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Sample records for background radiation area

  1. Study of Natural Background Radiation around Gurvanbulag Uranium Deposit Area

    Science.gov (United States)

    Enkhbat, N.; Norov, N.; Bat-Erdene, B.; Khuukhenkhuu, G.; Otgooloi, B.

    2009-03-01

    In this work, we will show the study of natural background radiation level around the Gurvanbulag (GB) uranium deposit area in the eastern part of Mongolia. We collected environmental soil samples from 102 points around GB Uranium deposit. Collected samples were measured by HPGe gamma spectrometer at Nuclear Research Center, National University of Mongolia. The averaged activity concentrations of Ra-226, Th-232, K-40, and Cs-137 were 37.1, 29, 939, and 17.7 Bq/kg, respectively.

  2. Radioactivity in the groundwater of a high background radiation area.

    Science.gov (United States)

    Shabana, E I; Kinsara, A A

    2014-11-01

    Natural radioactivity was measured in groundwater samples collected from 37 wells scattered in an inhabited area of high natural background radiation, in a purpose of radiation protection. The study area is adjacent to Aja heights of granitic composition in Hail province, Saudi Arabia. Initial screening for gross α and gross β activities showed levels exceeded the national regulation limits set out for gross α and gross β activities in drinking water. The gross α activity ranged from 0.17 to 5.41 Bq L(-)(1) with an average value of 2.15 Bq L(-)(1), whereas gross β activity ranged from 0.48 to 5.16 Bq L(-)(1), with an average value of 2.60 Bq L(-)(1). The detail analyses indicated that the groundwater of this province is contaminated with uranium and radium ((226)Ra and (228)Ra). The average activity concentrations of (238)U, (234)U, (226)Ra and (228)Ra were 0.40, 0.77, 0.29 and 0.46 Bq L(-)(1), respectively. The higher uranium content was found in the samples of granitic aquifers, whereas the higher radium content was found in the samples of sandstone aquifers. Based on the obtained results, mechanism of leaching of the predominant radionuclides has been discussed in detail.

  3. Radiation dose in the high background radiation area in Kerala, India.

    Science.gov (United States)

    Christa, E P; Jojo, P J; Vaidyan, V K; Anilkumar, S; Eappen, K P

    2012-03-01

    A systematic radiological survey has been carried out in the region of high-background radiation area in Kollam district of Kerala to define the natural gamma-radiation levels. One hundred and forty seven soil samples from high-background radiation areas and five samples from normal background region were collected as per standard sampling procedures and were analysed for (238)U, (232)Th and (40)K by gamma-ray spectroscopy. External gamma dose rates at all sampling locations were also measured using a survey meter. The activities of (238)U, (232)Th and (40)K was found to vary from 17 to 3081 Bq kg(-1), 54 to 11976 Bq kg(-1) and BDL (67.4 Bq kg(-1)) to 216 Bq kg(-1), respectively, in the study area. Such heterogeneous distribution of radionuclides in the region may be attributed to the deposition phenomenon of beach sand soil in the region. Radium equivalent activities were found high in several locations. External gamma dose rates estimated from the levels of radionuclides in soil had a range from 49 to 9244 nGy h(-1). The result of gamma dose rate measured at the sampling sites using survey meter showed an excellent correlation with dose rates computed from the natural radionuclides estimated from the soil samples. PMID:21515614

  4. Significance of epidemiological and cytogenetic studies on high background radiation area residents

    International Nuclear Information System (INIS)

    Some area in the world are known as background levels of radiation are 3-5 times higher than the world average. The studies in high background area (HBRA) residents provide important direct information on the biological and health effects of chronic low dose rate radiation. (author)

  5. Confounding factors in radiation epidemiology and their comparability between high background radiation areas and control areas in Yangjiang, China

    International Nuclear Information System (INIS)

    Objective: Confounding factors in radiation epidemiology and their comparability among the four different dose-rate groups in high background radiation areas were studied. Methods: The demography data were collected by a specific registration method. For the components of diet and life style, the samples were taken by a stratified random sampling method. Results: The sex-, age-distributions and the life expectancy of the members of a cohort 35 years old and above in the four dose-rate groups were similar to each other. The components of diet were constituted mostly of grains and vegetables with less meat, eggs and milk. The percentages of cigarette smokers were 27.7%-31.3% in both male and female subjects and the percentages of alcohol drinkers were 4.0%-6.9% in them. Conclusion: The results show that there is good comparability between the four dose-rate groups except for background radiation level, and it is suggested that the taken food consisting of grains and vegetables may be a beneficial factor leading to low incidence of malignancies in this area

  6. Epidemiological investigation of radiological effects in high background radiation areas of Yangjiang, China

    International Nuclear Information System (INIS)

    The purpose of this investigation is to provide some information for providing whether any detrimental effects exist in a large population whose families have been continuously exposed to a low dose rate radiation. Two areas in Yangjiang Country, characterized by high background radiation (HBR) with environmental gamma exposure, large population size and long-term inhabitants, were selected for evaluation of late effects of HBR. The areas with normal radiation background close to the Yangjiang Country were selected as control areas. Up to 1986 approximately one million person-years in each area in both HBR and control areas have been observed. No increase of cancer mortality was found in the HBR areas; on the contrary, cancer mortality tended to be lower in the HBR areas than the control areas. The prevalence of hereditary diseases and congenital defects was similar in both HBR and control areas, but the frequency of Down's syndrome was higher in the HBR areas (through within the normal range) than the control areas. A possible explanation is the difference of age of maternity between the HBR and control areas, and the extremely low frequency in the control areas. Possible factors influencing the incidence of mutationbased diseases were comparable in the HBR and control groups. However, the cultural and educational levels were somewhat different, probably affecting health status and family planning. It is likely that there may be a dose threshold for cancer incidence, but this remains to be determined by further research. (N.K.)

  7. Evaluation of High Level Environmental Background Radiation Areas and its Variation in Ramsar

    Directory of Open Access Journals (Sweden)

    Tayyeb Allahverdi Pourfallah

    2012-03-01

    Full Text Available Introduction The exposure of human beings to ionizing radiation from natural sources is a continuing and inescapable feature of life on earth. For most individuals, this exposure exceeds that from all man-made sources combined. Materials and Methods In this study, the annual effective dose in high level environmental background radiation areas (HLEBRAs of northern city of Ramsar in Iran was determined. For dosimetry, a gamma radiation dosimeter was used. Measurements were performed in more than 90 points in five districts with HLEBR around and near hot springs. Results In some areas, the annual effective dose from outdoor external gamma radiation in HLEBRAs (30 mSv/y exceeded the annual effective dose limit for radiation workers. Our results are evident that the population dose from normal background radiation in HLEBRAs is 200 times higher than corresponding values in Ramsar sea shore. To estimate the cosmic ray contribution, dose measurements were performed on the sea surface one km off the sea shore. Conclusion The observed differences over locations and measured doses between this study and the others revealed the dynamic nature of this phenomenon, and necessitate performing the periodic studies in these areas. Moreover, cytogenetic and immunologic researches for studying the long term effects of these high level environmental radiations on the residents of these HLEBRAs are necessary.

  8. A review of the studies on the high background radiation areas of the world

    International Nuclear Information System (INIS)

    The most important places among the well documented high background radiation areas (HBRA) of the world inhabited by sizable populations are : Guarapari (Brazil), Yangjiang (China), Chavara and Manavalakkurichy (India), and Ramsar (Iran). While the source of the high background radiation is monazite deposits in the first three cases, radium in soil/water and radon in air are the sources of high background radiation in Ramsar. In India, there are quite a few monazite placer deposits along its long coastal line: Ullal (Karnataka), Chavara (Kerala), Manavalakkurichy and Kalpakkam (Tamilnadu), and Chatrapur (Orissa). During the last three decades many investigations have been carried out in these areas covering various aspects such as radiation dosimetry, biological effects, ecological effects, epidemiology etc. Reports, often vague and inconclusive, continue to appear in literature on topics like genetic effects, cancer risk, hormesis, radon dose estimates etc. A summary of all the important results reported so far, as well as some thoughts on possible future programmes in these areas are presented. (author). 7 refs., 1 tab., 1 fig

  9. Profiles of comprehensive dose to population in the high background radiation area in Chhattrapur, Odisha, India

    International Nuclear Information System (INIS)

    A study of the profiles of radiation dose due to natural radioactivity to the populations inhabiting in the High Background Radiation Area (HBRA) of the monazite bearing region in Odisha has been carried out by radiation monitoring of twenty four villages in this region. Comprehensive effective dose was computed taking all the path routes of exposure into consideration; the average effective dose was 4.7±1.0 mSv/y which ranged between 1.4±0.2-6.3±1.3 mSv/y. The contributions of terrestrial radiation, inhalation of radon, thoron progenies and ingestion of food and water to the total dose was 51%, 28% and 13%, respectively. (author)

  10. Levels of thoron and progeny in high background radiation area of southeastern coast of Odisha, India.

    Science.gov (United States)

    Ramola, R C; Gusain, G S; Rautela, B S; Sagar, D V; Prasad, G; Shahoo, S K; Ishikawa, T; Omori, Y; Janik, M; Sorimachi, A; Tokonami, S

    2012-11-01

    Exposure to radon, (222)Rn, is assumed to be the most significant source of natural radiation to human beings in most cases. It is thought that radon and its progeny are major factors that cause cancer. The presence of thoron, (220)Rn, was often neglected because it was considered that the quantity of thoron in the environment is less than that of radon. However, recent studies have shown that a high thoron concentration was found in some regions and the exposure to (220)Rn and its progeny can equal or several time exceed that of (220)Rn and its progeny. The results of thoron and its progeny measurements in the houses of high background radiation area (HBRA) of the southeastern coast of Odisha, India presented here. This area is one of the high background radiation areas in India with a large deposit of monazite sand which is the probable source of thoron. Both active and passive methods were employed for the measurement of thoron and its progeny in cement, brick and mud houses in the study area. Thoron concentration was measured using RAD-7 and Raduet. A CR-39 track detector was employed for the measurement of environmental thoron progeny, both in active and passive modes. Thoron and its progeny concentrations were found to be comparatively high in the area. A comparison between the results obtained with various techniques is presented in this paper.

  11. A survey of senile dementia in the high background radiation areas in Yangjiang, China

    International Nuclear Information System (INIS)

    Objective: To evaluate the effects of long-term low dose and low dose-rate ionizing radiation exposure on the prevalence rate of senile dementia, further assess the effects of low-dose radiation exposure on central nervous system and study the pathogen of senile dementia, and provide direct observational data of human beings. Methods: A cross-sectional study of the prevalence of senile dementia was carried out in high background radiation areas in Yangjiang, Guangdong Province, China. The survey was conducted in two stages. For the initial screening, Hasegawa Dementia Scale (HDS) was used for all subjects. In the second stage, the stage of diagnosis, special questionnaires of healthy state of old people were sued. The final diagnoses were made according to the third revised edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM III-R) of American Psychiatric Association. Results: 1018 inhabitants aged 65 years and over, including 513 persons in HBRA and 505 in CA were observed. According to DSM III-R, 61 cases (31 cases in HBRA and 30 cases in CA) of senile dementia were diagnosed. The prevalence rates of senile dementia are 6.04% in HBRA and 5.94% in CA, the total prevalence rate being 5.99%. Conclusion: No significant statistical difference in the prevalence rate of senile dementia between the two areas was found, suggesting that the prevalence rate of senile dementia in these areas is not associated with the high background radiation exposure

  12. Public exposure due to external gamma background radiation in boundary areas of Iran.

    Science.gov (United States)

    Pooya, S M Hosseini; Dashtipour, M R; Enferadi, A; Orouji, T

    2015-09-01

    A monitoring program in boundary areas of a country is an appropriate way to indicate the level of public exposure. In this research, gamma background radiation was measured using TL dosimeters at 12 boundary areas as well as in the capital city of Iran during the period 2010 to 2011. The measurements were carried out in semi-annual time intervals from January to June and July to December in each year. The maximum average dose equivalent value measured was approximately 70 μSv/month for Tehran city. Also, the average dose values obtained were less than 40 μSv/month for all the cities located at the sea level except that of high level natural radiation area of Ramsar, and more than 55 μSv/month for the higher elevation cities. The public exposure due to ambient gamma dose equivalent in Iran is within the levels reported by UNSCEAR. PMID:26057985

  13. Radionuclides and Radiation Indices of High Background Radiation Area in Chavara-Neendakara Placer Deposits (Kerala, India)

    OpenAIRE

    Mary Thomas Derin; Perumal Vijayagopal; Balasubramaniam Venkatraman; Ramesh Chandra Chaubey; Anilkumar Gopinathan

    2012-01-01

    The present paper describes a detailed study on the distribution of radionuclides along Chavara - Neendakara placer deposit, a high background radiation area (HBRA) along the Southwest coast of India (Kerala). Judged from our studies using HPGe gamma spectrometric detector, it becomes evident that Uranium ((238)U), Thorium ((232)Th) and Potassium ((40)K) are the major sources for radioactivity prevailing in the area. Our statistical analyses reveal the existence of a high positive correlation...

  14. Measurement of radioactivity in an elevated radiation background area of Western Ghats

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    Manigandan P.K.

    2014-01-01

    Full Text Available As part of monitoring the exposure of the general public to natural radioactivity, the activity concentration of naturally occurring radionuclides in soil samples in an elevated radiation background area of Western Ghats was determined using gamma-ray spectrometry. Average values of the activity concentration of radionuclides, outdoor terrestrial gamma dose rate, annual effective dose equivalent and radiation hazard indices from soil activity were estimated. The activity concentrations of 232Th and average outdoor terrestrial gamma dose rate were found to be higher than the world average, possibly affecting the Western Ghats environment in general. Therefore, radiological risks to the general population from ionizing radiation from the naturally occurring radionuclides in the soil are considered to be significant. How- ever, other radiological hazard indices were found to be within permissible limits.

  15. Radon-thoron exposures in high background radiation areas: a review

    International Nuclear Information System (INIS)

    The radon-thoron measurements reported in literature for the high background radiation areas (HBRAs) of the world are summarised here. The most important areas covered are the Radon Spas and the thorium bearing monazite deposits. Special mention is made of the ongoing programmes of radon-thoron survey in the monazite beach areas of India; preliminary measurements indicate significant levels of thoron exposures. The diurnal and seasonal variations are quite wide underscoring the importance of carrying out integrated measurements for meaningful assessments of population exposures. Radon-thoron inhalation dose rates upto 30 mSv/y have been measured in lran as well as India. It has been generally observed that the cumulative population doses due to radon-thoron inhalation are as high as those due to the external exposures in these HBRAs. (author). 7 refs., 2 tabs., 3 figs

  16. The Natural Background Gamma Radiation Exposure in the Metropolitan Area of the Valley of Mexico.

    Science.gov (United States)

    Jones, Mary Feild

    Measurements of the natural background radiation have been made at numerous places throughout the world. Very little work in this field has been done in developing countries. In Mexico the natural radiation to which the population is exposed has not been assessed. This dissertation represents a pioneer study in this environmental area. The radiation exposure which occupants within buildings receive as a result of naturally occurring radionuclides present in construction materials is the principal focus. Data were collected between August 1979 and November 1980. Continuous monitoring was done with TLDs placed on site for periods of 3 to 6 months. The instrumentation used for "real-time" measurements was a portable NaI (Tl) scintillation detector. In addition, radiometric measurements were performed on construction materials commonly used in Mexican homes. Based on TLD readings taken within 75 dwellings, the typical indoor exposure for a resident of the study area is 9.2 (mu)Rh('-1). The average reading of the 152 indoor scintillometer surveys was 9.5 (mu)Rh('-1), the outdoor reading 7.5 (mu)Rh('-1). Results of one-way and multi-way analyses of the exposure data to determine the effect due to building materials type, geologic subsoil, age of dwelling, and elevation are also presented. The results of 152 indoor scintillometer surveys are described.

  17. Measurements of External Gamma Radiation in the Area of Low Natural Background

    International Nuclear Information System (INIS)

    The automatic radiation monitoring in Slovenia incorporates measurements of external gamma radiation, aerosol radioactivity, radon progeny monitoring and radioactive deposition. At the moment, 44 gamma measuring probes are distributed uniformly over the territory of Slovenia, belonging to different institutions and integrated in a common network administered by the SNSA. External gamma radiation is measured by the system of probes with two GM tubes operating at different radiation ranges. The measuring stations used are mostly supplied by the Slovenian manufacturer AMES, type MFM-202 (in further text referred to as MFM), and partially by the Finish company RADOS Technology Oy, type ALNOR RD-02L (in further text referred to as ALNOR). These probes are normally installed within an undisturbed area (grassland), fixed at a standard height of 1 m above the ground and connected via radio or telephone to local data gathering stations. Within the scope of automatic monitoring, the data thus collected are also analyzed, used for alarming, archived and prepared for on-line presentation on the Internet. The difference between ALNOR and MFM probes is shown to be constant even in the condition of low natural background. If we take into account previous measurements which were made in order to check instrument calibrations, one can conclude that the difference is a linear shift that can be either added to the ALNOR results or subtracted from the MFM results. It is supposed to be due to inherent instrument radioactivity and electronic noise. One manufacturer (ALNOR) chose to subtract this instrument background from the measured results, the other one (MFM) did not. (author)

  18. Background radiation in the Albuquerque, New Mexico, U.S.A., area

    International Nuclear Information System (INIS)

    Background radiation levels in the Albuquerque, New Mexico, area are elevated when compared to much of the US. Soil K, U, and Th are somewhat elevated compared to average values in this country and generate roughly 60 mrem per year to the average resident. Cosmic ray contribution, due to the mean elevation of 5,200 ft above sea level, is 80 mrem/yr-well over the average for the US. Thirty percent of the homes in Albuquerque contain indoor radon levels over the EPA action level of 4 pCi/l compared to 10-12% of homes for the entire US. Indoor radon contributes about 100-300 mrem/yr. Total contributions from other minor sources are under 10 mrem/yr. Thus total background radiation received by Albuquerque residents is about 330-530 mrem/yr, well in excess of the rest of the US. The spread in mrem values is due to variations in the contribution from indoor radon

  19. Radionuclides and radiation indices of high background radiation area in Chavara-Neendakara placer deposits (Kerala, India.

    Directory of Open Access Journals (Sweden)

    Mary Thomas Derin

    Full Text Available The present paper describes a detailed study on the distribution of radionuclides along Chavara - Neendakara placer deposit, a high background radiation area (HBRA along the Southwest coast of India (Kerala. Judged from our studies using HPGe gamma spectrometric detector, it becomes evident that Uranium ((238U, Thorium ((232Th and Potassium ((40K are the major sources for radioactivity prevailing in the area. Our statistical analyses reveal the existence of a high positive correlation between (238U and (232Th, implicating that the levels of these elements are interdependent. Our SEM-EDAX analyses reveal that titanium (Ti and zircon (Zr are the major trace elements in the sand samples, followed by aluminum, copper, iron, ruthenium, magnesium, calcium, sulphur and lead. This is first of its kind report on the radiation hazard indices on this placer deposit. The average absorbed dose rates (9795 nGy h(-1 computed from the present study is comparable with the top-ranking HBRAs in the world, thus offering the Chavara-Neendakara placer the second position, after Brazil; pertinently, this value is much higher than the World average. The perceptibly high absorbed gamma dose rates, entrained with the high annual external effective dose rates (AEED and average annual gonadal dose equivalent (AGDE values existing in this HBRA, encourage us to suggest for a candid assessment of the impact of the background radiation, if any, on the organisms that inhabit along this placer deposit. Future research could effectively address the issue of the possible impact of natural radiation on the biota inhabiting this HBRA.

  20. Case-control study of cancer deaths in high background radiation areas of China

    International Nuclear Information System (INIS)

    This paper presents the results of a case-control study of deaths from liver, stomach and lung cancers in the high background radiation areas (HBRA) in Yangjiang County and neighboring control areas (CA). The purpose of this study was to explore the probable relationship between the cancer deaths and the environmental mutation-related factors in the two areas, so that the role of elevated natural radiation in cancer mortality could be properly ascertained. The studied numbers of cases of liver, stomach and lung cancers were 64, 28 and 17 in HBRA, and 75, 36 and 13 in CA, respectively. The proportion of the number of cases to that of the controls was 1:1 for liver cancer and 1:2 for cancers of stomach and lung. The factors studied included pesticide, smoking, alcohol consumption, medical X-ray exposure, diet, and the socioeconomic status, such as occupation, education, economic income, living space etc. The data for this study were collected through interviewing. The data collected were analysed by methods of matched and unmatched studies. The results expressed by odds ratio (OR) show that there is no significant between most factors studied and cancer deaths, although the associations of desths from stomach cancer with drinking water of nonwell source and of lung cancer with alcohol consumption in HBRA, and the associations of liver cancer deaths with occupations involving poisonous and noxious substances, pesticide and alcohol, and of lung cancer with pesticide and lower family income in CA can be found. This study has provided some clues for explaining the difference in cancer mortalities between HBRA and CA

  1. Nutrition status in residents in the high background radiation area of Yangjiang, China

    International Nuclear Information System (INIS)

    Objective: To investigate the current status of nutrition and examine the difference between inhabitants in the high background radiation area (HBRA) and the control area (CA). Methods: Sixty and sixty-five male farmers aged 50 and over were randomly selected from HBRA and CA, respectively. Information on dwelling history, history of disease, medical treatment and X-ray examination were collected by interview. Body height and weight were measured, and BMIs were calculated. Serum levels of total protein, albumin and globulin, triacylglycerol (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low- density lipoprotein cholesterol (LDL-C), Apo A1 and Apo B were measured. Results: There was difference in BMI distribution between the two groups. Averages of total biochemistry indexes measured were in normal range in the two groups. With adjustment to age distribution, the serum levels of total protein, albumin and triacylglycerol (TG) of residents in CA were higher than those in HBRA; high-density lipoprotein cholesterol level was higher in HBRA than that in CA. Conclusions: This serum assay of nutrients in HBRA and CA residents confirmed the results obtained from previous surveys. Both HBRA and CA residents have similar nutrition status, residents in CA consumed more animal protein and fat compared with those in HBRA. (authors)

  2. Background radiation and individual dosimetry in the costal area of Tamil Nadu, India.

    Science.gov (United States)

    Matsuda, Naoki; Brahmanandhan, G M; Yoshida, Masahiro; Takamura, Noboru; Suyama, Akihiko; Koguchi, Yasuhiro; Juto, Norimichi; Raj, Y Lenin; Winsley, Godwin; Selvasekarapandian, S

    2011-07-01

    South coast of India is known as the high-level background radiation area (HBRA) mainly due to beach sands that contain natural radionuclides as components of the mineral monazite. The rich deposit of monazite is unevenly distributed along the coastal belt of Tamil Nadu and Kerala. An HBRA site that laid in 2×7 m along the sea was found in the beach of Chinnavillai, Tamil Nadu, where the maximum ambient dose equivalent reached as high as 162.7 mSv y(-1). From the sands collected at the HBRA spot, the high-purity germanium semi-conductor detector identified six nuclides of thorium series, four nuclides of uranium series and two nuclides belonging to actinium series. The highest radioactivity observed was 43.7 Bq g(-1) of Th-228. The individual dose of five inhabitants in Chinnavillai, as measured by the radiophotoluminescence glass dosimetry system, demonstrated the average dose of 7.17 mSv y(-1) ranging from 2.79 to 14.17 mSv y(-1).

  3. Concentrations of radionuclides in cassava growing in high background radiation area and their transfer

    International Nuclear Information System (INIS)

    The concentrations of several natural radionuclides in common cassava (Manihot esculenta Crantz) growing in Yangjiang County, a high background radiation area in Guangdong Province, and their uptake from soil and distribution in the plant were investigated. The results show that the concentrations of natural uranium and thorium in cassava root are of the order of 10-6 g/kg, and those of radium-226, radium-228, lead-210 and polonium-210 are of the order of 10-11 Ci/kg. The highest level is 9.30 +- 0.30 x 10-11 Ci/kg (lead-210), and the lowest is 3.99 +- 0.20 x 10-11 Ci/kg (radium-226). The levels of natural uranium, thorium, radium-226 and polonium-210 in cassava are below the limits stipulated by the regulations for food hygiene in China, while the lead-210 level approaches the limit. It is noticeable that the highest level of radium-228 is 7.28 +- 1.03 x 10-11 Ci/kg, 10.4 times higher than the limit. The transfer of all he nuclides from soil to different parts of cassava shows a pattern contrary to that of he nuclides in the other regions where uranium-and radium-containing waste water and phosphate fertilizer are used in agriculture

  4. Effective doses of background radiation in the Almaty and the Kazakhstan nuclear sites areas

    International Nuclear Information System (INIS)

    The comparative results for determination of partial effective doses from each kind of ionizing radiation and all pathways of radionuclides intakes of Almaty city population, and localities adjoining to nuclear test sites (Lira and Azgir), as well as Semipalatinsk test site (STS). Results of effective dose calculations are evidencing about absence of considerable influence of tests on the sites on the natural radiation dose loads and about some exceeding of effective dose in Almaty above effective doses in the sites' areas. Artificial radionuclides contribution of the sites areas (beside STS) does not exceeds the level of global fallout in Almaty

  5. RADIU-226 CONTENT IN SOIL OF THE HIGH NATURAL BACKGROUND RADIATION AREA OF RAMSAR (IRAN

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    B.Khademi

    1978-11-01

    Full Text Available The existence of a high natural radiation area in the northern part of Iran (Ramsar is proved. Ra 226 in soil is measured. The results are: minimum 23.5 pCi/g and maximum 999 pCi/g soil. Environmental radioactivity is from 0.1 to 5 mr/h.

  6. Local microwave background radiation

    OpenAIRE

    Soares, Domingos

    2006-01-01

    An inquiry on a possible local origin for the Microwave Background Radiation is made. Thermal MBR photons are contained in a system called {\\it magnetic bottle} which is due to Earth magnetic field and solar wind particles, mostly electrons. Observational tests are anticipated.

  7. Environmental gamma monitoring in high background radiation areas of Orissa using CaSO4:Dy TL dosimeters

    International Nuclear Information System (INIS)

    Naturally occurring radionuclides are the major contributor to the total effective dose of ionizing radiation received by the population. In India, there are quite a few monazite sand bearing placer deposits causing high background radiation along its long coastline. Chatrapur, Orissa is one of the high background areas of India. The beach sand of this area contains natural mineral Monazite abundantly. Maximum and minimum dose were found 1202. 1 μGy in spring and 483.8 μGy in monsoon at Port School and Gopalpur respectively. In spring, summer, monsoon and winter season the dose ranges were observed 1202.1-520.3, 1154.7-503.6, 1066.3-483.8 and 1141.7-508.5 μG respectively. (author)

  8. High background radiation areas of Ram sar in Iran: evaluation of DNA damage by alkaline single cell gel electrophoresis (SCE)

    Energy Technology Data Exchange (ETDEWEB)

    Masoomi, J.R. [Biophysics Department, College of Sciences, Tarbiat Modarres University, Tehran (Iran, Islamic Republic of); Mohammadi, Sh. [Radiation Molecular Genetic Laboratory, National Radiation Protection Department (NRPD), Iranian Nuclear Regulatory Authority (INRA), P.O. Box 14155-4494, Tehran (Iran, Islamic Republic of); Amini, M. [Faculty of Pharmacy, Azad University of Tehran (Iran, Islamic Republic of); Ghiassi-Nejad, M. [Biophysics Department, College of Sciences, Tarbiat Modarres University, Tehran (Iran, Islamic Republic of)]. E-mail: ghiassi@mailcity.com

    2006-07-01

    The hot springs in special areas in Ram sar, a northern coastal town in Iran, contain {sup 226}Ra and {sup 222}Rn. The natural radiation effects, radiosensitivity or adaptive responses, on the inhabitants of high natural radiation in Ram sar were studied. The single cell gel electrophoresis was used to monitor DNA damages. Three groups of volunteers were selected, one from high natural background radiation areas as the case group and two from normal background radiation areas as controls (control 1 and control 2). The latter one had the similar living situation to case group while the other (control 2) had different living situation from the other groups. Peripheral blood mononuclear cells (PMNCs) were separated and irradiated by {sup 6}Co source at five different gamma doses. It was found that the spontaneous level of DNA damage and the induced DNA damage in all challenging doses in case group was considerably higher than control groups (p < 0.05). On the other hand, the repair rate in those volunteers, who received less than 10.2 mSv/y was significantly more than the control groups. In the contrary, individuals who live in homes with more than 10.2 mSv/y had incomplete repair. Additionally the plasma and urinary levels of vitamin C were measured spectrophotometrically. Although the concentration of vitamin C of plasma was equal in case and control 1 groups, the urinary level of vitamin C was found to be lower in the case group.

  9. The Very High Background Radiation Area in Ramsar, Iran: Public Health Risk or Signal for a Regulatory Paradigm Shift?

    Energy Technology Data Exchange (ETDEWEB)

    Karam, P. Andrew [Univ. of Rochester, Rochester, NY (United States); Mortazavi, S.M. Javad [Rafsanjan Univ. of Medical Sciences (Iran, Islamic Republic of). Medical Physics Dept.

    2001-07-01

    Ramsar, a city on the Caspian Sea in northern Iran hosts the highest measured natural background radiation levels in the world. These are due to the local geology and hydrogeology and, in some places, deliver radiation doses far in excess of those recommended for radiation workers. A population of about 2000 is exposed to average annual radiation levels of 10.2 mGy/yr and the highest recorded doses are about 260 mGy/yr. These high radiation levels are due to the deposition of {sup 226}Ra in local rocks and, because these rocks are used in the construction of many local houses, interior radiation levels are often similar to those found outside. The presence of areas such as Ramsar raises an interesting public health policy question: Is it necessary to relocate the inhabitants to areas of lower natural background radiation levels in the interests of public health? According to the linear, no-threshold (LNT) hypothesis, there is no doubt that relocating the population of Ramsar will result in a reduction in cancer incidence. Therefore, under any reasonable policy based on the LNT hypothesis, the public health is best served by relocating many of Ramsar's inhabitants to other areas along the Caspian Sea. At present, there is no reliable epidemiological data on cancer incidence among the inhabitants of Ramsar's high background radiation areas (HBRAs), but local physicians feel that local cancer incidence rates are lower than in neighboring cities. Furthermore, preliminary results indicate that there is a statistically significant radio adaptation in the inhabitants of Ramsar. Interestingly, it seems that the frequency of chromosome aberrations in the lymphocytes of the inhabitants of Ramsar is no higher than the control areas. This important finding suggests that the cancer rate in Ramsar should be no higher than in other comparable parts of Iran. In other HBRAs such as Yangjiang, China it has been reported that mortality from all cancers and those from

  10. The Very High Background Radiation Area in Ramsar, Iran: Public Health Risk or Signal for a Regulatory Paradigm Shift?

    International Nuclear Information System (INIS)

    Ramsar, a city on the Caspian Sea in northern Iran hosts the highest measured natural background radiation levels in the world. These are due to the local geology and hydrogeology and, in some places, deliver radiation doses far in excess of those recommended for radiation workers. A population of about 2000 is exposed to average annual radiation levels of 10.2 mGy/yr and the highest recorded doses are about 260 mGy/yr. These high radiation levels are due to the deposition of 226Ra in local rocks and, because these rocks are used in the construction of many local houses, interior radiation levels are often similar to those found outside. The presence of areas such as Ramsar raises an interesting public health policy question: Is it necessary to relocate the inhabitants to areas of lower natural background radiation levels in the interests of public health? According to the linear, no-threshold (LNT) hypothesis, there is no doubt that relocating the population of Ramsar will result in a reduction in cancer incidence. Therefore, under any reasonable policy based on the LNT hypothesis, the public health is best served by relocating many of Ramsar's inhabitants to other areas along the Caspian Sea. At present, there is no reliable epidemiological data on cancer incidence among the inhabitants of Ramsar's high background radiation areas (HBRAs), but local physicians feel that local cancer incidence rates are lower than in neighboring cities. Furthermore, preliminary results indicate that there is a statistically significant radio adaptation in the inhabitants of Ramsar. Interestingly, it seems that the frequency of chromosome aberrations in the lymphocytes of the inhabitants of Ramsar is no higher than the control areas. This important finding suggests that the cancer rate in Ramsar should be no higher than in other comparable parts of Iran. In other HBRAs such as Yangjiang, China it has been reported that mortality from all cancers and those from leukemia, breast and

  11. Excess cancer risk among inhabitants in the high background radiation area of Yangjiang, China (1979-1998)

    International Nuclear Information System (INIS)

    The mortality among the inhabitants in the high background radiation area (HBRA) of Yangjiang, Guangdong Province, China was first reported internationally in 1980. Most of the inhabitants lived in the study areas for six or more generations. External radiation dose from the natural sources, including thorium, was estimated to be 2.10 mSv/a in the HBRA and 0.77 mSv/a in the control area (CA). Regarding internal radiation exposure, it was estimated that internal radiation doses in the HBRA and the CA were 4.27 mSv/a and 1.65 mSv/a, respectively. The epidemiological studies had failed to show any excess risk of cancer. The major purpose of the present study is to evaluate the effects of continuous low dose-rate exposure to low-linear energy transfer (LET) ionizing radiation on excess cancer risk. In this report, we present the results of cancer mortality analysis during the period 1979-1998, adding 3 years to the previous reports. (author)

  12. Chromosome aberration, cancer mortality and hormetic phenomena among inhabitants in areas of high background radiation in China

    Energy Technology Data Exchange (ETDEWEB)

    Deqing, Chen; Luxin, Wei (High Background Radiation Research Group, Beijing (China))

    1991-12-01

    The respective average annual doses are about 330 and 110 mR/yr, in the high background radiation areas (HBRA) in Yangjiang County and the control areas (CA) in Enping and Taishan Counties. Both the HBRA and CA are in Guangdong Province which borders the South China Sea. The frequencies of chromosome aberration in circulating lymphocytes were examined for persons residing in the HBRA and CA. Those in the HBRA had increased frequencies of detectable abnormalities in stable aberrations (translocations and inversions) and unstable aberrations (dicentrics and rings). Previous reports have shown that when samples of circulating lymphocytes taken from inhabitants were tested in vitro for mitotic responses to phytohemagglutinin (PHA) and for the degree of unscheduled DNA synthesis (UDS) induced by UV-irradiation, there were higher responsiveness and UDS rates for those in the HBRA than in the CA. In contrast, mortality from all cancers and those from leukemia, breast and lung cancers that are inducible by radiation was not higher in the HBRA. Although the differences in the cancer mortality rates for the HBRA and CA are not significant, the findings are compatible with the assumption that the lower mortality from cancer in the HBRA is the result of the hormetic effects of the three-fold higher dose rate of background radiation in that areas. This assumption requires further study. (author).

  13. Survey of Gamma Dose and Radon Exhalation Rate from Soil Surface of High Background Natural Radiation Areas in Ramsar, Iran

    Directory of Open Access Journals (Sweden)

    Rouhollah Dehghani

    2013-09-01

    Full Text Available Background: Radon is a radioactive gas and the second leading cause of death due to lung cancer after smoking. Ramsar is known for having the highest levels of natural background radiation on earth. Materials and Methods: In this research study, 50 stations of high radioactivity areas of Ramsar were selected in warm season of the year. Then gamma dose and radon exhalation rate were measured.Results: Results showed that gamma dose and radon exhalation rate were in the range of 51-7100 nSv/hr and 9-15370 mBq/m2s, respectively.Conclusion: Compare to the worldwide average 16 mBq/m2s, estimated average annual effective of Radon exhalation rate in the study area is too high.

  14. Assessment of indoor radiation dose received by the residents of natural high background radiation areas of coastal villages of Kanyakumari district, Tamil Nadu, India

    International Nuclear Information System (INIS)

    Radiation exposure and effective dose received through two routes of exposure, viz. external and internal, via inhalation, by residents of 10 villages belonging to Natural High Background Radiation Areas (NHBRA) of coastal regions of Kanyakumari District and Tamil Nadu in India were studied. While the indoor gamma radiation levels were monitored using Thermo Luminescent Dosimeters (TLDs), the indoor radon and thoron gas concentrations were measured using twin chamber dosimeters employing Solid State Nuclear Track Detectors (SSNTDs, LR-115-II). The average total annual effective dose was estimated and found to be varying from 2.59 to 8.76 mSv. -- Highlights: → The effective dose received by the villages of Natural High Background Area (NHBRA) such as Enayam, Midalam and Mel Midalam is high when compared with other study areas. → The high dose indicates higher concentration of radioactive nuclides like Thorium and Uranium in the soil. → As radiation is harmful to human life, the external and internal doses can be reduced by removing the monazite content present in the soil by mineral separation. → Contribution from vegetables, fruits, fish and other non vegetarian items are also being examined. → These results along with other socio-economic factors can throw considerable light on the epidemiological impacts due to low levels of chronic exposure.

  15. Assessment of indoor radiation dose received by the residents of natural high background radiation areas of coastal villages of Kanyakumari district, Tamil Nadu, India

    Energy Technology Data Exchange (ETDEWEB)

    Deva Jayanthi, D., E-mail: d.devajayanthi@gmail.co [Department of Physics, Women' s Christian College, Nagercoil 629001 (India); Maniyan, C.G. [Environmental Assessment Division, BARC, Mumbai 400085 (India); Perumal, S. [Department of Physics and Research Centre, S.T.Hindu College, Nagercoil 629002 (India)

    2011-07-15

    Radiation exposure and effective dose received through two routes of exposure, viz. external and internal, via inhalation, by residents of 10 villages belonging to Natural High Background Radiation Areas (NHBRA) of coastal regions of Kanyakumari District and Tamil Nadu in India were studied. While the indoor gamma radiation levels were monitored using Thermo Luminescent Dosimeters (TLDs), the indoor radon and thoron gas concentrations were measured using twin chamber dosimeters employing Solid State Nuclear Track Detectors (SSNTDs, LR-115-II). The average total annual effective dose was estimated and found to be varying from 2.59 to 8.76 mSv. -- Highlights: {yields} The effective dose received by the villages of Natural High Background Area (NHBRA) such as Enayam, Midalam and Mel Midalam is high when compared with other study areas. {yields} The high dose indicates higher concentration of radioactive nuclides like Thorium and Uranium in the soil. {yields} As radiation is harmful to human life, the external and internal doses can be reduced by removing the monazite content present in the soil by mineral separation. {yields} Contribution from vegetables, fruits, fish and other non vegetarian items are also being examined. {yields} These results along with other socio-economic factors can throw considerable light on the epidemiological impacts due to low levels of chronic exposure.

  16. A case-control study of nasopharyngeal carcinoma among inhabitants in high background radiation areas of Yangjiang, China

    International Nuclear Information System (INIS)

    Objective: The purpose of the study was to confirm and explore main risk factors of nasopharyngeal carcinoma (NPC) in cohort members of the investigated areas, and evaluate effects of confounding factors on cancer risk associated with exposure to high background radiation. Methods: The deceased cases of NPC during the period of 1987-1995 were selected as study subjects for each of whom two controls were randomly selected from potential control subjects who died from causes other than malignant tumors and external causes, and matched for sex and years of birth and death (within 5 years). Using structure questionnaire, the relevant information including socioeconomic status, dietary habits, smoking and alcohol consumption, history of illness, agricultural use of pesticide, medical X-ray exposure and familial history of NPC were collected. The odds ratio (OR) was used as a measure of association between NPC and the risk factors. Results: 102 cases and 202 controls were successfully investigated. Single factor conditional logistic regression analysis showed that the occurrence of NPC was closely positively associated with intake of salted fish, pickles, fermented soybeans, cured meats, history of chronic rhinitis and familial history of NPC. Further multiple conditional logistic regression analysis turned out that intake of salted fish, history of chronic rhinits and familial history of NPC were the independent risk factors of NPC. After controlling for history of chronic rhinits and familial history of NPC, the results based on multiple conditional logistic regression analysis from high background radiation, intake of salted fish and fermented soybeans, tobacco smoking and alcohol consumption showed that only intake of salted fish was a significant risk factor (OR = 2.8, 95% CI 1.52-5.18), tobacco smoking (OR = 1.2, 95% CI 0.65-2.22), alcohol consumption (OR = 0.83, 95% CI 0.38-1.78) and exposure to high background radiation (OR= 0.86, 95% CI 0.44-1.68) did not

  17. Differential proteome analysis of a selected bacterial strain isolated from a high background radiation area in response to radium stress.

    Science.gov (United States)

    Zakeri, Farideh; Sadeghizadeh, Majid; Kardan, Mohammad Reza; Shahbani Zahiri, Hossein; Ahmadian, Gholamreza; Masoumi, Fatemeh; Sharafi, Hakimeh; Rigi, Garshasb; Vali, Hojatollah; Akbari Noghabi, Kambiz

    2012-08-01

    The present study describes the response of a bacterial strain, isolated from a hot spring in an area with the highest levels of natural radiation, under radium ((226)Ra) stress. The bacterium has been characterized as a novel and efficient radium biosorbent and identified as a variant of Serratia marcescens by biochemical tests and molecular recognition. In order to gain insights into key cellular events that allow this strain to survive and undergo (226)Ra adaptation and biosorption, the strain was tested under two experimental conditions of 1000 and 6000 Bq (226)Ra stress. A proteomic approach involving two-dimensional polyacrylamide gel electrophoresis and mass spectrometry was used to identify the differentially expressed proteins under (226)Ra stress. Functional assessment of identified proteins with significantly altered expression levels revealed several mechanisms thought to be involved in (226)Ra adaptation and conferring resistant phenotype to the isolate, including general stress adaptation, anti-oxidative stress, protein and nucleic acid synthesis, energy metabolism, efflux and transport proteins. It suggests that this strain through evolution is particularly well adapted to the high background radiation environment and could represent an alternative source to remove (226)Ra from such areas as well as industrial radionuclide polluted wastewaters.

  18. A case-control study of nasopharyngeal carcinoma in the high background radiation areas of Yangjiang, China

    International Nuclear Information System (INIS)

    The main purposes of this study were to identify the major determinants of nasopharyngeal carcinoma (NPC) in the high-background radiation areas (HBRA) in Yangjiang, China and to evaluate their potential confounding effects on the NPC risk associated with exposure to high background radiation. A matched case-control study was conducted using those who died of NPC during the period 1987-1995. Two controls were randomly selected for each case from those who died from causes other than malignancies and external causes. Cases and their controls were matched with respect to sex and the years of birth and death (±5 years). Study subjects' next-of-kin were interviewed using a standardized questionnaire to collect information on socioeconomic status, dietary habits, tobacco smoking and alcohol consumption, disease history, pesticide use, medical X-ray exposure, the family history of NPC and so on. We succeeded in interviewing 97 cases and 192 controls. Univariate conditional logistic regression analysis showed that NPC risk was associated with the consumption of salted fish, homemade pickles, and fermented soy beans, education levels, the history of chronic rhinitis, and the family history of NPC. Multivariate conditional logistic regression analysis revealed that education levels (Odds ratio (OR) for middle school or higher levels vs. no school education=3.8, 95% CI=1.2 to 11.8), salted fish intake (OR=3.2, 95% CI=1.7 to 6.1), the history of chronic rhinitis (OR=3.6, 95% CI=1.3 to 10.1), and the family history of NPC (OR=14.2, 95% CI=2.7 to 73.4) were independent risk factors of NPC. Tobacco smoking (OR=1.2, 95% CI=0.7 to 2.1), and alcohol consumption (OR=0.9, 95% CI=0.5 to 1.9) were not significantly related to NPC risk. The ORs of NPC risk comparing HBRA and a nearby control area before and after adjustment for the major risk determinants identified in the present study were 0.86 (95% CI=0.50 to 1.50) and 0.87 (95% CI=0.45 to 1.67), respectively. Salted fish intake was

  19. A case-control study of nasopharyngeal carcinoma in the high background radiation areas of Yangjiang, China

    Energy Technology Data Exchange (ETDEWEB)

    Zou Jianming; Zha Yongru [Guangdong Inst. of Prevention and Treatment of Occupational Diseases, Guangzhou (China); Sun Quanfu; Akiba, Suminori; Yuan Yongling; Tao Zufan; Wei Luxin; Sugahara, Tsutomu

    2000-10-01

    The main purposes of this study were to identify the major determinants of nasopharyngeal carcinoma (NPC) in the high-background radiation areas (HBRA) in Yangjiang, China and to evaluate their potential confounding effects on the NPC risk associated with exposure to high background radiation. A matched case-control study was conducted using those who died of NPC during the period 1987-1995. Two controls were randomly selected for each case from those who died from causes other than malignancies and external causes. Cases and their controls were matched with respect to sex and the years of birth and death ({+-}5 years). Study subjects' next-of-kin were interviewed using a standardized questionnaire to collect information on socioeconomic status, dietary habits, tobacco smoking and alcohol consumption, disease history, pesticide use, medical X-ray exposure, the family history of NPC and so on. We succeeded in interviewing 97 cases and 192 controls. Univariate conditional logistic regression analysis showed that NPC risk was associated with the consumption of salted fish, homemade pickles, and fermented soy beans, education levels, the history of chronic rhinitis, and the family history of NPC. Multivariate conditional logistic regression analysis revealed that education levels (Odds ratio (OR) for middle school or higher levels vs. no school education=3.8, 95% CI=1.2 to 11.8), salted fish intake (OR=3.2, 95% CI=1.7 to 6.1), the history of chronic rhinitis (OR=3.6, 95% CI=1.3 to 10.1), and the family history of NPC (OR=14.2, 95% CI=2.7 to 73.4) were independent risk factors of NPC. Tobacco smoking (OR=1.2, 95% CI=0.7 to 2.1), and alcohol consumption (OR=0.9, 95% CI=0.5 to 1.9) were not significantly related to NPC risk. The ORs of NPC risk comparing HBRA and a nearby control area before and after adjustment for the major risk determinants identified in the present study were 0.86 (95% CI=0.50 to 1.50) and 0.87 (95% CI=0.45 to 1.67), respectively. Salted fish

  20. Cancer mortality in the high background radiation areas of Yangjiang, China during the period between 1979 and 1995

    Energy Technology Data Exchange (ETDEWEB)

    Tao Zufan [Ministry of Health, Beijing (China). Lab. of Industrial Hygiene; Zha Yongru; Akiba, Suminori (and others)

    2000-10-01

    The objective of the present study was to estimate cancer risk associated with the low-level radiation exposure of an average annual effective dose of 6.4 mSv (including internal exposure) in the high background-radiation areas (HBRA) in Yangjiang, China. The mortality survey consisted of two steps, i.e., the follow-up of cohort members and the ascertainment of causes of death. The cohort members in HBRA were divided into three dose-groups on the basis of environmental dose-rates per year. The mortality experiences of those three dose groups were compared with those in the residents of control areas by means of relative risk (RR). During the period 1987-1995, we observed 926,226 person-years by following up 106,517 subjects in the cohort study, and accumulated 5,161 deaths, among which 557 were from cancers. We did not observe an increase in cancer mortality in HBRA (RR=0.96, 96% CI, 0.80 to 1.15). The combined data for the period 1979-95 included 125,079 subjects and accumulated 1,698,316 person-years, observed 10,415 total deaths and 1,003 cancer deaths. The relative risk of all cancers for whole HBRA as compared with the control area was estimated to be 0.99 (95% CI, 0.87 to 1.14). The relative risks of cancers of the stomach, colon, liver, lung, bone, female breast and thyroid within whole HBRA were less than one, while the risks for leukemia, cancers of the nasopharynx, esophagus, rectum, pancreas, skin, cervix uteri, brain and central nervous system, and malignant lymphoma were larger than one. None of them were significantly different from RR=1. Neither homogeneity tests nor trend tests revealed any statistically significant relationship between cancer risk and radiation dose. We did not find any increased cancer risk associated with the high levels of natural radiation in HBRA. On the contrary, the mortality of all cancers in HBRA was generally lower than that in the control area, but not statistically significant. (author)

  1. Dietary intake of naturally occurring radionuclides from thorium series, uranium series and potassium-40 in high background radiation areas of Manavalakurichi, Tamil Nadu

    International Nuclear Information System (INIS)

    Natural background radiation is a major source of human exposure to radiation. The source of background radiation is due to monazite containing naturally occurring radionuclides like thorium and uranium. These natural radionuclides are found in all environmental matrices like rocks, soil, water, and dietary sources. The intake of natural radionuclides to public would occur in ingestion pathway via dietary sources. The present study aims to evaluate the natural radionuclides in dietary sources from Manavalakurichi region, which is a High Background Radiation Area's (HBRA's) in Tamil Nadu. The natural radionuclides such as Uranium (238U and 234U), Radium (226Ra and 228Ra), Polonium (210Po) and Potassium (40K) in the dietary products were analyzed in various dietary sources and computed the ingestion dose for different age group of public residing in and around Manavalakurichi. The study can act as existing data for Indian population living in the high radiation background areas

  2. Imperceptible effect of radiation based on stable type chromosome aberrations accumulated in the lymphocytes of residents in the high background radiation area in China

    International Nuclear Information System (INIS)

    Cytogenetic investigation of stable type aberrations (translocations) was performed with our improved methods in 6 children and 15 elderly persons in a high background radiation area (HBRA) in China, and in 8 children and 11 elderly persons in a control area. The total numbers of cells analyzed in elderly persons were 68,297 in HBRA and 35,378 in controls and in children were 45,535 in HBRA and 56,198 in controls. On average 5138 cells per subject were analyzed. The variation in the frequencies of translocations per 1000 cells was small in children while it was large in elderly persons. No significant difference was found in the frequencies between HBRA and control (P>0.05, Mann-Whitney U test). On the other hand, correlation between age and translocation frequencies was significant at the 1% level (rs=0.658 with 37DF, Spearman rank correlation test). The contribution of an elevated level of natural radiation in HBRA in China to the induction of stable type chromosome aberrations does not have a significant effect compared with the contribution of chemical mutagens and/or metabolic factors. The present study suggests that the probability of the risk of causing malignant and/or congenital diseases by the increased amount of radiation is imperceptible in HBRA where the level of natural radiation is 3 to 5 times higher than that in the control area. (author)

  3. Ultraviolet Background Radiation

    Science.gov (United States)

    Henry, R. C.; Murthy, J.

    1993-12-01

    The UVX experiment was carried on the Space Shuttle Columbia between 1986 January 12 and 19 (STS-61C). Several ultraviolet spectrometers were used to obtain measurements of the diffuse ultraviolet background at 8 locations in the sky. We have reanalysed the UVX measurements of the surface brightness of the diffuse ultraviolet background above b = 40 using the dust-scattering model of Onaka & Kodaira (1991), which explicitly takes into account the variation of the source function with galactic longitude. The range of allowed values of interstellar grain albedoJa, and scattering asymmetry parameter g, is considerably expanded over those of a previous analysis. The new chi square probability contours come close to, but do not include, the values of a and g found for the interstellar grains by Witt et al. (1992) using the Ultraviolet Imaging Telescope (UIT) on the Astro mission. If we hypothesize in additon to the dust-scattered light an extragalactic component, of 300 1 100 photons cm-2 s-1 sr-1 A-1, attenuated by a cosecant b law, the new reduction of the UVX data gives complete consistency with the Witt et al. determination of the optical parameters of the grains in the ultraviolet. This work was supported by United States Air Force Contract F19628-93-K-0004, and by National Aeronautics and Space Administration grant NASA NAG5-619. We are grateful for the encouragement of Dr. Stephan Price, and we thank Dr. L. Danly for information. Onaka, T., & Kodaira, K. 1991, ApJ, 379, 532 Witt, A. N., Petersohn, J. K., Bohlin, R. C., O'Connell, R. W., Roberts, M. S., Smith, A. M., & Stecher, T. P. 1992, ApJ, 395, L5

  4. Establishment of immortalized B lymphoblastoid cell lines of old residents in high background radiation area in Guangdong, China

    International Nuclear Information System (INIS)

    Objective: To establish the immortalized cell lines of peripheral blood lymphocytes for old male residents in high background radiation area (HBRA) in Guangdong, China, in order to preserve the specific genomic resources of residents in HBRA for the further genetic and molecular biological study on HBRA. Methods: The peripheral blood samples of 20 old male residents in HBRA were collected after informed consent. The immortalized B lymphoblastoid cell lines, 2 fox each resident, were established with Epstein-Barr virus. After being frozen and recovered, the cell viability, the contamination of bacterium and mycoplasma were analyzed. The stabilization of cell lines was decided by comparing the karyotypes of the peripheral blood lymphocytes and the cell lines. Results: 40 cell lines for 20 residents in HBRA were successfully established.. The recovery rate of cell lines after being frozen was 100% . All the cell viablity after recovery was higher than 90%, and no contamination of bacteria and mycoplasma occurred. The karyotypes of the 20th generation cell lines were not change. Conclusion: The immortalized cell lines established in this study could provide biological resources for further study on genetics and molecular biology in HBRA. (authors)

  5. Radiation background of Black Sea coastal environment

    International Nuclear Information System (INIS)

    The main objective of the project is to establish the level of radiation background and its sources in the Black Sea coastal environment. Marine samples will be collected in the Black Sea Coast area. The content of different radionuclides will be analyzed and the results will be used in a GIS application. The gamma emitting radionuclides will be measured in ultralow radiation background in the Romanian underground laboratory in salt mine in Slanic-Prahova. The main expected results is an up to date quantification of the radiation sources of the background of the Black Sea coastal environment. (authors)

  6. Spatial and depth wise characterization of radionuclides and minerals in various beach sediments from high background radiation area, Kerala, India

    International Nuclear Information System (INIS)

    The activity concentrations (238U, 232Th and 40K) and mineralogical characterization of different layer (upper surface, first, second and third feet) Kerala beach sediments have been assessed with an aim of evaluating the radioactivity content profile, its relation to specific minerals and their distributions (spatial and depth wise). The eight different radiological indices are calculated for all samples and compared with either recommended values or the world average values of radioactivity content of the three primordial radionuclides to assess the complete radiological profile of the sediments. The radioactivity study suggests that the average specific activities of radionuclides (238U and 232Th) are higher than the world average values as given in UNSCEAR reports and all radiological parameters in all layer samples are more than the recommended safety levels. These results are on the expected lines since the samples are from a well-known high background radiation area. Using FTIR, mineralogical characteristics of the sediments were analyzed and the extinction coefficient is calculated to find the relative distribution of major minerals. The calculated values show that the amount of major minerals decreases in the order of quartz>calcite>kaolinite>microcline feldspar in all layers. To confirm the results obtained from FTIR, XRD analysis was also carried out. The observations made through the XRD technique are matched with FTIR observations. Statistical analyses (cluster and factor analysis) are carried out to assess the relation between the radionuclides and minerals, and also assess their distribution patterns in different layers. The analyses suggest that the concentration of 40K may have a strong association with the light mineral calcite and also suggest that spatial distributions of 40K and calcite are almost similar in every layer. The concentrations of 238U, 232Th and absorbed dose rate are evenly distributed (spatial) and other variables are randomly

  7. Study of the natural radiation background affected on the human body in some areas of Viet Nam

    International Nuclear Information System (INIS)

    The author had studied the natural radiation background in 68 districts belong 40 provinces and cities of Vietnam from 2002 to 2005. The estimated results clearly show that the average external irradiation dose levels and the average annual external radiation equivalent dose affected on the human body are 0.181± 0.0189 μSv/h and 1599 ± 171.8 μSv/year respectively, both are in normal limit; the highest levels are in Lai Chau district (Lai Chau province); the lowest levels are in Buon Ma Thuot city (DakLak province), Phuoc Son district (Quang Nam province), Tan An district (Long An province). The radon concentration in the human being and the average annual internal inhalation irradiation equivalent dose affected on the human beings are 26.9 ± 15.89 Bq/m3 and 392.88 ± 231.99 μSv/year respectively; the maximums are in Nha Trang city (Khanh Hoa province), Bac Binh district (Binh Phuoc province); the minimums are in Vung Tau city (Ba Ria- Vung Tau province), Tan An district (Long An province), Rach Gia district (Kien Giang province). The terrestrial radionuclide concentrations in the cereals, foodstuffs (rice, meat, vegetables), water, earth and the average annual internal irradiation equivalent dose are 829.2 ± 38.06 Bq/kg and 229.3 ± 67.70 μSv/year respectively; the highest levels are in Phong Tho district (Lai Chau province), Dien Bien city; the lowest levels are in Dong Xoai district (Binh Phuoc province), Tan An district (Long An province). The average total annual natural radiation background effective equivalent dose level affected on the human body is 2206.9 ± 529.30 μSv/year; the highest levels are in Lai Chau district (Lai Chau province); the lowest levels are in Tan An district (Long An province). The 14 maps of Natural Radiation Background in several localized regions belong 40 provinces and cities of Viet Nam had been set up. These results can reserve for serviceman and public health in the both wartime and peacetime. (author)

  8. The assessment of cytotoxic T cell and natural killer cells activity in residents of high and ordinary background radiation areas of Ramsar-Iran

    Directory of Open Access Journals (Sweden)

    Sajad Borzoueisileh

    2013-01-01

    Full Text Available The effective radiation dose of human from natural sources is about 2.4 mSv/y and the dose limit for radiation workers is 20 mSv/y. Ramsar, a city in Iran, has been the subject of concern in the last forty years for a high level of radiation measured in some spots as high as 260 mSv/y. Carcinogenesis is one of the most studied effects of radiation especially in high doses. Recent studies showed that the high level of natural radiation received by inhabitants of this area, paradoxically don′t have significant health effect. Natural killer (NK cells and cytotoxic T cells are the most important cells in tumor immune surveillance and CD107a is a widely expressed intracellular protein located in the lysosomal/endosomal membrane. CD107a transiently located on the cell membrane can be used as a marker of CD8 + T cell degranulation following stimulation. It is also expressed, to a lower extent, on activated NK cells. In this study, 60 healthy people were selected randomly and their consent obtained and confounding factors such as sex, age, life-styles was matched then the count of activated NK and CD8 + cells was compared in high and normal background radiation areas inhabitants of Ramsar. After filling the questionnaire and measurement of background radiation, blood samples of 30 healthy people from each region were analyzed immediately by means of flowcytometry. The leukocytes and their subsets were not significantly different between two groups and the count of active cells was higher in control group. The result shows that the changes in immune system occur due to radiation and maybe it is as a result of higher radiosensitivity of activated cells.

  9. The assessment of cytotoxic T cell and natural killer cells activity in residents of high and ordinary background radiation areas of Ramsar-Iran.

    Science.gov (United States)

    Borzoueisileh, Sajad; Monfared, Ali Shabestani; Abediankenari, Saeid; Mostafazadeh, Amrollah

    2013-01-01

    The effective radiation dose of human from natural sources is about 2.4 mSv/y and the dose limit for radiation workers is 20 mSv/y. Ramsar, a city in Iran, has been the subject of concern in the last forty years for a high level of radiation measured in some spots as high as 260 mSv/y. Carcinogenesis is one of the most studied effects of radiation especially in high doses. Recent studies showed that the high level of natural radiation received by inhabitants of this area, paradoxically don't have significant health effect. Natural killer (NK) cells and cytotoxic T cells are the most important cells in tumor immune surveillance and CD107a is a widely expressed intracellular protein located in the lysosomal/endosomal membrane. CD107a transiently located on the cell membrane can be used as a marker of CD8 + T cell degranulation following stimulation. It is also expressed, to a lower extent, on activated NK cells. In this study, 60 healthy people were selected randomly and their consent obtained and confounding factors such as sex, age, life-styles was matched then the count of activated NK and CD8 + cells was compared in high and normal background radiation areas inhabitants of Ramsar. After filling the questionnaire and measurement of background radiation, blood samples of 30 healthy people from each region were analyzed immediately by means of flowcytometry. The leukocytes and their subsets were not significantly different between two groups and the count of active cells was higher in control group. The result shows that the changes in immune system occur due to radiation and maybe it is as a result of higher radiosensitivity of activated cells. PMID:23531635

  10. The assessment of cytotoxic T cell and natural killer cells activity in residents of high and ordinary background radiation areas of Ramsar-Iran

    International Nuclear Information System (INIS)

    The effective radiation dose of human from natural sources is about 2.4 mSv/y and the dose limit for radiation workers is 20 mSv/y. Ramsar, a city in Iran, has been the subject of concern in the last forty years for a high level of radiation measured in some spots as high as 260 mSv/y. Carcinogenesis is one of the most studied effects of radiation especially in high doses. Recent studies showed that the high level of natural radiation received by inhabitants of this area, paradoxically don't have significant health effect. Natural killer (NK) cells and cytotoxic T cells are the most important cells in tumor immune surveillance and CD107a is a widely expressed intracellular protein located in the lysosomal/endosomal membrane. CD107a transiently located on the cell membrane can be used as a marker of CD8 + T cell degranulation following stimulation. It is also expressed, to a lower extent, on activated NK cells. In this study, 60 healthy people were selected randomly and their consent obtained and confounding factors such as sex, age, life-styles was matched then the count of activated NK and CD8 + cells was compared in high and normal background radiation areas inhabitants of Ramsar. After filling the questionnaire and measurement of background radiation, blood samples of 30 healthy people from each region were analyzed immediately by means of flowcytometry. The leukocytes and their subsets were not significantly different between two groups and the count of active cells was higher in control group. The result shows that the changes in immune system occur due to radiation and maybe it is as a result of higher radiosensitivity of activated cells. (author)

  11. Role of light and heavy minerals on natural radioactivity level of high background radiation area, Kerala, India.

    Science.gov (United States)

    Ramasamy, V; Sundarrajan, M; Suresh, G; Paramasivam, K; Meenakshisundaram, V

    2014-02-01

    Natural radionuclides ((238)U, (232)Th and (40)K) concentrations and eight different radiological parameters have been analyzed for the beach sediments of Kerala with an aim of evaluating the radiation hazards. Activity concentrations ((238)U and (232)Th) and all the radiological parameters in most of the sites have higher values than recommended values. The Kerala beach sediments pose significant radiological threat to the people living in the area and tourists going to the beaches for recreation or to the sailors and fishermen involved in their activities in the study area. In order to know the light mineral characterization of the present sediments, mineralogical analysis has been carried out using Fourier transform infrared (FTIR) spectroscopic technique. The eight different minerals are identified and they are characterized. Among the various observed minerals, the minerals such as quartz, microcline feldspar, kaolinite and calcite are major minerals. The relative distribution of major minerals is determined by calculating extinction co-efficient and the values show that the amount of quartz is higher than calcite and much higher than microcline feldspar. Crystallinity index is calculated to know the crystalline nature of quartz present in the sediments. Heavy mineral separation analysis has been carried out to know the total heavy mineral (THM) percentage. This analysis revealed the presence of nine heavy minerals. The minerals such as monazite, zircon, magnetite and illmenite are predominant. Due to the rapid and extreme changes occur in highly dynamic environments of sandy beaches, quantities of major light and heavy minerals are widely varied from site to site. Granulometric analysis shows that the sand is major content. Multivariate statistical (Pearson correlation, cluster and factor) analysis has been carried out to know the effect of mineralogy on radionuclide concentrations. The present study concluded that heavy minerals induce the (238)U and (232)Th

  12. Are the inhabitants of high background radiation areas of Ramsar more radioresistant? scope of the problem and the need for future studies

    International Nuclear Information System (INIS)

    Background/objective: Ramsar in northern Iran is among the world's well-known areas with highest levels of natural radiation. Annual exposure levels in areas with elevated levels of natural radiation in Ramsar are up to 260 mGy y-1 and average exposure rates are about 10 mGy y-1 for a population of about 2000 residents. Due to the local geological features, which include high levels of radium in rocks, soils, and groundwater, Ramsar residents are also exposed to high levels of alpha activity in the form of ingested radium and radium decay progeny as well as very high radon levels (over 1000 MBq m-3) in their dwellings. In some cases, the inhabitants of these areas receive doses much higher than the current ICRP-60 dose limit of 20 mSv y-1 set for radiation workers. The extraordinary levels of natural radiation in Ramsar prompted us to assess the radiation susceptibility of the residents. Material and methods: venous blood samples were taken from 7 healthy blood donors of both sexes who lived in some areas of Ramsar with highest levels of natural radiation(dose rates were up to 155μ Sv h-1) and 5 healthy persons from a nearby control area. Standard condition for cell cultivation, irradiation and analysis of chromosome aberrations was used. The cells were exposed to the challenge dose of 1.5 Gy of Co-60 gamma ray 48 hours after PHA stimulation. Using mean chromosomal aberration per cell, the expected numbers of aberrations were calculated. Results: Lymphocytes of Ramsar residents when subjected to 1.5 Gy of Gamma rays, showed fewer chromosome aberrations compared to residents in a nearby control area. These findings clearly show that high levels of natural radiation may induce radio adaptive response. Interestingly. Conclusion: this radio adaptation phenomenon was found in individuals who received doses as much as a few hundred times more than the inhabitants of a nearby control area. More research is needed to precisely clarify if it is possible to relax the

  13. Evaluation of DNA damage in the root cells of Allium cepa seeds growing in soil of high background radiation areas of Ramsar - Iran

    Energy Technology Data Exchange (ETDEWEB)

    Saghirzadeh, M. [Department of Basic Science, Gonabad University of Medical Sciences, Gonabad (Iran, Islamic Republic of); Gharaati, M.R. [Faculty of Science, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Mohammadi, Sh. [Nuclear Science and Technology Research Institute (NSTRI), Radiation Applications Research School, Tehran 11365-3486 (Iran, Islamic Republic of)], E-mail: smohammadi@aeoi.org.ir; Ghiassi-Nejad, M. [Faculty of Science, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

    2008-10-15

    Plants are unique in their ability to serve as in situ monitors for environmental genotoxins. We have used the alkaline comet assay for detecting induced DNA damage in Allium cepa to estimate the impact of high levels of natural radiation in the soils of inhabited zones of Ramsar. The average specific activity of natural radionuclides measured in the soil samples for {sup 226}Ra was 12,766 Bq kg{sup -1} whereas in the control soils was in the range of 34-60 Bq kg{sup -1}. A positive strong significant correlation of the DNA damage in nuclei of the root cells of A. cepa seeds germinated in the soil of high background radiation areas with {sup 226}Ra specific activity of the soil samples was observed. The results showed high genotoxicity of radioactively contaminated soils. Also the linear increase in the DNA damage indicates that activation of repair enzymes is not triggered by exposure to radiation in HBRA.

