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

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

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)

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

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.

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)

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

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.)

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)

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

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

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.

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

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.

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)

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

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)

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.)

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

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

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)

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.)

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

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.

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.)

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

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

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.

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

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.

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

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)

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.

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.

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

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.

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.

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.)

Determination of the characteristic limits and responses of nuclear track detectors in mixed radon and thoron atmospheres

International Nuclear Information System (INIS)

Röttger, Annette; Honig, Anja; Schrammel, Dieter; Strauss, Heinrich F.

2016-01-01

Closed nuclear track detectors are widely used for the determination of Rn-222 exposures. There are also partial open systems available, which are specially designed for the determination of the exposure to Rn-220, which is a relevant exposure in special workplaces or in specific regions of the world. This paper presents data and a detail analysis of how to determine the cross-correlation by calibration in pure Rn-222 and pure Rn-220 atm. By these means calibration coefficients for the analysis of real mixed atmospheres can be obtained. The respective decision threshold, detection limit and limits of the confidence interval were determined according to ISO 11929 (ISO 11929:2010, 2010). The exposure of detectors was performed at the radon reference chamber and the thoron progeny chamber of the Physikalisch-Technische Bundesanstalt (PTB). The analysis of track response was done at Parc RGM, while the analytical routines were developed in the Leibniz University Hanover, Institute Radioökologie und Strahlenschutz IRS at the working Group AK SIGMA (Arbeitskreis Nachweisgrenzen). - Highlights: • Analysis of exposure in reference atmospheres according ISO 11929. • Calibration of nuclear track detectors for 222 Rn and 220 Rn. • Calculation of cross-correlation by calibration in pure 222 Rn and 220 Rn atmospheres. • Thoron activity concentration should not be omitted in radon exposure determinations.

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.

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)

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

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

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

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

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

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.

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)

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

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

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

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

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

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)

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)

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

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.

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 ...

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)

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

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....

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

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

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.

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)

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)

A new passive radon-thoron discriminative measurement system

International Nuclear Information System (INIS)

Sciocchetti, G.; Sciocchetti, A.; Giovannoli, P.; DeFelice, P.; Cardellini, F.; Cotellessa, G.; Pagliari, M.

2010-01-01

A new passive radon-thoron discriminative measurement system has been developed for monitoring radon and thoron individually. It consists of a 'couple' of passive integrating devices with a CR39 nuclear track detector (NTD). The experimental prototype is based on the application of a new concept of NTD instrument developed at ENEA, named Alpha-PREM, acronym of piston radon exposure meter, which allows controlling the detector exposure with a patented sampling technique (Int. Eu. Pat. and US Pat.). The 'twin diffusion chambers system' was based on two A-PREM devices consisting of the standard device, named NTD-Rn, and a modified version, named NTD-Rn/Tn, which was set up to improve thoron sampling efficiency of the diffusion chamber, without changing the geometry and the start/stop function of the NTD-Rn device. Coupling devices fitted on each device allowed getting a system, which works as a double-chamber structure when deployed at the monitoring position. In this paper both technical and physical aspects are considered. (authors)

A new passive radon-thoron discriminative measurement system.

Science.gov (United States)

Sciocchetti, G; Sciocchetti, A; Giovannoli, P; DeFelice, P; Cardellini, F; Cotellessa, G; Pagliari, M

2010-10-01

A new passive radon-thoron discriminative measurement system has been developed for monitoring radon and thoron individually. It consists of a 'couple' of passive integrating devices with a CR39 nuclear track detector (NTD). The experimental prototype is based on the application of a new concept of NTD instrument developed at ENEA, named Alpha-PREM, acronym of piston radon exposure meter, which allows controlling the detector exposure with a patented sampling technique (Int. Eu. Pat. and US Pat.). The 'twin diffusion chambers system' was based on two A-PREM devices consisting of the standard device, named NTD-Rn, and a modified version, named NTD-Rn/Tn, which was set up to improve thoron sampling efficiency of the diffusion chamber, without changing the geometry and the start/stop function of the NTD-Rn device. Coupling devices fitted on each device allowed getting a system, which works as a double-chamber structure when deployed at the monitoring position. In this paper both technical and physical aspects are considered.

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

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)

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)

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)

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 ...

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)

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

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

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

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

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)

A performance evaluation study of three types of alpha-track detector radon monitors

International Nuclear Information System (INIS)

Yeager, W.M.; Lucas, R.M.; Daum, K.A.; Sensintaffar, E.; Poppell, S.; Feldt, L.; Clarkin, M.

1991-01-01

Three models of alpha-track detector (ATD) Rn monitors were exposed in Environmental Protection Agency (EPA) Rn chambers to obtain estimates of precision and bias for the National Residential Radon Survey (NRRS). Exposures in this study ranged from 37 to 740 Bq y m-3 (1 to 20 pCi y L-1), plus blanks. These exposures correspond to the range expected in most U.S. residences. All detectors were purchased through a Rn mitigation firm to assure that the vendors did not give special attention to the ATDs used in this study. Ten ATDs of each model were studied at 12 exposures. The mean and standard deviation of the reported values for each model were calculated and compared with the continuously monitored chamber concentrations to determine the bias and precision at each exposure. Results of this analysis were discussed with the vendors, who took corrective actions. Changes in track counting procedures and calibrations improved detector performance. Readings of one detector were adjusted based on a regression of the monitored values on the reported values

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)

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...

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...

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....

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...

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)

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.

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

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...

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

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

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

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

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.

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)

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)

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.

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)

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.)

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)

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

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.

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)

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

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...

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....

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.

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.)

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

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.

(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.

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

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

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.

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.

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.)

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.

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)

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.

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.

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.

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...

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

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)

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

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

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

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

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)

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)

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.

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

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

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

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

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)

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.

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.

{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)

Jørn 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....

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....

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)

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

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.

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.

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.

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

Mathematical model of radon activity measurements

Energy Technology Data Exchange (ETDEWEB)

Paschuk, Sergei A.; Correa, Janine N.; Kappke, Jaqueline; Zambianchi, Pedro, E-mail: sergei@utfpr.edu.br, E-mail: janine_nicolosi@hotmail.com [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Denyak, Valeriy, E-mail: denyak@gmail.com [Instituto de Pesquisa Pele Pequeno Principe, Curitiba, PR (Brazil)

2015-07-01

Present work describes a mathematical model that quantifies the time dependent amount of {sup 222}Rn and {sup 220}Rn altogether and their activities within an ionization chamber as, for example, AlphaGUARD, which is used to measure activity concentration of Rn in soil gas. The differential equations take into account tree main processes, namely: the injection of Rn into the cavity of detector by the air pump including the effect of the traveling time Rn takes to reach the chamber; Rn release by the air exiting the chamber; and radioactive decay of Rn within the chamber. Developed code quantifies the activity of {sup 222}Rn and {sup 220}Rn isotopes separately. Following the standard methodology to measure Rn activity in soil gas, the air pump usually is turned off over a period of time in order to avoid the influx of Rn into the chamber. Since {sup 220}Rn has a short half-life time, approximately 56s, the model shows that after 7 minutes the activity concentration of this isotope is null. Consequently, the measured activity refers to {sup 222}Rn, only. Furthermore, the model also addresses the activity of {sup 220}Rn and {sup 222}Rn progeny, which being metals represent potential risk of ionization chamber contamination that could increase the background of further measurements. Some preliminary comparison of experimental data and theoretical calculations is presented. Obtained transient and steady-state solutions could be used for planning of Rn in soil gas measurements as well as for accuracy assessment of obtained results together with efficiency evaluation of chosen measurements procedure. (author)

Børn 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....

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)

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

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.

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.

Jørn 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....

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)

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)

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.

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

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.

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)

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

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.)

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

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

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

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.

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.

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)

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.

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

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...

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)

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.

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

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.

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

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

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.)

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....

222Rn and 220Rn concentrations measured in various natural honey samples by using nuclear track detectors and resulting radiation doses to the members of the rural populations in Morocco

International Nuclear Information System (INIS)

Misdaq, M. A.; Mortassim, A.

2008-01-01

Radon ( 222 Rn) and thoron ( 220 Rn) concentrations were measured in sixteen natural honey material samples collected from different regions in Morocco by using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs). The concentrations of these radionuclides were also measured in nectar solutions corresponding to the studied honey samples. The measured concentrations of 222 Rn and 220 Rn in honey samples ranged from (2.3 ± 0.2) to (8.1 ± 0.6) Bq.l -1 and (1.8 ± 0.1) to (3.9 ± 0.3) Bq.l -1 , respectively. Committed equivalent doses due to annual intakes of 222 Rn were evaluated in the human gastrointestinal tract compartments of adult members of the Moroccan populations from the ingestion of studied honey samples. The influence of the target tissue mass and activities due to 222 Rn on the annual committed equivalent doses in the compartments of the human gastrointestinal tract was investigated. (authors)

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)

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

Radon concentration in dwellings in Aomori Prefecture, Japan

International Nuclear Information System (INIS)

Iyogi, T.; Ueda, S.; Hisamatsu, S.; Kondo, K.; Nakamura, Y.; Tsuji, N.; Mitsubishi Heavy Industries Ltd., Kobe

2002-01-01

To obtain an average dose from 222 Rn to the people in Aomori Prefecture where the first Japan's nuclear fuel cycling facilities are now under construction, we surveyed 222 Rn concentrations in 109 dwellings in the Prefecture from 1992 to 1996. The outdoor 222 Rn concentrations were also measured in gardens of 15 dwellings. The 222 Rn concentrations were measured with passive 222 Rn detectors which used a polycarbonate film for counting α-ray and could separate concentrations of 222 Rn from 220 Rn. Counting efficiencies of the detectors were calibrated with a standard 222 Rn chamber in the Environmental Measurement Laboratory in USA and in the National Radiological Protection Board in UK. Geometric means of 222 Rn concentration were 13 and 4.4 Bq x m -3 in the dwellings and outdoor, respectively. These values were consistent to nationwide survey results in Japan. The 222 Rn concentrations in the dwellings depended on their age. The concentrations were higher in recent dwellings than in older ones. The radiation dose from 222 Rn was estimated, taking into account the occupancy factor for inside and outside of dwellings. The annual dose was 0.32 mSv x y -1 , and 99% of the dose came from the exposure to 222 Rn inside the dwelling. (author)

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....

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

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

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.

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

From Vulnerability to Dignity: The RN Declaration of Self-Esteem.

Science.gov (United States)

Janzen, Katherine J; Mitchell, Maureen; Renton, Lesley J; Currie, Genevieve; Nordstrom, Pamela M

2015-11-04

Registered nurses (RNs) experience vulnerability from a variety of sources in today's healthcare organizations. While RN vulnerability can be associated with positive outcomes with patients and clients, vulnerability can also be dangerous to RNs as they struggle with outside forces that many feel they have no control over. The study aims to maintain and enhance the dignity of RNs and provide a beacon to RNs who may have become wounded in the healthcare setting and/or their own profession. The study was conducted in a conference entitled "Advancing Nursing Practice Through Change, Innovation and Creativity" held at a midsized university in western Canada. The participants were 115 administrators, members of RN regulatory bodies, nursing faculty, nurse educators, and staff nurses. An activity entitled "Wild Thinking" gave participants an opportunity to reflect upon the conference and their personal experiences of change, innovation, and creativity they wished to see within the workplace. All responses were collected at the end of the activity, transcribed verbatim, and analyzed for themes. Arising from 16 themes, the RN Declaration of Self-Esteem was created. The RN Declaration of Self-Esteem may be helpful in promoting empowerment at the individual RN level as well as in the collective professional level. © 2015 Wiley Periodicals, Inc.

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

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...

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.

Etched track radiometers in radon measurements: a review

CERN Document Server

Nikolaev, V A

1999-01-01

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

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.

Børn på YouTube – nydelse og nørderi

DEFF Research Database (Denmark)

Johansen, Stine Liv

2017-01-01

Mange børn og unge bruger dagligt adskillige timer på videodelingsplatformen YouTube. Her kan de dyrke deres individuelle interesser, deres ’guilty pleasures’ og følge med i youtuberes dagligliv. For mange børn og unge er muligheden for selv at producere indhold ligeledes en relevant del af...... attraktionen ved YouTube. På baggrund af en igangværende, kvalitativ undersøgelse præsenteres i denne artikel en række relevante perspektiver ved børn og unges brug af YouTube. Et væsentligt aspekt er, at voksne sjældent involverer sig i børn og unges brug af YouTube. Men hvis man ønsker at tage aktivt del...... børn og unges (digitale) dannelsesprocesser kan det godt betale sig at holde øje med, hvad de laver på YouTube – og forsøge at forstå, hvad de får ud af det....

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

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...

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...

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)

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.)

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

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.

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.) ...

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)

Eighty percent by 2020: the present and future of RN-to-BSN education.

Science.gov (United States)

McEwen, Melanie; Pullis, Bridgette R; White, Mary Joe; Krawtz, Susan

2013-10-01

More than 600 RN-to-BSN programs currently exist in the United States, and the numbers of programs and students are growing rapidly. This unprecedented growth is a result of several factors, including the Institute of Medicine's recommendation that 80% of RNs be BSN prepared by 2020. This survey was undertaken to explore key ideas and issues related to RN-to-BSN education to gather information on how RN-to-BSN programs are changing and to uncover concerns posited by program directors. The survey indicated that lack of standardization has resulted in significant variability in expectations and requirements among RN-to-BSN programs. Further, numerous questions need to be answered and concerns addressed to develop strategies to maintain growth, improve access, and remove barriers without sacrificing quality. Findings can be used to ensure that RN-to-BSN education prepares graduates for the future health care system and that the outcome is not just a piece of paper. Copyright 2013, SLACK Incorporated.

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.)

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.)

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

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)

Indsats for forældre til børn med ADHD

DEFF Research Database (Denmark)

Neubert, Katja

2012-01-01

Et nyt review, udarbejdet af forskergruppen omkring Morris Zwi, undersøger om interventionsprogrammer til forældre til børn med ADHD er effektive, når det gælder reducering af børnenes ADHD-relaterede adfærd og associerede problemer som eksempelvis indlæringsproblemer. Reviewet peger på, at en...... indsats til forældre til børn med ADHD kan have en gavnlig effekt på børnenes adfærd. Interventionen kan også være med til at sænke stressniveauet hos forældre til disse børn, og forbedre forældrenes selvtillid....

Optimizing measurement sensitivity to facilitate monitoring environmental levels of Rn-daughter concentrations

International Nuclear Information System (INIS)

Keefe, D.J.; McDowell, W.P.; Groer, P.G.; Witek, R.T.

1977-01-01

In the measurement of environmental levels of radioactivity, the primary problem is the accumulation of a statistically meaningful number of counts within a reasonable period of time. In the case of measurements of airborne 222 Rn-daughter concentrations, the problem is further complicated by the particularly short half-life, 3.05 minutes, of RaA (Po 218 ). Since the Rn-daughters, (RaA, RaB [Pb 214 ] and RaC [Bi 214 ]) are of interest, the equations interrelating these Rn-daughter concentrations were derived from the laws of radioactive-series decay. These equations, although straightforward, are cumbersome to solve. To facilitate the efficient use of these equations, a computer program has been written which permits the calculation of Rn-daughter concentrations or expected counts for a given set of measurement parameters (flow rate and detector efficiencies). A subroutine then calculates the optimum pumping and counting times required to provide the number of counts necessary for acceptable statistics at environmental levels of 222 Rn-daughter concentrations. This subroutine contains a set of parameters, flow rate and efficiencies, that are fixed using realistic restrictions. The use of these optimized pumping and counting times results in maximum measurement sensitivity under realistic constraints

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)

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

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...

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

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

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)

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

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...

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.

Exposure to radon and mortality standard in a coal miner cohort in Brazil

International Nuclear Information System (INIS)

Veiga, Lene Holanda Sadler; Amaral, Eliana; Koifman, Sergio

2002-01-01

High levels of radon and his products have been found at a underground coal mine, at the Southern Brazil, in operation since 1945. The 222 Rn concentration levels measured were 7000 Bq/m 3 and 0.7 WL for the radon sons (7.7 WLM/year), which are values considered higher than the limits for intervention in a working environments (500 to 1500 Bq/m3 of 222 Rn) and the occupational exposure limit (4.0 WLM/year). Due to the unique opportunity found in these miner group, it was decided to construct a cohort with miners from that mining (underground and surface) viewing the evaluation of the possible effects to the health decurrens from that exposure

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

Radon level in China and elevated indoor exposure in carbon brick and cave dwellings

International Nuclear Information System (INIS)

Wang Zuoyuan

1992-01-01

A nation wide survey of Chinese houses was conducted to determine the average annual effective dose to Chinese population from exposure to radon and its daughter products. The indoor and outdoor concentrations of radon and its daughters were measured using scintillation flask, two filter and carbon canister methods, as well as modified Tsivoglou methods for Rn daughters. Average Rn concentrations are 26.2Bqm -3 and 13.5Bqm -3 for indoor and outdoor environment, respectively. Potential alpha energy concentration, indoor is 744 x 10 -10 Jm -3 , outdoor is 511 x 10 -10 Jm -3 . Equilibrium Factor of Rn daughters are 0.49 (indoor) and 0.61 (outdoor). Occupancy Factor is 0.77 and 0.23. Using appropriate conversion factors, the annual average effective dose to Chinese population is 0.967 mSv. And also, the indoor Rn concentration and gamma dose rate were surveyed in two rural Provinces: Gansu and Jianxi. The fact was found that lung cancer mortality of population lived in high Rn level dwellings is higher than in control groups. An epidemiological retrospective case-control study is recommended in houses with high Rn level. (author)

222Rn levels in Kingsville, Texas, and vicinity near an in situ uranium mine

International Nuclear Information System (INIS)

McGehee, T.L.; Martino, M.R.; Harr, T.L.; Samudio, A.

1994-01-01

An investigation of the 222 Rn levels in ground water, soils, and indoor air has disclosed two 222 Rn ground-water anomalies in the Kingsville, Texas, area from uranium-enriched sandstones of the Evangeline aquifer. Indoor air 222 Rn levels were measured in summer 1991 (from undetectable to 3.2 pCi/l) and winter 1991-1992 (0.01 to 3.98 pCi/l) to determine seasonal extremes and risk to the public. Soil 222 Rn concentration maps ranging from undetectable to 75.4 pCi/l correlate to the low levels found in homes. Results of this study are based on analyses of 218 water samples, 52 in situ soil samples, and 104 indoor air samples. Water samples were injected into a scintillation mix (EPA/EERF-Manual-78-1) and analyzed by liquid scintillation techniques. Indoor air and soil samples were collected using passive charcoal canisters and analyzed by gamma-ray detection techniques (EPA 520/5-87-005). One ground-water 222 Rn anomaly lies near the permitted boundary of a large uranium deposit that is being mined. Private wells near the ore body yielded, 1,023 to 23,256 pCi/l at the well head. A second anomaly is located 2.5 mi (4 km) north of the uranium ore body near Naval Air Station, Kingsville. Private water wells in this area yielded 442 to 1,950 pCi/l 222 Rn at the well head. The radon anomalies are related to subsurface mineralization, which is one of the known natural geologic hazards of this area. Indoor air 222 Rn levels are well below the U.S. Environmental Protection Agency (US/EPA) action limit of 4 pCi/l. However, the high levels of 222 RN in ground water should be mitigated before entry into the home environment. High 222 Rn levels in ground water were reduced to background levels in household waters by use of a pre-introduction large-capacity holding tank

Dry soil diurnal quasi-periodic oscillations in soil 222Rn concentrations

International Nuclear Information System (INIS)

Tommasone Pascale, F.; De Francesco, S.; Carbone, P.; Cuoco, E.; Tedesco, D.

2014-01-01

222 Rn concentrations have been monitored during the dry season in August 2009 and August 2010, in a reworked alluvial-pyroclastic soil of the Pietramelara Plain, in Southern Italy, with the aim of determining the role of atmospheric factors in producing the quasi-periodic oscillations in soil 222 Rn concentrations reported in the literature. In this study we present the results of a detailed analysis and matching of soil 222 Rn concentrations, meteorological and solar parameters where the observed oscillations feature a characteristic behavior with second order build-up and depletion limbs, separated by a daily maximum and minimum. All these features are clearly shown to be tied to sunrise and sunset timings and environmental radiative flux regimes. Furthermore, a significant, and previously unreported, second order correlation (r 2  = 0.73) between daily maximum hourly global radiation and the daily range of soil 222 Rn concentrations has been detected, allowing estimates of the amplitude of these oscillations to be made from estimated or measured solar radiation data. The correlation has been found to be valid even in the presence of persistent patchy daytime cloudiness. In this case a daytime prolongation of the night-time build up stage and an attenuation or even suppression of daytime depletion is observed (a previously unreported effect). Neither soil cracking, nor precipitation, both suggested in some studies as causative factors for these oscillations, during the dry season appear to be necessary in explaining their occurrence. We also report the results of an artificial shading experiment, conducted in August 2009, that further support this conclusion. As soil 222 Rn concentrations during the dry season show a characteristic daily cycle, radon monitoring in soils under these conditions necessarily has to be gauged to the timings of the daily maximum and minimum, as well as to the eventual occurrence of cloudiness and to its related effects, in order to

Extreme levels of 222Rn and U in a private water supply

International Nuclear Information System (INIS)

Lowry, J.D.; Hoxie, D.C.; Moreau, E.

