Acharya S.K.,National Institute of Technology Rourkela |
Mishra P.,National Institute of Technology Rourkela |
Mehar S.K.,Op Jindal Institute Of Technology
BioResources | Year: 2011
Bagasse is a by-product of the sugarcane milling process, and it also is an important fuel resource for that industry. In this study an attempt has been made to utilize this by-product to prepare a composite using epoxy resin. The fibers surface was modified by alkali treatment with 5% NaOH solution for 0, 2, 4 and 6 hrs. The effect of fiber surface modification on the mechanical properties such as flexural strength of the composites was investigated with the fibers as received from the milling process. It was found that alkali-treated bagasse/epoxy composites significantly improved the flexural strength of the composite. An SEM investigation also indicated that the surface modifications improved the fiber-matrix interaction.
Satapathy K.K.,Op Jindal Institute Of Technology |
Khan F.,National Institute of Technology Raipur
Advanced Materials Letters | Year: 2013
The mechanoluminescence (ML) of γ-irradiated ZnAl2O4: Dy phosphor has been studied. ZnAl2O4 samples having different concentrations of Dy were prepared by solution combustion technique by using hydrazine as a fuel. ML was excited impulsively by dropping a load onto the sample. Two distinct peaks have been observed in the ML intensity versus time curve. Maximum intensity is obtained for 0.1 mol% of Dy doped ZnAl2O4 phosphor. ML spectra of the phosphors show two distinct peaks around 482 nm and 585 nm which is characteristic emission of Dy3+. It is also observed that the ML intensity of the samples increases almost linearly with increasing mass of the sample and gamma ray doses given to the sample. Experimental results suggest that the ML excitation is related to the movement of dislocation with defect centres and it may be used for dosimeter applications. © 2013 VBRI press.
Gupta S.K.,Op Jindal Institute Of Technology |
Jana P.K.,Indian School of Mines
Wireless Personal Communications | Year: 2015
Energy efficient clustering and routing are two well known problems in wireless sensor networks. In this paper, we propose genetic algorithm based approaches for clustering and routing in wireless sensor networks. The clustering is based on residual energy of the gateways and distance from sensor nodes to their corresponding cluster head. The routing scheme is also based on the residual energy of the gateways along with a trade-off between transmission distance and number of forwards. We perform extensive simulations of the proposed algorithms and compare the simulation results with that of the existing algorithms. The results demonstrate that the proposed algorithms outperform the existing algorithms in terms of various performance metrics including energy consumption, number of active nodes, first gateway die and number of dead gateway per round. © 2015, Springer Science+Business Media New York.
Sangewar R.K.,Op Jindal Institute Of Technology
International Journal of Energy for a Clean Environment | Year: 2014
Artificial roughness elements in the form of hemispherical protruded impressions were designed and developed on a 14-gauge commercially available aluminum sheet with the help of appropriate dies and punches. This aluminum sheet was used as an absorber for a solar air heater. Artifi cial roughness augments turbulence and heat transfer to the air fl owing over. This aluminum solar energy absorber with protrusions had been tested for fl ow Reylonds number of 3500-15,000 under actual outdoor conditions in OPJU campus. The thermal effi ciency of a roughened solar air heater was found to be a strong function of air mass fl ow rate. Maximum thermal effi ciencies were observed as 80%, 70%, and 60% at mass fl ow rates of 1 = 0.0417, 2 = 0.0313, and 3 = 0.0208 kg/s, respectively. The collector heat removal factor (FR) varied from 0.42 to 0.50, the collector effi ciency factor (F') varied from 0.45 to 0.75, and the heat removal factor based on outlet air (F0) varied from 0.55 to 0.80 at corresponding air mass fl ow rate. For a given value of p/e (12), the Reynolds number and increased value of e/D (0.045-0.055), there was an augmentation in the Nusselt number 2.67 and 3.62 with respect to a smooth collector. The Nusselt number was maximum for a p/e value of 12 and it decreased in either sides of 12. The values of F0Ul for roughened and smooth collectors were computed to be 10 W/m2·K and 3 W/m2·K and F0(τα) to be 0.837 and 0.377, respectively. For e/D equal to 0.055, 0.045, and 0.035 and constant p/e = 12, the values of F0, Ul, and F0(ατ) are 10, 09, and 08 W/m2·K and 0.884, 0.746, and 0.664, respectively for this solar absorber. There was a ±5% variation of experimental and predicted Nusselt number based on the modifi ed correlation developed from experimental data analysis. © 2014 by Begell House, Inc.
Seth G.S.,Indian School of Mines |
Sarkar S.,Indian School of Mines |
Hussain S.M.,Op Jindal Institute Of Technology
Ain Shams Engineering Journal | Year: 2014
An investigation of the effects of Hall current and rotation on unsteady hydromagnetic natural convection flow with heat and mass transfer of an electrically conducting, viscous, incompressible and optically thick radiating fluid past an impulsively moving vertical plate embedded in a fluid saturated porous medium, when temperature of the plate has a temporarily ramped profile, is carried out. Exact solution of the governing equations is obtained in closed form by Laplace transform technique. Exact solution is also obtained in case of unit Schmidt number. Expressions for skin friction due to primary and secondary flows and Nusselt number are derived for both ramped temperature and isothermal plates. Expression for Sherwood number is also derived. The numerical values of primary and secondary fluid velocities, fluid temperature and species concentration are displayed graphically whereas those of skin friction are presented in tabular form for various values of pertinent flow parameters. © 2013 Production and hosting by Elsevier B.V.