  14. 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. PMID:26065929

  15. Natural background radiation in Canada

    International Nuclear Information System (INIS)

    Published airborne gamma ray survey data from 33 areas of Canada were used to compile information on the average ground level exposure from natural radiation. The exposures at ground level were calculated from the surface concentrations of potassium, uranium and thorium. The highest levels of radioactivity were found in northern Canada and were generally related to granitic rocks; the lowest levels with the Athabasca sandstone. Summer outdoor exposure rates have a population-weighted average of 3.7 +- 2.3 μR.h-1, of which 48 percent orginated from potassium, 43 percent from the thorium series and 9 percent from the uranium series. This low level of radioactivity, compared to worldwide data, has resulted from erosion of a geologically old continental crust in which radioactivity decreases with depth. When seasonal variations of soil moisture and snow cover are considered, the annual population-weighted average outdoor exposure rate decreases to 2.8 +- 1.7 μR.h-1 corresponding to an annual outdoor dose-equivalent of 150 +- 90 μSV. Factors increasing the annual outdoor dose-equivalent are cosmic radiation (320 +- 30 μSV) and the internal radioactivity of the body (190 μSV). Using the ratio between indoor and outdoor values for worldwide published data, the average annual Canadian whole-body dose-equivalent from all sources of natural radiation is estimated to be 690 +-130 μSV

  16. Role of light and heavy minerals on natural radioactivity level of high background radiation area, Kerala, India

    International Nuclear Information System (INIS)

    Natural radionuclides (238U, 232Th and 40K) concentrations and eight different radiological parameters have been analyzed for the beach sediments of Kerala with an aim of evaluating the radiation hazards. Activity concentrations (238U and 232Th) and all the radiological parameters in most of the sites have higher values than recommended values. The Kerala beach sediments pose significant radiological threat to the people living in the area and tourists going to the beaches for recreation or to the sailors and fishermen involved in their activities in the study area. In order to know the light mineral characterization of the present sediments, mineralogical analysis has been carried out using Fourier transform infrared (FTIR) spectroscopic technique. The eight different minerals are identified and they are characterized. Among the various observed minerals, the minerals such as quartz, microcline feldspar, kaolinite and calcite are major minerals. The relative distribution of major minerals is determined by calculating extinction co-efficient and the values show that the amount of quartz is higher than calcite and much higher than microcline feldspar. Crystallinity index is calculated to know the crystalline nature of quartz present in the sediments. Heavy mineral separation analysis has been carried out to know the total heavy mineral (THM) percentage. This analysis revealed the presence of nine heavy minerals. The minerals such as monazite, zircon, magnetite and illmenite are predominant. Due to the rapid and extreme changes occur in highly dynamic environments of sandy beaches, quantities of major light and heavy minerals are widely varied from site to site. Granulometric analysis shows that the sand is major content. Multivariate statistical (Pearson correlation, cluster and factor) analysis has been carried out to know the effect of mineralogy on radionuclide concentrations. The present study concluded that heavy minerals induce the 238U and 232Th

  17. Assessment of spatial distribution and radiological hazardous nature of radionuclides in high background radiation area, Kerala, India

    International Nuclear Information System (INIS)

    The concentration and distribution of the natural radionuclides (238U, 232Th and 40K) have been analyzed for the beach sediments of Kerala with an aim of evaluating the radiation hazards. The ranges of activity concentrations of 238U, 232Th and 40K are BDL—1187±21.7 Bq/kg, BDL—5328±23.2 Bq/kg and BDL—693±31.2 Bq/kg respectively. Radiological parameters such as absorbed dose rate, annual effective dose equivalent, annual gonadal dose equivalent, radium equivalent, hazard index, gamma Index, activity utilization index and excess lifetime cancer risk are calculated to know the complete radiological hazardous nature. Concentration of radionuclides (238U and 232Th) and all the calculated radiological parameters are higher in site number S23 (Chavara beach) due to the presence of rich deposits of black sands. Average concentrations of radionuclides (238U and 232Th) and all calculated radiological parameters are higher than the recommended level. Both univariate and multivariate statistical analyses were applied effectively to assess the distribution of the radionuclides. Univariate statistical analysis shows that the confirmation of infrequent extreme deviations of all radioactive variables. Cluster analysis shows that light minerals play a role in cluster I sampling sites and heavy minerals may be played in sampling sites of other clusters. Calculated activity ratio confirmed the presence of light and heavy minerals in above mentioned sampling sites. The Kerala beach sediments pose significant radiological threat to the people living in the area and tourists going to the beaches for recreation or to the sailors and fishermen involved in their activities in the study area. - Highlights: ► The concentration and distribution of the natural radionuclides have been analyzed for the Kerala beach sediments. ► Average concentrations of 238U and 232Th, and all calculated radiological parameters are higher than the recommended level. ► Univariate statistical

  18. Measurement of thorium and uranium activity with rare earth elements in soil samples near Chhatrapur, Orissa, India a natural high background radiation area

    International Nuclear Information System (INIS)

    The main aim of this present study is to evaluate the level of thorium and uranium activity as well as rare earth elements in a natural high background radiation area (HBRA) near Chhatrapur of Orissa state in India. Soil samples collected from HBRA were analyzed by γ-ray spectrometry as well as inductively coupled plasma mass spectrometry (ICP-MS). The radioactivity is found to be mainly contributed from thorium. Concentration of thorium and TiO2 is reported to be very high compared to normal abundance in crystal rocks. A large variation in absorbed gamma dose in air was observed

  19. Dose-effect relationship in production of dicentrics and rings in blood lymphocytes of individuals living in high background radiation area

    International Nuclear Information System (INIS)

    Objective: To explore the dose-effect relationship in the production of chromosome aberrations by high background radiation by using statistically appropriate individual measurements. Methods: Chromosome analysis was performed in separated blood lymphocytes of 39 family members of different ages from either high background radiation area (HBRA) or control area (CA). Individual cumulative doses ranged from 23.9-261.3 and 5.2-29.8 mGy for HBRA and CA, respectively. A total of about 100,000 cells were scored and dicentric and ring chromosome (dic + Rc) aberrations recorded. Results: In the case of HBRA, individual chromosome aberration frequencies increased with age within each family. The increasing trend was in general not significantly different among families. The increase in individual aberration was closely correlated with age and cumulative dose. Age-and dose-effect relationship fit well the linear equation: Y = 0.0448X + 0.4913 (R2 = 0.7814) for age and Y 0.0156X + 0.5715 (R2 = 0.7061) for cumulative dose, respectively. In the case of CA, there was no significant difference in aberration yields among individuals of different ages, and the group mean aberration frequency was 1.24 +- 0.69 x 10-3. Conclusions: Dic and Rc can continuously accumulate over a lifetime chronic low dose exposures, and can serve as a reliable biological indicator. However, the ultimate sensitivity is about 50 mGy

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

    Science.gov (United States)

    Yuan, Y; Morishima, H; Shen, T; Koga, T; Wei, L; Sugahara, T

    2000-10-01

    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: (1) integrating measurements of Rn-222 and Rn-220 concentrations; (2) eqilibrium factor F for Rn-222 and alpha-potential energy value of Rn-220; (3) external gamma radiation in places where radon measurements were undertaken; (4) 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Yongling; Shen Tong [Labor Hygiene Inst. of Human Province, Changsha (China); Morishima, Hiroshige; Koga, Taeko; Wei Luxin; Sugahara, Tsutomu

    2000-10-01

    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)

  2. The world's high background natural radiation areas (HBNRAs) revisited: A broad overview of the dosimetric, epidemiological and radiobiological issues

    International Nuclear Information System (INIS)

    The residents of the world's high background natural radiation areas (HBNRAs), such as Ramsar (in Iran), Guarapari (in Brazil), Orissa and Kerala (in India) and Yangjiang (in China) have lived in these areas for generations under extraordinary radiation fields. The failure of earlier epidemiological studies to report any substantial increase in cancer incidence in HBNRAs has raised some controversy regarding the validity of the linear no-threshold hypothesis. This paper reviews some of the most recent studies of HBNRAs with the intent of stimulating greater research interest in the dosimetric, epidemiological and radiobiological issues related to the world's HBNRAs and proposes solutions to the challenges facing HBNRA studies. This paper may serve as a useful reference for some of the harder-to-find literature. - Highlights: • Some of the challenging issues of HBNRAs have not been resolved. • A literature review of the most recent studies of HBNRAs has been conducted. • An overview of some of the challenging issues and viable solutions are presented

  3. Dose-effect relationship of dicentric and ring chromosomes in lymphocytes of individuals living in the high background radiation areas in China

    International Nuclear Information System (INIS)

    Chromosomes of 39 healthy family members (3 generations from 13 families) living both in the high-level background radiation areas (HBRA) and the control areas (CA) were studied. Cumulative dose from birth to the time of blood sampling was estimated by calculating measured exposure rate in each individual. The cumulative doses ranged 30.9-358.9 and 6.0-59.2 mGy for HBRA and CA, respectively. Peripheral lymphocyte chromosome preparations were made according to our improved method. Dicentric and ring chromosomes (Dic+Rc) were scored in average 2,527 cells per individual in HBRA and 2,694 cells in CA under a microscope equipped with an automated stage. A positive correlation between Dic+Rc and age was found in HBRA, while no such dose relationship was clear in CA. The frequency of Dic+Rc linearly increases over lifetime due to chronic low dose exposure and it is likely that the activation of repair enzymes is not triggered in the present HBRA. Threshold dose (rate) of the induction of chromosome aberrations, if any, is below the present dose (rate) level. (author)

  4. Mass spectrometric determination of thorium and uranium in human hair and nails in a high background natural radiation area of Serbia

    International Nuclear Information System (INIS)

    The content of elements in human hair and nails can be considered as alternative bio-indicators of public exposure to natural radionuclides and other toxic metals over a long period of months or even years. The level of elements in hair and nails usually reflect their presence in other tissues of body. Hair and nails were collected from a high natural background radiation area in Serbia to analyze the concentration of thorium, uranium and selected trace elements such as Mn, Ni, Cu, Sr, Cd, and Cs using inductively coupled plasma mass spectrometry. Th and U concentrations in hair varied from 0.0002 to 0.0276 μg/g and 0.0002 to 0.0771 μg/g, respectively. The concentration in nail varied from 0.0023 to 0.0564 μg/g and 0.0025 to 0.0447 μg/g, for Th and U, respectively. There was a large variation for other metal's concentrations in hair, which may be due to different geological origin and anthropogenic activities. (author)

  5. Excess relative risk for solid cancer mortality during prolonged exposure to high-background natural radiation in Yangjiang area of China

    International Nuclear Information System (INIS)

    Objective: To estimate the excess relative risk for solid cancer associated with chronically exposure to high-background natural radiation in Yangjiang area of China. Methods: Based on hamlet-specific environmental doses and sex-and age-specific occupancy factors, the authors calculated cumulative doses for each cohort member. Assuming a linear dose response relationship and using cancer mortality data for the period 1979-1995 and Poisson model, the authors estimated the excess relative risk (ERR) for solid cancer. Results: The ERR per Sv of all solid cancer is estimated to be -0.11 (95% CI, -0.67, 0.69 to 95%). The corresponding figures for cancers of liver, nasopharynx, lungs and stomach are -0.99 (-1.60, 0.10), 0.10 (-1.21, 3.28), -0.68 (-1.58, 1.66) and -0.27 (-1.37, 2.69) respectively. Conclusion: The association between ERR of solid cancer and dose can not be found

  6. Excess lifetime cancer risk projections for populations who lives in high background radiation areas as a useful risk communication to the Brazilian experience

    International Nuclear Information System (INIS)

    The present report aims to demonstrate how lifetime risk projections for residents in HBRAs can be used as a risk communication tool, on the basis of an experience of Monte Alegre, a small city in north of Brazil, which has been economically and socially affected due to rumors of environmental contamination and increased radiation related diseases. A comprehensive radiological characterization have been conducted in Monte Alegre and neighborhood cities Alenquer and Prainha which includes indoor radon concentration, indoor and outdoor external gamma radiation, and natural radionuclides concentration in water and crops. Cumulative dose to specific organs were estimated taking into account the environment exposure pathways. Using the NCI radioepidemiological program (NCJ Rad-Risk), which is based mainly on BEIR VII models, we estimated overall and site-specific lifetime cancer risk (LCR) for males and females based on estimated mean dose of all exposure other than radon. For radon, model from BEIR VI was used to estimate the lifetime lung cancer risk and uncertainties was estimated using Monte Carlo simulation. Adjustment for Brazilian expected survival and baseline cancer risk was considered. We aim to discuss in this report how risk projections can he used as a useful risk communication tool. To provide a sound evaluation, comparisons of the estimated lifetime cancer risk due to the enhanced natural radiation to that estimated for population who lives in normal background cities and also to the general baseline lifetime cancer risk were carried on. The use of risk projections are particularly important given the effects of relatively low doses and hence the quantification of a priori relatively small risk. In conclusion, the Brazilian experience in conducting such small epidemiological studies in residents of HBRAs has demonstrated that these studies have been driven just to attend public expectation and/or regulatory agencies request and were most useful for risk

  7. Biosorption of cadmium by Brevundimonas sp. ZF12 strain, a novel biosorbent isolated from hot-spring waters in high background radiation areas

    Energy Technology Data Exchange (ETDEWEB)

    Masoudzadeh, Nasrin [Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of); Department of Biology, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Zakeri, Fardideh [Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of); National Radiation Protection Department - Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Lotfabad, Tayebe bagheri [Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of); Sharafi, Hakimeh [Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of); Department of Biology, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Masoomi, Fatemeh; Zahiri, Hoseein Shahbani; Ahmadian, Gholamreza [Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of); Noghabi, Kambiz Akbari, E-mail: Akbari@nigeb.ac.ir [Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Isolation and characterization of a novel cadmium-biosorbent (Brevundimonas sp. ZF12) from high background radiation areas. Black-Right-Pointing-Pointer Brevundimonas sp. ZF12 caused 50% removal of cadmium at the concentration level of 250 ppm. Black-Right-Pointing-Pointer Solution pH values used for the reusability study have powerful desorptive features to recover Cd ions sorbed onto the biomass. Black-Right-Pointing-Pointer This is the first study carried out so far for the cadmium removal from aqueous solutions by a novel biosorbent Brevundimonas sp. ZF12. Black-Right-Pointing-Pointer In our opinion, the isolate can be an attractive alternative to remove the cadmium-containing wastewaters. - Abstract: The aim of this study is to screen cadmium biosorbing bacterial strains isolated from soils and hot-springs containing high concentrations of radium ({sup 226}Ra) in Ramsar using a batch system. Brevundimonas sp. ZF12 strain isolated from the water with high {sup 226}Ra content caused 50% removal of cadmium at a concentration level of 250 ppm. The biosorption equilibrium data are fitted well by the Langmuir adsorption isotherm and kinetic studies indicated that the biosorption follows pseudo second-order model. The effect of different physico-chemical parameters like biomass concentration, pH, cadmium concentration, temperature and contact time on cadmium sorption was also investigated using FTIR, SEM and XRD analytical techniques. A high desorption efficiency (above 90%) was obtained using a pH range of 2.0-4.0. Reusability of the biomass was examined under consecutive biosorption-desorption cycles repeated thrice. In conclusion, Brevundimonas sp. ZF12 is proposed as an excellent cadmium biosorbent that may have important applications in Cd removal from wastewaters.

  8. Gamma radiation background measurements from Spacelab 2

    Science.gov (United States)

    Paciesas, William S.; Gregory, John C.; Fishman, Gerald J.

    1989-01-01

    A Nuclear Radiation Monitor incorporating a NaI(Tl) scintillation detector was flown as part of the verification flight instrumentation on the Spacelab 2 mission, July 29 to August 6, 1985. Gamma-ray spectra were measured with better than 20 s resolution throughout most of the mission in the energy range 0.1 to 30 MeV. Knowledge of the decay characteristics and the geomagnetic dependence of the counting rates enable measurement of the various components of the Spacelab gamma-ray background: prompt secondary radiation, earth albedo, and delayed induced radioactivity. The status of the data analysis and present relevant examples of typical background behavior are covered.

  9. Controllable forms of natural background radiation

    International Nuclear Information System (INIS)

    RENA is a research programm into the controllable forms of natural background radiation, which cover the activities originating from the naturally occurring radionuclides enhanced by human intervention. In the RENA-program emphasis lays upon the policy aspects of environmental-hygienic, economical and governmental character. (H.W.). 15 refs.; 2 tabs

  10. Remote Background Radiation Monitoring Using Zigbee Technology

    Directory of Open Access Journals (Sweden)

    Hamisu A. Adamu

    2014-03-01

    Full Text Available In this paper, a solution of remote background radiation monitoring, based on the concept of Wireless Sensor Network (WSN, is presented. Radiation dose rate measured by the sensor node is sent to the monitoring station through ZigBee wireless network operated on 2.4 GHz unlicensed Industrial Scientific Medical (ISM band. The system is calibrated for use for ionizing radiation dose rate range of between naturally occurring background radiation and 1.02 mSv/h. Power consumption of the sensor node is kept low by operating the node ZigBee radio with low duty cycle: i.e by keeping the radio awake only during data transmission/reception. Two ATmega8 microcontrollers, one each for sensor node and the monitoring station, are programmed to perform interfacing, data processing, and control functions. The system range of coverage is 124m for outdoor (line of site deployment and 56.8m for indoor application where 5 brick walls separated the sensor node and the monitoring station. Range of coverage of the system is extendable via the use of ZigBee router(s.

  11. Propagation of light in area metric backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Punzi, Raffaele; Wohlfarth, Mattias N R [Zentrum fuer Mathematische Physik und II. Institut fuer Theoretische Physik, Universitaet Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Schuller, Frederic P, E-mail: raffaele.punzi@desy.d, E-mail: fps@aei.mpg.d, E-mail: mattias.wohlfarth@desy.d [Max Planck Institut fuer Gravitationsphysik, Albert Einstein Institut, Am Muehlenberg 1, 14467 Potsdam (Germany)

    2009-02-07

    The propagation of light in area metric spacetimes, which naturally emerge as refined backgrounds in quantum electrodynamics and quantum gravity, is studied from first principles. In the geometric-optical limit, light rays are found to follow geodesics in a Finslerian geometry, with the Finsler norm being determined by the area metric tensor. Based on this result, and an understanding of the nonlinear relation between ray vectors and wave covectors in such refined backgrounds, we study light deflection in spherically symmetric situations and obtain experimental bounds on the non-metricity of spacetime in the solar system.

  12. Cosmic microwave background radiation: anisotropies and polarization

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Sergio Vitorino de Borba; Guaitolini Junior, J.T. [Universidade Federal do Espirito Santo (UFES), ES (Brazil). Dept. de Fisica

    2011-07-01

    Full text: The development of cosmological models which describe correctly the universe we live in is becoming more reliable, as the improvement of the measure tools provides us with more accurate information. The Cosmic Microwave Background Radiation (CMB) was discovered accidentally by Arno Penzias and Robert Wilson in early 60s, becoming a strong evidence in favor of the Big Bang model. This radiation, typical of a blackbody with maximum intensity in the microwave band, was already predicted by Gamov, Alpher and Herman and it's originated from the uncoupling between radiation and matter in recombination, at z = 1088. Nowadays, since no other observable in Cosmology provides us with information of such a distant past, studying CMB is of great importance for the process of the comprehension of the universe. The detection of small anisotropies at the temperatures distribution, which remain even after considering the universe recent phenomena and effects of referential movements, evidenced that the primordial universe was closer to the thermodynamic equilibrium and that the appearance of small inhomogeneities were the beginning of the formation of the structures we see today. These small anisotropies are important because from them it is possible to observe polarization at CMB. In a universe so perfectly homogeneous and isotropic, polarization would never exist. In this work, we calculate the behavior of light propagation in a disturbed universe, obtaining anisotropies from the potential variation at the radiation way and from the peculiar velocity of matter which spread radiation in our direction. At this point, the next purpose is to theoretically calculate these anisotropies in an alternative cosmological example, such as in Brans-Dicke theory or a model of an universe filled with a viscous fluid. Besides, with the Stokes Parameters describing the radiation field, we study the CMB polarization, in particular analyzing the polarization tensor in a 2-sphere as

  13. Spatial and vertical distributions of heavy metals and their potential toxicity levels in various beach sediments from high-background-radiation area, Kerala, India

    International Nuclear Information System (INIS)

    Graphical abstract: Graphical representation shows that concentrations of Cd and Pb and all the calculated indexes might have been influenced by the amount of total organic content and the Ni and Zn concentrations might have been influenced by sediment grain size (silt and clay). - Highlights: • Most of the metals are higher in S1 and other higher values are erratically distributed. • Moderate and severe degree of ecological risk is observed in different layers. • Surface and first feet samples had 21%, third feet samples had 49% of probability of toxicity. • Most of the studied metals and all calculated indexes are higher in third feet samples. • The calculated indexes might have been influenced by amount of total organic content. - Abstract: The spatial and vertical distribution of heavy metals and the sediment characteristics of beaches in Kerala, India (the upper surface sediments and the first, second and third one-foot-thick strata) were assessed in this study. The concentrations of most of the studied metals were highest at sampling site S1 (Cochin). The measured concentrations were compared with background and toxicological reference values. The results show that definite adverse biological effects are possible at most of the sampling sites due to the high Pb levels. Three different indexes were calculated to investigate the potential toxicity level. Most of the studied metals and all calculated indexes were highest in the third foot of sediment. Multivariate statistical analyses were performed and suggested that particular heavy metals, e.g., Pb, Cd, Cr and Ni, may represent contamination from a common source. The Cd and Pb concentrations and all the calculated index values show a relationship with the content of organic matter. The results of the present study suggest the recommendation that a systematic analysis is needed to monitor heavy metal levels in the studied area

  14. Thermal radiation of various gravitational backgrounds

    OpenAIRE

    Akhmedov, Emil T.; Akhmedova, Valeria; Pilling, Terry; Singleton, Douglas

    2006-01-01

    We present a simple and general procedure for calculating the thermal radiation coming from any stationary metric. The physical picture is that the radiation arises as the quasi--classical tunneling of particles through a gravitational barrier. We show that our procedure can reproduce the results of Hawking and Unruh radiation. We also show that under certain kinds of coordinate transformations the temperature of the thermal radiation will change in the case of the Schwarzschild black holes. ...

  15. Background radioactivity in the monazite areas of Kerala, India

    International Nuclear Information System (INIS)

    External radiation exposure measurements were carried out with natural CaF2 thermoluminescence dosimeters (TLD) in about 2500 dwellings and on about 10.000 persons living in monazite areas of south-west coast of India. Statistical analysis of the data indicate that the values are distributed lognormally. A systematic study was carried out a Manavalakurichi plant of Indian Rare Earths Ltd. and adjoining high background areas to obtain typical average radiation exposure to different categories of workers from both occupation and non-occupation. Results of thoron measurements from the exhaled breath of plant workers are presented from which the body burden of natural thorium deposited in lungs can be estimated. An important pathway of exposure, for which children are most susceptible, is non-specific ingestion of raw sand itself. Data obtained on the radonuclide content of urinary excretion of children belonging to two age groups are discussed. (orig.)

  16. Radiation-dominated area metric cosmology

    CERN Document Server

    Schuller, Frederic P

    2007-01-01

    We provide further crucial support for a refined, area metric structure of spacetime. Based on the solution of conceptual issues, such as the consistent coupling of fermions and the covariant identification of radiation fields on area metric backgrounds, we show that the radiation-dominated epoch of area metric cosmology is equivalent to that epoch in standard Einstein cosmology. This ensures, in particular, successful nucleosynthesis. This surprising result complements the previously derived prediction of a small late-time acceleration of an area metric universe.

  17. Activity concentrations of 226Ra, 228Th, and 40K in different food crops from a high background radiation area in Bitsichi, Jos Plateau, Nigeria.

    Science.gov (United States)

    Jibiri, N N; Farai, I P; Alausa, S K

    2007-03-01

    One of the three goals of the United Nations for sustainable food security is to ensure that all people have access to sufficient, nutritionally adequate, and safe food. Decades of tin mining in the Bitsichi area of the Jos Plateau, Nigeria, have left a legacy of polluted water supplies, impoverished agricultural land, and soil containing abnormally high levels of naturally occurring radioactive elements. In order to ascertain the radiological food safety of the population, different crops that constitute the major food nutritive requirements were collected directly across farmlands in the area. The activity concentrations of (226)Ra, (228)Th, and (40)K were determined in the food and soil samples using gamma-ray spectrometry. Additionally, in situ gamma dose rate measurements were performed on the farms using a pre-calibrated survey meter. The corresponding activity concentrations in the food crops ranged from below detection limit (BDL) to 684.5 Bq kg(-1) for (40)K, from BDL to 83.5 Bq kg(-1) for (226)Ra, and from BDL to 89.8 Bq kg(-1) for (228)Th. Activity concentrations of these radionuclides were found to be lower in cereals than in tubers and vegetables. As for the soil samples, activity concentrations of these radionuclides varied from BDL to 166.4 Bq kg(-1), from 10.9 to 470.6 Bq kg(-1), and from 122.7 to 2,189.5 Bq kg(-1) for (40)K, (226)Ra, and (228)Th, respectively. Average external gamma dose rates were found to vary across the farms from 0.50 +/- 0.01 to 1.47 +/- 0.04 microSv h(-1). Due to past mining activities, the soil radioactivity in the area has been modified and the concentration level of the investigated natural radionuclides in the food crops has also been enhanced. However, the values obtained suggest that the dose from intake of these radionuclides by the food crops is low and that harmful health effects are not expected. PMID:17211656

  18. Cosmic far-ultraviolet background radiation

    International Nuclear Information System (INIS)

    It is demonstrated that interstellar dust grains forward-scatter far-ultraviolet radiation extremely strongly: the value of the Henyey-Greenstein scattering parameter g at 1425 A is shown to be at least 0.75; the actual value is very likely greater than 0.9. Also, observations of the Virgo cluster of galaxies sets a limit tau > 2 x 1025 sec on the life-time of 17-20 eV/c2 heavy neutrinos, if such neutrinos are responsible for the gravitational binding of the cluster. (Auth.)

  19. Evaluation of background ionising radiation levels within Gwagwalada town, Abuja

    International Nuclear Information System (INIS)

    The background ionising radiation levels within Gwagwalada Town, Abuja has been carried out using Atomtex 1117M Radiation Monitor. Readings were taken in twelve different locations. Twenty different readings were taken at each location and the mean equivalent dose rate was used to calculate the annual equivalent dose rate. A total of 240 measurements were taken across the 12 locations in the study Area. It was observed that the average dose equivalent varied from 0.105±0.008 μSv/h to 0.114±0.015μSv/h with a mean of 0.109±0.013 μSv/h. The mean value from Ungwan Bassa shows the highest equivalent dose rate while the equivalent dose rate from Phase 3 was the lowest. Ungwan Dodo, Ungwan Gwari recorded the second and third highest in-situ gamma radiation of 0.113±0.013 μSv/h and 0.112±0.012 μSv/h respectively. The result shows that the entire equivalent dose rates of all the locations were below the value of the Standard Background Radiation of 0.133 μSv/h. The study also revealed that the average annual equivalent dose rate is 0.192±0.005 mSv/y which is lower than the value of 1.0 mSv/yr averaged over five consecutive years according to the dose limit recommended by the International Commission on Radiological Protection (ICRP).

  20. Evaluation of Background Ionization Radiation Level in some selected Dumpsites in Delta State, Nigeria

    OpenAIRE

    Avwiri, O Gregory; Emmanuel, O Esi

    2014-01-01

    This paper reports on the evaluation of background Ionization radiation level (BIR) in some selected Dumpsites in Uvwie, Udu and Ughelli North Local government area of Delta State, Nigeria. Background ionization radiation measurements were carried out in five Dumpsites. An in- situ measurement was done using a well calibrated nuclear radiation meters Radalert-100 and a geographical positioning system (GPS). Readings were taken once in a week for one month in ten different locations within eac...

  1. Distribution of uranium, thorium and some stable trace and toxic elements in human hair and nails in Niška Banja Town, a high natural background radiation area of Serbia (Balkan Region, South-East Europe)

    International Nuclear Information System (INIS)

    Human hair and nails can be considered as bio-indicators of the public exposure to certain natural radionuclides and other toxic metals over a long period of months or even years. The level of elements in hair and nails usually reflect their levels in other tissues of body. Niška Banja, a spa town located in southern Serbia, with locally high natural background radiation was selected for the study. To assess public exposure to the trace elements, hair and nail samples were collected and analyzed. The concentrations of uranium, thorium and some trace and toxic elements (Mn, Ni, Cu, Sr, Cd, and Cs) were determined using inductively coupled plasma mass spectrometry (ICP-MS). U and Th concentrations in hair varied from 0.0002 to 0.0771 μg/g and from 0.0002 to 0.0276 μg/g, respectively. The concentrations in nails varied from 0.0025 to 0.0447 μg/g and from 0.0023 to 0.0564 μg/g for U and Th, respectively. We found significant correlations between some elements in hair and nails. Also indications of spatial clustering of high values could be found. However, this phenomenon as well as the large variations in concentrations of heavy metals in hair and nail could not be explained. As hypotheses, we propose possible exposure pathways which may explain the findings, but the current data does not allow testing them. - Highlights: • Niška Banja is a high radiation background area of Serbia with high radium (226Ra) concentration. • Measurement of thorium, uranium and some selected trace elements in hair and nails were carried out using ICP-MS. • Elevated concentration of naturally occurring radionuclides such as U and Th in environmental samples was determined. • We have assumed to find a suitable relationship between hair and nail samples with the natural samples

  2. Investigation of background radiation and associated anomalies in Rifle, Colorado

    International Nuclear Information System (INIS)

    In addition to examining anomalies and establishing the background gamma exposure rate range, the study presents a formula to convert thousand counts per minute (kcpm) from a gamma scintillator to microroentgen per hour (μRh) for the Rifle region. Also, a method is presented to identify contaminated areas containing excess 226Ra, by using a GR-410 gamma spectrometer. This method is suggested to be applied to all property surveys in the Rifle area. The Wasatch Formation, which outcrops extensively in the Rifle area, was found to have a major influence on the background radiation. Varying potassium concentrations and naturally occurring uranium in this rock unit reveal varying gamma exposure rates. Examining RaTh ratios from laboratory analysis of soil samples or use of RaTh ratios from GR-410 gamma spectrometer readings on site allows discrimination between mill related contamination and naturally occuring radioactivity. Radioactive coal clinkers were found used as fill material throughout the Rifle region and have been determined to be a product of the mill and subject to remediation. Finally, windblown mill tailings contamination is addressed in some detail. Mill tailings redistributed from the Rifle uranium mill tailings piles by prevailing winds were detected extensively on vicinity properties in Rifle. Some radioactive components of the windblown tailings were found to have leached into the subsurface soil. The combination of Wasatch Formation, radioactive coal clinkers, and windblown tailings accounts for many of the anomalous gamma exposure rates observed by the radiological survey teams. 11 refs., 10 figs., 3 tabs

  3. An investigation of gamma background radiation in Hamadan province, Iran

    International Nuclear Information System (INIS)

    The general population, everywhere in the world is exposed to a small dose of ionising radiation from natural sources. Stochastic effects such as cancer and genetic disorders are caused when living creatures are exposed to low doses. In Iran, it is measured in some cities, especially in high-background areas such as Ramsar, but so far there is no measurement in the Hamadan province. Hamadan is located in the west of Iran. Measurements were performed using a RDS-110 survey meter, CaSO4:Dy thermoluminescence dosimetries (TLDs) and a Harshaw 4000 TLD reader. To estimate the dose rate outdoors, four stations along the main directions (north, south, west and east) and one in the town centre were selected. Mean annual X and gamma equivalent dose in Hamadan province are 1.12±0.22 and 1.66±0.07 mSv, which related to RDS-110 survey meter and TLDs measurements, respectively. The TLDs and RDS-110 results are representative of the external photon radiation doses for the selected monitoring locations and for those locations for the hours during which the measurements were taken, respectively. Maximum and minimum of external photon radiation doses are related to Hamadan and Kaboudar-Ahang towns, respectively. According to the results of the study, it seems that the annual X and gamma equivalent dose in Hamadan province exceeded the global mean external exposure amounts by the UNSCEAR, and further studies are needed to measure internal exposures to determine the total environmental radiation level in Hamadan province. (authors)

  4. Measurements of background gamma radiation on Spacelab 2

    Science.gov (United States)

    Fishman, G. J.; Paciesas, W. S.; Gregory, J. C.

    1987-01-01

    A nuclear radiation monitor (NRM) which was flown as part of the verification instrumentation on the Spacelab 2 mission (July 29 - August 6, 1985) recorded spectra every 20 seconds and counting rates in coarse energy bands on finer time scales. The gamma radiation environment on Spacelab is characterized by cosmic-ray and trapped proton secondary radiation in the Spacelab/Shuttle, earth albedo radiation, and delayed induced radioactivity in the detector and surrounding materials. It is found that passages through South Atlantic Anomaly protons produce a well-defined background enhancement.

  5. Pre operational background radiation monitoring around Kudankulam Nuclear Power Project site - a decade long experience

    International Nuclear Information System (INIS)

    Pre-operational environmental background radiation monitoring around nuclear power plants is very important to understand baseline values existing in the site and also to identify any hot spots of naturally occurring high background radiation areas and their sources. These baseline measurements will act as a benchmark for future comparison after the reactors go into operation. The radiation measurements are continued during the operational phase of the plant and the results are compared to see whether there is any impact of the operation of the plant on the environment. A comprehensive background radiation monitoring plan has been in vogue at site from 2004 to meet this objective. This paper describes the different monitoring strategies adopted around Kudankulam Nuclear Power Project site and throws light on the pre operational background radiation levels in the environment

  6. A background radiation survey along the transcontinental railway in Australia

    International Nuclear Information System (INIS)

    This article reports a survey, carried out during a period from October 31 to November 3, 1994 in Australia, as well as some basic techniques of train-borne measurements for estimating outdoor gamma-ray dose rates. Surface rock and bedrock data are presented for convenience for geological analysis. Cosmic-ray dose rates estimated from atmospheric pressure data are also presented for researchers who are interested in total background radiation dose rates. It was found that gamma levels can be high in the western area. The dose rate data were based on the shielding correction factor evaluated at platforms in many stations. To confirm the validity of this method, the data from train-borne surveys in central Japan were compared with the present Australian data. There were, to some extent, correlations between them. The present study suggests that the train-borne measurements are useful for surveying wide area in a short time with an error of about 20%. (N.K.)

  7. Human exposure to high natural background radiation: what can it teach us about radiation risks?

    Energy Technology Data Exchange (ETDEWEB)

    Hendry, Jolyon H; Sohrabi, Mehdi; Burkart, Werner [Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna (Austria); Simon, Steven L [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); Wojcik, Andrzej [Institute of Nuclear Chemistry and Technology, Warsaw (Poland); Cardis, Elisabeth [Centre for Research in Environmental Epidemiology (CREAL), Municipal Institute of Medical Research (IMIM-Hospital del Mar) and CIBER Epidemiologia y Salud Publica - CIBERESP, Barcelona (Spain); Laurier, Dominique; Tirmarche, Margot [Radiobiology and Epidemiology Department, Radiological and Human Health Division, Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses (France); Hayata, Isamu [National Institute of Radiological Sciences, Chiba (Japan)], E-mail: jhendry2002uk@yahoo.com

    2009-06-01

    Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of {sup 222}Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation. Much of the direct information about risk related to HNBR comes from case-control studies of radon and lung cancer, which provide convincing evidence of an association between long-term protracted radiation exposures in the general population and disease incidence. The success of these studies is mainly due to the careful organ dose reconstruction (with relatively high doses to the lung), and to the fact that large-scale collaborative studies have been conducted to maximise the statistical power and to ensure the systematic collection of information on potential confounding factors. In contrast, studies in other (non-radon) HNBR areas have provided little information, relying mainly on ecological designs and very rough effective dose categorisations. Recent steps taken in China and India to establish cohorts for follow-up and to conduct nested case-control studies may provide useful information about risks in the future, provided that careful organ dose reconstruction is possible and information is collected on potential confounding factors.

  8. Survey of lens opacities of residents living in high background radiation area in Yangjiang,Guangdong province%广东阳江辐射高本底地区居民眼晶状体混浊调查

    Institute of Scientific and Technical Information of China (English)

    王焱; 秋叶澄伯; 孙全富

    2015-01-01

    Objective To study the effect of long-term low dose ionizing radiation on ocular lens opacities.Methods With random cluster sampling,the residents aged over 45 years were selected from two villages in high background radiation areas(HBRA) in Yangxi County and three control areas in Enping County in Guangdong province,and a questionnaire survey was conducted and slit-lamp eye lens opacity was checked.Results With adjustment of gender,age,smoking and drinking factors compared with the residents living in control areas,the risks of eye lens opacities,cortical opacities,nuclear opacities and posterior subcapsular opacities for residents living in HBRA were 0.99 (95% CI:0.72-1.37),1.45 (95% CI:0.99-2.11),0.82 (95% CI:0.60-1.14),and 4.05 (95% CI:1.56-10.46),respectively.Conclusions Long-term low dose ionizing radiation exposure is probably an important risk factor for eye posterior subcapsular lens opacities.%目的 研究长期低剂量电离辐射照射对眼晶状体混浊的影响.方法 在广东省辐射高本底地区和对照地区分别随机整群抽取2个村和3个村的年龄≥45岁的常住居民,进行问卷调查和裂隙灯眼晶状体混浊检查.采用非条件logistic回归分析探讨眼晶状体混浊的危险因素.结果 调整性别、年龄、吸烟、饮酒之后,与对照地区居民相比,辐射高本底地区居民患眼晶状体混浊、皮质性混浊、核性混浊和后囊下混浊的OR值分别为0.99(95% CI:0.72 ~ 1.37)、1.45(95% CI:0.99 ~2.11)、0.82(95% CI:0.60 ~ 1.14)、4.05(95% CI:1.56 ~ 10.46),提示高本底地区居民眼晶状体后囊下混浊的危险性增高.结论 长期低剂量电离辐射受照可能是眼晶状体后囊下混浊的重要危险因素.

  9. The origin of the diffuse background gamma radiation

    Science.gov (United States)

    Stecker, F. W.; Puget, J. L.

    1974-01-01

    Recent observations provided evidence for diffuse background gamma radiation extending to energies beyond 100 MeV, and evidence of isotropy and implied cosmological origin. Significant features in the spectrum of this background radiation were observed which provide evidence for its origin in nuclear processes in the early stages of big-bang cosmology, and connect these processes with the galaxy formation theory. A test of the theory is in future observations of the background radiation in the 100 MeK to 100 GeV energy range which are made with large orbiting spark-chamber satellite detectors. The theoretical interpretations of present data, their connection with baryon-symmetric cosmology and galaxy formation theory, and the need for future observations are discussed.

  10. The origin of the diffuse background gamma-radiation

    Science.gov (United States)

    Stecker, F. W.; Puget, J. L.

    1974-01-01

    Recent observations have now provided evidence for diffuse background gamma radiation extending to energies beyond 100 MeV. There is some evidence of isotropy and implied cosmological origin. Significant features in the spectrum of this background radiation have been observed which provide evidence for its origin in nuclear processes in the early stages of the big-band cosmology and tie in these processes with galaxy fromation theory. A crucial test of the theory may lie in future observations of the background radiation in the 100 MeV to 100 GeV energy range which may be made with large orbiting spark-chamber satellite detectors. A discussion of the theoretical interpretations of present data, their connection with baryon symmetric cosmology and galaxy formation theory, and the need for future observations are given.

  11. Scalar Radiation in the Background of a Naked Singularity

    CERN Document Server

    Dey, Anshuman; Sarkar, Tapobrata

    2013-01-01

    We study scalar radiation spectra from a particle in circular orbit, in the background of the Janis-Newman-Winicour (JNW) naked singularity. The differences in the nature of the spectra, from what one obtains with a Schwarzschild black hole, is established. We also compute the angular distribution of the spectra.

  12. Background Radiation Studies at LHCb Using Geant4

    CERN Document Server

    Daquino, G G; Folger, G

    2004-01-01

    This paper aims to describe the feasibility studies performed to evaluate the background radiation levels in the LHCb experiment with Geant4. LHCb is one of the experiments that will operate at the LHC (Large Hadron Collider) under construction at CERN. The simulation toolkit Geant4 has been used to model the interactions of particles with the detector. Geant4 is a software toolkit developed and maintained by a world-wide collaboration of physicists and computer scientists. The principal monitored distributions in this study are the dose and the fluence of certain particles in specific locations of the experiment. The dose is defined as the energy delivered in a volume per unit of the volume mass, while the fluence is defined as the number of particles passing through a surface per unit of area. Energy spectra need also to be evaluated to take into account the energy distribution of these particles, since specific problems in the electronics can be caused by particles of certain energies. For ...

  13. Background Radiation Measurements at High Power Research Reactors

    CERN Document Server

    Ashenfelter, J; Baldenegro, C X; Band, H R; Barclay, G; Bass, C D; Berish, D; Bowden, N S; Bryan, C D; Cherwinka, J J; Chu, R; Classen, T; Davee, D; Dean, D; Deichert, G; Dolinski, M J; Dolph, J; Dwyer, D A; Fan, S; Gaison, J K; Galindo-Uribarri, A; Gilje, K; Glenn, A; Green, M; Han, K; Hans, S; Heeger, K M; Heffron, B; Jaffe, D E; Kettell, S; Langford, T J; Littlejohn, B R; Martinez, D; McKeown, R D; Morrell, S; Mueller, P E; Mumm, H P; Napolitano, J; Norcini, D; Pushin, D; Romero, E; Rosero, R; Saldana, L; Seilhan, B S; Sharma, R; Stemen, N T; Surukuchi, P T; Thompson, S J; Varner, R L; Wang, W; Watson, S M; White, B; White, C; Wilhelmi, J; Williams, C; Wise, T; Yao, H; Yeh, M; Yen, Y -R; Zhang, C; Zhang, X

    2016-01-01

    Research reactors host a wide range of activities that make use of the intense neutron fluxes generated at these facilities. Recent interest in performing measurements with relatively low event rates, e.g. reactor antineutrino detection, at these facilities necessitates a detailed understanding of background radiation fields. Both reactor-correlated and naturally occurring background sources are potentially important, even at levels well below those of importance for typical activities. Here we describe a comprehensive series of background assessments at three high-power research reactors, including $\\gamma$-ray, neutron, and muon measurements. For each facility we describe the characteristics and identify the sources of the background fields encountered. The general understanding gained of background production mechanisms and their relationship to facility features will prove valuable for the planning of any sensitive measurement conducted therein.

  14. Search for radiative decays of cosmic background neutrino using cosmic infrared background energy spectrum

    International Nuclear Information System (INIS)

    We propose to search for the neutrino radiative decay by fitting a photon energy spectrum of the cosmic infrared background to a sum of the photon energy spectrum from the neutrino radiative decay and a continuum. By comparing the present cosmic infrared background energy spectrum observed by AKARI and Spitzer to the photon energy spectrum expected from neutrino radiative decay with a maximum likelihood method, we obtained a lifetime lower limit of 3.1x1012 to 3.8x1012 years at 95% confidence level for the third generation neutrino v3 in the v3 mass range between 50 and 150 meV/c2 under the present constraints by the neutrino oscillation measurements. In the left-right symmetric model, the minimum lifetime of v3 is predicted to be 1.5x1017 years for m3 of 50 meV/c2. We studied the feasibility of the observation of the neutrino radiative decay with a lifetime of 1.5x1017 years, by measuring a continuous energy spectrum of the cosmic infrared background. (author)

  15. Suppressing Background Radiation Using Poisson Principal Component Analysis

    CERN Document Server

    Tandon, P; Dubrawski, A; Labov, S; Nelson, K

    2016-01-01

    Performance of nuclear threat detection systems based on gamma-ray spectrometry often strongly depends on the ability to identify the part of measured signal that can be attributed to background radiation. We have successfully applied a method based on Principal Component Analysis (PCA) to obtain a compact null-space model of background spectra using PCA projection residuals to derive a source detection score. We have shown the method's utility in a threat detection system using mobile spectrometers in urban scenes (Tandon et al 2012). While it is commonly assumed that measured photon counts follow a Poisson process, standard PCA makes a Gaussian assumption about the data distribution, which may be a poor approximation when photon counts are low. This paper studies whether and in what conditions PCA with a Poisson-based loss function (Poisson PCA) can outperform standard Gaussian PCA in modeling background radiation to enable more sensitive and specific nuclear threat detection.

  16. Alternative application for the radiation background in the development of the atlas database of atmospheric radiation

    CERN Document Server

    De la Hoz, Ivan Arturo Morales

    2014-01-01

    Nowadays radiation is one of the variables to be considered in the environmental forecasting and it is meaningful in the increase of global warming, together greenhouse effect. The radiation considered by the meteorological organizations depends on the World Radiometric Reference (WRR), the World Standard Group (WSG), addressed by the World Meteorological Organization (WMO). This work is based on the cosmic microwave background, as a variable to be estimated in order to get information about the incident radiation in the Earth's atmosphere, as a valuable and meaningful contribution in the building of the radiation atlas by the (UPME) and (IDEAM). Due to the fact that the variables considered are ultraviolet and infrared radiation, ozone column, direct radiation and diffuse radiation, the last two get the global radiation, and are the only ones to be evaluated by the national meteorological organizations in the country. The study of the cosmic background radiation as a research project will provide data which ...

  17. The Cosmic Microwave Background Radiation and its Polarization

    Science.gov (United States)

    Wollack, Edward

    2016-03-01

    The cosmic microwave background (CMB) radiation and its faint polarization have provided a unique means to constrain the physical state of the early Universe. Continued advances in instrumentation, observation, and analysis have revealed polarized radiation signatures associated with gravitational lensing and have heightened the prospects for using precision polarimetry to experimentally confront the inflationary paradigm. Characterization of this relic radiation field has the power to constrain or reveal the detailed properties of astroparticle species and long wave gravitational radiation. On going and planned CMB polarization efforts from the ground, balloon, and space borne platforms will be briefly surveyed. Recent community activities by the Inflation Probe Science Interest Group (IPSIG) will also be summarized. NASA PCOS mini-symposium (invited IPSIG talk).

  18. Radiative feedback from an early X-ray background

    CERN Document Server

    Glover, S C O; Glover, Simon C.O.; Brand, Peter W.J.L.

    2003-01-01

    The first generation of stars (commonly known as population III) are expected to form in low-mass protogalaxies in which molecular hydrogen is the dominant coolant. Radiation from these stars will rapidly build up an extragalactic ultraviolet background capable of photodissociating H2, and it is widely believed that this background will suppress further star formation in low-mass systems. However, star formation will also produce an extragalactic X-ray background. This X-ray background, by increasing the fractional ionization of protogalactic gas, promotes H2 formation and reduces the effectiveness of ultraviolet feedback. In this paper, we examine which of these backgrounds has the dominant effect. Using a simple model for the growth of the UV and X-ray backgrounds, together with a detailed one-dimensional model of protogalactic chemical evolution, we examine the effects of the X-ray backgrounds produced by a number of likely source models. We show that in several cases, the resulting X-ray background is str...

  19. Wormhole solution of BD theory in an anisotropic radiation background

    Directory of Open Access Journals (Sweden)

    B. Nasre Esfahani

    2001-06-01

    Full Text Available   Time-dependent wormhole solution of the BD theory in an anisotropic radiation background is presented. It is also found that the BD scalar field depends only on time. This time dependency is in power-law form. It is shown that the wormhole geometry is valid for ω ≥ -3/2, and for any arbitrary positive values of . The GR limit of our solution is obtained for ω=0 , not for ω→∞ . Though the BD field can be non-exotic, the background material is entirely exotic.

  20. Nature of the Background Ultraviolet Radiation Field at High Redshifts

    Indian Academy of Sciences (India)

    Archana Samantaray; Pushpa Khare

    2000-06-01

    We have tried to determine the flux of the ultraviolet background radiation field from the column density ratios of various ions in several absorption systems observed in the spectra of QSOs. We find that in most cases the flux is considerably higher than what has been estimated to be contributed by the AGNs. The excess flux could originate locally in hot stars. In a few cases we have been able to show that such galactic flux can only contribute a part of the total required flux. The results suggest that the background gets a significant contribution from an unseen QSO population.

  1. Backgrounds of computer-assisted treatment planning in radiation therapy

    International Nuclear Information System (INIS)

    Interaction of ionising radiation and living materials causes biological damage of tempory or permanent nature. In radiation therapy this phenomenon is used in a controlled fashion in order to stop the proliferation of malignant cells, while at the same time limiting the permanent damage to healthy tissues and organs to at least tolerable levels. Because of the often relatively small differences in response of malignant growths and normal tissues, the margins between tolerable and intolerable are so small that the greatest precision in treatment planning and execution is required. The nature of this treatment agent implies that the radiation therapist has to rely very much on instrumentally obtained and processed information, in all phases of this medical activities around the patient. In this paper a description is given of the backgrounds of computer-assisted methods which have enabled modern individualised and optimised planning for therapy with high energy X- and gamma beams. (orig.)

  2. CERN-derived analysis of lunar radiation backgrounds

    Science.gov (United States)

    Wilson, Thomas L.; Svoboda, Robert

    1993-01-01

    The Moon produces radiation which background-limits scientific experiments there. Early analyses of these backgrounds have either failed to take into consideration the effect of charm in particle physics (because they pre-dated its discovery), or have used branching ratios which are no longer strictly valid (due to new accelerator data). We are presently investigating an analytical program for deriving muon and neutrino spectra generated by the Moon, converting an existing CERN computer program known as GEANT which does the same for the Earth. In so doing, this will (1) determine an accurate prompt neutrino spectrum produced by the lunar surface; (2) determine the lunar subsurface particle flux; (3) determine the consequence of charm production physics upon the lunar background radiation environment; and (4) provide an analytical tool for the NASA astrophysics community with which to begin an assessment of the Moon as a scientific laboratory versus its particle radiation environment. This will be done on a recurring basis with the latest experimental results of the particle data groups at Earth-based high-energy accelerators, in particular with the latest branching ratios for charmed meson decay. This will be accomplished for the first time as a full 3-dimensional simulation.

  3. Vertebrate radiations of the Jehol Biota and their environmental background

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhonghe

    2004-01-01

    @@ Significant progress has been made in recent years in the studies of various groups of the Jehol Biota, particularly concerning the origin of birds and their flight as well as the evolution of Early Cretaceous birds, dinosaurs, mammals, insects and flowering plants[1-5]. As a result, the Jehol Biota has become well known to both the scientific community and the public. The studies on the Jehol Biota also revealed the patterns and processes of the evolutionary radiations of many major groups of Early Cretaceous animals and plants, such as the earliest known radiation of angiosperms and birds, early differentiation of mammals and many Cretaceous dinosaurian groups. Notably, the radiations of the Jehol vertebrates share some similar patterns attributable to the particular environmental background. For instance, the Jehol vertebrate radiations are highlighted by the presence of abundant arboreal adaptations and herbivorous forms, thus closely linked to the forest environments. In addition, the differentiation of habitats and diets is also characteristic of the evolutionary radiations of pterosaurs, dinosaurs, birds and mammals in the Jehol Biota.

  4. Geometry of manifolds with area metric: Multi-metric backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Schuller, Frederic P. [Perimeter Institute for Theoretical Physics, 31 Caroline Street N, Waterloo N2L 2Y5 (Canada) and Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A. Postal 70-543, Mexico D.F. 04510 (Mexico)]. E-mail: fschuller@perimeterinstitute.ca; Wohlfarth, Mattias N.R. [II. Institut fuer Theoretische Physik, Universitaet Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany)]. E-mail: mattias.wohlfarth@desy.de

    2006-07-24

    We construct the differential geometry of smooth manifolds equipped with an algebraic curvature map acting as an area measure. Area metric geometry provides a spacetime structure suitable for the discussion of gauge theories and strings, and is considerably more general than Lorentzian geometry. Our construction of geometrically relevant objects, such as an area metric compatible connection and derived tensors, makes essential use of a decomposition theorem due to Gilkey, whereby we generate the area metric from a finite collection of metrics. Employing curvature invariants for multi-metric backgrounds we devise a class of gravity theories with inherently stringy character, and discuss gauge matter actions.

  5. Cosmic Rays Induced Background Radiation on Board of Commercial Flights

    CERN Document Server

    Pinilla, S; Núñez, L A

    2015-01-01

    The aim of this work is to determine the total integrated flux of cosmic radiation which a commercial aircraft is exposed to along specific flight trajectories. To study the radiation background during a flight and its modulation by effects such as altitude, latitude, exposure time and transient magnetospheric events, we perform simulations based on Magnetocosmics and CORSIKA codes, the former designed to calculate the geomagnetic effects on cosmic rays propagation and the latter allows us to simulate the development of extended air showers in the atmosphere. In this first work, by considering the total flux of cosmic rays from 5 GeV to 1 PeV, we obtained the expected integrated flux of secondary particles on board of a commercial airplane during the Bogot\\'a-Buenos Aires trip by point-to-point numerical integration.

  6. On the radiative and thermodynamic properties of the Cosmic Microwave Background radiation using COBE FIRAS instrument data

    CERN Document Server

    Fisenko, Anatoliy I

    2014-01-01

    Use formulas to describe the monopole and dipole spectra of the Cosmic Microwave Background (CMB) radiation, the exact expressions for the temperature dependences of the radiative and thermodynamic functions, such as the total radiation power per unit area, total energy density, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume, pressure, enthalpy density, and internal energy density in the finite range of frequencies are obtained. Since the dependence of temperature upon the redshift z is known, the obtained expressions can be simply presented in z representation. Utilizing experimental data for the monopole and dipole spectra measured by the COBE FIRAS instrument in the 60 - 600 GHz frequency interval at the temperature T = 2.728 K, the values of the radiative and thermodynamic functions, as well as the radiation density constant a and the Stefan-Boltzmann constant are calculated. In the case of the dipole spectrum, the constants a and the Stefan-Bol...

  7. Large-Angular-Scale Anisotropy in the Cosmic Background Radiation

    Science.gov (United States)

    Gorenstein, M. V.; Smoot, G. F.

    1980-05-01

    We report the results of an extended series of airborne measurements of large-angular-scale anisotropy in the 3 K cosmic background radiation. Observations were carried out with a dual-antenna microwave radiometer operating at 33 GHz (.089 cm wavelength) flown on board a U-2 aircraft to 20 km altitude. In eleven flights, between December 1976 and May 1978, the radiometer measured differential intensity between pairs of directions distributed over most of the northern hemisphere with an rms sensitivity of 47 mK Hz{sup 1�}. The measurements how clear evidence of anisotropy that is readily interpreted as due to the solar motion relative to the sources of the radiation. The anisotropy is well fit by a first order spherical harmonic of amplitude 360{+ or -}50km sec{sup -1} toward the direction 11.2{+ or -}0.5 hours of right ascension and 19 {+ or -}8 degrees declination. A simultaneous fit to a combined hypotheses of dipole and quadrupole angular distributions places a 1 mK limit on the amplitude of most components of quadrupole anisotropy with 90% confidence. Additional analysis places a 0.5 mK limit on uncorrelated fluctuations (sky-roughness) in the 3 K background on an angular scale of the antenna beam width, about 7 degrees.

  8. Correlation between regional oncological mortality and natural radiation background in the CSR

    International Nuclear Information System (INIS)

    On the basis of published geological data (maps) an attempt was made to correlate the regional distribution of oncological mortality with the dose rate of the natural radiation background in the Czech Socialist Republic. No relationship was observed between the two parameters in the whole area of the CSR; for districts with an increased dose rate of the background or with high mortality the statistical relationship proved an inverse relationship: the higher the background dose rate the lower the oncological mortality and vice versa. (author). 3 figs., 1 tab., 22 refs

  9. Distribution of uranium, thorium and some stable trace and toxic elements in human hair and nails in Niška Banja Town, a high natural background radiation area of Serbia (Balkan Region, South-East Europe).

    Science.gov (United States)

    Sahoo, S K; Žunić, Z S; Kritsananuwat, R; Zagrodzki, P; Bossew, P; Veselinovic, N; Mishra, S; Yonehara, H; Tokonami, S

    2015-07-01

    Human hair and nails can be considered as bio-indicators of the public exposure to certain natural radionuclides and other toxic metals over a long period of months or even years. The level of elements in hair and nails usually reflect their levels in other tissues of body. Niška Banja, a spa town located in southern Serbia, with locally high natural background radiation was selected for the study. To assess public exposure to the trace elements, hair and nail samples were collected and analyzed. The concentrations of uranium, thorium and some trace and toxic elements (Mn, Ni, Cu, Sr, Cd, and Cs) were determined using inductively coupled plasma mass spectrometry (ICP-MS). U and Th concentrations in hair varied from 0.0002 to 0.0771 μg/g and from 0.0002 to 0.0276 μg/g, respectively. The concentrations in nails varied from 0.0025 to 0.0447 μg/g and from 0.0023 to 0.0564 μg/g for U and Th, respectively. We found significant correlations between some elements in hair and nails. Also indications of spatial clustering of high values could be found. However, this phenomenon as well as the large variations in concentrations of heavy metals in hair and nail could not be explained. As hypotheses, we propose possible exposure pathways which may explain the findings, but the current data does not allow testing them.

  10. Distribution of uranium, thorium and some stable trace and toxic elements in human hair and nails in Niška Banja Town, a high natural background radiation area of Serbia (Balkan Region, South-East Europe).

    Science.gov (United States)

    Sahoo, S K; Žunić, Z S; Kritsananuwat, R; Zagrodzki, P; Bossew, P; Veselinovic, N; Mishra, S; Yonehara, H; Tokonami, S

    2015-07-01

    Human hair and nails can be considered as bio-indicators of the public exposure to certain natural radionuclides and other toxic metals over a long period of months or even years. The level of elements in hair and nails usually reflect their levels in other tissues of body. Niška Banja, a spa town located in southern Serbia, with locally high natural background radiation was selected for the study. To assess public exposure to the trace elements, hair and nail samples were collected and analyzed. The concentrations of uranium, thorium and some trace and toxic elements (Mn, Ni, Cu, Sr, Cd, and Cs) were determined using inductively coupled plasma mass spectrometry (ICP-MS). U and Th concentrations in hair varied from 0.0002 to 0.0771 μg/g and from 0.0002 to 0.0276 μg/g, respectively. The concentrations in nails varied from 0.0025 to 0.0447 μg/g and from 0.0023 to 0.0564 μg/g for U and Th, respectively. We found significant correlations between some elements in hair and nails. Also indications of spatial clustering of high values could be found. However, this phenomenon as well as the large variations in concentrations of heavy metals in hair and nail could not be explained. As hypotheses, we propose possible exposure pathways which may explain the findings, but the current data does not allow testing them. PMID:25875006

  11. Biological consequences of increased natural radiation background for Microtus oeconomus Pall. populations

    Energy Technology Data Exchange (ETDEWEB)

    Kudyasheva, Alevtina G. [Radioecology Department, Institute of Biology, Komi Scientific Center, Ural Division RAS, 28 Kommunisticheskaya ul., Syktyvkar 167982, Komi Republic (Russian Federation); Shishkina, Ludmila N. [Emanuel Institute of Biochemical Physics RAS, Kosygina 4, Moscow 119991 (Russian Federation); Shevchenko, Oksana G. [Radioecology Department, Institute of Biology, Komi Scientific Center, Ural Division RAS, 28 Kommunisticheskaya ul., Syktyvkar 167982, Komi Republic (Russian Federation)], E-mail: shevchenko@ib.komisc.ru; Bashlykova, Ludmila A.; Zagorskaya, Nadezhda G. [Radioecology Department, Institute of Biology, Komi Scientific Center, Ural Division RAS, 28 Kommunisticheskaya ul., Syktyvkar 167982, Komi Republic (Russian Federation)

    2007-09-15

    The results of long-term investigations (1981-1999) on the state of Microtus oeconomus Pall. (tundra vole) population, living under the increased natural radiation background for a long time (for more than 100 generations), are presented. Population density dynamics, morphophysiological parameters, state of the lipid peroxidation regulatory system in different tissues and the cytogenetic effects in bone marrow cells of animals have been analyzed. It is shown that tundra voles from the studied radioactively contaminated areas differ from those on natural radiation background area for the parameters measured. The results of this long-term investigation show that qualitatively new sub-populations of tundra vole on these areas have evolved, which are able to survive in radioactively contaminated environment.

  12. Fruits Program Area Research Planning and Prioritization: Background Analysis

    OpenAIRE

    Pabuayon, Isabelita

    2000-01-01

    This study addresses the Fruits Program Area research allocation concerns. It provides a background analysis focusing on the fruits industry profile, domestic and export potentials, supply constraints, role of public and private sector R&D, review of past agricultural research, technologies generated by the R&D program, constraints to and consequences of technology adoption, and the strengths and weaknesses in the institutional structure of research and extension linkage. Additionally, it pro...

  13. Digital Retinal Images: Background and Damaged Areas Segmentation

    Directory of Open Access Journals (Sweden)

    Eman A. Gani

    2014-07-01

    Full Text Available Digital retinal images are more appropriate for automatic screening of diabetic retinopathy systems. Unfortunately, a significant percentage of these images are poor quality that hiders further analysis due to many factors (such as patient movement, inadequate or non-uniform illumination, acquisition angle and retinal pigmentation. The retinal images of poor quality need to be enhanced before the extraction of features and abnormalities. So, the segmentation of retinal image is essential for this purpose, the segmentation is employed to smooth and strengthen image by separating the background and damaged areas from the overall image thus resulting in retinal image enhancement and less processing time. In this paper, methods for segmenting colored retinal image are proposed to improve the quality of retinal image diagnosis. The methods generates two segmentation masks; i.e., background segmentation mask for extracting the background area and poor quality mask for removing the noisy areas from retinal image. The standard retinal image databases DIARETDB0, DIARETDB1, STARE, DRIVE and some images obtained from ophthalmologists have been used to test the validation of the proposed segmentation technique. Experimental results indicate the introduced methods are effective and can lead to high segmentation accuracy

  14. Cosmic Background Radiation and `ether-drift' experiments

    CERN Document Server

    Consoli, M; Rapisarda, A

    2016-01-01

    `Ether-drift' experiments have played a crucial role for the origin of relativity. Though, a recent re-analysis shows that those original measurements where light was still propagating in gaseous systems, differently from the modern experiments in vacuum and in solid dielectrics, indicate a small universal anisotropy which is naturally interpreted in terms of a non-local thermal gradient. We argue that this could possibly be the effect, on weakly bound gaseous matter, of the temperature gradient due to the Earth's motion within the Cosmic Background Radiation (CBR). Therefore, a check with modern laser interferometers is needed to reproduce the conditions of those early measurements with today's much greater accuracy. We emphasize that an unambiguous confirmation of our interpretation would have far reaching consequences. For instance, it would also imply that all physical systems on the moving Earth are exposed to a tiny energy flow, an effect that, in principle, could induce forms of self-organization in ma...

  15. Far Infrared Spectrometry of the Cosmic Background Radiation

    Science.gov (United States)

    Mather, J. C.

    1974-01-01

    I describe two experiments to measure the cosmic background radiation near 1 mm wavelength. The first was a ground-based search for spectral lines, made with a Fabry-Perot interferometer and an InSb detector. The second is a measurement of the spectrum from 3 to 18 cm{sup -1}, made with a balloon-borne Fourier transform spectrometer. It is a polarizing Michelson interferometer, cooled in liquid helium, and operated with a germanium bolometer. I give the theory of operation, construction details, and experimental results. The first experiment was successfully completed but the second suffered equipment malfunction on its first flight. I describe the theory of Fourier transformations and give a new understanding of convolutional phase correction computations. I discuss for infrared bolometer calibration procedures, and tabulate test results on nine detectors. I describe methods of improving bolometer sensitivity with immersion optics and with conductive film blackening.

  16. Characterization of the radiation background at the Spallation Neutron Source

    Science.gov (United States)

    DiJulio, Douglas D.; Cherkashyna, Nataliia; Scherzinger, Julius; Khaplanov, Anton; Pfeiffer, Dorothea; Cooper-Jensen, Carsten P.; Fissum, Kevin G.; Kanaki, Kalliopi; Kirstein, Oliver; Ehlers, Georg; Gallmeier, Franz X.; Hornbach, Donald E.; Iverson, Erik B.; Newby, Robert J.; Hall-Wilton, Richard J.; Bentley, Phillip M.

    2016-09-01

    We present a survey of the radiation background at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory, TN, USA during routine daily operation. A broad range of detectors was used to characterize primarily the neutron and photon fields throughout the facility. These include a WENDI-2 extended range dosimeter, a thermoscientific NRD, an Arktis 4He detector, and a standard NaI photon detector. The information gathered from the detectors was used to map out the neutron dose rates throughout the facility and also the neutron dose rate and flux profiles of several different beamlines. The survey provides detailed information useful for developing future shielding concepts at spallation neutron sources, such as the European Spallation Source (ESS), currently under construction in Lund, Sweden.

  17. Characteristic angular scales in cosmic microwave background radiation

    International Nuclear Information System (INIS)

    We investigate the stochasticity in temperature fluctuations in the cosmic microwave background (CMB) radiation data from the Wilkinson Microwave Anisotropy Probe. We show that the angular fluctuation of the temperature is a Markov process with a Markov angular scale, Markov 1.01-0.07+0.09. We characterize the complexity of the CMB fluctuations by means of a Fokker-Planck or Langevin equation and measure the associated Kramers-Moyal coefficients for the fluctuating temperature field T(n-circumflex) and its increment, ΔT = T(n-circumflex1) - T(n-circumflex2). Through this method we show that temperature fluctuations in the CMB have fat tails compared to a Gaussian distribution. (author)

  18. Natural background radiation induces cytogenetic radioadaptive response more effectively than occupational exposure in human peripheral blood lymphocytes

    International Nuclear Information System (INIS)

    Ramsar, a city in the north part of Iran, has the highest level of natural background radiation in the world. We compared induction of cytogenetic radioadaptive response by High Natural Background Radiation (HNBR) in Ramsar and X-Ray occupational exposure as inducing doses in human peripheral blood lymphocytes. 30 healthy control individuals, living in Ramsar but in ordinary background radiation areas (inducing dose = 0), 15 healthy individuals from Talesh Mahalleh, a region with extraordinary level of background radiation (max. inducing dose = 260 mGy/year) and 7 X-Ray radiographers working in Ramsar hospital located in normal natural background of ionising radiation (max. inducing dose = 20 mGy/year) were evaluated. Peripheral blood samples were prepared and exposed to challenge dose of 0 and 2 Gy. Lymphocytes were scored using analysis of metaphase, for the presence of chromosomal aberrations (simple deletion, dicentrics and rings). An adaptive response was observed in HNBR and radiation workers groups in comparison with sham controls. Also, compared with occupationally exposed group a significant marked increase in adaptive response was observed in HNBR group. These findings indicate that both natural background radiation and occupational exposure could induce cytogenetic radioadaptive response and it is more significant regarding to natural background ionising radiation. (author)

  19. A Cosmic Microwave Background Radiation Polarimeter Using Superconducting Bearings

    CERN Document Server

    Hanany, S; Johnson, B; Jones, T; Hull, J R; Ma, K B

    2003-01-01

    Measurements of the polarization of the cosmic microwave background (CMB) radiation are expected to significantly increase our understanding of the early universe. We present a design for a CMB polarimeter in which a cryogenically cooled half wave plate rotates by means of a high-temperature superconducting (HTS) bearing. The design is optimized for implementation in MAXIPOL, a balloon-borne CMB polarimeter. A prototype bearing, consisting of commercially available ring-shaped permanent magnet and an array of YBCO bulk HTS material, has been constructed. We measured the coefficient of friction as a function of several parameters including temperature between 15 and 80 K, rotation frequency between 0.3 and 3.5 Hz, levitation distance between 6 and 10 mm, and ambient pressure between 10^{-7} and 1 torr. The low rotational drag of the HTS bearing allows rotations for long periods of time with minimal input power and negligible wear and tear thus making this technology suitable for a future satellite mission.

  20. Evaluation of the natural background radiation in City Sopron

    Energy Technology Data Exchange (ETDEWEB)

    Spaits, T. [West Hungary Univ., Institute of Forestry Mechanics (Hungary); Divos, F. [West Hungary Univ., National Radiation Control System - Sopron Unit (Hungary); Kavasi, N. [Veszprem Univ., Dept. of Radiochemistry (Hungary); Boka, Z. [West Hungary Univ., Dept. of Geodetics and Remote Sensing (Hungary)

    2006-07-01

    In the Postgraduate School of the Faculty of Forestry of the University of West Hungary a project with the topic Research of natural radioactive isotopes in our built and natural environs is being run. Preparing this map is an organic part of this PhD research. The measurements are being made in Sopron city and in its next surroundings, trying to estimate, which dose of radiation a citizen of Sopron is exposed, according to his age and lifestyle. The measurements completely cover the built-up area of Sopron, moreover they exceed the confines, so thus they provide information about the natural areas in the vicinity of the city. In figures, the detection carried out in an area of 24 square kilometres, working with a grid mesh of 200 metres. A sodium-iodide detector was used. We have faced several anomalies while mapping. These are the following: On Main Square (Foter), Ursulin Square (Orsolya ter), Paulites Square (Palosok tere, where a higher dose can be measured, due to granite cobbles, used to cover the pavements of the squares and streets. This was confirmed by the gamma spectrometric examination of the granite stones. In these areas, a triple of the mean dose-rate of 70-90 n Sv/h in Sopron was detected. The highest values of 400 n Sv/h were detected in the cinder-covered car-park of the paint store in Koszegi Street. The total gamma activity concentration of the cinder used in the car-park was nearly 2000 Bq/kg. A triple to a quadruple of the natural level was detected in the vicinity of the chimney of the former thermal power plant and the brick factory. The detection was carried out in four directions with raising range starting by the chimneys, which has spectacularly shown, that the sedimentation of the aerosols can be tracked is a function of distance. The measurements have also shown, that there is a significant difference between dose-levels of the natural areas beyond the eastern and western edge of the city, which can be explained with the different

  1. Cosmic background radiation spectral distortion and radiative decays of relic neutral particles

    International Nuclear Information System (INIS)

    The recently observed excess of photons on a short wavelength side of the peak of a cosmic background radiation spectrum can be described by radiative decays of relic neutral particles. The lifetime and mass of a decaying particle must satisfy the following conditions: 2x109 s14 s, 0.4 eV-9-8x10-8) μb, and the interaction of new particles with the usual matter must be rather strong. The generalization of the standard SU(3)xSU(2)xU(1) model is presented which includes new particles with the desired properties. 18 refs.; 3 figs.; 2 tabs

  2. Natural background radiation and estimation of gonadal dose rate of population of Chittagong region

    Energy Technology Data Exchange (ETDEWEB)

    Mostofa, M.N.; Ahmed, J.U. (Chittagong Univ. (Bangladesh). Dept. of Physics); Ahmed, R.; Ishaque, A.M. (Nuclear Medicine Center, Chittagong (Bangladesh)); Ahmed, K. (Institute of Nuclear Medicine, Dacca (Bangladesh))

    1981-07-01

    A survey was made on the background radiation to estimate the gonadal dose rate in the district of Chittagong from the year 1978 to 80. This was done with the help of a calibrated Nuclear Chicago transistorized survey meter. The measurements were made in different types of dwellings and occupational buildings constructed with wood, straw/bamboo, tin/bamboo, tin/brick and single and multistoried buildings of brick and concrete. For measurement of outdoor radiation the investigating areas taken were the roads, fields and the Karnafuly river. The variation in the population dose rate as well as gonadal dose rate were observed in different types of dwellings and occupational buildings including outdoors. The average population dose rate including cosmic ray intensity was found to be 172.41+-8.61 mrad/year. Thus, the annual gonadal dose rate due to gamma radiation was found to be 137.92+-6.89 mrad/year.

