Low-Lanthanide-Content CeO2/MgO Catalysts with Outstandingly Stable Oxygen Storage Capacities: An In-Depth Structural Characterization by Advanced STEM Techniques

ChemCatChem ◽  
2015 ◽  
Vol 7 (22) ◽  
pp. 3763-3778 ◽  
Author(s):  
Miguel Tinoco ◽  
Juan J. Sanchez ◽  
María P. Yeste ◽  
Miguel Lopez-Haro ◽  
Susana Trasobares ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Oxygen Storage ◽  
Stable Oxygen ◽  
Lanthanide Content

Preparation and Oxygen Intake/Release Characteristics of YBaCo2Fe2O7

2011 ◽  
Vol 306-307 ◽  
pp. 1520-1523
Author(s):  
Su Mei Zhang ◽  
Hong Zhang Song ◽  
Xin Hong Su ◽  
Jian Feng Jia ◽  
De Lin Yang ◽  
...  
Keyword(s):  
Oxygen Partial Pressure ◽  
Room Temperature ◽  
Raw Materials ◽  
The Other ◽  
Oxygen Storage ◽  
Partial Substitution ◽  
Oxygen Intake ◽  
Original Mass ◽  
Stable Oxygen ◽  
Lower Temperature

A novel compound YBaCo2Fe2O7 was synthesized successfully under low surrounding oxygen partial pressure by selecting raw materials Fe2O3 and Fe to fix the oxygen content to “O7” in YBaCo2Fe2O7. Its oxygen intake/release characteristics were investigated by the thermogravimetric (TG) analysis from room temperature to 1150°C. The YBaCo2Fe2O7 sample exhibits a weak oxygen intake capability at lower temperature 360°C. On the other hand, the oxygen intake/release cycles of YBaCo2Fe2O7 were investigated between 340°C and 410°C. The experimental results show that it has good and stable oxygen intake/release reproducibility, and that its mass change of oxygen reaches 0.6% of its original mass within 40 minutes. However, after partial substitution, the oxygen storage capability of YBaCo2Fe2O7 is worse than YBaCo4O7. The previous results mean that YBaCo2Fe2O7 is not enough as a novel candidate for oxygen storage or separation materials.

Phase behavior of cationic and anionic surfactants at low concentrations

1992 ◽  
Vol 50 (1) ◽  
pp. 694-695
Author(s):  
E. Naranjo
Keyword(s):  
Phase Behavior ◽  
Structural Characterization ◽  
Dynamic Systems ◽  
Anionic Surfactants ◽  
Intermolecular Forces ◽  
Stable Form ◽  
Surfactant Mixtures ◽  
Low Concentrations ◽  
Cationic And Anionic Surfactants ◽  
General Method

Equilibrium vesicles, those which are the stable form of aggregation and form spontaneously on mixing surfactant with water, have never been demonstrated in single component bilayers and only rarely in lipid or surfactant mixtures. Designing a simple and general method for producing spontaneous and stable vesicles depends on a better understanding of the thermodynamics of aggregation, the interplay of intermolecular forces in surfactants, and an efficient way of doing structural characterization in dynamic systems.

New ultrastructural findings about Borrelia burgdorferi by cryofixation, negative staining, thin sectioning and scanning techniques

1990 ◽  
Vol 48 (3) ◽  
pp. 582-583
Author(s):  
S. F. Hayes ◽  
M. D. Corwin ◽  
T. G. Schwan ◽  
D. W. Dorward ◽  
W. Burgdorfer
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Structural Characterization ◽  
Negative Staining ◽  
Low Speed ◽  
Thin Sectioning ◽  
Ultrastructural Findings

Characterization of Borrelia burgdorferi strains by means of negative staining EM has become an integral part of many studies related to the biology of the Lyme disease organism. However, relying solely upon negative staining to compare new isolates with prototype B31 or other borreliae is often unsatisfactory. To obtain more satisfactory results, we have relied upon a correlative approach encompassing a variety EM techniques, i.e., scanning for topographical features and cryotomy, negative staining and thin sectioning to provide a more complete structural characterization of B. burgdorferi.For characterization, isolates of B. burgdorferi were cultured in BSK II media from which they were removed by low speed centrifugation. The sedimented borrelia were carefully resuspended in stabilizing buffer so as to preserve their features for scanning and negative staining. Alternatively, others were prepared for conventional thin sectioning and for cryotomy using modified procedures. For thin sectioning, the fixative described by Ito, et al.

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