Density Change of an Oxidized Nuclear Graphite by Acoustic Microscopy and Image Processing

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Se-Hwan Chi ◽  
Cristian I. Contescu ◽  
Timothy D. Burchell
Keyword(s):  
Image Processing ◽  
Density Measurement ◽  
Physical And Mechanical Properties ◽  
Nondestructive Method ◽  
Acoustic Microscopy ◽  
Present Observation ◽  
Graphite Sample ◽  
Nondestructive Technique ◽  
Nuclear Graphite ◽  
Comparison Of The Results

The strong correlation between the density and the physical and mechanical properties of graphite suggests that the method of nondestructive density evaluation could be developed into a characterization technique of great value for the overall improvement of the safety of graphite moderator reactors. In this study, the oxidation-induced density changes in nuclear graphite for very high temperature reactor were determined by a conventional destructive bulk density measurement method (BM) and by a new nondestructive method based on acoustic microscopy and image processing (AM). The results were compared in order to validate the applicability of the latter method. For a direct comparison of the results from both measurements, two specimens were prepared from a cylindrical graphite sample (1 in. diameter and 1 in. height, oxidized to 10% weight loss at 973 K in air for 5 h). The specimens were used for characterization by BM and AM methods, respectively. The results show that, even with a large standard deviation of the AM, the density changing trend from both methods appeared the same. The present observation may be attributed to the fact that AM images reflect characteristic density changes of the graphite sample through the acoustic impedance changes. This study demonstrates the possibility of using AM as a nondestructive technique for the evaluation of density changes in graphite when a database is prepared through a systematic series of experiments.

Density Change of an Oxidized Nuclear Graphite by Acoustic Microscopy and Image Processing

2008 ◽  
Author(s):  
Se-Hwan Chi ◽  
Cristian I. Contescu ◽  
Timothy D. Burchell
Keyword(s):  
Image Processing ◽  
Density Measurement ◽  
Physical And Mechanical Properties ◽  
Acoustic Microscopy ◽  
Graphite Sample ◽  
Nondestructive Technique ◽  
Nuclear Graphite ◽  
Changing Trend ◽  
Density Evaluation ◽  
Comparison Of The Results

The strong correlation between the density and the physical and, mechanical properties of graphite suggests that the method of nondestructive density evaluation could be developed into a characterization technique of great value for the overall improvement of safety of graphite moderator reactors. In this study, the oxidation-induced density changes in nuclear graphite for VHTR were determined by a conventional destructive bulk density measurement method (BM), and by a new non-destructive method based on acoustic microscopy and image processing (AM). The results were compared in order to validate the applicability of the latter method. For a direct comparison of the results from both measurements, two specimens were prepared from a cylindrical graphite sample (1 inch diameter and 1 inch height, oxidized to 10% weight loss at 973 K in air for 5 hours). The specimens were used for characterization by BM and AM methods, respectively. The results show that, even with a large standard deviation of the AM, the density changing trend from both methods appeared the same. This observation may be attributed to the fact that AM images reflect characteristic density changes of the graphite sample through the acoustic impedance changes. This study demonstrates the possibility of using AM as a nondestructive technique for the evaluation of density changes in graphite when a database is prepared through a systematic series of experiments.

Extending Acoustic Microscopy for Comprehensive Failure Analysis Applications

2010 ◽  
Author(s):  
Sebastian Brand ◽  
Matthias Petzold ◽  
Peter Czurratis ◽  
Peter Hoffrogge
Keyword(s):  
Image Processing ◽  
Failure Analysis ◽  
Signal Analysis ◽  
Flip Chip ◽  
Fault Isolation ◽  
Acoustic Microscopy ◽  
Specific Information ◽  
Full Potential ◽  
Time Frequency ◽  
Non Destructive