  3. 广东高本底地区人群氧化损伤及抗氧化水平调查%The effects of low dose radiation on the levels of oxidative damage and antioxidant in population of high background radiation area of Guangdong

    Institute of Scientific and Technical Information of China (English)

    陈慧峰; 郭强之; 刘明; 耿继武; 苏世标

    2015-01-01

    目的 探讨长期连续天然放射性照射对人群氧化损伤及抗氧化水平的影响.方法 选择广东天然放射性高本底辐射地区(HBRA)48名男性居民为研究对象,选择恩平市某镇(CA)相匹配的48名男性居民为对照人群.采集2组人群外周静脉血并分离血浆,采用酶联免疫吸附试验(ELISA),测定血浆中DNA氧化损伤指标8-羟基脱氧鸟苷(8-OHdG)和抗氧化指标硫氧还蛋白还原酶(TrxR)的表达水平.结果 与对照组相比,高本底地区人群外周血血浆中DNA氧化损伤指标8-OHdG表达水平由(315.39±100.59) ng/ml降低至(272.64±96.85) ng/ml,抗氧化指标TrxR表达水平由(0.467±0.056) ng/ml升高至(0.496±0.044) ng/ml,两组间的差异均有统计学意义(t=2.121、-2.823,P<0.05).多元线性回归分析结果显示,在排除年龄、饮酒、喝茶、吸烟、接受医疗照射、生活应激事件等混杂因素的影响后,低剂量电离辐射个人累积剂量对8-OHdG和TrxR表达水平均有影响(t=-2.327、2.367,P<0.05).结论 长期接触低剂量电离辐射可降低人群氧化损伤水平,增强机体抗氧化水平.%Objective To investigate the effects of low dose radiation on the level of oxidative damage and antioxidant in population of high background radiation area of Guangdong.Methods A total of 48 male residents who lived in high background radiation area(HBRA) of Guangdong province and 48 male residents who lived in neighboring Enping control area were chosen as the objectives and control respectively.The peripheral venous blood of two groups was collected,and then the levels of 8-OHdG and TrxR were determined by enzyme linked immunosorbent assay (ELISA).Results Compared with the CA group [(315.39 ± 100.59) ng/ml],the level of 8-OHdG [(272.64 ± 96.85) ng/ml] decreased significantly in HBRA (t =2.121,P <0.05).Compared with the CA group [(0.467 ±0.056) ng/ml],the level of TrxR [(0.496 ± 0.044) ng/ml] increased significantly in HBRA (t =-2.823,P

  4. Calculating the background radiation in the vicinity of the beam catchers of the ELBE radiation source

    International Nuclear Information System (INIS)

    The ELBE radiation sources comprises beam catchers in the experimenting sites which absorb the primary electron beam as well as the generated secondary radiation. The beam catcher consists of an ultrapure graphite absorber enclosed in a water-cooled stainless steel shell. Background radiation is shielded by iron, lead and heavy concrete. The beam parameters and the position of the beam catchers differ between experimenting sites. In order to determine the dose dependence of photon and neutron fluence and the dose equivalent at the cooling shell of the beam catcher, simulations were carried out using the FLUKA code. Radiation energies of 20 MeV and 50 MeV and electron fluxes of 1 mA were considered. The spatial and energetic distributions of the dose rate equivalent provide a basis for dimensioning of the radiation shields. The calculated distributions of the energy dose rate in the beam catcher serve as a basis for assessing thermal loads on materials and for designing the cooling system. (orig.)

  5. High Precision Cosmology with the Cosmic Background Radiation

    Science.gov (United States)

    Farhang, Marzieh

    In this thesis we investigate the two cosmic epochs of inflation and recombination, through their imprints on the temperature and polarization anisotropies of the cosmic microwave background radiation. To probe the early universe we develop a map-based maximum-likelihood estimator to measure the amplitude of inflation-induced gravity waves, parametrized by r, from the cosmic microwave background (CMB) polarization maps. Being optimal by construction, the estimator avoids E-B mixing, a possible source of contamination in the tiny B-mode detection, the target of many current and near future CMB experiments. We explore the leakage from the E- to the B-mode of polarization by using this estimator to study the linear response of the B-mode signal at different scales to variations in the E- mode power. Similarly, for various observational cases, we probe the dependence of r measurement on the signal from different scales of E and B polarization. The estimator is used to make forecasts for Spider-like and Planck-like experimental specifications and to investigate the sky-coverage optimization of the Spider-like case. We compare the forecast errors on r to the results from a similar multipole-based estimator which, by ignoring the mode-mixing, sets a lower limit on the achievable error on r. We find that an experiment with Spider-like specifications with fsky ˜ 0:02--0:2 could place a 2sigma r ≈ 0:014 bound (˜ 95% CL), which rises to 0:02 with an ℓ-dependent foreground residual left over from an assumed efficient component separation. For the Planck-like survey, a Galaxy-masked ( fsky = 0:75) sky would give 2sigmar ≈ 0:015, rising to ≈ 0:05 with the foreground residuals. We also use a novel information-based framework to compare how different generations of CMB experiments reveal information about the early universe, through their measurements of r. We also probe the epoch of recombination by investigating possible fluctuations in the free electron fraction Xe

  6. Experiences from studies of leukemia, background radiation and other factors

    International Nuclear Information System (INIS)

    Ionizing radiation seems to induce myeloid leukemia of the acute and chronic type, and also acute lymphatic leukemia but not chronic lymphatic leukemia. The effects of low dose radiation in this context as well as for other malignancies, are currently a matter of controversy. On the basis of literary data the carcinogenic effect, and in particular the leukemia inducing effect, of low dose irradiation is discussed. It is concluded that only further studies in the low dose range can create a definite basis for a risk assessment with regard to ionizing radiation. The risk estimates obtained may not necessarily reflect an initiating effect of ionizing radiation, but could involve late stage effects exerted over time. However, such possibilities have so far achieved little attention

  7. Telomere length in human adults and high level natural background radiation.

    Directory of Open Access Journals (Sweden)

    Birajalaxmi Das

    Full Text Available BACKGROUND: Telomere length is considered as a biomarker of aging, stress, cancer. It has been associated with many chronic diseases such as hypertension and diabetes. Although, telomere shortening due to ionizing radiation has been reported in vitro, no in vivo data is available on natural background radiation and its effect on telomere length. METHODOLOGY/PRINCIPAL FINDINGS: The present investigation is an attempt to determine the telomere length among human adults residing in high level natural radiation areas (HLNRA and the adjacent normal level radiation areas (NLNRA of Kerala coast in Southwest India. Genomic DNA was isolated from the peripheral blood mononuclear cells of 310 individuals (HLNRA: N = 233 and NLNRA: N = 77. Telomere length was determined using real time q-PCR. Both telomere (T and single copy gene (S specific primers were used to calculate the relative T/S and expressed as the relative telomere length. The telomere length was determined to be 1.22+/-0.15, 1.12+/-0.15, 1.08+/-0.08, 1.12+/-0.11, respectively, among the four dose groups (5.00 mGy per year, which did not show any dose response. The results suggested that the high level natural chronic radiation did not have significant effect on telomere length among young adult population living in HLNRA, which is indicative of better repair of telomeric ends. No significant difference in telomere length was observed between male and female individuals. In the present investigation, although the determination of telomere length was studied among the adults with an age group between 18 to 40 years (mean maternal age: 26.10+/-4.49, a negative correlation was observed with respect to age. However, inter-individual variation was (0.81-1.68 was clearly observed. CONCLUSIONS/SIGNIFICANCE: In this preliminary investigation, we conclude that elevated level of natural background radiation has no significant effect on telomere length among the adult population residing in HLNRAs of

  8. Reduction of radiation area project plan

    International Nuclear Information System (INIS)

    This plan deals with the overall reduction of outdoor surface radiation areas under Rockwell's jurisdiction. Four basic alternatives are identified which will reduce and/or stabilize radiation areas until long-term disposal decisions are made: (1) continued routine surveillance and maintenance; (2) reduction or elimination of effluent discharges; (3) improved site stabilization; and (4) site removal. The four major transport mechanisms at Hanford that are the primary forces for contamination spread are identified as wind, animal transport, concentration and dispersal by plants, and transport resulting from human activities

  9. Radiation Background and Attenuation Model Validation and Development

    Energy Technology Data Exchange (ETDEWEB)

    Peplow, Douglas E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Santiago, Claudio P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-08-05

    This report describes the initial results of a study being conducted as part of the Urban Search Planning Tool project. The study is comparing the Urban Scene Simulator (USS), a one-dimensional (1D) radiation transport model developed at LLNL, with the three-dimensional (3D) radiation transport model from ORNL using the MCNP, SCALE/ORIGEN and SCALE/MAVRIC simulation codes. In this study, we have analyzed the differences between the two approaches at every step, from source term representation, to estimating flux and detector count rates at a fixed distance from a simple surface (slab), and at points throughout more complex 3D scenes.

  10. Hawking's radiation in non-stationary rotating de Sitter background

    CERN Document Server

    Ibohal, Ng; 10.1007/s10509-011-0606-0

    2011-01-01

    Hawking's radiation effect of Klein-Gordon scalar field, Dirac particles and Maxwell's electromagnetic field in the non-stationary rotating de Sitter cosmological space-time is investigated by using a method of generalized tortoise co-ordinates transformation. The locations and the temperatures of the cosmological horizons of the non-stationary rotating de Sitter model are derived. It is found that the locations and the temperatures of the rotating cosmological model depend not only on the time but also on the angle. The stress-energy regularization techniques are applied to the two dimensional analog of the de Sitter metrics and the calculated stress-energy tensor contains the thermal radiation effect.

  11. Detecting a non-Gaussian stochastic background of gravitational radiation

    CERN Document Server

    Drasco, S; Drasco, Steve; Flanagan, Eanna E.

    2002-01-01

    We derive a detection method for a stochastic background of gravitational waves produced by events where the ratio of the average time between events to the average duration of an event is large. Such a signal would sound something like popcorn popping. Our derivation is based on the somewhat unrealistic assumption that the duration of an event is smaller than the detector time resolution.

  12. Detecting a non-Gaussian stochastic background of gravitational radiation

    OpenAIRE

    Drasco, Steve; Flanagan, Eanna E.

    2001-01-01

    We derive a detection method for a stochastic background of gravitational waves produced by events where the ratio of the average time between events to the average duration of an event is large. Such a signal would sound something like popcorn popping. Our derivation is based on the somewhat unrealistic assumption that the duration of an event is smaller than the detector time resolution.

  13. Dark energy and the cosmic microwave background radiation

    Science.gov (United States)

    Dodelson, S.; Knox, L.

    2000-01-01

    We find that current cosmic microwave background anisotropy data strongly constrain the mean spatial curvature of the Universe to be near zero, or, equivalently, the total energy density to be near critical-as predicted by inflation. This result is robust to editing of data sets, and variation of other cosmological parameters (totaling seven, including a cosmological constant). Other lines of argument indicate that the energy density of nonrelativistic matter is much less than critical. Together, these results are evidence, independent of supernovae data, for dark energy in the Universe.

  14. Mapping the exposure of the Brazilian population to natural background radiation - cosmic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Rochedo, Elaine R.R., E-mail: elaine@ird.gov.br [Instituto de Radioprotecao e Dosimetria (lRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Salles, Krause C.S.; Prado, Nadya M.C., E-mail: krausesalles@yahoo.com.br, E-mail: nadya@ime.ib.br [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    The main objective of this work is to statically and graphically describe the exposure of the Brazilian population to natural background radiation. in this stage, doses due to cosmic rays is being assessed based on sea level dose rates, corrected by latitude and altitude, according to the model recommended by UNSCEAR. In this work, the doses were estimated for ali Brazilian municipalities with more than 100.000 inhabitants. The 253 municipalities selected for this study include about 52% of the Brazilian population. Average dose rate was estimated to be about 50 n Sv/h with a variation coefficient of 31%. The estimated doses have shown a strong influence of altitude on dose rates, with a correlation coefficient of 0,998 for ao exponential fit. This result confirms previous studies that show a large effect of the altitude 00 exposure from cosmic radiation. Considering the same occupation and shielding conditions used by UNSCEAR as global averages, average annual dose was estimated to be 0,37 (0,24 - 0,76) mSv/y, very close to UNSCEAR worldwide average of 0,38 (0,3 - 1,0) mSv/y. (author)

  15. Fast shutter for low background radiation environments at SPR III

    International Nuclear Information System (INIS)

    A fast shutter system has been developed and used to isolate experiments from the radiation emitted after the main pulse of the Sandia Pulse Reactor, SPR 3. In about 15 ms the system moves a massive 20 kg shield in front of the beam port aperture in the facility shield wall. A second gravity-driven shutter is dropped into place in about 200 ms. The total attenuation achieved in the beam intensity is about a factor of one hundred. The shutter assembly was used, along with a sensitive detection system, to observe the gamma ray flux emitted by various materials activated by the neutron beam at levels nine orders of magnitude smaller than the gamma flux level at the target during the reactor pulse

  16. Effects of deprivation of background environmental radiation on cultured human cells

    International Nuclear Information System (INIS)

    In this paper we present results from an experiment aimed at investigating whether living cells are influenced by background ionizing radiation. Parallel human cell cultures were set-up in two separate laboratories and maintained for several months under identical conditions but for a 80 x different level of background ionizing radiation. Periodically, the cell cultures were monitored for the onset of divergences in biochemical behavior, using two distinct cellular biology assays, namely micronuclei induction and activity of enzymes implicated in the management of oxidative stress. To reveal any subtle modifications, responses were also amplified by subjecting cell cultures to acute stress induced by exposure to moderately high doses of ionizing radiation. Compared to reference radiation background conditions, cultures maintained in a reduced background radiation environment handled the consequences of acute stress with diminished efficacy.

  17. Self-amplifying Hawking radiation and its background: a numerical study

    CERN Document Server

    Steinhauer, Jeff

    2016-01-01

    We numerically study an analogue black hole with two horizons with similar parameters to a recent experiment. We find that the Hawking radiation exists on a background which contains a density oscillation, a zero-frequency ripple. The Hawking radiation evolves from spontaneous to self-amplifying, while the background ripple grows steadily with no qualitative change. It is seen that the self-amplifying Hawking radiation has a non-zero frequency. The background ripple appears even before the inner horizon is created, in contrast to predictions. This work is in agreement with the recent observation of self-amplifying Hawking radiation, and explains some of the features seen. In contrast to recent works, our study differentiates between the Hawking radiation observed, and the evolution of the background.

  18. How does radiative feedback from a UV background impact reionization?

    CERN Document Server

    Sobacchi, Emanuele

    2013-01-01

    An ionizing UV background (UVB) inhibits gas accretion and photo-evaporates gas from the shallow potential wells of small, dwarf galaxies. During cosmological reionization, this effect can result in negative feedback: suppressing star-formation inside HII regions, thus impeding their continued growth. It is difficult to model this process, given the enormous range of scales involved. We tackle this problem using a tiered approach: combining parameterized results from single-halo collapse simulations with large-scale models of reionization. In the resulting reionization models, the ionizing emissivity of galaxies depends on the local values of the reionization redshift and the UVB intensity. We present a physically-motivated analytic expression for the average minimum mass of star-forming galaxies, which can be readily used in modeling galaxy formation. We find that UVB feedback: (i) delays the end stages of reionization by less than 0.5 in redshift; (ii) results in a more uniform distribution of HII regions, ...

  19. Modeling Background Radiation in our Environment Using Geochemical Data

    Energy Technology Data Exchange (ETDEWEB)

    Malchow, Russell L.; Marsac, Kara [University of Nevada, Las Vegas; Burnley, Pamela [University of Nevada, Las Vegas; Hausrath, Elisabeth [Uniiversity of Nevada, Las Vegas; Haber, Daniel [University of Nevada, Las Vegas; Adcock, Christopher [University of Nevada, Las Vegas

    2015-02-01

    Radiation occurs naturally in bedrock and soil. Gamma rays are released from the decay of the radioactive isotopes K, U, and Th. Gamma rays observed at the surface come from the first 30 cm of rock and soil. The energy of gamma rays is specific to each isotope, allowing identification. For this research, data was collected from national databases, private companies, scientific literature, and field work. Data points were then evaluated for self-consistency. A model was created by converting concentrations of U, K, and Th for each rock and soil unit into a ground exposure rate using the following equation: D=1.32 K+ 0.548 U+ 0.272 Th. The first objective of this research was to compare the original Aerial Measurement System gamma ray survey to results produced by the model. The second objective was to improve the method and learn the constraints of the model. Future work will include sample data analysis from field work with a goal of improving the geochemical model.

  20. Assessment of background gamma radiation and determination of excess lifetime cancer risk in Sabzevar City, Iran in 2014

    Directory of Open Access Journals (Sweden)

    Akbar Eslami

    2016-01-01

    Full Text Available Background: Background gamma radiation levels vary in different locations and depended on many factors such as radiation properties of soil, building materials as well as construction types which human lives on it. People are always exposed to ionizing radiation, which could badly influence their health. The aim of this study was to evaluate the background gamma-ray dose rate and the estimated annual effective dose equivalent and determination of excess lifetime cancer risk in Sabzevar City, Iran. Methods: The aim of this cross-sectional study was to determine the dose rate of background gamma radiation in outdoor an indoor areas, 26 stations were selected using the map of the Sabzevar City. The amount of gamma radiation was measured at 4 months (September to January in 2014 year. The dosimeter used in this study was a survey meter, that is designed for monitoring radiation of x, gamma and beta rays. Results: The obtained results show that there are significant differences between the indoor and outdoor exposures (P> 0.05. We did not observe significant differences between the time of sampling and sampling locations, (P<0.05. The minimum and maximum values of dose rate were found 66±20 nSvh-1 and 198±28 nSvh-1. The annual effective dose for Sabzevar residents was estimated to be 0.85 mSv and also the amount of excess lifetime cancer risk was estimated 3.39×10-3. Conclusion: According to the results, the excess lifetime cancer risk and the annual effective dose for the Sabzavar City residents due to the background gamma radiation was higher than the global average (0.5 mSv. The epidemiological studies have been proposed to evaluate the risk of chronic diseases associated with natural radiation exposure among residents.

  1. The Cosmic Background Radiation circa ν2K

    Science.gov (United States)

    Bond, J. Richard; Pogosyan, Dmitry; Prunet, Simon

    We describe the implications of cosmic microwave background (CMB) observations and galaxy and cluster surveys of large scale structure (LSS) for theories of cosmic structure formation, especially emphasizing the recent Boomerang and Maxima CMB balloon experiments. The inflation-based cosmic structure formation paradigm we have been operating with for two decades has never been in better shape. Here we primarily focus on a simplified inflation parameter set, {ωb, ωcdm, Ωtot, ΩΛ, ns, τC, σ8}. Combining all of the current CMB+LSS data points to the remarkable conclusion that the local Hubble patch we can access has little mean curvature (Ωtot = 1.08 +/- 0.06) and the initial fluctuations were nearly scale invariant (ns = 1.03 +/- 0.08), both predictions of (non-baroque) inflation theory. The baryon density is found to be slightly larger than that preferred by independent Big Bang Nucleosynthesis estimates (ωb --- Ωbh2 = 0.030 +/- 0.005 cf. 0.019 +/- 0.002). The CDM density is in the expected range (ωcdm = 0.17+/-0.02). Even stranger is the CMB+LSS evidence that the density of the universe is dominated by unclustered energy akin to the cosmological constant (ΩΛ = 0.66 +/- 0.06), at the same level as that inferred from high redshift supernova observations. We also sketch the CMB+LSS implications for massive neutrinos.

  2. The Cosmic Background Radiation circa nu2K

    CERN Document Server

    Bond, J R; Prunet, S; Ade, P; Balbi, A; Bock, J J; Borrill, J; Boscaleri, A; Coble, K; Crill, B P; De Bernardis, P; Farese, P; Ferreira, P; Ganga, K; Giacometti, M; Hanany, S; Hivon, E; Hristov, V V; Iacoangeli, A; Jaffe, A; Lange, A; Lee, A; Martinis, L; Masi, S; Mauskopf, P D; Melchiorri, A; Montroy, T; Netterfield, C B; Oh, S; Pascale, E; Piacentini, F; Rabii, B; Rao, S; Richards, P; Romeo, G; Ruhl, J E; Scaramuzzi, F; Sforza, D M; Smoot, G F; Stompor, R; Winant, C; Wu, P

    2000-01-01

    We describe the implications of cosmic microwave background (CMB) observations and galaxy and cluster surveys of large scale structure (LSS) for theories of cosmic structure formation, especially emphasizing the recent Boomerang and Maxima CMB balloon experiments. The inflation-based cosmic structure formation paradigm we have been operating with for two decades has never been in better shape. Here we primarily focus on a simplified inflation parameter set, {omega_b,omega_{cdm},Omega_{tot}, Omega_\\Lambda,n_s,\\tau_C, \\sigma_8}. Combining all of the current CMB+LSS data points to the remarkable conclusion that the local Hubble patch we can access has little mean curvature (Omega_{tot}=1.08\\pm 0.06) and the initial fluctuations were nearly scale invariant (n_s=1.03\\pm 0.08), both predictions of (non-baroque) inflation theory. The baryon density is found to be slightly larger than that preferred by independent Big Bang Nucleosynthesis estimates (omega_b=0.030\\pm 0.005 cf. 0.019\\pm 0.002). The CDM density is in th...

  3. Real-time airborne gamma-ray background estimation using NASVD with MLE and radiation transport for calibration

    International Nuclear Information System (INIS)

    Helicopter-mounted gamma-ray detectors can provide law enforcement officials the means to quickly and accurately detect, identify, and locate radiological threats over a wide geographical area. The ability to accurately distinguish radiological threat-generated gamma-ray signatures from background gamma radiation in real time is essential in order to realize this potential. This problem is non-trivial, especially in urban environments for which the background may change very rapidly during flight. This exacerbates the challenge of estimating background due to the poor counting statistics inherent in real-time airborne gamma-ray spectroscopy measurements. To address this challenge, we have developed a new technique for real-time estimation of background gamma radiation from aerial measurements without the need for human analyst intervention. The method can be calibrated using radiation transport simulations along with data from previous flights over areas for which the isotopic composition need not be known. Over the examined measured and simulated data sets, the method generated accurate background estimates even in the presence of a strong, 60Co source. The potential to track large and abrupt changes in background spectral shape and magnitude was demonstrated. The method can be implemented fairly easily in most modern computing languages and environments

  4. Real-time airborne gamma-ray background estimation using NASVD with MLE and radiation transport for calibration

    Science.gov (United States)

    Kulisek, J. A.; Schweppe, J. E.; Stave, S. C.; Bernacki, B. E.; Jordan, D. V.; Stewart, T. N.; Seifert, C. E.; Kernan, W. J.

    2015-06-01

    Helicopter-mounted gamma-ray detectors can provide law enforcement officials the means to quickly and accurately detect, identify, and locate radiological threats over a wide geographical area. The ability to accurately distinguish radiological threat-generated gamma-ray signatures from background gamma radiation in real time is essential in order to realize this potential. This problem is non-trivial, especially in urban environments for which the background may change very rapidly during flight. This exacerbates the challenge of estimating background due to the poor counting statistics inherent in real-time airborne gamma-ray spectroscopy measurements. To address this challenge, we have developed a new technique for real-time estimation of background gamma radiation from aerial measurements without the need for human analyst intervention. The method can be calibrated using radiation transport simulations along with data from previous flights over areas for which the isotopic composition need not be known. Over the examined measured and simulated data sets, the method generated accurate background estimates even in the presence of a strong, 60Co source. The potential to track large and abrupt changes in background spectral shape and magnitude was demonstrated. The method can be implemented fairly easily in most modern computing languages and environments.

  5. Social economical and psychological considerations in conveying potential radiation risks from high level natural background radiation to the residents of Ramsar, Iran

    International Nuclear Information System (INIS)

    X-rays and radioactivity were discovered more than 100 years ago but the need for protection against very low doses of ionizing radiation and especially different levels of natural radiation is still among the most controversial matters in radiobiology and radiation protection. According to formal reports, some areas in Ramsar, a city in northern Iran, are the inhabited areas with the highest levels of natural radiation studied so far. A population of about 2000 is exposed to average annual radiation levels of 10.2 mGy y''-1 and the highest recorded external gamma dose rates are about 130 mGy y''-1. We have previously shown that in high background radiation areas (HBRAs), cultured human lymphocytes of the inhabitants whose cumulative radiation doses were as much as 170 times more than those of a control area when subjected to 1.5 Gy challenge dose,were significantly more radioresistant compared to the residents of the control area (Mortazavi et al. 2002a,b, Mortazavi and Karam 2002, Ghiassi-Najed et al. 2002). The people who live in these areas are usually unaware of the high levels of natural radiation in their environment. Studies performed on the residents of these areas have indicated that the effective dose of the inhabitants, in some cases, is much higher than the dose limits for occupational irradiation. Considering recent policies of ICRP regarding suggesting dose limits for exposure to natural sources of ionizing including radon, it seems that the inhabitants should become familiar with the possible risks of the exposure to high levels of ionizing radiation. They should also realize that studies performed over the past years have indicated no detrimental effect. On the other hand, according to ICRP suggestions and considering the experiences in other countries, especially evacuation of the residents of contaminated areas after Chernobyl accident, setting any radiation protection regulation for the inhabitants without considering social, economic and

  6. The cosmic background radiation circa {nu}2K

    Energy Technology Data Exchange (ETDEWEB)

    Bond, J. Richard; Pogosyan, Dmitry; Prunet, Simon

    2000-01-01

    We describe the implications of cosmic microwave background (CMB) observations and galaxy and cluster surveys of large scale structure (LSS) for theories of cosmic structure formation, especially emphasizing the recent Boomerang and Maxima CMB balloon experiments. The inflation-based cosmic structure formation paradigm we have been operating with for two decades has never been in better shape. Here we primarily focus on a simplified inflation parameter set, {l_brace}{omega}{sub b}, {omega}{sub cdm}, {omega}{sub tot}, {omega}{sub {lambda}}, n{sub s}, {tau}{sub C}, {sigma}{sub 8}{r_brace}. Combining all of the current CMB+LSS data points to the remarkable conclusion that the local Hubble patch we can access has little mean curvature ({omega}{sub tot} = 1.08 {+-} 0.06) and the initial fluctuations were nearly scale invariant (n{sub s} 1.03 {+-} 0.08), both predictions of (non-baroque) inflation theory. The baryon density is found to be slightly larger than that preferred by independent Big Bang Nucleosynthesis estimates ({omega}{sub b}-{omega}{sub b}h{sup 2} 0.030 {+-} 0.005 cf. 0.019 {+-} 0.002). The CDM density is in the expected range ({omega}{sub cdm} 0.17{+-}0.02). Even stranger is the CMB+LSS evidence that the density of the universe is dominated by unclustered energy akin to the cosmological constant ({omega}{sub {lambda}} = 0.66 {+-} 0.06), at the same level as that inferred from high redshift supernova observations. We also sketch the CMB+LSS implications for massive neutrinos.

  7. Distribution of background radiation and radioactive materials in Aomori Prefecture

    International Nuclear Information System (INIS)

    The first commercial nuclear fuel reprocessing plant in Japan is now being constructed in Rokkasho Village, Aomori Prefecture and large amounts of Pu and U will be treated in the plant. Therefore, we made a plan for getting background levels of Pu, U and other related radionuclides in soil samples around the plant beginning with plowed fields, then rice fields, orchards, forests and un-cultivated fields, ie a different field type, year by year. This is the first report of results for plowed fields. The soil samples were collected at 13 plowed fields in Rokkasho and three control sites in Tohoku Town, Hachinohe City and Hirosaki City. Five core samples of 75 mmφ, down to approximately 1 m deep, were taken in each field in 2001. Three to five layers were distinguished by a visual inspection, and the same layers from each of the five cores were combined. When depth profiles of layers for some cores were different from those of others, those cores were separately treated. Concentrations of 137Cs and 210Pb in the sample were measured with γ-ray spectrometers using Ge detectors. Pu, U and Th in the soil samples were analyzed with a ICP-MS. Since fields under yam (Dioscorea babatus) cultivation are dug up to approximately 1 m deep at harvesting, depth profiles of fallout radionuclides were heavily disturbed for most fields in Rokkasho. The mean and standard deviation of inventory of Pu (239+240Pu) in three fields where have not cultivated yam in Rokkasho was 120 ± 50 Bq m-2. The mean inventory was similar to that in Hachinohe City. However, the inventory was approximately a half of that in Hirosaki City. The Pu concentrations very well correlated with 137Cs (r=0.97), and the ratio of Pu/137Cs was 0.037 ± 0.007, which is a typical value for global fallout. This showed that the movements of Pu and 137Cs in soil were similar in spite of heavy soil disturbance, and the ratio could be used for distinguishing the plant Pu from global fallout. Since the concentrations of

  8. Telomere Length in Human Adults and High Level Natural Background Radiation

    OpenAIRE

    Birajalaxmi Das; Divyalakshmi Saini; Seshadri, M

    2009-01-01

    BACKGROUND: Telomere length is considered as a biomarker of aging, stress, cancer. It has been associated with many chronic diseases such as hypertension and diabetes. Although, telomere shortening due to ionizing radiation has been reported in vitro, no in vivo data is available on natural background radiation and its effect on telomere length. METHODOLOGY/PRINCIPAL FINDINGS: The present investigation is an attempt to determine the telomere length among human adults residing in high level na...

  9. Dipole analysis on EGRET data of extragalactic gamma ray background radiation

    Science.gov (United States)

    Lin, Ying-Chi

    1990-01-01

    A dipole analysis on the EGRET (Energetic Gamma-Ray Experimental Telescope) data seems to be one of the numerous subjects that can be investigated for the extragalactic gamma ray background radiation. By the end of the first one and half years after launch, the all-sky survey program of GRO (Gamma Ray Observatory) will be completed. The EGRET detector will cover the full sky area fairly well by that time. A set of gamma ray data suitable for dipole moment calculations will be available. Furthermore, there now exist in the literature several dipole anisotropy results calculated for optical and infrared observations on the distribution of galaxies in the full sky. The results of dipole moment analysis from gamma ray observation can be compared with those at other wavebands, and hopefully some deeper understanding can be gained on the large scale structure of the Universe.

  10. Spectrum of the cosmic background radiation: early and recent measurements from the White Mountain Research Station

    International Nuclear Information System (INIS)

    The White Mountain Research Station has provided a support facility at a high, dry, radio-quiet site for measurements that have established the blackbody character of the cosmic microwave background radiation. This finding has confirmed the interpretation of the radiation as a relic of the primeval fireball and helped to establish the hot Big Bang theory as the standard cosmological model

  11. Background radiation and childhood leukemia: A nationwide register-based case-control study.

    Science.gov (United States)

    Nikkilä, Atte; Erme, Sini; Arvela, Hannu; Holmgren, Olli; Raitanen, Jani; Lohi, Olli; Auvinen, Anssi

    2016-11-01

    High doses of ionizing radiation are an established cause of childhood leukemia. However, substantial uncertainty remains about the effect of low doses of radiation, including background radiation and potential differences between genetic subgroups of leukemia have rarely been explored. We investigated the effect of the background gamma radiation on childhood leukemia using a nationwide register-based case-control study. For each of the 1,093 cases, three age- and gender matched controls were selected (N = 3,279). Conditional logistic regression analyses were adjusted for confounding by Down syndrome, birth weight (large for gestational age), and maternal smoking. Complete residential histories and previously collected survey data of the background gamma radiation in Finland were used to assess the exposure of the study subjects to indoor and outdoor gamma radiation. Overall, background gamma radiation showed a non-significant association with the OR of childhood leukemia (OR 1.01, 95% CI 0.97, 1.05 for 10 nSv/h increase in average equivalent dose rate to red bone marrow). In subgroup analyses, age group 2-childhood leukemia, particularly at age 2-<7 years. Our findings suggest a larger effect of radiation on leukemia with high hyperpdiploidy than other subgroups, but this result requires further confirmation. PMID:27405274

  12. Cosmic background radiation anisotropy in an open inflation, cold dark matter cosmogony

    Science.gov (United States)

    Kamionkowski, Marc; Ratra, Bharat; Spergel, David N.; Sugiyama, Naoshi

    1994-01-01

    We compute the cosmic background radiation anisotropy, produced by energy-density fluctuations generated during an early epoch of inflation, in an open cosmological model based on the cold dark matter scenario. At Omega(sub 0) is approximately 0.3-0.4, the Cosmic Background Explorer (COBE) normalized open model appears to be consistent with most observations.

  13. Radiobiological analysis of region with higher radiation background. The effect of the background on the isomorphism of some enzymes

    International Nuclear Information System (INIS)

    An attempt is made to establish the the time when the prolong impact of slightly increased radiation background get over the compensator mechanisms of living systems. The object of investigation was the ecosystem of the Bay of Wromos (Black Sea, BG) and its surroundings where the flotation slack from an uranium mine was disposed. radioactivity. The following radiobiological picture of the site is obtained according to measurements performed: the alpha-activity of the beach sands is higher than one of the slack and is different in plants; the beta-activity is higher compared to controls in all samples investigated; the gamma spectra show high concentration of the members of U-238 and Th-232 series. The biological effect provoked by this heightened radiation background is studied by means of the isoenzymes as indicators of changes on molecular level. The isoenzyme spectra of lactate dehydrogenase and butyrol dehydrogenase is studied by vertical electrophoresis. The following species are tested: Tettigonia candata charp, Galliptumus italicus, Grillus campestris and Lumbicus terrestrial. An increase in activity and quantity of enzymes as well as changes of their isoenzyme spectra is observed. Calliptumus italicus could be used as a bio indicator of contamination, as it show better separation of the LDH and BDH-isoforms of LDH and BDH, and is more wide-spread. The increase in activity and quantity of some isoenzyme fractions in the conditions of this experiment is one of the possible mechanisms for increase in radioresistance of the living systems. 3 tabs., 2 figs., 8 refs

  14. DNDO Report: Predicting Solar Modulation Potentials for Modeling Cosmic Background Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Behne, Patrick Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-08

    The modeling of the detectability of special nuclear material (SNM) at ports and border crossings requires accurate knowledge of the background radiation at those locations. Background radiation originates from two main sources, cosmic and terrestrial. Cosmic background is produced by high-energy galactic cosmic rays (GCR) entering the atmosphere inducing a cascade of particles that eventually impact the earth’s surface. The solar modulation potential represents one of the primary inputs to modeling cosmic background radiation. Usosokin et al. formally define solar modulation potential as “the mean energy loss [per unit charge] of a cosmic ray particle inside the heliosphere…” Modulation potential, a function of elevation, location, and time, shares an inverse relationship with cosmic background radiation. As a result, radiation detector thresholds require adjustment to account for differing background levels, caused partly by differing solar modulations. Failure to do so can result in higher rates of false positives and failed detection of SNM for low and high levels of solar modulation potential, respectively. This study focuses on solar modulation’s time dependence and seeks the best method to predict modulation for future dates using Python. To address the task of predicting future solar modulation, we utilize both non-linear least squares sinusoidal curve fitting and cubic spline interpolation. This material will be published in transactions of the ANS winter meeting of November, 2016.

  15. Experimental study of variations in background radiation and the effect on Nuclear Car Wash sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Church, J; Slaughter, D; Norman, E; Asztalos, S; Biltoft, P

    2007-02-07

    Error rates in a cargo screening system such as the Nuclear Car Wash [1-7] depend on the standard deviation of the background radiation count rate. Because the Nuclear Car Wash is an active interrogation technique, the radiation signal for fissile material must be detected above a background count rate consisting of cosmic, ambient, and neutron-activated radiations. It was suggested previously [1,6] that the Corresponding negative repercussions for the sensitivity of the system were shown. Therefore, to assure the most accurate estimation of the variation, experiments have been performed to quantify components of the actual variance in the background count rate, including variations in generator power, irradiation time, and container contents. The background variance is determined by these experiments to be a factor of 2 smaller than values assumed in previous analyses, resulting in substantially improved projections of system performance for the Nuclear Car Wash.

  16. Real Time Wide Area Radiation Surveillance System

    Science.gov (United States)

    Biafore, M.

    2012-04-01

    We present the REWARD project, financed within the FP7 programme, theme SEC-2011.1.5-1 (Development of detection capabilities of difficult to detect radioactive sources and nuclear materials - Capability Project). Within this project, we propose a novel mobile system for real time, wide area radiation surveillance. The system is based on the integration of new miniaturized solid-state radiation sensors: a CdZnTe detector for gamma radiation and a high efficiency neutron detector based on novel silicon technologies. The sensing unit will include a wireless communication interface to send the data remotely to a monitoring base station which also uses a GPS system to calculate the position of the tag. The system will also incorporate middleware and high level software to provide web-service interfaces for the exchange of information, and that will offer top level functionalities as management of users, mobile tags and environment data and alarms, database storage and management and a web-based graphical user interface. Effort will be spent to ensure that the software is modular and re-usable across as many architectural levels as possible. Finally, an expert system will continuously analyze the information from the radiation sensor and correlate it with historical data from the tag location in order to generate an alarm when an abnormal situation is detected. The system will be useful for many different scenarios, including such lost radioactive sources and radioactive contamination. It will be possible to deploy in emergency units and in general in any type of mobile or static equipment. The sensing units will be highly portable thanks to their low size and low energy consumption. The complete system will be scalable in terms of complexity and cost and will offer very high precision on both the measurement and the location of the radiation. The modularity and flexibility of the system will allow for a realistic introduction to the market. Authorities may start with a

  17. State background-radiation levels: results of measurements taken during 1975-1979

    Energy Technology Data Exchange (ETDEWEB)

    Myrick, T.E.; Berven, B.A.; Haywood, F.F.

    1981-11-01

    Background radiation levels across the United States have been measured by the Off-Site Pollutant Measurements Group of the Health and Safety Research Division at Oak Ridge National Laboratory (ORNL). These measurements have been conducted as part of the ORNL program of radiological surveillance at inactive uranium mills and sites formerly utilized during Manhattan Engineer District and early Atomic Energy Commission projects. The measurements included determination of /sup 226/Ra, /sup 232/Th, and /sup 238/U concentrations in surface soil samples and measurement of external gamma-ray exposure rates at 1 m above the ground surface at the location of soil sampling. This information is being utilized for comparative purposes to determine the extent of contamination present at the survey sites and surrounding off-site areas. The sampling program to date has provided background information at 356 locations in 33 states. External gamma-ray exposure rates were found to range from less than 1 to 34 ..mu..R/h, with an US average of 8.5 ..mu..R/h. The nationwide average concentrations of /sup 226/Ra, /sup 232/Th, and /sup 238/U in surface soil were determined to be 1.1, 0.98, and 1.0 pCi/g, respectively.

  18. State background-radiation levels: results of measurements taken during 1975-1979

    International Nuclear Information System (INIS)

    Background radiation levels across the United States have been measured by the Off-Site Pollutant Measurements Group of the Health and Safety Research Division at Oak Ridge National Laboratory (ORNL). These measurements have been conducted as part of the ORNL program of radiological surveillance at inactive uranium mills and sites formerly utilized during Manhattan Engineer District and early Atomic Energy Commission projects. The measurements included determination of 226Ra, 232Th, and 238U concentrations in surface soil samples and measurement of external gamma-ray exposure rates at 1 m above the ground surface at the location of soil sampling. This information is being utilized for comparative purposes to determine the extent of contamination present at the survey sites and surrounding off-site areas. The sampling program to date has provided background information at 356 locations in 33 states. External gamma-ray exposure rates were found to range from less than 1 to 34 μR/h, with an US average of 8.5 μR/h. The nationwide average concentrations of 226Ra, 232Th, and 238U in surface soil were determined to be 1.1, 0.98, and 1.0 pCi/g, respectively

  19. Aerosol optical, microphysical and radiative properties at regional background insular sites in the western Mediterranean

    Science.gov (United States)

    Sicard, Michaël; Barragan, Rubén; Dulac, François; Alados-Arboledas, Lucas; Mallet, Marc

    2016-09-01

    In the framework of the ChArMEx (the Chemistry-Aerosol Mediterranean Experiment; http://charmex.lsce.ipsl.fr/) program, the seasonal variability of the aerosol optical, microphysical and radiative properties derived from AERONET (Aerosol Robotic Network; http://aeronet.gsfc.nasa.gov/) is examined in two regional background insular sites in the western Mediterranean Basin: Ersa (Corsica Island, France) and Palma de Mallorca (Mallorca Island, Spain). A third site, Alborán (Alborán Island, Spain), with only a few months of data is considered for examining possible northeast-southwest (NE-SW) gradients of the aforementioned aerosol properties. The AERONET dataset is exclusively composed of level 2.0 inversion products available during the 5-year period 2011-2015. AERONET solar radiative fluxes are compared with ground- and satellite-based flux measurements. To the best of our knowledge this is the first time that AERONET fluxes are compared with measurements at the top of the atmosphere. Strong events (with an aerosol optical depth at 440 nm greater than 0.4) of long-range transport aerosols, one of the main drivers of the observed annual cycles and NE-SW gradients, are (1) mineral dust outbreaks predominant in spring and summer in the north and in summer in the south and (2) European pollution episodes predominant in autumn. A NE-SW gradient exists in the western Mediterranean Basin for the aerosol optical depth and especially its coarse-mode fraction, which all together produces a similar gradient for the aerosol direct radiative forcing. The aerosol fine mode is rather homogeneously distributed. Absorption properties are quite variable because of the many and different sources of anthropogenic particles in and around the western Mediterranean Basin: North African and European urban areas, the Iberian and Italian peninsulas, most forest fires and ship emissions. As a result, the aerosol direct forcing efficiency, more dependent to absorption than the absolute

  20. THE BACKGROUND RADIATION AND EXPOSURE LEVELS AT VARIOUS SOUTH AFRICAN WEST COAST MILITARY UNITS

    Directory of Open Access Journals (Sweden)

    Jacques Bezuidenhout

    2014-11-01

    Full Text Available The West Coast of South Africa between St Helena Bay to the north and Langebaan Lagoon to the south is characterised by numerous granite protrusions. These outcrops are elements of the underlying Cape Granite Suite, which forms the bedrock of a large part of the Western Cape. Granite contains high levels of natural radionuclides, which results in high levels of natural background radiation in the surrounding area. The impacts of these high levels of radiation exposure on military personal are of concern. There are four military units located in this part of the West Coast, namely SAS Saldanha, 4 Special Forces Regiment, Langebaan Road Air Force Base and the Military Academy. Different sites in and around these military units were selected and soil samples were taken. Laboratory gamma ray measurements were done to determine the levels of natural radioactive nuclides in the soil samples. The radioactive nuclide concentrations were interpolated and then mapped with the help of geographic information systems (also known as geospatial information systems or GIS software. An evaluation of the annual dose rate of military personnel at the units on the West Coast was made and found to range between 0,017 mSv/y and 0,163 mSv/y. These values were mapped and compared to the average global annual dose rate of 0,070 mSv/y. This article reports on an investigation of these results and the overall exposure levels of personnel from the various military units on the West Coast of South Africa.

  1. Radial HI Profiles at the Periphery of Galactic Disks: The Role of Ionizing Background Radiation

    CERN Document Server

    Abramova, O V

    2012-01-01

    Observations of neutral hydrogen in spiral galaxies reveal a sharp cutoff in the radial density profile at some distance from the center. Using 22 galaxies with known HI distributions as an example, we discuss the question of whether this effect can be associated exclusively with external ionizing radiation, as is commonly assumed. We show that before the surface density reaches $\\sigma_{\\textrm{HI}}\\le 0.5 {\\cal M}_\\odot/{\\textrm {pc}}^2$(the same for galaxies of different types), it is hard to expect the gas to be fully ionized by background radiation. For two of 13 galaxies with a sharp drop in the HI profile, the "steepening" can actually be caused by ionization. At the same time, for the remaining galaxies, the observed cutoff in the radial HI profile is closer to the center than if it was a consequence of ionization by background radiation and, therefore, it should be caused by other factors.

  2. Radiation Target Area Sample Environmental Chamber (RTASEC) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Payload Systems Inc. proposes the Radiation Target Area Sample Environmental Chamber (RTASEC) as an innovative approach enabling radiobiologists to investigate the...

  3. Excess relative risk of solid cancer mortality after prolonged exposure to naturally occurring high background radiation in Yangjiang, China

    Energy Technology Data Exchange (ETDEWEB)

    Sun Quanfu; Tao Zufan [Ministry of Health, Beijing (China). Lab. of Industrial Hygiene; Akiba, Suminori (and others)

    2000-10-01

    A study was made on cancer mortality in the high-background radiation areas of Yangjiang, China. Based on hamlet-specific environmental doses and sex- and age-specific occupancy factors, cumulative doses were calculated for each subject. In this article, we describe how the indirect estimation was made on individual dose and the methodology used to estimate radiation risk. Then, assuming a linear dose response relationship and using cancer mortality data for the period 1979-1995, we estimate the excess relative risk per Sievert for solid cancer to be -0.11 (95% CI, -0.67, 0.69). Also, we estimate the excess relative risks of four leading cancers in the study areas, i.e., cancers of the liver, nasopharynx, lung and stomach. In addition, we evaluate the effects of possible bias on our risk estimation. (author)

  4. The 1999 Lauriston S. Taylor lecture--back to background: natural radiation and radioactivity exposed.

    Science.gov (United States)

    Harley, N H

    2000-08-01

    I am profoundly grateful for being chosen as the twenty-third presenter of the Lauriston S. Taylor Lecture, and I share this honor with a list of distinguished scientists, including my husband, who pay tribute to the premier leader in radiation protection. In 1938, Laurie was working for the National Bureau of Standards and chaired the Advisory Committee on X-ray and Radium Protection, a group of 8 persons, who set the pace for all forthcoming radiation standards. NBS had, since 1913, been standardizing essentially all of the radium offered for sale in the U.S., and the problem arose to revise the handbook on proper conditions for handling radium based on the then current knowledge. This resulted in Handbook 23 (1938) superseding the 1934 work. At the time Laurie was a scientist working in the measurements side of radiation and though he contributed much to that field, his name is inseparably linked with guidance in radiation protection. Today we pay tribute for his leadership that he carried out with intelligence, grace, and personal warmth. My talk today deals mostly with measured data for naturally occurring internal radiation emitters and how these data can be used for predictive purposes in estimating the dose and risk from internal body contamination. This stresses the "and Measurements" part of the Council's title. The topic of this year's NCRP Annual Meeting is "Radiation Protection in Medicine: Contemporary Issues." I believe that physicians and State and Federal agencies will have to cope with complaints following various exposure situations resulting from the cleanup of background radionuclides during closure at nuclear facilities, military use of radioactivity, and occurrences of high natural background in some locations. They will find comfort in the knowledge that existing background radiation data can be the basis for predictions of realistic dose and risk in most situations. PMID:10910381

  5. Real-Time Airborne Gamma-Ray Background Estimation Using NASVD with MLE and Radiation Transport for Calibration

    Energy Technology Data Exchange (ETDEWEB)

    Kulisek, Jonathan A.; Schweppe, John E.; Stave, Sean C.; Bernacki, Bruce E.; Jordan, David V.; Stewart, Trevor N.; Seifert, Carolyn E.; Kernan, Warnick J.

    2015-06-01

    Helicopter-mounted gamma-ray detectors can provide law enforcement officials the means to quickly and accurately detect, identify, and locate radiological threats over a wide geographical area. The ability to accurately distinguish radiological threat-generated gamma-ray signatures from background gamma radiation in real time is essential in order to realize this potential. This problem is non-trivial, especially in urban environments for which the background may change very rapidly during flight. This exacerbates the challenge of estimating background due to the poor counting statistics inherent in real-time airborne gamma-ray spectroscopy measurements. To address this, we have developed a new technique for real-time estimation of background gamma radiation from aerial measurements. This method is built upon on the noise-adjusted singular value decomposition (NASVD) technique that was previously developed for estimating the potassium (K), uranium (U), and thorium (T) concentrations in soil post-flight. The method can be calibrated using K, U, and T spectra determined from radiation transport simulations along with basis functions, which may be determined empirically by applying maximum likelihood estimation (MLE) to previously measured airborne gamma-ray spectra. The method was applied to both measured and simulated airborne gamma-ray spectra, with and without man-made radiological source injections. Compared to schemes based on simple averaging, this technique was less sensitive to background contamination from the injected man-made sources and may be particularly useful when the gamma-ray background frequently changes during the course of the flight.

  6. Radiation-Hydrodynamical Collapse of Pregalactic Clouds in the Ultraviolet Background

    CERN Document Server

    Kitayama, T; Umemura, M; Susa, H; Ikeuchi, S

    2000-01-01

    To elucidate the effects of the UV background radiation on the collapse of pregalactic clouds, we implement a radiation-hydrodynamical calculation, combining one-dimensional spherical hydrodynamics with an accurate treatment of the radiative transfer of ionizing photons. Both absorption and scattering of UV photons are explicitly taken into account. It turns out that a gas cloud contracting within the dark matter potential does not settle into hydrostatic equilibrium, but undergoes run-away collapse even under the presence of the external UV field. The cloud center is shown to become self-shielded against ionizing photons by radiative transfer effects before shrinking to the rotation barrier. Based on our simulation results, we further discuss the possibility of H2 cooling and subsequent star formation in a run-away collapsing core. The present results are closely relevant to the survival of subgalactic Population III objects as well as to metal injection into intergalactic space.

  7. Qualitative values of radioactivity, area and volumetric: Application on phantoms (target and background)

    International Nuclear Information System (INIS)

    The visualization of a lesion depends on the contrast between the lesion and surrounding background (T/B; (target/background) ratio). For imaging in vivo not only is the radioactivity in the target organ important, but so too is the ratio of radioactivity in the target versus that in the background. Nearly all studies reported in the literature have dealt with the surface index, as a standard factor to study the relationship between the target (tissue or organ) and the background. It is necessary to know the ratio between the volumetric activity of lesions (targets) and normal tissues (background) instead of knowing the ratio between the area activity, the volume index being a more realistic factor than the area index as the targets (tissues or organs) are real volumes that have surfaces. The intention is that this work should aid in approaching a quantitative relationship and differentiation between different tissues (target/background or abnormal/normal tissues). For the background, square regions of interest (Rios) (11x11 pixels in size) were manually drawn by the observer at locations far from the border of the plastic cylinder (simulated organ), while an isocontour region with 50% threshold was drawn automatically over the cylinder. The total number of counts and pixels in each of these regions was calculated. The relationship between different phantom parameters, cylinder (target) depth, area activity ratio (background/target, A(B/T)) and real volumetric activity ratio (background/target, V(B/T)), was demonstrated. Variations in the area and volumetric activity ratio values with respect to the depth were deduced. To find a realistic value of the ratio, calibration charts have been constructed that relate the area and real volumetric ratios as a function of depth of the tissues and organs. Our experiments show that the cross-sectional area of the cylinder (applying a threshold 50% isocontour) has a weak dependence on the activity concentrations of the

  8. On the population of primordial star clusters in the presence of UV background radiation

    CERN Document Server

    MacIntyre, M A; Thomas, P A; Intyre, Michael A. Mac; Santoro, Fernando; Thomas, Peter A.

    2006-01-01

    We use the algorithm of Cole et al. (2000) to generate merger trees for the first star clusters in a Lambda CDM cosmology under an isotropic UV background radiation field, parametrized by J_21. We have investigated the problem in two ways: a global radiation background and local radiative feedback surrounding the first star clusters. Cooling in the first halos at high redshift is dominated by molecular hydrogen, H_2 - we call these Generation 1 objects. At lower redshift and higher virial temperature, T_vir > 10^4K, electron cooling dominates - we call these generation 2. Radiation fields act to photo-dissociate H_2, but also generate free electrons that can help to catalyse its production. At modest radiation levels, J_{21}/(1+z)^3 ~ 10^{-12}-10^{-7}, the nett effect is to enhance the formation of Generation 1 star-clusters. At higher fluxes the heating from photo-ionisation dominates and halts their production. With a realistic build-up of flux over time, the period of enhanced H_2 cooling is so fleeting as...

  9. Probing the Light Speed Anisotropy with respect to the Cosmic Microwave Background Radiation Dipole

    CERN Document Server

    Gurzadyan, V G; Kashin, A L; Margarian, A T; Bartalini, O; Bellini, V; Castoldi, M; D'Angelo, A; Didelez, J P; Salvo, R D; Fantini, A; Gervino, G; Ghio, F; Girolami, B; Giusa, A; Hourany, E; Knyazyan, S; Kuznetsov, V E; Lapik, A; Levi-Sandri, P; Llères, A; Mehrabyan, S S; Moricciani, D; Nedorezov, V; Perrin, C; Rebreyend, D; Russo, G; Rudnev, N; Schärf, C; Sperduto, M L; Sutera, M C; Turinge, A

    2005-01-01

    We have studied the angular fluctuations in the speed of light with respect to the apex of the dipole of Cosmic Microwave Background (CMB) radiation using the experimental data obtained with GRAAL facility, located at the European Synchrotron Radiation Facility (ESRF) in Grenoble. The measurements were based on the stability of the Compton edge of laser photons scattered on the 6 GeV monochromatic electron beam. The results enable to obtain a conservative constraint on the anisotropy in the light speed variations \\Delta c(\\theta)/c < 3 10^{-12}, i.e. with higher precision than from previous experiments.

  10. Rydberg atom detection of the temporal coherence of cosmic microwave background radiation

    CERN Document Server

    Tscherbul, Timur V

    2013-01-01

    Rydberg atoms immersed in cold blackbody radiation are shown to display long-lived quantum coherence effects on timescales of tens of picoseconds. By solving non-Markovian equations of motion with no free parameters we obtain the time evolution of the density matrix, and demonstrate that the blackbody-induced temporal coherences manifest as quantum beats in time-resolved fluorescence intensities of the Rydberg atoms. A measurable fluorescence signal can be obtained with a cold trapped ensemble of 1e8 Rydberg atoms subject to 2.7 K cosmic microwave background radiation (CMB), allowing for novel insights into previously unexamined quantum coherence properties of CMB.

  11. Background ozone in the southern Europe and Mediterranean area: Influence of the transport processes

    International Nuclear Information System (INIS)

    The troposphere is subject to continuous inputs, production and removal processes of ozone and its precursors from natural processes and human activities acting together within a very complex system. In order to assess the behaviour of background ozone in the Mediterranean area, a description of trends, seasonal and diurnal behaviours of free tropospheric ozone is provided. In the Mediterranean area and southern Europe the background tropospheric ozone concentration appears significantly affected by three main air mass transport processes: (i) transport of polluted air masses on regional and long-range scales, (ii) downward transport of stratospheric air masses, and (iii) transport of mineral dust from the Sahara desert. In this review of the literature of the last two decades, we present an overview of these phenomena, mainly monitored at high baseline mountain stations representative of background atmospheric conditions. - How background ozone is influenced by vertical and horizontal transport processes in the southern Europe and the Mediterranean area.

  12. Probing reionization with the cross power spectrum of 21 cm and near-infrared radiation backgrounds

    CERN Document Server

    Mao, Xiao-Chun

    2014-01-01

    The cross-correlation between the 21 cm emission from the high-redshift intergalactic medium and the near-infrared (NIR) background light from the high-redshift galaxies promises to be a powerful probe of cosmic reionization. In this paper, we investigate the cross power spectrum during the epoch of reionization. We employ an improved halo approach to derive the distribution of the density field and consider two stellar populations in the star formation model: metal-free stars and metal-poor stars. The reionization history is further generated to be consistent with the electron-scattering optical depth from cosmic microwave background measurements. Then the intensity of NIR background is estimated by collecting emission from stars in the first-light galaxies. On large scales, we find the 21 cm and NIR radiation backgrounds are positively correlated during the very early stages of reionization. However, these two radiation backgrounds quickly become anti-correlated as reionization proceeds. The maximum absolut...

  13. On the Light Speed Anisotropy vs Cosmic Microwave Background Dipole: European Synchrotron Radiation Facility Measurements

    CERN Document Server

    Gurzadyan, V G; Kashin, A; Margarian, A T; Bartalini, O; Bellini, V; Castoldi, M; D'Angelo, A; Didelez, J P; Salvo, R D; Fantini, A; Gervino, G; Ghio, F; Girolami, B; Giusa, A; Guidal, M; Hourany, E; Knyazyan, S; Kouznetsov, V; Kunne, Ronald Alexander; Lapik, A; Levi-Sandri, P; Llères, A; Mehrabyan, S S; Moricciani, D; Nedorezov, V; Perrin, C; Rebreyend, D; Russo, G; Rudnev, N; Schärf, C; Sperduto, M L; Sutera, M C; Turinge, A

    2007-01-01

    The measurement of the Compton edge of the scattered electrons in GRAAL facility in European Synchrotron Radiation Facility (ESRF) in Grenoble with respect to the Cosmic Microwave Background dipole reveals up to 10 sigma variations larger than the statistical errors. We now show that the variations are not due to the frequency variations of the accelerator. The nature of Compton edge variations remains unclear, thus outlining the imperative of dedicated studies of light speed anisotropy.

  14. Primordial Gravitational Waves and Rescattered Electromagnetic Radiation in the Cosmic Microwave Background

    CERN Document Server

    Kim, Dong-Hoon

    2016-01-01

    Understanding the interaction of primordial gravitational waves (GWs) with the Cosmic Microwave Background (CMB) plasma is important for observational cosmology. In this article, we provide an analysis of an effect apparently overlooked as yet. We consider a single free electric charge and suppose that it can be agitated by primordial GWs propagating through the CMB plasma, resulting in periodic, regular motion along particular directions. Light reflected by the charge will be partially polarized, and this will imprint a characteristic pattern on the CMB. We study this effect by considering a simple model in which anisotropic incident electromagnetic (EM) radiation is rescattered by a charge sitting in spacetime perturbed by GWs and becomes polarized. As the charge is driven to move along particular directions, we calculate its dipole moment to determine the leading-order rescattered EM radiation. The Stokes parameters of the rescattered radiation exhibit a net linear polarization. We investigate how this pol...

  15. Growth retardation of paramecium and mouse cells by shielding them from background radiation

    International Nuclear Information System (INIS)

    In the 1970s and 1980s, Planel et al. reported that the growth of paramecia was decreased by shielding them from background radiation. In the 1990s, Takizawa et al. found that mouse cells displayed a decreased growth rate under shielded conditions. The purpose of the present study was to confirm that growth is impaired in organisms that have been shielded from background radiation. Radioprotection was produced with a shielding chamber surrounded by a 15 cm thick iron wall and a 10 cm thick paraffin wall that reduced the γ ray and neutron levels in the chamber to 2% and 25% of the background levels, respectively. Although the growth of Paramecium tetraurelia was not impaired by short-term radioprotection (around 10 days), which disagreed with the findings of Planel et al., decreased growth was observed after long-term (40-50 days) radiation shielding. When mouse lymphoma L5178Y cells were incubated inside or outside of the shielding chamber for 7 days, the number of cells present on the 6th and 7th days under the shielding conditions was significantly lower than that present under the non-shielding conditions. These inhibitory effects on cell growth were abrogated by the addition of a 137Cs γ-ray source disk to the chamber. Furthermore, no growth retardation was observed in XRCC4-deficient mouse M10 cells, which display impaired DNA double strand break repair. (author)

  16. Radiation Backgrounds at Cosmic Dawn: X-Rays from Compact Binaries

    CERN Document Server

    Madau, Piero

    2016-01-01

    We compute the expected X-ray diffuse background and radiative feedback on the intergalactic medium (IGM) from X-ray binaries prior and during the epoch of reionization. The cosmic evolution of compact binaries is followed using a population synthesis technique that treats separately neutron stars and black hole binaries in different spectral states and is calibrated to reproduce the observed X-ray properties of galaxies at z6. Radiative transfer effects modulate the background spectrum, which shows a characteristic peak between 1 and 2 keV. While the filtering of X-ray radiation through the IGM slightly increases the mean excess energy per photoionization, it also weakens the radiation intensity below 1 keV, lowering the mean photoionization and heating rates. Numerical integration of the rate and energy equations shows that the contribution of X-ray binaries to the ionization of the bulk IGM is negligible, with the electron fraction never exceeding 1%. Direct HeI photoionizations are the main source of IGM ...

  17. Background X-ray Radiation Fields Produced by Young Embedded Star Clusters

    CERN Document Server

    Adams, Fred; Holden, Lisa

    2012-01-01

    Most star formation in our galaxy occurs within embedded clusters, and these background environments can affect the star and planet formation processes occurring within them. In turn, young stellar members can shape the background environment and thereby provide a feedback mechanism. This work explores one aspect of stellar feedback by quantifying the background X-ray radiation fields produced by young stellar objects. Specifically, the distributions of X-ray luminosities and X-ray fluxes produced by cluster environments are constructed as a function of cluster membership size $N$. Composite flux distributions, for given distributions of cluster sizes $N$, are also constructed. The resulting distributions are wide and the X-ray radiation fields are moderately intense, with the expected flux levels exceeding the cosmic and galactic X-ray backgrounds by factors of $\\sim10-1000$ (for energies 0.2 -- 15 keV). For circumstellar disks that are geometrically thin and optically thick, the X-ray flux from the backgrou...

  18. Fast washout of thallium-201 from area of myocardial infarction: possible artifact of background subtraction

    Energy Technology Data Exchange (ETDEWEB)

    Brown, K.A.; Benoit, L.; Clements, J.P.; Wackers, F.J.

    1987-06-01

    A recent report described a pattern of reverse redistribution on poststreptokinase /sup 201/Tl studies which was believed to be due to rapid washout of /sup 201/Tl from the infarct area related to reperfusion of the infarct vessel. We have also observed the phenomenon of rapid washout of /sup 201/Tl from the area of infarction in the absence of thrombolytic therapy. This study was undertaken to test the hypothesis that rapid washout of /sup 201/Tl from an area of infarction is an artifact of background subtraction usually employed in analysis of washout. A total of 61 patients with previous myocardial infarction who underwent cardiac catheterization and exercise /sup 201/Tl imaging were examined. Thallium-201 images were analyzed using a validated quantitative method employing interpolative background correction. Abnormally increased /sup 201/Tl washout was noted in 11 infarct segments in 10 (18%) patients. Infarct segments with rapid washout had significantly less initial uptake, and more severe associated wall motion abnormalities than infarct segments with normal washout. When quantitative analysis was repeated without background subtraction, no segments with rapid washout were observed. A phantom model was constructed to further test our hypothesis. The frequency of observed rapid washout was directly related to the severity of the initial defect and was entirely dependent upon utilizing background correction during the quantitative analysis. Our study suggests that rapid washout of /sup 201/Tl in an area of previous infarction reflects an artifact of background subtraction involved with standard quantitative analysis.

  19. Research And Investigation To Establish The Database Of Environment Radiation Background For Vietnam (Phase 2009 -2011)

    International Nuclear Information System (INIS)

    Setting up data base of natural radiation background serves for planning socio-economics development in a province as well as the whole country and estimating annual effective dose of population. Beside external irradiation dose caused by the natural radioisotopes in the series 238U, 232Th and 40K in soil, population has been received internal dose caused by the above radioisotopes taken in the body from several ways. In order to complete the database of national radiation background and go to estimate annual effective radiation dose of population in the whole country, this project focus to carry out the works as following: (i) Setting up database of radiation background in the whole country: 150 soil samples that collected in the districts of 46 provinces have been analyzed. The average activity concentration of 238U, 232Th and 40K are 37.86 Bq/kg, 58.88 Bq/kg and 462.78 Bq/kg, respectively. The outdoor, indoor and total annual effective doses are calculated: 0.087±0.036 mSv; 0.488±0.202 mSv and 0.576± 0.240 mSv, respectively. (ii) Setting up database of radiation background of province Ninh Thuan and Quang Nam: The detailed database of radiation background of all villages in Ninh Thuan and Quang Nam has been established. 84 soil samples in Ninh Thuan and 311 in Quang Nam were collected for analyze. The indoor and outdoor radon concentration at sampling positions has been measured. The average activities of 238U, 232Th, 40K, and 222Rn isotopes in Ninh Thuan are reported: 33.50 Bq/kg, 55.43 Bq/kg, 701.12 Bq/kg and 12.1 Bq/m3, 9.5 Bq/m3, respectively. The outdoor, indoor and total annual effective doses in Ninh Thuan are calculated: 0.095±0.029 mSv; 0.529±0.162 mSv and 0.624± 0.382 mSv, respectively. The average activities of 238U, 232Th, 40K, and 222Rn isotopes in Quang Nam are reported: 44.47 Bq/kg, 52.68 Bq/kg, 459.33 Bq/kg, 18.0 Bq/m3. The outdoor, indoor and total annual effective doses are calculated: 0.086±0.039 mSv; 0.482±0.216 mSv and 0.568± 0

  20. The environment radiation capacities in the area of CIAE

    International Nuclear Information System (INIS)

    The authors mainly introduce the meaning of the environmental radiation capacities and the methodologies of determining them, the environmental radiation capacities of each of the environmental elements (atmosphere, surface water and groundwater) and the total environmental radiation capacities in the area of CIAE have been estimated by all-path-ways methods. This work will provide the scientific evidences to draft the long-term developing plans and to arrange the new facilities reasonably for CIAE

  1. Coherent dynamics of Rydberg atoms in cosmic-microwave-background radiation

    Science.gov (United States)

    Tscherbul, Timur V.; Brumer, Paul

    2014-01-01

    Rydberg atoms excited by cold blackbody radiation are shown to display long-lived quantum coherences on time scales of tens of picoseconds. By solving non-Markovian equations of motion with no free parameters we obtain the time evolution of the density matrix and demonstrate that the blackbody-induced temporal coherences manifest as slowly decaying (100 ps) quantum beats in time-resolved fluorescence. An analytic model shows the dependence of the coherent dynamics on the energy splitting between atomic eigenstates, transition dipole moments, and coherence time of the radiation. Experimental detection of the fluorescence signal from a trapped ensemble of 108 Rydberg atoms is discussed, but shown to be technically challenging at present, requiring cosmic-microwave-background amplification somewhat beyond current practice.

  2. A comprehensive approach to the euro-area crisis: Background calculations

    OpenAIRE

    Zsolt Darvas; Christophe Gouardo; Jean Pisani-Ferry; André Sapir

    2011-01-01

    This background paper describes in detail the assumptions and calculations behind the results presented in Zsolt Darvas, Jean Pisani-Ferry and André Sapir "A comprehensive approach to the euro-area debt crisis", Bruegel Policy Brief No 2011/02, February 2011. An assessment of the results and policy conclusions can be found in the Policy Brief.

  3. A comprehensive approach to the euro-area debt crisis: Background calculations

    OpenAIRE

    Darvas, Zsolt; Gouardo, Christophe; Pisani-Ferry, Jean; Sapir, André

    2011-01-01

    This background paper describes in detail the assumptions and calculations behind the results presented in Zsolt Darvas, Jean Pisani-Ferry and André Sapir 'A comprehensive approach to the euro-area debt crisis', Bruegel Policy Brief No 2011/02, February 2011. An assessment of the results and policy conclusions can be found in the Policy Brief.

  4. Natural background radiation and 137Cs inventories in southern Nevada. Preliminary report on fallout, December 1980

    International Nuclear Information System (INIS)

    External radiation measurements and soil sampling were performed at 28 sites in southern Nevada as part of an extensive radiological survey to determine residual levels of fission products and transuranic nuclides in Utah and Nevada as a result of nuclear weapons tests at the Nevada Test Site (NTS) during 1951 to 1958. The natural background exposure rate was found to vary by about a factor of two. The 137Cs inventories tended to be lower than expected indicating the effects of wind erosion. Cobalt-60 and 241Am were detected at several sites which were reported to be hotspots in post-shot radiological surveys

  5. Cosmic Microwave Background Radiation Constraints on a Modified Chaplygin Gas Model

    Institute of Scientific and Technical Information of China (English)

    LIU Dao-Jun; LI Xin-Zhou

    2005-01-01

    @@ A modified Chaplygin gas model of unifying dark energy and dark matter with the exotic equation of state p = Bρ- A/ρα , which can also explain the recent expansion of the universe, is investigated by means of constraining the location of the peak of the cosmic microwave background radiation spectrum. We find that the result of CMBR measurements does not exclude the nonzero value of parameter B, but allows it in the range -0.35 (<~) B (<~) 0.025.

  6. Cosmological perturbations of quantum mechanical origin and anisotropy of the microwave background radiation

    CERN Document Server

    Grishchuk, L P

    1994-01-01

    A theory of quantum-mechanical generation of cosmological perturbations is considered. The conclusion of this study is that if the large-angular-scale anisotropy in the cosmic microwave background radiation is caused by the long-wavelength cosmological perturbations of quantum mechanical origin, they are, most likely, gravitational waves, rather than density perturbations or rotational perturbations. Some disagreements with previous publications are clarified. This contribution to the Proceedings is based on Reference~[34]. NOTE: To generate an output, please extract and save the file crckapb.sty which appear at the beginning of the main file.

  7. Biaxial lidar efficiency rising based on improving of spatial selectivity and stability against background radiation

    Energy Technology Data Exchange (ETDEWEB)

    Agishev, R.R.; Bajazitov, R.A.; Galeyev, M.M. [Kazan State Technical Univ., Tatarstan (Russian Federation). Dept. of Radioelectronic and Quantum Systems

    1996-12-31

    A criterion of spatial-angular efficiency (SAE) of remote electro-optical systems for atmosphere monitoring is formulated. The dependencies of the SAE from normalized range and minimal operating range for different optical receiving schemes of ground-based biaxial lidar are analyzed. It is shown that low SAE of traditional VIS and NIR systems are a main cause of a low signal-to-background-noise ratio at the photodetector input, the considerable measurements errors. and the following low accuracy of atmospheric optical parameters reconstruction. The most effective protection against sky background radiation in such systems consists in forming an angular field according to the introduced SAE criterion. Some approaches to achieve high value of the SAE-parameter for receiving system optimization are discussed.

  8. NCRP Program Area Committee 2: Operational Radiation Safety.

    Science.gov (United States)

    Goldin, Eric M; Pryor, Kathryn H

    2016-02-01

    Program Area Committee 2 of the National Council on Radiation Protection and Measurements provides guidance for radiation safety in occupational settings in a variety of industries and activities. The Committee completed three reports in recent years covering recommendations for the development and administration of radiation safety programs for smaller educational institutions, requirements for self-assessment programs that improve radiation safety and identify and correct deficiencies, and a comprehensive process for effective investigation of radiological incidents. Ongoing work includes a report on sealed radioactive source controls and oversight of a report on radioactive nanomaterials focusing on gaps within current radiation safety programs. Future efforts may deal with operational radiation safety programs in fields such as the safe use of handheld and portable x-ray fluorescence analyzers, occupational airborne radioactive contamination, unsealed radioactive sources, or industrial accelerators.

