Selective N2/H2O Adsorption onto 2D Amphiphilic Amorphous Photocatalysts for Ambient Gas-Phase Nitrogen Fixation

2021 ◽  
pp. 120240
Author(s):  
Ziyang Lu ◽  
Sandra Elizabeth Saji ◽  
Julien Langley ◽  
Yunxiang Lin ◽  
Zhirun Xie ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Gas Phase ◽  
Ambient Gas

scholarly journals Interferometry of Gas-Phase Flows during Selective Laser Melting

2019 ◽  
Vol 10 (1) ◽  
pp. 231 ◽  
Author(s):  
Pavel A. Podrabinnik ◽  
Alexander E. Shtanko ◽  
Roman S. Khmyrov ◽  
Andrey D. Korotkov ◽  
Andrey V. Gusarov
Keyword(s):  
Gas Phase ◽  
Selective Laser Melting ◽  
Laser Power ◽  
Metal Vapor ◽  
Gas Jet ◽  
Laser Melting ◽  
Pressure Fields ◽  
Ambient Gas ◽  
Processing Zone

Gas-phase flows occurring in a plume in a processing zone during selective laser melting (SLM) can significantly affect the quality of the process. To further enhance SLM performance, the characteristics of the flows should be considered. In this article, the vapor-gas jet emerging from the laser processing zone was studied. It was visualized by interferometry to evaluate flow velocity, geometry and changes in refractory index depending on laser power. The velocity and pressure fields of the vapor jet and the entrained ambient gas were estimated by mathematical modeling. It was shown that the increase of laser power led to higher jet velocity and greater change in its refractory index. The latter also was used to evaluate the content of metal vapor in the plume and its influence on the absorption of laser radiation.

scholarly journals SIFT-MS and FA-MS methods for ambient gas phase analysis: developments and applications in the UK

The Analyst ◽  
2015 ◽  
Vol 140 (8) ◽  
pp. 2573-2591 ◽  
Author(s):  
David Smith ◽  
Patrik Španěl
Keyword(s):  
Gas Phase ◽  
Phase Analysis ◽  
Breath Analysis ◽  
Exhaled Breath ◽  
Interstellar Chemistry ◽  
Exhaled Breath Analysis ◽  
Ambient Gas ◽  
The Uk

The origins of SIFT created to study interstellar chemistry and SIFT-MS developed for ambient gas and exhaled breath analysis and the UK centres in which these techniques are being exploited.

Numerical Study on High Prandtl Number Liquid Bridge

2013 ◽  
Vol 712-715 ◽  
pp. 1630-1633
Author(s):  
Ru Quan Liang ◽  
Shuo Yang ◽  
Fu Sheng Yan ◽  
Jun Hong Ji ◽  
Ji Cheng He
Keyword(s):  
Gas Phase ◽  
Liquid Bridge ◽  
Surface Deformation ◽  
Numerical Study ◽  
Mass Conservation ◽  
Ambient Air ◽  
Two Phase ◽  
High Prandtl Number ◽  
Free Surface Deformation ◽  
Ambient Gas

The overall numerical analysis of liquid bridge for high Pr number fluid and flow field of ambient air under the zero-gravity environment was carried out in the present paper. The paper used level set method of mass conservation to capture two phase interfaces. Not only the free surface deformation was considered, but also the effect of ambient gas was taken into account. Simultaneously, results of stream function in liquid bridge and ambient gas-phase were given.

Ordered defects in the oxides of uranium

1986 ◽  
Vol 406 (1831) ◽  
pp. 325-344 ◽  
Keyword(s):  
Gas Phase ◽  
Point Defects ◽  
Random Distribution ◽  
Structural Models ◽  
Fluorite Structure ◽  
Structural Units ◽  
Oxygen System ◽  
Interstitial Defects ◽  
Local Properties ◽  
Ambient Gas

Like some other oxides of the actinide elements, uranium dioxide has a fluorite structure and a propensity towards deviation from simple stoichiometry. Because oxygen can be transferred with ease between the UO 2 lattice and the ambient gas phase, gross departures from stoichio­metry occur readily. Diffraction data have shown that structural models of the hyperstoichiometric phases U 4 O 9 and U 3 O 7 cannot be based on a random distribution of point defects. Instead, interaction between interstitial defects produces microscopic substructures or clusters intro­ducing specific local properties. Spectroscopic evidence is presented together with the alternative cluster arrangements which are currently proposed as the basic structural units occurring in the hyperstoichiometric oxides of uranium. From this base a new relationship for the structure of the uranium-oxygen system has been developed for the compositional range UO 2 -UO 3 .

Healing of thermocapillary film rupture by viscous heating

2019 ◽  
Vol 872 ◽  
pp. 308-326 ◽  
Author(s):  
E. Kirkinis ◽  
A. V. Andreev
Keyword(s):  
Surface Tension ◽  
Gas Phase ◽  
Liquid Films ◽  
Solid Substrate ◽  
Viscous Heating ◽  
Shear Stresses ◽  
Heating Effect ◽  
Film Rupture ◽  
Surface Shear ◽  
Ambient Gas

Thin liquid films sitting on a heated solid substrate and surrounded by a colder ambient gas phase are strongly affected by surface-shear stresses induced by surface tension and temperature gradients, as well as by viscous and capillary forces. The temperature dependence of surface tension may lead to thinning of liquid-film depressions promoting instability which takes place when a critical temperature difference $\unicode[STIX]{x0394}\unicode[STIX]{x1D717}_{cr}$ between the substrate and the ambient gas phase is exceeded. In this article we show theoretically that viscous heating, previously neglected in related literature, may delay or suppress the thermocapillary instability and leads to film healing. The viscous heating effect, by inhibiting heat transfer, prevents the system from reaching the critical value $\unicode[STIX]{x0394}\unicode[STIX]{x1D717}_{cr}$ required to bring about instability. As a consequence, the system remains within the stability region, suppressing film rupture. The presence of the viscous heating effect leads to a persistent circulating motion of two counter-rotating vortices lying diametrically opposite to a depression of the liquid–gas interface reducing the wavelength of disturbances to one half of its initial value. This effect has yet to be observed in experiment.

Monitoring energy conversion in photosystem I of cyanobacterial heterocysts by photoacoustic spectroscopy

1986 ◽  
Vol 64 (9) ◽  
pp. 1136-1138 ◽  
Author(s):  
Robert Carpentier ◽  
Hans C. P. Matthijs ◽  
Roger M. Leblanc ◽  
Geoffrey Hind
Keyword(s):  
Nitrogen Fixation ◽  
Electron Transport ◽  
Energy Conversion ◽  
Gas Phase ◽  
Photosystem I ◽  
Photoacoustic Spectroscopy ◽  
Cyclic Electron Transport ◽  
Optimal Conditions ◽  
Anabaena 7120 ◽  
Cyanobacterium Anabaena

Photoacoustic spectroscopy was used to monitor photosynthetic energy storage in heterocysts isolated from the cyanobacterium Anabaena 7120. Three main energy-conversion pathways have been identified in these specialized cells: cyclic electron transport in photosystem I, nitrogen fixation, and respiration. The aim of this study was to define the conditions for estimating their interdependence. The gas phase (air, Ar, N2, H2) under which the sample was prepared or incubated, as well as the presence of electron donors (NADPH, NADH, H2) and KCN (an inhibitor of respiration), determined the relative flux through the pathways. Heterocysts in which respiration and nitrogen fixation are inhibited have afforded a useful system for specific study of cyclic electron transport around photosystem I. Under optimal conditions for photosystem I turnover, photochemical losses of above 20% were found.

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