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Sample records for rn exposure chamber

  1. Development of an aerosol chamber for calibration of 220Rn progeny detectors

    Science.gov (United States)

    Sorimachi, Atsuyuki; Ishikawa, Tetsuo; Tokonami, Shinji

    2014-09-01

    This paper describes an aerosol chamber system that can be used for calibrations and performance experiments of passive 220Rn progeny detectors. For the purpose of this study, an aerosol generation system using carnauba wax as the aerosol material was mounted into the 220Rn chamber. We used the chamber to measure characteristics of the equilibrium factor (F) of 220Rn and unattached fraction (fp) of 220Rn progeny, which are important parameters for dose estimation. The first experiment showed that continuous and stable generation of the unattached and aerosol-attached 220Rn progeny concentrations was obtained. We observed that the spatial distributions in the chamber of the vertical profiles of the unattached and aerosol-attached 220Rn progeny concentrations were homogeneous, as were the particle number concentration and count median diameter. The values of F and fp and their characteristics observed in this study were in the same range as the values reported from indoor measurements. We found that the characteristics of F and fp were dependent on the aerosol conditions (particle diameter and particle number concentration).

  2. Exposure of burrowing mammals to {sup 222}Rn

    Energy Technology Data Exchange (ETDEWEB)

    Beresford, N.A., E-mail: nab@ceh.ac.uk [NERC Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Av. Bailrigg, Lancaster LA1 4AP (United Kingdom); Barnett, C.L. [NERC Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Av. Bailrigg, Lancaster LA1 4AP (United Kingdom); Vives i Batlle, J. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, 2400 Mol (Belgium); Potter, E.D. [NERC Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Av. Bailrigg, Lancaster LA1 4AP (United Kingdom); Ibrahimi, Z.-F. [Health Protection Agency, Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot OX11 0RQ (United Kingdom); Barlow, T.S.; Schieb, C.; Jones, D.G. [British Geological Survey, Environmental Science Centre, Keyworth, Nottingham NG12 5GG (United Kingdom); Copplestone, D. [School of Natural Sciences, University of Stirling, Stirling FK9 4LA (United Kingdom)

    2012-08-01

    Estimates of absorbed dose rates to wildlife from exposure to natural background radionuclides are required to put estimates of dose rates arising from regulated releases of radioactivity and proposed benchmarks into context. Recent review papers have estimated dose rates to wildlife from {sup 40}K, and {sup 238}U and {sup 232}Th series radionuclides. However, only one study previous has considered the potential dose rates to burrowing animals from inhaled {sup 222}Rn and its daughter products. In this paper we describe a study conducted at seven sites in northwest England. Passive track etch detectors were used to measure the {sup 222}Rn concentrations in artificial burrows over a period of approximately one year. Results suggest that absorbed dose rates to burrowing mammals as a consequence of exposure to {sup 222}Rn are likely to be at least an order of magnitude higher than those suggested in previous evaluations of natural background exposure rates which had omitted this radionuclide and exposure pathway. Dose rates in some areas of Great Britain will be considerably in excess of incremental no-effects benchmark dose rates suggested for use as screening levels. Such advised benchmark dose rates need to be better put into context with background dose rates, including exposure to {sup 222}Rn, to ensure credibility; although the context will be determined by the purpose of the benchmark and the assessment level. - Highlights: Black-Right-Pointing-Pointer Determined {sup 222}Rn concentrations in artificial burrows. Black-Right-Pointing-Pointer Estimated dose rates to burrowing mammals from inhaled {sup 222}Rn and daughter products. Black-Right-Pointing-Pointer {sup 222}Rn likely to dominate exposure of burrowing mammals due to natural radionuclides.

  3. Rn daughter exposure to U miners

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, B L

    1982-04-01

    Radon exposures to U.S. uranium miners under present conditions average about 1.3 WLM per year approximately or equal to 60 WLM per full working lifetime. This is intermediate between the lowest exposures for which there have been excess lung cancers reported among U.S. miners (120-240 WLM) and average environmental radon exposures (16 WLM), so models based on these two situations are used to estimate expected effects on present uranium miners. In Model A, the loss of life expectancy is 45 days, the SMR (standardized mortality ratio) for lung cancer is 1.10, and the SMR for all causes between ages 18 and 65 is 1.013. In Model B these are 10 days, 1.03 and 1.002 respectively. It is shown that the radon exposures to miners are similar to those to millions of Americans from environmental exposure, and that miner health risks are comparable to those of other radiation workers. Their lung cancer risk from radon is 7-50 times less than their job-related accident mortality risk, and represents 0.7-4% of their total risk in mining. Miners suffer from many diseases with SMR very much larger than that for radon-induced lung cancer, and there are many other occupations and industries with far higher SMR for lung cancer than that from radon exposure to miners.

  4. Design issues in epidemiologic studies of indoor exposure to Rn and risk of lung cancer

    International Nuclear Information System (INIS)

    Lubin, J.H.; Samet, J.M.; Weinberg, C.

    1990-01-01

    Recent data on indoor air quality have indicated that Rn (222Rn) and its decay products are frequently present in domestic environments. Their presence in indoor air raises concerns about an increase in lung cancer risk for the general population. To directly evaluate lung cancer risk from domestic exposure to Rn and its decay products, as well as to evaluate risk assessments derived from studies of Rn-exposed underground miners, several epidemiologic studies of indoor Rn exposure have been initiated or are planned. This paper calculates sample sizes required for a hypothetical case-control study to address several important hypotheses and shows the impact of difficult problems associated with estimating a subject's Rn exposure. We consider the effects of subject mobility, choice of the exposure response trend which is used to characterize an alternative hypothesis, and errors in the estimation of exposure. Imprecise estimation of Rn exposure arises from errors in the measurement device, exposure to Rn decay products from sources outside the home, inability to measure exposures over time in current as well as previous residences, and the unknown relationship between measured concentration and lung dose of alpha energy from the decay of Rn and its progeny. These methodological problems can result in large discrepancies between computed and actual study power. Failure to anticipate these problems in the design of a study can result in inaccurate estimates of power. We conclude that case-control studies of indoor Rn and lung cancer may require substantial numbers of subjects in order to address the many questions of importance that burden current risk assessments with uncertainty. We suggest pooling data from studies with the largest numbers of cases and with the most precise estimates of Rn exposure as the best approach for meeting present research needs

  5. Assessment of 222Rn occupational exposure at IPEN nuclear materials storage site, SP, Brazil

    International Nuclear Information System (INIS)

    Caccuri, Lilian Saueia

    2007-01-01

    In this study it was assessed the occupational exposure to 222 Rn at IPEN, SP, Brazil, nuclear materials storage site through the committed effective dose received by workers exposed to this radionuclide. The radiation dose was calculated through the radon concentrations at nuclear materials storage site. Radon concentrations were determined by passive detection method with solid state nuclear detectors (SSNTD). The SSNTD used in this study was the polycarbonate Makrofol E; each detector is a small square plastic of 1 cm 2 , placed into a diffusion chamber type KFK. It was monitored 14 points at nuclear materials storage site and one external point, over a period of 21 months, changing the detectors every three months, from December 2004 to September 2006. The 222 Rn concentrations varied from 196 ± 9 and 2048 ± 81 Bq·m -3 . The committed effective dose due to radon inhalation at IPEN nuclear materials storage site was obtained from radon activity incorporated and dose conversion factor, according to International Commission on Radiological Protection procedures. The effective committed dose received by workers is below 20 mSv·y -1 . This value is suggested as an annual effective dose limit for occupational exposure by ICRP 60. (author)

  6. Design of real-time monitoring and control system of 222Rn/220Rn sampling for radon chamber

    International Nuclear Information System (INIS)

    Wu Rongyan; Zhao Xiuliang; Zhang Meiqin; Yu Hong

    2008-01-01

    This paper describes the design of 222 Rn/ 220 Rn sampling monitoring and control system based on single-chip microcomputer of series Intel51. The hardware design involves the choosing and usage of sensors-chips, A/D conversion-chip, USB interface-chip, keyboard-chip, digital display-chip, photoelectric coupling isolation-chips and drive circuit-chips of the direct current pump. Software design is composed by software of Personal Computer (PC) and software of Single Chip Microcomputer (SCM). The data acquisition and conversion and the flux control of direct current pump are realized by using soft of Visual Basic and assemble language. The program flow charts are given. Furthermore, we improved the stability of the direct current pump by means of PID Control Algorithms. (authors)

  7. Characterization of the personal dosimeter Rn-disk for monitoring radon exposure

    International Nuclear Information System (INIS)

    Orlando, P.; Arcovito, G.; Amici, M.; Orlando, C.; Cardellini, F.; Fiorentino, A.; Trevisi, R.

    2009-01-01

    Rn-disk is a new passive device for measuring occupational exposure to radon 222, are presented the results of tests for the characterization of the dosimeter as a tool for estimating the individual dose for workers. [it

  8. High-resolution ion pulse ionization chamber with air filling for the {sup 222}Rn decays detection

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilyuk, Yu.M.; Gangapshev, A.M.; Gezhaev, A.M.; Etezov, R.A.; Kazalov, V.V.; Kuzminov, V.V. [Baksan Neutrino Observatory,Institute for Nuclear Research RAS, 361609 Neutrino (Russian Federation); Panasenko, S.I. [V.N.Karazin Kharkiv National University, 61022 Kharkiv (Ukraine); Ratkevich, S.S., E-mail: ssratk@gmail.com [V.N.Karazin Kharkiv National University, 61022 Kharkiv (Ukraine); Tekueva, D.A.; Yakimenko, S.P. [Baksan Neutrino Observatory,Institute for Nuclear Research RAS, 361609 Neutrino (Russian Federation)

    2015-11-21

    The construction and characteristics of the cylindrical ion pulse ionization chamber (CIPIC) with a working volume of 3.2 L are described. The chamber is intended to register α-particles from the {sup 222}Rn and its daughter's decays in the filled air sample. The detector is less sensitive to electromagnetic pick-ups and mechanical noises. The digital pulse processing method is proposed to improve the energy resolution of the ion pulse ionization chamber. An energy resolution of 1.6% has been achieved for the 5.49 MeV α-line. The dependence of the energy resolution on high voltage and working media pressure has been investigated and the results are presented. - Highlights: • The construction and characteristics of the cylindrical ion pulse ionization chamber (CIPIC) with a working volume of 3.2 L are described. • The chamber is intended to register alpha-particles from {sup 222}Rn and its daughter's decays in the filled air sample. • The detector is less sensitive to electromagnetic pick-ups and mechanical noises. • An energy resolution of 1.6% has been achieved for the 5.49 MeV alpha-line. The dependence of the energy resolution on high voltage and working media pressure have been investigated and the results are presented.

  9. The exposure assessment of Rn-222 gas in the atmosphere(II)

    International Nuclear Information System (INIS)

    Ha, Chung Wo; Chang, Si Young; Seo, Kyung Won; Yoon, Yeo Chang; Kim, Jang Lyul; Yoon, Suk Chul; Chung, Rae Ik; Kim, Jong Soo; Park, Young Woong

    1991-01-01

    Dose assessment to inhalation exposure of indoor 222 Rn daughters in 12 residential areas in Korea has been performed by long term averaged radon concentrations measured with passive CR-39 radon cups. A simple mathematical lung dosimetry model based on the ICRP-30 was derived to estimate the indoor radon daughters exposure. The long term average indoor 222 Rn concentrations and corresponding equilibrium equivalent radon concentrations (EEC Rn ) in 12 areas showed a range of 33.82 ∼ 61.42 Bq.m -3 (median : 48.90 Bq.m -3 ) and of 13.53 ∼ 24.57 Bq.m -3 (median: 19.55 Bq.m -3 ), respectively. Reference dose conversion functions for evaluation of regional lung dose and effective dose equivalent for unit exposure to EEC Rn have been derived for an adult. The effective dose equivalent conversion factor was estimated to be 1.07 x 10 -5 mSv/Bq.h.m -3 and this conversion factor agreed well with that recommended by the ICRP and UNSCEAR report. The annual average dose equivalents(H) to Tracheo-Bronchial and Pulmonary region of the lung, and total lung from exposure to measured EEC Rn were estimated to be 17.52 mSv.y -l , 3.35 mSv.y -l and 20.90 mSv.y -1 , respectively, and the resulting effective dose equivalent(H E ) was estimated to be 1.25 mSv.y -l , which is almost 50% of the natural radiation exposure of 2.40 mSv.y -l reported by the UNSCEAR. (Author)

  10. Assessing the risks of Rn exposure: the influence of cigarette smoking

    International Nuclear Information System (INIS)

    Ginevan, M.E.; Mills, W.A.

    1986-01-01

    The principal hazard associated with exposure to Rn progeny is lung cancer. However, most lung cancer is caused by smoking, which raises a dual problem of deriving Rn-progeny cancer risk estimates from miner populations who, in large part, are smokers and applying these estimates to the general population whose lung cancer risk, in large part, is determined by smoking habits. We examine current risk estimates for Rn-progeny-induced lung cancer using a cohort life table methodology. Estimates of lifetime probability of dying of lung cancer, average loss in life expectancy due to premature lung cancer death, and loss in life expectancy per premature lung cancer death are calculated for the general population for 1969 and 1978, nonsmokers, and smokers. These calculations demonstrate that such risk estimates are affected by smoking, and by trends in smoking habits, in several ways. Major smoking-related factors in this interaction are the proportion of smokers in the mining population used to derive lung cancer risk estimates, the proportion of smokers in the ''general'' population, and the assumed interaction (additive or multiplicative) between lung cancer risk, Rn-progeny exposure, and smoking history. At this time the data are not sufficient to recommend one particular modeling approach. However, our evaluation demonstrates that broad statements about Rn-progeny lung cancer risk such as x cancers/10(6) person working level month, while informative, are incomplete without further specification. Any risk assessment must clearly state the population assumed to be at risk and the risk model assumed to be operating. Finally, the caveats appropriate to these assumptions should also be enunciated

  11. Non-occupational radiation exposures from 222Rn and daughters to residents of Grand Junction, Colorado

    International Nuclear Information System (INIS)

    Spitz, H.B.; Cohen, N.; Wrenn, M.E.

    1975-01-01

    Six individuals from GRAND Junction, Colorado were examined for 210 Pb body burdens as a result of living in homes where concentrations of 222 Rn were elevated due to the presence of uranium mill tailings beneath the building foundation. In vivo detection for 210 Pb using three NaI--CsI (Tl) thin crystals in the standard NYU head geometry identified two persons with estimaed body burdens above 1.1 nCi. Bioassay for 210 Pb was also performed to compare with the in vivo analysis and to further substantiate the relationship between 210 Pb in bone, blood, and urine. estimates of exposure in cumulative working level months (CWLM), range 85 to 566 CWLM, were used to calculate expected body burdens of 210 Pb. The NYU continuous readout radon monitor provided diurnal measurements of 222 Rn in the homes of the volunteer subjects so that, considering assumptions about ventilation and residence times, actual exposures could be determined. (U.S.)

  12. Estimation of exposure to 222Rn from the excretion rates of 21πPb

    International Nuclear Information System (INIS)

    Holtzman, R.B.; Rundo, J.

    1981-01-01

    A model is proposed with which estimates of exposure to 227 Rn and its daughter products may be made from urinary excretion rates of 210 Pb. It is assumed that 20% of all the 210 Pb inhaled reaches the blood and that 50% of the endogenous excretion is through the urine. The estimates from the model are compared with the results of measurements on a subject residing in a house with high levels of radon. Whole body radioactivity and excretion data were consistent with the model, but the estimates of exposure (WL) were higher than those measured with an Environmental Working Level Monitor

  13. Evaluation of the external exposure to Rn-222 progeny in air

    International Nuclear Information System (INIS)

    Ali, E.M.; Taha, T.M.; Gomaa, M.A.; El-Hussein, A.M.; Ahmed, A.A.

    2003-01-01

    The aim of this paper is to evaluate the Rn-222 progeny annual effective dose, skin dose and effective doses to different organs such as Gonad, Lung, Red Marrow, Bone surface, Thyroid, and the Remainder. Dose Coefficients of external exposure to Rn-222 in air was used in mSv s/Bqm -3 to calculate the organ doses. The study was monitored for two places, Nuclear Research Center and Al-Minia University. We have confirmed that the inhalation modes, sleep, sitting, light and heavy exercise influence the activity inhalation rate Bq/hr. It varies from 0.3 to 39.6 Bq/hr., the organ doses of Pb-214 is higher than Bi-214/Po-214 and Po-218 respectively in the case of the organ dose relative to environmental media

  14. Assessment of {sup 222}Rn occupational exposure at IPEN nuclear materials storage site, SP, Brazil; Avaliacao da exposicao ocupacional ao {sup 222}Rn no galpao da Salvaguardas do IPEN, SP

    Energy Technology Data Exchange (ETDEWEB)

    Caccuri, Lilian Saueia

    2007-07-01

    In this study it was assessed the occupational exposure to {sup 222}Rn at IPEN, SP, Brazil, nuclear materials storage site through the committed effective dose received by workers exposed to this radionuclide. The radiation dose was calculated through the radon concentrations at nuclear materials storage site. Radon concentrations were determined by passive detection method with solid state nuclear detectors (SSNTD). The SSNTD used in this study was the polycarbonate Makrofol E; each detector is a small square plastic of 1 cm{sup 2}, placed into a diffusion chamber type KFK. It was monitored 14 points at nuclear materials storage site and one external point, over a period of 21 months, changing the detectors every three months, from December 2004 to September 2006. The {sup 222}Rn concentrations varied from 196 {+-} 9 and 2048 {+-} 81 Bq{center_dot}m{sup -3}. The committed effective dose due to radon inhalation at IPEN nuclear materials storage site was obtained from radon activity incorporated and dose conversion factor, according to International Commission on Radiological Protection procedures. The effective committed dose received by workers is below 20 mSv{center_dot}y{sup -1}. This value is suggested as an annual effective dose limit for occupational exposure by ICRP 60. (author)

  15. Exposures to 222Rn and its progeny derived from implanted 210Po activity

    International Nuclear Information System (INIS)

    Nikezic, D.; Yu, K.N.

    2006-01-01

    The Jacobi room model was applied to study the relative contributions from the unattached and attached fractions to the implanted activity of 210 Po. It was found that under normal conditions, about 85% of the implantation was due to the unattached fraction. Sensitivity analysis was performed to identify the most important factors that influence the deposition and implantation of radon progeny. The main factors affecting the incorporation of 210 Po are the attachment rate, deposition rate of unattached progeny and the surface to volume ratio of the room. The calibration curves, which related the 210 Po activity per unit surface area to the concentrations of 222 Rn and of the radon progeny, were determined as functions of exposure times. The implanted activity is found to distribute close to a lognormal distribution. For an exposure of 20 years, the distribution has a geometric standard deviation of 2.2 and a geometric mean of 0.023Bq/m 2 /(Bq/m 3 ). The last value is considered as the calibration coefficient of the glass response in terms of the implanted 210 Po activity per unit surface area per unit concentration of 222 Rn for an exposure period of 20 years

  16. Prototype exposure chamber of radon for animal experiments

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Yuji; Koizumi, Akira; Yonehara, Hidenori; Shimo, Michikuni; Inaba, Jiro [National Institute of Radiological Sciences, Chiba (Japan)

    1998-12-31

    To evaluate a dose conversion factor from the `Working Level of Month` (WLM) of radon to the absorbed dose (mGy), the quality of radon and its progeny was assessed, and exposures controlled for each deposition region were planed as follows: 1) exposure of radon gas to the entire respiratory tract, 2) exposure of `unattached` fractions to the upper respiratory tract, 3) exposure of `attached` fractions onto ultrafine particles to the deep lung, 4) exposure of `attached` fractions onto fine particles to the lower respiratory tract, 5) exposure of `attached` fractions onto coarse particles to the upper respiratory tract. In this preliminary study, a prototype exposure system of radon and its progeny for small rodents was designed. A whole body exposure chamber with a volume of about 0.5 m{sup 3} was used, which it held 20 rats. The aging and mixing chamber separated by the exposure chamber had a volume of about 1 m{sup 3}. As career aerosols of radon progeny, carnauba wax aerosols as solid particles, DOS aerosols as liquid particles and NaCl aerosols as hygroscopic particles were selected. These aerosols generated using a vaporization-condensation method and/or an electrical classification method were almost monodisperse with {sigma}{sub g} of <1.2. The monitoring data on biologically related gases showed an importance in the oxygen injection system and the carbon dioxide absorption system. (author)

  17. Internal exposure to 222Rn progeny of the underground workers in Bulgarian uranian mines in 1958-1989

    International Nuclear Information System (INIS)

    Dimitrov, M.; Presiyanov, D.

    1998-01-01

    The results of more than 50000 measurements of 222 Rn and 22R n progeny measurements made in 1958-1989 in 9 large Bulgarian uranium mines (namely: '9 septemvri', 'Seslavci', 'Eleshnitsa 1, 2, 3', 'Smolyan', 'Byalata voda', 'Balkan' and 'Smolyanovtsi') have been summarized. The average WLM-exposures have been determined for each of the mines. The results make possible to estimate internal WLM exposure of any miner, provided that his underground working experience is known

  18. Dosimetry, instrumentation and exposure chambers for dc magnetic field studies

    International Nuclear Information System (INIS)

    Tenforde, T.S.

    1979-03-01

    The principal objective of this report is to describe in detail an exposure chamber that was developed at the Lawrence Berkeley Laboratory for automated, noninvasive studies of rodent physiology during exposure to high DC magnetic fields. A second objective is to discuss some of the unique instrumentation problems that must be overcome in order to record bioelectric signals from laboratory animals in the presence of a magnetic field. Finally, a description will be given of the various dosimetry techniques that can be employed for quantitation of magnetic field strength

  19. Reasonable selection of automatic exposure density compensation of ionization chamber

    International Nuclear Information System (INIS)

    Tian Fuqiang; Nie Shikun; Wang Zhihong; Zeng Jianhua; Cheng Guanxun; Xiang Qian

    2000-01-01

    Objective: To introduce and discuss the methods of reasonable selection of the automatic exposure density compensation of ionization chamber to provide important references for clinic radiograph and improve the quality of images. Methods: X-ray machines with ionization chamber automatic exposure control system were used in this study. Compared with the standard baseline of the normal density of the object radio-graphed, the reasonable ionization chamber density compensation (IDC) was chosen and compared with the radiograph without IDC through a water model test and density measurement. Results: There was no significant difference between two groups (100 films each) which were randomly divided to the group with or without IDC, but there was statistically significant difference in the special groups. Conclusion: To select suitable IDC is very important for guaranteeing radiographic quality, moreover, to establish a suitable kV is also necessary, usually it is 10 to 20 kV higher than the optioned kV. The relative factors must be fixed relatively and be matched correctly

  20. 222 Rn exposure assessment in the caves of Parque Estadual Turistico do Alto Ribeira (PETAR)

    International Nuclear Information System (INIS)

    Alberigi, Simone

    2006-01-01

    In the present work, radon concentrations in six caves of PETAR - Parque Estadual Turistico do Alto Ribeira (High Ribeira River Touristic State Park) were carried out with Makrofol E solid state nuclear track detectors (SSNTD) and used to assess the annual effective dose received by regional tour guides. The park has four visitation centers: Santana, Ouro Grosso, Caboclos e Casa de Pedra and receives nearly 40,000 people annually. The caves evaluated were Couto, Agua Suja, Laje Branca, Morro Preto and Santana, from Santana center and Alambari de Baixo from Ouro Grosso center, for being the most frequently visited caves. The exposure period of the SSNTD was, at least, three months, over a period of 26 months, from October 2003 to November 2005.The 222 Rn concentrations lay in a range from 153 Bq.m -3 to 6607 Bq.m -3 and we observed that, in general, for chilly weather, the radon levels decrease. The annual effective dose, considering the most realistic scenario, with geometric mean concentrations, an equilibrium factor of 0.5 and annual exposure time for each cave, varied from 0.2 mSv.a -1 for the Couto cave, strongly ventilated, to 4.0 mSv.a -1 for the Santana cave, the most frequently visited and no external communication. For the worst scenario, with arithmetic mean concentrations, equilibrium factor 1 and annual exposure time for all caves, the annual effective dose was 16.1 mSv.a -1 . All assessed effective doses received by the tour guides are bellow 20 mSv.a -1 suggested as an annual effective dose limit for occupational exposure by the International Commission of Radiological Protection (ICRP 60, 1990). (author)

  1. Simultaneous determination of Rn-220 and Rn-222 concentrations in atmospheres by cellulose nitrate ionographic detectors

    International Nuclear Information System (INIS)

    Lobao, N.

    1977-01-01

    A method for the indoor determination of airborne radon and radon daughters is described, based in the utilization of cellulose nitrate (CN) ionographic detectors (LR-115-Kodak-Pathe) These track-etching detectors are coupled to an air sample and to a difusion chamber respectively. In the first system ambient air is pulled through a fiber glass filter for collection of airborne radon daughters (Flow: 230 ml/min). In the second system, the cellulose nitrate detectors is coupled/min). In the second system, the cellulose nitrate detectors is coupled to a difusion chamber electrostatic precipitator arrangement. Here the CN detector will register only the alpha particles given off by the decay products of Rn-222 formed within the sensitive volume of electrostatic precipitator. The construction of calibration curves for the two systems using adequate steady-state concentrations of Rn-220 and Rn-222 in an exposure chamber (1 cubic meter), will allow the use of the system for measurement of measurement of averaged integrated radon concentrations. The CN attached to the CN attached to the air sampler is exposed in the reference atmosphere with and without a mylar filter for discrimination of alpha particles with different energies Field sampling indicated however, that efficiency of the two systems are still low for the measurement of environmental levels of Rn-220 and Rn-222 within houses of the AENR, recommendations for efficienty improvement of the system are proposed [pt

  2. A re-circulated toxicity exposure chamber to evaluate hydrocarbon dispersions

    International Nuclear Information System (INIS)

    Fuller, C.B.; Bonner, J.S.; Bujnoch, J.D.; Ussery, S.F.; Arrambide, G.; Sterling, M.C.

    2002-01-01

    Traditional toxicology methods are not suitable for evaluating chemically dispersed oil which exists mostly as a colloidal suspension and as dissolved fractions. A new toxicity exposure chamber was designed with separate chambers for scaled mixing and organism exposure. The design of the chamber incorporates continuous recirculation between the mixing and exposure chamber and an upward flow in the exposure chamber. The toxicity exposure system incorporates scalable and quantitative mixing inputs with real time particle size analysis and traditional petrochemistry methods to characterize the exposure regime. Changes in dispersion were successfully translated to the organism exposure regime. The study determined the petroleum toxicity with a juvenile marine test species. Low control mortality demonstrated the usefulness of the method for testing toxicity of colloidal oil suspensions. 20 refs., 1 tab., 4 figs

  3. Inhalation exposures due to radon and thoron ((222)Rn and (220)Rn): Do they differ in high and normal background radiation areas in India?

    Science.gov (United States)

    Mishra, Rosaline; Sapra, B K; Prajith, R; Rout, R P; Jalaluddin, S; Mayya, Y S

    2015-09-01

    In India, High Background Radiation Areas (HBRAs) due to enhanced levels of naturally occurring radionuclides in soil (thorium and, to a lesser extent, uranium), are located along some parts of the coastal tracts viz. the coastal belt of Kerala, Tamilnadu and Odisha. It is conjectured that these deposits will result in higher emissions of radon isotopes ((222)Rn and (220)Rn) and their daughter products as compared to Normal Background Radiation Areas (NBRAs). While the annual external dose rates contributed by gamma radiations in these areas are about 5-10 times higher, the extent of increase in the inhalation dose rates attributable to (222)Rn and (220)Rn and their decay products is not well quantified. Towards this, systematic indoor surveys were conducted wherein simultaneous measurements of time integrated (222)Rn and (220)Rn gas and their decay product concentrations was carried out in around 800 houses in the HBRAs of Kerala and Odisha to estimate the inhalation doses. All gas measurements were carried out using pin-hole cup dosimeters while the progeny measurements were with samplers and systems based on the Direct radon/thoron Progeny sensors (DRPS/DTPS). To corroborate these passive measurements of decay products concentrations, active sampling was also carried out in a few houses. The results of the surveys provide a strong evidence to conclude that the inhalation doses due to (222)Rn and (220)Rn gas and their decay products in these HBRAs are in the same range as observed in the NBRAs in India. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. 222Rn in wine cellars in Hungary

    International Nuclear Information System (INIS)

    Csige, I.; Hunyadi, I.; Szerbin, P.; Juhasz, L.

    2004-01-01

    We measured seasonal average 222 Rn activity concentrations in the air of 60 wine cellars in the Tokajhegyalja and Villany wine regions of Hungary using Radamon type etched track radon detectors. The exposure period was 3 months, matching the seasons of 2003-2004. We also used an ionization chamber-type continuous 222 Rn-monitor (AlphaGUARD PQ222, Genitron Instruments, Germany) to study temporal variations of 222 Rn activity concentration in a selected wine cellar in the Tokajhegyalja wine region. This instruments also recorded temperature, atmospheric pressure and relative humidity data. The etched track detector data revealed that the 222 Rn activity concentrations in the air of wine cellars spread over a wide range, from the ambient outdoor concentration of 6 Bq.m -3 up to 6 kBq.m -3 characteristic of natural caves. The temporal variation of 222 Rn activity concentration in the air of the selected cellar varied inversely with the variation of the atmospheric pressure. Earlier we observed similar phenomena in natural karstic caves connected to the surface with vertical shafts only. This suggests that relatively large volume of pore space of the embedding rock communicates with the volume of the cellar induced by the variation of the atmospheric pressure

  5. Internal exposure from building materials exhaling (222)Rn and (220)Rn as compared to external exposure due to their natural radioactivity content.

    Science.gov (United States)

    Ujić, Predrag; Celiković, Igor; Kandić, Aleksandar; Vukanac, Ivana; Durasević, Mirjana; Dragosavac, Dusan; Zunić, Zora S

    2010-01-01

    The main scope of this paper is to point out the importance of introducing radon and thoron exhalation measurements from building materials in the regulating frame. Currently (2009), such a regulation of this kind of exposure is not explicitly included in the Serbian regulating network. To this end, this work reports concentration measurements of (226)Ra, (232)Th and (40)K and radon and thoron exhalation rates from building materials used in Serbia. Following detailed analysis, it was noticed that both internal exposures to radon and/or thoron exhaling from building materials may exceed external exposures to their precursors contained therein.

  6. Randomization of grab-sampling strategies for estimating the annual exposure of U miners to Rn daughters.

    Science.gov (United States)

    Borak, T B

    1986-04-01

    Periodic grab sampling in combination with time-of-occupancy surveys has been the accepted procedure for estimating the annual exposure of underground U miners to Rn daughters. Temporal variations in the concentration of potential alpha energy in the mine generate uncertainties in this process. A system to randomize the selection of locations for measurement is described which can reduce uncertainties and eliminate systematic biases in the data. In general, a sample frequency of 50 measurements per year is sufficient to satisfy the criteria that the annual exposure be determined in working level months to within +/- 50% of the true value with a 95% level of confidence. Suggestions for implementing this randomization scheme are presented.

  7. Ion recombination characteristics of the MDH 10X5-6 ionisation chamber under continuous exposure

    International Nuclear Information System (INIS)

    Cerra, F.

    1982-01-01

    Volume recombination of the induced ionization in an X-ray ionization chamber is an important factor affecting the collection efficiency of the charge when such chambers are operated at atmospheric pressure. The volume recombination process is also dependent on the X-ray exposure rate. The theory for recombination in a cylindrical ionization chamber is shown to be in agreement with experimental measurements. For the MDH 10X5-6 cylindrical ionization chamber, the recombination loss is unimportant at exposure rates consistent with its intended usage. (U.K.)

  8. Bubble chamber film exposure for measurement by HPD

    International Nuclear Information System (INIS)

    Oxley, A.J.

    1978-03-01

    It is not easy for HPD measuring machines to detect tracks of low contrast in film from bubble chambers with bright-field illumination. Some of the basic aspects and limitations are considered in this paper. (author)

  9. Epidemiological analysis of the relationship between exposure to Rn progeny, smoking and bronchogenic carcinoma in the U-mining population of the Colorado Plateau--1960-1980

    International Nuclear Information System (INIS)

    Saccomanno, G.; Yale, C.; Dixon, W.; Auerbach, O.; Huth, G.C.

    1986-01-01

    This study investigates the relationship between exposure to radioactive Rn decay products during U mining and milling operations, cigarette smoking and age, on the incidence and mortality rates of lung cancer among U workers of the Colorado Plateau during the 20-yr period from 1960-1980. A case control sample was taken from an extensive data base of 9,817 men accumulated by one author (Saccomanno). A preliminary hypothesis had been made that a possible synergistic or at least additive effect might exist when the risk factors of exposure to Rn decay products and smoking were simultaneously present. This study would seem to indicate that a synergistic effect is not present. In this work, a total of 489 cases, defined as men having a cytological diagnosis of moderate or worse atypical squamous-cell metaplasia, and a random sample of 992 ''non-cases'' were selected retrospectively from the dynamic cohort of workers. These data analyzed from three different perspectives indicate significant effects due to Rn-decay-product exposure in excess of the expected incidence due to age and smoking history. The data also indicate that Rn-decay-product accumulations of less than 300 working level months (WLM) is not carcinogenic in non-cigarette smokers

  10. X-ray detector for automatic exposure control using ionization chamber filled with xenon gas

    CERN Document Server

    Nakagawa, A; Yoshida, T

    2003-01-01

    This report refers to our newly developed X-ray detector for reliable automatic X-ray exposure control, which is to be widely used for X-ray diagnoses in various clinical fields. This new detector utilizes an ionization chamber filled with xenon gas, in contrast to conventional X-ray detectors which use ionization chambers filled with air. Use of xenon gas ensures higher sensitivity and thinner design of the detector. The xenon gas is completely sealed in the chamber, so that the influence of the changes in ambient environments is minimized. (author)

  11. Development, implementation and utilization of 210Pb in vivo measurement techniques as indicator of human being exposure to 222Rn - evaluation of associated parameters

    International Nuclear Information System (INIS)

    Dantas, Ana Leticia Almeida

    2005-01-01

    Radon and its decay products are present in the atmosphere and are the most important contributors for the internal exposure of humans to natural radiation. The execution of in vivo measurements of 210 Pb in the population and in individuals occupationally exposed in underground mines has been studied and recommended as one of the procedures for the estimation of the exposure to 222 Rn. The metabolism of 210 Pb and its distribution within the human body, mainly deposited in the bone tissue, suggests the regions of skull and knee as the most suitable for the in vivo monitoring of such radionuclide. A radiological survey in non uranium mines in Brazil indicated that an underground coal mine in the State of Parana, in the south of Brazil, had high radon concentration. The aim of this work were: (1) To investigate whether underground coal miners may also have elevated 210 Pb in the skeleton as a result of occupational exposure to radon in the coal mine; (2) To estimate the committed equivalent dose and the committed effective dose in different incorporation scenarios using a computer code. The calibration and the in vivo measurements of underground coal miners were performed in the IRD-CNEN Whole Body Counter shielded room using an array of four high resolution germanium detectors. The detection system was positioned at the head and knee geometries. The minimum detectable quantity of 210 Pb in the skeleton using this methodology was (50 Bq) and the positive results were verified using a mathematical method that applies a moving median smoothing function to the total spectrum for each measurement. In vivo measurements of 210 Pb in 6 out of the 32 underground coal miners ranged between 83 Bq and 164 Bq suggesting that these workers received significant occupational cumulative exposure to 222 Rn. The simulation of some exposure patterns of 222 Rn progeny and 210 Pb incorporation showed that the most important contribution for 210 Pb skeleton deposition was the intake of

  12. Quality assurance for radon exposure chambers at the National Air and Radiation Environmental Laboratory, Montgomery, Alabama

    Energy Technology Data Exchange (ETDEWEB)

    Semler, M.O.; Sensintaffar, E.L. [National Air and Radiation Environmental Laboratory, Montgomery, AL (United States)

    1993-12-31

    The Office of Radiation and Indoor Air, U.S. Environmental Protection Agency (EPA), operates six radon exposure chambers in its two laboratories, the National Air and Radiation Environmental Laboratory (NAREL) in Montgomery, Alabama, and the Las Vegas Facility, Las Vegas, Nevada. These radon exposure chambers are used to calibrate and test portable radon measuring instruments, test commercial suppliers of radon measurement services through the Radon Measurement Proficiency Program, and expose passive measurement devices to known radon concentrations as part of a quality assurance plan for federal and state studies measuring indoor radon concentrations. Both laboratories participate in national and international intercomparisons for the measurement of radon and are presently working with the National Institute of Standards and Technology (NIST) to receive a certificate of traceability for radon measurements. NAREL has developed an estimate of the total error in its calibration of each chamber`s continuous monitors as part of an internal quality assurance program. This paper discusses the continuous monitors and their calibration for the three chambers located in Montgomery, Alabama, as well as the results of the authors intercomparisons and total error analysis.

  13. A prospective assessment of the sup 2 sup 1 sup 0 Po surface collection for estimating sup 2 sup 2 sup 2 Rn exposure

    CERN Document Server

    Fitzgerald, B

    2000-01-01

    Previous studies have examined the utility of measuring the embedded sup 2 sup 1 sup 0 Po in solid materials as an indicator of long-term sup 2 sup 2 sup 2 Rn exposure. However, in those studies, existing surfaces were employed. In this prospective study, pairs of glass surfaces were placed in homes around the United States along with an LR-115-II-etched track radon detector for each piece of glass. A subset of these glass samples has been analyzed for sup 2 sup 1 sup 0 Po activity. The results of measurements on a subset of samples are presented. The independent sup 2 sup 2 sup 2 Rn measurements are compared with the sup 2 sup 1 sup 0 Po measurements and a relationship is obtained between the two results using a model for the accumulation of activity within an enclosed space. The data are interpreted in terms of (a) the usefulness of the sup 2 sup 1 sup 0 Po measurements as a long-term sup 2 sup 2 sup 2 Rn detector and (b) the value of a new interpretation scheme to make retrospective assessments of the sup ...

  14. Evaluation of occupational exposure in a underground coal mine by environmental measures of 222Rn and in vivo measurements of 210Pb in bones

    International Nuclear Information System (INIS)

    Dantas, A.L.A.; Veiga, L.H.S.; Dantas, B.M.; Melo, V.P.

    2005-01-01

    A radiological survey performed in an underground coal mining in the State of Parana, southern Brazil, has indicated the occurrence of high levels of concentration of radon and its decay products. The levels of 222 Rn concentration measured in the basement of this mine, in the period from 1999 to 2003 ranged from 2000 to 7000 Bq m -3 . It is estimated, for these workers, an average annual exposure of 2.1 WLM ranging from 0.2 to 7.2 WLM. A retrospective mortality study conducted with 2856 miners of this mining indicated a risk of lung cancer mortality greater than the one expected for the male population of the State. In this study the cumulative exposure to radon cannot be estimated since there was no radon measures in other periods. In this way, the cumulative exposure can be evaluated by through 210 Pb activities monitored in the skeleton. The measures of 210 Pb in skeleton ranged from 83 to 164 Bq, indicating that these workers were significantly exposed to 222 Rn. These results show that cumulative exposure to radon has been higher than estimated based on recent measures of the activity concentration of radon in the workplace and is compatible with the risk determined in the epidemiological study

  15. Responsiveness to timothy grass pollen in individuals without known natural exposure in an allergen challenge chamber.

    Science.gov (United States)

    Ramirez, Daniel A; Andrews, Charles P; Rather, Cynthia G; Jacobs, Robert L

    2015-03-01

    The responsiveness to a nonendemic grass species is unknown and cannot be research without an allergen challenge chamber. To determine the clinical responsiveness to timothy grass pollen (TGP) in participants without known natural exposure in an allergen challenge chamber (ACC). Of the 26 screened participants, 22 met screening criteria and completed the 2 chamber exposures. The study consisted of an initial screening visit that included a blood draw for serum specific IgE (ssIGE) to Bermuda grass pollen and TGP followed by a 4½-day run-in phase and two 3-hour ACC exposure visits. This study was performed early in the first week of December 2013, when no seasonal pollens were detected in San Antonio, Texas. Symptom scores were recorded at baseline and every 30 minutes. Of the 26 screened participants, 22 met the screening criteria and completed the 2 chamber exposures. Thirteen participants had always lived in South Texas without natural exposure, and 9 had previously lived in areas with TGP exposure. All participants tested positive to TGP and Bermuda grass pollen. Twelve and 13 of 22 had positive ssIgE test results to Timothy and Bermuda allergens, respectively, with 11 having positive results for both allergens. There were strong correlations among skin prick test size, a positive ssIgE test result, and high symptoms from TGP exposure. There was little difference in symptoms between those who had lived their entire lives in South Texas and those who had lived elsewhere. In Texas, where exposure to TGP is minimal, strongly positive SPT and ssIgE test results were predictors of high symptoms to TGP exposure. Never exposed participants in South Texas reacted to TGP similar to those who had previous natural exposure, suggesting that in vivo cross-reactivity may be higher than predicted by prior in vitro data and may allow the use in clinical trials of allergens not endemic to the locale of an ACC. Copyright © 2015 American College of Allergy, Asthma & Immunology

  16. A Radio Frequency Radiation Exposure System for Rodents based on Reverberation Chambers.

    Science.gov (United States)

    Capstick, Myles; Kuster, Niels; Kuehn, Sven; Berdinas-Torres, Veronica; Gong, Yijian; Wilson, Perry; Ladbury, John; Koepke, Galen; McCormick, David L; Gauger, James; Melnick, Ronald L

    2017-08-01

    In this paper we present the novel design features, their technical implementation, and an evaluation of the radio Frequency (RF) exposure systems developed for the National Toxicology Program (NTP) of the National Institute of Environmental Health Sciences (NIEHS) studies on the potential toxicity and carcinogenicity of 2nd and 3rd generation mobile-phone signals. The system requirements for this 2-year NTP cancer bioassay study were the tightly-controlled lifetime exposure of rodents (1568 rats and 1512 mice) to three power levels plus sham simulating typical daily, and higher, exposures of users of GSM and CDMA (IS95) signals. Reverberation chambers and animal housing were designed to allow extended exposure time per day for free-roaming individually-housed animals. The performance of the chamber was characterized in terms of homogeneity, stirred to unstirred energy, efficiency. The achieved homogeneity was 0.59 dB and 0.48 dB at 900 and 1900 MHz respectively. The temporal variation in the electric field strength was optimized to give similar characteristics to that of the power control of a phone in a real network using the two stirrers. Experimental dosimetry was performed to validate the SAR sensitivity and determine the SAR uniformity throughout the exposure volume; SAR uniformities of 0.46 dB and 0.40 dB, respectively, for rats and mice were achieved.

  17. {sup 222} Rn exposure assessment in the caves of Parque Estadual Turistico do Alto Ribeira (PETAR); Avaliacao da exposicao ao {sup 222} Rn nas cavernas do Parque Estadual Turistico do Alto Ribeira (PETAR)

    Energy Technology Data Exchange (ETDEWEB)

    Alberigi, Simone

    2006-07-01

    In the present work, radon concentrations in six caves of PETAR - Parque Estadual Turistico do Alto Ribeira (High Ribeira River Touristic State Park) were carried out with Makrofol E solid state nuclear track detectors (SSNTD) and used to assess the annual effective dose received by regional tour guides. The park has four visitation centers: Santana, Ouro Grosso, Caboclos e Casa de Pedra and receives nearly 40,000 people annually. The caves evaluated were Couto, Agua Suja, Laje Branca, Morro Preto and Santana, from Santana center and Alambari de Baixo from Ouro Grosso center, for being the most frequently visited caves. The exposure period of the SSNTD was, at least, three months, over a period of 26 months, from October 2003 to November 2005.The {sup 222}Rn concentrations lay in a range from 153 Bq.m{sup -3} to 6607 Bq.m{sup -3} and we observed that, in general, for chilly weather, the radon levels decrease. The annual effective dose, considering the most realistic scenario, with geometric mean concentrations, an equilibrium factor of 0.5 and annual exposure time for each cave, varied from 0.2 mSv.a{sup -1} for the Couto cave, strongly ventilated, to 4.0 mSv.a{sup -1} for the Santana cave, the most frequently visited and no external communication. For the worst scenario, with arithmetic mean concentrations, equilibrium factor 1 and annual exposure time for all caves, the annual effective dose was 16.1 mSv.a{sup -1}. All assessed effective doses received by the tour guides are bellow 20 mSv.a{sup -1} suggested as an annual effective dose limit for occupational exposure by the International Commission of Radiological Protection (ICRP 60, 1990). (author)

  18. Standards, calibration and quality assurance of 222Rn measurements in Sweden

    International Nuclear Information System (INIS)

    Falk, R.; Hagberg, N.; Mjoenes, L.; Moere, H.; Nyblom, L.; Swedjemark, G.A.

    1994-01-01

    Inhaled decay products of 222 Rn are the dominant components of the natural radiation exposure to the general population. Limits have been introduced in Sweden, and recommendations were made in 1980 for decreasing indoor 222 Rn concentration. The need for the coordinated calibration of measuring instruments as well as for quality assurance was obvious for both health and economic reasons. 222 Rn measurements in Sweden are based on standards traceable to the National Institute of Standard and Technology (NIST) through the use of standard reference material 226 Ra. Standards for both 222 Rn and short-lived 222 Rn progeny are described together with the reference instrument adopted for these studies. The calibration of field instruments was performed in a ''radon room'', a climate chamber in which it is possible to vary and monitor the concentration of 222 Rn as well as other characteristics of the indoor air such as temperature, humidity, ventilation rate and aerosol concentration. The rules and regulations for field measurements imply a calibration of the instruments yearly, as well as accreditation and training for the companies that carry out the measurements. Examples are given of the official measurement protocols used for the different types of instruments. (orig.)

  19. Evaluation of automatic exposure control system chamber for the dose optimization when examining pelvic in digital radiography.

    Science.gov (United States)

    Kim, Sung-Chul; Lee, Hae-Kag; Lee, Yang-Sub; Cho, Jae-Hwan

    2015-01-01

    We found a way to optimize the image quality and reduce the exposure dose of patients through the proper activity combination of the automatic exposure control system chamber for the dose optimization when examining the pelvic anteroposterior side using the phantom of the human body standard model. We set 7 combinations of the chamber of automatic exposure control system. The effective dose was yielded by measuring five times for each according to the activity combination of the chamber for the dose measurement. Five radiologists with more than five years of experience evaluated the image through picture archiving and communication system using double blind test while classifying the 6 anatomical sites into 3-point level (improper, proper, perfect). When only one central chamber was activated, the effective dose was found to be the highest level, 0.287 mSv; and lowest when only the top left chamber was used, 0.165 mSv. After the subjective evaluation by five panel members on the pelvic image was completed, there was no statistically meaningful difference between the 7 chamber combinations, and all had good image quality. When testing the pelvic anteroposterior side with digital radiography, we were able to reduce the exposure dose of patients using the combination of the top right side of or the top two of the chamber.

  20. Thoron (RN-220) interference in the determination of RN-222 exhalation rate of soils

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, Déric S.; Farias, Emerson E.G.; Santos, Mariana L.O.; Silva, Karolayne E.M.; Hazin, Clovis A.; França, Elvis J., E-mail: emersonemiliano@yahoo.com [Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Souza Neto, João A., E-mail: adauto@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Geologia

    2017-07-01

    The transport of Rn-222 from the soil to the atmosphere known as exhalation is influenced by meteorological conditions and soil geophysical parameters. In closed and poorly ventilated rooms, this radioactive gas can reach high activity concentrations, in which the energy of alpha particles released by this radionuclide and its progeny is the second leading cause of lung cancer. Soil exhalation rate is an important parameter for assessing human health risks associated with radon. For radon determination using an exhalation chamber, an ionization chamber detector is used to count the electrical pulses generated by the interaction between the alpha particles produced by Rn-222 and its progeny and the air inside the chamber. In this work, the interference of thoron (Rn-220) in the determination of soil exhalation rate of Rn-222 was studied. For this, the RadonBOX exhalation chamber and the AlphaGuard ionization chamber detector were utilized for analyzing the same soil during two hours on different days under similar meteorological conditions. From zero up to approximately 2,400 s, the radon activity concentrations decreased. After 40 minutes, the radon concentrations started to increase, thereby allowing the calculation of soil exhalation rate. This initial decreasing could be explained by a high Rn-220 than Rn-222 presence in the soil, in which, because of its short half-life, after 40 minutes, most thoron present in the chamber has undergone so that the main alpha emitter become Rn-222. In order to confirm this, Rn-220 activity was estimated by the Ra-228 concentration in the soil determined after 30 days using High Resolution Gamma-Ray Spectrometry with HPGe detectors. Therefore, the thoron interference in the determination of soil radon exhalation rate was considered negligible after 40 minutes of measurement time for the analyzed soil. (author)

  1. Measurement of 222Rn and 220Rn exhalation rate from soil samples of Kumaun Hills, India

    Science.gov (United States)

    Semwal, Poonam; Singh, Kuldeep; Agarwal, T. K.; Joshi, Manish; Pant, Preeti; Kandari, Tushar; Ramola, R. C.

    2018-03-01

    The source terms, i.e., exhalation and emanation from soil and building materials are the primary contributors to the radon (222Rn)/thoron (220Rn) concentration levels in the dwellings, while the ecological constraints like ventilation rate, temperature, pressure, humidity, etc., are the influencing factors. The present study is focused on Almora District of Kumaun, located in Himalayan belt of Uttarakhand, India. For the measurement of 222Rn and 220Rn exhalation rates, 24 soil samples were collected from different locations. Gamma radiation level was measured at each of these locations. Chamber technique associated with Smart Rn Duo portable monitor was employed for the estimation of 222Rn and 220Rn exhalation rates. Radionuclides (226Ra, 232Th and 40K) concentrations were also measured in soil samples using NaI(Tl) scintillation based gamma ray spectrometry. The mass exhalation rate for 222Rn was varying between 16 and 54 mBq/kg/h, while the 220Rn surface exhalation rate was in the range of 0.65-6.43 Bq/m2/s. Measured gamma dose rate for the same region varied from 0.10 to 0.31 µSv/h. Inter-correlation of exhalation rates and intra-correlation with background gamma levels were studied.

  2. Characterization of a multiculture in-vitro cell exposure chamber for assessing the biological impact of diesel engine exhaust

    International Nuclear Information System (INIS)

    Asimakopoulou, Akrivi; Daskalos, Manos; Chasapidis, Leonidas; Akritidis, Theofilaktos; Vlachos, Nickolaos D; Papaioannou, Eleni; Konstandopoulos, Athanasios G

    2011-01-01

    In order to study the various health influencing parameters related to particulate as well as to gas-phase pollutants emitted by Diesel engine exhaust, there is an urgent need for appropriate sampling devices and methods for cell exposure studies and associated biological and toxicological tests. In a previous paper [1], a specific concept for a cell culture exposure chamber was introduced to allow the uniform exposure of cell cultures to diesel aerosols. In the present work, this cell culture exposure chamber is evaluated and characterized with state-of-the-art nanoparticles measurement instrumentation to assess the local deposition of soot aggregates on the cell cultures and any losses due to particle deposition on the cell culture exposure chamber walls, and in addition an upgraded Multiculture Exposure Chamber (MEC) for in vitro continuous flow cell exposure tests is introduced with improved, compared to the previous version, features. Analysis and design of the MEC employs CFD and true to geometry representations of soot particle aggregates.

  3. Radiological risk of actinon (/sup 219/Rn)

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, D.J.

    1981-12-01

    The research reported was designed to provide information on the following subjects: (1) development of the functional relations between exposure to the /sup 219/Rn decay chain and pertinent health effects; (2) specification of the circumstances under which a significant concentration of the decay chain may occur; (3) recommendation of an exposure standard which will provide protection of the public from significant elevation of health effects; and (4) an assessment of the impact of /sup 219/Rn on determinations of the concentration of the /sup 222/Rn decay chain and/or its precursors.

  4. Radiological risk of actinon (219Rn)

    International Nuclear Information System (INIS)

    Crawford, D.J.

    1981-12-01

    The research reported was designed to provide information on the following subjects: (1) development of the functional relations between exposure to the 219 Rn decay chain and pertinent health effects; (2) specification of the circumstances under which a significant concentration of the decay chain may occur; (3) recommendation of an exposure standard which will provide protection of the public from significant elevation of health effects; and (4) an assessment of the impact of 219 Rn on determinations of the concentration of the 222 Rn decay chain and/or its precursors

  5. Radon progeny distribution in cylindrical diffusion chambers

    International Nuclear Information System (INIS)

    Pressyanov, Dobromir S.

    2008-01-01

    An algorithm to model the diffusion of radioactive decay chain atoms is presented. Exact mathematical solutions in cylindrical geometry are given. They are used to obtain expressions for the concentrations of 222 Rn progeny atoms in the volume and deposited on the wall surface in cylindrical diffusion chambers. The dependence of volume fractions of 222 Rn progeny and chamber sensitivity on the coefficient of diffusion of 222 Rn progeny atoms in air is modeled.

  6. Experimental setup for radon exposure and first diffusion studies using gamma spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Maier, Andreas, E-mail: a.maier@gsi.de [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Beek, Patrick van [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Technical University Darmstadt, Hochschulstraße 6, 64289 Darmstadt (Germany); Hellmund, Johannes [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Durante, Marco [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Technical University Darmstadt, Hochschulstraße 6, 64289 Darmstadt (Germany); Schardt, Dieter; Kraft, Gerhard; Fournier, Claudia [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany)

    2015-11-01

    In order to measure the uptake and diffusion of {sup 222}Rn in biological material, an exposure chamber was constructed where cell cultures, biological tissues and mice can be exposed to {sup 222}Rn-activities similar to therapy conditions. After exposure, the material is transferred to a gamma spectrometer and the decay of {sup 214}Pb and {sup 214}Bi is analyzed. From the time kinetics of these decays the total amount of the initial {sup 222}Rn concentration can be calculated. In this paper the design and construction as well as first test measurements are reported.

  7. The distribution of 210Pb in human bone and its impact on methods for the retrospective estimation of 222Rn exposure from in vivo measurements.

    Science.gov (United States)

    Johnston, Peter N; Hult, Mikael; Gasparro, Joël; Martínez-Canet, María-José; Vasselli, Roberto; McKenzie, Raymond J; Solomon, Steven B; Lambrichts, Ivo

    2005-01-01

    It is possible to estimate radon exposure to man retrospectively by the in vivo measurement of the decay product (210)Pb, which accumulates in the bones. For in vivo methods, knowledge of the distribution of (210)Pb in the skeleton is needed to determine the optimal site for measurement, the skull or the knee. In this study the activity of (210)Pb in a variety of bone samples from 3 individuals have been measured in vitro using underground gamma-ray spectrometry. The individuals were unlikely to have had elevated intakes of Rn. These measurements give baseline data on the bone massic activity of (210)Pb. They show that the massic activity is similar for each of these people and there are similar massic activities of (210)Pb in the skull and the knee of the 2 individuals for which the skull was measured. Additionally for 2 of the individuals trabecular and cortical bone were separated and massic activities were found to be strongly correlated indicating that the (210)Pb is associated with the hydroxyapatite.

  8. The distribution of 210Pb in human bone and its impact on methods for the retrospective estimation of 222Rn exposure from in vivo measurements

    International Nuclear Information System (INIS)

    Johnston, Peter N.; Hult, Mikael; Gasparro, Jogl; Martinez-Canet, Maria-Jose; Vasselli, Roberto; McKenzie, Raymond J.; Solomon, Steven B.; Lambrichts, Ivo

    2005-01-01

    It is possible to estimate radon exposure to man retrospectively by the in vivo measurement of the decay product 210 Pb, which accumulates in the bones. For in vivo methods, knowledge of the distribution of 210 Pb in the skeleton is needed to determine the optimal site for measurement, the skull or the knee. In this study the activity of 210 Pb in a variety of bone samples from 3 individuals have been measured in vitro using underground γ-ray spectrometry. The individuals were unlikely to have had elevated intakes of Rn. These measurements give baseline data on the bone massic activity of 210 Pb. They show that the massic activity is similar for each of these people and there are similar massic activities of 210 Pb in the skull and the knee of the 2 individuals for which the skull was measured. Additionally for 2 of the individuals trabecular and cortical bone were separated and massic activities were found to be strongly correlated indicating that the 210 Pb is associated with the hydroxyapatite

  9. The distribution of {sup 210}Pb in human bone and its impact on methods for the retrospective estimation of {sup 222}Rn exposure from in vivo measurements

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, Peter N. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Department of Applied Physics, Royal Melbourne Institute of Technology, GPO Box 2476V, Melbourne 3001 (Australia); Hult, Mikael [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium)]. E-mail: mikael.hult@cec.eu.int; Gasparro, Jogl [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Martinez-Canet, Maria-Jose [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Vasselli, Roberto [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); McKenzie, Raymond J. [Department of Applied Physics, Royal Melbourne Institute of Technology, GPO Box 2476V, Melbourne 3001 (Australia); Solomon, Steven B. [Australian Radiation Protection and Nuclear Safety Agency, Lower Plenty Road, Yallambie 3085 (Australia); Lambrichts, Ivo [Department of Histology, Limburg University Centrum (LUC), Diepenbeek (Belgium)

    2005-07-01

    It is possible to estimate radon exposure to man retrospectively by the in vivo measurement of the decay product {sup 210}Pb, which accumulates in the bones. For in vivo methods, knowledge of the distribution of {sup 210}Pb in the skeleton is needed to determine the optimal site for measurement, the skull or the knee. In this study the activity of {sup 210}Pb in a variety of bone samples from 3 individuals have been measured in vitro using underground {gamma}-ray spectrometry. The individuals were unlikely to have had elevated intakes of Rn. These measurements give baseline data on the bone massic activity of {sup 210}Pb. They show that the massic activity is similar for each of these people and there are similar massic activities of {sup 210}Pb in the skull and the knee of the 2 individuals for which the skull was measured. Additionally for 2 of the individuals trabecular and cortical bone were separated and massic activities were found to be strongly correlated indicating that the {sup 210}Pb is associated with the hydroxyapatite.

  10. Plant exposure chambers for study of toxic chemical-plant interactions (journal version)

    International Nuclear Information System (INIS)

    McFarlane, J.C.; Pfleeger, T.

    1987-01-01

    Chambers for the study of plant uptake and phytotoxicity of toxic, radio-labeled chemicals are described. The chambers are designed to meet the criteria of continuously stirred tank reactors while providing containment for toxic chemicals. They are computer managed and operated within a controlled-environment room. Besides providing controlled conditions within the contained spaces, continuous measurements are made of various environmental parameters and plant transpiration, net photosynthesis, and dark respiration in up to 18 separate chambers

  11. γ-converting plate system for neutrino-deuterium exposures in the FNAL 15-foot bubble chamber

    International Nuclear Information System (INIS)

    Hanlon, J.; Mann, W.A.; Sommars, S.; Wald, H.