  9. NCRP Program Area Committee 2: Operational Radiation Safety

    Energy Technology Data Exchange (ETDEWEB)

    Pryor, Kathryn H.; Goldin, Eric M.

    2016-02-29

    Program Area Committee 2 of the National Council on Radiation Protection and Measurements provides guidance for radiation safety in occupational settings in a variety of industries and activities. The committee completed three reports in recent years covering recommendations for the development and administration of radiation safety programs for smaller educational institutions, requirements for self-assessment programs that improve radiation safety and identify and correct deficiencies, and a comprehensive process for effective investigation of radiological incidents. Ongoing work includes a report on sealed radioactive source controls and oversight of a report on radioactive nanomaterials focusing on gaps within current radiation safety programs. Future efforts may deal with operational radiation safety programs in fields such as the safe use of handheld and portable X-Ray fluorescence analyzers, occupational airborne radioactive contamination, unsealed radioactive sources, or industrial accelerators.

  10. Impact of fertilizers on background radioactivity level in two newly developed desert areas

    Science.gov (United States)

    Ahmad, Fawzia

    A survey of soils and plants was carried out to determine the environmental gamma background radiation levels in two newly developed desert areas. The materials and the standards were analyzed by gamma spectroscopy; a shielded high purity germanium detector was used to measure the natural concentration of 238U, 232Th and 40K activities in the samples. The radionuclide content in some commercial fertilizers was determined. The results of the analysis of specific activities in the fertilizers under study were 1.27-950.09 Bq/kg for 238U, 0.73-162.16 Bq/kg for 232Th and 10.22-23845.24 Bq/kg for 40K. All natural soil samples showed low-activity concen-trations. The concentrations of 238U (6.13-38.84 Bq/kg) and 232Th (2.58-25.69 Bq/kg) are quite similar, whereas that of 40K (113.91-9314.11 Bq/kg) are much higher for plant samples. Some of the results obtained are larger than the permissible international radioactivity levels. It is suitable in this regard to compare the activity values of the imported fertilizers and that fabricated in Egypt. The absorbed dose rate was found to be 1.91-1027 nGy/h and the radium equivalent activity concentration was 4.02-1840.98 Bq/kg for fertilizer samples. Soil and plant sample results were 11.86-415E29 nGy/h and 24.20-750.52 Bq/kg for the absorbed dose rate and the radium equivalent activity concentration, respectively. Banana plant contains the largest values. This article presents actual data from investigations of the soil-plant transfer of the primordial radionuclides for some fruits growing on these soils. The transfer factors of 0.35-1.821 for 238U, 0.227-0.480 for 232Th and 1.95-31.85 for 40K were obtained. The increase of the transfer of 40K reflects its great uptake to the fruits. Observed soil-plant factors vary widely, mainly as a result of different soil, vegetation types and environmental conditions. Taking into account the transfer factors of 137Cs to plants, the measured activity concentrations of this isotope should not

  11. Large area radiation source for water and wastewater treatment

    Science.gov (United States)

    Mueller, Michael T.; Lee, Seungwoo; Kloba, Anthony; Hellmer, Ronald; Kumar, Nalin; Eaton, Mark; Rambo, Charlotte; Pillai, Suresh

    2011-06-01

    There is a strong desire for processes that improve the safety of water supplies and that minimize disinfection byproducts. Stellarray is developing mercury-free next-generation x-ray and UV-C radiation sources in flat-panel and pipe form factors for water and wastewater treatment applications. These new radiation sources are designed to sterilize sludge and effluent, and to enable new treatment approaches to emerging environmental concerns such as the accumulation of estrogenic compounds in water. Our UV-C source, based on cathodoluminescent technology, differs significantly from traditional disinfection approaches using mercury arc lamps or UV LEDs. Our sources accelerate electrons across a vacuum gap, converting their energy into UV-C when striking a phosphor, or x-rays when striking a metallic anode target. Stellarray's large area radiation sources for wastewater treatment allow matching of the radiation source area to the sterilization target area for maximum coverage and improved efficiency.

  12. A method of reducing background radiance for emissivity-compensated radiation thermometry of silicon wafers.

    Science.gov (United States)

    Iuchi, T; Toyoda, Y; Seo, T

    2013-02-01

    We studied the spectral and directional emissivities of silicon wafers using an optical polarization technique. Based on simulation and experimental results, we developed two radiation thermometry methods for silicon wafers: one is based on the polarized emissivity-invariant condition and the other is based on the relationship between the ratio of the p- and s-polarized radiance and the polarized emissivity. These methods can be performed at temperatures above 600 °C and over a wide wavelength range (0.9-4.8 μm), irrespective of the dielectric film thickness and the substrate resistivity, which depends on the dopant concentration. The temperature measurements were estimated to have expanded uncertainties (k = 2) of less than 5 °C. With a view to practically applying these methods, we investigated a method to reduce the intense background radiance produced by high-intensity heating lamps. We found that the background radiance can be greatly reduced by using a radiometer that is sensitive to wavelengths of 4.5 or 4.8 μm and suitable geometrical arrangements of a quartz plate. This opens up the possibility of using the two proposed radiation thermometry methods in practical applications.

  13. Estimation of collective effective dose due to natural background radiation in Egypt

    Science.gov (United States)

    Henaish, B. A.; Tawfik, A. A.; Abu Zaid, H.; Gomaa, M. A.

    1994-07-01

    During the last few years, worldwide attention has been directed towards the estimation of natural background radiation levels. Several environmental monitoring networks have been established for systematic data collection and exchange of information.In the present study, measurements of annual effective dose from terrestrial γ-rays are carried out at pre-selected sites within several Egyptian governorates by using a calibrated gas-filled GM-detector connected to a microcomputer system. Contribution of the secondary cosmic-rays, which is of prime importance at sea level, is achieved by carrying out computation based on theoretical considerations.Terrestrial effective dose in Egypt is found to be between 106 and 371 μSv/yr, meanwhile the computed cosmic rays contribution is 260-296 μSv/yr. Accordingly, the annual collective effective dose due to natural background radiation is about 27,253 Man Sv for the last Egyptian population count (1989) considering 0.8 and 0.2 indoor and outdoor occupancy factors.

  14. The Cosmic Microwave Background Radiation-A Unique Window on the Early Universe

    Science.gov (United States)

    Hinshaw, Gary

    2010-01-01

    The cosmic microwave background radiation is the remnant heat from the Big Bang. It provides us with a unique probe of conditions in the early universe, long before any organized structures had yet formed. The anisotropy in the radiation's brightness yields important clues about primordial structure and additionally provides a wealth of information about the physics of the early universe. Within the framework of inflationary dark matter models, observations of the anisotropy on sub-degree angular scales reveals the signatures of acoustic oscillations of the photon-baryon fluid at a redshift of 11 00. Data from the first seven years of operation of the Wilkinson Microwave Anisotropy Probe (WMAP) satellite provide detailed full-sky maps of the cosmic microwave background temperature and polarization anisotropy. Together, the data provide a wealth of cosmological information, including the age of the universe, the epoch when the first stars formed, and the overall composition of baryonic matter, dark matter, and dark energy. The results also provide constraints on the period of inflationary expansion in the very first moments of time. WMAP, part of NASA's Explorers program, was launched on June 30, 2001. The WMAP satellite was produced in a partnership between the Goddard Space Flight Center and Princeton University. The WMAP team also includes researchers at the Johns Hopkins University; the Canadian Institute of Theoretical Astrophysics; University of Texas; Oxford University; University of Chicago; Brown University; University of British Columbia; and University of California, Los Angeles.

  15. A method of reducing background radiance for emissivity-compensated radiation thermometry of silicon wafers.

    Science.gov (United States)

    Iuchi, T; Toyoda, Y; Seo, T

    2013-02-01

    We studied the spectral and directional emissivities of silicon wafers using an optical polarization technique. Based on simulation and experimental results, we developed two radiation thermometry methods for silicon wafers: one is based on the polarized emissivity-invariant condition and the other is based on the relationship between the ratio of the p- and s-polarized radiance and the polarized emissivity. These methods can be performed at temperatures above 600 °C and over a wide wavelength range (0.9-4.8 μm), irrespective of the dielectric film thickness and the substrate resistivity, which depends on the dopant concentration. The temperature measurements were estimated to have expanded uncertainties (k = 2) of less than 5 °C. With a view to practically applying these methods, we investigated a method to reduce the intense background radiance produced by high-intensity heating lamps. We found that the background radiance can be greatly reduced by using a radiometer that is sensitive to wavelengths of 4.5 or 4.8 μm and suitable geometrical arrangements of a quartz plate. This opens up the possibility of using the two proposed radiation thermometry methods in practical applications. PMID:23464239

  16. Primordial Gravitational Waves and Rescattered Electromagnetic Radiation in the Cosmic Microwave Background

    Science.gov (United States)

    Kim, Dong-Hoon; Trippe, Sascha

    2016-10-01

    Understanding the interaction of primordial gravitational waves (GWs) with the Cosmic Microwave Background (CMB) plasma is important for observational cosmology. In this article, we provide an analysis of an apparently as-yet-overlooked effect. We consider a single free electric charge and suppose that it can be agitated by primordial GWs propagating through the CMB plasma, resulting in periodic, regular motion along particular directions. Light reflected by the charge will be partially polarized, and this will imprint a characteristic pattern on the CMB. We study this effect by considering a simple model in which anisotropic incident electromagnetic (EM) radiation is rescattered by a charge sitting in spacetime perturbed by GWs, and becomes polarized. As the charge is driven to move along particular directions, we calculate its dipole moment to determine the leading-order rescattered EM radiation. The Stokes parameters of the rescattered radiation exhibit a net linear polarization. We investigate how this polarization effect can be schematically represented out of the Stokes parameters. We work out the representations of gradient modes (E-modes) and curl modes (B-modes) to produce polarization maps. Although the polarization effect results from GWs, we find that its representations, the E- and B-modes, do not practically reflect the GW properties such as strain amplitude, frequency, and polarization states.

  17. Radiative transfer in a clumpy universe; 2, the ultraviolet extragalactic background

    CERN Document Server

    Haardt, F; Haardt, Francesco; Madau, Piero

    1995-01-01

    We present a detailed calculation of the propagation of AGN-like ionizing radiation through the intergalactic space. We model the ionization state of absorbing clouds, and show that the universe will be more opaque above 4\\,Ryd than previously estimated. Singly ionized helium in \\Lya forest clouds and Lyman-limit systems is found to be very efficient in reprocessing soft X-ray, helium-ionizing photons into ultraviolet, hydrogen-ionizing ones. We demonstrate that a significant fraction of the absorbed primary photons (emitted, e.g., by quasar sources) will be reradiated by the photoionized gas through \\Lya line emission, two-photon continuum, and recombination continuum radiation. In the light of new data and recent studies, we also reassess the contribution of the QSOs observed in optical surveys to the UV extragalactic background, and find that the stochastic reprocessing of quasar Lyman continuum radiation by hydrogen and helium along the line of sight will significantly affect the amplitude spectral shape,...

  18. Measured Radiation and Background Levels During Transmission of Megawatt Electron Beams Through Millimeter Apertures

    International Nuclear Information System (INIS)

    We report measurements of photon and neutron radiation levels observed while transmitting a 0.43 MW electron beam through millimeter-sized apertures and during beam-off, but accelerating gradient RF-on, operation. These measurements were conducted at the Free-Electron Laser (FEL) facility of the Jefferson National Accelerator Laboratory (JLab) using a 100 MeV electron beam from an energy-recovery linear accelerator. The beam was directed successively through 6 mm, 4 mm, and 2 mm diameter apertures of length 127 mm in aluminum at a maximum current of 4.3 mA (430 kW beam power). This study was conducted to characterize radiation levels for experiments that need to operate in this environment, such as the proposed DarkLight Experiment. We find that sustained transmission of a 430 kW continuous-wave (CW) beam through a 2 mm aperture is feasible with manageable beam-related backgrounds. We also find that during beam-off, RF-on operation, multipactoring inside the niobium cavities of the accelerator cryomodules is the primary source of ambient radiation when the machine is tuned for 130 MeV operation

  19. Genetic background modulates lncRNA-coordinated tissue response to low dose ionizing radiation

    International Nuclear Information System (INIS)

    Long noncoding RNAs (lncRNAs) are emerging as key regulators of diverse cell functions and processes. However, the relevance of lncRNAs in the cell and tissue response to ionizing radiation has not yet been characterized. Here we used microarray profiling to determine lncRNA and mRNA expression in mammary glands of BALB/c and SPRET/EiJ mice after low-dose ionizing radiation (LDIR) exposure. We found that unirradiated mammary tissues of these strains differed significantly in baseline expressions of 290 lncRNAs. LDIR exposure (10 cGy) induced a significant change in the expression of many lncRNAs. The vast majority of lncRNAs identified to be differentially expressed after LDIR in either BALB/c or SPRET/EiJ had a significantly correlated expression pattern with at least one LDIR responsive mRNA. Functional analysis revealed that the response to LDIR in BALB/c mice is highly dynamic with enrichment for genes involved in tissue injury, inflammatory responses, and mammary gland development at 2, 4, and 8 weeks after LDIR, respectively. Our study demonstrates that genetic background strongly influences the expression of lncRNAs and their response to radiation and that lncRNAs may coordinate the tissue response to LDIR exposure via regulation of coding mRNAs

  20. Criteria for the Formation of Population III Objects in the Ultraviolet Background Radiation

    CERN Document Server

    Kitayama, T; Umemura, M; Ikeuchi, S

    2001-01-01

    We explore possibilities of collapse and star formation in Population III objects exposed to the external ultraviolet background (UVB) radiation. Assuming spherical symmetry, we solve self-consistently radiative transfer of photons, non-equilibrium H2 chemistry, and gas hydrodynamics. Although the UVB does suppress the formation of low mass objects, the negative feedback turns out to be weaker than previously suggested. In particular, the cut-off scale of collapse drops significantly below the virial temperature 10^4 K at weak UV intensities, due to both self-shielding of the gas and H2 cooling. Clouds above this cut-off tend to contract highly dynamically, further promoting self-shielding and H2 formation. For plausible radiation intensities and spectra, the collapsing gas can cool efficiently to temperatures well below 10^4 K before rotationally supported and the final H2 fraction reaches 10^{-3}. Our results imply that star formation can take place in low mass objects collapsing in the UVB. The threshold b...

  1. Unique signatures of natural background radiation on human Y chromosomes from Kerala, India.

    Directory of Open Access Journals (Sweden)

    Sanjay Premi

    Full Text Available BACKGROUND: The most frequently observed major consequences of ionizing radiation are chromosomal lesions and cancers, although the entire genome may be affected. Owing to its haploid status and absence of recombination, the human Y chromosome is an ideal candidate to be assessed for possible genetic alterations induced by ionizing radiation. We studied the human Y chromosome in 390 males from the South Indian state of Kerala, where the level of natural background radiation (NBR is ten-fold higher than the worldwide average, and that from 790 unexposed males as control. RESULTS: We observed random microdeletions in the Azoospermia factor (AZF a, b and c regions in >90%, and tandem duplication and copy number polymorphism (CNP of 11 different Y-linked genes in about 80% of males exposed to NBR. The autosomal homologues of Y-linked CDY genes largely remained unaffected. Multiple polymorphic copies of the Y-linked genes showing single Y-specific signals suggested their tandem duplication. Some exposed males showed unilocus duplication of DAZ genes resulting in six copies. Notably, in the AZFa region, approximately 25% of exposed males showed deletion of the DBY gene, whereas flanking genes USP9Y and UTY remained unaffected. All these alterations were detected in blood samples but not in the germline (sperm samples. CONCLUSIONS: Exposure to high levels of NBR correlated with several interstitial polymorphisms of the human Y chromosome. CNPs and enhanced transcription of the SRY gene after duplication are envisaged to compensate for the loss of Y chromosome in some cells. The aforesaid changes, confined to peripheral blood lymphocytes, suggest a possible innate mechanism protecting the germline DNA from the NBR. Genome analysis of a larger population focusing on greater numbers of genes may provide new insights into the mechanisms and risks of the resultant genetic damages. The present work demonstrates unique signatures of NBR on human Y chromosomes

  2. A measurement of the low frequency spectrum of the cosmic microwave background radiation

    International Nuclear Information System (INIS)

    As part of a larger effort to measure the spectrum of the Cosmic Background Radiation (CBR) at low frequencies, the intensity of the CBR has been measured at a frequency of 1.410 GHz. The measurement was made by comparing the power received from the sky with the power received from a specially designed cooled calibration target with known properties. Sources of radiation other than the CBR were then identified and subtracted to calculate the antenna temperature of the CBR at 1.410 GHz. The instrument used to measure the CBR was a total-power microwave radiometer with a 25 MHz bandwidth centered at 1.410 GHz. The radiometer had a noise temperature of 80 K, and sufficient data were taken that radiometer noise did not contribute significantly to the total measurement error. The sources of error were predominantly systematic in nature, and the largest error was due to uncertainty in the reflection characteristics of the cold-load calibrator. Identification and subtraction of signals from the Galaxy (0.7 K) and the Earth's atmosphere (0.8 K) were also significant parts of the data reduction and error analysis. The brightness temperature of the Cosmic Background Radiation at 1.410 GHz is 222. +- 0.55 Kelvin. The spectrum of the CBR, as determined by this measurement and other published results, is consistent with a blackbody spectrum of temperature 2.741 +- 0.016. Constraints on the amount by which the CBR spectrum deviates from Planck spectrum are used to place limits on energy releases early in the history of the universe. 55 refs., 25 figs., 8 tabs

  3. Background levels and radiation dose yield of o-tyrosine in chicken meat

    International Nuclear Information System (INIS)

    The measurement of o-tyrosine levels in poultry meat is a potential method for postirradiation dosimetry of poultry. The validity of using o-tyrosine for this purpose has not yet been established. As part of the validation process, the o-tyrosine content in unirradiated chicken meat, the radiation dose response curve, and the effects of postirradiation storage on o-tyrosine levels are examined. In 18 individual samples, the mean background level of o-tyrosine was 0.18 +/- 0.11 ppm (wet weight, 70% moisture), and the most frequent background level (60% of the cases) was between 0.05 and 0.15 ppm (wet weight, 70% moisture). In pooled samples of 10 chickens, the mean background level was 0.12 +/- 0.03 ppm (wet weight, 70% moisture). The levels were not significantly affected by storage at 5 degrees C (7 d) or by freezing the sample. The radiation dose response curve was linear within the dose range studied (0 to 10 kGy), with a slope of 0.127 + 0.003 ppm (wet weight)/kGy. Although there was some variation in the intercept (0.132 + 0.013), the slope was the same in all samples tested. Postirradiation storage at either 4 or 8 degrees C until spoilage did not affect the levels of o-tyrosine. These data indicate that o-tyrosine level may be useful for determining the absorbed dose in chicken meat gamma-irradiated to doses greater than 0.6 kGy. Further validation studies are continuing

  4. [Radiation Environment Study of Near Space in China Area].

    Science.gov (United States)

    Mei, Xiao-dong; Sun, Ji-lin; Li, Zheng-qiang; Chen, Xing-feng; Xing, Jin; Xu, Hua; Qie, Li-li; Lü, Yang; Li, Yang; Liu, Li

    2016-03-01

    Aerospace activity in near space (20-50 km) has become a research hotspot for aviation big countries worldwide. Solar radiation study, as the prerequisite to carry out aerospace activity, is facing the barrier of lacking of observation in near space layer. Ozone is the most important factor that affects radiation value in this layer. Based on ECMWF reanalysis data, this input key parameter and its horizontal, vertical and temporal characteristics are analyzedwith results showing obvious regional features in temporal-spatial distribution and varieties. With meteorological data and surface parameters, near space over China is divided into 5 parts. Key factors' value is confirmed over each division. With SBDART radiation transfer model, solar radiation and ultraviolet radiation simulation in near space are conducted separately. Results show that it is influenced by latitude, total ozone and its vertical distribution, radiation varies under complex rules. The average year and monthly solar radiation strengthens changes with latitude reduction, while annual range changes reversely. Air absorbing is related to latitude and land-sea contrast and shows different values and seasonal variations. The ultraviolet radiation over South China Sea reaches its maximum value and minimum annual range, as well as minimum monthly range with value strengthening in summer and weakening in winter. In other areas radiation increases in summer while weakens in winter, monthly range shows double peaks with higher value in spring and autumn, lower in summer and winter. Air absorption in ultraviolet radiation is influenced by multiple factors, vertical varieties over areas besides South China Sea enhance in summer time. The vertical changes of monthly ranges affected by air absorption show consistence in higher and lower layer in June and July, while in other months ranges are bigger in higher layer. PMID:27400492

  5. Definition of priority areas for monitoring of gamma radiation on the surroundings of the CDTN installations

    International Nuclear Information System (INIS)

    To demonstrate compliance with regulations and legal requirements, the Environmental Monitoring Program of the - Development Center of Nuclear Technology - PMA/CDTN was created in 1985. However, at that time, no data was available to represent the background - the natural level for the pre operational period in terms of Gamma radiation. Thus, the lowest value obtained among the sentinel point sites from the early period of the environmental monitoring was adopted as benchmark. As these measurements were performed by procedures and conditions other than that currently in use, this reference value may not correspond to reality. Therefore, it may not be appropriate to use it as background in assessing the possible environmental impact generated by the activities of the facilities. The goal of this study is to propose an area of geographic distribution for 12 monitoring points, outside the CDTN facilities, so that the real natural Gamma radiation levels can be accurately measured without the interference of the radioactivity levels originating from the institution, enabling the determination of the most representative values of the natural gamma radiation in the area. This survey of the natural radiation determination in the study area, with the use of modern equipment and the application of methodology taking into account historical data, as well the geological, geomorphological and geographical studies of the region, pointed to an average background value of 0.095μSv/h. This result, together with other studies, indicated a maximum range of 25m beyond the CDTN boundaries to distribute the monitoring points. (author)

  6. The definition analyses of radiation temperature measurement area

    Institute of Scientific and Technical Information of China (English)

    Fu Tairan; Cheng Xiaofang; Zhong Maohua

    2008-01-01

    In the research of primary spectrum pyrometry, this paper discussed the definition problem of radiation tem-perature measurement area based on the measurement coordinates. For the linear spectrum emissivity model and im-proved monotonic spectrum emissivity model, the characteristics of radiation temperature measurement area restricted by the measurement coordinates were theoretically analyzed, through the investigations of the temperature and emissivity co-ordinate axes. Choosing the specific primary spectrum pyrometer as an example in applications, the theoretical area of radiation temperature measurement of this pyrometer was given and it was verified through blackbody experiments. The discussions of this paper will provide the necessary foundation for the theory research development of primary spectrum pyrometry and the realization of technical applications.

  7. A New Upper Limit on the Polarization of the Cosmic Microwave Background Radiation

    CERN Document Server

    O'Dell, C

    2002-01-01

    The Cosmic Microwave Background Radiation (CMB) is an invaluable probe of the conditions of the early universe. Recent measurements of its spatial anisotropy have allowed accurate determinations of several fundamental cosmological parameters, such as the curvature of the universe, the shape of the spectrum of primordial density fluctuations, and the contribution of baryons, dark matter, and dark energy to the overall energy density of the universe. In addition to being spatially non-uniform, the CMB is theorized to be slightly polarized. Measurements of this polarization, particularly at large angular scales, have the potential to provide information on primordial gravitational waves, theories of inflation, and the ionization history of the universe, as well as help further constrain cosmological parameters. Polarization has not yet been detected in the CMB. This thesis describes a recent search for CMB polarization at large angular scales, conducted in the spring of 2000 at the University of Wisconsin-Madiso...

  8. Radiation induced mutants in elite genetic background for the augmentation of genetic diversity

    International Nuclear Information System (INIS)

    Rice (Oryza sativa L.), an important food crop for India, shows large genetic diversity. However, despite the large genetic resource, high genetic similarity is reported in cultivated varieties indicating genetic erosion. Radiation induced mutations provide genetic variability in elite background. In the present study, twenty gamma ray induced mutants of rice variety WL112 (carrying sd-1 semi-dwarfing gene) were analysed for genetic diversity using microsatellite markers. The high range of genetic diversity among mutants indicated that the mutants possess potential for enhancing variability in rice. Cluster analysis showed presence of five clusters having small sub-clusters. Earliness, semi-dwarf stature or resistance to blast disease observed among the mutants showed that these will be useful in breeding programmes. (author)

  9. Measurement of the large-scale anisotropy of the cosmic background radiation at 3mm

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, G.L.

    1983-12-01

    A balloon-borne differential radiometer has measured the large-scale anisotropy of the cosmic background radiation (CBR) with high sensitivity. The antenna temperature dipole anistropy at 90 GHz (3 mm wavelength) is 2.82 +- 0.19 mK, corresponding to a thermodynamic anistropy of 3.48 +- mK for a 2.7 K blackbody CBR. The dipole direction, 11.3 +- 0.1 hours right ascension and -5.7/sup 0/ +- 1.8/sup 0/ declination, agrees well with measurements at other frequencies. Calibration error dominates magnitude uncertainty, with statistical errors on dipole terms being under 0.1 mK. No significant quadrupole power is found, placing a 90% confidence-level upper limit of 0.27 mK on the RMS thermodynamic quadrupolar anistropy. 22 figures, 17 tables.

  10. An Upper Limit on the Finescale Anisotropy of the Cosmic Background Radiation at 800-MICRONS

    Science.gov (United States)

    Church, S. E.; Lasenby, A. N.; Hills, R. E.

    1993-04-01

    In some models of the early Universe, radiation is reprocessed into the submillimetre and far-infrared by high-redshift dust, without violating COBE limits on the CBR spectrum, but producing secondary anisotropies which should be detectable with ground-based submillimetre telescopes. We describe an attempt to measure these anisotropies at 800 microns using the JCMT. A careful analysis to reduce position-dependent systematics was carried out and we show that, for this experiment, chopping the telescope beam in azimuth rather than RA produces lower systematics. Bayesian likelihood analysis is then used to set an upper limit on CBR fluctuations of {DELTA} T/T Kreysa & Chini in 1988 with the IBM 30-m telescope at 1300 microns are reanalysed in the same way to enable a comparison to be made. The results are used to set limits on the generation of cosmic backgrounds from primeval dust.

  11. Tools for forming strategies for remediation of forests and park areas in northern Europe after radioactive contamination: background and techniques

    International Nuclear Information System (INIS)

    This report compiles background information that can be used in planning appropriate countermeasures for forest and park areas in Denmark, Sweden, Finland and Norway, in case a nuclear accident results in large-scale contamination of forests. The information is formulated to inform the forestry sector and radiation protection experts about the practicality of both forest management techniques and mechanical cleanup methods, for use in their planning of specific strategies that can lead to an optimal use of contaminated forests. Decisions will depend on the site and the actual situation after radioactive deposition to forested areas, but the report provides background information from investigations performed before an accident occurs that will make the process more effective. The report also discusses the radiological consequences of producing energy from biomass contaminated by a major nuclear accident, both in the context of normal bio-fuel energy production and as a means of reducing potentially severe environmental problems in the forest by firing power plants with highly contaminated forest biomass. (au)

  12. Tools for forming strategies for remediation of forests and park areas in northern Europe after radioactive contamination: background and techniques

    Energy Technology Data Exchange (ETDEWEB)

    Hubbard, L. [Swedish Radiation Protection Authority, SSI (Sweden); Rantavaara, A. [Radiation and Nuclear Safety Autority, STUK (Finland); Andersson, K. [Risoe National Lab., Roskilde (Denmark); Roed, J. [Risoe National Lab., Roskilde (Denmark)

    2002-01-01

    This report compiles background information that can be used in planning appropriate countermeasures for forest and park areas in Denmark, Sweden, Finland and Norway, in case a nuclear accident results in large-scale contamination of forests. The information is formulated to inform the forestry sector and radiation protection experts about the practicality of both forest management techniques and mechanical cleanup methods, for use in their planning of specific strategies that can lead to an optimal use of contaminated forests. Decisions will depend on the site and the actual situation after radioactive deposition to forested areas, but the report provides background information from investigations performed before an accident occurs that will make the process more effective. The report also discusses the radiological consequences of producing energy from biomass contaminated by a major nuclear accident, both in the context of normal bio-fuel energy production and as a means of reducing potentially severe environmental problems in the forest by firing power plants with highly contaminated forest biomass. (au)

  13. Measurement of anisotropy in the cosmic background radiation on a large angular scale at 33 GHz

    International Nuclear Information System (INIS)

    Results of a measurement of anisotropy in the 3 0K cosmic background radiation on a large-angular-scale are presented. Observations were carried out with a dual-antenna microwave radiometer operating at 33 GHz (0.89 cm wavelength) flown on board a U-2 aircraft to 20-km altitude. In eleven flights, between December 1976 and May 1978, the radiometer measured differential intensity between pairs of directions distributed over most of the northern celestial hemisphere with an rms sensitivity of +- 46m0K/√Hz. The measurements show clear evidence of anisotropy that is readily interpreted as due to the motion of the earth relative to the sources of the radiation; the anisotropy is well fit by a cosine distribution of amplitude 3.61 +- 0.54 millireverse arrowreverse arrow-degrees Kelvin (m0K), one part in 800 of 30K, implying a velocity of 361 +- 54 km/sec toward the direction 11.23 +- 0.46 hours right ascension, and 19.0 +- 7.50 declination. A simultaneous fit to a combined hypothesis of dipole (cos theta) and quadrupole (cos2 theta) angular distributions places a 1 m0K limit on the amplitude of most components of quadruple anisotropy with 90% confidence. Additional analysis places a 0.5 m 0K limit on uncorrelated fluctuations (sky-roughness) in the 30K background on an angular scale of the antenna beam width, about 70. This thesis describes the equipment development through three engineering flights and the data acquisition in eleven additional flights. The astrophysical results are then presented from the statistical analysis of the reduced data

  14. Calibration of low-frequency radio telescopes using the galactic background radiation

    Science.gov (United States)

    Dulk, G. A.; Erickson, W. C.; Manning, R.; Bougeret, J.-L.

    2001-01-01

    We consider the calibration of flux densities of radio bursts from decametric to kilometric wavelengths using ground-based and space-based data. The method we derive is applicable to low-frequency radio telescopes where galactic background radiation is the principal contribution to system temperature. It can be particularly useful for telescopes of low angular resolution observing spectra of radio bursts from the Sun and the planets because absolute calibration of these telescopes is very difficult with conventional techniques. Here we apply the method to observations from about 7 to 47 MHz that were made on the ground with the Bruny Island Radio Spectrometer located in Tasmania, Australia, and those from about 20 kHz to 13.8 MHz were made with the radio experiment WAVES on the WIND spacecraft. The spectrum of the galactic background radiation from 30 MHz has been carefully measured with low-resolution telescopes, starting more than a decade ago. We use this known spectrum to calibrate both BIRS and WAVES on an absolute scale. The accuracy we achieve is about a factor of two, whereas the flux densities of solar and planetary radio sources vary by many orders of magnitude. Our method permits inter-calibration of ground-based and space-based observations, and allows corrections to be made for instrumental uncertainties on both radio experiments. In addition, on the ground, it allows the spectra to be corrected for ionospheric absorption and partial ground reflections. As an application we show the spectrum of a solar type III burst observed from 47 MHz to 20 kHz. Its flux density was largest, S~ 10-17 W m-2 Hz-1, at about 3 MHz, while at 60 kHz and at 47 MHz it was lower by a factor of about 300.

  15. Observing the Cosmic Microwave Background Radiation: A Unique Window on the Early Universe

    Science.gov (United States)

    Hinshaw, Gary; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    The cosmic microwave background radiation is the remnant heat from the Big Bang. It provides us with a unique probe of conditions in the early universe, long before any organized structures had yet formed. The anisotropy in the radiation's brightness yields important clues about primordial structure and additionally provides a wealth of information about the physics,of the early universe. Within the framework of inflationary dark matter models observations of the anisotropy on sub-degree angular scales will reveal the signatures of acoustic oscillations of the photon-baryon fluid at a redshift of approx. 1100. The validity of inflationary models will be tested and, if agreement is found, accurate values for most of the key cosmological parameters will result. If disagreement is found, we will need to rethink our basic ideas about the physics of the early universe. I will present an overview of the physical processes at work in forming the anisotropy and discuss what we have already learned from current observations. I will conclude with a brief overview of the recently launched Microwave Anisotropy Probe (MAP) mission which will observe the anisotropy over the full sky with 0.21 degree angular resolution. At the time of this meeting, MAP will have just arrived at the L2 Lagrange point, marking the start of its observing campaign. The MAP hardware is being produced by Goddard in partnership with Princeton University.

  16. Cosmic background radiation in the vicinity of a Schwarzschild black hole: No classic firewall

    Science.gov (United States)

    Wielgus, M.; Ellis, G. F. R.; Vincent, F. H.; Abramowicz, M. A.

    2014-12-01

    The cosmic blackbody background radiation pervades the entire Universe, and so falls into every astrophysical black hole. The blueshift of the infalling photons, measured by a static observer, is infinite at the event horizon. This raises a question as to whether a "firewall" of high energy density may form just outside the horizon, or whether the effect can be attributed exclusively to a singular behavior of the static observer's frame at the horizon. In principle, the presence of such a firewall may alter the motion of the infalling matter, influence the black hole evolution, or even invalidate the vacuum Einstein field equation solution as a realistic approximation for black holes. In this paper we show by means of analytic calculations that all these effects indeed exist, but their magnitude is typically negligibly small, even though the matter stress tensor is divergent in the static frame at r =2 M . That is not surprising because of the divergent relation of that frame to a freely falling frame as r →2 M ; however, it represents a kind of classical analogue for the black hole complementarity principle that has been proposed for quantum effects near a black hole. What is perhaps more surprising is the divergence of the radiation stress tensor for massive particles moving on circular geodesic orbits for values of r approaching r =3 M . However such orbits will not occur for infalling matter in realistic accretion discs.

  17. Semi-numeric simulations of helium reionization and the fluctuating radiation background

    CERN Document Server

    Dixon, Keri L; Mesinger, Andrei

    2013-01-01

    Recent He II Lyman-alpha forest observations from 2.0 2.7. These results point to a fluctuating He-ionizing background, which may be due to the end of helium reionization of this era. We present a fast, semi-numeric procedure to approximate detailed cosmological simulations. We compute the distribution of dark matter halos, ionization state of helium, and density field at z = 3 in broad agreement with recent simulations. Given our speed and flexibility, we investigate a range of ionizing source and active quasar prescriptions. Spanning a large area of parameter space, we find order-of-magnitude fluctuations in the He II ionization rate in the post-reionization regime. During reionization, the fluctuations are even stronger and develop a bimodal distribution, in contrast to semi-analytic models and the hydrogen equivalent. These distributions indicate a low-level ionizing background even at significant He II fractions.

  18. Polychlorinated biphenyls in surface soil in urban and background areas of Mongolia

    International Nuclear Information System (INIS)

    Polychlorinated biphenyls (PCBs) were measured in soil in some industrial towns (Ulaanbaatar, Suhbaatar, Erdenet, Darhan, Tsetserleg, Hovd, Ulaangom, Altay, Bayanhongor, Arvayheer, Saynshand, Choybalsan) and in background and rural areas of Mongolia. The average sum of all investigated PCB congeners in soil of Mongolia comes to 7.4 ng/g dry weight (DW) and varies from 0.53 ng/g DW till 114 ng/g DW. PCB levels in soil from towns are significantly higher than those in soil from background and rural areas. The PCB homological composition in soil sampled in highly-PCB-polluted sites is similar to the PCB homological pattern in Sovol and Aroclor 1254. Significant correlation between soil organic carbon and low chlorinated PCB both for towns and background sites was found. Significant differences in PCB means in soil in different natural zones were found. -- Highlights: •First study to measure PCBs in surface soil sampled throughout Mongolia. •The PCB patterns in polluted soil were similar to those in Sovol or Aroclor 1254. •Significant differences in PCB means in soil in different natural zones were found. -- Polychlorinated biphenyls were measured in soils throughout Mongolia

  19. Use of legal reserve areas as geochemical background in hydrosedimentology studies¹

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Juchen

    2014-12-01

    Full Text Available In hydrosedimentology studies the determination of the trace element concentrations at the study site is imperative, since this background can be used to assess the enrichment of sediments with these elements. This enrichment can be the result of the natural process of geological formation or of anthropogenic activities. In the latter case, guidelines are used to indicate the concentrations at which trace elements cause ecotoxicity effects on the environment. Thus, this study used legal reserve areas in the municipality of Toledo, PR, where natural forests are maintained, with no or minimal human interference to establish background levels. The results of atomic emission spectrometry with inductively coupled argon plasma showed that the legal reserves have lower levels of trace elements than other theoretical references, but equivalent concentrations to the safety levels recommended by international guidelines. It was concluded that determining values is fundamental to recommend this background as scientific database for research in the area of hydrosedimentology of this site and also as a way of environmental management of the watershed of this municipality.

  20. LSO background radiation as a transmission source using time of flight

    International Nuclear Information System (INIS)

    LSO scintillators (Lu2Sio5:Ce) have a background radiation which originates from the isotope Lu-176 that is present in natural occurring lutetium. The decay that occurs in this isotope is a beta decay that is in coincidence with cascade gamma emissions with energies of 307,202 and 88 keV. The coincidental nature of the beta decay with the gamma emissions allow for separation of emission data originating from a positron annihilation event from transmission type data from the Lu-176 beta decay. By using the time of flight information, and information of the chord length between two LSO pixels in coincidence as a result of a beta emission and emitted gamma, a second time window can be set to observe transmission events simultaneously to emission events. Using the time when the PET scanner is not actively acquiring positron emission data, a continuous blank can be acquired and used to reconstruct a transmission image. With this blank and the measured transmission data, a transmission image can be reconstructed. This reconstructed transmission image can be used to perform emission data corrections such as attenuation correction and scatter corrections or starting images for algorithms that estimate emission and attenuation simultaneously. It is observed that the flux of the background activity is high enough to create useful transmission images with an acquisition time of 10 min. (paper)

  1. Many body heat radiation and heat transfer in the presence of a non-absorbing background medium

    CERN Document Server

    Müller, Boris; Antezza, Mauro; Emig, Thorsten; Krüger, Matthias

    2016-01-01

    Heat radiation and near-field radiative heat transfer can be strongly manipulated by adjusting geometrical shapes, optical properties, or the relative positions of the objects involved. Typically these objects are considered as embedded in vacuum. By applying the methods of fluctuational electrodynamics, we derive general closed-form expressions for heat radiation and heat transfer in a system of $N$ arbitrary objects embedded in a passive non-absorbing background medium. Taking into account the principle of reciprocity, we explicitly prove the symmetry and positivity of transfer in any such system. Regarding applications, we find that the heat radiation of a sphere as well as the heat transfer between two parallel plates is strongly enhanced by the presence of a background medium. Regarding near- and far-field transfer through a gas like air, we show that a microscopic model (based on gas particles) and a macroscopic model (using a dielectric contrast) yield identical results. We also compare the radiative t...

  2. Ozone vertical flux within the lower troposphere over background areas of west Siberia

    Science.gov (United States)

    Antokhin, P. N.; Antokhina, O. Yu.; Belan, S. B.; Belan, B. D.; Kozlov, A. V.; Krasnov, O. A.; Pestunov, D. A.

    2014-11-01

    In this paper the results of the vertical ozone flux profiles calculated within the lower troposphere over background area of west Siberia are presented. The data on the vertical distribution of the ozone and meteorological parameters derived from AN-2 aircraft measurements supplemented by radiosonde launches. Profiles of turbulent diffusion coefficient were calculated based on "K-theory" with the use of nonlocal closure scheme - "Troen and Mahrt". Calculations confirmed earlier findings that the formation of the daytime ozone maximum in the atmospheric boundary layer occurs due to its photochemical production from precursors.

  3. Comparing Background and Recent Erosion Rates in Degraded Areas of Southeastern Brazil

    Science.gov (United States)

    Fernandes, N.; Bierman, P. R.; Sosa-Gonzalez, V.; Rood, D. H.; Fontes, R. L.; Santos, A. C.; Godoy, J. M.; Bhering, S.

    2014-12-01

    Soil erosion is a major problem in northwestern Rio de Janeiro State where, during the last three centuries, major land-use changes took place, associated with the replacement of the original rainforest by agriculture and grazing. The combination of steep hillslopes, erodible soils, sparse vegetation, natural and human-induced fires, as well as downslope ploughing, led to an increase in surface runoff and surface erosion on soil-mantled hillslopes; together, these actions and responses caused a decline in soil productivity. In order to estimate changes in erosion rates over time, we compared erosion rates measured at different spatial and temporal scales, both background (natural) and short-term (human-induced during last few decades). Background long-term erosion rates were measured using in-situ produced cosmogenic 10Be in the sand fraction quartz of active river channel sediment in four basins in the northwestern portion of Rio de Janeiro State. In these basins, average annual precipitation varies from 1,200 to 1,300 mm, while drainage areas vary from 15 to 7,200 km2. Short-term erosion rates were measured in one of these basins from fallout 210Pb in soil samples collected along a hillslope transect located in an abandoned agriculture field. In this transect, 190 undisturbed soil samples (three replicates) were collected from the surface to 0.50 m depth (5 cm vertical intervals) in six soil pits. 10Be average background, basin-wide, erosion rates in the area are ~ 13 m/My; over the last decades, time-integrated (210Pb) average hillslope erosion rates are around 1450 m/Myr, with maximum values at the steepest portion of convex hillslopes of about 2000 m/Myr. These results suggest that recent hillslope erosion rates are about 2 orders of magnitude above background rates of sediment generation integrated over many millennia. This unsustainable rate of soil loss has severely decreased soil productivity eventually leading to the abandonment of farming activities in

  4. Space weather circulation model of plasma clouds as background radiation medium of space environment.

    Science.gov (United States)

    Kalu, A. E.

    A model for Space Weather (SW) Circulation with Plasma Clouds as background radiation medium of Space Environment has been proposed and discussed. Major characteristics of the model are outlined and the model assumes a baroclinic Space Environment in view of observed pronounced horizontal electron temperature gradient with prevailing weak vertical temperature gradient. The primary objective of the study is to be able to monitor and realistically predict on real- or near real-time SW and Space Storms (SWS) affecting human economic systems on Earth as well as the safety and Physiologic comfort of human payload in Space Environment in relation to planned increase in human space flights especially with reference to the ISS Space Shuttle Taxi (ISST) Programme and other prolonged deep Space Missions. Although considerable discussions are now available in the literature on SW issues, routine Meteorological operational applications of SW forecast data and information for Space Environment are still yet to receive adequate attention. The paper attempts to fill this gap in the literature of SW. The paper examines the sensitivity and variability in 3-D continuum of Plasmas in response to solar radiation inputs into the magnetosphere under disturbed Sun condition. Specifically, the presence of plasma clouds in the form of Coronal Mass Ejections (CMEs) is stressed as a major source of danger to Space crews, spacecraft instrumentation and architecture charging problems as well as impacts on numerous radiation - sensitive human economic systems on Earth. Finally, the paper considers the application of model results in the form of effective monitoring of each of the two major phases of manned Spaceflights - take-off and re-entry phases where all-time assessment of spacecraft transient ambient micro-incabin and outside Space Environment is vital for all manned Spaceflights as recently evidenced by the loss of vital information during take-off of the February 1, 2003 US Columbia

  5. Doses and risks from uranium are not increased significantly by interactions with natural background photon radiation.

    Science.gov (United States)

    Tanner, R J; Eakins, J S; Jansen, J T M; Harrison, J D

    2012-08-01

    The impact of depleted uranium (DU) on human health has been the subject of much conjecture. Both the chemical and radiological aspects of its behaviour in the human body have previously been investigated in detail, with the radiological impact being assumed to be linked to the alpha decay of uranium. More recently, it has been proposed that the accumulation in tissue of high-Z materials, such as DU, may give rise to enhanced local energy deposition in the presence of natural background photon radiation due to the high photoelectric interaction cross sections of high-Z atoms. It is speculated that, in addition to producing short-range photoelectrons, these events will be followed by intense Auger and Coster-Kronig electron emission, thereby causing levels of cell damage that are unaccounted for in conventional models of radiological risk. In this study, the physical and biological bases of these claims are investigated. The potential magnitudes of any effect are evaluated and discussed, and compared with the risks from other radiological or chemical hazards. Monte Carlo calculations are performed to estimate likely energy depositions due to the presence of uranium in human tissues in photon fields: whole body doses, organ doses in anthropomorphic phantoms and nano-/micro-dosimetric scenarios are each considered. The proposal is shown generally to be based on sound physics, but overall the impact on human health is expected to be negligible.

  6. High-impedence NbSi TES sensors for studying the cosmic microwave background radiation

    CERN Document Server

    Nones, Claudia; Benoit, Alain; Bergé, Laurent; Bideau, Aurelien; Camus, Philippe; Dumoulin, Louis; Monfardini, Alessandro; Rigaut, Olivier

    2012-01-01

    Precise measurements of the cosmic microwave background (CMB) are crucial in cosmology, because any proposed model of the universe must account for the features of this radiation. Of all CMB measurements that the scientific community has not yet been able to perform, the CMB B-mode polarization is probably the most challenging from the instrumental point of view. The signature of primordial gravitational waves, which give rise to a B-type polarization, is one of the goals in cosmology today and amongst the first objectives in the field. For this purpose, high-performance low-temperature bolometric cameras, made of thousands of pixels, are currently being developed by many groups, which will improve the sensitivity to B-mode CMB polarization by one or two orders of magnitude compared to the Planck satellite HFI detectors. We present here a new bolometer structure that is able to increase the pixel sensitivities and to simplify the fabrication procedure. This innovative device replaces delicate membrane-based s...

  7. Background Radiation Survey of the Radiological/Nuclear Countermeasures Test and Evaluation Center

    Energy Technology Data Exchange (ETDEWEB)

    Colin Okada

    2010-09-16

    In preparation for operations at the Radiological/Nuclear Countermeasures Test and Evaluation Complex (Rad/NucCTEC), the Department of Homeland Security Domestic Nuclear Detection Office (DHS/DNDO) requested that personnel from the Remote Sensing Laboratory (RSL) conduct a survey of the present radiological conditions at the facility. The measurements consist of the exposure rate from a high-pressure ion chamber (HPIC), high-resolution spectra from a high-purity germanium (HPGe) system in an in situ configuration, and low-resolution spectra from a sodium iodide (NaI) detector in a radiation detection backpack. Measurements with these systems were collected at discrete locations within the facility. Measurements were also collected by carrying the VECTOR backpack throughout the complex to generate a map of the entire area. The area was also to be surveyed with the Kiwi (an array of eight-2-inch x 4-inch x 16-inch NaI detectors) from the Aerial Measuring Systems; however, conflicts with test preparation activities at the site prevented this from being accomplished.

  8. A rat model of radiation injury in the mandibular area

    International Nuclear Information System (INIS)

    Radiation technology focuses on delivering the radiation as precisely as possible to the tumor, nonetheless both acute and long-term damage to surrounding normal tissue may develop. Injuries to the surrounding normal tissue after radiotherapy of head and neck cancer are difficult to manage. An animal model is needed to elucidate good treatment modalities. The aim of this study was to establish a rat model where a certain radiation dose gives reproducible tissue reactions in the mandibular area corresponding to injuries obtained in humans. The left mandible of male Sprague Dawley rats was irradiated by external radiotherapy (single fraction 15 Gy, total dose 75 Gy) every second week five times. Endpoint was six weeks after last radiation treatment, and the test group was compared to non-irradiated controls. Morphological alterations of the soft tissues, bone and tooth formation, as well as alterations of salivation, vascularity and collagen content were assessed. An unpaired, non-parametric Mann–Whitney test was used to compare the statistical differences between the groups. Analysis of the soft tissues and mandible within the radiation field revealed severe unilateral alopecia and dermatitis of the skin, extensive inflammation of the submandibular gland with loss of serous secretory cells, hyperkeratinization and dense connective fiber bundles of the gingival tissue, and disturbed tooth development with necrosis of the pulp. Production of saliva and the vascularity of the soft tissues were significantly reduced. Furthermore, the collagen fibril diameter was larger and the collagen network denser compared to non-irradiated control rats. We have established an animal model of radiation injury demonstrating physiological and histological changes corresponding to human radiation injuries, which can be used for future therapeutic evaluations

  9. Study of radiation background at the north crossing point of the BEPC Ⅱ in collision mode%Study of radiation background at the north crossing point of the BEPC Ⅱ in collision mode

    Institute of Scientific and Technical Information of China (English)

    莫晓虎; 秦庆; 屈化民; 王贻芳; 徐金强; 张天保; 张建勇; 张清江; Achasov Mikhail; 蔡啸; 傅成栋; Harris Fred; 刘倩; Muchnoi Nikolay

    2011-01-01

    Understanding the radiation background at the north crossing point (NCP) in the tunnel of BEPCII is crucial for the performance safety of the High Purity Germanium (HPGe) detector, and in turn of great significance for long-term stable running of the ener

  10. Background Mutational Features of the Radiation-Resistant Bacterium Deinococcus radiodurans.

    Science.gov (United States)

    Long, Hongan; Kucukyildirim, Sibel; Sung, Way; Williams, Emily; Lee, Heewook; Ackerman, Matthew; Doak, Thomas G; Tang, Haixu; Lynch, Michael

    2015-09-01

    Deinococcus bacteria are extremely resistant to radiation, oxidation, and desiccation. Resilience to these factors has been suggested to be due to enhanced damage prevention and repair mechanisms, as well as highly efficient antioxidant protection systems. Here, using mutation-accumulation experiments, we find that the GC-rich Deinococcus radiodurans has an overall background genomic mutation rate similar to that of E. coli, but differs in mutation spectrum, with the A/T to G/C mutation rate (based on a total count of 88 A:T → G:C transitions and 82 A:T → C:G transversions) per site per generation higher than that in the other direction (based on a total count of 157 G:C → A:T transitions and 33 G:C → T:A transversions). We propose that this unique spectrum is shaped mainly by the abundant uracil DNA glycosylases reducing G:C → A:T transitions, adenine methylation elevating A:T → C:G transversions, and absence of cytosine methylation decreasing G:C → A:T transitions. As opposed to the greater than 100× elevation of the mutation rate in MMR(-) (DNA Mismatch Repair deficient) strains of most other organisms, MMR(-) D. radiodurans only exhibits a 4-fold elevation, raising the possibility that other DNA repair mechanisms compensate for a relatively low-efficiency DNA MMR pathway. As D. radiodurans has plentiful insertion sequence (IS) elements in the genome and the activities of IS elements are rarely directly explored, we also estimated the insertion (transposition) rate of the IS elements to be 2.50 × 10(-3) per genome per generation in the wild-type strain; knocking out MMR did not elevate the IS element insertion rate in this organism.

  11. Assessing Natural Background Levels of aquifers in the Metropolitan Area of Milan (Lombardy)

    Science.gov (United States)

    De Caro, Mattia; Crosta, Giovanni; Frattini, Paolo

    2016-04-01

    The European Water Framework Directive (WFD 2000/60/CE) requires Member States to evaluate the status of groundwater bodies in order to reach a good water quality for human consumption. One of the preliminary steps for defining the status of groundwater bodies consists in the definition and evaluation of the so-called Natural Background Levels (NBL). The NBL or Baseline level can be defined as "the range of concentration of a given element, isotope or chemical compound in solution, derived entirely from natural, geological, biological or atmospheric sources, under conditions not perturbed by anthropogenic activity" (Edmund and Shand, 2009). The qualitative analysis for a large area (ca 4500 Km2) of the Po Plain around the Milan Metropolitan area (Lombardy, Italy) is presented in this study. Despite the aquifers in the Milan metropolitan area are an incredible groundwater resource for a very large population (3.195.629 inhabitants in the metropolitan area, data at November 2014) and a highly industrialized area, a groundwater baseline characterization is still missing. In order to attain the hydro-geochemical characterization a complete geodatabase was built (120.655 chemical samples from 1980 to 2014). This database has been explored by classical and multivariate statistical analyses to provide relationships among the more influential lithological, hydrogeological and hydro-chemical variables. Finally, the NBLs of different chemical species which may be anthropogenic sensitive (Na, Cl, K, NO3, SO4, NH4, As, Fe, Cr, Fe, Mn, Zn) and for multiple aquifer bodies (phreatic, semi-confined and confined aquifer) are evaluated. Two different approaches are applied: the Pre-Selection method (BRIDGE, 2006) and the Component-Separation method. The first one (PS) consists in the exclusion of samples from the available dataset that could indicate human activities then deriving the NBL as the 90th percentile of the remaining data. The second one (CS) consists in the fitting of

  12. Distribution of terrestrial gamma radiation dose rate in the eastern coastal area of Odisha, India.

    Science.gov (United States)

    Gusain, G S; Rautela, B S; Sahoo, S K; Ishikawa, T; Prasad, G; Omori, Y; Sorimachi, A; Tokonami, S; Ramola, R C

    2012-11-01

    Terrestrial gamma radiation is one of the important radiation exposures on the earth's surface that results from the three primordial radionuclides (226)Ra, (232)Th and (40)K. The elemental concentration of these elements in the earth's crust could result in the anomalous variation of the terrestrial gamma radiation in the environment. The geology of the local area plays an important role in distribution of these radioactive elements. Environmental terrestrial gamma radiation dose rates were measured around the eastern coastal area of Odisha with the objective of establishing baseline data on the background radiation level. The values of the terrestrial gamma radiation dose rate vary significantly at different locations in the study area. The values of the terrestrial gamma dose rate ranged from 77 to 1651 nGy h(-1), with an average of 230 nGy h(-1). During the measurement of the terrestrial gamma dose rate, sand and soil samples were also collected for the assessment of natural radionuclides. The activities of (226)Ra, (232)Th and (40)K from these samples were measured using a gamma-ray spectrometry with a NaI(Tl) detector. Activity concentrations of (226)Ra, (232)Th and (40)K ranged from 15.6 to 69 Bq kg(-1) with an average of 46.7 Bq kg(-1), from 28.9 to 973 Bq kg(-1) with an average of 250 Bq kg(-1) and from 139 to 952 Bq kg(-1) with an average of 429, respectively. The detailed significance of these studies has been discussed from the radiation protection point of view. PMID:22874894

  13. Gamma radiation induced background determination for (n,γ) measurements with 4π detectors.

    Energy Technology Data Exchange (ETDEWEB)

    Reifarth, R.; Browne, J. C.; Esch, E. I.; Haight, R. C.; O& #x27; Donnell, J. M.; Kronenberg, A.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.

    2003-07-29

    The main focus of this report is to investigate possibilities to disentangle the target originating γ- background from background caused by scattered neutrons at the sample assuming a DANCE like detector to measure detect the capture events.

  14. Offsite environmental monitoring report; radiation monitoring around United States nuclear test areas, Calendar Year 1996

    International Nuclear Information System (INIS)

    This report describes the Offsite Radiation Safety Program. This laboratory operated an environmental radiation monitoring program in the region surrounding the Nevada Test Site (NTS) and at former test sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. The surveillance program is designed to measure levels and trends of radioactivity, if present, in the environment surrounding testing areas to ascertain whether current radiation levels and associated doses to the general public are in compliance with existing radiation protection standards. The surveillance program additionally has the responsibility to take action to protect the health and well being of the public in the event of any accidental release of radioactive contaminants. Offsite levels of radiation and radioactivity are assessed by sampling milk, water, and air; by deploying thermoluminescent dosimeters (TLDs); and using pressurized ionization chambers (PICs). No nuclear weapons testing was conducted in 1996 due to the continuing nuclear test moratorium. During this period, R and IE personnel maintained readiness capability to provide direct monitoring support if testing were to be resumed and ascertained compliance with applicable EPA, DOE, state, and federal regulations and guidelines. Comparison of the measurements and sample analysis results with background levels and with appropriate standards and regulations indicated that there was no airborne radioactivity from diffusion or resuspension detected by the various EPA monitoring networks surrounding the NTS. There was no indication of potential migration of radioactivity to the offsite area through groundwater and no radiation exposure above natural background was received by the offsite population. All evaluated data were consistent with previous data history

  15. Offsite environmental monitoring report: Radiation monitoring around United States nuclear test areas, calendar year 1991

    Energy Technology Data Exchange (ETDEWEB)

    Chaloud, D.J.; Dicey, B.B.; Mullen, A.A.; Neale, A.C.; Sparks, A.R.; Fontana, C.A.; Carroll, L.D.; Phillips, W.G.; Smith, D.D.; Thome, D.J.

    1992-01-01

    This report describes the Offsite Radiation Safety Program conducted during 1991 by the Environmental Protection Agency`s (EPA`s) Environmental Monitoring Systems Laboratory-Las Vegas. This laboratory operates an environmental radiation monitoring program in the region surrounding the Nevada Test Site (NTS) and at former test sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. The surveillance program is designed to measure levels and trends of radioactivity, if present, in the environment surrounding testing areas to ascertain whether current radiation levels and associated doses to the general public are in compliance with existing radiation protection standards. The surveillance program additionally has the responsibility to take action to protect the health and well being of the public in the event of any accidental release of radioactive contaminants. Offsite levels of radiation and radioactivity are assessed by sampling milk, water, and air; by deploying thermoluminescent dosimeters (TLDs) and using pressurized ion chambers (PICs); and by biological monitoring of animals, food crops, and humans. Personnel with mobile monitoring equipment are placed in areas downwind from the test site prior to each nuclear weapons test to implement protective actions, provide immediate radiation monitoring, and obtain environmental samples rapidly after any occurrence of radioactivity release. Comparison of the measurements and sample analysis results with background levels and with appropriate standards and regulations indicated that there was no radioactivity detected offsite by the various EPA monitoring networks and no exposure above natural background to the population living in the vicinity of the NTS that could be attributed to current NTS activities. Annual and long-term trends were evaluated in the Noble Gas, Tritium, Milk Surveillance, Biomonitoring, TLD, PIC networks, and the Long-Term Hydrological Monitoring Program.

  16. Offsite environmental monitoring report: Radiation monitoring around United States nuclear test areas, calendar year 1991

    International Nuclear Information System (INIS)

    This report describes the Offsite Radiation Safety Program conducted during 1991 by the Environmental Protection Agency's (EPA's) Environmental Monitoring Systems Laboratory-Las Vegas. This laboratory operates an environmental radiation monitoring program in the region surrounding the Nevada Test Site (NTS) and at former test sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. The surveillance program is designed to measure levels and trends of radioactivity, if present, in the environment surrounding testing areas to ascertain whether current radiation levels and associated doses to the general public are in compliance with existing radiation protection standards. The surveillance program additionally has the responsibility to take action to protect the health and well being of the public in the event of any accidental release of radioactive contaminants. Offsite levels of radiation and radioactivity are assessed by sampling milk, water, and air; by deploying thermoluminescent dosimeters (TLDs) and using pressurized ion chambers (PICs); and by biological monitoring of animals, food crops, and humans. Personnel with mobile monitoring equipment are placed in areas downwind from the test site prior to each nuclear weapons test to implement protective actions, provide immediate radiation monitoring, and obtain environmental samples rapidly after any occurrence of radioactivity release. Comparison of the measurements and sample analysis results with background levels and with appropriate standards and regulations indicated that there was no radioactivity detected offsite by the various EPA monitoring networks and no exposure above natural background to the population living in the vicinity of the NTS that could be attributed to current NTS activities. Annual and long-term trends were evaluated in the Noble Gas, Tritium, Milk Surveillance, Biomonitoring, TLD, PIC networks, and the Long-Term Hydrological Monitoring Program

  17. Automated System of Area Radiation Measurement (ASARM); Sistema Automatizado de Medicion de Radiacion de Area (SAMRA)

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez G, J., E-mail: jaime.hernandez@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2013-10-15

    The realized activities in nuclear facilities involve the determination of the presence of ionizing radiation fields in the workspaces. The instruments designed to detect and to measure these radiation fields provide useful information (specific type of radiation, intensity, etc.) to take the appropriate radiological protection measures, with the purpose of reducing to the minimum the workers exposition and the people in general. The radiological protection program of Reactor TRIGA Mark III contains the instructions and procedures to implement a periodic radiological monitoring, surveillance, rising of contamination levels, type and number of the instruments required for the radiological monitoring of areas and personal. The ana logical monitoring system model Rms II used to detect and measuring exposition speed and neutron radiation fields in several areas of the installation, provides the information in a logarithmic scale measurer of 4 or 5 decades located in a shelf where the previously mentioned measurement channels are centralized. Also inside the reactor monitoring system are two monitors of radioactive material concentration in the air: The particles continuous monitor and the gaseous effluents monitor which present the referred information of the diverse detectors through ana logical readers. These monitors when operating with an ana logical indication does not present the possibility to generate historical files electronically of each monitor previously mentioned neither to generate visual and audible indications of the alarms. This work presents the Automated System of Area Radiation Measurement which potentiated the functionality of the area monitors for gamma and neutron radiation, as well as of the particles continuous monitor and the gaseous effluents of reactor TRIGA Mark III, when being developed a computer system that captures in real time the information of all the monitors, generating this way an electronic binnacle, a visual and audible alarm

  18. Size distributions, sources and source areas of water-soluble organic carbon in urban background air

    Directory of Open Access Journals (Sweden)

    H. Timonen

    2008-09-01

    Full Text Available This paper represents the results of one year long measurement period of the size distributions of water-soluble organic carbon (WSOC, inorganic ions and gravimetric mass of particulate matter. Measurements were done at an urban background station (SMEAR III by using a micro-orifice uniform deposit impactor (MOUDI. The site is located in northern European boreal region in Helsinki, Finland. The WSOC size distribution measurements were completed with the chemical analysis of inorganic ions, organic carbon (OC and monosaccharide anhydrides from the filter samples (particle aerodynamic diameter smaller than 1 μm, PM1. Gravimetric mass concentration varied during the MOUDI samplings between 3.4 and 55.0 μg m−3 and the WSOC concentrations were between 0.3 and 7.4 μg m−3. On average, water-soluble particulate organic matter (WSPOM, WSOC multiplied by 1.6 to convert the analyzed carbon mass to organic matter mass comprised 25±7.7% and 7.5±3.4% of aerosol PM1 mass and the PM1–10 mass, respectively. Inorganic ions contributed 33±12% and 28±19% of the analyzed PM1 and PM1–10 aerosol mass.

    Five different aerosol categories corresponding to different sources or source areas were identified (long-range transport aerosols, biomass burning aerosols from wild land fires and from small-scale wood combustion, aerosols originating from marine areas and from the clean arctic areas. Categories were identified mainly using levoglucosan concentration level for wood combustion and air mass backward trajectories for other groups. Clear differences in WSOC concentrations and size distributions originating from different sources or source areas were observed, although there are also many other factors which might affect the results. E.g. the local conditions and sources of volatile organic compounds (VOCs and aerosols as well as various transformation processes are likely

  19. Size distributions, sources and source areas of water-soluble organic carbon in urban background air

    Directory of Open Access Journals (Sweden)

    H. Timonen

    2008-04-01

    Full Text Available This paper represents the results of one year long measurement period of the size distributions of water-soluble organic carbon (WSOC, inorganic ions and gravimetric mass of particulate matter. Measurements were done at an urban background station (SMEAR III by using a micro-orifice uniform deposit impactor (MOUDI. The site is located in northern European boreal region in Helsinki, Finland. The WSOC size distribution measurements were completed with the chemical analysis of inorganic ions, organic carbon (OC and monosaccharide anhydrides from the filter samples. During the measurements gravimetric mass in the MOUDI collections varied between 3.4 and 55.0 μg m−3 and the WSOC concentration was between 0.3 and 7.4 μg m−3. On average, water-soluble particulate organic matter (WSPOM, WSOC multiplied by 1.6 comprised 25±7.7% and 7.5±3.4% of aerosol PM1 mass and the PM1−10 mass, respectively. Inorganic ions contributed 33±12% and 28±19% of the analyzed PM1 and PM1−10 aerosol mass.

    Five different aerosol categories corresponding to different sources or source areas were identified (long-range transport aerosols, biomass burning aerosols from wild land fires and from small-scale wood combustion, aerosols originating from marine areas and from the clean arctic areas. Clear differences in WSOC concentrations and size distributions originating from different sources or source areas were observed, although there are also many other factors which might affect the results. E.g. the local conditions and sources of volatile organic compounds (VOCs and aerosols as well as various transformation processes are likely to have an impact on the measured aerosol composition. Using the source categories, it was identified that especially the oxidation products of biogenic VOCs in summer had a clear effect on WSOC concentrations.

  20. Characterization of gaseous detectors at the CERN Gamma Irradiation Facility: GEM performance in presence of high background radiation

    CERN Document Server

    AUTHOR|(CDS)2097588

    Muon detection is an efficient tool to recognize interesting physics events over the high background rate expected at the Large Hadron Collider (LHC) at CERN. The muon systems of the LHC experiments are based on gaseous ionization detectors. In view of the High-Luminosity LHC (HL-LHC) upgrade program, the increasing of background radiation could affect the gaseous detector performance, especially decreasing the efficiency and shortening the lifetime through ageing processes. The effects of charge multiplication, materials and gas composition on the ageing of gaseous detectors have been studied for decades, but the future upgrade of LHC requires additional studies on this topic. At the CERN Gamma Irradiation Facility (GIF++), a radioactive source of cesium-137 with an activity of 14 TBq is used to reproduce reasonably well the expected background radiation at HL-LHC. A muon beam has been made available to study detector performance. The characterization of the beam trigger will be discussed in the present w...

  1. High-impedance NbSi TES sensors for studying the cosmic microwave background radiation

    Science.gov (United States)

    Nones, C.; Marnieros, S.; Benoit, A.; Bergé, L.; Bideaud, A.; Camus, P.; Dumoulin, L.; Monfardini, A.; Rigaut, O.

    2012-12-01

    Precise measurements of the cosmic microwave background (CMB) are crucial in cosmology because any proposed model of the universe must account for the features of this radiation. The CMB has a thermal blackbody spectrum at a temperature of 2.725 K, i.e. the spectrum peaks in the microwave range frequency of 160.2 GHz, corresponding to a 1.9-mm wavelength. Of all CMB measurements that the scientific community has not yet been able to perform, the CMB B-mode polarization is probably the most challenging from the instrumental point of view. The signature of primordial gravitational waves, which give rise to a B-type polarization, is one of the goals in cosmology today and amongst the first objectives in the field. For this purpose, high-performance low-temperature bolometric cameras, made of thousands of pixels, are currently being developed by many groups, which will improve the sensitivity to B-mode CMB polarization by one or two orders of magnitude compared to the Planck satellite HFI detectors. We present here a new bolometer structure that is able to increase the pixel sensitivities and to simplify the fabrication procedure. This innovative device replaces delicate membrane-based structures and eliminates the mediation of phonons: the incoming energy is directly captured and measured in the electron bath of an appropriate sensor and the thermal decoupling is achieved via the intrinsic electron-phonon decoupling of the sensor at very low temperature. Reported results come from a 204-pixel array of NbxSi1-x transition edge sensors with a meander structure fabricated on a 2-inch silicon wafer using electron-beam co-evaporation and a cleanroom lithography process. To validate the application of this device to CMB measurements, we have performed an optical calibration of our sample in the focal plane of a dilution cryostat test bench. We have demonstrated a light absorption close to 20% and an optical noise equivalent power of about 7×10-16 W/√Hz, which is highly

  2. Radiation doses to rodents inhabiting a radioactive waste receiving area

    International Nuclear Information System (INIS)

    A study was conducted of the gamma ray doses to four species of native rodents inhabiting a low level radioactive liquid waste disposal area. Absorbed doses of radiation were measured with lithium fluoride thermoluminescent dosimeters that were implanted subcutaneously. The absorbed radiation doses and 137Cs body burdens were significantly higher for western harvest mice (Reithrodontomys megalotis) than for deer mice (Peromyscus maniculatus), pinon mice (P. truei) and the least chipmunk (Eutamias minimus), reflecting differences in mobility and habitat preferences of the respective species. The average dose received by harvest mice was 26 mrad/day, which was 26% of the highest gamma dose detected at the ground surface in the study plot, although the maximum dose received by individual mice was as high as 45% of the maximum dose rates in the plot. (author)

  3. Radiation impact assessment on wildlife from an uranium mine area

    International Nuclear Information System (INIS)

    Highlights: ► Radiation impact of a uranium mine environment was assessed. ► The ERICA Tool was applied to the sites exposed to radionuclide discharge. ► No environmental radiological risk to biota was observed. ► The emission of radionuclides does not pose a threat to the local wildlife. - Abstract: Uranium mining and milling activities are one of the major causes of radioactive contamination of the environment. Radionuclides, especially uranium decay-chain products, are released from plant wastes into the soil and water and consequently into vegetation where they may accumulate. Transfer of radionuclides thus represents a radiological risk to humans and non-human organisms due to accumulation of radionuclides in target tissues and the consequent ionising radiation. The uranium mine at Žirovski vrh in Slovenia, which operated from 1985 to 1990, processed about 600,000 t of U-ore. Operational wastes were deposited at the Boršt and Jazbec sites. According to several studies, an environmental radiological risk to biota could be observed at sites exposed to radioactive contamination. A modelling approach can be used to estimate the risk in such areas. The ERICA tool is one of the more widely used models, developed to assess the environmental risk from ionising radiation to wildlife. In the present study, the ERICA Tool was applied for the assessment of the radiation impact on wildlife in the Žirovski vrh influential area. ERICA reference organisms, native plants and aquatic organisms were included in the assessment to screen the risk to different organisms. Total dose rate to organisms were up to 3.49, 33.0 and 2.58 μGy h−1 for Juncus effusus, lichens and Austropotamobius torrentium, respectively. Dose rates to other organisms are also presented and discussed.

