Conference Papers
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506
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Item Eclipta prostrata leaf aqueous extract mediated for the synthesis of titanium dioxide nanoparticles and its larvicidal activity against malaria vector(2011) Govindasamy, G.; Rahuman, A.A.; Priyamvada, B.; Khanna, V.G.; Kumar, D.; Jose, P.J.Eco-friendly, nontoxic, inexpensive, abundantly available hitherto unreported Eclipta prostrata leaf extract is used for the biosynthesis of titanium dioxide nanoparticles (TiO 2 NPs). The TiO 2 NPs were characterized by FTIR, XRD, AFM and FESEM analysis. FTIR peak implicated the role of carboxyl group O-H stretching amine N-H stretch in the formation of TiO 2 NPs. XRD characterized in crystallographic plane of rutile phase. AFM showed uneven surface morphology which indicates the presence of both individual and agglomerated nanoparticles. FESEM analysis showed shape in spherical clusters, quite polydisperse and it ranges in size from 36-68 nm with calculated average size of 49.5 nm. In this paper, we have demonstrated a novel biological route for the synthesis of TiO 2 NPs and first report to assess the larvicidal activity against malaria vector. © 2011 IEEE.Item Quasi-based hierarchical clustering for land cover mapping using satellite images(Springer Verlag service@springer.de, 2013) Senthilnath, J.; Raj, A.; Omkar, S.N.; Mani, V.; Kumar, D.This paper presents an improved hierarchical clustering algorithm for land cover mapping problem using quasi-random distribution. Initially, Niche Particle Swarm Optimization (NPSO) with pseudo/quasi-random distribution is used for splitting the data into number of cluster centers by satisfying Bayesian Information Criteria (BIC).The main objective is to search and locate the best possible number of cluster and its centers. NPSO which highly depends on the initial distribution of particles in search space is not been exploited to its full potential. In this study, we have compared more uniformly distributed quasi-random with pseudo-random distribution with NPSO for splitting data set. Here to generate quasi-random distribution, Faure method has been used. Performance of previously proposed methods namely K-means, Mean Shift Clustering (MSC) and NPSO with pseudo-random is compared with the proposed approach-NPSO with quasi distribution(Faure).These algorithms are used on synthetic data set and multi-spectral satellite image (Landsat 7 thematic mapper). From the result obtained we conclude that use of quasi-random sequence with NPSO for hierarchical clustering algorithm results in a more accurate data classification. © 2013 Springer.Item Experimental analysis of cardanol biofuel as an alternative fuel for diesel engines with air-side oxygen enrichment(Trans Tech Publications Ltd ttp@transtec.ch, 2014) Dinesha, P.; Nayak, V.; Kumar, D.; Mohanan, P.The present study investigates the effect of air-side oxygen concentration enrichment on the performance and emission of a single cylinder diesel engine using a bio-fuel blend as fuel. In this study, a natural phenolic compound, namely, cardanol is selected as the bio-fuel, which is obtained from the shell of cashew nut after purification. A blend of B10M10 (10% cardanol +10% methanol + 80% diesel by volume) is prepared and tested in the engine at various loading conditions. The experiments are carried out at atmospheric oxygen condition and an increment of 3, 5, and 7% of atmospheric oxygen concentration by weight. There is a drastic reduction in HC, CO, and smoke except for NOx emission. The level of NOx emission increases as the oxygen concentration in the intake air is increased. The performance characteristic will increase as the oxygen concentration increases, and higher brake thermal efficiency is obtained for B10M10 at 7% oxygen concentration. B10M10 with 7% oxygen enrichment gives better results, similar to diesel, except for NOx emission. © (2014) Trans Tech Publications, Switzerland.Item Thermal and frictional performance evaluation of nano lubricant with multi wall carbon nano tubes (MWCNTs) as nano-additive(American Institute of Physics Inc. subs@aip.org, 2018) Lijesh, K.P.; Kumar, D.; Muzakkir, S.M.; Hirani, H.A Fluid Film Bearings (FFBs) operating in hydrodynamic boundary regime can provide moderate load carrying capacity, negligible wear and friction. However in extreme operating conditions i.e. at high load and low speed, asperities of journal and bearing surfaces come in contact with each other resulting in high wear and friction. During the contact of the asperities, the temperature of the lubricant increases due to frictional heating, resulting in reduction of the viscosity of lubricant. Variation of lubricant viscosity results in low load carrying capacity of the FFB and therefore resulting in detoriation of FFB performance. In the present work it is hypothesized