World high background natural radiation areas: Need to protect public from radiation exposure

International Nuclear Information System (INIS)

Sohrabi, Mehdi

2013-01-01

Highlights of findings on radiological measurements, radiobiological and epidemiological studies in some main world high background natural radiation (HBNR) areas such as in Brazil, China, India and Iran are presented and discussed with special regard to remediation of radiation exposure of inhabitants in such areas. The current radiation protection philosophy and recommendations applied to workers and public from operation of radiation and nuclear applications are based on the linear non-threshold (LNT) model. The inhabitants of HBNR and radon prone areas receive relatively high radiation doses. Therefore, according to the LNT concept, the inhabitants in HBNR areas and in particular those in Ramsar are considered at risk and their exposure should be regulated. The HBNR areas in the world have different conditions in terms of dose and population. In particular, the inhabitants in HBNR areas of Ramsar receive very high internal and external exposures. This author believes that the public in such areas should be protected and proposes a plan to remedy high exposure of the inhabitants of the HBNR areas of Ramsar, while maintaining these areas as they stand to establish a national environmental radioactivity park which can be provisionally called “Ramsar Research Natural Radioactivity Park” (RRNRP). The major HBNR areas, the public exposure and the need to remedy exposures of inhabitants are reviewed and discussed. - Highlights: ► Highlights of findings on studies in HBNR areas are reviewed and discussed. ► The need to protect HBNR area inhabitants and remedy public exposure is emphasized. ► A collective approach is proposed to remedy exposure of Ramsar HBNR area inhabitants. ► Relocation of HBNR area inhabitants and establishing a park at the location is proposed. ► The advantages and disadvantages of the methods are discussed and recommendations are made

Levels of thoron and progeny in high background radiation area of southeastern coast of Odisha (India))

International Nuclear Information System (INIS)

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.

2012-01-01

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. (authors)

Levels of thoron and progeny in high background radiation area of southeastern coast of Odisha (India))

Energy Technology Data Exchange (ETDEWEB)

Ramola, R C; Gusain, G S; Rautela, B S [Dept. of Physics, H.N.B. Garhwal Univ., Badshahi Thaul Campus, Tehri Garhwal 249199 (India); Sagar, D V [Health Physics Unit EAD, BARC, IRE, OSCOM, Matikhalo, Ganjam, Odisha 761 045 (India); Prasad, G; Shahoo, S K; Ishikawa, T; Omori, Y; Janik, M [National Inst. of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555 (Japan); Sorimachi, A; Tokonami, S [Inst. of Radiation Emergency Medicine, Hirosaki Univ., Aomori 036-8564 (Japan)

2012-07-01

Exposure to radon, {sup 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, {sup 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 {sup 220}Rn and its progeny can equal or several time exceed that of {sup 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. (authors)

Concentration of 210Po in local foodstuffs grown nearby High Background Areas (HBRA)

International Nuclear Information System (INIS)

Kamesh Viswanathan, B.; Arunachalam, Kantha D.; Sathesh Kumar, A.; Jayakrishna, K.; Rao, D.D.

2012-01-01

210 Po is the decay product of natural radionuclide of 238 U series. The presence of a radionuclide migrates from soil > plant > food and ingested by the humans residing in the areas of syentite rocks nearby the High Background Radiation Area's (HBRA). The food samples were studied by Market Basket Study (MBS). The average concentration of 210 Po in foodstuffs like green leafy vegetables, other vegetables, roots and tubers; fruits, fish, other flesh foods, milk and cereals were 1671 ± 163.3, 28.2 ± 7.3, 320 ± 99, 53 ± 17.5, 251.5 ± 54.5, 37 ± 14.5, 16 ± 6 and 230 ± 75 mBq. Kg -1 fresh weight. (author)

Cytogenetic study of stable chromosome aberrations in residents of a high background radiation area in China

International Nuclear Information System (INIS)

Zhang Wei; Wang Chunyan; Chen Deqing; Wei Lvxin

2004-01-01

Objective: To investigate the effect of high background radiation on the induction of stable chromosome aberrations. Methods: By fluorescence in situ hybridization (FISH) technique chromosome Nos. 1, 2 and 4 were painted using specific biotin-labeled whole chromosome painting probes. Peripheral blood specimens were taken from 31 individuals living in the high background radiation area (HRBA) and 29 individuals in the control area. Results: No significant difference was found in the frequencies of translocations between HBRA and the control (P>0.05, Mann-Whitney U test) for both children and elderly individuals. On the other hand, correlation between age and translocation frequencies was significant at the 1% level (r s =0.388 with 56DF). Conclusion: There are no differences in the frequencies of translocations between HBRA and the control area. The present result indicates that the contribution of an elevated level of natural radiation in HBRA in China to the induction rate of stable type aberrations (translocations) dose not have a significant effect compared with the contributions from all other sources such as chemical mutagens and(or) metabolic factors. (authors)

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

International Nuclear Information System (INIS)

Li Jia; Su Gasaki, H.; Yang Yuhua

1997-01-01

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

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Chromosome translocation in residents of the high background radiation areas in southern China

International Nuclear Information System (INIS)

Hayata, Isamu; Minamihisamatsu, Masako; Wang Chunyan; Wei Zhang; Chen Deqing; Morishima, Hiroshige; Yuan Yongling; Wei Luxin; Sugahara, Tsutomu

2000-01-01

We performed a cytogenetical study using chromosome painting analysis on 9 residents of the naturally high background radiation areas (HBRA) and 8 residents of the control areas in southern China. The estimated dose (air kerma) of each resident measured by an electric pocket dosimeter showed 2.20-4.23 mGy/year in HBRA and 0.56-0.70 mGy/year in the control areas. A total of 14,096 cells (1,566 cells/case) in the former and 17,522 cells (2,190 cells/case) in the latter were analyzed. Children, both in HBRA and in the control areas, had translocations at low frequencies. The frequency of translocations among elder individuals varied widely and it was not possible to detect dose effect although it was detected in dicentrics. The effect of radiation on the induction of chromosome aberrations, which have a statistically potential risk of causing malignant or congenital diseases, seems to be less significant than those of metabolic factors and/or mutagenic agents (excluding radiation) even in HBRA in China. (author)

High background radiation area: an important source of exploring the health effects of low dose ionizing radiation

International Nuclear Information System (INIS)

Wei Luxin

1997-01-01

Objective: For obtaining more effective data from epidemiological investigation in high background radiation areas, it is necessary to analyze the advantages, disadvantages, weak points and problems of this kind of radiation research. Methods: For epidemiological investigation of population health effects of high background radiation, the author selected high background radiation areas of Yangjiang (HBRA) and a nearby control area (CA) as an instance for analysis. The investigation included classification of dose groups, comparison of the confounding factors in the incidence of mutation related diseases, cancer mortalities and the frequencies of chromosomal aberrations between HBRA and CA. This research program has become a China-Japan cooperative research since 1991. Results: The confounding factors above-mentioned were comparable between HBRA and CA, and within the dose groups in HBRA, based on a systematic study for many years. The frequencies of chromosomal aberrations increased with the increase of cumulative dose, but not for children around or below 10 years of age. The relative risks (RR) of total and site-specific cancer mortalities for HBRA were lower or around 1.00, compared with CA. The incidence of hereditary diseases and congenital deformities in HBRA were in normal range. The results were interpreted preliminarily by the modified 'dual radiation action' theory and the 'benefit-detriment competition' hypothesis. Conclusions: The author emphasizes the necessity for continuing epidemiological research in HBRA, especially for international cooperation. He also emphasizes the importance of combination of epidemiology and radiobiology

Measurement of high natural background radiation levels by TLD at Cox's Bazar coastal areas in Bangladesh

International Nuclear Information System (INIS)

Mollah, A.S.; Rahman, M.M.; Koddus, M.A.; Husain, S.R.; Malek, M.A.

1987-01-01

High natural background radiation levels at the Cox's Bazar coastal areas in Bangladesh were measured by LiF (TLD-100) dosemeters. The dose rates varied from 2621 to 35391 μGy.y -1 with a mean of 11968 μGy.y -1 . The average dose rate is found to significantly higher than the world average value. In order to formulate appropriate guidelines for radiation protection of the population in this area, the necessary recommendations are described. (author)

Cytogenetic studies on newborns from high level natural background radiation areas of Kerala coast, South India

International Nuclear Information System (INIS)

Cherian, V.D.; Kurien, C.J.; Das, Birajalaxmi

1997-01-01

The human population residing in the monazite bearing high level natural background radiation (HLNBR) areas of Kerala, along the South-West coast of India provides unique opportunities of assessing directly in man, the health effects of chronic low-level radiation exposure. The per capita dose received by this population is nearly four times the normal background radiation level. While this is the average dose, the radiation levels prevailing in these HLNBR areas are in the range of 1 to over 35 mGy per year. Chromosomal aberration studies in the lymphocytes of newborns and adults from these areas have been in progress for two decades. So far, 4156 newborn babies from HLNBR and 7321 from normal background radiation (NBR) areas have been screened for the incidence of chromosomal aberrations (dicentrics and rings). The mean frequency of dicentrics and rings did not show any significant difference between the newborns in the control and the HLNBRA population. Assessment of the frequency of micronuclei in cytochalasin-B blocked binucleated lymphocytes of 49 newborns from control areas and 131 newborns from radioactive areas also showed similar values. While an age-dependent increase in chromosome aberration frequency was observed in the adult samples from control and the study areas, the regression analysis of the data indicated a marginally higher slope for the samples from HLNBRA. Karyotype anomalies recorded so far among the newborns have not revealed any significant difference in the incidence of numerical (including Down syndrome) and structural alterations between the control and the exposed populations. A noteworthy observation, herein reported for the first time from any HLNBR area is that there is no discernible increase in the incidence of micronuclei and chromosomal aberrations in the peripheral lymphocytes of newborn babies hailing from HLNBR areas, where their ancestral generations have lived for several hundreds of years. (author)

Review of epidemiological and cytogenetic studies on high background radiation area residents

International Nuclear Information System (INIS)

Iwasaki, Toshiyasu

2008-01-01

Emerging scientific knowledge in the field of radiation biology has put into question the generic use of a simple linear extrapolation of radiation effects from high to low dose or dose rate. Though the direct information of biological effects at low dose or low dose rate has been accumulated, it is still immature to mention health effects as the consequence of biological effects. As epidemiological data have been the main sources of direct information on human health effects, studies of the health of population exposed by low dose or low dose rate ionizing radiation will help to improve our understanding. In this meaning, the epidemiological studies of residents in high background radiation areas (HBRA), which are supported by us, will provide important direct information on the biological and health effects of chronic low dose rate ionizing radiation. The epidemiological results in HBRA in China showed there are no significant increases of cancer risks caused by the high background levels of ionizing radiation. From the results which come from cytogeneticl studies, the frequencies of unstable chromosomal aberrations have shown good correlation with cumulative doses in their lifetimes, which indicated it is a sensitive and informative biomarker. On the other hand, the frequencies of stable chromosomal aberrations have shown no significant difference and the frequency was much higher than that of unstable type aberrations. It suggests that mutagenic factors other than radiation contribute more than the elevated level of radiation to the induction of DNA rearrangements which could lead to the increase of cancer risk in HBRA in China. (author)

Preliminary indoor thoron measurements in high radiation background area of southeastern coastal Orissa (India)

International Nuclear Information System (INIS)

Ramola, R. C.; Prasad, G.; Gusain, G. S.; Rautela, B. S.; Choubey, V. M.; Vidya Sagar, D.; Tokonami, S.; Sorimachi, A.; Sahoo, S. K.; Janik, M.; Ishikawa, T.

2010-01-01

This paper presents the preliminary results of radon and thoron measurements in the houses of Chhatrapur area of southeastern coast of Orissa (India). This area is one of the high radiation background radiation areas in India, which consists of monazite sand as the source of thoron. Both active and passive methods were employed for the measurements. Radon and thoron concentrations were measured in the houses of Chhatrapur area using twin cup radon dosemeters, RAD7 and radon-thoron discriminative detector (Raduet). Thoron progeny concentration was also measured in the houses using deposition rate measurements. Radon and thoron concentrations in the houses of study area were found to vary from 8 to 47 Bq m -3 and the below detection level to 77 Bq m -3 , respectively. While thoron progeny concentration in these houses ranges between 0.17 and 4.24 Bq m -3 , preliminary investigation shows that the thoron concentration is higher than radon concentration in the houses of the study area. The thoron progeny concentration was found to be comparatively higher, which forms a base for further study in the area. The comparison between the results of various techniques is presented in this paper. (authors)

Preliminary indoor thoron measurements in high radiation background area of southeastern coastal Orissa (India)

Energy Technology Data Exchange (ETDEWEB)

Ramola, R C; Prasad, G; Gusain, G S; Rautela, B S [Dept. of Physics, H.N.B. Garhwal Univ., Badshahi Thaul, Tehri Garhwal 249 199 (India); Choubey, V M [Wadia Inst. of Himalayan Geology, Dehradun 248 001 (India); Vidya Sagar, D [Health Physics Unit (EAD, BARC), IRE, OSCOM, Matikhalo, Dt. Ganjam, Orissa 761 045 (India); Tokonami, S; Sorimachi, A; Sahoo, S K; Janik, M; Ishikawa, T [National Inst. of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263 8555 (Japan)

2010-07-01

This paper presents the preliminary results of radon and thoron measurements in the houses of Chhatrapur area of southeastern coast of Orissa (India). This area is one of the high radiation background radiation areas in India, which consists of monazite sand as the source of thoron. Both active and passive methods were employed for the measurements. Radon and thoron concentrations were measured in the houses of Chhatrapur area using twin cup radon dosemeters, RAD7 and radon-thoron discriminative detector (Raduet). Thoron progeny concentration was also measured in the houses using deposition rate measurements. Radon and thoron concentrations in the houses of study area were found to vary from 8 to 47 Bq m{sup -3} and the below detection level to 77 Bq m{sup -3}, respectively. While thoron progeny concentration in these houses ranges between 0.17 and 4.24 Bq m{sup -3}, preliminary investigation shows that the thoron concentration is higher than radon concentration in the houses of the study area. The thoron progeny concentration was found to be comparatively higher, which forms a base for further study in the area. The comparison between the results of various techniques is presented in this paper. (authors)

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

International Nuclear Information System (INIS)

Lei Shujie; Li Xiaojuan; Sun Quanfu; Wei Lvxin; Gen Jiwu; Wen Cuiju; Tan Huizhen; Zou Jianmin

2007-01-01

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)

Background simulations for the Large Area Detector onboard LOFT

DEFF Research Database (Denmark)

Campana, Riccardo; Feroci, Marco; Ettore, Del Monte

2013-01-01

and magnetic fields around compact objects and in supranuclear density conditions. Having an effective area of similar to 10 m(2) at 8 keV, LOFT will be able to measure with high sensitivity very fast variability in the X-ray fluxes and spectra. A good knowledge of the in-orbit background environment...... is essential to assess the scientific performance of the mission and optimize the design of its main instrument, the Large Area Detector (LAD). In this paper the results of an extensive Geant-4 simulation of the instrumentwillbe discussed, showing the main contributions to the background and the design...... an anticipated modulation of the background rate as small as 10 % over the orbital timescale. The intrinsic photonic origin of the largest background component also allows for an efficient modelling, supported by an in-flight active monitoring, allowing to predict systematic residuals significantly better than...

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

International Nuclear Information System (INIS)

Zhang Zhonghou

1985-01-01

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

Epidemiological and radio-biological studies in high background radiation areas of Kerala coast: implications in radiation protection science and human health

International Nuclear Information System (INIS)

Das, Birajalaxmi

2018-01-01

Till date, Linear No Threshold hypothesis (LNT) is well accepted in radiation protection science in spite of its limitations. However, dose response studies using multiple biological end points from high-background radiation areas have challenged the linearity. Radio-biological and epidemiological studies from high level natural radiation areas of Kerala coast showed non-linearity as well as efficient repair of DNA damage in HLNRA indicating that dose limits for public exposure needs to be revisited which may have implications in radiation protection science, human health and low dose radiation biology. However, further studies using high throughput approach is required to identify chronic radiation signatures in human population exposed to elevated level of natural background radiation

Problems Concerning Dose Assessments in Epidemiology of High Background Radiation Areas of Yangjiang, China (invited paper)

International Nuclear Information System (INIS)

Wei, L.X.; Yuan, Y.L.

1998-01-01

The purpose of this study on radiation levels and dose assessments in the epidemiology of a high background radiation area (HBRA) and the control area (CA) is to respond to the needs of epidemiology in these areas, where the inhabitants are continuously exposed to low dose, low dose rate ionising radiation. A brief description is given of how the research group evaluated the feasibility of the investigation by analysing the population size and the radiation levels, how simple reliable methods were used to get the individual annual dose for every cohort member, and how the cohort members were classified into various dose groups for dose-effect relationship analysis. Finally, the use of dose group classification for cancer mortality studies is described. (author)

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.

Biological effects of low-dose radiation on human population living in high-background radiation areas of Kerala coast

International Nuclear Information System (INIS)

Das, Birajalaxmi

2016-01-01

High-level natural radiation areas (HLNRA) of Kerala coast is densely populated and known for its wide variation in background radiation dose levels due to uneven distribution of monazite in the beach sand. The background radiation dose varies from 1 to 45 mGv/y. The areas with >1.5mGy/y is considered as HLNRA. Human population inhabiting in this area are exposed to low-dose chronic radiation since generations. Hence, this population provides an ideal situation to study dose response and adaptive response, if any, due to natural chronic low-dose exposure. It has been investigated extensively to study the biological and health effects of long-term low-dose/low-dose radiation exposure. So far over 150, 000 newborns monitored from hospital-based study did not reveal any significant difference in the incidence of any of the malformations and stillbirth between HLNRA and adjacent control areas. A case-control study on cleft lip/palate and mental retardation did not show any association with background radiation dose. Cytogenetic investigation of over 27,000 newborns did not show any significant increase in the frequency of chromosome aberrations and karyotype anomalies. DNA damage endpoints, such as micronuclei, telomere length and DNA strand breaks, did not reveal any significant difference between control and exposed population. Studies on DNA damage and repair revealed efficient repair of DNA strand breaks in HLNRA individuals. Molecular studies using high throughput microarray analysis indicated a large number of genes involved in various molecular and cellular pathways. Indications of in vivo radioadaptive response due to natural chronic low-dose exposure in this population have important implications to human health. (author)

Low risk of pulmonary tuberculosis of residents in high background radiation area, Yangjiang, China

International Nuclear Information System (INIS)

Li Xiaojuan; Sun Quanfu

2006-01-01

Objective: To examine the pulmonary tuberculosis mortality risk of the residents in high background radiation area (HBRA), Yangjiang, China. Methods: A cohort including 89 694 persons in HBRA and 35 385 persons in control area (CA) has been established since 1979. Person-year tables based on classified variables including sex, attained age, follow-up calendar year, and dose-rate group (high, intermediate, and low in HBRA, and control group) were tabulated using DATAB in EPICURE. Poisson regression analysis was used to estimate the relative risks (RR) of infectious and parasitic disease especially for pulmonary tuberculosis. Cumulative dose for each cohort member was obtained. Results: Two million person-years were accumulated by follow-up and 612 cases of pulmonary tuberculosis ascertained. Compared with risk in the control area, statistically significant lower risk of pulmonary tuberculosis was observed in HBRA among those who aged 60 years and over; markedly decreased risk occurred among males; no significant difference was found among the 6 follow-up stages, two subregions in the HBRA, or different diagnostic facilities. A statistically significantly negative dose-response was observed (P<0.001), the higher accumulative dose, the lower dose the pulmonary tuberculosis mortality risk. Its excess relative risk (ERR/Sv) was estimated to be -1.09 (95% CI: -1.34, -0.85). No established risk factors could explain this lower risk. Conclusions: The mortality of puhnonary tuberculosis among residents in HBRA who were chronically exposed to low-dose radiation was statistically significantly lower than that in the control area, and a significant dose-response relationship was observed, which probably resulted from the immunoenhancement of low dose radiation. (authors)

THE HIGH BACKGROUND RADIATION AREA IN RAMSAR IRAN: GEOLOGY, NORM, BIOLOGY, LNT, AND POSSIBLE REGULATORY FUN

Energy Technology Data Exchange (ETDEWEB)

Karam, P. A.

2002-02-25

The city of Ramsar Iran hosts some of the highest natural radiation levels on earth, and over 2000 people are exposed to radiation doses ranging from 1 to 26 rem per year. Curiously, inhabitants of this region seem to have no greater incidence of cancer than those in neighboring areas of normal background radiation levels, and preliminary studies suggest their blood cells experience fewer induced chromosomal abnormalities when exposed to 150 rem ''challenge'' doses of radiation than do the blood cells of their neighbors. This paper will briefly describe the unique geology that gives Ramsar its extraordinarily high background radiation levels. It will then summarize the studies performed to date and will conclude by suggesting ways to incorporate these findings (if they are borne out by further testing) into future radiation protection standards.

Down syndrome and the high background radiation areas of Kerala

International Nuclear Information System (INIS)

Jaikrishan, G.; Ramachandran, E.N.; Karuppasamy, C.V.; Sudheer, K.R.; Andrews, V.J.; Soren, D.C.; Anil Kumar, V.; Koya, P.K.M.; Cheriyan, V.D.; Seshadri, M.

2010-01-01

Down syndrome (DS) or trisomy-21 is a complex human clinical entity compromising several functional, structural and developmental features with wide variation in expression levels. The diagnosis is confirmed in majority of the cases by an extra dose of chromosome 21 by cytogenetics and occasionally it may be due to either chromosomal translocation or mosaicism (different cell lines in the same individual). The extra chromosome 21 is usually formed by non-disjunction during meiosis and is the most common numerical chromosomal anomaly compatible with life, as chromosome 21 is one of the smallest with relatively fewer genes most of which are reckoned to be non lethal. Though exact causative factors and pathogenesis is not fully understood, a rise in maternal age at conception coupled with deleterious environmental influence on an ageing ovum is a recognized risk factor. The de novo nature of trisomy-21 and its relatively higher frequency makes it a reliable indicator to assess the role of chronic high background radiation in inducing germ line mutation and congenital malformation. Many other relatively common congenital malformations with multifactorial origin may not have this de novo property and associating its incidence with the prevailing natural background radiation become more complex. In vitro studies have shown association between high intensity radiation and genetics effects but such a relationship so far was not established between DS and radiation

Radioecology teaching: evaluation of the background radiation levels from areas with high concentrations of radionuclides in soil

International Nuclear Information System (INIS)

Anjos, R M; Okuno, E; Gomes, P R S; Veiga, R; Estellita, L; Mangia, L; Uzeda, D; Soares, T; Facure, A; Brage, J A P; Mosquera, B; Carvalho, C; Santos, A M A

2004-01-01

The study of environmental radioactivity is a topic which is not usually included in physics courses in Brazilian and Latin American universities. Consequently, high-school teachers are not able to show experimentally or discuss with their students the effects of exposure to terrestrial radiation. This paper presents a laboratory experiment in a teaching programme on the physics of ionizing radiation. It is based on the evaluation of the background radiation levels from areas with high concentrations of natural or artificial radionuclides in the soil. A brief analysis of the theory behind the technique and a description of some measurements, including their interpretations, are presented

Beta activity measurements in high, variable gamma backgrounds

International Nuclear Information System (INIS)

Stanga, D.; Sandu, E.; Craciun, L.

1997-01-01

In many cases beta activity measurements must be performed in high and variable gamma backgrounds. In such instances it is necessary to use well-shielded detectors but this technique is limited to laboratory equipment and frequently insufficient. In order to perform in a simple manner beta activity measurements in high and variable backgrounds a software-aided counting technique have been developed and a counting system have been constructed. This technique combines the different counting techniques with traditional method of successive measurement of the sample and background. The counting system is based on a programmable multi-scaler which is endowed with appropriate software and allow all operations to be performed via keyboard in an interactive fashion. Two large - area proportional detectors were selected in order to have the same background and the same gamma response within 5%. A program has been developed for the counting data analysis and beta activity computing. The software-aided counting technique has been implemented for beta activity measurement in high and variable backgrounds. (authors)

Nested case-control study on the risk of nasopharyngeal carcinoma in the high background radiation areas of Yangjiang, China

International Nuclear Information System (INIS)

Zou Jianming; Sun Quanfu; Yuan Yongling

2003-01-01

Objective: To identify the major determinants of nasopharyngeal carcinoma (NPC) in the high-background radiation areas (HBRA) in Yangjiang, China. Methods: A nested case-control study was conducted based on 106517 subjects. 98 cases that died of NPC were detected during a follow-up program for 9 years. Univariate analysis and multivariate non-conditional logistic regression were used to analyze associations between the exposure factors and NPC. Results: Multivariate conditional logistic regression analysis revealed that education levels, salted fish intake, the history of chronic rhinitis and the family history of NPC were independent risk factors of NPC. Tobacco smoking and alcohol consumption 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 was 0.86 and 0.87, respectively. Conclusion: Salted fish intake was a strong risk factor of NPC. Education, the history of chronic rhinitis and the family history of NPC were also related to NPC risk. The exposure to high background radiation in HBRA of Yangjiang was not related to NPC risk with or without the adjustment for those major risk determinants of NPC

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

International Nuclear Information System (INIS)

Tao Zufan; Cha Yongru; Zhou Shunyuan

1989-01-01

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

Remedial action in areas of enhanced natural background radiation levels (with particular emphasis in areas with mineral sand mining residues)

International Nuclear Information System (INIS)

Swindon, T.N.

1985-01-01

In areas where individuals may receive doses from natural background sources which are higher than those received in areas of normal background radiation, it may be considered desirable that some remedial action be taken to reduce those doses. Contributions to these higher doses may be through high gamma ray fields from the ground or from the use of local building materials, the intake of food or water derived from the areas or of food covered with dust from the areas, the ingestion of dirt and the inhalation of dust, and radon or thoron. Guidelines for remedial action in areas where residues from mineral sand mining and processing have been deposited are given

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

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

International Nuclear Information System (INIS)

Zou Jianming; Zha Yongru; Sun Quanfu; Akiba, Suminori; Yuan Yongling; Tao Zufan; Wei Luxin; Sugahara, Tsutomu

2000-01-01

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 intake was

Estimation and comparison of baseline frequencies of micronuclei among the new-borns from natural high background radiation and control areas of Kerala coast in south India

International Nuclear Information System (INIS)

Das, Birajalaxmi; Karuppasamy, C.V.; Thampi, M.V.

1994-01-01

Based on the studies it is concluded that the elevated level of natural radiation has no significant effect of micronucleus formation in high background radiation area (HBRA) new-borns as compared to control area. It is also in agreement with the results of cytogenetic investigations on new-borns from HBRA and control area using chromosome aberration analysis method. The significance, if any, of the slightly lower micronuclei (MN) frequency observed in HBRA, is not clear at this stage. Further investigations on a larger number of new-borns from both the areas are necessary in order to draw firm conclusions. It appears that, this is the first attempt to estimate the baseline frequency of MN among the new-borns from a natural high background radiation area. (author). 9 refs

[Investigation of urinary cadmium reference of general population in two rural high background areas of soil cadmium and non-cadmium-polluted in China].

Science.gov (United States)

Han, Jingxiu; Li, Qiujuan; Yao, Dancheng; Zheng, Jiangang; Zhang, Wenli; Shang, Qi

2014-09-01

To study the reference of urinary. cadmium of the general population in rural high background areas of soil cadmium and non-cadmium contaminated in China. In rural high background areas of soil cadmium and non-cadmium contaminated, randomly selected non-occupational-cadmium exposed population 1134 people (male 519, female 615) with each gender and age groups, questionnaire surveyed and collected random urine. Urinary cadmium and urinary creatinine (Cr) concentration were tested, excluding urinary Cr 3 g/L. Analyze the impact factors of urinary cadmium and calculated 95% quantile (P,95 ) of urinary cadmium after correction by urinary Cr. Female median urinary cadmium was significantly higher than men, male smokers median urinary cadmium was significantly higher than male non-smokers (P 30 year-old. According to gender, and 15 -30, 30 years old, analysis the upper limit of cadmium in urine. The 95% upper limit of urinary cadmium of 30 year-old female (12.24 microg/gCr) was significantly higher than other populations ( population exceeded the upper limit (5 microg/gCr) of the occupational cadmium poisoning diagnostic criteria in China (GBZ 17-2002). In the two rural high background areas of soil cadmium and non-cadmium polluted , urinary cadmium reference of non-cadmium-occupational-exposed male is <9.0 microg/gCr, and female <13.0 microg/gCr.

Alterations in lipids & lipid peroxidation in rats fed with flavonoid rich fraction of banana (Musa paradisiaca) from high background radiation area.

Science.gov (United States)

Krishnan, Kripa; Vijayalakshmi, N R

2005-12-01

A group of villages in Kollam district of Kerala, southern part of India are exposed to a higher dose of natural radiation than global average. Yet no adverse health effects have been found in humans, animals and plants in these areas. The present study was carried out to understand whether radiation affects the quantity and quality of flavonoids in plants grown in this area of high radiation, and to assess the effect of feeding flavonoid rich fraction (FRF) of the two varieties of banana to rats on their biochemical parameters like lipids, lipid peroxides and antioxidant enzyme levels. A total of 42 albino rats were equally divided into 7 groups. Rats fed laboratory diet alone were grouped under group I (normal control). Groups II and V received flavonoid rich fraction (FRF) from the fruits of two varieties of Musa paradisiaca, Palayamkodan and Rasakadali respectively from normal background radiation area (Veli) and treated as controls. Rats of groups III and IV received FRF of Palayamkodan from high background radiation areas (HBRAs) - Neendakara and Karunagappally respectively while groups VI and VII received FRF of Rasakadali from HBRAs. At the end of the experimental period of 45 days, lipids, lipid peroxides and antioxidant enzymes from liver, heart and kidney were analyzed. FRF of Palayamkodan and Rasakadali varieties showed significant hypolipidaemic and antioxidant activities. But these activities were found to be lowered in plants grown in HBRAs, particularly in Karunagappally area. Of the two, Palayamkodan variety was more effective in reducing lipids and lipid peroxides. MDA and hydroperoxides were significantly diminished in rats given FRF of banana from Veli (control area) only. FRF from plants grown in HBRAs exerted inhibition in the activities of antioxidant enzymes in the liver of rats and this inhibitory effect was maximum in rats fed FRF from Karunagappally. Banana grown in HBRAs is of lower quality with less efficient antioxidant system

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

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

International Nuclear Information System (INIS)

Karam, P. Andrew; Mortazavi, S.M. Javad

2001-01-01

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 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 leukemia, breast and

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

International Nuclear Information System (INIS)

Zou Jianming; Sun Quanfu; Yuan Yongling

1999-01-01

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

Quantification of DNA repair capacity (DRC) in peripheral blood lymphocytes of individuals from natural high background radiation areas of Kerala, India

International Nuclear Information System (INIS)

Vivek Kumar, P.R.; Seshadri, M.

2011-01-01

Human populations residing in the coastal areas of Kerala from Neendakara in south to Purakkad in north receive high level natural background radiation primarily due to the presence of thorium ( 232 Th) in the monazite containing beach sand. This provides a unique opportunity to investigate the health effects of natural high level radiation on humans. Earlier studies from our laboratory in newborns for incidence of congenital malformations, structural and numerical chromosome aberrations failed to show any significant health or biological effects due to high level natural radiation exposure. The current study used alkaline single cell gel electrophoresis (comet) assay due to its sensitivity, speed, flexibility and low cost. Biological effects of low level natural radiation was studied by assessing individual's DNA Repair Capacity (DRC), which is essential for maintaining the genome integrity. DNA damage was estimated in terms of DNA strand breaks per million base pairs (SB/106 bp). In our earlier study using comet assay, DNA SBs increased with age in subjects from normal background radiation area (NBRA). However, significant inverse correlation was observed in subjects from high background radiation area (HBRA). Further, spontaneous DNA SBs in elderly subjects (? 41 years) from HBRA was significantly lower compared to the subjects from NBRA. The present study was carried out in 90 healthy adult male subjects of which, 63 subjects belonged to HBRA and 27 subjects from NBRA. The annual effective dose in HBRA subjects was 5.87 ± 4.17 mSv year-1 (Mean ± S.D., range 1.07-17.41) and in NBRA subjects was ? 1mSv year-1. Peripheral blood lymphocytes from these individuals were irradiated with 4Gy of 60 Co gamma rays (1.4Gy/minute, Low dose irradiator 2000, BRIT, India) and DNA repair was assessed at 30 minutes. As the results were not normally distributed, the data were log transformed to normalize variance. Regression analysis was carried out to determine the relative

Natural radioactivity and associated radiation characteristic of the new high background radiation area of lambwe east southern Kenya

International Nuclear Information System (INIS)

Achola, S.O.; Patel, J.P.; Angeyo, H.K.; Mustapha, A.O.

2010-01-01

Rocks and soils from a number of areas underlined by carbonatite rocks in Kenya have been associated with high levels of natural background radioactivity. People in such high background radiation areas (HBRA), are exposed to abnormally high annual absorbed dose (that have health implications) than the global normal 1 mSvyr-1. In this paper, results of field background radiation measurements, activity concentrations of primordial radionuclides in (mainly carbonatite rock and soil) matrices, and estimated annual external effective dose rates are presented for South and North Ruri hills in Lambwe East location of Suba District, which lies roughly between latitudes 0°30'S and 1°00'S, bounded on the east by longitude 34°30'E and on the west by the shores of Lake Victoria 16 and Winnam Gulf. Altitudes in the region range from about 1000 m on the shores of Lake Victoria to above 1800 m on top of the Ruri hills. The main geological features are carbonatite formations. Twenty one samples were analyzed using high-purity germanium (HPGe) gamma-ray spectrometer. The activity concentrations ranged 14.18 - 6559.99 Bqkg-1 (average: 1396.85 Bqkg-1) for Th-232; 2.73 - 499.24 Bqkg-1 (average: 178.69 Bqkg-1) for U-238; and 56.67 - 1454.73 Bqkg-1 (average: 508.67 Bqkg-1) for K-40. The variability in Th distribution could be due to another contributing factor apart from carbonatite: Homa hills geothermal field fluids might be responsible for delivery of Th to surface rocks; some hot spots have travertine deposits. Measured absorbed dose rates in air outdoors range 700 - 6000.00 nGyh-1 (mean: 2325.84 nGy h-1); assuming 0.4 occupancy factor, these values correspond to individual annual effective dose rates of 1.717 - 14.717 mSvyr-1 (mean: 5.705 mSv yr-1). Measured absorbed dose rates are higher than calculated values since they include the contribution of cosmic rays. The natural radioactivity is fractionated with higher levels in the soils than carbonatite rocks

An introductory overview of the epidemiological study on the population at the high background radiation areas in Yangjiang, China

International Nuclear Information System (INIS)

Wei Luxin; Sugahara, Tsutomu

2000-01-01

The epidemiological study on the residents of the high background radiation areas in Yangjiang, China was started by Chinese scientists in 1972 and continued until 1986. In 1991, Japanese scientists recognized the importance of the work and a joint feasibility study was conducted with revised protocols. The feasibility study matured to a cooperative project involving both Chinese and Japanese scientists in 1992, which currently is still in progress. The project was divide into three phases; the first being from 1992 to 1995, the second from 1995-1998 and the third from 1998 to 2001. The results of the first phase were reported previously in 1996. The present paper is a historical overview of the studies before the cooperation and the first two phases. Remarks are made on the detailed data on dosimetry, cytogenetic studies and cancer epidemiology of a series of the papers in this supplemental issue. Some problems such as paradoxical observations between cytogenetic results and cancer mortality, and the importance of the high background study in risk assessment are discussed. (author)

An introductory overview of the epidemiological study on the population at the high background radiation areas in Yangjiang, China

Energy Technology Data Exchange (ETDEWEB)

Wei Luxin [Ministry of Health, Beijing (China). Lab. of Industrial Hygiene; Sugahara, Tsutomu

2000-10-01

The epidemiological study on the residents of the high background radiation areas in Yangjiang, China was started by Chinese scientists in 1972 and continued until 1986. In 1991, Japanese scientists recognized the importance of the work and a joint feasibility study was conducted with revised protocols. The feasibility study matured to a cooperative project involving both Chinese and Japanese scientists in 1992, which currently is still in progress. The project was divide into three phases; the first being from 1992 to 1995, the second from 1995-1998 and the third from 1998 to 2001. The results of the first phase were reported previously in 1996. The present paper is a historical overview of the studies before the cooperation and the first two phases. Remarks are made on the detailed data on dosimetry, cytogenetic studies and cancer epidemiology of a series of the papers in this supplemental issue. Some problems such as paradoxical observations between cytogenetic results and cancer mortality, and the importance of the high background study in risk assessment are discussed. (author)

Epidemiology of non-syndromic cleft lip/palate in the high level natural background radiation areas (HLNRA) of the South west coast of India

International Nuclear Information System (INIS)

Jaikrishan, G.; Sudheer, K.R.; Andrews, V.J.; Koya, P.K.M.; Cheriyan, V.D.; Seshadri, M.

2010-01-01

All consecutive births in selected government hospitals in and around the high level natural background radiation areas (HLNRA) of Kerala were monitored for congenital malformations observable at birth since 1995. The HLNR area, with natural deposits of monazite sand containing thorium (8-10%) and Uranium (0.3%), is a coastal strip of land about 55 km in length and 0.5 km in breadth from Purakkad in the north in Alleppey district to Sakthikulangara in the south of Quilon district and is one among the most prominent background radiation areas of the world. Patchy and non-uniform distribution of Monazite sand causes wide variation in dose ranging from <1 to 45 mGy/year. High population density, limited migration, ethnic diversity, good literacy, health awareness, institutionalized births and acceptance of small family norm are some of the key features of the population. Areas with a mean radiation dose of more than 1.5 mGy/year were treated as HLNR areas and areas with a dose level of 1.5 mGy/year or less were treated as normal level radiation areas (NLNRA). A total of 134,178 newborns were monitored and non-syndromic cleft lip/palate (NSCLP) was detected in 143 newborns (1.07%). Cleft lip with cleft palate (59.4%) was more common than cleft lip (18.2%) or Cleft palate (22.4%) alone and 11.9% had other malformation(s) together with NSCLP. There was no evidence to suggest that NSFC was significantly associated with prevailing dose level of area of mother's residence, maternal age birth, gravida, ethnicity or consanguinity

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)

Deva Jayanthi, D.; Maniyan, C.G.; Perumal, S.

2011-01-01

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.

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.

Ingestion of polonium ((210)Po) via dietary sources in high background radiation areas of south India.

Science.gov (United States)

Arunachalam, Kantha Deivi; Baskaran, Kamesh Viswanathan; Rao, D D; Sathyapriya, R; Annamalai, Sathesh Kumar; Kuruva, Jaya Krishna; Hari, Shanmugamsundaram

2014-10-01

To study the distribution of Polonium ((210)Po) activity in dietary sources in the high background radiation zone of Puttetti in southern Tamil Nadu. (210)Po was analyzed in the food materials consumed by the male and female individual representatives living in the high background areas by 24-h Duplicate Diet Study (DDS) and Market Basket Study (MBS). The MBS was performed by collecting the food samples such as, cereals, fruits, leafy vegetables, roots and tubers, other vegetables, fish, meat and milk grown in the high background radiation zone of southern Tamil Nadu as a part of baseline study in this region. The DDS was done by collecting the food materials consumed including the beverages in 24 h from different age groups of male and female individuals living in the village of Puttetti. The intake and ingestion dose of the radionuclide (210)Po was estimated. The average concentration of (210)Po in DDS (n = 33) was found to be 74 mBq.kg(- 1) of fresh weight. The MBS was collected based on food consumption representing more than 85-95% of annual supply, and were divided into eight food groups. The average concentration of (210)Po in the eight food groups namely leafy vegetables was 2176 mBq.kg(- 1) (n = 3), vegetables 55 mBq.kg(- 1) (n = 10), roots and tubers 251 mBq.kg(- 1) (n = 4), fruits 65 mBq.kg(- 1) (n = 5), fish 345 mBq.kg(- 1) (n = 2), meat food 117 mBq.kg(- 1) (n = 3), milk 20 mBq.kg(- 1) (n = 1) and cereal 290 (n = 1) mBq.kg(- 1) of fresh weight, respectively. The annual intake and ingestion dose due to (210)Po was estimated by DDS and MBS in adults, adolescents and children. The overall results showed that the MBS was moderately higher than the DDS in all age groups. Moreover, a DDS approach may even be more realistic, as cooked foodstuffs are used for dietary exposure assessment. The study confirms that the current levels of (210)Po do not pose a significant radiological risk to the local inhabitants.

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)

Jiang Tao; Hayata, I.; Wang Cunyan

1999-01-01

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 (R 2 = 0.7814) for age and Y 0.0156X + 0.5715 (R 2 = 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

Radon exhalation rate and natural radionuclide content in building materials of high background areas of Ramsar, Iran.

Science.gov (United States)

Bavarnegin, E; Fathabadi, N; Vahabi Moghaddam, M; Vasheghani Farahani, M; Moradi, M; Babakhni, A

2013-03-01

Radon exhalation rates from building materials used in high background radiation areas (HBRA) of Ramsar were measured using an active radon gas analyzer with an emanation container. Radon exhalation rates from these samples varied from below the lower detection limit up to 384 Bq.m(-2) h(-1). The (226)Ra, (232)Th and (40)K contents were also measured using a high resolution HPGe gamma- ray spectrometer system. The activity concentration of (226)Ra, (232)Th and (40)K content varied from below the minimum detection limit up to 86,400 Bq kg(-1), 187 Bq kg(-1) and 1350 Bq kg(-1), respectively. The linear correlation coefficient between radon exhalation rate and radium concentration was 0.90. The result of this survey shows that radon exhalation rate and radium content in some local stones used as basements are extremely high and these samples are main sources of indoor radon emanation as well as external gamma radiation from uranium series. Copyright © 2012 Elsevier Ltd. All rights reserved.

Background radioactivity in the monazite areas of Kerala, India

International Nuclear Information System (INIS)

Soman, S.D.

1982-07-01

External radiation exposure measurements were carried out with natural CaF 2 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.) [de

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

International Nuclear Information System (INIS)

Mamontova, Elena A.; Mamontov, Alexander A.; Tarasova, Eugenia N.; Kuzmin, Mikhail I.; Ganchimeg, Darmaa; Khomutova, Marina Yu.; Gombosuren, Odontuya; Ganjuurjav, Erdenebayasgalan

2013-01-01

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

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

International Nuclear Information System (INIS)

Huang Jialin; Zha Yongru; Guo Yicao

1985-01-01

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

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

International Nuclear Information System (INIS)

Yuan Yongling

2000-01-01

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

Background radiation study of Offa industrial area of Kwara State ...

African Journals Online (AJOL)

A study of the external background radiation in Offa industrial area of Kwara State is hereby reported. An in-situ measurement using two Digilert radiation monitors at five different stations were carried out. A mean exposure rate of 0.0132mR/hr, which represents 20% elevation from the standard background radiation, was ...

A prospective study on congenital malformations in the high background radiation areas of Kerala

International Nuclear Information System (INIS)

Jaikrishan, G.; Sudheer, K.R.; Andrews, V.J.; Koya, P.K.M.; Cheriyan, V.D.; Seshadri, M.

2010-01-01

Hospital based epidemiological study on congenital anomalies carried out in the high level natural radiation (HLNR) areas of southern Kerala since 1995 to assess the hereditary effects, if any, of HLNR is reported here. Thorium, Uranium to a limited extent, and corresponding decay products in the natural deposits of monazite sand is the source of radiation. HLNR and normal level natural radiation (NLNR) areas are interwoven due to the patchy and non-uniform distribution of monazite in the region. Areas with a mean dose of more than 1.5 mGy/year were treated as HLNR areas and those with 1.5 mGy/year or less, as NLNR. High population density, limited migration, ethnic diversity, good literacy, health awareness, institutionalized births and acceptance of small family norm are some of the key features of the population. The comparison of individual malformation in HLNR and NLNR areas are presented and efforts are on to accrue sufficient sample size to enable the comparison

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

Energy Technology Data Exchange (ETDEWEB)

Abdel-Rahman Al-Shakhrah, Issa [Department of Physics, University of Jordan, Queen Rania Street, Amman (Jordan)], E-mail: issashak@yahoo.com

2009-04-15

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

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

International Nuclear Information System (INIS)

Abdel-Rahman Al-Shakhrah, Issa

2009-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Jialin, Huang; Yongru, Zha; Yicao, Guo

1985-04-01

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/sup -6/ g/kg, and those of radium-226, radium-228, lead-210 and polonium-210 are of the order of 10/sup -11/ Ci/kg. The highest level is 9.30 +- 0.30 x 10/sup -11/ Ci/kg (lead-210), and the lowest is 3.99 +- 0.20 x 10/sup -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/sup -11/ Ci/kg, 10.4 times higher than the limit. The transfer of all the 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.

Non-cancer disease mortality among inhabitants in the high background radiation area of Yangjiang, China (1979-1998)

International Nuclear Information System (INIS)

Sun Quanfu; Akiba, Suminori; Zou Jianming

2008-01-01

Much is still unknown about the health effects of low-level radiation on human health, particularly on the risk of non-cancer diseases. A review by Radiation Effects Research Foundation (RERF) scientists has concluded that the association of atomic-bomb radiation and cardiovascular disease (CVD) is almost certain since the relationship was shown by incidence and prevalence studies of various endpoints of atherosclerosis. In addition to the studies of atomic bomb survivors, the association of CVD with radiation exposure was observed in several other studies, including the follow-up study of patients treated for Hodgkin lymphoma, ankylosing spondilitis, peptic ulcer and scoliosis as well as nuclear workers. The inhabitants in the high background radiation area (HBRA) of Yangjiang, Guangdong Province, China receive the external radiation doses of 1.33 mSv in excess every year, mainly from exposure to terrestrial gamma ray, when compared to the residents in the neighboring control area (CA). Our most recent analysis of cancer mortality among residents in the HBRA and the CA showed no evident difference between the two areas. It should be of note that the crude cancer mortality rate in the study population was 60/100,000 person-years, which is much lower than cancer mortality in developed countries. On the other hand, non cancer deaths accounted for 90% of all deaths. In this report, we present the results of mortality analysis for non-cancer diseases during the period 1979-1998. (author)

Design and environmental applications of an ultra-low-background, high-efficiency intrinsic Ge gamma-ray spectrometer

International Nuclear Information System (INIS)

Wogman, N.A.

1981-04-01

A coincidence shielded intrinsic Ge gamma-ray spectrometer incorporating a 25% efficient, high resolution coaxial diode inside a 30 cm diameter NaI(Tl) shield is described. System design eliminates the major cause of background and minimizes cosmic-ray created background events through the use of electronic means. The system provides a peak-to-Compton ratio of greater than 1000 to 1 for 137 Cs and high sensitivity for both low and high level radionuclide measurements. At 3 MeV the background is 0.000058 counts per minute per keV. At 1 MeV it is 0.00048 counts per minute per keV, and at 0.5 MeV it is 0.0045 counts per minute per keV. Traces of primordial radionuclides create background events such as at 2.614 MeV (0.016 counts per minute total peak area), at 2.448 MeV (0.0058 counts per minute per total peak area), and at 2.204 MeV (0.023 counts per minute per total peak area). The system is discussed with respect to its background design, methods to improve its design, and its application to measurements of neutron activated and environmental materials problems

Reanalysis of noncancer deaths (1987-1995) among residents in high background radiation area of Yangjiang, China

International Nuclear Information System (INIS)

Zou Jianming; Zha Yongru; Sun Quanfu; Liu Yusheng; Li Jia; Tao Zufan; Wei Lvxin

2004-01-01

Objective: To further analyze non-cancer mortality rates and relevant influencing factors among the residents in high background radiation area(HBRA) and its control area (CA). Methods: The data for the period 1987-1995 were obtained from a fixed cohort by prospective survey. The mortality investigation on the spot consisted of two steps, i.e. the follow-up of the cohort members and the ascertainment of causes of death. On the basis of the hamlet-specific average of annual external dose, the cohort members were classified into four groups for internal comparison: high, medial and low dose groups in HBRA and control group in CA. Relative risk (RR), excess relative risk(ERR/Sv) and its 95% confidence interval (CI) were estimated using AMFIT program in Epicure. Results: During the period 1987-1995, the noncancer mortality in HBRA increased by 9% compared with that in the control group, and the relative risk of noncancer diseases was 1.09 (P=0.01), indicating a statistically significant excess mortality in the HBRA. The significantly increased noncancer death was caused by diseases of digestive system, with a RR of 1.46(P=0.006); the relative risk of chronic liver diseases including cirrhosis was 1.98(P=0.004). The significantly decreased noncancer death rates were observed for the infectious and parasitic diseases, the RR being 0.81(P=0.04); for pulmonary tuberculosis, RR 0.58(P<0.001). The homogeneity tests of risks across the four dose-groups revealed that the RRs for diseases of digestive system and for liver cirrhosis were significantly different, P values being 0.01 and 0.04, respectively. The ERR(95% CI)/Sv for diseases of digestive system and liver cirrhosis were 2.18(0.22, 7.64) and 10.94(1.34, NA), respectively. Conclusion: The death rates from diseases of digestive system, especially chronic liver diseases and cirrhosis were statistically significantly higher, and that from pulmonary tuberculosis was significantly lower in the HBRA than those in the control

Evaluation of thyroid function in female subjects living in the high natural background radiation area of Karunagappally, Kerala

International Nuclear Information System (INIS)

Sreekumar, A.; Nair, Raghu Ram K.; Jayalakshmi, P.; Sebastian, P.; Akiba, S.