    1978-01-01

    During May 18-20 of this year the hydrogen-filled 15-foot bubble chamber at Fermilab was operated with an array of four half-inch thick stainless steel plates mounted in downstream portions of the fiducial volume. Notes from the test run, and results from a Monte Carlo study of efficiencies of the plate array for detection of photons and positrons in final states produced in a wide-band neutrino--deuterium exposure, are presented

  12. Attached, unattached fraction of progeny concentrations and equilibrium factor for dose assessments from {sup 222}Rn and {sup 220}Rn

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Parminder; Saini, Komal; Bajwa, Bikramjit Singh [Guru Nanak Dev University, Department of Physics, Amritsar, Punjab (India); Mishra, Rosaline; Sahoo, Bijay Kumar [Bhabha Atomic Research Centre, Radiological Physics and Advisory Division, Mumbai (India)

    2016-08-15

    In this study, measurements of indoor radon ({sup 222}Rn), thoron ({sup 220}Rn) and their equilibrium equivalent concentration (EEC) were carried out in 96 dwellings from 22 different villages situated in Hamirpur district, Himachal Pradesh, India, by using LR-115 type II-based pinhole twin cup dosimeters and deposition-based progeny sensors (DRPS/DTPS). The annual average indoor {sup 222}Rn and {sup 220}Rn concentrations observed in these dwellings were 63.82 and 89.59 Bq/m{sup 3}, respectively, while the average EEC (attached + unattached) for {sup 222}Rn and {sup 220}Rn was 29.28 and 2.74 Bq/m{sup 3}. For {sup 222}Rn (f{sub Rn}) and {sup 220}Rn (f{sub Tn}), the average values of unattached fraction were 0.11 and 0.09, respectively. The equilibrium factors for radon (F{sub Rn}) and thoron (F{sub Tn}) varied from 0.12 to 0.77 with an average of 0.50, and from 0.01 to 0.34 with an average of 0.05, respectively. The annual inhalation dose due to mouth and nasal breathing was calculated using dose conversion factors and unattached fractions. The indoor annual effective doses for {sup 222}Rn (AEDR) and {sup 220}Rn (AEDT) were found to be 1.92 and 0.83 mSv a{sup -1}, respectively. The values of {sup 222}Rn/{sup 220}Rn concentrations and annual effective doses obtained in the present study are within the safe limits as recommended by the International Commission on Radiological Protection for indoor dwelling exposure conditions. (orig.)

  13. Determination of Rn-222 in drinking water. An important parameter for the natural radioactivity exposure assessment; Bestimmung von {sup 222}Rn in Trinkwasser. Ein wichtiger Parameter fuer die Erfassung der natuerlich bedingten Strahlenbelastung

    Energy Technology Data Exchange (ETDEWEB)

    Zoiy, Myroslav [Forschungszentrum Juelich GmbH (Germany)

    2017-08-01

    The natural radiation exposure includes external exposure due to terrestric and cosmic radiation and internal exposure due to respiration and food - incorporation. Incorporated radionuclides are partially absorbed in the vascular and lymphatic systems and partially excreted after a certain biological half-time through kidneys and intestines, and partially the lungs. The radiation exposure is defined as effective annual dose in Sievert. In Germany the medium natural exposure is 2.1 mSv per year.

  14. Development of a dose-controlled multiculture cell exposure chamber for efficient delivery of airborne and engineered nanoparticles

    International Nuclear Information System (INIS)

    Asimakopoulou, Akrivi; Daskalos, Emmanouil; Papaioannou, Eleni; Konstandopoulos, Athanasios G; Lewinski, Nastassja; Riediker, Michael

    2013-01-01

    In order to study the various health influencing parameters related to engineered nanoparticles as well as to soot emitted by Diesel engines, there is an urgent need for appropriate sampling devices and methods for cell exposure studies that simulate the respiratory system and facilitate associated biological and toxicological tests. The objective of the present work was the further advancement of a Multiculture Exposure Chamber (MEC) into a dose-controlled system for efficient delivery of nanoparticles to cells. It was validated with various types of nanoparticles (Diesel engine soot aggregates, engineered nanoparticles for various applications) and with state-of-the-art nanoparticle measurement instrumentation to assess the local deposition of nanoparticles on the cell cultures. The dose of nanoparticles to which cell cultures are being exposed was evaluated in the normal operation of the in vitro cell culture exposure chamber based on measurements of the size specific nanoparticle collection efficiency of a cell free device. The average efficiency in delivering nanoparticles in the MEC was approximately 82%. The nanoparticle deposition was demonstrated by Transmission Electron Microscopy (TEM). Analysis and design of the MEC employs Computational Fluid Dynamics (CFD) and true to geometry representations of nanoparticles with the aim to assess the uniformity of nanoparticle deposition among the culture wells. Final testing of the dose-controlled cell exposure system was performed by exposing A549 lung cell cultures to fluorescently labeled nanoparticles. Delivery of aerosolized nanoparticles was demonstrated by visualization of the nanoparticle fluorescence in the cell cultures following exposure. Also monitored was the potential of the aerosolized nanoparticles to generate reactive oxygen species (ROS) (e.g. free radicals and peroxides generation), thus expressing the oxidative stress of the cells which can cause extensive cellular damage or damage on DNA.

  15. Development of a dose-controlled multiculture cell exposure chamber for efficient delivery of airborne and engineered nanoparticles

    Science.gov (United States)

    Asimakopoulou, Akrivi; Daskalos, Emmanouil; Lewinski, Nastassja; Riediker, Michael; Papaioannou, Eleni; Konstandopoulos, Athanasios G.

    2013-04-01

    In order to study the various health influencing parameters related to engineered nanoparticles as well as to soot emitted by Diesel engines, there is an urgent need for appropriate sampling devices and methods for cell exposure studies that simulate the respiratory system and facilitate associated biological and toxicological tests. The objective of the present work was the further advancement of a Multiculture Exposure Chamber (MEC) into a dose-controlled system for efficient delivery of nanoparticles to cells. It was validated with various types of nanoparticles (Diesel engine soot aggregates, engineered nanoparticles for various applications) and with state-of-the-art nanoparticle measurement instrumentation to assess the local deposition of nanoparticles on the cell cultures. The dose of nanoparticles to which cell cultures are being exposed was evaluated in the normal operation of the in vitro cell culture exposure chamber based on measurements of the size specific nanoparticle collection efficiency of a cell free device. The average efficiency in delivering nanoparticles in the MEC was approximately 82%. The nanoparticle deposition was demonstrated by Transmission Electron Microscopy (TEM). Analysis and design of the MEC employs Computational Fluid Dynamics (CFD) and true to geometry representations of nanoparticles with the aim to assess the uniformity of nanoparticle deposition among the culture wells. Final testing of the dose-controlled cell exposure system was performed by exposing A549 lung cell cultures to fluorescently labeled nanoparticles. Delivery of aerosolized nanoparticles was demonstrated by visualization of the nanoparticle fluorescence in the cell cultures following exposure. Also monitored was the potential of the aerosolized nanoparticles to generate reactive oxygen species (ROS) (e.g. free radicals and peroxides generation), thus expressing the oxidative stress of the cells which can cause extensive cellular damage or damage on DNA.

  16. Ionization chambers

    International Nuclear Information System (INIS)

    Boag, J.W.

    1987-01-01

    Although a variety of solid-state and chemical methods for measuring radiation dose have been developed in recent decades and calorimetry can now provide an absolute standard of reference, ionization dosimetry retains its position as the most widely used, most convenient, and, in most situations, most accurate method of measuring either exposure or absorbed dose. The ionization chamber itself is the central element in this system of dosimetry. In this chapter the principles governing the construction and operation of ionization chambers of various types are examined. Since the ionization chambers now in general use are nearly all of commercial manufacture, the emphasis is on operating characteristics and interpretation of measurements rather than on details of construction, although some knowledge of the latter is often required when applying necessary corrections to the measured quantities. Examples are given of the construction of typical chambers designed for particular purposes, and the methods of calibrating them are discussed

  17. Considerations for the design and technical setup of a human whole-body exposure chamber.

    Science.gov (United States)

    Monsé, Christian; Sucker, Kirsten; van Thriel, Christoph; Broding, Horst Christoph; Jettkant, Birger; Berresheim, Hans; Wiethege, Thorsten; Käfferlein, Heiko; Merget, Rolf; Bünger, Jürgen; Brüning, Thomas

    2012-01-01

    Exposures to air contaminants, such as chemical vapors and particulate matter, pose important health hazards at workplaces. Short-term experimental exposures to chemical vapors and particles in humans are a promising attempt to investigate acute effects of such hazards. However, a significant challenge in this field is the determination of effects of co-exposures to more than one chemical or mixtures of chemical vapors and/or particles. To overcome such a challenge, studies have to be conducted under standardized exposure characterization and real time measurements, if possible. A new exposure laboratory (ExpoLab) was installed at IPA, combining sophisticated engineering designs with new analytical techniques, to fulfill these requirements. Low-dose as well as high-dose exposure scenarios are achieved by means of a calibration-gas-generator. Exposure monitoring can be carried out with a high performance real time mass spectrometer and other suitable analyzers (e.g. gas chromatograph). Numerous automated security facilities guarantee the physical integrity of the volunteers, and the waste atmosphere is removed using either charcoal filtration or catalytic post-combustion. Measurements of sulfur hexafluoride, carbon dioxide, aniline and carbon black are presented to demonstrate the performance of the exposure unit with respect to the temporal and spatial stability of generated atmospheres. The variations of generated contents in the atmospheres at steady state are slightly higher than the measurement precision of the analyzers (the typical standard deviation of generated atmospheres is standards in validity and reliability of generating and measuring exposure atmospheres.

  18. Measurements of Rn-222, Rn-220 and their decay products in the environmental air of the high background radiation areas in Yangjiang, China

    International Nuclear Information System (INIS)

    Yuan Yongling; Shen Tong; Morishima, Hiroshige; Koga, Taeko; Wei Luxin; Sugahara, Tsutomu

    2000-01-01

    For the renewal of dose estimation from internal irradiation in the high background radiation areas (HBRA) of Yangjiang, the measurements of radon, thoron and their decay products in the environmental air were conducted, including: integrating measurements of Rn-222 and Rn-220 concentrations; equilibrium factor F for Rn-222 and alpha-potential energy value of Rn-220; external gamma radiation in places where radon measurements were undertaken; cumulative exposure to indoor radon for each family in a case-control study on lung cancer. The Rn-Tn cup monitor method was used for the integrating measurement of Rn-222 and Rn-220 concentration. An alpha track detector was used for the integration measurement of Rn-222 concentration in the case-control study on lung cancer. The results of measurements show that although the investigated areas are located between the Equator and the Tropic of Cancer, and that people live in well-ventilated dwellings, the concentrations of radon, especially of Rn-220 are significantly higher in the indoor air of HBRA than those in the control area. The value of equilibrium factors for Rn-222, the alpha potential energy of decay products from Rn-222 and Rn-220 are determined. (author)

  19. E-perm radon monitors for determining waterborne concentrations of dissolved in radon 222Rn

    International Nuclear Information System (INIS)

    Jester, W.A.; Kotrappa, P.

    1989-01-01

    This paper describes a simple and relatively inexpensive method in which E-Perm radon monitors are used to determine the concentration of dissolved 222 Rn in drinking water. This procedure takes advantage of E-Perm's ability to accurately measure the integral radon exposure under conditions of high humidity. The method was evaluated against the liquid scintillation procedure recommended by the U.S. Environmental Protection Agency (EPA) and was found to give excellent agreement. An E-perm is an electret ion chamber that consists of a small chamber constructed from a conducting plastic and having an electret at its base and a filtered air inlet at the top. The technique described in this paper takes advantages of E-Perm's insensitivity to high humidity

  20. Construction, calibration and test of an ionization chamber for exposure measurement of x and gamma radiation in region from 40 keV to 1250 keV

    International Nuclear Information System (INIS)

    Campos, C.A.A.L.

    1982-01-01

    An unsealed thimble ionization chamber with connecting cable was designed, manufactured and tested at the IRD=CNEN, for exposure or exposure rate measurement of X or gamma rays in the energy range from 40 KeV up to Cobalt-60. Recommendations given by IEC, TC-62 (1974) were used as acceptance tests of the ionization chamber for use as a tertiary standard (field class instruments) in radiation therapy. In addition, intercomparison with commercially available chambers of reference class type were carried out in respect to field size dependence, energy dependence, short and long term stability. The results of those tests indicated the usefulness of the developed ionization chamber as a tertiary standard. (author)

  1. Peak nasal inspiratory flow as outcome for provocation studies in allergen exposure chambers

    DEFF Research Database (Denmark)

    Boelke, Georg; Berger, Uwe; Bergmann, Karl-Christian

    2017-01-01

    : In a randomized controlled blinded setting subjects suffering from allergic rhinitis were exposed to grass pollen, birch pollen, house dust mite and/or placebo in the GA(2)LEN chamber. Different allergen concentrations were used to evaluate symptom severities. Patients had to perform PNIF before and every 30 min...... during a challenge using a portable PNIF meter. RESULTS: 86 subjects participated in 203 challenges, altogether. House dust mite provocations caused the greatest reduction in PNIF values, followed by grass pollen and birch pollen. Provocations with every allergen or pollen concentration led...... symptoms. CONCLUSION: PNIF is a helpful and feasible tool for conducting provocation trials with allergens, especially grass pollen and house dust mite, in an AEC....

  2. Inferring 222Rn soil fluxes from ambient 222Rn activity and eddy covariance measurements of CO2

    Directory of Open Access Journals (Sweden)

    S. van der Laan

    2016-11-01

    Full Text Available We present a new methodology, which we call Single Pair of Observations Technique with Eddy Covariance (SPOT-EC, to estimate regional-scale surface fluxes of 222Rn from tower-based observations of 222Rn activity concentration, CO2 mole fractions and direct CO2 flux measurements from eddy covariance. For specific events, the regional (222Rn surface flux is calculated from short-term changes in ambient (222Rn activity concentration scaled by the ratio of the mean CO2 surface flux for the specific event to the change in its observed mole fraction. The resulting 222Rn surface emissions are integrated in time (between the moment of observation and the last prior background levels and space (i.e. over the footprint of the observations. The measurement uncertainty obtained is about ±15 % for diurnal events and about ±10 % for longer-term (e.g. seasonal or annual means. The method does not provide continuous observations, but reliable daily averages can be obtained. We applied our method to in situ observations from two sites in the Netherlands: Cabauw station (CBW and Lutjewad station (LUT. For LUT, which is an intensive agricultural site, we estimated a mean 222Rn surface flux of (0.29 ± 0.02 atoms cm−2 s−1 with values  > 0.5 atoms cm−2 s−1 to the south and south-east. For CBW we estimated a mean 222Rn surface flux of (0.63 ± 0.04 atoms cm−2 s−1. The highest values were observed to the south-west, where the soil type is mainly river clay. For both stations good agreement was found between our results and those from measurements with soil chambers and two recently published 222Rn soil flux maps for Europe. At both sites, large spatial and temporal variability of 222Rn surface fluxes were observed which would be impractical to measure with a soil chamber. SPOT-EC, therefore, offers an important new tool for estimating regional-scale 222Rn surface fluxes. Practical applications furthermore include

  3. Environmental thoron (220Rn): a review

    International Nuclear Information System (INIS)

    Ramachandran, T.V.

    2008-01-01

    Studies on natural background radiation is a topic, which evoked curiosity and concern between the scientist and layman alike in recent years due to the shift in focus of health effects due to exposure of radiation from acute high level to chronic low level. Ever since studies on uranium miners established the presence of a positive risk coefficient for the occurrence of lung cancer in miners exposed to elevated levels of 222 Rn and its progeny, there was a great upsurge of interest in the measurement of 222 Rn in the environment. Subsequently, considerable data is being generated on the levels of 222 Rn in the environment across the worlds and is being periodically reported by UNSCEAR reports. In contrast to this, data pertaining to 220 Rn in indoors and workplace environment is scare due to the general perception that its levels are negligible due to its shorter half life, and subsequently its contribution to the total inhalation dose is ignored, in the presence of other significant sources of natural radiation. This may not be true from the recent studies resulted in observing high 220 Rn levels in living environments and work places in various countries and it is increasingly felt that it may be necessary to have data on 220 Rn levels in environment for obtaining a complete picture of inhalation dose. Globally many locations have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products, like radon ( 222 Rn), and thoron ( 220 Rn) in the environment. Of late, technologically enhanced naturally occurring radioactive material has also contributed to the burden of background radiation. It is estimated inhalation of 222 Rn, 220 Rn and their short lived progenies contribute more than 54 % of the total natural background radiation dose received by the general population. Due to this it was necessary to supplement the external component with inhalation component. This component is not

  4. Measurements of indoor 222RN activity in dwellings and workplaces of Curitiba (Brazil)

    International Nuclear Information System (INIS)

    Corrêa, Janine N.; Paschuk, Sergei A.; Del Claro, Flávia; Kappke, Jaqueline; Perna, Allan F.N.; Schelin, Hugo R.; Denyak, Valeriy

    2014-01-01

    The present work describes the results of systematic measurements of radon ( 222 Rn) in residential environments and workplaces in the Metropolitan Region of Curitiba (Paraná State, Brazil) during the period 2004–2012. For radon in air activity measurements, polycarbonate Track Etch Detectors CR-39, mounted in diffusion chambers protected by borosilicate glass fiber filters, were used. After being exposed in air, the CR-39 detectors were submitted to a chemical etching in a 6.25 M NaOH solution at 70 °C for 14 h. The alpha particle tracks were identified and manually counted with an optical microscope, and with the results of previously performed calibrations, the indoor activity concentration of 222 Rn was calculated. The calibration of CR-39 and the alpha particle tracks chemical development procedures were performed in collaboration the National Institute of Radiological Sciences (NIRS, Japan). The major part of indoor 222 Rn concentration in residences was found to be below 100 Bq/m 3 . In the case of working places, all measurements of 222 Rn concentrations were below 100 Bq/m 3 . These values are considered within the limits set by international regulatory agencies, such as the US EPA and ICRP, which adopt up to 148 and 300 Bq/m 3 as upper values for the reference levels for radon gas activity in dwellings, respectively. The latest value of 300 Bq/m 3 for radon activity in air is proposed by ICRP considering the upper value for the individual dose reference level for radon exposure of 10 mSv/yr. - Highlights: • Radon activity in air of dwellings was measured. • Radon activity in air of workplaces was measured. • Obtained experimental results are compared with International Norms and Regulations

  5. Doses to LiF :Ti, Mg chips encapsulated in plastic extremity rings as a result of radon gas exposure

    International Nuclear Information System (INIS)

    Kearfott, Kimberlee J; Noon, Evan P; Rafique, Muhammad

    2015-01-01

    Previous studies measured the effects of 222 Rn on various thermoluminescent dosemeters (TLDs). This study quantified the effects of 222 Rn on LiF : Ti,Mg chips encapsulated in plastic extremity rings. For 28 d, one batch of TLDs was left in a chamber with high radon levels, and another batch in a control chamber with normal background radon levels. A few TLDs in each batch were removed from the rings for direct exposure to the ambient air in each chamber. Passive continuous radon monitors (CRMs) recorded the 222 Rn levels. TLDs were processed using a third-party dosimetry company, CRM data were analysed, and the relationship between integrated 222 Rn concentration and TLD response was determined. The batch of TLDs in the experimental chamber showed a weak response to 222 Rn gas, which was in the order of 0.5 nSv Bq −1  m 3  d −1 . (paper)

  6. A preliminary investigation of 222Rn and 220Rn levels in non-uranium mines in China

    International Nuclear Information System (INIS)

    Shang Bing; Cui Hongxing; Wu Yunyun; Zhang Qingzhao; Su Xu

    2008-01-01

    Objective: To measure levels of 222 Rn and 220 Rn in typical non-uranium mines, China, and to estimate dose from the occupational radon exposure in the miners. Methods: Using typical sampling scheme, 44 mines were selected in 12 provinces, which can be classified into 4 categories and 17 types of mines. The radon-thoron discriminative detectors were used to measure 222 Rn and 220 Rn concentrations in mines. Result: The concentration of 222 Rn or 220 Rn was log-normally distributed. The arithmetic mean (AM) concentration and geometric mean (GM) concentration of 222 Rn and 220 Rn in 25 metal mines (n=147) were estimated to be (1211 ±2359) Bq/m 3 (AM) and (311 ± 5.5) Bq/m 3 (GM), and (269 ±700) Bq/m 3 (AM) and (71 ± 4.4)Bq/m 3 (GM), respectively. The mean concentrations of 222 Rn and 220 Rn in 18 non-metal mines (n=118) were (98 ± 207) Bq/m 3 (AM) and(55 ± 2.5) Bq/m 3 (GM), and (60 ± 76) Bq/m 3 (AM) and (38 ± 2.4) Bq/m 3 (GM) respectively. In total, we measured 222 Rn concentration in 44 underground mines, 6 of them, accounted for 15%, with the mean radon concentration exceeding 1000 Bqm -3 (limit of workplace in China). Approximately 7% of radon concentration in mines measured were higher than 3700 Bq/m 3 (current limit in uranium mine in China), some points even exceeded 10 000 Bq/m 3 . Based on this typical measurements, the equilibrium factor for 222 Rn was estimated to be 0.33 ± 0.15 in underground mines and 0.47 ±0.18 in nearby houses. Equilibrium factor for 220 Rn ranged from 0.001 to 0.032. Using the data obtained in this typical survey, the average annual effective dose of underground miners exposed to radon and thoron was estimated to be 8.15 mSv/a. Conclusions: High levels of 222 Rn exists in metal mines, such as copper, tin, lead and zinc, gold, and aluminum mines among others. More study and administrative measures are needed to address the radiation protection of workers occupationally exposed to high radon in mines. (authors)

  7. Multiplication on Rn -A ...

    Indian Academy of Sciences (India)

    topology can be used to prove the results in the first article. While the discussion ... {O}) x (JRn \\ {O}) ~ JRn \\ {O} with an element e E ]Rn \\ {O} such that m(e, ... in 1966, using sophisticated methods from topology. To state this ... If G is a finite group then G is a ... (Topology on Sn is of course the induced topology from. JRn+1.) ...

  8. Comparison of methods and instruments for 222Rn/220Rn progeny measurement

    International Nuclear Information System (INIS)

    Liu Yanyang; Shang Bing; Wu Yunyun; Zhou Qingzhi

    2012-01-01

    In this paper, comparisons were made among three methods of measurement (grab measurement, continuous measurement and integrating measurement) and also measurement of different instruments for a radon/thoron mixed chamber. Taking the optimized five-segment method as a comparison criterion, for the equilibrium-equivalent concentration of 222 Rn, measured results of Balm and 24 h integrating detectors are 31% and 29% higher than the criterion, the results of Wl x, however, is 20% lower; and for 220 Rn progeny, the results of Fiji-142, Kf-602D, BWLM and 24 h integrating detector are 86%, 18%, 28% and 36% higher than the criterion respectively, except that of WLx, which is 5% lower. For the differences shown, further research is needed. (authors)

  9. A micromegas detector for {sup 222}Rn emanations measurements

    Energy Technology Data Exchange (ETDEWEB)

    García, J. A.; Garza, J. G.; Irastorza, I. G.; Mirallas, H. [Laboratorio de Física Nuclear y Altas Energías, Universidad de Zaragoza, Zaragoza (Spain)

    2013-08-08

    The {sup 222}Rn emanation has significant contribution in the overall background for rare event searches experiments. In order to measure this emanations a high sensitivity detector has been designed. The detection method is based on the electrostatic collection of the {sup 222}Rn daughters on a Micromegas detector. Using a chamber with a volume of 21.2 l for the collection of {sup 218}Po and {sup 214}Po progeny of {sup 222}Rn and a 12 × 12cm{sup 2} pixelized Micromegas for the α detection. The advantages of the Micromegas detectors are the low intrinsic radioactivity and the track reconstruction of the α’s, having excellent capabilities for event discrimination.

  10. Spectroscopy of 212Rn

    International Nuclear Information System (INIS)

    Stuchbery, A.E.; Dracoulis, G.D.; Byrne, A.P.; Poletti, A.R.

    1988-01-01

    Excited states of 212 Rn have been studied using γ-ray and electron spectroscopy following the reactions 208 Pb( 9 Be, 5n) and 204 Hg( 13 C,5n). With the exception of the energy of the yrast 8 + → 6 + transition, the previously proposed level scheme has been verified. New transitions have been placed in the level scheme and new lifetime and g-factor results obtained. The level scheme and electromagnetic properties of selected isomeric states are compared with the results of shell model and semi-empirical shell-model calculations, including coupling to octupole vibrations. (orig.)

  11. Spectroscopy of 212Rn

    International Nuclear Information System (INIS)

    Stuchbery, A.E.; Dracoulis, G.D.; Byrne, A.P.; Poletti, A.R.

    1988-06-01

    Excited states of 212 Rn have been studied using γ-ray and electron spectroscopy following the reactions 208 Pb ( 9 Be,5n) and 204 Hg( 13 C,5n). With the exception of the energy of the yrast 8 + → 6 + transition, the previously proposed level scheme has been verified. New transitions have been placed in the level scheme and new lifetime and g-factor results obtained. The level scheme and electromagnetic properties of selected isomeric states are compared with the results of shell model and semi-empirical shell-model calculations, including coupling to octupole vibrations

  12. 222Rn studies and mapping in the city of Curitiba - Brazil

    International Nuclear Information System (INIS)

    Correa, Janine Nicolosi; Fior, Loriane; Paschuk, Sergei A.; Schelin, Hugo R.; Pecequilo, Brigitte R. S.; Paula Melo, Vicente de

    2008-01-01

    This work describes radon monitoring performed in cooperation between the Laboratory of Ionizing Radiations of the Federal University of Technology - Parana (UTFPR), the Institute of Nuclear and Energetic Researches (IPEN) and the Institute of Radiation Protection and Dosimetry (IRD), from the Brazilian Nuclear Energy Commission (CNEN), during the last two years. For 222 Rn concentration measurements related to different construction materials as well as for the studies of radon emanation and its reduction, the sealed cell chambers, of approximately 60 x 60 cm 2 , was built using ceramic and concrete blocks. This construction was performed within a protected and isolated laboratory environment to maintain the air humidity and temperature stable. These long term measurements have been performed using polycarbonate alpha track passive detectors. The exposure time was set to 15 days considering previous calibration performed at IRD, where a efficiency of 70% was obtained for the density of alpha particle tracks about 13.8 cm -2 per exposure day and per kBq/m 3 of radon activity concentration. The chemical development of the alpha tracks was achieved by electrochemical etching. The track identification and counting were done using a code based on the MATLAB Image Processing Toolbox. The cell chambers were built following four main steps: 1) assembling the walls using the blocks and mortar; 2) plaster installation; 3) wall surface finishing using lime; 4) wall surface insulation by paint. By comparison between three layers installed at the masonry walls from concrete and ceramic blocks, it was concluded that only wall painting with acrylic varnish attended the expectation and reduced the radon emanation flow by a factor of approximately 2.5. The construction materials were submitted to the instant measurements of radon concentration using a ALPHA GUARD Professional detector. The samples of the construction materials were stored inside an acrylic container (sealed up

  13. Stressede børn

    DEFF Research Database (Denmark)

    Tonseberg, Signe

    2016-01-01

    Stressede børn får det bedre, når deres krop får lov at tale. Fysioterapeut Pernille Thomsen lærer børn at bruge kroppen, så de trives bedre. Og der er ingen hokuspokus, for det hele bygger på naturvidenskabelig forskning i kroppens hormoner og stress....

  14. Estimating Rn-induced lung cancer in the United States

    International Nuclear Information System (INIS)

    Lubin, J.H.; Boice, J.D. Jr.

    1989-01-01

    The proportion of lung cancer deaths attributable to Rn among residents of single-family homes in the U.S. (approximately 70% of the housing stock) is estimated using the log-normal distribution of Rn concentrations proposed by Nero et al. (1986) and the risk model developed by the National Academy of Sciences' BEIR IV Committee. The risk model, together with the exposure distribution, predicts that approximately 14% of lung cancer deaths among such residents (about 13,300 deaths per year, or 10% of all U.S. lung cancer deaths) may be due to indoor Rn exposure. The 95% confidence interval is 7%-25%, or approximately 6600 to 24,000 lung cancer deaths. These estimated attributable risks due to Rn are similar for males and females and for smokers and nonsmokers, but higher baseline risks of lung cancer result in much larger absolute numbers of Rn-attributable cancers among males (approximately 9000) and among smokers (approximately 11,000). Because of the apparent skewness of the exposure distribution, most of the contribution to the attributable risks arises from exposure rates below 148 Bq m-3 (4 pCi L-1), i.e., below the EPA action level. As a result, if all exposure rates that exceed 148 Bq m-3 (approximately 8% of homes) were eliminated, the models predict that the total annual lung cancer burden in the U.S. would drop by 4-5%, or by about 3800 lung cancer deaths, in contrast to a maximum reduction of 14% if all indoor Rn exposure above the 1st percentile were eliminated

  15. Correlation among the terrestrial gamma radiation, the indoor air 222Rn, and the tap water 222Rn in Switzerland

    International Nuclear Information System (INIS)

    Buchli, R.; Burkart, W.

    1989-01-01

    The external gamma radiation and the indoor air Rn (222Rn) concentration were measured in 55 houses of the South East Grisons, the Urseren valley, and the Upper Rhine valley (crystalline subsoils) and in 39 houses of the Molasse basin and the Helvetic nappes (sedimentary subsoils). In homes located on a crystalline subsoil, a mean cellar gamma level of 1.40 mGy y-1 was measured, which is twice the mean gamma level of 0.70 mGy y-1 found in homes built on a sedimentary subsoil. The cellar 222Rn gas concentration is about six times higher in houses with a crystalline subsoil (1232 Bq m-3) than in houses with a sedimentary subsoil (201 Bq m-3). Although a weak correlation is observed between the mean gamma radiation levels and mean cellar 222Rn gas concentrations for the five subregions investigated, the gamma levels and the 222Rn gas concentrations do not correlate for single homes. For the population living on the ground floor of a house with a crystalline subsoil, the gamma radiation and the indoor air 222Rn lead to estimated mean exposures of 1.16 mSv and 9.44 mSv effective dose equivalent per year, respectively. In houses with a sedimentary subsoil, these mean exposures lead to 0.68 mSv y-1 and 3.22 mSv y-1, respectively. A mean tap water 222Rn content of 38.3 Bq L-1 and 10.4 Bq L-1 was measured in 31 villages with a crystalline subsoil and 73 villages with a sedimentary subsoil, respectively. Radon-222 degasing from the tap water into the indoor air leads to an additional exposure of about 0.11 mSv y-1 and 0.03 mSv y-1 in homes with a crystalline subsoil and homes with a sedimentary subsoil, respectively

  16. 222Rn alpha dose to organs other than lung

    International Nuclear Information System (INIS)

    Harley, N.H.; Robbins, E.S.

    1991-01-01

    The alpha dose to cells in tissues or organs other theft the lung has been calculated using the solubility coefficients for 222 Rn measured in human tissue. The annual alpha dose equivalent f rom 222 Rn and decay products in most tissues is a maximum of 30% of the annual average natural background dose equivalent (1 mSv) for external and internally deposited nuclides. The dose to the small population of lymphocytes located in or under the bronchial epithelium is a special case and their annual dose equivalent is essentially the same as that to basal cells in bronchial epithelium (200 mSv) for continuous exposure to 200 Bq M -3 . The significance of this dose is uncertain because the only excess cancer observed in follow up studies of underground miners with high 222 Rn exposure is bronchogenic carcinoma

  17. Assessing RN-to-RN peer review on clinical units.

    Science.gov (United States)

    Pfeiffer, Judith A; Wickline, Mary A; Deetz, Jill; Berry, Elise S

    2012-04-01

    The primary purpose of this study was to measure informal registered nurse (RN)-to-RN peer review (defined as collegial communication about the quality of nursing care) at the work-unit level. Survey design with cluster sampling of 28 hospital or ambulatory care units (n = 541 respondents). Results were compared with existing patient safety and satisfaction data. A chi-squared test was used to compare responses against nurse characteristics. Nurses agreed that RN-to-RN peer review takes place on their units, but no correlation with patient safety and satisfaction data was found. Misunderstandings about the meaning of peer review were evident. Open-ended comments revealed barriers to peer review: fear of retribution, language barriers and lack of professionalism. Nurses need clarification of peer review. Issues with common language in a professional environment need to be addressed and nurses can learn collaboration from each other's cultures. Managers should support RN-to-RN peer review on clinical units. Methods used here may be useful to assess current departmental nurse peer review. © 2011 Blackwell Publishing Ltd.

  18. Occupational exposure assessment and radiation dose estimation of vegetable-plant farmers to 222Rn in greenhouses of Shouguang county, China

    International Nuclear Information System (INIS)

    Wanwei Li; Weifang Medical University, Weifang, Shandong; Xiaohong Li; Fei Wang; Yongyong Xu

    2016-01-01

    This study aims to: assess exposure levels of radon and explore seasonal variations of radon concentrations in greenhouses in Shouguang county. Estimate annual radon radiation dose level for vegetable-plant farmers working in greenhouses. During detection period, the annual mean radon concentration was approximately 286 Bq m -3 . The annual radon radiation dose of farmers is 3.3 mSv a -1 . Both obvious seasonal variations in average radon concentrations and radon radiation dose in greenhouses are observed. Both levels are much higher in winter and spring than in summer and autumn. (author)

  19. Retrospective look at Rn-induced lung cancer mortality from the viewpoint of a relative risk model

    International Nuclear Information System (INIS)

    Puskin, J.S.; Yang, Y.

    1988-01-01

    The potential contribution to U.S. lung cancer deaths from 1930 to 1987 from indoor 222 Rn exposures is investigated from the standpoint of a constant relative risk model. Based on this model, which assumes a Rn risk proportional to the baseline lung cancer risk from other causes, the rate of Rn-induced lung cancer mortality has been increasing sharply since 1930. However, the estimated proportion of lung cancer deaths attributable to Rn has remained fairly constant. Applying the range of coefficients the U.S. Environmental Protection Agency employs in assessing the risk from indoor Rn, it is estimated that 8-25% of all current lung cancer deaths are attributable to past Rn exposures. The major sources of uncertainty in the estimates are discussed

  20. rn Utzon

    Directory of Open Access Journals (Sweden)

    Jaime J. Ferrer Forés

    2017-07-01

    Full Text Available Este artículo analiza el proyecto del arquitecto danés Jørn Utzon (1918-2008 para la construcción de la Escuela de la Unión de trabajadores daneses en Højstrup, Helsingør (1958-1962, desde las dos propuestas presentadas al concurso, que obtienen el primer y segundo premio, a las versiones del proyecto que desarrolla simultáneamente al proyecto de la Ópera de Sídney (1956-1973. El análisis de la evolucióndel proyecto de Højstrup permite aproximarse al talento plástico y al universo de extraordinario lirismo del arquitecto, a través de la exploración formal que desarrolla en torno a las plataformas y los recintos, a la relación entre los dos elementos de la escala tipológica, la torre y el cuerpo bajo, al estudio de los mecanismos de acceso mediante la porte-cochère, al sistema de agregación de las casas patio o el papel que desempeña la estructura en el proyecto, en un ejercicio de exploración arquitectónica que fluye desde los concursos, entendidos como laboratorios de experiencias formales, al desarrollo lento y gradual de los proyectos sucesivos atendiendo a la vez el sitio y la pieza tipológica, en una cuidada innovación plástica que reivindica la experimentación constructiva y la integración en el paisaje.

  1. Ionization chamber

    International Nuclear Information System (INIS)

    Jilbert, P.H.

    1975-01-01

    The invention concerns ionization chambers with particular reference to air-equivalent ionization chambers. In order to ensure that similar chambers have similar sensitivities and responses the surface of the chamber bounding the active volume carries a conducting material, which may be a colloidal graphite, arranged in the form of lines so that the area of the conducting material occupies only a small proportion of the area of said surface. (U.S.)

  2. Test chamber

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes

    2009-01-01

    A test chamber for measuring electromagnetic radiation emitted by an apparatus to be tested or for exposing an apparatus to be tested to an electromagnetic radiation field. The test chamber includes a reverberation chamber made of a conductive tent fabric. To create a statistically uniform field in

  3. The German thoron progeny chamber-Concept and application

    International Nuclear Information System (INIS)

    Roettger, Annette; Honig, Anja; Arnold, Dirk

    2009-01-01

    Following completion of the project 'Generation and characterisation of reference atmospheres of thoron decay products for the calibration of measuring devices for thoron decay products', the Physikalisch-Technische Bundesanstalt (PTB) now operates a thoron progeny chamber in which 220 Rn (thoron), 222 Rn and its progenies can be made available under almost all ambient conditions. This allows all measuring systems to be calibrated under realistic climatic conditions with an accuracy unique worldwide.

  4. Measurements of 222Rn flux with charcoal coanisters

    International Nuclear Information System (INIS)

    Countess, R.J.

    1977-01-01

    Methods used to measure the 222 Rn flux from the ground are discussed. The most common method is the direct accumulation of radon in a closed container resting on the soil surface. An aliquot of the air is transferred from the accumulator either to an ionization chamber or to an alpha scintillation flask for radon analysis. An alternate method consists of entraining the radon emanating from a small area of the ground in an airstream moving in a closed system through a charcoal trap or cold trap. At the end of the sampling period, the trap is sealed and returned to the laboratory where the radon is transferred into an evacuated scintillation flask for analysis. Still another method consists of adsorbing radon in a layer of granular, activated charcoal spread directly on the ground. For analysis, the charcoal is bagged and the 0.61-MeV gamma activity of 214 Bi (RaC) is measured in a gamma spectrometer. These last two methods have the disadvantage that some radon may be lost in transfer prior to analysis. In an improved method, which is simpler than the preceding methods and eliminates this transfer problem, a modified U.S. Army M11 gas mask canister containing activated charcoal is placed directly in contact with the emanating surface and after an exposure period from several hours to several days, depending on the anticipated flux density, the canister is removed from the surface and counted directly in a gamma spectrometer. In addition to precluding losses in sample transfer, a major advantage is that numerous measurements can be made inexpensively due to the low cost of the canisters and their ease of deployment and recovery

  5. Matérn thinned Cox processes

    DEFF Research Database (Denmark)

    Andersen, Ina Trolle; Hahn, Ute

    2016-01-01

    and hard core behaviour can be achieved by applying a dependent Matérn thinning to a Cox process. An exact formula for the intensity of a Matérn thinned shot noise Cox process is derived from the Palm distribution. For the more general class of Matérn thinned Cox processes, formulae for the intensity...

  6. Matérn thinned Cox processes

    DEFF Research Database (Denmark)

    Andersen, Ina Trolle; Hahn, Ute

    of clustering and hard core behaviour can be achieved by applying a dependent Matérn thinning to a Cox process. An exact formula for the intensity of a Matérn thinned shot noise Cox process is derived from the Palm distribution. For the more general class of Matérn thinned Cox processes, formulae...

  7. Construction, calibration and testing of a ionization chamber for exposure measurement of X and gamma rays in the energy range from 40 keV up to 1250KEV

    International Nuclear Information System (INIS)

    Campos, Carlos A.A. Lima

    1982-01-01

    An unsealed thimble ionization chamber with connecting cable was designed, manufactured and tested at the IRD/CNEN, for exposure or exposure rate measurement of X or gamma rays in the energy range from 40 keV up to Cobalt-60. Recommendations given by IEC,TC-62(1974) were used as acceptance tests of the ionization chamber for use as a tertiary standard (field class instruments) in radiation therapy. In addition, intercomparison with commercially available chambers of reference class type were carried out in respect to field size dependence, energy dependence, short and long term stability.The results of those tests indicated the usefulness of the developed ionization chamber as a tertiary standard. (author)

  8. Selection of design parameters of diffusion barrier in a passive 222Rn sampler based on activated charcoal adsorption

    International Nuclear Information System (INIS)

    Wei Suxia

    1992-01-01

    A method concerning selection of design parameters of diffusion barrier in a passive 222 Rn sampler based on activated charcoal adsorption. The proper parameter value of diffusion barrier is obtained by means of linearization of 222 Rn adsorption versus the exposure time. Thus, the influence of temperature on measured results may be greatly decreased, and higher sensitivity of the detector may be maintained

  9. Thoron (220Rn) in the indoor atmospheric environment

    International Nuclear Information System (INIS)

    Ramachandran, T.V.

    2006-01-01

    Naturally occurring background radiation is a topic, which has evoked curiosity and concern between the scientist and layman alike in recent years due to the shift in focus of health effects due to exposure of radiation from acute high level to chronic low level. Many locations around the world have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products like radon ( 222 Rn), and thoron ( 220 Rn) in the environment. Of late, technologically enhanced naturally occurring radioactive material has also contributed to the burden of background radiation. It has been estimated that inhalation of 222 Rn, 2 20 Rn and their short lived progenies contribute more than 54% of the total natural background radiation dose received by the general population. In the Indian context, in an earlier national survey, the external gamma radiation dose rates have been more or less well mapped using thermo luminescent dosimeters covering more than 214 locations, which has yielded a national average of 775 mGy/y. Of this, nearly 48.7% contribution of the dose rate is from 40 K and the rest from the uranium (33.6%) and thorium (17.7%) series. A good database pertaining to the country wide levels of uranium, thorium and potassium in geological materials also exists. Thus, there exists a good database on the total external gamma radiation level across the country. Since the contribution from inhalation of 222 Rn, 220 Rn and their short lived progenies contributes more than 54% of the total background radiation dose, it was necessary to supplement the external component with inhalation component. This component is not adequately estimated for the country so far on national level. With this in mind, a national survey has been executed by this center involving a large number of universities and other allied research institutions from different parts of the country for the estimation of inhalation component of the dose

  10. In vitro exposure of human lung cells to emissions of several indoor air sources created in a climate chamber

    NARCIS (Netherlands)

    Bluyssen, P.M.; Alblas, M.J.; Tuinman, I.L.

    2013-01-01

    In the last decade, studies on indoor air pollution suggest a link between exposure to indoor particulate matter and compounds, in particular ultrafine particles and secondary organic aerosols, and several health effects. The mechanisms of how those complex mixtures relate to health effects are

  11. Ussing Chamber

    NARCIS (Netherlands)

    Westerhout, J.; Wortelboer, H.; Verhoeckx, K.

    2015-01-01

    The Ussing chamber system is named after the Danish zoologist Hans Ussing, who invented the device in the 1950s to measure the short-circuit current as an indicator of net ion transport taking place across frog skin (Ussing and Zerahn, Acta Physiol Scand 23:110-127, 1951). Ussing chambers are

  12. Radium-226 body burden in U miners by measurement of Rn in exhaled breath.

    Science.gov (United States)

    Srivastava, G K; Raghavayya, M; Kotrappa, P; Somasundaram, S

    1986-02-01

    Uranium miners were made to inhale Rn-free medical O2 and exhale through a 5.2-1 A1 chamber before reporting to work. The chamber was sealed and isolated from the sampling circuit. An electrostatic plate collected the freshly formed Rn-decay products. The subsequent programmed alpha counting of the plate yielded a Rn concentration in the exhaled breath. Assuming that the exhaled breath represents a certain fraction of the Rn produced inside the body, the body burden of 226Ra was calculated. Standardisation of this procedure and the data collected on 310 miners are discussed. The procedure is simple and applicable for routine measurements. The miner needs to be in the laboratory for only 10 min. The system is also portable for field application. For routine use, the minimum detectable concentration is 3.87 Bq X m-3 which corresponds to a body burden of 0.26 kBq in a typical miner, if one assumes the Rn release fraction from the body as 84%. The system offers a more convenient and sensitive alternative to whole-body counting of workers for 226Ra.

  13. wire chamber

    CERN Multimedia

    Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

  14. A Radon Chamber without Radium Source for Detector Calibration and Radon Measurements

    International Nuclear Information System (INIS)

    Al-Azmi, D.; Karunakara, N.

    2008-01-01

    A radon chamber of volume 216 liters was designed and constructed for calibration of radon detectors and radon test measurements. The main feature of this chamber is that the active 226 Ra source, to generate the 222 Rn inside the chamber volume, is not required. Instead, 222 Rn from soil gas is utilized for this purpose. The supply of radon comes from the soil gas. Soil gas is drawn from the soil to fill the chamber with high radon concentration levels (∼ 80 kBq/m3). Desired radon concentration levels can be obtained by drawing the soil gas for different time durations and/or flow rate (author)

  15. Drift chamber

    International Nuclear Information System (INIS)

    Inagaki, Yosuke

    1977-01-01

    Drift chamber is becoming an important detector in high energy physics as a precision and fast position detector because of its high spatial resolution and count-rate. The basic principle is that it utilizes the drift at constant speed of electrons ionized along the tracks of charged particles towards the anode wire in the nearly uniform electric field. The method of measuring drift time includes the analog and digital ones. This report describes about the construction of and the application of electric field to the drift chamber, mathematical analysis on the electric field and equipotential curve, derivation of spatial resolution and the factor for its determination, and selection of gas to be used. The performance test of the chamber was carried out using a small test chamber, the collimated β source of Sr-90, and 500 MeV/C electron beam from the 1.3 GeV electron synchrotron in the Institute of Nuclear Study, University of Tokyo. Most chambers to date adopted one dimensional read-out, but it is very advantageous if the two dimensional read-out is feasible with one chamber when the resolution in that direction is low. The typical methods of delay line and charge division for two dimensional read-out are described. The development of digital read-out system is underway, which can process the signal of a large scale drift chamber at high speed. (Wakatsuki, Y.)

  16. rn af veteraner

    DEFF Research Database (Denmark)

    Frederiksen, Signe; Lausten, Mette

    Siden starten af 1990’erne har Danmark sendt over 30.000 soldater og andet personel på internationale missioner – langt de fleste til Eks-Jugoslavien, Afghanistan og Irak. Denne undersøgelse handler om de børn, hvis fædre har været udsendt på militære missioner i udlandet. For hvordan håndterer...... spørgsmål er fokus for undersøgelsen. Undersøgelsen bygger på en spørgeskemaundersøgelse blandt børn af veteraner på henholdsvis 7, 11 og 15 år. Undersøgelsen er gennemført for og i samarbejde med Veterancentrets Videncenter, som er en del af Forsvarsministeriets Personalestyrelse....

  17. Wire Chamber

    CERN Multimedia

    Magnetoscriptive readout wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  18. Wire chamber

    CERN Multimedia

    1967-01-01

    Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  19. The high-sensitive magnetic levitated electrode ionization chamber of the noncontacting type

    International Nuclear Information System (INIS)

    Kawaguchi, Toshiro; Yoshimura, Atsushi

    1999-01-01

    There are two types of ionization chamber using magnetically levitated electrode: one is that by Tanaka et al. and the other, by authors'. The latter lacks the sensitivity relative to the former and thereby to solve the problem, authors made an improvement so that the electrode charge could be readout by noncontact after the leviated electrode was electrified by noncontact for an interval. This new type ionization chamber made it possible to measure the quite low dose radiation with stability and high sensitivity. Actually, the electrode was suspended by the teflon thread fixed on the steel cup levitated magnetically in the ionization chamber of which wall was covered by Al and equipped with an electrostatic charger for the electrode by noncontact. After measurement, the electrode was moved in the Faraday cage placed under the chamber to readout the voltage. For operation conditions of the apparatus, observation was done on the relationship between ionization current by 137 Cs and the applied voltage. For actual measurement, ionizations by low dose γ ray derived from KCl which containing 40 K in a small amount and by Rn at the fine and rainy days were measured. The exposure rate by KCl (500 g bottle) was found to be 12.7 x 10 -10 C/kg·h with the background value of 9.8 x 10 -10 . Rn concentrations in the air were 112.3 and 18.34 Bq/m 3 for 1 hr in the rainy and fine day, respectively, in Fukuoka City. (K.H.)

  20. Whole-body new-born and young rats' exposure assessment in a reverberating chamber operating at 2.4 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Wu Tongning; Hadjem, Abdelhamid; Wong, M-F; Gati, Azzedine; Wiart, Joe [Orange Labs R and D, Whist Lab 38-40 rue du General Leclerc, 92794 Issy-les-Moulineaux (France); Picon, Odile [Universite Paris-Est, ESYCOM, Cite Descartes 5, bd Descartes, 77454 Marne la Vallee Cedex 2 (France)], E-mail: joe.wiart@orange-ftgroup.com

    2010-03-21

    This paper presents the whole-body specific absorption rate (WBSAR) assessment of embryos and new-born rats' exposure in a reverberating chamber (RC) operating at 2.4 GHz (WiFi). The finite difference in time domain (FDTD) method often used in bio-electromagnetism is facing very slow convergence. A new simulation-measurement hybrid approach has been proposed to characterize the incident power related to the RC and the WBSAR in rats, which are linked by the mean squared electric field strength in the working volume. Peak localized SAR in the rat under exposure is not included in the content of the study. Detailed parameters of this approach are determined by simulations. Evolutions for the physical and physiological parameters of the small rats at different ages are discussed. Simulations have been made to analyse all the variability factors contributing to the global results. WBSAR information and the variability for rats at different ages are also discussed in the paper.

  1. Ionization chamber

    International Nuclear Information System (INIS)

    1977-01-01

    An improved ionization chamber type X-ray detector comprises a heavy gas at high pressure disposed between an anode and a cathode. An open grid structure is placed next to the anode and is maintained at a voltage intermediate between the cathode and anode potentials. The electric field which is produced by positive ions drifting towards the cathode is thus shielded from the anode. Current measuring circuits connected to the anode are, therefore, responsive only to electron current flow within the chamber and the recovery time of the chamber is shortened. The grid structure also serves to shield the anode from electrical currents which might otherwise be induced by mechanical vibrations in the ionization chamber structure

  2. Retirement Financial Planning and the RN: An Integrative Literature Review.

    Science.gov (United States)

    Keele, Shanna; Alpert, Patricia T

    2015-10-01

    This integrative literature review examined the current research on RN retirement. The review identified 3 critical gaps in knowledge: (a) minimal knowledge regarding the economic impact on RN retirement, (b) incomplete information regarding the demographics of RN retirement, and (c) a scarcity of prospective longitudinal RN workforce studies. Future research must address these gaps to better address RN workforce sustainability.

  3. Primary measuring of equipment factor of 222Rn/220Rn indoor

    International Nuclear Information System (INIS)

    Liu Yanyang; Liu Fudong; Wang Chunhong; Sheng Mingwei

    2010-01-01

    The activity concentration of 222 Rn, 220 Rn and their progenies of certain working places and dwellings in Baotou city were measured simultaneously. Based on these results, the equipment factor of 222 Rn is 0.35 for working places and 0.43 for dwellings, while equipment factor of 220 Rn measured at 20 cm distance from wall is 0.030 for both working places and dwellings. Preliminary results show that the temporal change of 220 Rn equilibrium equivalent concentration is same as 222 Rn which is high in midnight and low in afternoon,and significant difference between instant and accumulated measure result of 222 Rn, 220 Rn activity concentration is found, with the factor of 2.1 and 1.7. (authors)

  4. Mere Musik til Byens Børn

    DEFF Research Database (Denmark)

    Holst, Finn

    Førsteårsrapport på København Kommunes treårige projekt Mere Musik til Byens Børn - et pilotprojekt med henblik på at sikre, at flere børn i København får mulighed for at deltage i forskellige former for frivillig musikundervisning. Særligt fokuseres der på at fremme, at alle børn i hele byen...

  5. Delebørn i tal

    DEFF Research Database (Denmark)

    Ottosen, Mai Heide; Mathilde Hansen Stage, Sofie

    Hvordan påvirker samværsordninger børns hverdagsliv? Fungerer forældresamarbejdet anderledes, når der er en deleordning, og trives børn med udstrakt samvær bedre eller dårligere end andre skilsmissebørn? Med udgangspunkt i SFI’s Børneforløbsundersøgelse, som følger 6000 børn fra 1995, bliver der ...

  6. Minoritetsdanske børn i dagtilbud

    DEFF Research Database (Denmark)

    Tireli, Üzeyir

    2015-01-01

    Dagtilbud skal fremme børns trivsel, sundhed, udvikling og læring, Dette er et lovmæssig krav, som gælder for alle børn i Danmark. Minoritetsdanske børn anderledes grundvilkår giver dog store udfordringer for dagtilbuddene - for hvordan sikrer man, at også børn fra kulturelle minoriteter får opti...

  7. Interview med børn

    DEFF Research Database (Denmark)

    Interview med børn handler om børneinterview i forbindelse med forskning. Bogen er tænkt som inspiration til og afsæt for metodiske refleksioner i forbindelse med inddragelse af børn som informanter.......Interview med børn handler om børneinterview i forbindelse med forskning. Bogen er tænkt som inspiration til og afsæt for metodiske refleksioner i forbindelse med inddragelse af børn som informanter....

  8. Calibration factor determination for solid nuclear track detectors CR-39 type exposed to Rn-222

    International Nuclear Information System (INIS)

    Cazula, Camila Dias; Campos, Marcia Pires de; Mazzilli, Barbara Paci

    2014-01-01

    In the detection method with solid nuclear track detector, when a heavy particle rests on the detector surface, causes a breakdown in their molecular structure forming a trace. One of the typical applications of these detectors is the measurement of the concentration of Rn -222 in air, a noble radioactive gas, part of the U-238 series, emitting alpha particles and important in epidemiological studies to protect individuals from natural radiation. To determine the concentration of Rn -222 in the air in a room is necessary to know the density of lines (traces / cm 2 ) on the detector surface, the exposure time and the calibration factor. The determination of the calibration factor for CR-39 detectors was taken from the exposure of these to a known concentration of Rn-222. Therefore, the detectors were placed inside a cell of Lucas adapted and subsequently exposed to a concentration of Rn-222 15 kBq / m 3 , by means of the apparatus RN-150 Pylon Electronics Incorporation, which has a source of Ra-226 and releases known concentrations of Rn-222. Six calibration factor determinations were performed, the average value obtained was 0.0534 ±0.0021 (traces / cm 2 per Bq / m 3 day). The results are consistent with literature values for the same type of detector and showed good reproducibility

  9. Detection of 222Rn and 226Ra in environmental samples by scintillation method

    International Nuclear Information System (INIS)

    Zafimanjato, J.L.R.; Raoelina Andriambololona; Mobius, S.

    2009-01-01

    222 Rn is considered as the major source of radiological exposure of natural radiations to the population. It represents about the half of exposures of natural radiation sources in the world (UNSCEAR, 1993). 222 Rn gets into human body with inhaled air and sometimes with drinking water. Then, the objective of this work is to know the 222 Rn concentrations in water and in indoor atmosphere, and the risk in order to set up a method of monitoring and to identify high radon level areas. A specific method of detection using liquid scintillation with special emphasis on α/β discrimination, the use of solvent extractive and enrichment of radionuclides have been developed for the determination of both 222 Rn and 226 Ra in water. The method is simple, rapid and sensitive. It was shown that the proposed method was suitable for a large scale monitoring and routine analysis. Considerable concentrations of 222 Rn were found in water and air samples from Vinaninkarena - Antsirabe. 222 Rn concentrations obtained by in situ and in laboratory measurements have been compared to the results of an international intercomparison campaigns organised by the German Society for Liquid Scintillation Spectrometry in 2001. An assesment model of the dose due to ingestion and liberation of radon from water is presented and compared with other models especially to the Crawford Brown's model.

  10. Plate-out rates of radon progeny and particles in a spherical chamber

    International Nuclear Information System (INIS)

    Cheng, Y.S.; Chen, B.T.

    1990-01-01

    In indoor and mining environments, deposition or ''plate-out'' of radon progeny onto walls occurs simultaneously with attachment of the radon progeny to airborne particles. Attachment and plate-out processes affect the atmosphere in which radon exposures takes place by reducing concentrations and shifting activity size distributions. Both processes have important consequences in determining the deposition pattern and initial dose of inhaled radon progeny. Theoretical deposition models show that turbulence and natural convection in a room are the major factors that influence plate-out rates. Here we describe plate-out measurements for radon progeny and aerosol particles in a spherical chamber under controlled laboratory conditions. The temperature and velocity profiles in still and turbulent air were monitored. A 161-liter spherical aluminum chamber was used to study the mixing. During mixing, air velocity was detected when rotational speeds were higher than 500 rpm. Monodisperse silver aerosols and polystyrene latex particles in the size range of 5 nm to 2 μm were used in the deposition study. Radon-220 progeny were generated by passing Rn-220 gas into the chamber and letting the gas decay into 212 Pb. The deposition rates of the particles and radon progeny ( 212 Pb) in the chamber were determined by monitoring the concentration decay of the aerosol as a function of time

  11. Environmental thoron (220Rn): a review

    International Nuclear Information System (INIS)

    Ramachandran, T.V.

    2013-01-01

    Ever since studies on uranium miners established the presence of a positive risk coefficient for the occurrence of lung cancer in miners exposed to elevated levels of 222 Rn and its progeny, there was a great upsurge of interest in the measurement of 222 Rn in the environment and considerable data is generated on the levels of 222 Rn in the environment across the worlds and is periodically reported by UNSCEAR. In contrast to this, data pertaining to 220 Rn in indoors and workplace environment is scare due to the general perception that its levels are negligible due to its shorter half life, and subsequently its contribution to the total inhalation dose is ignored, in the presence of other significant sources of natural radiation. Many locations have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products like radon ( 222 Rn), and thoron ( 220 Rn) in the environment. It is estimated inhalation of 222 Rn, 220 Rn and their short lived progenies contribute more than 54 % of the total natural background radiation dose received by the general population. This component is not adequately estimated for any country so far on a national level. 220 Rn problem will also be a problem in industries which uses thorium nitrate. Including India lamps using thoriated gas mantles are being still used for indoor and outdoor lighting and hawkers in rural as well as urban areas. Considering the fact that large amount of thorium nitrate is being handled by these industries, contribution to the inhalation dose of workers from 220 Rn gas emanated and build up of the progeny in ambient air may also be quite significant. In this article current status of 220 Rn levels in the indoor environment workplaces as well as in other industries where large amount of 232 Th is being handled are being summarized. (author)

  12. Geodesics in (Rn, d1

    Directory of Open Access Journals (Sweden)

    Mehmet KILIÇ

    2016-09-01

    Full Text Available The notion of geodesic, which may be regarded as an extension of the line segment in Euclidean geometry to the space we study in, has an important place in many branches of geometry, such as Riemannian geometry, Metric geometry, to name but a few. In this article, the concept of geodesic in a metric space will be introduced, then geodesics in the space (Rn, d1 will be characterized. Furthermore, some examples will be presented to demonstrate the effectiveness of the main result.

  13. Cloud Chamber

    DEFF Research Database (Denmark)

    Gfader, Verina

    Cloud Chamber takes its roots in a performance project, titled The Guests 做东, devised by Verina Gfader for the 11th Shanghai Biennale, ‘Why Not Ask Again: Arguments, Counter-arguments, and Stories’. Departing from the inclusion of the biennale audience to write a future folk tale, Cloud Chamber......: fiction and translation and translation through time; post literacy; world picturing-world typing; and cartographic entanglements and expressions of subjectivity; through the lens a social imaginary of worlding or cosmological quest. Art at its core? Contributions by Nikos Papastergiadis, Rebecca Carson...

