scholarly journals ADSORPTION OF YOUNG FISSION PRODUCTS ON VARIOUS SURFACES FROM NEUTRAL AND DILUTE ACID MEDIA: APPLICATION TO WATER SAMPLE COLLECTION FOR STEP PROGRAMS

1964 ◽  
Author(s):  
R. E. Foster ◽  
W. J. Maeck ◽  
J. E. Rein
Keyword(s):  
Water Sample ◽  
Fission Products ◽  
Dilute Acid ◽  
Sample Collection ◽  
Acid Media

The acid-catalyzed decomposition of nitramide

1996 ◽  
Vol 74 (10) ◽  
pp. 1779-1783 ◽  
Author(s):  
Robin A. Cox
Keyword(s):  
Rate Constants ◽  
Activation Parameters ◽  
Cyclic Process ◽  
Dilute Acid ◽  
Acid Media ◽  
Dilute Acid Solution ◽  
Acid Catalyzed ◽  
Reaction With Water ◽  
Hydrochloric And Sulfuric Acids ◽  
Good Agreement

Much attention has been paid to the base-catalyzed decomposition of nitramide, but despite this it was not certain that a corresponding acid-catalyzed reaction even existed before the work described in this paper. The excess acidity method has been applied to nitramide decomposition rate constants obtained in aqueous perchloric acid media, and to a lesser extent in aqueous hydrochloric and sulfuric acids. This analysis shows that the decomposition in dilute acid solution is actually a base-catalyzed reaction, with water acting as the base (perhaps in a cyclic process involving two water molecules), with rate constants in good agreement with previous estimates. However, in more concentrated acid media a true acid-catalyzed reaction can be dissected out. Activation parameters are given for both mechanisms, and it is shown that the acid-catalyzed process is similar to the acid-catalyzed decomposition of alkylnitramines. In sulfuric acid the reaction is slightly faster than it is in the other acids, due to the presence of a base-catalyzed process involving sulfate. Key words: nitramide, excess acidity, acid-catalyzed, base-catalyzed, kinetics.

scholarly journals Aged HCT-8 Cell Monolayers Support Cryptosporidium parvum Infection

2007 ◽  
Vol 73 (23) ◽  
pp. 7548-7551 ◽  
Author(s):  
Laura Y. Sifuentes ◽  
George D. Di Giovanni
Keyword(s):  
Water Quality ◽  
Cell Culture ◽  
Water Sample ◽  
Cryptosporidium Parvum ◽  
Water Samples ◽  
Sample Collection ◽  
Sample Processing ◽  
Cell Monolayers ◽  
Immunofluorescent Assay ◽  
Naturally Occurring

ABSTRACT Cell culture assays in various formats have been used to study the infectivity of Cryptosporidium spp. as well as to determine the infectivity of naturally occurring oocysts in water. Currently, cell culture assays for infectious Cryptosporidium spp. in water have largely been limited to practice in research laboratories. One obstacle to the routine use of Cryptosporidium cell culture assays for the analysis of water samples is the coordination of water sample collection and processing with readiness of cell culture monolayers. For most Cryptosporidium cell culture assays, monolayers are allowed to develop for 24 to 48 h to reach 80 to 100% confluence prior to inoculation. In this study, we used immunofluorescent assay microscopy to evaluate freshly confluent (2-day-old) and aged (8- to 67-day-old) HCT-8 cell monolayers for their ability to support Cryptosporidium parvum infection. HCT-8 monolayers as old as 67 days were clearly shown to support infection. In two of three experiments, aged monolayers (8- to 11-day-old and 11- to 22-day-old, respectively) developed the same number of C. parvum clusters of infection as freshly confluent monolayers. Results suggest that it may be possible to use cell monolayers from freshly confluent to 3 weeks old on hand for infectivity assays without having to schedule sample processing to coincide with development of freshly confluent monolayers. This would make Cryptosporidium cell culture assays much more feasible for water quality and utility laboratories.

Extraction of actinides and fission products by octyl(phenyl)-N,N-diisobutylcarbamoylmethyl-phosphine oxide from nitric acid media

Talanta ◽  
1992 ◽  
Vol 39 (5) ◽  
pp. 493-496 ◽  
Author(s):  
J.N. Mathur ◽  
M.S. Murali ◽  
P.R. Natarajan ◽  
L.P. Badheka ◽  
A. Banerji
Keyword(s):  
Nitric Acid ◽  
Phosphine Oxide ◽  
Fission Products ◽  
Acid Media
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