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

We have synthesized single crystals of Na2(Ir1-xTix)O3 and polycrystals of Li2(Ir1-xTix)O3 and studied the effect of magnetic depletion on the magnetic properties by measurements of the magnetic susceptibility, specific heat, and magnetocaloric effect at temperatures down to 0.1 K. In both systems, the nonmagnetic substitution rapidly changes the magnetically ordered ground state into a spin glass, indicating strong frustration. While for the Li system the Weiss temperature ΘW remains unchanged up to x=0.55, a strong decrease |ΘW| is found for the Na system. This suggests that only for the former system magnetic exchange beyond nearest neighbors is dominating. This is also corroborated by the observation of a smeared quantum phase transition in Li2(Ir1-xTix)O3 near x=0.5, i.e., much beyond the site percolation threshold of the honeycomb lattice. © 2014 American Physical Society.

Department of Physics

World University root node

Fulltext

Physical Review B - Condensed Matter and Materials Physics

Effect of nonmagnetic dilution in the honeycomb-lattice iridates Na2 IrO3 and Li2 IrO3

The use of fibre reinforced concrete (FRC) for applications such as slabs-on-grade and pavements has been established to be advantageous due to the superior crack resistance properties, enhanced post cracking moment carrying capacity, and higher performance under fatigue, shrinkage and temperature stresses. In this context, the goal of this doctoral work is to develop and propose a comprehensive methodology for the design of fibre reinforced concrete pavements/slabs-on-grade incorporating the inelastic design techniques and material characteristics specific to FRC. The material parameter adopted in design is the equivalent flexural strength at a specified deflection. A database of flexural toughness parameters based on existing codes has been prepared for typical fibre concretes incorporating various fibres in different dosages and also used for comparison of material performance. The paper discusses the proposed design methodology based on yield line analysis, which results in an economical solution with fibre concretes in comparison to plain concrete. Emphasis has also been given to fatigue stress design in the case of pavements by incorporating a stress correction factor based on S-N relations of FRC. The need to determine the actual temperature differential in slabs has also been illustrated based on the results from experimental program performed at IIT Madras.

Environmental Sciences and Sustainable Engineering Centre (ESSENCE)

Proceedings of the 10th fib International PhD Symposium in Civil Engineering

A design methodology for fibre reinforced concrete pavements and slabs-on-grade

Several calorimetric techniques are available for the sequential estimation of thermal conductivities of composites by conducting heat balance successively along the principal directions. Such methods are time consuming and require three samples for estimating the properties. The hollow core, in combination with rigid face sheets, helps in achieving a high strength to-weight ratio, as demanded by its application. Because the manufacturing process of composites inevitably gives rise to a joint resistance between the face sheets and the core, due to the presence of an adhesive, its effect becomes detrimental in the estimation of effective thermal transport properties. A combination of several values of tridimensional effective thermal conductivities may lead to same temperature distribution; hence, the problem is ill posed in nature and requires regularization prior, an engineering intuition, or a combination of both.

Department of Mechanical Engineering

Journal of Thermophysics and Heat Transfer

Joint conductance effects on estimation of effective thermal conductivities of anisotropic composites

Adsorption of proteins on membrane surfaces plays an important role in cell biological processes. In this work, we develop a two-dimensional fluid model for proteins. The protein molecules have been modeled as two-dimensional convex and soft particles. The Lennard-Jones potential for circular particles and Kihara (12,6) potential for elliptical particles with hard core have been used to model pairwise intermolecular interactions. The equation of state of the fluid model has been derived using Weeks-Chandler-Andersen decomposition and it involves three parameters, an attraction, a repulsion, and a size parameter, which depend on the shape and core size of the molecules. For validation of the model, a two-dimensional molecular dynamics simulation has been performed. Finally, the model has been applied to study the adsorption of proteins on a flat membrane. In comparison with the existing model of hard and convex particles for protein adsorption, our model predicts a higher packing fraction for the adsorption equilibria. Although the present work is based on Lennard-Jones-type interaction, it can be extended for other specific soft interactions between convex molecules. Thus the model has general applicability for any other two-dimensional adsorption systems of molecules with soft interaction. © 2014 American Physical Society.

