Probing Furanose Ring Conformation by Gas-Phase Computational Methods:  Energy Profile and Structural Parameters in Methyl β-d-Arabinofuranoside as a Function of Ring Conformation

2000 ◽  
Vol 65 (16) ◽  
pp. 4954-4963 ◽  
Author(s):  
Matthew T. Gordon ◽  
Todd L. Lowary ◽  
Christopher M. Hadad
Keyword(s):  
Gas Phase ◽  
Computational Methods ◽  
Structural Parameters ◽  
Energy Profile ◽  
Ring Conformation

Microwave Spectra and Gas-Phase Structural Parameters of Bis(η5-cyclopentadienyl)tungsten Dihydride

2007 ◽  
Vol 26 (8) ◽  
pp. 2070-2076 ◽  
Author(s):  
Brandon S. Tackett ◽  
Chandana Karunatilaka ◽  
Adam M. Daly ◽  
Stephen G. Kukolich
Keyword(s):  
Gas Phase ◽  
Structural Parameters ◽  
Microwave Spectra

Analysis of Decisive Structural Parameters and Acidic Property of Zeolites for Gas‐Phase Alkylation of Benzene with Ethylene

2021 ◽  
Vol 6 (42) ◽  
pp. 11779-11787
Author(s):  
Yunping Zhai ◽  
Youju Wang ◽  
Junwen Chen ◽  
Shihang Liang ◽  
Yongrui Wang ◽  
...  
Keyword(s):  
Gas Phase ◽  
Structural Parameters ◽  
Acidic Property ◽  
Alkylation Of Benzene

Refinement of the structural parameters of potassium metaborate in the gas phase

1984 ◽  
Vol 25 (3) ◽  
pp. 492-493 ◽  
Author(s):  
Yu. S. Ezhov ◽  
S. M. Tolmachev
Keyword(s):  
Gas Phase ◽  
Structural Parameters

Noncontinuum Gas-Phase Heat Transfer From a Heated Microbeam to the Adjacent Substrate

2005 ◽  
Author(s):  
M. A. Gallis ◽  
J. R. Torczynski ◽  
D. J. Rader ◽  
B. L. Bainbridge
Keyword(s):  
Heat Transfer ◽  
Gas Phase ◽  
Computational Methods ◽  
Direct Simulation Monte Carlo ◽  
Navier Stokes ◽  
Temperature Jumps ◽  
Thermal Actuation ◽  
Accommodation Coefficients ◽  
Low Pressures ◽  
Good Agreement

Noncontinuum gas-phase heat transfer in two microscale geometries is investigated using two computational methods. The motivation is microscale thermal actuation produced by heating-induced expansion of a near-substrate microbeam in air. The first geometry involves a 1-μm microgap filled with gas and bounded by parallel solid slabs. The second geometry involves a heated I-shaped microbeam 2 μm from the adjacent substrate, with gas in between. Two computational methods are applied. The Navier-Stokes slip-jump (NSSJ) method uses continuum heat transfer in the gas, with temperature jumps at boundaries to treat noncontinuum effects. The Direct Simulation Monte Carlo (DSMC) method uses computational molecules to simulate noncontinuum gas behavior accurately. For the microgap, the heat-flux values from both methods are in good agreement for all pressures and accommodation coefficients. For the microbeam, there is comparably good agreement except for cases with low pressures and near-unity accommodation coefficients. The causes of this discrepancy are discussed.

scholarly journals Bar effect on gas-phase abundance gradients. I. Data sample and chemical abundances

2020 ◽  
Vol 500 (2) ◽  
pp. 2359-2379 ◽  
Author(s):  
A Zurita ◽  
E Florido ◽  
F Bresolin ◽  
E Pérez-Montero ◽  
I Pérez
Keyword(s):  
Emission Line ◽  
Gas Phase ◽  
Direct Method ◽  
Structural Parameters ◽  
Companion Paper ◽  
Strong Line ◽  
H Ii Regions ◽  
Chemical Abundances ◽  
The Galaxy ◽  
H Ii Region

ABSTRACT Studies of gas-phase radial metallicity profiles in spirals published in the last decade have diminished the importance of galactic bars as agents that mix and flatten the profiles, contradicting results obtained in the 1990s. We have collected a large sample of 2831 published H ii region emission-line fluxes in 51 nearby galaxies, including objects both with and without the presence of a bar, with the aim of revisiting the issue of whether bars affect the radial metal distribution in spirals. In this first paper of a series of two, we present the galaxy and the H ii region samples. The methodology is homogeneous for the whole data sample and includes the derivation of H ii region chemical abundances, structural parameters of bars and discs, galactocentric distances, and radial abundance profiles. We have obtained O/H and N/O abundance ratios from the Te-based (direct) method for a subsample of 610 regions, and from a variety of strong-line methods for the whole H ii region sample. The strong-line methods have been evaluated in relation to the Te-based one from both a comparison of the derived O/H and N/O abundances for individual H ii regions and a comparison of the abundance gradients derived from both methodologies. The median value and the standard deviation of the gradient distributions depend on the abundance method, and those based on the O3N2 indicator tend to flatten the steepest profiles, reducing the range of observed gradients. A detailed analysis and discussion of the derived O/H and N/O radial abundance gradients and y-intercepts for barred and unbarred galaxies is presented in the companion Paper II. The whole H ii region catalogue including emission-line fluxes, positions, and derived abundances is made publicly available on the CDS VizieR facility, together with the radial abundance gradients for all galaxies.

Sign in / Sign up

Export Citation Format

Share Document