Crack Healing in an Alumina/Silicon Carbide Nanocomposite After Grinding and Annealing

1999 ◽  
Vol 581 ◽  
Author(s):  
H.Z. Wu ◽  
J.M. Titchmarsh ◽  
S.G. Roberts ◽  
B. Derby
Keyword(s):  
Silicon Carbide ◽  
Chemical Composition ◽  
Cross Sections ◽  
Surface Crack ◽  
Annealing Process ◽  
Energy Dispersive ◽  
Polished Surface ◽  
Crack Healing ◽  
X Ray ◽  
Small Improvement

ABSTRACTAlumina/silicon carbide nanocomposites are known to show their highest strength levels after surface grinding followed by annealing. After annealing in flowing argon, nanocomposites with very coarsely ground surfaces have strengths exceeding those with a finely polished surface. Specimens with lapped surfaces also show a small improvement in strength on annealing. TEM investigations of annealed cross-sections show that the annealing process leads to surface crack healing. The chemical composition of the subsurface region has been studied, and reactive products on and close to the nanocomposite surface after annealing have been investigated by energy dispersive X-ray analysis in the STEM.

Preparation And elemental analysis of ancient fibers

1987 ◽  
Vol 45 ◽  
pp. 410-411
Author(s):  
Allen Angel ◽  
Kathryn A. Jakes
Keyword(s):  
Cross Sections ◽  
Physical Structure ◽  
Energy Dispersive ◽  
Archaeological Sites ◽  
X Ray ◽  
Long Term Storage ◽  
Backscattered Electron ◽  
Electron Imaging

Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.

Field-Emission Scanning Electron Microscopy and Energy-Dispersive X-Ray Analysis to Understand the Role of Tannin-Based Dyes in the Degradation of Historical Wool Textiles

2014 ◽  
Vol 20 (5) ◽  
pp. 1534-1543 ◽  
Author(s):  
Annalaura Restivo ◽  
Ilaria Degano ◽  
Erika Ribechini ◽  
Josefina Pérez-Arantegui ◽  
Maria Perla Colombini
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Elemental Composition ◽  
Field Emission ◽  
Cross Sections ◽  
Morphological Changes ◽  
Energy Dispersive ◽  
X Ray ◽  
Edx Analysis ◽  
Scanning Electron

Abstract:An innovative approach, combining field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy (EDX) analysis, is presented to investigate the degradation mechanisms affecting tannin-dyed wool. In fact, tannin-dyed textiles are more sensitive to degradation then those dyed with other dyestuffs, even in the same conservation conditions.FESEM-EDX was first used to study a set of 48 wool specimens (artificially aged) dyed with several raw materials and mordants, and prepared according to historical dyeing recipes. EDX analysis was performed on the surface of wool threads and on their cross-sections. In addition, in order to validate the model formulated by the analysis of reference materials, several samples collected from historical and archaeological textiles were subjected to FESEM-EDX analysis.FESEM-EDX investigations enabled us to reveal the correlation between elemental composition and morphological changes. In addition, aging processes were clarified by studying changes in the elemental composition of wool from the protective cuticle to the fiber core in cross-sections. Morphological and elemental analysis of wool specimens and of archaeological and historical textiles showed that the presence of tannins increases wool damage, primarily by causing a sulfur decrease and fiber oxidation.

Morphology and Chemical Composition of Silicon Carbide Surfaces Interacting with Iron, Cobalt, and Nickel in Microscratching

2018 ◽  
Vol 284 ◽  
pp. 363-368 ◽  
Author(s):  
V.A. Nosenko ◽  
A.V. Fetisov ◽  
V.Ye. Puzyrkova
Keyword(s):  
Silicon Carbide ◽  
Electron Microscope ◽  
Chemical Composition ◽  
Iron Cobalt ◽  
Beam Electron ◽  
X Ray ◽  
Metal Atoms ◽  
Dual Beam ◽  
Structure Of Metal ◽  
Cobalt And Nickel

The paper dwells upon the specifics of worn spots being formed on a silicon-carbide crystal in microscratching of iron, cobalt, and nickel. Analysis was done using a Versa 3D dual-beam electron microscope. The chemical composition of worn spots was studied by local X-ray microanalysis. It was found out that the amount of metal transferred to the silicon-carbide worn spot was associated with the electron structure of metal atoms.

Design of 2D-nanocrystals in water: preparation, structure and functionalization

2018 ◽  
Vol 90 (5) ◽  
pp. 833-844
Author(s):  
Leonid Aslanov ◽  
Valery Zakharov ◽  
Ksenia Paseshnichenko ◽  
Aleksandr Yatsenko ◽  
Andrey Orekhov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Composition ◽  
High Resolution ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Room Temperature ◽  
Energy Dispersive ◽  
X Ray ◽  
Transmission Electron

AbstractA new method for synthesis of 2D nanocrystals in water was proposed. The use of perfluorothiophenolate ions as surfactant allowed us to produce 2D single-crystal nanosheets of CaS at pH=9 and flat nanocrystals of PbS at pH=9 at room temperature. Mesocrystalline nanobelts of CdS and mesocrystals of PbS were obtained at pH=3–5 and pH=10–12, respectively. Morphology, structure and chemical composition of nanoparticles were characterized by high-resolution transmission electron microscopy, electron diffraction and energy dispersive X-ray spectroscopy. A mechanism of nanoparticles formation was discussed.