Physical Review E - Statistical, Nonlinear, and Soft Matter Physics

Two-dimensional convex-molecule fluid model for surface adsorption of proteins: Effect of soft interaction on adsorption equilibria

Clay deposits often exhibit inherent anisotropy due to different microfabrics, resulting from both environmental conditions during deposition and stress conditions subsequently. Many anisotropic elastic-plastic models are developed for modeling the behavior of clays subjected to anisotropic stress conditions. In this study, the drained and undrained shearing behavior of kaolinite clay samples with different microfabrics are modeled using anisotropic S-CLAY1 model with a rotational hardening rule and the isotropic modified cam clay (MCC) model. The inherent anisotropy resulting from the difference in the microfabric of the clay samples, reflected as the initial value of the rotational hardening parameter of the S-CLAY1 model, is determined based on the shape of the undrained stress paths of the samples subjected to consolidated undrained triaxial tests. The simulated results are compared with the results of consolidated undrained and drained triaxial tests carried out on kaolinite samples with different microfabrics. Clay samples with different microfabrics are prepared artificially, in the laboratory, by remolding with different pore fluids. It is observed that while S-CLAY1 model predicts the undrained behavior of kaolinite samples better, the drained behavior is better predicted by the MCC model. © 2014 W. S. Maney & Son Ltd

Department of Civil Engineering

International Journal of Geotechnical Engineering

Undrained and drained shearing behavior of kaolinite with different microfabrics

In this article, we study the problem of how to maximize the throughput of a periodic real-time system under a given peak temperature constraint.We assume that different tasks in our system may have different power and thermal characteristics. Two scheduling approaches are presented. The first is built upon processors that can be in either active or sleep mode. By judiciously selecting tasks with different thermal characteristics as well as alternating the processor's active/sleep mode, the sleep period required to cool down the processor is kept at aminimum level, and, as the result, the throughput ismaximized.We further extend this approach for processors with dynamic voltage/frequency scaling (DVFS) capability. Our experiments on a large number of synthetic test cases as well as real benchmark programs show that the proposed methods not only consistently outperform the existing approaches in terms of throughput maximization, but also significantly improve the feasibility of tasks when a more stringent temperature constraint is imposed. © 2014 ACM.

Department of Computer Science and Engineering

Transactions on Embedded Computing Systems

Throughput maximization for periodic real-time systems under the maximal temperature constraint

The pressure grouting of drilled shaft tips has become popular worldwide due to its effectiveness in mobilizing a larger portion of the available tip resistance under service displacements. This paper presents experimental and numerical studies on the load transfer mechanism and factors controlling the axial response of base grouted drilled shafts in cohesionless soils. The study found that the increased axial capacity of grout-tipped drilled shafts under service loads and displacements depended mainly on preloading effects and the increased tip area provided by the grouting process. A simple prediction approach for estimating the tip capacity of grouted shafts utilizing cone penetration resistance was suggested based on the results of the study. The validity of the proposed approach was verified by the analysis of full-scale case studies of grouted shafts reported in the literature. © 2013 Springer-Verlag Berlin Heidelberg.

Acta Geotechnica

Experimental study, numerical modeling of and axial prediction approach to base grouted drilled shafts in cohesionless soils

