Characterization of uranium ore concentrate chemical composition via Raman spectroscopy

2018 ◽  
Author(s):  
Timothy J. Johnson ◽  
Yin-Fong Su ◽  
Samuel A. Bryan ◽  
Lucas E. Sweet ◽  
Jordan F. Corbey ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Chemical Composition ◽  
Uranium Ore ◽  
Uranium Ore Concentrate

Nanocrystalline Alloys of II-VI Semiconductors from Molecular Multi-Layer Templates

1999 ◽  
Vol 581 ◽  
Author(s):  
L. Cristofolini ◽  
P. Facci ◽  
M.P. Fontana
Keyword(s):  
Raman Spectroscopy ◽  
Fatty Acid ◽  
Chemical Composition ◽  
Electronic Properties ◽  
Size Control ◽  
Fine Tuning ◽  
Synthesis And Characterization ◽  
Mixed Composition ◽  
Micro Raman Spectroscopy

ABSTRACTWe present the synthesis and characterization of nanocrystalline II-VI semiconductors of mixed composition (CdSe/ZnSe, CdS) grown in fatty acid Langmuir-Schaefer multi-layer templates. The controlled production of i) homogeneous nanocrystalline CdxZn1−xSe alloys and ii) heterogeneous mixtures of different pure composition II-VI semiconductors such as CdSe and ZnSe provides, in addition to the size control, the parameter of the chemical composition for the fine tuning of the electronic properties. The samples are characterized bty optical and quasi-resonance micro-Raman spectroscopy.

scholarly journals Detection, counting and characterization of nanoplastics in marine bioindicators: a proof of principle study

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Andrea Valsesia ◽  
Jeremie Parot ◽  
Jessica Ponti ◽  
Dora Mehn ◽  
Rita Marino ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Chemical Composition ◽  
Food Chain ◽  
Limit Of Detection ◽  
Polystyrene Spheres ◽  
Biological Matrices ◽  
Regulatory Bodies ◽  
Controlled Exposure ◽  
Proof Of Principle

AbstractPlastic particulates in the environment pose an increasing concern for regulatory bodies due to their potential risk to higher organisms (including humans) as they enter the food chain. Nanoplastics (defined here as smaller than 1 μm) are particularly challenging to detect and analyze at environmentally relevant concentrations and in biological matrices. The tunicate Ciona Robusta is an effective bioindicator for microplastics and nanoplastic contamination in the marine environment, due to its capacity to filter substantial volumes of water and to accumulate particulates. In this proof-of-principle study that demonstrates a complete methodology, following controlled exposure using spiked samples of a model nanoplastic (100 nm diameter polystyrene spheres) the nanoparticles were separated from an enzymatically digested biological matrix, purified and concentrated for analysis. The described method yields an approximate value for nanoplastic concentration in the organism (with a limit of detection of 106 particles/organism, corresponding to 1 ng/g) and provides the chemical composition by Raman spectroscopy. Furthermore, this method can be extended to other biological matrices and used to quantitatively monitor the accumulation of nanoplastics in the environment and food chain.

Raman spectroscopy as a novel tool for fast characterization of the chemical composition of perivascular adipose tissue

The Analyst ◽  
2018 ◽  
Vol 143 (24) ◽  
pp. 5999-6005 ◽  
Author(s):  
Krzysztof Czamara ◽  
Zuzanna Majka ◽  
Aleksandra Fus ◽  
Kamila Matjasik ◽  
Marta Z. Pacia ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Adipose Tissue ◽  
Chemical Composition ◽  
Therapeutic Potential ◽  
Adipose Tissues ◽  
Perivascular Adipose Tissue ◽  
New Targets ◽  
Lipid Unsaturation ◽  
Thoracic And Abdominal

One of the new targets of untapped therapeutic potential is perivascular adipose tissue (pVAT). Based on Raman spectroscopy we demonstrated that the lipid unsaturation degree was clearly distinct in various types of adipose tissues, in particular thoracic and abdominal pVATs, and was influenced by the age of animals.