1987-01-01

In 1985, the Maine Department of Human Services discovered a private water supply in Leeds, ME, that contains over 40,700 BqL -1 (1.1 x 10 +6 pCil -1 ) of 222 Rn on average, and ranges between 13,300 and 59,200 Bql -1 . The well water also contains a gross alpha concentration of approximately 10.0 BqL -1 (270 pCiL -1 ), of which more than 95 percent is U (403 ugL -1 ). The ratio of 234 U to 238 U averages 1.17, which compares closely to the sea water at 1.14. The Ra content comprises less than 2 percent of the gross alpha. The levels of 222 Rn and U are considered to be extremely high, with the 222 Rn being the highest known level the authors are aware of for a drinking water supply. This area of Maine has geologic features characteristic of those shown by others to have a high potential for elevated levels of 222 Rn and other radioisotopes. The purpose of this paper is to update the information presented previously about this site, in particular to the ramifications on treatment alternatives associated with the presence of both 222 Rn and U in a water supply

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.

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...

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

{sup 222} Rn determination and physicochemical characteristic and biological in aquifers in the Toluca Valley; Determinacion de {sup 222} Rn y caracteristicas fisicoquimicas y biologicas en acuiferos del Valle de Toluca

Energy Technology Data Exchange (ETDEWEB)

Hernandez A, A

1998-10-01

Concentration levels of {sup 222} Rn and {sup 226} Rn have been analyzed in water samples from boreholes belonging to the drinking water supply system around Toluca, Mexico. The {sup 222} Rn source is the decay of {sup 226} Rn within the solid matrix of the aquifer. The study was performed during the dry and rainy seasons. {sup 222} Rn concentration was determined by the liquid scintillation technique, {sup 226} Rn was determined by gamma spectrometry, the physicochemical parameters and bacteriological analysis were performed by conventional chemical techniques. Solubilized trace elements were determined by Inductively Coupled Plasma - Mass Spectrometry (Icp-Ms). The radon level fluctuations at the boreholes in Toluca city and Almoloya spring indicated differences in the radon content. At borehole Lodos Prietos 2, the temperature and radon level were systematically the highest in comparison with the other boreholes and the spring indicating a contribution of a regional flow to the water of this particular borehole. The result for {sup 226} Rn, the average {sup 222} Rn observed during the sampling period, no correspondence occurs between the radium and the radon content indicating that, radon is not supported by radium, but is incorporated into the water through fissures in the rocks in contact with the water. The radon levels obtained in house faucets which water is supplied by boreholes decrease as a function of the distance from the source borehole to the house. With the chemical composition of each one of the studied boreholes and spring a Piper diagram was draw indicating the kind of water. The boreholes and spring can be classified as bicarbonate calcium/magnesium. Almost no fluctuation on time was observed in the chemical species and trace elements only a slight increase was observed at the end of the rain season. At Almoloya, spring pollution with coliform bacteria and nitrates showed an anthropogenic contribution to the water deterioration probable and

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

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.

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.

222Rn Determination In Drinking Waters - RAD7 And LSC Technique Comparison

International Nuclear Information System (INIS)

Todorovic, N.; Stojkovic, I.; Nikolov, J.; Tenjovic, B.

2015-01-01

A procedure for the determination of 222Rn in environmental water samples using liquid scintillation counting (LSC) was applied and optimized. For radon determination in drinking water from groundwater and surface water sources by LSC, the EPA Method 913.0 was used. A minimum detectable activity of 0.029 Bq L-1 in a 20 mL glass vial (10 mL water sample mixed with 10 mL of liquid scintillation cocktail) has been achieved during 300 minutes of measurement time. The procedure was compared with RAD7 radon detector measurements. Factors that affect the measurement accuracy and precision of RAD7 radon detector are the sampling technique, sample concentration, sample size, counting time, temperature, relative humidity and background effects. The minimal detectable activity (MDA) for RAD7 technique was found to be 0.1 Bq/L. From obtained results of 222Rn measurements in 15 water samples with different 222Rn activities, correlation between the two techniques applied for measurements of 222Rn in water samples (A less than 400 Bq/L) was determined. There is reasonable agreement (within statistical uncertainties) between the various techniques in most cases, while disagreements most likely come from systematic uncertainties associated with sampling procedures. Discrepancy in determined activities between the two techniques becomes more evident with increased 222Rn activities in water. LSC technique gives in general higher activity concentrations for about 30 percent than RAD7 spectrometer. The interpretation of shown results could be that RAD7 is not properly calibrated for higher activities, since USA reference level of 222Rn concentrations in water is only 11.1 Bq/L (US EPA, Proposed Radon in Drinking Water Regulation). (author).

Radon exposure, cigarette smoking, and other mining experience in the beaverlodge uranium miners cohort

International Nuclear Information System (INIS)

L'Abbe, K.A.; Howe, G.R.; Burch, J.D.; Miller, A.B.; Abbatt, J.; Band, P.; Choi, W.; Du, J.; Feather, J.; Gallagher, R.

1991-01-01

A nested case-control study within the Beaverlodge Uranium Miners Cohort was undertaken to assess any possible contribution of confounding by smoking and other mining experience to the risk estimate derived from the original cohort study. Next of kin have been interviewed for 46 lung cancer cases and 95 controls enrolled in the Beaverlodge Uranium Miners Cohort Study who died between 1950 and 1980. Confounding by cigarette smoking and other mining experience appears unlikely to have contributed to the relative risk coefficient for exposure to Rn decay products derived in the parent study. Data for smoking and exposure to Rn decay products are consistent with a multiplicative model, although considerable caution must be applied to this interpretation

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

Radon transport modelling: User's guide to RnMod3d

DEFF Research Database (Denmark)

Andersen, Claus Erik

2000-01-01

RnMod3d is a numerical computer model of soil-gas and radon transport in porous media. It can be used, for example, to study radon entry from soil into houses in response to indoor-outdoor pressure differences or changes in atmospheric pressure. It canalso be used for flux calculations of radon...... decay, diffusion and advection of radon can be solved. Moisture is included in the model, and partitioning ofradon between air, water and soil grains (adsorption) is taken into account. Most parameters can change in time and space, and transport parameters (diffusivity and permeability) may...... be anisotropic. This guide includes benchmark tests based on simpleproblems with known solutions. RnMod3d has also been part of an international model intercomparison exercise based on more complicated problems without known solutions. All tests show that RnMod3d gives results of good quality....

Børn, 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...

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...

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

Comparing NET and ERI standardized exam scores between baccalaureate graduates who pass or fail the NCLEX-RN.

Science.gov (United States)

Bondmass, Mary D; Moonie, Sheniz; Kowalski, Susan

2008-01-01

In the United States, nursing programs are commonly evaluated by their graduates success on the National Council Licensure Examination for Registered Nurses (NCLEX-RN). The purpose of this paper is to describe a change in NCLEX-RN success rates following the addition of standardized exams throughout our program's curriculum, and to compare these exam scores between graduates who pass NCLEX-RN and those who do not. Our results indicate an 8.5% change (p pass rate from our previous 5-year mean pass rate, and significant differences in standardized test scores for those who pass the NCLEX-RN compared to those who do not (p pass NCLEX-RN than not.

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.)

Björn Andersson – et liv for elevene, lærerne og naturfagene Björn Andersson – a life for students, teachers and science

Directory of Open Access Journals (Sweden)

Svein Sjøberg

2013-11-01

Full Text Available This article is written in memory of Professor Björn Andersson (1939-2013, the pioneer in the emerging field of science education research in Sweden. In 1976 he was the first to present a PhD in the field of science education in the Nordic countries, and later he became the first to hold a chair in this field in Sweden. The article lifts his PhD (Andersson, 1976 as an example for how a PhD should be written and argues that it should be re-read today. The theses has a clear purpose and research agenda, a well-argued theoretical foundation, a solid anchoring to classroom context, sound choices of methods, excellent analysis of empirical data, both qualitative and qualitative, and a clear presentation of findings and implications. In the decades that followed, Björn was the key person to build the field of science education research in Sweden. This article presents just a few aspects of his wide scope of interests and activities as they have unfolded on the national as well as on the international scene. Björn brought international perspectives to Sweden, and he also represented Sweden abroad. Now, nearly 40 years after Björn graduated, the field of science education in Sweden and the other Nordic countries is well established and flourishing. Björn combined a series of qualities and can serve as a model for new generations: a concern for the learner, teachers and their classroom activities, and a care for coworkers. He provides an example of how to combine an academic activity with a devotion to improve the quality of teaching and learning.

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

Ra-226 and Rn-222 in saline water compartments of the Aral Sea region

International Nuclear Information System (INIS)

Schettler, Georg; Oberhänsli, Hedi; Hahne, Knut

2015-01-01

Highlights: • 222 Rn and 226 Ra concentrations in different water compartments of the Aral Sea region. • 226 Ra-analysis based on 222 Rn-ingrowth versus MS-analysis after solid-phase extraction. • 226 Ra in different groundwater types of the Aral Sea Basin. • 222 Rn distribution in the Aral Sea, western basin. - Abstract: The Aral Sea has been shrinking since 1963 due to extensive irrigation and the corresponding decline in the river water inflow. Understanding of the current hydrological situation demands an improved understanding of the surface water/groundwater dynamics in the region. 222 Rn and 226 Ra measurements can be used to trace groundwater discharge into surface waters. Data of these radiometric parameters were not previously available for the study region. We determined 222 Rn activities after liquid phase extraction using Liquid Scintillation Counting (LSC) with peak-length discrimination and analyzed 226 Ra concentrations in different water compartments of the Amu Darya Delta (surface waters, unconfined groundwater, artesian water, and water profiles from the closed Large Aral Sea (western basin). The water samples comprise a salinity range between 1 and 263 g/l. The seasonal dynamics of solid/water interaction under an arid climate regime force the hydrochemical evolution of the unconfined groundwater in the Amu Darya Delta to high-salinity Na(Mg)Cl(SO 4 ) water types. The dissolved radium concentrations in the waters were mostly very low due to mineral over-saturation, extensive co-precipitation of radium and adsorption of radium on coexisting solid substrates. The analysis of very low 226 Ra concentrations (<10 ppq) at remote study sites is a challenge. We used the water samples to test and improve different analytical methods. In particular, we modified a procedure developed for the α-spectrometric determination of 226 Ra after solid phase extraction of radium using 3M Empore™ High Performance Extraction Disks (Purkl, 2002) for the

Occupational exposure of phosphate mine workers: airborne radioactivity measurements and dose assessment

International Nuclear Information System (INIS)

Khater, Ashraf E.; Hussein, M.A.; Hussein, Mohamed I.

2004-01-01

Under the Egyptian program for radiation safety and control, airborne radioactivity measurements and radiological dose assessment were conducted in some phosphate and uranium mines. Abu-Tartor mine is one of the biggest underground phosphate mines in Egypt. Airborne radioactivity, radon ( 222 Rn) and its short-lived decay products (progenies) and thoron ( 220 Rn), were measured in selected locations along the mine. The environmental gamma and workers dose equivalent rate (mSv/y) were measured inside and outside the mine using thermo-luminescence dosimeters (TLD). The results were presented and discussed. The calculated annual effective dose due to airborne radioactivity is the main source of occupational exposure and exceeding the maximum recommended level by ICRP-60 inside the mine tunnels. A number of recommendations are suggested to control the occupational exposures

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.

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

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

222 Rn determination and physicochemical characteristic and biological in aquifers in the Toluca Valley

International Nuclear Information System (INIS)

Hernandez A, A.

1998-01-01

Concentration levels of 222 Rn and 226 Rn have been analyzed in water samples from boreholes belonging to the drinking water supply system around Toluca, Mexico. The 222 Rn source is the decay of 226 Rn within the solid matrix of the aquifer. The study was performed during the dry and rainy seasons. 222 Rn concentration was determined by the liquid scintillation technique, 226 Rn was determined by gamma spectrometry, the physicochemical parameters and bacteriological analysis were performed by conventional chemical techniques. Solubilized trace elements were determined by Inductively Coupled Plasma - Mass Spectrometry (Icp-Ms). The radon level fluctuations at the boreholes in Toluca city and Almoloya spring indicated differences in the radon content. At borehole Lodos Prietos 2, the temperature and radon level were systematically the highest in comparison with the other boreholes and the spring indicating a contribution of a regional flow to the water of this particular borehole. The result for 226 Rn, the average 222 Rn observed during the sampling period, no correspondence occurs between the radium and the radon content indicating that, radon is not supported by radium, but is incorporated into the water through fissures in the rocks in contact with the water. The radon levels obtained in house faucets which water is supplied by boreholes decrease as a function of the distance from the source borehole to the house. With the chemical composition of each one of the studied boreholes and spring a Piper diagram was draw indicating the kind of water. The boreholes and spring can be classified as bicarbonate calcium/magnesium. Almost no fluctuation on time was observed in the chemical species and trace elements only a slight increase was observed at the end of the rain season. At Almoloya, spring pollution with coliform bacteria and nitrates showed an anthropogenic contribution to the water deterioration probable and fertilizers and detritus. Most of the studied water

Measurements of octupole collectivity in Rn and Ra nuclei using Coulomb excitation

CERN Multimedia

We propose to exploit the unique capability of HIE-ISOLDE to provide post-accelerated $^{221,222}$Rn and $^{222,226,228}$Ra ion beams for the study of octupole collectivity in these nuclei. We will measure E3 transition moments in $^{222}$Rn and $^{222,226,228}$Ra in order to fully map out the variation in E3 strength in the octupole mass region with Z$\\thicksim$88 and N$\\thicksim$134. This will validate model calculations that predict different behaviour as a function of N. We will also locate the position of the parity doublet partner of the ground state in $^{221}$Rn, in order to test the suitability of odd-A radon isotopes for EDM searches.

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.

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)

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.)

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)

222Rn in private well water in the vicinity of uranium mines over ten years

International Nuclear Information System (INIS)

Yunoki, Eiji; Kataoka, Toshio; Michihiro, Kenshu; Sugiyama, Hirokazu; Shimizu, Mitsuo; Mori, Tadashige

1994-01-01

There are many small uranium mines of the sedimentary type in Kamisaibara, Okayama Prefecture, Japan. As inhabitants in Kamisaibara consume water from privately-dug wells, it is important to investigate distributions of 222 Rn in privately-dug well water in the vicinity of the mines. The determination of 222 Rn in well water was carried out from April 1980 to October 1990. Though small in area (16 km 2 ), each well water has its own characteristic activity concentrations of 222 Rn. The activity concentrations of 222 Rn are almost constant for each specific well over a long period (about 10 years). In general, the correlation coefficients for several sampling points are small. As Akawase and Tennoh are situated in the same rock type, the correlation coefficient is the highest value in this area. The estimated dose equivalent for the human stomach is approximately 0.4-54 μSv/year. The type of distribution of 222 Rn in privately-dug well water is log normal. (author)

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...

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…

Evaluate transport processes in MERRA driven chemical transport models using updated 222Rn emission inventories and global observations

Science.gov (United States)

Zhang, B.; Liu, H.; Crawford, J. H.; Fairlie, T. D.; Chen, G.; Chambers, S. D.; Kang, C. H.; Williams, A. G.; Zhang, K.; Considine, D. B.; Payer Sulprizio, M.; Yantosca, R.

2015-12-01

Convective and synoptic processes play a major role in determining the transport and distribution of trace gases and aerosols in the troposphere. The representation of these processes in global models (at ~100-1000 km horizontal resolution) is challenging, because convection is a sub-grid process and needs to be parameterized, while synoptic processes are close to the grid scale. Depending on the parameterization schemes used in climate models, the role of convection in transporting trace gases and aerosols may vary from model to model. 222Rn is a chemically inert and radioactive gas constantly emitted from soil and has a half-life (3.8 days) comparable to synoptic timescale, which makes it an effective tracer for convective and synoptic transport. In this study, we evaluate the convective and synoptic transport in two chemical transport models (GMI and GEOS-Chem), both driven by the NASA's MERRA reanalysis. Considering the uncertainties in 222Rn emissions, we incorporate two more recent scenarios with regionally varying 222Rn emissions into GEOS-Chem/MERRA and compare the simulation results with those using the relatively uniform 222Rn emissions in the standard model. We evaluate the global distribution and seasonality of 222Rn concentrations simulated by the two models against an extended collection of 222Rn observations from 1970s to 2010s. The intercomparison will improve our understanding of the spatial variability in global 222Rn emissions, including the suspected excessive 222Rn emissions in East Asia, and provide useful feedbacks on 222Rn emission models. We will assess 222Rn vertical distributions at different latitudes in the models using observations at surface sites and in the upper troposphere and lower stratosphere. Results will be compared with previous models driven by other meteorological fields (e.g., fvGCM and GEOS4). Since the decay of 222Rn is the source of 210Pb, a useful radionuclide tracer attached to submicron aerosols, improved

The fundamentals of integrating service in a post-licensure RN to BSN program.

Science.gov (United States)

Washington-Brown, Linda; Ritchie, Arlene

2014-01-01

Integrating service in a post-licensure registered nurse to bachelor of science in nursing (RN to BSN) program provides licensed registered nurse (RN) students the opportunity to learn, develop, and experience different cultures while serving the community and populations in need (McKinnon & Fitzpatrick, 2012). Service to the community, integrated with academic learning can be applied in a wide variety of settings, including schools, universities, and community faith-based organizations. Academic service-learning (ASL) can involve a group of students, a classroom, or an entire school. In the RN to BSN program, the authors use a student-directed service learning approach that integrates service-learning throughout the curriculum. RN students are introduced to service-learning at program orientation prior to the start of classes and receive reinforcement and active engagement throughout the curriculum. The students and volunteer agencies receive and give benefits from the services provided and the life lessons gained through mentorship, education, and hands-on experiences.

Wall attenuation and scatter corrections for ion chambers: measurements versus calculations

Energy Technology Data Exchange (ETDEWEB)

Rogers, D W.O.; Bielajew, A F [National Research Council of Canada, Ottawa, ON (Canada). Div. of Physics

1990-08-01

In precision ion chamber dosimetry in air, wall attenuation and scatter are corrected for A{sub wall} (K{sub att} in IAEA terminology, K{sub w}{sup -1} in standards laboratory terminology). Using the EGS4 system the authors show that Monte Carlo calculated A{sub wall} factors predict relative variations in detector response with wall thickness which agree with all available experimental data within a statistical uncertainty of less than 0.1%. They calculated correction factors for use in exposure and air kerma standards are different by up to 1% from those obtained by extrapolating these same measurements. Using calculated correction factors would imply increases of 0.7-1.0% in the exposure and air kerma standards based on spherical and large diameter, large length cylindrical chambers and decreases of 0.3-0.5% for standards based on large diameter pancake chambers. (author).

The neonatal Fc receptor (FcRn) binds independently to both sites of the IgG homodimer with identical affinity.

Science.gov (United States)

Abdiche, Yasmina Noubia; Yeung, Yik Andy; Chaparro-Riggers, Javier; Barman, Ishita; Strop, Pavel; Chin, Sherman Michael; Pham, Amber; Bolton, Gary; McDonough, Dan; Lindquist, Kevin; Pons, Jaume; Rajpal, Arvind

2015-01-01

The neonatal Fc receptor (FcRn) is expressed by cells of epithelial, endothelial and myeloid lineages and performs multiple roles in adaptive immunity. Characterizing the FcRn/IgG interaction is fundamental to designing therapeutic antibodies because IgGs with moderately increased binding affinities for FcRn exhibit superior serum half-lives and efficacy. It has been hypothesized that 2 FcRn molecules bind an IgG homodimer with disparate affinities, yet their affinity constants are inconsistent across the literature. Using surface plasmon resonance biosensor assays that eliminated confounding experimental artifacts, we present data supporting an alternate hypothesis: 2 FcRn molecules saturate an IgG homodimer with identical affinities at independent sites, consistent with the symmetrical arrangement of the FcRn/Fc complex observed in the crystal structure published by Burmeister et al. in 1994. We find that human FcRn binds human IgG1 with an equilibrium dissociation constant (KD) of 760 ± 60 nM (N = 14) at 25°C and pH 5.8, and shows less than 25% variation across the other human subtypes. Human IgG1 binds cynomolgus monkey FcRn with a 2-fold higher affinity than human FcRn, and binds both mouse and rat FcRn with a 10-fold higher affinity than human FcRn. FcRn/IgG interactions from multiple species show less than a 2-fold weaker affinity at 37°C than at 25°C and appear independent of an IgG's variable region. Our in vivo data in mouse and rat models demonstrate that both affinity and avidity influence an IgG's serum half-life, which should be considered when choosing animals, especially transgenic systems, as surrogates.