2010-01-01

Radiation exposure has been reported to cause non cancer thyroid abnormalities like diffuse goiter and thyroid nodules. The present study was undertaken to see if there are any morphological and functional changes taking place in the thyroid due to chronic low level radiation exposure. 257 female subjects living in the four high background radiation panchayats of Chavara, Neendakara, Alappad and Panmana were selected for the study after getting informed consent. 5 ml of blood was drawn from these subjects for assessing thyroid function. The subjects were all staying in the same area since their birth and had not moved out for more than one year at a stretch. The average age of the subjects was 40.5y with a range of 17-66y. The cumulative dose had a mean of 226.3 mGy and a range of 20.6-937.8 mGy. 95 subjects from the low background area of Oachira and Thevalakkara were selected as controls in the age group of 18-63y with a mean age of 47.1y. The mean cumulative dose of this group was 35.9 mGy with a minimum of 5.3 mGy and a maximum of 106.8 mGy. 5 ml blood was collected from these subjects for thyroid function studies. All the subjects underwent ultrasound examination of the thyroid using a 10 MHz frequency linear probe. The following parameters were studied to assess thyroid function: Free T4, TSH, Antithyroglobulin antibody (ATG), Parathyroid hormone. Ultrasound images showed the following common features: Normal - 171, Suggestive of Thyroiditis - 106, Multinodular Goitre - 63, Diffuse Goitre - 5, Solitary Nodule - 31. 73 subjects had elevated TSH and 190 subjects had raised ATG. A significant numbers of subjects had features of thyroiditis. A comparative evaluation with control subjects will be done to assess its significance with reference to cumulative dose

Background area effects on feature detectability in CT and uncorrelated noise

International Nuclear Information System (INIS)

Swensson, R.G.; Judy, P.F.

1987-01-01

Receiver operating characteristic curve measures of feature detectability decrease substantially when the surrounding area of uniform-noise background is small relative to that of the feature itself. The effect occurs with both fixed and variable-level backgrounds, but differs in form for CT and uncorrelated noise. Cross-correlation image calculations can only predict these effects by treating feature detection as the discrimination of a local change (a ''feature'') from the estimated level of an assumed-uniform region of background

Estimation of thorium intake due to consumption of vegetables by inhabitants of high background radiation area by INAA

International Nuclear Information System (INIS)

Sathyapriya, R.S.; Suma Nair; Prabhath, R.K.; Madhu Nair; Rao, D.D.

2012-01-01

A study was conducted to estimate the thorium concentration in locally grown vegetables in high background radiation area (HBRA) of southern coastal regions of India. Locally grown vegetables were collected from HBRA of southern coastal regions of India. Thorium concentration was quantified using instrumental neutron activation analysis. The samples were irradiated at CIRUS reactor and counted using a 40% relative efficiency HPGe detector coupled to MCA. The annual intake of thorium was evaluated using the consumption data provided by National Nutrition Monitoring Board. The daily intake of 232 Th from the four food categories (green leafy vegetables, others vegetables, roots and tubers, and fruits) ranged between 0.27 and 5.352 mBq d -1 . The annual internal dose due to ingestion of thorium from these food categories was 46.8 x 10 -8 for female and 58.6 x 10 -8 Sv y -1 for male. (author)

Radiation exposure map based on fuzzy logic for the representation of areas with high natural background

International Nuclear Information System (INIS)

Vasconcelos, Wagner Eustaquio de; Lira, Carlos Alberto Brayner de Oliveira

2009-01-01

The identification of areas with high concentrations of natural radionuclides is an important task in classifying these areas in relation to the health risk for residents in the region. The aim of this work is to identify areas of high exposure to nuclear radiation using a geographic representation based on the theory of fuzzy sets. Radiometric data obtained from previous works developed in a region of high concentrations in natural uranium were used to create a fuzzy map of the local radiation levels. During the image processing, a nonlinear filter was applied to eliminate noise i.e. to reduce isolated pixels that would eventually cause major uncertainties in the results. A resulting image was geographically positioned (WGS40) and obtained in gray scale. This image was fuzzified for membership functions that represent linguistic variables as low exposure, medium exposure and high exposure. After representing the membership grade in a RGB (red, green and blue) image it was possible to visualize the radiation level in the area of exposure. When compared to data from the region, results demonstrated the good efficiency of the technique here employed for the representation of areas with high radioactivity levels. The image obtained also provided important information about those areas where exposure to radiation is more pronounced. Hence, the fuzzy map can be applied in decision-making of experts when a risk situation is identified. (author)

Radon exhalation rate and natural radionuclide content in building materials of high background areas of Ramsar, Iran

International Nuclear Information System (INIS)

Bavarnegin, E.; Fathabadi, N.; Vahabi Moghaddam, M.; Vasheghani Farahani, M.; Moradi, M.; Babakhni, A.

2013-01-01

Radon exhalation rates from building materials used in high background radiation areas (HBRA) of Ramsar were measured using an active radon gas analyzer with an emanation container. Radon exhalation rates from these samples varied from below the lower detection limit up to 384 Bq.m −2 h −1 . The 226 Ra, 232 Th and 40 K contents were also measured using a high resolution HPGe gamma- ray spectrometer system. The activity concentration of 226 Ra, 232 Th and 40 K content varied from below the minimum detection limit up to 86,400 Bq kg −1 , 187 Bq kg −1 and 1350 Bq kg −1 , respectively. The linear correlation coefficient between radon exhalation rate and radium concentration was 0.90. The result of this survey shows that radon exhalation rate and radium content in some local stones used as basements are extremely high and these samples are main sources of indoor radon emanation as well as external gamma radiation from uranium series. -- Highlights: ► In the selection process of local samples, portable scintillometer (NaI) was used. ► The activity concentration of 226 Ra varied from below the MDL up to 86400 Bq kg −1 . ► The activity concentration of 232 Th varied from below the MDL up to 187 Bq kg −1 . ► The activity concentration of 40 K varied from below the MDL up to 1350 Bq kg −1

Health effects in residents of regions with high background radiation

International Nuclear Information System (INIS)

Hanson, G.P.

1984-01-01

Possible health problems created by high natural levels of background radiation are hard to detect, partly because the health problems involved would exist to some degree irrespective of radiation exposure, partly because other factors affect the incidence of such problems, and partly because the differences between normal background radiation levels and radiation levels found in most high-radiation areas are not extreme. Nevertheless, the need to know about such health effects is evident, and so various studies conducted over the past 30 years have sought to determine whether those effects exist and what they are. Overall, however, the fragmentary and uncertain nature of many of these findings makes it hard to draw firm conclusions about the health risks involved or the desirability of countermeasures. So despite considerable efforts and some progress over the past three decades, the need for a clear quantitative assessment of the consequences is as great as ever

Sensitivity to Antibiotics of Bacteria Exposed to Gamma Radiation Emitted from Hot Soils of the High Background Radiation Areas of Ramsar, Northern Iran

Directory of Open Access Journals (Sweden)

Seyed Mohammad Javad Mortazavi

2017-04-01

Full Text Available Background: Over the past several years our laboratories have investigated different aspects of the challenging issue of the alterations in bacterial susceptibility to antibiotics induced by physical stresses. Objective: To explore the bacterial susceptibility to antibiotics in samples of Salmonella enterica subsp. enterica serovar Typhimurium (S. typhimurium, Staphylococcus aureus, and Klebsiella pneumoniae after exposure to gamma radiation emitted from the soil samples taken from the high background radiation areas of Ramsar, northern Iran. Methods: Standard Kirby-Bauer test, which evaluates the size of the zone of inhibition as an indicator of the susceptibility of different bacteria to antibiotics, was used in this study. Results: The maximum alteration of the diameter of inhibition zone was found for K. pneumoniae when tested for ciprofloxacin. In this case, the mean diameter of no growth zone in non-irradiated control samples of K. pneumoniae was 20.3 (SD 0.6 mm; it was 14.7 (SD 0.6 mm in irradiated samples. On the other hand, the minimum changes in the diameter of inhibition zone were found for S. typhimurium and S. aureus when these bacteria were tested for nitrofurantoin and cephalexin, respectively. Conclusion: Gamma rays were capable of making significant alterations in bacterial susceptibility to antibiotics. It can be hypothesized that high levels of natural background radiation can induce adaptive phenomena that help microorganisms better cope with lethal effects of antibiotics.

China's deep geological disposal program for high level radioactive waste, background and status 1998

International Nuclear Information System (INIS)

Ju Wang; Xu Guoqing; Guo Yonghai

2001-01-01

This paper presents the background and progress made in the study of China's high level radioactive waste, including site screening, site evaluation, the study on radionuclide migration, bentonite, natural analogue studies, and performance assessment, etc. The study on Beishan area, the potential area for China's geological repository, is also presented in this paper. (author)

Overcoming High Energy Backgrounds at Pulsed Spallation Sources

CERN Document Server

Cherkashyna, Nataliia; DiJulio, Douglas D.; Khaplanov, Anton; Pfeiffer, Dorothea; Scherzinger, Julius; Cooper-Jensen, Carsten P.; Fissum, Kevin G.; Ansell, Stuart; Iverson, Erik B.; Ehlers, Georg; Gallmeier, Franz X.; Panzner, Tobias; Rantsiou, Emmanouela; Kanaki, Kalliopi; Filges, Uwe; Kittelmann, Thomas; Extegarai, Maddi; Santoro, Valentina; Kirstein, Oliver; Bentley, Phillip M.

2015-01-01

Instrument backgrounds at neutron scattering facilities directly affect the quality and the efficiency of the scientific measurements that users perform. Part of the background at pulsed spallation neutron sources is caused by, and time-correlated with, the emission of high energy particles when the proton beam strikes the spallation target. This prompt pulse ultimately produces a signal, which can be highly problematic for a subset of instruments and measurements due to the time-correlated properties, and different to that from reactor sources. Measurements of this background have been made at both SNS (ORNL, Oak Ridge, TN, USA) and SINQ (PSI, Villigen, Switzerland). The background levels were generally found to be low compared to natural background. However, very low intensities of high-energy particles have been found to be detrimental to instrument performance in some conditions. Given that instrument performance is typically characterised by S/N, improvements in backgrounds can both improve instrument pe...

Study of thorium uptake by inhabitants of a high background radiation area

International Nuclear Information System (INIS)

Melo, D.R.; Lipsztein, J.L.; Juliao, L.M.Q.C.; Lourenco, M.C.; Lauria, D.

2002-01-01

Buena, located in the North of Rio de Janeiro, is characterized by its high natural radiation background, due to large deposits of monazite sand. The foodstuffs consumed by the population are basically composed of local products, which contain significant amounts of thorium. The analysis of complete cooked meals have shown an average daily intake of 18 mBq.d -1 of 232 Th and 189 mBq.d -1 of 228 Th. The average urine to feces ratio of 232 Th from samples of volunteers was found equal to 7.5x10 -2 . The comparison of the experimental data with the predicted urine to feces ratios derived using the biokinetic model for thorium described by the ICRP publication 69 and simulating inhalation and ingestion separately, lead to the conclusion that the thorium intake is a combination of inhalation and ingestion. The clearance rate of thorium of monazite in lungs has apparently behaved as Type M compound. Inhalation is the biggest contributor for the committed effective dose due to thorium internal exposure. (author)

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)

Aliyu, Abubakar Sadiq; Ramli, Ahmad Termizi

2015-01-01

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

Analysis of data (1987-1995) from investigation of cancer mortality in high background radiation area of Yangjiang, China

International Nuclear Information System (INIS)

Tao Zufan; Akiba, S.; Zha Yongru

1999-01-01

Objective: This investigation is a special project of High Background Radiation Research Group. The objective of the cancer mortality study in the high background radiation area (HBRA) of Yangjiang, China, which was started in 1972, was to estimate cancer risk associated with the low level radiation exposure of average annual effective dose of 6.4 mSv in HBRA. Since 1991, the study has been conducted collaboratively by Chinese and Japanese scientists with the purpose of accumulating further person years (Pyr) of observation for improving the statistical precision and seeing the reproducibility of the previous results. Methods: The cancer mortality data of 1987-1995 covered in the current cooperative study were collected by a retrospective and/or prospective survey from a fixed cohort. The mortality investigation on the spot consisted of two steps, i.e. the follow-up of members in the cohort and the ascertainment of the death causes. Based on the hamlet-specific average annual external dose, the members of the cohort in HBRA were classified into three groups: high, medial and low dose groups. Risk comparisons between each of the three dose groups with the control group from control area (CA) were conducted by means of relative risk (RR). The RR and the excess relative risk coefficient (ERR per sievert) and their y 95% confidence interval (CI) were estimated using AMFIT program in Epicure. Results: During the period 1987-1995, there were 5161 total deaths and 557 cancer deaths among 926238 Pyr at risk in the cohort of 106517 subjects. The RR (95% CI) adjusted for sex and age group for all cancers of whole HBRA was 0.96 (0.80-1.15). As for the site-specific cancer of whole HBRA, the RRs for leukemia, cancers of nasopharynx, esophagus and intestine were larger than one, while the RRs for cancers of stomach, liver, lungs, female breast, thyroid and lymphoma were less than one. However, all of them were not statistically different from one (P>0.05 for all). The

Profiles of doses to the population living in the high background radiation areas in Kerala, India

Energy Technology Data Exchange (ETDEWEB)

Chougaonkar, M.P. E-mail: mpckar@hotmail.com; Eappen, K.P.; Ramachandran, T.V.; Shetty, P.G.; Mayya, Y.S.; Sadasivan, S.; Venkat Raj, V

2004-07-01

A sample study of the profiles of radiation exposures to the populations living in the high background radiation areas (HBRAs) of the monazite-bearing region in Kerala, India, has been conducted by monitoring 200 dwellings selected from two villages in this region. Each of these dwellings was monitored for 1 year and the study lasted for a period of 2 years. The indoor gamma ray dose measurements were carried out using thermo luminescent dosimeters (TLDs) and the inhalation doses due to radon, thoron and their progenies were monitored using solid-state nuclear track detector (SSNTD) based twin-cup dosimeters. Outdoor gamma ray dose measurements were carried out using Geiger Muller (GM) tube based survey meters. Annual effective doses were computed, using occupancy factors of 0.8 and 0.2, respectively, for indoor and outdoor, by adding the three components. Occupants of 41.6% of the houses surveyed were observed to receive the annual effective doses ranging between 0.5 and 5 mSv/a, 41.6% between 5 and 10 mSv/a, 10.2% between 10 and 15 mSv/a and 6.6% greater than 15 mSv/a. The inhalation component was generally smaller than the external gamma ray component and on an average it was found to constitute about 30% of the total dose. The paper presents the details of the methodology adopted and the analysis of the results.

Database on epidemiological survey in high background radiation research

International Nuclear Information System (INIS)

Zhou Sunyuan; Guo Furong; Liu Yusheng

1992-01-01

In order to store and check the data of the health survey in high background radiation area (HBRA) and control area in Guangdong Province, and to use these data in future, three databases were set up by using RBASE 5000 database software. (1) HD: the database based on the household registers especially established for the health survey from 1979 to 1986, covering more than 160000 subjects and 2200000 data. (2) DC: the database based on the registration cards of deaths from cancers and all other diseases during the period of 1975-1986 including more than 10000 cases and 260000 data. (3) MCC: the database for the case-control study on mutation-related factors for four kinds of cancers (liver, stomach, lung cancers and leukemia), embracing 626 subjects and close to 90000 data. The data in the databases were checked up with the original records and compared with the manual analytical results

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

International Nuclear Information System (INIS)

Lu Xue; Feng Jiangbing; Chen Deqing; Liu Qingjie; Cha Yongru; Zou Jianming

2008-01-01

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)

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

Science.gov (United States)

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

2015-09-01

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

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)

Sun Quanfu; Tao Zufan; Yuan Yongling; Zou Jianming; Cha Yongru; Jian Yuannu; Wei Luxin; Akiba, S.

2002-01-01

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

Environmental 238U and 232Th concentration measurements in an area of high level natural background radiation at Palong, Johor, Malaysia.

Science.gov (United States)

Ramli, A Termizi; Hussein, A Wahab M A; Wood, A Khalik

2005-01-01

Concentrations of uranium-238 and thorium-232 in soil, water, grass, moss and oil-palm fruit samples collected from an area of high background radiation were determined using neutron activation analysis (NAA). U-238 concentration in soil ranged from 4.9 mg kg(-1) (58.8 Bq kg(-1)) to 40.4 mg kg(-1) (484.8 Bq kg(-1)), Th-232 concentration ranged from 14.9 mg kg(-1) (59.6 Bq kg(-1)) to 301.0 mg kg(-1) (1204 Bq kg(-1)). The concentration of U-238 in grass samples ranged from below the detection limit to 0.076 mg kg(-1) (912 mBq kg(-1)), and Th-232 ranged from 0.008 mg kg(-1) (32 mBq kg(-1)) to 0.343 mg kg(-1) (1.372 Bq kg(-1)). U-238 content in water samples ranged from 0.33 mg kg(-1) (4.0 Bq L(-1)) to 1.40 mg kg(-1) (16.8 Bq L(-1)), and Th-232 ranged from 0.19 mg kg(-1) (0.76 Bq L(-1)) to 0.66 mg kg(-1) (2.64 Bq L(-1)). It can be said that the concentrations of environmental U-238 and Th-232 in grass and water samples in the study area are insignificant. Mosses were found to be possible bio-radiological indicators due to their high absorption of the heavy radioelements from the environment.

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

International Nuclear Information System (INIS)

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

2000-01-01

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

Sensitivity to Antibiotics of Bacteria Exposed to Gamma Radiation Emitted from Hot Soils of the High Background Radiation Areas of Ramsar, Northern Iran.

Science.gov (United States)

Mortazavi, Seyed Mohammad Javad; Zarei, Samira; Taheri, Mohammad; Tajbakhsh, Saeed; Mortazavi, Seyed Alireza; Ranjbar, Sahar; Momeni, Fatemeh; Masoomi, Samaneh; Ansari, Leila; Movahedi, Mohammad Mehdi; Taeb, Shahram; Zarei, Sina; Haghani, Masood

2017-04-01

Over the past several years our laboratories have investigated different aspects of the challenging issue of the alterations in bacterial susceptibility to antibiotics induced by physical stresses. To explore the bacterial susceptibility to antibiotics in samples of Salmonella enterica subsp. enterica serovar Typhimurium ( S. typhimurium ), Staphylococcus aureus , and Klebsiella pneumoniae after exposure to gamma radiation emitted from the soil samples taken from the high background radiation areas of Ramsar, northern Iran. Standard Kirby-Bauer test, which evaluates the size of the zone of inhibition as an indicator of the susceptibility of different bacteria to antibiotics, was used in this study. The maximum alteration of the diameter of inhibition zone was found for K. pneumoniae when tested for ciprofloxacin. In this case, the mean diameter of no growth zone in non-irradiated control samples of K. pneumoniae was 20.3 (SD 0.6) mm; it was 14.7 (SD 0.6) mm in irradiated samples. On the other hand, the minimum changes in the diameter of inhibition zone were found for S. typhimurium and S. aureus when these bacteria were tested for nitrofurantoin and cephalexin, respectively. Gamma rays were capable of making significant alterations in bacterial susceptibility to antibiotics. It can be hypothesized that high levels of natural background radiation can induce adaptive phenomena that help microorganisms better cope with lethal effects of antibiotics.

Study of cancer mortality among inhabitants in the high background radiation area of Yangjiang, China (1979-1998)

International Nuclear Information System (INIS)

Tao Zufan; Sun Quanfu; Li Jia; Liu Yusheng; Wei Lvxin; Zou Jianming; Zha Yongru; Yuan Yongling

2004-01-01

Objective: The objective of the study is to explore cancer risk associated with the low-level radiation exposure of average annual effective dose of 6.4 mSv occurring in the high background radiation area (HBRA) in Yangjiang of Guangdong Province, China. Methods: The data of cancer mortality for period of 1979-1986 were collected in prospective follow-up survey of dynamic populations and those of 1987-1998 were obtained from a fixed cohort in the same method. Record linkage was used to combine the two data sets. The external dose received by the inhabitants was estimated on the basis of hamlet-specific environmental doses and sex-age-specific occupancy factors, and the fixed values of internal dose regardless of sex and age was assumed. Relative risk (RR) and excess relative risk coefficient (ERR/Sv) and their 95% confidence interval (CI) were calculated using the AMFIT in Epicure. Results: During the period of 1979-1998, the follow-up for 125 079 subjects accumulated 1 992 940 person-years and identified 12 444 deaths, including 1202 cancer deaths. The RR of mortality of all cancers in whole HBRA was 1.00 (95% CI, 0.89-1.14) showing no statistical difference between the HBRA and the control area (CA). The RRs of all cancers in low, intermediate and high dose groups in the HBRA did not show statistical difference from the control group, either. The region (Yangdong and Yangxi) and the follow-up period(1979-1986 and 1987-1998) did not evidently modify the results, and the restriction of cancer cases to those with pathology information made no statistically significant change in RRs. In site-specific cancer analysis, only the RR of esophageal cancer showed statistical excess in the HBRA, the others did not show statistical difference between the HBRA and the CA. The comparison of RRs of site-specific cancer mortality among different dose groups and the dose-response analysis of site-specific cancer mortality related to cumulative individual lifetime dose did not give

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

Gachin dwellings on a hot area, but with normal background

International Nuclear Information System (INIS)

Bahreyni Toosi, M.; Hagh Parast, M.

2006-01-01

Full text of publication follows: General population, everywhere in the world is exposed to a small dose of ionizing radiation from natural sources. Stochastic effects such as cancer and genetic disorders are caused when living creatures are exposed to low doses. In many countries, intensive studies have been carried out to establish natural back ground radiation in general, and also its significant components such as indoor and out door gamma radiation as well as radon contribution. Until 1996 sporadic studies had been carried out in Iran to assess background radiation in some area susceptible to high levels of radiation. Since 1996 M. T. Bahreyni Toossi and co-workers have measured environmental gamma radiation out- door and in-door for a vast area covering several provinces to establish the environmental gamma radiation level map of Iran. So far, Khorasan, Mazandaran, Kurdestan, Kerman and Bushehr counties have been investigated. In our latest project of these kind two counties, Sistan Baluchestan and Hormozgan in the south and south east Iran were studied. Gachin, a village located in south west Bandar Abbass had already been recognized as a high level natural back ground radiation with possible deposit of uranium. Therefore particular attention was paid to this village with some 3000 populations. Out door environmental radiation were measured for all 16 towns. In each town 5 stations were selected similar to those in previous studies i.e. one station at the town center and four station at the marginal area of the town along the four main geographical directions, i.e: north, south, east and west. Dose rates were measured over one minute interval for one hour. Mean of 60 individual measurements were taken as average dose rate for the selected station. In order to assess additional risk to Gachin inhabitants, in -door measurements were carried out inside 115 dwelling selected randomly. To measure environmental gamma radiation an environmental radiation meter type

Gachin dwellings on a hot area, but with normal background

Energy Technology Data Exchange (ETDEWEB)

Bahreyni Toosi, M.; Hagh Parast, M. [Mashhad Univ. of Medical Sciences, Medical Physics Dep., Faculty of Medicine (Iran, Islamic Republic of)

2006-07-01

Full text of publication follows: General population, everywhere in the world is exposed to a small dose of ionizing radiation from natural sources. Stochastic effects such as cancer and genetic disorders are caused when living creatures are exposed to low doses. In many countries, intensive studies have been carried out to establish natural back ground radiation in general, and also its significant components such as indoor and out door gamma radiation as well as radon contribution. Until 1996 sporadic studies had been carried out in Iran to assess background radiation in some area susceptible to high levels of radiation. Since 1996 M. T. Bahreyni Toossi and co-workers have measured environmental gamma radiation out- door and in-door for a vast area covering several provinces to establish the environmental gamma radiation level map of Iran. So far, Khorasan, Mazandaran, Kurdestan, Kerman and Bushehr counties have been investigated. In our latest project of these kind two counties, Sistan Baluchestan and Hormozgan in the south and south east Iran were studied. Gachin, a village located in south west Bandar Abbass had already been recognized as a high level natural back ground radiation with possible deposit of uranium. Therefore particular attention was paid to this village with some 3000 populations. Out door environmental radiation were measured for all 16 towns. In each town 5 stations were selected similar to those in previous studies i.e. one station at the town center and four station at the marginal area of the town along the four main geographical directions, i.e: north, south, east and west. Dose rates were measured over one minute interval for one hour. Mean of 60 individual measurements were taken as average dose rate for the selected station. In order to assess additional risk to Gachin inhabitants, in -door measurements were carried out inside 115 dwelling selected randomly. To measure environmental gamma radiation an environmental radiation meter type

Single-photon detector operating under extremely high background photon flux conditions

International Nuclear Information System (INIS)

Prochazka, Ivan; Sopko, Bruno; Blazej, Josef

2009-01-01

We are reporting our results in research and development in the field of avalanche semiconductor single-photon detectors and their application. Our goal was a development of a solid-state photon-counting detector capable of high-precision photon arrival time tagging in extremely harsh operating conditions. The background photon flux exceeding 10 9 photons per second hitting the detector active area should not avoid the useful signal detection and recognition on the signal level of units of photons per second. This is background photon flux about two orders of magnitude higher than what the conventional solid-state photon counters accept. The detection timing resolution should be better than 100 ps and the delay stability should be on picosecond level. We have developed and tested the active quenched and gated avalanche structure on silicon providing the required features in connection with the K14 detection chips. The detector is capable of gated operation under the conditions of background photon flux of 5x10 9 photons per second. The operational detector tolerates long term exposures to the input photon flux exceeding 10 15 photons (>1 mW) per second without damage.

Objectively assessed recess physical activity in girls and boys from high and low socioeconomic backgrounds.

Science.gov (United States)

Baquet, Georges; Ridgers, Nicola D; Blaes, Aurélie; Aucouturier, Julien; Van Praagh, Emmanuel; Berthoin, Serge

2014-02-21

The school environment influences children's opportunities for physical activity participation. The aim of the present study was to assess objectively measured school recess physical activity in children from high and low socioeconomic backgrounds. Four hundred and seven children (6-11 years old) from 4 primary schools located in high socioeconomic status (high-SES) and low socioeconomic status (low-SES) areas participated in the study. Children's physical activity was measured using accelerometry during morning and afternoon recess during a 4-day school week. The percentage of time spent in light, moderate, vigorous, very high and in moderate- to very high-intensity physical activity were calculated using age-dependent cut-points. Sedentary time was defined as 100 counts per minute. Boys were significantly (p active than girls. No difference in sedentary time between socioeconomic backgrounds was observed. The low-SES group spent significantly more time in light (p physical activity compared to the high-SES group. High-SES boys and girls spent significantly more time in moderate (p physical activity than low-SES boys. Differences were observed in recess physical activity levels according to socioeconomic background and sex. These results indicate that recess interventions should target children in low-SES schools.

Background radiation and individual dosimetry in the coastal area of Tamil Nadu (India)

International Nuclear Information System (INIS)

Matsuda, N.; Brahmanandhan, G. M.; Yoshida, M.; Takamura, N.; Suyama, A.; Koguchi, Y.; Juto, N.; Raj, Y. L.; Winsley, G.; Selvasekarapandian, S.

2011-01-01

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 2x7 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 . (authors)

Systematic measurement of fast neutron background fluctuations in an urban area using a mobile detection system

International Nuclear Information System (INIS)

Iyengar, A.; Beach, M.; Newby, R.J.; Fabris, L.; Heilbronn, L.H.; Hayward, J.P.

2015-01-01

Neutron background measurements using a mobile trailer-based system were conducted in Knoxville, Tennessee, USA. The 0.5 m 2 system, consisting of eight EJ-301 liquid scintillation detectors, was used to collect neutron background measurements in order to better understand the systematic variations in background that depend solely on the street-level measurement position in a downtown area. Data was collected along 5 different streets, and the measurements were found to be repeatable. Using 10-min measurements, the fractional uncertainty in each measured data point was <2%. Compared with fast neutron background count rates measured away from downtown Knoxville, a reduction in background count rates ranging from 10% to 50% was observed in the downtown area, sometimes varying substantially over distances of tens of meters. These reductions are attributed to the net shielding of the cosmic ray neutron flux by adjacent buildings. For reference, the building structure as observed at street level is quantified in part here by a measured angle-of-open-sky metric

Systematic measurement of fast neutron background fluctuations in an urban area using a mobile detection system

Energy Technology Data Exchange (ETDEWEB)

Iyengar, A., E-mail: aiyengar@utk.edu [Department of Nuclear and Radiological Engineering, University of Tennessee, Knoxville, TN (United States); Beach, M. [Department of Nuclear and Radiological Engineering, University of Tennessee, Knoxville, TN (United States); Newby, R.J.; Fabris, L. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Heilbronn, L.H. [Department of Nuclear and Radiological Engineering, University of Tennessee, Knoxville, TN (United States); Hayward, J.P. [Department of Nuclear and Radiological Engineering, University of Tennessee, Knoxville, TN (United States); Oak Ridge National Laboratory, Oak Ridge, TN (United States)

2015-02-11

Neutron background measurements using a mobile trailer-based system were conducted in Knoxville, Tennessee, USA. The 0.5 m{sup 2} system, consisting of eight EJ-301 liquid scintillation detectors, was used to collect neutron background measurements in order to better understand the systematic variations in background that depend solely on the street-level measurement position in a downtown area. Data was collected along 5 different streets, and the measurements were found to be repeatable. Using 10-min measurements, the fractional uncertainty in each measured data point was <2%. Compared with fast neutron background count rates measured away from downtown Knoxville, a reduction in background count rates ranging from 10% to 50% was observed in the downtown area, sometimes varying substantially over distances of tens of meters. These reductions are attributed to the net shielding of the cosmic ray neutron flux by adjacent buildings. For reference, the building structure as observed at street level is quantified in part here by a measured angle-of-open-sky metric.

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.

Estimation of individual doses from external exposures and dose-group classification of cohort members in high background radiation area in Yangjiang, China

International Nuclear Information System (INIS)

Yuan Yongling; Shen Hong; Sun Quanfu; Wei Luxin

1999-01-01

Objective: In order to estimate annual effective doses from external exposures in the high background radiation area (HBRA) and in the control area (CA) , the authors measured absorbed dose rates in air from terrestrial gamma radiation with different dosimeters. A dose group classification was an important step for analyzing the dose effects relationship among the cohort members in the investigated areas. The authors used the hamlet specific average annual effective doses of all the 526 hamlets in the investigated areas. A classification of four dose groups was made for the cohort members (high, moderate, low and control) . Methods: For the purpose of studying the dose effect relationships among the cohort members in HBRA and CA, it would be ideal that each subject has his own record of individual accumulated doses received before the evaluation. However, rt is difficult to realize it in practice (each of 106517 persons should wear TLD for a long time) . Thus the authors planned two sets of measurements. Firstly, to measure the environmental dose rates (outdoor, indoor, over the bed) in every hamlet of the investigated area (526 hamlets) , considering the occupancy factors for males and females of different age groups to convert to the annual effective dose from the data of dose rates. Secondly, to measure the individual cumulative dose with TLD for part of the subjects in the investigated areas. Results: Based on the two sets of measurements, the estimates of average annual effective doses in HBRA were 211.86 and 206.75 x 10 -5 Sv/a, respectively, 68.60 and 67.11 x 10 -5 Sv/a, respectively(gamma radiation only) . The intercomparison between these two sets of measurement showed that they were in good correlation. Thus the authors are able to yield the equations of linear regression: Y = 0.9937 + 6.0444, r = 0.9949. Conclusions: The authors took the value obtained from direct measurement as 'standard' , and 15 % for uncertainty of measurement. Since the estimates of

DMBLC: An Indirect Urban Impervious Surface Area Extraction Approach by Detecting and Masking Background Land Cover on Google Earth Image

Directory of Open Access Journals (Sweden)

Min Huang

2018-05-01

Full Text Available Implying the prosperity and development of the city, impervious surface area (ISA is playing an increasingly important role in ecological processes, microclimate, material and energy flows, and urban flood. The free sub-meter resolution Google Earth image, which is integrated by several high spatial resolution data, appears to have potential for high-resolution ISA extraction, where present study is rare and performances remain to be improved. Due to the high spatial and spectral variation of the urban environment as well as confusion between ISA and soil, the accurate delineating of ISA with traditional (direct methods can be costly and time-consuming, which is in a word resource-intensive. However, this paper presents a novel indirect ISA extraction conceptual model and a new detecting and masking background land cover (DMBLC approach that: uses a freely available, high-resolution dataset; requires a reduced set of training samples; and consists of relatively simple, common, and feasible image processing steps. The key characteristic of DMBLC is to detect the background of ISA (vegetation, soil, and water accurately and obtain the ISA by masking the background. The approach relies on background detection to avoid the predicaments of direct ISA extraction. Water can be directly gained by water body vector data, in DMBLC; mixture tuned matched filtering (MTMF is exploited to detect vegetation and soil, image segmentation is used to mitigate the spectral variation problem within the same land cover, and segment rectangularity reduces the confusion between ISA and soil. From experiments in a core area of Fuzhou, China, the DMBLC approach reached high performance and outperformed the powerful traditional support vector machines (SVM method (overall accuracy of 94.45% and Kappa coefficient of 0.8885, compared to 86.44% and 0.7329, respectively. From the comparison of different levels of complexity within the inner processing steps, it is confirmed

MDT Performance in a High Rate Background Environment

CERN Document Server

Aleksa, Martin; Hessey, N P; Riegler, W

1998-01-01

A Cs137 gamma source with different lead filters in the SPS beam-line X5 has been used to simulate the ATLAS background radiation. This note shows the impact of high background rates on the MDT efficiency and resolution for three kinds of pulse shaping and compares the results with GARFIELD simulations. Furthermore it explains how the performance can be improved by time slewing corrections and double track separation.

Measurement of natural background neutron

CERN Document Server

Li Jain, Ping; Tang Jin Hua; Tang, E S; Xie Yan Fong

1982-01-01

A high sensitive neutron monitor is described. It has an approximate counting rate of 20 cpm for natural background neutrons. The pulse amplitude resolution, sensitivity and direction dependence of the monitor were determined. This monitor has been used for natural background measurement in Beijing area. The yearly average dose is given and compared with the results of KEK and CERN.

Systematic measurement of fast neutron background fluctuations in an urban area using a mobile detection system

Science.gov (United States)

Iyengar, A.; Beach, M.; Newby, R. J.; Fabris, L.; Heilbronn, L. H.; Hayward, J. P.

2015-02-01

Neutron background measurements using a mobile trailer-based system were conducted in Knoxville, Tennessee, USA. The 0.5 m2 system, consisting of eight EJ-301 liquid scintillation detectors, was used to collect neutron background measurements in order to better understand the systematic variations in background that depend solely on the street-level measurement position in a downtown area. Data was collected along 5 different streets, and the measurements were found to be repeatable. Using 10-min measurements, the fractional uncertainty in each measured data point was rates measured away from downtown Knoxville, a reduction in background count rates ranging from 10% to 50% was observed in the downtown area, sometimes varying substantially over distances of tens of meters. These reductions are attributed to the net shielding of the cosmic ray neutron flux by adjacent buildings. For reference, the building structure as observed at street level is quantified in part here by a measured angle-of-open-sky metric.

Precise muon drift tube detectors for high background rate conditions

Energy Technology Data Exchange (ETDEWEB)

Engl, Albert

2011-08-04

The muon spectrometer of the ATLAS-experiment at the Large Hadron Collider consists of drift tube chambers, which provide the precise measurement of trajectories of traversing muons. In order to determine the momentum of the muons with high precision, the measurement of the position of the muon in a single tube has to be more accurate than {sigma}{<=}100 {mu}m. The large cross section of proton-proton-collisions and the high luminosity of the accelerator cause relevant background of neutrons and {gamma}s in the muon spectrometer. During the next decade a luminosity upgrade to 5.10{sup 34} cm{sup -2}s{sup -1} is planned, which will increase the background counting rates considerably. In this context this work deals with the further development of the existing drift chamber technology to provide the required accuracy of the position measurement under high background conditions. Two approaches of improving the drift tube chambers are described: - In regions of moderate background rates a faster and more linear drift gas can provide precise position measurement without changing the existing hardware. - At very high background rates drift tube chambers consisting of tubes with a diameter of 15 mm are a valuable candidate to substitute the CSC muon chambers. The single tube resolution of the gas mixture Ar:CO{sub 2}:N{sub 2} in the ratio of 96:3:1 Vol %, which is more linear and faster as the currently used drift gas Ar:CO{sub 2} in the ratio of 97:3 Vol %, was determined at the Cosmic Ray Measurement Facility at Garching and at high {gamma}-background counting rates at the Gamma Irradiation Facility at CERN. The alternative gas mixture shows similar resolution without background. At high background counting rates it shows better resolution as the standard gas. To analyse the data the various parts of the setup have to be aligned precisely to each other. The change to an alternative gas mixture allows the use of the existing hardware. The second approach are drift tubes

Cosmic far-infrared background at high galactic latitudes

International Nuclear Information System (INIS)

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

1977-01-01

We predict far-infrared background fluxes from various cosmic sources. These fluxes lie near the high-frequency side of the blackbody radiation spectrum. These sources could account for a significant fraction of the background radiation at frequencies above 400 GHz which might be misinterpreted as a ''Comptonization'' distortion of the blackbody radiation. Particular attention is paid to the possible contributions from external galaxies, from rich clusters of galaxies, and from galactic dust emission

Cosmic far-infrared background at high galactic latitudes

International Nuclear Information System (INIS)

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

1976-12-01

Far-infrared background fluxes from various cosmic sources are predicted. These fluxes lie near the high-frequency side of the blackbody radiation spectrum. These sources could account for a significant fraction of the background radiation at frequencies above 400 GHz, which might be misinterpreted as a comptonization distortion of the blackbody radiation. Particular attention is paid to the possible contributions from external galaxies, rich clusters of galaxies and from galactic dust emission

Calculation of the correlation coefficients between the numbers of counts (peak areas and backgrounds) obtained from gamma-ray spectra

International Nuclear Information System (INIS)

Korun, M.; Vodenik, B.; Zorko, B.

2016-01-01

Two simple methods for calculating the correlations between peaks appearing in gamma-ray spectra are described. We show how the areas are correlated when the peaks do not overlap, but the spectral regions used for the calculation of the background below the peaks do. When the peaks overlap, the correlation can be stronger than in the case of the non-overlapping peaks. The methods presented are simplified to the extent of allowing their implementation with manual calculations. They are intended for practitioners as additional tools to be used when the correlations between the areas of the peaks in the gamma-ray spectra are to be calculated. Also, the correlation coefficient between the number of counts in the peak and the number of counts in the continuous background below the peak is derived. - Highlights: • The correlation coefficients between areas of closely spaced peaks are assessed. • For isolated peaks the correlation arises from the common continuous background. • If peaks overlap the correlation coefficient depends on how much they overlap. • If peaks overlap also the background height affects the correlation coefficient. • The correlation coefficient between the peak area and its background is −1.

Dose for background radioactivity in areas with high radioactivity levels in the Pinar del Rio province

International Nuclear Information System (INIS)

Alcaide Orpi, J.; Oliveira Acosta, J.; Valdes Hernadez, G.M.; Leal Ramirez, M.R.; Blanco Jorrin, N.

1998-01-01

The objective the work is to know the areas with high natural radiation doses, for they were used it the data obtained by the studies it has more than enough favorability for radioactive minerals carried out in different regions to the Pinar del Rio province in the 1986 to 1993 years and the doses calculations they were carried out according to the effective methodology

NATURAL RADIOACTIVITY LEVEL AND ELEMENTAL COMPOSITION OF SOIL SAMPLES FROM A HIGH BACKGROUND RADIATION AREA ON EASTERN COAST OF INDIA (ODISHA).

Science.gov (United States)

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

2016-10-01

A comprehensive study was carried out to determine the radioactivity concentration of soil samples from different sites of a high background radiation area in the eastern coast of India, Odisha state. The dose rate measured in situ varied from 0.25 to 1.2 µSv h -1 The gamma spectrometry measurements indicated Th series elements as the main contributors to the enhanced level of radiation and allowed the authors to find the mean level of the activity concentration (±SD) for 226 Ra, 228 Th and 40 K as 130±97, 1110±890 and 360±140 Bq kg -1 , respectively. Human exposure from radionuclides occurring outdoor was estimated based on the effective dose rate, which ranged from 0.14±0.02 to 2.15±0.26 mSv and was higher than the UNSCEAR annual worldwide average value 0.07 mSv. Additionally, X-ray fluorescence analysis provided information about the content of major elements in samples and indicated the significant amount of Ti (7.4±4.9 %) in soils. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Epidemiologic studies in the areas with a high level of natural radioactivity

International Nuclear Information System (INIS)

Laurier, D.; Martin, J.M.; Hubert, Ph.

2000-10-01

Since 1970, numerous studies have been interested in high level of natural radiations areas (H.L.N.R.A.) or high background radiation areas (H.B.R.A.). An international conference stands every four years, and the last one was at Munich (Germany). The aim of this note is to make a review of epidemiologic studies made with the populations living in H.L.N.R.A. and to present a synthesis of achieved results. The cytogenetic studies are equally mentioned but not detailed. (N.C.)

Dose measurement, its distribution and individual external dose assessments of inhabitants on high background radiation area in China

Energy Technology Data Exchange (ETDEWEB)

Koga, Taeko; Morishima, Hiroshige [Kinki Univ., Atomic Energy Research Institute, Osaka (Japan); Tatsumi, Kusuo [Kinki Univ., Life Science Research Institute, Osaka (Japan); Nakai, Sayaka; Sugahara, Tsutomu [Health Research Foundation, Kyoto (Japan); Yuan Yongling [Labor Hygiene Institute of Hunan Prov. (China); Wei Luxin [Laboratory of Industorial Hygiene, Ministry of Health (China)

2001-01-01

As a part of the China-Japan cooperative research on the natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external to natural radiation in the high background radiation area (HBRA) of Yangjiang in Guangdong province and in the control area (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by the personal dosimeters, an indirect method was applied to estimate the exposed dose rates from the environmental radiation dose rates measured by survey meters and the occupancy factors of each hamlet. An individual radiation dose roughly correlates with the environmental radiation dose and the life style of the inhabitant. We have analyzed the environmental radiation doses in the hamlets and the variation of the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and the several hamlets of the different level doses in HBRA and Hampizai hamlet in CA. With these parameters, we made estimations of individual dose rates and compared them with those obtained from the direct measurement using dosimeters carried by selected individuals. The results obtained are as follows: (1) The environmental radiation dose rates are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiation. The indoor radiation dose rates were due to the exposure from the natural radioactive nuclides in the building materials and they were about twice higher than the outdoor radiation dose rates. This difference was not observed in CA. (2) The occupancy factor was affected by the age of individuals and the seasons of a year. Indoor occupancy factors were higher for infants and aged individuals than for other age groups. This lead to higher

Dose measurement, its distribution and individual external dose assessments of inhabitants on high background radiation area in China

International Nuclear Information System (INIS)

Koga, Taeko; Morishima, Hiroshige; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

2001-01-01

As a part of the China-Japan cooperative research on the natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external to natural radiation in the high background radiation area (HBRA) of Yangjiang in Guangdong province and in the control area (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by the personal dosimeters, an indirect method was applied to estimate the exposed dose rates from the environmental radiation dose rates measured by survey meters and the occupancy factors of each hamlet. An individual radiation dose roughly correlates with the environmental radiation dose and the life style of the inhabitant. We have analyzed the environmental radiation doses in the hamlets and the variation of the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and the several hamlets of the different level doses in HBRA and Hampizai hamlet in CA. With these parameters, we made estimations of individual dose rates and compared them with those obtained from the direct measurement using dosimeters carried by selected individuals. The results obtained are as follows: 1) The environmental radiation dose rates are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiation. The indoor radiation dose rates were due to the exposure from the natural radioactive nuclides in the building materials and they were about twice higher than the outdoor radiation dose rates. This difference was not observed in CA. 2) The occupancy factor was affected by the age of individuals and the seasons of a year. Indoor occupancy factors were higher for infants and aged individuals than for other age groups. This lead to higher

Precise muon drift tube detectors for high background rate conditions

CERN Document Server

Engl, Albert; Dünnweber, Wolfgang

The muon spectrometer of the ATLAS-experiment at the Large H adron Collider consists of drift tube chambers, which provide the precise m easurement of trajec- tories of traversing muons. In order to determine the moment um of the muons with high precision, the measurement of the position of the m uon in a single tube has to be more accurate than σ ≤ 100 m. The large cross section of proton-proton-collisions and th e high luminosity of the accelerator cause relevant background of neutrons and γ s in the muon spectrome- ter. During the next decade a luminosity upgrade [1] to 5 10 34 cm − 2 s − 1 is planned, which will increase the background counting rates consider ably. In this context this work deals with the further development of the existing drift chamber tech- nology to provide the required accuracy of the position meas urement under high background conditions. Two approaches of improving the dri ft tube chambers are described: • In regions of moderate background rates a faster and more lin ear ...

Dose measurement, its distribution and individual external dose assessments of inhabitants in the high background radiation areas in China

International Nuclear Information System (INIS)

Morishima, Hiroshige; Koga, Taeko; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

2000-01-01

As a part of the China-Japan cooperative research on natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external exposure to natural radiation in the high background radiation areas (HBRA) of Yangjiang in Guangdong province and in the control areas (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by personal dosimeters, an indirect method was applied in which the exposed individual doses were estimated from the environmental radiation doses measured by survey meters and the occupancy factors of each hamlet. We analyzed the dose in the hamlets and the variation in the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and several hamlets of different dose levels in HBRA and Hampizai hamlet in CA. With these parameters, we estimated individual dose rates and compared them with those obtained from direct measurement using dosimeters carried by selected individuals. The results obtained are as follows. The environmental radiation doses are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiations. The indoor radiation doses were due to exposure from the natural radioactive nuclides in the building materials and were about two times as large as the outdoor radiation doses. The difference between indoor and outdoor doses was not observed in CA. The occupancy factor was influenced by the age of individuals and by the season of the year. The occupancy factor was higher for infants and aged individuals than for other age groups. This lead to higher dose rates of exposure to those age groups. A good correlation was observed between the dose assessed indirectly and that measured directly and the

Dose measurement, its distribution and individual external dose assessments of inhabitants in the high background radiation areas in China

Energy Technology Data Exchange (ETDEWEB)

Morishima, Hiroshige; Koga, Taeko [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

2000-10-01

As a part of the China-Japan cooperative research on natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external exposure to natural radiation in the high background radiation areas (HBRA) of Yangjiang in Guangdong province and in the control areas (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by personal dosimeters, an indirect method was applied in which the exposed individual doses were estimated from the environmental radiation doses measured by survey meters and the occupancy factors of each hamlet. We analyzed the dose in the hamlets and the variation in the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and several hamlets of different dose levels in HBRA and Hampizai hamlet in CA. With these parameters, we estimated individual dose rates and compared them with those obtained from direct measurement using dosimeters carried by selected individuals. The results obtained are as follows. The environmental radiation doses are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiations. The indoor radiation doses were due to exposure from the natural radioactive nuclides in the building materials and were about two times as large as the outdoor radiation doses. The difference between indoor and outdoor doses was not observed in CA. The occupancy factor was influenced by the age of individuals and by the season of the year. The occupancy factor was higher for infants and aged individuals than for other age groups. This lead to higher dose rates of exposure to those age groups. A good correlation was observed between the dose assessed indirectly and that measured directly and the

The noise background and its suppression in high energy physics experiment

International Nuclear Information System (INIS)

Meng Xiangcheng

1996-01-01

In the modern high energy physics experiments, system is very complicated and from a lot of sources may originate noise and background. How to reduce and restrain noise and backgrounds? It should use different suppression mode for different kinds of noise and backgrounds

Signal-to-noise ratios of multiplexing spectrometers in high backgrounds

Science.gov (United States)

Knacke, R. F.

1978-01-01

Signal-to-noise ratios and the amount of multiplexing gain achieved with a Michelson spectrometer during detector and background noise are studied. Noise caused by the warm background is found in 10 and 20-micron atmospheric windows in high resolution Fourier spectroscopy. An equation is derived for the signal-to-noise ratio based on the number of channels, total time to obtain the complete spectrum, the signal power in one spectral element, and the detector noise equivalent power in the presence of negligible background. Similar expressions are derived for backgrounds yielding a noise equivalent power to a spectral element, and backgrounds having flat spectra in the frequency range under investigation.

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)

Hubbard, L.; Rantavaara, A.; Andersson, K.; Roed, J.

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)

Localities With Elevated Radiation Background in the High Karst Zone of Montenegro

International Nuclear Information System (INIS)

Vukotic, P.; Svrkota, R.; Andjelic, T.; Zekic, R.; Antovic, N.

2011-01-01

Research aimed to find localities in Montenegro with an elevated terrestrial gamma background was conducted during the period 2008-2009. For this purpose, 138 localities which have geological formations known to contain minerals with potentially high concentrations of U, Th and K, were selected throughout the country for a dosimetric survey. There are four distinctive geotectonic units in Montenegro: the Adriatic-Ionian Zone (JZ), the Budva-Cukali Zone (BZ), the High Karst Zone (VK), and the Durmitor Tectonic Unit (DTJ). The central and southern parts of Montenegro belong to the VK zone, whose geological structure is predominated by Mesozoic carbonate sediments, with occurrences of red and white bauxite formations, Triassic volcanic rocks, Paleogene flysch sediments and Quaternary sediments. In total, 38 localities belonging to the VK zone were selected for field investigations of terrestrial radiation. Knowing from earlier investigations that in Montenegro the average absorbed dose-rate in the air, 1 m above the ground, is 55 nGy/h, it was arbitrarily adopted that only localities with absorbed doses at least 50 % above this average value would be considered as having a relatively elevated radiation background. Field measurements have shown that 12 of the surveyed localities in the VK zone have such elevated dose values, five of them being with the highest dose rates in Montenegro. Among these five sites, the highest dose rate (192 nGy/h) was found at a locality which lies on andesite volcanic rock, while the other four localities (131 - 149 nGy/h) lie on bauxite deposits. Compared to the other areas in the world known to have a high natural radiation background, all of these localities in Montenegro have a moderately elevated radiation level. From the 12 localities with a relatively elevated radiation background, soil samples have been collected and analyzed by gamma spectrometry to determine activity concentrations of 40K, 232Th, 235U, 238U, 226Ra and 137Cs

Italian: Area Background Information.

