scholarly journals μXRF Mapping as a Powerful Technique for Investigating Metal Objects from the Archaeological Site of Ferento (Central Italy)

2020 ◽  
Vol 6 (7) ◽  
pp. 59
Author(s):  
Giuseppe Capobianco ◽  
Adriana Sferragatta ◽  
Luca Lanteri ◽  
Giorgia Agresti ◽  
Giuseppe Bonifazi ◽  
...  
Keyword(s):  
Chemical Elements ◽  
Central Italy ◽  
Principal Component ◽  
Archaeological Site ◽  
Point Of View ◽  
Multivariate Curve Resolution ◽  
Polycapillary Optics ◽  
X Ray ◽  
Minor Elements ◽  
Major Chemical

This research concerns the application of micro X-ray fluorescence (µXRF) mapping to the investigation of a group of selected metal objects from the archaeological site of Ferento, a Roman and then medieval town in Central Italy. Specifically, attention was focused on two test pits, named IV and V, in which metal objects were found, mainly pertaining to the medieval period and never investigated before the present work from a compositional point of view. The potentiality of µXRF mapping was tested through a Bruker Tornado M4 equipped with an Rh tube, operating at 50 kV, 500 μA, and spot 25 μm obtained with polycapillary optics. Principal component analysis (PCA) and multivariate curve resolution (MCR) were used for processing the X-ray fluorescence spectra. The results showed that the investigated items are characterized by different compositions in terms of chemical elements. Three little wheels are made of lead, while the fibulae are made of copper-based alloys with varying amounts of tin, zinc, and lead. Only one ring is iron-based, and the other objects, namely a spatula and an applique, are also made of copper-based alloys, but with different relative amounts of the main elements. In two objects, traces of gold were found, suggesting the precious character of these pieces. MCR analysis was demonstrated to be particularly useful to confirm the presence of trace elements, such as gold, as it could differentiate the signals related to minor elements from those due to major chemical elements.

scholarly journals Archaeometric Approach for Studying Architectural Earthenwares from the Archaeological Site of S. Omobono (Rome-Italy)

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 266 ◽  
Author(s):  
Domenico Miriello ◽  
Fabrizio Antonelli ◽  
Andrea Bloise ◽  
Monica Ceci ◽  
Stefano Columbu ◽  
...  
Keyword(s):  
Compositional Data ◽  
Raw Materials ◽  
Principal Component ◽  
Archaeological Site ◽  
Electron Probe Micro Analysis ◽  
Geochemical Characterization ◽  
X Ray ◽  
Historic Center ◽  
Micro Analysis ◽  
The Church

This paper reports the findings of an archaeometric study performed on 14 architectural earthenwares from the archaeological site of S. Omobono, located in the historic center of Rome (Italy). The archaeological site, accidentally discovered in 1937, includes the remains of a sacred area previously occupied by two temples, one of which was converted into the church of S. Omobono, in 1575. The samples, dated between the 7th and the 6th century BC, belong to different sectors of the site. Their petrographic, mineralogical and geochemical characterization was performed by optical microscopy (OM), X-ray powder diffraction (XRPD), X-ray fluorescence (XRF), electron probe micro-analysis (EPMA), and Raman spectroscopy (RS). The compositional data obtained were also subjected to the principal component analysis (PCA) in order to highlight similarities and differences among the samples. By combining geochemical and petrographic data, we were able to identify several different fabrics. Furthermore, the study provided valuable information on the firing temperatures of some samples and the provenance of the raw materials, by analyzing the chemical composition of clinopyroxenes present as non-plastic inclusions.

scholarly journals Application of methods of ion-vacuum modification of working surfaces of carbide tools to improve their performance

2020 ◽  
Author(s):  
Ю.М. Зубарев ◽  
А.И. Круглов ◽  
М.А. Афанасенков
Keyword(s):  
Chemical Elements ◽  
Multilayer Coating ◽  
Experimental Studies ◽  
Mechanical Tests ◽  
Point Of View ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Cutting Zone ◽  
Fine Turning