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.)

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

A study of airborne radon levels in Paarl houses (South Africa) and associated source terms, using electret ion chambers and gamma-ray spectrometry

Energy Technology Data Exchange (ETDEWEB)

Lindsay, R. [Department of Physics, University of the Western Cape, Private Bag X17, Bellville 7537 (South Africa)], E-mail: rlindsay@uwc.ac.za; Newman, R.T. [Environmental Radioactivity Laboratory, Physics Group, iThemba LABS, P.O. Box 722, Somerset West 7129 (South Africa); Speelman, W.J. [Department of Physics, University of the Western Cape, Private Bag X17, Bellville 7537 (South Africa)

2008-11-15

Indoor radon ({sup 222}Rn) concentrations were measured in Paarl homes by means of electret ion chambers. The concentrations varied between 28 and 465 Bq m{sup -3}. The average values (Bq m{sup -3}) found in houses on the west and east side of the Berg River, which bisects Paarl, were 132 ({+-}11) and 37 ({+-}3), respectively. Radiometric analyses of soils show that the mean {sup 226}Ra activity concentration is three times higher on the west than on the east side of the Berg River.

A study of airborne radon levels in Paarl houses (South Africa) and associated source terms, using electret ion chambers and gamma-ray spectrometry

International Nuclear Information System (INIS)

Lindsay, R.; Newman, R.T.; Speelman, W.J.

2008-01-01

Indoor radon ( 222 Rn) concentrations were measured in Paarl homes by means of electret ion chambers. The concentrations varied between 28 and 465 Bq m -3 . The average values (Bq m -3 ) found in houses on the west and east side of the Berg River, which bisects Paarl, were 132 (±11) and 37 (±3), respectively. Radiometric analyses of soils show that the mean 226 Ra activity concentration is three times higher on the west than on the east side of the Berg River

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.

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

Design and operation of an automated beta-particle counting system for the measurement of 220Rn (and 222Rn) progeny

International Nuclear Information System (INIS)

Bigu, J.

1992-01-01

A fully automated system of the continuous (active) type has been designed for the unattended quantification of 222 Rn progeny and 220 Rn progeny in calibration and test facilities, as well as working and living environments. The system uses a β-particle detector and associated electronic circuitry, in conjunction with an in-house microprocessor-based processing interface card and a personal computer, operated by specially developed in-house software. The system represents a significant improvement over systems using α-particle detectors because of its enhanced flexibility of design and virtual elimination of plate-out effects in the sampling head, and of self-absorption phenomena in the sampling filter. The β-particle system was tested and calibrated in a Radon and Thoron Test Facility of the walk-in type under a variety of experimental conditions. (author)

Human IgG lacking effector functions demonstrate lower FcRn-binding and reduced transplacental transport.

Science.gov (United States)

Stapleton, Nigel M; Armstrong-Fisher, Sylvia S; Andersen, Jan Terje; van der Schoot, C Ellen; Porter, Charlene; Page, Kenneth R; Falconer, Donald; de Haas, Masja; Williamson, Lorna M; Clark, Michael R; Vidarsson, Gestur; Armour, Kathryn L

2018-03-01

We have previously generated human IgG1 antibodies that were engineered for reduced binding to the classical Fcγ receptors (FcγRI-III) and C1q, thereby eliminating their destructive effector functions (constant region G1Δnab). In their potential use as blocking agents, favorable binding to the neonatal Fc receptor (FcRn) is important to preserve the long half-life typical of IgG. An ability to cross the placenta, which is also mediated, at least in part, by FcRn is desirable in some indications, such as feto-maternal alloimmune disorders. Here, we show that G1Δnab mutants retain pH-dependent binding to human FcRn but that the amino acid alterations reduce the affinity of the IgG1:FcRn interaction by 2.0-fold and 1.6-fold for the two antibodies investigated. The transport of the modified G1Δnab mutants across monolayers of human cell lines expressing FcRn was approximately 75% of the wild-type, except that no difference was observed with human umbilical vein endothelial cells. G1Δnab mutation also reduced transport in an ex vivo placenta model. In conclusion, we demonstrate that, although the G1Δnab mutations are away from the FcRn-binding site, they have long-distance effects, modulating FcRn binding and transcellular transport. Our findings have implications for the design of therapeutic human IgG with tailored effector functions. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

A Concise Synthesis of Three Branches Derived from Polysaccharide RN1 and Anti-Pancreatic Cancer Activity Study

Directory of Open Access Journals (Sweden)

Deqin Cai

2017-10-01

Full Text Available RN1, a polysaccharide from flowers of Panax pseudo-ginsieng Wall. Var. notoginseng (Burkill Hoo & Tseng, is a potential multi-targeting drug candidate for pancreatic cancer treatment. However, the active targeting domain of RN1 is still unknown. Herein, three RN1 derived branches were synthesized via [3+2] or [2+2] strategies, efficiently. Two pentasaccharides, 18 and 27, showed similar inhibition effect on pancreatic cancer BxPC-3 cells to that of RN1 at same concentration. Interestingly, tetrasaccharide 21 potently inhibited gemcitabineresistant cell line Panc-1 at high concentration. These suggest that the branches of RN1 might be the active targeting domain and tetrasaccharide 21 might be a potential leading compound for pancreatic cancer with gemcitabine resistance.

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)

Influence of IL-1RN intron 2 variable number of tandem repeats (VNTR) polymorphism on bipolar disorder.

Science.gov (United States)

Rafiei, A; Hosseini, S H; Taheri, M; Hosseni-khah, Z; Hajilooi, M; Mazaheri, Z

2013-01-01

Several lines of evidence point to the role of neurobiological mechanisms and genetic background in bipolar disorder (BD). The interleukin-1 receptor antagonist (IL-1Ra) is the principal regulator of IL-1α and IL-1β bioactivities. This study aimed to investigate the potential role of the variable number of tandem repeats (VNTR) polymorphisms of the IL-1Ra gene (IL1RN) in conferring susceptibility to BD. In total, 217 patients meeting DSM-IV-TR criteria for BD and 212 controls were recruited for the study. Genotyping of IL1RN was determined by polymerase chain reaction amplification of VNTR of 86 base pairs in intron 2 of IL1RN. The genotype distribution of IL1RN polymorphism was significantly different between BD patients and controls. The IL1RN*1/2 genotype was more prevalent in BD patients than in controls (44.2 vs. 30.2%, p = 0.003). Multiple logistic regression analysis demonstrated that IL1RN*1/2 heterozygotes had a significantly higher risk for BD (OR 1.83 and 95% CI 1.22-2.74, p = 0.003). Further stratification of the BD patients into IL1RN*2 allele carrier and noncarrier subgroups revealed a strong association between IL1RN*2 carriage and prolongation of the disease (p = 0.02). These findings suggest a positive association between VNTR polymorphism in IL1RN and BD. Additional studies, particularly with a prospective approach, are necessary to clarify the precise role of the VNTR polymorphism on the disease in different ethnic populations. Copyright © 2013 S. Karger AG, Basel.

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.

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.

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)

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…

Levan-type fructooligosaccharide production using Bacillus licheniformis RN-01 levansucrase Y246S immobilized on chitosan beads

Directory of Open Access Journals (Sweden)

Surawut Sangmanee

2016-06-01

Full Text Available Bacillus licheniformis RN-01 levansucrase Y246S (LsRN-Y246S was immobilized by covalently linking onto chitosan, Sepabead EC-EP, and Sepabead EC-HFA, beads. The stability of immobilized LsRN-Y246S was found to be the highest with chitosan beads, retaining more than 70% activity after 13 weeks storage at 4 oC, and 68% activity after 12 hours incubation at 40°C. LsRN-Y246S immobilized on chitosan beads withstands sucrose concentrations up to 70% (w/v, retaining over 85% of its activity, significantly better than LsRN-Y246S immobilized on others supporting matrices. LsRN-Y246S immobilized on chitosan showed a 2.4 fold increase in activity in the presence of Mn2+, and gave slight protection against deactivation by of Cu2+, Zn2+, Fe3+, SDS and EDTA. A maximum of 8.36 g and an average of 7.35 g LFOS yield at least up to DP 11 can be produced from 25 g of sucrose, during five production cycles. We have demonstrated that LFOS can be effectively produced by chitosan immobilized LsRN-Y246S and purified.

Activated charcoal adsorber bed as a 222Rn hold up system for application in uranium mining industries

International Nuclear Information System (INIS)

Sudeep Kumara, K.; Karunakara, N.; Sahoo, B.K.; Gaware, J.J.; Sapra, B.K.; Mayya, Y.S.

2018-01-01

222 Rn, produced due to the decay of 226 Ra, can accumulate to high concentrations, and if adequate ventilation is not provided the workers may inhale the 222 Rn laden air, which would result in elevated inhalation dose in Uranium mining and milling operations. Similarly, in thorium mining and processing plants, the 220 Rn generated during monazite processing and thorium handling facility is of concern. In a previous publication it has been shown that adsorption in a flow-through charcoal bed offers an excellent method of alleviating the release of 220 Rn into occupational and public domain. In this paper we examine the utility of TMS as a 222 Rn hold up/delay system by evaluating its performance parameters such as breakthrough time (τ) and adsorption coefficient (K) at different flow rates

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

Assessment of uncertainty associated with measuring exposure to radon and decay products in the French uranium miners cohort

International Nuclear Information System (INIS)

Allodji, Rodrigue S; Leuraud, Klervi; Laurier, Dominique; Bernhard, Sylvain; Henry, Stéphane; Bénichou, Jacques

2012-01-01

The reliability of exposure data directly affects the reliability of the risk estimates derived from epidemiological studies. Measurement uncertainty must be known and understood before it can be corrected. The literature on occupational exposure to radon ( 222 Rn) and its decay products reveals only a few epidemiological studies in which uncertainty has been accounted for explicitly. This work examined the sources, nature, distribution and magnitude of uncertainty of the exposure of French uranium miners to radon ( 222 Rn) and its decay products. We estimated the total size of uncertainty for this exposure with the root sum square (RSS) method, which may be an alternative when repeated measures are not available. As a result, we identified six main sources of uncertainty. The total size of the uncertainty decreased from about 47% in the period 1956–1974 to 10% after 1982, illustrating the improvement in the radiological monitoring system over time.

Evaluation of radiation exposure from a consumer product. A pillow

International Nuclear Information System (INIS)

Furuta, Etsuko; Aburai, Tamaru

1999-01-01

Radiation exposure from a pillow was analyzed. According to an advertisement of the pillow, this radioactive consumer product contains enough amounts of radioactive materials to induce radiation hormesis effects. The pillow consists of the filling chips made from kneading mineral ores and the polynosic linings contains natural radioactive ores. A γ-ray analysis of the pillow using pure Ge-MCA reveals that there exist radioactivities of thorium and uranium series mixtures in it at concentration of 0.58% by the weight. The observations of a chip surface by a scanning electron microscope show that the shapes of two sides are different each other. There are lots of sharp protuberances on the outside of the chip. To determine the direct external exposures from the pillow, film badges were placed on the pillow for 210 h and 2555 h. The dose equivalents of 210 h exposure was under 0.1 mSv which is a detection limit of a γ-ray by the film badges. However, that of 2555 h exposure was over 0.1 mSv less than 0.15 mSv. Quantities of internal exposures from inhalation of the vaporized Rn were measured by a Lucas Cell. It was 79 Bq/m 3 . There is no necessity for anxious about being broken in health inhaling the Rn-gass. (author)

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)

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.

Glass implanted 210Po as a method of determination of long term exposure to radon: First experiments in Israel

International Nuclear Information System (INIS)

Haquin, G.; Lang, B.; Even, O.; Asael, Y.; Shamai, Y.; Margaliot, M.; Shirav, M.

2002-01-01

Radon gas ( 222 Rn) is known to be the major contributor of the total exposure of the population to ionizing radiation. Retrospective assessment techniques have been developed to estimate long term exposures to ( 222 Rn and its progeny in epidemiological studies. Measurements of implanted 210 Po on glass panes surfaces characterize room radon concentration or habitant characterization.Various methods for retrospective radon measurement are described in the literature. The surface trap method is based on the 210 Po implanted on glass or other vitreous objects, measured using solid-state nuclear track detectors (SSNTD). The volume trap method is based on measurements of 210 Po in spongy, porous materials ( 210 Po volume traps). Other approach is in-vivo measurements of 210 Pb in the human skeleton. The present study uses the surface trap retrospective technique for the first time in Israel, coupled with an approach to estimate the 210 Po concentration in glasses exposed to 222 Rn using alpha spectrometry

Development of an electronic monitor for the determination of individual radon and thoron exposure

International Nuclear Information System (INIS)

Irlinger, Josef

2015-01-01

The carcinogenic effect of the radio isotope 222 Rn of the noble gas radon and its progeny, as well as its residential distribution, are well studied. In contrast, the knowledge about the effects and average dwelling concentration levels of its radio isotope 220 Rn (thoron) is still limited. Generally, this isotope has been assumed to be a negligible contributor to the effective annual dose. However, only recently it has been pointed out in several international studies, that the dose due to thoron exceeds the one from 222 Rn under certain conditions. Additionally, radon monitors may show a considerable sensitivity towards thoron which was also not accounted for in general. Therefore a reliable, inexpensive exposimeter, which allows to distinguish between decays of either radon and thoron, is required to conduct further studies. The scope of this thesis was to develop an electronic radon/thoron exposimeter which features small size, low weight and minimal power consumption. The design is based on the diffusion chamber principle and employs state-of-the-art alpha particle spectroscopy to measure activity concentrations. The device was optimized via inlet layout and filter selection for high thoron diffusion. Calibration measurements showed a similar sensitivity of the monitor towards radon and thoron, with a calibration factor of cf 222 Rn = 16.2 ± 0.9 Bq m -3 /cph and cf 220 Rn = 14.4 ± 0.8 Bq m -3 /cph, respectively. Thus, the radon sensitivity of the device was enhanced by a factor two compared to a previous prototype. The evaluation method developed in this work, in accordance with ISO 11665 standards, was validated by intercomparison measurements. The detection limits for radon and thoron were determined to be C 2 22 Rn = 44.0 Bq m -3 and C 2 20 Rn = 40.0 Bq m -3 , respectively, in case of a low radon environment, a one-hour measurement interval, and a background count rate of zero. In contrast, in mixed radon/thoron concentrations where the 212 Po peak must

IL-1RN VNTR polymorphism as a susceptibility marker for nasopharyngeal carcinoma in Portugal.

Science.gov (United States)

Sousa, Hugo; Breda, Eduardo; Santos, Alexandra M; Catarino, Raquel; Pinto, Daniela; Canedo, Paulo; Machado, José Carlos; Medeiros, Rui

2013-08-01

Nasopharyngeal carcinoma (NPC) is a rare malignancy in Western countries that is widely associated with the infection by Epstein-Barr virus (EBV). Several studies have showed that a common allele (allele 2) of the 86-bp variable number of tandem repeats (VNTR) polymorphism within intron 2 of the interleukin 1 receptor antagonist (IL-1RN) gene is associated with several disorders, including viral-associated cancers. We have developed a hospital-based case-control study to characterise the role of the IL-1RN 86-bp VNTR polymorphism in the development of NPC with 112 patients with the disease and 433 healthy individuals from the northern region of Portugal. IL-1RN genotypes were combined according to the number of repeats: allele 2 (A2), the short allele that corresponds to two repeats, and L, the long allele that corresponds to three or more repeats. Our study revealed that 31.2% of NPC patients were IL-1RN A2*A2, compared with 9.7% observed in the control group. The statistical analysis revealed that IL-1RN*A2 homozygosity for the A2 allele was associated with a fourfold increased risk for NPC development (pVNTR in NPC development in Portugal. Our study indicates IL-1RN*A2 homozygosity as a significant risk marker in our population and that it should be further investigated for the potential role in the definition of a susceptibility profile for NPC onset. Copyright © 2013 Elsevier Ltd. All rights reserved.

A sub-nationwide survey of outdoor and indoor 222Rn concentrations in China by passive method

International Nuclear Information System (INIS)

Jin Yihe; Ikebe, Y.; Iida, T.

1996-01-01

From Nov. 1988 to Mar. 1993, cooperated by China and Japan, a survey of outdoor and indoor 222 Rn concentrations in 10 cities which were highly populated in China was carried out by means of passive method. the annual mean of outdoor 222 Rn concentration in 10 cities was 8.8 Bq·m -3 . The highest of 13.5 Bq·m -3 was in Wuhan, the lowest of 3.3 Bq·m -3 was in Chongming Island of Shanghai; and there were no significant differences among the different years in the same areas. During the northwest wind seasons, about 50% of outdoor 222 Rn concentration in Taiwan was contributed by the airflow from the mainland. Typical apartment houses and offices built of brick and concrete were also surveyed for indoor 222 Rn concentration. The annual mean of indoor 222 Rn concentration in the 10 cities was 19.5 Bq·m - 3. The highest of 33.9 Bq·m -3 was observed in Guiyang, the lowest of 9.0 Bq·m -3 was observed in Chongming Island of Shanghai. The outdoor and indoor 222 Rn concentrations showed a clear seasonal pattern with the minimum in summer and the maximum in winter. And they also showed a clear geographic distribution tendency; they were higher in inland than in seashores, and higher in the south than in the north. The ratios of indoor to outdoor 222 Rn concentrations were from 1.1 to 4.6. The annual effective dose equivalents resulting from outdoor and indoor 222 Rn concentrations amounted to about 0.64 mSv·a -1 . The highest was in Guiyang, and the lowest was in Nantong, being 1.12 and 0.39 mSv·a -1 , respectively

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.

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

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

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

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...

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)...

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

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...

An application of 222Rn alpha particle's tracks to uranium exploration

International Nuclear Information System (INIS)

Aguilar H, F.

1981-01-01

The uranium exploration method is based on the register of 222 Rn alpha particles; 222 Rn gas is generated in the chain 238 U desintegration. The detection of alpha particles was performed with cellulose nitrate films (NTC), located in a grid at the region in study. The alpha particles produce latent tracks in the NTC films; these tracks may be enlarged by chemical etching and are observed with an ordinary optic microscope, ninety seven NTC films were used, these were distributed in an area of approximately seventeen square kilometers, located in the municipalities of Granados and Huasabas in Sonora Mexico, the detectors remain in the ground for a thirty days mean period. The results obtained show an area with high 222 Rn concentration, this can be related with an underground uranium ore deposit. The more important conclusion is that the results obtained in this work can be used as preliminary results for other prospection methods in this particular area. (author)

Biodecolorization of Reactive Yellow-2 by Serratia sp. RN34 Isolated from Textile Wastewater.

Science.gov (United States)

Najme, Rabia; Hussain, Sabir; Maqbool, Zahid; Imran, Muhammad; Mahmood, Faisal; Manzoor, Hamid; Yasmeen, Tahira; Shehzad, Tanvir

2015-12-01

Remediation of colored textile wastewaters is a matter of interest. In this study, 49 bacteria were isolated from the textile wastewater and tested for their ability to decolorize reactive yellow-2 (RY2) dye. The most efficient isolate, RN34, was identified through amplification, sequencing, and phylogenetic analysis of its 16S rDNA and was designated as Serratia sp. RN34. This bacterium was also found capable of decolorizing other related reactive azo-dyes, including reactive black-5, reactive red-120, and reactive orange-16 but at varying rates. The optimum pH for decolorization of RY2 by the strain RN34 was 7.5 using yeast extract as cosubstrate under static incubation at 30 °C. The strain RN34 also showed potential to decolorize RY2 in the presence of considerable amounts of hexavalent chromium and sodium chloride. A phytotoxicity study demonstrated relatively reduced toxicity of RY2 decolorized products on Vigna radiata plant as compared to the uninoculated RY2 solution.

Calibration of a degassing-emanation line for 222Rn determination in seawater samples

International Nuclear Information System (INIS)

Farias, Luciana Aparecida

2002-01-01

The purpose of this study is to calibrate a degassing-emanation line and to determine 222 Rn and 226 Ra activity concentrations in seawater samples. This methodology, also called Lucas method, consists in the extraction of radon (originally dissolved in seawater), collection of the gas in a liquid nitrogen cold trap and transfer from the trap to an alpha scintillation cell. Total extraction efficiencies of the 4 degassing-emanation systems were determined by measuring 226 Ra reference solutions. The efficiencies obtained for these 4 systems varied from 21 % to 62%. This work also presents preliminary results of a study carried out in a series of small embayements of Ubatuba, Sao Paulo State-Brazil: Flamengo Bay, Fortaleza Bay, Mar Virado Bay and Ubatuba Bay. Concentration of Rn in excess varied from 0,011 to 0,317 Bq/L for Flamengo Bay, from 0,009 to 0,130 Bq/L for Fortaleza Bay, from 0,018 to 0,050 Bq/L for Mar Virado Bay and from 0,004 to 0,120 Bq/L for Ubatuba Bay. The results obtained for the concentration of 222 Rn in excess in a transect at Flamengo Bay varied from 0,002 to 0,036 Bq/L. Higher concentrations of 222 Rn in excess were obtained in Flamengo Bay, Fortaleza Bay and Ubatuba bay. It was also observed that the concentration of 222 Rn in excess increases with depth, as expected. (author)

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.

