(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

In the present study, photocatalytic oxidation of dye bearing wastewater has been done using iron doped zinc oxide (Fe/ZnO) photocatalyst. Various photocatalysts were synthesized by solution combustion synthesis method, and their structural, morphological, and optical properties were studied using N2 adsorption-desorption, Fourier transform infrared spectroscopy, X-ray diffractometer, thermogravimetric analysis, field emission scanning electron microscope, transition electron microscope, and UV-visible diffuse reflectance spectra. Effect of various parameters such as the amount of iron doped, calcination temperature, calcination time, pH of the dye solution, catalyst dose, hydrogen peroxide dose, reaction temperature, and initial concentration of the dye solution were optimized. At optimum conditions, more that 71% color removal, 94% dye degradation, and 41% total organic carbon removal was observed for acid red 1 dye solution having an initial concentration of 50 mg/L and initial color of 2730 Pt:Co units. © 2013 American Chemical Society.

Chemical Engineering

World University root node

Industrial and Engineering Chemistry Research

Photocatalytic oxidation of dye bearing wastewater by iron doped zinc oxide

Given a set of points Q on a road network G = (V,E), an optimal meeting point (OMP) query offers a point on a road network with the smallest sum-of-distances (SoD) to all the points in Q. For example, a travel agency may issue OMP query to decide the location for a tourist bus to pick up the tourists thus minimizing the total travel cost for tourist. The OMP problem has been well studied in the Euclidean space. The currently available algorithms for solving this problem in the context of road networks are still not efficient for the practical applications and are in-memory algorithms which do not guarantee the scalability for the large road databases. Further, the most of the research work has been carried out around the single point OMP; however, the k-OMP problem on the road network setting is still unexplored. In this paper, we are proposing multiple variants of the scalable external-memory based algorithms for computing the optimal meeting point. There are mainly three variants of the proposed grid based algorithms i.e. Basic Grid based, Hierarchical Grid based and Greedy Centroid based OMP search. Later we used single point OMP as a start point to explore the k points OMP using breadth first search. The I/O optimized spatial grids are loaded from the secondary storage as and when required and hence the I/O complexity is reduced to O(N/B) as opposed to O(N) in the existing methods; where B is the average number of road vertices of the grid block. Extensive experiments are conducted on both real and synthetic datasets. © 2013 Springer-Verlag Berlin Heidelberg.

Computer Science and Engineering

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

Scalable Method for k Optimal Meeting Points (k-OMP) Computation in the Road Network Databases

Slurry erosion is a major problem in hydroturbines and other fluid machineries wherein erodent particles entrained in carrier fluid impinge upon the target surface to cause its degradation. Several possible alternative solutions are available to control slurry erosion; however, surface coatings developed using thermal spraying are mostly used owing to their versatile nature. In this work, Ni based thermal spray coatings were deposited on a commonly used hydroturbine steel (CA6NM), with Al2O3 mixed in different proportions. Coatings were developed using high velocity flame spray process (HVFS). Slurry erosion performance of prepared coated and bare steel was investigated using a specially designed jet type test rig with sand as erodent particles. To investigate the effect of concentration on erosion behavior, sand was mixed in water at two different levels, 0.1 wt % and 0.5 wt. %. It was observed that all the coatings helped in improving the erosion resistance of the steel with one containing 40 wt % Al2O3 showing the maximum improvement. This was related to the microstructure, which controlled the micro hardness and fracture toughness of the coatings. Shielding effect of the rebounding particles was found to have profound effect as erosion rates did not show similar augmentation with concentration. Fracturing of alumina phase along with removal of coating in form of splats was observed to be prominent erosion mechanism. © 2013 The Authors. Published by Elsevier.

Mechanical Engineering

Fulltext

Procedia Engineering

Slurry erosion of thermal spray coatings: Effect of sand concentration

In the current work, Ni-Al2O3 based composite coatings were fabricated using High Velocity Flame Spray (HVFS) system. The effect of alumina content on the microstructure and various mechanical properties viz. microhardness, fracture toughness, density, residual stress and scratch resistance was studied. Microstructure of the coating was characterized with the help of Scanning Electron Microscope (SEM) equipped with Energy Dispersive Spectroscopy (EDS), Optical Microscope (OM) and X-ray Diffraction (XRD). It was observed that microstructural properties such as splat size, porosity, un-melted particles and surface roughness are highly affected by the alumina content in the coatings. Microhardness improved with the rise in alumina fraction and a maximum of 1151HV could be achieved with 60wt.% alumina blending. Cracking and spallation were found to be the mechanisms responsible for damage of coatings during scratch testing. A model has been proposed to explain the variation in surface roughness and porosity of the Ni-Al2O3 coatings based on coating build-up mechanism. © 2012 Elsevier B.V.

