scholarly journals Approach to the knowledge of preservation of pleistocenic bone: The case of a Gomphothere cranium from the site of Tepeticpac, Tlaxcala, Mexico

2019 ◽  
Vol 36 (2) ◽  
pp. 170-182
Author(s):  
Luisa Straulino ◽  
Luisa Mainou ◽  
Teresa Pi ◽  
Sergey Sedov ◽  
Aurelio López-Corral ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive Spectroscopy ◽  
Crystallinity Index ◽  
X Ray Diffraction ◽  
Volcanic Origin ◽  
X Ray ◽  
Cell Parameters ◽  
Scanning Electron ◽  
Microbial Attack

An almost complete cranium of a gomphoterium found in Tepeticpac, Tlaxcala, was analyzed with X-ray diffraction (XRD), Petrography and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) to stablish the transformations of the bone during its burial. The analyses assessed that the bone mineral (bioapatite) had suffered modifications in mineral composition, “crystallinity index”, cell parameters and CO2 content. However, the paleohistological structure of the bone was not significantly affected, although evidence of microbial attack was found in the bone surfaces. The filling minerals of bone macro and micro porosity were also analyzed; its main filling minerals are calcite (micrite and sparite), clays, and minerals of volcanic origin.

Preparation of Pd /α–Al2O3 and Pd-Ag/α–Al2O3 Membranes by Electroless Plating and Permeation Measurements

2012 ◽  
Vol 1372 ◽  
Author(s):  
L. Ortiz-Martínez ◽  
M. Torres-Rodríguez ◽  
M. Gutiérrez-Arzaluz
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electroless Plating ◽  
Energy Dispersive Spectroscopy ◽  
Ceramic Composite ◽  
Composite Membranes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Α Al2o3 ◽  
Scanning Electron

ABSTRACTIn this work, the synthesis of dense Pd/α–Al2O3 and Pd-Ag/α–Al2O3 ceramic composite membranes was done through the sequential electroless plating technique of Pd and Ag. The precursors are solutions of PdCl2 and AgNO3 and N2H4 salts, as reducing agent. The membranes were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive Spectroscopy (EDS). The permeation tests of H2 and N2 was carried out at 20 psi of pressure and at 25°C, resulted πH2=5.2x10-9 mol H2/m2·s·Pa and πN2=8.2x10-10 mol N2/m2·s·Pa.

scholarly journals Microstructure of Dental Amalgams Containing High and Low Copper Contents

1977 ◽  
Vol 56 (12) ◽  
pp. 1481-1487 ◽  
Author(s):  
Manohar L. Malhotra ◽  
Kamal Asgar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
20Th Century ◽  
Energy Dispersive Spectroscopy ◽  
Optical Metallography ◽  
Dental Alloys ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dental Amalgams ◽  
Scanning Electron

Microstructure of commercial dental alloys and their amalgams were studied primarily by x-ray diffraction, optical metallography, scanning electron microscopy, and x-ray energy dispersive spectroscopy. X-ray diffraction revealed more phases than normally reported in these materials. Presence of new phases was discussed and their formation mechanism understood. Some phases having interacting 2θ° values with others were properly identified. Both new and conventional dental alloys and their amalgams, namely Tytin, Sybraloy, Dispersalloy, Kerr Spheraloy, Caulk Spherical, Shofu Spherical, and Caulk 20th Century Microcut were used to complete the investigation.

Study on the Mechanism of Magnesium Sulfate to Cement and C-S-H Gel

2011 ◽  
Vol 243-249 ◽  
pp. 4687-4690 ◽  
Author(s):  
Xiu Juan Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Magnesium Sulfate ◽  
Energy Dispersive Spectroscopy ◽  
Concrete Strength ◽  
Energy Dispersive ◽  
Test Block ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The microstructure of cement test block and the C-S-H gel attacked by magnesium sulfate is observed by means of scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS)and X-ray diffraction(XRD).It is found that the presence of Mg2+ makes C-S-H gel decalcify, dissolve and decompose, which thereby increasing the erosion of SO42- on the concrete. The decomposition of C-S-H and the generation of M-S-H result in the loss of concrete strength and the ultimate destruction of concrete.

