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 present study investigates numerically the conjugate heat transfer in a two-dimensional planar sudden expansion flow. The governing equations are solved using an unstructured solver based on the finite volume method. The results show the effects of Reynolds number, thermal conductivity ratio, Prandtl number and solid slab thickness on the conjugate heat transfer characteristics. The outcome of this study is presented in the form of local Nusselt number, average Nusselt number and interface temperature along the solid-fluid interface. It is observed that for the given range of Reynolds number, i.e. Re ≤ 100 , the fluid flow is found to be symmetric. It is further revealed that the heat transfer increases along the interface with the increase of Reynolds number, thermal conductivity ratio and Prandtl number whereas it decreases with the increase of solid slab thickness. © 2021, The Institution of Engineers (India).

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Department of Mechanical Engineering

Journal of The Institution of Engineers (India): Series C

Numerical Analysis of Conjugate Heat Transfer in a Planar Sudden Expansion Flow

The present study investigated the influence of biochar on various geotechnical properties of clayey soil. Biochar, a carbon-rich product, was amended with the soil at different percentages such as 5, 10 and 15%. Laboratory tests were conducted to evaluate the feasibility of utilization of biochar in enhancing the integrity of soil slopes with an emphasis on landfill covers and bioengineered slopes. Scanning electron microscopy (SEM) tests were conducted to analyse micro-porous structure of biochar and soil-biochar mix. The SEM micrographs indicated the porous structure of the biochar and a good interaction with the clay particles. It was concluded from the present study that the biochar amended soil can have steeper and stable slopes compared to soil without biochar amendments. The compressibility of the soil was also decreased with biochar amendment. © 2021, Springer Nature Singapore Pte Ltd.

Department of Civil Engineering

Problematic Soils and Geoenvironmental Concerns

Influence of Biochar on Geotechnical Properties of Clayey Soil: From the Perspective of Landfill Caps and Bioengineered Slopes

Back-to-Back Mechanically Stabilized Earth (MSE) walls have become an integral part of the transportation infrastructures, especially as ramps, bridge approaches, etc. The permeability, strength and constructability attributes of well-graded granular soils have rendered them as the most suitable fill material for MSE walls. However, the scarcity of such good materials compels the usage of locally available soil with high fine content (marginal fill) having low permeability and high plasticity characteristics, which can cause excessive wall deformation or even failure, if not adequately designed and constructed. This study focused on the assessment of overall performance of back-to-back MSE walls with a trapezoidal marginal fill zone surrounded by a near-optimal amount of select fill (i.e., hybrid-fill) as an alternative to the wall with select fill only. The behaviour of hybrid-fill wall at the end of construction and during heavy rainfall infiltration were investigated through finite element modelling and compared with fully select fill and fully marginal fill walls. The study revealed that the overall performance (i.e., horizontal and vertical deformations, reinforcement tension, and factor of safety) of the hybrid-fill wall with 31–47% select fill is much better than that of fully marginal fill wall, especially during the extreme rainfall infiltration scenario. The response of this hybrid configuration is even comparable with that of fully select fill wall, suggesting the proposed hybrid-fill wall as a stable as well as cost-efficient alternative system in locations where sufficient quantity of well-graded soil is not readily available. © 2020 Elsevier Ltd

Transportation Geotechnics

Numerical evaluation of the performance of back-to-back MSE walls with hybrid select-marginal fill zones

Vast deposits of high water content soft clays pose severe problems and are not suitable for construction of engineering projects due to their inadequate bearing capacity and inherent large swelling and shrinkage ability. Deep soil mixing (DSM) is one of the widely accepted methods for improving soft soil properties like increase in bearing capacity and reduction in settlement that are of utmost importance for the construction of any structure. In this study, ground granulated blast furnace slag (GGBS)-based geopolymer was used to investigate its efficiency as a sustainable replacement to cement for DSM applications, thereby reducing the carbon footprint. A total of 27 GGBS-geopolymer mixes and 9 cement-treated reference mixes were cast and tested for strength and durability characteristics. The variables of the study include binder content (10, 20, and 30%), activator/binder ratio (0.5, 0.75, and 1.0), and initial soil moisture content (0.75wL, wL, 1.25wL). Different tests were conducted to explore the properties of stabilised clays, such as unconfined compressive strength, flexural strength, and durability against wetting drying cycles. To meet the requirements of DSM application, binder dosage greater than 10% and A/B ratio greater than 0.5 were recommended. With an increase in initial soil moisture content, the strength of the treated specimens under unconfined compression and flexure reduced and thus increased binder dosage helps to meet the DSM requirements for high water content soils. From the present study, it can be concluded that using slag-geopolymer binder for stabilising soft soil is an effective and sustainable alternative to cement in DSM applications. © 2020, Springer Nature Switzerland AG.

Innovative Infrastructure Solutions

Experimental evaluation of strength and durability characteristics of geopolymer stabilised soft soil for deep mixing applications

Rapid device aging in the nano era threatens system lifetime reliability, posing a major intrinsic threat to system functionality. Traditional techniques to overcome the aging-induced device slowdown, such as guardbanding are static and incur performance, power, and area penalties. In a manycore processor, the system-level design abstraction offers dynamic opportunities through the control of task-to-core mappings and per-core operation frequency towards more balanced core aging profile across the chip, optimizing the system lifetime reliability while meeting the application performance requirements. This article presents Longevity Framework (LF) that leverages online integrated aging-aware hierarchical mapping and voltage frequency (VF)-selection for lifetime reliability optimization in manycore processors. The mapping exploration is hierarchical to achieve scalability. The VF-selection builds on the trade-offs involved between power, performance, and aging as the VF is scaled while leveraging the per-core DVFS capabilities. The methodology takes the chip-wide process variation into account. Extensive experimentation, comparing the proposed approach with two state-of-the-art methods, for 64-core and 256-core systems running applications from PARSEC and SPLASH-2 benchmark suites, show an improvement of up to 3.2 years in the system lifetime reliability and 4× improvement in the average core health. © 2020 IEEE.

