scholarly journals Phase Stability Diagrams for High Temperature Corrosion Processes

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
J. J. Ramos-Hernandez ◽  
J. Porcayo-Calderon ◽  
V. M. Salinas-Bravo ◽  
C. D. Arrieta-Gonzalez ◽  
J. G. Gonzalez-Rodriguez ◽  
...  
Keyword(s):  
High Temperature ◽  
Phase Stability ◽  
Fossil Fuels ◽  
Chemical Species ◽  
Data Bases ◽  
Fused Salts ◽  
Stability Diagrams ◽  
Different Types ◽  
Vanadium Salts ◽  
Engineering Alloys

Corrosion phenomena of metals by fused salts depend on chemical composition of the melt and environmental conditions of the system. Detail knowledge of chemistry and thermodynamic of aggressive species formed during the corrosion process is essential for a better understanding of materials degradation exposed to high temperature. When there is a lack of kinetic data for the corrosion processes, an alternative to understand the thermodynamic behavior of chemical species is to utilize phase stability diagrams. Nowadays, there are several specialized software programs to calculate phase stability diagrams. These programs are based on thermodynamics of chemical reactions. Using a thermodynamic data base allows the calculation of different types of phase diagrams. However, sometimes it is difficult to have access to such data bases. In this work, an alternative way to calculate phase stability diagrams is presented. The work is exemplified in the Na-V-S-O and Al-Na-V-S-O systems. This system was chosen because vanadium salts is one of the more aggressive system for all engineering alloys, especially in those processes where fossil fuels are used.

scholarly journals GERMINATION AND VIGOUR IN SEEDS OF THE COWPEA IN RESPONSE TO SALT AND HEAT STRESS

2019 ◽  
Vol 32 (1) ◽  
pp. 143-151 ◽  
Author(s):  
Luma Rayane de Lima Nunes ◽  
Paloma Rayane Pinheiro ◽  
Charles Lobo Pinheiro ◽  
Kelly Andressa Peres Lima ◽  
Alek Sandro Dutra
Keyword(s):  
Salt Stress ◽  
Heat Stress ◽  
High Temperature ◽  
Low Temperature ◽  
Vigna Unguiculata ◽  
Salt Concentration ◽  
Dry Weight ◽  
Germination Percentage ◽  
Different Types ◽  
Different Temperatures

ABSTRACT Salinity is prejudicial to plant development, causing different types of damage to species, or even between genotypes of the same species, with the effects being aggravated when combined with other types of stress, such as heat stress. The aim of this study was to evaluate the tolerance of cowpea genotypes (Vigna unguiculata L. Walp.) to salt stress at different temperatures. Seeds of the Pujante, Epace 10 and Marataoã genotypes were placed on paper rolls (Germitest®) moistened with different salt concentrations of 0.0 (control), 1.5, 3.0, 4.5 and 6.0 dS m-1, and placed in a germination chamber (BOD) at temperatures of 20, 25, 30 and 35°C. The experiment was conducted in a completely randomised design, in a 3 × 4 × 5 scheme of subdivided plots, with four replications per treatment. The variables under analysis were germination percentage, first germination count, shoot and root length, and total seedling dry weight. At temperatures of 30 and 35°C, increases in the salt concentration were more damaging to germination in the Epace 10 and Pujante genotypes, while for the Marataoã genotype, damage occurred at the temperature of 20°C. At 25°C, germination and vigour in the genotypes were higher, with the Pujante genotype proving to be more tolerant to salt stress, whereas Epace 10 and Marataoã were more tolerant to high temperatures. Germination in the cowpea genotypes was more sensitive to salt stress when subjected to heat stress caused by the low temperature of 20°C or high temperature of 35°C.

scholarly journals TiO2 Nanotubes Architectures for Solar Energy Conversion

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 931
Author(s):  
Yin Xu ◽  
Giovanni Zangari
Keyword(s):  
Solar Energy ◽  
Tio2 Nanotubes ◽  
Fossil Fuels ◽  
Photovoltaic Effect ◽  
Electric Energy ◽  
Chemical Species ◽  
Electrochemical Anodization ◽  
Science And Engineering ◽  
Electric Energy Storage ◽  
The Usa

Electromagnetic light from the Sun is the largest source, and the cleanest energy available to us; extensive efforts have been dedicated to developing science and engineering solutions in order to avoid the use of fossil fuels. Solar energy transforms photons into electricity via the photovoltaic effect, generating about 20 GW of energy in the USA in 2020, sufficient to power about 17 million households. However, sunlight is erratic, and technologies to store electric energy storage are unwieldy and relatively expensive. A better solution to store energy and to deliver this energy on demand is storage in chemical bonds: synthesizing fuels such as H2, methane, ethanol, and other chemical species. In this review paper we focus on titania (TiO2) nanotubes grown through electrochemical anodization and various modifications made to them to enhance conversion efficiency; these semiconductors will be used to implement the synthesis of H2 through water splitting. This document reviews selected research efforts on TiO2 that are ongoing in our group in the context of the current efforts worldwide. In addition, this manuscript is enriched by discussing the latest novelties in this field.

Textural and phase stability of CexZr1−xO2 mixed oxides under high temperature oxidising conditions

1999 ◽  
Vol 50 (2) ◽  
pp. 271-284 ◽  
Author(s):  
G Colón ◽  
F Valdivieso ◽  
M Pijolat ◽  
R.T Baker ◽  
J.J Calvino ◽  
...  
Keyword(s):  
High Temperature ◽  
Phase Stability ◽  
Mixed Oxides

Crystal structure, chemical expansion and phase stability of HoMnO3 at high temperature

2012 ◽  
Vol 196 ◽  
pp. 528-535 ◽  
Author(s):  
Sverre M. Selbach ◽  
Amund Nordli Løvik ◽  
Kristin Bergum ◽  
Julian R. Tolchard ◽  
Mari-Ann Einarsrud ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Phase Stability ◽  
Chemical Expansion

Development and Research of Copper Covering for Intensification of Cold Stamping of Products from Stainless Steels

2021 ◽  
Vol 316 ◽  
pp. 809-813
Author(s):  
Vladimir V. Karzhavin ◽  
Lev V. Maltsev ◽  
Viktoriya V. Bakina
Keyword(s):  
High Temperature ◽  
Acid Solution ◽  
Sulphuric Acid ◽  
Stainless Steels ◽  
Diffusion Zone ◽  
Pure Copper ◽  
Sulphuric Acid Solution ◽  
Fused Salts ◽  
Substitution Type ◽  
Cold Stamping

The copper covering put in fused salts of chlorides at temperature of 450-500cC and preventing scuffs on the surface of steel of type 12X18H10T at cold stamping of case products and fixture was investigated. Metallurgical surveys have shown: 1) except cover zone and zone of base metal there is also transition zone, representing substitution type of solution; 2) in the course of application there is superficial alloying, due to penetration of atoms of copper deep into metal and diffusions of doping steel elements in coating material under the influence of melts's high temperature. The schedule of change of concentration of copper in diffusion zone allows to conclude that the copper covering consists not of pure copper, and that the alloy contains only 94% of copper; other 6% represent the chrome and the titanium diffusing in copper covering. It is established also that, despite strong cohesion with basis, the covering is completely removed from surface of the stamping details being dissolved in standard sulphuric acid solution.

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