ELECTROLESS DEPOSITION OF Ni-P ALLOYS ON CENOSPHERES BY USING SILVER AS THE CATALYST

2006 ◽  
Vol 20 (12) ◽  
pp. 715-723
Author(s):  
JIAN XU ◽  
WEIHAO XIONG ◽  
AIXIANG ZENG
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive Spectroscopy ◽  
Electroless Deposition ◽  
Coating Process ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
X Ray ◽  
Electroless Ni ◽  
Scanning Electron

Electroless deposition of Ni-P alloys on cenospheres is demonstrated in the present investigation. AgNO 3 is used as an activator to replace the conventional PdCl 2 activator and [Formula: see text] in the coating bath is used as the reducing agent to replace Sn 2+ in order to lower the overall cost of the coating process. The coated cenospheres are characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and powder X-ray diffraction (XRD). It shows that Ni-P alloys uniformly deposit on the surface of the cenospheres under experimental conditions. The possible mechanism of electroless Ni-P alloys coating of cenospheres by using silver as the catalyst is suggested.

Electroplated NiCo Alloy with Low Residual Stress from the Sulfate Bath

2020 ◽  
Vol 12 (4) ◽  
pp. 609-612
Author(s):  
Yong-Su Lee ◽  
Jae-Ho Lee
Keyword(s):  
Electron Microscopy ◽  
Residual Stress ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive Spectroscopy ◽  
Surface Hardness ◽  
X Ray Diffraction ◽  
Cobalt Sulfate ◽  
X Ray ◽  
Sulfate Bath ◽  
Scanning Electron

NiCo alloys are electroplated in sulfate bath. The concentration of cobalt sulfate and current density were varied to optimize the surface hardness. The properties of NiCo deposits were analyzed using field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The surface hardness of the NiCo alloy was increased up to 500 Hv at 24 wt% Co in the deposits due to the grain refinement. The size of grain was reduced to 12 nm. The residual stress of the deposits was varied from tensile to compressive as the saccharin concentration increased. The zero residual stress was achieved at 0.05 g/L saccharin addition.

scholarly journals EFECTS OF CHEMICAL COMPOSITION ON THE MICROSTRUCTURE AND PROPERTIES OF THE CU-Ge-Sb ALLOYS

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Dejan Gurešić ◽  
Aleksandar Đorđević ◽  
Aleksandar Marković ◽  
Milica Tomović ◽  
Nadežda Talijan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Scanning Electron Microscopy ◽  
Chemical Composition ◽  
Diffraction Analysis ◽  
Eddy Current ◽  
Energy Dispersive Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

In the current study a ternary Cu-Ge-Sb system has been experimentally assessed. Chemical andphase compositions of the alloy samples from three vertical sections Cu-GeSb, Ge-CuSb and Sb-CuGe were studied using scanning electron microscopy (SEM) and energy dispersive spectroscopy(EDS) and confirmed by X-ray diffraction analysis (XRD). Hardness of the alloys was measured byBrinell method while hardness of phases was measured using micro Vickers method. Electricalconductivity of the studied alloys was measured using eddy current instrument. Based onexperimentally determined values iso-lines of hardness and electrical conductivity for the wholeternary system were calculated using assumed mathematical models.

Carbothermal reduction of low-grade pyrolusite by microwave heating

RSC Advances ◽  
2014 ◽  
Vol 4 (102) ◽  
pp. 58164-58170 ◽  
Author(s):  
Qianxu Ye ◽  
Hongbo Zhu ◽  
Libo Zhang ◽  
Peng Liu ◽  
Guo Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Crystal Structures ◽  
Microwave Heating ◽  
Energy Dispersive Spectroscopy ◽  
Carbothermal Reduction ◽  
Low Grade ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Pyrolusite was carbothermally reduced using coal by microwave heating, and the crystal structures and microstructures of the samples were characterized after microwave heating using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS).

scholarly journals Investigation of metals content in the fine fraction of municipal waste from Alytus Regional Landfill

Chemija ◽  
2019 ◽  
Vol 30 (3) ◽  
Author(s):  
Rugilė Kemeklytė ◽  
Algimantas Bučinskas ◽  
Gintaras Denafas
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive Spectroscopy ◽  
Chemical Elements ◽  
Fine Fraction ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

This study presents the results of investigation of the fine waste fraction from the Alytus Regional Landfill. The fine fraction was analysed with the aim of characterization of the chemical elements content using scanning electron microscopy, coupled with energy-dispersive spectroscopy (EDS), SEM and X-ray diffraction (XRD) analysis. Quartz SiO2, calcite CaCO3, anhydrite CaSO4, albite NaAlSi3O8, dolomite CaMg(CO3)2, microcline KAlSi3O8, periclase MgO and muscovite KNa(Al, Mg, Fe)2(Si3.1, Al0.9)O10(OH)2 minerals were identified. The quantity of C, O, Na, Mg, Al, Si, K, Ca, Fe, P, S, Cl and Ti chemical elements was determined and their percentage change after heating was calculated.

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