IIT KharagpurWB

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IIT KharagpurWB

India
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Manna S.,Materials Science Center | Saha P.,Materials Science Center | Roy D.,IIT KharagpurWB | Sen R.,IIT KharagpurWB | Adhikari B.,Materials Science Center
Applied Surface Science | Year: 2015

Waterborne fluoride is usually removed from water by coagulation, adsorption, ion exchange, electro dialysis or reverse osmosis. These processes are often effective over narrow pH ranges, release ions considered hazardous to human health or produce large volumes of toxic sludge that are difficult to handle and dispose. Although plant matters have been shown to remove waterborne fluoride, they suffer from poor removal efficiency. Following from the insight that interaction between microbial carbohydrate biopolymers and anionic surfaces is often facilitated by lipids, an attempt has been made to enhance fluoride adsorption efficiency of jute by grafting the lignocellulosic fiber with fatty acyl chains found in vegetable oils. Fluoride removal efficiency of grafted jute was found to be comparable or higher than those of alternative defluoridation processes. Infrared and X-ray photoelectron spectroscopic evidence indicated that hydrogen bonding, protonation and C-F bonding were responsible for fluoride accumulation on grafted jute. Adsorption based on grafted jute fibers appears to be an economical, sustainable and eco-friendly alternative technique for removing waterborne fluoride. © 2015 Elsevier B.V. All rights reserved.


Ghatak S.,IIT KharagpurWB | Manna S.,Materials Science Center | Roy D.,IIT KharagpurWB
Geomicrobiology Journal | Year: 2015

Subsurface geotechnical data from a cemented tailings sand site in eastern India indicated that the cementation was at least partially biogenic. Three strains of aerobic soil-residing bacteria from this site exhibited capabilities of producing extracellular polymeric substance, calcite and struvite when grown in minimal mineral salt media. These strains grew easily under a variety of physical, chemical and nutritional conditions. Drained triaxial testing of loose sand samples indicated that they became stronger upon hosting these strains. No details on EPS and calcite production of these isolates and the effects of these products on soil behavior were found in the literature. © 2015, Copyright © Taylor & Francis Group, LLC.


Pfleging W.,Karlsruhe Institute of Technology | Kumari R.,IIT KharagpurWB | Besser H.,Karlsruhe Institute of Technology | Scharnweber T.,Karlsruhe Institute of Technology | Majumdar J.D.,IIT KharagpurWB
Applied Surface Science | Year: 2015

In the present study, a detailed study of the characterization of laser-surface textured titanium alloy (Ti-6Al-4V) with line and dimple geometry developed by using an ArF excimer laser operating at a wavelength of 193 nm with a pulse length of 5 ns is undertaken. The characterization of the textured surface (both the top surface and cross section) is carried out by scanning electron microscopy, electron back scattered diffraction (EBSD) technique and X-ray diffraction techniques. There is refinement of microstructure along with presence of titanium oxides (rutile, anatase and few Ti2O3 phase) in the textured surface as compared to as-received one. The area fractions of linear texture and dimple texture measured by image analysis software are 45% and 20%, respectively. The wettability is increased after laser texturing. The total surface energy is decreased due to linear (29.6 mN/m) texturing and increased due to dimple (67.6 mN/m) texturing as compared to as-received Ti-6Al-4V (37 mN/m). The effect of polar component is more in influencing the surface energy of textured surface. © 2015 Elsevier B.V. All rights reserved.


