Gas-Phase Structures of Ketene and Acetic Acid from Acetic Anhydride Using Very-High-Temperature Gas Electron Diffraction

2016 ◽  
Vol 120 (12) ◽  
pp. 2041-2048 ◽  
Author(s):  
Sandra J. Atkinson ◽  
Robert Noble-Eddy ◽  
Sarah L. Masters
Keyword(s):  
Acetic Acid ◽  
High Temperature ◽  
Electron Diffraction ◽  
Acetic Anhydride ◽  
Gas Phase ◽  
Gas Electron Diffraction ◽  
Phase Structures ◽  
Very High ◽  
High Temperature Gas

scholarly journals Hydroxyl, water, ammonia, carbon monoxide and neutral carbon towards the Sgr A complex

2013 ◽  
Vol 9 (S303) ◽  
pp. 97-99
Author(s):  
R. Karlsson ◽  
Aa. Sandqvist ◽  
Å. Hjalmarson ◽  
A. Winnberg ◽  
K. Fathi ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
High Temperature ◽  
Open Access ◽  
Gas Phase ◽  
Combined Action ◽  
Circumnuclear Disk ◽  
Sgr A ◽  
Grain Surface ◽  
Very High ◽  
High Temperature Gas

AbstractWe observed Hydroxyl, water, ammonia, carbon monoxide and neutral carbon towards the +50 km s−1 cloud (M−0.02−0.07), the circumnuclear disk (CND) and the +20 km s−1 (M−0.13−0.08) cloud in the Sgr A complex with the VLA, Odin and SEST. Strong OH absorption, H2O emission and absorption lines were seen at all three positions. Strong C18O emissions were seen towards the +50 and +20 km s−1 clouds. The CND is rich in H2O and OH, and these abundances are considerably higher than in the surrounding clouds, indicating that shocks, star formation and clump collisions prevail in those objects. A comparison with the literature reveals that it is likely that PDR chemistry including grain surface reactions, and perhaps also the influences of shocks has led to the observed abundances of the observed molecular species studied here. In the redward high-velocity line wings of both the +50 and +20 km s−1 clouds and the CND, the very high H2O abundances are suggested to be caused by the combined action of shock desorption from icy grain mantles and high-temperature, gas-phase shock chemistry. Only three of the molecules are briefly discussed here. For OH and H2O three of the nine observed positions are shown, while a map of the C18O emission is provided. An extensive paper was recently published with Open Access (Karlsson et al. 2013, A&A 554, A141).

Comparative Study of GaN Growth Process by MOVPE

1999 ◽  
Vol 572 ◽  
Author(s):  
Jingxi Sun ◽  
J. M. Redwing ◽  
T. F. Kuech
Keyword(s):  
High Temperature ◽  
Comparative Study ◽  
Gas Phase ◽  
Residence Time ◽  
Gas Flow ◽  
Flow Sheet ◽  
Flow Zone ◽  
High Quality ◽  
Phase Temperature ◽  
High Temperature Gas

ABSTRACTA comparative study of two different MOVPE reactors used for GaN growth is presented. Computational fluid dynamics (CFD) was used to determine common gas phase and fluid flow behaviors within these reactors. This paper focuses on the common thermal fluid features of these two MOVPE reactors with different geometries and operating pressures that can grow device-quality GaN-based materials. Our study clearly shows that several growth conditions must be achieved in order to grow high quality GaN materials. The high-temperature gas flow zone must be limited to a very thin flow sheet above the susceptor, while the bulk gas phase temperature must be very low to prevent extensive pre-deposition reactions. These conditions lead to higher growth rates and improved material quality. A certain range of gas flow velocity inside the high-temperature gas flow zone is also required in order to minimize the residence time and improve the growth uniformity. These conditions can be achieved by the use of either a novel reactor structure such as a two-flow approach or by specific flow conditions. The quantitative ranges of flow velocities, gas phase temperature, and residence time required in these reactors to achieve high quality material and uniform growth are given.

Gas-phase structures of ethynyl- and vinyl pentafluorosulfur derivatives: an electron diffraction and microwave spectroscopy study

1991 ◽  
Vol 249 (2-4) ◽  
pp. 285-295 ◽  
Author(s):  
Petra Zylka ◽  
Dines Christen ◽  
Heinz Oberhammer ◽  
Gary L. Gard ◽  
R.J. Terjeson
Keyword(s):  
Electron Diffraction ◽  
Gas Phase ◽  
Microwave Spectroscopy ◽  
Spectroscopy Study ◽  
Phase Structures

Improved synthesis and crystal structure of the parent 1,3,5-trisilacyclohexane

2016 ◽  
Vol 71 (1) ◽  
pp. 77-79 ◽  
Author(s):  
Eugen Weisheim ◽  
Hans-Georg Stammler ◽  
Norbert W. Mitzel
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Electron Diffraction ◽  
Gas Phase ◽  
Gaseous Phase ◽  
Chair Conformation ◽  
Gas Electron Diffraction ◽  
State Structure ◽  
Synthesis And Crystal Structure ◽  
Bond Lengths

AbstractThe crystal structure and an improved synthesis of 1,3,5-trisilacyclohexane are reported. The solid state structure is compared with the reported structure determined in the gas phase by gas electron diffraction (GED). 1,3,5-Trisilacyclohexane adopts a chair conformation in the solid state. The Si–C bond lengths as well as all angles of 1,3,5-trisilacyclohexane in the solid state have similar dimensions compared to the structure in the gaseous phase.

scholarly journals Conceptual Core Design Study of the Very High Temperature Gas-Cooled Reactor (VHTR) Upgrading the Core Performance by Using Multihole-Type Fuel

2008 ◽  
Vol 7 (1) ◽  
pp. 32-43 ◽  
Author(s):  
Kazutaka OHASHI ◽  
Tetsuo NISHIHARA ◽  
Kazuhiko KUNITOMI ◽  
Masaaki NAKANO ◽  
Yujiro TAZAWA ◽  
...  
Keyword(s):  
High Temperature ◽  
Design Study ◽  
The Core ◽  
Conceptual Core ◽  
Very High ◽  
Type Fuel ◽  
High Temperature Gas
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