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Sample records for hierarchical discrete radon

  1. Discrete fractional Radon transforms and quadratic forms

    CERN Document Server

    Pierce, Lillian B

    2010-01-01

    We consider discrete analogues of fractional Radon transforms involving integration over paraboloids defined by positive definite quadratic forms. We prove sharp results for this class of discrete operators in all dimensions, providing necessary and sufficient conditions for them to extend to bounded operators from $\\ell^p$ to $\\ell^q$. The method involves an intricate spectral decomposition according to major and minor arcs, motivated by ideas from the circle method of Hardy and Littlewood. Techniques from harmonic analysis, in particular Fourier transform methods and oscillatory integrals, as well as the number theoretic structure of quadratic forms, exponential sums, and theta functions, play key roles in the proof.

  2. Analysis hierarchical model for discrete event systems

    Science.gov (United States)

    Ciortea, E. M.

    2015-11-01

    The This paper presents the hierarchical model based on discrete event network for robotic systems. Based on the hierarchical approach, Petri network is analysed as a network of the highest conceptual level and the lowest level of local control. For modelling and control of complex robotic systems using extended Petri nets. Such a system is structured, controlled and analysed in this paper by using Visual Object Net ++ package that is relatively simple and easy to use, and the results are shown as representations easy to interpret. The hierarchical structure of the robotic system is implemented on computers analysed using specialized programs. Implementation of hierarchical model discrete event systems, as a real-time operating system on a computer network connected via a serial bus is possible, where each computer is dedicated to local and Petri model of a subsystem global robotic system. Since Petri models are simplified to apply general computers, analysis, modelling, complex manufacturing systems control can be achieved using Petri nets. Discrete event systems is a pragmatic tool for modelling industrial systems. For system modelling using Petri nets because we have our system where discrete event. To highlight the auxiliary time Petri model using transport stream divided into hierarchical levels and sections are analysed successively. Proposed robotic system simulation using timed Petri, offers the opportunity to view the robotic time. Application of goods or robotic and transmission times obtained by measuring spot is obtained graphics showing the average time for transport activity, using the parameters sets of finished products. individually.

  3. Efficient blind image restoration using discrete periodic radon transform.

    Science.gov (United States)

    Lun, Daniel P K; Chan, Tommy C L; Hsung, Tai-Chiu; Feng, David Dagan; Chan, Yuk-Hee

    2004-02-01

    Restoring an image from its convolution with an unknown blur function is a well-known ill-posed problem in image processing. Many approaches have been proposed to solve the problem and they have shown to have good performance in identifying the blur function and restoring the original image. However, in actual implementation, various problems incurred due to the large data size and long computational time of these approaches are undesirable even with the current computing machines. In this paper, an efficient algorithm is proposed for blind image restoration based on the discrete periodic Radon transform (DPRT). With DPRT, the original two-dimensional blind image restoration problem is converted into one-dimensional ones, which greatly reduces the memory size and computational time required. Experimental results show that the resulting approach is faster in almost an order of magnitude as compared with the traditional approach, while the quality of the restored image is similar.

  4. Radon

    Science.gov (United States)

    Exposure to radon is the second leading cause of lung cancer after smoking. Radon is a colorless, odorless, tasteless and invisible gas produced by the decay of naturally occurring uranium in soil and water.

  5. Radon

    Science.gov (United States)

    ... can move to air, groundwater, and surface water. Radon-222 has a radioactive half-life of about 4 ... concerns. The main isotope of health concern is radon-222 ( 222 Rn). Many scientists believe that the alpha ...

  6. Focus measurement in 3D focal stack using direct and inverse discrete radon transform

    Science.gov (United States)

    Gómez-Cárdenes, Óscar; Marichal-Hernández, José G.; Trujillo-Sevilla, Juan M.; Carmona-Ballester, David; Rodríguez-Ramos, José M.

    2017-05-01

    The discrete Radon transform, DRT, calculates, with linearithmic complexity, the sum of pixels through a set of discrete lines covering all possible slopes and intercepts in an image. In 2006, a method was proposed to compute the inverse DRT that remains exact and fast, in spite of being iterative. In this work the DRT pair is used to propose a Ridgelet and a Curvelet transform that perform focus measurement of an image. Then the shape from focus approach based on DRT pair is applied to a focal stack to create a depth map of a scene.

  7. Hierarchical modeling of indoor radon concentration: how much do geology and building factors matter?

    Science.gov (United States)

    Borgoni, Riccardo; De Francesco, Davide; De Bartolo, Daniela; Tzavidis, Nikos

    2014-12-01

    Radon is a natural gas known to be the main contributor to natural background radiation exposure and only second to smoking as major leading cause of lung cancer. The main concern is in indoor environments where the gas tends to accumulate and can reach high concentrations. The primary contributor of this gas into the building is from the soil although architectonic characteristics, such as building materials, can largely affect concentration values. Understanding the factors affecting the concentration in dwellings and workplaces is important both in prevention, when the construction of a new building is being planned, and in mitigation when the amount of Radon detected inside a building is too high. In this paper we investigate how several factors, such as geologic typologies of the soil and a range of building characteristics, impact on indoor concentration focusing, in particular, on how concentration changes as a function of the floor level. Adopting a mixed effects model to account for the hierarchical nature of the data, we also quantify the extent to which such measurable factors manage to explain the variability of indoor radon concentration.

  8. Leveraging hierarchical population structure in discrete association studies.

    Directory of Open Access Journals (Sweden)

    Jonathan Carlson

    Full Text Available Population structure can confound the identification of correlations in biological data. Such confounding has been recognized in multiple biological disciplines, resulting in a disparate collection of proposed solutions. We examine several methods that correct for confounding on discrete data with hierarchical population structure and identify two distinct confounding processes, which we call coevolution and conditional influence. We describe these processes in terms of generative models and show that these generative models can be used to correct for the confounding effects. Finally, we apply the models to three applications: identification of escape mutations in HIV-1 in response to specific HLA-mediated immune pressure, prediction of coevolving residues in an HIV-1 peptide, and a search for genotypes that are associated with bacterial resistance traits in Arabidopsis thaliana. We show that coevolution is a better description of confounding in some applications and conditional influence is better in others. That is, we show that no single method is best for addressing all forms of confounding. Analysis tools based on these models are available on the internet as both web based applications and downloadable source code at http://atom.research.microsoft.com/bio/phylod.aspx.

  9. Robust Hydraulic Fracture Monitoring (HFM) of Multiple Time Overlapping Events Using a Generalized Discrete Radon Transform

    CERN Document Server

    Ely, Gregory

    2013-01-01

    In this work we propose a novel algorithm for multiple-event localization for Hydraulic Fracture Monitoring (HFM) through the exploitation of the sparsity of the observed seismic signal when represented in a basis consisting of space time propagators. We provide explicit construction of these propagators using a forward model for wave propagation which depends non-linearly on the problem parameters - the unknown source location and mechanism of fracture, time and extent of event, and the locations of the receivers. Under fairly general assumptions and an appropriate discretization of these parameters we first build an over-complete dictionary of generalized Radon propagators and assume that the data is well represented as a linear superposition of these propagators. Exploiting this structure we propose sparsity penalized algorithms and workflow for super-resolution extraction of time overlapping multiple seismic events from single well data.

  10. Continuous and discrete on-site detection of radon-222 in ground- and surface waters by means of an extraction module

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Axel [Helmholtz-Centre for Environmental Research-UFZ, Department of Analytical Chemistry, Permoserstrasse 15, 04318 Leipzig (Germany)], E-mail: axel.schmidt@ufz.de; Schlueter, Michael [Alfred Wegener Institute for Polar and Marine Research, Department of Marine Geochemistry, Bremerhaven (Germany); Melles, Martin [Institute of Geology and Mineralogy, University of Cologne, Cologne (Germany); Schubert, Michael [Helmholtz-Centre for Environmental Research-UFZ, Department of Analytical Chemistry, Permoserstrasse 15, 04318 Leipzig (Germany)

    2008-12-15

    A robust and straightforward method for on-site determination of radon-222 activity concentrations in water is presented. The methodical approach is based on the principle of liquid-gas-membrane extraction. An extraction module, which consists of hollow polypropylene fibres, allows radon stripping from the water of interest into a connected closed air-loop. The resulting radon-in-air activity concentration, which can easily be reconverted into the original radon-in-water activity concentration is measured by means of a standard mobile radon-in-air monitor. The experimental set-up allows radon detection in discrete water samples as well as continuous water pump streams. The technique, covering a wide activity concentration range, is in particular advantageous for measurements of radon-in-water in the field or on research cruises.

  11. Continuous and discrete on-site detection of radon-222 in ground- and surface waters by means of an extraction module.

    Science.gov (United States)

    Schmidt, Axel; Schlueter, Michael; Melles, Martin; Schubert, Michael

    2008-12-01

    A robust and straightforward method for on-site determination of radon-222 activity concentrations in water is presented. The methodical approach is based on the principle of liquid-gas-membrane extraction. An extraction module, which consists of hollow polypropylene fibres, allows radon stripping from the water of interest into a connected closed air-loop. The resulting radon-in-air activity concentration, which can easily be reconverted into the original radon-in-water activity concentration is measured by means of a standard mobile radon-in-air monitor. The experimental set-up allows radon detection in discrete water samples as well as continuous water pump streams. The technique, covering a wide activity concentration range, is in particular advantageous for measurements of radon-in-water in the field or on research cruises.

  12. Superfast algorithms of multidimensional discrete k-wave transforms and Volterra filtering based on superfast radon transform

    Science.gov (United States)

    Labunets, Valeri G.; Labunets-Rundblad, Ekaterina V.; Astola, Jaakko T.

    2001-12-01

    Fast algorithms for a wide class of non-separable n-dimensional (nD) discrete unitary K-transforms (DKT) are introduced. They need less 1D DKTs than in the case of the classical radix-2 FFT-type approach. The method utilizes a decomposition of the nD K-transform into the product of a new nD discrete Radon transform and of a set of parallel/independ 1D K-transforms. If the nD K-transform has a separable kernel (e.g., the case of the discrete Fourier transform) our approach leads to decrease of multiplicative complexity by the factor of n comparing to the classical row/column separable approach. It is well known that an n-th order Volterra filter of one dimensional signal can be evaluated by an appropriate nD linear convolution. This work describes new superfast algorithm for Volterra filtering. New approach is based on the superfast discrete Radon and Nussbaumer polynomial transforms.

  13. Fast and Scalable Computation of the Forward and Inverse Discrete Periodic Radon Transform.

    Science.gov (United States)

    Carranza, Cesar; Llamocca, Daniel; Pattichis, Marios

    2016-01-01

    The discrete periodic radon transform (DPRT) has extensively been used in applications that involve image reconstructions from projections. Beyond classic applications, the DPRT can also be used to compute fast convolutions that avoids the use of floating-point arithmetic associated with the use of the fast Fourier transform. Unfortunately, the use of the DPRT has been limited by the need to compute a large number of additions and the need for a large number of memory accesses. This paper introduces a fast and scalable approach for computing the forward and inverse DPRT that is based on the use of: a parallel array of fixed-point adder trees; circular shift registers to remove the need for accessing external memory components when selecting the input data for the adder trees; an image block-based approach to DPRT computation that can fit the proposed architecture to available resources; and fast transpositions that are computed in one or a few clock cycles that do not depend on the size of the input image. As a result, for an N × N image (N prime), the proposed approach can compute up to N(2) additions per clock cycle. Compared with the previous approaches, the scalable approach provides the fastest known implementations for different amounts of computational resources. For example, for a 251×251 image, for approximately 25% fewer flip-flops than required for a systolic implementation, we have that the scalable DPRT is computed 36 times faster. For the fastest case, we introduce optimized just 2N + ⌈log(2) N⌉ + 1 and 2N + 3 ⌈log(2) N⌉ + B + 2 cycles, architectures that can compute the DPRT and its inverse in respectively, where B is the number of bits used to represent each input pixel. On the other hand, the scalable DPRT approach requires more 1-b additions than for the systolic implementation and provides a tradeoff between speed and additional 1-b additions. All of the proposed DPRT architectures were implemented in VHSIC Hardware Description Language

  14. A campaign of discrete radon concentration measurements in soil of Niska Banja town, Serbia

    Energy Technology Data Exchange (ETDEWEB)

    Zunic, Z.S. [Institute of Nuclear Sciences ' Vinca' , ECE LAB, P.O. Box 522, 11001 Belgrade, Serbia (Serbia); Kozak, K. [Henryk Niewodniczanski Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, PL-31-342 Cracow (Poland)], E-mail: Krzysztof.Kozak@ifj.edu.pl; Ciotoli, G. [Department of Earth Sciences, University of Rome ' La Sapienza' , Piazzale A. Moro, 5-00185 Rome (Italy); Ramola, R.C. [Department of Physics, H.N.B. Garhwal University, Badshahi Thaul Campus, Tehri Garhwal 249 199 (India); Kochowska, E. [Henryk Niewodniczanski Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, PL-31-342 Cracow (Poland); Ujic, P.; Celikovic, I. [Institute of Nuclear Sciences ' Vinca' , ECE LAB, P.O. Box 522, 11001 Belgrade (Serbia); Mazur, J.; Janik, M. [Henryk Niewodniczanski Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, PL-31-342 Cracow (Poland); Demajo, A. [Institute of Nuclear Sciences ' Vinca' , ECE LAB, P.O. Box 522, 11001 Belgrade (Serbia); Birovljev, A. [RADONLAB, Forskningsveien 3 B, 0373 Oslo (Norway); Bochicchio, F. [Italian National Institute of Health, Department of Technology and Health, Unit of Radioactivity and Related Health Effects, Viale Regina Elena 299, 00161 Rome (Italy); Yarmoshenko, I.V. [Radiation Laboratory Institute of Industrial Ecology, Ural Branch of Russian Academy of Sciences, 20A S. Kovalevskoy Street, Ekaterinburg 620219 (Russian Federation); Kryeziu, D. [Low-level Counting Laboratory, Faradaygasse 3, Arsenal Objekt 214, A-1030 Vienna (Austria); Olko, P. [Henryk Niewodniczanski Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, PL-31-342 Cracow (Poland)

    2007-11-15

    The first radon soil gas survey in Serbia, using passive detectors (SSNTD, CR-39), was carried out in June 2005 at field sites in Niska Banja town. The aim of the survey was to identify risk zones characterised by high levels of this radioactive gas. Radon measurements were made at the depth of 50 cm, in the ground according to a systematic grid pattern. Furthermore, at all 48 measurement points, the surface gamma dose rates in the air was also measured at the same locations and soil samples were collected for gamma spectrometric analysis for the radionuclides {sup 226}Ra, {sup 228}Th and {sup 40}K. Radon concentrations were found to range from 1270 to 155000Bqm{sup -3} with an average of 33765Bqm{sup -3} and a median value of 12626Bqm{sup -3}. The geometrical mean value and geometrical standard deviation were calculated as 16160Bqm{sup -3} and 3.5Bqm{sup -3}, respectively. Gamma dose rate varies from 92 to 316nGyh{sup -1}, with an average of 132nGyh{sup -1}. The radium content in collected soil samples ranges from 24 to 1810Bqkg{sup -1} with an average of 187Bqkg{sup -1}. High correlations (r{sup 2}>0.8) between soil gas radon concentration, gamma dose rate and {sup 226}Ra content in soil were found for each pair. The distribution of radon concentrations in soil gas shows bimodal shape.

  15. Enhancing the Discrete Particle Swarm Optimization based Workflow Grid Scheduling using Hierarchical Structure

    Directory of Open Access Journals (Sweden)

    Ritu Garg

    2013-05-01

    Full Text Available The problem of scheduling dependent tasks (DAG is an important version of scheduling, to efficiently exploit the computational capabilities of grid systems. The problem of scheduling tasks of a graph onto a set of different machines is an NP Complete problem. As a result, a number of heuristic and meta-heuristic approaches are used over the years due to their ability of providing high quality solutions with reasonable computation time. Discrete Particle Swarm Optimization is one such meta-heuristic used for solving the discrete problem of grid scheduling, but this method converge to sub optimal solutions due to premature convergence. To deal with premature convergence, in this paper we proposed the design and implementation of hierarchical discrete particle swarm optimization (H-DPSO for dependent task scheduling in grid environment. In H-DPSO particles are arranged in dynamic hierarchy where good particles lying above in hierarchy are having larger influence on the swarm. We consider the bi-objective version of problem to minimize makespan and total cost simultaneously as the optimization criteria. The H-DPSO based scheduler was evaluated under different application task graphs. Simulation analysis manifests that H-DPSO based scheduling is highly viable and effective approach for grid computing.

  16. Discrete and Continuous Optimization Based on Hierarchical Artificial Bee Colony Optimizer

    Directory of Open Access Journals (Sweden)

    Lianbo Ma

    2014-01-01

    Full Text Available This paper presents a novel optimization algorithm, namely, hierarchical artificial bee colony optimization (HABC, to tackle complex high-dimensional problems. In the proposed multilevel model, the higher-level species can be aggregated by the subpopulations from lower level. In the bottom level, each subpopulation employing the canonical ABC method searches the part-dimensional optimum in parallel, which can be constructed into a complete solution for the upper level. At the same time, the comprehensive learning method with crossover and mutation operator is applied to enhance the global search ability between species. Experiments are conducted on a set of 20 continuous and discrete benchmark problems. The experimental results demonstrate remarkable performance of the HABC algorithm when compared with other six evolutionary algorithms.

  17. Higher order hierarchical discretization scheme for surface integral equations for layered media

    DEFF Research Database (Denmark)

    Jørgensen, Erik; Kim, Oleksiy S.; Meincke, Peter;

    2004-01-01

    equation. This higher order MoM solution comprises higher order curved patches for the geometry modeling and higher order hierarchical basis functions for expansion of the electric surface current density. Due to the hierarchical property of the basis functions, the order of the expansion can be selected...

  18. Radon metrology

    Energy Technology Data Exchange (ETDEWEB)

    Naismith, S.; Howarth, C. [National Radiological Protection Board, Chilton (United Kingdom)

    1996-09-01

    NRPB carries out calibrations of various types of radon and radon decay product measurement systems for its own purposes and for laboratories throughout Europe. There are currently two radon calibration facilities at NRPB: a 43 m{sup 3} radon chamber and the Fast Radon Exposure Device (FRED), a sealed steel drum. The radon chamber is used for active radon detection systems and the calibration of large numbers of passive detectors. Fred has a high radon concentration and is used to calibrate small numbers of passive radon gas detectors in a short period. (Author).

  19. A Framework for Land Cover Classification Using Discrete Return LiDAR Data: Adopting Pseudo-Waveform and Hierarchical Segmentation

    Science.gov (United States)

    Jung, Jinha; Pasolli, Edoardo; Prasad, Saurabh; Tilton, James C.; Crawford, Melba M.

    2014-01-01

    Acquiring current, accurate land-use information is critical for monitoring and understanding the impact of anthropogenic activities on natural environments.Remote sensing technologies are of increasing importance because of their capability to acquire information for large areas in a timely manner, enabling decision makers to be more effective in complex environments. Although optical imagery has demonstrated to be successful for land cover classification, active sensors, such as light detection and ranging (LiDAR), have distinct capabilities that can be exploited to improve classification results. However, utilization of LiDAR data for land cover classification has not been fully exploited. Moreover, spatial-spectral classification has recently gained significant attention since classification accuracy can be improved by extracting additional information from the neighboring pixels. Although spatial information has been widely used for spectral data, less attention has been given to LiDARdata. In this work, a new framework for land cover classification using discrete return LiDAR data is proposed. Pseudo-waveforms are generated from the LiDAR data and processed by hierarchical segmentation. Spatial featuresare extracted in a region-based way using a new unsupervised strategy for multiple pruning of the segmentation hierarchy. The proposed framework is validated experimentally on a real dataset acquired in an urban area. Better classification results are exhibited by the proposed framework compared to the cases in which basic LiDAR products such as digital surface model and intensity image are used. Moreover, the proposed region-based feature extraction strategy results in improved classification accuracies in comparison with a more traditional window-based approach.

  20. Scopingsreport Radon

    NARCIS (Netherlands)

    Blaauboer RO; Vaas LH; Hesse JM; Slooff W

    1989-01-01

    Dit scopingsrapport vormt een onderdeel van de voorbereiding tot het opstellen van het basisdocument radon. Het doel van dit rapport is het algemene kennisniveau van de deelnemers aan de scopingsbijeenkomst aangaande radon op eenzelfde peil te brengen en discussie- en beslispunten inzake de inho

  1. Scopingsreport Radon

    NARCIS (Netherlands)

    Blaauboer RO; Vaas LH; Hesse JM; Slooff W

    1989-01-01

    Dit scopingsrapport vormt een onderdeel van de voorbereiding tot het opstellen van het basisdocument radon. Het doel van dit rapport is het algemene kennisniveau van de deelnemers aan de scopingsbijeenkomst aangaande radon op eenzelfde peil te brengen en discussie- en beslispunten inzake de inho

  2. Methodology developed to make the Quebec indoor radon potential map.

    Science.gov (United States)

    Drolet, Jean-Philippe; Martel, Richard; Poulin, Patrick; Dessau, Jean-Claude

    2014-03-01

    This paper presents a relevant approach to predict the indoor radon potential based on the combination of the radiogeochemical data and the indoor radon measurements in the Quebec province territory (Canada). The Quebec ministry of health asked for such a map to identify the radon-prone areas to manage the risk for the population related to indoor radon exposure. Three radiogeochemical criteria including (1) equivalent uranium (eU) concentration from airborne surface gamma-ray surveys, (2) uranium concentration measurements in sediments, (3) bedrock and surficial geology were combined with 3082 basement radon concentration measurements to identify the radon-prone areas. It was shown that it is possible to determine thresholds for the three criteria that implied statistically significant different levels of radon potential using Kruskal-Wallis one way analyses of variance by ranks. The three discretized radiogeochemical datasets were combined into a total predicted radon potential that sampled 98% of the studied area. The combination process was also based on Kruskal-Wallis one way ANOVA. Four statistically significant different predicted radon potential levels were created: low, medium, high and very high. Respectively 10 and 13% of the dwellings exceed the Canadian radon guideline of 200 Bq/m(3) in low and medium predicted radon potentials. These proportions rise up to 22 and 45% respectively for high and very high predicted radon potentials. This predictive map of indoor radon potential based on the radiogeochemical data was validated using a map of confirmed radon exposure in homes based on the basement radon measurements. It was shown that the map of predicted radon potential based on the radiogeochemical data was reliable to identify radon-prone areas even in zones where no indoor radon measurement exists.

  3. Methodology developed to make the Quebec indoor radon potential map

    Energy Technology Data Exchange (ETDEWEB)

    Drolet, Jean-Philippe, E-mail: jean-philippe.drolet@ete.inrs.ca [Institut national de la recherche scientifique, Eau Terre Environnement Research Centre (ETE-INRS), 490 de la Couronne, G1K 9A9 Quebec (Canada); Martel, Richard [Institut national de la recherche scientifique, Eau Terre Environnement Research Centre (ETE-INRS), 490 de la Couronne, G1K 9A9 Quebec (Canada); Poulin, Patrick [Institut national de santé publique du Québec (INSPQ), 945 avenue Wolfe, G1V 5B3 Quebec (Canada); Dessau, Jean-Claude [Agence de la santé et des services sociaux des Laurentides, 1000 rue Labelle, J7Z 5 N6 Saint-Jérome (Canada)

    2014-03-01

    This paper presents a relevant approach to predict the indoor radon potential based on the combination of the radiogeochemical data and the indoor radon measurements in the Quebec province territory (Canada). The Quebec ministry of health asked for such a map to identify the radon-prone areas to manage the risk for the population related to indoor radon exposure. Three radiogeochemical criteria including (1) equivalent uranium (eU) concentration from airborne surface gamma-ray surveys, (2) uranium concentration measurements in sediments, (3) bedrock and surficial geology were combined with 3082 basement radon concentration measurements to identify the radon-prone areas. It was shown that it is possible to determine thresholds for the three criteria that implied statistically significant different levels of radon potential using Kruskal–Wallis one way analyses of variance by ranks. The three discretized radiogeochemical datasets were combined into a total predicted radon potential that sampled 98% of the studied area. The combination process was also based on Kruskal–Wallis one way ANOVA. Four statistically significant different predicted radon potential levels were created: low, medium, high and very high. Respectively 10 and 13% of the dwellings exceed the Canadian radon guideline of 200 Bq/m{sup 3} in low and medium predicted radon potentials. These proportions rise up to 22 and 45% respectively for high and very high predicted radon potentials. This predictive map of indoor radon potential based on the radiogeochemical data was validated using a map of confirmed radon exposure in homes based on the basement radon measurements. It was shown that the map of predicted radon potential based on the radiogeochemical data was reliable to identify radon-prone areas even in zones where no indoor radon measurement exists. - Highlights: • 5 radiogeochemical datasets were used to map the geogenic indoor radon potential. • An indoor radon potential was determined for

  4. Intraclass Correlation Coefficients in Hierarchical Design Studies with Discrete Response Variables: A Note on a Direct Interval Estimation Procedure

    Science.gov (United States)

    Raykov, Tenko; Marcoulides, George A.

    2015-01-01

    A latent variable modeling procedure that can be used to evaluate intraclass correlation coefficients in two-level settings with discrete response variables is discussed. The approach is readily applied when the purpose is to furnish confidence intervals at prespecified confidence levels for these coefficients in setups with binary or ordinal…

  5. Workshop on dosimetry for radon and radon daughters

    Energy Technology Data Exchange (ETDEWEB)

    Turner, J.E.; Holoway, C.F.; Loebl, A.S. (eds.)

    1978-05-01

    Emphasis is placed on the dosimetry for radon and daughters, rather than on monitoring and instrumentation. The objectives of the meeting were to exchange scientific information, to identify problem areas in radon-daughter dosimetry, and to make any observations or recommendations by the participants through issuance of this report. The discussion topics included the history of dosimetry for radon and daughters, human data, aerosols, deposition and movement in the respiratory tract, dose calculations, dose-to-working-level-month (WLM) conversion factors, animal experiments, and the development of regulations and remedial criteria for reducing population exposures to radon daughters. This report contains a summary of Workshop discussions plus individual statements contributed by several of the participants. The outstanding problem areas from the standpoint of dosimetry appear to involve the appropriate lung organ mass to be used (average lung-tissue dose vs. high-level local dose); recognition of the discrete, rather than continuous, structure of the mucus; lack of knowledge about lung clearance; the variability of dose with the degree of disequilibrium and the unattached fraction of radon daughters for a given WLM; and questions about the character of uranium mine atmospheres actually breathed in the older mines from which much of the epidemiological information originates. The development of criteria for taking remedial action to reduce exposures involves additional concerns of basing long-term risk assessment on short-term sampling and applying WLM data for miners to general populations.

  6. Managing Radon in Schools

    Science.gov (United States)

    EPA recommends testing all schools for radon. As part of an effective IAQ management program, schools can take simple steps to test for radon and reduce risks to occupants if high radon levels are found.

  7. The discrete Feynman integral

    NARCIS (Netherlands)

    Dorlas, T. C.; Thomas, E. G. F.

    2008-01-01

    We construct a genuine Radon measure with values in B(l(2)(Z(d))) on the set of paths in Z(d) representing Feynman's integral for the discrete Laplacian on l(2)(Z(d)), and we prove the Feynman integral formula for the solutions of the Schrodinger equation with Hamiltonian H=-1/2 Delta+ V, where Delt

  8. 《离散数学》分层次教学的实践与探索%Practice and Exploration on Hierarchical Teaching in Discrete Mathematics

    Institute of Scientific and Technical Information of China (English)

    闫巧

    2012-01-01

    Introduces the hierarchical teaching methods in Discrete Mathematics based on principle of individualized, which are used in college of computer science and software engineering in Shenzhen University. Through the use of Chinese teaching, Bilingual teaching and English teaching, the methods can make students who have different base and different targets acquire great improvement in the learning process. The methods are beneficial to speeding up internationalization process of higher education in Shenzhen University and helping to train the students with an international perspective.%介绍深圳大学计算机与软件学院在《离散数学》教学中基于因材施教原则所采用的分层次教学方法,通过使用中文教学、双语教学、全英文教学三种不同的施教方法,使得不同基础和不同目标的学生在学习过程中都获得较大提高.而且利于深圳大学尽快融入高等教育国际化进程当中,培养更多具国际视野的复合型人才。

  9. Algorithm for solving of two-level hierarchical minimax program control problem in discrete-time dynamical system with incomplete information

    Science.gov (United States)

    Shorikov, A. F.

    2016-12-01

    This article discusses the discrete-time dynamical system consisting from two controlled objects and described by a linear recurrent vector equations in the presence of uncertain perturbations. This dynamical system has two levels of a control: dominant level (the first level or the level I) and subordinate level (the second level or the level II) and both have different linear terminal criterions of functioning and united a priori by determined information and control connections. It is assumed that the sets constraining all a priori undefined parameters are known and they are a finite sets or convex, closed and bounded polyhedrons in the corresponding finite-dimensional vector spaces. For the dynamical system in question, we propose a mathematical formalization in the form of solving two-level hierarchical minimax program control problem with incomplete information. In this article for solving of the investigated problem is proposed the algorithm that has a form of a recurrent procedure of solving a linear programming and a finite optimization problems. The results obtained in this article can be used for computer simulation of an actual dynamical processes and for designing controlling and navigation systems.

  10. Discrete Topology Based Hierarchical Segmentation for Efficient Object-Based Image Analyis: Application to Object Detection in High Resolution Satellite Images

    Science.gov (United States)

    Syed, A. H.; Saber, E.; Messinger, D.

    2013-05-01

    With rapid developments in satellite and sensor technologies, there has been a dramatic increase in the availability of high resolution (HR) remotely sensed images. Hence, the ability to collect images remotely is expected to far exceed our capacity to analyse these images manually. Consequently, techniques that can handle large volumes of data are urgently needed. In many of today's multiscale techniques the underlying representation of objects is still pixel-based, i.e. object entities are still described/accessed via pixelbased descriptors, thereby creating a bottleneck when processing large volumes of data. Also, these techniques do not yet leverage the topological and contextual information present in the image. We propose a framework for Discrete Topology based hierarchical segmentation, addressing both the algorithms and data structures that will be required. The framework consists of three components: 1) Conversion to dart-based representation, 2) Size-Constrained-Region Merging to generate multiple segmentations, and 3) Update of two sparse arrays SIGMA and LAMBDA which together encode the topology of each region in the hierarchy. The results of our representation are demonstrated both on a synthetic and a real high resolution images. Application of this representation to objectdetection is also discussed.

  11. Radon Guide for Tenants

    Science.gov (United States)

    This guide is for people who rent their apartments or houses. The guide explains what radon is, and how to find out if there is a radon problem in your home. The guide also talks about what you can do if there are high radon levels in your home.

  12. Health Risk of Radon

    Science.gov (United States)

    ... Radon in Homes EPA 402-R-03-003. Summary Fact Sheet on the updated risk assessment . Top of Page Former U.S. Surgeon General ... WHO) launched an international radon project to help countries increase ... reduce radon-related risks. The U.S. EPA is one of several government ...

  13. The generalized radon transform: Sampling, accuracy and memoryconsiderations

    Energy Technology Data Exchange (ETDEWEB)

    Luengo Hendriks, Cris L.; van Ginkel, Michael; Verbeek, Piet W.; van Vliet, Lucas J.

    2004-09-23

    The generalized Radon (or Hough) transform is a well-known tool for detecting parameterized shapes in an image. The Radon transform is a mapping between the image space and a parameter space. The coordinates of a point in the latter correspond to the parameters of a shape in the image. The amplitude at that point corresponds to the amount of evidence for that shape. In this paper we discuss three important aspects of the Radon transform. The first aspect is discretization. Using concepts from sampling theory we derive a set of sampling criteria for the generalized Radon transform. The second aspect is accuracy. For the specific case of the Radon transform for spheres, we examine how well the location of the maxima matches the true parameters. We derive a correction term to reduce the bias in the estimated radii. The third aspect concerns a projection-based algorithm to reduce memory requirements.

  14. Least-squares reverse time migration with radon preconditioning

    KAUST Repository

    Dutta, Gaurav

    2016-09-06

    We present a least-squares reverse time migration (LSRTM) method using Radon preconditioning to regularize noisy or severely undersampled data. A high resolution local radon transform is used as a change of basis for the reflectivity and sparseness constraints are applied to the inverted reflectivity in the transform domain. This reflects the prior that for each location of the subsurface the number of geological dips is limited. The forward and the adjoint mapping of the reflectivity to the local Radon domain and back are done through 3D Fourier-based discrete Radon transform operators. The sparseness is enforced by applying weights to the Radon domain components which either vary with the amplitudes of the local dips or are thresholded at given quantiles. Numerical tests on synthetic and field data validate the effectiveness of the proposed approach in producing images with improved SNR and reduced aliasing artifacts when compared with standard RTM or LSRTM.

  15. The radon indicator

    Science.gov (United States)

    Samuelsson, L.

    2005-11-01

    The radon indicator is an efficient instrument for measuring the radon daughter concentrations in a house or dwelling. Physics or environmental science students could build a radon indicator as a student project. Another possibility would be to use a radon indicator in a student investigation of radon levels in different houses. Finally the radon indicator is an excellent device for producing a radioactive source, free of charge, for the study of α-, β- and γ-radiation. The half-life of the activity collected is approximately 40 min. The radon indicator makes use of an electrostatic method by which charged particles are drawn to a small aluminium plate with a high negative voltage (-5 kV), thus creating a strong electric field between the plate and a surrounding copper wire. The radioactivity on the plate is subsequently measured by a GM-counter and the result calculated in Bq m-3. The collecting time is just 5.5 min and therefore the instrument is only suitable for use in a short-time method for indicating the radon concentration. An improved diagram, ground-radon and/or wall-radon in houses, is presented on the basis of the author's measurements recorded with the radon indicator over many years. This diagram is very useful when discussing how to reduce radiation levels in homes.

  16. Indoor radon; Le radon dans les batiments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    The radon, a natural radioactive gas, is present almost everywhere on the earth's surface. It can be accumulated at high concentration in confined spaces (buildings, mines, etc). In the last decades many studies conducted in several countries showed that inhaling important amounts of radon rises the risk of lung cancer. Although, the radon is a naturally appearing radioactive source, it may be the subject of a human 'enhancement' of concentration. The increasing radon concentration in professional housing constitutes an example of enhanced natural radioactivity which can induce health risks on workers and public. Besides, the radon is present in the dwelling houses (the domestic radon). On 13 May 1996, the European Union Council issued the new EURATOM Instruction that establishes the basic standards of health protection of population and workers against the ionizing radiation hazards (Instruction 96/29/EURATOM, JOCE L-159 of 29 June 1996). This instruction does not apply to domestic radon but it is taken into consideration by another EURATOM document: the recommendation of the Commission 90/143/EURATOM of 21 February 1990 (JOCE L-80 of 27 March 1990). The present paper aims at establishing in accordance to European Union provisions the guidelines for radon risk management in working places, as well as in dwelling houses, where the implied risk is taken into account. This document does not deal with cases of high radon concentration on sites where fabrication, handling or storage of radium sources take place. These situations must be treated by special studies.

  17. Consumer's Guide to Radon Reduction

    Science.gov (United States)

    ... Radon Share Facebook Twitter Google+ Pinterest Contact Us Consumer's Guide to Radon Reduction: How to Fix Your ... See EPA’s About PDF page to learn more. Consumer's Guide to Radon Reduction: How to Fix Your ...

  18. Radon therapy; Radon in der Therapie

    Energy Technology Data Exchange (ETDEWEB)

    Spruck, Kaija [Technische Hochschule Mittelhessen, Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz

    2017-04-01

    Radon therapies are used since more than 100 years in human medicine. Today this method is controversially discussed due to the possible increase of ionizing radiation induced tumor risk. Although the exact mode of biological radiation effect on the cell level is still not known new studies show the efficiency of the radon therapy without side effect for instance for rheumatic/inflammatory or respiratory disorders.

  19. Radon-Instrumentation; Radon-Instrumentacion

    Energy Technology Data Exchange (ETDEWEB)

    Moreno y Moreno, A. [Departamento de Apoyo en Ciencias Aplicadas, Benemerita Universidad Autonoma de Puebla, 4 Sur 104, Centro Historico 72000 Puebla (Mexico)

    2003-07-01

    The presentation of the active and passive methods for radon, their identification and measure, instrumentation and characteristics are the objectives of this work. Active detectors: Active Alpha Cam Continuous Air Monitor, Model 758 of Victoreen, Model CMR-510 Continuous Radon Monitor of the Signature Femto-Tech. Passive detectors: SSNTD track detectors in solids Measurement Using Charcoal Canisters, disk of activated coal deposited in a metallic box Electrets Methodology. (Author)

  20. LARGE BUILDING RADON MANUAL

    Science.gov (United States)

    The report summarizes information on how bilding systems -- especially the heating, ventilating, and air-conditioning (HVAC) system -- inclurence radon entry into large buildings and can be used to mitigate radon problems. It addresses the fundamentals of large building HVAC syst...

  1. Radon and Cancer

    Science.gov (United States)

    ... exposure and lung cancer: the Iowa Radon Lung Cancer Study. American Journal of Epidemiology 2000; 151(11):1091–1102. [PubMed Abstract] Frumkin H, Samet JM. Radon. CA: A Cancer Journal for Clinicians 2001; 51(6):337–344. [ ...

  2. LARGE BUILDING RADON MANUAL

    Science.gov (United States)

    The report summarizes information on how bilding systems -- especially the heating, ventilating, and air-conditioning (HVAC) system -- inclurence radon entry into large buildings and can be used to mitigate radon problems. It addresses the fundamentals of large building HVAC syst...

  3. Bayesian Prediction of Mean Indoor Radon Concentrations for Minnesota Counties

    Energy Technology Data Exchange (ETDEWEB)

    Price, P.N.; Nero, A.V.; Gelman, A.

    1995-08-01

    Past efforts to identify areas having higher than average indoor radon concentrations by examining the statistical relationship between local mean concentrations and physical parameters such as the soil radium concentration have been hampered by the noise in local means caused by the small number of homes monitored in some or most areas, In the present paper, indoor radon data from a survey in Minnesota are analyzed in such a way as to minimize the effect of finite sample size within counties, in order to determine the true county-to-county variation of indoor radon concentrations in the state and the extent to which this variation is explained by the variation in surficial radium concentration among counties, The analysis uses hierarchical modeling, in which some parameters of interest (such as county geometric mean (GM) radon concentrations) are assumed to be drawn from a single population, for which the distributional parameters are estimated from the data. Extensions of this technique, known as a random effects regression and mixed effects regression, are used to determine the relationship between predictive variables and indoor radon concentrations; the results are used to refine the predictions of each county's radon levels, resulting in a great decrease in uncertainty. The true county-to-county variation of GM radon levels is found to be substantially less than the county-to-county variation of the observed GMs, much of which is due to the small sample size in each county. The variation in the logarithm of surficial radium content is shown to explain approximately 80% of the variation of the logarithm of GM radon concentration among counties. The influences of housing and measurement factors, such as whether the monitored home has a basement and whether the measurement was made in a basement, are also discussed. This approach offers a self-consistent statistical method for predicting the mean values of indoor radon concentrations or other geographically

  4. Seismic Shear Energy Reflection By Radon-Fourier Transform

    Directory of Open Access Journals (Sweden)

    Malik Umairia

    2016-01-01

    Full Text Available Seismic waves split in an anisotropic medium, instead of rotating horizontal component to principal direction, Radon-Fourier is derived to observe the signature of shear wave reflection. Synthetic model with fracture is built and discretized using finite difference scheme for spatial and time domain. Common depth point (CDP with single shot gives traces and automatic gain is preprocessed before Radon Transform (RT, a filtering technique gives radon domain. It makes easier to observe fractures at specific incidence and improves its quality in some way by removing the noise. A comparison of synthetic data and BF-data is performed on the basis of root means square error (RMS values. The RMS error is minimum at the 10th trace in radon domain.

  5. Mutagenicity of radon and radon daughters

    Energy Technology Data Exchange (ETDEWEB)

    Evans, H.H.

    1991-01-01

    The objective of our research is to investigate the dose-response relationship of the lethal and mutagenic effects of exposure of cells to radon and its decay products. Dose rate dependence and the nature of the DNA lesion will be studied, using the thymidine kinase and HPRT loci to measure mutation frequency. A deficiency in DNA repair is shown to lead to a greater proportion of mutants with intergenic lesions. The cytotoxic effects of radon and its daughters are similar in human TK6 lymphoblasts and mouse L5178Y lymphoblasts, the cell line used in previous experiments. The results of molecular analysis of four spontaneous and 25 X-radiation induced HPRT{sup {minus}} mutants. Eleven radon-induced HPRT{sup {minus}} mutants have been isolated, and will be analyzed in a similar fashion. 9 figs.

  6. Using the generalized Radon transform for detection of curves in noisy images

    DEFF Research Database (Denmark)

    Toft, Peter Aundal

    1996-01-01

    In this paper the discrete generalized Radon transform will be investigated as a tool for detection of curves in noisy digital images. The discrete generalized Radon transform maps an image into a parameter domain, where curves following a specific parameterized curve form will correspond to a peak...... in the parameter domain. A major advantage of the generalized Radon transform is that the curves are allowed to intersect. This enables a thresholding algorithm in the parameter domain for simultaneous detection of curve parameters. A threshold level based on the noise level in the image is derived. A numerical...

  7. Indoor radon in Slovenia

    Directory of Open Access Journals (Sweden)

    Vaupotič Janja

    2003-01-01

    Full Text Available The Slovenian Radon Programme started in 1990. Since then, radon and radon short-lived decay products have been surveyed in 730 kindergartens, 890 schools, 1000 randomly selected homes, 5 major spas, 26 major hospitals, 10 major municipal water supply plants, and 8 major wineries. Alpha scintillation cells, etched track detectors, electret-based detectors and various continuously measuring devices have been used. On the basis of estimated effective doses, decisions were made on appropriate mitigation. In total, 35 buildings have been appropriately modified. The programme is displayed and results reviewed chronologically and discussed.

  8. Radon Optical Processing in Radon Space.

    Science.gov (United States)

    1986-06-15

    yields one line through the three-dimensional Fourier transform 1. Radon, J., " Uber die Bestimmung von Funktiontn of the three-dimensional function (3...Alamos, New Mexico , April 11-15. 1983.a 6. W. G. Wee, "Application of projection techniques to image image. Figure 1(a) has approximately 8.0 bits/pixel

  9. P-Adic Analog of Navier–Stokes Equations: Dynamics of Fluid’s Flow in Percolation Networks (from Discrete Dynamics with Hierarchic Interactions to Continuous Universal Scaling Model

    Directory of Open Access Journals (Sweden)

    Klaudia Oleschko

    2017-04-01

    Full Text Available Recently p-adic (and, more generally, ultrametric spaces representing tree-like networks of percolation, and as a special case of capillary patterns in porous media, started to be used to model the propagation of fluids (e.g., oil, water, oil-in-water, and water-in-oil emulsion. The aim of this note is to derive p-adic dynamics described by fractional differential operators (Vladimirov operators starting with discrete dynamics based on hierarchically-structured interactions between the fluids’ volumes concentrated at different levels of the percolation tree and coming to the multiscale universal topology of the percolating nets. Similar systems of discrete hierarchic equations were widely applied to modeling of turbulence. However, in the present work this similarity is only formal since, in our model, the trees are real physical patterns with a tree-like topology of capillaries (or fractures in random porous media (not cascade trees, as in the case of turbulence, which we will be discussed elsewhere for the spinner flowmeter commonly used in the petroleum industry. By going to the “continuous limit” (with respect to the p-adic topology we represent the dynamics on the tree-like configuration space as an evolutionary nonlinear p-adic fractional (pseudo- differential equation, the tree-like analog of the Navier–Stokes equation. We hope that our work helps to come closer to a nonlinear equation solution, taking into account the scaling, hierarchies, and formal derivations, imprinted from the similar properties of the real physical world. Once this coupling is resolved, the more problematic question of information scaling in industrial applications will be achieved.

  10. Indoor Radon Measurement in Van

    Science.gov (United States)

    Kam, E.; Osmanlioglu, A. E.; Dogan, I.; Celebi, N.

    2007-04-01

    In this study, indoor radon concentrations obtained from the radon surveys conducted in the Van. Radon monitoring was performed by applying a passive, time-integrating measuring technique. For this purpose, CR-39 nuclear track detectors were installed in dwellings for 2 months. After the monitoring period, detectors were collected. In order to make the alpha tracks visible, chemical etching was applied to the exposed detectors. Nuclear track numbers and the corresponding indoor radon concentrations were determined. Annual effective dose equivalents and the risk probabilities caused by indoor radon inhalation were calculated, and the found results compared with the indoor radon concentrations' data measured in different provinces of Turkey.

  11. ROE Radon Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The polygon dataset represents predicted indoor radon screening levels in counties across the United States. These data were provided by EPA’s Office of Radiation...

  12. Radon in Schools

    Science.gov (United States)

    ... strategy below. Top of Page Testing and Mitigation Standards for Schools Copies of the following Radon Standards ... control is a critical component of any comprehensive indoor air quality (IAQ) management program, l earn how to manage ...

  13. Radon i danske lejeboliger

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn; Skytte Clausen, Louise

    I denne undersøgelse kortlægges radonindholdet i indeluften og det undersøges, hvordan indholdet af radon i indeluften er fordelt og spredes i en ejendom, og om det er muligt at pege på en bygningsdel eller en bygningskomponent som en spredningsvej for radon i boliger. Boligerne er lejeboliger og...... ligger i etageejendomme, kæde- og rækkehuse tilhørende bygningstyper opført fra 1850 og frem. De udvalgte ejendomme ligger i områder af landet, hvor der ved tidligere undersøgelser har vist sig at være en stor andel af huse med et højt indhold af radon i indeluften. Koncentrationen af radon er målt over...

  14. Radon og boligen

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    Radon er en radioaktiv og sundhedsskadelig luftart, som ved indånding øger risikoen for lungekræft. Der er ingen dokumenteret nedre grænse for, hvornår radon er ufarligt. Derfor anbefales det, at man tilstræber et så lavt radonindhold i indeluften som muligt. Man kan hverken lugte, se, høre eller...... smage radon, så vil du vide, om du har radon i din bolig, må du måle radonindholdet i indeluften. Radon forekommer naturligt i jorden og kan suges ind sammen med jordluft, hvis der inde er et undertryk, og hvis konstruktionerne mod jord er utætte. Jordluft trænger ind gennem revner og utætte samlinger......, fx omkring rør til kloak, vand og varmeforsyning. Koncentrationen af radon i jorden varierer meget fra sted til sted, også lokalt og gennem året. Tidligere undersøgelser har vist, at der kan forekomme høje koncentrationer i Sydgrønland, specielt i området syd for Narsalik ved Paamiut, 61°30’N....

  15. Radon in land use planning; Radon i arealplanlegging

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    Radon poses a health risk. Therefore, it is important that the municipality takes into account radon, in land use planning. This Radiation Info provides an overview of what makes an additional radon prone area and what tools are available to assess this. The background is the Planning and Building Act provisions on risk analysis (ROS) and zones. (eb)

  16. Radon as a hydrological indicator

    Energy Technology Data Exchange (ETDEWEB)

    Komae, Takami [National Research Inst. of Agricultural Engineering, Tsukuba, Ibaraki (Japan)

    1997-02-01

    The radon concentration in water is measured by a liquid scintillation method. After the radioactive equilibrium between radon and the daughter nuclides was attained, the radon concentration was determined by the liquid scintillation analyzer. {alpha}-ray from radon, then two {beta}- and two {alpha}-ray from the daughter nuclei group were released, so that 500% of the apparent counting efficiency was obtained. The detector limit is about 0.03 Bq/l, the low value, which corresponds to about 5.4x10{sup -15} ppm. By determining the radon concentration in groundwater, behavior of radon in hydrological process, the groundwater exchange caused by pumping and exchange between river water and groundwater were investigated. The water circulation analysis by means of radon indicator in the environment was shown. By using the large difference of radon concentration between in river water and in groundwater, arrival of injected water to the sampling point of groundwater was detected. (S.Y.)

  17. An approach to define potential radon emission level maps using indoor radon concentration measurements and radiogeochemical data positive proportion relationships.

    Science.gov (United States)

    Drolet, Jean-Philippe; Martel, Richard; Poulin, Patrick; Dessau, Jean-Claude; Lavoie, Denis; Parent, Michel; Lévesque, Benoît

    2013-10-01

    The aim of this paper is to present the first step of a new approach to make a map of radonprone areas showing different potential radon emission levels in the Quebec province. This map is a tool intended to assist the Quebec government in identifying populations with a higher risk of indoor radon gas exposure. This map of radon-prone areas used available radiogeochemical information for the province of Quebec: (1) Equivalent uranium (eU) concentration from airborne surface gamma-ray surveys; (2) uranium concentration measurements in sediments; and (3) bedrock and surficial geology. Positive proportion relationships (PPR) between each individual criterion and the 1417 available basement radon concentrations were demonstrated. It was also shown that those criteria were reliable indicators of radon-prone areas. The three criteria were discretized into 3, 2 and 2 statistically significant different classes respectively. For each class, statistical heterogeneity was validated by Kruskal-Wallis one way analyses of variance on ranks. Maps of radon-prone areas were traced down for each criterion. Based on this statistical study and on the maps of radon-prone areas in Quebec, 18% of the dwellings located in areas with an equivalent uranium (eU) concentration from airborne surface gamma-ray surveys under 0.75 ppm showed indoor radon concentrations above 150 Bq/m3. This percentage increases to 33% when eU concentrations are between 0.75 ppm and 1.25 ppm and exceeds 40% when eU concentrations are above 1.25 ppm. A uranium concentration in sediments above 20 ppm showed an indoor radon concentration geometric mean of 215 Bq/m3 with more than 69% of the dwellings exceeding 150 Bq/m3 or more than 50% of dwellings exceeding the Canadian radon guideline of 200 Bq/m3. It is also shown that the radon emission potential is higher where a uranium-rich bedrock unit is not covered by a low permeability (silt/clay) surficial deposit.

  18. The radon EDM apparatus

    Science.gov (United States)

    Tardiff, E. R.; Rand, E. T.; Ball, G. C.; Chupp, T. E.; Garnsworthy, A. B.; Garrett, P.; Hayden, M. E.; Kierans, C. A.; Lorenzon, W.; Pearson, M. R.; Schaub, C.; Svensson, C. E.

    2014-01-01

    The observation of a permanent electric dipole moment (EDM) at current experimentally accessible levels would provide clear evidence of physics beyond the Standard Model. EDMs violate CP symmetry, making them a possible route to explaining the size of the observed baryon asymmetry in the universe. The Radon EDM Experiment aims to search for an EDM in radon isotopes whose sensitivity to CP-odd interactions is enhanced by octupole-deformed nuclei. A prototype apparatus currently installed in the ISAC hall at TRIUMF includes a gas handling system to move radon from a collection foil to a measurement cell and auxiliary equipment for polarization diagnostics and validation. The features and capabilities of the apparatus are described and an overview of the experimental design for a gamma-ray-anisotropy based EDM measurement is provided.

  19. Radon: a bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Lepman, S.R.; Boegel, M.L.; Hollowell, C.D.

    1981-01-01

    The Lawrence Berkeley Laboratory, with the support of the Department of Energy, has developed a computerized database to manage research information in the area of building ventilation and indoor air quality. This literature survey contains references pertaining to the physical properties of radon and its daughters, instrumentation for their measurement, health effects, surveys and measurements, and regulatory information. The references in the bibliography are sequenced in alphabetical order and abstracts are included when supplied by the author. The objective of this report is to disseminate the bibliographic references compiled at the laboratory relating to radon research portion of the program. Interested database users are encouraged to contact the laboratory to receive instructions for direct database acess. A flyer describing the database is supplied at the end of the bibliography and a brief overview of the Radon Research porgram is given.

  20. Radon programmes and health marketing.

    Science.gov (United States)

    Fojtikova, Ivana; Rovenska, Katerina

    2011-05-01

    Being aware of negative health effects of radon exposure, many countries aim for the reduction of the radon exposure of their population. The Czech radon programme was commenced >20 y ago. Since then experts have gathered a lot of knowledge, necessary legislation has been enacted, tens of thousands of inhabitants have been offered free measurement and subsidy for the mitigation. Despite the effort, the effectiveness of the radon programme seems to be poor. Newly built houses still exhibit elevated radon concentrations and the number of houses mitigated is very low. Is it possible to enhance the effectivity of radon programme while keeping it on a voluntary basis? One possible way is to employ health marketing that draws together traditional marketing theories and science-based strategies to prevention. The potential of using marketing principles in communication and delivery of radon information will be discussed.

  1. Radon assay for SNO+

    Energy Technology Data Exchange (ETDEWEB)

    Rumleskie, Janet [Laurentian University, Greater Sudbury, Ontario (Canada)

    2015-12-31

    The SNO+ experiment will study neutrinos while located 6,800 feet below the surface of the earth at SNOLAB. Though shielded from surface backgrounds, emanation of radon radioisotopes from the surrounding rock leads to back-grounds. The characteristic decay of radon and its daughters allows for an alpha detection technique to count the amount of Rn-222 atoms collected. Traps can collect Rn-222 from various positions and materials, including an assay skid that will collect Rn-222 from the organic liquid scintillator used to detect interactions within SNO+.

  2. Cuspidal discrete series for projective hyperbolic spaces

    DEFF Research Database (Denmark)

    Andersen, Nils Byrial; Flensted-Jensen, Mogens

    2013-01-01

    Abstract. We have in [1] proposed a definition of cusp forms on semisimple symmetric spaces G/H, involving the notion of a Radon transform and a related Abel transform. For the real non-Riemannian hyperbolic spaces, we showed that there exists an infinite number of cuspidal discrete series, and a...

  3. Publications about Radon

    Science.gov (United States)

    There is no known safe level of exposure to radon. EPA strongly recommends that you fix your home if your test shows 4 picocuries (pCi/L) or more. These publications and resources will provide you with the information you need to fix your home.

  4. What Is Radon?

    Science.gov (United States)

    ... in both cigarette smoke and radon. In some animals, the risk of certain other cancers was also increased. In lab studies using human ... cancer grow is called a carcinogen .) The American Cancer Society looks to these ... laboratory, animal, and human research studies. Based on animal and ...

  5. The Chemistry of Radon

    Science.gov (United States)

    Avrorin, V. V.; Krasikova, R. N.; Nefedov, V. D.; Toropova, M. A.

    1982-01-01

    We shall review the discovery of this element, studies of its chemical nature, and modern ideas on its chemical and physical properties. Possible chemical and nuclear-chemical methods of synthesising new radon compounds and of determining their properties and their identity will be discussed, using information published up to May 1980. 121 references.

  6. Environmental radon studies in Mexico.

    Science.gov (United States)

    Segovia, N; Gaso, M I; Armienta, M A

    2007-04-01

    Radon has been determined in soil, groundwater, and air in Mexico, both indoors and outdoors, as part of geophysical studies and to estimate effective doses as a result of radon exposure. Detection of radon has mainly been performed with solid-state nuclear track detectors (SSNTD) and, occasionally, with active detection devices based on silicon detectors or ionization chambers. The liquid scintillation technique, also, has been used for determination of radon in groundwater. The adjusted geometric mean indoor radon concentration (74 Bq m-3) in urban developments, for example Mexico City, is higher than the worldwide median concentration of radon in dwellings. In some regions, particularly hilly regions of Mexico where air pollution is high, radon concentrations are higher than action levels and the effective dose for the general population has increased. Higher soil radon levels have been found in the uranium mining areas in the northern part of the country. Groundwater radon levels are, in general, low. Soil-air radon contributing to indoor atmospheres and air pollution is the main source of increased exposure of the population.

  7. The NIST Primary Radon-222 Measurement System

    OpenAIRE

    Collé, R.; Hutchinson, J. M. R.; Unterweger, M. P.

    1990-01-01

    Within the United States, the national standard for radon measurements is embodied in a primary radon measurement system that has been maintained for over 50 years to accurately measure radon (222Rn) against international and national radium (226Ra) standards. In turn, all of the radon measurements made at the National Institute of Standards and Technology (NIST) and the radon transfer calibration standards and calibration services provided by NIST are directly related to this national radon ...

  8. Radon and lung cancer; Radon et cancer du poumon

    Energy Technology Data Exchange (ETDEWEB)

    Baysson, H; Billon, S.; Catelinois, O.; Gambard, J.P.; Laurier, D.; Rogel, A.; Tirmarche, M

    2004-12-01

    Radon is a natural radioactive gas that tends to accumulate in indoor environments; its concentration is highest in areas with granite sub-soils. Epidemiologic studies of uranium miners and animal data demonstrate the radon inhalation increases the risk of lung cancer. The objective of this paper is to present the available data on the French population's exposure to radon and the current epidemiologic knowledge of its effects, from cohort studies of uranium miners and indoor radon case-control studies.

  9. Legal issues in radon affairs

    Energy Technology Data Exchange (ETDEWEB)

    Massuelle, M.H. [Inst. de Protection et de Surete Nucleaire, Fontenay aux Roses (France)

    1999-12-01

    In France, it was only recently that cases related to high radon concentrations in dwellings received substantial publicity. This irruption of radon as a public health issue came with the general progress of scientific knowledge and the availability of a research capacity in France able to develop expertise. We are interested here in the legal implications of issues that arise from the lag between the activity of expertsand the regulatory activity in the domain of radon. We use the term expertise very broadly, to cover the practical application of research findings, the relation of the researchers with the community, and finally the acts by which experts provide their knowledge to the community. We first examine the course by which science developed the radon issue and the way they organized to move from research to expertise; here we try to characterize the various needs for radon expertise. We then discuss the legal difficulties associated with radon expertise.

