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Browsing by Author "Alves, Raquel"

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  • Electrochromic Device Composed of a Di-Urethanesil Electrolyte Incorporating Lithium Triflate and 1-Butyl-3-Methylimidazolium Chloride
    Publication . Gonçalves, Maria Cristina; Pereira, Rui F. P.; Alves, Raquel; Nunes, Sílvia C.; Fernandes, Mariana; Gonçalves, Helena M R; Pereira, Sónia; Silva, M. Manuela; Fortunato, Elvira; Rego, Rosa; Zea Bermudez, Verónica de
    A di-urethane cross-linked poly(oxyethylene)/silica hybrid matrix [di-urethanesil, d-Ut(600)], synthesized by the sol-gel process, was doped with lithium triflate (LiCF3SO3) and the 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) ionic liquid. The as-produced xerogel film is amorphous, transparent, flexible, homogeneous, hydrophilic, and has low nanoscale surface roughness. It exhibits an ionic conductivity of 3.64 × 10–6 and 5.00 × 10–4 S cm–1 at 21 and 100°C, respectively. This material was successfully tested as electrolyte in an electrochromic device (ECD) with the glass/ITO/a-WO3/d-Ut(600)10LiCF3SO3[Bmim]Cl/c-NiO/ITO/glass configuration, where a-WO3 and c-NiO stand for amorphous tungsten oxide and crystalline nickel oxide, respectively. The device demonstrated attractive electro-optical performance: fast response times (1–2 s for coloring and 50 s for bleaching), good optical memory [loss of transmittance (T) of only 41% after 3 months, at 555 nm], four mode modulation [bright mode (+3.0 V, T = 77% at 555 nm), semi-bright mode (−1.0 V, T = 60% at 555 nm), dark mode (−1.5 V, T = 38 % at 555 nm), and very dark mode (−2.0 V, T = 11% and −2.5 V, T = 7% at 555 nm)], excellent cycling stability denoting improvement with time, and high coloration efficiency [CEin = −6727 cm2 C–1 (32th cycle) and CEout = +2794 cm2 C–1 (480th cycle), at 555 nm].
    2020Journal article Open access Show more
  • Noise induced hearing loss among gym teachers
    Publication . Sousa, Aida; Rodrigues, Matilde; Alves, Raquel; Moreira, Inês
    health and to the organization. In fact, noise-induced hearing loss (NIHL) has been listed as one of the most prevalent self-reported illness in Europe (Eurostat, 2004), being subject of great concern at occupational settings. The development process of the NIHL is along the years of exposition, being the initial damage caused by loud sounds often small and the source of slight hearing problems like temporary hearing threshold shift.
    2014-09Conference object Open access Show more