  4. Analysis on the Variation Characteristics of Temperature and Precipitation in Benxi Area under the Background of Climate Warming

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The research aimed to study the variation characteristics of temperature and precipitation in Benxi area under the background of climate warming.[Method] Based on the monthly mean temperature and precipitation data of four routine meteorological stations in Benxi area from 1953 to 2010,by using linear tendency rate,linear regression equation,wavelet analysis,Mann-Kendall detection and so on,the variation characteristics of temperature and precipitation under the background of climate warming in ...

  5. Urbanization effects on natural radiation in anomalous areas

    International Nuclear Information System (INIS)

    The urbanization effects and their possible causes on the environmental gamma radiation levels, in an anomalous area, were studied. The field work was accomplished in Guarapari, located in the seacoast of the Brazilian state of Espirito Santo, which is rich in monazite sands, with thorium and uranium contents. The results show clearly that there was a reduction in the levels of external exposition in the streets and squares of Guarapari. It was ascertained that the reduction was due to the materials used in the urbanization. (L.C.J.A.)

  6. Radiation monitoring around United States nuclear test areas, calendar year 1989

    International Nuclear Information System (INIS)

    This report describes the Offsite Radiation Safety Program conducted during 1989 by the Environmental Protection Agency's (EPA's) Environmental Monitoring Systems Laboratory-Las Vegas (EMSL-LV). This laboratory operates an environmental radiation monitoring program in the region surrounding the Nevada Test Site (NTS) and at former test sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. The surveillance program is designed to measure levels, and trends of radioactivity, if present, in the environment surrounding testing areas to ascertain whether the testing is in compliance with existing radiation protection standards, and to take action to protect the health and well being of the public in the event of any accidental release of radioactive contaminants. Offsite levels of radiation and radioactivity are assessed by sampling milk, water, and air; by deploying thermoluminescent dosimeters (TLDs) and using pressurized ion chambers (PICs); and by biological monitoring of both animals and humans. To implement protective actions, provide immediate radiation monitoring, and obtain environmental samples rapidly after any release of radioactivity, personnel with mobile monitoring equipment are placed in areas downwind from the test site prior to each test. Comparison of the measurements and sample analysis results with background levels and with appropriate standards and regulations indicated that there was no radioactivity detected offsite by the various EPA monitoring networks and no exposure above natural background to the population living in the vicinity of the NTS that could be attributed to NTS activities. Trends were evaluated in the Noble Gas and Tritium, Milk Surveillance, TLD, and PIC networks, and the Long-Term Hydrological Monitoring Program. 35 refs., 68 figs., 32 tabs

  7. Attitudes and Perceptions of Patients, Caregivers, and Health Care Providers toward Background Music in Patient Care Areas: An Exploratory Study

    Science.gov (United States)

    Perez-Cruz, Pedro; Nguyen, Linh; Rhondali, Wadih; Hui, David; Palmer, J. Lynn; Sevy, Ingrid; Richardson, Michael

    2012-01-01

    Abstract Background Background music can be used to distract from ordinary sounds and improve wellbeing in patient care areas. Little is known about individuals' attitudes and beliefs about music versus ordinary sound in this setting. Objectives To assess the preferences of patients, caregivers and healthcare providers regarding background music or ordinary sound in outpatient and inpatient care areas, and to explore their attitudes and perceptions towards music in general. Methods All participants were exposed to background music in outpatient or inpatient clinical settings. 99 consecutive patients, 101 caregivers and 65 out of 70 eligible healthcare providers (93%) completed a survey about music attitudes and preferences. The primary outcome was a preference for background music over ordinary sound in patient care areas. Results Preference for background music was high and similar across groups (70 patients (71%), 71 caregivers (71%) and 46 providers (71%), p=0.58). The three groups had very low disapproval for background music in patient care areas (10%, 9% and 12%, respectively; p=0.91). Black ethnicity independently predicted lower preference for background music (OR: 0.47, 95%CI: 0.23, 0.98). Patients, caregivers and providers reported recent use of music for themselves for the purpose of enjoyment (69%, 80% and 86% respectively p=0.02). Age, gender, religion and education level significantly predicted preferences for specific music styles. Conclusion Background music in patient care areas was preferred to ordinary sound by patients, caregivers and providers. Demographics of the population are strong determinants of music style preferences. PMID:22957677

  8. Historical background and overview of epidemiological studies on the effects of low-level radiation

    International Nuclear Information System (INIS)

    Recognition of the carcinogenic effects of ionizing radiation dates from the early part of this century, when an increased frequency of skin cancer and leukemia was first reported in radiologists. In the interim, systematic epidemiological studies have disclosed additional carcinogenic effects in radiation workers, A-bomb survivors, patients exposed to diagnostic or therapeutic radiation, and other groups. The studies have provided sufficient data on dose-incidence relationships, the distribution of cancer in relation to age at irradiation and time after exposure, and organ-variations in susceptibility to enable attempts at quantitative assessment of the risks of low-level irradiation. Such assessments, although tentative and controversial, have exerted an important influence on developments in radiological protection

  9. Pulse-shape analysis for gamma background rejection in thermal neutron radiation using CVD diamond detectors

    Energy Technology Data Exchange (ETDEWEB)

    Kavrigin, P., E-mail: pavel.kavrigin@cividec.at [Vienna University of Technology (Austria); Finocchiaro, P., E-mail: finocchiaro@lns.infn.it [INFN Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); Griesmayer, E., E-mail: erich.griesmayer@cividec.at [Vienna University of Technology (Austria); Jericha, E., E-mail: jericha@ati.ac.at [Vienna University of Technology (Austria); Pappalardo, A., E-mail: apappalardo@lns.infn.it [INFN Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); Weiss, C., E-mail: Christina.Weiss@cern.ch [Vienna University of Technology (Austria); European Organisation for Nuclear Research (CERN), Geneva (Switzerland)

    2015-09-21

    A novel technique for the rejection of gamma background from charged-particle spectra was demonstrated using a CVD diamond detector with a {sup 6}Li neutron converter installed at a thermal neutron beamline of the TRIGA research reactor at the Atominstitut (Vienna University of Technology). Spectra of the alpha particles and tritons of {sup 6}Li(n,T){sup 4}He thermal neutron capture reaction were separated from the gamma background by a new algorithm based on pulse-shape analysis. The thermal neutron capture in {sup 6}Li is already used for neutron flux monitoring, but the ability to remove gamma background allows using a CVD diamond detector for thermal neutron counting. The pulse-shape analysis can equally be applied to all cases where the charged products of an interaction are absorbed in the diamond and to other background particles that fully traverse the detector.

  10. Pulse-shape analysis for gamma background rejection in thermal neutron radiation using CVD diamond detectors

    Science.gov (United States)

    Kavrigin, P.; Finocchiaro, P.; Griesmayer, E.; Jericha, E.; Pappalardo, A.; Weiss, C.

    2015-09-01

    A novel technique for the rejection of gamma background from charged-particle spectra was demonstrated using a CVD diamond detector with a 6Li neutron converter installed at a thermal neutron beamline of the TRIGA research reactor at the Atominstitut (Vienna University of Technology). Spectra of the alpha particles and tritons of 6Li(n,T)4He thermal neutron capture reaction were separated from the gamma background by a new algorithm based on pulse-shape analysis. The thermal neutron capture in 6Li is already used for neutron flux monitoring, but the ability to remove gamma background allows using a CVD diamond detector for thermal neutron counting. The pulse-shape analysis can equally be applied to all cases where the charged products of an interaction are absorbed in the diamond and to other background particles that fully traverse the detector.

  11. The X-ray log N-log S relation. [background radiation in extragalactic media

    Science.gov (United States)

    Boldt, Elihu

    1989-01-01

    Results from various surveys are reviewed as regards X-ray source counts at high galactic latitudes and the luminosity functions determined for extragalactic sources. Constraints on the associated log N-log S relation provided by the extragalactic X-ray background are emphasized in terms of its spatial fluctuations and spectrum as well as absolute flux level. The large number of sources required for this background suggests that there is not a sharp boundary in the redshift distribution of visible matter.

  12. The Cosmic Microwave Background Radiation Power Spectrum as a Random Bit Generator for Symmetric and Asymmetric-Key Cryptography

    CERN Document Server

    Lee, Jeffrey S

    2016-01-01

    In this note, the Cosmic Microwave Background (CMB) Radiation is shown to be capable of functioning as a Random Bit Generator, and constitutes an effectively infinite supply of truly random one-time pad values of arbitrary length. It is further argued that the CMB power spectrum potentially conforms to the FIPS 140-2 standard. Additionally, its applicability to the generation of a (n x n) random key matrix for a Vernam cipher is established.

  13. Hybrid radiation background monitoring in operational control and forecasting of environmental contamination by nuclear power station discharges

    International Nuclear Information System (INIS)

    Rapid developments in nuclear power have stimulated research on monitoring and forecasting environmental radiation pollution (ERP), and in particular the amounts, compositions, and distributions of radionuclides in the environment. A conceptual model is presented for hybrid environmental radiation pollution monitoring. When there is an emergency, the model operates in a fashion most closely corresponding to the actual meteorological conditions, and the ERP data given by the model enable one to distinguish changes due to the man-made component from random fluctuations in the natural background. The measurement system in general includes mobile and stationary data-acquisition facilities linked by wire or radio to the central point. The system also accumulates and stores data on the radiation environment, which are edited on the basis of radioactive, chemical, and other transformations. The purpose of hybrid monitoring is ultimately to analyze trends in order to detect elevated discharges and thus to output data to the regional monitoring system

  14. Hybrid methodology for hourly global radiation forecasting in Mediterranean area

    CERN Document Server

    Voyant, Cyril; Paoli, Christophe; Nivet, Marie Laure

    2012-01-01

    The renewable energies prediction and particularly global radiation forecasting is a challenge studied by a growing number of research teams. This paper proposes an original technique to model the insolation time series based on combining Artificial Neural Network (ANN) and Auto-Regressive and Moving Average (ARMA) model. While ANN by its non-linear nature is effective to predict cloudy days, ARMA techniques are more dedicated to sunny days without cloud occurrences. Thus, three hybrids models are suggested: the first proposes simply to use ARMA for 6 months in spring and summer and to use an optimized ANN for the other part of the year; the second model is equivalent to the first but with a seasonal learning; the last model depends on the error occurred the previous hour. These models were used to forecast the hourly global radiation for five places in Mediterranean area. The forecasting performance was compared among several models: the 3 above mentioned models, the best ANN and ARMA for each location. In t...

  15. Ralph A. Alpher, George Antonovich Gamow, and the Prediction of the Cosmic Microwave Background Radiation

    CERN Document Server

    Alpher, Victor S

    2014-01-01

    The first prediction of the existence of "relict radiation" or radiation remaining from the "Big Bang" was made in 1948. This derived from the seminal dissertation work of Ralph A. Alpher. He was a doctoral student of George A. Gamow and developed several critical advances in cosmology in late 1946, 1947, and 1948. Alpher developed the ideas of "hot" big bang cosmology to a high degree of physical precision, and was the first to present the idea that radiation, not matter, predominated the early universal adiabatic expansion first suggested by A. Friedmann in the early 1920s. Alpher and Herman predicted the residual relic black-body temperature in 1948 and 1949 at around 5 K. However, to this day, this prediction, and other seminal ideas in big bang cosmology, have often been attributed erroneously to the better-known George A. Gamow. This article reviews some of the more egregious and even farcical errors in the scholarly literature about Ralph A. Alpher and his place in the history of big bang cosmology. Tw...

  16. The modulating impact of illumination and background radiation on 8 Hz-induced infrasound effect on physicochemical properties of physiolagical solution.

    Science.gov (United States)

    Baghdasaryan, Naira; Mikayelyan, Yerazik; Barseghyan, Sedrak; Dadasyan, Erna; Ayrapetyan, Sinerik

    2012-12-01

    At present, when the level of background ionizing radiation is increasing in a number of world locations, the problem of the study of biological effect of high background radiation becomes one of the extremely important global problems in modern life sciences. The modern research in biophysics proved that water is a most essential target, through which the biological effects of ionizing and non-ionizing radiations are realized. Therefore, there is no doubt about the strong dependency of non-ionizing radiation-induced effect on the level of background radiation. Findings have shown that illumination and background radiation have a strong modulation effect on infrasound-induced impacts on water physicochemical properties, which could also have appropriate effect on living organisms. PMID:22676714

  17. Small-scale primordial magnetic fields and anisotropies in the cosmic microwave background radiation

    Energy Technology Data Exchange (ETDEWEB)

    Jedamzik, Karsten [Laboratoire de Univers et Particules, UMR5299-CNRS, Université de Montpellier II, F-34095 Montpellier (France); Abel, Tom, E-mail: karsten.jedamzik@um2.fr, E-mail: tabel@slac.stanford.edu [Kavli Institute for Particle Astrophysics and Cosmology, SLAC/Stanford University, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)

    2013-10-01

    It is shown that small-scale magnetic fields present before recombination induce baryonic density inhomogeneities of appreciable magnitude. The presence of such inhomogeneities changes the ionization history of the Universe, which in turn decreases the angular scale of the Doppler peaks and increases Silk damping by photon diffusion. This unique signature could be used to (dis)prove the existence of primordial magnetic fields of strength as small as B ≅ 10{sup −11} Gauss by cosmic microwave background observations.

  18. Enhancement of natural background gamma-radiation dose around uranium microparticles in the human body

    OpenAIRE

    Pattison, John E; Hugtenburg, Richard P.; Green, Stuart

    2009-01-01

    Ongoing controversy surrounds the adverse health effects of the use of depleted uranium (DU) munitions. The biological effects of gamma-radiation arise from the direct or indirect interaction between secondary electrons and the DNA of living cells. The probability of the absorption of X-rays and gamma-rays with energies below about 200 keV by particles of high atomic number is proportional to the third to fourth power of the atomic number. In such a case, the more heavily ionizing low-energy ...

  19. Assessment of radiation exposure around abandoned uranium mining area of Stara planina Mt., Serbia

    Directory of Open Access Journals (Sweden)

    Tanić Milan N.

    2014-01-01

    Full Text Available The aim of this work was to estimate the health and radiation hazard due to external irradiation from terrestrial radionuclides in the Stara planina Mt. region, which is important because of past uranium mining activities on the mountain. Soil samples were collected inside the flotation processing facilities, their surroundings and more distant locations, i.e. from areas considered certainly affected, potentially affected, and unaffected by former mining and uranium ore processing activities. The radiological and health risk assessments were done by calculating the six main parameters, based on the activity concentration of 238U, 232Th, and 40K in soil samples as determined by gamma-ray spectrometry. Increased values of the risk parameters were observed only for sites where uranium ore was processed, while the location surrounding these compounds showed values that are usual for this mountain or slightly above them. Calculations of the risk parameters for the background area showed no radiation risk for the local and seasonal population. The presence of U and Th was detected in all water samples from creeks surrounding the facilities, but only in the water from the facility drainage pipe did their concentration exceed the limits given for the uranium content in drinking water. In conclusion, the results obtained in this study fall within the range of values in similar studies conducted worldwide and are below the values which can cause a significant radiation hazard. [Projekat Ministarstva nauke Republike Srbije, br. III43009 i br. III41005

  20. Human projected area factors for detailed direct and diffuse solar radiation analysis

    DEFF Research Database (Denmark)

    Kubaha, K.; Fiala, D.; Toftum, Jørn;

    2004-01-01

    Projected area factors for individual segments of the standing and sedentary human body were modelled for both direct and diffuse solar radiation using detailed 3D geometry and radiation models. The local projected area factors with respect to direct short-wave radiation are a function of the solar...

  1. Determination of Absorbed and Effective Dose from Natural Background Radiation around a Nuclear Research Facility

    Directory of Open Access Journals (Sweden)

    M. A. Musa

    2011-01-01

    Full Text Available Problem statement: This study presents result of outdoor absorbed dose rate and estimated effective dose from the naturally occurring radionuclides 232Th and 238U series 40K, around a Nuclear Research Reactor at the Centre for Energy Research and Training (CERT, Zaria, Nigeria. Approach: A high-resolution in situ ?-ray spectrometry was used to carry out the study. CERT houses a 30Kw Research Reactor and other neutron and gamma sources for Research and Training. Results: The values of absorbed dose rate in air for 232Th, 238U and 40K range from 8.2 ± 2.5-24.5 ± 3.6 nGy h?1, 1.9 ± 1.2-4.6 ± 2.5 nGy h?1 and 12.2 ± 5-38 ± 6.7n Gy h?1 respectively . The estimated total annual effective dose outdoor for the sites range from 27.3-79.9 ?Sv y?1.Conclusions: This showed that radiation exposure level for the public is lower than the recommended value of 1 mSv y?1.Hence, the extensive usage of radioactive materials within and around CERT does not appear to have any impact on the radiation burden of the environment.

  2. Probing the Cosmic X-Ray and MeV Gamma-Ray Background Radiation through the Anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Yoshiyuki [Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology; SLAC National Accelerator Lab., Menlo Park, CA (United States); Murase, Kohta [Inst. for Advanced Study, Princeton, NJ (United States). School of Natural Sciences; Madejski, Grzegorz M. [Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology; SLAC National Accelerator Lab., Menlo Park, CA (United States); Uchiyama, Yasunobu [Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology; SLAC National Accelerator Lab., Menlo Park, CA (United States); Rikkyo Univ., Tokyo (Japan). Dept. of Physics

    2013-09-24

    While the cosmic soft X-ray background is very likely to originate from individual Seyfert galaxies, the origin of the cosmic hard X-ray and MeV gamma-ray background is not fully understood. It is expected that Seyferts including Compton thick population may explain the cosmic hard X-ray background. At MeV energy range, Seyferts having non-thermal electrons in coronae above accretion disks or MeV blazars may explain the background radiation. We propose that future measurements of the angular power spectra of anisotropy of the cosmic X-ray and MeV gamma-ray backgrounds will be key to deciphering these backgrounds and the evolution of active galactic nuclei (AGNs). As AGNs trace the cosmic large-scale structure, spatial clustering of AGNs exists. We show that e-ROSITA will clearly detect the correlation signal of unresolved Seyferts at 0.5-2 keV and 2-10 keV bands and will be able to measure the bias parameter of AGNs at both bands. Once the future hard X-ray all sky satellites achieve the sensitivity better than 10-12 erg/cm2/s-1 at 10-30 keV or 30-50 keV - although this is beyond the sensitivities of current hard X-ray all sky monitors - angular power spectra will allow us to independently investigate the fraction of Compton-thick AGNs in all Seyferts. We also find that the expected angular power spectra of Seyferts and blazars in the MeV range are different by about an order of magnitude, where the Poisson term, so-called shot noise, is dominant. Current and future MeV instruments will clearly disentangle the origin of the MeV gamma-ray background through the angular power spectrum.

  3. Reduction of radioactive backgrounds in electroformed copper for ultra-sensitive radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hoppe, E.W., E-mail: eric.hoppe@pnnl.gov [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Aalseth, C.E.; Farmer, O.T.; Hossbach, T.W.; Liezers, M.; Miley, H.S.; Overman, N.R. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Reeves, J.H. [Reeves and Son LLC, 10 Albert Ave., Richland, WA 99352 (United States)

    2014-11-11

    Ultra-pure construction materials are required for the next generation of neutrino physics, dark matter and environmental science applications. These materials are also important for use in high-purity germanium spectrometers used in screening materials for radiopurity. The next-generation science applications require materials with radiopurity levels at or below 1 μBq/kg {sup 232}Th and {sup 238}U. Yet radiometric analysis lacks sensitivity below ∼10 μBq/kg for the U and Th decay chains. This limits both the selection of clean materials and the validation of purification processes. Copper is an important high-purity material for low-background experiments due to the ease with which it can be purified by electrochemical methods. Electroplating for purification into near-final shapes, known as electroforming, is one such method. Continued refinement of the copper electroforming process is underway, for the first time guided by an ICP-MS based assay method that can measure {sup 232}Th and {sup 238}U near the desired purity levels. An assay of electroformed copper at a μBq/kg level has been achieved and is described. The implications of electroformed copper at or better than this purity on next-generation low-background experiments are discussed.

  4. Reduction of Radioactive Backgrounds in Electroformed Copper for Ultra-Sensitive Radiation Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hoppe, Eric W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Aalseth, Craig E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Farmer, Orville T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hossbach, Todd W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Liezers, Martin [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Miley, Harry S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Overman, Nicole R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Reeves, James H. [Reeves and Son LLC., Richland, WA (United States)

    2014-07-07

    Abstract Ultra-pure construction materials are required for the next generation of neutrino physics, dark matter and environmental science applications. These new efforts require materials with purity levels at or below 1 uBq/kg 232Th and 238U. Yet radiometric analysis lacks sensitivity below ~10 uBq/kg for the U and Th decay chains. This limits both the selection of clean materials and the validation of purification processes. Copper is an important high-purity material for low-background experiments due to the ease with which it can be purified by electrochemical methods. Electroplating for purification into near-final shapes, known as electroforming, is one such method. Continued refinement of the copper electroforming process is underway, for the first time guided by an ICP-MS based assay method that can measure 232Th and 238U near the desired purity levels. An assay of electroformed copper at 10 uBq/kg for 232Th has been achieved and is described. The implications of electroformed copper at or better than this purity on next-generation low-background experiments are discussed.

  5. Large-scale anisotropy of the cosmic background radiation due to primordial density and gravitational-wave perturbations

    International Nuclear Information System (INIS)

    The possibility that part of the recently discovered large-scale anisotropy of the cosmic background radiation is aroused from primordial density and gravitational-wave perturbations through the Sachs-Wolfe effect, is investigated in both closed and open models in connection with the severe constraint for the small-scale anisotropy. It is concluded that, in order to explain the dipole anisotropy of the order of 10-3 by density perturbations, closed models and density fluctuation spectrums not steeper than ''white noise'' one are required, and that gravitational-wave perturbations cannot contribute to the possible quadrupole anisotropy of the order of 10-4. (author)

  6. The Temperature of the Cosmic Background Radiation: Results fromthe 1987 and 1988 Measurements at 3.8 GHz

    Energy Technology Data Exchange (ETDEWEB)

    De Amici, Giovanni; Bensadoun, M.; Bersanelli, M.; Kogut, A.; Levine, S.; Smoot, George F.; Witebsky, C.

    1989-11-10

    We have measured the temperature of the cosmic background radiation (CBR) at a frequency of 3.8 GHz (7.9 cm wavelength), during two consecutive summers, obtaining a brightness temperature, T{sub CBR}, of 2.56 {+-} 0.08 K in 1987 and 2.71 {+-} 0.07 K in 1988 (68% confidence level). The new results are in agreement with our previous measurement at 3.7 GHz obtained in 1986, and have smaller error bars. Combining measurements from all three years we obtain T{sub CBR} = 2.64 {+-} 0.07 K.

  7. A bolometric millimeter-wave system for observations of anisotropy in the cosmic microwave background radiation on medium angular scales

    Science.gov (United States)

    Fischer, M. L.; Alsop, D. C.; Cheng, E. S.; Clapp, A. C.; Cottingham, D. A.; Gundersen, J. O.; Koch, T. C.; Kreysa, E.; Meinhold, P. R.; Lange, A. E.

    1992-01-01

    We report the performance of a bolometric system designed to measure the anisotropy of the cosmic microwave background (CMB) radiation on angular scales from 0 deg 3 min to 3 deg. The system represents a collaborative effort combining a low-background 1 m diameter balloon-borne telescope with new multimode feed optics, a beam modulation mechanism with high stability, and a four-channel bolometric receiver with passbands centered near frequencies of 3 (90), 6 (180), 9 (270), and 12 (360) cm(exp -1) (GHz). The telescope was flown three times with the bolometric receiver and has demonstrated detector noise limited performance capable of reaching sensitivity levels of Delta(T)/T(sub CMB) is approximately equal to 10(exp -5) with detectors operated at T = 0.3 K.

  8. Comparison of estimated and background subsidence rates in Texas-Louisiana geopressured geothermal areas

    Energy Technology Data Exchange (ETDEWEB)

    Lee, L.M.; Clayton, M.; Everingham, J.; Harding, R.C.; Massa, A.

    1982-06-01

    A comparison of background and potential geopressured geothermal development-related subsidence rates is given. Estimated potential geopressured-related rates at six prospects are presented. The effect of subsidence on the Texas-Louisiana Gulf Coast is examined including the various associated ground movements and the possible effects of these ground movements on surficial processes. The relationships between ecosystems and subsidence, including the capability of geologic and biologic systems to adapt to subsidence, are analyzed. The actual potential for environmental impact caused by potential geopressured-related subsidence at each of four prospects is addressed. (MHR)

  9. Radiation and Background Levels in a CLIC Detector due to Beam-Beam Effects Optimisation of Detector Geometries and Technologies

    CERN Document Server

    Sailer, André; Lohse, Thomas

    2013-01-10

    The high charge density---due to small beam sizes---and the high energy of the proposed CLIC concept for a linear electron--positron collider with a centre-of-mass energy of up to 3~TeV lead to the production of a large number of particles through beam-beam interactions at the interaction point during every bunch crossing (BX). A large fraction of these particles safely leaves the detector. A still significant amount of energy will be deposited in the forward region nonetheless, which will produce secondary particles able to cause background in the detector. Furthermore, some particles will be created with large polar angles and directly cause background in the tracking detectors and calorimeters. The main sources of background in the detector, either directly or indirectly, are the incoherent $mathrm{e}^{+}mathrm{e}^{-}$ pairs and the particles from $gammagamma ightarrow$ hadron events. The background and radiation levels in the detector have to be estimated, to study if a detector is feasible, that can han...

  10. Train-borne measurements of background radiation along the railways in New Zealand

    International Nuclear Information System (INIS)

    A survey done in New Zealand to estimate the outdoor gamma-ray dose rates using a technique of an improved version of one used previously in Australia was reported together with the cosmic-ray dose rates estimated from atmospheric pressure data. A battery-operated portable digital NaI(Tl) (1''φ x 2'') scintillation survey-meter was used for measurement on board regular service of passenger trains. The calibration of count rates into absorbed dose rates was done through simultaneous measurements with a 3''φ x 2'' NaI(Tl) scintillation spectrometer at different dose levels in a natural outdoor environment. Since the survey was carried out inside the train, data were converted to ones outdoors using the regression line. Influence of cliffs, tunnels and waters was corrected by author's model based on the place of the detector. For cosmic-ray dose rates, theoretical data by O'Brien were used. The survey was performed over a period of 3 days, from 22 to 24, February 1998. The route was that from Invercargill to Auckland through Picton/Wellington which was of 1,617 km distance, of which measured data were presented graphically. The mean of the terrestrial gamma-ray dose rates was found to be 62.7 nGy/h. The data were compared with ones by Matthews and found to scatter within the range of their statistical errors, which thus suggested that the data represented the outdoor radiation levels fairly well. (K.H.)

  11. Radial collimator system for reducing background noise during neutron diffraction with area detectors

    Science.gov (United States)

    Wright, A. F.; Berneron, M.; Heathman, S. P.

    1981-04-01

    The construction and performance of an area collimator for use with film or multidetectors is described. A cylindrical assembly of high divergence slits, resembling a venetian blind, at a short distance from the sample permits the detector to observe only scattering from the sample or very close to it. Parasitic scattering from cryostats or furnaces enclosing the sample is absorbed by the slits. Homogeneity of transmission is improved by oscillating the collimator.

  12. Regional background assessment of groundwater wells in the Greater Hudson Hope Area

    International Nuclear Information System (INIS)

    The initial exploration activities for coalbed methane (CBM) development in the Hudson Hope area of British Columbia (BC) have now begun. This baseline survey of water resources was conducted as a result of concerns over the impacts of CBM development on water quality and quantity. Eight environmental monitoring sites were located and water samples were collected to analyze potability, dissolved metals, and extractable petroleum hydrocarbons. Quantity data were collected to measure static water levels as well as to obtain flow measurements on springs and creeks. The study also included a review of surficial and bedrock geology in order to identify aquifers. Risk areas were identified in order to increase monitoring activities at sites requiring higher levels of protection. Risk areas included the Peace River Terrace, which has a large fluvial deposit of gravels and sands susceptible to contamination, and the Beryl Prairie Road Corridor, which has an aquifer that flows over sedimentary bedrock and supplies water to approximately 40 dwellings. 11 refs., 1 tab., 11 figs.

  13. An investigation of the submillimeter background radiation using SCUBA and Spitzer

    CERN Document Server

    Dye, S; Ashby, M L N; Huang, J S; Webb, T M A; Barmby, P; Lilly, S; Brodwin, M; McCracken, H; Egami, E; Fazio, G G

    2005-01-01

    We investigate the redshift dependence of the contribution to the extragalactic far-infrared/sub-millimeter background from galaxies detected by the Spitzer Space Telescope at 8um and 24um. Using seven-band optical to mid-infrared photometry, we estimate photometric redshifts for the Spitzer sources which appear to be mostly L* galaxies at a median redshift of z=1.0. These sources, extracted from deep 8um and 24um mosaics of the CUDSS 14-hour field with 5sigma limits of 5.8uJy and 70uJy respectively, exhibit significant 850um and 450um emission as observed by SCUBA. At 850um, after removing >=4sigma sources and those securely identified in our previous cross-matching paper, we measure stacked flux at the significance level of 4.4sigma and 2.9sigma from the full 8um and 24um galaxy catalogue respectively. At 450um, flux is detected from all 8um galaxies at the level of 3.5sigma, while there is no significant emission from the 24um galaxies. We find that the 850um flux is emitted almost exclusively at z>~1.3 fr...

  14. The interaction of natural background gamma radiation with depleted uranium micro-particles in the human body.

    Science.gov (United States)

    Pattison, John E

    2013-03-01

    In this study, some characteristics of the photo-electrons produced when natural background gamma radiation interacts with micron-sized depleted uranium (DU) particles in the human body have been estimated using Monte Carlo simulations. In addition, an estimate has been made of the likelihood of radiological health effects occurring due to such an exposure. Upon exposure to naturally occurring background gamma radiation, DU particles in the body will produce an enhancement of the dose to the tissue in the immediate vicinity of the particles due to the photo-electric absorption of the radiation in the particle. In this study, the photo-electrons produced by a 10 μm-size particle embedded in tissue at the centre of the human torso have been investigated. The mean energies of the photo-electrons in the DU particle and in the two consecutive immediately surrounding 2 μm-wide tissue shells around the particle were found to be 38, 49 and 50 keV, respectively, with corresponding ranges of 1.3, 38 and 39 μm, respectively. The total photo-electron fluence-rates in the two consecutive 2 μm-wide tissue layers were found to be 14% and 7% of the fluence-rate in the DU particle, respectively. The estimated dose enhancement due to one 10 μm-sized DU particle in 1 cm(3) of tissue was less than 2 in 10 million of the dose received by the tissue without a particle being present. The increase in risk of death from cancer due to this effect is consequently insignificant. PMID:23295360

  15. Investigation of background radiation level in Krusadai Island Mangrove, Gulf of Mannar, India

    International Nuclear Information System (INIS)

    Natural radioactive concentration analysis was carried out in the sand sediments that were collected from the shallow inner shelf region of an ecologically sensitive mangrove forest area at Krusadai Island in Gulf of Mannar near Rameswaram, Tamil Nadu, India. A NaI (Tl) detector based gamma ray spectrometer was used for analysing the samples. The Activity concentration of the primordial radionuclide 238U was below detectable limit (BDL) for all the locations, 232Th had the range between BDL to 27.81 ± 8.9 Bq/kg while 40K had the range from BDL to 413.13 ± 49.6 Bq/kg. The other radiological parameters were calculated and all are found to be well below the prescribed limit. The study concludes that the Krusadai island mangrove forest region as a radiologically safer region for the endemic biota. (author)

  16. The concentrations of radionuclides, heavy metals, and poloychlorinated biphenyls in field mice collected from regional background areas. Revision 3

    Energy Technology Data Exchange (ETDEWEB)

    Fresquez, Philip R. [Los Alamos National Laboratory

    2016-01-21

    Field mice are effective indicators of contaminant presence. This paper reports the concentrations of various radionuclides, heavy metals, polychlorinated biphenyls, high explosives, perchlorate, and dioxin/furans in field mice (mostly deer mice) collected from regional background areas in northern New Mexico. These data, represented as the regional statistical reference level (the mean plus three standard deviations = 99% confidence level), are used to compare with data from field mice collected from areas potentially impacted by Laboratory operations, as per the Environmental Surveillance Program at Los Alamos National Laboratory.

  17. Learning from the energetic rural area. Background report; Leren van het energieke platteland. Achtergrondrapport

    Energy Technology Data Exchange (ETDEWEB)

    Arnouts, R.; Van den Born, G.J.; Daalhuizen, F.; Farjon, H.; Pols, L.; Tekelenburg, T.; Tisma, S.; Van Veen, M. [Planbureau voor de Leefomgeving PBL, Den Haag (Netherlands); Gerritsen, A.; Verburg, R. [Wageningen UR, Wageningen (Netherlands); Wiering, M. [Radboud Universiteit Nijmegen, Nijmegen (Netherlands); Roovers, G. [Oranjewoud, Heerenveen (Netherlands)

    2013-06-15

    Citizens and businesses start on a regular basis, and in cooperation with the Dutch government, initiatives to improve the living environment in rural areas. In this study, 32 examples are discussed to detect issues that can be improved. The examples concern more or less successful partnerships for sustainable rural development, in which the market, citizens and civil society play a prominent role. Four issues for improvement are identified: (1) Other accents are required in laws and regulations for the living environment; (2) The Dutch government must give smart directions by means of levies and incentives; (3) A vision of the governments is essential; and (4) Towards a proactive, facilitating government [Dutch] Burgers en bedrijven nemen regelmatig samen met overheden initiatieven om de leefomgeving op het platteland te verbeteren. In deze studie zijn 32 praktijkvoorbeelden onder de loep genomen om die verbeterpunten op te sporen. Het gaat om meer of minder succesvolle samenwerkingsverbanden voor duurzame plattelandsontwikkeling, waarin marktpartijen, burgers en het maatschappelijk middenveld een vooraanstaande rol spelen. Hierbij worden vier verbeterpunten gesignaleerd: (1) Andere accenten gewenst in wet- en regelgeving voor de leefomgeving; (2) Slimmer sturen met heffingen en vergoedingen door de overheid; (3) Visie van overheden is onontbeerlijk; en (4) Naar een proactieve, faciliterende overheid.

  18. REDUCING THE IMPACT OF RADIATION FACTORS IN AREAS WITH HIGH LEVEL OF RISK

    Directory of Open Access Journals (Sweden)

    D. A. Zaredinov

    2015-01-01

    Full Text Available The article is devoted to the modern problems of radioecology. The study reveals the problems of radioecological situation in some regions of the Republic of Uzbekistan. The main attention of the authors is paid to the ecologically hazardous objects in the uranium mining industry. The characteristics of wastes from uranium mining and stages of development of the mining industry are described. The historical background of the accumulation of the wastes in dumps, the ore-bearing rocks, and other off-balance ores is given. The practical experience and directions radio-ecological safety are generalized, achieving improvements of the environmental quality in areas with high risk. In conclusion, the authors recommend carrying out some measures to reduce an impact of the radiation factor on human health and to stabilize the radioecological situation at the studied regions.

  19. Radiative Transfer in a Clumpy Universe. IV. New Synthesis Models of the Cosmic UV/X-Ray Background

    Science.gov (United States)

    Haardt, Francesco; Madau, Piero

    2012-02-01

    We present improved synthesis models of the evolving spectrum of the UV/X-ray diffuse background, updating and extending our previous results. Five new main components are added to our radiative transfer code CUBA: (1) the sawtooth modulation of the background intensity from resonant line absorption in the Lyman series of cosmic hydrogen and helium; (2) the X-ray emission from the obscured and unobscured quasars that gives origin to the X-ray background; (3) a piecewise parameterization of the distribution in redshift and column density of intergalactic absorbers that fits recent measurements of the mean free path of 1 ryd photons; (4) an accurate treatment of the photoionization structure of absorbers, which enters in the calculation of the helium continuum opacity and recombination emissivity; and (5) the UV emission from star-forming galaxies at all redshifts. We provide tables of the predicted H I and He II photoionization and photoheating rates for use, e.g., in cosmological hydrodynamics simulations of the Lyα forest and a new metallicity-dependent calibration to the UV luminosity density-star formation rate density relation. A "minimal cosmic reionization model" is also presented in which the galaxy UV emissivity traces recent determinations of the cosmic history of star formation, the luminosity-weighted escape fraction of hydrogen-ionizing radiation increases rapidly with look-back time, the clumping factor of the high-redshift intergalactic medium evolves following the results of hydrodynamic simulations, and Population III stars and miniquasars make a negligible contribution to the metagalactic flux. The model provides a good fit to the hydrogen-ionization rates inferred from flux decrement and proximity effect measurements, predicts that cosmological H II (He III) regions overlap at redshift 6.7 (2.8), and yields an optical depth to Thomson scattering, τes = 0.084 that is in agreement with Wilkinson Microwave Anisotropy Probe results. Our new

  20. Background radiation dose-rates to non-human biota in a high mountain habitat in Norway

    DEFF Research Database (Denmark)

    Brown, J.E.; Gelsvik, R.; Kålås, J.A.;

    2009-01-01

    with activity concentrations reported for reindeer muscle sampled at proximate locations, falling at a level of some 10s of Bq kg-1 by fresh weight. Statistical analyses of the data showed that bank vole and shrew 210Po data constitute different populations with different mean ranks. Unweighted dose-rates......Determination of background radiation dose-rates is important in the process of assessing risks to the environment from exposure to human activities both in terms of deriving the incremental dose-rate and as a point of reference for evaluating the significance of the exposure level. A consideration...... attributable to the presence of internally distributed 210Po were calculated to be 0.07 μGy h-1 for Bank vole....

  1. Radiative improvement of the lattice NRQCD action using the background field method with applications to quarkonium spectroscopy

    CERN Document Server

    Hammant, T C; von Hippel, G M; Horgan, R R; Monahan, C J

    2013-01-01

    We apply the background field (BF) method to Non-Relativistic QCD (NRQCD) on the lattice in order to determine the one-loop radiative corrections to the coefficients of the NRQCD action in a manifestly gauge-covariant manner by matching the NRQCD prediction for particular on-shell processes with those of relativistic continuum QCD. We explain how the BF method is implemented in automated perturbation theory and discuss the technique for matching the relativistic and non-relativistic theories. We compute the one-loop radiative corrections to the sigma.B and Darwin terms for the NRQCD action currently used in simulations, as well as the one-loop coefficients of the spin-dependent O(alpha^2) four-fermion contact terms. The effect of the corrections on the hyperfine splitting of bottomonium is estimated using earlier simulation results; the corrected lattice prediction is found to be in agreement with experiment. Agreement of the hyperfine splitting of bottomonium and the B-meson system is confirmed by recent sim...

  2. Th-230/Th-232 sedimentation rates and the natural radiation background along the western coast of Israel

    International Nuclear Information System (INIS)

    The natural radiation background of the sediments from the southeastern province of the Levant Basin was determined by both alpha-particle spectrometry and by gamma-ray spectrometry using a specially low background high resolution Ge(Li) detector. The Nile river derived clastics dominates the sediment character along the Israeli coast. The radioelements in nine cores under the Nile's influence are readily distinguishable, having higher potassium, uranium and thorium contents, from the more carbonate rich sediments investigated in three cores from the northwestern province of the Levant Basin. Significant fluctuations exist in the radiometal content with depth within individual cores. The rate of sediment transport and deposition are so rapid that no Th-230 excess accumulated in the sediment deposited relatively nearshore. In the deep water of the Herodotus Basin only a small degree of Th-230 excess is recorded. Determination of absolute rates of sedimentation by uranium series disequilibria is not feasible for the sediments near to the Israeli coast, while such studies in the Herodotus Basin would require long core lengths to succeed

  3. Radiative transfer in a clumpy universe: IV. New synthesis models of the cosmic UV/X-ray background

    CERN Document Server

    Haardt, Francesco

    2011-01-01

    We present improved synthesis models of the evolving spectrum of the UV/X-ray diffuse background, updating and extending our previous results. Five new main components are added to our radiative transfer code CUBA: (1) the sawtooth modulation of the background intensity from resonant line absorption in the Lyman series of cosmic hydrogen and helium; (2) the X-ray emission from obscured and unobscured quasars; (3) a piecewise parameterization of the distribution in redshift and column density of intergalactic absorbers that fits recent measurements of the mean free path of 1 ryd photons; (4) an accurate treatment of the photoionization structure of absorbers; and (5) the UV emission from star-forming galaxies at all redshifts. We provide tables of the predicted HI and HeII photoionization and photoheating rates for use, e.g., in cosmological hydrodynamics simulations of the Lya forest, and a new metallicity-dependent calibration to the UV luminosity density-star formation rate density relation. A "minimal cosm...

  4. JEM-X background models

    DEFF Research Database (Denmark)

    Huovelin, J.; Maisala, S.; Schultz, J.;

    2003-01-01

    revolution 41 of INTEGRAL. Total observing time used for the analysis was 216 502 s, with the average of 25 cps of background for each of the two JEM-X telescopes. JEM-X1 showed slightly higher average background intensity than JEM-X2. The detectors were stable during the long exposures, and weak orbital...... phase dependence in the background outside radiation belts was observed. The analysis yielded an average of 5 cps for the diffuse background, and 20 cps for the instrument background. The instrument background was found highly dependent on position, both for spectral shape and intensity. Diff use...... background was enhanced in the central area of a detector, and it decreased radially towards the edge, with a clear vignetting effect for both JEM-X units. The instrument background was weakest in the central area of a detector and showed a steep increase at the very edges of both JEM-X detectors, with...

  5. Atmospheric carbon tetrachloride in rural background and industry surrounded urban areas in Northern Iberian Peninsula: Mixing ratios, trends, and potential sources.

    Science.gov (United States)

    de Blas, Maite; Uria-Tellaetxe, Iratxe; Gomez, Maria Carmen; Navazo, Marino; Alonso, Lucio; García, Jose Antonio; Durana, Nieves; Iza, Jon; Ramón, Jarol Derley

    2016-08-15

    Latest investigations on atmospheric carbon tetrachloride (CTC) are focused on its ozone depleting potential, adverse effects on the human health, and radiative efficiency and Global Warming Potential as a greenhouse gas. CTC mixing ratios have been thoroughly studied since its restriction under the Montreal Protocol, mostly in remote areas with the aim of reporting long-term trends after its banning. The observed decrease of the CTC background mixing ratio, however, was not as strong as expected. In order to explain this behavior CTC lifetime should be adjusted by estimating the relative significance of its sinks and by identifying ongoing potential sources. Looking for possible sources, CTC was measured with high-time resolution in two sites in Northern Spain, using auto-GC systems and specifically developed acquisition and processing methodologies. The first site, Bilbao, is an urban area influenced by the surrounding industry, where measurements were performed with GC-MSD for a one-year period (2007-2008). The second site, at Valderejo Natural Park (VNP), is a rural background area where measurements were carried out with GC-FID and covering CTC data a nonsuccessive five-year period (2003-2005, 2010-2011, and 2014-2015years). Median yearly CTC mixing ratios were slightly higher in the urban area (120pptv) than in VNP (80-100pptv). CTC was reported to be well mixed in the atmosphere and no sources were noticed to impact the rural site. The observed long-term trend in VNP was in agreement with the estimated global CTC emissions. In the urban site, apart from industrial and commercial CTC sources, chlorine-bleach products used as cleaning agents were reported as promotors of indoor sources. PMID:27092418

  6. Investigation of background in large-area neutron detectors due to alpha emission from impurities in aluminium

    CERN Document Server

    Birch, J; Clergeau, J -F; van Esch, P; Ferraton, M; Guerard, B; Hall-Wilton, R; Hultman, L; Höglund, C; Jensen, J; Khaplanov, A; Piscitelli, F

    2015-01-01

    Thermal neutron detector based on films of $^{10}$B$_4$C have been developed as an alternative to $^3$He detectors. In particular, The Multi-Grid detector concept is considered for future large area detectors for ESS and ILL instruments. An excellent signal-to-background ratio is essential to attain expected scientific results. Aluminium is the most natural material for the mechanical structure of of the Multi-Grid detector and other similar concepts due to its mechanical and neutronic properties. Due to natural concentration of $\\alpha$ emitters, however, the background from $\\alpha$ particles misidentified as neutrons can be unacceptably high. We present our experience operating a detector prototype affected by this issue. Monte Carlo simulations have been used to confirm the background as $\\alpha$ particles. The issues have been addressed in the more recent implementations of the Multi-Grid detector by the use of purified aluminium as well as Ni-plating of standard aluminium. The result is the reduction in...

  7. Variation Characteristics of Hydrothermal Resources Effectiveness Under the Background of Climate Change in Southern Rice Production Area of China

    Institute of Scientific and Technical Information of China (English)

    YE Qing; YANG Xiao-guang; DAI Shu-wei; LI Yong; GUO Jian-ping

    2013-01-01

    The spatiotemporal characteristics of hydrothermal resources in southern rice production area of China have changed under the background of climate change, and this change would affect the effectiveness of hydrothermal resources during local rice growing period. According to the cropping system subdivision in southern rice production area of China during 1980s, this study used climate data from 254 meteorological stations and phonological data from 168 agricultural observation stations in the south of China, and adopted 6 international evaluation indices about the effectiveness of hydrothermal resources to analyze the temporal and spatial characteristics of hydrothermal resources during the growing period of single cropping rice system and double cropping rice system for 16 planting zones in the whole study area. The results showed that: in southern rice production area of China, the effectiveness of thermal resources of single cropping rice area (SCRA) was less than that of double cropping rice area (DCRA), whereas the effectiveness of thermal resources of both SARA and DCRA showed a decreasing trend. The index value of effective precipitation satisfaction of SCRA was higher than that of DCRA, nevertheless the index value of effective precipitation satisfaction of both SCRA and DCRA showed a decreasing trend. There was a signiifcant linear relationship between effective thermal resource and water demand, likely water demand increased by 18 mm with every 100°C d increase of effective heat. Effective precipitation satisfaction index (EPSI) showed a negative correlation with effective heat, yet showed a positive correlation with effective precipitation. EPSI reduced by 1% when effective heat resource increased by 125°C d. This study could provide insights for policy makers, land managers or farmers to improve water and heat resource uses and rationally arrange rice production activities under global climate change condition.

  8. Citizen radiation monitoring program for the TMI area

    Energy Technology Data Exchange (ETDEWEB)

    Baratta, A.J.; Gricar, B.G.; Jester, W.A.

    1981-07-01

    The purpose of the program was to develop a system for citizens to independently measure radiation levels in and around their communities. This report describes the process by which the Program was developed and operated. It also presents the methods used to select and train the citizens in making and interpreting the measurements. The test procedures used to select the equipment for the program are described as are the results of the testing. Finally, the actual monitoring results are discussed along with the citizens' reactions to the program.

  9. Citizen radiation monitoring program for the TMI area

    International Nuclear Information System (INIS)

    The purpose of the program was to develop a system for citizens to independently measure radiation levels in and around their communities. This report describes the process by which the Program was developed and operated. It also presents the methods used to select and train the citizens in making and interpreting the measurements. The test procedures used to select the equipment for the program are described as are the results of the testing. Finally, the actual monitoring results are discussed along with the citizens' reactions to the program

  10. Delimitation of Areas of Environmental Conflicts on the Background of Geological Conditions, Exemplified by Stary Sącz Commune

    Directory of Open Access Journals (Sweden)

    Gałaś Slávka

    2014-12-01

    Full Text Available Delimitation and characterization of areas of conflict are essential to assess suitability of land for different activities carried out in the field of rational land use. In the paper, delimitation of the conflict areas and conflicts categorization in terms of possibility of their overcoming, the scale of the range and the period of their occurrence exemplified by urban - rural commune Stary Sącz have been presented. The software ArcGIS 10.1, the method of maps superimposing and analysis of interactions between different geoenvironmental factors have been applied to obtain the goal of the investigation. Specific geological structure together with morphological and climatic conditions in Stary Sącz commune create ideal conditions for occurrence of con-flict areas on the background of the geological conditions. Accurate and early recognition of these conflicts - existing and potential ones, is a prerequisite for the environmental risk prevention and elimination of its effects through the proper preparation of planning documents and development plans and programs.

  11. The annual terrestrial gamma radiation dose to the population of the urban Christchurch area

    International Nuclear Information System (INIS)

    Natural terrestrial gamma radiation dose rates were measured with a high pressure ionization chamber at 70 indoor (195 site measurements) and 58 outdoor locations in the metropolitan Christchurch area. Based on these site measurements, the average gonad dose rate to the population from natural terrestrial gamma radiation was estimated to be 273+-56 microgray per annum. (auth)

  12. Environmental radiation monitoring plan for depleted uranium and beryllium areas, Yuma Proving Ground

    International Nuclear Information System (INIS)

    This Environmental Radiation Monitoring Plan (ERM) discusses sampling soils, vegetation, and biota for depleted uranium (DU) and beryllium (Be) at Yuma Proving Ground (YPG). The existing ERM plan was used and modified to more adequately assess the potential of DU and Be migration through the YPG ecosystem. The potential pathways for DU and Be migration are discussed and include soil to vegetation, soil to animals, vegetation to animals, animals to animals, and animals to man. Sample collection will show DU deposition and will be used to estimate DU migration. The number of samples from each area varies and depends on if the firing range of interest is currently used for DU testing (GP 17A) or if the range is not used currently for DU testing (GP 20). Twenty to thirty-five individual mammals or lizards will be sampled from each transect. Air samples and samples of dust in the air fall will be collected in three locations in the active ranges. Thirty to forty-five sediment samples will be collected from different locations in the arroys near the impact areas. DU and Be sampling in the Hard Impact and Soft Impact areas changed only slightly from the existing ERM. The modifications are changes in sample locations, addition of two sediment transport locations, addition of vegetation samples, mammal samples, and air sampling from three to five positions on the impact areas. Analysis of samples for DU or total U by inductively-coupled mass spectroscopy (ICP/MS), cc spectroscopy, neutron activation analysis (NAA), and kinetic phosphorimetric analysis (KPA) are discussed, and analysis for Be by ICP/MS are recommended. Acquiring total U (no isotope data) from a large number of samples and analysis of those samples with relatively high total U concentrations results in fewer isotopic identifications but more information on U distribution. From previous studies, total U concentrations greater than about 3 times natural background are usually DU by isotopic confirmation

  13. A study of ultraviolet solar radiation at Cairo urban area, Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Robaa, S.M. [Cairo Univ., Giza (Egypt). Dept. of Astronomy and Meterology

    2004-07-01

    The monthly mean values of global, G, and ultraviolet, UV, solar radiation incident on a horizontal surface at Cairo urban area during the two different periods (1969-1973) and (1993-1997) are presented, analyzed and compared. The effect of urbanization processes on the solar radiation components is investigated and discussed. It was found that the total radiation of the two components, G and UV received at the urban area of Cairo during the period (1969-1973) highly exceeds the radiation received during the period (1993-1997) for all months of the year. The mean relative reduction of G and UV reached 17.4% and 27.4% respectively. A significant correlation between G and UV radiation has been established and the recommended correlation equation has been stated to estimate the values of UV radiation that are difficult to measure at any site in the zone of Lower Egypt. Also, a comparative study of the two radiation components, G and UV, at urban (Cairo) and rural (Bahtim) areas during the period (1993-1997) revealed that the urban area always has values of G and UV radiation distinctly lower than that found in rural area for all months of the year. Urban-rural mean reduction of G and UV reached 7.0% and 17.9% respectively. The ratio of the ultraviolet to global radiation (UV/G) are calculated and compared with other sites in the Arabian Peninsula. The effect of atmospheric dust on the measured solar radiation components is also investigated and discussed. (author)

  14. Ecological and human impact assessment in the legacy enhanced and naturally occurring radiation areas - human and ecological impact assessment in the legacy enhanced and naturally occurring radiation areas

    Energy Technology Data Exchange (ETDEWEB)

    Mrdakovic Popic, Jelena [Norwegian Radiation Protection Authority, P.O. Box 55, N-1332 Oesteraas (Norway); Salbu, Brit; Skipperud, Lindis [Norwegian University of Life Sciences, Centre for Environmental radioactivity CERAD, P.O. Box 5003, 1430 Aas (Norway)

    2014-07-01

    dose could reach 20 mSv, what is given as limit for occupational radiation exposure (UNSCEAR, ICRP). However, existing uncertainties in dose estimation must be considered. To assess the impacts on biota, wild plant species, free-living earthworm species, wild berries and mushrooms were collected from both former mining sites (legacy NORM) and undisturbed NOR rich sites. Biota levels of radionuclides ({sup 232}Th and {sup 238}U as well daughters {sup 228}Ra, {sup 228}Th, {sup 226}Ra and {sup 210}Po) were in accordance with worldwide published literature, but actual transfer was lower than expected from total soil activity concentrations. Radiation dose rates, calculated by the ERICA Tool with site-specific data, were in range 2.3 - 10.8 μGy/h, with maximal value estimated for lichen and bryophytes. Although higher than typical background dose range of terrestrial organisms 0.02 - 0.44 μG/h, biota exposure doses do not implicate any risk. The radionuclide main contributor to the dose was {sup 228}Th. Based on overall results, several 'hot spots' in the Fen Complex were identified including both legacy NORM and undisturbed NOR rich sites and consideration of intervention actions is recommended. (authors)

  15. NCRP Program Area Committee 5: Environmental Radiation and Radioactive Waste Issues.

    Science.gov (United States)

    Chen, S Y; Napier, Bruce

    2016-02-01

    Program Area Committee 5 of the National Council on Radiation Protection and Measurements (NCRP) focuses its activities on environmental radiation and radioactive waste issues. The Committee completed a number of reports in these subject areas, most recently NCRP Report No. 175, Decision Making for Late-Phase Recovery from Major Nuclear or Radiological Incidents. Historically this Committee addressed emerging issues of the nation pertaining to radioactivity or radiation in the environment or radioactive waste issues due either to natural origins or to manmade activities. PMID:26717160

  16. NCRP Program Area Committee 5: Environmental Radiation and Radioactive Waste Issues

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shih-Yew; Napier, Bruce A.

    2016-02-18

    The Program Area Committee 5 (PAC 5) of the National Council on Radiation protection and Measurements (NCRP) focuses its activities on environmental radiation and radioactive waste issues. The committee completed a number of reports in the subject areas, and specifically the most recent NCRP Report 175 (Decision Making for Late-Phase Recovery from Major Nuclear or Radiological Incidents). Historically PAC 5 addressed the emerging issues of the nation that pertain to radioactivity or radiation in the environment, or the radioactive waste issues due either to the natural origins or to the manmade activities

  17. Large area radiation detectors based on II VI thin films

    Science.gov (United States)

    Quevedo-Lopez, Manuel

    2015-03-01

    The development of low temperature device technologies that have enabled flexible displays also present opportunities for flexible electronics and flexible integrated systems. Of particular interest are possible applications in flexible, low metal content, sensor systems for unattended ground sensors, smart medical bandages, electronic ID tags for geo-location, conformal antennas, neutron/gamma-ray/x-ray detectors, etc. In this talk, our efforts to develop novel CMOS integration schemes, circuits, memory, sensors as well as novel contacts, dielectrics and semiconductors for flexible electronics are presented. In particular, in this presentation we discuss fundamental materials properties including crystalline structure, interfacial reactions, doping, etc. defining performance and reliability of II-VI-based radiation sensors. We investigate the optimal thickness of a semiconductor diode for thin-film solid state thermal neutron detectors. Besides II-VI materials, we also evaluated several diode materials, Si, CdTe,GaAs, C (diamond), and ZnO, and two neutron converter materials,10B and 6LiF. We determine the minimum semiconductor thickness needed to achieve maximum neutron detection efficiency. By keeping the semiconductor thickness to a minimum, gamma rejection is kept as high as possible. In this way, we optimize detector performance for different thin-film semiconductor materials.

  18. Radiation protection study of radiology medical workers in radiodiagnosis area

    International Nuclear Information System (INIS)

    Aspects related to radiological safety and its organization in radiodiagnosis were evaluated by means of scanning carried out in 18 hospitals of Mexico City, divided in 11 public institutions and 7 private ones. The population being studied was: hospital personnel that works in radiodiagnosis. The survey was made with 31 dichotomic variables, being obtained 132 surveys. The personnel characteristics are 83% works in public institutions, 49% works in radiodiagnosis, 3% has an academic degree, 13% is member of a hospital professional association, 13% has updated information on radiological protection, 36% was trained, 45% works for more than 2 years, 52% uses personal dosemeter, less than the 20% knows about the fundamentals of the radiological protection and 24% states to suffer from biological radiation effects, due to the exposure to x-rays. As result of the study, it was found that the main problems that the radiological protection has, are: lack of training programs in radiological protection and supervision, medical surveillance and the few number of persons that takes part in clinical meetings and professional associations. (authors). 7 refs., 3 tabs

  19. 105KE Basin Area Radiation Monitor System (ARMS) Acceptance Test Procedure

    CERN Document Server

    Kinkel, C C

    1999-01-01

    This procedure is intended for the Area Radiation Monitoring System, ARMS, that is replacing the existing Programmable Input-Output Processing System, PIOPS, radiation monitoring system in the 105KE basin. The new system will be referred to as the 105KE ARMS, 105KE Area Radiation Monitoring System. This ATP will ensure calibration integrity of the 105KE radiation detector loops. Also, this ATP will test and document the display, printing, alarm output, alarm acknowledgement, upscale check, and security functions. This ATP test is to be performed after completion of the 105KE ARMS installation. The alarm outputs of the 105KE ARMS will be connected to the basin detector alarms, basin annunciator system, and security Alarm Monitoring System, AMS, located in the 200 area Central Alarm Station (CAS).

  20. Minimizing the background radiation in the new neutron time-of-flight facility at CERN FLUKA Monte Carlo simulations for the optimization of the n_TOF second experimental line

    CERN Document Server

    Bergström, Ida; Elfgren, Erik

    2013-06-11

    At the particle physics laboratory CERN in Geneva, Switzerland, the Neutron Time-of-Flight facility has recently started the construction of a second experimental line. The new neutron beam line will unavoidably induce radiation in both the experimental area and in nearby accessible areas. Computer simulations for the minimization of the background were carried out using the FLUKA Monte Carlo simulation package. The background radiation in the new experimental area needs to be kept to a minimum during measurements. This was studied with focus on the contributions from backscattering in the beam dump. The beam dump was originally designed for shielding the outside area using a block of iron covered in concrete. However, the backscattering was never studied in detail. In this thesis, the fluences (i.e. the flux integrated over time) of neutrons and photons were studied in the experimental area while the beam dump design was modified. An optimized design was obtained by stopping the fast neutrons in a high Z mat...

  1. Assessment of radioactivity and estimation of effective dose received by villagers residing at natural high background areas of coastal regions of Tamil Nadu

    International Nuclear Information System (INIS)

    Radiation exposure and effective dose received by villagers residing at seven villages belonging to Natural High Background Radiation Areas (NHBRA) of coastal regions of Tamil Nadu were studied; five houses in each village were selected. The NHBRA villages were Chinnavilai, Periavilai, Kottilpadu, Puthoor Colachel, Kodimunai and Midalam. The houses were of similar construction pattern (brick wall-tiled roof, cement flooring). Measurements of radon (222Rn), thoron (220Rn) and their progeny, produced by the decay of naturally occurring radioisotopes uranium and thorium in dwellings are the largest contributor to the average internal effective dose received by human beings. Internal doses due to radon/thoron and their progeny were estimated using, Solid State Nuclear Track Detectors (SSNTD), LR-115, as the detector. External doses were estimated by gamma measurement using scintillometer and Thermo Luminescent Dosimeter (TLD). TLDs were exposed for one year, on a quarterly basis, inside the house at a height of 3 meters and about 1 meter away from the walls. The SSNTD cups were exposed adjacent to the TLDS, and the exposure was for a period of three months each. The SSNTDs were developed by standard procedures (10% NaOH, etching for 90 min at 60 deg C) and counted in a spark counter. Earlier the SSNTDs were calibrated using U and Th sources and calibration factors were obtained. Inhalation dose due to 232Th and Th (B) in mWL were estimated by collecting air samples from each house, for one hour each, during the replacement time of TLD and SSNTD Cups. For inhalation dose estimation the occupancy factor was assumed to be 0.8. The soil samples were also collected from each sampling point. (author)

  2. Modbus based smart radiation monitoring network of area gamma monitors

    International Nuclear Information System (INIS)

    With the advent of Low cost microprocessors/micro controllers and VLSI based ASIPs, the field of instrumentation is undergoing a rapid change. Connectivity of a remote computer to the instruments for accessing the data and other diagnostic information has become one of the important requirements of all modern instruments, in addition to providing accurate measurement data. This is more so, in case of those instruments, which are located in some hostile environments such as radioactive zones of nuclear power reactor. The details of a network of Area Gamma Monitors (AGM) using the modbus protocol, are presented in this paper. The paper highlights the details of the AGM, protocol implementation and the windows based graphical user interface, implemented on a PC that can act as a master node, for interacting with various AGMs on the network. (author)

  3. AA, radiation shielding curtain along the target area

    CERN Multimedia

    1980-01-01

    At the far left is the beam tube for the high-intensity proton beam from the 26 GeV PS. The tube ends in a thin window and the proton beam continues in air through a hole in the shielding blocks (see also 8010308), behind which the target (see 7905091, 7905094)was located. After the target followed the magnetic horn, focusing the antiprotons, and the first part of the injection line with a proton dump. The antiprotons, deflected by a magnet, left the target area through another shielding wall, to make their way to the AA ring. Laterally, this sequence of components was shielded with movable, suspended, concrete blocks: the "curtain". Balasz Szeless, who had constructed it, is standing at its side.

  4. Th, U, Ra and rare earth element distributions in farm animal tissues from an elevated natural radiation background environment

    International Nuclear Information System (INIS)

    A field study was conducted in an area of elevated natural background radioactivity (the Pocos de Caldas plateau, Brazil) to assess tissue concentrations and the comparative bioavailability of isotopic Th (IV), U (IV, VI), Ra (II) and light rare earth elements (REE), i.e. La (III) and Ce (III, IV) in adult steers, pigs and chickens. The assessment of comparative bioavailability was aided by normalizing tissue concentrations to local soil concentrations, i.e. by calculating soil-to-tissue concentration ratios (CRs). Mean CRs (for muscle/soil) in these animals were very similar for U, La and Th which, as a group, decreased among the farm animals sampled as (all x 10-4): chicken (1) ≥ steer (0.7) ≥ pig (0.4). For 226Ra, CRs in muscle decreased in the same order among animals although mean values were 3-5 times greater than those quoted. Much greater values and greater differences among the elements are noted for bone/soil CRs, which for all animals decreased as: Ra >> U > La=Th, indicating the order of elemental bioavailability (assuming bone to be the major retention compartment). Isotopic ratios in farm animal tissue are shown to resemble closely those in soils over which the animals forage, with few exceptions, indicating the importance of the soil component in the transfer of these elements to tissues. (author)

  5. Networked solutions of radiation control of state borders and urban areas

    International Nuclear Information System (INIS)

    Full text: Prevention of illicit trafficking in radioactive and nuclear materials through state borders as well as the disperse of radioactive materials in urban area is a challenging task of national security departments in many countries. To solve this task, appropriate actions of personnel on-site equipped by radiation detectors such as fixed radiation portal monitors or mobile personal radiation detectors are required. However, users of radiation equipment such as Customs, Border Guard and Police Services often perform radiation control as additional responsibility to their main duties. Furthermore, these users have no sufficient expertise in radiation control and need real-time remote expert help to interpret readings of radiation equipment and expert support in decision making process. Polimaster has developed complete solution called Nuclear Protection Network system (NPNET) for high-effective radiation control on State Borders as well as inside a country. NPNET system intended for efficient interaction and on-line data exchange between a user, radiation control instrument, for example a personal radiation detector or radioisotope identifier, and remote Command Center. Availability of such system allows to solve more efficiently tasks of detection, localization and identification of ionizing radiation sources, to properly interpret false alarms (e.g. at detention of a passenger having passed radio-therapy etc.) and effectively prevent illicit trafficking radioactive and nuclear materials. The NPNET system can cover territory as large as city or even a state and provides assistant of infinite number of independent user groups. NPNET has a module structure and could be easily adapted to any specific user's requirements. Thus, the radiation mobile system NPNET is an effective tool for prevention of illicit trafficking of nuclear and radioactive materials and is recommended for use by Border guards, Customs, Securities and emergency situations services. (author)

  6. Radon and radium in ground water and atmosphere in high background areas of twin cities of Hyderabad and Secunderabad

    International Nuclear Information System (INIS)

    A study of levels of radium and radon levels in ground water of different areas of the city is taken up. Seasonal and diurnal variation in radon concentration in air at a location was also measured. Emanometry technique is used for estimation of Radium and measurement of dissolved radon in water. For radon concentration in atmosphere Low Level Radon Detection System is used. Prevailing radiation levels at 32 location in the cities of Hyderabad and Secunderabad which were covered in this study varied between 0.124 µGy/hr to 0.36 µGy/hr. 13 locations were above 0.20 µGy/hr where as rest are in below 0.20 µGy/hr. 45 bore well water samples were collected from 32 Locations and were analysed for radium concentration. The values were found to be in the range of 4.64 to 20843.01 Bq/ m3. Of which 3 samples were found to have concentration above 10,000 Bq/m3. 2 samples are in the range of 1000 - 10000 Bq/m3. 14 sample are having in the range of 100-1000 Bq/m3. Rest of 23 samples were less than 100 Bq/m3. The water samples of different bore wells in Kushaiguda area of Hyderabad were analysed for dissolved radon. Samples from 14 locations were collected for estimation of dissolved radon concentration in the water. The concentration was found to be in the range of 51 Bq/m3 to 231301 Bq/m3. Of these 9 samples were having concentration above 100000 Bq/m3. 4 samples are in the range of 10000 - 100000 Bq/m3. 4 samples are in the range of 1000 - 10000 Bq/m3. And rest 5 samples were less than 1000 Bq/m3. An study of seasonal variation in atmospheric radon concentration was conducted at one location for over a year. All measurements were done during day time only. Around 1.6 time increase in atmospheric radon concentration was observed in winter months as compared to that in summer months. Similar ratio was observed when data for forenoon and afternoon were compared separately. The study has confirmed the occurrence of high radium and radon concentration in ground water samples

  7. Diversity of albedo and longwave exchange and radiative efficiency coefficients on Bledow Desert area

    International Nuclear Information System (INIS)

    In the vegetation seasons of 2001 and 2002, comprehensive meteorological and biological research was carried out in the selected sandy areas of the Błędów Desert, located in the Silesia Upland. The article presents part of a research concerning solar radiation, radiative efficiency, longwave exchange and albedo coefficients, which are elements used for the evaluation and comparison of active surface. The course and spatial distribution of individual elements of the radiation balance and the above-mentioned coefficients were analysed for surfaces representative of the Błędów Desert. Due to its easy determination, the albedo coefficient is the most often used determinant for the characteristics of an active surface for the research of short-wave radiation balance. Its values are between 0.1 for dark or damp areas and 0.4 for light sand. On sandy surfaces covered with organic substance or initial vegetation, the longwave exchange coefficient reaches the value of 0.54, which is much higher than on a sandy surface (0.37). The third of the researched indexes is the radiative efficiency coefficient, which is sensitive to environmental features due to the exchange of longwave streams of active surface. Nevertheless, it was found that the radiative efficiency coefficient shows little sensitivity for sandy and dry areas in the range between -0.32 and -0.35. (author)

  8. Assessment of a relative contribution of terrestrial background radiation in the test field by using RADIAGEMTM 2000 portable survey meter

    Directory of Open Access Journals (Sweden)

    Avdić Senada

    2016-01-01

    Full Text Available This study is focused on the radiological investigation of terrestrial gamma radiation in the test field with soil samples from different minefields in the Federation of Bosnia and Herzegovina. Measurements of ambient dose equivalent rate, commonly referred to as “air dose rate”, in the test field located in the Tuzla Canton, were performed by RADIAGEMTM 2000 portable survey meter, based on energy-compensated Geiger-Muller counter. Its performances were tested in the laboratory conditions with gamma point sources. Since all the samples in the test field were exposed to the same cosmic radiation, there was a possibility to assess a relative contribution of terrestrial gamma radiation due to soil samples of different composition. One set of measurements in the test field was performed with RADIAGEMTM 2000, at a height of about one meter above the ground and basic statistical parameters indicated that there was no significant difference of terrestrial gamma radiation from different soil samples. The other set of measurements was carried out with the same device placed on the ground in the test field. Processing of experimental data on terrestrial gamma radiation has shown that it was possible to make a difference between relative contributions of terrestrial gamma radiation from individual soil samples. The results of investigation could be useful for multiple purposes of public interest.

