Preface: recent advances in the in-situ characterization of heterogeneous catalysts

2010 ◽  
Vol 39 (12) ◽  
pp. 4557 ◽  
Author(s):  
Bert M. Weckhuysen
Keyword(s):  
Heterogeneous Catalysts ◽  
In Situ Characterization ◽  
Recent Advances

In Situ Characterization of Dynamic Changes in the Microstructure and Chemistry of Catalysts

2001 ◽  
Vol 7 (S2) ◽  
pp. 1058-1059
Author(s):  
P.A. Crozier
Keyword(s):  
Electron Microscopy ◽  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Catalytic Reactions ◽  
In Situ Characterization ◽  
Dynamic Changes ◽  
In Situ Electron Microscopy ◽  
Reactive Gas

Controlled atmosphere electron microscopy (CAEM) is a form of in situ microscopy in which the sample is exposed to a reactive gas during observation. This instrument essentially combines the nano-structural characterization features of a TEM with a microreactor and is ideal for studying gas/solid reactions in catalysts. Such in situ techniques can provide a link between surface studies performed under UHV conditions and catalytic reactions run in high-pressure reactors. with correctly designed experiments, CAEM is a powerful technique for correlating dynamic changes in microstructure with catalysis and can be used to provide insights on the location of active sites and mechanisms for catalysis. Baker and colleagues have worked for over thirty years on different heterogeneous catalysts using in situ electron microscopy (see [1] for example). Gai has also published many studies on the application of CAEM to oxide catalysts [2].The technique usually relies on detecting a change in the heterogeneous catalyst during a catalytic reaction.

Characterization of the glycoconjugates of boar testis and epididymis

Reproduction ◽  
2000 ◽  
pp. 325-335 ◽  
Author(s):  
A Calvo ◽  
LM Pastor ◽  
S Bonet ◽  
E Pinart ◽  
M Ventura
Keyword(s):  
Ricinus Communis ◽  
Lectin Histochemistry ◽  
Apical Part ◽  
Seminiferous Tubules ◽  
In Situ Characterization ◽  
Intense Staining ◽  
Terminal Galactose ◽  
Boar Spermatozoa

Lectin histochemistry was used to perform in situ characterization of the glycoconjugates present in boar testis and epididymis. Thirteen horseradish peroxidase- or digoxigenin-labelled lectins were used in samples obtained from healthy fertile boars. The acrosomes of the spermatids were stained intensely by lectins with affinity for galactose and N-acetyl-galactosamine residues, these being soybean, peanut and Ricinus communis agglutinins. Sertoli cells were stained selectively by Maackia ammurensis agglutinin. The lamina propria of seminiferous tubules showed the most intense staining with fucose-binding lectins. The Golgi area and the apical part of the principal cells of the epididymis were stained intensely with many lectins and their distribution was similar in the three zones of the epididymis. On the basis of lectin affinity, both testis and epididymis appear to have N- and O-linked glycoconjugates. Spermatozoa from different epididymal regions showed different expression of terminal galactose and N-acetyl-galactosamine. Sialic acid (specifically alpha2,3 neuraminic-5 acid) was probably incorporated into spermatozoa along the extratesticular ducts. These findings indicate that the development and maturation of boar spermatozoa are accompanied by changes in glycoconjugates. As some lectins stain cellular or extracellular compartments specifically, these lectins could be useful markers in histopathological evaluation of diseases of boar testis and epididymis.

In Situ Characterization of Soils for Prediction of Stress-Strain Relationship

1983 ◽  
Author(s):  
K. Arulanandan ◽  
Y. Dafalias ◽  
L. R. Herrmann ◽  
A. Anandarajah ◽  
N. Meegoda
Keyword(s):  
In Situ Characterization ◽  
Stress Strain ◽  
Strain Relationship
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