  14. wire chamber

    CERN Multimedia

    1985-01-01

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  15. Wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  16. wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  17. wire chamber

    CERN Multimedia

    Was used in ISR (Intersecting Storage Ring) split field magnet experiment. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  18. Relationship of 220Rn and 222Rn progeny levels in Canadian underground U mines

    International Nuclear Information System (INIS)

    Bigu, J.

    1988-01-01

    Radon-222 and 220 Rn progeny are found in some Canadian underground U mines. Because both can contribute to lung dose, their experimental determinations are important. The relationship between 222 Rn progeny Working Level [WL(Rn)] and 220 Rn progeny Working Level [WL(Tn)] has been investigated in U mines. Experimental measurements extended from 1981 to 1986 and consisted of about 700 measurements of each WL(Rn) and WL(Tn). The data were analyzed by standard linear and power-function regression analysis. A power-function relationship between WL(Rn) and WL(Tn) seemed to fit the experimental data best. The relationship obtained permits the calculation of WL(Tn) from experimental values of WL(Rn). The relationship is useful for lung-dose-calculation purposes and in mine-ventilation-engineering calculations

  19. Fremtidens biblioteksbetjening af børn

    DEFF Research Database (Denmark)

    Høyrup, Helene

    2008-01-01

    Rapporten er resultatet af et tværministerielt udvalgsarbejde nedsat af Kulturministeriet.  Kommissoriet har været at nytænke biblioteksbetjeningen af børn, så den passer til vidensamfundet.  Udvalgsarbejdet munder ud i ti bud for fremtidens biblioteksbetjening af børn....

  20. Valence configurations in 214Rn

    International Nuclear Information System (INIS)

    Dracoulis, G.D.; Byrne, A.P.; Stuchbery, A.E.; Bark, R.A.; Poletti, A.R.

    1987-01-01

    Excited states of 214 Rn, up to spins of ≅ 24 ℎ have been studied using γ-ray and electron spectroscopy following the 208 Pb( 9 Be,3n) 214 Rn reaction. The level scheme (which differs substantially from earlier work) is compared with the results of a semi-empirical shell model calculation. The availability of high-spin orbitals for the four valence protons and two valence neutrons, and the effect of the attractive proton-neutron interaction, leads to the prediction of high-spin states at an unusually low excitation energy. Experimentally, the high level density leads to difficulties in the level scheme assignments at high spin. Nevertheless, configuration assignments, supported by transition strengths deduced from the measured lifetimes (in the nanosecond region) are suggested for the main yrast states. The decay properties also suggest that configuration mixing is important. The possibility of a gradual transition to octupole deformation, implied by the decay properties of the 11 - and 10 + yrast states is also discussed. (orig.)

  1. Study on a charcoal-based monitor for Rn-220 in air

    International Nuclear Information System (INIS)

    Yu Yiqiao; Solomon, S.B.

    1993-01-01

    Activated charcoal has been used in both passive monitors (Cohen, Pondy et al. 1987) and active monitors (Solomon and Gan, 1989) for the measurements of 222 Rn in air. Cooled, charcoal-impregnated filters, viewed in-situ by a solid state alpha detector, have been used for 220 Rn-in-breath studies. In general, γ ray counting of 220 Rn samples collected on activated charcoal has not been used. This paper describes the development and calibration of a charcoal based monitor designed to measure 220 Rn levels down to a lower limit of 10 Bq m -3 over sampling periods of 4 to 15 h. The activity of 212 Pb (10.6 h) produced from 220 Rn (55.6 s) collected in an activated charcoal-based sampler is 1/700 the total 220 Rn activity. A typical Hp-Ge detector has a MDL for a two-hours count of approximately 0.1 Bq of 212 Pb for the 239 keV γ-ray. For a MDL of 10 Bq·m -3 of 220 Rn in air, a volume of at least 7 m 3 must be sampled, assuming no breakthrough. The present charcoal-based 220 Rn monitor is designed to maximize the path length through the activated charcoal while sufficient cross-sectional area is retained to allow flow rates up to 0.03 m 3 ·kg -1 is packed into a specially designed aluminum container. The container is modeled on a Marinelli beaker to maximize the counting efficiency, while the sample flow through the chambers of the monitor is optimized to maintain radial symmetry. experiments demonstrated that 94% of 220 Rn was adsorbed by the charcoal in the monitor under a flow rate of 0.03 m 3 ·min -1 at 25 degree C and 85%. RH in 15 h. The monitor is designed to fit over a 70 mm diameter Hp-Ge detector. Preliminary measurements of 220 Rn in two buildings and a cave, using the active monitors and 'grabing' samples under a flow rate of 0.03 m 3 ·min -1 and a period of 4 h, indicated concentrations of between 18.6 and 142.0 Bq·m 3

  2. Analysis of international intercomparisons results organized by Japan for integrating 222Rn-220Rn detectors

    International Nuclear Information System (INIS)

    Wu Yunyun; Cui Hongxing; Zhang Qingzhao; Shang Bing; Su Xu

    2012-01-01

    Objective: To guarantee the quality of measurements with the radon-thoron discriminative detectors of our laboratory. Methods: LD-P radon-thoron discriminative detector participated in the international intercomparison for integrating radon/thoron detectors organized by National Institute of Radiological Science (NIRS, Japan). Detectors were sent to NIRS for exposure. Radon intercomparison was conducted with radon chamber providing three levels of exposure: low, medium and high levels. Thoron intercomparison was carried out at thoron chamber, which also provided three levels of exposure: low, medium and high levels. Detectors were posted back to our laboratory for etching and analysis after exposure. Then the measured values were submitted to NIRS. Finally the reference values were informed of us. Results: The relative percent difference (RPD) between the measured value and the reference value for radon was -13.8%, -14.4% and -17.1% at low, medium and high levels respectively, and that of thoron were -14.4%, 8.9% and -3.2% at three levels respectively. Conclusions: Both radon and thoron measurement of our detectors rank as 'Category Ⅰ' in the 4th international intercomparisons for integrating radon/thoron detectors with the NIRS radon/thoron chambers. (authors)

  3. Occurrence of 222Rn and progeny in natural gas processing plants in western Canada

    International Nuclear Information System (INIS)

    Drummond, I.; Boucher, P.; Bradford, B.; Evans, H.; McLean, J.; Reczek, E.; Thunem, H.

    1990-01-01

    In Western Canada, there are many plants that process natural gas to remove impurities (CO 2 , H 2 S, H 2 O) and recover natural gas liquids (propane, butane, etc.). Trace quantities of 222 Rn present in the inlet stream are concentrated in streams rich with propane. Potential hazards to plant operators include direct inhalation of 222 Rn and progeny; exposure to gamma radiation from short-lived progeny deposited inside equipment; or inhalation of 210 Pb when contaminated equipment is opened for repair. Twenty-four plants operated by seven companies cooperated to assess these potential hazards. The findings indicate a substantial flux of 222 Rn and progeny passing through the plants, but little accumulation of radionuclides. In no case was there evidence of significant exposure of plant operators or maintenance personnel to ionizing radiation. Further investigation of pipeline operations, and chemical operations using natural gas liquids as feed stock, is recommended

  4. Results of long-term measurement of 222Rn concentrations in outdoor atmosphere

    International Nuclear Information System (INIS)

    Holy, K.; Boehm, R.; Polaskova, A.; Hola, O.

    1998-01-01

    Results are reported of the authors' long-term measurement of 222 Rn concentrations in the outdoor atmosphere. The measurements started in 1987 and were performed at a height of 1.5 m over a grass-covered ground surface, using till 1991 a Lucas type scintillation chamber and later a large volume scintillation chamber. Graphs are presented and discussed of the course of average monthly radon concentration in 1987-1996 and of annual courses of radon concentration for different time intervals of the day over 1991 to 1995. (A.K.)

  5. Concentration of 222Rn in drinking water of the Zacatecas City, measured by liquid scintillation and associated dose

    International Nuclear Information System (INIS)

    Arevalo B, C. A.; Lopez del R, H.; Davila R, J. I.; Mireles G, F.; Pinedo V, J. L.; Rios M, C.; Saucedo A, S. A.

    2017-09-01

    A study was carried out to determine the concentration of 222 Rn in samples of drinking water collected from different homes in the Zacatecas city, Mexico, whose main source of supply is groundwater. The 222 Rn radioactive gas is a product of the decay series of 238 U and is considered one of the main sources of natural radiation, since it contributes almost half of the radiation dose that a person will receive throughout his life. The 222 Rn originates in the rocks of the aquifers and dissolves in the water, which is later integrated into the distribution network of the public supply that supplies the entire population. Exposure to ionizing radiation that 222 Rn and its offspring emit can damage the DNA molecule, inducing the possible appearance of cancer. Has been demonstrated by various epidemiological studies carried out in uranium mines workers in different parts of the world, that this exposure increases the incidence of lung cancer, placing 222 Rn and their offspring as the second main cause of this type of cancer, after smoking habit. Using the technique of solvent extraction of 222 Rn in water and liquid scintillation spectrometry, water collected from 14 different households was sampled and analyzed. The average of the measured activity of 222 Rn was 2.09 Bq/L and the annual effective dose per water intake attributable to that concentration of 6.07 mSv/a. The concentration of 222 Rn in water and the annual effective dose are below 11 Bq/L and 50 mSv/a, such concentrations are the maximum limits established by the Unites States Environmental Protection Agency (US EPA) and the ICRP, respectively. The concentration of 222 Rn that is transferred from the water to the air inside a house was also calculated and the radiation dose that this concentration causes by inhalation, being 0.209 Bq/m 3 and 1,463 μ Sv a, respectively. (Author)

  6. High-spin yrast isomers in 211Rn and 212Rn with enhanced E3 decays

    International Nuclear Information System (INIS)

    Dracoulis, G.D.; Byrne, A.P.; Fabricius, B.

    1990-01-01

    New isomeric states with J π =69/2 + ,τ m = 13 (1) ns in 211 Rn and J π =33 - ,τ m = 7(1) ns in 212 Rn have been identified. They decay by enchanced E3 transitions with strengths of 33(3) and 43(6) single particle units to the known 63/2 - and 30 + isomers 211 Rn and 212 Rn, respectively. The excitation energies and transition strengths agree well with predictions of the multi-particle, octupole-vibration coupled model. 13 refs., 2 tabs., 3 figs

  7. Monte Carlo simulation of semiconductor detector response to "2"2"2Rn and "2"2"0Rn environments

    International Nuclear Information System (INIS)

    Irlinger, J.; Trinkl, S.; Wielunksi, M.; Tschiersch, J.; Rühm, W.

    2016-01-01

    A new electronic radon/thoron monitor employing semiconductor detectors based on a passive diffusion chamber design has been recently developed at the Helmholtz Zentrum München (HMGU). This device allows for acquisition of alpha particle energy spectra, in order to distinguish alpha particles originating from radon and radon progeny decays, as well as those originating from thoron and its progeny decays. A Monte-Carlo application is described which uses the Geant4 toolkit to simulate these alpha particle spectra. Reasonable agreement between measured and simulated spectra were obtained for both "2"2"0Rn and "2"2"2Rn, in the energy range between 1 and 10 MeV. Measured calibration factors could be reproduced by the simulation, given the uncertainties involved in the measurement and simulation. The simulated alpha particle spectra can now be used to interpret spectra measured in mixed radon/thoron atmospheres. The results agreed well with measurements performed in both radon and thoron gas environments. It is concluded that the developed simulation allows for an accurate prediction of calibration factors and alpha particle energy spectra. - Highlights: • A method was developed to simulate alpha particle spectra from radon/thoron decay. • New monitor features alpha-particle-spectroscopy based on silicon detectors. • A method is presented to quantify radon/thoron concentrations in mixed atmospheres. • The calibration factor can be simulated for various environmental parameters.

  8. Intercomparison of Rn-222 determination from groundwater

    DEFF Research Database (Denmark)

    Vesterbacka, P.; Pettersson, H.; Hanste, U.-M.

    2010-01-01

    An intercomparison exercise on Rn-222 determination in groundwater was organized between eight Nordic laboratories. The individual laboratory results were in most cases within 20% of the median value and within reported uncertainties. Considering the particular difficulties in preparing, transpor......An intercomparison exercise on Rn-222 determination in groundwater was organized between eight Nordic laboratories. The individual laboratory results were in most cases within 20% of the median value and within reported uncertainties. Considering the particular difficulties in preparing...

  9. Chamber transport

    International Nuclear Information System (INIS)

    Olson, Craig L.

    2001-01-01

    Heavy ion beam transport through the containment chamber plays a crucial role in all heavy ion fusion (HIF) scenarios. Here, several parameters are used to characterize the operating space for HIF beams; transport modes are assessed in relation to evolving target/accelerator requirements; results of recent relevant experiments and simulations of HIF transport are summarized; and relevant instabilities are reviewed. All transport options still exist, including (1) vacuum ballistic transport, (2) neutralized ballistic transport, and (3) channel-like transport. Presently, the European HIF program favors vacuum ballistic transport, while the US HIF program favors neutralized ballistic transport with channel-like transport as an alternate approach. Further transport research is needed to clearly guide selection of the most attractive, integrated HIF system

  10. Distribution Log Normal of 222 Rn in the state of Zacatecas, Mexico

    International Nuclear Information System (INIS)

    Garcia, M.L.; Mireles, F.; Quirino, L.; Davila, I.; Rios, C.; Pinedo, J.L.

    2006-01-01

    In this work the evaluation of the concentration of 222 Rn in air for Zacatecas is shown. The Solid State Nuclear Track Detectors were used as the technique for the realization of the measurements in large scale with cellulose nitrate LR-115, type 2, in open chambers of 222 Rn. The measurements were carried out during three months in different times of the year. In the results it is presented the log normal distribution, arithmetic mean and geometric media for the concentration at indoor and outdoor of residence constructions, the concentration at indoor of occupational constructions and in the 57 municipal heads of the state of Zacatecas. The statistics of the values in the concentration showed variation according to the time of the year, obtaining high quantities in winter seasons for both cases. The distribution of the concentration of 222 Rn is presented in the state map for each one of the municipalities, representing the measurement places in the entire state of Zacatecas. Finally the places where the values in the concentration of 222 Rn in air are near to the one limit settled down by the EPA of 148 Bq/m 3 are presented. (Author)

  11. (222)Rn activity in groundwater of the St. Lawrence Lowlands, Quebec, eastern Canada: relation with local geology and health hazard.

    Science.gov (United States)

    Pinti, Daniele L; Retailleau, Sophie; Barnetche, Diogo; Moreira, Floriane; Moritz, Anja M; Larocque, Marie; Gélinas, Yves; Lefebvre, René; Hélie, Jean-François; Valadez, Arisai

    2014-10-01

    One hundred ninety-eight groundwater wells were sampled to measure the (222)Rn activity in the region between Montreal and Quebec City, eastern Canada. The aim of this study was to relate the spatial distribution of (222)Rn activity to the geology and the hydrogeology of the study area and to estimate the potential health risks associated with (222)Rn in the most populated area of the Province of Quebec. Most of the groundwater samples show low (222)Rn activities with a median value of 8.6 Bq/L. Ninety percent of samples show (222)Rn activity lower than 100 Bq/L, the exposure limit in groundwater recommended by the World Health Organization. A few higher (222)Rn activities (up to 310 Bq/L) have been measured in wells from the Appalachian Mountains and from the magmatic intrusion of Mont-Saint-Hilaire, known for its high level of indoor radon. The spatial distribution of (222)Rn activity seems to be related mainly to lithology differences between U-richer metasediments of the Appalachian Mountains and magmatic intrusions and the carbonaceous silty shales of the St. Lawrence Platform. Radon is slightly enriched in sodium-chlorine waters that evolved at contact with clay-rich formations. (226)Ra, the parent element of (222)Rn could be easily adsorbed on clays, creating a favorable environment for the production and release of (222)Rn into groundwater. The contribution of groundwater radon to indoor radon or by ingestion is minimal except for specific areas near Mont-Saint-Hilaire or in the Appalachian Mountains where this contribution could reach 45% of the total radioactive annual dose. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Dependence of indoor 222Rn level on building materials

    International Nuclear Information System (INIS)

    Tso, M.W.; Ng, C.; Leung, J.K.C.

    1993-01-01

    The radionuclide contents of typical building materials used in Hong Kong were studied by γ spectroscopic analysis. The physical properties of these building materials affecting the production and transportation of 222 Rn to the surrounding air were examined; these include the emanation coefficient of 2 '2 2 Rn of the material, the diffusion coefficient of 222 Rn in the material and the effect of surface coating and temperature on the rate of 222 Rn exhalation. Results obtained in this study explain the indoor 222 Rn concentration observed in our previous surveys and also suggest that the main source of indoor 222 Rn in Hong Kong is building material. (3 figs., 4 tabs.)

  13. Recent Swedish experiences in 222Rn control

    International Nuclear Information System (INIS)

    Swedjemark, G.A.; Maekitalo, A.

    1990-01-01

    Swedish local authorities are responsible for decreasing 222 Rn progeny concentrations in homes in their municipalities. To obtain an overall view of their experiences, concerned national authorities sent a questionnaire in 1986 to local authorities. The results were intended to form one basis for decisions by the government regarding revised statements on financial contributions, limits, etc. The results were also intended to be of use to national authorities in determining limits and recommendations and to local authorities in their field work. One result of the survey was an enhanced interest in the Rn problem among Swedish politicians and the mass media. This increased attention resulted in new plans for continued work to decrease Rn levels indoors during 1987-1989, on both a national and a local level. The experiences of the local authorities show that Rn progeny concentrations decreased to below the design level in 95% of newly built houses investigated. It was also found that Rn progeny concentrations were below the limit for reconstruction in 53% of existing homes that previously had levels exceeding the limit

  14. Direct determination of 222Rn gas using the electret to remove daughters at formation. Annual progress report, June 1, 1981-May 31, 1982

    International Nuclear Information System (INIS)

    Harley, N.H.

    1982-01-01

    This report covers progress made from 1 June 1981 to 31 May 1982 in developing a continuous monitor which measures only 222 Rn without interference from the daughters. Five 222 Rn counters have been built which determine 222 Rn alone by alpha scintillation counting in the presence of an electret to remove the short-lived daughter products from the counting chamber. The chamber design is based on the work of Chittaporn et al., (1981) at New York University's Department of Environmental Medicine. The detection chamber is a 1.8 liter (12.7 cm diameter by 14 cm high) cylinder lined with zinc sulfide alpha phosphor. The detector sits directly on a 12.7 cm diameter phototube. The 5 units have calibration factors which range from 155 to 186 counts/hour per pCi 222 Rn/liter and an average background count of 6 counts/hour. The lower limit of detection for a one hour count is thus 0.03 pCi 222 Rn/l, well below environmental levels

  15. RF Anechoic Chambers, Tri-Service Research Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — In collaboration with the Navy, there are 12 RF Anechoic and static free exposure chambers located at TSRL. These chambers cover the majority of the RF spectrum and...

  16. Preliminary evaluation of 222Rn levels in homes and offices in two different regions in Syria

    International Nuclear Information System (INIS)

    Othman, I.; Hushari, M.A.; Raja, G.

    1993-01-01

    Evaluation of Rn levels was carried out in homes and offices in Damascus and phosphate mining areas near Palmyra city in Syria. The AEOI radon diffusion dosimeters were used in this study. Electrochemical etching of polycarbonate detectors was used to develop the tracks. A standard source of radon was used for calibration. Radon levels were measured in 98 homes of workers in the phosphate mining areas and 29 homes in the Damascus region. The radon diffusion chambers were placed in offices and laboratories of AEC for about four months in average. The results gave an indication of Rn level in Damascus dwellings in spite of the necessity for further comprehensive studies for the city. The radon levels were high in some offices and laboratories where phosphate analyses are carried out or buildings near phosphate storage areas or near surface phosphate rocks occurrence, in comparison with homes. (author). 7 refs, 4 figs, 2 tabs

  17. Rn 222 in the Black Sea waters

    International Nuclear Information System (INIS)

    Arbuzova, A.P.; Batrakov, G.F.; Eremeev, V.N.; Zemlyanoj, A.D.; Ivanova, T.M.

    1988-01-01

    Results of Rn 222 concentration measurements in the Black Sea waters obtained in the summer of 1986 during the expedition of the Akademik Vernadskij research ship are presented. It is ascertained that the intensity of vertical turbulent exchange produces the main effect on Rn 222 distribution in the sea surface waters. The vertical distribution in a 200 m layer is characterized by the growth of concentration with depth, which is caused by the presence of Ra 226 increased concentration region, that coincides with the boundary layer between oxygen and hydrogen sulfide

  18. rn Utzon -Influences and Reinterpretation

    DEFF Research Database (Denmark)

    Carter, Adrian

    2012-01-01

    The Paper presents a study of Jørn Utzon's architecture, in terms of its response to both local context and transcultural influences. The paper shows Utzon to have been a precursor and direct influence upon subsequent developments within contemporary regional architecture.......The Paper presents a study of Jørn Utzon's architecture, in terms of its response to both local context and transcultural influences. The paper shows Utzon to have been a precursor and direct influence upon subsequent developments within contemporary regional architecture....

  19. Seasonal and diurnal variation of outdoor radon (222Rn) concentrations in urban and rural area with reference to meteorological conditions

    International Nuclear Information System (INIS)

    Podstawczynska, A.; Pawlak, W.; Kozak, K.; Mazur, J.

    2010-01-01

    The objective of the study was to investigate temporal variability of outdoor radon ( 222 Rn) concentration registered in the center of Lodz (urban station), at Ciosny (rural station) and Krakow (suburban station) in relation to meteorological parameters (i.e. air temperature, temperature vertical gradient, wind speed, soil heat flux, volumetric water content in soil) with special consideration of urban-rural differences. Continuous measurements of 222 Rn concentration (at 60 min intervals) were performed at a height of 2 m above the ground using AlphaGUARD PQ2000PRO (ionization chamber) from January 2008 to May 2009. 222 Rn levels were characterized by a diurnal cycle with an early morning maximum and a minimum in the afternoon. The well-marked 24 h pattern of radon concentration occurred in summer at anticyclonic weather with cloudless sky, light wind and large diurnal temperature ranges. The urban measurement site was characterized by the lowest atmospheric 222 Rn concentration and an urban-rural differences of radon levels increased from winter to summer and during the nighttime periods. The maximum contrasts of 222 Rn levels between Lodz and Ciosny, reaching - 30 Bq m -3 , were registered in June and July during the urban heat island (UHI) phenomenon (a positive thermal anomaly of a city if compared to rural area) and strong thermal inversion near the ground in the rural area. (authors)

  20. Doriot Climatic Chambers

    Data.gov (United States)

    Federal Laboratory Consortium — The Doriot Climatic Chambers are two, 60-feet long, 11-feet high, 15-feet wide chambers that are owned and operated by NSRDEC. The Doriot Climatic Chambers are among...

  1. Dosimetry of Rn-222 in the air in environments located above and below ground level

    International Nuclear Information System (INIS)

    Cazula, Camila Dias

    2015-01-01

    Exposure of the general population to ionizing radiation comes mainly from natural sources. The main contribution is due to inhalation of radon (Rn-222), a gas that occurs naturally (UNSCEAR, 2000). The Rn-222 concentration in the environment is controlled by factors such as soil permeability and water content, the weather variability, materials used in the foundation and the usual positive pressure differential between the soil and the internal environment. Studies indicate that the concentration of radon shows a wide variation in the basement, ground floor and upper floors of buildings. The objective of this study is to determine radon levels in basements, ground floor and floors above ground level, at a university in the city of Sao Paulo and in one residential building in the city of Peruibe. Rn-222 measurements were performed using the method with nuclear track of solid state detectors (CR-39). The studied environments present Rn-222 concentration well below the values recommended by the International Commission on Radiological Protection, published in the 2009 document, of 300 Bq/m 3 for homes and 1000 Bq/m 3 for the workplace. In the residential building, the concentration of Ra-266, Th-232 and K-40 in the materials used in the building construction was also analyzed, by gamma spectrometry. The effective total dose for the resident due to external exposure was 0.8 mSv y -1 , lower than the annual dose limit for the general public of 1 mSv y -1 . (author)

  2. Measurements of indoor 222Rn concentration in two art galleries

    International Nuclear Information System (INIS)

    Carneiro, Luana Gomes; Braz, Delson; Jesus, Edgar Francisco de; Cunha, Kenya Dias da; Medeiros, Geiza; Zouain, Felipe; Pitassi, Gabriel; Leite, Carlos Barros; Cardoso, Katia

    2009-01-01

    It is point out that radon and their decay products in environment give high dose to human lung. Studies indicate that the indoor radon inhalation by humans has been considered probably the second most important cause of lung cancer after of smoking. A passive-type radon detector was used for measuring indoor radon concentration in two art galleries at Rio de Janeiro city during 90 days January to March, 2009. The aim of this study is to evaluate the occupational and public radon exposure in art galleries and museums. This paper shows the preliminary results of samples collected at two art galleries located in Gavea, Rio de Janeiro city. 30 LEXAN (GE) track detectors were exposed in the air (indoor as well as outdoor). The samples were collected in the same building which is a construction of XIX century. The analysis of the results suggests that the 222 Rn concentration levels are different in both sampling site, in closed environmental, demonstrating that, although the construction materials are the same the absence of circulating air is a factor very important to increase the concentration of indoor Rn. (author)

  3. Directed Energy Anechoic Chamber

    Data.gov (United States)

    Federal Laboratory Consortium — The Directed Energy Anechoic Chamber comprises a power anechoic chamber and one transverse electromagnetic cell for characterizing radiofrequency (RF) responses of...

  4. Multiple chamber ionization detector

    International Nuclear Information System (INIS)

    Solomon, E.E.

    1980-01-01

    A multi-chambered ionisation detector enables the amount of radiation entering each chamber from a single radioactive, eg β, source to be varied by altering the proportion of the source protruding into each chamber. Electrodes define chambers and an extended radioactive source is movable to alter the source length in each chamber. Alternatively, the source is fixed relative to outer electrodes but the central electrode may be adjusted by an attached support altering the chamber dimensions and hence the length of source in each. Also disclosed are a centrally mounted source tiltable towards one or other chamber and a central electrode tiltable to alter chamber dimensions. (U.K.)

  5. Determination of Rn concentration in groundwater

    International Nuclear Information System (INIS)

    Takada, Shigeru; Handa, Madoka; Okano, Yasuhiro; Saito, Masaaki; Suzuki, Takashi

    1984-01-01

    The method of prediction of earthquakes by the change of concentration of Rn in groundwater was developed by U.S.S.R. and People's Republic of China, and was not known clearly. Since 1975, the research works on this subject were commenced by University of Tokyo, Geological Survey of Agency of Industrial Science and Technology and Tokyo Metropolitan Isotopic Research Center. Along with the development of an automatic continuous measuring apparatus with high reliability, the systems for the measurement of the Rn concentration in groundwater were established. At the time of the earthquake off Izu-Oshima on January 14, 1978, clear precursor was found in an artesian flowing well in Nakaizu 0f Izu Peninsula, and the unusual phenomena which seemed be the precursor of an earthquake were recognized in other districts of Izu and Tokai. On August 8, 1983, an earthquake of magnitude 6 occurred in the boundary region of Yamanashi and Kanagawa Prefectures. Preceding the earthquake, the unusual change of the concentration of Rn was recognized at several observation wells in Tokyo, and the unusual change was observed after the earthquake also. The possibility that the unusual change of the Rn concentration in groundwater is the precursor of earthquakes is high, and this phenomenon is expected to make contribution for the prediction of earthquakes, though there remain many problems to be solved. Further works are scheduled to establish the practical method of predicting earthquakes. (Isimitsu, A.)

  6. Dynamical Symmetry Breaking in RN Quantum Gravity

    Directory of Open Access Journals (Sweden)

    A. T. Kotvytskiy

    2011-01-01

    Full Text Available We show that in the RN gravitation model, there is no dynamical symmetry breaking effect in the formalism of the Schwinger-Dyson equation (in flat background space-time. A general formula for the second variation of the gravitational action is obtained from the quantum corrections hμν (in arbitrary background metrics.

  7. Vold mod børn

    DEFF Research Database (Denmark)

    Christensen, Else; Agerlund Sloth Larsen, Dorthe

    er der gennemført en interviewundersøgelse, hvor i alt 14 sagsbehandlere fra fire forskellige store kommuner er interviewet om deres erfaringer fra sager med (mistanke om) fysisk vold mod børn, om hvordan sådanne sager sædvanligvis starter i socialforvaltningen, om undersøgelsesforløbet, om...

  8. A Monte Carlo study of radon detection in cylindrical diffusion chambers

    Energy Technology Data Exchange (ETDEWEB)

    Rickards, Jorge, E-mail: rickards@fisica.unam.m [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Circuito de la Investigacion Cientifica, Ciudad Universitaria, Delegacion Coyoacan, 04520 Mexico, D.F. (Mexico); Golzarri, Jose-Ignacio, E-mail: golzarri@fisica.unam.m [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Circuito de la Investigacion Cientifica, Ciudad Universitaria, Delegacion Coyoacan, 04520 Mexico, D.F. (Mexico); Espinosa, Guillermo, E-mail: espinosa@fisica.unam.m [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Circuito de la Investigacion Cientifica, Ciudad Universitaria, Delegacion Coyoacan, 04520 Mexico, D.F. (Mexico)

    2010-05-15

    The functioning of radon diffusion chambers was studied using the Monte Carlo code RAMMX developed here. The alpha particles from radon are assumed randomly produced in the volume of the cylinder, and those from the progeny are assumed to originate randomly at the cylindrical surface. The energy spectrum, the distribution of incident angles, and the distribution of path lengths of the alpha particles on the detector were obtained. These quantities vary depending on input parameters such as initial alpha particle energy, radius and depth of the diffusion chamber, detector size and atmospheric pressure. The calculated energy spectrum for both {sup 222}Rn and {sup 220}Rn was compared with experiment, permitting the identification of each peak and its origin, and a better understanding of radon monitoring. Three aspects not considered in previous calculations are progeny alphas coming from surfaces of the monitor, taking into account the atmospheric pressure, and including the isotope {sup 220}Rn.

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

    International Nuclear Information System (INIS)

    Sciocchetti, G.; Cotellessa, G.; Soldano, E.; Pagliari, M.

    2006-01-01

    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 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 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)

  11. Variations of Rn-222 concentration in the Bratislava air

    International Nuclear Information System (INIS)

    Holy, K.; Bohm, R.; Polaskova, A.

    1996-01-01

    222 Rn is produced by alpha decay of 222 Ra in roil. A small fraction of totally produced 222 Rn escapes from coil particles into soil air. Then 222 Rn is transported predominantly by molecular diffusion into outdoor atmosphere. The radon concentration in the outdoor atmosphere is not stable. It varies irregularly depending on meteorological conditions. However there were found out regular daily and remand variations of 222 Rn concentration in outdoor atmosphere. These variations were measured in numerous works and results are summarized f.e. in work of Gesell. A simple model described the annual variations of 222 Rn concentration war published by Minato. A mathematical analysis of daily course of 222 Rn concentration in outdoor atmosphere was realized by Garzon et al. Some results of our study of 222 Rn variations in outdoor atmosphere of Bratislava are shown in this report. (author)

  12. A novel design of a personal nuclear track detector for ambient Rn

    International Nuclear Information System (INIS)

    Margaliot, M.; Even, O.; Herman, R.

    1997-01-01

    In some occupations, workers spend a part of their time underground, in closed and unventilated spaces, while most of their time is spent in the open air. The case in hand is a group of the 'Bezek' telephone technicians, whose work includes spending a few hours daily in small, coarsely finished and unventilated tunnels in which telephone branching boxes are located. The rest of their time they work outdoors, and a small part of it is spent in offices. The Rn levels in a few telephone branching tunnels were measured and were found to be rather high (levels of 3000 - 5000 Bq/m 3 are common). The average exposure of the workers is however much lower, due to short time spent in the tunnels, versus the longer time spent outdoors, and the low Rn level there. To obtain a well founded estimation of their actual commutative Rn exposure, a new integrative Rn detector was designed, which is attached to the workers clothing during the whole working day, and serves as a personal Rn detector, rather than as the a conventional area monitor. The detector element itself consists of a Nuclear Track Detector made of dosimetry grade CR-39. The function of the detector is how ever dependent mainly on the geometrical design of the housing of the detector. The properties of these detectors are, however, highly dependent on the design of the detectors housing.The design itself, it's theoretical efficiency, it's actual calibration process and it's calibration factor are presented. Mechanical reliability has been established in some 3 years of operation both as a fixed area monitor and as a personal portable detector. (authors)

  13. Performance improvements on passive activated charcoal 222Rn samplers

    International Nuclear Information System (INIS)

    Wei Suxia

    1996-01-01

    Improvements have been made on passive activated charcoal 222 Rn samplers with sintered metal filters. Based on the samplers of good adaptability to temperature and humidity developed before, better charcoal was selected to further improve their performance in radon absorption ability and moisture-resistance. And charcoal quantity in samplers was strictly controlled. The integration time constant of the improved samplers was about 4.3 days. As the sampler was combined with gamma spectrometer to measure radon concentration, the calibration factor was 0.518 min -1 ·Bq -1 ·m 3 for samplers of 7 days exposure time, and the minimum detectable concentration 0.28 Bq·m -3 if counting time for both background and sample is 1000 minutes. The improved samplers are suited to accurately determine the indoor and outdoor average radon concentration under conditions of great variation in temperature and humidity

  14. Seasonal and spatial variations in Rn-222 and Rn-220 in soil gas, and implications for indoor radon levels

    International Nuclear Information System (INIS)

    Sharman, G.

    1992-01-01

    Rn-222 enters dwellings as a component of soil gas drawn from the soil by mass flow driven by the pressure difference between the house and soil beneath. In a site on Northampton Sand Ironstone (Aalenian), a preferred path of emanation (hotspot) was found. A difference of 63 Bq L -1 Rn-222 was recorded in July between this point and another 3 m away. Rn-222 in this hotspot shows 12% less variation annually than the surrounding rock. During winter, Rn-222 values within 1.6 m of the house were 44% lower than those at more than 4 m away. Rn-222 showed a 99.5% negative correlation with wind run, showing that on this soil wind pressure can significantly reduce radon in the soil at 500 mm depth. Rn-220 in soil gas correlated positively at the 99.5% level with grass and air temperatures. Rn-220 was not associated with the hotspot. (Author)

  15. Effects of air conditioning, dehumidification and natural ventilation on indoor concentrations of 222Rn and 220Rn

    International Nuclear Information System (INIS)

    Lee, Thomas K.C.; Yu, K.N.

    2000-01-01

    A bedroom was selected for detailed measurements on 220 Rn and 222 Rn concentrations and environmental parameters including CO 2 concentration, temperature and relative humidity. To simulate different sealing conditions, five conditions were artificially created in the sampling period of 25 consecutive days. It was concluded that natural ventilation is the most efficient way to lower the 222 Rn levels, while air conditioning is the next. Dehumidification provides only a marginal reduction of 222 Rn levels. The 220 Rn concentrations are not affected by natural ventilation, air conditioner or dehumidification, and were all around 10 Bq m -3 . There are no significant correlations between the 220 Rn and 222 Rn concentrations and environmental conditions such as CO 2 concentrations, temperature, relative humidity and pressure

  16. Assessment of Effective Dose Equivalent of Indoor 222Rn Daughters in Inchass

    International Nuclear Information System (INIS)

    Ali, E.M.; Taha, T.M.; Gomaa, M.A.; El-Hussein, A.M.; Ahmad, A.A.

    2000-01-01

    The dominant component of natural radiation dose for the general population comes from the radon gas 222 Rn and its short-lived decay products, Ra A ( 214 Po), Ra B ( 214 Pb), Ra C ( 214 Bi), Ra C( 214 Po) in the breathing air. The objective of the present work is to assess the affective dose equivalent of the inhalation exposure of indoor 222 Rn for occupational workers. Average indon concentrations (Bqm -3 ) were monitored in several departments in Nuclear Research Center by radon monitor. We have calculated the lung dose equivalent and the effective dose equivalent for the Egyptian workers due to inhalation exposure of an equilibrium equivalent concentrations of radon daughters which varies from 0.27 to 2.5 mSvy -1 and 0.016 to 0.152mSvy -1 respectively. The annual effective doses obtained are within the accepted range of ICRP recommendations

  17. Relation between 222Rn concentration in outdoor air and lower atmosphere

    International Nuclear Information System (INIS)

    Kataoka, Toshio; Mori, Tadashige; Yunoki, Eiji; Michihiro, Kenshuh; Sugiyama, Hirokazu; Shimizu, Mitsuo; Tsukamoto, Osamu; Sahashi, Ken.

    1991-01-01

    Using the height of the surface-based inversion layer obtained by the acoustic sounder returns and the variation of the 222 Rn concentration in the outdoor air during the presence of the surface-based inversion layer, the exhalation rate of 222 Rn is estimated to be 0.020 Bq·m -2 ·s -1 , which is observed elsewhere on land. Furthermore, the exposure rate at 1 m above the air-ground interface due to the short-lived 222 Rn daughters in the outdoor air during the presence of the surface-based inversion layer can be estimated using the height of the surface-based inversion layer and the 222 Rn concentrations in the outdoor air at the ground level before and after the onset of the surface-based inversion layer. From these treatment, it is clearly demonstrated that the monostatic acoustic sounder is useful as a supplementary method for a weather survey which forms a part of monitoring around the nuclear facilities. (author)

  18. Calibration comparative results for X - and gamma ray spectrometry with HPGe and BEGe detectors for a radon reference chamber

    International Nuclear Information System (INIS)

    Zoran, Maria; Paul, Annette; Arnold, Dirk

    2002-01-01

    Inhaled decay products of 222 Rn are the dominant components of the natural radiation exposure being responsible for about 30% of the whole human radioactive exposure. Field instruments for 222 Rn and his progeny monitoring are calibrated in 'radon climate rooms', where it is possible to vary and monitor 222 Rn and the indoor air parameters ( temperature, humidity, ventilation rate, aerosol concentration). German radon reference chamber used was developed and installed at the Physikalisch-Technische Bundesanstalt in order to serve as a metrological standard for radon and his progeny calibration of active and passive, indoor and outdoor radon monitoring devices in air climate. The basic parts of experimental setup for this γ and X -ray spectrometry analysis consists of a γ-X ray source in a lead shield/collimator, the detectors, the electronics necessary for pulse-height analysis (PHA) to obtain energy spectra. For calibrating system with 226 Ra standard sources (multienergy X ray and gamma emitters), two germanium detectors HPGe (12.5 nominal efficiency) and BEGe (22.5 nominal efficiency) were used. Germanium detectors are semiconductor diodes having a P-I-N structure in which the Intrinsic (I) region is sensitive to ionizing radiation, particularly X-rays and gamma rays. The BEGe is designed with an electrode structure that enhances low energy resolution and is fabricated from selected germanium having an impurity profile that improves charge collection (thus resolution and peak shape) at high energies which is really important in analysis of the complex spectra for uranium and finally for 226 Ra. MAESTRO MCA software and GNUPLOT program were used for spectra acquisition and spectra analysis, respectively . The main aim of this paper was to do a comparatively analysis of the detector performances for this radon chamber spectrometric chain. The calibration data analysis includes energy calibrations for both detection systems as well as comparative X and gamma

  19. Glove box chamber

    International Nuclear Information System (INIS)

    Cox, M.E.; Cox, M.E.

    1975-01-01

    An environmental chamber is described which enables an operator's hands to have direct access within the chamber without compromising a special atmosphere within such chamber. A pair of sleeves of a flexible material are sealed to the chamber around associated access apertures and project outwardly from such chamber. Each aperture is closed by a door which is openable from within the sleeve associated therewith so that upon an operator inserting his hand and arm through the sleeve, the operator can open the door to have access to the interior of the chamber. A container which is selectively separable from the remainder of the chamber is also provided to allow objects to be transferred from the chamber without such objects having to pass through the ambient atmosphere. An antechamber permitting objects to be passed directly into the chamber from the ambient atmosphere is included. (auth)

  20. Configurations and level structure of 219Rn

    International Nuclear Information System (INIS)

    Sheline, R.K.; Liang, C.F.; Paris, P.

    1998-01-01

    The level structure of 219 Rn has been studied using the alpha decay of 223 Ra and coincident gamma rays. While only modest changes are required in the level structure, and only above 342.8 keV, severe changes are required throughout the level scheme in the spin assigments. These changes allow the assignment of two sets of anomalous bands with K=5/2 ± and K=3/2 ± . The K=5/2 ± bands have configurations intermediate between the reflection asymmetric configuration and the g 9/2 shell model configuration, while the K=3/2 ± bands have configurations intermediate between the mixed reflection asymmetric configuration and the i 11/2 shell model configuration. Comparison of the systematics of 219 Rn with neighboring isotones, isobars, and isotopes shows clearly the collapse of the quadrupole-octupole-type configurations into the less degenerate shell model configurations. copyright 1998 The American Physical Society

  1. Pressurized air ionization chamber with aluminium walls for radiometric dosimetry

    International Nuclear Information System (INIS)

    Rodrigues, R.G.S.; Pela, C.A.; Netto, T.G.

    1996-01-01

    A pressurized air ionization chamber with 23 cm 3 and aluminium walls is evaluated concerning its sensitiveness in low exposure rate. Considering conventional ionization chambers, this chamber shows a better performance since the air pressure of 2500 kPa minimizes the energy dependence to less than 5% between 40 and 1.250 keV

  2. Martin Pärn Kunstihoone salongis

    Index Scriptorium Estoniae

    1999-01-01

    15. 03 Martin Pärna mööbligrupi "Martin" presentatsioon. 1998. a. pälvis M. Pärn Euroopa disainipreemia Best in the Best Rote Punkt, mida jagab Design Zentrum Nordrhein Westfalen. 1999. a. parim on M. Pärna Martela OY-le projekteeritud klapplaud. Aasta Design Team - Philipsi disaini meeskond. Äramärgitud tooted on näitusel Nordrhein Westfaleni Design Zentrumis

  3. RN students need to tell their stories.

    Science.gov (United States)

    Blecke, J; Flatt, M M

    1993-04-01

    Finally, what is it about RN students' experiences in the transition process in nursing education that makes their stories need to be told? Actually this question is asked from both the side of the RN students who are the learners and need to tell the stories, and the side of the educator/advisor who needs to have the stories told. In short, the answer to both is that these stories reveal very graphically and meaningfully what is happening in the learning and professional development processes and, simultaneously, they facilitate the progression of those processes. The RN students seem to have an innate sense about what telling their stories will do for them in relation to their learning and professional development processes. They require very little encouragement to prompt their story telling. For the educators/advisors, no other strategy is as adaptable and achieves as much in relation to facilitating the learning and development processes. For both parties, the graphic revelations in stories paint a picture of how past, present, and future blend together to form a meaningful, coherent view of a position in the world. According to Antonovsky's (1979) work on stress and coping, such a view is necessary if stress is to be resisted and health maintained.(ABSTRACT TRUNCATED AT 400 WORDS)

  4. Concentration of {sup 222}Rn in drinking water of the Zacatecas City, measured by liquid scintillation and associated dose; Concentracion de {sup 222}Rn en agua potable de la Ciudad de Zacatecas, medida por centelleo liquido y dosis asociada

    Energy Technology Data Exchange (ETDEWEB)

    Arevalo B, C. A.; Lopez del R, H.; Davila R, J. I.; Mireles G, F.; Pinedo V, J. L.; Rios M, C.; Saucedo A, S. A., E-mail: cesar_arevalob@outlook.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2017-09-15

    A study was carried out to determine the concentration of {sup 222}Rn in samples of drinking water collected from different homes in the Zacatecas city, Mexico, whose main source of supply is groundwater. The {sup 222}Rn radioactive gas is a product of the decay series of {sup 238}U and is considered one of the main sources of natural radiation, since it contributes almost half of the radiation dose that a person will receive throughout his life. The {sup 222}Rn originates in the rocks of the aquifers and dissolves in the water, which is later integrated into the distribution network of the public supply that supplies the entire population. Exposure to ionizing radiation that {sup 222}Rn and its offspring emit can damage the DNA molecule, inducing the possible appearance of cancer. Has been demonstrated by various epidemiological studies carried out in uranium mines workers in different parts of the world, that this exposure increases the incidence of lung cancer, placing {sup 222}Rn and their offspring as the second main cause of this type of cancer, after smoking habit. Using the technique of solvent extraction of {sup 222}Rn in water and liquid scintillation spectrometry, water collected from 14 different households was sampled and analyzed. The average of the measured activity of {sup 222}Rn was 2.09 Bq/L and the annual effective dose per water intake attributable to that concentration of 6.07 mSv/a. The concentration of {sup 222}Rn in water and the annual effective dose are below 11 Bq/L and 50 mSv/a, such concentrations are the maximum limits established by the Unites States Environmental Protection Agency (US EPA) and the ICRP, respectively. The concentration of {sup 222}Rn that is transferred from the water to the air inside a house was also calculated and the radiation dose that this concentration causes by inhalation, being 0.209 Bq/m{sup 3} and 1,463 μ Sv a, respectively. (Author)

  5. Effect of cell phone radiofrequency radiation on body temperature in rodents: Pilot studies of the National Toxicology Program's reverberation chamber exposure system.

    Science.gov (United States)

    Wyde, Michael E; Horn, Thomas L; Capstick, Myles H; Ladbury, John M; Koepke, Galen; Wilson, Perry F; Kissling, Grace E; Stout, Matthew D; Kuster, Niels; Melnick, Ronald L; Gauger, James; Bucher, John R; McCormick, David L

    2018-04-01

    Radiofrequency radiation (RFR) causes heating, which can lead to detrimental biological effects. To characterize the effects of RFR exposure on body temperature in relation to animal size and pregnancy, a series of short-term toxicity studies was conducted in a unique RFR exposure system. Young and old B6C3F1 mice and young, old, and pregnant Harlan Sprague-Dawley rats were exposed to Global System for Mobile Communication (GSM) or Code Division Multiple Access (CDMA) RFR (rats = 900 MHz, mice = 1,900 MHz) at specific absorption rates (SARs) up to 12 W/kg for approximately 9 h a day for 5 days. In general, fewer and less severe increases in body temperature were observed in young than in older rats. SAR-dependent increases in subcutaneous body temperatures were observed at exposures ≥6 W/kg in both modulations. Exposures of  ≥10 W/kg GSM or CDMA RFR induced excessive increases in body temperature, leading to mortality. There was also a significant increase in the number of resorptions in pregnant rats at 12 W/kg GSM RFR. In mice, only sporadic increases in body temperature were observed regardless of sex or age when exposed to GSM or CDMA RFR up to 12 W/kg. These results identified SARs at which measurable RFR-mediated thermal effects occur, and were used in the selection of exposures for subsequent toxicology and carcinogenicity studies. Bioelectromagnetics. 39:190-199, 2018. © 2018 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc. © 2018 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc.

  6. Passive Rn dose meters - measuring methods appropriate for large measurement series

    International Nuclear Information System (INIS)

    Urban, M.; Kiefer, H.

    1985-01-01

    Passive integrating measuring methods can be classified in several groups by their functioning principle, e.g. spray chambers or open chambers with nuclear trace detectors or TL detectors, open detectors, activated carbon dose meters with or without TL detectors. According to the functioning principle, only radon or radon and fission products can be detected. The lecture gives a survey of the present state of development of passive Rn dose meters. By the example of the Ra dose meter developed at Karlsruhe which was used in inquiry measurements carried out in Germany, Switzerland, the Netherlands, Belgium and Austria, etching technology, estimation of measuring uncertainties, reproducibility and fading behaviour shall be discussed. (orig./HP) [de

  7. The ventilation influence on the spatial distribution of Rn-222 and its decay products in human inhabited environments

    International Nuclear Information System (INIS)

    Munoz, S.N.M.; Hadler, J.C.; Paulo, S.R.

    1996-01-01

    For the determination of the ventilation influence (directional flux of air induced by a fan) on the spatial distribution of Rn-222 and its decay products (daughters) present in human inhabited environments, a group of experimental results were obtained by means of the fission nuclear tracks left by α-particles over adequate plastic detectors CR-39). The exposure of these detectors was done in a closed environment considering the influence of ventilation for different angles, velocities and distances from fan. The results show that a relative quantity of daughters of Rn-222 are pulled out of the environment due to the effects of ventilation and plat-out

  8. The systemic exposure to inhaled beclometasone/formoterol pMDI with valved holding chamber is independent of age and body size

    DEFF Research Database (Denmark)

    Govoni, Mirco; Piccinno, Annalisa; Lucci, Germano

    2015-01-01

    BACKGROUND: Asthma guidelines recommend prescription of inhaled corticosteroids at a reduced dosage in children compared to older patients in order to minimize the systemic exposure and risk of unwanted side effects. In children, pressurized metered dose inhalers (pMDI) are recommended in combina......BACKGROUND: Asthma guidelines recommend prescription of inhaled corticosteroids at a reduced dosage in children compared to older patients in order to minimize the systemic exposure and risk of unwanted side effects. In children, pressurized metered dose inhalers (pMDI) are recommended......-dipropionate) was evaluated over 8 h from three studies, each performed in a different age and body size group. Children (7-11 years, n = 20), adolescents (12-17 years, n = 29) and adults (≥18 years, n = 24) received a single dose of beclometasone/formoterol (children: 200 μg/24 μg, adolescents and adults: 400 μg/24 μg) via...

  9. On the 221 Rn → 221 Fr decay scheme

    International Nuclear Information System (INIS)

    Gromov, K.Ya.; Norseev, Yu.V.; Samatov, Zh.K.; Fominykh, V.I.; Chumin, V.G.; Kudrya, S.A.; Sergienko, V.A.

    2002-01-01

    The results of investigating the 221 Rnβ - - decay and the 225 Ac α-decay are compared. It is shown that 221 Fr levels at 145.9 and 393.2 keV are excited at the 221 Rn decay. Intensities and reduced probabilities of the β - - decay to the 221 Fr levels are determined. A conclusion is drawn that the parity of the 221 Rn ground state is positive

  10. Blinde børn - integration eller isolation?

    DEFF Research Database (Denmark)

    Bengtsson, Steen; Cayuelas Mateu, Nuria; Høst, Anders

    Blinde børn har i de senere årtier været integreret i den almindelige skole. Men betyder det, at de bliver bedre forberedt til et integreret liv som voksne? Det er langt fra sikkert, viser denne undersøgelse af blinde børn. Skolen sørger for, at de blinde børn har en støttelærer, så de får det he...

  11. Dual ionization chamber

    International Nuclear Information System (INIS)

    Mallory, J.; Turlej, Z.

    1981-01-01

    Dual ionization chambers are provided for use with an electronic smoke detector. The chambers are separated by electrically-conductive partition. A single radiation source extends through the partition into both chambers, ionizing the air in each. The mid-point current of the device may be balanced by adjusting the position of the source

  12. Indoor "2"2"2Rn concentration in the exhibition and storage rooms of Polish geological museums

    International Nuclear Information System (INIS)

    Długosz-Lisiecka, Magdalena; Krystek, Marcin; Raczyński, Paweł; Głuszek, Ewa; Kietlińska-Michalik, Barbara; Niechwedowicz, Mariusz

    2017-01-01

    The radon exhaled from radioactive mineral collections exhibited in five Polish geological museums may influence its total indoor concentration. Radon concentrations measured in the exhibition halls do not pose a risk for visitors or museum staff. However, air exceeding the action limit for workers (equal to 300 Bq/m"3) was noted in the storage rooms of two museums. Significant"2"2"2Rn activity concentrations equal to more than ~300 kBq/m"3were measured inside lead containers where radioactive minerals were stored. - Highlights: • In this "2"2"2Rn radionuclide measurements in 5 Polish geological museums have been done. • The review of "2"2"2Rn activity in the air in areas containing radioactive geological collections is not a routine protocol, and is not included in the national radon monitoring program. • Therefore the radiological exposure for museum staff resulting from inhalation of gaseous radon and its products has been including.

  13. Transitioning the RN to Ambulatory Care: An Investment in Orientation.

    Science.gov (United States)

    Allen, Juliet Walshe

    2016-01-01

    Registered nurses (RNs) struggle when transitioning from the inpatient setting to the outpatient clinical environment because it results in a diverse skill-set shift. The RN, considered an outpatient revenue source, experiences a decrease in peer-to-peer relationships, changes in leadership responsibilities, and changes in workgroup dynamics (supervision of unlicensed clinical personnel who function under the direction of the physician, not the RN). Ambulatory organizations find themselves implementing clinical orientation programs that may not delineate the attributes of the RN. This diminishes their value while emphasizing the unlicensed technical skill set. Creating a core RN orientation program template is paramount for the transition of the RN to the ambulatory setting. The literature reveals several areas where improving the value of the RN will ultimately enhance recruitment and retention, patient care outcomes, and leverage the RN role within any organization. Eleven 30-minute in-depth telephone interviews were conducted in addition to 4 nurse observations to explore the lived experience of the RN in ambulatory care. The findings disclosed an overarching theme of nurse isolation and offered insightful underpinnings for the nurse leader as ambulatory growth continues and nurse leaders further endorse the RN presence in the ambulatory setting.

  14. Soil as a source of indoor 220Rn

    International Nuclear Information System (INIS)

    Li, Y.; Schery, S.D.; Turk, B.

    1992-01-01

    Two suggestions for sources of indoor 220Rn (thoron) have appeared in the literature: (1) building materials and outside air, and (2) soil beneath the house. Due to the difficulty of 220Rn measurement and limited data, both suggestions lack sufficient supporting evidence. We have investigated sources of indoor 220Rn in seven occupied houses in northern New Mexico, U.S. A two-filter system was used to measure indoor 220Rn levels continuously, and 220Rn progeny were measured with single filters and specialized alpha-track detectors. The amount of 220Rn entry from soil was curtailed by cutting off soil gas flow to the indoor air with subfloor depressurization mitigation systems. Four of the houses showed significant reductions in 220Rn with mitigation systems on. The average effect for these houses was to reduce indoor 220Rn levels by 70%. The other three houses had no clear reductions but in one of these houses, the mitigation system was not effective for stopping soil gas flow. Our results provide some of the most clear evidence to date supporting soil as an important source of indoor 220Rn

  15. Contribution of (222)Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China.

    Science.gov (United States)

    Song, Gang; Wang, Xinming; Chen, Diyun; Chen, Yongheng

    2011-04-01

    This study investigates the contribution of radon ((222)Rn)-bearing water to indoor (222)Rn in thermal baths. The (222)Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM(10) and PM(2.5)) and carbon dioxide (CO(2)) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m(-3) of (222)Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which (222)Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average (222)Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor (222)Rn levels were influenced by the (222)Rn concentrations in the hot spring water and the bathing times. The average (222)Rn transfer coefficients from water to air were 6.2 × 10(-4)-4.1 × 10(-3). The 24-h average levels of CO(2) and PM(10) in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM(2.5). Radon and PM(10) levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Radiation exposure and dose to small mammals in radon-rich soils

    International Nuclear Information System (INIS)

    Macdonald, C.R.; Laverock, M.J.

    1998-01-01

    Protection of the environment from radionuclide releases requires knowledge of the normal background levels of radiation exposure in the exposed biotic community and an estimate of the detriment caused by additional exposure. This study modeled the background exposure and dose to the lungs of small burrowing mammals from 222 Rn in artificial burrows in radon-rich soils at a site in southeastern Manitoba. E-PERM chambers used to measure 222 Rn in soil showed good reproducibility of measurement, with an average coefficient of variance (CV) of about 10%. Geometric mean (GM) 222 Rn concentrations at nine randomly selected sites ranged from 5,490 Bq/m 3 (GSD = 1.57, n = 7) to 41,000 Bq/m 3 (GSD = 1.02, n = 5). Long-term monitoring of 222 Rn concentrations in artificial burrows showed large variation within and between burrows and did not show consistent variation with season, orientation of the burrow opening, or levels of 226 Ra in the soil. Annual GM concentrations in individual burrows ranged from 7,480 Bq/m 3 (GSD = 1.60) to 18,930 Bq/m 3 (GSD = 1.81) in burrows several meters apart. A grand GM of 9,990 Bq/m 3 (GSD = 1.81, n = 214) was measured over the site for the year. An exposure model was constructed for five small mammal species based on their respiration rates and the number of hours spent in the burrow, active or hibernating, exposed to soil gas 222 Rn, and the time spent out of the burrow exposed to atmospheric 222 Rn. A background dose of 0.9 mGy/a from atmospheric 222 Rn (40 Bq/m 3 ) was estimated for a large-bodied (80 kg), nonburrowing animal living on the soil surface. The highest exposures (mJ/a) in burrowing mammals occurred in those species with the highest respiration rates. Hibernation accounted for a small fraction of total annual exposure ( 22R n concentrations from the field studies and an equilibrium factor (F) of 0.5, doses to lung ranged from 90 mGy/a in the badger to 700 mGy/a in the pocket gopher. These doses closely correspond to those

  17. Double chamber ion source

    International Nuclear Information System (INIS)

    Uman, M.F.; Winnard, J.R.; Winters, H.F.

    1978-01-01

    The ion source is comprised of two discharge chambers one of which is provided with a filament and an aperture leading into the other chamber which in turn has an extraction orifice. A low voltage arc discharge is operated in an inert gas atmosphere in the filament chamber while an arc of higher voltage is operated in the second ionization chamber which contains a vapor which will give the desired dopant ion species. The entire source is immersed in an axial magnetic field parallel to a line connecting the filament, the aperture between the two chambers and the extraction orifice. (author)

  18. Measurement uncertainties of long-term 222Rn averages at environmental levels using alpha track detectors

    International Nuclear Information System (INIS)

    Nelson, R.A.

    1987-01-01

    More than 250 replicate measurements of outdoor Rn concentration integrated over quarterly periods were made to estimate the random component of the measurement uncertainty of Track Etch detectors (type F) under outdoor conditions. The measurements were performed around three U mill tailings piles to provide a range of environmental concentrations. The measurement uncertainty was typically greater than could be accounted for by Poisson counting statistics. Average coefficients of variation of the order of 20% for all measured concentrations were found. It is concluded that alpha track detectors can be successfully used to determine annual average outdoor Rn concentrations through the use of careful quality control procedures. These include rapid deployment and collection of detectors to minimize unintended Rn exposure, careful packaging and shipping to and from the manufacturer, use of direct sunlight shields for all detectors and careful and secure mounting of all detectors in as similar a manner as possible. The use of multiple (at least duplicate) detectors at each monitoring location and an exposure period of no less than one quarter are suggested

  19. Longitudinal changes of nerve conduction velocity, distal motor latency, compound motor action potential duration, and skin temperature during prolonged exposure to cold in a climate chamber.

