Spectral Sensing of Asbestos According to Concentration in Various Asbestos Containing Materials

2014 ◽  
Vol 627 ◽  
pp. 7-11 ◽  
Author(s):  
Ho Sang Ahn ◽  
Byung Kwon Jung ◽  
Jin Chul Joo ◽  
Jae Ro Park
Keyword(s):  
Refractive Index ◽  
Optimum Condition ◽  
Wavelength Range ◽  
Building Materials ◽  
Asbestos Fiber ◽  
Color Filter ◽  
Particulate Matters ◽  
Blue Color ◽  
Experimental Conditions ◽  
Spectral Sensing

Asbestos in various building materials were measured by spectral sensor to examine the shift in reflectance wavelength according to asbestos concentration in different materials. Asbestos glove, asbestos soil, asbestos fiber insulation board, slate and bamlite panel were tested under several experimental conditions to alter reflectance intensity at each wavelength to find the optimum condition to detect asbestos selectively from other particulate matters. Chrysotile was found to have specific wavelength range regardless of concentration and type of materials as detected under blue color filter and dyed with refractive index liquid.

scholarly journals Scattering and Absorption Cross-sections of Atmospheric Gases in the Ultraviolet-Visible Wavelength Range (307–725 nm)

2020 ◽  
Author(s):  
Quanfu He ◽  
Zheng Fang ◽  
Ofir Shoshamin ◽  
Steven S. Brown ◽  
Yinon Rudich
Keyword(s):  
Refractive Index ◽  
Wavelength Range ◽  
Cross Sections ◽  
Rayleigh Scattering ◽  
Dispersion Relations ◽  
Optical Absorption Spectroscopy ◽  
Absorption Cross ◽  
Atmospheric Gases ◽  
Scattering Cross ◽  
Scattering Cross Sections

Abstract. Accurate Rayleigh scattering and absorption cross-sections of atmospheric gases are essential for understanding the propagation of electromagnetic radiation in planetary atmospheres. Accurate extinction cross-sections are also essential for calibrating high finesse optical cavities and differential optical absorption spectroscopy and for accurate remote sensing. In this study, we measured the scattering and absorption cross-sections of carbon dioxide, nitrous oxide, sulfur hexafluoride, oxygen, and methane in the continuous wavelength range of 307–725 nm using Broadband Cavity Enhanced Spectroscopy (BBCES). The experimentally derived Rayleigh scattering cross-sections for CO2, N2O, SF6, O2, and CH4 agree with refractive index-based calculations, with a difference of 1.5 % and 1.1 %, 1.5 %, 2.9 %, and 1.4 % on average, respectively. The O2-O2 collision-induced absorption and absorption by methane are obtained with high precision at the 0.8 nm resolution of our BBCES instrument in the 307–725 nm wavelength range. New dispersion relations for N2O, SF6, and CH4 were derived using data in the UV-vis wavelength range. This study provides improved refractive index dispersion relations, n-based Rayleigh scattering cross-sections, and absorption cross-sections for these gases.

scholarly journals Determination of the refractive index of insoluble organic extracts from atmospheric aerosol over the visible wavelength range using optical tweezers

2017 ◽  
Author(s):  
Rosalie H. Shepherd ◽  
Martin D. King ◽  
Amelia Marks ◽  
Neil Brough ◽  
Andrew D. Ward
Keyword(s):  
Refractive Index ◽  
Wavelength Range ◽  
Atmospheric Aerosol ◽  
Organic Aerosol ◽  
Wood Smoke ◽  
Angstrom Exponent ◽  
Organic Extracts ◽  
Ångström Exponent ◽  
Aqueous Core ◽  
Real Refractive Index

