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Nanoparticles have exhibited great potential in improving insulating property of liquid and solid dielectrics. To explore their modification mechanism on transformer oil-impregnated pressboards, TiO2 nanoparticles with different diameters of 5nm, 10nm, and 15nm were synthesized and used to prepare transformer oil-based nanofluids. The creeping flashover characteristics of both pure oil-impregnated paperboards (OPs) and nanofluid-impregnated pressboards (NPs) were examined under lightning impulse and AC voltages. It was found that the creeping flashover property of NPs is significantly improved with the decreasing of nanoparticle size. Especially, it is enhanced by 2.44 times under positive lighting impulse as nanoparticle size reduced from 15 nm to 5 nm. The results of space charge decay and trap characteristics reveal the decrease of nanoparticle size can lower trap depth and greatly enhance the space charge dissipation rate, leading to more uniform electric field distribution at the interface between nanofluid and pressboards and higher creeping flashover property. [ABSTRACT FROM AUTHOR]

Recent studies have found that the surface flashover strength of oil-impregnated insulation paper can be improved by the modification of nanoparticles. To reveal the working mechanism, this paper presents an experimental study on the effects of TiO2 nanoparticles on streamer propagation process at the surface of oil-based nanofluid-impregnated insulation paper under lightning impulse voltage. The results show that the surface flashover voltage of nanofluid-impregnated insulation paper is significantly increased by 34.6%. Streamer characteristics including shape and length at the surface of oil-impregnated insulation paper were investigated using the schlieren technique. It is indicated that streamer characteristics are dramatically changed by the addition of TiO2 nanoparticles. For nanofluid-impregnated insulation paper, streamers with more but much shorter branches tend to develop into adjacent nanofluid rather than clinging to the paper compared to that for pure oil-impregnated paper. The reason responsible for the shape dissimilarity lies in the change of electrical force due to the permittivity difference between oil and paper. Furthermore, more shallow traps introduced by nanoparticles contribute to the faster surface charge dissipation of nanofluid-impregnated paper, reducing the charge accumulation at the streamer head and suppressing the electric field distortion. Thus, it is hard for streamers to develop at the surface of nanofluid-impregnated paper, resulting in an increase of surface flashover strength. [ABSTRACT FROM AUTHOR]

This article sheds light on the nature, forms and outcomes of China’s diplomacy over transboundary water resources. Water diplomacy bears unique and complex features and approaches for forming cooperative partnerships in the contextual settings where it is developed. By surveying the development and effectiveness of water diplomacy, it argues that water diplomacy is unlikely to succeed in conditions where power relations are unstable, or among countries experiencing low economic growth. The Ganges–Brahmaputra–Meghna (GBM) River Basin is examined as a case study. It is noticed that distrust has resulted in the development of complicated dynamics in Sino–Indian water disputes. China has displayed vested interests in its water diplomacy. Not only is the Chinese government seeking economic profits such as through the generation of hydropower, it also seeks to protect its strategic interests through the domination of hydrological data and water policy information. Such strategic interests may obstruct foreign relations unless substantial cooperative water sharing initiatives are implemented. As India has displayed varying interests in the diplomatic process, the outcomes are proving limited and risky. In the absence of substantive collaborative initiatives over water management, the mismatched interests over the GBM Basin have the potential to further strain the already unstable relations between two of the major powers in South Asia. [ABSTRACT FROM PUBLISHER]