13 research outputs found
Investigation of deformation of the cornea during tonometry using FEM
A three dimensional finite element model of the human eye is developed to evaluate the force which will be applied over the surface of cornea during tonometry and gonioscopy tests. The standard tonometers and gonioscopy experiences deformation from 0.5mm to 3mm of the cornea is adopted during both point contact and boundary contact on the surface of the cornea. The results demonstrate the maximum force experienced by the tonometer with point contact at the center of the cornea for the maximum possible deformation of the cornea during tonometry. The study also analyzes for the force experienced by the tonometer or goniolens with boundary layer contact for the defined deformation of the cornea along the direction from cornea towards the retina
Rare earth element (REE) lanthanum doped zinc oxide (La: ZnO) nanomaterials: synthesis structural optical and antibacterial studies
Lanthanum (La) doped zinc oxide (ZnO) nanomaterials (LaxZn1-xO, x = 0.0, 0.03, 0.05, 0.07 M) were synthesized via co-precipitation method using zinc acetate, lanthanum nitrate as precursors, octylamine as capping and reducing agent. The structures, morphologies, optical activity and antibacterial properties of LaxZn1-xO were investigated by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, High resolution scanning electron microscopy (HR-SEM), Energy dispersive X-ray (EDX), UV–Visible, Photoluminescence (PL) spectroscopy. The antibacterial activities of LaxZn1-xO were tested by modified disc diffusion method. The XRD results showed that the La3+ ions were successfully incorporated into the ZnO host, and the products were well-crystalline. The average size of undoped and doped La-doped ZnO was found to be in the ranges from 15.64 to 10.18 nm. In addition, the sphere-like nanoparticles morphology of LaxZn1-xO was confirmed by HR-SEM images. The band gap of La-doped ZnO nanoparticles were varied with the La3+ ions doping concentration. In addition, increasing the doping concentration of La3+ ions in ZnO increases the defects in ZnO lattice and hence resulting red-shift in UV emission, which indicate the presence of narrow band-gap in doped nanoparticles
Protic Ionic Liquid Assisted Synthesis and Characterization of Ferromagnetic Cobalt Oxide Nanocatalyst
Cobalt oxide (Co3O4) nanocatalyst was synthesized by sol-gel method using the protic ionic liquid namely 1-butylimidazolium glycolate as solvent and stabilizer. The obtained Co3O4 nanocatalyst was characterized by powder X-ray diffraction (XRD), Fourier transform infrared, High resolution scanning electron microscopy (HR-SEM), Energy dispersive X-ray (EDX), High resolution transmission electron microscopy (HR-TEM), Selected area electron diffraction, UV–Visible diffuse reflectance spectroscopy, Photoluminescence spectroscopy, Brunauer–Emmett–Teller surface area and Vibrating sample magnetometer (VSM). Powder XRD results showed the well-crystalline cubic structure of synthesized Co3O4 with size of 19.29 nm. Also, the sphere-like morphology of Co3O4 nanocatalyst was confirmed by HR-SEM and HR-TEM images. Furthermore, the synthesized Co3O4 nanocatalyst possessed optical band gap values of 1.75 and 2.46 eV and hence acted as a semiconducting material. In addition, the presence of small hysteresis loop in Magnetic measurement (VSM) confirmed the ferromagnetic nature of Co3O4 nanoparticles. Moreover, the synthesized Co3O4 nanocatalyst found to be used in photo-catalytic degradation of methylene blue and exhibited 94.61% efficiency