Sizing historical background

The committee s first priority was to answer the request of the Chief of Naval Operations to address the operational implications for naval forces of dealing with chemical and biological threats. After an executive summary, the first three chapters of the report focus on these issues. Historical background, discussion of the nature and size of the threat, and arguments for and against how seriously it should... 

To estimate a market would be no more than a guessing game since few applications at this time (1993) have reached the commercial stage and there is no historical background in patterns of growth and market size to buttress any predictions. 

Three reviews describing applications of diffusion denuders have been published. The doctoral dissertation of Ferm (31) reflects considerable experience with single-tube denuders for the measurement of a variety of species. The review by Ali et al. (32) is extensive it provides an excellent historical and theoretical background and summarizes the literature based on the type of analyte gas determined. The focus of the most recent review, by Cheng (19), is diffusion batteries used for size discrimination of aerosols as well as diffusion denuders. Various physical designs are discussed in some detail in that review. 

Historical data from the surrounding harbour indicated that species richness was typically above 30 taxa — a 10% reduction in the background species richness was permitted to compensate for differences in the sieve size used in this study (0.5 mm) versus historical investigations (0.3 mm). As a result, species richness values of less than 27 taxa were considered to indicate a moderate effect. Three stations demonstrated a reduction in benthic community diversity, with species richness values ranging from 7 to 20 taxa. All other stations had species richness values that were greater than 27. 

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