Science.gov (United States)

Defense Language Inst., Washington, DC.

This booklet has been assembled in order to provide students of Italian with a compact source of cultural information on their target area. Chapters include discussion of: (1) introduction to Italian; (2) origins of the Italian population; (3) geography; (4) history including the Roman Era, the Middle Ages, the Renaissance, the "Risorgimento," and…

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

International Nuclear Information System (INIS)

Masoudzadeh, Nasrin; Zakeri, Fardideh; Lotfabad, Tayebe bagheri; Sharafi, Hakimeh; Masoomi, Fatemeh; Zahiri, Hoseein Shahbani; Ahmadian, Gholamreza; Noghabi, Kambiz Akbari

2011-01-01

Highlights: ► Isolation and characterization of a novel cadmium-biosorbent (Brevundimonas sp. ZF12) from high background radiation areas. ► Brevundimonas sp. ZF12 caused 50% removal of cadmium at the concentration level of 250 ppm. ► Solution pH values used for the reusability study have powerful desorptive features to recover Cd ions sorbed onto the biomass. ► This is the first study carried out so far for the cadmium removal from aqueous solutions by a novel biosorbent Brevundimonas sp. ZF12. ► 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 ( 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.

Position sensitive detection of neutrons in high radiation background field.

Science.gov (United States)

Vavrik, D; Jakubek, J; Pospisil, S; Vacik, J

2014-01-01

We present the development of a high-resolution position sensitive device for detection of slow neutrons in the environment of extremely high γ and e(-) radiation background. We make use of a planar silicon pixelated (pixel size: 55 × 55 μm(2)) spectroscopic Timepix detector adapted for neutron detection utilizing very thin (10)B converter placed onto detector surface. We demonstrate that electromagnetic radiation background can be discriminated from the neutron signal utilizing the fact that each particle type produces characteristic ionization tracks in the pixelated detector. Particular tracks can be distinguished by their 2D shape (in the detector plane) and spectroscopic response using single event analysis. A Cd sheet served as thermal neutron stopper as well as intensive source of gamma rays and energetic electrons. Highly efficient discrimination was successful even at very low neutron to electromagnetic background ratio about 10(-4).

Porous silicon structures with high surface area/specific pore size

Science.gov (United States)

Northrup, M.A.; Yu, C.M.; Raley, N.F.

1999-03-16

Fabrication and use of porous silicon structures to increase surface area of heated reaction chambers, electrophoresis devices, and thermopneumatic sensor-actuators, chemical preconcentrates, and filtering or control flow devices. In particular, such high surface area or specific pore size porous silicon structures will be useful in significantly augmenting the adsorption, vaporization, desorption, condensation and flow of liquids and gases in applications that use such processes on a miniature scale. Examples that will benefit from a high surface area, porous silicon structure include sample preconcentrators that are designed to adsorb and subsequently desorb specific chemical species from a sample background; chemical reaction chambers with enhanced surface reaction rates; and sensor-actuator chamber devices with increased pressure for thermopneumatic actuation of integrated membranes. Examples that benefit from specific pore sized porous silicon are chemical/biological filters and thermally-activated flow devices with active or adjacent surfaces such as electrodes or heaters. 9 figs.

Preliminary analysis of data (1987-1990) from investigation of cancer mortality in high background radiation area of Yangjiang, China

International Nuclear Information System (INIS)

Tao Zufan; Sun Quanfu; Zhang Shouzhi

1997-01-01

Objective: The cancer mortality study conducted in the high background radiation area (HBRA) of Yangjiang, China, was started in 1972. The major objective of the study was to estimate cancer risk associated with the low level radiation exposure in HBRA. Since 1991, the cancer mortality data were collected from a fixed cohort instead of a dynamic one as in the previous stage. The purpose of the study in the current stage was to accumulate further person-years (Pyr) of observation for improving the statistical power of test in the estimates of cancer risk associated with the natural radiation exposure and to see the reproducibility of the previous results. Methods: The collection of cancer mortality data consisted of two phases, the survey of demography and the ascertainment of death causes. The estimates of relative risk (RR) were calculated by AMFIT in Epicure (Hirosoft International Corp., 1988-1992). Results: During the period of 1987-1990 there were 231 cancer deaths among 421640 Pyr at risk in the cohort of 106517 subjects, which were classified into four groups based on the hamlet-specific average annual gamma ray absorbed doses: three groups (high , medial and low doses) from HBRA and control group from CA. The RRs adjusted for sex and age for each dose group in HBRA compared with the control group for overall cancers and for all cancers except leukemia were less than 1 except for the low dose group, and there seemed to be a trend of RR decrease with the increase of exposure dose from natural radiation, though there was no statistically significant difference. As for the site-specific cancer studied, the cancers of lungs, liver, stomach, nasopharynx and leukemia, the RRs were also less than 1 except for nasopharynx cancer and for leukemia in the high dose group. The analysis of combined data ( 1979-1990) showed similar results. Conclusion: Although the sample size was not large enough to make definite conclusion statistically, the observation of current

Ingestion dose from 238U, 232Th, 226Ra, 40K and 137CS in cereals, pulses and drinking water to adult population in a high background radiation area, Odisha (India)

International Nuclear Information System (INIS)

Lenka, P.; Sahoo, S. K.; Mohapatra, S.; Patra, A. C.; Dubey, J. S.; Vidyasagar, D.; Tripathi, R. M.; Puranik, V. D.

2013-01-01

A natural high background radiation area is located in Chhatrapur, Odisha in the eastern part of India. The inhabitants of this area are exposed to external radiation levels higher than the global average background values, due to the presence of uranium, thorium and its decay products in the monazite sands bearing placer deposits in its beaches. The concentrations of 232 Th, 238 U, 226 Ra, 40 K and 137 Cs were determined in cereals (rice and wheat), pulses and drinking water consumed by the population residing around this region and the corresponding annual ingestion dose was calculated. The annual ingestion doses from cereals, pulses and drinking water varied in the range of 109.4-936.8, 10.2-307.5 and 0.5-2.8 μSv y -1 , respectively. The estimated total annual average effective dose due to the ingestion of these radionuclides in cereals, pulses and drinking water was 530 μSv y -1 . The ingestion dose from cereals was the highest mainly due to a high consumption rate. The highest contribution of dose was found to be from 226 Ra for cereals and drinking water and 40 K was the major dose contributor from the intake of pulses. The contribution of man-made radionuclide 137 Cs to the total dose was found to be minimum. 226 Ra was found to be the largest contributor to ingestion dose from all sources. (authors)

Precision tracking at high background rates with the ATLAS muon spectrometer

CERN Document Server

Hertenberger, Ralf; The ATLAS collaboration

2012-01-01

Since start of data taking the ATLAS muon spectrometer performs according to specification. End of this decade after the luminosity upgrade of LHC by a factor of ten the proportionally increasing background rates require the replacement of the detectors in the most forward part of the muon spectrometer to ensure high quality muon triggering and tracking at background hit rates of up to 15,kHz/cm$^2$. Square meter sized micromegas detectors together with improved thin gap trigger detectors are suggested as replacement. Micromegas detectors are intrinsically high rate capable. A single hit spatial resolution below 40,$mu$m has been shown for 250,$mu$m anode strip pitch and perpendicular incidence of high energy muons or pions. The ongoing development of large micromegas structures and their investigation under non-perpendicular incidence or in high background environments requires precise and reliable monitoring of muon tracks. A muon telescope consisting of six small micromegas works reliably and is presently ...

The estimation of doses to the inhabitants arising from natural radiation source in the high background radiation area of Yangjiang, China

International Nuclear Information System (INIS)

Yuan Yongling; Shen Hong; Morishima, H.; Wei Lvxin; Jian Yuannu

2004-01-01

Objective: The purposes is to estimate the average annual effective dose of the inhabitants and absorbed dose in some human tissues and organs arising from natural radiation sources in the High Background Radiation Area (HBRA) of Yangjiang and in the neighboring Control Area (CA). In order to provide more effective evidence for analyzing the dose-effect relationships among the cohort members in the investigated areas, authors divided the local inhabitant into different dose-groups. Methods: The authors measured the environmental gamma external radiation levels and individual accumulated doses of 5293 people in the investigated areas. The concentrations for 222 Rn, 220 Rn and their decay products in air were also surveyed. The authors estimated the internal doses of natural radionuclides based on the results obtained from measurements in food, in drinking water, in human teeth, in several human tissues, in human placenta, and in activity concentration of exhaled 222 Rn and 220 Rn of the residents living in the investigated areas. Results: The estimation of average annual effective doses in HBRA and CA based on the data of environmental measurements of radiation level respectively are 2.12 ± 0.29 mSv a -1 and 0.69 ± 0.09 mSv a -1 . The sources of higher background radiation in HBRA are mainly contributed from terrestrial gamma radiation. The estimation of average annual effective doses to the residents arising from inhalation of 222 Rn, 220 Rn and their decay products was 3.28 mSv a -1 in HBRA, while that in CA was 1.03 mSv a -1 . The values of the absorbed dose of the residents in their trachea-bronchial tree and lung in HBRA arising from inhalation of 222 Rn, 220 Rn and their decay products are 5.40 mGy a -1 and 1.08 mGy a -1 respectively, which are about four times of the values of the absorbed dose in CA. The estimation of average annual effective doses to the inhabitants caused by 226 Ra and 228 Ra in HBRA and CA were 281.88 μSv a -1 and 84.54 μSv a -1

High-Energy Neutron Backgrounds for Underground Dark Matter Experiments

Energy Technology Data Exchange (ETDEWEB)

Chen, Yu [Syracuse Univ., NY (United States)

2016-01-01

Direct dark matter detection experiments usually have excellent capability to distinguish nuclear recoils, expected interactions with Weakly Interacting Massive Particle (WIMP) dark matter, and electronic recoils, so that they can efficiently reject background events such as gamma-rays and charged particles. However, both WIMPs and neutrons can induce nuclear recoils. Neutrons are then the most crucial background for direct dark matter detection. It is important to understand and account for all sources of neutron backgrounds when claiming a discovery of dark matter detection or reporting limits on the WIMP-nucleon cross section. One type of neutron background that is not well understood is the cosmogenic neutrons from muons interacting with the underground cavern rock and materials surrounding a dark matter detector. The Neutron Multiplicity Meter (NMM) is a water Cherenkov detector capable of measuring the cosmogenic neutron flux at the Soudan Underground Laboratory, which has an overburden of 2090 meters water equivalent. The NMM consists of two 2.2-tonne gadolinium-doped water tanks situated atop a 20-tonne lead target. It detects a high-energy (>~ 50 MeV) neutron via moderation and capture of the multiple secondary neutrons released when the former interacts in the lead target. The multiplicity of secondary neutrons for the high-energy neutron provides a benchmark for comparison to the current Monte Carlo predictions. Combining with the Monte Carlo simulation, the muon-induced high-energy neutron flux above 50 MeV is measured to be (1.3 ± 0.2) ~ 10-9 cm-2s-1, in reasonable agreement with the model prediction. The measured multiplicity spectrum agrees well with that of Monte Carlo simulation for multiplicity below 10, but shows an excess of approximately a factor of three over Monte Carlo prediction for multiplicities ~ 10 - 20. In an effort to reduce neutron backgrounds for the dark matter experiment SuperCDMS SNO- LAB, an active neutron veto was developed

Myocardial Infarction Area Quantification using High-Resolution SPECT Images in Rats

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Luciano Fonseca Lemos de [Divisão de Cardiologia, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Mejia, Jorge [Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, SP (Brazil); Carvalho, Eduardo Elias Vieira de; Lataro, Renata Maria; Frassetto, Sarita Nasbine [Divisão de Cardiologia, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Fazan, Rubens Jr.; Salgado, Hélio Cesar [Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Galvis-Alonso, Orfa Yineth [Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, SP (Brazil); Simões, Marcus Vinícius, E-mail: msimoes@fmrp.usp.br [Divisão de Cardiologia, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

2013-07-15

Imaging techniques enable in vivo sequential assessment of the morphology and function of animal organs in experimental models. We developed a device for high-resolution single photon emission computed tomography (SPECT) imaging based on an adapted pinhole collimator. To determine the accuracy of this system for quantification of myocardial infarct area in rats. Thirteen male Wistar rats (250 g) underwent experimental myocardial infarction by occlusion of the left coronary artery. After 4 weeks, SPECT images were acquired 1.5 hours after intravenous injection of 555 MBq of 99mTc-Sestamibi. The tomographic reconstruction was performed by using specially developed software based on the Maximum Likelihood algorithm. The analysis of the data included the correlation between the area of perfusion defects detected by scintigraphy and extent of myocardial fibrosis assessed by histology. The images showed a high target organ/background ratio with adequate visualization of the left ventricular walls and cavity. All animals presenting infarction areas were correctly identified by the perfusion images. There was no difference of the infarct area as measured by SPECT (21.1 ± 21.2%) and by histology (21.7 ± 22.0%; p=0.45). There was a strong correlation between individual values of the area of infarction measured by these two methods. The developed system presented adequate spatial resolution and high accuracy for the detection and quantification of myocardial infarction areas, consisting in a low cost and versatile option for high-resolution SPECT imaging of small rodents.

Top soil radioactivity assessment in a high natural radiation background area: the case of Vinaninkarena, Antsirabe-Madagascar.

Science.gov (United States)

Rabesiranana, Naivo; Rasolonirina, Martin; Terina, Franck; Solonjara, Asivelo F; Andriambololona, Raoelina

2008-11-01

The village of Vinaninkarena, Antsirabe, Madagascar (47 degrees 02'40''E, 19 degrees 57'17''S) is located in a high natural radioactivity area. In order to evaluate the natural radionuclide content in soil, sampling was done on-site by the transect method (85 soil samples) and off-site through transects across and beyond the region (up to a range of 100 km), to determine the natural radioactivity variation within vs. outside the region, and to detect significant differences, taking into account spatial variability.

Background and stimulus-induced patterns of high metabolic activity in the visual cortex (area 17) of the squirrel and macaque monkey

International Nuclear Information System (INIS)

Humphrey, A.L.; Hendrickson, A.E.

1983-01-01

We have used 2-deoxy-D-[ 14 C]glucose (2-DG) autoradiography and cytochrome oxidase histochemistry to examine background and stimulus-induced patterns of metabolic activity in monkey striate cortex. In squirrel monkeys (Saimiri sciureus) that binocularly or monocularly viewed diffuse white light or binocularly viewed bars of many orientations and spatial frequencies, 2-DG consumption was not uniform across the cortex but consisted of regularly spaced radial zones of high uptake. The zones extended through all laminae except IVc beta and, when viewed tangentially, formed separate patches 500 microns apart. The cytochrome oxidase stain in these animals also revealed patches of high metabolism which coincided with the 2-DG patches. Squirrel monkeys binocularly viewing vertical stripes showed parallel bands of increased 2-DG uptake in the cortex, while the cytochrome label in these animals remained patchy. When monkeys were kept in the dark during 2-DG exposure, 2-DG-labeled patches were not seen but cytochrome oxidase-positive patches remained. In macaque (Macaca nemestrina) monkeys, binocular stimulation with many orientations and spatial frequencies produced radial zones of high 2-DG uptake in layers I to IVa and VI. When viewed tangentially, these zones formed a dots-in-rows pattern with a spacing of 350 X 500 microns; cytochrome oxidase staining produced an identical pattern. Macaca differed from Saimiri in that monocular stimulation labeled alternate rows. These results indicate that there are radial zones of high background metabolism across squirrel and macaque monkey striate cortex. In Saimiri these zones do not appear to be related to an eye dominance system, while in Macaca they do. The presence of these zones of high metabolism may complicate the interpretation of 2-DG autoradiographs that result from specific visual stimuli

The grey areas in soil pollution risk mapping : The distinction between cases of soil pollution and increased background levels

NARCIS (Netherlands)

Gaast, N. van der; Leenaers, H.; Zegwaard, J.

1998-01-01

The progress of soil clean up in the Netherlands is severely hindered by the lack of common agreement on how to describe the grey areas of increased background levels of pollutants. In this study practical methods are proposed in which background levels are described as distribution functions within

Natural background radiation in Jordan

International Nuclear Information System (INIS)

Daoud, M.N.S.

1997-01-01

An Airborne Gamma Ray survey has been accomplished for Jordan since 1979. A complete report has been submitted to the Natural Resources Authority along with field and processed data ''digital and analogue''. Natural radioelements concentration is not provided with this report. From the corrected count rate data for each natural radioelement, Concentrations and exposure rates at the ground level were calculated. Contoured maps, showing the exposure rates and the dose rates were created. Both maps reflect the surface geology of Jordan, where the Phosphate areas are very well delineated by high-level contours. In southeastern Jordan the Ordovician sandstone, which contain high percentage of Th (around 2000 ppm in some places) and a moderate percentage of U (about 300 ppm), also show high gamma radiation exposures compared with the surrounding areas. Comparing the values of the exposure rates given in (μR/h) to those obtained from other countries such as United States, Canada, Germany, etc. Jordan shows higher background radiation which reach two folds and even more than those in these countries. More detailed studies should be performed in order to evaluate the radiological risk limits on people who are living in areas of high radiation such that the area of the phosphatic belt which covers a vast area of Jordan high Plateau. (author)

Mechanism of high-temperature background of internal friction in metals

International Nuclear Information System (INIS)

Shapoval, B.I.; Arzhavitin, V.M.

1988-01-01

Data of theoretical and experimental studies on energy dissipation in vibrating metal at small amplitudes and elevated temperatures (high temperature background of internal friction) are generalized and systematized. Evolution of knowledge of the background as a phenomenon influenced mainly by crystal structure defects - their form, quantity, mobility and interaction is followed. Considered is a wide range of investigated metal states and measurement conditions, and interrelations with other characteristics, for instance, strength ones. On the basis of the data obtained by authors and other investigations a concept of an additional third stage of the background increase with the temperature - the stage of deviation from exponential dependence at premelting point, is introduced. 107 refs.; 32 figs.; 3 tabs

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

High signal in bone marrow at diffusion-weighted imaging with body background suppression (DWIBS) in healthy children

Energy Technology Data Exchange (ETDEWEB)

Ording Mueller, Lil-Sofie; Avenarius, Derk [University Hospital North Norway, Department of Radiology, Tromsoe (Norway); Olsen, Oeystein E. [Great Ormond Street Hospital for Children, Department of Radiology, London (United Kingdom)

2011-02-15

In our experience, diffusion-weighted imaging with body background suppression (DWIBS) is hard to interpret in children who commonly have foci of restricted diffusion in their skeletons unrelated to pathology, sometimes in an asymmetrical pattern. This raises serious concern about the accuracy of DWIBS in cancer staging in children. To describe the signal distribution at DWIBS in the normal developing lumbar spine and pelvic skeleton. Forty-two healthy children underwent an MR DWIBS sequence of the abdomen and pelvis. An axial short-tau inversion-recovery (STIR) echo-planar imaging (EPI) pulse sequence was used. Two radiologists did a primary review of the images and based on these preliminary observations, separate scoring systems for the lumbar spine, pelvis and proximal femoral epiphyses/femoral heads were devised. Visual evaluation of the images was then performed by the two radiologists in consensus. The scoring was repeated separately 2 months later by a third radiologist. Restricted diffusion was defined as areas of high signal compared to the background. Coronal maximum intensity projection (MIP) reformats were used to assess the vertebral bodies. For the pelvis, the extension of high signal for each bone was given a score of 0 to 4. Cohen's Kappa interobserver agreement coefficients of signal distribution and asymmetry were calculated. All children had areas of high signal, both within the lumbar vertebral bodies and within the pelvic skeleton. Three patterns of signal distribution were seen in the lumbar spine, but no specific pattern was seen in the pelvis. There was a tendency toward a reduction of relative area of high signal within each bone with age, but also a widespread interindividual variation. Restricted diffusion is a normal finding in the pelvic skeleton and lumbar spine in children with an asymmetrical distribution seen in 48% of normal children in this study. DWIBS should be used with caution for cancer staging in children as this could

High signal in bone marrow at diffusion-weighted imaging with body background suppression (DWIBS) in healthy children

International Nuclear Information System (INIS)

Ording Mueller, Lil-Sofie; Avenarius, Derk; Olsen, Oeystein E.

2011-01-01

In our experience, diffusion-weighted imaging with body background suppression (DWIBS) is hard to interpret in children who commonly have foci of restricted diffusion in their skeletons unrelated to pathology, sometimes in an asymmetrical pattern. This raises serious concern about the accuracy of DWIBS in cancer staging in children. To describe the signal distribution at DWIBS in the normal developing lumbar spine and pelvic skeleton. Forty-two healthy children underwent an MR DWIBS sequence of the abdomen and pelvis. An axial short-tau inversion-recovery (STIR) echo-planar imaging (EPI) pulse sequence was used. Two radiologists did a primary review of the images and based on these preliminary observations, separate scoring systems for the lumbar spine, pelvis and proximal femoral epiphyses/femoral heads were devised. Visual evaluation of the images was then performed by the two radiologists in consensus. The scoring was repeated separately 2 months later by a third radiologist. Restricted diffusion was defined as areas of high signal compared to the background. Coronal maximum intensity projection (MIP) reformats were used to assess the vertebral bodies. For the pelvis, the extension of high signal for each bone was given a score of 0 to 4. Cohen's Kappa interobserver agreement coefficients of signal distribution and asymmetry were calculated. All children had areas of high signal, both within the lumbar vertebral bodies and within the pelvic skeleton. Three patterns of signal distribution were seen in the lumbar spine, but no specific pattern was seen in the pelvis. There was a tendency toward a reduction of relative area of high signal within each bone with age, but also a widespread interindividual variation. Restricted diffusion is a normal finding in the pelvic skeleton and lumbar spine in children with an asymmetrical distribution seen in 48% of normal children in this study. DWIBS should be used with caution for cancer staging in children as this could lead

Germline mutation rates in families residing in high level natural radiation areas of Kerala coast in southwest India

International Nuclear Information System (INIS)

Das, Birajalaxmi; Ghosh, Anu; Ahmad, Shazia; Saini, DivyaIakshmi; Chauhan, P.S.; Seshadri, M.

2010-01-01

For this study, 200 nuclear families have been analyzed using over 40 mini- and microsatellite markers. Cord blood samples for the child and peripheral blood samples for the parent(s) were collected in EDTA vacuutainers from the hospital units located in High Level Natural Radiation Areas (HLNRA) and Normal Level Natural Radiation Areas (NLNRA). Both the parents of the newborn were exposed to the background dose. The families were grouped into four distinct dose groups - NLNRA group 5.00 mGy/year. An overall mutation rate of 2.08 X 10 -3 per cell per generation was observed for NLNRA and 2.12 X 10 -3 per cell per generation for HLNRA families. No radiation induced dose response was observed for the stratified groups. Thus, this study shows that mutation rates at mini- and microsatellites in the off springs of the parents living in the high background radiation areas of Kerala does not vary with radiation exposure. This is the first report to understand germline mutation rates at hypervariable loci in families residing in high level natural radiation areas of the world

JEM-X background models

DEFF Research Database (Denmark)

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

2003-01-01

Background and determination of its components for the JEM-X X-ray telescope on INTEGRAL are discussed. A part of the first background observations by JEM-X are analysed and results are compared to predictions. The observations are based on extensive imaging of background near the Crab Nebula...... on 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...... 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...

Assessment of external and internal doses due to farming in high background radiation areas in old tin mining localities in Jos-plateau, Nigeria

International Nuclear Information System (INIS)

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

2009-01-01

Farming on soils situated in high background radiation areas can result to enhanced radiation exposure scenarios and pathways to humans. To assess the likely levels of exposures, farm soil samples were collected from different farmlands in three old tin mining localities (Bitsichi, Bukuru and Ropp) in Jos Plateau Nigeria, known for high radiations. The soil samples were analyzed for the activity concentrations of 226 Ra, 232 Th and 40 K, using gamma-ray spectroscopy. The outdoor annual effective dose rates were calculated using the activity concentrations of the radionuclides and were found to vary from 0.07 mSv to 2.02 mSv across the three localities. Considering dust generation from soil tillage and inadvertent ingestion of soil particles, the likely internal radiation hazards were estimated using conservative dust and soil loading factors. The total average annual effective dose rates due to 226 Ra and 232 Th that could result from dust inhalation and ingestion of soil particles were 16.9 μSv, 8.1 μSv and 8.8 μSv, respectively for Bitsichi, Bukuru and Ropp. Though these values are about 5% the outdoor exposures to the farmers in those farms and greater than 1 μSv y-1, from the point of view of radiation protection and risk, they are significant. It suffices to say, therefore, that the results of this study will create the possibility of the importance to evaluate the health risk among the farming population and workplace environments which often is not covered by regulations concerning health protection. (author)

Natural background radiation in Jordan

Energy Technology Data Exchange (ETDEWEB)

Daoud, M N.S. [National Resources Authority, Ministry of Energy and Mineral Resources, Amman (Jordan)

1997-11-01

An Airborne Gamma Ray survey has been accomplished for Jordan since 1979. A complete report has been submitted to the Natural Resources Authority along with field and processed data ``digital and analogue``. Natural radioelements concentration is not provided with this report. From the corrected count rate data for each natural radioelement, Concentrations and exposure rates at the ground level were calculated. Contoured maps, showing the exposure rates and the dose rates were created. Both maps reflect the surface geology of Jordan, where the Phosphate areas are very well delineated by high-level contours. In southeastern Jordan the Ordovician sandstone, which contain high percentage of Th (around 2000 ppm in some places) and a moderate percentage of U (about 300 ppm), also show high gamma radiation exposures compared with the surrounding areas. Comparing the values of the exposure rates given in ({mu}R/h) to those obtained from other countries such as United States, Canada, Germany, etc. Jordan shows higher background radiation which reach two folds and even more than those in these countries. More detailed studies should be performed in order to evaluate the radiological risk limits on people who are living in areas of high radiation such that the area of the phosphatic belt which covers a vast area of Jordan high Plateau. (author). 8 refs, 10 figs, 7 tabs.

Radiochemical and radioecological studies on Brazilian areas of high natural background. Progress report, October 30, 1974--October 30, 1975

International Nuclear Information System (INIS)

Costa-Ribeiro, C.; Penna-Franca, E.; Rocha-Nogueira, A.; Christian-Pfeiffer, W.

1975-11-01

The absorption of 212 Pb and/or 212 Bi by ertythrocytes was investigated in an attempt to explain the in vivo genesis of somatic chromosomal aberrations of the type detected in peripheral blood lymphocytes of workers professionally exposed to 220 Rn and its decay products, as well as in dwellers of Brazilian areas of high natural radioactivity

Large Aperture "Photon Bucket" Optical Receiver Performance in High Background Environments

Science.gov (United States)

Vilnrotter, Victor A.; Hoppe, D.

2011-01-01

The potential development of large aperture groundbased "photon bucket" optical receivers for deep space communications, with acceptable performance even when pointing close to the sun, is receiving considerable attention. Sunlight scattered by the atmosphere becomes significant at micron wavelengths when pointing to a few degrees from the sun, even with the narrowest bandwidth optical filters. In addition, high quality optical apertures in the 10-30 meter range are costly and difficult to build with accurate surfaces to ensure narrow fields-of-view (FOV). One approach currently under consideration is to polish the aluminum reflector panels of large 34-meter microwave antennas to high reflectance, and accept the relatively large FOV generated by state-of-the-art polished aluminum panels with rms surface accuracies on the order of a few microns, corresponding to several-hundred micro-radian FOV, hence generating centimeter-diameter focused spots at the Cassegrain focus of 34-meter antennas. Assuming pulse-position modulation (PPM) and Poisson-distributed photon-counting detection, a "polished panel" photon-bucket receiver with large FOV will collect hundreds of background photons per PPM slot, along with comparable signal photons due to its large aperture. It is demonstrated that communications performance in terms of PPM symbol-error probability in high-background high-signal environments depends more strongly on signal than on background photons, implying that large increases in background energy can be compensated by a disproportionally small increase in signal energy. This surprising result suggests that large optical apertures with relatively poor surface quality may nevertheless provide acceptable performance for deep-space optical communications, potentially enabling the construction of cost-effective hybrid RF/optical receivers in the future.

A new high background radiation area in the Geothermal region of Eastern Ghats Mobile Belt (EGMB) of Orissa, India

International Nuclear Information System (INIS)

Baranwal, V.C.; Sharma, S.P.; Sengupta, D.; Sandilya, M.K.; Bhaumik, B.K.; Guin, R.; Saha, S.K.

2006-01-01

A high natural radiation zone is investigated for the first time in a geothermal region of Eastern Ghats Mobile Belt (EGMB) of Orissa state in India. The surrounding area comprises a geothermal region which has surveyed using a portable pulsed Geiger-Muller counter. On the basis of findings of GM counter, an area was marked as a high radiation zone. Soil and rock samples collected from the high radiation zone were analyzed by γ-ray spectrometry (GRS) using NaI(Tl) detector. The radioactivity is found to be contributed mainly by thorium. Concentration of thorium is reported to be very high compared to their normal abundance in crustal rocks. Further, concentrations of 238 U and 40 K are also high compared to normal abundance in crustal rocks but their magnitude is comparatively less than that of thorium. The average concentrations of 238 U (i.e. U(β-γ)), 232 Th and 40 K are found to be 33, 459ppm and 3%, respectively, in soils and 312, 1723ppm and 5%, respectively, in the granitic rocks. Maximum concentrations of 238 U, 232 Th and 40 K are found to be 95, 1194ppm and 4%, respectively, in soils and 1434, 10,590ppm and 8%, respectively, in the granitic rocks. Radioactive element emits various energies in its decay chain. High energies are utilized to estimate the concentration of actual 238 U, 232 Th and 40 K using a NaI(Tl) detector, however, low energies are used for the same in an HPGe detector. Some of the rock samples (eight in number) were also analyzed using HPGe detector for studying the behavior of low energies emitted in the decay series of uranium and thorium. The absorbed gamma dose rate in air and external annual dose rate of the high radiation zone are calculated to be 2431nGy/h and 3.0mSv/y, respectively. It is approximately 10 times greater than the dose rates obtained outside the high radiation zone. The high concentration of uranium and thorium may be one of the possible heat sources together with the normal geothermal gradient for hot springs

An overview of background environmental radiological surveillance around Kudankulam nuclear power project site

International Nuclear Information System (INIS)

Rajan, M.P.; Vijayakumar, B.; George, Thomas; Rajan, P.S.; Rana, B.K.; Kumar, M.; Hegde, A.G.; Chougaonkar, M.P.

2005-01-01

A modern Environmental Survey Laboratory (ESL) equipped with state-of-art nuclear counting, chemical and ecological equipment's has been set up at Kudankulam at the very beginning of construction activities to carry out pre operational and baseline radioactivity measurements. Construction activities for the two VVER type 1000 MWe reactors at the site are progressing ahead of schedule and the first unit is slated to be critical in the year 2007. This paper presents the results of environmental radiological surveillance carried out for the last one year in Kudankulam environs. General radiation background in the area varies in the range of 0.1 - 0.7 μGy/h and elevated levels as high as 20 μGy/h are noticed in beach areas. The major contribution to the background radiation in high background areas comes from 232 Th and its daughter products. The concentrations of 40 K are of normal order and comparable to other NPP sites and normal background areas. The concentrations of fallout nuclides are very low and are at global fallout levels. (author)

State of the art of D ampersand D Instrumentation Technology: Alpha counting in the presence of high background

International Nuclear Information System (INIS)

Dickerman, C.E.

1995-08-01

Discrimination of alpha activity in the presence of a high radiation background has been identified as an area of concern to be studied for D ampersand D applications. Upon evaluating the range of alpha detection needs for D ampersand D operations, we have expanded this study to address the operational concern of greatly expediting alpha counting of rough surfaces and rubble. Note that the term, ''rough surfaces'' includes a wide range of practical cases, including contaminated equipment and work surfaces. We have developed provisional applications requirements for instrumentation of this type; and we also have generated the scope of a program of instrument evaluation and testing, with emphasis on practical implementation. In order to obtain the full operational benefit of alpha discrimination in the presence of strong beta-gamma radiation background, the detection system must be capable of some form of remote or semi-remote operation in order to reduce operator exposure. We have identified a highly promising technique, the long-range alpha detector (LRAD), for alpha discrimination in the presence of high radiation background. This technique operates upon the principle of transporting alphaionized air to an ionization detector. A transport time within a few seconds is adequate. Neither the provisional requirements nor the evaluation and testing scope were expressly tailored to force the selection of a LRAD technology, and they could be used as a basis for studies of other promising technologies. However, a technology that remotely detects alpha-ionized air (e. g., LRAD) is a natural fit to the key requirements of rejection of high background at the survey location and operator protection. Also, LRAD appears to be valuable for D ampersand D applications as a means of greatly expediting surface alpha-activity surveys that otherwise would require performing time-consuming scans over surfaces of interest with alpha detector probes, and even more labor-intensive surface

Multiple chromosome aberrations among newborns from high level natural radiation area and normal level natural radiation area of south west coast of Kerala

International Nuclear Information System (INIS)

Soren, D.C.; Ramachandran, E.N.; Karuppasamy, C.V.; Cheriyan, V.D.; Anil Kumar, V.; Koya, P.K.M.; Seshadri, M.

2010-01-01

Cord blood samples were collected in heparin vials and microculture techniques employed to obtain good metaphase chromosome spreads. In cytogenetic studies on newborns cells with multiple aberrations were recorded in 57 from a total of 27285 newborns (1266972 cells). Of these 17294 newborns (964140 cells) were from High Level Natural Radiation Area (HLNRA) and 9991 newborns (302832 cells) from Normal Level Natural Radiation Area (NLNRA). Cells with multiple aberrations were observed in 38 and 19 newborns from High and Normal Level Natural Radiation Area respectively. On an average one cell with multiple aberrations was observed among 479 newborns. Cells with multiple aberrations were observed in newborns from HLNRA as well as NLNRA in both males and females. Gender difference of newborns, maternal age group and background radiation levels did not seem to have any influence in the occurrence of Multiple chromosome aberrations

Environmental literacy based on educational background

Science.gov (United States)

Agfar, A.; Munandar, A.; Surakusumah, W.

2018-05-01

This research aims to examine attitude, knowledge and cognitive skill. To collect data we used survey method, was conducted in Pahawang, Lampung. Respondents of this research are coastal society of Pahawang, 114 participants determined using purposive sampling, from two areas in the village, Pahawang and Penggetahan. Data were analyzed using both quantitative and descriptive. Environmental literacy of the society which is primary school graduate is moderate category (85.61), consist of 38.90% in low category and 61.10% in moderate category. Environmental literacy of junior high school graduate is moderate (99.36), consist of 12% in low category, 76% in moderate category and 12% in high category. Environmental literacy of senior high school graduate is moderate (108.85), consist of 84.90% moderate category and 15.10% in high category. But, undergraduate society is high category (118.53). Details 0% low category 52.94% moderate category and 47.06% in high category. This finding research has revelaed that the educational background affects the level of environmental literacy. This finding research has revealed that the educational background affects the level of environmental literacy.

Detection of admittivity anomaly on high-contrast heterogeneous backgrounds using frequency difference EIT.

Science.gov (United States)

Jang, J; Seo, J K

2015-06-01

This paper describes a multiple background subtraction method in frequency difference electrical impedance tomography (fdEIT) to detect an admittivity anomaly from a high-contrast background conductivity distribution. The proposed method expands the use of the conventional weighted frequency difference EIT method, which has been used limitedly to detect admittivity anomalies in a roughly homogeneous background. The proposed method can be viewed as multiple weighted difference imaging in fdEIT. Although the spatial resolutions of the output images by fdEIT are very low due to the inherent ill-posedness, numerical simulations and phantom experiments of the proposed method demonstrate its feasibility to detect anomalies. It has potential application in stroke detection in a head model, which is highly heterogeneous due to the skull.

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)

Mortazavi, S. M. J.; Ghiassi-nejad, M.

2003-01-01

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

Assessment of natural background radiation in one of the highest regions of Ecuador

Science.gov (United States)

Pérez, Mario; Chávez, Estefanía; Echeverría, Magdy; Córdova, Rafael; Recalde, Celso

2018-05-01

Natural background radiation was measured in the province of Chimborazo (Ecuador) with the following reference coordinates 1°40'00''S 78°39'00''W, where the furthest point to the center of the planet is located. Natural background radiation measurements were performed at 130 randomly selected sites using a Geiger Müller GCA-07W portable detector; these measurements were run at 6 m away from buildings or walls and 1 m above the ground. The global average natural background radiation established by UNSCEAR is 2.4 mSv y-1. In the study area measurements ranged from 0.57 mSv y-1 to 3.09 mSv y-1 with a mean value of 1.57 mSv y-1, the maximum value was recorded in the north of the study area at 5073 metres above sea level (m.a.s.l.), and the minimum value was recorded in the southwestern area at 297 m.a.s.l. An isodose map was plotted to represent the equivalent dose rate due to natural background radiation. An analysis of variance (ANOVA) between the data of the high and low regions of the study area showed a significant difference (p < α), in addition a linear correlation coefficient of 0.92 was obtained, supporting the hypothesis that in high altitude zones extraterrestrial radiation contributes significantly to natural background radiation.

PCA-based approach for subtracting thermal background emission in high-contrast imaging data

Science.gov (United States)

Hunziker, S.; Quanz, S. P.; Amara, A.; Meyer, M. R.

2018-03-01

Aims.Ground-based observations at thermal infrared wavelengths suffer from large background radiation due to the sky, telescope and warm surfaces in the instrument. This significantly limits the sensitivity of ground-based observations at wavelengths longer than 3 μm. The main purpose of this work is to analyse this background emission in infrared high-contrast imaging data as illustrative of the problem, show how it can be modelled and subtracted and demonstrate that it can improve the detection of faint sources, such as exoplanets. Methods: We used principal component analysis (PCA) to model and subtract the thermal background emission in three archival high-contrast angular differential imaging datasets in the M' and L' filter. We used an M' dataset of β Pic to describe in detail how the algorithm works and explain how it can be applied. The results of the background subtraction are compared to the results from a conventional mean background subtraction scheme applied to the same dataset. Finally, both methods for background subtraction are compared by performing complete data reductions. We analysed the results from the M' dataset of HD 100546 only qualitatively. For the M' band dataset of β Pic and the L' band dataset of HD 169142, which was obtained with an angular groove phase mask vortex vector coronagraph, we also calculated and analysed the achieved signal-to-noise ratio (S/N). Results: We show that applying PCA is an effective way to remove spatially and temporarily varying thermal background emission down to close to the background limit. The procedure also proves to be very successful at reconstructing the background that is hidden behind the point spread function. In the complete data reductions, we find at least qualitative improvements for HD 100546 and HD 169142, however, we fail to find a significant increase in S/N of β Pic b. We discuss these findings and argue that in particular datasets with strongly varying observing conditions or

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

International Nuclear Information System (INIS)

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

2016-01-01

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 2014–2015 years). Median yearly CTC mixing ratios were slightly higher in the urban area (120 pptv) than in VNP (80–100 pptv). 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. - Highlights: • A methodology was developed to measure CTC using GC-MSD and GC-FID. • CTC ongoing sources were noticed in an industry surrounded urban area. • No noticeable nearby CTC sources impacted the rural site. • Long-term CTC trend in agreement

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

Energy Technology Data Exchange (ETDEWEB)

Blas, Maite de, E-mail: maite.deblas@ehu.eus [School of Engineering of Bilbao, University of the Basque Country UPV/EHU (Spain); Uria-Tellaetxe, Iratxe; Gomez, Maria Carmen [School of Engineering of Bilbao, University of the Basque Country UPV/EHU (Spain); Navazo, Marino [University College of Engineering of Vitoria-Gasteiz, University of the Basque Country UPV/EHU (Spain); Alonso, Lucio; García, Jose Antonio; Durana, Nieves; Iza, Jon; Ramón, Jarol Derley [School of Engineering of Bilbao, University of the Basque Country UPV/EHU (Spain)

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 2014–2015 years). Median yearly CTC mixing ratios were slightly higher in the urban area (120 pptv) than in VNP (80–100 pptv). 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. - Highlights: • A methodology was developed to measure CTC using GC-MSD and GC-FID. • CTC ongoing sources were noticed in an industry surrounded urban area. • No noticeable nearby CTC sources impacted the rural site. • Long-term CTC trend in agreement

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.

Annual radiation background in Isfahan city

International Nuclear Information System (INIS)

Tavakoli, Mohammad B.

2002-01-01

Measurement of environmental exposure is very important from different points of view. It is especially important for human health. It has been measured accurately in many countries. In Iran, it is also measured in some cities especially in high background areas such as Ramsar, but there is not any measurement in Isfahan. Measurement of background radiation in this study is performed using TLD method. The TLDs used are made from CaSO 4 :Dy, which is very sensitive. The locations under investigations in this research were 52 health centers distributed all around Isfahan city. Each TLD badge was put in a special plastic bag and left over the roofs of the selected health center for a month. The procedure was repeated for all 12 months of the year 1379(21 st March 2000 to 20 th March 2001). The results were used to obtain mean and SD in each month and at different places. The maximum and the minimum of obtained results for dose equivalent in different months and locations were 15.9x10 -2 and 6.5x10 -2 mSv. Obtained maximum and minimum of the means between all the locations were 10.5x10 -2 and 8.6x10 2 mSv for the whole year. Monthly mean and SD for Isfahan city for the whole year were 9.7x10 -2 and 1.5x10 -2 respectively therefore mean annual dose equivalent in Isfahan city is 1.16mSv. The results do not show any high background radiation area

Gamma-Ray Background Variability in Mobile Detectors

Science.gov (United States)

Aucott, Timothy John

Gamma-ray background radiation significantly reduces detection sensitivity when searching for radioactive sources in the field, such as in wide-area searches for homeland security applications. Mobile detector systems in particular must contend with a variable background that is not necessarily known or even measurable a priori. This work will present measurements of the spatial and temporal variability of the background, with the goal of merging gamma-ray detection, spectroscopy, and imaging with contextual information--a "nuclear street view" of the ubiquitous background radiation. The gamma-ray background originates from a variety of sources, both natural and anthropogenic. The dominant sources in the field are the primordial isotopes potassium-40, uranium-238, and thorium-232, as well as their decay daughters. In addition to the natural background, many artificially-created isotopes are used for industrial or medical purposes, and contamination from fission products can be found in many environments. Regardless of origin, these backgrounds will reduce detection sensitivity by adding both statistical as well as systematic uncertainty. In particular, large detector arrays will be limited by the systematic uncertainty in the background and will suffer from a high rate of false alarms. The goal of this work is to provide a comprehensive characterization of the gamma-ray background and its variability in order to improve detection sensitivity and evaluate the performance of mobile detectors in the field. Large quantities of data are measured in order to study their performance at very low false alarm rates. Two different approaches, spectroscopy and imaging, are compared in a controlled study in the presence of this measured background. Furthermore, there is additional information that can be gained by correlating the gamma-ray data with contextual data streams (such as cameras and global positioning systems) in order to reduce the variability in the background

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

International Nuclear Information System (INIS)

Hendry, Jolyon H; Sohrabi, Mehdi; Burkart, Werner; Simon, Steven L; Wojcik, Andrzej; Cardis, Elisabeth; Laurier, Dominique; Tirmarche, Margot; Hayata, Isamu

2009-01-01

Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of 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.

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

Science.gov (United States)

Hendry, Jolyon H; Simon, Steven L; Wojcik, Andrzej; Sohrabi, Mehdi; Burkart, Werner; Cardis, Elisabeth; Laurier, Dominique; Tirmarche, Margot; Hayata, Isamu

2014-01-01

Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of 222Rn 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. PMID:19454802

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.

Cosmic microwave background distortions at high frequencies

International Nuclear Information System (INIS)

Peter, W.; Peratt, A.L.

1988-01-01

The authors analyze the deviation of the cosmic background radiation spectrum from the 2.76+-0.02 0 Κ blackbody curve. If the cosmic background radiation is due to absorption and re-emission of synchrotron radiation from galactic-width current filaments, higher-order synchrotron modes are less thermalized than lower-order modes, causing a distortion of the blackbody curve at higher frequencies. New observations of the microwave background spectrum at short wavelengths should provide an indication of the number of synchrotron modes thermalized in this process. The deviation of the spectrum from that of a perfect blackbody can thus be correlated with astronomical observations such as filament temperatures and electron energies. The results are discussed and compared with the theoretical predictions of other models which assume the presence of intergalactic superconducting cosmic strings

On the frequency dependence of the high temperature background

International Nuclear Information System (INIS)

Povolo, F.; Hermida, E.B.

1996-01-01

The high temperature background (HTB) damping in metals and alloys has been measured mostly as a function of temperature. These data were described by several empirical expressions proposed in the literature. In the present work, HTB in pure Mg and in two alloys (Zry-4 and Cu-5 at.%Au), measured with a torsion pendulum with variable moment of inertia, are analyzed on considering a new treatment of the data. This analysis provides an useful tool to determine whether a damping process is linear or not. (orig.)

Natural background radiation exposures world-wide

International Nuclear Information System (INIS)

Bennett, B.G.

1993-01-01

The average radiation dose to the world's population from natural radiation sources has been assessed by UNSCEAR to be 2.4 mSv per year. The components of this exposure, methods of evaluation and, in particular, the variations in the natural background levels are presented in this paper. Exposures to cosmic radiation range from 0.26 mSv per year at sea level to 20 times more at an altitude of 6000 m. Exposures to cosmogenic radionuclides ( 3 H, 14 C) are relatively insignificant and little variable. The terrestrial radionuclides 40 K, 238 U, and 232 Th and the decay products of the latter two constitute the remainder of the natural radiation exposure. Wide variations in exposure occur for these components, particularly for radon and its decay products, which can accumulate to relatively high levels indoors. Unusually high exposures to uranium and thorium series radionuclides characterize the high natural background areas which occur in several localized regions in the world. Extreme values in natural radiation exposures have been estimated to range up to 100 times the average values. (author). 15 refs, 3 tabs

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)

Esaiselvan, K.; Rajagopal, R.; Sreekumar, K.; Harikumar, M.; AllenGnanaraj, G.

2010-01-01

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 ( 222 Rn), thoron ( 220 Rn) 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 232 Th 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)

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)

Astronomy: social background of students of the integrated high school

Science.gov (United States)

Voelzke, M. R.; Barbosa, J. I. L.

2017-07-01

Astronomy-related contents exist in almost all levels of basic education in Brazil and are also frequently disseminated through mass media. Thus, students form their own explanations about the phenomena studied by this science. Therefore, this work has the objective of identifying the possible social background of the Integrated High School students on the term Astronomy. It is a research of a basic nature, descriptive, and for that reason a quali-quantitative approach was adopted; the procedures to obtain the data were effected in the form of a survey. The results show that the tested students have a social background about the object Astronomy, which is on the one hand fortified by elements they have made or which is part of the experience lived by the respondents within the formal space of education, and on the other hand based on elements possibly disseminated through the mass media.

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

Measurements of radiological background and some chemical pollutants in two areas of greater cairo

International Nuclear Information System (INIS)

Tawfik, F.S.; Ramadan, A.; Abdel Aziz, M.A.; Aly, A.I.M.

2002-01-01

The present work aims to the evaluation of radiological background levels and chemical pollutants in greater cairo as the most dense populated city in Egypt. The meteorological data of a complete one year of Cairo city have been collected, investigated and processed to determined the behavior of the pollutants in the atmosphere and the sector that is strongly affected by the pollutants. Portable detector for measuring the radiological background was deployed in Nasr City, where two nuclear centers belonging to Atomic Energy Authority are located, to measure the radioactivity levels in the atmosphere and compare them with the international standard limits. Other detectors were deployed in Shobra El- Khema area to study two significant phenomena, the first is the formation of ozone through the photo-chemical oxidation, its level and its behavior in the atmosphere, taking into consideration the international standard limits. The second phenomenon is the impact of the black plume on the capital Cairo started on October (1999) and its association of pollutant levels increment, defining the nature and the site location of the pollutant source. The carbon monoxide concentrations (as an example), before and during the black plume, were calculated using Gaussian equation then compared with the measured data in Shobra El- Khema region. The other available instruments were used to measure nitrogen oxides, ozone and carbon monoxide

Radiological assessment of residences in the Oak Ridge area. Volume 1. Background information for ORNL environmental impact statement

International Nuclear Information System (INIS)

Tsakeres, F.S.; Shank, K.E.; Chaudhry, M.Y.; Ahmad, S.; DiZillo-Benoit, P.M.; Oakes, T.W.

1980-10-01

Measurements of exposure rates using thermoluminescent dosimeters placed within residences in the Oak Ridge/Knoxville area are presented. The objective of this investigation was to determine the radiation component acquired by Oak Ridge National Laboratory employee personnel dosimeter-security badges during residential badge storage and to develop a model to predict the radiation exposure rate in Oak Ridge/Knoxville-area homes. The exposure rates varied according to building material used and geographic location. Exposure rates were higher in the fall and lower in the spring; stone residences had a higher average dose equivalent rate than residences made of wood. An average yearly exposure rate was determined to be 78 millirems per year for the Oak Ridge-area homes. This value can be compared to the natural background radiation dose equivalent rate in the United States of 80 to 200 millirems per year

Attitudes, Values and Background of High School Journalists Compared with the Media Elite.

