Experimental Study of Effect of Temperature and Ultra-High Pressure on Coalification of Bituminous Coal

1966 ◽  
Vol 5 (3) ◽  
pp. 242-246 ◽  
Author(s):  
L.-S. Pan ◽  
T. N. Andersen ◽  
Henry Eyring
2016 ◽  
Vol 8 (3) ◽  
pp. 168781401663679 ◽  
Author(s):  
Can Kang ◽  
Haixia Liu ◽  
Xiuge Li ◽  
Ya Zhou ◽  
Xiaonong Cheng

2006 ◽  
Vol 129 (4) ◽  
pp. 485-490 ◽  
Author(s):  
A. Chillman ◽  
M. Ramulu ◽  
M. Hashish

An experimental study was conducted to explore the surface preparation as well as the effects of high-pressure waterjet peening at 600MPa on the surface integrity and finish of metals. The concept of larger droplet size and multiple droplet impacts resulting from an ultra-high-pressure waterjet was used to explore and develop the peening process. A combination of microstructure analysis, microhardness measurements, and profilometry were used in determining the depth of plastic deformation and surface finish that result from the surface treatment process. It was found that waterjet peening at 600MPa induces plastic deformation to greater depths in the subsurface layer of metals than laser shock peening. The degree of plastic deformation and the state of the material surface were found to be strongly dependent on the peening conditions and desired surface roughness. Based on these first investigation results, water peening at 600MPa may serve as a new method for introducing compressive residual stresses in engineering components.


2020 ◽  
Author(s):  
Alexander Sokol ◽  
Igor Kupriyanov ◽  
Yurii Seryotkin ◽  
Ella Sokol

<p>The current flux of nitrogen into the mantle in subduction zones is about three times its amount outgassing at mid-ocean ridges, arc and intraplate volcanoes, i.e., some efficient nitrogen hosts and carriers should exist in slabs. The K<sup>+</sup> → (NH<sub>4</sub><sup>+</sup>) substitution in silicate minerals is possible only within limited redox-favorable parts of slabs. Whether nitrogen can be transported and immobilized in the mantle as part of solids by some redox-independent mechanisms? The experimental study of the muscovite-NH<sub>3</sub>-N<sub>2</sub>-H<sub>2</sub>O and eclogite+muscovite-NH<sub>3</sub>-N<sub>2</sub>-H<sub>2</sub>O systems at 6.3-7.8 GPa and 1000 to 1200°C shows that NH<sub>3</sub>- and N<sub>2</sub>-rich K-cymrite can be stable in metapelite and act as a redox insensitive carrier of nitrogen to mantle depths >200 km in downgoing slabs. This ability is related to its unique clathrate structure that can accommodate three species of nitrogen: N<sub>2</sub> and NH<sub>3</sub> molecules in cages and (NH<sub>4</sub>)<sup>+</sup> substituting for K<sup>+</sup>, while imprisoned N<sub>2</sub> and NH<sub>3</sub> were first discovered in cages of ultra-high pressure minerals. The storage capacity K-cymrite with respect to nitrogen increases from 2.9 to 6.3 wt.% with increase of fO<sub>2 </sub>from ~IW to ~NNO, at the N<sub>2</sub>/(NH<sub>3</sub>+N<sub>2</sub>) ratio in fluid from 0.1 to 0.9. Comparison of equilibrated muscovite and K-cymrite synthesized at 7.8 GPa, 1070°C, and fO<sub>2 </sub>~IW demonstrates that the clathrate mechanism of nitrogen entrapment by aluminosilicates (in the form of N<sub>2</sub> and NH<sub>3 </sub>molecules) is much more efficient than the K<sup>+ </sup>® (NH<sub>4</sub><sup>+</sup>) substitution even in strongly reduced conditions. The presence of an N-bearing fluid in the studied systems stabilizes the K-cymrite structure. Muscovite does not convert to K-cymrite in the absence of NH<sub>3</sub>-N<sub>2</sub>-bearing fluid within 7.8 GPa and 1070-1120°C. Our estimates of normalized volume per non-hydrogen atom show that N<sub>2</sub>-bearing cymrite is the densest in the series of K-cymrite with cages filled to different degrees: K-Cym<sub>NH3</sub> > K-Cym<sub>H2O</sub> > K-Cym<sub>N2</sub> and is thus the most stable among cymrite-type compounds under high pressure.</p><p><em>The research was performed by a grant of the Russian Science Foundation (16-17-10041).</em></p>


Sign in / Sign up

Export Citation Format

Share Document