that, by adding multi-functional Multi Wall Carbon Nano-Tubes (MWCNT) (having high thermal conductivity and anti-friction properties) as nano-additive in the base mineral oil, the aforementioned problems can be overcome. To validate the proposed hypothesis, five different samples of lubricant is considered: Sample 1: Base oil, Sample 2: Base oil +0.05% MWCNT, Sample 3: Base oil +0.05% MWCNT +0.5%surfactant, Sample 4: Base oil +0.1% MWCNT +0.5% surfactant, and Sample 5: Base oil +0.15% MWCNT +0.5%surfactant. To evaluate the performance of the developed lubricants, experiments were performed on the reduced scale conformal block on disc test setup. The experimental condition and dimension of the block and disc were decide for the Sommerfeld number equal to 0.0025, which indicates mixed lubrication regime. The performance of lubricant is evaluated by measuring the frictional force and temperature rise of the lubricant during the experiment. © 2018 Author(s).Item Enhancing tribological performance of Ti-6Al-4V using pin on disc setup(American Institute of Physics Inc. subs@aip.org, 2018) Kumar, D.; Lijesh, K.P.; Deepak, K.B.; Kumar, S.Titanium (Ti) alloy Ti-6Al-4V (Ti64), possesses a inimitable combination of mechanical, physical and corrosion properties, which makes them desirable for applications like aerospace, automobile, chemical and energy industries devices etc. However this alloy of Ti exhibits poor tribological (friction and wear) properties, which limits their full fledged implementation. However, the tribological behavior of T164 can be enhanced by providing a coating or a protective layer on it, which posses superior tribological properties. It is hypothesized that by a layer of alumina on the can be deposited on the surface of Ti64, by sliding them in dry-ambient condition using Pin On Disk (POD) machine. To validate the hypothesis, experiments were performed for different normal loading conditions of 13.7N, 68.7N and 109.9N at sliding speed of 0.01m/s and for a sliding distance of 1000m. The tribological performance of the experiments, were evaluated by measuring Coefficient of Friction (COF) and weight loss values. To understand the tribological mechanism and behaviour, In-situ analysis was performed on the pin using (i) Scanning Electron Microscopy (SEM) to understand the wear morphology, and (ii) Energy Dispersive Analysis of X Ray (EDAX) to estimate the deposition of alumina on surface of the pins. Based on the obtained results, the most favorable experimenting condition required for deposition of alumina over Ti64 will be identified. Finally, experiment on POD will be repeated for the selected experimenting condition and will be continued for the worst tribological condition. The obtained COF and wear values after performing the experiment will be presented. © 2018 Author(s).Item LBM combined with LM algorithm to estimate the unknown heat flux - A new inverse approach(Elsevier Ltd, 2019) Kumar, D.; Arumuga Perumal, D.A.; Gnanasekaran, N.; Kumar, M.K.The objective of the present work is the application of the Levenberg-Marquardt method as an inverse method for the estimation of the heat flux. In this paper inverse estimation of heat flux for a two-dimensional heat conduction problem is carried out. As a direct method, in the first attempt the solution of two-dimensional inverse heat conduction problem is formulated by using Lattice Boltzmann Method as a forward model. Later the solution to the problem is also obtained by using Finite Difference Method (FDM) as the forward model for the purpose of validation. Once the forward model is established, Levenberg-Marquardt Method is used as an inverse model to estimate the input parameter i.e. heat flux which is reported. A complete error analysis of inverse model with known values is performed. As the Lattice Boltzmann Method (LBM) is acclimatizing to parallel computation, its use is recommended in Levenberg-Marquardt method for the solution of inverse heat conduction problem which is evident from the results. © 2019 Elsevier Ltd.Item One Time Password (OTP) Life Cycle and Challenges: Case Study(Springer Science and Business Media Deutschland GmbH info@springer-sbm.com, 2021) Kumar, D.; Gautam, U.K.; Chandavarkar, B.R.In today’s world of the internet, we give priority to secure many of our accounts over this. It could be our social media profile, our cloud storage account, or anything; everything can be accessed only via a login interface. Traditional login systems follow a simple procedure of asking for username and password to authenticate the user. But due to the exponential development in the field of technology, this login interface is vulnerable to many attacks and thus compromising the user’s privacy and data. One more level has been added to the login interface known as OTP or One Time Password. The concept of OTP is that a randomly generated fixed digit code is sent to the user’s physical device if the entered password is correct. This way, we can be surer that only the appropriate user is accessing the system. This whole system combined known as 2-Factor authentication system. OTP is sent directly to the user’s accessible physical device only. It has many other applications like bank transactions, deletion of a social media account or cloud account, and many others. It’s because of the dynamic nature of OTP. This paper discusses the lifecycle of the OTP and its issues and challenges in the current world. