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.

Structure and Electrical Properties of ZnO Nanoparticles Blend with POT-DBSA

In this study, we report on a successful preparation nanocomposites poly (o-toluidine) (POT) doping with dodecylbenzene sulfonate acid (DBSA)/ ZnO by in-situ polymerization of (o-toluidine) monomer using ZnO nanoparticles (the weight ratios OT/ZnO: 1/5%, 1/10%, 1/15%). The composite films have been prepared by using the casting method on different substrate depending on the type of measurement. The surface morphology properties of the prepared samples were studied by the field emission scanning electron microscopy (FESEM). The results of FESEM indicate that ZnO nanoparticles were successfully embedded in the POT via chemical interactions between ZnO and (O-toluidine) monomer and the EDX spectrum showed the presence of element Zn in POT-DBSA/ZnO composites. The crystal structure was measured by x-ray directional and its pattern revealed the presence of ZnO in dopant polymer, in the diffraction patterns of POT-DBSA. The intensity of the peaks was increased as the amount of ZnO nanoparticles increased in POT-DBSA. The typical rectifying behaviour indicated that the formation of a diode observes by the I–V characterization of POT-DBSA/ZnO composites at thin film layer with top Al thin layer contact.

Optimization of TriboelectricNanogenerator for Small Power Electronics

TriboelectricNanogenerators (TENGs) is a new era energy source to power portable small electronic devices. This paper presents the fabrication of vertical contact separation mode TENGs. Three different TENGs device prototypes are fabricated: (1) Kapton-Aluminium; (2) Teflon-Aluminium and (3) Room Temperature Vulcanizing (RTV)-Aluminium. To optimize the performance of TENGs the effect of various parameters such as thickness of dielectric layer, contact time between two layers and contact separation movement of layers have been observed. Experimental result demonstrates that the output voltage increases initially and then decreases with the increase in thickness of dielectric layer. It is also reported that output voltage of TENGs decreases and increases with the increase in contact time and contact separation movement respectively. In this work, an output voltage obtained from TENGs is suitable to drive applications based on small power electronics.

Improving the Vertical Thermal Conductivity of Carbon Fiber-Reinforced Epoxy Composites by Forming Layer-by-Layer Contact of Inorganic Crystals

A carbon fiber-reinforced polymer (CFRP) is a light and rigid composite applicable in various fields, such as in aviation and automobile industry. However, due to its low thermal conductivity, it does not dissipate heat sufficiently and thus accumulates heat stress. Here, we reported a facile and effective strategy to improve the through-thickness thermal conductivity of CFRP composites by using a layer-by-layer coating of inorganic crystals. They could provide efficient heat transfer pathways through layer-by-layer contact within the resulting composite material. The high thermally conductive CFRP composites were prepared by employing three types of inorganic crystal fillers composed of aluminum, magnesium, and copper on prepreg through the layer-by-layer coating process. The vertical thermal conductivity of pure CFRP was increased by up to 87% on using magnesium filler at a very low content of 0.01 wt %. It was also confirmed that the higher the thermal conductivity enhancement was, the better were the mechanical properties. Thus, we could demonstrate that the layer-by-layer inclusion of inorganic crystals can lead to improved through-thickness thermal conductivity and mechanical properties of composites, which might find applications in varied industrial fields.

Surface Removal of Copper Thin Film under the Ultrathin Water Environment for Nanoscale Process

The surface planarity and asperity removal behaviors of atomic scale under the ultrathin water environment was studied for the nanoscale process by molecular dynamics simulation. The monolayer atomic removal was achieved under the noncontact and monoatomic layer contact conditions with different water film thickness, and the newly formed surface is relatively smooth and no deformed layer and plastic defects exist. The nanoscale processing is governed by the interatomic adhering action during which the water film transmits the loading forces to Cu surface and thereby result in the migration and removal of surface atoms. With scratching depth ≥ 0.5 nm, the abrasive particle squeezed out the water film from scratching region and scratched Cu surface directly, leading to the surface quality deterioration mainly governed by the plowing action. This study brings the goals of “0 nm planarity, 0 residual defects and 0 polishing pressure” closer to us in the nanoscale process for the development of ultra-precision manufacture technology.