  10. Radon mapping strategies in Austria.

    Science.gov (United States)

    Gruber, V; Ringer, W; Wurm, G; Friedmann, H

    2015-11-01

    According to current European and international recommendations (e.g. by IAEA, WHO and European Union), countries shall identify high radon areas. In Austria, this task was initiated already in the early 1990s, which yielded the first Austrian Radon Potential Map. This map is still in use, updated with recent indoor radon data in 2012. The map is based on radon gas measurements in randomly selected dwellings, normalised to a standard situation. To meet the current (legal) requirements, uncertainties in the existing Austrian radon map should be reduced. A new indoor radon survey with a different sampling strategy was started, and possible mapping methods are studied and tested. In this paper, the methodology for the existing map as well as the planned strategies to improve this map is discussed.

  11. Legal issues in radon affairs

    Energy Technology Data Exchange (ETDEWEB)

    Massuelle, M.H. [Inst. de Protection et de Surete Nucleaire, Fontenay aux Roses (France)

    1999-12-01

    In France, it was only recently that cases related to high radon concentrations in dwellings received substantial publicity. This irruption of radon as a public health issue came with the general progress of scientific knowledge and the availability of a research capacity in France able to develop expertise. We are interested here in the legal implications of issues that arise from the lag between the activity of expertsand the regulatory activity in the domain of radon. We use the term expertise very broadly, to cover the practical application of research findings, the relation of the researchers with the community, and finally the acts by which experts provide their knowledge to the community. We first examine the course by which science developed the radon issue and the way they organized to move from research to expertise; here we try to characterize the various needs for radon expertise. We then discuss the legal difficulties associated with radon expertise.

  12. ERRICCA radon model intercomparison exercise

    DEFF Research Database (Denmark)

    Andersen, C.E.; Albarracín, D.; Csige, I.

    1999-01-01

    Numerical models based on finite-difference or finite-element methods are used by various research groups in studies of radon-222 transport through soil and building materials. Applications range from design of radon remediation systems to morefundamental studies of radon transport. To ascertain ......, still remain. All in all, it seems that the exercise has served its purpose and stimulated improvements relating to the quality of numerical modelling of radon transport. To maintain a high quality of modelling, it is recommendedthat additional exercises are carried out....

  13. (Mutagenicity of radon and radon daughters)

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The current objective of our research is to investigate the dose-response relationship of the lethal and mutagenic effects of exposure of cells to radon and its decay products. Dose-rate dependence will be studied, as well as the nature of the DNA lesions. The effect of DNA repair on the lethal and mutagenic effects of exposure and on the character of the DNA lesions will be investigated by comparing the response of L5178Y strains which differ in their ability to rejoin X radiation-induced DNA double-strand breaks. This report discusses progress incurred from 4/1/1988--10/1/1990. 5 refs., 9 figs., 6 tabs.

  14. Nanodosimetry and nanodosimetric-based models of radiation action for radon alpha particles

    Energy Technology Data Exchange (ETDEWEB)

    Zaider, M.

    1992-01-01

    We report on a theory for describing the biological effects of ionizing radiation in particular radon [alpha] particles. Behind this approach is the recognition that biological effects such as chromosome aberrations, cellular transformation, cellular inactivation, etc, are the result of a hierarchic sequence of radiation effects. We indicate how to treat each of the individual processes in this sequence, and also how to relate one effect to the hierarchically superior one.

  15. Radon - environmental pollutant from underground. Radon - Umweltgift aus dem Erdreich

    Energy Technology Data Exchange (ETDEWEB)

    Obertreis, R.

    1988-01-01

    Radon is responsible for about 50% of the natural radiation load of 200 mrem/a in the Federal Republic of Germany. This implies that approximately 190.000 households with about 600.000 citizens of the Federal Republic face an increased risk of lung cancer. Hints are given as to the reduction of radon values in cellars and living rooms. (DG).

  16. APPLICATION OF RADON REDUCTION METHODS

    Science.gov (United States)

    The document is intended to aid homeowners and contractors in diagnosing and solving indoor radon problems. It will also be useful to State and Federal regulatory officials and many other persons who provide advice on the selection, design and operation of radon reduction methods...

  17. Modern state of radon chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Avrorin, V.V.; Krasikova, R.N.; Nefedov, V.D.; Toropova, M.A. (Leningradskij Gosudarstvennyj Univ. (USSR))

    1982-01-01

    A review of works on radon chemistry published up to May, 1980, is presented. Physical properties of the element, are described as well as peculiarities in the field of its chemical investigations connected with unfavourable nuclear-physical characteristics of radon isotopes, with specificity of its electron structure. Characteristics of the known radon compounds, including impurity compounds, their stability, are given. Possible chemical and nuclear-chemical approaches to the solution of problems of synthesis, determination of properties, and identification of its new compounds are discussed. The advantage of using electron capture processes for radon compound synthesis, possibility to use nuclear reactions induced by accelerated elementary particles, are pointed out. Possible applications of radon compounds are considered.

  18. Citizen's Guide to Radon: The Guide to Protecting Yourself and Your Family from Radon

    Science.gov (United States)

    ... Agency Search Search Radon Contact Us Share A Citizen's Guide to Radon: The Guide to Protecting Yourself ... EPA’s About PDF page to learn more. A Citizen's Guide to Radon - Revised December 2016 (PDF) (16 ...

  19. CONTRIBUTION OF RADON FLOWS AND RADON SOURCES TO THE RADON CONCENTRATION IN A DWELLING

    NARCIS (Netherlands)

    DEMEIJER, RJ; STOOP, P; PUT, LW

    1992-01-01

    In this paper a model is presented for analysis of the radon concentrations in a compartment in terms of contributions from transport by flows of air between compartments and from radon sources in the compartment. Measurements were made to study the effect of increased natural ventilation of the cra

  20. CONTRIBUTION OF RADON FLOWS AND RADON SOURCES TO THE RADON CONCENTRATION IN A DWELLING

    NARCIS (Netherlands)

    DEMEIJER, RJ; STOOP, P; PUT, LW

    1992-01-01

    In this paper a model is presented for analysis of the radon concentrations in a compartment in terms of contributions from transport by flows of air between compartments and from radon sources in the compartment. Measurements were made to study the effect of increased natural ventilation of the cra

  1. Radon risk management. Construction solutions

    Directory of Open Access Journals (Sweden)

    Borja Frutos Vázquez

    2011-12-01

    Full Text Available Radon gas is a radioactive element that appears in nature by the decay of radium found in terrestrial soils. This gas is able to travel between the pores of the ground and enter into the buildings where the concentration can increase and becoming a health risk to occupants from inhaling. The World Health Organization rate the radon gas as a level 1 carcinogen agent. According to this organization, radon is the second leading cause of lung cancer contraction after tobacco. Based on the perception of risk derived from epidemiological medical studies, some countries have established radon concentration values as safety limits, above which is recommended or required an architectural intervention to reduce levels. From an architectural perspective, there have been studies of several radon protection techniques to reduce radon immission in buildings or to evacuate it, in order to reduce the radon levels below the safety limits. This article develops some protection strategies that have been being used for these purposes, some of which have been tested in Spain thanks to a research project funded by the Nuclear Safety Council, and developed by the Eduardo Torroja Institute and the University of Cantabria.

  2. Uranium mill tailings and radon

    Energy Technology Data Exchange (ETDEWEB)

    Hanchey, L A

    1981-01-01

    The major health hazard from uranium mill tailings is presumed to be respiratory cancer resulting from the inhalation of radon daughter products. A review of studies on inhalation of radon and its daughters indicates that the hazard from the tailings is extremely small. If the assumptions used in the studies are correct, one or two people per year in the US may develop cancer as a result of radon exhaled from all the Uranium Mill Tailings Remedial Action Program sites. The remedial action should reduce the hazard from the tailings by a factor of about 100.

  3. Guidance on Radon Resistant Construction and Radon Mitigation

    Science.gov (United States)

    This Unnumbered Letter regarding radon gas mitigation applies to all housing and community facilities, low-rise buildings and dwellings for the mentioned programs. Its intention is to guide staff to best serve our borrowers and protect their health.

  4. Geohydrological control on radon availability in groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Yogesh; Prasad, Ganesh [Department of Physics, H. N. B. Garhwal University, Badshahi Thaul Campus, Tehri Garhwal 249 199 (India); Choubey, V.M. [Wadia Institute of Himalayan Geology, Dehradun 248001 (India); Ramola, R.C. [Department of Physics, H. N. B. Garhwal University, Badshahi Thaul Campus, Tehri Garhwal 249 199 (India)], E-mail: rcramola@gmail.com

    2009-01-15

    The radon content in groundwater sources depends on the radium concentration in the rock of the aquifer. Radon was measured in water in many parts of the world, mostly for the risk assessment due to consumption of drinking water. The exposure to radon through drinking water is largely by inhalation and ingestion. Airborne radon can be released during normal household activities and can pose a greater potential health risk than radon ingested with water. Transport of radon through soil and bedrock by water depends mainly on the percolation of water through the pores and along fractured planes of bedrock. In this study, radon concentration in springs and hand pumps of Kumaun and Garhwal Himalaya, India was measured using radon emanometry technique. The study shows that radon concentration in springs and hand pumps is controlled by geohydrological characteristics, which in turn is also governed by tectonic processes.

  5. Radon risk in the house; Il rischio radon nelle abitazioni

    Energy Technology Data Exchange (ETDEWEB)

    Bressa, G. [Padua Univ., Padua (Italy). Dipt. di Farmacologia e Anestesiologia, Lab. di Tossicologia

    2001-04-01

    Radon was discovered in 1900, but its potential dangerousness for man was fully understood only in 1950. Being a radioactive natural gas - and therefore particularly dangerous - radon results from the long decay chain of radionuclides, such as thorium and radium. Some igneous rocks (granite, tufa and lava) as well as coal are considered to be the main sources of this radionuclide. A number of epidemiologic studies have shown the carcinogenicity of this element, particularly among miners and workers subjected to high level exposure in confined spaces such as basements, garages, cellars, etc. There are, however, some techniques to remove radon in order to reduce exposure to minimum values. [Italian] Il radon fu scoperto nel 1900, ma solo nel 1950 si comprese la sua potenziale pericolosita' per l'uomo. Il radon e' particolarmente pericoloso essendo un gas naturale radioattivo. Esso proviene dalla lunga catena di decadimento di radionuclidi come il torio e di radio. Sorgenti di tale radionuclide sono da considerarsi principalmente alcune rocce ignee (graniti, tufi e lave) e il carbone. Diversi studi epidemiologici hanno evidenziato la cancerogenicita' di tale elemento, specie tra i minatori e soggetti esposti ad alti livelli in ambienti confinati quali scantinati, garage sotterranei, ecc.. Esistono comunque tecniche di intervento per la rimozione del gas radon in modo tale da ridurre l'esposizione a valori minimi.

  6. Radon Like atmospheric pollutant; El gas Radon como contaminante atmosferico

    Energy Technology Data Exchange (ETDEWEB)

    Quindos Poncela, L. S.; Sainz Fernandez, C.; Quindos Lopez, L.; Fuente Merino, I.; Arteche, J. L.

    2008-07-01

    In this work different aspects about the problem of the radon in dwellings are approached. This gas of natural origin is virtually present in all the soils in the earths crust due to the presence of uranium and radium in the composition of them. Depending on architectural factors and of occupancy habits of the house, high concentrations of this gas can be reached indoors. In these situations, there is a quantifiable increment of the risk of developing lung cancer in the inhabitants of the housing. In the last years the methodological improvements in the realization of epidemiologic studies have led to the obtaining of scientific evidence about the relationship between the presence of indoor radon and the risk of lung cancer. This relationship fund years ago in workers of uranium mines, has been corroborated in the case of the residential radon by the light of several recent meta-analysis performed on groups of epidemiologic studies. More than 4000 radon measurements have been carried out in spain during the las 25 years. A summary of the results obtained from the main national radon surveys are also presented, as well as the criteria recently established by the Spanish Nuclear Safety Council concerning radon action levels in dwellings and workplaces. (Author) 18 refs.

  7. VENTILATION INFLUENCE UPON INDOOR AIR RADON LEVEL

    Institute of Scientific and Technical Information of China (English)

    田德源

    1995-01-01

    Levels of indoor radon in air are studied by a continuous electrostatic radon monitor under normal living conditions to evaluate the influence of air conditioned ventilation on indoor air radon level.Results show that the indoor air radon concentrations are not much more than those without household conditioner living condition.although using household conditioner requires a sealed room which should lead to a higher radon level.Turning on air conditioner helps lower indoor radon level.Therefore.the total indoor air Rn levels are normal>ventilation>exhaust or indraft> exhaust plus indraft.

  8. Evolution of radon dose evaluation

    Directory of Open Access Journals (Sweden)

    Fujimoto Kenzo

    2004-01-01

    Full Text Available The historical change of radon dose evaluation is reviewed based on the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR reports. Since 1955, radon has been recognized as one of the important sources of exposure of the general public. However, it was not really understood that radon is the largest dose contributor until 1977 when a new concept of effective dose equivalent was introduced by International Commission on Radiological Protection. In 1982, the dose concept was also adapted by UNSCEAR and evaluated per caput dose from natural radiation. Many researches have been carried out since then. However, lots of questions have remained open in radon problems, such as the radiation weighting factor of 20 for alpha rays and the large discrepancy of risk estimation among dosimetric and epidemiological approaches.

  9. A Physician's Guide to Radon

    Science.gov (United States)

    This booklet has been developed for physicians by the U.S. Environmental Protection Agency in consultation with the American Medical Association (AMA). Its purpose is to enlist physicians in the national effort to inform the American public about radon.

  10. A Radon Progeny Deposition Model

    CERN Document Server

    Guiseppe, V E; Hime, A; Rielage, K; Westerdale, S

    2011-01-01

    The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly Rn-222) and its subsequent progeny present in an experiment are potential backgrounds, also problematic is the deposition of radon progeny on detector materials. Exposure to radon at any stage of assembly of an experiment can result in surface contamination by progeny supported by the long half life (22 y) of Pb-210 on sensitive locations of a detector. An understanding of the potential surface contamination from deposition will enable requirements of radon-reduced air and clean room environments for the assembly of low background experiments. It is known that there are a number of environmental factors that govern the deposition of progeny onto surfaces. However, existing models have not explored the impact of some environmental factors important for low background experiments. A test stand has been constructed to depos...

  11. Discrete Mathematics

    DEFF Research Database (Denmark)

    Sørensen, John Aasted

    2011-01-01

    The objectives of Discrete Mathematics (IDISM2) are: The introduction of the mathematics needed for analysis, design and verification of discrete systems, including the application within programming languages for computer systems. Having passed the IDISM2 course, the student will be able...... to accomplish the following: -Understand and apply formal representations in discrete mathematics. -Understand and apply formal representations in problems within discrete mathematics. -Understand methods for solving problems in discrete mathematics. -Apply methods for solving problems in discrete mathematics......; construct a finite state machine for a given application. Apply these concepts to new problems. The teaching in Discrete Mathematics is a combination of sessions with lectures and students solving problems, either manually or by using Matlab. Furthermore a selection of projects must be solved and handed...

  12. Hierarchical photocatalysts.

    Science.gov (United States)

    Li, Xin; Yu, Jiaguo; Jaroniec, Mietek

    2016-05-01

    As a green and sustainable technology, semiconductor-based heterogeneous photocatalysis has received much attention in the last few decades because it has potential to solve both energy and environmental problems. To achieve efficient photocatalysts, various hierarchical semiconductors have been designed and fabricated at the micro/nanometer scale in recent years. This review presents a critical appraisal of fabrication methods, growth mechanisms and applications of advanced hierarchical photocatalysts. Especially, the different synthesis strategies such as two-step templating, in situ template-sacrificial dissolution, self-templating method, in situ template-free assembly, chemically induced self-transformation and post-synthesis treatment are highlighted. Finally, some important applications including photocatalytic degradation of pollutants, photocatalytic H2 production and photocatalytic CO2 reduction are reviewed. A thorough assessment of the progress made in photocatalysis may open new opportunities in designing highly effective hierarchical photocatalysts for advanced applications ranging from thermal catalysis, separation and purification processes to solar cells.

  13. Association of School District Policies for Radon Testing and Radon-Resistant New Construction Practices with Indoor Radon Zones.

    Science.gov (United States)

    Foster, Stephanie; Everett Jones, Sherry

    2016-12-13

    Radon is a naturally occurring, colorless, odorless, and tasteless radioactive gas. Without testing, its presence is unknown. Using nationally representative data from the 2012 School Health Policies and Practices Study, we examined whether the prevalence of school district policies for radon testing and for radon-resistant new construction practices varied by district location in relation to the U.S. Environmental Protection Agency Map of Radon Zones. Among school districts located in counties with high predicted average indoor radon, 42.4% had policies for radon testing and 37.5% had policies for radon-resistant new construction practices. These findings suggest a critical need for improved awareness among policy makers regarding potential radon exposure for both students and school staff.

  14. Indoor radon and radon daughters survey at Campinas-Brazil using CR-39: First results

    CERN Document Server

    Guedes, S; Iunes, P J; Navia, L M S; Neman, R S; Paulo, S R; Rodrigues, V C; Souza, W F; Tello, C A S; Zúñiga, A G

    1999-01-01

    The first results of a radon and radon daughters (RD) survey performed at Campinas-SP, Brazil, are presented. We employed a technique that, potentially, makes possible to measure the radon and RD activity in the air and to separate from this result the activity of radon, alone. In this preliminary paper only the former activity is studied.

  15. Radon in Estonian dwellings - Results from a National Radon Survey

    Energy Technology Data Exchange (ETDEWEB)

    Pahapill, Lia; Rulkov, Anne; Rajamaee, Raivo [Estonian Radiation Protection Centre (Kiirguskeskus), Tallinn (Spain); Aakerblom, Gustav [Swedish Radiation Protection Authority, Stockholm (Sweden)

    2003-10-01

    A countrywide survey of radon concentrations in Estonian dwellings was carried out during the period 1998-2001. The survey formed a part of the cooperation program on radiation protection between the Estonian Radiation Protection (Kiirguskeskus) Centre and the Swedish Radiation Protection Authority (SSI). The survey included measurements in a number of dwellings representative for Estonia in detached houses and multifamily buildings (only dwellings on the bottom floor were included in the survey). Altogether, radon concentrations were measured in 515 dwellings, a number large enough to be statistically significant. All measurements were made with alphatrack film detectors of the same type that SSI uses in Sweden. The measurements were made during a 2-3 month period during the winter half-year. Two detectors were used in each dwelling. In Estonia there are 0.17 million dwellings in detached houses and 0.45 million in multi apartment buildings. Of the 1.26 million inhabitants in Estonia. 0.36 million live in detached houses and 0.90 million in multi apartment buildings. Most of the latter were built during the Soviet occupation. Of the dwellings in multifamily buildings 30 % are assumed to be situated on the first floor. The mean radon concentration in dwellings in detached hoses, according to the survey results, is 103 Bq/m{sup 3}, in dwellings on the bottom floor in multi apartment buildings it is 78 Bq/m{sup 3}. In 1% of the dwellings the radon concentration exceeded 400 Bq/m{sup 3}. The highest radon concentration found in the study was 1040 Bq/m{sup 3}. Based on the assumption that the average radon concentration in the dwellings in multi-apartment buildings that are not situated on the bottom floor is 30 Bq/m{sup 3}, and that these dwellings constitute 70% of all dwellings in multi apartment buildings, the mean radon concentration in dwellings in multi apartment buildings is calculated to be 44 Bq/m{sup 3}. The mean value for all Estonia dwellings is calculated

  16. Radon legislation and national guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Aakerblom, G

    1999-07-01

    The International Commission on Radiological Protection (ICRP) and The Council of the European Union have recommended the Member States to take action against radon in homes and at workplaces. Within the EU project European Research into Radon in Construction Concerted Action, ERRICCA, the Topic Group on Legal and Building Code Impact was designated to study the current radon legislation and give advice regarding future enactment of laws and recommendations. On behalf of the Group, a questionnaire on radon legislation was sent out to nearly all European states and a selection of non-European states. Questions were asked regarding reference levels for dwellings, workplaces and drinking water, and about regulations or recommendations for building materials and city planning. All 15 EU Member States, 17 non-EU European countries and 10 non-European countries responded to the questionnaire. Their answers are considered current as of the end of 1998. Most European States and many non-European countries have recommended reference levels for dwellings and workplaces, and some have guidelines for measures against radon incorporated in their building codes and guidelines for construction techniques. However, only a few countries have enforced reference levels or regulations for planning and construction. The reference levels for indoor radon concentration in existing and new dwellings or workplaces are within the range 150-1000 Bq/m{sup 3}. Sweden is the only country (Out of 15 EU member states) which has enforced limits for existing dwellings. Sweden and the UK have both enforced levels for new dwellings. 7 non-European countries (Out of 17 responding countries) have enforced levels for existing dwellings and 9 have them for new dwellings. At the end of 1998, only Finland, Sweden, the Czech Republic, Romania, Russia and the Slovak Republic had limits for radon in water, although 8 countries were planning to introduce such limits. The present limits are within the range for

  17. Least-squares reverse time migration with local Radon-based preconditioning

    KAUST Repository

    Dutta, Gaurav

    2017-03-08

    Least-squares migration (LSM) can produce images with better balanced amplitudes and fewer artifacts than standard migration. The conventional objective function used for LSM minimizes the L2-norm of the data residual between the predicted and the observed data. However, for field-data applications in which the recorded data are noisy and undersampled, the conventional formulation of LSM fails to provide the desired uplift in the quality of the inverted image. We have developed a leastsquares reverse time migration (LSRTM) method using local Radon-based preconditioning to overcome the low signal-tonoise ratio (S/N) problem of noisy or severely undersampled data. A high-resolution local Radon transform of the reflectivity is used, and sparseness constraints are imposed on the inverted reflectivity in the local Radon domain. The sparseness constraint is that the inverted reflectivity is sparse in the Radon domain and each location of the subsurface is represented by a limited number of geologic dips. The forward and the inverse mapping of the reflectivity to the local Radon domain and vice versa is done through 3D Fourier-based discrete Radon transform operators. The weights for the preconditioning are chosen to be varying locally based on the relative amplitudes of the local dips or assigned using quantile measures. Numerical tests on synthetic and field data validate the effectiveness of our approach in producing images with good S/N and fewer aliasing artifacts when compared with standard RTM or standard LSRTM.

  18. Radon as geological tracer

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, T.; Anjos, R.M. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Fisica; Valladares, D.L.; Rizzotto, M.; Velasco, H.; Ayub, J. Juri [Universidad Nacional de San Luis (Argentina). Inst. de Matematica Aplicada San Luis (IMASL); Silva, A.A.R. da; Yoshimura, E.M. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica

    2012-07-01

    Full text: This work presents measurements of {sup 222}Rn levels performed in La Carolina gold mine and Los Condores tungsten mine at the province of San Luis, Argentina, today used for tourist visitation, and can evaluate the potential use of such radioactive noble gas as tracer or marker for geological processes in underground environments. By concentrations of {sup 40}K, {sup 232}Th and {sup 23}'8U were also measured in the walls of tunnels were determined the rocks mineral composition, what indicated that the mines have the same composition. In this sense, we used nuclear trace plastic detectors CR-39, gamma spectrometry of rock samples and Geiger-Muller (GM) monitors The patterns of radon gas transportation processes revealed that La Carolina could be interpreted through a model based on a radioactive gas confined into a single entrance tube, with constant cross section and air velocity. Los Condores, which has a second main entrance, could be interpreted through a model based on a radioactive gas confined into a two entrance tube, allowing a chimney effect for air circulation. The results showed the high potential of using {sup 222}Rn as a geological tracer. In what concerns the occupational hazard, in summer (time of more intense tourist activity in the mine) La Carolina presented a mean concentration of the radioactive noble gas that exceeds in four times the action level of 1,5 kBq m{sup -3} recommended by the International Commission of Radiological Protection (ICRP). The chimney effect shows the low mean concentration of radon in Los Condores. (author)

  19. Nanodosimetry and nanodosimetric-based models of radiation action for radon alpha particles. Progress report, July 1990--June 1992

    Energy Technology Data Exchange (ETDEWEB)

    Zaider, M.

    1992-12-31

    We report on a theory for describing the biological effects of ionizing radiation in particular radon {alpha} particles. Behind this approach is the recognition that biological effects such as chromosome aberrations, cellular transformation, cellular inactivation, etc, are the result of a hierarchic sequence of radiation effects. We indicate how to treat each of the individual processes in this sequence, and also how to relate one effect to the hierarchically superior one.

  20. Indoor radon, geogenic radon surrogates and geology - Investigations on their correlation.

    Science.gov (United States)

    Friedmann, H; Baumgartner, A; Bernreiter, M; Gräser, J; Gruber, V; Kabrt, F; Kaineder, H; Maringer, F J; Ringer, W; Seidel, C; Wurm, G

    2017-01-01

    The indoor radon concentration was measured in most houses in a couple of municipalities in Austria. At the same time the activity concentration of radium in soil, the soil gas radon concentration, the permeability of the ground and the ambient dose equivalent rate were also measured and the geological situations (geological units) were recorded too. From the indoor radon concentration and different house and living parameters a radon potential (Austrian radon potential) was derived which should represent the radon concentration in a standard room. Another radon potential (Neznal radon potential) was calculated from the soil gas radon concentration and the permeability. The aim of the investigation was to correlate all the different variables and to test if the use of surrogate data (e.g. geological information, ambient dose equivalent rate, etc.) can be used to judge the radon risk for an area without performing numerous indoor measurements.

  1. The Austrian radon activities on the way to the national radon action plan.

    Science.gov (United States)

    Gruber, V; Ringer, W; Wurm, G; Haider, W

    2014-07-01

    Based on the new Euratom Basic Safety Standards (BSS), all EU member states will be obliged to design a strategy to address long-term risks from radon exposure, which is laid down in the 'national radon action plan'. In Austria, the National Radon Centre is responsible for the development of the action plan. This paper presents the current and planned radon protection activities on the way to establish the radon action plan--like the national radon database, the definition of radon risk areas by improving the existing radon map, as well as strategies and activities to increase the radon awareness of the public and decision-makers and to involve the building sector. The impact of and the need for actions caused by the BSS requirements on the Austrian radon legislation, strategy and programme are discussed.

  2. Thermo-diffusional radon waves in soils.

    Science.gov (United States)

    Minkin, Leonid; Shapovalov, Alexander S

    2016-09-15

    A new theoretical framework for diurnal and seasonal oscillations of the concentration of radon in soil and open air is proposed. The theory is based on the existing temperature waves in soils and thermo-diffusional gas flux in porous media. As soil is a non-isothermal porous medium, usually possessing a large fraction of microscopic pores belonging to Knudsen's free molecular field, a thermo-diffusional gas flow in soil has to arise. The radon mass transfer equation in soil for sinusoidal temperature oscillations at the soil-atmosphere boundary is solved, which reveals that radon concentration behaves as a damped harmonic wave. The amplitude of radon concentration oscillations and phase shift between radon concentration oscillations and soil temperature depend on the radon diffusion coefficient in soil, rate of radon production, soil thermal conductivity, average soil temperature, decay constant, and heat of radon transfer. Primarily numerical calculations are presented and comparisons with experimental data are shown.

  3. Modelling of radon transport in porous media

    NARCIS (Netherlands)

    van der Graaf, E.R.; de Meijer, R.J.; Katase, A; Shimo, M

    1998-01-01

    This paper aims to describe the state of the art of modelling radon transport in soil on basis of multiphase radon transport equations. Emphasis is given to methods to obtain a consistent set of input parameters needed For such models. Model-measurement comparisons with the KVI radon transport Facil

  4. Modelling of radon transport in porous media

    NARCIS (Netherlands)

    van der Graaf, E.R.; de Meijer, R.J.; Katase, A; Shimo, M

    1998-01-01

    This paper aims to describe the state of the art of modelling radon transport in soil on basis of multiphase radon transport equations. Emphasis is given to methods to obtain a consistent set of input parameters needed For such models. Model-measurement comparisons with the KVI radon transport Facil

  5. Reducing Radon in Schools: A Team Approach.

    Science.gov (United States)

    Ligman, Bryan K.; Fisher, Eugene J.

    This document presents the process of radon diagnostics and mitigation in schools to help educators determine the best way to reduce elevated radon levels found in a school. The guidebook is designed to guide school leaders through the process of measuring radon levels, selecting the best mitigation strategy, and directing the efforts of a…

  6. Soil radon measurements as potential tracer of seismic and volcanic activity at Etna

    Science.gov (United States)

    Neri, Marco; Giammanco, Salvatore; Galli, Gianfranco; Ferrera, Elisabetta

    2014-05-01

    Radon is a radioactive noble gas present in all rocks of the Earth. It's used by the scientific community as a tracer of natural phenomena related to outgassing from the soil along faults, fractures and crustal discontinuity. Recently, radon has also been used on active volcanoes such as Etna, both as a precursor of volcanic phenomena as well as in the study of the dynamics of faults. The Istituto Nazionale di Geofisica e Vulcanologia (INGV) performs discrete and continuous measurements of radon from soil at Etna since 2002. First studies concerned measurements of radon and thoron emissions from soil carried out on the E and SW flanks of Etna, in zones characterized by the presence of numerous seismogenic and aseismic faults. The statistical treatment of the geochemical data allowed recognizing anomaly thresholds, producing distribution maps that highlighted a significant spatial correlation between soil gas anomalies and tectonic lineaments. These studies confirmed that mapping the distribution of radon and thoron in soil gas can reveal hidden faults buried by recent soil cover. INGV permanent radon monitoring network was installed in July 2005. First results were obtained during the July 2006 eruption. The radon signal recorded at Torre del Filosofo (TdF, ~2950 m asl) was compared with volcanic tremor and thermal radiance data. The onset of explosive activity and a lava fountaining episode were preceded by some hours with increases in radon activity and more gradual increases in volcanic tremor. After 2006, Etna produced dozens of paroxysmal episodes from a new vent opened on the eastern flank of the Southeast Crater (summit area), that have built up a new, huge pyroclastic cone. In many cases we observed increase in radon activity some hours before the eruptive events. These observations suggest that radon emissions from the TdF zone are sensitive to the local geodynamic pressure induced by magma dynamics in the conduit systems. Other promising results were

  7. Comparison of radon doses based on different radon monitoring approaches.

    Science.gov (United States)

    Vaupotič, Janja; Smrekar, Nataša; Žunić, Zora S

    2017-04-01

    In 43 places (23 schools, 3 kindergartens, 16 offices and one dwelling), indoor radon has been monitored as an intercomparison experiment, using α-scintillation cells (SC - Jožef Stefan Institute, Slovenia), various kinds of solid state nuclear track detectors (KfK - Karlsruhe Institute of Technology, Germany; UFO - National Institute of Radiological Sciences, Chiba, Japan; RET - University College Dublin, Ireland) and active electronic devices (EQF, Sarad, Germany). At the same place, the radon levels and, consequently, the effective doses obtained with different radon devices differed substantially (by a factor of 2 or more), and no regularity was observed as regards which detector would show a higher or lower dose. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Mutagenicity of radon and radon daughters. Annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Evans, H.H.

    1991-12-01

    The objective of our research is to investigate the dose-response relationship of the lethal and mutagenic effects of exposure of cells to radon and its decay products. Dose rate dependence and the nature of the DNA lesion will be studied, using the thymidine kinase and HPRT loci to measure mutation frequency. A deficiency in DNA repair is shown to lead to a greater proportion of mutants with intergenic lesions. The cytotoxic effects of radon and its daughters are similar in human TK6 lymphoblasts and mouse L5178Y lymphoblasts, the cell line used in previous experiments. The results of molecular analysis of four spontaneous and 25 X-radiation induced HPRT{sup {minus}} mutants. Eleven radon-induced HPRT{sup {minus}} mutants have been isolated, and will be analyzed in a similar fashion. 9 figs.

  9. Discrete Breathers

    CERN Document Server

    Flach, S

    1998-01-01

    Nonlinear classical Hamiltonian lattices exhibit generic solutions in the form of discrete breathers. These solutions are time-periodic and (typically exponentially) localized in space. The lattices exhibit discrete translational symmetry. Discrete breathers are not confined to certain lattice dimensions. Necessary ingredients for their occurence are the existence of upper bounds on the phonon spectrum (of small fluctuations around the groundstate) of the system as well as the nonlinearity in the differential equations. We will present existence proofs, formulate necessary existence conditions, and discuss structural stability of discrete breathers. The following results will be also discussed: the creation of breathers through tangent bifurcation of band edge plane waves; dynamical stability; details of the spatial decay; numerical methods of obtaining breathers; interaction of breathers with phonons and electrons; movability; influence of the lattice dimension on discrete breather properties; quantum lattic...

  10. Instruments to measure radon-222 activity concentration or exposure to radon-222. Intercomparison 2014; Messgeraete zur Bestimmung der Radon-222-Aktivitaetskonzentration oder der Radon-222-Exposition. Vergleichspruefung 2014

    Energy Technology Data Exchange (ETDEWEB)

    Foerster, Elisabeth; Beck, Thomas; Buchroeder, Helmut; Doering, Joachim; Schmidt, Volkmar

    2014-10-15

    According to the Directive 96/29/EURATOM the monitoring of occupational radiation exposures shall base on individual measurements carried out by an approved dosimetric service. Pursuant to the European Directive an approved dosimetric service is a body responsible for the calibration, reading or interpretation of individual monitoring devices.., whose capacity to act in this respect is recognized by the competent authorities. This concept will also be applied to radon services issuing passive radon measurement devices. Passive radon measurement devices{sup 1} using solid state nuclear track detectors or electrets are recommended for individual monitoring of exposures to radon. German regulations lay down that radon measuring devices are appropriate for purposes of occupational radiation monitoring if the devices are issued by recognized radon measurement services, and the measurement service submits devices of the same type issued for radon monitoring to regular intercomparisons conducted by the Bundesamt fuer Strahlenschutz (BfS). A radon measuring service is recognized by the competent authority if it proves its organisational and technical competence, e. g. by accreditation. These regulations have been introduced in the area of occupational radiation exposures. Nevertheless, it is recommended that radon measuring services which carry out radon measurements in other areas (e.g. dwellings) should subject themselves to these measures voluntarily. The interlaboratory comparisons comprise the organization, exposure, and evaluation of measurements of radon activity concentration or exposure to radon. The comparisons only concern radon-222; radon-220 is not in the scope. Radon services being interested can get further information from the European Information System on Proficiency Testing Schemes (EPTIS) and from the BfS websites.

  11. Indoor radon measurements in Turkey dwellings.

    Science.gov (United States)

    Celebi, N; Ataksor, B; Taskın, H; Bingoldag, N Albayrak

    2015-12-01

    In this work, indoor radon radioactivity concentration levels have been measured in dwellings of Turkey within the frame of the National Radon Monitoring Programme. The (222)Rn concentrations were measured with time-integrating passive nuclear etched track detectors in 7293 dwellings in 153 residential units of 81 provinces, and the radon map of Turkey was prepared. Indoor radon concentrations were distributed in the range of 1-1400 Bq m(-3). The arithmetic mean of the radon gas concentration was found to be 81 Bq m(-3); the geometric mean was 57 Bq m(-3) with a geometric standard deviation of 2.3.

  12. Durability of radon remedial actions

    Energy Technology Data Exchange (ETDEWEB)

    Naismith, S. [National Radiological Protection Board, Chilton (United Kingdom)

    1997-10-01

    In the UK, approximately 3600 householders are believed to have taken action to reduce high radon concentrations in their homes. In 1993 a number of those householders who had taken successful remedial actions were invited to participate in a study of durability of radon remedial actions. This involved the radon concentration being remeasured annually. Results for 26 such homes where a complete set of data are available and a further 32 with incomplete data are discussed here. All remedial actions were shown to remain durable during a period of 5 years. The largest variation in effectiveness was found in houses with natural ventilation of the underfloor void. The failure rate for all remedial measures was found to be 4.0% per annum, but in most cases the problems were noticed by the householder and corrected. The frequency of failures which were not noticed until a remeasurement was carried out was 0.4% per annum. (Author).

  13. Attenuated radon transform: theory and application in medicine and biology

    Energy Technology Data Exchange (ETDEWEB)

    Gullberg, G.T.

    1979-06-01

    A detailed analysis is given of the properties of the attenuated Radon transform and of how increases in photon attenuation influence the numerical accuracy and computation efficiency of iterative and convolution algorithms used to determine its inversion. The practical applications for this work involve quantitative assessment of the distribution of injected radiopharmaceuticals and radionuclides in man and animals for basic physiological and biochemical studies as well as clinical studies in nuclear medicine. A mathematical structure is developed using function theory and the theory of linear operators on Hilbert spaces which lends itself to better understanding the spectral properties of the attenuated Radon transform. The continuous attenuated Radon transform reduces to a matrix operator for discrete angular and lateral sampling, and the reconstruction problem reduces to a system of linear equations. For the situation of variable attenuation coefficient frequently found in nuclear medicine applications of imaging the heart and chest, the procedure developed in this thesis involves iterative techniques of performing the generalized inverse. For constant attenuation coefficient less than 0.15 cm/sup -1/, convolution methods can reliably reconstruct a 30 cm object with 0.5 cm resolution. However, for high attenuation coefficients or for the situation where there is variable attenuation such as reconstruction of distribution of isotopes in the heart, iterative techniques developed in this thesis give the best results. (ERB)

  14. Thermo-diffusional radon waves in soils

    Energy Technology Data Exchange (ETDEWEB)

    Minkin, Leonid, E-mail: lminkin@pcc.edu [Portland Community College, 12000 SW 49th Ave, Portland, OR 97219 (United States); Shapovalov, Alexander S. [Saratov State University, 83 Astrakhanskay Street, Saratov 410012 (Russian Federation)

    2016-09-15

    A new theoretical framework for diurnal and seasonal oscillations of the concentration of radon in soil and open air is proposed. The theory is based on the existing temperature waves in soils and thermo-diffusional gas flux in porous media. As soil is a non-isothermal porous medium, usually possessing a large fraction of microscopic pores belonging to Knudsen's free molecular field, a thermo-diffusional gas flow in soil has to arise. The radon mass transfer equation in soil for sinusoidal temperature oscillations at the soil–atmosphere boundary is solved, which reveals that radon concentration behaves as a damped harmonic wave. The amplitude of radon concentration oscillations and phase shift between radon concentration oscillations and soil temperature depend on the radon diffusion coefficient in soil, rate of radon production, soil thermal conductivity, average soil temperature, decay constant, and heat of radon transfer. Primarily numerical calculations are presented and comparisons with experimental data are shown. - Highlights: • Temperature oscillations in atmosphere generate radon waves in soil. • Radon flux in atmosphere is a harmonic function of time. • Radon concentration waves in soil have the same frequency as the temperature waves.

  15. 30 CFR 57.5046 - Protection against radon gas.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Protection against radon gas. 57.5046 Section... Protection against radon gas. Where radon daughter concentrations exceed 10 WL, respirator protection against radon gas shall be provided in addition to protection against radon daughters. Protection against...

  16. XENON1T radon assay

    Energy Technology Data Exchange (ETDEWEB)

    Bruenner, Stefan [MPIK, Heidelberg (Germany); Collaboration: XENON-Collaboration

    2016-07-01

    The radioactive isotope {sup 222}Rn is one of the most dominant intrinsic background sources for experiments dealing with a low event rate like the XENON1T Dark Matter detector. Being part of the primordial decay chain of {sup 238}U the noble gas {sup 222}Rn permanently emanates from almost all materials. Therefore, it is crucial to determine the radon emanation rate of those detector components that will be in contact with the xenon target. The technique of the radon emanation measurements, making use of ultra low background proportional counters is presented as well as selected results for XENON1T.

  17. Radon monitoring and hazard prediction in Ireland

    Science.gov (United States)

    Elio, Javier; Crowley, Quentin; Scanlon, Ray; Hodgson, Jim; Cooper, Mark; Long, Stephanie

    2016-04-01

    Radon is a naturally occurring radioactive gas which forms as a decay product from uranium. It is the largest source of natural ionizing radiation affecting the global population. When radon is inhaled, its short-lived decay products can interact with lung tissue leading to DNA damage and development of lung cancer. Ireland has among the highest levels of radon in Europe and eighth highest of an OECD survey of 29 countries. Every year some two hundred and fifty cases of lung cancer in Ireland are linked to radon exposure. This new research project will build upon previous efforts of radon monitoring in Ireland to construct a high-resolution radon hazard map. This will be achieved using recently available high-resolution airborne gamma-ray spectrometry (radiometric) and soil geochemistry data (http://www.tellus.ie/), indoor radon concentrations (http://www.epa.ie/radiation), and new direct measurement of soil radon. In this regard, legacy indoor radon concentrations will be correlated with soil U and Th concentrations and other geogenic data. This is a new approach since the vast majority of countries with a national radon monitoring programme rely on indoor radon measurements, or have a spatially limited dataset of soil radon measurements. Careful attention will be given to areas where an indicative high radon hazard based on geogenic factors does not match high indoor radon concentrations. Where such areas exist, it may imply that some parameter(s) in the predictive model does not match that of the environment. These areas will be subjected to measurement of radon soil gas using a combination of time averaged (passive) and time dependant (active) measurements in order to better understand factors affecting production, transport and accumulation of radon in the natural environment. Such mapping of radon-prone areas will ultimately help to inform when prevention and remediation measures are necessary, reducing the radon exposure of the population. Therefore, given

  18. Discrete Stein characterizations and discrete information distances

    CERN Document Server

    Ley, Christophe

    2012-01-01

    We construct two different Stein characterizations of discrete distributions and use these to provide a natural connection between Stein characterizations for discrete distributions and discrete information functionals.

  19. 76 FR 72006 - Draft Interim Staff Guidance: Evaluations of Uranium Recovery Facility Surveys of Radon and Radon...

    Science.gov (United States)

    2011-11-21

    ... COMMISSION Draft Interim Staff Guidance: Evaluations of Uranium Recovery Facility Surveys of Radon and Radon... Recovery Facility Surveys of Radon and Radon Progeny in Air and Demonstrations of Compliance with 10 CFR 20... that existing guidance does not sufficiently detail how the NRC staff reviews surveys of radon and...

  20. Discrete Mathematics

    DEFF Research Database (Denmark)

    Sørensen, John Aasted

    2010-01-01

    The introduction of the mathematics needed for analysis, design and verification of discrete systems, including applications within programming languages for computer systems. Course sessions and project work. Semester: Spring 2010 Ectent: 5 ects Class size: 18......The introduction of the mathematics needed for analysis, design and verification of discrete systems, including applications within programming languages for computer systems. Course sessions and project work. Semester: Spring 2010 Ectent: 5 ects Class size: 18...

  1. Discrete Mathematics

    DEFF Research Database (Denmark)

    Sørensen, John Aasted

    2010-01-01

    The introduction of the mathematics needed for analysis, design and verification of discrete systems, including applications within programming languages for computer systems. Course sessions and project work. Semester: Autumn 2010 Ectent: 5 ects Class size: 15......The introduction of the mathematics needed for analysis, design and verification of discrete systems, including applications within programming languages for computer systems. Course sessions and project work. Semester: Autumn 2010 Ectent: 5 ects Class size: 15...

  2. Efficacy of radon remedial measures

    Energy Technology Data Exchange (ETDEWEB)

    Naismith, S. (National Radiological Protection Board, Chilton (United Kingdom))

    1994-04-01

    About 2000 householders in the UK have taken remedial action to reduce high radon levels in their homes. Some 800 of these householders have sought measurements to confirm the effectiveness of the action. Results for 528 such homes are discussed. (author).

  3. Low Radon Cleanroom at the University of Alberta

    Science.gov (United States)

    Grant, Darren; Hallin, Aksel; Hanchurak, Stephen; Krauss, Carsten; Liu, Shengli; Soluk, Richard

    2011-04-01

    A cleanroom laboratory designed to create and maintain a low concentration of radon in the air has been designed and is now under construction. We describe the clean room, the radon stripping system, and various radon monitoring tools.

  4. 9th Saxonian radon day. 11th meeting on radon safe structural engineering; 9. Saechsischer Radontag. 11. Tagung radonsicheres Bauen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-07-01

    The proceedings of the meeting in radon-safe structural engineering covers contributions on the following issues: implementation of the EU standards, radon protection in underground cavities, radon protection at working places, reports on experiences.

  5. Study on the solubility of radon in tissues; Untersuchung der Loeslichkeit von Radon in Gewebe

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, Claudia; Kraft, Gerhard; Maier, Andreas; Beek, Patrick van [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany)

    2016-08-01

    At the GSI Helmholtz Center in Darmstadt a radon chamber with conditions similar to the radon galleries was built for studies on the solubility of radon in tissues using cell cultures and animals. The samples are investigated using gamma spectroscopy following the radon exposure measuring Pb-214 and Bi-214. The original concentration of Rn-222 in the sample is determined by the time dependence of the decay rates of Rn-222. The experimental conditions and preliminary measurements are described.

  6. A European-wide 222Radon and 222Radon progeny comparison study

    OpenAIRE

    Schmithüsen, Dominik; Chambers, Scott; Fischer, Bernd; Gilge, Stefan; Hatakka, Juha; Kazan, Victor; Neubert, Rolf; Paatero, Jussi; Ramonet, Michel; Schlosser, Clemens; Schmid, Sabine; Vermeulen, Alex; Levin, Ingeborg

    2016-01-01

    A European-wide 222Radon/222Radon progeny comparison study has been conducted in order to determine correction factors that could be applied to existing atmospheric 222Radon data sets for quantitative use of this tracer in atmospheric transport model validation. Two compact and easy-to-transport Heidelberg Radon Monitors (HRM) were moved around to run for at least one month at each of the nine European measurement stations that were included in the comparison. Linear regressions between paral...

  7. Fast Mojette Transform for Discrete Tomography

    CERN Document Server

    Chandra, Shekhar S; Kingston, Andrew; Guédon, Jeanpierre; Svalbe, Imants

    2010-01-01

    A new algorithm for reconstructing a two dimensional object from a set of one dimensional projected views is presented that is both computationally exact and experimentally practical. The algorithm has a computational complexity of O(n log2 n) with n = N^2 for an NxN image, is robust in the presence of noise and produces no artefacts in the reconstruction process, as is the case with conventional tomographic methods. The reconstruction process is approximation free because the object is assumed to be discrete and utilizes fully discrete Radon transforms. Noise in the projection data can be suppressed further by introducing redundancy in the reconstruction. The number of projections required for exact reconstruction and the response to noise can be controlled without comprising the digital nature of the algorithm. The digital projections are those of the Mojette Transform, a form of discrete linogram. A simple analytical mapping is developed that compacts these projections exactly into symmetric periodic slice...

  8. The radon: evaluation and risk management; Le radon: evaluation et gestion du risque

    Energy Technology Data Exchange (ETDEWEB)

    Lacoste, A.C. [Direction Generale de la Surete Nucleaire et de la Radioprotection, 75 - Paris (France); Masse, R. [Academie des Technologies, 75 - Paris (France); Aurengo, A. [Hopital Pitie-Salpetriere, Service de Medecine Nucleaire, 75 - Paris (France); Erich Wichmann, H. [Neuberberg Munich Univ. (Germany); Timarche, M.; Laurier, D.; Robe, M.Ch. [Institut de Radioprotection et de Surete Nucleaire (IRSN), 92 - Clamart (France); Baubron, J.C.; Bonijoly, D. [BRGM, 75 - Paris (France); Collignan, B. [Centre Scientifique et Technique du Batiment, (CSTB), 75 - Paris (France); Berrier, H. [Direction Gle de l' Urbanisme de l' Habitat et de la Construction, 75 - Paris (France); Jaouen, J. [Direction Departementale des Affaires Sanitaires et Sociales de la Haute-Vienne (France); Caamano, D. [Direction Departementale des Affaires Sanitaires et Sociales de l' Essonne, 91 (France); Guiot, F. [Direction Departementale des Affaires Sanitaires et Sociales de la Haute-Marne (France); Grall, B. [Direction Departementale des Affaires Sanitaires et Sociales de Bretagne (France); Frutos Vasquez, B.; Olaya Adan, M. [Istituto de Ciencias de la Construction (Italy); Garcia Cadierno, J.P.; Martin Matarranz, J.L.; Serrano Renedo, J.; Suarez Mahou, E. [Consejo de Seguridad Nuclear, Madrid (Spain); Fernandez, J.A. [ENUSA Industrias Avanzadas (Spain); Mjones, L.; Pirard, P. [Institut de veille sanitaire, 94415 - Saint-Maurice (France); Godet, J.L.; Rougy, Ch. [Direction Gle de la Surete Nucleaire et de la Radioprotection, 75 - Paris (France)

    2003-06-15

    The radon exposure constitutes for the French population the first cause of natural irradiation among the different natural sources of irradiation. It is possible to have a significant action on it, either by making draught proof in order to avoid to radon to get inside houses, either by ventilating in order to dispel the radon and improve air quality. (N.C.)

  9. Radon concentration measurements in bituminous coal mines.

    Science.gov (United States)

    Fisne, Abdullah; Okten, Gündüz; Celebi, Nilgün

    2005-01-01

    Radon measurements were carried out in Kozlu, Karadon and Uzülmez underground coal mines of Zonguldak bituminous coal basin in Turkey. Passive-time integrating method, which is the most widely used technique for the measurement of radon concentration in air, was applied by using nuclear etched track detectors (CR-39) in the study area. The radon concentration measurements were performed on a total of 42 points in those three mines. The annual exposure, the annual effective dose and lifetime fatality risk, which are the important parameters for the health of workers, were estimated based on chronic occupational exposure to the radon gas, which is calculated using UNCEAR-2000 and ICRP-65 models. The radon concentrations at several coal production faces are higher than the action level of 1000 Bq m(-3). It is suggested that the ventilation rates should be rearranged to reduce the radon concentration.

  10. Radix Representation of Triangular Discrete Grid System

    Science.gov (United States)

    Ben, J.; Li, Y. L.; Wang, R.

    2016-11-01

    Discrete Global Grid Systems (DGGSs) are spatial references that use a hierarchical tessellation of cells to partition and address the entire globe. It provides an organizational structure that permits fast integration between multiple sources of large and variable geospatial data. Although many endeavors have been done to describe certain discrete grid systems, there still lack of a uniform mathematical framework for them. This paper simplifies the planar class I aperture 4 triangular discrete grid system into a hierarchical lattice model which is proved to be a radix system in the complex number plane. Mathematical properties of the radix system reveal the discrete grid system is equivalent to the set of complex numbers with special form. The conclusion provides a potential way to build a uniform mathematical framework of DGGS and can be used to design efficient encoding and spatial operation scheme for DGGS.

  11. Discrete Chaos

    CERN Document Server

    Waelbroeck, H

    1999-01-01

    We propose a theory of deterministic chaos for discrete systems, based on their representations in symbolic history spaces Ømega. These are spaces of semi-infinite sequences, as the one-sided shift spaces, but endowed with a more general topology which we call a semicausal topology. We show that define metrical properties, including the correlation dimension of the attractor. Examples are considered: Asymmetric neural networks and random cellular automata are not chaotic. A neural network model with memory, on the other hand, does appear to be an example of discrete chaos.

  12. Discrete mechanics

    CERN Document Server

    Caltagirone, Jean-Paul

    2014-01-01

    This book presents the fundamental principles of mechanics to re-establish the equations of Discrete Mechanics. It introduces physics and thermodynamics associated to the physical modeling.  The development and the complementarity of sciences lead to review today the old concepts that were the basis for the development of continuum mechanics. The differential geometry is used to review the conservation laws of mechanics. For instance, this formalism requires a different location of vector and scalar quantities in space. The equations of Discrete Mechanics form a system of equations where the H

  13. Territorial discretion

    Directory of Open Access Journals (Sweden)

    Augusto Hernández Vidal

    2011-12-01

    Full Text Available In order to strengthen the concept of municipal autonomy, this essay proposes an extensive interpretation of administrative discretion. Discretion is the exercise of free judgment given by law to authorities for performing official acts. This legislative technique seems to be suitable whenever the legislative is intended to legislate over the essential core of municipal autonomy. This way, an eventual abuse of that autonomy could be avoided, for the disproportional restriction of the local faculty to oversee the local issues. This alternative is presented as a tool to provide with dynamism the performing of administrative activities as well, aiming to assimilate public administration new practices.

  14. A perspective on risks from radon

    Energy Technology Data Exchange (ETDEWEB)

    Higson, D. J., E-mail: higsond@bigpond.net.a [Australasian Radiation Protection Society, PO Box 7108, Upper Ferntree Gully, Victoria 3156 (Australia)

    2010-10-15

    In its Statement on Radon (November 2009), the International Commission on Radiological Protection (ICRP) has reduced the upper reference level for radon gas in dwellings to 300 Bq m{sup -3}. The recommended level for workplaces is 1000 Bq m{sup -3}. A risk coefficient of 8 x 10{sup -10} per Bq h m{sup -3} is recommended without reference to smoking habits. On the basis of these figures: 1) The estimated risk of fatal cancer from exposure to radon at home and at work could be greater than the observed risk of accidental death from travelling by car, which would be surprising if true. 2) The estimated risk of lung cancer from radon could be greater than the observed risk of lung cancer from all causes, which is actually known to be dominated by smoking. The author is not aware of any direct evidence of risks from inhaling radon in Australian dwellings, 99% of which have radon levels below 50 Bq m{sup -3}. Evidence available from other countries shows that: 1) The effects of radon in the incidences of lung cancer are uncertain at levels less then about 50-100 Bq m{sup -3}. 2) The estimation of risks at levels below 200 Bq m{sup -3} depends on extrapolation from risks observed at higher levels. 3) Risks to non-smokers from radon are 25 times less than risks to smokers. Its concluded that the ICRP Statement on Radon and radon policies in the US and UK have the potential to cause unwarranted concern. Some people may be made to feel they need to spend money modifying their homes and workplaces to protect occupants from exposure to radon when there is no compelling reason to show that this is necessary. The vast majority of non-smokers do not need to be protected from radon. (Author)

  15. The radon influence of SAGE results

    CERN Document Server

    Gavrin, V N; Mirmov, I N

    2002-01-01

    The method for evaluating systematic errors, connected with radon, is described in the experiment on determining the SAGE solar neutrino flux. The systematic error by the measured neutrino capture rate in the gallium 75 SNU target does not exceed 0.3 SNU. The obtained value (0.3 SNU) is the upper limit of the radon systematic error. Its low value means, that radon does not contribute significantly to the SAGE result

  16. A Fuzzy Radon Transform for Track Recognition

    CERN Document Server

    De Laat, C T A M; CERN. Geneva; Lourens, W; Kamermans, R

    1993-01-01

    In this contribution a fuzzy Radon transform is shown for application in ALICE and ATLAS (typical track density of 8000 in one unit of rapidity). Resolution is introduced by the "broadening" of the matching tracks in the Radon transform, which is obtained by making a convolution of the matching tracks with Gaussian kernel. In a good approximation, an analytical expression for the fuzzy Radon transform is given. An example of two track separation with noisy input is added.

  17. Radon atlas of Finland; Suomen radonkartasto

    Energy Technology Data Exchange (ETDEWEB)

    Voutilainen, A.; Maekelaeinen, I.; Pennanen, M.; Reisbacka, H.; Castren, O.

    1997-11-01

    The most efficient means of reducing indoor radon exposure is to locate and mitigate dwellings with radon concentration exceeding the action level of 400 Bq/m{sup 3} and to build new houses so that radon concentrations do not exceed 200 Bq/m{sup 3}. The maps and tables in this report are useful tools for those who plan and decide what kind of radon mitigation measures are needed in municipalities. STUK (The Radiation and Nuclear Safety Authority) has an indoor radon database of 52 000 dwellings, for which the indoor radon concentration and construction details are known. The building site soil type of about 38 000 dwellings is known. This atlas is a summary of all indoor radon measurements made by STUK in lowrise dwellings and in first-floor flats. The results are shown as arithmetic means of 5- or 10-km squares on maps of the provinces. Three radon maps have been made for each province. On one map the data consist of all measurements the position coordinates of which are known. On the two other maps the building sites of houses are classified into permeable and low-permeable soil types. The tables show statistics for all indoor radon measurements by municipality and building site soil type. (orig.). 11 refs. The publication contains all texts both in Finnish and in English.

  18. Radon in Himalayan springs: a geohydrological control

    Energy Technology Data Exchange (ETDEWEB)

    Choubey, V.M.; Bartarya, S.K. [Wadia Inst. of Himalayan Geology, Dehra Dun (India); Ramola, R.C. [Garhwal Univ., Srinagar, Uttar Pradesh (India). Dept. of Physics

    2000-04-01

    This paper presents the results of radon measurements in springs of the Himalayan region by using radon emanometry technique. The radon was measured in different springs, draining from different geohydrological setups, and from stream water in order to find the geohydrological control over radon concentration in groundwater emanating in the form of spring. The radon values were found to vary from 0.4 Bq/l to 887 Bq/l, being observed lowest for a turbulent stream and highest for the spring. The radon values were recorded highest in the springs draining through gneiss, granite, mylonite, etc. Radon concentrations have been related with four spring types viz. fracture-joint related spring, fault-lineament related spring, fluvial related spring and colluvial related spring, showing geohydrological characteristics of the rocks through which they are emanating. The high radon concentration in fracture-joint and fault-lineament springs is related to increased ratio of rock surface area to water volume and uranium mineralisation in the shear zones present in the close vicinity of fault and thrust. The low concentration of radon in fluvial and colluvial springs is possibly because of high transmissivity and turbulent flow within such deposits leading to natural de-emanation of gases. (orig.)

  19. Radon transfer and intracorporal deposition of radon decay products under balneotherapeutic conditions; Radon-Transfer und intrakorporale Deposition von Radon-Folgeprodukten unter balneotherapeutischen Bedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Grunewald, Wolfgang A. [Kurmittelhaus Sibyllenbad, Neualbenreuth (Germany); Just, Guenther [Forschungsbuero Radon, Grosspoesna (Germany); Petzold, Juergen [Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum, Leipzig (Germany); Philipsborn, Henning von [Radiometrisches Seminar, Univ. Regensburg (Germany)

    2009-07-01

    The intracorporal deposition of radon decay products was determined on four persons after 40 and 30 min respectively in radon water with about 1500 Bq/L by whole-body gamma spectrometry. The measurements started about 2 1/2h after exposure. In addition, the radon activity concentration of inspiratory and expiratory air was measured on one person during and after exposure and the deposition of radon decay products on the skin was measured on another person. The radon activity leaving the body with the expiratory air during exposure in the water (called ''radon transfer'') amounts to about 800 Bq. An intracorporal radon activity immediately after therapeutic exposure of about 3000 Bq was obtained as a result of first measurements by extrapolation from measurements starting about 2 1/2 hours later. Additional studies are necessary. There are indications that both the radon transfer and the intracorporal deposition can be increased by exposure in mixed radon-CO{sub 2} water. (orig.)

