Results 241 to 250 of about 5,440,860 (285)

Factors Controlling Measurements of Radon Mass Exhalation Rate

Journal of Environmental Radioactivity, 2005
Radon mass exhalation rate of soil samples was measured using an exhalation chamber of 10 dm(3) volume and a Lucas cell. The results show that mass of sample, grain size and water content influence the radon mass exhalation rate. For soil of (226)Ra activity concentration about 2500 Bq kg(-1) and samples within the range from 0.20 kg to 0.50 kg, the ...
Chau Nguyen Dinh
exaly   +3 more sources

Thoron exhalation rates in areas of Japan

Radiation Protection Dosimetry, 2010
Thoron exhalation rates were measured with a newly made portable instrument at 33 areas in 7 prefectures of Japan. Thoron exhalation rates ranged from 49 to 4890 mBq m(-2) s(-1). Radon exhalation rates were also measured in many of the areas at the same time and ranged from 2.1 to 11 mBq m(-2) s(-1).
M, Shimo, Y, Ishimori, M, Hosoda, S, Tokonami   +3 more
openaire   +2 more sources

Diffusion Model of Radon Exhalation Rates

Health Physics, 1998
Radon migration through walls is considered using an effective diffusion model. One and two dimensional models as well as a spherical geometry are compared. It is concluded that either the 1-dimensional or spherical model, both having analytical solution, may be used for practical purposes. Application is made for typical cases in Athens, Greece.
M, Antonopoulos-Domis, P, Kritidis, C, Raptis   +2 more
openaire   +2 more sources

INFLUENCE OF THE POROSITY ON THE 222RN EXHALATION RATE OF CONCRETE

Health Physics, 2011
The composition of 23 concrete mixtures was varied in five separate series to evaluate the influence of porosity on the 222Rn exhalation rate. In each series, a range in porosities is obtained by varying (1) the amount of cement, (2) type of cement (Portland or blast furnace slag cement), (3) the amount of water at a fixed cement level, (4) addition of
Jong, P. de, Dijk, W. van, Rooij, M. de
openaire   +3 more sources

Influence of soil environmental parameters on thoron exhalation rate

Radiation Protection Dosimetry, 2010
Field measurements of thoron exhalation rates have been carried out using a ZnS(Ag) scintillation detector with an accumulation chamber. The influence of soil surface temperature and moisture saturation on the thoron exhalation rate was observed. When the variation of moisture saturation was small, the soil surface temperature appeared to induce a ...
M, Hosoda, S, Tokonami, A, Sorimachi, T, Ishikawa, S K, Sahoo, M, Furukawa, Y, Shiroma, Y, Yasuoka, M, Janik, N, Kavasi, S, Uchida, M, Shimo   +11 more
openaire   +2 more sources

Postprandial Changes in the Exhalation Rate of Radon Produced in Vivo

Science, 1978
The rate of exhalation of radon by persons with long-standing radium burdens increases about twofold shortly after a meal. The increase is short-lived and "normal" values are regained in 1.5 to 2 hours. The effect may account in part for the poor reproducibility in estimates of the freely emanating part of the radium content.
J, Rundo, F, Markun, J Y, Sha
openaire   +2 more sources

Radon Exhalation Rate from Various Building Materials

Health Physics, 1993
Solid-state alpha-track detectors using cellulose nitrate films were used to measure the radon exhalation rates from building materials. The radon flux emitted from the surface of the building material was measured by placing an inverted cup on the top of the building material. Cellulose nitrate film was placed within the cup.
C J, Chen, P S, Weng, T C, Chu
openaire   +2 more sources

Radon exhalation rate in building materials

International Journal of Radiation Applications and Instrumentation. Part D. Nuclear Tracks and Radiation Measurements, 1991
Radon is present in trace amounts almost everywhere on the earth, being distributed in the soil, the ground water and in the lower atmosphere. Radon can originate from a deeply burried deposit and can migrate to the surface of earth by diffusion and transport process.
A. Rawat, P.J. Jojo, A.J. Khan, R.K. Tyagi, Rajendra Prasad   +4 more
openaire   +1 more source

The Determination of Radon Exhalation Rates

Health Physics, 1983
The exhalation of radon from porous materials like mining wastes and building materials can be determined by studying the growth of radon activity in vessels containing samples of the materials. It is demonstrated that the initial part of the activity growth curve determines the total free exhalation rate of the sample used, independently of container ...
openaire   +2 more sources

In situ measurements of thoron exhalation rate in Okinawa, Japan

Radiation Protection Dosimetry, 2010
Thoron exhalation rates from the ground surface were measured at 57 sites on Okinawa Island, Japan, using a ZnS(Ag) scintillation detector equipped with photomultiplier. The arithmetic means ± SD, median ± SD, minimum and maximum of the rates (unit: Bq m(-2) s(-1)) were estimated to be 1.9 ± 1.4, 1.6 ± 0.3, 0.04 and 6.2, respectively.
Y, Shiroma, N, Isa, M, Hosoda, A, Sorimachi, T, Ishikawa, S, Tokonami, M, Furukawa   +6 more
openaire   +2 more sources