Sulphur solubility and sulphide immiscibility in silicate melts as a function of the concentration of manganese, nickel, tungsten and copper at 1 atm and 1400 °C

2008 ◽  
Vol 255 (1-2) ◽  
pp. 236-249 ◽  
Author(s):  
K.A. Evans ◽  
H. St. C. O'Neill ◽  
J.A. Mavrogenes
Keyword(s):  
Silicate Melts ◽  
Sulphide Immiscibility ◽  
Nickel Tungsten

CARPENTER AMS 5700

Alloy Digest ◽  
1975 ◽  
Vol 24 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Heat Treating ◽  
Temperature Performance ◽  
Technology Corporation ◽  
Valve Steel ◽  
Carpenter Technology Corporation ◽  
Exhaust Valves ◽  
Nickel Tungsten

Abstract CARPENTER AMS 5700 is an austenitic chromium-nickel-tungsten valve steel which offers good high-temperature properties and resistance to corrosion in exhaust valves. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fracture toughness and creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, and machining. Filing Code: SS-313. Producer or source: Carpenter Technology Corporation.

Hydrogenolytic cleavage of pyridine on different cobalt-molybdenum and nickel-tungsten catalysts

1981 ◽  
Vol 46 (6) ◽  
pp. 1348-1354 ◽  
Author(s):  
Mirko Černý ◽  
Miloš Kraus
Keyword(s):  
Reaction Products ◽  
Hydrogenation Activity ◽  
Catalyst Composition ◽  
Tungsten Catalysts ◽  
Nickel Tungsten ◽  
And Tungsten

Composition of the reaction products formed by hydrogenation of pyridine at 300 °C and 15 MPa in the presence of 15 sulphided and unsulphided molybdenum and tungsten catalysts promoted by cobalt and by nickel, respectively, using alumina as the support in most cases, has been examined. It has been proved that the catalyst composition affects both its hydrogenation activity and the ratio of transalkylation to cracking (or hydrocracking) reactions. Relations between the catalyst composition and its activity and selectivity found for the reaction of pyridine differ from those reported for hydrogenolytic cleavage of thiophene, hydrogenation and isomerization of cyclohexene.

Reinforced Polypyrrole with 2D Graphene Flakes Decorated with Interconnected Nickel-Tungsten Metal Oxide Complex Toward Superiorly Stable Supercapacitor

2021 ◽  
pp. 129396
Author(s):  
Seyyed Alireza Hashemi ◽  
Seyyed Mojtaba Mousavi ◽  
Hamid Reza Naderi ◽  
Sonia Bahrani ◽  
Mohammad Arjmand ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Graphene Flakes ◽  
Tungsten Metal ◽  
Nickel Tungsten

scholarly journals Chlorine as a Discriminant Element to Establish the Provenance of Central Mediterranean Obsidians

2020 ◽  
Vol 6 (1) ◽  
pp. 454-476
Author(s):  
Franco Foresta Martin ◽  
Silvio G. Rotolo ◽  
Manuela Nazzari ◽  
Maria Luisa Carapezza
Keyword(s):  
Electron Microprobe ◽  
Minor Element ◽  
Igneous Rocks ◽  
Chlorine Concentration ◽  
Silicate Melts ◽  
Alkali Content ◽  
Central Mediterranean ◽  
A Minor

Abstract Chlorine is a minor element present in obsidians in quantities greater than in average igneous rocks. The chlorine concentration in obsidians is generally low, of the order of tenths of wt %, but it exhibits an appreciable differentiation among geological sources. Despite these characteristics, chlorine has rarely been taken into consideration as a possible indicator of obsidian provenance and it does not appear in the chemical analytical tables accompanying the geochemical characterisation of obsidian samples. In this work, after an overview of chlorine geochemistry and cycle, we present thirty-one new electron microprobe (EPMA) analyses, including Cl, of geologic obsidians sampled from the four sources of the Central Mediterranean, exploited in prehistoric times (Monte Arci, Palmarola, Lipari and Pantelleria). The results are compared with 175 new EPMA analyses, including Cl, of archaeological obsidians already characterised in previous work and of known provenance. As such it was possible to ascertain that each source has a characteristic chlorine concentration, showing the utility of its use in the studies of obsidian provenance. Furthermore, given that the solubility of chlorine in silicate melts is correlated to its alkali content, in particular sodium, we assessed the efficacy of simple binary graphs Cl vs Na2O to better constrain the provenance of the obsidian samples.

scholarly journals Behavior and properties of water in silicate melts under deep mantle conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bijaya B. Karki ◽  
Dipta B. Ghosh ◽  
Shun-ichiro Karato
Keyword(s):  
Electrical Conductivity ◽  
Molar Volume ◽  
Water Solution ◽  
Pure Water ◽  
Electrical Conductance ◽  
Water Structure ◽  
Bulk Water ◽  
Silicate Melts ◽  
Pressure Regime ◽  
Low Pressures

AbstractWater (H2O) as one of the most abundant fluids present in Earth plays crucial role in the generation and transport of magmas in the interior. Though hydrous silicate melts have been studied extensively, the experimental data are confined to relatively low pressures and the computational results are still rare. Moreover, these studies imply large differences in the way water influences the physical properties of silicate magmas, such as density and electrical conductivity. Here, we investigate the equation of state, speciation, and transport properties of water dissolved in Mg1−xFexSiO3 and Mg2(1−x)Fe2xSiO4 melts (for x = 0 and 0.25) as well as in its bulk (pure) fluid state over the entire mantle pressure regime at 2000–4000 K using first-principles molecular dynamics. The simulation results allow us to constrain the partial molar volume of the water component in melts along with the molar volume of pure water. The predicted volume of silicate melt + water solution is negative at low pressures and becomes almost zero above 15 GPa. Consequently, the hydrous component tends to lower the melt density to similar extent over much of the mantle pressure regime irrespective of composition. Our results also show that hydrogen diffuses fast in silicate melts and enhances the melt electrical conductivity in a way that differs from electrical conduction in the bulk water. The speciation of the water component varies considerably from the bulk water structure as well. Water is dissolved in melts mostly as hydroxyls at low pressure and as –O–H–O–, –O–H–O–H– and other extended species with increasing pressure. On the other hand, the pure water behaves as a molecular fluid below 15 GPa, gradually becoming a dissociated fluid with further compression. On the basis of modeled density and conductivity results, we suggest that partial melts containing a few percent of water may be gravitationally trapped both above and below the upper mantle-transition region. Moreover, such hydrous melts can give rise to detectable electrical conductance by means of electromagnetic sounding observations.

scholarly journals Phase diagram of carbon-nickel-tungsten: A superatom model

2017 ◽  
Vol 1 (4) ◽  
Author(s):  
Sanxi Yao ◽  
Qin Gao ◽  
Michael Widom ◽  
Christopher Marvel ◽  
Martin Harmer
Keyword(s):  
Phase Diagram ◽  
Nickel Tungsten
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