  20. Low-Cost Radon Reduction Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    Rose, William B. [Partnership for Advanced Residential Retrofit, Champaign, IL (United States); Francisco, Paul W. [Partnership for Advanced Residential Retrofit, Champaign, IL (United States); Merrin, Zachary [Partnership for Advanced Residential Retrofit, Champaign, IL (United States)

    2015-09-01

    The aim of the research was to conduct a primary scoping study on the impact of air sealing between the foundation and the living space on radon transport reduction across the foundation-living space floor assembly. Fifteen homes in the Champaign, Illinois area participated in the study. These homes were instrumented for hourly continuous radon measurements and simultaneous temperature and humidity the foundation was improved. However, this improved isolation did not lead to significant reductions in radon concentration in the living space. Other factors such as outdoor temperature were shown to have an impact on radon concentration.

  1. Durability of radon remedial actions

    Energy Technology Data Exchange (ETDEWEB)

    Naismith, S. [National Radiological Protection Board, Chilton (United Kingdom)

    1997-07-01

    It is estimated that at least 3600 householders in the UK have taken remedial action to reduce radon concentrations found to be above the government Action Level. A study has been carried out on the durability of these remedial actions. It involved annual reassessment of the radon levels in a number of homes. The results for 26 of these homes where data over five years are available show that in general the remedial actions remained effective. The remedy with the largest variation in efficacy was natural ventilation of the underfloor void. The failure rate was found to be 4.0% per annum for all measures, but in the majority of cases the failure was discovered by the householder and rectified. The rate of failures not noticed by the householders was 0.4% per annum. (UK).

  2. Radon as an Anthropogenic Indoor Air Pollutant

    Science.gov (United States)

    Gillmore, Gavin; Crockett, Robin

    2016-04-01

    Radon is generally regarded as a naturally occurring radiological hazard but we report here measurements of significant, hazardous radon concentrations that arise from man-made sources, including granite ornaments/artefacts, uranium glass and glazed objects as well radium dial watches. This presentation concerns an examination and assessment of health risks from radium and uranium found in historical artefacts, many of which were once viewed as everyday items, and the radon that emanates from them. Such objects were very popular in industrialised countries such as the USA, UK and European countries) particularly between and including the two World Wars but are still readily available. A watch collection examined gave rise to a hazardous radon concentration of 13.24 kBq•m-3 approximately 67 times the Domestic Action Level of 200 Bq•m-3.The results for an aircraft altimeter are comparable to those of the watches, indicating radon activity equivalent to several watches, and also indicate an equilibrium concentration in the 16.3 m3 room ca. 33 times the UK domestic Action Level. Results from a granite block indicate a radon emanation of 19.7 Bq•kg-1, but the indicated equilibrium concentration in the 16.3 m3 room is only ca. 1.7% of the UK domestic Action Level. Uranium-glazed crockery and green uranium glass were scoped for radon activity. The former yielded a radon concentration of ca. 44 Bq•m-3 in a small (7 L) sealed container. The latter yielded a lower radon concentration in a larger (125 L) sealed container of ca. 6 Bq•m-3. This is barely above the background radon concentration in the laboratory, which was typically ca. 1-2 Bq•m-3. Individual items then are capable of giving rise to radon concentrations in excess of the UK Domestic Action Level in rooms in houses, particularly if poorly ventilated. We highlight the gap in the remediation protocols, which are focused on preventing radon entering buildings from outside, with regard to internally

  3. Current state of radon chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Avrorin, V.V.; Krasikova, R.N.; Nefedov, V.D.; Toropova, M.A.

    1982-01-01

    This article summarizes the data available prior to May 1980 on the physical, chemical and radioactive properties of radon. Tables include a list of the known isotopes together with the half-lives, types of emitted radiation and daughter products and a list of the inert gases Rn, Xe, Kr, Ar and Ne together with the hydrate stability, ionization potential, ionic character of bonding, dissociation energy, electronegativity and others. Experimental difficulties of working with radon, such as its short half-life and its fugitive nature, are mentioned. The compound RNF/sub 2/ can be prepared from several different fluorinating reagents such as ClF/sub 3/, KrF/sub 3/, BrF/sub 3/, K/sub 2/NiF/sub 6/ in HF and others. Until now it has not been possible to prepare organic compounds of inert gases using classical techniques. Noble gas compounds may also be prepared via radiochemical techniques. Some applications of radon compounds, such as in decontamination of reactor and mine effluents, are discussed.

  4. Radon in homes of the Portland, Oregon Area: Radon data from local radon testing companies collected by CRM (Continuous Radon Measurement) machines

    Science.gov (United States)

    Whitney, H.; Lindsey, K.; Linde, T.; Burns, S. F.

    2013-12-01

    Students from the Department of Geology at Portland State University paired up with the Oregon Health Authority to better understand radon gas values in homes of the Portland metropolitan area. This study focuses on radon values collected by continuous radon measurement (CRM) machines, taken by local radon testing companies. The local companies participating in this study include Alpha Environmental Services, Inc., Cascade Radon, Environmental Works, The House Detectives, LLC, and Soil Solutions Environmental Services, Inc. In total, 2491 radon readings spanning across 77 zip codes were collected from local companies in the Portland metropolitan area. The maximum value, average value, percentage of homes greater than 4 pCi/L and total rank sum was calculated and used to determine the overall radon potential for each zip code (Burns et al., 1998). A list and four maps were produced showing the results from each category. Out of the total records, 24 zip codes resulted in high radon potential and the average reading for the entire Portland Metropolitan area was 3.7 pCi/L. High potential zip codes are thought to be a result of sand and gravel (Missoula Flood deposits) and faults present in the subsurface. The CRM data was compared with both long-term and short-term data provided by the Oregon Health Authority to validate radon potentials in each zip code. If a home is located in a zip code with high or moderate radon potential across two types of data sets, it is recommended that those homes be tested for radon gas.

  5. Discrete Mathematics

    DEFF Research Database (Denmark)

    Sørensen, John Aasted

    2011-01-01

    examples on regular languages. Apply these concepts to new problems. Finite state machines: Define a finite state machine as a 6-tuble; describe simple finite state machines by tables and graphs; pattern recognition by finite state machines; minimizing the number of states in a finite state machine......The objectives of Discrete Mathematics (IDISM2) are: The introduction of the mathematics needed for analysis, design and verification of discrete systems, including the application within programming languages for computer systems. Having passed the IDISM2 course, the student will be able...... of natural numbers. Apply these concepts to new problems. Division and factorizing: Define a prime number and apply Euclid´s algorithm for factorizing an integer. Regular languages: Define a language from the elements of a set; define a regular language; form strings from a regular language; construct...

  6. A statistical evaluation of the influence of housing characteristics and geogenic radon potential on indoor radon concentrations in France.

    Science.gov (United States)

    Demoury, C; Ielsch, G; Hemon, D; Laurent, O; Laurier, D; Clavel, J; Guillevic, J

    2013-12-01

    Radon-222 is a radioactive natural gas produced by the decay of radium-226, known to be the main contributor to natural background radiation exposure. Effective risk management needs to determine the areas in which the density of buildings with high radon levels is likely to be highest. Predicting radon exposure from the location and characteristics of a dwelling could also contribute to epidemiological studies. Beginning in the nineteen-eighties, a national radon survey consisting in more than 10,000 measurements of indoor radon concentrations was conducted in French dwellings by the Institute for Radiological Protection and Nuclear Safety (IRSN). Housing characteristics, which may influence radon accumulation in dwellings, were also collected. More recently, the IRSN generated a French geogenic radon potential map based on the interpretation of geological features. The present study analyzed the two datasets to investigate the factors influencing indoor radon concentrations using statistical modeling and to determine the optimum use of the information on geogenic radon potential that showed the best statistical association with indoor radon concentration. The results showed that the variables associated with indoor radon concentrations were geogenic radon potential, building material, year of construction, foundation type, building type and floor level. The model, which included the surrounding geogenic radon potential (i.e. the average geogenic radon potential within a disc of radius 20 km centered on the indoor radon measurement point) and variables describing house-specific factors and lifestyle explained about 20% of the overall variability of the logarithm of radon concentration. The surrounding geogenic radon potential was fairly closely associated with the local average indoor radon concentration. The prevalence of exposure to radon above specific thresholds and the average exposures to radon clearly increased with increasing classes of geogenic radon

  7. Find a Radon Test Kit or Measurement and Mitigation Professional

    Science.gov (United States)

    Find a qualified radon service professional to fix or mitigate your home. If you have questions about a radon, you should contact your state radon contact and/or contact one or both of the two privately-run National Radon Proficiency Programs

  8. Systematic radon survey over active volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, J.L.; Monnin, M.; Garcia Vindas, J.R. [Centre National de la Recherche Cientifique, Montpellier (France). Lab. GBE; Ricard, L.P.; Staudacher, T. [Observatoire Volcanologique Du Pitou de la Fournaise, La Plaine des Cafres (France)

    1999-08-01

    Data obtained since 1993 on Costa Rica volcanos are presented and radon anomalies recorded before the eruption of the Irazu volcano (December 8, 1994) are discussed. The Piton de la Fournaise volcano is inactive since mid 1992. The influence of the external parameters on the radon behaviour is studied and the type of perturbations induced on short-term measurements are individuate.

  9. Radon Measurements in Schools: An Interim Report.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC. Office of Radiation Programs.

    Radon-222 is a colorless, odorless, tasteless, radioactive gas that occurs naturally in soil, rocks, underground water, and air. The United States Environmental Protection Agency (EPA) and other scientific organizations have identified an increased risk of lung cancer associated with exposure to elevated levels of radon in homes. Schools in many…

  10. Domestic Radon and Childhood Cancer in Denmark

    DEFF Research Database (Denmark)

    Raaschou-Nielsen, Ole; Andersen, Claus Erik; Andersen, Helle P.

    2008-01-01

    Background: Higher incidence rates of childhood cancer and particularly leukemia have been observed in regions with higher radon levels, but case-control studies have given inconsistent results. We tested the hypothesis that domestic radon exposure increases the risk for childhood cancer. Methods...

  11. Removal of Radon from Household Water.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC. Office of Research and Development.

    By far, the greatest risk to health from radon occurs when the gas enters the house from underlying soil and is inhaled. The U.S. Environmental Protection Agency (EPA) is studying ways to reduce radon in houses, including methods to remove the gas from water to prevent its release in houses when the water is used. While this research has not…

  12. Radon Risk Communication Strategies: A Regional Story.

    Science.gov (United States)

    Cheng, Winnie

    2016-01-01

    Risk communication on the health effects of radon encounters many challenges and requires a variety of risk communication strategies and approaches. The concern over radon exposure and its health effects may vary according to people's level of knowledge and receptivity. Homeowners in radon-prone areas are usually more informed and have greater concern over those not living in radon-prone areas. The latter group is often found to be resistant to testing. In British Columbia as well as many other parts of the country, some homes have been lying outside of the radon-prone areas have radon levels above the Canadian guideline, which is the reason Health Canada recommends that all homes should be tested. Over the last five years, the Environment Health Program (EHP) of Health Canada in the British Columbia region has been using a variety of different approaches in their radon risk communications through social media, workshops, webinars, public forums, poster contests, radon distribution maps, public inquiries, tradeshows and conference events, and partnership with different jurisdictions and nongovernmental organizations. The valuable lessons learned from these approaches are discussed in this special report.

  13. Radon Measurement in Schools. Revised Edition.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC.

    The Environmental Protection Agency (EPA) and other major national and international scientific organizations have concluded that radon is a human carcinogen and a serious environmental health problem. The EPA has conducted extensive research on the presence and measurement of radon in schools. This report provides school administrators and…

  14. Radon Reduction Methods: A Homeowner's Guide.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC.

    The U.S. Environmental Protection Agency (EPA) is studying the effectiveness of various ways to reduce high concentrations of radon in houses. This booklet was produced to share what has been learned with those whose radon problems demand immediate action. The booklet describes nine methods that have been tested successfully--by EPA and/or other…

  15. On discrete fractional integral operators and related Diophantine equations

    CERN Document Server

    Kim, Jongchon

    2011-01-01

    In this paper we show that an arithmetic property of a hypersurface in $\\zn{k+1}$ (a map $\\gamma:\\zn{k} \\to \\mathbb{Z}$) gives $l^p \\to l^q$ bounds of a Radon-type discrete fractional integral operator along the hypersurface. As a corollary, we prove $l^p \\to l^q$ bounds of a Radon-type discrete fractional integral operator along paraboloids in $\\zn{3}$ and some other related operators. As a by-product of this approach, we show that the statement $r_{s,k}(N) = O(N^\\epsilon)$ for any $\\epsilon>0$ is false if $s>k$, where $r_{s,k}(N)$ denotes the number of representations of a positive integer $N$ as a sum of s positive $k$-th powers.

  16. Measurements of radon around closed uranium mines

    Energy Technology Data Exchange (ETDEWEB)

    Furuta, Sadaaki E-mail: furuta@ningyo.jnc.go.jp; Ito, Kimio; Ishimori, Yuu

    2002-07-01

    There are several waste rock yards at closed uranium mines around Ningyo-toge, in the Western Honshu Island of Japan, and measurements of radon were carried out by both the passive method and the sampling method around these yards. As comparatively high radon concentrations were observed in two districts through routine measurements, more detailed measurements were made by the passive method in these districts. The impact of radon emanation from the waste rock yards was small for both residential districts and around these yards when considering the natural background level of radon. In addition, by simultaneous continuous measurements of radon and its progeny at two locations, it was estimated that the effective dose caused by the representative uranium waste rock yards was less than the public effective dose limit of 1 mSv year{sup -1} at the fenced boundary of the waste rock site.

  17. Indoor radon survey in the Vojvodina region

    Energy Technology Data Exchange (ETDEWEB)

    Forkapic, S.; Todorovic, N.; Bikit, I.; Mrda, D.; Slivka, J.; Veskovic, M. [Department of Physics, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 4, 21000 Novi Sad (Serbia)

    2010-07-01

    The results of an indoor radon survey in the Vojvodina region (Serbia) are presented. Long-term average radon measurements in an existing building can be measured relatively simply and inexpensively using a passive device, such as an alpha track detector. Houses in the suburbs were chosen as the target locations of the present investigations. Indoor radon concentrations were measured with CR-39 alpha track detectors at {approx}1000 locations in Vojvodina during the winter period. Effect of floor level, space under the rooms, boarding and the heating system on radon accumulation are discussed in this paper. For the dwellings typical of such regions, we measure a mean annual radon activity concentration of 112 Bq/m{sup 3} (747 measurements using the alpha track detector CR-39). (authors)

  18. Indoor radon risk potential of Hawaii

    Science.gov (United States)

    Reimer, G.M.; Szarzi, S.L.

    2005-01-01

    A comprehensive evaluation of radon risk potential in the State of Hawaii indicates that the potential for Hawaii is low. Using a combination of factors including geology, soils, source-rock type, soil-gas radon concentrations, and indoor measurements throughout the state, a general model was developed that permits prediction for various regions in Hawaii. For the nearly 3,100 counties in the coterminous U.S., National Uranium Resource Evaluation (NURE) aerorad data was the primary input factor. However, NURE aerorad data was not collected in Hawaii, therefore, this study used geology and soil type as the primary and secondary components of potential prediction. Although the radon potential of some Hawaiian soils suggests moderate risk, most houses are built above ground level and the radon soil potential is effectively decoupled from the house. Only underground facilities or those with closed or recirculating ventilation systems might have elevated radon potential. ?? 2005 Akade??miai Kiado??.

  19. Radon in houses and soil of Croatia

    Energy Technology Data Exchange (ETDEWEB)

    Radolic, V.; Vukovic, B.; Stanic, D.; Miklavcic, I.; Planinic, J. [Osijek Univ., Dept. of Physics (Croatia)

    2006-07-01

    Long-term indoor radon measurements in thousand Croatian homes, randomly selected, were performed by the LR-115 track etch detectors during a year 2003/2004. The obtained values of arithmetic means of radon concentrations in 20 Croatian counties were in range from 33 to 198 Bq/m{sup 3}, while the arithmetic and geometric means for Croatia were 68 and 50 Bq/m{sup 3}, respectively. Indoor radon concentrations follow log-normal distribution and the percentage of dwellings with concentrations above 400 Bq/m{sup 3} was 1.8 %. Radon concentrations in soil gas, at depth of 0.8 m, were measured by 'Alphaguard' measuring system. Association between levels of indoor and soil radon was investigated. (authors)

  20. A complete low cost radon detection system.

    Science.gov (United States)

    Bayrak, A; Barlas, E; Emirhan, E; Kutlu, Ç; Ozben, C S

    2013-08-01

    Monitoring the (222)Rn activity through the 1200 km long Northern Anatolian fault line, for the purpose of earthquake precursory, requires large number of cost effective radon detectors. We have designed, produced and successfully tested a low cost radon detection system (a radon monitor). In the detector circuit of this monitor, First Sensor PS100-7-CER-2 windowless PIN photodiode and a custom made transempedence/shaping amplifier were used. In order to collect the naturally ionized radon progeny to the surface of the PIN photodiode, a potential of 3500 V was applied between the conductive hemi-spherical shell and the PIN photodiode. In addition to the count rate of the radon progeny, absolute pressure, humidity and temperature were logged during the measurements. A GSM modem was integrated to the system for transferring the measurements from the remote locations to the data process center.

  1. Radon exposure and oropharyngeal cancer risk.

    Science.gov (United States)

    Salgado-Espinosa, Tania; Barros-Dios, Juan Miguel; Ruano-Ravina, Alberto

    2015-12-01

    Oropharyngeal cancer is a multifactorial disease. Alcohol and tobacco are the main risk factors. Radon is a human carcinogen linked to lung cancer risk, but its influence in other cancers is not well known. We aim to assess the effect of radon exposure on the risk of oral and pharyngeal cancer through a systematic review of the scientific literature. This review performs a qualitative analysis of the available studies. 13 cohort studies were included, most of them mortality studies, which analysed the relationship between occupational or residential radon exposure with oropharyngeal cancer mortality or incidence. Most of the included studies found no association between radon exposure and oral and pharyngeal cancer. This lack of effect was observed in miners studies and in general population studies. Further research is necessary to quantify if this association really exists and its magnitude, specially performing studies in general population, preferably living in areas with high radon levels.

  2. Novel method of measurement of radon exhalation from building materials.

    Science.gov (United States)

    Awhida, A; Ujić, P; Vukanac, I; Đurašević, M; Kandić, A; Čeliković, I; Lončar, B; Kolarž, P

    2016-11-01

    In the era of the energy saving policy (i.e. more air tight doors and windows), the radon exhaled from building materials tends to increase its concentration in indoor air, which increases the importance of the measurement of radon exhalation from building materials. This manuscript presents a novel method of the radon exhalation measurement using only a HPGe detector or any other gamma spectrometer. Comparing it with the already used methods of radon exhalation measurements, this method provides the measurement of the emanation coefficient, the radon diffusion length and the radon exhalation rate, all within the same measurement, which additionally defines material's radon protective properties. Furthermore it does not necessitate additional equipment for radon or radon exhalation measurement, which simplifies measurement technique, and thus potentially facilitates introduction of legal obligation for radon exhalation determination in building materials. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. A comparison of contemporary and retrospective radon gas measurements in high radon dwellings in Ireland

    Energy Technology Data Exchange (ETDEWEB)

    Kelleher, K.; McLaughlin, J.P. [University College Dublin (Ireland); Fenton, D.; Colgan, P.A. [Radiological Protection Institute of Ireland, Dublin (Ireland)

    2006-07-01

    Little correlations has been found between contemporary radon gas measurements made in the past and retrospective radon gas measurements in Irish dwellings. This would suggest that these two techniques would result in two significantly different cumulative radon exposure estimates. Contemporary radon gas measurements made a few years apart in the same room of a dwelling were found to be significantly different. None of these differences could be explained by known changes to the rooms themselves., such ventilation or structural alterations to the room. This highlights the limitations of the contemporary radon gas measurements as a surrogate measurement for use in residential radon epidemiology. The contemporary radon gas measurements made by the Radiological Protection Institute of Ireland (R.P.I.I.) and University College of Dublin (U.C.D.) do not cover the same exposure period as the retrospective estimates and so the accuracy of the retrospective measurements cannot be demonstrated. A weak correlation can be seen between the retrospective radon gas estimates and a combination of the two contemporary radon gas estimates. It is not unreasonable to expect improvement in the correlation if further contemporary radon gas measurements were made in these rooms. (N.C.)

  4. Experimental assessment of indoor radon and soil gas variability: the RADON project

    Science.gov (United States)

    Barbosa, S. M.; Pereira, A. J. S. C.; Neves, L. J. P. F.; Steinitz, G.; Zafrir, H.; Donner, R.; Woith, H.

    2012-04-01

    Radon is a radioactive noble gas naturally present in the environment, particularly in soils derived from rocks with high uranium content. Radon is formed by alpha decay from radium within solid mineral grains, but can migrate via diffusion and/or advection into the air space of soils, as well as into groundwater and the atmosphere. The exhalation of radon from the pore space of porous materials into the atmosphere of indoor environments is well known to cause adverse health effects due to the inhalation of radon's short-lived decay products. The danger to human health is particularly acute in the case of poorly ventilated dwellings located in geographical areas of high radon potential. The RADON project, funded by the Portuguese Science Foundation (FCT), aims to evaluate the temporal variability of radon in the soil and atmosphere and to examine the influence of meteorological effects in radon concentration. For that purpose an experimental monitoring station is being installed in an undisturbed dwelling located in a region of high radon potential near the old uranium mine of Urgeiriça (central Portugal). The rationale of the project, the set-up of the experimental radon monitoring station, and preliminary monitoring results will be presented.

  5. Discrete optimization

    CERN Document Server

    Parker, R Gary

    1988-01-01

    This book treats the fundamental issues and algorithmic strategies emerging as the core of the discipline of discrete optimization in a comprehensive and rigorous fashion. Following an introductory chapter on computational complexity, the basic algorithmic results for the two major models of polynomial algorithms are introduced--models using matroids and linear programming. Further chapters treat the major non-polynomial algorithms: branch-and-bound and cutting planes. The text concludes with a chapter on heuristic algorithms.Several appendixes are included which review the fundamental ideas o

  6. Radon in the soil air of Estonia.

    Science.gov (United States)

    Petersell, Valter; Täht-Kok, Krista; Karimov, Mark; Milvek, Heli; Nirgi, Siim; Raha, Margus; Saarik, Krista

    2017-01-01

    Several investigations in Estonia during 1996¬-1999 have shown that permissible level (200 Bq/m(3)) of radon (222Rn) in indoor air is exceeded in 33% of the inspected dwellings. This makes Estonia one of the five countries with highest radon risk in Europe (Fig 1). Due to correlation between the soil radon risk level and radon concentration in houses, small scale radon risk mapping of soil air was carried out (one study point per 70-100 km(2)). It turned out that one-third of Estonian mainland has high radon risk potential, where radon concentration in soil air exceeds safe limit of 50 kBq/m(3). In order to estimate radon content in soil air, two different methods developed in Sweden were used simultaneously. Besides measuring radon content from soil air at the depth of 80 cm with an emanometer (RnM), maximum potential content of radon in soil (RnG) was estimated based on the rate of eU (226Ra) concentration in soil, which was acquired by using gamma-ray spectrometer. Mapping and following studies revealed that simultaneously measured RnG and RnM in study points may often differ. To inspect the cause, several monitoring points were set up in places with different geological conditions. It appeared that unlike the RnG content, which remains close to average level in repeated measurements, the RnM content may differ more than three times periodically. After continuous observations it turned out that concentration of directly measured radon depended on various factors being mostly controlled by mineral composition of soil, properties of topsoil as well as different factors influencing aeration of soil. The results of Rn monitoring show that reliable level of radon risk in Estonian soils can only be acquired by using calculated Rn-concentration in soil air based on eU content and directly measured radon content of soil air in combination with interpreting specific geological and geochemical situations in the study points. Copyright © 2016 Elsevier Ltd. All rights

  7. High sensitivity radon emanation measurements.

    Science.gov (United States)

    Zuzel, G; Simgen, H

    2009-05-01

    The presented radon detection technique employs miniaturized ultra-low background proportional counters. (222)Rn samples are purified, mixed with a counting gas and filled into a counter using a special glass vacuum line. The absolute sensitivity of the system is estimated to be 40 microBq (20 (222)Rn atoms). For emanation investigations two metal sealed stainless steel vessels and several glass vials are available. Taking into account their blank contributions, measurements at a minimum detectable activity of about 100 microBq can be performed.

  8. Measurements of radon and chemical elements: Popocatepetl volcano; Mediciones de radon y elementos quimicos: Volcan Popocatepetl

    Energy Technology Data Exchange (ETDEWEB)

    Pena, P.; Segovia, N.; Lopez, B.; Reyes, A.V. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Armienta, M.A.; Valdes, C.; Mena, M. [IGFUNAM, Ciudad Universitaria, 04510 Mexico D.F. (Mexico); Seidel, J.L.; Monnin, M. [UMR 5569 CNRS Hydrosciences, Montpellier (France)

    2002-07-01

    The Popocatepetl volcano is a higher risk volcano located at 60 Km from Mexico City. Radon measurements on soil in two fixed seasons located in the north slope of volcano were carried out. Moreover the radon content, major chemical elements and tracks in water samples of three springs was studied. The radon of soil was determined with solid detectors of nuclear tracks (DSTN). The radon in subterranean water was evaluated through the liquid scintillation method and it was corroborated with an Alpha Guard equipment. The major chemical elements were determined with conventional chemical methods and the track elements were measured using an Icp-Ms equipment. The radon on soil levels were lower, indicating a moderate diffusion of the gas across the slope of the volcano. The radon in subterranean water shown few changes in relation with the active scene of the volcano. The major chemical elements and tracks showed a stable behavior during the sampling period. (Author)

  9. Radon, Smoking, and Lung Cancer: The Need to Refocus Radon Control Policy

    Science.gov (United States)

    Mendez, David; Philbert, Martin A.

    2013-01-01

    Exposure to radon is the second leading cause of lung cancer, and the risk is significantly higher for smokers than for nonsmokers. More than 85% of radon-induced lung cancer deaths are among smokers. The most powerful approach for reducing the public health burden of radon is shaped by 2 overarching principles: public communication efforts that promote residential radon testing and remediation will be the most cost effective if they are primarily directed at current and former smokers; and focusing on smoking prevention and cessation is the optimal strategy for reducing radon-induced lung cancer in terms of both public health gains and economic efficiency. Tobacco control policy is the most promising route to the public health goals of radon control policy. PMID:23327258

  10. Observations of surface radon in Central Italy

    Science.gov (United States)

    Carlo, Piero Di; Pitari, Giovanni; de Luca, Natalia; Battisti, Domenico

    2009-07-01

    Two years of in situ radon concentration measurements in the atmospheric surface layer have been collected in a central Italy town (L’Aquila), located in the Aterno river valley. These data have been analyzed in order to study the controlling mechanisms of surface radon abundance; observations of coincident meteorological parameters confirmed the role of dynamics on the local removal rate of this tracer. The relatively high negative correlation of hourly data of surface wind speed and radon activity concentration ( R = -0.54, on annual scale) suggests that dynamical removal of radon is one of the most important controlling processes of the tracer accumulation in the atmospheric surface layer. An attempt is made to quantify the precipitation impact on radon soil fluxes. No anticorrelation of radon and precipitation comes out from the data ( R = -0.15), as in previous studies. However, since the main physical parameter affecting the ground radon release is expected to be the soil accumulation of water, snow or ice, the emission flux has also been correlated with soil moisture; in this way a much clearer anticorrelation is found ( R = -0.54).

  11. A Rapid Method for Radon Determination

    Energy Technology Data Exchange (ETDEWEB)

    Enkhbat, N.; Shin, S. G.; Key, Y. U.; Cho, M. H. [POSTECH, Pohang (Korea, Republic of); Norov, N. [National University of Mongolia, Ulaanbaatar (Mongolia); Kim, G. [Kungpook National University, Daegu (Korea, Republic of); Namkung, W.; Lee, H. S. [Pohang Accelerator Laboratory, Pohang (Korea, Republic of)

    2015-05-15

    Research carried out in last decades has shown that more than 70% of a total annual radioactive dose received by people originates from natural sources of ionizing radiation, whereby 40% is due to inhalation and ingestion of natural radioactive gas radon {sup 222}Rn and its progeny. Radon has 3.5 days of half-life. However, its progeny is dangerous than Radon in the view of radiation protection. Radon measurement is commonly used in controlling radon concentration in underground mine, closed room and in forecasting earthquake. Radon gas emission rate in the immediate opening of the west ventilation shaft depends on the operation of the ventilation system, duration of ventilation system operation, and the air flow rate through the underground development. Specific activity of radon progeny in air (RaA (Po-218), RaB (Pb-214) and RaC (Bi-214)) and Ra-222 in radioactive equilibrium was calculated by formula 1 and 2, respectively. We include result of measurement carried out in the air around a mining. In Fig.2 shown that the distribution of Po-218, Pb-214, Bi-214 and Ra-222 isotopes releasing from west ventilation shaft in Gurvanbulag underground uranium mine in the eastern part of Mongolia.

  12. A study on the correlation between soil radon potential and average indoor radon potential in Canadian cities.

    Science.gov (United States)

    Chen, Jing; Ford, Ken L

    2017-01-01

    Exposure to indoor radon is identified as the main source of natural radiation exposure to the population. Since radon in homes originates mainly from soil gas radon, it is of public interest to study the correlation between radon in soil and radon indoors in different geographic locations. From 2007 to 2010, a total of 1070 sites were surveyed for soil gas radon and soil permeability. Among the sites surveyed, 430 sites were in 14 cities where indoor radon information is available from residential radon and thoron surveys conducted in recent years. It is observed that indoor radon potential (percentage of homes above 200 Bq m(-3); range from 1.5% to 42%) correlates reasonably well with soil radon potential (SRP: an index proportional to soil gas radon concentration and soil permeability; average SRP ranged from 8 to 26). In five cities where in-situ soil permeability was measured at more than 20 sites, a strong correlation (R(2) = 0.68 for linear regression and R(2) = 0.81 for non-linear regression) was observed between indoor radon potential and soil radon potential. This summary report shows that soil gas radon measurement is a practical and useful predictor of indoor radon potential in a geographic area, and may be useful for making decisions around prioritizing activities to manage population exposure and future land-use planning. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  13. Discrete transforms

    CERN Document Server

    Firth, Jean M

    1992-01-01

    The analysis of signals and systems using transform methods is a very important aspect of the examination of processes and problems in an increasingly wide range of applications. Whereas the initial impetus in the development of methods appropriate for handling discrete sets of data occurred mainly in an electrical engineering context (for example in the design of digital filters), the same techniques are in use in such disciplines as cardiology, optics, speech analysis and management, as well as in other branches of science and engineering. This text is aimed at a readership whose mathematical background includes some acquaintance with complex numbers, linear differen­ tial equations, matrix algebra, and series. Specifically, a familiarity with Fourier series (in trigonometric and exponential forms) is assumed, and an exposure to the concept of a continuous integral transform is desirable. Such a background can be expected, for example, on completion of the first year of a science or engineering degree cour...

  14. Soil radon levels across the Amer fault

    Energy Technology Data Exchange (ETDEWEB)

    Font, Ll. [Grup de Fisica de les Radiacions, Edifici Cc, Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain)], E-mail: lluis.font@uab.cat; Baixeras, C.; Moreno, V. [Grup de Fisica de les Radiacions, Edifici Cc, Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Bach, J. [Unitat de Geodinamica externa, Departament de Geologia, Edifici Cs, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain)

    2008-08-15

    Soil radon levels have been measured across the Amer fault, which is located near the volcanic region of La Garrotxa, Spain. Both passive (LR-115, time-integrating) and active (Clipperton II, time-resolved) detectors have been used in a survey in which 27 measurement points were selected in five lines perpendicular to the Amer fault in the village area of Amer. The averaged results show an influence of the distance to the fault on the mean soil radon values. The dynamic results show a very clear seasonal effect on the soil radon levels. The results obtained support the hypothesis that the fault is still active.

  15. Risks related to exposure to radon

    Directory of Open Access Journals (Sweden)

    Juan Miguel Barros Dios

    2010-12-01

    Full Text Available They discuss the different scientific evidence that radon and its short half-life descendants are responsible for the appearance of a considerable number of lung cancers among the exposed population in homes and public buildings (occupational exposure. It also draws a small glimpse at the road traveled by this knowledge and acceptance difficult administrations in many countries and, in particular, of Spain, as well as the various investigations that the team do Galego Radon and Radon Laboratory from Galicia, the area of Public Health, University of Santiago de Compostela (USC, are contributing to scientific knowledge. Finally, they appreciate the few legislative initiatives on the problem in Spain.

  16. Indoor radon concentration forecasting in South Tyrol.

    Science.gov (United States)

    Verdi, L; Weber, A; Stoppa, G

    2004-01-01

    In this paper a modern statistical technique of multivariate analysis is applied to an indoor radon concentration data base. Several parameters are more or less significant in determining the radon concentration inside a building. The elaboration of the information available on South Tyrol makes it possible both to identify the statistically significant variables and to build up a statistical model that allows us to forecast the radon concentration in dwellings, when the values of the same variables involved are given. The results confirm the complexity of the phenomenon.

  17. Radon screening for XENON1T

    Energy Technology Data Exchange (ETDEWEB)

    Lindemann, Sebastian [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    2015-07-01

    Radon with its isotope {sup 222}Rn is one of the dominant sources of internal background in liquid xenon detectors searching for low energetic rare events like WIMP-nucleon scattering. In my talk I briefly review the problem posed by {sup 222}Rn and motivate the screening strategy followed by XENON1T. I introduce the radon emanation technique making use of ultra low background proportional counters and present selected results obtained during the design and construction phases of XENON1T. Finally, I sketch advances in radon emanation assay techniques and give a short outlook on upcoming measurements.

  18. Radon - kilder og måling

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn; Wraber, Ida Kristina

    Når man skal vurdere en bygnings indeklima er det vigtigt at have viden om radonindholdet. Denne viden får man ved måling, da radon hverken kan ses, lugtes, høres, smages eller føles. Denne anvisning redegør for radons oprindelse og indvirkning på menneskers sundhed. Anvisningen beskriver metoder...... til måling og analyse af radonindholdet i en bygnings indeluft. Læseren får indsigt i, hvordan man relativt let med standardiserede metoder kan eftervise, om en bygning opfylder bygningsreglementets krav til radon i indeluften. Anvisningen henvender sig til bygningsejere, bygherrer, projekterende og...

  19. Coprecipitation of radon oxide with cesium fluoroxenate

    Energy Technology Data Exchange (ETDEWEB)

    Avrorin, V.V.; Krasikova, R.N.; Nefedov, V.D.; Toropova, M.A.

    1986-03-01

    This paper presents a study of the processes of coprecipitation of radon oxide with cesium fluoroxenate in aqueous solutions. It has been shown that the reason for the coprecipitation in the case at hand is the occurrence of a process of isomorphous cocrystallization. The results obtained are examined as a confirmation of the suggestion that the hydrolysis product of the radon fluoride which is formed on thermal initiation of reaction in the rn-F2-BrF5-NaF system is radon trioxide, Rno3.

  20. Hierarchical Network Design

    DEFF Research Database (Denmark)

    Thomadsen, Tommy

    2005-01-01

    of different types of hierarchical networks. This is supplemented by a review of ring network design problems and a presentation of a model allowing for modeling most hierarchical networks. We use methods based on linear programming to design the hierarchical networks. Thus, a brief introduction to the various....... The thesis investigates models for hierarchical network design and methods used to design such networks. In addition, ring network design is considered, since ring networks commonly appear in the design of hierarchical networks. The thesis introduces hierarchical networks, including a classification scheme...... linear programming based methods is included. The thesis is thus suitable as a foundation for study of design of hierarchical networks. The major contribution of the thesis consists of seven papers which are included in the appendix. The papers address hierarchical network design and/or ring network...

  1. Radiological risk assessment of environmental radon

    Science.gov (United States)

    Khalid, Norafatin; Majid, Amran Ab; Yahaya, Redzuwan; Yasir, Muhammad Samudi

    2013-11-01

    Measurements of radon gas (222Rn) in the environmental are important to assess indoor air quality and to study the potential risk to human health. Generally known that exposure to radon is considered the second leading cause of lung cancer after smoking. The environmental radon concentration depends on the 226Ra concentration, indoor atmosphere, cracking on rocks and building materials. This study was carried out to determine the indoor radon concentration from selected samples of tin tailings (amang) and building materials in an airtight sealed homemade radon chamber. The radiological risk assessment for radon gas was also calculated based on the annual exposure dose, effective dose equivalent, radon exhalation rates and fatal cancer risk. The continuous radon monitor Sun Nuclear model 1029 was used to measure the radon concentration emanates from selected samples for 96 hours. Five types of tin tailings collected from Kampar, Perak and four samples of building materials commonly used in Malaysia dwellings or building constructions were analysed for radon concentration. The indoor radon concentration determined in ilmenite, monazite, struverite, xenotime and zircon samples varies from 219.6 ± 76.8 Bq m-3 to 571.1 ± 251.4 Bq m-3, 101.0 ± 41.0 Bq m-3 to 245.3 ± 100.2 Bq m-3, 53.1 ± 7.5 Bq m-3 to 181.8 ± 9.7 Bq m-3, 256.1 ± 59.3 Bq m-3 to 652.2 ± 222.2 Bq m-3 and 164.5 ± 75.9 Bq m-3 to 653.3 ± 240.0 Bq m-3, respectively. Whereas, in the building materials, the radon concentration from cement brick, red-clay brick, gravel aggregate and cement showed 396.3 ± 194.3 Bq m-3, 192.1 ± 75.4 Bq m-3, 176.1 ± 85.9 Bq m-3 and 28.4 ± 5.7 Bq m-3, respectively. The radon concentration in tin tailings and building materials were found to be much higher in xenotime and cement brick samples than others. All samples in tin tailings were exceeded the action level for radon gas of 148 Bq m-3 proposed by EPA except monazite 0.15 kg, struverite 0.15 kg and 0.25 kg. Whereas

  2. Hierarchical Multiagent Reinforcement Learning

    Science.gov (United States)

    2004-01-25

    In this paper, we investigate the use of hierarchical reinforcement learning (HRL) to speed up the acquisition of cooperative multiagent tasks. We...introduce a hierarchical multiagent reinforcement learning (RL) framework and propose a hierarchical multiagent RL algorithm called Cooperative HRL. In

  3. DETERMINATION OF RADIUM AND RADON CONCENTRATIONS IN SOME ROCK SAMPLES

    OpenAIRE

    BAYKARA, Oktay

    2006-01-01

    The concentrations of radium (226Ra), radon (222Rn) and radon exhalation rate in nine rock samples have been determined using solid-state nuclear track detectors (CR-39). The measured maximum values of radium, radon and radon exhalation rate in rock samples were found to be 24.62 Bq/kg, 4911.32 Bq/m3 and 4,86 Bqm-2h-1, respectively. Linear correlation was observed among radon concentration, radon exhalation and radium concentration. The linear correlation coefficient between radium content an...

  4. Thorough investigations on indoor radon in Baita radon-prone area (Romania)

    Energy Technology Data Exchange (ETDEWEB)

    Cucos, Alexandra; Cosma, Constantin [Faculty of Environmental Science and Engineering, ' Babes-Bolyai' University, Fantanele No. 30, 400294, Cluj-Napoca (Romania); Dicu, Tiberius, E-mail: tiberius.dicu@ubbcluj.ro [Faculty of Environmental Science and Engineering, ' Babes-Bolyai' University, Fantanele No. 30, 400294, Cluj-Napoca (Romania); Begy, Robert; Moldovan, Mircea; Papp, Botond; Nita, Dan; Burghele, Bety [Faculty of Environmental Science and Engineering, ' Babes-Bolyai' University, Fantanele No. 30, 400294, Cluj-Napoca (Romania); Sainz, Carlos [Faculty of Environmental Science and Engineering, ' Babes-Bolyai' University, Fantanele No. 30, 400294, Cluj-Napoca (Romania); Department of Medical Physics, Faculty of Medicine, University of Cantabria, c/Herrera Oria s/n., 39011, Santander (Spain)

    2012-08-01

    A comprehensive radon survey has been carried out in Baita radon-prone area, Transylvania, Romania, in 4 localities (Baita, Nucet, Finate, and Cimpani) situated in the vicinity of former Romanian uranium mines. Indoor radon concentrations have been measured in 1128 ground floor rooms and cellars of 303 family houses by using CR-39 diffusion type radon detectors. The annual average of indoor radon concentration for Baita area was found to be 241 {+-} 178 Bq m{sup -3}, which is about two times higher than the average value of 126 Bq m{sup -3}, computed for Romania. About 28% of investigated houses exceed the reference level of radon gas in dwellings of 300 Bq m{sup -3}. The indoor radon measurements on each house have been carried out in several rooms simultaneously with the aim of obtaining a more detailed picture on the exposure to radon in the studied area. An analysis on the variability of radon levels among floors (floor-to-floor variation) and rooms (room-to-room variation) and also the influence of factors like the presence of cellar or the age of the building is presented. The coefficient of variation (CV) within ground floor rooms of the same house (room-to-room variation) ranged between 0.9 and 120.8%, with an arithmetic mean of 46.2%, a large variability among rooms within surveyed dwellings being clearly identified. The mean radon concentration in bedrooms without cellar was higher than in bedrooms above the cellar, the difference being statistically significant (t test, one tail, p < 0.001, n = 82). For houses built during 1960-1970 an increasing trend for radon levels was observed, but overall there was no significant difference in indoor radon concentrations by age of dwelling (one-way ANOVA test, p > 0.05). - Highlights: Black-Right-Pointing-Pointer The annual average of indoor radon concentration for Baita area was 241 {+-} 178 Bq m{sup -3}. Black-Right-Pointing-Pointer A large variability among rooms within surveyed dwellings was clearly evidenced

  5. Comparison of retrospective and contemporary indoor radon measurements in a high-radon area of Serbia

    Energy Technology Data Exchange (ETDEWEB)

    Zunic, Z.S. [Institute of Nuclear Sciences ' Vinca' , Belgrade (Serbia); Yarmoshenko, I.V. [Institute of Industrial Ecology, Ural Branch of Russian Academy of Sciences, Ekaterinburg (Russian Federation)], E-mail: ivy@ecko.uran.ru; Kelleher, K. [Radiological Protection Institute of Ireland, Dublin (Ireland); Paridaens, J. [SCK.CEN Mol (Belgium); Mc Laughlin, J.P. [School of Physics, University College Dublin (Ireland); Celikovic, I.; Ujic, P. [Institute of Nuclear Sciences ' Vinca' , Belgrade (Serbia); Onischenko, A.D. [Institute of Industrial Ecology, Ural Branch of Russian Academy of Sciences, Ekaterinburg (Russian Federation); Jovanovic, S.; Demajo, A. [Institute of Nuclear Sciences ' Vinca' , Belgrade (Serbia); Birovljev, A. [Radonlab Ltd., Oslo (Norway); Bochicchio, F. [Italian National Institute of Health, Rome (Italy)

    2007-11-15

    In Niska Banja, Serbia, which is a high-radon area, a comparison was made between two retrospective radon measuring methods and contemporary radon measurements. The two retrospective methods derive the radon concentrations that occurred in dwellings over longer periods in the past, based on the amount of trapped {sup 210}Po on the surface of glass objects (surface traps, ST) or in the bulk of porous materials (volume traps, VT). Both surface implanted {sup 210}Po in glass objects and contemporary radon in air were measured in 46 rooms, distributed in 32 houses of this radon spa-town, using a dual alpha track detector configuration (CR-39 and LR115) and CR-39 track etched detectors, respectively. In addition to the use of surface trap measurements, in 18 rooms (distributed in 15 houses) VT samples of suitable material were also collected, allowing to compare ST and VT retrospective radon concentration estimates. For each room, contemporary annual radon concentrations (CONT) were measured or estimated using seasonal correction factors. The distribution of the radon concentration in all data sets was found to be close to lognormal (Chi-square test > 0.05). Geometric means (GM) are similar, ranging from 1040 to 1380 Bq m{sup -3}, whereas geometric standard deviations (GSD) for both the retrospective methods are greater than for the CONT method, showing reasonable agreement between VT, ST and CONT measurements. A regression analysis, with respect to the lognormal distribution of each data set, shows that for VT-ST the correlation coefficient r is 0.85, for VT-CONT r is 0.82 and for ST-CONT r is 0.73. Comparison of retrospective and contemporary radon concentrations with regard to supposed long-term indoor radon changes further supports the principal agreement between the retrospective and conventional methods.

  6. Comparison of retrospective and contemporary indoor radon measurements in a high-radon area of Serbia.

    Science.gov (United States)

    Zunić, Z S; Yarmoshenko, I V; Kelleher, K; Paridaens, J; Mc Laughlin, J P; Celiković, I; Ujić, P; Onischenko, A D; Jovanović, S; Demajo, A; Birovljev, A; Bochicchio, F

    2007-11-15

    In Niska Banja, Serbia, which is a high-radon area, a comparison was made between two retrospective radon measuring methods and contemporary radon measurements. The two retrospective methods derive the radon concentrations that occurred in dwellings over longer periods in the past, based on the amount of trapped (210)Po on the surface of glass objects (surface traps, ST) or in the bulk of porous materials (volume traps, VT). Both surface implanted (210)Po in glass objects and contemporary radon in air were measured in 46 rooms, distributed in 32 houses of this radon spa-town, using a dual alpha track detector configuration (CR-39 and LR115) and CR-39 track etched detectors, respectively. In addition to the use of surface trap measurements, in 18 rooms (distributed in 15 houses) VT samples of suitable material were also collected, allowing to compare ST and VT retrospective radon concentration estimates. For each room, contemporary annual radon concentrations (CONT) were measured or estimated using seasonal correction factors. The distribution of the radon concentration in all data sets was found to be close to lognormal (Chi-square test>0.05). Geometric means (GM) are similar, ranging from 1040 to 1380 Bq m(-3), whereas geometric standard deviations (GSD) for both the retrospective methods are greater than for the CONT method, showing reasonable agreement between VT, ST and CONT measurements. A regression analysis, with respect to the lognormal distribution of each data set, shows that for VT-ST the correlation coefficient r is 0.85, for VT-CONT r is 0.82 and for ST-CONT r is 0.73. Comparison of retrospective and contemporary radon concentrations with regard to supposed long-term indoor radon changes further supports the principal agreement between the retrospective and conventional methods.

  7. Thorough investigations on indoor radon in Băiţa radon-prone area (Romania).

    Science.gov (United States)

    Cucoş Dinu, Alexandra; Cosma, Constantin; Dicu, Tiberius; Begy, Robert; Moldovan, Mircea; Papp, Botond; Niţă, Dan; Burghele, Bety; Sainz, Carlos

    2012-08-01

    A comprehensive radon survey has been carried out in Băiţa radon-prone area, Transylvania, Romania, in 4 localities (Băiţa, Nucet, Fînaţe, and Cîmpani) situated in the vicinity of former Romanian uranium mines. Indoor radon concentrations have been measured in 1128 ground floor rooms and cellars of 303 family houses by using CR-39 diffusion type radon detectors. The annual average of indoor radon concentration for Băiţa area was found to be 241±178 Bq m(-3), which is about two times higher than the average value of 126 Bq m(-3), computed for Romania. About 28% of investigated houses exceed the reference level of radon gas in dwellings of 300 Bq m(-3). The indoor radon measurements on each house have been carried out in several rooms simultaneously with the aim of obtaining a more detailed picture on the exposure to radon in the studied area. An analysis on the variability of radon levels among floors (floor-to-floor variation) and rooms (room-to-room variation) and also the influence of factors like the presence of cellar or the age of the building is presented. The coefficient of variation (CV) within ground floor rooms of the same house (room-to-room variation) ranged between 0.9 and 120.8%, with an arithmetic mean of 46.2%, a large variability among rooms within surveyed dwellings being clearly identified. The mean radon concentration in bedrooms without cellar was higher than in bedrooms above the cellar, the difference being statistically significant (t test, one tail, pradon levels was observed, but overall there was no significant difference in indoor radon concentrations by age of dwelling (one-way ANOVA test, p>0.05).

  8. Radon measurements in some areas in Bangladesh

    Energy Technology Data Exchange (ETDEWEB)

    Hamid Khan, M.A. [Physics Division, Atomic Energy Centre, Bangladesh Atomic Energy Commission, P.O. Box 164, Dhaka-1000 (Bangladesh)], E-mail: hamidkhan1950@yahoo.com; Chowdhury, M.S. [Physics Department, Dhaka University, Dhaka-1000 (Bangladesh)

    2008-08-15

    A survey of radon level measurements using CR-39 has been carried out in some of urban and rural residential areas and one gas explosion area in Bangladesh. The lowest level of radon concentration was found to be 49Bqm{sup -3} inside a hospital in Cox's Bazar district and the highest level was found to be 835Bqm{sup -3} inside a mud-made old residential house in Sylhet city. It was observed that old residential houses were found to have higher levels of radon concentrations compared to newly built houses. The radon level at the gas explosion area at Magurchara in Moulvibazar district was found to be 408{+-}98Bqm{sup -3}.

  9. GEOMETRICALLY INVARIANT WATERMARKING BASED ON RADON TRANSFORMATION

    Institute of Scientific and Technical Information of China (English)

    Cai Lian; Du Sidan; Gao Duntang

    2005-01-01

    The weakness of classical watermarking methods is the vulnerability to geometrical distortions that widely occur during normal use of the media. In this letter, a new imagewatermarking method is presented to resist Rotation, Scale and Translation (RST) attacks. The watermark is embedded into a domain obtained by taking Radon transform of a circular area selected from the original image, and then extracting Two-Dimensional (2-D) Fourier magnitude of the Radon transformed image. Furthermore, to prevent the watermarked image from degrading due to inverse Radon transform, watermark signal is inversely Radon transformed individually.Experimental results demonstrate that the proposed scheme is able to withstand a variety of attacks including common geometric attacks.

  10. Dependency of radon entry on pressure difference

    Science.gov (United States)

    Kokotti, H.; Kalliokoski, P.; Jantunen, M.

    Radon levels, ventilation rate and pressure differences were monitored continuously in four apartment houses with different ventilation systems. Two of them were ventilated by mechanical exhaust, one by mechanical supply and exhaust, and one by natural ventilation. The two-storey houses were constructed from concrete elements on a slab and located on a gravel esker. It was surprising to find that increasing the ventilation rate increased levels of radon in the apartments. Increased ventilation caused increased outdoor-indoor pressure difference, which in turn increased the entry rate of radon and counteracted the diluting effect of ventilation. The increase was significant when the outdoor-indoor pressure difference exceeded 5 Pa. Especially in the houses with mechanical exhaust ventilation the pressure difference was the most important factor of radon entry rate, and contributed up to several hundred Bq m -3 h -1.

  11. Radon measurement using a liquid scintillation spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Koga, Taeko; Morishima, Hiroshige; Kawai, Hiroshi; Kondo, Sohei (Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.); Mifune, Masaki; Konishi, Masanobu; Shirai, Chiaki

    1992-12-01

    A convenient radon detecting device for the purpose of estimating natural radiation exposure is described. The [alpha] radioactivity of radon gas absorbed in fine active carbon particles exposed to air is measured with a liquid scintillation spectrometer (Packard-PICO-RAD system). Its detection limits are 2mBq/l in air and 0.5 Bq/l in water with an accuracy of about 10 %. Radon concentrations at Misasa hot springs in Tottori prefecture were measured using this method. They were 0.16 [approx] 7.7 Bq/l in a bath room and 0.057 [approx] 0.36 Bq/l outdoors. Radon concentrations of the hot springs were 82 [approx] 1,700 Bq/l. (author).

  12. Radon Transform and Light-Cone Distributions

    Science.gov (United States)

    Teryaev, O. V.

    2016-08-01

    The relevance of Radon transform for generalized and transverse momentum dependent parton distributions is discussed. The new application for conditional (fracture) parton distributions and dihadron fragmentation functions is suggested.

  13. Radon in private drinking water wells.

    Science.gov (United States)

    Otahal, P; Merta, J; Burian, I

    2014-07-01

    At least 10% of inhabitants in the Czech Republic are supplied with water from private sources (private wells, boreholes). With the increasing cost of water, the number of people using their own sources of drinking water will be likely to increase. According to the Decree of the State Office for Nuclear Safety about the Radiation Protection 307/2002 as amended by Decree 499/2005, the guideline limit for the supplied drinking water ('drinking water for public supply') for radon concentration is 50 Bq·l(-1). This guideline does not apply to private sources of drinking water. Radon in water influences human health by ingestion and also by inhalation when radon is released from water during showering and cooking. This paper presents results of measurements of radon concentrations in water from private wells in more than 300 cases. The gross concentration of alpha-emitting radionuclides and the concentrations of radium and uranium were also determined.

  14. El gas radon y la hormesis

    National Research Council Canada - National Science Library

    Garzon Valencia, Gustavo

    2006-01-01

    ..., el cual sale desde el interior de la Tierra. Una construccion con poca ventilacion puede servir de lugar de acumulacion del gas radon y por lo tanto puede aumentar las dosis efectivas de radiactividad sobre el organismo de sus residentes...

  15. Radon Exhalation Considered in Building Material Standard

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>In order to investigate the relationship between radon exhalation and specific activity of natural nuclides in building material, here different kinds of samples of building materials were measured by the

  16. Novel Radon Sub-Slab Suctioning System

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2013-01-01

    the zone below the ground-floor construction. For this purpose a new system of prefabricated lightweight elements is introduced. The effectiveness of the system is demonstrated for the case of a ground-floor reinforced concrete slab situated on top of a rigid insulation layer (consisting of a thermal......A new principle for radon protection is currently presented which makes use of a system of horizontal pressurised air ducts located within the lower part of the rigid insulation layer of the ground-floor slab. The function of this system is based on the principles of pressure reduction within...... a grid of horizontal air ducts with low pressure which are able to remove air and radon from the ground. Results showed the system to be effective in preventing radon infiltrating from the ground through the ground-floor slab, avoiding high concentrations of radon being accumulated inside houses...

  17. Distribution of indoor radon levels in Mexico

    CERN Document Server

    Espinosa, G; Rickards, J; Gammage, R B

    1999-01-01

    Our laboratory has carried out a systematic monitoring and evaluation of indoor radon concentration levels in Mexico for ten years. The results of the distribution of indoor radon levels for practically the entire country are presented, together with information on geological characteristics, population density, socioeconomic levels of the population, and architectural styles of housing. The measurements of the radon levels were made using the passive method of nuclear tracks in solids with the end-cup system. CR-39 was used as the detector material in combination with a one-step chemical etching procedure and an automatic digital- image counting system. Wherever a high level was measured, a confirming measurement was made using a dynamic method. The results are important for future health studies, including the eventual establishment of patterns for indoor radon concentration, as it has been done in the USA and Europe.

  18. RADON AND CARCINOGENIC RISK IN MOSCOW

    Directory of Open Access Journals (Sweden)

    S. M. Golovanev

    2015-01-01

    Full Text Available Objective: comparative evaluation of carcinogenic risk inMoscowfrom radon in indoor and atmospheric pollutants.Materials and methods: the lung cancer incidence in Moscow; radiation-hygienic passport of the territory; .U.S. EPA estimated average age at all and radon induced deaths, years of life lost; Report of UNSCEAR 2006 and WHO handbook on indoor radon, 2009. Trend analysis of incidence; evaluation of the excess relative risk; assessment of ratio radon-induced population risk and published values оf total population carcinogenic risk from chemical carcinogens.Results: it is shown that the 304 cases of lung cancer per year (1. 85 10-3 on average from 2006 to 2011 (21280diseases for 70 years in addition to background level induced by radon; the differences in average trends of all lungcancer incidence in the districts can exceed 25%.Conclusion. The potential of risk reduction by measures of mitigation radon concentration exceeds 5 times the cost efficiency to reduce emissions from vehicles and can reduce cancer incidence, on average 236 cases per year; population risk 16520 cases over 70 years or save not less than 2832 person-years of life per year. The annual effect of reducing losses from not-survival of 12 years as a result of radon-induced lung cancer deaths exceeds 14160000 dollars. The evaluating of the carcinogenic risk from radon in accordance with the definition of population risk increases the predictive evaluation of the effectiveness of preventive measures more than twice.

  19. Personal radon dosimetry from eyeglass lenses.

    Science.gov (United States)

    Fleischer, R L; Meyer, N R; Hadley, S A; MacDonald, J; Cavallo, A

    2001-01-01

    Eyeglass lenses are commonly composed of allyl-diglycol carbonate (CR-39), an alpha-particle detecting plastic, thus making such lenses personal radon dosemeters. Samples of such lenses have been obtained, etched to reveal that radon and radon progeny alpha tracks can be seen in abundance, and sensitivities have been calibrated in radon chambers as a primary calibration, and with a uranium-based source of alpha particles as a convenient secondary standard. With one exception natural, environmental (fossil) track densities ranged from less than 3,000 to nearly 70,000 per cm2 for eyeglasses that had been worn for various times from one to nearly five years. Average radon concentrations to which those wearers were exposed are inferred to be in the range 14 to 130 Bq x m(-3) (0.4 to 3.5 pCi x l(-1)). A protocol for consistent, meaningful readout is derived and used. In the exceptional case the fossil track density was 1,780,000 cm(-2) and the inferred (24 h) average radon concentration was 6500 Bq x m(-3) (175 pCi x l(-1)) for a worker at an inactive uranium mine that is used for therapy.

