Elemental Analysis of Alkalis and Dental Deposits Associated with Coca Chewing in Ecuador

2006 ◽  
Vol 17 (1) ◽  
pp. 77-89 ◽  
Author(s):  
Douglas H. Ubelaker ◽  
Karen E. Stothert
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Spectral Analysis ◽  
North America ◽  
Elemental Analysis ◽  
X Ray ◽  
Tooth Structure ◽  
Elemental Analyses ◽  
The Relationship ◽  
Scanning Electron

AbstractThe relationship between Andean coca use and dental deposits is explored through the use of scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Elemental analyses of samples of large dental deposits from archeologically recovered skeletons from Ecuador dating between 500 B.C. and A.D. 1532 are compared with those of normal calculus deposits of individuals from North America (modern and precontact), of normal tooth structure and of samples of alkali recovered from Ecuadorian artifacts thought to have been employed in coca use. Spectral analysis revealed homogeneity among all dental samples (deposits and structure) and that they are distinct from the elemental pattern revealed in the analysis of the artifact alkalis.

X-RAY Microanalysis of Selected Coelenterate Statoliths

1985 ◽  
Vol 65 (3) ◽  
pp. 617-627 ◽  
Author(s):  
David M. Chapman
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Atomic Number ◽  
Elemental Analysis ◽  
Energy Dispersive Spectrometer ◽  
X Ray ◽  
Relationship Of ◽  
Micro Analysis ◽  
The Relationship ◽  
Scanning Electron

When scanning electron microscopy became integrated with X-ray micro-analysis, it became an easy matter to localize an object and perform a semi-quantitative elemental analysis of atoms of atomic number 11 or higher using an energy dispersive spectrometer. This technique is used in the present study to determine the chemistry of the statoliths of eight hydromedusae, two scyphomedusae, one cubozoan and a ctenophore with respect to their comparative biomineralization and the relationship of the mineral to their taxonomy.

New coordination polymers of glyoxal bis(2-hydroxyanil)

1995 ◽  
Vol 7 (4) ◽  
pp. 433-441 ◽  
Author(s):  
Salah A EI-Shatoury
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Metal Ions ◽  
Coordination Polymers ◽  
Elemental Analysis ◽  
Electronic Spectra ◽  
Metal Content ◽  
X Ray ◽  
Dsc Analyses ◽  
Scanning Electron

Coordination polymers of [2,2'-(ethandiylidenedinitrilo) diphenol) have been prepared with the metal ions Cu(II), Ni(1I) and Cr(III). They were characterized by elemental analysis, IR and electronic spectra. The metal content in all polymers was found to be consistent with a 1:1 (metal:ligand) stoichiometry. The thermal behaviour of these coordination polymers has been studied by thermogravimetric and DSC analyses in air up to 500 C. The crystallinity of the formed polymers was determined by x-ray analysis. The morphological structures of these polymers were determined by scanning electron microscopy.

Microstructure and Properties of CBN Diffusion Coating on High-Speed Steel

2011 ◽  
Vol 312-315 ◽  
pp. 542-547 ◽  
Author(s):  
Alexander S. Chaus ◽  
Lubomír Čaplovič ◽  
Ján Porubský
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tool Life ◽  
High Speed ◽  
Diffusion Coating ◽  
High Speed Steel ◽  
X Ray ◽  
End Mills ◽  
The Relationship ◽  
Scanning Electron

CBN diffusion coating on the ball nose end mills made of AISI-M35 high speed steel (HSS) has been produced thermo-chemically. The microstructure and component depth profiles of the CBN diffusion layer have been studied by scanning electron microscopy and energy dispersive X-ray spectrometry. The results on laboratory cutting tests of ball nose end mills made of AISI-M35 HSS with and without complex CBN diffusion coating are also introduced in the paper. The relationship between wear kinetics and tool life has been established. It was shown that under the used cutting conditions the tool life of the mills with the coating was a factor of 1.6 higher than that of the mills without the coating. The higher tribological stability of the coating in cutting process was supported by metallographic observations of the worn surfaces using scanning electron microscopy.

scholarly journals Could night-guards be used as a simple method to detect leached-elements from dental restorations intra-orally? A study on amalgam restorations

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1786
Author(s):  
Rasha Mohamed Abdelraouf
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Elemental Analysis ◽  
Dental Amalgam ◽  
Simple Method ◽  
X Ray ◽  
Dental Restorations ◽  
Custom Made ◽  
Amalgam Restorations ◽  
Scanning Electron

Background: Detection of leached-elements from dental restorations intra-orally has been a subject of prime importance in dental research. However, this is challenging as most of the present techniques have some limitations. In this study, a new simple method was proposed via using night-guards. Thus, the aim of the study was to verify if night-guards could detect leached-elements from restorations as dental amalgam. Methods: Ten upper custom-made night-guards were fabricated for patients suffering from bruxism, who had amalgam-restorations in their upper molars. The night-guards were delivered to the patients and they were instructed to wear the night-guards during when they were asleep. After six months, the night-guards were taken from the patients to be analyzed. A new unused night-guard was fabricated from the same material to be used as a control. In the used night-guards, two areas were studied: the fitting surfaces contacting the amalgam restorations and the fitting surfaces not contacting amalgam restorations. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Analysis (EDXA) were used to examine the structural and elemental changes in the night-guards.   Results: SEM of the unused night-guard revealed a homogenous structure, and the composition was carbon and oxygen, as shown using EDXA (C=88.9wt% and O=11.1wt%). By contrast, the fitting surfaces of the night-guards contacting amalgam restorations showed numerous lustrous particles. Elemental analysis of these areas showed the presence of mercury and sulfur, in addition to carbon and oxygen (Hg=21.2wt%, S=2.5wt%, C=67.1wt% and O=9.2wt%). The night-guards’ fitting surfaces not contacting amalgam restorations showed slight cracking, and the composition was carbon and oxygen (C=88.3wt% and O=11.7 wt%).  Conclusions: Analyzing fitting surfaces of night-guards contacting dental restorations, such as amalgam, could aid in understanding the nature of leached-elements from these restorations intra-orally. However, further studies about its application upon dental-restorations other than amalgam are recommended.

