National Institute of Technology Rourkela ,formerly Regional Engineering College Rourkela , is a publicly funded institute of higher learning for engineering and technology located in the steel city of Rourkela, Odisha, India. It is one of the 30 National Institutes of Technology in India and has been recognized as an Institute of National Importance by the National Institutes of Technology Act, 2007. Wikipedia.
Behera R.K.,Childrens Hospital Oakland Research Institute |
Behera R.K.,National Institute of Technology Rourkela |
Theil E.C.,Childrens Hospital Oakland Research Institute |
Theil E.C.,North Carolina State University
Proceedings of the National Academy of Sciences of the United States of America | Year: 2014
Ferritin biominerals are protein-caged metabolic iron concentrates used for iron-protein cofactors and oxidant protection (Fe2+ and O 2 sequestration). Fe2+ passage through ion channels in the protein cages, like membrane ion channels, required for ferritin biomineral synthesis, is followed by Fe2+ substrate movement to ferritin enzyme (Fox) sites. Fe2+ and O2 substrates are coupled via a diferric peroxo (DFP) intermediate, λmax 650 nm, which decays to [Fe3+-O-Fe3+] precursors of caged ferritin biominerals. Structural studies show multiple conformations for conserved, carboxylate residues E136 and E57, which are between ferritin ion channel exits and enzymatic sites, suggesting functional connections. Here we show that E136 and E57 are required for ferritin enzyme activity and thus are functional links between ferritin ion channels and enzymatic sites. DFP formation (K cat and kcat/Km), DFP decay, and protein-caged hydrated ferric oxide accumulation decreased in ferritin E57A and E136A; saturation required higher Fe2+ concentrations. Divalent cations (both ion channel and intracage binding) selectively inhibit ferritin enzyme activity (block Fe2+ access), Mn2+ ≪ Co2+ < Cu2+ < Zn2+, reflecting metal ion-protein binding stabilities. Fe2+-Cys126 binding in ferritin ion channels, observed as Cu2+-S-Cys126 charge-transfer bands in ferritin E130D UV-vis spectra and resistance to Cu2+ inhibition in ferritin C126S, was unpredicted. Identifying E57 and E136 links in Fe2+ movement from ferritin ion channels to ferritin enzyme sites completes a bucket brigade thatmoves external Fe2+ into ferritin enzymatic sites. The results clarify Fe2+ transport within ferritin and model molecular links between membrane ion channels and cytoplasmic destinations.
Sahoo B.,National Institute of Technology Rourkela
Computers and Mathematics with Applications | Year: 2011
The flow and heat transfer of an electrically conducting non-Newtonian fluid due to a stretching surface subject to partial slip is considered. The constitutive equation of the non-Newtonian fluid is modeled by that for a third grade fluid. The heat transfer analysis has been carried out for two heating processes, namely, (i) with prescribed surface temperature (PST-case) and (ii) prescribed surface heat flux (PHFcase) in presence of a uniform heat source or sink. Suitable similarity transformations are used to reduce the resulting highly nonlinear partial differential equations into ordinary differential equations. The issue of paucity of boundary conditions is addressed and an effective second order numerical scheme has been adopted to solve the obtained differential equations. The important finding in this communication is the combined effects of the partial slip, magnetic field, heat source (sink) parameter and the third grade fluid parameters on the velocity, skin friction coefficient and the temperature field. It is interesting to find that slip decreases the momentum boundary layer thickness and increases the thermal boundary layer thickness, whereas the third grade fluid parameter has an opposite effect on the thermal and velocity boundary layers. © 2010 Elsevier Ltd. All rights reserved.
Samantaray S.R.,National Institute of Technology Rourkela
IEEE Transactions on Power Delivery | Year: 2011
This paper proposes an effective fault detection technique in distance relaying using phase space. This is based on an embedding theorem which shows that a time series can be mapped to a higher dimensional space called phase space through embedding. Thus, a sampled signal can be transformed in to the phase space so that its features can be more clearly viewed. The original signal is decoupled into two parts as: normal and disturbance part. The fault detection is easily achieved as the disturbance part of the signal produces an irregular shape compared to the shape produced from the normal part of the signal. The fault detection signal using phase space (FDPS), derived from phase-space transformation, effectively detects the faults in the transmission line with wide variations in operating conditions. The results from an extensive study indicate that the proposed FDPS can reliably detect the faults in distance relaying. © 2010 IEEE.
Saha Ray S.,National Institute of Technology Rourkela
Annals of Nuclear Energy | Year: 2012
In the present paper, the numerical approximation methods, applied to efficiently calculate the solution for stochastic point kinetic equations (Hetrick, 1993; Kinard and Allen, 2004) in nuclear reactor dynamics, are investigated. A system of Itô stochastic differential equations has been analyzed to model the neutron density and the delayed neutron precursors in a point nuclear reactor. The resulting system of Itô stochastic differential equations are solved over each time-step size. The methods are verified by considering different initial conditions, experimental data and over constant reactivities. The computational results indicate that the methods are simple and suitable for solving stochastic point kinetic equations. In this article, a numerical investigation is made in order to observe the random oscillations in neutron and precursor population dynamics in subcritical and critical reactors. © 2012 Elsevier Ltd. All rights reserved.
