Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Department of Electrical Engineering

School of Electrical Engineering

Vellore Campus

2019 Innovations in Power and Advanced Computing Technologies (i-PACT)

Solution to Unit Commitment Using Lagrange Relaxation with Whale Optimization Method

Journal of Energy Storage

Optimal size allocation of superconducting magnetic energy storage system based unit commitment

Microfluidics is an emerging field giving rise to a number of scientific developments with wide applications in proteomics, genomics, DNA analysis, drug delivery systems and lab-on-a-chip. Among the various microfluidic structures, microchannels form an integral part of Lab-on-a-chip devices for clinical diagnosis. The geometrical accuracy and surface finish quality of the microchannels affect the performance of microfluidic systems, thereby demanding a precise microfabrication technique for realizing microchannels. Spark assisted chemical engraving (SACE) is an effective hybrid micromachining technique used for micro-structuring non-conducting substrates such as glass and ceramics. In the present work, we report on a room temperature coated thick insulating film for improving the quality of the microchannels realized using a SACE process. The insulator film coated around a tool electrode confines the spark discharges only to the bottom surface of the tool. Moreover, the proposed insulator coating methodology does not require any cost intensive equipment, carrier gases, vacuum units and a clean room environment. Experimental results demonstrate that for same process parameters a micro-channel fabricated using an insulated tool has its overcut reduced by 57.8% and machining depth improved by 19.53% with a smooth surface and regular edges as compared to the channels realized using an uninsulated tool. © 2017 Taylor &amp; Francis.

Electronics

School of Electronics Engineering

Chennai Campus

Materials and Manufacturing Processes

Fabrication of precise microchannels using a side-insulated tool in a spark assisted chemical engraving process

In the present study, a detailed experimental investigation is carried out on a constant velocity-feed drilling technique of an electrochemical discharge machining (ECDM) process to fabricate micro-holes on quartz substrates. First, cylindrical micro-tools of four different diameters (145 μm, 195 μm, 300 μm and 400 μm) with varying tool feed rates (TFRs) (0.3 μm s-1-1.9 μm s-1) are considered to study their influence on the precision of fabricated micro-holes while using a 30 wt% NaOH solution as an electrolyte, a machining voltage of 30 V and an initial working gap of 5 μm. Minimum micro-hole diameter and overcut were achieved at a TFR 0.8 μm s-1 for the cylindrical tools of all diameters. Considering 0.8 μm s-1 as an optimal TFR, the influence of tool shape on the quality metrics was investigated using a spherical shaped tool electrode having a ball diameter of 145 μm and a spindle diameter of 90 μm. A micro-hole realized using the spherical shaped tool shows that the entrance diameter, entrance overcut, central diameter and central overcut are reduced by 12%, 29%, 28% and 67% respectively as compared to that realized using a cylindrical tool for the same process parameters. Micro-holes with improved precision and aspect ratio are achieved without using cost intensive equipments, feedback mechanisms, coated tools and tool rotation. © 2018 IOP Publishing Ltd.

Journal of Micromechanics and Microengineering

Fabrication of precise micro-holes on quartz substrates with improved aspect ratio using a constant velocity-feed drilling technique of an ECDM process

Electrochemical discharge machining (ECDM) process is a recent non-traditional machining technique used for structuring insulating materials like glass and ceramic substrates. In this work, systematic experimental investigations have been carried out to study the electrical and 2-D machining characteristics of an ECDM process. The influence of various process parameters like electrolyte type, electrolytic concentration, tool travel rate (TTR) and applied voltage on the process characteristics have been studied. Two different electrolytes, i.e., KOH and NaOH with concentrations varying from 10 to 50 % have been used to study their effect on critical voltage (Vc) and critical current (Ic). A cylindrical tungsten carbide tool of diameter 0.4 mm with varying TTRs (ranging from 0.3 to 4 mm/min) and an applied voltage varying from Vc + 2 V to Vc + 5 V is used for realizing microchannels. The influence of these parameters on the quality factors such as geometric accuracy, surface smoothness and channel outlines are explored using the optical images of the machined channels. Experimental results demonstrate that precise channels with smooth surface, and regular channel edges can be obtained at an applied voltage of Vc + 4 V and TTRs between 1 and 2 mm/min. © 2016, Springer-Verlag Berlin Heidelberg.

VIT Unitversity

Microsystem Technologies

Experimental investigations on the electrical and 2D-machining characteristics of an electrochemical discharge machining (ECDM) process

Sustainable Energy Technologies and Assessments

Optimal location and sizing of distributed generation unit using intelligent water drop algorithm

Electro-chemical discharge machining (ECDM) is a recent technique used to machine insulating materials like glass and ceramics. This paper presents the results of the combined effects of tool feed-rate and tool shape on the micro-machining of a quartz substrate using an ECDM process. The investigations show that a tool with a spherical tip provides a profile with a reduced entrance diameter and the overcut can be considerably reduced by controlling the tool feed-rate. © 2015 IEEE.