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item The GEM Benchmark: Natural Language Generation, its Evaluation and Metrics(Association for Computational Linguistics (ACL), 2021) Gehrmann, S.; Adewumi, T.; Aggarwal, K.; Ammanamanchi, P.S.; Anuoluwapo, A.; Bosselut, A.; Chandu, K.R.; Clinciu, M.; Das, D.; Dhole, K.D.; Du, W.; Durmus, E.; Dušek, O.; Emezue, C.; Gangal, V.; Gârbacea, C.; Hashimoto, T.; Hou, Y.; Jernite, Y.; Jhamtani, H.; Ji, Y.; Jolly, S.; Kale, M.; Kumar, D.; Ladhak, F.; Madaan, A.; Maddela, M.; Mahajan, K.; Mahamood, S.; Majumder, B.P.; Martins, P.H.; McMillan-Major, A.; Mille, S.; van Miltenburg, E.; Nadeem, M.; Narayan, S.; Nikolaev, V.; Niyongabo, R.A.; Osei, S.; Parikh, A.; Perez-Beltrachini, L.; Rao, N.R.; Raunak, V.; Rodriguez, J.D.; Santhanam, S.; Sedoc, J.; Sellam, T.; Shaikh, S.; Shimorina, A.; Sobrevilla Cabezudo, M.A.S.; Strobelt, H.; Subramani, N.; Xu, W.; Yang, D.; Yerukola, A.; Zhou, J.We introduce GEM, a living benchmark for natural language Generation (NLG), its Evaluation, and Metrics. Measuring progress in NLG relies on a constantly evolving ecosystem of automated metrics, datasets, and human evaluation standards. Due to this moving target, new models often still evaluate on divergent anglo-centric corpora with well-established, but flawed, metrics. This disconnect makes it challenging to identify the limitations of current models and opportunities for progress. Addressing this limitation, GEM provides an environment in which models can easily be applied to a wide set of tasks and in which evaluation strategies can be tested. Regular updates to the benchmark will help NLG research become more multilingual and evolve the challenge alongside models. This paper serves as the description of the data for which we are organizing a shared task at our ACL 2021 Workshop and to which we invite the entire NLG community to participate. © 2021 Association for Computational LinguisticsItem Room temperature sliding wear behavior of Ti6Al4V: A review(American Institute of Physics Inc., 2021) Sreesha, R.B.; Kumar, D.; Chandraker, S.; Agrawal, A.High strength-to-weight ratio, high temperature stability, and bio-compatibility makes Ti6Al4V alloy an interesting choice for aerospace, automobile, chemical, and bio-medical industries. In spite of the several attractive properties, the application of the alloy is restricted in sliding interfaces. As a result, many studies, involving surface modifications of the alloy or the tribo-pair in general have surfaced for improvement in tribological properties. The details of tribological behavior of un-modified Ti6Al4V alloy in various operating and environmental conditions, can act as an initial data for the future researches aimed at improving its tribological properties. Thus, the present review is an attempt to put together the studies conducted to evaluate the sliding wear behavior of Ti6Al4V in both dry and lubricated condition at the room temperature. © 2021 Author(s).Item Performance of Recycled Coarse Aggregate Concretes with Basalt Fibers at Elevated Temperatures(Springer Science and Business Media Deutschland GmbH, 2022) Yaragal, S.C.; Hiremath, P.N.; Kalyan, M.M.; Kumar, D.; Shiji, P.P.The utilization of Construction and Demolition waste (C&D) is gaining importance due to rapid depletion of natural aggregates, as well as due to increased awareness worldwide towards sustainable development. Water absorption characteristics of adhered mortar associated with C&D aggregates has to an extent hindered the potential of extensively using Recycled Coarse Aggregate (RCA) in concretes. The study examines the performance of concretes with replacement of natural coarse aggregates by RCA in different proportions. Attempts were made to enhance the compressive strength of RCA based concretes using basalt fibers. Results, show that possibility of using RCA based concretes (either 50 or 100% replacement) is possible without compromising strength, by incorporating 1.5% basalt fibers. Use of basalt fibers result in 13 and 19% enhanced strengths to concretes (for 50 and 100% replacement) apart from exhibiting superior elevated temperature endurance. Study also includes microstructural investigation of RCA based concretes with and without basalt fibers at elevated temperatures. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.