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Reza Zoughi

Bio: Reza Zoughi is an academic researcher from Iowa State University. The author has contributed to research in topics: Nondestructive testing & Dielectric. The author has an hindex of 41, co-authored 369 publications receiving 6480 citations. Previous affiliations of Reza Zoughi include University of Missouri & United States Department of the Navy.


Papers
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Journal ArticleDOI
TL;DR: In this article, the authors focus on three recent applications of microwave and millimeter wave NDTE: corrosion and precursor pitting detection in painted aluminum and steel substrates; and detection of flaws in spray-on foam insulation and the acreage heat tiles of the Space Shuttle through focused and synthetic imaging techniques.
Abstract: This article focuses on three recent applications of microwave and millimeter wave NDTE 2) corrosion and precursor pitting detection in painted aluminum and steel substrates; and 3) detection of flaws in spray-on foam insulation and the acreage heat tiles of the Space Shuttle through focused and synthetic imaging techniques. These applications have been performed at the Applied Microwave Nondestructive Testing Laboratory (amntl) at the University of Missouri-Rolla.

422 citations

Book
01 Jan 2000
TL;DR: In this article, a detailed dielectric composite evaluation is presented, along with a surface crack detection approach for near-field measurement techniques and applications, and a survey of the current state of the art is presented.
Abstract: Foreword. 1. Introduction. 2. Microwave characterization. 3. Layered dielectric composite evaluation. 4. Surface crack detection. 5. Near-field measurement techniques and applications. 6. Other developments and future. Index.

338 citations

Journal ArticleDOI
TL;DR: In this article, a modification to this measurement technique utilizing two dielectric plugs which are used to house the granular or liquid materials was described, where no approximation to the measurement apparatus is made while the presence of the plugs are fully accounted for in the derivations.
Abstract: There are numerous dielectric property characterization techniques available in the microwave regime each with its own uniqueness, advantages and disadvantages. The two-port completely-filled waveguide (transmission line) technique is a robust measurement approach which is well suited for solid dielectric materials. In this case, the dielectric material can be relatively easily machined to fit inside the waveguide and the subsequent measurement of the scattering parameters of this two-port device renders the dielectric properties of the material filling the waveguide. However, this technique is not well suited for measuring the dielectric properties of granular and liquid materials. These materials are used in the production of various composites which are increasingly replacing the use of metals in many environments. If this technique is directly applied to these types of materials, several approximations either in the measurement apparatus or the formulation must be made. To overcome this problem, this paper describes a modification to this measurement technique utilizing two dielectric plugs which are used to house the granular or the liquid dielectric material. In this approach no approximation to the measurement apparatus is made while the presence of the plugs are fully accounted for in the derivations. Using this technique, the dielectric properties of cement powder, corn oil, antifreeze solution and tap water, constituting low- and high-loss dielectric materials (granular and liquid) were measured. In addition, the important issue of measurement uncertainty associated with this technique is also fully addressed. The issue of optimal choice of various measurement parameters is also discussed as it relates to the measurement uncertainty.

122 citations

Journal ArticleDOI
TL;DR: In this paper, a novel microwave technique for detecting long surface cracks in metals is described, which utilizes an open-ended waveguide to probe the surface of a metal, and it is shown that cracks a fraction of a millimeter in width are easily detected at around 20 GHz or lower.
Abstract: A novel microwave technique for detecting long surface cracks in metals is described. This technique utilizes an open-ended waveguide to probe the surface of a metal. In the absence of a crack the metal surface is seen as a relatively good short-circuit load. However, in the presence of a crack higher order modes are generated which in turn change the reflection properties at the waveguide aperture. This change brings about a perturbation in the standing wave characteristics which is then probed by a diode detector. The experimental and theoretical foundations of this technique are given, along with several examples. It is shown that cracks a fraction of a millimeter in width are easily detected at around 20 GHz or lower. Smaller cracks can be detected at higher microwave frequencies. >