    Science.gov (United States)

    Maetzler, Walter; Klenk, Jochen; Becker, Clemens; Zscheile, Julia; Gabor, Kai-Steffen; Lindemann, Ulrich

    2012-09-01

    Changes of nerve conduction velocity (NCV), distal motor latency (DML), compound motor action potential (CMAP) duration, and skin temperature with regard to cold have been investigated by use of ice packs or cold water baths, but not after cooling of environmental temperature which has higher ecological validity. The aim of this study was to investigate these parameters during cooled room temperature. NCV, DML, and CMAP duration of the common fibular nerve, and skin temperature were measured in 20 healthy young females during exposure to 15°C room temperature, coming from 25°C room. We found that NCV decreased and DML increased linearly during 45 min observation time, in contrast to CMAP duration and skin temperature which changes followed an exponential curve. To the best of our knowledge, this is the first study investigating changes of these parameters during exposure to environmental cold. The results may pilot some new hypotheses and studies on physiological and pathological changes of the peripheral nervous system and skin to environmental cold, e.g., in elderly with peripheral neuropathies.

  20. Improved automated analysis of radon (222Rn) and thoron (220Rn) in natural waters.

    Science.gov (United States)

    Dimova, Natasha; Burnett, William C; Lane-Smith, Derek

    2009-11-15

    Natural radon ((222)Rn) and thoron ((220)Rn) can be used as tracers of various chemical and physical processes in the environment. We present here results from an extended series of laboratory experiments intended to improve the automated analysis of (222)Rn and (220)Rn in water using a modified RAD AQUA (Durridge Inc.) system. Previous experience with similar equipment showed that it takes about 30-40 min for the system to equilibrate to radon-in-water concentration increases and even longer for the response to return to baseline after a sharp spike. While the original water/gas exchanger setup was built only for radon-in-water measurement, our goal here is to provide an automated system capable of high resolution and good sensitivity for both radon- and thoron-in-water detections. We found that faster water flow rates substantially improved the response for both isotopes while thoron is detected most efficiently at airflow rates of 3 L/min. Our results show that the optimum conditions for fastest response and sensitivity for both isotopes are at water flow rates up to 17 L/min and an airflow rate of 3 L/min through the detector. Applications for such measurements include prospecting for naturally occurring radioactive material (NORM) in pipelines and locating points of groundwater/surface water interaction.

  1. An assessment method of dose equivalent due to indoor 220Rn progeny by using 220Rn concentration measured at a 20 cm distance from wall

    International Nuclear Information System (INIS)

    Iida, T.; Ikebe, Y.; Okamoto, K.; Guo, Q.; Yamasaki, T.

    1996-01-01

    A pair of passive cup monitors with a different air exchange openings was developed for measuring simultaneously 222 Rn and 220 Rn concentrations. Indoor 220 Rn concentrations were very high in traditional Japanese dwellings with soil walls. The 220 Rn concentration decreases exponentially with the distance from wall. The effective diffusion coefficient of 220 Rn in dwelling and the exhalation rate of 220 Rn from wall were evaluated from the distribution of the 220 Rn concentrations. Then, indoor 220 Rn progeny concentration could be estimated from the 220 Rn concentration at a 20 cm distance from wall. From the results of the surveys. the average annual effective dose equivalent due to 220 Rn progeny was expected to be 0.67 mSv/year in the traditional Japanese dwellings. (author)

  2. rnävaaran koiraurheilukeskuksen markkinatutkimus

    OpenAIRE

    Primetta, Jaana

    2017-01-01

    Opinnäytetyön aiheena oli Pärnävaaran koiraurheilukeskuksen markkinatutkimus, jonka tavoitteena oli saada tietoa pohjoiskarjalaisten koiraharrastajien aktiivisuudesta ja kiinnostuksesta käyttää maakunnan alueella sijaitsevia koiraharrastushalleja. Lisäksi haluttiin selvittää, mitkä tekijät vaikuttavat harrastajien päätöksiin harrastustilaa valittaessa ja mitä toiveita ja odotuksia harrastajilla on koiraharrastushalleja kohtaan. Opinnäytetyössä toteutettiin kaksi erillistä kvantitati...

  3. Extremal RN/CFT in both hands revisited

    International Nuclear Information System (INIS)

    Kuo, En-Jui; Yang, Yi

    2016-01-01

    We study RN/CFT correspondence for four dimensional extremal Reissner–Nordstrom black hole. We uplift the 4d RN black hole to a 5d rotating black hole and make a geometric regularization of the 5d space–time. Both hands central charges are obtained correctly at the same time by Brown–Henneaux technique.

  4. Factors affecting radon removal from Rn-222 enriched water

    International Nuclear Information System (INIS)

    Abulfaraj, W.H.; Mamoon, A.

    1994-01-01

    Continued use of potable well water that has elevated levels of Rn-222 is harmful to human health. activated carbon, aeration and heating can remove radon from treated water. Water artificially enriched with Rn-222 using a pitchblende source was studied in a laboratory scale model under controlled conditions. (author), 3 figs., 3 refs

  5. Measurement of 222Rn flux, 222Rn emanation and 226Ra concentration from injection well pipe scale

    International Nuclear Information System (INIS)

    Rood, A.S.; Kendrick, D.T.

    1996-01-01

    The presence of Naturally Occurring Radioactive Material (NORM) has been recognized since the early 1930s in petroleum reservoirs and in oil and gas production and processing facilities. NORM was typically observed in barite scale that accumulated on the interior of oil production tubing and in storage tank and heater-treater separation sludge. Recent concern has been expressed over the health impacts from the uncontrolled release of NORM to the public. There are several potential exposure pathways to humans from oil-field NORM. Among these is inhalation of radon gas and its daughter products. For this exposure pathway to be of any significance, radon must first be released from the NORM matrix and diffuse in free air. The radon emanation fraction refers to the fraction of radon atoms produced by the decay of radium, that migrate from the bulk material as free gaseous atoms. The purpose of this investigation was to characterize the radon release rates from NORM-scale contaminated production tubing being stored above ground, characterize the radon emanation fraction of the bulk scale material when removed from the tubing, and characterize the radium concentrations of the scale. Accurate characterization of 222 Rn emanation fractions from pipe scale may dictate the type of disposal options available for this waste. Characterization of radon release from stored pipes will assist in determining if controls are needed for workers or members of the public downwind from the source. Due to the sensitive nature of this data, the location of this facility is not disclosed

  6. A long range transport model of Rn-222

    International Nuclear Information System (INIS)

    Ikebe, Y.; Kojima, S.; Shimo, M.

    1993-01-01

    In this report, we propose an analytical treatment about temporal variation of 222 Rn concentration in the atmosphere with an aim to clarify origin and transport of 222 Rn. Based on the results of numerical simulation of radon, we separate the 222 Re concentration measured at Nagoya into the following two components : (1) 222 Rn atom originated near from the measuring site, which is denoted by 'diurnal variation component'. From numerical simulation of radon, it has been shown that the measured diurnal variation can be explained by this component. (2) 222 Rn atoms originated far from the measuring site (including Chinese Continent), which is denoted by 'background component'. For this component, we propose here a one layer transport model using air mass trajectory technique. By this model we can explain the temporal variation of background component and seasonal variation of 222 Rn at Nagoya. (3 figs.)

  7. Transforming RN education: clinical learning and clinical knowledge development.

    Science.gov (United States)

    Benner, P

    1993-04-01

    Transforming RN education has the potential for transforming clinical teaching and learning for all students. The returning RN student offers possibilities for clinical learning that the generic student does not have, but this should not cause us to limit the returning RN student to the generic level. Where possible innovative programs should be developed to move the RN student from baccalaureate level to the Master's level. As educators, we should take the opportunity to increase the numbers of nurses who are educationally prepared to move into advanced levels of practice. The returning RN student offers a rich human resource for the profession, and a rich resource for improving our clinical teaching as well as our practice.

  8. Measurement of 222Rn in soil concentrations in interstitial air

    International Nuclear Information System (INIS)

    Duenas, C.; Fernandez, M.C.; Carretero, J.; Liger, E.

    1996-01-01

    Measurements of 222 Rn soil concentrations were made by inserting stainless-steel sampling tubes into the soil. The samples of the soil interstitial air were taken in to pre-evacuated 1 L glass flasks. The glass flasks are cylindrical and coated with a film of ZnS(Ag). 222 Rn was measured by counting the alpha particles emitted by 222 Rn and its daughter products, 218 Po and 214 Bi, when they reached radioactive equilibrium. Measurements of 222 Rn gas concentrations in the soil air interstices by the method at different depths were used to calculate the diffusion coefficient of the 222 Rn in the soil air. This study has been carried out for diverse soils. (Author)

  9. Streamer chamber: pion decay

    CERN Multimedia

    1992-01-01

    The real particles produced in the decay of a positive pion can be seen in this image from a streamer chamber. Streamer chambers consist of a gas chamber through which a strong pulsed electric field is passed, creating sparks as a charged particle passes through it. A magnetic field is added to cause the decay products to follow curved paths so that their charge and momentum can be measured.

  10. Prototype multiwire proportional chamber

    CERN Multimedia

    1975-01-01

    Chambers of this type were initially developed within the Alpha project (finally not approved). They were designed such to minimize the radiation length with a view to a mass spectrometer of high resolution meant to replace the Omega detector. The chambers were clearly forerunners for the (drift) chambers later built for R606 with the novel technique of crimping the wires. See also photo 7510039X.

  11. Electromagnetic reverberation chambers

    CERN Document Server

    Besnier, Philippe

    2013-01-01

    Dedicated to a complete presentation on all aspects of reverberation chambers, this book provides the physical principles behind these test systems in a very progressive manner. The detailed panorama of parameters governing the operation of electromagnetic reverberation chambers details various applications such as radiated immunity, emissivity, and shielding efficiency experiments.In addition, the reader is provided with the elements of electromagnetic theory and statistics required to take full advantage of the basic operational rules of reverberation chambers, including calibration proc

  12. DORIOT CLIMATIC CHAMBERS

    Data.gov (United States)

    Federal Laboratory Consortium — The Doriot Climatic Chambers reproduce environmental conditions occurring anywhere around the world. They provide an invaluable service by significantly reducing the...

  13. Gas microstrip chambers

    International Nuclear Information System (INIS)

    McIntyre, P.M.; Barasch, E.F.; Bowcock, T.J.V.; Demroff, H.P.; Elliott, S.M.; Howe, M.R.; Lee, B.; Mazumdar, T.K.; Pang, Y.; Smith, D.D.; Wahl, J.; Wu, Y.; Yue, W.K.; Gaedke, R.M.; Vanstraelen, G.

    1992-01-01

    The gas microstrip chamber has been developed from concept to experimental system during the past three years. A pattern of anode and grid lines are microfabricated onto a dielectric substrate and configured as a high-resolution MWPC. Four recent developments are described: Suitable plastic substrates and lithography techniques for large-area chambers; non-planar silicon-based chambers for 20 μm resolution; integrated on-board synchronous front-end electronics and data buffering; and a porous silicon active cathode for enhanced efficiency and time response. The microstrip chamber appears to be a promising technology for applications in microvertex, tracking spectrometer, muon spectrometer, and transition radiation detection. (orig.)

  14. An electrodeless drift chamber

    International Nuclear Information System (INIS)

    Allison, J.; Barlow, R.J.; Bowdery, C.K.; Duerdoth, I.; Rowe, P.G.

    1982-01-01

    We describe a chamber in which the drift field is controlled by the deposition of electrostatic charge on an insulating surface. The chamber operates with good efficiency and precision for observed drift distances of up to 45 cm, promises to be extremely robust and adaptable and offers a very cheap way of making particle detectors. (orig.)

  15. High resolution drift chambers

    International Nuclear Information System (INIS)

    Va'vra, J.

    1985-07-01

    High precision drift chambers capable of achieving less than or equal to 50 μm resolutions are discussed. In particular, we compare so called cool and hot gases, various charge collection geometries, several timing techniques and we also discuss some systematic problems. We also present what we would consider an ''ultimate'' design of the vertex chamber. 50 refs., 36 figs., 6 tabs

  16. Plastic flashtube chambers

    International Nuclear Information System (INIS)

    Frisken, W.R.

    1977-01-01

    A brief discussion is given of the use and operation of plastic flashtube chambers. Gas leaks, electric pulsing, the glow discharge, and readout methods are considered. Three distinct problems with high rate applications deal with resolving time, dead time, and polarization/neutralization of the chamber

  17. Climatic chamber ergometer

    CSIR Research Space (South Africa)

    Atkins, AR

    1968-01-01

    Full Text Available The design and calibration of an ergometer for exercising subjects during calorimetric studies in the climate chamber, are described. The ergometer is built into the climatic chamber and forms an integral part of the whole instrumentation system foe...

  18. BEBC bubble chamber

    CERN Multimedia

    CERN PhotoLab

    1972-01-01

    Looking up into the interior of BEBC bubble chamber from the expansion cylinder. At the top of the chamber two fish-eye lenses are installed and three other fish-eye ports are blanked off. In the centre is a heat exchanger.

  19. The Mobile Chamber

    Science.gov (United States)

    Scharfstein, Gregory; Cox, Russell

    2012-01-01

    A document discusses a simulation chamber that represents a shift from the thermal-vacuum chamber stereotype. This innovation, currently in development, combines the capabilities of space simulation chambers, the user-friendliness of modern-day electronics, and the modularity of plug-and-play computing. The Mobile Chamber is a customized test chamber that can be deployed with great ease, and is capable of bringing payloads at temperatures down to 20 K, in high vacuum, and with the desired metrology instruments integrated to the systems control. Flexure plans to lease Mobile Chambers, making them affordable for smaller budgets and available to a larger customer base. A key feature of this design will be an Apple iPad-like user interface that allows someone with minimal training to control the environment inside the chamber, and to simulate the required extreme environments. The feedback of thermal, pressure, and other measurements is delivered in a 3D CAD model of the chamber's payload and support hardware. This GUI will provide the user with a better understanding of the payload than any existing thermal-vacuum system.

  20. DELPHI time projection chamber

    CERN Multimedia

    1989-01-01

    The time projection chamber is inserted inside the central detector of the DELPHI experiment. Gas is ionised in the chamber as a charged particle passes through, producing an electric signal from which the path of the particle can be found. DELPHI, which ran from 1989 to 2000 on the LEP accelerator, was primarily concerned with particle identification.

  1. Ontologies in a project by Jørn Utzon

    DEFF Research Database (Denmark)

    Jørgensen, Lars Botin

    2003-01-01

    The paper has an overall theoretical and philosophical view on the actual topic: the architecture of Jørn Utzon, whereas Utzon himself often has stated that theories and hermeneutic approaches does not interest him at all. It is the aim of this paper to inscribe Jørn Utzon in a theoretical...... tradition where nature and the real is in the core of everything and furthermore to throw a light on the paradoxical non-modern and non-Cartesian aspect of the architectural practice of Jørn Utzon....

  2. Measurement of 222Rn, 220Rn and their decay products in high background radiation area in Yangjiang

    International Nuclear Information System (INIS)

    Yuan Yongling

    2000-01-01

    The investigators have measured concentrations of Rn-222, rn-220 and their decay products in high background radiation area (HBRA) and the neighboring control area (CA), as well as the equilibrium factor F for Rn-222. The average concentrations of Rn-222 in the air indoors and outdoors in the HBRA are 42.6 and 17.3 Bq/m 3 respectively, and CA, 13.2 and 11.7 Bq/m 3 , respectively. The average α-potential energy concentrations for daughters of Rn-222 indoors and outdoors in HBRA are 0.109 and 0.051 μJ/m 3 , CA, 0.045 and 0.041 μJ/m 3 , respectively. The average α-potential energy values for daughters of Rn-220 indoor and outdoor in HBRA are 0.249 and 0.053 μJ/m 3 , CA, 0.051 and 0.025 μJ/m 3 , respectively. With regard to equilibrium factor F for Rn-222, the authors have also measured 52 points of 10 hamlets in HBRA (indoor 31, outdoor 21), 9 points of 2 hamlets in CA (indoor 5, outdoor 4), respectively. These figures are 0.46, 0.53, 0.62 and 0.64, respectively

  3. Estimation of 222Rn flux and its effect on the atmospheric 222Rn concentration at Hachijo-jima Island, Japan

    International Nuclear Information System (INIS)

    Ohkura, Takehisa; Yamazawa, Hiromi; Moriizumi, Jun; Hirao, Shigekazu; Iida, Takao

    2010-01-01

    222 Rn fluxes from the ground surface and 226 Ra contents in soil were measured on Hachijo-jima Island, which is a solitary island in the Pacific Ocean located about 200 km to the south of the main island of Japan, to evaluate fractional contributions of the locally exhaled 222 Rn and the long-range transported one to the surface air concentration measured on this island. Averages of 222 Rn flux and 226 Ra content in dry soil were evaluated to be 0.9±0.4 mBq m -2 s -1 and 6.8±0.2 Bq kg -1 , respectively. These are considerably smaller than the respective values of 9.7±0.8 mBq m -2 s -1 and 23.2±0.4 Bq kg -1 measured at Nagoya as a reference. The lower value of the 226 Ra content and the even lower 222 Rn flux on this island can be attributed to the basaltic geology and the soil's coarse texture moisture, respectively. A simple model calculation assuming a typical nocturnal condition showed that the measured 222 Rn flux would cause only a small increase in the surface air concentration by 0.035 to 0.072 Bq m -3 (relative contribution of 1 to 12%) in addition to the long-range transported 222 Rn under a typical nocturnal condition. The contribution of the local flux would be smaller than that under nocturnal condition. This local 222 Rn component is negligible as compared with the concentration of the long-range transported 222 Rn (0.6 to 3.6 Bq m -3 ). It is, therefore, concluded that Hachijo-jima Island is suitable for measuring the long-range transported atmospheric 222 Rn in East Asia region. (author)

  4. Study of 222Rn emanation levels present in naturally occurring radioactive materials - NORM

    International Nuclear Information System (INIS)

    Miranda, Marcia Valeria F.E. Sa; Crispim, Verginia Reis; Lima, Clara Teresa S.

    2009-01-01

    The presence of Naturally Occurring Radioactive Material (NORM), contaminating oil and gas installations, is usual in the petroleum industry, and can be severe enough to expose the workers to elevated levels of radiation. The segregation of contaminated residues although necessary, is still a problem without a satisfactory solution. Currently, the most practical and economic option for discarding this material is to stock it in areas of the installation with controlled access. Certain equipment used in the petroleum industry has scale and sludge that could be associated to important levels of radioactivity. Typically, the scales are mixtures of carbonate and sulphate minerals, such as barite (BaSO 4 ), that easily incorporate 226 Ra and 228 Ra in their structures. The objective of this work was to measure the emanations of the radon present in NORM samples, via diffusion chambers containing a nuclear track detector (CR-39). The images of α particle tracks emanated by 222 Rn registered on CR-39 were observed with a Nikon E400 optic microscope and captured by a Nikon Coolpix digital camera and then stored in a database, to later count the tracks using the computational program, Image Pro plus. Since the number of those tracks resulted proportional to the emanation rate of 222 Rn this methodology allowed the comparison of contamination levels in analyzed samples. (author)

  5. Study of the emanation levels of 222Rn present in Naturally Occurring Radioactive Materials - NORM

    International Nuclear Information System (INIS)

    Miranda, Marcia Valeria de Fatima da Encarnacao Sa

    2009-01-01

    The presence of Naturally Occurring Radioactive Material (NORM), contaminating oil and gas facilities, is a common fact in the petroleum industry, and can be severe enough to expose the workers to elevated levels of radiation. Thus, contaminated residues need to be segregated but, this is still a problem without a satisfactory solution. Currently, the most practical and economic option for discarding this material is to stock it in areas of the facility whose access is controlled. Certain equipment used in the petroleum industry has scale and sludge that could be associated to important levels of radioactivity. Typically, the scale is a mixture of carbonate and sulphate minerals, such as barite (BaSO 4 ), that easily incorporates 226 Ra and 228 Ra in its structures. The objective of this work was to measure the emanations of the radon present in these NORM samples, via diffusion chambers containing a nuclear track detector (CR-39). The images of particle alpha tracks emanated by 222 Rn registered on CR-39 were observed with a Nikon E400 optic microscope and captured by a Nikon Coolpix digital camera and then stored in a database, to later count the tracks using the computational program, Image Pro plus. Being that the emanation rate of 222 Rn was proportional to the number of these tracks the methodology permitted the comparison of contamination levels of the analyzed samples. (author)

  6. Surface deposition of 222Rn decay products with and without enhanced air motion

    International Nuclear Information System (INIS)

    Rudnick, S.N.; Maher, E.F.

    1986-01-01

    The effectiveness of fan-induced air motion in reducing airborne activities of short-lived 222 Rn decay products was evaluated in a 78.5-m3 chamber. Observed reductions were as high as 50% for 218Po (RaA), 79% for 214 Pb (RaB), and 86% for 214 Bi (RaC). Activity measurements of these nuclides on chamber and fan surfaces, along with airborne activities, were used to calculate material balances. Greater than about 90% of deposited activity was found on chamber surfaces, although areal activity densities were higher on fan surfaces. Deposition velocities for decay products not attached to particles were 2.3 mm s-1 when no fans were in operation and 9.2 to 13 mm s-1 when fans were used. Mean boundary layer thicknesses for unattached decay products were estimated to be about four times the recoil distance of a 214 Pb atom when no fans were used and about equal to the recoil distance when fans were used

  7. A digital reader for condenser ionization chambers

    International Nuclear Information System (INIS)

    Stuermer, K.

    1978-01-01

    A reader for condenser chambers is described which has a completely automatic reading/charging operation, a modern digital readout presentation, and two full decades of exposure readout for each dosimeter type. The calibration and operation of the instrument are given

  8. OPAL Jet Chamber Prototype

    CERN Multimedia

    OPAL was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. OPAL's central tracking system consists of (in order of increasing radius) a silicon microvertex detector, a vertex detector, a jet chamber, and z-chambers. All the tracking detectors work by observing the ionization of atoms by charged particles passing by: when the atoms are ionized, electrons are knocked out of their atomic orbitals, and are then able to move freely in the detector. These ionization electrons are detected in the dirfferent parts of the tracking system. This piece is a prototype of the jet chambers

  9. PS wire chamber

    CERN Multimedia

    1970-01-01

    A wire chamber used at CERN's Proton Synchrotron accelerator in the 1970s. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  10. Limited Data Problems for the Generalized Radon Transform in Rn

    DEFF Research Database (Denmark)

    Frikel, Jürgen; Quinto, Eric Todd

    2016-01-01

    We consider the generalized Radon transform (defined in terms of smooth weight functions) on hyperplanes in Rn. We analyze general filtered backprojection type reconstruction methods for limited data with filters given by general pseudodifferential operators. We provide microlocal characterizations...

  11. PAH partitioning in a toxicity exposure chamber

    International Nuclear Information System (INIS)

    Sterling, M.C. Jr.; Autenrieth, R.L.; Bonner, J.S.; Page, C.A.; Fuller, C.B.; Ernest, A.N.S.

    2003-01-01

    The hypothesis that observed petroleum aromatic hydrocarbon (PAH) concentrations in an aqueous system are equal to the sum of the organic phase and the soluble phase molar concentrations was examined. Raoult's law was used to estimate the soluble phase molar concentrations. The organic phase concentrations were proportional to the PAH mole fraction in the oil. The experiment involved initially loading a batch laboratory mixing vessel with a scalable mixing energy at various oil layer thicknesses corresponding to oil surface loadings. The vessel was then agitated at a constant mean shear rate. Periodical total petroleum hydrocarbon (TPH) samples were taken in order to estimate the entrainment rate as a function of initial oil layer thickness. In-situ measurements of TPH concentrations were performed with the use of a laser scattering instrument while ex-situ measurements were effected using gravimetric analysis. Additional samples were analyzed for PAH concentration at a steady state TPH concentration using gas chromatograph/mass spectrometer (GC/MS) analysis. The results obtained were in agreement with a first order kinetic model (TPH concentrations increased over time). It was noted that in general, the first order rate constant and steady state concentration increased with increased oil loading and increased mean shear rates. There was good correlation between the measurements and the concentrations predicted using the hypothesized model. 8 refs., 3 tabs., 2 figs

  12. Thoron (220Rn) in the indoor environment and work places

    Science.gov (United States)

    Ramachandran, T. V.; Sahoo, B. K.

    2009-08-01

    Ever since studies on uranium miners established the presence of a positive risk coefficient for the occurrence of lung cancer in miners exposed to elevated levels of 222Rn and its progeny, there was a great upsurge of interest in the measurement of 222Rn in the environment. Subsequently, considerable data is being generated on the levels of 222Rn in the environment across the worlds and is being periodically reported by UNSCEAR reports. In contrast to this, data pertaining to 220Rn in indoors and workplace environment is scaree due to the genral perception that its levels are negligible due to its shorter half life, and subsequently its contribution to the total inhalation dose is ignored, in the presence of other significant sources of natural radiation. This may not be true. Globally many locations have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products like radon (222Rn), and thoron (220Rn) in the environment. Of late, technologically enhanced naturally occurring radioactive material has also contributed to the burden of background radiation. It is estimated that inhalation of 222Rn, 220Rn and their short lived progenies contribute more than 54% of the total natural background radiation dose received by the general population. 220Rn problem exists in industries which use thorium nitrate. Including India, lamps using thoriated gas mantles are still being used for indoor and outdoor lighting and by hawkers in rural as well as urban areas. Considering the fact that large amount of thorium nitrate is being handled by these industries, contribution to the inhalation dose of workers from 220Rn gas emanated and build up of the progeny in ambient air may also be quite significant. In this paper current status of 220Rn levels in the indoor environment and workplaces as well as in other industries where large amount of 232Th is being handled is being summarized. Methods of measurement and

  13. Thoron (220Rn) in the indoor environment and work places

    International Nuclear Information System (INIS)

    Ramchandran, T.V.; Sahoo, B.K.

    2009-01-01

    Ever since studies on uranium miners established the presence of a positive risk coefficient for the occurrence of lung cancer in miners exposed to elevated levels of 222 Rn and its progeny, there was a great upsurge of interest in the measurement of 222 Rn in the environment. Subsequently, considerable data is being generated on the levels of 222 Rn in the environment across the worlds and is being periodically reported by UNSCEAR reports. In contrast to this, data pertaining to 220 Rn in indoors and workplace environment is scaree due to the general perception that its levels are negligible due to its shorter half life, and subsequently its contribution to the total inhalation dose is ignored, in the presence of other significant sources of natural radiation. This may not be true. Globally many locations have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products like radon ( 222 Rn), and thoron ( 220 Rn) in the environment. Of late, technologically enhanced naturally occurring radioactive material has also contributed to the burden of background radiation. It is estimated that inhalation of 222 Rn, 220 Rn and their short lived progenies contribute more than 54% of the total natural background radiation dose received by the general population. 220 Rn problem exists in industries which use thorium nitrate. Including India, lamps using thoriated gas mantles are still being used for indoor and outdoor lighting and by hawkers in rural as well as urban areas. Considering the fact that large amount of thorium nitrate is being handled by these industries, contribution to the inhalation dose of workers from 220 Rn gas emanated and build up of the progeny in ambient air may also be quite significant. In this paper current status of 220 Rn levels in the indoor environment and workplaces as well as in other industries where large amount of 232 Th is being handled is being summarized. Methods of

  14. Margus Pärn : turuliidri koht on Maximale jõukohane 4-5 aastaga / Margus Pärn ; interv. Viljar Rääsk

    Index Scriptorium Estoniae

    Pärn, Margus

    2008-01-01

    Leedu jaekaubandusketi Maxima Eesti juht Margus Pärn vastab küsimustele, mis puudutavad Eesti jaekaubandusturgu ja Maxima positsiooni selles, ettevõtte laienemist ning turuliidri rolli saavutamise võimalust. Lisa: Margus Pärn. Tabel: Maxima

  15. rn Utzon’s Maritime Origins

    DEFF Research Database (Denmark)

    Jaeger, Thomas Arvid

    2014-01-01

    Article about Jørn Utzons and the influence on his architecture comming from his early years with sailing, and learning about boat construction and the design principles from his father - the yacht designer Aage Utzon.......Article about Jørn Utzons and the influence on his architecture comming from his early years with sailing, and learning about boat construction and the design principles from his father - the yacht designer Aage Utzon....

  16. Acoustic-Levitation Chamber

    Science.gov (United States)

    Barmatz, M. B.; Granett, D.; Lee, M. C.

    1984-01-01

    Uncontaminated environments for highly-pure material processing provided within completely sealed levitation chamber that suspends particles by acoustic excitation. Technique ideally suited for material processing in low gravity environment of space.

  17. Optical spark chamber

    CERN Multimedia

    CERN PhotoLab

    1971-01-01

    An optical spark chamber developed for use in the Omega spectrometer. On the left the supporting frame is exceptionally thin to allow low momentum particles to escape and be detected outside the magnetic field.

  18. Vacuum chamber 'bicone'

    CERN Multimedia

    1977-01-01

    This chamber is now in the National Museum of History and Technology, Smithsonian Institution, Washington, DC, USA, where it was exposed in an exhibit on the History of High Energy Accelerators (1977).

  19. Miniature ionization chamber

    International Nuclear Information System (INIS)

    Alexeev, V.I.; Emelyanov, I.Y.; Ivanov, V.M.; Konstantinov, L.V.; Lysikov, B.V.; Postnikov, V.V.; Rybakov, J.V.

    1976-01-01

    A miniature ionization chamber having a gas-filled housing which accommodates a guard electrode made in the form of a hollow perforated cylinder is described. The cylinder is electrically associated with the intermediate coaxial conductor of a triaxial cable used as the lead-in of the ionization chamber. The gas-filled housing of the ionization chamber also accommodates a collecting electrode shaped as a rod electrically connected to the center conductor of the cable and to tubular members. The rod is disposed internally of the guard electrode and is electrically connected, by means of jumpers passing through the holes in the guard electrode, to the tubular members. The tubular members embrace the guard electrode and are spaced a certain distance apart along its entire length. Arranged intermediate of these tubular members are spacers secured to the guard electrode and fixing the collecting electrode throughout its length with respect to the housing of the ionization chamber

  20. Reference ionization chamber

    International Nuclear Information System (INIS)

    Golnik, N.; Zielczynski, M.

    1999-01-01

    The paper presents the design of ionization chamber devoted for the determination of the absolute value of the absorbed dose in tissue-equivalent material. The special attention was paid to ensure that the volume of the active gas cavity was constant and well known. A specific property of the chamber design is that the voltage insulators are 'invisible' from any point of the active volume. Such configuration ensures a very good time stability of the electrical field and defines the active volume. The active volume of the chamber was determined with accuracy of 0.3%. This resulted in accuracy of 0.8% in determination of the absorbed dose in the layer of material adherent to the gas cavity. The chamber was applied for calibration purposes at radiotherapy facility in Joint Institute for Nuclear Research in Dubna (Russia) and in the calibration laboratory of the Institute of Atomic Energy in Swierk. (author)

  1. Gridded ionization chamber

    International Nuclear Information System (INIS)

    Houston, J.M.

    1977-01-01

    An improved ionization chamber type x-ray detector comprises a heavy gas at high pressure disposed between an anode and a cathode. An open grid structure is disposed adjacent the anode and is maintained at a voltsge intermediate between the cathode and anode potentials. The electric field which is produced by positive ions drifting toward the cathode is thus shielded from the anode. Current measuring circuits connected to the anode are, therefore, responsive only to electron current flow within the chamber and the recovery time of the chamber is shortened. The grid structure also serves to shield the anode from electrical currents which might otherwise be induced by mechanical vibrations in the ionization chamber structure

  2. ALICE Time Projection Chamber

    CERN Multimedia

    Lippmann, C

    2013-01-01

    The Time Projection Chamber (TPC) is the main device in the ALICE 'central barrel' for the tracking and identification (PID) of charged particles. It has to cope with unprecedented densities of charges particles.

  3. Gridded Ionization Chamber

    International Nuclear Information System (INIS)

    Manero Amoros, F.

    1962-01-01

    In the present paper the working principles of a gridded ionization chamber are given, and all the different factors that determine its resolution power are analyzed in detail. One of these devices, built in the Physics Division of the JEN and designed specially for use in measurements of alpha spectroscopy, is described. finally the main applications, in which the chamber can be used, are shown. (Author) 17 refs

  4. Bubble chamber: antiproton annihilation

    CERN Multimedia

    1971-01-01

    These images show real particle tracks from the annihilation of an antiproton in the 80 cm Saclay liquid hydrogen bubble chamber. A negative kaon and a neutral kaon are produced in this process, as well as a positive pion. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that had been heated to boiling point.

  5. Sleeve reaction chamber system

    Science.gov (United States)

    Northrup, M Allen [Berkeley, CA; Beeman, Barton V [San Mateo, CA; Benett, William J [Livermore, CA; Hadley, Dean R [Manteca, CA; Landre, Phoebe [Livermore, CA; Lehew, Stacy L [Livermore, CA; Krulevitch, Peter A [Pleasanton, CA

    2009-08-25

    A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.

  6. Contribution of {sup 222}Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China

    Energy Technology Data Exchange (ETDEWEB)

    Song Gang, E-mail: songg2005@126.co [School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006 (China); Wang Xinming [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen Diyun; Chen Yongheng [School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006 (China)

    2011-04-15

    This study investigates the contribution of radon ({sup 222}Rn)-bearing water to indoor {sup 222}Rn in thermal baths. The {sup 222}Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM{sub 10} and PM{sub 2.5}) and carbon dioxide (CO{sub 2}) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m{sup -3} of {sup 222}Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which {sup 222}Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average {sup 222}Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor {sup 222}Rn levels were influenced by the {sup 222}Rn concentrations in the hot spring water and the bathing times. The average {sup 222}Rn transfer coefficients from water to air were 6.2 x 10{sup -4}-4.1 x 10{sup -3}. The 24-h average levels of CO{sub 2} and PM{sub 10} in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM{sub 2.5}. Radon and PM{sub 10} levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants. - Highlights: {yields} {sup 222}Rn-bearing water is the main contributor to indoor radon in hot spring hotel. {yields} The PM{sub 2.5} and CO{sub 2} are also the main indoor pollutants in the hotel rooms. {yields} Higher radon and PM levels might have significant negative health effects to human. {yields} The radon transfer coefficients are consistent with the published data.

  7. Contribution of 222Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China

    International Nuclear Information System (INIS)

    Song Gang; Wang Xinming; Chen Diyun; Chen Yongheng

    2011-01-01

    This study investigates the contribution of radon ( 222 Rn)-bearing water to indoor 222 Rn in thermal baths. The 222 Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM 10 and PM 2.5 ) and carbon dioxide (CO 2 ) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m -3 of 222 Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which 222 Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average 222 Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor 222 Rn levels were influenced by the 222 Rn concentrations in the hot spring water and the bathing times. The average 222 Rn transfer coefficients from water to air were 6.2 x 10 -4 -4.1 x 10 -3 . The 24-h average levels of CO 2 and PM 10 in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM 2.5 . Radon and PM 10 levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants. - Highlights: → 222 Rn-bearing water is the main contributor to indoor radon in hot spring hotel. → The PM 2.5 and CO 2 are also the main indoor pollutants in the hotel rooms. → Higher radon and PM levels might have significant negative health effects to human. → The radon transfer coefficients are consistent with the published data.

  8. RN-BSN Students' Perceptions of the Differences in Practice of the ADN- and BSN-Prepared RN.

    Science.gov (United States)

    Matthias, April D; Kim-Godwin, Yeoun Soo

    2016-01-01

    This study explored RN-BSN students' perceptions of practice differences between nurses prepared with an ADN and BSN. Five themes were identified in 20 students' discussion posts: "a nurse is a nurse" at the bedside, beyond the bedside, BSN wanted, digging deeper, and appraisal. Results illustrate the need for educators to assist nurses in translating the differentiated educational competencies to the practice role of the bedside RN.

  9. Fra anbringelse til efterværn

    DEFF Research Database (Denmark)

    Dreyer Espersen, Laila

    Når anbragte børn fylder 18 år, ophører deres anbringelse formelt set. Det betyder, at den unge som udgangspunkt skal klare sig selv. Men den nye efterværnsparagraf (§ 62a) i serviceloven giver mulighed for fortsat at støtte de unge, indtil de fylder 23 år. Det benytter man sig af på forskellig...... måde og i varierende omfang i danske kommuner. I denne rapport fremhæves gennem interview med 16 sagsbehandlere, en kommunalt ansat kontaktperson og en medarbejder ved en privat plejehjemsforening fra 10 kommuner nogle af de aspekter af efterværnsindsatsen, som kan være afgørende for, om den unge...... kommer godt ud af anbringelsen. Der er især fokuseret på de positive erfaringer, som sagsbehandlerne har haft i deres daglige arbejde med de unge i efterværnsforløb....

  10. Contribution of 222Rn in domestic water supplies to 222Rn in indoor air in Colorado homes

    International Nuclear Information System (INIS)

    Lawrence, E.P.; Wanty, R.B.; Nyberg, P.

    1992-01-01

    The contribution of 222Rn from domestic water wells to indoor air was investigated in a study of 28 houses near Conifer, CO. Air concentrations determined by alpha-track detectors (ATDs) and continuous radon monitors were compared with the predictions of a single-cell model. In many of the houses, the water supply was shown to contribute significantly to levels of indoor 222Rn. The data from the ATD study were augmented with a continuous monitoring study of a house near Lyons, CO. The well water in that house has the highest known concentration of 222Rn in water yet reported (93 MBq m-3). The temporal pattern in the indoor 222Rn concentration corresponds to water-use records. In general, it is difficult to quantify the proportion of indoor radon attributable to water use. Several lines of evidence suggest that the single-cell model underestimates this proportion. Continuous-monitoring data, although useful, are impractical due to the cost of the equipment. We propose a protocol for 222Rn measurement based on three simultaneous integrating radon detectors that may help estimate the proportion of indoor 222Rn derived from the water supply

  11. Short-term 222Rn activity concentration changes in underground spaces with limited air exchange with the atmosphere

    Science.gov (United States)

    Fijałkowska-Lichwa, L.; Przylibski, T. A.

    2011-04-01

    considered solution for the ventilation system not only does not prevent radioactive exposure of the staff, but can even increase it. The authors have also observed comparable characteristics of the annual patterns of 222Rn activity concentration changes in underground spaces and residential buildings situated in the same or similar climatic zones.

  12. Monitoramento de tempo e temperatura de distribuição de preparações à base de carne em escolas municipais de Natal (RN, Brasil Monitoring exposure time and distribution temperature of meat-based meals served in municipal schools in Natal, Brazil

    Directory of Open Access Journals (Sweden)

    Monique Silveira Rosa

    2008-02-01

    Full Text Available OBJETIVO: Monitorar o tempo e a temperatura de distribuição de preparações à base de carne servidas em escolas municipais de Natal (RN. MÉTODOS: Foram selecionadas 27 escolas da rede municipal de ensino, de forma aleatória, divididas em estratos por diferentes regiões administrativas. As medições de temperatura de preparações à base de carne foram verificadas quatro vezes em cada escola e o tempo de exposição destas foi verificado ao final da cocção e no início e no final da distribuição, com um termômetro digital do tipo espeto e relógio digital. Os resultados foram comparados com os padrões da resolução da diretoria colegiada nº 216/2004, da Agência Nacional de Vigilância Sanitária do Ministério da Saúde. RESULTADOS: Para temperatura de cocção, 100% das escolas apresentaram-se dentro dos padrões (acima de 70ºC. Entretanto, no início e no final da distribuição, 100% das escolas das Regiões Leste e Sul apresentaram temperaturas inadequadas (abaixo de 60ºC. Na Região Oeste 70% das escolas apresentaram temperaturas em desacordo no início da distribuição e 90% no final dessa etapa. Na Região Norte verificou-se que 91% das escolas apresentaram temperaturas impróprias no início e 82% no final da distribuição. As médias do tempo de espera das preparações foram de 59, 49, 66 e 48 minutos para as regiões Leste, Oeste, Norte e Sul, respectivamente. CONCLUSÃO: Há necessidade da adoção de Boas Práticas nas escolas municipais de Natal, a fim de uma manutenção efetiva da temperatura de distribuição das refeições no intuito de garantir uma alimentação de qualidade sanitária satisfatória aos escolares, evitando-se as intoxicações alimentares decorrentes da ineficácia das temperaturas.OBJECTIVE: To monitor exposure time and temperature of meat-based meals served in municipal schools in Natal, Brazil. METHODS: Twenty-seven municipal schools were randomly selected and stratified by

  13. Preliminary experiences with 222Rn gas in Arizona homes

    International Nuclear Information System (INIS)

    Kearfott, K.J.

    1989-01-01

    Results of a survey of 222Rn gas using four-day charcoal canister tests in 759 Arizona homes are reported. Although the study was not random with respect to population or land area, it was useful in identifying areas at risk and locating several homes having elevated indoor 222Rn air concentrations. Approximately 18% of the homes tested exceeded 150 Bq m-3 (4 pCi L-1), with 7% exceeding 300 Bq m-3 (8 pCi L-1). Several Arizona cities had larger fractions of homes exceeding 150 Bq m-3 (4 pCi L-1), such as Carefree and Cave Creek (23%), Paradise Valley (30%), Payson (33%), and Prescott (31%). The Granite Dells and Groom Creek areas of Prescott had in excess of 40-60% of the houses tested exceeding 150 Bq m-3 (4 pCi L-1). Elevated 222Rn concentrations were measured for a variety of home types having different construction materials. Private well water was identified as a potentially significant source of 222Rn gas in Prescott homes, with water from one well testing over 3.5 MBq m-3 (94,000 pCi L-1). A 222Rn concentration in air exceeding 410,000 Bq m-3 (11,000 pCi L-1) was measured using a four-day charcoal canister test in a house in Prescott which had a well opening into a living space. Additional measurements in this 150-m3 dwelling revealed a strikingly heterogeneous 222Rn concentration. The excessive 222Rn level in the dwelling was reduced to less than 190 Bq m-3 (5.2 pCi L-1) by sealing the well head with caulking and providing passive ventilation through a pipe

  14. Wire chambers: Trends and alternatives

    Energy Technology Data Exchange (ETDEWEB)

    Regler, Meinhard

    1992-05-15

    The subtitle of this year's Vienna Wire Chamber Conference - 'Recent Trends and Alternative Techniques' - signalled that it covered a wide range of science and technology. While an opening Vienna talk by wire chamber pioneer Georges Charpak many years ago began 'Les funerailles des chambres a fils (the burial of wire chambers)', the contrary feeling this year was that wire chambers are very much alive!.

  15. DELPHI Barrel Muon Chamber Module

    CERN Multimedia

    1989-01-01

    The module was used as part of the muon identification system on the barrel of the DELPHI detector at LEP, and was in active use from 1989 to 2000. The module consists of 7 individual muons chambers arranged in 2 layers. Chambers in the upper layer are staggered by half a chamber width with respect to the lower layer. Each individual chamber is a drift chamber consisting of an anode wire, 47 microns in diameter, and a wrapped copper delay line. Each chamber provided 3 signal for each muon passing through the chamber, from which a 3D space-point could be reconstructed.

  16. 222Rn Measurements in Dwellings of Argentina

    International Nuclear Information System (INIS)

    Gnoni, G.; Canoba, A.; Czerniczyniec, M.

    2011-01-01

    Radon gas ( 222 Rn) is responsible of about fifty per cent of the world population dose due to natural sources, being the most important pathway the inhalation of radon progeny, specially indoors. Radon concentration has been measured in dwellings at different locations in Argentina. The places selected to be evaluated are representative of the different geologic zones of the country. Near 3000 dwellings have been analyzed since 1983 up today. The measuring methods used in this case were track etched detectors, electrets and detectors based on activated charcoal adsorption. Two different methods with track etched detectors were used: a simple one, which determines only the average radon concentration, and a second one that measures both radon concentration and the equilibrium factor (F) between radon and its daughters. The last one is a method that uses two Makrofol passive track detectors in the same device. The average radon concentration value obtained from all the dwellings evaluated was 44.2 Bq.m-3. The annual effective dose calculated from this average concentration, using a dosimetric factor of 25 μSv.a- 1. (Bq.m -3 ) -1 , which assumes an equilibrium factor of 0.4, was 1.11 mSv. The average value obtained from the 222 dwellings evaluated by the second method was 49.3 Bq.m -3 and 0,37 the equilibrium factor, resulting the annual effective dose estimated 1,44 mSv. The measured equilibrium factor of 0,37 allows us to verify the assumed equilibrium factor of 0,4. Finally, radon levels in dwellings of Argentina are within the acceptable values for population, not being necessary to implement remedial actions, except in isolate cases that are still under study. (authors)

  17. Radon diffusion chamber

    International Nuclear Information System (INIS)

    Pretzsch, G.; Boerner, E.; Lehmann, R.; Sarenio, O.

    1986-01-01

    The invention relates to the detection of radioactive gases emitting alpha particles like radon, thoron and their alpha-decaying daughters by means of a diffusion chamber with a passive detector, preferably with a solid state track detector. In the chamber above and towards the detector there is a single metallized electret with negative polarity. The distance between electret and detector corresponds to the range of the alpha particles of radon daughters in air at the most. The electret collects the positively charged daughters and functions as surface source. The electret increases the sensitivity by the factor 4

  18. The Honeycomb Strip Chamber

    International Nuclear Information System (INIS)

    Graaf, Harry van der; Buskens, Joop; Rewiersma, Paul; Koenig, Adriaan; Wijnen, Thei

    1991-06-01

    The Honeycomb Strip Chamber (HSC) is a new position sensitive detector. It consists of a stack of folded foils, forming a rigid honeycomb structure. In the centre of each hexagonal cell a wire is strung. Conducting strips on the foils, perpendicular to the wires, pick up the induced avalanche charge. Test results of a prototype show that processing the signals form three adjacent strips nearest to the track gives a spatial resolution better than 64 μm for perpendicular incident tracks. The chamber performance is only slightly affected by a magnetic field. (author). 25 refs.; 21 figs

  19. Multiple chamber ionization detector

    International Nuclear Information System (INIS)

    Solomon, E.E.

    1982-01-01

    An ionization smoke detector employs a single radiation source in a construction comprising at least two chambers with a center or node electrode. The radioactive source is associated with this central electrode, and its positioning may be adjusted relative to the electrode to alter the proportion of the source that protrudes into each chamber. The source may also be mounted in the plane of the central electrode, and positioned relative to the center of the electrode. The central electrode or source may be made tiltable relative to the body of the detector

  20. Charpak hemispherical wire chamber

    CERN Multimedia

    1970-01-01

    pieces. Mesures are of the largest one. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  1. micro strip gas chamber

    CERN Multimedia

    1998-01-01

    About 16 000 Micro Strip Gas Chambers like this one will be used in the CMS tracking detector. They will measure the tracks of charged particles to a hundredth of a millimetre precision in the region near the collision point where the density of particles is very high. Each chamber is filled with a gas mixture of argon and dimethyl ether. Charged particles passing through ionise the gas, knocking out electrons which are collected on the aluminium strips visible under the microscope. Such detectors are being used in radiography. They give higher resolution imaging and reduce the required dose of radiation.

  2. 222Rn flux and soil air concentration profiles in West-Germany. Soil 222Rn as tracer for gas transport in the unsaturated soil zone

    International Nuclear Information System (INIS)

    Doerr, H.; Muennich, K.O.

    1990-01-01

    Measurements of the 222 Rn activity concentration profile in the soil and the 222 Rn flux in West-Germany are presented. The spatial pattern of the 222 Rn flux depends more on soil type than on the 226 Ra activity of the soil material. The average 222 Rn flux from sandy soils is 1000-2000 dpm m -2 h -1 and 4000-6000 dpm m -2 h -1 froam loamy and clayey soils. Weekly 222 Rn flux measurements during a period of 1 year at a sandy site show no significant temporal variations. At a clayey site, the 222 Rn flux tends to be higher in summer than in winter. The permeability coefficient P Rn , obtained from simultaneous 222 Rn flux and concentration profile measurements in various soils, can be expressed as a function of the soil parameters total porosity ε 0 , soil moisture F, tortuosity k and the molecular diffusion coefficient D 0 of 222 Rn in air: P = D 0 ((ε 0 -F)/k-const.). The flux of any other gas into or out of the soil can thus be calculated from its measured concentration profile in the soil and from the 222 Rn permeability coefficient, replacing the molecular diffusion coefficient of 222 Rn by that of the specific gas under consideration. As an example, this method of flux determination is demonstrated for the soil CO 2 flux to the atmosphere and for the flux of atmospheric CH 4 into the soil. (author) 14 refs

  3. Radon exposure system for mammalian cells in culture: Design, operation, and dosimetry

    International Nuclear Information System (INIS)

    Seed, T.M.; Kretz, N.D.; Schlenker, R.A.

    1991-01-01

    A novel system for Rn gas exposure of mammalian cells in culture has been designed, constructed, and used to directly assess both the magnitude and the nature of chronic, low-dose Rn/Rn daughter toxicity of exposed vital lung cells isolated from normal pulmonary tissue, propagated and exposed in vitro. Direct correlations between atmospheric Rn concentrations, alpha-particle fluences, and macro- and microdoses of absorbed radiation doses by lung cells provide for a heretofore unavailable assessment of critical doses to vital cells

  4. Unit type differences in RN workgroup job satisfaction.

    Science.gov (United States)

    Boyle, Diane K; Miller, Peggy A; Gajewski, Byron J; Hart, Sara E; Dunton, Nancy

    2006-10-01

    Using cross-sectional data from the 2004 National Database of Nursing Quality Indicators (NDNQI) RN Satisfaction Survey, differences in RN workgroup job satisfaction were examined among 10 unit types--medical-surgical, step-down, critical care, pediatric, maternal-newborn, psychiatric, emergency department, rehabilitation, surgical services, and outpatient clinics and labs. The national sample included RN workgroups in 2,900 patient care units (55,516 RNs; 206 hospitals in 44 states). Workgroup satisfaction across all unit types was moderate. RN workgroups in pediatric units were the most satisfied, whereas those in surgical services and emergency department unit types were least satisfied. A consistent finding across all unit types was high satisfaction with the specific domains of nurse-to-nurse interaction, professional status, and professional development versus much lower satisfaction with task, decision making, and pay. Findings can be used to inform and develop investigations that examine specific aspects of the work environment for RN workgroups in various unit types.

  5. Diesel oil removal by immobilized Pseudoxanthomonas sp. RN402.

    Science.gov (United States)

    Nopcharoenkul, Wannarak; Netsakulnee, Parichat; Pinyakong, Onruthai

    2013-06-01

    Pseudoxanthomonas sp. RN402 was capable of degrading diesel, crude oil, n-tetradecane and n-hexadecane. The RN402 cells were immobilized on the surface of high-density polyethylene plastic pellets at a maximum cell density of 10(8) most probable number (MPN) g(-1) of plastic pellets. The immobilized cells not only showed a higher efficacy of diesel oil removal than free cells but could also degrade higher concentrations of diesel oil. The rate of diesel oil removal by immobilized RN402 cells in liquid culture was 1,050 mg l(-1) day(-1). Moreover, the immobilized cells could maintain high efficacy and viability throughout 70 cycles of bioremedial treatment of diesel-contaminated water. The stability of diesel oil degradation in the immobilized cells resulted from the ability of living RN402 cells to attach to material surfaces by biofilm formation, as was shown by CLSM imaging. These characteristics of the immobilized RN402 cells, including high degradative efficacy, stability and flotation, make them suitable for the purpose of continuous wastewater bioremediation.

  6. Study of tourists exposure rate in Mahallat hot Spring Region

    International Nuclear Information System (INIS)

    Tavakoli, H. M.B.; Fallah, M.G.; Ghiasinejad, M.

    2006-01-01

    Introduction: High level radiation areas have been recognized on various parts of the earth. Some of these areas include: Brasilia, India, and Iran. Mahallat hot spring region in the central part of Iran is also one of these areas. Study of exposure in these areas could be helpful in investigating the effects of ionizing radiation. Materials and Methods: In addition to several seasonal springs, Mahallat hot spring region contains five permanent springs named: Soleimani, Shafa, Dombe, Romatism and Sauda. Internal exposure (due to inhalation of radon gas and drinking water) and external exposure (due to cosmic rays and radioactive elements in the ground) to the tourists was studied. Used materials and apparatus include: RSS -112 ionizing chamber for environmental gamma rays exposure measurement, highly pure germanium detector for measuring radioactive elements in the ground, liquid scintillation counter for measuring 222 Rn gas concentration in water samples, Bubbler chamber and Locus cells for Rn concentration measurements (Emanation method) and Alfa guard detector for 226 Ra concentration measurements. Conclusions and Discussion: A total of 270 visitors are included in this study. Considering residual durations of the studied group in open and closed environment of bathrooms, hotel and inn rooms, obtained annual external effective dose is 75.4±8.7μSv and 138.3±11.8μSv for natives and travelers respectively. EEC coefficients has been used for calculating annual internal effective dose due to radon gas inhalation. Annual internal effective dose, in this path, is 0.9 and 2.1 mSv in open and closed environment for native and visitors respectively. Annual internal effective dose due to drinking water, is 0.43 and 0.09μSv for natives people and travelers, respectively. Measurements show that more than 90% of the received dose in the studied groups is due to radon gas inhalation. External and internal dose summation is 0.98 mSv for natives and 2.2 mSv for for

  7. Study of tourists exposure rate in Mahallat hot Spring Region

    Energy Technology Data Exchange (ETDEWEB)

    Tavakoli, H. M.B. [Isfahan Univ. of Medical Sciences, Isfahan (Iran, Islamic Republic of); Fallah, M.G. [Isfahan University of Medical Sciences (Iran, Islamic Republic of); Ghiasinejad, M. [Iran Atomic Energy Organization, Tehran (Iran, Islamic Republic of)

    2006-07-01

    Introduction: High level radiation areas have been recognized on various parts of the earth. Some of these areas include: Brasilia, India, and Iran. Mahallat hot spring region in the central part of Iran is also one of these areas. Study of exposure in these areas could be helpful in investigating the effects of ionizing radiation. Materials and Methods: In addition to several seasonal springs, Mahallat hot spring region contains five permanent springs named: Soleimani, Shafa, Dombe, Romatism and Sauda. Internal exposure (due to inhalation of radon gas and drinking water) and external exposure (due to cosmic rays and radioactive elements in the ground) to the tourists was studied. Used materials and apparatus include: RSS -112 ionizing chamber for environmental gamma rays exposure measurement, highly pure germanium detector for measuring radioactive elements in the ground, liquid scintillation counter for measuring {sup 222}Rn gas concentration in water samples, Bubbler chamber and Locus cells for Rn concentration measurements (Emanation method) and Alfa guard detector for {sup 226}Ra concentration measurements. Conclusions and Discussion: A total of 270 visitors are included in this study. Considering residual durations of the studied group in open and closed environment of bathrooms, hotel and inn rooms, obtained annual external effective dose is 75.4{+-}8.7{mu}Sv and 138.3{+-}11.8{mu}Sv for natives and travelers respectively. EEC coefficients has been used for calculating annual internal effective dose due to radon gas inhalation. Annual internal effective dose, in this path, is 0.9 and 2.1 mSv in open and closed environment for native and visitors respectively. Annual internal effective dose due to drinking water, is 0.43 and 0.09{mu}Sv for natives people and travelers, respectively. Measurements show that more than 90% of the received dose in the studied groups is due to radon gas inhalation. External and internal dose summation is 0.98 mSv for natives and 2

  8. Dosimetry of Rn-222 in the air in environments located above and below ground level; Dosimetria de Rn-222 no ar em ambientes localizados acima e abaixo do nivel do solo

    Energy Technology Data Exchange (ETDEWEB)

    Cazula, Camila Dias

    2015-07-01

    Exposure of the general population to ionizing radiation comes mainly from natural sources. The main contribution is due to inhalation of radon (Rn-222), a gas that occurs naturally (UNSCEAR, 2000). The Rn-222 concentration in the environment is controlled by factors such as soil permeability and water content, the weather variability, materials used in the foundation and the usual positive pressure differential between the soil and the internal environment. Studies indicate that the concentration of radon shows a wide variation in the basement, ground floor and upper floors of buildings. The objective of this study is to determine radon levels in basements, ground floor and floors above ground level, at a university in the city of Sao Paulo and in one residential building in the city of Peruibe. Rn-222 measurements were performed using the method with nuclear track of solid state detectors (CR-39). The studied environments present Rn-222 concentration well below the values recommended by the International Commission on Radiological Protection, published in the 2009 document, of 300 Bq/m{sup 3} for homes and 1000 Bq/m{sup 3} for the workplace. In the residential building, the concentration of Ra-266, Th-232 and K-40 in the materials used in the building construction was also analyzed, by gamma spectrometry. The effective total dose for the resident due to external exposure was 0.8 mSv y{sup -1}, lower than the annual dose limit for the general public of 1 mSv y{sup -1}. (author)

  9. Estimated doses related to 222Rn concentration in bunker for radiotherapy and storage of radioisotopes

    International Nuclear Information System (INIS)

    Mestre, Freddy; Carrizales-Silva, Lila; Sajo-Bohus, Laszlo; Diaz, Cruz

    2013-01-01

    It was done a survey in radiotherapy services underground hospitals and clinics of Venezuela and Paraguay in order to estimate the concentrations of radon and its possible consequences on worker occupational exposure. Passive dosimeters were used to assess nuclear traces (NTD type CR-39®). The concentration of 222 Rn is determined based on the density of traces using the calibration coefficient of 1 tr/cm 2 equivalent to 0,434 Bqm -3 per month of exposure. Assuming the most likely environmental conditions and the dose conversion factor equal to 9.0 x 10 -6 mSv h -1 by Bqm -3 , it was determined the average values and estimated the possible risks to health that are on average 3.0 mSva -1 and 150 micro risk cancer

  10. Distribution of 222Rn in dwellings around proposed uranium mining site at Rohil, Rajasthan

    International Nuclear Information System (INIS)

    Jha, V.N.; Kumar, Rajesh; Singh, M.K.; Patnaik, R.L.; Sahoo, S.K.; Jha, S.K.; Tripathi, R.M.

    2018-01-01

    Prior to commissioning of uranium ore mining and processing facility baseline radiological monitoring vis-a-vis public exposure assessment is required. Such information are utilized for developing control measures during operational phases to ascertain the minimal impact on the surrounding areas. Among the various pathways the inhalation component far exceeds the other component in the natural background of a region. Further, in inhalation component also the contribution of 222 Rn is almost 50%. The main sources of indoor radon are geological features, soil characteristics, construction materials of the dwellings, water utilization pattern, use of natural cooking gas, climatological/weather variables. As part of preliminary radiological assessment exercise twenty three dwellings were selected in this region comprising of different types of construction design/materials and passive radon dosimeters were provided of evaluation of radon level and inhalation exposure. The results presented in the text are part of the said radiological assessment exercise

  11. LEP vacuum chamber, prototype

    CERN Multimedia

    CERN PhotoLab

    1983-01-01

    Final prototype for the LEP vacuum chamber, see 8305170 for more details. Here we see the strips of the NEG pump, providing "distributed pumping". The strips are made from a Zr-Ti-Fe alloy. By passing an electrical current, they were heated to 700 deg C.

