558 research outputs found

    Microwave Nondestructive Detection and Evaluation of Disbonding and Delamination in Layered-Dielectric Slabs

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    A microwave nondestructive technique for detection and evaluation of disbonding and delamination in layered-dielectric-slabs backed by a conducting plate is discussed. The theoretical development begins by considering an incident wave illuminating such a medium and then formulating the characteristics of the wave reflected by the metal plate. An effective reflection coefficient is determined in this way whose phase characteristics are used in the detection and evaluation of delaminations in the media. The characteristics of this phase as a function of several parameters such as delamination dielectric constant and thickness, slab dielectric constant, and thickness and the frequency of operation are investigated. The description of an experimental apparatus is given and it is used to perform several experiments to test and verify the theory. Very good agreement was obtained between the theoretical and experimental results

    Bakhtiari, Leskinen and Torma Reply

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    This is a Reply to: Comment on "Spectral Signatures of the Fulde-Ferrell-Larkin-Ovchinnikov Order Parameter in One-Dimensional Optical Lattices" R. A. Molina J. Dukelksy, and P. Schmitteckert, Phys. Rev. Lett. 102, 168901 (2009)Comment: 1 page, published versio

    Determination of isolated Aeromonas hydrophila antibiotic resistance profile from farmed common carp (Cyprinus carpio) in Khuzestan Province

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    Aeromonas are an example of emerging bacterial pathogens. Even though they have been recognized as primary fish and human pathogens. Aeromonas hydrophila are opportunistic pathogens that are at the same time infectious and enterotoxigenic and multiple antibiotic resistances (MAR) among Aeromonas hydrophila strains has been reported from many parts of the world. Under these circumstances, it will be worthwhile to find out the prevalence of antibiotic resistance of the Aeromonas hydrophila strains. The one hundred pieces of fish samples were collected from 4 common carp training pool in Khuzestan province. The part of intestine was collected in sterile plate and was homogenized. The samples were cultured in blood agar and incubated in 37centigrade degree temperature. Three to five Aeomonas hydrophila suspected colony, were selected from any plate and purified in blood agar. After initial evaluation of each colony by catalase, oxidase and gram staining, suspected strains DNA was extracted by boiling. Aeromonas hydrophila strains were confirmed by PCR assay and using of genus and species specific primers. Finally, multiple antibiotic resistance (MAR) of confirmed Aeromonas hydrophila isolates was evaluated by Kirby-Bauer disc diffusion method. Twenty Aeromonas hydrophila strains of Aeromonas suspected colonies were confirmed by PCR assay and the most of isolates had a multiple resistance. The least and the most resistance was observed regarding to cefotaxim and ciprofloxacin (<25%), vancomycin and clindamycin (90%), respectively. Compared with results of other studies, antibiotic resistance pattern of these bacterial strains is variable in different geographical areas; therefore resistant pattern of each group of bacteria must be determined in each area

    Open-Ended Rectangular Waveguide for Nondestructive Thickness Measurement and Variation Detection of Lossy Dielectric Slabs Backed by a Conducting Plate

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    Solutions of fields inside a slab of a generally lossy dielectric medium backed by a conducting plate, placed outside a waveguide-fed rectangular aperture, are evoked in the application to the microwave nondestructive thickness measurement of such dielectric slabs. Upon construction of the waveguide terminating admittance expression from its variational form, an inverse problem is then solved to extract the slab thickness from the conductance and susceptance in a recursive manner. A comparison between the experimental and theoretical results showed that the significance of higher order modes is minimal; hence, the dominant mode assumption is, in general, valid to describe the aperture field distribution. The validity of this assumption has led to the construction of a simple integral solution which is fast converging for generally lossy dielectric slabs, and may easily be implemented for realtime applications. Experiments were conducted to verify the theoretical findings. Good agreement was obtained between the theoretical and experimental results. Multiple thicknesses of two different dielectric samples were estimated in this way

    A Novel Numerical Technique for Dielectric Measurement of Generally Lossy Dielectrics

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    A method for determining the dielectric properties of infinite half-space of generally lossy dielectric materials is described. This method utilizes the measurement of the admittance of a rectangular waveguide radiating into such dielectrics. It is shown that the real part of the admittance is relatively insensitive to the variations of the imaginary part of the dielectric constant. Subsequently, a numerical procedure is initiated which provides a simple and fast-converging approach for calculating the dielectric properties. This numerical procedure lends itself to implementation by personal computers--a major advantage over the existing computational schemes. The theoretical formulation for the expression of the admittance of an open-ended waveguide and the numerical procedure are discussed in detail. Results of several measurements of freespace and lossy dielectric samples (rubber with carbon black) to verify the theory and the numerical scheme are given. The results give good agreement with other measurement schemes. Comments on the accuracy of the results are also provided