Abstract In industrial manufacturing of microelectronic components, non-destructive failure analysis methods are required for either quality control or for providing a rapid fault isolation and defect localization prior to detailed investigations requiring target preparation. Scanning acoustic microscopy (SAM) is a powerful tool enabling the inspection of internal structures in optically opaque materials non-destructively. In addition, depth specific information can be employed for two- and three-dimensional internal imaging without the need of time consuming tomographic scan procedures. The resolution achievable by acoustic microscopy is depending on parameters of both the test equipment and the sample under investigation. However, if applying acoustic microscopy for pure intensity imaging most of its potential remains unused. The aim of the current work was the development of a comprehensive analysis toolbox for extending the application of SAM by employing its full potential. Thus, typical case examples representing different fields of application were considered ranging from high density interconnect flip-chip devices over wafer-bonded components to solder tape connectors of a photovoltaic (PV) solar panel. The progress achieved during this work can be split into three categories: Signal Analysis and Parametric Imaging (SA-PI), Signal Analysis and Defect Evaluation (SA-DE) and Image Processing and Resolution Enhancement (IP-RE). Data acquisition was performed using a commercially available scanning acoustic microscope equipped with several ultrasonic transducers covering the frequency range from 15 MHz to 175 MHz. The acoustic data recorded were subjected to sophisticated algorithms operating in time-, frequency- and spatial domain for performing signal- and image analysis. In all three of the presented applications acoustic microscopy combined with signal- and image processing algorithms proved to be a powerful tool for non-destructive inspection.

Backside Application of Acoustic Micro Imaging (AMI) on Plastic Ball Grid Array (PBGA) and Plastic Quad Flat Pack (PQFP) Packages

2004 ◽  
Author(s):  
Luis A. Curiel ◽  
Andrew J. Komrowski ◽  
Daniel J.D. Sullivan
Keyword(s):  
Ball Grid Array ◽  
Acoustic Microscopy ◽  
Electronic Packages ◽  
Nondestructive Technique ◽  
Molding Compound ◽  
Microscopy Technique ◽  
Plastic Ball ◽  
Die Surface ◽  
Plastic Ball Grid Array ◽  
Bond Pads

Abstract Acoustic Micro Imaging (AMI) is an established nondestructive technique for evaluation of electronic packages. Non-destructive evaluation of electronic packages is often a critical first step in the Failure Analysis (FA) process of semiconductor devices [1]. The molding compound to die surface interface of the Plastic Ball Grid Array (PBGA) and Plastic Quad Flat Pack (PQFP) packages is an important interface to acquire for the FA process. Occasionally, with these packages, the standard acoustic microscopy technique fails to identify defects at the molding compound to die surface interface. The hard to identify defects are found at the edge of the die next to the bond pads or under the bonds wires. This paper will present a technique, Backside Acoustic Micro Imaging (BAMI) analysis, which can better resolve the molding compound to die surface interface at the die edge by sending the acoustic signal through the backside of the PBGA and PQFP packages.

A NONDESTRUCTIVE TECHNIQUE FOR MEASURING SEEDLING VIGOR IN WHEAT

1977 ◽  
Vol 57 (3) ◽  
pp. 983-985 ◽  
Author(s):  
L. E. EVANS ◽  
G. M. BHATT
Keyword(s):  
Nondestructive Method ◽  
Seedling Vigor ◽  
Nondestructive Technique ◽  
Breeding Programs ◽  
Shoot Weight ◽  
Subsequent Regeneration ◽  
Green Shoot

A nondestructive method of screening for seedling vigor is described. The technique involves the measurement of green shoot weight and the subsequent regeneration of the plants from transplanted shoots or from the seedling base. The method is quick and can be adapted to breeding programs.

scholarly journals Atomic force acoustic microscopy reveals the influence of substrate stiffness and topography on cell behavior

2019 ◽  
Vol 10 ◽  
pp. 2329-2337 ◽  
Author(s):  
Yan Liu ◽  
Li Li ◽  
Xing Chen ◽  
Ying Wang ◽  
Meng-Nan Liu ◽  
...  
Keyword(s):  
Acoustic Microscopy ◽  
Substrate Stiffness ◽  
Cell Behavior ◽  
Cell Alignment ◽  
Nondestructive Technique ◽  
Elastic Deformations ◽  
L929 Cells ◽  
Atomic Force ◽  
Cell Substrate ◽  
Influence Of Substrate

