Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

An event-based state estimation for nonlinear systems under the impact of noise is considered, that may guarantee acceptable estimation performances and minimize the number of sent measurements from the sensor to a remote estimator. We design a Recursive Bayesian filter that calculate an approximated probability density functions for a given state estimation problem. For simplicity, the considered probability density functions are approximated using particle filtering approach. © 2016 University of MEDEA, Algeria.

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Department of Electrical Engineering

Proceedings of 2016 8th International Conference on Modelling, Identification and Control, ICMIC 2016

Nonlinear event-based state estimation using particle filtering approach

FEM simulation and single grit experimental techniques are available to get an insight into the chip formation mechanism in grinding operations. However, those are case specific. In the present work, an analytical method has been developed by considering specific energy criteria and Johnson's indentation theory to predict the modes of chip formation. The force acting on an abrasive grit at every instance in a trajectory path has been calculated by considering grit size, wheel size, kinematic conditions and work material properties. Yield coefficient and non-dimensional strain at the grit-work interaction have been computed to identify mainly the ploughing to cutting transition phase. © 2017 The Authors.

Department of Mechanical Engineering

Fulltext

Procedia CIRP

An Analytical Method for Prediction of Material Deformation Behavior in Grinding Using Single Grit Analogy

The ability to estimate grinding process responses, like the surface roughness, specific energy, cutting forces and temperature, is essential to understand and optimize abrasive grinding. Several models to predict the process behavior with various input parameters have been published. In all of them, the number of active grits per unit area is an important parameter; however, this parameter has been given limited attention. Due to the difficulties associated with the accurate prediction and measurement of grits per unit area, very few grinding models have considered this factor, and most treat it as a constant. The active grits count depends on the depth of cut, the type of wheel, and the nature of the workpiece material. In contrast, the cutting edges count depends mainly on wheel-dressing conditions. A method has been developed to predict the active grits count by assuming a stochastic distribution of abrasive grits and their physical interaction with the workpiece based on a presumed abrasive wear mechanism. In addition, the count of active cutting edges has been included by using dressing kinematics. The variation in the number of active grits count with the depth of cut, grit size, dressing conditions and work material nature was used to validate the efficacy of this newly-proposed, predictive method. © 2017 Elsevier B.V.

Wear

A method for prediction of active grits count in surface grinding

The paper investigates the potential challenges faced by conventional distance relays in case of thyristor controlled series capacitor (TCSC) compensated transmission systems. The mal-operations of back-up relays can trigger large scale cascaded outages. Detailed analysis on mal-operation of different zones of distance relay due to TCSC operation is carried out. The impact of TCSC on the relays of adjacent lines which provide back-up protection to the compensated line is observed. Finally, possible solutions to mitigate the problem associated with the impact of TCSC upon the conventional distance relays are discussed. The simulation studies are carried out on MATLAB environment. © 2016 IEEE.

2016 National Power Systems Conference, NPSC 2016

Exposing zone-2 and zone-3 mal-operations in thyristor-controlled series capacitor compensated transmission system

We describe a technique to extract room temperature parameters of Schottky diodes based on single or double-terminal configurations whose barrier height is bias dependent. This method allows us to extract the zero bias barrier height without specific knowledge of interface states or the existence of insulator layers at the metal-semiconductor boundaries. This technique enables us to establish the type of thermionic emission mechanism, limited by a bias dependent image force potential and/or diffusion, taking into account interfacial states or layers. This technique makes use of experimental current-voltage (I-V) characteristics measured at both bias polarities and different intensities of illumination and the corresponding voltage-dependent differential slope-voltage characteristics α=dln(I)/dln(V). This method is verified experimentally on a conventional p-Silicon based Schottky diode and on metal-semiconductor and metal-insulator-semiconductor diodes fabricated on n-silicon-on-insulator substrates. Pd/Au Schottky electrodes were used, while the insulator stack of the metal-insulator-semiconductor diodes comprises an HfO2 layer on top of an SiO2 layer. © 2017 Author(s).

Journal of Applied Physics

Simplified parameter extraction method for single and back-to-back Schottky diodes fabricated on silicon-on-insulator substrates

Recent blackouts have induced a sense of urgency among protection engineers to revisit the concept of zone-3 protection in power transmission network. Zone-3 mal-operation is reported to be one of the primary causes behind most of the cascaded outages. The main purpose of this paper is to present a supervisory control based wide area back-up protection scheme. A data-mining algorithm, known as decision trees, is used to classify the state of power transmission system. Further, phase angle of positive sequence integrated impedance is utilised to assist the existing zone-3 protection in order to avoid unnecessary tripping during stressed power system condition. The studies performed on western system coordinating council (WSCC)-9-bus system in Real Time Digital Simulator platform validate the proposed algorithm under various faults and stressed conditions. © 2016 IEEE.