В статье описаны механизмы разрушения кромок твердосплавных инструментов под влиянием сил резания в процессе обработки заготовок и воздействия окружающей среды. Рассмотрены варианты разрушения твердосплавных инструментов при обработке без применения СОТС в зоне резания. Приведен анализ основных причин потери работоспособности инструментов из металлокерамических твердых сплавов на операциях чистового точения и растачивания. Приведен анализ многокомпонентных покрытий, в состав которых входят различные комбинации химических элементов, с точки зрения их применимости в различных условиях обработки с учетом имеющихся недостатков таких покрытий. Представлена структура многослойного покрытия, позволяющая увеличить работоспособность металлокерамических твердосплавных инструментов в процессе механической обработки заготовок. Приведены результаты комплексных теоретических и экспериментальных исследований с применением современных методов компьютерного моделирования, рентгеноструктурного анализа, оптической и просвечивающей электронной микроскопии, а так же механических испытаний. The article describes the mechanisms of destruction of the edges of carbide tools under the influence of cutting forces in the processing of workpieces and environmental influences. The options for the destruction of carbide tools during processing without the use of SOTS in the cutting zone are considered. The analysis of the main reasons for the loss of operability of tools made of cermet carbides in the operations of fine turning and boring is given. The analysis of multicomponent coatings, which include various combinations of chemical elements, from the point of view of their applicability in various processing conditions, taking into account the existing disadvantages of such coatings, is given. The structure of a multilayer coating is presented, which allows to increase the performance of cermet carbide tools in the process of machining workpieces. The results of complex theoretical and experimental studies using modern methods of computer simulation, X-ray diffraction analysis, optical and transmission electron microscopy, as well as mechanical tests are presented.

scholarly journals Comparation of Pressed Powder Pellet and Fused Glass Bead Preparation Techniques for Mayor Elements Analysis of Rock Samples using X-Ray Fluorescence (XRF)

2020 ◽  
Vol 31 (2) ◽  
pp. 24-27
Author(s):  
Asep Rohiman ◽  
Agus Saiful Arifin
Keyword(s):  
Sample Preparation ◽  
Glass Bead ◽  
Chemical Elements ◽  
Preparation Technique ◽  
Standard Samples ◽  
X Ray ◽  
Rock Samples ◽  
Minor Elements ◽  
Rock Types ◽  
Analysis Process

The composition of chemical elements in rock samples can be used as a tool for classifying rock types, predicting the depositional environment, rock age, and the tectonic environment in which the rock is formed. X-Ray Fluorescence (XRF) is one of the instruments used to analyze rock samples. The advantage of using XRF analysis is that the analysis process can be done more quickly, easily, accurately, and does not damage the sample. However, before measurements are made using the XRF instrument it needs to be supported by an appropriate sample preparation process. In this study, optimal conditions in the standard (CRM) rock sample preparation of GBW 07105 and JR-1 have been studied. The parameters studied were variations in the composition ratio of Cellulose Mycro Crystalin (CMC) with standard (CRM) samples, namely 1: 4 and 1: 3. The technique of mixing the sample is done by using a mortar grinder and a shaker. Optimization of sample preparation was carried out using pressed powder pellet and fused glass bead techniques. Based on the data obtained from the analysis results the best ratio of binders to standard samples is 1: 3. The pressed powder pellet preparation technique is the best technique in analyzing samples using the X-Ray Fluorescence method. Further studies also need to be carried out to analyze minor elements and traces (REEs).

scholarly journals In situ X-ray absorption study of Cu species in Cu-CHA catalysts for NH3-SCR during temperature-programmed reduction in NO/NH3

2021 ◽  
Author(s):  
Chiara Negri ◽  
Elisa Borfecchia ◽  
Andrea Martini ◽  
Gabriele Deplano ◽  
Kirill A. Lomachenko ◽  
...  
Keyword(s):  
Catalytic Reduction ◽  
Principal Component ◽  
Multivariate Curve Resolution ◽  
Temperature Programmed Reduction ◽  
X Ray ◽  
Nh3 Scr ◽  
Pretreatment Conditions ◽  
Temperature Programmed ◽  
X Ray Absorption

