RESUMO
The mechanical recycling of discarded plastic products as resources for environmental preservation has recently gained research attention. In this context, it is necessary to use waste materials for fiber-reinforced thermoplastics (FRTP). Glass and carbon fibers are often damaged by shear and compression during melt-forming processes. To achieve a sustainable society, it is necessary for thermal recycling to produce minimal to no residue and for mechanical recycling to maintain the length of fibers used in FRTP to preserve their performance as a reinforcing agent. Aramid fibers (AFs) do not shorten during the melt-molding process, and their composites have excellent impact strength. On the other hand, plastics reinforced with glass or carbon fibers are reported to have a superior strength and modulus of elasticity compared to aramid fibers. This study investigates the dispersion of a carbon nanofiber (CNF), a whisker, as the third component in aramid-fiber-reinforced polypropylene (PP/AF). The results and discussion sections demonstrate how the dispersion of CNF in PP/AF can enhance the mechanical properties of injection-molded products without compromising their impact resistance. The proposed composition will have excellent material recyclability and initial mechanical properties compared to glass-fiber-reinforced thermoplastics.
RESUMO
PURPOSE: To retrospectively investigate the distribution of the low attenuation area (LAA) on dual energy perfusion CT (DEpCT) in comparison with the results of pulmonary function tests (PFTs) and quantitative CT measurements. MATERIALS AND METHODS: Twenty-eight patients (15 male and 13 female; mean age: 62.21 years) underwent DEpCT and PFTs within a 1-month interval. The ranges of the LAA on DEpCT were classified into six groups with attenuation values of 0-3, 0-5, 0-8, 0-10, 0-13 and 0-15 HU and the ratios of LAA in each group were compared with the percentage of forced expiratory volume in the 1st second (%FEV(1.0)), FEV(1.0)/forced vital capacity (FEV(1.0)/FVC) and the relative area of the lung with attenuation coefficients lower than -950 HU (RA(-950)). RESULTS: The LAAs on the DEpCT images were significantly correlated with the RA(-950), %FEV(1.0) and FEV(1.0)/FVC, and the regression analysis showed that the best values of LAA on DEpCT were 0-10 HU with RA(-950) (r=0.63), 0-8 HU with %FEV(1.0) (r=-0.52) and 0-8HU with FEV(1.0)/FVC (r=-0.61) per patient. CONCLUSION: The iodine disturbance on DEpCT had a moderate correlation with the results of the PFTs and RA(-950), but further examination would be needed for evaluation of iodine distribution.