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)

Build up of radon, /sup 218/Po and /sup 214/Po in a Karlsruhe diffusion chamber as a function of time

International Nuclear Information System (INIS)

Fazal-ur-Rehman; Jamil, K.; Ali, S.; Khan, H.A.

1996-01-01

Passive radon /sup 222/Rn dosimeters employing particle detectors are widely used in concentration (p Ci/l) measurement in houses, mines and other areas of activity. These dosimeters yield track density which is needed to be converted into physically meaningful parameter of radon concentration in either p Ci/l or Bq m/sup -3/. Therefore, it is required to know the separate contributions of /sup 222/Rn and its progeny. In the present study we have measured the concentration of /sup 222/Rn and its daughters (/sup 218/Po and /sup 214/Po) separately in the Karlsruhe diffusion chamber radon dosimeter, with and without a filter, as a function of time by an active method using a surface barrier detector. The build up behavior of radon and its two daughters (/sup 218/Po and /sup 214/Po) as a function of time was studied by plotting the area under each peak versus collection time. The differential curves and the relative concentration of radon daughters as a function of time were also studied. The concentration of radon and its daughters shows a somewhat linear build up as a function of time for the presently studied time periods. The results of this experiment are expected to be useful in converting the integrated alpha track density as measured by a particle track detector, (used in passive radon dosimetry) to radon concentration levels and for determination of equilibrium factor. (author)

Health effects assessment in population exposed to 222Rn in drinking water

International Nuclear Information System (INIS)

Burkhardt, R.; Mocsy, I.; Muntean, N.

1996-01-01

The carcinogenetic effect produce by ionizing radiation upon human health, mainly by drinking water consumption with an elevated 222 Rn content is well documented. The objective of the paper was to demonstrated the possible relationship between the incidence of pulmonary and gastric cancer and 222 Rn presence in water and indoor air. The 222 Rn content was assessed by the standard method in drinking water sampled in two sources in Transylvania area from located in Tirgu Mures and Miercurea Ciuc towns. The 222 Rn concentration in indoor air was indirectly determined. On the basis of the registered values the pulmonary and gastric internal dose received by the residents of the towns was calculated. In parallel was performed a retrospective epidemiological study (1980-1992) regarding the incidence of gastric and pulmonary cancer in two towns in terms of morbidity, mortality and lethality indices. By comparing the estimated carcinogenic risk for this type of cancer with the specific mortality rate registered in our study, we estimate the contribution of 222 R to the cancer mortality percentage in the two towns, as follows: 0.47% for Tirgu Mures and 0.01% for Miercurea Ciuc town for pulmonary cancer and 0.23% and 0.015% for gastric cancer. (author)

Absolute exposure determination of cobalt-60 gamma radiation

International Nuclear Information System (INIS)

Ahmad, S.S.; Ali, A.; Orfi, S.D.

1986-02-01

The report describes the procedure for the determination of absolute exposure for Cobalt-60 gamma radiation. A graphite cavity chamber, nominal volume of 1 cm 3 , manufactured by Austrian Research Centre Seibersdorf has been used. The exposure rate at reference distance determined with the graphite chamber was compared with mean exposure rate measured with NPL-Therapy level X-ray exposure meter normalized to same date. An agreement of 0.39% was found between the two measuring systems, which seems to be very encouraging and quite satisfactory. (authors)

Calibration of a degassing-emanation line for 222Rn determination in seawater samples; Calibracao de uma linha de emanacao para determinacao de {sup 222}Rn em amostras de agua do mar

Energy Technology Data Exchange (ETDEWEB)

Farias, Luciana Aparecida

2002-07-01

The purpose of this study is to calibrate a degassing-emanation line and to determine {sup 222}Rn and {sup 226}Ra activity concentrations in seawater samples. This methodology, also called Lucas method, consists in the extraction of radon (originally dissolved in seawater), collection of the gas in a liquid nitrogen cold trap and transfer from the trap to an alpha scintillation cell. Total extraction efficiencies of the 4 degassing-emanation systems were determined by measuring {sup 226}Ra reference solutions. The efficiencies obtained for these 4 systems varied from 21 % to 62%. This work also presents preliminary results of a study carried out in a series of small embayements of Ubatuba, Sao Paulo State-Brazil: Flamengo Bay, Fortaleza Bay, Mar Virado Bay and Ubatuba Bay. Concentration of Rn in excess varied from 0,011 to 0,317 Bq/L for Flamengo Bay, from 0,009 to 0,130 Bq/L for Fortaleza Bay, from 0,018 to 0,050 Bq/L for Mar Virado Bay and from 0,004 to 0,120 Bq/L for Ubatuba Bay. The results obtained for the concentration of {sup 222}Rn in excess in a transect at Flamengo Bay varied from 0,002 to 0,036 Bq/L. Higher concentrations of {sup 222}Rn in excess were obtained in Flamengo Bay, Fortaleza Bay and Ubatuba bay. It was also observed that the concentration of {sup 222}Rn in excess increases with depth, as expected. (author)

Tutoring for Success: Empowering Graduate Nurses After Failure on the NCLEX-RN.

Science.gov (United States)

Lutter, Stacy L; Thompson, Cheryl W; Condon, Marian C

2017-12-01

Failure on the National Council Licensure Examination for Registered Nurses (NCLEX-RN) is a devastating experience. Most research related to NCLEX-RN is focused on predicting and preventing failure. Despite these efforts, more than 20,000 nursing school graduates experience failure on the NCLEX-RN each year, and there is a paucity of literature regarding remediation after failure. The aim of this article is to describe an individualized tutoring approach centered on establishing a trusting relationship and incorporating two core strategies for remediation: the nugget method, and a six-step strategy for question analysis. This individualized tutoring method has been used by three nursing faculty with a 95% success rate on an NCLEX retake attempt. Further research is needed to identify the elements of this tutoring method that influence success. [J Nurs Educ. 2017;56(12):758-761.]. Copyright 2017, SLACK Incorporated.

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.)

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

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

The Beckman-Quarles theorem for continuous mappings from R^n to C^n

OpenAIRE

Tyszka, Apoloniusz

2002-01-01

Let \\phi((x_1,...,x_n),(y_1,...,y_n))=(x_1-y_1)^2+...+(x_n-y_n)^2. We say that f:R^n -> C^n preserves distance d>=0 if for each x,y \\in R^n \\phi(x,y)=d^2 implies \\phi(f(x),f(y))=d^2. We prove that if x,y \\in R^n (n>=3) and |x-y|=(\\sqrt{2+2/n})^k \\cdot (2/n)^l (k,l are non-negative integers) then there exists a finite set {x,y} \\subseteq S(x,y) \\subseteq R^n such that each unit-distance preserving mapping from S(x,y) to C^n preserves the distance between x and y. It implies that each continuou...

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.

Development of a preclinical 211Rn/211At generator system for targeted alpha therapy research with 211At.

Science.gov (United States)

Crawford, Jason R; Yang, Hua; Kunz, Peter; Wilbur, D Scott; Schaffer, Paul; Ruth, Thomas J

2017-05-01

The availability of 211 At for targeted alpha therapy research can be increased by the 211 Rn/ 211 At generator system, whereby 211 At is produced by 211 Rn electron capture decay. This study demonstrated the feasibility of using generator-produced 211 At to label monoclonal antibody (BC8, anti-human CD45) for preclinical use, following isolation from the 207 Po contamination also produced by these generators (by 211 Rn α-decay). 211 Rn was produced by 211 Fr electron capture decay following mass separated ion beam implantation and chemically isolated in liquid alkane hydrocarbon (dodecane). 211 At produced by the resulting 211 Rn source was extracted in strong base (2N NaOH) and purified by granular Te columns. BC8-B10 (antibody conjugated with closo-decaborate(2-)) was labeled with generator-produced 211 At and purified by PD-10 columns. Aqueous solutions extracted from the generator were found to contain 211 At and 207 Po, isolated from 211 Rn. High radionuclidic purity was obtained for 211 At eluted from Te columns, from which BC8-B10 monoclonal antibody was successfully labeled. If not removed, 207 Po was found to significantly contaminate the final 211 At-BC8-B10 product. High yield efficiencies (decay-corrected, n=3) were achieved for 211 At extraction from the generator (86%±7%), Te column purification (70%±10%), and antibody labeling (76%±2%). The experimental 211 Rn/ 211 At generator was shown to be well-suited for preclinical 211 At-based research. We believe that these experiments have furthered the knowledge-base for expanding accessibility to 211 At using the 211 Rn/ 211 At generator system. As established by this work, the 211 Rn/ 211 At generator has the capability of facilitating preclinical evaluations of 211 At-based therapies. Copyright © 2017 Elsevier Inc. All rights reserved.

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.)

Kan adoption hjælpe de glemte børn?

DEFF Research Database (Denmark)

Christoffersen, Mogens

2008-01-01

Er adoption bedre end opvækst på en moderne døgninstitution eller hos en plejefamilie? I et velfærdssamfund som det danske med lang tradition for fokus på, hvordan det går de anbragte børn, er dette et centralt spørgsmål.......Er adoption bedre end opvækst på en moderne døgninstitution eller hos en plejefamilie? I et velfærdssamfund som det danske med lang tradition for fokus på, hvordan det går de anbragte børn, er dette et centralt spørgsmål....

Updated estimates of HAL n and RN- effects on pork quality: fresh and processed loin and ham.

Science.gov (United States)

Cherel, P; Glénisson, J; Figwer, P; Pires, J; Damon, M; Franck, M; Le Roy, P

2010-12-01

A 1000-pig F2 intercross QTL detection experimental population was generated using two commercial sire lines. Independent carriers of HAL n and RN- mutations (10% and 14%, respectively) were included in this population as control genotypes. The effects of HAL n and RN- heterozygous genotypes on fresh and transformed loins and hams were estimated using a mixed model methodology. The results document the unfavorable effects of both mutations on meat quality. Smaller effects of HAL Nn genotype compared to HAL nn or RN-rn+ genotypes were estimated. Interestingly, effects of HAL Nn genotype on meat pH and loin color could be insignificant at 24-h postmortem, but translate into higher water losses on storage and cooking, and result in tougher cooked loin. Using the same methodology, significant effects of the PRKAG3 (RN) I199 allele on ultimate pH values but not on glycolytic potential were observed. Copyright © 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.

Measurements of 222Rn and its daughters and estimation of internal doses to workers in underground buildings

International Nuclear Information System (INIS)

Cao Jianping; Lu Zhizhao; Li Yuanshan

1993-03-01

The results of concentration measuring of 222 Ru and its daughters and estimation of internal doses to workers in the underground buildings at Nanjing city are presented. The double filtering membrane method and Thomas method were used in the monitoring of 222 Rn and its daughters, and the dose conversion factor was taken from the latest UNSCEAR report. Concentration distributions of 222 Rn and its daughters were approximately log-normal. The geometric means for 222 Rn was 40.5 Bq · m -3 and for its daughters was 1.4 x 10 -7 J · m -3 . The equilibrium factor was 0.63. The radioactive equilibrium ratio between short-lived 222 Rn daughters was 1:0.57:0.49. The estimation value of annual effective dose equivalent from 222 Rn daughters to workers working at underground sites was 1.3 mSv, which was 86% higher than that of those working on ground sites

Radiation exposure of the public as a result of the present operations of Ranger Uranium Mines Pty Ltd

Energy Technology Data Exchange (ETDEWEB)

Koperski, J

1986-04-01

Ranger Uranium Mines monitors ambient levels of ionising radiation in accordance with the Code of Practice on Radiation Protection in the Mining and Milling of Radioactive Ores 1980. The radionuclides of interest are: U-238, Th-230, Ra-226, Pb-210, Po-210 and Rn-222 daughters (RnD). The aerial pathway appears to be the critical pathway for transfer of radioactive contaminants to the local population. The average annual effective dose equivalent rate to a member of the critical group from inhalation of long-lived radioactive dust is 0.22 +- 0.10 mSv/y, about 22 times below the limit of 5 mSv/y. No experimental evidence was found for any overall increase of exposure of the public due to consumption of bush food items collected in the vicinity of the Ranger site. The average exposure of the critical group member to RnD is likely to be 2.1 +- 3.1 mWLM/y, or 200 times below the annual limit of 0.4 WLM.

Gas exchange in the Pee Dee River based on 222Rn evasion

International Nuclear Information System (INIS)

Moore, W.S.; Elsinger, R.J.

1983-01-01

Excess 222 Rn concentrations decrease downstream in the fresh water section of the Pee Dee River. Ground water is the primary source of the excess 222 Rn to the River. Using the radon concentration gradients determined during four sampling periods, gas exchange rates based on the stagnant film model are calculated. Stagnant film thicknesses range from 19 μm to 48 μm and mass transfer coefficients range from 2.1 m/d to 4.1 m/d

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.

The influence of the nature of soil and plant and pollution on the 238U, 232Th, 222Rn and 220Rn concentrations in various natural honey samples using nuclear track detectors: impact on the adult consumers

International Nuclear Information System (INIS)

Misdaq, M.A.; Mortassim, A.

2009-01-01

238 U and 232 Th concentrations as well as 222 Rn and 220 Rn α-activities per unit volume were measured in various natural honey samples collected from different regions in Morocco using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs). These radionuclides were also measured in soils, plant flowers and nectar solutions corresponding to the honey samples studied. In addition, these radionuclides were measured in different imported honey samples. The measured 238 U, 232 Th, 222 Rn and 220 Rn concentrations ranged from (1.5 ± 0.1) mBq kg -1 to (10.6 ± 0.6) mBq kg -1 , (1.1 ± 0.1) mBq kg -1 to (4.2 ± 0.2) mBq kg -1 , (1.5 ± 0.1) Bq kg -1 to (10.6 ± 0.6) Bq kg -1 and (1.1 ± 0.1) Bq kg -1 to (4.2 ± 0.2) Bq kg -1 for the honey samples studied, respectively. Annual 238 U, 232 Th and 222 Rn intakes by Moroccan adults from the consumption of honey were assessed. The influence of the nature of soil and plant on the 238 U and 232 Th contents of the studied honey samples was investigated. These measurements were completed by an investigation of the 238 U and 232 Th transfer between soils and plant flowers and that between plant flowers and honey, and also by the investigation of the influence of pollution due to different material dusts on 238 U, 232 Th and 222 Rn in the honey samples studied. Committed equivalent doses due to the annual intake of 238 U, 232 Th and 222 Rn were evaluated in the organs of adult members of the Moroccan rural population from the ingestion of the honey samples. The maximum total committed effective dose due to 238 U, 232 Th and 222 Rn from the ingestion of natural honey by the Moroccan rural population was found to be equal to 0.64 μSνy -1 . (author)

222Rn concentration in the outdoor atmosphere and its relation to the atmospheric stability

International Nuclear Information System (INIS)

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

1998-01-01

The radon in the outdoor atmosphere has been monitored continuously since 1991. On the basis of the measured data mainly the average daily and the average annual courses of the 222 Rn concentrations have been studied. The annual courses of 222 Rn concentration are similar for all years. They present the annual variations. The average course of the 222 Rn concentration calculated on the basis of all continual measurements in the years 1991-1997 reaches the maximum value in October and the minimum value in April. The average daily courses of the 222 Rn concentration for the individual months of the year. The average daily courses have a form of waves with a maximum in the morning hours and with a minimum in the afternoon. The maximal amplitudes of daily waves have been reached in the summer months, from June till August. The amplitudes of daily waves are very small at the end of an autumn and during the winter months. The analysis of the daily waves and annual courses of 222 Rn showed that the amplitudes of the daily waves are in proportion to the global solar radiation irradiating the Earth's surface. The day duration influence on the phase of the daily wave and the wind velocity influence mainly on the level of the radon concentration. For the study of the relation of the radon concentration in the outdoor atmosphere to the stability the data of the atmosphere were obtained and they were correlated with the radon concentration. The results indicate that the 222 Rn concentrations int he outdoor atmosphere could be used for determination of the vertical atmospheric stability and these ones could reflect the atmospheric stability more completely than the different classifications based on the knowledge pertinent to the meteorological parameters. (authors)

A SIMPLE Bubble Chamber for Dark Matter Searches: Testing and Development

Energy Technology Data Exchange (ETDEWEB)

Ramos, A.R.; Fernandes, A.C.; Marques, J.G.; Kling, A. [C2TN, Instituto Superior Tecnico, Universidade de Lisboa, E.N. 10 - km 139.7, 2695-066 Bobadela, LRS (Portugal); Felizardo, M.; Girard, T.A. [Centro de Fisica Nuclear, Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003, Lisbon (Portugal); Lazaro, I. [Laboratoire Souterrain a Bas Bruit, UMS 3538 UNS/UAPV/CNRS, 84400 Rustrel-Pays d' Apt (France); Puibasset, J. [Centre de Recherche sur la Matiere Divisee CNRS et Universite d' Orleans, 45071 Orleans, 02 (France)

2015-07-01

SIMPLE (Superheated Instrument for Massive Particle Experiments) is one of only three experiments worldwide in search of evidence of astroparticle dark matter (WIMPs) using halocarbon-loaded superheated liquid (SHL) detectors. The 2012 Phase II SIMPLE measurements yielded the most restrictive exclusion contour in the spin-dependent (SD) sector of WIMP-proton interactions from a direct search experiment at the time, overlapping for the first time results previously obtained only indirectly [1]. In order to remain competitive with other experiments in the field, the next phase measurement requires larger exposure over shorter observation times with significantly improved neutron shielding. To increase exposure, SIMPLE plans, as a first step, to replace its superheated droplet detectors (SDDs), each containing an active mass of about 15 g of halocarbon, with bubble chambers capable of holding up to 20 kg of active halocarbon mass. We report on the development of the first 1 kg halocarbon SIMPLE bubble chamber prototype, including chamber recompression system design and testing and initial acoustic detection of bubble formation. (authors)

New indoor environment chambers and field experiment offices for research on human comfort, health and productivity

DEFF Research Database (Denmark)

Toftum, Jørn; Langkilde, Gunnar; Fanger, Povl Ole

2004-01-01

The article describes three new indoor environment chambers, a new laboratory for the study of air movement in spaces and five offices for controlled environment exposures of human subjects in field experiments at the International Centre for Indoor Environment and Energy, Technical University of...... of Denmark. Together with three older chambers, the Centre now has at its disposal 12 spaces for studying indoor environments and their impact on human comfort, health and productivity.......The article describes three new indoor environment chambers, a new laboratory for the study of air movement in spaces and five offices for controlled environment exposures of human subjects in field experiments at the International Centre for Indoor Environment and Energy, Technical University...

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.).

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.)

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.

Direct determination of 222Rn gas using the electret to remove daughters at formation

International Nuclear Information System (INIS)

Harley, N.H.

1981-01-01

Five compact, portable, continuous 222 Rn monitors have been constructed inhouse. Printed data can be obtained from intervals ranging from 10 minutes to 990 minutes. One hour count interval provides a lower limit of detection of 0.03 pCi 222 Rn/l -1 which is sufficient for measurement of any environmental level encountered. Calibration of the units was accomplished in the EML radon calibration room and the typical calibration factor is 165 counts per hour per pCi 222 Rn/l. The units are now being field tested. Two indoor/outdoor pairs are located in a single family dwelling and in a high rise apartment. One unit is being used for special studies

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)

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.

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)

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

AGE-DEPENDENT INHALATION DOSE DUE TO EXPOSURE OF SHORT LIVED PROGENY OF RADON AND THORON FOR DIFFERENT AGE GROUPS IN JAMMU & KASHMIR, HIMALAYAS.

Science.gov (United States)

Sharma, Sumit; Kumar, Ajay; Mehra, Rohit

2018-05-16

Dosimetric approach is used in this study for the assessment of doses due to inhalation of short lived radon/thoron progeny to the inhabitants of Udhampur district of Jammu & Kashmir. This paper also presents the activity concentrations and unattached fraction of radon and thoron progeny. The observed annual concentration of attached and unattached 222Rn and 220Rn progeny has been found to vary from 8 to 32 and 0.09 to 14 Bq/m3, 0.75 to 3.16 and 0.01 to 1.13 Bq/m3, respectively. The inhalation doses from radon progeny to different body organs of different age groups have been calculated by using the age dependent biokinetic model. The attachment rate of 222Rn and indoor aerosol concentration of 222Rn and 220Rn have been estimated and their relation between them has also been studied. The dose conversion factor for mouth and nasal breathing to different exposure conditions has been obtained from Porstendorfer model.

