(SoE) School of Engineering

<p>Shiv Nadar University is a comprehensive, multidisciplinary, research-focused, and student-centric University offering a full range of academic programs at the undergraduate, postgraduate and doctoral level. With state-of-the-art infrastructure, the University comprises of academic wings, sophisticated labs, international standard sports facilities, amphitheaters, auditorium, conference rooms and smart classrooms. The University&rsquo;s goal is to become internationally recognized for the quality of its research and creative endeavors and their applicability to improving quality of life, generating new insights and expanding the boundaries of human knowledge creativity. Committed to excellence in teaching, research and service, the University aims to serve the higher education needs of India and the world beyond.</p>

Shiv Nadar University

The rapid increase in anthropogenic nitrogen emissions to the atmosphere is matter of concern for the environment, as these may lead to photochemical air pollution, reduced visibility, eutrophication of surface waters, changes in biodiversity, acid rain, stratospheric ozone depletion, and global warming. In this study, ambient emissions of reactive nitrogen (ammonia and nitrous oxide) from animal and crop farming are analyzed for the base year 2003. This objective was achieved by the systematic development of a spatially resolved emissions inventory on a Geographic Information System (GIS) platform. Emissions of ammonia (NH 3) and nitrous oxide (N 2O) were estimated: (i) from livestock; 1705-Gg/yr and 214-Gg-yr -1 and (ii) fertilizer applications; 2697-Gg-yr -1 and 326-Gg-yr -1. These estimated emissions were compared and contrasted with global, U.S., and European emissions of reactive nitrogen; emissions from India were second only to China. From the spatially resolved emission inventory, it was observed that the state of Uttar Pradesh has the highest NH 3 emission (522-Gg-yr -1) followed by the state of Maharashtra (425-Gg-yr -1) both from animal and crop farming. Similarly the State of Uttar Pradesh has the highest N 2O emission (70-Gg-yr -1) followed by the state of Maharashtra (47-Gg-yr -1). © 2011 Elsevier Ltd.

World University root node

Civil Engineering

Fulltext

Atmospheric Environment

Reactive nitrogen emissions from crop and livestock farming in India

Lock-in (LI) thermography is a popular thermal-nondestructive-testing technique which, like other active thermographic techniques, requires an external heating stimulus, preferably on a blackened surface. It is not, however, immune to nonideal situations like nonuniform heating and surface emissivity variation. The phase image, to some extent, helps to reduce the effect of these artifacts but is inadequate if the variations are large. For example, a poorly blackened metallic sample with reflecting patches on its surface is very difficult to actively thermograph because of direct reflection from the surface. This paper proposes an image reconstruction algorithm for offline removal of such artifacts. In addition, the proposed algorithm enables LI thermography tests in the transient regime and removes temperature gradients due to nonuniform heating. The algorithm was tested with a mild-steel sample having 20-mm-diameter back-drilled holes at various depths ranging from 0.2 to 7.7 mm, stimulated at 20-, 40-, 50-, 60-, and 80-mHz excitation frequencies. The effect of the total number of heating cycles is also presented. © 2011 IEEE.

Electrical Engineering

IEEE Transactions on Instrumentation and Measurement

Image enhancement in transient lock-in thermography through time series reconstruction and spatial slope correction

Pulsed thermography (PT), being simple and fast, remains one of the most popular thermographic NDE techniques, though it has intrinsic limitations. An alternative method is suggested and named frequency modulated thermal wave imaging (FMTWI), where the heating waveform phase relations are adjusted over a bandwidth (B) in such a way, that a chirp (frequency modulated) signal of duration T, with much reduced peak power is produced. FMTWI, while retaining all characteristics of lock-in thermography, has the added advantage of overcoming the blind frequency problem. It can be processed by matched filtering (pulse compression) to improve sensitivity. © 2012 American Institute of Physics.

AIP Conference Proceedings

Frequency modulated thermal wave imaging

Materials with improved tribological properties have become the pre-requisite of advanced engineering design. Surface metal matrix composites (SMMCs) exhibit a unified combination of good tribological properties and high toughness of the interior bulk metal when compared with monolithic materials. Friction stir processing, a microstructure modification technique, has emerged as one of the processes used for fabrication of SMMCs. Commercial cast or wrought type Mg-Al- Zn AZ-series alloys, such as AZ91, AZ61 or AZ31 with 3-9 wt.% Al and 1 wt.% Zn, have been widely used in automobiles or electronic appliances. Due to low percentage of alloying elements/second phase elements in these alloys, the grain refinement and hence the mechanical properties such as hardness cannot be appreciably enhanced. In this study, FSP was used to fabricate AZ31 based nanocomposite using TiC as reinforcement. FSP was performed at a fixed volume fraction of TiC under varying cooling conditions. Tribological performance of the fabricated composite was investigated using pin-on-disc wear test arrangement. The analysis of the wear surfaces as well as wear debris analysis was done using SEM equipped with EDS. The fabricated composite was found to exhibit superior wear resistance. © (2012) Trans Tech Publications, Switzerland.

