scholarly journals Spectral stratigraphy and clay minerals analysis in parts of Hellas Planitia, Mars

2014 ◽  
Vol XL-8 ◽  
pp. 419-422
Author(s):  
I. C. Das ◽  
J. Joseph ◽  
S. K. Subramanian ◽  
V. K. Dadhwal
Keyword(s):  
Chemical Composition ◽  
Clay Minerals ◽  
Absorption Feature ◽  
Crater Wall ◽  
Spectral Variability ◽  
Origin And Evolution ◽  
Different Types ◽  
Surface Alteration ◽  
Alteration Minerals ◽  
Absorption Features

Absorption features that occur in reflectance spectra are a sensitive indicator of mineralogy and chemical composition for a wide variety of materials. The investigation of the mineralogy and chemical composition of surfaces give information about the origin and evolution of planetary bodies. On Mars, the processes of formation of different types of clay minerals result from different types of wet conditions viz. hydrothermalism, subsurface/groundwater weathering, surface alteration etc. The image analyzed in the present study was frt000947f- 164-trr3 (−27.87N–65.06E). Through the spectral stratigraphic characterization along a crater wall, eight (8) different layers were identified considering the spectral variability and their position. In Hellas Planitia, the alteration minerals identified by CRISM based on distinctive absorptions from 0.4 to3.9 μm include Al-rich smectite, montmorillonite, phyllosilicate mineral at 2.2 μm and 2.35 μm, including strong absorption feature noticed at 1.9 μm. We conclude that the layers exposed in the crater wall help characterize the compositional stratigraphy for confirming the presence of hydrated minerals in this region as an outcome of geohydrological weathering process.

scholarly journals APPLICATION OF WORLDVIEW-3 DATA IN ALTERATION MINERAL MAPPING IN CHADORMALU AREA, CENTRAL IRAN

2019 ◽  
Vol XLII-4/W18 ◽  
pp. 589-596
Author(s):  
Z. Karimzadeh ◽  
M. H. Tangestani
Keyword(s):  
Large Scale ◽  
Iron Ore ◽  
Central Iran ◽  
Iron Deposit ◽  
Absorption Feature ◽  
Spectral Absorption ◽  
Band Ratio ◽  
Band Ratios ◽  
Alteration Minerals ◽  
Absorption Features

Abstract. WorldView-3 (WV-3), launched in August 2014, is a commercial imaging satellite with high spatial resolution that measures reflected radiation in VNIR-SWIR regions in 16 bands. The main objective of this study was to discriminate the alteration minerals in Chadormalu iron deposit area, central Iran, using band ratio techniques on the selected bands of this satellite. To identify the appropriate band ratios the spectral bands of WV-3 were investigated and assessed. Regarding to Fe3+, Fe2+, Al-OH, Fe-OH, Mg-OH and CO32− spectral absorption features, band ratios B5/B2, B13/B9, B13/B14 and B14/B16 were proposed for enhancement of ferrous and ferric iron bearing minerals, sericite, epidote, chlorite, and dolomite. Combination of field observations, geological map and high resolution spectra of rock samples were used to verify the results. Band ratio B5/B2, B13/B9, B13/B14 gray scale images respectively illustrated that Fe3+-rich minerals are occurring in granite, the Fe2+-rich minerals are enhanced in iron ore, green schist, and diorite units, and sericite is occurring in hydrothermally altered granite and iron ore. Since the Fe/Mg-OH vibrational mode in chlorite-epidote and spectral absorption feature of CO32− in dolomite occur in B16, the B14/B16 ratio highlighted chlorite-epidote-rich green schist, diorite and dolomitic marble. The false color composite image of B13/B14, B13/B9, and B14/B16 as RGB produced a large scale map which successfully discriminated the rock types and accompanying alteration minerals. This study demonstrated that WV-3 data have efficient spectral resolution to discriminate alteration minerals with Fe3+, Fe2+, Al-OH and Fe/Mg-OH or CO32− spectral absorption features.

scholarly journals Caracterización de minerales de arcilla y óxidos de hierro mediante espectroscopía de reflectancia difusa (VNIR–SWIR)