Science.gov (United States)

Johnson, Sammye

To compare attitudes, values, and background of high school journalists with those of the media elite (journalists already working in the media), a survey was administered to 132 public and private high school students attending the Trinity University Journalism Institute during June 5-9, 1983. These students were the editors of their newspapers,…

Hanford Site background: Part 1, Soil background for nonradioactive analytes

International Nuclear Information System (INIS)

1993-04-01

The determination of soil background is one of the most important activities supporting environmental restoration and waste management on the Hanford Site. Background compositions serve as the basis for identifying soil contamination, and also as a baseline in risk assessment processes used to determine soil cleanup and treatment levels. These uses of soil background require an understanding of the extent to which analytes of concern occur naturally in the soils. This report documents the results of sampling and analysis activities designed to characterize the composition of soil background at the Hanford Site, and to evaluate the feasibility for use as Sitewide background. The compositions of naturally occurring soils in the vadose Zone have been-determined for-nonradioactive inorganic and organic analytes and related physical properties. These results confirm that a Sitewide approach to the characterization of soil background is technically sound and is a viable alternative to the determination and use of numerous local or area backgrounds that yield inconsistent definitions of contamination. Sitewide soil background consists of several types of data and is appropriate for use in identifying contamination in all soils in the vadose zone on the Hanford Site. The natural concentrations of nearly every inorganic analyte extend to levels that exceed calculated health-based cleanup limits. The levels of most inorganic analytes, however, are well below these health-based limits. The highest measured background concentrations occur in three volumetrically minor soil types, the most important of which are topsoils adjacent to the Columbia River that are rich in organic carbon. No organic analyte levels above detection were found in any of the soil samples

Study of radiation background at various high altitude locations in preparation for rare event search in cosmic rays

Energy Technology Data Exchange (ETDEWEB)

Bhattacharyya, R.; Dey, S.; Ghosh, Sanjay K.; Maulik, A.; Raha, Sibaji; Syam, D., E-mail: rupamoy@gmail.com, E-mail: dey_s2001@yahoo.com, E-mail: sanjay@jcbose.ac.in, E-mail: atanu.maulik@jcbose.ac.in, E-mail: sibaji.raha@jcbose.ac.in, E-mail: syam.debapriyo@gmail.com [Centre for Astroparticle Physics and Space Science, Bose Institute, Block-EN, Sector-V, Kolkata-700091 (India)

2017-04-01

Various phenomenological models presented over the years have hinted at the possible presence of strangelets, which are nuggets of Strange Quark Matter (SQM), in cosmic rays. One way to search for such rare events is through the deployment of large area Nuclear Track Detector (NTD) arrays at high mountain altitudes. Before the deployment of any such array can begin, a detailed study of the radiation background is essential. Also, a proper understanding of the response of detectors exposed to extreme weather conditions is necessary. With that aim, pilot studies were carried out at various high altitude locations in India such as Darjeeling (2200 m a.m.s.l), Ooty (2200 m a.m.s.l) and Hanle (4500 m a.m.s.l). Small arrays of CR-39 as well as high threshold Polyethylene Terephthalate (PET) detectors were given open air exposures for periods ranging from three months to two years. The findings of such studies are reported in this paper.

Extragalactic background light measurements and applications.

Science.gov (United States)

Cooray, Asantha

2016-03-01

This review covers the measurements related to the extragalactic background light intensity from γ-rays to radio in the electromagnetic spectrum over 20 decades in wavelength. The cosmic microwave background (CMB) remains the best measured spectrum with an accuracy better than 1%. The measurements related to the cosmic optical background (COB), centred at 1 μm, are impacted by the large zodiacal light associated with interplanetary dust in the inner Solar System. The best measurements of COB come from an indirect technique involving γ-ray spectra of bright blazars with an absorption feature resulting from pair-production off of COB photons. The cosmic infrared background (CIB) peaking at around 100 μm established an energetically important background with an intensity comparable to the optical background. This discovery paved the way for large aperture far-infrared and sub-millimetre observations resulting in the discovery of dusty, starbursting galaxies. Their role in galaxy formation and evolution remains an active area of research in modern-day astrophysics. The extreme UV (EUV) background remains mostly unexplored and will be a challenge to measure due to the high Galactic background and absorption of extragalactic photons by the intergalactic medium at these EUV/soft X-ray energies. We also summarize our understanding of the spatial anisotropies and angular power spectra of intensity fluctuations. We motivate a precise direct measurement of the COB between 0.1 and 5 μm using a small aperture telescope observing either from the outer Solar System, at distances of 5 AU or more, or out of the ecliptic plane. Other future applications include improving our understanding of the background at TeV energies and spectral distortions of CMB and CIB.

A statistical background noise correction sensitive to the steadiness of background noise.

Science.gov (United States)

Oppenheimer, Charles H

2016-10-01

A statistical background noise correction is developed for removing background noise contributions from measured source levels, producing a background noise-corrected source level. Like the standard background noise corrections of ISO 3741, ISO 3744, ISO 3745, and ISO 11201, the statistical background correction increases as the background level approaches the measured source level, decreasing the background noise-corrected source level. Unlike the standard corrections, the statistical background correction increases with steadiness of the background and is excluded from use when background fluctuation could be responsible for measured differences between the source and background noise levels. The statistical background noise correction has several advantages over the standard correction: (1) enveloping the true source with known confidence, (2) assuring physical source descriptions when measuring sources in fluctuating backgrounds, (3) reducing background corrected source descriptions by 1 to 8 dB for sources in steady backgrounds, and (4) providing a means to replace standardized background correction caps that incentivize against high precision grade methods.

Serratia sp. ZF03: an efficient radium biosorbent isolated from hot-spring waters in high background radiation areas of Ramsar

International Nuclear Information System (INIS)

Zakeri, F.; Sadeghizadeh, M.; Akbari Noghabi, K.; Farshidpour, M.R.; Kardan, M.R.; Atarilar, A.

2010-01-01

Natural radionuclides, in particular those emitting alpha particles, make the largest contribution to the world population exposure. The most important example is 226 Ra, with a high potency for causing biological damages. Accordingly, it can be a potential concern in many areas, where these elements have been existed naturally, mined or processed. In addition to its own radiological properties, radium isotopes present additional environmental and health concerns due to the fact that they decay into radon ( 222 Rn); a Class-A carcinogen and the second leading cause of lung cancer estimated to cause 21,000 deaths in the US annually. Physico-chemical methods have been widely used to remove radionuclides and heavy metal ions from wastewaters. These conventional methods may be ineffective or expensive with a few major disadvantages such as high energy requirements, incomplete removal and generation of toxic sludge which needs proper disposal. Biological treatment is an innovative technology available for heavy metal and radionuclide polluted wastewaters. The aim of this study was to isolate and characterize 226 Ra biosorbing indigenous bacterial strains from soils and hot-springs of Ramsar containing high concentration of 226 Ra by using biochemical and molecular approaches. Hence, the studied biomass proved very effective and could be used as a low cost and ecofriendly biosorbent for treatment of hot-spring waters containing high levels of 226 Ra in Ramsar

Background field coils for the High Field Test Facility

International Nuclear Information System (INIS)

Zbasnik, J.P.; Cornish, D.N.; Scanlan, R.M.; Jewell, A.M.; Leber, R.L.; Rosdahl, A.R.; Chaplin, M.R.

1980-01-01

The High Field Test Facility (HFTF), presently under construction at LLNL, is a set of superconducting coils that will be used to test 1-m-o.d. coils of prototype conductors for fusion magnets in fields up to 12 T. The facility consists of two concentric sets of coils; the outer set is a stack of Nb-Ti solenoids, and the inner set is a pair of solenoids made of cryogenically-stabilized, multifilamentary Nb 3 Sn superconductor, developed for use in mirror-fusion magnets. The HFTF system is designed to be parted along the midplane to allow high-field conductors, under development for Tokamak fusion machines, to be inserted and tested. The background field coils were wound pancake-fashion, with cold-welded joints at both the inner and outer diameters. Turn-to-turn insulation was fabricated at LLNL from epoxy-fiberglass strip. The coils were assembled and tested in our 2-m-diam cryostat to verify their operation

Differentiation of specific ripple patterns helps to identify epileptogenic areas for surgical procedures.

Science.gov (United States)

Kerber, Karolin; Dümpelmann, Matthias; Schelter, Björn; Le Van, Pierre; Korinthenberg, Rudolf; Schulze-Bonhage, Andreas; Jacobs, Julia

2014-07-01

High frequency oscillations (HFOs) at 80-500 Hz are promising markers of epileptic areas. Several retrospective studies reported that surgical removal of areas generating HFOs was associated with a good seizure outcome. Recent reports suggested that ripple (80-200 Hz) HFO patterns co-existed with different background EEG activities. We hypothesized that the coexisting background EEG pattern may distinguish physiological from epileptic ripples. Rates of HFOs were analyzed in intracranial EEG recordings of 22 patients. Additionally, ripple patterns were classified for each channel depending either as coexisting with a flat or oscillatory background activity. A multi-variate analysis was performed to determine whether removal of areas showing the above EEG markers correlated with seizure outcome. Removal of areas generating high rates of 'fast ripples (>200 Hz)' and 'ripples on a flat background activity' showed a significant correlation with a seizure-free outcome. In contrast, removal of high rates of 'ripples' or 'ripple patterns in a continuously oscillating background' was not significantly associated with seizure outcome. Ripples occurring in an oscillatory background activity may be suggestive of physiological activity, while those on a flat background reflect epileptic activity. Consideration of coexisting background patterns may improve the delineation of the epileptogenic areas using ripple oscillations. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Infrared Thermography Approach for Effective Shielding Area of Field Smoke Based on Background Subtraction and Transmittance Interpolation.

Science.gov (United States)

Tang, Runze; Zhang, Tonglai; Chen, Yongpeng; Liang, Hao; Li, Bingyang; Zhou, Zunning

2018-05-06

Effective shielding area is a crucial indicator for the evaluation of the infrared smoke-obscuring effectiveness on the battlefield. The conventional methods for assessing the shielding area of the smoke screen are time-consuming and labor intensive, in addition to lacking precision. Therefore, an efficient and convincing technique for testing the effective shielding area of the smoke screen has great potential benefits in the smoke screen applications in the field trial. In this study, a thermal infrared sensor with a mid-wavelength infrared (MWIR) range of 3 to 5 μm was first used to capture the target scene images through clear as well as obscuring smoke, at regular intervals. The background subtraction in motion detection was then applied to obtain the contour of the smoke cloud at each frame. The smoke transmittance at each pixel within the smoke contour was interpolated based on the data that was collected from the image. Finally, the smoke effective shielding area was calculated, based on the accumulation of the effective shielding pixel points. One advantage of this approach is that it utilizes only one thermal infrared sensor without any other additional equipment in the field trial, which significantly contributes to the efficiency and its convenience. Experiments have been carried out to demonstrate that this approach can determine the effective shielding area of the field infrared smoke both practically and efficiently.

Infrared Thermography Approach for Effective Shielding Area of Field Smoke Based on Background Subtraction and Transmittance Interpolation

Directory of Open Access Journals (Sweden)

Runze Tang

2018-05-01

Full Text Available Effective shielding area is a crucial indicator for the evaluation of the infrared smoke-obscuring effectiveness on the battlefield. The conventional methods for assessing the shielding area of the smoke screen are time-consuming and labor intensive, in addition to lacking precision. Therefore, an efficient and convincing technique for testing the effective shielding area of the smoke screen has great potential benefits in the smoke screen applications in the field trial. In this study, a thermal infrared sensor with a mid-wavelength infrared (MWIR range of 3 to 5 μm was first used to capture the target scene images through clear as well as obscuring smoke, at regular intervals. The background subtraction in motion detection was then applied to obtain the contour of the smoke cloud at each frame. The smoke transmittance at each pixel within the smoke contour was interpolated based on the data that was collected from the image. Finally, the smoke effective shielding area was calculated, based on the accumulation of the effective shielding pixel points. One advantage of this approach is that it utilizes only one thermal infrared sensor without any other additional equipment in the field trial, which significantly contributes to the efficiency and its convenience. Experiments have been carried out to demonstrate that this approach can determine the effective shielding area of the field infrared smoke both practically and efficiently.

Temperature dependence of the effective sensing area of high-Tc dc SQUIDs

International Nuclear Information System (INIS)

Brake, H.J.M. ter; Aarnink, W.A.M.; Bosch, P.J. van den; Hilgenkamp, J.W.M.; Flokstra, J.; Rogalla, H.

1997-01-01

The effective sensing area of a high-T c dc SQUID depends on temperature. As a consequence, fluctuations in the operating temperature result in apparent magnetic field noise if the SQUID is placed in a background magnetic field. An analysis of this effect for two SQUID types, the square-washer 'Ketchen' type and the inductively shunted type, is performed. For magnetocardiography, the temperature fluctuations (peak to peak) of the latter SQUID type should be below w 0.3 mK at 77 K, and below 2 mK at 55 K, with an earth's field suppression of 40 dB. For the square-washer SQUID the requirements are about 8 times less stringent. (author)

Establishing geochemical background levels of selected trace elements in areas having geochemical anomalies: The case study of the Orbetello lagoon (Tuscany, Italy)

International Nuclear Information System (INIS)

Romano, Elena; Bergamin, Luisa; Croudace, Ian W.; Ausili, Antonella; Maggi, Chiara; Gabellini, Massimo

2015-01-01

The determination of background concentration values (BGVs) in areas, characterised by the presence of natural geochemical anomalies and anthropogenic impact, appears essential for a correct pollution assessment. For this purpose, it is necessary to establish a reliable method for determination of local BGVs. The case of the Orbetello lagoon, a geologically complex area characterized by Tertiary volcanism, is illustrated. The vertical concentration profiles of As, Cd, Cr, Cu, Hg, Ni, Pb and Zn were studied in four sediment cores. Local BGVs were determined considering exclusively samples not affected by anthropogenic influence, recognized by means of multivariate statistics and radiochronological dating ( 137 Cs and 210 Pb). Results showed BGVs well-comparable with mean crustal or shale values for most of the considered elements except for Hg (0.87 mg/kg d.w.) and As (16.87 mg/kg d.w.), due to mineralization present in the catchment basin draining into the lagoon. - Highlights: • Pollution assessment in areas with geochemical anomalies needs local reference values. • A new method for the determination of background values (BGV) was established. • Geochemical data from unpolluted samples of sediment cores were used. • Statistics and geochronology were applied to recognize unpolluted sediments. • Anthropogenically influenced samples were not considered for BGV determination. - A method including multivariate statistics and radiochronological dating is proposed for determining local background values for trace elements using analytical data form sediment cores

Large area high-speed metrology SPM system

International Nuclear Information System (INIS)

Klapetek, P; Valtr, M; Martinek, J; Picco, L; Payton, O D; Miles, M; Yacoot, A

2015-01-01

We present a large area high-speed measuring system capable of rapidly generating nanometre resolution scanning probe microscopy data over mm 2 regions. The system combines a slow moving but accurate large area XYZ scanner with a very fast but less accurate small area XY scanner. This arrangement enables very large areas to be scanned by stitching together the small, rapidly acquired, images from the fast XY scanner while simultaneously moving the slow XYZ scanner across the region of interest. In order to successfully merge the image sequences together two software approaches for calibrating the data from the fast scanner are described. The first utilizes the low uncertainty interferometric sensors of the XYZ scanner while the second implements a genetic algorithm with multiple parameter fitting during the data merging step of the image stitching process. The basic uncertainty components related to these high-speed measurements are also discussed. Both techniques are shown to successfully enable high-resolution, large area images to be generated at least an order of magnitude faster than with a conventional atomic force microscope. (paper)

Large area high-speed metrology SPM system

Science.gov (United States)

Klapetek, P.; Valtr, M.; Picco, L.; Payton, O. D.; Martinek, J.; Yacoot, A.; Miles, M.

2015-02-01

We present a large area high-speed measuring system capable of rapidly generating nanometre resolution scanning probe microscopy data over mm2 regions. The system combines a slow moving but accurate large area XYZ scanner with a very fast but less accurate small area XY scanner. This arrangement enables very large areas to be scanned by stitching together the small, rapidly acquired, images from the fast XY scanner while simultaneously moving the slow XYZ scanner across the region of interest. In order to successfully merge the image sequences together two software approaches for calibrating the data from the fast scanner are described. The first utilizes the low uncertainty interferometric sensors of the XYZ scanner while the second implements a genetic algorithm with multiple parameter fitting during the data merging step of the image stitching process. The basic uncertainty components related to these high-speed measurements are also discussed. Both techniques are shown to successfully enable high-resolution, large area images to be generated at least an order of magnitude faster than with a conventional atomic force microscope.

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.

Correlation Among Students’ Family Background, Academic Performance in Junior High School, and Senior High School Tracking in Taiwan

Directory of Open Access Journals (Sweden)

Ming-Fu Huang

2014-12-01

Full Text Available There were numerous previous studies on educational tracking. However, most of the data adopted in these studies were collected a decade ago, involving sample population 20-64 years of age. Among them, many elderly samples had undergone senior high school tracking in the early years. The present study used the data of students and parents from the 3rd wave (2005 of the Taiwan Education Panel Survey (TEPS. A path analysis was conducted to investigate the inequality of opportunities involved in the influence of student family background on educational tracking at the senior high school stage. The results show: although the overall percentage of junior high school graduates entering advanced levels was approximately 100% and almost all students of different family backgrounds entered advanced levels, the most crucial factor among those affecting educational tracking of senior high school stage was students’ academic performance during junior high school. Students with higher family socioeconomic status and fewer siblings showed better academic performance in junior high schools, and consequently had higher possibilities of entering public senior high schools leading to a more promising future. This indicates that though the inequality in the quantity of opportunities approached 0, the inequality in the quality of opportunities still remained, which fails to support the hypothesis of the maximally maintained inequality of educational opportunity (MMI; however, the result supports the hypothesis of the effectively maintained inequality of educational opportunity (EMI.

Optimal Background Attenuation for Fielded Radiation Detection Systems

International Nuclear Information System (INIS)

Robinson, Sean M.; Kaye, William R.; Schweppe, John E.; Siciliano, Edward R.

2006-01-01

Radiation detectors are often placed in positions difficult to shield from the effects of terrestrial background. This is particularly true in the case of Radiation Portal Monitor (RPM) systems, as their wide viewing angle and outdoor installations make them susceptible to terrestrial background from the surrounding area. A low background is desired in most cases, especially when the background noise is of comparable strength to the signal of interest. The problem of shielding a generalized RPM from terrestrial background is considered. Various detector and shielding scenarios are modeled with the Monte-Carlo N Particle (MCNP) computer code. Amounts of nominal-density shielding needed to attenuate the terrestrial background to varying degrees are given, along with optimal shielding geometry to be used in areas where natural shielding is limited, and where radiation detection must occur in the presence of natural background. Common shielding solutions such as steel plating are evaluated based on the signal to noise ratio and the benefits are weighed against the incremental cost.

High Spectral Resolution Observation of the Soft Diffuse X-ray Background in the Direction of the Galactic Anti-Center

Science.gov (United States)

Wulf, Dallas; Eckart, Mega E.; Galeazzi, Massimiliano; Jaeckel, Felix; Kelley, Richard L.; Kilbourne, Caroline A.; McCammon, Dan; Morgan, Kelsey M.; Porter, Frederick S.; Szymkowiak, Andrew E.

2018-01-01

High spectral resolution observations in the soft x-rays are necessary for understanding and modelling the hot component of the interstellar medium and its contribution to the Soft X-ray Background (SXRB). This extended source emission cannot be resolved with most wavelength dispersive spectrometers, making energy dispersive microcalorimeters the ideal choice for these observations. We present here the analysis of the most recent sounding rocket flight of the University of Wisconsin-Madison/Goddard Space Flight Center X-ray Quantum Calorimeter (XQC), a large area silicon thermistor microcalorimeter. This 111 second observation integrates a nearly 1 steradian field of view in the direction of the galactic anti-center (l, b = 165°, -5°) and features ~5 eV spectral resolution below 1 keV. Direct comparison will also be made to the previous, high-latitude observations.

A new procedure to determine Radium 226 in foodstuff especially at high natural radioactive area of Ramsar

International Nuclear Information System (INIS)

Hosseini, T.

1993-01-01

Micro-co precipitate of barium-radium sulfate with the thickness of 3.98 μ/Cm Ba 2 is prepared to be counted by electrochemically etched polycarbonate detectors. By the use of the standard micro-co precipitating, sample-detector distance was determined and the calibration curve of track density vs. 226 R a radioactivity was drawn. The food samples were ashed and 226 R a was co-precipitated with Barium carrier. After radioactivity equilibrium between 226 R a and its daughter products, the polycarbonate detectors were exposed for a certain period of time from filters having micro-co precipitates of Ba(Ra)SO-4. The track density is proportional to the 226 R a radioactivity as calibrated. About 80 samples of vegetables, tea leaves, oranges, milk, and eggs from high level natural radiation areas of Ramsar were collected and co precipitated. The results were compared with those obtained from emanation method for the named samples showing up to 52% consistency in the measurements, Also comparison was made between the average 226 R a in samples of high natural radiation areas of Ramsar with the background levels. The results indicated that the amount of 226 R a in oranges, vegetables and eggs are 1.9, 3.3 and 6 times higher than that of background respectively. The advantages of this method are as follows: measuring time in the other methods for one sample is high; but, in this method many samples can be measured simultaneously for long time. As the low thickness of precipitate the self-absorption of alpha particle in micro-co precipitate reduces very much in comparison with the old method. The particles in micro-co precipitates are uniform to cause the increase of track density. In new method as the long time of exposure the background counts are reduced, and finally it is simple and inexpensive

High-Intensity Focused Ultrasound for the Treatment of Wrinkles and Skin Laxity in Seven Different Facial Areas

OpenAIRE

Park, Hyunchul; Kim, Eunjin; Kim, Jeongeun; Ro, Youngsuck; Ko, Jooyeon

2015-01-01

Background High-intensity focused ultrasound (HIFU) treatment has recently emerged in response to the increasing demand for noninvasive procedures for skin lifting and tightening. Objective This study was aimed at evaluating the clinical efficacy of and patient satisfaction with HIFU treatment for wrinkles and laxity in seven different areas of the face in Asian skin. Methods Twenty Korean patients with facial wrinkle and laxity were analyzed after a single session of HIFU treatment. Two inde...

Aluminum as a source of background in low background experiments

Energy Technology Data Exchange (ETDEWEB)

Majorovits, B., E-mail: bela@mppmu.mpg.de [MPI fuer Physik, Foehringer Ring 6, 80805 Munich (Germany); Abt, I. [MPI fuer Physik, Foehringer Ring 6, 80805 Munich (Germany); Laubenstein, M. [Laboratori Nazionali del Gran Sasso, INFN, S.S.17/bis, km 18 plus 910, I-67100 Assergi (Italy); Volynets, O. [MPI fuer Physik, Foehringer Ring 6, 80805 Munich (Germany)

2011-08-11

Neutrinoless double beta decay would be a key to understanding the nature of neutrino masses. The next generation of High Purity Germanium experiments will have to be operated with a background rate of better than 10{sup -5} counts/(kg y keV) in the region of interest around the Q-value of the decay. Therefore, so far irrelevant sources of background have to be considered. The metalization of the surface of germanium detectors is in general done with aluminum. The background from the decays of {sup 22}Na, {sup 26}Al, {sup 226}Ra and {sup 228}Th introduced by this metalization is discussed. It is shown that only a special selection of aluminum can keep these background contributions acceptable.

Epidemiologic studies in the areas with a high level of natural radioactivity; Etudes epidemiologiques dans des zones a haut niveau de radioactivite naturelle

Energy Technology Data Exchange (ETDEWEB)

Laurier, D.; Martin, J.M.; Hubert, Ph

2000-10-01

Since 1970, numerous studies have been interested in high level of natural radiations areas (H.L.N.R.A.) or high background radiation areas (H.B.R.A.). An international conference stands every four years, and the last one was at Munich (Germany). The aim of this note is to make a review of epidemiologic studies made with the populations living in H.L.N.R.A. and to present a synthesis of achieved results. The cytogenetic studies are equally mentioned but not detailed. (N.C.)

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

International Nuclear Information System (INIS)

Monfared, A.S.; Mozdarani, H.; Amiri, M.

2003-01-01

Ramsar, a city in the northern Iran, has the highest level of natural background radiation in the world. It has been clearly shown that low doses of ionising radiation can induce resistance to subsequent higher exposures. This phenomenon is termed radioadaptive response. We have compared induction of cytogenetic radioadaptive response by High Natural Background Radiation (HNBR) in Ramsar and X-ray occupational exposure as conditioning doses in human peripheral blood lymphocytes. 30 healthy control individuals, living in Ramsar but in normal background radiation areas, 15 healthy individuals from Talesh Mahalleh, a region with extraordinary high level of background radiation, and 7 X-ray radiographers working in Ramsar hospital located in normal natural background ionising radiation area 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. An adaptive response was observed in HNBR and radiation workers groups in comparison with sham controls. A significant increase in adaptive response was observed in the HNBR group if compared with the occupationally exposed 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)

Background sources at PEP

International Nuclear Information System (INIS)

Lynch, H.; Schwitters, R.F.; Toner, W.T.

1988-01-01

Important sources of background for PEP experiments are studied. Background particles originate from high-energy electrons and positrons which have been lost from stable orbits, γ-rays emitted by the primary beams through bremsstrahlung in the residual gas, and synchrotron radiation x-rays. The effect of these processes on the beam lifetime are calculated and estimates of background rates at the interaction region are given. Recommendations for the PEP design, aimed at minimizing background are presented. 7 figs., 4 tabs

Peculiar velocity effects in high-resolution microwave background experiments

International Nuclear Information System (INIS)

Challinor, Anthony; Leeuwen, Floor van

2002-01-01

We investigate the impact of peculiar velocity effects due to the motion of the solar system relative to the cosmic microwave background (CMB) on high resolution CMB experiments. It is well known that on the largest angular scales the combined effects of Doppler shifts and aberration are important; the lowest Legendre multipoles of total intensity receive power from the large CMB monopole in transforming from the CMB frame. On small angular scales aberration dominates and is shown here to lead to significant distortions of the total intensity and polarization multipoles in transforming from the rest frame of the CMB to the frame of the solar system. We provide convenient analytic results for the distortions as series expansions in the relative velocity of the two frames, but at the highest resolutions a numerical quadrature is required. Although many of the high resolution multipoles themselves are severely distorted by the frame transformations, we show that their statistical properties distort by only an insignificant amount. Therefore, the cosmological parameter estimation is insensitive to the transformation from the CMB frame (where theoretical predictions are calculated) to the rest frame of the experiment

Health effects in residents of high background radiation regions

International Nuclear Information System (INIS)

Hanson, G.P.; Komarov, E.

1983-01-01

Studies carried out in various countries and by the World Health Organization on health effects of exposure of populations to high levels of natural background radiation result in observations of different significance. There are indications of changes in chromosome aberration rate; Down's syndrome has been observed to be possibly related to radiation exposure; malignant neoplasms in bone apparently correspond to high concentrations of 226 Ra in drinking water. Although various researchers have looked for them, effects have not been demonstrated regarding cancer mortality (other than malignant neoplasms involving bone), gross congenital abnormalities, fertility index, growth and development, hereditary disease (other than the possibility of Down's syndrome), infant mortality, longevity, multiple births, sex ratio, or spontaneous abortion rate. On the basis of reported data clear quantitative conception of the risk of low-level radiation from natural sources could not be developed and feasibility studies of further epidemiological programmes should be organized. The possibility of reducing the collective population dose from natural sources could be further explored and a basis for necessary legal action on establishment of standards for possible sources of natural radiation, such as building materials, fertilizers, natural gas and water, might be developed. (author)

Study of the CMS RPC detector performance in high radiation background conditions

CERN Document Server

Miguel Colin, Osvaldo

2017-01-01

The RPC system at the CMS Detector is operating successfully from beginning of the data taking. The high instantaneous luminosity causes an extremely high flux of ionizing particles. The long period of operation (Run1 and Run2) in a huge radiation background conditions, gives the opportunity to study the operation capability of the RPCs and also to predict a data-driven extrapolation about the expecting particle rates at HL LHC (High Luminosity) scenario. The obtained results in terms of measured rate, currents and integrated charged will be presented in the poster. When it is possible they will be compared to the relevant results obtained from the dedicated study where a set of test chambers have been irradiated at GIF++ laboratory setup.

State Recognition of High Voltage Isolation Switch Based on Background Difference and Iterative Search

Science.gov (United States)

Xu, Jiayuan; Yu, Chengtao; Bo, Bin; Xue, Yu; Xu, Changfu; Chaminda, P. R. Dushantha; Hu, Chengbo; Peng, Kai

2018-03-01

The automatic recognition of the high voltage isolation switch by remote video monitoring is an effective means to ensure the safety of the personnel and the equipment. The existing methods mainly include two ways: improving monitoring accuracy and adopting target detection technology through equipment transformation. Such a method is often applied to specific scenarios, with limited application scope and high cost. To solve this problem, a high voltage isolation switch state recognition method based on background difference and iterative search is proposed in this paper. The initial position of the switch is detected in real time through the background difference method. When the switch starts to open and close, the target tracking algorithm is used to track the motion trajectory of the switch. The opening and closing state of the switch is determined according to the angle variation of the switch tracking point and the center line. The effectiveness of the method is verified by experiments on different switched video frames of switching states. Compared with the traditional methods, this method is more robust and effective.

The calculation of absorbed dose rate in freshwater fish from high background natural radioactivity areas

International Nuclear Information System (INIS)

Pereira, W.S.; Moraes, S.R.; Cavalcante, J.J.V.; Pinto, C.E.C.; Kelecom, A.

2017-01-01

Areas of increased radiation may expose biota to radiation doses greater than the world averages, and depending on the magnitude of the exposure causing biota damage. The region of the municipality of Caldas, MG, BR is considered a region of increased natural radioactivity. The present work aims to evaluate the exposure of biota to natural radionuclides in the region of Caldas, MG. In order to evaluate the biota exposure in the region, the concentrations of the natural radionuclides U nat , 226 Ra, 210 Pb and 232 Th and 228 Ra were evaluated in two species of fishes: lambari (Astymax spp.) And traíra (Hoplias spp.). The dose rates of the analyzed fish were: for Astymax spp of 0.08 μGy d -1 and for Hoplias spp of 0.12 μGy∙d -1 . With these dose rate values no measurable deleterious effects are expected in the species studied

Application of subinterval area median contrast filtering method in the recognizing of geochemical anomalies

International Nuclear Information System (INIS)

Zhao Ningbo; Fu Jin; Zhang Chuan; Liu Huan

2012-01-01

Traditional geochemical processing method sometimes maybe loses some weak anomalies related to mineralization, the authors can avoid the influence of geology background and can solve the problem of recognizing weak anomalies in the low-background and high-background area with the subinterval area median contrast filtering method. In an area of Jiangxi Province, several new anomalies are identified by this method and uranium mineralized prospects are found among them. (authors)

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)

Maniyan, C.G.; Selvan, Esai; Tripathi, R.M.; Puranik, V.D.

2007-01-01

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)

The determination and use of radionuclide background in gamma spectrometry

International Nuclear Information System (INIS)

Zimmer, W.H.

1986-01-01

Background is the major component of gross photon peak area. Therefore, net area, nuclide activity, counting uncertainty, and limits of detection calculations are no better than the calculation of background. In this study, background in gamma spectrometry is explored in several of its aspects. Means are presented to reduce background. Standard practices are presented to be used in the acquisition of valid, relevant background data. Unified standard calculations with examples are presented in the use of background data to determine net count and counting uncertainty. L. A. Currie's latest calculations of Lower Limits of Detection (1) (LLD) as they apply to gamma spectrometry are reviewed. Finally, Maximum Undetected Activity (MUA), LLD, and Critical Level (CL) concepts and calculations are compared in sample spectra

Using the IEC Standard to Describe Low-Background Detectors-What Can You Expect?

International Nuclear Information System (INIS)

Ronald M. Keyser; Sanford Wagner

1998-01-01

The new International Electrotechnical Commission (IEC) standard for describing the background makes the specification of the background in a high-purity germanium (HPGe) detector simple, unambiguous, and related to how the detector will be used. Users and manufacturers will finally be speaking the same language on this subject. Because this standard extends the specification of the performance of an HPGe detector, there is little history available for comparison and thus no means of determining a ''good'' value. To develop a history, the background spectrum for 500 low-background HPGe ORTEC detectors were all counted in similar low-background shields. These detectors were in a variety of mechanical cryostat and endcap configurations. The continuum background is a function of energy and detector size/configuration. The peak area for the peak energies listed in the standard is a function of detector size and configuration. The results thus give practical guidance for obtaining the most appropriate low-background detector for a specific measurement problem

Identification of high risk areas for avian influenza outbreaks in California using disease distribution models.

Directory of Open Access Journals (Sweden)

Jaber Belkhiria

Full Text Available The coexistence of different types of poultry operations such as free range and backyard flocks, large commercial indoor farms and live bird markets, as well as the presence of many areas where wild and domestic birds co-exist, make California susceptible to avian influenza outbreaks. The 2014-2015 highly pathogenic Avian Influenza (HPAI outbreaks affecting California and other states in the United States have underscored the need for solutions to protect the US poultry industry against this devastating disease. We applied disease distribution models to predict where Avian influenza is likely to occur and the risk for HPAI outbreaks is highest. We used observations on the presence of Low Pathogenic Avian influenza virus (LPAI in waterfowl or water samples at 355 locations throughout the state and environmental variables relevant to the disease epidemiology. We used two algorithms, Random Forest and MaxEnt, and two data-sets Presence-Background and Presence-Absence data. The models performed well (AUCc > 0.7 for testing data, particularly those using Presence-Background data (AUCc > 0.85. Spatial predictions were similar between algorithms, but there were large differences between the predictions with Presence-Absence and Presence-Background data. Overall, predictors that contributed most to the models included land cover, distance to coast, and broiler farm density. Models successfully identified several counties as high-to-intermediate risk out of the 8 counties with observed outbreaks during the 2014-2015 HPAI epizootics. This study provides further insights into the spatial epidemiology of AI in California, and the high spatial resolution maps may be useful to guide risk-based surveillance and outreach efforts.

Simulation of high consequence areas for gas pipelines

Directory of Open Access Journals (Sweden)

Orlando Díaz-Parra

2018-01-01

Full Text Available The gas pipeline is used for the transport of natural gas at a great distance. Risks derived from the handling of a combustible material transported under high pressure, by pipelines that pass close to where people live, makes it necessary to adopt prevention, mitigation and control measures to reduce the effect in case of ignition of a gas leak. This work shows the development of a new mathematical model to determine areas of high consequence and their application, using widely available and easy to use software, such as Google Earth and Excel, to determine and visualize the area up to which the level of radiation can affect the integrity of people and buildings. The model takes into account the pressure drop into the gas pipeline from the compression station, the gas leakage rate and possible forms of gas ignition. This development is an alternative to the use of specialized software and highly trained personnel. The simulation is applied to a traced of the Miraflores-Tunja gas pipeline, using a macro developed in Excel to determine the impact area and compare it with the coordinates of the vulnerable areas. The zones where these areas intersect are constituted in high consequence areas and are identified along with the sections of the pipeline that affect them, to provide the operator with a risk analysis tool for the determination and visualization of the gas pipeline and its environment.

Statistical removal of background signals from high-throughput 1H NMR line-broadening ligand-affinity screens

International Nuclear Information System (INIS)

Worley, Bradley; Sisco, Nicholas J.; Powers, Robert

2015-01-01

NMR ligand-affinity screens are vital to drug discovery, are routinely used to screen fragment-based libraries, and used to verify chemical leads from high-throughput assays and virtual screens. NMR ligand-affinity screens are also a highly informative first step towards identifying functional epitopes of unknown proteins, as well as elucidating the biochemical functions of protein–ligand interaction at their binding interfaces. While simple one-dimensional 1 H NMR experiments are capable of indicating binding through a change in ligand line shape, they are plagued by broad, ill-defined background signals from protein 1 H resonances. We present an uncomplicated method for subtraction of protein background in high-throughput ligand-based affinity screens, and show that its performance is maximized when phase-scatter correction is applied prior to subtraction

High-surface-area active carbon

International Nuclear Information System (INIS)

O'Grady, T.M.; Wennerberg, A.N.

1986-01-01

This paper describes the preparation and properties of a unique active carbon having exceptionally high surface areas, over 2500 m 2 /gm, and extraordinary adsorptive capacities. The carbon is made by a direct chemical activation route in which petroleum coke or other carbonaceous sources are reacted with excess potassium hydroxide at 400 0 to 500 0 C to an intermediate product that is subsequently pyrolyzed at 800 0 to 900 0 C to active carbon containing potassium salts. These are removed by water washing and the carbon is dried to produce a powdered product. A granular carbon can also be made by further processing the powdered carbon by using specialized granulation techniques. Typical properties of the carbon include Iodine Numbers of 3000 to 3600, methylene blue adsorption of 650 to 750 mg/gm, pore volumes of 2.0 to 2.6 cc/gm and less than 3.0% ash. This carbon's high adsorption capacities make it uniquely suited for numerous demanding applications in the medical area, purifications, removal of toxic substances, as catalyst carriers, etc

In vivo measurement of uranium in the human chest under high background conditions

International Nuclear Information System (INIS)

Kruger, P.J.; Feather, J.I.

1981-08-01

The use of a low-background counting room was considered essential for in vivo gamma counting of uranium in the human chest. When such measurements were, however, carried out under relatively high background conditions, this necessitated a new method of analysis. It was found that a linear relationship between LnN and E exists for each individual where N is the count rate per keV and E the energy in keV, for gamma energies between 90 keV and 300 keV. The displacements from this straight line at the energy values of 90 and 186 keV then represent the contribution of the uranium present. These displacements were calibrated for natural uranium. It was possible to detect contamination levels of lower than half MPLB [af

Neutron detection in a high gamma-ray background with EJ-301 and EJ-309 liquid scintillators

International Nuclear Information System (INIS)

Stevanato, L.; Cester, D.; Nebbia, G.; Viesti, G.

2012-01-01

Using a fast digitizer, the neutron–gamma discrimination capability of the new liquid scintillator EJ-309 is compared with that obtained using standard EJ-301. Moreover the capability of both the scintillation detectors to identify a weak neutron source in a high gamma-ray background is demonstrated. The probability of neutron detection is PD=95% at 95% confidence level for a gamma-ray background corresponding to a dose rate of 100 μSv/h.

High repetition rate laser-driven MeV ion acceleration at variable background pressures

Science.gov (United States)

Snyder, Joseph; Ngirmang, Gregory; Orban, Chris; Feister, Scott; Morrison, John; Frische, Kyle; Chowdhury, Enam; Roquemore, W. M.

2017-10-01

Ultra-intense laser-plasma interactions (LPI) can produce highly energetic photons, electrons, and ions with numerous potential real-world applications. Many of these applications will require repeatable, high repetition targets that are suitable for LPI experiments. Liquid targets can meet many of these needs, but they typically require higher chamber pressure than is used for many low repetition rate experiments. The effect of background pressure on the LPI has not been thoroughly studied. With this in mind, the Extreme Light group at the Air Force Research Lab has carried out MeV ion and electron acceleration experiments at kHz repetition rate with background pressures ranging from 30 mTorr to >1 Torr using a submicron ethylene glycol liquid sheet target. We present these results and provide two-dimensional particle-in-cell simulation results that offer insight on the thresholds for the efficient acceleration of electrons and ions. This research is supported by the Air Force Office of Scientific Research under LRIR Project 17RQCOR504 under the management of Dr. Riq Parra and Dr. Jean-Luc Cambier. Support was also provided by the DOD HPCMP Internship Program.

Canonical differential geometry of string backgrounds

International Nuclear Information System (INIS)

Schuller, Frederic P.; Wohlfarth, Mattias N.R.

2006-01-01

String backgrounds and D-branes do not possess the structure of Lorentzian manifolds, but that of manifolds with area metric. Area metric geometry is a true generalization of metric geometry, which in particular may accommodate a B-field. While an area metric does not determine a connection, we identify the appropriate differential geometric structure which is of relevance for the minimal surface equation in such a generalized geometry. In particular the notion of a derivative action of areas on areas emerges naturally. Area metric geometry provides new tools in differential geometry, which promise to play a role in the description of gravitational dynamics on D-branes

On the contribution of active galactic nuclei to the high-redshift metagalactic ionizing background

Science.gov (United States)

D'Aloisio, Anson; Upton Sanderbeck, Phoebe R.; McQuinn, Matthew; Trac, Hy; Shapiro, Paul R.

2017-07-01

Motivated by the claimed detection of a large population of faint active galactic nuclei (AGNs) at high redshift, recent studies have proposed models in which AGNs contribute significantly to the z > 4 H I ionizing background. In some models, AGNs are even the chief sources of reionization. If proved true, these models would make necessary a complete revision to the standard view that galaxies dominated the high-redshift ionizing background. It has been suggested that AGN-dominated models can better account for two recent observations that appear to be in conflict with the standard view: (1) large opacity variations in the z ˜ 5.5 H I Ly α forest, and (2) slow evolution in the mean opacity of the He II Ly α forest. Large spatial fluctuations in the ionizing background from the brightness and rarity of AGNs may account for the former, while the earlier onset of He II reionization in these models may account for the latter. Here we show that models in which AGN emissions source ≳50 per cent of the ionizing background generally provide a better fit to the observed H I Ly α forest opacity variations compared to standard galaxy-dominated models. However, we argue that these AGN-dominated models are in tension with constraints on the thermal history of the intergalactic medium (IGM). Under standard assumptions about the spectra of AGNs, we show that the earlier onset of He II reionization heats up the IGM well above recent temperature measurements. We further argue that the slower evolution of the mean opacity of the He II Ly α forest relative to simulations may reflect deficiencies in current simulations rather than favour AGN-dominated models as has been suggested.

Aerosol optical properties at rural background area in Western Saudi Arabia

Science.gov (United States)

Lihavainen, H.; Alghamdi, M. A.; Hyvärinen, A.; Hussein, T.; Neitola, K.; Khoder, M.; Abdelmaksoud, A. S.; Al-Jeelani, H.; Shabbaj, I. I.; Almehmadi, F. M.

2017-11-01

To derive the comprehensive aerosol in situ characteristics at a rural background area in Saudi Arabia, an aerosol measurements station was established to Hada Al Sham, 60 km east from the Red Sea and the city of Jeddah. The present sturdy describes the observational data from February 2013 to February 2015 of scattering and absorption coefficients, Ångström exponents and single scattering albedo over the measurement period. The average scattering and absorption coefficients at wavelength 525 nm were 109 ± 71 Mm- 1 (mean ± SD, at STP conditions) and 15 ± 17 Mm- 1 (at STP conditions), respectively. As expected, the scattering coefficient was dominated by large desert dust particles with low Ångström scattering exponent, 0.49 ± 0.62. Especially from February to June the Ångström scattering exponent was clearly lower (0.23) and scattering coefficients higher (124 Mm- 1) than total averages because of the dust outbreak season. Aerosol optical properties had clear diurnal cycle. The lowest scattering and absorption coefficients and aerosol optical depths were observed around noon. The observed diurnal variation is caused by wind direction and speed, during night time very calm easterly winds are dominating whereas during daytime the stronger westerly winds are dominating (sea breeze). Positive Matrix Factorization mathematical tool was applied to the scattering and absorption coefficients and PM2.5 and coarse mode (PM10-PM2.5) mass concentrations to identify source characteristics. Three different factors with clearly different properties were found; anthropogenic, BC source and desert dust. Mass absorption efficiencies for BC source and desert dust factors were, 6.0 m2 g- 1 and 0.4 m2 g- 1, respectively, and mass scattering efficiencies for anthropogenic (sulphate) and desert dust, 2.5 m2 g- 1 and 0.8 m2 g- 1, respectively.

Areas with increased natural radioactivity. Pt. 7

International Nuclear Information System (INIS)

Soman, S.D.; Nambi, K.S.V.

1990-03-01

When studying possible health effects of environmental radioactivity to man, areas of high natural radiation background are especially valuable. The classical and most investigated areas with this respect in the world are the monazite sand regions on the beaches of the States of Kerala and Tamil Nadu in South-India. Indian scientists from the Bhabha Atomic Research Center (BARC) have investigated possible health effects to man by the high natural background radiation in this area since about thirty years. As a remarkable result of the epidemiological studies, no significant genetical radiation damage effects within a collective of about seventythousand investigated persons could be observed. When studying lung cancer risks as a function of natural radiation exposure in the region of relatively low doses, the central problem is, how to extrapolate from the high doses of uranium miners to zero doses. Since the relative number of lung cancer is too small and does not exceed the statistical noise level, no significant experimental approval could be made until today. Therefore, one has to rely mainly on three different hypothesis, among which one cannot make an experimental decision at the moment. Hypothesis I (linear extrapolation) is the most pessimistic one, which denies the existence of repair mechanisms. Hypethesis II (threshold behaviour) is more realistic and considers repair mechanisms. Hypothesis III (hormesis effect) assumes positive health effects at lower radiation doses because of the proved existence of repair mechanisms in the living human cell and their stimulation by irradiation. In possible agreement with hypothesis III, within the last few years several authors in different areas of the world with higher natural radiation background have observed a significant decrease of lung cancer risk with increasing natural radiation background. The authors of this report are demonstrating this behaviour for India with their sets of data. (orig./MG)

Role of geochemical background at evaluation of investment attractiveness of recreational territories

Directory of Open Access Journals (Sweden)

Vdovina Ol'ga Konstantinovna

2014-09-01

Full Text Available The article shows the role of natural geochemical background when estimating investment attractiveness of recreational areas. It is noted, that geochemical background influence on people's sickness rate isn't considered now. Though it's understood, that even insignificant increase of geochemical background in relation to percentage abundance of Earth crest may lead to endemic diseases of people, animals and plants. An indicator of geochemical endemicity areas was proposed for assessing the impact of storage elements and of a lack of geological environment on human health. Thanks to this measure, and taking into account landscape features of the area, the authors allocated lands, dangerous and potentially dangerous in terms of endemicity. The importance of ratings was achieved by the use of those factors that could have a great influence on the cost of land development. This includes, first of all, the factors that affect population health, and economic and geographic factors that minimize the cost of the territory development and the factors that give rise to financial risks and risks of human losses. The main risk factors include: potential ecological and geochemical risk; high absolute heights, development and activity of dangerous geological processes and phenomena. Systemacity of researches was reached by using factors, that characterize the object from different aspects; readiness of area infrastructure to its exploration and possible risks. Objectivity was achieved by the use of figures obtained from the results of geochemical and engineering surveys with their metrological support.

ON THE EFFECT OF THE COSMIC MICROWAVE BACKGROUND IN HIGH-REDSHIFT (SUB-)MILLIMETER OBSERVATIONS

Energy Technology Data Exchange (ETDEWEB)

Da Cunha, Elisabete; Groves, Brent; Walter, Fabian; Decarli, Roberto; Rix, Hans-Walter [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Weiss, Axel [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); Bertoldi, Frank [Argelander Institute for Astronomy, University of Bonn, Auf dem Huegel 71, D-53121 Bonn (Germany); Carilli, Chris [National Radio Astronomy Observatory, Pete V. Domenici Array Science Center, P.O. Box O, Socorro, NM 87801 (United States); Daddi, Emanuele; Sargent, Mark [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, Irfu/Service d' Astrophysique, CEA Saclay, Orme des Merisiers, F-91191 Gif-sur-Yvette Cedex (France); Elbaz, David; Ivison, Rob [UK Astronomy Technology Centre, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Maiolino, Roberto [Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge, CB3 0HE (United Kingdom); Riechers, Dominik [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Smail, Ian, E-mail: cunha@mpia.de [Institute for Computational Cosmology, Durham University, South Road, Durham DH1 3LE (United Kingdom)

2013-03-20

Modern (sub-)millimeter interferometers enable the measurement of the cool gas and dust emission of high-redshift galaxies (z > 5). However, at these redshifts the cosmic microwave background (CMB) temperature is higher, approaching, and even exceeding, the temperature of cold dust and molecular gas observed in the local universe. In this paper, we discuss the impact of the warmer CMB on (sub-)millimeter observations of high-redshift galaxies. The CMB affects the observed (sub-)millimeter dust continuum and the line emission (e.g., carbon monoxide, CO) in two ways: (1) it provides an additional source of (both dust and gas) heating and (2) it is a non-negligible background against which the line and continuum emission are measured. We show that these two competing processes affect the way we interpret the dust and gas properties of high-redshift galaxies using spectral energy distribution models. We quantify these effects and provide correction factors to compute what fraction of the intrinsic dust (and line) emission can be detected against the CMB as a function of frequency, redshift, and temperature. We discuss implications on the derived properties of high-redshift galaxies from (sub-)millimeter data. Specifically, the inferred dust and molecular gas masses can be severely underestimated for cold systems if the impact of the CMB is not properly taken into account.

High Surface Area Tunnels in Hexagonal WO₃.

Science.gov (United States)

Sun, Wanmei; Yeung, Michael T; Lech, Andrew T; Lin, Cheng-Wei; Lee, Chain; Li, Tianqi; Duan, Xiangfeng; Zhou, Jun; Kaner, Richard B

2015-07-08

High surface area in h-WO3 has been verified from the intracrystalline tunnels. This bottom-up approach differs from conventional templating-type methods. The 3.67 Å diameter tunnels are characterized by low-pressure CO2 adsorption isotherms with nonlocal density functional theory fitting, transmission electron microscopy, and thermal gravimetric analysis. These open and rigid tunnels absorb H(+) and Li(+), but not Na(+) in aqueous electrolytes without inducing a phase transformation, accessing both internal and external active sites. Moreover, these tunnel structures demonstrate high specific pseudocapacitance and good stability in an H2SO4 aqueous electrolyte. Thus, the high surface area created from 3.67 Å diameter tunnels in h-WO3 shows potential applications in electrochemical energy storage, selective ion transfer, and selective gas adsorption.

PM Levels, Composition and Evolution in a Highly Industrialised Area. Objectives of Improvement

Science.gov (United States)

Minguillon, M. C.; Querol, X.; Alastuey, A.; Monfort, E.; Mantilla, E.; Miro, J. V.

