Transformer oil-based nanofluids with TiO2 semiconductive nanoparticles exhibit substantially higher AC and positive impulse breakdown voltage levels than that of pure transformer oils. Thermally stimulated current method (TSC) pulse electroacoustic technique (PEA) have been used to measure charge trap transportation characteristics oils nanofluids. It is found electron shallow density decay rate are greatly increased in nanofluids, i.e., fast electrons may be converted slow by trapping...

Surface creeping discharge at solid-liquid interface is regarded as one of the reasons for oil-immersed transformers failure. In order to restrain surface discharge, we investigated effects TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanoparticles on and flashover characteristics oil/pressboard under AC impulse voltages. Partial tests (OPs) nanofluid/- pressboard (NPs) were carried out. The results show that can improve both...

Recent experiments have shown that some nanoparticles can influence the breakdown strength of transformer oil under lightning impulse voltage. To reveal working mechanism, this paper presents an experimental study on effect TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and prebreakdown streamer propagation process in oil-based nanofluid both positive negative The test results verify modification has a distinct polar effect: voltage...

TiO2 nanoparticle with good dispersibility and stability in transformer oil was prepared used to modify insulating property of aged oil. It found that space charge decay rate the modified can be significantly enhanced 1.57 times at first 8 s after polarization voltage removed. The results trap characteristics reveal modification not only greatly lower shallow energy level but also increase density, resulting improved transportation via trapping de-trapping process shallower traps.

The flashover phenomenon of the insulator is main cause for insulating failure GIS/GIL, and one most critical impacting factors accumulation surface charge. common methods to restrain charge are reviewed in this paper. Through reasonable comparison analysis these methods, nano-coatings were selected as a way accumulation. Based on this, six nano-coated epoxy resin samples with different concentrations P25-TiO2 nanoparticles produced. A high precision 3D measurement system was developed paper...

Background . Endothelial barrier disruption of human pulmonary vascular endothelial cells (HPVECs) is an important pathogenic factor for acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Mesenchymal stem cells‐exosome (MSCs‐Exo) represents ideal carrier cell‐free therapy. The therapeutic implication and underlying mechanism placental MSCs‐Exo (HPMSCs‐Exo) in ALI/ARDS need to be further explored. Materials Methods HPMSCs‐Exo was extracted from HPMSCs characterized. Then, the...

The adhesion of ice to high -voltage overhead transmission lines should be small ensure ease shedding under external forces. In this work, we studied the influence microstructure superhydrophobic surfaces on strength at a working temperature −6 °C. Compared bare aluminum surface, did decrease strength. with larger number micro-holes produced lowest adhesion; its was ∼163.8 times lower than that for samples. Furthermore, such had water contact angles 150° and sliding less 8.2° even low values...

Nanotechnology provides a new way to improve the insulating properties of traditional dielectric materials. In this study, three types mineral oil based nanofluids were prepared by suspending Fe3O4, TiO2 and Al2O3 nanoparticles all which surface modified oleic acid. The inception voltage, stopping length propagating velocity streamers in under positive lightning impulse voltage experimentally studied. It is found that can restrain initiation propagation processes transformer depending on...

Transformer pressboard impregnated in mineral oil modified by nanoparticles (nanofluid) exhibits substantially higher AC and DC breakdown voltage than that of the pure oil-impregnated (OP). Charge transport decay characteristics both pressboards were measured pulse electroacoustic technique. It reveals nanofluid-impregnated (NP) has a more uniform internal electric field charge rate compared to OP, which is caused an increase shallow trap density NP related difference structures, based on...

In order to improve the electrical characteristics of transformer oil-impregnated pressboard, oil-based nanofluids were used impregnate pressboards. It is found that nanofluid-impregnated pressboard (NP) exhibits substantially higher AC and DC breakdown voltage than pure (OP). Pulse electroacoustic measurement (PEA) was carried out study difference space charge distribution decay characteristic in OP NP. has demonstrated NP a more uniform internal electric field, which caused by transport...

Nanoparticles currently in use are challenged further improving the dielectric strength of insulating oil. There is a great need for new type nanoparticle to promote application oil-based nanofluids electric industries. This paper experimentally investigates effect morphology on pre-breakdown and breakdown properties nanofluids. The positive impulse voltage oil can be significantly increased by up 55.5% presence TiO2 nanorods, 1.23 times that nanospheres. Pre-breakdown streamer propagation...

This paper presents experimental research on creeping discharge characteristics of TiO2 nanofluid-impregnated pressboards (NPs) under sustained ac voltage. It was found that NPs possess higher resistance to than pure oil-impregnated pressboard. The results permittivity and surface charge accumulation decay reveal the modification nanoparticles can not only make electric field more uniformly distributed at interface nanofluid/pressboard due a better matching in but also significantly increase...

Background: Although obesity may affect reproductive functions, the molecular mechanisms of apoptosis-related biomarkers remain uncertain. Objective: To examine effects body mass index on sperm quality and factors in seminal plasma men. Methods: Data for 54 subfertile men were collected at our medical center. The divided into normal weight, overweight, obese groups based their (BMI). Sperm DNA fragmentation (sperm chromatin structure analysis), apoptosis (annexin V), (antibody array assay)...

Small-diameter ZnO nanorods (∼10nm) with lengths of 80–100nm were synthesized by a simple solution route at low temperature (61.2°C). X-ray diffraction and high-resolution transmission electron microscopy analyses confirmed that the are hexagonal single crystals growth direction along [001]. Room photoluminescence (PL) measurement showed strong ultraviolet (UV) emission peak 382nm weak deep level emission. Quantum confinement effect in was clearly revealed PL. The complex origin UV has been...