Study of iron-alumina cluster catalysts for synthesis of alkylaromatic hydrocarbons from CO and H2

1990 ◽  
Vol 57 (1-4) ◽  
pp. 1983-1986 ◽  
Author(s):  
Yu. V. Maksimov ◽  
V. V. Matveev ◽  
I. P. Suzdalev ◽  
M. V. Tsodikov ◽  
O. G. Ellert
Keyword(s):  
Alumina Cluster

scholarly journals Morphological Characteristics of Alumina Cluster Inclusions Acting as Precipitation Sites for MnS in Steel

2018 ◽  
Vol 82 (7) ◽  
pp. 223-231 ◽  
Author(s):  
Yoshiyuki Ueshima ◽  
Seiki Takebayashi ◽  
Ken-ichi Yamamoto ◽  
Masafumi Miyazaki ◽  
Kazumi Mizukami
Keyword(s):  
Morphological Characteristics ◽  
Alumina Cluster

scholarly journals From molecules to dust grains: The role of alumina cluster seeds

2019 ◽  
Vol 15 (S350) ◽  
pp. 245-248
Author(s):  
David Gobrecht ◽  
John M.C. Plane ◽  
Stefan T. Bromley ◽  
Leen Decin ◽  
Sergio Cristallo
Keyword(s):  
Bulk Material ◽  
Spectral Feature ◽  
Chemical Kinetic ◽  
Asymptotic Giant Branch ◽  
Nucleation Theory ◽  
Classical Nucleation Theory ◽  
Circumstellar Envelope ◽  
Agb Stars ◽  
Dust Grains ◽  
Alumina Cluster

AbstractAsymptotic Giant Branch (AGB) stars contribute a major part to the global dust budget in galaxies. Owing to their refractory nature alumina (stoichiometric formula AlO) is a promising candidate to be the first condensate emerging in the atmospheres of oxygen-rich AGB stars. Strong evidence for that is supplied by the presence of alumina in pristine meteorites and a broad spectral feature observed around ∼ 13 μm. The emergence of a specific condensate depends on the thermal stability of the solid, the gas density and its composition. The evaluation of the condensates is based on macroscopic bulk properties. The growth and size distribution of dust grains is commonly described by Classical Nucleation Theory (CNT). We question the applicability of CNT in an expanding circumstellar envelope as CNT presumes thermodynamic equilibrium and requires, in practise, seed nuclei on which material can condense. However, nano-sized molecular clusters differ significantly from bulk analogues. Quantum effects of the clusters lead to non-crystalline structures, whose characteristics (energy, geometry) differ substantially, compared to the bulk material. Hence, a kinetic quantum-chemical treatment involving various transition states describes dust nucleation most accurately. However, such a treatment is prohibitive for systems with more than 10 atoms. We discuss the viability of chemical-kinetic routes towards the formation of the monomer (Al2O3) and the dimer (Al4O6) of alumina.

Analysis of Influence of Aluminum Content on Inclusion Characteristic and Fatigue Life of Bearing Steel Using Statistics of Extreme Values

2014 ◽  
Vol 939 ◽  
pp. 11-18 ◽  
Author(s):  
Chin Chuan Hsu ◽  
Ho Hua Chung
Keyword(s):  
Fatigue Life ◽  
Nonmetallic Inclusion ◽  
Aluminum Content ◽  
Extreme Values ◽  
Energy Dispersive Spectrometer ◽  
Inclusion Size ◽  
Bearing Steel ◽  
Dominant Factor ◽  
Bearing Steels ◽  
Alumina Cluster

In this study, we predicted the maximum nonmetallic inclusion size of bearing steel using statistics of extreme values (SEV) approach, and discussed that the influence of aluminum content on the nonmetallic inclusion characteristic and fatigue life of bearing steel. The inclusion size and type was measured and identified by a scanning electron microscopy (SEM) and an energy dispersive spectrometer (EDS) respectively. The result shows that most inclusions in steels are oxysulfide and alumina cluster. A tendency was also found that the alumina size increases with increasing aluminum content, but the oxysulfide size almost remains unchanged. Furthermore, alumina clusters were formed in steel if more deoxidizer aluminum was added to the molten steel during metallurgical process. In addition, the fatigue life of steel is inversely proportional to alumina size, but it seems independent of oxysulfide size. Therefore, this study suggests that the dominant factor of influence on the fatigue life of bearing steel is alumina instead of oxysulfide. The results reported here would be beneficial to steel manufacturers attempting to improve the fatigue resistance of bearing steels.

scholarly journals On the Mechanisms of Alumina Cluster Formation in Molten Iron

1975 ◽  
Vol 15 (7) ◽  
pp. 371-379 ◽  
Author(s):  
Hiroshi OOI ◽  
Toshihiro SEKINE ◽  
Goro KASAI
Keyword(s):  
Cluster Formation ◽  
Molten Iron ◽  
Alumina Cluster

Hydration of Alumina Cluster Anions in the Gas Phase

2004 ◽  
Vol 126 (26) ◽  
pp. 8275-8283 ◽  
Author(s):  
Anita K. Gianotto ◽  
Jennifer W. Rawlinson ◽  
Kevin C. Cossel ◽  
John E. Olson ◽  
Anthony D. Appelhans ◽  
...  
Keyword(s):  
Gas Phase ◽  
Cluster Anions ◽  
Alumina Cluster

scholarly journals On the Mechanisms of Alumina Cluster Formation in Molten Iron

1973 ◽  
Vol 59 (8) ◽  
pp. 1078-1088 ◽  
Author(s):  
Hiroshi OOI ◽  
Minoru SEKINE ◽  
Goro KASAI
Keyword(s):  
Cluster Formation ◽  
Molten Iron ◽  
Alumina Cluster
Sign in / Sign up

Export Citation Format

Share Document