  12. Heavy liquid bubble chamber

    CERN Multimedia

    CERN PhotoLab

    1965-01-01

    The CERN Heavy liquid bubble chamber being installed in the north experimental hall at the PS. On the left, the 1180 litre body; in the centre the magnet, which can produce a field of 26 800 gauss; on the right the expansion mechanism.

  13. The KLOE drift chamber

    International Nuclear Information System (INIS)

    Ferrari, A.

    2002-01-01

    The design and construction of the large drift chamber of the KLOE experiment is presented. The track reconstruction is described, together with the calibration method and the monitoring systems. The stability of operation and the performance are studied with samples of e + e - , K S K L and K + K - events

  14. Drift chamber detectors

    International Nuclear Information System (INIS)

    Duran, I.; Martinez Laso, L.

    1989-01-01

    A review of High Energy Physics detectors based on drift chambers is presented. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysied, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author)

  15. Drift Chambers detectors

    International Nuclear Information System (INIS)

    Duran, I.; Martinez laso, L.

    1989-01-01

    We present here a review of High Energy Physics detectors based on drift chambers. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysed, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author) 115 refs

  16. OPAL Muon Chamber

    CERN Multimedia

    OPAL was one of the 4 experiments installed at the LEP particle accelerator from 1989 to 2000. This is a slice of the outermost layer of OPAL : the muon chambers. This outside layer detects particles which are not stopped by the previous layers. These are mostly muons.

  17. Improvements in ionization chambers

    International Nuclear Information System (INIS)

    Whetten, N.R.; Zubal, C.

    1980-01-01

    A method of reducing mechanical vibrations transmitted to the parallel plate electrodes of ionization chamber x-ray detectors, commonly used in computerized x-ray axial tomography systems, is described. The metal plate cathodes and anodes are mounted in the ionizable gas on dielectric sheet insulators consisting of a composite of silicone resin and glass fibres. (UK)

  18. LEP Vacuum Chamber

    CERN Multimedia

    1983-01-01

    This is a cut-out of a LEP vacuum chamber for dipole magnets showing the beam channel and the pumping channel with the getter (NEG) strip and its insulating supports. A water pipe connected to the cooling channel can also be seen at the back.The lead radiation shield lining is also shown. See also 8305563X.

  19. MISSING: BUBBLE CHAMBER LENS

    CERN Multimedia

    2001-01-01

    Would the person who borrowed the large bubble chamber lens from the Microcosm workshops on the ISR please return it. This is a much used piece from our object archives. If anybody has any information about the whereabouts of this object, please contact Emma.Sanders@cern.ch Thank you

  20. Ion chamber instrument

    International Nuclear Information System (INIS)

    Stephan, D.H.

    1975-01-01

    An electrical ionization chamber is described having a self-supporting wall of cellular material which is of uniform areal density and formed of material, such as foamed polystyrene, having an average effective atomic number between about 4 and about 9, and easily replaceable when on the instrument. (auth)

  1. Review of straw chambers

    International Nuclear Information System (INIS)

    Toki, W.H.

    1990-03-01

    This is a review of straw chambers used in the HRS, MAC, Mark III, CLEO, AMY, and TPC e + e - experiments. The straws are 6--8 mm in diameter, operate at 1--4 atmospheres and obtain resolutions of 45--100 microns. The designs and constructions are summarized and possible improvements discussed

  2. Liquid Wall Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Meier, W R

    2011-02-24

    The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.

  3. Wire chamber conference

    International Nuclear Information System (INIS)

    Bartl, W.; Neuhofer, G.; Regler, M.

    1986-02-01

    This booklet contains program and the abstracts of the papers presented at the conference, most of them dealing with performance testing of various types of wire chambers. The publication of proceedings is planned as a special issue of 'Nuclear instruments and methods' later on. All abstracts are in English. An author index for the book of abstracts is given. (A.N.)

  4. Determine concentration radon 222Rn in the air inside and outside the buildings at the summer province of Baghdad

    International Nuclear Information System (INIS)

    Al-Ataby, N.R.; Aisa, B.H.; Jebir, H.M.; Hatem, J.N.

    2010-01-01

    In this study, Was use of solid-state nuclear track detectors in the measurement of concentrations of radon 222 Rn inside and outside of the buildings in the summer and winter of the Baghdad province and because of the high features of the technical sensitivity and efficiency to record track of charged particles (such as protons and alpha particles and fission fragments) . Is the radon of Environmental Pollutions that is caused health problems , that was seemed the concern at the problem of pollution, radon gas 222 Rn and thoron gas 220 Rn and the considerable risk resulting from exposure to these isotopes by alpha particles emitted which have proved the relationship between exposure to emitted alpha particles with the incidence of disease of lung cancer. In this study, measured the concentration of radon 222 Rn inside and outside buildings in the summer and winter in several areas from the Baghdad province and as showed in the attached tables. Been studied the environmental radioactivity and measurement of the concentration of radon gas in the air in different parts of the city of Baghdad. the highest concentration was Found in the second Orf ali (A) (of the Sadr City) for the summer and was (37.973 Bq/m3) outside the building and ((53.400 Bq/m3 inside the building, either for the winter season was (55.773 Bq/m3) outside the building and (Bq/m3 58.148) inside the building for the same region and This is the concentration within the limits allowed

  5. COOMET.RI(II)-S1.Rn-222 (169/UA/98): Rn-222 volume activity comparison

    International Nuclear Information System (INIS)

    Skliarov, V.; Rottger, A.; Honig, A.; Korostin, S.; Kuznetsov, S.; Lapenas, A.; Milevsky, V.; Ivaniukovich, A.; Kharitonov, I.; Sepman, S.

    2009-01-01

    According to a first program, a supplementary comparison of Rn-222 volume activity was drawn up as a bilateral supplementary comparison between NSC 'Institute of Metrology', Ukraine, and VNIIFTRI, Russia. It took place in March 2005. In April 2005, at the 5. meeting of COOMET held in Braunschweig (Germany), representatives of these institutes exchanged data which showed the comparability of the national standards of Ukraine and Russia for the check points. During the discussion of the procedure some other institutes decided to join the comparison program, which was extended to BelGIM (Belarus), PTB (Germany), VNIIM (Russia) and RMTC (Latvia). The national standards of volume activity of radon-222 were thus calibrated using one standard radon radiometer as the transfer standard. Results are shown in the Final Report of the comparison. (authors)

  6. COOMET.RI(II)-S1.Rn-222 (169/UA/98): Rn-222 volume activity comparison

    Energy Technology Data Exchange (ETDEWEB)

    Skliarov, V. [National Scientific Centre, Institute of Metrology (NSC IM), Kharkiv (Ukraine); Rottger, A.; Honig, A. [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany); Korostin, S.; Kuznetsov, S. [All-Russian Scientific Research Institute of Physical, Technical and Radio Measurements (VNIIFTRI), Moscow Region, Mendeleyevo (Russian Federation); Lapenas, A. [Latvian National Metrology Centre Ltd, Radiation Metrology and Testing Centre (RMTC), Salaspils (Latvia); Milevsky, V.; Ivaniukovich, A. [Belarussian State Institute of Metrology (BelGIM), Minsk (Belarus); Kharitonov, I.; Sepman, S. [D I Mendeleyev Institute of metrology (VNIIM), Saint Petersburg (Russian Federation)

    2009-06-15

    According to a first program, a supplementary comparison of Rn-222 volume activity was drawn up as a bilateral supplementary comparison between NSC 'Institute of Metrology', Ukraine, and VNIIFTRI, Russia. It took place in March 2005. In April 2005, at the 5. meeting of COOMET held in Braunschweig (Germany), representatives of these institutes exchanged data which showed the comparability of the national standards of Ukraine and Russia for the check points. During the discussion of the procedure some other institutes decided to join the comparison program, which was extended to BelGIM (Belarus), PTB (Germany), VNIIM (Russia) and RMTC (Latvia). The national standards of volume activity of radon-222 were thus calibrated using one standard radon radiometer as the transfer standard. Results are shown in the Final Report of the comparison. (authors)

  7. Spectroscopy of 211Rn approaching the valence limit

    International Nuclear Information System (INIS)

    Davidson, P.M.; Dracoulis, G.D.; Kibedi, T.; Fabricius, B.; Baxter, A.M.; Stuchbery, A.E.; Poletti, A.R.; Schiffer, K.J.

    1993-02-01

    High spin states in 211 Rn were populated using the reaction 198 Pt( 18 O,5n) at 96 MeV. The decay was studied using γ-ray and electron spectroscopy. The known level scheme is extended up to a spin of greater than 69/2 and many non-yrast states are added. Semi-empirical shell model calculations and the properties of related states in 210 Rn and 212 Rn are used to assign configurations to some of the non-yrast states. The properties of the high spin states observed are compared to the predictions of the Multi-Particle Octupole Coupling model and the semi-empirical shell model. The maximum reasonable spin available from the valence particles and holes is 77/2 and states are observed to near this limit. 12 refs., 4 tabs., 8 figs

  8. RN Job Satisfaction and Retention After an Interprofessional Team Intervention.

    Science.gov (United States)

    Baik, Dawon; Zierler, Brenda

    2018-04-01

    Despite continuing interest in interprofessional teamwork to improve nurse outcomes and quality of care, there is little research that focuses on nurse job satisfaction and retention after an interprofessional team intervention. This study explored registered nurse (RN) job satisfaction and retention after a purposeful interprofessional team training and structured interprofessional bedside rounds were implemented. As part of a larger study, in this comparative cross-sectional study, pre- and post-intervention data on RN job satisfaction and turnover rate were collected and analyzed. It was found that RNs had significantly higher job satisfaction after the interprofessional team intervention. The 6-month period turnover rate in the post-intervention period was slightly lower than the 6-month period turnover rate in pre-intervention period; however, the rate was too low to provide statistical evidence. Ongoing coaching and supportive work environments to improve RN outcomes should be considered to enhance quality of care and patient safety in healthcare.

  9. Mineral water 222 Rn activity decrease due to consumption habits

    International Nuclear Information System (INIS)

    Cipriani, Moacir; Taddei, Maria Helena Tirollo; Silva, Nivaldo Carlos da

    2001-01-01

    Mineral waters from the Pocos de Caldas Plateau springs, an elevated region with high natural radioactivity, in the State of Minas Gerais, Brazil, have significant 222 Rn concentration on site. The highest concentration in the waters are from: Fonte Villela - Aguas da Prata (∼ 1000 Bql -1 ); Fonte Grande Hotel - Pocinhos do Rio Verde (∼ 400 Brq -1 ) and Fonte CNEN Lab - Pocos de Caldas (∼ 290 Bql -1 ). These waters are used by the population as drinking water and due to consumption habits, can lead to internal doses above accepted limits for the public. This work deals with the decrease of 222 Rn activity in mineral waters fro two different popular consumption habits, and with the adult effective dose equivalent reduction due to water consumption habits. It has been found that the estimated dose based on the biokinetic Crawford-Brown model, can be one fourth of dose based on 222 Rn activity on site. (author)

  10. Spectroscopy of 211Rn approaching the valence limit

    International Nuclear Information System (INIS)

    Davidson, P.M.; Dracoulis, G.D.; Byrne, A.P.; Kibedi, T.; Fabricus, B.; Baxter, A.M.; Stuchbery, A.E.; Poletti, A.R.; Schiffer, K.J.

    1993-01-01

    High-spin states in 211 Rn were populated using the reaction 198 Pt( 18 O, 5n) at 96 MeV. Their decay was studied using γ-ray and electron spectroscopy. The known level scheme is extended up to a spin of greater than 69/2 and many non-yrast states are added. Semi-empirical shell-model calculations and the properties of related states in 210 Rn and 212 Rn are used to assign configurations to some of the non-yrast states. The properties of the high-spin states observed are compared to the predictions of the multi-particle octupole-coupling model and the semi-empirical shell model. The maximum reasonable spin available from the valence particles and holes in 77/2 and states are observed to near this limit. (orig.)

  11. Matérn-based nonstationary cross-covariance models for global processes

    KAUST Repository

    Jun, Mikyoung

    2014-01-01

    -covariance models, based on the Matérn covariance model class, that are suitable for describing prominent nonstationary characteristics of the global processes. In particular, we seek nonstationary versions of Matérn covariance models whose smoothness parameters

  12. Characteristics of the Nursing Practice Environment Associated With Lower Unit-Level RN Turnover.

    Science.gov (United States)

    Nelson-Brantley, Heather V; Park, Shin Hye; Bergquist-Beringer, Sandra

    2018-01-01

    The aim of this study is to examine characteristics of the nursing practice environment associated with lower RN turnover. Identifying characteristics of the practice environment that contribute to lower RN turnover is important for meeting the national quality strategy priority of reducing healthcare costs. Data from 1002 adult care units in 162 National Database of Nursing Quality Indicators participating hospitals were analyzed using multivariate linear regression. The Practice Environment Scale of the Nursing Work Index was used to measure practice environment characteristics. RN turnover was measured at the unit level. Nursing units with higher overall ratings of the nursing practice environment had lower rates of RN turnover. Units with higher RN perceived staffing and resource adequacy experienced significantly lower RN turnover. Unit managers and hospital administrators should consider RN perception of staffing and resource adequacy and the overall practice environment when developing targeted strategies for decreasing RN turnover.

  13. Preliminary evaluation of sup 2 sup 2 sup 2 Rn level in homes and offices in two different regions in Syria

    International Nuclear Information System (INIS)

    Othman, I.; Al-Hushari, M.; Raja, G.

    1996-01-01

    Evaluation of Rn levels was carried out in Homes and offices in Damascus and phosphate mining areas near Palmyra city in Syria. The AEOI radon diffusion dosimeters were used in this study. Electrochemical etching of polycarbonate detectors was used to develop the tracks. A standard source of radon was used for calibration. Radon levels were measured in 98 Homes of workers in the phosphate mining areas and 29 Homes in the Damascus region. The radon diffusion chambers were placed in offices and laboratories of AEC for about four months in average. The results gave an indication of Rn level in Damascus dwellings in spite of the necessity for further comprehensive studies for the city. The radon levels were high in some offices and laboratories where phosphate analyses are carried out or buildings near phosphate storage areas or near surface phosphate rocks occurrence, in comparison with Homes. (author). 7 refs., 3 tabs., 4 figs

  14. Performance characteristics of selected integrating ion chambers

    International Nuclear Information System (INIS)

    Lubenau, J.O.; Liberace, R.

    1977-01-01

    Certain types of integrating ion chambers have been identified as acceptable equipment for a nationwide medical X-ray exposure survey program. In this study, Victoreen 2.5, 5 and 10 R condenser R-chambers, the Victoreen 666 Diagnostic Probe (used in the integrating mode) and the Bendix 200 mR and 5 R low energy dosimeters were evaluated for recombination losses and for energy dependence. Recombination losses were determined for exposure rates ranging from 0.3 to 80 R/sec. Energy dependence was determined for X-ray beam qualities ranging from 45 kVp and 0.83 mm Al first half value layer to 125 kVp and 4.8 mm Al first half value layer. The data enable selection of instruments so that errors from recombination losses and energy dependence can be minimized. (author)

  15. Til julefrokost med Bjørn & Okay

    DEFF Research Database (Denmark)

    Smith-Sivertsen, Henrik

    2012-01-01

    I denne artikel vises med udgangspunkt i en beskrivelse af et specifikt arrangement med det danske danseorkester Bjørn & Okay, hvordan man optræder inden for denne særlige musiktradition. Bjørn & Okays performative udgangspunkt er, at de, trods en status som landskendt orkester med mange hits, i ...... the audience and constantly telling them what to do. At the same time he and the other musicians actively bond with the audience, both onstage and offstage, which helps building the spirit of community, which is the clear goal of the musical performance....

  16. Ole Bjørn Kraft 1893-1980

    DEFF Research Database (Denmark)

    Skov, Christian Houlberg

    2010-01-01

    Ole Bjørn Kraft (1893-1980) var en central konservativ politiker i årene før og efter anden verdenskrig. Han markerede sig som udpræget idépolitiker og opnåede ad flere omgange at blive minister.......Ole Bjørn Kraft (1893-1980) var en central konservativ politiker i årene før og efter anden verdenskrig. Han markerede sig som udpræget idépolitiker og opnåede ad flere omgange at blive minister....

  17. Locating karst depressed columns by means of Rn measurement on the surface

    International Nuclear Information System (INIS)

    Tang Daimao; Liu Hongfu; Duan Hongjie; Duan Lindi; Sui Haichen

    1999-01-01

    The coal mining and the related surface projects are extremely harassed by the underground karst depressed columns. The author discussed the surface Rn concentration's abnormality caused by the karst depressed columns. It is concluded that different kinds of karst depressed column can cause different Rn concentration's abnormality. The α-cup Rn measuring instrument was used for detecting Rn abnormality on the surface in order to locate the underground karst depressed columns

  18. Multiwire proportional chamber development

    Science.gov (United States)

    Doolittle, R. F.; Pollvogt, U.; Eskovitz, A. J.

    1973-01-01

    The development of large area multiwire proportional chambers, to be used as high resolution spatial detectors in cosmic ray experiments is described. A readout system was developed which uses a directly coupled, lumped element delay-line whose characteristics are independent of the MWPC design. A complete analysis of the delay-line and the readout electronic system shows that a spatial resolution of about 0.1 mm can be reached with the MWPC operating in the strictly proportional region. This was confirmed by measurements with a small MWPC and Fe-55 X-rays. A simplified analysis was carried out to estimate the theoretical limit of spatial resolution due to delta-rays, spread of the discharge along the anode wire, and inclined trajectories. To calculate the gas gain of MWPC's of different geometrical configurations a method was developed which is based on the knowledge of the first Townsend coefficient of the chamber gas.

  19. Radial semiconductor drift chambers

    International Nuclear Information System (INIS)

    Rawlings, K.J.

    1987-01-01

    The conditions under which the energy resolution of a radial semiconductor drift chamber based detector system becomes dominated by the step noise from the detector dark current have been investigated. To minimise the drift chamber dark current attention should be paid to carrier generation at Si/SiO 2 interfaces. This consideration conflicts with the desire to reduce the signal risetime: a higher drift field for shorter signal pulses requires a larger area of SiO 2 . Calculations for the single shaping and pseudo Gaussian passive filters indicate that for the same degree of signal risetime sensitivity in a system dominated by the step noise from the detector dark current, the pseudo Gaussian filter gives only a 3% improvement in signal/noise and 12% improvement in rate capability compared with the single shaper performance. (orig.)

  20. What we can learn from measurements of air electric conductivity in 222Rn-rich atmosphere

    Science.gov (United States)

    Seran, E.; Godefroy, M.; Pili, E.; Michielsen, N.; Bondiguel, S.

    2017-02-01

    Electric conductivity of air is an important characteristic of the electric properties of an atmosphere. Testing instruments to measure electric conductivity ranging from 10-13 to 10-9 S m-1 in natural conditions found in the Earth atmosphere is not an easy task. One possibility is to use stratospheric balloon flights; another (and a simpler one) is to look for terrestrial environments with significant radioactive decay. In this paper we present measurements carried out with different types of conductivity sensors in two 222Rn-rich environments, i.e., in the Roselend underground tunnel (French Alps) and in the Institute of Radioprotection and Nuclear Safety BACCARA (BAnC de CAllibrage du RAdon) chamber. The concept of the conductivity sensor is based on the classical time relaxation method. New elements in our design include isolation of the sensor sensitive part (electrode) from the external electric field and sensor miniaturization. This greatly extends the application domain of the sensor and permits to measure air electric conductivity when the external electric field is high and varies from few tens of V m-1 to up to few tens of kV m-1. This is suitable to propose the instrument for a planetary mission. Two-fold objectives were attained as the outcome of these tests and their analysis. First was directly related to the performances of the conductivity sensors and the efficiency of the conductivity sensor design to shield the external electric field. Second objective aimed at understanding the decay mechanisms of 222Rn and its progeny in atmosphere and the impact of the enclosed space on the efficiency of gas ionization.

  1. Vienna Wire Chamber Conference

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    After those of 1978 and 1980, a third Wire Chamber Conference was held from 15-18 February in the Technical University of Vienna. Eight invited speakers covered the field from sophisticated applications in biology and medicine, via software, to the state of the art of gaseous detectors. In some forty other talks the speakers tackled in more detail the topics of gaseous detectors, calorimetry and associated electronics and software

  2. Wire chamber gases

    International Nuclear Information System (INIS)

    Va'vra, J.

    1992-04-01

    In this paper, we describe new developments in gas mixtures which have occurred during the last 3--4 years. In particular, we discuss new results on the measurement and modeling of electron drift parameters, the modeling of drift chamber resolution, measurements of primary ionization and the choice of gas for applications such as tracking, single electron detection, X-ray detection and visual imaging. In addition, new results are presented on photon feedback, breakdown and wire aging

  3. Intercomparison of active, passive and continuous instruments for radon and radon progeny measurements in the EML chamber and test facility

    International Nuclear Information System (INIS)

    Scarpitta, S.C.; Tu, K.W.; Fisenne, I.M.; Cavallo, A.; Perry, P.

    1996-10-01

    Results are presented from the Fifth Intercomparison of Active, Passive and Continuous Instruments for Radon and Radon Progeny Measurements conducted in the EML radon exposure and test facility in May 1996. In total, thirty-four government, private and academic facilities participated in the exercise with over 170 passive and electronic devices exposed in the EML test chamber. During the first week of the exercise, passive and continuous measuring devices were exposed (usually in quadruplicate) to about 1,280 Bq m -3 222 Rn for 1--7 days. Radon progeny measurements were made during the second week of the exercise. The results indicate that all of the tested devices that measure radon gas performed well and fulfill their intended purpose. The grand mean (GM) ratio of the participants' reported values to the EML values, for all four radon device categories, was 0.99 ± 0.08. Eighty-five percent of all the radon measuring devices that were exposed in the EML radon test chamber were within ±1 standard deviation (SD) of the EML reference values. For the most part, radon progeny measurements were also quite good as compared to the EML values. The GM ratio for the 10 continuous PAEC instruments was 0.90 ± 0.12 with 75% of the devices within 1 SD of the EML reference values. Most of the continuous and integrating electronic instruments used for measuring the PAEC underestimated the EML values by about 10--15% probably because the concentration of particles onto which the radon progeny were attached was low (1,200--3,800 particles cm -3 ). The equilibrium factor at that particle concentration level was 0.10--0.22

  4. A survey of 222Rn in drinking water in mexico city

    International Nuclear Information System (INIS)

    Vasquez-Lopez, C.; Zendejas-Leal, B. E.; Golzarri, J. I.; Espinosa, G.

    2011-01-01

    In Mexico City there are more than 22 millions of inhabitants (10 in the metropolitan area and 12 in the suburban zone) exposed to drinking water. The local epidemiological authorities recognised that exposure to radon contaminated drinking water is a potential health hazard, as has been considered worldwide. The United States Environmental Protection Agency has proposed a limit of 11.1 Bq l -1 for the radon level in drinking water. In Mexico a maximum contamination level of radon in drinking water has not yet even considered. In this work, a 222 Rn study of drinking water in Mexico City has revealed a range of concentrations from background level to 3.8 Bq l -1 . 222 Rn was calculated using a portable degassing system (AquaKIT) associated with an AlphaGUARD measuring system. Samples from 70 wells of the water system of the south of the Valley Basin of Mexico City and from houses of some other political administrative divisions of Mexico City were taken. (authors)

  5. 222Rn determination in mineral waters from the Pocos de Caldas Plateau in Brazil

    International Nuclear Information System (INIS)

    Taddei, M.H.T.; Silva, N.C.; Cipriani, M.

    2002-01-01

    It is estimated that 50% of the radioactive effective dose equivalent to man comes from radon and its radioactivity daughters. The main 222 Rn sources are the soils, building materials and potable waters. There is an especial interest in spas waters with high natural radioactivity. It's considered that the use of these waters as drinking waters is a significant radiation exposure factor, and it is worthwhile to assess the consequent dose. Such estimation has been made for the Pocos de Caldas Plateau, which is a region of high natural radioactivity, from volcanic origin, containing several spas (Aguas da Prata, Caldas, Pocos de Caldas and Andradas). The 222 Rn content was determined in 23 spring waters in Pocos de Caldas and neighboring cities. In water sampling, modified Marinelli flasks were used. The determinations were effected with a high resolution gamma ray spectrometer. High concentration variations were observed in the collected mineral waters, the highest values having been found in Fonte Villela's waters, in Aguas da Prata town (926 Bq/l); Grande Hotel's in Caldas Town (420 Bq/l) and COLAB's in Pocos de Caldas region (289 Bq/l). The annual whole body effective dose equivalent estimate for adult due to water ingestion, using the Crowford-Brown's biokinetic model's adult dose conversion factors, was higher than 1 mSv/year in 61% of the analyzed waters. (author)

  6. A survey of ²²²Rn in drinking water in Mexico City.

    Science.gov (United States)

    Vázquez-López, C; Zendejas-Leal, B E; Golzarri, J I; Espinosa, G

    2011-05-01

    In Mexico City there are more than 22 millions of inhabitants (10 in the metropolitan area and 12 in the suburban zone) exposed to drinking water. The local epidemiological authorities recognised that exposure to radon contaminated drinking water is a potential health hazard, as has been considered worldwide. The United States Environmental Protection Agency has proposed a limit of 11.1 Bq l(-1) for the radon level in drinking water. In Mexico a maximum contamination level of radon in drinking water has not yet even considered. In this work, a (222)Rn study of drinking water in Mexico City has revealed a range of concentrations from background level to 3.8 Bq l(-1). (222)Rn was calculated using a portable degassing system (AquaKIT) associated with an AlphaGUARD measuring system. Samples from 70 wells of the water system of the south of the Valley Basin of Mexico City and from houses of some other political administrative divisions of Mexico City were taken.

  7. Double chambered right ventricle

    International Nuclear Information System (INIS)

    Cho, Chul Koo; Yu, Yun Jeong; Yeon, Kyung Mo; Han, Man Chung

    1983-01-01

    Fourteen cases of double chambered right ventricle were diagnosed angiographically and of these nine cases were confirmed after operation and autopsy at Seoul National University Hospital in recent four years since 1979. The clinical and radiological findings with the emphasis on the cinecardiographic findings were analysed. The summaries of the analysis are as follows: 1. Among 14 cases, 6 cases were male and 8 cases were female. Age distribution was from 4 years to 36 years. 2. In chest x-ray findings, pulmonary vascularity was increased in 8 cases, decreased in 4 cases, and normal in 2 cases. Cardiomegaly was observed in 8 cases and other showed normal heart size. 3. In cinecardiography, 11 cases had interventricular septal defect. Among these 11 cases, VSD located in proximal high pressure chamber was in 2 cases and located in distal low pressure chamber was in 9 cases. 4. The location of aberrant muscle bundle in sinus portion of right ventricle was in 8 cases. In the rest 6 cases, the aberrant muscle bundle was located below the infundibulum of right ventricle. 5. For accurate diagnosis and differential diagnosis with other congenital cardiac anomalies such as Tetralogy of Fallot or isolated pulmonic stenosis, biplane cineangiography and catheterization is an essential procedure

  8. Double chambered right ventricle

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Chul Koo; Yu, Yun Jeong; Yeon, Kyung Mo; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1983-12-15

    Fourteen cases of double chambered right ventricle were diagnosed angiographically and of these nine cases were confirmed after operation and autopsy at Seoul National University Hospital in recent four years since 1979. The clinical and radiological findings with the emphasis on the cinecardiographic findings were analysed. The summaries of the analysis are as follows: 1. Among 14 cases, 6 cases were male and 8 cases were female. Age distribution was from 4 years to 36 years. 2. In chest x-ray findings, pulmonary vascularity was increased in 8 cases, decreased in 4 cases, and normal in 2 cases. Cardiomegaly was observed in 8 cases and other showed normal heart size. 3. In cinecardiography, 11 cases had interventricular septal defect. Among these 11 cases, VSD located in proximal high pressure chamber was in 2 cases and located in distal low pressure chamber was in 9 cases. 4. The location of aberrant muscle bundle in sinus portion of right ventricle was in 8 cases. In the rest 6 cases, the aberrant muscle bundle was located below the infundibulum of right ventricle. 5. For accurate diagnosis and differential diagnosis with other congenital cardiac anomalies such as Tetralogy of Fallot or isolated pulmonic stenosis, biplane cineangiography and catheterization is an essential procedure.

  9. Argus drift chamber

    Energy Technology Data Exchange (ETDEWEB)

    Danilov, M; Nagovizin, V; Hasemann, H; Michel, E; Schmidt-Parzefall, W; Wurth, R; Kim, P

    1983-11-15

    The ARGUS detector came into operation at the DORIS-II e/sup +/s/sup -/ storage ring at the end of 1982. Its two meter long drift chamber contains 5940 sense and 24588 field wires organized in uniform 18x18.8 mm/sup 2/ drift cells filling the whole volume. These cells form 36 layers, 18 of which provide stereo views. Each sense wire is equipped with a single hit TDC and ADC for coordinate and dE/dx measurements. The chamber is operated with propane to improve momentum and dE/dx resolution. The drift chamber design and initial performance are presented. With a very crude space-time relation approximation and without all the necessary corrections applied a spatial resolution of about 200 ..mu..m was obtained for half of the drift cell volume. Further corrections should improve this result. An intrinsic dE/dx resolution of 4.2% and an actual resolution of 5% were obtained for cosmic muons and also for Bhabha scattered electrons. An actual dE/dx resolution of 5.6% was obtained for pions from e/sup +/e/sup -/ annihilation data with almost no track selection. A relativistic rise of 30% was observed in good agreement with theory. The long-term stability is still to be investigated.

  10. Argus target chamber

    International Nuclear Information System (INIS)

    Rienecker, F. Jr.; Glaros, S.S.; Kobierecki, M.

    1975-01-01

    A target chamber for application in the laser fusion program must satisfy some very basic requirements. (1) Provide a vacuum on the order of 10 -6 torr. (2) Support a microscopically small target in a fixed point in space and verify its location within 5 micrometers. (3) Contain an adjustable beam focusing system capable of delivering a number of laser beams onto the target simultaneously, both in time and space. (4) Provide access for diagnostics to evaluate the results of target irradiation. (5) Have flexibility to allow changes in targets, focusing optics and number of beams. The ARGUS laser which is now under construction at LLL will have a target chamber which meets these requirements in a simple economic manner. The chamber and auxiliary equipment are described, with reference to two double beam focusing systems; namely, lenses and ellipsoidal mirrors. Provision is made for future operation with four beams, using ellipsoidal mirrors for two-sided illumination and lens systems for tetragonal and tetrahedral irradiation

  11. Risk assessment of exposure to radon concentration in indoor atmosphere and drinking water of Shimoga city, Karnataka, India

    International Nuclear Information System (INIS)

    Rangaswamy, D.R.; Sannappa, J.; Srinivasa, E.

    2016-01-01

    The exposure of population to natural sources of radiation has become an important issue in terms of radiological protection. The major contribution of dose from natural radiation in normal background regions arises due to inhalation of alpha-emitting radon and thoron, and their progenies, which are ubiquitous in both indoor and outdoor environs. The aim of the present study is to measure indoor radon, thoron and their progeny levels in the dwellings of Shimoga city and radon concentration in drinking water and to estimate the annual effective dose. The indoor concentration of radon, thoron and their progeny was measured using Solid-State Nuclear Track Detectors (SSNTDs) based twin chamber dosimeter cups. The 222 Rn concentration in drinking water was estimated by the Emanometry technique

  12. Wire chambers: Trends and alternatives

    International Nuclear Information System (INIS)

    Regler, Meinhard

    1992-01-01

    The subtitle of this year's Vienna Wire Chamber Conference - 'Recent Trends and Alternative Techniques' - signalled that it covered a wide range of science and technology. While an opening Vienna talk by wire chamber pioneer Georges Charpak many years ago began 'Les funerailles des chambres a fils (the burial of wire chambers)', the contrary feeling this year was that wire chambers are very much alive!

  13. Energy-dependent etching-related impacts on CR-39 alpha detection efficiency for the Rn-222 and Rn-220 decay chains

    Science.gov (United States)

    Tan, Y.; Yuan, H.; Kearfott, K. J.

    2018-04-01

    CR-39 detectors are widely used to measure environmental levels of Rn-222, Rn-220 and their progeny. Prior research reported the CR-39 detection efficiency for alpha particles from Rn-222, Rn-220 and their progeny under a variety of etching conditions. This paper provides an explanation for interesting observations included in that work, namely that the critical incidence angle decreases with the increasing particle energy and the detection efficiency for 8.78 MeV alpha particles is zero. This paper explains these phenomena from a consideration of the interaction of alpha particles with the CR-39 detectors and the physics of etching dynamics. The proposed theory provides a rationale for an approach to optimizing the etching conditions of CR-39 detector for measuring Rn-222, Rn-220 and their progenies.

  14. Etched track technique to measure sup 2 sup 2 sup 2 Rn and sup 2 sup 2 sup 0 Rn fluxes on soil surface

    CERN Document Server

    Csige, I

    2003-01-01

    sup 2 sup 2 sup 2 Rn and sup 2 sup 2 sup 0 Rn in the human environment are considered to be a risk factor because of the radiation dose due to the inhalation of their short-lived daughters. Main source of radon is usually the soil; therefore the measurement of fluxes of sup 2 sup 2 sup 2 Rn and sup 2 sup 2 sup 0 Rn on soil surfaces is often a relevant parameter to characterise building site radon potential. An etched track detector technique was developed to measure long-time average sup 2 sup 2 sup 2 Rn and sup 2 sup 2 sup 0 Rn fluxes. (R.P.)

  15. Criteria for controlled atmosphere chambers

    International Nuclear Information System (INIS)

    Robinson, J.N.

    1980-03-01

    The criteria for design, construction, and operation of controlled atmosphere chambers intended for service at ORNL are presented. Classification of chambers, materials for construction, design criteria, design, controlled atmosphere chamber systems, and operating procedures are presented. ORNL Safety Manual Procedure 2.1; ORNL Health Physics Procedure Manual Appendix A-7; and Design of Viewing Windows are included in 3 appendices

  16. Two remarks on normality preserving Borel automorphisms of Rn

    Indian Academy of Sciences (India)

    For any θ ∈ Rn and any real n × n positive definite matrix. , let. N(θ, ) denote the n-variate ... nonsingular matrices, positive definite matrices and diagonal matrices with entries ±1. For any matrix A, denote by A ..... In other words, the quadratic form on the right-hand side is a constant on a set of positive. Lebesgue measure.

  17. Vold mod førskolebørn

    DEFF Research Database (Denmark)

    Oldrup, Helene; Lindstrøm, Maia; Korzen, Sara

    Denne rapport handler om praksis og barrierer for opsporing af og underretning om vold mod førskolebørn. Rapporten er baseret på 22 kvalitative interviews med fagfolk inden for dagpasning, sundhedsvæsen og det sociale system. Undersøgelsen viser bl.a., at en del af fagfolkene ofte tøver med at un...

  18. Musikterapi med kontakt- og kommunikationssvage børn

    DEFF Research Database (Denmark)

    Frederiksen, Britta Vinkler

    2009-01-01

    I artiklen beskrives, hvordan musikterapi er med til at støtte en målrettet udviklingsproces hos børn, med diagnoser som Asperger syndrom, autisme, opmærksomhedsforstyrrelser, ADHD o.lign. Musikkens kvaliteter beskrives og illustreres gennem vignetter fra terapiforløb, der alle er foregået i Klinik...

  19. Effects of RN Age and Experience on Transformational Leadership Practices.

    Science.gov (United States)

    Herman, Susan; Gish, Mary; Rosenblum, Ruth; Herman, Michael

    2017-06-01

    This study reported the evolution of transformational leadership (TL) practices and behaviors across years of age, management experience, and professional nursing practice within a professional nursing leadership organization. Recent studies of CNO TL found valuations peak near age 60 years. This study reported on a wider range of management positions, correlating years of RN practice and management experience and age to TL metrics. This study used Kouzes and Posner's Leadership Practices Inventory-Self-Assessment (LPI-S) to survey a nursing leadership organization, the Association of California Nurse Leaders (ACNL). Anonymous responses were analyzed to identify leadership trends in age and years of professional service. On average, LPI-S metrics of leadership skills advance through years of management, RN experience, and age. The TL scores are statistically higher in most LPI-S categories for those with more than 30 years of RN or management experience. Decade-averaged LPI-S TL metrics in the ACNL survey evolve linearly throughout age before peaking in the decade from age 60 to 69 years. A similar evolution of TL metrics is seen in decades of either years of management experience or years of RN experience. Transformational leadership increased with nursing maturity particularly for LPI-S categories of "inspire a shared vision," "challenge the process," and "enable others to act." In the ACNL population studied, decade-averaged leadership metrics advanced. Leadership evolution with age in the broader RN population peaked in age bracket 60 to 69 years. The LPI-S averages declined when older than 70 years, coinciding with a shift from full-time work toward retirement and part-time employment.

  20. Vacuum Chambers for LEP sections

    CERN Multimedia

    1983-01-01

    The picture shows sections of the LEP vacuum chambers to be installed in the dipole magnets (left) and in the quadrupoles (right). The dipole chamber has three channels: the beam chamber, the pumping duct where the NEG (non-evaporabe getter) is installed and the water channel for cooling (on top in the picture). The pumping duct is connected to the beam chamber through holes in the separating wall. The thick lead lining to shield radiation can also be seen. These chambers were manufactured as extruded aluminium alloy profiles.

  1. Recommended values of the humidity correction factor k{sub n} for determining exposure in an X-ray beam with free-air chambers; Valores recomendados del factor de correccion por humedad, k{sub h} para la determinacion de la exposicion en un haz de rayos X usando camaras de paredes de aire

    Energy Technology Data Exchange (ETDEWEB)

    Los Arcos, J M; Brosed, A

    1983-07-01

    The experimental values stated by CCEMRI (Section I) concerning the humidity correction factor k{sub h} required for determining exposure in an X-ray beam with free-air chambers are commented and a method to estimate k{sub n} numerically, at any particular combination of relative humidity, pressure and temperature, la explained. A table of k{sub h}, calculated for relative humidity varying from 0% to 90%, for pressures in the range of 70 kPa to 104kPa and temperatures between 15 degree centigree and 30 degree centigree, is included. (Author) 10 refs.

  2. Levels of Rn and its daughters in houses in the northern part of China

    International Nuclear Information System (INIS)

    Zhang Yulin; Wang Gongpeng; Yu Shui; Wang Yuping; Li Weina.

    1993-01-01

    In this paper we described the levels of Rn and Rn daughters and their diurnal variation in spring and autumn in 18 typical houses in Harbin, Changchun and Jinxi. The results showed that there was no difference in levels of Rn and Rn daughters inside and outside the new and old houses in spring. The Rn concentration was 7.4∼12.5 Bq m -3 . The level of Rn daughters was 1.0-1.3 mWL. Both of them generally increased in winter and the Rn concentration was 15.1-95.1 Bq m -3 . The potential energy of Rn daughters was 4.6-21.3 mWL. The potential energy of Rn daughters in new houses were 20 and 10 times those in spring in Changchun and Harbin respectively and Rn concentrations were 10 and 4 times those in spring respectively. Rn concentrations in a few houses exceeded 200 Bq m -3 . It was lower from 12:00 to 20:00 and slightly higher from 20:00 to the next morning, and the high concentration peak can be found at morning from 4:00 to 6:00 after 24 hours continuous observation. The results was in agreement with those reported in UNSCEAR 1982 Report

  3. Review of wire chamber aging

    International Nuclear Information System (INIS)

    Va'Vra, J.

    1986-02-01

    This paper makes an overview of the wire chamber aging problems as a function of various chamber design parameters. It emphasizes the chemistry point of view and many examples are drawn from the plasma chemistry field as a guidance for a possible effort in the wire chamber field. The paper emphasizes the necessity of variable tuning, the importance of purity of the wire chamber environment, as well as it provides a practical list of presently known recommendations. In addition, several models of the wire chamber aging are qualitatively discussed. The paper is based on a summary talk given at the Wire Chamber Aging Workshop held at LBL, Berkeley on January 16-17, 1986. Presented also at Wire Chamber Conference, Vienna, February 25-28, 1986. 74 refs., 18 figs., 11 tabs

  4. Space plasma simulation chamber

    International Nuclear Information System (INIS)

    1986-01-01

    Scientific results of experiments and tests of instruments performed with the Space Plasma Simulation Chamber and its facility are reviewed in the following six categories. 1. Tests of instruments on board rockets, satellites and balloons. 2. Plasma wave experiments. 3. Measurements of plasma particles. 4. Optical measurements. 5. Plasma production. 6. Space plasms simulations. This facility has been managed under Laboratory Space Plasma Comittee since 1969 and used by scientists in cooperative programs with universities and institutes all over country. A list of publications is attached. (author)

  5. Stability of Streamer Chamber

    Science.gov (United States)

    Wada, Toshiaki; Ogawa, Masato; Takahashi, Kaoru; Sugiyama, Tsunetoshi; Kobayashi, Shigeharu; Kohno, Hirobumi

    1982-08-01

    The quality of tracks obtained from a streamer chamber is studied through the measurement of the streamer brightness. The stability of streamer tracks depends on the value of the high voltage applied and its shape. By using a single conical-type spark gap as the pulse shaper, stable brightness of the streamer tracks is attained. The data on the streamer brightness are compared with the result by Bulos et al. and it is found that the brightness is more strongly affected by field parameters than in their result.

  6. Stability of streamer chamber

    International Nuclear Information System (INIS)

    Wada, Toshiaki; Ogawa, Masato; Takahashi, Kaoru; Sugiyama, Tsunetoshi; Kobayashi, Shigeharu; Kohno, Hirobumi.

    1982-01-01

    The quality of tracks obtained from a streamer chamber is studied through the measurement of the streamer brightness. The stability of streamer tracks depends on the value of the high voltage applied and its shape. By using a single conical-type spark gap as the pulse shaper, stable brightness of the streamer tracks is attained. The data on the streamer brightness are compared with the result by Bulos et al. and it is found that the brightness is more strongly affected by field parameters than in their result. (author)

  7. Estimation of effective dose from Rn emanating from 'the minus ion' effect wallpaper

    International Nuclear Information System (INIS)

    Yoshizawa, Y.; Minowa, H.; Morita-Murase, Y.; Furuta, E.

    2006-01-01

    We have examined the wall papers which declared 'the minus ion' effect to estimate external and internal exposure dose from them. Results of gamma-ray spectrometry revealed that they contain 0.03 to 0.35 Bq·g -1 of Th-series nuclides, 208 Tl, 212 Pb, 212 Bi and 228 Ac, and U-series one, 214 Pb. Distributions of radioactive nuclides in the samples were measured using an imaging plate and a FLA-2000 (Fuji Photo Film). The radiation doses from the printed side of the wall papers were 5 to 15 times higher than that of the back side. The 222 Rn concentrations emanating from the wall papers in a sealed container of 50 liter were measured using the PICO-RAD radon detectors. One wall paper showed two to five times higher than the background value. (author)

  8. Council Chamber exhibition

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    To complete the revamp of CERN’s Council Chamber, a new exhibition is being installed just in time for the June Council meetings.   Panels will showcase highlights of CERN’s history, using some of the content prepared for the exhibitions marking 50 years of the PS, which were displayed in the main building last November. The previous photo exhibition in the Council Chamber stopped at the 1970s. To avoid the new panels becoming quickly out of date, photos are grouped together around specific infrastructures, rather than following a classic time-line. “We have put the focus on the accelerators – the world-class facilities that CERN has been offering researchers over the years, from the well-known large colliders to the lesser-known smaller facilities,” says Emma Sanders, who worked on the content. The new exhibition will be featured in a future issue of the Bulletin with photos and an interview with Fabienne Marcastel, designer of the exhibit...

  9. Cardiac chamber scintiscanning

    International Nuclear Information System (INIS)

    Goretzki, G.

    1981-01-01

    The two methods of cardiac chamber scintiscanning, i.e. 'first pass' and 'ECG-triggered' examinations, are explained and compared. Two tables indicate the most significant radiation doses of the applied radio tracers, i.e. 99m-Tc-pertechnetate and 99m-Tc-HSA, to which a patient is exposed. These averaged values are calculated from various data given in specialised literature. On the basis of data given in literature, an effective half-life of approximately 5 hours in the intravascular space was calculated for the erythrocytes labelled with technetium 99m. On this basis, the radiation doses for the patients due to 99m-Tc-labelled erythrocytes are estimated. The advantages and disadvantages of the two methods applied for cardiac chamber scintiscanning are put into contrast and compared with the advantages and disadvantages of the quantitative X-ray cardiography of the left heart. The still existing problems connected with the assessment of ECG-triggered images are discussed in detail. The author performed investigations of his own, which concerned the above-mentioned problems. (orig./MG) [de

  10. 222Rn gas metrology in Latvia

    International Nuclear Information System (INIS)

    Bogucarska, T.; Lapenas, A.

    2004-01-01

    The measurements of radon gas provides in Latvia according with the State radiation monitoring program. The national standard/reference level for the protection of employees and population from exposure to radon Latvia has been accepted. The facilities for calibration of the radon gas measurement instruments and detectors have been established on basic of the Radiation Metrology and Testing Center which is the local SSDL for Baltic Region. The radon measurement instruments and detectors calibration can be performed at the 170-4000 Bq/m 3 range. (author)

  11. Study on an In-Situ Open-Top Fumigation Chamber System for Ozone Exposure in Field%田间原位开顶式臭氧熏蒸系统研究

    Institute of Scientific and Technical Information of China (English)

    耿春梅; 杨文; 殷宝辉; 王宗爽; 刘红杰; 王效科; 王玮

    2011-01-01

    臭氧污染造成的粮食作物减产及经济损失受到普遍关注,研究植被对臭氧的响应是评估臭氧污染造成影响的重要依据.针对国内外已有开顶式熏蒸系统的缺点,改进布气管的布气孔大小和形状,以保证气室内布气的均匀性;改进风机的供气方式,采用一供三的方式以提高各平行样间的平行性;通过计算机负反馈控制和采用引流装置,以提高臭氧浓度控制和测定的准确性.在国内率先尝试在跟随环境臭氧浓度的基础上增加一定浓度的臭氧作为熏蒸气体.田间实测表明:该装置气室内臭氧浓度与设定浓度一致且分布均匀,平行样的平行性好,气室内外温度、相对湿度及光照强度衰减均达到了国内外同类装置水平,可广泛用于田间原位大气污染物对植被影响的研究.%Ozone pollution, which results in lower production and economic loss of food crops, has caused widespread concern in recent years. The study of the dose-response relationship between ozone and vegetation is an important basis for assessing the impact of ozone pollution on vegetation. In view of the shortcomings of existing instruments, this study developed an open-top chamber system. Features include: redesigning the size and shape of the holes on the gas distribution tube to ensure uniform gas distribution in the chamber; using one blower to supply gases for three chambers to ensure the same conditions in parallel chambers; and, the use of computer feedback control and a drainage device to ensure the accuracy of the ozone measurement and control. The first attempt in this study was to increase the ambient concentration of ozone as the fumigation gas to certain levels.The results from field studies showed that the ozone concentrations inside the chamber were consistent with the setting values, gases were uniformly distributed, and good consistency among the results from the three parallel chambers was found. The differences

  12. Diogene pictorial drift chamber

    International Nuclear Information System (INIS)

    Gosset, J.

    1984-01-01

    A pictorial drift chamber, called DIOGENE, has been installed at Saturne in order to study central collisions of high energy heavy ions. It has been adapted from the JADE internal detector, with two major differences to be taken into account. First, the center-of-mass of these collisions is not identical to the laboratory reference frame. Second, the energy loss and the momentum ranges of the particles to be detected are different from the ones in JADE. It was also tried to keep the cost as small as possible, hence the choice of minimum size and minimum number of sensitive wires. Moreover the wire planes are shifted from the beam axis: this trick helps very much to quickly reject the bad tracks caused by the ambiguity of measuring drift distances (positive or negative) through times (always positive)

  13. Mush Column Magma Chambers

    Science.gov (United States)

    Marsh, B. D.

    2002-12-01

    Magma chambers are a necessary concept in understanding the chemical and physical evolution of magma. The concept may well be similar to a transfer function in circuit or time series analysis. It does what needs to be done to transform source magma into eruptible magma. In gravity and geodetic interpretations the causative body is (usually of necessity) geometrically simple and of limited vertical extent; it is clearly difficult to `see' through the uppermost manifestation of the concentrated magma. The presence of plutons in the upper crust has reinforced the view that magma chambers are large pots of magma, but as in the physical representation of a transfer function, actual magma chambers are clearly distinct from virtual magma chambers. Two key features to understanding magmatic systems are that they are vertically integrated over large distances (e.g., 30-100 km), and that all local magmatic processes are controlled by solidification fronts. Heat transfer considerations show that any viable volcanic system must be supported by a vertically extensive plumbing system. Field and geophysical studies point to a common theme of an interconnected stack of sill-like structures extending to great depth. This is a magmatic Mush Column. The large-scale (10s of km) structure resembles the vertical structure inferred at large volcanic centers like Hawaii (e.g., Ryan et al.), and the fine scale (10s to 100s of m) structure is exemplified by ophiolites and deeply eroded sill complexes like the Ferrar dolerites of the McMurdo Dry Valleys, Antarctica. The local length scales of the sill reservoirs and interconnecting conduits produce a rich spectrum of crystallization environments with distinct solidification time scales. Extensive horizontal and vertical mushy walls provide conditions conducive to specific processes of differentiation from solidification front instability to sidewall porous flow and wall rock slumping. The size, strength, and time series of eruptive behavior

  14. Simulation of chamber experiments

    International Nuclear Information System (INIS)

    Ivanov, V.G.

    1981-01-01

    The description of the system of computer simulation of experiments conducted by means of track detectors with film data output is given. Considered is the principle of organization of computer model of the chamber experiment comprising the following stages: generation of events, generation of measurements, ge-- neration of scanning results, generation of distorbions, generated data calibration, filtration, events reconstruction, kinematic identification, total results tape formation, analysis of the results. Generation programs are formed as special RAM-files, where the RAM-file is the text of the program written in FORTRAN and divided into structural elements. All the programs are a ''part of the ''Hydra'' system. The system possibilities are considered on the base of the CDSC-6500 computer. The five-beam event generation, creation data structure for identification and calculation by the kinematic program take about 1s of CDC-6500 computer time [ru

  15. Nucleation in bubble chambers

    International Nuclear Information System (INIS)

    Harigel, G.G.

    1988-01-01

    Various sources and mechanisms for bubble formation in superheated liquids are discussed. Bubble chambers can be filled with a great variety of liquids, such as e.g. the cryogenic liquids hydrogen, deuterium, neon, neon/hydrogen mixtures, argon, nitrogen, argon/nitrogen mixtures, or the warm liquids propane and various Freon like Freon-13B1. The superheated state is normally achieved by a rapid movement of an expansion piston or membrane, but can also be produced by standing ultrasonic waves, shock waves, or putting liquids under tension. Bubble formation can be initiated by ionizing particles, by intense (laser) light, or on rough surfaces. The creation of embryonic bubbles is not completely understood, but the macroscopic growth and condensation can be calculated, allowing to estimate the dynamic heat load [fr

  16. Deployment and testing of a second prototype expandable surgical chamber in microgravity

    Science.gov (United States)

    Markham, Sanford M.; Rock, John A.

    1991-01-01

    During microgravity exposure, two separate expandable surgical chambers were tested. Both chambers had been modified to fit the microgravity work station without extending over the sides of the table. Both chambers were attached to a portable laminar flow generator which served two purposes: to keep the chambers expanded during use; and to provide an operative area environment free of contamination. During the tests, the chambers were placed on various parts of a total body moulage to simulate management of several types of trauma. The tests consisted of cleansing contusions, debridement of burns, and suturing of lacerations. Also, indigo carmine dye was deliberately injected into the chamber during the tests to determine the ease of cleansing the chamber walls after contamination by escaping fluids. Upon completion of the tests, the expandable surgical chambers were deflated, folded, and placed in a flattened state back into their original containers for storage and later disposal. Results are briefly discussed.

  17. Analytical FcRn affinity chromatography for functional characterization of monoclonal antibodies

    Science.gov (United States)

    Schlothauer, Tilman; Rueger, Petra; Stracke, Jan Olaf; Hertenberger, Hubert; Fingas, Felix; Kling, Lothar; Emrich, Thomas; Drabner, Georg; Seeber, Stefan; Auer, Johannes; Koch, Stefan; Papadimitriou, Apollon

    2013-01-01

    The neonatal Fc receptor (FcRn) is important for the metabolic fate of IgG antibodies in vivo. Analysis of the interaction between FcRn and IgG in vitro might provide insight into the structural and functional integrity of therapeutic IgG that may affect pharmacokinetics (PK) in vivo. We developed a standardized pH gradient FcRn affinity liquid chromatography method with conditions closely resembling the physiological mechanism of interaction between IgG and FcRn. This method allows the separation of molecular IgG isoforms, degradation products and engineered molecules based on their affinity to FcRn. Human FcRn was immobilized on the column and a linear pH gradient from pH 5.5 to 8.8 was applied. FcRn chromatography was used in comparison to surface plasmon resonance to characterize different monoclonal IgG preparations, e.g., oxidized or aggregated species. Wild-type and engineered IgGs were compared in vitro by FcRn chromatography and in vivo by PK studies in huFcRn transgenic mice. Analytical FcRn chromatography allows differentiation of IgG samples and variants by peak pattern and retention time profile. The method can distinguish: 1) IgGs with different Fabs, 2) oxidized from native IgG, 3) aggregates from monomer and 4) antibodies with mutations in the Fc part from wild-type IgGs. Changes in the FcRn chromatographic behavior of mutant IgGs relative to the wild-type IgG correlate to changes in the PK profile in the FcRn transgenic mice. These results demonstrate that FcRn affinity chromatography is a useful new method for the assessment of IgG integrity. PMID:23765230

  18. High spin states and Yrast isomers in 211Rn

    International Nuclear Information System (INIS)

    Poletti, A.R.; Dracoulis, G.D.; Fahlander, C.; Morrison, I.

    1981-01-01

    Excited states in 211 Rn with spins up to 53/2 have been identified using (HI,xn) reactions and γ-ray techniques. A shell model calculation can reproduce the ordering of the yrast sequence up to spin 41/2 - . Several yrast isomers have been identified. Enhanced E3 transitions are observed and their systematic occurrence in this region discussed. The influence of the neutron hole, and possible core excitations on the effective moment of inertia are also pointed out

  19. High spin states and yrast isomers in 211Rn

    International Nuclear Information System (INIS)

    Poletti, A.R.; Dracoulis, G.D.; Fahlander, C.; Morrison, I.

    1980-12-01

    Excited states in 211 Rn with spins up to 53/2 have been identified using (HI,xn) reactions and γ-ray techniques. A shell model calculation can reproduce the ordering of the yrast sequence up to spin 41/2. Several yrast isomers have been identified. Enhanced E3 transitions are observed and their systematic occurrence in this region discussed. The influence of the neutron hole, and possible core excitations on the effective moment of inertia are also pointed out

  20. Læringsmodstand hos børn

    DEFF Research Database (Denmark)

    Broström, Stig

    2017-01-01

    I dette kapitel beskrives dimensioner ved børns læring og med særligt fokus på Illeris’ begreb læringsmodstand. Det tages udgangspunkt i den kulturhistoriske skoles læringsteori med reference til bl.a. Vygotsky og Leontjev. Børn i såvel dagtilbud som skolen vil løbende vise modstand mod læring. D...

  1. Spilleregler i musikterapi med børn

    DEFF Research Database (Denmark)

    Holck, Ulla

    2005-01-01

    Artiklen gennemgår udvalgte eksempler på anvendelse af spilleregler i musikterapi med børneklientgrupper. Efter en kort introduktion af Priestleys syn på analytisk musikterapi med børn, præsenteres læseren således for en række caseeksempler fra faglitteraturen, der giver indblik i udformning og a...

  2. Detection system for continuous 222Rn monitoring in waters

    International Nuclear Information System (INIS)

    Holy, K.; Patschova, E.; Bosa, I.; Polaskova, A.; Hola, O.

    2001-01-01

    This contribution presents one of the high-sensitive systems of continuous radon monitoring in waters. The device can be used for the continual control of 222 Rn activity concentration in water sources, for a study of the daily and seasonal variations of radon activity concentration in water systems, for the determination of the infiltration time of surface water into the ground water and for the next untraditional applications. (authors)

  3. Priit Pärn ohjab Turus festivali / Tiit Tuumalu

    Index Scriptorium Estoniae

    Tuumalu, Tiit, 1971-

    2001-01-01

    Turu Kunstiakadeemia animatsiooniosakonda juhatav Priit Pärn lükkas eile käima I Turu animafestivali Tough Eye, kus võistleb ka kolm eesti filmi. Toimub ka Eesti päev, kus näidatakse uute tööde kõrval ka Elbert Tuganovi jt. klassikaks saanud animafilme, kaasaarvatud säilinud lõik esimesest eesti joonisfilmist "Kutsu-Juku seiklused" (1931)

  4. Peltier-based cloud chamber

    Science.gov (United States)

    Nar, Sevda Yeliz; Cakir, Altan

    2018-02-01

    Particles produced by nuclear decay, cosmic radiation and reactions can be identified through various methods. One of these methods that has been effective in the last century is the cloud chamber. The chamber makes visible cosmic particles that we are exposed to radiation per second. Diffusion cloud chamber is a kind of cloud chamber that is cooled by dry ice. This traditional model has some application difficulties. In this work, Peltier-based cloud chamber cooled by thermoelectric modules is studied. The new model provided uniformly cooled base of the chamber, moreover, it has longer lifetime than the traditional chamber in terms of observation time. This gain has reduced the costs which spent each time for cosmic particle observation. The chamber is an easy-to-use system according to traditional diffusion cloud chamber. The new model is portable, easier to make, and can be used in the nuclear physics experiments. In addition, it would be very useful to observe Muons which are the direct evidence for Lorentz contraction and time expansion predicted by Einsteins special relativity principle.

  5. A restructuring of RN1 package for MIDAS computer code

    International Nuclear Information System (INIS)

    Park, S. H.; Kim, D. H.; Kim, K. R.

    2003-01-01

    RN1 package, which is one of two fission product-related packages in MELCOR, has been restructured for the MIDAS computer code. MIDAS is being developed as an integrated severe accident analysis code with a user-friendly graphical user interface and modernized data structure. To do this, data transferring methods of current MELCOR code are modified and adopted into the RN1 package. The data structure of the current MELCOR code using FORTRAN77 causes a difficult grasping of meaning of the variables as well as waste of memory. New features of FORTRAN90 make it possible to allocate the storage dynamically and to use the user-defined data type, which lead to an efficient memory treatment and an easy understanding of the code. Restructuring of the RN1 package addressed in this paper includes module development, subroutine modification, and treats MELGEN, which generates data file, as well as MELCOR, which is processing a calculation. The verification has been done by comparing the results of the modified code with those from the existing code. As the trends are similar to each other, it hints that the same approach could be extended to the entire code package. It is expected that code restructuring will accelerate the code domestication thanks to direct understanding of each variable and easy implementation of modified or newly developed models

  6. A restructuring of RN2 package for MIDAS computer code

    International Nuclear Information System (INIS)

    Park, S. H.; Kim, D. H.