  20. Radon emanation from radium specific adsorbents.

    Science.gov (United States)

    Alabdula'aly, Abdulrahman I; Maghrawy, Hamed B

    2010-01-01

    Pilot studies were undertaken to quantify the total activity of radon that is eluted following no-flow periods from several Ra-226 adsorbents loaded to near exhaustion. The adsorbents studied included two types of barium sulphate impregnated alumina (ABA-8000 and F-1) and Dowex MSC-1 resin treated by either barium hydroxide or barium chloride. In parallel, radium loaded plain activated aluminas and Dowex MSC-1 resin were similarly investigated. The results revealed that radon was quantitatively eluted during the first few bed volumes of column operation after no-flow periods. Although similar radon elution profiles were obtained, the position of the radon peak was found to vary and depended on the adsorbent type. Radon levels up to 24 and 14 kBq dm(-3) were measured after a rest period of 72h from radium exhausted Dowex MSC-1 treated with barium chloride and F-1 impregnated alumina with barium sulphate, respectively. The eluted radon values measured experimentally were compared to those calculated theoretically from accumulated radium quantities for the different media. For plain adsorbents, an agreement better than 10% was obtained. For treated resin-types a consistency within 30% but for impregnated alumina-types high discrepancy between respective values were obtained.

  1. The radon gas. An air pollutant

    Directory of Open Access Journals (Sweden)

    Luis Santiago Quindós Poncela

    2010-12-01

    Full Text Available In this work different aspects about the problem of the radon in dwellings are approached. This gas of natural origin is virtually present in all the soils in the earth’s crust due to the presence of uranium and radium in the composition of them. Depending on architectural factors and of occupancy habits of the house, high concentrations of this gas can be reached indoors. In these situations, there is a quantifiable increment of the risk of developing lung cancer in the inhabitants of the housing. In the last years the methodological improvements in the realization of epidemiologic studies have led to the obtaining of scientific evidences about the relationship between the presence of indoor radon and the risk of lung cancer. This relationship, found years ago in workers of uranium mines, has been corroborated in the case of the residential radon by the light of several recent meta-analysis performed on groups of epidemiologic studies. More than 6.000 radon measurements have been carried out in Spain during the last 25 years. A summary of the results obtained from the main national radon surveys are also presented, as well as the criteria recently established by the Spanish Nuclear Safety Council concerning radon action levels in dwellings and workplaces.

  2. Hierarchical Network Design

    DEFF Research Database (Denmark)

    Thomadsen, Tommy

    2005-01-01

    Communication networks are immensely important today, since both companies and individuals use numerous services that rely on them. This thesis considers the design of hierarchical (communication) networks. Hierarchical networks consist of layers of networks and are well-suited for coping...... the clusters. The design of hierarchical networks involves clustering of nodes, hub selection, and network design, i.e. selection of links and routing of ows. Hierarchical networks have been in use for decades, but integrated design of these networks has only been considered for very special types of networks....... The thesis investigates models for hierarchical network design and methods used to design such networks. In addition, ring network design is considered, since ring networks commonly appear in the design of hierarchical networks. The thesis introduces hierarchical networks, including a classification scheme...

  3. RADON REDUCTION AND RADON-RESISTANT CONSTRUCTION DEMONSTRATIONS IN NEW YORK - VOLUME 2: APPENDICES

    Science.gov (United States)

    Growing concern about health risks associated with exposure to indoor radon, a radioactive gas found in varying amounts in nearly all houses, has underscored the need for dependable radon reduction methods in existing and newly constructed houses. Responding to this need, the U....

  4. Radon and radon-daughter concentrations in air in the vicinity of the Anaconda Uranium Mill

    Energy Technology Data Exchange (ETDEWEB)

    Momeni, M H; Lindstrom, J B; Dungey, C E; Kisieleski, W E

    1979-11-01

    Radon concentration, working level, and meteorological variables were measured continuously from June 1977 through June 1978 at three stations in the vicinity of the Anaconda Uranium Mill with measurements integrated to hourly intervals. Both radon and daughters show strong variations associated with low wind velocities and stable atmospheric conditions, and diurnal variations associated with thermal inversions. Average radon concentration shows seasonal dependence with highest concentrations observed during fall and winter. Comparison of radon concentrations and working levels between three stations shows strong dependence on wind direction and velocity. Radon concentrations and working-level distributions for each month and each station were analyzed. The average maximum, minimum, and modal concentration and working levels were estimated with observed frequencies. The highest concentration is 11,000 pCi/m/sup 3/ on the tailings. Working-level variations parallel radon variations but lag by less than one hour. The highest working levels were observed at night when conditions of higher secular radioactive equilibrium for radon daughters exist. Background radon concentration was measured at two stations, each located about 25 km from the mill, and the average is 408 pCi/m/sup 3/. Average working-level background is 3.6 x 10/sup -3/.

  5. Determination of air-loop volume and radon partition coefficient for measuring radon in water sample.

    Science.gov (United States)

    Lee, Kil Yong; Burnett, William C

    A simple method for the direct determination of the air-loop volume in a RAD7 system as well as the radon partition coefficient was developed allowing for an accurate measurement of the radon activity in any type of water. The air-loop volume may be measured directly using an external radon source and an empty bottle with a precisely measured volume. The partition coefficient and activity of radon in the water sample may then be determined via the RAD7 using the determined air-loop volume. Activity ratios instead of absolute activities were used to measure the air-loop volume and the radon partition coefficient. In order to verify this approach, we measured the radon partition coefficient in deionized water in the temperature range of 10-30 °C and compared the values to those calculated from the well-known Weigel equation. The results were within 5 % variance throughout the temperature range. We also applied the approach for measurement of the radon partition coefficient in synthetic saline water (0-75 ppt salinity) as well as tap water. The radon activity of the tap water sample was determined by this method as well as the standard RAD-H2O and BigBottle RAD-H2O. The results have shown good agreement between this method and the standard methods.

  6. Application of a radon model to explain indoor radon levels in a Swedish house

    CERN Document Server

    Font, L; Jönsson, G; Enge, W; Ghose, R

    1999-01-01

    Radon entry from soil into indoor air and its accumulation indoors depends on several parameters, the values of which normally depend on the specific characteristics of the site. The effect of a specific parameter is often difficult to explain from the result of indoor radon measurements only. The adaptation of the RAGENA (RAdon Generation, ENtry and Accumulation indoors) model to a Swedish house to characterise indoor radon levels and the relative importance of the different radon sources and entry mechanisms is presented. The building is a single-zone house with a naturally-ventilated crawl space in one part and a concrete floor in another part, leading to different radon levels in the two parts of the building. The soil under the house is moraine, which is relatively permeable to radon gas. The house is naturally-ventilated. The mean indoor radon concentration values measured with nuclear track detectors in the crawl-space and concrete parts of the house are respectively 75+-30 and 200+-80 Bq m sup - sup 3...

  7. RADON REDUCTION AND RADON-RESISTANT CONSTRUCTION DEMONSTRATIONS IN NEW YORK - VOLUME 2: APPENDICES

    Science.gov (United States)

    Growing concern about health risks associated with exposure to indoor radon, a radioactive gas found in varying amounts in nearly all houses, has underscored the need for dependable radon reduction methods in existing and newly constructed houses. Responding to this need, the U....

  8. Remote online monitoring of radon wells used for therapy in bathtubs

    Science.gov (United States)

    von Philipsborn, Henning

    2017-04-01

    Sibyllenbad, in the community of Neualbenreuth, 140 km NNE of Regensburg, is well known for two radon wells and one containing carbon dioxide. The water is used pure or mixed for therapy in 200 L bathtubs for a number of indications. Since its beginning, 26 years ago, the author is active in measuring radon and radon decay products and their factor of equilibrium in air and in water for radiation protection of the personnel and for radon water quality assurance for the patients. For the special local operating conditions - high time resolution of measurements is asked - novel measuring methods and instruments were developed. These proved to be useful for several other applications, not foreseen at the beginning. Recently, a probe was installed for online monitoring of water entering the main water storage tank of 42 m3, at the Kurhaus, two km from the radon wells. The probe consists of a 51 mm x 76 mm NaI (Tl) scintillator with photomultiplier, immersed in continuously flowing water in an 8 L pot. The MCA registers the pulses between 200 and 650 keV of the Rn decay products Pb-214 and Bi-214. Specially developed software calculates the gross [cps] from the total counts for variable counting times. The background, determined separately, is subtracted and the net is multiplied with a calibration factor [Bq/L per net cps], determined separately. The activity concentration [Bq/L] of the radon decay products in water is plotted vs. real time (plot P). With Teamviewer, remote online monitoring is possible from the Radiometric Seminar. At the Rn wells, the flow rate [L/s] of the discontinuously working pumps and the lowering of the water level in [m] is measured online. The two quantities are directly correlated, and with a time lag to the demand of radon water from the Kurhaus. Several series of discrete measurements of water, both at the well and at the storage tank, fresh and after 1, 2 and 3 h after storage in full, closed bottles, reveal factors of equilibrium k

  9. Analysis of discrete-to-discrete imaging models for iterative tomographic image reconstruction and compressive sensing

    CERN Document Server

    Jørgensen, Jakob H; Pan, Xiaochuan

    2011-01-01

    Discrete-to-discrete imaging models for computed tomography (CT) are becoming increasingly ubiquitous as the interest in iterative image reconstruction algorithms has heightened. Despite this trend, all the intuition for algorithm and system design derives from analysis of continuous-to-continuous models such as the X-ray and Radon transform. While the similarity between these models justifies some crossover, questions such as what are sufficient sampling conditions can be quite different for the two models. This sampling issue is addressed extensively in the first half of the article using singular value decomposition analysis for determining sufficient number of views and detector bins. The question of full sampling for CT is particularly relevant to current attempts to adapt compressive sensing (CS) motivated methods to application in CT image reconstruction. The second half goes in depth on this subject and discusses the link between object sparsity and sufficient sampling for accurate reconstruction. Par...

  10. Discretization of topological spaces

    OpenAIRE

    Amini, Massoud; Golestani, Nasser

    2014-01-01

    There are several compactification procedures in topology, but there is only one standard discretization, namely, replacing the original topology with the discrete topology. We give a notion of discretization which is dual (in categorical sense) to compactification and give examples of discretizations. Especially, a discretization functor from the category of $\\alpha$-scattered Stonean spaces to the category of discrete spaces is constructed which is the converse of the Stone-\\v{C}ech compact...

  11. How to Ensure Low Radon Concentrations in Indoor Environments

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn; Wraber, Ida Kristina

    2011-01-01

    This paper focuses on methods for measuring radon levels in the indoor air in buildings as well as on concrete solutions that can be carried out in the building to prevent radon leakage and to lower the radon concentration in the indoor air of new buildings. The radon provision in the new Danish...... Building Regulations from 2010 has been tightened as a result of new recommendations from the World Health Organization. Radon can cause lung cancer and it is not known whether there is a lower limit for its harmfulness. It is therefore important to reduce the radon concentration as much as possible in new...... buildings. The airtightness is a major factor when dealing with radon in buildings. Above the ground it is important to build airtight in compliance with energy requirements and against the ground it is important to prevent radon from seeping into the building. There is a direct connection between...

  12. Radon exhalation rates of some granites used in Serbia

    Directory of Open Access Journals (Sweden)

    Nikolić Mladen D.

    2015-01-01

    Full Text Available In order to address concern about radon exhalation in building material, radon exhalation rate was determined for different granites available on Serbian market. Radon exhalation rate, along with mass exhalation rate and effective radium content were determined by closed chamber method and active continuous radon measurement technique. For this research, special chambers were made and tested for back diffusion and leakage, and the radon concentrations measured were included in the calculation of radon exhalation. The radon exhalation rate ranged from 0.161 Bq/m2h to 0.576 Bq/m2h, the mass exhalation rate from 0.167 Bq/kgh to 0.678 Bq/kgh, while the effective radium content was found to be from 12.37 Bq/kg to 50.23 Bq/kg. The results indicate that the granites used in Serbia have a low level of radon exhalation.

  13. Radon removal from gaseous xenon with activated charcoal

    Science.gov (United States)

    Abe, K.; Hieda, K.; Hiraide, K.; Hirano, S.; Kishimoto, Y.; Kobayashi, K.; Koshio, Y.; Liu, J.; Martens, K.; Moriyama, S.; Nakahata, M.; Nishiie, H.; Ogawa, H.; Sekiya, H.; Shinozaki, A.; Suzuki, Y.; Takachio, O.; Takeda, A.; Ueshima, K.; Umemoto, D.; Yamashita, M.; Hosokawa, K.; Murata, A.; Otsuka, K.; Takeuchi, Y.; Kusaba, F.; Motoki, D.; Nishijima, K.; Tasaka, S.; Fujii, K.; Murayama, I.; Nakamura, S.; Fukuda, Y.; Itow, Y.; Masuda, K.; Nishitani, Y.; Takiya, H.; Uchida, H.; Kim, Y. D.; Kim, Y. H.; Lee, K. B.; Lee, M. K.; Lee, J. S.; Xmass Collaboration

    2012-01-01

    Many low background experiments using xenon need to remove radioactive radon to improve their sensitivities. However, no method of continually removing radon from xenon has been described in the literature. We studied a method to remove radon from xenon gas through an activated charcoal trap. From our measurements we infer a linear relationship between the mean propagation velocity vRn of radon and vXe of xenon in the trap with vRn/vXe=(0.96±0.10)×10-3 at -85 °C. As the mechanism for radon removal in this charcoal trap is its decay, knowledge of this parameter allows us to design an efficient radon removal system for the XMASS experiment. The verification of this system found that it reduces radon by a factor of 0.07, which is in line with its expected average retention time of 14.8 days for radon.

  14. Volume Effects in Discrete beta functions

    CERN Document Server

    Liu, Yuzhi; Zou, Haiyuan

    2011-01-01

    We calculate discrete beta functions corresponding to the two-lattice matching for the 2D O(N) models and Dyson's hierarchical model. We describe and explain finite-size effects such as the appearance of a nontrivial infrared fixed point that goes to infinity at infinite volume or the merging of an infrared and an ultraviolet fixed point. We present extensions of the RG flows to the complex coupling plane. We discuss the possibility of constructing a continuous beta function from the discrete one by using functional conjugation methods. We briefly discuss the relevance of these findings for the search of nontrivial fixed points in multiflavor lattice gauge theory models.

  15. Radon

    Science.gov (United States)

    ... face' showdown over Obama-era tailpipe rule Blog: Yoga, Tai Chi and Your Lungs: The Benefits of ... list_name').hide(); } $("#local_list_xml").quickPagination(); }, error: function() { console.log("An error occurred while processing XML ...

  16. Active versus passive radon monitoring at the Yucca Mountain site

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, M.D. [Science Applications International Corp., Las Vegas, NV (United States)

    1994-12-31

    Federal Regulations have mandated that a baseline assessment for the Yucca Mountain Site be performed. This includes the detection and monitoring of specific radionuclides present at the site. These radionuclides include radon 222, a decay progeny of naturally occurring uranium. Two radon monitoring systems are utilized at the Yucca Mountain site to detect ambient levels of radon. The first is a passive time integrated system, and the second is a continuous radon monitoring (CRM) system.

  17. The reliability of radon as seismic precursor

    Science.gov (United States)

    Emilian Toader, Victorin; Moldovan, Iren Adelina; Ionescu, Constantin; Marmureanu, Alexandru

    2016-04-01

    Our multidisciplinary network (AeroSolSys) located in Vrancea (Curvature Carpathian Mountains) includes radon concentration monitoring in five stations. We focus on lithosphere and near surface low atmosphere phenomena using real-time information about seismicity, + / - ions, clouds, solar radiation, temperature (air, ground), humidity, atmospheric pressure, wind speed and direction, telluric currents, variations of the local magnetic field, infrasound, variations of the atmospheric electrostatic field, variations in the earth crust with inclinometers, electromagnetic activity, CO2 concentration, ULF radio wave propagation, seismo-acoustic emission, animal behavior. The main purpose is to inform the authorities about risk situation and update hazard scenarios. The radon concentration monitoring is continuously with 1 hour or 3 hours sample rate in locations near to faults in an active seismic zone characterized by intermediate depth earthquakes. Trigger algorithms include standard deviation, mean and derivative methods. We correlate radon concentration measurements with humidity, temperature and atmospheric pressure from the same equipment. In few stations we have meteorological information, too. Sometime the radon concentration has very high variations (maxim 4535 Bq/m3 from 106 Bq/m3) in short time (1 - 2 days) without being accompanied by an important earthquake. Generally the cause is the high humidity that could be generated by tectonic stress. Correlation with seismicity needs information from minimum 6 month in our case. For 10605 hours, 618 earthquakes with maxim magnitude 4.9 R, we have got radon average 38 Bq/m3 and exposure 408111 Bqh/m3 in one station. In two cases we have correlation between seismicity and radon concentration. In other one we recorded high variation because the location was in an area with multiple faults and a river. Radon can be a seismic precursor but only in a multidisciplinary network. The anomalies for short or long period of

  18. Discrete Curvatures and Discrete Minimal Surfaces

    KAUST Repository

    Sun, Xiang

    2012-06-01

    This thesis presents an overview of some approaches to compute Gaussian and mean curvature on discrete surfaces and discusses discrete minimal surfaces. The variety of applications of differential geometry in visualization and shape design leads to great interest in studying discrete surfaces. With the rich smooth surface theory in hand, one would hope that this elegant theory can still be applied to the discrete counter part. Such a generalization, however, is not always successful. While discrete surfaces have the advantage of being finite dimensional, thus easier to treat, their geometric properties such as curvatures are not well defined in the classical sense. Furthermore, the powerful calculus tool can hardly be applied. The methods in this thesis, including angular defect formula, cotangent formula, parallel meshes, relative geometry etc. are approaches based on offset meshes or generalized offset meshes. As an important application, we discuss discrete minimal surfaces and discrete Koenigs meshes.

  19. RESOLVING THE RADON PROBLEM IN CLINTON, NEW JERSEY HOUSES

    Science.gov (United States)

    The paper discusses the resolution of a radon problem in Clinton, New Jersey, where significantly elevated radon concentrations were found in several adjacent houses. The U.S. EPA screened 56 of the houses and selected 10 for demonstration of radon reduction techniques. Each of t...

  20. RESOLVING THE RADON PROBLEM IN CLINTON, NEW JERSEY HOUSES

    Science.gov (United States)

    The paper discusses the resolution of a radon problem in Clinton, New Jersey, where significantly elevated radon concentrations were found in several adjacent houses. The U.S. EPA screened 56 of the houses and selected 10 for demonstration of radon reduction techniques. Each of t...

  1. Assessment of indoor radon gas concentration change of college

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hoon Hee; Jeong, Eui Hwan; Kim, Hak Jae; Lyu, Kang Yeul [Dept. of of Radiological Technology, Shingu College, Seongnam (Korea, Republic of); Lee, Ju Young [Dept. of Radiological Technology, Songho College, Hoengseong (Korea, Republic of)

    2017-03-15

    The purpose of this study was to assess the impact by comparing the concentration of indoor radon and look for ways to lower the concentration of indoor radon gas measurements of three variables, the year of completion, volume of the building and ventilation. Measurement target is six classrooms on the sixth floor of building that was constructed in 1973 and was extended in 2011. Selected classroom's volume is different. Four classrooms were selected to compare the radon concentration in accordance with the year of completion, Classrooms that is same year of completion were selected to compare the radon concentration in accordance with the volume, six classroom was performed closure and ventilation to compare radon concentration according to ventilation. Radon concentrations in accordance with the year of building completion showed a high concentration of radon in a building recently built. Also, Radon concentration in volume is high the smaller the volume. Radon concentration change according to ventilation showed a reduction of about 80% when the ventilation than during closing. Especially, The radon concentrations were high detected while the recently year of building completion and the smaller volume. Ventilation of the three variables is considered that can be expected to exposure reduction effect by radon affecting the greatest radon concentration reduction.

  2. From Complex Fractional Fourier Transform to Complex Fractional Radon Transform

    Institute of Scientific and Technical Information of China (English)

    FAN Hong-Yi; JIANG Nian-Quan

    2004-01-01

    We show that for n-dimensional complex fractional Fourier transform the corresponding complex fractional Radon transform can also be derived, however, it is different from the direct product of two n-dimensional real fractional Radon transforms. The complex fractional Radon transform of two-mode Wigner operator is calculated.

  3. A prediction model for assessing residential radon concentration in Switzerland

    NARCIS (Netherlands)

    Hauri, D.D.; Huss, A.; Zimmermann, F.; Kuehni, C.E.; Roosli, M.

    2012-01-01

    Indoor radon is regularly measured in Switzerland. However, a nationwide model to predict residential radon levels has not been developed. The aim of this study was to develop a prediction model to assess indoor radon concentrations in Switzerland. The model was based on 44,631 measurements from the

  4. 40 CFR 61.203 - Radon monitoring and compliance procedures.

    Science.gov (United States)

    2010-07-01

    ..., each owner or operator of an inactive phosphogypsum stack shall test the stack for radon-222 flux in... the radon-222 flux testing. Each report shall also include the following information: (i) The name and... provide EPA with a report detailing the actions taken and the results of the radon-222 flux testing....

  5. Fractional Radon Transform and Transform of Wigner Operator

    Institute of Scientific and Technical Information of China (English)

    FAN Hong-Yi; CHEN Jun-Hua

    2003-01-01

    Based on the Radon transform and fractional Fourier transform we introduce the fractional Radon trans-formation (FRT). We identify the transform kernel for FRT. The FRT of Wigner operator is derived, which naturallyreduces to the projector of eigenvector of the rotated quadrature in the usual Radon transform case.

  6. The latest trend of the research on radon

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, Hiroshi [Science Univ. of Tokyo, Noda, Chiba (Japan). Faculty of Science and Technology

    1996-12-01

    In June, 1995, the international conference of sixth Natural Radiation Environment was held in Montreal. More than 80% of more than 200 published researches were concerned with radon and thoron. The participants came from 32 countries. The classification of the research on radon and the number of the publication are shown. The contents of the researches in respective items of measuring method, concentration level and dose evaluation, indoor model and indoor and outdoor radon balance, the countermeasures for reducing indoor radon, radon potential, dose evaluation model, the particle size distribution of aerosol including the particle size distribution of free daughter nuclides and radon in the atmosphere are described. The research on the radon in water is excluded. The most remarkable trend is the theme of radon potential. The trend of connecting the research on radon in soil and the research on dissipation rate to radon potential and the forecast of indoor and outdoor radon concentration seems to become stronger. As to the research on concentration level, the detection of hot spots and the supplementary measurement for clarifying cause are carried out in the advanced countries concerning radon based on the results of survey in whole country. The researches in schools are conspicuous. (K.I.)

  7. Compilation of geogenic radon potential map of Pest County, Hungary

    Science.gov (United States)

    Szabó, K. Zs.; Pásztor, L.; Horváth, Á.; Bakacsi, Zs.; Szabó, J.; Szabó, Cs.

    2010-05-01

    222Rn and its effect on the human health have recently received major importance in environmental studies. This natural radioactive gas accounts for about 9% of lung cancer death and about 2% of all deaths from cancer in Europe due to indoor radon concentrations. It moves into the buildings from the natural decay chain of uranium in soils, rocks and building materials. Radon mapping regionalizes the average hazard from radon in a selected area as a radon risk map. Two major methods (concerning the applied radon data) have been used for mapping. One uses indoor radon data whereas the other is based on soil gas radon data. The outputs of the second approach are the geogenic radon potential maps. The principal objective of our work is to take the first step in geogenic radon mapping in Hungary. Soil samples collected in Pest County (Central Region of Hungary) in the frame of a countrywide soil survey (Soil Information and Monitoring System) were studied to have empirical information of the potential radon risk. As the first two steps radium concentration of soil samples, collected at 43 locations sampling soil profiles by genetic horizons from the surface level down to 60-150 cm, were determined using HPGe gamma-spectroscopy technique, as well as measurement of radon exhalation on the soil samples were carried out applying closed radon accumulation chamber coupled with RAD7 radon monitor detector. From these data the exhalation coefficient was calculated, which shows how many percent of the produced radon can come out from the sample. This rate strongly depends on the depth: at circa 100 cm a drastic decrease have been noticed, which is explained by the change in soil texture. The major source of indoor radon is the soil gas radon concentration (Barnet et al., 2005). We estimated this value from the measured radon exhalation and calculated soil porosity and density. The soil gas radon concentration values were categorized after Kemski et al. (2001) and then the

  8. Radon as a groundwater tracer in Forsmark and Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Grolander, Sara

    2009-10-15

    Radon concentrations were measured in different water types in Forsmark and Laxemar during the site investigation and within this study. From these measurements it can be concluded that large differences between surface water, near surface groundwater and deep groundwater can be found in both Laxemar and Forsmark. The differences in radon concentrations between different water types are used in this study to detect interactions between surface water, near surface water and deep groundwater. From the radon measurements it can also be concluded that radon concentration in deep groundwater varies largely with depth. These variations with depth are probably caused by groundwater flow in conductive fracture zones in the bedrock. The focus of this study has been the radon concentration of near surface groundwater and the interaction between near surface groundwater and deep groundwater. Radon measurements have been done using the RAD-7 radon detector within this study. It could be concluded that RAD-7 is a good technique for radon measurements and also easy to use in field. The radon concentrations measured in near surface groundwater in Laxemar within this study were low and homogenous. The variation in radon concentration has been analyses and compared to other parameters. Since the hypothesis of this study has been that there are differences in radon concentrations between recharging and discharging groundwater, the most important parameter to consider is the recharge/discharge field classification of the wells. No correlation between the recharge/discharge classifications of wells and the radon concentrations were found. The lack of correlation between groundwater flow patterns and radon concentration means that it is not possible to detect flow patterns in near surface groundwater using radon as a tracer in the Laxemar area. The lack of correlation can be caused by the fact that there are just a few wells located in areas classified as recharge area. It can also be

  9. Metrology of the radon in air volume activity at the italian radon reference chamber

    Energy Technology Data Exchange (ETDEWEB)

    Sciocchetti, G.; Cotellessa, G.; Soldano, E.; Pagliari, M. [Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti, ENEA Centro Ricerche Casaccia Roma (Italy)

    2006-07-01

    The approach of the Italian National Institute of Ionising Radiations (I.N.M.R.I.-ENEA) on radon metrology has been based on a complete and integrated system which can be used to calibrate the main types of {sup 222}Rn in air measuring instruments with international traceability. The Italian radon reference chamber is a research and calibration facility developed at the Casaccia Research Center in Roma. This facility has an inner volume of one m{sup 3}. The wall is a cylindrical stainless steel vessel coupled with an automated climate apparatus operated both at steady and dynamic conditions. The control and data acquisition equipment is based on Radotron system, developed to automate the multitasking management of different sets of radon monitors and climatic sensors. A novel approach for testing passive radon monitors with an alpha track detector exposure standard has been developed. It is based on the direct measurement of radon exposure with a set of passive integrating monitors based on the new ENEA piston radon exposure meter. This paper describes the methodological approach on radon metrology, the status-of-art of experimental apparatus and the standardization procedures. (authors)

  10. Radon in soil gas in Kosovo.

    Science.gov (United States)

    Kikaj, Dafina; Jeran, Zvonka; Bahtijari, Meleq; Stegnar, Peter

    2016-11-01

    An assessment of the radiological situation due to exposure to radon and gamma emitting radionuclides was conducted in southern Kosovo. This study deals with sources of radon in soil gas. A long-term study of radon concentrations in the soil gas was carried out using the SSNTDs (CR-39) at 21 different locations in the Sharr-Korabi zone. The detectors were exposed for an extended period of time, including at least three seasonal periods in a year and the sampling locations were chosen with respect to lithology. In order to determine the concentration of the natural radioactive elements (238)U and (226)Ra, as a precursor of (222)Rn, soil samples were collected from each measuring point from a depth of 0.8 m, and measured by gamma spectrometry. The levels (Bq kg(-1)) of naturally occurring radionuclides and levels (kBq m(-3)) of radon in soil gas obtained at a depth 0.8 m of soil were: 21-53 for (226)Ra, 22-160 for (238)U and 0.295-32 for (222)Rn. With respect to lithology, the highest value for (238)U and (226)Ra were found in limestone and the highest value for (222)Rn was found in metamorphic rocks. In addition, the results showed seasonal variations of the measured soil gas radon concentrations with maximum concentration in the spring months. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Indoor radon concentrations in Adana, Turkey.

    Science.gov (United States)

    Degerlier, M; Celebi, N

    2008-01-01

    The indoor radon concentration in Adana, Turkey was measured in living rooms of 52 houses during winter 2005 and 57 houses during summer 2005. Forty-four houses were selected for both winter and summer researches for estimating seasonal variations. Indoor radon concentrations were measured seasonally over hotter and colder 2 months over the whole year, using CR-39 passive nuclear track radon detectors. The radon concentrations were ranged from 15 to 97 Bq m(-3) on January-February 2005 for 60 d and from 5 to 70 Bq m(-3) on June-July 2005 for 60 d. The average summer concentration measured was 25.8 Bq m(-3) and the average winter concentration was 48.9 Bq m(-3) in 44 houses that observed seasonal variations. The differences between winter and summer periods were ranged from 1 to 77 Bq m(-3). The average value in both winter and summer periods is 37 Bq m(-3) in 44 houses that observed seasonal variations. This value is below the worldwide indoor radon concentration distribution of 46 Bq m(-3). The annual effective dose equivalent from (222)Rn was 0.9 mSv y(-1).

  12. Radon measurements with a PIN photodiode

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Martin, A. [Laboratorio de Investigacion en Baja Radiactividad (LIBRA), Edificio I-D, Campus Miguel Delibes, Universidad de Valladolid, Valladolid 47011 (Spain) and Departamento de Fisica Teorica, Atomica y Optica, Universidad de Valladolid, Valladolid 47011 (Spain)]. E-mail: alonsomm@libra.uva.es; Gutierrez-Villanueva, J.L. [Laboratorio de Investigacion en Baja Radiactividad (LIBRA), Edificio I-D, Campus Miguel Delibes, Universidad de Valladolid, Valladolid 47011 (Spain); Departamento de Fisica Teorica, Atomica y Optica, Universidad de Valladolid, Valladolid 47011 (Spain); Munoz, J.M. [Departamento de Electricidad y Electronica, Universidad de Valladolid, Valladolid 47011 (Spain); Garcia-Talavera, M. [Laboratorio de Investigacion en Baja Radiactividad (LIBRA), Edificio I-D, Campus Miguel Delibes, Universidad de Valladolid, Valladolid 47011 (Spain); Departamento de Fisica Teorica, Atomica y Optica, Universidad de Valladolid, Valladolid 47011 (Spain); Adamiec, G. [Departamento de Fisica Teorica, Atomica y Optica, Universidad de Valladolid, Valladolid 47011 (Spain); Iniguez, M.P. [Departamento de Fisica Teorica, Atomica y Optica, Universidad de Valladolid, Valladolid 47011 (Spain)

    2006-10-15

    Silicon photodiodes are well suited to detect alphas coming from different sources as neutron reactions or radon daughters. In this work a radon in air detecting device, using an 18x18 mm silicon PIN photodiode is studied. The ionized airborne decay products formed during radon diffusion were focused by an accelerating high voltage to the PIN surface. Several conducting rings were disposed inside a cylindrical PVC vessel in such a way that they reproduced the electric field created by a punctual charge located behind PIN position. Alpha spectra coming from the neutral and ionized species deposited on the PIN surface, dominated by {sup 218}Po and {sup 214}Po progeny peaks, were recorded for varying conditions. Those include radon concentration from a Pylon source, high voltage (thousands of volts) and PIN inverse bias voltage. Different parameters such as temperature and humidity were also registered during data acquisition. The increase in the particle collection efficiency with respect to zero electric field was compared with the corresponding to a parallel plates configuration. A discussion is made in terms of the most appropriate voltages for different radon concentrations.

  13. Radon monitoring in Bologna (Italy) homes

    Energy Technology Data Exchange (ETDEWEB)

    Beozzo, M.; Bottazzi, E.; Degli Esposti, L.; Folesani, M.; Frassinetti, J.; Giacomelli, G.; Lembo, L.; Maltoni, G.; Massera, F.; Nicoli, F. (Bologna Univ. (Italy). Dept. di Fisica ENEA Centro Ricerche Energia, Bologna (Italy). Area Energia, Ambiente e Salute Istituto Nazionale di Fisica Nucleare, Bologna (Italy))

    1991-01-01

    This paper first reviews the origin and behaviour of naturally present radon gas which is thought to account for more than 50% of radiation doses derived from natural radioactivity and deemed responsible for increased risk of lung cancer. An analysis is made of the many factors influencing radon concentration levels in residential buildings. These include such factors as the presence of thermal bridges, type of ventilation and seasonal climatic variations. In addition, since the density of radon is eight times greater than that of air, concentration levels vary greatly according to room height above ground level. The paper then reports on a home radon monitoring campaign conducted by ENEA (Italian Commission for New Technologies, Energy and Environment) with the aim of providing sufficient and accurate information to public health authorities to enable them to set up and implement effective radiation protection policies. The monitoring was done with two methods to allow comparisons to be made. One was based on the use of a passive nuclear trace detector (CR-39), the other, based on the use of gas adsorption by activated carbon. Results with the two methods agreed well and only modest amounts of indoor radon were detected.

  14. RADON MITIGATION IN SCHOOLS: CASE STUDIES OF RADON MITIGATION SYSTEMS INSTALLED BY EPA IN FOUR MARYLAND SCHOOLS ARE PRESENTED

    Science.gov (United States)

    The first part of this two-part paper discusses radon entry into schools, radon mitigation approaches for schools, and school characteristics (e.g., heating, ventilation, and air-conditioning -- HVAC-- system design and operation) that influence radon entry and mitigation system ...

  15. RADON MITIGATION IN SCHOOLS: CASE STUDIES OF RADON MITIGATION SYSTEMS INSTALLED BY EPA IN FOUR MARYLAND SCHOOLS ARE PRESENTED

    Science.gov (United States)

    The first part of this two-part paper discusses radon entry into schools, radon mitigation approaches for schools, and school characteristics (e.g., heating, ventilation, and air-conditioning -- HVAC-- system design and operation) that influence radon entry and mitigation system ...

  16. Determination of Radon concentration in air using scinti-cell radon monitor

    Energy Technology Data Exchange (ETDEWEB)

    Koga, Taeko [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst; Morishima, Hiroshige; Arai, Naoki; Shiraishi, Masatoshi; Shigehara, Makiko [Dept. of Nuclear Engineering, School of Science and Technology, Kinki Univ., Higashi-Osaka, Osaka(Japan); Mifune, Masaaki

    2000-01-01

    This study is carried out the methodology characteristics of {sup 222}Rn (Radon) concentration in air using the scinti-cell radon monitor (Trace environmental level detector (PMT-TEL) and Lucas cell (300 A), Pylon Co. and the determination of Radon concentrations in air on Misasa spa area in Tottori pref. and Ikeda spa in Shimane pref. on November 1995 and 1996. We have reached to the following results; (1) Minimum detectable Radon concentrations in air using the scinti-cell monitor are 7.6 Bq/m{sup 3} with 23% of accuracy (relative standard deviation) on the grab sampling of Lucas cell and 0.58 Bq/m{sup 3} with that of 17% on the continuous measuring of PMT-TEL, when it measured after 3.5 hours on the air sampling to determine the mean radon concentrations. The radon concentrations by the PMT-TEL method is about ten times more detectable than those by Lucas cell, that the former is the most sensitive among the detectors used on this research and is able to detect low level environmental concentrations, particularly outdoor and the later is valuable to use conveniently and portably on grab spot sampling of high level radon concentrations indoor air. (2) On the comparison of characteristics on spot monitoring of radon in air, a pico-rad method is suitable for the determination of the mean concentration for continuous sampling period by PMT-TEL and Lucas cell 300 A, and the variation of radon concentration can be observed on elapse of time course. (author)

  17. Radon exhalation rates corrected for leakage and back diffusion – Evaluation of radon chambers and radon sources with application to ceramic tile

    Directory of Open Access Journals (Sweden)

    M. Abo-Elmagd

    2014-10-01

    Full Text Available The natural radon decay, leakage and back diffusion are the main removal processes of radon from its container. Ignoring these processes leads to underestimate the measured value of radon related parameters like exhalation rate and radium content. This work is aimed to evaluate two different radon chambers through determining their leakage rate λv and evaluation of radon source by determine its back diffusion rate λb inside the evaluated radon chambers as well as a small sealed cup. Two different methods are adapted for measuring both the leakage rate and the back diffusion rate. The leakage rate can be determined from the initial slope of the radon decay curve or from the exponential fitting of the whole decay curve. This can be achieved if a continuous monitoring of radon concentration inside the chamber is available. Also, the back diffusion rate is measured by sealing the radon source in the chamber and used the initial slope of the buildup curve to determine λb and therefore the exhalation rate of the source. This method was compared with simple equation for λb based on the ratio of the source to the chamber volume. The obtained results are applied to ceramic tile as an important radon source in homes. The measurement is targeted the ceramic glaze before and after firing as well as the obtained tile after adhere the glaze on the tile main body. Also, six different tile brands from Egyptian market are subjected to the study for comparison.

  18. Multagenicity of radon and radon daughters. Final technical report, January 1, 1993--December 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Evans, H.H.

    1997-06-01

    The objective of this research was to investigate the dose-response relationship with regard to the lethal and mutagenic effects of exposure of cells to radon and its decay products. Dose-rate dependence was studied, as well as the nature of the DNA lesions. The effect of DNA repair on the lethal and mutagenic effects of exposure and on the character of the DNA lesions was investigated by comparing the response of L5178Y strains that differ in their ability to rejoin X radiation-induced DNA double strand breaks. The nature of radon/radon daughter-induced mutational lesions in human lymphoblasts was also investigated.

  19. The use of track registration detectors to reconstruct contemporary and historical airborne radon ( sup 2 sup 2 sup 2 Rn) and radon progeny concentrations for a radon-lung cancer epidemiologic study

    CERN Document Server

    Steck, D J

    1999-01-01

    Epidemiologic studies that investigate the relationship between radon and lung cancer require accurate estimates for the long-term average concentrations of radon progeny in dwellings. Year-to-year and home-to-home variations of radon in domestic environments pose serious difficulties for reconstructing an individual's long-term radon-related exposure. The use of contemporary radon gas concentrations as a surrogate for radon-related dose introduces additional uncertainty in dose assessment. Studies of glass exposed in radon chambers and in a home show that radon progeny deposited on, and implanted in, glass hold promise for reconstructing past radon concentrations in a variety of atmospheres. We developed an inexpensive track registration detector for the Iowa Radon Lung Cancer Study (IRLCS) that simultaneously measures contemporary airborne radon concentrations, surface deposited alpha activity density, and implanted sup 2 sup 1 sup 0 Po activity density. The implanted activity is used to reconstruct the cum...

  20. Residential radon in Finland: sources, variation, modelling and dose comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Arvela, H.

    1995-09-01

    The study deals with sources of indoor radon in Finland, seasonal variations in radon concentration, the effect of house construction and ventilation and also with the radiation dose from indoor radon and terrestrial gamma radiation. The results are based on radon measurements in approximately 4000 dwellings and on air exchange measurements in 250 dwellings as well as on model calculations. The results confirm that convective soil air flow is by far the most important source of indoor radon in Finnish low-rise residential housing. (97 refs., 61 figs., 30 tabs.).

  1. Indoor radon and decay products: Concentrations, causes, and control strategies

    Energy Technology Data Exchange (ETDEWEB)

    Nero, A.V.; Gadgil, A.J.; Nazaroff, W.W.; Revzan, K.L.

    1990-11-01

    This report is another in the on going technical report series that addresses various aspects of the DOE Radon Research Program. It provides an overview of what is known about the behavior of radon and its decay products in the indoor environment and examines the manner in which several important classes of factors -- structural, geological, and meteorological -- affect indoor radon concentrations. Information on US indoor radon concentrations, currently available monitoring methods and novel radon control strategies are also explored. 238 refs., 22 figs., 9 tabs.

  2. Measurement of soil and indoor radon in Italy

    Energy Technology Data Exchange (ETDEWEB)

    Torri, G.; Azimi-Garakani, D.; Oppon, O.C.; Piermattei, S.; Susanna, A.F.; Seidel, J.-L.; Tommasino, L.; Ardanese, L. (ENEA, Rome (Italy))

    1988-01-01

    In spite of the fact that in the majority of cases the most important radon source is the soil and the rock beneath the house, no large scale survey of soil radon has ever been made in Italy. In this paper the results of a large scale survey of soil radon are presented from measurements made in hundreds of different sites in Latium and Campania. For several locations, results of measurements gathered for different years are described and up-dated. As a pilot project for indoor radon survey monthly variations of radon concentrations in typical houses have been investigated. (author).

  3. Onboard hierarchical network

    Science.gov (United States)

    Tunesi, Luca; Armbruster, Philippe

    2004-02-01

    The objective of this paper is to demonstrate a suitable hierarchical networking solution to improve capabilities and performances of space systems, with significant recurrent costs saving and more efficient design & manufacturing flows. Classically, a satellite can be split in two functional sub-systems: the platform and the payload complement. The platform is in charge of providing power, attitude & orbit control and up/down-link services, whereas the payload represents the scientific and/or operational instruments/transponders and embodies the objectives of the mission. One major possibility to improve the performance of payloads, by limiting the data return to pertinent information, is to process data on board thanks to a proper implementation of the payload data system. In this way, it is possible to share non-recurring development costs by exploiting a system that can be adopted by the majority of space missions. It is believed that the Modular and Scalable Payload Data System, under development by ESA, provides a suitable solution to fulfil a large range of future mission requirements. The backbone of the system is the standardised high data rate SpaceWire network http://www.ecss.nl/. As complement, a lower speed command and control bus connecting peripherals is required. For instance, at instrument level, there is a need for a "local" low complexity bus, which gives the possibility to command and control sensors and actuators. Moreover, most of the connections at sub-system level are related to discrete signals management or simple telemetry acquisitions, which can easily and efficiently be handled by a local bus. An on-board hierarchical network can therefore be defined by interconnecting high-speed links and local buses. Additionally, it is worth stressing another important aspect of the design process: Agencies and ESA in particular are frequently confronted with a big consortium of geographically spread companies located in different countries, each one

  4. Hierarchically Organized Behavior and Its Neural Foundations: A Reinforcement Learning Perspective

    Science.gov (United States)

    Botvinick, Matthew M.; Niv, Yael; Barto, Andrew C.

    2009-01-01

    Research on human and animal behavior has long emphasized its hierarchical structure--the divisibility of ongoing behavior into discrete tasks, which are comprised of subtask sequences, which in turn are built of simple actions. The hierarchical structure of behavior has also been of enduring interest within neuroscience, where it has been widely…

  5. Hierarchically Organized Behavior and Its Neural Foundations: A Reinforcement Learning Perspective

    Science.gov (United States)

    Botvinick, Matthew M.; Niv, Yael; Barto, Andrew C.

    2009-01-01

    Research on human and animal behavior has long emphasized its hierarchical structure--the divisibility of ongoing behavior into discrete tasks, which are comprised of subtask sequences, which in turn are built of simple actions. The hierarchical structure of behavior has also been of enduring interest within neuroscience, where it has been widely…

  6. The European radon mapping project

    Energy Technology Data Exchange (ETDEWEB)

    Bossew, P., E-mail: pbossew@bfs.de [German Federal Office for Radiation Protection, Berlin (Germany); Tollefsen, T.; Gruber, V.; De Cort, M., E-mail: tore.tollefsen@jrc.ec.europa.eu, E-mail: valeria.gruber@gmail.com, E-mail: marc.de-cort@jrc.ec.europa.eu [Institute for Transuranium Elements, Ispra, VA (Italy). DG Joint Research Centre. European Commission

    2013-07-01

    There is almost unanimous agreement that indoor radon (Rn) represents a hazard to human health. Large-scale epidemiological studies gave evidence that Rn is the second-most important cause o flung cancer after smoking and that also relatively low Rn concentrations can be detrimental. This has increasingly led to attempts to limit Rn exposure through regulation, mainly building codes. The proposed Euratom Basic Safety Standards (BSS) require Member States to establish Rn action plans aimed at reducing Rn risk, and to set reference values for Imitating indoor Rn concentration. In 2006 the JRC started a project on mapping Rn at the European level, in addition and complementary lo (but not as a substitute for) national efforts. These maps are part of the European Atlas of Natural Radiation project. which is planned eventually 10 comprise geographical assessments of ali sources of exposure to natural radiation. Started first, a map of indoor Rn is now in an advanced phase, but still incomplete as national Rn surveys are ongoing in a number of European countries. A European map of geogenic Rn, conceptually and technically more complicated, was started in 2008. The main difficulty encountered is heterogeneity of survey designs, measurement and evaluation methods and database semantics and structures. An important part or the work on the Atlas is therefore to harmonize data and methods. We present the current state of the Rn maps and discuss some of the methodological challenges. (author)

  7. Turbidimetry for measurement of radon concentration

    Energy Technology Data Exchange (ETDEWEB)

    Wang Huanqiang [HuBei Provincial Academy of Medical Sciences, WuHan (China). Inst. of Radioactive Protection

    1993-12-31

    This paper describes a turbidimetric technique counting the tracks registered on CR-39 foils exposed to radon. Instead of eyeview through microscope, by using the differential spectrophotometer, strong correlation between the radon cumulative concentration and track turbidence was observed(r=0.999). Under the etching condition of 7.07 mol{center_dot}L{sup -1} KOH water solution at 80{sup o}C for 16 hr, linear regression showed that the ratio of track turbidence and cumulative concentration of radon exposure was 1.99 x 10{sup -1} turbidence (KBq m{sup -1}h){sup -1} and the determination limit was 36 KBq m{sup -3}h. The details of the experiments are represented in this paper. (Author).

  8. Radon barrier: Method of testing airtightness

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn; Buch-Hansen, Thomas Cornelius

    2017-01-01

    The test method NBI 167/02 Radon membrane: Test of airtightness can be used for determining the airtightness of a radon barrier as a system solution. The test determines the air infiltration through the radon barrier for a number of levels of air pressure differences. The airflow through versus...... the difference in air pressure over the barrier is measured. The air pressure difference is kept constant, at a number of manually controlled levels. At each pressure level, the difference is measured in a single point close to the point where the suction for lowering the air pressure is located. Improvements...... to the test method were suggested. A digital stirring and control system, and a method for determining the mean air pressure difference, as well as a method for testing barriers with a very low air infiltration, were provided. The digital stirring and control system ensured automatic control and measuring...

  9. Biological and therapeutical effects of Radon

    Energy Technology Data Exchange (ETDEWEB)

    Deetjen, P. [Institute of Physiologie and Balneologie, University of Innsbruck (Austria)

    1998-12-31

    In spas with a somewhat elevated Radon{sup 222} (Rn) activity (between 300 and 3000 Bq/l), the empirical medicine ended - in all parts of the world - with the same list of indications. It mainly includes the more painful rheumatic diseases such as deformation or degeneration of the joints and non bacterial inflammation of muscles, tendons or joints; Morbus Bechterew and other diseases of the vertebral column like spondylosis, spondylarthrosis or osteochondrosis. While informer times these effects were seldom documented in an objective manner, in recent years several prospective randomized double-blind studies proved the pain reducing efficacy of Radon therapy in patients with cervical pain syndromes, with chronic polyarthritis or with Morbus Bechterew. Studies in experimental animal models have accumulated remarkable data in organs, tissue and cultured cells that provide a rationale to explain the observed effects of Radon therapy in patients. (author)

  10. Geographical Correlations between Indoor Radon Concentration and Risks of Lung Cancer, Non-Hodgkin's Lymphoma, and Leukemia during 1999-2008 in Korea.

    Science.gov (United States)

    Ha, Mina; Hwang, Seung-Sik; Kang, Sungchan; Park, No-Wook; Chang, Byung-Uck; Kim, Yongjae

    2017-03-24

    Indoor radon is the second most important risk factor for lung cancer and may also be a risk factor for hematopoietic cancers, particularly in children and adolescents. The present study measured indoor radon concentration nationwide at 5553 points during 1989-2009 and spatially interpolated using lognormal kriging. The incidences of lung cancer, non-Hodgkin's lymphoma (NHL), and leukemia, stratified by sex and five-year age groups in each of the 234 administrative regions in the country during 1999-2008, were obtained from the National Cancer Registry and used to calculate the standardized incidence ratios. After considering regional deprivation index values and smoking rates by sex in each region as confounding variables, the cancer risks were estimated based on Bayesian hierarchical modeling. We found that a 10 Bq/m³ increase in indoor radon concentration was associated with a 1% increase in the incidence of lung cancer in male and a 7% increase in NHL in female children and adolescents in Korea aged less than 20 years. Leukemia was not associated with indoor radon concentration. The increase in NHL risk among young women requires confirmation in future studies, and the radon control program should consider children and adolescents.

  11. Indoor radon measurements and radon prognosis for the province of Kymi, southeastern Finland; Huoneilman radonmittaukset Kymen laeaenissae: Tilannekatsaus ja radonennuste

    Energy Technology Data Exchange (ETDEWEB)

    Pennanen, M.; Maekelaeinen, I.; Voutilainen, A.

    1996-12-01

    The purpose of the regional radon prognosis is to classify areas with different levels of radon risk. The radon prognosis gives the percentages of future homes expected to have indoor radon concentrations exceeding the levels of 200 and 400 Bq/m{sup 3}. It is assumed that no protection against the entry of radon is used in construction. In this study about 5900 indoor radon measurements made in single family houses, semi-detached houses and row houses were used. Data on the location, geology and construction of buildings were determined from maps and questionnaires. An empirical statistical model, the adjusted indoor radon measurements and geological data were used to assess the radon risk from soil and bedrock in different areas. The building sites of the province of Kymi were divided into thirteen sub-areas. The radon prognosis are calculated for the most radon-prone foundation types including (1) houses with a slab-on-grade and (2) houses with a basement or hillside houses with open stairwells between basement and first floor. The radon levels are generally greater in the western part of the area. The radon risk is highest in gravel-dominated esker areas in southwestern, western (in Pyhtaa, Kotka, Anjalankoski, litti, Valkeala) and central (Taipalsaari) parts of the area. The radon risk is also high in some bedrock and till areas, also in southwestern and western parts of the area. In these areas the level of 200 Bq/m{sup 3} will be exceeded in 80 % of new houses. About half of the future houses in these areas will have indoor radon concentrations exceeding 400 Bq/m{sup 3}. The radon risk is lowest in the eastern part of the province of Kymi in every soil type. In this area the level of 200 Bq/m{sup 3} will be exceeded in 30 % of new houses. Below 10 % will exceed 400 Bq/m{sup 3}. (orig.) (14 refs.).

  12. Radon concentration in houses over a closed Hungarian uranium mine

    Energy Technology Data Exchange (ETDEWEB)

    Somlai, Janos; Kovacs, Tibor [University of Veszprem Department of Radiochemistry, H-8200, Veszprem P.O.B.: 158 (Hungary); Gorjanacz, Zoran [Mecsek Ore Environmental Protection Co. H-7614, Pecs, P.O.B.: 121 (Hungary); Varhegyi, Andras [Mecsek-OEko Environmental Protection Co. H-7614, Pecs, P.O.B.: 121 (Hungary)

    2006-08-31

    High radon concentration (average 410 kBq m{sup -3}) has been measured in a tunnel of a uranium mine, located 15-55 m below the village of Kovagoszolos, Hungary. The mine was closed in 1997; the artificial ventilation of the tunnel was then terminated and recultivation works begun. In this paper, a study has been made as to whether the tunnel has an influence on the radon concentration of surface dwellings over the mining tunnel. At different distances from the surface projection of the mining tunnel, radon concentration, the gamma dose, radon exhalation and radon concentration of soil gas were measured. The average radon concentration in the dwellings was 483 Bq m{sup -3}. Significantly higher radon concentrations (average 667 Bq m{sup -3}) were measured in houses within +/-150 m from the surface projection of the mining tunnel +50 m, compared with the houses further than the 300-m belt (average 291 Bq m{sup -3}). The average radon concentration of the soil gas was 88.8 kBq m{sup -3}, the average radon exhalation was 71.4 Bq m{sup -2} s{sup -1} and higher values were measured over the passage as well. Frequent fissures crossing the passage and running up to the surface and the high radon concentration generated in the passage (average 410 kBq m{sup -3}) may influence the radon concentration of the houses over the mining tunnel. (author)

  13. Variation in residential radon levels in new Danish homes.

    Science.gov (United States)

    Bräuner, E V; Rasmussen, T V; Gunnarsen, L

    2013-08-01

    Radon-222 gas arises from the radioactive decay of radium-226 and has a half-life of 3.8 days. This gas percolates up through soil into buildings, and if it is not evacuated, there can be much higher exposure levels indoors than outdoors, which is where human exposure occurs. Radon exposure is classified as a human carcinogen, and new Danish homes must be constructed to ensure indoor radon levels below 100 Bq/m(3). Our purpose was to assess how well 200 newly constructed single detached homes perform according to building regulations pertaining to radon and identify the association between indoor radon in these homes and municipality, home age, floor area, floor level, basement, and outer wall and roof construction. Median (5-95 percentile) indoor radon levels were 36.8 (9.0-118) Bq/m(3) , but indoor radon exceeded 100 Bq/m(3) in 14 of these new homes. The investigated variables explained nine percent of the variation in indoor radon levels, and although associations were positive, none of these were statistically significant. In this study, radon levels were generally low, but we found that 14 (7%) of the 200 new homes had indoor radon levels over 100 Bq/m(3). More work is needed to determine the determinants of indoor radon.

  14. Calibration system for measuring the radon flux density.

    Science.gov (United States)

    Onishchenko, A; Zhukovsky, M; Bastrikov, V

    2015-06-01

    The measurement of radon flux from soil surface is the useful tool for the assessment of radon-prone areas and monitoring of radon releases from uranium mining and milling residues. The accumulation chambers with hollow headspace and chambers with activated charcoal are the most used devices for these purposes. Systematic errors of the measurements strongly depend on the geometry of the chamber and diffusion coefficient of the radon in soil. The calibration system for the attestation of devices for radon flux measurements was constructed. The calibration measurements of accumulation chambers and chambers with activated charcoal were conducted. The good agreement between the results of 2D modelling of radon flux and measurements results was observed. It was demonstrated that reliable measurements of radon flux can be obtained by chambers with activated charcoal (equivalent volume ~75 l) or by accumulation chambers with hollow headspace of ~7-10 l and volume/surface ratio (height) of >15 cm.

  15. Theoretical aspects of the design of a passive radon dosemeter.

    Science.gov (United States)

    Wilkinson, P; Saunders, B J

    1985-10-01

    Some mathematical aspects of the development and design of a passive radon dosemeter are considered. In particular, a mathematical model is presented that is concerned with the gaseous diffusion of radon into a confined region bounded by a plastic material of known diffusion coefficient. The relationship between the time-integrated radon concentrations, inside and outside a sealed plastic container are derived. Estimates of the exposure of people to radon can be made using the time integrated radon concentration inside a calibrated container containing a CR-39 etched-track device. As a consequence of the analysis, it is possible to design a passive radon dosemeter that will be accurate, resistant to moisture and whose response will be independent of rapid variations in radon concentration. The possibility of using a container of this type for the measurement of diffusion coefficients is discussed.

  16. The Radon Monitoring System in Daya Bay Reactor Neutrino Experiment

    CERN Document Server

    Chu, M C; Kwok, M W; Kwok, T; Leung, J K C; Leung, K Y; Lin, Y C; Luk, K B; Pun, C S J

    2016-01-01

    We developed a highly sensitive, reliable and portable automatic system (H$^{3}$) to monitor the radon concentration of the underground experimental halls of the Daya Bay Reactor Neutrino Experiment. H$^{3}$ is able to measure radon concentration with a statistical error less than 10\\% in a 1-hour measurement of dehumidified air (R.H. 5\\% at 25$^{\\circ}$C) with radon concentration as low as 50 Bq/m$^{3}$. This is achieved by using a large radon progeny collection chamber, semiconductor $\\alpha$-particle detector with high energy resolution, improved electronics and software. The integrated radon monitoring system is highly customizable to operate in different run modes at scheduled times and can be controlled remotely to sample radon in ambient air or in water from the water pools where the antineutrino detectors are being housed. The radon monitoring system has been running in the three experimental halls of the Daya Bay Reactor Neutrino Experiment since November 2013.

  17. Radon release from granites in south-west England

    CERN Document Server

    Poole, J

    2001-01-01

    accessory minerals. The enhancement of surface area was attributed to the alteration of feldspar to sericite. This has implications for the release of radon. It is thought that the large surface area provides a sink for the adsorption of radon, retaining it in the rock structure. This radon retention explains the paradoxical decline in radon release at small particle size/large specific surface area. Various mechanisms for radon emanation are discussed with reference to the Cornubian granites. It is shown that, based on the measured specific surface areas, inter-crystalline diffusion is a slow process and not a significant contributor to overall radon release (0.01%). Approximately 1% of the total radon produced can be attributed to direct recoil processes, based on the calculated recoil ranges (36 nm). The remainder was attributed to diffusion processes through crystal imperfections and dislocations. The microscopic scale model developed here is extended to the macroscopic scale through examination of the la...

  18. Indoor radon survey in dwellings of some regions in Yemen

    Energy Technology Data Exchange (ETDEWEB)

    Khayrat, A.H. E-mail: akhayrat@yahoo.com; Al-Jarallah, M.I.; Fazal-ur-Rehman, X.; Abu-Jarad, F

    2003-06-01

    Indoor radon survey in a total of 241 dwellings, distributed in some regions of Yemen was performed, using CR-39 based radon monitors. The objective of this radon survey is to get representative indoor radon data of three regions, namely Dhamar, Taiz and Hodeidah, situated at different altitudes above sea level. The radon concentrations varied from 3 to 270 Bq m{sup -3} with an average of 42 Bq m{sup -3}. It was found that the average radon concentration in the surveyed areas increases with altitudes. The highest average radon concentration of 59 Bq m{sup -3} was found in Dhamar city while the lowest average concentration of 8 Bq m{sup -3} was found in Hodeidah city.

