scholarly journals 5. Asteroid Infrared Reflectances and Compositional Implications

1977 ◽  
Vol 39 ◽  
pp. 229-241
Author(s):  
D. L. Matson ◽  
T. V. Johnson ◽  
G. J. Veeder
Keyword(s):  
Optical Properties ◽  
Metallic Phase ◽  
The State ◽  
Reflectance Spectra ◽  
Space Weathering ◽  
Infrared Reflectance ◽  
Reflectance Measurements

This paper assesses the state of asteroid infrared reflectance measurements and discusses what they have contributed to our understanding of asteroidal surfaces. The data suggest that space weathering has not significantly affected the optical properties of the asteroids. Thus comparisons of asteroid reflectance spectra with unweathered meteorite and rock data is a valid procedure. The high 1.6 and 2.2 μm reflectances of a number of asteroids strongly suggest the presence of a metallic phase.

Infrared Reflectance Study of the Graphene/Semi-Insulating 6H-SiC(0001) Heterostructure

2018 ◽  
Vol 924 ◽  
pp. 314-317
Author(s):  
Manuel Auge ◽  
Bernd Hähnlein ◽  
Jörg Pezoldt
Keyword(s):  
Thin Film ◽  
Graphene Layer ◽  
Polarized Light ◽  
Optical Response ◽  
Reflectance Spectra ◽  
Infrared Reflectance ◽  
Ir Reflectance ◽  
Reflectance Measurements

The optical response of graphene on 6H-SiC was investigated by means of IR-reflectance measurements. Thereby, the anisotropy of the substrate is considered and its influence was studied by performing measurements with s- and p-polarized light. The anisotropy causes a splitting of the reststrahlen band in p-polarization, but does not affect spectra recorded with s-polarization. In both cases a thin film approximation was used to simulate the reflectance spectra. A model consisting of SiC, graphene and air enables the extraction of the graphene layer count.

scholarly journals Mineral Physicochemistry Underlying Feature-Based Extraction of Mineral Abundance and Composition from Shortwave, Mid and Thermal Infrared Reflectance Spectra

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 347
Author(s):  
Carsten Laukamp ◽  
Andrew Rodger ◽  
Monica LeGras ◽  
Heta Lampinen ◽  
Ian C. Lau ◽  
...  
Keyword(s):  
Mineral Exploration ◽  
Relevant Information ◽  
Ore Deposits ◽  
Reflectance Spectra ◽  
Full Potential ◽  
Infrared Reflectance ◽  
Vibrational Modes ◽  
Diagnostic Features ◽  
Wide Range ◽  
Mineral Assemblages

Reflectance spectroscopy allows cost-effective and rapid mineral characterisation, addressing mineral exploration and mining challenges. Shortwave (SWIR), mid (MIR) and thermal (TIR) infrared reflectance spectra are collected in a wide range of environments and scales, with instrumentation ranging from spaceborne, airborne, field and drill core sensors to IR microscopy. However, interpretation of reflectance spectra is, due to the abundance of potential vibrational modes in mineral assemblages, non-trivial and requires a thorough understanding of the potential factors contributing to the reflectance spectra. In order to close the gap between understanding mineral-diagnostic absorption features and efficient interpretation of reflectance spectra, an up-to-date overview of major vibrational modes of rock-forming minerals in the SWIR, MIR and TIR is provided. A series of scripts are proposed that allow the extraction of the relative intensity or wavelength position of single absorption and other mineral-diagnostic features. Binary discrimination diagrams can assist in rapidly evaluating mineral assemblages, and relative abundance and chemical composition of key vector minerals, in hydrothermal ore deposits. The aim of this contribution is to make geologically relevant information more easily extractable from reflectance spectra, enabling the mineral resources and geoscience communities to realise the full potential of hyperspectral sensing technologies.

scholarly journals Short-range structure, the role of bismuth and property-structure correlations in bismuth borate glasses

2021 ◽  
Author(s):  
Christos P.E. Varsamis ◽  
Nikos Makris ◽  
Christina Valvi ◽  
E. I. Kamitsos
Keyword(s):  
Short Range ◽  
Composition Range ◽  
Reflectance Spectra ◽  
Borate Glasses ◽  
Infrared Reflectance ◽  
Bismuth Borate ◽  
Splat Quenching ◽  
Structure Correlations ◽  
Short Range Structure

Bismuth-containing borate glasses, xBi2O3-(1-x)B2O3, were synthesized in the broad composition range 0.20≤x≤0.80 by melting in Pt crucibles and splat-quenching between two metal blocks. Infrared reflectance spectra, measured in the range...

Optical Properties of (Pb,Eu)Te Thin Films and Superlattices

1986 ◽  
Vol 89 ◽  
Author(s):  
W. C. Goltsos ◽  
A. V. Nurmikko ◽  
D. L. Partin
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spin Exchange ◽  
Optical Measurements ◽  
Optical Gap ◽  
Exchange Processes ◽  
Reflectance Measurements

AbstractPhotoluminescence, transmission, and reflectance measurements have yielded information about the states defining an optical gap in thin films and superlattices based on the (Pb,Eu)Te system, including the limit of high Eu concentration. Magneto-optical measurements show the presence of finite spin exchange processes at low Eu-concentrations.

Effects of Particle Size on the Near-Infrared Reflectance Spectra of Wheat and Rape Seed Meal Mixtures

1995 ◽  
Vol 49 (1) ◽  
pp. 84-91 ◽  
Author(s):  
Marie-Françoise Devaux ◽  
Nathalie Nathier-Dufour ◽  
Paul Robert ◽  
Dominique Bertrand
Keyword(s):  
Particle Size ◽  
Near Infrared ◽  
Reflectance Spectra ◽  
Seed Meal ◽  
Infrared Reflectance ◽  
Rape Seed ◽  
Near Infrared Reflectance
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