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

The rate of collision and the relative velocities of the colliding particles in turbulent flows are a crucial part of several natural phenomena, e.g. rain formation in warm clouds and planetesimal formation in protoplanetary discs. The particles are often modelled as passive, but heavy and inertial. Within this model, large relative velocities emerge due to formation of singularities (caustics) of the gradient matrix of the velocities of the particles. Using extensive direct numerical simulations of heavy particles in both two (direct and inverse cascade) and three-dimensional turbulent flows, we calculate the rate of formation of caustics, J as a function of the Stokes number (St). The best approximation to our data is J∼exp⁡ (-C/St), in the limit St→0 where C is a non-universal constant. This article is part of the theme issue 'Scaling the turbulence edifice (part 2)'. © 2022 The Author(s).

Department of Physics

World University root node

Fulltext

Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences

Rate of formation of caustics in heavy particles advected by turbulence

This study aims to develop a pulse classification algorithm to understand wire electric discharge machining (wire EDM) process stability and performance based on the discharge pulse characteristics. Also, a process data driven failure prediction system is proposed. The wire EDM monitoring system includes high sampling rate differential probes and current probes. The features extracted through pulse train analysis were spark discharge energy, ignition delay time, spark frequency and proportion of various discharges. A pulse discrimination algorithm was proposed, which classifies the discharges into open circuit sparks, arc discharges, short circuit sparks and normal sparks. It was observed that higher proportions of short circuit pulses resulted in inferior part quality. The differences in the pulse cycle during stable and unstable machining were studied based on the extracted features. It was found that the discharge frequency and the proportion of arc and short circuit pulses were extremely high before the wire breakages. An artificial neural network (ANN) model was developed to predict the process responses, like cutting speed and surface roughness, from the process data. Also, an intelligent algorithm was developed based on the extracted in-process data to predict the unstable conditions, leading to machining failures. The accuracy of the algorithm was confirmed to be very high by conducting confirmation tests.

Department of Mechanical Engineering

Machining Science and Technology

Performance monitoring and failure prediction system for wire electric discharge machining process through multiple sensor signals

Bulletin of the American Physical Society

Crystal nucleation and liquid-liquid transition in deeply supercooled silicon

Cavity expansion and contraction solutions for cylindrical and spherical cavities in unsaturated residual soils are presented in this paper. Varying soil state in the plastic zone is accounted by a numerical approach, wherein an element-by-element discretization of the plastic zone of both expanding and contracting cavities is carried out. Unlike existing methods utilizing self-similarity technique, the solution procedure enables the prediction of entire soil-state at any stage of expansion and subsequent contraction. It is also applicable for both cavity creation and expansion problems. The approach adopts constant contribution of suction to effective stress (constant Xs drainage condition) for analysis. The analysis procedure is validated by interpreting the previously reported pressure meter test results in lateritic residual soil. The typical cavity expansion and contraction characteristics of unsaturated Indian lateritic soil were then examined using this solution procedure. The effect of initial soil-state on cavity limit pressure, plastic radius, reverse yield pressure, and reverse plastic radius are also presented.

Department of Civil Engineering

Geomechanics and Engineering

Analysis of cavity expansion and contraction in unsaturated residual soils

Surface grinding is observed to be an inevitable machining event in many of the functional engineering surfaces after pre-processing stages such as milling. Prediction of roughness profile after grinding on such initial surfaces, for selected operating conditions and grinding wheel specification, is always an interesting topic of investigation. Though a number of models have been reported in prior art, value additions through hybrid modelling strategies have been always contributing positively to this field of research due to the stochastic nature of abrasive interactions. Since feed rate of work piece is identified as a key grinding variable influencing the surface roughness, present paper introduces grain trajectory addition and elimination algorithm driven by feed based time scale to predict the ground surface topography. A realistic initial surface modelling is considered using meshless moving least square approximation incorporating both roughness as well as geometric deviation, expected to be imparted during pre-grinding stages. The algorithm is configured to compute two dimensional roughness parameters from the simulated surface profiles and these results are compared with experimental outcomes at various depths of grinding to validate the proposed model. © IMechE 2022.

Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering

Feed based trajectory addition and elimination algorithm combined with stochastic meshless modelling to simulate roughness in surface grinding

The paper presents structural diagrams of the control system of a robotic system with feedback on the patient’s effort and without it, illustrates the conditions for using each of them; a method is prepared to increase the reliability of data on the applied efforts, associated with the use of strain gauges in the absence of actions of the patient’s motor organs; an example of the patient’s motivation to perform ”correct” movements, ”helping” the mechanism, consisting in changing the speed of movement to form the patient’s feeling that the mechanism moves due to his efforts; a mathematical model of the robotic system was obtained, graphs were constructed demonstrating the accuracy of working out a given trajectory due to the anthropometric parameters of the patient.