AbstractAmmonia-mediated selective catalytic reduction (NH3-SCR) using Cu-exchanged chabazite zeolites as catalysts is one of the leading technologies for NOx removal from exhaust gases, with CuII/CuI redox cycles being the basis of the catalytic reaction. The amount of CuII ions reduced by NO/NH3 can be quantified by the consumption of NO during temperature-programmed reduction experiments (NO-TPR). In this article, we show the capabilities of in situ X-ray absorption near-edge spectroscopy (XANES), coupled with multivariate curve resolution (MCR) and principal component analysis (PCA) methods, in following CuII/CuI speciation during reduction in NO/NH3 after oxidation in NO/O2 at 50 °C on samples with different copper loading and pretreatment conditions. Our XANES results show that during the NO/NH3 ramp CuII ions are fully reduced to CuI in the 50–290 °C range. The number of species involved in the process, their XANES spectra and their concentration profiles as a function of the temperature were obtained by MCR and PCA. Mixed ligand ammonia solvated complexes [CuII(NH3)3(X)]+ (X = OH−/O− or NO3−) are present at the beginning of the experiment, and are transformed into mobile [CuI(NH3)2]+ complexes: these complexes lose an NH3 ligand and become framework-coordinated above 200 °C. In the process, multiple CuII/CuI reduction events are observed: the first one around 130 °C is identified with the reduction of [CuII(NH3)3(OH/O)]+ moieties, while the second one occurs around 220–240 °C and is associated with the reduction of the ammonia-solvated Cu-NO3− species. The nitrate concentration in the catalysts is found to be dependent on the zeolite Cu loading and on the applied pretreatment conditions. Ammonia solvation increases the number of CuII sites available for the formation of nitrates, as confirmed by infrared spectroscopy.

Large-Area X-Ray Micro-Fluorescence Imaging OF Heterogeneous Materials

1991 ◽  
Vol 35 (B) ◽  
pp. 1255-1264 ◽  
Author(s):  
B.J. Cross ◽  
R.D. Lamb ◽  
S. Ma ◽  
J.M. Paque
Keyword(s):  
Principal Components ◽  
Chemical Elements ◽  
Principal Component ◽  
Alloy Sample ◽  
Large Area ◽  
X Ray ◽  
Area 5 ◽  
Scatter Plots ◽  
The Many ◽  
Area X

AbstractAn X-ray Micro-Fluorescence (XRMF) spectrometer, with an analysis area of about 100 by 150 microns, has been used to collect 2-dimensional X-ray intensity maps over large-area (5 to 50 mm in X and Y) samples. These intensity maps were collected by scanning the sample on an XY stage, and converting X-ray Energy-Dispersive spectra to peak intensities for the elements of interest. The maps, when displayed using false-color or pseudogray scales, show the distribution of individual chemical elements over the analysis area. These maps can be collected at speeds from about 1 minute per frame (analysing 25 elements simultaneously). Greater precision of chemical intensities, or larger area maps, may require several hours, particularly if extensive data processing is performed at each point. XRMF has advantages over more conventional SEM-EDS X-ray mapping, including sample preparation and presentation, as well as improved signal-to-noise ratios.A technique is described which assists in analyzing the large amount of data which is collected in each map. Principal Component Analysis (PCA) is performed on all of the elemental maps simultaneously. This technique compresses the many elemental intensity maps into a few principal components, resulting in many fewer maps to evaluate. The intensity maps of these principal components display the most pertinent information. They can also be plotted as scatter plots which can help with the partitioning of the data into individual phases. This procedure can potentially be automated as a method for phase analysis. The selected pixels from the scatter plots can be averaged and converted into phase compositions, and the phase information re-displayed on the original elemental or principal component maps.This technique has been applied to a thin section of rock, and to a synthetic multiphase alloy sample.

Quantitative X-Ray Fluorescence Analysis for Fly Ash Samples

1983 ◽  
Vol 27 ◽  
pp. 497-504
Author(s):  
Scott Schlorholtz ◽  
Mustafa Boybay
Keyword(s):  
Fly Ash ◽  
Sample Preparation ◽  
Power Plants ◽  
Fluorescence Analysis ◽  
Complex Problem ◽  
Point Of View ◽  
Fly Ashes ◽  
X Ray ◽  
Minor Elements ◽  
Minimal Sample

The disposal of fly ash from coal burning power plants is rapidly becoming an environmentally complex problem. Recently though, the attitude towards fly ash use has been changing from a disposal oriented point of view to a more rational position which considers fly ash as a resource to be recycled. One major hinderance of fly ash use has been the extreme variability of composition that exists between fly ashes produced at different power plants. This variability makes the analysis of fly ash very important.The most common methods currently used for fly ash analysis are atomic absorption or wet chemistry methods defined in ASTM C311. Both methods tend to be expensive, time consuming, and sample preparation is both tedious and critical for some elements. In this study X-ray fluorescence (QXRF) is used for the quantitative analysis of the major and minor elements found in “typical” fly ashes. The method, which is computer controlled, is quick, reliable, and requires minimal sample preparation.

scholarly journals COMPARISON OF THE REAL IMAGE, RADIOGRAPHIC AND PROCESSED IMAGE IN THE STUDY OF METALLIC PIECES FROM ARCHAEOLOGICAL SITE