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...

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...

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

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

Evolution of the concept of reduction the exposure levels to natural radiation and the new international standards in protection of radon

International Nuclear Information System (INIS)

Pavlovic, R.; Pavlovic, S.

1995-01-01

The new scientific information in last decade have caused significant changes in radiation protection standards. The subject of reduction the exposure to natural radiation is now regulated in more details. Some new aspects in protection against Rn exposure at home and work are discussed. (author)

Method for sequentially processing a multi-level interconnect circuit in a vacuum chamber

Science.gov (United States)

Routh, D. E.; Sharma, G. C. (Inventor)

1984-01-01

An apparatus is disclosed which includes a vacuum system having a vacuum chamber in which wafers are processed on rotating turntables. The vacuum chamber is provided with an RF sputtering system and a dc magnetron sputtering system. A gas inlet introduces various gases to the vacuum chamber and creates various gas plasma during the sputtering steps. The rotating turntables insure that the respective wafers are present under the sputtering guns for an average amount of time such that consistency in sputtering and deposition is achieved. By continuous and sequential processing of the wafers in a common vacuum chamber without removal, the adverse affects of exposure to atmospheric conditions are eliminated providing higher quality circuit contacts and functional device.

Pla(y)cefully – når børn finder sted gennemt transformationer af institutionelle konstruktioner

DEFF Research Database (Denmark)

Nørgård, Rikke Toft; Toft, Herdis

2014-01-01

, designere, kunstnere, pædagoger og forældre understøtte, at børn finder sted som mennesker i verden? Et svar kunne være, at vi, snarere end at indplacere børn i ’satte’ institutionelle kontekster, lader børn ’sætte’ deres eget sted, fx ved at lade dem ’pla(y)cefully’ transformere, hvad et gulv i en...... børnehave kan være, lade dem opdage, opfinde, opbygge og omskabe det. Lade børn eksperimentere og konstruere sig frem til egne pla(y)ces. Gennem en transdisciplinær tilgang kombinerer dette paper indsigter og resultater fra to særskilte forskningsprojekter omkring børn i børnehaver. Det ene projekt har...... gennem leg med artefakter, redskaber og teknologier i krydsfeltet mellem interaktionsdesign, human-centered design, digitale teknologier og konstruktionisme. Gennem den transdisciplinære tilgang til pla(y)ces og pla(y)cefullness og på bagrund af centrale emergerende kategorier i de to feltarbejder...

Sünteetiline lähenemine on edu pant / Tamara Luuk, Olga Pärn, Priit Pärn ; intervjueerinud Reet Varblane

Index Scriptorium Estoniae

Luuk, Tamara, 1952-

2011-01-01

Brügges kuni jaanuari lõpuni 2011 eksponeeritud belgia kunstniku Luc Tuymansi kureeritud näitusest "Madalaima tasandi reaalsus. Visioon Kesk-Euroopast" ("The Reality of the Lowest Rank. A Vision of Central Europe"). Osalema oli kutsutud 43 kunstnikku üle maailma. Priit Pärn Eestist esines söejoonistuste ja filmilõikudega näitusel ning eraldi filmiprogrammiga

Development of an electronic monitor for the determination of individual radon and thoron exposure

Energy Technology Data Exchange (ETDEWEB)

Irlinger, Josef

2015-06-11

The carcinogenic effect of the radio isotope {sup 222}Rn of the noble gas radon and its progeny, as well as its residential distribution, are well studied. In contrast, the knowledge about the effects and average dwelling concentration levels of its radio isotope {sup 220}Rn (thoron) is still limited. Generally, this isotope has been assumed to be a negligible contributor to the effective annual dose. However, only recently it has been pointed out in several international studies, that the dose due to thoron exceeds the one from {sup 222}Rn under certain conditions. Additionally, radon monitors may show a considerable sensitivity towards thoron which was also not accounted for in general. Therefore a reliable, inexpensive exposimeter, which allows to distinguish between decays of either radon and thoron, is required to conduct further studies. The scope of this thesis was to develop an electronic radon/thoron exposimeter which features small size, low weight and minimal power consumption. The design is based on the diffusion chamber principle and employs state-of-the-art alpha particle spectroscopy to measure activity concentrations. The device was optimized via inlet layout and filter selection for high thoron diffusion. Calibration measurements showed a similar sensitivity of the monitor towards radon and thoron, with a calibration factor of cf{sup {sub 2}{sub 2}{sub 2Rn}} = 16.2 ± 0.9 Bq m{sup -3}/cph and cf{sup {sub 2}{sub 2}{sub 0Rn}} = 14.4 ± 0.8 Bq m{sup -3}/cph, respectively. Thus, the radon sensitivity of the device was enhanced by a factor two compared to a previous prototype. The evaluation method developed in this work, in accordance with ISO 11665 standards, was validated by intercomparison measurements. The detection limits for radon and thoron were determined to be C{sup {sub 2}{sub 2}{sub 2Rn}} = 44.0 Bq m{sup -3} and C{sup {sub 2}{sub 2}{sub 0Rn}} = 40.0 Bq m{sup -3}, respectively, in case of a low radon environment, a one-hour measurement

The Multivariate Müntz-Szasz Problem in Weighted Banach Space on Rn

Directory of Open Access Journals (Sweden)

Xiangdong Yang

2014-01-01

Full Text Available The purpose of this paper is to give an extension of Müntz-Szasz theorems to multivariable weighted Banach space. Denote by {λk=(λk1,λk2,...,λkn}k=1∞ a sequence of real numbers in R+n. The completeness of monomials {tλk} in Cα is investigated, where Cα is the weighted Banach spaces which consist of complex continuous functions f defined on Rn with f(t exp(-α(t vanishing at infinity in the uniform norm.

Pärnävaaran 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...

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)

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)

Diskussioner om børneperspektiv og inddragelse af børn - er barnet på vej ud med badevandet?

DEFF Research Database (Denmark)

Warming, H.

2007-01-01

Artiklen omhandler den nye sociologiske barndomsforsknings fordring på børneperspektiv og inddragelse af børn. Indledningsvis gøres der rede for, hvordan der i den nye barndomsforskning er blevet argumenteret både erkendelsesteoretisk og etisk for børneperspektiv og inddragelse af børn i forsknin......Artiklen omhandler den nye sociologiske barndomsforsknings fordring på børneperspektiv og inddragelse af børn. Indledningsvis gøres der rede for, hvordan der i den nye barndomsforskning er blevet argumenteret både erkendelsesteoretisk og etisk for børneperspektiv og inddragelse af børn i...

The measurement of 222Rn in drinking water by low-level liquid scintillation counting

International Nuclear Information System (INIS)

Barnett, J.M.; McKlveen, J.W.

1992-01-01

Radon-222 (Rn) has universally been found in well water. Non-stagnant ground water is collected at the well head while the well is pumping. The water is adjusted to a slow, non-aerated, steady flow through a clear tube, and a 500 ml glass bottle is filled. The sample is tightly capped after a high meniscus has developed. In the laboratory, standard 22 ml glass vials are filled with 10 ml of a toluene based mineral oil LS cocktail. Then, two 5 ml sample aliquots are pipetted into the vial. Vials are capped tightly, shaken vigorously, and placed in the liquid scintillation (LS) counter. Secular equilibrium is established in approximately 4 hours, after which samples are counted for 100 minutes each. The counting efficiency for Rn and progeny ranges between 315 to 345 percent depending on the chosen spectral window. The average background is about 6 cpm. A total of 28 wells were tested for Rn in the Carefree-Cave Creek, Arizone, USA area. The area's geometric average Rn concentration was found to be 46.5 Bq*1 -1 . The associated estimated lung dose is 0.51 mSv*y -1 . (author) 8 refs.; 1 fig.; 1 tab

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

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.)

222Rn and 14CO2 concentrations in the surface layer of the atmosphere

International Nuclear Information System (INIS)

Holy, K.; Chudy, M.; Sivo, A.; Richtarikova, M.; Boehm, R.; Polaskova, A.; Vojtyla, P.; Bosa, I.; Hola, O.

2002-01-01

Long-term monitoring of the Δ 14 C in the atmospheric near-ground CO 2 has been realized in Bratislava and Zlkovce, situated near the nuclear power plant Jaslovske Bohunice. Until 1993, the monthly mean Δ 14 C values showed a high variability. The annual means of Δ 14 C were about 30 per mille higher at Zlkovce than in highly industrialised Bratislava. An important change in the behaviour of the 14 C data has occurred since 1993. The records from both stations show the similar course, mainly due to the fact that there do not occur deep winter minima in Bratislava. This behaviour corresponds to the lower values of the total fossil fuel CO 2 emissions in the years after 1993 when compared to the previous years. At present, both sets of data show that the 14 C concentration is about 10% above the natural level. Since 1987 also the 222 Rn concentration in the surface layer of the atmosphere has been measured in Bratislava. These measurements provided an extensive set of the 222 Rn data characteristic for the inland environment with high level of atmospheric pollution. The seasonal and daily variations of the 222 Rn concentration were observed. The investigation of the relation between the monthly mean diurnal courses of the 222 Rn concentration and the atmospheric stability proved a high correlation between them. The 222 Rn data were used to interpret the anomalous Δ 14 C values in the surface layer of the atmosphere. (author)

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.

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.)

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)

Determination of 222Rn in water samples from wells and springs in Tokyo by a modified integral counting method

International Nuclear Information System (INIS)

Homma, Y.; Murase, Y.; Handa, K.; Murakami, I.

1997-01-01

222 Rn in 2L-water samples was extracted with 30 mL toluene, and 21 mL of the toluene solution was transferred into a liquid scintillation vial, in which PPO - 2,5-diphenyloxazole was placed in advance. The total activity of 222 Rn in the water sample was calculated based on the Ostwald's coefficient of solubilities of 222 Rn in toluene and water at the temperature of the sample water and the volume of water and toluene. About 40% of 222 Rn dissolved in 2L-water sample can be collected. After allowing to stand for 3.5 h, the equilibrium mixture of 222 Rn and its daughters was measured with an Aloka liquid scintillation spectrometer using a modified integral counting method which extrapolates the integral counting curve not to the zero pulse-height, but to the zero detection threshold, an average energy required to produce a measurable pulse, of the liquid scintillation spectrometer. The general method which agitates water sample (usually about 10 mL) with a liquid scintillation cocktail is practical when the activity of 222 Rn is high. By adding 10 mL of water sample, however, it is possible also to add variable amounts of quencher. In some cases water sample is preserved with nitric acid. The slope of the integral counting rate curve increases as quench level of the sample increases. Therefore, it is clear that the modified integral counting method gives more accurate 222 Rn concentrations for water samples of strong quench than the conventional integral counting method. 222 Rn sample of 0.2 Bq/L can be determined within an overall uncertainty of 3.1%

Udvikling af dialogisk kompetence hos børn med CI

DEFF Research Database (Denmark)

Dammeyer, Jesper Herup; Carstensen, Susanne; Karlshøj, Bente

2011-01-01

Der er relativ god viden om børn med CI’s sproglige udvikling, hvad angår sproglyde og ord. Derimod er der i den internationale forskning kun beskrevet meget lidt om den del af den sproglige udvikling, som ligger ud over sætningsniveauet. Denne artikel beskriver nogle af de resultater, der er...... fremkommet ved et fire år langt følgestudie af tre førskolebørn med CI. Børnenes sproglige udvikling er observeret og analyseret i forhold til dialogiske kompetencer. Resultaterne peger på, at børnene udvikler gode talesproglige kompetencer i løbet af den fireårige periode, men at børnene har brug for støtte...

Measurement of Rn-222 concentrations in building materials used in jordan

Energy Technology Data Exchange (ETDEWEB)

Ismail, A M; Abumyrad, K M; Kullab, M K; Albataina, B A [Physics Dept., Yarmouk University, 219-10 Irbid, (Jordan)

1995-10-01

In this work, the concentrations of the radiative inert gas Rn-222 emanated from the building materials that are commonly in jordan have been studied. For this purpose, samples of ten jordanian building materials of different masses were prepared in plastic cans sealed to passive integrated dosimeters containing CR-39 solid state nuclear track detectors which are very sensitive to alpha-particles. The Rn-222 concentrations in these samples range from 137 Bq/m{sup 3} to 267 Bq/m{sup 3} with an average of 189 Bq/m{sup 3}. These levels were found to be consistent with those measured by other workers in other countries. 4 figs., 2 tabs.

Measurement of Rn-222 concentrations in building materials used in jordan

International Nuclear Information System (INIS)

Ismail, A.M.; Abumyrad, K.M.; Kullab, M.K.; Albataina, B.A.

1995-01-01

In this work, the concentrations of the radiative inert gas Rn-222 emanated from the building materials that are commonly in jordan have been studied. For this purpose, samples of ten jordanian building materials of different masses were prepared in plastic cans sealed to passive integrated dosimeters containing CR-39 solid state nuclear track detectors which are very sensitive to alpha-particles. The Rn-222 concentrations in these samples range from 137 Bq/m 3 to 267 Bq/m 3 with an average of 189 Bq/m 3 . These levels were found to be consistent with those measured by other workers in other countries. 4 figs., 2 tabs

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)

A Matérn model of the spatial covariance structure of point rain rates

KAUST Repository

Sun, Ying; Bowman, Kenneth P.; Genton, Marc G.; Tokay, Ali

2014-01-01

It is challenging to model a precipitation field due to its intermittent and highly scale-dependent nature. Many models of point rain rates or areal rainfall observations have been proposed and studied for different time scales. Among them, the spectral model based on a stochastic dynamical equation for the instantaneous point rain rate field is attractive, since it naturally leads to a consistent space–time model. In this paper, we note that the spatial covariance structure of the spectral model is equivalent to the well-known Matérn covariance model. Using high-quality rain gauge data, we estimate the parameters of the Matérn model for different time scales and demonstrate that the Matérn model is superior to an exponential model, particularly at short time scales.

A Matérn model of the spatial covariance structure of point rain rates

KAUST Repository

Sun, Ying

2014-07-15

It is challenging to model a precipitation field due to its intermittent and highly scale-dependent nature. Many models of point rain rates or areal rainfall observations have been proposed and studied for different time scales. Among them, the spectral model based on a stochastic dynamical equation for the instantaneous point rain rate field is attractive, since it naturally leads to a consistent space–time model. In this paper, we note that the spatial covariance structure of the spectral model is equivalent to the well-known Matérn covariance model. Using high-quality rain gauge data, we estimate the parameters of the Matérn model for different time scales and demonstrate that the Matérn model is superior to an exponential model, particularly at short time scales.

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.

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....

Forord til den danske udgave af bogen rådgivning og terapi med børn

DEFF Research Database (Denmark)

Kragh-Müller, Grethe

2007-01-01

En bog om rådgivning og terapi med børn med en integrativ indfaldsvinkel. Der tages udgangspunkt i forskellige teorier og metoder.......En bog om rådgivning og terapi med børn med en integrativ indfaldsvinkel. Der tages udgangspunkt i forskellige teorier og metoder....

Development and construction of a specific chamber for phototoxicity test

International Nuclear Information System (INIS)

Sufi, Bianca S.; Mathor, Monica B.; Esteves-Pedro, Natalia M.; Kaneko, Telma Mary

2013-01-01

Phototoxicity corresponds to the acute toxic response induced after skin exposure 'in vivo' and 'ex vivo' to certain chemicals and subsequent exposure to irradiation. Phototoxicity 'in vitro' assay is determined by viability of fibroblasts BALB/c 3T3 exposed to chemicals in the presence and absence of light. Substances identified as phototoxic are susceptible to 'in vivo' phototoxicity (OECD 432, 2004). A chamber was developed and constructed according to the guidelines OECD Toxicity Guide - 432 and ®ECVAM DB-ALM: INVITTOX N. 78. The chamber was built in stainless steel frame, with UVA lamps and dark area for negative control. The tests to qualify the chamber were performed with Sodium Lauryl Sulfate, recommended by the guides aforementioned, as negative control; and Bergamot oil (Givaudan-Roche), as positive control. Bergamot, Citrus bergamia, has, as major component, Bergapten responsible for its photosensitive activity. Both samples were diluted in Phosphate Buffered Saline with concentrations between 0.005 and 0.1 mg/mL, which were calculated by the dilution factor 1.47. These tests were performed over fibroblast BALB/c 3T3 culture and submitted to phototoxicity assay with MTS dye, under spectrophotometric reading, which allows determining the Photo Irritation Factor (PIF), what suggests that a substance with a PIF 2 and 5 provides phototoxicity. Sodium Lauryl Sulfate presented a PIF=1, being in accordance with the OECD. Bergamot oil has shown to be likely phototoxic with a PIF=2,475. These results provide that the chamber is qualified to be used to perform phototoxicity tests with assurance and security. (author)

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...

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

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

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

Use of 222Rn-resistant techniques in new home construction

International Nuclear Information System (INIS)

Watson, J.E. Jr.; Cote, R.A.

1999-01-01

The objective of this project was to assess the status of the use of 222 Rn-resistant construction techniques in new home construction in the eight Zone 1 counties of North Carolina. Zone 1 counties have an average predicted indoor 222 Rn screening potential greater than 148 Bq m -3 (4 pCi L -1 ). To facilitate a response from builders, a brief survey form was designed and printed on the back of a self-addressed, postage-paid postcard. This survey form was mailed to 460 home builders in the Zone 1 counties. The response rate was 17%, which can be compared to the 4.9% response rate obtained in a national survey conducted by the National Association of Home Builders Research Center. In their survey, 62% of the responding builders reported that they had built some or many homes in 1996 using construction techniques to reduce the entry of radon into homes, but only 10% of the builders reported using these techniques for many homes. The National Association of Home Builders survey determined that, nationally, 30% of homes built in Zone 1 counties had 222 Rn venting features. There is the potential for bias in the results of their survey (as well as in the results of the National Association of Home Builders survey) since the response rates were low

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)

Mr Bjørn Haugstad, State Secretary, Ministry of Education and Research, Norway

CERN Multimedia

Maximilien Brice

2003-01-01

Photos 01,02: Mr Bjørn Haugstad, State Secretary, Ministry of Education and Research, Norway signing the guest book; standing, Dr Carlo Wyss Photo 03: Luncheon in honour of Mr Bjørn Haugstad, State Secretary, Ministry of Education and Research, Norway, April 2003. Around the table, from left to right: State Secretary Haugstad (standing); Prof. Cecilia Jarlskog, Adviser to the Director-General for Member State Relations; Mr Morten Knutsen, CERN staff - Purchase; Mr Jens Vigen, CERN staff, Library and Norwegian Contact; Prof. Steinar Stapnes, Prof. Univ. of Oslo and Physicist in the ATLAS experiment (in profile), Dr Carlo Wyss, Director for Accelerators (standing), Dr Leif Westgaard, Senior Adviser, Research Council of Norway, CERN Delegate. Photo 04: Luncheon in honour of Mr Bjørn Haugstad, State Secretary, Ministry of Education and Research, Norway, April 2003. Around the table, from left to right: State Secretary Haugstad (standing); Mr Jens Vigen, CERN staff, Library and Norwegian Contact; Prof. Steinar ...

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.

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.

Model equations for Calculating Rn-gas Concentrations in Air of Uranium Exploratory Tunnels, Allouga, West-Central Sinai , Egypt

International Nuclear Information System (INIS)

Abdel-Monem, A.A.; Soliman, S.F.H.; Abd El-Kader, F.H.; El-Naggar, A.M.; Eissa, H.M.; Abd El-Hafez, A.A.