Mechanical Engineering

Advanced Materials Research

Improving the tribological properties of mg based AZ31 alloy using friction stir processing

Hydrotubines do face regular exposure to cavitating environment, causing damage to guide vanes, impeller, nozzle, buckets and spear. Quite a large number of surface modification techniques have been employed to counter such a deleterious effect. Among these large numbers of techniques, thermal spray coatings has been mostly focused and studied. In the present work one such technique has been opted for study. Selection of coating technique and composition was made keeping their economical viability in mind. Hardness and toughness have been identified as significant factors effecting cavitation erosion of materials. In-depth analysis of erosion mechanism of coated and un-coated samples was undertaken using SEM/EDS, micro-hardness tester and XRD. Erosion mechanism of steel was mainly plastic deformation, whereas in case of coating, (i) lack of adhesion between splats (ii) lower toughness of alumina (iii) loosely bonded un-melted alumina particles, were dominant factor controlling the erosion mechanism of coating. © (2012) Trans Tech Publications, Switzerland.

Evaluation and development of economically viable coatings for erosion protection of hydroturbines

A new type of intrinsic photoconductor was used as a donor in bulk heterojunction solar cells, in blends with PCBM. The donor is a square planar cyclopalladated coordination complex, with a Nile red moiety and a Schiff base as ligands, coordinated by a Pd(II) metal center. The photoconducting properties of the complex were characterized. Photovoltaic devices exhibit low performance, but the analysis of the wavelength dependence of the efficiency reveals a much higher photocurrent upon absorption of the complex, when compared to the photocurrent obtained via absorption by PCBM. This effect is tied to the higher tendency of the intrinsic photoconductor towards exciton dissociation at the heterojunction. © 2012 Copyright Taylor and Francis Group, LLC.

Molecular Crystals and Liquid Crystals

Enhancement of exciton dissociation efficiency in bulk heterojunction solar cells by using an intrinsic photoconductor component

Various OSIC MIMO detectors are considered suboptimal in terms of performance and complexity, however suffers from error propagation. QR-LRL is considered to be most effective to mitigate error performance as it detects the least reliable layer(LRL) symbol first. It achieves hard ML performance, but suffers from empty vector set(EVS) problem for soft output generation. Some of the previous work mitigates this problem effectively and achieves soft ML performance at the cost of complexity. QR-LRL based IDD(Iterative Detection and Decoding) is an alternative solution, which exchanges the extrinsic information between detector and decoder. Based on feed back knowledge from decoder, decision is made to update candidate vector set for soft output generation. Simulation results shows that significant performance improvement is achieved while keeping the receiver design simple. © 2012 IEEE.

International Conference on ICT Convergence

Efficiently using extrinsic gain for candidate vectors selection in QR-LRL based IDD MIMO receiver

In this study, AZ91 based hybrid nanocomposite was fabricated using mixture of TiC and alumina by friction stir processing (FSP). FSP of AZ91 was conducted with as well as without particle addition and under different cooling conditions. Distribution of nano TiC and Al2O3 particles in the Mg matrix was studied using SEM. Grain size analysis of the as-cast and FSP AZ91/(TiC +Al2O3) composite was done using optical microscopy. The performance of the fabricated nanocomposite was investigated using microhardness, bulk hardness and scratch tests. Microhardness testing was done at 50 gf load and bulk hardness at 5 Kgf load. Scratch test was performed at 2 and 5 N normal load values on a universal tribometer using Rockwell indentor. AZ91/(TiC+Al2O3) composite exhibited improved mechanical properties.

Transactions of the Indian Institute of Metals

Some investigations on friction stir processed zone of AZ91 alloy

Chemical Engineering

Process Safety and Environmental Protection

Trevor Kletz - Common sense safety star

The present study attempts to screen a number of ionic liquids (ILs) for CO 2 capture and its separation from flue gas mixture based on Hildebrand solubility parameter (δ). Solubility parameters of various ILs have been computed through molecular dynamic simulations in Material Studio. Initially the density and solubility parameters of seven ILs have been validated with experimental values available in the literature and are found to be in close correspondence. A group contribution correlation for δ of IL is developed and expressed as the weighted sum of attractions and repulsions of cation and anion as: δIL2=0.6 δcaδan-0. 2δca2-0.2δan2. This correlation was used to find out the δ values of cation and anion. The solubility parameters of 21 cations and 10 anions have successfully been determined by using δ values of 31 ILs and the correlation. Furthermore, using δ values of 21 cations and 10 anions and the group contribution correlation, the δ values of 210 ILs have been predicted. The δ values obtained by correlation match well with the δ values obtained by direct molecular simulations for twenty seven ILs, suggesting that correlation equation is reliable to predict the δ values of several ILs. Furthermore, comparison of the literature solubility data of different gases in ILs with that of solubility parameters in the present study reveals that the δ values are able to successfully explain the experimental solubility trends. Of all ILs studied, δ values of phosphonium cation based ILs (δ = 20.7-18.3 MPa 0.5) and ILs containing tris(nonafluorobutyl)trifluorophosphate ([bFAP] -) anion (δ = 20.5-18.3 MPa 0.5) are observed to be closer to that of CO 2 (δ = 17.85 MPa 0.5) and are significantly far from that of other flue gases like CH 4, N 2, H 2 and H 2O. Thus, by using the fluorinated anion and phosphonium cation based ILs, CO 2 can be more selectively separated from the major flue gases. © 2012 Elsevier B.V. All rights reserved.