2007-05-01

Evolution of levels and speciation of PM10 in the ceramic producing area of Castello (East Spain) was studied from April 2002 until December 2005. To this end, daily PM10 sampling was carried out at three urban sites and one suburban site of the area and chemical analyses were made in about 35 % of the samples. Average PM10 levels varied between 27-36 µg/m3 for the study period. The major constituent was mineral matter, exceeding by 5-12 µg/m3 the usual ranges of annual mineral loads in PM10 at similar Spanish urban or regional background sites with no industrial influence. Based on this comparison and on the efficiency of emission abatement techniques, a reduction target of 3-5 µgPM10/m3 of the annual mean seems to be achievable at the urban sites. Moreover, levels of Li, Sc, Co, Zn, As, Se, Rb, Zr, Cd, Cs, Ce, Tl and Pb were higher than the usual range of concentration in urban areas of Spain. Of these elements, Zr, Zn, Pb and As may be considered as tracers of the ceramic emissions from the study area. Their levels showed a simultaneous decrease with the progressive implementation of emission abatement techniques in frit (glaze component for the manufacture of glazed tiles) fusion kilns of the area. Given the high proportion of facilities with implemented abatement techniques at the end of the study period, the reduction margin for these elements is very low.

49 CFR 195.452 - Pipeline integrity management in high consequence areas.

Science.gov (United States)

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Pipeline integrity management in high consequence... Management § 195.452 Pipeline integrity management in high consequence areas. (a) Which pipelines are covered... that could affect a high consequence area, including any pipeline located in a high consequence area...

Biological effects of high level natural background radiation on human population residing in Kerala coast, South West India

International Nuclear Information System (INIS)

Seshadri, M.

2010-01-01

The populations residing in Kerala coast are exposed to elevated natural background radiation since many generations. Extensive studies conducted by Bio-Medical group, Bhabha Atomic Research Center have generated wealth of data from this area dealing with epidemiology, monitoring the newborns for malformations, Health Audit Survey, Dosimetry and biological studies using cytogenetic and molecular biology techniques. Our studies on congenital malformations and chromosomal anomalies in children born to parents residing in High Level Natural Radiation Areas in Kerala have not shown any significant difference from normal radiation areas. Screening of over 1,25,000 consecutively born children showed an incidence rate which is comparable in both areas. Other factors such as consanguinity, maternal age and gravida status are more significant contributors than radiation dose to the risk for having malformation in child. Radiation prevalent in the HLNRA is in the dose range of above 1.5 to about 50 mGy per year which translates to doses in the range of nGy per hour. This clearly indicate the number of cells exposed to radiations will be one in few thousand or ten thousands. This throws up challenges in our capability to investigate the effects of radiation on cells. It has become imperative to develop and exploit techniques which will detect responses in single cells and would be able screen large number of cells at a time. Developments in cell biology and molecular biology are now giving us these capabilities. Use of flowcytometer and next generation sequencing would enable us to address many of these questions and provide meaningful approaches to understand the effects of such low dose radiation

Background studies of high energy γ rays from (n,γ) reactions in the CANDLES experiment

Science.gov (United States)

Nakajima, K.; Iida, T.; Akutagawa, K.; Batpurev, T.; Chan, W. M.; Dokaku, F.; Fushimi, K.; Kakubata, H.; Kanagawa, K.; Katagiri, S.; Kawasaki, K.; Khai, B. T.; Kino, H.; Kinoshita, E.; Kishimoto, T.; Hazama, R.; Hiraoka, H.; Hiyama, T.; Ishikawa, M.; Li, X.; Maeda, T.; Matsuoka, K.; Moser, M.; Nomachi, M.; Ogawa, I.; Ohata, T.; Sato, H.; Shamoto, K.; Shimada, M.; Shokati, M.; Takahashi, N.; Takemoto, Y.; Takihira, Y.; Tamagawa, Y.; Tozawa, M.; Teranishi, K.; Tetsuno, K.; Trang, V. T. T.; Tsuzuki, M.; Umehara, S.; Wang, W.; Yoshida, S.; Yotsunaga, N.

2018-07-01

High energy γ rays with several MeV produced by (n,γ) reactions can be a trouble for low background measurements in the underground laboratories such as double beta decay experiments. In the CANDLES project, which aimed to observe the neutrino-less double beta decay from 48Ca, γ rays caused by (n,γ) reactions were found to be the most significant background. The profile of the background was studied by measurements with a neutron source and a simulation with a validity check of neutron processes in Geant4. The observed spectrum of γ rays from (n,γ) reactions was well reproduced by the simulated spectra, which were originated from the surrounding rock and a detector tank made of stainless steel. The environmental neutron flux was derived by the observed event rate of γ rays from (n,γ) reactions using the simulation. The thermal and non-thermal neutron flux were found to be (1.3 ± 0.6) ×10-6 cm-2s-1 and (1.1 ± 0.5) ×10-5 cm-2s-1 , respectively. It is necessary to install an additional shield to reduce the background from (n,γ) reaction to the required level.

Background current of radioisotope manometer

International Nuclear Information System (INIS)

Vydrik, A.A.

1987-01-01

The technique for calculating the main component of the background current of radioisotopic monometers, current from direct collision of ionizing particles and a collector, is described. The reasons for appearance of background photoelectron current are clarified. The most effective way of eliminating background current components is collector protection from the source by a screen made of material with a high gamma-quanta absorption coefficient, such as lead, for example

Recruiting and retaining high-quality teachers in rural areas.

Science.gov (United States)

Monk, David H

2007-01-01

In examining recruitment and retention of teachers in rural areas, David Monk begins by noting the numerous possible characteristics of rural communities--small size, sparse settlement, distance from population concentrations, and an economic reliance on agricultural industries that are increasingly using seasonal and immigrant workers to minimize labor costs. Many, though not all, rural areas, he says, are seriously impoverished. Classes in rural schools are relatively small, and teachers tend to report satisfaction with their work environments and relatively few problems with discipline. But teacher turnover is often high, and hiring can be difficult. Monk observes that rural schools have a below-average share of highly trained teachers. Compensation in rural schools tends to be low, perhaps because of a lower fiscal capacity in rural areas, thus complicating efforts to attract and retain teachers. Several student characteristics, including relatively large shares of students with special needs and with limited English skills and lower shares of students attending college, can also make it difficult to recruit and retain high-quality teachers. Other challenges include meeting the needs of highly mobile children of low-income migrant farm workers. With respect to public policy, Monk asserts a need to focus on a subcategory of what might be called hard-to-staff rural schools rather than to develop a blanket set of policies for all rural schools. In particular, he recommends a focus on such indicators as low teacher qualifications, teaching in fields far removed from the area of training, difficulty in hiring, high turnover, a lack of diversity among teachers in the school, and the presence of migrant farm workers' children. Successful efforts to stimulate economic growth in these areas would be highly beneficial. He also calls attention to the potential for modern telecommunication and computing technologies to offset some of the drawbacks associated with teaching

Tritium Concentrations in Environmental Samples and Transpiration Rates from the Vicinity of Mary's Branch Creek and Background Areas, Barnwell, South Carolina, 2007-2009

Science.gov (United States)

Vroblesky, Don A.; Canova, Judy L.; Bradley, Paul M.; Landmeyer, James E.

2009-01-01

Tritium in groundwater from a low-level radioactive waste disposal facility near Barnwell, South Carolina, is discharging to Mary's Branch Creek. The U.S. Geological Survey conducted an investigation from 2007 to 2009 to examine the tritium concentration in trees and air samples near the creek and in background areas, in groundwater near the creek, and in surface water from the creek. Tritium was found in trees near the creek, but not in trees from background areas or from sites unlikely to be in direct root contact with tritium-contaminated groundwater. Tritium was found in groundwater near the creek and in the surface water of the creek. Analysis of tree material has the potential to be a useful tool in locating shallow tritium-contaminated groundwater. A tritium concentration of 1.4 million picocuries per liter was measured in shallow groundwater collected near a tulip poplar located in an area of tritium-contaminated groundwater discharge. Evapotranspiration rates from the tree and tritium concentrations in water extracted from tree cores indicate that during the summer, this tulip poplar may remove more than 17.1 million picocuries of tritium per day from the groundwater that otherwise would discharge to Mary's Branch Creek. Analysis of air samples near the tree showed no evidence that the transpirative release of tritium to the air created a vapor hazard in the forest.

Variation of radon concentration in soil with different depth along the high background areas in Kerala

International Nuclear Information System (INIS)

Sonia, S.R.; Visnu Prasad, A.K.; Jojo, P.J.; Midhun, M.

2016-01-01

Radon is one of the naturally occurring radioactive gases in the environment produced from decay of radium isotopes, which are the decay product of 238 U, 232 Th and 235 U. Hence the concentration of uranium and thorium in the bed rock and soil materials determine the amount of radon produced in the soil. The radon produced in the soil migrates through the mechanism of diffusion and convection through pore spaces in the soil, fractures in the rock and along with weak zones such as shear faults, thrust etc. For some geological situations, radon migrates long distances from its place of origin and can be detected by alpha-particle recorders at the earth's surface. Concentration of radon in an area is governed by the radium content in the minerals, radon emanating power in the material, permeability of the soils and underlying rock, and moisture content in the soil

Background gamma radiation monitoring of three clusters of villages surrounding Mohuldih, Banduhurang and Bagjata villages, the proposed uranium mining areas in Singhbhum, Jharkhand

International Nuclear Information System (INIS)

Chougaonkar, M.P.; Puranik, V.D.; Singh, Prashant

2008-01-01

Generation of power is a fundamental catalyst to the social and economic development of a country. India needs more power in order to have a strong industrial base and for infrastructure development. With this in view, there has been an emphasis on nuclear power as an alternative source in the field of electricity generation as the nuclear power can be an effective tool in reducing stress on the environment. The Singhbhum district in the state of Jharkhand in India has been known to have deposits of uranium and uranium mines like Jaduguda, Narwapahar, Bhatin etc have been operating in the region. With the increased requirement of electricity and hence suitable fuel, few more sites are proposed to mine uranium in the region. The sites proposed are near the villages of Mohuldih, Banduhurang and Bagjata and are proposed to be open cast mines. These areas of Singhbhum are not economically advanced areas. By and large, the population is poor and there are existing problems like malnutrition and poor health. The activities of mining and the associated developments in the region are expected to improve the economic condition of the residents either through direct employment in the mining facilities, or by indirect gains due to infrastructural developments in the region. In order to assess the impact of the mining operations on the environment and the population as well, it is necessary that the pre-operational survey be carried out in the regions in question. As is the practice, a complete pre-operational survey of the physical, chemical and environmental parameters has been carried out in the region. Background gamma radiation survey was also carried out, using the thermo luminescent dosimetry technique, to obtain the preoperational levels prevalent in the regions. This paper gives the results of the baseline background gamma radiation survey in the region. It was observed that the general gamma background levels of the areas, as measured using TLDs, was 1.36 ± 0.41 m

More Efficient e-Learning through Design: Color of Text and Background

Science.gov (United States)

Zufic, Janko; Kalpic, Damir

2009-01-01

Background: The area of research aimed for a more efficient e-learning is slowly widening from purely technical to the areas of psychology, didactics and methodology. The question is whether the text or background color influence the efficiency of memory, i.e. learning. If the answer to that question is positive, then another question arises which…

Active commuting of the inhabitants of Liberec city in low and high walkability areas

Directory of Open Access Journals (Sweden)

Lukáš Rubín

2015-12-01

Full Text Available Background: Active commuting in terms of everyday transport to school or work can have a significant effect on physical activity. Active commuting can be influenced by the environment, and examples from abroad show that current environmental changes tend mostly to promote passive forms of commuting. A similar situation of decreasing active commuting might be expected in the Czech Republic. However, little information has been published to date about the issue of active commuting among the inhabitants of our country. Objective: The main objective of the present study is to describe the active commuting patterns of the inhabitants of Liberec city in low and high walkability areas. Methods: A total of 23,621 economically active inhabitants or students of Liberec city aged 6-87 years (34.77 ± 14.39 participated in the study. The data about commuting were retrieved from the national Population and Housing Census of 2011. Geographic information systems were used to objectively analyze the built environment and to calculate the walkability index. Results: Active commuting to/from school or work is used by 17.41% of inhabitants. Active commuting is dominated by walking (16.60% as opposed to cycling (0.81%. Inhabitants who lived in high walkability areas were more likely to actively commute than those living in low walkability areas (OR = 1.54; 95% CI [1.41, 1.68]. Conclusions: This study confirmed the findings of international studies about the effect of the built environment on active commuting among Liberec inhabitants. Active commuters are often those living near or in the city center, which is characterized by high walkability. In Liberec city, walking as a means of active commuting significantly prevails over cycling. One of the reasons might be the diverse topography of the city and the insufficiently developed cycling network.

Description of background data in the SKB database GEOTAB

International Nuclear Information System (INIS)

Eriksson, E.; Sehlstedt, S.

1989-02-01

During the research and development program performed by SKB for the final disposal of spent nuclear fuel, a large quantity of geoscientific data was collected. Most of this data was stored in a database called GEOTAB. This report describes data within the background data group. This data provides information on the location of areas studied, borehole positions and also some drilling information. The background data group (subject), called BGR, is divided into several subgroups (methods): BGAREA area background data; BGDRILL drilling information; BGDRILLP drill penetration data; BGHOLE borehole information; BGTABLES number of rows in a table, and BGTOLR data table tolerance. A method consists of one or several data tables. In each chapter a method and its data tables are described. (orig./HP)

High-Temperature-Short-Time Annealing Process for High-Performance Large-Area Perovskite Solar Cells.

Science.gov (United States)

Kim, Minjin; Kim, Gi-Hwan; Oh, Kyoung Suk; Jo, Yimhyun; Yoon, Hyun; Kim, Ka-Hyun; Lee, Heon; Kim, Jin Young; Kim, Dong Suk

2017-06-27

Organic-inorganic hybrid metal halide perovskite solar cells (PSCs) are attracting tremendous research interest due to their high solar-to-electric power conversion efficiency with a high possibility of cost-effective fabrication and certified power conversion efficiency now exceeding 22%. Although many effective methods for their application have been developed over the past decade, their practical transition to large-size devices has been restricted by difficulties in achieving high performance. Here we report on the development of a simple and cost-effective production method with high-temperature and short-time annealing processing to obtain uniform, smooth, and large-size grain domains of perovskite films over large areas. With high-temperature short-time annealing at 400 °C for 4 s, the perovskite film with an average domain size of 1 μm was obtained, which resulted in fast solvent evaporation. Solar cells fabricated using this processing technique had a maximum power conversion efficiency exceeding 20% over a 0.1 cm 2 active area and 18% over a 1 cm 2 active area. We believe our approach will enable the realization of highly efficient large-area PCSs for practical development with a very simple and short-time procedure. This simple method should lead the field toward the fabrication of uniform large-scale perovskite films, which are necessary for the production of high-efficiency solar cells that may also be applicable to several other material systems for more widespread practical deployment.

Natural radionuclide and radiological assessment of building materials in high background radiation areas of Ramsar, Iran.

Science.gov (United States)

Bavarnegin, Elham; Moghaddam, Masoud Vahabi; Fathabadi, Nasrin

2013-04-01

Building materials, collected from different sites in Ramsar, a northern coastal city in Iran, were analyzed for their natural radionuclide contents. The measurements were carried out using a high resolution high purity Germanium (HPGe) gamma-ray spectrometer system. The activity concentration of (226)Ra, (232)Th, and (40)K content varied from below the minimum detection limit up to 86,400 Bqkg(-1), 187 Bqkg(-1), and 1350 Bqkg(-1), respectively. The radiological hazards incurred from the use of these building materials were estimated through various radiation hazard indices. The result of this survey shows that values obtained for some samples are more than the internationally accepted maximum limits and as such, the use of them as a building material pose significant radiation hazard to individuals.

Diffuse Cosmic Infrared Background Radiation

Science.gov (United States)

Dwek, Eli

2002-01-01

The diffuse cosmic infrared background (CIB) consists of the cumulative radiant energy released in the processes of structure formation that have occurred since the decoupling of matter and radiation following the Big Bang. In this lecture I will review the observational data that provided the first detections and limits on the CIB, and the theoretical studies explaining the origin of this background. Finally, I will also discuss the relevance of this background to the universe as seen in high energy gamma-rays.

Analytical expression for the phantom generated bremsstrahlung background in high energy electron beams

International Nuclear Information System (INIS)

Sorcini, B.B.; Hyoedynmaa, S; Brahme, A.

1995-01-01

Qualification of the bremsstrahlung photon background generated by an electron beam in a phantom is important for accurate high energy electron beam dosimetry in radiation therapy. An analytical expression has been derived for the background of phantom generated bremsstrahlung photons in plane parallel electron beams normally incident on phantoms of any atomic number between 4 and 92 (Be, C, H 2 O, Al, Cu, Ag, Pb and U). The expression can be used with fairly good accuracy in the energy range between 1 and 50 MeV. The expression is globally based on known scattering power and radiation and collision stopping power data for the phantom material at the mean energy of the incident electrons. The depth dose distribution due to the bremsstrahlung generated in the phantom is derived by folding the bremsstrahlung energy fluence with a simple analytical one-dimensional photon energy deposition kernel. The energy loss of the primary electrons and the generation, attenuation and absorption of bremsstrahlung photons are taken into account in the analytical formula. The photon energy deposition kernel is used to account for the bremsstrahlung produced at one depth that will contribute to the down stream dose. A simple analytical expression for photon energy deposition kernel is consistent with the classical analytical relation describing the photon depth dose distribution. From the surface to the practical range the photon dose increases almost linearly due to accumulation and buildup of the photon produced at different phantom layers. At depths beyond the practical range a simple exponential function can be use to describe the bremsstrahlung attenuation in the phantom. For comparison Monte Carlo calculated distributions using ITS3 Monte Carlo Code were used. Good agreement is found between the analytical expression and Monte Carlo calculation. Deviations of 5% from Monte Carlo calculated bremmstrahlung background are observed for high atomic number materials. The method can

Large-area high-efficiency flexible PHOLED lighting panels

Science.gov (United States)

Pang, Huiqing; Mandlik, Prashant; Levermore, Peter A.; Silvernail, Jeff; Ma, Ruiqing; Brown, Julie J.

2012-09-01

Organic Light Emitting Diodes (OLEDs) provide various attractive features for next generation illumination systems, including high efficiency, low power, thin and flexible form factor. In this work, we incorporated phosphorescent emitters and demonstrated highly efficient white phosphorescent OLED (PHOLED) devices on flexible plastic substrates. The 0.94 cm2 small-area device has total thickness of approximately 0.25 mm and achieved 63 lm/W at 1,000 cd/m2 with CRI = 85 and CCT = 2920 K. We further designed and fabricated a 15 cm x 15 cm large-area flexible white OLED lighting panels, finished with a hybrid single-layer ultra-low permeability single layer barrier (SLB) encapsulation film. The flexible panel has an active area of 116.4 cm2, and achieved a power efficacy of 47 lm/W at 1,000 cd/m2 with CRI = 83 and CCT = 3470 K. The efficacy of the panel at 3,000 cd/m2 is 43 lm/W. The large-area flexible PHOLED lighting panel is to bring out enormous possibilities to the future general lighting applications.

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...

Dry deposition of sulphur at a high-altitude background station in South Africa

CSIR Research Space (South Africa)

Zunckel, M

1999-10-01

Full Text Available station also plays a role in the observed day-to-day variation as pollutants are trapped immediately below this layer. The pressure difference between the base of the absolutely stable layer and the surface pressure at Ben MacDhui is used to indicate... AT A HIGH-ALTITUDE BACKGROUND STATION IN SOUTH AFRICA MARK ZUNCKEL1;2 , STUART PIKETH1 and TALI FREIMAN1 1 Climatology Research Group, University of Witwatersrand, Johannesburg, South Africa; 2 CSIR Environmentek, P.O. Box 17001, Congella, South Africa...

PM sources in a highly industrialised area in the process of implementing PM abatement technology. Quantification and evolution.

Science.gov (United States)

Cruz Minguillón, María; Querol, Xavier; Alastuey, Andrés; Monfort, Eliseo; Vicente Miró, José

2007-10-01

Principal component analysis (PCA) coupled with a multilinear regression analysis (MLRA) was applied to PM(10) speciation data series (2002-2005) from four sampling sites in a highly industrialised area (ceramic production) in the process of implementing emission abatement technology. Five common factors with similar chemical profiles were identified at all the sites: mineral, regional background (influenced by the industrial estate located on the coast: an oil refinery and a power plant), sea spray, industrial 1 (manufacture and use of glaze components, including frit fusion) and road traffic. The contribution of the regional background differs slightly from site to site. The mineral factor, attributed to the sum of several sources (mainly the ceramic industry, but also with minor contributions from soil resuspension and African dust outbreaks) contributes between 9 and 11 microg m(-3) at all the sites. Source industrial 1 entails an increase in PM(10) levels between 4 and 5 microg m(-3) at the urban sites and 2 microg m(-3) at the suburban background site. However, after 2004, this source contributed less than 2 microg m(-3) at most sites, whereas the remaining sources did not show an upward or downward trend along the study period. This gradual decrease in the contribution of source industrial 1 coincides with the implementation of PM abatement technology in the frit fusion kilns of the area. This relationship enables us to assess the efficiency of the implementation of environmental technologies in terms of their impact on air quality.

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

International Nuclear Information System (INIS)

Vijayakumar, B.; George, Thomas; Sundara Rajan, P.; Selvi, B.S.; Balamurugan, M.; Pandit, G.G.; Ravi, P.M.; Tripathi, R.M.

2014-01-01

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

Easy Leaf Area: Automated digital image analysis for rapid and accurate measurement of leaf area.

Science.gov (United States)

Easlon, Hsien Ming; Bloom, Arnold J

2014-07-01

Measurement of leaf areas from digital photographs has traditionally required significant user input unless backgrounds are carefully masked. Easy Leaf Area was developed to batch process hundreds of Arabidopsis rosette images in minutes, removing background artifacts and saving results to a spreadsheet-ready CSV file. • Easy Leaf Area uses the color ratios of each pixel to distinguish leaves and calibration areas from their background and compares leaf pixel counts to a red calibration area to eliminate the need for camera distance calculations or manual ruler scale measurement that other software methods typically require. Leaf areas estimated by this software from images taken with a camera phone were more accurate than ImageJ estimates from flatbed scanner images. • Easy Leaf Area provides an easy-to-use method for rapid measurement of leaf area and nondestructive estimation of canopy area from digital images.

Reflections on Developing Secondary Vocational Education in High-Poverty Areas

Science.gov (United States)

Liu, Jiang; Chen, Guofeng

2013-01-01

Developing vocational education is a necessity for the economic and social development of high-poverty areas in China. But vocational education in impoverished areas lacks social recognition and faces funding shortages, along with difficulties in recruiting students. Vocational high schools themselves also have shortcomings. This article considers…

Area-to-Area Poisson Kriging and Spatial Bayesian Analysis

Science.gov (United States)

Asmarian, Naeimehossadat; Jafari-Koshki, Tohid; Soleimani, Ali; Taghi Ayatollahi, Seyyed Mohammad

2016-10-01

Background: In many countries gastric cancer has the highest incidence among the gastrointestinal cancers and is the second most common cancer in Iran. The aim of this study was to identify and map high risk gastric cancer regions at the county-level in Iran. Methods: In this study we analyzed gastric cancer data for Iran in the years 2003-2010. Areato- area Poisson kriging and Besag, York and Mollie (BYM) spatial models were applied to smoothing the standardized incidence ratios of gastric cancer for the 373 counties surveyed in this study. The two methods were compared in term of accuracy and precision in identifying high risk regions. Result: The highest smoothed standardized incidence rate (SIR) according to area-to-area Poisson kriging was in Meshkinshahr county in Ardabil province in north-western Iran (2.4,SD=0.05), while the highest smoothed standardized incidence rate (SIR) according to the BYM model was in Ardabil, the capital of that province (2.9,SD=0.09). Conclusion: Both methods of mapping, ATA Poisson kriging and BYM, showed the gastric cancer incidence rate to be highest in north and north-west Iran. However, area-to-area Poisson kriging was more precise than the BYM model and required less smoothing. According to the results obtained, preventive measures and treatment programs should be focused on particular counties of Iran. Creative Commons Attribution License

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.

Monitoring of external background radiation level in Asa dam ...

African Journals Online (AJOL)

An external background ionizing radiation study has been carried out within the Asa Dam Industrial Layout of Ilorin in Kwara State. The study was carried out in 5 stations within the industrial area using two Digilert Nuclear Radiation Monitors. The study has revealed that the external background ionizing radiation is ...

Hawkes process model with a time-dependent background rate and its application to high-frequency financial data

Science.gov (United States)

Omi, Takahiro; Hirata, Yoshito; Aihara, Kazuyuki

2017-07-01

A Hawkes process model with a time-varying background rate is developed for analyzing the high-frequency financial data. In our model, the logarithm of the background rate is modeled by a linear model with a relatively large number of variable-width basis functions, and the parameters are estimated by a Bayesian method. Our model can capture not only the slow time variation, such as in the intraday seasonality, but also the rapid one, which follows a macroeconomic news announcement. By analyzing the tick data of the Nikkei 225 mini, we find that (i) our model is better fitted to the data than the Hawkes models with a constant background rate or a slowly varying background rate, which have been commonly used in the field of quantitative finance; (ii) the improvement in the goodness-of-fit to the data by our model is significant especially for sessions where considerable fluctuation of the background rate is present; and (iii) our model is statistically consistent with the data. The branching ratio, which quantifies the level of the endogeneity of markets, estimated by our model is 0.41, suggesting the relative importance of exogenous factors in the market dynamics. We also demonstrate that it is critically important to appropriately model the time-dependent background rate for the branching ratio estimation.

Hawkes process model with a time-dependent background rate and its application to high-frequency financial data.

Science.gov (United States)

Omi, Takahiro; Hirata, Yoshito; Aihara, Kazuyuki

2017-07-01

A Hawkes process model with a time-varying background rate is developed for analyzing the high-frequency financial data. In our model, the logarithm of the background rate is modeled by a linear model with a relatively large number of variable-width basis functions, and the parameters are estimated by a Bayesian method. Our model can capture not only the slow time variation, such as in the intraday seasonality, but also the rapid one, which follows a macroeconomic news announcement. By analyzing the tick data of the Nikkei 225 mini, we find that (i) our model is better fitted to the data than the Hawkes models with a constant background rate or a slowly varying background rate, which have been commonly used in the field of quantitative finance; (ii) the improvement in the goodness-of-fit to the data by our model is significant especially for sessions where considerable fluctuation of the background rate is present; and (iii) our model is statistically consistent with the data. The branching ratio, which quantifies the level of the endogeneity of markets, estimated by our model is 0.41, suggesting the relative importance of exogenous factors in the market dynamics. We also demonstrate that it is critically important to appropriately model the time-dependent background rate for the branching ratio estimation.

Background problem for a large solid angle, high sensitivity detector

International Nuclear Information System (INIS)

Chen, M.

1977-01-01

With extremely good vacuum (10 -11 to 10 -13 torr) and well controlled beams, the ISR has a good reputation for clean beam conditions and low background for most types of experiments. However, for a detector covering a large solid angle, measuring processes with small cross sections (approximately 10 -38 cm 2 ) there are serious background problems which took almost a year to solve. Since ISABELLE may have similar problems, a summary is given of experience at the ISR with the hope that some of the solutions can be installed in ISABELLE at an early stage

Research in high speed fiber optics local area networks

Science.gov (United States)

Tobagi, F. A.

1986-01-01

The design of high speed local area networks (HSLAN) for communication among distributed devices requires solving problems in three areas: the network medium and its topology, the medium access control, and the network interface. Considerable progress was already made in the first two areas. Accomplishments are divided into two groups according to their theoretical or experimental nature. A brief summary is given.

Using the IEC standard to describe low-background detectors -- What can you expect?

International Nuclear Information System (INIS)

Keyser, R.M.; Wagner, S.

1998-01-01

Many measurements for environmental levels of the radioactive content require that the gamma-ray detector be low background, that is, free of any radioactive content. This is, of course, not possible, but the radioactivity in the detector must be reduced to as low a value as possible. The description or specification of the background spectrum necessary to achieve the desired results is needed. The new International Electrotechnical Commission (IEC) standard for describing the background makes the specification of the background in a high-purity germanium (HPGe) detector simple, unambiguous, and related to how the detector will be used. Users and manufacturers will finally be speaking the same language on this subject. Because this standard extends the specification of the performance of an HPGe detector, there is little history available for comparison and thus no means of determining a good value. To develop a history, the background spectrum for 500 low-background HPGe ORTEC detectors were all counted in similar low-background shields. These detectors were in a variety of mechanical cryostat and endcap configurations. The continuum background is a function of energy and detector size/configuration. The peak area for the peak energies listed in the standard is a function of detector size and configuration. The results thus give practical guidance for obtaining the most appropriate low-background detector for a specific measurement problem

Highly Flexible and High-Performance Complementary Inverters of Large-Area Transition Metal Dichalcogenide Monolayers

KAUST Repository

Pu, Jiang

2016-03-23

Complementary inverters constructed from large-area monolayers of WSe2 and MoS2 achieve excellent logic swings and yield an extremely high gain, large total noise margin, low power consumption, and good switching speed. Moreover, the WSe2 complementary-like inverters built on plastic substrates exhibit high mechanical stability. The results provide a path toward large-area flexible electronics. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experiences with nutrition-related information during antenatal care of pregnant women of different ethnic backgrounds residing in the area of Oslo, Norway.

Science.gov (United States)

Garnweidner, Lisa M; Sverre Pettersen, Kjell; Mosdøl, Annhild

2013-12-01

to explore experiences with nutrition-related information during routine antenatal care among women of different ethnical backgrounds. individual interviews with seventeen participants were conducted twice during pregnancy. Data collection and analysis were inspired by an interpretative phenomenological approach. participants were purposively recruited at eight Mother and Child Health Centres in the area of Oslo, Norway, where they received antenatal care. participants had either immigrant backgrounds from African and Asian countries (n=12) or were ethnic Norwegian (n=5). Participants were pregnant with their first child and had a pre-pregnancy Body Mass Index above 25 kg/m(2). participants experienced that they were provided with little nutrition-related information in antenatal care. The information was perceived as presented in very general terms and focused on food safety. Weight management and the long-term prevention of diet-related chronic diseases had hardly been discussed. Participants with immigrant backgrounds appeared to be confused about information given by the midwife which was incongruent with their original food culture. The participants were actively seeking for nutrition-related information and had to navigate between various sources of information. the midwife is considered a trustworthy source of nutrition-related information. Therefore, antenatal care may have considerable potential to promote a healthy diet to pregnant women. Findings suggest that nutrition communication in antenatal care should be more tailored towards women's dietary habits and cultural background, nutritional knowledge as well as level of nutrition literacy. Copyright © 2012 Elsevier Ltd. All rights reserved.

Health effects in residents of high background radiation regions

International Nuclear Information System (INIS)

Hanson, G.P.

1984-01-01

Although the health effects of radiation doses in occupationally exposed persons had received attention, it was not until the 1950s, when the atmospheric atom bomb tests of the United States and the Soviet Union had raised the level of environmental radioactivity, that the long-term effects of low-level radiation dosage became a matter of popular concern throughout the world. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) was created, and the World Health Organization (WHO) appointed an expert committee to provide advice concerning radiation and human health. In its first report, the WHO expert committee identified several areas of high natural radiation where studies of the exposed population might possibly provide information concerning the effects of chromic low-level radiation dosage

Background radiation in the Sydney metropolitan area scientific reality and public perception

International Nuclear Information System (INIS)

Kemeny, L.G.

1988-01-01

Very little information if any, is available to the public about the ubiquitous nature of low-level background radiation -both from terrestrial and cosmic sources - in our highly urbanised or predominantly agrarnian societies. Public perception has naively accepted that the combustion of precious oxygen by air breathing engines is both natural and societally acceptable. Little thought has been given to the fact that on the one planet known to be able to sustain life based on oxygen, this is a recipe for disaster. On the other hand, since the evolution or creation of our universe, billions of tonnes of radioactive material within the crust of planet earth together with radiation from the thermonuclear powers station of the solar system, the sun, have sustained life, assisted in its evolution and, through photosynthesis and energy deposition, have ensured its propagation. In this on-going student project, employing wide-band, sensitive scintillation radiation detectors, careful statistical analysis and an understanding of the physics of radium-uranium decay chain and the production of radon gas and its daughter products, fluctuation in the radiation fields of large cities is clearly demonstrated. The work is usually carried out by the author and his final year thesis and students have great educational value for the public, civic authorities, school teachers, the media and political decision makers

High-surface-area silica nanospheres (KCC-1) with a fibrous morphology

KAUST Repository

Polshettiwar, Vivek; Cha, Dong Kyu; Zhang, Xixiang; Basset, Jean-Marie

2010-01-01

Fibrous nanosilica: A new family of high-surface-area silica nanospheres (KCC-1) have been prepared (see picture). KCC-1 features excellent physical properties, including high surface area, unprecedented fibrous surface morphology, high thermal (up to 950 °C) and hydrothermal stabilities, and high mechanical stability. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High-surface-area silica nanospheres (KCC-1) with a fibrous morphology

KAUST Repository

Polshettiwar, Vivek

2010-08-02

Fibrous nanosilica: A new family of high-surface-area silica nanospheres (KCC-1) have been prepared (see picture). KCC-1 features excellent physical properties, including high surface area, unprecedented fibrous surface morphology, high thermal (up to 950 °C) and hydrothermal stabilities, and high mechanical stability. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High surface area fibrous silica nanoparticles

KAUST Repository

Polshettiwar, Vivek; Basset, Jean-Marie

2014-01-01

Disclosed are high surface area nanoparticles that have a fibrous morphology. The nanoparticles have a plurality of fibers, wherein each fiber is in contact with one other fiber and each fiber has a length of between about 1 nm and about 5000 nm. Also disclosed are applications of the nanoparticles of the present invention, and methods of fabrication of the nanoparticles of the present invention.

High surface area fibrous silica nanoparticles

KAUST Repository

Polshettiwar, Vivek

2014-11-11

Disclosed are high surface area nanoparticles that have a fibrous morphology. The nanoparticles have a plurality of fibers, wherein each fiber is in contact with one other fiber and each fiber has a length of between about 1 nm and about 5000 nm. Also disclosed are applications of the nanoparticles of the present invention, and methods of fabrication of the nanoparticles of the present invention.

Easy Leaf Area: Automated Digital Image Analysis for Rapid and Accurate Measurement of Leaf Area

Directory of Open Access Journals (Sweden)

Hsien Ming Easlon

2014-07-01

Full Text Available Premise of the study: Measurement of leaf areas from digital photographs has traditionally required significant user input unless backgrounds are carefully masked. Easy Leaf Area was developed to batch process hundreds of Arabidopsis rosette images in minutes, removing background artifacts and saving results to a spreadsheet-ready CSV file. Methods and Results: Easy Leaf Area uses the color ratios of each pixel to distinguish leaves and calibration areas from their background and compares leaf pixel counts to a red calibration area to eliminate the need for camera distance calculations or manual ruler scale measurement that other software methods typically require. Leaf areas estimated by this software from images taken with a camera phone were more accurate than ImageJ estimates from flatbed scanner images. Conclusions: Easy Leaf Area provides an easy-to-use method for rapid measurement of leaf area and nondestructive estimation of canopy area from digital images.

Fluctuations in radiation backgrounds at high redshift and the first stars

Science.gov (United States)

Holzbauer, Lauren Nicole

The first stars to light up our universe are as yet unseen, but there have been many attempts to elucidate their properties. The characteristics of these stars (`Population/Pop III' stars) that we do know lie mostly within theory; they formed out of metal-free hydrogen and helium gas contained in dark matter minihalos at redshifts z 20-30. The extent to which Pop III star formation reached into later times is unknown. Current and near future instruments are incapable of resolving individual Pop III stars. Consequently, astronomers must devise creative means with which to indirectly predict and measure and their properties. In this thesis, we will investigate a few of those means. We use a new method to model fluctuations of the Lyman-Werner (LW) and Lyman-alpha radiation backgrounds at high redshift. At these early epochs the backgrounds are symptoms of a universe newly lit with its first stars. LW photons (11.5-13.6 eV) are of particular interest because they dissociate molecular hydrogen, the primary coolant in the first minihalos that is necessary for star formation. By using a variation of the `halo model', which describes the spatial distribution and clustering of halos, we can efficiently generate power spectra for these backgrounds. Spatial fluctuations in the LW and (indirectly) the Lyman-alpha BG can tell us about the transition from primordial star formation to a more metal-enriched mode that marks the beginning of the second generation of stars in our Universe. The Near Infrared Background (NIRB) has for some time been considered a potential tool with which to indirectly observe the first stars. Ultraviolet (UV) emission from these stars is redshifted into the NIR band, making the NIRB amenable for hunting Pop III stellar signatures. There have been several measurements of the NIRB and subsequent theoretical studies attempting to explain them in recent years. Though controversial, residual levels of the mean NIRB intensity and anisotropies have been

Low energy background radiation in India

International Nuclear Information System (INIS)

Gopinath, D.V.

1980-01-01

Spectral distribution of background radiation at 9 locations spread all over India has been measured. Specifications of the counting set-up standardised for measurement are given. At one of the places, the background spectrum was measured with four different types of detectors. A broad peak in 60-100 keV with differing intensity and standard deviation is observed in all the spectra. In the Kalpakkam area, the peak near the seashore is observed to be more intense than away from the shore. This could be due to the presence of monazite sands on the seashore. The natural background radiation is observed to have a steep rise below 20 keV. Peak intensity is found to be independent of both the location (i.e. the source of energy) and the type of detector used for measurement. The calculated spectra due to multiple scattered radiation (with a nominal source energy of 1 MeV) through paraffin wax and the measured background spectrum with the detector shielded with 20 cm wax show good agreement above 40 keV. This shows that 80 keV hump in the natural background radiation is a property of air. The peak, therefore, in the spectra of natural background radiation is essentially a property of medium and it is independent of location or detector. (M.G.B.)

Determination of organically bound tritium background level in biological samples from a wide area in the south-west of France

International Nuclear Information System (INIS)

Pointurier, F.; Baglan, N.; Alanic, G.; Chiappini, R.

2003-01-01

In this paper, the authors describe a sensitive method for low-level non-exchangeable OBT determination. This methodology combines suitable sample treatment, a combustion apparatus for large-sized samples and low-background liquid scintillation spectrometry, along with precautions that substantially reduce the risks of sample contamination. Great care must be taken in the measurement of non-exchangeable OBT at environmental levels. Many authors have discussed the opportunities for cross-contamination between samples and contamination by exchange with the laboratory atmosphere. The authors also describe an application of the methodology to a large-scale sampling and measurement campaign, aimed at the determination of the environmental non-exchangeable OBT background level in tree leaves and ferns collected on the site and in the vicinity of a research centre located in the south-west of France, not far from Bordeaux. This study constitutes a 'zero level' for the non-exchangeable OBT activity, as, to our knowledge, there is no tritium source within or in the surroundings of the sampled area capable of producing non-exchangeable OBT activities above the natural levels. Our analyses showed that non-exchangeable OBT activities in the collected samples were very low, ranging from below the detection limit (ca 0.7 Bq kg -1 of dry material) to ca 2 Bq kg -1 of dry material. These values are similar to the natural tritium background measured in water samples. No discrepancies can be shown between fern samples and oak tree leaf samples or between samples collected inside and outside the research site

Determination of organically bound tritium background level in biological samples from a wide area in the south-west of France

Energy Technology Data Exchange (ETDEWEB)

Pointurier, F. E-mail: fabien.pointurier@cea.fr; Baglan, N.; Alanic, G.; Chiappini, R

2003-07-01

In this paper, the authors describe a sensitive method for low-level non-exchangeable OBT determination. This methodology combines suitable sample treatment, a combustion apparatus for large-sized samples and low-background liquid scintillation spectrometry, along with precautions that substantially reduce the risks of sample contamination. Great care must be taken in the measurement of non-exchangeable OBT at environmental levels. Many authors have discussed the opportunities for cross-contamination between samples and contamination by exchange with the laboratory atmosphere. The authors also describe an application of the methodology to a large-scale sampling and measurement campaign, aimed at the determination of the environmental non-exchangeable OBT background level in tree leaves and ferns collected on the site and in the vicinity of a research centre located in the south-west of France, not far from Bordeaux. This study constitutes a 'zero level' for the non-exchangeable OBT activity, as, to our knowledge, there is no tritium source within or in the surroundings of the sampled area capable of producing non-exchangeable OBT activities above the natural levels. Our analyses showed that non-exchangeable OBT activities in the collected samples were very low, ranging from below the detection limit (ca 0.7 Bq kg{sup -1} of dry material) to ca 2 Bq kg{sup -1} of dry material. These values are similar to the natural tritium background measured in water samples. No discrepancies can be shown between fern samples and oak tree leaf samples or between samples collected inside and outside the research site.

Simulation of Experimental Background using FLUKA

Energy Technology Data Exchange (ETDEWEB)

Rokni, Sayed

1999-05-11

In November 1997, Experiment T423 began acquiring data with the intentions of understanding the energy spectra of high-energy neutrons generated in the interaction of electrons with lead. The following describes a series of FLUKA simulations studying (1) particle yields in the absence of all background; (2) the background caused from scattering in the room; (3) the effects of the thick lead shielding which surrounded the detector; (4) the sources of neutron background created in this lead shielding; and (5) the ratio of the total background to the ideal yield. In each case, particular attention is paid to the neutron yield.

Geochemical background of zinc, cadmium and mercury in anthropically influenced soils in a semi-arid zone (SE, Spain)

Science.gov (United States)

García-Lorenzo, M. L.; Pérez-Sirvent, C.; Martínez-Sánchez, M. J.; Molina, J.; Tudela, M. L.; Hernández-Córdoba, M.

2009-04-01

This work seeks to establish the geochemical background for three potentially toxic trace elements (Zn, Cd and Hg) in a pilot zone included in the DesertNet project in the province of Murcia. The studied area, known as Campo de Cartagena, Murcia (SE Spain) is an area of intensive agriculture and has been much affected over the years by anthropic activity. The zone can be considered an experimental pilot zone for establishing background levels in agricultural soils. Sixty four samples were collected and corresponded to areas subjected to high and similar agricultural activity or soils with natural vegetation, which correspond to abandoned agricultural areas. The Zn content was determined by flame atomic absorption spectrometry. The Cd content was determined by electrothermal atomization atomic absorption spectrometry and mercury content was determined by atomic fluorescence spectrometry. Geostatistical analysis consisting of kriging and mapping was performed using the geostatistical analyst extension of ArcGIS 8.3. Zinc values ranged from 10 mg kg-1 to 151 mg kg-1, with an average value of 45 mg kg-1. Cadmium values ranged between 0.1 mg kg-1 and 0.9mg kg-1, with a mean value of 0.3 mg kg-1 and mercury values ranged from 0.1 mg kg-1 to 2.3 mg kg-1, with a mean value of 0.5 mg kg-1. At a national level, the Spanish Royal Decree 9/2005 proposes toxicological and statistical approaches to establish background values. According to the statistical approach, background values consist of the median value for the selected element. The background values for Zn, Cd and Hg in the studied area were 40 mg kg-1 for Zn, 0.3 mg kg-1 for Cd and 0.4 mg kg-1 for Hg.

Assessment of immune surveillance among inhabitants of high natural background radiation areas in Ramsar-Iran

International Nuclear Information System (INIS)

Sileh, Sajad Borzouei; Monfared, Ali Shabestani; Mostafazade, Amrollah; Abedian, Said

2010-01-01

In this study by Multi-parameter flow cytometry, immunologic analyze is performed on peripheral blood, NK cells, most effective cells in innate immune and the proportion of TCD8/TCD4 cells that is effective in cellular immune system will be determined. Lysosomal-associated membrane protein-1 (LAMP-1 or CD107a) is used as a functional marker for the identification of natural killer cell activity. Immune surveillance and immune system role in tumoral defense in Ramsar inhabitants will be determined. Radiation dose rate in Talesh mahalle is very high and was many times greater than Chaparsar (another region in Ramsar). Immune surveillance and immune system role in tumoral defense in Talesh mahalle inhabitants will be compared to Chaparsar inhabitants. If this doesn't have significant difference, we should think about some other aspects such as free radical scavengers that will study later

Incidence of neural tube defects in the natural radiation coastal areas of Kerala

International Nuclear Information System (INIS)

Jaikrishan, G.; Sudheer, K.R.; Andrews, V.J.; Koya, P.K.M.; Cheriyan, V.D.; Seshadri, M.

2010-01-01

All consecutive births in selected government hospitals in and around the high level natural background radiation areas (HLNRA) of Kerala were monitored for congenital malformations observable at birth since 1995. The HLNR area, a coastal strip of land about 55 km in length and 0.5 km in breadth from Purakkad in the north in Alleppey district to Sakthikulangara in the south of Quilon district, stands out among the most prominent background radiation areas of the world. Natural deposit of monazite sand, containing Thorium (8-10%), Uranium (0.3%) and corresponding decay products, is the source of elevated background radiation, ranging from < 1 to 45 mGy/year. Wide variation in dose, due to the patchy and non-uniform distribution of Monazite sand, enables in built controls. High population density, limited migration, ethnic diversity, good literacy, health awareness, institutionalized births and acceptance of small family norm are some of the key features of the population. Areas with a mean radiation dose of more than 1.5 mGy/year were treated as HLNR areas and areas with a dose level of 1.5 mGy/year or less were treated as normal level radiation (NLNR) areas. The study carried out since 1995 does not seem to implicate HLNR in the incidence of neural tube defects among newborns

High-capacity transport, floor area ratio and its relationship with urbanization of metropolitan areas

Energy Technology Data Exchange (ETDEWEB)

Carvalho da Costa, B.L. de; Carvalho da Costa, F.B. de

2016-07-01

Most of the world’s population lives in urban areas (54%). Near 42% of the global urban population live in cities with more than 1 million inhabitants, where problems associated with urban sprawl such as informal settlement, social-economic changes, environmental degradation and deficient high-capacity transport (HCT) systems are common. Meanwhile, urbanization and its associated transportation infrastructure define the relationship between city and countryside, between the city’s inner core and the periphery, between the citizen and his right to move. This article discusses and presents an overview about the relationship between the planning and extension of HCT systems and urban planning, (in the figure of the floor-area ratio - FAR- prescribed in regulations). The methodological approach consists of drawing a conceptual framework and studying 33 different cities of metropolitan areas on five continents. It’s noticed that areas in cities with a high construction potential but with an insufficient HCT negatively influence in urban mobility and hence the right to the city. We consider right to the city the various social and fundamental rights that, among others, includes the right to public transportation. Therefore there’s a real need of an integrated approach of community participation, FAR distribution, urban planning and transportation planning and so that urbanization, inevitable these days, takes place in a fair and harmonious way. (Author)

Anatomical distribution of peptic ulcer in high incidence gastric cancer area

Directory of Open Access Journals (Sweden)

Anuar Alonso Cedeño-Burbano

2014-12-01

Full Text Available Background: Peptic ulcer makes reference to the solution of continuity of gastric or duodenal wall beyond muscularis mucosae. Previously, duodenal location was more common than gastric, in a ratio ranging from 2:1 to 4:1. Despite this, after the discovery of the association between peptic ulcer and Helicobacter pylori, relationship between gastric and duodenal ulcer has spread to the equality. However, in areas with high incidence of gastric cancer, peptic ulcer seems to have a different behavior, existing predominance of gastric ulcer. Department of Cauca is have the highest incidence of gastric cancer in Colombia, with an annual rate of 42.5 /100,000 for males and 28.6 / 100,000 for women; however, it is unknown how peptic ulcer anatomically are distributed. Objective: To determine the anatomical distribution of peptic ulcer at endoscopy service of San José University Hospital of Popayán-Cauca, Colombia 2006-2012. Methods: A descriptive cross-sectional study was realized. Database of endoscopy service of San José University Hospital of Popayán was reviewed and reports with diagnosis of peptic ulcer were studied. Data were analyzed using SPSS-15. Results: Gastric ulcer was more common than duodenal ulcer. Gastric ulcer was more common in men (gastric and duodenal ulcer 1:1. In women duodenal ulcer is 1:1. Conclusion: At endoscopy service of San José University Hospital, gastric ulcer is more common than duodenal ulcer, with differences in gender, as in other areas with high incidence of gastric cancer. That fact are suggests in current literature could be related with the presence of stumps of Helicobacter pylori with combined virulence for cancer and ulcer at gastric level seems to be related to the presence in the medium of common virulence strains of Helicobacter pylori for stomach cancer and ulcer gastric, although the current literature is unclear about it, and still needs more validations.

A large-area grid ionisation chamber with high resolution for the measurement of alpha sources in samples with low specific activity

International Nuclear Information System (INIS)

Hoetzl, H.; Winkler, R.

1978-06-01

Construction and properties of a gridded ionization chamber for α-paricle spectrometry of low-level large-area samples are presented. Great importance was attached to high spectrometric resolution, low background, long-term stability, simple construction and operation, and easy decontamination if necessary. Using modern charge-sensitive preamplifiers spectrometric resolution is 20,6 keV FWHM (0,4%) at 5,30 MeV over the total effective area of 300 m 2 . Counting gas is an argon-methane mixture (P-10 gas) at atmospheric pressure. Background is 13 cph in the energy interval from 4 to 6 MeV and minimum detectable activity is 0.01 pCi Pu-239 at 1000 min measuring time. Ionization chambers of this type are used for direct α-spectrometric surveillance of long-lived α-emitting nuclides in the atmosphere after electrostatic deposition of the aerosols and for the determination of α-emitting nuclides in the emissions of nuclear power plants. After plasma ashing of the aerosols on filters from the stack monitoring system the minimum detectable concentration of e.g. Pu-239/240 in the gaseous effluent of a nuclear power plant is about 0.1 fCi per m 3 . (orig.) [de

Background compensation methodologies for contamination monitoring systems

International Nuclear Information System (INIS)

Raman, Anand; Chaudhury, Probal; Pradeepkumar, K.S.