Surface and Coatings Technology

Microstructural and mechanical characterization of thermal sprayed nickel-alumina composite coatings

The design, synthesis and characterization of five diphenylhydrazone end capped molecules as donors for Bulk Heterojunction (BHJ) solar cells are described. The use of the hydrazone donor instead of the more common amine one is advantageous in terms of synthetic access and overall stability. We show that the variation of both the nature and the substitution pattern of the electron deficient conjugated bridge enables the tuning of the optical energy gap as well as of the HOMO and LUMO. In particular, our data show that the low energy shift of the HOMO level along the series of hydrazone compounds, one of the critical parameters affecting the performance of BHJ cells, is as high as 0.42 eV. We tested all derivatives as donors in a BHJ configuration, using the fullerene derivative [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as the acceptor. We found that the trend we observed in the progressive stabilization of the chromophore HOMO level upon increasing the electron accepting capabilities of the conjugated bridge is reflected in the progressive increase of the cell open circuit voltage (Voc). Our preliminary results show that it is possible to obtain a Vocas high as 0.74 V, along with a power conversion efficiency of 1.2%. © 2013 The Royal Society of Chemistry.

Electrical Engineering

Journal of Materials Chemistry A

Open circuit voltage tuning through molecular design in hydrazone end capped donors for bulk heterojunction solar cells

In this paper a Fast Array Multichannel Two-Dimensional Recursive Least Square (FAM 2D-RLS) adaptive filter is proposed for estimating an OFDM channel in frequency domain. This filter makes use of the shift structure of the input data vector. Thus the computational cost of the classical RLS filter which is O(M 2) is reduced to O(M) for each iteration where M is the order of the filter. In order to ensure numerical stability in finite precision, we make use of array-based methods for implementing FAM 2D-RLS. The adaptive filters illustrated in the standard literature consist of a weight vector and desired data as a scalar. But in our scenario of OFDM channel estimation the weight is a matrix while the desired data are a vector. Hence the algorithm for the matrix form of FAM-2D RLS and its steady state equations are derived. Numerical stability, steady state and convergence performance are verified using MATLAB simulations. © 2012 Springer Science+Business Media New York.

Circuits, Systems, and Signal Processing

Fast array multichannel 2D-RLS based OFDM channel estimator

Mobile Agent (MA) based distributed computing paradigm offers numerous benefits over the existing and commonly used client/server computing paradigm in wireless sensor networks (WSN). MA performs the task of data processing and data aggregation at the node level rather than at the sink, thus, eliminating the redundancy network overhead. One of the most important issues in MA based paradigm is planning of an itinerary (route) for MA traversal. In this paper, we present a centralized MA itinerary planning approach using Grey Relational Analysis (GRA). The residual energy, migration cost and information gain are the factors considered for the next node selection of the itinerary, and GRA is used for finding out their importance level and determine their weighted values. Simulation results exhibit that the GRA based proposed approach performs better than the previously existing approaches. © 2013 IEEE.

2013 6th International Conference on Contemporary Computing, IC3 2013

Itinerary planning using grey relational analysis for mobile agent based wireless sensor networks

A microstructure-based internal state variable (ISV) plasticity-damage model was used to model the mechanical behavior of a porous FC-0205 steel alloy that was procured via a powder metal (PM) process. Because the porosity was very high and the nearest neighbor distance (NND) for the pores was close, a new pore coalescence ISV equation was introduced that allows for enhanced pore growth from the concentrated pores. This coalescence equation effectively includes the local stress interaction within the interpore ligament distance between pores and is physically motivated with these highly porous powder metals. Monotonic tension, compression, and torsion tests were performed at various porosity levels and temperatures to obtain the set of plasticity and damage constants required for model calibration. Once the model calibration was achieved, then tension tests on two different notch radii Bridgman specimens were undertaken to study the damage-triaxiality dependence for model validation. Fracture surface analysis was performed using scanning electron microscopy (SEM) to quantify the pore sizes of the different specimens. The validated model was then used to predict the component performance of an automotive PM bearing cap. Although the microstructure-sensitive ISV model has been employed for this particular FC-0205 steel, the model is general enough to be applied to other metal alloys as well. © 2013 by ASME.

Journal of Engineering Materials and Technology, Transactions of the ASME

Plasticity and fracture modeling/experimental study of a porous metal under various strain rates, temperatures, and stress states

Performance of Ni-Al2O3 based composite coatings was evaluated under slurry erosion condition. Erosion resistance was correlated with different properties of the coatings. It was observed that fracture toughness is an important parameter that controls the erosion resistance of coatings. Content of alumina was found to have significant influence on the erosion performance and material removal mechanism of the coatings. Erosion rates were predicted using fracture-contact model. The results were observed to lie in close proximity to the experimental results. Cracking and spalling of coating, fracture of reinforcing phase and removal of splats were observed to be the primary erosion mechanisms. © 2013 Elsevier Ltd.

Tribology International

Slurry erosion performance of Ni-Al2O3 based composite coatings

With the development of high resolution infrared cameras, thermography is gaining increased attention of the researcher not merely as a non-contact tool to measure surface temperature of the objects, but also as a tool in fine physical experiments to analyze thermo-physical phenomena. Apart from their regular application in condition monitoring and preventive maintenance, the infrared cameras are slowly finding application in research and development. In the field of textile research, the application of thermal imaging is still at its infancy. Most of the present applications are for qualitative observations of surface temperature profile of the object. In the present paper, various applications of thermography in textiles and allied fields have been reported with a projection of potential future research where thermography may play crucial roles.