    2003-01-01

    RN2 package, which is one of two fission product-related package in MELCOR, has been restructured for the MIDAS computer code. MIDAS is being developed as an integrated severe accident analysis code with a user-friendly graphical user interface and data structure. To do this, data transferring methods of current MELCOR code are modified and adopted into the RN2 package. The data structure of the current MELCOR code using FORTRAN77 causes a difficult grasping of meaning of the variables as well as waste of memory. New features of FORTRAN90 make it possible to allocate the storage dynamically and to use the user-defined data type, which lead to an efficient memory treatment and an easy understanding of the code. Restructuring of the RN2 package addressed in this paper includes module development, subroutine modification, and treats MELGEN, which generates data file, as well as MELCOR, which is processing a calculation. The validation has been done by comparing the results of the modified code with those from the existing code. As the trends are the similar to each other, it hints that the same approach could be extended to the entire code package. It is expected that code restructuring will accelerate the code domestication thanks to direct understanding of each variable and easy implementation of modified or newly developed models

  7. Toprak Radon (222Rn Gazı Anomalilerinin ARIMA Analizi

    Directory of Open Access Journals (Sweden)

    Miraç KAMIŞLIOĞLU

    2014-12-01

    Full Text Available Özet: Zaman serileri analizi, istatistik, ekonomi, fizik ve mühendislik gibi bilim dallarında geniş uygulama alanına sahiptir. Zaman serisi analizi, değişkenlerin gelecekteki değerlerinin doğru bir şekilde tahmin edilmesi için kullanılan bir yöntemdir. Bu çalışmada, bir deprem öncüsü olarak bilinen toprak radon gazı (222Rn ölçümleri ile bir zaman serisi oluşturulmuştur. Bu veriler kullanılarak, otoregresif süreçler (ARIMA yardımıyla dinamik sistem modellemesi yapılmıştır. ARIMA; zaman serileri analizinde, zaman içerisinde rastgele gerçekleşen bir stokastik (olasılıksal sürecin veya hatalarının modellenmesidir. ARIMA modeli, temelde Box-Jenkins modeline dayanmaktadır. Box-Jenkins modeli, tek değişkenli zaman serilerinin ileriye dönük tahmin ve kontrolünde kullanılan istatistiksel tabanlı bir yöntemdir. Elde edilen sonuçlar, ARIMA modellerinin tahmin konusundaki başarısını göstermektedir. Anahtar kelimeler: Zaman Serileri Analizi, Radon Gazı (222Rn, ARIMA ARIMA Analysis of Soil Radon (222Rn Gas Anomalies Abstract: Time series analysis, has wide applications in statistics, economics, physics and engineering such disciplines. This method used for estimate correctly future values of the variables. In this study, is formed a time series with soil radon gas (222Rn measurements known as a pioneer of an earthquake. Dynamic system modelling was performed with autoregressive (ARIMA modelling process by used these measurements. ARIMA; time series analysis is modelled of the recoverable over time a random stochastic (probabilistic process or its errors. ARIMA model is based on Box-Jenkins model. Box-Jenkins model is a statistically based method which is used forward-looking forecasting and control of univariate time series. The obtained results, ARIMA model is indicating success in predict subject. Key words: Time Series Analysis, Radon Gas (222Rn, ARIMA

  8. Measurement of Rn-222 concentration in underground water in Osaka stratum group in Sennan area

    International Nuclear Information System (INIS)

    Fukui, Masami; Katsurayama, Kosuke

    1977-01-01

    The Rn-222 concentration in underground water is reported as follows, which is the result obtained when the ground inspection was carried out in the Research Reactor Institute of Kyoto University located at Kumatori area in Osaka stratum group. Underground water, at different depth, well water and rain water were taken, and the contained Rn-222 was extracted with toluene to measure by liquid scintillation technique. Rn-222 concentration in rain water was 3.5 - 8.0 pCi/l, while the concentration in well water was 130 - 250 pCi/l, and that in underground water was 240 - 313 pCi/l. The seasonal change, geographical difference and variation according to depth of Rn-222 concentration were examined. Rn-222 behavior in soil should be investigated more in detail in reference to Rn-222 dispersion, transport and equilibrium problems in soil-water system in the future. (Kobatake, H.)

  9. The little holographic bubble chambers

    International Nuclear Information System (INIS)

    Herve, A.

    1983-01-01

    The lifetime study of the charmed particles has readvanced the idea to use holography for the little fast-cycle bubble chambers. A pilot experiment has been realised in 1982 with a little bubble chamber filled up with freon-115. 40000 holograms have been recorded [fr

  10. National Ignition Facility Target Chamber

    International Nuclear Information System (INIS)

    Wavrik, R W; Cox, J R; Fleming, P J

    2000-01-01

    On June 11, 1999 the Department of Energy dedicated the single largest piece of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The ten (10) meter diameter aluminum target high vacuum chamber will serve as the working end of the largest laser in the world. The output of 192 laser beams will converge at the precise center of the chamber. The laser beams will enter the chamber in two by two arrays to illuminate 10 millimeter long gold cylinders called hohlraums enclosing 2 millimeter capsule containing deuterium, tritium and isotopes of hydrogen. The two isotopes will fuse, thereby creating temperatures and pressures resembling those found only inside stars and in detonated nuclear weapons, but on a minute scale. The NIF Project will serve as an essential facility to insure safety and reliability of our nation's nuclear arsenal as well as demonstrating inertial fusion's contribution to creating electrical power. The paper will discuss the requirements that had to be addressed during the design, fabrication and testing of the target chamber. A team from Sandia National Laboratories (SNL) and LLNL with input from industry performed the configuration and basic design of the target chamber. The method of fabrication and construction of the aluminum target chamber was devised by Pitt-Des Moines, Inc. (PDM). PDM also participated in the design of the chamber in areas such as the Target Chamber Realignment and Adjustment System, which would allow realignment of the sphere laser beams in the event of earth settlement or movement from a seismic event. During the fabrication of the target chamber the sphericity tolerances had to be addressed for the individual plates. Procedures were developed for forming, edge preparation and welding of individual plates. Construction plans were developed to allow the field construction of the target chamber to occur parallel to other NIF construction activities. This was

  11. Investigations into the long-distance atmospheric transport in Central Europe using Rn-222

    International Nuclear Information System (INIS)

    Volpp, H.J.

    1984-01-01

    An measuring network was used to determine the atmospheric Rn-222 content in Central Europe (Northern and Southern Germany, Poland). Rn-222 is to serve as tracer for the long-distance atmospheric transport in central Europe. For several areas, an average Rn-222 flux density was found. The radon source 'continent' and the soil as radon source have been taken into account. (DG) [de

  12. Rn-222 release to the environment: comparison between different granite sources

    International Nuclear Information System (INIS)

    Mamoon, M.; Kamal, S.M.

    2005-01-01

    In this work three different types of granites were studied, namely: pure granite, alkali granite and altered (hydrated) alkali granite. General radioactivity of the granites was studied along with the potential for 222 Rn emanation. The study indicated that altered alkali granite releases, relatively, the highest 222 Rn emanation to the surrounding air while alkali granite emits the more intense gamma radiation of the three granites. Hence, altered alkali granite can be used as a laboratory source for 222 Rn.

  13. The CLEO III drift chamber

    CERN Document Server

    Peterson, D; Briere, R A; Chen, G; Cronin-Hennessy, D; Csorna, S; Dickson, M; Dombrowski, S V; Ecklund, K M; Lyon, A; Marka, S; Meyer, T O; Patterson, J R; Sadoff, A; Thies, P; Thorndike, E H; Urner, D

    2002-01-01

    The CLEO group at the Cornell Electron Storage Ring has constructed and commissioned a new central drift chamber. With 9796 cells arranged in 47 layers ranging in radius from 13.2 to 79 cm, the new drift chamber has a smaller outer radius and fewer wires than the drift chamber it replaces, but allows the CLEO tracking system to have improved momentum resolution. Reduced scattering material in the chamber gas and in the inner skin separating the drift chamber from the silicon vertex detector provides a reduction of the multiple scattering component of the momentum resolution and an extension of the usable measurement length into the silicon. Momentum resolution is further improved through quality control in wire positioning and symmetry of the electric fields in the drift cells which have provided a reduction in the spatial resolution to 88 mu m (averaged over the full drift range).

  14. Absolute measurement of the activity of 222Rn using a proportional counter

    International Nuclear Information System (INIS)

    Busch, Ingo; Greupner, Heinz; Keyser, Uwe

    2002-01-01

    A measuring set-up comprising a proportional counter of calculable 222 Rn efficiency and quantifiable active volume (δ V 222 Rn efficiency is determined by computer simulation of the measured α-spectra. The procedures necessary for absolute measurements by means of the counter are described, and the suitability of the counter for absolute measurements of the 222 Rn activity is proved by experiments. Thus, a new method for the realization of the unit of activity of 222 Rn is obtained, which is independent of the unit of activity of 226 Ra

  15. Perfect simulation and moment properties for the Matérn type III process

    DEFF Research Database (Denmark)

    Møller, Jesper; Huber, Mark L.; Wolpert, Robert L.

    2010-01-01

    In a seminal work, Bertil Matérn introduced several types of processes for modeling repulsive point processes. In this paper an algorithm is presented for the perfect simulation of the Matérn III process within a bounded window in , fully accounting for edge effects. A simple upper bound on the m......In a seminal work, Bertil Matérn introduced several types of processes for modeling repulsive point processes. In this paper an algorithm is presented for the perfect simulation of the Matérn III process within a bounded window in , fully accounting for edge effects. A simple upper bound...

  16. Estimated doses related to {sup 222}Rn concentration in bunker for radiotherapy and storage of radioisotopes; Dosis estimada por concentraciones de {sup 222}Rn en bunker de radioterapia y de almacenamiento de isotopos radiactivos

    Energy Technology Data Exchange (ETDEWEB)

    Mestre, Freddy; Carrizales-Silva, Lila, E-mail: freddymest@gmail.com, E-mail: lcarriza@ivic.gob.ve [Instituto Venezolano de lnvestigaciones Cientificas, Caracas (Venezuela, Bolivarian Republic of); Sajo-Bohus, Laszlo, E-mail: sajobohus@gmail.com [Universidad Simon Bolivar, Caracas (Venezuela, Bolivarian Republic of). Laboratorio de Fisica Nuclear; Diaz, Cruz, E-mail: cruzediaZ@gmail.com [Universidad Pedagogica Experimental Libertador, Barquisimeto (Venezuela, Bolivarian Republic of). Instituto Pedagogico

    2013-07-01

    It was done a survey in radiotherapy services underground hospitals and clinics of Venezuela and Paraguay in order to estimate the concentrations of radon and its possible consequences on worker occupational exposure. Passive dosimeters were used to assess nuclear traces (NTD type CR-39 Registered-Sign ). The concentration of {sup 222}Rn is determined based on the density of traces using the calibration coefficient of 1 tr/cm{sup 2} equivalent to 0,434 Bqm{sup -3} per month of exposure. Assuming the most likely environmental conditions and the dose conversion factor equal to 9.0 x 10{sup -6} mSv h {sup -1} by Bqm{sup -3}, it was determined the average values and estimated the possible risks to health that are on average 3.0 mSva{sup -1} and 150 micro risk cancer.

  17. Measurements of {sup 222} Rn in the indoor of dwellings in the Argentinean Republic; Mediciones de {sup 222} Rn en el interior de viviendas de la Republica Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Canoba, A.; Lopez, F. [Autoridad Regulatoria Nuclear, Av. Del Libertador 8250 Ciudad de Buenos Aires (1429) (Argentina)]. e-mail: acanoba@cae.arn.gov.ar

    2006-07-01

    The {sup 222} Rn is responsible for approximately half of the dose in the population resultant of the exposure to natural radiation. Most of this dose comes from the inhalation of the offspring of the {sup 222} Rn, and these doses they are specially important in set closed. The concentration of gas radon has been measured in housings of different cities of the Argentinean Republic. The elected cities are representative of the different geologic areas of our territory. For this its were used as detecting measurement method of nuclear tracks, electret detectors and detectors based on the adsorption in activated coal. Its were analyzed a total of 2689 housings from 1983 to the date. The average value of the radon concentration obtained starting from the 2689 monitored housings was of 41.6 Bq.m{sup -3}. The effective annual dose calculated starting from this radon concentration, using a dosimetric factor of 25 {mu}Sv.a{sup -1} (Bq.m{sup -3}), which assumes an equilibrium factor of 0.4, was of 1.04 mSv. Also, with the objective of determining the dose in form more exact, during the year 2000 it put on to point a passive technique for the simultaneous measurement such the radon concentration like of the equilibrium factor. This technique uses in oneself device two detectors of nuclear traces. The average value obtained starting from 204 monitored housings by this method of simultaneous measurement turns out to be 47.1 Bq.m{sup -3} and 0.36 the equilibrium factor, being obtained a value of effective annual dose of 1.38 mSv. It fits to highlight that are very few the values above 200 Bq.m{sup -3} and in any case the 300 Bq.m{sup -3} is overcome. Analyzing the average equilibrium factor measured of 0.36, it was concluded that having assumed an equilibrium factor of 0.4 was adequate, for what for great measurement campaigns it can continue using the simple method that determines only the radon concentration. Comparing the obtained results by both methods, although the first

  18. Comparative evaluation of nose-only vs. whole-body inhalation exposures for rats

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, H C; Snipes, M B; Eidson, A F; Hobbs, C H

    1988-12-01

    Two types of rat exposure chambers, nose-only and whole-body chambers, were evaluated simultaneously for the temporal and spatial distribution of the same test aerosols within the chambers, both with and without animals present. Results indicated that both types of exposure chambers performed well, with coefficients of variation less than 10% for both temporal and spatial variations. (author)0.

  19. Comparative evaluation of nose-only vs. whole-body inhalation exposures for rats

    International Nuclear Information System (INIS)

    Yeh, H.C.; Snipes, M.B.; Eidson, A.F.; Hobbs, C.H.

    1988-01-01

    Two types of rat exposure chambers, nose-only and whole-body chambers, were evaluated simultaneously for the temporal and spatial distribution of the same test aerosols within the chambers, both with and without animals present. Results indicated that both types of exposure chambers performed well, with coefficients of variation less than 10% for both temporal and spatial variations. (author)

  20. Micro plate fission chamber development

    International Nuclear Information System (INIS)

    Wang Mei; Wen Zhongwei; Lin Jufang; Jiang Li; Liu Rong; Wang Dalun

    2014-01-01

    To conduct the measurement of neutron flux and the fission rate distribution at several position in assemblies, the micro plate fission chamber was designed and fabricated. Since the requirement of smaller volume and less structure material was taken into consideration, it is convinient, commercial and practical to use fission chamber to measure neutron flux in specific condition. In this paper, the structure of fission chamber and process of fabrication were introduced and performance test result was presented. The detection efficiency is 91.7%. (authors)

  1. Pelletron general purpose scattering chamber

    International Nuclear Information System (INIS)

    Chatterjee, A.; Kailas, S.; Kerekette, S.S.; Navin, A.; Kumar, Suresh

    1993-01-01

    A medium sized stainless steel scattering chamber has been constructed for nuclear scattering and reaction experiments at the 14UD pelletron accelerator facility. It has been so designed that several types of detectors, varying from small sized silicon surface barrier detectors to medium sized gas detectors and NaI detectors can be conveniently positioned inside the chamber for detection of charged particles. The chamber has been planned to perform the following types of experiments : angular distributions of elastically scattered particles, fission fragments and other charged particles, angular correlations for charged particles e.g. protons, alphas and fission fragments. (author). 2 figs

  2. 222Rn and decay products in outdoor and indoor environments

    International Nuclear Information System (INIS)

    Samuelsson, C.

    1984-05-01

    Radon-222 (radon) and radon daughter (RnD) measurement methodologies are analysed from both theoretical and experimental points of view. It is shown that exhalation from enclosed porous materials can be described in terms of the time-dependent diffusion theory. Deficiencies in the established accumulator method of radon exhalation measurement are shown. By the existing methods, the true free exhalation rate of thin samples may be underestimated by a factor of (1+α- 1 ), in radon-tight accumulators (α is the outer to inner volume ratio of the sample). The term back-diffusion is clarified and shown applicable to steady-state conditions only. The wire-screen technique is utilized to separate aerosol-attached and unattached RnD in a 3 m 3 radon cell. The effect of air-filtration on the RnDs is expressed as individual activity concentrations as well as in terms of effective dose equivalent rate, H. H has been reduced by a factor between 1.3 and 2.5 for the small-sized areosol particles used (surface area median less than 100 nm), at the filtration rate constant 5 h- 1 . The exact reduction value is dependent on initial aerosol load, type of filter, and dose model (Jacobi-Eisfeld and James-Birchall in this investigation). The concentration of radon and Pb-210 in the Arctic summer air averaged 75+-21 and 0.075+-0.028 mBq m- 3 , during the Swedish Ymer-80 expedition. It is shown that steadystate equilibrium models are unsuitable for estimation of the mean aerosol residence time in ocean air. A good qualitative agreement between radon-levels and the time since the air mass left larger land areas was found. The radon-222 and long-lived daughter (Pb-210, Po-210) measurements are insensitive to ship- and local contaminations. (author)

  3. An experimental chamber simulating the equilibrium between radon and its daughters in mine air

    International Nuclear Information System (INIS)

    Domanski, T.; Chruscielewski, W.; Orzechowski, W.

    1981-01-01

    An experimental chamber simulating the equilibrium between radon and its daughters in uranium mine air is described. The apparatus is useful for testing track detectors, air samplers, masks and filters and for determining occupational exposures. Increasing the humidity of the chamber air and increasing the amounts of aerosol injected both increase the values of the equilibrium factor, F. The equilibrium in the chamber air decreases after the aerosol injection but by using controlled pulse injections it was shown that the stability of F could be maintained inside the chamber for 4 hours. Results are also given for the structure of the equilibrium between radon and its daughters Qsub(i)/Q 0 in the chamber air as a function of the chamber air factor F and also for the potential α-energy of unattached products in relation to the total α-potential energy of radon daughter products in the chamber air as a function of factor F. (U.K.)

  4. Factors controlling temporal variability of near-ground atmospheric 222Rn concentration over central Europe

    Science.gov (United States)

    Zimnoch, M.; Wach, P.; Chmura, L.; Gorczyca, Z.; Rozanski, K.; Godlowska, J.; Mazur, J.; Kozak, K.; Jeričević, A.

    2014-09-01

    Concentration of radon (222Rn) in the near-ground atmosphere has been measured quasi-continuously from January 2005 to December 2009 at two continental sites in Europe: Heidelberg (south-west Germany) and Krakow (southern Poland). The atmosphere was sampled at ca. 30 and 20 m above the local ground. Both stations were equipped with identical instruments. Regular observations of 222Rn were supplemented by measurements of surface fluxes of this gas in the Krakow urban area, using two different approaches. The measured concentrations of 222Rn varied at both sites in a wide range, from less than 2.0 Bq m-3 to approximately 40 Bq m-3 in Krakow and 35 Bq m-3 in Heidelberg. The mean 222Rn content in Krakow, when averaged over the entire observation period, was 30% higher than in Heidelberg (5.86 ± 0.09 and 4.50 ± 0.07 Bq m-3, respectively). Distinct seasonality of 222Rn signal is visible in the obtained time series of 222Rn concentration, with higher values recorded generally during late summer and autumn. The surface 222Rn fluxes measured in Krakow also revealed a distinct seasonality, with broad maximum observed during summer and early autumn and minimum during the winter. When averaged over a 5-year observation period, the night-time surface 222Rn flux was equal to 46.8 ± 2.4 Bq m-2 h-1. Although the atmospheric 222Rn levels at Heidelberg and Krakow appeared to be controlled primarily by local factors, it was possible to evaluate the "continental effect" in atmospheric 222Rn content between both sites, related to gradual build-up of 222Rn concentration in the air masses travelling between Heidelberg and Krakow. The mean value of this build-up was equal to 0.78 ± 0.12 Bq m-3. The measured minimum 222Rn concentrations at both sites and the difference between them was interpreted in the framework of a simple box model coupled with HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) analysis of air mass trajectories. The best fit of experimental data was

  5. Integrative genomic analysis of interleukin-36RN and its prognostic value in cancer.

    Science.gov (United States)

    Lv, Zhilei; Fan, Jinshuo; Zhang, Xiuxiu; Huang, Qi; Han, Jieli; Wu, Feng; Hu, Guorong; Guo, Mengfei; Jin, Yang

    2016-02-01

    Interleukin (IL)-36RN, previously known as IL1-F5 and IL-1δ, shares a 360-kb region of chromosome 2q13 with members of IL-1 systems. IL-36RN encodes an anti-inflammatory cytokine, IL-36 receptor antagonist (IL-36Ra). In spite of IL-36Ra showing the highest homology to IL-1 receptor (IL-1R) antagonist, it differs from the latter in aspects including its binding to IL-lRrp2 but not to IL-1R1. IL-36RN is mainly expressed in epithelial cells and has important roles in inflammatory diseases. In the present study, IL-36RN was identified in the genomes of 27 species, including human, chimpanzee, mouse, horse and dolphin. Human IL-36RN was mainly expressed in the eye, head and neck, fetal heart, lung, testis, cervix and placenta; furthermore, it was highly expressed in bladder and parathyroid tumors. Furthermore, a total of 30 single nucleotide polymorphisms causing missense mutations were determined, which are considered to be the causes of various diseases, such as generalized pustular psoriasis. In addition, the link between IL-36RN and the prognosis of certain cancer types was revealed through meta-analysis. Tumor-associated transcriptional factors c-Fos, activator protein-1, c-Jun and nuclear factor κB were found to bind to the upstream region in the IL-36RN gene. This may indicate that IL-36RN is involved in tumorigenesis and tumor progression through the regulation of tumor-associated transcriptional factors. The present study identified IL-36RN in various species and investigated the associations between IL-36RN and cancer prognosis, which would determine whether IL-36RN drove the evolution of the various species with regard to tumorigenesis.

  6. 222Rn in the Antarctic Peninsula during 1986

    International Nuclear Information System (INIS)

    Pereira, E.B.; Setzer, A.W.; Cavalcanti, I.F.A.

    1988-01-01

    222 Rn was continuously measured at the Brazilian Antarctic Station (62 0 S, 58 0 W) during the year of 1986. Baseline radon concentration averaged 0.02 Bq.m -3 with surges peaking 0.4 Bq.m -3 . The data exhibited a characteristic periodicity of about 25 days and a strong positive association with short term fluctuations of atmospheric temperature. No seasonal variations of radon were observed. Interpretation of the radon surges with reference to synoptic charts and weather satellite pictures showed that the continental influence of radon at the Antarctic Peninsula is very small and comes only from the tip of the South American cone. (author)

  7. Vitali systems in R^n with irregular sets

    DEFF Research Database (Denmark)

    Mejlbro, Leif; Topsøe, Flemming

    1996-01-01

    Vitali type theorems are results stating that out of a given family of sets one can select pairwise disjoint sets which fill out a "large" region. Usually one works with "regular" sets such as balls. We shall establish results with sets of a more complicated geometrical structure, e.g., Cantor......-like sets are allowed. The results are related to a generalisation of the classical notion of a differentiation basis.l They concern real n-space R^n and Lebesgue measure....

  8. Oplæsning for børn

    DEFF Research Database (Denmark)

    Jensen, Mette Nygaard

    2004-01-01

    Mål og Mæle 27(4):16-19. 2004 Kort beskrivelse: Om dialogisk oplæsning, børns ordforråd og sproglige opmærksomhed Abstract: Det er på mange måder godt at læse op for børn. Men hvad skal der til i oplæsningen, for at børnene lærer nye ord? I denne artikel beskrives et projekt, der har vist, at bør...

  9. Research management: the case of RN4CAST.

    Science.gov (United States)

    Zikos, Dimitrios; Mantas, John

    2011-01-01

    Successful research management requires multifunctional, equal teamwork and efficient coordination, aiming to increase the impact of the research outcomes. Aim of this paper is to present the strategies that have been followed to successfully manage the RN4CAST study, one of the largest multi country research projects ever conducted. The paper focuses on the core research strategies rather than on the administrative management activities also required for the success of this case report. Management of a multi-country nursing survey requires the use of common data collection tools, applicable to every context, research protocols supporting the scope of the research, data models for multi-country analyses and global dissemination strategies.

  10. Estimates concentrations in bottled 222Rn of the dose due to mineral waters in Iran

    International Nuclear Information System (INIS)

    Assadi, M. R.; Esmaealnejad, M.; Rahmatinejad, Z.

    2006-01-01

    Radon is a radionuclide that has the main role in exposure. Radon in water causes exposure in whole body but the largest dose being received by the stomach, as EPA (Environmental Protection Agency) estimates that radon in drinking water causes about 168 cancer deaths per year: 89 p ercent f rom lung cancer caused by breathing released to the indoor air from water and 11 p ercent f rom stomach cancer caused by consuming water containing radon. Now days the consumption of bottled mineral waters has become very popular. As is known, some kinds of mineral waters contain naturally occurring radionuclides in higher concentration than the usual drinking (tap) water. Surveys and reports on radon in most surface waters is low compared with radon level in groundwater and mineral water. In our work, the concentration of Rn(222) was determined in some bottled mineral waters available in Iran , and in next step the dose contribution ; due to ingestion ; for 1 l d -1 bottled mineral water consumption.

  11. Proton beam monitor chamber calibration

    International Nuclear Information System (INIS)

    Gomà, C; Meer, D; Safai, S; Lorentini, S

    2014-01-01

    The first goal of this paper is to clarify the reference conditions for the reference dosimetry of clinical proton beams. A clear distinction is made between proton beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that should be calibrated with a (pseudo-)monoenergetic proton beam. For the latter, this paper also compares two independent dosimetry techniques to calibrate the beam monitor chambers: absolute dosimetry (of the number of protons exiting the nozzle) with a Faraday cup and reference dosimetry (i.e. determination of the absorbed dose to water under IAEA TRS-398 reference conditions) with an ionization chamber. To compare the two techniques, Monte Carlo simulations were performed to convert dose-to-water to proton fluence. A good agreement was found between the Faraday cup technique and the reference dosimetry with a plane-parallel ionization chamber. The differences—of the order of 3%—were found to be within the uncertainty of the comparison. For cylindrical ionization chambers, however, the agreement was only possible when positioning the effective point of measurement of the chamber at the reference measurement depth—i.e. not complying with IAEA TRS-398 recommendations. In conclusion, for cylindrical ionization chambers, IAEA TRS-398 reference conditions for monoenergetic proton beams led to a systematic error in the determination of the absorbed dose to water, especially relevant for low-energy proton beams. To overcome this problem, the effective point of measurement of cylindrical ionization chambers should be taken into account when positioning the reference point of the chamber. Within the current IAEA TRS-398 recommendations, it seems advisable to use plane-parallel ionization chambers—rather than cylindrical chambers—for the reference dosimetry of pseudo-monoenergetic proton beams. (paper)

  12. A small flat fission chamber

    International Nuclear Information System (INIS)

    Li Yijun; Wang Dalun; Chen Suhe

    1999-01-01

    With fission materials of depleted uranium, natural uranium, enriched uranium, 239 Pu, and 237 Np, the authors have designed and made a series of small flat fission chamber. The authors narrated the construction of the fission chamber and its technological process of manufacture, and furthermore, the authors have measured and discussed the follow correct factor, self-absorption, boundary effect, threshold loss factor, bottom scatter and or so

  13. Advances on fission chamber modelling

    International Nuclear Information System (INIS)

    Filliatre, Philippe; Jammes, Christian; Geslot, Benoit; Veenhof, Rob

    2013-06-01

    In-vessel, online neutron flux measurements are routinely performed in mock-up and material testing reactors by fission chambers. Those measurements have a wide range of applications, including characterization of experimental conditions, reactor monitoring and safety. Depending on the application, detectors may experience a wide range of constraints, of several magnitudes, in term of neutron flux, gamma-ray flux, temperature. Hence, designing a specific fission chamber and measuring chain for a given application is a demanding task. It can be achieved by a combination of experimental feedback and simulating tools, the latter being based on a comprehensive understanding of the underlying physics. A computation route that simulates fission chambers, named CHESTER, is presented. The retrieved quantities of interest are the neutron-induced charge spectrum, the electronic and ionic pulses, the mean current and variance, the power spectrum. It relies on the GARFIELD suite, originally developed for drift chambers, and makes use of the MAGBOLTZ code to assess the drift parameters of electrons within the filling gas, and the SRIM code to evaluate the stopping range of fission products. The effect of the gamma flux is also estimated. Computations made with several fission chambers exemplify the possibilities of the route. A good qualitative agreement is obtained when comparing the results with the experimental data available to date. In a near future, a comprehensive experimental programme will be undertaken to qualify the route using the known neutron sources, mock-up reactors and wide choice of fission chambers, with a stress on the predictiveness of the Campbelling mode. Depending on the results, a refinement of the modelling and an effort on the accuracy of input data are also to be considered. CHESTER will then make it possible to predict the overall sensitivity of a chamber, and to optimize the design for a given application. Another benefit will be to increase the

  14. BEBC Big European Bubble Chamber

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    A view of the dismantling of the magnet of BEBC, the 3.7 m European Bubble Chamber : iron magnetic shielding ; lower and upper parts of the vacuum enclosure of the magnet; turbo-molecular vacuum pumps for the "fish-eye" windows; the two superconducting coils; a handling platform; the two cryostats suspended from the bar of the travelling crane which has a 170 ton carrying capacity. The chamber proper, not dismantled, is inside the shielding.

  15. The OPAL vertex drift chamber

    International Nuclear Information System (INIS)

    Carter, J.R.; Elcombe, P.A.; Hill, J.C.; Roach, C.M.; Armitage, J.C.; Carnegie, R.K.; Estabrooks, P.; Hemingway, R.; Karlen, D.; McPherson, A.; Pinfold, J.; Roney, J.M.; Routenburg, P.; Waterhouse, J.; Hargrove, C.K.; Klem, D.; Oakham, F.G.; Carter, A.A.; Jones, R.W.L.; Lasota, M.M.B.; Lloyd, S.L.; Pritchard, T.W.; Wyatt, T.R.

    1990-01-01

    A high precision vertex drift chamber has been installed in the OPAL experiment at LEP. The design of the chamber and the associated readout electronics is described. The performance of the system has been studied using cosmic ray muons and the results of these studies are presented. A space resolution of 50 μm in the drift direction is obtained using the OPAL central detector gas mixture at 4 bar. (orig.)

  16. Development of a PIN diode based on-line measurement system for Radon (222Rn) and Thoron (220Rn) in environment

    International Nuclear Information System (INIS)

    Ashokkumar, P.; Chaudhury, Probal; Sumesh, C.G.; Sahoo, B.K.; Gaware, J.J.; Mayya, Y.S.

    2014-01-01

    Radon, thoron and their progenies are universally present in outdoor air, and can reach higher levels in indoor air due to poor ventilation. Several instruments have been developed for accurate measurement of radon and thoron in the environment. Semiconductor detector based system employing spectroscopic method has been proved to be the best among them. A PIN diode based electrostatic collection type online real-time instrument has been developed in Bhabha Atomic Research Centre for simultaneous measurement of radon and thoron in an environment while both 222 Rn and 220 Rn are present. This system can be used for determination of radon and thoron concentrations at residence or workplace. Furthermore, since the 222 Rn and 220 Rn are differentiated from each other through spectroscopy, this monitor can be used even in a mixed radon/thoron environment

  17. Environmental impact of CO2, Rn, Hg degassing from the rupture zones produced by Wenchuan M s 8.0 earthquake in western Sichuan, China.

    Science.gov (United States)

    Zhou, Xiaocheng; Chen, Zhi; Cui, Yueju

    2016-10-01

    The concentrations and flux of CO2, (222)Radon (Rn), and gaseous elemental mercury (Hg) in soil gas were investigated based on the field measurements in June 2010 at ten sites along the seismic rupture zones produced by the May 12, 2008, Wenchuan M s 8.0 earthquake in order to assess the environmental impact of degassing of CO2, Rn and Hg. Soil gas concentrations of 344 sampling points were obtained. Seventy measurements of CO2, Rn and Hg flux by the static accumulation chamber method were performed. The results of risk assessment of CO2, Rn and Hg concentration in soil gas showed that (1) the concentration of CO2 in the epicenter of Wenchuan M s 8.0 earthquake and north end of seismic ruptures had low risk of asphyxia; (2) the concentrations of Rn in the north segment of seismic ruptures had high levels of radon, Maximum was up to level 4, according to Chinese code (GB 50325-2001); (3) the average geoaccumulation index I geo of soil Hg denoted the lack of soil contamination, and maximum values classified the soil gas as moderately to strongly polluted in the epicenter. The investigation of soil gas CO2, Rn and Hg degassing rate indicated that (1) the CO2 in soil gas was characterized by a mean [Formula: see text] of -20.4 ‰ and by a mean CO2 flux of 88.1 g m(-2) day(-1), which were in the range of the typical values for biologic CO2 degassing. The maximum of soil CO2 flux reached values of 399 g m(-2) day(-1) in the epicenter; (2) the soil Rn had higher exhalation in the north segment of seismic ruptures, the maximum reached value of 1976 m Bq m(-2) s(-1); (3) the soil Hg flux was lower, ranging from -2.5 to 18.7 n g m(-2) h(-1) and increased from south to north. The mean flux over the all profiles was 4.2 n g m(-2) h(-1). The total output of CO2 and Hg degassing estimated along seismic ruptures for a survey area of 18.17 km(2) were approximately 0.57 Mt year(-1) and 688.19 g year(-1). It is recommended that land-use planners should

  18. SMOG CHAMBERS: A TOOL TO EXAMINE EFFECTS OF PHOTOCHEMICALLY AGED AIR POLLUTANTS ON BIOLOGICAL SYSTEMS

    Science.gov (United States)

    Irradiative exposure chambers or 'Smog chambers' have been used at the University of North Carolina for over 30 years to study photochemically active mixtures of volatile organic compounds and their transformation products (a significant sub-set of Hazardous Air Pollutants, HAPs)...

  19. Measurement and three dimensional reconstruction of particle tracks in emulsion chambers

    International Nuclear Information System (INIS)

    Persson, S.

    1989-01-01

    A software package for making fast and accurate measurements of particle tracks in emulsion chambers is described. In a chamber, which is designed for high particle multiplicities, the emulsion layers are interspersed with air and placed perpendicular to the beam direction during exposure. (orig.)

  20. PEP quark search proportional chambers

    Energy Technology Data Exchange (ETDEWEB)

    Parker, S I; Harris, F; Karliner, I; Yount, D [Hawaii Univ., Honolulu (USA); Ely, R; Hamilton, R; Pun, T [California Univ., Berkeley (USA). Lawrence Berkeley Lab.; Guryn, W; Miller, D; Fries, R [Northwestern Univ., Evanston, IL (USA)

    1981-04-01

    Proportional chambers are used in the PEP Free Quark Search to identify and remove possible background sources such as particles traversing the edges of counters, to permit geometric corrections to the dE/dx and TOF information from the scintillator and Cerenkov counters, and to look for possible high cross section quarks. The present beam pipe has a thickness of 0.007 interaction lengths (lambdasub(i)) and is followed in both arms each with 45/sup 0/ <= theta <= 135/sup 0/, ..delta..phi=90/sup 0/ by 5 proportional chambers, each 0.0008 lambdasub(i) thick with 32 channels of pulse height readout, and by 3 thin scintillator planes, each 0.003 lambdasub(i) thick. Following this thin front end, each arm of the detector has 8 layers of scintillator (one with scintillating light pipes) interspersed with 4 proportional chambers and a layer of lucite Cerenkov counters. Both the calculated ion statistics and measurements using He-CH/sub 4/ gas in a test chamber indicate that the chamber efficiencies should be >98% for q=1/3. The Landau spread measured in the test was equal to that observed for normal q=1 traversals. One scintillator plane and thin chamber in each arm will have an extra set of ADC's with a wide gate bracketing the normal one so timing errors and tails of earlier pulses should not produce fake quarks.

  1. Average daily and annual courses of 222Rn concentration in some natural medium

    International Nuclear Information System (INIS)

    Holy, K.; Bohm, R.; Polaskova, A.; Stelina, J.; Sykora, I.; Hola, O.

    1996-01-01

    Simultaneous measurements of the 222 Rn concentration in the outdoor atmosphere of Bratislava and in the soil air over one year period have been made. Daily and seasonal variations of the 222 Rn concentration in both media were found. Some attributes of these variations as well as methods of measurements are presented in this work. (author). 17 refs., 6 figs

  2. High-spin isomer in 211Rn, and the shape of the yrast line

    International Nuclear Information System (INIS)

    Dracoulis, G.D.; Fahlander, C.; Poletti, A.R.

    1981-08-01

    High spin yrast states in 211 Rn have been identified. A 61/2 - , 380 ns isomer found at 8856 keV is characterised as a core-excited configuration. The average shape of the yrast line shows a smooth behaviour with spin, in contrast to its neighbour 212 Rn. This difference is attributed to the presence of the neutron hole

  3. Predictors of Success and Failure for ADN Students on the NCLEX-RN

    Science.gov (United States)

    Benefiel, Diane

    2011-01-01

    The purpose of this study was to: 1) analyze the relationship of preprogram and nursing program variables on National Council Licensure Examination for Registered Nurses (NCLEX-RN) success and failure, and 2) develop a model to predict success and failure on the NCLEX-RN. The convenience sample was comprised of 245 spring, summer, and fall midterm…

  4. Forskning i musikterapi - børn med en Autisme Spektrum Forstyrrelse

    DEFF Research Database (Denmark)

    Holck, Ulla

    2011-01-01

    Der er forskningsmæssig evidens for, at musikterapi med børn med en autisme spektrum forstyrrelse (ASF) har en signifikant effekt. Cochrane reviews påviser, at musikterapi fremmer verbal og navnlig nonverbal kommunikation hos børn med ASF. En RCT-undersøgelse viser endvidere en signifikant effekt...

  5. The Transition Experiences of Graduates of a Synchronous Online LPN to RN Program

    Science.gov (United States)

    Hoag, Debra K.

    2016-01-01

    This qualitative case study included a review of the nursing shortage, nursing education, contemporary learners, the LPN and RN, the future of nursing education, online education, and transitions experiences. These topics defined this study by providing the underpinnings to understand the LPN to RN journey. According to the American Association of…

  6. Eksklusion og inklusion af minoritetsdanske børn i dagtilbud

    DEFF Research Database (Denmark)

    Tireli, Üzeyir

    2014-01-01

    Med udgangspunkt i minoritetsdanske børn som case, beskæftiger artiklen sig med inklusions- og eksklusionsprocesserne i dagtilbud. Den diskursive konstruktion af "os" og "dem" synes at være en af hovedårsagerne til eksklusion af disse børn. Forfatteren kommer med bud på og ideer til hvordan disse...

  7. Radioelement (U,Th,Rn) concentrations in Norwegian bedrock groundwaters

    International Nuclear Information System (INIS)

    Banks, D.; Roeyset, O.; Strand, T.; Skarphagen, H.

    1993-12-01

    Samples of groundwater from bedrock boreholes in three Norwegian geological provinces have been analysed for content of 222 Rn, U and Th. Median values of 290 Bq/l, 7.6 μg/l and 0.02 μg/l were obtained for Rn, U and Th, respectively, while maximum values were 8500 Bq/l, 170 μg/l and 2.2 μg/l. Commonly suggested drinking water limits range from 8 to 1000 Bq/l for radon and 14 to 160 μg/l for uranium. Radioelement content was closely related to lithology, the lowest concentrations being derived from the largely Caledonian rocks of the Troendelag area, and the highest from the Precambrian Iddefjord Granite of South East Norway where median values of 2500 Bq/l, 15 μg/l and 0.38 μg/l, respectively, were obtained. The Iddefjord Granite is not believed to be unique in Norway yielding high dissolved radionuclide contents in groundwaters, and several other granitic aquifers warrant further investigation in this respect. 63 refs., 13 figs., 8 tabs

  8. Observation and modeling of 222Rn daughters in liquid nitrogen

    International Nuclear Information System (INIS)

    Frodyma, N.; Pelczar, K.; Wójcik, M.

    2014-01-01

    The results of alpha spectrometric measurements of the activity of 222 Rn daughters dissolved in liquefied nitrogen are presented. A direct detection method of ionized alpha-emitters from the 222 Rn decay chain ( 214 Po and 218 Po) in a cryogenic liquid in the presence of an external electric field is shown. Properties of the radioactive ions are derived from a proposed model of ion production and transport in the cryogenic liquid. Ionic life-time of the ions was found to be on the order of 10 s in liquid nitrogen (4.0 purity class). The presence of positive and negative ions was observed. - Highlights: • A direct detection method of the alpha-emitters in a cryogenic liquid is shown. • We examine electrostatic drifting of the radioactive ions in liquid nitrogen. • The ions belong to the Radon-222 decay chain; Radon-222 is dissolved in the liquid. • The model of the ions production and behaviour in the liquid is proposed. • The ion production significantly depends on the nuclear decay type (alpha or beta)

  9. Une vie traversée : Unica Zürn

    Directory of Open Access Journals (Sweden)

    Jeannine Paque

    2017-11-01

    Full Text Available Born in 1916 in Berlin, Unica Zürn committed suicide in Paris in 1970. During the last twenty years of her life, this artist, painter, and sentimental companion of Hans Bellmer, fought against schizophrenia. She spent many periods in psychiatric hospitals and has described her mental illness, her remissions from this illness and the psychiatric universe in El Hombre-Jazmín. This is an unusual autobiography, narrated in third person and in the present historic, and represents a direct and perturbed testimony of a lucid nature about her experiences. The book includes anagrams that sh developed over a long period of time. Née en 1916 à Berlin, Unica Zürn se suicide à Paris en 1970. Durant les quelque vingt dernières années de sa vie, cette artiste, peintre et écrivain, compagne de Hans Bellmer, luttera contre la schizophrénie. Elle fera de nombreux séjours en hôpital psychiatrique et décrira tant sa maladie mentale et ses rémissions que l’univers psychiatrique dans un texte majeur, L’Homme-Jasmin. Une étrange autobiographie à la troisième personne et au présent, troublant témoignage direct et lucide sur un vécu perturbé, qui inclut les textes anagrammatiques auxquels elle s’est longuement adonnée.

  10. Qualidade de mamão 'Formosa' produzido no RN e armazenado sob atmosfera passiva Quality of 'Formosa' papaya produced at RN and storage under passive atmosphere

    Directory of Open Access Journals (Sweden)

    Paula Lidiane de Oliveira Fernandes

    2010-12-01

    Full Text Available Este trabalho teve por objetivo avaliar o efeito da cera de carnaúba (Primax Wax e filme plástico de polietileno de baixa densidade "X-tend" sobre a vida útil pós-colheita de mamão 'Formosa' (Tainung 1 produzido em Baraúna - RN. O experimento foi conduzido no laboratório de Pós-colheita da Universidade Federal Rural do Semi-Árido (UFERSA. Utilizou-se um esquema fatorial 3 x 6 com 3 repetições de três frutos por parcela, constituindo na combinação de 3 tipos de atmosferas (cera, filme de polietileno e controle com 6 tempos de armazenamento (0; 7; 14; 21; 28; 35. Os frutos dos distintos tratamentos foram armazenados em câmaras frias a 10 ± 2 ºC e UR 90 ± 5%, analisados em intervalos de sete dias. As características avaliadas foram: aparência externa, perda de massa, firmeza da polpa, sólidos solúveis, acidez titulável e vitamina C. Constatou-se ser o filme plástico o mais eficiente em manter a qualidade externa e reduzir a perda de massa dos frutos. A cera de carnaúba, na concentração utilizada, mostrou eficiência relativa na conservação de mamão quando comparada ao filme plástico. A vida útil pós-colheita dos frutos mantidos sob atmosfera modificada foi de 35 dias e do controle apenas 28 dias.The aim of this work was to evaluate the effect of carnauba wax (Primax Wax and low-density polyethylene film "X-tend" on shelf life of 'Formosa' papaya fruits produced in Baraúna, RN. The experiment was carried out in the Postharvest Laboratory of the Universidade Federal Rural do Semi-Árido (UFERSA. A 3 x 6 factorial scheme with three replications of three fruits per plot in a completely randomized design was used. The treatments consisted of the combination of three types of atmosphere (wax, polyethylene film and control with six storage times (0; 7; 14; 21; 28 and 35. The fruits of these treatments were stored in cold chamber at 10 ± 2 ºC and RH 90 ± 5%, and analyzed in 7 days intervals. The evaluated traits were

  11. Lifetime survivability of contaminated target-chamber optics

    International Nuclear Information System (INIS)

    Rainer, F.; Anderson, A.; Burnham, A.; Milam, D.; Turner, R.

    1996-11-01

    Target chambers used for Inertial Confinement Fusion (ICF) expose laser optics to a very hostile environment, not only from high-fluence laser irradiation but also x-ray irradiation and particulate debris from targets and chamber wall materials. Expendable debris shields provide the first line of defense to more costly optics upstream in the laser beam path to contaminants generated within the target chamber. However, the replacement of a large number of debris shields is also an expensive proposition so that extending their usable lifetime within the chamber is important. We have conducted tests to show that optics can both be cleaned and damaged by laser irradiation at 355 nm after being contaminated with potential chamber-wall materials such as B 4 C and Al 2 O 3 . Such optics can survive from one to hundreds of laser shots, depending on degree of contamination and laser fluence levels. Similarly, we have studied the survivability of optics that have been exposed to direct contamination from representative target materials irradiated in the target chamber. We have also studied the effects on optics that were not directly exposed to targets, yet received secondary exposure from the above directly-exposed samples

  12. Extraction and purification of {sup 227}Ac and development of solid {sup 219}Rn source

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Quan; Qiu, Shoukang; Xiao, Detao; Zhou, Yaohui; An, Xiaogang [University of South China, Hengyang (China). Radon Key Laboratory of Hunan Province/School of Nuclear Science and Technology

    2014-04-01

    The method of {sup 227}Ac extraction and purification from high-grade uranium ore and the test results of solid {sup 219}Rn source made from {sup 227}Ac are reported in this paper. With five years of follow-up monitoring, radiochemical purity of {sup 227}Ac and the emanation power of solid {sup 219}Rn source has been checked by emanation method and γ-spectrometry, the results showed that {sup 228}Th, {sup 231}Pa and {sup 226}Ra have been effectively removed and the emanation power of {sup 219}Rn source is about 80%. The long-term test results also showed that the {sup 219}Rn emanation rate remains stable in a wide air humidity range (40% ∝ 90%). Though the {sup 219}Rn source has not been accurately calibrated yet, it has been applied in the research for delay coincidence measurement of {sup 223}Ra. (orig.)

  13. The neonatal Fc receptor, FcRn, as a target for drug delivery and therapy.

    Science.gov (United States)

    Sockolosky, Jonathan T; Szoka, Francis C

    2015-08-30

    Immunoglobulin G (IgG)-based drugs are arguably the most successful class of protein therapeutics due in part to their remarkably long blood circulation. This arises from IgG interaction with the neonatal Fc receptor, FcRn. FcRn is the central regulator of IgG and albumin homeostasis throughout life and is increasingly being recognized as an important player in autoimmune disease, mucosal immunity, and tumor immune surveillance. Various engineering approaches that hijack or disrupt the FcRn-mediated transport pathway have been devised to develop long-lasting and non-invasive protein therapeutics, protein subunit vaccines, and therapeutics for treatment of autoimmune and infectious disease. In this review, we highlight the diverse biological functions of FcRn, emerging therapeutic opportunities, as well as the associated challenges of targeting FcRn for drug delivery and disease therapy. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Characterization of 222Rn entry into a basement structure surrounded by low permeability soil

    International Nuclear Information System (INIS)

    Ward, D.C.

    1992-01-01

    An experimental facility has been developed to monitor the entry rate and concentration of 222 Rn in two basement type structures surrounded by soil having a permeability on the order of 1- -12 m 2 . A data acquisition system recorded environmental conditions outside and inside the structures, including basement air exchange rates, every 15 min. Indoor 222 Rn concentrations ranged from 400 to 1400 Bq m -3 . The observed 222 Rn entry rate is highly variable and has two primary components; a constant input rate caused by diffusion of 222 Rn through the concrete walls and floor, and a variable rate that depends upon indoor-soil pressure differentials of only a few pascals. Pressure differentials are dependent upon wind speed and wind direction. Stack effect was not significant. During a two week period, with relatively calm winds, diffusion through the concrete walls and floor plus the floor-wall joint accounted for more than 80% of the total 222 Rn entry

  15. Regularity of random attractors for fractional stochastic reaction-diffusion equations on Rn

    Science.gov (United States)

    Gu, Anhui; Li, Dingshi; Wang, Bixiang; Yang, Han

    2018-06-01

    We investigate the regularity of random attractors for the non-autonomous non-local fractional stochastic reaction-diffusion equations in Hs (Rn) with s ∈ (0 , 1). We prove the existence and uniqueness of the tempered random attractor that is compact in Hs (Rn) and attracts all tempered random subsets of L2 (Rn) with respect to the norm of Hs (Rn). The main difficulty is to show the pullback asymptotic compactness of solutions in Hs (Rn) due to the noncompactness of Sobolev embeddings on unbounded domains and the almost sure nondifferentiability of the sample paths of the Wiener process. We establish such compactness by the ideas of uniform tail-estimates and the spectral decomposition of solutions in bounded domains.

  16. Project, construction and calibration of parallel plate ionization chambers for x-radiation

    International Nuclear Information System (INIS)

    Albuquerque, M.P.P.

    1989-01-01

    Two pairs of parallel-plate ionization chambers were projected and constructed. In each pair one of the chambers has a collecting electrode and a guard ring made of graphite and the other, of aluminium. The difference between both pairs is that in only one case screws were used to fix the chamber components. The chambers are made of Lucite with aluminized Mylar entrance windows; they have circular form and are unsealed. All chamber components are easily available. The main chamber characteristics were determined, applying the tests of current leakage, repetitively and long term stability. The energy and angular dependence, and the polarity effect were also studied, obtaining the saturation curves and determining the build-up effect for gamma radiation detection. The chambers were calibrated with low and intermediate energy X-radiation, gamma radiation of sup(60)Co an sup(137)Cs, and beta radiation of sup(90)Sr + sup(90)Y. The obtained results show the viability of utilization of these chambers in radiation dosimetry and the results were compared with those of imported commercial ionization chambers of the secondary standard type. The great difference between the energy dependence of the chambers according to the collecting electrode material, allowed the formation of a Tandem system (constituted by a chamber pair A, C), for the determination of the effective energy and the exposure rate in air of unknown X-radiation fields, in the case of low intermediate energy ranges. (author)

  17. Directional muon jet chamber for a muon collider (Groovy Chamber)

    International Nuclear Information System (INIS)

    Atac, M.

    1996-10-01

    A directional jet drift chamber with PAD readout is proposed here which can select vertex originated muons within a given time window and eliminate those muons which primarily originate upstream, using only a PAD readout. Drift time provides the Z-coordinate, and the center of gravity of charge distribution provides the r-ψ coordinates. Directionality at the trigger level is obtained by the timing measurement from the PAD hits within a given time window. Because of the long drift time between the bunch crossings, a muon collider enables one to choose a drift distance in the drift chamber as long as 50 cm. This is an important factor in reducing cost of drift chambers which have to cover relatively large areas

  18. Seasonal variations of radon and the radiation exposure levels in Nerja cave, Spain

    International Nuclear Information System (INIS)

    Duenas, C.; Fernandez, M.C.; Canete, S.; Perez, M.; Gordo, E.

    2011-01-01

    222 Rn concentrations in the air in Nerja cave (Spain) (3 o 52'35''W 36 o 43'50''N) were measured by continuous monitoring using Alpha-Guard, Genitron instrument equipment. The 222 Rn measurements were carried out for a complete annual cycle in the different halls: Vestibule hall from July 2003 to June 2004, Ballet hall from July 2004 to June 2005 and Mirador hall from July 2005 to June 2006. Starting from the entrance of the cave we successively find the Vestibule hall, the Ballet hall and the Mirador hall. The range of 222 Rn levels were of 8-627 Bq m -3 for the Vestibule hall, 28-575 Bq m -3 for the Ballet hall and 38-578 Bq m -3 for the Mirador. The aim of this study was to detect seasonal variation patterns of 222 Rn concentrations. The seasonal variations of 222 Rn concentrations are discussed in relation to various meteorological factors measured inside and outside the cave. The radiation exposure levels for workers and tourists with different equilibrium factors have been evaluated. The radiation exposure levels for workers and tourists only represent a low percentage of the exposure guides for the general population. - Highlights: → The aim of the study was to detect seasonal variation of 222 Rn concentrations. → 222 Rn concentrations in the air-cave were measured by continuous monitoring. → The 222 Rn measurements were carried out in the different halls of the cave. → The radiation exposure levels for workers and tourists have been evaluated.

  19. Use of 222Rn for estimation of greenhouse gases emissions at Russian territory

    Science.gov (United States)

    Berezina, E. V.; Elansky, N. F.

    2009-04-01

    It is well known that 222Rn is widely used as a tracer for studying different atmospheric processes including estimations of greenhouse gases emissions. Calculation of 222Rn fluxes from the soil into the atmosphere allows quantitative estimation of greenhouse gases emissions having the soil origin or sources of which are located near the surface. For accurate estimation of 222Rn fluxes detailed investigations of spatial and temporal variations of its concentrations are necessary. 222Rn concentrations data in the atmospheric surface layer over continental Russia from Moscow to Vladivostok obtained during the six TROICA (Transcontinental Observations Into the Chemistry of the Atmosphere) expeditions of the mobile laboratory along the Trans-Siberian railroad are analyzed. Spatial distribution, diurnal and seasonal variations of surface 222Rn concentrations along the Trans-Siberian railroad are investigated. According to the obtained data surface 222Rn concentration values above continental Russia vary from 0.5 to 75 Bq/m3 depending on meteorological conditions and geological features of the territory with the average value being 8.42 ± 0.10 Bq/m3. The average 222Rn concentration is maximum in the autumn expedition and minimum in the spring one. The factors mostly influencing 222Rn concentration variations are studied: surface temperature inversions, geological features of the territory, precipitations. 222Rn accumulation features in the atmospheric surface layer during night temperature inversions are analyzed. It was noted that during night temperature inversions the surface 222Rn concentration is 7 - 8 times more than the one during the nights without temperature inversions. Since atmospheric stratification determines accumulation and diurnal variations of many atmospheric pollutants as well as greenhouse gases its features are analyzed in detail. Surface temperature inversions were mainly observed from 18:00-19:00 to 06:00-07:00 in the warm season and from 16

  20. Plasma chemistry in wire chambers

    International Nuclear Information System (INIS)

    Wise, J.

    1990-05-01

    The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an 55 Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to remove trace water and oxygen contaminants from the gas resulted in an increase in the average molecular weight of the products, consistent with results from low-pressure rf-discharge plasmas. It is suggested that because water and oxygen inhibit polymer growth in the gas phase that they may also reduce polymer deposition in proportional tubes and therefore retard wire aging processes. Mechanistic implications of the plasma reactions of hydrocarbons with oxygen are suggested. Unresolved issues in this work and proposals for further study are discussed

  1. Studies on 222Rn concentration in ground water using smart radon monitor and assessment of the radiation dose to the population of Mysuru city

    International Nuclear Information System (INIS)

    Chandrashekara, M.S.; Pruthvi Rani, K.S.

    2017-01-01

    Radioactive elements originate from the earth's crust and make their way into air, water, food and eventually in to the living system. Even though 75% of the Earth's surface is covered by water, only about 0.3 % of the total water on the Earth is available for public use. The ground water contains trace amounts of radioactive elements and these radionuclides contribute significant amount of dose to living beings, through intake of water into the human body. Radon dissolved in water is released into air when it is used for cooking, drinking, bathing and washing purposes. Exposure of population to higher concentrations of radon and its progeny for a long time causes occurrence of lung cancer and pathological effects like respiratory functional changes. Radon is a main source of ionizing radiation of natural origin and the studies on radon concentrations in drinking water are of importance. A systematic study of 226 Ra and 222 Rn concentration in the drinking water samples was carried out in Mysuru city. The concentration of 226 Ra and 222 Rn was estimated in water samples using emanometry method employing scintillation cells and alpha counting system. The 222 Rn concentration in water was also measured using a Smart Radon Monitor (SRM) for comparison of the results. SRM is a technologically advanced real time, portable, radon monitor developed at BARC, Mumbai

  2. "Flat-Fish" Vacuum Chamber

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    The picture shows a "Flat-Fish" vacuum chamber being prepared in the ISR workshop for testing prior to installation in the Split Field Magnet (SFM) at intersection I4. The two shells of each part were hydroformed from 0.15 mm thick inconel 718 sheet (with end parts in inconel 600 for easier manual welding to the arms) and welded toghether with two strips which were attached by means of thin stainless steel sheets to the Split Field Magnet poles in order to take the vertical component of the atmospheric pressure force. This was the thinnest vacuum chamber ever made for the ISR. Inconel material was chosen for its high elastic modulus and strenght at chamber bake-out temperature. In this picture the thin sheets transferring the vertical component of the atmosferic pressure force are attached to a support frame for testing. See also 7712182, 7712179.

  3. An experimental propane bubble chamber

    International Nuclear Information System (INIS)

    Rogozinski, A.

    1957-01-01

    Describes a propane bubble chamber 10 cm in diameter and 5 cm deep. The body of the chamber is in stainless steel, and it has two windows of polished hardened glass. The compression and decompression of the propane are performed either through a piston in direct contact with the liquid, or by the action on the liquid, through a triple-mylar-Perbunan membrane, of a compressed gas. The general and also optimum working conditions of the chamber are described, and a few results are given concerning, in particular, the tests of the breakage-resistance of the windows and the measurements of the thermal expansion of the compressibility isotherm for the propane employed. (author) [fr

  4. Equipment for handling ionization chamber

    International Nuclear Information System (INIS)

    Altmann, J.

