Somani A.,University of Minnesota |
Somani A.,Dynapower Company |
Gupta R.K.,General Electric |
Mohapatra K.K.,University of Minnesota |
And 2 more authors.
IEEE Transactions on Industrial Electronics | Year: 2013
Electric drives with open-end winding ac machines offer certain advantages over drives with star-or delta-connected machines. Such drives have been recently considered for some applications such as electric vehicles. Circulating currents have been experimentally observed in such open-end winding ac drives. These currents have the effect of increasing conduction losses in the stator winding resistance of the ac machine. Two major causes for these currents have been identified as device voltage drops in power semiconductor devices and dead time used for shoot-through current protection. These effects are analyzed, and a mathematical description for predicting their severity is provided. Experimental results are presented that support the theory. The theory developed should be useful for devising solutions for this problem such as the design of common-mode filters. Two methods of suppressing the circulating currents are also outlined, and their experimental results are presented. © 1982-2012 IEEE.
Banerjee S.,University of Nevada, Reno |
Misra M.,University of Nevada, Reno |
Mohapatra S.K.,University of Nevada, Reno |
Howard C.,University of Nevada, Reno |
And 2 more authors.
Nanotechnology | Year: 2010
Titania (TiO2) nanotubular arrays provide an exciting material for dye sensitizing solar cells (DSSC) because of their large surface area, lower recombination losses, and fast charge transport properties along the nanotubes. In this paper, design of a next generation DSSC using a TiO 2 nanotubular membrane is discussed. A single step, green process is developed to produce stable large area, free-standing TiO2 nanotubular films (in a short time, 30-60min) by anodizing Ti using an organic electrolyte, containing disodium salt of ethylene diaminetetraacetic acid (Na2[H2EDTA]) as complexing agent, and subsequent drying. Transparent, crack-free TiO2 films, 20-41νm thick containing ordered hexagonal TiO2 nanotubes are achieved by this process. Films having a geometrical area up to 16.5cm2 with pore openings of 182nm have been obtained. These films have been etched to form membranes which provide an exciting prospect for front side illuminated DSSC with good mass and photon transport properties as well as wettability. A photovoltaic efficiency of 2.7% is achieved using a front side illuminated DSSC compared to 1.77% using back side illumination. © 2010 IOP Publishing Ltd.
Dash A.K.,Institute of Technical Education and Research |
Parhi D.R.K.,National Institute of Technology Rourkela
International Journal of Computational Materials Science and Surface Engineering | Year: 2011
The influence of cracks on the dynamic behaviour of a cracked cantilever beam with rectangular cross section is discussed in this work. Analytical and experimental investigations are carried out to find the relation between the change in natural frequencies and mode shapes for the cracked and un-cracked beam. Finite element analysis is being performed on the cracked structure to measure the vibration signatures, which is subsequently used in the design of smart system based on fuzzy logic for prediction of crack depths and locations following inverse problem approach. The fuzzy system is developed with relative natural frequencies and mode shapes as input parameters based on the triangular membership functions to calculate the deviation in the vibration parameters for the cracked dynamic structure. Results from experimental analysis are very close to the results predicted by the theoretical, finite element and fuzzy analysis. Copyright © 2011 Inderscience Enterprises Ltd.
Panda K.C.,Institute of Technical Education and Research |
Bhattacharyya S.K.,CSIR - Central Electrochemical Research Institute |
Journal of Reinforced Plastics and Composites | Year: 2011
This article presents an experimental investigation on the performance of 2500 mm long reinforced concrete (RC) T-beams strengthened in shear using epoxy bonded glass fiber fabric. The experimental program consisted of testing of 18 full scale simply supported RC T-beams. Nine beams are used as control beam with three different stirrups spacing without glass fiber reinforced polymer (GFRP) wrap and rest nine beams are strengthened in shear with one, two, and three layers of GFRP sheet on side of the web of the T-beams for each type of stirrup spacing. The objective of this study is to evaluate the effectiveness, shear behavior, the cracking pattern, and modes of failure of strengthened RC T-beams. The experimental result indicates that RC T-beams strengthened in shear with side-bonded GFRP sheet increases the effectiveness by 12.5% to 50%. The theoretical study demonstrated that, when compared with ACI guidelines, the proposed model gives better agreement with the test results available. © The Author(s) 2011.