2001-01-01

Gabal Allouga area is located some 40 km due east from Abu Zenima town on the east coast of the Gulf of Suez, West-Central Sinai, Egypt. A network of exploratory tunnels totaling 670m in length and approximately 2x2 m in cross section, were excavated within a paleosol clayey bed. They host (Fe, Mn)-, Cu-, and U-mineralizations. Portions of the tunnels are naturally ventilated and others portions are non-ventilated and show ground water seepage through fractures. Model equations were developed for calculating the Rn-gas concentrations in the air of the tunnels under dry conditions where Rn-gas transport is mainly by air flow through porous media as well as for wet conditions where Rn-gas transport is mainly by ground water flow into the tunnels. Under dry conditions the model calculated Rn-gas concentrations(15.2-60.6 PCi/1) are consistent with measured values by active techniques (3.26-22.85 pCi/1) and by SSNTD techniques (19-69.1 pCi/1) when the Rn-emanation coefficient (alpha= 0.05-0.2), the emanating rock thickness (X=10 cm) and U-concentration averages 30 ppm. Under wet and non-ventilated conditions the model calculated Rn-gas concentrations (159-1248 pCi/1) are consistent with the measured values by active techniques (231-1348 pCi/1) and by SSNTD techniques (144-999pCi/1), when the Rn-emanation coefficient (alpha=0.1-0.25), the ground water flow (F=0.04-0.10 ml/s -1 cm -2 ) and U-concertrations (100-250ppm)

Development Of Protocols For Simultaneous Measurements Of Rn, Tn Using Nuclear Track Detectors And Trial Application In Mining Areas Of Vietnam

International Nuclear Information System (INIS)

Bui Dac Dung; Trinh Van Giap; Le Dinh Cuong; Tran Khanh Minh; Nguyen Huu Quyet; Nguyen Van Khanh; Tran Ngoc Toan

2013-01-01

Radioactive gases Radon (Rn) and Thoron (Tn) contribute of more than 50% of natural radiation dose. However, separate measurements of Rn and Tn have not been paid enough attention. An Intergovernmental Cooperation Project was conducted at the Institute for Nuclear Science and Technology with the help from Hungarian experts. The main tasks of the project were to finalize 02 protocols for simultaneous measurements of Rn and Tn using nuclear track detectors and to test these protocols in investigating the concentrations of Rn and Tn, calculating the natural dose due to Rn and Tn, and evaluating the increased radiation dose and radiation safety due to mining activities. Main results of the project include 02 protocols for simultaneous measurements of Rn and Tn and the test results in the mining areas. Rn and Tn concentrations inside the coal mining tunnels are in the average level of Vietnam and the world. Tn concentration inside the factory for separating Zircon at the Ha Tinh Zircon Processing Plant was found to be very high, up to 2931 Bq/m 3 . Based on annual effective dose calculation, workers inside the factory for separating Zircon at the Ha Tinh Zircon Processing Plant could receive an annual effective dose due to Rn and Tn of 4.890 mSv/year, and the increasing dose of 4.710 mSv/year is for higher than 1 mSv/year recommended by the IAEA. (author)

Decompression sickness rates for chamber personnel: case series from one facility.

Science.gov (United States)

Brandt, Megan S; Morrison, Thomas O; Butler, William P

2009-06-01

During 2004, a case series of decompression sickness (DCS) meeting the definition of epidemic DCS was observed in the Shaw AFB Physiological Training Program. There were 10 cases of chamber-induced altitude DCS observed. Internal and external investigations focused on time, place, person, and environment. No temporal trend was observed. Chamber, masks, regulators, crew positions, and oxygen sources revealed no defects. Among the cases, mean age was 27 yr. Peak altitude in four cases was 35,000 ft and in the other six cases was 25,000 ft. Six had joint pain, one skin symptoms, and three neurological findings. Four were treated with 100% ground-level oxygen and six with hyperbaric oxygen. Four were students and six were inside observers (IO). Four were women and six men. In the IO, where four of the six were women, no gender effect was seen. Examining the IO monthly exposure load (exposures per month) against DCS suggested a dose-response relationship. This relationship held true when 4 yr of Shaw AFB IO data was studied. Indeed, Poisson regression analysis demonstrated a statistically significant 2.1-fold rise in DCS risk with each monthly exposure. Consequently, the number of exposures per month may need to be considered when devising IO schedules.

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.

A 'delayed' counting method to determine indoor Rn-222 levels indirectly

CERN Document Server

Iannopollo, V; Trimarchi, M; Tripepi, M G; Vermiglio, G

2001-01-01

A new indirect and 'delayed' way is presented to determine indoor concentration of Rn-222 by best-fitting methods. If a rapid knowledge of Rn-222 levels is required and if a detection system is not available in situ, it is possible to obtain concentration of radioactive gas by determining of 'delayed' counts of Po-214. The 'delay' time consists of two or three hours. The method is based on the use of cellulose filters for particulate collection and on the analysis of samples by alpha spectroscopy. It is also possible to obtain concentrations of short-lived radon daughters Po-218, Pb-214, Bi-214, which are very important quantities in a medical framework.

Nurses' impact on quality of care: lessons from RN4CAST

Directory of Open Access Journals (Sweden)

Walter Sermeus

2015-12-01

Full Text Available Introduction: The RN4CAST - study (acronym for Nurse Forecasting in Europe was launched in 2009 and ended in 2011 under the European Union's Seventh Framework Programme. The aim of the RN4CAST-study was to study how features of work environments and qualifications of the nurse workforce impact nurse retention, burnout among nurses and patient outcomes. Methods: The study was conducted in twelve European countries and was conducting a cross-sectional survey in 500 hospitals in which more than 33,000 nurses and more than 11,000 patients were involved. These data were linked to patient outcome data from administrative databases. Results: The study showed that patient outcomes such as patient mortality and patient satisfaction is highly related to nurse staffing characteristics such as patient-to-nurse ratios, nurse qualification and nursing work environment. Also nurse outcomes such as burnout, intention-to-leave, job satisfaction are related to staffing adequacy and nursing work environment. Discussion and conclusion: The RN4CAST study generated a large evidence base of nurse workforce issues across European health systems which is quite unique in terms of the number and qualification of nursing staff, the quality of working environments, burnout rates, job satisfaction rates, intention-to-leave rates that can be used for policy making.

Decompression tables for inside chamber attendants working at altitude.

Science.gov (United States)

Bell, James; Thombs, Paul A; Davison, William J; Weaver, Lindell K

2014-01-01

Hyperbaric oxygen (HBO2) multiplace chamber inside attendants (IAs) are at risk for decompression sickness (DCS). Standard decompression tables are formulated for sea-level use, not for use at altitude. At Presbyterian/St. Luke's Medical Center (Denver, Colorado, 5,924 feet above sea level) and Intermountain Medical Center (Murray, Utah, 4,500 feet), the decompression obligation for IAs is managed with U.S. Navy Standard Air Tables corrected for altitude, Bühlmann Tables, and the Nobendem© calculator. IAs also breathe supplemental oxygen while compressed. Presbyterian/St. Luke's (0.83 atmospheres absolute/atm abs) uses gauge pressure, uncorrected for altitude, at 45 feet of sea water (fsw) (2.2 atm abs) for routine wound care HBO2 and 66 fsw (2.8 atm abs) for carbon monoxide/cyanide poisoning. Presbyterian/St. Luke's provides oxygen breathing for the IAs at 2.2 atm abs. At Intermountain (0.86 atm abs), HBO2 is provided at 2.0 atm abs for routine treatments and 3.0 atm abs for carbon monoxide poisoning. Intermountain IAs breathe intermittent 50% nitrogen/50% oxygen at 3.0 atm abs and 100% oxygen at 2.0 atm abs. The chamber profiles include a safety stop. From 1990-2013, Presbyterian/St. Luke's had 26,900 total IA exposures: 25,991 at 45 fsw (2.2 atm abs) and 646 at 66 fsw (2.8 atm abs); there have been four cases of IA DCS. From 2008-2013, Intermountain had 1,847 IA exposures: 1,832 at 2 atm abs and 15 at 3 atm abs, with one case of IA DCS. At both facilities, DCS incidents occurred soon after the chambers were placed into service. Based on these results, chamber inside attendant risk for DCS at increased altitude is low when the inside attendants breathe supplemental oxygen.

Tracing submarine groundwater discharge in the NE Gulf of Mexico by 222Rn

International Nuclear Information System (INIS)

Young, J.E.; Burnett, W.C.; Chanton, J.P.; Cable, P.H.; Corbett, D.R.

1993-01-01

Inputs of freshwater and dissolved components to the ocean by submarine groundwater discharge (SGD) have been largely neglected as source functions for biogeochemical budgets. In order to locate and quantify groundwater inputs, a tracing technique has been developed using 222 Rn, a member of the natural 238 U decay-series. Because 222 Rn has a short half-life (t 1/2 = 3.84 days), is an inert gas, is relatively easy to measure at low concentrations, and has concentrations in groundwater several orders of magnitude greater than seawater, it should make an excellent tracer. Excess 222 Rn concentrations far above ''normal'' ocean values were found in the bottom waters of the northeastern Gulf of Mexico, which suggests this region has significant groundwater discharge. After measuring high water column inventories of excess 222 Rn in this region, an advection/diffusion model was applied to evaluate potential benthic sources of radon. The model is designed to account for sediment diffusion of radon and includes a groundwater term for advective flow into the overlying water. Flow rates and concentrations are adjusted in the model to balance the large difference in the measured water column inventories and the inventory predicted by sediment diffusion alone. The vertical diffusive/advective transport determines the shape of the concentration gradient and fluxes at the sediment-water interface are calculate based on these terms. The authors work shows that SGD could account for as much as 95% of the radon inventory in these offshore waters

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

Radiation measurements in Egyptian pyramids and tombs -- occupational exposure of workers and the public

Energy Technology Data Exchange (ETDEWEB)

Bigu, J; Hussein, Mohamed I; Hussein, A Z

2000-02-01

A radiation survey of seven archaeological sites within Egyptian pyramids and tombs has been conducted in the Saggara area. Measurements were made of radon ({sup 222}Rn) and its short-lived decay products (progeny), as well as thoron ({sup 220}Rn) progeny and {gamma}-radiation. The results of these measurements have been used to calculate the maximum annual effective dose (MAD) and other important occupational radiation exposure variables. It was found that for the limited time to which occupational workers and visitors were exposed, their respective MAD values were lower than that recommended by the regulatory agency (i.e., 20 mSv per year for occupational workers and 1 mSv in a year for the public). However, it is shown that if the exposure times for occupational workers were to increase to 'normal' working schedules their MAD would be exceeded at three archaeological sites. Implementation of improved ventilation practices is recommended in those sites to reduce the exposure to occupational workers were their working schedules to be significantly increased. It is also recommended that further monitoring be conducted in the future to verify these results.

Radiation measurements in Egyptian pyramids and tombs -- occupational exposure of workers and the public

International Nuclear Information System (INIS)

Bigu, J.; Hussein, Mohamed I.; Hussein, A.Z.

2000-01-01

A radiation survey of seven archaeological sites within Egyptian pyramids and tombs has been conducted in the Saggara area. Measurements were made of radon ( 222 Rn) and its short-lived decay products (progeny), as well as thoron ( 220 Rn) progeny and γ-radiation. The results of these measurements have been used to calculate the maximum annual effective dose (MAD) and other important occupational radiation exposure variables. It was found that for the limited time to which occupational workers and visitors were exposed, their respective MAD values were lower than that recommended by the regulatory agency (i.e., 20 mSv per year for occupational workers and 1 mSv in a year for the public). However, it is shown that if the exposure times for occupational workers were to increase to 'normal' working schedules their MAD would be exceeded at three archaeological sites. Implementation of improved ventilation practices is recommended in those sites to reduce the exposure to occupational workers were their working schedules to be significantly increased. It is also recommended that further monitoring be conducted in the future to verify these results

Anvender vi det optimale dosisregime for phenoxymethylpenicillin til børn mellem 0-10 år ?

DEFF Research Database (Denmark)

Glerup, Mia; Rittig, Søren; Veirum, Jens Erik

2011-01-01

fået anlagt i.v. adgang. 20 børn skal indtage phenoxymethylpenicillin mikstur 25 mg/kg og 20 børn skal indtage 50 mg/kg. Blodprøver udtages 0-7 timer efter indtagelsen. Metode 2: Koncentrationen af penicillinet i blodprøverne bestemmes ved at måle hæmningszonen for Streptococcus Pyogenes på en...... agarplade påsat patientserum. Herefter sammenlignes med hæmningszonerne for Streptococcus Pyogenes på en anden agarplade påsat kendte penicillinkoncentrationer i intervallet 0,5-32 μg/ml (Standard disk diffusion bioassay). Resultater. To børn er færdigundersøgt. Begge havde maksimal koncentration 1 time...

Aging studies of resistive bulk Micromegas chambers for the ATLAS muon spectrometer upgrade

CERN Document Server

Spencer, Katie Louise

2017-01-01

A long-term operation study is presented as a probe of the aging properties of two bulk-resistive Micromegas chambers installed at the GIF$^{++}$ Gamma Irradiation Facility at CERN. Trends in the instantaneous chamber current, recorded over $\\approx$ 500 days of sustained exposure to the GIF$^{++}$ high intensity photon source, are analysed as a function of time in order to identify any signs of detector aging. As part of the study, additional variations in the current due to the changing external conditions of the chambers must be corrected for in order to isolate any aging effects. These include the changing chamber positions with respect to the photon source and the temperature and pressure fluctuations of the detector gas medium. Due to a number of subsets of the total irradiation period in which the exact detector positions are unknown, the aging study at the present time remains inconclusive. As a result, an alternative long-term aging study utilising the instantaneous chamber dark currents is suggested...

Stability results of a free air ionization chamber in standard mammography beams

International Nuclear Information System (INIS)

Silva, Natalia F.; Xavier, Marcos; Vivolo, Vitor; Caldas, Linda V.E.

2015-01-01

Free air ionization chambers are absolute dosimeters, because they can measure basic physical quantities directly without the need of their calibration in a standard radiation beam. They are used for measuring exposure and air kerma in X and gamma radiation beams. The Calibration Laboratory (LCI) of IPEN has a free air ionization chamber of the cylindrical type for low energies. The characterization of this ionization chamber was already performed and reported in a previous study. After a modification in the support of the micrometers used for the movement of the internal cylinder devices, the tests were redone. The objective of this work was to present the new alignment protocol of the free air ionization chamber in low energies of X-ray beams of standard mammography qualities, assuring the positioning reproducibility, and new results of stability tests performed with the application of this protocol will be presented. (author)

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.

Association between Interleukin-1 Receptor Antagonist (IL1RN) Variable Number of Tandem Repeats (VNTR) Polymorphism and Pulmonary Tuberculosis.

Science.gov (United States)

Hashemi, Mohammad; Naderi, Mohammad; Ebrahimi, Mahboubeh; Amininia, Shadi; Bahari, Gholamreza; Taheri, Mohsen; Eskandari-Nasab, Ebrahim; Ghavami, Saeid

2015-02-01

Macrophages and T-lymphocytes are involved in immune response to Mycobacterium tuberculosis. Macrophage produces interleukin (IL)-1 as an inflammatory mediator. IL-1 receptor antagonist (IL1-Ra) is a natural antagonist of IL-1 receptors. In this study we aimed to examine the possible association between the variable number of tandem repeats (VNTR) of the IL-1 receptor antagonist (IL1RN) gene and pulmonary tuberculosis (TB) in a sample of Iranian population. Our study is a case-control study and we examined the VNTR of the IL1RN gene in 265 PTB and 250 healthy subjects by PCR. Neither the overall chi-square comparison of PTB and control subjects nor the logistic regression analysis indicated any association between VNTR IL1RN polymorphism and PTB. Our data suggest that VNTR IL1RN polymorphism may not be associated with the risk of PTB in a sample of Iranian population. Larger studies with different ethnicities are needed to find out the impact of IL1RN VNTR polymorphism on risk of developing TB.

RN-to-BSN Students' Quality Improvement Knowledge, Skills, Confidence, and Systems Thinking.

Science.gov (United States)

Trent, Peggy; Dolansky, Mary A; DeBrew, Jacqueline Kayler; Petty, Gayle M

2017-12-01

Little evidence demonstrates that RN-to-baccalaureate nursing (BSN) graduates have met The Essentials of Baccalaureate Education for Professional Nursing Practice-specifically, evidence of the graduates' organizational and systems leadership related to quality care and patient safety. This BSN Essentials reflects the QSEN quality improvement (QI) competency. The purpose of this pilot study was to develop and test an assessment strategy to measure RN-to BSN students' QI competence and their perception of QI knowledge and skills. Students (N = 59) from six RN-to-BSN programs participated in a Qualtrics survey e-mailed during the last semester of their program. The majority of students (60%) reported that they did not experience QI content in their program. Scores on QI knowledge, skills, and systems thinking were low, yet the students self-reported that they were confident in their ability to perform QI. This pilot study provides an assessment strategy to measure students' competence related to QI. Nursing education has an opportunity to integrate and measure QI competence to ensure that nurses have the knowledge and skills to continually improve patient care. [J Nurs Educ. 2017;56(12):737-740.]. Copyright 2017, SLACK Incorporated.

Radon transport modelling: User's guide to RnMod3d

International Nuclear Information System (INIS)

Andersen, C.E.

2000-08-01

RnMod3d is a numerical computer model of soil-gas and radon transport in porous media. It can be used, for example, to study radon entry from soil into houses in response to indoor-outdoor pressure differences or changes in atmospheric pressure. It can also be used for flux calculations of radon from the soil surface or to model radon exhalation from building materials such as concrete. The finite-volume model is a technical research tool, and it cannot be used meaningfully without good understanding of the involved physical equations. Some understanding of numerical mathematics and the programming language Pascal is also required. Originally, the code was developed for internal use at Risoe only. With this guide, however, it should be possible for others to use the model. Three-dimensional steady-state or transient problems with Darcy flow of soil gas and combined generation, radioactive decay, diffusion and advection of radon can be solved. Moisture is included in the model, and partitioning of radon between air, water and soil grains (adsorption) is taken into account. Most parameters can change in time and space, and transport parameters (diffusivity and permeability) may be anisotropic. This guide includes benchmark tests based on simple problems with known solutions. RnMod3d has also been part of an international model intercomparison exercise based on more complicated problems without known solutions. All tests show that RnMod3d gives results of good quality. (au)

Development and construction of a specific chamber for phototoxicity test

Energy Technology Data Exchange (ETDEWEB)

Sufi, Bianca S.; Mathor, Monica B., E-mail: biancasufi@usp.br, E-mail: mathor@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Esteves-Pedro, Natalia M.; Kaneko, Telma Mary, E-mail: nataliamenves@yahoo.com.br, E-mail: tsakuda@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Fac. de Ciencias Farmaceuticas; Lopes, Patricia, E-mail: patricia.lopes@unifesp.br [Universidade Federal de Sao Paulo (UNIFESP), Diadema, SP (Brazil)

2013-07-01

Phototoxicity corresponds to the acute toxic response induced after skin exposure 'in vivo' and 'ex vivo' to certain chemicals and subsequent exposure to irradiation. Phototoxicity 'in vitro' assay is determined by viability of fibroblasts BALB/c 3T3 exposed to chemicals in the presence and absence of light. Substances identified as phototoxic are susceptible to 'in vivo' phototoxicity (OECD 432, 2004). A chamber was developed and constructed according to the guidelines OECD Toxicity Guide - 432 and ®ECVAM DB-ALM: INVITTOX N. 78. The chamber was built in stainless steel frame, with UVA lamps and dark area for negative control. The tests to qualify the chamber were performed with Sodium Lauryl Sulfate, recommended by the guides aforementioned, as negative control; and Bergamot oil (Givaudan-Roche), as positive control. Bergamot, Citrus bergamia, has, as major component, Bergapten responsible for its photosensitive activity. Both samples were diluted in Phosphate Buffered Saline with concentrations between 0.005 and 0.1 mg/mL, which were calculated by the dilution factor 1.47. These tests were performed over fibroblast BALB/c 3T3 culture and submitted to phototoxicity assay with MTS dye, under spectrophotometric reading, which allows determining the Photo Irritation Factor (PIF), what suggests that a substance with a PIF<2 predicts no phototoxicity; PIF>2 and <5 provides likely phototoxicity and PIF>5 provides phototoxicity. Sodium Lauryl Sulfate presented a PIF=1, being in accordance with the OECD. Bergamot oil has shown to be likely phototoxic with a PIF=2,475. These results provide that the chamber is qualified to be used to perform phototoxicity tests with assurance and security. (author)

Radon exposure and lung cancer

International Nuclear Information System (INIS)

Planinic, J.; Vukovic, B.; Faj, Z.; Radolic, V.; Suveljak, B.

2003-01-01

Although studies of radon exposure have established that Rn decay products are a cause of lung cancer among miners, the lung cancer risk to the general population from indoor radon remains unclear and controversial. Our epidemiological investigation of indoor radon influence on lung cancer incidence was carried out for 201 patients from the Osijek town. Ecological method was applied by using the town map with square fields of 1 km 2 and the town was divided into 24 fields. Multiple regression study for the lung cancer rate on field, average indoor radon exposure and smoking showed a positive linear double regression for the mentioned variables. Case-control study showed that patients, diseased of lung cancer, dwelt in homes with significantly higher radon concentrations, by comparison to the average indoor radon level of control sample. (author)

Implementation of a primary standard for a x-ray exposure

International Nuclear Information System (INIS)

peixoto, J.G.P.