Satapathy A.K.,National Institute of Technology Rourkela
International Journal of Thermal Sciences | Year: 2010
This paper deals with analytical solution of steady-state heat transfer for laminar, two-dimensional and rarefied gas flow in an infinite microtube subjected to mixed boundary conditions. To account for the slip-flow characteristics of microscale heat transfer, temperature jump condition at the wall has been incorporated in the model while the fluid velocity is assumed to be constant (slug flow). The energy equation in the thermal entrance region has been solved by the method of separation of variables. The solution yields closed form expressions for bulk-mean temperature and Nusselt number in terms of Knudsen number and Peclet number. © 2009 Elsevier Masson SAS. All rights reserved.
Ghosh Chaudhuri R.,National Institute of Technology Rourkela |
Paria S.,National Institute of Technology Rourkela
Chemical Reviews | Year: 2012
A study was conducted to investigate classes, properties, synthesis mechanisms, characterization, and applications of core and shell nanoparticles. It was found that concentric spherical core/shell nanoparticles were the most common where a simple spherical core particle was completely coated by a shell of a different material. Approaches for nanomaterial synthesis were broadly divided into two categories, such as top-down and bottom-up. The top-down approach used traditional workshop or microfabrication methods where externally controlled tools were used to cut, mill, and shape materials into the desired shape and order. A large variety of core/shell nanoparticles were available with a wide range of applications. The classification of all the available core/shell nanoparticles depended on their industrial applications or was based on some other property.
Maity S.,National Institute of Technology Rourkela
IEEE Transactions on Circuits and Systems I: Regular Papers | Year: 2013
This paper finds and investigates the application of fixed-event-time based discretized sliding mode (DSM) controller in dc-dc buck converter, to achieve fast transient response and high robustness under wide parameters variation. We show that how these can be achieved by integrating the concept of Utkin's equivalent control law and discontinuous border-collision bifurcation (DBCB) theory developed for 2-D discontinuous piecewise smooth (PWS) maps. Moreover, based on derived 2-D discontinuous maps of DSM-controlled converter, we investigate its inherent steady-state dynamical properties or bifurcation behaviors under different parameters variation. Numerically as well as experimentally obtained bifurcation diagrams are then presented to show the domains of existence of different oscillatory modes and their sequence of occurrence. Such phenomena are not only useful to study the robustness of the system but may also facilitates to design the input filter with fast transient response. The performance of DSM controller is experimentally verified and compared with hysteresis and classical peak current-mode controller. © 2004-2012 IEEE.
Ganguly S.,National Institute of Technology Rourkela
IEEE Transactions on Power Systems | Year: 2014
This paper presents a particle swarm optimization (PSO)-based multi-objective planning algorithm for reactive power compensation of radial distribution networks with unified power quality conditioner (UPQC) allocation. A UPQC consists of a series and a shunt inverter. The UPQC model based on phase angle control (UPQC-PAC) is used. In UPQC-PAC, the series inverter injects a voltage with controllable phase angle in such a way that the voltage magnitude at load end remains unchanged. Due to the phase angle shift, the series inverter participates in load reactive power compensation along with the shunt inverter during healthy operating condition. In the proposed approach, the optimal location, the optimal reactive power compensation required at the location, and the optimal design parameters of UPQC are determined by minimizing three objective functions: 1) the rating of UPQC, 2) network power loss, and 3) percentage of nodes with undervoltage problem. These objectives are simultaneously minimized to obtain a set of non-dominated solutions using multi-objective PSO (MOPSO). The performances of two MOPSO variants are compared and the better one is used in all subsequent studies. A load flow algorithm including the UPQC-PAC model is devised. The performance of the proposed algorithm is validated with different case studies. © 2013 IEEE.
Subudhi B.,National Institute of Technology Rourkela |
Pradhan R.,National Institute of Technology Rourkela
IEEE Transactions on Sustainable Energy | Year: 2013
This paper provides a comprehensive review of the maximum power point tracking (MPPT) techniques applied to photovoltaic (PV) power system available until January, 2012. A good number of publications report on different MPPT techniques for a PV system together with implementation. But, confusion lies while selecting a MPPT as every technique has its own merits and demerits. Hence, a proper review of these techniques is essential. Unfortunately, very few attempts have been made in this regard, excepting two latest reviews on MPPT [Salas , 2006], [Esram and Chapman, 2007]. Since, MPPT is an essential part of a PV system, extensive research has been revealed in recent years in this field and many new techniques have been reported to the list since then. In this paper, a detailed description and then classification of the MPPT techniques have made based on features, such as number of control variables involved, types of control strategies employed, types of circuitry used suitably for PV system and practical/ commercial applications. This paper is intended to serve as a convenient reference for future MPPT users in PV systems. © 2010-2012 IEEE.
Bal S.,National Institute of Technology Rourkela
Materials and Design | Year: 2010
Epoxy nanocomposites of different content of carbon nanofibers up to 1 wt.% have been fabricated under room temperature and refrigerated curing conditions. The composites were studied in terms of mechanical and electrical properties. Flexural modulus and hardness were found to increase significantly in refrigerated samples due to prevention of aggregates of nanofibers during cure condition. Increase and shifting in G-band by Raman spectra of these samples confirmed stress transfer and reinforcement between epoxy matrix and carbon nanofiber. Electrical conductivity improved by 3-6 orders after infusing carbon nanofibers in insulating epoxy. Room temperature samples acquired higher conductivity that was attributed to network formation by aggregates of nanofibers along the fiber alignment direction as revealed by electron microscopic studies. © 2009 Elsevier Ltd. All rights reserved.