Use of visible pulsed photoacoustic technique for the non-destructive measurements of absorption coefficients, thermal diffusion and viscosity properties of natural and clay-blended rubber nanocomposites

Pramana ◽  
2021 ◽  
Vol 95 (4) ◽  
Author(s):  
Archana Kumari ◽  
Hanna J Maria ◽  
A K Chaudhary ◽  
S Thomas
Keyword(s):  
Thermal Diffusion ◽  
Photoacoustic Technique ◽  
Absorption Coefficients ◽  
Rubber Nanocomposites ◽  
Non Destructive

scholarly journals A new method to determine open porosity and permeability constants of open-pore sintered glasses by photoacoustic technique

Cerâmica ◽  
2005 ◽  
Vol 51 (319) ◽  
pp. 259-264
Author(s):  
M. T. Yasuda ◽  
W. L. B. Melo
Keyword(s):  
Structural Properties ◽  
Open Porosity ◽  
Porous Ceramic ◽  
Photoacoustic Signal ◽  
Photoacoustic Technique ◽  
Excellent Correlation ◽  
Grain Sizes ◽  
Porosity And Permeability ◽  
Permeability Constants ◽  
Non Destructive

The Photoacoustic (PA) technique was used to investigate the structural properties (e.g. open porosity and permeability) of open-pore sintered glasses. This work demonstrates that the photoacoustic signal of open-pore sintered glasses, which are produced with different grain sizes and several degrees of open porosity, is sensitive to the morphology of the open-pore samples. The results obtained by the PA technique were related to results obtained by the Pressure Decay technique, and an excellent correlation was obtained. This demonstrates that PA technique, which is non-intrusive and non-destructive, is promising for application in analysis of porous ceramic structures, even if the sample is semi-transparent.

Thermal Diffusion Tomography for Quantitative Non-Destructive Characterization of Electronic Packages

2015 ◽  
Author(s):  
Bahar Öner ◽  
Hakan Ertürk
Keyword(s):  
Thermal Diffusion ◽  
Flip Chip ◽  
Heat Dissipation ◽  
Imaging Techniques ◽  
Acoustic Microscopy ◽  
Reconstruction Technique ◽  
Electronic Packages ◽  
Marquardt Algorithm ◽  
Non Destructive

Thermal management problems in electronic packages have been a challenging problem due to increasing number of transistors in chips and reduction in product size. Thermal interface materials (TIM) help heat dissipation by reducing thermal contact resistance between chip and integrated heat spreader (IHS) and TIM quality is critical for effective removal of heat generated from the package. Therefore, identification of defects within TIM is required during package assembly process development. Imaging techniques such as computerized scanning acoustic microscopy (CSAM) and X-ray tomography are used as non-destructive testing techniques to identify TIM defects qualitatively. More recently, it was shown that IR thermography can be used as a qualitative means of identifying defects as well. Thermal diffusion tomography is a powerful alternative to those techniques due to its lower cost and ease of application. In this study, quantitative characterization of defects in TIM is presented using thermal diffusion tomography. The study is conducted considering a high density interconnect flip chip package that includes spreading effect due to different sized IHS and die. Defect size and location are detected analyzing the measured thermal response of electronic package by solving the resulting inverse problem by Levenberg-Marquardt algorithm as an image reconstruction technique.

scholarly journals Non-destructive Characteristics of Ultrasonic Waves in 1018 Low Carbon Steel

2014 ◽  
Vol 24 (3S1) ◽  
pp. 1-6
Author(s):  
Do Trung Kien ◽  
Pham Thi Tuyet Nhung ◽  
Pham Van Thanh
Keyword(s):  
Carbon Steel ◽  
Longitudinal Wave ◽  
Shear Wave ◽  
Low Carbon Steel ◽  
Ultrasonic Waves ◽  
Low Carbon ◽  
Absorption Coefficients ◽  
Ultrasonic Shear ◽  
Non Destructive ◽  
Good Agreement

In this paper, the dependences of the velocities and the absorption coefficients of ultrasonic waves transmitted in 1018 low carbon steel on temperature ranging from 0\(^{\circ}\)C to 50\(^{\circ}\)C were investigated. It was shown that the velocities of the ultrasonic longitudinal wave and ultrasonic shear wave were decreased when the temperature increased. The transportation of the ultrasonic longitudinal wave and ultrasonic shear wave depends on temperature and its coefficient in a temperature range of (0 - 50 \(^{\circ}\)C) was estimated about 0.8 m/s.\(^{\circ}\)C and 0.44~m/s.\(^{\circ}\)C, respectively. These obtained results are in good agreement with the theoretical prediction. Furthermore, the absorption coefficients of the ultrasonic longitudinal wave were also studied.