  9. Resolving the Extragalactic γ-Ray Background above 50 GeV with the Fermi Large Area Telescope.

    Science.gov (United States)

    Ackermann, M; Ajello, M; Albert, A; Atwood, W B; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Bissaldi, E; Blandford, R D; Bloom, E D; Bonino, R; Bregeon, J; Britto, R J; Bruel, P; Buehler, R; Caliandro, G A; Cameron, R A; Caragiulo, M; Caraveo, P A; Cavazzuti, E; Cecchi, C; Charles, E; Chekhtman, A; Chiang, J; Chiaro, G; Ciprini, S; Cohen-Tanugi, J; Cominsky, L R; Costanza, F; Cutini, S; D'Ammando, F; de Angelis, A; de Palma, F; Desiante, R; Digel, S W; Di Mauro, M; Di Venere, L; Domínguez, A; Drell, P S; Favuzzi, C; Fegan, S J; Ferrara, E C; Franckowiak, A; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Giglietto, N; Giommi, P; Giordano, F; Giroletti, M; Godfrey, G; Green, D; Grenier, I A; Guiriec, S; Hays, E; Horan, D; Iafrate, G; Jogler, T; Jóhannesson, G; Kuss, M; La Mura, G; Larsson, S; Latronico, L; Li, J; Li, L; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Magill, J; Maldera, S; Manfreda, A; Mayer, M; Mazziotta, M N; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Negro, M; Nuss, E; Ohsugi, T; Okada, C; Omodei, N; Orlando, E; Ormes, J F; Paneque, D; Perkins, J S; Pesce-Rollins, M; Petrosian, V; Piron, F; Pivato, G; Porter, T A; Rainò, S; Rando, R; Razzano, M; Razzaque, S; Reimer, A; Reimer, O; Reposeur, T; Romani, R W; Sánchez-Conde, M; Schmid, J; Schulz, A; Sgrò, C; Simone, D; Siskind, E J; Spada, F; Spandre, G; Spinelli, P; Suson, D J; Takahashi, H; Thayer, J B; Tibaldo, L; Torres, D F; Troja, E; Vianello, G; Yassine, M; Zimmer, S

    2016-04-15

    The Fermi Large Area Telescope (LAT) Collaboration has recently released a catalog of 360 sources detected above 50 GeV (2FHL). This catalog was obtained using 80 months of data re-processed with Pass 8, the newest event-level analysis, which significantly improves the acceptance and angular resolution of the instrument. Most of the 2FHL sources at high Galactic latitude are blazars. Using detailed Monte Carlo simulations, we measure, for the first time, the source count distribution, dN/dS, of extragalactic γ-ray sources at E>50  GeV and find that it is compatible with a Euclidean distribution down to the lowest measured source flux in the 2FHL (∼8×10^{-12}  ph cm^{-2} s^{-1}). We employ a one-point photon fluctuation analysis to constrain the behavior of dN/dS below the source detection threshold. Overall, the source count distribution is constrained over three decades in flux and found compatible with a broken power law with a break flux, S_{b}, in the range [8×10^{-12},1.5×10^{-11}]  ph cm^{-2} s^{-1} and power-law indices below and above the break of α_{2}∈[1.60,1.75] and α_{1}=2.49±0.12, respectively. Integration of dN/dS shows that point sources account for at least 86_{-14}^{+16}% of the total extragalactic γ-ray background. The simple form of the derived source count distribution is consistent with a single population (i.e., blazars) dominating the source counts to the minimum flux explored by this analysis. We estimate the density of sources detectable in blind surveys that will be performed in the coming years by the Cherenkov Telescope Array. PMID:27127954

  10. Resolving the Extragalactic γ -Ray Background above 50 GeV with the Fermi Large Area Telescope

    Science.gov (United States)

    Ackermann, M.; Ajello, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bregeon, J.; Britto, R. J.; Bruel, P.; Buehler, R.; Caliandro, G. A.; Cameron, R. A.; Caragiulo, M.; Caraveo, P. A.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Cohen-Tanugi, J.; Cominsky, L. R.; Costanza, F.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; Digel, S. W.; Di Mauro, M.; Di Venere, L.; Domínguez, A.; Drell, P. S.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Godfrey, G.; Green, D.; Grenier, I. A.; Guiriec, S.; Hays, E.; Horan, D.; Iafrate, G.; Jogler, T.; Jóhannesson, G.; Kuss, M.; La Mura, G.; Larsson, S.; Latronico, L.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Magill, J.; Maldera, S.; Manfreda, A.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Negro, M.; Nuss, E.; Ohsugi, T.; Okada, C.; Omodei, N.; Orlando, E.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Petrosian, V.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Reposeur, T.; Romani, R. W.; Sánchez-Conde, M.; Schmid, J.; Schulz, A.; Sgrò, C.; Simone, D.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Suson, D. J.; Takahashi, H.; Thayer, J. B.; Tibaldo, L.; Torres, D. F.; Troja, E.; Vianello, G.; Yassine, M.; Zimmer, S.

    2016-04-01

    The Fermi Large Area Telescope (LAT) Collaboration has recently released a catalog of 360 sources detected above 50 GeV (2FHL). This catalog was obtained using 80 months of data re-processed with Pass 8, the newest event-level analysis, which significantly improves the acceptance and angular resolution of the instrument. Most of the 2FHL sources at high Galactic latitude are blazars. Using detailed Monte Carlo simulations, we measure, for the first time, the source count distribution, d N /d S , of extragalactic γ -ray sources at E >50 GeV and find that it is compatible with a Euclidean distribution down to the lowest measured source flux in the 2FHL (˜8 ×10-12 ph cm-2 s-1 ). We employ a one-point photon fluctuation analysis to constrain the behavior of d N /d S below the source detection threshold. Overall, the source count distribution is constrained over three decades in flux and found compatible with a broken power law with a break flux, Sb, in the range [8 ×10-12,1.5 ×10-11] ph cm-2 s-1 and power-law indices below and above the break of α2∈[1.60 ,1.75 ] and α1=2.49 ±0.12 , respectively. Integration of d N /d S shows that point sources account for at least 8 6-14+16% of the total extragalactic γ -ray background. The simple form of the derived source count distribution is consistent with a single population (i.e., blazars) dominating the source counts to the minimum flux explored by this analysis. We estimate the density of sources detectable in blind surveys that will be performed in the coming years by the Cherenkov Telescope Array.

  11. Dependence of regular background noise of VLF radiation and thunder-storm activity on solar wind proton density

    International Nuclear Information System (INIS)

    Correlation of the intensity of slowly changing regular background noise within 9.7 kHz frequency in Yakutsk (L = 3) and of the solar wind density protons was determined. This result explains the reverse dependence of the intensity of the regular background noise on the solar activity, 27-day frequency, increase before and following geomagnetic storms, absence of relation with Kp index of geomagnetic activity. Conclusion is made that growth of density of the solar wind protons results in increase of the regular background noise and thunderstorm activity

  12. Recent radiation of Brachystelma and Ceropegia (Apocynaceae) across the Old World against a background of climatic change.

    Science.gov (United States)

    Bruyns, P V; Klak, C; Hanáček, P

    2015-09-01

    The genera Brachystelma Sims and Ceropegia L. of the Ceropegieae (Apocynaceae-Asclepiadoideae) consist of ±320 species of geophytes and slender climbers with a tendency to stem-succulence in Ceropegia. They occur in and around the semi-arid, mainly tropical parts of the Old World. For 146 species (around half of the total) from most of the geographic range of the genera, we analysed data from two nuclear and five plastid regions. The evolution of Ceropegia is very complex, with at least 13 mostly well-supported lineages, one of which is sister to the ±350 species of stapeliads. Species of Brachystelma have evolved at least four times, with most of them nested within two separate major lineages. So, neither Brachystelma nor Ceropegia is monophyletic. We recover a broad trend, in two separate major lineages, from slender climbers to small, geophytic herbs. Several clades are recovered in which all species possess an underground tuber. Small, erect, non-climbing, geophytic species of Ceropegia with a tuber are nested among species of Brachystelma. Consequently, the distinctive tubular flowers used to define Ceropegia do not reflect relationships. This re-iterates the great floral plasticity in the Ceropegieae, already established for the stapeliads. Both major lineages exhibit a trend from tubular flowers with faint, often fruity odours, pollinated by very small Dipteran flies, to flatter flowers often with a bad odour, pollinated by larger flies. Most of the diversity in Brachystelma and Ceropegia is recent and arose within the last 3my against a background of increased aridification or extreme climatic variability during the Pliocene. In the ingroup, diversity is highest in Southern Africa, followed by Tropical East Africa and other arid parts of Africa, the Arabian Peninsula and India. Many disjunctions are revealed and these are best explained by recent, long distance dispersal. In Africa, the diversity arises from the presence of many different lineages over

  13. Offsite environmental monitoring report: Radiation monitoring around United States nuclear test areas

    International Nuclear Information System (INIS)

    This report describes the Offsite Radiation Safety Program conducted during 1990 by the Environmental Protection Agency's (EPA's) Environmental Monitoring Systems Laboratory -- Las Vegas. This laboratory operates an environmental radiation monitoring program in the region surrounding the Nevada Test Site (NTS) and at former test sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. The surveillance program is designed to measure levels and trends of radioactivity, if present, in the environment surrounding testing areas to ascertain whether current radiation levels and associated doses to the general public are in compliance with existing radiation protection standards. The surveillance program additionally has the responsibility to take action to protect the health and well being of the public in the event of any accidental release of radioactive contaminants. Offsite levels of radiation and radioactivity are assessed by sampling milk, water, and air; by deploying thermoluminescent dosimeters (TLDs) and using pressurized ion chambers (PICs); and by biological monitoring of animals, food crops, and humans. Personnel with mobile monitoring equipment are placed in areas downwind from the test site prior to each nuclear weapons test to implement protective actions, provide immediate radiation monitoring, and obtain environmental samples rapidly after any occurrence of radioactivity release

  14. e+e- -> pi+pi-e+e-: a potential background for sigma(e+e- -> pi+pi-) measurement via radiative return method

    OpenAIRE

    Czyz, Henryk; Nowak, Elzbieta

    2003-01-01

    A Monte Carlo generator (EKHARA) has been constructed to simulate the reaction e+e- -> pi+pi-e+e- based on initial and final state emission of a e+e- pair from e+e- -> pi+pi- production diagram.A detailed study of the process, as a potential background for sigma(e+e- -> pi+pi-) measurement via radiative return method, is presented for phi- and B- factory energies.

  15. NCRP Program Area Committee 7: Radiation Education, Risk Communication, Outreach, and Policy.

    Science.gov (United States)

    Becker, S M; Locke, P A

    2016-02-01

    Recognizing the central importance of effective communication, education, and policy across all of the domains of radiation safety and radiation protection, the National Council on Radiation Protection and Measurements (NCRP) established a new committee in 2013. Program Area Committee 7 (PAC 7) was created to develop projects and provide guidance on "Radiation Education, Risk Communication, Outreach, and Policy." After identifying individuals with relevant expertise who were willing to serve, the Committee held its inaugural meeting in 2014. In 2015, the Committee increased its membership and began carrying out an expanded program of activities. One area of activity has involved providing input and feedback on risk communication issues to NCRP and other agencies. Another area of work has involved liaising with other NCRP committees (e.g., Council Committee 1 and PAC 3) to help incorporate psychosocial and risk communication issues into projects. Future efforts of NCRP's newest PAC are expected to include the development of authoritative reports and commentaries dealing with critical issues and challenges in radiation risk communication, education, and policy.

  16. NCRP Program Area Committee 7: Radiation Education, Risk Communication, Outreach, and Policy.

    Science.gov (United States)

    Becker, S M; Locke, P A

    2016-02-01

    Recognizing the central importance of effective communication, education, and policy across all of the domains of radiation safety and radiation protection, the National Council on Radiation Protection and Measurements (NCRP) established a new committee in 2013. Program Area Committee 7 (PAC 7) was created to develop projects and provide guidance on "Radiation Education, Risk Communication, Outreach, and Policy." After identifying individuals with relevant expertise who were willing to serve, the Committee held its inaugural meeting in 2014. In 2015, the Committee increased its membership and began carrying out an expanded program of activities. One area of activity has involved providing input and feedback on risk communication issues to NCRP and other agencies. Another area of work has involved liaising with other NCRP committees (e.g., Council Committee 1 and PAC 3) to help incorporate psychosocial and risk communication issues into projects. Future efforts of NCRP's newest PAC are expected to include the development of authoritative reports and commentaries dealing with critical issues and challenges in radiation risk communication, education, and policy. PMID:26717162

  17. Estimation of daily global solar radiation as a function of routine meteorological data in Mediterranean areas

    Science.gov (United States)

    Meza, Francisco Javier; Yebra, María Lorenzo

    2016-08-01

    Solar radiation is the main responsible of many processes of the biophysical environment. Temperature changes, snow melt dynamics, carbon sequestration, evaporation from soils, plants, and open water bodies are explained by the amount of radiation received in a surface. Lack of direct observations and insufficient record length limit the ability to use global solar radiation information for resource use management and planning. Based on the general equation of Bristow and Campbell, we propose a modification that allows us to better represent atmospheric transmissivity as a function of routine meteorological variables and improve estimates of global solar radiation in Mediterranean and semi arid areas. The improved Bristow-Campbell model (IBC) is easy to use in any location where measurements of temperature, precipitation, and relative humidity are available, and present a simple solution that can be used as proxy for relative humidity in case that variable is not been measured.

  18. Radiation dose distribution monitoring at neutron radiography facility area, Nuclear Energy Unit, Malaysia

    International Nuclear Information System (INIS)

    One experiment was carried out to get the distribution of radiation doses at the neutron radiography facilities, Nuclear Energy Unit, Malaysia. The analysis was done to evaluate the safety level of the area. The analysis was used in neutron radiography work

  19. Offsite environmental monitoring report. Radiation monitoring around United States nuclear test areas, calendar year 1982

    International Nuclear Information System (INIS)

    A principal activity of the Offsite Radiological Safety Program is routine environmental monitoring for radioactive materials in various media and for radiation in areas which may be affected by nuclear tests. It is conducted to document compliance with standards, to identify trends, and to provide information to the public. This report summarizes these activities for CY 1982

  20. Offsite environmental monitoring report. Radiation monitoring around United States nuclear test areas, calendar year 1982

    Energy Technology Data Exchange (ETDEWEB)

    Black, S. C.; Grossman, R. F.; Mullen, A. A.; Potter, G. D.; Smith, D. D. [comps.

    1983-07-01

    A principal activity of the Offsite Radiological Safety Program is routine environmental monitoring for radioactive materials in various media and for radiation in areas which may be affected by nuclear tests. It is conducted to document compliance with standards, to identify trends, and to provide information to the public. This report summarizes these activities for CY 1982.

  1. A microprocessor based area monitor system for neutron and gamma radiation

    International Nuclear Information System (INIS)

    The conventional electronics of the area monitors at the MPI-Heidelberg accelerators have been replaced by a microprocessor system consisting of individual detector-microprocessors and a central microcomputer. The detector microprocessors convert the count rates of BF3 and GM counter tubes into dose rates and control three different radiation thresholds (failure, low and high level). Different warning signals are operated directly by the detector processors, whereas the dose rates are transferred to the central microcomputer. Here the data are processed for recording on tape and displaying on TV monitors. The detector as well as the central processors have been developed on the basis of a 16-bit microprocessor. In the control rooms the dose rates of the individual monitors are displayed and on an indicator board showing the different locations, the high radiation level and the state of the doors (open, locked, and closed, locked but open) are sianaled by different LED. If a high radiation threshold is surpassed, the doors adjacent to that area can be locked either by switches on the indicator board or automatically. Within the experimental area, the low and high radiation level is indicated by acoustic and light signals. The whole concept permits keeping the absorbed doses of the personnel as low as possible without affecting the flexibility of the experimental operations. The independence of the microprocessor driven area monitors guarantees a high reliability. Compared to conventional electronics the advantages of the system are its reliability and cost. (Author)

  2. Influence factors of risk perception of radiation and its background. Questionnaire survey for reclamation project in the uranium mine

    International Nuclear Information System (INIS)

    To obtain public understanding on the uranium mining sites reclamation at Ningyo-toge Environmental Engineering Center, it is necessary to conduct appropriate Risk Communication (RC). In this study, to discuss the appropriate Risk communication method on the uranium mining sites reclamation, we conducted questionnaire survey and text analysis. The results of the text analysis are as follows: (1) The main elements of the concern of radiation are the uneasiness to oncogenesis or a health effect. (2) The trusts for technology or scientists are the main elements of the reliance for the standard of radiation, in the group which shows low-sense of ownership, hatred for radioactive ray has a strong impact relatively. (author)

  3. Extraction of Faces of More Than One Person From Natural Background Based on The Certainty Level Given to The Face Like Area

    Science.gov (United States)

    Ikeda, Misuzu; Ebine, Hideyuki; Nakamura, Osamu

    In general, it is very difficult to extract human faces from a natural background. In conventional methods, several conditions, such as the number of people included in a picture, the size of a face or the texture of the background are assumed. In this paper, the extracting method of faces from more than one person’s facial area with a natural background is presented, however, in the proposed method, such conditions described above are not supposed. In this system, a facial area is extracted using only the information of skin color at the first frame. After the second frame, the facial area is extracted based on the moving information of a face in addition to the color information. Computer simulation using 605 frames shows more than 85% extracting accuracy. From the experimental results, the prospects of using this method for the human face identification, image coding or the recognition of facial expressions are very encouraging.

  4. Impacts of Saharan dust and clouds on photosynthetically available radiation in the area off Northwest Africa

    Energy Technology Data Exchange (ETDEWEB)

    Ohde, Thomas; Siegel, Herbert [Leibniz Inst. for Baltic Sea Research, Warnemunde (Germany)], Email: thomas.ohde@io-warnemuende.de

    2012-01-15

    Radiation measurements in the area off Northwest Africa (research cruise, February 2008) and at Mindelo (Cape Verde Islands, May 2009) were used to investigate the impacts of Saharan dust and clouds on solar irradiance and on photosynthetically available radiation, to derive a relationship between dust aerosol optical depth (AOD) and photosynthetically available radiation and to determine the annual variations of photosynthetically available radiation. Three different kinds of atmospheric conditions were considered: cloudy skies, which decreased or increased the irradiance and dusty skies. The reduction by clouds was up to 67.2% at 400 nm and up to 84.4% at 700 nm. Enhancements of up to 21.9% at 400 nm and 34.0% at 700 nm were observed. The decrease by dust was up to 19.7% at 400 nm and up to 4.1% at 700 nm. Clouds decreased or increased the photosynthetically available radiation by up to 79.9% or up to 31.2%. The reduction by dust depended on the dust AOD and was between 3.6% and 12.3%. A linear relationship confirmed a decrease of photosynthetically available radiation of 1.2% by an increase of dust AOD of 0.1.

  5. Integration of radiation protection in safety management: sharing best practices between radiation protection and other safety areas

    International Nuclear Information System (INIS)

    Full text: The Institute for Reference Materials and Measurements (IRMM) located in Geel is one of the seven institutes of the Joint Research Centre of the European Commission (EC, DG JRC). The institute was founded in 1960 as a nuclear research centre, but has gradually shifted its activities to also include 'non-nuclear' domains, mainly in the areas of food safety and environmental surveillance. As the activities on the IRMM site are currently quite diversified, they necessitate the operation of nuclear controlled areas, accelerators, as well as bio safety restricted areas and chemical laboratories. Therefore, the care for occupational health and safety and for environmental protection has to take into consideration various types of hazards and threats. Recently an integrated management system according to ISO-9001, ISO-14001 and OHSAS-18001 was implemented. The integrated system combines 'vertically' quality, occupational health and safety and environmental issues and covers 'horizontally' the nuclear, biological and chemical fields. The paper outlines how the radiation protection can be included in an overall health, safety and environmental management system. It will give various practical examples where synergies can be applied: 1-) the overall policy; 2-) The assessment and ranking of all risks and the identification, in a combined way, of the appropriate prevention measures; 3-) The planning and review of related actions; 4-) The monitoring, auditing and registration of anomalies and incidents and the definition of corrective actions; 5-) The training of personnel based on lessons learned from past experiences; 6-) The organisation of an internal emergency plan dealing with nuclear and non-nuclear hazards. Based on these examples, the benefits of having an integrated approach are commented. In addition, the paper will illustrate how the recent ICRP fundamental recommendations and more particularly some of the principles of radiation protection such as

  6. Relationship between incident radiation, leaf area and dry-matter yield in wheat

    International Nuclear Information System (INIS)

    Light-utilization efficiency was evaluated between 20 and 50 days of crop growth period in 'Kalyansona', 'Sonalika' (semi-dwarf), 'Hindi 62' (tall) varieties of bread-wheat (Triticum aestivum Linn. emend., Fiori and Paol.) and semi-dwarf 'HD 4502' variety of macaroni wheat (T. durum Desf.). In the first model, the relationship between absorbed photosynthetic radiation and crop growth rates showed above-ground dry matter of 2.9 g in 'Sonalika', 2.5 g each in 'Kalyansona' and 'HD 4502' and 1.8 g in 'Hindi 62' were produced for each megajoule of absorbed photosynthetic radiation corresponding to the growth efficiency of 5.1, 4.4 and 3.1% respectively. In the second model of partial regression analysis, the rate of change in dry matter due to mean green area index as well as photosynthetic radiation was low in 'Hindi 62'. However, the dry matter changes due to mean green area index were similar in 'Kalyansona', 'HD4502' and 'Sonalika', but was high due to photosynthetic radiation in 'Sonalika' only. Both models gave similar conclusion

  7. Offsite environmental monitoring report: Radiation monitoring around United States nuclear test areas, calendar year 1997

    Energy Technology Data Exchange (ETDEWEB)

    Davis, M.G.; Flotard, R.D.; Fontana, C.A.; Hennessey, P.A.; Maunu, H.K.; Mouck, T.L.; Mullen, A.A.; Sells, M.D.

    1999-01-01

    This report describes the Offsite Radiological Environmental Monitoring Program (OREMP) conducted during 1997 by the US Environmental Protection Agency`s (EPAs), Radiation and Indoor Environments National Laboratory, Las Vegas, Nevada. This laboratory operated an environmental radiation monitoring program in the region surrounding the Nevada Test Site (NTS) and at former test sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. The surveillance program is designed to measure levels and trends of radioactivity, if present, in the environment surrounding testing areas to ascertain whether current radiation levels and associated doses to the general public are in compliance with existing radiation protection standards. The surveillance program additionally has the responsibility to take action to protect the health and well being of the public in the event of any accidental release of radioactive contaminants. Offsite levels of radiation and radioactivity are assessed by sampling and analyzing milk, water, and air; by deploying and reading thermoluminescent dosimeters (TLDs); and using pressurized ionization chambers (PICs) to measure ambient gamma exposure rates with a sensitivity capable of detecting low level exposures not detected by other monitoring methods.

  8. Offsite environmental monitoring report: Radiation monitoring around United States nuclear test areas, calendar year 1993

    International Nuclear Information System (INIS)

    This report describes the Offsite Radiation Safety Program conducted during 1993 by the Environmental Protection Agency's (EPA's) Environmental Monitoring Systems Laboratory - Las Vegas (EMSL-LV). This laboratory operates an environmental radiation monitoring program in the region surrounding the Nevada Test Site (NTS) and at former test sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. The surveillance program is designed to measure levels and trends of radioactivity, if present, in the environment surrounding testing areas to ascertain whether current radiation levels and associated doses to the general public are in compliance with existing radiation protection standards. The surveillance program additionally has the responsibility to take action to protect the health and well being of the public in the event of any accidental release of radioactive contaminants. Offsite levels of radiation and radioactivity are assessed by sampling milk, water, and air; by deploying thermoluminescent dosimeters (TLDs) and using pressurized ionization chambers (PICs); by biological monitoring of foodstuffs including animal tissues and food crops; and by measurement of radioactive material deposited in humans

  9. Offsite environmental monitoring report. Radiation monitoring around United States nuclear test areas, calendar year 1997

    International Nuclear Information System (INIS)

    This report describes the Offsite Radiological Environmental Monitoring Program (OREMP) conducted during 1997 by the US Environmental Protection Agency's (EPAs), Radiation and Indoor Environments National Laboratory, Las Vegas, Nevada. This laboratory operated an environmental radiation monitoring program in the region surrounding the Nevada Test Site (NTS) and at former test sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. The surveillance program is designed to measure levels and trends of radioactivity, if present, in the environment surrounding testing areas to ascertain whether current radiation levels and associated doses to the general public are in compliance with existing radiation protection standards. The surveillance program additionally has the responsibility to take action to protect the health and well being of the public in the event of any accidental release of radioactive contaminants. Offsite levels of radiation and radioactivity are assessed by sampling and analyzing milk, water, and air; by deploying and reading thermoluminescent dosimeters (TLDs); and using pressurized ionization chambers (PICs) to measure ambient gamma exposure rates with a sensitivity capable of detecting low level exposures not detected by other monitoring methods

  10. Offsite environmental monitoring report: Radiation monitoring around United States nuclear test areas, calendar year 1993

    Energy Technology Data Exchange (ETDEWEB)

    Chaloud, D.J; Daigler, D.M.; Davis, M.G. [and others

    1996-06-01

    This report describes the Offsite Radiation Safety Program conducted during 1993 by the Environmental Protection Agency`s (EPA`s) Environmental Monitoring Systems Laboratory - Las Vegas (EMSL-LV). This laboratory operates an environmental radiation monitoring program in the region surrounding the Nevada Test Site (NTS) and at former test sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. The surveillance program is designed to measure levels and trends of radioactivity, if present, in the environment surrounding testing areas to ascertain whether current radiation levels and associated doses to the general public are in compliance with existing radiation protection standards. The surveillance program additionally has the responsibility to take action to protect the health and well being of the public in the event of any accidental release of radioactive contaminants. Offsite levels of radiation and radioactivity are assessed by sampling milk, water, and air; by deploying thermoluminescent dosimeters (TLDs) and using pressurized ionization chambers (PICs); by biological monitoring of foodstuffs including animal tissues and food crops; and by measurement of radioactive material deposited in humans.

  11. Evaluation of the radiation field and shielding assessment of the experimental area of HIE-ISOLDE.

    Science.gov (United States)

    Romanets, Y; Bernardes, A P; Dorsival, A; Gonçalves, I F; Kadi, Y; di Maria, S; Vaz, P; Vlachoudis, V; Vollaire, J

    2014-10-01

    The ISOLDE facility at CERN is one of the first facilities in the world dedicated to the production of the radioactive ion beams (RIB) and during all its working time underwent several upgrades. The goal of the latest proposed upgrade, 'The High Intensity and Energy ISOLDE' (HIE-ISOLDE), is to provide a higher performance facility in order to approximate it to the level of the next generation ISOL facilities, like EURISOL. The HIE-ISOLDE aims to improve significantly the quality of the produced RIB and for this reason the increasing of the primary beam power is one of the main objectives of the project. An increase in the nominal beam current (from 2 to 6 μA proton beam intensity) and energy (from 1.4 GeV to 2 GeV) of the primary proton beam will be possible due to the upgrade of CERN's accelerator infrastructure. The current upgrade means reassessment of the radiation protection and the radiation safety of the facility. However, an evaluation of the existing shielding configuration and access restrictions to the experimental and supply areas must be carried out. Monte Carlo calculations were performed in order to evaluate the radiation protection of the facility as well as radiation shielding assessment and design. The FLUKA-Monte Carlo code was used in this study to calculate the ambient dose rate distribution and particle fluxes in the most important areas, such as the experimental hall of the facility. The results indicate a significant increase in the ambient dose equivalent rate in some areas of the experimental hall when an upgrade configuration of the primary proton beam is considered. Special attention is required for the shielding of the target area once it is the main and very intensive radiation source, especially under the upgrade conditions. In this study, the access points to the beam extraction and beam maintenance areas, such as the mass separator rooms and the high voltage room, are identified as the most sensitive for the experimental hall from

  12. Radiocarbon dating of archaeological samples (sambaqui) using CO(2) absorption and liquid scintillation spectrometry of low background radiation.

    Science.gov (United States)

    Mendonça, Maria Lúcia T G; Godoy, José M; da Cruz, Rosana P; Perez, Rhoneds A R

    2006-01-01

    Sambaqui means, in the Tupi language, a hill of shells. The sambaquis are archaeological sites with remains of pre-historical Brazilian occupation. Since the sambaqui sites in the Rio de Janeiro state region are older than 10,000 years, the applicability of CO(2) absorption on Carbo-sorb and (14)C determination by counting on a low background liquid scintillation counter was tested. In the present work, sambaqui shells were treated with H(3)PO(4) in a closed vessel in order to generate CO(2). The produced CO(2) was absorbed on Carbo-sorb. On saturation about 0.6g of carbon, as CO(2), was mixed with commercial liquid scintillation cocktail (Permafluor), and the (14)C activity determined by counting on a low background counter, Packard Tricarb 3170 TR/SL, for a period of 1000 mins to enable detection of a radiocarbon age of 22,400 BP. But only samples with ages up to 3500 BP were submitted to the method because the samples had been collected in the municipality of Guapimirim, in archaeological sambaqui-type sites belonging to this age range. The same samples were sent to the (14)C Laboratory of the Centro de Energia Nuclear na Agricultura (CENA/USP) where similar results were obtained.

  13. Limits on the Radiative Decay of Sterile Neutrino Dark Matter from the Unresolved Cosmic and Soft X-ray Backgrounds

    CERN Document Server

    Abazajian, Kevork N; Koushiappas, S M; Hickox, R C; Abazajian, Kevork N.; Markevitch, Maxim; Koushiappas, Savvas M.; Hickox, Ryan C.

    2006-01-01

    We present upper limits on line emission in the Cosmic X-ray background (CXB) that would be produced by decay of sterile neutrino dark matter. We employ the spectra of the unresolved component of the CXB in the Chandra Deep Fields North and South obtained with the Chandra CCD detector in the E=0.8-9 keV band. The expected decay flux comes from the dark matter on the lines of sight through the Milky Way galactic halo. Our constraints on the sterile neutrino decay rate are sensitive to the modeling of the Milky Way halo. The highest halo mass estimates provide a limit on the sterile neutrino mass of m_s<2.9 keV in the Dodelson-Widrow production model, while the lowest halo mass estimates provide the conservative limit of m_s<5.7 keV (2-sigma). We also discuss constraints from a short observation of the softer (E<1 keV) X-ray background with a rocket-borne calorimeter by McCammon and collaborators.

  14. High-resolution texture imaging with hard synchrotron radiation in the moving area detector technique

    CERN Document Server

    Wcislak, L; Klein, H; Garbe, U; Schneider, J R

    2003-01-01

    The orientation distribution of crystallites in polycrystalline materials (called texture) is usually measured by polycrystal X-ray diffraction by 'step-scanning' the sample in angular intervals in the order of 1 deg. This technique is not suited to fully exploit the low angular divergence of hard synchrotron radiation in the order of 'milliradian'. Hence, step-scanning was replaced by a continuous 'sweeping' technique using a continuously shifted area detector. In order to avoid overlapping from different reflections (hkl) a Bragg-angle slit was introduced. The 'moving-detector' technique can be applied to obtain images of orientation as well as of location distributions of crystallites in polycrystalline samples. It is suitable for imaging continuous 'orientation density' distribution functions as well as of 'grain-resolved' textures. The excellent features of high-energy synchrotron radiation combined with the moving area detector technique will be illustrated with several examples including very sharp def...

  15. Radiation shielding tests in the Meson beamline in the master substation area

    International Nuclear Information System (INIS)

    A review of shielding uncovered a weak region in a portion of the proton beam transport to the Meson Area. Preliminary CASIM Monte Carlo studies indicated dose rates at the surface under abnormal operating conditions would be above the Fermilab Radiation Guide limits. Measurements made on December 15 and 16 confirmed this concern. Further comparisons of data with CASIM predictions are discussed. 5 refs., 22 figs., 8 tabs

  16. Indoor and Outdoor in Situ High-Resolution Gamma Radiation Measurements in Urban Areas of Cyprus

    OpenAIRE

    E. Svoukis; Tsertos, H.

    2006-01-01

    In situ, high-resolution, gamma-ray spectrometry of a total number of 70 outdoor and 20 indoor representative measurements were performed in preselected, common locations of the main urban areas of Cyprus. Specific activities and gamma absorbed dose rates in air due to the naturally occurring radionuclides of Th-232 and U-238 series, and K-40 are determined and discussed. Effective dose rate to the Cyprus population due to terrestrial gamma radiation is derived directly from this work. The re...

  17. Radiation shielding calculations for MuCool Test Area at Fermilab

    CERN Document Server

    Rakhno, I

    2004-01-01

    The MuCool Test Area (MTA) is an intense primary beam facility derived directly from the Fermilab Linac to test heat deposition and other technical concerns associated with the liquid hydrogen targets being developed for cooling intense muon beams. In this shielding study the results of Monte Carlo radiation shielding calculations performed using the MARS14 code for the MuCool Test Area and including the downstream portion of the target hall and berm around it, access pit, service building, and parking lot are presented and discussed within the context of the proposed MTA experimental configuration.

  18. Radiation shielding calculations for MuCool test area at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Igor Rakhno; Carol Johnstone

    2004-05-26

    The MuCool Test Area (MTA) is an intense primary beam facility derived directly from the Fermilab Linac to test heat deposition and other technical concerns associated with the liquid hydrogen targets being developed for cooling intense muon beams. In this shielding study the results of Monte Carlo radiation shielding calculations performed using the MARS14 code for the MuCool Test Area and including the downstream portion of the target hall and berm around it, access pit, service building, and parking lot are presented and discussed within the context of the proposed MTA experimental configuration.

  19. Limits on the radiative decay of sterile neutrino dark matter from the unresolved cosmic and soft x-ray backgrounds

    Science.gov (United States)

    Abazajian, Kevork N.; Markevitch, Maxim; Koushiappas, Savvas M.; Hickox, Ryan C.

    2007-03-01

    We present upper limits on line emission in the Cosmic X-ray background (CXB) that would be produced by decay of sterile neutrino dark matter. We employ the spectra of the unresolved component of the CXB in the Chandra Deep Fields North and South obtained with the Chandra CCD detector in the E=0.8 9keV band. The expected decay flux comes from the dark matter on the lines of sight through the Milky Way galactic halo. Our constraints on the sterile neutrino decay rate are sensitive to the modeling of the Milky Way halo. The highest halo mass estimates provide a limit on the sterile neutrino mass of mscalorimeter by McCammon and collaborators.

  20. Photonic Integrated Circuit (PIC) Device Structures: Background, Fabrication Ecosystem, Relevance to Space Systems Applications, and Discussion of Related Radiation Effects

    Science.gov (United States)

    Alt, Shannon

    2016-01-01

    Electronic integrated circuits are considered one of the most significant technological advances of the 20th century, with demonstrated impact in their ability to incorporate successively higher numbers transistors and construct electronic devices onto a single CMOS chip. Photonic integrated circuits (PICs) exist as the optical analog to integrated circuits; however, in place of transistors, PICs consist of numerous scaled optical components, including such "building-block" structures as waveguides, MMIs, lasers, and optical ring resonators. The ability to construct electronic and photonic components on a single microsystems platform offers transformative potential for the development of technologies in fields including communications, biomedical device development, autonomous navigation, and chemical and atmospheric sensing. Developing on-chip systems that provide new avenues for integration and replacement of bulk optical and electro-optic components also reduces size, weight, power and cost (SWaP-C) limitations, which are important in the selection of instrumentation for specific flight projects. The number of applications currently emerging for complex photonics systems-particularly in data communications-warrants additional investigations when considering reliability for space systems development. This Body of Knowledge document seeks to provide an overview of existing integrated photonics architectures; the current state of design, development, and fabrication ecosystems in the United States and Europe; and potential space applications, with emphasis given to associated radiation effects and reliability.

  1. Background concentrations of heavy metals in aquatic bryophytes used for biomonitoring in basaltic areas (a case study from central France)

    Energy Technology Data Exchange (ETDEWEB)

    Samecka-Cymerman, A. [Wroclaw Univ. (Poland). Dept. of Ecology and Nature Protection; Kempers, A.J. [Nijmegen Univ. (Netherlands). Dept. of Aquatic Ecology and Biogeology

    1999-12-01

    Studies were made of the aquatic bryophytes Fontinalis antipyretica Hedw., Plathypnidium rusciforme (Neck.)Fleisch and Chiloscyphus sp. (Hoffm.)Dum. from streams embedded in basaltic rocks (Le Puy, central France). Water from these streams possessed elevated levels of Cu, Zn, Sr, V, Ba, Ni and Co, reflecting the geochemistry of the basalts, a basic type of igneous rocks containing elevated levels of these elements. The concentration of elements in bryophytes is correlated to the chemical composition of water of their sampling sites. Contents of trace elements in plants were higher than background values. The elevated levels of these elements possibly caused disturbances in the ionic equilibrium within the bryophytes. The molar ratio between contents of Ca and Mg in water (from 0.44 to 1) was different from that typical for natural water. (orig.)

  2. Transfer factor of the radionuclides in food crops from high-background radiation area of south west India.

    Science.gov (United States)

    Shanthi, G; Thanka Kumaran, J Thampi; Gnana Raj, G Allen; Maniyan, C G

    2012-04-01

    It is necessary to obtain the transfer factor (TF) of long-lived radionuclides because soil type and vegetation can affect TF. We studied the food crops commonly consumed by the general public of Kanyakumari district of south India. The main focus was on rice, fruits, vegetables and tapioca because the consumption of these is high. The soil to rice TF for the radionuclides, (226)Ra, (232)Th, (238)U and (40) K are 8.8×10(-2), 14.2×10(-2), 5.8×10(-2) and 6.3×10(-2), respectively. The TF of tapioca for (226)Ra, (232)Th, (238)U and (40) K are 6.2×10(-2) , 11×10(-2), 1.9×10(-2) and 8.9×10(-2), respectively. For fruits and vegetables, the TFs are low. In the majority of the crops the non-edible parts accumulate more radionuclides than the edible parts. PMID:21680604

  3. Assessment of indoor radiation level in the environs of the uranium deposit area of West Khasi Hills District, Meghalaya, India

    Energy Technology Data Exchange (ETDEWEB)

    War, S.A. [Department of Physics, North Eastern Hill University, Shillong - 793 022, Meghalaya (India)], E-mail: aaron2416@yahoo.com; Nongkynrih, P.; Khathing, D.T. [Department of Physics, North Eastern Hill University, Shillong - 793 022, Meghalaya (India); Iongwai, P.S. [Department of Zoology, North Eastern Hill University, Shillong - 793 022, Meghalaya (India)

    2009-11-15

    An estimation of the indoor background radiation dose distribution was carried out in dwellings of eleven villages located within and around the uranium mineralization area of Kylleng-Pyndensohiong, Mawthabah in West Khasi Hills District of Meghalaya, India. The ambient indoor gamma radiation level was monitored using Thermo Luminescence Dosimeters (TLDs) while the indoor radon and thoron concentration was measured using twin-cup dosimeters employing Solid State Nuclear Track Detectors (SSNTDs). Results obtained from the study reveals that the local inhabitants of villages located close to the mining site receive higher doses than those inhabitants of villages located at a much farther distance from the mining site. The average total annual effective dose was found to be varying from 1.2 mSv y{sup -1} in the village of Langpa to 3.4 mSv y{sup -1} in the village of Nongbah Jynrin. The data obtained will serve as a reference in documenting changes to environmental radioactivity if mining is to be carried out in the future.

  4. Theoretical analysis of the background intensity distribution in X-ray Birefringence Imaging using synchrotron bending-magnet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sutter, John P., E-mail: john.sutter@diamond.ac.uk; Dolbnya, Igor P.; Collins, Stephen P. [Diamond Light Source Ltd., Chilton, Didcot, Oxfordshire OX11 0DE (United Kingdom); Harris, Kenneth D. M.; Edwards-Gau, Gregory R. [School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT, Wales (United Kingdom); Palmer, Benjamin A. [Department of Structural Biology, Weizmann Institute of Science, 234 Herzl St., Rehovot 7610001 (Israel)

    2015-04-28

    In the recently developed technique of X-ray Birefringence Imaging, molecular orientational order in anisotropic materials is studied by exploiting the birefringence of linearly polarized X-rays with energy close to an absorption edge of an element in the material. In the experimental setup, a vertically deflecting high-resolution double-crystal monochromator is used upstream from the sample to select the appropriate photon energy, and a horizontally deflecting X-ray polarization analyzer, consisting of a perfect single crystal with a Bragg reflection at Bragg angle of approximately 45°, is placed downstream from the sample to measure the resulting rotation of the X-ray polarization. However, if the experiment is performed on a synchrotron bending-magnet beamline, then the elliptical polarization of the X-rays out of the electron orbit plane affects the shape of the output beam. Also, because the monochromator introduces a correlation between vertical position and photon energy to the X-ray beam, the polarization analyzer does not select the entire beam, but instead selects a diagonal stripe, the slope of which depends on the Bragg angles of the monochromator and the polarization analyzer. In the present work, the final background intensity distribution is calculated analytically because the phase space sampling methods normally used in ray traces are too inefficient for this setup. X-ray Birefringence Imaging data measured at the Diamond Light Source beamline B16 agree well with the theory developed here.

  5. Analysis of characteristics and radiation safety situation of uranium mining and metallurgy facilities in north area of China

    International Nuclear Information System (INIS)

    According to the radiation safety management of uranium mining and metallurgy facilities in north area of China, features and radiation safety conditions of uranium mining and metallurgy facilities in north area of China were analyzed based on summarizing the inspection data for 2011-2013. So the main problems of radiation environment security on uranium mine were studied. The relevant management measures and recommendations were put forward, and the basis for environmental radiation safety management decision making of uranium mining and metallurgy facilities in future was provided. (authors)

  6. Application of radiation protection principles to the cleanup of contaminated areas. Interim report for comment

    International Nuclear Information System (INIS)

    Recognizing that there was a general lack of guidance on protection from ionizing radiation in the case of protracted or chronic exposures and prompted by the clear need for such guidance for aiding decision making in the particular case of the rehabilitation of areas affected by residual deposits of radioactive materials from past activities, the IAEA started a project in 1993 to address the problem. A small working group was established and met on several occasions over a three year period. The working group used, as it starting point, the Recommendations of the International Commission of Radiological Protection (ICRP) (Publication 60) and the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources. The approach emphasizes the use of risk to individuals from existing contamination and from the residual contamination after cleanup actions as a basis for decision making. Nevertheless, links are maintained with the basic ICRP radiation protection system by recognizing that, in many situations, cleanup actions may be influenced by more than only individual risk consideration; there will be radiological and non-radiological constraints which will differ depending on whether the situation is more 'intervention like' or 'practice like'. The framework for decision making being proposed by the working group is being published in this report to allow for a period of review and comment by experts and decision makers in Member States

  7. Studies on geological background and source of fluorine in drinking water in the North China Plate fluorosis areas

    Science.gov (United States)

    Luo, K.; Feng, F.; Li, H.; Chou, C.-L.; Feng, Z.; Yunshe, D.

    2008-01-01

    Endemic fluorosis in northern China is usually produced by high fluorine (F) content in drinking water. Thirty-one samples of drinking waters, mainly well waters and nearly 200 samples of rocks, loess, and coal were analyzed for F content using the combustion hydrolysis-fluoride-ion selective electrode (ISE) method. The geologic cross sections of two well-known fluorosis basins were studied. The solubility of F in different rock types collected from fluorosis areas was determined. Results showed that areas of endemic fluorosis in northern China are located in coal-bearing basins which are comprised of three stratagraphic portions. The lowest portion is Precambrian granitic rocks or Cambrian-Ordovician carbonates. The middle portion consists of Permo-Carboniferous or Jurassic coal-bearing sequences. The upper portion is 0-400 m Pleistocene loess. Flourine content in the Precambrian granite-gneiss contained (a) 1090-1460 ppm, in the Cambrian-Ordovician limestone and dolomite, (b) 52-133 ppm, in black shales and coal gob of Permo-Carboniferous coal-bearing strata, (c) 200-700 ppm, and (d) Pleistocene loess 454-542 ppm. The solubility of F in black shales of coal-bearing sequences was higher than in Precambrian granitic rocks, and both were more soluble than loess. F solubility from Precambrian granitic rocks was moderate, but Precambrian granitic rocks have high F content and thus contribute an appreciable amount of ion to the shallow groundwater (well water). Varying F content in shallow groundwater is controlled by geological conditions. The sources of F in the shallow groundwater from fluorosis areas in northern China are mainly derived from black shales of coal-bearing sequences and Precambrian granitic basement in the basins of northern China. ?? 2008 Taylor & Francis.

  8. Application of low background γ-ray spectrometry to seaweed. Behaviors and distributions of natural radionuclides in Noto coastal area

    International Nuclear Information System (INIS)

    In order to investigate the behaviors of radionuclides in the coastal area, 68 seaweed (Sargasso) and 27 coastal waters samples were collected at four sites of Shika (r 234Th/238U > ∼10); 2) 228Ra/226Ra activity ratios of Sargasso samples show the seasonal variation with minimum values (228Ra/226Ra = ∼1.2) in Jun. and maximum (2.5 - 3.5) in Dec., which is similar to that of the surrounding water; and 3) even in this small region, the regional difference was observed in 210Pb (and 7Be) activities. (author)

  9. Population exposure to airborne thorium at the high natural radiation areas in India

    International Nuclear Information System (INIS)

    High natural radiation areas in the coastal and peninsular India were studied for airborne thorium and resultant population exposure due to inhalation. Four locations covering three states viz., Ayiramthengu and Neendakara in Kerala, Kudiraimozhi in Tamil Nadu and Bhimilipatnam in Andhra Pradesh were investigated. External gamma radiation fields 1 m above the monazite ore bodies ranged from 200 to 3000 nGy h-1. Soil samples showed 232Th specific activity varying from 0·1 to 1·5 Bq g-1 with surface alpha activity in the range of 1·0-12·5 Bq cm-2. Suspended particulates in the samples ranged from 60-140 μg m-3 with 232Th showing a wider variation of -3. There was poor correlation between suspended particulates and long-lived alpha airborne activity (r=-0·3). The resuspension factors for 232Th were in the range of 1·5x10-8-7·9x10-7 cm-1. Higher resuspension was correlated with dry sand dunes. The upper limits for Committed Effective Dose (CED) due to inhalation of airborne 232Th at the respective high natural radiation areas were estimated to range from 50±30 to 300±130 μSv (5-30 mrem) per year per adult member of public assuming an activity median aerodynamic diameter of 1 μm for the airborne particulates. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  10. Surface ozone concentrations and solar radiation in polluted and remote areas in Egypt

    International Nuclear Information System (INIS)

    this work discusses sources of ozone in the troposphere, particularly with regard to the relative contributions of flues from the stratosphere and that created due to photochemical reactions in the troposphere. Measurements of surface ozone at cairo and the oases Dakhla are used as a a comparative study between the formation of ozone in a polluted area and that of clean atmosphere. The daily maximum ozone concentrations found to be 105 ppb in cairo and 52 ppb in Dakhla. The results show that the budget of ozone in the polluted air masses is dominated by photochemistry, and there is a significant correlation between the monthly mean value use of ozone and global radiation. The ozone budget in free troposphere and rural areas, where the diurnal variation is very low compared to that of polluted areas, is governed by vertical transport

  11. Deep Background of Wenchuan Earthquake and the Upper Crust Structure beneath the Longmen Shan and Adjacent Areas

    Institute of Scientific and Technical Information of China (English)

    LI Qiusheng; GAO Rui; WANG Haiyan; ZHANG Jisheng; LU Zhanwu; LI Pengwu; GUAN Ye; HE Rizheng

    2009-01-01

    By analyzing the deep seismic sounding profiles across the Longmen Shan, this paper focuses on the study of the relationship between the upper crust structure of the Longmen Shan area and the Wenchuan earthquake. The Longmen Shan thrust belt marks not only the topographical change, but also the lateral velocity variation between the eastern Tibetan Plateau and the Sichuan Basin. A low-velocity layer has consistently been found in the crust beneath the eastern edge of the Tibetan Plateau, and ends beneath the western Sichuan Basin. The low-velocity layer at a depth of -20 km beneath the eastern edge of the Tibetan Plateau has been considered as the deep condition for favoring energy accumulation that formed the great Wenchuan earthquake.

  12. Influence of high-fluorine environmental background on crops and human health in hot spring-type fluorosis-diseased areas

    Institute of Scientific and Technical Information of China (English)

    LAN De; WU Daishe; LI Ping; WANG Tengsheng; CHEN Chengguang; WANG Wuyi

    2008-01-01

    Drinking water-type fluorosis is the most harmful endemic disease in China with the largest number of sufferers. Although the implementation of the policy to alter water sources to lower fluoride level has effectively controlled the spread of this kind of endemic disease, its prevalence could not thoroughly be stopped because the high-fluoride environmental background in these endemically diseased areas could still do harm to human health through food chain. Therefore, it is necessary to conduct a more deep-going study on the drinking water-type fluorosis. To investigate the effect of high fluorine environmental background on crops and human health in the hot spring-type fluorosis-diseased areas, local water, paddy soil, rice, whole vegetables and soils around their roots were sampled for analysis. The results were compared with those of the control groups in fluorosis-free areas which are similar to the fluorosis-diseased areas both in natural background and in social background. It is indicated that rice and vegetables can accumulate water-soluble fluorine either in soils or in irrigating water, and different crops have different abilities of fixing fluorine. The contents of fluorine in different parts of vegetables in the fluorosis-diseased and fluorosis-free areas were statistically categorized. The results showed that the fluorine contents of roots, tubers, leaves and flowers of vegetables in the fluorosis-diseased areas are 3.56, 1.17, 3.07 and 3.23 mg/kg, respectively. However, comparisons showed that in the fluorosis-free areas, the fluorine contents are 2.17, 0.70, 1.91 and 2.52 mg/kg, respectively. Moreover, different parts of a crop also show significantly different fluorine fixation abilities. It is demonstrated that the fluorine contents of the strongly metabolic parts are relatively high. For example, the fluorine contents of roots, leaves and flowers of vegetables are much higher than those of stems. The fluorine fixation ability of seeds is very

  13. SPATIAL DIFFERENTIATION OF GLOBAL SOLAR RADIATION IN TORUŃ AND ITS SUBURBAN AREA (CENTRAL POLAND) IN 2012

    OpenAIRE

    Kejna, Marek; Uscka-Kowalkowska, Joanna; Araźny, Andrzej; Kunz, Mieczysław; Maszewski, Rafał; Przybylak, Rajmund

    2015-01-01

    This article investigates the spatial distribution of global solar radiation (K↓) in Toruń and its suburbs, observed in 2012. Measurements were taken at 12 points (7 within the city and 5 in the suburban area) using CNR4 net radiometers and automatic weather stations (Vantage Pro+). At all locations, the diurnal and annual courses of K↓ were typically related to the Earth’s rotational movement and changes in the sun’s declination over the year, and disturbed by clouds and atmospheric phenomen...

  14. Independent regulatory examination of radiation situation in the areas of spent nuclear fuel and radioactive wastes storage in the Russian far east

    International Nuclear Information System (INIS)

    This paper describes the findings of the radiation situation analysis on-site near Sysoeva and Razbojnik Bays. The results of radiation monitoring performed by radiological laboratory of DalRAO and studies performed by the experts from the Burnasyan Federal Medical Biophysical Centre have been used in the course of analysis. On the industrial sites, gamma dose rate reaches 60 μSv h-1, and the specific activities of man-made radionuclides in soil reach 2.5ix104 Bq kg-1 for 137Cs, 7.6ix103 Bq kg-1 for 90Sr and 2.0x103 Bq kg-1 for 60Co. Beyond the industrial sites, there are three local parts of the area on the coast and in the off-shore water area, contaminated with man-made radionuclides. Gamma dose rate reaches 8 μSv h-1. The radionuclide contents in soil at this area reach 3.6x103, 2.8x103 and 19 Bq kg-1 for 137Cs, 90Sr and 60Co, respectively. At the remaining part of the area nearby Sysoeva Bay, the radiation situation complies with natural background. (authors)

  15. Independent regulatory examination of radiation situation in the areas of spent nuclear fuel and radioactive wastes storage in the Russian far east.

    Science.gov (United States)

    Shandala, N K; Kiselev, S M; Lucyanec, A I; Titov, A V; Seregin, V A; Isaev, D V; Akhromeev, S V

    2011-07-01

    This paper describes the findings of the radiation situation analysis on-site near Sysoeva and Razbojnik Bays. The results of radiation monitoring performed by radiological laboratory of DalRAO and studies performed by the experts from the Burnasyan Federal Medical Biophysical Centre have been used in the course of analysis. On the industrial sites, gamma dose rate reaches 60 µSv h(-1), and the specific activities of man-made radionuclides in soil reach 2.5 × 10(4) Bq kg(-1) for (137)Cs, 7.6 × 10(3) Bq kg(-1) for (90)Sr and 2.0 × 10(3) Bq kg(-1) for (60)Co. Beyond the industrial sites, there are three local parts of the area on the coast and in the off-shore water area, contaminated with man-made radionuclides. Gamma dose rate reaches 8 µSv h(-1). The radionuclide contents in soil at this area reach 3.6 × 10(3), 2.8 × 10(3) and 19 Bq kg(-1) for (137)Сs, (90)Sr and (60)Со, respectively. At the remaining part of the area nearby Sysoeva Bay, the radiation situation complies with natural background. PMID:21493600

  16. Comment on "Stress induction in the bacteria Shewanella oneidensis and Deinococcus radiodurans in response to below-background ionizing radiation", Castillo, et al. Int. J. Rad. Biol., 2015; Early Online DOI:10.3109/09553002.2015.1062571

    CERN Document Server

    Katz, J I

    2015-01-01

    Castillo, et al. report hormesis by background levels of radiation, at which there is $< 10^{-3}$ ionization per bacterium in a replication time. This suggests radiation products accumulate in the growth medium over much longer times. Experiments are proposed to test this hypothesis.

  17. A map of the cosmic microwave background radiation from the Wilkinson Microwave Anisotropy Probe (WMAP), showing the large-scale fluctuations (the quadrupole and octopole) isolated by an analysis done partly by theorists at CERN.

    CERN Multimedia

    2004-01-01

    A recent analysis, in part by theorists working at CERN, suggests a new view of the cosmic microwave background radiation. It seems the solar system, rather than the universe, causes the radiation's large-scale fluctuations, similar to the bass in a song.

  18. The BOOMERANG North America Instrument a balloon-borne bolometric radiometer optimized for measurements of cosmic background radiation anisotropies from 0.3 to 4 degrees

    CERN Document Server

    Piacentini, F; Bathia, R; Bock, J J; Boscaleri, A; Cardoni, P; Crill, B P; De Bernardis, P; Castillo, H D; De Troia, G; Farese, P; Giacometti, M; Hivon, E F; Hristov, V V; Iacoangeli, A; Lange, A E; Masi, S; Mauskopf, P D; Miglio, L; Netterfield, C B; Palangio, P; Pascale, E; Raccanelli, A; Rao, S; Romeo, G; Ruhl, J E; Scaramuzzi, F

    2001-01-01

    We describe the BOOMERANG North America (BNA) instrument, a balloon-borne bolometric radiometer designed to map the Cosmic Microwave Background (CMB) radiation with 0.3 deg resolution over a significant portion of the sky. This receiver employs new technologies in bolometers, readout electronics, millimeter-wave optics and filters, cryogenics, scan and attitude reconstruction. All these subsystems are described in detail in this paper. The system has been fully calibrated in flight using a variety of techniques which are described and compared. It has been able to obtain a measurement of the first peak in the CMB angular power spectrum in a single balloon flight, few hours long, and was a prototype of the BOOMERANG Long Duration Balloon (BLDB) experiment.

  19. Determination of environmental radioactivity (238U, 232Th and 40K) and indoor natural background radiation level in Chennai city (Tamilnadu State), India.

    Science.gov (United States)

    Babai, K S; Poongothai, S; Punniyakotti, J

    2013-01-01

    An extensive study on the determination of the natural radioactivity ((238)U, (232)Th and (40)K) levels in soil samples of Chennai city, India has been undertaken and the results of the same are compared with the levels reported in other Indian cities as well as other parts of the world. The radioactivity content in the soil samples, the absorbed dose rate, annual effective dose equivalent, radium equivalent activity, internal and external hazard indices were calculated and compared with UNSCEAR 2000 recommended values. In addition to the above, mapping of indoor natural background gamma radiation levels has been made using thermo luminescent dosemeters throughout Chennai city and the same are reported. PMID:22847868

  20. NOAA Climate Data Record (CDR) of Leaf Area Index (LAI) and Fraction of Absorbed Photosynthetically Active Radiation (FAPAR), Version 4

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains gridded daily Leaf Area Index (LAI) and Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) derived from the NOAA Climate Data...

  1. Uncooled Radiation Hard Large Area SiC X-ray and EUV Detectors and 2D Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project seeks to design, fabricate, characterize and commercialize large area, uncooled and radiative hard 4H-SiC EUV ? soft X-ray detectors capable of ultra...

  2. The twenty-second screening for thyroid disorders in radiation-contaminated areas of the Ukraine

    Energy Technology Data Exchange (ETDEWEB)

    Harada, Tanekazu [Kawasaki Coll. of Allied Health Professions, Kurashiki, Okayama (Japan); Monobe, Manami

    2000-12-01

    One hundred and ninety-one people who reside in radiation-contaminated areas of the Ukraine near the site of the Chernobyl nuclear plant accident were screened in 1999. The ages of people screened ranged from 1 to 74 years. Diffuse goiter was palpable in 67.5%, and nodular goiter in 3.1%. Thyroid cancer was detected in only one suspicious case. Among the people with diffuse goiter, however, there were positive anti-thyroglobulin hemagglutination tests (TGHA) in 6.7% and positive anti-microsome hemagglutination tests (MCHA) in 16.7% of cases. In addition, urinary iodine concentrations and daily urinary excretion were low. Thus, it is thought that the majority of diffuse goiters in this area are not due to autoimmune thyroiditis but to iodine deficiency. At present, no definite conclusion can be drawn on the relationship between the large number of diffuse goiters and radioactive contamination. Further studies are required. (author)

  3. Indoor and outdoor in situ high-resolution gamma radiation measurements in urban areas of Cyprus.

    Science.gov (United States)

    Svoukis, E; Tsertos, H

    2007-01-01

    In situ, high-resolution, gamma-ray spectrometry of a total number of 70 outdoor and 20 indoor representative measurements were performed in preselected, common locations of the main urban areas of Cyprus. Specific activities and gamma absorbed dose rates in air due to the naturally occurring radionuclides of (232)Th and (238)U series, and (40)K are determined and discussed. Effective dose rate to the Cyprus population due to terrestrial gamma radiation is derived directly from this work. The results obtained outdoors match very well with those derived previously by high-resolution gamma spectrometry of soil samples, which were collected from the main island bedrock surface. This implies that the construction and building materials in urban areas do not affect the external gamma dose rate; thus they are mostly of local origin. Finally, the indoor/outdoor gamma dose ratio was found to be 1.4 +/- 0.5. PMID:17065195

  4. Indoor and Outdoor in Situ High-Resolution Gamma Radiation Measurements in Urban Areas of Cyprus

    CERN Document Server

    Svoukis, E

    2006-01-01

    In situ, high-resolution, gamma-ray spectrometry of a total number of 70 outdoor and 20 indoor representative measurements were performed in preselected, common locations of the main urban areas of Cyprus. Specific activities and gamma absorbed dose rates in air due to the naturally occurring radionuclides of Th-232 and U-238 series, and K-40 are determined and discussed. Effective dose rate to the Cyprus population due to terrestrial gamma radiation is derived directly from this work. The results obtained outdoors match very well with those derived previously by high-resolution gamma spectrometry of soil samples, which were collected from the main island bedrock surface. This implies that the construction and building materials in urban areas do not affect the external gamma dose rate; thus they are mostly of local origin. Finally, the indoor/outdoor gamma dose ratio was found to be 1.4 +- 0.5.

  5. The Variations and Trends of MODIS C5 & C6 Products’ Errors in the Recent Decade over the Background and Urban Areas of North China

    Directory of Open Access Journals (Sweden)

    Qi Zhang

    2016-09-01

    Full Text Available With ten-year (2004–2013 ground-based observations of Beijing Forest (BJF and Beijing City (BJC sites in North China, we validated the high-quality MODerate resolution Imaging Spectroradiometer (MODIS Collection 5 (C5 and Collection 6 (C6 Aerosol Optical Depth (AOD products’ precision and discussed the sensors degradation issues. The annual mean AOD and Angstrom exponent (α were 0.20 ± 0.02 and 0.83 ± 0.15 in the background over the past ten years, and they were 0.59 ± 0.07 and 1.13 ± 0.08 in the urban, respectively. Ground-based AOD had both slightly declining trends, with variations of 0.023 and 0.057 over the past decade in the background and urban, respectively. There were large differences among the eight kinds of MODIS AOD products (Terra vs. Aqua, C5 vs. C6, DT (Deep Target vs. DB (Deep Blue, and DTDB in the background and urban areas, but all the products’ monthly errors had larger variations in the spring and summer, and smaller ones in the autumn and winter. In the background, more than 62% of DT matchups for C5 and C6 products were within NASA’s expected error (EE envelope. In the urban, 69%~72% of C6 DB retrievals were falling within EE envelope. The new dataset named C6 DTDB had better performance in the background, whereas it overestimated by 37%~41% in the urban caused by surface reflectivity estimation error. The range of monthly average error varied from −0.21 to 0.28 in the background and from −0.63 to 0.48 in the urban. From the background to the urban areas, the retrieval errors of Terra and Aqua had slightly increased by 0.0023~0.0158 and 0.0011~0.0124 per year, respectively, which implied that the two MODIS instruments had degraded slowly.

  6. RADIATION HYGIENIC MONITORING AND ASSESSMENT OF POPULATION DOSES IN RADIOACTIVELY CONTAMINATED AREAS OF TULA REGION

    Directory of Open Access Journals (Sweden)

    T. M. Chichura

    2016-01-01

    Full Text Available The goal. The analyses of radiation hygienic monitoring conducted in Tula region territories affected by the Chernobyl NPP accident regarding cesium-137 and strontium- 90 in the local foodstuffs and the analyses of populational annual effective dose. The materials and methods. The survey was conducted in Tula Region since 1997 to 2015. Over that period, more than fifty thousand samples of the main foodstuffs from the post-Chernobyl contaminated area were analyzed. Simultaneously with that, the external gamma - radiation dose rate was measured in the fixed control points. The dynamics of cesium -137 and strontium-90 content in foodstuffs were assessed along with the maximum values of the mean annual effective doses to the population and the contribution of the collective dose from medical exposures into the structure of the annual effective collective dose to the population. The results. The amount of cesium-137 and strontium -90 in the local foodstuffs was identified. The external gamma- radiation dose rate values were found to be stable and not exceeding the natural fluctuations range typical for the middle latitudes of Russia’s European territory. The maximum mean annual effective dose to the population reflects the stable radiation situation and does not exceed the permissible value of 1 mSv. The contribution of the collective dose from medical exposures of the population has been continuously reducing as well as the average individual dose to the population per one medical treatment under the annual increase of the medical treatments quantities. The conclusion. There is no exceedance of the admissible levels of cesium-137 and strontium- 90 content in the local foodstuffs. The mean annual effective dose to the population has decreased which makes it possible to transfer the settlements affected by the Chernobyl NPP accident to normal life style. This is covered by the draft concept of the settlements’ transfer to normal life style.

  7. Problem areas and research needs on radiation protection in nuclear power plants

    International Nuclear Information System (INIS)

    The Advisory Committee on Reactor Safeguards has been assigned by Congress the responsibility to prepare an annual review of the reactor safety research program of the U.S. Nuclear Regulatory Commission. The first Committee report on this subject was published in December, 1977, and a second is under preparation. Among the many topics considered were the evaluation and control of occupational radiation exposures at commercial nuclear power plants. Areas relative to exposure evaluation that have been identified as needing attention at the present time include improved techniques for monitoring occupational neutron exposures, better data collection and analysis with respect to internally deposited radionuclides, and an up-grading in quality control procedures in the manufacture of radiation monitoring instruments. Areas relative to exposure control that have been identified as needing attention include the development of additional design and manufacturing approaches for preventing the production and buildup of key radionuclides within reactor cooling systems; the development and testing of techniques for removing those radionuclides which do accumulate in the system; the application of risk/benefit assessments to procedures for the maintenance, repair, modification, replacement, and disposal of major nuclear power plant components, such as steam generators; and the development of design features that would facilitate decommissioning of nuclear power plants. Also in need of further development are procedures for conducting cost/benefit assessments of the value of increased inplant inspections and further recycling and reuse of waste effluents. (author)

  8. Background radiation from fission pulses

    Energy Technology Data Exchange (ETDEWEB)

    England, T.R.; Arthur, E.D.; Brady, M.C.; LaBauve, R.J.

    1988-05-01

    Extensive source terms for beta, gamma, and neutrons following fission pulses are presented in various tabular and graphical forms. Neutron results from a wide range of fissioning nuclides (42) are examined and detailed information is provided for four fuels: /sup 235/U, /sup 238/U, /sup 232/Th, and /sup 239/Pu; these bracket the range of the delayed spectra. Results at several cooling (decay) times are presented. For ..beta../sup -/ and ..gamma.. spectra, only /sup 235/U and /sup 239/Pu results are given; fission-product data are currently inadequate for other fuels. The data base consists of all known measured data for individual fission products extensively supplemented with nuclear model results. The process is evolutionary, and therefore, the current base is summarized in sufficient detail for users to judge its quality. Comparisons with recent delayed neutron experiments and total ..beta../sup -/ and ..gamma.. decay energies are included. 27 refs., 47 figs., 9 tabs.

  9. The spatial statistics formalism applied to mapping electromagnetic radiation in urban areas.

    Science.gov (United States)

    Paniagua, Jesus M; Rufo, Montaña; Jimenez, Antonio; Antolin, Alicia

    2013-01-01

    Determining the electromagnetic radiation levels in urban areas is a complicated task. Various approaches have been taken, including numerical simulations using different models of propagation, sampling campaigns to measure field values with which to validate theoretical models, and the formalism of spatial statistics. In the work, we present here that this latter technique was used to construct maps of electric field and its associated uncertainty from experimental data. For this purpose, a field meter and a broadband probe sensitive in the 100-kHz-3-GHz frequency range were used to take 1,020 measurements around buildings and along the perimeter of the area. The distance between sampling points was 5 m. The results were stored in a geographic information system to facilitate data handling and analysis, in particular, the application of the formalism of spatial statistical to the analysis of the distribution of the field levels over the study area. The spatial structure was analyzed using the variographic technique, with the field levels at non-sampled points being interpolated by kriging. The results indicated that, in the urban area analyzed in the present work, the linear density of sampling points could be reduced to a distance which coincides with the length of the blocks of buildings without the statistical parameters varying significantly and with the field level maps being reproduced qualitatively and quantitatively.

  10. Evaluation of daily intake for some elements of radiation protection concern by inhabitants of Greater Cairo Area, Egypt

    Directory of Open Access Journals (Sweden)

    Mohamed H.E. Monged

    2016-07-01

    Full Text Available Concentrations of K, Ca, U, Th, Cs, Sr, I, Al, Cd, Cu, Mn, Pb, Ni, Zn and Cr were determined in common foodstuffs consumed by adult inhabitants of Greater Cairo Area (GCA. Some of these elements have chemical and biological similarity to some of the radionuclides abundantly encountered during nuclear power production and therefore data on these elements could provide important information on their biokinetic behavior. A total of 120 samples were analyzed using Neutron Activation Analysis (NAA and Atomic Absorption Spectrometry (AAS. Highest contributions for the intake of micronutrients (Cu, Mn, Ni and Zn arise from broad bean, rice and wheat flour consumption. Meat, milk, eggs and some vegetables are the major sources of K, Ca, U, Th, Cs, Al, Cd and Pb intake. The medium daily intakes for the adult inhabitants of GCA from the analyzed elements were reported. The lower daily intake of Ca, Th, Cs and I by adult inhabitants of GCA could be due to significantly lower consumption of milk and milk products. The significantly lower intake of calcium by adult inhabitants of GCA may lead to higher uptake of radiostrontium and could result in perhaps higher internal radiation dose. The lower intake values obtained for thorium and uranium, which suggests that radiation dose from their ingestion at natural background levels, is likely to be lower than what may be concluded from International Commission on Radiological Protection (ICRP data. Concerning micronutrients, the recommended values of daily intake of Cu and Mn are conveniently supplied by diet; however, for Cr and Zn they are lower than the recommended daily allowance. Due to high metals concentrations and consumption rates, broad bean is the foodstuff that provided the highest ingestion rates of Cu, Mn, Ni and Zn, being therefore a very important source of micronutrients.

  11. Epidemiological studies of radio-frequency radiation: Current status and areas of concern

    Energy Technology Data Exchange (ETDEWEB)

    Goldsmith, John R. [Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva (Israel)

    1996-02-11

    These comments deal with the possible impact on human populations of intense sources of radio-frequency radiation, and not the much lower level of the usual sources of such radiation associated, for example with household appliances. These intense sources were developed and extensively used first in World War II (1940-45). Much of the health evaluation has been done by, and for, military organizations. There are important differences in the energy generated by low frequency (ELF) and radar; it then follows that there may be differences in their effects on human populations. Problems common to both types are: (1) the uncertainty as to biological mechanisms; (2) weak experimental evidence of effect; (3) epidemiological preoccupation with carcinogenesis, with its latency and low incidence. For both types there is the presumption of greater occupational than community risk, the latter often not well studied, and problems as to exposure quantification and specificity. To these one must add (4) the inherently epidemiological problems of a study at a given source of adequate sample size, case-findings, exposure estimation, confounders, and residential and job instability. Despite these problems, there are findings from sets of studies which suggest four possible health effects from radar (radio-frequency radiation) exposure: (A) disturbances in blood counts, not necessarily of clinical severity; (B) changes in chromosomes of white blood cells; (C) increases in frequency of unfavorable reproductive outcomes, especially spontaneous abortion, and (D) increases in cancers of certain sites. A review article on this topic was published elsewhere, providing evidence from various exposures on such possible effects. A brief critique is provided of evidence on these four possible effects, identifying some areas of uncertainty for which studies at sites like Skrunda could provide useful information

  12. [The perception of the radiation situation and assessment of their own health status by the population living in an area under strict radiation control].

