The mineralogy, trace and minor element geochemistry and different color changes of Bitlisignimbirite (eastern Turkey) were measured with Neutron Activation Analysis and Confocal Raman spectrometr methods. From these analyzes, were determined three levels as lower, middle and upper according to texture, color, welded degree, component and chemical differences in Bitlis ignimbrites in study area. The most distinguishing feature observed in black, red and grey color ignimbirite levels are partially mineralogical compositions, fiamme geometry and appearance of different colors. The mineralogical compositions of all levels are plagioclase, feldspar, augite, fayalite, biotite, sanidine, hematite and Fe-Ti oxide (titanomite, ilmenite) minerals. The matrix consists of quartz, anorthoclase, Fe-Ti oxide and sanidine. In addition, the matrix rarely contains glassy and dispersed mineral microliths, apart from intermediate levels of iron oxide/hydroxides. The intermediate levels have higher Fe-Ti oxide composition than others. The hydrous minerals in all ignimbrite levels have been partially replaced by devitrification minerals. The fayalite, which rarely seen in ignimbrites is determined by Raman spectroscopy method in Bitlis ignimbrite. The Raman spectra of different colored ignimbirites obtained using Confocal Raman spectroscopy showed different spectra between 869 and 3062 cm for the grey, black, and reddish colored ignimbirites. In spectral ID are determined anorthoclase, fayalite, hematite, bitovnite minerals. The REEs patterns of ignimbrites normalized to chondrite are similar each other. All of them show a decrease from high LREE to HREE. The LREE enrichment and La/Yb ratios (7.95-9.07) in ignimbrites is the sign of the liquid-rich calalkaline magmatic source. The cerium anomaly shows the decrease in solubility accompanying the oxidation of Ce (+3) to Ce (+4). The different color levels of ignimbrites can be summarized as cooling, iron oxide/iron hydroxides ratios (high in middle level), volatile elements (U,Th,Cl) (low in middle levell), devitrification of volcanic glass and chemical reactions.
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http://dx.doi.org/10.1016/j.saa.2020.119406 | DOI Listing |
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January 2025
Department of Chemistry, University of Victoria, Victoria, British Columbia, V8W 3V6, Canada.
Infrared absorption spectroscopy and surface-enhanced Raman spectroscopy were integrated into three data fusion strategies-hybrid (concatenated spectra), mid-level (extracted features from both datasets) and high-level (fusion of predictions from both models)-to enhance the predictive accuracy for xylazine detection in illicit opioid samples. Three chemometric approaches-random forest, support vector machine, and -nearest neighbor algorithms-were employed and optimized using a 5-fold cross-validation grid search for all fusion strategies. Validation results identified the random forest classifier as the optimal model for all fusion strategies, achieving high sensitivity (88% for hybrid, 92% for mid-level, and 96% for high-level) and specificity (88% for hybrid, mid-level, and high-level).
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January 2025
Department of Operative Dentistry, Faculty of Dentistry, Chulalongkorn University, 34 Henri Dunant Road, Pathumwan, Bangkok, 10330, Thailand.
To evaluate the effect of sulfinate salt on the bond performance of a two-step self-etch adhesive to an intracoronally bleached pulpal dentin surface. Intracoronally bleached bovine teeth were treated with or without sulfinate salt (sulfinate agent (SA): Clearfil DC activator) before 2-SEA (Clearfil SE Bond 2) application, while unbleached teeth served as the control (n = 5 teeth). Microtensile bond strength (µTBS) using the bonded surface area of 1 mm at the crosshead speed of 1 mm/min measurements after 24 h storage and thermocycles (TC), degree of conversion (DC) analyses by Raman spectroscopy (n = 3 teeth), ultrastructure of resin-dentin interface (n = 3 teeth), and intracoronally bleached pulp chamber dentin surface (n = 3 teeth) observations by scanning electron microscopy (SEM) were subsequently performed.
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January 2025
Department of Internal Medicine and Liver Research Institute, Department of Medical Device Development, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
This study aimed to identify biomolecular differences between benign gastric tissues (gastritis/intestinal metaplasia) and gastric adenocarcinoma and to evaluate the diagnostic power of Raman spectroscopy-based machine learning in gastric adenocarcinoma. Raman spectroscopy-based machine learning was applied in real-time during endoscopy in 19 patients (aged 51-85 years) with high-risk for gastric adenocarcinoma. Raman spectra were captured from suspicious lesions and adjacent normal mucosa, which were biopsied for matched histopathologic diagnosis.
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January 2025
Department of Biomedical Sciences, Graduate School of Science and Technology, Kwansei Gakuin University, Gakuen-Uegahara, Sanda, Hyogo, 669-1330, Japan.
Naturally weathered polypropylene (NWPP) samples are useful for investigating the effects of various degradation factors that cannot be obtained in artificial laboratory experiments. In this study, NWPP samples were extracted from beach sediments (Ashiya, Hyogo, Japan). Raman and attenuated total reflection (ATR)-Fourier-transform infrared (FTIR) spectroscopies were used to analyze variations in the composition, crystallinity, orientation, and degradation of NWPP microplastics.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University) Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, PR China. Electronic address:
Background: Sensitive and accurate detection of important cancer markers MicroRNAs (miRNAs) is critical to prevent and treat disease. Among many detection techniques, surface-enhanced Raman scattering(SERS) has attracted much attention due to its advantages such as narrow spectral peak, low interference and non-destructive detection. Interestingly, non-noble metal SERS substrates show good prospects due to their outstanding spectral reproducibility and biocompatibility.
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