A novel hyperspectral camera and analysis platform for the non-destructive material identification and mapping: An application in paintings by El Greco

<p><strong>Abstract.</strong> Currently, intervention in heritage is a task of social need. Non-destructive techniques are often used to carry out conservation and maintenance tasks. In the present. In this work we study the necessary calibration mode of a hyperspectral camera used in the characterization of the material to be conserved or to intervene. This camera is used to characterize the material according to its reflectance in different wavelengths. The result obtained is expressed as a function of the light condition at the time of the measurement. One of the most important phases of this technique is to normalize the values obtained in each take. This is conditioned by the intensity of light: the bigger it is, the bigger was reflectance value of a material at a given wavelength. This factor is corrected from patterns that are introduced in the scene. These patterns are elements whose reflectance values are known in the bands of the spectrum that the camera used registers. Likewise, they must reflect or absorb the maximum light (black and white reference, respectively) in order to delimit the maximum and minimum reflectance of each scene. These references will allow two scenes taken in different light conditions to be comparable. Therefore, the influence of black and white references on the scene is studied from the use of materials of different nature.</p>

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Near-field microwave non-destructive testing for defect shape and material identification

Nondestructive Testing And Evaluation ◽

10.1080/10589750600784902 ◽

2006 ◽

Vol 21 (2) ◽

pp. 79-93 ◽

Cited By ~ 1

Author(s):

S. M. Ali ◽

N. K. Nikolova ◽

N. T. Sangary

Keyword(s):

Near Field ◽

Non Destructive Testing ◽

Destructive Testing ◽

Material Identification ◽

Non Destructive

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100088488 ◽

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.

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100117017 ◽

1975 ◽

Vol 33 ◽

pp. 678-679 ◽

Cited By ~ 3

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.

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