3,763 research outputs found
I Was Addicted to Sex With Married Women
No full textAs a young man, Akhil Sharma revelled in the most dangerous of liaisons, having sex with other men's wives – until the thrill began to pall
Maldives Resorts: Eco-Friendly Vacations
No full textLuxurious, exclusive and remote, the Maldives are the ultimate beach escape. They’re also a case study in the risks of global warming. Writer Akhil Sharma visits the country’s most eco-friendly resorts and discovers a remarkable cuisine worth protecting
Recollections of a Hindu Hedonist
No full textNovelist Akhil Sharma grew up in a teetotaling Indian household. Here, he tells how discovering a passion for great wine helped him create a new identity out of a painful past
Establishing a consensus for the diagnosis and treatment of Demodex blepharitis
No full textAs part of our research spotlight series, which aims to highlight interesting pieces of optometry related research, Drs Nikhil Sharma and Eilidh Martin describe findings from a recently published Delphi study which sought to establish consensus on best practice for the diagnosis and treatment of Demodex blepharitis
Interview with Lakshmi Raj Sharma, Author of The Tailor’s Needle
No full textInterview with Indian writer Lakshmi Raj Sharma, author of 'The Tailor's needle
Detection results of NMC particles in composite battery cathodes
No full textThis dataset shows more examples of the NMC particles detection overlayed with the original images in composite battery cathodes.
@journal{li2022networkevolution,
title={Dynamics of particle network in composite battery cathodes},
author={Li, Jizhou and Sharma, Nikhil and Jiang, Zhisen and Yang, Yang and Monaco, Federico and Xu, Zhengrui and Hou, Dong and Ratner, Daniel and Pianetta, Piero and Cloetens, Peter and Lin, Feng and Zhao, Kejie and Liu, Yijin},
year={2022},
journal={Science}
Dynamics of particle network in composite battery cathodes
No full textThis repository contains the source codes for the study of active particle-network evolution in Ni-rich LiNi0.8Mn0.1Co0.1O2 (NMC) composite battery cathodes, as described in the following paper:
@journal{li2021networkevolution,
title={Dynamics of particle network in composite battery cathodes},
author={Li, Jizhou and Sharma, Nikhil and Jiang, Zhisen and Yang, Yang and Monaco, Federico and Xu, Zhengrui and Hou, Dong and Ratner, Daniel and Pianetta, Piero and Cloetens, Peter and Lin, Feng and Zhao, Kejie and Liu, Yijin},
year={2022},
journal={Science}
A Decomposition Approach to the Weighted k-Server Problem
No full textA natural variant of the classical online k-server problem is the weighted k-server problem, where the cost of moving a server is its weight times the distance through which it moves. Despite its apparent simplicity, the weighted k-server problem is extremely poorly understood. Specifically, even on uniform metric spaces, finding the optimum competitive ratio of randomized algorithms remains an open problem - the best upper bound known is 2^{2^{k+O(1)}} due to a deterministic algorithm (Bansal et al., 2018), and the best lower bound known is Ω(2^k) (Ayyadevara and Chiplunkar, 2021).
With the aim of closing this exponential gap between the upper and lower bounds, we propose a decomposition approach for designing a randomized algorithm for weighted k-server on uniform metrics. Our first contribution includes two relaxed versions of the problem and a technique to obtain an algorithm for weighted k-server from algorithms for the two relaxed versions. Specifically, we prove that if there exists an α₁-competitive algorithm for one version (which we call Weighted k-Server - Service Pattern Construction) and there exists an α₂-competitive algorithm for the other version (which we call Weighted k-server - Revealed Service Pattern), then there exists an (α₁α₂)-competitive algorithm for weighted k-server on uniform metric spaces. Our second contribution is a 2^O(k²)-competitive randomized algorithm for Weighted k-server - Revealed Service Pattern. As a consequence, the task of designing a 2^poly(k)-competitive randomized algorithm for weighted k-server on uniform metrics reduces to designing a 2^poly(k)-competitive randomized algorithm for Weighted k-Server - Service Pattern Construction. Finally, we also prove that the Ω(2^k) lower bound for weighted k-server, in fact, holds for Weighted k-server - Revealed Service Pattern
sj-pdf-1-ajs-10.1177_03635465231180323 – Supplemental material for Efficacy and Safety of Stempeucel in Osteoarthritis of the Knee
No full textSupplemental material, sj-pdf-1-ajs-10.1177_03635465231180323 for Efficacy and Safety of Stempeucel in Osteoarthritis of the Knee by Pawan Kumar Gupta, Sunil Maheshwari, Joe Joseph Cherian, Vijay Goni, Arun Kumar Sharma, Sujith Kumar Tripathy, Keerthi Talari, Vivek Pandey, Parag Kantilal Sancheti, Saurabh Singh, Syamasis Bandyopadhyay, Naresh Shetty, Surendra Umesh Kamath, Purohit Sharad Prahaldbhai, Jijy Abraham, Suresh Kannan, Samatha Bhat, Shivashankar Parshuram, Vinayaka Shahavi, Akhilesh Sharma, Nikhil N. Verma and Uday Kumar in The American Journal of Sports Medicine</p
Modified Epoxy Coatings for Corrosion Inhibition in Reinforcing Bars in Concrete
No full textCorrosion of reinforced concrete structures is one of the biggest problems faced by the construction industry with billions of dollars spent annually on corrosion control and mitigation. Epoxy Coated Rebars (ECRs) have been reported to effectively mitigate corrosion in concrete structures. However, their utilization is constrained by the presence of micro-pores and the inherent brittleness of epoxy coatings. This study delves into the mechanisms of corrosion inhibition through the application of nano-modified epoxy-based coatings. Three distinct formulations of modified epoxy-based coatings were precisely evaluated: nano-clay-modified epoxy coatings with polyaniline, graphene-derivatives modified epoxy coatings with carbon nanotubes and self-healing tung-oil microcapsules-based nano-modified epoxy coatings for plain bars directly and when they were further embedded in concrete and exposed to accelerated chloride corrosion. A multifaceted evaluation approach of Non-Destructive Testing (NDT) and Destructive testing techniques were employed to ascertain coating corrosion efficacy comprehensively. NDT monitoring comprises of visual inspection, corrosion current measurements and ultrasonic guided waves monitoring techniques whereas destructive testing techniques involved evaluation of loss in mass, tensile strength and pull-out strength vis-à-vis corrosion exposure.
