Rapid, direct and non-destructive assessment of fossil organic matter via microRaman spectroscopy

The main aim of this study was to determine the intensity of hydrophobic/hydrophilic components of the soil’s organic matter as well as its hydrophobicity. Non-destructive Fourier Transform Infrared (FTIR) spectroscopy was used for the diagnosis and characterization of the basic classes of the chemical groups (hydrophilic and hydrophobic components) from which the organic matter in the soils is formed. Soil samples (depth 0–30 cm) were taken from the topsoil of the 70 sampling sites from the experimental field at Prague-Ruzyne (Czech Republic) during 2007–2009, where a conventional soil tillage technology was used. It was found that the variability of the intensity of the hydrophobic components is greater (27.6%) than that of the intensity of the hydrophilic components (6.2%), which correlated significantly with the C<sub>org</sub> (r = 0.58; P < 0.05) and N<sub>t</sub> (r = 0.65; P < 0.05) in the soil. It was proven that the soil samples with a higher proportion of coarse grains are more hydrophobic than those with higher proportions of clay. Data about soil hydrophobicity can help to evaluate the soil quality parameters as well as the soil fertility.  

Download Full-text

Characterization of insoluble organic matter in primitive meteorites by microRaman spectroscopy

Meteoritics and Planetary Science ◽

10.1111/j.1945-5100.2007.tb00581.x ◽

2007 ◽

Vol 42 (7-8) ◽

pp. 1387-1416 ◽

Cited By ~ 197

Author(s):

Henner Busemann ◽

M. O'D. Alexander ◽

Larry R. Nittler

Keyword(s):

Organic Matter ◽

Insoluble Organic Matter ◽

Microraman Spectroscopy

Download Full-text

A new methodology exploring the record of snow avalanches in lake sediments

10.5194/esurf-2016-25 ◽

2016 ◽

Author(s):

Laurent Fouinat ◽

Pierre Sabatier ◽

Jérôme Poulenard ◽

Jean-Louis Reyss ◽

Xavier Montet ◽

...

Keyword(s):

Organic Matter ◽

Global Change ◽

Lake Sediments ◽

Sediment Cores ◽

Ct Scanning ◽

Ct Scans ◽

Snow Avalanches ◽

X Ray ◽

Steep Slopes ◽

Non Destructive

Abstract. In recent years, wet avalanche deposits have become a subject of increasing concern in a context of both global change and winter mountain tourism activities. This study focuses on the use of a new methodology based on CT scans to identify snow avalanche deposits in lake sediment. Here, we study the mid-elevation Lake Lauvitel system (western French Alps), which features steep slopes and avalanche corridors. CT scanning is a fast, non-destructive method based on X-ray technology and allows the identification of elements with different densities. We applied this method to sediment cores, leading to the 3D identification of the dense rocks and organic matter macroremains that characterize wet avalanches. A total of eight periods of higher avalanche activity are identified since AD 1880 at the site. This new methodology is suitable for avalanche deposit reconstruction and may be applicable more widely in paleolimnological studies.

Download Full-text

Assessing Thermal Maturity through a Multi-Proxy Approach: A Case Study from the Permian Faraghan Formation (Zagros Basin, Southwest Iran)

Geosciences ◽

10.3390/geosciences11120484 ◽

2021 ◽

Vol 11 (12) ◽

pp. 484

Author(s):

Amalia Spina ◽

Simonetta Cirilli ◽

Andrea Sorci ◽

Andrea Schito ◽

Geoff Clayton ◽

...

Keyword(s):

Organic Matter ◽

Vitrinite Reflectance ◽

Optical Methods ◽

Thermal Maturity ◽

Zagros Basin ◽

Thermal Alteration ◽

Uv Fluorescence ◽

Rock Eval ◽

Southwest Iran ◽

Microraman Spectroscopy

This study focuses on the thermal maturity of Permian deposits from the Zagros Basin, Southwest Iran, employing both optical methods (Thermal Alteration Index, Palynomorph Darkness Index, Vitrinite Reflectance, UV Fluorescence) and geochemical analyses of organic matter (Rock Eval Pyrolysis and MicroRaman spectroscopy) applied to the Faraghan Formation along two investigated Darreh Yas and Kuh e Faraghan surface sections. Furthermore, an integrated palynofacies and lithofacies analysis was carried out in order to integrate the few studies on the depositional environment. The Faraghan Formation, which is widely distributed in the Zagros area, generally consists of shale intercalated with sandstones and pebble conglomerates in the lower part, followed by a succession of sandstone, siltstone and shaly intercalations and with carbonate levels at the top. The integrated palynofacies and lithofacies data confirm a coastal depositional setting evolving upwards to a shallow marine carbonate environment upwards. Rock Eval Pyrolysis and Vitrinite Reflectance analysis showed that the organic matter from samples of the Darreh Yas and Kuh e Faraghan sections fall in the mature to postmature range with respect to the oil to gas generation window, restricting the thermal maturity range proposed by previous authors. Similar results were obtained with MicroRaman spectroscopy and optical analysis such as Thermal Alteration Index and UV Fluorescence. Palynomorph Darkness Index values were compared with Rock Eval Pyrolysis and vitrinite reflectance values and discussed for the first time in the late stage of oil generation.

