The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Peng Wang - One of the best experts on this subject based on the ideXlab platform.
-
A Study on the Space Charge Characteristics of AC Sliced XLPE Cables
IEEE Access, 2019Co-Authors: Chaofei Gao, Yifan Zhou, Wei Wang, Peng WangAbstract:Cross-linked polyethylene (XLPE) cables are widely used in power systems due to their excellent electrical and mechanical properties. Space Charge is an important factor in cable aging and breakdown. At present, XLPE cables in the power system are mainly ac XLPE cables, so it is necessary to study the space Charge Characteristics under ac voltage. In this paper, an electro-thermal aging platform for XLPE cable was built and a 10-kV cable was aged. XLPE slices were obtained from the aging cable and ac space Charge experiments were carried out on the XLPE slices at different stages of aging. The trap energy levels were calculated and the effects of different electric fields on the ac space Charge Characteristics were compared. The experimental results show that the trap energy level increases with the aging process and the non-averaged electric field is a necessary condition for Charge migration.
-
removal of antibiotics using polyethylenimine cross linked nanofiltration membranes relating membrane performance to surface Charge Characteristics
Chemical Engineering Journal, 2018Co-Authors: Shanshan Zhao, Yaxuan Yao, Weihua Zheng, James Economy, Peng WangAbstract:Abstract In this study, surface positive Charge intensity of a polyethylenimine (PEI) modified nanofiltration (NF) membrane was characterized by adsorption of counter ions WO42− on the membrane surface at pHs 2–10 followed by quantitative analysis using X-ray photoelectron spectrometry (XPS). Retentions of NaCl and two representative antibiotics (cefadroxil and enrofloxacin) by this membrane were systematically evaluated at pHs 2–10. It was found that the PEI (25,000 g·mol−1) modified NF membrane exhibited positive Charge and the Charge intensity was strong, moderate and weak in the pH range of
Chaofei Gao - One of the best experts on this subject based on the ideXlab platform.
-
A Study on the Space Charge Characteristics of AC Sliced XLPE Cables
IEEE Access, 2019Co-Authors: Chaofei Gao, Yifan Zhou, Wei Wang, Peng WangAbstract:Cross-linked polyethylene (XLPE) cables are widely used in power systems due to their excellent electrical and mechanical properties. Space Charge is an important factor in cable aging and breakdown. At present, XLPE cables in the power system are mainly ac XLPE cables, so it is necessary to study the space Charge Characteristics under ac voltage. In this paper, an electro-thermal aging platform for XLPE cable was built and a 10-kV cable was aged. XLPE slices were obtained from the aging cable and ac space Charge experiments were carried out on the XLPE slices at different stages of aging. The trap energy levels were calculated and the effects of different electric fields on the ac space Charge Characteristics were compared. The experimental results show that the trap energy level increases with the aging process and the non-averaged electric field is a necessary condition for Charge migration.
Hideaki Fujitani - One of the best experts on this subject based on the ideXlab platform.
-
Charge Characteristics and related dispersion/flocculation behavior of soil colloids as the cause of turbidity
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2005Co-Authors: Katsuhiko Itami, Hideaki FujitaniAbstract:Abstract Dispersion/flocculation (D/F) behavior of soil colloids is closely related to numerous environmental issues and regulated by the Charge Characteristics of the colloids. The Charge Characteristics of five clays commonly distributed in Japan (montmorillonite, sericite, kaolinite, halloysite and allophane) were determined by the modified ion adsorption method using caesium as an index cation and compared with the D/F behavior under the similar conditions. The flocculation effect of Cs on negatively Charged clays enabled accurate Charge analysis in the high pH and low electrolyte concentration region where measurement had been difficult by conventional methods due to clay dispersion. The dispersion ratio of montmorillonite was evenly high in all pH regions reflecting its large permanent Charge. The pH dependence of sericite Charge was rather variable than permanent. The dispersion ratio of sericite was increased abruptly above pH 6.5. The pH dependence of kaolinite negative Charge was small, indicating the predominance of permanent Charge. Both negative and positive Charges were detected from halloysite in large pH regions. The dispersibility of kaolinite and halloysite was increased above pH 7. To explain the observed discrepancy between the Charge Characteristics and the D/F behavior, the significant role of edge surfaces in flocculation was emphasized for sericite, kaolinite and halloysite. In case of halloysite, the reverse imogolite structure curling with the Al-octahedral layers inside was proposed to account for the constant negative Charge detected in all pH regions. Allophane showed the Charge Characteristics typical of variable Charge minerals and dispersed in both acid and alkali regions. The difference between the Charge Characteristics and the dispersibility of allophane was attributed to the heterogeneity of its Charge. From the aspect of environmental conservation, keeping the suspension pH below 6–7 so as to prevent edge surfaces from dissociating is likely to be primarily important to control clay dispersion depending on the clay mineralogy. By combining the information derived from this Cs adsorption method with the proper land management, more effective techniques to reduce soil losses and water pollution will be established according to field conditions.
V Dudarchik - One of the best experts on this subject based on the ideXlab platform.
-
Charge Characteristics of humic and fulvic acids comparative analysis by colloid titration and potentiometric titration with continuous pk distribution function model
Chemosphere, 2008Co-Authors: S Bratskaya, A Golikov, T Lutsenko, O Nesterova, V DudarchikAbstract:Charge Characteristics of humic and fulvic acids of a different origin (inshore soils, peat, marine sediments, and soil (lysimetric) waters) were evaluated by means of two alternative methods – colloid titration and potentiometric titration. In order to elucidate possible limitations of the colloid titration as an express method of analysis of low content of humic substances we monitored changes in acid–base properties and Charge densities of humic substances with soil depth, fractionation, and origin. We have shown that both factors - strength of acidic groups and molecular weight distribution in humic and fulvic acids – can affect the reliability of colloid titration. Due to deviations from 1:1 stoichiometry in interactions of humic substances with polymeric cationic titrant, the colloid titration can underestimate total acidity (Charge density) of humic substances with domination of weak acidic functional groups (pK > 6) and high content of the fractions with molecular weight below 1 kDa.
Xingming Bian - One of the best experts on this subject based on the ideXlab platform.
-
Research on surface Charge Characteristics of insulating film in ion-flow field
2017 IEEE International Symposium on Electromagnetic Compatibility & Signal Power Integrity (EMCSI), 2017Co-Authors: Qinyuan Li, Bo Chen, Donglai Wang, Tiebing Lu, Xingming BianAbstract:Surface Charges accumulated on insulating film will change the electric field around the insulating film, and the surface Charge distribution has direct relationship with the electric field around. In order to investigate the surface Charge Characteristics of insulating film in ion-flow field, an experimental platform was designed, which contained a Charge generating apparatus, an electrometer and a control apparatus. With the Charge generating apparatus, the Charges accumulated on the surface of insulating film, the electric field and the ion-flow around the insulating film could be controlled. The surface potentials of insulating film were measured by a vibrated capacitor electrometer, and the surface Charge distributions of insulating film were obtained by the surface Charge method. In this paper, the surface Charge distribution Characteristics of insulating film under different conditions are compared, and the factors that influence the surface Charge Characteristics are discussed.