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Your search keyword '"Sivan, Vijay"' showing total 12 results
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12 results on '"Sivan, Vijay"'

2. Highly-Efficient Selective Metamaterial Absorber for High-Temperature Solar Thermal Energy Harvesting

Author

Wang, Hao, Sivan, Vijay Prasad, Mitchell, Arnan, Rosengarten, Gary, Phelan, Patrick, and Wang, Liping

Subjects
Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics, Physics - Optics
Abstract

In this work, a metamaterial selective solar absorber made of nanostructured titanium gratings deposited on an ultrathin MgF2 spacer and a tungsten ground film is proposed and experimentally demonstrated. Normal absorptance of the fabricated solar absorber is characterized to be higher than 90% in the UV, visible and, near infrared (IR) regime, while the mid-IR emittance is around 20%. The high broadband absorption in the solar spectrum is realized by the excitation of surface plasmon and magnetic polariton resonances, while the low mid-IR emittance is due to the highly reflective nature of the metallic components. Further directional and polarized reflectance measurements show wide-angle and polarization-insensitive high absorption within solar spectrum. Temperature-dependent spectroscopic characterization indicates that the optical properties barely change at elevated temperatures up to 350{\deg}C. The solar-to-heat conversion efficiency with the fabricated metamaterial solar absorber is predicted to be 78% at 100{\deg}C without optical concentration or 80% at 400{\deg}C with 25 suns, and could be further improved with better fabrication processes and geometric optimization during metamaterial design. The strong spectral selectivity, favorable diffuse-like behavior, and excellent thermal stability make the metamaterial selective absorber promising for significantly enhancing solar thermal energy harvesting in various system at mid to high temperatures., Comment: 22 pages, 6 figures

Published
2014
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8. Liquid Metal/Metal Oxide Frameworks with Incorporated Ga2O3 for Photocatalysis

Author

Zhang, Wei, primary, Naidu, Boddu S., additional, Ou, Jian Zhen, additional, O’Mullane, Anthony P., additional, Chrimes, Adam F., additional, Carey, Benjamin J., additional, Wang, Yichao, additional, Tang, Shi-Yang, additional, Sivan, Vijay, additional, Mitchell, Arnan, additional, Bhargava, Suresh K., additional, and Kalantar-zadeh, Kourosh, additional

Published
2015
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11. Liquid Metal Actuator for Inducing Chaotic Advection.

Author

Tang, Shi‐Yang, Sivan, Vijay, Petersen, Phred, Zhang, Wei, Morrison, Paul D., Kalantar‐zadeh, Kourosh, Mitchell, Arnan, and Khoshmanesh, Khashayar

Subjects
*LIQUID metals, *ACTUATORS, *CHAOS theory, *ADVECTION, *MARANGONI effect
Abstract

Chaotic advection plays an important role in microplatforms for a variety of applications. Currently used mechanisms for inducing chaotic advection in small scale, however, are limited by their complicated fabrication processes and relatively high power consumption. Here, a soft actuator is reported which utilizes a droplet of Galinstan liquid metal to induce harmonic Marangoni flow at the surface of liquid metal when activated by a sinusoidal signal. This liquid metal actuator has no rigid parts and employs continuous electrowetting effect to induce chaotic advection with exceptionally low power consumption. The theory behind the operation of this actuator is developed and validated via a series of experiments. The presented actuator can be readily integrated into other microfluidic components for a wide range of applications. [ABSTRACT FROM AUTHOR]

Published
2014
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12. Liquid Metal/Metal Oxide Frameworks with Incorporated Ga2O3for Photocatalysis

Author

Zhang, Wei, Naidu, Boddu S., Ou, Jian Zhen, O’Mullane, Anthony P., Chrimes, Adam F., Carey, Benjamin J., Wang, Yichao, Tang, Shi-Yang, Sivan, Vijay, Mitchell, Arnan, Bhargava, Suresh K., and Kalantar-zadeh, Kourosh

Abstract

Solvothermally synthesized Ga2O3nanoparticles are incorporated into liquid metal/metal oxide (LM/MO) frameworks in order to form enhanced photocatalytic systems. The LM/MO frameworks, both with and without incorporated Ga2O3nanoparticles, show photocatalytic activity due to a plasmonic effect where performance is related to the loading of Ga2O3nanoparticles. Optimum photocatalytic efficiency is obtained with 1 wt % incorporation of Ga2O3nanoparticles. This can be attributed to the sub-bandgap states of LM/MO frameworks, contributing to pseudo-ohmic contacts which reduce the free carrier injection barrier to Ga2O3.

Published
2015
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