Nano-clay modified epoxy coatings examines the efficacy of nano-modified epoxy coatings using four different silane-treated nano-clays (Montmorillonite-MMT, Organic Montmorillonite-OMMT (Cloisite®15A and Cloisite®30B) and Halloysite-HNT) in a combination with polyaniline (PANI). PANI being good pigment material for anti-corrosion coatings is expected to provide enhanced corrosion resistance due to its unique ability to intercept electrons from the metal surface and transfer them to outside the coating. It was confirmed that nano-clay modified epoxy coatings showed superior performance in comparison with pure epoxy coatings, as a result of enhanced barrier properties by nano-clay and synergetic effect of polyaniline fragments closely stacked with nano-sized nano-clay platelets throughout the coating. Delay in corrosion initiation in pure epoxy is 7-8 days in comparison to 70-75 days for PANI with Cloisite®30B nano-clay. Further, ultrasonic guided waves transmitted signals dropped to zero for PE samples in 40 days whereas in PANI with Cloisite®30B after 90 days of exposure ultrasonic signals fall by only 10%. Notably, formulations featuring Cloisite®30B nano-clay with PANI showcased superior barrier properties, with the intercalation of nano-clay particles facilitating tortuous diffusion pathways, thereby impeding aggressive ion ingress and corrosion propagation. Additionally, hydroxyl group of Cloisite®30B promotes interfacial interaction between nano-clay and polymer matrix resulting in impermeable network. Characterization results of silane-treated clays demonstrated the successful grafting of the silane agent on the nano-clay structure, while FE-SEM of different coatings displays the dispersion of nano-fillers inside the coating matrix.
Incorporation of graphene-derivatives in the form of graphene oxide (GO) and reduced graphene oxide (rGO) with carbon nanotubes (CNT) and silane agents was studied further for improved ductility and corrosion inhibition properties. Hybrid mixture of CNTs and rGO/GO enhances the mechanical strength of the coating matrix whereas silane agents improve dispersion and bonding characteristics of nano-fillers. The corrosion initiates earlier in rGO/CNT coatings, occurring within 50 days, while no corrosion was observed in GO/CNT coatings even after 150 days of exposure to corrosion. Additionally, in ultrasonic guided wave monitoring, transmitted signals dropped to zero for rGO/CNT samples in 125 days whereas in GO/CNT coatings after 150 days of exposure ultrasonic signals are completely healthy. GO exhibited superior corrosion inhibition performance over rGO, due to its successful blocking of aggressive larger chloride ions, by providing a dense impenetrable network due to the presence of functional groups on basal planes of GO sheets.
Further the nano-clay and graphene derivatives-based coatings were further examined with self-healing tung-oil microcapsules to develop smart self-healing coatings. In smart nano-clay modified epoxy coating studies, Cloisite®15A nano-clay were incorporated with tung-oil microcapsules in epoxy coatings (MNC) and compared with pure epoxy. These coatings were pre-damaged to investigate the self-healing capabilities of coatings. Corrosion initiates in 15–17 days for NC coatings (only nano-clay) and 8–10 days for MC coatings (only tung-oil microencapsulated epoxy coating), whereas it initiates in 30–35 days with MNC coatings. Synergetic effect of nano-filler with self-healing microcapsules enhanced the overall performance of epoxy coatings. Smart graphene-derivatives (GO and rGO) modified epoxy coating was also studied with tung-oil microcapsules (MrGO and MGO). A dual layer coating combination (M+GO) with additional dual coating of MC coating as top layer and GO/CNT coating as base layer was also investigated. All three coatings exhibit encouraging outcomes after 160 days of accelerated corrosion exposure; however, in the case of the M+GO coatings, there is no corrosion initiation at all after 160 days. Smart coatings formulations exhibited pronounced self-healing attributes, facilitated by tung-oil polymerization triggered upon by coating damage or corrosion initiation. By using tung-oil in nano-modified epoxy coatings, significant reductions in mass loss alongside, noteworthy enhancements in residual tensile strength vis-à-vis pure epoxy coatings, with negligible compromise on bond strength was observed.
In essence, this research effort brings out the pivotal role of advanced nano-modified epoxy coatings in mitigating corrosion-induced structural degradation, thereby bolstering infrastructure resilience and longevity. The understanding obtained from this research offers invaluable insights into the development of robust, cost-effective, and environmentally sustainable corrosion mitigation strategies, vital for fostering resilient infrastructure in the face of evolving challenges
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