In-Situ Ablation Experiments of Cork-based and Carbon Phenolic Thermal Protection Materials in an X-Ray Synchrotron Facility

2018 ◽  
Author(s):  
Isil Sakraker ◽  
Archana Joshi ◽  
Hannah Böhrk ◽  
Daniel Haenschke ◽  
Angelica Cecilia
Keyword(s):  
Thermal Protection ◽  
X Ray ◽  
Synchrotron Facility

scholarly journals Micro-XRF study of the troodontid dinosaur Jianianhualong tengi reveals new biological and taphonomical signals

2020 ◽  
Author(s):  
Jinhua Li ◽  
Rui Pei ◽  
Fangfang Teng ◽  
Hao Qiu ◽  
Roald Tagle ◽  
...  
Keyword(s):  
Small Samples ◽  
Elemental Distribution ◽  
Large Area ◽  
X Ray ◽  
Xrf Analysis ◽  
Synchrotron Facility ◽  
Practical Tool ◽  
Synchrotron Imaging ◽  
Taphonomic Processes

AbstractJianianhualong tengi is a key taxon for understanding the evolution of pennaceous feathers as well as troodontid theropods, and it is known by only the holotype, which was recovered from the Lower Cretaceous Yixian Formation of western Liaoning, China. Here, we carried out a large-area micro-X-Ray fluorescence (micro-XRF) analysis on the holotypic specimen of Jianianhualong tengi via a Brucker M6 Jetstream mobile XRF scanner. The elemental distribution measurements of the specimen show an enrichment of typical bones couponing elements such as S, P and Ca allowing to visualize the fossil structure. Additionally, to this, the bones are enriched in several heavier elements such as Sr, Th, Y and Ce over the surrounding rocks. The enrichment is most likely associated to secondary mineralization and the phosphates from the bones. Interestingly the plumage shape correlates with an enrichment in elements such as Cu, Ni and Ti, consistent with a previous study [1] on Archaeopteryx using synchrotron imaging. The analysis presented here provide new biological and taphonomic information of this fossil. An in-situ and nondestructive micro-XRF analysis is currently the most ideal way to map the chemistry of fossils, so far this is manly restricted to small samples. Larger samples usually required a synchrotron facility for analysis. Our study demonstrated that laboratory-based large-area micro-XRF scanner can provides a practical tool for the study of large large-sized specimens allowing collect full chemical data for a better understanding of evolutionary and taphonomic processes.

In situ Investigation during Low Pressure Carburizing by Means of Synchrotron X-ray Diffraction*

2021 ◽  
Vol 76 (6) ◽  
pp. 417-431
Author(s):  
O. B. Tapar ◽  
M. Steinbacher ◽  
J. Gibmeier ◽  
N. Schell ◽  
J. Epp
Keyword(s):  
Low Pressure ◽  
X Ray Diffraction ◽  
Electron Synchrotron ◽  
Carbon Profile ◽  
X Ray ◽  
Direct Contribution ◽  
Synchrotron Facility ◽  
In Situ Investigation ◽  
Low Levels

Abstract In situ X-ray diffraction investigations during low pressure carburizing (LPC) processes were performed with a specially developed process chamber at the German Electron Synchrotron Facility (DESY) in Hamburg, Germany. Carbon saturation in austenite was reached in less than 20 seconds for all processes with different parameters and carbides formed at the surface. Therefore, the direct contribution of carbon donor gas to the carbon profile after 20 seconds was reduced to very low levels. After that point, further supply of carbon donor gas increased the amount of carbides formed at the surface, which will contribute to the carbon profile indirectly by dissolution in the following diffusion steps. During quenching, martensite at higher temperatures had a lower c/a ratio than later formed ones. This difference is credited to self-tempering effects and reordering of carbon atoms within the martensite lattice.

Crystallographic Analysis of Cvd Films by Using X-Ray Polychromatic Radiation

1998 ◽  
Vol 524 ◽  
Author(s):  
B. Lavelle ◽  
L. Brissonneau ◽  
E. Baggot ◽  
C. Vahlas
Keyword(s):  
Reference Sample ◽  
Chemical Vapor ◽  
Crystallographic Analysis ◽  
Bragg Angle ◽  
X Ray Diffraction ◽  
Solid State Detector ◽  
X Ray ◽  
Synchrotron Facility

ABSTRACTThe Energy Dispersive X-ray Diffiractometry (EDXD) technique was tested for in-situ crystallographic characterization of nickel films processed by chemical vapor deposition (CVD). The diffracted beam at low Bragg angle was analyzed in energy by a solid state detector. A nickel reference sample was used to face the problems of EDXD background signal and uncertainty of sample location. The relative accuracy on lattice parameters measurements is 1.5.10−3, to be compared to 0.5.10−3 for classical (monochromatic) X-Ray diffraction. Texture measurements yields results in agreement with those obtained from recent texture goniometer. Finally, an estimation of the thickness was obtained from the intensity of nickel fluorescence peak. In view of the obtained results, EDXD appears to be a promising technique for in-situ studies. Although less powerful compared to the synchrotron facility, it is more flexible and can be applied at lower cost.

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.

In Situ X-Ray Absorption Studies of the Electrochemical Reduction of Hydroxocobalamin

1997 ◽  
Vol 7 (C2) ◽  
pp. C2-619-C2-620 ◽  
Author(s):  
M. Giorgett ◽  
I. Ascone ◽  
M. Berrettoni ◽  
S. Zamponi ◽  
R. Marassi
Keyword(s):  
Electrochemical Reduction ◽  
X Ray ◽  
Absorption Studies ◽  
X Ray Absorption

A Revised O2 Reduction Model in Li-O2 Batteries as Revealed by in Situ Small Angle X-Ray Scattering

2019 ◽  
Author(s):  
Christian Prehal ◽  
Aleksej Samojlov ◽  
Manfred Nachtnebel ◽  
Manfred Kriechbaum ◽  
Heinz Amenitsch ◽  
...  
Keyword(s):  
Small Angle ◽  
Wide Angle ◽  
Reduction Mechanism ◽  
Reduction Model ◽  
X Ray ◽  
X Ray Scattering ◽  
O2 Reduction ◽  
Ray Scattering

<b>Here we use in situ small and wide angle X-ray scattering to elucidate unexpected mechanistic insights of the O2 reduction mechanism in Li-O2 batteries.<br></b>

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

Monitoring Polymer-Assisted Mechanochemical Cocrystallisation Through in Situ X-Ray Powder Diffraction

2020 ◽  
Author(s):  
Luzia S. Germann ◽  
Sebastian T. Emmerling ◽  
Manuel Wilke ◽  
Robert E. Dinnebier ◽  
Mariarosa Moneghini ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Powder Diffraction ◽  
Reaction Rate ◽  
Polymer Additives ◽  
Time Resolved ◽  
X Ray

Time-resolved mechanochemical cocrystallisation studies have so-far focused solely on neat and liquid-assisted grinding. Here, we report the monitoring of polymer-assisted grinding reactions using <i>in situ</i> X-ray powder diffraction, revealing that reaction rate is almost double compared to neat grinding and independent of the molecular weight and amount of used polymer additives.<br>

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