In Situ X-Ray Tomography Densification of Firn: Decoupling the Role of Mechanics and Diffusion Processes

2018 ◽  
Author(s):  
Alexis Burr ◽  
Pierre Lhuissier ◽  
Christophe L. Martin ◽  
Armelle Philip
2019 ◽  
Vol 167 ◽  
pp. 210-220 ◽  
Author(s):  
Alexis Burr ◽  
Pierre Lhuissier ◽  
Christophe L. Martin ◽  
Armelle Philip

2020 ◽  
pp. 130-135
Author(s):  
D.N. Korotaev ◽  
K.N. Poleshchenko ◽  
E.N. Eremin ◽  
E.E. Tarasov

The wear resistance and wear characteristics of cluster-gradient architecture (CGA) nanostructured topocomposites are studied. The specifics of tribocontact interaction under microcutting conditions is considered. The reasons for retention of high wear resistance of this class of nanostructured topocomposites are studied. The mechanisms of energy dissipation from the tribocontact zone, due to the nanogeometry and the structural-phase structure of CGA topocomposites are analyzed. The role of triboactivated deformation and diffusion processes in providing increased wear resistance of carbide-based topocomposites is shown. They are tested under the conditions of blade processing of heat-resistant titanium alloy.


1999 ◽  
Vol 567 ◽  
Author(s):  
Masayuki Suzuki ◽  
Yoji Saito

ABSTRACTWe tried direct oxynitridation of silicon surfaces by remote-plasma-exited nitrogen and oxygen gaseous mixtures at 700°C in a high vacuum. The oxynitrided surfaces were investigated with in-situ X-ray photoelectron spectroscopy. With increase of the oxynitridation time, the surface density of nitrogen gradually increases, but that of oxygen shows nearly saturation behavior after the rapid increase in the initial stage. We also annealed the grown oxynitride and oxide films to investigate the role of the contained nitrogen. The desorption rate of oxygen from the oxynitride films is much less than that from oxide films. We confirmed that nitrogen stabilizes the thermal stability of these oxynitride films.


2015 ◽  
Vol 17 (15) ◽  
pp. 9841-9848 ◽  
Author(s):  
Moheb Nayeri ◽  
Kim Nygård ◽  
Maths Karlsson ◽  
Manuel Maréchal ◽  
Manfred Burghammer ◽  
...  

Structural and chemical changes during the sol–gel synthesis of silica using an ionic liquid are investigatedin situand simultaneously by X-ray scattering and μ-Raman spectroscopy.


2010 ◽  
Vol 12 (20) ◽  
pp. 5307 ◽  
Author(s):  
Cecilia Mondelli ◽  
Jan-Dierk Grunwaldt ◽  
Davide Ferri ◽  
Alfons Baiker

2010 ◽  
Vol 72 ◽  
pp. 164-169 ◽  
Author(s):  
Daphiny Pottmaier ◽  
Sebastiano Garroni ◽  
Maria Dolors Barò ◽  
Marcello Baricco

Hydrogen storage in the solid state has shown increasing research and development, and recently an approach in mixing two hydride systems together by ball milling (reactive hydride composites) has been investigated in more detail, e.g. NaBH4 plus MgH2. Thermodynamic destabilization may occur by new compounds formation during dehydrogenation, e.g. MgB2. A study of the the role of O2/H2O contamination for the reaction 2NaBH4 + MgH2 ↔ 2NaH + MgB2 + 4H2 was conducted using in-situ X-ray powder diffraction. Desorption reaction is observed to begin by a competition of MgH2 and NaBH4 decomposition due to higher reactivity promoted by ball milling processing summed to O2/H2O contamination. Oxidation of NaBH4 into NaBO2 is observed to happen in higher degree than MgH2/Mg into MgO for the Na-Mg-B-H system.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ravi raj purohit Purushottam raj purohit ◽  
Abhinav Arya ◽  
Girish Bojjawar ◽  
Maxime Pelerin ◽  
Steven Van Petegem ◽  
...  

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