(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

Corrosion Experiments were carried out under iron carbonate scale-forming conditions in a large diameter, multiphase flow system. Both oil/water and oil/water/gas slug flows were studied at pressures up to 0.79 MPa and temperatures of 60 °C and 80 °C. It was found that with increasing iron concentration, the corrosion rates were reduced to negligible values in oil/water flows. However, significant corrosion was seen in slug flow with clear evidence of damage to the corrosion product layer due to impact and possible collapse of gas bubbles and a considerable reduction in the layer thickness. Details of corrosion rates and corrosion coupon surface analysis are presented. © 1999 by NACE International.

Electrical Engineering

World University root node

NACE - International Corrosion Conference Series

Effect of multiphase slug flow on the stability of corrosion product layer

We investigate the memory system performance of several algorithms for transposing an N × N matrix in-place, where N is large. Specifically, we investigate the relative contributions of the data cache, the translation lookaside buffer, register tiling, and the array layout function to the overall running time of the algorithms. We use various memory models to capture and analyze the effect of various facets of cache memory architecture that guide the choice of a particular algorithm, and attempt to experimentally validate the predictions of the model. Our major conclusions are as follows: limited associativity in the mapping from main memory addresses to cache sets can significantly degrade running time; the limited number of TLB entries can easily lead to thrashing; the fanciest optimal algorithms are not competitive on real machines even at fairly large problem sizes unless cache miss penalties are quite high; low-level performance tuning 'hacks', such as register tiling and array alignment, can significantly distort the effects of improved algorithms; and hierarchical non-linear layouts are inherently superior to the standard canonical layouts (such as row- or column-major) for this problem.

IEEE High-Performance Computer Architecture Symposium Proceedings

Cache-efficient matrix transposition

Hazardous wastes, once generated, have to be stored, transported, treated, disposed off, recycled, depending upon the situation. With laws being tightened, all of the above operations have to be done safely without causing harm to people and environment. Before any operation is carried out, it is vital to know the hazardous characteristics of the waste to be handled. Because waste, generally, is a mixture instead of a pure compound, its hazardous characteristics are difficult to determine and generalize because each waste is specific. A new Hazardous Waste Index (HWI) is proposed in this paper. The index measures hazards related to flammability, reactivity, toxicity and corrosivity as well as the pH value for a hazardous waste. Two examples are given for its use. The index can be modified to include radioactive or mixed waste. Copyright (C) 1999 Elsevier Science B.V. Hazardous wastes, once generated, have to be stored, transported, treated, disposed off, recycled, depending upon the situation. With laws being tightened, all of the above operations have to be done safely without causing harm to people and environment. Before any operation is carried out, it is vital to know the hazardous characteristics of the waste to be handled. Because waste, generally, is a mixture instead of a pure compound, its hazardous characteristics are difficult to determine and generalize because each waste is specific. A new Hazardous Waste Index (HWI) is proposed in this paper. The index measures hazards related to flammability, reactivity, toxicity and corrosivity as well as the pH value for a hazardous waste. Two examples are given for its use. The index can be modified to include radioactive or mixed waste.

Chemical Engineering

Journal of Hazardous Materials

A new Hazardous Waste Index

The design, fabrication, and testing of a fractional h.p. permanent magnet synchronous motor (PMSM) are reported in this paper. The stator has been fitted with a balanced three-phase mush winding. Moreover, the performance analysis using Maxwell Field Simulator has been included. The test results of the motor with a fan load confirms the satisfactory operation of the machine designed in this paper. © 1999 Taylor & Francis.

Electric Machines and Power Systems

Design of a permanent magnet synchronous motor

Multiphase oil/water/gas flow regime transition studies are carried out in a 10-cm Id., 18-m long pipe at inclinations of ±2 deg at system pressures between 0 to 0.79 MPa. The results are compared to those of other researchers, and the ejfects of pressure, inclination, and liquid viscosity are shown. The water cut of the liquid has some effects on the transition from stratified to slug flow. Increasing the water cut results in the transition occurring at higher liquid velocity at the same gas velocity. Water cut has little effect on the slug/annular transition for low viscosity oil used. The system pressure has a moderate effect on the transition from stratified to slug and slug to annular. For the transition from stratified to slug, increasing the system pressure requires higher liquid velocity. The transition from slug to annular occurs at lower liquid velocity with increasing the system pressures. The inclination of the pipe has little effect on the transition from slug to annular flow. Increasing the inclination causes the transition to occur at approximately the same gas velocity at the same liquid velocity. The experimental results show a good agreement with Wilkens' model. © 1999 by ASME.

