Electrical Engineering

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Barriers to the industrial implementation of optical interconnects on an IC, center around the fabrication of optical elements on wafers through conventional Si processes. This paper focuses on demonstrating an all Si-based optical interconnect system that can be easily integrated into a conventional Si process. Most other approaches for optical interconnects use emitters that require drastic changes in conventional fabrication process. In this work, we demonstrate the ability to transmit electrical signals using Si-based system i.e. the light was generated by biasing the Si LED at avalanche breakdown voltage, light was coupled through a fiber cable made of SiO2 and inserted into a Si based avalanche photo-diode. Results presented demonstrate the switching behavior of Si LED in the GHz range, transmission of signal across the fiber, and measurement of signal limited by the BW of the receiver amplifier. © 2000 IEEE.

World University root node

(SoE) School of Engineering

Proceedings of the IEEE 2001 International Interconnect Technology Conference, IITC 2001

All Si-based optical interconnect for signal transmission

The paper reports the study of vibrations occurring in a thin silicon membrane of a conventional capacity pressure sensor. The 20 μ-thick silicon membrane has an area of 6×6 mm. Vibrations induced on the membrane with the help of electrical excitation were studied using a heterodyne laser probe. The probe output gives a measure of the amplitude of vibration of the membrane. Using this technique spatial response of the capacitive pressure sensor diaphragm has been carried out. The resonant frequency peaks of the membrane were measured and the effect of air pressure loading observed.

Journal of the Indian Institute of Science

Laser probing of micromachined capacitive pressure sensor silicon membrane

Silicon p-n junction biased in avalanche breakdown emit visible light and its integration offer 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, DC excitation and increased temperature to accelerate the aging. The results clearly show that the effects of AC, temperature stressing are negligible on light emission. DC stressing results in light coalescence for low values of current (less than 25mA) with total light emission coming out of the junction remaining constant. However, for DC stressing with large current (larger than 40mA) there is no significant variation of light emission. Changes in the light emission behavior for large and small values of DC excitations are consistent with a hydrogen migration model. The study revealed a strong dependence of light emission on the layout of test devices.

Annual Proceedings - Reliability Physics (Symposium)

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

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.

IEEE International Reliability Physics Symposium Proceedings

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.

Materials and Corrosion

Effect of oil in multiphase flow on corrosion product film in large horizontal pipeline

This communication reports the effects of multiphase flow on the corrosion product formed on the surface of 1018 C-steel coupons in oil and gas lines in presence of inhibitor oleic imidazoline. Both bulk and surface analytical techniques reveal the presence of FeCO3, a classic example of CO2 corrosion. While significant changes in the surface morphology with flow condition are monitored by SEM and OM, detailed AES and XPS analysis show the deterioration of inhibitor chemistry as the flow is increased from full pipe (Fr = 0) to slug flow (Fr = 6). XPS shakeup satellite lines in the N (1s) spectra have been useful in the analysis. (C) 2000 Elsevier Science Ltd. All rights reserved. This communication reports the effects of multiphase flow on the corrosion product formed on the surface of 1018 C-steel coupons in oil and gas lines in presence of inhibitor oleic imidazoline. Both bulk and surface analytical techniques reveal the presence of FeCO3, a classic example of CO2 corrosion. While significant changes in the surface morphology with flow condition are monitored by SEM and OM, detailed AES and XPS analysis show the deterioration of inhibitor chemistry as the flow is increased from full pipe (Fr = 0) to slug flow (Fr = 6). XPS shakeup satellite lines in the N (1s) spectra have been useful in the analysis.

Effect of multiphase flow on corrosion of C-steel in presence of inhibitor: A surface morphological and chemical study

A 0.1-m ID acrylic pipe, with four 36-inch radius 90° sweep, clear PVC bends test facility has been constructed to allow for visualization of flow characteristics in hilly terrain and topographies with short elevation changes. The height of the riser and crossing length is 5 meters. A detailed visualization of multiphase flow regimes and flow characteristics using water-carbon dioxide mixtures has been carried out. Visual observations of enhanced turbulence regions were noted and characteristics were noted at different velocities for nine locations along the system. ER probes are used to monitor corrosion rates in the first two bends where elevated turbulence was noted. Corrosion rates observed in the bends are compared to previous rates recorded in horizontal pipelines under similar operating conditions. © 2000 by NACE International.