RESUMEN
A glass substrate, coated with a Parylene film, was coated with ZnO by three different methods: ultrasound, microwave, and microwave-plasma irradiation. These coating modes are simple, efficient, and environmentally friendly one-step processes. The structure of the coated products was characterized and compared using methods such as XRD, HR-SEM, EDS, RBS, and optical spectroscopy. Coating by ZnO nanoparticles was achieved for all three approaches. The products were found to differ in their particle sizes, coating thickness, and depth of penetration. All of the ZnO-Parylene-glass composites demonstrated a significant antibacterial activity against Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) strains.
Asunto(s)
Antiinfecciosos/farmacología , Materiales Biocompatibles Revestidos/química , Vidrio/química , Microondas , Polímeros/química , Xilenos/química , Óxido de Zinc/química , Antiinfecciosos/química , Escherichia coli/metabolismo , Ensayo de Materiales , Pruebas de Sensibilidad Microbiana , Modelos Químicos , Staphylococcus aureus/metabolismo , Difracción de Rayos XRESUMEN
We propose a method to characterize the geometrical texture of a granular packing at the particle scale including the steric hindrance effect. This method is based on the assumption of a maximum directional disorder (statistical entropy) compatible with both the strain-induced anisotropy of the contact network and steric exclusions. We show that the predicted statistics for the local configurations are in fairly good agreement with our numerical data.
RESUMEN
To improve the a priori estimation of optical quality of synthetic intracorneal implantation, numerical calculations were performed involving the intraocular overpressure, the cleavage depth and the type of the implant. Optical correction ratios, that were determined, are in close agreement with the obtained mechanical effects.
Asunto(s)
Afaquia Poscatarata/cirugía , Córnea/anatomía & histología , Lentes Intraoculares , Modelos Biológicos , Animales , Fenómenos Biomecánicos , Simulación por Computador , Córnea/fisiología , Córnea/cirugía , Elasticidad , Humanos , Presión Intraocular/fisiologíaRESUMEN
In the study of the deformation of objects by holographical interferometry, it is possible to determine directly strain components by measurement of the contrast of the fringes. With adequate geometry and a zero method, contrast measurements give accurate values of the strain components.