scholarly journals The formation of a structural framework in gelled Wyoming bentonite: Direct observation in aqueous solutions

2014 ◽  
Vol 435 ◽  
pp. 119-127 ◽  
Author(s):  
Marek S. Żbik ◽  
David J. Williams ◽  
Yen-Fang Song ◽  
Chun-Chieh Wang
2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Maria Ricci ◽  
William Trewby ◽  
Clodomiro Cafolla ◽  
Kislon Voïtchovsky

1976 ◽  
Vol 54 (2) ◽  
pp. 275-279 ◽  
Author(s):  
Frederick Peter Sargent ◽  
Edward Michael Gardy

It is shown that esolv, H•, and OH formed by the radiolysis of water by 3 MeV electrons are trapped by nitroso and nitrone compounds to give nitroxides with well defined esr spectra. Three spin trapping agents were used, nitroso-t-butane, phenyl-t-butyl nitrone, and 5,5′-dimethyl pyrroline-1-oxide. The latter was shown to be an excellent compound for these studies. Complications due to the instability of some of the nitroxides were overcome by coupling the electron accelerator to the esr spectrometer to permit direct observation of the spectra.


2011 ◽  
Vol 133 (8) ◽  
pp. 2444-2451 ◽  
Author(s):  
Detlef Schröder ◽  
Lucie Ducháčková ◽  
Ján Tarábek ◽  
Małgorzata Karwowska ◽  
Karol J. Fijalkowski ◽  
...  

Author(s):  
R. W. Anderson ◽  
D. L. Senecal

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.


Author(s):  
K. J. Böhm ◽  
a. E. Unger

During the last years it was shown that also by means of cryo-ultra-microtomy a good preservation of substructural details of biological material was possible. However the specimen generally was prefixed in these cases with aldehydes.Preparing ultrathin frozen sections of chemically non-prefixed material commonly was linked up to considerable technical and manual expense and the results were not always satisfying. Furthermore, it seems to be impossible to carry out cytochemical investigations by means of treating sections of unfixed biological material with aqueous solutions.We therefore tried to overcome these difficulties by preparing yeast cells (S. cerevisiae) in the following manner:


Author(s):  
John M. Wehrung ◽  
Richard J. Harniman

Water tables in aquifer regions of the southwest United States are dropping off at a rate which is greater than can be replaced by natural means. It is estimated that by 1985 wells will run dry in this region unless adequate artificial recharging can be accomplished. Recharging with surface water is limited by the plugging of permeable rock formations underground by clay particles and organic debris.A controlled study was initiated in which sand grains were used as the rock formation and water with known clay concentrations as the recharge media. The plugging mechanism was investigated by direct observation in the SEM of frozen hydrated sand samples from selected depths.


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