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Biomedical subjects

R L Fleischer

Publications and source records attributed to R L Fleischer.

16 recordsLinked to original sources
PubMed1992

Permeability of caulking compounds to 222Rn.

Caulking compounds have been tested as 222Rn barriers. Of these, the most effective is GE acrylic Latex Silicone Caulk, 0.2 cm of which attenuates 222Rn by 98% to 99.9%. The same thickness of two commercial 222Rn barriers attenuates radon by 75% to 90%. Permeabilities range from 0.3 to 140 x 10(-8) cm2 s-1.

Air Pollution, Indoor↗
PubMed1985

Field and laboratory tests of etched track detectors for 222Rn: summer-vs-winter variations and tightness effects in Maine houses.

Effects of tightness of homes and of bedrock character on indoor 222Rn concentrations were sought in 70 homes in the state of Maine by means of four 6- to 8-month-long surveys over a 1.5-yr period. Laboratory experiments were also performed that document the reliability of the track etching system used for the measurements. In this survey the Rn in tight homes was on the average 3.5 times that in drafty ones, and areas with granitic bedrock led to homes having 2.3 times the Rn as for homes on chlorite-biotite-rich bedrock. Winter-to-summer ratios ranged from 0.5-7, and averaged 1.5, implying that surveys of individual homes require a full year of monitoring.

Air Pollutants↗
PubMed1984

Passive measurement of working levels and effective diffusion constants of radon daughters by the nuclear track technique.

Measurements were made of working level ratios and the effective diffusion constants of radon daughters using a special housing designed to provide a uniform diffusional environment at the passive detectors. For 2 of 7 exposures, the measured scale of the diffusion was too large to satisfy the uniformity requirement. For the other 5, it was satisfied and reasonable working level ratios (WLR) were obtained. Such a housing could be used for extended area working level measurements but is too bulky to be suitable for personnel dosimetry. Personnel dosimetry could be done in mines using a passive area measurement of WLR combined with individual passive 222Rn measurements.

Bismuth↗
PubMed1984

Theory of passive measurement of radon daughters and working levels by the nuclear track technique.

A theoretical basis is described for long-term measurement of the activities of the alpha emitters in air by the track-etching technique. Inference of the other activities allows working levels to be derived. A set of absorber foils allows the differing response to alpha particles of different energies to be used to identify the relative abundance of the alpha emitters and the importance of diffusion to surfaces. The method is appropriate to measuring long-term exposures to radon atmospheres in homes or mines.

Air Pollutants↗