scholarly journals The evidence for unusually high hydrogen abundances in the central part of Valles Marineris on Mars

Icarus ◽  
2021 ◽  
pp. 114805
Author(s):  
I. Mitrofanov ◽  
A. Malakhov ◽  
M. Djachkova ◽  
D. Golovin ◽  
M. Litvak ◽  
...  
Keyword(s):  
High Hydrogen ◽  
Valles Marineris

Microscopic versus process parameters in heavy-oil upgrading

1992 ◽  
Vol 50 (1) ◽  
pp. 366-367
Author(s):  
V.A. Munoz ◽  
R.J. Mikula ◽  
C. Payette ◽  
W.W. Lam
Keyword(s):  
Molecular Weight ◽  
Liquid Fuels ◽  
Chemical Components ◽  
Heavy Oils ◽  
Synthetic Fuels ◽  
High Hydrogen ◽  
Optical Texture ◽  
Polar Groups ◽  
Anisotropic Character ◽  
Planar Molecules

The transformation of high molecular weight components present in heavy oils into useable liquid fuels requires their decomposition by means of a variety of processes. The low molecular weight species produced recombine under controlled conditions to generate synthetic fuels. However, an important fraction undergo further recombination into higher molecular weight components, leading to the formation of coke. The optical texture of the coke can be related to its originating components. Those with high sulfur and oxygen content tend to produce cokes with small optical texture or fine mosaic, whereas compounds with relatively high hydrogen content are likely to produce large optical texture or domains. In addition, the structure of the parent chemical components, planar or nonplanar, determines the isotropic or anisotropic character of the coke. Planar molecules have a tendency to align in an approximately parallel arrangement to initiate the formation of the nematic mesophase leading to the formation of anisotropic coke. Nonplanar highly alkylated compounds and/or those rich in polar groups form isotropic coke. The aliphatic branches produce steric hindrance to alignment, whereas the polar groups participate in cross-linking reactions.

Nanocrystalline silicon ( nc-Si ) from single ion beam sputtering

2003 ◽  
Vol 762 ◽  
Author(s):  
Z.B. Zhou ◽  
G.M. Hadi ◽  
R.Q. Cui ◽  
Z.M. Ding ◽  
G. Li
Keyword(s):  
Solar Cell ◽  
Ion Beam ◽  
Nanocrystalline Silicon ◽  
Silicon Films ◽  
Chamber Pressure ◽  
Ion Beam Sputtering ◽  
High Hydrogen ◽  
Beam Sputtering ◽  
Si Films ◽  
Nanocrystalline Silicon Films

AbstractBased on a small set of selected publications on the using of nanocrystalline silicon films (nc-Si) for solar cell from 1997 to 2001, this paper reviews the application of nc-Si films as intrinsic layers in p-i-n solar cells. The new structure of nc-Si films deposited at high chamber pressure and high hydrogen dilution have characters of nanocrystalline grains with dimension about several tens of nanometer embedded in matrix of amorphous tissue and a high volume fraction of crystallinity (60~80%). The new nc-Si material have optical gap of 1.89 eV. The efficiency of this single junction solar cell reaches 8.7%. This nc-Si layer can be used not only as an intrinsic layer and as a p-type layer. Also nanocrystalline layer may be used as a seed layer for the growth of polycrystalline Si films at a low temperature.We used single ion beam sputtering methods to synthesize nanocrystalline silicon films successfully. The films were characterized with the technique of X-ray diffraction, Atomic Force Micrographs. We found that the films had a character of nc-amorphous double phase structure. Conductivity test at different temperatures presented the transportation of electrons dominated by different mechanism within different temperature ranges. Photoconductivity gains of the material were obtained in our recent investigation.

