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Roy S.,Indian Institute of Technology Ropar
IEEE Transactions on Sustainable Energy | Year: 2012

Randomness of wind speed around a short-duration-stable mean value is commonly referred to as short duration wind variation. This paper investigates the effect of substantial wind-based capacity inclusion on optimal load dispatch, with the source wind susceptible to short duration variations. Analytical formulation of the economic load dispatch (ELD) problem inclusive of wind power generation is presented separately for cases with and without representation of transmission losses. In each formulation, the effect of short duration wind variations is included as an aggregate, thereby avoiding the complexity of stochastic models. Three-generator and 20-generator study cases are discussed to illustrate two distinct aspects of the ELD problem. First, the optimal cost, losses, and system-$λ are presented across a range of short-duration-stable mean wind speed. Thereafter, the sensitivity of all three metrics is discussed with reference to different levels of short duration wind variations. © 2012 IEEE.


Roy S.,Indian Institute of Technology Ropar
IEEE Transactions on Sustainable Energy | Year: 2012

The distorted output of a pitch angle controlled (PAC) horizontal axis turbine, as influenced by short duration wind variations like turbulence and gusts, is analyzed under the assumption of two-parameter Weibull statistics. The well accepted concept of turbulence intensity is used as a parametric measure of short duration wind variations. Analytical expressions are formulated and used to estimate the short duration aggregate power output from a turbine, together with the fractional deviations from corresponding ideal zero-turbulence values. Operating conditions of constant turbulence intensity, and constant wind speed standard deviation, are considered separately for the studies. Sensitivity of turbine output power to cut-in and rated values of wind speed are evaluated and discussed. © 2010-2012 IEEE.


Tripathi D.,Indian Institute of Technology Ropar
International Journal of Thermal Sciences | Year: 2012

A mathematical model is constructed to study the influence of heat transfer in swallowing of food bolus (water) through the oesophagus. The food bolus is supposed to be viscous fluid and the geometry of wall surface of oesophagus is considered as peristaltic wave. The expressions for temperature field, axial velocity, transverse velocity, volume flow rate, pressure gradient, local wall shear stress, mechanical efficiency, stream function and reflux limit are obtained under the assumptions of long wavelength and low Reynolds number. The effect of heat transfer on two inherent phenomena (reflux and trapping) of peristaltic flow is discussed numerically. The comparative study of integral and non-integral number of wave propagating along the channel is discussed under influence of emerging physical parameters. Revelation is that when the magnitude of Grashof number and thermal conductivity increase the pressure along the entire length of the channel reduces whereas the efficiency of pumping increases. Reflux region is found to be increasing function of the both parameters. It is found that the size of upper trapped bolus contracts while size of lower trapped bolus expands with increasing the effect of heat transfer. © 2011 Elsevier Masson SAS. All rights reserved.


Anu Prathap M.U.,Indian Institute of Technology Ropar | Srivastava R.,Indian Institute of Technology Ropar
Sensors and Actuators, B: Chemical | Year: 2013

In this study, ion-exchange property and mesoporosity of polyaniline were exploited in the simultaneous detection of ascorbic acid (AA), dopamine (DA), uric acid (UA), and tryptophan (Trp), which is very important in the clinical diagnosis. Mesoporous polyaniline synthesized by the self-assembly of mixed (ionic and non-ionic) soft template was ion-exchanged to form transition metal ion-exchanged mesoporous polyaniline (M-Meso-PANI). Materials were characterized by X-ray diffraction, nitrogen sorption, scanning electron microscopy, UV-vis, and FT-IR spectroscopic methods. M-Meso-PANI based electrochemical sensors were fabricated for the simultaneous determination studies. For comparative electrochemical studies, transition metal exchanged polyaniline (M-PANI) were also investigated. Fe-Meso-PANI exhibited higher sensitivity and volumetric response for these bio-molecules compared to Fe-PANI, which is due to the highly dispersed Fe2+ in high surface area Meso-PANI matrix. Fe-Meso-PANI exhibited the highest sensitivity, selectivity among the M-Meso-PANI materials. The analytical performance of this sensor was also demonstrated for the blood serum and urine samples. The reliability and stability of the modified electrode provides a good possibility for applying the technique in routine analysis for a selected class of electroactive bio-molecules. © 2012 Elsevier B.V. All rights reserved.


Tripathi D.,Indian Institute of Technology Ropar
Journal of Bionic Engineering | Year: 2012

A mathematical model is constructed to examine the characteristics of three layered blood flow through the oscillatory cylindrical tube (stenosed arteries). The proposed model basically consists three layers of blood (viscous fluids with different viscosities) named as core layer (red blood cells), intermediate layer (platelets/white blood cells) and peripheral layer (plasma). The analysis was restricted to propagation of small-amplitude harmonic waves, generated due to blood flow whose wave length is larger compared to the radius of the arterial segment. The impacts of viscosity of fluid in peripheral layer and intermediate layer on the interfaces, average flow rate, mechanical efficiency, trapping and reflux are discussed with the help of numerical and computational results. This model is the generalized form of the preceding models. On the basis of present discussion, it is found that the size of intermediate and peripheral layers reduces in expanded region and enhances in contracted region with the increasing viscosity of fluid in peripheral layer, whereas, opposite effect is observed for viscosity of fluid in intermediate layer. Final conclusion is that the average flow rate and mechanical efficiency increase with the increasing viscosity of fluid in both layers, however, the effects of the viscosity of fluid in both layers on trapping and reflux are opposite to each other. © 2012 Jilin University.