Luminescence from individual dislocations in II-VI and III-V semiconductors

1991 ◽  
Vol 49 ◽  
pp. 834-835
Author(s):  
J W Steeds
Keyword(s):  
Group Iv ◽  
Luminescence Properties ◽  
Carrier Recombination ◽  
Transmission Electron ◽  
Wide Range ◽  
Basic Physics ◽  
Semiconducting Compounds ◽  
Diamond Group ◽  
Non Destructive ◽  
Technological Significance

There is a wide range of experimental results related to dislocations in diamond, group IV, II-VI, III-V semiconducting compounds, but few of these come from isolated, well-characterized individual dislocations. We are here concerned with only those results obtained in a transmission electron microscope so that the dislocations responsible were individually imaged. The luminescence properties of the dislocations were studied by cathodoluminescence performed at low temperatures (~30K) achieved by liquid helium cooling. Both spectra and monochromatic cathodoluminescence images have been obtained, in some cases as a function of temperature.There are two aspects of this work. One is mainly of technological significance. By understanding the luminescence properties of dislocations in epitaxial structures, future non-destructive evaluation will be enhanced. The second aim is to arrive at a good detailed understanding of the basic physics associated with carrier recombination near dislocations as revealed by local luminescence properties.

Forensic Identifications Aided by Scanning Electron Microscopy of Silicone-Epoxy Microreplicas of Calcified and Cornified Structures

1975 ◽  
Vol 33 ◽  
pp. 678-679 ◽  
Author(s):  
R.F. Sognnaes
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Forensic Science ◽  
George Washington ◽  
Epithelial Surface ◽  
Extended Application ◽  
Tissue Surfaces ◽  
Non Destructive ◽  
Scanning Electron ◽  
Surface Changes

Sufficient experience has been gained during the past five years to suggest an extended application of microreplication and scanning electron microscopy to problems of forensic science. The author's research was originally initiated with a view to develop a non-destructive method for identification of materials that went into objects of art, notably ivory and ivories. This was followed by a very specific application to the identification and duplication of the kinds of materials from animal teeth and tusks which two centuries ago went into the fabrication of the ivory dentures of George Washington. Subsequently it became apparent that a similar method of microreplication and SEM examination offered promise for a whole series of problems pertinent to art, technology and science. Furthermore, what began primarily as an application to solid substances has turned out to be similarly applicable to soft tissue surfaces such as mucous membranes and skin, even in cases of acute, chronic and precancerous epithelial surface changes, and to post-mortem identification of specific structures pertinent to forensic science.

Interfacial properties of GaSb/InAs superlattices

1993 ◽  
Vol 51 ◽  
pp. 826-827
Author(s):  
M. E. Twigg ◽  
B. R. Bennett ◽  
J. R. Waterman ◽  
J. L. Davis ◽  
B. V. Shanabrook ◽  
...  
Keyword(s):  
Gaas Substrate ◽  
Molecular Beam ◽  
Infrared Detector ◽  
Interfacial Properties ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Absorption Coefficients ◽  
X Ray ◽  
Short Period ◽  
High Optical Absorption

Recently, the GaSb/InAs superlattice system has received renewed attention. The interest stems from a model demonstrating that short period Ga1-xInxSb/InAs superlattices will have both a band gap less than 100 meV and high optical absorption coefficients, principal requirements for infrared detector applications. Because this superlattice system contains two species of cations and anions, it is possible to prepare either InSb-like or GaAs-like interfaces. As such, the system presents a unique opportunity to examine interfacial properties.We used molecular beam epitaxy (MBE) to prepare an extensive set of GaSb/InAs superlattices grown on an GaSb buffer, which, in turn had been grown on a (100) GaAs substrate. Through appropriate shutter sequences, the interfaces were directed to assume either an InSb-like or GaAs-like character. These superlattices were then studied with a variety of ex-situ probes such as x-ray diffraction and Raman spectroscopy. These probes confirmed that, indeed, predominantly InSb-like and GaAs-like interfaces had been achieved.

Sign in / Sign up

Export Citation Format

Share Document