Effect of high hydrogen enrichment on the outer-shear-layer flame of confined lean premixed CH4/H2/air swirl flames

2021 ◽  
Author(s):  
Runze Mao ◽  
Jinhua Wang ◽  
Weijie Zhang ◽  
Zhenhua An ◽  
Wenjun Lin ◽  
...  
Keyword(s):  
Shear Layer ◽  
High Hydrogen ◽  
Lean Premixed ◽  
Hydrogen Enrichment

scholarly journals High Hydrogen Mobility in an Amide–Borohydride Compound Studied by Quasielastic Neutron Scattering

2021 ◽  
pp. 2100620
Author(s):  
Neslihan Aslan ◽  
Gökhan Gizer ◽  
Claudio Pistidda ◽  
Martin Dornheim ◽  
Martin Müller ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
High Hydrogen ◽  
Quasielastic Neutron ◽  
Quasielastic Neutron Scattering

scholarly journals Performance of Sulfide-Driven Fuel Cell Aerated by Venturi Tube Ejector

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 694
Author(s):  
Venko N. Beschkov ◽  
Elena N. Razkazova-Velkova ◽  
Martin S. Martinov ◽  
Stefan M. Stefanov
Keyword(s):  
Hydrogen Sulfide ◽  
Fuel Cell ◽  
Electric Energy ◽  
Gas Diffusion ◽  
Venturi Tube ◽  
Polluted Water ◽  
The Black Sea ◽  
High Hydrogen ◽  
Mass Transfer Limitation ◽  
Pure Graphite

Hydrogen sulfide is frequently met in natural waters, like mineral springs, but mostly it is found in marine water with low renewal rate. The Black Sea has extremely high hydrogen sulfide content. It can be utilized in different ways, but the most promising one is direct conversion into electricity. This result can be attained by a sulfide-driven fuel cell (SDFC), converting sulfide to sulfate thus releasing electric energy up to 24 GJ/t. One of the most important problems is the mass transfer limitation on oxygen transfer in the cathode space of the fuel cell. This problem can be solved using a gas diffusion electrode or highly efficient saturation by oxygen in an ejector of the Venturi tube type. This work presents experimental data in laboratory-scale SDFC for sulfide conversion into sulfate, sulfite and polysulfide releasing different amounts of electric energy. Two types of aeration are tested: direct air blow and Venturi-tube ejector. Besides pure graphite, two catalysts, i.e., cobalt spinel and zirconia-doped graphite were tested as anodes. Experiments were carried out at initial sulfide concentrations from 50 to 300 mg/L. Sulfate, sulfite and thiosulfate ions were detected in the outlet solutions from the fuel cell. The electrochemical results show good agreement with the chemical analyses. Most of the results show attained high efficiencies of the fuel cell, i.e. up to 80%. The practical applications of this method can be extended for other purposes, like treatment of polluted water together with utilization as energy.

Turbulent Consumption Speeds of High Hydrogen Content Fuels From 1–20 atm

2013 ◽  
Author(s):  
Prabhakar Venkateswaran ◽  
Andrew D. Marshall ◽  
Jerry M. Seitzman ◽  
Tim C. Lieuwen
Keyword(s):  
Burning Rate ◽  
Hydrogen Content ◽  
Pressure Effects ◽  
Pressure Sensitivity ◽  
Mass Burning Rate ◽  
High Hydrogen ◽  
High Hydrogen Content ◽  
Fuel Blends ◽  
Correlate Data

This work describes measurements and analysis of the turbulent consumption speeds, ST,GC, of H2/CO fuel blends. We report measurements of ST,GC at pressures and normalized turbulence intensities, u′rms/SL,0 up to 20 atm and 1800, respectively for a variety of H2/CO mixtures and equivalence ratios. In addition, we present correlations of these data using laminar burning velocities of highly stretched flames, SL,max, derived from quasi-steady leading points models. These analyses show that SL,max can be used to correlate data over a broad range of fuel compositions, but do not capture the pressure sensitivity of ST,GC. We suggest that these pressure effects are more fundamentally a manifestation of non-quasi-steady behavior in the mass burning rate at the flame leading points.

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