Roy K.,IIT KharagpurWB | Murthy P.V.S.N.,IIT KharagpurWB
International Journal of Heat and Mass Transfer | Year: 2015

The effect of the Soret parameter on the convective stability of double diffusive convection solely because of the viscous dissipation in a horizontal porous channel is studied. The lower boundary is adiabatic whereas the upper boundary is considered to be isothermal. The convective stability of the present system is governed by the solutal Rayleigh number (R) and is influenced by the viscous dissipation parameter (ξ), Lewis number (Le) and Soret parameter (Sr). For non positive values of the Soret parameter, the longitudinal rolls happen to be the most unstable ones when ξ takes small values. With positive values of the Soret parameter, the transverse rolls are seen to be the most unstable for relatively smaller values of the viscous dissipation parameter. As the viscous dissipation effect becomes stronger, the longitudinal rolls become the most unstable ones even for positive Soret parameter and the transverse rolls become more unstable for non-positive Soret parameter. It is observed that the Soret parameter has significant effect on convective instability and this is discussed. It has also been noticed that viscous dissipation shows a dual effect in presence of the Soret effect. For fixed values of the viscous dissipation parameter and Lewis number, negative values for the Soret number advances the onset of convection. Though positive values of the Soret parameter stabilizes the flow with smaller values of the Lewis number, but it destabilizes the flow when Lewis number and viscous dissipation parameter take larger values. © 2015 Elsevier Ltd. All rights reserved.


Paul A.B.,IIT GuwahatiAssam | Chakraborty S.,IIT KharagpurWB | De S.,IIT GuwahatiAssam | Nandi S.,IIT GuwahatiAssam | Biswas S.,IIT GuwahatiAssam
International Symposium on Advanced Networks and Telecommunication Systems, ANTS | Year: 2016

Heterogeneous Wireless Mesh Networks (HetMesh) is a promising high throughput technology for multi-hop data forwarding by mobile clients and backbone routers in a dynamic environment. HetMesh supports Wifi-Direct facility and other separate access technologies in its mobile clients, which makes the selection of a suitable next hop forwarder for data transmission challenging. This paper proposes a unified path determination scheme for high throughput HetMesh, where a novel resilient path metric is defined by combining multiple path selection criteria to leverage the resource availability of clients for acting as potential forwarders. The proposed scheme can be augmented with any existing hybrid routing protocol to improve its path selection quality, as well as to make the path selection process adaptive. The performance of the proposed scheme is evaluated through testbed as well as simulation results. The analysis shows that the proposed path selection mechanism shows on average 30%-50% improvement in average throughput, while also improving other performance metrics. © 2015 IEEE.


Tulsyan A.,Massachusetts Institute of Technology | Bhushan Gopaluni R.,University of British Columbia | Khare S.R.,IIT KharagpurWB
Computers and Chemical Engineering | Year: 2016

The main purpose of this primer is to systematically introduce the theory of particle filters to readers with limited or no prior understanding of the subject. The primer is written for beginners and practitioners interested in learning about the theory and implementation of particle filtering methods. Throughout this primer we highlight the common mistakes that beginners and first-time researchers make in understanding and implementing the theory of particle filtering. We also discuss and demonstrate the use of particle filtering in nonlinear state estimation applications. We conclude the primer by providing an implementable version of MATLAB code for particle filters. The code not only aids in improving the understanding of particle filters, it also serves as a template for building and implementing advanced nonlinear state estimation routines. © 2016 Elsevier Ltd


Dutta S.,Indian Central Mechanical Engineering Research Institute | Pal S.K.,IIT KharagpurWB | Sen R.,Indian Central Mechanical Engineering Research Institute
Measurement: Journal of the International Measurement Confederation | Year: 2016

In this paper, a method for on-machine tool progressive monitoring of tool flank wear by processing the turned surface images in micro-scale has been proposed. Micro-scale analysis of turned surface has been performed by using discrete wavelet transform. A novel methodology for proper selection of mother wavelets and its decomposition level dependent on the feed rate parameter has also been shown in this research. The selected mother wavelets are utilized to decompose the turned surface images at the chosen decomposition level and two features, namely, GRMS and Energy are extracted as the highly repeatable descriptors of tool flank wear. An exponential correlation of GRMS and Energy values with progressive tool flank wear are found with average coefficient of determination values as 0.953 and 0.957, respectively. © 2015 Elsevier Ltd. All rights reserved.

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