2015 2nd International Symposium on Physics and Technology of Sensors (ISPTS)

Effect of tool shape and tool feed rate on the machined profile of a quartz substrate using an electrochemical discharge machining process

This paper discusses the development of real-time simulation platform using digital signal processor (DSP) for photovoltaic (PV) system to study maximum power tracking algorithms in the laboratory. In this paper, PV module is simulated and deployed in TMS320F28335 to emulate the characteristics of PV at different temperature and irradiation with two DC voltage source. Further, maximum power point tracking (MPPT) of PV module with statistical method is developed. In order to evaluate the performance of the proposed MPPT control algorithm, the authors propose a real-time PV simulation system consisting of a PV module with a buck converter using a DSP and two DC voltage source to emulate the temperature and irradiation. Further, the proposed statistical MPPT is compared with the performance of the existing perturb and observe MPPT algorithm. Also, the performance of MPPT algorithms is tested with PV and a buck converter at different temperature and irradiation using hypothetical source. This scheme is validated with that of standard conditions given on the PV data sheet. This work may enable more researchers to study the integration of renewable energy sources and power electronics circuits at a low-cost without damaging the system. © Institution of Engineers Australia, 2015.

Department of Control and Automation

Australian Journal of Electrical & Electronics Engineering

Study and development of digital signal processor based real-time simulation platform for photovoltaic system with buck converter for maximum power tracking

Microemulsions as drug delivery vehicles have gained fame for their capability of solubilizing aqueous insoluble drugs with poor bioavailability. Ramipril, one of its kind, was chosen to improve its physico-chemical properties by incorporating in cinnamon oil based microemulsion system. This enabled enhanced solubilization and particle size reduction with mean droplet diameter in the range of 7.2 nm with minimum polydispersity index. The comparison made between the drug-loaded formulation and its blank counterparts demonstrated similarity in the visual appearances, turbidity and viscosity measurements; and very slight increase regarding the pH and conductivity measurements. Owing to the best performance of the drug delivery vehicle, acute toxicity was performed on female Wistar rats. The rats observed no signs of mortality or toxicity at the end of 21 days when a highest volume (1 ml/100 gm body weight) of the vehicle was given orally. Haematological parameters were also observed normal as compared to control rats. The vehicle would place a possible outcome in futuristic work. Copyright © 2014 American Scientific Publishers All rights reserved.

Centre for Nanobiotechnology

Journal of Bionanoscience

Particle Size Reduction of Ramipril Using Cinnamon Oil Based Microemulsion System and Acute Toxicity of the Vehicle in Female Wistar Rats

Microemulsions are thermodynamically stable isotropic systems comprising of oil, surfactant and water. Cinnamon oil (Cinnamomum zeylanicum) microemulsion was formulated using non-ionic surfactant Tween 20 and water. With oil to surfactant (v/v) ratio of 1:4, cinnamon oil microemulsion (CMF4) was formulated having droplet diameter of 5.79 and kinetically stable for 240 days. TEM images confirmed the spherical morphology of emulsion droplets. Surfactant concentration demonstrated a negative correlation with droplet diameter and turbidity but positive correlation with stability and viscosity. Formulated microemulsion (CMF4) was evaluated for bactericidal activity against . Staphylococcus aureus by dose and time dependent killing experiment. SEM analysis suggested that microemulsion treatment resulted in alteration of permeability and surface features of bacterial cell membrane which lead to lysis and cell death. CMF4 showed no erythema for skin irritation test in wistar rats and triggered wound-healing process in wistar rats. Control group without any treatment, cinnamon oil only and neomycin treated group healed in 20, 16 and 16 days, whereas cinnamon oil formulation (CMF4) treated group was healed in 14 days. © 2013 Elsevier B.V.

Colloids and Surfaces B: Biointerfaces

Antibacterial microemulsion prevents sepsis and triggers healing of wound in wistar rats

Cinnamon oil (extracted from Cinnamomum zeylanicum) nanoemulsion was formulated using Tween 80 and water by ultrasonic emulsification. Process of nanoemulsion formulation was optimized for parameters such as surfactant concentration, oil-surfactant mixing ratio and emulsification time. Surfactant concentration was found to be inversely related to droplet size and directly related to stability. Increase in emulsification time resulted in decrease in droplet diameter. Stable cinnamon oil formulation (CF3) having droplet diameter of 65 nm was formulated after sonication for 30 min. Formulated nanoemulsion was evaluated for bactericidal efficacy against Bacillus cereus. Time and concentration dependent killing of B. cereus cells was observed upon treatment with nanoemulsion. Even at a higher dilution of CF3, significant reduction in bacterial population was observed. Alteration in membrane permeability of interacted samples was suggested by quantifying the release of UV absorbing materials. Bacterial staining with acridine orange/ethidium bromide supported kinetics of killing data and also substantiated the above findings of alteration in membrane permeability. FTIR illustrated disappearance of peak corresponding phosphate vibration at 1078 cm-1 and 536 cm-1, and peak associated with vibration of acyl chains of lipid at 2852 cm-1 was shifted to 2854 cm-1 which suggested deformation of membrane phospholipids in nanoemulsion treated cells. SEM observations demonstrated membrane distortion leading to cell lysis. These results propose the potential use of cinnamon oil nanoemulsion for preservation of minimally processed food. Copyright © 2013 American Scientific Publishers All rights reserved.