Supervisory control based wide area back-up protection scheme for power transmission network

We carry out a linear elastic analysis to study wavy structure generation on lipid membrane by peripheral membrane proteins. We model the lipid membrane as linearly elastic and anisotropic material. The hydrophobic insertion by proteins into the lipid membrane has been idealized as penetration of rigid rod-like inclusions into the membrane and the electrostatic interaction between protein and membrane has been modeled by a distributed surface traction acting on the membrane surface. With the proposed model we study curvature generation by several binding domains of peripheral membrane proteins containing BAR domains and amphipathic alpha-helices. It is observed that electrostatic interaction is essential for curvature generation by the BAR domains. © 2017 Federation of European Biochemical Societies

FEBS Letters

Generation of wavy structure on lipid membrane by peripheral proteins: a linear elastic analysis

Texturing the rake face of the cutting tools has recently emerged as a promising and environment friendly method for reducing friction during machining. Laser surface texturing has been the most commonly used method for fabricating textures on the cutting tool. This paper reports the experimental study of fabricating an array of micro scale dimples on the rake face of high speed steel cutting tool using a pulsed Nd:YAG laser. The effect of the laser parameters like wavelength and fluence on the dimensions and form of individual dimples were studied. Analysis of results show that uniform circular shaped dimples with very little spatter can be obtained using low fluence levels at wavelength of 355 nm. An array of micro scale dimples were then fabricated on the cutting tool using the optimized parameter levels. A very low textured area density was used in order to understand the process of chip flow over the textures and study the effect of machining on individual dimples. This textured cutting tool was then used in orthogonal dry machining of Al7075-T6 aerospace alloy and compared with the performance of conventional tools. Use of textured cutting tools resulted in reduction of both cutting and thrust forces. The tool-chip contact length is also less in the case of textured tool. The results show that textured high speed steel tools can significantly improve the metal cutting process while dry machining ductile workpieces. © 2017 Elsevier B.V.

Surface and Coatings Technology

Performance of laser surface textured high speed steel cutting tool in machining of Al7075-T6 aerospace alloy

The present investigation has been made on the influence of temperature on the workability behavior, stresses and hardness of sintered Al-4%B4C at a strain rate of 0.1s-1 during upsetting. Al-4% B4C preforms were prepared with 90% of initial preform density and sintered at 550±10oC about 60 min. These sintered preforms were compressed in a hydraulic press at a strain rate of 0.1 s-1 until the initiation of the cracks appears on the free surface. The various stresses (σz, σθ, σm, σeff), formability stress index (β) and stress ratio parameters (σz/σeff, σm/σeff, σθ/σeff) were calculated and correlated with the true axial strain (Ez). Also the effect of different deformation temperatures on the hardness of Al-4%B4C preforms was studied in detail. © 2017 The Authors.

Procedia Engineering

Influence of Temperature on the Workability and Hardness of Sintered Al-4%B4C in Upsetting Test

Simulations and exhaust measurements of temperature and pollutants in a syngas-fired model trapped vortex combustor for stationary power generation applications are reported. Numerical simulations employing Reynolds-averaged Navier-Stokes (RANS) and large eddy simulations (LES) with presumed probability distribution function (PPDF) model were also carried out. Mixture fraction profiles in the trapped vortex combustor (TVC) cavity for nonreacting conditions show that LES simulations are able to capture the mean mixing field better than the RANS-based approach. This is attributed to the prediction of the jet decay rate and is reflected on the mean velocity magnitude fields, which reinforce this observation at different sections in the cavity. Both RANS and LES simulations show close agreement with the experimentally measured OH concentration; however, the RANS approach does not perform satisfactorily in capturing the trend of velocity magnitude. LES simulations satisfactorily capture the trend observed in exhaust measurements which is primarily attributed to the flame stabilization mechanism. In the exhaust measurements, mixing enhancement struts were employed and their effect was evaluated. The exhaust temperature pattern factor was found to be poor for baseline cases, but improved with the introduction of struts. NO emissions were steadily below 3 ppm across various flow conditions, whereas CO emissions tended to increase with increasing momentum flux ratios (MFRs) and mainstream fuel addition. Combustion efficiencies ∼96% were observed for all conditions. The performance characteristics were found to be favorable at higher MFRs with low pattern factors and high combustion efficiencies.