scholarly journals Chemical characterization of archaeological pottery of the Lower Paraná River

Cerâmica ◽  
2019 ◽  
Vol 65 (374) ◽  
pp. 319-326
Author(s):  
D. Loponte ◽  
J. Morales ◽  
A. Gogichaishvili ◽  
A. Acosta
Keyword(s):  
Chemical Composition ◽  
Late Holocene ◽  
Chemical Characterization ◽  
Hunter Gatherers ◽  
X Ray ◽  
Archaeological Pottery ◽  
Main Components ◽  
Fluorescence Spectrometer ◽  
Concentration Levels

Abstract This paper analyzed the chemical composition of archaeological pottery produced by hunter-gatherers and horticulturist populations of the late Holocene of the lower Paraná basin. An energy dispersive X-ray fluorescence spectrometer was used to analyze the chemical composition of the sherds. The results obtained indicated that the analyzed samples, within certain parameters, showed some variability. The differences were even more significant when comparing the chemical composition of the pottery of the hunter-gatherer groups and that of the horticulturists. The main components identified in the archaeological pottery were grouped primarily with the location of production, that is, they were the result of local manufacturing. Within the trace-elements, the greatest variations in composition were observed in the strontium, which was assumed to vary in concentration levels throughout the region.

scholarly journals Nanotechnology in Roman Opaque Red Glass from the 2nd Century AD. Archaeometric Investigation in Red Sectilia from the Decoration of the Lucius Verus Villa in Rome

Heritage ◽  
2019 ◽  
Vol 2 (3) ◽  
pp. 2597-2611 ◽  
Author(s):  
Mario Bandiera ◽  
Patrice Lehuédé ◽  
Marco Verità ◽  
Luis Alves ◽  
Isabelle Biron ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Chemical Characterization ◽  
Second Step ◽  
Colorimetric Analysis ◽  
Historical Sources ◽  
Pixe Analysis ◽  
X Ray ◽  
Colorimetric Measurements ◽  
Shed Light

This work aims to characterise the chemical composition of Roman opaque red glass sectilia dated to the 2nd century A.D and to shed light on Roman glassmaking production of different shades of red, from red to reddish-brown. Due to the lack of technical historical sources for this period many questions about technological aspects still remain. In this project a multi-disciplinary approach is in progress to investigate the red glass sectilia with several red hues from the Imperial Villa of Lucius Verus (161–169 A.D.) in Rome. First, colorimetric measurements were taken to identify the various red hues. The second step was chemical characterization of the samples and the identification of crystalline colouring phases. Particle Induced X-Ray Emission (PIXE) analysis was used to investigate the chemical composition of these glass samples, while the crystalline phases were identified by Raman Spectroscopy and Scanning Electrons Microscope with Energy Dispersive X-ray Spectrometry (SEM-EDS). Using SEM-EDS nanoparticles were detected as a colouring agent, the chemical composition and the morphology of which has been studied in depth. This information has been compared with the colorimetric analysis to establish any correlation with the different colour hues.

scholarly journals New Insights into the Crystal Chemistry of Elpidite, Na2Zr[Si6O15]·3H2O and (Na1+YCax□1−X−Y)Σ=2Zr[Si6O15]·(3−X)H2O, and Ab Initio Modeling of IR Spectra

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2160
Author(s):  
Alexander Bogdanov ◽  
Ekaterina Kaneva ◽  
Roman Shendrik
Keyword(s):  
Ir Spectra ◽  
Structural Models ◽  
Chemical Characterization ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
Special Group ◽  
X Ray ◽  
Influence Of Water ◽  
Radioactive Species

