Evaluation of X-Ray Microanalysis for Characterization of Dental Enamel

2014 ◽  
Vol 20 (1) ◽  
pp. 257-267 ◽  
Author(s):  
Lisa Melin ◽  
Jörgen G. Norén ◽  
Fabian Taube ◽  
David H. Cornell
Keyword(s):  
Dental Enamel ◽  
Variable Pressure ◽  
X Ray ◽  
Small Areas ◽  
Dental Hard Tissues ◽  
Sodium Magnesium ◽  
Bovine Enamel ◽  
Ray Series ◽  
Respective Characteristic

AbstractElemental analysis of dental hard tissues is of importance. The aim of this study is to evaluate X-ray microanalysis (XRMA) of bovine enamel in a scanning electron microscope (SEM) with different coatings. The buccal surface of bovine incisors was polished flat, one-third was coated with carbon, one-third with gold, leaving one-third uncoated for XRMA in an SEM equipped with an energy-dispersive microanalysis system. The elements oxygen, sodium, magnesium, phosphorous, chlorine, potassium, and calcium were analyzed using their respective characteristic K X-ray series. Comparisons were made with analyses of glass produced by fusion of the bovine enamel, showing that oxygen analyses using the K X-ray series are reliable and preferable to calculating oxygen by stoichiometry for natural enamel. For the gold-coated and uncoated analyses, carbon was also measured using the K X-ray series. Small area Analyses in small areas (80 × 80 μm) in variable pressure-SEM mode with low vacuum (20 Pa), without any coating, midway between 40 μm wide gold lines 140 μm apart to avoid build-up of electrostatic charge is the preferred method, especially if carbon is included in the analysis. The analyses of bovine enamel are sufficiently reproducible to be regarded as quantitative for all elements except carbon.

Synchrotron X-ray diffraction characterization of healthy and fluorotic human dental enamel

2012 ◽  
Vol 81 (10) ◽  
pp. 1578-1585 ◽  
Author(s):  
M.V. Colaço ◽  
R.C. Barroso ◽  
I.M. Porto ◽  
R.F. Gerlach ◽  
F.N. Costa ◽  
...  
Keyword(s):  
Dental Enamel ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Characterization of Small Areas of Thin-Films by Grazing-Exit Electron Probe X-ray Microanalysis

2002 ◽  
Vol 43 (3) ◽  
pp. 414-416 ◽  
Author(s):  
Kouichi Tsuji ◽  
Zoya Spolnik ◽  
Kazuaki Wagatsuma ◽  
Kesami Saito ◽  
Katsuhiko Asami
Keyword(s):  
Thin Films ◽  
Electron Probe ◽  
X Ray ◽  
Small Areas

Electron microscopic evaluation of radioactive particles collected near the Chernobyl nuclear reactor

1988 ◽  
Vol 46 ◽  
pp. 964-965
Author(s):  
G.L. Finch ◽  
R.G. Cuddihy ◽  
S.J. Rothenberg ◽  
F.F. Hahn
Keyword(s):  
Health Risks ◽  
Carbon Coating ◽  
Nuclear Reactor ◽  
Sample Surface ◽  
Bulk Sample ◽  
Electron Microscopic ◽  
X Ray ◽  
Small Areas ◽  
Microscopic Evaluation

In April, 1986, an accident at a nuclear reactor near Chernobyl, USSR, resulted in a substantial release of radioactivity into the environment. Characterization of the release is essential to permit estimates of health risks to exposed individuals. This study was conducted to characterize the nature of particles released during the accident and deposited on nearby surfaces.We obtained a sample of wood that was near the reactor at the time of the accident. Autoradiography of the bulk sample (surface area ≈ 125 cm2) showed the presence of about 30 radioactive particles. After microdissection of small areas of the wood matrix, mounting on carbon stubs, and evaporative carbon coating, samples were examined in a scanning electron microscope (SEM; JEOL JSM-35; operated at 20-30 kV in both backscattered [BSE] and secondary electron [SE] modes) equipped with an energy-dispersive x-ray microanalysis system (EDXA; Kevex 5100C). After EDXA, samples were recoated with gold for improved SE imaging.

Unveiling the Ambrotype: Characterization of Two 19th Century Photographs

2018 ◽  
Vol 25 (1) ◽  
pp. 203-213 ◽  
Author(s):  
Leonor Costa ◽  
Margarida Nunes ◽  
Sónia Costa ◽  
Milene Trindade ◽  
Catarina Miguel ◽  
...  
Keyword(s):  
19Th Century ◽  
Soda Lime ◽  
Variable Pressure ◽  
X Ray ◽  
Silica Glasses ◽  
Ring Shape ◽  
Point Analysis ◽  
Historical Objects ◽  
Raman Study

AbstractThis work used a multi-analytical approach to characterize two 19th century ambrotypes and was motivated by the lack of insight on these historical objects. Photographic imaging and optical microscopy (OM) were used to identify abrasions, cracks related to reticulation, tarnishing, and other aspects associated to production and degradation processes. With variable pressure scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (EDS) these processes were seen with great detail and further characterized. Elemental point analysis and elemental mapping showed that the photosensitive material used was silver iodide. Degradation compounds were found as silver and chlorine-containing compounds. In one of the items, the tarnishing area also contained redeposited silver in a ring-shape surrounding a nucleus rich in silver, copper, and sulfur, in addition to copper-based salts. EDS analyses also identified that the supports were common soda–lime–silica glasses, refined with arsenic; and showed that a pigment rich in iron was used in both items to hand color the cheeks, extended with aluminum silicates alone or mixed with barium sulfate. Theμ-Raman study pointed out that a synthetic Mars pigment was employed.μ-Fourier-transform infrared spectroscopy analyses identified collodion as the binder. Shellac was used as a protective varnish in one of the items and a gum was possibly employed on the other. Bitumen was used for the background in one ambrotype.