This study addresses the dynamic modelling and indirect disturbance compensation control of planar parallel robotic motion platform with three degrees of freedom (3-DOF) in the presence of parameter uncertainties and external disturbances. The proposed planar parallel motion platform is a singularity free manipulator and has three manipulator legs located on the same plane linked with a moving platform. Of the three aforementioned manipulator legs, two legs have a prismatic-revolute-prismatic (PRP) joint configuration each with only one prismatic joint deliberated to be active, and the other leg consists of prismatic-revolute-prismatic (PPR) joint configuration with one active prismatic joint. The closed form kinematic solution (both forward and reverse kinematics) for the platform has been obtained in completion. In addition, the dynamic model for the platform has been communicated using the energy based Euler-Lagrangian formulation method. The proposed controller is based on a computer torque control with disturbance compensation integrated with it. Disturbance vectors comprising disturbances due to parameter variations, payload variations, frictional effects and other additional effects have been estimated using an extended Kalman filter (EKF). The EKF proposed for this specific platform uses only position and orientation measurements for estimation and noise mitigation. Simulations with a characteristic trajectory are presented and the results have been paralleled with traditional controllers such as the proportional integral derivative (PID) controller and computed torque controller (CTC). The results demonstrate satisfactory tracking performance for the proposed controller in the presence of parameter uncertainties and external disturbances. © 2014 Elsevier Ltd.

Robotics and Computer-Integrated Manufacturing

Indirect disturbance compensation control of a planar parallel (2-PRP and 1-PPR) robotic manipulator

The importance of fineness ratio in determining the aerodynamic shapes of minimum-drag, zero-lift axisymmetric bodies in inviscid hypersonic flows is investigated using a shape optimization framework. The framework employs modified Newtonian theory for surface pressure computation, Bezier curves for geometric parameterization and a steepest-descent approach for minimization of the wave-drag coefficient. Studies are performed on axisymmetric bodies of a given length for fineness ratios varying from 1 to 6 and Mach numbers ranging from 6 to 12. It is shown that the optimal axisymmetric body for a given freestream Mach number is blunt-nosed for smaller fineness ratios but becomes sharp-nosed at larger fineness ratios. The fineness ratio at which the optimal body of revolution transitions from blunt-nosed to sharp-nosed is found to be nearly constant at hypersonic speeds and is around 3. Results indicate that the optimal bodies derived from the framework are superior in terms of wave drag to the von Kármán ogive but comparable to the 0.7 power-law body. High-resolution Euler simulations of these optimal forebodies demonstrate that, while the modified Newtonian theory underpredicts the wave drag for lower values of the similarity parameter, the derived configurations remain "near-optimal" for the entire range of the similarity parameter in the hypersonic regime. The study hints at the possibility of multiple near-optimal configurations in inviscid hypersonic flows and affirms the utility of the present framework as a low-fidelity approach for the design of minimum-drag configurations. Copyright © 2013 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

Journal of Spacecraft and Rockets

Effect of fineness ratio on minimum-drag shapes in hypersonic flows

The reaction of metal carbonyl compounds with group 6 and 8 metallaboranes led us to report the synthesis and structural characterization of several novel mixed-metal chalcogenide tetrahedral clusters. Thermolysis of arachno-[(Cp∗RuCO)2B2H6], 1 and [Os3(CO)12] in the presence of 2-methylthiophene yielded [Cp∗Ru(CO)2(μ-H){Os3(CO)9}S], 3 and [Cp∗Ru(μ-H){Os3(CO)11}], 4. In a similar fashion, the reaction of [(Cp∗Mo)2B5H9], 2, with [Ru3(CO)12] and 2-methylthiophene yielded [Cp∗Ru(CO)2(μ-H){Ru3(CO)9}S], 5 and conjuncto-[(Cp∗Mo)2B5H8(μ-H){Ru3(CO)9}S], 6. Both compounds 3 and 5 can be described as 50-cve (cluster valence electron) mixed-metal chalcogenide clusters, in which a sulfur atom replaces one of the vertices of the tetrahedral core. Compounds 3 and 5 possess a [M3S] tetrahedral core, in which the sulfur is attached to an exo-metal fragment, unique in the [M3S] metal chalcogenide tetrahedral arrangements. All the compounds have been characterized by mass spectrometry, IR and 1H, 11B and 13C NMR spectroscopy in solution and the solid state structures were unequivocally established by crystallographic analysis of compounds 3, 5 and 6. © 2014 the Partner Organisations.