2014-01-01

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/cdm 2 has been achieved in both these cases

A flat Universe from high-resolution maps of the cosmic microwave background radiation

Science.gov (United States)

de Bernardis P; Ade; Bock; Bond; Borrill; Boscaleri; Coble; Crill; De Gasperis G; Farese; Ferreira; Ganga; Giacometti; Hivon; Hristov; Iacoangeli; Jaffe; Lange; Martinis; Masi; Mason; Mauskopf; Melchiorri; Miglio; Montroy; Netterfield

2000-04-27

The blackbody radiation left over from the Big Bang has been transformed by the expansion of the Universe into the nearly isotropic 2.73 K cosmic microwave background. Tiny inhomogeneities in the early Universe left their imprint on the microwave background in the form of small anisotropies in its temperature. These anisotropies contain information about basic cosmological parameters, particularly the total energy density and curvature of the Universe. Here we report the first images of resolved structure in the microwave background anisotropies over a significant part of the sky. Maps at four frequencies clearly distinguish the microwave background from foreground emission. We compute the angular power spectrum of the microwave background, and find a peak at Legendre multipole Ipeak = (197 +/- 6), with an amplitude delta T200 = (69 +/- 8) microK. This is consistent with that expected for cold dark matter models in a flat (euclidean) Universe, as favoured by standard inflationary models.

High-level radioactive waste in Canada. Background paper

International Nuclear Information System (INIS)

Fawcett, R.

1993-11-01

The disposal of radioactive waste is one of the most challenging environmental problems facing Canada today. Since the Second World War, when Canadian scientists first started to investigate nuclear reactions, there has been a steady accumulation of such waste. Research reactors built in the early postwar years produced small amounts of radioactive material but the volume grew steadily as the nuclear power reactors constructed during the 1960s and 1970s began to spawn used fuel bundles. Although this radioactive refuse has been safely stored for the short term, no permanent disposal system has yet been fully developed and implemented. Canada is not alone in this regard. A large number of countries use nuclear power reactors but none has yet put in place a method for the long-term disposal of the radioactive waste. Scientists and engineers throughout the world are investigating different possibilities; however, enormous difficulties remain. In Canada, used fuel bundles from nuclear reactors are defined as high-level waste; all other waste created at different stages in the nuclear fuel cycle is classified as low-level. Although disposal of low-level waste is an important issue, it is a more tractable problem than the disposal of high-level waste, on which this paper will concentrate. The paper discusses the nuclear fuel waste management program in Canada, where a long-term disposal plan has been under development by scientists and engineers over the past 15 years, but will not be completed for some time. Also discussed are responses to the program by parliamentary committees and aboriginal and environmental groups, and the work in the area being conducted in other countries. (author). 1 tab

High-level radioactive waste in Canada. Background paper

Energy Technology Data Exchange (ETDEWEB)

Fawcett, R [Library of Parliament, Ottawa, ON (Canada). Science and Technology Div.

1993-11-01

The disposal of radioactive waste is one of the most challenging environmental problems facing Canada today. Since the Second World War, when Canadian scientists first started to investigate nuclear reactions, there has been a steady accumulation of such waste. Research reactors built in the early postwar years produced small amounts of radioactive material but the volume grew steadily as the nuclear power reactors constructed during the 1960s and 1970s began to spawn used fuel bundles. Although this radioactive refuse has been safely stored for the short term, no permanent disposal system has yet been fully developed and implemented. Canada is not alone in this regard. A large number of countries use nuclear power reactors but none has yet put in place a method for the long-term disposal of the radioactive waste. Scientists and engineers throughout the world are investigating different possibilities; however, enormous difficulties remain. In Canada, used fuel bundles from nuclear reactors are defined as high-level waste; all other waste created at different stages in the nuclear fuel cycle is classified as low-level. Although disposal of low-level waste is an important issue, it is a more tractable problem than the disposal of high-level waste, on which this paper will concentrate. The paper discusses the nuclear fuel waste management program in Canada, where a long-term disposal plan has been under development by scientists and engineers over the past 15 years, but will not be completed for some time. Also discussed are responses to the program by parliamentary committees and aboriginal and environmental groups, and the work in the area being conducted in other countries. (author). 1 tab.

Tuberculosis Lymphadenitis, A Diagnostic Problem in Areas of High ...

African Journals Online (AJOL)

Introduction. Malawi has high human immunodeficiency virus (HIV) infection rates. In 1993, 32% of mothers visiting the antenatal cI inic in an urban area, and 12% in rural areas, were sero-positive for HIV (1). The HIV epidemic is associated with a marked increase in the number of cases of tuberculosis in general (2) and ...

Assessment of background particulate matter concentrations in small cities and rural locations--Prince George, Canada.

Science.gov (United States)

Veira, Andreas; Jackson, Peter L; Ainslie, Bruce; Fudge, Dennis

2013-07-01

This study investigates the development and application of a simple method to calculate annual and seasonal PM2.5 and PM10 background concentrations in small cities and rural areas. The Low Pollution Sectors and Conditions (LPSC) method is based on existing measured long-term data sets and is designed for locations where particulate matter (PM) monitors are only influenced by local anthropogenic emission sources from particular wind sectors. The LPSC method combines the analysis of measured hourly meteorological data, PM concentrations, and geographical emission source distributions. PM background levels emerge from measured data for specific wind conditions, where air parcel trajectories measured at a monitoring station are assumed to have passed over geographic sectors with negligible local emissions. Seasonal and annual background levels were estimated for two monitoring stations in Prince George, Canada, and the method was also applied to four other small cities (Burns Lake, Houston, Quesnel, Smithers) in northern British Columbia. The analysis showed reasonable background concentrations for both monitoring stations in Prince George, whereas annual PM10 background concentrations at two of the other locations and PM2.5 background concentrations at one other location were implausibly high. For those locations where the LPSC method was successful, annual background levels ranged between 1.8 +/- 0.1 microg/m3 and 2.5 +/- 0.1 microg/m3 for PM2.5 and between 6.3 +/- 0.3 microg/m3 and 8.5 +/- 0.3 microg/m3 for PM10. Precipitation effects and patterns of seasonal variability in the estimated background concentrations were detectable for all locations where the method was successful. Overall the method was dependent on the configuration of local geography and sources with respect to the monitoring location, and may fail at some locations and under some conditions. Where applicable, the LPSC method can provide a fast and cost-efficient way to estimate background PM

Investigation of background radiation levels and geologic unit profiles in Durango, Colorado

International Nuclear Information System (INIS)

Triplett, G.H.; Foutz, W.L.; Lesperance, L.R.

1989-11-01

As part of the Uranium Mill Tailings Remedial Action (UMTRA) Project, Oak Ridge National Laboratory (ORNL) has performed radiological surveys on 435 vicinity properties (VPs) in the Durango area. This study was undertaken to establish the background radiation levels and geologic unit profiles in the Durango VP area. During the months of May through June, 1986, extensive radiometric measurements and surface soil samples were collected in the Durango VP area by personnel from ORNL's Grand Junction Office. A majority of the Durango VP surveys were conducted at sites underlain by Quaternary alluvium, older Quaternary gravels, and Cretaceous Lewis and Mancos shales. These four geologic units were selected to be evaluated. The data indicated no formation anomalies and established regional background radiation levels. Durango background radionuclide concentrations in surface soil were determined to be 20.3 ± 3.4 pCi/g for 40 K, 1.6 ± 0.5 pCi/g for 226 Ra, and 1.2 ± 0.3 pCi/g for 232 Th. The Durango background gamma exposure rate was found to be 16.5 ± 1.3 μR/h. Average gamma spectral count rate measurements for 40 K, 226 Ra and 232 Th were determined to be 553, 150, and 98 counts per minute (cpm), respectively. Geologic unit profiles and Durango background radiation measurements are presented and compared with other areas. 19 refs., 15 figs., 5 tabs

Malaria in pregnant women in an area with sustained high coverage of insecticide-treated bed nets

Directory of Open Access Journals (Sweden)

Mshinda Hassan

2008-07-01

Full Text Available Abstract Background Since 2000, the World Health Organization has recommended a package of interventions to prevent malaria during pregnancy and its sequelae that includes the promotion of insecticide-treated bed nets (ITNs, intermittent preventive treatment in pregnancy (IPTp, and effective case management of malarial illness. It is recommended that pregnant women in malaria-endemic areas receive at least two doses of sulphadoxine-pyrimethamine in the second and third trimesters of pregnancy. This study assessed the prevalence of placental malaria at delivery in women during 1st or 2nd pregnancy, who did not receive intermittent preventive treatment for malaria (IPTp in a malaria-endemic area with high bed net coverage. Methods A hospital-based cross-sectional study was done in Ifakara, Tanzania, where bed net coverage is high. Primi- and secundigravid women, who presented to the labour ward and who reported not using IPTp were included in the study. Self-report data were collected by questionnaire; whereas neonatal birth weight and placenta parasitaemia were measured directly at the time of delivery. Results Overall, 413 pregnant women were enrolled of which 91% reported to have slept under a bed net at home the previous night, 43% reported history of fever and 62% were primigravid. Malaria parasites were detected in 8% of the placenta samples; the geometric mean (95%CI placental parasite density was 3,457 (1,060–11,271 parasites/μl in primigravid women and 2,178 (881–5,383 parasites/μl in secundigravid women. Fifteen percent of newborns weighed Conclusion The observed incidence of LBW and prevalence of placental parasitaemia at delivery suggests that malaria remains a problem in pregnancy in this area with high bed net coverage when eligible women do not receive IPTp. Delivery of IPTp should be emphasized at all levels of implementation to achieve maximum community coverage.

Soil 137Cs background values in monsoon region of china

International Nuclear Information System (INIS)

Zhang Mingli; Yang Hao; Wang Xiaolei; Wang Yihong; Xu Congan; Yang Jiudong; Rong Jing

2009-01-01

Land degradation,, which is resulted from the soil erosion, is one of the major environmental problems. It severely affects the food supplies, environmental safety and the sustainable development in China. Some areas in the monsoon region are suffering from the acute soil erosion. To find out the degree of soil erosion, the proven technique of 137 Cs tracer is definitely one of the best methods, and the key is to ascertain the accuracy of soil 137 Cs background value. The distributions of 137 Cs were explored in soil profiles by detecting the 137 Cs of soil cores from the Yimeng mountain area in Shandong Province, hills in the southern area of Jiangsu Province and Dianchi catchment in Yunnan Province, respectively. We found that the depth of 137 Cs distribution is not the same in the soils of various areas. But the 137 Cs activity shows an exponential distribution in the uncultivated soil and demonstrates a strong correlation with the soil depth, while the 137 Cs activity proves uniform in the soil plowing layer of the cultivated land. The study shows the 137 Cs background values of three areas: 1737.1 Bq/m 2 in Yimeng mountain area, 1847.6 Bq/m 2 in southern area of hills in Jiangsu, 918.0 Bq/m 2 in Dianchi catchment. The certainty of 137 Cs background value can technically support the use of 137 Cs technique to study the spatial pattern of soil erosion, deposition and the land degradation, which provides the support for the sustainable utilization of soil resource, the assessment of economical benefit and loss and the evaluation of water and soil conservation measures. (authors)

Visual signal detection in structured backgrounds. II. Effects of contrast gain control, background variations, and white noise

Science.gov (United States)

Eckstein, M. P.; Ahumada, A. J. Jr; Watson, A. B.

1997-01-01

Studies of visual detection of a signal superimposed on one of two identical backgrounds show performance degradation when the background has high contrast and is similar in spatial frequency and/or orientation to the signal. To account for this finding, models include a contrast gain control mechanism that pools activity across spatial frequency, orientation and space to inhibit (divisively) the response of the receptor sensitive to the signal. In tasks in which the observer has to detect a known signal added to one of M different backgrounds grounds due to added visual noise, the main sources of degradation are the stochastic noise in the image and the suboptimal visual processing. We investigate how these two sources of degradation (contrast gain control and variations in the background) interact in a task in which the signal is embedded in one of M locations in a complex spatially varying background (structured background). We use backgrounds extracted from patient digital medical images. To isolate effects of the fixed deterministic background (the contrast gain control) from the effects of the background variations, we conduct detection experiments with three different background conditions: (1) uniform background, (2) a repeated sample of structured background, and (3) different samples of structured background. Results show that human visual detection degrades from the uniform background condition to the repeated background condition and degrades even further in the different backgrounds condition. These results suggest that both the contrast gain control mechanism and the background random variations degrade human performance in detection of a signal in a complex, spatially varying background. A filter model and added white noise are used to generate estimates of sampling efficiencies, an equivalent internal noise, an equivalent contrast-gain-control-induced noise, and an equivalent noise due to the variations in the structured background.

Geochemistry of regional background aerosols in the Western Mediterranean

Science.gov (United States)

Pey, J.; Pérez, N.; Castillo, S.; Viana, M.; Moreno, T.; Pandolfi, M.; López-Sebastián, J. M.; Alastuey, A.; Querol, X.

2009-11-01

The chemical composition of regional background aerosols, and the time variability and sources in the Western Mediterranean are interpreted in this study. To this end 2002-2007 PM speciation data from an European Supersite for Atmospheric Aerosol Research (Montseny, MSY, located 40 km NNE of Barcelona in NE Spain) were evaluated, with these data being considered representative of regional background aerosols in the Western Mediterranean Basin. The mean PM 10, PM 2.5 and PM 1 levels at MSY during 2002-2007 were 16, 14 and 11 µg/m 3, respectively. After compiling data on regional background PM speciation from Europe to compare our data, it is evidenced that the Western Mediterranean aerosol is characterised by higher concentrations of crustal material but lower levels of OM + EC and ammonium nitrate than at central European sites. Relatively high PM 2.5 concentrations due to the transport of anthropogenic aerosols (mostly carbonaceous and sulphate) from populated coastal areas were recorded, especially during winter anticyclonic episodes and summer midday PM highs (the latter associated with the transport of the breeze and the expansion of the mixing layer). Source apportionment analyses indicated that the major contributors to PM 2.5 and PM 10 were secondary sulphate, secondary nitrate and crustal material, whereas the higher load of the anthropogenic component in PM 2.5 reflects the influence of regional (traffic and industrial) emissions. Levels of mineral, sulphate, sea spray and carbonaceous aerosols were higher in summer, whereas nitrate levels and Cl/Na were higher in winter. A considerably high OC/EC ratio (14 in summer, 10 in winter) was detected, which could be due to a combination of high biogenic emissions of secondary organic aerosol, SOA precursors, ozone levels and insolation, and intensive recirculation of aged air masses. Compared with more locally derived crustal geological dusts, African dust intrusions introduce relatively quartz-poor but clay

Validity of the linear no-threshold (LNT) hypothesis in setting radiation protection regulations for the inhabitants in high level natural radiation areas of Ramsar, Iran

International Nuclear Information System (INIS)

Mortazavi, S.M.J.; Atefi, M.; Razi, Z.; Mortazavi Gh

2010-01-01

Some areas in Ramsar, a city in northern Iran, have long been known as inhabited areas with the highest levels of natural radiation. Despite the fact that the health effects of high doses of ionizing radiation are well documented, biological effects of above the background levels of natural radiation are still controversial and the validity of the LNT hypothesis in this area, has been criticized by many investigators around the world. The study of the health effects of high levels of natural radiation in areas such as Ramsar, help scientists to investigate the biological effects without the need for extrapolating the observations either from high doses of radiation to low dose region or from laboratory animals to humans. Considering the importance of these studies, National Radiation Protection Department (NRPD) of the Iranian Nuclear Regulatory Authority has started an integrative research project on the health effects of long-term exposure to high levels of natural radiation. This paper reviews findings of the studies conducted on the plants and humans living or laboratory animals kept in high level natural radiation areas of Ramsar. In human studies, different end points such as DNA damage, chromosome aberrations, blood cells and immunological alterations are discussed. This review comes to the conclusion that no reproducible detrimental health effect has been reported so far. In this paper the validity of LNT hypothesis in the assessment of the health effects of high levels of natural radiation is discussed. (author)

Ground Level Ozone Regional Background Characteristics In North-west Pacific Rim

Science.gov (United States)

Chiang, C.; Fan, J.; Chang, J. S.

2007-12-01

Understanding the ground level ozone regional background characteristics is essential in understanding the contribution of long-range transport of pollutants from Asia Mainland to air quality in downwind areas. In order to understand this characteristic in north-west Pacific Rim, we conducted a coupled study using ozone observation from regional background stations and 3-D regional-scale chemical transport model simulations. We used O3, CO, wind speed and wind direction data from two regional background stations and ¡§other stations¡¨ over a ten year period and organized several numerical experiments to simulate one spring month in 2003 to obtain a deeper understanding. The so called ¡§other stations¡¨ had actually been named as background stations under various governmental auspices. But we found them to be often under strong influence of local pollution sources with strong diurnal or slightly longer time variations. We found that the Yonagunijima station (24.74 N, 123.02 E) and Heng-Chuen station (21.96 N,120.78 E), about a distance of 400 km apart, have almost the same ozone time series pattern. For these two stations in 2003, correlation coefficients (R2) for annual observed ozone concentration is about 0.64, in the springtime it is about 0.7, and in a one-month period at simulation days it is about 0.76. These two stations have very little small scale variations in all the variables studied. All variations are associated with large scale circulation changes. This is especially so at Yonagunijima station. Using a 3-D regional-scale chemical transport model for East Asia region including contribution from Asia continental outflow and neighboring island pollution areas we found that the Yonagunijima and HengChuen station are indeed free of pollutants from all neighboring areas keeping in mind that pollutants from Taiwan area is never far away. Ozone concentrations in these two stations are dominated by synoptic scale weather patterns, with diffused

Measurement of Acceptable Noise Level with Background Music.

Science.gov (United States)

Ahn, Hyun-Jung; Bahng, Junghwa; Lee, Jae Hee

2015-09-01

Acceptable noise level (ANL) is a measure of the maximum background noise level (BNL) that a person is willing to tolerate while following a target story. Although researchers have used various sources of target sound in ANL measures, a limited type of background noise has been used. Extending the previous study of Gordon-Hickey & Moore (2007), the current study determined the effect of music genre and tempo on ANLs as possible factors affecting ANLs. We also investigated the relationships between individual ANLs and the familiarity of music samples and between music ANLs and subjective preference. Forty-one participants were seperated into two groups according to their ANLs, 29 low-ANL listeners and 12 high-ANL listeners. Using Korean ANL material, the individual ANLs were measured based on the listeners' most comfortable listening level and BNL. The ANLs were measured in six conditions, with different music tempo (fast, slow) and genre (K-pop, pop, classical) in a counterbalanced order. Overall, ANLs did not differ by the tempo of background music, but music genre significantly affected individual ANLs. We observed relatively higher ANLs with K-pop music and relatively lower ANLs with classical music. This tendency was similar in both low-ANL and high-ANL groups. However, the subjective ratings of music familiarity and preference affected ANLs differently for low-ANL and high-ANL groups. In contrast to the low-ANL listeners, the ANLs of the high-ANL listeners were significantly affected by music familiarity and preference. The genre of background music affected ANLs obtained using background music. The degree of music familiarity and preference appears to be associated with individual susceptibility to background music only for listeners who are greatly annoyed by background noise (high-ANL listeners).

Human Detection Based on the Generation of a Background Image by Using a Far-Infrared Light Camera

Directory of Open Access Journals (Sweden)

Eun Som Jeon

2015-03-01

Full Text Available The need for computer vision-based human detection has increased in fields, such as security, intelligent surveillance and monitoring systems. However, performance enhancement of human detection based on visible light cameras is limited, because of factors, such as nonuniform illumination, shadows and low external light in the evening and night. Consequently, human detection based on thermal (far-infrared light cameras has been considered as an alternative. However, its performance is influenced by the factors, such as low image resolution, low contrast and the large noises of thermal images. It is also affected by the high temperature of backgrounds during the day. To solve these problems, we propose a new method for detecting human areas in thermal camera images. Compared to previous works, the proposed research is novel in the following four aspects. One background image is generated by median and average filtering. Additional filtering procedures based on maximum gray level, size filtering and region erasing are applied to remove the human areas from the background image. Secondly, candidate human regions in the input image are located by combining the pixel and edge difference images between the input and background images. The thresholds for the difference images are adaptively determined based on the brightness of the generated background image. Noise components are removed by component labeling, a morphological operation and size filtering. Third, detected areas that may have more than two human regions are merged or separated based on the information in the horizontal and vertical histograms of the detected area. This procedure is adaptively operated based on the brightness of the generated background image. Fourth, a further procedure for the separation and removal of the candidate human regions is performed based on the size and ratio of the height to width information of the candidate regions considering the camera viewing direction

CALDER: Cryogenic light detectors for background-free searches

Energy Technology Data Exchange (ETDEWEB)

Cardani, L. [Dipartimento di Fisica - Sapienza Università di Roma, Roma - Italy and Physics Department, Princeton University, Princeton, NJ (United States); Bellini, F.; Casali, N.; Coppolecchia, A.; Cosmelli, C.; Cruciani, A.; Vignati, M. [Dipartimento di Fisica - Sapienza Università di Roma and INFN - Sezione di Roma, Roma - Italy (Italy); Castellano, M. G. [Istituto di Fotonica e Nanotecnologie - CNR, Roma - Italy (Italy); Colantoni, I. [Dipartimento di Fisica - Sapienza Università di Roma (Italy); Di Domizio, S. [Dipartimento di Fisica, Università di Genova, Genova - Italy and INFN Sezione di Genova, Genova - Italy (Italy); Tomei, C. [INFN - Sezione di Roma, Roma - Italy (Italy)

2015-08-17

The development of background-free detectors is essential for experiments searching for rare events. Bolometers, that are among the most competitive devices for the study of neutrino-less double beta decay (0νDBD) and Dark Matter interactions, suffer from the absence of techniques that allow to identify the nature of the interacting particles. This limit can be overcome by coupling the bolometer to an independent device for the measurement of the light emitted by interactions, as the combined read-out of the bolometric and light signals allows to identify and reject particles different from those of interest. CUORE, the most advanced bolometric experiment for 0νDBD searches, could disentangle the electrons produced by 0νDBD from the dangerous background due to α particles, by measuring the (tiny) Cherenkov light emitted by electrons and not by α’s. LUCIFER, a project based on ZnSe scintillating bolometers for the study of {sup 82}Se 0νDBD, would be competitive also in the search of Dark Matter interactions if equipped with light detectors that allow to distinguish and reject the background due to electrons and γ’s. These advances require cryogenic detectors characterized by noise lower than 20 eV, large active area, wide temperature range of operation, high radio-purity and ease in fabricating hundreds of channels. The CALDER collaboration aims to develop such detectors by exploiting the superb energy resolution and natural multiplexed read-out provided by Kinetic Inductance Detectors.

Quantum background independence in string theory

International Nuclear Information System (INIS)

Witten, E.

1994-01-01

Not only in physical string theories, but also in some highly simplified situations, background independence has been difficult to understand. It is argued that the ''holomorphic anomaly'' of Bershadsky, Cecotti, Ooguri and Vafa gives a fundamental explanation of some of the problems. Moreover, their anomaly equation can be interpreted in terms of a rather peculiar quantum version of background independence: in systems afflicted by the anomaly, background independence does not hold order by order in perturbation theory, but the exact partition function as a function of the coupling constants has a background independent interpretation as a state in an auxiliary quantum Hilbert space. The significance of this auxiliary space is otherwise unknown. (author). 23 refs

Calculating background levels for ecological risk parameters in toxic harbor sediment

Science.gov (United States)

Leadon, C.J.; McDonnell, T.R.; Lear, J.; Barclift, D.

2007-01-01

Establishing background levels for biological parameters is necessary in assessing the ecological risks from harbor sediment contaminated with toxic chemicals. For chemicals in sediment, the term contaminated is defined as having concentrations above background and significant human health or ecological risk levels. For biological parameters, a site could be considered contaminated if levels of the parameter are either more or less than the background level, depending on the specific parameter. Biological parameters can include tissue chemical concentrations in ecological receptors, bioassay responses, bioaccumulation levels, and benthic community metrics. Chemical parameters can include sediment concentrations of a variety of potentially toxic chemicals. Indirectly, contaminated harbor sediment can impact shellfish, fish, birds, and marine mammals, and human populations. This paper summarizes the methods used to define background levels for chemical and biological parameters from a survey of ecological risk investigations of marine harbor sediment at California Navy bases. Background levels for regional biological indices used to quantify ecological risks for benthic communities are also described. Generally, background stations are positioned in relatively clean areas exhibiting the same physical and general chemical characteristics as nearby areas with contaminated harbor sediment. The number of background stations and the number of sample replicates per background station depend on the statistical design of the sediment ecological risk investigation, developed through the data quality objective (DQO) process. Biological data from the background stations can be compared to data from a contaminated site by using minimum or maximum background levels or comparative statistics. In Navy ecological risk assessments (ERA's), calculated background levels and appropriate ecological risk screening criteria are used to identify sampling stations and sites with contaminated

Ship detection using STFT sea background statistical modeling for large-scale oceansat remote sensing image

Science.gov (United States)

Wang, Lixia; Pei, Jihong; Xie, Weixin; Liu, Jinyuan

2018-03-01

Large-scale oceansat remote sensing images cover a big area sea surface, which fluctuation can be considered as a non-stationary process. Short-Time Fourier Transform (STFT) is a suitable analysis tool for the time varying nonstationary signal. In this paper, a novel ship detection method using 2-D STFT sea background statistical modeling for large-scale oceansat remote sensing images is proposed. First, the paper divides the large-scale oceansat remote sensing image into small sub-blocks, and 2-D STFT is applied to each sub-block individually. Second, the 2-D STFT spectrum of sub-blocks is studied and the obvious different characteristic between sea background and non-sea background is found. Finally, the statistical model for all valid frequency points in the STFT spectrum of sea background is given, and the ship detection method based on the 2-D STFT spectrum modeling is proposed. The experimental result shows that the proposed algorithm can detect ship targets with high recall rate and low missing rate.

P-West High Intensity Secondary Beam Area Design Report

Energy Technology Data Exchange (ETDEWEB)

Cox, A.; Currier, R.; Eartly, D.; Guthke, A.; Johnson, G.; Lee, D.; Dram, R.; Villegas, E.; Rest, J.; Tilles, E.; Vander Arend, P.

1977-03-01

This report gives the initial design parameters of a 1000 GeV High Intensity Superconducting Secondary Beam Laboratory to be situated in the Proton Area downstream of the existing Proton West experimental station. The area will provide Fermilab with a major capability for experimentation with pion and antiproton beams of intensities and of energies available at no other laboratory and with an electron beam with excellent spot size, intensity, and purity at energies far above that available at electron machines. Detailed beam design, area layouts, and cost estimates are presented, along with the design considerations.

High-frequency background modulation fringe patterns based on a fringe-wavelength geometry-constraint model for 3D surface-shape measurement.

Science.gov (United States)

Liu, Xinran; Kofman, Jonathan

2017-07-10

A new fringe projection method for surface-shape measurement was developed using four high-frequency phase-shifted background modulation fringe patterns. The pattern frequency is determined using a new fringe-wavelength geometry-constraint model that allows only two corresponding-point candidates in the measurement volume. The correct corresponding point is selected with high reliability using a binary pattern computed from intensity background encoded in the fringe patterns. Equations of geometry-constraint parameters permit parameter calculation prior to measurement, thus reducing measurement computational cost. Experiments demonstrated the ability of the method to perform 3D shape measurement for a surface with geometric discontinuity, and for spatially isolated objects.

Nature of the Background Ultraviolet Radiation Field at High Redshifts

Indian Academy of Sciences (India)

tribpo

J. Astrophys. Astr. (2000) 21, 19-27 .... to know the shape of the ionizing radiation to determine the ionization parameter from the C II to C IV ratio. ... different shapes of the background radiation spectrum as explained in the text. The solid lines.

Natural background radiation and population dose distribution in India

International Nuclear Information System (INIS)

Nambi, K.S.V.; Bapat, V.N.; David, M.; Sundaram, V.K.; Sunta, C.M.; Soman, S.D.

1986-01-01

A country-wide survey of the outdoor natural background gamma radiation levels has been made using mailed thermoluminescent dosimeters (TLDs). The salient features of the results are: (1) The air-kerma levels and the population doses in various states follow log-normal and normal distributions respectively. (2) The national average value for the air dose (air-kerma) is 775 ± 370 (1σ)μGy/y. (3) The lowest air-kerma recorded is 0.23 mGy/y at Minicoy (Laccadive Islands) and the highest is 26.73 mGy/y at Chavra (monazite areas, Kerala). (4) There are significant temporal variation s (even as high as ± 40 per cent) of the background radiation level at many locations and at least in 10 locations where radon/thoron measurements are available, these could be associated with the seasonal variations in radon/thoron levels. (5) The mail control TLDs indicate a country-wide average value of 785 ± 225 μGy/y for the air-kerma which can be considered to provide a truly national average value for the natural background radiation level in India. (6) The mean natural radiation per caput for the country works out to be 690 ± 200 (1σ) Sv/y. (7) The natural radiation per caput seems to be maximum for Andhra Pradesh (1065 ± 325 μSv/y) and minimum for Maharashtra (370 ± 80 μSv/y). (8) The population dose from the external natural background radiation is estimated to be half a million person-Sievert. (9) Assuming 1 CRP risk factor, it can be estimated that just one out of the 43 cancer deaths occurring on an average per 100,000 population in India, can be attributed to the external natural background radiation. (author). 18 refs., 13 tabs., 9 figs

A Clinical Trial to Introduce Voluntary Medical Male Circumcision for HIV Prevention in Areas of High Prevalence in the Dominican Republic

Science.gov (United States)

Brito, Maximo O.; Lerebours, Leonel; Volquez, Claudio; Basora, Emmanuel; Khosla, Shaveta; Lantigua, Flavia; Flete, Roberto; Rosario, Riqui; Rodriguez, Luis A.; Fernandez, Mathius; Donastorg, Yeycy; Bailey, Robert C.

2015-01-01

Background Voluntary Medical Male Circumcision (VMMC) is an effective strategy to reduce the risk of HIV infection. Studies conducted in the Dominican Republic (DR) suggest that acceptability of VMMC among men may be as high as 67%. The goal of this clinical trial was to assess the acceptability, uptake and safety for VMMC services in two areas of high HIV prevalence in the country. Methods This was a single-arm, non-randomized, pragmatic clinical trial. Study personnel received background information about the risks and benefits of VMMC and practical training on the surgical technique. A native speaking research assistant administered a questionnaire of demographics, sexual practices and knowledge about VMMC. One week after the surgery, participants returned for wound inspection and to answer questions about their post-surgical experience. Results 539 men consented for the study. Fifty seven were excluded from participation for medical or anatomical reasons and 28 decided not to have the procedure after providing consent. A total of 454 men were circumcised using the Forceps Guided Method Under Local Anesthesia. The rate of adverse events (AE) was 4.4% (20% moderate, 80% mild). There were no serious AEs and all complications resolved promptly with treatment. Eighty eight percent of clients reported being “very satisfied” and 12% were “somewhat satisfied” with the outcome at the one-week postoperative visit. Conclusions Recruitment and uptake were satisfactory. Client satisfaction with VMMC was high and the rate of AEs was low. Roll out of VMMC in targeted areas of the DR is feasible and should be considered. Trial Registration ClinicalTrials.gov NCT02337179 PMID:26367187

Wavy channel transistor for area efficient high performance operation

KAUST Repository

Fahad, Hossain M.

2013-04-05

We report a wavy channel FinFET like transistor where the channel is wavy to increase its width without any area penalty and thereby increasing its drive current. Through simulation and experiments, we show the effectiveness of such device architecture is capable of high performance operation compared to conventional FinFETs with comparatively higher area efficiency and lower chip latency as well as lower power consumption.

Earthquake Hazard for Aswan High Dam Area

Science.gov (United States)

Ismail, Awad

2016-04-01

Earthquake activity and seismic hazard analysis are important components of the seismic aspects for very essential structures such as major dams. The Aswan High Dam (AHD) created the second man-made reservoir in the world (Lake Nasser) and is constructed near urban areas pose a high-risk potential for downstream life and property. The Dam area is one of the seismically active regions in Egypt and is occupied with several cross faults, which are dominant in the east-west and north-south. Epicenters were found to cluster around active faults in the northern part of Lake and AHD location. The space-time distribution and the relation of the seismicity with the lake water level fluctuations were studied. The Aswan seismicity separates into shallow and deep seismic zones, between 0 and 14 and 14 and 30 km, respectively. These two seismic zones behave differently over time, as indicated by the seismicity rate, lateral extent, b-value, and spatial clustering. It is characterized by earthquake swarm sequences showing activation of the clustering-events over time and space. The effect of the North African drought (1982 to present) is clearly seen in the reservoir water level. As it decreased and left the most active fault segments uncovered, the shallow activity was found to be more sensitive to rapid discharging than to the filling. This study indicates that geology, topography, lineations in seismicity, offsets in the faults, changes in fault trends and focal mechanisms are closely related. No relation was found between earthquake activity and both-ground water table fluctuations and water temperatures measured in wells located around the Kalabsha area. The peak ground acceleration is estimated in the dam site based on strong ground motion simulation. This seismic hazard analyses have indicated that AHD is stable with the present seismicity. The earthquake epicenters have recently took place approximately 5 km west of the AHD structure. This suggests that AHD dam must be

Low Background Micromegas in CAST

CERN Document Server

Garza, J.G.; Aznar, F.; Calvet, D.; Castel, J.F.; Christensen, F.E.; Dafni, T.; Davenport, M.; Decker, T.; Ferrer-Ribas, E.; Galán, J.; García, J.A.; Giomataris, I.; Hill, R.M.; Iguaz, F.J.; Irastorza, I.G.; Jakobsen, A.C.; Jourde, D.; Mirallas, H.; Ortega, I.; Papaevangelou, T.; Pivovaroff, M.J.; Ruz, J.; Tomás, A.; Vafeiadis, T.; Vogel, J.K.

2015-11-16

Solar axions could be converted into x-rays inside the strong magnetic field of an axion helioscope, triggering the detection of this elusive particle. Low background x-ray detectors are an essential component for the sensitivity of these searches. We report on the latest developments of the Micromegas detectors for the CERN Axion Solar Telescope (CAST), including technological pathfinder activities for the future International Axion Observatory (IAXO). The use of low background techniques and the application of discrimination algorithms based on the high granularity of the readout have led to background levels below 10$^{-6}$ counts/keV/cm$^2$/s, more than a factor 100 lower than the first generation of Micromegas detectors. The best levels achieved at the Canfranc Underground Laboratory (LSC) are as low as 10$^{-7}$ counts/keV/cm$^2$/s, showing good prospects for the application of this technology in IAXO. The current background model, based on underground and surface measurements, is presented, as well as ...

An analysis of the influence of background subtraction and quenching on jet observables in heavy-ion collisions

CERN Document Server

Apolinario, Liliana; Cunqueiro, Leticia

2013-01-01

Subtraction of the large background in reconstruction is a key ingredient in jet studies in high-energy heavy-ion collisions at RHIC and the LHC. Here we address the question to which extent the most commonly used subtraction techniques are able to eliminate the effects of the background on the most commonly discussed observables at present: single inclusive jet distributions, dijet asymmetry and azimuthal distributions. We consider two different background subtraction methods, an area-based one implemented through the FastJet pack- age and a pedestal subtraction method, that resemble the ones used by the experimental collaborations at the LHC. We also analyze different ways of defining the optimal parame- ters in the second method. We use a toy model that easily allows variations of the background characteristics: average background level and fluctuations and azimuthal structure, but cross- checks are also done with a Monte Carlo simulator. Furthermore, we consider the influence of quenching using Q-PYTHIA o...

Background Selection in Partially Selfing Populations

Science.gov (United States)

Roze, Denis

2016-01-01

Self-fertilizing species often present lower levels of neutral polymorphism than their outcrossing relatives. Indeed, selfing automatically increases the rate of coalescence per generation, but also enhances the effects of background selection and genetic hitchhiking by reducing the efficiency of recombination. Approximations for the effect of background selection in partially selfing populations have been derived previously, assuming tight linkage between deleterious alleles and neutral loci. However, loosely linked deleterious mutations may have important effects on neutral diversity in highly selfing populations. In this article, I use a general method based on multilocus population genetics theory to express the effect of a deleterious allele on diversity at a linked neutral locus in terms of moments of genetic associations between loci. Expressions for these genetic moments at equilibrium are then computed for arbitrary rates of selfing and recombination. An extrapolation of the results to the case where deleterious alleles segregate at multiple loci is checked using individual-based simulations. At high selfing rates, the tight linkage approximation underestimates the effect of background selection in genomes with moderate to high map length; however, another simple approximation can be obtained for this situation and provides accurate predictions as long as the deleterious mutation rate is not too high. PMID:27075726

Gravitational-Wave Stochastic Background from Cosmic Strings

International Nuclear Information System (INIS)

Siemens, Xavier; Creighton, Jolien; Mandic, Vuk

2007-01-01

We consider the stochastic background of gravitational waves produced by a network of cosmic strings and assess their accessibility to current and planned gravitational wave detectors, as well as to big bang nucleosynthesis (BBN), cosmic microwave background (CMB), and pulsar timing constraints. We find that current data from interferometric gravitational wave detectors, such as Laser Interferometer Gravitational Wave Observatory (LIGO), are sensitive to areas of parameter space of cosmic string models complementary to those accessible to pulsar, BBN, and CMB bounds. Future more sensitive LIGO runs and interferometers such as Advanced LIGO and Laser Interferometer Space Antenna (LISA) will be able to explore substantial parts of the parameter space

A novel robust and efficient algorithm for charge particle tracking in high background flux

International Nuclear Information System (INIS)

Fanelli, C; Cisbani, E; Dotto, A Del

2015-01-01

The high luminosity that will be reached in the new generation of High Energy Particle and Nuclear physics experiments implies large high background rate and large tracker occupancy, representing therefore a new challenge for particle tracking algorithms. For instance, at Jefferson Laboratory (JLab) (VA,USA), one of the most demanding experiment in this respect, performed with a 12 GeV electron beam, is characterized by a luminosity up to 10 39 cm -2 s -1 . To this scope, Gaseous Electron Multiplier (GEM) based trackers are under development for a new spectrometer that will operate at these high rates in the Hall A of JLab. Within this context, we developed a new tracking algorithm, based on a multistep approach: (i) all hardware - time and charge - information are exploited to minimize the number of hits to associate; (ii) a dedicated Neural Network (NN) has been designed for a fast and efficient association of the hits measured by the GEM detector; (iii) the measurements of the associated hits are further improved in resolution through the application of Kalman filter and Rauch- Tung-Striebel smoother. The algorithm is shortly presented along with a discussion of the promising first results. (paper)

On background radiation gradients – the use of airborne surveys when searching for orphan sources using mobile gamma-ray spectrometry

International Nuclear Information System (INIS)

Kock, Peder; Rääf, Christopher; Samuelsson, Christer

2014-01-01

Systematic background radiation variations can lead to both false positives and failures to detect an orphan source when searching using car-borne mobile gamma-ray spectrometry. The stochastic variation at each point is well described by Poisson statistics, but when moving in a background radiation gradient the mean count rate will continually change, leading to inaccurate background estimations. Airborne gamma spectrometry (AGS) surveys conducted on the national level, usually in connection to mineral exploration, exist in many countries. These data hold information about the background radiation gradients which could be used at the ground level. This article describes a method that aims to incorporate the systematic as well as stochastic variations of the background radiation. We introduce a weighted moving average where the weights are calculated from existing AGS data, supplied by the Geological Survey of Sweden. To test the method we chose an area with strong background gradients, especially in the thorium component. Within the area we identified two roads which pass through the high-variability locations. The proposed method is compared with an unweighted moving average. The results show that the weighting reduces the excess false positives in the positive background gradients without introducing an excess of failures to detect a source during passage in negative gradients. -- Highlights: • We present a simple method to account for gradients in the natural background radiation. • Gradients in the natural radiation background can be modelled at the ground level using AGS data. • The number of false positives due to background gradients can be reduced by using airborne data

First Measurements of Beam Backgrounds at SuperKEKB

CERN Document Server

Vahsen, S.E.; Jaegle, I.; Nakayama, H.; Aloisio, A.; Ameli, F.; Barrett, M.; Beaulieu, A.; Bosisio, L.; Branchini, P.; Browder, T.E.; Budano, A.; Cautero, G.; Cecchi, C.; Chen, Y.-T.; Chu, K.-N.; Cinabro, D.; Cristaudo, P.; de Jong, S.; de Sangro, R.; Finocchiaro, G.; Flanagan, J.; Funakoshi, Y.; Gabriel, M.; Giordano, R.; Giuressi, D.; Hedges, M. T.; Honkanen, N.; Ikeda, H.; Ishibashi, T.; Kaji, H.; Kanazawa, K.; Kiesling, C.; Koirala, S.; Križan, P.; La Licata, C.; Lanceri, L.; Liau, J.-J.; Lin, F.-H.; Lin, J.-C.; Liptak, Z.; Longo, S.; Manoni, E.; Marinas, C.; Miyabayashi, K.; Mulyani, E.; Morita, A.; Nakao, M.; Nayak, M.; Ohnishi, Y.; Passeri, A.; Poffenberger, P.; Ritzert, M.; Roney, J M.; Rossi, A.; Röder, T.; Seddon, R.M.; Seong, I.S.; Shiu, J.-G.; Simon, F.; Soloviev, Y.; Suetsugu, Y.; Szalay, M.; Terui, S.; Tortone, G.; van der Kolk, N.; Vitale, L.; Wang, M.Z.; Windel, H.; Yokoyama, S.

2018-01-01

The high design luminosity of the SuperKEKB electron-positron collider is expected to result in challenging levels of beam-induced backgrounds in the interaction region. Properly simulating and mitigating these backgrounds is critical to the success of the Belle~II experiment. We report on measurements performed with a suite of dedicated beam background detectors, collectively known as BEAST II, during the so-called Phase 1 commissioning run of SuperKEKB in 2016, which involved operation of both the high energy ring (HER) of 7 GeV electrons as well as the low energy ring (LER) of 4 GeV positrons. We describe the BEAST II detector systems, the simulation of beam backgrounds, and the measurements performed. The measurements include standard ones of dose rates versus accelerator conditions, and more novel investigations, such as bunch-by-bunch measurements of injection backgrounds and measurements sensitive to the energy spectrum and angular distribution of fast neutrons. We observe beam-gas, Touschek, beam-dust...

Thin absorbers for large-area soft X-ray microcalorimeters

Energy Technology Data Exchange (ETDEWEB)

Rocks, L. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States)]. E-mail: rocks@wisp.physics.wisc.edu; Anderson, M.B. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Bilgri, N. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Brekosky, R. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Gwynne Crowder, S. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Figueroa-Feliciano, E. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Kelley, R. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Kilbourne, C.A. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Lai, T. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Lindeman, M.A. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Man, J. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); McCammon, D. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Nelms, K.L. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Porter, F.S. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Sivananthan, S. [University of Illinois at Chicago, Chicago, IL 60607 (United States); Vidugiris, G. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Zhao, J. [University of Illinois at Chicago, Chicago, IL 60607 (United States)

2006-04-15

The X-ray Quantum Calorimeter (XQC) sounding rocket experiment utilizes a microcalorimeter array for observing the diffuse soft X-ray background. Observations of such low surface-brightness targets require a large-area detector. We will be using an array of large absorbers. Good absorbers must rapidly and completely thermalize photons, have small heat capacity for high stopping efficiency and have good lateral thermal transport. For observing the soft X-ray background (energies <1 keV), the volume and heat capacity of absorber material can be kept to a minimum by making the absorbers only as thick as needed for high quantum efficiency at these low energies. These thin, large-area absorbers are not self-supporting and have poor lateral heat transport. Depositing the absorber material on a Si substrate provides support and improves lateral thermal conduction. We present heat capacity results for thin HgTe and thin Bi, each on Si substrates. We also describe the HgTe absorber fabrication.

High rate of virologic suppression with darunavir/ritonavir plus optimized background therapy among highly antiretroviral-experienced HIV-infected patients: results of a prospective cohort study in São Paulo, Brazil

Directory of Open Access Journals (Sweden)

José Ernesto Vidal

Full Text Available OBJECTIVES: To assess the virologic and immunological response of darunavir/ritonavir plus optimized background therapy in highly antiretroviral-experienced HIV-infected patients in Brazil. METHODS: Prospective cohort study carried out in a tertiary center in Sao Paulo, Brazil. Three-class antiretroviral-experienced patients with confirmed virologic failure began darunavir/ritonavir plus optimized background therapy (nucleoside/tide reverse transcriptase inhibitors ± raltegravir ± enfuvirtide ± maraviroc after performing a genotypic resistance assay. Clinical evaluation and laboratory tests were collected at baseline and at weeks 12, 24, and 48. Multivariate analysis was performed to identify predictors of virologic response at 48 weeks. RESULTS: Ninety-two patients were included. The median of darunavir resistant mutation was 1 (range 0-6. The median genotypic sensitivity score in the optimized background therapy was 2 (interquartile range 1-2. At week 48, 83% (95% CI: 75-90% had an HIV RNA level 100 000 copies/mL was inversely associated with virologic success at week 48 (HR: 0.22, 95% CI: 0.06-0.85, p = 0.028. CONCLUSIONS: Darunavir/ritonavir plus optimized background therapy was a highly effective salvage regimen under clinical routine conditions in a referral center in Brazil, which is similar to the reported in high-income countries.

High rate of virologic suppression with darunavir/ritonavir plus optimized background therapy among highly antiretroviral-experienced HIV-infected patients: results of a prospective cohort study in São Paulo, Brazil

Directory of Open Access Journals (Sweden)

José Ernesto Vidal

2013-02-01

Full Text Available OBJECTIVES: To assess the virologic and immunological response of darunavir/ritonavir plus optimized background therapy in highly antiretroviral-experienced HIV-infected patients in Brazil. METHODS: Prospective cohort study carried out in a tertiary center in Sao Paulo, Brazil. Three-class antiretroviral-experienced patients with confirmed virologic failure began darunavir/ritonavir plus optimized background therapy (nucleoside/tide reverse transcriptase inhibitors ± raltegravir ± enfuvirtide ± maraviroc after performing a genotypic resistance assay. Clinical evaluation and laboratory tests were collected at baseline and at weeks 12, 24, and 48. Multivariate analysis was performed to identify predictors of virologic response at 48 weeks. RESULTS: Ninety-two patients were included. The median of darunavir resistant mutation was 1 (range 0-6. The median genotypic sensitivity score in the optimized background therapy was 2 (interquartile range 1-2. At week 48, 83% (95% CI: 75-90% had an HIV RNA level 100 000 copies/mL was inversely associated with virologic success at week 48 (HR: 0.22, 95% CI: 0.06-0.85, p = 0.028. CONCLUSIONS: Darunavir/ritonavir plus optimized background therapy was a highly effective salvage regimen under clinical routine conditions in a referral center in Brazil, which is similar to the reported in high-income countries.

Background {sup 99m}Tc-methoxyisobutylisonitrile uptake of breast-specific gamma imaging in relation to background parenchymal enhancement in magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Yoon, Hai-Jeon; Kim, Bom Sahn [Ewha Womans University, Department of Nuclear Medicine, Yangchun-Ku, Seoul (Korea, Republic of); Kim, Yemi [Ewha Womans University, Clinical Research Institute and Department of Conservative Dentistry, Seoul (Korea, Republic of); Lee, Jee Eun [Ewha Womans University, Department of Radiology, Seoul (Korea, Republic of)

2015-01-15

This study investigated factors that could affect background uptake of {sup 99m}Tc- methoxyisobutylisonitrile (MIBI) on normal breast by breast-specific gamma imaging (BSGI). In addition, the impact of background {sup 99m}Tc-MIBI uptake on the diagnostic performance of BSGI was further investigated. One hundred forty-five women with unilateral breast cancer who underwent BSGI, MRI, and mammography were retrospectively enrolled. Background uptake on BSGI was evaluated qualitatively and quantitatively. Patients were classified into non-dense and dense breast groups according to mammographic breast density. Background parenchymal enhancement (BPE) was rated according to BI-RADS classification. The relationship of age, menopausal status, mammographic breast density, and BPE with background {sup 99m}Tc-MIBI uptake was analyzed. Heterogeneous texture and high background uptake ratio on BSGI were significantly correlated with younger age (p < 0.001, respectively), premenopausal status (p < 0.001 and p = 0.003), dense breast (p < 0.001, respectively), and marked BPE (p < 0.001, respectively). On multivariate analysis, only BPE remained a significant factor for background MIBI uptake (p < 0.001).There was a significant reduction in positive predictive value (p = 0.024 and p = 0.002) as background MIBI uptake and BPE grade increased. BPE on MRI was the most important factor for background MIBI uptake on BSGI. High background MIBI uptake or marked BPE can diminish the diagnostic performance of BSGI. (orig.)

In-beam background suppression shield

DEFF Research Database (Denmark)

Santoro, V.; Cai, Xiao Xiao; DiJulio, D. D.

2015-01-01

The long (3 ms) proton pulse of the European Spallation Source (ESS) gives rise to unique and potentially high backgrounds for the instrument suite. In such a source an instrument's capabilities will be limited by its Signal to Noise (S/N) ratio. The instruments with a direct view of the moderator......, which do not use a bender to help mitigate the fast neutron background, are the most challenging. For these beam lines we propose the innovative shielding of placing blocks of material directly into the guide system, which allow a minimum attenuation of the cold and thermal fluxes relative...... to the background suppression. This shielding configuration has been worked into a beam line model using Geant4. We study particularly the advantages of single crystal sapphire and silicon blocks....

Epidemiological studies in the high and normal level radiation areas of Kerala

International Nuclear Information System (INIS)

Koya, P.K.M.