Elpidite belongs to a special group of microporous zirconosilicates, which are of great interest due to their capability to uptake various molecules and ions, e.g., some radioactive species, in their structural voids. The results of a combined electron probe microanalysis and single-crystal X-ray diffraction study of the crystals of elpidite from Burpala (Russia) and Khan-Bogdo (Mongolia) deposits are reported. Some differences in the chemical compositions are observed and substitution at several structural positions within the structure of the compounds are noted. Based on the obtained results, a detailed crystal–chemical characterization of the elpidites under study was carried out. Three different structure models of elpidite were simulated: Na2ZrSi6O15·3H2O (related to the structure of Russian elpidite), partly Ca-replaced Na1.5Ca0.25ZrSi6O15·2.75H2O (close to elpidite from Mongolia), and a hypothetical CaZrSi6O15·2H2O. The vibration spectra of the models were obtained and compared with the experimental one, taken from the literature. The strong influence of water molecule vibrations on the shape of IR spectra of studied structural models of elpidite is discussed in the paper.

scholarly journals Characterization of calcium oxide in root perforation sealer materials

2012 ◽  
Vol 23 (5) ◽  
pp. 539-546 ◽  
Author(s):  
Carlos Estrela ◽  
Manoel Damião Sousa-Neto ◽  
Orlando Aguirre Guedes ◽  
Ana Helena Gonçalves Alencar ◽  
Marco Antonio Hungaro Duarte ◽  
...  
Keyword(s):  
Calcium Oxide ◽  
Mineral Trioxide Aggregate ◽  
Chemical Compounds ◽  
Internal Diameter ◽  
X Ray ◽  
Final Sample ◽  
Materials Used ◽  
Main Components ◽  
White Mineral

Root perforation represents an undesirable complication that may lead to an unfavorable prognosis. The aims of this study were to characterize and to compare the presence of calcium oxide (CaO) on the chemical composition of materials used for root perforation therapy: gray and white mineral trioxide aggregate (MTA) and Portland cement (PC), gray MTA+5%CaO and gray MTA+10%CaO. The last two materials were analyzed to evaluate the increase of CaO in the final sample. CaO alone was used as a standard. Eighteen polyethylene tubes with an internal diameter of 3 mm and 3 mm in length were prepared, filled and then transferred to a chamber with 95% relative humidity and a temperature of 37ºC. The chemical compounds (particularly CaO) and the main components were analyzed by energy-dispersive X-ray microanalysis (EDX). EDX revealed the following concentrations of CaO: gray MTA: 59.28%, white MTA: 63.09%; PC: 72.51%; gray MTA+5%CaO: 63.48% and gray MTA+10%CaO: 67.55%. The tested materials presented different concentrations of CaO. Even with an increase of 5 and 10% CaO in gray MTA, the CaO levels found in the MTA samples were lower than those found in PC.

Influence of the Residue of Casting by Lost Wax in the Modulus of Elasticity and Porosity of Concretes

2014 ◽  
Vol 805 ◽  
pp. 343-349
Author(s):  
Carine F. Machado ◽  
Weber G. Moravia
Keyword(s):  
Construction Industry ◽  
Modulus Of Elasticity ◽  
Chemical Characterization ◽  
Microstructural Characterization ◽  
Cement Matrix ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardened State ◽  
Material Powder

This work evaluated the influence of additions of the ceramic shell residue (CSR), from the industries of Lost Wax Casting, in the modulus of elasticity and porosity of concrete. The CSR was ground and underwent a physical, chemical, and microstructural characterization. It was also analyzed, the environmental risk of the residue. In the physical characterization of the residue were analyzed, the surface area, and particle size distribution. In chemical characterization, the material powder was subjected to testing of X-ray fluorescence (XRF). Microstructural characterization was performed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The residue was utilized like addition by substitution of cement in concrete in the percentages of 10% and 15% by weight of Portland cement. It was evaluated properties of concrete in the fresh and hardened state, such as compressive strength, modulus of elasticity, absorption of water by total immersion and by capillarity. The results showed that the residue can be used in cement matrix and improve some properties of concrete. Thus, the CSR may contribute to improved sustainability and benefit the construction industry.