  19. Recent developments in radon metrology: new aspects in the calibration of radon, thoron and progeny devices.

    Science.gov (United States)

    Röttger, A; Honig, A

    2011-05-01

    Due to the importance of reliable measurements of radon activity concentration, one of the past developments in metrology was applied to the field of radon, thus meeting two basic needs: (1) the harmonisation of metrology within the scope of the mutual recognition arrangement, an arrangement drawn up by the International Committee of Weights and Measures for the mutual recognition of national standards and of calibrations issued by national metrology institutes and (2) the increased demands of the European Atomic Energy Community (EURATOM) directive, transferred into national radiation protection regulations with regard to natural radioactivity and its quality-assured measurements. This paper gives an overview of typical technical procedures in the radon-measuring technique group of PTB, covering all aspects of reference atmospheres (primary standards) for radon, thoron and their respective progenies.

  20. Occupational exposure to radon in Australian Tourist Caves an Australian-wide study of radon levels

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, S.B.; Langroo, R.; Peggie, J.R. [Australian Radiation Laboratory. Yallambie, VIC (Australia); Lyons, R.G. [University of Auckland, Auckland, (New Zealand). Department of Physics; James, J.M. [University of Sydney, Sydney, NSW (Australia). Department of Chemisty

    1996-02-01

    The study described in this report sets out to determine which Australian show caves have long- term radon levels in excess of the proposed action level of 1000 Bq m{sup -3}. The collaborative study between the Australian Radiation Laboratory (ARL), the University of Sydney and the University of Auckland, was carried out with the support of a Research Grant from Worksafe Australia. The aims of this study were to measure radon levels for each season over a period of one year, at representative sites in all developed show caves around Australia, to determine yearly average radon levels for each cave tour, based on these site measurements, to estimate the radiation doses to the tour guides employed in these caves, and to identify caves with radon concentrations in excess of the action level. (authors) 7 refs., 10 tabs., 2 figs.

  1. From the similarities between neutrons and radon to advanced radon-detection and improved cold fusion neutron-measurements

    Science.gov (United States)

    Tommasino, L.; Espinosa, G.

    2014-07-01

    Neutrons and radon are both ubiquitous in the earth's crust. The neutrons of terrestrial origin are strongly related to radon since they originate mainly from the interactions between the alpha particles from the decays of radioactive-gas (namely Radon and Thoron) and the light nuclei. Since the early studies in the field of neutrons, the radon gas was used to produce neutrons by (α, n) reactions in beryllium. Another important similarity between radon and neutrons is that they can be detected only through the radiations produced respectively by decays or by nuclear reactions. These charged particles from the two distinct nuclear processes are often the same (namely alpha-particles). A typical neutron detector is based on a radiator facing a alpha-particle detector, such as in the case of a neutron film badge. Based on the similarity between neutrons and radon, a film badge for radon has been recently proposed. The radon film badge, in addition to be similar, may be even identical to the neutron film badge. For these reasons, neutron measurements can be easily affected by the presence of unpredictable large radon concentration. In several cold fusion experiments, the CR-39 plastic films (typically used in radon and neutron film-badges), have been the detectors of choice for measuring neutrons. In this paper, attempts will be made to prove that most of these neutron-measurements might have been affected by the presence of large radon concentrations.

  2. Radon progeny monitoring at the Eastern North Atlantic (ENA), Graciosa Island ARM facility and a potential earthquake precursory signal

    Science.gov (United States)

    Barbosa, Susana; Mendes, Virgilio B.; Azevedo, Eduardo B.

    2016-04-01

    associated with the occurrence of precipitation. The background level decreases slightly after these discrete events, apparently as a result of rain inhibiting the exhalation of radon from the soil to the atmosphere, but is in general very stable, fluctuating around 50 counts per minute (~0.5%). A notable exception occurred in 26 August 2015, when the background level dropped sharply by ~200 counts per minute (~2.5% variation). The potential precursory significance of this event, along with the interpretation of the phenomenon and possible association to other ancillary data, such as changes in GPS position components of a nearby continuous station and ionospheric total electron content, are discussed.

  3. Novel determination of radon-222 velocity in deep subsurface rocks and the feasibility to using radon as an earthquake precursor

    Science.gov (United States)

    Zafrir, Hovav; Ben Horin, Yochai; Malik, Uri; Chemo, Chaim; Zalevsky, Zeev

    2016-09-01

    A novel technique utilizing simultaneous radon monitoring by gamma and alpha detectors to differentiate between the radon climatic driving forces and others has been improved and used for deep subsurface investigation. Detailed long-term monitoring served as a proxy for studying radon movement within the shallow and deep subsurface, as well as for analyzing the effect of various parameters of the radon transport pattern. The main achievements of the investigation are (a) determination, for the first time, of the radon movement velocity within rock layers at depths of several tens of meters, namely, 25 m/h on average; (b) distinguishing between the diurnal periodical effect of the ambient temperature and the semidiurnal effect of the ambient pressure on the radon temporal spectrum; and (c) identification of a radon random preseismic anomaly preceding the Nuweiba, M 5.5 earthquake of 27 June 2015 that occurred within Dead Sea Fault Zone.

  4. Groupoids, Discrete Mechanics, and Discrete Variation

    Institute of Scientific and Technical Information of China (English)

    GUO Jia-Feng; JIA Xiao-Yu; WU Ke; ZHAO Wei-Zhong

    2008-01-01

    After introducing some of the basic definitions and results from the theory of groupoid and Lie algebroid,we investigate the discrete Lagrangian mechanics from the viewpoint of groupoid theory and give the connection between groupoids variation and the methods of the first and second discrete variational principles.

  5. On discrete cosine transform

    CERN Document Server

    Zhou, Jianqin

    2011-01-01

    The discrete cosine transform (DCT), introduced by Ahmed, Natarajan and Rao, has been used in many applications of digital signal processing, data compression and information hiding. There are four types of the discrete cosine transform. In simulating the discrete cosine transform, we propose a generalized discrete cosine transform with three parameters, and prove its orthogonality for some new cases. A new type of discrete cosine transform is proposed and its orthogonality is proved. Finally, we propose a generalized discrete W transform with three parameters, and prove its orthogonality for some new cases.

  6. Mimetic discretization methods

    CERN Document Server

    Castillo, Jose E

    2013-01-01

    To help solve physical and engineering problems, mimetic or compatible algebraic discretization methods employ discrete constructs to mimic the continuous identities and theorems found in vector calculus. Mimetic Discretization Methods focuses on the recent mimetic discretization method co-developed by the first author. Based on the Castillo-Grone operators, this simple mimetic discretization method is invariably valid for spatial dimensions no greater than three. The book also presents a numerical method for obtaining corresponding discrete operators that mimic the continuum differential and

  7. Systematic grid-wise radon concentration measurements and first radon map in Cyprus

    CERN Document Server

    Theodoulou, G; Parpottas, Y; 10.1016/j.radmeas.2012.03.019

    2012-01-01

    A systematic study of the indoor airborne radon concentration in the central part of the Nicosia district was conducted, using high-sensitivity active radon portable detectors of the type "RADIM3A". From a total of 108 measurements in 54 grids of 1 km^2 area each, the overall mean value is 20.6 \\pm 13.2 Bq m^-3 (A.M.\\pm S.D.). That is almost twice less than the corresponding average worldwide value. The radon concentration levels in drinking water were also measured in 24 sites of the residential district, using the high-sensitivity radon detector of the type "RADIM3W". The mean value obtained from these measurements is 243.8 \\pm 224.8 mBq L^-1, which is relatively low compared to the corresponding internationally accepted level. The associated annual effective dose rates to each measurement were also calculated and compared to the corresponding worldwide values. From the geographical coordinates of the measuring sites and the corresponding radon concentration values, the digital radon map of the central part...

  8. Discrete mathematics, discrete physics and numerical methods

    Directory of Open Access Journals (Sweden)

    Felice Iavernaro

    2007-12-01

    Full Text Available Discrete mathematics has been neglected for a long time. It has been put in the shade by the striking success of continuous mathematics in the last two centuries, mainly because continuous models in physics proved very reliable, but also because of the greater difficulty in dealing with it. This perspective has been rapidly changing in the last years owing to the needs of the numerical analysis and, more recently, of the so called discrete physics. In this paper, starting from some sentences of Fichera about discrete and continuous world, we shall present some considerations about discrete phenomena which arise when designing numerical methods or discrete models for some classical physical problems.

  9. Mathematical and computer tools of discrete dynamic modeling and analysis of complex systems in control loop

    CERN Document Server

    Bagdasaryan, Armen

    2008-01-01

    We present a method of discrete modeling and analysis of multilevel dynamics of complex large-scale hierarchical dynamic systems subject to external dynamic control mechanism. Architectural model of information system supporting simulation and analysis of dynamic processes and development scenarios (strategies) of complex large-scale hierarchical systems is also proposed.

  10. RADON REDUCTION IN A CRAWL SPACE HOUSE

    Science.gov (United States)

    Radon, a naturally occurring radioactive gas, is drawn from the soil into a house when low air pressure exists in the house. This is a commonplace environmental hazard in the United States, Canada, and northern Europe. The U.S. Environmental Protection Agency (EPA) is developing ...

  11. Protect Your Home and Family from Radon

    Science.gov (United States)

    DALLAS - (Jan. 11, 2016) Radon-the silent killer-is responsible for about 21,000 lung cancer deaths every year. The U.S. Environmental Protection Agency encourages Americans around the country to test their homes for this naturally occurring radioac

  12. Radon entry into a simple test structure

    DEFF Research Database (Denmark)

    Andersen, C.E.; Søgaard-Hansen, J.; Majborn, B.

    1992-01-01

    A simple test structure for studies of radon entry into houses has been constructed at a field site at Riso National Laboratory. It consists of a 40 1, stainless-steel cylinder placed in a 0.52 m deep quadratic excavation with a side length of 2.4 m. The excavation is lined with an airtight...

  13. Novel Radon Sub-Slab Suctioning System

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2013-01-01

    insulation layer located on top of a capillary-breaking layer) mounted in turn on stable ground. The new system of prefabricated lightweight elements consists of the capillary-breaking layer and a pressure-reduction zone which is working as the radonsuction zone. The radon-suctioning layer is formed from...

  14. RADON REDUCTION IN A CRAWL SPACE HOUSE

    Science.gov (United States)

    Radon, a naturally occurring radioactive gas, is drawn from the soil into a house when low air pressure exists in the house. This is a commonplace environmental hazard in the United States, Canada, and northern Europe. The U.S. Environmental Protection Agency (EPA) is developing ...

  15. Status of the European indoor radon map

    Energy Technology Data Exchange (ETDEWEB)

    Bossew, P.; Tollefsen, T.; De Cort, M. [European Commission, Joint Reserch Centre (JRC) (Italy). Inst. of Environment and Sustainability

    2009-07-01

    Since 2006 a harmonized European indoor radon map is under production. At the moment (June 2009) 15 European countries have contributed data, further input is expected. This article informs about historical and legal backgrounds of the project, outlines the technical procedure and presents some preliminary results. (orig.)

  16. Simulated equilibrium factor studies in radon chamber

    Energy Technology Data Exchange (ETDEWEB)

    Tiehchi Chu; Holing Liu [National Tsing Hua Univ., Hsinchu, Taiwan (China). Dept. of Nuclear Science

    1996-05-01

    A series of experiments have been conducted to study the influences of environmental parameters on the equilibrium factor. Most of them were carried out in a walk-in type chamber. The deposition velocity was calculated using the Jacobi model. The ranges of the environmental parameters studied in the experiments are humidity 30-90% r.h. and radon concentration 2-40 kBqm{sup -3}. The aerosol sources included electric fumigator, mosquito coil, incense, a cigarette with the particle concentration 2000-6500 cm{sup -3} and the attachment rate 10-350 h{sup -1}. The results of the experiment show that the equilibrium factor tends to decrease as the radon concentration increases. On the other hand, the equilibrium factor tends to increase as the humidity increases, and so is the increasing attachment rate. Of all the parameters mentioned above, the influence that aerosols have on the equilibrium factor is the predominant factor. The calculated deposition velocity for the unattached fraction of radon daughters tends to increase as the radon concentration increases. However, it tends to decrease as the humidity increases. (Author).

  17. Radon Transform for Finite Dimensional Hilbert Space

    CERN Document Server

    Revzen, M

    2012-01-01

    Finite dimensional, d, Hilbert space operators are underpinned with ?nite geometry. The analysis emphasizes a central role for mutual unbiased bases (MUB) states projectors. Interrelation among the Hilbert space operators revealed via their (?nite) dual a?ne plane geometry (DAPG) underpin- ning is studied and utilized in formulating a ?nite dimensional Radon transformation. The ?nite geometry required for our study is outlines.

  18. Low-cost Radon Reduction Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    Rose, William B. [Univ. of Illinois, Urbana-Champaign, IL (United States); Francisco, Paul W. [Univ. of Illinois, Urbana-Champaign, IL (United States); Merrin, Zachary [Univ. of Illinois, Urbana-Champaign, IL (United States)

    2015-09-01

    The U.S. Department of Energy's Building America research team Partnership for Advanced Residential Retrofits conducted a primary scoping study on the impact of air sealing between the foundation and the living space on radon transport reduction across the foundation and living space floor assembly. Fifteen homes in the Champaign, Illinois, area participated in the study. These homes were instrumented for hourly continuous radon measurements and simultaneous temperature and humidity measurements. Blower door and zone pressure diagnostics were conducted at each house. The treatments consisted of using air-sealing foams at the underside of the floor that separated the living space from the foundation and providing duct sealing on the ductwork that is situated in the foundation area. The hypothesis was that air sealing the floor system that separated the foundation from the living space should better isolate the living space from the foundation; this isolation should lead to less radon entering the living space from the foundation. If the hypothesis had been proven, retrofit energy-efficiency programs may have chosen to adopt these isolation methods for enhanced radon protection to the living space.

  19. Hierarchical Boltzmann simulations and model error estimation

    Science.gov (United States)

    Torrilhon, Manuel; Sarna, Neeraj

    2017-08-01

    A hierarchical simulation approach for Boltzmann's equation should provide a single numerical framework in which a coarse representation can be used to compute gas flows as accurately and efficiently as in computational fluid dynamics, but a subsequent refinement allows to successively improve the result to the complete Boltzmann result. We use Hermite discretization, or moment equations, for the steady linearized Boltzmann equation for a proof-of-concept of such a framework. All representations of the hierarchy are rotationally invariant and the numerical method is formulated on fully unstructured triangular and quadrilateral meshes using a implicit discontinuous Galerkin formulation. We demonstrate the performance of the numerical method on model problems which in particular highlights the relevance of stability of boundary conditions on curved domains. The hierarchical nature of the method allows also to provide model error estimates by comparing subsequent representations. We present various model errors for a flow through a curved channel with obstacles.

  20. Fast Computation of Radon-Wigner Transform & Radon-Ambiguity Transform and its Application in SAR/GMTI%Radon-Wigner和Radon-Ambiguity快速算法及其在SAR/GMTI中的应用

    Institute of Scientific and Technical Information of China (English)

    盛蔚; 毛士艺

    2003-01-01

    本文针对Radon-Wigner Transform、Radon-Ambiguity Transform检测线性调频信号中的若干问题进行研究.Radon-Wigner Transform和Radon-Ambiguity Transform保留了Wigner-Ville分布和模糊函数时频聚集性高的优点,克服了它们在检测多分量信号时存在严重的交叉项问题.本文首先分析并证明了Wigner-Ville分布和模糊函数中交叉项与自主项的不同,指出该"不同"即是Radon-Wigner Transform和Radon-Ambiguity Transform能够抑制交叉项的根本原因;其次,本文证明了Radon-Wigner Transform的一种快速计算方法,并且以分数阶傅利叶变换为桥梁,给出了Radon-Ambiguity Transform的快速计算方法;最后,本文将Radon-Wigner Transform和Radon-Ambiguitiy Transform快速计算方法用于合成孔径雷达对地面运动目标的检测和参数估计中,取得了预期的较好的检测结果.

  1. Systematic effects in radon mitigation by sump/pump remediation

    Energy Technology Data Exchange (ETDEWEB)

    Groves-Kirkby, C.J.; Denman, A.R. [Northampton General Hospital, Medical Physics Dept. (United Kingdom); Groves-Kirkby, C.J.; Woolridge, A.C. [Northampton Univ., School of Health (United Kingdom); Woolridge, A.C.; Phillips, P.S.; Crockett, R.G.M. [Northampton Univ., School of Applied Sciences (United Kingdom); Tornberg, R. [Radon Centres Ltd., Grove Farm, Moulton, Northampton (United Kingdom)

    2006-07-01

    Sump/Pump remediation is widely used in the United Kingdom to mitigate indoor radon gas levels in residential properties. To quantify the effectiveness of this technology, a study was made of radon concentration data from a set of 173 homes situated in radon Affected Areas in and around Northamptonshire, U.K., re-mediated using conventional sump/pump tology. This approach is characterised by a high incidence of satisfactory mitigation outcomes, with more than 75% of the sample exhibiting mitigation factors (defined as the ratio of radon concentrations following and prior to remediation) of 0.2 or better. There is evidence of a systematic trend, where houses with higher initial radon concentrations have higher mitigation factors, suggesting that the total indoor radon concentration within a dwelling can be represented by two components, one susceptible to mitigation by sump/pump remediation, the other remaining essentially unaffected by these remediation strategies. The first component can be identified with ground-radon emanating from the subsoil and bedrock geologies, percolating through the foundations of the dwelling as a component of the soil-gas, potentially capable of being attenuated by sump/pump or radon-barrier remediation. The second contribution is attributed to radon emanating from materials used in the construction of the dwelling, principally concrete and gypsum plaster-board, with a further small contribution from the natural background level, and is essentially unaffected by ground-level remediation strategies. Modelling of such a two-component radon dependency using realistic ground-radon attenuation factors in conjunction with typical structural-radon levels yields behaviour in good agreement with the observed inverse-power dependence of mitigation factor on initial radon concentration. (authors)

  2. Soil gas radon mapping of Muzaffarabad city, Pakistan

    Directory of Open Access Journals (Sweden)

    Tareen Aleem Dad Khan

    2016-01-01

    Full Text Available Soil-based radon investigations are of value in correlating radon production and its transportation into buildings through the processes of convection and diffusion. Such studies can help in identifying land areas that pose special concerns. We present preliminary results of soil radon gas measurements at 60 different locations in an attempt to map out the geohazard zone of the city of Muzaffarabad. The seismic geohazard microzonation for the area includes five microzones based on different hazard parameters: a very high hazard zone, a high hazard zone, a moderate hazard zone, a low hazard zone, and a safe zone. Measurements were taken with an active radon monitoring system at the depths of 30, 40, 50, and 60 cm below the ground surface. The results obtained were explained by the lithology of the area. Average soil radon gas concentrations were correlated with the depth from the ground surface and indoor radon values for the study area. No significant correlation was found between soil radon gas and meteorological parameters, however soil radon gas increases as the depth from the surface of the ground grows. The results showed a linear relation between soil radon concentrations with depth from ground surface (R2 = 0.9577. The minimum soil radon concentration (68.5 Bq/m3 was found at a depth of 30 cm in the very high hazard zone, the maximum value (53.300 Bq/m3 at a depth of 60 cm in the seismically safe zone. Measured soil gas radon concentrations at depths of 30, 40, 50, and 60 cm were mapped for high, moderate, and low radon concentrations. Elevated soil radon gas concentrations were found in the safe zone, otherwise considered to be suitable for any type of construction.

  3. Discrete Wigner function dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Klimov, A B; Munoz, C [Departamento de Fisica, Universidad de Guadalajara, Revolucion 1500, 44410, Guadalajara, Jalisco (Mexico)

    2005-12-01

    We study the evolution of the discrete Wigner function for prime and the power of prime dimensions using the discrete version of the star-product operation. Exact and semiclassical dynamics in the limit of large dimensions are considered.

  4. Micromechanics of hierarchical materials

    DEFF Research Database (Denmark)

    Mishnaevsky, Leon, Jr.

    2012-01-01

    A short overview of micromechanical models of hierarchical materials (hybrid composites, biomaterials, fractal materials, etc.) is given. Several examples of the modeling of strength and damage in hierarchical materials are summarized, among them, 3D FE model of hybrid composites...... with nanoengineered matrix, fiber bundle model of UD composites with hierarchically clustered fibers and 3D multilevel model of wood considered as a gradient, cellular material with layered composite cell walls. The main areas of research in micromechanics of hierarchical materials are identified, among them......, the investigations of the effects of load redistribution between reinforcing elements at different scale levels, of the possibilities to control different material properties and to ensure synergy of strengthening effects at different scale levels and using the nanoreinforcement effects. The main future directions...

  5. Hierarchical auxetic mechanical metamaterials.

    Science.gov (United States)

    Gatt, Ruben; Mizzi, Luke; Azzopardi, Joseph I; Azzopardi, Keith M; Attard, Daphne; Casha, Aaron; Briffa, Joseph; Grima, Joseph N

    2015-02-11

    Auxetic mechanical metamaterials are engineered systems that exhibit the unusual macroscopic property of a negative Poisson's ratio due to sub-unit structure rather than chemical composition. Although their unique behaviour makes them superior to conventional materials in many practical applications, they are limited in availability. Here, we propose a new class of hierarchical auxetics based on the rotating rigid units mechanism. These systems retain the enhanced properties from having a negative Poisson's ratio with the added benefits of being a hierarchical system. Using simulations on typical hierarchical multi-level rotating squares, we show that, through design, one can control the extent of auxeticity, degree of aperture and size of the different pores in the system. This makes the system more versatile than similar non-hierarchical ones, making them promising candidates for industrial and biomedical applications, such as stents and skin grafts.

  6. Introduction into Hierarchical Matrices

    KAUST Repository

    Litvinenko, Alexander

    2013-12-05

    Hierarchical matrices allow us to reduce computational storage and cost from cubic to almost linear. This technique can be applied for solving PDEs, integral equations, matrix equations and approximation of large covariance and precision matrices.

  7. Hierarchical Auxetic Mechanical Metamaterials

    Science.gov (United States)

    Gatt, Ruben; Mizzi, Luke; Azzopardi, Joseph I.; Azzopardi, Keith M.; Attard, Daphne; Casha, Aaron; Briffa, Joseph; Grima, Joseph N.

    2015-02-01

    Auxetic mechanical metamaterials are engineered systems that exhibit the unusual macroscopic property of a negative Poisson's ratio due to sub-unit structure rather than chemical composition. Although their unique behaviour makes them superior to conventional materials in many practical applications, they are limited in availability. Here, we propose a new class of hierarchical auxetics based on the rotating rigid units mechanism. These systems retain the enhanced properties from having a negative Poisson's ratio with the added benefits of being a hierarchical system. Using simulations on typical hierarchical multi-level rotating squares, we show that, through design, one can control the extent of auxeticity, degree of aperture and size of the different pores in the system. This makes the system more versatile than similar non-hierarchical ones, making them promising candidates for industrial and biomedical applications, such as stents and skin grafts.

  8. Applied Bayesian Hierarchical Methods

    CERN Document Server

    Congdon, Peter D

    2010-01-01

    Bayesian methods facilitate the analysis of complex models and data structures. Emphasizing data applications, alternative modeling specifications, and computer implementation, this book provides a practical overview of methods for Bayesian analysis of hierarchical models.

  9. Programming with Hierarchical Maps

    DEFF Research Database (Denmark)

    Ørbæk, Peter

    This report desribes the hierarchical maps used as a central data structure in the Corundum framework. We describe its most prominent features, ague for its usefulness and briefly describe some of the software prototypes implemented using the technology....

  10. Catalysis with hierarchical zeolites

    DEFF Research Database (Denmark)

    Holm, Martin Spangsberg; Taarning, Esben; Egeblad, Kresten

    2011-01-01

    Hierarchical (or mesoporous) zeolites have attracted significant attention during the first decade of the 21st century, and so far this interest continues to increase. There have already been several reviews giving detailed accounts of the developments emphasizing different aspects of this research...... topic. Until now, the main reason for developing hierarchical zeolites has been to achieve heterogeneous catalysts with improved performance but this particular facet has not yet been reviewed in detail. Thus, the present paper summaries and categorizes the catalytic studies utilizing hierarchical...... zeolites that have been reported hitherto. Prototypical examples from some of the different categories of catalytic reactions that have been studied using hierarchical zeolite catalysts are highlighted. This clearly illustrates the different ways that improved performance can be achieved with this family...

  11. Mapping geogenic radon potential by regression kriging.

    Science.gov (United States)

    Pásztor, László; Szabó, Katalin Zsuzsanna; Szatmári, Gábor; Laborczi, Annamária; Horváth, Ákos

    2016-02-15

    Radon ((222)Rn) gas is produced in the radioactive decay chain of uranium ((238)U) which is an element that is naturally present in soils. Radon is transported mainly by diffusion and convection mechanisms through the soil depending mainly on the physical and meteorological parameters of the soil and can enter and accumulate in buildings. Health risks originating from indoor radon concentration can be attributed to natural factors and is characterized by geogenic radon potential (GRP). Identification of areas with high health risks require spatial modeling, that is, mapping of radon risk. In addition to geology and meteorology, physical soil properties play a significant role in the determination of GRP. In order to compile a reliable GRP map for a model area in Central-Hungary, spatial auxiliary information representing GRP forming environmental factors were taken into account to support the spatial inference of the locally measured GRP values. Since the number of measured sites was limited, efficient spatial prediction methodologies were searched for to construct a reliable map for a larger area. Regression kriging (RK) was applied for the interpolation using spatially exhaustive auxiliary data on soil, geology, topography, land use and climate. RK divides the spatial inference into two parts. Firstly, the deterministic component of the target variable is determined by a regression model. The residuals of the multiple linear regression analysis represent the spatially varying but dependent stochastic component, which are interpolated by kriging. The final map is the sum of the two component predictions. Overall accuracy of the map was tested by Leave-One-Out Cross-Validation. Furthermore the spatial reliability of the resultant map is also estimated by the calculation of the 90% prediction interval of the local prediction values. The applicability of the applied method as well as that of the map is discussed briefly. Copyright © 2015 Elsevier B.V. All rights

  12. Discrete Noether Currents

    CERN Document Server

    Seidl, Gerhart

    2014-01-01

    We present a simple generalization of Noether's theorem for discrete symmetries in relativistic continuum field theories. We calculate explicitly the conserved current for several discrete spacetime and internal symmetries. In addition, we formulate an analogue of the Ward-Takahashi identity for the Noether current associated with a discrete symmetry.

  13. Power Efficient Hierarchical Scheduling for DSP Transformations

    Directory of Open Access Journals (Sweden)

    P. K. Merakos

    2002-01-01

    Full Text Available In this paper, the problem of scheduling the computation of partial products in transformational Digital Signal Processing (DSP algorithms, aiming at the minimization of the switching activity in data and address buses, is addressed. The problem is stated as a hierarchical scheduling problem. Two different optimization algorithms, which are based on the Travelling Salesman Problem (TSP, are defined. The proposed optimization algorithms are independent on the target architecture and can be adapted to take into account it. Experimental results obtained from the application of the proposed algorithms in various widely used DSP transformations, like Discrete Cosine Transform (DCT and Discrete Fourier Transform (DFT, show that significant switching activity savings in data and address buses can be achieved, resulting in corresponding power savings. In addition, the differences between the two proposed methods are underlined, providing envisage for their suitable selection for implementation, in particular transformational algorithms and architectures.

  14. Mathematical model for radon diffusion in earthen materials

    Energy Technology Data Exchange (ETDEWEB)

    Nielson, K.K.; Rogers, V.C.

    1982-10-01

    Radon migration in porous, earthen materials is characterized by diffusion in both the air and water components of the system as well as by the interaction of the radon between the air and water. The size distribution and configuration of the pore spaces and their moisture distributions are key parameters in determining the radon diffusion coefficient for the bulk material. A mathematical model is developed and presented for calculating radon diffusion coefficients solely from the moisture content and pore size distribution of a soil, reducing the need for resorting to radon diffusion measurements. The resulting diffusion coefficients increase with the median pore diameter of the soil and decrease with increasing widths of the pore size distribution. The calculated diffusion coefficients are suitable for use in simple homogeneous-medium diffusion expressions for predicting radon transport and compare well with measured diffusion coefficients and with empirical diffusion coefficient correlations.

  15. Ambient Radon-222 Monitoring in Amargosa Valley, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    L.H. Karr; J.J. Tappen; D. Shafer; K.J. Gray

    2008-06-05

    As part of a program to characterize and baseline selected environmental parameters in the region around the proposed repository at Yucca Mountain, Nevada, ambient radon-222 monitoring was conducted in the rural community of Amargosa Valley, the community closest to the proposed repository site. Passive integrating radon monitors and a continuous radon monitoring instrument were deployed adjacent to the Community Environmental Monitoring Program (CEMP) (http://www.cemp.dri.edu/index.html) station located in the Amargosa Valley Community Center near the library. The CEMP station provided real-time ambient gamma exposure and meteorological data used to correct the integrated radon measurements as well as verify meteorological data collected by the continuous radon monitoring instrument. Additionally, different types of environmental enclosures that housed the monitors and instrument were used to determine if particular designs influenced the ambient radon measurements.

  16. A search profile for dwellings with elevated radon levels

    DEFF Research Database (Denmark)

    Damkjær, A.; Andersen, C.E.; Majborn, B.;

    1996-01-01

    basement/slab-on-grade foundation built on either fractured granitic basement rocks, or fractured limestone. Clayey till areas were also included in the profile in order to confirm earlier findings. Three areas representing these surface geologies were selected for indoor radon measurements with CR-39...... track detectors, and a total of 200 houses matching the profile underwent radon measurements during the winter 1994-95. The distribution of the measured radon concentrations were found in most cases to comply with log-normal distributions. Measurements in the living rooms of houses in each of the three......A search profile for dwellings with elevated radon levels has been employed to investigate possibly radon-prone areas in Denmark and to find houses suitable for radon mitigation studies. The profile is defined as dwellings which are single-family houses with slab-on-grade foundation or partly...

  17. Etched track radiometers in radon measurements: a review

    CERN Document Server

    Nikolaev, V A

    1999-01-01

    Passive radon radiometers, based on alpha particle etched track detectors, are very attractive for the assessment of radon exposure. The present review considers various devices used for measurement of the volume activity of radon isotopes and their daughters and determination of equilibrium coefficients. Such devices can be classified into 8 groups: (i) open or 'bare' detectors, (ii) open chambers, (iii) sup 2 sup 2 sup 2 Rn chambers with an inlet filter, (iv) advanced sup 2 sup 2 sup 2 Rn radiometers, (v) multipurpose radiometers, (vi) radiometers based on a combination of etched track detectors and an electrostatic field, (vii) radiometers based on etched track detectors and activated charcoal and (viii) devices for the measurement of radon isotopes and/or radon daughters by means of track parameter measurements. Some of them such as the open detector and the chamber with an inlet filter have a variety of modifications and are applied widely both in geophysical research and radon dosimetric surveys. At the...

  18. Design Criteria for Achieving Low Radon Concentration Indoors

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2016-01-01

    Design criteria for achieving low radon concentration indoors are presented in this paper. The paper suggests three design criteria. These criteria have to be considered at the early stage of the building design phase to meet the latest recommendations from the World Health Organization in most...... the radon concentration in the indoor air. In addition, a cheap and reliable method for measuring the radon concentration in the air indoors is described. The provision on radon in the Danish Building Regulations complies with the latest recommendations from the World Health Organization. Radon can cause...... lung cancer and it is not known whether there is a lower limit for when it is not harmful to human beings. Therefore, it is important to reduce the radon concentration as much as possible indoors in buildings. Airtightness is an important factor when dealing with buildings. For the building envelope...

  19. Radon Concentration in the Drinking Water of Aliabad Katoul, Iran

    Science.gov (United States)

    Adinehvand, Karim; Sahebnasagh, Amin; Hashemi-Tilehnoee, Mehdi

    2016-01-01

    Background According to the world health organization, radon is a leading cause of cancer in various internal organs and should be regarded with concern. Objectives The aim of this study is to evaluate the concentration of soluble radon in the drinking water of the city of Aliabad Katoul, Iran. Materials and Methods The radon concentration was measured by using a radon meter, SARADTM model RTM 1688-2, according to accepted standards of evaluation. Results The mean radon concentration in the drinking water of Aliabad Katoul is 2.90 ± 0.57 Bq/L. Conclusions The radon concentration in Aliabad Katoul is below the limit for hazardous levels, but some precautions will make conditions even safer for the local populace. PMID:27651948

  20. Improving the Teaching of Discrete-Event Control Systems Using a LEGO Manufacturing Prototype

    Science.gov (United States)

    Sanchez, A.; Bucio, J.

    2012-01-01

    This paper discusses the usefulness of employing LEGO as a teaching-learning aid in a post-graduate-level first course on the control of discrete-event systems (DESs). The final assignment of the course is presented, which asks students to design and implement a modular hierarchical discrete-event supervisor for the coordination layer of a…

  1. Radon Assessment of Occupational Facilities, Homestead ARB, FL

    Science.gov (United States)

    2013-11-21

    Consultative Letter 3. DATES COVERED (From – To) May 2013 – August 2013 4. TITLE AND SUBTITLE Radon Assessment of Occupational Facilities...unlimited. Case Number: 88ABW-2013-4919, 21 Nov 2013 13. SUPPLEMENTARY NOTES 14. ABSTRACT An assessment of indoor radon concentrations was...established in AFI 48-148 for long-term monitoring. Historical results indicate a radon risk characterization category of “medium,” requiring all

  2. Radon Emission from Coal Mines of Kuzbass Region

    Science.gov (United States)

    Portola, V. A.; Torosyan, E. S.; Antufeyev, V. K.

    2016-04-01

    The article represents the results of a research in radionuclides concentration in coal and rocks of Kuzbass mines as well as radon concentration in operative mines and mined-out spaces. It is proved that radon concentration in mines is considerably higher than in the atmosphere and it rises drastically in the mined-out spaces. It is found out that radon is carried out from mines by ventilation flows and from open pits, generating anomalous concentrations over self-ignition areas.

  3. Mapping geogenic radon potential by regression kriging

    Energy Technology Data Exchange (ETDEWEB)

    Pásztor, László [Institute for Soil Sciences and Agricultural Chemistry, Centre for Agricultural Research, Hungarian Academy of Sciences, Department of Environmental Informatics, Herman Ottó út 15, 1022 Budapest (Hungary); Szabó, Katalin Zsuzsanna, E-mail: sz_k_zs@yahoo.de [Department of Chemistry, Institute of Environmental Science, Szent István University, Páter Károly u. 1, Gödöllő 2100 (Hungary); Szatmári, Gábor; Laborczi, Annamária [Institute for Soil Sciences and Agricultural Chemistry, Centre for Agricultural Research, Hungarian Academy of Sciences, Department of Environmental Informatics, Herman Ottó út 15, 1022 Budapest (Hungary); Horváth, Ákos [Department of Atomic Physics, Eötvös University, Pázmány Péter sétány 1/A, 1117 Budapest (Hungary)

    2016-02-15

    Radon ({sup 222}Rn) gas is produced in the radioactive decay chain of uranium ({sup 238}U) which is an element that is naturally present in soils. Radon is transported mainly by diffusion and convection mechanisms through the soil depending mainly on the physical and meteorological parameters of the soil and can enter and accumulate in buildings. Health risks originating from indoor radon concentration can be attributed to natural factors and is characterized by geogenic radon potential (GRP). Identification of areas with high health risks require spatial modeling, that is, mapping of radon risk. In addition to geology and meteorology, physical soil properties play a significant role in the determination of GRP. In order to compile a reliable GRP map for a model area in Central-Hungary, spatial auxiliary information representing GRP forming environmental factors were taken into account to support the spatial inference of the locally measured GRP values. Since the number of measured sites was limited, efficient spatial prediction methodologies were searched for to construct a reliable map for a larger area. Regression kriging (RK) was applied for the interpolation using spatially exhaustive auxiliary data on soil, geology, topography, land use and climate. RK divides the spatial inference into two parts. Firstly, the deterministic component of the target variable is determined by a regression model. The residuals of the multiple linear regression analysis represent the spatially varying but dependent stochastic component, which are interpolated by kriging. The final map is the sum of the two component predictions. Overall accuracy of the map was tested by Leave-One-Out Cross-Validation. Furthermore the spatial reliability of the resultant map is also estimated by the calculation of the 90% prediction interval of the local prediction values. The applicability of the applied method as well as that of the map is discussed briefly. - Highlights: • A new method

  4. Correction factors for determination of annual average radon concentration in dwellings of Poland resulting from seasonal variability of indoor radon

    Energy Technology Data Exchange (ETDEWEB)

    Kozak, K., E-mail: Krzysztof.Kozak@ifj.edu.pl [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Krakow (Poland); Mazur, J. [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Krakow (Poland); KozLowska, B. [University of Silesia, Bankowa 12, 40-007 Katowice (Poland); Karpinska, M. [Medical University of Bialystok, Jana Kilinskiego 1, 15-089 BiaLystok (Poland); Przylibski, T.A. [WrocLaw University of Technology, Wybrzeze S. Wyspianskiego 27, 50-370 WrocLaw (Poland); Mamont-Ciesla, K. [Central Laboratory for Radiological Protection, Konwaliowa 7, 03-194 Warszawa (Poland); Grzadziel, D. [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Krakow (Poland); Stawarz, O. [Central Laboratory for Radiological Protection, Konwaliowa 7, 03-194 Warszawa (Poland); Wysocka, M. [Central Mining Institute, Plac Gwarkow1, 40-166 Katowice (Poland); Dorda, J. [University of Silesia, Bankowa 12, 40-007 Katowice (Poland); Zebrowski, A. [WrocLaw University of Technology, Wybrzeze S. Wyspianskiego 27, 50-370 WrocLaw (Poland); Olszewski, J. [Nofer Institute of Occupational Medicine, Sw.Teresy od Dzieciatka Jezus 8, 91-348 lodz (Poland); Hovhannisyan, H. [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Krakow (Poland); Dohojda, M. [Institute of Building Technology (ITB), Filtrowa 1, 00-611 Warszawa (Poland); KapaLa, J. [Medical University of Bialystok, Jana Kilinskiego 1, 15-089 BiaLystok (Poland); Chmielewska, I. [Central Mining Institute, Plac Gwarkow1, 40-166 Katowice (Poland); KLos, B. [University of Silesia, Bankowa 12, 40-007 Katowice (Poland); Jankowski, J. [Nofer Institute of Occupational Medicine, Sw.Teresy od Dzieciatka Jezus 8, 91-348 lodz (Poland); Mnich, S. [Medical University of Bialystok, Jana Kilinskiego 1, 15-089 BiaLystok (Poland); KoLodziej, R. [Central Mining Institute, Plac Gwarkow1, 40-166 Katowice (Poland)

    2011-10-15

    The method for the calculation of correction factors is presented, which can be used for the assessment of the mean annual radon concentration on the basis of 1-month or 3-month indoor measurements. Annual radon concentration is an essential value for the determination of the annual dose due to radon inhalation. The measurements have been carried out in 132 houses in Poland over a period of one year. The passive method of track detectors with CR-39 foil was applied. Four thermal-precipitation regions in Poland were established and correction factors were calculated for each region, separately for houses with and without basements. - Highlights: > Using radon concentration results in houses we calculated the correction factors. > Factors were calculated for each month, 2 house types in different regions in Poland. > They enable the evaluation of average annual radon concentration in the house. > Annual average radon concentration basing on 1 or 3 months detector exposure.

  5. A theoretical investigation of the distribution of indoor radon concentrations

    Science.gov (United States)

    Rabi, R.; Oufni, L.

    2017-05-01

    Inhalation of radon (222Rn) and its decay products are a major source of natural radiation exposure. It is known from recent surveys in many countries that radon and its progeny contribute significantly to total inhalation dose and it is fairly established that radon when inhaled in large quantity causes lung disorder. In recent times, numerical modelling has become the cost effective replacement of experimental methods for the prediction and visualization of indoor pollutant distribution. The aim of this study is to implement the Finite Volume Method (FVM) for studying the radon distribution indoor. The findings show that the radon concentration which is distributed in a non-homogeneous way in the room is due to the difference in the radon concentration of different sources (wall, floor and ceiling). Moreover, the radon concentration is much larger near walls, and decreases in the middle of the room because of the effect of air velocity. We notice that the simulation results of radon concentration are in agreement with the results of other experimental studies. The annual effective dose of radon in the model room has been also investigated.

  6. Estimation of radon concentration in dwellings in and around Guwahati

    Science.gov (United States)

    Dey, Gautam Kumar; Das, Projit Kumar

    2012-02-01

    It has been established that radon and its airborne decay products can present serious radiation hazards. A long term exposure to high concentration of radon causes lung cancer. Besides, it is also known that out of the total radiation dose received from natural and man-made sources, 60% of the dose is due to radon and its progeny. Taking this into account, an attempt has been made to estimate radon concentration in dwellings in and around Guwahati using aluminium dosimeter cups with CR-39 plastic detectors. Results of preliminary investigation presented in this paper show that the mean concentration is 21.31 Bq m - 3.

  7. Radon exhalation from building materials used in Libya

    Science.gov (United States)

    Saad, A. F.; Al-Awami, Hend H.; Hussein, N. A.

    2014-08-01

    Radon exhalation rates have been determined for various different samples of domestic and imported building materials available in the Libyan market for home construction and interior decoration. Radon exhalation rates were measured by the sealed-can technique based on CR-39 nuclear track detectors (NTDs). The results show that radon exhalation rates from some imported building materials used as foundations and for decoration are extremely high, and these samples are the main sources of indoor radon emanation. Radium contents and annual effective doses have also been estimated.

  8. Estimation of radon concentration in dwellings in and around Guwahati

    Indian Academy of Sciences (India)

    Gautam Kumar Dey; Projit Kumar Das

    2012-02-01

    It has been established that radon and its airborne decay products can present serious radiation hazards. A long term exposure to high concentration of radon causes lung cancer. Besides, it is also known that out of the total radiation dose received from natural and man-made sources, 60% of the dose is due to radon and its progeny. Taking this into account, an attempt has been made to estimate radon concentration in dwellings in and around Guwahati using aluminium dosimeter cups with CR-39 plastic detectors. Results of preliminary investigation presented in this paper show that the mean concentration is 21.31 Bq m−3.

  9. Soil gas and indoor radon studies in Doon Valley, India

    Energy Technology Data Exchange (ETDEWEB)

    Choubey, V.M.; Sharma, K.K. (Wadia Inst. of Himalayan Geology, Dehra Dun (India)); Ramola, R.C. (Garhwal University, Tehri Garhwal (India). Dept. of Physics)

    1994-02-01

    Radon studies have been carried out in the soil and in dwellings around the Doon Valley, north-west India, using Kodak LR-115 Type II plastic track detectors. Soil gas radon concentrations were found to be higher in carbonaceous shales of the Infra-Krol and in the sandstone of the middle Siwaliks. High values of radon were also observed along prominent tectonic zones, such as the Main Boundary Thrust and the Main Frontal Thrust. In dwellings, the radon values were found to depend on the geology of the area, on the building materials and on the type and construction of the houses. (Author).

  10. Assessment of Radon level in dwellings of Tabriz

    Directory of Open Access Journals (Sweden)

    Gholamhassan Haddadi

    2011-06-01

    Full Text Available Background & Objective: Indoor radon gas (222Rn has been recognized as one of the causes of lung cancer. The presence of radioactive radium in the construction & materials in the buildings its changes in contact with radon gas may lead to increase level of radon gas in the residential houses. In this regards, indoor radon measurement is important. This study was conducted to determine radon concentration in Tabriz houses. Materials & Methods: In this study, 196 radon diffusion dosimeters were left in different floors of houses constructed with different materials such as cement (betony, heated brick & clay with raw brick at every floor for 6 months. The “electrochemical etching” method was applied to detect “alpha tracks” on the polymers of dosimeters and based on number of these tracks, radon concentration was determined. Results: This study showed that average radon concentration were 39Bqm-3 in the houses. At different floors & different construction material the average effective dose equivalent of lung tissue was 0.97msvy-1. Conclusion: Based on these results, it can be concluded that, the indoor radon levels in the Tabriz houses are within acceptable range.

  11. Radon exhalation from building materials for decorative use.

    Science.gov (United States)

    Chen, Jing; Rahman, Naureen M; Abu Atiya, Ibrahim

    2010-04-01

    Long-term exposure to radon increases the risk of developing lung cancer. There is considerable public concern about radon exhalation from building materials and the contribution to indoor radon levels. To address this concern, radon exhalation rates were determined for 53 different samples of drywall, tile and granite available on the Canadian market for interior home decoration. The radon exhalation rates ranged from non-detectable to 312 Bq m(-2) d(-1). Slate tiles and granite slabs had relatively higher radon exhalation rates than other decorative materials, such as ceramic or porcelain tiles. The average radon exhalation rates were 30 Bq m(-2) d(-1) for slate tiles and 42 Bq m(-2) d(-1) for granite slabs of various types and origins. Analysis showed that even if an entire floor was covered with a material having a radon exhalation rate of 300 Bq m(-2) d(-1), it would contribute only 18 Bq m(-3) to a tightly sealed house with an air exchange rate of 0.3 per hour. Generally speaking, building materials used in home decoration make no significant contribution to indoor radon for a house with adequate air exchange.

  12. Nonlinear Radon Transform Using Zernike Moment for Shape Analysis

    Directory of Open Access Journals (Sweden)

    Ziping Ma

    2013-01-01

    Full Text Available We extend the linear Radon transform to a nonlinear space and propose a method by applying the nonlinear Radon transform to Zernike moments to extract shape descriptors. These descriptors are obtained by computing Zernike moment on the radial and angular coordinates of the pattern image's nonlinear Radon matrix. Theoretical and experimental results validate the effectiveness and the robustness of the method. The experimental results show the performance of the proposed method in the case of nonlinear space equals or outperforms that in the case of linear Radon.

  13. Current international intercomparison measurement on radon and its progeny

    Energy Technology Data Exchange (ETDEWEB)

    Yamasaki, Keizo [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.

    1996-12-01

    The international intercomparison measurement on radon and its progeny was held between the EML of USDOE and several Japanese organisations, using the radon test chamber installed in EML. Japanese results of radon concentration by the active method using the ionization chamber or scintillation cell and the passive method using the solid track detector were about 5% small compared to that of EML. On the results of radon progeny, there were not any large systematic differences between EML and Japanese participants in spite of wide range of deviation except for the results at the condition of low aerosol density. (author)

  14. Radon exhalation rates from some soil samples of Kharar, Punjab

    Energy Technology Data Exchange (ETDEWEB)

    Mehta, Vimal [Deptt of Physics, M. M. University, Mullana (Ambala)-133 207 (India); Deptt of Physics, Punjabi University, Patiala- 147 001 (India); Singh, Tejinder Pal, E-mail: tejinders03@gmail.com [Deptt of Physics, S.A. Jain (P.G.) College, Ambala City- 134 003 (India); Chauhan, R. P. [Deptt of Physics, National Institute of Technology, Kurukshetra- 136 119 (India); Mudahar, G. S. [Deptt of Physics, Punjabi University, Patiala- 147 001 (India)

    2015-08-28

    Radon and its progeny are major contributors in the radiation dose received by general population of the world. Because radon is a noble gas, a large portion of it is free to migrate away from radium. The primary sources of radon in the houses are soils and rocks source emanations, emanation from building materials, and entry of radon into a structure from outdoor air. Keeping this in mind the study of radon exhalation rate from some soil samples of the Kharar, Punjab has been carried out using Can Technique. The equilibrium radon concentration in various soil samples of Kharar area of district Mohali varied from 12.7 Bqm{sup −3} to 82.9 Bqm{sup −3} with an average of 37.5 ± 27.0 Bqm{sup −3}. The radon mass exhalation rates from the soil samples varied from 0.45 to 2.9 mBq/kg/h with an average of 1.4 ± 0.9 mBq/kg/h and radon surface exhalation rates varied from 10.4 to 67.2 mBq/m{sup 2}/h with an average of 30.6 ± 21.8 mBq/m{sup 2}/h. The radon mass and surface exhalation rates of the soil samples of Kharar, Punjab were lower than that of the world wide average.

  15. Strategy for the reduction of radon exposure in Norway

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-05-15

    Elevated indoor radon concentrations are a more extensive problem in Norway than in many other countries. It has been estimated that indoor radon causes approximately 300 deaths from lung cancer each year in Norway. On average, avoiding lung cancer increases life expectancy by 14 to 18 years. Radon is a radioactive noble gas formed continually is a decay product from uranium. Uranium is a natural constituent existing in varying concentrations in bedrock, minerals and soils. For this reason, both the soil air and groundwater contain radon. Radon in buildings normally originates from the soil air in the underlying ground. Indoor air pressure is often low, so that radon-containing air from the surrounding ground gets sucked in through cracks in the building foundations. Elevated indoor radon concentrations can be due to household water drawn from groundwater wells, and radon gas can also be emitted from building materials such as certain types of stone or concrete containing high levels of natural radioactivity. Norway, Sweden and Finland are among the the countries in the world with the highest average indoor radon concentrations. Geological conditions and the cool climate pose a big challenge, but the radon problem can be solved in a cost-effective way. Radon is the most common cause of lung cancer after active smoking. At a radon concentration of 100 Bq/m3, which is not far from the estimated average for Norwegian housing, the risks of dying of radon-induced lung cancer before the age of 75 are 0.1 % for non-smokers and 2 % for smokers, respectively. Many buildings in Norway have radon levels that exceed this. The most important health impact of radon exposure is the increased risk of lung cancer. This increase in risk is assumed to be linear in relation to radon concentration (i.e., the risk is 10 times higher at 1000 Bq/m3 compared to 100 Bq/m3). The risk also increases linearly with exposure time, i.e. there is a tenfold greater risk of contracting lung cancer

  16. Strategy for the reduction of radon exposure in Norway

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-05-15

    Elevated indoor radon concentrations are a more extensive problem in Norway than in many other countries. It has been estimated that indoor radon causes approximately 300 deaths from lung cancer each year in Norway. On average, avoiding lung cancer increases life expectancy by 14 to 18 years. Radon is a radioactive noble gas formed continually is a decay product from uranium. Uranium is a natural constituent existing in varying concentrations in bedrock, minerals and soils. For this reason, both the soil air and groundwater contain radon. Radon in buildings normally originates from the soil air in the underlying ground. Indoor air pressure is often low, so that radon-containing air from the surrounding ground gets sucked in through cracks in the building foundations. Elevated indoor radon concentrations can be due to household water drawn from groundwater wells, and radon gas can also be emitted from building materials such as certain types of stone or concrete containing high levels of natural radioactivity. Norway, Sweden and Finland are among the the countries in the world with the highest average indoor radon concentrations. Geological conditions and the cool climate pose a big challenge, but the radon problem can be solved in a cost-effective way. Radon is the most common cause of lung cancer after active smoking. At a radon concentration of 100 Bq/m3, which is not far from the estimated average for Norwegian housing, the risks of dying of radon-induced lung cancer before the age of 75 are 0.1 % for non-smokers and 2 % for smokers, respectively. Many buildings in Norway have radon levels that exceed this. The most important health impact of radon exposure is the increased risk of lung cancer. This increase in risk is assumed to be linear in relation to radon concentration (i.e., the risk is 10 times higher at 1000 Bq/m3 compared to 100 Bq/m3). The risk also increases linearly with exposure time, i.e. there is a tenfold greater risk of contracting lung cancer

  17. Parallel hierarchical radiosity rendering

    Energy Technology Data Exchange (ETDEWEB)

    Carter, M.

    1993-07-01

    In this dissertation, the step-by-step development of a scalable parallel hierarchical radiosity renderer is documented. First, a new look is taken at the traditional radiosity equation, and a new form is presented in which the matrix of linear system coefficients is transformed into a symmetric matrix, thereby simplifying the problem and enabling a new solution technique to be applied. Next, the state-of-the-art hierarchical radiosity methods are examined for their suitability to parallel implementation, and scalability. Significant enhancements are also discovered which both improve their theoretical foundations and improve the images they generate. The resultant hierarchical radiosity algorithm is then examined for sources of parallelism, and for an architectural mapping. Several architectural mappings are discussed. A few key algorithmic changes are suggested during the process of making the algorithm parallel. Next, the performance, efficiency, and scalability of the algorithm are analyzed. The dissertation closes with a discussion of several ideas which have the potential to further enhance the hierarchical radiosity method, or provide an entirely new forum for the application of hierarchical methods.

  18. Fractured reservoir discrete feature network technologies. Final report, March 7, 1996 to September 30, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Dershowitz, William S.; Einstein, Herbert H.; LaPoint, Paul R.; Eiben, Thorsten; Wadleigh, Eugene; Ivanova, Violeta

    1998-12-01

    This report summarizes research conducted for the Fractured Reservoir Discrete Feature Network Technologies Project. The five areas studied are development of hierarchical fracture models; fractured reservoir compartmentalization, block size, and tributary volume analysis; development and demonstration of fractured reservoir discrete feature data analysis tools; development of tools for data integration and reservoir simulation through application of discrete feature network technologies for tertiary oil production; quantitative evaluation of the economic value of this analysis approach.

  19. Design, construction and testing of a radon experimental chamber; Diseno, construccion y pruebas de una camara experimental de radon

    Energy Technology Data Exchange (ETDEWEB)

    Chavez B, A.; Balcazar G, M

    1991-10-15

    To carry out studies on the radon behavior under controlled and stable conditions it was designed and constructed a system that consists of two parts: a container of mineral rich in Uranium and an experimentation chamber with radon united one to the other one by a step valve. The container of uranium mineral approximately contains 800 gr of uranium with a law of 0.28%; the radon gas emanated by the mineral is contained tightly by the container. When the valve opens up the radon gas it spreads to the radon experimental chamber; this contains 3 accesses that allow to install different types of detectors. The versatility of the system is exemplified with two experiments: 1. With the radon experimental chamber and an associated spectroscopic system, the radon and two of its decay products are identified. 2. The design of the system allows to couple the mineral container to other experimental geometries to demonstrate this fact it was coupled and proved a new automatic exchanger system of passive detectors of radon. The results of the new automatic exchanger system when it leave to flow the radon freely among the container and the automatic exchanger through a plastic membrane of 15 m. are shown. (Author)

  20. Behavior of radon and its decay products in physical media; Comportamiento de radon y sus productos en medios fisicos

    Energy Technology Data Exchange (ETDEWEB)

    Chavez B, A

    1990-06-15

    This study was carried out to know the radon behavior, it shows some of its decay products of short life, the same as the equations that describe the growth of the activity of each decay product in a source that initially is radon. The study threw results that they are applicable in geology, uranium prospecting, as well as in radiological safety. The use of membranes to filter the decay products of radon and the use of these for protection of the detector, it has opened a new line in the study of the radon. (Author)

  1. Monitoring of radon in water of Taiwan

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yu-Ming; Chen, Chin-Chiang (Taiwan Radiation Monitoring Station, Atomic Energy Council of Executive Yuan, Kaohsiung Hsien (Republic of China))

    1983-03-01

    The toluene extraction-liquid scintillation counting method was used to measure the radon concentration in water samples of Taiwan, R.O.C. The experimental results showed that the counting efficiency for both ..cap alpha.. and ..beta.. emitted from radon and its daughters could reach 100%. The separation of activity of /sup 222/Rn from /sup 220/Rn was performed according to Bunny method. Thirty sampling stations including water samples from wells and hot springs throughout Taiwan were analyzed. The measured data show that /sup 220/Rn has much higher concentration than /sup 222/Rn. The concentration for the former is in the order of 10/sup -7/ Ci/l while that for the later is about 10/sup -10/ Ci/l.

  2. Radon in soil concentration levels in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Segovia, N.; Tamez, E.; Mena, M

    1991-09-15

    Radon in soil surveys in Mexico have been carried out since 1974 both for uranium prospectus and to correlate mean values of the gas emanation with local telluric behaviour. The mapping includes the northern uranium mining region, the Mexican Neo volcanic Belt, the coastal areas adjacent to the zone of subduction of the Cocos Plate under the North American Plate, some of the active volcanoes of Southern Mexico and several sedimentary valleys in Central Mexico. Recording of {sup 222} Rn alpha decay is systematically performed with LR115 track detectors. Using mean values averaged over different observation periods at fixed monitoring stations, a radon in soil map covering one third of the Mexican territory is presented. The lowest mean values have been found in areas associated with active volcanoes. The highest levels are found in uranium ore zones. Intermediate values are obtained in regions with enhanced hydrothermal activity and stations associated with intrusive rocks. (Author)

  3. A study of radon indoor concentration; Un estudio de concentracion de radon intramuros

    Energy Technology Data Exchange (ETDEWEB)

    Pena, P.; Ruiz, W.; Segovia, N.; Ponciano, G. [ININ, Gerencia de Ciencias Ambientales, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    It was realized a study of radon concentration in houses of Mexico City and in a laboratory of the Nuclear Centre of Salazar, State of Mexico. The radon determination in air was realized with solid nuclear track detectors and with Honeywell and Alpha guard automatic equipment. The results show that the majority of houses have values under 148 Bq/m{sup 3} obtaining some housings with upper values located in the Lomas zone. A study in smokers houses and another of controls showed very similar distributions. It was studied the day time fluctuations finding that radon increases considerably during the dawn. Some upper values obtained in a laboratory of the Nuclear Centre were remedied with ventilation. (Author)

  4. Neutrosophic Hierarchical Clustering Algoritms

    Directory of Open Access Journals (Sweden)

    Rıdvan Şahin

    2014-03-01

    Full Text Available Interval neutrosophic set (INS is a generalization of interval valued intuitionistic fuzzy set (IVIFS, whose the membership and non-membership values of elements consist of fuzzy range, while single valued neutrosophic set (SVNS is regarded as extension of intuitionistic fuzzy set (IFS. In this paper, we extend the hierarchical clustering techniques proposed for IFSs and IVIFSs to SVNSs and INSs respectively. Based on the traditional hierarchical clustering procedure, the single valued neutrosophic aggregation operator, and the basic distance measures between SVNSs, we define a single valued neutrosophic hierarchical clustering algorithm for clustering SVNSs. Then we extend the algorithm to classify an interval neutrosophic data. Finally, we present some numerical examples in order to show the effectiveness and availability of the developed clustering algorithms.

