Determination of the optical characteristics of scattering layers from diffuse reflection and transmission

1980 ◽  
Vol 33 (4) ◽  
pp. 1143-1148
Author(s):  
�. P. Zege ◽  
M. P. Znachenok ◽  
I. L. Katsev
Keyword(s):  
Diffuse Reflection ◽  
Optical Characteristics ◽  
Reflection And Transmission

scholarly journals Investigation of thermometrical optical characteristics influence on spectral thermometry metrological characteristics

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Leonid Zhukov 1 ◽  
D. A. Petrenko 2 ◽  
А. L. Коrnienko 3
Keyword(s):  
Quantitative Determination ◽  
Spectral Ratio ◽  
Spectral Emissivity ◽  
Optical Characteristics ◽  
Reflection And Transmission ◽  
New Methods ◽  
Classical Energy ◽  
Symmetric Wave ◽  
Spectral Coefficients

The complex of investigations of optical characteristics of controlled objects and spectral symmetric-wave and two-colour compensating thermometry (SWT and TCCT) influence on their errors of method and instrumental errors is performed. Advantages of these new methods in the field of errors of method, in comparison with known spectral and also classical energy and spectral ratio thermometry are proved. It is established that right use of the SWT and the TCCT, which takes into account thermometrical conditions, allows to completely exclude methodical and instrumental components from the errors of optical temperature measurements. Spectral thermometry is based on remote quantitative determination of the spectral emissivity distributions of controlled objects. Using these distributions and well-known relationships between the spectral coefficients of emission, absorption, reflection and transmission we can determine macro-optical characteristics of these objects and remotely investigate them.

scholarly journals WAVE TRANSMISSION THROUGH TRAPEZOIDAL BREAKWATERS

1978 ◽  
Vol 1 (16) ◽  
pp. 129 ◽  
Author(s):  
Ole Secher Madsen ◽  
Paisal Shusang ◽  
Sue Ann Hanson
Keyword(s):  
Energy Dissipation ◽  
Approximate Method ◽  
Cross Section ◽  
Wave Energy ◽  
Graphical Form ◽  
Dissipated Energy ◽  
Simple Method ◽  
Reflection And Transmission ◽  
Transmission Coefficients

In a previous paper Madsen and White (1977) developed an approximate method for the determination of reflection and transmission characteristics of multi-layered, porous rubble-mound breakwaters of trapezoidal cross-section. This approximate method was based on the assumption that the energy dissipation associated with the wave-structure interaction could be considered as two separate mechanisms: (1) an external, frictional dissipation on the seaward slope; (2) an internal dissipation within the porous structure. The external dissipation on the seaward slope was evaluated from the semi-theoretical analysis of energy dissipation on rough, impermeable slopes developed by Madsen and White (1975). The remaining wave energy was represented by an equivalent wave incident on a hydraulically equivalent porous breakwater of rectangular cross-section. The partitioning of the remaining wave energy among reflected, transmitted and internally dissipated energy was evaluated as described by Madsen (1974), leading to a determination of the reflection and transmission coefficients of the structure. The advantage of this previous approximate method was its ease of use. Input data requirements were limited to quantities which would either be known (water depth, wave characteristics, breakwater geometry, and stone sizes) or could be estimated (porosity) by the design engineer. This feature was achieved by the employment of empirical relationships for the parameterization of the external and internal energy dissipation mechanisms. General solutions were presented in graphical form so that calculations could proceed using no more sophisticated equipment than a hand calculator (or a slide rule). This simple method gave estimates of transmission coefficients in excellent agreement with laboratory measurements whereas its ability to predict reflection coefficients left a lot to be desired.

Determination of optical bandgap energy and optical characteristics of Cd30Se50S20 thin film at various thicknesses

2022 ◽  
Vol 148 ◽  
pp. 107770
Author(s):  
Ammar Qasem ◽  
Mohamed S. Mostafa ◽  
H.A. Yakout ◽  
Mona Mahmoud ◽  
E.R. Shaaban
Keyword(s):  
Thin Film ◽  
Optical Bandgap ◽  
Optical Characteristics ◽  
Bandgap Energy ◽  
Optical Bandgap Energy

Denitrification of water using ZnO/Cu as the photocatalyst

2018 ◽  
Vol 7 (3) ◽  
pp. 255-259 ◽  
Author(s):  
Ehasn Rahmani ◽  
Mohammad Rahmani
Keyword(s):  
Diffuse Reflection ◽  
Nano Particles ◽  
Diffuse Reflection Spectroscopy ◽  
Reflection Spectroscopy ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
Wet Impregnation ◽  
X Ray ◽  
Nanoparticle Morphology

Abstract The ZnO:xCu photocatalyst was prepared with reacting media, namely, water method followed by wet impregnation to deposit Cu on the ZnO nano particles. X-ray diffraction was used to perform crystallography and the determination of the ZnO:xCu particle size. Fourier transform infrared was employed for the detection of chemical bonds in the synthesized photocatalyst. The nanoparticle morphology was studied by field emission scanning electron microscope. The elemental composition of the synthesized catalysts was evaluated with X-ray fluorescence technique. Diffuse reflection spectroscopy analysis was performed to investigate the light absorption of the ZnO:xCu catalysts. The photocatalytic activity of the prepared ZnO:xCu nanoparticles was studied for the removal of nitrate from the aqueous solution of ammonium nitrate (50 mg·l−1) under UV irradiation. Results indicated that the ZnO:xCu photocatalyst has high photocalytic activity to remove nitrate from water. Moreover, complete degradation was achieved after 2.5 h.

Thin-Film Optical Constants Determined from Infrared Reflectance and Transmittance Measurements

1989 ◽  
Vol 43 (6) ◽  
pp. 1027-1032 ◽  
Author(s):  
Thierry Buffeteau ◽  
Bernard Desbat
Keyword(s):  
Thin Films ◽  
Optical Constants ◽  
Grazing Incidence ◽  
Infrared Region ◽  
Matrix Formalism ◽  
Experimental Conditions ◽  
Reflection And Transmission ◽  
Transmission Coefficients ◽  
Multilayered Systems

A general method based upon reflectance and transmittance measurements in the infrared region has been developed for the determination of the optical constants n( v) and k( v) of thin films deposited on any substrate (transparent or not). The corresponding computer program, written in FORTRAN 77, involves three main parts: (1) a matrix formalism to compute reflection and transmission coefficients of multilayered systems; (2) an iterative Newton-Raphson method to estimate the optical constants by comparison of the calculated and experimental values; and (3) a fast Kramers-Krönig transform to improve the accuracy of calculating the refractive index. The first part of this program can be used independently to simulate reflection and transmission spectra of any multilayered system using various experimental conditions. Two practical examples are given for illustration. Simulation of reflection spectra at grazing incidence for thin films deposited on a metal surface and determination of the optical constants for thin CaF2 layers deposited on a silicon substrate are presented.

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