Journal of Energy Resources Technology, Transactions of the ASME

Investigation of flow regime transitions in large-diameter inclined pipes

This paper presents results of an imidazoline based inhibitor using the Electrochemical Noise (ECN) and Electrochemical Impedance Spectroscopy (EIS) techniques in a multiphase flow pipeline. ECN and EIS measurements were made simultaneously in a 101.6mm I.D., 15m long acrylic pipeline using saltwater and carbon dioxide mixtures. Full pipe flow was studied for liquid velocity of 1.25 m/s and slug flow for Froude numbers 6 and 9. Experiments were carried out at a constant pressure of 136kPa and temperature of 40°C. The ECN signals and EIS spectra of blank and inhibition tests were obtained. The ECN technique is able to monitor the inhibitor film formation continuously. The current noise fluctuation is correlated to the corrosion rate for both blank test and inhibitor test. The higher current fluctuation indicates higher corrosion rates. Different EIS spectra were obtained for blank and inhibitor studies. The simple charge transfer process was seen to occur for blank tests while charge transfer and diffusion processes were taking place under inhibitor effects. © 1999 by NACE International.

Electrochemical methods for monitoring performance of corrosion inhibitor under multiphase flow

Fulltext

Green Chemistry

Inherently safer design-a course for sciene and engineering students

A study of corrosion for high pressure, large diameter pipelines under horizontal and 2 degrees oil/water/gas multiphase flow conditions was carried out. The water cuts studied were 10%, 20% and 30% ASTM saltwater. A light oil with viscosity of 2 cP was used as the oil phase. Carbon dioxide was used in the gas phase. The predominant flow was found to be slug flow and all corrosion experiments were carried out in this regime. Finally, the resulting data was analyzed.

Proceedings - SPE Annual Technical Conference and Exhibition

Study of sweet corrosion at low water cut in multiphase pipelines

Multiphase oil/water/gas flow regime transition studies are carried out in a 10-cm I.D., 18-m long Plexiglas pipe at inclinations of ±2° at system pressures up to 0.79 MPa. The results are compared to those of other researchers, and the effects of pressure, inclination and liquid viscosity are shown. The water cut of the liquid has some effects on the transitions from stratified to slug flow. Increasing the water cut results in the transition occurring at higher liquid velocity at the same gas velocity. Water cut has little effect on the slug/annular transition for the low viscosity oil used. The system pressure has a small effect on the transition from stratified to slug and slug to annular. For the transition from stratified to slug, increasing the system pressure, requires higher liquid velocity. The transition from slug to annular occurs at lower liquid velocity with increasing system pressures. The inclination of the pipe has an effect on the transition from slug to annular flow. Increasing the inclination causes the transition to occur at lower gas velocity at the same liquid velocity.

American Society of Mechanical Engineers, Petroleum Division (Publication) PD

Modeling flow regime transitions in large diameter inclined pipelines

This paper presents a new family of circuits for single phase diode bridge rectifiers capable of drawing approximately sinusoidal current at unity power factor with high efficiency and minimum voltage stress across the switches. They can work as either boost or flyback converters. The circuits consist of a single-phase diode bridge rectifier, followed by a boost stage containing two switches-the main switch for controlling the output DC voltage and the auxiliary for achieving zero voltage switching (ZVS). The switching frequency of the converters is maintained constant. The paper explains the principle of operation and describes the analysis of each mode of operation for both boost and flyback converters. It also gives design criteria, derived from the mathematical analysis carried out, for achieving ZVS under all loading conditions. The simulation results obtained using PSPICE demonstrate the validity of the proposed converters.