Browsing by Author "Yu, Y"

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    Biofouling control by hydrophilic surface modification of polypropylene feed spacers by plasma polymerisation
    (Elsevier, 2014-02-17) Reid, K; Dixon, M; Pelekani, C; Jarvis, K; Willis, M; Yu, Y
    Biofouling compromises the efficiency of membrane desalination systems, especially energy and product water quality. Feed spacers employed in conventional spiral wound membranes create turbulence to minimise concentration polarisation. Research demonstrates that feed spacers can enhance biological growth within membrane elements. In combination with the strong link between fouling and surface hydrophobicity chemical modification of feed spacers could help counteract biofouling potential. In this study, an evaluation of feed spacers coated with diglyme using plasma polymerisation was assessed. Low energy density treatment was associated with an increase in biofouling, compared with the control, consistent with insufficient cross-linking of the diglyme monomer to the spacer surface. Increasing energy density treatment resulted in fouling performance approaching that of, or slightly better than the control. It is possible that batch recirculation type experiments may not best facilitate assessment of biofouling potential in single-pass cross-flow membrane systems. The study demonstrated that plasma treatment of conventional feed spacers has potential to reduce affinity for bacterial attachment, and may provide a viable and complementary approach to direct membrane surface modification for biofouling control. Further studies to quantify changes associated with diglyme plasma polymerisation and establish optimum conditions for biofouling minimisation are recommended. © 2013, Elsevier B.V.
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    Formation mechanism of black LiTaO3 single crystals through chemical reduction
    (Wiley-Blackwell, 2011-02-01) Yan, T; Zheng, FF; Yu, Y; Qin, SB; Liu, H; Wang, JY; Yu, DH
    Lithium tantalate (LiTaO3, LT) wafers of different colors were prepared through chemical reduction of regular congruent LT wafers. Samples with different colors corresponding to different annealing temperatures were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and measurements of the Curie temperature and density. It was found that chemical reduction does not influence the basic LT structure. The Ta charge state change due to chemical reduction was found to be the main reason for the formation of black LT wafers.© 2011, Wiley-Blackwell
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    Gallium-doped Li7La3Zr2O12 garnet-type electrolytes with high lithium-ion conductivity
    (American Chemical Society, 2016-12-22) Wu, JF; Chen, EY; Yu, Y; Liu, L; Pang, WK; Peterson, VK; Guo, X
    Owing to their high conductivity, crystalline Li7–3xGaxLa3Zr2O12 garnets are promising electrolytes for all-solid-state lithium-ion batteries. Herein, the influence of Ga doping on the phase, lithium-ion distribution, and conductivity of Li7–3xGaxLa3Zr2O12 garnets is investigated, with the determined concentration and mobility of lithium ions shedding light on the origin of the high conductivity of Li7–3xGaxLa3Zr2O12. When the Ga concentration exceeds 0.20 Ga per formula unit, the garnet-type material is found to assume a cubic structure, but lower Ga concentrations result in the coexistence of cubic and tetragonal phases. Most lithium within Li7–3xGaxLa3Zr2O12 is found to reside at the octahedral 96h site, away from the central octahedral 48g site, while the remaining lithium resides at the tetrahedral 24d site. Such kind of lithium distribution leads to high lithium-ion mobility, which is the origin of the high conductivity; the highest lithium-ion conductivity of 1.46 mS/cm at 25 °C is found to be achieved for Li7–3xGaxLa3Zr2O12 at x = 0.25. Additionally, there are two lithium-ion migration pathways in the Li7–3xGaxLa3Zr2O12 garnets: 96h-96h and 24d-96h-24d, but the lithium ions transporting through the 96h-96h pathway determine the overall conductivity. © 2016 American Chemical Society
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    On the temperature dependence of the density of states of liquids at low energies
    (Springer Nature, 2024-08-13) Jin, S; Fan, X; Stamper, C; Mole, RA; Yu, Y; Yu, DH; Baggioli, B; Hong, L
    We report neutron-scattering measurements of the density of states (DOS) of water and liquid Fomblin in a wide range of temperatures. In the liquid phase, we confirm the presence of a universal low-energy linear scaling of the experimental DOS as a function of the frequency, g(w) = a(T)w , which persists at all temperatures. The low-frequency scaling of the DOS exhibits a sharp jump at the melting point of water, below which the standard Debye’s law, g(w) ∝ w2 , is recovered. On the contrary, in Fomblin, we observe a continuous transition between the two exponents reflecting its glassy dynamics, which is confirmed by structure measurements. More importantly, in both systems, we find that the slope a(T) grows with temperature following an exponential Arrhenius-like form, a(T) ∝ exp(−/T) . We confirm this experimental trend using molecular dynamics simulations and show that the prediction of instantaneous normal mode (INM) theory for a(T) is in qualitative agreement with the experimental data. © The Authors - Open Access This article is licensed under a Creative Commons Attribution 4.0 International License.