  5. Estimation of human dose to radon progeny

    Energy Technology Data Exchange (ETDEWEB)

    Shimo, Michikuni [Gifu Coll. of Medical Technology, Sekiichi, Gifu (Japan)

    1996-12-01

    The aim of the paper is the estimation of the effective dose due to radon progeny for Japanese population. The estimation was performed by a modified UNSCEAR equation. The equation was needed the radon concentration annual occupancy time and the tidal volume on Japanese people and the dose conversion coefficient are needed. Furthermore, not only these figures but also unattached fraction and aerosol distribution data obtained in Japan and the factor related to the Japanese living style were used in the calculation. We used following figures as representative value in Japan; radon concentration: 13(6 - 25) Bq/m{sup 3} indoors and 6.7(3.5 - 13) Bq/m{sup 3} outdoors; the equilibrium factor: 0.45(0.35 - 0.57) indoors and 0.70(0.50 - 0.90) outdoors; the occupancy factor: 0.87 indoors, 0.09 outdoors and 0.04 in vehicle for male and 0.91 indoors, 0.06 outdoors and 0.03 in vehicle for female; the tidal volume: 7,000 (4,000 - 8,000) m{sup 3} for male, 6,200 (3,500 - 7,500) m{sup 3} for female. The effective doses due to radon progeny were estimated to be 0.45 mSv/y for male and 0.40 mSv/y for female, and the variance was -80 - +130%. These values were 1/2 - 1/3 as small as values shown by UNSCEAR 1993 Report and estimated by ICRP Publication 65. (author)

  6. Environmental radon with RAD7 detector; Radon ambiental con detector RAD7

    Energy Technology Data Exchange (ETDEWEB)

    Lopez M, A.; Balcazar, M. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Fernandez G, I. M.; Capote F, E., E-mail: arturo.lopez@inin.gob.mx [Centro de Proteccion e Higiene de las Radiaciones, Carretera La Victoria II Km 2.5 e/ Monumental y Final, Guanabacoa, La Habana (Cuba)

    2016-09-15

    Experimental results of the radon detection with the equipment RAD7 are presented. The use of a solid state detector placed in a semi-spherical chamber with an electric field allows a high sensitivity of 0.4 cpm/P Ci/l. Radon detection is achieved by the spectroscopy of its decay products. In accordance with a table of errors for various ranges of counts and radon concentrations, reported by the manufacturer, an equation was obtained that allows establishing operation criteria of the equipment. For radon detection at ambient concentrations as low as 30 Bq m{sup -3}, is shown that short counts of 10 minutes are good enough to make decisions on radiation protection matter. In places where concentrations are close to 200 Bq m{sup -3}, counting intervals of the order of 0.5 hours will have an acceptable counting error of the order of 20%. The determination of radon in soil was, according to the expected, on the order of 10 kBq m{sup -3}, and was found that even with the recommended counting times of 5 minutes, there is a risk of increased humidity inside the detector above 20% Rh, with associated reduction of detection efficiency, if the desiccant is not used properly. The equipment was subjected to a radon exposure in air of 13, 373 Bq m{sup -3} ± 3.7%, contained within a controlled chamber, with a variation in temperature of (19-21) degrees Celsius and in the relative humidity of (5-7) %, the good stability of the chamber allows to propose calibration processes of these equipment s by assessing the concentration by means of a Ge (Hp) detector. (Author)

  7. Sex and smoking sensitive model of radon induced lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zhukovsky, M.; Yarmoshenko, I. [Institute of Industrial Ecology of Ural Branch of Russian Academy of Sciences, Yekaterinburg (Russian Federation)

    2006-07-01

    Radon and radon progeny inhalation exposure are recognized to cause lung cancer. Only strong evidence of radon exposure health effects was results of epidemiological studies among underground miners. Any single epidemiological study among population failed to find reliable lung cancer risk due to indoor radon exposure. Indoor radon induced lung cancer risk models were developed exclusively basing on extrapolation of miners data. Meta analyses of indoor radon and lung cancer case control studies allowed only little improvements in approaches to radon induced lung cancer risk projections. Valuable data on characteristics of indoor radon health effects could be obtained after systematic analysis of pooled data from single residential radon studies. Two such analyses are recently published. Available new and previous data of epidemiological studies of workers and general population exposed to radon and other sources of ionizing radiation allow filling gaps in knowledge of lung cancer association with indoor radon exposure. The model of lung cancer induced by indoor radon exposure is suggested. The key point of this model is the assumption that excess relative risk depends on both sex and smoking habits of individual. This assumption based on data on occupational exposure by radon and plutonium and also on the data on external radiation exposure in Hiroshima and Nagasaki and the data on external exposure in Mayak nuclear facility. For non-corrected data of pooled European and North American studies the increased sensitivity of females to radon exposure is observed. The mean value of ks for non-corrected data obtained from independent source is in very good agreement with the L.S.S. study and Mayak plutonium workers data. Analysis of corrected data of pooled studies showed little influence of sex on E.R.R. value. The most probable cause of such effect is the change of men/women and smokers/nonsmokers ratios in corrected data sets in North American study. More correct

  8. Radon release and dispersion from an open pit uranium mine

    Energy Technology Data Exchange (ETDEWEB)

    Kisieleski, W.E.

    1980-06-01

    Radon-222 flux from representative sections of the United Nuclear St. Anthony open-pit mine complex was measured. The collected radon was adsorbed on activated charcoal and the radon activity was measured by gamma spectroscopy. System design, calibration, and the procedure to determine radon flux density (pCi/m/sup 2/.s) are described. A continuous series of radon flux densities were measured over a 5-month period at a control point in the mine. The average flux density at the control point was 1.9 pCi/m/sup 2/.s. A close correlation between radon flux density variations and changes in barometric pressure was observed by a comparison of meteorological data and average daily radon flux density measured at the control point. The release rate from each section of the mine was calculated from the average radon flux density and the area of the section, as determined from enlarged aerial photographs. The average radon flux density for eight locations over the ore-bearing section was 7.3 pCi/m/sup 2/.s. The average flux density for four locations over undisturbed topsoil was 0.17 pCi/m/sup 2/.s. The average Ra-226 content of ten samples taken from the ore-bearing region was 102 pCi/g ore. The ratio of radon flux density to radium content (specific flux) was 0.072. The release rate from the entire St. Anthony open pit was determined to be 3.5 x 10/sup 5/ pCi/s. This rate is comparable to the natural release of radon from one square mile of undisturbed topsoil. 16 refs., 31 figs., 11 tabs.

  9. Statistical discrete geometry

    CERN Document Server

    Ariwahjoedi, Seramika; Kosasih, Jusak Sali; Rovelli, Carlo; Zen, Freddy Permana

    2016-01-01

    Following our earlier work, we construct statistical discrete geometry by applying statistical mechanics to discrete (Regge) gravity. We propose a coarse-graining method for discrete geometry under the assumptions of atomism and background independence. To maintain these assumptions, restrictions are given to the theory by introducing cut-offs, both in ultraviolet and infrared regime. Having a well-defined statistical picture of discrete Regge geometry, we take the infinite degrees of freedom (large n) limit. We argue that the correct limit consistent with the restrictions and the background independence concept is not the continuum limit of statistical mechanics, but the thermodynamical limit.

  10. A COMPARISON OF WINTER SHORT-TERM AND ANNUAL AVERAGE RADON MEASUREMENTS IN BASEMENTS OF A RADON-PRONE REGION AND EVALUATION OF FURTHER RADON TESTING INDICATORS

    Science.gov (United States)

    Barros, Nirmalla G.; Steck, Daniel J.; Field, R. William

    2014-01-01

    The primary objective of this study was to investigate the temporal variability between basement winter short-term (7 to 10 days) and basement annual radon measurements. Other objectives were to test the short-term measurement’s diagnostic performance at two reference levels and to evaluate its ability to predict annual average basement radon concentrations. Electret ion chamber (short-term) and alpha track (annual) radon measurements were obtained by trained personnel in Iowa residences. Overall, the geometric mean of the short-term radon concentrations (199 Bq m−3) was slightly greater than the geometric mean of the annual radon concentrations (181 Bq m−3). Short-term tests incorrectly predicted that the basement annual radon concentrations would be below 148 Bq m−3 12% of the time and 2% of the time at 74 Bq m−3. The short-term and annual radon concentrations were strongly correlated (r=0.87, pradon potential when the reference level is lowered to 74 Bq m−3. PMID:24670901

  11. Anisotropic and Hierarchical Porosity in Multifunctional Ceramics

    Science.gov (United States)

    Lichtner, Aaron Zev

    The performance of multifunctional porous ceramics is often hindered by the seemingly contradictory effects of porosity on both mechanical and non-structural properties and yet a sufficient body of knowledge linking microstructure to these properties does not exist. Using a combination of tailored anisotropic and hierarchical materials, these disparate effects may be reconciled. In this project, a systematic investigation of the processing, characterization and properties of anisotropic and isotropic hierarchically porous ceramics was conducted. The system chosen was a composite ceramic intended as the cathode for a solid oxide fuel cell (SOFC). Comprehensive processing investigations led to the development of approaches to make hierarchical, anisotropic porous microstructures using directional freeze-casting of well dispersed slurries. The effect of all the important processing parameters was investigated. This resulted in an ability to tailor and control the important microstructural features including the scale of the microstructure, the macropore size and total porosity. Comparable isotropic porous ceramics were also processed using fugitive pore formers. A suite of characterization techniques including x-ray tomography and 3-D sectional scanning electron micrographs (FIB-SEM) was used to characterize and quantify the green and partially sintered microstructures. The effect of sintering temperature on the microstructure was quantified and discrete element simulations (DEM) were used to explain the experimental observations. Finally, the comprehensive mechanical properties, at room temperature, were investigated, experimentally and using DEM, for the different microstructures.

  12. Discrete mathematics, discrete physics and numerical methods

    OpenAIRE

    Felice Iavernaro; Donato Trigiante

    2007-01-01

    Discrete mathematics has been neglected for a long time. It has been put in the shade by the striking success of continuous mathematics in the last two centuries, mainly because continuous models in physics proved very reliable, but also because of the greater difficulty in dealing with it. This perspective has been rapidly changing in the last years owing to the needs of the numerical analysis and, more recently, of the so called discrete physics. In this paper, starting from some sentences o...

  13. Nonlinear Control and Discrete Event Systems

    Science.gov (United States)

    Meyer, George; Null, Cynthia H. (Technical Monitor)

    1995-01-01

    As the operation of large systems becomes ever more dependent on extensive automation, the need for an effective solution to the problem of design and validation of the underlying software becomes more critical. Large systems possesses much detailed structure, typically hierarchical, and they are hybrid. Information processing at the top of the hierarchy is by means of formal logic and sentences; on the bottom it is by means of simple scalar differential equations and functions of time; and in the middle it is by an interacting mix of nonlinear multi-axis differential equations and automata, and functions of time and discrete events. The lecture will address the overall problem as it relates to flight vehicle management, describe the middle level, and offer a design approach that is based on Differential Geometry and Discrete Event Dynamic Systems Theory.

  14. Hierarchical Porous Structures

    Energy Technology Data Exchange (ETDEWEB)

    Grote, Christopher John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-07

    Materials Design is often at the forefront of technological innovation. While there has always been a push to generate increasingly low density materials, such as aero or hydrogels, more recently the idea of bicontinuous structures has gone more into play. This review will cover some of the methods and applications for generating both porous, and hierarchically porous structures.

  15. Results of a Test and Win Contest to Raise Radon Awareness in Urban and Rural Settings

    Science.gov (United States)

    Hahn, Ellen J.; Rayens, Mary Kay; Kercsmar, Sarah E.; Robertson, Heather; Adkins, Sarah M.

    2014-01-01

    Background: Radon is a leading cause of lung cancer, but few test their homes to determine radon levels. Purpose: The study assessed feasibility and success of a Test and Win Contest to promote radon testing in rural and urban communities. Methods: The prospective, quasi-experimental study tested a novel contest to raise radon awareness. Paid and…

  16. Methods of radon remediation in Finnish dwellings; Asuntojen radonkorjauksen menetelmaet

    Energy Technology Data Exchange (ETDEWEB)

    Arvela, H.

    1995-12-01

    A study was made of remedial measures taken in dwellings with high indoor radon concentrations and the results obtained. The data regarding the remedial measures taken in 400 dwellings was obtained from a questionnaire study. The mean annual average indoor radon concentration before the remedies was 1.500 Bq/m{sup 3}, the concentration exceeding in nearly every house the action level of 400 Bq/m{sup 3}. After the measures were taken the mean indoor radon concentration was 500 Bq/m{sup 3}. The resulting indoor radon concentration was less than 400 Bq/m{sup 3} in 60 percent of the dwellings. The best results were achieved using sub-slab-suction and radon well. These methods effectively decrease both the flow of radon bearing air from soil into dwellings and the radon concentration of leakage air. Typical reduction rates in radon concentration were 70-95 percent. The action level was achieved in more than 70 percent of the houses. Sealing the entry routes and improvement of the ventilation resulted typically in reduction rates of 10-50 percent. The goal of the report is to give useful information for the house owners, the do-it-yourself-mitigators, the mitigation firms and the local authorities. The report includes practical guidance, price information and examples of remedial measures. (13 refs., 10 figs., 2 tabs.).

  17. Environmental Radon Gas and Degenerative Conditions An Overview

    Energy Technology Data Exchange (ETDEWEB)

    Groves-Kirkby, C.J. [Medical Physics Department, Northampton General Hospital, Northampton NN1 5BD (United Kingdom)]|[School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom); Denman, A.R. [Medical Physics Department, Northampton General Hospital, Northampton NN1 5BD (United Kingdom); Woolridge, A.C. [School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom)]|[School of Applied Sciences, University of Northampton, Northampton NN2 7AL (United Kingdom); Phillips, P.S. [School of Applied Sciences, University of Northampton, Northampton NN2 7AL (United Kingdom); Phillips, C. [School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom)

    2006-07-01

    Radon, a naturally occurring radioactive gas, has variable distribution in the environment as a decay product of uranium occurring in a wide range of rocks, soils and building materials. Although radon dissipates rapidly in outdoor air, it concentrates in the built environment, and inhalation of {sup 222}Rn and its progeny {sup 218}Po and {sup 214}Po is believed to provide the majority of the radioactive dose to the respiratory system. While the connection between radon and lung cancer has long been recognised and investigated, recent studies have highlighted potential links between radon and other conditions, among them Multiple Sclerosis, Alzheimer and Parkinson Diseases, and Paget Disease of Bone. A strong case exists for clarifying the relationship between radon and these other conditions, not least since radon remediation to reduce lung cancer may conceivably have additional benefits hitherto unrecognized. The present status of the postulated links between environmental radon gas and degenerative conditions is reviewed, and recommendations for further research into levering current anti-radon campaigns are made. (authors)

  18. Molecular dynamics simulations of radon accumulation in water and oil

    Energy Technology Data Exchange (ETDEWEB)

    Pafong, Elvira; Drossel, Barbara [Institut fuer Festkoerperphysik, Technische Universitaet Darmstadt (Germany)

    2016-07-01

    Radon is a radioactive gas that can enter the human body from air or from ground water. Radon can accumulate to levels that considerably rise the risk of lung cancer while it is also known as a a treatment of various ailments, most notably rheumatoid arthritis. The accumulation of radon differs between tissues, with particularly high concentrations in fatty cells. In order to understand the mechanisms responsible for the different solubility of radon in water and fat, we perform molecular dynamics simulations of radon gas at ambient conditions in contact with a bulk material consisting either of water or oil. We evaluate the diffusion coefficient of radon in both media as well as the equilibrium concentration. The crucial point here is to understand the hydrophobic interaction between water and radon as compared to the dispersive interaction between radon and oil. Therefore, we artificially vary the water charges (i.e., the hydrophobicity) as well as the parameters of the van-der-Waals interaction.

  19. RADON DIAGNOSTIC MEASUREMENT GUIDANCE FOR LARGE BUILDINGS - VOLUME 2. APPENDICES

    Science.gov (United States)

    The report discusses the development of radon diagnostic procedures and mitigation strategies applicable to a variety of large non-residential buildings commonly found in Florida. The investigations document and evaluate the nature of radon occurrence and entry mechanisms for rad...

  20. Measurements of radon activity concentration in mouse tissues and organs.

    Science.gov (United States)

    Ishimori, Yuu; Tanaka, Hiroshi; Sakoda, Akihiro; Kataoka, Takahiro; Yamaoka, Kiyonori; Mitsunobu, Fumihiro

    2017-05-01

    The purpose of this study is to investigate the biokinetics of inhaled radon, radon activity concentrations in mouse tissues and organs were determined after mice had been exposed to about 1 MBq/m(3) of radon in air. Radon activity concentrations in mouse blood and in other tissues and organs were measured with a liquid scintillation counter and with a well-type HP Ge detector, respectively. Radon activity concentration in mouse blood was 0.410 ± 0.016 Bq/g when saturated with 1 MBq/m(3) of radon activity concentration in air. In addition, average partition coefficients obtained were 0.74 ± 0.19 for liver, 0.46 ± 0.13 for muscle, 9.09 ± 0.49 for adipose tissue, and 0.22 ± 0.04 for other organs. With these results, a value of 0.414 for the blood-to-air partition coefficient was calculated by means of our physiologically based pharmacokinetic model. The time variation of radon activity concentration in mouse blood during exposure to radon was also calculated. All results are compared in detail with those found in the literature.

  1. Reporting on Radon: The Role of Local Newspapers.

    Science.gov (United States)

    Post, James F.; And Others

    Noting that past local media coverage of environmental topics, including those dealing with radiation topics, has often been superficial, a study assessed press coverage of the radon problem in the Lehigh Valley region of Pennsylvania during the first nine months of 1985. The study explored whether local media coverage of radon--a colorless,…

  2. Intercomparison 2003 for Radon measurement services at PSI

    CERN Document Server

    Butterweck, G

    2003-01-01

    Twelve radon measurement services participated in the 2003 Radon Intercomparison Exercise performed at the Reference Laboratory for Radon Gas Activity Concentration Measurements at Paul Scherrer Institut (PSI) during March 13th to 24th, 2003. Ten of these laboratories were approved by the Swiss Federal Office of Public Health and their participation in the intercomparison exercise was a requirement to warrant quality of measurement. Radon gas detectors (etched-track and electret ionisation chambers) and instruments (ionisation chambers and electrostatic precipitation) were exposed in the PSI Radon Chamber in a reference atmosphere with an average radon gas concentration of 1950 Bqm sup - sup 3 leading to a radon gas exposure of 517 kBqhm sup - sup 3. Additional five electret-detectors of an approved measuring service were purchased by the Swiss Federal Office of Public Health for a spot check. Two of these were exposed as described above, two had an exposure of 247 kBqhm sup - sup 3 at an average radon concen...

  3. Radon exhalation rate of some building materials used in Egypt.

    Science.gov (United States)

    Maged, A F; Ashraf, F A

    2005-09-01

    Indoor radon has been recognized as one of the health hazards for mankind. Common building materials used for construction of houses, which are considered as one of the major sources of this gas in indoor environment, have been studied for exhalation rate of radon. Non-nuclear industries, such as coal fired power plants or fertilizer production facilities, generate large amounts of waste gypsum as by-products. Compared to other building materials waste gypsum from fertilizer production facilities (phosphogypsum) shows increased rates of radon exhalation. In the present, investigation solid state alpha track detectors, CR-39 plastic detectors, were used to measure the indoor radon concentration and the radon exhalation rates from some building materials used in Egypt. The indoor radon concentration and the radon exhalation rate ranges were found to be 24-55 Bq m(-3 )and 11-223 mBq m(-2) h(-1), respectively. The effective dose equivalent range for the indoor was found 0.6-1.4 mSv y(-1). The equilibrium factor between radon and its daughters increased with the increase of relative humidity.

  4. Residential radon exposure and risk of lung cancer in Missouri.

    Science.gov (United States)

    Alavanja, M C; Lubin, J H; Mahaffey, J A; Brownson, R C

    1999-01-01

    OBJECTIVES: This study investigated residential radon exposure and lung cancer risk, using both standard radon dosimetry and a new radon monitoring technology that, evidence suggests, is a better measure of cumulative radon exposure. METHODS: Missouri women (aged 30 to 84 years) newly diagnosed with primary lung cancer during the period January 1, 1993, to January 31, 1994, were invited to participate in this population-based case-control study. Both indoor air radon detectors and CR-39 alpha-particle detectors (surface monitors) were used. RESULTS: When surface monitors were used, a significant trend in lung cancer odds ratios was observed for 20-year time-weighted-average radon concentrations. CONCLUSIONS: When surface monitors were used, but not when standard radon dosimetry was used, a significant lung cancer risk was found for radon concentrations at and above the action level for mitigation of houses currently used in the United States (148 Bqm-3). The risk was below the action level used in Canada (750 Bqm-3) and many European countries (200-400 Bqm-3). PMID:10394313

  5. Measurement of indoor radon concentration levels in Islamabad, Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, S.U.; Anwar, J. [Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan); Matiullah [PD, PINSTECH Nilore, Islamabad (Pakistan)], E-mail: matiullah@pieas.edu.pk

    2008-08-15

    Indoor radon measurement survey has been carried out in properly selected houses of the city of Islamabad. In this regard, CR-39-based NRPB radon dosimeters were used. The dosimeters were installed at head heights in bedroom and living room of each house. For intercomparison purpose, houses having basements were also selected. In such houses, dosimeters were installed in basements, ground floor and first floor. All the dosimeters were exposed to radon for a period of three months. After exposure, CR-39 detectors were etched for 16 h in 6 M NaOH at 80{sup 0}C and were counted under an optical microscope. The observed track densities were then related to radon concentration levels using a calibration factor of 2.7trackscm{sup -2}h{sup -1}(kBqm{sup -3}){sup -1}. Measured indoor radon concentration levels were found to vary from 11 to 78Bqm{sup -3}. The average radon concentration levels in bedrooms and sitting/living rooms in basements were found to be 40 and 32Bqm{sup -3}, respectively. In bedrooms and living rooms, on ground floor, the average radon concentration levels were found to be 30 and 27Bqm{sup -3}, whereas on first floor the average values were 29 and 27Bqm{sup -3}, respectively. The radon concentration levels found in this study are below the action level recommended by the ICRP.

  6. Characteristics of soil radon transport in different geological formations

    Science.gov (United States)

    Ershaidat, N. M.; Al-Bataina, B. A.; Al-Shereideh, S. A.

    2008-07-01

    Soil radon concentration levels in Deir Abu-Said District, Irbid, Jordan were measured for several depths using CR-39 detectors, in the summer 2004 for six geological formations, namely, Wadi umm ghudran (WG), Wadi esSir “massive” limestone, Amman silicified limestone (ASL), Al-Hisa phosphatic limestone (AHP), Muwaqqar chalky-marl (MCM), and Basalt. Using a model (Yakovleva in Ann Geophys 48(1):195 198, 2005) based on the solution of the diffusion equation in the quasi-homogenous approximation, the characteristics of radon transport were calculated. Radon flux density from the Earth’s surface, the depth Z eq, at which the equilibrium value of soil radon concentration is reached and the convective radon flux velocity ( v) for the different soils are calculated and found to be consistent with similar values presented elsewhere. Calculations indicate that the soil covering WG has a low radon risk while, on the contrary, AHP has a higher radon risk as expected, since AHP has higher content of uranium. The other formations have intermediate values. The results of the present study confirm the statement by Yakovleva (Ann Geophys 48(1):195 198, 2005) that two measurements suffice in order to estimate the characteristics of soil radon transport.

  7. RADON REDUCTION TECHNIQUES FOR DETACHED HOUSES, TECHNICAL GUIDANCE (SECOND EDITION)

    Science.gov (United States)

    This document is intended for use by State officials, radon mitigation contractors, building contractors, concerned homeowners, and other persons as an aid in the selection, design, and operation of radon reduction measurements for houses. It is the second edition of EPA's techn...

  8. Survey of radon and thoron in homes of Indian Himalaya.

    Science.gov (United States)

    Ramola, Rakesh Chand

    2011-07-01

    Measurements of radon, thoron and their progeny were carried out in some houses from Garhwal and Kumaun Himalayas of India using a LR-115 plastic track detector. The measurements were made in various residential houses of the area at a height of 2.5 m above the ground level using a twin chamber radon dosemeter, which can record the values of radon, thoron and their progeny separately. The concentrations of radon and thoron in these homes were found to vary from 11 to 191 and 1 to 156 Bq m(-3), respectively. The equilibrium factor between radon and progeny varies from 0.02 to 0.90, with an average of 0.26 for the region. The resulting dose rate due to radon, thoron and their decay products was found to vary from 0.02 to 0.84 μSv h(-1) with an arithmetic mean of 0.27 μSv h(-1). A detailed analysis of the distribution of radon, thoron and their decay products inside a house is also reported. The observed dose rates due to radon, thoron and progeny were found somewhat higher but well below the international recommendations.

  9. Measurement of indoor radon levels in the Bologna metropolitan area

    Energy Technology Data Exchange (ETDEWEB)

    Beozzo, M. (ENEA, Bologna (Italy)); Bottazzi, E.; Calligola, P. (Istituto Nazionale di Fisica Nucleare, Bologna (Italy)) (and others)

    1991-01-01

    Indoor radon concentrations in Bologna were monitored using two types of detectors with different characteristics. The detectors were the polymeric track detector, CR-39, and activated charcoal. The measurements gave consistent results. It has been verified that the radon concentration in Bologna is well below the 'attention' level given in the scientific literature. (author).

  10. The Harmonic Decomposition Reconstruction for the Exponential Radon Transform

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The exponential Radon transform, a generalization of the Radon transform, is defined andstudied as a mapping of function spaces. It is represented in terms of Fourier transform of its domain andrange, and this leads to the harmonic decomposition reconstruction. The results are similar results of Tre-tiak and Metz.

  11. Study of indoor radon distribution using measurements and CFD modeling.

    Science.gov (United States)

    Chauhan, Neetika; Chauhan, R P; Joshi, M; Agarwal, T K; Aggarwal, Praveen; Sahoo, B K

    2014-10-01

    Measurement and/or prediction of indoor radon ((222)Rn) concentration are important due to the impact of radon on indoor air quality and consequent inhalation hazard. In recent times, computational fluid dynamics (CFD) based modeling has become the cost effective replacement of experimental methods for the prediction and visualization of indoor pollutant distribution. The aim of this study is to implement CFD based modeling for studying indoor radon gas distribution. This study focuses on comparison of experimentally measured and CFD modeling predicted spatial distribution of radon concentration for a model test room. The key inputs for simulation viz. radon exhalation rate and ventilation rate were measured as a part of this study. Validation experiments were performed by measuring radon concentration at different locations of test room using active (continuous radon monitor) and passive (pin-hole dosimeters) techniques. Modeling predictions have been found to be reasonably matching with the measurement results. The validated model can be used to understand and study factors affecting indoor radon distribution for more realistic indoor environment.

  12. Applications of a silicon photodiode detector for radon progeny measurements

    CERN Document Server

    Voytchev, M; Chambaudet, A; Georgiev, G; Iovtchev, M

    1999-01-01

    An application of our developed silicon photodiode detector for radon progeny measurements is presented in this paper. It was determined the deposition velocity for free (3.6+-0.7)x10 sup - sup 3 m s sup - sup 1 and attached (1.0+-0.5)x10 sup - sup 5 m s sup - sup 1 fraction of short living radon progeny.

  13. Ultra-low level radon assays in gases

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xin Ran [University College London, Gower Street, London, WC1E 6BT (United Kingdom)

    2015-08-17

    The SuperNEMO experiment aims to search for the neutrinoless double beta decay (0νβ β) to T{sub 1{sub /{sub 2}}}(0ν) > 10{sup 26} years, this corresponds to an effective neutrino mass of 50-100 meV. The extremely rare event rate means the minimisation of background is of critical concern. The stringent strategy instigated to ensure detector radiopurity is outlined here for all construction materials. In particular the large R&D programme undertaken to reach the challengingly low level of radon, < 0.15 mBq/m{sup 3}, required inside the SuperNEMO gaseous tracker will be detailed. This includes an experiment designed to measure radon diffusion through various materials. A “Radon Concentration Line” (RnCL) was developed to be used in conjunction with a state-of-the-art radon detector in order to achieve world leading sensitivity to {sup 222}Rn content in large gas volumes at the level of a few µBq/m{sup 3}. A radon purification system was developed and installed which has demonstrated radon suppression by several orders of magnitude depending on the carrier gas. This apparatus has now been commissioned and measurements of cylindered gas have been made to confirm radon suppression by a factor 20 when using nitrogen as the carrier gas. The results from measurements of radon content in various gases, used inside SuperNEMO, using the RnCL will be presented.

  14. Radon removal from gaseous xenon with activated charcoal

    Energy Technology Data Exchange (ETDEWEB)

    Abe, K.; Hieda, K.; Hiraide, K.; Hirano, S.; Kishimoto, Y.; Kobayashi, K.; Koshio, Y. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Liu, J.; Martens, K. [Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Moriyama, S. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Nakahata, M. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nishiie, H.; Ogawa, H.; Sekiya, H.; Shinozaki, A. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Suzuki, Y. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Takachio, O.; Takeda, A.; Ueshima, K.; Umemoto, D. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); and others

    2012-01-01

    Many low background experiments using xenon need to remove radioactive radon to improve their sensitivities. However, no method of continually removing radon from xenon has been described in the literature. We studied a method to remove radon from xenon gas through an activated charcoal trap. From our measurements we infer a linear relationship between the mean propagation velocity v{sub Rn} of radon and v{sub Xe} of xenon in the trap with v{sub Rn}/v{sub Xe}=(0.96{+-}0.10) Multiplication-Sign 10{sup -3} at -85 Degree-Sign C. As the mechanism for radon removal in this charcoal trap is its decay, knowledge of this parameter allows us to design an efficient radon removal system for the XMASS experiment. The verification of this system found that it reduces radon by a factor of 0.07, which is in line with its expected average retention time of 14.8 days for radon.

  15. Methods for measuring diffusion coefficients of radon in building materials

    NARCIS (Netherlands)

    Cozmuta, [No Value; van der Graaf, ER

    2001-01-01

    Two methods for determining the Rn-222 diffusion coefficient in concrete are presented. Experimentally, the flush and adsorption technique to measure radon release rates underlines both methods. Theoretically, the first method was developed fur samples of cubical geometry. The radon diffusion

  16. RADON DIAGNOSTIC MEASUREMENT GUIDANCE FOR LARGE BUILDINGS - VOLUME 2. APPENDICES

    Science.gov (United States)

    The report discusses the development of radon diagnostic procedures and mitigation strategies applicable to a variety of large non-residential buildings commonly found in Florida. The investigations document and evaluate the nature of radon occurrence and entry mechanisms for rad...

  17. Reporting on Radon: The Role of Local Newspapers.

    Science.gov (United States)

    Post, James F.; And Others

    Noting that past local media coverage of environmental topics, including those dealing with radiation topics, has often been superficial, a study assessed press coverage of the radon problem in the Lehigh Valley region of Pennsylvania during the first nine months of 1985. The study explored whether local media coverage of radon--a colorless,…

  18. Radon detection and measurement. (Latest citations from the EI compendex*plus database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    The bibliography contains citations concerning the measurement of radon and radon daughter isotopes in various environments. Radon measurement in homes and buildings, mines, rainwater, groundwater, soils, the Arctic and other atmosphere, and exhaled air is discussed. Radon exhalation rates of building materials and mine tailings are noted. Analytical methods and equipment used to measure radon and radon isotopes are described. Radon detection as an earthquake prediction tool is briefly presented.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  19. A generalization of the Funk-Radon transform

    Science.gov (United States)

    Quellmalz, Michael

    2017-03-01

    The Funk-Radon transform assigns to a function on the two-sphere its mean values along all great circles. We consider the following generalization: we replace the great circles by the small circles being the intersection of the sphere with planes containing a common point {\\boldsymbol{\\zeta }} inside the sphere. If {\\boldsymbol{\\zeta }} is the origin, this is just the classical Funk-Radon transform. We find two mappings from the sphere to itself that enable us to represent the generalized Radon transform in terms of the Funk-Radon transform. This representation is utilized to characterize the nullspace and range as well as to prove an inversion formula of the generalized Radon transform.

  20. Radon diffusion through multilayer earthen covers: models and simulations

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, D.W.; Oster, C.A.; Nelson, R.W.; Gee, G.W.

    1981-09-01

    A capability to model and analyze the fundamental interactions that influence the diffusion of radon gas through uranium mill tailings and cover systems has been investigated. The purpose of this study is to develop the theoretical basis for modeling radon diffusion and to develop an understanding of the fundamental interactions that influence radon diffusion. This study develops the theoretical basis for modeling radon diffusion in one, two and three dimensions. The theory has been incorporated into three computer models that are used to analyze several tailings and cover configurations. This report contains a discussion of the theoretical basis for modeling radon diffusion, a discussion of the computer models used to analyze uranium mill tailings and multilayered cover systems, and presents the results that have been obtained.

  1. Comparison of seasonal variability in European domestic radon measurements

    Directory of Open Access Journals (Sweden)

    C. J. Groves-Kirkby

    2010-03-01

    Full Text Available Analysis of published data characterising seasonal variability of domestic radon concentrations in Europe and elsewhere shows significant variability between different countries and between regions where regional data is available. Comparison is facilitated by application of the Gini Coefficient methodology to reported seasonal variation data. Overall, radon-rich sedimentary strata, particularly high-porosity limestones, exhibit high seasonal variation, while radon-rich igneous lithologies demonstrate relatively constant, but somewhat higher, radon concentrations. High-variability regions include the Pennines and South Downs in England, Languedoc and Brittany in France, and especially Switzerland. Low-variability high-radon regions include the granite-rich Cornwall/Devon peninsula in England, and Auvergne and Ardennes in France, all components of the Devonian-Carboniferous Hercynian belt.

  2. Radon depletion in xenon boil-off gas

    Energy Technology Data Exchange (ETDEWEB)

    Bruenner, S.; Cichon, D.; Lindemann, S.; Undagoitia, T.M.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    2017-03-15

    An important background in detectors using liquid xenon for rare event searches arises from the decays of radon and its daughters. We report for the first time a reduction of {sup 222}Rn in the gas phase above a liquid xenon reservoir. We show a reduction factor of >or similar 4 for the {sup 222}Rn concentration in boil-off xenon gas compared to the radon enriched liquid phase. A semiconductor-based α-detector and miniaturized proportional counters are used to detect the radon. As the radon depletion in the boil-off gas is understood as a single-stage distillation process, this result establishes the suitability of cryogenic distillation to separate radon from xenon down to the 10{sup -15} mol/mol level. (orig.)

  3. Radon depletion in xenon boil-off gas

    CERN Document Server

    Bruenner, S; Lindemann, S; Undagoitia, T Marrodán; Simgen, H

    2016-01-01

    An important background in detectors using liquid xenon for rare event searches arises from the decays of radon and its daughters. We report for the first time a reduction of $^{222}$Rn in the gas phase above a liquid xenon reservoir. We show a reduction factor of $\\gtrsim 4$ for the $^{222}$Rn concentration in boil-off xenon gas compared to the radon enriched liquid phase. A semiconductor-based $\\alpha$-detector and miniaturized proportional counters are used to detect the radon. As the radon depletion in the boil-off gas is understood as a single-stage distillation process, this result establishes the suitability of cryogenic distillation to separate radon from xenon down to the $10^{-15}\\,$mol/mol level.

  4. Indoor Radon Measurement In The City Of Edirne, Turkey

    Science.gov (United States)

    Bozkurt, A.; Kam, E.

    2007-04-01

    This study assesses the indoor radon concentrations for the city of Edirne situated in the European part of Turkey (Eastern Thrace). A total of 88 CR-39 nuclear track detectors were kept in basements of the selected apartment buildings and houses for passively determining the indoor radon levels of the dwellings for a period of three months. The detectors were then collected and a chemical process of etching was applied to the films. At this stage, the tracks left by alpha particles on the films exposed to radon gas were visible and were counted with a microscope (500×magnification) to estimate the corresponding indoor radon concentrations. The average indoor radon concentration was found to be 49.2 Bq/m3 equivalent to an annual effective dose of 1.24 mSv. The measurement results obtained in this study show no significant departure from the other parts of the country.

  5. Radon surveys in Ajloun city using CR-39 detectors

    Energy Technology Data Exchange (ETDEWEB)

    Rabadi, Douha R. [Physics Department, Faculty of Science, Yarmouk University, Irbid 21163 (Jordan); Abumurad, Khalid M. [Physics Department, Faculty of Science, Yarmouk University, Irbid 21163 (Jordan)], E-mail: abumurad@yu.edu.jo

    2008-08-15

    In the present study radon ({sup 222}Rn) concentrations in dwellings, soil and water at Ajloun city was performed by using CR-39. The detectors were chemically etched and the alpha track density was measured using an optical microscope. The average indoor radon concentration for the whole survey was 27.6{+-}1.8Bqm{sup -3}. Differences were found at the different floors: 31.1{+-}4.4, 23.8{+-}3.6 and 19.7{+-}3.2Bqm{sup -3} for the 1st, 2nd and 3rd floors, respectively. Furthermore, the average concentration of radon in soil air was 3.4{+-}1.4kBqm{sup -3}. In addition, the average radon level in water samples from different water springs was 2.0{+-}0.3Bql{sup -1}. However, the average concentration of radon in Ajloun city is lower than the national average ({approx}40.0Bqm{sup -3})

  6. Experimental, statistical, and biological models of radon carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Cross, F.T.

    1991-09-01

    Risk models developed for underground miners have not been consistently validated in studies of populations exposed to indoor radon. Imprecision in risk estimates results principally from differences between exposures in mines as compared to domestic environments and from uncertainties about the interaction between cigarette-smoking and exposure to radon decay products. Uncertainties in extrapolating miner data to domestic exposures can be reduced by means of a broad-based health effects research program that addresses the interrelated issues of exposure, respiratory tract dose, carcinogenesis (molecular/cellular and animal studies, plus developing biological and statistical models), and the relationship of radon to smoking and other copollutant exposures. This article reviews experimental animal data on radon carcinogenesis observed primarily in rats at Pacific Northwest Laboratory. Recent experimental and mechanistic carcinogenesis models of exposures to radon, uranium ore dust, and cigarette smoke are presented with statistical analyses of animal data. 20 refs., 1 fig.

  7. Application of activated charcoal radon collectors in high humidity environments

    Energy Technology Data Exchange (ETDEWEB)

    Iimoto, Takeshi E-mail: iimoto@rcnst.u-tokyo.ac.jp; Tokonami, Shinji; Morishita, Yasuaki; Kosako, Toshiso

    2004-09-01

    Most commercially based activated charcoal radon collectors were designed for use in indoor environments. However, at present, they are often used for research in radon surveys in unique environments, such as in the bathrooms, underground areas, mines, caves and tunnels. In these environments, the relative humidity would be around 100%, and a change in the sensitivity of cpm(Bq m{sup -3}){sup -1}(radon) would occur. For this study, the reduction in the sensitivity of activated charcoal radon collector due to environmental humidity was investigated, and the data correction was discussed. Here, ST-100 (Pico-Rad) was selected as an example of a familiar activated charcoal radon collector. According to our performance test, the humidity of 90% (20 deg. C) resulted in a 15% reduction of the sensitivity for 24 h collection. The ST-100 user should discuss the necessity of data correction by comparing the change of sensitivity with other levels of estimation errors.

  8. Application of activated charcoal radon collectors in high humidity environments.

    Science.gov (United States)

    Iimoto, Takeshi; Tokonami, Shinji; Morishita, Yasuaki; Kosako, Toshiso

    2005-01-01

    Most commercially based activated charcoal radon collectors were designed for use in indoor environments. However, at present, they are often used for research in radon surveys in unique environments, such as in the bathrooms, underground areas, mines, caves and tunnels. In these environments, the relative humidity would be around 100%, and a change in the sensitivity of cpm(Bq m(-3))(-1)(radon) would occur. For this study, the reduction in the sensitivity of activated charcoal radon collector due to environmental humidity was investigated, and the data correction was discussed. Here, ST-100 (Pico-Rad) was selected as an example of a familiar activated charcoal radon collector. According to our performance test, the humidity of 90% (20 degrees C) resulted in a 15% reduction of the sensitivity for 24 h collection. The ST-100 user should discuss the necessity of data correction by comparing the change of sensitivity with other levels of estimation errors.

  9. Statistical uncertainty analysis of radon transport in nonisothermal, unsaturated soils

    Energy Technology Data Exchange (ETDEWEB)

    Holford, D.J.; Owczarski, P.C.; Gee, G.W.; Freeman, H.D.

    1990-10-01

    To accurately predict radon fluxes soils to the atmosphere, we must know more than the radium content of the soil. Radon flux from soil is affected not only by soil properties, but also by meteorological factors such as air pressure and temperature changes at the soil surface, as well as the infiltration of rainwater. Natural variations in meteorological factors and soil properties contribute to uncertainty in subsurface model predictions of radon flux, which, when coupled with a building transport model, will also add uncertainty to predictions of radon concentrations in homes. A statistical uncertainty analysis using our Rn3D finite-element numerical model was conducted to assess the relative importance of these meteorological factors and the soil properties affecting radon transport. 10 refs., 10 figs., 3 tabs.

  10. Detection of earthquake induced radon precursors by Hilbert Huang Transform

    Science.gov (United States)

    Barman, Chiranjib; Ghose, Debasis; Sinha, Bikash; Deb, Argha

    2016-10-01

    Continuous measurement of radon-222 concentration in soil was carried out across duration of one year at a geologically faulted area having high regional heat flow to detect anomalies caused by seismic activities. The data reveals a range of periodicities present in the radon time series. To identify seismic induced radon changes we treat the time series data through various filtering methods to remove inherent periodicities. The Ensemble Empirical Mode Decomposition (EEMD) is deployed to decompose the signal into its characteristic modes. Hilbert Huang Transform (HHT) is applied for the first time on the physically significant modes obtained by EEMD to represent time-energy-frequency of the recorded soil radon time series. After removing the periodic and quasi-periodic constituents from the original time series, the simulated result shows a forceful correlation in recorded radon-222 anomalies with regional and local seismic events.

  11. Anomalous radon emanation linked to preseismic electromagnetic phenomena

    Directory of Open Access Journals (Sweden)

    Y. Omori

    2007-10-01

    Full Text Available Anomalous emanation of radon (222Rn was observed preceding large earthquakes and is considered to be linked to preseismic electromagnetic phenomena (e.g. great changes of atmospheric electric field and ionospheric disturbances. Here we analyze atmospheric radon concentration and estimate changes of electrical conditions in atmosphere due to preseismic radon anomaly. The increase of radon emanation obeys crustal damage evolution, following a power-law of time-to-earthquake. Moreover, the radon emanation decreases the atmospheric electric field by 40%, besides influencing the maximum strength of atmospheric electric field by 104–105 V/m enough to trigger ionospheric disturbances. These changes are within the ranges observed or explaining electromagnetic phenomena associated with large earthquakes.

  12. Radon depletion in xenon boil-off gas

    Science.gov (United States)

    Bruenner, S.; Cichon, D.; Lindemann, S.; Undagoitia, T. Marrodán; Simgen, H.

    2017-03-01

    An important background in detectors using liquid xenon for rare event searches arises from the decays of radon and its daughters. We report for the first time a reduction of ^{222}Rn in the gas phase above a liquid xenon reservoir. We show a reduction factor of ≳ 4 for the ^{222}Rn concentration in boil-off xenon gas compared to the radon enriched liquid phase. A semiconductor-based α -detector and miniaturized proportional counters are used to detect the radon. As the radon depletion in the boil-off gas is understood as a single-stage distillation process, this result establishes the suitability of cryogenic distillation to separate radon from xenon down to the 10^{-15} mol/mol level.

  13. A theoretical treatment of adsorption of radon gas on charcoal

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ding; Chiang, Hai-Pang; Shiau, Yuo-Hsien; Tse, Wan-Sun [Academia Sinica, Taipei, TW (China). Inst. of Physics; Skrable, K.; Li, Kuang-Pang

    1997-09-01

    The use of an activated charcoal sampler for radon monitoring has become popular in recent years because of its passiveness and low price. Dynamics of adsorption on a passive sampler have been described with theoretical models. However, extrapolation of the measured results of radon on charcoal to the diurnal fluctuations of the ambient radon concentration is often difficult and even misleading because of the oversimplification of these models. A more generalized approach is undertaken by treating the diurnal variations in radon concentrations as poly-exponential functions and by solving for explicit particular solutions of Fick`s equation. The application of these solutions to various practical situations is explored. This includes their use for charcoal sampler calibration. Estimated values of the adsorption coefficients, k, and diffusion constant, D, appear to be agreeable with corresponding reported values. A triple-sampler protocol is also proposed for radon survey in areas of high diurnal fluctuations. (author)

  14. Is radon a potential risk in geothermal fields?

    Energy Technology Data Exchange (ETDEWEB)

    Balcazar, M.; Tavera, L.; Lopez, A. [Instituto Nacional de Investigaciones Nucleares, Mexico City (Mexico)

    1998-12-31

    Some environmental groups in Mexico have shown concern, by the fact that natural radon emanation in geothermal fields could be considered as a potential risk for human health. As part of the studies recommended by the Ministry of Energy and to provide technical answers to the request of environmental groups, a study of the radon emanation and its impact to human health was carried out at the Primavera Mexican geothermal energy field under prospecting. It was found that radon concentration decreases with temperature of geothermal fluids and increases with the enthalpy of the well. In any case, using the appropriate corrections, radon values were similar to those of ground water. Radon values in the atmosphere of the field show no potential risk for human health. (author)

  15. Variance of indoor radon concentration: Major influencing factors.

    Science.gov (United States)

    Yarmoshenko, I; Vasilyev, A; Malinovsky, G; Bossew, P; Žunić, Z S; Onischenko, A; Zhukovsky, M

    2016-01-15

    Variance of radon concentration in dwelling atmosphere is analysed with regard to geogenic and anthropogenic influencing factors. Analysis includes review of 81 national and regional indoor radon surveys with varying sampling pattern, sample size and duration of measurements and detailed consideration of two regional surveys (Sverdlovsk oblast, Russia and Niška Banja, Serbia). The analysis of the geometric standard deviation revealed that main factors influencing the dispersion of indoor radon concentration over the territory are as follows: area of territory, sample size, characteristics of measurements technique, the radon geogenic potential, building construction characteristics and living habits. As shown for Sverdlovsk oblast and Niška Banja town the dispersion as quantified by GSD is reduced by restricting to certain levels of control factors. Application of the developed approach to characterization of the world population radon exposure is discussed.

  16. Analysis of soil radon data in earthquake precursory studies

    Directory of Open Access Journals (Sweden)

    Hari Prasad Jaishi

    2014-10-01

    Full Text Available Soil radon data were recorded at two selected sites along Mat fault in Mizoram (India, which lies in the highest seismic zone in India. The study was carried out during July 2011 to May 2013 using LR-115 Type II films. Precursory changes in radon concentration were observed prior to some earthquakes that occurred around the measuring sites. Positive correlation was found between the measured radon data and the seismic activity in the region. Statistical analysis of the radon data together with the meteorological parameters was done using Multiple Regression Method. Results obtained show that the method employed was useful for removing the effect of meteorological parameters and to identify radon maxima possibly caused by seismic activity.

  17. Radon concentrations in schools of the Neapolitan area

    Energy Technology Data Exchange (ETDEWEB)

    Venoso, G.; De Cicco, F. [Universita degli Studi di Napoli Federico II, Dipartimento di Scienze Fisiche (Italy); Flores, B. [Escuela Superior Politecnica de Chimborazo, Riobamba (Ecuador); Gialanella, L. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Napoli (Italy); Pugliese, M. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Napoli (Italy); Universita degli Studi di Napoli Federico II, Dipartimento di Scienze Fisiche (Italy); Roca, V. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Napoli (Italy); Universita degli Studi di Napoli Federico II, Dipartimento di Scienze Fisiche (Italy)], E-mail: roca@na.infn.it; Sabbarese, C. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Napoli (Italy); Seconda Universita degli studi di Napoli, Dipartimento di Scienze Ambientali, Caserta (Italy)

    2009-01-15

    A radon survey was carried out in 30 schools located in the metropolitan area around Naples, Italy. Radon concentration was measured using the SSNTD (Solid State Nuclear Track Detectors) method with LR115 detectors. Time integrated measurements covered two consecutive 6-month periods at different locations inside the school buildings: classrooms, laboratories and offices. Data distribution is well fitted by a log-normal curve. The arithmetic mean annual radon concentration is 144 Bq m{sup -3}, the geometric mean is 86 Bq m{sup -3}; the standard deviations are respectively 7 Bq m{sup -3} and 3. The fractions of rooms where radon concentrations exceed the reference levels of 200, 400 and 500 Bq m{sup -3} are 21.3%, 7.6% and 4.5% respectively. The results show that radon concentration in scientific laboratories and in offices is higher than in classrooms.

  18. A theoretical study of radon measurement with activated charcoal

    Science.gov (United States)

    Nikezić, Dragoslav; Urošević, Vlade

    1998-02-01

    Diffusion of radon in a bed of activated charcoal is described by diffusion equations. An analytical solution of these equations is presented for the case of constant radon concentration in the atmosphere. The solutions are given separately for short term and long term exposure. An analytical form of the calibration constant f for long term exposure and constant radon concentration in air, was found to be f=kp {D}/{λ}S {sinh{λ}/{D}l }/{cosh{λ}/{D}l } A numerical method and computer code based on the method of finite elements is developed for the case of variable radon concentration in air. This program simulates radon adsorption by the activated charcoal bed, enabling determination of sensitivity. The dependence of sensitivity on different parameters, such as temperature, thickness of the charcoal, etc. was studied using this program.

  19. Finite Discrete Gabor Analysis

    DEFF Research Database (Denmark)

    Søndergaard, Peter Lempel

    2007-01-01

    on the real line to be well approximated by finite and discrete Gabor frames. This method of approximation is especially attractive because efficient numerical methods exists for doing computations with finite, discrete Gabor systems. This thesis presents new algorithms for the efficient computation of finite...

  20. Discrete Mathematics Re "Tooled."

    Science.gov (United States)

    Grassl, Richard M.; Mingus, Tabitha T. Y.

    1999-01-01

    Indicates the importance of teaching discrete mathematics. Describes how the use of technology can enhance the teaching and learning of discrete mathematics. Explorations using Excel, Derive, and the TI-92 proved how preservice and inservice teachers experienced a new dimension in problem solving and discovery. (ASK)

  1. Discrete Quantum Mechanics

    CERN Document Server

    Chang, Lay Nam; Minic, Djordje; Takeuchi, Tatsu

    2012-01-01

    We construct a discrete quantum mechanics using a vector space over the Galois field GF(q). We find that the correlations in our model do not violate the Clauser-Horne-Shimony-Holt (CHSH) version of Bell's inequality, despite the fact that the predictions of this discrete quantum mechanics cannot be reproduced with any hidden variable theory.

  2. STUDY OF RADON FLUX FROM SOIL IN BUDHAKEDAR REGION USING SRM.

    Science.gov (United States)

    Bourai, A A; Aswal, Sunita; Kandari, Tushar; Kumar, Shiv; Joshi, Veena; Sahoo, B K; Ramola, R C

    2016-10-01

    In the present study, the radon flux rate of the soil is measured using portable radon monitor (scintillation radon monitor) in the Budhakedar region of District Tehri, India. The study area falls along a fault zone named Main Central Thrust, which is relatively rich in radium-bearing minerals. Radon flux rate from the soil is one of the most important factors for the evaluation of environmental radon levels. The earlier studies in the Budhakedar region shows a high level of radon (>4000 Bq m(-3)). Hence, it is important to measure the radon flux rate. The aim of the present study is to calculate the average estimate of the surface radon flux rate as well as the effective mass exhalation rate. A positive correlation of 0.54 was found between radon flux rate and radon mass exhalation rate. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Radon resistant potential of concrete manufactured using Ordinary Portland Cement blended with rice husk ash

    Science.gov (United States)

    Chauhan, R. P.; Kumar, Amit

    2013-12-01

    The emission of radon from building materials and soil depends upon the radium content, porosity, moisture content and radon diffusion length of materials. Several techniques have been used to reduce the radon emission from the soil using different flooring materials. But the effectiveness of radon shielding depends upon the diffusion of radon through these materials. The present study proposes a method for producing a radon resistant material for decreasing radon diffusion through it. The method involves rice husk ash (RHA) in addition to cement for the preparation of concrete used for flooring and walls. The radon diffusion, exhalation and mechanical property of concrete prepared by rice husk ash blended cement were studied. The addition of RHA caused the reduction in radon diffusion coefficient, exhalation rates, porosity and enhanced the compressive strength of concrete. The bulk radon diffusion coefficient of cementitious concrete was reduced upto 69% by addition of rice husk ash as compare to that of control concrete.

  4. Discrete Control Systems

    CERN Document Server

    Lee, Taeyoung; McClamroch, N Harris

    2007-01-01

    Discrete control systems, as considered here, refer to the control theory of discrete-time Lagrangian or Hamiltonian systems. These discrete-time models are based on a discrete variational principle, and are part of the broader field of geometric integration. Geometric integrators are numerical integration methods that preserve geometric properties of continuous systems, such as conservation of the symplectic form, momentum, and energy. They also guarantee that the discrete flow remains on the manifold on which the continuous system evolves, an important property in the case of rigid-body dynamics. In nonlinear control, one typically relies on differential geometric and dynamical systems techniques to prove properties such as stability, controllability, and optimality. More generally, the geometric structure of such systems plays a critical role in the nonlinear analysis of the corresponding control problems. Despite the critical role of geometry and mechanics in the analysis of nonlinear control systems, non...

  5. Discrete Element Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Morris, J; Johnson, S

    2007-12-03

    The Distinct Element Method (also frequently referred to as the Discrete Element Method) (DEM) is a Lagrangian numerical technique where the computational domain consists of discrete solid elements which interact via compliant contacts. This can be contrasted with Finite Element Methods where the computational domain is assumed to represent a continuum (although many modern implementations of the FEM can accommodate some Distinct Element capabilities). Often the terms Discrete Element Method and Distinct Element Method are used interchangeably in the literature, although Cundall and Hart (1992) suggested that Discrete Element Methods should be a more inclusive term covering Distinct Element Methods, Displacement Discontinuity Analysis and Modal Methods. In this work, DEM specifically refers to the Distinct Element Method, where the discrete elements interact via compliant contacts, in contrast with Displacement Discontinuity Analysis where the contacts are rigid and all compliance is taken up by the adjacent intact material.

  6. Discrete control systems

    CERN Document Server

    Okuyama, Yoshifumi

    2014-01-01

    Discrete Control Systems establishes a basis for the analysis and design of discretized/quantized control systemsfor continuous physical systems. Beginning with the necessary mathematical foundations and system-model descriptions, the text moves on to derive a robust stability condition. To keep a practical perspective on the uncertain physical systems considered, most of the methods treated are carried out in the frequency domain. As part of the design procedure, modified Nyquist–Hall and Nichols diagrams are presented and discretized proportional–integral–derivative control schemes are reconsidered. Schemes for model-reference feedback and discrete-type observers are proposed. Although single-loop feedback systems form the core of the text, some consideration is given to multiple loops and nonlinearities. The robust control performance and stability of interval systems (with multiple uncertainties) are outlined. Finally, the monograph describes the relationship between feedback-control and discrete ev...

  7. Continuity in Discrete Sets

    CERN Document Server

    Burgin, Mark

    2010-01-01

    Continuous models used in physics and other areas of mathematics applications become discrete when they are computerized, e.g., utilized for computations. Besides, computers are controlling processes in discrete spaces, such as films and television programs. At the same time, continuous models that are in the background of discrete representations use mathematical technology developed for continuous media. The most important example of such a technology is calculus, which is so useful in physics and other sciences. The main goal of this paper is to synthesize continuous features and powerful technology of the classical calculus with the discrete approach of numerical mathematics and computational physics. To do this, we further develop the theory of fuzzy continuous functions and apply this theory to functions defined on discrete sets. The main interest is the classical Intermediate Value theorem. Although the result of this theorem is completely based on continuity, utilization of a relaxed version of contin...