Abstract. Optical trapping combined with Mie spectroscopy is a new technique used to record the refractive index of insoluble organic material extracted from atmospheric aerosol samples over a wide wavelength range with sub-nanometer resolution. The refractive index of the insoluble organic extracts was shown to follow a Cauchy equation between 460 to 700 nm for organic aerosol extracts collected from urban (London) and remote (Antarctica) locations. Cauchy coefficients for the remote sample were for the Austral summer and gave the Cauchy coefficients to be A = 1.467 and B = 1000 nm2 with a real refractive index of 1.489 at a wavelength of 589 nm. Cauchy coefficients for the urban samples varied with season, with extracts collected during summer having Cauchy coefficients of A = 1.465±0.005 and B = 4625±1200 nm2 with a representative real refractive index of 1.478 at a wavelength of 589 nm, whilst samples extracted during autumn had larger Cauchy coefficients of A=1.505 and B = 600 nm2 with a representative real refractive index of 1.522 at a wavelength of 589 nm. The refractive index of absorbing aerosol was also recorded. The technique applied in the presented study allowed the absorption Ångstrom exponent to be determined for wood smoke and humic acid aerosol extract. Typical values of the Cauchy coefficient for the wood smoke aerosol extract were A = 1.541±0.03 and B = 14800±2900 nm2 resulting in a real refractive index of 1.584±0.007 at a wavelength of 589 nm and an absorption Ångstrom exponent of 7.0. The measured values of refractive index compare well with previous monochromatic or very small wavelength range measurements of refractive index. A one-dimensional radiative-transfer calculation of the top of the atmosphere albedo was applied to model an atmosphere containing a 3 km thick layer of aerosol comprising of pure water, insoluble organic aerosol or an aerosol consisting of an aqueous core-with an insoluble organic shell. The calculation demonstrated that the top of the atmosphere albedo increases by 0.01 to 0.04 for pure organic particles relative to water particles of the same size and the top of the atmosphere albedo increases by 0.03 for aqueous core-shell particles as volume fraction of the shell material increases by 25 percent.

scholarly journals Determination of the refractive index of insoluble organic extracts from atmospheric aerosol over the visible wavelength range using optical tweezers

2018 ◽  
Vol 18 (8) ◽  
pp. 5235-5252 ◽  
Author(s):  
Rosalie H. Shepherd ◽  
Martin D. King ◽  
Amelia A. Marks ◽  
Neil Brough ◽  
Andrew D. Ward
Keyword(s):  
Refractive Index ◽  
Wavelength Range ◽  
Atmospheric Aerosol ◽  
Organic Aerosol ◽  
Angstrom Exponent ◽  
Organic Extracts ◽  
Ångström Exponent ◽  
Aqueous Core ◽  
Ångstrom Exponent ◽  
Real Refractive Index

Abstract. Optical trapping combined with Mie spectroscopy is a new technique used to record the refractive index of insoluble organic material extracted from atmospheric aerosol samples over a wide wavelength range. The refractive index of the insoluble organic extracts was shown to follow a Cauchy equation between 460 and 700 nm for organic aerosol extracts collected from urban (London) and remote (Antarctica) locations. Cauchy coefficients for the remote sample were for the Austral summer and gave the Cauchy coefficients of A = 1.467 and B = 1000 nm2 with a real refractive index of 1.489 at a wavelength of 589 nm. Cauchy coefficients for the urban samples varied with season, with extracts collected during summer having Cauchy coefficients of A=1.465±0.005 and B=4625±1200 nm2 with a representative real refractive index of 1.478 at a wavelength of 589 nm, whilst samples extracted during autumn had larger Cauchy coefficients of A = 1.505 and B = 600 nm2 with a representative real refractive index of 1.522 at a wavelength of 589 nm. The refractive index of absorbing aerosol was also recorded. The absorption Ångström exponent was determined for woodsmoke and humic acid aerosol extract. Typical values of the Cauchy coefficient for the woodsmoke aerosol extract were A=1.541±0.03 and B=14800±2900 nm2, resulting in a real refractive index of 1.584 ± 0.007 at a wavelength of 589 nm and an absorption Ångström exponent of 8.0. The measured values of refractive index compare well with previous monochromatic or very small wavelength range measurements of refractive index. In general, the real component of the refractive index increases from remote to urban to woodsmoke. A one-dimensional radiative-transfer calculation of the top-of-the-atmosphere albedo was applied to model an atmosphere containing a 3 km thick layer of aerosol comprising pure water, pure insoluble organic aerosol, or an aerosol consisting of an aqueous core with an insoluble organic shell. The calculation demonstrated that the top-of-the-atmosphere albedo increases by 0.01 to 0.04 for pure organic particles relative to water particles of the same size and that the top-of-the-atmosphere albedo increases by 0.03 for aqueous core-shell particles as volume fraction of the shell material increases to 25 %.

