Thermal ageing of cross-linked polyethylene (XLPE) cable insulation is an important issue threatening the safe operation of power cables. In this paper, thermal ageing of XLPE was carried out at 160 °C in air for 240 h. The influence of oxygen diffusion on thermal ageing of XLPE was investigated by Ultraviolet-visible spectrophotometer (UV-Vis), tensile testing, and Fourier transformed infrared spectroscopy (FTIR). It was observed that the degradation degree not only depended on ageing time but also on sample positions. The thermally aged samples were more oxidized in the surface region, presented a darker color, more carbon atoms appeared in the conjugate cluster, had smaller elongation at break and tensile strength, and a larger carbonyl index. As ageing time increased, the non-uniform oxidation of the XLPE samples became more prominent. The degree of non-uniform oxidation caused by oxygen diffusion was quantitatively studied by first order oxidation kinetic. The calculated results demonstrated that carbonyl index measured by FTIR was more sensitive to non-uniform oxidation with a shape parameter in the range of 1-2. The result shown in this paper is helpful for interpreting and predicting the non-uniform ageing behavior of high voltage XLPE cables.
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http://dx.doi.org/10.3390/ma13092056 | DOI Listing |
Geroscience
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National Institute On Aging, Bethesda, MD, USA.
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EPFL: Ecole Polytechnique Federale de Lausanne, Department of Chemistry, Rue de Industries 17, 1050, Sion, SWITZERLAND.
Carbon perovskite solar cells (C-PSCs) represent a promising photovoltaic technology that addresses the long-term operating stability needed to compete with commercial Si solar cells. However, the poor interface contacts between the carbon electrode and the perovskite result in a gap between C-PSC's performances and state-of-the-art PSCs based on metallic back electrodes. In this work, Cu (II) phthalocyanine (CuPc) was rediscovered as an effective hole-transporting material (HTM) to be coupled with carbon electrodes.
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Department of Internal Medicine-Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, United States.
Gut dysbiosis contributes to multiple pathologies, yet the mechanisms of the gut microbiota-mediated influence on systemic and distant responses remain largely elusive. This study aimed to identify the role of nanosized bacterial extracellular vesicles (bEVs) in mediating allodynia, i.e.
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January 2025
Centre for Tropicalization (CENTROP), Defence Research Institute, Universiti Pertahanan Nasional Malaysia, Kem Sungai Besi, 57000, Kuala Lumpur, Malaysia.
Nitrocellulose (NC)-based propellants have played a pivotal role in the development of energetic materials for both military and civilian applications. This review offers a comprehensive exploration of NC-based propellants, tracing their evolution from their historical origins as smokeless gunpowder to modern advancements. It discusses the chemical composition and classifications of NC propellants, along with continuous efforts to refine smokeless powder formulations through studies on smoke formation, residues, and additives.
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January 2025
State Key Laboratory of Wide-Bandgap Semiconductor Devices and Integrated Technology, Xidian University, Xi'an 710071, PR China.
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