Browsing by Author "Patel, M."

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The effect of the particle shape and strain rate on microstructure and compressive deformation response of pure Ti-foam made using acrowax as space holder
(2015) Mondal, D.P.; Patel, M.; Jain, H.; Jha, A.K.; Das, S.; Dasgupta, R.
Titanium foams of varying amount of porosities have been made using acrowax bits as a space holder through powder metallurgy route. Two types of Ti-particles were used: (i) angular and (ii) spherical in order to see the effect of particle shape on microstructure and deformation behavior. The compressive deformation behavior of Ti-foams with varying porosities and type of particles are studied under different strain rates. It is observed that the microstructural characteristics of Ti-foam varied marginally with the shape of Ti-particles. But the shape of particles influenced reasonably the deformation responses of Ti-foam. The plateau stress, modulus and energy absorption follow power law with relative density irrespective of shape of Ti-particles. All these parameters in Ti-foams are almost invariant to the strain rate. The empirical constants associated with different empirically developed power law relations are different for different shape of Ti-particles. 2014 Elsevier B.V.
Metallic nanosponges for energy storage and conversion applications
(Royal Society of Chemistry, 2022) Hemanth, N.R.; Mohili, R.; Patel, M.; Jadhav, A.H.; Lee, K.; Chaudhari, N.K.
In order to meet the current energy storage demands, the rational design of novel nanostructured materials is crucial for the improvement of electrochemical storage and conversion performance. Nanostructured materials have shown promising results in various energy harvesting systems, owing to their multifunctional properties such as a large active surface area, mechanical strength, catalytic ability, excellent ion diffusion, and electronic conductivity. To date, the library of nanostructured materials consists of diverse compositions ranging from oxides, dichalcogenides, carbides to graphene-based and lithium alloys with various morphologies such as zero-dimensional (0D), 1D, 2D and 3D nanomaterials. In particular, nanosponges have exhibited unusual three-dimensional architecture that provides rich surface defects and excellent structural stability resulting in improved catalytic activity. Additionally, the large conducting surface, electronic conductivity and pronounced crystalline phase stability of nanosponges have been utilized to improve the electrode performance drastically. Moreover, the unique sponge-like metallic porous network not only reduces the overall weight of the device but also decreases the consumption of metal usage. In this context, this review particularly highlights the recent progress in the synthesis and properties of noble metals and other metal-based sulphide, oxide, hydroxide and phosphide nanosponges, and their application in electrochemical storage and conversion devices. © 2022 The Royal Society of Chemistry.
MXenes: promising 2D memristor materials for neuromorphic computing components
(Cell Press, 2022) Patel, M.; Hemanth, N.R.; Gosai, J.; Mohili, R.; Solanki, A.; Roy, M.; Fang, B.; Chaudhari, N.K.
Brain-inspired parallel computing ‘neuromorphic computing’ is one of the most promising technologies for efficiently handling large amounts of information data, which operates based on a hardware-neural network platform consisting of numerous artificial synapses and neurons. Memristors, as artificial synapses based on various 2D materials for neuromorphic and data storage technologies with low power consumption, high scalability, and high speed, have been developed to address the von Neumann bottleneck and limitations of Moore's law. The 2D MXenes have strong potential application in memristors due to their ultrahigh conductivity, fast charge response, high stacking density, and high hydrophilicity. Here, we discuss how MXenes are emerging as a potential material towards artificial synapses. Recent progress in research on artificial synapses, fabricated particularly using MXenes and their composite materials, is comprehensively discussed with respect to mechanism, synaptic characteristics, power efficiency, and scalability. Finally, we present an outlook of the future development of MXenes for artificial intelligence and challenges in integrating memristors with MXenes are briefly discussed. © 2022 Elsevier Inc.
Seismic response of basal geogrid reinforced embankments supported over floating and end bearing piles
(CRC Press/Balkema, 2019) Radhika, M.; Patel, M.; Jayalekshmi, B.R.; Shivashankar, R.
Embankments, roads and bridges are very important components of infrastructure. It is equally important that these structures are also able to resist earthquake forces and be functional at all times. Since the bridge rests on rigid deep foundations and the approaching embankments to the bridge on both sides could be resting on weak and compressible soil, the bridge and embankment junction always experiences differential settlement problems. To overcome these settlements, construction of approach embankments supported by pile foundations with basal geogrid reinforcement is a viable solution. Lot of studies are available in literature on the analysis of these geogrid reinforced pile supported embankments subjected to static loading conditions. Very few studies are available on geogrid reinforced pile supported embankments (GRPEâ€™s) subjected to seismic excitations. Hence in the present study, 3-dimensional finite element analysis of 3 m high embankment made of pulverized fuel ash having crest width of 20 m and side slope of 1V:1.5H resting on 28 m thick soft marine clay subjected to seismic loading is considered. The soft marine clay is provided with 300 mm diameter RC piles having 22 m, 24 m, 26 m(Floating piles) and 28 m (End bearing piles) lengths arranged in a square grid pattern with centre to centre spacing of three times the diameter of the pile. Geogrid with tensile modulus of 2500 kN/m is considered as basal reinforcement. Maximum vertical and horizontal displacements along the embankment, settlement reduction ratio, differential settlements at crest, vertical and horizontal displacements at toe are evaluated. The embankment resting over end bearing pile stabilized soft marine clay experiences less settlements, less toe horizontal displacements, less differential settlements, larger settlement reduction ratio than the embankment resting over floating pile stabilized soft marine clay. Â© 2019 Associazione Geotecnica Italiana, Rome, Italy.