2021 ◽  
Author(s):  
Jose Madrid ◽  
Effat Yahaghi ◽  
José Manuel Melchor ◽  
Amir Movafeghic
Keyword(s):  
Archaeological Site ◽  
Point Of View ◽  
X Ray ◽  
The Real ◽  
Metal Type ◽  
Analysis Technique ◽  
Impulsive Response ◽  
Adequate Quality ◽  
Multidisciplinary Perspective

Archaeologists and conservators have different problems in inspecting metal-type pieces extracted from the archaeological sites, such as their large number and the complexity of the materials and their shapes. Usually, all of the pieces are hidden under the oxidation layers. From this point of view, a non-destructive analysis technique such as digital radiography imaging can detect and discriminate one piece from another. Also, the shape of pieces, state of the metal core, and assessment of its handling can be investigated. But there are still some problems with metal-type parts with a certain thickness. The generated X-ray image can be very foggy and without adequate quality. This will prevent the method to discriminate small details about the shape, hidden structures, and the real level of oxidation, and the presence of cracks. A solution for improving the quality of the x-ray image can be implementing a digital imaging processing algorithm for enhancing the quality of the radiographs. In this study, the metal parts are carried out from two important Iberian-Roman sites located on the coast of the municipality of Burriana (Castellón), i.e. Sant Gregori and Torre d'Onda. This set of pieces belong to the archaeological museum of Burriana, Spain, and are investigated by X-ray imaging. This study has used the “Fast 2D Gaussian convolution first-order infinite impulsive response” (IIR) to extract the maximum detail for better interpretation of the image. A multidisciplinary perspective has been desired for this study.

Scanning x-ray fluorescence microscopy and principal component analysis

1992 ◽  
Vol 50 (2) ◽  
pp. 1752-1753
Author(s):  
Brian Cross
Keyword(s):  
Principal Component Analysis ◽  
Fluorescence Microscopy ◽  
Spatial Resolution ◽  
High Speed ◽  
Image Acquisition ◽  
Principal Component ◽  
Fluorescence Microscope ◽  
Acquisition Rate ◽  
X Ray ◽  
Speed Up

A relatively new entry, in the field of microscopy, is the Scanning X-Ray Fluorescence Microscope (SXRFM). Using this type of instrument (e.g. Kevex Omicron X-ray Microprobe), one can obtain multiple elemental x-ray images, from the analysis of materials which show heterogeneity. The SXRFM obtains images by collimating an x-ray beam (e.g. 100 μm diameter), and then scanning the sample with a high-speed x-y stage. To speed up the image acquisition, data is acquired "on-the-fly" by slew-scanning the stage along the x-axis, like a TV or SEM scan. To reduce the overhead from "fly-back," the images can be acquired by bi-directional scanning of the x-axis. This results in very little overhead with the re-positioning of the sample stage. The image acquisition rate is dominated by the x-ray acquisition rate. Therefore, the total x-ray image acquisition rate, using the SXRFM, is very comparable to an SEM. Although the x-ray spatial resolution of the SXRFM is worse than an SEM (say 100 vs. 2 μm), there are several other advantages.

Specimen Preparation for Clinical Applications of X-Ray Microanalysis

1990 ◽  
Vol 48 (2) ◽  
pp. 328-329
Author(s):  
J.D. Shelburne ◽  
G.M. Roomans
Keyword(s):  
Carbon Coating ◽  
Clinical Applications ◽  
Point Of View ◽  
Practical Significance ◽  
Sweat Test ◽  
Specimen Preparation ◽  
Tissue Preparation ◽  
X Ray ◽  
Gallbladder Stones ◽  
Clinical Problems

Proper preparative procedures are a prerequisite for the validity of the results of x-ray microanalysis of biological tissue. Clinical applications of x-ray microanalysis are often concerned with diagnostic problems and the results may have profound practical significance for the patient. From this point of view it is especially important that specimen preparation for clinical applications is carried out correctly.Some clinical problems require very little tissue preparation. Hair, nails, and kidney and gallbladder stones may be examined and analyzed after carbon coating. High levels of zinc or copper in hair may be indicative of dermatological or systemic diseases. Nail clippings may be analyzed (as an alternative to the more conventional sweat test) to confirm a diagnosis of cystic fibrosis. X-ray microanalysis in combination with scanning electron microscopy has been shown to be the most reliable method for the identification of the components of kidney or gallbladder stones.A quantitatively very important clinical application of x-ray microanalysis is the identification and quantification of asbestos and other exogenous particles in lung.

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