scholarly journals Influence of Homogenization and Micro/Nano Source of Starting Powders on Format Ion of the Single YAP Phase

2016 ◽  
Vol 61 (4) ◽  
pp. 1753-1760 ◽  
Author(s):  
D. Michalik ◽  
T. Pawlik ◽  
J. Plewa ◽  
M. Sopicka-Lizer
Keyword(s):  
Low Cost ◽  
Diffraction Method ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Small Areas ◽  
Oxide Powders ◽  
Heat Treated ◽  
Interesting Task

Abstract Manufacturing high purity polycrystalline YAlO3 (YAP) ceramics could replace monocrystalline YAP thus recently it is an interesting task for low cost producers of scintillators. The paper presents influence of different source of initial oxide powders (micro/nano powders of Y2O3 and Al2O3) and the method of their homogenization on the formation of a YAP phase. The solid state reaction method was used to prepare YAP powder or ceramic pellets. After preheating, all samples in the form of powders and pellets were heat-treated in the temperature range of 1050-1650 °C. DTA method was applied for examination of the phase crystallization in the tested system. X-ray diffraction method (XRD) was used for characterization of the phase composition. X-ray microanalysis (EDS) was used to control homogeneity in the small areas. Morphology of the resultant samples are presented on SEM pictures. The results show a significant influence of the starting powders on the homogeneity, purity and temperature of formation of the main phase.

scholarly journals How Many Secret Details Could a Systematic Multi-Analytical Study Reveal About the Mysterious Fresco Trionfo della Morte?

Heritage ◽  
2019 ◽  
Vol 2 (3) ◽  
pp. 2370-2383
Author(s):  
Alberghina ◽  
Schiavone ◽  
Greco ◽  
Saladino ◽  
Armetta ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Analytical Study ◽  
Multispectral Imaging ◽  
Imaging Analysis ◽  
X Ray ◽  
Small Areas ◽  
Non Invasive ◽  
History Of ◽  
Invasive Techniques

The “Trionfo della morte” is a detached fresco painting dated at the half of the XV century. Its history is strictly connected with the history of Palermo and it is considered a symbol of the late Gothic period. Some small areas of the fresco were analyzed using a combination of non-invasive techniques and hand-held instrumentations (multispectral imaging analysis, X-ray fluorescence (XRF), and IR spectroscopy). The characterization of the nature of pigments used in its realization and restoration works was performed and some indications about its conservation state were obtained. More interestingly, some hidden details were revealed on the mysterious painting. They constitute additional evidence of the preciousness of the fresco.

Mechanism of Action of TiF4 on Dental Enamel Surface: SEM/EDX, KOH-Soluble F, and X-Ray Diffraction Analysis

2017 ◽  
Vol 51 (6) ◽  
pp. 554-567 ◽  
Author(s):  
Lívia P. Comar ◽  
Beatriz M. Souza ◽  
Luana P. Al-Ahj ◽  
Jessica Martins ◽  
Larissa T. Grizzo ◽  
...  
Keyword(s):  
Dental Enamel ◽  
In Vitro Study ◽  
Xrd Analysis ◽  
Enamel Surface ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bovine Enamel ◽  
Fluoride Deposition

This in vitro study aimed to evaluate the action of TiF4 on sound and carious bovine and human enamel. Sound (S) and pre-demineralised (DE) bovine and human (primary and permanent) enamel samples were treated with TiF4 (pH 1.0) or NaF varnishes (pH 5.0), containing 0.95, 1.95, or 2.45% F for 12 h. The enamel surfaces were analysed using SEM-EDX (scanning electron microscopy/energy-dispersive X-ray spectroscopy) (n = 10, 5 S and 5 DE) and KOH-soluble fluoride was quantified (n = 20, 10 S and 10 DE). Hydroxyapatite powder produced by precipitation method was treated with the corresponding fluoride solutions for 1 min (n = 2). The formed compounds were detected using X-ray diffraction (XRD). All TiF4 varnishes produced a coating layer rich in Ti and F on all types of enamel surface, with micro-cracks in its extension. TiF4 (1.95 and 2.45% F) provided higher fluoride deposition than NaF, especially for bovine enamel (p < 0.0001). It also induced a higher fluoride deposition on DE samples compared to S samples (p < 0.0001), except for primary enamel. The Ti content was higher for bovine and human primary enamel than human permanent enamel, with some differences between S and DE. The XRD analysis showed that TiF4 induced the formation of new compounds such as CaF2, TiO2, and Ti(HPO4)2·H2O. In conclusion, TiF4 (>0.95% F) interacts better, when compared to NaF, with bovine and human primary enamel than with human permanent enamel. TiF4 provoked higher F deposition compared to NaF. Carious enamel showed higher F uptake than sound enamel by TiF4 application, while Ti uptake was dependent on the enamel condition and origin.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

Sign in / Sign up

Export Citation Format

Share Document