at 50 µT. Varied influences observed in different regions of the brain, as documented in this study, may contribute to altered metabolic patterns in its related regions of the central nervous system, leading to aberrant neuronal functions.

Background: There are several reports that indicate a linkage between exposure to power frequency (50 -60 Hz) magnetic fields with abnormalities in the early embryonic development of the chicken. The present study was designed to understand whether power frequency electromagnetic fields could act as an environmental insult and invoke any neurochemical or toxicological changes in developing chick embryo model.

The cell viability and DNA damage in unstimulated sheep primary lymphocytes subjected to different extremely low electromagnetic field intensities (5, 50 and 100 µT; 50 Hz) were studied with special emphasis on apoptosis. Sheep primary lymphocytes cultured in RPMI, supplemented with 10% FBS in the absence of mitogens, were exposed till 16 h. The cell viability assessment by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay showed a dose dependent enhancement of viability at 16 h. Further, quantitative DNA laddering and flow cytometric analysis showed a significant decrease in apoptosis of the cells subjected to 100 (p<0.01) and 50 µT (p<0.05) for 16 h as compared to control group. There was a statistically significant decrease (p<0.01) in the specific activity of caspase 9 at 100 µT in cells exposed for 16 h. However, no enhancement of DNA damage was observed at 5, 50 and 100 µT as evidenced by comet assay. Comet assay also confirmed the decreased cell death of exposed cells (100 µT). Experimental data suggests decreased apoptosis at 100 µT (50 Hz), possibly by the suppression of caspase 9 activity leading to the enhanced cell viability. Effect of ELF-EMF on primary lymphocytesBioDiscovery | www.biodiscoveryjournal.co.uk

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