Techno India

About: Techno India is a based out in . It is known for research contribution in the topics: Computer science & Cloud computing. The organization has 4724 authors who have published 4005 publications receiving 34112 citations.

Synthesis of nickel oxide grafted graphene oxide nanocomposites - A systematic research on chemisorption of heavy metal ions and its antibacterial activity

Abstract: Graphene Oxide-Nickel Oxide (GO-NiO) nanocomposite was prepared by a simple combined hydrothermal method. The nanocomposites were characterized by Field-Emission Scanning Electron Microscopy (FESEM), X-Ray Powder Diffraction (XRD), Fourier Transfer Infrared (FT-IR) Spectroscopy, Transmission Electron Microscopy (TEM), Thermogravimetric (TGA) Analysis, and Energy Dispersive X-ray analysis (EDX). SEM and TEM analysis indicates the formation of flaky structured nanoparticles with sizes ranges from 100 to 200 nm. GO-NiO nanocomposite has exceptional adsorption capacity and very high adsorption rates towards removing Pb2+ and Cd2+ metal ions. Our work illustrates that the adsorption data were best fit for Langmuir adsorption isotherm among Freundlich and D–R isotherm providing a high adsorption capacity of 208.8 and 324.7 mgg−1 for Pb2+ and Cd2+ metal ions respectively. At the same time, the kinetics followed the pseudo-second-order model and other kinetic parameters like pseudo-first-order, Elovich and Intraparticular diffusions were also discussed. The influence of concentration and pH were studied. The GO-NiO nanomaterial, as formed, was examined for various Gram-positive and Gram-negative pathogenic bacteria.

Segmentation of retinal vasculature using phase congruency and hierarchical clustering

Abstract: Extraction of blood vessels in the fundus images having bright lesions is difficult. A novel approach for the automated segmentation of the vasculature in fundus images with bright lesions is presented in this paper. In this approach, the intensity information from red and green channels of the same fundus image is used to modify the non-uniform illumination in fundus images. Phase Congruency is employed to improve the contrast of vessel segments against the retinal background. The contrast enhanced vessels are then segmented by using hierarchical clustering based histogram thresholding. The experimental study has proved that the proposed algorithm demonstrates better performance than the other vessel detection algorithms reported in the recent literature.

Development of a virtualized networking lab using GNS3 and VMware workstation

Abstract: Many universities offer students to work on live networking equipment. Unfortunately this is not very efficient for teaching networking labs, especially if the size of the class is really large. The aim of this project is to create a virtual lab to help overcome the existing issues of limited hardware and accessibility in physical laboratories. The lab gives students the ability to deploy virtual instances of real life network devices. This lab will run within a single physical computer, hence providing a cheap and accessible solution for performing network practicals.

Accurate Online Junction Temperature Estimation of IGBT Using Inflection Point Based Updated I–V Characteristics

Abstract: The junction temperature ( $T_j$ ) estimation of the insulated gate bipolar transistor (IGBT) is important for reliable operation of the power converters in various applications. For $T_j$ estimation, on -state collector-emitter voltage ( $v_{ce}$ ) at higher collector currents ( $i_c$ ) is widely used temperature sensitive electrical parameter (TSEP). For real-time $T_j$ estimation, this TSEP is calibrated using the I–V characteristics of the new IGBT. Due to bond-wire degradation, the original I–V characteristics of IGBT changes resulting in inaccurate $T_j$ estimation. In this article, a technique is proposed to update the I–V characteristics of the degraded IGBT, without affecting the normal operation of the power converter. It is achieved by estimating the increment in bond-wire resistance ( $\triangle R_{con}$ ) by using real-time samples of $v_{ce}$ and inductor current. The mathematical analysis is also presented to find an error in estimated $\triangle R_{con}$ . The major contributions of this article are as follows: a) it enables the accurate $T_j$ estimation of the IGBT throughout its lifetime; and b) it also provides the parameter $\triangle R_{con}$ , which could be utilized in condition monitoring of the IGBT. Further no additional circuitry is required. The proposed technique is validated on experimental setup, which is developed in the laboratory. The error in $T_j$ estimation is observed within $1$ °C the degraded IGBT, which shows the effectiveness of the proposed scheme.

Design of coaxial cavity for high power magnetron

Abstract: This paper presents electromagnetic design of coaxial cavity for high power X-band coaxial magnetron. The initial dimensions of the cavity have been calculated by solving transcendental equation using graphical method. The eigenmode simulation has been carried out by using CST MW Studio. It is found that TE011 mode occurs at 9.3 GHz. Output coupler of cavity is designed to launch RF power into WR112. Proposed design is analyzed in terms of performance parameters i.e., unloaded, loaded, and external quality factors. Circuit efficiency and coupling coefficient are analyzed by varying critical geometrical parameters. Unloaded Q factor of 13108 is achieved for circuit efficiency of 93%.