Structural characterization of Brazilian niobium pentoxide and treatment to obtain the single phase (H-Nb2O5)

2021 ◽  
pp. 101015
Author(s):  
J.A. da Cruz ◽  
E.A. Volnistem ◽  
R.F. Ferreira ◽  
D.B. Freitas ◽  
A.J.M. Sales ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Single Phase ◽  
Niobium Pentoxide

Synthesis and Structural Characterization of Single-Phase BiFeO3Powders from a Polymeric Precursor

2007 ◽  
Vol 90 (9) ◽  
pp. 2723-2727 ◽  
Author(s):  
Monica Popa ◽  
Daniel Crespo ◽  
Jose M. Calderon-Moreno ◽  
Silviu Preda ◽  
Victor Fruth
Keyword(s):  
Structural Characterization ◽  
Single Phase ◽  
Polymeric Precursor

Structural characterization of sputtered single-phase γ‴ iron nitride coatings

2010 ◽  
Vol 518 (8) ◽  
pp. 1883-1891 ◽  
Author(s):  
I. Jouanny ◽  
P. Weisbecker ◽  
V. Demange ◽  
M. Grafouté ◽  
O. Peña ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Single Phase ◽  
Iron Nitride ◽  
Nitride Coatings

Structural characterization of polycrystalline (Nd,Al)-substituted zirconolite

2002 ◽  
Vol 757 ◽  
Author(s):  
Pascal Loiseau ◽  
Daniel Caurant ◽  
Noël Baffier ◽  
Catherine Fillet
Keyword(s):  
Structural Characterization ◽  
Single Phase ◽  
Rietveld Method ◽  
Structure Refinement ◽  
Significant Proportion ◽  
Optical Absorption Spectroscopy ◽  
Minor Actinides ◽  
X Ray

ABSTRACTZirconolite (formally CaZrTi2O7) is a crystalline phase particularly well adapted to actinide immobilization because of its excellent long-term behavior and its good containment capacity. Most of the French studies on zirconolite deal with minor actinides that are mainly responsible for the long-term radiotoxicity of high-level radioactive wastes. For these kind of studies, trivalent minor actinides (Am3+, Cm3+) can be simulated by a lanthanide ion with an ionic radius similar to that of Nd3+. Thus, several materials having the composition Ca1-xNdxZrTi2-xAlxO7 (0 ≤ x ≤ 0.8) were prepared by solid state reaction. These polycristalline materials were first characterized by X-ray diffraction and scanning electron microscopy associated with energy dispersive X-ray analysis in order to determine the nature of the crystalline phases formed. For low neodymium content (x ≤ 0.1), electron spin resonance of Nd3+ ions revealed that a significant proportion of these ions entered into trace amounts of perovskite. Nevertheless, all Ca1-xNdxZrTi2-xAlxO7 samples with x ≤ 0.6 can be considered as almost single phase zirconolite-2M. Structure refinement by the Rietveld method of Ca0.7Nd0.3ZrTi1.7Al0.3O7 showed that Nd3+ and Al3+ ions mainly entered respectively into the calcium site and into the split five-fold coordinated titanium site. Structural characterization of Ca0.3Nd0.7ZrTi1.3Al0.7O7 and Ca0.2Nd0.8ZrTi1.2Al0.8O7 samples confirmed that these compositions led to the crystallization of almost single phase zirconolite-3O, an orthorhombic polytype of zirconolite, whose structure was also refined by the Rietveld method. Results concerning neodymium location in Ca0.7Nd0.3ZrTi1.7Al0.3O7 and Ca0.3Nd0.7ZrTi1.3Al0.7O7 were qualitatively confirmed by optical absorption spectroscopy at low temperature.

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.

Structural characterization of the PPIase domain of FKBP51, a cochaperone of human Hsp90

2011 ◽  
Vol 44 (06) ◽  
Author(s):  
A Bracher ◽  
C Kozany ◽  
AK Thost ◽  
F Hausch
Keyword(s):  
Structural Characterization ◽  
Ppiase Domain

Structural characterization of dendrobine-type sesquiterpene alkaloids from the stems of Dendrobium nobile using LC-MS/MS

Planta Medica ◽  
2014 ◽  
Vol 80 (10) ◽  
Author(s):  
YH Wang ◽  
B Avula ◽  
N Abe ◽  
F Wei ◽  
M Wang ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Dendrobium Nobile
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