New developments in the gas-phase rotational spectroscopy of high-temperature species and unstable molecules

1981 ◽  
Vol 71 ◽  
pp. 31 ◽  
Author(s):  
Manfred Winnewisser
Keyword(s):  
High Temperature ◽  
Gas Phase ◽  
Rotational Spectroscopy ◽  
New Developments ◽  
Unstable Molecules

High Temperature Corrosion Behavior of Si-Containing Alloys in the Gas Phase of Air-(Na2SO4+25.7mass%NaCl)

2011 ◽  
Vol 696 ◽  
pp. 272-277 ◽  
Author(s):  
Toto Sudiro ◽  
Tomonori Sano ◽  
Akira Yamauchi ◽  
Shoji Kyo ◽  
Osamu Ishibashi ◽  
...  
Keyword(s):  
High Temperature ◽  
Gas Phase ◽  
Corrosion Behavior ◽  
Elevated Temperatures ◽  
High Temperature Corrosion ◽  
Ni Content ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Corrosion Resistant Alloy ◽  
Si Content

The objective of this study is to develop an excellent corrosion resistant alloy for high temperature coating applications. The Si-containing alloys consisting of CoNiCrAlY and CrSi2 alloys with varying Si and Ni content respectively were prepared by spark plasma sintering (SPS) technique. The corrosion behavior of these alloys was investigated in the gas phase of air-(Na2SO4+25.7mass%NaCl) at elevated temperatures of 923, 1073 and 1273K. The results showed that CoNiCrAlY alloy with 30mass% Si content and CrSi2 alloy with 10mass% Ni content were the most effective materials for application in the gas phase of air-(Na2SO4+25.7mass%NaCl) due to the formation of protective Al2O3/SiO2 and SiO2 scale, respectively. Therefore, it is realized that CoNiCrAlY-30mass% Si and CrSi2-10mass% Si coating are very effective for improving of high temperature corrosion resistance of STBA21 steel.

High temperature superconductors for fusion applications and new developments for the HTS CroCo conductor design

2021 ◽  
Vol 172 ◽  
pp. 112739
Author(s):  
Michael J. Wolf ◽  
Christof Ebner ◽  
Walter H. Fietz ◽  
Reinhard Heller ◽  
Daniel Nickel ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperature Superconductors ◽  
New Developments ◽  
Fusion Applications

A gas phase investigation of titanium monoxide and atomic titanium using high temperature photoelectron spectroscopy

1984 ◽  
Vol 53 (2) ◽  
pp. 465-477 ◽  
Author(s):  
J.M. Dyke ◽  
B.W.J. Gravenor ◽  
G.D. Josland ◽  
R.A. Lewis ◽  
A. Morris
Keyword(s):  
High Temperature ◽  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Titanium Monoxide

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.

High-Temperature Equilibrium between High-Tc Oxide and Gas Phase

1991 ◽  
Vol 163 (1) ◽  
pp. 231-240 ◽  
Author(s):  
V. I. Tsidilkovskii ◽  
I. A. Leonidov ◽  
A. A. Lakhtin ◽  
V. A. Mezrin
Keyword(s):  
High Temperature ◽  
Gas Phase ◽  
High Tc ◽  
Temperature Equilibrium

Numerical Study of Bicomponent Droplet Vaporization in a High Pressure Environment

1996 ◽  
Author(s):  
J. Stengele ◽  
H.-J. Bauer ◽  
S. Wittig
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Gas Phase ◽  
Numerical Study ◽  
Droplet Evaporation ◽  
Single Component ◽  
Vapor Concentration ◽  
Diffusion Limit ◽  
Evaporation Process ◽  
Droplet Vaporization

The understanding of multicomponent droplet evaporation in a high pressure and high temperature gas is of great importance for the design of modern gas turbine combustors, since the different volatilities of the droplet components affect strongly the vapor concentration and, therefore, the ignition and combustion process in the gas phase. Plenty of experimental and numerical research is already done to understand the droplet evaporation process. Until now, most numerical studies were carried out for single component droplets, but there is still lack of knowledge concerning evaporation of multicomponent droplets under supercritical pressures. In the study presented, the Diffusion Limit Model is applied to predict bicomponent droplet vaporization. The calculations are carried out for a stagnant droplet consisting of heptane and dodecane evaporating in a stagnant high pressure and high temperature nitrogen environment. Different temperature and pressure levels are analyzed in order to characterize their influence on the vaporization behavior. The model employed is fully transient in the liquid and the gas phase. It accounts for real gas effects, ambient gas solubility in the liquid phase, high pressure phase equilibrium and variable properties in the droplet and surrounding gas. It is found that for high gas temperatures (T = 2000 K) the evaporation time of the bicomponent droplet decreases with higher pressures, whereas for moderate gas temperatures (T = 800 K) the lifetime of the droplet first increases and then decreases when elevating the pressure. This is comparable to numerical results conducted with single component droplets. Generally, the droplet temperature increases with higher pressures reaching finally the critical mixture temperature of the fuel components. The numerical study shows also that the same tendencies of vapor concentration at the droplet surface and vapor mass flow are observed for different pressures. Additionally, there is almost no influence of the ambient pressure on fuel composition inside the droplet during the evaporation process.

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