Pulsed laser patterning of Toric contact lens inserts

Laser patterning is a promising technology for biomedical applications. In this research project, a novel laser based marking method for toric contact eye lenses has been proposed. Toric contact eye lenses are designed to address general blurring that occurs due to uneven cornea which is known as astigmatism. Toric lenses have two powers in them, created with curvatures at different angles of cone. For proper functioning of toric lenses their orientation with respect to eye is critical. So toric lenses are manufactured with some form of marking which helps in deciding the orientation with respect to eye. The proposed method is to use the principle of laser interferometry in marking the metal inserts which will subsequently be transferred to lens surface during injection molding. For the research project stainless steel was selected as the material from the commonly used materials for the lens inserts. The marking of stainless steel with respect to different laser parameters (e.g. peak pulse power, rep rate, polarization and marking time) was studied. Mathematical modeling has also been done to predict the effect of aspherical curvature of lens insert on marking parameters and to study the effect of laser interference on the marking quality and quantity of stainless steel. The proposed marking method will not only reduce the marking area on the toric lens but also increase the visibility of the marking. In addition, using the principle of interference in marking reduces the amount of laser energy required for marking which reduces the heat affected zone thereby increasing the life of high value added metal insert

Effect of grain boundaries on the interfacial behaviour of graphene-polyethylene nanocomposite

Aim of this article was to investigate the effect of grain boundaries on the interfacial properties of bi-crystalline graphene/polyethylene based nanocomposites. Molecular dynamics based atomistic simulations were performed in conjunction with the reactive force field parameters to capture atomic interactions within graphene and polyethylene atoms, whereas non-bonded interactions were considered for the interfacial properties. Atoms at the higher energy state in bi-crystalline graphene helps in improving the interaction at the nanocomposite interphase. Geometrical imperfections such as wrinkles and ripples helps the bi-crystalline graphene in increasing the number of adhesion points between the nanofiller and matrix, which eventually improves the strength and toughness of nanocomposite. These outcomes will help in opening new opportunities for defective nanofillers in the development of nanocomposites for future applications

Three Cavity Tunable MEMS Fabry Perot Interferometer

In this paper a four-mirror tunable micro electro-mechanical systems (MEMS)Fabry Perot Interferometer (FPI) concept is proposed with the mathematical model. Thespectral range of the proposed FPI lies in the infrared spectrum ranging from 2400 to 4018(nm). FPI can be finely tuned by deflecting the two middle mirrors (or by changing the threecavity lengths). Two different cases were separately considered for the tuning. In case one,tuning was achieved by deflecting mirror 2 only and in case two, both mirrors 2 and 3 weredeflected for the tuning of the FPI

Estimation of vacancy migration energy and mean energy path in a single crystal hcp zirconium by MD simulations

In the present work, we have estimated the vacancy migration energy in a single crystal of hcp Zr and also determined the mean energy path for this transition using molecular dynamics based simulations. The vacancy migration energy is estimated to be about 1.02 eV, which is quite close to the experimental and DFT data for hcp-Zr

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Not AvailableTwenty-eight varieties of Indian jujube were estimated for various health-promoting compounds such as ascorbic acid, total flavonoids, flavanol, O-dihydric phenol and total phenolics. The antioxidant capacity was also measured by cupric reducing antioxidant capacity (CUPRAC), ferric reducing antioxidant power (FRAP) and 1,1 diphenyl-2-picryl hydrazyl (DPPH) assays. The ascorbic acid content varied from 47.81 to 160.12mg/100g, total phenolics from 48.69 to 196.34 mg/100g, total flavonoids from 60.32 to 173.11mg/100g, flavanol from 25.21 to 70.59 mg/100g and O-dihydric phenol from 5.03 to 19.26 mg/100g fresh weight. The average antioxidant activities were 1.6–6.33 and 1.22–5.49μM TE/g as determined by the CUPRAC and FRAP assays, respectively. Likewise, according to the results obtained, cv. ZG-3 was found to exhibit the strongest DPPH free radical scavenging activity followed by Katha Phal and Thar Sevika. The study also revealed a considerable amount of variation among the genotypes tested in relation to their phenolic content and antioxidant activity.Not Availabl