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E L FINCHER

Publications and source records attributed to E L FINCHER.

8 recordsLinked to original sources
PubMed1963

Adequate expression for average particle size of microbiological aerosols.

Attention was called to the fact that mathematical expressions exist for relating the various means commonly employed to describe the average particle size of microbiological aerosols. These include the count median diameter (CMD), the mass median diameter (MMD), the petri ratio (P(a)) size, and the settling rate (V(g)) size. It was pointed out that the diameters derived from the P(a) and V(g) are mathematically identical to the average surface-diameter (SMD), because this average is determined from the square of the diameters, a relationship which also describes the settling of particles by the Stokes equation. The useful equations are: log SMD = log CMD + 2.3026 log(2)sigma(g) and log MMD = log CMD + 6.9078 log(2)sigma(g) where sigma(g) is the standard geometric deviation, and the CMD is determined on a count basis and the MMD on a weight basis. It was suggested that the SMD is the most adequate expression for the average particle size of microbiological aerosols.

Aerosols↗
PubMed1962

Bacterial utilization of ether glycols.

A soil bacterium capable of using oligo- and polyethylene glycols and ether alcohols as sole sources of carbon for aerobic growth was isolated. The effects of substituent groups added to the ether bonds on the acceptability of the compounds as substrates were studied. Mechanisms for the incorporation of two-carbon compounds were demonstrated by the observation that acetate, glyoxylate, ethylene glycol, and a number of the tricarboxylic acid cycle intermediates served as growth substrates in minimal media. The rate of oxidation of the short-chained ethylene glycols by adapted resting cells varied directly with increasing numbers of two-carbon units in the chains from one to four. The amount of oxygen consumed per carbon atom of oligo- and polyethylene glycols was 100% of theoretical, but only 67% of theoretical for ethylene glycol. Resting cells oxidized oligo- and polyethylene glycols with 2 to 600 two-carbon units in the chains. Longer chained polyethylene glycols (up to 6,000) were oxidized at a very slow rate by these cells. Dehydrogenation of triethylene glycol by adapted cells was observed, coupling the reaction with methylene blue reduction.

Alcohols↗