Download Full-text

Influence of Saturated Organic Matter on the Accuracy of In-Situ Measurements Recorded with a Nuclear Moisture and Density Gauge

Croatian journal of forest engineering ◽

10.5552/crojfe.2021.762 ◽

2021 ◽

Vol 42 (2) ◽

Author(s):

Eric R. Labelle ◽

Dirk Jaeger

Keyword(s):

Organic Matter ◽

Soil Moisture ◽

Moisture Content ◽

Bulk Density ◽

Forest Soils ◽

Mineral Soil ◽

Soil Bulk Density ◽

Organic Layer ◽

Correction Factors ◽

Non Destructive

The impact of machines on forest soils is regularly assessed and quantified using absolute bulk density, which is most frequently obtained by soil cores. However, to allow for repeated measurements at the exact same locations, non-destructive devices are increasingly being used to determine soil bulk density and moisture content in field studies. An example of such a device is a nuclear moisture and density gauge (NMDG), originally designed as a control measurement for soil bulk density and moisture content in geotechnical applications. Unlike road construction or foundation projects that use mineral soil or gravel, forest soils have complex structures and the presence of organic matter, which can skew moisture and density readings from a NMDG. To gain further knowledge in this respect, we performed controlled tests in a sandbox to quantify the influence of varying amounts of saturated organic matter (3, 5, 10, and 15%) mixed with mineral soil in different layers (0–5, 0–10, 0–20 and 0–40 cm) on the accuracy of soil moisture content obtained by a NMDG and soil theta probe at varying depths. Main results illustrated that the presence of saturated organic matter per se was not problematic but moisture content overestimations and related underestimation of dry bulk density occurred when the tested measurement depth was below the created organic layer. Since forest soils often exhibit higher organic matter contents in the upper horizon, correction factors are suggested to minimize the moisture content variations between NMDG and reference method. With the use of correction factors, NMDG can present a non-destructive, fast, and accurate method of measuring soil moisture and bulk density in forestry applications.

Download Full-text

Luminescence from individual dislocations in II-VI and III-V semiconductors

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100088488 ◽

1991 ◽

Vol 49 ◽

pp. 834-835

Author(s):

J W Steeds

Keyword(s):

Group Iv ◽

Luminescence Properties ◽

Carrier Recombination ◽

Transmission Electron ◽

Wide Range ◽

Basic Physics ◽

Semiconducting Compounds ◽

Diamond Group ◽

Non Destructive ◽

Technological Significance

There is a wide range of experimental results related to dislocations in diamond, group IV, II-VI, III-V semiconducting compounds, but few of these come from isolated, well-characterized individual dislocations. We are here concerned with only those results obtained in a transmission electron microscope so that the dislocations responsible were individually imaged. The luminescence properties of the dislocations were studied by cathodoluminescence performed at low temperatures (~30K) achieved by liquid helium cooling. Both spectra and monochromatic cathodoluminescence images have been obtained, in some cases as a function of temperature.There are two aspects of this work. One is mainly of technological significance. By understanding the luminescence properties of dislocations in epitaxial structures, future non-destructive evaluation will be enhanced. The second aim is to arrive at a good detailed understanding of the basic physics associated with carrier recombination near dislocations as revealed by local luminescence properties.

Download Full-text

Forensic Identifications Aided by Scanning Electron Microscopy of Silicone-Epoxy Microreplicas of Calcified and Cornified Structures

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100117017 ◽

1975 ◽

Vol 33 ◽

pp. 678-679 ◽

Cited By ~ 3

Author(s):

R.F. Sognnaes

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Forensic Science ◽

George Washington ◽

Epithelial Surface ◽

Extended Application ◽

Tissue Surfaces ◽

Non Destructive ◽

Scanning Electron ◽

Surface Changes

Sufficient experience has been gained during the past five years to suggest an extended application of microreplication and scanning electron microscopy to problems of forensic science. The author's research was originally initiated with a view to develop a non-destructive method for identification of materials that went into objects of art, notably ivory and ivories. This was followed by a very specific application to the identification and duplication of the kinds of materials from animal teeth and tusks which two centuries ago went into the fabrication of the ivory dentures of George Washington. Subsequently it became apparent that a similar method of microreplication and SEM examination offered promise for a whole series of problems pertinent to art, technology and science. Furthermore, what began primarily as an application to solid substances has turned out to be similarly applicable to soft tissue surfaces such as mucous membranes and skin, even in cases of acute, chronic and precancerous epithelial surface changes, and to post-mortem identification of specific structures pertinent to forensic science.

Download Full-text