    Analysis of Radiation from an Open-Ended Coaxial Line into Stratified Dielectrics

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    Radiation from an open-ended coaxial transmission line into an N-layer dielectric medium is studied in application to nondestructive evaluation of materials. Explicit formulations for two cases of layered media, one terminated into an infinite half-space and the other into a conducting sheet are addressed in general form. In the theoretical derivations it is assumed that only the fundamental TEM mode propagates inside the coaxial line. The terminating admittance of the line is then formulated using the continuity of the power flow across the aperture. The admittance expressions for specific cases of two-layer dielectric composite with generally lossy dielectric properties, and a two-layer composite backed by a conducting sheet are presented and inspected explicitly. The numerical results of the aperture admittance formulation are discussed and compared with the available infinite half-space model which had been experimentally verified

    Limbitis Secondary to Autologous Serum Eye Drops in a Patient with Atopic Keratoconjunctivitis

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    Purpose. Report a case of limbitis secondary to autologous serum eye drops in a patient with atopic keratoconjunctivitis. Design. Interventional case report. Methods. A 32-year-old African American female with atopic keratoconjunctivitis (AKC) presented with chronic dry eye and diffuse punctate epithelial erosions refractory to conservative treatment. She was initially managed with cyclosporine ophthalmic 0.05% in addition to preservative-free artificial tears and olopatadine hydrochloride 0.2% for 6 months. She was later placed on autologous serum eye drops (ASEDs) and 4 weeks into treatment developed unilateral limbitis. The limbitis resolved shortly after stopping ASEDs in that eye; however, the drops were continued in the contralateral eye, which subsequently developed limbitis within 2 weeks. ASEDs were discontinued in both eyes, and the patient has remained quiet ever since. Results. Patient with a history of AKC and no prior history of limbitis developed limbitis shortly after starting ASEDs, which resolved promptly after discontinuation of therapy with no subsequent recurrence of inflammation. Conclusion. ASEDs are widely used in the treatment of complicated or treatment refractory dry eye. The potential side effects should be kept in mind when prescribing ASEDs for any patient, especially in those with underlying immunological diseases and circulating inflammatory factors

    Estimating flood characteristics using geomorphologic flood index with regards to rainfall intensity-duration-frequency-area curves and CADDIES-2D model in three Iranian basins

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    This is the final version. Available on open access from MDPI via the DOI in this recordThere is not enough data and computational power for conventional flood mapping methods in many parts of the world, thus fast and low-data-demanding methods are very useful in facing the disaster. This paper presents an innovative procedure for estimating flood extent and depth using only DEM SRTM 30 m and the Geomorphic Flood Index (GFI). The Geomorphologic Flood Assessment (GFA) tool which is the corresponding application of the GFI in QGIS is implemented to achieved the results in three basins in Iran. Moreover, the novel concept of Intensity-Duration-Frequency-Area (IDFA) curves is introduced to modify the GFI model by imposing a constraint on the maximum hydrologically contributing area of a basin. The GFA model implements the linear binary classification algorithm to classify a watershed into flooded and non-flooded areas using an optimized GFI threshold that minimizes the errors with a standard flood map of a small region in the study area. The standard hydraulic model envisaged for this study is the Cellular Automata Dual-DraInagE Simulation (CADDIES) 2D model which employs simple transition rules and a weight-based system rather than complex shallow water equations allowing fast flood modelling for large-scale problems. The results revealed that the floodplains generated by the GFI has a good agreement with the standard maps, especially in the fluvial rivers. However, the performance of the GFI decreases in the less steep and alluvial rivers. With some overestimation, the GFI model is also able to capture the general trend of water depth variations in comparison with the CADDIES-2D flood depth map. The modifications made in the GFI model, to confine the maximum precipitable area through implementing the IDFAs, improved the classification of flooded area and estimation of water depth in all study areas. Finally, the calibrated GFI thresholds were used to achieve the complete 100-year floodplain maps of the study areas.University of BasilicataCNR-IMAAOpenet TechnologiesRoyal Academy of Engineering (RAE
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