2012-01-01

High and normal level natural radiation areas of Kerala give unique opportunities to estimate the risk, if any, of chronic low dose exposure by direct epidemiological studies on human beings. Studies in the area are being carried out by Low Level Radiation Research Laboratory of Bhabha Atomic Research Centre in collaboration with Departments of Health and Family Welfare/Social Welfare of the Government of Kerala and local post graduate colleges. To assess the role of chronic low dose exposure in the induction/transmission of chromosomal alterations across generations, hospital based cytogenetic studies on newborns was carried out to estimate and compare the frequency of chromosomal aberrations and karyotypes anomalies in the high (areas with radiation dose of more than 1.50 mGy/year) and normal (areas with radiation dose of 1.50 mR/year or less) level radiation areas. A total of 1,267,788 metaphases from 27,295 (9,64,390 cells from 17,298 newborns of high and 3,03,398 cells from 9,997 newborns of normal level radiation areas) newborns was screened

Strong contributions of local background climate to urban heat islands

Science.gov (United States)

Zhao, Lei; Lee, Xuhui; Smith, Ronald B.; Oleson, Keith

2014-07-01

The urban heat island (UHI), a common phenomenon in which surface temperatures are higher in urban areas than in surrounding rural areas, represents one of the most significant human-induced changes to Earth's surface climate. Even though they are localized hotspots in the landscape, UHIs have a profound impact on the lives of urban residents, who comprise more than half of the world's population. A barrier to UHI mitigation is the lack of quantitative attribution of the various contributions to UHI intensity (expressed as the temperature difference between urban and rural areas, ΔT). A common perception is that reduction in evaporative cooling in urban land is the dominant driver of ΔT (ref. 5). Here we use a climate model to show that, for cities across North America, geographic variations in daytime ΔT are largely explained by variations in the efficiency with which urban and rural areas convect heat to the lower atmosphere. If urban areas are aerodynamically smoother than surrounding rural areas, urban heat dissipation is relatively less efficient and urban warming occurs (and vice versa). This convection effect depends on the local background climate, increasing daytime ΔT by 3.0 +/- 0.3 kelvin (mean and standard error) in humid climates but decreasing ΔT by 1.5 +/- 0.2 kelvin in dry climates. In the humid eastern United States, there is evidence of higher ΔT in drier years. These relationships imply that UHIs will exacerbate heatwave stress on human health in wet climates where high temperature effects are already compounded by high air humidity and in drier years when positive temperature anomalies may be reinforced by a precipitation-temperature feedback. Our results support albedo management as a viable means of reducing ΔT on large scales.

Static Object Detection Based on a Dual Background Model and a Finite-State Machine

Directory of Open Access Journals (Sweden)

Heras Evangelio Rubén

2011-01-01

Full Text Available Detecting static objects in video sequences has a high relevance in many surveillance applications, such as the detection of abandoned objects in public areas. In this paper, we present a system for the detection of static objects in crowded scenes. Based on the detection of two background models learning at different rates, pixels are classified with the help of a finite-state machine. The background is modelled by two mixtures of Gaussians with identical parameters except for the learning rate. The state machine provides the meaning for the interpretation of the results obtained from background subtraction; it can be implemented as a look-up table with negligible computational cost and it can be easily extended. Due to the definition of the states in the state machine, the system can be used either full automatically or interactively, making it extremely suitable for real-life surveillance applications. The system was successfully validated with several public datasets.

High dynamic range low-noise focal plane readout for VLWIR applications implemented with current mode background subtraction

Science.gov (United States)

Yang, Guang; Sun, Chao; Shaw, Timothy; Wrigley, Chris; Peddada, Pavani; Blazejewski, Edward R.; Pain, Bedabrata

1998-09-01

Design and operation of a low noise CMOS focal pa;ne readout circuit with ultra-high charge handling capacity is presented. Designed for high-background, VLWIR detector readout, each readout unit cell use an accurate dynamic current memory for automatic subtraction of the dark pedestal in current domain enabling measurement of small signals 85 dB below the dark level. The redout circuit operates with low-power dissipation, high linearity, and is capable of handling pedestal currents up to 300 nA. Measurements indicate an effective charge handling capacity of over 5 X 10(superscript 9) charges/pixel with less than 10(superscript 5) electrons of input referred noise.

Short-chain chlorinated paraffins (SCCPs) in surface soil from a background area in China: occurrence, distribution, and congener profiles.

Science.gov (United States)

Wang, Xue-Tong; Zhang, Yuan; Miao, Yi; Ma, Ling-Ling; Li, Yuan-Cheng; Chang, Yue-Ya; Wu, Ming-Hong

2013-07-01

Short-chain chlorinated paraffins (SCCPs) are extremely complex technical mixtures of polychlorinated n-alkanes with carbon chain lengths from C10 to C13 and chlorine content between 49 and 70%. SCCPs are under consideration for inclusion in the Stockholm Convention on persistent organic pollutants. SCCPs have been used extensively in industrial production, but little is known about the pollution level in soil environment in China. In this study, levels and distribution of SCCPs in soil samples from Chongming Island were analyzed. Concentrations of total SCCPs in soil samples ranged from 0.42 to 420 ng g(-1), with a median of 9.6 ng g(-1). The ubiquitous occurrence of SCCPs in Chongming Island implied that long-range atmospheric transport and soil-air exchange may be the most important pathways for SCCP contamination in the background area. The localized SCCP contamination could be derived from an unidentified source. Hierarchical cluster analysis indicated that C13- and C11-congeners were predominant in most soils and C10- and C12-congeners dominated in the remaining soils. Cl7- and Cl8-congeners were on the average the most dominant chlorine congeners in nearly all soils. Principal component analysis suggested that the separation of even and odd carbon chain congeners occurred during long-range atmospheric transport and aging in soil in the study area.

Simulation of high consequence areas for gas pipelines

OpenAIRE

Orlando Díaz-Parra; Enrique Vera-López

2018-01-01

The gas pipeline is used for the transport of natural gas at a great distance. Risks derived from the handling of a combustible material transported under high pressure, by pipelines that pass close to where people live, makes it necessary to adopt prevention, mitigation and control measures to reduce the effect in case of ignition of a gas leak. This work shows the development of a new mathematical model to determine areas of high consequence and their application, using widely available and...

Looking for Cosmic Neutrino Background

Directory of Open Access Journals (Sweden)

Chiaki eYanagisawa

2014-06-01

Full Text Available Since the discovery of neutrino oscillation in atmospheric neutrinos by the Super-Kamiokande experiment in 1998, study of neutrinos has been one of exciting fields in high-energy physics. All the mixing angles were measured. Quests for 1 measurements of the remaining parameters, the lightest neutrino mass, the CP violating phase(s, and the sign of mass splitting between the mass eigenstates m3 and m1, and 2 better measurements to determine whether the mixing angle theta23 is less than pi/4, are in progress in a well-controlled manner. Determining the nature of neutrinos, whether they are Dirac or Majorana particles is also in progress with continuous improvement. On the other hand, although the ideas of detecting cosmic neutrino background have been discussed since 1960s, there has not been a serious concerted effort to achieve this goal. One of the reasons is that it is extremely difficult to detect such low energy neutrinos from the Big Bang. While there has been tremendous accumulation of information on Cosmic Microwave Background since its discovery in 1965, there is no direct evidence for Cosmic Neutrino Background. The importance of detecting Cosmic Neutrino Background is that, although detailed studies of Big Bang Nucleosynthesis and Cosmic Microwave Background give information of the early Universe at ~a few minutes old and ~300 k years old, respectively, observation of Cosmic Neutrino Background allows us to study the early Universe at $sim$ 1 sec old. This article reviews progress made in the past 50 years on detection methods of Cosmic Neutrino Background.

Modeling background radiation using geochemical data: A case study in and around Cameron, Arizona.

Science.gov (United States)

Marsac, Kara E; Burnley, Pamela C; Adcock, Christopher T; Haber, Daniel A; Malchow, Russell L; Hausrath, Elisabeth M

2016-12-01

This study compares high resolution forward models of natural gamma-ray background with that measured by high resolution aerial gamma-ray surveys. The ability to predict variations in natural background radiation levels should prove useful for those engaged in measuring anthropogenic contributions to background radiation for the purpose of emergency response and homeland security operations. The forward models are based on geologic maps and remote sensing multi-spectral imagery combined with two different sources of data: 1) bedrock geochemical data (uranium, potassium and thorium concentrations) collected from national databases, the scientific literature and private companies, and 2) the low spatial resolution NURE (National Uranium Resource Evaluation) aerial gamma-ray survey. The study area near Cameron, Arizona, is located in an arid region with minimal vegetation and, due to the presence of abandoned uranium mines, was the subject of a previous high resolution gamma-ray survey. We found that, in general, geologic map units form a good basis for predicting the geographic distribution of the gamma-ray background. Predictions of background gamma-radiation levels based on bedrock geochemical analyses were not as successful as those based on the NURE aerial survey data sorted by geologic unit. The less successful result of the bedrock geochemical model is most likely due to a number of factors including the need to take into account the evolution of soil geochemistry during chemical weathering and the influence of aeolian addition. Refinements to the forward models were made using ASTER visualizations to create subunits of similar exposure rate within the Chinle Formation, which contains multiple lithologies and by grouping alluvial units by drainage basin rather than age. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

The basic features of clay rock in Tamusu area

International Nuclear Information System (INIS)

Liu Xiaodong; Liu Pinghui

2012-01-01

This paper introduces the Tamusu area location, natural and social economic situation, the regional geological background, as well as the upper Gobi formation of clay rocks, and from the geological conditions, economic conditions, social conditions and other aspects of the Tamusu claystone conducted a preliminary evaluation. The results showed that this area can be used as one of the favorable preselected areas for high-level radioactive waste geological disposal repository, basically meets the siting criteria for geological conditions, environmental protection, land use, social influence and waste transport etc. (authors)

SURFACE GEOPHYSICAL EXPLORATION OF B, BX, and BY TANK FARMS AT THE HANFORD SITE: RESULTS OF BACKGROUND CHARACTERIZATION WITH MAGNETICS AND ELECTROMAGNETICS

International Nuclear Information System (INIS)

MYERS DA

2007-01-01

This report documents the results of preliminary surface geophysical exploration activities performed between October and December 2006 at the B, BX, and BY tank farms (B Complex). The B Complex is located in the 200 East Area of the U. S. Department of Energy's Hanford Site in Washington State. The objective of the preliminary investigation was to collect background characterization information with magnetic gradiometry and electromagnetic induction to understand the spatial distribution of metallic objects that could potentially interfere with the results from high resolution resistivity survey. Results of the background characterization show there are several areas located around the site with large metallic subsurface debris or metallic infrastructure

Interdisciplinary study of atmospheric processes and constituents of the mid-Atlantic coastal region. Attachment 5: Data set for background investigation of atmospheric constituents for Richmond, Virginia area. [air pollution monitoring

Science.gov (United States)

Kindle, E. C.; Bandy, A.; Copeland, G.; Blais, R.; Levy, G.; Sonenshine, D.; Adams, D.; Maier, G.

1975-01-01

Background data is provided for the photochemical oxident problem in the Richmond area. Particulate data, digitized portrayal of site molecular and meteorological data, and graphical portrayal of molecular data, hourly meteorological data, and streamflow charts and radiosonde data are also given.

Inventory of the Heteroptera (Insecta: Hemiptera) in Komaba Campus of the University of Tokyo, a highly urbanized area in Japan

Science.gov (United States)

Saito, Masayuki U.; Kishimoto-Yamada, Keiko; Kato, Toshihide; Kurashima, Osamu; Ito, Motomi

2015-01-01

Abstract Background The Heteroptera, or true bugs, forms one of the major insect groups with respect to the very diverse habitat preferences, including both aquatic and terrestrial species, as well as a variety of feeding types. The first comprehensive inventory of the Heteroptera at Komaba Campus of the University of Tokyo, or an urban green space in the center of the Tokyo Metropolis, Japan, was conducted. New information A total of 115 species in 29 families of the suborder Heteroptera were identified. The area had a high species richness compared with other urbanized and suburbanized localities in Tokyo. The campus is found to show a substantial difference in heteropteran species compositions, despite being close to the other localities surrounded by highly urbanized zones in central Tokyo. PMID:25941455

Large-area and highly crystalline MoSe2 for optical modulator

Science.gov (United States)

Yin, Jinde; Chen, Hao; Lu, Wei; Liu, Mengli; Li, Irene Ling; Zhang, Min; Zhang, Wenfei; Wang, Jinzhang; Xu, Zihan; Yan, Peiguang; Liu, Wenjun; Ruan, Shuangchen

2017-12-01

Transition metal dichalcogenides (TMDs) have been successfully used as broadband optical modulator materials for pulsed fiber laser systems. However, the nonlinear optical absorptions of exfoliated TMDs are strongly limited by their nanoflakes morphology with uncontrollable lateral size and thickness. In this work, we provide an effective method to fully explore the nonlinear optical properties of MoSe2. Large-area and high quality lattice MoSe2 grown by chemical vapor deposition method was adopted as an optical modulator for the first time. The large-area MoSe2 shows excellent nonlinear optical absorption with a large modulation depth of 21.7% and small saturable intensity of 9.4 MW cm-2. After incorporating the MoSe2 optical modulator into fiber laser cavity as a saturable absorber, a highly stable Q-switching operation with single pulse energy of 224 nJ is achieved. The large-area MoSe2 possessing superior nonlinear optical properties compared to exfoliated nanoflakes affords possibility for the larger-area two-dimensional materials family as high performance optical devices.

Hanford Site background: Part 1, Soil background for nonradioactive analytes

International Nuclear Information System (INIS)

1993-04-01

Volume two contains the following appendices: Description of soil sampling sites; sampling narrative; raw data soil background; background data analysis; sitewide background soil sampling plan; and use of soil background data for the detection of contamination at waste management unit on the Hanford Site

A background radiation survey along the transcontinental railway in Australia

International Nuclear Information System (INIS)

Minato, Susumu; Kodaira, Kazuo; Ito, Masaru

1995-01-01

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.)

Are conventional statistical techniques exhaustive for defining metal background concentrations in harbour sediments? A case study: The Coastal Area of Bari (Southeast Italy).

Science.gov (United States)

Mali, Matilda; Dell'Anna, Maria Michela; Mastrorilli, Piero; Damiani, Leonardo; Ungaro, Nicola; Belviso, Claudia; Fiore, Saverio

2015-11-01

Sediment contamination by metals poses significant risks to coastal ecosystems and is considered to be problematic for dredging operations. The determination of the background values of metal and metalloid distribution based on site-specific variability is fundamental in assessing pollution levels in harbour sediments. The novelty of the present work consists of addressing the scope and limitation of analysing port sediments through the use of conventional statistical techniques (such as: linear regression analysis, construction of cumulative frequency curves and the iterative 2σ technique), that are commonly employed for assessing Regional Geochemical Background (RGB) values in coastal sediments. This study ascertained that although the tout court use of such techniques in determining the RGB values in harbour sediments seems appropriate (the chemical-physical parameters of port sediments fit well with statistical equations), it should nevertheless be avoided because it may be misleading and can mask key aspects of the study area that can only be revealed by further investigations, such as mineralogical and multivariate statistical analyses. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Eating Disorders in Female High School Students: Educational and Migration Background, School-Related Stress and Performance-Orientated Classes].

Science.gov (United States)

Grüttner, M

2018-02-01

Many adolescents and young adults, especially young females, suffer from eating disorders or problematic nutrition behavior. Children and adolescents with migration background as well as from a lower social class are more likely to have eating disorders 1. Although schools are an important context in these age groups, there is a lack of scientific inquiry concerning the relationship between schooling and eating disorders. The present study investigates the relationship between performance-related stress at school and eating disorders while controlling for personnel and familial resources. Interview data on the 7 th grade high school students from the National Educational Panel Study (NEPS)* starting cohort 3 are used. The dependent variable is based on the SCOFF questionnaire. Logistic regressions are calculated using information from students and parents. Performance-related stress at school is operationalized by the negative deviation of realistic from idealistic educational aspirations (EA) and unfulfilled social expectations (SE), performance-oriented class climate is operationalized by students' perception of the performance-orientation of the teacher (PT) and the expectations of classmates (EC). The results point towards an increased risk of suffering from an eating disorder due to performance-related school stress (EA: AME: 0.18; p<0.001; SE: AME: 0.12; p<0.05) and performance-oriented class climate (PT: AME: 0.05; p<0.1; EC: AME: 0.15, p<0.01). They partly explain the relation between both migration background and educational background and eating disorders. In order to prevent eating disorders in female high school students, attention should be paid to performance-orientation experienced at school and in the social background, and improved individual support for disadvantaged students should be made available. © Georg Thieme Verlag KG Stuttgart · New York.

On the spatial behavior of background plasma in different background pressure in CPS device

International Nuclear Information System (INIS)

Samantaray, Subrata; Paikaray, Rita; Sahoo, Gourishankar; Das, Parthasarathi; Ghosh, Joydeep; Sanyasi, Amulya Kumar

2015-01-01

Blob formation and transport is a major concern for investigators as it greatly reduces the efficiency of the devices. Initial results from CPS device confirm the role of fast neutrals inside the bulk plasma in the process of blob formation and transport. 2-D simulation of curvature and velocity shear instability in plasma structures suggest that in the presence of background plasma, secondary instability do not grow non-linearly to a high level and stabilizes the flow. Adiabaticity effect also creates a radial barrier for interchange modes. In the absence of background plasma the blob fragments even at the modest level of viscosity. The fast neutrals outside bulk plasma supposed to stabilize the system. The background plasma set up is aimed at creating fast neutrals outside main plasma column, hence; the background plasma set up is done in CPS device. The spatial behavior of plasma column in between electrodes is different for different base pressure in CPS device. The spatial variation of electron temperature of plasma column between electrodes is presented in this communication. Electron temperature is measured from emission spectroscopy data. The maximum electron temperature (line averaged) is ∼ 1.5 eV. (author)

SURFACE GEOPHYSICAL EXPLORATION OF TX-TY TANK FARMS AT THE HANFORD SITE: RESULTS OF BACKGROUND CHARACTERIZATION WITH GROUND PENETRATING RADAR

International Nuclear Information System (INIS)

MYERS DA; CUBBAGE R; BRAUCHLA R; O'BRIEN G

2008-01-01

Ground penetrating radar surveys of the TX and TY tank farms were performed to identify existing infrastructure in the near surface environment. These surveys were designed to provide background information supporting Surface-to-Surface and Well-to-Well resistivity surveys of Waste Management Area TX-TY. The objective of the preliminary investigation was to collect background characterization information with GPR to understand the spatial distribution of metallic objects that could potentially interfere with the results from high resolution resistivity(trademark) surveys. The results of the background characterization confirm the existence of documented infrastructure, as well as highlight locations of possible additional undocumented subsurface metallic objects

Adolescent gynecomastia is associated with a high incidence of obesity, dysglycemia, and family background of diabetes mellitus

Directory of Open Access Journals (Sweden)

Bindu Kulshreshtha

2017-01-01

Full Text Available Background: Gynecomastia during adolescence is common though etiology is not clear. We studied the clinical and hormonal profile of adolescent patients with gynecomastia. Methodology: Patients who had onset of breast development between age 10 and 20 years were included in this study. Their clinical profile, biochemical, and hormonal parameters were studied. Results: Of 94 patients with gynecomastia, 4 had hypogonadotropic hypogonadism, 4 had hypergonadotropic hypogonadism, and 1 had fibroadenosis, but in majority (90.4%, no apparent cause for breast enlargement was evident. In the idiopathic group, majority were obese (63%. Fourteen (16% patients had impaired fasting glucose or impaired glucose tolerance. Another twenty patients had subtle abnormalities (high 1 h glucose or glucose peak at 2 h. Twenty-nine percent of lean and 38% of obese patients had mild abnormalities in glucose profile. Sixty percent of patients had family background of diabetes. Obese patients had lower testosterone as compared to lean patients; however, estradiol, luteinizing hormone, and follicle-stimulating hormone levels were similar in the two groups. Conclusion: Gynecomastia during adolescence is associated with obesity, dysglycemia, and family background of diabetes mellitus.

Towards a High Temporal Frequency Grass Canopy Thermal IR Model for Background Signatures

Science.gov (United States)

Ballard, Jerrell R., Jr.; Smith, James A.; Koenig, George G.

2004-01-01

In this paper, we present our first results towards understanding high temporal frequency thermal infrared response from a dense plant canopy and compare the application of our model, driven both by slowly varying, time-averaged meteorological conditions and by high frequency measurements of local and within canopy profiles of relative humidity and wind speed, to high frequency thermal infrared observations. Previously, we have employed three-dimensional ray tracing to compute the intercepted and scattered radiation fluxes and for final scene rendering. For the turbulent fluxes, we employed simple resistance models for latent and sensible heat with one-dimensional profiles of relative humidity and wind speed. Our modeling approach has proven successful in capturing the directional and diurnal variation in background thermal infrared signatures. We hypothesize that at these scales, where the model is typically driven by time-averaged, local meteorological conditions, the primary source of thermal variance arises from the spatial distribution of sunlit and shaded foliage elements within the canopy and the associated radiative interactions. In recent experiments, we have begun to focus on the high temporal frequency response of plant canopies in the thermal infrared at 1 second to 5 minute intervals. At these scales, we hypothesize turbulent mixing plays a more dominant role. Our results indicate that in the high frequency domain, the vertical profile of temperature change is tightly coupled to the within canopy wind speed In the results reported here, the canopy cools from the top down with increased wind velocities and heats from the bottom up at low wind velocities. .

Simulation of Beam-Beam Background at CLIC

CERN Document Server

Sailer, Andre

2010-01-01

The dense beams used at CLIC to achieve a high luminosity will cause a large amount of background particles through beam-beam interactions. Generator level studies with GuineaPig and full detector simulation studies with an ILD based CLIC detector have been performed to evaluate the amount of beam-beam background hitting the vertex detector.

Investigation of the Effects of Facility Background Pressure on the Performance and Voltage-Current Characteristics of the High Voltage Hall Accelerator

Science.gov (United States)

Kamhawi, Hani; Huang, Wensheng; Haag, Thomas; Spektor, Rostislav

2014-01-01

The National Aeronautics and Space Administration (NASA) Science Mission Directorate In-Space Propulsion Technology office is sponsoring NASA Glenn Research Center to develop a 4 kW-class Hall thruster propulsion system for implementation in NASA science missions. A study was conducted to assess the impact of varying the facility background pressure on the High Voltage Hall Accelerator (HiVHAc) thruster performance and voltage-current characteristics. This present study evaluated the HiVHAc thruster performance in the lowest attainable background pressure condition at NASA GRC Vacuum Facility 5 to best simulate space-like conditions. Additional tests were performed at selected thruster operating conditions to investigate and elucidate the underlying physics that change during thruster operation at elevated facility background pressure. Tests were performed at background pressure conditions that are three and ten times higher than the lowest realized background pressure. Results indicated that the thruster discharge specific impulse and efficiency increased with elevated facility background pressure. The voltage-current profiles indicated a narrower stable operating region with increased background pressure. Experimental observations of the thruster operation indicated that increasing the facility background pressure shifted the ionization and acceleration zones upstream towards the thruster's anode. Future tests of the HiVHAc thruster are planned at background pressure conditions that are expected to be two to three times lower than what was achieved during this test campaign. These tests will not only assess the impact of reduced facility background pressure on thruster performance, voltage-current characteristics, and plume properties; but will also attempt to quantify the magnitude of the ionization and acceleration zones upstream shifting as a function of increased background pressure.

Description of background data in the SKB database GEOTAB. Version 2

International Nuclear Information System (INIS)

Eriksson, E.; Sehlstedt, S.

1991-03-01

During the research and development program performed by SKB for the final disposal of spent nuclear fuel, a large quantity of geoscientific data was collected. Most of this data was stored in a database called Geotab. The data is organized into eight groups as follows: Background information; Geological data; Borehole geophysical measurements; Ground surface geophysical measurements; Hydrogeological and meteorological data; Hydrochemical data; Petrophysical measurements and Tracer tests. Except for the case of borehole geophysical data, ground surface geophysical data and petrophysical data, described in the same report, the data in each group is described in a separate SKB report. The present report describes data within the Background data group. This data provides information on the location of areas studied, borehole positions and also some drilling information. Data is normally collected on forms or as notes and this is then stored into the database. The background data group, called BACKGROUND, is divided into several subgroups: BGAREA area background data; BGDRILL drilling information; BGDRILLP drill penetration data; BGHOLE borehole information; BGTABLES number of rows in a table and BGTOLR data table tolerance. A method consist of one or several data tables. In each chapter a method and its data tables are described. (authors)

An ultralow background germanium gamma-ray spectrometer

International Nuclear Information System (INIS)

Reeves, R.H.; Brodzinski, R.L.; Hensley, W.K.; Ryge, P.

1984-01-01

The monitoring of minimum detectable activity is becoming increasingly important as environmental concerns and regulations require more sensitive measurement of the radioactivity levels in the workplace and the home. In measuring this activity, however, the background becomes one of the limiting factors. Anticoincidence systems utilizing both NaI(T1) and plastic scintillators have proven effective in reducing some components of the background, but radiocontaminants in the various regions of these systems have limited their effectiveness, and their cost is often prohibitive. In order to obtain a genuinely low background detector system, all components must be free of detectable radioactivity, and the cosmic ray produced contribution must be significantly reduced. Current efforts by the authors to measure the double beta decay of Germanium 76 as predicted by Grand Unified Theories have resulted in the development of a high resolution germanium diode gamma spectrometer with an exceptionally low background. This paper describes the development of this system, outlines the configuration and operation of its preamplifier, linear amplifier, analog-to-digital converter, 4096-channel analyzer, shielding consisting of lead-sandwiched plastic scintillators wrapped in cadmium foil, photomultiplier, and its pulse generator and discriminator, and then discusses how the system can be utilized to significantly reduce the background in high resolution photon spectrometers at only moderate cost

Measles vaccination coverage in high-incidence areas of the ...

African Journals Online (AJOL)

including cold-chain maintenance.[5] ... Methods. Households were consecutively sampled in high-incidence areas identified using measles epidemic surveillance data. ... ratio in under-5s was 6.9/1 000 (Department of Health, Provincial.

Lepton-photon interactions in external background fields

Energy Technology Data Exchange (ETDEWEB)

Akal, Ibrahim [Theory Group, Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, D-22607 Hamburg (Germany); Moortgat-Pick, Gudrid [II. Institute for Theoretical Physics, University of Hamburg, Luruper Chaussee 149, D-22761 Hamburg (Germany)

2016-07-01

We investigate lepton-photon interactions in a class of generalized external background fields with periodic plane-wave character. Considering the full interaction with the background, S-matrix elements are calculated exactly. We apply those general expressions to interaction schemes like Compton scattering in specific field configurations, as for instance provided in modern laser facilities, or in high intense regions of future linear colliders. Results are extended to the case of frontal colliding high-energy field photons with leptons such that new insights beyond the usual soft terms become accessible.

Large-area high-power VCSEL pump arrays optimized for high-energy lasers

Science.gov (United States)

Wang, Chad; Geske, Jonathan; Garrett, Henry; Cardellino, Terri; Talantov, Fedor; Berdin, Glen; Millenheft, David; Renner, Daniel; Klemer, Daniel

2012-06-01

Practical, large-area, high-power diode pumps for one micron (Nd, Yb) as well as eye-safer wavelengths (Er, Tm, Ho) are critical to the success of any high energy diode pumped solid state laser. Diode efficiency, brightness, availability and cost will determine how realizable a fielded high energy diode pumped solid state laser will be. 2-D Vertical-Cavity Surface-Emitting Laser (VCSEL) arrays are uniquely positioned to meet these requirements because of their unique properties, such as low divergence circular output beams, reduced wavelength drift with temperature, scalability to large 2-D arrays through low-cost and high-volume semiconductor photolithographic processes, high reliability, no catastrophic optical damage failure, and radiation and vacuum operation tolerance. Data will be presented on the status of FLIR-EOC's VCSEL pump arrays. Analysis of the key aspects of electrical, thermal and mechanical design that are critical to the design of a VCSEL pump array to achieve high power efficient array performance will be presented.

Partition function for a singular background

International Nuclear Information System (INIS)

McKenzie-Smith, J.J.; Naylor, W.

2005-01-01

We present a method for evaluating the partition function in a varying external field. Specifically, we look at the case of a non-interacting, charged, massive scalar field at finite temperature with an associated chemical potential in the background of a delta-function potential. Whilst we present a general method, valid at all temperatures, we only give the result for the leading order term in the high temperature limit. Although the derivative expansion breaks down for inhomogeneous backgrounds we are able to obtain the high temperature expansion, as well as an analytic expression for the zero point energy, by way of a different approximation scheme, which we call the local Born approximation (LBA)

Partition function for a singular background

Energy Technology Data Exchange (ETDEWEB)

McKenzie-Smith, J.J. [Financial Risk Management Ltd, 15 Adam Street, London WC2N 6AH (United Kingdom)]. E-mail: julian.mckenzie-smith@frmhedge.com; Naylor, W. [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)]. E-mail: naylor@yukawa.kyoto-u.ac.jp

2005-03-17

We present a method for evaluating the partition function in a varying external field. Specifically, we look at the case of a non-interacting, charged, massive scalar field at finite temperature with an associated chemical potential in the background of a delta-function potential. Whilst we present a general method, valid at all temperatures, we only give the result for the leading order term in the high temperature limit. Although the derivative expansion breaks down for inhomogeneous backgrounds we are able to obtain the high temperature expansion, as well as an analytic expression for the zero point energy, by way of a different approximation scheme, which we call the local Born approximation (LBA)

Interaction of Socio-Demographic Background Variables with Inter ...

African Journals Online (AJOL)

Interaction of Socio-Demographic Background Variables with Inter-Spousal Communication Among Married Couples in Alimosho Local Government Area of Lagos State, Nigeria. ... marriage will increase from 20-24years to 25-29years due to the number of years of couple's educational pursuit in Lagos state of Nigeria.

ADAPTIVE BACKGROUND DENGAN METODE GAUSSIAN MIXTURE MODELS UNTUK REAL-TIME TRACKING

Directory of Open Access Journals (Sweden)

Silvia Rostianingsih

2008-01-01

Full Text Available Nowadays, motion tracking application is widely used for many purposes, such as detecting traffic jam and counting how many people enter a supermarket or a mall. A method to separate background and the tracked object is required for motion tracking. It will not be hard to develop the application if the tracking is performed on a static background, but it will be difficult if the tracked object is at a place with a non-static background, because the changing part of the background can be recognized as a tracking area. In order to handle the problem an application can be made to separate background where that separation can adapt to change that occur. This application is made to produce adaptive background using Gaussian Mixture Models (GMM as its method. GMM method clustered the input pixel data with pixel color value as it’s basic. After the cluster formed, dominant distributions are choosen as background distributions. This application is made by using Microsoft Visual C 6.0. The result of this research shows that GMM algorithm could made adaptive background satisfactory. This proofed by the result of the tests that succeed at all condition given. This application can be developed so the tracking process integrated in adaptive background maker process. Abstract in Bahasa Indonesia : Saat ini, aplikasi motion tracking digunakan secara luas untuk banyak tujuan, seperti mendeteksi kemacetan dan menghitung berapa banyak orang yang masuk ke sebuah supermarket atau sebuah mall. Sebuah metode untuk memisahkan antara background dan obyek yang di-track dibutuhkan untuk melakukan motion tracking. Membuat aplikasi tracking pada background yang statis bukanlah hal yang sulit, namun apabila tracking dilakukan pada background yang tidak statis akan lebih sulit, dikarenakan perubahan background dapat dikenali sebagai area tracking. Untuk mengatasi masalah tersebut, dapat dibuat suatu aplikasi untuk memisahkan background dimana aplikasi tersebut dapat

Topology of microwave background fluctuations - Theory

Science.gov (United States)

Gott, J. Richard, III; Park, Changbom; Bies, William E.; Bennett, David P.; Juszkiewicz, Roman

1990-01-01

Topological measures are used to characterize the microwave background temperature fluctuations produced by 'standard' scenarios (Gaussian) and by cosmic strings (non-Gaussian). Three topological quantities: total area of the excursion regions, total length, and total curvature (genus) of the isotemperature contours, are studied for simulated Gaussian microwave background anisotropy maps and then compared with those of the non-Gaussian anisotropy pattern produced by cosmic strings. In general, the temperature gradient field shows the non-Gaussian behavior of the string map more distinctively than the temperature field for all topology measures. The total contour length and the genus are found to be more sensitive to the existence of a stringy pattern than the usual temperature histogram. Situations when instrumental noise is superposed on the map, are considered to find the critical signal-to-noise ratio for which strings can be detected.

High speed fiber optics local area networks: Design and implementation

Science.gov (United States)

Tobagi, Fouad A.

1988-01-01

The design of high speed local area networks (HSLAN) for communication among distributed devices requires solving problems in three areas: (1) the network medium and its topology; (2) the medium access control; and (3) the network interface. Considerable progress has been made in all areas. Accomplishments are divided into two groups according to their theoretical or experimental nature. A brief summary is given in Section 2, including references to papers which appeared in the literature, as well as to Ph.D. dissertations and technical reports published at Stanford University.

High surface area carbon and process for its production

Energy Technology Data Exchange (ETDEWEB)

Romanos, Jimmy; Burress, Jacob; Pfeifer, Peter; Rash, Tyler; Shah, Parag; Suppes, Galen

2016-12-13

Activated carbon materials and methods of producing and using activated carbon materials are provided. In particular, biomass-derived activated carbon materials and processes of producing the activated carbon materials with prespecified surface areas and pore size distributions are provided. Activated carbon materials with preselected high specific surface areas, porosities, sub-nm (<1 nm) pore volumes, and supra-nm (1-5 nm) pore volumes may be achieved by controlling the degree of carbon consumption and metallic potassium intercalation into the carbon lattice during the activation process.

Demonstration of Cosmic Microwave Background Delensing Using the Cosmic Infrared Background.

Science.gov (United States)

Larsen, Patricia; Challinor, Anthony; Sherwin, Blake D; Mak, Daisy

2016-10-07

Delensing is an increasingly important technique to reverse the gravitational lensing of the cosmic microwave background (CMB) and thus reveal primordial signals the lensing may obscure. We present a first demonstration of delensing on Planck temperature maps using the cosmic infrared background (CIB). Reversing the lensing deflections in Planck CMB temperature maps using a linear combination of the 545 and 857 GHz maps as a lensing tracer, we find that the lensing effects in the temperature power spectrum are reduced in a manner consistent with theoretical expectations. In particular, the characteristic sharpening of the acoustic peaks of the temperature power spectrum resulting from successful delensing is detected at a significance of 16σ, with an amplitude of A_{delens}=1.12±0.07 relative to the expected value of unity. This first demonstration on data of CIB delensing, and of delensing techniques in general, is significant because lensing removal will soon be essential for achieving high-precision constraints on inflationary B-mode polarization.

A highly attennuative zone beneath the Tokyo Metropolitan area.

Science.gov (United States)

Panayotopoulos, Y.; Hirata, N.; Sakai, S.; Nakagawa, S.; Kasahara, K.

2014-12-01

The intensities of seismic waves observed at the dense seismic array of the Tokyo Metropolitan Seismic Observation network (MeSO-net) inside the Kanto basin, display unusual distribution patterns. In several occasions, the highest intensities are not observed in the area above an earthquakes hypocenter but appear sifted more than 20 km away. In order to understand the source of this unusual intensity distribution pattern, it is crucial to understand how the waves attenuate before they reach the surface. The attenuation of seismic waves along their path is represented by the t∗ attenuation operator that can be obtained by fitting the observed seismic wave spectrum to a theoretical spectrum using an ω2 model. In order to create a high quality dataset, only 1449 earthquakes that are recorded with intensity greater than 0 in the Japan Meteorological Agency (JMA) intensity scale are selected from the JMA unified earthquake list from April 1st 2008 to October 2nd 2013. A grid search method is applied to determine the t∗ values by matching the observed and theoretical spectra. The t∗ data where then inverted to estimate a 3D Q structure with grid points set at a 10 km spacing. We implemented the 3D velocity model estimated by Nakagawa et al., 2012 and in addition we set the initial Q values at 100 for the 0 km grids and to 400 for the grids below them. The obtained model suggests average Q values of 50˜100 inside the Kanto basin. Furthermore, a low Q zone is observed in the area where the Philippine Sea plate meets the upper part of the Pacific sea plate. This area is located at approximately 40 km depth, beneath the north-east Tokyo and west Chiba prefectures and is represented by Q values Earthquakes occurring on the Pacific plate pass through this low Q area inside the Philippine sea plate and are attenuated significantly. The estimated attenuation distribution at the MeSO-net station for these earthquakes implementing our 3D Q model greatly coincides with the

Background-Modeling-Based Adaptive Prediction for Surveillance Video Coding.

Science.gov (United States)

Zhang, Xianguo; Huang, Tiejun; Tian, Yonghong; Gao, Wen

2014-02-01

The exponential growth of surveillance videos presents an unprecedented challenge for high-efficiency surveillance video coding technology. Compared with the existing coding standards that were basically developed for generic videos, surveillance video coding should be designed to make the best use of the special characteristics of surveillance videos (e.g., relative static background). To do so, this paper first conducts two analyses on how to improve the background and foreground prediction efficiencies in surveillance video coding. Following the analysis results, we propose a background-modeling-based adaptive prediction (BMAP) method. In this method, all blocks to be encoded are firstly classified into three categories. Then, according to the category of each block, two novel inter predictions are selectively utilized, namely, the background reference prediction (BRP) that uses the background modeled from the original input frames as the long-term reference and the background difference prediction (BDP) that predicts the current data in the background difference domain. For background blocks, the BRP can effectively improve the prediction efficiency using the higher quality background as the reference; whereas for foreground-background-hybrid blocks, the BDP can provide a better reference after subtracting its background pixels. Experimental results show that the BMAP can achieve at least twice the compression ratio on surveillance videos as AVC (MPEG-4 Advanced Video Coding) high profile, yet with a slightly additional encoding complexity. Moreover, for the foreground coding performance, which is crucial to the subjective quality of moving objects in surveillance videos, BMAP also obtains remarkable gains over several state-of-the-art methods.

Status of the Simbol-X Background Simulation Activities

Science.gov (United States)

Tenzer, C.; Briel, U.; Bulgarelli, A.; Chipaux, R.; Claret, A.; Cusumano, G.; Dell'Orto, E.; Fioretti, V.; Foschini, L.; Hauf, S.; Kendziorra, E.; Kuster, M.; Laurent, P.; Tiengo, A.

2009-05-01

The Simbol-X background simulation group is working towards a simulation based background and mass model which can be used before and during the mission. Using the Geant4 toolkit, a Monte-Carlo code to simulate the detector background of the Simbol-X focal plane instrument has been developed with the aim to optimize the design of the instrument. Achieving an overall low instrument background has direct impact on the sensitivity of Simbol-X and thus will be crucial for the success of the mission. We present results of recent simulation studies concerning the shielding of the detectors with respect to the diffuse cosmic hard X-ray background and to the cosmic-ray proton induced background. Besides estimates of the level and spectral shape of the remaining background expected in the low and high energy detector, also anti-coincidence rates and resulting detector dead time predictions are discussed.

The challenge of building large area, high precision small-strip Thin Gap Trigger Chambers for the upgrade of the ATLAS experiment

CERN Document Server

Maleev, Victor; The ATLAS collaboration

2015-01-01

The current innermost stations of the ATLAS muon endcap system must be upgraded in 2018 and 2019 to retain the good precision tracking and trigger capabilities in the high background environment expected with the upcoming luminosity increase of the LHC. Large area small-strip Thin Gap Chambers (sTGC) up to 2 m2 in size and totaling an active area of 1200 m2 will be employed for fast and precise triggering. The precision reconstruction of tracks requires a spatial resolution of about 100 μm to allow the Level-1 trigger track segments to be reconstructed with an angular resolution of 1mrad. The upgraded detector will consist of eight layers each of Micromegas and sTGC’s detectors together forming the ATLAS New Small Wheels. The position of each strip must be known with an accuracy of 30 µm along the precision coordinate and 80 µm along the beam. On such large area detectors, the mechanical precision is a key point and then must be controlled and monitored all along the process of construction and integrati...

The Challenge of Building Large Area, High Precision Small-Strip Thin Gap Trigger Chambers for the Upgrade of the ATLAS Experiment

CERN Document Server

Maleev, Victor; The ATLAS collaboration

2015-01-01

The current innermost stations of the ATLAS muon end-cap system must be upgraded in 2018 and 2019 to retain the good precision tracking and trigger capabilities in the high background environment expected with the upcoming luminosity increase of the LHC. Large area small-strip Thin Gap Chambers (sTGC) up to 2 $m^2$ in size and totaling an active area of 1200 $m^2$ will be employed for fast and precise triggering. The precision reconstruction of tracks requires a spatial resolution of about 100 $\\mu m$ while the Level-1 trigger track segments need to be reconstructed with an angular resolution of 1 mrad. The upgraded detector will consist of eight layers each of Micromegas and sTGC’s detectors together forming the ATLAS New Small Wheels. The position of each strip must be known with an accuracy of 40 $\\mu m$ along the precision coordinate and 80 $\\mu m$ along the beam. On such large area detectors, the mechanical precision is a key point and then must be controlled and monitored all along the process of cons...

GALAXY COUNTS ON THE COSMIC MICROWAVE BACKGROUND COLD SPOT

International Nuclear Information System (INIS)

Granett, Benjamin R.; Szapudi, Istvan; Neyrinck, Mark C.

2010-01-01

The cold spot on the cosmic microwave background (CMB) could arise due to a supervoid at low redshift through the integrated Sachs-Wolfe effect. We imaged the region with MegaCam on the Canada-France-Hawaii Telescope and present galaxy counts in photometric redshift bins. We rule out the existence of a 100 Mpc radius spherical supervoid with underdensity δ = -0.3 at 0.5 < z < 0.9 at high significance. The data are consistent with an underdensity at low redshift, but the fluctuations are within the range of cosmic variance and the low-density areas are not contiguous on the sky. Thus, we find no strong evidence for a supervoid. We cannot resolve voids smaller than a 50 Mpc radius; however, these can only make a minor contribution to the CMB temperature decrement.

Effect of background noise on neuronal coding of interaural level difference cues in rat inferior colliculus.

Science.gov (United States)

Mokri, Yasamin; Worland, Kate; Ford, Mark; Rajan, Ramesh

2015-07-01

Humans can accurately localize sounds even in unfavourable signal-to-noise conditions. To investigate the neural mechanisms underlying this, we studied the effect of background wide-band noise on neural sensitivity to variations in interaural level difference (ILD), the predominant cue for sound localization in azimuth for high-frequency sounds, at the characteristic frequency of cells in rat inferior colliculus (IC). Binaural noise at high levels generally resulted in suppression of responses (55.8%), but at lower levels resulted in enhancement (34.8%) as well as suppression (30.3%). When recording conditions permitted, we then examined if any binaural noise effects were related to selective noise effects at each of the two ears, which we interpreted in light of well-known differences in input type (excitation and inhibition) from each ear shaping particular forms of ILD sensitivity in the IC. At high signal-to-noise ratios (SNR), in most ILD functions (41%), the effect of background noise appeared to be due to effects on inputs from both ears, while for a large percentage (35.8%) appeared to be accounted for by effects on excitatory input. However, as SNR decreased, change in excitation became the dominant contributor to the change due to binaural background noise (63.6%). These novel findings shed light on the IC neural mechanisms for sound localization in the presence of continuous background noise. They also suggest that some effects of background noise on encoding of sound location reported to be emergent in upstream auditory areas can also be observed at the level of the midbrain. © 2015 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Geological survey by high resolution electrical survey on granite areas

International Nuclear Information System (INIS)

Sugimoto, Yoshihiro; Yamada, Naoyuki

2002-03-01

As an Integral part of the geological survey in 'The study of the regions ground water flow system' that we are carrying out with Tono Geoscience Center, we proved the relation between the uncontinuation structure such as lineament in the base rock and resistivity structure (resistivity distribution), for the purpose of that confirms the efficacy of the high resolution electrical survey as geological survey, we carried out high resolution electrical survey on granite area. We obtained the following result, by the comparison of resistivity distribution with established geological survey, lineament analysis and investigative drilling. 1. The resistivity structure of this survey area is almost able to classify it into the following four range. 1) the low resistivity range of 50-800 Ωm, 2) The resistivity range like the middle of 200-2000 Ωm, 3) The high resistivity range of 2000 Ωm over, 4) The low resistivity range of depth of the survey line 400-550 section. 2. The low resistivity range of 4) that correspond with the established geological data is not admitted. 3. It was confirmed that resistivity structure almost correspond to geological structure by the comparison with the established data. 4. The small-scale low resistivity area is admitted in the point equivalent to the lineament position of established. 5. We carried out it with the simulation method about the low resistivity range of 4). As a result, it understood that it has the possibility that the narrow ratio low resistivity area is shown as the wide ratio resistivity range in the analysis section. In the survey in this time, it is conceivable that the resistivity distribution with the possibility of the unhomogeneous and uncontinuation structure of the base rock is being shown conspicuously, the efficacy of the high resolution resistivity survey as geological survey on granite was shown. (author)

Source origin of trace elements in PM from regional background, urban and industrial sites of Spain

Science.gov (United States)

Querol, X.; Viana, M.; Alastuey, A.; Amato, F.; Moreno, T.; Castillo, S.; Pey, J.; de la Rosa, J.; Sánchez de la Campa, A.; Artíñano, B.; Salvador, P.; García Dos Santos, S.; Fernández-Patier, R.; Moreno-Grau, S.; Negral, L.; Minguillón, M. C.; Monfort, E.; Gil, J. I.; Inza, A.; Ortega, L. A.; Santamaría, J. M.; Zabalza, J.

Despite their significant role in source apportionment analysis, studies dedicated to the identification of tracer elements of emission sources of atmospheric particulate matter based on air quality data are relatively scarce. The studies describing tracer elements of specific sources currently available in the literature mostly focus on emissions from traffic or large-scale combustion processes (e.g. power plants), but not on specific industrial processes. Furthermore, marker elements are not usually determined at receptor sites, but during emission. In our study, trace element concentrations in PM 10 and PM 2.5 were determined at 33 monitoring stations in Spain throughout the period 1995-2006. Industrial emissions from different forms of metallurgy (steel, stainless steel, copper, zinc), ceramic and petrochemical industries were evaluated. Results obtained at sites with no significant industrial development allowed us to define usual concentration ranges for a number of trace elements in rural and urban background environments. At industrial and traffic hotspots, average trace metal concentrations were highest, exceeding rural background levels by even one order of magnitude in the cases of Cr, Mn, Cu, Zn, As, Sn, W, V, Ni, Cs and Pb. Steel production emissions were linked to high levels of Cr, Mn, Ni, Zn, Mo, Cd, Se and Sn (and probably Pb). Copper metallurgy areas showed high levels of As, Bi, Ga and Cu. Zinc metallurgy was characterised by high levels of Zn and Cd. Glazed ceramic production areas were linked to high levels of Zn, As, Se, Zr, Cs, Tl, Li, Co and Pb. High levels of Ni and V (in association) were tracers of petrochemical plants and/or fuel-oil combustion. At one site under the influence of heavy vessel traffic these elements could be considered tracers (although not exclusively) of shipping emissions. Levels of Zn-Ba and Cu-Sb were relatively high in urban areas when compared with industrialised regions due to tyre and brake abrasion, respectively.

Effect of high gamma background on neutron sensitivity of fission detectors

International Nuclear Information System (INIS)

Balagi, V.; Prasad, K.R.; Kataria, S.K.

2004-01-01

Tests were performed on two parallel plate and two cylindrical fission detectors in pulse and dc mode. The effect of gamma background on neutron sensitivity was studied in thermal neutron flux from 30 nv to 60 nv over which gamma field intensity ranging from 230 kR/h to 3.7 MR/h was superposed. In the case of one of the parallel plate detectors the fall in neutron sensitivity was observed to be 3.7% at 1 MR/h and negligible below 1 MR/h. In the case of one of the cylindrical counters the fall in neutron sensitivity was negligible below 500 kR/h and 37% at 1 MR/h. The data was used to derive the design parameters for a wide range fission detector to be procured for PFBR instrumentation for operation at 600 degC and gamma background of 1 MR/h. (author)

75 FR 52780 - Designation of Nine Counties as High Intensity Drug Trafficking Areas

Science.gov (United States)

2010-08-27

... EXECUTIVE OFFICE OF THE PRESIDENT Office of National Drug Control Policy Designation of Nine Counties as High Intensity Drug Trafficking Areas ACTION: Notice. SUMMARY: The Director of the Office of National Drug Control Policy designated nine additional counties as High Drug Trafficking Areas pursuant to...

75 FR 21368 - Designation of Five Counties as High Intensity Drug Trafficking Areas

Science.gov (United States)

2010-04-23

... EXECUTIVE OFFICE OF THE PRESIDENT Office of National Drug Control Policy Designation of Five Counties as High Intensity Drug Trafficking Areas ACTION: Notice. SUMMARY: The Director of the Office of National Drug Control Policy designated five additional counties as High Drug Trafficking Areas pursuant to...

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)

Highly Flexible and High-Performance Complementary Inverters of Large-Area Transition Metal Dichalcogenide Monolayers

KAUST Repository

Pu, Jiang; Funahashi, Kazuma; Chen, Chang-Hsiao; Li, Ming-yang; Li, Lain-Jong; Takenobu, Taishi

2016-01-01

Complementary inverters constructed from large-area monolayers of WSe2 and MoS2 achieve excellent logic swings and yield an extremely high gain, large total noise margin, low power consumption, and good switching speed. Moreover, the WSe2

Judgments of aircraft noise in a traffic noise background

Science.gov (United States)

Powell, C. A.; Rice, C. G.