    1988-01-01

    The device consists of an ionization channel with an ionization chamber, of a support ring, axial and radial bearings, a sleeve, a screw gear and an electric motor. The ionization chamber is freely placed on the bottom of the ionization channel. The bottom part of the channel deviates from the vertical axis. The support ring propped against the axial bearing in the sleeve is firmly fixed to the top part of the ionization channel. The sleeve is fixed to the reactor lid. Its bottom part is provided with a recess for the radial bearing which is propped against a screw wheel firmly connected to the ionization channel. In measuring neutron flux, the screw wheel is rotated by the motor, thus rotating the whole ionization channel such that the ionization chamber is displaced into the reactor core.(J.B.). 1 fig

  5. General purpose nuclear irradiation chamber

    International Nuclear Information System (INIS)

    Nurul Fadzlin Hasbullah; Nuurul Iffah Che Omar; Nahrul Khair Alang Md Rashid; Jaafar Abdullah

    2013-01-01

    Nuclear technology has found a great need for use in medicine, industry, and research. Smoke detectors in our homes, medical treatments and new varieties of plants by irradiating its seeds are just a few examples of the benefits of nuclear technology. Portable neutron source such as Californium-252, available at Industrial Technology Division (BTI/ PAT), Malaysian Nuclear Agency, has a 2.645 year half-life. However, 252 Cf is known to emit gamma radiation from the source. Thus, this chamber aims to provide a proper gamma shielding for samples to distinguish the use of mixed neutron with gamma-rays or pure neutron radiation. The chamber is compatible to be used with other portable neutron sources such as 241 Am-Be as well as the reactor TRIGA PUSPATI for higher neutron dose. This chamber was designed through a collaborative effort of Kulliyyah Engineering, IIUM with the Industrial Technology Division (BTI) team, Malaysian Nuclear Agency. (Author)

  6. Holography in small bubble chambers

    International Nuclear Information System (INIS)

    Lecoq, P.

    1984-01-01

    This chapter reports on an experiment to determine the total charm cross section at different incident momenta using the small, heavy liquid bubble chamber HOBC. Holography in liquid hydrogen is also tested using the holographic lexan bubble chamber HOLEBC with the aim of preparing a future holographic experiment in hydrogen. The high intensity tests show that more than 100 incident tracks per hologram do not cause a dramatic effect on the picture quality. Hydrogen is more favorable than freon as the bubble growth is much slower in hydrogen. An advantage of holography is to have the maximum resolution in the full volume of the bubble chamber, which allows a gain in sensitivity by a factor of 10 compared to classical optics as 100 tracks per hologram look reasonable. Holograms are not more difficult to analyze than classical optics high-resolution pictures. The results show that holography is a very powerful technique which can be used in very high resolution particle physics experiments

  7. Annual effective dose equivalents arising from inhalation of 222Rn, 220Rn and their decay products in high background radiation area in China

    International Nuclear Information System (INIS)

    Zhang Zhonghou

    1985-01-01

    The author presents the data of on-the-sport investigations in the high background radiation area in Yangjiang County in 1975 and 1981. Monazite sand is contained in the soil of this area. The average concentrations of 222 Rn in the air indoors and out doors of the high background radiation area are 31.8 and 16.4 Bqm -3 respectively, which are equal to 2.9 and 1.5 times the average concentrations in the control area. The average concentrations of 220 Rn in the air indoors and outdoors of the high background area are 167.5 and 18.4 Bqm -3 , corresponding to 9.6 and 4.8 times those of the control area respectively. The average potential alpha energy concentrations for daughters of 222 Rn indoors and outdoors are 0.1 and 0.097 μJm -3 , which are equal to 2.6 and 2.2 times those of the control are respectively. The average potential alpha energy concentrations for daughters of 220 Rn indoors and outdoors are 0.255 and 0.053 μJm -3 , corresponding to 3.7 and 2.7 times those of the control area respectively. The average annual effective dose equivalents arising from inhalation of 222 Rn, 220 Rn and their decay products in high background radiation area are estimated to be 2.8 mSv per caput, in which 40.5% arise from 220 Rn and its decay products. This result is about 3 times that in the neighboring control area

  8. Test chamber for alpha spectrometry

    Science.gov (United States)

    Larsen, Robert P.

    1977-01-01

    Alpha emitters for low-level radiochemical analysis by measurement of alpha spectra are positioned precisely with respect to the location of a surface-barrier detector by means of a chamber having a removable threaded planchet holder. A pedestal on the planchet holder holds a specimen in fixed engagement close to the detector. Insertion of the planchet holder establishes an O-ring seal that permits the chamber to be pumped to a desired vacuum. The detector is protected against accidental contact and resulting damage.

  9. Laboratory Course on Drift Chambers

    International Nuclear Information System (INIS)

    Garcia-Ferreira, Ix-B.; Garcia-Herrera, J.; Villasenor, L.

    2006-01-01

    Drift chambers play an important role in particle physics experiments as tracking detectors. We started this laboratory course with a brief review of the theoretical background and then moved on to the the experimental setup which consisted of a single-sided, single-cell drift chamber. We also used a plastic scintillator paddle, standard P-10 gas mixture (90% Ar, 10% CH4) and a collimated 90Sr source. During the laboratory session the students performend measurements of the following quantities: a) drift velocities and their variations as function of the drift field; b) gas gains and c) diffusion of electrons as they drifted in the gas

  10. The knife-edge chamber

    International Nuclear Information System (INIS)

    Barasch, E.F.; Bowcock, T.J.V.; Drew, M.M.; Elliott, S.M.; Lee, B.; McIntyre, P.M.; Pang, Y.; Popovic, M.; Smith, D.D.

    1990-01-01

    In this paper the design for a new technology for particle track detectors is described. Using standard IC fabrication techniques, a pattern of microscopic knife edges and field-shaping electrodes can be fabricated on a silicon substrate. The knife-edge chamber uniquely offers attractive performance for the track chambers required for SSC detectors, for which no present technology is yet satisfactory. Its features include: excellent radiation hardness (10 Mrad), excellent spatial resolution (∼20 μm), short drift time (20 ns), and large pulse height (1 mV)

  11. Ionization chambers for LET determination

    DEFF Research Database (Denmark)

    Kaiser, Franz-Joachim; Bassler, Niels; Tölli, Heikki

    2010-01-01

    resolution and high sensitivity are necessary. For exact dosimetry which is done using ionization chambers (ICs), the recombination taking place in the IC has to be known. Up to now, recombination is corrected phenomenologically and more practical approaches are currently used. Nevertheless, Jaff´e's theory...... of columnar recombination was designed to model the detector efficiency of an ionization chamber. Here, we have shown that despite the approximations and simplification made, the theory is correct for the LETs typically found in clinical radiotherapy employing particles from protons to carbon ions...

  12. The Mark III vertex chamber

    International Nuclear Information System (INIS)

    Adler, J.; Bolton, T.; Bunnell, K.

    1987-07-01

    The design and construction of the new Mark III vertex chamber is described. Initial tests with cosmic rays prove the ability of track reconstruction and yield triplet resolutions below 50 μm at 3 atm using argon/ethane (50:50). Also performed are studies using a prototype of a pressurized wire vertex chamber with 8 mm diameter straw geometry. Spatial resolution of 35mm was obtained using dimethyl ether (DME) at 1 atm and 30 μm using argon/ethane (50/50 mixture) at 4 atm. Preliminary studies indicate the DME to adversely affect such materials as aluminized Mylar and Delrin

  13. Theoretical study of the diffusion 222Rn gas on activated charcoal

    International Nuclear Information System (INIS)

    Lopez, Fabio O.; Canoba, Analia C.

    2001-01-01

    The 222 Rn adsorption coefficient is the fundamental parameter characterizing activated carbon's ability to adsorb 222 Rn . In this work, it has been determined the 222 Rn coefficient adsorption for 222 Rn activated carbon detectors. Scintillation vials were used as detectors. The measurement of the 222 Rn activity adsorbed in activated carbon was made by a liquid scintillation measurement of its alpha-beta progeny decay. On the other hand, in this work a diffusion and adsorption model has been developed for the transport of 222 Rn in an activated carbon porous bed. The equation that describes these processes is a partial differential equation, of the second order with respect to axial coordinate, and the first order with respect to time. The equation was numerically solved using a finites differences method. With this model the 222 Rn activity adsorbed in the detector, for several situations, was calculated. The results were tested with the data obtained from series of experiences made in our laboratories. (author)

  14. Study of 222Rn variations in the soil air

    International Nuclear Information System (INIS)

    Holy, K.; Boehm, R.; Matos, M.; Polaskova, A.; Hola, O.

    1998-01-01

    A significant source of radon in the indoor atmosphere is represented by 222 Rn in the soil air, ie., by the fraction of radon atoms produced by alpha decay of 226 Ra in soil grains that escaped into soil pores. In the paper the results are presented of a three year monitoring of radon in soil air, using a 125 ml Lucas type scintillation cell. Radon concentration depth profiles in the soil in various seasons of the year were also measured, and saturated concentration of radon in soil air was found at a depth of about 2 m. Monthly variations in the radon concentration were observed over several months and the possible causes of the variations are discussed. Daily courses of radon concentration were also measured and the results are presented. (A.K.)

  15. Assessment pozzolanicity waste red ceramics produced in Valley Assu / RN

    International Nuclear Information System (INIS)

    Palhares, Rodolfo de Azevedo; Pereira, Arthur Ruan da Silva; Cabral, Kleber Cavalcanti; Nobrega, Andreza Kelly Costa

    2016-01-01

    It is known that both the cement industry as a ceramist contribute much to the generation of environmental impacts. Be the Co2 in the atmosphere, as well as the generation of excessive waste, reaching 20%. The objective of this study is to analyze the potential pozollanic of waste from the red ceramic industries Valley Assu / RN, in order that this material can be incorporated as alternative raw material in the manufacture of ecological and similar brick, replacing partially in its composition Portland cement. Thus contributing to reducing the environmental impact produced by both the ceramics industry, such as cement. To evaluate the efficiency of pozollanic material, it was made sample preparation and then the physico-chemical characterization. After performing tests, it was noticed that the material has the minimum requirements established in standard to be considered as pozollanic material. (author)

  16. A source of ground water 222Rn around Tachikawa fault

    International Nuclear Information System (INIS)

    Saito, Masaaki; Takata, Sigeru

    1994-01-01

    Radon ( 222 Rn) concentration in ground water was characteristically high on the south-western zone divided by the Tachikawa fault, Tokyo. (1) The concentration did not increase with depth, and alluvium is thick on the zone. The source of radon was not considered as the updraft from base rock through the fault. Comparing the south-western zone with its surrounding zone, the followings were found. (2) The distribution of tritium concentration was supported that water had easily permeated into ground on the zone. (3) As the zone is located beside the Tama River and its alluvial fan center, the river water had likely affected. The source of radon on the zone would be 226 Ra in the aquifer soil. It can be presumed that the water of the Tama River had permeated into ground on the zone and had accumulated 226 Ra. (author)

  17. A writing intensive introductory course for RN to BSN students.

    Science.gov (United States)

    Tesh, Anita S; Hyde, Yolanda M; Kautz, Donald D

    2014-01-01

    This article describes learning strategies used with RN to BSN students in their 1st nursing course to successfully learn how to write formal papers using the American Psychological Association (APA) format. This 1st nursing course, a writing intensive, requires 4 short papers with self, peer, and teacher critiques and opportunities to rewrite. Students learn the style of professional nursing discourse, mastery of APA format, and development of additional skills in following directions and in critiquing their own work. An additional benefit is to enhance learning about professional nursing topics. By mastering writing skills in this initial course, students are able to successfully complete writing assignments in future courses and, in some cases, move on to publication.

  18. Radionuclide fistulogram (RnF) in hemodialysis patients

    Energy Technology Data Exchange (ETDEWEB)

    Seo, I.S.; Sy, W.M.; Heneghan, W.; Manoli, A.; Gozum, M.

    1984-01-01

    Prosthetic graft A-V fistulae (AVf) (10 adults) and internal AVf (14 adults) as avenues of hemodialysis were created surgically in the limbs of 24 renal failure patients. AVf can malfunction or become obstructed and to date only contrast fistulography (CnF) is used to document such problems. Thirty-three RnF's were performed in 24 patients and CnF's in seven patients. Eleven had clinical features of AVf malfunction and 13 were asymptomatic. 99mTc compounds, TcO/sup -//sub 4/ or MDP (20 mCi) were injected into the AVf through a 19-gauge butterfly. 2 sec. dynamic images (qualitative data) and simultaneous computer acquisition in 64 x 64 byte mode with 0.5 sec/frame for 120 frames (quantitative data) were obtained. Normal qualitative and quantitative criteria were established. 10/11 symptomatic and 2/13 asymptomatic patients showed abnormal scintigraphic features and time activity curves indicating AVf malfunction. All 12 patients demonstrated abnormal collateral formation; 8/12 had stenosis, 3/12 showed equivocal stenosis and in 1/12 no stenosis was shown. In these 12 patients the S/sub 2/ (second circulation)/S/sub 1/ (initial circulation) ratio was below 10%. In 5/12 whose S/sub 2//S/sub 1/ ratio was less than 1%, the CnF and surgical repair confirmed the presence of stenosis. RnF appears to be a simple, benign, and accurate imaging procedure in the evaluation of AVf malfunction.

  19. Randon daughter exposure of the U.K. population

    International Nuclear Information System (INIS)

    Cliff, K.D.

    1980-01-01

    The highest dose to the body tissues from natural radioactivity is that to the bronchial epithelium arising predominantly from the short-lived daughters of 222 Rn with a lesser contribution from the daughters of 220 Rn. This paper discusses the estimation of current United Kingdom population exposure to these nuclides. At present the exposure for an average member of the population of the UK is 0.15 WLM y -1 when the winter ventilation rate is 0.8 h -1 . This will increase to 0.58 WLM y -1 if the winter ventilation rate is reduced to 0.2 h -1 . The use of electrostatic precipitators would decrease the measured WL but would not affect the unattached fraction of 222 Rn daughter products, which determines the dose to the epithelium. Other methods of reducing 222 Rn daughter concentrations under investigation include prevention of the ingress of 222 Rn from the subsoil and the coating of construction materials with a radon barrier

  20. Vibrations in the urban environment controlling 222Rn migration in soils

    International Nuclear Information System (INIS)

    Wiegand, J.

    1998-01-01

    Comparable to investigations looking for a connection of 222 Rn and earthquakes, this study shows the influence of subsurface vibrations on the 222 Rn concentration of the soil-gas in urban environments. Generally, the 222 Rn concentration increases through vibrations induced by trains, street-traffic and activities at project sites. The spatial radius of the 222 Rn increase due to vibrations reach highest values at project sites where piled foundations or metal panels are rammed into the ground (> 60 m). Along railway tracks the radius is wider (> 30 m) than along heavy traffic roads ( 222 Rn concentrations in soil-gas due to vibrations is the highest at project sites (53%). Along heavy traffic roads the increase of 222 Rn concentrations by motor vehicle traffic is higher (37%) than that by railway traffic (11.5%). The maximum increase of 400% was observed in a distance of 1 m from a railway track. In the vicinity of railway tracks a difference of the vibration influence according to unconsolidated rock (11.1%) or solid rock (11.8%) was not noticed. Beside this vibration effect, the overall 222 Rn level decreases with increasing distance to the vibration source, but only at locations laying above solid rocks. The observation of the increase of 222 Rn concentrations can be explained by a 'pump effect': the mechanical vibration of soil and mineral particles leads to an upward motion of the whole volume of soil-gas. Therefore, 222 Rn is pumped out of the soil to the atmosphere and as a result the upward transport is increased. (author)

  1. Relationship between 222Rn concentration in soil water and degree of saturation

    International Nuclear Information System (INIS)

    Hamada, Hiromasa; Komae, Takami

    1996-01-01

    The object of the researches an analyzing downward flow to groundwater using 222 Rn concentration in water as an indicator has been saturated flow. However, when groundwater table is low, downward flow from surface is unsaturated flow. In this paper, the authors represented the relationship between 222 Rn concentration in soil water and degree of saturation, and measured the vertical distributions of 222 Rn concentrations in groundwater and 222 Rn concentration in water table in the fields. As the results, it was found that 222 Rn concentrations in the vicinity of groundwater table decreased by unsaturated downward flow. Moreover, from the variation of 222 Rn concentrations in groundwater table, it was possible to show the occurrence of the unsaturated downward flow by paddy fields irrigation, i.e., the downward flow of the soil water pushed out by irrigation water, the unsaturated percolation in the irrigation period, and the redistribution of the soil water after the release of ponding water. The degree of saturation in downward flow was calculated to be about 50% from 222 Rn concentrations in the irrigation period and in the non-irrigation period. It was deduced that the value was within reasonable range considering the difference of the hydraulic conductivities between of the upper layer and of the lower layer. These results proved that the relationship between 222 Rn concentrations in soil water and degree of saturation represented by the authors was reasonable and that the analytical method using 222 Rn concentrations in groundwater table as an indicator was useful 10 analyze the actual stale of unsaturated downward flow. (author)

  2. Measurement of the "2"2"Rn concentration in residences and workplaces in the Riobamba City

    International Nuclear Information System (INIS)

    Cuadrado, C.; Carrasco, J.

    2016-10-01

    The "2"2"2Rn belongs to the "2"3"8U natural radioactive series, decays emitting alpha particles with a disintegration half-period of 3.82 days. Is a colorless and odorless gas that is imperceptible to people. Studies have shown that indoor radon exposure can lead to lung cancer, even for the relatively low levels of radon commonly found in residential buildings. Measurements of the radon concentration were carried out in residences, offices and university laboratories in the Riobamba City (Ecuador), characterizing the places by the building materials, their age, length of stay among other variables. A Corentium brand electronic detector was used, which gives a short reading in 24 hours and extended in 7 days. Using the radon dose conversion coefficient 0.017 mSv/y for 1 Bq/m"3, recommended by the ICRP annual doses were estimated for each site. The data obtained show that the ranges are acceptable and are within the Who recommendations, being out of range a teaching laboratory because it has natural uranium for practices. These measurements are the first to be carried out in the country and can be used to promote research of this type at local, national and regional level. (Author)

  3. Assessing urban air quality and its relation with radon (222Rn)

    International Nuclear Information System (INIS)

    Zoran, Maria; Savastru, Dan; Dida, Adrian

    2016-01-01

    This paper focuses on the assessment of air quality and its relation with radon ( 222 Rn) for Bucharest metropolitan area in Romania. Specifically, daily mean concentrations of particle matter (PM2.5, PM10), ozone (O 3 ), nitrogen dioxide (NO 2 ), sulphur dioxide (SO 2 ) and global air quality indices have been analyzed in relation with radon ( 222 Rn) concentrations measured in the air near the ground with AlphaGUARD Radon Monitoring System and CR-39 SSNTDs during 2012 year. Such new information is required by atmospheric sciences to prove suitability of 222 Rn as a tracer for atmospheric dynamics analysis as well as by epidemiological and radiological protection studies. (author)

  4. Online {sup 222}Rn removal by cryogenic distillation in the XENON100 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Aprile, E.; Anthony, M.; De Perio, P.; Gao, F.; Goetzke, L.W.; Greene, Z.; Lin, Q.; Messina, M.; Plante, G.; Rizzo, A.; Zhang, Y. [Columbia University, Physics Department, New York, NY (United States); Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Hogenbirk, E.; Tiseni, A. [Nikhef and the University of Amsterdam, Science Park, Amsterdam (Netherlands); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Scheibelhut, M.; Schindler, S. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Amaro, F.D.; Cardoso, J.M.R.; Lopes, J.A.M.; Orrigo, S.E.A.; Santos, J.M.F. dos; Silva, M. [University of Coimbra, Department of Physics, Coimbra (Portugal); Arneodo, F.; Benabderrahmane, M.L.; Di Giovanni, A.; Maris, I. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Barrow, P.; Baudis, L.; Franco, D.; Galloway, M.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F.; Wei, Y.; Wulf, J. [University of Zurich, Physik-Institut, Zurich (Switzerland); Bauermeister, B. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Stockholm University, AlbaNova, Department of Physics, Oskar Klein Centre, Stockholm (Sweden); Berger, T.; Brown, E.; Piro, M.C. [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY (United States); Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindner, M.; Undagoitia, T.M.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Bruno, G.; Gallo Rosso, A.; Molinario, A. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); Budnik, R.; Duchovni, E.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M.; Sivers, M. v. [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Calven, J.; Conrad, J.; Ferella, A.D.; Pelssers, B. [Stockholm University, AlbaNova, Department of Physics, Oskar Klein Centre, Stockholm (Sweden); Cervantes, M.; Lang, R.F.; Masson, D.; Pienaar, J.; Reichard, S.; Reuter, C. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Cussonneau, J.P.; Diglio, S.; Le Calloch, M.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D. [Universite de Nantes, SUBATECH, Ecole des Mines de Nantes, CNRS/In2p3, Nantes (France); Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M. [University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN, Bologna (Italy); Fei, J.; Ni, K.; Ye, J. [University of California, Department of Physics, San Diego, CA (United States); Fieguth, A.; Murra, M.; Rosendahl, S.; Weinheimer, C. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Fulgione, W. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Turin (Italy); Grandi, L.; Saldanha, R.; Shockley, E.; Upole, N. [University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Lindemann, S. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Meng, Y.; Stein, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Miguez, B.; Trinchero, G. [INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Turin (Italy); Naganoma, J.; Shagin, P. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Lavina, L.S. [LPNHE, Universite Pierre et Marie Curie, Universite Paris Diderot, CNRS/IN2P3, Paris (France); Tunnell, C. [Nikhef and the University of Amsterdam, Science Park, Amsterdam (Netherlands); University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Cristescu, I. [Karlsruhe Institute of Technology, Tritium Laboratory Karlsruhe, Eggenstein-Leopoldshafen (Germany); Collaboration: XENON Collaboration

    2017-06-15

    We describe the purification of xenon from traces of the radioactive noble gas radon using a cryogenic distillation column. The distillation column was integrated into the gas purification loop of the XENON100 detector for online radon removal. This enabled us to significantly reduce the constant {sup 222}Rn background originating from radon emanation. After inserting an auxiliary {sup 222}Rn emanation source in the gas loop, we determined a radon reduction factor of R > 27 (95% C.L.) for the distillation column by monitoring the {sup 222}Rn activity concentration inside the XENON100 detector. (orig.)

  5. Development of special ionization chambers for a quality control program in mammography

    International Nuclear Information System (INIS)

    Silva, Jonas Oliveira da

    2013-01-01

    Mammography is an imaging method that uses X-rays. The use of ionization chambers in mammography quality control programs presents an essential role which is to verify whether the parameters of the patient exposure are correct. However, the commercial ionization chambers for dosimetry in mammography represent a high cost for small and medium size clinics that wish to have this equipment or for professionals that work with quality control programs. The innovative feature of this work was to develop ionization chambers for this purpose. In this work ionization chambers for X radiation beams in the mammography energy range were designed, constructed and characterized. The ionization chambers were tested in standard X radiation beams at the LCI/IPEN. The main characterization tests performed with the ionization chambers were: saturation curve, linearity of response, angular and energy dependence. The response stability tests of the ionization chambers were also conducted at the LCI, presenting results within 2.0 % for long-term stability. The results of the remaining tests are in accordance with international standards. These ionization chambers were also submitted to quality control tests of mammography equipment: linearity of the air kerma rates, determination of half-value layers and mean glandular doses. The results for air kerma rate linearity were less than 10 %, as recommended in international standards. The mean glandular dose obtained with the developed chambers presented values comparable to those of commercial ionization chambers tested, with an estimated variation within international standards. (author)

  6. Measurements of 222 Rn in the indoor of dwellings in the Argentinean Republic

    International Nuclear Information System (INIS)

    Canoba, A.; Lopez, F.

    2006-01-01

    The 222 Rn is responsible for approximately half of the dose in the population resultant of the exposure to natural radiation. Most of this dose comes from the inhalation of the offspring of the 222 Rn, and these doses they are specially important in set closed. The concentration of gas radon has been measured in housings of different cities of the Argentinean Republic. The elected cities are representative of the different geologic areas of our territory. For this its were used as detecting measurement method of nuclear tracks, electret detectors and detectors based on the adsorption in activated coal. Its were analyzed a total of 2689 housings from 1983 to the date. The average value of the radon concentration obtained starting from the 2689 monitored housings was of 41.6 Bq.m -3 . The effective annual dose calculated starting from this radon concentration, using a dosimetric factor of 25 μSv.a -1 (Bq.m -3 ), which assumes an equilibrium factor of 0.4, was of 1.04 mSv. Also, with the objective of determining the dose in form more exact, during the year 2000 it put on to point a passive technique for the simultaneous measurement such the radon concentration like of the equilibrium factor. This technique uses in oneself device two detectors of nuclear traces. The average value obtained starting from 204 monitored housings by this method of simultaneous measurement turns out to be 47.1 Bq.m -3 and 0.36 the equilibrium factor, being obtained a value of effective annual dose of 1.38 mSv. It fits to highlight that are very few the values above 200 Bq.m -3 and in any case the 300 Bq.m -3 is overcome. Analyzing the average equilibrium factor measured of 0.36, it was concluded that having assumed an equilibrium factor of 0.4 was adequate, for what for great measurement campaigns it can continue using the simple method that determines only the radon concentration. Comparing the obtained results by both methods, although the first counts with a statistic more important

  7. Modelling the distribution of 222Rn concentration in a multi level, general purpose building

    International Nuclear Information System (INIS)

    Toro, Laszlo; Noditi, Mihaela; Gheorghe, Raluca; Gheorghe, Dan

    2008-01-01

    The importance of 222 Rn (radon) in the indoor air related to the exposure form natural sources is relatively well documented. About 30% of the individual effective dose from natural sources is coming from the inhalation of 222 Rn and his short lived daughters. In unfavorable conditions given by the soil porosity and the existence of upward air movement in the soil there is a possibility to have unusually high radon concentration in houses even on soil with 'normal' 226 Ra content. Some construction solutions (high indoor spaces) should generate a significant indoor-outdoor negative pressure differences and consequently upward air currents (stack effect) which will facilitate the entrance of radon in the building. This effect will multiply the possibility of migration of radon in the building. The difficulty of the prediction of radon migration in the soil-building system increase the importance of the mathematical modelling of the behavior of radon-soil emission, infiltration and migration in the building - in areas with high radon potential. For one level simple buildings there are several models in the literature but the information regarding the multilevel building models are relatively scarce. Two different approaches used to describe the behavior of the radon gas in large (mainly high) buildings have been analyzed: Direct approach: computational fluid dynamics, solving the transport equations for the whole building (the domain of the solution of the transport and flow equations is delimited by the building envelope - the external walls); the openings (internal and external) and ventilation are defined by the boundary conditions. This approach is quite complex, the equations are solved (numerically) for highly inhomogeneous medium but is based on the fundamental processes governing the transport. In the same time it gives the possibility to obtain a concentration pattern in every part of the building. Multi-zone approach treating the building as interconnected

  8. Testing an hydrogen streamer chamber

    CERN Multimedia

    1975-01-01

    A 2x10 cm gap streamer chamber, 35x55 cm2 in surface, was built and tested at CERN. Good tracks of cosmic rays were obtained up to atmospheric pressure, see F. Rohrbach et al, CERN-LAL (Orsay) Collaboration, Nucl. Instr. Methods 141 (1977) 229. Michel Cathenoz stand on the center.

  9. Bubble chamber: colour enhanced tracks

    CERN Multimedia

    1998-01-01

    This artistically-enhanced image of real particle tracks was produced in the Big European Bubble Chamber (BEBC). Liquid hydrogen is used to create bubbles along the paths of the particles as a piston expands the medium. A magnetic field is produced in the detector causing the particles to travel in spirals, allowing charge and momentum to be measured.

  10. Natural 222Rn and 220Rn indicate the impact of the Water–Sediment Regulation Scheme (WSRS) on submarine groundwater discharge in the Yellow River estuary, China

    International Nuclear Information System (INIS)

    Xu, Bochao; Xia, Dong; Burnett, William C.; Dimova, Natasha T.; Wang, Houjie; Zhang, Longjun; Gao, Maosheng; Jiang, Xueyan; Yu, Zhigang

    2014-01-01

    Highlights: • 220 Rn and 222 Rn were combined to locate intensive SGD sites. • Influence of WSRS to SGD was found for the first time. • SGD was a dominant nutrient pathway in the Yellow River estuary. - Abstract: Submarine groundwater discharge (SGD) in estuaries brings important influences to coastal ecosystems. In this study, we observed significant SGD in the Yellow River estuary, including a fresh component, during the Water–Sediment Regulation Scheme (WSRS) period. We used the 222 Rn and 220 Rn isotope pair to locate sites of significant SGD within the study area. Three apparent SGD locations were found during a non-WSRS period, one of which became much more pronounced, according to the remarkably elevated radon levels, during the WSRS. Increased river discharge (from 245 m 3 s −1 to 3560 m 3 s −1 ) and the elevated river water level (from 11 m to 13 m) during the WSRS led to a higher hydraulic head, enhancing groundwater discharge in the estuary. Our results suggest that high river discharge (>3000 m 3 s −1 ) might be necessary for elevated fresh submarine groundwater discharging (FSGD). Vertical profiles of salinity, DO and turbidity anomalies along the benthic boundary layer also indicated significant FSGD in the estuary during the WSRS. Nutrient concentrations had positive correlations with 222 Rn during a 24-h observation, which indicates that SGD is a dominant nutrient pathway in this area

  11. Indoor {sup 22}Rn and {sup 222}Rn concentration measurements inside the Teotihuacan pyramids using NTD and E-PERM methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa, G. [Instituto de Fisica, UNAM, Apartado Postal 20-364, 01000 Mexico, D.F. (Mexico)]. E-mail: espinosa@fisica.unam.mx; Golzarri, J.I. [Instituto de Fisica, UNAM, Apartado Postal 20-364, 01000 Mexico, D.F. (Mexico); Martinez, T. [Facultad de Quimica, UNAM, Edificio D, Ciudad Universitaria, Mexico, D.F. (Mexico); Navarrete, M. [Facultad de Quimica, UNAM, Edificio D, Ciudad Universitaria, Mexico, D.F. (Mexico); Bogard, J. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6480 (United States); Martinez, G. [Coordinacion Nacional de Conservacion del Patrimonio Cultural, Xicotencatl y General Anaya s/n, 04120 Mexico, D.F. (Mexico); Juarez, F. [Instituto de Geofisica, UNAM, Ciudad Universitaria, 04510 Mexico, D.F. (Mexico)

    2005-11-15

    Measurements of {sup 22}Rn (Thoron) and {sup 222}Rn (Radon) concentrations, inside the Sun and Moon pyramids of Teotihuacan's archeological zone in Mexico, are reported in this work. Two well-established methods, nuclear track detectors (NTDs), using open-close end cups with internal and external detectors of CR-39 polymer, and electret-passive environmental radon monitoring (E-PERM) were used for the measurements. This experiment had two objectives: to obtain better confidence in the {sup 22}Rn and {sup 222}Rn measurements inside the archeological tunnels, and to compare the data obtained in each one of the two methods. This experiment is specially interesting because of the very peculiar conditions where the measurements are made: high humidity, labyrinths with air currents, but almost constant temperature inside of the pyramid tunnels and galleries, notwithstanding of the temperature changes between the day and the night outside of the pyramid body. The {sup 222}Rn concentrations found in both the pyramids were lower than the action level proposed by the ICRP-65. These tunnels are not open to the public, but researchers from the Anthropology Institutions spend part of their time working there, in periods varying from 3 to 5 months.

  12. Embryo-fetal transfer of bevacizumab (Avastin) in the rat over the course of gestation and the impact of neonatal Fc receptor (FcRn) binding.

    Science.gov (United States)

    Thorn, Mitchell; Piche-Nicholas, Nicole; Stedman, Donald; Davenport, Scott W; Zhang, Ning; Collinge, Mark; Bowman, Christopher J

    2012-10-01

    There is concern about embryo-fetal exposure to antibody-based biopharmaceuticals based on the increase of such therapies being prescribed to women of childbearing potential. Therefore, there is a desire to better characterize embryo-fetal exposure of these molecules. The pregnant rat is a standard model for evaluating the potential consequences of exposure but placental transfer of antibody-based biopharmaceuticals is not well understood in this model. The relative embryo-fetal distribution of an antibody-based biopharmaceutical was evaluated in the rat. Bevacizumab (Avastin) was chosen as a tool antibody since it does not have significant target binding in the rat that might influence embryo-fetal biodistribution. Avastin was labeled with a fluorescent dye, characterized, and injected into pregnant rats at different gestation ages. Labeled Avastin in fetal tissues was visualized ex vivo using an IVIS 200 (Caliper, A PerkinElmer Company, Alameda, CA). Avastin localized to the fetus as early as 24-hr post intravenous injection of the dam, and was taken up by the fetus in a dose-dependent manner. Avastin was detectable in the developing embryo as early as gestation day 13 and continued to be transferred until the end of gestation. Fetal transfer of Avastins mutated in the portion of the antibody that binds the neonatal Fc receptor (FcRn) was tested in late gestation and was found to correlate with affinities of the mutant Avastin antibody to FcRn. The novel application of this imaging technology was used to characterize the onset and duration of Avastin maternal-fetal transfer in rats and the importance of FcRn binding. © 2012 Wiley Periodicals, Inc.

  13. Method of repairing incore structure and water sealing chamber

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Toshikazu; Sato, Sukenobu (Hitachi Nuclear Engineering Co. Ltd., Ibaraki (Japan)); Wada, Noriaki; Kurosawa, Koichi; Tsujimura, Hiroshi; Enomoto, Kunio.

    1993-11-26

    An incore-chamber main body comprises a guide tube, an insertion guide, an extensible arm, a device fixing mechanism, a gas supply pipe, a guide driving mechanism and an in-core chamber control device. The in-core chamber main body is installed and secured to an upper flange surface of a shroud. Reactor water is raised to a level below a flange of a reactor pressure vessel while supplying a dry gas from a gas supply pipe to make the inside of the shroud as a gas atmosphere. Subsequently, each of the devices is attached to the top end of the extensible arm, and the guide driving mechanism is operated by the in-core chamber control device to an aimed position for preventive maintenance or repair to conduct positioning and fixing by utilizing the guide tube and the insertion guide. This enables to conduct preventive maintenance or repair in a state where reactor water is present to the outside of the in-core reactor chamber while maintaining the in-core equipment in the gas atmosphere, thereby enabling to reduce operator's exposure dose. (I.N.).

  14. Method of repairing incore structure and water sealing chamber

    International Nuclear Information System (INIS)

    Kikuchi, Toshikazu; Sato, Sukenobu; Wada, Noriaki; Kurosawa, Koichi; Tsujimura, Hiroshi; Enomoto, Kunio.

    1993-01-01

    An incore-chamber main body comprises a guide tube, an insertion guide, an extensible arm, a device fixing mechanism, a gas supply pipe, a guide driving mechanism and an in-core chamber control device. The in-core chamber main body is installed and secured to an upper flange surface of a shroud. Reactor water is raised to a level below a flange of a reactor pressure vessel while supplying a dry gas from a gas supply pipe to make the inside of the shroud as a gas atmosphere. Subsequently, each of the devices is attached to the top end of the extensible arm, and the guide driving mechanism is operated by the in-core chamber control device to an aimed position for preventive maintenance or repair to conduct positioning and fixing by utilizing the guide tube and the insertion guide. This enables to conduct preventive maintenance or repair in a state where reactor water is present to the outside of the in-core reactor chamber while maintaining the in-core equipment in the gas atmosphere, thereby enabling to reduce operator's exposure dose. (I.N.)

  15. Comparison of outdoor activity size distributions of 220 Rn and 222 Rn progeny and their Influences on lung dosimetry distributions

    International Nuclear Information System (INIS)

    Mohamed, A.; El-Hussein, A.; Ahmed, A.

    2005-01-01

    In the case of internally deposited radionuclides, direct measurement of the energy absorbed from ionizing radiation emitted by the decaying radionuclides is rarely, if ever, possible. Therefore, one must rely on dosimetric models to obtain estimates of the spatial and temporal patterns of energy deposition in human lung. T These models always need some information about the parameters of activity size distributions of thoron and radon progeny. In the present work, the attached and unattached activity size distributions of thoron and radon progeny were measured in outdoor air of El-Minia, Egypt. The attached samples were collected using a low pressure Berner cascade impactor technique, while a constructed screen diffusion b attery was used for collecting the unattached samples. Most of the attached activities for 222 Rn and 220 Rn progeny were associated with the aerosol particles of the accumulation mode. The activity size distribution of thoron progeny was found to be shifted to slightly smaller particle size, compared to radon progeny. An analytical method has been developed to compute the local energy deposition of 2l2 Bi alpha particles in a target volume of 1 jam spheres located at different depths in bronchial epithelium. In order to reach the target, alpha particles travel either through tissue alone (near-wall dose) or through air and tissue (far-wall dose). It was found that the contribution of near-wall dose is higher than that of the far wall dose. While the depth-dose distributions for nuclides uniformly distributed within the epithelium are practically constant with

  16. Hydrostatic Hyperbaric Chamber Ventilation System

    Science.gov (United States)

    Sarguisingh, Miriam J.

    2012-01-01

    The hydrostatic hyperbaric chamber (HHC) represents the merger of several technologies in development for NASA aerospace applications, harnessed to directly benefit global health. NASA has significant experience developing composite hyperbaric chambers for a variety of applications. NASA also has researched the application of water-filled vessels to increase tolerance of acceleration forces. The combination of these two applications has resulted in the hydrostatic chamber, which has been conceived as a safe, affordable means of making hyperbaric oxygen therapy (HBOT) available in the developing world for the treatment of a variety of medical conditions. Specifically, HBOT is highly-desired as a possibly curative treatment for Buruli Ulcer, an infectious condition that afflicts children in sub-Saharan Africa. HBOT is simply too expensive and too dangerous to implement in the developing world using standard equipment. The HHC technology changes the paradigm. The HHC differs from standard hyperbaric chambers in that the majority of its volume is filled with water which is pressurized by oxygen being supplied in the portion of the chamber containing the patient s head. This greatly reduces the amount of oxygen required to sustain a hyperbaric atmosphere, thereby making the system more safe and economical to operate. An effort was taken to develop an HHC system to apply HBOT to children that is simple and robust enough to support transport, assembly, maintenance and operation in developing countries. This paper details the concept for an HHC ventilation and pressurization system to provide controlled pressurization and adequate washout of carbon dioxide while the subject is enclosed in the confined space during the administration of the medical treatment. The concept took into consideration operational complexity, safety to the patient and operating personnel, and physiological considerations. The simple schematic, comprised of easily acquired commercial hardware

  17. Estimate of 50-year dose commitment to various organs and tissues of the body from inhalation of 222Rn free of its daughters

    International Nuclear Information System (INIS)

    Bernard, S.R.; Ford, M.R.; Snyder, W.S.

    1976-01-01

    Some topics discussed are as follows: retention of 222 Rn in fat, bone, heart, muscle, skin, testes, and urinary bladder; retention equations for Rn; decay scheme for Rn and 226 Ra; metabolic models for Po, Pb, and Bi; dose estimates to target organs for 222 Rn and its daughters that are not inhaled but produced from decay of 222 Rn; and estimation of MPC for bone marrow, gonads, and total body

  18. Establishment of a radon test chamber

    International Nuclear Information System (INIS)

    Chen Chingjiang; Liu Chichang; Lin Yuming

    1993-01-01

    A walk-in type radon test chamber of 23 m 3 has been built for testing and calibration of radon measurement instruments. The environmental conditions of the test chamber can be varied within a wide range of values. The design objectives specification, monitoring instruments and testing results of this chamber are discussed. This test chamber is available for domestic radon researchers and its accuracy can be traced to the international standard. A routine intercomparison study will be held annually by using this chamber. Other tests like radon progeny and thoron standard may also be performed in this chamber. (1 fig.)

  19. Pencil-shaped radiation detection ionization chamber

    International Nuclear Information System (INIS)

    Suzuki, A.

    1979-01-01

    A radiation detection ionization chamber is described. It consists of an elongated cylindrical pencil-shaped tubing forming an outer wall of the chamber and a center electrode disposed along the major axis of the tubing. The length of the chamber is substantially greater than the diameter. A cable connecting portion at one end of the chamber is provided for connecting the chamber to a triaxial cable. An end support portion is connected at the other end of the chamber for supporting and tensioning the center electrode. 17 claims

  20. Mapping of 222Rn and 4He in soil gas over a karstic limestone-granite boundary: correlation of high indoor 222Rn with zones of enhanced permeability

    International Nuclear Information System (INIS)

    O'Connor, P.J.; Gallagher, V.; Van den Boom, G.

    1992-01-01

    Recent indoor radon reconnaissance surveys in Ireland have identified buildings with high radon concentrations (up to 1700 Bq.m -3 ) overlying Carboniferous karstic limestone sequences in the western part of the country. A detailed investigation of indoor 222 Rn and soil gas 222 Rn and 4 He concentrations has been carried out over a karstic limestone-uraniferous granite boundary in County Galway. High indoor 222 Rn concentrations occur in dwellings over both lithologies. Radon migratory routes in bedrock and overburden appear to be controlled by zones of enhanced permeability, e.g. fractures, faults, etc. which are defined by linear arrays of elevated 4 He soil gas values. While the ultimate source of radon remains conjectural, the greatly enhanced permeability of karstified limestone is thought to be of fundamental importance in providing a means of rapid radon transport into overlying soils and buildings. (author)

  1. Postmortem Changes in Pork Muscle Protein Phosphorylation in Relation to the RN Genotype

    DEFF Research Database (Denmark)

    Lametsch, René; Larsen, Martin Røssel; Essén-Gustavsson, Birgitta

    2011-01-01

    Postmortem changes in pork muscle protein phosphorylation in relation to the RN(-) genotype were investigated using one-dimensional gel electrophoresis and a phosphor specific staining. The phosphorylation levels of several protein bands were found to be affected by the RN(-) genotype and to change...... of phosphorylation of these key enzymes during the postmortem metabolism. The results illustrate that the protein phosphorylation level of the muscle proteins could be interpreted as a global metabolic fingerprint containing information about the activity status of the enzymes in the postmortem metabolism....... during postmortem development. Glycogen phosphorylase, phosphofructokinase, and pyruvate kinase were found in protein bands affected by the RN(-) genotype, and the phosphorylation profile indicates that part of the increased rate and extended pH decline of the RN(-) genotype could be a consequence...

  2. Measurements of 222Rn and 226Ra Levels in environmental samples by using liquid scintillation counter

    International Nuclear Information System (INIS)

    Moustafa, A.S.

    2004-01-01

    The advantageous of liquid scintillation counting technique for 6 Ra determination compared with other methods are the high counting efficiency and the easier sample preparation, with no need for sample pre-concentration. In this work, liquid scintillation counting system was used to measure 222 Rn and 226 Ra levels in environmental samples. The liquid scintillation cocktail was prepared in the laboratory and was found efficient for measuring 222 Rn. Soil, sediment and TENORM samples were dried, grind, sieved and added to hydrochloric acid, in a standard scintillation vial, preloaded with the liquid scintillation cocktail. By measuring 222 Rn levels in the prepared vials, at different intervals of time after preparation, 222 Rn and 226 Ra levels were determined

  3. Reducing RN Vacancy Rate: A Nursing Recruitment Office Process Improvement Project.

    Science.gov (United States)

    Hisgen, Stephanie A; Page, Nancy E; Thornlow, Deirdre K; Merwin, Elizabeth I

    2018-06-01

    The aim of this study was to reduce the RN vacancy rate at an academic medical center by improving the hiring process in the Nursing Recruitment Office. Inability to fill RN positions can lead to higher vacancy rates and negatively impact staff and patient satisfaction, quality outcomes, and the organization's bottom line. The Model for Improvement was used to design and implement a process improvement project to improve the hiring process from time of interview through the position being filled. Number of days to interview and check references decreased significantly, but no change in overall time to hire and time to fill positions was noted. RN vacancy rate also decreased significantly. Nurse manager satisfaction with the hiring process increased significantly. Redesigning the recruitment process supported operational efficiencies of the organization related to RN recruitment.

  4. Cape Point GAW Station Rn-222 detector: factors affecting sensitivity and accuracy

    CSIR Research Space (South Africa)

    Brunke, EG

    2002-05-01

    Full Text Available Specific factors of a baseline Rn-222 detector installed at Cape Point, South Africa, were studied with the aim of improving its performance. Direct sunlight caused air turbulence within the instrument, resulting in 13.6% variability...

  5. Results of Long-term Measurement of 222Rn Volume Activity in Soil Air

    International Nuclear Information System (INIS)

    Holy, K.; Matos, M.; Boem, R.; Stanys, T.; Hola, O.; Polaskova, A.

    1999-01-01

    Radon in the soil air was continuously monitored for four years. The measured volume activities differ one from another even three times. On the basis of the measured data the annual and average daily courses of the 222 Rn volume activity were studied for individual months. In annual courses the winter and also summer maxima of the 222 Rn volume activity were found out. The study of the average daily courses revealed that the oscillation of the 222 Rn volume activity about its average value during a day is only a few percent. For dry summer months a linear relation was found out between the changes of the 222 Rn volume activity and the changes of the atmospheric pressure in their average daily courses (Authors)

  6. Expected indoor 222Rn levels in counties with very high and very low lung cancer rates

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1989-01-01

    Counties in the US with high lung cancer rates should have higher average 222 Rn levels than counties with low lung cancer rates, assuming the average 222 Rn level in a county is not correlated with other factors that cause lung cancer. The magnitude of this effect was calculated, using the absolute risk model, the relative risk model, and an intermediate model, for females who died in 1950-1969. The results were similar for all three models. We concluded that, ignoring migration, the average Rn level in the highest lung cancer counties should be about three times higher than in the lowest lung cancer counties according to the theory. Preliminary data are presented indicating that the situation is quite the opposite: The average Rn level in the highest lung cancer counties was only about one-half that in the lowest lung cancer counties

  7. Potable water as a source of airborne 222Rn in US dwellings: a review and assessment

    International Nuclear Information System (INIS)

    Nazaroff, W.W.; Doyle, S.M.; Nero, A.V.; Sextro, R.G.

    1987-01-01

    Using a long-term-average, single-cell model and available data for U.S. housing, the concentration of 222 Rn in indoor air due to the use of potable water is assessed. The ratio of the airborne 222 Rn concentration to the concentration in water is represented by a lognormal distribution with geometric mean and geometric standard deviation of 0.65 X 10(-4) and 2.88, respectively, in fair agreement with the previously reported results of direct measurements of the ratio in 13 houses. By combining this result with data on 222 Rn concentrations in U.S. water supplies, potable water is estimated to contribute an average of 24, 1.3, and 0.1 Bq m-3 to the airborne 222 Rn concentration in residences served by private wells, public ground water, and surface water supplies, respectively

  8. Determining chance coincidence, survival factor and decay factor in 220Rn delayed coincidence measurement

    International Nuclear Information System (INIS)

    Huang Derong; Yan Yongjun; Zhou Jianliang; Qiu Shoukang

    2013-01-01

    The method and calculation formulas to determine the chance coincidence in the 220 Rn coincidence measurement are introduced in this paper. The poisson distribution is introduced to correct the chance coincidence. The relative deviation of the true coincidence between the method and the Giffin's is within 5% after the correction of the cohance coincidence. The measurement of 220 Rn is done by comparative measurement with RAD7. The results shows that 220 Rn can be measured by the method with a relative deviation of 14%. Mean while, for the 220 Rn flow regime is difficult to meet the condition of calculation formulas, a solution to solve the survival factor and decay factor is proposed and the error come from the useage of theoretical calculation formula is avoided. (authors)

  9. Indoor 222Rn measurements in the region of Beijing, People's Republic of China

    International Nuclear Information System (INIS)

    Ren, T.S.; Lin, L.Q.; Chen, Z.P.; Li, G.Y.; Chen, A.M.

    1987-01-01

    Passive integrating activated C detectors were used to study the regional distribution and temporal variation of 222 Rn in indoor air in dwellings in the Beijing region. Measurements were made in 537 dwellings, which were either detached houses or multi-family apartments. The city-wide study was completed in 1985. The distributions are approximately log-normal with 90% of the dwellings having 222 Rn levels less than 60 Bq m-3. The weighted average 222 Rn concentration has been found to be 22.4 Bq m-3. Averages for detached houses and multi-family dwellings are 25.9 and 15.2 Bq m-3, respectively. Assuming an equilibrium factor of 0.5 and an occupancy factor of 0.8, the average equilibrium equivalent concentration of 222 Rn progeny is 11.2 Bq m-3 and the annual average effective dose equivalent is 1.1 mSv

  10. Soil gas 222Rn and volcanic activity at El Hierro (Canary Islands) before and after the 2011 submarine eruption

    Science.gov (United States)

    Padilla, G.; Hernández, P. A.; Padrón, E.; Barrancos, J.; Melián, G.; Dionis, S.; Rodríguez, F.; Nolasco, D.; Calvo, D.; Hernández, I.; Pereza, M. D.; Pérez, N. M.

    2012-04-01

    El Hierro (278 km2) is the southwesternmost island of the Canarian archipelago. From June 19, 2011 to January 2012, more than 11,950 seismic events have been detected by the seismic network of IGN. On 10 October 2011 the earthquake swarm changed its behaviour and produced a harmonic tremor due to magma movement, indicating that a submarine eruption located at 2 km south of La Restinga had started which is still in progress. Since 2003, the ITER Environmental Research Division now integrated in the Instituto Volcanológico de Canarias, INVOLCAN, has regularly performed soil gas surveys at El Hierro as a geochemical tool for volcanic surveillance. Among the investigated gases, soil gas radon (222Rn) and thoron (220Rn) have played a special attention. Both gases are characterized to ascend towards the surface mainly through cracks or faults via diffusion or advection, mechanisms dependent of both soil porosity and permeability, which in turn vary as a function of the stress/strain changes at depth. Years before the starts of the volcanic-seismic crisis on July 17, 2011, a volcanic multidisciplinary surveillance program was implemented at El Hierro including discrete and continuous measurements of 222Rn and 220Rn. Two soil gas 222Rn surveys had been carried out at El Hierro in 2003 and 2011, and four continuous geochemical monitoring stations for 222Rn and 220Rn measurements had been installed (HIE02, HIE03, HIE04 and HIE08). Soil gas 222Rn surveys were carried out at the surface environment of El Hierro after selecting 600 sampling observation sites (about 40 cm depth). Geochemical stations measure 222Rn and 220Rn activities by pumping the gas from a PVC pipe inserted 1m in the ground and thermally isolated. The results of the 2003 and 2011 soil gas 222Rn surveys show clearly a relatively higher observed 222Rn activities in the surface environment on 2011 than those observed on 2003 when no anomalous seismicity were taking place beneath El Hierro. The observed

  11. Ionizing chamber smoke detectors in implementation of radiation protection standards

    International Nuclear Information System (INIS)

    1977-01-01

    In 1977 the NEA Steering Committee adopted a series of Recommendations for Ionizing Chamber Smoke Detectors (ICSDs) in Implementation of Radiation Protection Standards. The purpose of these recommendations is to permit adoption of a harmonized policy by the competent national authorities concerning the issue of licenses for the manufacture, import, use and disposal of ICSDs while insuring that individual and collective exposure doses are kept as low as is reasonably achievable [fr

  12. A passive environmental 222Rn monitor based on the exoelectron dosimeter

    International Nuclear Information System (INIS)

    Gammage, R.B.; Cheka, J.S.; Gesell, T.F.

    1978-01-01

    A high efficiency for BeO ceramic exoelectron dosimeters is demonstrated in the integrated monitoring of Mylar radon at concentrations close to natural background levels. Electrostatic collection of radon daughters onto aluminized mylar foil covering a BeO disk is achieved inside a porous, hemispherical chamber of the type developed by Costa-Ribeiro et al. This application of the exoelectron dosimeter for radon monitoring inside dwellings is a particularly favorable one; the lack of excessively high humidities and the clean conditions inside the hemisphere favor the reliable performance of the exoelectron dosimeter. Radon concentration - exposure times of 3 pCi h/l, or more, can be measured with an accuracy of about +-25% when the temperature and relative humidity are fluctuating. This means that radon concentrations of a few tenths of a pCi/l can be measured using exposure times of only a day or two. (Auth.)

  13. Development of an integrated sampler based on direct 222Rn/220Rn progeny sensors in flow-mode for estimating unattached/attached progeny concentration

    International Nuclear Information System (INIS)

    Mishra, Rosaline; Sapra, B.K.; Mayya, Y.S.

    2009-01-01

    A flow-mode integrated sampler consisting of a wire-mesh and filter-paper array along with passive solid state nuclear track detectors has been developed for estimating unattached and attached fraction of 222 Rn/ 220 Rn progeny concentration. The essential element of this sampler is the direct 222 Rn/ 220 Rn progeny sensor (DRPS/DTPS), which is an absorber-mounted-LR115 type nuclear track detector that selectively registers the alpha particles emitted from the progeny deposited on its surface. During sampling at a specified flow-rate, the unattached progeny is captured on the wire-mesh; while the attached progeny gets transmitted and is captured on the filter-paper. The alpha particles emitted by the deposited progeny atoms are registered on the sensors placed at a specified distance facing the wire-mesh and the filter-paper, respectively. The various steps involved in the development of this flow-mode direct progeny sampler such as the optimization of the sampling rate and the distance between the sensor and the deposition substrate are discussed. The sensitivity factor of the DTPS-loaded sampler for 220 Rn progeny deposited on the wire-mesh and filter-paper is found to be 23.77 ± 0.64 (track cm -2 h -1 ) (Bq m -3 ) -1 and 22.30 ± 0.18 (track cm -2 h -1 ) (Bq m -3 ) -1 , respectively; while that of DRPS-loaded sampler for 222 Rn progeny deposition, is 3.03 ± 0.14 (track cm -2 h -1 ) (Bq m -3 ) -1 and 2.08 ± 0.07 (track cm -2 h -1 ) (Bq m -3 ) -1 , respectively. The highlight of this flow-mode sampler is its high sensitivity and that it utilizes the passive technique for estimating the unattached and attached progeny concentration, thus doing away with the alpha counting procedures.

  14. Dose by 222 Rn in houses of the Chihuahua city

    International Nuclear Information System (INIS)

    Colmenero S, L.H.; Talamantes F, C.; Villalba, M.L.; Dobson, P.F.; Ortalejo M, B.

    2007-01-01

    Full text: The dose equivalent that the population of the Chihuahua city receives due to the radon in air that joined to values of uranium, thorium and potassium due to the floor and radon in water was determined, they give values very above the international and national norms. The state of Chihuahua contains near 56 locations distributed by the whole state. The city of Chihuahua, capital of the state, is surrounded of rocks with great content of uranium, for what their floor also contains to the 226 Ra that generates to the 222 Rn. The construction of the housings of the city of Chihuahua is mainly of brick, block and adobe; the material to elaborate them is take from the rocks and floor of the surroundings, this makes that the radon is presented in a great quantity of houses of this city. As the floor and water they also contain those natural radionuclides, the total dose equivalent that the inhabitants receive is bigger to other cities of the country. Diverse international organizations dedicated to the radioactivity, indicate that the level of the 222 Rn should not surpass the 148 Bq/m 3 , since this gas produces lung cancer. The state of Chihuahua has an index of deaths on the average by lung cancer of double the national average, the capital of the state also has a high index. The radon concentration in a house depends on the construction material with which was made, as well as of the existent climatic conditions. During the day, this concentration depends mainly on the interior temperature, so during the night and dawn increases the radon concentration. The radon is the biggest source of radioactive dose received by the human being and it can generate a problem of public health if the concentration is high during enough time, for what the city of Chihuahua has the geologic and climatic characteristics to have it. This study was carried out in 50 house-room of the city of Chihuahua. Built houses with brick, block and adobe were selected. The quantification

  15. Pædagoger og Perkere – etniske minoritetsbørn i det sociale system

    DEFF Research Database (Denmark)

    Vitus, Kathrine

    : hvad gør mødet med en socialpædagogisk institution ved og for etniske minoritetsbørn? Hvilke praksisser, manøvremuligheder og handlerum har pædagoger? Hvorfor er mødet mellem danske velfærdsinstitutioner, deres professionelle og etniske minoritetsbørn, unge og deres familier tilsyneladende så svært? I...

  16. rn, unge og sociale netværkssider. Hvad ved vi?

    DEFF Research Database (Denmark)

    Larsen, Malene Charlotte

    2012-01-01

    været. Herefter skal vi se på, hvordan børn og unge selv begrunder deres brug af sociale netværkssider, og hvilke motiver der ligger bag deres mange timer foran skærmen. Dernæst sætter kapitlet fokus på børn og unges venskaber på sociale netværkssider, hvad der karakteriserer et venskab i dag, og...

  17. Some remarks on exact methods for WL and 222Rn-daughter determination

    International Nuclear Information System (INIS)

    Groer, P.G.

    1977-01-01

    For an exact determination of the three 222 Rn-daughter concentrations (RaA, B and C) which properly weighted yield the Working Level, three equations relating observed counts (α or β) to these unknown concentrations have to be solved. The half-lives in the 222 Rn decay series, the type of decay and the counting errors, limit the suitable set of equations. Some aspects of two such exact methods are discussed

  18. Skolestøtte til børn i familiepleje – delrapport I

    DEFF Research Database (Denmark)

    Eiberg, Misja; Andersen, Luna Kragh; Scavenius Sonne-Schmidt, Christoffer

    I denne rapport beskrives resultaterne af et randomiseret kontrolleret forsøg med to skolestøttende indsatser til familieplejeanbragte børn i den danske folkeskole i alderen 6-14 år. Gennem afprøvningen af de to indsatser har forskningsprojektet ”Skolestøtte til børn i familiepleje” undersøgt, hv...

  19. ON A PROLONGATION CONSTRUCTION FOR LOCAL NON-DIVERGENT VECTOR FIELDS ON Rn

    Directory of Open Access Journals (Sweden)

    A. M. Lukatsky

    2015-01-01

    Full Text Available The problem of a prolongation of non-divergent vector field, defined in a vicinity of zero in Rn t, to a finite non-divergent vector field on Rn is considered. Explicit formulas for the elements of the simple Lie algebra of non-divergent vector from the well-known Cartan series are obtained. This construction allows to move from the Euler equations for the ideal incompressible fluid to the Euler equations on finite-dimensional Lie groups.

  20. Sårbare børn og unge i tandplejeregi i Danmark

    DEFF Research Database (Denmark)

    Uldum, Birgitte; Christensen, Hanne Nødgaard; Haubek, Dorte

    2016-01-01

    Hvorledes identificeres sårbare børn og unge i tandplejeregi i Danmark? I denne artikel sættes fokus på danske sårbare børn og unge i tandplejeregi og på udviklingen I Danmark siden 2009. En dansk spørgeskemaundersøgelse om tandplejens erfaring fra 2008 omtales kort. Der lægges vægt på det odonto...

  1. Update of the BIPM.RI(II)-K1.Rn-222 comparison of activity measurements for the radionuclide {sup 222}Rn to include the LNE-LNHB, France

    Energy Technology Data Exchange (ETDEWEB)

    Michotte, C.; Ratel, G. [Bureau International de Poids et Mesures, Pavillon de Breteuil, F-92312 Sevres cedex (France); Cassette, P. [Bureau International de Poids et Mesures, Pavillon de Breteuil, F-92312 Sevres cedex (France); Laboratoire national de metrologie et d' essais -Laboratoire national Henri Becquerel, 91191 Gif-sur-Yvette cedex (France)

    2012-02-15

    In 2007, the Laboratoire national de metrologie et d'essais - Laboratoire national Henri Becquerel (LNE-LNHB), France submitted a sample of known activity of {sup 222}Rn to the International Reference System (SIR) for comparison. The value of the activity submitted was about 90 kBq. This key comparison result joins that of Switzerland and Germany in the key comparison database that now contains three results, identifier BIPM.RI(II)-K1.Rn-222. Consequently, the KCRV has been updated and the degrees of equivalence with the KCRV have been evaluated. (authors)

  2. Trends and reduction scenarios for Rn 222 concentrations in dwellings

    International Nuclear Information System (INIS)

    Blaauboer, R.O.; Heling, R.