1991-04-01

In the scientific program of the National Laboratory for Ionizing Radiation Metrology of the Instituto de Radioprotecao e Dosimetria, which belongs to the Comissao Nacional de Energia Nuclear, a free-air ionization chamber should be established as an exposure primary standard for X-rays of 100 K V to 250 K V of potential range. Preliminary results showed that the available free-air ionization chamber was suitable to be used. The absolute measurement of the radiation quantity exposure, is performed with a free-air ionization chamber. Its geometrical volume, which allows the determination of the air mass, is defined by the effective aperture area and by the length of the region where an electrical field is applied. Most of the ions produced in such volume are collected as an ionization current. Parameters related to the measurement of the quantity exposure were evaluated, such as: air absorption, scattering inside the ionization chamber, saturation, beam homogeneity, influence of beam size and influences of temperature, humidity and atmospheric pressure. Preliminary determination of correction factors has showed good results with 99.9% of repeatability and has demonstrated the reliability of the checked chamber as a standard instrument. (author)

Duration of memory loss due to electron beam exposure. Final report Jan-May 1983

Energy Technology Data Exchange (ETDEWEB)

Wheeler, T.G.; Tilton, B.M.

1983-08-01

Electron beam exposure has been shown to produce retrograde amnesia (RA). The objective of this study was to determine the duration of memory loss upon electron beam exposure. It is important to know if exposure produces a memory loss of the events which occurred in the preceding 1 sec or memory loss of the preceding minute's events. The task was a single-trial avoidance paradigm. The animal was placed in a small aversive chamber. After a 90-sec adaptation period, a door opened that provided access to a large, dark, preferred chamber. The time required for the animal to enter the preferred chamber was the measure of interest (T). Once inside the preferred chamber, a 1-sec footshock was delivered. Following the footshock by some preset delay (delta T), the animal was exposed to a 10-microsec, 10-rad electron beam (or X-ray). A second trial on the task was run 2 hr postexposure. The second trial consisted of placing the animal in the aversive chamber and monitoring the time (T') required to enter the preferred chamber. If the electron beam exposure interfered with the animal's ability to recall the shock, T' would be greatly reduced as compared with the sham controls. The exposure delay times used were delta T = 1, 3, 5, and 10 sec.

Intrinsic backgrounds from Rn and Kr in the XENON100 experiment

Energy Technology Data Exchange (ETDEWEB)

Aprile, E.; Anthony, M.; Perio, P. de; Gao, F.; Goetzke, L.W.; Greene, Z.; Lin, Q.; 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, Amsterdam (Netherlands); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); 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.; Santos, J.M.F. dos; Silva, M. [University of Coimbra, LIBPhys, 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.; Galloway, M.; Kazama, S.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F.; Wulf, J. [University of Zurich, Physik-Institut, Zurich (Switzerland); Bauermeister, B.; Calven, J.; Conrad, J.; Ferella, A.D.; Moraa, K.; Pelssers, B. [Stockholm University, AlbaNova, Oskar Klein Centre, Department of Physics, 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.; Marrodan Undagoitia, T.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Bruno, G.; Rosso, A.G.; Molinario, A.; Wang, Z. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); Budnik, R.; 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. von [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Cervantes, M.; Lang, R.F.; Masson, D.; Reichard, S. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Cussonneau, J.P.; Diglio, S.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D. [CNRS/IN2P3, Universite de Nantes, SUBATECH, IMT Atlantique, 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.; Lombardi, F.; Ni, K.; Ye, J. [University of California, Department of Physics, San Diego, CA (United States); Fieguth, A.; Murra, M.; Vargas, M.; Weinheimer, C.; Wittweg, C. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Fulgione, W. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Torino (Italy); Lindemann, S. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Messina, M. [Columbia University, Physics Department, New York, NY (United States); New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Naganoma, J.; Shagin, P. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Pienaar, J. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); University of Chicago, Department of Physics, Kavli Institute of Cosmological Physics, Chicago, IL (United States); Ramirez Garcia, D. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Reuter, C. [University of Zurich, Physik-Institut, Zurich (Switzerland); Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Lavina, L.S. [Universite Paris Diderot, CNRS/IN2P3, LPNHE, Universite Pierre et Marie Curie, Paris (France); Stein, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Trinchero, G. [INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Torino (Italy); Tunnell, C. [Nikhef and the University of Amsterdam, Amsterdam (Netherlands); University of Chicago, Department of Physics, Kavli Institute of Cosmological Physics, Chicago, IL (United States); Weber, M. [Columbia University, Physics Department, New York, NY (United States); Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Wei, Y. [University of Zurich, Physik-Institut, Zurich (Switzerland); University of California, Department of Physics, San Diego, CA (United States); Collaboration: XENON Collaboration

2018-02-15

In this paper, we describe the XENON100 data analyses used to assess the target-intrinsic background sources radon ({sup 222}Rn), thoron ({sup 220}Rn) and krypton ({sup 85}Kr). We detail the event selections of high-energy alpha particles and decay-specific delayed coincidences. We derive distributions of the individual radionuclides inside the detector and quantify their abundances during the main three science runs of the experiment over a period of ∝ 4 years, from January 2010 to January 2014. We compare our results to external measurements of radon emanation and krypton concentrations where we find good agreement. We report an observed reduction in concentrations of radon daughters that we attribute to the plating-out of charged ions on the negatively biased cathode. (orig.)

Intrinsic backgrounds from Rn and Kr in the XENON100 experiment

International Nuclear Information System (INIS)

Aprile, E.; Anthony, M.; Perio, P. de; Gao, F.; Goetzke, L.W.; Greene, Z.; Lin, Q.; Plante, G.; Rizzo, A.; Zhang, Y.; Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Hogenbirk, E.; Tiseni, A.; Agostini, F.; Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Scheibelhut, M.; Schindler, S.; Amaro, F.D.; Cardoso, J.M.R.; Lopes, J.A.M.; Santos, J.M.F. dos; Silva, M.; Arneodo, F.; Benabderrahmane, M.L.; Di Giovanni, A.; Maris, I.; Barrow, P.; Baudis, L.; Galloway, M.; Kazama, S.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F.; Wulf, J.; Bauermeister, B.; Calven, J.; Conrad, J.; Ferella, A.D.; Moraa, K.; Pelssers, B.; Berger, T.; Brown, E.; Piro, M.C.; Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindner, M.; Marrodan Undagoitia, T.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H.; Bruno, G.; Rosso, A.G.; Molinario, A.; Wang, Z.; Budnik, R.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N.; Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M.; Sivers, M. von; Cervantes, M.; Lang, R.F.; Masson, D.; Reichard, S.; Cussonneau, J.P.; Diglio, S.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D.; Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M.; Fei, J.; Lombardi, F.; Ni, K.; Ye, J.; Fieguth, A.; Murra, M.; Vargas, M.; Weinheimer, C.; Wittweg, C.; Fulgione, W.; Lindemann, S.; Messina, M.; Naganoma, J.; Shagin, P.; Pienaar, J.; Ramirez Garcia, D.; Reuter, C.; Lavina, L.S.; Stein, A.; Wang, H.; Trinchero, G.; Tunnell, C.; Weber, M.; Wei, Y.

2018-01-01

In this paper, we describe the XENON100 data analyses used to assess the target-intrinsic background sources radon ( 222 Rn), thoron ( 220 Rn) and krypton ( 85 Kr). We detail the event selections of high-energy alpha particles and decay-specific delayed coincidences. We derive distributions of the individual radionuclides inside the detector and quantify their abundances during the main three science runs of the experiment over a period of ∝ 4 years, from January 2010 to January 2014. We compare our results to external measurements of radon emanation and krypton concentrations where we find good agreement. We report an observed reduction in concentrations of radon daughters that we attribute to the plating-out of charged ions on the negatively biased cathode. (orig.)

A two-compartment exposure device for foliar uptake study

International Nuclear Information System (INIS)

Zuo, Q.; Lin, H.; Zhang, X.L.; Li, Q.L.; Liu, S.Z.; Tao, S.

2006-01-01

An airtight two-chamber exposure devise was designed for investigating foliar uptake of polycyclic aromatic hydrocarbons (PAHs) by plants. The upper and the bottom chambers of the device were air-tightly separated by an aluminum foil and the plant aerial tissues and roots were exposed in the two chambers, respectively. The device was tested using maize exposed to several PAH species. Positive correlations between air and aerial tissue concentrations of the exposed PAH species were revealed. PAHs spiking in the culture solution had no influence on the leaf concentrations. -- A two-compartment gastight exposure device was developed for investigation of foliar uptake of PAHs by plants

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...

Application of {sup 222} Rn as a tracer of groundwater discharge at the coastal zone of Ubatuba, Sao Paulo State, Brazil; Aplicacao de {sup 222} Rn como tracador da descarga de aguas subterraneas na regiao costeira de Ubatuba, Sao Paulo

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Joselene de; Farias, Luciana A.; Mazzilli, Barbara P. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Dept. de Radiometria Ambiental]. E-mail: jolivei@net.ipen.br; Burnett, William C. [Florida State Univ., Tallahassee, FL (United States); Saraiva, Elisabete de S.B. e; Furtado, Valdenir V. [Sao Paulo Univ., SP (Brazil). Inst. Oceanografico. Dept. de Oceanografia Quimica e Geologica

2002-07-01

Submarine groundwater discharge (SGD) and recycled seawater can provide chemical constituents to coastal zone, representing an important material flux pathway from land to sea in some areas. Geochemical tracers, like {sup 222} Rn and {sup 226} Ra, are advantageous for regional-scale assessment of SGD, because their signals represent values integrated through the water column that removes small-scale variations. These radionuclides are usually enriched in groundwater compared to seawater, can be measured at very low concentrations and are conservative. This work reports preliminary results of a study carried out in a series of small embayements of Ubatuba, Sao Paulo State-Brazil, covering latitudes between 23 deg 26{sup '}S and 23 deg 46{sup '}S and longitudes between 45 deg02{sup '}W and 45 deg 11{sup '}W. The main aims of this research were to set up an analytical method to assess {sup 222} Rn and {sup 226} Ra activities in seawater samples and to apply the excess {sup 222} Rn inventories obtained to estimate the submarine groundwater discharge. Measurements made during 2001/2002 included {sup 222} Rn and {sup 226} Ra in seawater, {sup 222} Rn in sediment, seawater and sediment physical properties. (author)

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)

Seasonal variations of 222Rn and SGD fluxes to Ubatuba embayments, Sao Paulo

International Nuclear Information System (INIS)

Oliveira, J.; Costa, P.; Braga, E.S.

2006-01-01

We describe here an application of excess 222 Rn to estimate submarine groundwater discharge in a series of small embayments of Ubatuba, Sao Paulo State, Brazil. Excess 222 Rn inventories obtained in 11 vertical profiles varied from (3.3±1.1) x 10 3 to (19±5) x 10 3 dpm x m -2 . The estimated total fluxes required to support the inventories varied from (0.6±0.2) x 10 3 to (3.4±0.9) x 10 3 dpm x m -2 x d -1 . Considering these results, the submarine groundwater discharge advective rates necessary to balance the sub-pycnocline fluxes calculated in Ubatuba embayments ranged from 0.06 to 1.9 cm x d -1 . During the period of this investigation (from March/03 to May/2004), the highest 222 Rn in excess inventories were observed late in the summer season (March). Taking into account all vertical profiles established, the relative variability was 67%. Although, if we consider only the fluxes determined in both Flamengo and Fortaleza embayments, the relative variation was 21%. (author)

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.)

Rn3D: A finite element code for simulating gas flow and radon transport in variably saturated, nonisothermal porous media

International Nuclear Information System (INIS)

Holford, D.J.

1994-01-01

This document is a user's manual for the Rn3D finite element code. Rn3D was developed to simulate gas flow and radon transport in variably saturated, nonisothermal porous media. The Rn3D model is applicable to a wide range of problems involving radon transport in soil because it can simulate either steady-state or transient flow and transport in one-, two- or three-dimensions (including radially symmetric two-dimensional problems). The porous materials may be heterogeneous and anisotropic. This manual describes all pertinent mathematics related to the governing, boundary, and constitutive equations of the model, as well as the development of the finite element equations used in the code. Instructions are given for constructing Rn3D input files and executing the code, as well as a description of all output files generated by the code. Five verification problems are given that test various aspects of code operation, complete with example input files, FORTRAN programs for the respective analytical solutions, and plots of model results. An example simulation is presented to illustrate the type of problem Rn3D is designed to solve. Finally, instructions are given on how to convert Rn3D to simulate systems other than radon, air, and water

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.)

The correlation between exhalation from rocks and indoor concentration of 222Rn in the Sydney area

International Nuclear Information System (INIS)

MCKenzie, D.R.; Lenzen, M.; Solomon, S.B.

2001-01-01

The results of a survey of indoor 222 Rn concentrations of 350 dwellings in the Sydney area are combined with measurements of 222 Rn exhalation rates of principal rock types in the survey area. A linear regression is predicted which yields a positive regression coefficient of b=2.4±0.3, a constant of a=3.4±0.5, and a correlation coefficient of R 2 =0.15. This correlation was found to be highly significant by using three different statistical tests. The ratio of the indoor 222 Rn concentrations in dwellings built on the two dominant rock types, the Wianamatta Shale and the Hawkesbury Sandstone, was found to be about 1.6. Copyright (2001) Australasian Radiation Protection Society Inc

Rn-222 concentrations in private well water and in river water around Ningyo Toge area

Energy Technology Data Exchange (ETDEWEB)

Yunoki, Eiji [Okayama, Prefectural Inst. for Environmental Science and Public Health (Japan)

1997-02-01

The Ningyo-Toge Works of Power Reactor and Nuclear Fuel Development Corporation have started the pilot plant for uranium refining and conversion in 1984 and thereafter been producing 6-uranium fluoride, which is a raw material for an uranium concentration plant. The operation of prototype reactor has started since 1989. In this study, radioactive contamination around the works under these circumstances has been monitored in the respects of Rn concentrations in well water and river one for more than 10 years. The radioactivities of well water sampled at 4 points in this area were in a range of 0.6-82.9 Bq/l. The differences in the activities seemed to be depending on petrological properties. For the river water, the Rn concentration was determined at 13 points in the area. Seasonal changes in the Rn concentrations were not significant (p<0.05) but there were significant changes among years during 1985-1995. Further, the radioactive levels of soils collected from riverbed at 5 points were significantly different both for {sup 238}U and {sup 226}Ra, but the ratios of {sup 238}U/{sup 226}Ra were consistent. Furthermore, there was no correlation between {sup 226}Ra and {sup 222}Rn concentrations in the river water. (M.N.)

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...

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)

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

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...

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)

Fresh Versus Marine Submarine Groundwater Discharge: How 222Rn Might Help Distinguish These Two Sources

Science.gov (United States)

Smith, C. G.; Cable, J. E.; Martin, J. B.; Roy, M.

2008-05-01

Pore water distributions of 222Rn (t1/2 = 3.83 d), obtained during two sampling trips 9-12 May 2005 and 6-8 May 2006, are used to determine spatial and temporal variations of fluid discharge from a seepage face located along the mainland shoreline of Indian River Lagoon, Florida. Porewater samples were collected from a 30 m transect of multi-level piezometers and analyzed for 222Rn via liquid scintillation counting; the mean of triplicate measurements was used to represent the porewater 222Rn activities. Sediment samples were collected from five vibracores (0, 10, 17.5, 20, and 30 m offshore) and emanation rates of 222Rn (sediment supported) were determined using a standard cryogenic extraction technique. A conceptual 222Rn transport model and subsequent numerical model were developed based on the vertical distribution of dissolved and sediment-supported 222Rn and applicable processes occurring along the seepage face (e.g. advection, diffusion, and nonlocal exchange). The model was solved inversely with the addition of two Monte Carlo (MC) simulations to increase the statistical reliability of three parameters: fresh groundwater seepage velocity (v), irrigation intensity (α0), and irrigation attenuation (α1). The first MC simulation ensures that the Nelder-Mead minimization algorithm converges on a global minimum of the merit function and that the parameters estimates are consistent within this global minimum. The second MC simulation provides 90% confidence intervals on the parameter estimates using the measured 222Rn activity variance. Fresh groundwater seepage velocities obtained from the model decrease linearly with distance from the shoreline; seepage velocities range between 0.6 and 42.2 cm d-1. Based on this linear relationship, the terminus of the fresh groundwater seepage is approximately 25 m offshore and total fresh groundwater discharge for the May-2005 and May-2006 sampling trips are 1.16 and 1.45 m3 d-1 m-1 of shoreline, respectively. We hypothesize

Tværprofessionelt samarbejde om udsathed hos børn og unge

DEFF Research Database (Denmark)

Villumsen, Anne Marie Anker; Jakobsen, Ida Skytte; Lund, Jens Hansen

2015-01-01

begreb og fænomen, som ikke lader sig indfange i en absolut og statisk definition. Potentialet for både praksis og uddannelser ligger derfor i en erkendelse heraf. Samtidig synes der at være potentiale i, at man i hver enkelt samarbejdskonstellation og kontekst operationaliserer og præciserer......, at tværprofessionelt samarbejde er meget udbredt indenfor socialt arbejde med udsathed hos børn og unge, og det er tydeligt, at der er mange måder, hvorpå man kan samarbejde tværprofessionelt. Samtidig er både tværprofessionelt samarbejde såvel som udsathed hos børn og unge begge vanskelige og upræcise begreber og...

Integrating evidence-based practice into RN-to-BSN clinical nursing education.

Science.gov (United States)

Oh, Eui Geum; Kim, Sunah; Kim, So Sun; Kim, Sue; Cho, Eun Yong; Yoo, Ji-Soo; Kim, Hee Soon; Lee, Ju Hee; You, Mi Ae; Lee, Hyejung

2010-07-01

This study examines the effects of integrating evidence-based practice (EBP) into clinical practicum on EBP efficacy and barriers to research utilization among Korean RN-to-BSN students. A one-group pretest-posttest design was used. Eighty-one students were recruited from a school of nursing in Korea. Evidence-based practice clinical practicum was composed of two consecutive programs during one semester. Lectures, individual mentoring on EBP practicum, small group, and wrap-up conferences were provided. Outcomes of EBP efficacy and barriers to research utilization were analyzed using paired t tests for 74 final participants. Evidence-based practice efficacy scores increased significantly (p effectiveness of EBP education among RN-to-BSN students. These results may help health educators develop effective educational strategies to integrate EBP concepts into a clinical practicum. Copyright 2010, SLACK Incorporated.

Loss of Magnet® Designation and Changes in RN Work Engagement: A Report on How 1 Hospital's Culture Changed Over Time.

Science.gov (United States)

Wonder, Amy Hagedorn; York, Jacki; Jackson, Kathryn L; Sluys, Teresa D

2017-10-01

The aim of this study was to examine the loss of Magnet® designation and how RNs' work engagement changed at 1 community hospital. The importance of RN work engagement to promote quality and safety is widely recognized in healthcare. Ongoing consistent research is critical to determine what organizational structures are needed to support RN work engagement. This was a comparative, descriptive, correlational study of RN cohorts at 2 time points: time 1 (T1), in 2011 during Magnet designation (n = 119), and time 2 (T2), in 2016, approximately 2 years after the loss of Magnet designation (n = 140). The cohort of RNs at T2 reported significantly lower work engagement in the time period after the loss of Magnet designation when compared with the RN cohort at T1 during Magnet designation (P ≤ .0002). These results provide insights for clinical leaders striving to support a culture of RN work engagement and quality care.

Humidity correction in the standard measurement of exposure

International Nuclear Information System (INIS)

Ibaraki, Yasuyuki; Katoh, Akira

1980-01-01

This paper deals with the humidity correction to be made in the standard measurement of the exposure to the measured ionization current in the humid air for the purpose of excluding the influence of the water vapour that is not included in the definition of the exposure. First, formulae giving the humidity correction factors for a parallel plate free air chamber and a cavity chamber have been derived respectively in the case where the contributions of air and water vapour to the ionization are independent. Next, in the case where the contributions are not independent, i.e., the Jesse effect is taken into account, a formula to obtain the W-value for humid air has been derived on the basis of the Niatel's experimental result. Using this formula, formulae to obtain the humidity correction factors for the free air chamber and the cavity chamber are derived. The humidity calculated by the latter formulae show good agreements with the results by Niatel and Guiho, respectively. (author)

Whole-body nanoparticle aerosol inhalation exposures.