scholarly journals Hydrometallurgical Recycling of Copper Anode Furnace Dust for a Complete Recovery of Metal Values

Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 36
Author(s):  
Dušan Oráč ◽  
Jakub Klimko ◽  
Dušan Klein ◽  
Jana Pirošková ◽  
Pavol Liptai ◽  
...  
Keyword(s):  
Optimum Condition ◽  
Complete Recovery ◽  
Zinc Powder ◽  
The Other ◽  
Copper Production ◽  
Copper Anode ◽  
Experimental Conditions ◽  
Ph Adjustment ◽  
H2so4 Concentration ◽  
Solid Ratio

Copper anode furnace dust is waste by-product of secondary copper production containing zinc, lead, copper, tin, iron and many other elements. Hydrometallurgical Copper Anode Furnace dust recycling method was studied theoretically by thermodynamic calculations and the proposed method was verified experimentally on a laboratory scale. The optimum condition for leaching of zinc from dust was identified to be an ambient leaching temperature, a liquid/solid ratio of 10 and H2SO4 concentration of 1 mol/L. A maximum of 98.85% of zinc was leached under the optimum experimental conditions. In the leaching step, 99.7% of lead in the form of insoluble PbSO4 was separated from the other leached metals. Solution refining was done by combination of pH adjustment and zinc powder cementation. Tin was precipitated from solution by pH adjustment to 3. Iron was precipitated out of solution after pH adjustment to 4 with efficiency 98.54%. Copper was selectively cemented out of solution (99.96%) by zinc powder. Zinc was precipitated out of solution by addition of Na2CO3 with efficiency of 97.31%. ZnO as final product was obtained by calcination of zinc carbonates.

scholarly journals Passive Measurements of the Refractive Index of Liquid Nitrogen and Free-flowing substances by the Prism Method in the Millimeter Wavelength Range

2021 ◽  
Vol 13 (4) ◽  
pp. 435-443
Author(s):  
Valery A. Golunov ◽  
◽  
Konstantin V. Gordeev ◽  
Konstantin N. Rykov ◽  
◽  
...  
Keyword(s):  
Refractive Index ◽  
Liquid Nitrogen ◽  
Wavelength Range ◽  
Black Body ◽  
Test Substance ◽  
Particle Sizes ◽  
Radiation Mode ◽  
Millimeter Wavelength ◽  
Lens Antennas ◽  
Passive Measurements

It is proposed to use the classical prism method in the millimeter wavelength range for measuring the refractive index of liquid and free-flowing substances, including mixtures with particle sizes comparable to the wavelength. The method is implemented using a hollow radio transparent rectangular prism filled with a test substance. The measurements were carried out in the thermal radiation mode using radiometers with horn-lens antennas at frequencies of 37.5 and 94 GHz. To measure the deflection of the refracted beam, a linear scanner with a black body mounted on it, cooled with liquid nitrogen, was used. The distance between the prism and the scanner was 1 m. The refractive index of liquid nitrogen, sand, gravel, marble chips and granular polyethylene were measured. Using the refractive formula and the Landau-Lifshitz-Looeng formula for calculating the dependence of the refractive index of binary mixtures on the bulk density of particles, estimates of the refractive index of the material of the particles that make up the substances under study are obtained. They are in satisfactory agreement with the known experimental data for quartz, feldspar, granite, and marble.

scholarly journals Spectral Radiative Properties of a Liquid n-Octane Droplet in the Midinfrared Region

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Liang Zhao ◽  
Chaoyu Jing ◽  
Yu Jin ◽  
Jiangping Chen ◽  
Ke Yin ◽  
...  
Keyword(s):  
Refractive Index ◽  
Wavelength Range ◽  
Optical Constants ◽  
Absorption Efficiency ◽  
Efficiency Factor ◽  
Radiative Properties ◽  
Droplet Radius ◽  
Scattering Efficiency ◽  
Scattering Coefficients ◽  
Increasing Temperature