    Science.gov (United States)

    Ferents, V P; Prilipko, V A; Blizniuk, I D

    1991-01-01

    Studies of subjective perception of the radiation situation, self-estimation of the health status by the population, the attitude of the population to the formal information available were carried out in the strong radiation control areas and in the regions not polluted by radioactive fallout. Before the accident 71.6% of the population were not aware of real danger of radiation for health. During the accident and after it, mass media were the main source of information on the consequences of the accident and the effect of radiation (71.1%). 38% of the information was provided by scientists and specialists. 89.6% of the persons interviewed experience anxiety whatever the intelligence available. Only 13.4% of those who live in the areas polluted by radionuclides feel well. The low self-estimation of the health status, the high level of anxiety together with the deficiency of radiation and hygienic intelligence favour the forcing of the social and psychological tension and reduce the effectiveness of the whole complex of measures carried out in the areas polluted with radionuclides. PMID:1666225

  13. Measurements and simulations of the BLM response to a radiation field inside the CERF target area

    CERN Document Server

    Lebbos, E; Dehning, B; Effinger, E; Ferrari, A; Kramer, D; Nordt, A; Roeed, K; Roesler, S; Sapinski, M; Vlachoudis, V

    2010-01-01

    The CERN-EU high-energy reference field (CERF) facility is installed in one of the secondary beam lines (H6) of the Super Proton Synchrotron (SPS), in the North Experimental Area at CERN. This facility is used as a reference for testing, inter-comparing and calibrating passive and active instruments. In May 2009, the SPS provided a mixed hadron beam (protons, pions and kaons) during a few days, in order to perform several measurements with different devices such as the Radiation Protection Monitor used for residual dose rates due to Induced Radioactivity in the LHC (PMI), the Secondary Emission Monitor used for high beam losses (SEM), the Radiation Monitor for electronics (RadMon), and the Beam Loss Monitor for the LHC (BLM). This report focuses on the measurements of the BLM response during this year’s operation at CERF. The measurements evaluate the sensitivity of the BLM signal to the particle energy spectrum, with special attention to the contribution coming from thermal neutrons. For this purpose, meas...

  14. Offsite environmental monitoring report. Radiation monitoring around United States nuclear test areas, calendar year 1983

    International Nuclear Information System (INIS)

    This report covers the routine radiation monitoring activities conducted by the Environmental Monitoring Systems Laboratory-Las Vegas in areas which may be affected by nuclear testing programs of the Department of Energy. This monitoring is conducted to document compliance with standards, to identify trends in environmental radiation, and to provide such information to the public. It summarizes these activities for calendar year 1983. No radioactivity attributable to NTS activities was detectable offsite by the monitoring networks. Using recorded wind data and Pasquill stability categories, atmospheric dispersion calculations based on reported radionuclide releases yield an estimated dose of 5 x 10-5 man-rem to the population within 80 km of the Nevada Test Site during 1983. World-wide fallout of Kr-85, Sr-90, Cs-137, and Pu-239 detected by the monitoring networks would cause maximum exposure to an individual of less than 0.2 mrem per year. Plutonium and krypton in air were similar to 1982 levels while cesium and strontium in other samples were near the detection limits. An occasional net exposure to offsite residents has been detected by the TLD network. On investigation, the cause of such net exposures has been due to personal habits or occupational activities, not to NTS activities. 29 references, 35 figures, 30 tables

  15. Terrestrial gamma dose rate, radioactivity and radiological hazards in the rocks of an elevated radiation background in Juban District, Ad Dali' Governorate, Yemen.

    Science.gov (United States)

    Abdurabu, Wedad Ali; Ramli, Ahmad Termizi; Saleh, Muneer Aziz; Heryansyah, Arien; Alnhary, Anees; Fadhl, Shadi

    2016-03-01

    This study aims to evaluate natural radiation and radioactivity in the rock and to assess the corresponding health risk in a region of elevated background radiation in Juban District, Ad Dali' Governorate, Yemen. The mean external gamma dose rate was 374 nGy h(-1) which is approximately six times the world average. The measured results were used to compute annual effective dose equivalent, collective effective dose and excess lifetime cancer risk, which are 2.298 mSv, 61.95 man Sv y(-1) and 8.043  ×  10(-3), respectively. Rocks samples from different geological formations were analyzed for quantitative determination of (226)Ra, (232)Th and (40)K. The specific activity of the rocks samples ranges from 7  ±  1 Bq Kg(-1) to 12 513  ±  329 Bq Kg(-1) for (232)Th, from 6  ±  1 Bq kg(-1) to 3089  ±  74 Bq kg(-1) for (226)Ra and 702  ±  69 Bq kg(-1) to 2954  ±  285 Bq kg(-1) for (40)K. (232)Th is the main contributor to gamma dose rate from the rock samples. Indicators of radiological health impact, radium equivalent activity and external hazard index are 3738 Bq kg(-1) and 10.10, respectively. The mean external hazard index was ten times unity in the studied locations in Juban District, which is higher than the recommended value. PMID:26909670

  16. Indoor gamma radiation and radon concentrations in a Norwegian carbonatite area

    Energy Technology Data Exchange (ETDEWEB)

    Sundal, A.V. E-mail: aud.sundal@geo.uib.no; Strand, T

    2004-07-01

    Results of indoor gamma radiation and radon measurements in 95 wooden dwellings located in a Norwegian thorium-rich carbonatite area using thermoluminescent dosemeters and CR-39 alpha track detectors, respectively, are reported together with a thorough analysis of the indoor data with regard to geological factors. Slightly enhanced radium levels and thorium concentrations of several thousands Bq kg{sup -1} in the carbonatites were found to cause elevated indoor radon-222 levels and the highest indoor gamma dose rates ever reported from wooden houses in Norway. An arithmetic mean indoor gamma dose rate of 200 nGy h{sup -1} and a maximum of 620 nGy h{sup -1} were obtained for the group of dwellings located directly on the most thorium-rich bedrock.

  17. Indoor gamma radiation and radon concentrations in a Norwegian carbonatite area.

    Science.gov (United States)

    Sundal, A V; Strand, T

    2004-01-01

    Results of indoor gamma radiation and radon measurements in 95 wooden dwellings located in a Norwegian thorium-rich carbonatite area using thermoluminescent dosemeters and CR-39 alpha track detectors, respectively, are reported together with a thorough analysis of the indoor data with regard to geological factors. Slightly enhanced radium levels and thorium concentrations of several thousands Bq kg(-1) in the carbonatites were found to cause elevated indoor radon-222 levels and the highest indoor gamma dose rates ever reported from wooden houses in Norway. An arithmetic mean indoor gamma dose rate of 200 nGy h(-1) and a maximum of 620 nGy h(-1) were obtained for the group of dwellings located directly on the most thorium-rich bedrock. PMID:15312702

  18. X-Ray Ccds for Space Applications: Calibration, Radiation Hardness, and Use for Measuring the Spectrum of the Cosmic X-Ray Background

    Science.gov (United States)

    Gendreau, Keith Charles

    1995-01-01

    This thesis has two distinct components. One concerns the physics of the high energy resolution X-ray charge coupled devices (CCD) detectors used to measure the cosmic X-ray background (XRB) spectrum. The other involves the measurements and analysis of the XRB spectrum and instrumental background with these detectors on board the advanced satellite for cosmology and astrophysics (ASCA). The XRB has a soft component and a hard component divided at ~2 keV. The hard component is extremely isotropic, suggesting a cosmological origin. The soft component is extremely anisotropic. A galactic component most likely dominates the soft band with X-ray line emission due to a hot plasma surrounding the solar system. ASCA is one of the first of a class of missions designed to overlap the hard and soft X-ray bands. The X-ray CCD's energy resolution allows us to spectrally separate the galactic and cosmological components. Also, the resolution offers the ability to test several specific cosmological models which would make up the XRB. I have concentrated on models for the XRB origin which include active galactic nuclei (AGN) as principal components. I use ASCA data to put spectral constraints on the AGN synthesis model for the XRB. The instrumental portion of this thesis concerns the development and calibration of the X-ray CCDs. I designed, built and operated an X-ray calibration facility for these detectors. It makes use of a reflection grating spectrometer to measure absolute detection efficiency, characteristic absorption edge strengths, and spectral redistribution in the CCD response function. Part of my thesis research includes a study of radiation damage mechanisms in CCDs. This work revealed radiation damage-induced degradation in the spectral response to X-rays. It also uncovered systematic effects which affect both data analysis and CCD design. I have developed a model involving trap energy levels in the CCD band gap structure. These traps reduce the efficiency in which

  19. Optimization of measures for radiation safety and social security provision during man-caused radioactive contamination of large areas

    International Nuclear Information System (INIS)

    The paper describes optimization of measures undertaken to overcome effects of the large-scale radiation impact on the ground and population. It generalizes structural and content principles for developing target programs as a proven system of measures reducing the extent of such effects. Authors present a sample set of interdependent measures for provision of radiation safety and social security as applied to the Semipalatinsk Test Site and its affected areas. (author)

  20. Chipmunk IV: development of and experience with a new generation of radiation area monitors for accelerator applications

    International Nuclear Information System (INIS)

    The operation of a high-energy accelerator complex presents challenging problems for radiation monitoring during 'beam-on' conditions. As a response to these needs, Fermilab has developed several families of radiation monitoring instruments intended for use under beam-on conditions. One of these instruments is a tissue equivalent, ion chamber based, area monitor called a 'Chipmunk'. This article describes the latest version of these monitors, specifically the Chipmunk IV, as developed at Fermilab

  1. Chipmunk IV: development of and experience with a new generation of radiation area monitors for accelerator applications

    CERN Document Server

    Krüger, F

    2002-01-01

    The operation of a high-energy accelerator complex presents challenging problems for radiation monitoring during 'beam-on' conditions. As a response to these needs, Fermilab has developed several families of radiation monitoring instruments intended for use under beam-on conditions. One of these instruments is a tissue equivalent, ion chamber based, area monitor called a 'Chipmunk'. This article describes the latest version of these monitors, specifically the Chipmunk IV, as developed at Fermilab.

  2. On the assignment of professionally radiation exposed persons to the categories A and B and the definition of controlled areas

    International Nuclear Information System (INIS)

    Some help is given for the definition of controlled areas, and for the classification of the personnel working with radioactive material. This is based on the 'Regulations for the Physical Radiation Protection Control' apart from the German radiation protection rules. While table 2 and 3, the affiliated equations 1 and 2 in connection with figure 1 serve to evaluate the external exposition, the limiting values of the different categories of radiation exposed persons, determined by the activities handled daily and the supposed incorporation rate, can be read from table 5 for several well-known nuclides. (orig.)

  3. MM5 Simulations of the China Regional Climate During the LGM.Ⅱ: Influence of Change of Land Area, Vegetation, and Large-scale Circulation Background

    Institute of Scientific and Technical Information of China (English)

    LIU Yu; HE Jinhai; LI Weiliang; CHEN Longxun

    2008-01-01

    Using a regional climate model MM5 nested to an atmospheric global climate model CCM3, a series of simulations and sensitivity experiments have been performed to investigate the relative LGM climate response to changes of land-sea distribution, vegetation, and large-scale circulation background over China.Model results show that compared with the present climate, the fluctuations of sea-land distribution in eastern Asia during the LGM result in the temperature decrease in winter and increase in summer. It has significant impact on the temperature and precipitation in the east coastal region of China. The impact on precipitation in the east coastal region of China is the most significant one, with 25%-50% decrease in the total precipitation change during the LGM. On the other hand, the changes in sea-land distribution have less influence on the climate of inland and western part of China. During the LGM, significant changes in vegetation result in temperature alternating with winter increase and summer decrease, but differences in the annual mean temperature are minor. During the LGM, the global climate, i.e., the large-scale circulation background has changed significantly. These changes have significant influences on temperature and precipitation over China. They result in considerable temperature decreases in this area, and direct the primary patterns and characteristics of temperature changes. Results display that, northeastern China has the greatest temperature decrease, and the temperature decrease in the Tibetan Plateau is larger than in the eastern part of China located at the same latitude. Moreover, the change of large-scale circulation background also controls the pattern of precipitation change. Results also show that, most of the changes in precipitation over western and northeastern parts of China are the consequences of changing large-scale circulation background, of which 50%-75% of precipitation changes over northern and eastern China are the

  4. Large area 3-D optical coherence tomography imaging of lumpectomy specimens for radiation treatment planning

    Science.gov (United States)

    Wang, Cuihuan; Kim, Leonard; Barnard, Nicola; Khan, Atif; Pierce, Mark C.

    2016-02-01

    Our long term goal is to develop a high-resolution imaging method for comprehensive assessment of tissue removed during lumpectomy procedures. By identifying regions of high-grade disease within the excised specimen, we aim to develop patient-specific post-operative radiation treatment regimens. We have assembled a benchtop spectral-domain optical coherence tomography (SD-OCT) system with 1320 nm center wavelength. Automated beam scanning enables "sub-volumes" spanning 5 mm x 5 mm x 2 mm (500 A-lines x 500 B-scans x 2 mm in depth) to be collected in under 15 seconds. A motorized sample positioning stage enables multiple sub-volumes to be acquired across an entire tissue specimen. Sub-volumes are rendered from individual B-scans in 3D Slicer software and en face (XY) images are extracted at specific depths. These images are then tiled together using MosaicJ software to produce a large area en face view (up to 40 mm x 25 mm). After OCT imaging, specimens were sectioned and stained with HE, allowing comparison between OCT image features and disease markers on histopathology. This manuscript describes the technical aspects of image acquisition and reconstruction, and reports initial qualitative comparison between large area en face OCT images and HE stained tissue sections. Future goals include developing image reconstruction algorithms for mapping an entire sample, and registering OCT image volumes with clinical CT and MRI images for post-operative treatment planning.

  5. Performance evaluation of the conventional Brazilian industries radiation protection in the small industrial gauges and industrial radiography areas

    International Nuclear Information System (INIS)

    This works evaluates by punctuation the performance in conventional Brazilian industries radiation protection area which make use of small industrial gauges and industrial radiography. It proposes, procedures for industry self-evaluation, besides a new radiation protection plans pattern for the small industrial gauges area. The data source where inspection reports of Dosimetry Radiation Protection Institute/Nuclear Energy Commission conventional Brazilian industries' radiation protection plans, beyond visitation to the inspection place. The performance evaluation has been realized both in the administrative and operational aspects of the industries. About of 60% of the industries have a satisfactory register control which does not happen to the operational control. The performance evaluation advantage is that industries may self-evaluate, foreseeing Dosimetry Radiation Protection Institute's regulation inspections, correcting its irregularities, automatically improving its services. The number of industries which have obtained satisfactory performance in both areas is below 70%, both in administrative and operational aspects. Such number can be considered a low one as it is radiation protection. The procedures propose in this work aim to improve such a situation. (author)

  6. Hanford Site background: Part 3, Groundwater background

    International Nuclear Information System (INIS)

    This report presents and interprets groundwater background data collected from the unconfined aquifer beneath the Hanford Site, a U.S. Department of Energy complex located near Richland, Washington. Characterization of background composition is an important component of environmental characterization activities and serves as a basis for distinguishing the presence and significance of contamination. Background data can also be used to assess the levels of baseline risk to which humans or other receptors are typically exposed and to establish remediation goals. Evaluating background on a sitewide basis provides a consistent, technically defensible definition of background as opposed to determining area-specific background compositions for each waste management unit being considered for remediation across the Hanford Site

  7. Cosmic-Ray Background Flux Model based on a Gamma-Ray Large-Area Space Telescope Balloon Flight Engineering Model

    Energy Technology Data Exchange (ETDEWEB)

    Mizuno, T

    2004-09-03

    Cosmic-ray background fluxes were modeled based on existing measurements and theories and are presented here. The model, originally developed for the Gamma-ray Large Area Space Telescope (GLAST) Balloon Experiment, covers the entire solid angle (4{pi} sr), the sensitive energy range of the instrument ({approx} 10 MeV to 100 GeV) and abundant components (proton, alpha, e{sup -}, e{sup +}, {mu}{sup -}, {mu}{sup +} and gamma). It is expressed in analytic functions in which modulations due to the solar activity and the Earth geomagnetism are parameterized. Although the model is intended to be used primarily for the GLAST Balloon Experiment, model functions in low-Earth orbit are also presented and can be used for other high energy astrophysical missions. The model has been validated via comparison with the data of the GLAST Balloon Experiment.

  8. Radiation dosimetry of small mammals inhabiting a liquid radioactive waste disposal area

    International Nuclear Information System (INIS)

    Radiation doses received by small mammals inhabiting a dry radioactive leaching pond on the Idaho National Engineering Laboratory Site were determined by surgically implanting lithium fluoride thermoluminescent dosimeter (TLD) chips. The TLD packets were implanted in 3 species: white-footed deer mouse, least chipmunk, and Ord's kangaroo rat, with 65% recovery. All species from the radioactive leaching pond received significantly greater doses than control species. The deer mice received a mean dose equivalent rate of 160 mrem/day which was significantly greater than the mean dose equivalent rates received by least chipmunks (17 mrem/day) and Ord's kangaroo rats (6 mrem/day). The mean dose received by deer mice was 8% of the maximum air exposure recorded near the ground surface of the leaching pond. The maximum dose rate received by an individual deer mouse was nearly 50% of the maximum exposure rates in the study plot. Interspecific dose differences appeared to be related to habitat preference. Deer mice were most frequently captured on the gravelly and sparsely vegetated dry pond bed which had site exposure rates of 200 to 2000 mR/day. Conversely, chipmunks and kangaroo rats were usually captured on the pond banks which were adjacent to areas with sandy soil and denser vegetation. Site exposure rates on the pond banks ranged from 20 to 30 mR/day. Doses received by individuals of each species had high variation caused by the variable air exposure rates and the mobility of the small mammals. Intraspecific differences in activity, behavior, and home range may have also influenced the dose variability in individual rodents. The advantage of implanted TLD over externally attached TLD and possible radiation effects on small mammal populations are discussed

  9. Radon-thoron discriminative measurements in the high natural radiation areas of southwestern Cameroon.

    Science.gov (United States)

    Saïdou; Tokonami, Shinji; Janik, Miroslaw; Samuel, Bineng Guillaume; Abdourahimi; Joseph Emmanuel, Ndjana Nkoulou I I

    2015-12-01

    Although indoor radon was initially measured in the uranium regions of Poli and Lolodorf using Electret Ionization Chambers, discriminative RADUET detectors were deployed in 70 houses of the high natural radiation areas of Bikoue and Ngombas in the uranium region of Lolodorf in Southwestern Cameroon. Radon and thoron concentrations were determined using Image-J and Microscope Methods for track evaluation. Radon and thoron concentrations follow lognormal distributions and ranged respectively from 27 ± 26 to 937 ± 5 Bq m(-3) and from 48 ± 40 to 700 ± 128 Bq m(-3). The arithmetic means of radon and thoron concentrations were found to be 92 ± 3 Bq m(-3) and 260 ± 13 Bq m(-3.) Less than 2% of houses have indoor radon above the reference level of 300 Bq m(-3) and 30% of houses have thoron concentrations above 300 Bq m(-3.) Inhalation doses due to radon and thoron range respectively between 0.6-17.7 mSv yr(-1) and 0.2-3 mSv yr(-1) with the mean values of 1.4 mSv yr(-1) and 1 mSv yr(-1). The contribution of indoor thoron to the total inhalation dose ranges between 15%- 78.5% with the mean value of 47%. Thus thoron cannot be neglected when assessing radiation dose.

  10. Effects of terahertz radiation at atmospheric oxygen frequency of 129 GHz on blood nitrite concentrations under conditions of different types of stress against the background of administration of nonselective inhibitor of constitutive NO-synthases.

    Science.gov (United States)

    Kirichuk, V F; Tsymbal, A A

    2012-02-01

    We studied the effect of terahertz radiation at atmospheric oxygen frequency 129 GHz on blood nitrite concentration in different types of experimental stress against the background of administration of nonselective inhibitor of constitutive NO-synthases. Normalizing effects of radiation on blood nitrite dynamics in animals with acute stress was shown after 15-min exposure and in animals with chronic stress after 30-min exposure. No positive effect of terahertz radiation was observed on altered blood nitrite concentration in male rats after preliminary administration of nonselective constitutive NO-synthase isoform inhibitor L-NAME. PMID:22803105

  11. Rural areas affected by the Chernobyl accident: radiation exposure and remediation strategies.

    Science.gov (United States)

    Jacob, P; Fesenko, S; Bogdevitch, I; Kashparov, V; Sanzharova, N; Grebenshikova, N; Isamov, N; Lazarev, N; Panov, A; Ulanovsky, A; Zhuchenko, Y; Zhurba, M

    2009-12-15

    Main objectives of the present work were to develop an internationally agreed methodology for deriving optimized remediation strategies in rural areas that are still affected by the Chernobyl accident, and to give an overview of the radiological situation in the three affected countries, Belarus, Russia and Ukraine. Study settlements were defined by having in 2004 less than 10,000 inhabitants and official dose estimates exceeding 1 mSv. Data on population, current farming practices, contamination of soils and foodstuffs, and remedial actions previously applied were collected for each of such 541 study settlements. Calculations of the annual effective dose from internal radiation were validated with extensive data sets on whole body counter measurements. According to our calculations for 2004, in 290 of the study settlements the effective dose exceeded 1 mSv, and the collective dose in these settlements amounted to about 66 person-Sv. Six remedial actions were considered: radical improvement of grassland, application of ferrocyn to cows, feeding pigs with uncontaminated fodder before slaughter, application of mineral fertilizers for potato fields, information campaign on contaminated forest produce, and replacement of contaminated soil in populated areas by uncontaminated soil. Side effects of the remedial actions were quantified by a 'degree of acceptability'. Results are presented for two remediation strategies, namely, Strategy 1, in which the degree of acceptability was given a priority, and Remediation Strategy 2, in which remedial actions were chosen according to lowest costs per averted dose only. Results are highly country-specific varying from preference for soil replacement in populated areas in Belarus to preference for application of ferrocyn to cows in Ukraine. Remedial actions in 2010 can avert a large collective dose of about 150 person-Sv (including averted doses, which would be received in the following years). Nevertheless, the number of

  12. Comparative radiation impact on biota and man in the area affected by the accident at the Chernobyl nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Fesenko, S.V. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation) and International Atomic Energy Agency, Agency' s Laboratories, Seibersdorf A-2444 (Austria)]. E-mail: s.fesenko@iaea.org; Alexakhin, R.M. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Geras' kin, S.A. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Sanzharova, N.I. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Spirin, Ye.V. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Spiridonov, S.I. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Gontarenko, I.A. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Strand, P. [Norwegian Radiation Protection Authority, Oesteras (Norway)

    2005-07-01

    A methodological approach for a comparative assessment of ionising radiation effects on man and non-human species, based on the use of Radiation Impact Factor (RIF) - ratios of actual exposure doses to biota species and man to critical dose is described. As such doses, radiation safety standards limiting radiation exposure of man and doses at which radiobiological effects in non-human species were not observed after the Chernobyl accident, were employed. For the study area within the 30 km ChNPP zone dose burdens to 10 reference biota groups and the population (with and without evacuation) and the corresponding RIFs were calculated. It has been found that in 1986 (early period after the accident) the emergency radiation standards for man do not guarantee adequate protection of the environment, some species of which could be affected more than man. In 1991 RIFs for man were considerably (by factor of 20.0-1.1 x 10{sup 5}) higher compared with those for selected non-human species. Thus, for the long term after the accident radiation safety standards for man are shown to ensure radiation safety for biota as well.

  13. Background Material

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Hyytiäinen, Kari; Saraiva, Sofia;

    2016-01-01

    This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders.......This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders....

  14. Assessment of radiation safety of a 4 MV Industrial Accelerator Facility using a TLD Based Passive Area Monitor

    International Nuclear Information System (INIS)

    Radiation levels around radiography enclosures where objects to be radiographed are carried into the radiography room by a conveyor belt system moving through a hatch provided at the entrance door, have been of significant concern to plant operators present in the immediate vicinity of the installation. Personal involved in the loading-unloading of jobs on the conveyor belt system and other operators of the plant remain stationed at these locations. Our present study is aimed at estimation of radiation levels at various locations in the immediate vicinity of a 4 MV industrial linear accelerator installation using passive area monitors based on CaSO4: Dy, Teflon TLD disc. The radiation levels measured using (i) passive area monitor and (ii) a portable dose rate meter, were found to be significantly lower than the values calculated for the various locations in the accelerator room. (author)

  15. A method for assessing intercepted radiation by a crop with a low leaf area: an application to oilseed rape

    International Nuclear Information System (INIS)

    Calculation of photosynthetically active radiation interception by a crop with a low leaf area index, particularly when the canopy is not closed, needs a more detailed approach than a simple Beer's law with constant light extinction coefficient (k). This paper introduces a simple procedure for the calculation of intercepted radiation, taking into account the ground cover ratio, and using a small set of parameters. The k coefficient is deduced from this calculation and we show that k depends on the leaf area index, the location and the season. The significance of introducing ground cover ratio in the calculation of intercepted radiation is estimated, and sensitivity of the method to various parameters is assessed

  16. Mammography with and without radiolucent positioning sheets : Comparison of projected breast area, pain experience, radiation dose and technical image quality

    NARCIS (Netherlands)

    Timmers, Janine; ten Voorde, Marloes; van Engen, Ruben E.; van Landsveld-Verhoeven, Cary; Pijnappel, Ruud; Droogh-de Greve, Kitty; den Heeten, Gerard J.; Broeders, Mireille J. M.

    2015-01-01

    Purpose: To compare projected breast area, image quality, pain experience and radiation dose between mammography performed with and without radiolucent positioning sheets. Methods: 184 women screened in the Dutch breast screening programme (May-June 2012) provided written informed consent to have on

  17. Change of Primary Cosmic Radiation Nuclear Conposition in the Energy Range $10^{15} - 10^{17}$ eV as a Result of the Interaction with the Interstellar Cold Background of Light Particles

    CERN Document Server

    Barnaveli, T T; Khaldeeva, I V

    2003-01-01

    In this paper the updated arguments in favor of a simple model, explaining from the united positions all peculiarities of the Extensive Air Shower (EAS) hadron E_h(E_0) (and muon E_mu(E_0)) component energy fluxes dependence on the primary particle energy E_0 in the primary energy region 10^{15} - 10^{17} eV are represented. These peculiarities have shapes of consequent distinct deeps of a widths dE_h/E_h of the order of 0.2 and of relative amplitudes dL/L of the order of {0.1 - 1.0}, and are difficult to be explained via known astrophysical mechanisms of particle generation and acceleration. In the basis of the model lies the destruction of the Primary Cosmic Radiation (PCR) nuclei on some monochromatic background of interstellar space, consisting of the light particles of the mass in the area of 36 eV (maybe the component of a dark matter). The destruction thresholds of PCR different nuclear components correspond to the peculiarities of E_h(E_0). In this work the results of the recent treatment of large sta...

  18. [Development of recommendations in the area of ionizing and nonionizing radiations

    International Nuclear Information System (INIS)

    This document discusses progress made from March 1, 1990 to October 30, 1990 in terms of publication of reports. This subjects discussed are related to the fields of radiation protection and ionizing and nonionizing radiations. Topics discussed published works, reports in press, printer's manuscript preparation, and scientific committee activities

  19. Accurate tissue area measurements with considerably reduced radiation dose achieved by patient-specific CT scan parameters

    DEFF Research Database (Denmark)

    Brandberg, J.; Bergelin, E.; Sjostrom, L.;

    2008-01-01

    for muscle tissue. Image noise was quantified by standard deviation measurements. The area deviation was radiation dose of the low-dose technique was reduced to 2-3% for diameters of 31-35 cm and to 7.5-50% for diameters of 36-47 cm...... as compared with the integral dose by the standard diagnostic technique. The CT numbers of muscle tissue remained unchanged with reduced radiation dose. Image noise was on average 20.9 HU (Hounsfield units) for subjects with diameters of 31-35 cm and 11.2 HU for subjects with diameters in the range of 36...

  20. Radiation

    International Nuclear Information System (INIS)

    The basic facts about radiation are explained, along with some simple and natural ways of combating its ill-effects, based on ancient healing wisdom as well as the latest biochemical and technological research. Details are also given of the diet that saved thousands of lives in Nagasaki after the Atomic bomb attack. Special comment is made on the use of radiation for food processing. (U.K.)

  1. An overview of global solar radiation measurements in Ghardaia area, south Algeria

    OpenAIRE

    Kacem Gairaa, Yahia Bakelli

    2011-01-01

    This paper presents an overview of actual solar radiation data measurements in Ghardaia site (32.360 N, 3.810 W, 450 m above MSL). Global solar radiation and surface temperatures were measured and analyzed for one complete year from 1 January-31December 2005. The data thus recorded are compared with corresponding data of the 22-year average of NASA's surface meteorology and solar energy-model. Hourly, daily and monthly solar radiation was made from five-minute recorded by EKO Pyranometer. The...

  2. Measures against increased environmental radiation dose by the TEPCO Fukushima Dai-ichi NPP accident in some local governments in the tokyo metropolitan area: Focusing on examples of both Kashiwa and Nagareyama cities in Chiba prefecture

    International Nuclear Information System (INIS)

    The accident of the Fukushima Dai-ichi nuclear power plant of Tokyo Electric Power Cooperation (TEPCO) after the great east Japan earthquake (11 March 2011) elevated the background level of environmental radiation in Eastern Japan. Around the Tokyo metropolitan area, especially around Kashiwa and Nagareyama cities, the ambient dose equivalent rate has been significantly increased after the accident. Responding to strong requests from citizens, the local governments started to monitor the ambient dose equivalent rate precisely and officially, about 3 months after the accident had occurred. The two cities in cooperation with each other also organised a local forum supported by three radiation specialists. In this article, the activities of the local governments are introduced, with main focus on radiation monitoring and measurements. Topics are standardisation of environmental radiation measurements for ambient dose rate, dose mapping activity, investigation of foodstuff and drinking water, lending survey meters to citizens, etc. Based on the data and facts mainly gained by radiation monitoring, risk management and relating activity have been organised. 'Small consultation meetings in kindergartens', 'health consultation service for citizens', 'education meeting on radiation protection for teachers, medical staffs, local government staffs, and leaders of active volunteer parties' and 'decontamination activity', etc. are present key activities of the risk management and restoration around the Tokyo metropolitan area. (authors)

  3. Radiation induced F1 sterility in Lepidoptera for area-wide control

    International Nuclear Information System (INIS)

    Very high doses of ionizing radiation are required to induce sterility in Lepidoptera, but fully sterilizing doses are detrimental to the reproductive competitiveness of the insects and so irradiated males are much less able to compete for mates. It appears, however, that inherited sterility can be induced in all Lepidoptera species by means of radiation doses that induce only low levels of sterility in irradiated individuals. In this way the detrimental effects of irradiation on reproductive performance can be largely avoided, and the irradiated males are able to compete for females with their wild counterparts. This is the basis of radiation induced F1 sterility for genetic pest control. These proceedings include thirteen papers on different aspects of F1 sterility, with emphasis on laboratory experiments to determine the dose of gamma radiation required for inherited sterility. The individual papers have been indexed separately. Refs, figs and tabs

  4. An overview of global solar radiation measurements in Ghardaia area, south Algeria

    Directory of Open Access Journals (Sweden)

    Kacem Gairaa, Yahia Bakelli

    2011-03-01

    Full Text Available This paper presents an overview of actual solar radiation data measurements in Ghardaia site (32.360 N, 3.810 W, 450 m above MSL. Global solar radiation and surface temperatures were measured and analyzed for one complete year from 1 January-31December 2005. The data thus recorded are compared with corresponding data of the 22-year average of NASA's surface meteorology and solar energy-model. Hourly, daily and monthly solar radiation was made from five-minute recorded by EKO Pyranometer. The highest measured daily and monthly mean solar radiation was found to be 369 and 326 (W/m2, and the highest five minute averaged solar radiation values up to 1268 (W/m2 were observed in the summer season from May to September, and the yearly average daily energy input was 21.83 (MJ/m2/day. Besides the global solar radiation, the daily and monthly average temperature variations are discussed. The collected data indicate that Ghardaia has a strong potential for solar energy applications.

  5. Sex ratio at birth: scenario from normal- and high-level natural radiation areas of Kerala coast in south-west India.

    Science.gov (United States)

    Koya, P K M; Jaikrishan, G; Sudheer, K R; Andrews, V J; Madhusoodhanan, M; Jagadeesan, C K; Das, Birajalaxmi

    2015-11-01

    Newborns were monitored for congenital malformations in four government hospitals located in high-level (ambient dose >1.5 mGy/year) and normal-level (≤ 1.5 mGy/year) natural radiation areas of Kerala, India, from August 1995 to December 2012. Sex ratio at birth (SRB) among live singleton newborns and among previous children, if any, of their mothers without history of any abortion, stillbirth or twins is reported here. In the absence of environmental stress or selective abortion of females, global average of SRB is about 1050 males to 1000 females. A total of 151,478 singleton, 1031 twins, 12 triplets and 1 quadruplet deliveries were monitored during the study period. Sex ratio among live singleton newborns was 1046 males (95 % CI 1036-1057) for 1000 females (77,153 males:73,730 females) and was comparable to the global average. It was similar in high-level and normal-level radiation areas of Kerala with SRB of 1050 and 1041, respectively. It was consistently more than 1000 and had no association with background radiation levels, maternal and paternal age at birth, parental age difference, gravida status, ethnicity, consanguinity or year of birth. Analysis of SRB of the children of 139,556 women whose reproductive histories were available suggested that couples having male child were likely to opt for more children and this, together with enhanced rate of males at all birth order, was skewing the overall SRB in favour of male children. Though preference for male child was apparent, extreme steps of sex-selective abortion or infanticide were not prevalent. PMID:26343038

  6. Determination of atmospheric parameters to estimate global radiation in areas of complex topography: Generation of global irradiation map

    International Nuclear Information System (INIS)

    Incoming shortwave solar radiation is an important parameter in environmental applications. A detailed spatial and temporal analysis of global solar radiation on the earth surface is needed in many applications, ranging from solar energy uses to the study of agricultural, forest and biological processes. At local scales, the topography is the most important factor in the distribution of solar radiation on the surface. The variability of the elevation, the surface orientation and the obstructions due to elevations are a source of great local differences in insolation and, consequently, in other variables as ground temperature. For this reason, several models based on GIS techniques have been recently developed, integrating topography to obtain the solar radiation on the surface. In this work, global radiation is analyzed with the Solar Analyst, a model implemented on ArcView, that computes the topographic parameters: altitude, latitude, slope and orientation (azimuth) and shadow effects. Solar Analyst uses as input parameters the diffuse fraction and the transmittance. These parameters are not usually available in radiometric networks in mountainous areas. In this work, a method to obtain both parameters from global radiation is proposed. Global radiation data obtained in two networks of radiometric stations is used: one located in Sierra Magina Natural Park (Spain) with 11 stations and another one located on the surroundings of Sierra Nevada Natural Park (Spain) with 14 stations. Daily solar irradiation is calculated from a digital terrain model (DTM), the daily diffuse fraction, K, and daily atmospheric transmittivity, τ. Results provided by the model have been compared with measured values. An overestimation for high elevations is observed, whereas low altitudes present underestimation. The best performance was also reported during summer months, and the worst results were obtained during winter. Finally, a yearly global solar irradiation map has been produced

  7. Determination of atmospheric parameters to estimate global radiation in areas of complex topography: Generation of global irradiation map

    Energy Technology Data Exchange (ETDEWEB)

    Batlles, F.J.; Bosch, J.L. [Dpto. Fisica Aplicada, Universidad de Almeria, 04120 Almeria (Spain); Tovar-Pescador, J. [Dpto. Fisica, Universidad de Jaen, 23071 Jaen (Spain); Martinez-Durban, M. [Dpto. Ingenieria Lenguajes y Computacion, Universidad de Almeria, 04120 Almeria (Spain); Ortega, R. [Dpto. Edafologia y Quimica Agricola, Universidad de Almeria, 04120 Almeria (Spain); Miralles, I. [Dpto. Edafologia y Quimica Agricola, Universidad de Granada, 28071 Granada (Spain)

    2008-02-15

    Incoming shortwave solar radiation is an important parameter in environmental applications. A detailed spatial and temporal analysis of global solar radiation on the earth surface is needed in many applications, ranging from solar energy uses to the study of agricultural, forest and biological processes. At local scales, the topography is the most important factor in the distribution of solar radiation on the surface. The variability of the elevation, the surface orientation and the obstructions due to elevations are a source of great local differences in insolation and, consequently, in other variables as ground temperature. For this reason, several models based on GIS techniques have been recently developed, integrating topography to obtain the solar radiation on the surface. In this work, global radiation is analyzed with the Solar Analyst, a model implemented on ArcView, that computes the topographic parameters: altitude, latitude, slope and orientation (azimuth) and shadow effects. Solar Analyst uses as input parameters the diffuse fraction and the transmittance. These parameters are not usually available in radiometric networks in mountainous areas. In this work, a method to obtain both parameters from global radiation is proposed. Global radiation data obtained in two networks of radiometric stations is used: one located in Sierra Magina Natural Park (Spain) with 11 stations and another one located on the surroundings of Sierra Nevada Natural Park (Spain) with 14 stations. Daily solar irradiation is calculated from a digital terrain model (DTM), the daily diffuse fraction, K, and daily atmospheric transmittivity, {tau}. Results provided by the model have been compared with measured values. An overestimation for high elevations is observed, whereas low altitudes present underestimation. The best performance was also reported during summer months, and the worst results were obtained during winter. Finally, a yearly global solar irradiation map has been

  8. Ionizing and non Ionizing radiation damage in a large area CMOS active pixel sensor for medical applications

    OpenAIRE

    Esposito, Michela; Anaxagoras, Thalis; Price, Tony; Manolopoulos, Spyros; Evans, Philip; Wells, Kevin; Allinson, Nigel

    2015-01-01

    Currently, large-area medical sensors are based on amorphous flat panel technology. Sensors based on monolithic CMOS APS can offer many advantages in terms of image quality and reduced dose requirements. One constraint on the take-up of APS has been their restricted operating life due to radiation damage. Here we present a new wafer scale CMOS APS, designed for medical applications and hardened-by-design with reference to its performance in typical operating environments. The detector was ...

  9. Physical Experiences of the Nuclear Explosions in the Semipalatinsk Area : Radiation Exposure Level and Distance from the Hypocenter

    OpenAIRE

    Kawano, Noriyuki; Hirabayashi, Kyoko; Matsuo, Masatsugu; HIRAOKA,Takashi; Hoshi, Masaharu; Muldagaliev, Talgat; Apsalikov, Kazbek; Ohtaki, Megu

    2009-01-01

    The present paper has three aims related to important, direct experiences of the nuclear explosions among persons living near the Semipalatinsk Nuclear Test Site (SNTS). The first is to describe those experiences. The second is to examine their association with the radiation exposure. The third is to clarify their relationship with distance from the center of the nuclear test area. We examined responses to a questionnaire survey conducted from 2002 to 2005 and analyzed them using logistic reg...

  10. Spectral characteristic of infrared radiations of some acupoint and non-acupoint areas in human arm surface

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Using infrared spectrum detective device, we experiment onNeiguan, Laogong and Hegu acupoints of seven adult volunteers as well as contrastive points beside ones. We get 63 infrared spectrums. The experiment outcome tells us that the differences of the intensities among individuals are great, and so are the differences between acupoint and non-acupoint areas. However, the differences of spectral character are small, which indicates that infrared radiations of human body are based on the same biophysical fundament.

  11. Contribution of Topography and Incident Solar Radiation to Variation of Soil and Plant Litter at an Area with Heterogeneous Terrain

    Directory of Open Access Journals (Sweden)

    Felipe Cito Nettesheim

    2015-06-01

    Full Text Available Natural processes that determine soil and plant litter properties are controlled by multiple factors. However, little attention has been given to distinguishing the effects of environmental factors from the effects of spatial structure of the area on the distribution of soil and litter properties in tropical ecosystems covering heterogeneous topographies. The aim of this study was to assess patterns of soil and litter variation in a tropical area that intercepts different levels of solar radiation throughout the year since its topography has slopes predominantly facing opposing geographic directions. Soil data (pH, C, N, P, H+Al, Ca, Mg, K, Al, Na, sand, and silt and plant litter data (N, K, Ca, P, and Mg were gathered together with the geographic coordinates (to model the spatial structure of 40 sampling units established at two sites composed of slopes predominantly facing northwest and southeast (20 units each. Soil and litter chemical properties varied more among slopes within similar geographic orientations than between the slopes facing opposing directions. Both the incident solar radiation and the spatial structure of the area were relevant in explaining the patterns detected in variation of soil and plant litter. Individual contributions of incident solar radiation to explain the variation in the properties evaluated suggested that this and other environmental factors may play a particularly relevant role in determining soil and plant litter distribution in tropical areas with heterogeneous topography. Furthermore, this study corroborates that the spatial structure of the area also plays an important role in the distribution of soil and litter within this type of landscape, which appears to be consistent with the action of water movement mechanisms in such areas.

  12. First vs. second rotation of a poplar short rotation coppice: leaf area development, light interception and radiation use efficiency

    Directory of Open Access Journals (Sweden)

    Broeckx LS

    2015-10-01

    Full Text Available Given the high expectations for lignocellulosic biomass as one of the potential solutions for energy security and climate change mitigation, commercial scale studies over several rotations are crucial to assess the potential and the sustainability of short rotation coppice (SRC cultures for bioenergy. The first and the second rotation of the SRC poplar (Populus plantation of the present study differed significantly in biomass yield and in productivity determinants and their relationships. Coppicing enhanced leaf area development, radiation interception and woody biomass productivity. High total leaf area and radiation use efficiency (RUE equally contributed to the high biomass yield during the establishment rotation, while RUE became the most important determinant of biomass yield after coppice. The study confirmed the significant genotypic variation in biomass productivity and its underlying determinants, also among more recently selected poplar genotypes. The absence of a correlation between intercepted radiation and RUE suggests the potential of selecting for genotypes combining high total leaf area and photosynthetic carbon uptake in future breeding programs for yield maximization towards sustainable bioenergy cultivation.

  13. Environmental Radiation Monitoring at the Areas of the Former Military Technical Bases at the Russian Far East - 12445

    International Nuclear Information System (INIS)

    After termination of operation at the serviced facilities of the nuclear fleet of the former Soviet Union, the Military Technical Base in Sysoeva Bay has been reorganized to the site for SNF and RW temporary storage (STS). The main activities of STS are receipt, storage and transmission to radioactive waste reprocessing. Establishment of the RW management regional centre in the Far-Eastern region at the STS in Sysoeva Bay implies intensification of SNF and RW management in this region that can result in increasing ecological load to the adjacent areas and settlements. Regulatory supervision of the radiation safety at the areas of the Former Military Technical Bases at the Russian Far East is one of the regulatory functions of the Federal Medical Biological Agency (FMBA of Russia). To regulate SNF an RW management and provide the effective response to changing radiation situation, the environmental radiation monitoring system is arranged. For this purpose, wide range of environmental media examinations at the Sysoeva Bay STS was performed by Burnasyan Federal Medical Biophysical Centre - a technical support organization of FMBA of Russia in collaboration with the Federal State Geological Enterprise 'Hydrospecgeology' (Federal Agency for Entrails). Regulation during the RW and SNF management is continuous process, which the FMBA of Russia implements in close cooperation with other Russian responsible authorities - the State Atomic Energy Corporation 'Rosatom' and Federal Agency for Entrails. The Environmental radiation monitoring findings served as a basis for the associated databank arrangement. The radio ecological monitoring system was arranged at the facilities under inspection for the purpose of the dynamic control of the radiation situation. It presupposes regular radiometry inspections in-situ, their analysis and assessment of the radiation situation forecast in the course of the STS remediation main stages. Some new data on the radiation situation at the

  14. Aspects of Radiation Budget, Subsurface Lateral Moisture Exchange, and Vegetation Function in Areas of Complex Topography.

    Science.gov (United States)

    Ivanov, V. Y.; Bras, R. L.; Istanbulluoglu, E.; Vivoni, E. R.

    2004-12-01

    There is evidence that topography strongly affects the state, function, and distribution of vegetation by controlling incoming solar radiation and lateral redistribution of soil moisture. However, numerical experiments studying the effects that a topography can have on vegetation have oversimplified the treatment of topography and/or the representation of vegetation. We investigate the control of topography on vegetation state and stress via detailed modeling of radiation and soil moisture budgets across the varied terrain of a watershed. A detailed vegetation-hydrology model parameterizes the processes of canopy radiative transfer and rainfall interception and couples the processes of infiltration and evapotranspiration to photosynthesis via moisture uptake through a root systems with varied profiles. The model is applied on a continuous basis to synthetic watersheds of topography dominated by either convex or concave hillslopes. The numerical analysis is carried out for several plant functional types and soils. Inferences from the spatially-distributed dynamics are used to examine topographic niches favorable to vegetation.

  15. Radiation hardness of a large area CMOS active pixel sensor for bio-medical applications

    OpenAIRE

    Esposito, M; Diaz, O; Wells, K.; Anaxagoras, T; Allinson, NM

    2012-01-01

    A wafer scale CMOS Active Pixel Sensor has been designed employing design techniques of transistor enclosed geometry and P+ doped guard rings to offer ionizing radiation tolerance. The detector was irradiated with 160 kVp X-rays up to a total dose of 94 kGy(Si) and remained functional. The radiation damage produced in the device has been studied, resulting in a dark current density increase per decade of 96±5 pA/cm/decade and a damage threshold of 204 Gy(Si). The damage produced in the detect...

  16. The Swedish Radiation Protection Institute's regulations concerning the final management of spent nuclear fuel and nuclear waste - with background and comments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-11-01

    This report presents and comments on the Swedish Radiation Protection Institute's Regulations concerning the Protection of Human Health and the Environment in connection with the Final Management of Spent Nuclear Fuel or Nuclear Waste, SSI FS 1998: 1.

  17. Morphological and transcriptional response of an anhydrobiotic insect to ionizing radiation and desiccation: steps forward in understanding molecular background of extreme radioresistance in higher eukaryotes

    Science.gov (United States)

    Gusev, Oleg; Novikova, Nataliya; Sychev, Vladimir; Okuda, Takashi; Kikawada, Takahiro; Sakashita, Tetsuya; Mukae, Kyosuke

    2012-07-01

    Life in extreme or drastically changing environments in many cases leads to evolutionary evolvement of mechanisms of cross-resistance to different abiotic stresses, often never actually faced by the organism in its natural habitat. Larvae of the sleeping chironomidPolypedilum vanderplanki (Diptera) are able to resist complete desiccation and in the dry form survive under excess of various abiotic stresses, including exposure to space environment. One of the most intriguing features of the anhydrobiotic larvae is resistance to extremely high doses of different types of ionizing radiation. To understand the cross-tolerance mechanism, we have analyzed the structural changes in the nuclear DNA using transmission electron microscopy and DNA comet assays in relation to anhydrobiosis and radiation. We find that dehydration causes alterations in chromatin structure and a severe fragmentation of nuclear DNA in the cells of the larvae despite successful anhydrobiosis. The DNA fragmentation level and the recovery of DNA integrity in the rehydrated after anhydrobiosis larvae were similar to those of hydrated larvae irradiated with 70 Gy of high-linear energy transfer (LET) ions (4He+). In comparison, low-LET radiation (gamma rays) of the same dose causes less initial damage to the larvae, and recovery of DNA repair is complete within 24 h. Genome-wide analysis of mRNA expression in the larvae revealed that a large group of genes (including antioxidants, anhydrobiosis-specific biomolecules and protein-reparation enzymes) showed a similar patterns of activity in response to both desiccation and ionizing radiation. We conclude that t one of the factors explaining the relationship between the resistance to ionizing radiation and the ability to undergo anhydrobiosis in the sleeping chironomid would be an adaptation to desiccation-inflicted proteins and nuclear DNA damage.

  18. Radiation-induced emesis in cats prevented by 24-hour prior exposure but not by ablation of the area postrema

    International Nuclear Information System (INIS)

    The acute emetic response induced by whole body exposure to cobalt radiation was quantified in cats at doses ranging from 1500 to 9000 rad (100 rad/min). Emesis occurred in a dose-related manner with a maximum incidence of 94% at 4500 rad (11 of 12 cats, mean latency of 98 min). At 6000 rad emesis occurred in 7 of 10 cats (mean latency of 69 min); however, a second exposure to this dose on the following day failed to induce vomiting in all of 5 cats (difference between groups significant at p = .01). After chronic ablation of the area postrema (chemoreceptor trigger zone for vomiting), 4 of 5 cats vomited in response to 4500 rad with a mean latency of 48 min. As was the case with the normal cats, all the postrema-ablated animals failed to vomit in response to a repeated dose of radiation delivered on the next day. The suppression of emesis observed on the second exposure was radiation-specific because 11 of 12 normal cats vomited appropriately in response to xylazine (0.6 mg/kg, im) during the period of refractoriness to radiation

  19. Transformation of the angular power spectrum of the Cosmic Microwave Background (CMB) radiation into reciprocal spaces and consequences of this approach

    CERN Document Server

    Červinka, L

    2011-01-01

    In this contribution we undertake an attempt to interpret the anisotropy spectrum of relict radiation after its transformation into a special two-fold reciprocal space in which the interaction of relict photons with the matter (electrons or ions) is described by a relict radiation factor. This factor enabled us to process the transformed CMB anisotropy spectrum by a Fourier transform and thus calculate a radial distribution function of objects in a reciprocal space. In this way we were able to calculate distances between larger objects of the order $\\sim10^{2}$ [km] and the value for the density of ordinary matter $\\sim9\\times 10^{-23}$ [kg.m$^{-3}$]. A transformation of the anisotropy spectrum of CMB radiation into a simple reciprocal space and appropriate modelling of the transformed CMB spectrum indicated that the internal structure of larger objects may be formed by clusters distant $\\sim$10 [cm], whereas the internal structure of a cluster consisted of particles distant $\\sim$0.3 [nm].

  20. Distortion of the Microwave Blackbody Background Radiation Implied by the Baryon-symmetric Cosmology of Omnes and the Galaxy Formation Theory of Stecker and Puget

    Science.gov (United States)

    Stecker, F. W.; Puget, J. L.

    1973-01-01

    Theories on the evolution of the universe are evaluated. Particular attention was given to Omnes and Stecker and Puget theories. Data cover distortion of the microwave black body background energy distribution at red shifts between 10,000 and 1.000, and black body distortion due to antimatter and annihilation reactions.

  1. ACOUSTIC RADIATION ENERGY AT A VARIATION OF THE COMPOSITE MECHANICAL DESTRUCTION AREA

    Directory of Open Access Journals (Sweden)

    Sergii Filonenko

    2016-06-01

    Full Text Available Purpose: The technological parameters of composite materials machining and also cutting tool state determine deforming and destruction of their surface layers conditions. Change of this conditions results to appearance of miscellaneous defects, loss of quality and produced items reliability. Therefore, optimization, control, diagnosis and monitoring of composite materials machining technological parameters are directed on obtaining the items given quality. For the solution of these problems tasks carry out researches of technological processes with usage of different methods. One of such methods is the acoustic emission method. Methods: The simulation and analysis of acoustic radiation energy parameters is carried out at change of composite material machining depth for prevailing mechanical destruction its surface layer. Results: We showed that to composite material machining the acoustic radiation energy has continuous nature. The ascending of composite material machining depth results to increase of acoustic emission statistical energy parameters. The regularity of acoustic emission energy parameters change are obtained and described. Is showed, that acoustic radiation most sensing parameter is the acoustic emission signals energy average level dispersion. Discussion: The outcomes researches demonstrate regularity influencing of composite material machining depth on acoustic emission energy parameters. Thus the analysis of acoustic emission signals energy average level dispersion can be used at mining methods of diagnostic, monitoring and control of composite materials machining technological parameters.

  2. Solar Radiation Pressure Estimation and Analysis of a GEO Class of High Area-to-Mass Ratio Debris Objects

    Science.gov (United States)

    Kelecy, Tom; Payne, Tim; Thurston, Robin; Stansbery, Gene

    2007-01-01

    A population of deep space objects is thought to be high area-to-mass ratio (AMR) debris having origins from sources in the geosynchronous orbit (GEO) belt. The typical AMR values have been observed to range anywhere from 1's to 10's of m(sup 2)/kg, and hence, higher than average solar radiation pressure effects result in long-term migration of eccentricity (0.1-0.6) and inclination over time. However, the nature of the debris orientation-dependent dynamics also results time-varying solar radiation forces about the average which complicate the short-term orbit determination processing. The orbit determination results are presented for several of these debris objects, and highlight their unique and varied dynamic attributes. Estimation or the solar pressure dynamics over time scales suitable for resolving the shorter term dynamics improves the orbit estimation, and hence, the orbit predictions needed to conduct follow-up observations.

  3. Assessment of temporal trend of radiation dose to the public living in the large area contaminated with radioactive materials after a nuclear power plant accident

    Energy Technology Data Exchange (ETDEWEB)

    Go, A Ra; Kim, Min Jun; Kim, Kwang Pyo [Dept. of Nuclear Engineering, Kyung Hee University, Seoul (Korea, Republic of); Cho, Nam Chan; Seol, Jeung Gun [Radiation Safety Team, Korea Electric Power Corporation Nuclear Fuel, Seoul (Korea, Republic of)

    2015-12-15

    It has been about 5 years since the Fukushima nuclear power plant accident, which contaminated large area with radioactive materials. It is necessary to assess radiation dose to establish evacuation areas and to set decontamination goal for the large contaminated area. In this study, we assessed temporal trend of radiation dose to the public living in the large area contaminated with radioactive materials after the Fukushima nuclear power plant accident. The dose assessment was performed based on Chernobyl model and RESRAD model for two evacuation lift areas, Kawauchi and Naraha. It was reported that deposition densities in the areas were 4.3-96 kBq m{sup -2} for {sup 134}Cs, 1.4-300 kBq m{sup -2} for {sup 137}Cs, respectively. Radiation dose to the residents depended on radioactive cesium concentrations in the soil, ranging 0.11-2.4 mSv y{sup -1} at Kawauchi area and 0.69-1.1 mSv y{sup -1} at Naraha area in July 2014. The difference was less than 5% in radiation doses estimated by two different models. Radiation dose decreased with calendar time and the decreasing slope varied depending on dose assessment models. Based on the Chernobyl dosimetry model, radiation doses decreased with calendar time to about 65% level of the radiation dose in 2014 after 1 year, 11% level after 10 years, and 5.6% level after 30 years. RESRAD dosimetry model more slowly decreased radiation dose with time to about 85% level after 1 year, 40% level after 10 years, and 15% level after 30 years. The decrease of radiation dose can be mainly attributed into radioactive decays and environmental transport of the radioactive cesium. Only environmental transports of radioactive cesium without consideration of radioactive decays decreased radiation dose additionally 43% after 1 year, 72% after 3 years, 80% after 10 years, and 83% after 30 years. Radiation doses estimated with cesium concentration in the soil based on Chernobyl dosimetry model were compared with directly measured radiation doses

  4. Improving radiative transfer processes in snow-covered areas prone to dust loading using a regional climate model

    Science.gov (United States)

    Oaida, C. M.; Xue, Y.; Painter, T. H.; Flanner, M. G.; De Sales, F.

    2011-12-01

    Radiative processes play an important role on both global and regional scales. This study focuses on their effects over snow-covered surfaces, both clean and dust loaded. It is well understood that dust in snow enhances solar radiation absorption, leading to a decrease in snow albedo. However, the quantitative assessment of dust's influence on radiative forcing and runoff timing in mountain snow packs has only been recently investigated. Painter et al. (2007) have shown that snow cover was shortened by 18 to 35 days due to dust radiative forcing in snow in the San Juan Mountains, Colorado, USA. This dust largely originates from the Colorado Plateau with increases of 5-7 fold in the last century and a half due to grazing and agricultural practices. For this study, we employ NCAR's WRF ARW v3.3+ model, which is coupled with a land surface model, Simplified Simple Biosphere version 3 (SSiB3). We first investigate the impact of different atmospheric radiative transfer schemes in WRF3.3+-SSiB3 on the regional climate downscaling. After conducting simulations over North America for the period March through June, we found substantial differences in the downscaling skills with different atmospheric radiative schemes. These differences indicate the uncertainty due to the atmospheric radiative transfer parameterizations. To develop a regional climate model that is capable of realistically simulating radiative forcing on snow covered areas with aerosol loading, we coupled WRF3.3+-SSiB3 with a snow-radiative transfer model, Snow, Ice, and Aerosol Radiative (SNICAR) model. SNICAR considers the effects of snow grain size and aerosol on snow albedo evolution. Snow grain size and growth is important in snow albedo feedbacks, especially when aerosols in snow are considered, because larger snow grains decrease snow albedo, and in the presence of dust, grain growth rates increase, decreasing snow reflectance even further than if the snow was pure. Our previous version of WRF3.3+-SSi

  5. Fuel consumption and fire emissions estimates using Fire Radiative Power, burned area and statistical modelling on the fire event scale

    Science.gov (United States)

    Ruecker, Gernot; Leimbach, David; Guenther, Felix; Barradas, Carol; Hoffmann, Anja

    2016-04-01

    Fire Radiative Power (FRP) retrieved by infrared sensors, such as flown on several polar orbiting and geostationary satellites, has been shown to be proportional to fuel consumption rates in vegetation fires, and hence the total radiative energy released by a fire (Fire Radiative Energy, FRE) is proportional to the total amount of biomass burned. However, due to the sparse temporal coverage of polar orbiting and the coarse spatial resolution of geostationary sensors, it is difficult to estimate fuel consumption for single fire events. Here we explore an approach for estimating FRE through temporal integration of MODIS FRP retrievals over MODIS-derived burned areas. Temporal integration is aided by statistical modelling to estimate missing observations using a generalized additive model (GAM) and taking advantage of additional information such as land cover and a global dataset of the Canadian Fire Weather Index (FWI), as well as diurnal and annual FRP fluctuation patterns. Based on results from study areas located in savannah regions of Southern and Eastern Africa and Brazil, we compare this method to estimates based on simple temporal integration of FRP retrievals over the fire lifetime, and estimate the potential variability of FRP integration results across a range of fire sizes. We compare FRE-based fuel consumption against a database of field experiments in similar landscapes. Results show that for larger fires, this method yields realistic estimates and is more robust when only a small number of observations is available than the simple temporal integration. Finally, we offer an outlook on the integration of data from other satellites, specifically FireBird, S-NPP VIIRS and Sentinel-3, as well as on using higher resolution burned area data sets derived from Landsat and similar sensors.

  6. Soil radioactivity levels and radiation hazard assessment for some populated areas, Cairo, Egypt

    International Nuclear Information System (INIS)

    Determination of the natural radioactivity has been carried out, by means of gamma ray spectrometry system ,on sixty two surface soil samples collected from different localities in Nasr City and Heliopolis for measuring the activity concentrations for 238U, 232Th, and 40K. The evaluation of environmental radioactivity and estimating the current radiation hazards to the population make this study an interesting issue. The output results referred to all these localities indicated that these regions are not hazardous from the environmental point of view.The results of the present study were discussed and compared with internationally recommended values.

  7. In situ quantitative determination of transuranic elements in areas of high-level gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Brodzinski, R.L.; Wogman, N.A.

    1978-01-01

    A technique is described for passive neutron monitoring of transuranic elements. The method provides quantitative determinations of transuranic element concentrations in a variety of field situations where no other measurement method is possible. The technique can measure concentrations of transuranic oxides as low as 8 nCi/cm/sup 3/ and is capable of operating in gamma radiation fields up to megarads per hour. Information on chemical and isotopic composition can also be obtained from the data. Several successful applications of the technique are discussed.

  8. 137Cs radiation burden on children from a highly contaminated area of Belarus

    International Nuclear Information System (INIS)

    The radiation burden from 137Cs sources on 22 children from a small Byelorussian village was studied from 1992 to 1994. Foodstuff, whole body burden and urinary excretion of 137Cs were measured, intake rates, biological half-lives and doses were calculated. The median value for the 137Cs whole body incorporation level was found to be 124 Bq, the biological half life was calculated as 68 d for girls and 50 d for boys. The internal dose caused by 137Cs was found to be negligible in comparison to that from external sources. No deviation from normal values could be shown in simultaneously studied clinico-chemical parameters

  9. Recent progress in the development of large area silica aerogel for use as RICH radiator in the Belle II experiment

    CERN Document Server

    Tabata, Makoto; Kawai, Hideyuki; Nishida, Shohei; Sumiyoshi, Takayuki

    2014-01-01

    We report recent progress in the development of large-area hydrophobic silica aerogels for use as radiators in the aerogel-based ring-imaging Cherenkov (A-RICH) counter to be installed in the forward end cap of the Belle II detector, which is currently being upgraded at the High Energy Accelerator Research Organization (KEK), Japan. The production of approximately 450 aerogel tiles with refractive indices of either 1.045 or 1.055 was completed in May, 2014, and the tiles are now undergoing optical characterization. Installation of the aerogels was tested by installing them into a partial mock-up of the support structure.

  10. Estimation of a "radiatively correct" black carbon specific absorption during the Mexico City Metropolitan Area (MCMA) 2003 field campaign

    OpenAIRE

    Barnard, J. C.; E. I. Kassianov; Ackerman, T. P.; K. Johnson; Zuberi, B.; L. T. Molina; M. J. Molina

    2007-01-01

    During the Mexico City Metropolitan Area (MCMA) field campaign of 2003, measurements of the shortwave radiation field allowed the inference of the black carbon (BC) specific absorption, αλ, defined as the monochromatic absorption cross section per unit mass (with units of m2/g). The averaged values of αλ derived from the method here are either 8.9 m2/g or 8.2 m2/g at 500 nm, depending upon the physical and optical parameters assumed for BC. These re...

  11. Estimation of a "radiatively correct" black carbon specific absorption during the Mexico City Metropolitan Area (MCMA) 2003 field campaign

    OpenAIRE

    Barnard, J. C.; E. I. Kassianov; Ackerman, T. P.; K. Johnson; Zuberi, B.; L. T. Molina; M. J. Molina

    2007-01-01

    During the Mexico City Metropolitan Area (MCMA) field campaign of 2003, measurements of the shortwave radiation field allowed the inference of the black carbon (BC) specific absorption, αλ, defined as the monochromatic absorption cross section per unit mass (with units of m2/g). The averaged values of αλ derived from the method here are either 8.9 m2/g or 8.2 m2/g at 500 nm, depending upon the physical and optical parameters assumed for BC. These results are reasonab...

  12. Off-site environmental monitoring report: Radiation monitoring around United States Nuclear Test areas, Calendar year 1986

    International Nuclear Information System (INIS)

    The principal activity at the NTS is testing of nuclear devices, though other related projects are also conducted. The principal activities of the Off-Site Radiological Safety Program are routine environmental monitoring for radioactive materials in various media and for radiation in areas which may be affected by nuclear tests; and protective actions in support of the nuclear testing program. These are conducted to document compliance with standards, to identify trends, and to provide information to the public. 28 refs., 37 figs., 30 tabs

  13. Estimation of aerosol radiative forcing over an aged-background aerosol feature during advection and non-advection events using a ground-based data obtained from a Prede Skyradiometer observation

    Science.gov (United States)

    Ningombam, Shantikumar S.; Bagare, S. P.; Khatri, P.; Sohn, B. J.; Song, H.-J.

    2015-10-01

    Estimation of aerosol radiative forcing (ARF) was performed using a radiative transfer model (Rstar6b) along with physical and optical parameters of aerosols obtained from sky radiometer observation over Indian Astronomical Observatory (IAO), Hanle, Ladakh, during 2008-2010 from dust, anthropogenic, and aged background observing conditions. ARF was estimated at the top of the atmosphere (TOA), in the atmosphere, and at the surface during the three observing conditions. During dust and anthropogenic events, average aerosol optical depth (AOD at 500 nm) went up to 0.24 from the aged background observing condition 0.04. Such enhancement of AOD is associated by the combination of desert-dust and anthropogenic aerosols transported from distant sources as noticed from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). Such three types of aerosols are also identified from the observed properties of single scattering albedo (SSA), aerosol asymmetry (AS) parameter, and aerosol size distribution. The estimated ARFs at TOA, at the surface, and in atmosphere are - 3.73, - 6.82, and 3.40 Wm- 2, respectively during the dust advection period. On the contrary, the respective ARFs during the aged background observing condition are - 1.50, - 2.22, and 0.70 Wm- 2, respectively. A significant difference of spectral AOD is observed during dust, anthropogenic, and aged background observing conditions. Ångström exponent (AE) decreases from 1.05 in the aged background observing condition to 0.40 in the dust event. A significant difference of coarse-fine mode volume distribution is also observed between the dust and the anthropogenic cases. Further, the study reveals high aerosols induced during the dust and the anthropogenic episodes caused warming at atmosphere and cooling at surface which collectively may affect the local atmospheric circulation.

  14. Calibration procedures of area monitors in terms of the Ambient Dose Equivalent H*(10), for gamma, x-ray radiation fields

    International Nuclear Information System (INIS)

    In the present thesis procedures for calibrating portable survey meters in terms of the new ICRU quantities H*(10) ambient dose equivalent are discussed. Also the remendations of International Comission on Radiation Protection in their report ICRP 60 that inludes the operational magnitudes that the International Comission of Radiation Units proposed for calibrating area monitors

  15. Vapor transport deposition of large-area polycrystalline CdTe for radiation image sensor application

    International Nuclear Information System (INIS)

    Vapor transport deposition (VTD) process delivers saturated vapor to substrate, resulting in high-throughput and scalable process. In addition, VTD can maintain lower substrate temperature than close-spaced sublimation (CSS). The motivation of this work is to adopt several advantages of VTD for radiation image sensor application. Polycrystalline CdTe films were obtained on 300 mm x 300 mm indium tin oxide (ITO) coated glass. The polycrystalline CdTe film has columnar structure with average grain size of 3 μm ∝ 9 μm, which can be controlled by changing the substrate temperature. In order to analyze electrical and X-ray characteristics, ITO-CdTe-Al sandwich structured device was fabricated. Effective resistivity of the polycrystalline CdTe film was ∝1.4 x 109Ωcm. The device was operated under hole-collection mode. The responsivity and the μτ product estimated to be 6.8 μC/cm2R and 5.5 x 10-7 cm2/V. The VTD can be a process of choice for monolithic integration of CdTe thick film for radiation image sensor and CMOS/TFT circuitry. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Composition, size distribution, optical properties, and radiative effects of laboratory-resuspended PM10 from geological dust of the Rome area, by electron microscopy and radiative transfer modelling

    Science.gov (United States)

    Pietrodangelo, A.; Salzano, R.; Bassani, C.; Pareti, S.; Perrino, C.

    2015-11-01

    In this work, new information has been gained on the laboratory-resuspended PM10 fraction from geological topsoil and outcropped rocks representative of the Rome area (Latium). Mineralogical composition, size distribution, optical properties and the surface radiative forcing efficiency (RFE) of dust types representing the compositional end members of this geological area have been addressed. A multi-disciplinary approach was used, based on chamber resuspension of raw materials and sampling of the PM10 fraction, to simulate field sampling at dust source, scanning electron microscopy/X-ray energy-dispersive microanalysis (SEM XEDS) of individual mineral particles, X-ray diffraction (XRD) analysis of bulk dust samples, building of number and volume size distribution (SD) from microanalysis data of mineral particles and fitting to a log-normal curve, and radiative transfer modelling (RTM) to retrieve optical properties and radiative effects of the compositional end-member dust samples. The mineralogical composition of Rome lithogenic PM10 varies between an end-member dominated by silicate minerals (from volcanics lithotypes), and one mostly composed of calcite (from travertine or limestones). Lithogenic PM10 with intermediate composition derives mainly from siliciclastic rocks or marlstones. Size and mineral species of PM10 particles of silicate-dominated dust types are tuned mainly by rock weathering and, to lesser extent, by debris formation or crystallization; chemical precipitation of CaCO3 plays a major role in calcite-dominated types. These differences are reflected in the diversity of volume distributions, either within dust types or mineral species. Differences are also observed between volume distributions of calcite from travertine (natural source; SD unimodal at 5 μm a.d.) and from road dust (anthropic source; SD bimodal at 3.8 and 1.8 μm a.d.). The volcanics and travertine dusts differently affect the single scattering albedo (SSA) and the asymmetry

  17. MODIS/COMBINED MCD15A2 Leaf Area Index - Fraction of Photosynthetically Active Radiation 8-Day L4 Global 1km

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The level-4 MODIS global Leaf Area Index (LAI) and Fraction of Photosynthetically Active Radiation (FPAR) product is composited every 8 days at 1-kilometer...

