scholarly journals CHARACTERIZATION OF TRANSVERSE CYLINDRICAL CAVITIES IN WOODEN BLOCKS OF THE SPECIES Cedrela odorata USING NON-DESTRUCTIVE ULTRASOUND TESTS

FLORESTA ◽  
2021 ◽  
Vol 51 (4) ◽  
pp. 848
Author(s):  
Luis Shuseki Yoza Yoza ◽  
Erik Baradit Allende ◽  
Oscar Enrique Tang Cruz ◽  
Jorge Luis Monteiro de Matos ◽  
Márcio Pereira da Rocha ◽  
...  
Keyword(s):  
Cedrela Odorata ◽  
Cylindrical Cavities ◽  
Non Destructive

scholarly journals Terahertz characterization of two-dimensional low-conductive layers enabled by metal gratings

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Prashanth Gopalan ◽  
Yunshan Wang ◽  
Berardi Sensale-Rodriguez
Keyword(s):  
Optical Transmission ◽  
Terahertz Spectroscopy ◽  
Design Guidelines ◽  
Two Dimensional ◽  
Highly Sensitive ◽  
Transmission Measurements ◽  
Metal Gratings ◽  
Low Sensitivity ◽  
Non Destructive

AbstractWhile terahertz spectroscopy can provide valuable information regarding the charge transport properties in semiconductors, its application for the characterization of low-conductive two-dimensional layers, i.e., σs <  < 1 mS, remains elusive. This is primarily due to the low sensitivity of direct transmission measurements to such small sheet conductivity levels. In this work, we discuss harnessing the extraordinary optical transmission through gratings consisting of metallic stripes to characterize such low-conductive two-dimensional layers. We analyze the geometric tradeoffs in these structures and provide physical insights, ultimately leading to general design guidelines for experiments enabling non-contact, non-destructive, highly sensitive characterization of such layers.

scholarly journals Identification of pigments in artworks by inverse tangent derivative of spectrum and a new filtering method

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
F. Fazlali ◽  
S. Gorji Kandi
Keyword(s):  
Reflectance Spectrum ◽  
Practical Method ◽  
Chemical Methods ◽  
Munk Function ◽  
Absorption Of Light ◽  
Spectrophotometric Data ◽  
First Time ◽  
Non Destructive ◽  
Derivatives Of

Abstract Employing an economical and non-destructive method for identifying pigments utilized in artworks is a significant aspect for preserving their antiquity value. One of the non-destructive methods for this purpose is spectrophotometry, which is based on the selected absorption of light. Mathematical descriptive methods such as derivatives of the reflectance spectrum, the Kubelka–Munk function and logarithm have been employed for the characterization of the peak features corresponding to the spectrophotometric data. In the present study, the mentioned mathematical descriptive methods were investigated with the aim to characterize the constituents of an Iranian artwork but were not efficient for the samples. Therefore, inverse tangent derivative equation was developed on spectral data for the first time, providing considerable details in the profile of reflectance curves. In the next part, to have a simpler and more practical method it was suggested to use filters made up of pure pigments. By using these filters and placing them on the samples, imaging was done. Then, images of samples with and without filter were evaluated and pure pigments were distinguished. The mentioned methods were also used to identify pigments in a modern Iranian painting specimen. The results confirmed these methods with reliable answers indicating that physical methods (alongside chemical methods) can also be effective in determining the types of pigments.

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