1975-01-01

An investigation was conducted to determine subjective response to aircraft noise in different road traffic backgrounds. In addition, two laboratory techniques for presenting the aircraft noise with the background noise were evaluated. For one technique, the background noise was continuous over an entire test session; for the other, the background noise level was changed with each aircraft noise during a session. Subjective response to aircraft noise was found to decrease with increasing background noise level, for a range of typical indoor noise levels. Subjective response was found to be highly correlated with the Noise Pollution Level (NPL) measurement scale.

A background free double beta decay experiment

International Nuclear Information System (INIS)

Giomataris, I

2011-01-01

We present a new detection scheme for rejecting backgrounds in neutrino-less double beta decay experiments. It relies on the detection of Cherenkov light emitted by electrons in the MeV region. The momentum threshold is tuned to reach a good discrimination between background and good events. We consider many detector concepts and a range of target materials. The most promising is the high-pressure 136 Xe emitter where the required energy threshold is easily adjusted. Combination of this concept and a high pressure Time Projection Chamber could provide an optimal solution. A simple and low cost effective solution is the use of the Spherical Proportional Counter that provides, using a single read-out channel, two delayed signals from ionization and Cherenkov light. In solid-state double beta decay emitters, because of its higher density, the considered process is out of energy range. An escape will be the fabrication of double decay emitters having lower density by using for instance the aerogel technique. It is surprising that a technology used for particle identification in high-energy physics becomes a powerful tool for rejecting backgrounds in such low-energy experiments.

Characterizing the spatial variability of local and background concentration signals for air pollution at the neighbourhood scale

Science.gov (United States)

Shairsingh, Kerolyn K.; Jeong, Cheol-Heon; Wang, Jonathan M.; Evans, Greg J.

2018-06-01

Vehicle emissions represent a major source of air pollution in urban districts, producing highly variable concentrations of some pollutants within cities. The main goal of this study was to identify a deconvolving method so as to characterize variability in local, neighbourhood and regional background concentration signals. This method was validated by examining how traffic-related and non-traffic-related sources influenced the different signals. Sampling with a mobile monitoring platform was conducted across the Greater Toronto Area over a seven-day period during summer 2015. This mobile monitoring platform was equipped with instruments for measuring a wide range of pollutants at time resolutions of 1 s (ultrafine particles, black carbon) to 20 s (nitric oxide, nitrogen oxides). The monitored neighbourhoods were selected based on their land use categories (e.g. industrial, commercial, parks and residential areas). The high time-resolution data allowed pollutant concentrations to be separated into signals representing background and local concentrations. The background signals were determined using a spline of minimums; local signals were derived by subtracting the background concentration from the total concentration. Our study showed that temporal scales of 500 s and 2400 s were associated with the neighbourhood and regional background signals respectively. The percent contribution of the pollutant concentration that was attributed to local signals was highest for nitric oxide (NO) (37-95%) and lowest for ultrafine particles (9-58%); the ultrafine particles were predominantly regional (32-87%) in origin on these days. Local concentrations showed stronger associations than total concentrations with traffic intensity in a 100 m buffer (ρ:0.21-0.44). The neighbourhood scale signal also showed stronger associations with industrial facilities than the total concentrations. Given that the signals show stronger associations with different land use suggests that

Novel strategies lead to pre-elimination of malaria in previously high-risk areas in Suriname, South America

Directory of Open Access Journals (Sweden)

Hiwat Hélène

2012-01-01

Full Text Available Abstract Background Suriname was a high malaria risk country before the introduction of a new five-year malaria control program in 2005, the Medical Mission Malaria Programme (MM-MP. Malaria was endemic in the forested interior, where especially the stabile village communities were affected. Case description The interventions of the MM-MP included new strategies for prevention, vector control, case management, behavioral change communication (BCC/information, education and communication (IEC, and strengthening of the health system (surveillance, monitoring and evaluation and epidemic detection system. After a slow first year with non-satisfying scores for the performance indicators, the MM-MP truly engaged in its intervention activities in 2006 and kept its performance up until the end of 2009. A total of 69,994 long-lasting insecticide-treated nets were distributed and more than 15,000 nets re-impregnated. In high-risk areas, this was complemented with residual spraying of insecticides. Over 10,000 people were screened with active case detection in outbreak and high-risk areas. Additional notification points were established and the national health system was strengthened. Discussion and evaluation In the current paper, the MM-MP is evaluated both on account of the targets established within the programme and on account of its impact on the malaria situation in Suriname. Malaria vector populations, monitored in sentinel sites, collapsed after 2006 and concurrently the number of national malaria cases decreased from 8,618 in 2005 to 1,509 in 2009. Malaria transmission risk shifted from the stabile village communities to the mobile gold mining communities, especially those along the French Guiana border. Conclusions The novel strategies for malaria control introduced in Suriname within the MM-MP have led to a significant decrease in the national malaria burden. The challenge is to further reduce malaria using the available strategies as

Altered intraoperative cerebrovascular reactivity in brain areas of high-grade glioma recurrence.

Science.gov (United States)

Fierstra, Jorn; van Niftrik, Bas; Piccirelli, Marco; Burkhardt, Jan Karl; Pangalu, Athina; Kocian, Roman; Valavanis, Antonios; Weller, Michael; Regli, Luca; Bozinov, Oliver

2016-07-01

Current MRI sequences are limited in identifying brain areas at risk for high grade glioma recurrence. We employed intraoperative 3-Tesla functional MRI to assess cerebrovascular reactivity (CVR) after high-grade glioma resection and analyzed regional CVR responses in areas of tumor recurrence on clinical follow-up imaging. Five subjects with high-grade glioma that underwent an intraoperative Blood Oxygen-Level Dependent (BOLD) MRI CVR examination and had a clinical follow-up of at least 18months were selected from a prospective database. For this study, location of tumor recurrence was spatially matched to the intraoperative imaging to assess CVR response in that particular area. CVR is defined as the percent BOLD signal change during repeated cycles of apnea. Of the 5 subjects (mean age 44, 2 females), 4 were diagnosed with a WHO grade III and 1 subject with a WHO grade IV glioma. Three subjects exhibited a tumor recurrence on clinical follow-up MRI (mean: 15months). BOLD CVR measured in the spatially matched area of tumor recurrence was on average 94% increased (range-32% to 183%) as compared to contralateral hemisphere CVR response, 1.50±0.81 versus 1.03±0.46 respectively (p=0.31). For this first analysis in a small cohort, we found altered intraoperative CVR in brain areas exhibiting high grade glioma recurrence on clinical follow-up imaging. Copyright © 2016 Elsevier Inc. All rights reserved.

Background radioactivity in sediments near Los Alamos, New Mexico

International Nuclear Information System (INIS)

McLin, Stephen G.

2004-01-01

River and reservoir sediments have been collected annually by Los Alamos National Laboratory since 1974 and 1979, respectively. These background samples are collected from five river stations and four reservoirs located throughout northern New Mexico and southern Colorado. Analyses include 3 H, 90 Sr, 137 Cs, total U, 238 Pu, 239,240 Pu, 241 Am, gross alpha, gross beta, and gross gamma radioactivity. Surprisingly, there are no federal or state regulatory standards in the USA that specify how to compute background radioactivity values on sediments. Hence, the sample median (or 0.50 quantile) is proposed for this background because it reflects central data tendency and is distribution-free. Estimates for the upper limit of background radioactivity on river and reservoir sediments are made for sampled analytes using the 0.95 quantile (two-tail). These analyses also show that seven of ten analytes from reservoir sediments are normally distributed, or are normally distributed after a logarithmic or square root transformation. However, only three of ten analytes from river sediments are similarly distributed. In addition, isotope ratios for 137 Cs/ 238 Pu, 137 Cs/ 239,240 Pu, and 239,240 Pu/ 238 Pu from reservoir sediments are independent of clay content, total organic carbon/specific surface area (TOC/SSA) and cation exchange capacity/specific surface area (CEC/SSA) ratios. These TOC/SSA and CEC/SSA ratios reflect sediment organic carbon and surface charge densities that are associated with radionuclide absorption, adsorption, and ion exchange reactions on clay mineral structures. These latter ratio values greatly exceed the availability of background radionuclides in the environment, and insure that measured background levels are a maximum. Since finer-grained reservoir sediments contain larger clay-sized fractions compared to coarser river sediments, they show higher background levels for most analytes. Furthermore, radioactivity values on reservoir sediments have

Soil dioxins levels at agriculture sites and natural preserve areas of Taiwan.

Science.gov (United States)

Jou, Jin-juh; Lin, Kae-Long; Chung, Jen-Chir; Liaw, Shu-Liang

2007-08-17

In this study, agriculture soil in Taiwan has been sampled and analyzed to determine the background level of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DF) in the agricultural and nature preserve areas. Another objective is to investigate relationship between soil characteristics and air deposition in Taiwan. The results indicate that in nature preserve areas the topsoil shows an extraordinary profile of PCDD/DF compared to that in the air deposition. The PCDD/DF levels of the low-contaminated agricultural soils are compatible with those of the nature preserves soils. However, in the highly-contaminated agricultural soils, there is an abrupt jump in their concentrations, 10-100 times higher. The overall I-TEQ values of the background topsoils range from 0.101 to 15.2 ng I-TEQ/kg. Near industrial/urban areas in Taiwan the PCDD/DF are slightly higher compared to those in the low concentration group. Typically, the PCDD/DF background values found in this survey fall in the 90% confidence interval and can thus, be deemed the background levels in Taiwan. Ninety-five percent of these data are below the European and American soil standard of 10 ng I-TEQ/kg d.w. The PCDD/DF profile with one neighborhood soil sample was shown no significant difference.

Listening to Students from Refugee Backgrounds: Lessons for Education Professionals

Science.gov (United States)

Mthethwa-Sommers, Shirley; Kisiara, Otieno

2015-01-01

This article is based on a study that examined how students from refugee backgrounds cope with victimization and bullying in three urban high schools in the United States. Qualitative methods of data collection and analysis were employed. Twelve high school students from refugee backgrounds participated in the study, which involved focus group…

Beamstop-based low-background ptychography to image weakly scattering objects

Energy Technology Data Exchange (ETDEWEB)

Reinhardt, Juliane, E-mail: juliane.reinhardt@desy.de [Deutsches Elektronen-Synchrotron DESY, D-22607 Hamburg (Germany); Hoppe, Robert [Institute of Structural Physics, Technische Universität Dresden, D-01062 Dresden (Germany); Hofmann, Georg [Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, D-76131 Karlsruhe (Germany); Damsgaard, Christian D. [Center for Electron Nanoscopy and Department of Physics, Technical University of Denmark, DK-2800 Lyngby (Denmark); Patommel, Jens; Baumbach, Christoph [Institute of Structural Physics, Technische Universität Dresden, D-01062 Dresden (Germany); Baier, Sina; Rochet, Amélie; Grunwaldt, Jan-Dierk [Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, D-76131 Karlsruhe (Germany); Falkenberg, Gerald [Deutsches Elektronen-Synchrotron DESY, D-22607 Hamburg (Germany); Schroer, Christian G. [Deutsches Elektronen-Synchrotron DESY, D-22607 Hamburg (Germany); Department Physik, Universität Hamburg, Luruper Chaussee 149, D-22761 Hamburg (Germany)

2017-02-15

In recent years, X-ray ptychography has been established as a valuable tool for high-resolution imaging. Nevertheless, the spatial resolution and sensitivity in coherent diffraction imaging are limited by the signal that is detected over noise and over background scattering. Especially, coherent imaging of weakly scattering specimens suffers from incoherent background that is generated by the interaction of the central beam with matter along its propagation path in particular close to and inside of the detector. Common countermeasures entail evacuated flight tubes or detector-side beamstops, which improve the experimental setup in terms of background reduction or better coverage of high dynamic range in the diffraction patterns. Here, we discuss an alternative approach: we combine two ptychographic scans with and without beamstop and reconstruct them simultaneously taking advantage of the complementary information contained in the two scans. We experimentally demonstrate the potential of this scheme for hard X-ray ptychography by imaging a weakly scattering object composed of catalytic nanoparticles and provide the analysis of the signal-to-background ratio in the diffraction patterns. - Highlights: • An opaque beamstop far-upstream of the detector reduces background scattering. • Increased signal-to-background ratio in the diffraction patterns. • Simultaneous ptychographic reconstruction of two data sets with and without beamstop. • Result shows high spatial resolution of 13 nm of a weakly scattering catalyst sample. • High sensitivity to less than 10{sup 5} atoms.

Neotectonic movement feature in preselection area for high level radioactive waste repository

International Nuclear Information System (INIS)

Huang Xianfang; Gao Yang; He Jianguo; Li Jianzhong; Gao Honglei; Xu Guoqing

2010-01-01

Neotectonic activity intensity is an important criteria for evaluating high level radioactive waste repository. The guiding ideology, methods and application of neotectonic study are elaborated in the paper. According to comparison research between the south and north part of east Tianshan area, the south part of east Tianshan is regarded as relative stable or relative weak in neotectonic movement in Neogene period and was selected as preselection area for high level radioactive waste repository. (authors)

Spatial overlap between environmental policy instruments and areas of high conservation value in forest.

Science.gov (United States)

Sverdrup-Thygeson, Anne; Søgaard, Gunnhild; Rusch, Graciela M; Barton, David N

2014-01-01

In order to safeguard biodiversity in forest we need to know how forest policy instruments work. Here we use a nationwide network of 9400 plots in productive forest to analyze to what extent large-scale policy instruments, individually and together, target forest of high conservation value in Norway. We studied both instruments working through direct regulation; Strict Protection and Landscape Protection, and instruments working through management planning and voluntary schemes of forest certification; Wilderness Area and Mountain Forest. As forest of high conservation value (HCV-forest) we considered the extent of 12 Biodiversity Habitats and the extent of Old-Age Forest. We found that 22% of productive forest area contained Biodiversity Habitats. More than 70% of this area was not covered by any large-scale instruments. Mountain Forest covered 23%, while Strict Protection and Wilderness both covered 5% of the Biodiversity Habitat area. A total of 9% of productive forest area contained Old-Age Forest, and the relative coverage of the four instruments was similar as for Biodiversity Habitats. For all instruments, except Landscape Protection, the targeted areas contained significantly higher proportions of HCV-forest than areas not targeted by these instruments. Areas targeted by Strict Protection had higher proportions of HCV-forest than areas targeted by other instruments, except for areas targeted by Wilderness Area which showed similar proportions of Biodiversity Habitats. There was a substantial amount of spatial overlap between the policy tools, but no incremental conservation effect of overlapping instruments in terms of contributing to higher percentages of targeted HCV-forest. Our results reveal that although the current policy mix has an above average representation of forest of high conservation value, the targeting efficiency in terms of area overlap is limited. There is a need to improve forest conservation and a potential to cover this need by better

Influence of Cooling Rate in High-Temperature Area on Hardening of Deposited High-Cutting Chrome-Tungsten Metal

OpenAIRE

Malushin, N. N.; Valuev, Denis Viktorovich; Valueva, Anna Vladimirovna; Serikbol, A.; Borovikov, I. F.

2015-01-01

The authors study the influence of cooling rate in high-temperature area for thermal cycle of high-cutting chrome-tungsten metal weld deposit on the processes of carbide phase merging and austenite grain growth for the purpose of providing high hardness of deposited metal (HRC 64-66).

High level natural radiation areas with special regard to Ramsar

International Nuclear Information System (INIS)

Sohrabi, M.

1993-01-01

The studies of high level natural radiation areas (HLNRAs) around the world are of great importance for determination of risks due to long-term low-level whole body exposures of public. Many areas of the world possess HLNRAs the number of which depends on the criteria defined. Detailed radiological studies have been carried out in some HLNRAs the results of which have been reported at least in three international conferences. Among the HLNRAs, Ramsar has so far the highest level of natural radiation in some areas where radiological studies have been of concern. A program was established for Ramsar and its HLNRAs to study indoor and outdoor gamma exposures and external and internal doses of the inhabitants, 226 Ra content of public water supplies and hot springs, of food stuffs, etc., 222 Rn levels measured in 473 rooms of near 350 houses, 16 schools and 89 rooms and many locations of old and new Ramsar Hotels in different seasons, cytogenetic effects on inhabitants of Talesh Mahalleh, the highest radiation area, compared to that of a control area and radiological parameters of a house with a high potential for internal and external exposures of the inhabitants. It was concluded that the epidemiological studies in a number of countries did not show any evidence of increased health detriment in HLNRAs compared to control groups. In this paper, the conclusions drawn from studies in some HLNRAs around the world in particular Ramsar are discussed. (author). 20 refs, 2 figs, 1 tab

Electricity demand profile with high penetration of heat pumps in Nordic area

DEFF Research Database (Denmark)

Liu, Zhaoxi; Wu, Qiuwei; Nielsen, Arne Hejde

2013-01-01

This paper presents the heat pump (HP) demand profile with high HP penetration in the Nordic area in order to achieve the carbon neutrality power system. The calculation method in the European Standard EN14825 was used to estimate the HP electricity demand profile. The study results show...... there will be high power demand from HPs and the selection of supplemental heating for heat pumps has a big impact on the peak electrical power load of heating. The study in this paper gives an estimate of the scale of the electricity demand with high penetration of heat pumps in the Nordic area....

The slope-background for the near-peak regimen of photoemission spectra

Energy Technology Data Exchange (ETDEWEB)

Herrera-Gomez, A., E-mail: aherrera@qro.cinvestav.mx [CINVESTAV-Unidad Queretaro, Queretaro 76230 (Mexico); Bravo-Sanchez, M. [CINVESTAV-Unidad Queretaro, Queretaro 76230 (Mexico); Aguirre-Tostado, F.S. [Centro de Investigación en Materiales Avanzados, Chihuahua, Chihuahua 31109 (Mexico); Vazquez-Lepe, M.O. [Departamento de Ingeniería de Proyectos, Universidad de Guadalajara, Jalisco 44430 (Mexico)

2013-08-15

Highlights: •We propose a method that accounts for the change in the background slope of XPS data. •The slope-background can be derived from Tougaard–Sigmund's transport theory. •The total background is composed by Shirley–Sherwood and Tougaard type backgrounds. •The slope-background employs one parameter that can be related to REELS spectra. •The slope, in conjunction with the Shirley–Sherwood background, provides better fits. -- Abstract: Photoemission data typically exhibits a change on the intensity of the background between the two sides of the peaks. This step is usually very well reproduced by the Shirley–Sherwood background. Yet, the change on the slope of the background in the near-peak regime, although usually present, is not always as obvious to the eye. However, the intensity of the background signal associated with the evolution of its slope can be appreciable. The slope-background is designed to empirically reproduce the change on the slope. Resembling the non-iterative Shirley method, the proposed functional form relates the slope of the background to the integrated signal at higher electron kinetic energies. This form can be predicted under Tougaard–Sigmund's electron transport theory in the near-peak regime. To reproduce both the step and slope changes on the background, it is necessary to employ the slope-background in conjunction with the Shirley–Sherwood background under the active-background method. As it is shown for a series of materials, the application of the slope-background provides excellent fits, is transparent to the operator, and is much more independent of the fitting range than other background methods. The total area assessed through the combination of the slope and the Shirley–Sherwood backgrounds is larger than when only the Shirley–Sherwood background is employed, and smaller than when the Tougaard background is employed.

Ambient pressure dried tetrapropoxysilane-based silica aerogels with high specific surface area

Science.gov (United States)

Parale, Vinayak G.; Han, Wooje; Jung, Hae-Noo-Ree; Lee, Kyu-Yeon; Park, Hyung-Ho

2018-01-01

In the present paper, we report the synthesis of tetrapropoxysilane (TPOS)-based silica aerogels with high surface area and large pore volume. The silica aerogels were prepared by a two-step sol-gel process followed by surface modification via a simple ambient pressure drying approach. In order to minimize drying shrinkage and obtain hydrophobic aerogels, the surface of the alcogels was modified using trichloromethylsilane as a silylating agent. The effect of the sol-gel compositional parameters on the polymerization of aerogels prepared by TPOS, one of the precursors belonging to the Si(OR)4 family, was reported for the first time. The oxalic acid and NH4OH concentrations were adjusted to achieve good-quality aerogels with high surface area, low density, and high transparency. Controlling the hydrolysis and condensation reactions of the TPOS precursor turned out to be the most important factor to determine the pore characteristics of the aerogel. Highly transparent aerogels with high specific surface area (938 m2/g) and low density (0.047 g/cm3) could be obtained using an optimized TPOS/MeOH molar ratio with appropriate concentrations of oxalic acid and NH4OH.

Influence of Cooling Rate in High-Temperature Area on Hardening of Deposited High-Cutting Chrome-Tungsten Metal

International Nuclear Information System (INIS)

Malushin, N N; Valuev, D V; Valueva, A V; Serikbol, A; Borovikov, I F

2015-01-01

The authors study the influence of cooling rate in high-temperature area for thermal cycle of high-cutting chrome-tungsten metal weld deposit on the processes of carbide phase merging and austenite grain growth for the purpose of providing high hardness of deposited metal (HRC 64-66). (paper)

Aloe vera Derived Activated High-Surface-Area Carbon for Flexible and High-Energy Supercapacitors.

Science.gov (United States)

Karnan, M; Subramani, K; Sudhan, N; Ilayaraja, N; Sathish, M

2016-12-28

Materials which possess high specific capacitance in device configuration with low cost are essential for viable application in supercapacitors. Herein, a flexible high-energy supercapacitor device was fabricated using porous activated high-surface-area carbon derived from aloe leaf (Aloe vera) as a precursor. The A. vera derived activated carbon showed mesoporous nature with high specific surface area of ∼1890 m 2 /g. A high specific capacitance of 410 and 306 F/g was achieved in three-electrode and symmetric two-electrode system configurations in aqueous electrolyte, respectively. The fabricated all-solid-state device showed a high specific capacitance of 244 F/g with an energy density of 8.6 Wh/kg. In an ionic liquid electrolyte, the fabricated device showed a high specific capacitance of 126 F/g and a wide potential window up to 3 V, which results in a high energy density of 40 Wh/kg. Furthermore, it was observed that the activation temperature has significant role in the electrochemical performance, as the activated sample at 700 °C showed best activity than the samples activated at 600 and 800 °C. The electron microscopic images (FE-SEM and HR-TEM) confirmed the formation of pores by the chemical activation. A fabricated supercapacitor device in ionic liquid with 3 V could power up a red LED for 30 min upon charging for 20s. Also, it is shown that the operation voltage and capacitance of flexible all-solid-state symmetric supercapacitors fabricated using aloe-derived activated carbon could be easily tuned by series and parallel combinations. The performance of fabricated supercapacitor devices using A. vera derived activated carbon in all-solid-state and ionic liquid indicates their viable applications in flexible devices and energy storage.

Installation of a muon veto for low background gamma spectroscopy at the LBNL low-background facility

Energy Technology Data Exchange (ETDEWEB)

Thomas, K.J., E-mail: kjthomas@lbl.gov [Department of Nuclear Engineering, University of California, Berkeley, CA 94720 (United States); Nuclear Science Division, Lawrence Berkeley Laboratory, CA 94720 (United States); Norman, E.B. [Department of Nuclear Engineering, University of California, Berkeley, CA 94720 (United States); Nuclear Science Division, Lawrence Berkeley Laboratory, CA 94720 (United States); Smith, A.R.; Chan, Y.D. [Nuclear Science Division, Lawrence Berkeley Laboratory, CA 94720 (United States)

2013-10-01

An active veto system consisting of plastic scintillation panels was installed outside the Pb shielding of a 115% n-type HPGe detector in an effort to reduce background continuum generated by cosmic ray muons on the surface. The Low Background Facility at the Lawrence Berkeley National Laboratory performs low level assay (generally of primordial U, Th, K) of candidate construction materials for experiments that require a high level of radiopurity. The counting is performed in two facilities: one local surface site and a remote underground site of approximately 600 m.w.e. For the recently installed veto system at the surface location, the top scintillator panel has been in use for nearly 1 year and the full 3π anticoincidence shield was commissioned into normal counting operations in January 2013. The integrated background from 20 to 3600 keV is reduced overall by a factor of 8, where most of the energy spectrum above 100 keV achieves an overall reduction that varies from 8 to 10. A dramatic improvement of peak-to-background across the entire continuum is observed, greatly enhancing low-level peaks that would otherwise be obscured.

A novel method to remove GPR background noise based on the similarity of non-neighboring regions

Science.gov (United States)

Montiel-Zafra, V.; Canadas-Quesada, F. J.; Vera-Candeas, P.; Ruiz-Reyes, N.; Rey, J.; Martinez, J.

2017-09-01

Ground penetrating radar (GPR) is a non-destructive technique that has been widely used in many areas of research, such as landmine detection or subsurface anomalies, where it is required to locate targets embedded within a background medium. One of the major challenges in the research of GPR data remains the improvement of the image quality of stone materials by means of detection of true anisotropies since most of the errors are caused by an incorrect interpretation by the users. However, it is complicated due to the interference of the horizontal background noise, e.g., the air-ground interface, that reduces the high-resolution quality of radargrams. Thus, weak or deep anisotropies are often masked by this type of noise. In order to remove the background noise obtained by GPR, this work proposes a novel background removal method assuming that the horizontal noise shows repetitive two-dimensional regions along the movement of the GPR antenna. Specifically, the proposed method, based on the non-local similarity of regions over the distance, computes similarities between different regions of the same depth in order to identify most repetitive regions using a criterion to avoid closer regions. Evaluations are performed using a set of synthetic and real GPR data. Experimental results show that the proposed method obtains promising results compared to the classic background removal techniques and the most recently published background removal methods.

Influence of radiation damage on internal friction background

International Nuclear Information System (INIS)

Burbelo, R.M.; Grinik, Eh.U.; Paliokha, M.I.; Orlinskij, A.B.

1984-01-01

Influence of radiation damage on internal friction background in samples of polycrystalline nickel and iron irradiated by a fast neutron flux approximately 10 14 neutr/(cm 2 xs) at 350 deg C has been studied using the low-frequency unit of the reverse torsion pendulum type. It has been established experimentally that a high-temperature background of internal friction of iron and nickel samples decreases as accumulating radiation defects occurring under neutron irradiation. Assumptions on a possible mechanism of the effect have been proposed. Simple expression for the background magnitude evaluation has been suggested

The isotropic radio background revisited

Energy Technology Data Exchange (ETDEWEB)

Fornengo, Nicolao; Regis, Marco [Dipartimento di Fisica Teorica, Università di Torino, via P. Giuria 1, I–10125 Torino (Italy); Lineros, Roberto A. [Instituto de Física Corpuscular – CSIC/U. Valencia, Parc Científic, calle Catedrático José Beltrán, 2, E-46980 Paterna (Spain); Taoso, Marco, E-mail: fornengo@to.infn.it, E-mail: rlineros@ific.uv.es, E-mail: regis@to.infn.it, E-mail: taoso@cea.fr [Institut de Physique Théorique, CEA/Saclay, F-91191 Gif-sur-Yvette Cédex (France)

2014-04-01

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 emission is reasonable, extragalactic sources well below the current experimental threshold seem to account for the majority of the brightness of the extragalactic radio sky.

The isotropic radio background revisited

International Nuclear Information System (INIS)

Fornengo, Nicolao; Regis, Marco; Lineros, Roberto A.; 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 emission is reasonable, extragalactic sources well below the current experimental threshold seem to account for the majority of the brightness of the extragalactic radio sky

A new acoustic lens material for large area detectors in photoacoustic breast tomography

NARCIS (Netherlands)

Xia, W.; Piras, D.; van Hespen, Johannes C.G.; Steenbergen, Wiendelt; Manohar, Srirang

2013-01-01

Objectives We introduce a new acoustic lens material for photoacoustic tomography (PAT) to improve lateral resolution while possessing excellent acoustic acoustic impedance matching with tissue to minimize lens induced image artifacts. Background A large surface area detector due to its high

Nanoporous Ni with High Surface Area for Potential Hydrogen Storage Application.

Science.gov (United States)

Zhou, Xiaocao; Zhao, Haibo; Fu, Zhibing; Qu, Jing; Zhong, Minglong; Yang, Xi; Yi, Yong; Wang, Chaoyang

2018-06-01

Nanoporous metals with considerable specific surface areas and hierarchical pore structures exhibit promising applications in the field of hydrogen storage, electrocatalysis, and fuel cells. In this manuscript, a facile method is demonstrated for fabricating nanoporous Ni with a high surface area by using SiO₂ aerogel as a template, i.e., electroless plating of Ni into an SiO₂ aerogel template followed by removal of the template at moderate conditions. The effects of the prepared conditions, including the electroless plating time, temperature of the structure, and the magnetism of nanoporous Ni are investigated in detail. The resultant optimum nanoporous Ni with a special 3D flower-like structure exhibited a high specific surface area of about 120.5 m²/g. The special nanoporous Ni exhibited a promising prospect in the field of hydrogen storage, with a hydrogen capacity of 0.45 wt % on 4.5 MPa at room temperature.

The flip-over effect in pulsed laser deposition: Is it relevant at high background gas pressures?

International Nuclear Information System (INIS)

Ojeda-G-P, Alejandro; Schneider, Christof W.; Döbeli, Max; Lippert, Thomas; Wokaun, Alexander

2015-01-01

Highlights: • The flip-over effect in PLD is observed up to high deposition pressures. • Consistent congruent transfer of the target composition is generally not correct. • The choice of deposition pressure can change the film composition strongly. • Large compositional changes appear at high off-axis angles and large spot sizes. - Abstract: In pulsed laser deposition the use of a rectangular or elliptical beam spot with a non 1:1 aspect ratio leads to the so called flip-over effect. Here, the longest dimension of the laser spot results in the shortest direction of plasma plume expansion. This effect has been mainly reported for vacuum depositions of single element targets and is particularly noticeable when the aspect ratio of the beam spot is large. We investigate the flip-over effect in vacuum and at three relevant background-gas pressures for pulsed laser deposition using a La 0.4 Ca 0.6 MnO 3 target by measuring the thickness dependence of the deposited material as a function of angle. The film thicknesses and compositions are determined by Rutherford backscattering and argon is used to reduce the influence of additional chemical reactions in the plasma. The results show the prevalence of the flip-over effect for all pressures except for the highest, i.e. 1 × 10 −1 mbar, where the film thickness is constant for all angles. The composition profiles show noticeable compositional variations of up to 30% with respect to the target material depending on the background gas pressure, the angular location, and the laser spot dimensions.

Attempt to measure the cosmic background radiation at high altitude

International Nuclear Information System (INIS)

Labeyrie, Jacques; Le Boiteux, Henri

1959-01-01

Results are given of the measurement by G.M. tubes of hard component of cosmic background between o and 60 km of altitude, at 43 deg. N latitude, on january 27, 1959 (17 h. GMT). The counting rate starts at 0.3 pulses per second (sea level) reaches a maximum value of 15.6 (18 km) and remains constant at 5.7 above 40 km. Reprint of a paper published in Le Journal de Physique et le Radium, t. 20, p. 573, may 1959

Technique eliminates high voltage arcing at electrode-insulator contact area

Science.gov (United States)

Mealy, G.

1967-01-01

Coating the electrode-insulator contact area with silver epoxy conductive paint and forcing the electrode and insulator tightly together into a permanent connection, eliminates electrical arcing in high-voltage electrodes supplying electrical power to vacuum facilities.

A low-background piston-cylinder-type hybrid high pressure cell for muon-spin rotation/relaxation experiments

Science.gov (United States)

Shermadini, Z.; Khasanov, R.; Elender, M.; Simutis, G.; Guguchia, Z.; Kamenev, K. V.; Amato, A.

2017-10-01

A low background double-wall piston-cylinder-type pressure cell is developed at the Paul Scherrer Institute. The cell is made from BERYLCO-25 (beryllium copper) and MP35N nonmagnetic alloys with the design and dimensions which are specifically adapted to muon-spin rotation/relaxation (μSR) measurements. The mechanical design and performance of the pressure cell are evaluated using finite-element analysis (FEA). By including the measured stress-strain characteristics of the materials into the finite-element model, the cell dimensions are optimized with the aim to reach the highest possible pressure while maintaining the sample space large (6 mm in diameter and 12 mm high). The presented unconventional design of the double-wall piston-cylinder pressure cell with a harder outer MP35N sleeve and a softer inner CuBe cylinder enables pressures of up to 2.6 GPa to be reached at ambient temperature, corresponding to 2.2 GPa at low temperatures without any irreversible damage to the pressure cell. The nature of the muon stopping distribution, mainly in the sample and in the CuBe cylinder, results in a low-background μSR signal.

An efficient background modeling approach based on vehicle detection

Science.gov (United States)

Wang, Jia-yan; Song, Li-mei; Xi, Jiang-tao; Guo, Qing-hua

2015-10-01

The existing Gaussian Mixture Model(GMM) which is widely used in vehicle detection suffers inefficiency in detecting foreground image during the model phase, because it needs quite a long time to blend the shadows in the background. In order to overcome this problem, an improved method is proposed in this paper. First of all, each frame is divided into several areas(A, B, C and D), Where area A, B, C and D are decided by the frequency and the scale of the vehicle access. For each area, different new learning rate including weight, mean and variance is applied to accelerate the elimination of shadows. At the same time, the measure of adaptive change for Gaussian distribution is taken to decrease the total number of distributions and save memory space effectively. With this method, different threshold value and different number of Gaussian distribution are adopted for different areas. The results show that the speed of learning and the accuracy of the model using our proposed algorithm surpass the traditional GMM. Probably to the 50th frame, interference with the vehicle has been eliminated basically, and the model number only 35% to 43% of the standard, the processing speed for every frame approximately has a 20% increase than the standard. The proposed algorithm has good performance in terms of elimination of shadow and processing speed for vehicle detection, it can promote the development of intelligent transportation, which is very meaningful to the other Background modeling methods.

Study of Background Rejection Systems for the IXO Mission.

Science.gov (United States)

Laurent, Philippe; Limousin, O.; Tatischeff, V.

2009-01-01

The scientific performances of the IXO mission will necessitate a very low detector background level. This will imply thorough background simulations, and efficient background rejection systems. It necessitates also a very good knowledge of the detectors to be shielded. In APC, Paris, and CEA, Saclay, we got experience on these activities by conceiving and optimising in parallel the high energy detector and the active and passive background rejection system of the Simbol-X mission. Considering that this work may be naturally extended to other X-ray missions, we have initiated with CNES a R&D project on the study of background rejection systems mainly in view the IXO project. We will detail this activity in the poster.

Neutron- and muon-induced background in underground physics experiments

International Nuclear Information System (INIS)

Kudryavtsev, V.A.; Tomasello, V.; Pandola, L.

2008-01-01

Background induced by neutrons in deep underground laboratories is a critical issue for all experiments looking for rare events, such as dark matter interactions or neutrinoless ββ decay. Neutrons can be produced either by natural radioactivity, via spontaneous fission or (α, n) reactions, or by interactions initiated by high-energy cosmic rays. In all underground experiments, Monte Carlo simulations of neutron background play a crucial role for the evaluation of the total background rate and for the optimization of rejection strategies. The Monte Carlo methods that are commonly employed to evaluate neutron-induced background and to optimize the experimental setup, are reviewed and discussed. Focus is given to the issue of reliability of Monte Carlo background estimates. (orig.)

Neutron- and muon-induced background in underground physics experiments

Energy Technology Data Exchange (ETDEWEB)

Kudryavtsev, V.A.; Tomasello, V. [University of Sheffield, Department of Physics and Astronomy, Sheffield (United Kingdom); Pandola, L. [Laboratori Nazionali del Gran Sasso, INFN, Assergi (Italy)

2008-05-15

Background induced by neutrons in deep underground laboratories is a critical issue for all experiments looking for rare events, such as dark matter interactions or neutrinoless {beta}{beta} decay. Neutrons can be produced either by natural radioactivity, via spontaneous fission or ({alpha}, n) reactions, or by interactions initiated by high-energy cosmic rays. In all underground experiments, Monte Carlo simulations of neutron background play a crucial role for the evaluation of the total background rate and for the optimization of rejection strategies. The Monte Carlo methods that are commonly employed to evaluate neutron-induced background and to optimize the experimental setup, are reviewed and discussed. Focus is given to the issue of reliability of Monte Carlo background estimates. (orig.)

Identification and delineation of areas flood hazard using high accuracy of DEM data

Science.gov (United States)

Riadi, B.; Barus, B.; Widiatmaka; Yanuar, M. J. P.; Pramudya, B.

2018-05-01

Flood incidents that often occur in Karawang regency need to be mitigated. These expectations exist on technologies that can predict, anticipate and reduce disaster risks. Flood modeling techniques using Digital Elevation Model (DEM) data can be applied in mitigation activities. High accuracy DEM data used in modeling, will result in better flooding flood models. The result of high accuracy DEM data processing will yield information about surface morphology which can be used to identify indication of flood hazard area. The purpose of this study was to identify and describe flood hazard areas by identifying wetland areas using DEM data and Landsat-8 images. TerraSAR-X high-resolution data is used to detect wetlands from landscapes, while land cover is identified by Landsat image data. The Topography Wetness Index (TWI) method is used to detect and identify wetland areas with basic DEM data, while for land cover analysis using Tasseled Cap Transformation (TCT) method. The result of TWI modeling yields information about potential land of flood. Overlay TWI map with land cover map that produces information that in Karawang regency the most vulnerable areas occur flooding in rice fields. The spatial accuracy of the flood hazard area in this study was 87%.

Infrared image background modeling based on improved Susan filtering

Science.gov (United States)

Yuehua, Xia

2018-02-01

When SUSAN filter is used to model the infrared image, the Gaussian filter lacks the ability of direction filtering. After filtering, the edge information of the image cannot be preserved well, so that there are a lot of edge singular points in the difference graph, increase the difficulties of target detection. To solve the above problems, the anisotropy algorithm is introduced in this paper, and the anisotropic Gauss filter is used instead of the Gauss filter in the SUSAN filter operator. Firstly, using anisotropic gradient operator to calculate a point of image's horizontal and vertical gradient, to determine the long axis direction of the filter; Secondly, use the local area of the point and the neighborhood smoothness to calculate the filter length and short axis variance; And then calculate the first-order norm of the difference between the local area of the point's gray-scale and mean, to determine the threshold of the SUSAN filter; Finally, the built SUSAN filter is used to convolution the image to obtain the background image, at the same time, the difference between the background image and the original image is obtained. The experimental results show that the background modeling effect of infrared image is evaluated by Mean Squared Error (MSE), Structural Similarity (SSIM) and local Signal-to-noise Ratio Gain (GSNR). Compared with the traditional filtering algorithm, the improved SUSAN filter has achieved better background modeling effect, which can effectively preserve the edge information in the image, and the dim small target is effectively enhanced in the difference graph, which greatly reduces the false alarm rate of the image.

Modulation of the Object/Background Interaction by Spatial Frequency

Directory of Open Access Journals (Sweden)

Yanju Ren

2011-05-01

Full Text Available With regard to the relationship between object and background perception in the natural scene images, functional isolation hypothesis and interactive hypothesis were proposed. Based on previous studies, the present study investigated the role of spatial frequency in the relationship between object and background perception in the natural scene images. In three experiments, participants reported the object, background, or both after seeing each picture for 500 ms followed by a mask. The authors found that (a backgrounds were identified more accurately when they contained a consistent rather than an inconsistent object, independently of spatial frequency; (b objects were identified more accurately in a consistent than an inconsistent background under the condition of low spatial frequencies but not high spatial frequencies; (c spatial frequency modulation remained when both objects and backgrounds were reported simultaneously. The authors conclude that object/background interaction is partially dependent on spatial frequency.

The Influence Of Parental Background On Academic Performance Of ...

African Journals Online (AJOL)

It was hypothesized that there is no significant difference between the academic performance of students from high socio-economic status background and those from low SES backgrounds, also there is no significant difference between the academic performance of students form intact homes and the broken homes.

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

International Nuclear Information System (INIS)

Shanthi, G.; Thampi Thanka kumaran, J.; Allen Gnana raj, G.; Maniyan, C. G.

2012-01-01

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 x 10. -2 , 14.2 x 10. -2 , 5.8 x 10. -2 and 6.3 x 10. -2 , respectively. The TF of tapioca for 226 Ra, 232 Th, 238 U and 40 K are 6.2 x 10 -2 , 11 x 10 -2 , 1.9 x 10 -2 and 8.9 x 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. (authors)

A novel background reduction strategy for high level triggers and processing in gamma-ray Cherenkov detectors

International Nuclear Information System (INIS)

Cabras, G.; De Angelis, A.; De Lotto, B.; De Maria, M. M.; De Sabata, F.; Mansutti, O.; Frailis, M.; Persic, M.; Bigongiari, C.; Doro, M.; Mariotti, M.; Peruzzo, L.; Saggion, A.; Scalzotto, V.; Paoletti, R.; Scribano, A.; Turini, N.; Moralejo, A.; Tescaro, D.

2008-01-01

Gamma ray astronomy is now at the leading edge for studies related both to fundamental physics and astrophysics. The sensitivity of gamma detectors is limited by the huge amount of background, constituted by hadronic cosmic rays (typically two to three orders of magnitude more than the signal) and by the accidental background in the detectors. By using the information on the temporal evolution of the Cherenkov light, the background can be reduced. We will present here the results obtained within the MAGIC experiment using a new technique for the reduction of the background. Particle showers produced by gamma rays show a different temporal distribution with respect to showers produced by hadrons; the background due to accidental counts shows no dependence on time. Such novel strategy can increase the sensitivity of present instruments

Dim point target detection against bright background

Science.gov (United States)

Zhang, Yao; Zhang, Qiheng; Xu, Zhiyong; Xu, Junping

2010-05-01

For target detection within a large-field cluttered background from a long distance, several difficulties, involving low contrast between target and background, little occupancy, illumination ununiformity caused by vignetting of lens, and system noise, make it a challenging problem. The existing approaches to dim target detection can be roughly divided into two categories: detection before tracking (DBT) and tracking before detection (TBD). The DBT-based scheme has been widely used in practical applications due to its simplicity, but it often requires working in the situation with a higher signal-to-noise ratio (SNR). In contrast, the TBD-based methods can provide impressive detection results even in the cases of very low SNR; unfortunately, the large memory requirement and high computational load prevents these methods from real-time tasks. In this paper, we propose a new method for dim target detection. We address this problem by combining the advantages of the DBT-based scheme in computational efficiency and of the TBD-based in detection capability. Our method first predicts the local background, and then employs the energy accumulation and median filter to remove background clutter. The dim target is finally located by double window filtering together with an improved high order correlation which speeds up the convergence. The proposed method is implemented on a hardware platform and performs suitably in outside experiments.

Background rejection in NEXT using deep neural networks

CERN Document Server

Renner, J.

2017-01-01

We investigate the potential of using deep learning techniques to reject background events in searches for neutrinoless double beta decay with high pressure xenon time projection chambers capable of detailed track reconstruction. The differences in the topological signatures of background and signal events can be learned by deep neural networks via training over many thousands of events. These networks can then be used to classify further events as signal or background, providing an additional background rejection factor at an acceptable loss of efficiency. The networks trained in this study performed better than previous methods developed based on the use of the same topological signatures by a factor of 1.2 to 1.6, and there is potential for further improvement.

Background rejection in NEXT using deep neural networks

International Nuclear Information System (INIS)

Renner, J.; Farbin, A.; Vidal, J. Muñoz; Benlloch-Rodríguez, J. M.; Botas, A.

2017-01-01

Here, we investigate the potential of using deep learning techniques to reject background events in searches for neutrinoless double beta decay with high pressure xenon time projection chambers capable of detailed track reconstruction. The differences in the topological signatures of background and signal events can be learned by deep neural networks via training over many thousands of events. These networks can then be used to classify further events as signal or background, providing an additional background rejection factor at an acceptable loss of efficiency. The networks trained in this study performed better than previous methods developed based on the use of the same topological signatures by a factor of 1.2 to 1.6, and there is potential for further improvement.

[PM₂.₅ Background Concentration at Different Directions in Beijing in 2013].

Science.gov (United States)

Li, Yun-ting; Cheng, Niam-liang; Zhang, Da-wei; Sun, Rui-wen; Dong, Xin; Sun, Nai-di; Chen, Chen

2015-12-01

PM₂.₅, background concentration at different directions in 2013 in Beijing was analyzed combining the techniques of mathematical statistics, physical identification and numerical simulation (CMAQ4.7.1) as well as using monitoring data of six PM₂.₅ auto-monitoring sites and five meteorological sites in 2013. Results showed that background concentrations of PM₂.₅ at northwest, northeast, eastern, southeast, southern and southwest boundary sites were between 40.3 and 85.3 µg · m⁻³ in Beijing. From the lowest to the highest, PMPM₂.₅ background concentrations at different sites were: Miyun reservoir, Badaling, Donggaocun, Yufa, Yongledian and Liulihe. Background concentration of PM₂.₅ was the lowest under north wind, then under west wind, and significantly higher under south and east wind. Calculated PM₂.₅ background average concentrations were 6.5-27.9, 22.4-73.4, 67.2-91.7, 40.7-116.1 µg · m⁻³ respectively in different wind directions. Simulated PM₂.₅ background concentration showed a clear north-south gradient distribution and the surrounding area had a notable effect on the spatial distribution of PM₂.₅ background concentration in 2013 in Beijing.

The Identification of Technology Platforms and Innovation Areas with High Regional Impact

Directory of Open Access Journals (Sweden)

Nataša Urbančíková

2011-10-01

Full Text Available The paper is focused on the process of identification of the technological platforms and innovation areas with high regional impact. The aim is to discover future fields of technological innovation which are having a high qualitative and quantitative demand of high potentials. The research has been undertaken within project Innovative Development of European Areas by fostering transnational Knowledge Development – IDEA/ 2CE1175P1 funded by Central Europe Programme. The aim of IDEA project is the development of an adequate strategy which enables the small and medium sized enterprises in the regions of Central Europe to face the increasing demand of high potentials with tested methods and instruments. The target group of IDEA project are so called “high potentials” in the engineering and scientific sector where future-oriented technologies are one of the main sources of innovation.

Correlation of maternal age, gravida status, major malformations, stillbirth and sex ratio in high level natural radiation areas of Kerala coast

International Nuclear Information System (INIS)

Sudheer, K.R.; Koya, P.K.M.; Jaikrishan, G.; Das, Birajalaxmi

2016-01-01

As a part of the ongoing study on biological and health effects of chronic low dose and/or dose rate on human population, consecutive births were monitored in selected Govt. hospitals located in normal and high level natural radiation areas (HLNRA) of Kerala coast. This area is unique because of its vast population size and varied range of background radiation level due to natural deposit of monazite containing thorium. The objective is to elucidate the role of chronic low dose radiation, if any, on the adverse pregnancy outcome. Since 1995, ∼1,70,000 newborns were monitored in this area, of which 74,238 singleton first births were monitored. Of these, 634 (0.85%) cases were observed with detectable major congenital malformations (that include serious structural, functional or cosmetic disability requiring surgical or medical management) and 240 (0.32%) cases were stillborn. Sex ratio at first birth was observed in the ratio of 1050 males to 1000 females. The distribution of age at marriage of the mothers was stratified into the following groups: d"18 years (15.5%), 19 20 years (25.9%), 21 22 years (25.6%), 23 24 years (17.2%) and >25 years (15.8%). It was observed that about 78.9% mothers had their first birth within one year of marriage, 13.7% had their first birth within 1.1 2 years and 5.2% within 2.1 4 years. About 2.2% (1613) mothers had their first child after 4 years or more. Individual, combined and interactive effects of age at marriage, first birth interval (first gravida status), background radiation levels and gender of the newborn on major congenital malformation and stillbirth will be discussed. (author)

The fMRI analysis of brain activation in response to face image affected by background images

International Nuclear Information System (INIS)

Shimada, Takamasa; Fukami, Tadanori; Saito, Yoichi

2011-01-01

The stimuli of a face images expressing fear induce the activation in the medial temporal lobe was reported in previous studies. In particular, it was reported that face image expressing fear activated the amygdala and hippo-campus area of brain. In these studies, no background images were used with facial stimuli. However, normal day-to-day images always have a background. We investigated the effect of combining face images expressing fear and different background images. As a result, strong activation was detected in the amygdala and hippocampus area when the lightning background image was used. But strong activation was not detected when the fire background image was used. From the results of questionnaire rating the impression of possibility of experiencing the situation of shown images, it is thought that this difference of impression of possibility made the difference of empathy and caused the difference of brain activation. (author)

High inter-specimen variability of baseline data for the tibio-talar contact area.

Science.gov (United States)

Matricali, Giovanni A; Bartels, Ward; Labey, Luc; Dereymaeker, Greta Ph E; Luyten, Frank P; Vander Sloten, Jos

2009-01-01

The tibio-talar contact area has been widely investigated to monitor biomechanical changes due to articular incongruities or an altered loading. This study aims to investigate for the first time in a systematic way the extent of the inter-specimen variability of the tibio-talar contact area, and its repercussions when analyzing data concerning this parameter. Ten specimens were loaded to record the tibio-talar contact characteristics by use of pressure sensitive film. The size of the talar dome area, the size of the (normalized) tibio-talar contact area, the position of the tibio-talar contact area, and the shape of the latter were determined and analyzed. Inter-specimen variability was expressed as the coefficient of variation and was calculated for the datasets of previous studies as well. The size of the tibio-talar contact area showed a very high inter-specimen variability, as is the case in previous studies. This high variability persisted when a normalized tibio-talar contact area was calculated. The shape of the tibio-talar contact area showed some basic characteristics, but a high variation in details could be observed. Every specimen can be considered to have its own "ankle print". By this variability, articular incongruities are expected to have a different effect on local biomechanical characteristics in every single individual. Therefore, every single case has to be evaluated and reported for significant changes. In case of modeling, this also underscores the need to use subject specific models fed by sets of parameters derived from a series of single specimens.

ASSOCIATIONS BETWEEN SMALL-SCALE STRUCTURE IN LOCAL GALACTIC NEUTRAL HYDROGEN AND IN THE COSMIC MICROWAVE BACKGROUND OBSERVED BY PLANCK

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