Tripathi D.,Indian Institute of Technology Ropar
Transport in Porous Media | Year: 2012

The present investigation deals with a theoretical study of the peristaltic hemodynamic flow of couple-stress fluids through a porous medium under the influence of wall slip condition. This study is motivated towards the physiological flow of blood in the micro-circulatory system, by taking account of the particle size effect. Reynolds number is small enough and the wavelength to diameter ratio is large enough to negate inertial effects. Analytical solutions for axial velocity, pressure gradient, frictional force, stream function and mechanical efficiency are obtained. Effects of different physical parameters reflecting couple-stress parameter, permeability parameter, slip parameter, as well as amplitude ratio on pumping characteristics and frictional force, streamlines pattern and trapping of peristaltic flow pattern are studied with particular emphasis. The computational results are presented in graphical form. This study puts forward an important observation that pressure reduces by increasing the magnitude of couple-stress parameter, permeability parameter, slip parameter, whereas it enhances by increasing the amplitude ratio. © 2012 Springer Science+Business Media B.V.


Roy S.,Indian Institute of Technology Ropar
IEEE Transactions on Energy Conversion | Year: 2013

The inexact power output from a pitch angle-controlled (PAC) horizontal-axis turbine, as influenced by short duration wind variations like turbulence and gusts, has been the subject of well-documented experimental and empirical studies. In this paper, an analytical interpretation of the phenomena is presented under assumption of two-parameter Weibull statistics for short duration wind variations. The popular concept of turbulence intensity is used as a parametric measure for randomness of wind speed. The formulations culminate in analytical expressions for two distinct metrics of power distortion, namely: (a) the short duration output power from the turbine as a mean distinct from corresponding ideal zero-Turbulence value; and (b) the output power variability as a quantification of randomness around the mean. Estimates of both metrics are presented for operating conditions in accordance with the well-known IEC 61400-1 standards. Trends indicated by computed estimates are found to be consistent with empirically observed data from field studies that are reported in the literature. © 1986-2012 IEEE.


Anu Prathap M.U.,Indian Institute of Technology Ropar | Srivastava R.,Indian Institute of Technology Ropar
Nano Energy | Year: 2013

NiCo2O4 is synthesized by the hydrothermal route in the presence of urea. Material is characterized by a complementary combination of X-ray diffraction, nitrogen sorption, and Scanning electron microscopy. The electrochemical oxidation of methanol is investigated at NiCo2O4 modified electrode in the alkaline medium using cyclic voltammetry and chronoamperometry methods. Electrocatalytic activity of NiCo2O4 is compared with the NiO and Co3O4 modified electrodes. A detailed investigation is made for the electrocatalytic oxidation of methanol by varying several reaction parameters such as potential scan rate, methanol concentration, etc. Mechanism of methanol oxidation is proposed based on the cyclic voltammetry study. Double steps chronoamperometry study shows that the methanol electro-oxidation is an irreversible reaction. Electrocatalytic activity of the methanol oxidation at NiCo2O4 modified electrode is found to be significantly higher than that of NiO and Co3O4 modified electrodes. © 2013 Elsevier Ltd.


Srivastava R.,Indian Institute of Technology Ropar
Journal of Colloid and Interface Science | Year: 2010

A novel and eco-friendly route for the synthesis of porous CeO2 microstructure is reported. The citric acid mediated economical route is developed for the synthesis of a three-dimensional (3D) flowerlike micro/nanocomposite structure. Materials were characterized by a complementary combination of X-ray diffraction (XRD), nitrogen sorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron microscopy (XPS). CeO2 samples obtained have remarkably high surface area when compared to the commercial CeO2 sample. The surface area of CeO2 sample decreased upon calcination at higher temperature. However, the surface area is still almost 20 times more when compared to the commercial CeO2 sample. TEM investigation reveals that upon calcination at higher temperature, the size of the crystal increased but the short range order was merely disturbed. The analyses shows that the present method is suitable as a direct route for synthesizing nanoporous CeO2. Micro/nanocomposite CeO2 was found to be an excellent sorbent for the removal of poisonous pollutants present in water, such as arsenic (As) and chromium (Cr). © 2010 Elsevier Inc.


Gupta A.K.,Indian Institute of Technology Ropar
International Journal of Modern Physics C | Year: 2013

The development of real time traffic flow models for urban road networks is of paramount importance for the purposes of optimizing and control of traffic flow. Motivated by the modeling of road networks in last decade, this paper proposes a different and simplified approach, known as section approach to model road networks in the framework of macroscopic traffic flow models. For evaluation of the traffic states on a single road, an anisotropic continuum GK-model developed by [Gupta and Katiyar, J. Phys. A 38, 4069 (2005)] is used as a single-section model. This model is applied to a two-section single lane road with points of entry and exits. In place of modeling the effect of off- and on-ramps in the continuity equation, a set of special boundary condition is taken into account to treat the points of entry and exit. A four-section road network comprised of two one-lane roads is also modeled using this methodology. The performances of the section approaches are investigated and obtained results are demonstrated over simulated data for different boundary conditions. © World Scientific Publishing Company.

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