2020 ◽  
pp. 49
Author(s):  
A. Báscones ◽  
M. Suárez ◽  
M. Ferrer-Julià ◽  
E. García-Meléndez ◽  
E. Colmenero-Hidalgo ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Spectral Response ◽  
Absorption Feature ◽  
Geometrical Parameters ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
Mineral Phases ◽  
Soils And Sediments ◽  
Absorption Features ◽  
Linear Correlations

<p>The mineralogical analysis was carried out through the spectral properties developed by samples of soils and sediments from the northwestern edge of the Duero Basin. The absorptions produced by the oxides and Feoxyhydroxides (mainly hematite and goethite) are located in VNIR zones (400-1200 nm), while the absorption bands that are present in the SWIR spectra (1200-2500 nm) are related to the chemical composition of clay minerals. The reflectance spectra measured in the laboratory have been normalized by using the methods of Continuum Removal (CR) and the second derivative (SD). This last method can solve the band overlapping because it quantifies subtle drops in the curve. This has allowed the absorption bands to be examined separately by measurement of their geometrical parameters. The proportion of the minerals affects the spectral response and, accordingly, the values of the parameters. Linear correlations were conducted between these values and the proportion of the different mineral phases obtained by X-ray diffraction. In the studied parameters, the correlation between the band center (BC) position in the maximum absorption around the wavelengths at 890-960 nm and the absorption feature depth at 470 nm (D470) has enabled a relative estimation of the proportion of hematite/goethite. As for the distribution of the different clay minerals, a correlation has been established between the proportion of kaolinite and the absorption bands depth at 1415 and 2210 nm, and in the absorption features near 1390 and 2160 nm, analyzed in SD.<em></em></p>

The Chemical Decontamination Process Intensification, using Ultrasounds

2008 ◽  
Vol 59 (9) ◽  
Author(s):  
Eugenia Pantru ◽  
Gheorghit Jinescu ◽  
Rozalia R�dulescu ◽  
Antoneta Filcenco Olteanu ◽  
Cosmin Jinescu
Keyword(s):  
Chemical Composition ◽  
Process Intensification ◽  
Sulphuric Acid Solution ◽  
Liquid Ratio ◽  
Polluted Soils ◽  
Chemical Decontamination ◽  
First Case ◽  
Ultrasound Field ◽  
Different Types ◽  
Main Factors

This paper presents an intensive procedure used for the decontamination of the soils, which were radioactively contaminated by uranium, due to the occurrence of some antropic accidents, in order to limit the area�s pollution. The procedure used for the chemical decontamination of the polluted soils was the washing one and the decontamination degree is comparatively presented depending on the ultrasounds� presence and absence. The lab testes were performed on five types of soils , which were characterized from the granulometric, structural and chemical composition viewpoint, all these aspects represent the main factors, which determine the applied decontamination procedure�s limits and performances correlated with its utilization costs. The decontamination procedure�s kinetics for each type of soils was analyzed, using successively three different types of reagents (water, 0.1 M sulphuric acid solution and chloro-sodic solution � 100 g/L sodium chloride + 10 g/L sodium carbonate in water) for a solid to liquid ratio of 1:2, during 2 h, at a temperature of 20oC in a mechanic stirring system respectively in ultrasounds field. It was observed that the decontamination degree increases with up to 15-20% in case of the ultrasound field utilization comparing to the first case.

scholarly journals PESTRÉ SEDIMENTY OTTNANGU V BRNĚ-KOHOUTOVICÍCH

2018 ◽  
Vol 25 (1-2) ◽  
Author(s):  
Pavla Tomanová Petrová ◽  
David Buriánek ◽  
Karel Kirchner ◽  
Oldřich Krejčí ◽  
František Laufek ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Clay Minerals ◽  
Heavy Fraction ◽  
Parent Rock ◽  
Fine Grained ◽  
Sediment Layers

