Vignan University

About: Vignan University is a education organization based out in Guntur, Andhra Pradesh, India. It is known for research contribution in the topics: Computer science & Control theory. The organization has 1138 authors who have published 1381 publications receiving 7798 citations.

Cyclotriphosphazene nanofiber-reinforced polybenzoxazine/epoxy nanocomposites for low dielectric and flame-retardant applications

Abstract: In the present work, a halogen-free flame-retardant cyclotriphosphazene nanofiber-reinforced polybenzoxazine/epoxy (PBZ/EP/PZT) hybrid nanocomposites have been developed and characterized. Initially, equimolar quantities of benzoxazine and the epoxy matrix is blended and varying weight percentages (0, 0.5, 1.0 and 1.5 wt%) of PZT nanofiber are reinforced to obtain hybrid nanocomposites. It was observed that PBZ/EP/PZT nanocomposites possess higher values of glass transition temperatures (Tg—208 °C) and displayed enhanced thermal stability with high char yields than those of neat matrix. The flammability characteristics of the nanocomposites were studied on the basis of the LOI, UL-94 burning experiments as well as the analysis of residual chars of the tested bars after burning. The V-0 classification for the nanocomposites indicates that the incorporation of PZT nanofiber (1.5 wt%) imparts enhanced flame retardancy to the PBZ/EP matrix. The dielectric properties of these nanocomposites have been studied at 1 MHz over the temperature range between 30 and 200 °C. Data resulted from thermal, flame-retardant and dielectric studies indicate that the composite materials can be considered as the potential candidate for thermally stable fire and heat resistant, dielectric sealants, and encapsulants in electronic applications.

Ultrasound Assisted Synthesis of 3,4-Diyne Substituted Isocoumarin Derivatives: Identification of Potential Cytotoxic Agents.

Abstract: BACKGROUND The 3,4-diyne substituted isocoumarins have been designed, synthesized and explored as potential anti-proliferative agents. METHOD Ultrasound assisted synthesis of these compounds was carried out by using a three-step method involving (i) Pd/C-Cu catalyzed cross-coupling between the methyl 2-iodobenzoate and buta- 1,3-diynylbenzene followed by (ii) I2-mediated electrophilic cyclization of the resultant 2-(alk-1- ynyl)benzoate ester and (iii) subsequent alkynylation of 4-iodo-3-(phenylethynyl)-isocoumarin under Pd/C-Cu catalysis. CONCLUSION The synthesized compounds showed promising growth inhibition when tested against MDA-MB 231 and K562 cancer cell lines.

Simulation Process of Injection Molding and Optimization for Automobile Instrument Parameter in Embedded System

Abstract: The automobile instrument is the indispensable item that is essential to keep the driver conversant of the process of the engineer and the other system. There are different parameters involved in the automobile instrument, which requires a different process involved in creating the automobile parameter. This research is designed to show the simulation development of injection molding and optimization of automobile instrument parameters using different optimization techniques. In this paper, Taguchi Orthogonal parameter design and particle swarm optimization (PSO) are used to measure the shrinkage volume rate and warpage amount rate. Most of the studies are designed to calculate the reduction and warpage for the gate location and glass material. The Taguchi orthogonal design contains five different parameters which are inversely proportional to each other. Hence, by optimizing those parameters, the injection molding procedure is passed out. In this research, the paper is designed to process the injection molding for the automobile instrument parameter using optimization techniques.

Biochemical composition and nutritional value of Streptocephalus simplex as live feed in ornamental fish culture

Abstract: A feed trail was conducted to evaluate the efficiency of Streptocephalus simplex as a live feed in freshwater ornamental fish culture. The efficiency of live feed was compared with that of artificial/pellet diet to determine the growth rate biochemical parameters and carotenoid concentration of Carassius auratus for a period of 45 days. As a result the proximate composition on the S. simplex indicates that they are rich in protein, lipids, essential amino acids and fatty acids. Availability of these growth factors was perfectly reflected on the successful growth rate of C. auratus. Moreover, presence of carotenoids viz., astaxanthin (36.4 ± 2.4), canthaxanthin (23.6 ± 1.7), and β-carotene (1.7 ± 0.6) has improved the intensity of the skin color of commercially important ornamental fish C. auratus after feeding with S. simplex.

A current mode Schmitt trigger based on Current Differencing Transconductance Amplifier

Abstract: A current mode Schmitt trigger using Current Differencing Transconductance Amplifier (CDTA) is presented in this paper The proposed circuit employs only a single CDTA, without any passive component, that has been suitable for implementation of the IC design The operation of the proposed Schmitt trigger circuit has been observed and enforced at a supply voltage ± 085 V (bias current 32 µA) using Cadence and the model parameters of a gpdk 180 nm CMOS technology The Schmitt trigger circuit in this paper, which is realized using CDTA provides impervious to noise and insensitive to temperature