The optical constants of a liquid hydrocarbon such as liquid n-octane are basic material properties that may be used to evaluate their thermal radiation transfer capabilities. In this study, the ellipsometry method was used to measure the optical constants of liquid n-octane in the midinfrared wavelength range of 2.0–16.0 μm at temperatures of 20, 50, and 80°C. Experimental analyses indicate the significant effect of temperature on the refractive index, although it has little effect on the absorption index. With increasing temperature, the refractive index shows a linear decrease, and reduced density leads to weaker absorption intensities. The radiative properties of n-octane droplets, including the absorption and scattering efficiency factors of single droplets with droplet radii r = 10, 20, 50, and 100 μm and the absorption and scattering coefficients in a droplets-air system of droplet volume fractions fv = 2%, 3%, and 4%, were calculated using Mie theory. The numerical results indicate that, with increasing temperature, the absorption efficiency factor slightly decreases, and the variation trend of the scattering efficiency factor is more complicated. With increasing droplet radius, the absorption efficiency factor increases within the studied wavelength range, except for certain absorption peaks, but the scattering efficiency factor tends to decrease. While the absorption is greater, the scattering is weaker for a given droplet radius. With an increasing volume fraction of n-octane droplets, the absorption and scattering coefficients increase linearly within the studied wavelength range.

scholarly journals Polystyrene Microsphere Optical Properties by Kubelka–Munk and Diffusion Approximation with a Single Integrating Sphere System: A Comparative Study

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Ali Shahin ◽  
Wesam Bachir ◽  
Moustafa Sayem El-Daher
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Absorption Coefficient ◽  
Wavelength Range ◽  
Diffusion Approximation ◽  
Analytical Methods ◽  
Diffusion Theory ◽  
Integrating Sphere ◽  
Absorption Property ◽  
Relative Errors

The optical properties of 1 μm polystyrene in the wavelength range of 500–750 nm were estimated by using a white light spectrophotometric transmittance spectroscopy and a single integrating sphere system. To retrieve the optical characteristics, two analytical methods, namely, diffusion approximation and Kubelka–Munk were used, and then their results were compared with Mie theory calculations. The correspondence of the Kubelka–Munk scattering coefficient with Mie was obvious, and relative errors varied between 6.73% and 2.66% whereas errors varied between 6.87% and 3.62% for diffusion theory. Both analytical methods demonstrated the absorption property of polystyrene over the abovementioned wavelength range. Although absorption coefficient turned out to be much lower than scattering, constructing a realistic optical phantom requires taking into account absorption property of polystyrene. Complex refractive index of polystyrene based on these two methods was determined. Inverse Mie algorithm with scattering coefficient was also used to retrieve the real part of refractive index and absorption coefficient for calculating the imaginary part of refractive index. The relative errors of the real part did not exceed 2.6%, and the imaginary part was in consistence with the prior works. Finally, the presented results confirm the validity of diffusion theory with a single integrating sphere system.

Ellipsometric characterization of thin nanocomposite films with tunable refractive index for biochemical sensors

2011 ◽  
Vol 1352 ◽  
Author(s):  
P. Petrik ◽  
H. Egger ◽  
S. Eiden ◽  
E. Agocs ◽  
M. Fried ◽  
...  
Keyword(s):  
Refractive Index ◽  
Wavelength Range ◽  
Spectroscopic Ellipsometry ◽  
High Refractive Index ◽  
Optical Quality ◽  
Nanocomposite Films ◽  
Optical Parameters ◽  
Sensor Applications ◽  
Preparation Conditions

ABSTRACTCreating optical quality thin films with a high refractive index is increasingly important for waveguide sensor applications. In this study, we present optical models to measure the layer thickness, vertical and lateral homogeneity, the refractive index and the extinction coefficients of the polymer films with nanocrystal inclusions using spectroscopic ellipsometry. The optical properties can be determined in a broad wavelength range from 190 to 1700 nm. The sensitivity of spectroscopic ellipsometry allows a detailed characterization of the nanostructure of the layer, i.e. the surface roughness down to the nm scale, the interface properties, the optical density profile within the layer, and any other optical parameters that can be modeled in a proper and consistent way. In case of larger than about 50 nm particles even the particle size can be determined from the onset of depolarization due to light scattering. Besides the refractive index, the extinction coefficient, being a critical parameter for waveguiding layers, was also determined in a broad wavelength range. Using the above information from the ellipsometric models the preparation conditions can be identified. A range of samples were investigated including doctor bladed films using TiO2 nanoparticles.

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