Department of Computer Science and Engineering

IEEE Transactions on Computers

Longevity Framework: Leveraging Online Integrated Aging-Aware Hierarchical Mapping and VF-Selection for Lifetime Reliability Optimization in Manycore Processors

We have reported experimental studies on the self-assembly and degree of ordering of a binary mixture of soft colloids in monolayer deposits obtained by controlled evaporation. A sessile drop containing soft colloids is evaporated on a solid surface to achieve a loosely-packed two-dimensional deposit with a hexagonal arrangement. The soft microgel particles possess a hard core with a compliant corona, which plays a crucial role in retaining the crystallinity of the binary particle monolayer. The ordered arrangement of the binary mixture is observed even when the bulk diameter of one type of particle is 25% higher than the other, irrespective of their mixing ratio (1 : 3, 1 : 1, and 3 : 1). The microgel particles of both sizes are found to be homogeneously distributed throughout the deposit, completely suppressing the size-dependent particle segregation. Furthermore, in contrast to the self-assembly of bidisperse hard colloids, wherein the lattice distorts to accommodate particles of disparate sizes, in soft colloids, the particles deform at the interface to preserve the crystalline lattice. Moreover, unlike the gradual order-to-disorder transition observed in the deposits consisting of monodisperse microgel particles, the deposits of a binary mixture of microgels exhibit no noticeable trend. The areal disorder parameter, pair correlation function and the shape factor which quantifies the local ordering of particles in the deposit indicate the absence of a distinct order-to-disorder transition for the binary mixtures. © the Owner Societies 2021.

Department of Physics

Physical Chemistry Chemical Physics

Evaporative self-assembly of the binary mixture of soft colloids

Studies on the characterization and performance of residual sugarcane bagasse ash (SCBA) obtained from high-temperature cogeneration boilers in concrete are highly limited. This study investigated the pretreatment process and optimization of SCBA collected from high-temperature boilers by various physicochemical methods. The effect of recalcination and grinding on the physical and mineralogical properties of SCBA were also examined. The percentage replacement of cement with SCBA was optimized using packing density and flow. The performance of optimized binder with combinations of cement and SCBA was validated through compressive strength of mortar specimens. From the results, it was observed that SCBA from high-temperature boilers can be used as a supplementary cementitious material with minimal processing efforts and a 15% level of replacement is suggested as the optimum level for SCBA-blended cement. Based on the investigation, a framework with a step-by-step procedure including pretreatment and optimization methods is suggested for the use of SCBA. © 2021 American Society of Civil Engineers.

Journal of Materials in Civil Engineering

Systematic Pretreatment Process and Optimization of Sugarcane Bagasse Ash Dosage for Use in Cement-Based Products

Department of Mathematics

arXiv e-prints, arXiv: 2104.

Hybrid and Generalized Bayesian Cramér-Rao Inequalities via Information Geometry

We extend projection theorems concerning Hellinger and Jones et al. divergences to the continuous case. These projection theorems reduce certain estimation problems on generalized exponential models to linear problems. We introduce the notion of regularity for generalized exponential models and show that the projection theorems in this case are similar to the ones in discrete and canonical case. We also apply these ideas to solve certain estimation problems concerning Student and Cauchy distributions.

Fulltext

Journal of Multivariate Analysis

Projection theorems and estimating equations for power-law models

Metal additive manufacturing (AM) is gaining momentum among modern manufacturing techniques due to its flexibility in fabricating complex shaped components with minimum scrap. However, the technology cannot be directly employed in producing parts on a larger scale because of the poor surface integrity and average mechanical properties. This highlights the importance of post processing AM components with suitable methods that can overcome these limitations. The existing finishing methods for AM components such as laser polishing, chemical polishing, abrasive finishing, mechanical polishing and other hybrid combinations have their own limitations. Difficulty in accessing complex part surfaces, loss of dimensional accuracy and deterioration in material surface and properties are some of the major challenges related to existing finishing methods. In the present work, wire electrical discharge polishing (WEDP) technique has been proposed in improving the surface integrity and mechanical properties of metal AM components. Experiments were carried out on selective laser melted (SLM) stainless steel (SS316 L) specimens at different settings of pulse duration and servo voltage. A detailed investigation into surface finish and morphology was performed to determine the enhancement in surface integrity after WEDP. In addition, investigations were conducted to evaluate the improvement in mechanical properties such as microhardness and tribological performance. The irregularities/defects over the SLM surface were removed and a maximum finish of 0.739 μm was achieved. A negligible amount of wire material was migrated to the SS316 L workpiece surface after WEDP process. Moreover, reduction in crystallite size and microstrain was obtained based on results from XRD analysis. Martensite formation and shift in peaks were also evident from XRD pattern after WEDP process. An increase in microhardness (∼ 317 HV) at the subsurface and reduction in coefficient of friction (∼ 0.35) were also achieved. Based on aforementioned results, WEDP showed excellent capability in improving the surface integrity and mechanical properties thereby providing a promising hybrid option for combining with metal AM technology. © 2020 Elsevier B.V.