STUDY OF Y-Ba-Cu-O SUPERCONDUCTORS PREPARED WITH THE OXALATE PRECIPITATION/EVAPORATION METHOD

1990 ◽  
Vol 04 (19) ◽  
pp. 1237-1244 ◽  
Author(s):  
TH. LEVENTOURI ◽  
E. LIAROKAPIS ◽  
L. MARTINEZ ◽  
F.D. MEDINA ◽  
M. MORENO ◽  
...  

A study is presented on a series of Y-Ba-Cu-O superconductors prepared with the Oxalate Precipitation/Evaporation method. The effect of the preparation conditions on the properties of these superconductors has been studied with X-rays, scanning electron microscopy, Raman spectroscopy, and magnetic measurements. The experiments show that good quality superconductors can be fabricated with this preparation procedure and also indicate that the properties of these materials are very sensitive to the preparation conditions.

Author(s):  
M.G. Baldini ◽  
S. Morinaga ◽  
D. Minasian ◽  
R. Feder ◽  
D. Sayre ◽  
...  

Contact X-ray imaging is presently developing as an important imaging technique in cell biology. Our recent studies on human platelets have demonstrated that the cytoskeleton of these cells contains photondense structures which can preferentially be imaged by soft X-ray imaging. Our present research has dealt with platelet activation, i.e., the complex phenomena which precede platelet appregation and are associated with profound changes in platelet cytoskeleton. Human platelets suspended in plasma were used. Whole cell mounts were fixed and dehydrated, then exposed to a stationary source of soft X-rays as previously described. Developed replicas and respective grids were studied by scanning electron microscopy (SEM).


2014 ◽  
Vol 10 ◽  
pp. 1613-1619 ◽  
Author(s):  
Simon Rondeau-Gagné ◽  
Jules Roméo Néabo ◽  
Maxime Daigle ◽  
Katy Cantin ◽  
Jean-François Morin

The synthesis and self-assembly of two new phenylacetylene macrocycle (PAM) organogelators were performed. Polar 2-hydroxyethoxy side chains were incorporated in the inner part of the macrocycles to modify the assembly mode in the gel state. With this modification, it was possible to increase the reactivity of the macrocycles in the xerogel state to form polydiacetylenes (PDAs), leading to a significant enhancement of the polymerization yields. The organogels and the PDAs were characterized using Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM).


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