  18. MODIS/TERRA MOD15A2H Leaf Area Index - Fraction of Photosynthetically Active Radiation 8-Day L4 Global 500 m Version 6

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The level-4 MODIS global Leaf Area Index (LAI) and Fraction of Photosynthetically Active Radiation (FPAR) product is composited every 8 days at 500-meter...

  19. MODIS/TERRA MOD15A2 Leaf Area Index - Fraction of Photosynthetically Active Radiation 8-Day L4 Global 1km

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The level-4 MODIS global Leaf Area Index (LAI) and Fraction of Photosynthetically Active Radiation (FPAR) product is composited every 8 days at 1-kilometer...

  20. MODIS/COMBINED MCD15A3 Leaf Area Index - Fraction of Photosynthetically Active Radiation 4-Day L4 Global1km

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The level-4 MODIS global Leaf Area Index (LAI) and Fraction of Photosynthetically Active Radiation (FPAR) product is composited every 8 days at 1-kilometer...

  1. MODIS/AQUA MYD15A2H Leaf Area Index - Fraction of Photosynthetically Active Radiation 8-Day L4 Global 500 m Version 6

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The level-4 MODIS global Leaf Area Index (LAI) and Fraction of Photosynthetically Active Radiation (FPAR) product is composited every 8 days at 500-meter...

  2. MODIS/COMBINED MCD15A3H Leaf Area Index - Fraction of Photosynthetically Active Radiation 4-Day L4 Global 500 m Version 6

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The level-4 MODIS global Leaf Area Index (LAI) and Fraction of Photosynthetically Active Radiation (FPAR) product is composited every 8 days at 500-meter...

  3. MODIS/COMBINED MCD15A2H Leaf Area Index - Fraction of Photosynthetically Active Radiation 8-Day L4 Global 500 m Version 6

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The level-4 MODIS global Leaf Area Index (LAI) and Fraction of Photosynthetically Active Radiation (FPAR) product is composited every 8 days at 500-meter...

  4. Effects of dose and of partial body ionizing radiation on taste aversion learning in rats with lesions of the area postrema

    International Nuclear Information System (INIS)

    The effect of area postrema lesions on the acquisition of a conditioned taste aversion following partial body exposure to ionizing radiation was investigated in rats exposed to head-only irradiation at 100, 200 and 300 rad or to body-only irradiation at 100 and 200 rad. Following head-only irradiation area postrema lesions produced a significant attenuation of the radiation-induced taste aversion at all dose levels, although the rats still showed a significant reduction in sucrose preference. Following body-only exposure, area postrema lesions completely disrupted the acquisition of the conditioned taste aversion. The results are interpreted as indicating that: (a) the acquisition of a conditioned taste aversion following body-only exposure is mediated by the area postrema; and (b) taste aversion learning following radiation exposure to the head-only is mediated by both the area postrema and a mechanism which is independent of the area postrema

  5. Estimation of a "radiatively correct" black carbon specific absorption during the Mexico City Metropolitan Area (MCMA 2003 field campaign

    Directory of Open Access Journals (Sweden)

    J. C. Barnard

    2007-01-01

    Full Text Available During the Mexico City Metropolitan Area (MCMA field campaign of 2003, measurements of the shortwave radiation field allowed the inference of the black carbon (BC specific absorption, αλ, defined as the monochromatic absorption cross section per unit mass (with units of m2/g. The averaged values of αλ derived from the method here are either 8.9 m2/g or 8.2 m2/g at 500 nm, depending upon the physical and optical parameters assumed for BC. These results are reasonably consistent with those of Schuster et al. (2005, 9.5 m2/g, and Baumgartner et al. (2002, 7.0 m2/g, both measured at 550 nm. The αλ values reported in this paper should only be considered effective, "radiatively correct" values because when used in radiative transfer calculations the calculated irradiances match the measured irradiances at 500 nm. The specific absorption so defined can assume a wide range of values, depending upon: (1 the assumptions made prior to the retrieval (e.g., shell/core aerosol configuration, and (2 values chosen for BC density and refractive index. The range of possible values is large, corresponding to a "worst case" uncertainty of about ±70%, assuming that all errors are additive and of the same sign so that no error cancellation occurs.

  6. Offsite environmental monitoring report. Radiation monitoring around United States nuclear test areas, calendar year 1981

    International Nuclear Information System (INIS)

    This report, prepared in accordance with the guidelines in DOE/E-0023 (DOE 1981), covers the program activities conducted around Nevada Test Site (NTS) for calendar year 1981. It contains descriptions of pertinent features of the NTS and its environs, summaries of the dosimetry and sampling methods, analytical procedures, and the analytical results from environmental measurements. Where applicable, dosimetry and sampling data are compared to appropriate guides for external and internal exposures of humans to ionizing radiation. The monitoring networks detected no radioactivity in the various media which could be attributed to US nuclear testing. Small amounts of fission products were detected in air samples as a result of the People's Republic of China nuclear test and atmospheric krypton-85 increased, following the trend beginning in 1960, due to increased use of nuclear technology. Strontium-90 in milk and cesium-137 in meat samples continued the slow decline as observed for the last several years

  7. Facility for low-dose digital scanning of a large-area image of ionizing radiation

    International Nuclear Information System (INIS)

    The facility scans the unreduced X-ray image by means of moving line sensors which work in parallel. The length of the sensors is much smaller than the width of the image. The facility comprises about 20 identical modules, owing to which the output of the serial manufacture can be increased, and CCD-based line sensors can be employed which are very sensitive and inexpensive. The X-ray image can be taken at the virtually lowest exposure possible, and owing to the parallelization of the scanning process, the scanning rate can be increased considerably as compared with the existing facilities. The facility consists of an ionizing radiation source against which are positioned a movable diaphragm fitted with slits and a movable support plate carrying the line sensors. The sensors make up the line detector whose length is equal to that of the image scanned, synchronously movable with the movable slit diaphragm. (M.D.). 3 figs

  8. Use of Radiation Absorbing Materials for Clearing Snow in Mountainous Areas

    Directory of Open Access Journals (Sweden)

    H. D. Sharma

    1972-07-01

    Full Text Available A comparative study of melting of snow by spreading different materials such as charcoal power, boiler ash, saw dust and common salt etc. On its surface under exposure to natural solar radiation has been made. The observations were carried out at Gulmarg at a height of about 9,000 ft. above sea level in the months of January, February and March 1965. It was observed that with the help of boiler ash, the melting rate of snow was increased to about 4 in the half inches per day which is about twice the rate without boiler ash. This material therefore seems to be very much suited to snow clearing operations in the mountain terrain.

  9. Radiation damages due to the Chernobyl accident. The present situations in the exposed area

    International Nuclear Information System (INIS)

    Upon the time of the 10th year after the Chernobyl accident, the present situations of the exposed area in the old USSR were described here based on the author's some experiences at visiting there from 1990 in addition to the evidences obtained from the long lasting studies in Hiroshima. Especially, the influences by the accident on the occurrences of infantile thyroid carcinoma, congenital abnormalities (teratogenesis) and other abnormalities were discussed. Infantile thyroid carcinoma is a rare disease in the world, however, as many as 40 cases have developed in Belarus by Apr. 1991. The author also confirmed the frequent developments of infantile thyroid carcinoma following the accident in other areas exposed to high level isotopes and pointed the pathogenic possibility of 131I. This shows that the nuclide may play a role as an initiation factor in the mechanism of its carcinogenesis. In Minsk Genetic Disease Institute, various data on congenital abnormalities have been collected from 1970 by establishment of their monitoring system. The incidences of congenital abnormalities for 30,000 cases in the postmortem data were compared between the high-level exposed area and no or low-level, leading to the conclusion that the teratogenic rate in the high-level exposed area rapidly increased during 1-2 years after the accident. (M.N.)

  10. Communication on radiation risk as an area of conflict between radiological, sociological and perceptional issues

    International Nuclear Information System (INIS)

    Risk communication in radiation protection must not be considered as a single discipline, but is based upon an effective interaction of different scientific fields. This implies that radiological and sociological issues as well as risk perception are to be taken into account. However, communication is not straightforward, as the fields have different objectives, are different in terminology, apply different approaches to solve problems, and are using different languages. Issues to be addressed in this paper are among others: possible meanings and definitions of the term 'risk', handling of uncertainty and variability of parameters as risk factors, importance of doses delivered in the far future, reasonable application of the dose commitment concept, and perception of small numbers. Other issues are sociological issues as interests of stakeholders and involved parties, importance of public opinion, media and cultural prototypes, bias in different groups of advocate. As communication will become effective only if the different contributing parties adjust their way of thinking and their language to the requirements of others without modification of their knowledge, guidance for interaction is important. The paper will review possible approaches suitable for better communication. (authors)

  11. Communication on radiation risk as an area of conflict between radiological, sociological and perceptional issues

    Energy Technology Data Exchange (ETDEWEB)

    Tschurlovits, M.; Taghizadegan, R. [University of Technology Vienna, Atominstitute of Austrian Universities, Vienna (Austria)

    2006-07-01

    Risk communication in radiation protection must not be considered as a single discipline, but is based upon an effective interaction of different scientific fields. This implies that radiological and sociological issues as well as risk perception are to be taken into account. However, communication is not straightforward, as the fields have different objectives, are different in terminology, apply different approaches to solve problems, and are using different languages. Issues to be addressed in this paper are among others: possible meanings and definitions of the term 'risk', handling of uncertainty and variability of parameters as risk factors, importance of doses delivered in the far future, reasonable application of the dose commitment concept, and perception of small numbers. Other issues are sociological issues as interests of stakeholders and involved parties, importance of public opinion, media and cultural prototypes, bias in different groups of advocate. As communication will become effective only if the different contributing parties adjust their way of thinking and their language to the requirements of others without modification of their knowledge, guidance for interaction is important. The paper will review possible approaches suitable for better communication. (authors)

  12. Composition, size distribution, optical properties and radiative effects of re-suspended local mineral dust of Rome area by individual-particle microanalysis and radiative transfer modelling

    Directory of Open Access Journals (Sweden)

    A. Pietrodangelo

    2015-05-01

    Full Text Available New information on the PM10 mineral dust from site-specific (Rome area, Latium outcropped rocks, and on the microphysics, optical properties and radiative effects of mineral dust at local level were gained in this work. A multi-disciplinary approach was used, based on individual-particle scanning electron microscopy with X-ray energy-dispersive microanalysis (SEM XEDS, X-ray diffraction (XRD analysis of dust, size distribution of mineral particles, and radiative transfer modelling (RTM.The mineral composition of Rome lithogenic PM10 varies between an end-member dominated by silicate minerals and one exclusively composed of calcite. The first is obtained from volcanic lithotypes, the second from travertine or limestones; lithogenic PM10 with intermediate composition derives mainly from siliciclastic rocks or marlstones of Rome area. Size and mineral species of PM10 particles of silicate-dominated dust types are tuned mainly by weathering and, to lesser extent, by debris formation or crystallization; chemical precipitation of CaCO3 plays a major role in calcite-dominated types. These differences are evidenced by the diversity of volume distributions, within either dust types, or mineral species. Further differences are observed between volume distributions of calcite from travertine (natural source and from road dust (anthropic source, specifically on the width, shape and enrichment of the fine fraction (unimodal at 5 μm a.d. for travertine, bimodal at 3.8 and 1.8 μm a.d. for road dust. Log-normal probability density functions of volcanics and travertine dusts affect differently the single scattering albedo (SSA and the asymmetry parameter (g in the VISible and Near Infrared (NIR regions, depending also on the absorbing/non-absorbing character of volcanics and travertine, respectively. The downward component of the BOA solar irradiance simulated by RTM for a volcanics-rich or travertine-rich atmosphere shows that volcanics contribution to the

  13. Composition, size distribution, optical properties and radiative effects of re-suspended local mineral dust of Rome area by individual-particle microanalysis and radiative transfer modelling

    Science.gov (United States)

    Pietrodangelo, A.; Salzano, R.; Bassani, C.; Pareti, S.; Perrino, C.

    2015-05-01

    New information on the PM10 mineral dust from site-specific (Rome area, Latium) outcropped rocks, and on the microphysics, optical properties and radiative effects of mineral dust at local level were gained in this work. A multi-disciplinary approach was used, based on individual-particle scanning electron microscopy with X-ray energy-dispersive microanalysis (SEM XEDS), X-ray diffraction (XRD) analysis of dust, size distribution of mineral particles, and radiative transfer modelling (RTM).The mineral composition of Rome lithogenic PM10 varies between an end-member dominated by silicate minerals and one exclusively composed of calcite. The first is obtained from volcanic lithotypes, the second from travertine or limestones; lithogenic PM10 with intermediate composition derives mainly from siliciclastic rocks or marlstones of Rome area. Size and mineral species of PM10 particles of silicate-dominated dust types are tuned mainly by weathering and, to lesser extent, by debris formation or crystallization; chemical precipitation of CaCO3 plays a major role in calcite-dominated types. These differences are evidenced by the diversity of volume distributions, within either dust types, or mineral species. Further differences are observed between volume distributions of calcite from travertine (natural source) and from road dust (anthropic source), specifically on the width, shape and enrichment of the fine fraction (unimodal at 5 μm a.d. for travertine, bimodal at 3.8 and 1.8 μm a.d. for road dust). Log-normal probability density functions of volcanics and travertine dusts affect differently the single scattering albedo (SSA) and the asymmetry parameter (g) in the VISible and Near Infrared (NIR) regions, depending also on the absorbing/non-absorbing character of volcanics and travertine, respectively. The downward component of the BOA solar irradiance simulated by RTM for a volcanics-rich or travertine-rich atmosphere shows that volcanics contribution to the solar

  14. Application of SOI Area Detectors to Synchrotron Radiation X-ray Experiments

    CERN Document Server

    Hashimoto, Ryo; Kumai, Reiji; Kishimoto, Shunji

    2015-01-01

    Application of new detectors using Silicon-On-Insulator (SOI) technology has been started in the Photon Factory, KEK. This project has two purposes. The first purpose is to develop a pulse-counting-type X-ray detector which can be used in synchrotron soft X-ray experiments. The second one is to apply the SOI area detector developed by RIKEN, SOPHIAS, to X-ray diffraction and small-angle scattering experiments in Photon Factory. In this paper, we introduce the current status of our project.

  15. Product kerma in the air-area and radiation dose in dental radiodiagnosis

    International Nuclear Information System (INIS)

    The main purpose of patient dosimetry in diagnostic radiology is to determine dosimetric quantities for the establishment and use of reference levels and comparative risk assessment. In recent publications the use of the air kerma-area product, PKA, has been suggested in dental radiology, as this quantity is more closely related to risk. The aim of this study was to perform a preliminary survey of PKA and effective dose in different types of dental examinations. The future perspective is a large-scale survey for the establishment and use of diagnostic reference levels in dentistry in Brazil. (author)

  16. Characterizing the natural radiation levels throughout the main geological units of Sabkhat al Jabboul area, northern Syria

    International Nuclear Information System (INIS)

    The concentrations of equivalent eU, eTh, and K% were determined together with soil gas radon values and carborne gamma-ray survey in order to define the natural radioactivity levels throughout main geological units of Sabkhat al Jabboul region. Forty five soil and rock samples were collected from various lithofacies in each geological unit, and analyzed by γ-ray spectrometric technique for determining the concentration values of major radioelements. Such radiometric data could be used to differentiate between various lithologies of the investigated rocks. Although no distinct radioactive anomalies were found in the area, the radiometric profiles showed some minor variations with slightly higher values than the normal level. Despite the low radioactivity and the lack of rocks diversity in the surveyed area, it was possible to classify some certain rock types based on their radiometric response. The relationships between eU, eTh and their ratios were discussed for the Quaternary, Neogene and Paleogene formations, in order to evaluate the degree of uranium distribution and remobilization. The overall results of this radiometric survey were generally low, and lying within the range of the normal background levels in Syrian. - Highlights: • Radiometric and geochemical survey was performed in Sabkhat al Jabboul basin. • No anomalous radioactive values were recorded throughout the concerned region. • The results were generally low and lying within the normal background level of Syria

  17. Biosorption of cadmium by Brevundimonas sp. ZF12 strain, a novel biosorbent isolated from hot-spring waters in high background radiation areas.

    Science.gov (United States)

    Masoudzadeh, Nasrin; Zakeri, Fardideh; Lotfabad, Tayebe bagheri; Sharafi, Hakimeh; Masoomi, Fatemeh; Zahiri, Hoseein Shahbani; Ahmadian, Gholamreza; Noghabi, Kambiz Akbari

    2011-12-15

    The aim of this study is to screen cadmium biosorbing bacterial strains isolated from soils and hot-springs containing high concentrations of radium ((226)Ra) in Ramsar using a batch system. Brevundimonas sp. ZF12 strain isolated from the water with high (226)Ra content caused 50% removal of cadmium at a concentration level of 250 ppm. The biosorption equilibrium data are fitted well by the Langmuir adsorption isotherm and kinetic studies indicated that the biosorption follows pseudo second-order model. The effect of different physico-chemical parameters like biomass concentration, pH, cadmium concentration, temperature and contact time on cadmium sorption was also investigated using FTIR, SEM and XRD analytical techniques. A high desorption efficiency (above 90%) was obtained using a pH range of 2.0-4.0. Reusability of the biomass was examined under consecutive biosorption-desorption cycles repeated thrice. In conclusion, Brevundimonas sp. ZF12 is proposed as an excellent cadmium biosorbent that may have important applications in Cd removal from wastewaters.

  18. Discussion on Deep Tectonic Background of Moderately Strong Earthquake in Anhui Province and Its Neighboring Areas Using Results of Seismic Tomography

    Institute of Scientific and Technical Information of China (English)

    Zhang Jie; Shen Xiaoqi; Wang Xingzhou; Shen Yelong

    2006-01-01

    Using the latest results of seismic tomography, we studied the deep tectonic settings of the moderate and strong earthquakes in Anhui Province and its neighboring areas (28°~ 39°N,112°~ 124°E). The results are as follows: (1) There exists a certain correlation between the location of moderate-strong earthquake, the geologic structure of the surface and the partitioning of active tectonic elements with the upper-crust velocity structure. Most earthquakes recording M ≥ 6.0 occur in high-velocity zones or in the transitional areas between high-velocity and low-velocity zones in the upper crust. Seismicity in the low-velocity zone has a lesser impact. Earthquakes occuring in the high-velocity zone are distributed mainly in the velocity variation area. The boundary belts and the interior of the North China plain fault block are the main active sites of moderate-strong earthquakes. Beneath the fault basins in the western and northern sides of the block, the upper crust is characterized by a wide discontinuous distribution in the low-velocity zone, and in the transition zone from the low- to higl velocities, the moderate strong seismicity shows a zonal distribution where active faults are developed. The NW-extension Zhoukou-Hefei-Xuancheng low-velocity zone separates the high-velocity zones of Dabieshan Mountains and west Shandong-Anhui, and moderate-strong earthquakes on its northern side bordering the high-velocity zones are relatively frequent. This low-velocity zone is probably an important and deeply structured boundary between the North China and the South China tectonic provinces. (2) The frequent moderate-strong earthquake recorded in the past and the recent small earthquake activities in the Huoshan-Lu' an area are the result of a low-velocity zone in the middle crust beneath the central part of Dabieshan and the two sets of deep faults that cut through the crust. (3) In terms of deep structures, the distribution of moderate-strong earthquake in Anhui

  19. A search for a keV signature of radiatively decaying dark matter with Suzaku XIS observations of the X-ray diffuse background

    Science.gov (United States)

    Sekiya, Norio; Yamasaki, Noriko Y.; Mitsuda, Kazuhisa

    2016-06-01

    We performed the deepest search for an X-ray emission line at between 0.5 and 7 keV from non-baryonic dark matter by the Suzaku XIS. Dark matter associated with the Milky Way was selected as the target to obtain the best signal-to-noise ratio. From the Suzaku archive, we selected 187 data sets of blank-sky regions that were dominated by the X-ray diffuse background. The data sets were from 2005 to 2013. The instrumental responses were adjusted by multiple calibration data sets of the Crab Nebula. We also improved the technique of subtracting lines of instrumental origin. These energy spectra were well described by X-ray emission due to charge exchange around the Solar System, hot plasma in and around the Milky Way, and the superposition of extra-galactic point sources. A signal of a narrow emission-line was searched for, and the significance of detection was evaluated in consideration of the blind search method (the Look-elsewhere Effect). Our results exhibited no significant detection of an emission line feature from dark matter. The 3 σ upper limit for the emission line intensity between 1 and 7 keV was ˜ 10-2 photons cm-2 s-1 sr-1, or ˜ 5 × 10-4 photons cm-2 s-1 sr-1 per M⊙ pc-2, assuming a dark matter distribution with the Galactic rotation curve. The parameters of sterile neutrinos as candidates of dark-matter were also constrained.

  20. Environmental geochemistry of shale-hosted Ag-Pb-Zn massive sulfide deposits in northwest Alaska: Natural background concentrations of metals in water from mineralized areas

    Science.gov (United States)

    Kelley, K.D.; Taylor, C.D.

    1997-01-01

    Red Dog, Lik and Drenchwater are shale-hosted stratiform Ag-Pb-Zn massive sulfide deposits in the northwestern Brooks Range. Natural background concentrations of metals in waters from the undisturbed (unmined) Drenchwater prospect and Lik deposit were compared to pre-mining baseline studies conducted at Red Dog. The primary factors affecting water chemistry are the extent of exposure of the deposits, the grade of mineralization, the presence of carbonate reeks in the section, and the proportion of Fe-sulfide in the ore. Surface water samples from the Drenchwater prospect, which has pyrite-dominant mineralization exposed in outcrop, have pH values as low as 2.8 and high dissolved concentrations of metals including as much as 95 mg 1-1 Al, 270 mg 1-1 Fe, 8 ??1-1 Cd, 10 ??1-1 Pb, and 2600 ??1-1 Zn, with As up to 26 ??g1-1. Surface waters from the Red Dog deposit prior to mining were also acidic and metal-rich, however, dissolved metal concentrations in Red Dog waters were many times greater. The higher metal concentrations in Red Dog waters reflect the high Zn grades and the abundant sphalerite, pyrite, and galena that were present in outcrop prior to mining. In contrast, despite significant mineralization at the Lik deposit, carbonate rocks in the section buffer the system, resulting in less acidic, mostly near-neutral pH values with low concentrations of most metals except Zn.

  1. Radiation doses to frogs inhabiting a wetland ecosystem in an area of Sweden contaminated with 137Cs

    International Nuclear Information System (INIS)

    Internal and external radiation doses to frogs living in a wetland ecosystem contaminated with 137Cs were estimated. The external doses were calculated from measured concentrations of 137Cs in soil and in water taking into account changes in the habitat during the frogs' life cycle. The internal dose was estimated from measured concentrations of 137Cs in living frogs (Rana arvalis) using a whole-body counter. The average inventory of 137Cs in the soil was approximately 1000 kBq/m2 of which 86-99 % was found in the top 12 cm. The concentrations of 137Cs in frogs varied between 560 and 3450 Bq/kg ww. The estimated external dose rate was between 21 and 160 mGy/y, while the internal dose of beta and gamma was only between 1 and 6.2 mGy/y. The estimated total dose rate to frogs from 137Cs was below the expected safe level for terrestrial populations but close to the critical dose rate for amphibians suggested in the literature. Therefore, the radiation risk to frogs from radiocaesium in the study area may be one more stressor for an endangered group of animals in this ecosystem. (author)

  2. Off-site environmental monitoring report: radiation monitoring around United States nuclear test areas, calendar year 1984

    International Nuclear Information System (INIS)

    This report covers the routine radiation monitoring activities conducted by the Environmental Monitoring Systems Laboratory-Las Vegas in areas which may be affected by nuclear testing programs of the Department of Energy. This monitoring is conducted to document compliance with standards, to identify trends in environmental radiation, and to provide such information to the public. It summarizes these activities for calendar year 1984. No radioactivity attributable to NTS activities was detectable offsite by the monitoring networks. Using recorded wind data and Pasquill stability categories, atmospheric dispersion calculations based on reported radionuclides releases yield an estimated dose of 1 x 10-3 person-rem to the population within 80 km of the Nevada Test Site during 1983. World-wide fallout of Kr-85, Sr-90, Cs-137, and Pu-239 detected by the monitoring networks would cause maximum exposure to an individual of less than 0.6 mrem per year. Plutonium in air was still detectable along with krypton-85, which continued its gradual increase, as has been reported previously. Cesium and strontium in air were near their detection limits. An occasional net exposure to offsite residents has been detected by the TLD network. On investigation, the cause of such net exposures has been due to personal habits or occupational activities, not to NTS activities. 32 refs., 36 figs., 27 tabs

  3. ASSESSMENT OF SOCIAL AND PSYCHOLOGICAL CONSEQUENCES OF RADIATION DANGER EXPERIENCE AMONG DIFFERENT AGE GROUPS OF THE POPULATION FROM CONTAMINATED AREAS OF RUSSIA

    Directory of Open Access Journals (Sweden)

    T. A. Marchenko

    2012-01-01

    Full Text Available The results of evaluation of social-psychological consequences of radiation danger experience among different age groups of the population from contaminated areas of Russia (Oryol, Kaluga, Bryansk, Tula areas among whom the unfavorable emotional and personal changes were registered due to subjective features of perception of radiation threat have been represented (“risk” group. Experimental sample of the research consisted of 1 544 people from Russia. One of the main results of this research is establishment of the fact that adverse emotional and personal changes in connection with subjective features of perception of radiation threat were revealed for 53,9% of respondents of advanced age and more than 20% of respondents of middle and young age from contaminated areas of Russia. Among the respondents from contaminated areas of Belarus, about a third surveyed from each age group get to “risk” group.

  4. The latitudinal distributions of sunspot areas and magnetic fields and their correlation with the background solar magnetic field in the cycle 23

    Science.gov (United States)

    Zharkov, S. I.; Gavryuseva, E. V.; Zharkova, V. V.

    The quasi 3D latitudinal distributions (butterfly diagrams) of sunspot areas and magnetic fields obtained within the whole μ-hemispheres in longitudes from the Solar Feature Catalogues for 9 years (1996-2005) of the cycle 23 are correlated with those of the low-resolution solar magnetic fields (SMF) obtained from Wilcox Solar Observatory. During the whole period of observations the sunspot areas reveal a strong positive correlation with SMF appearing at zero timelag and repeating at the 2-2.5 year time lags after or before the cycle start. The high positive correlation coefficients are also distributed into the four zones reflecting the sunspot migration directions: the two pre-polar zones above ±45° with the positive correlation increasing towards the poles (the sunspot migration towards the poles) and the two pre-equatorial zones from -40° to +40° (the 'royal zone') with the positive correlation increasing toward the equator as seen in the butterfly diagrams. This correlation suggests a modulating effect of the symmetric component of SMF on the magnitude of magnetic field in flux tubes emerging as sunspots. The symmetric SMF components have the same signs in each hemisphere and they are changed to opposite over the period 2-2.5 year. Then, if the signs of the symmetric SMF coincides with the leading polarity signs in a one hemisphere and opposite in the other one, the flux tube emergence (and sunspot appearance) is supported by SMF in the first one and suppressed in the other. While in 2.5 years when the SMF sign is changed to the opposite, the flux emergence is supported in the other hemisphere but suppressed in the first one.

  5. Calibrating an optical scanner for quality assurance of large area radiation detectors

    Science.gov (United States)

    Karadzhinova, A.; Hildén, T.; Berdova, M.; Lauhakangas, R.; Heino, J.; Tuominen, E.; Franssila, S.; Hæggström, E.; Kassamakov, I.

    2014-11-01

    A gas electron multiplier (GEM) is a particle detector used in high-energy physics. Its main component is a thin copper-polymer-copper sandwich that carries Ø =70  ±  5 µm holes. Quality assurance (QA) is needed to guarantee both long operating life and reading fidelity of the GEM. Absence of layer defects and conformity of the holes to specifications is important. Both hole size and shape influence the detector’s gas multiplication factor and hence affect the collected data. For the scanner the required lateral measurement tolerance is ± 5 µm. We calibrated a high aspect ratio optical scanning system (OSS) to allow ensuring the quality of large GEM foils. For the calibration we microfabricated transfer standards, which were imaged with the OSS and which were compared to corresponding scanning electron microscopy (SEM) images. The calibration fulfilled the ISO/IEC 17025 and UKAS M3003 requirements: the calibration factor was 1.01  ±  0.01, determined at 95% confidence level across a 950  ×  950 mm2 area. The proposed large-scale scanning technique can potentially be valuable in other microfabricated products too.

  6. Radiation exposure assessment by using coral reefs in red sea Port Sudan area

    International Nuclear Information System (INIS)

    In this study coral reef samples have been collected from different locations of the red sea in Port Sudan area, which is located in eastern Sudan. Positions have been determined by geographical positioning system (GPS). Radioactivity has been measured using the gamma spectroscopy ( sodium iodide detector). The following radioactive elements have been analyzed: Uranium-238, Thorium-232, Cesium-137 and Potassium-40. Two types of reefs have been identified ( A: Fringing and B: Barrier). The average concentration were: 0.62±0.45, 3.23±1.64, 0.91±0.20, 98.42±30.98 Bq/Kg, respectively. The average concentration for type B samples have been calculated and found that the average concentration were: 0.77±0.23, 2.94±1.83, 0±0, 101.50±12.31 Bq/Kg, respectively. These values are much lower than the global average of these isotopes. as contained in UNSCEAR where the concentrations for type A ranging from: 0-1.54, 0-4.44, 0-0.73, 10.16- 135.47 respectively. The concentrations for type B ranging from: 0-0.96, 0-4.40, 0.0, 87.96-128.56 respectively. (Author)

  7. Calibrating an optical scanner for quality assurance of large area radiation detectors

    International Nuclear Information System (INIS)

    A gas electron multiplier (GEM) is a particle detector used in high-energy physics. Its main component is a thin copper-polymer-copper sandwich that carries Ø =70  ±  5 µm holes. Quality assurance (QA) is needed to guarantee both long operating life and reading fidelity of the GEM. Absence of layer defects and conformity of the holes to specifications is important. Both hole size and shape influence the detector’s gas multiplication factor and hence affect the collected data. For the scanner the required lateral measurement tolerance is ± 5 µm. We calibrated a high aspect ratio optical scanning system (OSS) to allow ensuring the quality of large GEM foils. For the calibration we microfabricated transfer standards, which were imaged with the OSS and which were compared to corresponding scanning electron microscopy (SEM) images. The calibration fulfilled the ISO/IEC 17025 and UKAS M3003 requirements: the calibration factor was 1.01  ±  0.01, determined at 95% confidence level across a 950  ×  950 mm2 area. The proposed large-scale scanning technique can potentially be valuable in other microfabricated products too. (paper)

  8. Measurement of natural radiation in hot spring areas in West Java

    International Nuclear Information System (INIS)

    Springs are found in several locations in Indonesia. Some of the springs give out warm water containing natural radioactivity due to the uranium decay products, particularly containing 226Ra, 222Rn and dissolved minerals. Usually used by public for medical treatment and recreation. Measurements were carried out for radioactive concentrations, working levels, and dose rates at Cipanas, Ciater, and Ciseeng in West-Java. The concentration measurements in these areas varies from 30 to 1,331 pCi.1-1 or 1.11 to 49.25 Bq.1-1 for 226Ra and that of 1,200 to 21,700 pCi.1-1 or 44.40 to 820.90 Bq.1-1 for 222Rn. For the working level varies from 0.13 x 10-3 to 1.98x10-3 WLM. The dose rate is approximately 5.4 to 35.6 urad.h-1. The effective equivalent dose received by employees and people who live surrounding the hot springs is about 807 mrem.y-1 or 8.07 mSv.y-1 at Cipanas, 1,446 mrem.y-1 or 14.46 mSv.y-1 at Ciater, and 2,168 mrem.y-1 or 21.68 mSv.y-1 at Cipanas, respectively. (author). 7 refs, 3 figs, 6 tabs

  9. Sports Evaluation under the Background of New Rural Area Construction%新农村建设背景下农村体育研究述评

    Institute of Scientific and Technical Information of China (English)

    肖伟; 田媛; 夏成前

    2014-01-01

    运用文献资料法和逻辑分析法,以新农村建设为背景,对相关概念进行界定,对新农村建设与农村体育的关系进行分析。在此基础上,从农村体育文化建设、农民体育健身工程、农村体育公共服务、农村体育人力资源、农村体育设施建设、农村体育组织管理等方面,梳理农村体育研究成果,指出目前研究存在的问题。认为今后农村体育研究应该进一步突出农民主体地位,加强实证研究,丰富研究内容,提升研究质量,拓宽研究方向,更新研究思路。%By using the methods of document literature and logical analysis,this paper defines relevant concepts and analyses the relationship between rural construction and rural sports under the background of new rural construction.On the basis of that, this paper tidies the result for sports evaluation,and presents the problems of the current research in the aspect of rural sports culture construction,peasant fitness proj ects,public service of rural sports,rural sports human resources,rural sports equip-ment construction,rural sport organizational management,etc.It points out that we should also protrude the major part for peasant,reinforce empirical research,rich the concept of the research,improve the quality of the research,expand research di-rection and renew research thinking.

  10. Performance evaluation of the conventional Brazilian industries radiation protection in the small industrial gauges and industrial radiography areas; Sistema de avaliacao de desempenho em radioprotecao das industrias convencionais brasileiras nas areas de medidores nucleares e radiografia industrial

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Joyra Amaral dos

    1999-08-01

    This works evaluates by punctuation the performance in conventional Brazilian industries radiation protection area which make use of small industrial gauges and industrial radiography. It proposes, procedures for industry self-evaluation, besides a new radiation protection plans pattern for the small industrial gauges area. The data source where inspection reports of Dosimetry Radiation Protection Institute/Nuclear Energy Commission conventional Brazilian industries' radiation protection plans, beyond visitation to the inspection place. The performance evaluation has been realized both in the administrative and operational aspects of the industries. About of 60% of the industries have a satisfactory register control which does not happen to the operational control. The performance evaluation advantage is that industries may self-evaluate, foreseeing Dosimetry Radiation Protection Institute's regulation inspections, correcting its irregularities, automatically improving its services. The number of industries which have obtained satisfactory performance in both areas is below 70%, both in administrative and operational aspects. Such number can be considered a low one as it is radiation protection. The procedures propose in this work aim to improve such a situation. (author)

  11. Characterizing the natural radiation levels throughout the main geological units of Sabkhat al Jabboul area, northern Syria.

    Science.gov (United States)

    Al-Hilal, Mohamed; Aissa, Mosa

    2015-02-01

    The concentrations of equivalent eU, eTh, and K% were determined together with soil gas radon values and carborne gamma-ray survey in order to define the natural radioactivity levels throughout main geological units of Sabkhat al Jabboul region. Forty five soil and rock samples were collected from various lithofacies in each geological unit, and analyzed by γ-ray spectrometric technique for determining the concentration values of major radioelements. Such radiometric data could be used to differentiate between various lithologies of the investigated rocks. Although no distinct radioactive anomalies were found in the area, the radiometric profiles showed some minor variations with slightly higher values than the normal level. Despite the low radioactivity and the lack of rocks diversity in the surveyed area, it was possible to classify some certain rock types based on their radiometric response. The relationships between eU, eTh and their ratios were discussed for the Quaternary, Neogene and Paleogene formations, in order to evaluate the degree of uranium distribution and remobilization. The overall results of this radiometric survey were generally low, and lying within the range of the normal background levels in Syrian.

  12. A survey of monitoring and assay systems for release of metals from radiation controlled areas at LANL.

    Energy Technology Data Exchange (ETDEWEB)

    Gruetzmacher, K. M. (Kathleen M.); MacArthur, D. W. (Duncan W.)

    2002-01-01

    At Los Alamos National Laboratory (LANL), a recent effort in waste minimization has focused on scrap metal from radiological controlled areas (RCAs). In particular, scrap metal from RCAs needs to be dispositioned in a reasonable and cost effective manner. Recycling of DOE scrap metals from RCAs is currently under a self-imposed moratorium. Since recycling is not available and reuse is difficult, often metal waste from RCAs, which could otherwise be recycled, is disposed of as low-level waste. Estimates at LANL put the cost of low-level waste disposal at $550 to $4000 per cubic meter, depending on the type of waste and the disposal site. If the waste is mixed, the cost for treatment and disposal can be as high as $50,000 per cubic meter. Disposal of scrap metal as low-level waste uses up valuable space in the low-level waste disposal areas and requires transportation to the disposal site under Department of Transportation (DOT) regulations for low-level waste. In contrast, disposal as non-radioactive waste costs as little as $2 per cubic meter. While recycling is unavailable, disposing of the metal at an industrial waste site could be the best solution for this waste stream. A Green Is Clean (GIC) type verification program needs to be in place to provide the greatest assurance that the waste does not contain DOE added radioactivity. This paper is a review of available and emerging radiation monitoring and assay systems that could be used for scrap metal as part of the LANL GIC program.

  13. [RADIATION HYGIENIC MONITORING AT THE AREA OF THE LOCATION OF THE FAR EASTERN CENTER FOR RADIOACTIVE WASTE MANAGEMENT (FEC "DALRAO"--BRANCH OF FSUE "ROSRAO")].

    Science.gov (United States)

    Kiselev, S M; Shandala, N K; Akhromeev, S V; Gimadova, T I; Seregin, V A; Titov, A V; Biryukova, N G

    2015-01-01

    Intensification ofactivities in the field of spent nuclear fuel (SNF) and radioactive waste (RW) management in the Far East region of Russia assumes an increase of the environmental load on the territories adjacent to the enterprise and settlements. To ensure radiation safety during works on SNF and radioactive waste management in the standard mode of operation and during the rehabilitation works in the contaminated territories, there is need for the optimization of the existing system of radiation-hygienic monitoring, aimed at the implementation of complex dynamic observation of parameters of radiation-hygienic situation and radiation amount of the population living in the vicinity of the Far Eastern Center for Radioactive Waste Management (FEC "DALRAO"). To solve this problem there is required a significant amount of total and enough structured information on the character of the formation of the radiation situation, the potential ways of the spread of man-made pollution to the surrounding area, determining the radiation load on the population living in the vicinity of the object. In this paper there are presented the results of field studies of the radiation situation at the plant FEC "DALRAO", which were obtained during the course of expedition trips in 2009-2012.

  14. 区域辐射剂量监测系统的设计%The Design of Area Radiation Dose Monitoring System

    Institute of Scientific and Technical Information of China (English)

    陈颖; 侯胜利; 曾卫华; 刘海生

    2011-01-01

    The area radiation dose monitoring system is used for monitoring the radiation levels of the important nuclear reactor area to ensure the safty of radiation in the nuclear reactor. The component and function of the monitoring system as well as its circuit design and software design are introduced. The design of parallel communication is emphasized.%区域辐射剂量监测系统用于日常监测核反应堆重点区域的辐射水平,保证核反应堆运行中的辐射安全.主要介绍了监测系统的组成和功能,系统的电路设计和软件设计,重点介绍了系统中并行通信的设计.

  15. A framework for consistent estimation of leaf area index, fraction of absorbed photosynthetically active radiation, and surface albedo from MODIS time-series data

    DEFF Research Database (Denmark)

    Xiao, Zhiqiang; Liang, Shunlin; Wang, Jindi;

    2015-01-01

    model and the MODIS surface reflectance data. The estimated LAI values were then input into the ACRM to calculate the surface albedo and the fraction of absorbed photosynthetically active radiation (FAPAR). For snow-covered areas, the surface albedo was calculated as the underlying vegetation canopy...

  16. Background compensation methodologies for contamination monitoring systems

    International Nuclear Information System (INIS)

    Radiation surveillance program in the various nuclear facilities incorporate contamination monitoring as an important component. Contamination monitoring programs constitute monitoring for alpha and beta contamination of the physical entities associated with the working personnel that include his hands, feet, clothing, shoes as well as the general surface areas in the working environment like floors. All these measurements are fraught with the contribution of the ambient gamma background radiation fields. These inhibit a proper and precise estimation of the contamination concentration being monitored. This paper investigates the efficacy of two methodologies that have been incorporated in two of the contamination monitoring systems developed in the Division. In the first system discussed, a high degree of gamma compensation has been achieved for an uniform exposure of the order of 50 nSv/hr to 100 mSv/hr. In the second system discussed, the degree of gamma compensation achieved is equal to those dictated by the statistical nature of the uncertainties associated with the subtraction of background from the source data. These two methods can be very effectively employed depending on the application requirement. A minimum detection level equivalent to 0.37 Bq/cdm2 has been achieved in both these cases

  17. Radiation: boon or bane?

    International Nuclear Information System (INIS)

    Mankind has been exposed to radiation ever since the very first stage of its evolutionary development. Radiation is one of the greatest discoveries of mankind. Radiation has turned out to be a razor-sharp double-edged sword. In earlier days, it worried no one, because nobody knew about it. The correct application of radiation, be it in any field, have made lives better. Radiation in reality, a boon as well as a curse. Radiation is important but it is time we have to decide where to draw the line. For example, the match stick by itself is just a harmless object. One can use it to light a lamp or light a fire for cooking. In the hands of a mother lighting the lamp or the cooking fire, it becomes beneficial. The same match stick in the hands of a small careless child could prove to be fatal. The increased use of radiation has created fear in the minds of people regarding its possible adverse effects on living systems. Radiation is highly dangerous if not used with caution. This fear is heightened by nuclear fallouts, nuclear accidents and of high levels of natural background radiation in geographical areas in a number of countries. Terrorists may take advantage of technology and may produce nuclear weapons, which is a great risk for entire world. There are numerous reports about increasing health hazards like headache, sleep disorders, lack of concentration, infertility, memory loss, cardiovascular problems, cancer etc. which arises due to over exposure of radiation. Apart from human race, radiation affects other animals and overall environment. Although it has adverse effects on living beings but it cannot be denied that today radiation is a common and valuable tool in medicine, agriculture, research and industry. Radiation has contributed to significant improvements in fields of communications technology and energy. Radiation has proved to be an excellent source in terms of amount of energy production with generation of minimal waste. Even though it produces small

  18. Preliminary Survey of 133Xe Background Level for a Certain Area of China%我国某地区133Xe本底水平的初步调查

    Institute of Scientific and Technical Information of China (English)

    胡丹; 常印忠; 刘蜀疆; 张新军; 王军; 王世联; 李奇; 贾怀茂; 杨维耿; 杨斌; 樊元庆; 赵允刚; 陈占营

    2011-01-01

    It mainly introduces the process and results of 133Xe background preliminary survey for a certain area of china by using a noble gas xenon mobile sampling system (SAUNA). The survey process includes field sampling, sample transport and laboratory analysis of samples. 15 samples were obtained and analyzed during two weeks survey period. The results show that the Xe activity concentration background of survey area is lower than 0.2 mBq/m3.%介绍了利用SAUNA惰性气体氙移动取样设备在我国某地区进行的惰性气体氙放射性本底调查的过程和结果,包括现场取样、样品传输和实验室分析等环节.在历时15天的本底调查中共采集分析了15个样品.研究结果表明,该地区大气中133Xe的活度浓度低于0.2 mBq/m3.

  19. Pod area index, crop growth rate and intercepted photosynthetically active radiation as influenced by sowing dates in cultivars of Brassica

    International Nuclear Information System (INIS)

    Brassica napus cv. B.O.54, B. juncea cv. Pusa Bold, and B. campestris cv. Toria-T9 were sown on 3 dates [date not given] at 14 day intervals in a field experiment conducted in New Delhi, India, during 2 rabi seasons of 1993-94 and 1994-95. The highest pod area index (PAI) was attained in the first sown crop of Pusa Bold (3.0) during 1993-94 and the lowest value (1.5) was observed in the third sown crop of Toria-T9 during the same season. Due to profuse pod habit, Pusa Bold recorded the highest crop growth rate, with values of 29.4, 25.3 and 23.3 g m-2 day-1 for the first, second and third sowings, respectively, of the first season and 34.8, 30.2 and 25.8 g m-2 day-1 for the respective sowings of the second season. B.O.54 and Pusa Bold, with relatively broader leaves, intercepted 90 to 96% photosynthetically active radiation (PAR, by whole canopy) during the siliqua seed filling stage, whereas in narrow-leaved Toria-T9 the respective value was 74 to 81%. The canopy height measured in the first sown crop was 180, 200 and 120 cm in B.O.54, Pusa Bold and Toria-T9, respectively, at the maximum interception period. The maximum PAR interception decreased from the first to third sowing, and ranged from 47 to 44, 56 to 49, and 44 to 37% at 50% canopy height in B.O.54, Pusa Bold and Toria-T9, respectively. (author)

  20. Retrieval of Leaf Area Index (LAI and Fraction of Absorbed Photosynthetically Active Radiation (FAPAR from VIIRS Time-Series Data

    Directory of Open Access Journals (Sweden)

    Zhiqiang Xiao

    2016-04-01

    Full Text Available Long-term high-quality global leaf area index (LAI and fraction of absorbed photosynthetically active radiation (FAPAR products are urgently needed for the study of global change, climate modeling, and many other problems. As the successor of the Moderate Resolution Imaging Spectroradiometer (MODIS sensor, the Visible Infrared Imaging Radiometer Suite (VIIRS will continue to provide global environmental measurements. This paper aims to generate longer time series Global LAnd Surface Satellite (GLASS LAI and FAPAR products after the era of the MODIS sensor. To ensure spatial and temporal consistencies between GLASS LAI/FAPAR values retrieved from different satellite observations, the GLASS LAI/FAPAR retrieval algorithms were adapted in this study to retrieve LAI and FAPAR values from VIIRS surface reflectance time-series data. After reprocessing of the VIIRS surface reflectance to remove remaining effects of cloud contamination and other factors, a database generated from the GLASS LAI product and the reprocessed VIIRS surface reflectance for all Benchmark Land Multisite Analysis and Intercomparison of Products (BELMANIP sites was used to train general regression neural networks (GRNNs. The reprocessed VIIRS surface reflectance data from an entire year were entered into the trained GRNNs to estimate the one-year LAI values, which were then used to calculate FAPAR values. A cross-comparison indicates that the LAI and FAPAR values retrieved from VIIRS surface reflectance were generally consistent with the GLASS, MODIS and Geoland2/BioPar version 1 (GEOV1 LAI/FAPAR values in their spatial patterns. The LAI/FAPAR values retrieved from VIIRS surface reflectance achieved good agreement with the GLASS LAI/FAPAR values (R2 = 0.8972 and RMSE = 0.3054; and R2 = 0.9067 and RMSE = 0.0529, respectively. However, validation of the LAI and FAPAR values derived from VIIRS reflectance data is now limited by the scarcity of LAI/FAPAR ground measurements.

  1. Estimating Roof Solar Energy Potential in the Downtown Area Using a GPU-Accelerated Solar Radiation Model and Airborne LiDAR Data

    Directory of Open Access Journals (Sweden)

    Yan Huang

    2015-12-01

    Full Text Available Solar energy, as a clean and renewable resource is becoming increasingly important in the global context of climate change and energy crisis. Utilization of solar energy in urban areas is of great importance in urban energy planning, environmental conservation, and sustainable development. However, available spaces for solar panel installation in cities are quite limited except for building roofs. Furthermore, complex urban 3D morphology greatly affects sunlit patterns on building roofs, especially in downtown areas, which makes the determination of roof solar energy potential a challenging task. The object of this study is to estimate the solar radiation on building roofs in an urban area in Shanghai, China, and select suitable spaces for installing solar panels that can effectively utilize solar energy. A Graphic Processing Unit (GPU-based solar radiation model named SHORTWAVE-C simulating direct and non-direct solar radiation intensity was developed by adding the capability of considering cloud influence into the previous SHORTWAVE model. Airborne Light Detection and Ranging (LiDAR data was used as the input of the SHORTWAVE-C model and to investigate the morphological characteristics of the study area. The results show that the SHORTWAVE-C model can accurately estimate the solar radiation intensity in a complex urban environment under cloudy conditions, and the GPU acceleration method can reduce the computation time by up to 46%. Two sites with different building densities and rooftop structures were selected to illustrate the influence of urban morphology on the solar radiation and solar illumination duration. Based on the findings, an object-based method was implemented to identify suitable places for rooftop solar panel installation that can fully utilize the solar energy potential. Our study provides useful strategic guidelines for the selection and assessment of roof solar energy potential for urban energy planning.

  2. Announcement of recommendations issued by the German Radiation Protection Commission (Strahlenschutzkommission) - radiation protection for the use of drinking water supplies from uranium mining areas

    International Nuclear Information System (INIS)

    The recommendations issued by the German Radiation Protection Commission demand analyses of the activities of natural uranium, radium 226 and lead 210 in drinking water. The concentrations of lead 210 and polonium 210 are assumed to be balanced. The conditions for observation of the maximum permissible activities are given. The activities of radium 228 and radium 224 must be determined and be taken into account. (orig.)

  3. Study on the rules and practices in force abroad regarding the delimitation and access to regulated areas for radiation protection purposes. Final report - Appendices. Report no. 313

    International Nuclear Information System (INIS)

    Within the frame of a reviewing of European requirements in the field of radiation protection, this report presents a synthesis of rules which are applicable in seven countries (Belgium, Spain, United States, Finland, United-Kingdom, Sweden and Switzerland; a detailed report for each of these countries is provided in appendix) in the field of delimitation and access to regulated areas for radiation protection purposes. A synthesis is proposed for each country. Three countries are then selected (Finland, United Kingdom and Switzerland) and their rules and practices are applied to cases which correspond to representative exposure situations: a room with a glove box, a hall with hot spots, a parking of temporary warehousing (packages of used fuels), intermittent use of an X ray generator, use of an intense radiation beam, workshop being dismantled, laboratory in which radioactive iodine 131 is handled, and use of a mobile industrial radiography device

  4. Use of portable exposure meters for comparing mobile phone base station radiation in different types of areas in the cities of Basel and Amsterdam

    NARCIS (Netherlands)

    Urbinello, D.; Huss, A.; Beekhuizen, J.; Vermeulen, R.; Röösli, M.

    2014-01-01

    BACKGROUND: Radiofrequency electromagnetic fields (RF-EMF) are highly variable and differ considerably within as well as between areas. Exposure assessment studies characterizing spatial and temporal variation are limited so far. Our objective was to evaluate sources of data variability and the repe

  5. Studies on the assessment of radio activity in vegetables and fruits grown and consumed by residents of a typical natural high background area of South India and estimation of committed effective ingestion dose for the general public

    International Nuclear Information System (INIS)

    Radioactivity content of vegetables and fruits commonly grown and consumed by residents of a natural High Background Area (NHBRA) has been studied. Of the studied vegetable tapioca and tomato were found to have maximum activity accumulation and Kovai, minimum. Of the fruits studied, banana was found to have maximum activity. The radio activity of the corresponding soil in which they grew, was also estimated. It was found that uptake of the plant increases with the soil concentration. The maximum uptake was by tapioca and the minimum was by coconut kernel. From the gross alpha activity, concentration of Th and U were estimated and the committed effective dose, via ingestion, for general public consuming an average amount of 30 Kg per year veg and fruits, each, was calculated to be about 0.5 mSv. (author)

  6. Distribution Characteristics of Producing Area, Geological Background and Development Countermeasures of Famous Tea in Anhui Province%安徽省名茶产地分布特征、地质背景与发展对策

    Institute of Scientific and Technical Information of China (English)

    张鑫; 陈芬洁; 俞婷婷

    2012-01-01

    通过对安徽省名茶产地的实地调查,从地质学角度分析了安徽省名茶产地的地质背景对土壤中元素组合、土壤类型的影响,探讨了茶叶品质与立地环境的关系,分析了茶叶优异的品质与地质背景的相关性.结果表明,安徽省名茶产地的成土母质主要为石英砂岩、花岗岩和片麻岩等,成土母质各有特点;各类成土母质为茶树生长提供了大量的营养物质,特别是有益的微量元素对提高茶叶品质起到了重要作用.并且从已发现的名茶产地地质学规律出发,提出了安徽省的名茶发展对策.%Based on the spot investigation on famous tea in Anhui province, the geological background affecting the soil elements assemblages and soil types was analyzed; the relationship between tea quality and site conditions of growing areas was discussed; and the interrelation between excellent tea quality and geological background conditions was analyzed. The results showed that the main soil parent materials of famous tea-producing areas in Anhui province were quartz sandstone, granite and gneiss with their own peculiarity. These parent materials provide abundant nutrimental materials, especially beneficial trace elements critical to the tea quality, for the growth of tea plant. Developmental strategies for the production of famous tea in the whole province were proposed from the geological point of view.

  7. ICRP Publication 111 - Application of the Commission's recommendations to the protection of people living in long-term contaminated areas after a nuclear accident or a radiation emergency.

    Science.gov (United States)

    Lochard, J; Bogdevitch, I; Gallego, E; Hedemann-Jensen, P; McEwan, A; Nisbet, A; Oudiz, A; Oudiz, T; Strand, P; Janssens, A; Lazo, T; Carr, Z; Sugier, A; Burns, P; Carboneras, P; Cool, D; Cooper, J; Kai, M; Lecomte, J-F; Liu, H; Massera, G; McGarry, A; Mrabit, K; Mrabit, M; Sjöblom, K-L; Tsela, A; Weiss, W

    2009-06-01

    In this report, the Commission provides guidance for the protection of people living in long-term contaminated areas resulting from either a nuclear accident or a radiation emergency. The report considers the effects of such events on the affected population. This includes the pathways of human exposure, the types of exposed populations, and the characteristics of exposures. Although the focus is on radiation protection considerations, the report also recognises the complexity of post-accident situations, which cannot be managed without addressing all the affected domains of daily life, i.e. environmental, health, economic, social, psychological, cultural, ethical, political, etc. The report explains how the 2007 Recommendations apply to this type of existing exposure situation, including consideration of the justification and optimisation of protection strategies, and the introduction and application of a reference level to drive the optimisation process. The report also considers practical aspects of the implementation of protection strategies, both by authorities and the affected population. It emphasises the effectiveness of directly involving the affected population and local professionals in the management of the situation, and the responsibility of authorities at both national and local levels to create the conditions and provide the means favouring the involvement and empowerment of the population. The role of radiation monitoring, health surveillance, and the management of contaminated foodstuffs and other commodities is described in this perspective. The Annex summarises past experience of longterm contaminated areas resulting from radiation emergencies and nuclear accidents, including radiological criteria followed in carrying out remediation measures. PMID:20472181

  8. Perspective of radiation processing

    International Nuclear Information System (INIS)

    The area of the applications of radiation techniques is very wide. This paper only relates to the applications of radiation techniques in industries including radiation chemical industry, radiation processing of foods and environmental protection by radiation, but the nuclear instruments and the instrumentations of radiation are out-side of our study. (author)

  9. Measurement of spontaneous DNA damage and DNA repair capacity in healthy adult individuals from high and normal level natural radiation areas of Kerala, India

    International Nuclear Information System (INIS)

    Inhabitants of the south west coastal areas of Kerala receive high level natural radiation due to the presence of monazite (232Th) in the beach sand. This provides a unique opportunity to investigate the biological effects of high level natural radiation on humans. This study evaluate basal DNA damage in 149 healthy adult male subjects (104 from high level natural radiation areas (HLNRA, > 1mSv year-1) and 45 from normal level natural radiation area (NLNRA, d''1mSv year-1) by the alkaline comet assay. Oxidative DNA damage (ENDO III, FPG and hOGG1-sensitive sites) was measured by the enzyme modified comet assay. Induction and rejoining of DNA strand breaks was measured after irradiating peripheral blood lymphocytes with 2 Gy or 4 Gy gamma radiation. Basal damage due to age and residential area of the donors showed significant interaction (P=0.001), when all subjects were analyzed using a general linear model (GLM). In subgroup analysis, basal damage increased with age in subjects from the NLNRA (P=0.007), while a significant negative correlation (P=0.01) was observed in subjects from HLNRA. Oxidative DNA damage was not influenced by age, smoking habit or residential area in the entire sample. Subjects of high dose group from HLNRA (>5.75 mSv/y, N=34) showed a significant reduction in the induction of DNA damage after 2 Gy (P=0.03) and 4 Gy (P=0.05) compared to subjects form NLNRA. The study showed increased rejoining of DNA strand breaks in subjects from HLNRA when measured at 7 minutes after irradiation (P=0.04). In this pilot study, a low basal damage in elderly subjects from HLNRA and a reduced induction of DNA damage after 2 Gy and 4 Gy irradiation in high dose group subjects from HLNRA might suggest a possible role of chronic low dose natural radiation on the induction of an in vivo radio adaptive response. However, our findings need more validation in a larger study population. (author)

  10. The isotropic radio background revisited

    CERN Document Server

    Fornengo, Nicolao; Regis, Marco; Taoso, Marco

    2014-01-01

    We present an extensive analysis on the determination of the isotropic radio background. We consider six different radio maps, ranging from 22 MHz to 2.3 GHz and covering a large fraction of the sky. The large scale emission is modeled as a linear combination of an isotropic component plus the Galactic synchrotron radiation and thermal bremsstrahlung. Point-like and extended sources are either masked or accounted for by means of a template. We find a robust estimate of the isotropic radio background, with limited scatter among different Galactic models. The level of the isotropic background lies significantly above the contribution obtained by integrating the number counts of observed extragalactic sources. Since the isotropic component dominates at high latitudes, thus making the profile of the total emission flat, a Galactic origin for such excess appears unlikely. We conclude that, unless a systematic offset is present in the maps, and provided that our current understanding of the Galactic synchrotron emi...

  11. Background radiation and man-made and sources of radiation

    International Nuclear Information System (INIS)

    This paper describes the development of the use of the atom and its present applications in food and agriculture, industry medicine and health care, energy-environment and research. These applications have inevitably led to concerns about nuclear safety and radioactive waste management and the need for the adoption of procedures for control, safe use and disposal of radioactive sources

  12. Intensity-modulated pelvic radiation therapy and simultaneous integrated boost to the prostate area in patients with high-risk prostate cancer: a preliminary report of disease control

    OpenAIRE

    Saracino, Biancamaria; Petrongari, Maria Grazia; Marzi, Simona; Bruzzaniti, Vicente; Sara, Gomellini; Arcangeli, Stefano; Arcangeli, Giorgio; Pinnarò, Paola; Giordano, Carolina; Ferraro, Anna Maria; Strigari, Lidia

    2014-01-01

    The aim of the study was to report the clinical results in patients with high-risk prostate cancer treated with pelvic intensity-modulated radiation therapy (IMRT) and simultaneous integrated boost (SIB) to the prostate area. A total of 110 patients entered our study, 37 patients presented with localized prostate cancer and radiological evidence of node metastases or ≥15% estimated risk of lymph node (LN) involvement, while 73 patients underwent postoperative adjuvant or salvage irradiation f...

  13. The value of exchange visits of stakeholders in the education and training processes in the area of radiation protection and safety culture

    International Nuclear Information System (INIS)

    Exchange visits offer a bundle of benefits, well beyond just acquiring information. The value of exchange visits of stakeholders in the education and training processes in the area of radiation protection and safety culture is demonstrated on the activities performed within the EC projects NERIS-TP and PREPARE under the umbrella of the European NERIS Platform. The technical visits to the affected regions of Belarus close to Chernobyl NPP as well as Fukushima Mission 2013 on the FAIRDO and ISAP 2013 in Japan illustrate well the methods of wide range of stakeholders engagement and involvement in the area of radiation control and practical radiological culture and their benefit in the education and training process. These visits have created common understanding, relationships forged in the hardships of shared experience, commitments to new approaches, and friendships as foundation for future networking. Technical visits allowed Slovak stakeholders and Belorussian hosts to focus time and attention on a topic, learning deeply, sharing ideas, and assessing the relevance of new approaches in the area of the post-accident management and rehabilitation with the main goal of improvement both national and local plans for preparedness and recovery. The technical or study visits for education and training purpose are valuable in the process of enhancement of the radiation protection and safely culture. (authors)

  14. 某铀矿区退役后环境辐射水平调查%Environmental Radiation Level Survey of a Remediated Uranium Mining Area in Xinjiang

    Institute of Scientific and Technical Information of China (English)

    赵其文; 王国全

    2015-01-01

    The environmental radiation level of a uranium mining area ,once remediated ,was surveyed .It is showed that 226 Ra content in soil samples from some locations exceeds the limit requirement ,and measures are needed to be taken to have the area further remediated .%对某铀矿区退役后辐射环境进行了调查监测。监测结果表明,某铀矿退役场所部分点位土样中核素226 Ra含量超出限值要求,急需采取措施进行治理。

  15. 4. S.F.R.P. days on the optimization of radiation protection in the electronuclear, industrial and medical areas

    International Nuclear Information System (INIS)

    These days are dedicated to the implementation of the radiation protection optimization in the activities of the electronuclear sector, of the industrial sector, the medical sector, the laboratories and the centers of research and the university sector. All the aspects of the practical application of the radiation protection optimization of the workers, the public and the patients will be approached. The oral communications and posters concern the following subjects: foundations of the optimization principle, new statutory context, transmission of ALARA principle, operational dosimetry, conception, operating and maintenance of the installations, the construction sites of dismantling, industrial radiology, radioactive waste management. (N.C.)

  16. Comparison of childhood thyroid cancer prevalence among 3 areas based on external radiation dose after the Fukushima Daiichi nuclear power plant accident

    Science.gov (United States)

    Ohira, Tetsuya; Takahashi, Hideto; Yasumura, Seiji; Ohtsuru, Akira; Midorikawa, Sanae; Suzuki, Satoru; Fukushima, Toshihiko; Shimura, Hiroki; Ishikawa, Tetsuo; Sakai, Akira; Yamashita, Shunichi; Tanigawa, Koichi; Ohto, Hitoshi; Abe, Masafumi; Suzuki, Shinichi

    2016-01-01

    Abstract The 2011 Great East Japan Earthquake led to a subsequent nuclear accident at the Fukushima Daiichi Nuclear Power Plant. In its wake, we sought to examine the association between external radiation dose and thyroid cancer in Fukushima Prefecture. We applied a cross-sectional study design with 300,476 participants aged 18 years and younger who underwent thyroid examinations between October 2011 and June 2015. Areas within Fukushima Prefecture were divided into three groups based on individual external doses (≥1% of 5 mSv, <99% of 1 mSv/y, and the other). The odds ratios (ORs) and 95% confidence intervals of thyroid cancer for all areas, with the lowest dose area as reference, were calculated using logistic regression models adjusted for age and sex. Furthermore, the ORs of thyroid cancer for individual external doses of 1 mSv or more and 2 mSv or more, with the external dose less than 1 mSv as reference, were calculated. Prevalence of thyroid cancer for the location groups were 48/100,000 for the highest dose area, 36/100,000 for the middle dose area, and 41/100,000 for the lowest dose area. Compared with the lowest dose area, age-, and sex-adjusted ORs (95% confidence intervals) for the highest-dose and middle-dose areas were 1.49 (0.36–6.23) and 1.00 (0.67–1.50), respectively. The duration between accident and thyroid examination was not associated with thyroid cancer prevalence. There were no significant associations between individual external doses and prevalence of thyroid cancer. External radiation dose was not associated with thyroid cancer prevalence among Fukushima children within the first 4 years after the nuclear accident. PMID:27583855

  17. 连片特困地区扶贫攻坚的战略选择%Strategic Choices of Poverty Alleviation in Contiguous Destitute Areas Under Background of Ecological Civilization Construction

    Institute of Scientific and Technical Information of China (English)

    李晓龙; 徐鲲

    2014-01-01

    The report at 18th CPC National Congress points out that the construction of ecological civilization will be put into a prominent position,blending in economic,political,cultural and social construction and all aspects of the whole process to build a beautiful China and achieve sustainable development of China. In China,poverty and fragile ecological environment is often symbiotic. Most of rural poor population live in contiguous areas ,and thus, area poverty alleviation plays an extremely important role in the ecological civilization construction. Based on the background of ecological civilization construction and the analyses of challenges contiguous destitute areas face in ecological civilization construction,this paper expounds on strategic choices of poverty alleviation in contiguous destitute areas from such aspects as optimizing the spatial pattern,adjusting the industrial structure,improving production modes,improving lifestyle to provide useful references for the areas to promote poverty alleviation and ecological civilization construction.%党的十八大报告提出,把生态文明建设放在突出地位,融入经济建设、政治建设、文化建设、社会建设各方面和全过程,努力建设美丽中国,实现中华民族永续发展。在我国,贫困与生态环境脆弱往往是共生的。我国农村贫困人口大部分分布在连片特困地区,因而,片区扶贫攻坚在生态文明建设中处于极为重要的地位。本文通过分析连片特困地区生态文明建设面临的挑战,从优化空间格局、调整产业结构、改进生产方式、完善生活方式等四个方面论述了连片特困地区扶贫攻坚的战略选择,为该地区推进扶贫开发与生态文明建设提供一些有益的参考。

  18. THE CORRELATION BETWEEN INDOOR RADON CONCENTRATIONS AND GEOLOGICAL BACKGROUNDS IN SOME TYPICAL AREAS OF BEIJING AND GUANGDONG%北京广东典型地区室内氡气浓度与地质背景关系

    Institute of Scientific and Technical Information of China (English)

    秦春艳; 王南萍; 肖磊; 储星铭

    2012-01-01

    For the purpose of studying the indoor radon level under different geological backgrounds, the authors measured indoor radon concentrations by pulse chamber radon monitor AlphaGUARD in some typical areas of Guangdong and Beijing, and also made long-term monitoring of indoor radon concentrations at a measuring site in Guangdong. The results show that surface lithology is one of the most important factors affecting indoor radon. The indoor radon in the granite area is higher than that in other lilhologic areas, and the level of indoor radon in Guangdong is apparently higher than that in Beijing. The average concentrations of indoor radon in Guangdong and Beijing are respectively 69.98 Bq/m3 and 43.97 Bq/m3 for granite area, and 43.60 Bq/m3,35.74 Bq/m3 for Quaternary area. The level of indoor radon in the residence is slightly higher than that in office buildings and restaurants. The study of the distribution and level of indoor radon in combination with geological background is of guiding significance for the selection of the indoor radon survey points and also has important practical value for regional scale indoor radon evaluation.%为了解不同地质背景条件室内氡浓度水平,采用脉冲电离室测氡仪AlphaGUARD测量了北京广东不同地质背景典型测点的室内氡浓度,同时对广东某一测点进行了长期的室内氡监测.测量和研究结果表明:地表岩性是影响室内氡浓度高低的重要因素之一.地处花岗岩地区的建筑物内氡浓度高于其他岩性地区的室内氡浓度,广东室内氡水平明显高于北京地区,广东北京花岗岩地区的平均室内氡浓度分别为69.98 Bq/m3和43.97 Bq/m3,第四系覆盖地区的平均室内氡浓度分别为43.60 Bq/m3和35.74 Bq/m3.民用住宅卧室内的室内氡浓度略高于公共建筑物办公室内的室内氡浓度.因此,结合地质背景研究室内氡的水平与分布对指导开展室内氡调查中确定抽样方案、选择测点及

  19. THE EFFECTS OF RADIATION STRESS ON WAVE HEIGHTS AND SEA LEVEL IN THE INTERACTION OF COUPLED WAVE-TIDE-SURGE IN THE COASTAL AREA

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Based on coastal high-resolution (2′×2′) coupled wave-tide-surge interaction numerical model, the effects of radiation stress on wave heights and sea level in the coastal area of Huanghe Delta were studied. By comparisons of simulated and measured wave heights and sea level for two mediately strong weather cases, it is demonstrated that the results simulated by coupled wave-tide-surge model are closer to the measured and particularly in excellent agreement in the extreme values of the wave heights and set-up. This study shows that the radiation stress can increase the wave heights maximally to 67cm and sea level to 40cm. It is also found that there are areas of over 50cm wave height increase and an area of over 20cm sea level increase in the Huanghe Delta coastal area, and this find may be very important in engineering. For this reason, it is suggested that in the practical engineering application, the coupled wave-tide-surge interaction numerical model should be prefered.

  20. On Evolution of Rural Spatial Structure in Western Area under the Background of Urbanization%城镇化进程中西部地区乡村空间结构演化研究

    Institute of Scientific and Technical Information of China (English)

    姜侣

    2015-01-01

    Under the background of China’s balancing urban and rural development and vigorously promoting urbanization ,analysis on the evolution of rural spatial structure is conducive to grasp the general characteristics of evolution of rural spatial structure ,and to make better planning for the spatial pattern of countryside .Based on Krugman’ s spatial economic thought ,also considering the actual situation of the western region in China , the research analyzes the three levels of differentiation evolution model on the different geographic space distance in the western region of rural spatial structure under the background of urbanization ,and builds a theoretical model of rural spatial structure evolution to provide a theoretical basis for the rural spatial structure evolution in western areas .And the model show s that rural spatial structure evolution on appropriate geographic space distance can effectively avoid rural hollowing out and disorderly construction ,and eliminate the gap between urban and rural areas ,which will better promote the new rural construction in China .%在我国统筹城乡发展、大力推进城镇化建设的背景下,分析乡村空间结构的演化,有利于把握乡村空间结构演化的总体特征,更好地规划乡村的空间格局。以克鲁格曼的空间经济学思想为基础,从西部地区的实际情况出发,分析了城镇化背景下乡村空间结构在不同地理空间距离上的三层级分异演化模式,并在此基础上,构建乡村空间结构演化的理论模型,为西部地区乡村空间结构的分异演化提供了理论依据。研究表明,乡村空间结构在合适地理空间距离上的分异演化能够有效避免乡村空心化和乡村无序建设,进一步消除城乡二元差距,进而更好地推进我国的新农村建设。