    1993-07-01

    In the title study the effects of possible measures on the average radon concentration in Dutch dwellings is evaluated. Attention is paid to the trends in building methods, the use of building materials and using the trends as a reference development (scenario 0). A total of seven scenarios has been evaluated. The model that was used was kept rather simple, because most of the parameter values are average values. The measures studied were selected on the basis of cost-effectiveness. All measures are based on reducing the infiltration of radon from the crawl space under the house to the living quarters and reducing the exhalation rates of building materials. The evaluation shows a rather good match with earlier measurements and projections as far as the average radon concentration is concerned. The trend, i.e. the development without taking measures directed at reducing the radon concentration, predicts a slow increase of about 15% until approximately the year 2025. The scenario that is directed at using concrete with low Ra-226 concentrations in new houses projects an end to this trend. Other scenarios reveal that taking measures solely in the existing housing stock would give a substantial decrease in radon concentrations in the near future. The spread sheet model that was developed to evaluate the consequences of the different scenarios projects a possible reduction of the average radon concentration in dwellings with 25% by the year 2025, compared to 1991, if measures, directed at Rn-reduction are applied. If in addition to that concrete with low Ra-226 concentrations is used in new buildings, a reduction of the average radon concentration is projected of about 30%. This would result in an average radon concentration in dwellings of about 23 Bq.m -3 in the future. These reduction percentages have to be handled with some care however, because the effect of the obviously occurring uncertainties in several parameters used, are not yet quite clear. Trends in and the

  3. Development of multiwire proportional chambers

    CERN Multimedia

    Charpak, G

    1969-01-01

    It has happened quite often in the history of science that theoreticians, confronted with some major difficulty, have successfully gone back thirty years to look at ideas that had then been thrown overboard. But it is rare that experimentalists go back thirty years to look again at equipment which had become out-dated. This is what Charpak and his colleagues did to emerge with the 'multiwire proportional chamber' which has several new features making it a very useful addition to the armoury of particle detectors. In the 1930s, ion-chambers, Geiger- Muller counters and proportional counters, were vital pieces of equipment in nuclear physics research. Other types of detectors have since largely replaced them but now the proportional counter, in new array, is making a comeback.

  4. LEP vacuum chamber, early prototype

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    The structure of LEP, with long bending magnets and little access to the vacuum chamber between them, required distributed pumping. This is an early prototype for the LEP vacuum chamber, made from extruded aluminium. The main opening is for the beam. The small channel to the right is for cooling water, to carry away the heat deposited by the synchroton radiation from the beam. The 4 slots in the channel to the left house the strip-shaped ion-getter pumps (see 7810255). The ion-getter pumps depended on the magnetic field of the bending magnets, too low at injection energy for the pumps to function well. Also, a different design was required outside the bending magnets. This design was therefore abandoned, in favour of a thermal getter pump (see 8301153 and 8305170).

  5. Single wire drift chamber design

    International Nuclear Information System (INIS)

    Krider, J.

    1987-01-01

    This report summarizes the design and prototype tests of single wire drift chambers to be used in Fermilab test beam lines. The goal is to build simple, reliable detectors which require a minimum of electronics. Spatial resolution should match the 300 μm rms resolution of the 1 mm proportional chambers that they will replace. The detectors will be used in beams with particle rates up to 20 KHz. Single track efficiency should be at least 99%. The first application will be in the MT beamline, which has been designed for calibration of CDF detectors. A set of four x-y modules will be used to track and measure the momentum of beam particles

  6. Systematic Review: Bridging the Gap in RPN-to-RN Transitions.

    Science.gov (United States)

    Suva, Grace; Sager, Shelley; Mina, Elaine Santa; Sinclair, Nancy; Lloyd, Monique; Bajnok, Irmajean; Xiao, Sarah

    2015-07-01

    To review the evidence examining the influences of successful education and professional role transition for registered practical nurses (RPNs) pursuing a baccalaureate degree in nursing (BScN) and registered nurse (RN) licensure through RPN-to-RN bridging programs. Systematic review of papers published between 1995 and 2014 that evaluated students' education and professional role transitions from RPN to RN. Thirty-nine papers were selected that observed or studied the change or transition in designation from RPN to RN, or its equivalent, through bridging programs and analyzed thematically according to Meleis, Sawyer, Im, Hilfinger Messias, and Schumacher's transition model. Personal, community, and social conditions related to preparation for entry, program enrolment, and postgraduate clinical integration influence successful education and professional role transitions for RPN-to-RN bridging students. Providing key transition supports may enhance the potential for successful student transition into and throughout a bridging program, but further research is necessary to enhance this understanding and to recommend best practices for optimizing students' success. The evidence from this review identifies facilitators and barriers to successful education and professional role transition for RPN-to-RN bridging students, and identifies important considerations for future research. © 2015 Sigma Theta Tau International.

  7. Dynamics of Rn transport from the cellar to the living area in an unheated house

    International Nuclear Information System (INIS)

    Furrer, D.; Crameri, R.; Burkart, W.

    1991-01-01

    Environmental parameters such as temperature and wind, occupant activities, and house-specific parameters such as subsoil geology, leakiness of the substructure to soil gas, and air exchange rate are the main factors influencing Rn entry into a building and its subsequent indoor behavior. Experiments performed in an unheated, uninhabited house showed a reproducible diurnal fluctuation of the indoor concentration of Rn decay products. Strong, long-term correlations between temperature differences indoor-outdoor (indoor temperature minus outdoor temperature) and pressure differences outdoor-indoor (outdoor pressure minus indoor pressure) were found. At positive temperature differences inside-outside, an average airflow velocity of about 0.05 m s-1 between ground floor and first floor was detected. This air movement was able to vertically transport Rn at a rate of approximately 11 kBq h-1 in a volume of air of about 5.5 m3 through a cross-sectional area of only 0.03 m2. For this specific house, stack effects were identified as the main driving force for Rn migration from the cellular to higher floors. The diurnal fluctuation of Rn progeny concentrations in the living area can be explained by temporal variations in the amount of Rn-rich air transported vertically from the cellar into the building as a consequence of stack effects

  8. Determination and assessment of Rn in mineral springs of Shandong province

    International Nuclear Information System (INIS)

    Xu Jia'ang; Li Fusheng; Chen Yingmin; Chen Yue; Deng Daping; Yuan Ming; Song Gang; Zhang Lianping

    2002-01-01

    Objective: The concentrations and its changes of 222 Rn in mineral springs of Shandong were determined in order to evaluate the committed equivalent dose for people drinking the water. Methods: Scintillation flask method is used for the measurement of 222 Rn concentrations in mineral springs. Results: The concentrations of 222 Rn in mineral springs of Shandong ranged from 0.51 Bq·L -1 to 807.20 Bq·L -1 , the geometric average of it was 22.09 Bq·L -1 . The relationship between the ratios of 222 Rn remains in the water under the natural conditions (P) and the period of time exposed in air (T) was discovered, which is fits for the following function relation: P = 46.666 T -0.517 (0.117 h≤T≤9 h). The committed equivalent dose resulting from 222 Rn concentrations was estimated to be 9.68 x 10 -2 mSv·a -1 , Which is due to drinking the water. Conclusion: The analyses of data indicate that there is no over-burden dose from 222 Rn for people who drink the water of mineral springs of Shandong

  9. Estimating the relation between groundwater and river water by measuring the concentration of Rn-222

    Energy Technology Data Exchange (ETDEWEB)

    Yoneda, Minoru; Morisawa, Shinsuke [Kyoto Univ. (Japan). Faculty of Engineering

    1997-02-01

    This study aimed to estimate the relationship between groundwater in shallow layer and river water by determining the concentrations of {sup 222}Rn and nitric nitrogen along with water temperature. The region around ca. 20 km along river A in a certain basin was chosen as a test area. The Rn concentration of groundwater was determined by Rn extracting with toluene and counting in liquid scintillation counter, whereas for river water, it was determined by activated charcoal passive collector method developed by the authors, by which the amount of Rn adsorbed on activated charcoal was estimated by Ge-solid state detector. In addition, water temperature and nitric nitrogen concentration were measured at various points in the test area. Thus, a distribution map of the three parameters was made on the basis of the data obtained in December, 1989. Since Rn concentration is generally higher in ground water than river water and the water temperature in December is higher in the former, it seems likely that the concentrations of Rn and nitric nitrogen would become higher in the area where ground water soaks into river water. Thus, the directions of ground water flow at the respective sites along river A were estimated from the data regarding the properties of ground water. (M.N.)

  10. MPS II drift chamber system

    International Nuclear Information System (INIS)

    Platner, E.D.

    1982-01-01

    The MPS II detectors are narrow drift space chambers designed for high position resolution in a magnetic field and in a very high particle flux environment. Central to this implementation was the development of 3 multi-channel custom IC's and one multi-channel hybrid. The system is deadtimeless and requires no corrections on an anode-to-anode basis. Operational experience and relevance to ISABELLE detectors is discussed

  11. GBO RF Anechoic Chamber & Antenna Test Range

    Data.gov (United States)

    Federal Laboratory Consortium — A shielded anechoic chamber measuring 15 by 15 by 37 feet is located in the Jansky Laboratory at Green Bank. This chamber has been outfitted as a far-field antenna...

  12. The KEK 1 m hydrogen bubble chamber

    International Nuclear Information System (INIS)

    Doi, Yoshikuni; Araoka, Osamu; Hayashi, Kohei; Hayashi, Yoshio; Hirabayashi, Hiromi.

    1978-03-01

    A medium size hydrogen bubble chamber has been constructed at the National Laboratory for High Energy Physics, KEK. The bubble chamber has been designed to be operated with a maximum rate of three times per half a second in every two second repetition time of the accelerator, by utilizing a hydraulic expansion system. The bubble chamber has a one meter diameter and a visible volume of about 280 l. A three-view stereo camera system is used for taking photographic pictures of the chamber. A 2 MW bubble chamber magnet is constructed. The main part of the bubble chamber vessel is supported by the magnet yoke. The magnet gives a maximum field of 18.4 kG at the centre of the fiducial volume of the chamber. The overall system of the KEK 1 m hydrogen bubble chamber facility is described in some detail. Some operational characteristics of the facility are also reported. (auth.)

  13. Dorsal skinfold chamber models in mice

    Directory of Open Access Journals (Sweden)

    Schreiter, Jeannine

    2017-07-01

    Full Text Available Background/purpose: The use of dorsal skinfold chamber models has substantially improved the understanding of micro-vascularisation in pathophysiology over the last eight decades. It allows pathophysiological studies of vascularisation over a continuous period of time. The dorsal skinfold chamber is an attractive technique for monitoring the vascularisation of autologous or allogenic transplants, wound healing, tumorigenesis and compatibility of biomaterial implants. To further reduce the animals’ discomfort while carrying the dorsal skinfold chamber, we developed a smaller chamber (the Leipzig Dorsal Skinfold Chamber and summarized the commercial available chamber models. In addition we compared our model to the common chamber. Methods: The Leipzig Dorsal Skinfold Chamber was applied to female mice with a mean weight of 22 g. Angiogenesis within the dorsal skinfold chamber was evaluated after injection of fluorescein isothiocyanate dextran with an Axio Scope microscope. The mean vessel density within the dorsal skinfold chamber was assessed over a period of 21 days at five different time points. The gained data were compared to previous results using a bigger and heavier dorsal skinfold model in mice. A PubMed and a patent search were performed and all papers related to “dorsal skinfold chamber” from 1 of January 2006 to 31 of December 2015 were evaluated regarding the dorsal skinfold chamber models and their technical improvements. The main models are described and compared to our titanium Leipzig Dorsal Skinfold Chamber model.Results: The Leipzig Dorsal Skinfold Chamber fulfils all requirements of continuous models known from previous chamber models while reducing irritation to the mice. Five different chamber models have been identified showing substantial regional diversity. The newly elaborated titanium dorsal skinfold chamber may replace the pre-existing titanium chamber model used in Germany so far, as it is smaller and lighter

  14. Use of commercial radon monitors for low level radon measurements in dynamically operated VOC emission test chambers

    International Nuclear Information System (INIS)

    Hofmann, M.; Richter, M.; Jann, O.

    2017-01-01

    Compared to the intended EU reference level of 300 Bq m -3 for indoor radon concentrations, the contribution of building materials appears to be low. Considering the recommended limit of 100 Bq m -3 by WHO, their contribution is supposed to be relevant, especially at low air exchange rates. This study as part of a two-part research project investigated the suitability of direct low level 222 Rn measurement under simulated indoor conditions with commercial radon monitors and dynamically operated emission test chambers. Active measuring devices based on ionisation or scintillation chambers with 1-σ uncertainties below 8.6% at 20 Bq m -3 were found to be best suitable for a practical test procedure for the determination of radon exhalation rates of building materials. For the measurement of such low concentrations, the knowledge of the accurate device background level is essential. (authors)

  15. Validation of the GA(2)LEN chamber for trials in allergy

    DEFF Research Database (Denmark)

    Zuberbier, Torsten; Abelson, Mark B; Akdis, Cezmi A

    2017-01-01

    BACKGROUND: Field clinical trials of pollen allergy are impacted by the impossibility to predict and to determine individual allergen exposure, due to many factors (e.g., pollen season, atmospheric variations, pollutants, lifestyles). Environmental exposure chambers (EEC), delivering a fixed amount...... of allergens in a controlled environmental setting, can overcome these limitations. EECs are currently already used in phase 2, 3, and even 4 trials. Unfortunately, few chambers exist in the world, and this makes it difficult to perform large, multicenter clinical trials. The new GA(2)LEN mobile exposure...

  16. Growing and analyzing biofilms in flow chambers

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim; Sternberg, Claus

    2011-01-01

    This unit describes the setup of flow chamber systems for the study of microbial biofilms, and methods for the analysis of structural biofilm formation. Use of flow chambers allows direct microscopic investigation of biofilm formation. The biofilms in flow chambers develop under hydrodynamic......, and disassembly and cleaning of the system. In addition, embedding and fluorescent in situ hybridization of flow chamber-grown biofilms are addressed....

  17. Analysis of Heat Stress and the Indoor Climate Control Requirements for Movable Refuge Chambers.

    Science.gov (United States)

    Hao, Xiaoli; Guo, Chenxin; Lin, Yaolin; Wang, Haiqiao; Liu, Heqing

    2016-05-20

    Movable refuge chambers are a new kind of rescue device for underground mining, which is believed to have a potential positive impact on reducing the rate of fatalities. It is likely to be hot and humid inside a movable refuge chamber due to the metabolism of trapped miners, heat generated by equipment and heat transferred from outside. To investigate the heat stress experienced by miners trapped in a movable refuge chamber, the predicted heat strain (PHS) model was used to simulate the heat transfer process between the person and the thermal environment. The variations of heat stress with the temperature and humidity inside the refuge chamber were analyzed. The effects of air temperature outside the refuge chamber and the overall heat transfer coefficient of the refuge chamber shell on the heat stress inside the refuge chamber was also investigated. The relationship between the limit of exposure duration and the air temperature and humidity was numerically analyzed to determine the upper limits of temperature and humidity inside a refuge chamber. Air temperature of 32 °C and relative humidity of 70% are recommended as the design standard for internal thermal environment control of movable refuge chambers.

  18. Analysis of Heat Stress and the Indoor Climate Control Requirements for Movable Refuge Chambers

    Directory of Open Access Journals (Sweden)

    Xiaoli Hao

    2016-05-01

    Full Text Available Movable refuge chambers are a new kind of rescue device for underground mining, which is believed to have a potential positive impact on reducing the rate of fatalities. It is likely to be hot and humid inside a movable refuge chamber due to the metabolism of trapped miners, heat generated by equipment and heat transferred from outside. To investigate the heat stress experienced by miners trapped in a movable refuge chamber, the predicted heat strain (PHS model was used to simulate the heat transfer process between the person and the thermal environment. The variations of heat stress with the temperature and humidity inside the refuge chamber were analyzed. The effects of air temperature outside the refuge chamber and the overall heat transfer coefficient of the refuge chamber shell on the heat stress inside the refuge chamber was also investigated. The relationship between the limit of exposure duration and the air temperature and humidity was numerically analyzed to determine the upper limits of temperature and humidity inside a refuge chamber. Air temperature of 32 °C and relative humidity of 70% are recommended as the design standard for internal thermal environment control of movable refuge chambers.

  19. Application of a tandem ionization chamber in a quality control program of X-ray beams, radiotherapy level

    International Nuclear Information System (INIS)

    Yoshizumi, Maira T.; Caldas, Linda V.E.

    2008-01-01

    A tandem ionization chamber, developed at the Instituto de Pesquisas Energeticas e Nucleares (IPEN), for X radiation beams, radiotherapy level, was applied into a quality control program of the Calibration Laboratory of IPEN. This ionization chamber is composed by two ionization chambers, with a volume of 0.6 cm 3 each one. Its inner plane-parallel electrodes and guard rings are made of different materials: one is made of aluminum and the other is made of graphite. Because of this difference in materials, the ionization chamber forms a tandem system. The relative response of the calibration factors of both sides of the chamber allows an easy verification of the X-ray beam qualities stability. The ionization chamber was submitted to some tests to verify the stability of its response: leakage current before and after exposure, repeatability and reproducibility. The performance of the ionization chamber was satisfactory. (author)

  20. BOREAS TGB-12 Rn-222 Flux Data over the NSA

    Science.gov (United States)

    Hall, Forrest G. (Editor); Conrad, Sara K.; Trumbore, Susan; Sundquist, Eric; Winston, Greg

    2000-01-01

    The BOREAS TGB-12 team made measurements of soil carbon inventories, carbon concentration in soil gases, and rates of soil respiration at several sites to estimate the rates of carbon accumulation and turnover in each of the major vegetation types. Sampling strategies for soils were designed to take advantage of local fire chronosequences, so that the accumulation of carbon in new moss growth could be determined. All the data are used to 1) calculate the inventory of carbon and nitrogen in moss and mineral soil layers at NSA sites, 2) determine the rates of input and turnover (using both accumulation since the last stand-killing fire and radiocarbon data), and 3) link changes in soil respiration rate to shifts in the C-14 content of soil CO2 to determine the average "age" respired CO2. These Rn-222 flux data were collected from 15-Nov-1993 to 16-Aug-1994 over the NSA sites. The data in this data set are stored in tabular ASCII files.

  1. BOREAS TGB-12 Rn-222 Activity Data over the NSA

    Science.gov (United States)

    Trumbore, Susan; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor); Sundquist, Eric; Winston, Greg

    2000-01-01

    The BOREAS TGB-12 team made measurements of soil carbon inventories, carbon concentration in soil gases, and rates of soil respiration at several sites to estimate the rates of carbon accumulation and turnover in each of the major vegetation types. Sampling strategies for soils were designed to take advantage of local fire chronosequences, so that the accumulation of carbon in regrowing mosses could be determined. All the data are used to: (1) calculate the inventory of carbon and nitrogen in moss and mineral soil layers at NSA sites, (2) determine the rates of input and turnover (using both accumulation since the last stand-killing fire and radiocarbon data), and (3) link changes in soil respiration rate to shifts in the C-14 content of soil CO2 to determine the average "age" respired CO2 . These Rn-222 activity data were collected from 15-Nov-1993 to 16-Aug-1994 over the NSA sites. They are useful for determining the rate of gas exchange between soil and the overlying atmosphere. The data in this data set are stored in tabular ASCII files.

  2. Effective removal of airborne 222Rn decay products inside buildings

    International Nuclear Information System (INIS)

    Maher, E.F.; Rudnick, S.N.; Moeller, D.W.

    1987-01-01

    Comparisons were made of the effectiveness of various indoor air treatment methods in reducing the lung dose due to inhalation of 222 Rn decay products. The comparisons were based upon measurements of the total steady-state concentrations of 218 Po, 214 Pb and 214 Bi, and the concentrations of these nuclides not attached to particles. These measurements, which were made inside a 78-m3 room before and after air treatment, were used along with a state-of-the art lung dose model to predict reductions in the dose to the radiosensitive bronchial tissues. Results suggest that flow-through air-cleaning methods, such as filtration and electrostatic precipitation, although effective in reducing total potential alpha energy concentration, cause a greater quantity of airborne potential alpha energy to be unattached to particles. This may result in a substantial increase in the dose to bronchial tissues. The optimal form of air treatment appears to be a combination of nonuniform positive space charge generated by an ion generator and enhanced convection from a fan. This combination of air treatment gave reductions in the mean dose to the bronchial tissues of up to 87%

  3. Impedances in lossy elliptical vacuum chambers

    International Nuclear Information System (INIS)

    Piwinski, A.

    1994-04-01

    The wake fields of a bunched beam caused by the resistivity of the chamber walls are investigated for a vacuum chamber with elliptical cross section. The longitudinal and transverse impedances are calculated for arbitrary energies and for an arbitrary position of the beam in the chamber. (orig.)

  4. Wire chamber degradation at the Argonne ZGS

    International Nuclear Information System (INIS)

    Haberichter, W.; Spinka, H.

    1986-01-01

    Experience with multiwire proportional chambers at high rates at the Argonne Zero Gradient Synchrotron is described. A buildup of silicon on the sense wires was observed where the beam passed through the chamber. Analysis of the chamber gas indicated that the density of silicon was probably less than 10 ppM

  5. Simple Cloud Chambers Using Gel Ice Packs

    Science.gov (United States)

    Kamata, Masahiro; Kubota, Miki

    2012-01-01

    Although cloud chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using cloud chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive cloud chamber that uses the contents of gel ice packs which can substitute for dry…

  6. Sensitivity of gaseous xenon ionisation chambers (1961)

    International Nuclear Information System (INIS)

    Schuhl, C.

    1960-01-01

    It seems advantageous to fill an ionization chamber with xenon gas when this chamber is used for measuring a low intensity and high energy electron or positron beam, or monitoring a gamma beam. In the study of 5 to 50 MeV electrons, xenon allows for the ionization chamber yield, an improvement of a factor 4,5. (author) [fr

  7. Proportional chambers and multiwire drift chambers at high rates

    International Nuclear Information System (INIS)

    Walenta, A.H.

    1977-01-01

    The high event and particle rates expected for ISABELLE intersecting storage rings raise the question whether PWC's and drift chambers, now widely in use in experiments, still can operate under such conditions. Various effects depend on the number of avalanches produced per length of wire N and the size of the avalanche Q, i.e., on the number of positive ions created in an avalanche. Therefore the important parameter for the following discussion is the product QN. The minimum Q is determined by the type and noise level of preamplifiers used. Examples are given for a typical low noise amplifier as well as for a typical integrated ''cheap'' amplifier. The rate/wire length N depends on the chamber arrangement, wire spacing, etc. In multiwire drift chambers, a single wire shows space-charge effects reducing the pulse height by 1% at a rate of N = 7 x 10 3 mm -1 sec -1 . At a rate of N approximately equal to 10 5 mm -1 sec -1 an efficiency loss of the order of 1% was noticed. The aging effect due to deposits on the anode wire can be reduced using low noise amplifiers and low gas gain to such an extent that a lifetime of about half a year at ISABELLE can be expected. The use of conventional cheap preamplifiers will result in a typical lifetime of about 30 days. Improvements are probable. The time resolution of Δt/sub r/ = 4 nsec fwhm seems adequate for event rates of 10 7 sec -1 . The memory time Δt/sub m/ greater than or equal to 100 nsec may cause serious problems for pattern recognition depending on layout and readout. The use of induced signals on cathode pads, thus reading out shorter parts of the wire, can solve the problem

  8. A basic radiation-education method using a handy-type cloud chamber and natural radiation sources

    International Nuclear Information System (INIS)

    Kushita, K. N.

    2010-10-01

    Nuclear human resources development becomes increasingly important due to the world trend of expanding nuclear energy utilization in this century. At the Nuclear Human Resource Development Center of the Japan Atomic Energy Agency, many kinds of nuclear and radiation education have been conducted consistently and continuously through its half-century history though having several organizational changes. High level education is required for the specialists of nuclear technology including nuclear power plants operators and engineers, while basic knowledge on nuclear energy and, specially, on radiations and radioisotopes should be given to school students and public. Besides lectures on radiation and radioisotopes, some basic experiments are useful to understand what are radiations and radioisotopes. One of such basic experiments is the cloud chamber experiment. It is a great fun and excitement even for small children as one can actually see the radiation tracks by his/her naked eyes at hand. While there are many types of cloud chambers, we have developed a new-type cloud chamber to use for the radiation education and training s. Using the new-type cloud chamber, we have further developed a new method of this experiment so that the participants can more deeply understand the phenomena and the nature of radiation and radioisotopes. In this method, using a radiation source of natural uranium ore and gaseous radiation source containing Rn-220 obtained from thorium-containing material, they not only observe the radiation tracks but also measure the length and count the number of the tracks. Then they can calculate the energy of the radiation (alpha ray) and can estimate the half-life of the radioisotope (Rn-220). This method can be applied for high-school and general university students as well as for the public as a useful and effective method in the radiation education. (Author)

  9. A basic radiation-education method using a handy-type cloud chamber and natural radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Kushita, K. N., E-mail: Kushita.kouhei@iaea.go.j [Japan Atomic Energy Agency, Nuclear Human Resource Development Center, 2-4 Shirakata-Shirane, Tokai, Naka, Ibaraki 309-1195 (Japan)

    2010-10-15

    Nuclear human resources development becomes increasingly important due to the world trend of expanding nuclear energy utilization in this century. At the Nuclear Human Resource Development Center of the Japan Atomic Energy Agency, many kinds of nuclear and radiation education have been conducted consistently and continuously through its half-century history though having several organizational changes. High level education is required for the specialists of nuclear technology including nuclear power plants operators and engineers, while basic knowledge on nuclear energy and, specially, on radiations and radioisotopes should be given to school students and public. Besides lectures on radiation and radioisotopes, some basic experiments are useful to understand what are radiations and radioisotopes. One of such basic experiments is the cloud chamber experiment. It is a great fun and excitement even for small children as one can actually see the radiation tracks by his/her naked eyes at hand. While there are many types of cloud chambers, we have developed a new-type cloud chamber to use for the radiation education and training s. Using the new-type cloud chamber, we have further developed a new method of this experiment so that the participants can more deeply understand the phenomena and the nature of radiation and radioisotopes. In this method, using a radiation source of natural uranium ore and gaseous radiation source containing Rn-220 obtained from thorium-containing material, they not only observe the radiation tracks but also measure the length and count the number of the tracks. Then they can calculate the energy of the radiation (alpha ray) and can estimate the half-life of the radioisotope (Rn-220). This method can be applied for high-school and general university students as well as for the public as a useful and effective method in the radiation education. (Author)

  10. Evaluation of {sup 222}Rn concentration of the internal and external environments of residences at Monte Alegre municipality, Para, Brazil; Avaliacao da concentracao do {sup 222}Rn nos ambientes internos e externos de residencias do municipio de Monte Alegre, PA

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Vicente de Paula

    1999-07-01

    The human being is constantly exposed to the natural radioactivity in the environment where he lives. This radioactivity comes mainly from materials present in the terrestrial crust that possess in their constitution chemical elements belonging to the radioactive families of uranium and thorium. The use of such materials for the construction of houses constitutes an important exposure form to the natural radiation, above all to the radioactive gas {sup 222}Rn, that it is exhaled from them. The Brazilian soil is composed, among other, of minerals that contain appreciable concentrations of these elements. The inhabitants of Monte Alegre town in Para, located at 2 deg 00' 24,9 'S ; 54 deg 04 ' 13,5 {sup W}, used in the construction of their houses stones obtained from an area 20 km distant of Monte Alegre, denominated Ingles de Souza, located at 01 deg 56' 4 0,1 S; 54 deg 12 149,7 W, where a small residential village, denominated National Agricultural Colony of Para (CANP), is located. The objective of this work was to evaluate the indoor concentration of {sup 222}Rn in the residences of Monte Alegre and CANP. Determinations of the {sup 238}U and {sup 226}Ra concentrations, measurements of the radon flux in samples of stones and soils of the two regions, as well as measurements to the gamma dose close of the soil and inside the residences, were also carried out. The average results of the radon concentration in the air of the investigated residences did not exceed the limits of 200 Bq. m{sup 3} (action level) and 600 Bq. m{sup 3} (intervention level) recommended by the International Commission on Radiological Protection (ICRP). The concentrations of natural radionuclides and the radon flux determined at the village showed values 17 times higher than those found at the urban area of Monte Alegre, while the average indoor gamma dose rate in the village residences was 0.86 mSv/a. (author)

  11. Are stepparents always evil? Parental death, remarriage, and child survival in demographically saturated Krummhörn (1720-1859) and expanding Québec (1670-1750).

    Science.gov (United States)

    Willführ, Kai P; Gagnon, Alain

    2013-01-01

    Parental death precipitates a cascade of events leading to more or less detrimental exposures, from the sudden and dramatic interruption of parental care to cohabitation with stepparents and siblings in a recomposed family. This article compares the effect of early parental loss on child survival in the past in the Krummhörn region of East Frisia (Germany) and among the French Canadian settlers of the Saint Lawrence Valley (Québec, Canada). The Krummhörn region was characterized by a saturated habitat, while the opportunities for establishing a new family were virtually unlimited for the French Canadian settlers. Early parental loss had quite different consequences in these dissimilar environments. Event history analyses with time-varying specification of family structure are used on a sample of 7,077 boys and 6,906 girls born between 1720 and 1859 in the Krummhörn region and 31,490 boys and 33,109 girls whose parents married between 1670 and 1750 in Québec. Results indicate that in both populations, parental loss is associated with increased infant and child mortality. Maternal loss has a universal and consistent effect for both sexes, while the impact of paternal loss is less easy to establish and interpret. On the other hand, the effect of the remarriage of the surviving spouse is population-specific: the mother's remarriage has no effect in Krummhörn, while it is beneficial in Québec. In contrast, the father's remarriage in Krummhörn dramatically reduces the survival chances of the children born from his former marriage, while such an effect is not seen for Québec. These population-specific effects appear to be driven by the availability of resources and call into question the universality of the "Cinderella" effect.

  12. Determination of radon exhalation from construction materials using VOC emission test chambers.

    Science.gov (United States)

    Richter, M; Jann, O; Kemski, J; Schneider, U; Krocker, C; Hoffmann, B

    2013-10-01

    The inhalation of (222) Rn (radon) decay products is one of the most important reasons for lung cancer after smoking. Stony building materials are an important source of indoor radon. This article describes the determination of the exhalation rate of stony construction materials by the use of commercially available measuring devices in combination with VOC emission test chambers. Five materials - two types of clay brick, clinker brick, light-weight concrete brick, and honeycomb brick - generally used for wall constructions were used for the experiments. Their contribution to real room concentrations was estimated by applying room model parameters given in ISO 16000-9, RP 112, and AgBB. This knowledge can be relevant, if for instance indoor radon concentration is limited by law. The test set-up used here is well suited for application in test laboratories dealing with VOC emission testing. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Unbiased stereological estimation of d-dimensional volume in Rn from an isotropic random slice through a fixed point

    DEFF Research Database (Denmark)

    Jensen, Eva B. Vedel; Kiêu, K

    1994-01-01

    Unbiased stereological estimators of d-dimensional volume in R(n) are derived, based on information from an isotropic random r-slice through a specified point. The content of the slice can be subsampled by means of a spatial grid. The estimators depend only on spatial distances. As a fundamental ...... lemma, an explicit formula for the probability that an isotropic random r-slice in R(n) through 0 hits a fixed point in R(n) is given....

  14. A mathematical model of aerosol holding chambers

    DEFF Research Database (Denmark)

    Zak, M; Madsen, J; Berg, E

    1999-01-01

    A mathematical model of aerosol delivery from holding chambers (spacers) was developed incorporating tidal volume (VT), chamber volume (Vch), apparatus dead space (VD), effect of valve insufficiency and other leaks, loss of aerosol by immediate impact on the chamber wall, and fallout of aerosol...... in the chamber with time. Four different spacers were connected via filters to a mechanical lung model, and aerosol delivery during "breathing" was determined from drug recovery from the filters. The formula correctly predicted the delivery of budesonide aerosol from the AeroChamber (Trudell Medical, London...

  15. Proceedings of workshop on streamer chamber

    International Nuclear Information System (INIS)

    Itoh, Hidihiko; Takahashi, Kaoru; Hirose, Tachishige; Masaike, Akira

    1978-08-01

    For high accuracy observation of multiple-body reactions, a vertex detector of high efficiency is essential. A bubble chamber, though excellent for tracks detection, is problematic in statistics accuracy. The vertex detector with a wire chamber, while better in this respect, difficult in multiple-particle detection etc. The workshop has had several meetings on a streamer chamber as a detector combining features of both bubble chamber and counter, with emphasis on tracks observation in avalanche mode and recordings not using films. Contents are on streamer chamber gas, analytical photography, data processing, simulation program, etc. (Mori, K.)

  16. SUPPLEMENTARY COMPARISON: COOMET.RI(II)-S1.Rn-222 (169/UA/98): Rn-222 volume activity comparison

    Science.gov (United States)

    Skliarov, V.; Röttger, A.; Honig, A.; Korostin, S.; Kuznetsov, S.; Lapenas, A.; Milevsky, V.; Ivaniukovich, A.; Kharitonov, I.; Sepman, S.

    2009-01-01

    According to a first program, a supplementary comparison of Rn-222 volume activity was drawn up as a bilateral supplementary comparison between NSC 'Institute of Metrology', Ukraine, and VNIIFTRI, Russia. It took place in March 2005. In April 2005, at the 5th meeting of COOMET held in Braunschweig (Germany), representatives of these institutes exchanged data which showed the comparability of the national standards of Ukraine and Russia for the check points. During the discussion of the procedure some other institutes decided to join the comparison program, which was extended to BelGIM (Belarus), PTB (Germany), VNIIM (Russia) and RMTC (Latvia). The national standards of volume activity of radon-222 were thus calibrated using one standard radon radiometer as the transfer standard. Results are shown in the Final Report of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by COOMET, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  17. In vivo measurements of lead-210 for assessing cumulative radon exposure in uranium miners

    Energy Technology Data Exchange (ETDEWEB)

    Guilmette, R.A.; Laurer, G.R. [New York Univ. Inst. of Environmental Medicine, Tuxedo, NY (United States); Lambert, W.E.; Gilliland, F.D. [Univ. of New Mexico, Albuquerque, NM (United States)] [and others

    1995-12-01

    It has long been recognized that a major contributor to the uncertainty in risk analysis of lung cancer in uranium and other hard rock miners is the estimation of total radon progeny exposure of individual miners under study. These uncertainties arise from the fact that only a limited number of measurements of airborne {sup 222}Rn progeny concentrations were made in the mines during the times that the miners were being exposed, and that dosimeters capable of integrating the Rn progeny exposures of the miners did not exist. Historically, the cumulative exposures for individual uranium and other hard rock miners have been calculated by combining the employee`s work history, which may or may not have included time spent at different jobs within the mines and at different locations within the mines, with whatever periodic measurements of Rn and Rn progeny were available. The amount and quality of the measurement data varied enormously from mine to mine and from population to population. Because the quality of the exposure data collected during the period of active mining in the United STates cannot now be altered substantially, significant improvement in individual miner exposure estimates is only likely to be achieved if a new cumulative exposure metric is developed and implemented. The decay chain of Rn includes the production of {sup 210}Pb, which can accumulate in the skeleton in amounts proportional to the intake of Rn progeny. We hypothesize that the in vivo measurement of {sup 210}Pb in the skulls of miners will provide such a metric. In summary, the primary purpose of this pilot study to demonstrate the feasibility of measuring {sup 210}Pb in the heads of former uranium miners has been accomplished.

  18. In vivo measurements of lead-210 for assessing cumulative radon exposure in uranium miners

    International Nuclear Information System (INIS)

    Guilmette, R.A.; Laurer, G.R.; Lambert, W.E.; Gilliland, F.D.

    1995-01-01

    It has long been recognized that a major contributor to the uncertainty in risk analysis of lung cancer in uranium and other hard rock miners is the estimation of total radon progeny exposure of individual miners under study. These uncertainties arise from the fact that only a limited number of measurements of airborne 222 Rn progeny concentrations were made in the mines during the times that the miners were being exposed, and that dosimeters capable of integrating the Rn progeny exposures of the miners did not exist. Historically, the cumulative exposures for individual uranium and other hard rock miners have been calculated by combining the employee's work history, which may or may not have included time spent at different jobs within the mines and at different locations within the mines, with whatever periodic measurements of Rn and Rn progeny were available. The amount and quality of the measurement data varied enormously from mine to mine and from population to population. Because the quality of the exposure data collected during the period of active mining in the United STates cannot now be altered substantially, significant improvement in individual miner exposure estimates is only likely to be achieved if a new cumulative exposure metric is developed and implemented. The decay chain of Rn includes the production of 210 Pb, which can accumulate in the skeleton in amounts proportional to the intake of Rn progeny. We hypothesize that the in vivo measurement of 210 Pb in the skulls of miners will provide such a metric. In summary, the primary purpose of this pilot study to demonstrate the feasibility of measuring 210 Pb in the heads of former uranium miners has been accomplished

  19. Evaluation of 222Rn concentration of the internal and external environments of residences at Monte Alegre municipality, Para, Brazil

    International Nuclear Information System (INIS)

    Melo, Vicente de Paula

    1999-01-01

    The human being is constantly exposed to the natural radioactivity in the environment where he lives. This radioactivity comes mainly from materials present in the terrestrial crust that possess in their constitution chemical elements belonging to the radioactive families of uranium and thorium. The use of such materials for the construction of houses constitutes an important exposure form to the natural radiation, above all to the radioactive gas 222 Rn, that it is exhaled from them. The Brazilian soil is composed, among other, of minerals that contain appreciable concentrations of these elements. The inhabitants of Monte Alegre town in Para, located at 2 deg 00' 24,9 'S ; 54 deg 04 ' 13,5 W , used in the construction of their houses stones obtained from an area 20 km distant of Monte Alegre, denominated Ingles de Souza, located at 01 deg 56' 4 0,1 S; 54 deg 12 149,7 W, where a small residential village, denominated National Agricultural Colony of Para (CANP), is located. The objective of this work was to evaluate the indoor concentration of 222 Rn in the residences of Monte Alegre and CANP. Determinations of the 238 U and 226 Ra concentrations, measurements of the radon flux in samples of stones and soils of the two regions, as well as measurements to the gamma dose close of the soil and inside the residences, were also carried out. The average results of the radon concentration in the air of the investigated residences did not exceed the limits of 200 Bq. m 3 (action level) and 600 Bq. m 3 (intervention level) recommended by the International Commission on Radiological Protection (ICRP). The concentrations of natural radionuclides and the radon flux determined at the village showed values 17 times higher than those found at the urban area of Monte Alegre, while the average indoor gamma dose rate in the village residences was 0.86 mSv/a. (author)

  20. Chamber propagation physics for heavy ion fusion

    International Nuclear Information System (INIS)

    Callahan, D.A.

    1995-01-01

    Chamber transport is an important area of study for heavy ion fusion. Final focus and chamber-transport are high leverage areas providing opportunities to significantly decrease the cost of electricity from a heavy ion fusion power plant. Chamber transport in two basic regimes is under consideration. In the low chamber density regime (approx-lt 0.003 torr), ballistic or nearly-ballistic transport is used. Partial beam neutralization has been studied to offset the effects of beam stripping. In the high chamber density regime (approx-gt.1 torr), two transport modes (pinched transport and channel transport) are under investigation. Both involve focusing the beam outside the chamber then transporting it at small radius (∼ 2 mm). Both high chamber density modes relax the constraints on the beam quality needed from the accelerator which will reduce the driver cost and the cost of electricity

  1. Chamber propagation physics for heavy ion fusion

    International Nuclear Information System (INIS)

    Callahan, D.A.

    1996-01-01

    Chamber transport is a key area of study for heavy ion fusion. Final focus and chamber transport are high leverage areas providing opportunities to decrease significantly the cost of electricity from a heavy ion fusion power plant. Chamber transport in two basic regimes is under consideration. In the low chamber density regime (below about 0.003 Torr), ballistic or nearly ballistic transport is used. Partial beam neutralization has been studied to offset the effects of beam stripping. In the high chamber density regime (above about 0.1 Torr), two transport modes (pinched transport and channel transport) are under investigation. Both involve focusing the beam outside the chamber and then transporting it at small radius (about 2 mm). Both high chamber density modes relax the constraints on the beam quality needed from the accelerator which will reduce the driver cost and the cost of electricity. (orig.)

  2. Loss of ions in cavity ionization chambers

    International Nuclear Information System (INIS)

    Takata, N.; Tran, N.T.; Kim, E.; Marsoem, P.; Kurosawa, T.; Koyama, Y.

    2005-01-01

    Ion losses due to initial recombination, volume recombination, and back diffusion were each determined by measurements and calculations for different size cylindrical ionization chambers and spherical ionization chambers. By measuring signal currents from these ionization chambers irradiated with 60 Co gamma rays, two groups of ion losses were obtained. (Group 1) Ion loss due to initial recombination and diffusion, which changes proportionally to the inverse of the voltage applied to the ionization chambers; (and group 2) ion loss due to volume recombination, which changes proportionally to the inverse of the square of the applied voltage. The diffusion loss was obtained separately by computing electric field distributions in the ionization chambers. It was found that diffusion loss is larger than initial recombination loss for the cylindrical ionization chambers and vise versa for the spherical ionization chambers

  3. TRU waste characterization chamber gloveboxes

    International Nuclear Information System (INIS)

    Duncan, D. S.

    1998-01-01

    Argonne National Laboratory-West (ANL-W) is participating in the Department of Energy's (DOE) National Transuranic Waste Program in support of the Waste Isolation Pilot Plant (WIPP). The Laboratory's support currently consists of intrusive characterization of a selected population of drums containing transuranic waste. This characterization is performed in a complex of alpha containment gloveboxes termed the Waste Characterization Gloveboxes. Made up of the Waste Characterization Chamber, Sample Preparation Glovebox, and the Equipment Repair Glovebox, they were designed as a small production characterization facility for support of the Idaho National Engineering and Environmental Laboratory (INEEL). This paper presents salient features of these gloveboxes

  4. Experimental work on drift chambers

    International Nuclear Information System (INIS)

    Alcaraz, J.; Duran, I.; Gonzalez, E.; Martinez-Laso, L.; Olmos, P.

    1989-01-01

    An experimental work made on drift chambers is described in two chapters. In the firt chapter we present the description of the experimental installation used, as well as some details on the data adquisition systems and the characteristics on three ways used for calibration proposes (cosmic muons, β radiation and test beam using SPS at CERN facilities). The second chapter describes the defferent prototypes studied. The experimental set up and the analysis are given. Some results are discussed. The magnetic field effect is also studied. (Author)

  5. Nova target chamber decontamination study

    International Nuclear Information System (INIS)

    1979-05-01

    An engineering study was performed to determine the most effective method for decontamination of the Nova target chamber. Manual and remote decontamination methods currently being used were surveyed. In addition, a concept that may not require in-situ decontamination was investigated. Based on the presently available information concerning material and system compatibility and particle penetration, it is recommended that a system of removable aluminum shields be considered. It is also recommended that a series of tests be performed to more precisely determine the vacuum compatibility and penetrability of other materials discussed in this report

  6. Gnathostomiasis of the anterior chamber

    Directory of Open Access Journals (Sweden)

    Barua P

    2007-01-01

    Full Text Available Ocular involvement with Gnathostoma spinigerum occurs years after the initial infection that is acquired by ingestion of poorly cooked, pickled seafood or water contaminated with third stage larvae. Here we report a case of gnathostomiasis of the left eye of a 32-year-old lady hailing from Meghalaya, India. Her vision had deteriorated to hand movement. Slit lamp examination revealed a live, actively motile worm in the anterior chamber, which was extracted by supra temporal limbal incision and visual acuity was restored.

  7. IL1RN and KRT13 Expression in Bladder Cancer: Association with Pathologic Characteristics and Smoking Status

    Directory of Open Access Journals (Sweden)

    Thomas S. Worst

    2014-01-01

    Full Text Available Purpose. To validate microarray data on cytokeratin 13 (KRT13 and interleukin-1 receptor antagonist (IL1RN expression in urothelial carcinoma of the urinary bladder (UCB and to correlate our findings with pathologic characteristics and tobacco smoking. Methods. UCB tissue samples (n=109 and control samples (n=14 were obtained from transurethral resection and radical cystectomy specimens. Immunohistochemical staining of KRT13 and IL1RN was performed and semiquantitative expression scores were assessed. Smoking status was evaluated using a standardized questionnaire. Expression scores were correlated with pathologic characteristics (tumor stage and grade and with smoking status. Results. Loss of KRT13 and IL1RN expression was observed in UCB tissue samples when compared to controls (P=0.007, P=0.008 in which KRT13 and IL1RN expression were high. IL1RN expression was significantly reduced in muscle-invasive tumors (P=0.003. In tissue samples of current smokers, a significant downregulation of IL1RN was found when compared to never smokers (P=0.013. Conclusion. Decreased expressions of KRT13 and IL1RN are common features of UCB and are associated with aggressive disease. Tobacco smoking may enhance the loss of IL1RN, indicating an overweight of proinflammatory mediators involved in UCB progression. Further validation of the influence of smoking on IL1RN expression is warranted.

  8. Design and construction of a radiation monitor with ionization chamber

    International Nuclear Information System (INIS)

    Ramirez J, F.J.

    1994-01-01

    The design and construction of a portable radiation monitor with ionization chamber for gamma and x rays measurements in the range from 40 KeV to 2 MeV are described in detail. The monitor is calibrated to give the exposure rate in Roentgens/hour in three linear ranges: 0-25 mR/h, 0-250 mR/h and 0-2500 mR/h for an ionization chamber with a sensitive volume of 600 cubic centimeters. Two conventional 9 V alkaline batteries are used to energize the monitor. The small current coming from the ionization chamber is measured by an operational amplifier with electrometer characteristics. The high voltage power supply to bias the chamber is made with a blocking oscillator and a ferrite transformer. Starting form a discussion of the desired characteristics of the monitor, the technical specifications are established. The design criteria for every section are shown. The testing procedures used to qualify every block and the results for three units are reported. (Author)

  9. Exposure to radon Rn-222 of inhabitants of buildings in Olsztyn

    International Nuclear Information System (INIS)

    Gorzkowski, B.; Pachocki, K.; Rozycki, Z.; Majle, T.; Pensko, J.; Krzeslak, A.

    1998-01-01

    The concentrations of radon-222 in the air of some buildings in Olsztyn were measured. The main source of radon in buildings is in general the ground under building and the materials used for building structure. In this work the results of radon-222 concentration measurements in the air of some buildings constructed before the 1939 year, in the buildings constructed after 1945 year with the traditional use of the bricks and in the buildings constructed with the use of great prefabricated plates are presented. The relations between radon-222 concentrations in the basements and in the first floor flats situated above the basement were evaluated. Based on the mean radon concentrations in the air of the various types of buildings investigated the effective doses for the inhabitants of each type of buildings were estimated. (author)

  10. 222Rn, 226Ra, and U in drinking water in Hungary

    International Nuclear Information System (INIS)

    Szerbin, P.; Koeteles, G.

    2002-01-01

    Among radionuclides ingested by drinking water the most important ones are radon, radium and uranium, causing radiation exposure of the lungs, bones, and gastro-intestinal organs, mainly kidneys. For this reason, as a part of the National Environmental Health Program to determine the main risk factors of the Hungarian population from environmental substances, 222 Rn, 226 Ra, and U concentrations were measured in domestic water supplies. Water samples were taken from all of the 19 Hungarian counties. Three cities were chosen from each county by the criteria of number of the population. Samples were taken from the communal drinking water supplies. Radon was determined by short lived daughter products using scintillation technique after water degassing into Lucas cells. Radium and uranium were determined after chemical separation, by Lucas scintillation method and by liquid scintillation technique. The obtained results were compared to the available literature data. Radioactivity levels were assessed for conformity with the Hungarian standards, WHO guidelines, and used for dose calculations. It was concluded that the radioactivity of the drinking water in Hungary is in the order of magnitude of the worldwide average. The measured radioactivity levels never exceeded the limits of the valid Hungarian standards for annual intake limits and were adequate to WHO guidelines. It was found that public doses from radon, radium, and uranium ingestion by drinking water were 12.7, 8.8, and 7.3 μSv y -1 , respectively. Summarizing the results of the survey it was concluded that comparing these doses to the public dose from other natural sources of radiation are negligibly small. (author)

  11. High flux operation of microstrip gas chambers on glass and plastic supports

    International Nuclear Information System (INIS)

    Bouclier, R.; Florent, J.J.; Gaudaen, J.; Millon, G.; Pasta, A.; Ropelewski, L.; Sauli, F.; Shekhtman, L.I.

    1992-01-01

    Recent observations on microstrip gas chambers realized on various glass and plastic supports are presented in this paper. Short term measurements indicate a rate capability up to and above 5x10 5 counts/s mm 2 . A long term exposure to radiation shows however gain modifications, dependent on the resistivity of the chamber substrate; a choice of low resistivity supports minimizes this effect. (orig.)

  12. Accuracy evaluation of the prescribed calibration factors for ionisation chambers belonging to radiotherapy centres

    International Nuclear Information System (INIS)

    Mohd Taufik Dolah; Supian Samat; Taiman Kadni

    1999-01-01

    Air kerma and exposure calibration factors of 14 ionisation chambers belonging to ten local radiotherapy centres have been determined by SSDL in the recent last ten month (1/10/1998 - 31/7/1999). The results obtained were compared either with previous SSDL results, or the chambers certificate values. The range of the percentage deviations obtained was -1.70% to 1.18%, which lies between the IAEA accepted value of range ±3.5%. (author)

  13. Distributed drift chamber design for rare particle detection in relativistic heavy ion collisions

    CERN Document Server

    Bellwied, R; Bernardo, V; Caines, H; Christie, W; Costa, S; Crawford, H J; Cronqvist, M; Debbe, R; Dinnwiddie, R; Engelage, J; Flores, I; Fuzesy, R Z; Greiner, L; Hallman, T; Hoffmann, G; Huang, H Z; Jensen, P; Judd, E G; Kainz, K; Kaplan, M; Kelly, S; Lindstrom, P J; Llope, W J; Lo Curto, G; Longacre, R; Milosevich, Z; Mitchell, J T; Mitchell, J W; Mogavero, E; Mutchler, G S; Paganis, S; Platner, E; Potenza, R; Rotondo, F; Russ, D; Sakrejda, I; Saulys, A; Schambach, J; Sheen, J; Smirnoff, N; Stokely, C L; Tang, J; Trattner, A L; Trentalange, S; Visser, G; Whitfield, J P; Witharm, F; Witharm, R; Wright, M

    2002-01-01

    This report describes a multi plane drift chamber that was designed and constructed to function as a topological detector for the BNL AGS E896 rare particle experiment. The chamber was optimized for good spatial resolution, two track separation, and a high uniform efficiency while operating in a 1.6 T magnetic field and subjected to long term exposure from a 11.6 GeV/nucleon beam of 10 sup 6 Au ions per second.

  14. The problems of individual monitoring for internal exposure of monazite storage facility workers

    International Nuclear Information System (INIS)

    Ekidin, A.; Kirdin, I.; Yarmoshenko, I.; Zhukovsky, M.

    2006-01-01

    traditionally two situations of internal inhalation exposure by alpha emitting nuclides are considered in radiological protection: occupational exposure due to inhalation of plutonium aerosols; inhalation exposure by 222 Rn daughters in working places and in home. for these situations the problems of radioactive aerosols intake, nuclide dynamics in human body, internal dosimetry, nuclide excretion, monitoring of internal exposure have been investigated in details especially for plutonium inhalation exposure. The results of these studies are presented in details in ICRP Publications and UNSCEAR reports. However there is very specific case in which the special analysis of internal inhalation exposure is need. it is the working places with anomalous, extremely high concentration of thoron ( 220 Rn) daughters. The problems of internal radiation exposure of workers in such working place are the main topic of this publication. (authors)

  15. QUALIDADE AMBIENTAL DO RESERVATÓRIO CAJÁ, TABOLEIRO GRANDE (RN

    Directory of Open Access Journals (Sweden)

    Francisco Ericardo do Nascimento

    2016-07-01

    Full Text Available O reservatório Cajá é o manancial responsável por abastecer a cidade de Taboleiro Grande mas, atualmente, sofre com alguns problemas relacionados ao uso e ocupação do entorno, além da diminuição do volume em função da baixa precipitação pluviométrica na região do Alto Oeste Potiguar. O objetivo deste trabalho foi realizar uma análise da qualidade ambiental do reservatório Cajá, localizado no município de Taboleiro Grande (RN. A metodologia de abordagem consistiu em leitura de parâmetros de qualidade de água com aparelho multiparâmetro, levantamento pontuais de impactos ambientais, e entrevistas com a população local sobre questões relacionadas ao uso e qualidade das águas do reservatório, tendo como principal foco a percepção ambiental dos munícipes. Os parâmetros utilizados para analisar a qualidade das águas foram: Temperatura, pH, Oxigênio Dissolvido e Condutividade Elétrica. Estabeleceram-se dois pontos no reservatório, onde as leituras foram realizadas em dois períodos sazonais, isto é, na estação seca e chuvosa. O resultado das análises mostrou que o OD e CE não apresentaram os índices estabelecidos pelo CONAMA 357/2005 para o consumo da água para o ser humano. Foram identificadas também algumas fontes que contribuem para a degradação da qualidade da água do manancial

  16. Potential design modifications for the High Yield Lithium Injection Fusion Energy (HYLIFE) reaction chamber

    International Nuclear Information System (INIS)

    Pitts, J.H.; Hovingh, J.; Meier, W.R.; Monsler, M.J.; Powell, E.G.; Walker, P.E.

    1979-01-01

    Generation of electric power from inertial confinement fusion requires a reaction chamber. One promising type, the High Yield Lithium Injection Fusion Energy (HYLIFE) chamber, includes a falling array of liquid lithium jets. These jets act as: (1) a renewable first wall and blanket to shield metal components from x-ray and neutron exposure, (2) a tritium breeder to replace tritium burned during the fusion process, and (3) an absorber and transfer medium for fusion energy. Over 90% of the energy produced in the reaction chamber is absorbed in the lithium jet fall. Design aspects are included

  17. Properties of electret ionization chambers for routine dosimetry in photon radiation fields

    International Nuclear Information System (INIS)

    Doerschel, B.; Pretzsch, G.

    1985-01-01

    The main properties of photon routine dosemeters are their energy and angular dependence as well as their measuring range and accuracy. The determination of radiation exposure from dosemeter response is based on the choice of an appropriate conversion factor taking into account the influence of body backscattering on the dosemeter response. Measuring range and accuracy of an electret ionization chamber first of all depend on electret stability, methods of charge measurement, and geometry of the chamber. The dosemeter performance is described for an electret ionization chamber which was designed for application to routine monitoring of radiation workers. (author)

  18. Properties of an electret ionisation chamber for individual dosimetry in photon radiation fields

    International Nuclear Information System (INIS)

    Doerschel, B.; Pretzsch, G.

    1985-01-01

    The main properties of individual photon dosemeters are their energy and angular dependence and their measuring range and measurement accuracy. The determination of radiation exposure from the dosemeter readout is based on the choice of appropriate conversion factors, taking into account the influence of body backscatter on the dosemeter readout. The measurement range and accuracy of an electret ionisation chamber primarily depend on the electret stability and charge state measurement as well as on the chamber geometry. Dosimetric properties are described for an electret ionisation chamber designed for personnel monitoring. (author)

  19. Uptake of the natural radioactive gas radon by an epiphytic plant.

    Science.gov (United States)

    Li, Peng; Zhang, Ruiwen; Gu, Mintian; Zheng, Guiling

    2018-01-15

    Radon ( 222 Rn) is a natural radioactive gas and the major radioactive contributor to human exposure. The present effective ways to control Rn contamination are ventilation and adsorption with activated carbon. Plants are believed to be negligible in reducing airborne Rn. Here, we found epiphytic Tillandsia brachycaulos (Bromeliaceae) was effective in reducing airborne Rn via the leaves. Rn concentrations in the Rn chamber after Tillandsia plant treatments decreased more than those in the natural situation. The specialized foliar trichomes densely covering Tillandsia leaves play a major role in the uptake of Rn because the amplified rough leaf surface area facilitates deposition of Rn progeny particles and the powdery epicuticular wax layer of foliar trichomes uptakes liposoluble Rn. The results provide us a new ecological strategy for Rn contamination control, and movable epiphytic Tillandsia plants can be applied widely in Rn removal systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. A PEGADA ECOLÓGICA DO CONSUMO DE ÁGUA DO MUNICÍPIO DE CAICÓ/RN

    Directory of Open Access Journals (Sweden)

    Milenna Dantas Lacava de Almeida

    2011-03-01

    Full Text Available A depleção dos recursos naturais acometidos pelas atividades antrópicas continuam ocorrendo de maneira desenfreada, por mais que as pesquisas e discussões sobre o tema sustentabilidade tenham, ao longo dos últimos anos, se popularizado. Mas, o homem ainda persiste em deixar suas pegadas. A Pegada Ecológica (PE, proposta por Ress e Wackernagel (1962 e, mais a frente, adaptada por Dias (2006 e Bellen (2008, surge como um instrumento de avaliação da sustentabilidade de um determinado local a partir dos cálculos de consumo de itens individualizados. A mudança dos padrões climáticos, a semi-aridez e as implicações decorrentes da agricultura familiar, são um alerta da exaustão do atual modelo de produção e consumo adotados pelas pessoas de uma dada área territorial ou de um município. Percebendo a necessidade de mensurar essa exaustão, o estudo em tela objetiva calcular a pegada ecológica do consumo de água do município de Caicó/RN, por entender que a disponibilidade hídrica da região é um dos principais itens causadores da insustentabilidade local. Para isso, utiliza-se uma metodologia fundamentada, principalmente, por Parente (2007 e Chambers et al. (2000, a partir de dados secundários fornecidos pelo Instituto Brasileiro de Geografia e Estatística (IBGE e a Companhia de Águas e Esgotos do Rio Grande do Norte (CAERN, em que se calculou a Pegada Ecológica com base no consumo de água das pessoas do município de Caicó/RN. Dessa forma, conclui-se que apenas para o consumo de água são necessários 966,835715 hectares globais de terra para suportar os fluxos de entrada e saída da região. Contudo, trata-se de um sinal de alerta, propondo-se uma urgente conscientização popular, a partir de práticas de educação ambiental no município e de ações efetivas do poder público local. PALAVRAS-CHAVE: Pegada Ecológica, Sustentabilidade, Caicó, Disponibilidade Hídrica.