Chemisorption of Moisture-Induced Hydrogen and the Embrittlement Effects in Transition Metal Aluminides

1994 ◽  
Vol 364 ◽  
Author(s):  
Jian-Sheng Wang
Keyword(s):  
Water Vapor ◽  
Transition Metal ◽  
Thermodynamic Properties ◽  
Solid Solutions ◽  
Free Energies ◽  
Thermodynamic Models ◽  
Metal Aluminides

AbstractBased on simple thermodynamic models free energies of chemisorption of water vapor in transition metal aluminides and enthalpies and entropies of formation of solid solutions of hydrogen in the aluminides are derived. Susceptibilities of the aluminides to moisture-induced embrittlement are evaluated with these thermodynamic properties and compared with the susceptibilities to hydrogen-induced embrittlement.

THE HEAT OF WETTING OF SILK FIBROIN BY WATER

1955 ◽  
Vol 33 (5) ◽  
pp. 904-912 ◽  
Author(s):  
H. Brian Dunford ◽  
John L. Morrison
Keyword(s):  
Water Vapor ◽  
Adsorption Isotherm ◽  
Thermodynamic Properties ◽  
Silk Fibroin ◽  
Adsorption Process ◽  
Film Formation ◽  
Adsorbed Water ◽  
Water Vapor Adsorption ◽  
Free Energies ◽  
Heat Of Wetting

The heats of wetting by water of silk fibroin initially containing various amounts of adsorbed and desorbed water have been measured. These measurements along with the water vapor adsorption isotherm of Hutton and Gartside have been used to calculate the integral and differential heats, free energies, and entropies of adsorption. In contrast with cellulose, silk containing desorbed water evolves less heat than that containing adsorbed water. This fact suggests that any contribution by a heat of swelling term is very small for silk fibroin, so that the calculated thermodynamic properties probably can be assigned almost entirely to the adsorption process. The changes in the heats and entropies of adsorption appear to parallel the sequence of changes in film formation as revealed by surface area calculations.

Pressurizer Modeling: Using Different Thermodynamic Models and Comparing Results with RELAP Code Results

2013 ◽  
Vol 423-426 ◽  
pp. 1444-1448
Author(s):  
Samad Khani Moghanaki ◽  
Mohammad Rahgoshay
Keyword(s):  
Water Vapor ◽  
Thermodynamic Properties ◽  
Nuclear Power ◽  
Power Plants ◽  
Pressurized Water Reactor ◽  
Thermodynamic Models ◽  
Pressurized Water ◽  
Single Region ◽  
The World ◽  
Tank Pressure

In pressurized water nuclear power plants, pressurizer is applied to control the primary loop’s pressure during transient processes. There are different thermodynamic models, which calculate the pressurizer’s tank pressure and water/vapor thermodynamic properties in different times. In this article, single-region and two-region models have been employed to simulation of WWER-1000 type pressurizer. Here, the obtained pressure from both models has been compared with RELAP5/Mod3 code findings. The RELAP is a thermal-hydraulic code, which has been developed and accepted throughout the world for simulating loop flows, for example pressurized water reactor (PWR) systems together with their related scaled systems. Finally, the pressure results have been compared and indicate that the presented models accuracy, are acceptable. The differences between models and RELAP code results are justifiable.

scholarly journals Thermodynamic Properties of Solid Solutions between Di-calcium Silicate and Tri-calcium Phosphate

2012 ◽  
Vol 31 (4-5) ◽  
pp. 421-430 ◽  
Author(s):  
M. Hasegawa ◽  
Y. Kashiwaya ◽  
M. Iwase
Keyword(s):  
Calcium Phosphate ◽  
Thermodynamic Properties ◽  
Phase Diagrams ◽  
Regular Solution ◽  
Solid Solutions ◽  
Phosphorus Removal ◽  
Calcium Silicate ◽  
Regular Solution Model ◽  
Free Energies ◽  
Hot Metal

AbstractFor a better understanding of phosphorus removal from hot metal, the Gibbs free energies of solid solutions between di-calcium silicate and tri-calcium phosphate were derived through applications of solutions models. The regular solution model with the parameters determined in this study gave the activities of the components thermodynamically consistent with the literature data and the phase diagrams.

Electron energy loss near edge structures of intermetallic alloys and grain boundaries in NiAl

1996 ◽  
Vol 54 ◽  
pp. 522-523
Author(s):  
G.A. Botton ◽  
C.J. Humphreys
Keyword(s):  
High Temperature ◽  
Transition Metal ◽  
Energy Loss ◽  
Grain Boundaries ◽  
Industrial Applications ◽  
Edge Structure ◽  
Structural Applications ◽  
Yield Behaviour ◽  
Late Transition ◽  
Metal Aluminides

Transition metal aluminides are of great potential interest for high temperature structural applications. Although these materials exhibit good mechanical properties at high temperature, their use in industrial applications is often limited by their intrinsic room temperature brittleness. Whilst this particular yield behaviour is directly related to the defect structure, the properties of the defects (in particular the mobility of dislocations and the slip system on which these dislocations move) are ultimately determined by the electronic structure and bonding in these materials. The lack of ductility has been attributed, at least in part, to the mixed bonding character (metallic and covalent) as inferred from ab-initio calculations. In this work, we analyse energy loss spectra and discuss the features of the near edge structure in terms of the relevant electronic states in order to compare the predictions on bonding directly with spectroscopic experiments. In this process, we compare spectra of late transition metal (TM) to early TM aluminides (FeAl and TiAl) to assess whether differences in bonding can also be detected. This information is then discussed in terms of bonding changes at grain boundaries in NiAl.

Thermal prehistory, structure and high-temperature thermodynamic properties of Y2O3-CeO2 and Y2O3-ZrO2-CeO2 solid solutions

2020 ◽  
Author(s):  
Olga Yu Kurapova ◽  
Sergey M. Shugurov ◽  
Evgenia A. Vasil'eva ◽  
Daniil A. Savelev ◽  
Vladimir G. Konakov ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermodynamic Properties ◽  
Solid Solutions ◽  
Thermal Prehistory

A Rational Equation of State for Water and Water Vapor in the Critical Region

1964 ◽  
Vol 86 (3) ◽  
pp. 320-326 ◽  
Author(s):  
E. S. Nowak
Keyword(s):  
Water Vapor ◽  
Equation Of State ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Critical Point ◽  
Critical Region ◽  
Constant Pressure ◽  
Parametric Equation ◽  
Enthalpy And Entropy ◽  
Specific Volumes

A parametric equation of state was derived for water and water vapor in the critical region from experimental P-V-T data. It is valid in that part of the critical region encompassed by pressures from 3000 to 4000 psia, specific volumes from 0.0400 to 0.1100 ft3/lb, and temperatures from 698 to 752 deg F. The equation of state satisfies all of the known conditions at the critical point. It also satisfies the conditions along certain of the boundaries which probably separate “supercritical liquid” from “supercritical vapor.” The equation of state, though quite simple in form, is probably superior to any equation heretofore derived for water and water vapor in the critical region. Specifically, the deviations between the measured and computed values of pressure in the large majority of the cases were within three parts in one thousand. This coincides approximately with the overall uncertainty in P-V-T measurements. In view of these factors, the author recommends that the equation be used to derive values for such thermodynamic properties as specific heat at constant pressure, enthalpy, and entropy in the critical region.

Sign in / Sign up

Export Citation Format

Share Document