Preparation And elemental analysis of ancient fibers

Author(s):  
Allen Angel ◽  
Kathryn A. Jakes

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.

2004 ◽  
Vol 19 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Yury Teterin ◽  
Serguei Stefanovskij ◽  
Serguei Yudintsev ◽  
George Bek-Uzarov ◽  
Anton Teterin ◽  
...  

The synthesis of ceramic matrixes for the long-term storage of highly active radionuclide wastes and determination of physical and chemical forms of radionuclides in them is one of the important problems in radioecology. It enables to create purpose fully materials for the long-term storage of radionuclides. In the present work the samples of ceramics [CaCe0.9Ti2O6.8(I) and CaCeTi2O7(II}] formed under various conditions were investigated with the X-ray photo electron spectroscopy. It is necessary for synthesis of ceramic matrixes, for the disposal of the plutonium and others tetravalent actinides. A technique was developed for the determination of cerium oxidation state (Ce3+ and Ce4+) on the basis of the X-ray photo electron spectroscopy spectral structure characteristics. It was established that the sample (I) formed at 300 MPa and T = 1400 ?C in the air atmosphere contained on the surface two types of cerium ions in the ratio ? 63 atomic % of Ce3+ and 37 atomic % of Ce4+, and the sample (II) formed at 300 MPa and T= 1300 ?C in the oxygen atmosphere contained on its surface two types of cerium ions also, but in the ratio ? 36 atomic % of Ce3+ and 64 atomic % of Ce4+. It was established that on the surface of the studied ceramics carbonates of calcium and/or cerium could be formed under influence of the environment that leads to the destruction of ceramics.


Author(s):  
I. Noell ◽  
D. Morris

Proton microprobe and electron probe X-ray microanalysis (EPXMA) simultaneously measure and map elemental content, and hence are excellent tools for investigating the distribution and function of elevated Ni levels in hyperaccumulating plants (Ni concentration >1000 μg g−1 dry weight). Five major hypotheses have been proposed for the function of Ni hyperaccumulation. Our research focuses on the hypothesis that Ni defends against herbivore or pathogen attack and examines the movement of Ni from soil through plant to herbivore in Stackhousia tryonii, the only known hyperaccumulator in eastern Australia. Using a JEOL JXA-840-A electron probe microanalyzer with Moran Scientific Analysis software, we located features of high mean atomic number in whole leaves and cross-sections through backscattered-electron imaging (BEI), then we used EPXMA to identify the elements present and to prepare semi-quantitative x-ray maps of seven key elements.


1994 ◽  
Vol 353 ◽  
Author(s):  
P. Eberly ◽  
J. Janeczek ◽  
R. Ewing

AbstractThis paper describes the mineralogy of a phyllosilicate/uraninite/galena-bearing vein located within the hydrothermal alteration halo associated with the Bangombé reactor. Phyllosilicates within the vein include a trioctahedral Al-Mg-Fe chlorite (ripidolite), Al-rich clay (kaolinite and/or donbassite) and illite. Textural relations obtained by backscattered-electron imaging suggest that ripidolite crystallized first among the sheet silicates. Uraninite is spatially associated with ripidolite and probably precipitated at a later time. While energy-dispersive x-ray analyses suggest that the uranium phase is predominantly uraninite, coffinite or other phases may also be present.


2016 ◽  
Vol 22 (1) ◽  
pp. 71-81 ◽  
Author(s):  
Katherine E. MacArthur ◽  
Thomas J. A. Slater ◽  
Sarah J. Haigh ◽  
Dogan Ozkaya ◽  
Peter D. Nellist ◽  
...  

AbstractThe new generation of energy-dispersive X-ray (EDX) detectors with higher count rates than ever before, paves the way for a new approach to quantitative elemental analysis in the scanning transmission electron microscope. Here we demonstrate a method of calculating partial cross sections for use in quantifying EDX data, beneficial especially because of the simplicity of its implementation. Applying this approach to acid-leached PtCo catalyst nanoparticles leads to quantitative determination of the Pt surface enrichment.


2005 ◽  
Vol 39 (4) ◽  
pp. 391-394 ◽  
Author(s):  
Binbin Wang ◽  
John C. Jackson ◽  
Curtis Palmer ◽  
Baoshan Zheng ◽  
Robert B. Finkelman
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