Fabricating M/Al2O3/cordierite (M = Cr, Mn, Fe, Co, Ni and Cu) monolithic catalysts for ethyl acetate efficient oxidation: Unveiling the role of water vapor and reaction mechanism

Fuel ◽  
2021 ◽  
Vol 303 ◽  
pp. 121244
Author(s):  
Mudi Ma ◽  
Rui Yang ◽  
Zeyu Jiang ◽  
Changwei Chen ◽  
Qiyuan Liu ◽  
...  
Keyword(s):  
Water Vapor ◽  
Reaction Mechanism ◽  
Ethyl Acetate ◽  
Monolithic Catalysts

Oxidations ofNω-Hydroxyarginine Analogues and VariousN-Hydroxyguanidines by NO Synthase II: Key Role of Tetrahydrobiopterin in the Reaction Mechanism and Substrate Selectivity

2001 ◽  
Vol 14 (2) ◽  
pp. 202-210 ◽  
Author(s):  
Catherine Moali ◽  
Jean-Luc Boucher ◽  
Axelle Renodon-Corniere ◽  
Dennis J. Stuehr ◽  
Daniel Mansuy
Keyword(s):  
Reaction Mechanism ◽  
No Synthase ◽  
Substrate Selectivity

Role of water vapor in oxidative decomposition of calcium sulfide

Fuel ◽  
2004 ◽  
Vol 83 (6) ◽  
pp. 671-677 ◽  
Author(s):  
Shengji Wu ◽  
Md.Azhar Uddin ◽  
Shinsuke Nagamine ◽  
Eiji Sasaoka
Keyword(s):  
Water Vapor ◽  
Calcium Sulfide ◽  
Oxidative Decomposition

Extreme Surface Winds During Landfalling Atmospheric Rivers: The Modulating Role of Near-Surface Stability

2021 ◽  
Author(s):  
Terence J. Pagano ◽  
Duane E. Waliser ◽  
Bin Guan ◽  
Hengchun Ye ◽  
F. Martin Ralph ◽  
...  
Keyword(s):  
Water Vapor ◽  
Static Stability ◽  
Vapor Transport ◽  
Water Vapor Transport ◽  
Surface Winds ◽  
Near Surface ◽  
Extreme Surface ◽  
Atmospheric Rivers ◽  
Explained Variance

AbstractAtmospheric rivers (ARs) are long and narrow regions of strong horizontal water vapor transport. Upon landfall, ARs are typically associated with heavy precipitation and strong surface winds. A quantitative understanding of the atmospheric conditions that favor extreme surface winds during ARs has implications for anticipating and managing various impacts associated with these potentially hazardous events. Here, a global AR database (1999–2014) with relevant information from MERRA-2 reanalysis, QuikSCAT and AIRS satellite observations are used to better understand and quantify the role of near-surface static stability in modulating surface winds during landfalling ARs. The temperature difference between the surface and 1 km MSL (ΔT; used here as a proxy for near-surface static stability), and integrated water vapor transport (IVT) are analyzed to quantify their relationships to surface winds using bivariate linear regression. In four regions where AR landfalls are common, the MERRA-2-based results indicate that IVT accounts for 22-38% of the variance in surface wind speed. Combining ΔT with IVT increases the explained variance to 36-52%. Substitution of QuikSCAT surface winds and AIRS ΔT in place of the MERRA-2 data largely preserves this relationship (e.g., 44% compared to 52% explained variance for USA West Coast). Use of an alternate static stability measure–the bulk Richardson number–yields a similar explained variance (47%). Lastly, AR cases within the top and bottom 25% of near-surface static stability indicate that extreme surface winds (gale or higher) are more likely to occur in unstable conditions (5.3%/14.7% during weak/strong IVT) than in stable conditions (0.58%/6.15%).

The Role of Binary and Ion Nucleation of Sulfuric Acid and Water Vapor in the Dynamics of Sulfate Aerosol Formation in the Atmosphere

2021 ◽  
pp. 53-60
Author(s):  
A. E. Aloyan ◽  
◽  
A. N. Yermakov ◽  
V. O. Arutyunyan ◽  
◽  
...  
Keyword(s):  
Water Vapor ◽  
Sulfuric Acid ◽  
Three Dimensional ◽  
Ionization Rate ◽  
Sulfate Aerosol ◽  
Aerosol Formation ◽  
Three Dimensional Model ◽  
Aerosol Composition ◽  
Transport And Transformation