SUPER-NATURALINSTRUCTIONS: Generalization via Declarative Instructions on 1600+ NLP Tasks
(Association for Computational Linguistics (ACL), 2022) Wang, Y.; Mishra, S.; Alipoormolabashi, P.; Kordi, Y.; Mirzaei, A.; Arunkumar, A.; Ashok, A.; Dhanasekaran, A.S.; Naik, A.; Stap, D.; Pathak, E.; Karamanolakis, G.; Lai, H.G.; Purohit, I.; Mondal, I.; Anderson, J.; Kuznia, K.; Doshi, K.; Patel, M.; Pal, K.K.; Moradshahi, M.; Parmar, M.; Purohit, M.; Varshney, N.; Kaza, P.R.; Verma, P.; Puri, R.S.; Karia, R.; Sampat, S.K.; Doshi, S.; Mishra, S.; Reddy, S.; Patro, S.; Dixit, T.; Shen, X.; Baral, C.; Choi, Y.; Smith, N.A.; Hajishirzi, H.; Khashabi, D.
How well can NLP models generalize to a variety of unseen tasks when provided with task instructions? To address this question, we first introduce SUPER-NATURALINSTRUCTIONS, a benchmark of 1, 616 diverse NLP tasks and their expert-written instructions. Our collection covers 76 distinct task types, including but not limited to classification, extraction, infilling, sequence tagging, text rewriting, and text composition. This large and diverse collection of tasks enables rigorous benchmarking of cross-task generalization under instructions-training models to follow instructions on a subset of tasks and evaluating them on the remaining unseen ones. Furthermore, we build Tk-INSTRUCT, a transformer model trained to follow a variety of in-context instructions (plain language task definitions or k-shot examples). Our experiments show that Tk-INSTRUCT outperforms existing instruction-following models such as InstructGPT by over 9% on our benchmark despite being an order of magnitude smaller. We further analyze generalization as a function of various scaling parameters, such as the number of observed tasks, the number of instances per task, and model sizes. We hope our dataset and model facilitate future progress towards more general-purpose NLP models. Â© 2022 Association for Computational Linguistics.
The effect of the particle shape and strain rate on microstructure and compressive deformation response of pure Ti-foam made using acrowax as space holder
(Elsevier Ltd, 2015) Mondal, D.P.; Patel, M.; Jain, H.; Jha, A.K.; Das, S.; Dasgupta, R.
Titanium foams of varying amount of porosities have been made using acrowax bits as a space holder through powder metallurgy route. Two types of Ti-particles were used: (i) angular and (ii) spherical in order to see the effect of particle shape on microstructure and deformation behavior. The compressive deformation behavior of Ti-foams with varying porosities and type of particles are studied under different strain rates. It is observed that the microstructural characteristics of Ti-foam varied marginally with the shape of Ti-particles. But the shape of particles influenced reasonably the deformation responses of Ti-foam. The plateau stress, modulus and energy absorption follow power law with relative density irrespective of shape of Ti-particles. All these parameters in Ti-foams are almost invariant to the strain rate. The empirical constants associated with different empirically developed power law relations are different for different shape of Ti-particles. © 2014 Elsevier B.V.
Titanium foam with coarser cell size and wide range of porosity using different types of evaporative space holders through powder metallurgy route
(2014) Mondal, D.P.; Patel, M.; Das, S.; Jha, A.K.; Jain, H.; Gupta, G.; Arya, S.B.
Ti-foams were made using different evaporative types of space holders such as acrowax and ammonium bicarbonate with a wide range of porosities (55-89%) through powder metallurgy technique. Cold compaction pressure was varied from 100 to 200. MPa in order to examine the effect of cold compaction pressures on the absolute porosities of the foams. The cell size, cell wall thickness and porosities of the foams were characterised as a function of cold compaction pressures and type of space holders. Empirical correlation has been established to predict foam porosities from compaction pressures and volume fraction of space holder. The sintered foams were found to be free from residue of the space holder. However, approximate 8-10% of titanium oxidized during sintering. The foam made with acrowax, as space holder attains slightly higher strength, modulus and energy absorption. � 2014 Elsevier Ltd.
Titanium foam with coarser cell size and wide range of porosity using different types of evaporative space holders through powder metallurgy route
(Elsevier Ltd, 2014) Mondal, D.P.; Patel, M.; Das, S.; Jha, A.K.; Jain, H.; Gupta, G.; Arya, S.B.
Ti-foams were made using different evaporative types of space holders such as acrowax and ammonium bicarbonate with a wide range of porosities (55-89%) through powder metallurgy technique. Cold compaction pressure was varied from 100 to 200. MPa in order to examine the effect of cold compaction pressures on the absolute porosities of the foams. The cell size, cell wall thickness and porosities of the foams were characterised as a function of cold compaction pressures and type of space holders. Empirical correlation has been established to predict foam porosities from compaction pressures and volume fraction of space holder. The sintered foams were found to be free from residue of the space holder. However, approximate 8-10% of titanium oxidized during sintering. The foam made with acrowax, as space holder attains slightly higher strength, modulus and energy absorption. © 2014 Elsevier Ltd.