Natural radionuclides 238U, 226RA, AND 222RN in the surface water of the ELKONSKY uranium-ore district (South Yakutiya)

2019 ◽  
Vol 46 (6) ◽  
pp. 613-620
Author(s):  
A. P. Chevychelov ◽  
P. I. Sobakin ◽  
L. I. Kuznetsova
Keyword(s):  
Chemical Composition ◽  
Surface Water ◽  
20Th Century ◽  
Radioactive Contamination ◽  
Raw Materials ◽  
Natural Radionuclides ◽  
Water Migration ◽  
Uranium Ore ◽  
Wide Scale ◽  
Ore District

Chemical composition of the surface water and the contents of the radionuclides 238U, 226Ra, and 222Rn in water was examined within the natural and man-made landscapes of South Yakutiya. It was demonstrated that intense water migration of these radionuclides from radioactive dump pits of the man-made landscapes of the Elkonsky uranium-ore district, which were created during the process of wide-scale exploration surveys for radioactive raw materials conducted during the last third of the 20th century, had occurred. Currently, the areas of water dissipation of 238U and 226Ra are detected at a distances of 2 km and greater from the source of the radioactive contamination along the outflow vector.

scholarly journals Morpho-molecular ex vivo detection and grading of non-muscle-invasive bladder cancer using forward imaging probe based multimodal optical coherence tomography and Raman spectroscopy

The Analyst ◽  
2020 ◽  
Vol 145 (4) ◽  
pp. 1445-1456 ◽  
Author(s):  
Fabian Placzek ◽  
Eliana Cordero Bautista ◽  
Simon Kretschmer ◽  
Lara M. Wurster ◽  
Florian Knorr ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Optical Coherence Tomography ◽  
Imaging System ◽  
Ex Vivo ◽  
Large Field ◽  
Optical Coherence ◽  
Fiber Optic Probe ◽  
Optic Probe ◽  
Muscle Invasive

Characterization of bladder biopsies, using a combined fiber optic probe-based optical coherence tomography and Raman spectroscopy imaging system that allows a large field-of-view imaging and detection and grading of cancerous bladder lesions.

scholarly journals Structural Factors Inducing Cracking of Brass Fittings

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3255
Author(s):  
Lenka Kunčická ◽  
Michal Jambor ◽  
Adam Weiser ◽  
Jiří Dvořák
Keyword(s):  
Chemical Composition ◽  
Plastic Flow ◽  
Beta Phase ◽  
Alpha Phase ◽  
Structural Factors ◽  
Transmission Electron ◽  
Medical Gas ◽  
Hot Die Forging ◽  
Multiple Step

Cu–Zn–Pb brasses are popular materials, from which numerous industrially and commercially used components are fabricated. These alloys are typically subjected to multiple-step processing—involving casting, extrusion, hot forming, and machining—which can introduce various defects to the final product. The present study focuses on the detailed characterization of the structure of a brass fitting—i.e., a pre-shaped medical gas valve, produced by hot die forging—and attempts to assess the factors beyond local cracking occurring during processing. The analyses involved characterization of plastic flow via optical microscopy, and investigations of the phenomena in the vicinity of the crack, for which we used scanning and transmission electron microscopy. Numerical simulation was implemented not only to characterize the plastic flow more in detail, but primarily to investigate the probability of the occurrence of cracking based on the presence of stress. Last, but not least, microhardness in specific locations of the fitting were examined. The results reveal that the cracking occurring in the location with the highest probability of the occurrence of defects was most likely induced by differences in the chemical composition; the location the crack in which developed exhibited local changes not only in chemical composition—which manifested as the presence of brittle precipitates—but also in beta phase depletion. Moreover, as a result of the presence of oxidic precipitates and the hard and brittle alpha phase, the vicinity of the crack exhibited an increase in microhardness, which contributed to local brittleness.

scholarly journals Raman Spectroscopy Investigation of Graphene Oxide Reduction by Laser Scribing

2021 ◽  
Vol 7 (2) ◽  
pp. 48
Author(s):  
Vittorio Scardaci ◽  
Giuseppe Compagnini
Keyword(s):  
Raman Spectroscopy ◽  
Graphene Oxide ◽  
Reduce Graphene Oxide ◽  
Oxide Reduction ◽  
Material Parameters ◽  
Laser Scribing ◽  
Wide Range ◽  
Scan Speed ◽  
Laser Reduction

Laser scribing has been proposed as a fast and easy tool to reduce graphene oxide (GO) for a wide range of applications. Here, we investigate laser reduction of GO under a range of processing and material parameters, such as laser scan speed, number of laser passes, and material coverage. We use Raman spectroscopy for the characterization of the obtained materials. We demonstrate that laser scan speed is the most influential parameter, as a slower scan speed yields poor GO reduction. The number of laser passes is influential where the material coverage is higher, producing a significant improvement of GO reduction on a second pass. Material coverage is the least influential parameter, as it affects GO reduction only under restricted conditions.

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