RESUMO
Thermal control coating for spacecraft based on thermochromic film attracts increasing interest due to their ability of self-adaptive emittance switch and less resource consuming compared with traditional thermal control coatings. However, practical applications of thermochromic film for spacecraft are constrained by the low infrared emittance at a high temperature and narrow emittance tunability. In this work, a thermochromic film with simple structure, nearly perfect infrared emission and large emittance tunability is proposed for the application of spacecraft thermal control. The thermochromic film is a VO2-based superposed Fabry-Perot (FP) multilayer film, which is constructed by encapsulating three thin VO2 layers in four lossless BaF2 spacer on the Al substrate. The infrared emittance and emittance tunability of the superposed FP film is dramatically enhanced by the three superposed VO2-BaF2-Al FP resonances at wavelengths of 9, 15 and 20â µm, respectively. For VO2 layers under metallic state, the spectral normal emittance of the superposed FP film is close to unity in the entire mid-infrared spectral range, while for VO2 layers under dielectric state, the film is highly reflective. For the typical growth techniques of the VO2 layers considered here, the emittance tunability of the superposed FP film can exceed 0.70 with total normal emittance larger than 0.91 at high temperature, simultaneously. The largest total normal emittance of the superposed FP film can reach 0.95 with emittance tunability of 0.78. In addition, the infrared emission and emittance tunability performances of the superposed FP film remain excellent for incident angles up to 60°. This work proposes a simple structure with highly enhanced infrared emittance and emittance tunability that outperforms the existing thermochromic films, which could accelerate the application of thermochromic films in the field of spacecraft thermal control.
RESUMO
Objective Ginger (Zingiber officinale) is widely used as a spice in cooking and as a medicinal herb in traditional herbal medicine. The present study was to investigate the analgesic and anti-inflammatory activities of ginger oil in experimental animal models. Methods The analgesic effect of the oils was evaluated by the acetic acid and hot-plate test models of pain in mice. The anti-inflammatory effect of the oil was investigated in rats, using rat paw edema induced by carrageenan, adjuvant arthritis, and vascular permeability induced by bradykinin, arachidonic acid, and histamine. Indomethacin (1 mg/kg), Aspirin (0.5 g/kg) and Dexamethasone (2.5 mg/kg) were used respectively as reference drugs for comparison. Results The ginger oil (0.25-1.0 g/kg) produced significant analgesic effect against chemically- and thermally-induced nociceptive pain stimuli in mice (P < 0.05, 0.01). And the ginger oil (0.25-1.0 g/kg) also significantly inhibited carrageenan-induced paw edema, adjuvant arthritis, and inflammatory mediators-induced vascular permeability in rats (P < 0.05, 0.001). Conclusion These findings confirm that the ginger oil can be used to treat pain and chronic inflammation such as rheumatic arthritis.