scholarly journals Dielectric Studies of Nano Structured BaTi1-XSnxO3 Solid Solutions

2014 ◽  
Vol 32 ◽  
pp. 191-201
Author(s):  
Hema Chandra Rao Bitra ◽  
B.B.V.S. Vara Prasad
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ball Milling ◽  
Solid Solutions ◽  
Energy Dispersive Spectroscopy ◽  
Dielectric Studies ◽  
Dielectric Measurements ◽  
X Ray ◽  
Elemental Analyses ◽  
Scanning Electron

BaTi1-xSnxO3 (BTSx) ceramics had been prepared by temperature sintering technique. Initially, the samples were calcined at a temperature at 900 °C for 2 hours, after that ball milling was done and then the samples were sintered at a temperature of 1150 °C for 3 hours. X-ray diffractometry, Scanning Electron Microscopy, Energy Dispersive Spectroscopy and Dielectric measurements were carried out and structural, micro structural and elemental analyses were discussed in brief

Structure and properties of modified gypsum binder

2020 ◽  
Vol 10 (4) ◽  
pp. 702-710
Author(s):  
G.I. Yakovlev ◽  
A. Gordina ◽  
Rostislav Drochytka ◽  
A.F. Buryanov ◽  
Olga Smirnova
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Spectral Analysis ◽  
Structural Modification ◽  
Content Type ◽  
X Ray ◽  
Calcium Sulfate Dihydrate ◽  
Carbon Soot ◽  
Scanning Electron ◽  
Crystalline Hydrates

PurposeThe purpose of the study is regarding the development of eco-oriented technologies for obtaining the building gypsum materials with the involvement of industrial by-products or waste.Design/methodology/approachThe scanning electron microscopy, X-ray microanalysis and IR spectral analysis were used to study the structure of gypsum matrix. The method of comparison of modified and unmodified gypsum matrix was used. Physical modeling of gypsum matrix crystallization is used to study changes in the morphology of hydration products.FindingsThe experimental results show that the addition of technical soot into a gypsum binder leads to a change in the morphology of crystalline hydrates of calcium sulfate dihydrate. Results of the scanning electron microscopy, X-ray microanalysis and IR spectral analysis confirm the change of physical and mechanical characteristics of the gypsum binder due to the structural modification of the gypsum matrix with ultrafine carbon soot. The achieved degree of the structural modification of the gypsum matrix is compatible with the results obtained when the gypsum binder was modified with dispersions of carbon nanotubes.Originality/valueThe morphology of the crystalline hydrates of the gypsum matrix with the addition of 0.04%, 0.06% and 1% of the carbon soot is characterized by the transition of the classical needle-like structure of gypsum dihydrate to the lamellar structure of increased density. One can observe the formation of intergrowths around ultrafine carbon soot particles. The studied carbon additive can improve strength characteristics of the gypsum matrix.

Effect of Silk Reeling Velocity on the Aggregation Structure of Raw Silk

2011 ◽  
Vol 175-176 ◽  
pp. 496-499
Author(s):  
Li Na Li ◽  
Shi Qi Bai ◽  
Ya Qin Fu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Sonic Velocity ◽  
X Ray Diffraction ◽  
Orientation Degree ◽  
X Ray ◽  
Aggregation Structure ◽  
The Relationship ◽  
Scanning Electron

The aggregation structure of raw silk which influences the mechanical properties of raw silk directly is not only determined by the properties of cocoon but also affected by silk reeling velocity. In this study, the relationship between aggregation structure of raw silk and silk reeling velocity was studied by means of sonic velocity method, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The study showed that orientation degree, crystallinity and mechanical properties of raw silk were remarkably influenced by silk reeling velocity, and the mechanical properties of raw silk would be improved through the reasonable silk reeling velocity.

Formation of intermetallic compounds during the sintering of zirconium–iron powders compact

1988 ◽  
Vol 3 (2) ◽  
pp. 219-225
Author(s):  
M. M. Stupel ◽  
B. Z. Weiss ◽  
M. Bamberger
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Room Temperature ◽  
Intermediate Phase ◽  
Sintering Process ◽  
Iron Powders ◽  
X Ray ◽  
Sintering Time ◽  
The Relationship ◽  
Scanning Electron

The sintering process at 840°C and at 925°C, of Zr-7.2 wt. % Fe was studied by room-temperature Mössbauer spectroscopy, x-ray diffractometry, and scanning electron microscopy. According to phase analysis, most of the αFe phase disappeared after 20 h of sintering at 840°C and after 4 h at 925°C. During the sintering, small quantities of the intermetallic compound ZrFe2 as an intermediate phase were observed clearly by the Mössbauer technique and very weakly by x-ray diffractometry. The relationship among the relative quantities of αFe, ZrFe2, and Zr3Fe phases was determined. The change in density as a function of sintering time was measured, and the results were explained on the basis of the different sintering stages and phase transformations.

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