The results of one-dimensional calculations of the height profiles of nucleated sulfate aerosol particles for the northern mid-latitudes and tropics in winter are presented. Numerical calculations were performed using a three-dimensional model of the transport and transformation of multicompo- nent gas and aerosol substances in the atmosphere, incorporating photochemistry, nucleation involving neutral molecules and ions, as well as condensation/evaporation and coagulation. It is found that the resulting dynamics of the formation of aerosol particle nuclei is not a simple sum of ion and binary (water vapor/sulfuric acid) nucleation rates. This dynamics is determined by the ratio of critical radii of nucleated particles due to binary and ion nucleation of these substances (rcr_bin and rcr_ion) depending on temperature, relative humidity, and ionization rate. This should be taken into account in modeling the gas and aerosol composition of the atmosphere and comparing calculated and observed data.

scholarly journals Upper Tropospheric Water Vapor Transport from Indian to Sahelian Regions

Atmosphere ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 403 ◽  
Author(s):  
Abdoulaye Sy ◽  
Bouya Diop ◽  
Joël Van Baelen ◽  
Christophe Duroure ◽  
Yahya Gour ◽  
...  
Keyword(s):  
Water Vapor ◽  
Indian Monsoon ◽  
Water Vapor Transport ◽  
Substantial Part ◽  
Monsoon Region ◽  
Direct Role ◽  
Air Masses ◽  
Upper Troposphere ◽  
Tropical Easterly Jet

We present a study of upper tropospheric westward transport of air masses coming from the Indian monsoon zone over the period 1998–2008. The objective is to characterize upper tropospheric transport of water vapor from the Indian to Sahelian regions, and to improve the understanding of the dynamical mechanisms that govern water vapor variations in West Africa and the interconnections between India and the Sahel, focusing on the direct role of the Indian monsoon region on Sahel tropospheric water vapor and precipitation. The calculations of forward trajectories with LACYTRAJ (LACY TRAJectory code) and humidity fluxes show that a substantial part (40 to 70% at 300 hPa) of trajectories coming from the upper troposphere of the monsoon region crossed the Sahelian region in a few days (3–14 days), and water vapor fluxes connecting these two regions are established when the Indian monsoon begins at latitudes higher than 15° N in its south–north migration. The intensity and orientation of water vapor fluxes are related to the tropical easterly jet, but they are from the east above the high convection zones. Between 1998 and 2008, these fluxes between the 500–300 hPa pressure levels are associated with precipitation in Sahel only if they are from the east and with an intensity exceeding 8 kg·(m·s)−1.

Reaction Mechanism and Role of the Support in the Partial Oxidation of Methane on Rh/Al2O3

1996 ◽  
Vol 159 (2) ◽  
pp. 418-426 ◽  
Author(s):  
Dezheng Wang ◽  
Olivier Dewaele ◽  
Ann M.De Groote ◽  
Gilbert F. Froment
Keyword(s):  
Reaction Mechanism ◽  
Partial Oxidation ◽  
Partial Oxidation Of Methane ◽  
Oxidation Of Methane

scholarly journals Simplified climate modelling to size economic boundaries

2020 ◽  
Author(s):  
Thomas Anderl
Keyword(s):  
Climate Change ◽  
Economic Growth ◽  
Water Vapor ◽  
Translational Energy ◽  
Climate Modelling ◽  
Foreseeable Future ◽  
Natural Processes ◽  
Scientific Results ◽  
Public Demand

The broader public demand reproducibility of scientific results particularly related to hot societal topics. The present work applies the 80:20-rule to climate change, concentrating on the essentials from the readily observable and identifying the inherent relationships in their potential simplicity. Observations on 400 Mio. years of paleoclimate are found to well constrain the compound universal climate role of CO 2. Combined with observations on the industrial-era atmospheric CO 2 and ocean heat evolvement, climate risk assessment and projections on the economic boundaries are performed. Independently in conjunction with energy budget studies, simple models are presented for the fundamental natural processes related to: (i) water vapor and CO 2 effect on temperature; (ii) transient and equilibrium climate; (iii) heating from the V/R-T (vibrational/rotational to translational) energy transfer; (iv) Earth emissivity changing with surface temperature; (v) water vapor for Earths energy balance maintenance; (vi) rainfall pattern altering with temperature; (vii) natures reaction on the anthropogenic energy consumption. In conclusion, realistic estimates point at precluding positive economic growth for the foreseeable future if temperatures are to be given a reasonable chance to become sustainably contained within sensible limits.

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