The stiffness and the topography of the substrate at the cell–substrate interface are two key properties influencing cell behavior. In this paper, atomic force acoustic microscopy (AFAM) is used to investigate the influence of substrate stiffness and substrate topography on the responses of L929 fibroblasts. This combined nondestructive technique is able to characterize materials at high lateral resolution. To produce substrates of tunable stiffness and topography, we imprint nanostripe patterns on undeveloped and developed SU-8 photoresist films using electron-beam lithography (EBL). Elastic deformations of the substrate surfaces and the cells are revealed by AFAM. Our results show that AFAM is capable of imaging surface elastic deformations. By immunofluorescence experiments, we find that the L929 cells significantly elongate on the patterned stiffness substrate, whereas the elasticity of the pattern has only little effect on the spreading of the L929 cells. The influence of the topography pattern on the cell alignment and morphology is even more pronounced leading to an arrangement of the cells along the nanostripe pattern. Our method is useful for the quantitative characterization of cell–substrate interactions and provides guidance for the tissue regeneration therapy in biomedicine.

Density Measurement of Thin Sputtered Carbon Films

1988 ◽  
Vol 32 ◽  
pp. 323-330 ◽  
Author(s):  
G. L. Gorman ◽  
M.-M. Chen ◽  
G. Castillo ◽  
R. C. C. Perera
Keyword(s):  
Carbon Film ◽  
Processing Condition ◽  
Density Measurement ◽  
Practical Interest ◽  
Processing Parameters ◽  
Carbon Films ◽  
Nondestructive Method ◽  
Gas Pressure ◽  
X Ray ◽  
Thin Carbon

AbstractThe densities of sputtered thin carbon films have been determined using a novel X-ray technique. This nondestructive method involves the measurement of the transmitivity of a characteristic soft (low energy) X-ray line through the carbon film, and using the established equation I1 = I0eμpt where I1/I0 is the transmitivity, fi the photo absorption cross section, t the independently measured thickness, the density p can be easily solved for. This paper demonstrates the feasibility of using this simple technique to measure densities of carbon films as thin as 300 Å, which is of tremendous practical interest as carbon films on this order of thickness are used extensively as abrasive and corrosive barriers (overcoats) for metallic recording media disks. The dependence of the density upon film thickness for a fixed processing condition is presented, as also its dependence (for a fixed thickness) upon different processing parameters (e.g., sputtering gas pressure and target power). The trends noted in this study indicate that the sputtering gas pressure plays the most important role, changing the film density from 2.4gm/cm3 at 1 mTorr to 1.5gm/cm3 at 30 mTorr for 1000 Å thick films.

scholarly journals Buckling of a Pressurized Hemispherical Shell Subjected to a Probing Force

2017 ◽  
Vol 84 (12) ◽  
Author(s):  
Joel Marthelot ◽  
Francisco López Jiménez ◽  
Anna Lee ◽  
John W. Hutchinson ◽  
Pedro M. Reis
Keyword(s):  
Mechanical Response ◽  
Nondestructive Method ◽  
Pressure Loading ◽  
Spherical Shells ◽  
Nondestructive Technique ◽  
Nonlinear Load ◽  
Elastic Shells ◽  
Geometric Imperfection ◽  
Hemispherical Shell ◽  
The Stability

We study the buckling of hemispherical elastic shells subjected to the combined effect of pressure loading and a probing force. We perform an experimental investigation using thin shells of nearly uniform thickness that are fabricated with a well-controlled geometric imperfection. By systematically varying the indentation displacement and the geometry of the probe, we study the effect that the probe-induced deflections have on the buckling strength of our spherical shells. The experimental results are then compared to finite element simulations, as well as to recent theoretical predictions from the literature. Inspired by a nondestructive technique that was recently proposed to evaluate the stability of elastic shells, we characterize the nonlinear load-deflection mechanical response of the probe for different values of the pressure loading. We demonstrate that this nondestructive method is a successful local way to assess the stability of spherical shells.

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