نتایج جستجو برای: 39 radon detectors
تعداد نتایج: 136608 فیلتر نتایج به سال:
The early Miocene Murree Formation, late Miocene Nagri Formation and recent alluvium rock units are exposed in the sub-Himalayas of the Bagh area, State of Azad Jammu and Kashmir, Pakistan. The Bagh area was badly affected by the Kashmir earthquake of October 8th 2005 which, along the Muzaffarabad Fault, deformed both the hanging and footwall blocks. The cracks, joints, fissures and fractures i...
BACKGROUND Underground miners exposed to high levels of radon have an excess risk of lung cancer. Residential exposure to radon is at much lower levels, and the risk of lung cancer with residential exposure is less clear. We conducted a systematic analysis of pooled data from all North American residential radon studies. METHODS The pooling project included original data from 7 North American...
In this paper, we propose and study a method using bare LR 115 SSNTDs for passive monitoring of the equilibrium factor F inside a radon exposure chamber. The method is based on the proxy equilibrium factor Fp which is defined as Fp 1⁄4 r=ðriC0tÞ 1, where ri is the partial sensitivity (i.e., the number of tracks per unit area per unit exposure), C0 is the radon gas concentration and t is the exp...
A rapidly growing United States data base consisting of over 90,000 indoor radon concentrations measured with passive integrating Track Etch detectors is described. The data base is subdivided by region and state, and a variety of s t a t i s t i c a l parameters summarizing the contents of the data base are presented for each geographical area. The primary conclusions that can be drawn are tha...
There are several methods of measuring radon concentrations but nuclear track detector cylindrical dosimeters are widely employed. In this investigation, the consequence of effective volumes of the dosimeters on the registration of alpha tracks in a CR-39 detector was studied. In a series of experiments an optimum radius for a CR-39-based open cylindrical radon dosimeter was found to be about 3...
background: radon concentration was measured in the soil and indoor of amman and al- rusaifa cities in jordan during summer season. materials and methods: the measurement was performed using time-integrated passive radon dosimeters, containing a solid state nuclear track plastic detector, commercially known as cr-39. results: radon concentration levels in the soil ranged from 2.8 ± 1.2 to 6.9 ±...
Solid-state nuclear track detectors (SSNTDs) in diffusion chambers have been routinely used for long-term measurements of radon gas concentrations. In usual practice, a filter is added across the top of the diffusion chamber to stop the progeny from entering. Thoron can also be deterred from entering the diffusion chamber by using a polyethylene (PE) membrane. However, the thickness of the PE m...
In the general population, evaluation of lung cancer risk from radon in houses is hampered by low levels of exposure and by dosimetric uncertainties due to residential mobility. To address these limitations, the authors conducted a case-control study in a predominantly rural area of China with low mobility and high radon levels. Included were all lung cancer cases diagnosed between January 1994...
The report summarizes recent research and practice of using materials with high absorption ability to noble gases to measure their radioactive isotopes. Most of the studies employ bisphenol-A based polycarbonates, because of their remarkably high absorption ability to noble gases. This is the material of which commercial CDs/DVDs are made and they may serve as serendipitous, already available i...
In a 1990-1996 case-control study in western Germany, the authors investigated lung cancer risk due to exposure to residential radon. Confirmed lung cancer cases from hospitals and a random sample of community controls were interviewed by trained interviewers regarding different risk factors. For 1 year, alpha track detectors were placed in dwellings to measure radon gas concentrations. The eva...
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