Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Engineering
Electromagnetic Modeling Of Saltwater Ingress In Mortar At Microwave Frequencies, Shanup Peer, R. Zoughi, K. E. Kurtis
Electromagnetic Modeling Of Saltwater Ingress In Mortar At Microwave Frequencies, Shanup Peer, R. Zoughi, K. E. Kurtis
Electrical and Computer Engineering Faculty Research & Creative Works
Corrosion of reinforcing steel is a major cause of damage and deterioration in reinforced concrete structures. Therefore, as the presence of a sufficient concentration of chloride ions can lead to the onset of corrosion in embedded steel, it is of utmost importance to be able to determine the free salt content and its distribution in these materials. Moreover, it is important to obtain this information nondestructively. Previous investigations have shown the capability of near-field microwave nondestructive evaluation methods, using open-ended rectangular waveguide probes, to evaluate many important properties of cement-based materials. In this Investigation, the temporal microwave reflection properties of …
Microwave Reflection Properties Of Concrete Exposed Periodically To Chloride Solution Of 3% Salinity And Compression Force, Joseph Toby Case, Eric Gallaher, Shanup Peer, R. Zoughi
Microwave Reflection Properties Of Concrete Exposed Periodically To Chloride Solution Of 3% Salinity And Compression Force, Joseph Toby Case, Eric Gallaher, Shanup Peer, R. Zoughi
Electrical and Computer Engineering Faculty Research & Creative Works
Microwave nondestructive evaluation (NDE) techniques applied to mortar have proven successful in the past for detecting mixture constitutes, salt ingress, loading and cure state monitoring. In this paper, a similar microwave NDE technique is used to evaluate reflection properties of concrete for cyclical exposure to salt ingress and loading at S-(2.6-3.95 GHz) and X-(8.2-12.4GHz) microwave frequency bands. Four identical cubic specimens were prepared: one soaked in distilled water, one soaked in a 3%-salt solution, one soaked in a 3%-salt solution and loaded and finally one that was neither soaked nor loaded. Using both magnitude and phase of microwave reflection coefficient, …
Algan/Gan Heterostructure Field-Effect Transistors On Single-Crystal Bulk Aln, X. Hu, J. Deng, N. Pala, R. Gaska, M. S. Shur, C. Q. Chen, J. Yang, Grigory Simin, M. A. Khan, J. C. Rojo, L. J. Schowalter
Algan/Gan Heterostructure Field-Effect Transistors On Single-Crystal Bulk Aln, X. Hu, J. Deng, N. Pala, R. Gaska, M. S. Shur, C. Q. Chen, J. Yang, Grigory Simin, M. A. Khan, J. C. Rojo, L. J. Schowalter
Faculty Publications
We report on the performance of AlGaN/GaN/AlN heterostructurefield-effect transistors(HFETs) grown over slightly-off c-axis, single-crystal, bulk AlN substrates. Dc and rf characteristics of these devices were comparable to HFETs grown on semi-insulating SiC. The obtained results demonstrate that bulk AlN substrates are suitable for fabricating high-power microwave AlGaN/GaN transistors.
Microwave Reflection And Dielectric Properties Of Mortar Subjected To Compression Force And Cyclically Exposed To Water And Sodium Chloride Solution, Shanup Peer, Joseph Toby Case, Eric Gallaher, K. E. Kurtis, R. Zoughi
Microwave Reflection And Dielectric Properties Of Mortar Subjected To Compression Force And Cyclically Exposed To Water And Sodium Chloride Solution, Shanup Peer, Joseph Toby Case, Eric Gallaher, K. E. Kurtis, R. Zoughi
Electrical and Computer Engineering Faculty Research & Creative Works
Corrosion of the reinforcing steel is a major cause of damage and deterioration in reinforced concrete structures such as concrete bridge decks and columns. Chloride intrusion into concrete can lead to depassivation of the steel and initiation of corrosion. Thus, it is very important to be able to nondestructively detect and evaluate the free chloride content in concrete. Near-field microwave nondestructive testing techniques, using open-ended rectangular waveguide probes, have shown great potential for evaluating various properties of concrete, including the successful detection of sodium chloride added to mortar mixing water. In this study, several mortar samples are cyclically soaked in …