Science.gov (United States)

Yi, Jinghai; Chen, Bean T; Schwegler-Berry, Diane; Frazer, Dave; Castranova, Vince; McBride, Carroll; Knuckles, Travis L; Stapleton, Phoebe A; Minarchick, Valerie C; Nurkiewicz, Timothy R

2013-05-07

Inhalation is the most likely exposure route for individuals working with aerosolizable engineered nano-materials (ENM). To properly perform nanoparticle inhalation toxicology studies, the aerosols in a chamber housing the experimental animals must have: 1) a steady concentration maintained at a desired level for the entire exposure period; 2) a homogenous composition free of contaminants; and 3) a stable size distribution with a geometric mean diameter generation of aerosols containing nanoparticles is quite challenging because nanoparticles easily agglomerate. This is largely due to very strong inter-particle forces and the formation of large fractal structures in tens or hundreds of microns in size (6), which are difficult to be broken up. Several common aerosol generators, including nebulizers, fluidized beds, Venturi aspirators and the Wright dust feed, were tested; however, none were able to produce nanoparticle aerosols which satisfy all criteria (5). A whole-body nanoparticle aerosol inhalation exposure system was fabricated, validated and utilized for nano-TiO2 inhalation toxicology studies. Critical components: 1) novel nano-TiO2 aerosol generator; 2) 0.5 m(3) whole-body inhalation exposure chamber; and 3) monitor and control system. Nano-TiO2 aerosols generated from bulk dry nano-TiO2 powders (primary diameter of 21 nm, bulk density of 3.8 g/cm(3)) were delivered into the exposure chamber at a flow rate of 90 LPM (10.8 air changes/hr). Particle size distribution and mass concentration profiles were measured continuously with a scanning mobility particle sizer (SMPS), and an electric low pressure impactor (ELPI). The aerosol mass concentration (C) was verified gravimetrically (mg/m(3)). The mass (M) of the collected particles was determined as M = (Mpost-Mpre), where Mpre and Mpost are masses of the filter before and after sampling (mg). The mass concentration was calculated as C = M/(Q*t), where Q is sampling flowrate (m(3)/min), and t is the sampling

Functional characterization of the origin of replication of pRN1 from Sulfolobus islandicus REN1H1.

Directory of Open Access Journals (Sweden)

Chijioke J Joshua

Full Text Available Plasmid pRN1 from Sulfolobus islandicus REN1H1 is believed to replicate by a rolling circle mechanism but its origin and mechanism of replication are not well understood. We sought to create minimal expression vectors based on pRN1 that would be useful for heterologous gene expression in S. acidocaldarius, and in the process improve our understanding of the mechanism of replication. We constructed and transformed shuttle vectors that harbored different contiguous stretches of DNA from pRN1 into S. acidocaldarius E4-39, a uracil auxotroph. A 232-bp region 3' of orf904 was found to be critical for pRN1 replication and is therefore proposed to be the putative origin of replication. This 232-bp region contains a 100-bp stem-loop structure believed to be the double-strand origin of replication. The loop of the 100-bp structure contains a GTG tri-nucleotide motif, a feature that was previously reported to be important for the primase activity of Orf904. This putative origin and the associated orf56 and orf904 were identified as the minimal replicon of pRN1 because transformants of plasmids lacking any of these three features were not recovered. Plasmids lacking orf904 and orf56 but harboring the putative origin were transformable when orf904 and orf56 were provided in-trans; a 75-bp region 5' of the orf904 start codon was found to be essential for this complementation. Detailed knowledge of the pRN1 origin of replication will broaden the application of the plasmid as a genetic tool for Sulfolobus species.

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

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.)

Temperature changes in the pulp chamber during dentin ablation with Er:YAG laser

Science.gov (United States)

Zhang, Xianzeng; Zhao, Haibin; Zhan, Zhenlin; Guo, Wenqing; Xie, Shusen

2012-12-01

To examine the temperature changes in the pulp chamber during cavity preparation in dentin with the Er:YAG laser (2940 nm), a total 20 intact premolars teeth were divided into 4 groups for dentin ablation with different radiant exposures at 4Hz and 8Hz with and without water spray. A K-type thermocouple was used to monitor the temperature changes in pulp chamber during laser treatment. The total time of irradiation was 70 sec. the water spray rate was 3 mL/min. It showed that maximum temperature rise increases with the increasing of radiant exposure and pulse repetition rate and the additional water cooling during laser ablation can significantly reduce the temperature rise in pulp chamber which will benefit to avoid or reduce thermal damage to tooth structure and dental pulp. The highest rise of temperature in the pulp was achieved with 20 J/cm2 and 8 Hz (19.83°C ). For all sample without water spray, the rise of temperature was exceed 5 °C . In contrast, with water spray, the temperature rise in the pulp can be firmly controlled under 1°C. The results also indicated that ablation rate and efficiency can be enhanced by increasing the incident radiant exposure and pulse repetition rate, which simultaneously producing more heat accumulation in dental tissue and causing thermal damage to dental tissue. By applying an additional water spray, thermal damage can be significantly reduced in clinical application.

Rn-Gas Concentration and Working Level Measurements Using SSNTD in Uranium Exploration Galleries Allouga Mine, Sinai, Egypt

International Nuclear Information System (INIS)

Abdel-Monem, A.A.; Hassan, S.F.; Abdel-Kader, F.H.; El-Naggar, A.M.; Essia, H.M.; Abdel-Hafez, A.A.

2008-01-01

Measurements of Rn-gas concentrations and Working Level (WL), were carried out in the U-exploration galleries at El- Allouga Mine, Sinai, Egypt by passive techniques (SSNTD) during the four seasons ( Summer, Fall, Winter and Spring) using four different detector types: CR-39, MK, CN-85 and LR-115.Twenty eight (28) stations were chosen for this purpose reflecting different environmental conditions as measurement sites within the galleries. The Rn-gas concentrations , in the summer period ranged from 25.86 to 44.2 pCi/l in the ventilated stations and from 488.98 to 611.16 pCi/l in the non-ventilated stations. In the fall period , the average Rn-gas concentrations in the ventilated stations ranged from 31.61 to 56.36 pCi/l while in the non-ventilated stations from 457.61 to 621.52 pCi/l. In the winter period, the average Rn-gas concentrations in the ventilated stations ranged from 27.59 to 66.45 pCi/l while in the non- ventilated stations from 499.09 to 603.81 pCi/l. In the spring the Rn-gas concentrations ranged from 30.8 to 46.77 pCi/l in the ventilated stations, whereas, in the non-ventilated stations from 404.06 to 445.18 pCi/l. The (WL), in the summer period, ranged from 0.143 to 0.247 in the ventilated sector and from 4.408 to 5.497 in the non-ventilated stations .In fall, the( WL) ranged from 0.166 to 0.295 in the ventilated stations and from 4.123 to 5.624 in the non-ventilated stations. In the winter, the (WL) ranged from 0.105 to 0.37 in the ventilated stations and from 4.138 to 5.26 in the non-ventilated stations. In the spring, the (WL) in the ventilated stations ranged from 0.152 to 0.241 and from 3.696 to 4.087 in the non-ventilated stations. These results indicate that: i)The low measured Rn gas and (WL) values in the ventilated stations reflect the effect of variations in meteorological conditions on (WL) determination where the air flow carries the Rn-gas before it decays and the daughters are plated onto the SSNTD . ii) The larger ranges for Rn

Report from Workshop on VOCs in diving chambers

International Nuclear Information System (INIS)

Crosbie, A.; Simpson, M.

2000-05-01

This report of the 'Setting the Standards' workshop on the problems of volatile organic compounds (VOCs) in diving in offshore operations, sponsored jointly by the UK Health and Safety Executive Offshore Safety Division and the Stolt Rockwater Joint Venture, gives details of the papers presented covering the chemical contamination of diver's atmosphere, sampling protocols and methods, analytical procedures used for VOCs in hyperbaric chambers, and contamination in buildings. The setting of exposure limits in the UK, the derivation of threshold limiting values (TVLs), the selection of Tenax tubes for atmospheric sampling, organic contaminant monitoring, and NASA's approach to contamination in the space environment are examined, and dealing with contamination problems in a submarine atmosphere, and the simulation of a condensate spillage in a diving bell are discussed. Guidelines for the measurement of VOCs in hyperbaric chambers are given in the appendices

Chamber personnel's use of Nitrox 50 during hyperbaric oxygen treatment: a quality study--research report.

Science.gov (United States)

Hansen, Marco B; Jansen, Tejs; Sifakis, Michael B; Hyldegaard, Ole; Jansen, Erik C

2013-01-01

We aimed to evaluate the feasibility and safety of using Nitrox 50 as breathing gas during attendance in a multiplace hyperbaric chamber. Paper logs between Jan.-Dec. 2011 were reviewed to analyze nitrogen gas-loading, actual bottom time, total bottom time and surface interval time. With the use of the Norwegian Diving Tables nitrogen gas-loading was converted to Repetitive Group Letters. Symptoms of decompression sickness and health problems related to hyperbaric exposures were registered at weekly staff meetings. The chamber personnel breathed chamber air or Nitrox 50. 1,207 hyperbaric exposures were distributed to five chamber attendants and technicians, 14 doctors, and six nurses. Nitrox 50 was inhaled on 978 occasions (81.0%). Median nitrogen gas-loading after first pressurization complied with Repetitive Group Letter A (range A-E), second to C (range A-F), third to D (range A-F), fourth to E (range C-H), fifth to F (range C-H), and sixth to E (range B-G). No symptoms of decompression sickness were reported (95% CI 0.00-0.33%). Breathing Nitrox 50 during repetitive hyperbaric sessions seems to be feasible and safe while meeting high demands in number of treatment sessions and patient flow and with fewer people employed in the hyperbaric unit.

Implementation of a primary standard for x-ray exposure

International Nuclear Information System (INIS)

Peixoto, Jose Guilherme Pereira

1991-04-01

In the scientific program of the National Laboratory for Ionizing Radiation Metrology of the Instituto de Radioprotecao e Dosimetria, which belongs to the Comissao Nacional de Energia Nuclear, a free-air ionization chamber should be established as an exposure primary standard for X-ray s of 10OKV to 250kV of potential range. Preliminary results showed that the available free-air ionization chamber was suitable to be used. The absolute measurement of the radiation quantity exposure, is performed with a free-air ionization chamber. Its geometrical volume, which allows the determination of the air mass, is defined by the effective aperture area and by the length of the region where an electrical field is applied. Most of the ions produced in such volume are collected as an ionization current. Since the collecting rod is small, and positioned far away from the X-ray beam, only a negligible fraction of ionization (0,01 %) is lost due to interactions with it. Parameters related to the measurement of the quantity exposure were evaluated, such as: air absorption, scattering inside the ionization chamber, saturation , beam homogeneity, influence Of beam size and influences of temperature, humidity and atmospheric pressure.Preliminary determination of correction factors has showed good results with 99.9% of repeatability and has demonstrated the reliability of the checked chamber as a standard instrument. (author)

Measurement of air kerma rate for Cs-137 using different ionization chambers

International Nuclear Information System (INIS)

Mohammed, K. T. A.

2013-07-01

Due to the importance of radiation doses in medical field quality assurance should be established in order to maintain a reasonable balance between the purpose of application and exposure. This study had been carried out to achieve quality control for protection based on air kerma rate. Measurements were performed by using Cs-137 for the comparison of two working ionization chambers in secondary standard dosimetry laboratory of Sudan. Spherical ionization chamber L S-01 1000 cc S/N 912 and Farmer ionization chamber 2675 A 600 cc S/N 0511, respectively. The results obtained from this study have been represented as mean and their standard deviations shown in most cases remains at 5% uncertainly. Comparison between kinetic energy released per unit mass in air rate (air kerma rate) were obtained by using spherical ionization chamber L S-01 1000 cc S/N 912 and results have been determined using inverse square law. The differences have been represented as means and standard deviations with significant P-value less than 0.05. Spherical ionization chamber gives accurate, reproducible results with acceptable uncertainty which is more suitable for calibration of radiation detectors.(Author)

Fail-safe ion chamber errant beam detector tailored for personnel protection

International Nuclear Information System (INIS)

Plum, M.A.; Browman, A.A.; Brown, D.; Lee, D.M.; McCabe, C.W.

1989-01-01

This fail-safe ion chamber system is designed to be part of the personnel safety system (PSS) for the Los Alamos neutron Scattering Center (LANSCE) at the Los Alamos National Laboratory. Its job is to protect the occupants of the experimental areas from large radiation doses caused by errant beam conditions during beam transport from the Proton Storage Ring (PSR) to the LANSCE neutron spallation target. Due to limited shielding between the beam transport line and the experimental area only if the beam losses in the transport line are very low. The worst case beam spill scenario is calculated to result in a personnel exposure of about 0.01 Gys/s (1 rad/s). Although the preferred solution is to increase the bulk shielding between the beam line and the experimental area, the physical dimensions of the site do not permit an adequate amount of shielding to be added. The solution adopted is a layered system of three types of highly reliable detector systems: a current limiter system located in the beam line, a neutron detector system located in the experimental areas, and an ion chamber system located on the walls of the beam line tunnels. The ion chamber system is capable of shutting off the beam in less than 0.5 s, resulting in a worst case personnel exposure of 0.005 Gys (0.5 rad). 4 figs

The activity concentrations of 222Rn and corresponding health risk in groundwater samples from basement and sandstone aquifer; the correlation to physicochemical parameters

International Nuclear Information System (INIS)

Abdurabu, Wedad Ali; Ramli, Ahmad Termizi; Saleh, Muneer Aziz; Heryansyah, Arien

2016-01-01

This study aims to evaluate the activity concentrations of 222 Rn and to assess the corresponding health risk in groundwater samples obtained in Juban District, Ad Dali’ Governorate, Yemen. The measurements were performed by RAD 7 radon detector manufactured by DURRIDGE COMPANY Inc. The activity concentrations of 222 Rn ranged from 1.0±0.2 Bq l −1 to 896.0±0.8 Bq l −1 . 57% of the groundwater samples were above the US Environmental Protection Agency (USEPA) recommended value for Rn in water. Induced coupled plasma mass spectrometry (ICP-MS) was used to determine the concentrations of uranium in groundwater samples. The measured concentration of U ranged from 0.33±0.01 μg l −1 to 24.6±0.6 μg l −1 . The results were comparable to internationally recommended values. The highest concentration of U and 222 Rn were found to be in the basement aquifer, while the lowest concentrations of both radionuclides were in the sandstone aquifer. High concentrations of Rn are found along fault zones. The relationship between the activity concentration of 222 Rn, concentration of U and physicochemical parameters were investigated. The results showed a very strong relationship between activity concentrations of 222 Rn with concentrations of U and the salinity of water. - Highlights: • The highest concentration of U and 222 Rn was found to be in the basement aquifer. • A 57% of the groundwater samples were above the USEPA recommended value. • Mean annual effective dose for ingestion was 24 times the world average. • Mean annual effective dose for inhalation was 23 times the world. • Strong relationship between 222 Rn with concentration of U in the basement aquifer.

Priit Pärn ja tema kool olid võidukad

Index Scriptorium Estoniae

2003-01-01

Eesti Joonisfilmi "Karl ja Marilyn" : stsenarist, režissöör, kunstnik, värvikunstnik ja monteerija Priit Pärn ja Kaspar Jancise "Weitzenbergi tänav" võitsid Inglismaal Norwichis rahvusvahelisel animafilmide festivalil vastavalt esikoha rahvusvahelises ja diplomi tudengifilmide kategoorias. Ottawa tudengifilmide festivalil sai parima animatsioonikooli tiitli Priit Pärna juhitud Turu Kunstiakadeemia animatsiooniosakond

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.

Environmental 222Rn as a background source in the solar neutrino experiment GALLEX

International Nuclear Information System (INIS)

Wojcik, M.

1996-01-01

The radiochemical neutrino experiment GALLEX is described. Its aim is to measure the flux of low energy solar neutrinos. In this experiment it is essential to suppress strongly the background of environmental origin, like charged cosmic rays, neutrons and gamma rays. In low-level radioactivity measurements performed in deep underground laboratory where flux of charged comic rays is strongly reduced, radon (Rn) exhaled from rock or concrete walls forms a most important strong, time-dependent background component. In this work the impact of Rn on the GALLEX experiment has been discussed and attempts to recognize and minimize its influence on the counter background were described. 63 refs, 22 figs, 11 tabs

Evaluation of a Po-210 bioassay as an index of the exposure of uranium mine workers in Japan to radon daughters

International Nuclear Information System (INIS)

Okabayashi, Hiroyuki; Suzuki, Masashi; Hongo, Shozo; Watanabe, Seiki.

1975-01-01

As an indicator nuclide for inhalation exposure of mine workders to Rn daughters in a Japanses uranium mine, 210 Po urinalyses of the workers and surveys of some environmental factors were conducted. An estimation study of concentrations of Rn daughters in a mine, indicated that about 800-50 pCi of 210 Po could have been accumulated in each miner's body. However, according to the results of urinalyses performed several times in 5 years, a statistical difference in the quantity of 210 Po in urine among miners and non-mining workers there was not clearly identified. Investigations of 210 Po concentrations in the mine's air, water, foods (of about 30 kinds) and cigarets, and investigations of feces-urine 210 Po ratios in humans revealed that these factors would greatly affect the metabolism and 210 Po excretion of the workers. In particular, some marine foods in Japan contained a great amount of 210 Po (several hundreds times that of other foods) and cigarets showed 0.3-0.8 pCi of 210 Po per gramme. Smokers definitely excreted more 210 Po in urine than non-smokers. Feces-urine ratios ranged between 5.2-42.9 in one human subject. Therefore, it can be concluded that 210 Po would not be a good indicator for human exposure to Rn daughters, unless great care is taken regarding the eating and smoking habits of mine workers, as well as the exposure conditions in the uranium mine. (Evans, J.)

Comparison of the quantulus 1220 and 300SL liquid scintillation counters for the analysis of {sup 222}Rn in groundwater

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyun Cheol; Jung, Yoon Hee; Lee, Wanno; Choi, Guen Sik; Chung, Kun Ho; Kang, Mun Ja [Environmental Radioactivity Assessment Team, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-12-15

Liquid scintillation counters (LSCs) are commonly used as an analytical method for detecting {sup 222}Rn in groundwater because they involve a simple sample pretreatment and allow high throughout with an autosampler. The Quantulus 1220 is the best-selling LSC in Korea, but its production was stopped. Recently, a new type of LSC, the 300SL, was introduced. In this study, the 300SL was compared with the Quantulus 1220 in order to evaluate the ability of each apparatus to detect {sup 222}Rn in groundwater. The Quantulus 1220 and 300SL were used to detect the presence of {sup 222}Rn. Radon gas was extracted from a groundwater sample using a water-immiscible cocktail in a LSC vial. The optimal analytical conditions for each LSC were determined using a {sup 222}Rn calibration source prepared with a {sup 226}Ra source. The optimal pulse shape analysis level for alpha and beta separation was 80 for the Quantulus 1220, and the corresponding pulse length index was 12 in the 300SL. The counting efficiency of the Quantulus 1220 for alpha emissions was similar to that of the 300SL, but the background count rate of the Quantulus 1220 was 10 times lower than that of the 300SL. The minimum detectable activity of the Quantulus 1220 was 0.08 Bq·L{sup -,} while that of the 300SL was 0.20 Bq·L{sup -1}. The analytical results regarding {sup 222}Rn in groundwater were less than 10% different between these LSCs. The 300SL is an LSC that is comparable to the Quantulus 1220 for detecting {sup 222}Rn in groundwater. Both LSCs can be applied to determine the levels of {sup 222}Rn in groundwater under the management of the Ministry of Environment.

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

Udsatte børn og unge i den inkluderende skole

DEFF Research Database (Denmark)

Hedegaard-Sørensen, Lotte; Grumløse, Sine Penthin

2017-01-01

Denne artikel belyser, hvordan undervisningen i folkeskolen – mod de bedste politiske og pædagogiske (forskning og læ-reruddannelse) hensigter om inkludering – ekskluderer en gruppe udsatte børn og unge. Artiklen bygger på et forsk-ningsprojekt om inklusion og differentiering, som har haft fokus ...

Study of natural radioactivity and 222Rn exhalation rate in soil samples for the assessment of average effective dose

International Nuclear Information System (INIS)

Bangotra, P.; Mehra, R.; Jakhu, R.; Sahoo, B.K

2016-01-01

The natural radioactivity in soil is usually determined from the 226 Ra (Radium), 232 Th (Thorium) and 40 K (potassium). 222 Rn and 220 Rn are produced in soil as a result of the presence of these radionuclides. As 226 Ra decay, the newly created 222 Rn radionuclide recoil from the parent grain and then exhale through the soil. Since 98.5% of radiological effects of 238 U series are produced by 226 Ra and its daughter products. The assessment of gamma radiation dose from natural sources is of particular importance as natural radiation is the largest contributor to the external dose of the world population. Authors are advised to maximize the information content utilizing the full space available. The main objective of the present study is to measure the level of natural radioactivity 226 Ra, 232 Th, 40 K and 222 Rn exhalation rate in the soil samples for health risk assessment

Accelerated second-degree nursing students: predictors of graduation and NCLEX-RN first-time pass rates.

Science.gov (United States)

Penprase, Barbara B; Harris, Margaret A

2013-01-01

It is important to understand and identify factors that affect students' academic performance before entry into a nursing program and as they progress through the program. The authors discuss a study, and its outcomes, that assessed accelerated second-degree nursing students' prenursing and core nursing grades that served to predict their success at completing the nursing program and passing NCLEX-RN on first attempt. Strategies were identified to help at-risk students to be successful in the program and with first-time passage of NCLEX-RN.

Two remarks on normality preserving Borel automorphisms of Rn

Indian Academy of Sciences (India)