During the period April 1989 through December 1990, °3 concentrations in the marine boundary layer at Barbados, West Indies, show a pronounced seasonal cycle. Daily averaged values in the winter and spring often fall in the range of 25-35 ppbv for periods of several days, and they seldom fall below 20 ppbv. In contrast, during the summer, values typically fall in the range of 10-20 ppbv. During...

The relative differences in internal cation mobilities are measured for the molten systems (Li—Rb)N03 and (Li—Cs)N03 over a wide range of temperatures and concentrations with a countercurrent electromigration method, and the internal mobilities are calculated from these results and the available data on the electrical conductivity. The following phenomena are observed: (a) under some conditions...

Groundwater from remote parts of the Middle Rio Grande Basin in north-central New Mexico has perchlorate (ClO4-) concentrations of 0.12-1.8 micro/L. Because the water samples are mostly preanthropogenic in age (0-28000 years) and there are no industrial sources in the study area, a natural source of the ClO4- is likely. Most of the samples have Br-, Cl-, and SO4(2-) concentrations that are simi...

Two types of interaction of expanded porphyrins and nucleic acids are discussed. The first involves the specific chelation of the anionic phosphate diester backbone of DNA by the monoprotonated form of the water soluble sapphyrin 2. Support for the proposed binding mode derives from a variety of spectroscopic and biochemical studies, including visible absorption spectroscopy, circular dichroism...

polarographic method is considered as an alternative laboratory technique for analytical method in determination of dissolved oxygen and n-n03. analytical method is a time consuming technique and is subject to several interferences due to some of constituents in sewage. in this laboratory research, the polar graphic technique with, mercury drop electrodes and titrometric method were applied in ...

The objective of this research was to investigate the variation water quality parameters at different depths Gilgel Gibe I reservoir in Oromia Jimma zone during wet seasons. Five stations within were selected, and determined four (surface, 5 m, 10 15 m). Water analyzed on-site using a HACH, HQ40d portable multi-meter, turbidity measured Wag tech meter laboratory standard method. Comparison amon...

Enterococcus faecalis G1-0247 (vancomycin MIC, 16 microg/ml) was found to harbor a vanG operon 99% identical to the vanG operon in E. faecalis BM4518. E. faecalis N03-0233 (vancomycin MIC, 16 microg/ml) was found to harbor a novel vanG operon, vanG2, on an element in a different chromosomal location than the vanG-harboring elements in G1-0247 and BM4518.