Qualitative and Quantitative Characterization of Airport-related Ultrafine Particles using Liquid Chromatography – High-Resolution Mass Spectrometry (UHPLC/HRMS)

2021 ◽  
Author(s):  
Florian Ungeheuer ◽  
Diana Rose ◽  
Dominik van Pinxteren ◽  
Florian Ditas ◽  
Stefan Jacobi ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Ultrafine Particles ◽  
Chemical Characterization ◽  
Engine Oil ◽  
Aircraft Emissions ◽  
Jet Engine ◽  
Qualitative And Quantitative ◽  
Ionization Mode ◽  
Lubrication Oils

<p>We present the results from a chemical characterization study of ultrafine particles (UFP), collected nearby Frankfurt International Airport where particle size distribution measurements showed high number concentrations for particles with a diameter <50 nm. Aluminium filter samples were collected at an air quality monitoring station in a distance of 4 km to Frankfurt airport, using the 13-stage cascade impactor Nano-MOUDI (MSP Model-115). The chemical characterization of the ultrafine particles in the size range of 0.010-0.018 μm, 0.018-0.032 μm and 0.032-0.056 μm was accomplished by the development of an optimized filter extraction method. An UHPLC method for chromatographic separation of homologous series of hydrophobic and high molecular weight organic compounds, followed by heated electrospray ionization (ESI) and mass analysis using an Orbitrap high-resolution mass spectrometer was developed. Using a non-target screening, ~200 compounds were detected in the positive ionization mode after filtering, in order to ensure high quality of the obtained data. We determined the molecular formula of positively charged adducts ([M+H]<sup>+</sup>; [M+Na]<sup>+</sup>), and for each impaction stage we present molecular fingerprints (Molecular weight vs Retention time, Kroll-diagram, Van-Krevelen-diagram, Kendrick mass defect plot) in order to visualize the complex chemical composition. The negative ionization mode led only to the detection of a few compounds (<20) for which reason the particle characterization focuses on the positive ionization mode. We found that the majority of detected compounds belong to homologous series of two different kinds of organic esters, which are base stocks of aircraft lubrication oils. In reference to five different jet engine lubrication oils of various manufacturers, we identified the corresponding lubricant base stocks and their additives in the ultrafine particles by the use of matching retention time, exact mass and MS/MS fragmentation pattern of single organic molecules. As the relevance of the chemical composition of UFP regarding human health is depending on the mass contribution of each compound we strived for quantification of the jet engine oil compounds. This was achieved by standard addition of purchased original standards to the native sample extracts. Two amines serving as stabilizers, one organophosphate used as an anti-wear agent/metal deactivator and two ester base stocks were quantified. Quantification of the two homologous ester series was carried out using one ester compound and cross-calibration. The quantitative determination is burdened by the uncertainty regarding sampling artefacts in the Nano-MOUDI. Therefore we characterized the cascade impactor in a lab experiment using the ester standard. Particle size distribution measurements conducted parallel to the filter sampling enables the determination of jet engine oil contribution to the UFP mass. Results indicate that aircraft emissions strongly influence the mass balance of 0.010-0.018 μm particles. This contribution decreases for bigger sized particles (0.018-0.056 μm) as presumably more sources get involved. The hereby-introduced method allows the qualitative and quantitative assignment of aircraft emissions towards the chemical composition and total mass of airport related ultrafine particles.</p>

Current Questions and New Directions in Archaeological Obsidian Studies

2016 ◽  
Author(s):  
Carolyn Dillian
Keyword(s):  
Chemical Characterization ◽  
Current Status ◽  
Formation Processes ◽  
X Ray ◽  
Dating Methods ◽  
New Directions ◽  
Trade And Exchange

This article discusses the current status of archaeological obsidian studies, including techniques used in characterization and sourcing studies, obsidian hydration, and regional syntheses. It begins with an overview of obsidian and the unique formation processes that create it before turning to a discussion of the significance of characterization and sourcing techniques for understanding prehistoric obsidian trade and exchange. It then considers the problematic aspects of the term “sourcing,” despite its ubiquitous use in archaeology and archaeometry, along with the use of X-ray fluorescence in the chemical characterization of obsidian. It also explores obsidian hydration dating methods and equations, factors that can affect the date assignments for hydration specimens, and the various uses of obsidian in prehistoric times. Finally, it addresses some important questions relating to obsidian research and suggests new directions in the field.