2nd International Conference on Robotics and Control Engineering

Control system for a robotic system for rehabilitation of lower limbs with feedback on the patient’s effort

This paper focusses on the development of a Cartesian parallel manipulator (CPM) having multiple limb assembly configurations. An optimal configuration of the 3-PRRR CPM is identified after analysing the interference-free workspace of various limb assembly conditions, where each leg comprises an active prismatic joint followed by three revolute joints. The validation of the link interference detection algorithm is carried out using a virtual prototype. The Euler–Lagrange dynamic modelling of the CPM is validated using one of the well-known multi-body simulation packages namely, ADAMS. The paper proposes a detailed design and performance analyses of a motion controller for the proposed manipulator, based on a finite-time sliding mode scheme. A Graphical User Interface (GUI) is also developed using the MATLAB App Designer, which ensures easier and intuitive synthesis of the CPM. The development of an in-house functional prototype is also presented in this work. © IMechE 2022.

Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science

Numerical investigations, development and control of a cartesian (3-PRRR) parallel manipulator

Department of Humanities and Social Sciences

Feminism &Psychology

Book Review: Bisexual and pansexual identities: Exploring and challenging invisibility and invalidation by Nikki Hayfield

A modular platform for the synthesis of tunable aza-oxa-based macrocycles was established. Modulations in the backbone and the side-chain functional groups have been rendered to achieve the tunable property. These aza-oxa-based macrocycles can also differ in the number of heteroatoms in the backbone and the ring size of the macrocycles. For the proof of concept, a library of macrocycles was synthesized with various hanging functional groups, different combinations of heteroatoms, and ring sizes in the range of 17–27 atoms and was characterized by NMR and mass spectrometry. In light of the importance of the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction and the significance of triazole groups for various applications, we employed the click-reaction-based macrocyclization. The competence of the synthesized macrocycles in various biomedical applications was proven by studying the interactions with the serum albumin proteins; bovine serum albumin and human serum albumin. It was observed that some candidates, based on their hanging functional groups and specific backbone atoms, could interact well with the protein, thus improving the bioactive properties. On the whole, this work is a proof-of-concept to explore the backbone-and side-chain-tunable macrocycle for different properties and applications. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

Department of Chemistry

Molecules

Aza-Oxa-Triazole Based Macrocycles with Tunable Properties: Design, Synthesis, and Bioactivity

Structural diversity and tunable properties achieved by a defined monomeric sequence are the trademarks of a sequence-defined polymer (SDP). Herein, we report a modular synthetic platform where, in addition to the provision of changing the side chain, the backbone functional groups of the SDP can also be tuned among three key functional groups, namely dithiocarbamate (DTC), ester and amide. An efficient synthetic strategy has been developed to incorporate DTC into the SDP backbone without the need for separate design of the monomer. This unique strategy with the potential to vary both the backbone as well as the side chain is, to the best of our knowledge, the first report in the field of man-made SDPs. Three different classes of sequence-defined oligomers (SDOs) have been synthesized: (i) SDO1 with DTC alone in the backbone; (ii) SDO2 with DTC and ester in the backbone; and (iii) SDO3 with DTC and ester in the backbone and amide in the side-chain linkage. The structure-activity relationships of the three SDOs were investigated, which is important for their biomedical and material applications. This led to the conclusion that SDO1 with DTC functionality was stable under conditions of hydrolysis, heat and acid treatment, whereas SDO2 (DTC and ester) and SDO3 (DTC, ester and amide) are not stable under those conditions. On the other hand, for applications related to toxic Hg2+ removal, SDO3, which contained all three functional groups (DTC, ester and amide), was the most efficient, followed by SDO2 (DTC and ester) with medium efficiency and SDO1 (DTC) with the lowest efficiency. The investigation of the protein binding affinity with serum albumin concluded that all three SDOs are transportable via serum proteins. Taken together, this is a proof-of-concept to explore SDOs with tunable backbones and side-chains to modulate their properties and employ the best suited SDO for any given application. © 2022 The Royal Society of Chemistry.

Polymer Chemistry

Backbone and side chain-linker tunability among dithiocarbamate, ester and amide in sequence-defined oligomers: synthesis and structure–property–function relationship