scholarly journals Analysis of the Mixing of Filler and Base Materials in Arc-Welded Single-Bead Surface Welds Using an EDXS Method

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 217
Author(s):  
Borut Zorc ◽  
Matija Zorc ◽  
Aleš Nagode
Keyword(s):  
Chemical Composition ◽  
Cross Sections ◽  
Steel Plate ◽  
Influencing Factor ◽  
Base Material ◽  
Arithmetic Means ◽  
X Ray ◽  
Base Materials ◽  
Bead Surface ◽  
Single Bead

This article deals with an analysis of mixing and determines the admixing rate of a base S355 steel plate in single-bead surface welds by measuring the chemical composition using a plane-scan energy dispersive X-ray spectroscopy (EDXS) on metallographic cross-sections. The results show that obtaining a larger number of EDXS measurements does not necessarily lead to obtaining a more accurate admixing rate. Due to the ever-present segregations that are generally near the base material, the disadvantage of this method is the subjective influence of the SEM operator on the estimated admixing rate. To obtain relevant results, a sufficiently wide area of well-mixed melt, including segregations, must be analyzed. This study showed that by using a sufficiently large number of appropriately selected sites with a sufficiently large surface area, it is possible to estimate the admixing rate from the chemical composition with an accuracy of ≥96% for the geometrically determined admixing rate D = 30%. From several equations, the best result showed an equation which is the arithmetic mean of the two different arithmetic means and in which the artificial influencing factor of the segregations of the base material is taken into account. With this equation, the same value of admixing rate, D = 30%, was obtained using the comparative geometric method.

scholarly journals Chemical parameters of gourmet salts compared withsalt extracted from eichhornia crassipes evaluated by energy-dispersive x-ray spectrometry

2020 ◽  
Vol 42 ◽  
pp. e51
Author(s):  
Paulo Afonso Rossignoli ◽  
Frederico Fonseca da Silva ◽  
Wilson Sacchi Peternella
Keyword(s):  
Chemical Composition ◽  
Dry Matter ◽  
Eichhornia Crassipes ◽  
Aquatic Macrophyte ◽  
Energy Dispersive ◽  
Chemical Parameters ◽  
High Concentration ◽  
Daily Consumption ◽  
Food Markets ◽  
X Ray

Salts have been part of human nutrition since 2,000 b.C., having originated in the Zhongba region, in China. Itssubstantial availability in food markets and stores specialized in condiments led us, curiously, to compare its elemental chemical composition with that of salt extracted from a floating aquatic macrophyte, known commonly as “water hyacinth” (Eichhornia crassipes), whose product, after extraction from dry matter, was popularly denominated“indigenous salt”. The objective of the present study was to evaluate the chemical composition of gourmet salts in comparison with indigenous salt using the energy-dispersive X-ray spectrometry (EDX) technique. Eichhornia crassipes exhibited higher concentrations of chloride (35.834%), potassium (62.146%), sulfur (1.095%), calcium (0.450%), bromine (0.177%), silicon (0.124%), copper (0.029%), magnesium (0.123%), and rubidium (0.023%) than the gourmet salts. Our results indicate that this indigenous salt should be consumed under medical guidance due to its high concentration of potassium chloride, a salt whose properties are used for specific human treatment and not daily consumption.

scholarly journals Investigating the interstellar dust through the Fe K-edge

2017 ◽  
Vol 609 ◽  
pp. A22 ◽  
Author(s):  
D. Rogantini ◽  
E. Costantini ◽  
S. T. Zeegers ◽  
C. P. de Vries ◽  
W. Bras ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Cross Sections ◽  
Interstellar Dust ◽  
Effective Area ◽  
European Synchrotron Radiation Facility ◽  
Galactic Centre ◽  
X Rays ◽  
X Ray ◽  
Wide Range ◽  
The Individual

Context. The chemical and physical properties of interstellar dust in the densest regions of the Galaxy are still not well understood. X-rays provide a powerful probe since they can penetrate gas and dust over a wide range of column densities (up to 1024 cm-2). The interaction (scattering and absorption) with the medium imprints spectral signatures that reflect the individual atoms which constitute the gas, molecule, or solid. Aims. In this work we investigate the ability of high resolution X-ray spectroscopy to probe the properties of cosmic grains containing iron. Although iron is heavily depleted into interstellar dust, the nature of the Fe-bearing grains is still largely uncertain. Methods. In our analysis we use iron K-edge synchrotron data of minerals likely present in the ISM dust taken at the European Synchrotron Radiation Facility. We explore the prospects of determining the chemical composition and the size of astrophysical dust in the Galactic centre and in molecular clouds with future X-ray missions. The energy resolution and the effective area of the present X-ray telescopes are not sufficient to detect and study the Fe K-edge, even for bright X-ray sources. Results. From the analysis of the extinction cross sections of our dust models implemented in the spectral fitting program SPEX, the Fe K-edge is promising for investigating both the chemistry and the size distribution of the interstellar dust. We find that the chemical composition regulates the X-ray absorption fine structures in the post edge region, whereas the scattering feature in the pre-edge is sensitive to the mean grain size. Finally, we note that the Fe K-edge is insensitive to other dust properties, such as the porosity and the geometry of the dust.

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