Analysis of CoCrMo Surface Oxide Removal by Alumina Blasting before Porcelain Firing in Dental Restorations

2012 ◽  
Vol 730-732 ◽  
pp. 9-14 ◽  
Author(s):  
Bruno Henriques ◽  
Filipe Silva ◽  
Delfim Soares
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Chemical Composition ◽  
High Alumina ◽  
X Ray ◽  
Dental Restorations ◽  
Ceramic Bond ◽  
Xrf Scanning ◽  
Oxide Removal

The purpose of this work was to perform a chemical and mechanical characterization of a preoxidized CoCrMo alumina blasted surface. This is a commonly performed surface treatment used in metal-porcelain systems for dental restorations to remove oxides formed during preoxidation heat treatment from the metal’s surface. CoCrMo dental alloy’s specimens produced by lost wax process were examined in terms of chemical composition using X-Ray fluorescence spectroscopy (XRF), Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS); in terms of mechanical characteristics through the means of a microhardness test and in terms of surface roughness using a profilometer. It was investigated the chemical composition of various surface conditions: non-preoxidized, preoxidized, ground oxidized surface and sandblasted oxidized surface. After alumina blasting, the oxides level on metal’s surface remained high. Alumina blasting treatment (Ø110 µm) produced an 84% increase of CoCrMo surface hardening and an increase in surface roughness (Ra=0.58 µm). It was found alumina contaminants on the metal’s surface. Therefore, it was concluded that alumina blasting do not entirely removes the oxide layer formed during preoxidation heat treatment. It produced a chemical and mechanical surface modification that can influence the metal-ceramic bond strength.

Handheld Portable Energy-Dispersive X-Ray Fluorescence Spectrometry (pXRF)

2016 ◽  
pp. 362-381 ◽  
Author(s):  
Elisabeth Holmqvist
Keyword(s):  
Production Systems ◽  
Matrix Effects ◽  
Chemical Characterization ◽  
High Sensitivity ◽  
Limited Range ◽  
Energy Dispersive ◽  
Analytical Sensitivity ◽  
X Ray ◽  
Non Destructive

Handheld portable energy-dispersive X-ray fluorescence (pXRF) spectrometry is used for non-destructive chemical characterization of archaeological ceramics. Portable XRF can provide adequate analytical sensitivity to discriminate geochemically distinct ceramic pastes, and to identify compositional clusters that correlate with data patterns acquired by NAA or other high sensitivity techniques. However, successful non-destructive analysis of unprepared inhomogeneous ceramic samples requires matrix-defined scientific protocols to control matrix effects which reduce the sensitivity and precision of the instrumentation. Quantification of the measured fluorescence intensities into absolute concentration values and detection of light elements is encumbered by the lack of matrix matched calibration and proper vacuum facilities. Nevertheless, semi-quantitative values for a limited range of high Z elements can be generated. Unstandardized results are difficult to validate by others, and decreased analytical resolution of non-destructive surface analysis may disadvantage site-specific sourcing, jeopardize correct group assignments, and lead to under-interpretation of ceramic craft and production systems.

scholarly journals GC-MS Chemical Characterization of Main Components of Smilax Domingensis Wild. in Cuba

2018 ◽  
Vol 5 (4) ◽  
pp. 79 ◽  
Author(s):  
Pilar A. Soledispa ◽  
José González ◽  
Armando Cuéllar ◽  
Julio Pérez ◽  
Max Monan
Keyword(s):  
Mass Spectra ◽  
Chemical Constituents ◽  
Chemical Characterization ◽  
Ethanolic Extract ◽  
Chemical Compounds ◽  
Chemical Components ◽  
Analytical Technique ◽  
Main Components ◽  
First Time

A preliminary chemical characterization of main components of ethanolic extract with dried rhizomes of Smilax domingensis Wid. that grow in Cuba was done using a GCMS-QP2010 Ultra Shimadzu and the mass spectra of the compounds found in the extract was matched with the National Institute of Standards and Technology (NIST) library. After sample derivatization 125 chemical compounds were registered by the equipment and from them, 35 different chemical components were characterized and reported for the first time from this part of the plant in our country. The results demonstrate the developed method could be employed as a rapid and versatile analytical technique for identification of chemical constituents and quality control of Smilax domingensis.

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