The reddish coloured sediment layers (up to 5 m thick) were found within building pit in the Brno-Kohoutovice on the Libušina třída Avenue (NW part of Brno). These sediments were assigned to the Ottnangian based on characteristic pseudoassociation of microfossils. Smectite or illite/smectite dominates over kaolinite among the clay minerals. Minerals typomorphic for granitoids of the Brno Massif, i.e. epidote, amphibole and altered titanite, absolutely dominate (99 mod. %) within the assemblage of translucent heavy fraction. Minerals like garnet and staurolite which are typical for the Ottnangian sediments in this region, are presented only in accessoric amount. The chemical composition of the studied sediments is located between the chemical composition of granodiorites of the Brno Massif and Neogene clays. Relatively high content of Zr, Hf and HREE, which is interpreted as result of presence of very fine grained zircon in studied sediments, is characteristic. High content of SiO2 and comparatively low contents of Al2O3 and Fe2O3 indicates non-lateritic type of weathering. The chemical composition of studied sediments reflects semiarid to humid paleoclimate that the granitoids of the Brno Massif as parent rock have undergone.

scholarly journals The laboratory tests of hybrid layers combining hardfacing and nitriding dedicated to increase the durability of forging tools in hot forging processes

2019 ◽  
Vol 91 (2) ◽  
Author(s):  
Paweł Widomski ◽  
Zbigniew Gronostajski ◽  
Marcin Kaszuba ◽  
Jagoda Kowalska ◽  
Mariusz Pawełczyk
Keyword(s):  
Surface Layer ◽  
Chemical Composition ◽  
Laboratory Tests ◽  
Hot Forging ◽  
Composition Analysis ◽  
Wear Resistant ◽  
Gas Nitriding ◽  
Use Wear ◽  
Different Types ◽  
Hybrid Layers

In response to the growing need to use wear-resistant layers that increase durability of tools in forging pro-cesses, hybrid layers have been proposed that combine hardfacing with nitriding treatment. This article presents the results of laboratory tests of surface wear-resistant layers made with a new hybrid technology Gas-Shielded Metal Arc surfacing (hardfacing) with ZeroFlow gas nitriding. Specimens made with hardfacing or nitriding were prepared and examined. Analysis covered the thorough microstructure study, EDX chemical composition analysis and microhardness analysis. In experiment, 3 different types of nitrided layers were proposed for alpha, gamma prim and epsilon nitrides in the surface layer. The results of metallographic research in the surface layer was presented. The analysis of chemical composition in the particular overlay welds was performed to determine the content of alloying elements in the particular overlay welds. The susceptibility to nitriding of used weld materials as well as the ability to form particular types of nitrides on selected welded substrates was also tested.

scholarly journals The sensory acceptability of a tilapia (Oreochromis niloticus) mechanically separated meat-based spread

2012 ◽  
Vol 15 (2) ◽  
pp. 166-173 ◽  
Author(s):  
Daniela De Grandi Castro Freitas ◽  
Alda Letícia da Silva Santos Resende ◽  
Angela Aparecida Lemos Furtado ◽  
Luana Tashima ◽  
Henrique Muniz Bechara
Keyword(s):  
Chemical Composition ◽  
Oreochromis Niloticus ◽  
Raw Material ◽  
Common Salt ◽  
Microbiological Analysis ◽  
Sensory Acceptability ◽  
Different Types ◽  
Adequate Quality ◽  
Mechanically Separated Meat ◽  
Hedonic Scale

Mechanically Separated Meat (MSM) is an alternative for the diversification of new fish-based products and also as a solution for the use of waste from the filleting industries. Tilapia MSM was used in this study for the formulation of a fish spread aimed at investigating its acceptability by consumers. Two spread formulations were prepared with different types of commercial salt: seasoned salt (A) and common salt (B). The consumers (112) evaluated their acceptance with respect to overall impression, spreadability, appearance and flavour acceptability on a 9-point hedonic scale. A microbiological analysis of the Tilapia MSM was also carried out and the chemical composition of the Tilapia MSM-based spread determined. When considering the acceptance of all the consumers, the overall impression, appearance and flavour were significantly (P < 0.05) lower for the spread made with common salt (B). However, three different consumer segments could be found from the overall impression of the Tilapia MSM-based spread. The largest segment also preferred the spread made with the seasoned salt (A), but both products were well accepted. The tilapia MSM presented adequate quality as a raw material according to the technical regulations for microbiological standards. The final product presented the following chemical composition: moisture - 62.17%; ash - 2.11%; protein - 9.75% and lipid - 18.81%. These results could be of great importance for the industry in developing and marketing new products obtained from mechanically separated Tilapia meat.

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