(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

We describe an efficient parallel algorithm for hidden-surface removal for terrain maps. The algorithm runs in O(log4 n) steps on the CREW PRAM model with a work bound of O((n + k) polylog(n)) where n and k are the input and output sizes, respectively. In order to achieve the work bound we use a number of techniques, among which our use of persistent data structures is somewhat novel in the context of parallel algorithms.

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Algorithmica (New York)

An efficient output-size sensitive parallel algorithm for hidden-surface removal for terrains

Chemical Engineering

Journal of Hazardous Materials

Current status of Inherently Safer Design (ISD) use.

Canadian Journal of Chemical Engineering

Letter to the editor

Hydrocarbon Processing

Inherently safer design [1]

A silicon p-n junction biased in avalanche breakdown emits visible light and its integration offers the potential for VLSI-compatible optical interconnect systems, enabling next generation technologies and/or contact-less functional testing. The Si light emitters were stressed with AC and DC excitation and increased temperature to accelerate the aging. The results clearly show that the effects of AC and temperature stressing are negligible on light emission. DC stressing results in light coalescence for low values of current (<25 mA) with total light emission from the junction remaining constant. However, for DC stressing with large current (>40 mA), there is no significant variation of light emission. Changes in the light emission behavior for large and small values of DC excitation are consistent with a hydrogen migration model. The study revealed a strong dependence of light emission on the layout of test devices. © 2001 IEEE.

Electrical Engineering

IEEE International Reliability Physics Symposium Proceedings

Accelerated stressing and degradation mechanisms for Si-based photo-emitters

In this paper we focus on the problem of designing very fast parallel algorithms for constructing the upper envelope of straight-line segments that achieve the O(n logH) work-boundfor input size n and output size H. Our algorithms are designed for the arbitrary CRCW PRAM model. We first describe an O(log n ・ (logH + log log n)) time deterministic algorithm for the problem, that achieves O(n logH) work boundfor H = Ω(log n). We present a fast randomized algorithm that runs in expectedtime O(logH ・ log log n) with high probability andd oes O(n logH) work. For logH = Ω(log log n), we can achieve the running time of O(logH) while simultaneously keeping the work optimal. We also present a fast randomized algorithm that runs in ˜O(log n/ log k) time with nk processors, k > logΩ(1) n. The algorithms do not assume any input distribution andthe running times holdwith high probability. © Springer-Verlag Berlin Heidelberg 2001.

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

Optimal, output-sensitive algorithms for constructing upper envelope of line segments in parallel

The properties of corrosion product film formed on carbon steel in CO2-containing saltwater under the full pipe flow are examined by A. C. impedance methods. The effect of liquid velocity on the corrosion product film is discussed in this work. It is found that, for each velocity, there is a potential above which a diffusion process occurs on the electrode, and the Warburg impedance coefficient increases with increasing potential. It is suggested that the corrosion product film formed on the surface of the steel is porous, and the diffusion process occurs through the pores of the film. By calculation of the Warburg impedance coefficient (σ), the critical potential (Ef) for the formation of the corrosion film is estimated. It is observed that, below the velocity of 1.25m/s, Ef decreases with increasing flow velocity. On the contrary, at velocities above 1.25m/s, Ef increases with increasing flow velocity. It is considered that, at low velocities, the iron dissolution increases with increasing velocity, so high iron dissolution leads to high possibility for formation of corrosion product film. However, at very high velocity, i. e. above 1.25m/s, because the shear stress at the surface of the pipeline becomes much high, the iron ions from corrosion are removed away from the metal surface, thus forming a film at the metal surface becomes difficult. © 2000 by NACE International.

NACE - International Corrosion Conference Series

Eis study of corrosion product film in Pipelines

This paper addresses the problem of determining H∞ optimal output feedback controllers for a large class of partially observed nonlinear systems. With an eye toward digital implementation, our approach to implementing H∞ output feedback controllers has emphasized issues like reasonable computational complexity, knowledge of observable quantities only, and implementability in finite time. Examples have been provided to investigate the robustness properties of the controllers we have developed. Through direct simulation we have demonstrated that the controller has been observed to be locally stabilizing and robust to noise for systems with even a large degree of nonlinearity.

Proceedings of the IEEE International Conference on Industrial Technology

Robust certainty equivalence controller for discrete-time nonlinear systems

EIS studies of an imidazoline-based inhibitor under multiphase flow conditions were conducted in a large diameter flow loop system. The Warburg diffusion parameter, b(f) = σω(- 1/2) was used to qualitatively analyze inhibitor films formed on the metal surface. Experimental results show that the inhibitor films become less porous with increase in exposure time and inhibitor concentration. Inhibition performance of the corrosion inhibitor is reduced in slug flow at high rate of turbulence and bubble impact. This study demonstrates that EIS is an effective technique to investigate the inhibition performance of corrosion inhibitors in turbulent flow conditions. (C) 2000 Elsevier Science Ltd. All rights reserved.

Corrosion Science

EIS studies of a corrosion inhibitor behavior under multiphase flow conditions

The properties of corrosion product film formed on carbon steel pipelines under saltwater-oil-CO2 multiphase flow were examined by AC impedance methods. Experiments were made in a 101.6 cm ID 10 m long pipe. Experimental results showed that there are two reactions on the steel surface in a saltwater-oil mixture. One is charge transfer and the other is diffusion. By calculation of the charge transfer resistance, Rt, and Warburg impedance coefficient, σ, it is found that Rt in a saltwater-oil mixture is much higher than that in saltwater. In a saltwater-oil mixture, Rt and σ increase with immersion time. It is suggested that the porous corrosion film occurs on the surface of the steel and that the film becomes compact when the immersion time increases. The longer the exposure time, the more compact the film, resulting in a lower corrosion rate. Corrosion in carbon steel pipelines under multiphase flow has long been a problem in the oil industry.