  8. Study of the effects of radon in three biological systems; Estudio de los efectos del radon en tres sistemas biologicos

    Energy Technology Data Exchange (ETDEWEB)

    Tavera, L. [Instituto Mexicano del Petroleo, Av. Eje Central Lazaro Cardenas No. 152, Edif. 23, Col. San Mateo Atepehuacan, 07730 Mexico D.F. (Mexico); Balcazar, M.; Lopez, A.; Brena, M. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Rosa, M.E. De la [Facultad de Quimica, UNAM, 04510 Mexico D.F. (Mexico); Villalobos P, R. [Centro de Estudios de la Atmosfera, UNAM, 04510 Mexico D.F. (Mexico)

    2002-07-01

    The radon and its decay products are responsible of the 3/4 parts of the exposure of the persons to the environmental radiation. The discovery at the end of XIX Century of the illnesses, mainly of cancer, which appeared in the presence of radon, lead to an accelerated growing of the radon studies: monitoring, dosimetry, effects on the persons, etc. Several epidemiological studies of radon in miners and population in general have been realized; advancing in the knowledge about the concentration-lung cancer risk relationship, but with discrepancies in the results depending on the concentration levels. Therefor, studies which consuming time, efforts and money go on doing. The research of the radon effects in biological systems different to human, allows to realize studies in less time, in controlled conditions and generally at lower cost, generating information about the alpha radiation effects in the cellular field. Therefor it was decided to study the response of three biological systems exposed to radon: an unicellular bacteria Escherichia Coli which was exposed directly to alpha particles from an electrodeposited source for determining the sensitivity limit of the chose technique. A plant, Tradescantia, for studying the cytogenetic effect of the system exposed to controlled concentrations of radon. An insect, Drosophila Melanogaster, for studying the genetic effects and the accumulated effects in several generations exposed to radon. In this work the experimental settlements are presented for the expositions of the systems and the biological results commenting the importance of these. (Author)

  9. Mapping of the geogenic radon potential in France to improve radon risk management: methodology and first application to region Bourgogne

    Energy Technology Data Exchange (ETDEWEB)

    Ielsch, G., E-mail: geraldine.ielsch@irsn.f [Institut de Radioprotection et de Surete Nucleaire, DEI/SARG/BRN, BP 17, 92262 Fontenay-aux-Roses cedex (France); Cushing, M.E., E-mail: edward.cushing@irsn.f [Institut de Radioprotection et de Surete Nucleaire, DEI/SARG/BRN, BP 17, 92262 Fontenay-aux-Roses cedex (France); Combes, Ph., E-mail: philippe.combes@geoter.f [GEOTER SAS, Geologie Tectonique Environnement et Risques, 3, rue Jean Monnet, 34830 Clapiers (France); Cuney, M., E-mail: michel.cuney@g2r.uhp-nancy.f [CREGU et UMR G2R 7566, Universite Henri Poincare - NANCY I, Domaine Scientifique Victor Grignard, Entree 3B, BP 70 239 - F54 506 Vandoeuvre-les-Nancy Cedex (France)

    2010-10-15

    In order to improve regulatory tools for radon risk management in France, a harmonised methodology to derive a single map of the geogenic radon potential has been developed. This approach consists of determining the capacity of the geological units to produce radon and to facilitate its transfer to the atmosphere, based on the interpretation of existing geological data. This approach is firstly based on a classification of the geological units according to their uranium (U) content, to create a radon source potential map. This initial map is then improved by taking into account the main additional parameters, such as fault lines, which control the preferential pathways of radon through the ground and which can increase the radon levels in soils. The implementation of this methodology to the whole French territory is currently in progress. We present here the results obtained in one region (Bourgogne, Massif Central) which displays significant variations of the geogenic radon potential. The map obtained leads to a more precise zoning than the scale of the existing map of radon priority areas currently based solely on administrative boundaries.

  10. Radon activity in the lower troposphere and its impact on ionization rate: a global estimate using different radon emissions

    Directory of Open Access Journals (Sweden)

    K. Zhang

    2011-01-01

    Full Text Available The radioactive decay of radon and its progeny can lead to ionization of air molecules and consequently influence aerosol size distribution. In order to provide a global estimate of the radon-related ionization rate, we use the global atmospheric model ECHAM5 to simulate transport and decay processes of the radioactive tracers. A global radon emission map is put together using regional fluxes reported recently in the literature. The near-surface radon concentrations simulated with this new map compare well with measurements.

    Radon-related ionization rate is calculated and compared to that caused by cosmic rays. The contribution of radon and its progeny clearly exceeds that of the cosmic rays in the mid- and low-latitude land areas in the surface layer. In winter, strong radon-related ionization coincides with low temperature in China, USA, and Russia, providing favorable condition for the formation of aerosol particles. This suggests that it is probably useful to include the radon-induced ionization in global models when investigating the interaction between aerosol and climate.

  11. Radon activity in the lower troposphere and its impact on ionization rate : a global estimate using different radon emissions

    NARCIS (Netherlands)

    Zhang, K. .; Feichter, J.; Kazil, J.; Wan, H.; Zhuo, W.; Griffiths, A. D.; Sartorius, H.; Zahorowski, W.; Ramonet, M.; Schmidt, Martina; Yver, C.; Neubert, R. E. M.; Brunke, E. -G.; Schulz, M.

    2011-01-01

    The radioactive decay of radon and its progeny can lead to ionization of air molecules and consequently influence aerosol size distribution. In order to provide a global estimate of the radon-related ionization rate, we use the global atmospheric model ECHAM5 to simulate transport and decay

  12. Geographical distribution of indoor radon and related geological characteristics in Bonghwa County, a provisional radon-prone area in Korea.

    Science.gov (United States)

    Lee, E R; Chang, B U; Kim, H J; Song, M H; Kim, Y J

    2015-12-01

    The detailed indoor radon survey was conducted during a year (from September 2012 to August 2013) quarterly in Bonghwa county, one of the provisional radon-prone areas in Korea. The surveyed area was selected on the basis of previously conducted nationwide radon survey results. In order to minimise statistical and environmental uncertainties, ∼3 % of the entire dwellings were carefully selected based on the statistical annual report of Bonghwa county. The measurement is carried out by using solid-state nuclear track detector. The range of indoor radon concentration in each dwelling was 4.36-858 Bq m(-3) and that of annual effective dose due to inhaled radon of the resident in each dwelling was 0.19-23.5 mSv y(-1). Each dwelling was determined for geology criterion using one-way Analysis of Variance for the purpose of comparing indoor radon distribution with geology. Geographical distribution of indoor radon is closely related to the geological characteristics of basement rocks. In addition, the comparison between geographical distribution of indoor radon and terrestrial gamma radiation was done.

  13. Reconstruction of national distribution of indoor radon concentration in Russia using results of regional indoor radon measurement programs.

    Science.gov (United States)

    Yarmoshenko, I; Malinovsky, G; Vasilyev, A; Zhukovsky, M

    2015-12-01

    The aim of the paper is a reconstruction of the national distribution and estimation of the arithmetic average indoor radon concentration in Russia using the data of official annual 4-DOZ reports. Annual 4-DOZ reports summarize results of radiation measurements in 83 regions of Russian Federation. Information on more than 400,000 indoor radon measurements includes the average indoor radon isotopes equilibrium equivalent concentration (EEC) and number of measurements by regions and by three main types of houses: wooden, one-storey non-wooden, and multi-storey non-wooden houses. To reconstruct the national distribution, all-Russian model sample was generated by integration of sub-samples created using the results of each annual regional program of indoor radon measurements in each type of buildings. According to indoor radon concentration distribution reconstruction, all-Russian average indoor radon concentration is 48 Bq/m(3). Average indoor radon concentration by region ranges from 12 to 207 Bq/m(3). The 95-th percentile of the distribution is reached at indoor radon concentration 160 Bq/m(3).

  14. THE RADON-NIKODYM PROPERTY IN SUBSTITUTION SPACE PXXn%置换空间PXXn中的Radon-Nikodym性质

    Institute of Scientific and Technical Information of China (English)

    巩万中; 周文

    2005-01-01

    主要给出了如下结论:设X是具有有界完备超正交基的Banach空间,则置换空间PXXn具有Radon-Nikodym性质当且仅当Xn(n=1,2,…)具有Radon-Nikodym性质,从而推广了文献[1]的结果.

  15. MODELNG RADON ENTRY INTO FLORIDA HOUSES WITH CONCRETE SLABS AND CONCRETE-BLOCK STEM WALLS, FLORIDA RADON RESEARCH PROGRAM

    Science.gov (United States)

    The report discusses results of modeling radon entry into a typical Florida house whose interior is slightly depressurized. he model predicts that the total radon entry rate is relatively low unless the soil or backfill permeability or radium content is high. ost of the factors c...

  16. Biological effects of radon in Drosophila; Efectos biologicos del radon en Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel P, A.E.; Tavera D, L.; Cruces M, M.P.; Arceo M, C.; Rosa D, M.E. de la

    1992-04-15

    The main objective of this investigation, is to study the biological effects of the Radon-222 at low dose in 'Drosophila melanogaster'. It is necessary to mention that these effects will analyze from the genetic point of view for: 1) To evaluate in which form the Radon-222 to low dose it influences in some genetic components of the adaptation in Drosophila, such as: fecundity, viability egg-adult and sex proportion. 2) To evaluate which is the genetic effect that induces the Radon to low dose by means of the SMART technique in Drosophila melanogaster, and this way to try of to identify which is the possible mechanism that causes the genetic damage to somatic level. The carried out investigation was divided in three stages: 1. Tests to the vacuum resistance. 2. Test of somatic mutation, and 3. Determination of the presence of radon daughters on the adult of Drosophila. It is necessary to point out that all the experiments were made by triplicate and in each one of them was placed detectors in preset places. Those obtained results are presented inside the 4 charts included in the present work. (Author)

  17. Risk of Lung Cancer and Indoor Radon Exposure in France

    Energy Technology Data Exchange (ETDEWEB)

    Baysson, H.; Tirmarche, M.; Tymen, G.; Ducloy, F.; Laurier, D.

    2004-07-01

    It is well established that radon exposure increases risks of lung cancer among underground miners. to estimate the lung cancer risk linked to indoor radon exposure, a hospital based case-control study was carried out in France, With a focus on precise reconstruction of past indoor radon exposure over the 30 years preceding the lung cancer diagnosis. The investigation rook place from 1992 to 1998 in four regions of France: Auvergne, Brittany, Languedoc and Limousin. During face-to-face interviews a standardized questionnaire was used to ascertain demographic characteristics, information on active and passive smoking, occupational exposure, medical history as well as extensive details on residential history. Radon concentrations were measured in the dwellings where subjects had lived at least one year during the 5-30 year period before interview. Measurements of radon concentrations were performed during a 6-month period, using two Kodalpha LR 115 detectors, one in the living room and one in the bedroom. The time-weighted average (TWA) radon concentration for a subject during the 5-30 year period before interview was based on radon concentrations over all addresses occupied by the subject weighted by the number of years spent at each address. For the time intervals without available measurements, we imputed the region-specific arithmetic average of radon concentrations for measured addresses of control subjects. Lung cancer risk was examined in relation to indoor radon exposure after adjustment for age, sex, region, cigarette smoking and occupational exposure. The estimated relative a risk per 100 Bq/m''3 was 1.04, at the borderline of statistical significance (95 percent Confidence Interval: 0.99, 1..1). These results are in agreement with results from other indoor radon case-control studies and with extrapolations from underground miners studies. (Author) 31 refs.

  18. Measurement of Radon Concentration in Selected Houses in Ibadan, Nigeria

    Science.gov (United States)

    Usikalu, M. R.; Olatinwo, V.; Akpochafor, M.; Aweda, M. A.; Giannini, G.; Massimo, V.

    2017-05-01

    Radon is a natural radioactive gas without colour or odour and tasteless. The World Health Organization (WHO) grouped radon as a human lung carcinogen. For this reason, there has been a lot of interest on the effects of radon exposure to people all over the world and Nigeria is no exception. The aim of this study is to investigate the radon concentration in selected houses in three local government areas of Ibadan. The indoor radon was measured in both mud and brick houses. Fifty houses were considered from the three Local government areas. A calibrated portable continuous radon monitor type (RAD7) manufactured by Durridge company was used for the measurement. A distance of 100 to 200 m was maintained between houses in all the locations. The living room was kept closed during the measurements. The mean radon concentration measured in Egbeda is 10.54 ±1.30 Bqm -3; Lagelu is 16.90 ± 6.31 Bqm -3 and Ona-Ara is 17.95 ± 1.72 Bqm -3. The mean value of the annual absorbed dose and annual effective dose for the locations in the three local government areas was 0.19 mSvy-1 and 0.48 mSvy-1 respectively. The radon concentration for location 10 in Ono-Ara local government exceeded the recommended limit. However, the overall average indoor radon concentration of the three local governments was found to be lower than the world average value of 40 Bqm -3. Hence, there is need for proper awareness about the danger of radon accumulation in dwelling places.

  19. Multi-scale variability and long-range memory in indoor Radon concentrations from Coimbra, Portugal

    Science.gov (United States)

    Donner, Reik V.; Potirakis, Stelios; Barbosa, Susana

    2014-05-01

    The presence or absence of long-range correlations in the variations of indoor Radon concentrations has recently attracted considerable interest. As a radioactive gas naturally emitted from the ground in certain geological settings, understanding environmental factors controlling Radon concentrations and their dynamics is important for estimating its effect on human health and the efficiency of possible measures for reducing the corresponding exposition. In this work, we re-analyze two high-resolution records of indoor Radon concentrations from Coimbra, Portugal, each of which spans several months of continuous measurements. In order to evaluate the presence of long-range correlations and fractal scaling, we utilize a multiplicity of complementary methods, including power spectral analysis, ARFIMA modeling, classical and multi-fractal detrended fluctuation analysis, and two different estimators of the signals' fractal dimensions. Power spectra and fluctuation functions reveal some complex behavior with qualitatively different properties on different time-scales: white noise in the high-frequency part, indications of some long-range correlated process dominating time scales of several hours to days, and pronounced low-frequency variability associated with tidal and/or meteorological forcing. In order to further decompose these different scales of variability, we apply two different approaches. On the one hand, applying multi-resolution analysis based on the discrete wavelet transform allows separately studying contributions on different time scales and characterize their specific correlation and scaling properties. On the other hand, singular system analysis (SSA) provides a reconstruction of the essential modes of variability. Specifically, by considering only the first leading SSA modes, we achieve an efficient de-noising of our environmental signals, highlighting the low-frequency variations together with some distinct scaling on sub-daily time-scales resembling

  20. Radon exhalation from Libyan soil samples measured with the SSNTD technique.

    Science.gov (United States)

    Saad, A F; Abdallah, R M; Hussein, N A

    2013-02-01

    Radon concentrations in soil samples collected from the cities of Benghazi and Al-Marj, located in northeastern Libya, were measured using the sealed-can technique based on the CR-39 SSNTDs. Mass and areal radon exhalation rates, radium content and radon concentration contribute to indoor radon, and annual effective doses were determined. The results indicate mostly normal rates, but there were some higher levels of radon concentration and emanation in samples collected from Al-Marj and one sample from Benghazi.

  1. Criteria of radon risk of territories and methods for their determination.

    Science.gov (United States)

    Ryzhakova, Nadezhda K

    2014-09-01

    The paper analyzes the values used in the assessment of radon potential of territories. It was shown that the most reliable criterion in the assessment of radon risk of territories can be the value of radon activity concentration fixed at large depths. The authors proposed a simple method to assess this value and radon flux density from the soil surface, based on the measurement of radon activity concentration in soil gas at two twice differing depths and the diffusion model of transport.

  2. Radon concentration in soil gas and radon exhalation rate at the Ravne Fault in NW Slovenia

    Directory of Open Access Journals (Sweden)

    J. Vaupotič

    2010-04-01

    Full Text Available The Ravne tectonic fault in north-west (NW Slovenia is one of the faults in this region, responsible for the elevated seismic activity at the Italian-Slovene border. Five measurement profiles were fixed in the vicinity of the Ravne fault, four of them were perpendicular and one parallel to the fault. At 18 points along these profiles the following measurements have been carried out: radon activity concentration in soil gas, radon exhalation rate from ground, soil permeability and gamma dose rate. The radon measurements were carried out using the AlphaGuard equipment, and GammaTracer was applied for gamma dose rate measurements. The ranges of the obtained results are as follows: 0.9–32.9 kBq m−3 for radon concentration (CRn, 1.1–41.9 mBq m−2 s−1 for radon exhalation rate (ERn, 0.5–7.4×10-13 m2 for soil permeability, and 86–138 nSv h−1 for gamma dose rate. The concentrations of 222Rn in soil gas were found to be lower than the average for Slovenia. Because the deformation zones differ not only in the direction perpendicular to the fault but also along it, the behaviour of either CRn or ERn at different profiles differ markedly. The study is planned to be continued with measurements being carried out at a number of additional points.

  3. Radon in Dwellings in the Republic of Kalmykia

    Energy Technology Data Exchange (ETDEWEB)

    Aakerblom, Gustav (Aakerblom och Aakerblom HP, Skaerholmen (Sweden)); German, Olga; Soederman, Ann-Louise (Swedish Radiation Safety Authority, Stockholm (Sweden)); Stamat, Ivan; Venkov, Vladimir (Research Inst. of Radiation Hygiene, St. Petersburg (Russian Federation))

    2009-02-15

    The National Radon Survey in the Republic of Kalmykia, Russian Federation during 2006-2007 was carried out in a cooperation project between the Swedish Radiation Protection Authority (SSI) and the Russian Institute of Radiation Hygiene (RIRH). In August 2006 SSI, RIRH, federal and local authorities carried out a field study in Kalmykia when radon daughter measurements (equilibrium equivalent radon concentrations in the air) and gamma radiation measurements were made in 103 buildings. Gamma spectrometry measurements were made at several sites. During the visit the cooperating parties devoted some time to the education of local authorities on radon related issues. During three months in the winter season 2006-2007, long term radon trace measurements were made in 525 randomly chosen dwellings in the Republic of Kalmykia. The radon gas activity varied between 3 and 973 Bq/m3, with a mean value of 122 Bq/m3. In 19 of a total of 835 measurement points, the radon activity exceeded the maximum permitted value in Russia of 200 Bq/m3 of EERC. The year-round radon trace measurement were made in 20 houses in Elista, the capital of the Republic of Kalmykia, for comparison with the three-month measurements. The year-round measurements showed some higher values for the radon activity, and a correction factor of 0.85 was applied. Using data on the number of people living in detached houses and apartments, and applying the radon activities measured, the number of new lung cancer cases caused by radon was calculated to be 20 to 40 of the 100 new cases reported annually. The methods of construction of the dwellings in Kalmykia is greatly influenced by the history and culture. Most of them were built after World War II and there are only a few that are newly built because of the poor economic situation and the low population growth rate in the Republic. Most people live in detached houses, one-storied with 3-5 rooms, built directly on the ground or on coquina blocks or on a cast

  4. Fractal Derivative Model for Air Permeability in Hierarchic Porous Media

    Directory of Open Access Journals (Sweden)

    Jie Fan

    2012-01-01

    Full Text Available Air permeability in hierarchic porous media does not obey Fick's equation or its modification because fractal objects have well-defined geometric properties, which are discrete and discontinuous. We propose a theoretical model dealing with, for the first time, a seemingly complex air permeability process using fractal derivative method. The fractal derivative model has been successfully applied to explain the novel air permeability phenomenon of cocoon. The theoretical analysis was in agreement with experimental results.

  5. Canadian population risk of radon induced lung cancer: a re-assessment based on the recent cross-Canada radon survey

    Science.gov (United States)

    Chen, J.; Moir, D.; Whyte, J.

    2012-01-01

    Exposure to indoor radon has been determined to be the second leading cause of lung cancer after tobacco smoking. Canadian population risk of radon induced lung cancer was assessed in 2005 with the radon distribution characteristics determined from a radon survey carried out in the late 1970s in 19 cities. In that survey, a grab sampling method was used to measure radon levels. The observed radon concentration in 14 000 Canadian homes surveyed followed a log–normal distribution with a geometric mean (GM) of 11.2 Bq m–3 and a geometric standard deviation (GSD) of 3.9. Based on the information from that survey, it was estimated that ∼10 % of lung cancers in Canada resulted from indoor radon exposure. To gain a better understanding of radon concentrations in homes across the country, a national residential radon survey was launched in April 2009. In the recent survey, long-term (3 month or longer) indoor radon measurements were made in roughly 14 000 homes in 121 health regions across Canada. The observed radon concentrations follow, as expected, a log–normal distribution with a GM of 41.9 Bq m–3 and a GSD of 2.8. Based on the more accurate radon distribution characteristics obtained from the recent cross-Canada radon survey, a re-assessment of Canadian population risk for radon induced lung cancer was undertaken. The theoretical estimates show that 16 % of lung cancer deaths among Canadians are attributable to indoor radon exposure. These results strongly suggest the ongoing need for the Canadian National Radon Program. In particular, there is a need for a focus on education and awareness by all levels of government, and in partnership with key stakeholders, to encourage Canadians to take action to reduce the risk from indoor radon exposure. PMID:22874897

  6. Comparison of Northern Ireland radon maps based on indoor radon measurements and geology with maps derived by predictive modelling of airborne radiometric and ground permeability data.

    Science.gov (United States)

    Appleton, J D; Miles, J C H; Young, M

    2011-03-15

    Publicly available information about radon potential in Northern Ireland is currently based on indoor radon results averaged over 1-km grid squares, an approach that does not take into account the geological origin of the radon. This study describes a spatially more accurate estimate of the radon potential of Northern Ireland using an integrated radon potential mapping method based on indoor radon measurements and geology that was originally developed for mapping radon potential in England and Wales. A refinement of this method was also investigated using linear regression analysis of a selection of relevant airborne and soil geochemical parameters from the Tellus Project. The most significant independent variables were found to be eU, a parameter derived from airborne gamma spectrometry measurements of radon decay products in the top layer of soil and exposed bedrock, and the permeability of the ground. The radon potential map generated from the Tellus data agrees in many respects with the map based on indoor radon data and geology but there are several areas where radon potential predicted from the airborne radiometric and permeability data is substantially lower. This under-prediction could be caused by the radon concentration being lower in the top 30 cm of the soil than at greater depth, because of the loss of radon from the surface rocks and soils to air. Copyright © 2011. Published by Elsevier B.V.

  7. Procedure for the characterization of radon potential in existing dwellings and to assess the annual average indoor radon concentration.

    Science.gov (United States)

    Collignan, Bernard; Powaga, Emilie

    2014-11-01

    Risk assessment due to radon exposure indoors is based on annual average indoor radon activity concentration. To assess the radon exposure in a building, measurement is generally performed during at least two months during heating period in order to be representative of the annual average value. This is because radon presence indoors could be very variable during time. This measurement protocol is fairly reliable but may be a limiting in the radon risk management, particularly during a real estate transaction due to the duration of the measurement and the limitation of the measurement period. A previous field study defined a rapid methodology to characterize radon entry in dwellings. The objective of this study was at first, to test this methodology in various dwellings to assess its relevance with a daily test. At second, a ventilation model was used to assess numerically the air renewal of a building, the indoor air quality all along the year and the annual average indoor radon activity concentration, based on local meteorological conditions, some building characteristics and in-situ characterization of indoor pollutant emission laws. Experimental results obtained on thirteen individual dwellings showed that it is generally possible to obtain a representative characterization of radon entry into homes. It was also possible to refine the methodology defined in the previous study. In addition, numerical assessments of annual average indoor radon activity concentration showed generally a good agreement with measured values. These results are encouraging to allow a procedure with a short measurement time to be used to characterize long-term radon potential in dwellings.

  8. Radon as a natural tracer for underwater cave exploration.

    Science.gov (United States)

    Csondor, Katalin; Erőss, Anita; Horváth, Ákos; Szieberth, Dénes

    2017-07-01

    The Molnár János cave is one of the largest hypogenic caves of the Buda Thermal Karst (Budapest, Hungary) and mainly characterized by water-filled passages. The major outflow point of the waters of the cave system is the Boltív spring, which feeds the artificial Malom Lake. Previous radon measurements in the cave system and in the spring established the highest radon concentration (71 BqL(-1)) in the springwater. According to previous studies, the origin of radon was identified as iron-hydroxide containing biofilms, which form where there is mixing of cold and thermal waters, and these biofilms efficiently adsorb radium from the thermal water component. Since mixing of waters is responsible for the formation of the cave as well, these iron-hydroxide containing biofilms and the consequent high radon concentrations mark the active cave forming zones. Based on previous radon measurements, it is supposed that the active mixing and cave forming zone has to be close to the spring, since the highest radon concentration was measured there. Therefore radon mapping was carried out with the help of divers in order to get a spatial distribution of radon in the cave passages closest to the spring. Based on our measurements, the highest radon activity concentration (84 BqL(-1)) was found in the springwater. Based on the distribution of radon activity concentrations, direct connection was established between the spring and the István-room of the cave, which was verified by an artificial tracer. However, the distribution of radon in the cave passages shows lower concentrations (18-46 BqL(-1)) compared to the spring, therefore an additional deep inflow from hitherto unknown cave passages is assumed, from which waters with high radon content arrive to the spring. These passages are assumed to be in the active cave formation zone. This study proved that radon activity concentration distribution is a useful tool in underwater cave exploration. Copyright © 2016 Elsevier Ltd. All

  9. Collaborative Hierarchical Sparse Modeling

    CERN Document Server

    Sprechmann, Pablo; Sapiro, Guillermo; Eldar, Yonina C

    2010-01-01

    Sparse modeling is a powerful framework for data analysis and processing. Traditionally, encoding in this framework is done by solving an l_1-regularized linear regression problem, usually called Lasso. In this work we first combine the sparsity-inducing property of the Lasso model, at the individual feature level, with the block-sparsity property of the group Lasso model, where sparse groups of features are jointly encoded, obtaining a sparsity pattern hierarchically structured. This results in the hierarchical Lasso, which shows important practical modeling advantages. We then extend this approach to the collaborative case, where a set of simultaneously coded signals share the same sparsity pattern at the higher (group) level but not necessarily at the lower one. Signals then share the same active groups, or classes, but not necessarily the same active set. This is very well suited for applications such as source separation. An efficient optimization procedure, which guarantees convergence to the global opt...

  10. Hierarchical manifold learning.

    Science.gov (United States)

    Bhatia, Kanwal K; Rao, Anil; Price, Anthony N; Wolz, Robin; Hajnal, Jo; Rueckert, Daniel

    2012-01-01

    We present a novel method of hierarchical manifold learning which aims to automatically discover regional variations within images. This involves constructing manifolds in a hierarchy of image patches of increasing granularity, while ensuring consistency between hierarchy levels. We demonstrate its utility in two very different settings: (1) to learn the regional correlations in motion within a sequence of time-resolved images of the thoracic cavity; (2) to find discriminative regions of 3D brain images in the classification of neurodegenerative disease,

  11. Performance analysis of a finite radon transform in OFDM system under different channel models

    Energy Technology Data Exchange (ETDEWEB)

    Dawood, Sameer A.; Anuar, M. S.; Fayadh, Rashid A. [School of Computer and Communication Engineering, Universiti Malaysia Perlis (UniMAP) Pauh Putra, 02000 Arau, Parlis (Malaysia); Malek, F.; Abdullah, Farrah Salwani [School of Electrical System Engineering, Universiti Malaysia Perlis (UniMAP) Pauh Putra, 02000 Arau, Parlis (Malaysia)

    2015-05-15

    In this paper, a class of discrete Radon transforms namely Finite Radon Transform (FRAT) was proposed as a modulation technique in the realization of Orthogonal Frequency Division Multiplexing (OFDM). The proposed FRAT operates as a data mapper in the OFDM transceiver instead of the conventional phase shift mapping and quadrature amplitude mapping that are usually used with the standard OFDM based on Fast Fourier Transform (FFT), by the way that ensure increasing the orthogonality of the system. The Fourier domain approach was found here to be the more suitable way for obtaining the forward and inverse FRAT. This structure resulted in a more suitable realization of conventional FFT- OFDM. It was shown that this application increases the orthogonality significantly in this case due to the use of Inverse Fast Fourier Transform (IFFT) twice, namely, in the data mapping and in the sub-carrier modulation also due to the use of an efficient algorithm in determining the FRAT coefficients called the optimal ordering method. The proposed approach was tested and compared with conventional OFDM, for additive white Gaussian noise (AWGN) channel, flat fading channel, and multi-path frequency selective fading channel. The obtained results showed that the proposed system has improved the bit error rate (BER) performance by reducing inter-symbol interference (ISI) and inter-carrier interference (ICI), comparing with conventional OFDM system.

  12. Torus Bifurcation Under Discretization

    Institute of Scientific and Technical Information of China (English)

    邹永魁; 黄明游

    2002-01-01

    Parameterized dynamical systems with a simple zero eigenvalue and a couple of purely imaginary eigenvalues are considered. It is proved that this type of eigen-structure leads to torns bifurcation under certain nondegenerate conditions. We show that the discrete systems, obtained by discretizing the ODEs using symmetric, eigen-structure preserving schemes, inherit the similar torus bifurcation properties. Fredholm theory in Banach spaces is applied to obtain the global torns bifurcation. Our results complement those on the study of discretization effects of global bifurcation.

  13. Discrete density of states

    Science.gov (United States)

    Aydin, Alhun; Sisman, Altug

    2016-03-01

    By considering the quantum-mechanically minimum allowable energy interval, we exactly count number of states (NOS) and introduce discrete density of states (DOS) concept for a particle in a box for various dimensions. Expressions for bounded and unbounded continua are analytically recovered from discrete ones. Even though substantial fluctuations prevail in discrete DOS, they're almost completely flattened out after summation or integration operation. It's seen that relative errors of analytical expressions of bounded/unbounded continua rapidly decrease for high NOS values (weak confinement or high energy conditions), while the proposed analytical expressions based on Weyl's conjecture always preserve their lower error characteristic.

  14. Hierarchically Structured Electrospun Fibers

    Directory of Open Access Journals (Sweden)

    Nicole E. Zander

    2013-01-01

    Full Text Available Traditional electrospun nanofibers have a myriad of applications ranging from scaffolds for tissue engineering to components of biosensors and energy harvesting devices. The generally smooth one-dimensional structure of the fibers has stood as a limitation to several interesting novel applications. Control of fiber diameter, porosity and collector geometry will be briefly discussed, as will more traditional methods for controlling fiber morphology and fiber mat architecture. The remainder of the review will focus on new techniques to prepare hierarchically structured fibers. Fibers with hierarchical primary structures—including helical, buckled, and beads-on-a-string fibers, as well as fibers with secondary structures, such as nanopores, nanopillars, nanorods, and internally structured fibers and their applications—will be discussed. These new materials with helical/buckled morphology are expected to possess unique optical and mechanical properties with possible applications for negative refractive index materials, highly stretchable/high-tensile-strength materials, and components in microelectromechanical devices. Core-shell type fibers enable a much wider variety of materials to be electrospun and are expected to be widely applied in the sensing, drug delivery/controlled release fields, and in the encapsulation of live cells for biological applications. Materials with a hierarchical secondary structure are expected to provide new superhydrophobic and self-cleaning materials.

  15. HDS: Hierarchical Data System

    Science.gov (United States)

    Pearce, Dave; Walter, Anton; Lupton, W. F.; Warren-Smith, Rodney F.; Lawden, Mike; McIlwrath, Brian; Peden, J. C. M.; Jenness, Tim; Draper, Peter W.

    2015-02-01

    The Hierarchical Data System (HDS) is a file-based hierarchical data system designed for the storage of a wide variety of information. It is particularly suited to the storage of large multi-dimensional arrays (with their ancillary data) where efficient access is needed. It is a key component of the Starlink software collection (ascl:1110.012) and is used by the Starlink N-Dimensional Data Format (NDF) library (ascl:1411.023). HDS organizes data into hierarchies, broadly similar to the directory structure of a hierarchical filing system, but contained within a single HDS container file. The structures stored in these files are self-describing and flexible; HDS supports modification and extension of structures previously created, as well as functions such as deletion, copying, and renaming. All information stored in HDS files is portable between the machines on which HDS is implemented. Thus, there are no format conversion problems when moving between machines. HDS can write files in a private binary format (version 4), or be layered on top of HDF5 (version 5).

  16. Hierarchical video summarization

    Science.gov (United States)

    Ratakonda, Krishna; Sezan, M. Ibrahim; Crinon, Regis J.

    1998-12-01

    We address the problem of key-frame summarization of vide in the absence of any a priori information about its content. This is a common problem that is encountered in home videos. We propose a hierarchical key-frame summarization algorithm where a coarse-to-fine key-frame summary is generated. A hierarchical key-frame summary facilitates multi-level browsing where the user can quickly discover the content of the video by accessing its coarsest but most compact summary and then view a desired segment of the video with increasingly more detail. At the finest level, the summary is generated on the basis of color features of video frames, using an extension of a recently proposed key-frame extraction algorithm. The finest level key-frames are recursively clustered using a novel pairwise K-means clustering approach with temporal consecutiveness constraint. We also address summarization of MPEG-2 compressed video without fully decoding the bitstream. We also propose efficient mechanisms that facilitate decoding the video when the hierarchical summary is utilized in browsing and playback of video segments starting at selected key-frames.

  17. Radon bad or good. One of the curiosity of the end of 20th century; Radon dobry czy zly, czyli jedna z osobliwosci konca XX wieku

    Energy Technology Data Exchange (ETDEWEB)

    Zagorski, Z.P. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1995-12-31

    The balneology of health resorts localized in radon rich regions of south-west Poland has been discussed. The historical evolution of the opinion about the influence of small radon doses to human health has been presented. 13 refs.

  18. Occurrence of radon in the Polish underground tourist routes

    Directory of Open Access Journals (Sweden)

    Jerzy Olszewski

    2015-08-01

    Full Text Available Background: There are about 200 underground tourist routes in Poland. There are caves, mines or underground structures. This paper presents the results of the research intended to identify the extent of the occurrence of radon concentrations in underground areas of tourist routes. Material and Methods: We conducted the measurement of periodic concentrations of radon (1–2 months in the summer using type Tastrak trace detectors. We determined the average concentrations of radon in air in 66 underground tourist routes in Poland. Results: The research results comprise 259 determinations of average radon concentrations in 66 routes. The arithmetic average of the results was 1610 Bqm–3, and the maximum measured concentration was over 20 000 Bqm–3. The minimum concentration was 100 Bqm–3 (threshold method considering the arithmetic average of the measurements. It was found that in 67% of the routes, the average concentration of radon has exceeded 300 Bqm–3 and in 22 underground routes it exceeded 1000 Bqm–3. Conclusions: Radon which occurs in many Polish underground tourist routes may be an organizational, legal and health problem. It is necessary to develop a program of measures to reduce radon concentrations in underground routes, especially routes located in the former mines. Med Pr 2015;66(4:557–563

  19. Radon Release and Its Simulated Effect on Radiation Doses.

    Science.gov (United States)

    Orabi, Momen

    2017-03-01

    One of the main factors that affect the uncertainty in calculating the gamma-radiation absorbed dose rate inside a room is the variation in the degree of secular equilibrium of the considered radioactive series. A component of this factor, considered in this paper, is the release of radon (Rn) from building materials to the living space of the room. This release takes place through different steps. These steps are represented and mathematically formulated. The diffusion of radon inside the material is described by Fick's second law. Some of the factors affecting the radon release rate (e.g. covering walls, moisture, structure of the building materials, etc.) are discussed. This scheme is used to study the impact of radon release on the gamma-radiation absorbed dose rate inside a room. The investigation is carried out by exploiting the MCNP simulation software. Different building materials are considered with different radon release rates. Special care is given to Rn due to its relatively higher half-life and higher indoor concentration than the other radon isotopes. The results of the presented model show that the radon release is of a significant impact in some building materials.

  20. Radon and COPD mortality in the American Cancer Society Cohort

    Science.gov (United States)

    Turner, Michelle C.; Krewski, Daniel; Chen, Yue; Pope, C. Arden; Gapstur, Susan M.; Thun, Michael J.

    2012-01-01

    Although radon gas is a known cause of lung cancer, the association between residential radon and mortality from non-malignant respiratory disease has not been well characterised. The Cancer Prevention Study-II is a large prospective cohort study of nearly 1.2 million Americans recruited in 1982. Mean county-level residential radon concentrations were linked to study participants' residential address based on their ZIP code at enrolment (mean±sd 53.5±38.0 Bq·m−3). Cox proportional hazards regression models were used to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI) for non-malignant respiratory disease mortality associated with radon concentrations. After necessary exclusions, a total of 811,961 participants in 2,754 counties were included in the analysis. Throughout 2006, there were a total of 28,300 non-malignant respiratory disease deaths. Radon was significantly associated with chronic obstructive pulmonary disease (COPD) mortality (HR per 100 Bq·m−3 1.13, 95% CI 1.05–1.21). There was a significant positive linear trend in COPD mortality with increasing categories of radon concentrations (pradon may increase COPD mortality. Further research is needed to confirm this finding and to better understand possible complex inter-relationships between radon, COPD and lung cancer. PMID:22005921

  1. A reconnaissance study of radon concentrations in Hamadan city, Iran

    Science.gov (United States)

    Gillmore, G. K.; Jabarivasal, N.

    2010-04-01

    This paper presents results of a reconnaissance study that used CR-39 alpha track-etch detectors to measure radon concentrations in dwellings in Hamadan, western Iran, significantly, built on permeable alluvial fan deposits. The indoor radon levels recorded varied from 4 (i.e. below the lower limit of detection for the method) to 364 Bq/m3 with a mean value of 108 Bq/m3 which is 2.5 times the average global population-weighted indoor radon concentration - these data augment the very few published studies on indoor radon levels in Iran. The maximum radon concentration in Hamadan occurs during the winter period (January to March) with lower concentrations during the autumn. The effective dose equivalent to the population in Hamadan is estimated from this study to be in the region of 2.7 mSv/y, which is above the guidelines for dose to a member of the public of 1 mSv/y suggested by the International Commission on Radiological Protection (ICRP) in 1993. This study supports other work in a number of countries that indicates such permeable "surficial" deposits as being of intermediate to high radon potential. In western Iran, the presence of hammered clay floors, the widespread presence of excavated qanats, the textural properties of surficial deposits and human behaviour intended to cope with winds are likely to be important factors influencing radon concentrations in older buildings.

  2. A reconnaissance study of radon concentrations in Hamadan city, Iran

    Directory of Open Access Journals (Sweden)

    G. K. Gillmore

    2010-04-01

    Full Text Available This paper presents results of a reconnaissance study that used CR-39 alpha track-etch detectors to measure radon concentrations in dwellings in Hamadan, western Iran, significantly, built on permeable alluvial fan deposits. The indoor radon levels recorded varied from 4 (i.e. below the lower limit of detection for the method to 364 Bq/m3 with a mean value of 108 Bq/m3 which is 2.5 times the average global population-weighted indoor radon concentration – these data augment the very few published studies on indoor radon levels in Iran. The maximum radon concentration in Hamadan occurs during the winter period (January to March with lower concentrations during the autumn. The effective dose equivalent to the population in Hamadan is estimated from this study to be in the region of 2.7 mSv/y, which is above the guidelines for dose to a member of the public of 1 mSv/y suggested by the International Commission on Radiological Protection (ICRP in 1993. This study supports other work in a number of countries that indicates such permeable "surficial" deposits as being of intermediate to high radon potential. In western Iran, the presence of hammered clay floors, the widespread presence of excavated qanats, the textural properties of surficial deposits and human behaviour intended to cope with winds are likely to be important factors influencing radon concentrations in older buildings.

  3. Long term performance of different radon remedial methods in Sweden

    CERN Document Server

    Clavensjoe, B

    2002-01-01

    The object of this project was to investigate the long time effectiveness of different radon remedial methods. The ten years project started 1991. From start the investigation comprised of 105 dwellings (91 single-family houses and 14 flats in multi-family buildings). In all of the dwellings remedial measures were carried out in the eighties. Before and immediately after the reduction the local measured the radon concentrations. New measurements of the radon concentrations have been made every third year; in 1991, 1994, 1997 and in 2000. Twelve different radon remedial methods and method combinations were used. The radon sources were building materials as well as sub-soils. In all of the dwellings the radon concentrations were measured by nuclear track films during 3 months (January-March) measurements and in half of them the air change rates by passive tracer gas methods. The results of the 2000 and the 1991 (within brackets) studies showed that the radon concentration was up to 200 Bq/m sup 3 in 54 (54) sin...

  4. The Pollino 2012 seismic sequence: clues from continuous radon monitoring

    Science.gov (United States)

    Piersanti, Antonio; Cannelli, Valentina; Galli, Gianfranco

    2016-09-01

    The 2012 Pollino (Calabria, Italy) seismic sequence, culminating in the Mw 5.2 earthquake of 25 October 2012, is investigated, exploiting data collected during a long-term continuous radon monitoring experiment performed in the epicentral area from late 2011 to the end of 2014. We analyse data collected both using a phenomenological approach based on quantitative evidence and a purely numerical analysis including the following: (i) correlation and cross-correlation investigations; (ii) an original approach aimed at limiting the impact of meteorological parameters variations on the interpretation of measured radon levels; (iii) a change point analysis; (iv) the implementation of an original detection algorithm aimed at highlighting the connections between radon emission variations and major seismic events occurrence. Results from both approaches suggest that radon monitoring stations can be subject to massive site effects, especially regarding rainfall, making data interpretation harder. The availability of long-term continuous measurements is crucial to precisely assess those effects. Nevertheless, statistical analysis shows a viable approach for quantitatively relating radon emanation variations to seismic energy release. Although much work is still needed to make radon time series analysis a robust complement to traditional seismological tools, this work has identified a characteristic variation in radon exhalation during the preparation process of large earthquakes.

  5. Soil-gas radon as seismotectonic indicator in Garhwal Himalaya

    Energy Technology Data Exchange (ETDEWEB)

    Ramola, R.C. [Department of Physics, H. N. B. Garhwal University, Badshahi Thaul Campus, Tehri Garhwal-249199 (India)], E-mail: rcramola@gmail.com; Prasad, Yogesh; Prasad, Ganesh [Department of Physics, H. N. B. Garhwal University, Badshahi Thaul Campus, Tehri Garhwal-249199 (India); Kumar, Sushil; Choubey, V.M. [Wadia Institute of Himalayan Geology, Dehradun-248001 (India)

    2008-10-15

    Research on earthquake-related radon monitoring has received enormous attention recently. Anomalous behaviour of radon in soil and groundwater can be used as a reliable precursor for an impending earthquake. While earthquake prediction may not yet be possible, earthquake prediction research has greatly increased our understanding of earthquake source mechanisms, the structural complexities of fault zones, and the earthquake recurrence interval, expected at a given location. This paper presents some results of continuous monitoring of radon in soil-gas in Garhwal Himalaya, India. Daily soil-gas radon monitoring with seismic activity and meteorological parameters were performed in the same laboratory system, located at H.N.B. Garhwal University Campus, Tehri Garhwal, India. Radon anomalies along with meteorological parameters were found to be statistically significant for the seismic events within the magnitudes M2.0-M6.0 and epicentral distances of 16-250 km from the monitoring station. The frequent positive and negative anomalies with constant environmental perturbation indicate the opening and closing of micro cracks within the volume of dilatancy by strain energy. The spike-like and sharp peak anomalies were recorded before, during and after earthquakes occurred in the area. The variations in radon concentrations in soil-gas are found to be correlated with seismic activities in the Garhwal Himalaya. The correlation between radon level and meteorological parameters is also discussed.

  6. Radon transport in fractured soil. Laboratory experiments and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Hoff, A.

    1997-10-01

    Radon (Rn-222) transport in fractured soil has been investigated by laboratory experiments and by modelling. Radon transport experiments have been performed with two sand columns (homogeneous and inhomogeneous) and one undisturbed clayey till column containing a net of preferential flow paths (root holes). A numerical model (the finite-element model FRACTRAN) and an analytic model (a pinhole model) have been applied in simulations if soil gas and radon transport in fractured soil. Experiments and model calculations are included in a discussion of radon entry rates into houses placed on fractured soil. The main conclusion is, that fractures does not in general alter transport of internally generated radon out of soil, when the pressure and flow conditions in the soil is comparable to the conditions prevailing under a house. This indicates the important result, that fractures in soil have no impact on radon entry into a house beyond that of an increased gas permeability, but a more thorough investigation of this subject is needed. Only in the case where the soil is exposed to large pressure gradients, relative to gradients induced by a house, may it be possible to observe effects of radon exchange between fractures and matrix. (au) 52 tabs., 60 ill., 5 refs.

  7. Soil-gas radon as seismotectonic indicator in Garhwal Himalaya.

    Science.gov (United States)

    Ramola, R C; Prasad, Yogesh; Prasad, Ganesh; Kumar, Sushil; Choubey, V M

    2008-10-01

    Research on earthquake-related radon monitoring has received enormous attention recently. Anomalous behaviour of radon in soil and groundwater can be used as a reliable precursor for an impending earthquake. While earthquake prediction may not yet be possible, earthquake prediction research has greatly increased our understanding of earthquake source mechanisms, the structural complexities of fault zones, and the earthquake recurrence interval, expected at a given location. This paper presents some results of continuous monitoring of radon in soil-gas in Garhwal Himalaya, India. Daily soil-gas radon monitoring with seismic activity and meteorological parameters were performed in the same laboratory system, located at H.N.B. Garhwal University Campus, Tehri Garhwal, India. Radon anomalies along with meteorological parameters were found to be statistically significant for the seismic events within the magnitudes M2.0-M6.0 and epicentral distances of 16-250 km from the monitoring station. The frequent positive and negative anomalies with constant environmental perturbation indicate the opening and closing of micro cracks within the volume of dilatancy by strain energy. The spike-like and sharp peak anomalies were recorded before, during and after earthquakes occurred in the area. The variations in radon concentrations in soil-gas are found to be correlated with seismic activities in the Garhwal Himalaya. The correlation between radon level and meteorological parameters is also discussed.

  8. Radon emanation from low-grade uranium ore.

    Science.gov (United States)

    Sahu, Patitapaban; Mishra, Devi Prasad; Panigrahi, Durga Charan; Jha, Vivekanand; Patnaik, R Lokeswara

    2013-12-01

    Estimation of radon emanation in uranium mines is given top priority to minimize the risk of inhalation exposure due to short-lived radon progeny. This paper describes the radon emanation studies conducted in the laboratory as well as inside an operating underground uranium mine at Jaduguda, India. Some of the important parameters, such as grade/(226)Ra activity, moisture content, bulk density, porosity and emanation fraction of ore, governing the migration of radon through the ore were determined. Emanation from the ore samples in terms of emanation rate and emanation fraction was measured in the laboratory under airtight condition in glass jar. The in situ radon emanation rate inside the mine was measured from drill holes made in the ore body. The in situ(222)Rn emanation rate from the mine walls varied in the range of 0.22-51.84 × 10(-3) Bq m(-2) s(-1) with the geometric mean of 8.68 × 10(-3) Bq m(-2) s(-1). A significant positive linear correlation (r = 0.99, p 222)Rn emanation rate and the ore grade was observed. The emanation fraction of the ore samples, which varied in the range of 0.004-0.089 with mean value of 0.025 ± 0.02, showed poor correlation with ore grade and porosity. Empirical relationships between radon emanation rate and the ore grade/(226)Ra were also established for quick prediction of radon emanation rate from the ore body.

  9. Radon and thoron concentrations in public workplaces in Brisbane, Australia.

    Science.gov (United States)

    Alharbi, Sami H; Akber, Riaz A

    2015-06-01

    Radon and thoron are radioactive gases that can emanate from soil and building materials, and it can accumulate in indoor environments. The concentrations of radon and thoron in the air from various workplace categories in Brisbane, Australia were measured using an active method. The average radon and thoron concentrations for all workplace categories were 10.5 ± 11.3 and 8.2 ± 1.4 Bq m(-3), respectively. The highest radon concentration was detected in a confined area, 86.6 ± 6.0 Bq m(-3), while the maximum thoron level was found in a storage room, 78.1 ± 14.0 Bq m(-3). At each site, the concentrations of radon and thoron were measured at two heights, 5 cm and 120 cm above the floor. The effect of the measurement heights on the concentration level was significant in the case of thoron. The monitoring of radon and thoron concentrations showed a lower radon concentration during work hours than at other times of the day. This can be attributed to the ventilation systems, including the air conditioner and natural ventilation, which normally operate during work hours. The diurnal variation was less observed in the case of thoron, as the change in its concentration during and after the working hours was insignificant. The study also investigated the influence of the floor level and flooring type on indoor radon and thoron concentrations. The elevated levels of radon and thoron were largely found in basements and ground floor levels and in rooms with concrete flooring.

  10. RESIDENTIAL RADON AND BIRTH DEFECTS: A POPULATION-BASED ASSESSMENT

    Science.gov (United States)

    Langlois, Peter H; Lee, MinJae; Lupo, Philip J; Rahbar, Mohammad H; Cortez, Ruben K

    2015-01-01

    BACKGROUND Associations have been reported between maternal radiation exposure and birth defects. No such studies were found on radon. Our objective was to determine if there is an association between living in areas with higher radon levels and birth defects. METHODS The Texas Birth Defects Registry provided data on all birth defects from 1999–2009 from the entire state. Mean radon levels by geologic region came from the Texas Indoor Radon Survey. The association between radon and birth defects was estimated using multilevel mixed effect Poisson regression. RESULTS Birth defects overall were not associated with residential radon levels. Of the 100 other birth defect groups with at least 500 cases, 14 were significantly elevated in areas with high mean radon level in crude analyses, and 9 after adjustment for confounders. Cleft lip with/without cleft palate had an adjusted prevalence ratio (aPR) of 1.16 per 1 picoCurie/liter (pCi/l) increase in exposure to region mean radon, 95% confidence interval (CI) 1.08, 1.26. Cystic hygroma / lymphangioma had an aPR of 1.22 per 1 pCi/l increase, 95% CI 1.02, 1.46. Other associations were suggested but not as consistent: three skeletal defects, Down syndrome, other specified anomalies of the brain, and other specified anomalies of the bladder and urethra. CONCLUSIONS In the first study of residential radon and birth defects, we found associations with cleft lip w/wo cleft palate and cystic hygroma / lymphangioma. Other associations were suggested. The ecological nature of this study and multiple comparisons suggest that our results be interpreted with caution. PMID:25846606

  11. Radon emanation from backfilled mill tailings in underground uranium mine.

    Science.gov (United States)

    Sahu, Patitapaban; Mishra, Devi Prasad; Panigrahi, Durga Charan; Jha, Vivekananda; Patnaik, R Lokeswara; Sethy, Narendra Kumar

    2014-04-01

    Coarser mill tailings used as backfill to stabilize the stoped out areas in underground uranium mines is a potential source of radon contamination. This paper presents the quantitative assessment of radon emanation from the backfilled tailings in Jaduguda mine, India using a cylindrical accumulator. Some of the important parameters such as (226)Ra activity concentration, bulk density, bulk porosity, moisture content and radon emanation factor of the tailings affecting radon emanation were determined in the laboratory. The study revealed that the radon emanation rate of the tailings varied in the range of 0.12-7.03 Bq m(-2) s(-1) with geometric mean of 1.01 Bq m(-2) s(-1) and geometric standard deviation of 3.39. An increase in radon emanation rate was noticed up to a moisture saturation of 0.09 in the tailings, after which the emanation rate gradually started declining with saturation due to low diffusion coefficient of radon in the saturated tailings. Radon emanation factor of the tailings varied in the range of 0.08-0.23 with the mean value of 0.21. The emanation factor of the tailings with moisture saturation level over 0.09 was found to be about three times higher than that of the absolutely dry tailings. The empirical relationship obtained between (222)Rn emanation rate and (226)Ra activity concentration of the tailings indicated a significant positive linear correlation (r = 0.95, p < 0.001). This relationship may be useful for quick prediction of radon emanation rate from the backfill material of similar nature. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Radon concentrations in different types of dwellings in Israel.

    Science.gov (United States)

    Epstein, L; Koch, J; Riemer, T; Orion, I; Haquin, G

    2014-12-01

    The average radon concentration in Israeli dwellings was assessed by combining the results of a 2006 radon survey in single-family houses with the results of a 2011 radon survey in apartments of multistorey buildings. Both surveys were based on long-term measurements using CR-39 detectors. The survey in multistorey buildings was intended to assess the influence of recent practices in the local building industry on the radon concentrations. These practices include the use of building materials with higher concentrations of the natural radionuclides in the last 20 y than before, as well as the improvement in sealing techniques over that period. Another practice in place since the early 1990 s is the building of a shielded area in every apartment that is known as an RSS (residential secure space). The RSS is a room built from massive concrete walls, floor and ceiling that can be hermetically sealed and is intended to protect its residents from a missile attack. The influence of the above-mentioned features on radon concentrations was estimated by dividing the participating apartments into two groups: apartments in buildings >20 y, built using building materials with low concentrations of the natural radionuclides, regular sealing and without an RSS and apartments in buildings newer than 10 y, built using building materials with higher concentrations of the natural radionuclides, improved sealing and including an RSS. It was found that the average radon concentration in apartments in new buildings was significantly higher than in old buildings and the average radon concentration in single-family houses was significantly higher than in apartments in multistorey buildings. Doses due to indoor radon were estimated on the basis of the updated information included in the 2009 International Commission on Radiological Protection statement on radon.

  13. Residential radon and brain tumour incidence in a Danish cohort.

    Directory of Open Access Journals (Sweden)

    Elvira V Bräuner

    Full Text Available BACKGROUND: Increased brain tumour incidence over recent decades may reflect improved diagnostic methods and clinical practice, but remain unexplained. Although estimated doses are low a relationship between radon and brain tumours may exist. OBJECTIVE: To investigate the long-term effect of exposure to residential radon on the risk of primary brain tumour in a prospective Danish cohort. METHODS: During 1993-1997 we recruited 57,053 persons. We followed each cohort member for cancer occurrence from enrolment until 31 December 2009, identifying 121 primary brain tumour cases. We traced residential addresses from 1 January 1971 until 31 December 2009 and calculated radon concentrations at each address using information from central databases regarding geology and house construction. Cox proportional hazards models were used to estimate incidence rate-ratios (IRR and 95% confidence intervals (CI for the risk of primary brain tumours associated with residential radon exposure with adjustment for age, sex, occupation, fruit and vegetable consumption and traffic-related air pollution. Effect modification by air pollution was assessed. RESULTS: Median estimated radon was 40.5 Bq/m(3. The adjusted IRR for primary brain tumour associated with each 100 Bq/m(3 increment in average residential radon levels was 1.96 (95% CI: 1.07; 3.58 and this was exposure-dependently higher over the four radon exposure quartiles. This association was not modified by air pollution. CONCLUSIONS: We found significant associations and exposure-response patterns between long-term residential radon exposure radon in a general population and risk of primary brain tumours, adding new knowledge to this field. This finding could be chance and needs to be challenged in future studies.

  14. Radon-222 in the ground water of Chester County, Pennsylvania

    Science.gov (United States)

    Senior, Lisa A.

    1998-01-01

    Radon-222 concentrations in ground water in 31 geologic units in Chester County, Pa., were measured in 665 samples collected from 534 wells from 1986 to 1997. Chester County is underlain by schists, gneisses, quartzites, carbonates, sandstones, shales, and other rocks of the Piedmont Physiographic Province. On average, radon concentration was measured in water from one well per 1.4 square miles, throughout the 759 square-mile county, although the distribution of wells was not even areally or among geologic units. The median concentration of radon-222 in ground water from the 534 wells was 1,400 pCi/L (picocuries per liter). About 89 percent of the wells sampled contained radon-222 at concentrations greater than 300 pCi/L, and about 11 percent of the wells sampled contained radon-222 at concentrations greater than 5,000 pCi/L. The highest concentration measured was 53,000 pCi/L. Of the geologic units sampled, the median radon-222 concentration in ground water was greatest (4,400 pCi/L) in the Peters Creek Schist, the second most areally extensive formation in the county. Signifi- cant differences in the radon-222 concentrations in ground water among geologic units were observed. Generally, concentrations in ground water in schists, quartzites, and gneisses were greater than in ground water in anorthosite, carbonates, and ultramafic rocks. The distribution of radon-222 in ground water is related to the distribution of uranium in aquifer materials of the various rock types. Temporal variability in radon-222 concentrations in ground water does not appear to be greater than about a factor of two for most (75 percent) of wells sampled more than once but was observed to range up to almost a factor of three in water from one well. In water samples from this well, seasonal variations were observed; the maximum concentrations were measured in the fall and the minimum in the spring.

  15. Pearls of Discrete Mathematics

    CERN Document Server

    Erickson, Martin

    2009-01-01

    Presents methods for solving counting problems and other types of problems that involve discrete structures. This work illustrates the relationship of these structures to algebra, geometry, number theory and combinatorics. It addresses topics such as information and game theories

  16. Discrete fractional calculus

    CERN Document Server

    Goodrich, Christopher

    2015-01-01

    This text provides the first comprehensive treatment of the discrete fractional calculus. Experienced researchers will find the text useful as a reference for discrete fractional calculus and topics of current interest. Students who are interested in learning about discrete fractional calculus will find this text to provide a useful starting point. Several exercises are offered at the end of each chapter and select answers have been provided at the end of the book. The presentation of the content is designed to give ample flexibility for potential use in a myriad of courses and for independent study. The novel approach taken by the authors includes a simultaneous treatment of the fractional- and integer-order difference calculus (on a variety of time scales, including both the usual forward and backwards difference operators). The reader will acquire a solid foundation in the classical topics of the discrete calculus while being introduced to exciting recent developments, bringing them to the frontiers of the...

  17. The Discrete Wavelet Transform

    Science.gov (United States)

    1991-06-01

    focuses on bringing together two separately motivated implementations of the wavelet transform , the algorithm a trous and Mallat’s multiresolution...decomposition. These algorithms are special cases of a single filter bank structure, the discrete wavelet transform , the behavior of which is governed by...nonorthogonal multiresolution algorithm for which the discrete wavelet transform is exact. Moreover, we show that the commonly used Lagrange a trous

  18. Discrete computational structures

    CERN Document Server

    Korfhage, Robert R

    1974-01-01

    Discrete Computational Structures describes discrete mathematical concepts that are important to computing, covering necessary mathematical fundamentals, computer representation of sets, graph theory, storage minimization, and bandwidth. The book also explains conceptual framework (Gorn trees, searching, subroutines) and directed graphs (flowcharts, critical paths, information network). The text discusses algebra particularly as it applies to concentrates on semigroups, groups, lattices, propositional calculus, including a new tabular method of Boolean function minimization. The text emphasize

  19. Radon gas monitoring survey for the determination of Radon Prone Areas in Lombardia

    Energy Technology Data Exchange (ETDEWEB)

    Bartolo, D. de; Alberici, A.; Gallini, R.; Maggioni, T.; Mondini, A.; Zini, E. [A.R.P.A. della Lombardia, Milano (Italy); Arrigoni, S.; Cazzaniga, P.; Cugini, A.; Gallinari, G.; Olivieri, F.; Romanelli, M. [A.R.P.A. della Lombardia, Dipt. di Bergamo, Bergamo (Italy)

    2006-07-01

    Region Lombardia has carried out a radon gas monitoring survey on its territory to localize radon prone areas as by law 241/00 enacted. To plan the survey, the Lombardia territory has been divided into two different types according to the morphology as well as the presence of a substratum of rock. The area with hills and mountains has been investigated with more attention compared to the plain because we can assume higher variability in radon concentration distribution due to the geological and morphological characteristics. The territory subdivision was based on the standard grid.. of the techniregional cartography (8 x 5 km). To perform radon indoor concentration measurements about 3600 measuring points were selected. They are located at the ground floor of buildings with the characteristics to ensure the tests are representative and comparable. It has also been taken into account evaluations done with previous surveys in accordance with the defined specification of the sites. The measurements were carried out using C.R. 39 trace detector technique. The detectors were contained in closed plastic canisters and they were positioned in situ for one year and measured each semester. The detectors were chemically treated and the traces counted using the automated optical system installed at the Radiometric Laboratory of the A.R.P.A. Department in Bergamo. The instrument accuracy and precision were evaluated using data obtained with different methods: using detectors exposed to radon known concentrations, participating to an international intercomparison as well as exposing the detector in a national calibration centre. Due to the large amount of detectors involved, a particular attention was taken for the detector homogeneity response and for the optimization of the analysis parameters. For further investigating the reliability of the measurements, two detectors were used in parallel in 10% of the tests. The results show higher values in the areas of Bergamo, Brescia

  20. United role of radon decay products and nano-aerosols in radon dosimetry

    Science.gov (United States)

    Smerajec, M.; Vaupotič, J.