Parhi D.R.,National Institute of Technology Rourkela |
Dash A.K.,Institute of Technical Education and Research
Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science | Year: 2011
This article analyses the dynamic behaviour of a beam structure containing multiple transverse cracks using neural network controller. The first three natural frequencies and mode shapes have been calculated using theoretical, finite-element, and experimental analysis for the cracked andun-cracked beam.Comparisons of the results among theoretical, finite-element, and experimental analysis have also been presented. The calculated vibration signatures were used to train the feed-forward multi-layered neural network controller with back-propagation technique for the prediction of cracks. Relative crack locations and relative crack depths are the output of the neural controller. Results obtained from the various analyses are validated using the developed experimental set-up. Results from neural controller have been presented for comparison with the output from theoretical, finite-element, and experimental analysis. From the evaluation of the performance of the neural network controller it is observed that the developed method can be used as a crack diagnostic tool in the domain of dynamically vibrating structures. © Authors 2011.
Singh A.V.,Indian Institute of Technology Delhi |
Chandra S.,Indian Institute of Technology Delhi |
Bose G.,Institute of Technical Education and Research
Thin Solid Films | Year: 2011
Aluminum nitride (AlN) films were deposited on a variety of substrates (glass, Si, oxidized Si, Al-SiO2-Si, Cr-SiO2-Si, and Au-Cr-SiO2-Si) by radio frequency (RF) magnetron sputtering using an AlN target. The films were deposited without external substrate heating. The effect of RF power, ambient gas (Ar and Ar-N2) and sputtering pressure on deposition rate and crystallinity were investigated. The structure and morphology of the films were studied by X-ray diffraction, scanning electron microscopy and atomic force microscopy techniques. These investigations revealed that the AlN films prepared in mixed gas ambient (Ar-N2) were highly c-axis oriented with moderate surface roughness on all the substrate. A strong IR absorption band was observed around 670 cm- 1 which confirms the presence of Al-N bond in the film. The dc resistivity of the films was measured to be in the range of 1011 to 1012 Ω-cm at moderate electric fields. The application of these films in piezoelectric based micro-electro-mechanical systems is discussed. © 2011 Elsevier B.V. All rights reserved.
Krishnanand K.R.,Siksha ‘O’ Anusandhan University |
Rout P.K.,Institute of Technical Education and Research |
Panigrahi B.K.,Indian Institute of Technology Delhi |
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2010
This paper presents the application of Seeker Optimization Algorithm (SOA) to constrained economic load dispatch problem. Independent simulations were performed over separate systems with different number of generating units having constraints like prohibited operating zones and ramp rate limits. The performance is also compared with other existing similar approaches. The proposed methodology was found to be robust, fast converging and more proficient over other existing techniques. © 2010 Springer-Verlag.
Mohanty J.R.,Sambalpur University |
Das H.C.,Institute of Technical Education and Research |
Indian Journal of Engineering and Materials Sciences | Year: 2014
Most of engineering structures and components come across complicated fatigue loading during their service lives. From economical point of view it is essential to predict residual life in order to avoid catastrophic failure by scheduling suitable inspection intervals. In the present investigation, fatigue life of 7020 T7 Al alloy under constant amplitude loading with load ratio effects has been predicted by adopting an 'Exponential Model'. The performance of the proposed model has been compared with artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS). It is observed that the fatigue life predicted by exponential model is comparatively better with maximum percentage deviation of -0.65% in comparison to ANN and ANFIS which are -4.37% and -2.48% respectively.
Rana G.,Institute of Technical Education and Research |
Ballav B.,Institute of Technical Education and Research |
Pattanayak B.K.,Institute of Technical Education and Research
Proceedings - 2015 14th International Conference on Information Technology, ICIT 2015 | Year: 2015
Routing is the main procedure for data transmission in ad hoc network. Due to mobility of nodes, bandwidth and energy constraints are limited and it is very challenging task for this kind of network to transfer data packets towards proper destination. Through this paper, we compared characteristics and behavior of few ad hoc communicating protocols namely Ad Hoc On-demand Distance Vector (AODV), Ad hoc On-demand Multipath Distance Vector (AOMDV), Dynamic Source Routing (DSR), Destination Sequence Distance Vector (DSDV) and Power Aware Adhoc On-demand Distance Vector (PAAODV). Their performance comparison is based on four performance characteristics i.e. ratio of packets delivery, throughput, energy conservation and average delay with respect to number of nodes. These simulations are performed using network simulator (NS 2.35). © 2015 IEEE.
Behera S.K.,Institute of Technical Education and Research |
Nayak B.,Institute of Technical Education and Research
International Journal of Applied Engineering Research | Year: 2014
In this paper we proposed an approximation method named Sanjaya and Bimalesh’s approximation method (SBAM) for finding the optimal solution of the Transportation problem. In this paper we propose a method that could result in better initial solutions hence we reach the optimal solution in less number of iterations. This method is very efficient for the decision makers who are dealing with logistic and supply chain related issue. © Research India Publications.