118 citations

Journal ArticleDOI
TL;DR: Two new techniques for microwave imaging of layered structures are introduced to address the limiting issues associated with classical synthetic aperture radar (SAR) imaging techniques in generating focused and properly-positioned images of embedded objects in generally layered dielectric structures.
Abstract: In this paper, two new techniques for microwave imaging of layered structures are introduced. These techniques were developed to address the limiting issues associated with classical synthetic aperture radar (SAR) imaging techniques in generating focused and properly-positioned images of embedded objects in generally layered dielectric structures. The first method, referred to as piecewise SAR (PW-SAR), is a natural extension of the classical SAR technique, and considers physical and electrical properties of each individual layer and the discontinuity among them. Although this method works well with low loss dielectric media, its applicability to lossy media is limited. This is due to the fact that this method does not consider signal attenuation. Moreover, multiple reflections within each layer are not incorporated. To improve imaging performance in which these important phenomena are included, a second method was developed that utilizes the Green's function of the layered structure and casts the imaging approach into a deconvolution procedure. Subsequently, a Wiener filter-based deconvolution technique is used to solve the problem. The technique is referred to as Wiener filter-based layered SAR (WL-SAR). The performance and efficacy of these SAR based imaging techniques are demonstrated using simulations and corresponding measurements of several different layered media.

112 citations


Cited by
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01 Jan 2016
TL;DR: The properties of concrete is universally compatible with any devices to read, and is available in the digital library an online access to it is set as public so you can download it instantly.
Abstract: Thank you for downloading properties of concrete. As you may know, people have look hundreds times for their chosen readings like this properties of concrete, but end up in malicious downloads. Rather than reading a good book with a cup of coffee in the afternoon, instead they juggled with some malicious virus inside their computer. properties of concrete is available in our digital library an online access to it is set as public so you can download it instantly. Our digital library hosts in multiple locations, allowing you to get the most less latency time to download any of our books like this one. Merely said, the properties of concrete is universally compatible with any devices to read.

1,701 citations

Journal ArticleDOI
TL;DR: An overview of the main concepts underlying ANNs, including the main architectures and learning algorithms, are presented, and the main tasks that involve ANNs in remote sensing are described.
Abstract: Artificial neural networks (ANNs) have become a popular tool in the analysis of remotely sensed data. Although significant progress has been made in image classification based upon neural networks, a number of issues remain to be resolved. This paper reviews remotely sensed data analysis with neural networks. First, we present an overview of the main concepts underlying ANNs, including the main architectures and learning algorithms. Then, the main tasks that involve ANNs in remote sensing are described. The limitations and crucial issues relating to the application of the neural network approach are discussed. A brief review of the implementation of ANNs in some of the most popular image processing software packages is presented. Finally, we discuss the application perspectives of neural networks in remote sensing image analysis.

465 citations

Journal ArticleDOI
TL;DR: In this article, the authors focus on three recent applications of microwave and millimeter wave NDTE: corrosion and precursor pitting detection in painted aluminum and steel substrates; and detection of flaws in spray-on foam insulation and the acreage heat tiles of the Space Shuttle through focused and synthetic imaging techniques.
Abstract: This article focuses on three recent applications of microwave and millimeter wave NDTE 2) corrosion and precursor pitting detection in painted aluminum and steel substrates; and 3) detection of flaws in spray-on foam insulation and the acreage heat tiles of the Space Shuttle through focused and synthetic imaging techniques. These applications have been performed at the Applied Microwave Nondestructive Testing Laboratory (amntl) at the University of Missouri-Rolla.

422 citations

Journal ArticleDOI
TL;DR: In this article, the most studied type of manufacturing defects, voids, form very often in processing of fiber-reinforced composites and have a considerable influence on physical and thermomechanical properties.
Abstract: Voids, the most studied type of manufacturing defects, form very often in processing of fiber-reinforced composites. Due to their considerable influence on physical and thermomechanical properties ...

404 citations