    2012-04-01

    The major part of human exposure to natural radiation originates from inhalation of radon (Rn) and radon short-lived decay products (RnDP: 218Po, 214Pb, 214Bi and 214Po). RnDP are formed as a result of α-transformation of radon. In the beginning they are positive ions which neutralize and form clusters with air molecules, and later partly attach to background aerosol particles in indoor air. Eventually, they appear as radioactive nano-aerosols with a bimodal size distribution in ranges of 1-10 nm (unattached RnDP) and of 200-800 nm (attached RnDP). When inhaled, they are deposited in the respiratory tract. Deposition is more efficient for smaller particles. Therefore, the fraction (fun) of the unattached RnDP, which appears to be influenced by the number concentration and size distribution of general (background) aerosols in the ambient air, has a crucial role in radon dosimetry. Radon, radon decay products and general aerosols have been monitored simultaneously in the kitchen of a typical rural house under real living conditions, also comprising four human activities generating particular matter: cooking and baking, as two typical activities in kitchen, and cigarette smoking and candle burning. In periods without any human activity, the total number concentration of general aerosol ranged from 1000 to 3000 cm-3,with the geometric mean of particle diameter in the range of 60-68 nm and with 0.1-1 % of particles smaller than 10 nm. Preparation of coffee changed the concentration to 193,000 cm-3, the geometric mean of diameter to 20 nm and fraction of particles smaller than 10 nm to 11 %. The respective changes were for baking cake: 503,000 cm-3, 17 nm and 19 %, for smoking:423,000 cm-3, 83 nm and 0.4 %, and forcandle burning: 945,000 cm-3, 8 nm and 85 %. While, as expected, a reduction of fun was observed during cooking, baking and smoking, when larger particles were emitted, fun did not increase during candle burning with mostly particles smaller than 10 nm

  1. A brief overview on radon measurements in drinking water.

    Science.gov (United States)

    Jobbágy, Viktor; Altzitzoglou, Timotheos; Malo, Petya; Tanner, Vesa; Hult, Mikael

    2017-07-01

    The aim of this paper is to present information about currently used standard and routine methods for radon analysis in drinking waters. An overview is given about the current situation and the performance of different measurement methods based on literature data. The following parameters are compared and discussed: initial sample volume and sample preparation, detection systems, minimum detectable activity, counting efficiency, interferences, measurement uncertainty, sample capacity and overall turnaround time. Moreover, the parametric levels for radon in drinking water from the different legislations and directives/guidelines on radon are presented. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Radon-safe building in Finland; Radonturvallinen rakentaminen Suomessa

    Energy Technology Data Exchange (ETDEWEB)

    Ravea, T.; Arvela, H.

    1997-05-01

    The study concentrates on radon-safe building in Finnish low-rise residential buildings. The data regarding the preventive measures taken in 300 dwellings was obtained from a questionnaire study. The study also aims at finding the main defects in design and implementation and how the guidance given on radon-safe building has been followed. A reference value was estimated for each of the houses on the basis of former local indoor radon measurements in houses with no preventive measures. Geological and building aspects were considered when estimating the reference values. (12 refs.).

  3. Calculation of radon concentration in water by toluene extraction method

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Masaaki [Tokyo Metropolitan Isotope Research Center (Japan)

    1997-02-01

    Noguchi method and Horiuchi method have been used as the calculation method of radon concentration in water. Both methods have two problems in the original, that is, the concentration calculated is changed by the extraction temperature depend on the incorrect solubility data and the concentration calculated are smaller than the correct values, because the radon calculation equation does not true to the gas-liquid equilibrium theory. However, the two problems are solved by improving the radon equation. I presented the Noguchi-Saito equation and the constant B of Horiuchi-Saito equation. The calculating results by the improved method showed about 10% of error. (S.Y.)

  4. Design Criteria for Achieving Acceptable Indoor Radon Concentration

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2016-01-01

    Design criteria for achieving an acceptable indoor radon concentration are presented in this paper. The paper suggests three design criteria. These criteria have to be considered at the early stage of the building design phase to meet the latest recommendations from the World Health Organization...... from the ground, and the third criteria can dilute the indoor air. By combining these three criteria, the indoor radon concentration can be lowered achieving an acceptable level. In addition, a cheap and reliable method for measuring the radon concentration in the indoor air is described. The provision...

  5. Radon depletion in xenon boil-off gas

    OpenAIRE

    Bruenner, S.; Cichon, D.; Lindemann, S.; Undagoitia, T. Marrodán; Simgen, H.

    2016-01-01

    An important background in detectors using liquid xenon for rare event searches arises from the decays of radon and its daughters. We report for the first time a reduction of $^{222}$Rn in the gas phase above a liquid xenon reservoir. We show a reduction factor of $\\gtrsim 4$ for the $^{222}$Rn concentration in boil-off xenon gas compared to the radon enriched liquid phase. A semiconductor-based $\\alpha$-detector and miniaturized proportional counters are used to detect the radon. As the rado...

  6. Measurements of radon in dwellings with CR-39 track detectors

    DEFF Research Database (Denmark)

    Majborn, Benny

    1986-01-01

    A passive integrating dosemeter has been designed for measuring natural radiation in dwellings. The dosemeter contains one or two CR-39 track detectors to measure radon and three thermoluminescence dosemeters to measure external radiation. The dosemeter was investigated in a pilot study in 1983....../84, and it is now used in a nationwide survey of natural radiation in Danish dwellings. The characteristics of the dosemeter with respect to radon measurements are presented, and the radon monitoring results obtained in the pilot study are summarized...

  7. A study of indoor radon levels and radon effective dose in dwellings of some cities of Gezira State in Sudan

    Directory of Open Access Journals (Sweden)

    Elzain Abd-Elmoniem Ahmed

    2014-01-01

    Full Text Available Exposure to natural sources of radiation, especially 222Rn and its short-lived daughter products has become an important issue throughout the world because sustained exposure of humans to indoor radon may cause lung cancer. The indoor radon concentration level and radon effective dose rate were carried out in the dwellings of Medani, El Hosh, Elmanagil, Haj Abd Allah, and Wad Almahi cities, Gezira State - Central Sudan, in 393 measurements, using passive integrated solid-state nuclear track devices containing allyl diglycol carbonate plastic detectors. The radon concentration in the corresponding dwellings was found to vary from (57 ± 8 Bq/m3 in Medani to 41 ± 9 Bq/m3 in Wad Almahi, with an average of 49 ± 10 Bq/m3. Assuming an indoor occupancy factor of 0.8 and 0.4 for the equilibrium factor of radon indoors, we found that the annual effective dose rate from 222Rn in the studied dwellings ranges from 1.05 to 1.43 mSv per year and the relative lung cancer risk for radon exposure was 1.044%. In this research, we also correlated the relationship of radon concentration and building age. From our study, it is clear that the annual effective dose rate is larger than the “normal” background level as quoted by UNSCEAR, lower than the recommended action level of ICRP, and less than the maximum permissible dose defined by the International Atomic Energy Agency.

  8. Soil features and indoor radon concentration prediction: radon in soil gas, pedology, permeability and 226Ra content.

    Science.gov (United States)

    Lara, E; Rocha, Z; Santos, T O; Rios, F J; Oliveira, A H

    2015-11-01

    This work aims at relating some physicochemical features of soils and their use as a tool for prediction of indoor radon concentrations of the Metropolitan Region of Belo Horizonte (RMBH), Minas Gerais, Brazil. The measurements of soil gas radon concentrations were performed by using an AlphaGUARD monitor. The (226)Ra content analysis was performed by gamma spectrometry (high pure germanium) and permeabilities were performed by using the RADON-JOK permeameter. The GEORP indicator and soil radon index (RI) were also calculated. Approximately 53 % of the Perferric Red Latosols measurement site could be classified as 'high risk' (Swedish criteria). The Litholic Neosols presented the lowest radon concentration mean in soil gas. The Perferric Red Latosols presented significantly high radon concentration mean in soil gas (60.6 ± 8.7 kBq m(-3)), high indoor radon concentration, high RI, (226)Ra content and GEORP. The preliminary results may indicate an influence of iron formations present very close to the Perferric Red Latosols in the retention of uranium minerals.

  9. Standardised Radon Index (SRI: a normalisation of radon data-sets in terms of standard normal variables

    Directory of Open Access Journals (Sweden)

    R. G. M. Crockett

    2011-07-01

    Full Text Available During the second half of 2002, from late June to mid December, the University of Northampton Radon Research Group operated two continuous hourly-sampling radon detectors 2.25 km apart in the English East Midlands. This period included the Dudley earthquake (ML = 5, 22 September 2002 and also a smaller earthquake in the English Channel (ML = 3, 26 August 2002. Rolling/sliding windowed cross-correlation of the paired radon time-series revealed periods of simultaneous similar radon anomalies which occurred at the time of these earthquakes but at no other times during the overall radon monitoring period. Standardising the radon data in terms of probability of magnitude, analogous to the Standardised Precipitation Indices (SPIs used in drought modelling, which effectively equalises different non-linear responses, reveals that the dissimilar relative magnitudes of the anomalies are in fact closely equiprobabilistic. Such methods could help in identifying anomalous signals in radon – and other – time-series and in evaluating their statistical significance in terms of earthquake precursory behaviour.

  10. SWOT analysis of the Czech Radon programme.

    Science.gov (United States)

    Fojtíková, I

    2014-07-01

    Since the early 1990s, the Czech Republic has been one of the countries that carry out a radon programme on its territory, with the aim of protecting people from unnecessary long-term exposure in their homes. Since that time, many achievements have been registered, and many unexpected difficulties have cropped up. This may be the right moment to take some time out to analyse the state of the programme and to determine the direction for its future development. An extended SWOT analysis can serve as a useful tool for this purpose. Originally, SWOT analyses were used exclusively by for-profit organisations aiming to evaluate their perspectives, develop strategies and make plans in order to achieve their objectives. More recently, it has been used in a wide range of decision-making situations when a desired end-state is to be defined. Here, an extended SWOT analysis is used to formulate possible beneficial strategies for advancing anti-radon policy in the Czech Republic.

  11. Environmental gamma and radon dosimetry in Venezuela

    CERN Document Server

    Sajo-Bohus, L; Urbani, F; Castro, D D; Greaves, E D; Liendo, J A

    1999-01-01

    Environmental gamma exposure and radon concentration levels measured in Venezuelan regions are presented. A new generation image analyser was used for alpha particle track counting in CR-39 detectors. Mineral water wells from where water is supplied for massive consumption have an alpha activity around 0.450 Bq L sup - sup 1 and few of them have concentrations above 50 Bq L sup - sup 1. Coastal potable water activity is on the average around 5.3 +- 12% Bq L sup - sup 1. Indoor radon national average is 36 +- 5% Bq m sup - sup 3; in two of the 36 monitored sites, the measured average is above 400 +- 5% Bq m sup - sup 3. In air gamma dose values are between 100 and 144 nGy h sup - sup 1. In soil, sup 1 sup 3 sup 7 Cs concentration is around 0.5 and 10 Bq kg sup - sup 1 at the depth of down to 20 cm. Building materials were included in this study. sup 7 Be and sup 1 sup 3 sup 7 Cs were measured in low concentration in tropical plants on Tepuy-s (sacred mountains in the Amazonas State). Geological active faults w...

  12. Pilot study of the application of Tellus airborne radiometric and soil geochemical data for radon mapping.

    Science.gov (United States)

    Appleton, J D; Miles, J C H; Green, B M R; Larmour, R

    2008-10-01

    The scope for using Tellus Project airborne gamma-ray spectrometer and soil geochemical data to predict the probability of houses in Northern Ireland having high indoor radon concentrations is evaluated, in a pilot study in the southeast of the province, by comparing these data statistically with in-house radon measurements. There is generally good agreement between radon maps modelled from the airborne radiometric and soil geochemical data using multivariate linear regression analysis and conventional radon maps which depend solely on geological and indoor radon data. The radon maps based on the Tellus Project data identify some additional areas where the radon risk appears to be relatively high compared with the conventional radon maps. One of the ways of validating radon maps modelled on the Tellus Project data will be to carry out additional indoor measurements in these areas.

  13. Radon dosimetry occupational safety in working area of Sanpaolo IMI organization; Individuazione e dosimetria del radon presso i presidi operativi del gruppo Sanpaolo IMI: parte 1

    Energy Technology Data Exchange (ETDEWEB)

    Scielzo, Giuseppe; Bresciani, Sara [ASO Ordine Mauriziano, Torino (Italy); Coggiola, Maurizio [Torino Univ., Torino (Italy). DTP Traumatologia, ortopedia e medicina del lavoro; Magnone, Maurizio; Chiaberto, Enrico [Arpa Piemonte, Torino (Italy)

    2005-05-15

    The Radon 222 is a natural radioactive gas present inside rocks, soil and building materials. Its decay produce ionizing Alpha radiation. The OMS Organization classified the Radon as cancerogenic substance of group 1 at most high cancerogenicity. In Italy the Radon risk is regulated in law 230 and its modifications.

  14. RADON MITIGATION IN SCHOOLS: HVAC SYTEMS IN SCHOOLS TEND TO HAVE A GREATER IMPACT ON RADON LEVELS THAN HVAC SYSTEMS IN HOMES

    Science.gov (United States)

    The first part of this two-part paper discusses radon entry into schools, radon mitigation approaches for schools, and school characteristics (e.g., heating, ventilation, and air conditioing -- HVAC-- system design and operationg) that influence radon entry and mitigation system ...

  15. RADON MITIGATION IN SCHOOLS: HVAC SYTEMS IN SCHOOLS TEND TO HAVE A GREATER IMPACT ON RADON LEVELS THAN HVAC SYSTEMS IN HOMES

    Science.gov (United States)

    The first part of this two-part paper discusses radon entry into schools, radon mitigation approaches for schools, and school characteristics (e.g., heating, ventilation, and air conditioing -- HVAC-- system design and operationg) that influence radon entry and mitigation system ...

  16. Anomalous indoor radon concentration in a dwelling in Qatif City, Saudi Arabia.

    Science.gov (United States)

    Al-Jarallah, M I; Fazal-ur-Rehman

    2005-01-01

    An indoor radon survey was carried out recently in nine cities of Saudi Arabia using nuclear track detectors (NTD)-based passive radon detectors. The survey included Qatif City in the Eastern Province of Saudi Arabia, where 225 detectors were collected back successfully. It was found that the average indoor radon concentration in the dwellings was 22 +/- 15 Bq m(-3). However, one of the dwellings showed an anomalous radon concentration of 535 +/- 23 Bq m(-3). This finding led to a detailed investigation of this dwelling using active and passive techniques. In the active technique, an AlphaGUARD 2000 PRQ radon gas analyser was used. In the passive technique, CR-39 based passive radon detectors were used in all the rooms of the dwelling. Radon exhalation from the wall and the floor was also measured using the can technique. The active measurement confirms the passive one. Before placing the passive radon detectors in all the rooms of the two-storey building, the inhabitant was advised to ventilate his house regularly. The radon concentration in the different rooms was found to vary from 124 to 302 Bq m(-3). Radon exhalation from the floor and the wall of the room with the anomalous radon concentration was found to vary from 0.5 to 0.8 Bq m(-2) h(-1). These low radon exhalation rates suggest that the anomalous radon concentration is most probably due to underground radon diffusion into the dwelling through cracks and joints in the concrete floor.

  17. Radon Testing for Safe Schools Act. Report (To Accompany S. 1697) from the Committee on Environment and Public Works, United States Senate, One Hundred First Congress, Second Session.

    Science.gov (United States)

    Congress of the U.S., Washington, DC. Senate Committee on Environment and Public Works.

    This report was written to accompany the Radon Testing for Safe Schools Act (S.1697), a bill that provides for radon testing of schools located in high risk radon areas and provides limited financial assistance to schools for mitigation of high levels of radon. A description of radon, its harmful effects, and the radon levels detected in schools…

  18. Hybrid discrete cosine transform-discrete wavelet transform for progressive image compression

    Science.gov (United States)

    Boukaache, Abdennour; Doghmane, Noureddine

    2012-01-01

    In this paper, we propose an image compression algorithm that uses a hybrid transform and an improved modified set partitioning in hierarchical trees (SPIHT) coding algorithm. The proposed transform uses the subband discrete cosine transform to decompose the image into multiresolution subbands where the discrete wavelet transform is then used to code the low frequencies. Then, we use the SPIHT coding method to code the transformed coefficients. For the SPIHT algorithm, we have proposed a method to reduce the distortion introduced by the SPIHT technique between the original and reconstructed images. The obtained results show the efficiency of the proposed hybrid method in terms of peak signal-to-noise ratio and visual quality.

  19. The origin of discrete symmetries in F-theory models

    OpenAIRE

    2015-01-01

    While non-abelian groups are undoubtedly the cornerstone of Grand Unified Theories (GUTs), phenomenology shows that the role of abelian and discrete symmetries is equally important in model building. The latter are the appropriate tool to suppress undesired proton decay operators and various flavour violating interactions, to generate a hierarchical fermion mass spectrum, etc. In F-theory, GUT symmetries are linked to the singularities of the elliptically fibred K3 manifolds; they are of ADE ...

  20. Determination of radon levels in Mexico City; Determinacion de niveles de radon en la Ciudad de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Pena G, P

    1992-01-15

    The study of the determination of radon levels in the houses room in Mexico City is part of the project Emanometry of the radon. To carry out this study, the passive method was used, which consists of: thin film dosemeter of cellulose nitrate, container of the same one and spark accountant. The method is based on the mensurations of exhibition of the number of marks of alpha track is of the open type and it allows to average the radon activity along several weeks and it presents low concentrations. This study was carried out in 4 periods of exhibition of 3 months each one. (Author)

  1. Radon and environmental radioactivity in the Canfranc Underground Laboratory; Radon y radiacion ambiental en el Laboratorio Subterraneo de Canfrac (LSC)

    Energy Technology Data Exchange (ETDEWEB)

    Bandac, I.; Bettini, A.; Borjabad, S.; Nunez-Lagos, R.; Perez, C.; Rodriguez, S.; Sanchez, P.; Villar, J. A.

    2014-02-01

    The results of more than one year of measurements of Radon and environmental radioactivity in the Canfranc Underground Laboratory (LSC) are presented. Radon and atmospheric parameters have registered by an Alpha guard P30 equipment and the environmental radioactivity has been measured by means of UD-802A Panasonic thermoluminescent dosimeters (TLD) processed by an UD716 Panasonic unit. Series of results along with their possible correlations are presented. Both the Radon level and the ambient dose equivalent H (10) are much lower than the allowed ones so no radiological risk exists to persons working in the LSC. Also its excellent environmental radiological quality has been confirmed. (Author)

  2. Correction factors for determination of annual average radon concentration in dwellings of Poland resulting from seasonal variability of indoor radon.

    Science.gov (United States)

    Kozak, K; Mazur, J; Kozłowska, B; Karpińska, M; Przylibski, T A; Mamont-Cieśla, K; Grządziel, D; Stawarz, O; Wysocka, M; Dorda, J; Zebrowski, A; Olszewski, J; Hovhannisyan, H; Dohojda, M; Kapała, J; Chmielewska, I; Kłos, B; Jankowski, J; Mnich, S; Kołodziej, R

    2011-10-01

    The method for the calculation of correction factors is presented, which can be used for the assessment of the mean annual radon concentration on the basis of 1-month or 3-month indoor measurements. Annual radon concentration is an essential value for the determination of the annual dose due to radon inhalation. The measurements have been carried out in 132 houses in Poland over a period of one year. The passive method of track detectors with CR-39 foil was applied. Four thermal-precipitation regions in Poland were established and correction factors were calculated for each region, separately for houses with and without basements.

  3. Detecting Hierarchical Structure in Networks

    DEFF Research Database (Denmark)

    Herlau, Tue; Mørup, Morten; Schmidt, Mikkel Nørgaard;

    2012-01-01

    a generative Bayesian model that is able to infer whether hierarchies are present or not from a hypothesis space encompassing all types of hierarchical tree structures. For efficient inference we propose a collapsed Gibbs sampling procedure that jointly infers a partition and its hierarchical structure......Many real-world networks exhibit hierarchical organization. Previous models of hierarchies within relational data has focused on binary trees; however, for many networks it is unknown whether there is hierarchical structure, and if there is, a binary tree might not account well for it. We propose....... On synthetic and real data we demonstrate that our model can detect hierarchical structure leading to better link-prediction than competing models. Our model can be used to detect if a network exhibits hierarchical structure, thereby leading to a better comprehension and statistical account the network....

  4. Development of a low-level radon reference chamber; Entwicklung einer Low-Level-Radon-Referenzkammer

    Energy Technology Data Exchange (ETDEWEB)

    Linzmaier, Diana

    2013-01-04

    The naturally occurring, radioactive noble gas radon-222 exists worldwide in different activity concentrations in the air. During the decay of radon-222, decay products are generated which are electrically charged and attach to aerosols in the air. Together with the aerosols, the radon is inhaled and exhaled by humans. While the radon is nearly completely exhaled, ca. 20 % of the inhaled aerosols remain in the lungs in one breath cycle. Due to ionizing radiation, in a chain of events, lung cancer might occur. Consequently, radon and its decay products are according to the current findings the second leading cause of lung cancer. At the workplace and in the home measurements of radon activity concentration are performed to determine the radiation exposition of humans. All measurement devices for the determination of radon activity concentration are calibrated above 1000 Bq/m{sup 3}, even though the mean value of the present investigation in Germany shows only 50 Bq/m{sup 3}. For the calibration of measurement devices in the range below 1000 Bq/m{sup 3} over a long time period, the generation of a stable reference atmosphere is presented in this work. Due to a long term calibration (t>5 days) of the measurement devices, smaller uncertainties result for the calibration factor. For the calibration procedure, a so-called low-level radon reference chamber was set up and started operation. The generation of a stable reference atmosphere is effected by means of emanation sources which consist of a radium-226 activity standard. On the basis of {gamma}-spectrometry, the effective emanation coefficient ofthe emanation sources is determined. The traceability of the activity concentration in the reference volume is realized via the activity ofthe radium-226, the emanation coefficient and the volume. With the emanation sources produced, stable reference atmospheres within the range of 150 Bq/m{sup 3} to 1900 Bq/m{sup 3} are achieved. For the realization, maintenance and

  5. Context updates are hierarchical

    Directory of Open Access Journals (Sweden)

    Anton Karl Ingason

    2016-10-01

    Full Text Available This squib studies the order in which elements are added to the shared context of interlocutors in a conversation. It focuses on context updates within one hierarchical structure and argues that structurally higher elements are entered into the context before lower elements, even if the structurally higher elements are pronounced after the lower elements. The crucial data are drawn from a comparison of relative clauses in two head-initial languages, English and Icelandic, and two head-final languages, Korean and Japanese. The findings have consequences for any theory of a dynamic semantics.

  6. Indoor radon pollution: Control and mitigation. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    The bibliography contains citations concerning the control and mitigation of radon pollution in homes and commercial buildings. Citations cover radon transport studies in buildings and soils, remedial action proposals on contaminated buildings, soil venting, building ventilation, sealants, filtration systems, water degassing, reduction of radon sources in building materials, and evaluation of existing radon mitigation programs, including their cost effectiveness. Analysis and detection of radon and radon toxicity are covered in separate published bibliographies. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  7. Soil radon monitoring in the Krsko Basin, Slovenia.

    Science.gov (United States)

    Zmazek, B; Zivcić, M; Vaupotic, J; Bidovec, M; Poljak, M; Kobal, I

    2002-04-01

    In order to support the safe operation of the Krsko Nuclear Power Plant (Westinghouse, 676 MWe PWR), the seismotectonic structure of the Krsko basin has been thoroughly investigated. As part of a wider study, a study on radon in soil gas was started in April 1999. Combined barasol detectors buried in six boreholes, two along the Orlica fault and four on either side of it, measure and record radon activity, temperature and pressure every 60 min. The results have been evaluated and the possibility of a correlation with seismic activity is discussed. Correlation between radon concentration and barometric pressure has been observed for all barasols. Preliminary results show that, at one location, the correlation coefficient between radon and barometric pressure changed sign before earthquakes.

  8. Soil radon monitoring in the Krsko Basin, Slovenia

    Energy Technology Data Exchange (ETDEWEB)

    Zmazek, B. E-mail: boris.zmazek@ijs.si; Zivcic, M.; Vaupotic, J.; Bidovec, M.; Poljak, M.; Kobal, I

    2002-04-01

    In order to support the safe operation of the Krsko Nuclear Power Plant (Westinghouse, 676 MW{sub e} PWR), the seismotectonic structure of the Krsko basin has been thoroughly investigated. As part of a wider study, a study on radon in soil gas was started in April 1999. Combined barasol detectors buried in six boreholes, two along the Orlica fault and four on either side of it, measure and record radon activity, temperature and pressure every 60 min. The results have been evaluated and the possibility of a correlation with seismic activity is discussed. Correlation between radon concentration and barometric pressure has been observed for all barasols. Preliminary results show that, at one location, the correlation coefficient between radon and barometric pressure changed sign before earthquakes.

  9. Long term continuous radon monitoring in a seismically active area

    CERN Document Server

    Piersanti, A; Galli, G

    2015-01-01

    We present the results of a long term, continuous radon monitoring experiment started in April 2010 in a seismically active area, affected during the 2010-2013 data acquisition time window by an intense micro seismic activity and by several small seismic events. We employed both correlation and cross-correlation analyses in order to investigate possible relationship existing between the collected radon data, seismic events and meteorological parameters. Our results do not support the feasibility of a robust one-to-one association between the small magnitude earthquakes characterizing the local seismic activity and single radon measurement anomalies, but evidence significant correlation patterns between the spatio-temporal variations of seismic moment release and soil radon emanations, the latter being anyway dominantly modulated by meteorological parameters variations.

  10. Residential Radon Exposure and Risk of Lung Cancer in Missouri

    Science.gov (United States)

    A case-control study of lung cancer and residential radon exposure in which investigators carried out both standard year-long air measurements and CR-39 alpha detector measurements (call surface monitors)

  11. Measurement of indoor radon concentration in kindergartens in Sofia, Bulgaria.

    Science.gov (United States)

    Ivanova, Kremena; Stojanovska, Zdenka; Tsenova, Martina; Badulin, Viktor; Kunovska, Bistra

    2014-11-01

    As a part of the systematic survey of indoor radon in Bulgaria, the indoor radon concentration was measured in 296 kindergarten buildings of Sofia city during 3 months (February to April 2013) using the CR-39 nuclear tract detectors. In 256 buildings at least two frequently occupied rooms (mainly playrooms) were observed. Altogether, 922 measurements were performed. The frequency distribution was well described by the lognormal function. The measured radon concentrations range between 9 and 1415 Bq m(-3) with a geometric mean of 101 Bq m(-3) (2.08) and an arithmetic mean 132 Bq m(-3) with a standard deviation of 118 Bq m(-3). The radon concentrations obtained in this survey were compared with that in Sofia city dwellings obtained from a previous study. A detailed statistical analysis of the building factors was presented.

  12. Anomalous radon emission as precursor of medium to strong earthquakes

    Science.gov (United States)

    Zoran, Maria

    2016-03-01

    Anomalous radon (Rn222) emissions enhanced by forthcoming earthquakes is considered to be a precursory phenomenon related to an increased geotectonic activity in seismic areas. Rock microfracturing in the Earth's crust preceding a seismic rupture may cause local surface deformation fields, rock dislocations, charged particle generation and motion, electrical conductivity changes, radon and other gases emission, fluid diffusion, electrokinetic, piezomagnetic and piezoelectric effects as well as climate fluctuations. Space-time anomalies of radon gas emitted in underground water, soil and near the ground air weeks to days in the epicentral areas can be associated with the strain stress changes that occurred before the occurrence of medium and strong earthquakes. This paper aims to investigate temporal variations of radon concentration levels in air near or in the ground by the use of solid state nuclear track detectors (SSNTD) CR-39 and LR-115 in relation with some important seismic events recorded in Vrancea region, Romania.

  13. Radon Concentration by SSNTD in South-East Sicily Buildings

    Science.gov (United States)

    Immè, G.; Catalano, R.; Gianino, C.; Filincieri, R.; Mangano, G.; Morelli, D.

    Radon levels in buildings vary widely from area to area also depending on local geology. Thus, it is important to assess the radon prone area of a geographic region on the basis of geological data and to search for any possible correlation between the local geology and the indoor radon concentrations. We report about indoor radon measurements in Ragusa, a municipality of the SE Sicily, placed in the Hyblean Plateau (northern region of the African Plate), carried out in collaboration with schools. The survey was performed using Solid State Nuclear Track Detectors (SSNTD), CR-39 type, and a well-established methodology for chemical etching and reading, developed at the Radioactivity Laboratory of the Department of Physics - University of Catania.

  14. Radon measurements by track detectors in Calabrian workplaces

    Energy Technology Data Exchange (ETDEWEB)

    Nastro, V.; Niceforo, G.; Vuono, D.; Luca, P. de; Nastro, A. [Calabria Univ., Dipt. di Pianificazione Territoriale, Arcavacata di Rende, CS (Italy)

    2006-07-01

    Indoor radon studies have been carried out in some workplaces of the South Calabria (Italy) by track detectors CR-39. This study has been undertaken for the purpose of safeguarding the public healthy: since the European population spends, in average, the most greater part of their time in confined environments(residences and offices) the risks of exposure can be elevated. This radon passive measurements are been effectuated according to the recommendations. The exposure time in the workplaces was two different cycle: three months, and six months. The obtained results indicate a radon concentration not only in an average of low level but also in the range of action level (>500 Bq/m{sup 3}). In this last case will be necessary to reduce the radon pollution by adequate land operation works, and a continuous monitoring is also necessary.

  15. Radon levels in the volcanic region of La Garrotxa, Spain

    Energy Technology Data Exchange (ETDEWEB)

    Baixeras, C. [Grup de Fisica de les Radiacions. Edifici Cc, Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain)]. E-mail: carmen.baixeras@uab.es; Bach, J. [Unitat de Geodinamica Externa. Departament de Geologia. Edifici Cs, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Amgarou, K. [Grup de Fisica de les Radiacions. Edifici Cc, Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Moreno, V. [Grup de Fisica de les Radiacions. Edifici Cc, Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Font, Ll. [Grup de Fisica de les Radiacions. Edifici Cc, Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain)

    2005-11-15

    A preliminary survey in the city of Olot, the main town of the volcanic region of La Garrotxa, showed that dwellings built on volcanic formations present higher indoor radon levels than dwellings on non-volcanic materials. The soil of the area is not especially rich in radium. However, some of the volcanic materials present very high permeability and therefore radon entering the houses might have travelled over long distances. In this paper we present indoor radon values measured in a larger survey carried out during April-July 2004. The influence of the volcanic materials found in the preliminary survey has been confirmed. The results obtained suggest the possibility that radon comes from the degassification of mantle through active faults. The values obtained in working places do not constitute a relevant radiological risk for workers.

  16. Residential radon and lung cancer incidence in a Danish cohort

    DEFF Research Database (Denmark)

    Bräuner, Elvira Vaclavik; Andersen, Claus Erik; Sørensen, Mette

    2012-01-01

    non-smokers. We found no evidence of effect modification.We find a positive association between radon and lung cancer risk consistent with previous studies but the role of chance cannot be excluded as these associations were not statistically significant. Our results provide valuable information......High-level occupational radon exposure is an established risk factor for lung cancer. We assessed the long-term association between residential radon and lung cancer risk using a prospective Danish cohort using 57,053 persons recruited during 1993–1997. We followed each cohort member for cancer...... occurrence until 27 June 2006, identifying 589 lung cancer cases. We traced residential addresses from 1 January 1971 until 27 June 2006 and calculated radon at each of these addresses using information from central databases regarding geology and house construction. Cox proportional hazards models were used...

  17. Radon 10 x 10 project: Implantation of geographic information systems in studies of radon in homes and geology catalans; Proyecto radon 10x10: aplicacion de los sistemas de informacion geografica en estudios de radon y geologia en viviendas catalanas

    Energy Technology Data Exchange (ETDEWEB)

    Amado Sanjuan, J. L.; Bach Plaza, J.; Baixeras divar, C.; Font Guiteras, L. L.; Moreno Balta, V.

    2013-07-01

    This methodology provides a useful tool to establish relationships between different data in order to identify areas in which to assess the radiological risk that represents radon in the Catalan population and gagging. (Author)

  18. Mapping radon-prone areas - a geophysical approach

    Energy Technology Data Exchange (ETDEWEB)

    Shirav, M. [Geological Survey of Israel, Jerusalem (Israel); Vulkan, U. [Soreq Nuclear Research Center, Yavne (Israel)

    1997-06-01

    Radon-prone areas in Israel were mapped on the basis of direct measurements of radon ({sup 222}Rn) in the soil/rock gas of all exposed geological units, supported by the accumulated knowledge of local stratigraphy and sub-surface geology. Measurements were carried out by a modified alpha-track detection system, resulting in high radon levels mainly in rocks of the Senonian-Paleocene-aged Mount Scopus Group, comprised of chert-bearing marly chalks, rich in phosphorite which acts as the major uranium source. Issues of source depth, seasonal variations and comparison with indoor radon levels are addressed as well. This approach could be applied to other similar terrains, especially the Mediterranean Phosphate Belt. (orig.)

  19. Radon programme in the Netherlands: risk assessment and risk management

    Energy Technology Data Exchange (ETDEWEB)

    Jung, D.W.G. [Ministry of Housing, Physical Planning and Environment, The Hague (Netherlands). Directorate for Chemicals, External Safety and Radiation Protection

    1994-12-31

    The Dutch policy on the control of the risk of radon is predominantly based on the results of the Radon Research Programme. Important topics of the Radon Research Programme are described. Furthermore, the Dutch policy on indoor radiation is reviewed in view of the national environmental policy and radiation risk management. The policy on the control of radon in domestic and other buildings is related to other policies, both national and international, e.g. economic, environmental and housing policy. A short review of these relations in the Netherlands is given. In brief a description will be given of the attention paid by the government to the communication strategies used in order to enforce, for instance, remedial actions and the implementation of risk reduction technology. (author).

  20. Radon emanation from phosphogypsum and related mineral samples in Cyprus

    Energy Technology Data Exchange (ETDEWEB)

    Lysandrou, M. [Geological Survey Department, Ministry of Agriculture, Natural Resources and Environment (Cyprus); Department of Chemistry, University of Cyprus, P.O. Box 20537, Cy-1678 Lefkosia (Cyprus); Charalambides, A. [Geological Survey Department, Ministry of Agriculture, Natural Resources and Environment (Cyprus); Pashalidis, I. [Department of Chemistry, University of Cyprus, P.O. Box 20537, Cy-1678 Lefkosia (Cyprus)], E-mail: pspasch@ucy.ac.cy

    2007-10-15

    Radon emanation rates from phosphogypsum samples have been determined to assess the radiological impact of radon emanated from a phosphogypsum disposal site. For comparison corresponding measurements were conducted with samples of phosphate rock, fertilizer, natural gypsum, and calcite. The experimental data show that phosphate rock and phosphogypsum samples emanate radon in significantly higher rates (up to almost two orders of magnitude). The exhalation rates determined for samples obtained from a phosphogypsum stack in Cyprus range from 0.35 to 1.1Bqh{sup -1}. This, consequently, may result in increased radon levels in dwellings build and excessive radiation exposure to workers residing on the stack, which could reach in extreme cases values up to 17mSvy{sup -1}.

  1. A study of diurnal variation of indoor radon concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Ramola, R.C.; Kandari, M.S.; Negi, M.S. [H.N.B. Garhwal Univ. (India); Choubey, V.M.

    2000-06-01

    Since there are scarce data of diurnal variation of indoor radon levels in houses, authors measured it in different types of houses in Budhakedar (B, mud houses) and Tehri (T, ordinary concrete ones) of Garhwal Himalaya in comparison with environmental parameters. The portable AlphaGUARD (M/S Genitron Instr.) which having an ionization chamber detector, used for measurement was kept inside the houses for about 24 hr to record the levels of radon and environmental variables like air temperature. The indoor radon concentration for a well-ventilated house was found to vary largely within 24 hr. The concentrations in February 1998 were 40-784 Bq/m{sup 3} in B and 12-338 Bq/m{sup 3} in T inside the houses, the latter of which was found affected by the environmental parameters. Radon concentrations in mud houses were higher than those in T. (K.H.)

  2. Residential Radon and Brain Tumour Incidence in a Danish Cohort

    DEFF Research Database (Denmark)

    Bräuner, Elvira V.; Andersen, Zorana J.; Andersen, Claus Erik;

    2013-01-01

    (CI) for the risk of primary brain tumours associated with residential radon exposure with adjustment for age, sex, occupation, fruit and vegetable consumption and traffic-related air pollution. Effect modification by air pollution was assessed. Results: Median estimated radon was 40.5 Bq/m3......Background: Increased brain tumour incidence over recent decades may reflect improved diagnostic methods and clinical practice, but remain unexplained. Although estimated doses are low a relationship between radon and brain tumours may exist. Objective: To investigate the long-term effect...... of exposure to residential radon on the risk of primary brain tumour in a prospective Danish cohort. Methods: During 1993–1997 we recruited 57,053 persons. We followed each cohort member for cancer occurrence from enrolment until 31 December 2009, identifying 121 primary brain tumour cases. We traced...

  3. A map of radon flux at the Australian land surface

    Directory of Open Access Journals (Sweden)

    A. D. Griffiths

    2010-06-01

    Full Text Available A time-dependent map of radon-222 flux density at the Australian land surface has been constructed with a spatial resolution of 0.05° and temporal resolution of one month. Radon flux density was calculated from a simple model utilising data from national gamma-ray aerial surveys, modelled soil moisture, and maps of soil properties. The model was calibrated against a large data set of accumulation-chamber measurements, thereby constraining it with experimental data. A notable application of the map is in atmospheric mixing and transport studies which use radon as a tracer, where it is a clear improvement on the common assumption of uniform radon flux density.

  4. A map of radon flux at the Australian land surface

    Directory of Open Access Journals (Sweden)

    A. D. Griffiths

    2010-09-01

    Full Text Available A time-dependent map of radon-222 flux density at the Australian land surface has been constructed with a spatial resolution of 0.05° and temporal resolution of one month. Radon flux density was calculated from a simple model utilising data from national gamma-ray aerial surveys; modelled soil moisture, available from 1900 in near real-time; and maps of soil properties. The model was calibrated against a data set of accumulation chamber measurements, thereby constraining it with experimental data. A notable application of the map is in atmospheric mixing and transport studies which use radon as a tracer, where it is a clear improvement on the common assumption of uniform radon flux density.

  5. Residential Radon Exposure and Risk of Lung Cancer in Missouri

    Science.gov (United States)

    A case-control study of lung cancer and residential radon exposure in which investigators carried out both standard year-long air measurements and CR-39 alpha detector measurements (call surface monitors)

  6. Preparation of higher fluorides and oxides of radon

    Energy Technology Data Exchange (ETDEWEB)

    Avrorin, V.V.; Krasikov, R.N.; Nefedov, V.D.; Toropova, M.A.

    1981-01-01

    It has been established that interaction of radon and fluorine results in the formation of only lower radon fluoride. However if the catalyst (NiF/sub 2/) or donor of fluorine-ions (NaF) are introduced into reaction mixture and the reaction is conducted in the presence of boron pentafluoride as a solvent, one of the higher radon fluorides is formed (RnF/sub 4/ or RnF/sub 6/). During the hydrolysis of the higher fluoride a radon compound, stable in aqueous solutions, is formed, its probable composition being described as RnO/sub 3/. This composition of the oxide is confirmed by its ability to coprecipitate with barium xenate.

  7. A reconnaissance study of radon concentration in Hamadan city, Iran.

    Science.gov (United States)

    Gillmore, G. K.; Jabari Vasal, Naghi

    2009-04-01

    This paper presents results of a reconnaissance study that used CR-39 alpha track-etch detectors to measure radon concentrations in dwellings in Hamadan, western Iran, significantly, built on permeable alluvial fan deposits. The indoor radon levels recorded varied from 4 to 364 Bq/m3 with a mean value of 107.87 Bq/m3 which is 2.5 times the average global population-weighted indoor radon concentration - these data augment the very few published studies on indoor radon levels in Iran. The maximum radon concentration in Hamadan occurs during the winter period (January to March) with lower concentrations during the autumn. The effective dose equivalent to the population in Hamadan is estimated from this reconnaissance study to be in the region of 2.7 mSv/y, which is above the guidelines for dose to a member of the public of 1 mSv/y suggested by the International Commission on Radiological Protection (ICRP) in 1993, although further work is required to confirm these results. This study supports other work in a number of countries that indicates such permeable 'surficial' deposits as being of intermediate to high radon potential. In western Iran, the presence of hammered clay floors, the widespread presence of excavated qanats to distribute water underground, the textural properties of surficial deposits and human behaviour intended to cope with winds are likely to be important factors influencing radon concentrations in older buildings. Keywords: Radon; health; dwellings; clay floors; alluvial fan; surficial geology; Hamadan; Iran

  8. Residential radon and lung cancer incidence in a Danish cohort

    Energy Technology Data Exchange (ETDEWEB)

    Braeuner, Elvira V., E-mail: ole@cancer.dk [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark); Danish Building Research Institute, Aalborg University (Denmark); Andersen, Claus E. [Center for Nuclear Technologies, Radiation Research Division, Riso National Laboratory for Sustainable Energy, Technical University of Denmark, Roskilde (Denmark); Sorensen, Mette [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark); Jovanovic Andersen, Zorana [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark); Center for Epidemiology Screening, Department of Public Health, University of Copenhagen (Denmark); Gravesen, Peter [Geological Survey of Denmark and Greenland, Copenhagen (Denmark); Ulbak, Kaare [National Institute of Radiation Protection, Herlev (Denmark); Hertel, Ole [Department of Environmental Science, Aarhus University, Aarhus (Denmark); Pedersen, Camilla [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark); Overvad, Kim [Department of Epidemiology, School of Public Health, Aarhus University, Aarhus (Denmark); Tjonneland, Anne; Raaschou-Nielsen, Ole [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark)

    2012-10-15

    High-level occupational radon exposure is an established risk factor for lung cancer. We assessed the long-term association between residential radon and lung cancer risk using a prospective Danish cohort using 57,053 persons recruited during 1993-1997. We followed each cohort member for cancer occurrence until 27 June 2006, identifying 589 lung cancer cases. We traced residential addresses from 1 January 1971 until 27 June 2006 and calculated radon at each of these addresses using information from central databases regarding geology and house construction. Cox proportional hazards models were used to estimate incidence rate ratios (IRR) and 95% confidence intervals (CI) for lung cancer risk associated with residential radon exposure with and without adjustment for sex, smoking variables, education, socio-economic status, occupation, body mass index, air pollution and consumption of fruit and alcohol. Potential effect modification by sex, traffic-related air pollution and environmental tobacco smoke was assessed. Median estimated radon was 35.8 Bq/m{sup 3}. The adjusted IRR for lung cancer was 1.04 (95% CI: 0.69-1.56) in association with a 100 Bq/m{sup 3} higher radon concentration and 1.67 (95% CI: 0.69-4.04) among non-smokers. We found no evidence of effect modification. We find a positive association between radon and lung cancer risk consistent with previous studies but the role of chance cannot be excluded as these associations were not statistically significant. Our results provide valuable information at the low-level radon dose range.

  9. Residential radon and lung cancer incidence in a Danish cohort.

    Science.gov (United States)

    Bräuner, Elvira V; Andersen, Claus E; Sørensen, Mette; Andersen, Zorana Jovanovic; Gravesen, Peter; Ulbak, Kaare; Hertel, Ole; Pedersen, Camilla; Overvad, Kim; Tjønneland, Anne; Raaschou-Nielsen, Ole

    2012-10-01

    High-level occupational radon exposure is an established risk factor for lung cancer. We assessed the long-term association between residential radon and lung cancer risk using a prospective Danish cohort using 57,053 persons recruited during 1993-1997. We followed each cohort member for cancer occurrence until 27 June 2006, identifying 589 lung cancer cases. We traced residential addresses from 1 January 1971 until 27 June 2006 and calculated radon at each of these addresses using information from central databases regarding geology and house construction. Cox proportional hazards models were used to estimate incidence rate ratios (IRR) and 95% confidence intervals (CI) for lung cancer risk associated with residential radon exposure with and without adjustment for sex, smoking variables, education, socio-economic status, occupation, body mass index, air pollution and consumption of fruit and alcohol. Potential effect modification by sex, traffic-related air pollution and environmental tobacco smoke was assessed. Median estimated radon was 35.8 Bq/m(3). The adjusted IRR for lung cancer was 1.04 (95% CI: 0.69-1.56) in association with a 100 Bq/m(3) higher radon concentration and 1.67 (95% CI: 0.69-4.04) among non-smokers. We found no evidence of effect modification. We find a positive association between radon and lung cancer risk consistent with previous studies but the role of chance cannot be excluded as these associations were not statistically significant. Our results provide valuable information at the low-level radon dose range.

  10. The influence of thoron on instruments measuring radon activity concentration.

    Science.gov (United States)

    Michielsen, N; Bondiguel, S

    2015-11-01

    Thoron, the isotope 220 of radon, is a radionuclide whose concentration may influence the measurement of the activity concentration of (222)Rn in the air. If in the case of continuous and active sampling measuring instruments, using a pump for example, the influence of thoron on radon measurement is obvious and is taken into account in the apparatus, it is often assumed that in the case of a passive sampling, by diffusion through a filter for example, this thoron influence is negligible. This is due to the very short radioactive half-life of thoron, 55.6 s (3.82 d for (222)Rn), and the assumption that the diffusion time of thoron in the detection chamber is long enough beside that of the thoron half-life. The objective of this study is to check whether this assumption is true or not for different kinds of commercial electronic apparatus used to measure radon activity concentration from soil to dwellings. First of all, the devices were calibrated in activity concentration of radon, and then they were exposed to a controlled thoron atmosphere. The experiments concerning the thoron aimed to investigate the sensitivity to thoron in the radon measuring mode of the apparatus. Results of these experiments show that all devices have a very quick answer to thoron atmosphere, even though the sensitivities vary from one instrument to another. Results clearly show that this influence on radon measurement due to the thoron is observed also after the exposition because of the decay of (212)Pb and its progenies. In conclusion, the sensitivity to thoron in the radon measuring mode depends strongly on the type of instruments. The results of the present investigation show that for some apparatus, the influence of thoron cannot be disregarded especially when measuring radon in soil.

  11. Discrete-Event Simulation

    Directory of Open Access Journals (Sweden)

    Prateek Sharma

    2015-04-01

    Full Text Available Abstract Simulation can be regarded as the emulation of the behavior of a real-world system over an interval of time. The process of simulation relies upon the generation of the history of a system and then analyzing that history to predict the outcome and improve the working of real systems. Simulations can be of various kinds but the topic of interest here is one of the most important kind of simulation which is Discrete-Event Simulation which models the system as a discrete sequence of events in time. So this paper aims at introducing about Discrete-Event Simulation and analyzing how it is beneficial to the real world systems.

  12. Discrete Anderson Speckle

    CERN Document Server

    Kondakci, H Esat; Saleh, Bahaa E A

    2016-01-01

    When a disordered array of coupled waveguides is illuminated with an extended coherent optical field, discrete speckle develops: partially coherent light with a granular intensity distribution on the lattice sites. The same paradigm applies to a variety of other settings in photonics, such as imperfectly coupled resonators or fibers with randomly coupled cores. Through numerical simulations and analytical modeling, we uncover a set of surprising features that characterize discrete speckle in one- and two-dimensional lattices known to exhibit transverse Anderson localization. Firstly, the fingerprint of localization is embedded in the fluctuations of the discrete speckle and is revealed in the narrowing of the spatial coherence function. Secondly, the transverse coherence length (or speckle grain size) is frozen during propagation. Thirdly, the axial coherence depth is independent of the axial position, thereby resulting in a coherence voxel of fixed volume independently of position. We take these unique featu...

  13. Discrete systems and integrability

    CERN Document Server

    Hietarinta, J; Nijhoff, F W

    2016-01-01

    This first introductory text to discrete integrable systems introduces key notions of integrability from the vantage point of discrete systems, also making connections with the continuous theory where relevant. While treating the material at an elementary level, the book also highlights many recent developments. Topics include: Darboux and Bäcklund transformations; difference equations and special functions; multidimensional consistency of integrable lattice equations; associated linear problems (Lax pairs); connections with Padé approximants and convergence algorithms; singularities and geometry; Hirota's bilinear formalism for lattices; intriguing properties of discrete Painlevé equations; and the novel theory of Lagrangian multiforms. The book builds the material in an organic way, emphasizing interconnections between the various approaches, while the exposition is mostly done through explicit computations on key examples. Written by respected experts in the field, the numerous exercises and the thoroug...

  14. Discrete Classical Electromagnetic Fields

    CERN Document Server

    De Souza, M M

    1997-01-01

    The classical electromagnetic field of a spinless point electron is described in a formalism with extended causality by discrete finite transverse point-vector fields with discrete and localized point interactions. These fields are taken as a classical representation of photons, ``classical photons". They are all transversal photons; there are no scalar nor longitudinal photons as these are definitely eliminated by the gauge condition. The angular distribution of emitted photons coincides with the directions of maximum emission in the standard formalism. The Maxwell formalism and its standard field are retrieved by the replacement of these discrete fields by their space-time averages, and in this process scalar and longitudinal photons are necessarily created and added. Divergences and singularities are by-products of this averaging process. This formalism enlighten the meaning and the origin of the non-physical photons, the ones that violate the Lorentz condition in manifestly covariant quantization methods.

  15. Measurements of thoron and radon progeny concentrations in Beijing, China

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lei; Liu Cuihong; Guo Qiuju [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China)], E-mail: qjguo@pku.edu.cn

    2008-12-15

    It has been reported that thoron levels in China are above the world average and may therefore make a significant contribution to the natural background radiation dose. We therefore conducted a pilot study of concentrations of both thoron and radon progeny during the spring of 2006 in the Beijing area, China. A new type of portable 24 h integrating monitor with a CR-39 detector was used during the survey. Seventy dwellings and eight outdoor sites were measured during the survey. For country houses built of red bricks and slurry, the average equilibrium equivalent concentrations (EEC) of thoron and radon were 1.02 {+-} 0.48 and 16.41 {+-} 9.02 Bq m{sup -3}, respectively, whereas for city dwellings built of cement blocks and floor slabs, the results were 0.48 {+-} 0.47 and 11.50 {+-} 6.99 Bq m{sup -3} for thoron and radon, respectively. For outdoor air, concentrations of thoron and radon progeny were 0.29 {+-} 0.28 and 7.05 {+-} 2.68 Bq m{sup -3}, respectively. Radiation exposures from thoron and radon progeny were also evaluated; the ratio of dose contribution from thoron progeny to that of radon progeny was evaluated to be 28% and 17% in country houses and city dwellings, respectively. (note)

  16. Radon problem in an underground low-level laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Udovicic, V., E-mail: udovicic@phy.bg.ac.y [Institute of Physics, PO Box 57, 11001 Belgrade (Serbia); Grabez, B.; Dragic, A.; Banjanac, R.; Jokovic, D.; Panic, B.; Joksimovic, D. [Institute of Physics, PO Box 57, 11001 Belgrade (Serbia); Puzovic, J. [Faculty of Physics, PO Box 368, 11000 Belgrade (Serbia); Anicin, I. [Institute of Physics, PO Box 57, 11001 Belgrade (Serbia)

    2009-10-15

    The low-level gamma-ray spectroscopy as well as the investigation of rare nuclear processes require not only low, but also constant levels of relevant background radiations. In underground laboratories dedicated to this type of measurements, one of the main and hard to control sources of unwanted radiation is the radioactive gas radon. It is well-known that radon concentration varies daily and seasonally, primarily due to the variation of atmospheric parameters. This introduces unwanted and hard to evaluate systematic uncertainties in long-term low-level measurements. In this paper, the system for radon reduction in the underground Low-Background Laboratory for Nuclear Physics at the Institute of Physics in Belgrade is presented in some detail. The laboratory exists for ten years and different measurements of radon concentration were carried out during this period. The indoor radon measurements are performed using nuclear track detectors (type CR-39 and LR-115) for long-term measurements and the commercially available radon monitor for short-term measurements. In this work we present the results of these measurements for the period 2003-2008.

  17. Radon concentrations in three underground lignite mines in Turkey.

    Science.gov (United States)

    Cile, S; Altinsoy, N; Celebi, N

    2010-01-01

    Monitoring of radon in underground mines is important in order to assess the radiological hazards to occupational workers. Radon concentration levels in three underground lignite mines (Tunçbilek, Omerler and Eynez) of Turkey were obtained in this study. For this reason, atmospheric radon level measurements were carried out in mines using CR-39 track detectors. Chemical etching of the detector tracks and subsequent counting were performed at Cekmece Nuclear Research and Training Center. The obtained results were evaluated according to the International Commission of Radiation Protection and the Turkish Atomic Energy Authority whose radon action levels for workplaces are 500-1500 and 1000 Bq(-3), respectively. The radon gas concentrations in the lignite mines were determined to be between 50 +/- 7 and 587 +/- 16 Bq m(-3). The results obtained in these experiments are far under the action levels. The computed radon doses for the mine workers of Tunçbilek, Omerler and Eynez lignite mines are 1.23, 2.44 and 1.47 mSv y(-1), respectively.

  18. Indoor Radon Concentration Levels in Najran Region, Saudi Arabia

    Science.gov (United States)

    Alyami, S. H.; Al-Ghamdi, S. S.; Baig, M. R.; Al-Garawi, M. S.

    2010-07-01

    Measurement of indoor radon concentration was performed in Najran region in the south west of Saudi Arabia, using CR-39 dosimeter. Despite many previous studies on indoor radon concentrations in Saudi Arabia, the data available are still limited. The objective of this study, which is the first of its kind in the region, is to have preliminary data of radon in this region. Such measurement will contribute towards further studies in this region of Saudi Arabia. The indoor radon concentration was measured in the villages of Fara Al-Jabal and Badr Al-Janoob (about 2000 m above sea level), Hadadah and Al-Khanig (about 1700 m above sea level). It was found that radon distribution in these villages is normal skewed to the right, with a range of 9±5 to 163±32 Bqm-3 and an average of 49±2 Bqm-3. It was also found that the average radon concentration is independent of altitude. Our findings show that the values are below the safe limit of 150 Bqm-3 set by the Environmental Protection Agency (EPA) of the USA

  19. Preliminary integrated indoor radon measurements in Transylvania (Romania).

    Science.gov (United States)

    Cosma, Constantin; Szacsvai, Kinga; Dinu, Alexandra; Ciorba, Daniela; Dicu, Tiberius; Suciu, Liviu

    2009-09-01

    Measurements of indoor radon concentrations were performed in 406 residential houses in five counties (Cluj, Bihor, Alba, Bistrita, and Sibiu) using Makrofol and CR-39 alpha-track detectors. From our measurements, an average indoor radon concentration of 82.5 Bq m(-3) for the Transylvanian population was calculated, i.e. an annual effective dose of 2.4 mSv for the whole body. The calculated dose is 62% higher than that previously reported but yet below the recommended action level of ICRP (International Commission on Radiological Protection). A log-normal distribution of the radon concentration was obtained for the studied counties, excluding some higher values from the Stei region--a radon-prone area in Transylvania. For the Stei region, the data show a dual log-normal distribution of the radon concentration with the second maximum being related to the houses built using uranium waste as a construction material. Assuming a cancer risk coefficient of 10(-4)/100 Bq m(-3) year(-1), one can estimate that about 600 lung cancer per year, for about 7,000,000 inhabitants of the Transylvania region, are due to radon inhalation.

  20. Radon concentrations in three underground lignite mines in Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Cile, S.; Altinsoy, N.; Celebi, N. [Istanbul Technical University, Istanbul (Turkey). Inst. of Energy

    2010-01-15

    Monitoring of radon in underground mines is important in order to assess the radiological hazards to occupational workers. Radon concentration levels in three underground lignite mines (Tuncbilek, Omerler and Eynez) of Turkey were obtained in this study. For this reason, atmospheric radon level measurements were carried out in mines using CR-39 track detectors. Chemical etching of the detector tracks and subsequent counting were performed at Cekmece Nuclear Research and Training Center. The obtained results were evaluated according to the International Commission of Radiation Protection and the Turkish Atomic Energy Authority whose radon action levels for workplaces are 500-1500 and 1000 Bq{sup -3}, respectively. The radon gas concentrations in the lignite mines were determined to be between 50 {+-} 7 and 587 {+-} 16 Bq m{sup -3}. The results obtained in these experiments are far under the action levels. The computed radon doses for the mine workers of Tuncbilek, Omerler and Eynez lignite mines are 1.23, 2.44 and 1.47 mSv y{sup -1}, respectively.